两个时期肾结核的临床比较

目的：探讨近年来肾结核的流行病学和临床变化趋势.方法：对收治的842例肾结核患者,以1980年底为界,分为先期组和近期组进行临床比较.结果：两组患者分别：占同期泌尿外科住院人数的8.74%和1.95%（P＜0.05）;就诊年龄中位数为28岁、38岁;病程平均为33.6个月、45.9个月.尿频91.1%,66.0%;血尿82.6%、64.7%;伴发肺结核18.4%、12.3%;伴发膀胱结核37.2%、19.6%;伴发附睾结核47.0%、36.6%（以上各项均P＜0.05）;IVU检查阳性率分别为90.0%、85.9%.结论：肾结核发病率近年来明显下降,其典型临床表现比例降低,不典型肾结核病例呈明显增加趋势.     

免疫抑制剂对嗜铬细胞瘤12细胞和L929细胞增殖的影响

目的 初步探讨多种免疫抑制剂对嗜铬细胞瘤12（pheochromocytoma 12，PC12）细胞和L929细胞增殖的影响。方法 对数生长期PC12细胞和L929细胞传代，取细胞株复苏后第3代细胞均以1×10^6／ml密度接种于培养板中，分别加入10、10、10^-7和10^8mol／L环孢菌素A（cyclosporin A，CsA），10^-6、10^-7、10^-8和10^-9mol／LFK506以及10^-3、10^-4、10^-6和10^-8mol／L甲基强地松龙，并设立空白对照组。于培养24、48和72h后，取各浓度药物作用的细胞，采用MTT法检测细胞增殖。结果 高浓度（10mol／L）甲基强地松龙和较低浓度（10^-8～10^-7mol／L）CsA，在给药后48h内对PCI2细胞增殖有明显促进作用，此后促增殖作用不明显；而各个浓度的FK506均无促进PCI2细胞增殖的作用。高浓度甲基强地松龙（10^-3mol／L）和CsA（10^-6～10mol／L）作用24h后，对L929细胞增殖有显著抑制作用，FK506仅在较高浓度（10^-6mol／L）有一过性（仅出现于给药后48h）促进L929细胞增殖的作用。结论 10^-3mol／L甲基强地松龙和10^-8～10^-7mol／LCsA能够在短时间内促进PC12细胞增殖，而10^-3mol／L甲基强地松龙和10^-6～10^-5mol／L CsA对L929细胞增殖有显著抑制作用。     

Investigation of serotonin receptors in the isolated penile bulb of rats

The aim of this study was to investigate serotonin (5-HT) receptors in the penile bulb, which have been suggested to play a role in penile erection. Serotonin (10(-7)-3 x 10(-4) M) contracted penile bulbs in a concentration-dependent manner. Ketanserin (5-HT(2A) antagonist, 10(-9)-10(-7) M) and prazosin (alpha(1)-adrenergic receptor blocker, 10(-9)-10(-7) M) suppressed the lower and upper parts of concentration-response curves to 5-HT, respectively. Guanethidine (adrenergic neuron blocker, 5 x 10(-5) M) reduced the responses to 5-HT at only 10(-4) and 3 x 10(-4) M concentrations. NAN-190 (5-HT(1A) antagonist, 10(-8), 10(-7) M) shifted the concentration-response curve to the right with a reduction in the maximum response to 5-HT. While ondansetron (5-HT(3) antagonist, 10(-6)-10(-5) M) and GR55562 (5-HT(1B/1D) antagonist, 10(-6)-10(-5) M) had no effect on the concentration-response curve to 5-HT. The 5-HT(1A) agonist 8-OH-DPAT (10(-7)-3 x 10(-4) M) contracted penile bulbs in a concentration-dependent manner with a lower pD(2) value than that of 5-HT. Sumatriptan (5-HT(1B/1D) agonist, 10(-8)-10(-4) M) did not produce any contractile response in the penile bulbs. Prucalopride, a selective 5-HT(4) agonist (R093877, 10(-7)-3 x 10(-4) M) produced concentration-dependent relaxation in penile bulbs contracted by phenylephrine (10(-5) M). 5-HT(4) agonists cisapride (10(-7)-10(-4) M) and metoclopramide (10(-7)-3 x 10(-4) M) also relaxed the tissue, concentration-dependently. Selective 5-HT(4) antagonists GR125487 (10(-6)-10(-5) M) and GR113808 (10(-6)-10(-5) M) slightly, but not significantly, decreased prucalopride- and cisapride-induced relaxation. Propranolol (beta-adrenergic receptor blocker, 10(-6)-10(-5) M) and L-NOARG (nitric oxide synthase inhibitor, 10(-4) M) had no effect on prucalopride-induced relaxation. These results suggest the existence of alpha(1)-adrenergic, 5-HT(1A) and 5-HT(2A) serotonergic receptors in the penile bulb of rats, which are responsible for 5-HT-induced contraction. Additionally, a serotonergic receptor resembling a 5-HT(4)-type plays a role in the relaxation. The latter receptor is activated by 5-HT(4) agonists, but is not antagonized by 5-HT(4) antagonists.     

