Heterozygosity for CCR5-Delta32 but not CCR2b-64I protects against certain intracellular pathogens

OBJECTIVE

To determine the association between CCR5 and CCR2b genotype and the clinical manifestation of first and subsequent AIDS-defining illnesses (ADIs).

METHODS

The distribution of ADIs was examined by CCR5 and CCR2b genotype in a subset of homosexual men enrolled in the Sydney AIDS Prospective Study. The expected number of ADIs was calculated from rates observed in the same tertiary hospital over the same period.

RESULTS

Information on initial ADI was collected for 117 homosexual men diagnosed with AIDS before January 1998. Of these individuals, 17 were heterozygous for the CCR5-Delta32 mutation and 11 were heterozygous for CCR2b-64I. The number of observed cases of Pneumocystis carinii pneumonia (PCP), toxoplasmosis, Mycobacterium avium complex (MAC) and cryptosporidiosis reported as a first ADI was substantially fewer in people heterozygous for the CCR5-Delta32 mutation than for those without the mutation, despite similar age, CD4 T-cell count at AIDS diagnosis, year of AIDS diagnosis and receipt of antiretroviral treatment. In addition, among individuals heterozygous for CCR5-Delta32 there were fewer cases of PCP, toxoplasmosis, MAC, and cryptosporidiosis observed as subsequent ADIs compared to the number expected, based on rates measured in the same hospital during the same period (seven observed vs. 24 expected, RR = 0.3, 95% CI = 0.01-0.6). The distribution of first and subsequent ADIs did not differ from the number expected in individuals heterozygous for the CCR2b-64I mutation.

CONCLUSION

Results from this study show that heterozygosity for CCR5-Delta32 but not CCR2b-64I appears to protect against opportunistic infections.

Dynamic contrast-enhanced T2*-weighted MR imaging of gliomatosis cerebri

BACKGROUND AND PURPOSE

MR imaging characteristics of gliomatosis cerebri reiterate the diffuse nature of this tumor but are nonspecific and thus may pose a diagnostic challenge. Because perfusion MR imaging can provide a physiologic map of the microcirculation, we compared the measured relative cerebral blood volume (rCBV) at perfusion imaging with histopathologic findings in gliomatosis cerebri. MR spectroscopic findings were also reviewed.

METHODS

Retrospective analysis was performed of conventional and perfusion MR images from seven patients with proved gliomatosis cerebri. The conventional MR images were evaluated for the presence or absence of contrast enhancement, necrosis, and extent of T2-weighted signal intensity abnormality. Dynamic contrast-enhanced T2*-weighted gradient-echo echo-planar images were acquired during the first pass of a bolus injection of gadopentetate dimeglumine. The rCBV was calculated by using nondiffusible tracer kinetics and expressed relative to normal-appearing white matter. Pathologic findings were reviewed in all patients and compared with the MR perfusion data. Multivoxel 2D chemical shift imaging proton MR spectroscopic data were available for three patients and single-voxel data for one patient.

RESULTS

Conventional MR images showed diffuse abnormality in all cases and absence of contrast enhancement in all but one case. Average rCBV range was 0.75-1.26 (mean, 1.02 +/- 0.42 [SD]). MR spectroscopic data revealed spectra consistent with presence of tumoral disease. Histopathologic review showed absence of vascular hyperplasia in all specimens.

CONCLUSION

The low MR rCBV measurements of gliomatosis cerebri are in concordance with the lack of vascular hyperplasia found at histopathologic examination; thus, perfusion MR imaging provides useful adjunctive information that is not available from conventional MR imaging techniques.

Insertional mutagenesis of genes required for seed development in Arabidopsis thaliana

The purpose of this project was to identify large numbers of Arabidopsis genes with essential functions during seed development. More than 120,000 T-DNA insertion lines were generated following Agrobacterium-mediated transformation. Transgenic plants were screened for defective seeds and putative mutants were subjected to detailed analysis in subsequent generations. Plasmid rescue and TAIL-PCR were used to recover plant sequences flanking insertion sites in tagged mutants. More than 4200 mutants with a wide range of seed phenotypes were identified. Over 1700 of these mutants were analyzed in detail. The 350 tagged embryo-defective (emb) mutants identified to date represent a significant advance toward saturation mutagenesis of EMB genes in Arabidopsis. Plant sequences adjacent to T-DNA borders in mutants with confirmed insertion sites were used to map genome locations and establish tentative identities for 167 EMB genes with diverse biological functions. The frequency of duplicate mutant alleles recovered is consistent with a relatively small number of essential (EMB) genes with nonredundant functions during seed development. Other functions critical to seed development in Arabidopsis may be protected from deleterious mutations by extensive genome duplications.

Arabidopsis genes essential for seedling viability: isolation of insertional mutants and molecular cloning

We have undertaken a large-scale genetic screen to identify genes with a seedling-lethal mutant phenotype. From screening approximately 38,000 insertional mutant lines, we identified >500 seedling-lethal mutants, completed cosegregation analysis of the insertion and the lethal phenotype for >200 mutants, molecularly characterized 54 mutants, and provided a detailed description for 22 of them. Most of the seedling-lethal mutants seem to affect chloroplast function because they display altered pigmentation and affect genes encoding proteins predicted to have chloroplast localization. Although a high level of functional redundancy in Arabidopsis might be expected because 65% of genes are members of gene families, we found that 41% of the essential genes found in this study are members of Arabidopsis gene families. In addition, we isolated several interesting classes of mutants and genes. We found three mutants in the recently discovered nonmevalonate isoprenoid biosynthetic pathway and mutants disrupting genes similar to Tic40 and tatC, which are likely to be involved in chloroplast protein translocation. Finally, we directly compared T-DNA and Ac/Ds transposon mutagenesis methods in Arabidopsis on a genome scale. In each population, we found only about one-third of the insertion mutations cosegregated with a mutant phenotype.

