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Biomedical subjects

M Baum

Publications and source records attributed to M Baum.

At least 91 records · Page 5Linked to original sources
PubMed2000

Risky behaviour in Jamaican adolescent patients attending a sexually transmitted disease clinic.

The prevalence of sexually transmitted diseases (STD) and risky behaviour patterns were studied in 165 adolescents attending a STD clinic in Jamaica. A standardised structured questionnaire, clinical algorithms for STD and serological tests for HIV and syphilitic infection were applied. High prevalences of risky behaviour including young age at onset of sexual activity, especially in boys, (mean age 12.5 +/- 2.5 years); unprotected sexual intercourse (only 4% used condoms consistently); multiple sexual partners (mean 3.8 +/- 2.4 and 1.8 +/- 1.2 for boys and girls, respectively) were found. Marijuana, used by 60% of the boys, was an independent risk factor for dysuria (adjusted Odds Ratio (OR), 2.0; 95% CI, 1.6-3.4). Repeated episodes of STD (33%), coinfection with HIV (1.2%), syphilis (1.2%) and teenage pregnancy (13%) were prominent findings. Educational strategies which promote behaviour intervention at an early age, frequent and consistent use of condoms, abstinence or delayed onset of sexual activity are essential to reducing the HIV/AIDS and STD risk in adolescents in Jamaica.

Adolescent↗
PubMed1999

Increased concentrations of interleukin 1-beta in whole blood cultures supernatants after 12 weeks of moderate endurance exercise.

The aim of the study was to investigate whether a regular moderate endurance exercise programme influenced the in vitro cytokine synthesis by stimulated whole blood cultures. To this end, eight healthy subjects exercised moderately by running for 3-5 h a week over a period of 12 weeks, whilst seven other healthy subjects served as the control group. The intensity of the exercise was determined by lactic acid concentrations in the blood which were maintained between 1.8 and 2.5 mmol x l(-1). Over the period of training the running velocity producing the 4 mmol x l(-1) lactic acid threshold increased from 2.86 (SD 0.83) m x s(-1) to 3.06+/-0.79 m x s(-1) (P < or = 0.008). Blood samples were taken at rest before and after the training programme. The following blood parameters were determined: leucocyte count, differential leucocyte count, lymphocyte subpopulations [CD14 positive (+)/CD45+, CD4+/ CD25+, CD8+, CD16+/CD122+]. Whole blood cultures were stimulated with lipopolysaccarides [interleukin (IL)-1 beta and IL-6] and staphylococcal enterotoxin B [IL-2, soluble interleukin 2 receptor (sIL2-R) and interferon (IFN)-gamma]. Cytokine concentrations in the supernatants were measured using an enzyme-linked immunosorbent assay. The white blood cell count, differential leucocyte count, lymphocyte subset distribution and the expression of the CD25 and CD122 antigen on lymphocytes were unchanged by training. After the training programme the IL-1 beta production changed significantly [1496 (SD 264) pg ml(-1) before, compared to 2127 (SD 672) pg ml(-1) after training, P < or = 0.008]. In the control group these parameters remained unchanged. With respect to changes in the values in both groups the syntheses of IL-1 beta (P < or = 0.023) and IL-6 (P < or = 0.021) were significantly higher after regular training. The syntheses of IL-2, sIL-2 and INF-gamma were not significantly influenced. Regular endurance exercise influenced the in vitro production of monocyte derived cytokines, while the effect of exercise on the cytokines synthesized by T-cells appeared to be of lesser importance.

Adult↗
PubMed1999

Allelic variation at (TAA)n microsatellite loci in a world collection of chickpea (Cicer arietinum L.) germplasm.

