Changes in cytokine secretion patterns of CD4+ T-cell clones in human immunodeficiency virus infection

In addition to the loss of CD4+ T cells in later stages of human immunodeficiency virus (HIV) infection, functional defects of Th cells can already be observed in early infection. Decreased interleukin (IL)- 2 and interferon (IFN)-gamma production by CD4+ T cells and diminished delayed type hypersensitivity reactions are indicative for impaired Th1 responses. We studied the cytokine secretion patterns of T-cell clones (TCC) generated by mitogenic stimulation of CD4+ memory T cells. Compared with TCC from HIV-negative controls, TCC isolated from HIV- infected individuals consistently showed increased IL-4 production, often paralleled by increased IL-5 and decreased IFN-gamma production. This resulted in a decreased percentage of Th1 clones with an increase in Th0 clones. To rule out the influence of interindividual differences, we studied two individuals from whom cells were available before and after infection with HIV. Indeed, an increase in Th2 cytokine secretion was observed after HIV-infection. Loss of Th1 and enhanced Th2 responses might further curtail cellular responses resulting in deficiency of cellular immunity in HIV infection.     

MRI诊断肾肿瘤和术前分期的价值

目的:回顾性分析MRI对肾肿瘤的诊断价值并与病理和随访结果进行对比。方法:对46例疑有肾肿瘤的患者(男33例,女13例,平均年龄64.7岁)行MRI(1.5T)检查,扫描序列包括脂肪抑制TSET2WI、GRET1WI、脂肪抑制3DGRET1WI和增强扫描3DGREMR尿路成像。结果:本组46例中共发现142个肾脏病变,直径从<2cm到14cm×18cm。29例病变位于双侧,17例位于单侧。4例肿瘤为多中心性,其中3例为单肾分布、1例为双肾分布。根据MRI诊断标准,将病变分为囊性和实质性。22例患者可见囊性病变,其中19例为单纯囊性,3例为混合性。43个实体性肿瘤中35个(35/43)经组…     

五子衍宗复方总多糖抗细胞氧化应激损伤和细胞凋亡的研究

目的 对具有肝脏保护作用的中药五子衍宗复方进行分离,考察五子衍宗复方提取物中总多糖抗氧化应激损伤和细胞凋亡的活性.方法 本实验对中药五子衍宗复方的原药材用50%乙醇提取后,通过水提醇沉得到总多糖.利用t -BHP染毒HepG2细胞建立氧化应激损伤模型,检测不同浓度五子衍宗复方总多糖对细胞活力、细胞内活性氧组ROS、脂质...     

Estrogen receptor (ER) gene polymorphism may predict the bone mineral density response to raloxifene in postmenopausal women on chronic hemodialysis

The estrogen receptor (ER) gene has been considered as a candidate genetic marker for osteoporosis, and PvuII and XbaI polymorphisms of the ERalpha gene have been associated with low bone mineral density (BMD). We investigated whether ER polymorphism could predict the response of BMD in 28 postmenopausal women on hemodialysis with marked osteopenia or osteoporosis, randomized to receive raloxifene, a selective estrogen receptor modulator (SERM), or placebo for 1 year. BMD was assessed by dual X-ray absorptiometry and PvuII and XbaI restriction fragment-length polymorphism of the ER gene was determined using polymerase chain reaction. Baseline lumbar spine or femoral neck BMD parameters were not different between patients presenting either homozygous PP or xx when compared with heterozygous Pp or Xx genotypes. After 1 year, patients on raloxifene, presenting with PP or xx genotypes (but not those with Pp or Xx), showed a significantly higher mean lumbar spine BMD (0.942 +/- 0.18 vs. 0.925 +/- 0.17 g/cm2, p < .01) and lower serum pyridinoline (19.7 +/- 9.7 vs. 30.6 +/- 16.5 nmol/L, p < .02) when compared with baseline values. No changes were detected in the placebo-treated patients or in the femur neck sites. In conclusion, after 1 year on raloxifene, postmenopausal osteoporotic women on chronic hemodialysis, homozygous for the P or x (PP or xx) alleles of the ER, exhibited a better lumbar spine BMD response and decreased serum pyridinoline values when compared with heterozygous women (Pp or Xx), suggesting that ERalpha allelic variants may explain, at least in part, the different outcomes after treatment of osteoporosis with SERM.     

Pulmonary hydatid disease mimicking sequestration: Differentiation on magnetic resonance imaging

A case of hydatid disease of the lung proven by thoracotomy and histopathological evaluation is described. It was clinically and radiologically suggestive of a complicated pulmonary sequestration or non-resolving consolidation.     

