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Biomedical subjects

W R Jones

Publications and source records attributed to W R Jones.

At least 37 records · Page 2Linked to original sources
PubMed1994

Vaccination for contraception.

Vaccination for birth control has several advantages over currently available methods of family planning and should prove an attractive addition to the contraceptive armamentarium both in developing countries and in a developed country such as Australia. Concerns have been voiced by consumer health advocates that vaccines, like other long acting contraceptive methods, may be abused by health authorities in developing countries and by their use in vulnerable groups such as aborigines in our own country. These concerns need to be recognised and addressed. More difficult to accommodate are the anxieties expressed by feminist groups about the 'loss of control' and 'lack of body awareness' inherent in a method, such as a vaccine, that is relatively easily administered and has no overt side effects. There is no evidence that these concerns are shared by women in general. The antifertility vaccine that will most likely be applied first in family planning programmes is one directed against the pregnancy hormone hCG. A WHO vaccine directed against the C-terminal peptide of beta-hCG provokes a specific and safe immune response and will enter Phase 2 trials in Sweden this year. Subsequent developments with this vaccine will include the replacement of the current emulsion vehicle by a delivery system based on biodegradeable microspheres which will give a more sustained antigen release and duration of effectiveness.

Antigens↗
PubMed1994

Single payer: do government-run programs meet America's needs?

The impact of a government-run program on our current health care system is not well understood by most Americans. Californians could be in for many unpleasant surprises should the single payer ballot initiative pass this November. The author examines how a single payer program attempts to meet the goals of health care reform and why it fails in many important aspects.

California↗
PubMed1993

Pregnancy complicated by the antiphospholipid syndrome.

A patient with previously undiagnosed antiphospholipid syndrome (APS) developed atypical severe preeclampsia at 31 weeks' gestation. Other complications of pregnancy included intrauterine growth retardation, thrombocytopenia and fetal distress necessitating urgent delivery of a live infant. There was a prior history of unexplained jugular venous thrombosis. Prophylaxis against thrombosis was commenced immediately postoperatively and no postpartum complications occurred. Recent evidence supports the use of antepartum prophylaxis with low dose heparin in patients with APS. The role of low dose aspirin, either alone or in combination with heparin, is yet to be determined. Human immunoglobulin may be useful in selected cases. Early diagnosis is a key factor in their management.

Adult↗
PubMed1993

Fixing the individual health insurance market.

The individual health insurance market is in crisis. Among the possible options for reform, a managed competition approach offers the broadest, most comprehensive solution.

Competitive Medical Plans↗
PubMed1992

New approach to the analysis of low levels of anions in water.

Optimized electromigrative sample introduction improves detection limits for anions in capillary electrophoresis. Reproducible results are achieved for micromolar and nanomolar levels of concentration. The new method offers shorter runtimes, improved resolution and greater simplicity in comparison with ion chromatography. The technique was applied to water samples from the power industry. Trace levels of anions are monitored routinely in water for steam generation in conventional and nuclear power plants. Reproducible and accurate results are presented for pure water samples containing typical concentrations of anions as well as for more specific types of samples, such as water compositions in the primary and secondary circuits of a nuclear power plant.

Anions↗
PubMed1992

Trends in causes and treatment of infertility at Flinders Medical Centre, Adelaide, 1976-1989.

OBJECTIVE: To describe the causes of infertility among couples presenting to a fertility clinic over a period of 14 years. Changes in treatment methods over the same period are described. DESIGN: A retrospective analysis of records of patient age, date of first visit, duration and cause of infertility, treatment and outcome. SETTING: A fertility clinic set in a large public hospital. Patients are referred by both general gynaecologists and general practitioners. PATIENTS: From 1976 to 1989 (inclusive) 2895 couples who had engaged in unprotected intercourse for at least 12 months without conceiving attended the clinic. RESULTS: Three major diagnostic categories were considered; these embraced aetiological factors relating to semen, ovulation, and pelvic anatomy. Investigation of the causes of infertility after a couple's first visit showed these to be a semen defect in 22%, irregular cycles or anovulation in 29%, and a pelvic disorder in 57%. The incidence of semen defects as the cause remained constant between 1976 and 1989 while that of ovulation "problems" declined from 42% in 1976 to 13% in 1989. In contrast, the incidence of pelvic dysfunction increased from 40% in 1976 to 68% in 1989, predominantly due to an increased diagnosis of endometriosis. The principal treatments were ovulation induction/cycle regulation (51%), in-vitro fertilisation/gamete intrafallopian transfer (42%), and donor insemination (18%). CONCLUSIONS: Provided patient information is accurately and consistently recorded a Fertility Audit is a useful window on the activates of a Fertility Clinic and serves to highlight areas which warrant further investigation.

Adult↗
PubMed1992

Contraception.

