Magnetic resonance imaging of urea transporter knockout mice shows renal pelvic abnormalities

Many transgenic and knockout mice with increased urine flow have structural abnormalities of the renal pelvis and inner medulla. Here, we used high resolution contrast enhanced T1-weighted magnetic resonance imaging of mice whose urea transporters UT-A1 and UT-A3 were deleted (UT-A1/3(-/-) mice) as a model for the in vivo study of such abnormalities. Three distinct variations in the appearance of the renal pelvis were found. These included normal kidneys with no accumulation of contrast agent in the renal pelvis; infrequent frank right-sided unilateral hydronephrosis with marked atrophy of the renal medulla; and a renal pelvic reflux pattern characterized by the presence of contrast agent in the renal pelvis surrounding the renal inner medulla but no substantial atrophy of the medulla. This last pattern was found in most of the advanced age UT-A1/3(-/-) mice and in aquaporin-1 knockout mice. The UT-A1/3(-/-) mice also had increased mean arterial blood pressures. Feeding the mice a low protein diet did not prevent development of their renal pelvic abnormalities. Our studies show that real time imaging of renal pelvic structure in genetically manipulated mice provides a tool for the non-destructive, temporal evaluation of kidney structure.     

Trabecular (Merkel cell) carcinoma of the skin. A case report.

A case of trabecular (Merkel cell) carcinoma of the skin is reported. The lesion appeared on the back, recurred locally twice and metastasized to the intra-abdominal lymph nodes 7 years later. Its unusual primary site, as well as the development of prostatic adenocarcinoma are the main characteristics of the case presented.     

Promotion by polychlorinated biphenyls of lung and liver tumors in mice

Polychlorinated biphenyls (PCB), which are tumor promoters,have been found in human tissues for decades. Their contributionto cancer risk may only now start to appear, due to long humancancer latency and the nature of tumor promotion. Epidemiologicalassociations have been seen between PCB exposure or tissue contentand cancer at several sites. In rodents, tumor promotion byPCBs has been little studied in tissues other than liver. Previously,in an experiment modeling infant carcinogen exposure followingPCBs received in milk, lung and liver tumors, initiated neonatallyin mice by the environmental nitrosamine N-nitrosodimethylamine(NDMA), were promoted by later treatment with Aroclor 1254.The present study was undertaken to confirm and characterizethe effects of Aroclor 1254 on tumor number, latency, size andmalignancy. Male Swiss mice were given NDMA on postnatal day4 and Aroclor 1254 (250 mg/kg) on day 8, and killed at intervals.Eight PCB congeners were quantified in the carcasses. Incidencesof mice with NDMA-initiated lung tumors at 28 weeks of age wereincreased 2.5-fold by PCBs. Multiplicities of lung tumors wereenhanced four-fold by PCBs at 28 and 52 weeks. By 72 weeks tumornumbers were similar in the NDMA-only and NDMA–PCB groups.Liver tumors first occurred in significant numbers at 52 weeksand only in mice receiving both NDMA and PCBs. As for the lung,at 72 weeks the incidence was high in both the NDMA-only andNDMA–PCB groups. Sizes of tumors and liver carcinoma incidencewere not altered by PCB treatment. Carcass analysis revealeda significant positive association between lung tumor numbersat 28 weeks and relative percentage of 2,2',4,4',5-pentachlorobiphenyl,with no other correlations. The results confirm that PCBs promotelung as well as liver tumors, by triggering the early appearanceof latent initiated tumors otherwise presenting in old age.     

Surgical Techniques and Treatment for Hepatic Hydatid Cysts

Purpose Hepatic hydatid cysts (HHCs) are a parasitic infestation caused by several species of Echinococcus. We examined the clinical features of HHCs and evaluated the results of various surgical procedures. Methods One hundred and sixty-nine patients aged between 17 and 84 years underwent surgery for HHCs within a 12-year period. We recorded the demographic data, location of the cysts, surgical procedures used, morbidity, recurrences, and hospital stay. Results Most (90.5%) of the patients presented with symptoms, but 16 (9.5%) patients reported no symptoms. The most common symptom was abdominal pain. The overall number of cysts was 216 HHCs and 9 concomitant hydatid cysts in other abdominal organs. The surgical treatments consisted of hepatic resection in 8 (4.7%) patients, cystostomy with drainage in 43 (25.5%), cystostomy with capitonnage in 22 (13%), cystostomy with omentoplasty in 72 (42.6%), and cystectomy in 24 (14.2%). Splenectomy or nephrectomy was also performed in nine patients. Postoperative complications developed in 36 (21.3%) patients, and three suffered recurrences. The postoperative mortality rate was 1.2%. Postoperative complications were more frequent after cystostomy with capitonnage than after cystostomy with omentoplasty (P < 0.001) or cystectomy (P = 0.0037). The additional procedures prolonged the hospital stay. Conclusions Current surgical techniques combined with antiscolicidal therapy using albendazole are effective and safe treatments for HHCs, associated with low morbidity, mortality, and recurrence rates.     

Automatic assessment of dynamic contrast-enhanced MRI in an ischemic rat hindlimb model: an exploratory study of transplanted multipotent progenitor cells

This study presents computerized automatic image analysis for quantitatively evaluating dynamic contrast-enhanced MRI in an ischemic rat hindlimb model. MRI at 7 T was performed on animals in a blinded placebo-controlled experiment comparing multipotent adult progenitor cell-derived progenitor cell (MDPC)-treated, phosphate buffered saline (PBS)-injected, and sham-operated rats. Ischemic and non-ischemic limb regions of interest were automatically segmented from time-series images for detecting changes in perfusion and late enhancement. In correlation analysis of the time-signal intensity histograms, the MDPC-treated limbs correlated well with their corresponding non-ischemic limbs. However, the correlation coefficient of the PBS control group was significantly lower than that of the MDPC-treated and sham-operated groups. In semi-quantitative parametric maps of contrast enhancement, there was no significant difference in hypo-enhanced area between the MDPC and PBS groups at early perfusion-dependent time frames. However, the late-enhancement area was significantly larger in the PBS than the MDPC group. The results of this exploratory study show that MDPC-treated rats could be objectively distinguished from PBS controls. The differences were primarily determined by late contrast enhancement of PBS-treated limbs. These computerized methods appear promising for assessing perfusion and late enhancement in dynamic contrast-enhanced MRI.