Chemotherapy for advanced (stage IIIB and stage IV) non-small cell lung cancer: The Hong Kong perspective

Abstract Non-small cell lung cancer (NSCLC) accounts for about 80% of all primary lung cancers, and 60% of cases present as advanced stages IIIB and IV disease. Traditionally, treatment of stages IIIB and IV disease was only symptomatic (including radiotherapy) and supportive care, and cytotoxic chemotherapy was relatively ineffective. Our initial clinical trials, using MACC, FuAM, FAM, Hi-FAM and cisplatin-VP16, gave response rates of 5–20% and a stabilization rate of 7–25%, with no impact on median survival. Our most recent chemotherapy regimen MIP (mitomycin-C, ifosfamide and cisplatin) proved to be more effective with a 44% response rate and a 28% stabilzation rate, and produced a significantly longer median survival (32 weeks) than best supportive care alone (19.5 weeks, P < 0.05). The response rate further increased to 62.5% with dose intensification and GM-CSF support. Chemotherapy can now be recommended to motivated, well-informed patients with good performance status in institutions with experience in cancer chemotherapy on a protocol basis. The most recent addition of new effective cytotoxic agents such as paclitaxel, docetaxel, gemitabine and vinorelbine gave promising results in NSCLC, and optimal combinations and dose schedules are being defined by multicentred studies.     

The Role of Parasympathetic Modulation of the Reentrant Arrhythmic Substrate in the Genesis of Sustained Ventricular Tachycardia

The influence of parasympathetic activity on the reentrant arrhythmic substrate in the genesis of sustained ventricular tachycardia remains unclear. To assess this influence, we studied the heart rate variability in 59 patients referred for invasive electrophysiological testing. In addition, the presence of late potentials and high grade ventricular ectopy, and the left ventricular ejection fraction was determined. The 28 patients with inducible sustained ventricular tachycardia were found to have lower heart rate variability by time- and frequency-domain measurements over 24 hours when compared to the 31 subjects who were noninducible. PNN50 was 4% in the inducible patients, whereas it was 9% in the subjects who were noninducible (P = 0.03). Similarly, HFP24H was 9 and 14 msec, respectively (P = 0.02). MAXHFP1H also differed (20 vs 27 msec [P = 0.04]) but not MINHFP1H (5 vs 6 msec). There was no association between heart rate variability and late potentials, degree of ventricular ectopy, or left ventricular ejection fraction. Thus, vagal tone does not appear to correlate with the presence of late potentials, ventricular ectopy, or left ventricular dysfunction. Low mean as well as maximal vagal tone, in contrast to minimal vagal tone, predicts inducibility of sustained ventricular tachycardia. Our data suggest that the inability to modulate parasympathetic tone appears to be an important determinant in the genesis of reentrant sustained ventricular tachycardia.     

The effect of iron on the biodistribution of bone scanning agents in humans

Nine patients with chronic iron overload, resulting from either repeated transfusions or hemochromatosis, had bone scans that were characterized by a reduction of bony uptake, marked increase in renal activity, and a significant increase in soft-tissue accumulation of 99mTc-labeled bone-seeking agents. These findings were supported by semiquantitative computer analysis. The probable mechanisms of altered biodistribution and the possible role of serum ferritin are discussed. The importance of realizing the effect of excess iron on skeletal scintigraphy is further emphasized by the results of bone scanning in another patient in whom acute iron overload following infusion of iron-dextran resulted in excessive blood pool labeling.     

Mutations and impaired function of LKB1 in familial and non-familial Peutz-Jeghers syndrome and a sporadic testicular cancer

Germline mutations in LKB1 have been reported to underlie familial Peutz-Jeghers syndrome (PJS) with intestinal hamartomatous polyps and an elevated risk of various neoplasms. To investigate the prevalence of LKB1 germline mutations in PJS more generally, we studied samples from 33 unrelated PJS patients including eight non-familial sporadic patients, 20 familial patients and five patients with unknown family history. Nineteen germline mutations were identified, 12 (60%) in familial and four (50%) in sporadic cases. LKB1 mutations were not detected in 14 (42%) patients, indicating that the existence of additional minor PJS loci cannot be excluded. LKB1 is predicted to encode a serine/threonine kinase. To demonstrate the putative Lkb1 kinase function and to study the consequences of LKB1 mutations in PJS and sporadic tumors, we have analyzed the kinase activity of wild-type and mutant Lkb1 proteins. Interestingly, while most of the small deletions or missense mutations resulted in loss-of-function alleles, one missense mutation (G163D) previously identified in a sporadic testicular tumor demonstrated severely impaired but detectable kinase activity.      

Comparative Study of Leaf and Stem Bark Extracts of Parkia Biglobosa Against Enterobacteria

Hydroethanolic and aqueous extracts of leaf and stem bark of Parkia biglobosa (Jacq) Benth. (Mimosaceae) were tested against clinical isolates Escherichia coli, Salmonella typhi, Shigella dysenteriae and Enterococcus faecalis, and corresponding collection strains E. coli CIP 105 182, Salmonella enterica CIP 105 150, Shigella dysenteriae CIP 54-51 and Enterococcus faecalis CIP 103 907. Discs of Gentamicin, a broad spectrum antibiotic were used as positive controls. The results showed that all the extracts possess antimicrobial activities. A comparative study of the antibacterial activity of the leaves and that of the bark showed that for all the tested microorganisms, the hydroalcoholic extract of the bark is more active than the aqueous extract of the leaf. The hydroethanolic extract of the leaves is as effective as the aqueous extract of the stem bark prescribed by the traditional healer, suggesting it is possible to use leaves other than the roots and bark. The phytochemical screening showed that sterols and triterpenes, saponosides, tannins, reducing compounds, coumarins, anthocyanosides, flavonosides are present in both bark and leaf but in different concentrations.