Development of an animal model to study congenital urinary obstruction.

PURPOSE: We outline the development of a reliable model of obstructive uropathy in fetal lambs highlighting our understanding of the critical time points for interventions and the variability of any such model. We identify some discoveries that may have clinical implications. METHODS: The model requires 60-day-gestation fetal lambs. In lambs, glomerulogenesis is complete by 90 days gestation. (Term is 145 days.) The ability to develop a reliable method of creating bladder outlet obstruction in females, ligating both the urethra and urachus was critical. The lambs are bred to an accuracy of ±24 h. RESULTS: Creating the model at 50-60 days gestation, produces different expressions of renal dysplasia in groups of lambs undergoing identical interventions at the same stage of gestation. Early complete urethral obstruction can produce the Potter phenotype. An appropriately timed vesico-amniotic shunt preserves renal development, producing a shrunken, non-compliant bladder. Shunting the normal fetal bladder at 80 days gestation produces a similar bladder. Provision of a low-pressure valve in the shunt preserves bladder development and compliance. Using a high-pressure shunt produces results similar to non-shunted lambs. DISCUSSION: We developed a reliable animal model for obstructive uropathy. Being alert to peripheral results can lead to new findings.

Double-balloon endoscopy versus magnet-imaging enhanced colonoscopy for difficult colonoscopies, a randomized study.

BACKGROUND AND STUDY AIMS: Studies have estimated that failure of cecal intubation occurs with conventional colonoscopy in up to 10 % of cases. Double-balloon endoscopy (DBE) systems, magnetic endoscope imaging (MEI), and transparent cap have been shown to improve success rates for colonoscopy. This study evaluated the utility of DBE for complete examination of the colon compared with MEI plus cap (MEI-Cap) after incomplete or technically difficult colonoscopy in a randomized comparative manner. PATIENTS AND METHODS: A total of 94 patients with incomplete or technically difficult colonoscopy were randomly assigned to receive either DBE (n = 47) or colonoscopy with MEI-Cap (n = 47). The primary end point was cecal intubation rate within 30 minutes. Secondary end points included intubation time, pain score using a visual analog scale, abdominal pressure attempts, doses of sedative medication, and changes in patient position during colonoscopy. RESULTS: Patient characteristics were comparable in both groups. Cecal intubation rate within 30 minutes was significantly higher for DBE (45 /47, 95.7 %) than for MEI-Cap (34 /47, 72.3 %) (P = 0.0049). Mean time to reach the cecum was significantly lower in the DBE group (13.0 ±â€Š5.3 minutes) than in the MEI-Cap group (16.4 ±â€Š4.8 minutes; P = 0.0003). No complications were encountered in either group.   CONCLUSION: DBE is more useful for complete examination of the colon than MEI-Cap in patients with incomplete or technically difficult colonoscopy.

Inhibition of T helper cell type 2 cell differentiation and immunoglobulin E response by ligand-activated Valpha14 natural killer T cells.

Murine Valpha14 natural killer T (NKT) cells are thought to play a crucial role in various immune responses, including infectious, allergic, and autoimmune diseases. Because Valpha14 NKT cells produce large amounts of both interleukin (IL)-4 and interferon (IFN)-gamma upon in vivo stimulation with a specific ligand, alpha-galactosylceramide (alpha-GalCer), or after treatment with anti-CD3 antibody, a regulatory role on helper T (Th) cell differentiation has been proposed for these cells. However, the identity of the cytokine produced by Valpha14 NKT cells that play a dominant role on the Th cell differentiation still remains controversial. Here, we demonstrate by using Valpha14 NKT-deficient mice that Valpha14 NKT cells are dispensable for the induction of antigen-specific immunoglobulin (Ig)E responses induced by ovalbumin immunization or Nippostrongylus brasiliensis infection. However, upon in vivo activation with alpha-GalCer, Valpha14 NKT cells are found to suppress antigen-specific IgE production. The suppression appeared to be IgE specific, and was not detected in either Valpha14 NKT- or IFN-gamma-deficient mice. Consistent with these results, we also found that ligand-activated Valpha14 NKT cells inhibited Th2 cell differentiation in an in vitro induction culture system. Thus, it is likely that activated Valpha14 NKT cells exert a potent inhibitory effect on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-gamma. In marked contrast, our studies have revealed that IL-4 produced by Valpha14 NKT cells has only a minor effect on Th2 cell differentiation.

