Spontaneous regression of optic pathways gliomas in three patients with neurofibromatosis type I and critical review of the literature

Case reports The authors report their experience about three children (two girls, one boy; average age 1.6 years) with a spontaneous regression of optic gliomas. All of them had a previous diagnosis of neurofibromatosis type 1 (NF 1). None of them underwent surgery or biopsy nor received chemotherapy or radiotherapy. The complete regression was documented by MRI scans performed during a mean follow-up of 6.3 years.Literature review Moreover, the authors analyze the features of the 16 cases previously reported in English literature of spontaneously regressed optic gliomas with an overview of the different therapeutic strategies. The knowledge that this kind of tumor, particularly in young patients, may regress is important in the decision of the best therapeutic approach.     

Dual blockade of the renin-angiotensin system in type 1 patients with diabetic nephropathy.

BACKGROUND: Albuminuria and hypertension are predictors of poor renal and cardiovascular outcome in patients with diabetes. Approximately 30% of type 1 patients with diabetic nephropathy (DN) have albuminuria >1 g/day, and blood pressure >135 and/or >85 mmHg despite antihypertensive therapy with recommended doses of ACE inhibitor (ACEI) and diuretics. We tested the effect of dual blockade of the renin-angiotensin system (RAS) in these patients. METHODS: We performed a randomised double blind crossover trial with 2 months treatment with Irbesartan 300 mg o.d. and placebo added on top of previous antihypertensive treatment. We included 21 type 1 patients with DN responding insufficiently to ACEI and diuretics, as defined above. At the end of each treatment period, albuminuria, 24-h blood pressure and glomerular filtration rate (GFR) were measured. RESULTS: Addition of 300 mg Irbesartan to the patients' usual antihypertensive therapy induced a mean reduction in albuminuria of 37% (95% CI 20-49, P<0.001); from 1574 mg/24 h (95% CI 1162-2132) to 996 mg/24 h (95% CI 699-1419), a reduction in 24-h blood pressure of 8 mmHg systolic (95% CI -2 to 18) and 5 mmHg diastolic (95% CI 1-9) (P=0.11 and 0.01, respectively) (from placebo, mean (SE) 146 (4)/80 (2) mmHg). GFR remained unchanged. Serum potassium increased (mean 4.3 to 4.6 mmol/l, P=0.02). Intervention to reduce serum potassium was needed in two patients with GFR <35 ml/min/1.73 m(2). Otherwise the dual blockade with Irbesartan was safe and well tolerated. CONCLUSIONS: Dual blockade of the RAS may offer additional renal and cardiovascular protection in type 1 patients with DN responding insufficiently to conventional antihypertensive therapy, including recommended doses of ACEI and diuretics.     

A quantitative light and electron microscopic analysis of taurine-like immunoreactivity in the dorsal horn of the rat spinal cord.

Taurine has been proposed as an inhibitory neurotransmitter or neuromodulator in the vertebrate central nervous system. Within the spinal cord, taurine has been shown to have a direct inhibitory effect on spinal neurons and to have a selective antinociceptive effect on chemically induced nociception. Although sufficient data exists to suggest that taurine plays a neurotransmitter or neuromodulatory role in the spinal cord, it is not known whether this amino acid is present in axon terminals nor if this amino acid has a unique pattern of distribution within spinal tissue. To address these questions a monoclonal antibody against taurine was employed to localize taurine-like immunoreactivity in the dorsal horn of the rat spinal cord by using both light and electron microscopic techniques. Taurine-like immunoreactivity was most dense and most prominent in laminae I and II of the dorsal horn. A moderate amount of immunoreactivity was also present in laminae VIII and IX and X while the remaining laminae were only lightly stained. In laminae I and II taurine-like immunostaining was evident within neuronal cell bodies, dendrites, myelinated and unmyelinated axons, axon terminals, and astrocytes and their processes. Cell counts of these two laminae indicated that approximately 30% of neuronal perikarya at the C2 level, 52% of neuronal perikarya at the T6 level, and 18% of neuronal perikarya at the L2 level of the cord exhibited taurine-like immunoreactivity. With preembedding diaminobenzidine staining, approximately 20% of the axons examined in laminae I and II were found to be immunoreactive for taurine. Using postembedding immunogold staining in combination with quantitative procedures, the highest densities of gold particles were found in axon terminals containing pleomorphic vesicles and forming symmetrical synapses (36.8 particles/micron2), in a subpopulation of myelinated axons (34.2 particles/micron2), in a subpopulation of neuronal dendrites (32.6 particles/micron2), and in capillary endothelial cells (39.8 particles/micron2). Moderate labeling occurred in astrocytes (20.9 particles/micron2) and neuronal perikarya (18.7 particles/micron2). The localization of taurine to presumptive inhibitory axon terminals provides anatomical support for the hypothesis that taurine may serve an inhibitory neurotransmitter role in the superficial dorsal horn of the spinal cord. On the other hand, its localization to astrocytes and endothelial cells within both the dorsal ventral horns implies that it serves other nonneuronal functions as well.     

