Involvement of Victorian general practitioners in obstetric and postnatal care

OBJECTIVE

To assess the current nature and extent of general practice (obstetric) involvement and the effect of gender on the provision of maternity care in Victoria.

METHOD

A postal survey to a community derived sample of 1104 Victorian general practitioners (with oversampling of female GPs) in August 1994 with hierarchical data analysis techniques used to account for the clustered (divisional) nature of the sampling frame.

RESULTS

A 70% response rate was achieved (715 out of an eligible sample of 1022). Three hundred and sixty-two (45.6%) GPs were providing shared care, 127 (17.7%) intrapartum care and 656 (92%) were involved in seeing women for their routine 6 week postnatal checkup. Male and female GPs were equally qualified and as likely to be vocationally registered (90% vs 92%). Female GPs were less likely than male GPs (11% vs 25%) to be involved in intrapartum care (OR = 0.4, 95% CI = 0.3-.06). Female GPs were more likely than male GPs (50% vs 41%) to be involved in shared care (OR = 1.4, 95% CI = 1.01-2.0), and postnatal care (OR = 3.7, 95% CI = 2.5-5.4). Provincial city (population > 15,000) GPs were more likely to provide shared care than other GPs. Fifty-two per cent of GPs providing shared care held a Diploma of Obstetrics. After accounting for the gender differences associated with practice location, rural GPs were more likely to provide intrapartum care (OR = 10.6, 95% CI = 3.5-32.4).

CONCLUSION

General practitioners play an important role in all facets of maternity care. Female and male GPs differ in their type of obstetric practice. If GPs are to maintain an intrapartum role, prompt action is required to increase the number of GPs involved in intrapartum care. The training requirements for shared care should be reviewed and a more suitable postnatal care curriculum should be developed.

Transduction of CD34+ cells by a vesicular stomach virus protein G (VSV-G) pseudotyped HIV-1 vector. Stable gene expression in progeny cells, including dendritic cells

OBJECTIVE

To use HIV-1 vectors to mediate stable gene transfer into hematopoietic stem/progenitor cells.

STUDY DESIGN/METHODS

Purified human CD34+ cells were transduced with HIV-1 vectors pseudotyped with VSV-G and subjected to colony-forming assays and differentiation in liquid culture. Transduction was determined by DNA-polymerase chain reaction (PCR) for the transgene. GFP reporter gene expression and phenotypes of progeny cells were assessed by microscopy and flow cytometry.

RESULTS

The HIV-1 vector transduced CD34+ cells with high efficiency. Transduction did not interfere with CD34+ cells differentiation in vitro. Transduced genes are expressed in different subsets of progeny cells, including those with normal dendritic cells (DC) morphology and phenotypes (HLADR+/CD1a+/CD86+/CD14-).

CONCLUSIONS

We have demonstrated efficient transduction of hematopoietic progenitor cells by HIV-1 vectors. The transgenes are expressed in different subsets of progeny cells, which suggests stable integration. The generation of DCs stably expressing HIV antigens provides a new approach for vaccine development.

Effects of polyethyleneimine on endocytosis and lysosome stability

Polyethyleneimine (PEI) is shown to destabilize isolated rat liver lysosomes, as indicated by a decrease in the latency of their acid N-acetyl-beta-glucosaminidase. PEI also inhibited the generation of radiolabeled digestion products from 125I-labeled bovine serum albumin endocytosed by rat visceral yolk sac in vitro. However, PEI did not greatly inhibit the endocytic uptake of a nondigestible fluid-phase substrate, fluorescein isothiocyanate (FITC)-dextran. It is hypothesized that PEI inhibits the adsorptive endocytosis of 125I-labeled bovine serum albumin, and thus its subsequent intralysosomal digestion, by competing with and displacing the labeled protein from its binding sites on the visceral yolk sac cell surface. This hypothesis suggests a plausible explanation for the ability of PEI to act as an efficient vector for gene and oligonucleotide transfer into mammalian cells. PEI present in the culture medium is carried into cells by adsorptive endocytosis. Concentrated thus on the endosome membrane, it permeabilizes this membrane and so affords DNA conjugated to the PEI an otherwise unavailable mode of access into the cytoplasm.