Incidence of and risk factors for incisional hernia after closure of temporary ileostomy for colorectal malignancy.

PURPOSE: Incisional hernia is a major complication after stoma closure and can cause uncomfortable symptoms. In this study, we evaluated the risk factors for hernia formation with the aim of reducing the incidence of incisional hernia. METHODS: A total of 134 oncology patients underwent closure of a temporary loop ileostomy between May 2004 and December 2013. The incidence of incisional hernia was determined by routine follow-up computed tomography scanning every 6 months. The relationships between patients' characteristics, including age, sex, obesity, diabetes mellitus, surgical site infection, chronic obstructive pulmonary disease, hypertension, hypoalbuminemia, smoking, and presence of a midline hernia and the occurrence of incisional hernia were retrospectively evaluated. RESULTS: The median follow-up time was 47 months (range 8-130). Hernias occurred in 23.9% of patients (32/134). The median time to detection of hernias was 8 months (range 2-39). The Chi-squared test revealed significant differences in obesity (P = 0.0003), hypertension (P = 0.0057), and incisional hernia history (P = 0.0000) between patients with and without incisional hernia. Multivariable analysis and univariate analysis revealed that hypertension and the presence of midline incisional hernia were risk factors for incisional hernia. CONCLUSIONS: Hypertension and the presence of a midline incisional hernia were the major risk factors for incisional hernia after loop ileostomy closure. These risk factors can be addressed before planning surgery.

Activated extracellular signal-regulated kinase correlates with cyst formation and transforming growth factor-beta expression in fetal obstructive uropathy.

Human renal dysplasia is frequently associated with urinary tract obstruction and the abnormal expression of mitogen-activated protein kinase (MAPK). Here, we determined the renal responses and MAPK expression in developing kidneys that were obstructed in fetal lambs. Kidneys were harvested at various times after obstruction (gestation day 60) through normal term (day 145). Dilation of Bowman's capsule and proximal tubules was seen 2 days after obstruction and involved the whole cortex 18 days later, with numerous cysts present throughout the kidney at term. The proliferation marker Ki-67 and transforming growth factor-beta (TGF-beta) were detected 2 days after obstruction and progressively increased in tubules, cysts, and the interstitium. In control kidneys, p38 was expressed in tubules only during the fetal stage, whereas phosphorylated extracellular signal-regulated kinase (P-ERK) was limited to ureteric buds and collecting ducts at all stages examined. However, Jun-N-terminal kinase (JNK) was absent in the fetal kidney but present in tubules at term. In obstructed kidneys, cyst epithelia were positive for p38 and P-ERK but negative for JNK throughout all stages. These studies show that P-ERK correlated spatially and temporally with Ki-67 and TGF-beta expression, which suggests that ERK may contribute to cyst formation and fibrosis in the obstructed fetal kidney.

Immunohistochemical localization of V2 vasopressin receptor along the nephron and functional role of luminal V2 receptor in terminal inner medullary collecting ducts.

We investigated immunohistochemical localization of V2 vasopressin receptor along the nephron using a specific polyclonal antibody. Staining was observed in some of thick ascending limbs and all of principal and inner medullary collecting duct (IMCD) cells. Not only basolateral but also luminal membrane was stained in collecting ducts, especially in terminal IMCD (tIMCD). To learn the functional role of luminal V2 receptor in tIMCD, we studied the luminal effects of arginine vasopressin (AVP) on osmotic water permeability (Pf), urea permeability (Pu), and cAMP accumulation using isolated perfused rat tIMCD. In the absence of bath AVP, luminal AVP caused a small increase in cAMP accumulation, Pf and Pu, confirming the presence of V2 receptor in the lumen of tIMCD. In contrast, luminal AVP inhibited Pf and Pu by 30-65% in the presence of bath AVP by decreasing cAMP accumulation via V1a or oxytocin receptors and by an unknown mechanism via V2 receptors in the luminal membrane of tIMCD. These data show that V2 receptors are localized not only in the basolateral membrane but also in the luminal membrane of the distal nephron. Luminal AVP acts as a negative feedback system upon the basolateral action of AVP in tIMCD.

