Platinum-resistance in ovarian cancer cells is mediated by IL-6 secretion via the increased expression of its target cIAP-2.

Ovarian carcinoma patients are initially responsive to platinum-based therapy, but eventually become refractory to treatment due to the development of platinum chemoresistance. Elevated levels of interleukin-6 (IL-6) in the sera and ascites of these patients predict poor clinical outcome. Our goal was to analyze the interaction between cisplatin and cisplatin-resistant ovarian cancer cells, and to identify means of circumventing platinum resistance. We studied ovarian carcinoma cell lines and cells drawn from ovarian carcinoma patients. Gene array analyses were performed on ovarian carcinoma cells upon treatment with cisplatin, and the results were validated by ELISA and Western blotting (WB). Cytotoxicity assays were performed on anti-IL-6 Ab-, IL-6-, and cellular inhibitor of apoptosis 2 (cIAP-2) siRNA-treated cells, following cisplatin addition. Our results revealed a highly significant increase in IL-6 and cIAP-2 mRNA and protein levels upon treatment with cisplatin. WB analysis of cisplatin-treated cells exhibited decreased cIAP-2 expression level following anti-IL-6 Ab addition. Furthermore, IL-6 by itself, significantly increased cIAP-2 levels in ovarian carcinoma cells. Finally, cytotoxicity assays showed sensitization to cisplatin following the addition of IL-6 and cIAP-2 inhibitors. In conclusion, cisplatin treatment of ovarian carcinoma cells upregulates IL-6 and cIAP-2 levels while their inhibition significantly sensitizes them to cisplatin. Here, we present cIAP-2 as a novel inducer of platinum resistance in ovarian carcinoma cells, and suggest an axis beginning with an encounter between cisplatin and these cells, mediated sequentially by IL-6 and cIAP-2, resulting in cisplatin resistance. Consequently, we propose that combining IL-6/cIAP-2 inhibitors with cisplatin will provide new hope for ovarian carcinoma patients by improving the current treatment.

Prognostic significance of HER-2/neu expression in patients with ductal carcinoma in situ.

BACKGROUND: The prognostic significance of biologic markers in women with ductal carcinoma in situ is not fully understood. HER2/neu is a marker of prognostic significance that is routinely assessed in invasive cancer but its correlation with clinical outcome in DCIS is still obscure. OBJECTIVES: To evaluate the significance of HER-2/neu expression as a prognostic marker in DCIS. METHODS: Clinical and pathologic data from 84 patients treated for DCIS were analyzed. HER-2/neu expression was determined by immunohistochemical staining. Histopathologic parameters (nuclear grade, histologic subtype, necrosis, calcifications, margins) were reviewed by an experienced pathologist. Local recurrence and/or metastatic spread were used as endpoints to determine the prognostic significance of HER-2/neu expression. RESULTS: With a median follow-up of 94.8 months, nine recurrences were reported. Neither univariate nor multivariate analysis showed a significant correlation between HER-2/neu expression and disease recurrence or the time to disease recurrence. Although HER-2/neu expression demonstrated a significant association with high nuclear grade (P < 0.0001) and comedo subtype (P < 0.0001), there was no correlation between these histologic features and recurrence rate. The correlation between high nuclear grade and disease recurrence approached statistical significance (P = 0.07). CONCLUSIONS: No significant association was found between HER-2/neu expression in DCIS and disease recurrence. However, HER-2/neu correlated with negative markers such as nuclear grading and comedo necrosis, and its role should therefore be investigated in larger studies.

Morphology of the human tympanic membrane annulus.

