高果糖诱导IR大鼠模型血清脂质代谢的改变及意义

目的: 评估高果糖膳食对机体胰岛素敏感性及血清脂质代谢的影响及意义.方法:以高果糖膳食(果糖占总热量34.5%)诱导并经钳夹技术证实建立胰岛素抵抗(IR)大鼠模型,生化比色法测定血清游离脂肪酸(FFA),生化酶法测定血清甘油三酯(TG)及总胆固醇(TC).结果:高果糖膳食喂养4周后,实验组大鼠葡萄糖输注率由(11.5±0.6)mg/kg·min-1下降至(6.6±0.4)mg/kg·min-1(P<0.01);血清FFA由(0.45±0.09)mmol/L增至(0.78±0.19)mmol/L(P<0.01);TG由(0.54±0.10)mmol/L增至(0.96±0.22)mmol/L(P<0.01);TC由(1.96±0.32)mmol/L增至(2.42±0.21)mmol/L(P<0.01).结论:高果糖膳食可导致机体严重IR,是建立IR大鼠模型的有效手段;该模型同时伴有血清脂代谢各相关指标的明显异常,血脂的变化既是IR的结果,也是IR向纵深发展的原因和必要条件.     

代谢综合征患者瘦素抵抗的研究

目的 :研究代谢综合征 (MS)患者瘦素抵抗的状况。　方法 :选取 5 0例MS患者 (MS组 )和 30例正常人 (正常对照组 ) ,分别测定体重指数 (BMI)、腰臀比 (WHR)、收缩压 (SBP)、舒张压 (DBP)、血清瘦素水平 (leptin)、空腹血糖(FPG)、空腹胰岛素 (FIns)、血清总胆固醇 (TC)、三酰甘油 (TG)、低密度脂蛋白胆固醇 (LDL C)、高密度脂蛋白胆固醇(HDL C)以及脂蛋白 (a)〔LP(a)〕 ,并计算HOMA胰岛素抵抗指数 (HOMA IR)。　结果 :与正常对照组相比 ,MS组血清瘦素水平显著上升 [(2 3.82± 1 5 .6 3) μg/Lvs(1 1 .2 0± 4 .70 ) μg/L ,P <0 .0 1 ],BMI、WHR、SBP、DBP、HOMA IR、TC、TG、LDL C、HDL C亦明显升高 ,而两组间LP(a)差异无显著性意义 (P >0 .0 5 )。　结论 :MS患者血清瘦素水平显著升高 ,可能由于该患者群存在一定程度的瘦素抵抗 ,使正常的脂肪 胰岛素轴反馈机制受到破坏、瘦素抑制胰岛素分泌的能力下降 ,从而导致MS的发生     

P-glycoprotein,multidrug resistance and tumor progression

P-glycoprotein (Pgp) is a plasma membrane protein that was first characterised in multidrug resistant cell lines. The occurrence of Pgp in clinical tumors has been widely studied. Recent investigations have begun to focus on the relationship between Pgp detection in tumors and treatment outcome. In several types of tumors, detection of Pgp correlates with poor response to chemotherapy and shorter survival. P-glycoprotein overexpression often occurs upon relapse from chemotherapy but may also occur at the time of diagnosis. Studies of experimental rat liver carcinogenesis have shown that Pgp expression increases in late stages of carcinogenesis, suggesting that Pgp may be involved in tumor progression. While some of the Pgp isoforms are known to transport hydrophobic chemotherapeutic drugs out of tumor cells, the biologic effects of Pgp overexpression in tumor cells are not fully understood, because the spectrum of substrates for Pgp-mediated transport has not been determined. In the rat liver carcinoma model, strong expression of Pgp is associated with a highly vascular stroma, suggesting that Pgp in tumor cells may affect the connective tissue stroma. The regulation of Pgp appears to be complex, and little is known about how it is up-regulated during carcinogenesis. Further studies of the role of Pgp in malignancy may contribute to our understanding of molecular mechanisms which underlie tumor progression.     

The value of different resistance parameters in distinguishing biopsy-proved dysfunction of renal allografts