Successful treatment of hepatitis B virus-associated membranous nephropathy with lamivudine.

We present a case of chronic hepatitis B with membranous nephropathy, that was improved by lamivudine treatment. A 37-year-old man was admitted to our hospital for the evaluation of proteinuria. He was diagnosed as having chronic glomerulonephritis associated with chronic hepatitis B. Histopathological findings of the renal biopsy specimen indicated membranous nephropathy. He suffered from nephrotic syndrome associated with leg edema, which was parallel to the exacerbation of hepatitis. Lamivudine was started for the treatment of hepatitis, which caused the disappearance of serum hepatitis B virus DNA and the normalization of ALT level in 4 weeks. Additionally, proteinuria disappeared 120 weeks after the treatment was started. Lamivudine treatment may remit HBV-associated nephropathy.

Induction of superoxide anion production from monocytes an neutrophils by activated platelets through the P-selectin-sialyl Lewis X interaction.

Activated platelets expressing P-selectin on their surface are known to adhere to monocytes and neutrophils. We examined the possibility that the leukocytes were activated by their adhesion to activated platelets and demonstrated that P-selectin-dependent platelet adhesion to neutrophils and monocytes induced production of extracellular superoxide anion (O2-) by these leukocytes. Leukocyte membrane glycoproteins containing Ser/Thr-linked carbohydrate chains were responsible for the signal reception leading to the leukocyte activation. Cytokines were shown to influence these processes. For example, treatments of neutrophils with interleukin-8 (IL-8) or granulocyte colony-stimulating factor (G-CSF) potentiated the P-selectin-induced O2- production. Furthermore, interleukin-1 (IL-1) and interferon-gamma (IFN-gamma) induced surface expression of P-selectin on platelets in the presence of a low concentration of thrombin and consequently enhanced their adhesion capacity to leukocytes. These results indicated that the adhesion of activated platelets to the leukocytes through the interaction between P-selectin and its carbohydrate ligand, sialyl Lewis X (LeX), was a crucial step for the activation of leukocyte function and supported the notion that activated platelets were actively involved in the inflammatory processes.

Various AGC repeat numbers in the coding region of the human transcription factor gene E2F-4.

The E2F family of transcription factors regulates the expression of genes required for DNA synthesis and cell cycle control. The AGC triplet repeat in the coding region of the E2F-4 gene, a member of the family, has been reported to be mutated in colorectal cancers with a microsatellite instability (MSI) phenotype. We found a wider range variation of the repeat number in DNAs from tumors, the corresponding normal mucosa, and healthy individuals. A total of 5 repeat variants, ranging from 8 to 17 AGC repeats, was detected in 6 (9.7%) of the 62 healthy individuals and 8 (8.9%) of the 90 normal DNAs of the patients. The wild-type 13 repeat was present in all of these individuals. The variation of the AGC repeat number may be a polymorphism. Further, loss of heterozygosity (LOH) at the E2F-4 locus in the tumor tissues of 2 (25%) of the 8 informative cases was detected. The variation may be a useful marker for detection of LOH in primary tumors.

Density-dependent induction of TNF-alpha release from human monocytes by immobilized P-selectin.

P-selectin purified from human platelets, when immobilized on a solid surface, induced monocytes to release tumor necrosis factor-alpha (TNF-alpha). The induction of TNF-alpha release was dependent on the concentration of P-selectin used for the immobilization, and the maximal stimulation was observed when the plate was coated with 0.3 microgram/ml of P-selectin. Use of either a higher or a lower concentration of P-selectin for the plate-coating was found to elicit less TNF-alpha release, although the higher concentration of P-selectin caused a stronger adhesion of HL-60 leukemic cells. The expression of mRNA for TNF-alpha roughly paralleled the TNF-alpha secretion, as assessed by RT-PCR. These results indicate that monocytes are activated by immobilized P-selectin in a density-dependent manner.