Effects of vitamin D compounds on renal and intestinal Ca2+ transport proteins in 25-hydroxyvitamin D3-1alpha-hydroxylase knockout mice

BACKGROUND: Vitamin D compounds are used clinically to control secondary hyperparathyroidism (SHPT) due to renal failure. Newer vitamin D compounds retain the suppressive action of 1,25(OH)(2)D(3) on the parathyroid glands and may have less Ca(2+)-mobilizing activity, offering potentially safer therapies. METHODS: This study investigated the effect of a single dose of compound (1,25(OH)(2)D(3), 1,24(OH)(2)D(2), or 1alpha(OH)D(2)) on renal and intestinal Ca(2+) transport proteins, including TRPV5 and TRPV6, and serum Ca(2+), in a novel SHPT model, the 25-OH-D(3)-1alpha-hydroxylase knockout mouse, which lacks endogenous 1,25(OH)(2)D(3) and is severely hypocalcemic. Animals were injected intraperitoneally with compound (100 ng/mouse). RESULTS: Serum levels of 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2) peaked at four hours post-injection (pi), then declined rapidly. 1,25(OH)(2)D(2) generated from 1alpha(OH)D(2) peaked at 12 hours pi and then remained stable. Serum Ca(2+) was increased to near-normal within four hours by 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2), and within 12 hours by 1alpha(OH)D(2). 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2) up-regulated duodenal TRPV5 and TRPV6 mRNA to a similar degree within four hours; mRNA levels decreased by 12 hours after 1,24(OH)(2)D(2) treatment, and by 24 hours after 1,25(OH)(2)D(3) treatment. 1,25(OH)(2)D(3) increased kidney levels of TRPV5, calbindin-D(28K), and calbindin-D(9K) mRNA within four hours; 1,24(OH)(2)D(2) did not change kidney TRPV5 levels and modestly increased calbindin D(9K) by 48 hours. 1alpha(OH)D(2) produced later-onset effects, increasing duodenal TRPV6 and calbindin-D(9K) mRNA levels by 12 hours and TRPV5 by 48 hours. CONCLUSION: In kidney, 1alpha(OH)D(2) increased TRPV5, calbindin-D(28K), and calbindin-D(9K) mRNA levels by 12 hours. This study indicates that Ca(2+) transport proteins, including TRPV5 and TRPV6, are differentially up-regulated by vitamin D compounds.     

内镜超声检查和多层螺旋CT对胃癌术前T、N分期的比较研究

目的探讨内镜超声(endoscopicultrasonography,EUS)与多层螺旋CT(multi slicespiralCT,MSCT)在胃癌术前T、N分期中的临床应用价值。方法2000年10月至2002年5月,对89例活检证实的胃癌病人术前分别行内镜超声和多层螺旋CT检查,并与手术病理结果对照。结果EUS对胃癌术前T分期的准确率为75.6%,其中T176.5%,T268.8%,T384.4%,T464.7%;MSCT分别79.3%,58.8%,62.5%,90.6%和94.1%。两者差异无统计学意义(P>0.05)。EUS对胃癌术前N分期的准确率为57.5%,其中N095.8%,N145.8%,N232.0%;MSCT分别78.1%,70.8%,75.0%和88.0%。EUS和MSCT对胃癌淋巴结转移的敏感性分别为61.2%和91.8%。EUS对N0分期的准确率显著高于MSCT(P<0.05),MSCT对N和N2分期的准确率及淋巴结转移的敏感性均显著高于EUS(P<0.05,P<0.01,P<0.01)。结论内镜超声检查与多层螺旋CT对胃癌术前TN分期均有较高的准确性。     

