Odontologia

Parodontite (Pyorrhée)

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Par James T. Ubertalli, DMD, Private Practice, Hingham, MA

 

La parodontite est une forme sévère de gingivite dans laquelle l’inflammation des gencives se propage à toutes les structures d’appui de la dent.

  • La plaque et le tartre se développent entre les dents et les gencives puis diffusent sur l’os sous les dents.

  • Les gencives se tuméfient et saignent, la personne a mauvaise haleine et les dents se déchaussent.

  • Le médecin prend des radiographies et mesure la profondeur des poches parodontales dans la gencive pour déterminer la gravité de la parodontite.

  • Des nettoyages répétés chez un spécialiste et parfois une chirurgie dentaire et un traitement par des antibiotiques sont nécessaires.

La parodontite touche les personnes qui sont susceptibles de présenter une infection plus sévère du tissu parodontal (le tissu qui entoure les dents) que celle qui survient dans la gingivite. De nombreuses maladies et de nombreuses affections, en particulier le diabète (plus spécialement le type 1), le syndrome de Down, la maladie de Crohn, la leucopénie et le SIDA, prédisposent à la parodontite. Chez les personnes infectées par le virus du SIDA, la parodontite progresse rapidement. Le tabagisme, la carence en vitamine C (scorbut), la détresse émotionnelle et, potentiellement, l’obésité, sont également des facteurs de risque de parodontite.

La parodontite peut toucher des personnes de tout âge, y compris les jeunes enfants. Certaines personnes ont une gingivite sévère pendant de nombreuses années sans développer de parodontite. D’autres peuvent développer une parodontite, particulièrement lorsqu’elles sont jeunes (entre 20 et 30 ans), sans avoir jamais présenté de gingivite.

La parodontite est l’une des principales causes des pertes dentaires chez l’adulte et la principale cause chez les personnes âgées. Les infections vont éroder (user) l’os qui maintient les dents en place. L’érosion affaiblit les ligaments et les dents se déchaussent. Une dent lésée peut finir par tomber spontanément ou nécessiter une extraction.

Causes de la parodontite

La majeure partie des parodontites découle d’une inflammation des gencives (gingivite) et d’une accumulation à long terme de plaque dentaire (une pellicule principalement composée de bactéries) et de tartre (plaque dentaire durcie) sur les dents et les gencives. Des poches se forment entre les dents et les gencives et descendent entre les racines des dents et l’os sous-jacent. Ces poches accumulent la plaque dans un environnement dépourvu d’oxygène, ce qui favorise la croissance de formes agressives de bactéries chez les personnes dont le système immunitaire présente certaines sensibilités. La plaque et les bactéries provoquent une inflammation chronique qui endommage le tissu et l’os qui maintiennent les dents en place. Si le processus pathologique se poursuit, une grande quantité d’os est détruite entraînant une mobilité douloureuse de la dent, et les gencives se rétractent. La perte de dents débute typiquement vers les 40 ans.

Le saviez-vous ?

  • La parodontite est la principale cause des pertes dentaires chez les personnes âgées.

Parodontite : De la plaque à la perte dentaire

Des gencives et une structure osseuse saines maintiennent les dents solidement en place.

Parodontite : De la plaque à la perte dentaire

Parodontite : De la plaque à la perte dentaire

La plaque qui s’accumule irrite les gencives qui deviennent enflammées (gingivite). Avec le temps, la gencive s’écarte de la dent, créant une poche qui se remplit de plus de plaque.

Parodontite : De la plaque à la perte dentaire

Parodontite : De la plaque à la perte dentaire

Les poches deviennent plus profondes et la plaque durcit pour se transformer en tartre. Plus de plaque s’accumule sur le dessus.

Parodontite : De la plaque à la perte dentaire

Parodontite : De la plaque à la perte dentaire

L’infection bactérienne se propage à la racine de la dent et détruit ensuite l’os qui soutient la dent. Sans ce soutien, la dent se déchausse et finit par tomber.