Baseline antiretroviral drug susceptibility influences treatment response in patients receiving saquinavir-enhancing therapy

PURPOSE

To relate baseline plasma HIV genotypic and virtual phenotypic antiretroviral drug susceptibility to subsequent virological response in patients receiving saquinavir (SQV)-enhancing therapy. Individuals were randomized to receive stavudine (d4T), SQV, and one of ritonavir, nelfinavir, or delavirdine to enhance SQV blood levels.

METHOD

The protease and reverse transcriptase baseline sequences of 31 treatment-experienced patients were analyzed by genotype and virtual phenotype and were related to viral load at weeks 12 and 24. Genotypic resistance to SQV was defined by the presence of G48V and/or L90M mutations in the protease gene. Potential cross-resistance to d4T in zidovudine (ZDV)-experienced individuals was defined by the presence of thymidine-associated mutations in the reverse transcriptase gene.

RESULTS

ZDV-associated mutations did not affect the virological response at 24 weeks. Individuals who were sensitive to SQV at baseline as determined by either genotyping or virtual phenotyping showed a greater decrease in viral load at week 24 than those resistant to SQV, irrespective of treatment arm. By genotyping, SQV-sensitive individuals had a median log decrease of 1.12 compared to 0.32 for those individuals who were SQV resistant. By virtual phenotyping, SQV-sensitive individuals had a median log decrease of 1.0 compared to a rise of 0.08 in resistant individuals.

CONCLUSION

Thymidine analogue-associated mutations at baseline did not influence the response to subsequent therapy involving d4T. Individuals who were sensitive or resistant to SQV by genotyping or virtual phenotyping responded to SQV-enhancing regimens, but the virological response was greater in those who were sensitive.

Health-related quality of life in childhood disorders: a modified focus group technique to involve children

OBJECTIVES

Qualitative methodology has been under-utilized in child health research due to lack of a specific set of instruments. The objective of this study was to develop a child-centred qualitative research methodology to facilitate direct exploration of health-related quality of life (HRQL) issues and to identify the quality of life elements in pre-adolescent children with a chronic medical condition.

STUDY DESIGN

Purposeful stratified sampling of children, ages 6-12, who function in a regular school class, with active epilepsy who were assembled in small focus groups. The groups met in four phases and were led by moderators who probed preset open questions and activities.

RESULTS

The study demonstrated that our modified focus groups process was a powerful exploratory experience eliciting meaningful and important issues in quality of life beyond what parents and health professionals expected, and helped identify HRQL elements in childhood epilepsy.

CONCLUSION

Modified focus groups are appropriate and suitable to explore quality of life issues in pre-adolescent children with a chronic medical condition. The process is feasible and trustworthy.

Differential diagnosis of ulcerative lesions in fish

Tissues such as skin and muscle have a limited repertoire of morphological response to injury. The two most important phenomena that determine the outcome of cell injury appear to be a) critical cell membrane damage, with associated fluid and ionic imbalances; and b) inability of mitochondria, the powerhouse of the cell, to restart ATP synthesis. In fish, skin ulcers can have many different etiologies, including infectious agents, toxins, physical causes, immunologic causes, and nutritional and metabolic perturbations. This article is concerned primarily with the possible pathways of disease involved in ulcerative lesions of fish. In particular, the high prevalence of ulcerative lesions in Atlantic menhaden found along the mid-Atlantic coast, especially in North Carolina estuarine waters, has received much recent attention. These ulcerative lesions are likely to be initiated by a series of factors that lead ultimately to a breach of the normal barrier function of the skin. Bioassays that attempt to define the role of individual etiologic agents such as fungi (oomycetes) or putative Pfiesteria toxin(s) should recognize this multiplicity of factors and should include appropriate quality control measures for water quality parameters (temperature, dissolved oxygen, nitrogenous wastes, etc.) as well as bacterial and other contaminants that may confound bioassay results and their interpretation. Consideration of these factors along with the whole animal in the context of its environment can only advance the science, perhaps provide clues to the causative pathways of skin ulcers in fish, and give us keener insight into the health of the aquatic environment.

HIV protease inhibitor substitution in patients with lipodystrophy: a randomized, controlled, open-label, multicentre study

BACKGROUND

Lipodystrophy, dyslipidaemia and insulin resistance often complicate protease inhibitor-containing antiretroviral therapy. The aims of this study were to determine if these are reversible with continued HIV suppression following protease inhibitor substitution.

METHODS

Eighty-one HIV protease inhibitor recipients (78 male; mean antiretroviral therapy, 55 months) with predominant peripheral lipoatrophy, HIV RNA < 400 copies/ml plasma for at least the preceding 6 months, and no prior abacavir, non-nucleoside analogue or adefovir therapy were randomized 3 : 2 to continue nucleoside analogues and substitute protease inhibitor(s) with abacavir, nevirapine, adefovir and hydroxyurea (n = 49) or to continue all therapy (n = 32) with an option to switch at week 24. The primary endpoints were total body fat and HIV RNA at week 24. Other assessments were regimen safety, regional body composition, metabolic parameters, quality of life, and CD4 T-lymphocyte counts to week 48.

RESULTS

There was a greater decline in total body fat in the switch group than in the continue group (-1.6 and -0.4 kg, respectively at week 24; P = 0.006). This comprised greater declines in limb and subcutaneous abdominal fat, and in intra-abdominal fat of patients with moderate or severe abdominal fat accumulation. Viral suppression was similar, despite 18 (37%) switch group patients ceasing at least one study drug by week 24 because of adverse events. Total cholesterol and triglycerides declined more in the switch group (both P < 0.002). High density lipoprotein cholesterol increased significantly in both groups at week 48 (P < 0.02). There was no change for any glycaemic parameter.

CONCLUSIONS

In predominantly lipoatrophic patients, switching from HIV protease inhibitor therapy lead to improved lipids and less intra-abdominal fat, but also to less peripheral fat, and had minimal effect on insulin resistance. Virological control in these heavily pretreated patients was unaffected, despite frequent switch drug cessations.

