Nonpalpable cancer of the prostate: assessment with transrectal US

Palpable cancer of the prostate is widely believed to be clinically significant. The authors compared the clinical significance of palpable prostate cancer with nonpalpable prostate cancer discovered with transrectal ultrasound (US). A strong association between lesion volume measured with preoperative transrectal US and volumetric measurements in 60 radical prostatectomy specimens permitted the use of tumor size measured with transrectal US as a reasonable estimation of gross tumor volume. In a subsequent clinical series, 147 biopsy-proved cancers were grouped according to size measured at US, the findings at digital rectal examination (DRE), and the Gleason score. For the 147 patients with known prostate cancer, a statistically significant difference between Gleason scores of palpable and nonpalpable cancers could not be demonstrated when the size of the tumor and its location within the prostate were held constant. Assuming that the Gleason score is a reliable indication of malignant potential and clinical significance, the authors conclude that nonpalpable prostatic cancer detected with transrectal US alone may be just as clinically significant as prostatic cancer discovered with DRE.     

Intravenous pyelography: the case against its routine use

PURPOSE: To critically appraise four common uses of intravenous pyelography in adults. DATA IDENTIFICATION: We reviewed the literature on the use of intravenous pyelography for four clinical indications. STUDY SELECTION: We analyzed the literature to determine the proportion of intravenous pyelograms producing clinically useful information (yield) in four clinical situations. The best estimate of its accuracy (sensitivity and specificity) for associated pathologic findings was determined. The implications of using the test on the outcomes of patients and costs were evaluated. RESULTS OF DATA SYNTHESIS: The yield of significant abnormalities in patients having prostatectomy is small; intravenous pyelography does not specifically indicate ureteral obstruction, and is not sensitive or specific enough for screening for urinary tract malignancies. Many false-positive results, little benefit, and significant costs can be expected. When used before hysterectomy, intravenous pyelography does not reduce injury to the ureters, and the yield of unexpected abnormalities is small. The use of the test to screen for unexpected anatomic abnormalities in adult women after urinary tract infections has not led to improved outcomes or prevention of impaired renal function. Acquired causes of obstruction will be suggested by the history or physical examination. In hypertensive adults, intravenous pyelography is not accurate enough in detecting renal artery stenosis or in predicting favorable outcomes of renal artery surgery. Also, large costs are generated by high false-positive rates, and candidates for successful surgery are not reliably identified. CONCLUSIONS: Selective use of intravenous pyelography is recommended for patients before prostatectomy or hysterectomy, in women after urinary tract infections, and in adults whose hypertension may have a renovascular cause. Use should be reserved for patients whose history and physical examination raise specific questions for which this test could provide an answer that would affect treatment.     

Comparison of mechanical and electrical activity and interstitial cells of Cajal in urinary bladders from wild-type and W/Wv mice

Background and purpose:

W/W^v and wild-type murine bladders were studied to determine whether the W/W^v phenotype, which causes a reduction in, but not abolition of, tyrosine kinase activity, is a useful tool to study the function of bladder interstitial cells of Cajal (ICC).

Experimental approach:

Immunohistochemistry, tension recordings and microelectrode recordings of membrane potential were performed on wild-type and mutant bladders.

Key results:

Wild-type and W/W^v detrusors contained c-Kit- and vimentin-immunopositive cells in comparable quantities, distribution and morphology. Electrical field stimulation evoked tetrodotoxin-sensitive contractions in wild-type and W/W^v detrusor strips. Atropine reduced wild-type responses by 50% whereas a 25% reduction occurred in W/W^v strips. The atropine-insensitive component was blocked by pyridoxal-5-phosphate-6-azophenyl-2′,4′-disulphonic acid in both tissue types. Wild-type and W/W^v detrusors had similar resting membrane potentials of −48 mV. Spontaneous electrical activity in both tissue types comprised action potentials and unitary potentials. Action potentials were nifedipine-sensitive whereas unitary potentials were not. Excitatory junction potentials were evoked by single pulses in both tissues. These were reduced by atropine in wild-type tissues but not in W/W^v preparations. The atropine-insensitive component was abolished by pyridoxal-5-phosphate-6-azophenyl-2′,4′-disulphonic acid in both preparations.