Parodontite : De la plaque à la perte dentaire

Parodontite : De la plaque à la perte dentaire

La vitesse à laquelle se développe la parodontite varie considérablement, même chez les personnes qui ont des quantités similaires de tartre. Ces différences existent parce que la plaque dentaire de chaque personne contient des bactéries de type et en nombre différents, et parce que la parodontite est due à la réponse immunitaire différente de la personne face aux bactéries dans la plaque. La parodontite peut entraîner des poussées d’activité de destruction pouvant durer des mois, suivies de périodes où la maladie ne semble apparemment pas provoquer d’autres dommages.

Symptômes de la parodontite

Les symptômes initiaux de la parodontite sont une sensibilité, une tuméfaction, une hémorragie et une couleur rouge vif des gencives ainsi qu’une mauvaise haleine (halitose). À mesure que davantage de matière osseuse est résorbée, les dents deviennent mobiles et changent de position, et la mastication devient plus difficile. Les dents antérieures s’inclinent fréquemment vers l’extérieur. La parodontite ne provoque généralement pas de douleur tant qu’il ne se forme pas d’infection, telle qu’une accumulation de pus (abcès) dans une poche, que les dents sont suffisamment stables pour ne pas bouger au cours de la mastication ou tant que la personne n’a pas de parodontite due au VIH.

Parodontite

Parodontite

Parodontite

CNRI/SCIENCE PHOTO LIBRARY

Diagnostic de parodontite

  • Examen dentaire par un dentiste

  • Parfois, radiographies

Pour diagnostiquer une parodontite, le dentiste inspecte les dents et mesure la profondeur des poches gingivales à l’aide d’une sonde fine. Des radiographies sont réalisées pour déterminer l’étendue de la perte osseuse.

Traitement de la parodontite

  • Traitement des facteurs de risque

  • Nettoyages professionnels

  • Parfois, chirurgie et extraction d’une dent

  • Parfois, antibiotiques

Les personnes présentant des facteurs de risque, tels que mauvaise hygiène bucco-dentaire, diabète et tabagisme, doivent recevoir des traitements pour ces facteurs de risque. Le traitement des facteurs de risque augmente le succès des traitements de la parodontite administrés par le dentiste.

À la différence de la gingivite, qui disparaît en général avec une bonne hygiène bucco-dentaire (brossage des dents et fil dentaire tous les jours), la parodontite nécessite des soins répétés prodigués par un spécialiste. Les personnes qui ont une bonne hygiène bucco-dentaire ne peuvent nettoyer que jusqu’à 2 ou 3 millimètres au-dessous du bord gingival. Le dentiste, quant à lui, peut nettoyer des poches gingivales de 6 à 7 millimètres de profondeur avec des techniques de détartrage et de polissage radiculaire, en éliminant complètement la plaque dentaire et le tartre tout en améliorant l’état des surfaces radiculaires.

En cas de poches gingivales de profondeur supérieure à 7 millimètres, un traitement chirurgical est souvent nécessaire. Le dentiste ou le parodontologue peut accéder chirurgicalement à la dent sous le bord gingival en soulevant chirurgicalement un lambeau de tissu gingival (chirurgie parodontale). Il nettoie les dents soigneusement et corrige les résorptions osseuses (parfois par une greffe osseuse) sous le lambeau puis il recoud celui-ci. Le dentiste ou le parodontologue peut aussi enlever la portion de gencive mobile et infectée (gingivectomie), ce qui permet au reste de la gencive d’adhérer de nouveau étroitement aux dents, redonnant ainsi à la personne la possibilité d’éliminer la plaque dentaire chez elle. Parfois les dents sont extraites. En cas de douleur après un traitement chirurgical, des bains de bouche à base de chlorhexidine pratiqués pendant une minute deux fois par jour peuvent temporairement se substituer à l’emploi de la brosse à dents et du fil dentaire.

Le dentiste peut prescrire des antibiotiques (comme l’amoxicilline ou le métronidazole), en particulier si une accumulation de pus (abcès) s’est développée. Il peut également insérer un matériau (filaments ou gels) contenant des antibiotiques dans les poches parodontales profondes, permettant à de fortes concentrations d’antibiotiques d’atteindre la zone infectée. Les abcès parodontaux entraînent une poussée de destruction osseuse, mais un traitement chirurgical immédiat associé à une antibiothérapie peut permettre à l’os lésé de se reformer rapidement.