OBJECTIVE: To study the full panoramic view with figuring of the morphology and topography of the human tympanic annulus. STUDY DESIGN: Postmortem material analysis. SETTING: University-affiliated hospital. SUBJECTS AND METHODS: Twenty-three single, normal human adult tympanic membranes were completely extracted from formalin-fixed temporal bones. They were faced medially and placed at the same level of a graph paper mounted on a board. High-quality images of the tissue preparations were taken, and computer-aided measurements of the annular caliber were calculated at nine reference points. The 6 o'clock direction served as a midpoint, and another four reference points were set anteriorly and posteriorly in clockwise and counterclockwise directions. RESULTS: The annulus has a horseshoe-like shape with a small part absent above the neck of the malleus. The maximal mean caliber at the manubrial axis (6 o'clock direction) was 748 +/- 201 mum. The annulus gradually thins out almost symmetrically anteriorly and posteriorly, until it reaches about 15 percent of the maximal caliber at its end points (152 +/- 87 and 113 +/- 42 mum, respectively). Significant differences were found between adjacent reference points on both anterior and posterior sides. CONCLUSIONS: The annulus has a horseshoe-like shape and gradually thins out almost symmetrically, reaching anteriorly and posteriorly about 15 percent of the maximal caliber at the manubrial axis. These new data may provide guidance in transcanal middle ear exploration and suggest the possibility of varied functions attributable to the annulus regarding middle ear sound transmission and TM vibratory properties. The data may contribute to understanding the development of marginal perforations and posterior superior retraction pockets.

An animal model for chemotherapy-associated steatohepatitis and its prevention by the oral administration of fatty acid bile acid conjugate.

BACKGROUND: Preoperative chemotherapy for hepatic resection of colorectal liver metastases is associated with the development of chemotherapy-associated steatohepatitis (CASH). This increases the risk of perioperative morbidity and mortality. To the authors' knowledge, an animal model for CASH has not been described previously. It has been established that fatty acid bile acid conjugates (FABACs) prevent the formation of diet-induced fatty liver. The current study was designed to establish an animal model of CASH and to use that model to study the effect of FABACs on its occurrence. METHODS: C57BL/6 mice were given different doses of oxaliplatin and irinotecan. Oxaliplatin administered once weekly at a dose of 6 mg/kg for a total dose of 24 mg/kg was tolerated best and was associated most consistently with CASH. Thus, that dose was chosen as the induction model for CASH. Subsequently, mice were divided into a control group (no treatment), an oxaliplatin group, and a CASH-prevention group, which received oxaliplatin and C20-FABAC at a dose of 150 mg/kg daily. The animals were killed after 28 days. RESULTS: Liver fat content was significantly lower (P < .0001) in the control group (51.63 mg/g) and the prevention group (62.13 mg/g) compared with the oxaliplatin group (95.35 mg/g). This difference was mainly because of the accumulation of liver triglycerides in the oxaliplatin group. CONCLUSIONS: The current results indicated that C57BL/6 mice receiving weekly oxaliplatin can be used as a model for CASH. Oral FABAC therapy reduced the development of CASH in animals that received oxaliplatin. To the authors' knowledge, this report is the first description of a model and a potential preventive treatment for CASH.

Treatment of preestablished diet-induced fatty liver by oral fatty acid-bile acid conjugates in rodents.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrialized countries. It has no accepted medical therapy. Fatty acid-bile acid conjugates (FABACs) were proven to prevent diet-induced NAFLD in rodents. AIM: This study was undertaken to test whether oral FABACs are also effective in reducing liver fat in preestablished diet-induced NAFLD. METHODS: NAFLD was induced in mice and rats by a high-fat diet and maintained by various proportions thereof. The FABACs used were conjugates of cholic acid with either arachidic or stearic acids. RESULTS: FABAC therapy reduced liver fat in all four series of experiments. The rapidity of the effect was inversely proportional to the concentration of fat in the maintenance diet. In mice on a 25% maintenance diet FABACs decreased total liver lipids by about 30% in 4 weeks (P<0.03). Diglycerides (P<0.003) and triglycerides (P<0.01) were the main neutral liver lipids that decreased during FABAC therapy. Both FABACs tested reduced liver fat in NAFLD at doses of 25 and 150 mg/kg/day. High-fat diet increased, whereas FABAC therapy decreased plasma 16 : 1/(16 : 0+16 : 1) fatty acid ratio - a marker of stearoyl CoA desaturase activity. In HepG2 cells FABACs decreased de-novo fatty acid synthesis dose dependently. CONCLUSION: Oral FABAC therapy decreased liver fat in preestablished NAFLD in mice and rats. Inhibition of stearoyl CoA desaturase activity and fatty acid synthesis are mechanisms that may contribute to this decrease. FABACs may be potential therapeutic agents for human NAFLD.

