Expression of inducible nitric oxide synthase in the liver of bile duct-ligated Wistar rats with modulation by lymphomononuclear cells

BACKGROUND: The current study evaluated whether biliary tract obstruction stimulates inducible nitric oxide synthase (iNOS) protein expression in the liver and analyzed the implication of lymphomononuclear cells and interleukin-4 (IL-4). METHODS: Male Wistar rats were used. Bile flow interruption was achieved by a complete division of the extrapancreatic common bile duct. iNOS expression was determined by both the Western blot technique and immunohistochemistry. RESULTS: iNOS protein was markedly expressed in the liver 7 days after bile duct obstruction. Treatment with thymostimulin (TP-1), a partially purified thymic extract, reduced the intensity of the expression of iNOS protein in the liver after bile duct ligation. Recent data have suggested that IL-4 attenuates iNOS protein expression. We then analyzed the involvement of this anti-inflammatory cytokine on the modulation of iNOS expression in the liver. The liver from rats that underwent bile duct ligation (BDL) showed a lower content of IL-4 than that of sham-operated (SO) rats. TP-1 treatment increased the content of IL-4 in the liver. Liver slices incubated in vitro with Escherichia coli lipopolysaccharide (LPS, 10 microg/mL) stimulated the expression of iNOS protein. The level of LPS-induced iNOS expression was reduced by lymphomononuclear cells obtained from sham-operated animals. However, lymphomononuclear cells isolated from BDL rats potentiated the induction of iNOS expression by LPS-stimulated liver. However, lymphomononuclear cells from TP-1-treated BDL rats failed to modify LPS-stimulated iNOS expression. The different effect of lymphomononuclear cells on the modulation of iNOS expression in the liver was associated with their ability to generate IL-4. CONCLUSIONS: The liver of jaundiced rats markedly expressed iNOS protein, which was associated to modifications in the content of IL-4 in the liver. Furthermore, lymphomononuclear cells modulate iNOS protein expression in the liver by a mechanism in which IL-4 is involved.     

Influence of tolrestat on the defective leukocyte-endothelial interaction in experimental diabetes

One of the most devastating secondary complications of diabetes is the blunted inflammatory response that becomes evident even in the very early stages of poorly controlled diabetes mellitus. While the etiology of this diminished response is not clearly understood, it has been linked to a decrease in the respiratory burst of neutrophils, as well as a decrease in microvessel response to inflammatory mediators and defective leukocyte-endothelial interactions. Using video microscopy to visualize vessels of the internal spermatic fascia, we have characterized leukocyte-endothelial interactions in alloxan-induced diabetic and in galactosemic rats by quantitating the number of leukocytes rolling along the venular endothelium and the number of leukocytes sticking to the vascular wall after topical application of zymosan-activated plasma or leukotriene B(4) (1 ng/ml), as well as after the application of a local irritant stimulus (carrageenan, 100 microg). We observed that while 33 days of alloxan-induced diabetes or 7 days of galactosemia had no effect on total or differential leukocyte counts and on the wall shear rate, both treatments significantly (P<0.001) reduced the number of leukocytes rolling along the venular endothelium by about 70% and the number of adhered leukocytes in postcapillary venules by 60%. These effects were not observed in diabetic and galactosemic animals treated with an aldose reductase inhibitor. The results suggest that impaired leukocyte-endothelial cell interactions are a consequence of an enhanced flux through the polyol pathway.     

Doxazosin and soluble guanylate cyclase in a rat model of hypertension]

BACKGROUND: Although different studies have evaluated the ability of endothelial cells to produce NO in the setting of the endothelial dysfunction associated with hypertension, less it is known about the soluble guanylate cyclase system. AIM: To analyze the level of expression of sGC in the vascular wall in Stroke-prone spontaneously hypertensive rats (SHRSP). Moreover, the effect of treatment with an alpha1 adrenergic antagonist, doxazosin, on sGC expression was also evaluated. METHODS: The study was performed in 24 untreated 20-week-old SPSHR and 12 SPSHR treated orally with doxazosin (10 mg/Kg bw/day; for 15 days). A group of normotensive Wistar-Kyoto (WKY) rats were used as controls (n = 12). RESULTS: Isolated aortic segments from SHRSP showed impaired response to SNP. Doxazosin treatment prevented impaired vasodilatory response to SNP. Expression of the beta1 sGC in the vascular wall of SHRSP determined by Western blot and immunohistochemistry was markedly reduced with respect to that of WKY. Doxazosin treatment increased of beta1 sGC expression in treated SHRSP particularly at the medium level with respect to that of untreated SHRSP. CONCLUSION: SHRSP showed reduced expression of beta1 sGC in the vascular wall and an impaired vasodilator response to SNP which improved with doxazosin treatment. These results suggest the role the sGC system may play in the global treatment of endothelial dysfunction.     