Conclusions and implications:

Bladders from W/W^v mice contain c-Kit- and vimentin-immunopositive ICC. There are similarities in the electrical and contractile properties of W/W^v and wild-type detrusors. However, significant differences were found in the pharmacology of the responses to neurogenic stimulation with an apparent up-regulation of the purinergic component. These findings indicate that the W/W^v strain may not be the best model to study ICC function in the bladder.     

人脂肪组织来源干细胞在心脏疾病治疗中的应用

目的:综述人脂肪组织来源干细胞的生物学特性及其在缺血性心脏病中的应用,分析不足,并在此基础上提出未来研究要解决的问题,以期为临床治疗提供依据。资料来源:应用计算机检索Blackwell、Elsevier、Pubmed数据库1980/2007期间脂肪源性干细胞与缺血性心脏病方面的文献,检索词为“bone mesenchymal stem cells,adipose derived stemcells,cardiomyocytes,ischemic heart disease”等。应用计算机检索中国期刊全文数据库1980/2007期间相关文献,检索词为“骨髓间充质干细胞,脂肪组织来源的干细胞,心肌细胞,缺血性心脏病”等。并手工查阅相关书籍。资料选择:对资料进行初步选择:①脂肪组织来源干细胞的生物学特性。②脂肪组织来源干细胞治疗缺血性心脏病。排除重复文献。资料提炼:共搜集到相关文章57篇,删除内容重复及与本文主题关系较远的文章,剩余41篇作为综述参考。资料综合:脂肪组织来源干细胞与同样起源于中胚层的骨髓基质细胞不仅具有非常相似的生物学特性,而且在细胞表面标志谱的表达方面也非常相近。并且脂肪组织来源广泛,取材方便,可获得的基质细胞数量大,易于培养扩增。有研究发现,脂肪组织来源干细胞体外培养不需要任何诱导便能分化成具有自律性的心肌细胞,使得脂肪组织来源干细胞治疗缺血性心脏病成为可能。结论:脂肪组织来源干细胞在取材和增殖方面较骨髓间充质干细胞有优势;脂肪组织来源干细胞能较好的诱导为心肌细胞,将为缺血性心脏病的治疗提供更广阔的前景。     

A new combined in-vitro test model for the identification of substances affecting essential sperm functions [published erratum appears in Hum Reprod 1997 Nov;12(11):2580]

Binding of mammalian spermatozoa to the zona pellucida and the induction of the acrosome reaction are prerequisites for successful oocyte fertilization. It has been postulated that xenobiotics that are released in the environment as well as exposure to pharmaceutical medications may be associated with reproductive problems in men and wildlife. Examining physiological and non-physiological effects of particular compounds on sperm functions requires high quality in-vitro test systems. We established a reliable combined in-vitro test system with bovine gametes and evaluated if aliquots of pooled post-thaw spermatozoa are suitable for examining essential sperm functions. Using cryopreserved semen, the PSA-FITC/Hoechst 33258 staining procedure was applicable to evaluate the acrosomal status and cell viability. In the bovine hemizona assay, hemizona indices revealed no differences between cryopreserved and fresh semen. Treatment of post-thaw bovine spermatozoa with progesterone (1 microM or bovine follicular fluid (20%) induced the acrosome reaction from 12% (untreated spermatozoa) to 25% (P < 0.001) and to 22% [corrected] (P < 0.01), respectively. Incubation of both compounds (1 microM progesterone and 20% follicular fluid) raised the percentage of acrosome-reacted spermatozoa to 30% (P < 0001). Our results demonstrate that cryopreserved semen can be integrated into an in-vitro screening model for reproductive toxicology testing. Pooled, cryopreserved bovine spermatozoa will thus permit reproducible experiments for clinical and basic science purposes and may also be applicable for the human system.