Vaccinia virus utilizes microtubules for movement to the cell surface

Vaccinia virus (VV) egress has been studied using confocal, video, and electron microscopy. Previously, intracellular-enveloped virus (IEV) particles were proposed to induce the polymerization of actin tails, which propel IEV particles to the cell surface. However, data presented support an alternative model in which microtubules transport virions to the cell surface and actin tails form beneath cell-associated enveloped virus (CEV) particles at the cell surface. Thus, VV is unique in using both microtubules and actin filaments for egress. The following data support this proposal. (a) Microscopy detected actin tails at the surface but not the center of cells. (b) VV mutants lacking the A33R, A34R, or A36R proteins are unable to induce actin tail formation but produce CEV and extracellular-enveloped virus. (c) CEV formation is inhibited by nocodazole but not cytochalasin D or 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo(3,4-d)pyrimidine (PP1). (d) IEV particles tagged with the enhanced green fluorescent protein fused to the VV B5R protein moved inside cells at 60 microm/min. This movement was stop-start, was along defined pathways, and was inhibited reversibly by nocodazole. This velocity was 20-fold greater than VV movement on actin tails and consonant with the rate of movement of organelles along microtubules.

Distribution, prevalence, and relative risk of filariasis in dogs from the State of Washington (1997-1999)

Using antigen capture and filter tests, 6,078 dogs throughout the state of Washington were examined for filariasis between July 1, 1997 and October 31, 1999. In western Washington, 791 males and 901 females examined were outdoors, not on prophylaxis, and had traveled out of the state; 6/791 (0.8%) males and 7/901 (0.8%) females were infected with Dirofilaria immitis (D. immitis), and one (0.1%) male and one (0.1%) female were infected with Dipetalonema reconditum (D. reconditum). There were also 392 males and 362 females examined that were outdoors, not on prophylaxis, and had not traveled out of western Washington. One (0.1%) female was infected with D. immitis, and two (0.5%) males and one (0.2%) female were infected with D. reconditum. In eastern Washington, 707 males and 826 females examined were outdoors, not on prophylaxis, and had traveled out of the state; 9/707 (1.0%) males and 4/826 (0.5%) females were infected with D. immitis, and no D. reconditum was found. There were also 376 males and 412 females examined that were outdoors, not on prophylaxis, and had not traveled out of the state. Three (0.8%) males and three (0.7%) females had D. immitis. One (0.2%) female had D. reconditum. Distribution of D. immitis-infected, nontravel dogs in eastern Washington was only found between 120 degrees and 119 degrees west longitude in the communities of Richland, Moses Lake, Okanogan, and Omak. Enzootic transmission of D. immitis and D. reconditum is occurring in both eastern and western Washington.

Issues in bidding for contracts for occupational therapy services

There is an increasing number of occupational therapists in Canada who are involved in bidding for contracts to deliver occupational therapy services. Occupational therapists working in an institutional or community-based setting may not have had the responsibility of developing a proposal or a marketing plan for bidding purposes. However, the responsibility of developing a bid to compete for a service delivery contract often rests on occupational therapists who are sole practitioners in a private practice setting. The purpose of this paper is to highlight issues in the literature such as service delivery plans, marketing strategies and costing of services that can assist the occupational therapist in the development of a contractual bid. A specific clinical example, school therapy services, has been used to illustrate how these strategies can be applied to practice. Success in contractual bids appears to be primarily influenced by cost of the service, the expertise of the service provider, ability to provide coordinated care, ease of access for clients, and inclusion of methods to measure client outcome.

Detection of 1p and 19q loss in oligodendroglioma by quantitative microsatellite analysis, a real-time quantitative polymerase chain reaction assay

The combined loss of chromosomes 1p and 19q has recently emerged as a genetic predictor of chemosensitivity in anaplastic oligodendrogliomas. Here, we describe a strategy that uses a novel method of real-time quantitative polymerase chain reaction, quantitative microsatellite analysis (QuMA), for the molecular analysis of 1p and 19q loss in oligodendrogliomas and oligoastrocytomas in archival routinely processed paraffin material. QuMA is performed on the ABI 7700 and based on amplifications of microsatellite loci that contain (CA)n repeats where the repeat itself is the target for hybridization by the fluorescently labeled probe. This single probe can therefore be used to determine copy number of microsatellite loci spread throughout the human genome. In genomic DNA prepared from paraffin-embedded brain tumor specimens, QuMA detected combined loss of 1p and 19q in 64% (21 of 32) of oligodendrogliomas and 67% (6 of 9) of oligoastrocytomas. We validate the use of QuMA as a reliable method to detect copy number by showing concordance between QuMA and fluorescence in situ hybridization at 37 of 45 chromosomal arms tested. These results indicate that QuMA is an accurate, high-throughput assay for the detection of copy number at multiple loci; as many as 31 loci of an individual tumor can be analyzed on a 96-well plate in a single 2-hour run. In addition, it has advantages over standard allelic imbalance/loss of heterozygosity assays in that all loci are potentially informative, paired normal tissue is not required, and gain can be distinguished from loss. QuMA may therefore be a powerful molecular tool to expedite the genotypic analysis of human gliomas in a clinical setting for diagnostic/prognostic purposes.

Randomized trial of folic acid supplementation and serum homocysteine levels

BACKGROUND

Lowering serum homocysteine levels with folic acid is expected to reduce mortality from ischemic heart disease. Homocysteine reduction is known to be maximal at a folic acid dosage of 1 mg/d, but the effect of lower doses (relevant to food fortification) is unclear.

METHODS

We randomized 151 patients with ischemic heart disease to 1 of 5 dosages of folic acid (0.2, 0.4, 0.6, 0.8, and 1.0 mg/d) or placebo. Fasting blood samples for serum homocysteine and serum folate analysis were taken initially, after 3 months of supplementation, and 3 months after folic acid use was discontinued.