A set of 12 randomly selected (TAA)n microsatellite loci of the cultivated chickpea (Cicer arietinum L.) were screened in a worldwide sample comprising 72 landraces, four improved cultivars and two wild species of the primary gene pool (C. reticulatum and C. echinosperum) to determine the level and pattern of polymorphism in these populations. A single fragment was amplified from all the accessions with each of 12 sequence-tagged microsatellite site markers, except for one locus where no fragment was obtained from either of the two wild species. There was a high degree of intraspecific polymorphism at these microsatellite loci, although isozymes, conventional RFLPs and RAPDs show very little or no polymorphism. Overall, the repeat number at a locus (excluding null alleles) ranged from 7 to 42. The average number of alleles per locus was 14.1 and the average genetic diversity was 0.86. Based on the estimates obtained, 11 out of the 12 frequency distributions of alleles at the loci tested can be considered to be non-normal. A significant positive correlation between the average number of repeats (size of the locus) and the amount of variation was observed, indicating that replication slippage may be the molecular mechanism involved in generation of variability at the loci. A comparison between the infinite allele and stepwise mutation models revealed that for 11 out of the 12 loci the number of alleles observed fell in between the values predicted by the two models. Phylogenetic analysis of microsatellite polymorphism in C. arietinum showed no relationship between accession and geographic origin, which is compatible with the recent expansion of this crop throughout the world.

Alleles↗
PubMed1999

Acute vision loss in children with autosomal recessive polycystic kidney disease.

Patients with autosomal recessive polycystic kidney disease (ARPKD) often present with renal insufficiency and hypertension. We present two children with ARPKD and end-stage renal disease who developed anterior ischemic optic neuropathy and vision loss. Anterior ischemic optic neuropathy occurs rarely in children and has never been reported in children with ARPKD or end-stage renal disease. Both of our patients were chronically hypotensive and anemic, which are known risk factors for ischemic optic neuropathy.

Anemia↗
PubMed1999

Effect of luminal angiotensin II receptor antagonists on proximal tubule transport.

The proximal tubule can endogenously synthesize and secrete luminal angiotensin II at a concentration approximately 100- to 1000-fold higher than that in the systemic circulation. We have recently shown that this endogenously produced and luminally secreted angiotensin II regulates proximal tubule volume reabsorption, which is a reflection of sodium transport within this segment. In this study, we use in vivo microperfusion of angiotensin II receptor antagonists into the lumen of the proximal tubule to examine the role of the luminal AT1 and AT2 receptor in the regulation of volume reabsorption. Systemically administered (intravenous) AT1 and AT2 receptor antagonists, acting through basolateral angiotensin II receptors, have previously been shown to inhibit proximal tubule transport. Luminal perfusion of 10(-6) mol/L Dup 753 (AT1 antagonist) and 10(-6) mol/L PD 123319 (AT2 antagonist) decreased proximal tubule volume reabsorption from 2.94 +/- 0.18 to 1.65 +/- 0.18 and 1.64 +/- 0.19 nL/mm x min, respectively, P < .01. Luminal perfusion of 10(-4) mol/L CGP 42112A, another AT2 antagonist, similarly decreased volume reabsorption to 1.32 +/- 0.36 nL/nm x min, P < .01. The inhibition of transport with AT1 and AT2 antagonist was additive, as luminal perfusion of 10(-6) mol/L Dup 753 plus 10(-6) mol/L 123319 resulted in a decrease in volume reabsorption to 0.41 +/- 0.31 nL/mm x min, P < .001 v control, P < .05 v Dup 753, and P < .01 v PD 123319. These results show that endogenously produced angiotensin II regulates proximal tubule volume transport via both luminal AT1 and AT2 receptors.

Angiotensin II↗
PubMed1999

The effect of anastrozole on the pharmacokinetics of tamoxifen in post-menopausal women with early breast cancer.

Thirty-four post-menopausal women with early breast cancer who had received 20 mg tamoxifen once daily as adjuvant therapy for at least 10 weeks participated in a randomized, double-blind, parallel-group, multicentre trial. The primary aim of the trial was to determine the effect of anastrozole upon tamoxifen pharmacokinetics, with secondary aims of assessing the tolerability of the two drugs in combination and whether or not tamoxifen had any effect upon the oestradiol suppression seen with anastrozole. Patients were randomized to receive either 1 mg anastrozole (16 patients) or matching placebo (18 patients) once daily on a double-blind basis for 28 days. No significant difference (P = 0.919) was observed in serum tamoxifen concentrations between the anastrozole and placebo groups during the trial. The serum concentration of oestradiol was significantly suppressed (P < 0.0001) in patients co-administered anastrozole compared with placebo in the presence of tamoxifen, confirming that anastrozole remained an effective suppressant of oestradiol in the presence of tamoxifen. The combination of tamoxifen and anastrozole was well tolerated, with very little difference in side-effects reported between anastrozole and placebo. In conclusion, the results of this study confirm that anastrozole does not affect the pharmacokinetics of tamoxifen when the two drugs are given in combination to post-menopausal women with early breast cancer. In addition, the oestradiol suppressant effects of anastrozole appear unaffected by tamoxifen.