Pressure equilibration in the penguin middle ear.

CONCLUSIONS: King penguins have a venous structure in the form of a corpus cavernosum (CC) in their middle ear (ME) submucosa. The CC may be viewed as a special organelle that can change ME volume for pressure equilibration during deep-sea diving it is a pressure regulating organelle (PRO). A similar CC and muscles also surround the external ear (EE) and may constrict it, isolating the tympanic membrane from the outside. A CC was previously found also in the ME of marine diving mammals and can be expected to exist in other deep diving animals, such as marine turtles. OBJECTIVES: Marine animals require equalization of middle ear (ME) pressure when diving hundreds or thousands of meters to catch prey. We investigated what mechanism enables king penguins to protect their ME when they dive to great depths. MATERIALS AND METHODS: Biopsies and serial sections of the ME and the EE of the deep diving king penguin (Aptenodytes patagonicus) were examined microscopically. RESULTS: It was demonstrated that the penguin ME has an extensive network of small and large submucosal venous sinuses. This venous formation, a corpus cavernosum, can expand and potentially 'flood' the ME almost completely on diving, thus elevating ME pressure and reducing the ME space. The EE has a similar protective mechanism.

Specimen length as a perioperative surrogate marker for adequate lymphadenectomy in colon cancer: the surgeon's role.

The objective of this study was to determine whether there is a correlation between the length of the sigmoid colon removed and the number of harvested lymph nodes (LNs). Pathology charts of 137 sigmoid resections that were done over a 5-year period were reviewed. The length of removed sigmoid specimen reported in the pathology reports was correlated with the number of LNs retrieved from the specimen. The mean and median numbers of retrieved LNs were 9 and 10, respectively. There was an increase in the number of retrieved LNs with increasing length of resected sigmoid colon. For Dukes' B patients, the average length of the resected specimen was 15.1 cm for those with < 12 LNs and 20.3 cm for those with > 12 LNs (P = 0.01). Our data suggest that the surgeon may play an important role in determining the extent of LN harvesting during large bowel resection for cancer.

Diffuse disseminated candidiasis in a patient with Felty's syndrome: a case report.

Severe granulocytopenia predispose patients with Felty's syndrome to severe infectious diseases. The following report deals with an occurrence of chronic disseminated candidiasis in a patient with Felty's syndrome who presented with prolonged and severe granulocytopenia. To the best of our knowledge this coexistence has never been described before.

Additive renoprotective effect of candesartan and tetrahydrobiopterin in rats after 5/6 nephrectomy.

BACKGROUND: Chronic treatment with candesartan cilexetil (C) improves the outcome of rats after 5/6 nephrectomy (Nx). Tetrahydrobiopterin (BH4), an essential cofactor for appropriate endothelial nitric oxide synthase (eNOS) activity, prevents an increase in blood pressure (BP) in Nx rats when given immediately after surgery. In the present study, we evaluated the renoprotective effect of a combined treatment. METHODS: Five groups of rats were studied: SHAM (sham-operated rats, n=12); SNx (untreated 5/6 nephrectomized rats, n=15); C (SNx rats treated with candesartan cilexetil, 5 mg/kg/day per os, n=11); C+BH4 (SNx rats treated with candesartan cilexetil and BH4, 10 mg/kg/day intraperitoneally, n=11); and BH4 (SNx rats treated with BH4, 10 mg/kg/day intraperitoneally, n=11). Treatment began 30 days after surgery, when hypertension and renal insufficiency have developed. This day was considered as day 1 of treatment for statistical comparisons. The study was continued until 50% mortality was achieved in the SNx rats (4 months after surgery). RESULTS: The survival rates were 100% for SHAM, 47% for SNx, 50% for BH4, 64% for C and 80% for C+BH4 (P<0.05 vs all). Untreated Nx rats developed hypertension, proteinuria (UP) and severe renal insufficiency. Mortality was associated with a lower renal function and increased urine protein excretion. In C and C+BH4 rats, systolic blood pressure (SBP) decreased significantly. BH4 alone had a mild non-significant effect on SBP. C and C+BH4 treatments attenuated significantly the increase in proteinuria found in SNx animals. The weight of the remnant kidneys as well as the severity of glomerulosclerosis were significantly lower in the C+BH4 rats. CONCLUSION: This study shows that in subnephrectomized rats, addition of BH4 to a treatment with candesartan had an additive renoprotective effect. The mechanism of such action may include a better control of BP associated with a blockade of actions of angiotensin II (Ag II), an improvement in nitric oxide synthesis and a balanced redox.