The data concerning the value of duplex sonography in diagnosingparenchymatous renal allograft dysfunction are controversial.Most early studies did not take into consideration the manyfactors influencing resistance parameters. We therefore performeda prospective, biopsy-controlled study with exclusion of allknown sources of error regarding resistance parameters. Furthermorewe investigated the value of a new resistance parameter, thesystolic deceleration percentage. Forty-seven duplex sonographicstudies were performed on 43 patients (30 male, 13 female, medianage 47 years, range 7–70). Fourteen studies were doneon normally functioning grafts (control group) an average of33 days after transplantation. Thirty-three studies were performedon dysfunctional grafts immediately prior to biopsy. Graftswhich had been transplanted more than a year previously or withvascular findings or any other clinical or sonographic pathologyprobably explaining function deterioration were excluded. Inall patients, the resistive index (RI), pulsatility index (PI)and systolic deceleration percentage (DP) were calculated inthe main renal artery and in the interlobar artery. Of the 33grafts with dysfunction, nine had vascular rejection (VR), 11interstitial rejection (IR), 11 cyclosporin A toxicity (CAT)and two other histologies (OR). The mean RI in normal grafts(NO) was 0.71±0.06 in the main artery and 0.68±0.06in the interlobar artery, in VR 0.86±0.12 and 0.80±0.18,in IR 0.72±0.05 and 0.70±0.07, in CAT 0.67±0.06and 0.65±0.07 and in OR 0.64±0.07 and 0.60±0.01.For PI, the values were 1.45±0.23 and 1.41±0.28(NO), 3.5±2.13 and 2.92±2.16 (VR), 1.55±0.26and 1.46±0.33 (IR), 1.32±0.25 and 1.27±0.26(CAT) and 1.30±0.34 and 1.13±0.04 (OR). For DPwe calculated 28±5% and 29±6% (NO), 43±14%and 36±6% (VR), 29±9% and 27±9% (IR), 31±8%and 32±7% (CAT ) and 32±4% and 28±3% (OR).The sensitivity/specificity for VR with a cutoff mean+2 SD was0.44/1 for RI, 0.55/0.97 for PI and 0.33/0.89 for DP. It wasconcluded that:(1) despite the high selection of our patientgroup, diagnostic accuracy of duplex sonography for diagnosingparenchymatous function disorder in renal allograft remainsinsufficient; (2) in vascular rejection only, the resistanceparameters differ significantly from the values of normal allografts;(3) the higher the cutoff of resistance parameters, the betterthe specificity and the worse the sensitivity for diagnosingvascular rejection; (4) of all investigated resistance parameters,the RI is the most practical due to a simple measurement technique.     

Increasing prevalence of penicillinase‐producing Neisseria gonorrhoeae and the emergence of high‐level, plasmid‐mediated tetracycline resistance among gonococcal isolates in The Gambia

Summary One hundred and three strains of Neisseria gonorrhoeae isolated from a periurban STD clinic in The Gambia were studied for antimicrobial susceptibility, plasmid profile, and serogroup using standard procedures. Seventy-nine (77%) were penicillinase producers (PPNG) and fully resistant to penicillin (MIC ≥8 mg/l). One isolate showed chromosomally induced resistance to penicillin (MIC 2 mg/l). None of the isolates was sensitive to tetracycline; 16 (16%) showed intermediate resistance (MICs 1–8 mg/l) and 87 (84%) showed high-level plasmid-mediated resistance (TRNG) (MICs >10 mg/l). This is the first report of TRNG in The Gambia. Only 6 (6%) strains were fully sensitive to trimethoprim-sulphamethoxazole (MIC <8 mg/l); 78 (76%) showed intermediate level resistance (MICs 8–16 mg/l) and 19 (18%) were fully resistant (MIC >32 mg/l). Indications of an increase in MIC to ciprofloxacin and ceftriaxone were found in 6 (6%) and 1 (1%) strains, respectively, although all remained fully sensitive (MICs 0.004–0.03 mg/1 and 0.001–0.015 mg/l). All PPNG and TRNG strains carried the 3.2 MDa and 25.2 MDa plasmids, respectively. All isolates carried the 2.6 MDa cryptic plasmid and 9 (3 PPNG and 6 non-PPNG) carried the 24.5 MDa conjugative plasmid. Forty-four (43%) strains were typed group W1, 58 (56%) W11/111 and 1 had cross-reacting antigens. Because PPNG are frequently encountered and high-level TRNG is now prevalent, the newer cephalosporins and quinolones must now be considered as first-line drugs for the treatment of gonorrhoea in The Gambia.     

Changes in bladder function following a surgical alteration in outflow resistance

The changes in bladder function occurring after a surgical alteration in bladder outflow resistance were studied in 20 males undergoing transurethral prostatectomy (TURP) and in 20 females undergoing an endoscopic bladder neck suspension (EBNS). Serial cystometrograms (CMG) were performed before operation, and on alternate days after spontaneous micturition was re-established, for 5 days in the males and for 21 days in the females. CMGs were repeated at 3 months and 1 year after operation. After TURP voiding pressures (P_det) fell rapidly from a mean of 118 cm H₂O before operation to 57 cm H₂O at 5 days, with an increase in flow rate during this time from 10.5 ml/s to 24 ml/s. Detrusor instability that had been present in 14 patients resolved within 2 days in 12. There was no further significant urodynamic change over the 1-year study period. After EBNS, there was an early rise in voiding pressure (P_det rose from 26 cm H₂O before operation to 42 cm H₂O at 3 days). This continued to increase up to 21 days particularly in those patients with initial large residuals. Three patients developed detrusor instability. Flow rates were greatly reduced at first (27 ml/s before operation and 13 ml/s at 3 days), and gradually increased in line with voiding pressures, yet were still diminished 1 year after operation. The urodynamic changes following a reduction in bladder outflow resistance by TURP are immediate and sustained and unlikely to be the result of structural changes within the bladder wall. EBNS produces an increase in outflow resistance and it can be several weeks before balanced voiding is achieved, with significantly increased detrusor pressures needed to achieve complete bladder emptying at a reduced flow rate.     

