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Biomedical subjects

J Meadows

Publications and source records attributed to J Meadows.

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

Who chooses to have the HIV antibody test in the antenatal clinic?

With the increase in human immunodeficiency virus (HIV) seroprevalence amongst antenatal clinic attenders, and given that current medical opinion considers it desirable that a woman is aware of her serostatus, it has been recommended that the HIV test is offered to all women in the antenatal clinic and that its uptake is monitored. This paper reports on the uptake rate during the 12 months to February 1990 at a central London hospital, which was 17%, and the characteristics of the women who agreed to be tested for HIV. Using information collected by the midwife on an interactive computer during the 'booking' interview, it was found that women who were single and not in a stable relationship (p < 0.001) and those who described themselves as Mediterranean (p < 0.01) were more likely to accept the test. Caucasian women (p < 0.05) and married women (p < 0.05) were less likely to accept the test. Accepters did not differ from decliners in any other variable examined. Possible reasons for these differences are discussed.

AIDS Serodiagnosis↗
PubMed1993

HIV antibody testing in the antenatal clinic.

With the increase in human immunodeficiency virus (HIV) seroprevalence amongst women attending the antenatal clinic in the UK it is essential that women are adequately prepared to make an informed decision about being tested for HIV and to receive the result of such testing. This paper discusses the purpose of testing, the necessity of pre-test counselling, its content and the practical implications of providing it. Guidelines for the content of a pre-test counselling session are outlined with particular reference to issues pertinent to the pregnant woman: vertical transmission, the effect of pregnancy on disease progression, the effect of HIV on pregnancy, the prognosis for an infected child and so on.

AIDS Serodiagnosis↗
PubMed1993

HIV antibody testing in the antenatal clinic: the views of the consumers.

OBJECTIVE: to investigate the attitudes of parturient women to HIV antibody testing in the antenatal clinic. DESIGN; anonymous self completion questionnaire. SUBJECTS: 318 women attending antenatal clinic for their first booking appointment. SETTINGS: a central London hospital, UK. RESULTS: 58% of the women felt that testing should not be compulsory, 33% that it should. Sixty per cent felt that results of the test should be given as routine but 38% felt that they should only be given if requested. Fifty five per cent felt the HIV test was as important as all the other routine tests and 60% felt that they personally did not need to be tested. Only 44% wanted to speak to a midwife about the test, with 23% saying that they did not want to speak to anyone at all. The main reason given for accepting testing was concern about passing the virus on to the baby, which was also the main concern if the test was found positive. Few women (23%) felt that those identified as positive should be encouraged to terminate their pregnancy. CONCLUSIONS: policy decisions around HIV testing should take into account the diversity of the needs and wants of this multicultural and multiracial group of consumers.

AIDS Serodiagnosis↗
PubMed1993

"I plan to have the HIV test"--predictors of testing intention in women attending a London antenatal clinic.

In order to identify which factors predict a parturient womans intention to take up voluntary HIV testing in the antenatal clinic, 318 women were surveyed by anonymous self-completion questionnaire. The strongest predictors of intention to be tested were the perceived benefit of the test to the woman herself, her partner, and the midwife, perceived risk of HIV infection, younger age and being single and having a poor knowledge of the sexual routes of HIV transmission. Health education strategies should therefore concentrate on: (a) increasing the parturient woman's knowledge of HIV transmission which will increase accuracy of perception of risk; and (b) stressing the potential benefits of HIV testing to all antenatal attenders, particularly to those who are older and in long term relationships.

AIDS Serodiagnosis↗
PubMed1992

Testing for HIV in the antenatal clinic: the views of midwives.

Self administered questionnaires were given to 34 midwives, who regularly counsel parturient women about the HIV antibody test, to investigate their attitudes to the test being offered in the antenatal clinic. Most of the midwives felt that testing should not be compulsory and that the test should be offered to all pregnant women who ask for it, not only those in recognized risk groups. Most also felt that women should be told the results of the test and that it should not be the midwives aim to increase the number of women having the test. Most felt that all midwives should counsel about the test but would like health advisers, GPs and obstetricians to be involved also. They also felt that they did not have sufficient knowledge in some areas to counsel particularly with regard to the practical and psychological implications of being HIV positive. This has implications in terms of the provision of adequate pre-test counselling for all pregnant women as an improvement in counselling services requires an allocation of finances, e.g. for training of midwives, which may be seen as unnecessary in areas of low seroprevalence. Further discussion and debate of these issues is required.

