Artigos de livre acesso publicados na revista online Plos One, 27/02/2009

O sítio PLoS ONE é uma publicação online, de livre acesso, com destacadas pesquisas científicas, coordenado pela Public Library of Science. Nesta semana merecem destaque várias pesquisas, tais como:

  • Educating and Informing Patients Receiving Psychopharmacological Medications: Are Family Physicians in Pakistan up to the Task?
  • HIV Induces TRAIL Sensitivity in Hepatocytes
  • Examining Agreement between Clinicians when Assessing Sick Children
  • Role of Human-Mediated Dispersal in the Spread of the Pinewood Nematode in China
  • Green Tea Polyphenols Rescue of Brain Defects Induced by Overexpression of DYRK1A
  • Estimating the Worldwide Extent of Illegal Fishing

Educating and Informing Patients Receiving Psychopharmacological Medications: Are Family Physicians in Pakistan up to the Task?


Studies have shown a high prevalence of psychiatric illnesses among patients in primary health care settings. Family physicians have a fundamental role in managing psychiatric illness with psychopharmacological medications. Providing information about the disease, its management and the potential adverse effects of the medications is an important part of the management of mental illnesses. Our objective was to determine if patients who were prescribed psychopharmacological drugs by family physicians at a community health center in Karachi, Pakistan were provided adequate education about their disease and its management.

A cross-sectional study was conducted at the Community Health Centre (CHC), Aga Khan University Hospital Karachi, Pakistan. Details about the prescriptions and patient education were acquired from the patients after their consultations.

A total of 354 adult patients were interviewed during 3 days. Among them, 73 (20.6%) were prescribed psychopharmacological medications. Among patients receiving psychopharmacological medicines, 37 (50.7%) did not know their diagnosis; 50 (68.5%) were unaware of the disease process; 52 (71.2%) were unaware of alternative treatments; 63 (86.3%) were not cautioned about the potential adverse effects of the drugs; 24 (32.9%) were unaware of the duration of treatment and in 60 (82.2%) of the participants an appropriate referral had not been discussed. For all aspects of education, patients prescribed psychopharmacological medications knew less as compared to those patients that were prescribed other medications.

The practice of imparting information to patients who receive psychopharmacological medications seems to be inadequate in Pakistan. We have hypothesized about the possible reasons for our findings, and identified a need for further research to determine the cause for such findings and to address them accordingly. At the same time there is a need to educate family physicians in Pakistan about the special importance of providing adequate information to such patients.

HIV Induces TRAIL Sensitivity in Hepatocytes


HIV infected patients have an increased susceptibility to liver disease due to Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), alcoholic, and non-alcoholic steatohepatitis. Clinically, this results in limited options for antiretroviral therapy and accelerated rates of liver disease, causing liver disease to be the second leading cause of death for HIV infected patients. The mechanisms causing this propensity for liver dysfunction during HIV remains unknown.

Methodology/Principal Findings
We demonstrate that HIV and/or the HIV glycoprotein gp120 ligation of CXCR4 on hepatocytes selectively up-regulates TRAIL R2 expression and confers an acquired sensitivity to TRAIL mediated apoptosis which is mediated by JNK II, but not p38 nor G-proteins.

These findings suggest that HIV infection renders hepatocytes more susceptible to liver injury during disease states associated with enhanced TRAIL production such as HBV, HCV, or steatohepatitis.

Examining Agreement between Clinicians when Assessing Sick Children


Case management guidelines use a limited set of clinical features to guide assessment and treatment for common childhood diseases in poor countries. Using video records of clinical signs we assessed agreement among experts and assessed whether Kenyan health workers could identify signs defined by expert consensus.

104 videos representing 11 clinical sign categories were presented to experts using a web questionnaire. Proportionate agreement and agreement beyond chance were calculated using kappa and the AC1 statistic. 31 videos were selected and presented to local health workers, 20 for which experts had demonstrated clear agreement and 11 for which experts could not demonstrate agreement.

Principal Findings
Experts reached very high level of chance adjusted agreement for some videos while for a few videos no agreement beyond chance was found. Where experts agreed Kenyan hospital staff of all cadres recognised signs with high mean sensitivity and specificity (sensitivity: 0.897–0.975, specificity: 0.813–0.894); years of experience, gender and hospital had no influence on mean sensitivity or specificity. Local health workers did not agree on videos where experts had low or no agreement. Results of different agreement statistics for multiple observers, the AC1 and Fleiss’ kappa, differ across the range of proportionate agreement.