Enhancement of aorta tonus evoked by hypertonic solutions is endothelium-dependent.

1. The effect of NaCl hypertonic solutions on the contractions induced by noradrenaline or prostaglandin F2 alpha and on the relaxant effect of acetylcholine and sodium nitroprusside was investigated in aortae with or without endothelium isolated from rats. 2. Hypertonic solutions enhanced the contractions elicited by the vasoconstrictor agents in preparations with endothelium and this phenomenon was not altered by previous treatment of the animals with reserpine or the preparations with methylene blue or indomethacin. 3. In hypertonic medium acetylcholine but not sodium nitroprusside vasodilator effect was inhibited. 4. We suggest that NaCl hypertonic solutions modify vascular reactivity probably through: (i) the release of an endothelium-derived contracting factor not sensitive to cyclooxygenase inhibitors; (ii) a diminished release of an endothelium-derived relaxing factor not related to the cGMP system.     

成纤维细胞分泌胶原蛋白与5-氟尿嘧啶的时间抑制效应

目的:观察5-氟尿嘧啶干预体外培养病理性瘢痕成纤维细胞增殖和胶原合成的作用及其时效关系。方法:实验于2005-05/2006-06在安徽医科大学微生物教研室完成。①原代细胞培养成纤维细胞:手术取4例增生性瘢痕、4例瘢痕疙瘩、4例正常皮肤组织,按文献方法进行成纤维细胞原代培养,待细胞融合后传代。②取4～6代传代细胞接种于96孔板,利用四唑盐比色法测定25g/L浓度5-氟尿嘧啶干预不同时间(1,2,5,10,15,30min)后3种体外培养成纤维细胞的增殖能力,统计得出最佳时效。③利用3H-脯氨酸掺入法检测经5-氟尿嘧啶干预不同时间后成纤维细胞的胶原蛋白分泌能力。结果:①原代培养成纤维细胞全部成活,形态良好,经5-氟尿嘧啶干预后细胞形态未发生明显变化。②四甲基偶氮唑盐法测3种不同来源成纤维细胞未干预时增殖能力,瘢痕疙瘩成纤维细胞>正常皮肤成纤维细胞(t=3.542,P<0.01),增生性瘢痕成纤维细胞>正常皮肤成纤维细胞(t=3.257,P<0.01);5-氟尿嘧啶干预成纤维细胞10min与5min比较,其对成纤维细胞的抑制效果增高(正常皮肤、增生性瘢痕、瘢痕疙瘩3种成纤维细胞10minA值依次为0.389±0.027,0.418±0.051,0.554±0.021;5minA值依次为0.537±0.033,0.589±0.074,0.783±0.015,q=3.80～4.18,P<0.05),与30min比较,差异无显著性。③干预10min3H-脯氨酸掺入量与空白对照组比较明显下降,差异有显著性(q=3.82～3.96,P<0.05),与5min干预组比较,差异均有显著性(q=3.96～4.14,P<0.05),与30min比较,差异无统计学意义。结论:5-氟尿嘧啶可有效抑制病理性瘢痕及正常皮肤来源的成纤维细胞体外增殖和胶原合成,干预10min时效应最佳。     

PAF-acether and endotoxin display similar effects on rat mesenteric microvessels: inhibition by specific antagonists

