Impaired protective immunity and T helper 2 responses in alymphoplasia (aly) mutant mice infected with Trichinella spiralis

The alymphoplasia (aly) mutation of mice prevents the development of systemic lymph nodes and Peyer's patches. The mutant homozygotes (aly/aly) are partially deficient in both humoral and cell-mediated immune functions. In the present study, we show that adult worm expulsion was slightly delayed and that T helper 2 (Th2)-type responses were partially defective in aly/aly mice after infection with Trichinella spiralis. Male aly/aly and aly/+ mice (8-weeks old) were infected with 400 muscle larvae. There was no difference in worm recovery between the two groups on day 5. However, worm recovery in aly/aly mice was significantly higher than that in aly/+ mice on day 14. Mucosal mast cells increased in number and peaked 14 days after infection in aly/+ mice. aly/aly mice were deficient in their mucosal mast cell response through out the primary infection. To examine the existence of mast cell precursors, aly/aly mice were treated with recombinant interleukin-3 (rIL-3) before infection. The mast cell response was poorly induced in aly/aly mice treated with rIL-3. An immunoglobulin E (IgE) response was not detected in aly/aly mice during the course of infection. Serum IgG1 levels in aly/aly mice were significantly lower than that of aly/+. The serum IgG2a levels increased in both strains of mice. However, IgG2a production in aly/aly mice on day 14 was half as much as that in aly/+mice. Stimulation of splenic T cells in vitro with anti-CD3 monoclonal antibody (mAb) showed that spleen cells from aly/+ mice on day 5 produced more IL-4 than spleen cells from aly/aly mice. IL-4 production from aly/aly mice on day 14 was half that from aly/+ mice. Interferon-gamma (IFN-gamma) was produced in both aly/aly and aly/+ mice on day 14. Proliferation assay showed that T cells of aly/aly mice responded poorly when cultured with antigen-presenting cells. These results suggest that aly gene is needed for the induction of protective immunity and Th2 responses in mice infected with T. spiralis.     

Direct agglutination test with urine samples for the diagnosis of visceral leishmaniasis

A new direct agglutination test (DAT) for use with urine samples for the diagnosis of visceral leishmaniasis (VL) has been developed and compared with the conventional DAT with serum samples and our previously reported enzyme-linked immunosorbent assay (ELISA) with urine samples (urine ELISA). The new DAT, in which anti-human IgG was used as enhancing antibody, was tested with urine samples from 75 VL patients and 225 non-VL patients and healthy people. The sensitivity of the new DAT (90.7%), was almost the same as that of the conventional DAT (91.0%) and the urine ELISA (93.3%). The specificity of the new DAT (96.4%) was nearly identical with that of the urine ELISA (97.3%). A urine-based DAT has several advantages over the conventional DAT: sample collection is non-invasive and it can process larger numbers of samples with smaller amounts of antigen.     

Evaluation of hormone replacement therapy

Hormone Replacement Therapy (HRT), once considered as the gold standard of treatment of menopausal symptoms and osteoporosis, introduced about seventy years ago still continuing with lot of controversies. Menopause, a transitional period of women's life, is not an illness when oestrogen level falls leading to its consequences. Results of earlier observational studies showed beneficial effects of HRT including cardiovascular protection. But all recent randomized controlled trials have failed to prove these positive effects, rather increases the cardiovascular risk and breast cancer. Women's Health Initiative(WHI), one of the recent randomized controlled trials was stopped prematurely in 2002 due to unfavorable risk-benefit ratio. HRT is not the only way of treating the menopausal symptoms and other consequences of estrogen deficiency. There are suitable alternatives without bearing the risk of HRT. Vasomotor symptoms with hot flushes and sweating experienced by about 75 percent of menopausal women can be treated with alternatives like phyto-estrogens, selective estrogen receptor modulators (SERMs), clonidine, selective serotonin reuptake inhibitors, acupuncture, exercise, behavioral therapy etc. HRT is no longer considered as the first line of treatment of postmenopausal osteoporosis. It can be treated with alternatives like regular weight bearing exercise, balanced calcium rich diet, maintaining weight, avoidance of bone robbers, (like excess alcohol, caffeine, smoking), use of SERMs etc. Use of HRT should be individualized and rationalized considering its risks and benefits.     

