Experimental tests of three-dimensional model of urinary concentrating mechanism.

Recently, a new model of the urinary concentrating process has been proposed that takes into account the three-dimensional architecture of the renal medulla. Under the assumptions of the model, computer simulations predicted significant axial osmolality gradients in the inner medulla without active transport by the inner medullary loop of Henle. Two of the model assumptions (which constitute hypotheses for this study) were: (1) the osmotic water permeability of the initial part of the inner medullary collecting duct (initial IMCD) is very low even in the presence of vasopressin; and (2) there is significant lateral separation of structures such that thin descending limbs are far from the collecting ducts at the same inner medullary level. The first hypothesis was addressed by perfusing rat initial IMCD segments in vitro and measuring osmotic water permeability. With the osmotic gradient oriented as predicted by the model (lumen greater than bath), vasopressin increased the osmotic water permeability from 286 to 852 microns/s. Three additional series of experiments confirmed the high water permeability in the presence of vasopressin. The second hypothesis was addressed by morphometric analysis of histologic cross-sections of the rat renal medulla. Mean distances of descending limbs to the nearest adjacent collecting duct were very small throughout the inner medulla (less than 6 microns) and substantially less than in the outer medulla (28 microns). It was concluded that the data are inconsistent with both hypotheses and therefore do not support the feasibility of the "three-dimensional" model of the renal inner medulla. The axial distributions of loops of Henle and collecting ducts in the rat renal medulla are also reported.     

Recent status of the treatment of stress urinary incontinence

The therapeutic options for management of stress urinary incontinence can be conservative, pharmacological or surgical. The treatment of patients with stress urinary incontinence should be tailored to the individual to optimize care. A multitude of surgical techniques have emerged to treat this condition in recent years. The objective of the present review was to present an overview of current practice in the management of stress urinary incontinence while considering the evidence supporting the clinical effectiveness of these procedures.     

Leukoplakia of the urinary tract: a review.

We herein describe 44 new cases of leukoplakia of the renal pelvis, bladder and urethra. Leukoplakia is uncommon. It occurs twice as often in the bladder as in the pelvis and ureter and it is associated with and perhaps caused by chronic infection. Carcinoma is present in 10 to 20 per cent of the cases at diagnosis. We believe that leukoplakia is not simple squamous metaplasia but a step further down the line--a process that evolved through squamous metaplasia and perhaps could result in cancer. We think leukoplakia is potentially pre-malignant and it should be treated as a low grade and low stage tumor since no satisfactory treatment exists.     

Obturator hernia: report of a case and brief review of its status.

The only case of obturator hernia in over 230,000 admissions is discussed. In the review of the recent English literature, a total of 30 cases, including our own, was collected. Characteristics of the condition were analyzed. The median age of the patients was 67 years; the majority were females in a ratio of 9:1 and both sides were equally affected. This entity occurs with the signs and symptoms of small bowel obstruction and, in almost one half of the patients, the pathognomonic Howship-Romberg sign.     

Cycles and separations: the histotopography of the urinary concentrating process

We have analyzed the histotopography of the renal medulla of the rat in terms of cycles and separations. Cycles are pathways by which solute leaving the medulla in an ascending structure (AVR, AHL) is returned to a deeper medullary level. Separations are based on spatial incontiguity and special characteristics of the interstitium and blood supply. The two concepts are complementary: the compartmentalization resulting from separations imparts specificity to the cycles. Structural lateral heterogeneity, consisting in distinct domains organized around vascular bundles, is present in one form or another in all three medullary zones. Such compartmentalization probably leads to heterogeneity in interstitial solute concentrations, a state of affairs inconsistent with the requirements of a "central core". In all such considerations of exchanges between compartments, the lack of a unitary interstitium must be borne in mind. Instead, three general types of interstitium may be distinguished: corresponding roughly to those of the OS and VB, the interbundle region of the IS, and the IM. Among the histotopographic features of the renal medulla not usually included in models of the urinary concentrating mechanism but likely to have functional significance are the association of CD with completely distinct populations of AVR and AHL in the OM and IM; a clear-cut separation throughout the medulla between cycles involving long loops and those involving short loops; the lack of an effective countercurrent association between ascending and descending limbs of short loops in the IS; and a pronounced separation of the venous drainage of the IM from that of the OM.     

Micropapillary carcinoma of the urinary bladder: a case report and review of the literature

Micropapillary carcinoma is an uncommon variant of urothelial carcinoma with high metastatic potential. The presence of micropapillary carcinoma component in bladder biopsies should alert urologists to its aggressive behaviour. We report the case of a 70-year-old man who presented with macroscopic hematuria lasting 2 weeks. Magnetic resonance imaging revealed a bladder tumour in the dome area extended to perivascular adipose. The transurethral biopsy showed a high-grade micropapillary carcinoma with muscle invasion. Radical cystectomy with lymph node dissection was then performed. The pathological examination revealed a high-grade purely micropapillary carcinoma invading the perivesical adipose. No tumour recurrence or metastasis were reported at the 6-month follow-up.     