Halofuginone reduces the occurrence of renal fibrosis in 5/6 nephrectomized rats.

BACKGROUND: Halofuginone is a novel antifibrotic agent that can reverse the fibrotic process by specific inhibition of collagen type I synthesis. OBJECTIVES: To evaluate the effect of Halo on the development of glomerulosclerosis and interstitial fibrosis in the 5/6 nephrectomy rat model METHODS: Male Wistar rats were assigned to undergo 5/6 NX or sham operation, and then divided into three groups: 5/6 NX rats (NX-Halo and NX-Control) and sham. Systolic blood pressure, proteinuria and body weight were determined every 2 weeks. At sacrifice (10 weeks) creatinine clearance was evaluated and remnant kidneys removed for histologic examination, sirius red staining and in situ hybridization RESULTS: Systolic blood pressure increased progressively in both 5/6 NX groups. Halo slowed the increase in proteinuria in 5/6 NX rats. As expected, creatinine clearance was lower in 5/6 NX groups when compared to sham rats. Creatinine clearance was significantly higher in the NX-Halo group at the end of the study period. Histologic examination by light microscopy showed significantly less severe interstitial fibrosis and glomerulosclerosis in Halo-treated rats. The increase in collagen alpha1 (I) gene expression and collagen staining after nephrectomy was almost completely abolished by Halo. CONCLUSIONS: Halofuginone reduced proteinuria as well as the severity of interstitial fibrosis and glomerulosclerosis in 5/6 NX rats. The renal beneficial effect of Halo was also demonstrated by the blunted decrease in creatinine clearance observed in the treated animals.

Epithelial shedding of the inferior turbinate in perennial allergic and nonallergic rhinitis: a riddle to solve.

OBJECTIVE: To examine the epithelial integrity of the inferior turbinate in patients with perennial allergic rhinitis (PAR) and perennial nonallergic (vasomotor) rhinitis (PNAR). DESIGN: Nonrandomized, controlled morphometric study. SETTING: University-affiliated hospital. PATIENTS: Fifty-eight inferior turbinate samples were processed for histological study. Nineteen were from patients with PAR, and 20 were from patients with PNAR. Samples from 19 healthy individuals who underwent rhinoplasty for cosmetic reasons served as control specimens. MAIN OUTCOME MEASURES: The length of the basement membrane (BM) covered with intact epithelium, covered with a single layer of basal cells, and devoid of epithelium was measured. RESULTS: Intact respiratory epithelium and areas of partial and complete epithelial denudation were encountered in control specimens and in samples from patients with PAR and PNAR. A significant difference was found between the 3 groups (P = .001). The proportion of the BM covered with undamaged epithelium was significantly greater in control specimens and in samples from patients with PNAR than in samples from patients with PAR; the difference between the former 2 groups was nonsignificant. Most of the epithelial damage in patients with PAR occurred between columnar and basal cells rather than between basal cells and the BM (P = .02). CONCLUSIONS: Epithelial shedding of the inferior turbinate is a genuine feature of PAR and is not an artifact of tissue sampling. The finding of greater epithelial exfoliation between basal cells and the more superficial columnar cells than between basal cells and the BM probably reflects different attachment qualities of these cells.