A Prospective Randomized Study Comparing Two Different Techniques for Laparoscopic Sleeve Gastrectomy

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) represents a relatively new restrictive operation for obesity. We report a prospective randomized study comparing two different techniques of performing this procedure. METHODS: Between January and August 2006, 20 patients (group A) and 20 patients (group B) were prospectively and randomly submitted to LSG. The characteristics of the patients in the two groups were similar for age and sex. The median preoperative weight was of 120 kg (95-180) (A) and 133 kg (83-175) (B) (NS). The median preoperative BMI was of 42.5 kg/m2 (35-58) (A) and 47 kg/m2 (37-58) (B) (NS). The two techniques differ in that in A, stapling is performed after full devascularization and mobilization of the gastric curve, whereas in B stapling is performed as soon as the lesser sac is entered and the greater curve is devascularized after full completion of the sleeve. The staple-line is reinforced at the end of stapling in both techniques. RESULTS: Median operative time was 34 min (12-54) (A) and 25 min (9-51) (B) (P = 0.06). Median peroperative bleeding was 5 mL (0-450) (A) and 5 mL (0-100) (B) (P = 0.37). Median number of staple cartridges used was 6 (5-7) (A) and 6 (4-7) (B) (P = 0.63). Peroperative complications were a small hiatal hernia requiring repair and a bleeding in two patients of A. Postoperative leak occurred in 1 patient of A, and minor early complications affected 2 patients of A and 1 patient of B. Peroperative and postoperative mortality was 0. Median hospital stay was 3 days (1-10) (A) and 3 days (2-7) (B) (P = 0.59). One stenosis as a late complication appeared in a patient of B. %EWL at 6 months and 1 year was respectively 43.4% (A), 42.2% (B) and 48.3% (A) 49.5% (B) (P = 0.82). CONCLUSION: LSG can be performed by two different techniques. The technique B (section of the stomach followed by its mobilization) appears familiar to surgeons usually performing laparoscopic RYGBP. No observed differences are significant, but the technique B when looking at observed distributions, seems to be better than the technique A (mobilization of the stomach followed by its section) in terms of operative time, peroperative bleeding and hospital stay.     

Performance of automated air tonometry under hypothermia

Intestinal tonometry is used during hypothermic cardio-pulmonary bypass surgery to assess splanchnic perfusion. In an in vitro set-up the performance of automated air tonometry (TONOCAP) was tested for normo- and hypothermia. A 14-FG tonometry catheter was built into a testing chamber (100 cm(3)) perfused with blood from a cardio-pulmonary bypass circuit with P(a)co(2) held at 5.6-5.8 kPa (alpha-stat). P(r)co(2) from the balloon of the tonometry catheter was measured at intervals of 10 min at 37 degrees C and at 25 degrees C by the TONOCAP. Bias (precision) of P(r)co(2) - P(a)co(2 alpha-stat) and P(r)co(2) -P(a)co(2 pH-stat) at 37 degrees C blood temperature were low at 0.23 kPa (0.21) each. Tonometrically measured P(r)co(2) at 25 degrees C significantly differed from P(a)co(2 alpha-stat) bias (precision) of 2.00 kPa (0.11) but was similar to P(a)co(2 pH-stat) (0.30 kPa (0.11)). P(r)co(2) values as measured by the TONOCAP represent pH-stat approach. Identical blood gas management (pH- or alpha-stat) should be used for calculation of mucosal-arterial CO(2) difference (P(r-a)co(2) gap) or calculation of intramucosal pH.     