The effect of Helicobacter pylori on cell proliferation and apoptosis in gastric epithelial cell lines.

BACKGROUND: Helicobacter pylori has been implicated in the pathogenesis of gastric cancer and malignant lymphoma. It is not known whether the bacterium stimulates cell proliferation directly or if apoptosis induced by H. pylori leads to a hyperproliferative response. AIM: To clarify the precise mechanism of H. pylori action on gastric epithelial cell growth, we compared the response of two cell lines, Kato III (p53 deletion) and MKN 45 (p53 wild type), to the organism. To determine the role of Helicobacter vacuolating cytotoxin in gastric mucosal injury, we examined the relation between vacuolating activity and apoptosis under several conditions. METHODS: Five cytotoxic and four noncytotoxic strains of H. pylori were used, each with an inoculum of 10(7) cfu/mL. The effect on the growth in MKN 45 and Kato III cells was studied by MTT assay. Vacuolating cytotoxin activity was determined using RK-13 cells. RESULTS: Neither cytotoxic nor noncytotoxic strains induced apoptosis, but death of MKN 45 cells was induced by pre-treatment with interferon-gamma and culture with TNF-alpha. In contrast, some strains of H. pylori increased proliferation of Kato III cells. Furthermore, cell death induced by cytotoxic strains, but not noncytotoxic strains, was significantly augmented by amoxycillin 5-50 g/mL (P=0.0016). On the other hand, acid-treated supernatant fluids from cultures of H. pylori showed enhanced vacuolating activity but did not induce cell death, suggesting that death is attributable to some factor other than the cytotoxin. CONCLUSION: These findings suggest that H. pylori induces apoptosis by a means independent of vacuolating cytotoxin.

Effects of oral adsorbent AST-120 on the progression of chronic renal failure: a randomized controlled study.

This prospective, randomized controlled study was designed to examine the effects of oral adsorbent AST-120 on the progression of chronic renal failure (CRF) in patients on a strict low protein diet (LPD). Twenty-six patients with CRF (serum creatinine 3.0 to 8.6 mg/dl) on a LPD were randomly assigned to a control group (N = 13) or an AST-120 group (N = 13). The 1/Cr slope and creatinine clearance (CCr) slope were used to estimate the progression rate of CRF; uremic toxins, serum and urinary indoxyl sulfate (IS), peak 2a and guanidino substrates (GS) measured by HPLC. Comparisons were made between the baseline observation period for 6 to 12 months and the treatment period (0.6 g/kg/day of LPD alone or concurrent with 6 g/day of AST-120, for the control and the AST-120 groups, respectively) for 12 to 24 months in both groups. Both the 1/Cr slope and CCr slope were significantly lessened in the treatment period only in the AST-120 group. Serum and urinary IS, but neither peak 2a nor GS were significantly decreased in the treatment period only in the AST-120 group. We conclude that AST-120 administration concurrent with LPD may be superior to LPD alone in retarding the progression of CRF by inhibiting accumulation of indoxyl sulfate.

[Dietary fiber inhibits the incidence of hepatic metastasis with the anti-oxidant activity and portal scavenging functions].

Dietary fiber is described as the proportion of plant foods not digested in the human small intestine. Among the various kinds of pectin, apple pectin exerts a bacteriostatic action and therefore may change the composition of the intestinal flora. The diet supplemented with 20% apple pectin significantly decreased the number and the incidence of AOM-induced colon tumors in rats. The prostaglandin E2 (PGE2) level in the distal colonic mucosa and blood of portal vein was lower in rats fed 20% pectin than those fed the basal diet. The ability of apple pectin to decrease PGE2 was dose-dependent and those results suggest an anti-inflammatory effect in the bowel. Rats fed apple pectin showed a significantly lower incidence of hepatic metastasis than those fed the basal diet. To determine whether the anti-inflammatory effect of Lactobacillus on hepatic metastasis model same as apple pectin, Lactobacillus casei was selected. Metastatic nodules were significantly reduced, especially in the group receiving pretreatment. Apple pectic oligosaccharides with small molecular weights showed highly inhibitory effects on hypoxanthin-xanthin oxidase and ferrous sulfate-hydrogen peroxide. The scavenging activity of apple pectic oligosaccharides was suitable and accelerated at high temperatures (120 degrees C, 30 min.). Apple pectin and Lactobacillus have a scavenger effect in the intestinal digestion and portal circulation system as an anti-inflammatory food and have very important function for the prevention of hepatic metastasis.