Predominance of younger age, advanced stage, poorly-differentiated and mucinous histology in Israeli Arab patients with colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) incidence in the Israeli population is higher in the Jewish population than among Arabs. MATERIALS AND METHODS: To determine the differences in demographic, clinical, histopathological and molecular characteristics of CRC between these two ethnic groups, 125 Arab patients treated at 3 community hospitals over a 20-year period were compared to a group of 208 consecutive Jewish patients. The mutator (replication error-positive [RER]) phenotype was detected by immunohistochemical evaluation of hMLH1 and hMSH2 protein expression in tumor tissue. RESULTS: The Arab patients were younger than the Jewish patients with a higher percentage of poorly-differentiated and mucinous cancers and a higher percentage of advanced stage cancers (Dukes' C+D) at presentation. The mutator phenotype was detected at similar rates in both ethnic groups. CONCLUSION: Our study demonstrated that CRC patients from two major ethnic populations in Israel, Arabs and Jews, differed in terms of the prevalence of the disease, pathological features and age at presentation, but not in frequency of mismatch-repair-positive cancers.

Microsatellite instability in multiple nonfamilial malignancies.

Development of multiple tumors of different histopathologic types may suggest a profound generalized genetic defect, such as malfunction of DNA mismatch repair (MMR) mechanism. Defects in this mechanism are best reflected in microsatellite instability (MSI). We aimed to determine the role of MSI in a group of patients with dual malignancies and compared the data with that of patients with a single malignancy. Fifty patients were enrolled in the study, of whom 16 patients developed both solid and hematologic nonfamilial malignancies, 18 patients developed a single matched hematologic malignancy, and 16 a single matched solid malignancy. Five microsatellite markers were replicated by polymerase chain reaction (PCR) after DNA extraction from paraffin-embedded tissue blocks and analyzed by the GeneScan Analysis Software. The MSI-high phenotype was defined as instability in at least 40% of the examined loci. A higher prevalence of MSI-high phenotype was found in patients with dual malignancies (31.3%) compared with patients with single hematologic (5.6%) or solid malignancy (6.3%) (P = 0.0498 and 0.07, respectively). In conclusion, defects in DNA MMR mechanism may have an important role in the development of multiple sporadic nonfamilial malignancies.

Expression of the intestinal marker Cdx2 in secondary adenocarcinomas of the colorectum.

CONTEXT: Secondary adenocarcinomas of the large bowel can closely mimic primary tumors. The differentiation of secondary from primary adenocarcinomas of the colorectum, however, is important because their clinical management and prognosis are different. Immunostaining with the nuclear transcription factor Cdx2, expressed in normal intestinal epithelia and colorectal adenocarcinomas, could be of potential diagnostic use. OBJECTIVE: To investigate the diagnostic value of Cdx2 immunoexpression in distinguishing primary from common forms of secondary colorectal adenocarcinomas. DESIGN: Cdx2 immunoexpression was analyzed in 20 primary colorectal adenocarcinomas and in 34 secondary colorectal adenocarcinomas and their corresponding primary tumors. All secondary tumors were diagnosed through endoscopic biopsies and included 8 cases of ovarian (4 serous, 2 mucinous, and 2 endometrioid), 6 of mammary (4 lobular and 2 ductal), 4 of gastric (2 intestinal and 2 diffuse), 4 of pulmonary, 4 of pancreatic (ductal), 3 of prostatic, 3 of colorectal, and 2 of endometrial origin. RESULTS: Cdx2 was expressed in normal colorectal epithelium, in primary colorectal adenocarcinomas (20/20 cases), in secondary adenocarcinomas of colorectal (3/3) and gastric (3/4) origin, and in metastatic ovarian mucinous adenocarcinomas (2/2). In contrast, no Cdx2 immunoreactivity was observed in secondary colorectal tumors of ovarian (serous and endometrioid), mammary, pancreatic, pulmonary, prostatic, and endometrial origin. CONCLUSION: Cdx2 immunostaining may be useful in discriminating primary colorectal carcinomas from frequent types of secondary colorectal adenocarcinomas of nongastrointestinal origin. We suggest including Cdx2 in any antibody panel put together to distinguish between primary and secondary epithelial colorectal malignancies.

Effect of chronic tetrahydrobiopterin supplementation on blood pressure and proteinuria in 5/6 nephrectomized rats.