The principle of vaccination for the purposes of fertility regulation is scientifically elegant and socially compelling. Factors such as economic production, convenience of use, relatively long-lasting but reversible protection, low failure rate and the avoidance of mechanical devices or exogenous hormones make this approach a potentially attractive option for family planning programmes in both developing and developed countries. The major efforts in research and development have involved the prospect of active immunization against specific antigens of sperm, oocyte, zygote and early embryo, and the pregnancy hormone human chorionic gonadotrophin (hCG). Several anti-hCG vaccines have entered clinical trials. They operate by preventing or interrupting pregnancy at the peri-implantation stage probably by neutralizing the luteotrophic effect of hCG. The most refined vaccine is one directed against the unique C-terminal peptide on the beta-subunit of hCG. This vaccine provokes antibodies that are specific for hCG and do not cross-react with human luteinizing hormone (hLH). Preclinical studies in baboons and data from a phase I human trial indicate that this method is free of side-effects and provides the promise of a duration of effectiveness of up to 12 months. Future research will optimize the anti-hCG approach, utilize new vaccine delivery systems and broaden the spectrum of target antigens of potential utility for contraceptive vaccines.

Antigens↗
PubMed1992

Prediction of carcass characteristics by real-time ultrasound in barrows and gilts slaughtered at three weights.

The carcass characteristics of 27 market barrows and 27 market gilts were evaluated at various times (n = 8) with real-time ultrasound (Aloka 210 DX) from approximately 20 kg until slaughter at three end points. The pigs were randomly assigned to slaughter weight groups of 91, 104.5, and 118 kg at weaning time. Correlations were determined over slaughter weight group and sex, and the accuracies of ultrasound measurements were also evaluated. The regressions of ultrasound 10th-rib fat and ultrasound longissimus muscle area on live weight were also developed. Correlations between actual and ultrasound-measured last-rib fat, 10th-rib fat, and longissimus muscle area were high (r = .91, .63, and .53, respectively; P less than .01). The accuracy of ultrasound longissimus muscle area prediction was lower for 118-kg pigs than for the two lighter groups, whereas the accuracy for prediction of last-rib fat was lower for 91-kg pigs than for the two heavier groups, as indicated by higher absolute differences (P less than .05). Last-rib fat and longissimus muscle area tended to be overestimated and 10th-rib fat tended to be underestimated by real-time ultrasound. Prediction of last-rib fat by ultrasound was more accurate for gilts than for barrows, as indicated by a lower absolute difference (P less than .05).

Adipose Tissue↗
PubMed1991

Analysis of anion constituents of urine by inorganic capillary electrophoresis.

Inorganic capillary electrophoresis (ICE) is a new separations technology which melds the technique of classical electrophoresis with the separations approach of ion chromatography. Matrices which have been difficult to deal with using ion chromatography have proven amenable to analysis by ICE. The simultaneous analysis of weak acid anions, oxalate and citrate and inorganic anions, chloride, sulfate, nitrate, phosphate and carbonate in diluted urine was achieved using ICE. The determination of the oxyanions of arsenic (i.e. arsenite and arsenate) in urine was also performed.

Anions↗
PubMed1991

The preliminary clinical evaluation of the safety and efficacy of a fertility regulating vaccine.

Since the mid 1970s, the World Health Organization's Special Programme of Research, Development and Research Training in Human Reproduction, through its Task Force on Vaccines for Fertility Regulation, has been supporting and coordinating the development of a birth control vaccine based on a synthetic peptide representing part of the beta subunit of human chorionic gonadotrophin (beta-hCG). The majority of this work has been carried out in the laboratories of Dr V.C. Stevens at Ohio State University. This hCG vaccine has recently been tested for tolerability and immunogenicity in a phase I clinical trial, and a preliminary evaluation of the vaccine's efficacy in fertile women volunteers is currently being planned. This paper describes the preclinical and clinical testing of this vaccine and the problems and challenges presented by this novel preparation. These have included the need to carry out safety and efficacy studies in the baboon, and the difficulties of designing appropriate preclinical toxicity and immunosafety studies and clinical trial protocols in the absence of previous experience with vaccines of this type.

Animals↗
PubMed1991

A comparison of swim-down and swim-up methods for the extraction of high motility sperm.

High quality motile sperm are essential for the success of the in vitro fertilization-embryo transfer program and related procedures, for the performance of sperm antibody assays, and other in vitro tests of sperm function. Two methods for the extraction of high motility sperm, swim-down and swim-up, were compared on 30 ejaculates, and sperm motility was assessed at intervals up to 18 hours. The swim-down method was simpler, shorter, and provided a significantly better recovery of sperm with sustained high motility than did the swim-up method.

Analysis of Variance↗
PubMed1991

Allergy to coitus.

Acute systemic hypersensitivity reactions to semen are rare but may be life-threatening. Chronic or recurrent local reactions are more common and may be misdiagnosed as infective or nonspecific vaginitis. The antigen(s) involved in these reactions reside in a glycoprotein fraction of seminal plasma. Allergic vulvovaginitis may also occur in sensitized women when they are exposed to exogenous allergens such as drugs, food and infective agents during sexual activity. Skin testing and other relevant investigations are indicated when these disorders are suspected. Condom usage will prevent symptoms of coital allergy. Desensitization has had variable success in acute systemic hypersensitivity. Precoital antihistamines may modify local reactions.