RESULTS

Median serum homocysteine level decreased with increasing folic acid dosage, to a maximum at 0.8 mg of folic acid per day, when the homocysteine reduction (placebo adjusted) was 2.7 micromol/L (23%), similar to the known effect of folic acid dosages of 1 mg/d and above. The higher a person's initial serum homocysteine level, the greater was the response to folic acid, but there were statistically significant reductions regardless of the initial level. Serum folate level increased approximately linearly (5.5 nmol/L for every 0.1 mg of folic acid). Within-person fluctuations over time in serum homocysteine levels, measured in the placebo group, were large compared with the effect of folic acid, indicating that monitoring of the reduction in an individual is impractical.

CONCLUSIONS

A dosage of folic acid of 0.8 mg/d appears necessary to achieve the maximum reduction in serum homocysteine level across the range of homocysteine levels in the population. Current US food fortification levels will achieve only a small proportion of the achievable homocysteine reduction.

Fortifying food with folic acid

Folic acid supplementation may help prevent the following three common and important disorders: neural tube defect pregnancies, ischemic heart disease and strokes, and possibly colon cancer. Several studies have irrefutably established that folic acid supplementation in proper doses reduces neural tube defect pregnancies. Fortified food would be the most reliable way to address this health issue. Several epidemiologic reports have established a close link between hyperhomocysteinemia and ischemic heart disease. This is supported by evidence obtained from genetic defects leading to elevated plasma levels of homocysteine. There is reasonable evidence to conclude that hyperhomocysteinemia is the actual cause of excessive cardiac diseases. Again, folic acid supplementation in proper doses could potentially reduce ischemic heart disease by 40% There is also some evidence to suggest that folic acid treatment reduces the incidence of colon cancer. The reduction in all three health problems is dependent upon the dose of folic acid administered. The levels needed are rarely supplied by the daily food intake, even under ideal conditions, although breakfast cereals address this problem at least in part. It is proposed that flour be fortified because it is a food product heavily used by most people, and that governmental agencies should oversee such programs because they are responsible for setting public health policies.

A randomized trial of nelfinavir, ritonavir, or delavirdine in combination with saquinavir-SGC and stavudine in treatment-experienced HIV-1-infected patients

PURPOSE

To evaluate the 24-week impact of saquinavir-enhancing antiretroviral therapy on viral replication in patients previously treated with nucleoside analogues with or without prior saquinavir hard-gel capsules (HGC).

METHOD

Patients were randomized in three groups to receive the following: Group 1-nelfinavir (750 mg tid), saquinavir soft-gel capsule (SGC) (800 mg tid), and stavudine (40 mg bid); Group II-ritonavir (400 mg bid), saquinavir-SGC (400 mg bid), and stavudine (40 mg bid); or Group III-delavirdine (400 mg tid), saquinavir-SGC (800 mg tid), and stavudine (40 mg bid). Viral loads, CD4 count, and safety were assessed over a 24-week period with an additional 6-month follow-up.

RESULTS

73 patients received randomized therapy; 14 of whom were SQV naïve, with a median baseline viral load of 3.6 log(10) and a CD4 count of 370 cells/mm(3). By 6 months, the median decreases in plasma viral loads were 0.26, 0.71, and 0.29 log(10) copies/mL for groups I, II, and III, respectively. The median increases in CD4 counts, for groups I, II, and III, were 52, 40, and 69 cells/mm(3) at 6 months, respectively. Changes in viral load and CD4 counts at 6 months and 1 year were not significantly different between the treatment groups. More patients discontinued therapy in the ritonavir arm (35%) for drug intolerance or toxicity compared to either the nelfinavir or delavirdine arms (15% and 5%, respectively). In a multivariate analysis, baseline viral load, younger age, and baseline saquinavir resistance were significantly associated with detectable viral load at 24 weeks.

CONCLUSION

The use of antiretroviral agents that pharmacokinetically boost saquinavir levels has a modest benefit in saquinavir-experienced patients.

Antibody neutralization of the extracellular enveloped form of vaccinia virus

The extracellular enveloped form (EEV) of vaccinia virus (VV) is important for the long-range dissemination of the virus inside the host. Early work suggested that both IMV and EEV infectivity could be inhibited by antibodies, although two other studies reported that EEV was resistant to neutralization. Here, we readdressed this question, using four VV-immune antisera and their purified IgG, and showed that EEV infectivity can be inhibited by antibody produced from a live infection in plaque-reduction assays, although EEV is more resistant to neutralization by convalescent antibodies than is IMV. In parallel, indirect immunofluorescent staining and confocal microscopy showed that antibody aggregated EEV and prevented it from binding to cells. Using the IgG and Fab fragments prepared from this antiserum, we tested whether EEV made by VV mutants lacking genes A33R, A34R, A36R, A56R, B5R, F12L, or F13L can be inhibited in plaque-reduction assays. Although vDeltaB5R was slightly more resistant than other mutants, none of these mutants escaped neutralization completely, suggesting that multiple virus proteins are involved in the inhibition. Using an antibody specific to B5R protein and B5R mutants with consecutive short consensus repeat (SCR) domains deleted, the neutralization epitopes on B5R were mapped to within the SCR domain 1.

Incident sexually transmitted infections and their risk factors in an Aboriginal community in Australia: a population based cohort study

OBJECTIVE

To identify risk factors for incident sexually transmitted infections (STI) in a remote Aboriginal community in Australia.

DESIGN

A population based cohort study.

SETTING

An Aboriginal community in central Australia.

PARTICIPANTS

1034 Aboriginal people aged 12-40 years, resident in the study region, seen during the period 1 January 1996 to 30 June 1998 for STI diagnosis.

MAIN OUTCOME MEASURES

Incident rate of gonorrhoea, chlamydia, and syphilis per 100 person years.