AIDS Serodiagnosis↗
PubMed1990

Sulfonamide resistance gene for plant transformation.

The sulfonamide resistance gene from plasmid R46 encodes for a mutated dihydropteroate synthase insensitive to inhibition by sulfonamides. Its coding sequence was fused to the pea ribulose bisphosphate carboxylase/oxygenase transit peptide sequence. Incubation of isolated chloroplasts with the fusion protein synthesised in vitro, showed that the bacterial enzyme was transported to the chloroplast stroma and processed into a mature form. Expression of the gene fusion in transgenic plants resulted in a high level of resistance to sulfonamides. Direct selection of transformed shoots on leaf explants was efficient using sulfonamides as sole selective agents. Transformed shoots rooted normally on sulfonamides at concentrations toxic for untransformed ones. Sulfonamide resistance was transmitted to the progeny of transformed plants as a single Mendelian dominant character. These results demonstrate that this chimeric gene can be used as an efficient and versatile selectable marker for plant transformation.

Amino Acid Sequence↗
PubMed1990

Voluntary HIV testing in the antenatal clinic: differing uptake rates for individual counselling midwives.

This study looked at 12 midwives in the Riverside Health Authority who counselled parturient women about having the HIV antibody test. Results showed that the uptake rate of the test varied considerably across midwives (82% to 3%). Uptake rate varied, to some extent, by ethnic group of the midwife; Afro-Caribbeans having 36% uptake, others 11%. However, the wide variation within these groups suggests that ethnicity alone does not explain the difference in uptake rate. Factors which could be associated with uptake rate are the individual characteristics of both the midwife and of the antenatal clinic attender, such as age, ethnicity, knowledge of and attitudes to HIV and antibody testing, as well as the counselling approach of the individual midwife.

AIDS Serodiagnosis↗
PubMed1990

Cyclosporin-associated akinetic mutism and extrapyramidal syndrome after liver transplantation.

Three patients developed akinetic mutism on the third day after the introduction of intravenous cyclosporin A, given for immunosuppression after liver transplantation. One patient in addition developed a florid orofacial dyskinesia, which resolved completely, as did the akinetic mutism, after withdrawal of cyclosporin. In these patients the time course of the akinetic mutism and extrapyramidal syndrome, which developed in the absence of any other identifiable cause, suggests cyclosporin A was the precipitating factor. Subsequently, two of the patients showed signs of pseudobulbar palsy with abnormalities in the pons on MRI scanning, suggesting central pontine myelinolysis (CPM). None of the patients had experienced significant fluctuations in serum sodium or other risk factors for central pontine myelinolysis and the exact relationship to the earlier cyclosporin related mutism was not clear.

Adult↗
PubMed1989

The N-terminus and a 4,000-MW peptide from the midportion of the N-terminus of the atrial natriuretic factor prohormone each circulate in humans and increase in congestive heart failure.

Two peptides consisting of amino acids 1-30 and 31-67 of the N-terminus of the prohormone of atrial natriuretic factor (pro-ANF) that have vasodilatory and natriuretic properties were investigated to determine if they circulate in humans. Specific and sensitive radioimmunoassays were developed to amino acids 1-30, 31-67, and 99-126 of pro-ANF. Evaluation of human plasma that had been subjected to reverse-phase high-pressure liquid chromatography suggested that pro-ANFs 1-30 and 31-67 as well as ANF were distinct peaks in human plasma corresponding exactly to pure synthetic peaks of these peptides on high-pressure liquid chromatography. Molecular weight determination of the endogenous immunoreactive peptides measured in plasma by G-50 Sephadex gel permeation chromatography revealed that the pro-ANF 1-30 radioimmunoassay recognized a peptide of 10,000 MW, which is consistent with it measuring the whole N-terminus of pro-ANF (amino acids 1-98) but without ANF (C-terminus) attached to it. The pro-ANF 31-67 radioimmunoassay recognized mainly (more than 95%) a peptide of 3,900-4,000 MW, which corresponds closely with its actual molecular weight of 3,878. Our ANF radioimmunoassay recognizes a peptide in plasma of 3,000 MW with the known molecular weight of ANF being 3,081. The mean circulating concentrations of immunoreactive pro-ANF 1-98, pro-ANF 31-67, and ANF in 54 control subjects were 531 +/- 25, 371 +/- 18, and 22 +/- 1 fmol/ml (+/- SEM), respectively. Thirty patients with varying severity of congestive heart failure were also studied. The N-terminus, C-terminus, and pro-ANF 31-67 increased: twofold for New York Heart Association functional Class II, threefold to ninefold for Class III, and 10- to 20-fold for Class IV patients with congestive heart failure. Thus, the N-terminus and a 4,000-MW peptide from the midportion of the N-terminus of pro-ANF as well as ANF circulate normally and increased proportionately to the increasing severity of congestive heart failure. However, because the pro-ANF 31-67 radioimmunoassay was the only assay that discriminated between patients with Class I congestive heart failure and control subjects, this assay may be the most useful to accurately classify the severity of congestive heart failure.