Contraceptive Devices, Male↗
PubMed1991

Cognitive and social influences on smoking behaviour during pregnancy.

A random sample of 292 women attending a hospital antenatal clinic for routine care was surveyed concerning smoking behaviour and beliefs about smoking in pregnancy. Among women who continued to smoke during their pregnancy, most had cut down. Many expressed a desire to quit, felt guilty about not being able to do so, but reported that smoking offered important benefits relating to relaxation and mood control. Forty (27.8%) of the 144 women who were smokers at the time they became pregnant had quit during pregnancy. In a multivariate analysis, a nonsmoking household, and being more convinced about the health effects of maternal smoking, were most strongly associated with successful cessation. These 2 variables alone were able to correctly classify 83.8% of women as quitters or continuing smokers. Implications for health promotion programmes and messages are discussed.

Adult↗
PubMed1990

Isolation of fetal trophoblast cells from peripheral blood of pregnant women.

Fetal trophoblast cells were isolated from maternal peripheral blood by means of murine monoclonal antibodies of high specificity and affinity for human syncytiotrophoblast and nonvillous cytotrophoblast cells. The cells were isolated in sufficient numbers to allow polymerase chain reaction (PCR) amplification of the Y-chromosome-specific DNA sequence from the peripheral blood of thirteen pregnant women. The fetal sex predicted by PCR analysis of the isolated trophoblast cells accorded with that ascertained by karyotyping of chorionic villus samples in eleven of twelve women studied in early pregnancy and with the sex of the baby on delivery in one woman studied at 34 weeks' gestation. Isolation of these fetal cells could allow noninvasive diagnosis of a wide range of inherited disorders.

Antibodies, Monoclonal↗
PubMed1990

Correlation of umbilical cord whole blood viscosity and the presence of fetal distress at birth: a mathematical modelling study.

This study was designed to investigate the relationship between umbilical cord blood viscosity and clinical parameters such as maternal parity, maternal smoking, mode of delivery, sex of infant and the incidence of fetal distress at birth using mathematical modelling. The results demonstrated vaginal delivery, male infants, infants of primigravidas and low cord whole blood viscosity at a high shear rate were covariables and were associated with an increased incidence of fetal distress and low Apgar scores.

Adult↗
PubMed1990

Altered growth-rate-dependent regulation of 6-phosphogluconate dehydrogenase level in hisT mutants of Salmonella typhimurium and Escherichia coli.

In Escherichia coli, the level of 6-phosphogluconate dehydrogenase is directly proportional to the cellular growth rate during growth in minimal media. This contrasts with the report by Winkler et al. (M. E. Winkler, J. R. Roth, and P. E. Hartman, J. Bacteriol. 133:830-843, 1978) that the level of the enzyme in Salmonella typhimurium LT-2 strain SB3436 is invariant. The basis for the difference in the growth-rate-dependent regulation between the two genera was investigated. Expression of gnd, which encodes 6-phosphogluconate dehydrogenase, was growth rate uninducible in strain SB3436, as reported previously, but it was 1.4-fold growth rate inducible in other S. typhimurium LT-2 strains, e.g., SA535. Both the SB3436 and SA535 gnd genes were growth rate inducible in E. coli K-12. Moreover, the nucleotide sequences of the regulatory regions of the two S. typhimurium genes were identical. We concluded that a mutation unlinked to gnd is responsible for the altered growth rate inducibility of 6-phosphogluconate dehydrogenase in strain SB3436. Transductional analysis showed that the altered regulation is due to the presence of a mutation in hisT, the gene for the tRNA modification enzyme pseudouridine synthetase I. A complementation test showed that the regulatory defect conferred by the hisT mutation was recessive. In E. coli, hisT mutations reduced the extent of growth rate induction by the same factor as in S. typhimurium. The altered regulation conferred by hisT mutations was not simply due to their general effect of reducing the polypeptide chain elongation rate, because miaA mutants, which lack another tRNA modification and have a similarity reduced chain growth rate, had higher rather than lower 6-phosphogluconate dehydrogenase levels. Studies with genetic fusions suggested that hisT mutations lower the gnd mRNA level. The data also indicated that hisT is involved in translational control of gnd expression, but not the aspect mediated by the internal complementary sequence.

Cloning, Molecular↗
PubMed1988

Phase I clinical trial of a World Health Organisation birth control vaccine.

A birth control vaccine incorporating a synthetic peptide antigen representing the aminoacid sequence 109-145 of the C-terminal region of the beta subunit of human chorionic gonadotropin (hCG-beta) was submitted to a phase 1 clinical trial. Thirty surgically sterilised female volunteers, divided into five equal groups for different vaccine doses, received two intramuscular injections six weeks apart. Over a six-month follow-up there were no important adverse reactions, and potentially contraceptive levels of antibodies to hCG developed in all subjects. In the highest vaccine dose group, the results gave promise of a contraceptive effect of six months' duration.

Adult↗