The activity of platelet activating factor (PAF-acether) and the effects of specific antagonists BN 52021 and WEB 2086 on microvessels were studied. The mesentery of anaesthetized male Wistar rats was exteriorized and arranged for microscopic observation of the microcirculation in situ. Vessel diameters were measured with an image splitting micrometer adjusted to the phototube of the microscope. Images were displayed on the monitor screen of a closed-circuit television system. Topical application of PAF (10, 100 and 200 microM) enlarged the diameter of mesenteric arterioles and venules, which was antagonized by PAF antagonists administered i.v. (1 mg/kg) or topically (10 microM). Bolus injection (1 micrograms/kg) or perfusion (100 ng/kg/min) of PAF significantly decreased mean arterial blood pressure of the animals and slightly increased arteriolar diameters. These effects were blocked by the PAF antagonists. Endotoxin (10-20 mg/kg i.v.) significantly enlarged arteriolar diameters and produced a significant drop of arterial blood pressure. These effects were blocked by the PAF antagonists at doses equivalent to those used to antagonize the effects of PAF. The leukocyte activator fMLP, as well as lyso-PAF and PAF antagonists, were devoid of effects on the microcirculation when applied topically or injected i.v. We conclude that mesenteric microvessels contribute to the hypotensive effect of PAF and endotoxin and that PAF is released at the mesenteric area during endotoxic shock.     

A cross-sectional study to assess the prevalence of DSM-5 specific learning disorders in representative school samples from the second to sixth grade in Brazil

Little is known about specific learning disorder (SLD) in low- and middle-income countries (LMICs), and even less from representative school samples in small size cities outside huge urban centers. Few studies addressed the new DSM-5 criteria for SLDs. We investigated the prevalence of DSM-5 SLDs, their comorbidities and correlates in school samples of students from the second to sixth grades living in median cities from four different geographic regions in Brazil. A national test for academic performance covering reading, writing and mathematical abilities was applied. Psychiatric diagnoses were assessed by the K-SADS-PL applied to the primary caregiver. A total of 1618 children and adolescents were included in the study. The following prevalence rates of SLDs were found: 7.6 % for global impairment, 5.4 % for writing, 6.0 % for arithmetic, and 7.5 % for reading impairment. Attention-deficit/hyperactivity disorder (ADHD) was the only comorbidity significantly associated with SLD with global impairment (p = 0.031). Anxiety disorders and ADHD were associated with SLD with arithmetic impairment. Significant differences were detected in prevalence rates among cities, and several socio-demographic correlates (age, gender, IQ, and socioeconomic status) were significantly associated with SLD with global impairment in our sample. Careful validation and normatization of instruments to assess academic performance is a major problem in LMICs. As expected, we found a significant heterogeneity in prevalence rates of SLD according to geographic regions considering that Brazil is a country with a robust diversity. SLD with global and arithmetic impairment was significantly associated with psychiatric comorbidities.     

Inconsistent leukocyte removal by IBM 2991 blood cell processor

Studies done in the 1970's have documented the efficiency of leukocyte removal by saline washing using the IBM 2991 Blood Cell Processor. In June 1982, an evaluation of 52 consecutive units washed using the IBM 2991 yielded results for leukocyte removal that varied considerably from the results determined by previous published studies. Evidence from our institution and others within the last year supports a recent alteration in the ability of the IBM 2991 to remove leukocytes. Since the machine has not changed considerably since previous successful studies, alterations in the product being washed need to be considered as a cause of the inconsistency in leukocyte removal by the IBM 2991. Until consistent leukocyte-removal can be achieved, individual blood banks should carefully scrutinize their washed units and be prepared for possible leukocyte-associated reactions.     

应用遥测肌电技术实测分析人体助行带的生物力学作用

目的:人体助行带为一种随身佩带的动力装置,应用遥测肌电技术测定和分析自行研制的人体助行带的生物力学作用机制。方法:实验于2005-12/2006-06在天津体育大学运动生物力学实验室进行。选取天津市天津医院30名受试对象,均对本实验知情同意。按照生物力学的测试要求,首先对受试者进行5次以上行走状态下的遥测肌电测定,然后在同等条件下对受试者佩带助行带实施对照研究。实验采用的助行带为自行研制的,由腰至足以双层弹力带作为动力装置的弹性结构。结果:行走摆动相大腿肌肌电:佩带助行带后肌内侧肌、肌二头肌、半腱肌肌电高于佩带前(P<0.01)。支撑相小腿肌肌电:佩带助行带后胫前肌、腓骨长肌、腓肠肌肌电高于佩带前(P<0.01)。结论:通过弹力带施加于下肢的外部载荷,能够起到增强下肢肌电以及产生助行的生物力学功效。