BACKGROUND: Tetrahydrobiopterin (BH4) is a key cofactor of nitric oxide (NO) synthase. Reduced BH4 levels may mediate endothelial NO synthase uncoupling, resulting in reduced NO synthesis and enhanced oxidative stress. In rats after 5/6 nephrectomy (Nx), administration of BH4 prevents the onset of hypertension, typically observed 10 days after Nx. This effect is associated with an increased synthesis of NO. The aim of the present study was to evaluate the effect of chronic BH4 therapy on blood pressure and renal morphology. METHODS: During an 8 week period, five groups of rats were studied: untreated 5/6 Nx rats, BH4-treated Nx rats (BH4, 10 mg/kg body weight/day administered intraperitoneally), l-arginine treated Nx rats (LA, 130 mg/kg/day), diltiazem-treated Nx rats (DILT, 30 mg/kg/day) and sham-operated rats. Treatments were commenced 24 h after surgery. Systolic blood pressure values (SBP), 24 h proteinuria (UP) and creatinine clearance rate (CCR) were assessed before and at weeks 4 and 8 of the study period. Histological changes in the kidney were evaluated at the end of the study (week 8). RESULTS: Compared with baseline, in Nx rats both SBP and UP increased significantly (112+/-1 to 136+/- 1.4 mmHg, P<0.01 and 23+/-2 to 127 +/- 26 mg/day, P<0.01, respectively). Treatment with BH4 normalized SBP values as did treatment with LA and DILT (109+/-3, 115+/-2 and 114+/-2 mmHg, respectively). UP was markedly reduced by BH4, the reduction being similar to that obtained by LA and significantly more marked than that of DILT rats (20+/-2, 28+/-3 and 62+/- 14 mg/day, respectively). CCR was equally decreased in all Nx groups. Histological evaluation showed the development of mesangial expansion in Nx rats, an effect that was significantly blunted by all treatments. CONCLUSIONS: In rats after 5/6 nephrectomy, BH4 supplementation initiated 24 h after surgery and maintained for 8 weeks preserved SBP, reduced UP and prevented the development of glomerular mesangial expansion.

Microsatellite instability in gastric MALT lymphoma.

The role of microsatellite instability and defects in DNA mismatch repair mechanism in the pathogenesis of gastric lymphoma of mucosa-associated lymphoid tissue (MALT) type is still controversial, as both negative and positive findings have been reported. This may be explained mainly by arbitrary selection of the tested loci, the use of various techniques of microsatellite instability analysis and by different definitions of replication error positive phenotype. The aim of our study was to evaluate the instability at selected microsatellite markers using the GeneScan Analysis Software. DNA from paraffin-embedded tissue blocks of 13 previously untreated patients with localized gastric MALT lymphoma was extracted. Five microsatellite markers, which are located in hMSH2, hMLH1, P16, APC and MLL loci, were selected from the genetic database. We found genetic instability in tumors of 9/13 patients with gastric MALT lymphoma (69%). Seven of them had replication-error-positive phenotype (54%). Microsatellite instability was found in 39% of the samples in the MLL locus, 39% in the APC, 46% in the P16, 23% in the hMLH1 and none in the hMSH2. This study demonstrates that microsatellite instability has more prominent role in pathogenesis of gastric MALT lymphoma than reported to date. We suggest that microsatellite instability should be analyzed with markers adjacent to chromosomal loci that are involved in lymphomas. Our findings support the 'Real Common Target genes' theory of high rate of microsatellite instability in specific genes, which are associated with related tumors.

The rising incidence of adult acute epiglottitis and epiglottic abscess.

OBJECTIVE: To examine preliminary observations that the incidence of adult acute epiglottitis has risen between 1986 and 2000. MATERIALS AND METHODS: Demographics, annual and seasonal occurrences, clinical presentation, diagnostic procedures, treatment, airway management, and complications of 116 consecutive adult patients with laryngoscopically confirmed acute epiglottitis are presented. RESULTS: The mean annual incidence of acute epiglottitis per 100,000 adults significantly increased from 0.88 (from 1986-1990) to 2.1 (from 1991-1995) and to 3.1 (from 1996-2000) (P <.001). This rise seems to be unrelated to Haemophilus influenzae type b infection but related to miscellaneous pathogenic bacteria. During these periods, the number of epiglottic abscesses increased concomitantly with the rise in the incidence of acute epiglottitis (from 4/14 episodes [29%], to 8/38 [21%], and to 16/66 [24%], respectively), showing a relatively constant ratio between both phenomena (P =.843). Twenty-five patients (21%) underwent airway intervention, 16 because of objective respiratory distress and 9 because of imminent respiratory obstruction. Stepwise logistic regression showed that drooling, diabetes mellitus, rapid onset of symptoms, and abscess formation were associated with airway obstruction. Diverse origins for the epiglottic abscess, either from coalescent epiglottic infection or from mucopyocele of the tongue base, are suggested. CONCLUSIONS: A rise in the incidence of acute epiglottitis and a concomitant rise in the number of epiglottic abscesses were established. Although the course of acute epiglottitis is often benign and can be safely treated with a conservative management approach, delayed airway obstruction may develop from a few hours to days after admission.