RESULTS

There were 313 episodes of incident gonorrhoea, 240 of incident chlamydial infection, and 17 of incident syphilis. For gonorrhoea, risk factors were age, substance abuse, and previous prevalent chlamydial infection with a rate ratio (RR) of 3.2 in people aged 15-19 years, 1.6 in people who abused alcohol, and 3.2 in women who had sniffed petrol on a regular basis. For chlamydia, risk factors were sex, age, and a previous history of STI with a RR of 2.7 in people aged 15-19 years. Similar factors were associated with an increased risk of syphilis but the associations were not statistically significant.

CONCLUSION

This study identified objective predictors of incident STI which can be used to target interventions and maximise their impact. The results of this study may well have relevance to indigenous communities in other countries that are faced with high levels of STI and substance abuse.

Onchocerciasis in a nonendemic population: clinical and immunologic assessment before treatment and at the time of presumed cure

Although suppressive therapy for onchocerciasis with intermittent ivermectin prevents the development of pathology in endemic populations, the clinical and immunologic effects of therapy in the absence of continued exposure are unknown. To address this question, 14 patients treated with ivermectin for onchocerciasis acquired >10 years ago during temporary residence in Africa were reevaluated. None had evidence of continued infection or pathology at follow-up. Although eosinophilia, serum IgE, and antifilarial antibody levels decreased after ivermectin therapy, none of these parameters was useful in predicting the resolution of symptoms in infected patients. Peripheral blood mononuclear cells isolated from patients at follow-up were more responsive to parasite antigen in vitro, which is as assessed by proliferation and production of interferon-gamma and interleukin (IL)-5. In contrast, antigen-induced levels of IL-10 were significantly decreased at follow-up, consistent with diminished down-regulatory factors rather than a switch from type 2 to type 1 immune responses.

The perceived effects of parent-led support groups for parents of children with disabilities

Parent-led support groups for parents who have children with disabilities are voluntary organizations with goals to provide social support and information and to foster advocacy. The purpose of this study was to explore parents' perceptions of the effect of parent-led support groups in providing parents with support and knowledge and in improving parents' ability to deal with childhood disability issues. Qualitative methods were used to examine the experiences of members of nine parent-run support groups. From these groups, 20 parents were interviewed about the benefits and limitations of participation in support group. Information was also collected by observing support group meetings and reviewing group documents. Interview, observation, and document data were analysed to identify emerging themes. Results of the study indicated that the effects of belonging to a parent-led parent support group were substantial. Through these groups, parents gain increased skills, an increased sense of power and a sense of belonging. Participants are able to connect with each other and provide support and skills to deal with the day-to-day issues of raising a child with disabilities.

Impact of environmental sensitivity on occupational performance

Environmental sensitivity is a multi-system disorder characterized by adverse reactions to certain foods, chemicals, and environmental agents. In this study, the impact of environmental sensitivity on the person, environment, and occupation, as well as on occupational performance and time use, was determined. Using qualitative methods, 12 participants with environmental sensitivity were interviewed during a 2-month period. A time-use diary of activities over a 24-hour period was obtained and compared with a survey conducted by Statistics Canada. Textual analysis was conducted by examining and coding data for emerging themes. Finally, the data were interpreted using the Person-Environment-Occupation Model (Law et al., 1996). Findings suggest a multiple-system involvement that leads to changes in type, time, and location of self-care, productive, and leisure occupations. Changes to personal health, environment, and occupations contributed to a decline in occupational performance. Enabling and constraining factors influenced the adaptation to changes in occupational performance. Emerging themes included an initial struggle for legitimacy, societal stigma, isolation, financial strain, and loss of personal expression. Management of environmental sensitivity involved making personal, environmental, and occupational changes. Possible roles for occupational therapists encompass issues of pacing, energy conservation, environmental changes, job modification, and matching occupational interests with personal abilities.

Dietary fat and adult diseases and the implications for childhood nutrition: an epidemiologic approach

Reducing dietary saturated fat by 7% of energy, a realistic target, would reduce serum cholesterol by 10% and mortality from ischemic heart disease by 25-30%. Randomized trials show that this mortality reduction is attained rapidly, usually by the third year after initial reduction of dietary saturated fat intake. Dietary change in adulthood may therefore reverse the adverse health effects of a high-fat diet in childhood. In the absence of such change, however, dietary fat in childhood may increase the risk of cardiovascular disease in adult life because of a longer duration of exposure to a high-fat diet. Assessing the effects of diet on cancer risk is more difficult. The intermediary markers of risk that are analogous to serum cholesterol are less satisfactory and there are negligible trial data. Cohort studies of diet and cancer, although subject to bias, do not favor a direct causal relation between dietary fat and cancer. But a reduction in risk is likely when dietary fat is reduced as part of a general change toward a healthier diet. The trend toward increased energy intake and body size in childhood and relatively low dietary fiber contribute to the decreasing age at menarche, which is associated with an increased risk of breast cancer. Low dietary fiber, low fruit and vegetable consumption, and high red meat consumption are associated with colon cancer and other cancers, and important causal effects of diet on cancer are likely. As with cardiovascular disease, this dietary trend that is commenced in childhood is likely to increase age-specific rates of colon cancer in adult life, but the risk may be reversed with later dietary change.

The use of a simulated environment (easy street) to retrain independent living skills in elderly persons: a randomized controlled trial

BACKGROUND

Older adults who receive training for functional skills in contextually appropriate environments may show greater functional improvement than persons trained in a traditional environment. Functionally limited older adults receiving training in contextually appropriate environments (simulated home and community settings) may show greater improvement in activities of daily living (ADL) than persons trained in a traditional manner.

METHODS

Eighty-eight patients from a day hospital, aged 65 years or older, were randomized to either receive rehabilitation in a simulated environment (Easy Street) or in a gymnasium setting. Rehabilitation focused on retraining functional skills in a contextually appropriate environment (Easy Street) or in a traditional setting (gymnasium) using motor learning principles for a period of 16 weeks. Outcome measures included the Structured Assessment of Instrumental Living Skills (SAILS), a performance measure with criterion and timed components; a self-report health status questionnaire, the Short Form-36 (SF-36); and the patient-orientated goal-directed Canadian Occupational Performance Measure (COPM).

