3-NITRO-2-PYRIDINESULFENYL (Npys) GROUP

The novel 3-nitro-2-pyridinesulfenyl (Npys) group, which is useful for the protection and the activation of amino and hydroxyl groups for peptide synthesis, is reported. The Npys group is readily introduced by treatment of amino acids with 3-nitro-2-pyridinesulfenyl chloride. The Npys group is easily removed by treatment with very dilute HCl, e.g. 0.1-0.2 N HCl in dioxane, but it is resistant to trifluoroacetic acid and 88% formic acid. Npys is also selectively removed under neutral conditions using triphenylphosphine or 2-pyridinethiol 1-oxide without affecting benzyloxycarbonyl (Z), tert-butyloxycarbonyl (Boc), 2-(4-biphenylyl) propyl(2) oxycarbonyl (Bpoc), 9-fluorenylmethyloxycarbonyl (Fmoc), benzyl (Bzl) or tert-butyl (tBu) protecting groups. The N-Npys and O-Npys groups when activated in the presence of RCOOH by the addition of tertiary phosphine form peptide or ester bonds via oxidation-reduction condensation. The important features of the Npys group are demonstrated through the synthesis of peptides in solution and by solid phase methodology without a formal deprotection procedure. In solid phase synthesis, 4-(Npys-oxymethyl) phenylacetic acid is used as the key intermediate for the introduction of the trifluoroacetic acid resistant 4-(oxymethyl) phenylacetamido linking group to the resin.     

COLOR DOPPLER ULTRASOUND ASSESSMENT OF URETHRAL ARTERY LOCATION: POTENTIAL IMPLICATION FOR TECHNIQUE OF VISUAL INTERNAL URETHROTOMY

Purpose

We assessed the location of urethral arteries in patients with urethral stricture using color Doppler ultrasound.

Materials and Methods

We performed 41 color ultrasound studies of the urethra in 33 patients 17 to 76 years old. The linear array transducer was placed on the ventral surface of the penis and perineum to image the urethra and periurethral structures. In addition of evaluating the extent of stricture disease, color Doppler ultrasound determined the location of the urethral arteries at the segment with stricture.

Results

The number and site of the urethral arteries vary among individuals. Contrary to the common belief that these arteries are located at the 3 and 9 o'clock positions, we have found that in the bulbous urethra the arteries are at the 1 to 2 o'clock positions in 14% of cases, 3 to 4 in 22%, 5 to 6 in 17%, 7 to 8 in 18%, 9 to 10 in 18% and 11 to 12 in 11%. The arteries may be close to the surface of the urethral lumen, especially in patients who have undergone previous urethral procedures. Preoperative evaluation of urethral artery location may be helpful for preventing arterial bleeding at visual internal urethrotomy.

Conclusions

Color Doppler ultrasound can effectively assess the extent of stricture disease and urethral artery sites. Because the location of the urethral arteries varies among patients, individual preoperative assessment is advisable. Color Doppler ultrasound is currently our imaging method of choice for evaluating strictures of the pendulous and bulbous urethra.     

Metanephric Adenoma Treated with Laparoscopic Nephrectomy

A 31-year-old-female presented with a left renal mass detected incidentally during an abdominal ultrasound examination. Computed tomography and angiography revealed a hypovascular solid tumor 4.5 cm in diameter at the middle portion of the left kidney. Laparoscopic left nephrectomy was performed and macroscopic examination of the specimen revealed encapsulated tumor with grayish yellow cut surface. Histological examination demonstrated that the tumor cells were small scant cytoplasms, containing round and regular nuclei, forming a glomerular-like structure. There was no mitosis nor cellular atypia indicating a malignant structure. The histological diagnosis was metanephric adenoma.     

Preparation of Boc-[S-(3-nitro-2-pyridinesulfenyl)]-cysteine and its use for unsymmetrical disulfide bond formation

The 3-nitro-2-pyridinesulfenyl (Npys) derivative of cysteine was prepared and used to facilitate the formation of an unsymmetrical disulfide bond. Since this derivative is stable in trifluoroacetic acid:CH₂Cl₂ (1:1) and anhydrous hydrogen fluoride, Boc-Cys(Npys) could be used directly in solid phase synthesis of the 14-peptide acetyl-Cys(Npys)-Gly-Glu-Gln-His-His-Pro-Gly-Gly-Gly-Ala-Lys-Gln-Ala-amide. Reaction of this peptide with the free thiol of another peptide, acetyl-Gly-Glu-Gln-His-His-Pro-Gly-Gly-Gly-Ala-Lys-Gln-Cys-amide, gave a single product containing an unsymmetrical disulfide bond. The amino acid composition of this product and HPLC analysis of its dithiothreitol reduction products were consistent with the desired heterodimer. As evidenced by HPLC, the mixed disulfide forms rapidly at alkaline pH and usefully over a wide pH range in aqueous buffers.     

Structure and correlates of alcohol dependence in clinical samples in the United States and Russia

Using items from the Composite International Diagnostic Interview, dimensionality of the alcohol dependence syndrome was assessed in clinical samples in the United States and Russia. In both groups, a single-factor model provided a high degree of goodness of fit thus demonstrating cross-cultural coherence of the construct. The item dealing with narrowing of the drinking repertoire is most disparate in each sample. Seventy of alcohol consequences was moderately related to alcohol dependence in both samples. Demographic variables, however, correlated less with severity of consequences. After the effects of severity of dependence and demographics were removed, quantity/frequency of recent alcohol consumption did not contribute to severity of consequences. Country, however, remained a significant, but small, predictor of severity of alcohol consequences.     