Anúncios

#Identifican #biomarcadores de la saliva eficaces para detectar #cáncer oral

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Investigadores españoles han identificado que los biomarcadores de mARN en saliva son los más eficaces para detectar precozmente cáncer oral, publica ‘Journal of Oral Pathology and Medicine’.

Los biomarcadores en saliva pueden detectar cáncer oral.

Más del 90 por ciento de los tumores malignos en cabeza y cuello tienen su origen en carcinomas de células escamosas que se originan en zonas superficiales de la cavidad oral. Su detección a través de biomarcadores en la saliva puede contribuir a su tratamiento precoz, antes de su transformación en tumores. Investigadores del Grupo de Investigación de Microbiología Oral de la Universidad CEU Cardenal Herrera han realizado una revisión sistemática y un meta-analisis de aquellos marcadores en saliva que presentan mayor eficacia para la detección temprana de cáncer oral en distintos ensayos clínicos. Sus resultados acaban de ser publicados en el Journal of Oral Pathology and Medicine.

Según Verónica Veses, investigadora principal del Grupo y profesora del Departamento de Ciencias Biomédicas de la CEU UCH, “la detección de este tipo de cáncer de células escamosas en las superficies de la boca depende fundamentalmente del examen visual de los profesionales de la salud buco-dental. Por eso es importante encontrar nuevos métodos diagnósticos para ayudar a su detección temprana de forma más certera. Sobre todo, si tenemos en cuenta que el cáncer oral es el origen más frecuente de otros tumores en cabeza y cuello, y que es creciente entre la población joven, debido al consumo de tabaco y alcohol”.

Tres tipos de biomarcadores

El equipo ha realizado una revisión sistemática y un meta-análisis de los ensayos clínicos que hasta ahora han evaluado la eficacia de los tres tipos de biomarcadores de la saliva más prometedores para la detección de este tipo de cáncer oral. Estos marcadores de la saliva son dos tipos de citocinas, proteínas involucradas en la proliferación y diferenciación celular; dos marcadores presentes en el ácido ribonucleico que transfiere el código genético, el ARN mensajero o mARN; y dos más en el microARN (miARN) de la saliva.

Los biomarcadores en saliva del mARN han resultado ser los más eficaces para la detección precoz del carcinoma oral de células escamosas

Los dos biomarcadores del mRNA han resultado los más eficaces para la detección precoz del carcinoma oral de células escamosas y del cáncer de cuello y cabeza, al comparar los resultados obtenidos en los 17 ensayos clínicos revisados en la investigación. Estos ensayos fueron seleccionados como pertinentes para el estudio entre los publicados desde el año 2000 en la base de datos internacional Medline y en el registro internacional de ensayos clínicos: el Central Register of Controlled Trials.

Los resultados actuales forman parte del trabajo fin de rrado de la estudiante de Dentistry en la Universidad CEU Cardenal Herrera Fariah Gaba, bajo la dirección de los profesores Verónica Veses y Chirag Sheth, miembros del Grupo de Microbiologia Oral. Fariah Gaba, que ha obtenido el Premio Extraordinario de Licenciatura por sus estudios de Dentistry en la CEU UCH, ejerce actualmente como odontóloga en Holanda y comenzó su labor investigadora trabajando en uno de los proyectos I+Docencia del citado grupo.

#DIFERENT CLASSES OF ANTIBIOTICS

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Resultado de imagem para antibiotics

 

