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Biomedical subjects

R McMaster

Publications and source records attributed to R McMaster.

At least 19 recordsLinked to original sources
PubMed2000

Rural and remote mental health placements for nursing students.

Clinical placements can be instrumental in encouraging nursing students to consider a future career in rural Australia. Twenty nursing students from a metropolitan university were provided with the opportunity to undertake a clinical placement in mental health in a rural or remote setting. The majority of placements were between 2 and 4 weeks in length. They took place in community health centres and rehabilitation centres in New South Wales and in hospital inpatient facilities, remote areas and community health services in the Northern Territory. On return from the placement, students completed an open-question pro forma giving their views and impressions of their experiences and contrasting this with clinical experience gained in urban settings. The content of the students' responses was analysed and presented under the following themes: scale relating to urban and rural differences in population; geographical and health facility size; staffing matters; the environment; the students' perception of the clients; and professional interaction. Additional material relating to remote area placements is presented. Questions are raised about the maintenance of students' interest and the development of rural careers.

Australia↗
PubMed1996

Effective immunization of mice against cutaneous leishmaniasis using an intrinsically adjuvanted synthetic lipopeptide vaccine.

Two peptides representing predicted T-cell epitopes of gp63, a major surface glycoprotein of the parasite Leishmania major, were used in vaccines tested in a murine model of cutaneous leishmaniasis. Either subcutaneous or intraperitoneal immunization in saline with a peptide representing gp63 amino acids 467-482 (p467) significantly protected CBA mice against the development of severe cutaneous lesions only when the peptide was intrinsically adjuvanted by covalently adding a lauryl-cysteine moiety (LC-p467) to its amino terminus during synthesis. In marked contrast, administration of p467 alone, cysteinyl-p467 or gp63 protein in saline resulted in some disease exacerbation. Splenic cells of LC-p467 immunized mice stimulated in vitro with LC-p467 displayed strong proliferative responses and secretion of IL-2, IFN-tau and GM-CSF (but not IL-4 and IL-10) suggesting that immunization with the lipopeptide induced the TH1 type cytokine responses associated with cell-mediated immunity. The safety, efficacy, ease of production and standardization of such lipopeptide vaccines suggest that they have significant potential for the development of vaccines for humans against leishmaniasis or other parasitic or viral diseases that require cell-mediated immunity for protection.

Adjuvants, Immunologic↗
PubMed1995

Selection and implementation of a laboratory computer system.

The process of selection of a pathology computer system has become increasingly complex as there are an increasing number of facilities that must be provided and stringent performance requirements under heavy computing loads from both human users and machine inputs. Furthermore, the continuing advances in software and hardware technology provide more options and innovative new ways of tackling problems. These factors taken together pose a difficult and complex set of decisions and choices for the system analyst and designer. The selection process followed by the Microbiology Department at Heidelberg Repatriation Hospital included examination of existing systems, development of a functional specification followed by a formal tender process. The successful tenderer was then selected using predefined evaluation criteria. The successful tenderer was a software development company that developed and supplied a system based on a distributed network using a SUN computer as the main processor. The software was written using Informix running on the UNIX operating system. This represents one of the first microbiology systems developed using a commercial relational database and fourth generation language. The advantages of this approach are discussed.

Clinical Laboratory Information Systems↗
PubMed1985

Factors influencing pregnancy rates following in vitro fertilization and embryo transfer.

In 831 patients having 1533 in vitro fertilization treatments, pregnancy rates were examined in relation to clinical and laboratory factors. Pregnancy rates were significantly affected by the month and year of treatment, the age of the patient, the type of ovarian stimulation, the use of human chorionic gonadotropin, the number of eggs collected, the number of eggs fertilized, the number of embryos developed, and the number of embryos transferred. The most important factors determining pregnancy rates were the number of oocytes collected and the number of embryos transferred. The low pregnancy rate when only one egg was collected raises the problem of how to predict and manage such a patient in a current or future treatment cycle.

Adult↗
PubMed1983

Evaluation of diagnostic ultrasound as a parameter of follicular development in an in vitro fertilization program.

The ultrasound results in 141 patients through 203 cycles stimulated with clomiphene citrate prior to oocyte collection and in vitro fertilization are analyzed. A wide range in the size and number of follicles was seen. Bivariate analysis of the size of the largest follicle, compared with the time of the spontaneous luteinizing hormone (LH) surge, has shown a highly significant correlation (r = 0.720; P less than 0.001) between these two variables, but the accuracy of prediction of the LH surge in a specific cycle, as expressed by the standard error of estimate, was 34.3 hours. As an isolated observation, ultrasound results are no better than the menstrual history in predicting the time of the LH surge in stimulated cycles. Multiparameter assessment of follicular development is required.

Chorionic Gonadotropin↗
PubMed1982

The outcome of artificial donor insemination compared to the husband's fertility status.

One thousand, three hundred and fifty-seven women were treated by artificial donor insemination (AID) using frozen semen at seven Australian centres. Eight hundred and forty-three of the husbands were azoospermic and five hundred and fifteen had pathological semen. The wives of azoospermic men had a significantly higher rate of success when the two groups were compared by life table analysis. It appears likely that the wives of oligospermic men who require AID are less fertile, and may be a contributory factor in the couple's subfertility.

Australia↗
PubMed1978

The effects on sexual response and mood after sterilization of women taking long-term oral contraception: results of a double-blind cross-over study.

Twenty women using oral contraception for a minimum of 2 years with no side effects volunteered to take part in this experiment which commenced after they had undergone laparoscopic sterilization. In a double-blind cross-over design, patients were administered either 1.0 mg ethynodiol diacetate + 0.1 mg mestranol ("Ovulen") each day for 21 days or an identical-looking placebo for the same number of days. The following month the alternative (cross-over) tablet was given. On days 12 and 25 of each cycle the women completed a modified form of Pitt's Depression Index and a short Sexual Response Score. The result indicated that the active pill ("Ovulen") was associated with a decreased sexual response, but with no increase in the depression index (relative to placebo). The significance of these findings is discussed in relation to previous work, the methodology of the study and hormone-behaviour experiments.

Adult↗
PubMed1978

In-vitro fertilization of preovulatory human eggs.

Preovulatory eggs were aspirated from the ovaries of women 36-38 h after hCG and incubated with washed sperm suspensions for 3 or 6 h; 5 out of 9 eggs were fertilized. Sperm penetration into the ooplasm and decondensation of the male chromatin was observed by 3 h, and an early pronucleate egg was found by 6 h, suggesting that human spermatozoa may become capacitated in vitro in 3-4 h.

Ectogenesis↗
PubMed1977

Immunosuppression of T lymphocyte function by fractionated serum from tumor-bearing mice.

Sera from mice with transplanted 3-methylcholantrene-induced tumors have been shown previously to inhibit the function of normal lymphoid cells. When chromatographed on Sephadex G-150, the fraction eluting with immunoglobulin has been shown to inhibit the proliferative response of normal spleen cells to concanavalin A and to inhibit the in vitro antibody response to a T-dependent antigen, but has a lesser effect on the antibody response to a T-independent antigen. This paper deals with studies on the mode of action of the serum factor. The immunoglobulin containing fraction of serum from tumor-bearing mice inhibited the in vitro generation of both allogeneic and syngeneic cytotoxic lymphocytes. Time course studies demonstrate that the serum fraction inhibits the generation of antibody-producing and cytotoxic lymphocytes if added during the first 2 days of a 5-day culture. Serum fractions added after day 2 had no effect on the in vitro response. The serum factor appears to inhibit the generation of specific T cell function during the proliferative stage of development but has no effect on the differentiation stage which leads to either antibody-producing cells or cytotoxic lymphocytes.

Animals↗
PubMed1977

Identity of a T-lymphocyte inhibitor with mouse immunoglobulin in the serum of tumour-bearing mice.

A component of the serum of tumour-bearing mice has been shown to be inhibitory to the immunological function of normal mouse T cells. This factor fractionates with monomeric immunoglobulin upon gel filtration. Studies were carried out utilizing goat antisera to the major immunoglobulin chains of mouse Ig (kappa, gamma, alpha and mu) mixed with the immunoglobulin-rich fraction of serum from normal mice and tumour bearers and passed through immunoadsorbent columns prepared with rabbit anti-goat immunoglobulin. Such studies showed that the inhibitory activity in tumour-bearing serum could be removed after treatment with anti-kappa, anti-gamma and anti-mu chain antisera but not by treatment with either anti-alpha chain or goat immunoglobulin. That the inhibitory activity of tumour-bearing immunoglobulin could be attributed to simple quantitative differences in the levels of IgM and IgG in the test samples was discounted by quantification of the amounts of immunoglobulins in normal and tumour-bearing sera.

Animals↗
PubMed1977

Immunosuppression of T lymphocyte function by fractionated serum from tumor-bearing mice.

Sera from mice with transplanted 3-methylcholantrene-induced tumors have been shown previously to inhibit the function of normal lymphoid cells. When chromatographed on Sephadex G-150, the fraction eluting with immunoglobulin has been shown to inhibit the proliferative response of normal spleen cells to concanavalin A and to inhibit the in vitro antibody response to a T-dependent antigen, but has a lesser effect on the antibody response to a T-independent antigen. This paper deals with studies on the mode of action of the serum factor. The immunoglobulin containing fraction of serum from tumor-bearing mice inhibited the in vitro generation of both allogeneic and syngeneic cytotoxic lymphocytes. Time course studies demonstrate that the serum fraction inhibits the generation of antibody-producing and cytotoxic lymphocytes if added during the first 2 days of a 5-day culture. Serum fractions added after day 2 had no effect on the in vitro response. The serum factor appears to inhibit the generation of specific T cell function during the proliferative stage of development but has no effect on the differentiation stage which leads to either antibody-producing cells or cytotoxic lymphocytes.

Chemical Precipitation↗
PubMed1976

Characterization of a T-lymphocyte inhibitor in the serum of tumour-bearing mice.

Sera from mice with large tumours from a variety of tissue types and sources have been shown to contain substances capable of suppressing the proliferative response of normal mouse lymphocytes to concanavalin A (Con A), bacterial endotoxin (LPS) and allogeneic cells. The present paper deals with studies on the nature of these inhibitory materials using mainly a methylcholanthrene-induced rhabdomyosarcoma in DBA/2J mice. It was found that a material responsible for inhibition of the Con A response eluted with immunoglobulins on Sephadex G-150 and eluted with monomeric immunoglobulin on Sephadex G-200. The component of tumour-bearer serum responsible for the suppression of the LPS response of normal lymphocytes eluted from Sephadex G-150 with the alpha and beta globulins and albumin (molecular weight less than 150,000). The immunoglobulin-containing serum fraction from tumour-bearing animals inhibited the mixed lymphocyte response, Con A response, and specific immune response to purified protein derivative (PPD) in allogeneic cell systems. It also inhibited the in vitro primary response of mouse cells to sheep red blood cells, and, to a lesser extent, the response to a T cell-independent antigen (DNP-dextran). The inhibitory activity continued to elute with monomeric IgG on Sephadex G-200 when columns were run in 1640 medium and adjusted to pH 2-5, indicating that an acid dissociable complex was not responsible for inhibitory activity. Inhibitor activity could be removed by absorption on immuno-adsorbents containing goat anti-mouse immuno-globulin, and could be recovered by acid elution from the absorbent. Inhibitor activity was not removed by immunoadsorption on columns prepared with antisera to chicken immunoglobulin.

Adsorption↗
PubMed1975

The catecholamine-containing tubero-infundibular system and the control of luteinizing hormone release in the rabbit.

As determined by fluorescence histochemistry, the distribution of catecholamine-containing neurons in the hypothalamus of the female rabbit is similar to that seen in the rat. The fluorescence appearance of the hypothalamus was not appreciably different from normal at 0.25, 1, 4 or 24 h after mating, but in animals in which the synthesis of catecholamines was inhibited by the administration of the tyrosine hydroxylase inhibitor, H44/68, the number of fluorescent neurons seen in the nucleus periventricularis arcuatus following copulation was markedly reduced. However, the concentrations of luteinizing hormone (LH) in serum and in the pituitary glands of mated and unmated animals treated with H44/68 were not significantly different from those found in the corresponding control animals. This, together with the fact that ovulation followed mating in drug-treated rabbits suggests that a normal level of catecholamines in the tubero-infundibular system is not essential for the secretion of the amount of LH necessary for ovulation.

Animals↗