Methicillin-resistant Staphylococcus aureus: investigation of a hospital outbreak using a case-control study

A retrospective case-control study of 50 MRSA-positive patients was carried out during an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) at an acute general hospital in London. Controls were randomly selected from MRSA-negative patients admitted during the outbreak period. Risk factors investigated included length of admission prior to screening, number of ward changes, main diagnosis, extent of staff contact, pressure sores, surgical and other invasive procedures and antibiotic treatment. Outcome variables examined were rates of infection (versus colonization) with MRSA and mortality. Patients with MRSA were in hospital longer before microbiological specimens were taken and moved wards more often than controls. In a logistic regression analysis, length of stay in hospital, pressure sores, physiotherapy and surgical procedures were associated with a significantly increased risk of acquiring MRSA. Odds ratios (and 95% confidence intervals) for having acquired MRSA were: 8·3 (1·02−71·43) if a patient had pressure sores; 3·7 (1·10−12·5) if they received physiotherapy; and 3·2 (1·82−10·0) if they underwent surgical procedures. The rate of clinical infection amongst patients with this strain of MRSA was 26% and included life-threatening infections such as septicaemia, underlining the potential virulence of MRSA. Surgery and physiotherapy may have been markers of debility. Physiotherapy was probably a marker of increased rates of contact with all hospital staff, and high standards of hand hygiene should be promoted amongst all staff as the most important factor in controlling an outbreak of MRSA. Good bed management is essential for hospital infection control.     

Hereditary Hypertriglyceridemic Rat: A New Animal Model of Metabolic Alterations in Hypertension

Hereditary hypertriglyceridemic rats (hHTg) were developed as a new genetic model for the study of relationships between blood pressure (BP) and metabolic abnormalities. This strain has been produced by selective inbreeding from Wistar rats according to the rise of plasma triglycerides induced by a high-sucrose diet. Though hHTg rats display hypertriglyceridemia, impaired glucose tolerrance, hyperinsulinemia, insulin resistance and increased BP even without nutritional stimuli, high sucrose feeding further aggravates these symptoms. High plasma triglycerides levels in hHTg rats seem to be a consequence of their hyperproduction. Impaired insulin action is responsible for the defective glucoregulation in this strain. The loss of insulin responsiveness might be due to a reduction in the number of glucose transporters. Highly significant relationships among plasma triglycerides, ouabain-resistant Na⁺ transport and BP were demonstrated in the hHTg rats. Segregating populations (F2 hybrids) should be used for genetic analysis of the primary role of lipid and/or ion transport abnormalities in the pathogenesis of this form of genetic hypertension.     

Posture-induced nasal obstruction in patients with allergic rhinitis

Nasal resistance is affected by posture. In this study, the effects of supine and lateral recumbent positions were investigated in eight normal subjects and 31 patients with allergic rhinitis. Of the 31 patients with allergic rhinitis, five showed unilateral complete nasal obstruction and one patient showed bilateral complete obstruction during the change of posture. Total nasal resistance had a tendency to increase with repeating the change of posture (a paired t-test, P < 0.05). The supine and lateral recumbent positions did not induce variable changes in total nasal resistance in normal subjects. Posture induces complete nasal obstruction in the supine or lateral recumbent positions in some patients with allergic rhinitis.     

HIV/AIDS合并深部真菌感染的调查与耐药研究

目的：了解艾滋病病毒／艾滋病(HIV／AIDS)合并深部真菌感染的临床状况、病原菌分类及耐药现状。方法：总结近年来收治的131例HIV/AIDS患者的临床资料，分析深部真菌感染的发生情况及药敏试验结果。结果：HIV／AIDS患者合并深部真菌感染48例，感染率为36．6％，其中以念珠菌为主，占61％，感染部位以消化道为主，占62．7％。随着CD4^ T淋巴细胞的减少，合并深部真菌感染的感染率逐渐增加。念珠菌对益康唑(ECO)、酮康唑(KET)、咪康唑(MIC)、制霉菌素(NYS)、氟康唑(FLU)、伊曲康唑(ITR)、5-氟胞嘧啶(5-FC)、两性霉素B(AMB)耐药率分别为69．4％、66．7％、58．3％、44．4％、43．8％、36．4％、14．3％、13．9％。结论：HIV／AIDS患者合并深部真菌感染率高，且多有药耐药性，特别是对咪唑类抗真菌药物已呈明显耐药，应引起临床医生的高度警惕。