Role of urinary arginine vasopressin in the sodium excretion in patients with chronic renal failure.

Patients with chronic renal failure show almost equal levels of sodium excreted in the urine as healthy subjects through an increase of the fractional excretion sodium (FE(Na)). The mechanisms of this adaptation, however, are unknown. Recently, urinary arginine vasopressin (AVP) has been shown to inhibit the antidiuretic action of plasma AVP in the collecting ducts of rabbits and rats. In this article, the roles of plasma and urinary AVP are examined with other hormones in the sodium excretion of 57 patients with chronic renal disease. The fractional excretion of AVP, plasma atrial natriuretic peptide (ANP) and endothelin-1 (ET-1), urinary ET-1, and FE(ET-1) correlated with the decrease of creatinine clearance (Ccr). Multiple and stepwise regression analyses showed that FE(AVP) is the major dependent determinant for FE(Na) (adjusted r2 = 0.78). These results suggest that the increase of AVP excretion per remaining nephron could be a cause of the increase of FE(Na) in patients with renal failure. Although plasma AVP works as an antidiuretic hormone, urinary AVP serves as an intrinsic diuretic, especially in patients with chronic renal failure.

Cardiac malignant fibrous histiocytoma metastasizing to the brain: development of multiple neoplastic cerebral aneurysms.

We report a case in which bilateral occipital brain metastases and neoplastic cerebral aneurysms developed from primary cardiac malignant fibrous histiocytoma. The origin of metastases was confirmed at autopsy. The clinical presentation, radiographic features, and autopsy findings are presented along with a histopathologic analysis of the tumor.

Early fetal obstructive uropathy produces Potter's syndrome in the lamb.

BACKGROUND: If creating an obstructive uropathy early in glomerulogenesis produces MCDK (Multicystic Dysplastic Kidney), then a very early obstruction may produce Potter's Syndrome (PS) with oligohydramnios. METHODS: Fetal lambs at 50 days' gestation underwent urethral and urachal ligation using fine SILASTIC (Dow Corning, Midland, MI) tubing and were delivered by cesarean section at 145 days' gestation. At the time of death, kidney weight, length, and lung volumes were measured. These samples were examined histologically. Urinary sodium, chloride, potassium, and osmolarity also were measured. These were compared with normal-term fetuses. RESULTS: One ewe miscarried. Two of 3 of 50-day obstructive uropathy lambs survived. The 2 survivors had dysplastic kidneys. One with large gastroschisis did not have PS but the other had renal, pulmonary, and chest wall hypoplasia. Both male lambs had undescended testes with a large bladder. Kidney weights were 2 g in the PS lamb and 16 g in controls. Lung volume was 84 mL in the PS lamb and 340 mL in controls. The lamb's face was compressed and the fetus was hydropic. Urine sodium, potassium, and osmolarity levels were higher than that of controls. CONCLUSIONS: This is the first successful model ligating the penile urethra and urachus in a 50-day lamb. The authors' previous 60-day model did not have PS, but an earlier obstructive uropathy caused MCDK with PS.

Glomerular size in renal dysplasia secondary to obstructive uropathy: a further exploration of the fetal lamb model.