Does vascular endothelial growth factor (VEGF) play a role in the pathogenesis of minimal change disease?

BACKGROUND: Minimal change disease (MCD) is one of the major causes of nephrotic syndrome both in children and adults. The pathogenesis of this condition is not clear and it has been suggested that a plasma permeability factor may play a role. Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, has been thought to be one the factors involved. The aim of this study was thus to investigate the role of VEGF in the pathogenesis of MCD. METHODS: The expression of the gene for VEGF and VEGF receptor-2 (VEGFR-2) was estimated using in situ hybridization in renal biopsy specimens taken from patients with nephrotic syndrome and diagnosed histologically as MCD. The results were compared with those obtained in normal renal tissue. Biopsy specimens from eight patients diagnosed as having MCD were randomly selected for the study. The patients were aged 4-60 years at the time of the biopsy. There were four females and four males. All patients had presented with a nephrotic syndrome, five with recent onset of the disease, two with repeated attacks of the syndrome and one had reduced renal function. RESULTS: The gene expression for VEGF, measured as the proportional glomerular area occupied by autoradiographic grains, was significantly less in the patients with MCD than in controls (1.9 +/- 0.4 vs 4.8 +/- 0.6%, P < 0.0025), whereas the gene expression for VEGFR-2 was no different to controls (1.9 +/- 0.4 vs 2.0 +/- 0.2%). CONCLUSIONS: MCD is associated with a reduction in the expression of the gene for VEGF. As VEGF may play an important role in renal repair and survival, it is postulated that the deficiency, which we have shown, may lead to the dysregulation of the repair process in MCD.

Angiogenic switch in earliest stages of human colonic tumorigenesis.

BACKGROUND: Angiogenesis is activated in numerous physiological and pathological conditions. We examined whether new vessel formation exists in the earliest stages of colonic tumorigenesis. MATERIALS AND METHODS: Microvascular density (MVD) was examined in 176 formalin-fixed and paraffin-embedded aberrant crypt foci (ACF) dissected from macroscopically-normal mucosa obtained from patients with colorectal cancer. ACF were classified as non-hyperplastic, non-dysplastic (NH-ACF, n = 80), hyperplastic (H-ACF, n = 72) and dysplastic (D-ACF, n = 24). Mucosal strips were stained with methylene blue solution and screened under x 40 magnification for ACF. The identified ACF were microdissected and stained with an anti-CD-34 monoclonal antibody. MVD in ACF were compared to that of normal corresponding mucosa. RESULTS: The mean MVD for normal mucosa and ACF were 13.7 +/- 7.7 and 23 +/- 13, respectively. Microvessel counts increased in NH-ACF versus normal mucosa (18.7 +/- 10 vs. 13.7 +/- 7.7, p = 0.05), in H-ACF versus NH-ACF (24.8 +/- 14 vs. 18.7 +/- 10, p = 0.002) and in D-ACF versus H-ACF (31.7 +/- 10 vs. 24.8 +/- 14, p = 0.014). We further evaluated the effect of low-dose aspirin on MVD in ACF. No effect of aspirin on microvessel counts could be detected. CONCLUSION: Our data suggest that angiogenesis occurs in ACF which are the earliest morphologically identifiable preneoplastic and early neoplastic lesions in colonic mucosa. With progression from NH-ACF to D-ACF there is a progressive, statistically significant increase in MVD, suggesting active angiogenesis during the earliest steps of colorectal tumorigenesis.