Accuracy and reproducibility of patient-specific hemodynamic models of stented intracranial aneurysms: report on the Virtual Intracranial Stenting Challenge 2011.

Validation studies are prerequisites for computational fluid dynamics (CFD) simulations to be accepted as part of clinical decision-making. This paper reports on the 2011 edition of the Virtual Intracranial Stenting Challenge. The challenge aimed to assess the reproducibility with which research groups can simulate the velocity field in an intracranial aneurysm, both untreated and treated with five different configurations of high-porosity stents. Particle imaging velocimetry (PIV) measurements were obtained to validate the untreated velocity field. Six participants, totaling three CFD solvers, were provided with surface meshes of the vascular geometry and the deployed stent geometries, and flow rate boundary conditions for all inlets and outlets. As output, they were invited to submit an abstract to the 8th International Interdisciplinary Cerebrovascular Symposium 2011 (ICS'11), outlining their methods and giving their interpretation of the performance of each stent configuration. After the challenge, all CFD solutions were collected and analyzed. To quantitatively analyze the data, we calculated the root-mean-square error (RMSE) over uniformly distributed nodes on a plane slicing the main flow jet along its axis and normalized it with the maximum velocity on the slice of the untreated case (NRMSE). Good agreement was found between CFD and PIV with a NRMSE of 7.28%. Excellent agreement was found between CFD solutions, both untreated and treated. The maximum difference between any two groups (along a line perpendicular to the main flow jet) was 4.0 mm/s, i.e. 4.1% of the maximum velocity of the untreated case, and the average NRMSE was 0.47% (range 0.28-1.03%). In conclusion, given geometry and flow rates, research groups can accurately simulate the velocity field inside an intracranial aneurysm-as assessed by comparison with in vitro measurements-and find excellent agreement on the hemodynamic effect of different stent configurations.

Trabecular bone score (TBS) in postmenopausal African American women.

UNLABELLED: Trabecular bone score (TBS) is a newly developed parameter that can be derived from DXA scans of the spine and may reflect bone quality. This study provides TBS values in healthy postmenopausal women of African descent. INTRODUCTION: African American women have a lower risk for osteoporotic fractures as a result of higher bone density and better bone quality. We examined TBS in postmenopausal African American women since there are no previous reports in this population. METHODS: This was a study of healthy African American volunteers using baseline values prior to their participation in two vitamin D intervention studies conducted at an ambulatory research center of an academic health center. RESULTS: The study population consisted of 518 healthy postmenopausal African American women with a mean age of 66 years and a BMI of 30.1. Mean TBS (L1 to L4) was 1.300(.100 SD). Significant negative correlations were found between TBS and age and BMI. None of the biochemical variables were significantly correlated with TBS whereas the various bone density sites were correlated with TBS. CONCLUSION: TBS values for African American women are higher than those reported in the literature for white women and are inversely related to age and BMI.

Anatomía patológica del glomérulo renal en el síndrome nefrótico / Pathology of nephrotic syndrome

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Carcinoma micropapilar de vejiga: presentación de un caso y revisión de la literatura / Micropapillary bladder carcinoma: A case report and a review of the literature

El carcinoma micropapilar de vejiga se define como una variedad de carcinoma transicional con un aspecto histológico similar al carcinoma seroso papilar de ovario y a carcinomas micropapilares de otras localizaciones. Su pronóstico es peor que el del carcinoma urotelial convencional, al mostrar un comportamiento más agresivo y frecuentemente un estadio más avanzado en el momento del diagnostico. Presentamos el caso de un varón de 82 años que fue intervenido de litiasis vesical y adenomectomía suprapúbica. En el momento de la intervención se identificó una lesión polipoidea sésil de 2,5 cm de eje mayor. Microscópicamente se encontraba constituida por una proliferación de grupos compactos de células epiteliales con marcada atipia en espacios lacunares artefactuales, y con una apariencia micropapilar. El tumor se extendía en profundidad infiltrando planos musculares (AU)

Double versus single renal allografts from aged donors.

BACKGROUND: The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient. MATERIAL AND METHODS: In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation. RESULTS: Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05). CONCLUSIONS: Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Membranous glomerulonephritis associated with hepatitis C virus infection in renal transplant patients.

BACKGROUND: Hepatitis C virus (HCV) infection has been described in association with various types of glomerular diseases, usually type I membranoproliferative glomerulonephritis and rarely membranous glomerulonephritis (MGN). In this article, we describe the first series of MGN exhibited in renal transplant patients and associated with HCV infection. METHODS: From January 1980 to December 1994, 2045 kidney transplantations were performed in our renal transplant units. A retrospective analysis demonstrated an overall 20% prevalence of HCV virus-positive patients; 409 transplanted patients were HCV positive (ELISA and RIBA). RESULTS: Fifteen patients developed an allograft MGN (3.66%) 24 months after renal transplantation. MGN appeared in the form of significant proteinuria (>1.5 g/24 h) with stable renal function. In all cases, graft biopsy demonstrated a thickening of the capillary wall, subepithelial electron-dense deposits, and IgG and C3 diffuse granular deposits along the basal membrane. Ten cases were considered de novo, two cases were considered recurrent MGN, and three cases were considered undetermined because the primary renal disease was chronic glomerulonephritis. All patients showed negative antinuclear antibodies and cryoglobulins, normal complement, and negative rheumatoid factors. During follow-up (an average of 2 years), 12 patients developed a progressive worsening of renal function, with increased serum creatinine and persistent proteinuria; 8 of the 12 patients returned to dialysis. Of the remaining three cases, two patients showed partial remission of nephrotic syndrome after high doses of steroids, and one patient persisted with stable renal function and proteinuria (<2 g/24 h.). CONCLUSIONS: In summary, HCV is preferentially associated with MGN in renal transplant patients, rather than with membranoproliferative glomerulonephritis as in the normal adult population. MGN associated with HCV infection has a similar clinical picture and outcome to posttransplant idiopathic de novo MGN, with persistent massive proteinuria and progressive deterioration of renal function.