RESULTS

There were no group differences on any of the outcome measures: SAILS (p = .3); the SF-36 physical (p = .83) and mental (p = .51); and the COPM performance scale (p = .94) and satisfaction scale (p = .40).

CONCLUSIONS

Although we have not excluded benefits of contextually appropriate rehabilitation environments with different intervention approaches, at different stages of rehabilitation or with patients at higher functional levels, our results suggest the appropriateness of a moratorium on these expensive interventions pending demonstration of clear positive effects determined from further study.

Recombinant maize protoporphyrinogen IX oxidase expressed in Escherichia coli forms complexes with GroEL and DnaK chaperones

The clone corresponding to maize plastidic protoporphyrinogen IX oxidase (PPO) has been isolated by functional complementation and inserted into a pET16b vector for expression in Escherichia coli. Recombinant PPO was purified by standard affinity chromatography using a metal chelating resin. Two contaminants copurified with recombinant PPO and were identified as GroEL and DnaK. Since chaperone binding to hydrophobic regions of the protein is regulated by ATP availability, an ATP washing step was introduced prior to elution of the recombinant protein from an affinity column. This washing step selectively removed both chaperones and allowed the recovery of pure PPO. Coexpression of PPO and GroELS resulted in a sixfold increase of soluble PPO yield, suggesting that bacterial chaperones could be limiting during the folding of the heterologous protein. However, a portion of PPO was still found in the insoluble fraction. Buffer containing the GroEL and DnaK enabled resuspension of PPO from the insoluble fraction but failed to enhance refolding of the denaturated protein. Attempts to increase the amount of soluble PPO using a thioredoxin-PPO fusion protein were not successful. Initial characterization of the recombinant PPO found that it possessed a high V(max), an elevated affinity for substrate, and an elevated sensitivity to PPO inhibitor herbicides compared to previous reports.

A randomised, open-label comparison of three highly active antiretroviral therapy regimens including two nucleoside analogues and indinavir for previously untreated HIV-1 infection: the OzCombo1 study

BACKGROUND

Highly active antiretroviral therapy (HAART) including two nucleoside analogues and a potent protease inhibitor is standard of care initial therapy for HIV-infected adults. The best-tolerated and most potent initial HAART regimen is unknown and was investigated in this study.

METHODS

One hundred and nine HIV-infected adults with no prior antiretroviral therapy, and CD4 lymphocyte counts < 500 x 10(6) cells/l or plasma HIV RNA > 30,000 copies/ml were randomized to zidovudine-lamivudine-indinavir (ZDV-3TC-IDV), stavudine-lamivudine-indinavir (d4T-3TC-IDV) or stavudine-didanosine-indinavir (d4T-ddI-IDV) for 52 weeks. The primary endpoints were plasma HIV RNA and drug-related adverse events. Other assessments were overall safety, adherence and adverse events, CD4 lymphocyte counts, cutaneous delayed type hypersensitivity (DTH) responses and quality of life (Euroqol).

RESULTS

Only 58% patients had HIV RNA < 50 copies/ml plasma at 12 months, with no significant difference between the three regimes (P = 0.34). Drug-related adverse events sufficiently severe to warrant drug discontinuation were less common (P = 0.06) in patients receiving d4T-3TC-IDV (18%) than in those receiving ZDV-3TC-IDV (34%) or d4T-ddI-IDV (41%). The percentages of patients who remained on their assigned therapy with plasma HIV RNA < 50 copies/ml at 52 weeks were 60% with d4T-3TC-IDV, 53% with ZDV-3TC-IDV and 35% with d4T-ddI-IDV. Virological failure at 52 weeks was more likely in those whose adherence was estimated to be < 100% in the first 4 weeks of therapy (P = 0.02), but not in those who developed grade 3 or 4 drug-related adverse events. At 52 weeks, the mean CD4 lymphocyte count increase was 200 x 10(6) cells/l with only 7% of patients having counts lower than at baseline; DTH responses improved but remained clinically impaired in most patients. Quality of life improved significantly in all groups.

CONCLUSIONS

Initial HAART regimens including IDV failed to suppress plasma HIV RNA to < 50 copies/ml in > 40% patients after only 12 months of therapy although there was significant overall improvement immunologically and in quality of life. The type of dual nucleoside combination used was less important in predicting virological failure than was imperfect adherence early in therapy. Consideration should be given to modifying a HAART regimen relatively early in non-adherent patients.

Organizational characteristics and issues affecting the longevity of self-help groups for parents of children with special needs

In this article, the organizational characteristics and issues affecting the maintenance of nine self-help groups for parents of children with special needs are discussed. Qualitative data were collected through interviews with 20 parents and observation of six group meetings. For continued existence, groups must deal with the challenges of encouraging new leaders, attracting new members, obtaining funds or assistance to support their activities, and meeting the changing needs of members. Important organizational characteristics associated with longevity are committed and effective leadership, community connections that help provide needed funds or practical assistance, and the willingness of group members to change activities to meet changing needs. This information can be used by parents and service providers to plan new groups, recruit group members, and ensure the effective functioning of groups as they change over time.

A syndrome of lipoatrophy, lactic acidaemia and liver dysfunction associated with HIV nucleoside analogue therapy: contribution to protease inhibitor-related lipodystrophy syndrome

BACKGROUND

Lipodystrophy (LD; peripheral lipoatrophy, central adiposity) hyperlipidaemia and insulin resistance often complicate protease inhibitor-containing antiretroviral therapy. Lipoatrophy and abdominal distension were observed in protease inhibitor-naive nucleoside analogue reverse transcriptase inhibitor (NRTI) recipients with lactic acidaemia and hepatic impairment, which are known NRTI-induced mitochondrial toxicities.

DESIGN AND SETTING

Case-control study in a university-based outpatient clinic.