Bacteria themselves can be divided into two broad classes – Gram-positive and Gram-negative. The classes derive these names from the Gram test, which involves the addition of a violet dye to the bacteria. Gram-positive bacteria retain the colour of the dye, whilst Gram-negative bacteria do not, and are instead coloured red or pink. Gram-negative bacteria are more resistant to antibodies and antibiotics than Gram-positive bacteria, because they have a largely impermeable cell wall. The bacteria responsible for MRSA and acne are examples of Gram-positive bacteria, whilst those responsible for Lyme disease and pneumonia are examples of Gram-negative bacteria. Beta-Lactams Beta-lactams are a wide range of antibiotics, the first of which to be discovered was penicillin, which Alexander Fleming identified in 1928. All beta-lactam antibiotics contain a beta-lactam ring; they include penicillins, such as amoxicillin, and cephalosporins. Bacteria can develop resistance to beta-lactams via several routes, including the production of enzymes that break down the beta-lactam ring. In the NHS, penicillins are the most commonly prescribed antibiotics, with amoxicillin being the most common in the class. Sulfonamides Prontosil, a sulfonamide, was the first commercially available antibiotic, developed in 1932. In the present day, sulfonamides are rarely used, partially due to the development of bacterial resistance, but also due to concern about unwanted effects such as damage to the liver of patients. Aminoglycosides Aminoglycosides inhibit the synthesis of proteins in bacteria, eventually leading to cell death. In the treatment of tuberculosis, streptomycin was the first drug found to be effective; however, due to issues with toxicity of aminoglycosides, their present day use is limited. Tetracyclines Tetracyclines are broad-spectrum antibiotics, active against both Gram-positive and Gram-negative bacteria. Their use is decreasing to increasing instances of bacterial resistance; however, they still find use in treatment of acne, urinary tract, and respiratory tract infections, as well as chlamydia infections. Chloramphenicol Another broad-spectrum antibiotic, chloramphenicol also acts by inhibiting protein synthesis, and thus growth and reproduction of bacteria. Due to the possibility of serious toxic effects, in developed countries it is generally only used in cases where infections are deemed to be life-threatening, although it is a much more common antibiotic in developing countries due to its low cost and availability. Macrolides Macrolides’ effectiveness is marginally broader than that of penicillins, and they have been shown to be effective against several species of bacteria that penicillins are not. Whilst some bacterial species have developed resistance to macrolides, they are still the second most commonly prescribed antibiotics in the NHS, with erythromycin being the most commonly prescribed in the class. Glycopeptides Glycopeptides include the drug vancomycin – commonly used as a ‘drug of last resort’, when other antibiotics have failed. There are strict guidelines on the circumstances in which vancomycin can be used to treat infections, in order to delay the development of resistance. The bacteria against which glycopeptides are active are otherwise somewhat limited, and in most they inhibit growth and reproduction rather than killing bacteria directly. Oxazolidinones Oxazolidinones are active against Gram-positive bacteria, and act by inhibiting protein synthesis, and hence growth and reproduction. Linezolid, approved for use in 2000, was the first marketed antibiotic in the class, and resistance seems to be developing relatively slowly since its introduction. Ansamycins This class of antibiotics are effective against Gram-positive bacteria, as well as some Gram-negative bacteria. A subclass of antibiotics, rifamycins, are used to treat tuberculosis and leprosy. Uncommonly, ansamycins can also demonstrate anti-viral activity. Quinolones Quinolones are widely used for urinary tract infections, as well as other hospital-acquired infections where resistance to older classes of antibiotics is suspected. Resistance to quinolones can be particularly rapid in its development; in the US, they were the most commonly prescribed antibiotics in 2002, and their prescription for unrecommended conditions or viral infections is also thought to be a significant contributor to the development of resistance. Streptogramins Streptogramins are unusual in that they are usually administered as a combination of two antibiotic drugs from the different groups within the class; combined they have a synergistic effect and are capable of directly killing bacteria cells. They are often used to treat resistant infections, although resistance to the streptogramins themselves has also developed. Lipopeptides Discovered in 1987, lipopeptides are the most recent class of antibiotics. Daptomycin is the most commonly used member of the class; it has a unique mechanism of action, disrupting several aspects of cell membrane function in bacteria. This unique mechanism of action also seems to be advantageous in that, currently, incidences of resistance to the drug seem to be rare – though they have been reported. Below are some summaries and mind maps that will make learning antibiotics and their uses easier.

Read more at: https://forum.facmedicine.com/threads/antibiotics-types-and-mechanism-of-action.35444/

#Traditional Chinese Medicine: In Depth

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jars of Chinese herbs

Introduction

Traditional Chinese medicine (TCM) originated in ancient China and has evolved over thousands of years. TCM practitioners use herbal medicines and various mind and body practices, such as acupuncture and tai chi, to treat or prevent health problems. In the United States, people use TCM primarily as a complementary health approach. This fact sheet provides a general overview of TCM and suggests sources for additional information.

