Angiotensin-II stimulates nitric oxide release in isolated perfused renal resistance arteries

 Nitric oxide (NO) has been implicated as a modulator of the vascular effects of angiotensin II (ANG II) in the kidney. We used a NO-sensitive microelectrode to study the effect of ANG II on NO release, and to determine the effect of selective inhibition of the ANG II subtype I receptor (AT1) with losartan (LOS) and candesartan (CAN). NO release from isolated and perfused renal resistance arteries was measured with a porphyrin-electroplated, carbon fiber. The vessels were microdissected from isolated perfused rat kidneys and perfused at constant flow and pressure in vitro. The NO-electrode was placed inside the glass collection cannula to measure vessel effluent NO concentration. ANG II stimulated NO release in a dose-dependent fashion: 0.1 nM, 10 nM and 1000 nM ANG II increased NO-oxidation current by 85±18 pA (n = 11), 148±22 pA (n = 11), and 193±29 pA (n = 11), respectively. These currents correspond to changes in effluent NO concentration of 3.4±0.5 nM, 6.1±1.1 nM, and 8.2±1.3 nM, respectively. Neither LOS (1 μM) nor CAN (1 nM) significantly affected basal NO production, but both AT1-receptor blockers markedly blunted NO release in response to ANG II (10 nM): 77±6% inhibition with LOS (n = 8) and 63±9% with CAN (n = 8). These results are the first to demonstrate that ANG II stimulates NO release in isolated renal resistance arteries, and that ANG II-induced NO release is blunted by simultaneous AT1-receptor blockade. Our findings suggest that endothelium-dependent modulation of ANG II-induced vasoconstriction in renal resistance arteries is mediated, at least in part, by AT1-receptor-dependent NO release. Received: 24 September 1997 / Accepted: 20 October 1997     

Determination of trace selenium in human body by anodic stripping voltammetry at gold-disc electrode

Summary For determination of trace Se we used high-pressure wet digester to pretreat the specimens obtained from the human body. This method is very effective in preventing loss of Se by volatilization which often occurs in the sample pretreatment. We studied the method of using anodic stripping voltammetry at gold-disc electrode to measure the trace Se present in the human body and found it to be the optimal procedure. The detection limitation was about 2x10⁻⁸ g/L, the recovery rate of Se about 96.6±6,7 % , and the coefficient of variation CV = 7.0%.     

川芎嗪对兔眼高压下视网膜神经节细胞和双极细胞损伤的保护作用

目的　观察川芎嗪对慢性眼高压下视网膜神经细胞损伤的保护作用 .方法　用 2 0 g· L- 1 甲基纤维素前房注射法建立兔慢性眼高压模型 .4组分别给予生理盐水、川芎嗪注射液 10 mg· kg- 1 ,2 .5 g· L- 1 噻吗心安眼液和联合应用川芎嗪与噻吗心安 ,连续用药 4wk.于 2 8d取眼球作光镜、电镜检查和光镜下细胞计数 .结果　生理盐水组模型眼节细胞数为 (7.83± 1.34 )个 /10格 ,双极细胞数为 (10 .6 6± 1.6 3)个 /格 ;川芎嗪组模型眼节细胞数为 (9.5 0± 3.87)个 /10格 ,双极细胞数为 (12 .5 0± 2 .73)个 /格 ;生理盐水组模型眼和川芎嗪组模型眼节细胞 (P<0 .0 5 )与双极细胞 (P<0 .0 5 )比较 ,有显著性差异 .生理盐水组模型眼节细胞变性、坏死 ,锥、杆细胞外节紊乱 ,色素上皮不完整 ,川芎嗪组变化比生理盐水组轻 ,联合用药组变化最小 .结论　川芎嗪对慢性眼高压下视网膜神经节细胞和双极细胞具有保护作用 .     

苯并三氮唑和4—羧基苯并三氮唑对铜缓蚀作用

采用光电化学方法和交流阻抗方法将不同浓度的ＢＴＡ（苯并三氮唑）和４ＣＢＴＡ（４－羧基苯并三氮唑）在硼砂缓冲溶液（ｐＨ９．２）中对铜电极的缓蚀性能作了比较。发现在阳性向电位扫描中,一定农度的ＢＴＡ作用下,铜电极光响应由ｐ型转化为ｎ型,并可依此判断缓蚀剂的缓蚀性能。ｎ型光响应越大,缓蚀剂的缓蚀性能越好;而在４ＣＢＴＡ作用下,铜电极光响应保持ｐ型,然其阴极向扫描中最大光电汉变化明显,并可据此判断缓蚀剂诉     

