Immunoglobulin and immune complex levels in Nigerians with acute lymphoblastic leukaemia

Twenty-five patients with acute lymphoblastic leukaemia (ALL) aged 10 months to 43 years and twenty-five age and sex matched healthy control subjects were investigated in this study. Serum immunoglobulins A, G and M levels were measured by single radial immunodiffusion method and immune complex levels estimated by polyethylene glycol precipitation technique. Significant increase in immune complexes and decrease in immunoglobulin G were observed in the patients. Although not statistically significant, the patients had a lower mean level of immunoglobulin A, and a higher mean immunoglobulin M concentration than the controls. Hypoimmunoglubulinaemia observed in this study may contribute to the aetiology of ALL or be an effect of the disease. Raised immune complexes could result from specific antibodies combining with tumour associated or microbial antigens. Immunoglobulin G levels showed a significant positive correlation with survival in the patients. The adverse effect of reduced immunoglobulin G on the prognosis of ALL is probably due to compromised immunity in the patients.     

Selectivity in capillary electrophoresis in the presence of micelles, chiral selectors and non-aqueous media

In addition to high efficiency, short analysis times and small sample volumes, a further attractive feature of capillary electrophoretic techniques is the possibility to achieve, high selectivities. Usually, selectivity control also allows improvement in the resolution. A simple way to enhance the selectivity of capillary electrophoretic separations is to add one or more surfactants above their critical micelle concentration, or in the case of chiral separations to add a chiral selector to the background electrolyte. Because of the dynamic structure of micelles, the aggregation of monomers and size of the micelles can be easily adjusted. This review describes the various type of surfactants used in micellar electrokinetic capillary chromatography, and the chiral selectors employed in enantiomeric separations by capillary electrophoresis. Factors affecting the selectivity are noted. A brief discussion is included of the selectivity enhancement obtainable in non-aqueous media.     

Expression of transforming growth factors beta-1, beta 2 and beta 3 in human bladder carcinomas

We previously detected elevated transforming growth factor beta-1 (TGF-beta1) serum levels in patients with invasive bladder carcinomas. In this study, we therefore investigated whether elevated serum levels correlate with enhanced TGF-beta expression in human bladder tumours. mRNA levels of TGF-beta1, -beta2 and -beta3 were reduced in bladder tumour tissue to 86%, 68% and 56%, respectively, of the levels in normal urothelium. On the other hand, TGF-beta1 protein levels were found to be higher in superficial tumours (Ta-T1) (mean level of 0.153 ng mg(-1)) and in invasive T2/T3 tumours (mean level of 0.104 ng mg(-1)) compared with normal urothelium (mean level of 0.065 ng mg(-1)). Invasive T4 tumours, however, contained only low amounts of TGF-beta1 (mean level of 0.02 ng mg(-1)). Neither in mean nor in individual patients were serum and tissue TGF-beta levels correlated with each other. Cell culture experiments on primary bladder cells revealed a 57% decrease in TGF-beta1 mRNA levels in tumour compared with normal epithelial cells. Tumour epithelial cells contained about two times higher levels of TGF-beta2 and TGF-beta3 mRNA than normal epithelial cells. Fibroblasts expressed about the same amount of TGF-beta1 or TGF-beta2 as epithelial cells. Yet, fibroblasts released only 19% and 13% of the amount secreted by tumour epithelial cells into the supernatant. TGF-beta3, on the other hand, was expressed by fibroblasts with higher levels than by epithelial cells. TGF-beta1 was the predominent isoform in bladder tissue and cells at protein as well as on mRNA levels indicating that TGFs-beta2 and -beta3 are of minor importance in bladder cancer. In summary, there is a lack of correlation between TGF-beta serum levels and TGF-beta expression in tumour tissue in bladder cancer.     

Effect of roasted soybeans and corn on performance and ruminal and blood metabolites of dairy calves

Respiratory sinus arrhythmia (RSA) has been used as a non-invasive estimate of vagal tone to determine whether the reduction in resting heart rate commonly seen when humans are exposed to increases in the ambient pressure is associated with changes in vagal autonomic control. Two sets of divers (n = 4) were examined during two simulated saturation dives, one to 46 atmospheres absolute (ATA) and another to 37 ATA. A significant reduction in resting heart rate was seen in both dives upon exposure to high pressure compared with controls at 1 ATA. The reduction in heart rate seen at increased pressure was consistent regardless of respiratory rate, indicating that moderate changes in respiratory rate do not affect heart rate under these conditions. No changes in the overall magnitude of RSA were observed over a range of respiratory rates during either dive compared with control values at 1 ATA. During both dives, RSA was significantly larger (P < 0.05) at low respiratory rates compared with higher rates for both 1 ATA controls and at high pressure. The presence of a hyperbaric bradycardia strongly suggests that vagal tone is altered during hyperbaric exposure; however, the lack of change in the magnitude of RSA at high pressure brings into question the viability of using RSA as an accurate indicator of vagal tone and this lack of correspondence deserves further investigation.     

Endoscopic treatment of recurrent tracheo-oesophageal fistulae: long-term results

Recurrent tracheo-oesophageal fistula (RTOF) occurs in 5%-15% of patients following oesophageal atresia repair. Re-thoracotomy is technically challenging and associated with significant morbidity, including a re-fistulation rate of 10%-22%. Endoscopic occlusion of the RTOF with tissue adhesives (fibrin glue, Histoacryl) is reported to be safe and highly effective. However, long-term results of such therapy are absent from the literature. A postal survey of 13 institutions reporting the use of such treatment regimes for RTOF in the literature between 1974 and 1995 was performed, and data collected concerning the long-term outcomes of their reported patients. Eleven institutions responded to the request for data, providing 22 patients (age range 1 month to 12 years) for review. All had undergone initially successful RTOF closure by endoscopic methods and had been followed up for a median of 107 months (range 3-264 months). There was no morbidity or mortality directly related to the procedure. Overall, only 55% of these endoscopically treated fistulas remained closed long-term. Fistula recurrence invariably occurred within 12 months of successful therapy (median 46 days, range 9-335). Most patients required multiple endoscopic procedures to achieve successful RTOF closure (median 2.0, range 1-4 attempts), although significantly fewer attempts were required with fibrin glue therapy. Surgical re-exploration remains the treatment of choice in the fit child. Endoscopic therapy offers a safe and elegant alternative to high-risk surgery in the sick child, although repeated treatments may be required for successful RTOF closure.