筋脉通胶囊对高糖培养雪旺细胞睫状体神经营养因子表达的影响

目的探讨筋脉通胶囊对糖尿病周围神经病变的作用及其机制。方法以Wistar大鼠按成人剂量15倍给药分别制成筋脉通和神经妥乐平含药血清。实验分为空白对照组(不加细胞)、正常对照组(加入正常大鼠血清)、高糖组(加入葡萄糖)、筋脉通组(加入筋脉通含药血清和正常大鼠血清)、神经妥乐平组(加入神经妥乐平含药血清),除空白对照组和正常对照组之外,其余各组均加入50mmol/L葡萄糖培养高糖雪旺细胞模型。采用免疫荧光法检测高糖培养雪旺细胞睫状体神经营养因子(CNTF)的表达,实时荧光定量PCR法检测CNTF-mRNA的表达。结果与正常对照组相比,高糖组、筋脉通组、神经妥乐平组雪旺细胞CNTF及CNTF-mRNA的表达均降低(P0.01);与高糖组相比,筋脉通组与神经妥乐平组雪旺细胞CNTF及CNTF-mRNA表达均增高(P0.01);且筋脉通组雪旺细胞CNTF-mRNA表达较神经妥乐平组增高(P0.05)。结论筋脉通胶囊可以上调高糖培养雪旺细胞CNTF蛋白及其mRNA的表达,从而对糖尿病周围神经病变具有一定的改善作用。     

Snake bites by the jararacucu (Bothrops jararacussu): clinicopathological studies of 29 proven cases in Sao Paulo State, Brazil

The jararacucu, one of the most dreaded snakes of Brazil, southern Bolivia, Paraguay and northeastern Argentina, is a heavily-built pit viper which may grow to a length of 2.2 m. Up to 1000 mg (dry weight) of highly-lethal venom may be milked from its venom glands on a single occasion. It has accounted for 0.8% to 10% of series of snake bites in Sao Paulo State, Brazil. We examined 29 cases of proven jararacucu bites recruited over a 20-year period in two Sao Paulo hospitals. Severe signs of local and systemic envenoming, (local necrosis, shock, spontaneous systemic bleeding, renal failure) were seen only in patients bitten by snakes longer than 50 cm; bites by shorter specimens were more likely to cause incoagulable blood. Fourteen patients developed coagulopathy, six local necrosis (requiring amputation in one) and five local abscesses. Two became shocked and four developed renal failure. Three patients, aged 3, 11 and 65 years, died 18.75, 27.75 and 83 h after being bitten, with respiratory and circulatory failure despite large doses of specific antivenom and intensive-care- unit management. In two patients, autopsies revealed acute renal tubular necrosis, cerebral oedema, haemorrhagic rhabdomyolysis at the site of the bite and disseminated intravascular coagulation. In one survivor with chronic renal failure, renal biopsy showed bilateral cortical necrosis; the patient remains dependent on haemodialysis. Effects of polyspecific Bothrops antivenom were not impressive, and it has been suggested that anti-Bothrops and anti-Crotalus antivenoms should be given in combination.      

Quercetin inhibits the growth of leukemic progenitors and induces the expression of transforming growth factor-beta 1 in these cells

We previously showed that quercetin (3,3',4',5,7 pentahydroxyflavone) inhibits in a dose-dependent manner the growth of acute leukemias and is able to enhance the antiproliferative activity of cytosine arabinoside. We show here that quercetin inhibits the clonogenic activity of 20 of 22 acute leukemias (AL; 4 M1-AML, 3 M2-AML, 2 M3-AML, 3 M4-AML, 3 M5-AML, and 7 ALL). In the present report, we show that the induction of transforming growth factor-beta 1 (TGF-beta 1) in leukemic blasts is one of the growth-inhibitory mechanisms of quercetin in these cells. This observation was supported by the following data. (1) Quercetin-sensitive leukemic blasts, when treated with quercetin, secrete large amounts of TGF-beta 1 in the medium and show positivity for TGF-beta 1-immunoreactive material in the cytoplasm. (2) At a concentration of 8 mumol/L, antisense TGF-beta 1 oligonucleotides prevent the growth-inhibitory action of quercetin. (3) Anti-TGF-beta 1 neutralizing monoclonal antibodies can prevent almost completely the growth-inhibitory activity of quercetin. The analysis of quercetin- resistant cases confirmed as well the central role of TGF-beta 1 in the growth-inhibitory activity of quercetin. In conclusion, quercetin can act as a cytostatic agent for leukemic cells by modulating the production of TGF-beta 1.     

Ontogeny of hematopoietic stem cell development: reciprocal expression of CD33 and a novel molecule by maturing myeloid and erythroid progenitors

We have identified a molecule expressed by human marrow granulocyte/monocyte colony-forming cells (CFU-GM), erythroid colony- forming cells (CFU-E), and erythroid burst-forming units (BFU-E), but not their precursors detectable in long-term bone marrow culture. This antigen, detected by flow microfluorimetry using monoclonal antibody 7B9, is coexpressed with CD33 on many CD34+ CFCs, although only the 7B9 antigen was detected on a portion of BFU-E and CFU-E, whereas only CD33 was found on a portion of CFU-GM. Antibody 7B9 appears to be useful for isolating subsets of progenitors based on their common or selective expression of 7B9 antigen and CD33.     