Collagen shield delivery of tobramycin to the human eye

PURPOSE

The purpose of this study was to determine the ocular penetration of tobramycin into the anterior chamber of the human eye when delivered by a pre-soaked collagen shield.

METHODS

We conducted a prospective, randomized study of 32 patients undergoing cataract surgery. The subjects were divided into two groups. The first group received three preoperative drops of commercially available combination tobramycin-dexamethasone drops at 15 minute intervals. In the second group, a collagen shield soaked in the same medication was applied to the eye prior to surgery. At the beginning of surgery, the aqueous humor was extracted for analysis.

RESULTS

The samples from 11 patients could not be analyzed due to an insufficient aqueous sample. Of the remaining 21 patients, the mean aqueous concentration was 0.026 microgram/mL (range: 0.0-0.09) in the drops group and 0.024 microgram/mL (range: 0.04-0.8 microgram/mL) in the shield group. This difference was not statistically significant. The aqueous concentration in both groups did not approach the minimum inhibitory concentration (4 micrograms/mL) for common ocular pathogens. No adverse effects related to the use of collagen shields occurred.

CONCLUSIONS

Perioperative use of a pre-soaked collagen shield utilizing a commercially available preparation of tobramycin-dexamethasone combination drops appears safe. However, the use of this system to prevent endophthalmitis is not warranted based on the concentrations obtained from the aqueous humor.

Ocular lens NAD kinase: partial purification and metabolic implications

The ocular lens displays a significant amount of NADP(H) dependent metabolic traffic, but the origin of this cofactor has not been established. Size exclusion chromatography of bovine lens crude extract on a Sephacryl S300-HR column fitted with an eluate concentrator revealed two bands with NAD kinase activity, based on enzymatic cycling with signal amplification of the column fractions using a Cobas-Fara II centrifugal fast analyzer. Ve/Vo ratios from the chromatographic runs suggest that the relative molecular weight values lie within the ranges 8.91-3.98 x 10(5) and 2.04-1.26 x 10(5), respectively, for these two bands. An approximately 10-fold enhancement of enzyme activity over the crude fraction is realized from the chromatography step. Results point to NAD kinase as the source generator of this anchoring and linking cofactor for the oxidative stress and pentose phosphate enzyme systems, respectively.

Childhood tuberculosis: advances in immunopathogenesis, treatment and prevention

Tuberculosis in childhood is an important cause of mortality worldwide. The disease is difficult to diagnose and the underlying immune mechanisms are poorly understood. Advances in the application of molecular genetic tools, as illustrated by the recent completion of the genome sequence of Mycobacterium tuberculosis, provide opportunities for the development of improved diagnostic tools and vaccines for tuberculosis. It is important that research efforts in this area should include consideration of the unique problems and possibilities related to the control of tuberculosis in children.

The psychosocial health status of carers of persons with dementia: a comparison with the chronically ill

This project aimed to determine overall psychosocial health (measured using the psychosocial dimension of the Functional Limitations Profile) and factors which influence this in a group of carers of those with dementia and to compare their psychosocial health with that of older people attending general practitioners (GPs); arthritis support groups and a pain clinic (out-patients) and a group of community dwellers undergoing renal dialysis. The carer group showed a significant decrease in recreation and pastimes and social interactions compared to older GP attenders. The carers showed similar restrictions in social interactions and recreation to those with chronic arthritis, but the latter were more impaired in the domains of emotional behaviour and sleep and rest. The older people attending a pain clinic did not differ in the areas of alertness and social interactions compared to the carer group. The dialysis group demonstrated the greatest dysfunction overall. These results suggest that the psychosocial health of carers of those with dementia is impaired, the profile of which differs from those suffering with chronic diseases. Social and recreation activities appear most affected in the carers. Commensurate with studies exploring the health status of those suffering from diseases, the measurement of the psychosocial health status of carers should also be considered in the scope of assessment and intervention.