Key Points

Is It Safe?

  • Acupuncture is generally considered safe when performed by an experienced practitioner using sterile needles. Improperly performed acupuncture can cause potentially serious side effects.
  • Tai chi and qi gong, two mind and body practices used in TCM, are generally safe.
  • There have been reports of Chinese herbal products being contaminated with drugs, toxins, or heavy metals or not containing the listed ingredients. Some of the herbs used in Chinese medicine can interact with drugs, have serious side effects, or be unsafe for people with certain medical conditions.

Is It Effective?

  • For most conditions, there is not enough rigorous scientific evidence to know whether TCM methods work for the conditions for which they are used.

Keep in Mind

  • Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

Background

TCM encompasses many different practices, including acupuncture, moxibustion (burning an herb above the skin to apply heat to acupuncture points), Chinese herbal medicine, tui na (Chinese therapeutic massage), dietary therapy, and tai chi and qi gong (practices that combine specific movements or postures, coordinated breathing, and mental focus). TCM is rooted in the ancient philosophy of Taoism and dates back more than 2,500 years. Traditional systems of medicine also exist in other East and South Asian countries, including Japan (where the traditional herbal medicine is called Kampo) and Korea. Some of these systems have been influenced by TCM and are similar to it in some ways, but each has developed distinctive features of its own.

Although the exact number of people who use TCM in the United States is unknown, it was estimated in 1997 that some 10,000 practitioners served more than 1 million patients each year. According to the 2007 National Health Interview Survey (NHIS), which included a comprehensive survey on the use of complementary health approaches by Americans, an estimated 3.1 million U.S. adults had used acupuncture in the previous year. The number of visits to acupuncturists tripled between 1997 and 2007. According to the 2007 NHIS, about 2.3 million Americans practiced tai chi and 600,000 practiced qi gong in the previous year.

This fact sheet focuses on TCM as a whole. For information about some of the individual practices included in TCM, see the pages on acupuncturetai chi, and qi gong on the National Center for Complementary and Integrative Health (NCCIH) Web site. Some of the individual herbs used in TCM are discussed in NCCIH’s Herbs at a Glance fact sheets.

Side Effects and Risks

  • Herbal medicines used in TCM are sometimes marketed in the United States as dietary supplements. The U.S. Food and Drug Administration (FDA) regulations for dietary supplements are not the same as those for prescription or over-the-counter drugs; in general, the regulations for dietary supplements are less stringent. For example, manufacturers don’t have to prove to the FDA that most claims made for dietary supplements are valid; if the product were a drug, they would have to provide proof.
  • Some Chinese herbal products may be safe, but others may not be. There have been reports of products being contaminated with drugs, toxins, or heavy metals or not containing the listed ingredients. Some of the herbs used in Chinese medicine can interact with drugs, can have serious side effects, or may be unsafe for people with certain medical conditions. For example, the Chinese herb ephedra (ma huang) has been linked to serious health complications, including heart attack and stroke. In 2004, the FDA banned the sale of ephedra-containing dietary supplements, but the ban does not apply to TCM remedies.
  • The FDA regulates acupuncture needles as medical devices and requires that the needles be sterile, nontoxic, and labeled for single use by qualified practitioners only. Relatively few complications from the use of acupuncture have been reported. However, adverse effects—some of them serious—have resulted from the use of nonsterile needles or improper delivery of acupuncture treatments.
  • Tai chi and qi gong are considered to be generally safe practices.
  • Information on the safety of other TCM methods is limited. Reported complications of moxibustion include allergic reactions, burns, and infections, but how often these events occur is not known. Both moxibustion and cupping (applying a heated cup to the skin to create a slight suction) may mark the skin, usually temporarily. The origin of these marks should be explained to health care providers so that they will not be mistaken for signs of disease or physical abuse.

Underlying Concepts

When thinking about ancient medical systems such as TCM, it is important to separate questions about traditional theories and concepts of health and wellness from questions about whether specific interventions might be helpful in the context of modern science-based medicine and health promotion practices.