中国成人桡骨近端解剖形态测量及研究

目的 测量和研究桡骨近端解剖形态特点,为设计解剖型的桡骨头假体提供数据.方法 对男、女各24例成年肱骨外上髁炎患者的肘关节进行MRI扫描,通过软件测量桡骨近端的解剖参数,包括桡骨头的直径与高度、桡骨头关节面深度、桡骨颈高度、桡骨颈髓腔狭窄处的直径等.采用SPSS16.0软件包进行数据统计,研究桡骨头近端各解剖参数间的相关关系.结果 桡骨头最大直径(Rmax)及最小直径(Rmin)分别为[(23.1±5.3)mm,-/x±s,下同]和(21.8±5.0)mm,桡骨头高度(H1)及桡骨颈高度(Hn)分别为(11.3±2.3)mm和(11.8±4.8)mm,桡骨颈髓腔狭窄处最大直径(Dmax)和最小直径(Dmin)分别为(10.6±2.7)mm和(9.0±2.5)mm,桡骨头关节面最大深度(Oep)为(2.1±0.6)mm.男性桡骨头Rmax和min分别为(25.1±4.2)mm和(23.7±4.0)mm,H1及Hn分别为(11.9±1.9)mm(12.2±3.9)mm,Dmax及Dmin分别为(11.1±2.5)mm和(9.6±2.2)mm,Dep为(2.2±0.6)mm.女性Rmax和Rmin面分别为(21.1±2.3)mm和(19.9±2.2)mm,H1及H2分别为(10.7±1.9)mm和(11.5±5.6)mm,Dmax和Dmin分别为(10.0±2.6)mm和(8.4±2.3)mm,Dep为(2.0±0.6)mm.男性和女性的各项指标相比,差异有统计学意义(P<0.05).Rmax和Rmin之间差异有统计学意义(P<0.05),两者之间呈线性相关,相关关系为Rmin=0.95×Rmax°Rmax和Rmin之间差异有统计学意义(P<0.05),两者之间呈线性相关,相关关系为Dmin=0.85×Dmax°桡骨头和桡骨颈髓腔大小之间以及桡骨头、颈高度之间的相关关系较为离散.结论 桡骨近端解剖形态为椭圆形,圆形桡骨头假体设计不能很好地体现桡骨头的解剖特点,较少的选择余地和一体化的设计不能满足临床实际需要,而装配型假体能更灵活地应对各种临床变异情况.     

Estradiol-17beta stimulates phosphate uptake and is mitogenic for primary rabbit renal proximal tubule cells

The direct effects of estradiol-17beta (E(2)) on phosphate (P(i)) uptake and on DNA synthesis in the primary rabbit kidney proximal tubule cells (PTCs) have been investigated. In the present study, E(2) (>10(-9) M, over 9 days) causes an increase both in [(3)H]thymidine incorporation and the number of PTCs. The anti-estrogen tamoxifen completely prevented the E(2)-induced increase in [(3)H]thymidine incorporation, and ameliorated the stimulatory effect of E(2) on growth. E(2) (>10(-9 )M, over 5 days) also stimulated the P(i) uptake and its effect was due to the V(max) values but not to the K(m) value for P(i) uptake. Estriol and estrone also exerted significant stimulatory effects on P(i) uptake. Progesterone, tamoxifen, actinomycin D and cycloheximide prevented the E(2)-induced stimulation of P(i) uptake. In conclusion, estrogens at physiological concentrations stimulate P(i) uptake and DNA synthesis in the renal proximal tubule cells, and these effects are estrogen receptor mediated.     

Vascular injuries in the urban battleground: experience at a metropolitan trauma center

The increasing frequency and severity of urban violence and vehicular injuries have brought with them a rise in the number of complex vascular injuries. To examine the cause, incidence, management, and outcome of this problem, we created a vascular trauma registry which includes all such cases treated at a Level I metropolitan trauma center over the past nine years. This constitutes a summary report of that registry. During the period 1979-1988, 411 patients (355 men, 56 women) with 478 vascular injuries were treated. There were 18 deaths (4%). Primary diagnosis was grouped by anatomic region: (1) head and neck vessels, 62 (15%); (2) thoracic, 39 (10%); (3) abdominal and pelvic, 63 (15%); (4) upper extremity, 161 (39%); and (5) lower extremity, 86 (21%). Surgery was required in 241 cases (60%). Operative techniques consisted of ligation or resection in 26 (12%) and direct repair in 212 (88%). Associated procedures included: (1) laparotomy (n = 83); (2) craniotomy (n = 4); (3) thoracotomy (n = 49); (4) orthopedic procedures (n = 118); and (5) peripheral neurological repair (n = 70). Mechanisms of injury were: (1) gunshot wounds (32%); (2) stab wounds (45%); (3) motor vehicle accidents (18%); (4) fall (3%); and (5) other mechanisms (2%). We conclude: (1) vascular injuries were found frequently in the severely injured patient; (2) multiple vascular repairs were required in a significant proportion of these patients; and (3) outcome is dependent more upon associated trauma than on the vascular injuries themselves.     