Recurrent type III membranoproliferative glomerulonephritis after kidney transplantation.

The first well-documented case of recurrent type III membranoproliferative glomerulonephritis after kidney transplantation is reported in this article. A 48-year-old man was admitted to the hospital because of nephrotic syndrome and moderate renal failure. The renal biopsy showed double-contour images at light microscopy. Electron microscopy revealed electron-dense deposits in the mesangium and in both the subepithelial and subendothelial sides of the basement membrane. Subepithelial deposits were sometimes hump-like and produced an irregular disruption of the lamina densa. A diagnosis of type III membranoproliferative glomerulonephritis was suggested. The patient had a rapid decrease in renal function and received dialysis in 3 months. Three years later, he received a cadaveric kidney transplant, and subsequently recovered normal renal function. Proteinuria appeared after 13 months, and a biopsy of the graft demonstrated recurrence of the original disease. Seven years after transplantation, he returned to hemodialysis.

Outcome of silent lupus nephritis.

To analyze the long-term outcome in patients with silent lupus nephritis, we retrospectively studied 20 patients with systemic lupus erythematosus without clinical renal involvement who had renal biopsies in our unit between 1978 and 1986 and reviewed 193 cases reported between 1957 and 1995. Two patients of the current series were lost to follow-up. Mean follow-up in the other 18 was 13 +/- 3 years (range, 2 to 17). On kidney biopsy, nine had class I, six class II, one class IV, and two class V disease (WHO classification). Three patients with prior normal renal function died of nonrenal causes. During the study, the remaining 15 patients had normal renal function and urinalysis. Most patients from the literature had "mild" histologic lesions, but 30 had diffuse proliferative glomerulonephritis. Over an average of 46 months of follow-up from biopsy, renal survival rate and patient survival rate were 98% and 91%, respectively. Three patients died of end-stage renal failure. In conclusion, end-stage renal failure in patients with silent lupus nephritis is rare regardless of the histopathological renal lesions. Patients survival depends on nonrenal causes.

[Granulomatous prostatitis. An infrequent diagnosis. Review of our series]. / La prostatitis granulomatosa. Un diagnóstico infrecuente. Revisión de nuestra serie.

Granulomatous prostatitis is an inflammatory condition of the prostate which presents rarely in the urological practice. It is caused by several specific and unspecific infectious agents, and can also be secondary to prostate surgery or a local reflection of a systemic granulomatous disease. With regard to clinical manifestations and treatment, it is an unspecific entity which has a characteristic histopathology. Its major interest consists on the possibility of it being mistaken for a prostate cancer during physical examination. This paper reviews a series of 7 granulomatous prostatitis, with special emphasis on their histology and ultrasound findings.

Periglomerular granulomatosis. A limited form of Wegener's granulomatosis with exclusive renal involvement?

Three episodes of acute renal failure, all of them requiring hemodialysis, were observed in two patients. The renal biopsy specimens showed a massive periglomerular granulomatosis with crescentic glomerulonephritis. With cyclophosphamide therapy, a dramatic improvement in renal function was observed in both patients. Although the histologic findings and the response to cyclophosphamide therapy were characteristic of Wegener's granulomatosis, there was no evidence of respiratory involvement or extrarenal manifestations throughout the patients' clinical course. We think that these cases could represent limited forms of Wegener's granulomatosis with exclusive renal involvement.

Focal glomerulosclerosis and proteinuria in patients with solitary kidneys.

We have studied ten normotensive patients (nine male and one female, aged between 28 and 51 years) who each had a solitary functioning kidney and proteinuria. Six had undergone unilateral nephrectomy, and four unilateral renal agenesis. In each case, intravenous pyelography revealed only one functioning kidney with compensating hypertrophy. Mild to moderate chronic renal failure was present in six, and microhematuria in two. Proteinuria ranged from 1.10 to 4.10 g/24 hr, being in the nephrotic range in three patients. In seven patients, a renal biopsy showed focal glomerulosclerosis. Immunofluorescence studies demonstrated granular deposits of IgM in three and C3 in six cases, over the sclerotic areas. We suggest that the appearance of proteinuria and focal glomerulosclerosis in a patient with a solitary kidney could be due to chronic glomerular hyperfiltration.

Testicular malacoplakia.

We report the twentieth case in the world literature of testicular malacoplakia. This lesion occurs mainly in middle-aged men, appearing clinically as epididymo-orchitis or enlargement of the testicle with fibrous consistency and some soft areas. Malacoplakia is now considered a nonspecific inflammatory granulomatous lesion subsequent to an infection by gram-negative bacteria. In our case Escherichia coli was cultured in the urine and testicular tissue. The ultrastructural study shows the histiocytic nature of the cellular infiltrate as well as the morphology of Michaelis-Gutmann bodies. Bacilliform structures were not found. The cellular and humoral immunological studies did not show alterations.