PATIENTS AND METHODS

The patients studied included 14 NRTI recipients with lipoatrophy, 32 antiretroviral-naive patients without LD, 28 NRTI recipients without LD, 44 combined NRTI-protease inhibitor recipients without LD, and 102 NRTI-protease inhibitor recipients with LD. Data was obtained on body composition (questionnaire, physical examination, dual-energy x-ray absorptiometry and abdominal computerized tomography), with biochemical, lipid and glycaemic parameters.

RESULTS

The NRTI-LD syndrome was characterized by recent onset fatigue and nausea, peripheral lipoatrophy (6 kg loss over 4 months), abdominal distension (ascites +/- hepatomegaly) and elevated lactate (4.6, 1.1, 1.2, 1.4 and 1.7 mmol/l, respectively; P< 0.0001) and liver enzymes. Cases without hepatic involvement also had lower body fat and greater lactate than unaffected controls. Metabolic disturbances and weight improved after cessation. The NRTI-LD syndrome differed from protease inhibitor-related LD syndrome by the presence of recent onset symptoms and weight loss, higher lactate and alanine aminotransferase, and lower albumin, cholesterol, triglycerides, glucose and insulin. In treated controls, current stavudine therapy, protease inhibitor duration, and lactic acidaemia were independently associated with both lipoatrophy and abdominal obesity; total NRTI duration was also associated with lipoatrophy, and lamivudine and protease inhibitor duration with buffalo hump.

CONCLUSIONS

A syndrome of lipoatrophy, constitutional illness, lactic acidaemia and hepatic dysfunction can complicate NRTI therapy. Both protease inhibitor and NRTI therapies, particularly if associated with lactic acidaemia, contribute to LD syndrome, but have some distinguishable clinical and metabolic effects.

Validity and community utility of the Canadian Occupational Performance Measure

This study addressed the validity and community utility of the Canadian Occupational Performance Measure (COPM) (Law et al., 1991; 1994; 1998): a measure that now represents a national standard in clinical practice and research in occupational therapy in Canada. The study employed a crossectional design. Participants for the study were former consumers of occupational therapy services, recruited from the Queen's University catchment area (Kingston, North Bay, Oshawa, Perth, Peterborough). A sample of 61 disabled individuals living in the community were recruited. Each individual was sent a package of self-administered measures including the Satisfaction with Performance Scaled Questionnaire, the Reintegration to Normal Living Index, the Life Satisfaction Questionnaire, and the Perceived Problems List. An interview was also arranged with the project coordinator, which was based on the COPM and the Consumer Utility Questionnaire. Multivariate analyses showed that construct validity was supported; scores on the COPM were significantly related to theoretically related constructs: satisfaction with performance, reintegration to normal living and life satisfaction. In addition, criterion validity was supported. A majority of participants (53%), when asked about problems of daily living, spontaneously reported at least one of the problems raised on the COPM. Community utility was evaluated highly by participants, 75% of whom found the COPM useful in identifying and rating their problems, and 100% of whom reported no problems in understanding the COPM.

Salt, blood pressure and cardiovascular diseases

The rise in average blood pressure with age seen in Western populations does not occur in isolated traditional nomadic communities. Several factors contribute to the higher blood pressure in the West. Salt is particularly important, however, because its effect on blood pressure is large, the dietary intake by Western populations is high and a large reduction in its intake is realistic. The size of the relationship between salt and blood pressure depends on age and, in trials, the duration of reduction of intake of salt. Results of many of the randomized trials have suggested that reduction of dietary salt exerts only a small effect on average blood pressure; this is because their subjects have been young (average age 26 years) and trials have been of short duration (average 2 weeks). Analysis of observational data concerning various communities indicated that a reduction in dietary intake of sodium of 100 mmol/24 h (3 g of salt, a realistic reduction) lowers systolic blood pressure in subjects aged 50-65 years by 10 mmHg on average. Much evidence corroborates this estimate, including data from the Intersalt study and a randomized controlled trial of reduction of intake of salt by older persons. This reduction in blood pressure would reduce age-specific stroke mortality by an estimated 22% and mortality from heart disease by 16%. Reducing the amount of salt added to manufactured foods is an important public-health target.

Impact of early HIV-1 RNA and T-lymphocyte dynamics during primary HIV-1 infection on the subsequent course of HIV-1 RNA levels and CD4+ T-lymphocyte counts in the first year of HIV-1 infection. Sydney Primary HIV Infection Study Group

Plasma HIV-1 RNA and CD4+ T-cell counts after HIV-1 seroconversion are important independent markers that predict the clinical course of HIV-1 infection. The prognostic significance of these parameters during primary HIV-1 infection, however, remains largely unknown. In a cohort of 53 male study subjects (age, 33 +/- 7 years), who consecutively presented with primary HIV-1 infection, we analyzed the relationship between early plasma HIV-1 RNA, CD4+ and CD8+ T-cell counts, beta2-microglobulin, and p24-antigen levels determined in the first 3 months and subsequent plasma HIV-1 RNA levels and CD4+ T-cell counts 6 to 12 months after onset of primary symptoms. Peak, nadir, and median HIV-1 RNA levels in the first 30 days were already significantly associated with HIV-1 RNA levels at 6 to 12 months (p = .02, p < .0001, and p = .01, respectively). Similarly, early nadir and median CD4+ T-lymphocyte counts in the first 30 days showed a significant relationship with CD4+ T-cell counts at 6 to 12 months (p = .009 and p = .0008, respectively). Study subjects with an early decline of CD4+ counts to <500 cells/microl had an eightfold higher risk that CD4+ counts were <500 cells/microl at 1 year. Of all evaluated virologic parameters, only nadir HIV-1 RNA at 76 days predicted CD4+ counts at 6 to 12 months (p = .006). Early HIV-1 RNA levels and CD4+ counts are already associated with the time course of those parameters 6 to 12 months after onset of symptoms. Nadir viral load was the strongest predictor of HIV-1 RNA levels as well as of CD4+ counts at 6 to 12 months. An early decline of CD4+ T lymphocytes may be a useful clinical prognostic marker for rapid disease progression.