Upregulation of group IB secreted phospholipase A(2) and its M-type receptor in rat ANTI-THY-1 glomerulonephritis

Treatment of rat glomerular mesangial cell (GMC) cultures with pancreatic secreted phospholipase A(2) (sPLA(2)-IB) results in an enhanced expression of sPLA(2)-IIA and COX-2, possibly via binding to its specific M-type sPLA(2) receptor. In the current study, we have investigated the expression and regulation of sPLA(2)-IB and its receptor during glomerulonephritis (GN). In vivo we used the well-established rat model of anti-Thy 1.1 GN (anti-Thy 1.1-GN) to study the expression of sPLA(2)-IB and the M-type sPLA(2) receptor by immunohistochemistry. In addition, in vitro we determined the interkeukin (IL)-1beta-regulated mRNA and protein expression in primary rat glomerular mesangial and endothelial cells as well as in rat peripheral blood leukocytes (PBLs). Shortly after induction of anti-Thy 1.1-GN, sPLA(2)-IB expression was markedly upregulated in the kidney at 6-24 h. Within glomeruli, the strongest sPLA(2)-IB protein expression was detected on infiltrated granulocytes and monocytes. However, at the same time, the M-type receptor was also markedly upregulated on resident glomerular cells. In vitro, the most prominent cytokine-stimulated secretion of sPLA(2)-IB was observed in monocytes isolated from rat PBLs. Treating glomerular endothelial cells (GECs) with cytokines elicited only weak sPLA(2)-IB expression, but treatment of these cells with exogenous sPLA(2)-IB resulted in a marked expression of the endogenous sPLA(2)-IB. Mesangial cells did not express sPLA(2)-IB at all. The M-type sPLA(2) receptor protein was markedly upregulated on cytokine-stimulated mesangial and endothelial cells as well as on lymphocytes and granulocytes. During anti-Thy 1.1 rat GN, sPLA(2)-IB and the M-type sPLA(2) receptor are induced as primary downstream genes stimulated by inflammatory cytokines. Subsequently, both sPLA(2)-IB and the M-type sPLA(2) receptor are involved in the autocrine and paracrine amplification of the inflammatory process in different resident and infiltrating cells.     

Changes in vitamin D metabolites during teriparatide treatment

Parathyroid hormone (PTH) increases the conversion of 25-hydroxyvitamin D [25(OH)D] to 1,25 dihydroxyvitamin D [1,25(OH)(2)D]. The purpose of this study was to assess the changes in serum concentration of vitamin D metabolites 1,25 dihydroxyvitamin D [1,25(OH)(2)D] and 25-hydroxyvitamin D [25(OH)D] during teriparatide 20 μg/day (teriparatide) therapy in the double-blind Fracture Prevention Trial of postmenopausal women with osteoporosis and in the male study of men with osteoporosis. Patients were randomized to teriparatide or placebo and received daily supplements of calcium 1000 mg and vitamin D 400-1200 IU. Serum concentrations of 1,25(OH)(2)D and 25(OH)D were measured. In women (N=336), median 1,25(OH)(2)D concentrations at 1 month increased from baseline by 27% (P<0.0001) in the teriparatide group versus -3% (P=0.87) in the placebo group (between group P<0.0001). At 12 months, the increase was 19% (P<0.0001) in the teriparatide group versus -2% (P=0.23) in the placebo group (P<0.0001). Median 25(OH)D concentrations at 12 months decreased by 19% (P<0.0001) in the teriparatide group versus 0% (P=0.13) in the placebo group (P<0.0001). In men (N=287), median 1,25(OH)(2)D concentrations at 1 month increased by 22% (P<0.0001) in the teriparatide group versus 0% (P=0.99) in the placebo group (P<0.0001). At 12 months, the increase was 14% (P<0.0001) in the teriparatide group versus 5% (P=0.004) in the placebo group (P=0.17). Median 25(OH)D concentrations at 12 months decreased by 11% (P=0.001) in the teriparatide group versus an increase of 1% (P=0.20) in the placebo group (P=0.003). Therefore, treatment with teriparatide increases 1,25(OH)(2)D concentrations and decreases 25(OH)D concentrations.     