Anastrozole↗
PubMed1999

'Should a mammographic screening programme carry the warning: screening can damage your health!'?

The balanced presentation afforded by convening a Citizens' Jury when considering a major question such as the introduction of a breast screening programme is advocated. This method would enable account to be taken of all the costs, both human and financial, to all those affected, both participating and organizing, as well as the benefits. Provision of such a democratic opportunity enables consideration to be given to a broad range of factors, by selection of an appropriate range of witnesses, with the advantage of involving the lay public in this decision-making process. Attendance by health correspondents, medical journalists and other media representatives enables publicization of a democracy in action whilst helping to inform the wider debate. Such an exercise could inform whether the NHS BSP should continue in its current form.

Adult↗
PubMed1999

Contrast-enhanced colour Doppler ultrasonography in suspected breast cancer recurrence.

BACKGROUND: Postoperative scarring and radiotherapy changes in the conservatively treated breast often mimic breast cancer recurrence, resulting in many unnecessary biopsies. Local breast cancer recurrence may be detected more accurately with contrast-enhanced colour Doppler imaging. METHODS: Fifty-eight women with suspected local breast cancer recurrence were evaluated prospectively by means of conventional and contrast-enhanced colour Doppler imaging before surgical biopsy. RESULTS: Sensitivity for the detection of breast cancer recurrence using contrast enhancement was 94 per cent (specificity 67 per cent). Contrast enhancement significantly increased overall diagnostic accuracy, from 80 to 90 per cent (P < 0. 04). CONCLUSION: Contrast-enhanced colour Doppler imaging is a highly accurate method for detecting local breast cancer recurrence. Its adoption may substantially reduce biopsy rates.

Adult↗
PubMed1999

On the scientific inference from clinical trials.

We have not been able to describe clearly how we generalize findings from a study to our own 'everyday patients'. This difficulty is not surprising, since generalization deals with how empirical observations are related to the growth of scientific knowledge, which is a major philosophical problem. An argument, sometimes used to discard evidence from a trial, is that the patient sample was too selected and therefore not 'representative' enough for the results to be meaningful for generalization. In this paper, we discuss issues of representativeness and generalizability. Other authors have shown that generalization cannot only depend on statistical inference. Then, how do randomized clinical trials contribute to the growth of knowledge? We discuss three aspects of the randomized clinical trial (Mant 1999), First, the trial is an empirical experiment set up to study the intervention on the question as specifically and as much in isolation from other -- biasing and confounding -- factors as possible (Rothman & Greenland 1998). Second, the trial is set up to challenge our prevailing hypotheses (or prejudices) and the trial is above all a help in error elimination (Popper 1992). Third, we need to learn to see new, unexpected and thought-provoking patterns in the data from a trial. Point one -- and partly point two -- refers to the paradigm of the controlled experiment in scientific method. How much a study contributes to our knowledge, with respect to points two and three, relates to its originality. In none of these respects is the representativeness of the patients, or the clinical situations, crucial for judging the study and its possible inferences. However, we also discuss that the biological domain of disease that was studied in a particular trial has to be taken into account. Thus, the inference drawn from a clinical study is not only a question of statistical generalization, but must include a jump from the world of experiences into the world of reason, assessment and theoretical judgement.

Biometry↗
PubMed1999

Langer's axillary arch in association with sentinel lymph node.

Langer's axillary arch is a relatively rare anatomical variation of latissimus dorsi muscle insertion. The clinical importance of this condition in axillary lymph node dissection (ALND) and lymphoedema as well as latissimus dorsi flap reconstruction has been described previously. Axillary vein obstruction in association with this condition has also been reported. We report two cases of Langer's axillary arch encountered during sentinel lymph node (SLN) biopsy which had some bearing on the procedure.

Journal Article↗