部分喉切除术治疗喉癌的远期疗效观察

目的：总结１９８０年１０月至１９９７年１０月间６３例不同部位的喉癌手术治疗经验。方法：采用不同术式行部分喉切除术，其中行喉裂开声带切除１９例。垂直半喉切除３７例，水平半喉切除７例，４例做了功能性颈廓清术。术皇４４例辅以放疗。结果：３年、５年生存率分别８１．８％、７９．１％，发音及吞咽功能均恢复，拔管率达９２％。结论：认为掌握手术指征，充分了解肿瘤侵犯的范围是部分喉切除成功的关键。     

新工艺金芪降糖片对大鼠胰岛细胞的保护作用

【目的】研究新工艺金芪降糖片对大鼠胰岛细胞细胞生长活性和胰岛素分泌的影响。【方法】提取大鼠胰岛细胞并建立稳定的原代细胞培养方法,将培养状态良好的细胞随机分为正常对照组、模型组、格列本脲组及新工艺金芪降糖片高、中、低剂量组,观察高、中、低剂量新工艺金芪降糖片（10、1.0、0.1μg生药/ml）,对体外葡萄糖诱导大鼠胰岛细胞分泌胰岛素、链脲佐菌素损伤胰岛细胞活性及高糖诱导胰岛细胞凋亡的影响。【结果】与模型组比较,新工艺金芪降糖片可以改善胰岛细胞分泌胰岛素的功能（P〈0.05）,减轻链脲佐菌素对胰岛细胞的损伤作用（P〈0.05）,降低高糖诱导胰岛细胞的凋亡百分率（P〈0.05）。【结论】新工艺金芪降糖片可促进胰岛细胞分泌胰岛素,且对胰岛细胞具有一定的保护作用。     

CB1受体通过钾离子通道介导外周镇痛作用

目的:探究大麻素1型受体(CB1受体)在外周的镇痛机制。方法:建立坐骨神经慢性压迫性损伤(CCI)小鼠模型,测量机械触诱发痛和热敏痛阈值观察痛行为变化,采用Western blot检测CB1受体的动态变化,记录坐骨神经单纤维放电频率以探究CB1受体激活是否受到钾通道的调节。结果:伴随着疼痛阈值的降低,小鼠坐骨神经损伤区CB1受体表达升高。外周损伤区注射CB1受体特异性激动剂HU210具有显著的镇痛作用,但预先20 min注射CB1受体特异性拮抗剂AM281或钾通道非特异性阻断剂四乙铵(TEA)之后再注射HU210,其镇痛作用消失。在损伤区灌流槽中加入HU210能够明显使起步点自发电的频率降低,但是提前加入AM281或TEA均能阻碍这个作用。结论:CB1受体在外周的镇痛作用是通过钾通道介导的。     

登革病毒Ⅱ型对人脐静脉血管内皮细胞通透性的研究

目的 研究登革病毒Ⅱ型(DENV-2)对人脐静脉血管内皮细胞(HUVEC)通透性的影响.方法 DENV-2病毒滴定,DENV-2接种HUVEC单层细胞,用间接免疫荧光法动态观察DENV-2感染HUVEC的情况(30 min,l、3、6、12、24、30、36、42、48、72 h),实时定量荧光PCR方法检测病毒载量,transwell法检测DENV-2对HUVEC通透性的影响,透射电镜观察细胞超微结构的改变.结果 DENV-2对HUVEC通透性的影响30 min时作用最为明显,其次为42 h时.且病毒载量与HUVEC通透性改变呈正相关.透射电镜结果显示有细胞微绒毛脱落,胞质溶解,部分核膜间隙增宽,甚至是细胞核中也存在裂隙,部分线粒体嵴消失甚至空化,线粒体髓样变,包膜不完整.结论 DENV-2对HUVEC通透性有影响,为探究登革病毒的发病机制提供一定的理论依据.

Abstract：

Objective To research Dengue virus type 2 (DENV-2) to human umbilical vein endothelial cells (HUVEC) permeability. Methods The titration of DENV-2 was detected and HUVEC infection DENV-2 layer of cells. At different time points after infection (30 min, 1 h, 3 h, 6 h, 12 h, 30 h,36 h, 24 h, 42 h, 48 h,72 h), the permeability in HUVEC were detected after Dengue virus infection. The virus load in HUVEC was detected by quantitative real-time PCR. And ultrastructure in HUVEC was observed by electron microscope. Results The permeability in HUVEC was changed after Dengue virus infection by time lasting. The most permeability in HUVEC was changed after Dengue virus infection at 30 min and 42 h. And at the same time the virus load were most value in all of time. The results of the cell membrane were changed by electron microscope. The deciduous cell microvillus and dissd endochylema were founded. And some of nuclear membrane blank was wided by Dengue virus. Even the leakage was founded in cell nucleus. The other change included that disappearance mitochondrial and vacuolization crista, elder pith change mitochondria. In addition, the complete of cell membrane were dissolved. Conclusion The permeability of HUVEC was changed by DENV-2. To explore the pathogenesis of Dengue virus provide certain theoretical basis.