Activation of muscarinic receptors elicits inotropic responses in ventricular muscle from rats with heart failure through myosin light chain phosphorylation

Background and purpose:

Muscarinic stimulation increases myofilament Ca²⁺ sensitivity with no apparent inotropic response in normal rat myocardium. Increased myofilament Ca²⁺ sensitivity is a molecular mechanism promoting increased contractility in failing cardiac tissue. Thus, muscarinic receptor activation could elicit inotropic responses in ventricular myocardium from rats with heart failure, through increasing phosphorylation of myosin light chain (MLC).

Experimental approach:

Contractile force was measured in left ventricular papillary muscles from male Wistar rats, 6 weeks after left coronary artery ligation or sham surgery. Muscles were also frozen, and MLC-2 phosphorylation level was quantified.

Key results:

Carbachol (10 µmol·L⁻¹) evoked a positive inotropic response only in muscles from rats with heart failure approximating 36% of that elicited by 1 µmol·L⁻¹ isoproterenol (20 ± 1.5% and 56 ± 6.1% above basal respectively). Carbachol-evoked inotropic responses did not correlate with infarction size but did correlate with increased left ventricular end diastolic pressure, heart weight/body weight ratio and lung weight, primary indicators of the severity of heart failure. Only muscarinic receptor antagonists selective for M₂ receptors antagonized carbachol-mediated inotropic effects with the expected potency. Carbachol-evoked inotropic responses and increase in phosphorylated MLC-2 were attenuated by MLC kinase (ML-9) and Rho-kinase inhibition (Y-27632), and inotropic responses were abolished by Pertussis toxin pretreatment.

Conclusion and implications:

In failing ventricular muscle, muscarinic receptor activation, most likely via M₂ receptors, provides inotropic support by increasing MLC phosphorylation and consequently, myofilament Ca²⁺ sensitivity. Enhancement of myofilament Ca²⁺ sensitivity, representing a less energy-demanding mechanism of inotropic support may be particularly advantageous in failing hearts.     

Evaluating patients with renal failure for renal artery stenosis with gadolinium-enhanced magnetic resonance angiography

The incidence and prevalence of end-stage renal disease (ESRD) continues to increase, especially in the elderly population. The role of renovascular disease in contributing to ESRD is still not well defined. The objective of this study was to determine the utility of gadolinium (Gd)-enhanced magnetic resonance angiography (MRA) in evaluating elderly patients with renal insufficiency for renal artery stenosis (RAS). A 7-month prospective study conducted in a tertiary referral center evaluated 40 consecutive patients with progressive renal insufficiency (18 men and 22 women; mean age, 70 +/- 5.6 [standard deviation] years) and high clinical suspicion for renovascular disease with Gd-enhanced MRA. Digital subtraction angiography (DSA) was obtained in only those patients with significant RAS detected by MRA. Twelve patients had significant RAS. Six of these patients had percutaneous transluminal renal angioplasty (PTRA), five patients had renal artery bypass surgery, and one patient had a stent placed after PTRA. Seventy-eight renal arteries were satisfactorily evaluated by MRA. Twenty-two renal arteries were evaluated by both MRA and DSA. Of the 12 significant stenoses detected by the MRA, 11 were confirmed by DSA and 1 was confirmed at the time of surgical revascularization. It is concluded that Gd-enhanced MRA is a useful test for the evaluation of RAS in patients with compromised renal function.     

Granulomatous hypophysitis: presentation and MRI appearance

Granulomatous hypophysitis (GrHy) is a relatively rare inflammatory disease compared with lymphocytic hypophysitis. Only a few cases with magnetic resonance imaging (MRI) findings have been reported to date. We describe the MRI findings for two patients with GrHy with unusual histories and clinical outcomes.     

Expandable intraluminal graft: a preliminary study. Work in progress

To overcome the problem of recurrence of stenosis after vascular balloon dilatations, we developed an expandable, intraluminal graft that allows dilatation of the lesion and simultaneous placement of a supportive endoprosthesis to prevent recoil of the arterial wall. The graft is made of continuous, woven, stainless steel wire. The resulting tubular mesh has a wall thickness of 200-450 micron and 80% open surface. The grafts, mounted on angioplasty catheters, are introduced through 8-12-F Teflon sheaths. Eleven grafts of 6, 8, and 10 mm in diameter by 20 mm long were placed in the aorta, common carotid, superior mesenteric, iliac, and renal arteries of dogs. Six grafts showed no stenosis in follow-up studies of up to 8 weeks. Two grafts had moderate stenosis as a result of neointimal hyperplasia. Two partial and one complete graft thrombosis occurred in nonheparinized animals in which the graft outflow was restricted. Anticoagulant was not used on a long-term basis. Light and electron microscopy studies showed complete covering of the graft's inner surface by endothelium at 3 weeks.