BACKGROUND/PURPOSE: Creating an obstructive uropathy early in glomerulogenesis would produce multicystic dysplastic kidneys (MCDK). Measuring the mean planar area of the glomeruli (GMPA) may clarify the pathogenesis of MCDK. METHODS: Fetal lambs at 60 days' gestation had their left ureter ligated and were delivered by cesarian section at 145 days' gestation. Kidney weight and length were recorded. GMPA in 3 zones (outer, middle, inner) of the sectioned kidney was measured using a computerized planimeter. The obstructed kidneys were compared with contralateral unobstructed kidneys. The unpaired Student's t test was used to determine significance. RESULTS: One ewe miscarried. Four of 5 (80%) 60-day lambs survived. All had dysplastic kidneys. Mean kidney weights were 4.3 +/- 0.84 g in MCDK and 16.8 +/- 3.6 g in controls (P< .05). The GMPA of the outer, middle, and inner zones of the MCDK were 2.7 x 10(-3) mm2, 3.2 x 10(-3) mm2, and 4.0 x 10(-3) mm2, respectively. Controls were 2.8 x 10(-3) mm2, 4.4 x 10(-3) mm2, and 6.0 x 10(-3) mm2. The glomeruli of 60-day fetal kidneys were 3.0 x 10(-3) mm2, 6.1 x 10(-3) mm2, and 11.0 x 10(-3) mm2. MCDK had smaller glomeruli in the inner and middle zones than controls. CONCLUSION: Fetal glomeruli appear to grow from the inner zone of the kidney. Early urinary tract obstruction stops this growth.

The pathogenesis of dysplastic kidney in a urinary tract obstruction in the female fetal lamb.

BACKGROUND/PURPOSE: The type of renal dysplasia resulting from obstructive uropathy depends on the completeness of the obstruction and its timing with respect to the stage of glomerulogenesis at the time of the obstruction. The authors created a successful obstructive uropathy model in the female fetal lamb to demonstrate the differing pathogenesis of renal dysplasia. METHODS: Female fetal lambs at 60 and 90 days' gestation had their urethra and urachus ligated transabdominally and were delivered by cesarean section at 145 days (full term). Kidney length and cortical thickness were measured, and samples were examined histologically. In the lambs operated on at 90 days, the urine was collected at delivery and Na and CI were measured and compared with the results obtained from normal full-term lambs. RESULTS: Seven of 10 female lambs had hydronephrosis or dysplastic kidneys. The cortext to kidney length ratio was 10+/-3% in the 90-days hydronephrotic group versus 29+/-6% in the controls (P<.001). Morphologically, the 90-day model had dilatation of the collecting tubules with normal glomerular numbers. The 60-day model had tubular cysts with fibromuscular cuffing and reduced glomerular numbers. The fetal urine Na was 47+/-3.3 mmol/L in controls versus 78+/-24 mmol/L in the hydropnephrotic lambs (P<.05). The urine CI in these lambs was 38+/-8.6 mmol/L in controls versus 55+/-14.5 mmol/L in the hydronephrotic lambs (P<.05). CONCLUSIONS: An obstructive uropathy model was created in female fetal lambs. There were no dysplastic changes in the kidneys in lambs operated on at 90 days' gestation, but there were definite dysplastic changes in those operated on at 60 days. Concentrations of Na and CI in the fetal urine are higher than normal in the 90-day model.

Colliding malignant lymphoma and adenocarcinoma of the stomach: case report.

We report a case of malignant lymphoma presenting as the superior vena cava syndrome. This case is very interesting since both adenocarcinoma mucocellulare scirrhosum, Borrman type IV, and lymphoma were present in the stomach, forming colliding neoplasms. Rather than systemically disseminated, the lymphoma cells were localized in the stomach, the intestine, a few perigastric lymph nodes and in a mediastinal mass, which may have constituted a neoplastic thymus invaded by lymphoma cells from the stomach. The unique occurrence of the histological combination as gastric colliding neoplasms is discussed.

Studies in the search for life on Mars.

The ability of living organisms to survive extraterrestrial conditions has implications for the origins of life in the solar system. We have therefore studied the survival of viruses, bacteria, yeast, and fungi under simulated Martian conditions. The environment on Mars was simulated by low temperature, proton irradiation, ultraviolet irradiation, and simulated Martian atmosphere (CO2 95.46%, N2 2.7%, water vapor 0.03%) in a special cryostat. After exposure to these conditions, tobacco mosaic virus and spores of Bacillus, Aspergillus, Clostridium, and some species of coccus showed significant survival.