The ancient beliefs on which TCM is based include the following:

  • The human body is a miniature version of the larger, surrounding universe.
  • Harmony between two opposing yet complementary forces, called yin and yang, supports health, and disease results from an imbalance between these forces.
  • Five elements—fire, earth, wood, metal, and water—symbolically represent all phenomena, including the stages of human life, and explain the functioning of the body and how it changes during disease.
  • Qi, a vital energy that flows through the body, performs multiple functions in maintaining health.

Concepts such as these are of interest in understanding the history of TCM. However, NCCIH-supported research on TCM does not focus on these ideas. Instead, it examines specific TCM practices from a scientific perspective, looking at their effects in the body and whether the practices are helpful in symptom management.

TCM practitioners use a variety of techniques in an effort to promote health and treat disease. In the United States, the most commonly used approaches include Chinese herbal medicine, acupuncture, and tai chi.

  • Chinese herbal medicine. The Chinese Materia Medica (a pharmacological reference book used by TCM practitioners) describes thousands of medicinal substances—primarily plants, but also some minerals and animal products. Different parts of plants, such as the leaves, roots, stems, flowers, and seeds, are used. In TCM, herbs are often combined in formulas and given as teas, capsules, liquid extracts, granules, or powders.
  • Acupuncture. Acupuncture is a family of procedures involving the stimulation of specific points on the body using a variety of techniques. The acupuncture technique that has been most often studied scientifically involves penetrating the skin with thin, solid, metal needles that are manipulated by the hands or by electrical stimulation.
  • Tai chi. Tai chi is a centuries-old mind and body practice. It involves gentle, dance-like body movements with mental focus, breathing, and relaxation.

The Status of TCM Research

In spite of the widespread use of TCM in China and its use in the West, rigorous scientific evidence of its effectiveness is limited. TCM can be difficult for researchers to study because its treatments are often complex and are based on ideas very different from those of modern Western medicine.

Most research studies on TCM have focused on specific techniques, primarily acupuncture and Chinese herbal remedies, and there have been many systematic reviews of studies of TCM approaches for various conditions.

  • An assessment of the research found that 41 of 70 systematic reviews of the scientific evidence (including 19 of 26 reviews on acupuncture for a variety of conditions and 22 of 42 reviews on Chinese herbal medicine) were unable to reach conclusions about whether the technique worked for the condition under investigation because there was not enough good-quality evidence. The other 29 systematic reviews (including 7 of 26 reviews on acupuncture and 20 of 42 reviews on Chinese herbal medicine) suggested possible benefits but could not reach definite conclusions because of the small quantity or poor quality of the studies.
  • In a 2012 analysis that combined data on individual participants in 29 studies of acupuncture for pain, patients who received acupuncture for back or neck pain, osteoarthritis, or chronic headache had better pain relief than those who did not receive acupuncture. However, in the same analysis, when actual acupuncture was compared with simulated acupuncture (a sham procedure that resembles acupuncture but in which the needles do not penetrate the skin or penetrate it only slightly), the difference in pain relief between the two treatments was much smaller—so small that it may not have been meaningful to patients.
  • Tai chi has not been investigated as extensively as acupuncture or Chinese herbal medicine, but recent studies, including some supported by NCCIH, suggest that practicing tai chi may help to improve balance and stability in people with Parkinson’s disease; reduce pain from knee osteoarthritis and fibromyalgia; and promote quality of life and mood in people with heart failure.

If You Are Thinking About Using TCM

  • Do not use TCM to replace effective conventional care or as a reason to postpone seeing a health care provider about a medical problem.
  • Look for published research studies on TCM for the health condition that interests you.
  • It is better to use TCM herbal remedies under the supervision of your health care provider or a professional trained in herbal medicine than to try to treat yourself.
  • Ask about the training and experience of the TCM practitioner you are considering. You can find information about the credentials and licensing of complementary health practitioners on the NCCIH Web site.
  • If you are pregnant or nursing, or are thinking of using TCM to treat a child, you should be especially sure to consult your (or the child’s) health care provider.
  • Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

Toll-free in the U.S.:
1-888-644-6226
TTY (for deaf and hard-of-hearing callers):
1-866-464-3615

PubMed®

A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.

