Effects of doxazosin and atenolol on circulating endothelin-1 and von Willebrand factor in hypertensive middle-aged men.

Elevated levels of endothelin-1 (ET-1) and von Willebrand factor (vWF), both markers indicative of endothelial function, are associated with hypertension. In a randomized open study we investigated the effect of antihypertensive treatment with the alpha-blocker doxazosin (n = 23) or the beta-blocker atenolol (n = 22) for 22 weeks on circulating levels of ET-1 and vWF in middle-aged men with essential hypertension. Blood pressure reduction was satisfactorily achieved with both drugs, although the decrease in the atenolol group was larger than that in the doxazosin group. A reduction in the levels of vWF occurred in both groups, being more pronounced in the alpha-blocker group compared with the decrease on beta blockers, p = 0.004 and p = 0.056, respectively. In the alpha-blocker group, there was a significant correlation (r = 0.50, p = 0.022) between the reduction in diastolic blood pressure and the decline in vWF. A highly significant decrease in plasma ET-1 was obtained during beta blockade (p = 0.007), whereas no significant change occurred within the alpha-blocker group. There was, however, no correlation between the decrease in blood pressure and the reduction in ET-1. The different favorable effects of alpha and beta blockers on endothelial function expressed as vWF and ET-1, could indicate that the effects are probably related not only to the blood pressure per se, but also to the different pharmacologic mechanisms of the drugs.     

Acyclovir treatment of relapsing-remitting multiple sclerosis

Acyclovir treatment was used in a randomized, double-blind, placebo-controlled clinical trial with parallel groups to test the hypothesis that herpes virus infections are involved in the pathogenesis of multiple sclerosis (MS). Sixty patients with the relapsing-remitting form of MS were randomized to either oral treatment with 800 mg acyclovir or placebo tablets three times daily for 2 years. The clinical effect was investigated by an extensive test battery consisting of neurological examinations, neuro-ophthalmological and neuropsychological tests, and evoked potentials. Results were based on intent-to-treat data and the primary outcome measure was the exacerbation rate. In the acyclovir group (n = 30), 62 exacerbations were recorded during the treatment period, yielding an annual exacerbation rate of 1.03. The placebo group (n = 30) had 94 exacerbations and an annual exacerbation rate of 1.57. Thus, 34% fewer exacerbations were encountered during acyclovir treatment. This difference in exacerbation rate between the treatment groups was not significant (P = 0.083). However, this trend to a lower disease activity in acyclovir-treated patients was supported in subsequent data analysis. If the patients were grouped according to exacerbation frequencies, i.e. into low (0–2), medium (3–5) and high (6–8) rate groups, the difference between acyclovir and placebo treatment was significant (P = 0.017). Moreover, in a subgroup of the population with a duration of the disease of at least 2 years providing an exacerbation rate base-line before entry, individual differences in exacerbation rates were compared between the 2-year pre-study period and the study period in acyclovir-treated (n = 19) and placebo (n = 20) patients and acyclovir-treated patients showed a significant reduction of exacerbations (P = 0.024). Otherwise, neurological parameters were essentially unaffected by acyclovir treatment and there were no convincing signs of reduced neurological deterioration in the acyclovir group. This study indicates that acyclovir treatment might inhibit the triggering of MS exacerbations and thus suggests that acyclovir-susceptible viruses might be involved in the pathogenesis of MS. This possibility warrants further investigation.     

AZATHIOPRINE INDUCED BONE MARROW SUPPRESSION IN LIVE RELATED RENAL ALLOGRAFT RECIPIENTS

Over a follow-up period of 6 years, 4 out of 31 live related renal allograft recipients (12.9%) developed azathioprine induced bone marrow suppression. Presentation in 3 patients was with fever and 2 patients also had associated graft dysfunction. All patients had leucopenia, 2 patients in addition had anaemia and one patient had pancytopenia. Bone marrow suppression developed 9.6 months (3.5-16.0 months) following transplantation and recovery followed over a period of 30 (18-49 days) days after withdrawal of the drug. One patient succumbed during the phase of bicytopenia.KEY WORDS: Azathioprine, Bone marrow suppression, Kidney transplantation     