In vivo turnover study demonstrates diminished clearance of lipoprotein(a) in hemodialysis patients

Lipoprotein(a) (Lp(a)) consists of a low-density lipoprotein-like particle and a covalently linked highly glycosylated protein, called apolipoprotein(a) (apo(a)). Lp(a) derives from the liver but its catabolism is still poorly understood. Plasma concentrations of this highly atherogenic lipoprotein are elevated in hemodialysis (HD) patients, suggesting the kidney to be involved in Lp(a) catabolism. We therefore compared the in vivo turnover rates of both protein components from Lp(a) (i.e. apo(a) and apoB) determined by stable-isotope technology in seven HD patients with those of nine healthy controls. The fractional catabolic rate (FCR) of Lp(a)-apo(a) was significantly lower in HD patients compared with controls (0.164+/-0.114 vs 0.246+/-0.067 days(-1), P=0.042). The same was true for the FCR of Lp(a)-apoB (0.129+/-0.097 vs 0.299+/-0.142 days(-1), P=0.005). This resulted in a much longer residence time of 8.9 days for Lp(a)-apo(a) and 12.9 days for Lp(a)-apoB in HD patients compared with controls (4.4 and 3.9 days, respectively). The production rates of apo(a) and apoB from Lp(a) did not differ significantly between patients and controls and were even lower for patients when compared with controls with similar Lp(a) plasma concentrations. This in vivo turnover study is a further crucial step in understanding the mechanism of Lp(a) catabolism: the loss of renal function in HD patients causes elevated Lp(a) plasma levels because of decreased clearance but not increased production of Lp(a). The prolonged retention time of Lp(a) in HD patients might importantly contribute to the high risk of atherosclerosis in these patients.     

The effect of cisplatin dose and surgical resection in children with malignant germ cell tumors at the sacrococcygeal region: a pediatric intergroup trial (POG 9049/CCG 8882)

PURPOSE: This study was designed to evaluate (1) the efficacy of standard or high-dose cisplatin with etoposide and bleomycin and (2) the role of surgical resection in infants and children with malignant germ cell tumors of the sacrococcygeal region (SCT). METHODS: Seventy-four of 317 children presenting to Pediatric Oncology Group (POG)/Children's Cancer Group (CCG) institutions from 1990 through 1996 with malignant germ cell tumors had malignant SCT. There were 62 girls and 12 boys with a median age of 21 months (range, 3 days to 37 months) and median serum alpha-fetoprotein of 35,500 ng/mL. Twelve had undergone resection of a benign SCT as a newborn. Forty-four (59%) had evidence of metastatic disease at time of diagnosis. Presentation by type (Altman classification) was I, 0; II, 2; III, 30; and IV, 42. The initial procedure was biopsy in 45 and resection in 29. Patients were assigned randomly to receive 4 cycles of chemotherapy with etoposide (E) and bleomycin (B) and either high-dose cisplatin (200 mg/m(2) per cycle; HDP) or standard dose cisplatin (100 mg/m(2) per cycle; P). After completion of chemotherapy, 42 of 45 initially treated with biopsy underwent resection. RESULTS: Overall 4-year survival rate is 90% (SE = 4%) and 4-year event-free survival (EFS) is 84% (SE = 6%). Event-free survival data for subgroups of interest are as follows: 4-yr EFS% (SE) P Values Mets (44) 88 (6).48 No Mets (30) 80 (8) HDP EB (37) 89 (6).21 P EB (37) 78 (7) Initial Resection (29) 90 (7).50 Delayed Resection (42) 83 (7) Complete Resection (49) 90 (5).19 CR/PR Partial Resection (22) 77 (10) Biopsy Only (3) 33 (27).005 (3 way) CONCLUSIONS: (1) The current survival rate of malignant sacrococcygeal tumors is excellent even with metastases. (2) Delayed surgical resection is not associated with an adverse outcome. (3) In this subset the treatment comparison was inconclusive however, followed the trend in the overall study of more than 300 children in which the high-dose cisplatin group had superior EFS (P<.05).     