Videos provide a useful means to test agreement amongst geographically diverse groups of health workers. Kenyan health workers are in agreement with experts where clinical signs are clear-cut supporting the potential value of assessment and management guidelines. However, clinical signs are not always clear-cut. Video recordings offer one means to help standardise interpretation of clinical signs.

Role of Human-Mediated Dispersal in the Spread of the Pinewood Nematode in China


Intensification of world trade is responsible for an increase in the number of alien species introductions. Human-mediated dispersal promotes not only introductions but also expansion of the species distribution via long-distance dispersal. Thus, understanding the role of anthropogenic pathways in the spread of invading species has become one of the most important challenges nowadays.

Methodology/Principal Findings
We analysed the invasion pattern of the pinewood nematode in China based on invasion data from 1982 to 2005 and monitoring data on 7 locations over 15 years. Short distance spread mediated by long-horned beetles was estimated at 7.5 km per year. Infested sites located further away represented more than 90% of observations and the mean long distance spread was estimated at 111–339 km. Railways, river ports, and lakes had significant effects on the spread pattern. Human population density levels explained 87% of the variation in the invasion probability (P<0.05). Since 2001, the number of new records of the nematode was multiplied by a factor of 5 and the spread distance by a factor of 2. We combined a diffusion model to describe the short distance spread with a stochastic, individual based model to describe the long distance jumps. This combined model generated an error of only 13% when used to predict the presence of the nematode. Under two climate scenarios (stable climate or moderate warming), projections of the invasion probability suggest that this pest could expand its distribution 40–55% by 2025.

This study provides evidence that human-induced dispersal plays a fundamental role in the spread of the pinewood nematode, and appropriate control measures should be taken to stop or slow its expansion. This model can be applied to Europe, where the nematode had been introduced later, and is currently expanding its distribution. Similar models could also be derived for other species that could be accidentally transported by humans.

Green Tea Polyphenols Rescue of Brain Defects Induced by Overexpression of DYRK1A


Individuals with partial HSA21 trisomies and mice with partial MMU16 trisomies containing an extra copy of the DYRK1A gene present various alterations in brain morphogenesis. They present also learning impairments modeling those encountered in Down syndrome. Previous MRI and histological analyses of a transgenic mice generated using a human YAC construct that contains five genes including DYRK1A reveal that DYRK1A is involved, during development, in the control of brain volume and cell density of specific brain regions. Gene dosage correction induces a rescue of the brain volume alterations. DYRK1A is also involved in the control of synaptic plasticity and memory consolidation. Increased gene dosage results in brain morphogenesis defects, low BDNF levels and mnemonic deficits in these mice. Epigallocatechin gallate (EGCG) — a member of a natural polyphenols family, found in great amount in green tea leaves — is a specific and safe DYRK1A inhibitor. We maintained control and transgenic mice overexpressing DYRK1A on two different polyphenol-based diets, from gestation to adulthood. The major features of the transgenic phenotype were rescued in these mice.

Estimating the Worldwide Extent of Illegal Fishing


Illegal and unreported fishing contributes to overexploitation of fish stocks and is a hindrance to the recovery of fish populations and ecosystems. This study is the first to undertake a world-wide analysis of illegal and unreported fishing. Reviewing the situation in 54 countries and on the high seas, we estimate that lower and upper estimates of the total value of current illegal and unreported fishing losses worldwide are between $10 bn and $23.5 bn annually, representing between 11 and 26 million tonnes. Our data are of sufficient resolution to detect regional differences in the level and trend of illegal fishing over the last 20 years, and we can report a significant correlation between governance and the level of illegal fishing. Developing countries are most at risk from illegal fishing, with total estimated catches in West Africa being 40% higher than reported catches. Such levels of exploitation severely hamper the sustainable management of marine ecosystems. Although there have been some successes in reducing the level of illegal fishing in some areas, these developments are relatively recent and follow growing international focus on the problem. This paper provides the baseline against which successful action to curb illegal fishing can be judged.

[EcoDebate, 02/03/2009]

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