Effects of phenobarbital on stereoselective metabolism of ifosfamide in rats

Plasma and urinary levels of ifosfamide (IF) enantiomers and their metabolites 2-dechloroethylifosfamide, 3-dechloroethylifosfamide, 4-hydroxyifosfamide, and isophosphoramide mustard were determined for control and phenobarbital-treated male Sprague-Dawley rats by using pseudoracemates and GC/MS and stable-isotope dilution analytical methods. For the control rats, the mean AUC for (S)-IF in plasma was greater than that for (R)-IF (R/S AUC ratio, 0.78) and the mean half-life of 41.8 min for (S)-IF was slightly longer than that of 34.3 min for (R)-IF. Phenobarbital pretreatment significantly decreased the AUC values for (R)-IF and (S)-IF, to 21 and 30% of the control values, respectively, and shortened plasma half-lives for both enantiomers [half-life for (R)-IF, 19.8 min; half-life for (S)-IF, 19.4 min]. The urinary excretion values for (R)-IF and (S)-IF were decreased to 41 and 30% of the control values, respectively. The overall amounts of the metabolites in urine were concomitantly increased. Additionally, there were significant reversals in both the R/S AUC ratio and the urinary excretion of 3-dechloroethylifosfamide. Moreover, the enantioselectivity for the generation of 4-hydroxyifosfamide and isophosphoramide mustard disappeared after phenobarbital treatment. These results strongly suggested that the 4-hydroxylation and dechloroethylation of IF enantiomers were mediated by different P450 isozymes or the same isozyme with different stereochemical selectivities.

Postovulatory ageing of mouse oocytes in vivo and premature centromere separation and aneuploidy

Two paramount observations exist regarding aneuploidy in human oocytes: its association with maternal age and its more frequent occurrence during meiosis I. Numerous experimental studies have shown that fertilization of postovulatory aged oocytes is coupled with reproductive failure and cytogenetic aberrations in embryos. However, the basic cytogenetic defect(s) of aged oocytes that causes these abnormalities has not been adequately described. The objective of this study was to test the hypothesis that postovulatory oocyte ageing results in increased frequencies of premature centromere separation (PCS) in metaphase II (MII) oocytes and aneuploidy in zygotes. MII oocytes and one-cell zygotes were collected from superovulated mice at different times after ovulation and fertilization. Chromosomes were C-banded and analyzed for structural and numerical aberrations. The frequencies of PCS in oocytes significantly (p < 0.01) increased with time postovulation: 15 h (15 of 529, 2.8%), 20 h (82 of 627, 13.1%), and 25 h (118 of 502, 23.5%). In zygotes, the frequencies of hyperploidy significantly (p < 0.01) increased with time post-fertilization: 0-4 h (0 of 260), 4-8 h (5 of 212, 2.4%), and 8-12 h (8 of 262, 3.1%). These data support the hypothesis that postovulatory ageing results in elevated levels of PCS in oocytes and of aneuploidy in zygotes. The link between PCS and aneuploidy may be random segregation of sister chromatids during anaphase II.

Cognitive-behavioral treatment of school-refusing children: a controlled evaluation

OBJECTIVE

To evaluate the efficacy of a 4-week cognitive-behavioral treatment program for children who refuse to go to school.

METHOD

Thirty-four school-refusing children (aged 5 to 15 years) were randomly assigned to a cognitive-behavioral treatment condition or a waiting-list control condition. Treatment consisted of individual child cognitive-behavioral therapy plus parent/teacher training in child behavior management skills. Measures taken before and after treatment included school attendance, child self-report of emotional distress and coping, caregiver reports on emotional and behavioral problems, and clinician ratings of global functioning.

RESULTS

Relative to waiting-list controls, children who received cognitive-behavioral therapy exhibited a significant improvement in school attendance. These children also improved on self-reports of fear, anxiety, depression, and coping. Significant improvements also occurred in relation to caregiver reports and clinician ratings. Maintenance of therapeutic gains was demonstrated at a 3-month follow-up assessment.

CONCLUSIONS

Cognitive-behavioral treatment of school refusal was efficacious and acceptable. The relative contributions of child therapy and parent/teacher training require further study.