Cough and converting enzyme inhibitors

Persisting cough developed in three children treated with converting enzyme inhibitors. The symptoms disappeared within 3–7 days after withdrawing medication. These observations in children complement previous reports in adults and indicate that cough may be induced by treatment with these agents.     

Urine as an alternative to urethral swabs for the diagnosis of Chlamydia trachomatis in infertile males

Swabbing the urethrae of men has been the traditional approach for collecting specimens for detection of Chlamydia trachomatis . Recently, however, urine testing using enzyme immunoassay has yielded promising results. A total of 105 patients attending the Andrology Clinic at Ga Rankuwa Hospital, Medunsa were included in the study. These patients were asymptomatic and had no urethral discharge. Three endo-urethral swabs and first-catch urine were collected fiom each patient. The urethral swabs were used for enzyme immunoassay (EIA) (IDEIA 111), tissue culture and direct immonufluorescent antibody (DFA) test (IMAGEN) to detect C. trachomatis . In addition about 15–30 ml of first-catch urine, or urine collected at least 2h after the previous micturition, was collected for each patient for EIA testing. Fifteen (14.3%) of 105 patients were positive on urethral swab EIA, in comparison with the DFA test in which 14 (13.3%) were positive. Eight (7.8%) were positive in tissue culture. Urine EIA was positive in 17 (16.2%) patients, of whom five (4.8%) were positive in urine EIA only. All EIA positive urines were confirmed by DFA. We recommend that first-catch urine or urine collected at least 2h after the previous micturition in infertile males may be considered a suitable alternative to urethral swab for chlamydial diagnosis because it is noninvasive and nontraumatic.     

Phase I Study of Paclitaxel by Three-hour Infusion: Hypotension Just after Infusion Is One of the Major Dose-limiting Toxicities

The primary objectives of this study were to determine the maximum tolerated dose (MTD) of paclitaxel administered by 3-h infusion to patients with solid tumors, and to characterize the pharmacokinetics of a 3-h infusion in comparison with those of a 24-h infusion. Twenty-seven patients each received one of six levels of paclitaxel, 105, 135, 180, 210, 240 and 270 mg/m², with premedication. Two patients given 240 mg/m² and one patient given 270 mg/m² unexpectedly had grade 3/4 hypotension just after finishing the paclitaxel infusion. Peripheral neuropathy was also dose-limiting at 270 mg/m². Although granulocytopenia was significantly less severe than with a 24-h infusion, more than half of the patients experienced grade 4 toxicity at doses of 240 or 270 mg/m². Severe hypersensitivity reactions (HSRs) were not observed. Pharmacokinetic studies using high performance liquid chromatography demonstrated proportionally greater increases in the peak plasma concentration and area under the curve, and decreases in clearance and volume of distribution with increasing dose, suggesting non-linear pharmacokinetics of paclitaxel when given by 3-h infusion. The MTD of paclitaxel given as a 3-h infusion was determined to be 240 mg/m² with dose-limiting toxicities of granulocytopenia, peripheral neuropathy and hypotension. Hypotension just after infusion, induced by 3-h infusion of paclitaxel, is a new observation which has not been reported previously. The recommended dose for phase II study is 210 mg/m². Although hypotension was observed as an unexpected toxic effect, paclitaxel could be administered safely over 3 h with premedication and proper monitoring, resulting in reduced myelotoxicity and with no increase in the incidence of HSRs as compared with a 24-h infusion.     

蝮蛇抗栓酶对骨内高压降压作用实验研究

本实验随机将家兔一侧后肢于膝关节伸直位夹板外固定５周，制成固定侧胫骨上端骨内高压模型。对其全身和局部血液流变学指标进行测定，发现全血粘度，血浆粘度增大，血沉增快，血浆纤维蛋白原含量明显增高。对上述模型应用蝮蛇抗栓酶（ｓｖａｔｅ）连续治疗２１天，骨内压降低，血液流变学各项指标亦降低。本实验结果显示，蝮蛇抗栓酶通过改善骨内高压状态下的异常血液流变学状态可使骨内高压降低，从而认为血液流变学疗法可能成为临床治疗骨内高压症的一种新手段，而蝮蛇抗栓酶可能为其中高效药物之一。     

Indirect detection of anti-acetylcholinesterase compounds in microcolumn liquid chromatography using packed bed reactor with immobilized human red blood cell acetylcholinesterase and choline oxidase

The inhibiting compounds were separated by micro-column liquid chromatography in the mobile phase containing the natural substrate acetylcholine. A home-made packed bed microbioreactor system containing immobilized enzyme acetylcholinesterase (ACHE) in human red blood cell membrane and choline oxidase (CHO) from alcaligenes was used for the post-column conversion of acetylcholine to hydrogen peroxide which was detected by an electrochemical detector. The inhibition effect of the solutes caused a decrease in the acetylcholinesterase activity, a decrease in the formation of hydrogen peroxide and also a decrease in the response corresponding to the concentration of the solutes. The rate of the enzyme regeneration was also recorded. The micro-system was compared with a conventional LC system comprising commercially prepared enzyme reactor. The stability of the enzymes is at least 3 weeks at ambient temperature. The limit of detection depends on biological activity of inhibition and for galanthamine was 1 pmol.