聚氯乙烯膜盐酸奎宁选择电极的研制与应用

目的及方法 :本文首次使用鞣酸与六价铬形成的络合物为沉淀剂 ,使其与奎宁形成的分子缔合物为电活性物 ,制备了一种新型的 PVC膜盐酸奎宁选择电极。结果 :电极的 Nernst响应范围为 1.0× 10 - 1～ 1.0× 10 - 5 mol/ L;斜率为 5 3m V/ p C;检测限为 7.0× 10 - 6 mol/ L。结论 :此电极响应迅速 ,重现性好 ,用此电极以标准曲线法对药物中的盐酸奎宁进行了测定 ,操作简便 ,结果与药典法相符     

CT引导经皮肺穿刺锚状电极高温射频消融治疗肺部肿瘤105例

目的 观察ＣＴ引导经皮肺穿刺高温射频消融治疗１０５例肺部恶性肿瘤的近期效果。方法 ＣＴ引导经皮肺穿刺,可扩展锚状电极配合ＲＦ－２０００仪高温射频消融治疗原发性肺癌８１例,肺部转移瘤２４例,共计２４２个肿瘤,每个肿瘤治疗３～８次,持续时间３～３３７ｍｉｎ。结果 完全缓解（ＣＲ）率１１．１％,部分缓解（ＰＲ）率７１．１％,轻微疗效（ＭＲ）率１３．２％,无改变（ＮＣ）率４．５％,其中ＣＲ＋ＰＲ率为８２．     

Bipolar disorders and narcissism: Diagnostic concerns,conceptual commonalities and potential antecedents

Narcissistic personality disorder (NPD) and the manic and hypomanic episodes found in the bipolar disorders are characterized by grandiosity. It is possible that this shared grandiosity is a ‘homologous structure’ or reflects a superficial similarity between two disparate conditions. It is, however, possible that NPD and the bipolar disorders are more closely related than implied by their segregation into the separate superordinate categories of personality disorders and mood disorders. Whereas narcissism is considered to be a life-course, stable trait and the bipolar disorders are characterized by episodes of mania and depression, there is considerable research indicating that narcissism may be linked to mood instability (including depression) and bipolar disorder may have a pervasive personality component (i.e., hypomanic personality). Utilizing dimensional models of psychopathology, the current review examined the evidence linking narcissism and the bipolar disorders and suggests that considerable overlap may exist in the domains associated with reward-seeking, harm avoidance and social functioning.     

A two-illness model of bipolar disorder

The current approach to mood disorders is that bipolar disorder, comprising both mania and depression, is a discreet illness distinct from unipolar depression. This formulation has profoundly influenced the approach to understanding the biology and etiology of these disorders, as well as the manner in which the various phases of bipolar disorder are treated. Our new model suggests that bipolar disorder comprises two distinct illnesses, mania and depression, and that bipolar depression is no different from unipolar depression. Studies of clinical syndromes, course of illness, family history and genetics, biological factors, and treatment response data directly or indirectly support this new model.     

Gabapentin in the acute treatment of refractory bipolar disorder

Background: Gabapentin, a new anti-epileptic agent, has been anecdotally reported to be effective in the treatment of mania. We systematically assessed the response rate in bipolar patients being treated adjunctively with gabapentin for manic symptoms, depressive symptoms, or rapid cycling not responsive to standard treatments.
Method: Twenty-eight bipolar patients experiencing manic (n=18), depressive (n=5), or rapid-cycling (n=5) symptoms inadequately responsive to at least one mood stabilizer were treated in an open fashion with adjunctive gabapentin. Illness response was assessed using the Clinical Global Impression Scale modified for bipolar disorder (CGI-BP). A 'positive response' was operationalized as a CGI response of much or very much improved.
Results: Fourteen of the 18 (78%) treated for hypomania or mania had a positive response to a dosage range of 600–3600 mg/day. Patients with hypomania responded fastest, with a positive response achieved in 12.7±7.2 days. Patients with classic mania had a mean time to positive response of 25±12 days, and in patients with mixed mania it was 31.8±20.9 days. All of the five patients treated for depression had a positive response within 21±13.9 days. Only one of five patients with rapid cycling had a positive response. Gabapentin was well tolerated by all patients, with the most common side-effect being sedation.
Conclusions: Gabapentin appears to have acute anti-manic and anti-depressant properties as an adjunctive agent for refractory bipolar illness. Prospective double-blind studies are needed to further delineate its acute efficacy when used as monotherapy and its prophylactic efficacy as monotherapy or in conjuction with other mood stabilizers.