The relationship between objective life status and subjective life satisfaction with quality of life

A locally developed quality of life inventory was used to examine the relationship between objective life status and subjective satisfaction with quality of life in 8,550 participants from Hunan, China. The inventory included 112 items in 4 dimensions-physical health, psychological health, social functional status, and living conditions. Objective life status was the principal factor affecting subjective satisfaction, but discrepancies were found in some participants, especially when objective status was at the extremes of the distribution. Young, urban, or more educated participants with higher scores on objective status often had lower subjective satisfaction scores in spite of comparatively high objective status scores. Participants who ranked lower on objective status (old, rural, or less educated people) sometimes ranked higher in subjective satisfaction. Scores for subjective satisfaction always showed a normal distribution, whatever the objective satisfaction of the population. Divergence between individual objective status and subjective satisfaction was associated with hierarchy of life needs and the reference standards used for the comparison.

Engineering a change in metal-ion specificity of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis-- X-ray structure analysis of site-directed mutants

We have refined the X-ray structures of two site-directed mutants of the iron-dependent superoxide dismutase (SOD) from Mycobacterium tuberculosis. These mutations which affect residue 145 in the enzyme (H145Q and H145E) were designed to alter its metal-ion specificity. This residue is either Gln or His in homologous SOD enzymes and has previously been shown to play a role in active-site interactions since its side-chain helps to coordinate the metal ion via a solvent molecule which is thought to be a hydroxide ion. The mutations were based on the observation that in the closely homologous manganese dependent SOD from Mycobacterium leprae, the only significant difference from the M. tuberculosis SOD within 10 A of the metal-binding site is the substitution of Gln for His at position 145. Hence an H145Q mutant of the M. tuberculosis (TB) SOD was engineered to investigate this residue's role in metal ion dependence and an isosteric H145E mutant was also expressed. The X-ray structures of the H145Q and H145E mutants have been solved at resolutions of 4.0 A and 2.5 A, respectively, confirming that neither mutation has any gross effects on the conformation of the enzyme or the structure of the active site. The residue substitutions are accommodated in the enzyme's three-dimensional structure by small local conformational changes. Peroxide inhibition experiments and atomic absorption spectroscopy establish surprisingly the H145E mutant SOD has manganese bound to it whereas the H145Q mutant SOD retains iron as the active-site metal. This alteration in metal specificity may reflect on the preference of manganese ions for anionic ligands.

Molecular Approaches in Mycobacterium tuberculosisand Other Infections Caused by Mycobacterium Species

The genus Mycobacterium consists of a diverse group of organisms that are ubiquitous and are believed to be some of the oldest bacteria on earth. They may exist as free-living commensals inhabiting soil and water, but they are also potentially pathogenic to man and other animals, being transmitted by airborne or droplet spread. At least 25 species of mycobacteria have been associated with human disease. Robert Koch in 1882, identified the acid-fast bacterium (AFB), Mycobacterium tuberculosis as the causative agent of tuberculosis (TB). TB is an ancient disease that remains a significant global health problem With improved living standards and the introduction of chemotherapy in 195Os, the incidence of TB in most industrialized countries showed a progressive decline, with very little mortality by the mid 1980s. This pattern has changed over the last decade.

Genetic, common environment, and individual specific components of variance for bone mineral density in 10- to 26-year-old females: a twin study

Lean mass and areal bone mineral density at the lumbar spine, femoral neck, and total forearm were measured in 215 volunteer female twin pairs (122 monozygotic, 93 dizygotic), aged 10-26 years, using dual energy X-ray absorptiometry. The study was conducted in Melbourne from 1990 to 1994. Under the classic twin model, there was evidence for a genetic component of variation in bone mineral density, adjusted for age or for age and lean mass, at all sites. Adjusting for lean mass almost halved the genetic variances in the adolescent years of peak growth, during which genetic variances peaked. Genetic variances were reduced in the late teenage years and increased in early adulthood. The latter may reflect gene-environment interactions or covariation. Importantly, there was evidence for environmental effects shared by twins on lumbar spine and femoral neck bone mineral density, even when adjusted for lean mass as well as age. These were greatest during the late teenage years, abated over the years when pairs started to live apart, and appear to be independent of lean mass during adolescence but not in early adulthood. In summary, the genetic and environmental etiology of bone mineral density is more complex than previously thought.

