Enzyme-Substrate Reactions in Very High Magnetic Fields. II

We have examined the effect of conditioning the enzyme trypsin in solution at pH 8.2 in a large magnetic field before determining its reactivity towards a synthetic substrate N-benzoyl DL-arginine p-nitroanilide (BAPA). This "pretreatment" was allowed to proceed for as long as 3(2/3) hr in a magnetic field of 208 kgauss at temperatures 26 and 36 degrees C. No effect on reactivity was observed when such pretreated enzyme solutions were compared with identical but untreated enzyme solutions. A single such reaction, allowed to proceed directly in a magnetic field of 220 kgauss for 9 min, similarly showed no difference in rate from its control.     

Management of raised blood pressure in New Zealand: a discussion document.

A report to the National Advisory Committee on Core Health and Disability Support Services, New Zealand, on the management of raised blood pressure recommends that decisions to treat raised blood pressure should be based primarily on the estimated absolute risk of cardiovascular disease rather than on blood pressure alone. In general, patients with a blood pressure of 150-170 mm Hg systolic or 90-100 mm Hg diastolic, or both, should be given treatment to lower blood pressure if the risk of a major cardiovascular disease event in 10 years is more than about 20%. The results of clinical trials indicate that, at this level of absolute risk, 150 people would require treatment to reduce the annual number of cardiovascular events by about one. Implementation of these recommendations may result in a smaller proportion of people aged under 60, particularly women, receiving treatment but an increased proportion of older people treated. In the absence of specific contraindications, low dose diuretics and low dose beta blockers should be considered for first line treatment, since for only these drug groups is there direct evidence of reduced risk of stroke and coronary disease in people with raised blood pressure.     

Caregivers’ Attitudes towards HIV Testing and Disclosure of HIV Status to At-Risk Children in Rural Uganda

Caregivers of HIV-positive children were interviewed in the Mbarara and Isingiro districts of Uganda to identify current trends in practices related to HIV testing and the disclosure of HIV status to the child. A total of 28 caregivers of at least one HIV-positive child participated in semi-structured interviews exploring when and why they tested the child for HIV, when the child was informed of their positive status, and what the caregiver did to prepare themselves and the child for status disclosure. For a majority (96%) of respondents, the decision to test the child for HIV was due to existing illness in either the child or a relative. Other common themes identified included the existence of stigma in the caregivers’ communities and doubt that the children truly understood what was being explained to them when their status was disclosed. Most (65%) children were informed of their HIV status between the ages of 5 and 9, with the mean age of disclosure occurring at the age of 7. General provision of HIV information typically began at the same age as disclosure, and as many as two thirds (64%) of the caregivers sought advice from an HIV counsellor prior to disclosure. How a caregiver chose to prepare themselves and the child did not affect the caregiver’s perception of whether the disclosure experience was beneficial or not. These findings suggest that the HIV disclosure experience in Mbarara and Isingiro districts differs from current guidelines, especially with respect to age of disclosure, how caregivers prepare themselves and the child, and approaching disclosure as an ongoing process. The doubts expressed by caregivers regarding the child’s level of HIV understanding following the disclosure experience suggest the children may be insufficiently prepared at the time of the initial disclosure event. The findings also suggest that examining the content of pre-disclosure counselling and HIV education, and how health care professionals are trained to facilitate the disclosure process as important avenues for further research.     

Disentangling the Diversity of Arboreal Ant Communities in Tropical Forest Trees

Tropical canopies are known for their high abundance and diversity of ants. However, the factors which enable coexistence of so many species in trees, and in particular, the role of foragers in determining local diversity, are not well understood. We censused nesting and foraging arboreal ant communities in two 0.32 ha plots of primary and secondary lowland rainforest in New Guinea and explored their species diversity and composition. Null models were used to test if the records of species foraging (but not nesting) in a tree were dependent on the spatial distribution of nests in surrounding trees. In total, 102 ant species from 389 trees occurred in the primary plot compared with only 50 species from 295 trees in the secondary forest plot. However, there was only a small difference in mean ant richness per tree between primary and secondary forest (3.8 and 3.3 sp. respectively) and considerably lower richness per tree was found only when nests were considered (1.5 sp. in both forests). About half of foraging individuals collected in a tree belonged to species which were not nesting in that tree. Null models showed that the ants foraging but not nesting in a tree are more likely to nest in nearby trees than would be expected at random. The effects of both forest stage and tree size traits were similar regardless of whether only foragers, only nests, or both datasets combined were considered. However, relative abundance distributions of species differed between foraging and nesting communities. The primary forest plot was dominated by native ant species, whereas invasive species were common in secondary forest. This study demonstrates the high contribution of foragers to arboreal ant diversity, indicating an important role of connectivity between trees, and also highlights the importance of primary vegetation for the conservation of native ant communities.     

Portrayal of the Human Resource Crisis and Accountability in Healthcare: A Qualitative Analysis of Ugandan Newspapers

Background

Uganda is one of the 57 countries with a critical shortage of health workers. The aim of this study was to determine how the human resources and health service crisis was covered in Ugandan newspapers and, in particular, how the newspapers attributed accountability for problems in the health services.

Methods

We collected all articles related to health workers and health services for the calendar year 2012 in the two largest national newspapers in Uganda (collection on daily basis) and in one local newspaper (collection on weekly basis). These articles were analysed qualitatively regarding the main themes covered and attribution of accountability.

Results

The two more urban national newspapers published 229 articles on human resources and health services in Uganda (on average over two articles per week), whereas the local more rural newspaper published only a single article on this issue in the 12 month period. The majority of articles described problems in the health service without discussing accountability. The question of accountability is raised in only 46% of articles (106 articles). The responsibility of the government was discussed in 50 articles (21%), and negligence, corruption and misbehaviour by individual health workers was reported in 56 articles (25%). In the articles about corruption (n=35), 60% (21 articles) mention corruption by health workers and 40% (14 articles) mention corruption by government officials. Six articles defended the situation of health workers in Uganda.

Conclusions

The coverage of accountability in the Ugandan newspapers surveyed is insufficient to generate informed debate on what political actions need to be taken to improve the crisis in health care and services. There exists not only an “inverse care law” but also an “inverse information law”: those sections of society with the greatest health needs and problems in accessing quality health care receive the least information about health services.     

On the Electron Spin Resonances in DNA

Iron impurities are shown to account for characteristic electron spin resonances observed in samples of DNA. Comparative e.s.r. measurements on lyophilized samples were done in conjunction with static susceptibility measurements, trace analyses, and molecular degradation experiments to establish this correlation. It has not been possible to extract this iron by treatment with a chelating agent. Such resonances were in part accounted for by ferromagnetic iron contamination during extraction and handling. By modifying the method of Kay, Simmons, and Dounce to eliminate or minimize metal contamination—ionic and ferromagnetic—from sources both internal and external to the tissues used, it was possible to prepare iron-free (< 0.0004 per cent Fe), e.s.r.-free (< 0.001 per cent Fe) DNA. The samples showed 20 per cent protein (determined by the indole method), had a molecular weight 4 × 10⁶ and were undenatured according to the density gradient experiment.