Cochrane Database of Systematic Reviews

The Cochrane Database of Systematic Reviews is a collection of evidence-based reviews produced by the Cochrane Library, an international nonprofit organization. The reviews summarize the results of clinical trials on health care interventions. Summaries are free; full-text reviews are by subscription only.

NIH Clinical Research Trials and You

The National Institutes of Health (NIH) has created a Web site, NIH Clinical Research Trials and You, to help people learn about clinical trials, why they matter, and how to participate. The site includes questions and answers about clinical trials, guidance on how to find clinical trials through ClinicalTrials.gov and other resources, and stories about the personal experiences of clinical trial participants. Clinical trials are necessary to find better ways to prevent, diagnose, and treat diseases.

Research Portfolio Online Reporting Tools Expenditures & Results (RePORTER)

RePORTER is a database of information on federally funded scientific and medical research projects being conducted at research institutions.

Key References

Acknowledgments

NCCIH thanks the following people for their technical expertise and review of the update of this publication: Adam Burke, Ph.D., M.P.H., L.Ac., San Francisco State University; Ted Kaptchuk, O.M.D., Harvard Medical School; Lixing Lao, M.D., Ph.D., L.Ac., University of Maryland Medical Center; and Wendy Weber, N.D., Ph.D., M.P.H., and John (Jack) Killen, Jr., M.D., NCCIH.

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

 

* Note: PDF files require a viewer such as the free Adobe Reader(link is external).

NCCIH Pub No.:
D428

#A desidratação pode afetar negativamente o desempenho cognitivo?

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desidratação pode afetar negativamente o desempenho cognitivo? Para responder essa questão, pesquisadores realizaram uma revisão sistemática da literatura e meta-análise. Os resultados foram publicados em julho na revista Medicine & Science in Sports & Exercise.

No total, 33 estudos com 413 pacientes adultos (entre 18 e 60 anos) com desidratação, variando entre 1 a 6% de perda de massa corporal, foram incluídos nessa análise. Os dados foram utilizados para tentar estimar o tamanho do efeito (effect size, ES) da desidratação na perfomance cognitiva dos participantes.

Desidratação e cognição

O declínio no desempenho cognitivo com desidratação foi pequeno, mas significativo (ES = -0,21; IC de 95%: -0,31 a -0,11; p <0,0001) com heterogeneidade significativa. Tarefas de função executiva (ES = -0,24; -0,37 a -0,12), atenção (ES = -0,52; -0,66 a -0,37) e coordenação motora (ES = -0,40; – 0,63 a -0,17) foram significativamente prejudicados (p ≤ 0,01) após a desidratação.

A perda de massa corporal foi positivamente associada com comprometimento cognitivo (p = 0,04); consequentemente, esse comprometimento foi maior (p = 0,04) em estudos que reportaram > 2% de perda de massa corporal (ES = -0,28, IC95%: [-0,41, -0,16] comparado a ≤ 2% (ES = -0,14, IC95%: [ -0,27, -0,00]).

Pelos achados, os pesquisadores concluíram que:

  • A desidratação prejudica o desempenho cognitivo, principalmente para tarefas que envolvem atenção, função executiva e coordenação motora, e quando há perda de massa corporal de > 2%.

 

Referências:

  • Matthew T. Wittbrodt; Melinda Millard-Stafford. Dehydration Impairs Cognitive Performance: A Meta-analysis. Medicine & Science in Sports & Exercise. Publish Ahead of Print():, JUL 2018. DOI: 10.1249/MSS.0000000000001682

#A bone to pick with prostate cancer

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A bone to pick with prostate cancer

© KATERYNA KON/SCIENCE PHOTO LIBRARY/Getty

© KATERYNA KON/SCIENCE PHOTO LIBRARY/Getty

 

Some types of bone tumours originating from prostate cancer send information to the surrounding cells inducing the formation of rigid bony lesions. Researchers at the Tokyo Medical and Dental University and colleagues have pinpointed one of the messengers.

The team found that the tumours send a small molecule of RNA, called hsa-miR-940, by means of tiny vesicles to surrounding cells. This tiny molecule targets two genes, suppressing the levels of proteins they encode and ultimately turning stem cells in the bone into bone-forming cells.