Increasing trend of ciprofloxacin resistance amongst common bacterial isolates at Mymensingh Medical College and Hospital

Ciprofloxacin resistance among common bacterial pathogen comprising Esch.coli, Staph.aureus and Pseudomonas spp. isolated from different clinical samples of Mymensingh Medical College Hospital during the periods of September, 1999 to March, 2001 and September, 2001 to August, 2002 were recorded. Values of two periods were compared and increased rate of ciprofloxacin resistance were noted in every bacterial species, e.g. 32.0% in Esch.coli, 8.7% in Staph.aureus and 5.1% in Pseudomonas spp. It was suggested to be aware and careful regarding use of ciprofloxacin in clinical practice so as to limit emergence of bacterial strains resistance towards the drug.     

Rhythms, rhymes, and reasons--spectral oscillations in neural cardiovascular control

Cardiovascular neural regulation is an integrated response to a continuous interaction of inhibitory and excitatory stimuli. Neural control of the circulation appears to be coded simultaneously in different modalities as amplitude (strength of signal or tonic activity) and frequency (oscillatory or phasic activity). Changes in tonic activity appear to be accompanied by tightly linked modulations in oscillatory characteristics. This is true within a narrow range of physiologic conditions, and the relationship is eliminated in extreme cardiovascular pathophysiology. Nevertheless, the oscillatory patterns in cardiovascular neural control appear to be widespread so that low and high frequency oscillatory patterns are evident even in sympathetic traffic to skin (Cogliati et al., 2000). Thus, it is likely that there is a functional significance to these oscillations. Recent data from Nafz et al. (1999) suggest that the presence of LF oscillatory characteristics in renal perfusion may attenuate renin-angiotensin activation during renal hypotension. These findings may have direct relevance to poorer outcomes observed in heart failure patients in whom an absence of LF oscillatory power was observed in RR interval and sympathetic traffic (Van de Borne et al., 1997a).     

Comparison of efficacy between Tamsulosin and Finasteride on symptomatic Benign Prostatic Hyperplasia

This prospective study was done to compare the efficacy of Tamsulosin and Finasteride for the medical treatment of symptomatic Benign Prostatic Hyperplasia (BPH) at the surgery and urology outpatient department of Mymensingh Medical College Hospital during the period from January 2003 to December 2004. Closely matched 70 patients in the age range of 50-80 years presented with lower urinary tract symptoms and clinically diagnosed as BPH were selected in the present study. Among them, 36 patients (Group I) and 34 patients (Group II) were treated with Tamsulosin (0.4 mg once daily) and Finasteride (5 mg once daily) for a duration of 06 months respectively. The efficacy of two drugs was compared on the basis of IPSS and Qmax. The base-line parameters of both groups were statistically insignificant. A significant improvement of IPSS and Qmax was found after 06 months of treatment in both groups (P<0.001). A significant improvement of IPSS Qmax was found in both groups (p<0.001) during follow-up at 1st, 2nd, 4th and 6th month. It was also observed that Tamsulosin improved the IPSS and Qmax more quickly than Finasteride.     

Plasma homocysteine in obstructive sleep apnoea.

AIMS: Whether increased homocysteine is one mechanism linking obstructive sleep apnoea (OSA) to cardiovascular abnormalities is unclear. We hypothesised that plasma homocysteine would be higher in OSA patients than in control subjects, would increase further during sleep, and decrease after treatment with continuous positive airway pressure (CPAP). METHODS AND RESULTS: For study A, homocysteine was measured in 22 OSA patients and 20 controls first before sleep, then after 5 h of untreated OSA, and then in the morning after CPAP treatment. Homocysteine was similar in the OSA and control subjects at all three time points, and declined overnight in both groups (P=0.0017, P=0.036, respectively). To further assess this diurnal variation, we studied plasma homocysteine under a full-night protocol in 10 OSA patients and 12 controls (study B). Homocysteine was measured before sleep, in the morning after sleep, and at noon. Results in both OSA and control groups showed an overnight decline in homocysteine which was reversed by noon (repeated measures ANOVA: OSA, P=0.04; controls, P=0.02). Study C showed that disturbed sleep did not affect homocysteine levels in normal subjects. CONCLUSION: There is a significant diurnal variation in plasma homocysteine, so that homocysteine is lower in the morning after waking. Neither OSA nor disturbed sleep elicit acute or chronic changes in homocysteine.