Vasoactive intestinal polypeptide receptor VPAC(1) subtype is predominant in rat prostate membranes.

BACKGROUND: The 28-amino-acid neuropeptide vasoactive intestinal peptide (VIP) might play an important role in the physiology of the prostate, since it stimulates glandular secretion, inhibits muscle contraction, stimulates proliferation of epithelial cells, and increases the secretion of prostate-specific antigen (PSA). This neuropeptide may act through interaction with two types of high-affinity receptors, named VPAC(1) and VPAC(2) receptors. Recently, selective agonists and antagonists for each receptor subtype were synthesized. We used them to identify the VIP receptor subclass expressed in rat prostatic tissue. METHODS: We tested the capacity of selective labeled and unlabeled agonists and antagonists of VPAC(1) and VPAC(2) receptors to bind to rat prostatic membranes and to stimulate or prevent the stimulation of adenylate cyclase activity. RESULTS: The following selective peptides were used: VPAC(1) agonist ([K(15), R(16), L(27)] VIP (1-7)/GRF (8-27)); VPAC(1) antagonist (PG 97-269); and VPAC(2) agonist (RO 25-1553). The IC(50) values of [(125)I]-VIP binding inhibition for the different peptides in rat prostatic membranes were: VIP (1.7 nM) < VPAC(1) agonist (20 nM) < VPAC(1) antagonist (40 nM) < VPAC(2) agonist (329 nM). The EC(50) values of adenylate cyclase stimulation were similar to the IC(50) values for each peptide, and the Ki values for the VPAC(1) antagonist, inhibiting the adenylate cyclase activity stimulated by VIP and the VPAC(1) agonist, were 22 and 35 nM, respectively. Comparison of binding of [(125)I]-VIP and of [(125)I]-RO 25-1553 indicates the presence of 80% of VPAC(1) and 20% VPAC(2) receptors. CONCLUSIONS: In rat prostate membranes, VPAC(1) receptors are largely predominant. Binding studies were compatible with a ratio of 80/20 of VPAC(1)/VPAC(2) receptors, whereas functionally only VPAC(1) receptors were detected.     

Nitrous oxide and xenon increase the efficacy of GABA at recombinant mammalian GABA(A) receptors

We investigated the interactions between recombinant gamma-aminobutyric acid receptor complex (GABA(A)R) and nitrous oxide (N(2)O) or xenon (Xe). Human embryonic kidney cells (HEK 293) were transfected with rat cDNA for alpha(1)beta(2)gamma(2L) or for alpha(1)beta(2) recombinant GABA(A)R subunits. Patch clamp techniques were used in the whole-cell mode to evaluate the effect of N(2)O and Xe on GABA-induced currents. A piezo-driven "liquid filament switch" was used for fast application. Both N(2)O (100%, 29.2 mM) and Xe (100%, 3.9 mM) reversibly increased GABA-induced currents through the alpha(1)ss(2)gamma(2L) and the alpha(1)beta(2) GABA(A)R channels. The potentiating effect of N(2)O or Xe on peak currents was prominent at small GABA concentrations (10(-7) to 10(-5) M). The addition of N(2)O or Xe increased the efficacy of GABA (10(-7) to 10(-3) M). Both N(2)O and Xe significantly decreased the risetime((10%-90%)) of the currents elicited by small GABA concentrations. At the concentrations used, neither N(2)O nor Xe had an intrinsic effect. We conclude that, similar to other anesthetics, both N(2)O and Xe increase the efficacy of GABA at the GABA(A)R and enhance inhibitory GABAergic synaptic transmission.     

