一叶秋碱诱导人白血病HL—60细胞凋亡

目的 研究一叶秋碱能否诱导ＨＬ－６０细胞凋亡,方法 用ＭＴＴ法检测一叶秋碱对细胞增殖影响;应用流式细胞仪检测凋亡细胞数;采用琼脂糖凝胶电泳法观测ＤＮＡ碎片,透射电镜观察凋亡的形态改变,结果：一叶秋碱５－８０ｍｇ．Ｌ＾－１能诱导ＨＬ－６０细胞凋亡,电镜观察到典型的凋亡形态学改变,电泳呈现出阶梯状条带,流式细胞仪检测到凋亡率随剂量的增高而升高,ＭＴＴ法示一叶秋碱抑制ＨＬ－６０细胞增殖,并且呈时间,剂量     

Production of 5–15 µm Diameter Alginate-Polylysine Microcapsules by an Air-Atomization Technique

A novel method of preparing small-sized microcapsules using a Turbotak air-atomizer is reported. Alginate-polylysine microcapsules containing Bacillus Calmette Guérin vaccine have been prepared by an adaptation of the method of Lim (1) which allows the manufacture of small-sized microcapsules. A Turbotak is used to spray sodium alginate solution into calcium chloride solution to form temporary calcium alginate microgel capsules. These temporary microgel droplets are subsequently cross-linked with polylysine to form permanent membranes. Microcapules in the size range of 5–15 µm have been produced which can be compared to an average diameter of 300 µm obtained by the method reported by Lim. The microcapsule size is dependent on the conditions of operation of the Turbotak and the concentration of the sodium alginate solution. Particles within the size range 5–15 µm can be reproducibly manufactured using the conditions of operation reported here. Other size ranges below the minimum of 300 µm reported by Lim are also feasible using this technique.     

Lamivudine for the prevention of hepatitis B virus reactivation in hepatitis B s-antigen seropositive cancer patients undergoing cytotoxic chemotherapy.

PURPOSE: For cancer patients receiving cytotoxic chemotherapy, hepatitis B virus (HBV) reactivation is a well described complication resulting in varying degrees of liver damage. The objectives of this study were to assess the efficacy of the antiviral agent lamivudine in reducing the incidence of HBV reactivation and diminishing morbidity and mortality of cancer patients with chronic HBV infection during chemotherapy. PATIENTS AND METHODS: Two groups were compared in this nonrandomized study. The prophylactic lamivudine group consisted of 65 patients in a phase II study who were treated with lamivudine before and until 8 weeks after discontinuing chemotherapy. The historical controls consisted of 193 consecutive patients who underwent chemotherapy without prophylactic lamivudine. Significant prognosticators for the development of HBV reactivation were determined based on data from the controls. Potential confounding factors were identified between the two groups. The outcomes were compared. RESULTS: In the controls, lymphoma and anthracycline usage were factors identified to be associated with reactivation. The two groups were comparable in most baseline characteristics, although in the prophylactic lamivudine group, there were significantly more patients with lymphoma and receiving anthracyclines. In the prophylactic lamivudine group, there was significantly less HBV reactivation (4.6% v 24.4% in the controls; P <.001), fewer incidences of hepatitis (17.5% v 44.6%; P <.0001) that were less severe (4.8% v 18.7%; P =.0005), and less disruption of chemotherapy (15.4% v 34.6%; P =.0029). The reduction in overall mortality was not statistically different. CONCLUSION: Prophylactic lamivudine significantly reduced the incidence of HBV reactivation and the overall morbidity of cancer patients undergoing chemotherapy.     

Intracranial chondroma of the occipital lobe

A case report of an intracranial chondroma is discussed with emphasis on magnetic resonance imaging.     

Xenon does not alter cardiac function or major cation currents in isolated guinea pig hearts or myocytes

BACKGROUND: The noble gas xenon (Xe) has been used as an inhalational anesthetic agent in clinical trials with little or no physiologic side effects. Like nitrous oxide, Xe is believed to exert minimal unwanted cardiovascular effects, and like nitrous oxide, the vapor concentration to achieve 1 minimum alveolar concentration (MAC) for Xe in humans is high, i.e., 70-80%. In the current study, concentrations of up to 80% Xe were examined for possible myocardial effects in isolated, erythrocyte-perfused guinea pig hearts and for possible effects on altering major cation currents in isolated guinea pig cardiomyocytes. METHODS: Isolated guinea pigs hearts were perfused at 70 mm Hg via the Langendorff technique initially with a salt solution at 37 degrees C. Hearts were then perfused with fresh filtered (40-microm pore) and washed canine erythrocytes diluted in the salt solution equilibrated with 20% O2 in nitrogen (control), with 20% O2, 40% Xe, and 40% N2, (0.5 MAC), or with 20% O2 and 80% Xe (1 MAC), respectively. Hearts were perfused with 80% Xe for 15 min, and bradykinin was injected into the blood perfusate to test endothelium-dependent vasodilatory responses. Using the whole-cell patch-clamp technique, 80% Xe was tested for effects on the cardiac ion currents, the Na+, the L-type Ca2+, and the inward-rectifier K+ channel, in guinea pig myocytes suffused with a salt solution equilibrated with the same combinations of Xe, oxygen, and nitrogen as above. RESULTS: In isolated hearts, heart rate, atrioventricular conduction time, left ventricular pressure, coronary flow, oxygen extraction, oxygen consumption, cardiac efficiency, and flow responses to bradykinin were not significantly (repeated measures analysis of variance, P>0.05) altered by 40% or 80% Xe compared with controls. In isolated cardiomyocytes, the amplitudes of the Na+, the L-type Ca2+, and the inward-rectifier K+ channel over a range of voltages also were not altered by 80% Xe compared with controls. CONCLUSIONS: Unlike hydrocarbon-based gaseous anesthetics, Xe does not significantly alter any measured electrical, mechanical, or metabolic factors, or the nitric oxide-dependent flow response in isolated hearts, at least partly because Xe does not alter the major cation currents as shown here for cardiac myocytes. The authors' results indicate that Xe, at approximately 1 MAC for humans, has no physiologically important effects on the guinea pig heart.     

High serum folate is associated with brain atrophy in older diabetic people with vitamin B12 deficiency

Previous studies have reported the adverse cognitive effects of high folate status in older individuals with vitamin B12 (VB12) deficiency. Thus, the aim of this study was to investigate how high serum folate and VB12 deficiency could collaboratively aggravate neuronal degeneration. In total, 146 older non-demented diabetic individuals with an average age of 75 ± 3.9 were recruited. VB12 deficiency and high folate status were based on high serum methylmalonic acid (MMA) concentrations (> 0.3 μmol/L) and the serum folate concentration being in the top tertile (> 31.4 nmol/L) respectively. Among these subjects, there were 20 with elevated MMA and high folate. The structural magnetic resonance imaging data of these subjects were analyzed by performing flexible factorial analysis with the “folate level” and “MMA level” added as main effects, and the interaction effect of folate and VB12 on brain volume was evaluated. The results showed significant gray matter atrophy of the right middle occipital gyrus and the opercular part of the inferior frontal gyrus in subjects with a simultaneous high folate status and VB12 deficiency. Together with previous observational studies on cognitive function, this study lends support to the notion that high serum folate concentrations in older people with VB12 deficiency may be associated with increased neurodegeneration..