Vinblastine pharmacokinetics in patients with non-small cell lung cancer given cisplatin

The pharmacokinetics of vinblastine were studied in 16 patients with non-small cell lung cancer after a bolus intravenous dose of 3 mg/m2 given before or after cisplatin (100 mg/m2). Venous blood was collected at 0, 10, and 36 hr for analysis by radioimmunoassay. The mean plasma vinblastine concentration at 10 hr was similar when vinblastine was given before (4.8 ng/ml; 95% CI, 3.2-6.3) or after cisplatin (4.9 ng/ml; 95% CI, 2.7-7.1). Plasma vinblastine concentrations in patients given cisplatin were higher than previously reported in patients given vinblastine alone. Patients with plasma vinblastine concentrations less than 2.75 ng/ml at 10 hr experienced less severe neutropenia (37% fall in neutrophil count; 95% CI, 18-55) than those with levels greater than 2.75 ng/ml (69% fall in neutrophil count; 95% CI, 62-77). In conclusion, the pharmacokinetics of vinblastine predict the severity of neutropenia and may be altered when given in conjunction with cisplatin.

Health-related quality of life in childhood epilepsy: the results of children's participation in identifying the components

Separate groups of children with epilepsy, recruited from a regional pediatric epilepsy database, and their parents were established to discuss their life with epilepsy. Twenty-nine children (aged between 6 years and 10 years 4 months) and 42 of their parents were placed into nine and 17 groups respectively. The participants provided information about their own perceptions of life with epilepsy. Discussions were taped and textual analysis followed to extract, understand, explain, and categorize the health-related quality of life (HRQL) components. The process enabled us to identify the burdens and concerns of children with epilepsy, and to identify five emerging dimensions: (1) the experience of epilepsy, (2) life fulfillment and time use, (3) social issues, (4) impact of epilepsy, and (5) attribution. Identifying and understanding the components of HRQL is crucial for developing an HRQL scale in childhood epilepsy. In addition, this list of elements can help health professionals improve their services by considering and addressing aspects of the epilepsy experience beyond the traditional issues for children with epilepsy and their families.

A universal virus inactivant for decontaminating blood and biopharmaceutical products

Removal of virus infectivity from blood and biopharmaceutical products prepared from blood is an issue of considerable importance. Irrespective of the methods that are chosen it is vital that the biological activity of the product is not impaired. For blood and unfractionated plasma or serum, the problem is even more challenging. Selective inactivation of the genome is the key step in the preparation of killed virus vaccines. Imines have been used for more than 30 years for the preparation of inactivated foot-and-mouth disease virus vaccines without any evidence of survival of virus infectivity. Moreover, the immunogenicity of the virus is unimpaired. Viruses belonging to all the recognised families can be inactivated by imines. The biological properties of several proteins, including the cell growth-promoting factors in calf serum, are not impaired using conditions which ensure the inactivation of > 10(15) infectious units of poliovirus and foot-and-mouth disease virus (FMDV). Moreover, both viruses can be inactivated by imines at 4 degrees C, thus providing a method for removing infectivity from protein preparations which are unstable at higher temperatures. The mechanism by which FMDV is inactivated has been studied. We found that the RNA extracted from the virus after inactivation at 4 degrees C was not degraded and contained no hidden breaks but nevertheless was non-infectious. However, it could be amplified by PCR using primers corresponding to the gene coding for a portion of the viral RNA polymerase, but not from that coding for VP1, one of the structural proteins, showing that alteration of a base or bases had occurred in that region.

Application of the Person-Environment-Occupation Model: a practical tool

Occupational therapy focuses on complex dynamic relationships between people, occupations and environments. Therapists must clearly communicate their practices and how their practice influences outcomes. This paper explores applications of the Person-Environment-Occupation Model (Law et al., 1996) in occupational therapy practice, and delineates how this particular model helps therapists to conceptualize, plan, communicate and evaluate occupational performance interventions. Three case studies illustrate how the model can be used by occupational therapists to systematically approach analysis of occupational performance issues while considering the complexities of human functioning and experience. The ways in which the model facilitates communication within and outside occupational therapy are explained. The Person-Environment-Occupation Model is offered as a tool for therapists to use in client(s)-therapist alliances to enable clients to successfully engage in meaningful occupations in chosen environments.

Measuring outcomes in children's rehabilitation: a decision protocol

OBJECTIVE

To develop and test the feasibility and clinical utility of a computerized self-directed software program designed to enable service providers in children's rehabilitation to make decisions about the most appropriate outcome measures to use in client and program evaluation.

DESIGN

A before-and-after design was used to test the feasibility and initial impact of the decision-making outcome software in improving knowledge and use of clinical outcome measures.

SETTING

A children's rehabilitation center in a city of 50,000.

PARTICIPANTS

All service providers in the children's rehabilitation center. Disciplines represented included early childhood education, occupational therapy, physical therapy, speech and language pathology, audiology, social work, and psychology.

INTERVENTION

Using a conceptual framework based on the International Classification of Impairment, Disability, and Handicap (ICIDH), an outcome measurement decision-making protocol was developed. The decision-making protocol was computerized in an educational software program with an attached database of critically appraised measures. Participants learned about outcome measures through the program and selected outcome measures that met their specifications. The computer software was tested for feasibility in the children's rehabilitation center for 6 months.

OUTCOME MEASURES

Knowledge and use of clinical outcome measures were determined before and after the feasibility testing using a survey of all service providers currently at the centre and audits of 30 randomly selected rehabilitation records (at pretest, posttest, and follow-up).

RESULTS

Service providers indicated that the outcomes software was easy to follow and believed that the use of the ICIDH framework helped them in making decisions about selecting outcome measures. Results of the survey indicated that there were significant changes in the service providers' level of comfort with selecting measures and knowing what measures were available. Use of outcome measures as identified through the audit did not change.

CONCLUSIONS

The "All About Outcomes" software is clinically useful. Further research should evaluate whether using the software affects the use of outcome measures in clinical practice.