Adult↗
PubMed1989

Factors influencing lethality of Bacillus thuringiensis kurstaki toxin for eggs and larvae of Trichostrongylus colubriformis (Nematoda).

A toxin from Bacillus thuringiensis kurstaki was lethal to eggs and first- and second-stage larvae of the ruminant nematode Trichostrongylus colubriformis. Sheathed and exsheathed third-stage larvae were also killed by the toxin. However, susceptibility of the ova to the toxin decreased after several hours of development. Heating at 65 C for 1 hr or freezing at 0 C for 3 mo did not affect stability of the toxin. Ovicidal activity of the toxin was not altered by treatment with 13 microbial or mammalian enzymes, but toxicity was reduced by the antibiotics streptomycin or penicillin G and the enzyme inhibitor L-1-tosylamide 2-phenylethylchloromethyl ketone. Cuprous, ferrous, and zinc chlorides also inhibited the ovicidal activity of the toxin. Increased osmolarity of the assay media or solubilization of the toxin from pH 3 to 11 had no effect on toxicity for eggs. The membrane agents sodium vanadate and 4,4'-diisothiocyano-2,2' disulfonic acid stilbene increased (9-fold) and decreased (333-fold) toxicity, respectively. N-acetylneuraminic acid was the only tested sugar that reduced the toxicity of B. t. kurstaki.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1988

Two new hormones: prohormone atrial natriuretic peptides 1-30 and 31-67 circulate in man.

Two peptides consisting of amino acids 1-30 and 31-67 of the N-terminal end of the prohormone of atrial natriuretic factor (pro ANF) which vasodilate aortas in vitro, lower blood pressure in vivo, and have natriuretic properties were found to circulate in 54 normal human volunteers. The mean circulating concentration of pro ANF 1-30 was 1861 +/- 87 pg/ml (SEM) while pro ANF 31-67 mean concentration was 1478 +/- 71 pg/ml versus a level of 67 +/- 3 pg/ml for atrial natriuretic factor (ANF). In chronic renal failure their mean concentrations increased to 40,484 +/- 6,929 pg/ml (SEM), 108,566 +/- 16,888 pg/ml, and 348 +/- 81 pg/ml for pro ANFs 1-30 and 31-67 and ANF respectively. Since pro ANF 1-30 and pro ANF 31-67 circulate in man and have physiologic effects they meet the criteria of two new hormones.

Adult↗
PubMed1987

Uric acid protects erythrocytes from ozone-induced changes.

Uric acid effectively reduced hemolysis and methemoglobin formation in bovine and swine erythrocytes bubbled with ozone in vitro. In bovine erythrocytes, formation of thiobarbituric acid-reactive material was inhibited by uric acid, but there was little immediate protection for the swine cells. Antioxidant protection was due to preferential degradation of the uric acid by ozone. These results provide evidence to support the hypothesis that in plasma, uric acid can provide antioxidant protection for erythrocytes.

Animals↗
PubMed1986

Uric acid protects membranes and linolenic acid from ozone-induced oxidation.

Aqueous preparations of linolenic acid, bovine serum albumin, and bovine erythrocyte membrane fragments were bubbled with ozone in the presence or absence of uric acid. Ozonation of the membrane fragments or the bovine serum albumin did not result in protein degradation. After 15 min of ozonation, the absorbance of the thiobarbituric acid-reactive material increased by 0.34 in the linolenic acid preparation and by 0.08 in the suspension of membrane fragments. In the presence of uric acid, these changes in absorbance were reduced to 0.14 for the fatty acid and to 0.01 for the membrane fragments. This result indicates that uric acid protects lipids from ozone-induced oxidation.

Animals↗