Bone metastases are a common progression of some types of cancer and can be osteoblastic, forming rigid bony lesions, or osteolytic, causing bone tissue to break down and become thin. Prostate cancer metastases are often osteoblastic, but it has not been entirely clear, until now, how metastatic cells induce the formation of thick bone. Understanding the mechanisms of bone metastasis can lead to the development of drugs that improve patient survival rates.

 

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  1. PNAS 115, 2204–2209 (2018). doi: 10.1073/pnas.1717363115

View the article on the Nature Index

#La #periodontitis incrementa el riesgo de #hipertensión arterial

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  • Noticias Médicas

Un estudio presentado en el congreso EuroPerio9 ha encontrado relación entre la periodontitis y una mayor probabilidad de tener hipertensión arterial

“La periodontitis y la hipertensión afectan a millones de personas en todo el mundo. Ambas condiciones se han relacionado con la incidencia de eventos cardiovasculares. Además, comparten factores de riesgo como la diabetes, la mala alimentación y el tabaquismo. Cada vez hay más pruebas de que la enfermedad de las encías aumenta el riesgo de futuras enfermedades cardiovasculares, independientemente de los factores de confusión como el tabaquismo y la obesidad”, ha explicado la autora principal del estudio, Eva Muñoz Aguilera, especialista en periodoncia en el UCL Eastman Dental Institute de Londres (Reino Unido).

Tal y como comenta la investigadora, estudios previos han sugerido un vínculo entre la periodontitis y la hipertensión, pero se sabía poco sobre el porqué de esta asociación. Por tanto, el objetivo de este nuevo estudio ha sido determinar si los pacientes con periodontitis tenían más probabilidades de ser diagnosticados con hipertensión en comparación con las personas sin periodontitis.

El estudio ha incluido revisión sistemática, que ha investigado el efecto del tratamiento periodontal sobre la presión arterial sistólica y diastólica, así como el nivel de evidencia científica hasta ahora que vincula estas dos patologías. “Desde un punto de vista biológico, esta asociación es posible, ya que los microorganismos que causan la inflamación en la enfermedad de las encías pueden crear inflamación tanto local como sistémica, lo que lleva a daños en los vasos sanguíneos”, ha detallado.

“Si se demuestra que existe un vínculo entre la enfermedad periodontal y la hipertensión, y que es causal, esto nos daría la oportunidad de actuar en el diagnóstico, la prevención y el tratamiento de la enfermedad de las encías con el fin de contribuir, a su vez, en la prevención y el tratamiento de la hipertensión, evitando las complicaciones devastadoras causadas por la presión arterial elevada”, ha señalado la investigadora.

La revisión sistemática ha incluido estudios observacionales y experimentales publicados hasta octubre de 2017. Dos revisores de forma independiente revisaron, seleccionaron y extrajeron los datos de la búsqueda realizada y evaluaron el riesgo de sesgo. También se realizaron estudios más allá de la relación periodontología-hipertensión, extendiendo la búsqueda a artículos sobre enfermedades cardíacas, síndrome metabólico y otras afecciones crónicas y sistémicas relacionadas con la enfermedad de las encías.

Los resultados mostraron que el diagnóstico de periodontitis moderada a severa se asoció con mayor probabilidad, entre un 30 a 50%, de presión arterial alta, y aún más alta en la periodontitis severa. En estudios de cohortes que examinaron la asociación, la periodontitis predijo la aparición de hipertensión.

Por su parte, dos de los tres estudios experimentales incluidos en la revisión confirmaron una reducción de la presión arterial después del tratamiento periodontal. De acuerdo con los resultados, los investigadores estiman que el tratamiento de la enfermedad de las encías en pacientes con presión arterial elevada podría estar en el rango o incluso más alto de lo que se consigue con antihipertensivos

Muñoz Aguilera ha señalado que necesitan más investigación, como estudios longitudinales y ensayos controlados aleatorios con presión arterial como resultado primario, para confirmar este efecto. “Debido al tamaño de muestra requerido para realizar más investigaciones sobre este tema, estos estudios serán costosos. Esperamos unir fuerzas con otros profesionales de la salud para continuar nuestra investigación”, ha resaltado.