膀胱原发性恶性黑色素瘤1例并文献复习

目的 观察原发性恶性黑色素瘤的病理形态、免疫组化和电镜特征,进一步探讨其组织起源和鉴别诊断,指导临床诊治.方法 用组织病理学、免疫组化、透射电镜方法进行观察,并结合国外文献资料进行探讨.结果 肿瘤位于膀胱黏膜下,瘤细胞呈巢状或弥漫排列,具有一定异型性,部分为透亮型,部分为小细胞型,靠近边缘的肿瘤细胞呈梭形伴黑色素沉着....     

膀胱副神经节瘤二例报告及文献复习

目的探讨膀胱副神经节瘤的临床病理特征及其诊治方法。 方法回顾性分析2例膀胱副神经节瘤患者的临床资料,分析该病的临床病理特征、诊断及治疗方法,并对相关文献进行回顾和总结。 结果病例1为无功能性肿瘤,体检发现膀胱占位,CT增强扫描明显强化,肿瘤为单发,行经尿道膀胱肿瘤电切术。病例2为功能性肿瘤,主要临床表现为头痛、心悸、排尿后血压一过性升高,MRI增强结节不均匀强化,肿瘤为单发,术前降压扩容后行腹腔镜膀胱部分切除术,术后症状消失。术后病理诊断均为膀胱副神经节瘤。随访9~12个月,均无复发或转移。 结论膀胱副神经节瘤临床罕见,可分为功能性和非功能性,术前需充分检查及准备,术中预防血压波动引起的高血压危象,经尿道膀胱肿瘤电切术及腹腔镜膀胱部分切除术均效果良好,术后需密切随访。     

Paraganglioma of the urinary bladder: A case report and review of the Japanese literature.

We describe a patient with primary paraganglioma of the urinary bladder associated with typical clinical symptoms. Systolic blood pressure frequently increased to 300 mm Hg immediately after micturition. Levels of urinary vanillylmandelic acid excretion and serum norepinephrine were significantly elevated. The tumor was removed by partial cystectomy. Histological examination of the tumor revealed paraganglioma of the urinary bladder. Compared with a review of 53 similar cases reported in Japan, the distribution of age, sex and tumor location in the bladder differed from those described worldwide.     

膀胱炎性肌纤维母细胞瘤一例报告并文献复习

目的探讨膀胱炎性肌纤维母细胞瘤的临床、病理、组织化学特性和诊治方法及预后。方法总结1例膀胱炎性肌纤维母细胞瘤患者的临床资料。患者,男,54岁,肉眼血尿10 d入院。盆腔B超及CT增强扫描示膀胱前壁占位性病变。膀胱镜检可见顶壁4 cm×4 cm×5 cm肿物,表面缺血呈暗红色,病理活检疑为膀胱尿路上皮恶性肿瘤。结果行膀胱部分切除术。组织学表现为增生的梭形或长梭形肿瘤细胞囊状分布,间质小血管增生,伴淋巴细胞、嗜酸性粒细胞及浆细胞浸润,诊断为膀胱炎性肌纤维母细胞瘤。免疫组织化学染色结果为瘤细胞平滑肌特异性肌动蛋白（＋）、波形蛋白（＋）、间变性淋巴瘤激酶（＋）。随访6个月,患者无瘤存活。结论膀胱炎性肌纤维母细胞瘤确诊依据病理学检查,应与横纹肌肉瘤、梭形细胞肉瘤等鉴别,治疗以膀胱部分切除或经尿道切除为主。     

Clinical status of Sagliker syndrome: a case report and literature review

In a 53-year-old woman, Sagliker syndrome developed during 22 years of treatment with intermittent hemodialysis as a result of severe secondary hyperparathyroidism (SHPT) complicating end-stage renal disease. She failed medical managements and lost her renal graft just after the kidney transplantation due to acute rejection. Although surgical parathyroidectomy was effective, the parathyroid hormone level became extremely high again due to recurrent hyperparathyroidism. It is possible that such patient could survive long-term with dialysis, but prevention of severe SHPT is the most important.     

Bifocal disruption of the knee extensor mechanism: a case report and literature review

Bifocal disruption of the knee extensor mechanism is a rare injury. Bifocal proximal and distal avulsion fracture of the patella tendon is extremely rare in adults. Here, the authors report the case of an 84-year-old male patient who developed simultaneous avulsion fracture of the patella tendon from the inferior pole of the patella and the tibial tuberosity. Open reduction and internal fixation were performed, and at 12 months postoperatively, an excellent functional result was obtained.