Differential regulation by MK801 of immediate-early genes, brain-derived neurotrophic factor and trk receptor mRNA induced by a kindling after-discharge

Transient changes in immediate-early genes and neurotrophin expression produced by kindling stimulation may mediate secondary downstream events involved in kindling development. Recent experiments have demonstrated conclusively that both kindling progression and mossy fibre sprouting are significantly impaired by administration of the N-methyl-D-aspartate (NMDA) receptor antagonist MK801. To further examine the link between kindling, changes in gene expression and the NMDA receptor, we examined the effects of MK801 on neuronal induction of immediate-early genes, brain-derived neurotrophic factor (BDNF) and trk receptor mRNA expression produced by a single electrically induced hippocampal after-discharge in rats. The after-discharge produced a rapid (after 1 h) increase in Fos, Jun-B, c-Jun, Krox-24 mRNA and protein and Krox-20 protein in dentate granule neurons and a delayed, selective expression of Fos, Jun-D and Krox-24 in hilar interneurons. MK801 pretreatment produced a very strong inhibition of Fos, Jun-D and Krox-20 increases in dentate neurons but had a much smaller effect on Jun-B and c-Jun expression. MK801 did not inhibit Krox-24 expression in granule neurons or the delayed expression of Fos, Jun-D and Krox-24 in hilar interneurons. BDNF protein and trk B and trk C mRNA expression were also strongly induced in dentate granule cells 4 h following an after-discharge. MK801 abolished the increase in BDNF protein and trk B, but not trk C mRNA in granule cells at 4 h. These results demonstrate that MK801 differentially regulates the AD-increased expression of a group of genes previously identified as being likely candidates for an involvement in kindling. Because MK801 significantly retards the development of kindling and mossy fibre sprouting, it can be argued that those genes whose induction is not significantly attenuated by MK801 are unlikely to play an important role in the MK801-sensitive component of kindling and the changes in neural connectivity (mossy fibre sprouting) associated with kindling. Conversely, the role in kindling of those genes whose expression was significantly attenuated by MK801 (Fos, Jun-D, Krox-20, trkB and BDNF) requires further examination.

Changes in collagen phenotypes during progression and regression of cardiac hypertrophy

OBJECTIVE

Excessive deposition of collagen has been implied to be responsible for abnormal stiffness and altered cardiac function during hypertrophy and heart failure. In the present paper we studied the changes in collagen and their phenotypes during development of cardiac hypertrophy in spontaneously hypertensive rats (SHR) compared to age- and sex-matched Wistar Kyoto (WKY). We also studied the changes in collagen after regression of hypertrophy, with antihypertensive therapy with ACE inhibitors, captopril (C) and lisinopril (L).

METHOD

Collagen was extracted from the heart tissue by cyanogen bromide (CNBr) digestion. Collagen phenotypes were separated and quantified by SDS-polyacrylamide gel electrophoresis. The transcript levels(mRNA) of collagen phenotypes were determined by Northern analysis.

RESULTS

Our studies showed that the ventricular collagen and their phenotypes did not alter in SHR during the first 6 months of progression of hypertrophy when compared to WKY. After 40 weeks, however, in SHR there was an unexpected rise in collagen content and the distribution of collagen phenotype differs compared to WKY, especially during the chronic phase of hypertrophy (65 weeks of age). In WKY during the aging process there was a gradual increase in type III collagen, whereas in SHR it plateaus after 40 weeks of age. Treatment with antihypertensive drugs captopril and lisinopril showed a similar degree of reduction in blood pressure (P < 0.001), regressed hypertrophy (P < 0.001), and reduced collagen, whereas decrease in type I to III ratio was found with captopril only, but not with lisinopril. This decrease in type I to III ratio due to captopril treatment is primarily due to an increase in type III collagen (both protein and transcript level) in SHR.