Fibromuscular dysplasia of the internal carotid arteries

Seven patients with fibromuscular dysplasia of the internal carotid arteries have been operated upon at Walter Reed Army Medical Center. One lesion was treated by graduated dilatation with Bake's dilators combined with resection, end-to-end anastomosis, and vein patching of a tortuous segment. All other lesions were treated by graduated dilatation with an arterial dilator-shunt. All of these patients are asymptomatic presently. One patient has been operated upon recently because of symptoms related to the previously unoperated side as well as mild symptoms related to the previous operation. Two other patients with arteriographic evidence of fibromuscular dysplasia are being followed clinically. One is asymptomatic and one has minimal symptoms. Both are being treated with acetylsalicylic acid in hopes of preventing microembolization from these lesions. Important technical considerations in treating this condition are meticulous dissection of the internal carotid artery as near to the base of the skull as possible, confining the arteriotomy to the region of the carotid bulb, and straightening the carotid artery while passing the dilator under direct vision. A technique for routine shunting in these patients now is available.     

Characterization of and drug influence on a calmodulinsensitive phosphodiesterase purified from bovine brain

A calmodulin-sensitive phosphodiesterase was purified from bovine brain. The purification procedure involved ammonium sulphate fractionation, two chromatographic steps on DEAE-cellulose, gel-filtration on Sephadex G-200, and finally one DEAE-cellulose run, and gave a 2300-fold purification. The purified phosphodiesterase had a Vmax for cyclic AMP of 126 mumol/mg protein X min. and was activated 8-fold by addition of calmodulin and calcium. According to SDS-electrophoresis the purified enzyme contained one major peptide of 59,000 daltons, but the preparation was not homogeneous. The enzyme was characterized kinetically and with regard to the effect of cations, pH temperature, and nucleotides. Furthermore, the influence in vitro on enzyme activity of several classes of drugs, e.g. antidepressants, neuroleptics, antiallergics, platelet inhibitors, and some "reference phosphodiesterase inhibitors" was investigated.     

Transfusion-associated graft-versus-graft and potential graft-versus-host disease in a renal allotransplanted patient.

Transfusion-associated graft-versus-host disease (GVHD) is a rare but often fatal condition. We report on a case in which a 54-year-old man with polycystic kidneys shortly after receiving a male cadaver donor kidney developed severe intractable rejection and symptoms of GVHD. In situ hybridization with a Y chromosome- "specific" DNA probe and combined in situ hybridization and immunohistochemistry with monoclonal antibodies defining cellular phenotypes were performed on biopsy and tissue specimens taken at rejection episodes and from the lost allograft. The vast majority of infiltrating leukocytes in the morphologically rejecting kidney parenchyma were of female origin and consisted mainly of T lymphocytes and macrophages. This could only be explained by engraftment of leukocytes received in connection with transfusion of female whole blood in association with the transplantation. The patient developed symptoms of GVHD, and graftectomy was performed due to life-threatening cytomegalovirus infection. This case of combined "graft"-versus-graft disease and GVHD indicates that precautions in the administration of blood transfusion to severely immunosuppressed patients should be taken. We recommend the use of gamma-irradiated and lymphocyte-depleted blood products.     

Magnetic resonance imaging of renal calculi: an in vitro study

Extracorporeal shock wave lithotripsy (ESWL) has been established as a standard method of urinary stone treatment. Poor fragmentation with an increased rate of complications has been noticed with certain calculi types (calcium oxalate monohydrate and cystine). In devising appropriate pre-operative strategies, it would be useful to know the calculi composition. We have investigated the in vitro utility of using magnetic resonance imaging (MRI) in analyzing urinary calculi. Our in vitro analysis found no difference in signal characteristics between calculi of varying composition. The absence of signal can be understood from a molecular basis. We conclude that MRI will not offer any assistance in characterizing the composition of urinary calculi.     

Bilateral hallux saltans. Report of a case

A case of bilateral hallux saltans in a 13-year-old girl is reported. The signs and symptoms were a tender nodule behind the medial malleolus and a "trigger toe" as well as pain radiating up the lower leg. Operation revealed thickening of the flexor retinaculum superficially to the flexor hallucis longus tendon which showed compression and proximal thickening. Resection of the retinaculum afforded a satisfactory result.