Compared with control subjects,the systemic sympathetic nervous system is activated in patients with mitral regurgitation

Background

Whether the systemic sympathetic nervous system is activated as a compensatory mechanism in response to mitral regurgitation (MR) in humans is unknown. We tested the hypotheses that the systemic sympathetic nervous system would be activated in patients with MR in comparison with control subjects and that this activation would occur early in the disease process as a compensatory mechanism for chronic left ventricular (LV) volume overload.

Methods

We studied 37 patients with MR who underwent right heart catheterization and biplane cineventriculography to obtain LV end-diastolic and end-systolic volumes, ejection fractions, and regurgitant volumes. In these 37 patients with MR and in 23 control subjects, an [³H]-norepinephrine ([³H]-NE) infusion and multiple arterial blood samples provided data for a 2-compartment modeling analysis to calculate extravascular NE release rates (NE₂).

Results

The mean NE₂ (2.05 ± 0.76 μg/min/m²) in the patients with MR was greater than that in the control subjects (1.48 ± 0.75 μg/min/m², P = .007). Furthermore, the mean NE₂ values were also greater in the patients with MR who were in clinical class I (P = .05), with a pulmonary capillary wedge pressure <12 mm Hg (P = .05) or a LV ejection fraction ≥0.60 (P = .06) compared with the control subjects. The mean NE₂ values were increased further in patients with MR who had a LV ejection fraction <0.60 (P = .02).

Conclusions

The systemic sympathetic nervous system is activated in patients with MR in comparison with control subjects, and this activation appears to occur early in the disease process as a compensatory mechanism for LV volume overload.     

The effects of seven monophasic oral contraceptive regimens on hemostatic variables: conclusions from a large randomized multicenter study

We investigated the effects of ethinylestradiol dose (50, 30 and 20 μg) and progestogen type [desogestrel (DSG), gestodene (GSD), levonorgestrel (LNG) and norgestimate (NGM)] in oral contraceptives on 24 hemostatic variables. In a multicenter, randomized, comparative study, 707 healthy, nonsmoking, nulliparous women were treated for six cycles with one of the seven monophasic oral contraceptives tested. Significantly greater increases in prothrombin fragment 1+2 and factor VII (activity and antigen), were found in the DSG, NGM and GSD groups compared to the LNG group. Similarly, significantly lower levels of protein S (free and total) and increased APC-sr (endogenous thrombin potential based) were found in the same groups compared with the LNG group. In addition, the estradiol dose (50 vs. 30 μg) significantly influenced these parameters. All changes were within the normal range and have not been associated with an increased risk of venous thromboembolic event (VTE). However, raised levels of these variables are associated with prothrombotic states such as pregnancy. The significance of the haemostatic changes found in this study in relation to VTE risk remains to be determined, but results of this study probably cannot explain the differences in risk of VTE between OCs containing different progestogens.     

AgNORS在六亚甲基二乙酰胺诱导涎腺粘液表皮样癌细胞分化研究中的表达和意义

粘液表皮样癌是涎腺恶性肿瘤中最常见的一种。本实验以六亚甲基二乙酰胺（ＨＭＢＡ）作为分化诱导剂,对涎腺粘液表皮样癌ＭＥＣ－１细胞进行了体内外诱导,并通过银染技术对对照组和ＨＭＢＡ诱导组癌细胞核内核仁组成区（ＮＯＲＳ））的数目、大小及分布特征进行了观察。结果表明：经ＨＭＢＡ诱导后的癌细胞,细胞核内嗜银颗粒的数目明显较对照组少,且直径变大,分布趋于集中。说明在ＨＭＢＡ作用下,癌细胞向成熟方向发生了一定分化,ＡｇＮＯＲＳ技术在诱导分化研究中有一定应用价值。     

先天性腭裂术后腭咽闭合功能的动态观察

根据咽腔造影后,咽腔侧位、颅底正位X线片的测量以及电视透视及电视录像观察,67例腭裂术后患者吞咽时均能达到完全的腭咽闭合,而用力吹气和发音时大部分不能形成完全的腭咽闭合,用力吹气时腭咽闭合较发音时容易,发辅音时腭咽闭合较发元音时容易。腭咽闭合的部位在腭板以下、第一颈椎以上的水平上。腭咽部活动时咽后壁动度不大。     

Intensive, long-term plasma exchange therapy for severe hypertriglyceridemia in acquired generalized lipoatrophy.

We report dramatic improvement in clinical and laboratory parameters after intensive plasma exchange therapy in a 15-yr-old girl with acquired generalized lipoatrophy and refractory hypertriglyceridemia. One hundred and twenty-five procedures were performed over 720 d. Two or three plasma volumes were exchanged per procedure, using peripheral venous access and albumin as replacement solution. Regression of painful cutaneous xanthomata and reduction in massive hepatomegaly were noted within the first two procedures. Triglyceride levels started at 109 mmol/liter (9670 mg/dl) and decreased acutely by 60-85%/procedure. Lipid removal averaged 83 g/procedure and was highly correlated with preexchange lipid levels. Lipid levels rebounded to baseline values within 7 d after exchange and appeared to rebound more rapidly after larger exchanges. Maximum benefit was achieved with weekly 1.5- to 2.0-volume exchanges. No significant decrease in apolipoprotein CII levels was detected after plasma exchange regardless of the volume of exchange; however, other plasma factors regulating triglyceride synthesis or clearance may have been removed during the procedures. Plasma exchange was well tolerated, without clinical, immunological, or hormonal deterioration. These data indicate that intensive plasma exchange therapy over a protracted time may produce sustained benefit in patients with severe, symptomatic hypertriglyceridemia refractory to standard medical therapy.     

Cross-resistance and associated resistance in <Emphasis Type="Italic">Escherichia coli</Emphasis> isolates from nosocomial urinary tract infections between 2004–2006 in a Turkish Hospital

In this study, antimicrobial resistance profiles were determined for 748 isolates of Escherichia coli from patients with acute nosocomial urinary tract infections (UTIs) at a Turkish Training Hospital. Thirteen antibiotics were included. Resistance to ampicillin alone (45.1%) and ciprofloxacin alone (20.6%) were the most commonly identified ‘single resistances’. Multiple resistance was found in 49.7% of the strains. The most common multiple antibiotic resistance profiles included ampicillin-sulbactam/amoxycilline-clavulonate (4.0%) and ampicillin-sulbactam/trimethoprim-sulfamethoxazole/amoxycilline-clavulonate (2.8%). From 2004 to 2006, ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin resistant strains increased to 76% from 57%, 53% from 43% and 55% from 41%, respectively. The percentage of extended-spectrum β-lactamase (ESBL) producing strains was 7.8% and imipenem resistance was seen in 5.2% of ESBL positive strains. We conclude that clinically important E.coli strains have now emerged with broader multidrug resistance. Periodical evaluation of laboratory results and clinical surveillance are crucially important for optimal antibiotic management of UTIs and infection control policies.