Metabolism alters the selectivity of angiotensin-(1-7) receptor ligands for angiotensin receptors

The present study examined whether metabolism of the putative angiotensin-(1-7) receptor agonist and antagonist [angiotensin-(1-7) and D-alanine(7) angiotensin-(1-7), respectively] altered their ability to interact with angiotensin AT(1), AT(2), and AT(4) receptor subtypes. Both angiotensin-(1-7) and D-alanine(7) angiotensin-(1-7) competed with low affinity for (125)I-sarcosine(1), isoleucine(8) angiotensin II binding to AT(1) and AT(2) receptors in rat liver and adrenal medulla membranes, respectively, and competed with low affinity for (125)I-angiotensin IV binding to AT(4) receptors in bovine kidney epithelial cell membranes. In vitro renal metabolism of the angiotensin-(1-7) receptor ligands (incubating peptides with rat cortical tissue homogenates) had minimal influence on low-affinity binding to AT(1) and AT(2) receptors, yet caused a significant and dramatic shift toward high-affinity binding for AT(4) receptors. Low-affinity angiotensin II binding to the AT(4) receptor was also shifted toward high-affinity binding following renal metabolism of the peptide. Conversely, angiotensins with high affinity for the AT(4) receptor (e.g., angiotensin IV) were shifted toward low-affinity binding states following peptide metabolism. Incubation of (125)I-angiotensin-(1-7) with rat cortical tissue generated the high-affinity AT(4) receptor ligand (125)I-angiotensin-(3-7), whereas the renal metabolism of (125)I-angiotensin II generated both (125)I-angiotensin-(3-7) and (125)I-angiotensin IV. These results reveal that renal metabolism of angiotensin-(1-7) receptor ligands and angiotensin II yields products that have high affinity for the AT(4) receptor and could potentially contribute to the biologic actions of the parent peptide in the kidney.     

The effect of beta-subunit assembly on function and localization of the colonic H+,K+-ATPase alpha-subunit

BACKGROUND: Previous experiments from our laboratory have demonstrated that HKalpha(2) coimmunoprecipitated with beta(1)-Na(+),K(+)-ATPase. Although HKalpha(2) is expressed abundantly in the apical membrane of distal colon, the demonstration that beta(1) localizes to this same membrane in distal colon has not been demonstrated previously. METHODS: Immunolocalization was performed in distal colon using a polyclonal antibody against HKalpha(2) and a monoclonal antibody against beta(1). RESULTS: The results demonstrate that HKalpha(2) localizes to the apical membrane. Two pools of beta(1)-Na(+),K(+)-ATPase were detected. The first localized to the apical membrane. The second pool was detected in the basolateral membrane when distal colon sections were deglycosylated with glycosidase F. Therefore, our results demonstrate that beta(1) localizes to the apical membrane with HKalpha(2), and supports the view that beta(1) is the physiologic beta-subunit for HKalpha(2). We tested, therefore, the efficiency of the two beta-subunits expressed in distal colon (beta(1) and beta(3)) to support the activity of HKalpha(2). Human embryonic kidney HEK-293 cells were transiently cotransfected with HKalpha(2) plus beta(1) or HKalpha(2) plus beta(3). Subsequently, (86)Rb(+)-uptake and plasma membrane localization were evaluated. The results demonstrate that both HKalpha(2)/beta(1) and HKalpha(2)/beta(3) support (86)Rb(+)-uptake. However, (86)Rb(+)-uptake measured in the cells cotransfected with HKalpha(2) plus beta(1) exceeded that measured in cells expressing HKalpha(2)/beta(3). Fluorescence microscopy using enhanced green fluorescent protein cloned at the amino-terminus of HKalpha(2) demonstrated protein migration to the plasma membrane in cells cotransfected with EGFP-HKalpha(2) plus beta(1). In contrast, in cells cotransfected with EGFP-HKalpha(2) plus beta(3), the vast majority of the protein remained confined to intracellular compartments. The significantly higher (86)Rb(+)-uptake corresponded to additional localization of HKalpha(2) to the plasma membrane when coexpressed with beta(1) compared to beta(3). CONCLUSION: Taken together, these and previous results from our laboratory indicate that beta(1)-Na(+),K(+)-ATPase is likely to represent the most physiologic and efficient subunit for HKalpha(2) assembly in distal colon.