CONCLUSION

Our data showed, for the first time, that during the chronic phase of hypertrophy in SHR there is a gradual reduction in type I to III ratio, primarily due to a lack of increase in type III collagen during chronic phase of hypertrophy. This suggests that quality of collagen is an important factor in determining the degree of cardiac stiffness. Our data also showed that not all ACE inhibitors have similar actions on collagen phenotype production. This suggests that perhaps the mechanism of action of ACE inhibitors on collagen are independent of its effect on angiotensin II formation.

Health promotion and older people: a qualitative study of general practitioners' views

OBJECTIVES

To explore general practitioners' (GPs') beliefs about health promotion for older people and attitudes towards educational strategies likely to improve practice in this area.

DESIGN AND SETTING

Four discussion groups, each lasting one and a half hours, completed in Melbourne, Australia in August and September 1995. Interviews were transcribed verbatim and analysed for major themes.

PARTICIPANTS

A convenience sample of 20 GPs took part; 11 university affiliates, four participant contacts and five GPs from telephone book listings.

RESULTS

GPs' perceptions of their health promotion practice varied from "integrated into all medical care", to "something separate from usual practice". Positive views of older people contrasted with ageist views, with a few GPs expressing a nihilistic approach to medical care of older people. Regardless of the GPs' attitudes, lack of time and reimbursement disincentives were perceived to limit preventive practice and the potential impact of health promotion interventions. GPs felt overwhelmed with their workloads, and initial reactions to the idea of any "new" program were negative. Reactions to educational strategies varied, with choice and relevance to ease of practice being important for GP participation.

CONCLUSIONS

GPs differ in their views of health promotion and in their approaches to its delivery for older people. Educational programs are often viewed negatively, but if they offer the opportunity to save time, increased participation may be more likely.

Brain-derived neurotrophic factor is reduced in Alzheimer's disease

Alzheimer's disease may be due to a deficiency in neurotrophin protein or receptor expression. Consistent with this hypothesis, a reduction in BDNF mRNA expression has been observed in human post-mortem Alzheimer's disease hippocampi. To further investigate this observation, we examined whether the alteration in BDNF expression also occurred at the protein level in human post-mortem Alzheimer's disease hippocampi and temporal cortices using immunohistochemical techniques. We observed a reduction in the intensity and number of BDNF-immunoreactive cell bodies within both the Alzheimer's disease hippocampus and temporal cortex when compared to normal tissue. These results support and extend previous findings that BDNF mRNA is reduced in the human Alzheimer's disease hippocampus and temporal cortex, and suggest that a loss of BDNF may contribute to the progressive atrophy of neurons in Alzheimer's disease.

Social interaction alters attraction to competitor's odour in the mouse Mus spretus Lataste

When animals defend territories that are large and structurally complex, scent marks alone are unlikely to be reliable signals of a resident's dominance and competitors should require initial proof through direct interaction. This was tested using freshly captured Mus spretus which occupy large non-overlapping ranges in grassland but are strongly attracted to substrate odours from unfamiliar competitors. Choice tests measured time spent investigating and chewing to gain access to paired nestboxes when the entrances were blocked with mesh. Experiment 1 established that mice of both sexes were more strongly attracted to their own odour than to a clean site. Experiment 2 examined choice between the subject's own odour and that of an unfamiliar same-sex competitor both before and after meeting the competitor in a neutral (clean) arena. Prior to interaction, males exerted much effort to gain access to both their own and their unfamiliar competitor's odour. Once relative dominance had been established through agonistic interaction, subordinates avoided their dominant competitor's odour in favour of their own while dominants continued to be attracted to both. There was little aggressive competition between unfamiliar females and relative status did not affect their attraction to a competitor's odour. Females tended to be more attracted to a competitor's odour than to their own prior to interaction but showed less attraction to a competitor's odour post-interaction. A third experiment showed that the odour of an unfamiliar male was more attractive than that from an unfamiliar female, especially to males. The consequences of these responses for maintaining spatial dispersion in this species are discussed.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour