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Biomedical subjects

R Jones

Publications and source records attributed to R Jones.

At least 829 records · Page 46Linked to original sources
PubMed1985

Vascular endothelial cells in cell-mediated immunity: adoptive transfer with in vitro conditioned cells is genetically restricted at the endothelial cell barrier.

Delayed-type hypersensitivity (DTH) is a cell-mediated immune response that can be adoptively transferred in rats when greater than 2 X 10(8) cells from peritoneal exudate, lymph nodes, or spleen are used. We have shown that by using an in vitro conditioning step with antigen, transfer can be subsequently carried out with as few as 2 X 10(7) spleen cells. The magnitude of DTH was reflected in ear swelling after intradermal injection of antigen [tuberculin or keyhole limpet hemocyanin (KLH)] and confirmed histologically. The transfer was antigen specific, requiring the sensitizing antigen in both the in vitro conditioning step and in the ear test challenge. Adoptive transfer with conditioned cells was genetically restricted by alleles of the RT-1 region [major histocompatibility complex (MHC) of the rat]. Brown Norway strain (n haplotype) immune cells would not transfer DTH to Lewis (1 haplotype), ACI (a haplotype), or Buffalo (b haplotype) rats, whereas each strain would transfer DTH to syngeneic recipients. Moreover, this pattern of restriction held for all strains when tested in reciprocal fashion. In additional experiments, F1 to parental bone marrow chimeras were constructed so that bone-marrow-derived cells and non-bone-marrow-derived cells were of different RT-1 haplotypes. When these chimeras were used as recipients, transfer of DTH was only observed when immune donor cells and recipient non-bone-marrow-derived cells were syngeneic. These results point to the critical role of non-bone-marrow-derived cells (endothelial cells) in the DTH reaction.

Animals↗
PubMed1985

Effects of transdermal scopolamine upon psychological test performance at sea.

The effects of transdermal scopolamine upon objective psychological performance assessments and self reports of feeling states, were investigated with volunteer subjects at sea. Scopolamine and placebo patches were administered on consecutive days in a counterbalanced order. Psychological performance was assessed 24 h following each transdermal patch. Choice reaction time and code substitution performance levels were not significantly changed, but letter cancellation errors were significantly more frequent following transdermal scopolamine. Transdermal scopolamine caused significantly more reports of dry mouth. More subjects were also unable to undertake the performance tests following scopolamine than placebo, due to difficulties in focusing on the test materials. However despite deleterious side effects with some personnel, others responded positively to the scopolamine patch. As noted by other workers, responses to the transdermal scopolamine patch seem to be quite variable.

Adolescent↗
PubMed1985

Development of a maturation antigen on the plasma membrane of rat spermatozoa in the epididymis and its fate during fertilization.

The ontogeny of a surface membrane antigen on rat spermatozoa has been investigated using the monoclonal antibody, 2D6. Using indirect immunofluorescence microscopy the 2D6 antigen was first detected on spermatozoa from the proximal corpus epididymidis; no reaction was present on testicular cells. The 2D6 antibody also bound to spermatozoa flushed from the uterus of mated rats and to a sperm-derived antigen on the surface of newly fertilized eggs. When frozen sections of epididymal tissues were stained with 2D6 monoclonal antibody immunofluorescence was confined to the epithelium lining the duct in the proximal and distal corpus epididymidis. Fluorescence in the tissue was androgen-dependent. Immunoblots of proteins in luminal secretions collected by micropuncture from different sites along the epididymal duct showed that in the proximal corpus epididymidis the 2D6 monoclonal antibody recognized a 32 kD antigen, but in secretions from the distal corpus and cauda epididymidis the monoclonal antibody also recognized antigens with molecular weights of 28, 23 and 20 kD. Immunoblots of proteins from spermatozoa collected from the corpus epididymidis revealed a reaction over a 32 kD antigen, while on spermatozoa from the cauda epididymidis the 2D6 monoclonal antibody recognized only a 23 kD antigen. Two hypotheses are proposed to account for the varied reactivity of the monoclonal antibody and their relative merits are discussed.

Animals↗
PubMed1985

The use of derivative and least-squares methods to analyse a polypharmaceutical product by UV spectrophotometry.

Derivative UV spectrophotometry is well established for analysing pharmaceutical products containing more than one drug. By contrast, the least-squares method for over-determined systems is rarely used, because it is assumed that measurements at a large number of wavelengths are needed to obtain good results. Both methods have advantages, and their use in combination is useful for analysing polypharmaceuticals. A combination of derivative and least-squares methods was used to analyse tablets containing pseudoephedrine hydrochloride, triprolidine hydrochloride and dextromethorphan hydrobromide. Pseudoephedrine was determined by derivative spectrophotometry. The other drugs were determined by the least-squares method at higher wavelengths where pseudoephedrine does not absorb. Satisfactory precision for the least-squares method was obtained with a manual spectrometer measuring at six wavelengths and calculating the results with a microcomputer.

Journal Article↗
PubMed1985

A format for integrating the interpretation of exercise ejection fraction and wall motion and its application in identifying equivocal responses.

The conventional interpretation of ejection fraction change with exercise may be limited because it does not consider the rest value, define equivocal responses or integrate wall motion data reproducibly. Thus, a format was developed for combined interpretation of rest and exercise radionuclide ejection fraction and wall motion by reviewing the reported data for the exercise responses of patients without prior myocardial infarction. The ejection fraction data of 202 normal patients and of 259 patients with coronary artery disease were first fitted to beta distributions. The true positive and false positive rates for coronary disease for each combination of rest and exercise ejection fraction were then determined directly from these distributions. A given rest/exercise ejection fraction combination was "normal" if the false positive rate was greater than the true positive rate, or "abnormal" if the true positive rate was greater than the false positive rate, and "equivocal" when the rates were similar (within a 50% confidence interval). This analytic format, which predicted an inverse relation between rest ejection fraction and the change required with exercise, was then validated prospectively in 854 patients without myocardial infarction (557 with and 297 without angiographic coronary artery disease). Using the conventional criterion of an abnormal test result (less than 0.05 absolute rise in ejection fraction with exercise or a wall motion abnormality), sensitivity was 85 +/- 2% and specificity only 42 +/- 3%. The statistical format had a sensitivity of 70 +/- 2% and specificity of 70 +/- 3%, resulting in a twofold increase in information content. This format has at least two advantages over conventional interpretation: 1) it provides an explicit definition of equivocal responses; and 2) it reproducibly integrates discordant ejection fraction and wall motion responses and allows for the combined analysis of other nonscintigraphic observations, such as age and sex.

Adult↗
PubMed1985

Oxygen toxicity and restructuring of pulmonary arteries--a morphometric study. The response to 4 weeks' exposure to hyperoxia and return to breathing air.

This study describes the pulmonary vascular lesions in rat pulmonary arteries and altered right ventricular weight after 1) prolonged exposure to hyperoxia (87% O2 for 4 weeks) at ambient pressure, 2) weaning from hyperoxia to air over 7 days, and 3) return to breathing air for 2, 4, or 8 weeks. Hyperoxia for 28 days narrows the lumen of intraacinar and preacinar arteries, increasing the percent medial thickness (%MT) by reducing the external diameter and thickening medial muscle. The ratio of patent intraacinar arteries to alveoli is significantly reduced, and pulmonary vascular obstruction and obliteration is evident by electron microscopy. A higher proportion of intraacinar and preacinar arteries have muscle in their wall than in the normal lung: in alveolar wall and duct regions, the proportion of partially muscular and muscular intraacinar arteries increases at the expense of nonmuscular ones (for both regions P chi 2 less than or equal to 0.001); and in arteries associated with terminal bronchioli and bronchioli the proportion of muscular arteries increases at the expense of partially muscular ones (for both regions P chi 2 less than or equal to 0.001). Both after weaning and after return to breathing air lumen size increases; but, even after 8 weeks, the %MT remains significantly increased, and the ratio of intraacinar arteries to alveoli is less than normal. After weaning, the proportion of muscularized intraacinar and preacinar arteries is similar to that after hyperoxia. Two weeks after return to breathing air, the proportion of muscularized alveolar wall and duct arteries is greater (for both regions P chi 2 less than or equal to 0.001). Even 8 weeks after return to breathing air more arteries are muscularized than normal (for both alveolar wall and duct regions P chi 2 less than or equal to 0.001), and within the alveolar wall still more are muscularized than after hyperoxia (P chi 2 less than or equal to 0.001). Hyperoxia causes right ventricular hypertrophy, reducing the ratio of the weight of the left ventricle and septum to that of the right ventricle (P chi 2 less than or equal to 0.001). Weaning further increases the hypertrophy, the ratio being further reduced (P chi 2 less than or equal to 0.001, compared with both hyperoxia and control values). On return to breathing air the degree of hypertrophy is less, but it persists, and even after 8 weeks the ratio is still less than normal (P chi 2 less than or equal to 0.01).

Animals↗
PubMed1985

Relationship between cervical condylomata, pregnancy and subclinical papillomavirus infection.

From a retrospective study of 415 sets of colpophotographs, 25 clinically obvious condylomata of the cervix were identified. Two morphologically distinct forms were found and termed erythrocondylomata and leukocondylomata on the basis of their colposcopic appearance. Erythrocondylomata are red, raised lesions with diagnostic large capillary loops. Those lesions were found in young women (mean age, 22 years) and associated with pregnancy in 72% of cases. They were observed to involute and disappear to the naked eye within a few months of the diagnosis. Colposcopic and histologic studies, however, indicated that the lesions could persist in subclinical form. Of eight such lesions studied, five showed histologic and colposcopic features of subclinical papillomavirus infection, and two showed histologic features compatible with cervical intraepithelial neoplasia (CIN). Leukocondylomata are brilliant white lesions associated histologically with a thick layer of keratin over a typical condylomatous base. Those lesions occurred at a later age (mean, 32 years), were not associated with pregnancy and tended to increase rather than involute with time. Epidemiologic studies have indicated that it is the young and sexually active who are at most risk of developing cervical cancer. This study indicated that it is this same group that is also at highest risk of developing erythrocondylomata of the cervix. Such lesions have been shown to involve the squamocolumnar junction and transformation zone when that area is most active and vulnerable. The progression of such lesions to subclinical papillomavirus infection and CIN suggests that they may be involved in the initiation of the cervical neoplastic process.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Identification and management of the toxic adolescent.

Experimentation with alcohol and drugs is prevalent in adolescence. The clinical caring for older children, adolescents, and young adults must include substance misuse or abuse whenever behavioral, family, or related medical problems occur. A systematic approach using checklist and questionnaires, a directed physical examination, selected laboratory testing, and a 3-visit (or more) evaluation protocol will provide the clinician with the opportunity to assess patients and provide both them and their families with appropriate referrals. Most if not all clinicians seeing adolescents have these patients in their practices. Making the diagnosis is a result of recognition of symptoms and signs, evaluation, and appropriate referrals. The foregoing discussion should provide one approach to patient management that can result in the retrieval of a substantial number of our youth from an alcohol and drug-dominant lifestyle with its irreversible medical, social, and emotional residue.

Adolescent↗
PubMed1985

Patients' attitudes to chaperones.

In a survey of 200 female patients attending a five-man practice in a health centre, 75 per cent of the respondents stated that they would like to be offered a chaperone at pelvic examinations. Only six per cent would accept the offer if the examination was performed by their own doctor and 17 per cent if a different doctor examined them. Patients expressing a definite wish for a chaperone were significantly younger and were less likely to have had a previous pelvic examination. Those who definitely did not want one had usually had a pelvic examination before and had been registered with their doctor for significantly longer. These findings may have implications for the conduct of pelvic examination in young women by trainee and locum general practitioners.

Attitude↗
PubMed1984

Purification of non-histone acceptor proteins for ADP-ribose from mouse testis nuclei.

Acceptor proteins for poly(ADP-ribose) have been purified from mouse testis nuclei. Nuclear proteins were labelled in vitro with [14C]ribose and [3H]adenine, extracted with 5% (v/v) HClO4 and 0.25 M-HCl and separated by ion-exchange chromatography. Non-histone proteins were found to be the major acceptors in both the 5% (w/v)-HClO4-soluble and 5%-HClO4-insoluble HCl-extractable fractions. Of the two groups of non-histone proteins associated with chromatin, the LMG (low-mobility-group) proteins were preferentially ADP-ribosylated. HMG (high-mobility group) proteins were labelled to lower specific radioactivity. Six LMG proteins were purified to approx. 90% homogeneity and were identified from their mobility on polyacrylamide gels at pH 2.9 and from their amino acid composition. The average length of the poly(ADP-ribose) chain was estimated to be four to six repeating ADP-ribose units. It is suggested that ADP-ribosylation of LMG proteins, a long-neglected group of chromatin-associated proteins, is important during spermatogenesis for the production of spermatozoa with intact and competent DNA.

Adenosine Diphosphate Ribose↗
PubMed1984

Hyperosmotic oral replacement fluid for diarrheic calves.

Twenty-five diarrheic neonatal calves, none of which was recumbent, were used to determine oral efficacy of a commercial product for fluid replacement, either by suckle or intubation. Changes in plasma protein, glucose, sodium, potassium, and osmolality as well as blood lactate and PCV were measured. Core body temperature and surface temperature at the hock and fetlock were monitored. Data were analyzed for interaction with time and response according to clinical condition. Significant differences (P less than 0.05) following therapy were restricted to glucose and potassium changes. Beneficial posttreatment trends were observed in cutaneous temperature, blood lactate, plasma protein, and PCV values.

Animals↗
PubMed1984

Knowledge about and utilization of facilities for cervical smears among black women in Johannesburg.

Cancer of the cervix is the most common cause of death from carcinoma among Black South African women. Mortality from this disease can be reduced by screening using the cervical smear. To determine the knowledge about and utilization of facilities for cervical smears among Black women in Johannesburg, 89 women were interviewed at Baragwanath Hospital. Only 4 of these had heard of or had had a cervical smear. This indicates that education about cervical carcinoma and cervical smears needs to be more extensive.

Black or African American↗
PubMed1984

Intravenous calcium treatment of refractory hypotension in Reye's syndrome.

Hypotension refractory to volume infusion and sympathomimetic drugs developed in a child with Reye's syndrome who had received prochlorperazine prior to admission. Calcium chloride given intravenously restored autonomic tone, resulting in restoration of a normal BP and cerebral perfusion pressure. Calcium may reverse the hypotensive effects of prochlorperazine maleate and may help reverse hypotension in patients with Reye's syndrome who have been pretreated with phenothiazine antiemetics.

Calcium Chloride↗