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F A Mitros

Publications and source records attributed to F A Mitros.

At least 19 recordsLinked to original sources
PubMed2001

Germline mutations of the gene encoding bone morphogenetic protein receptor 1A in juvenile polyposis.

Juvenile polyposis (JP; OMIM 174900) is an autosomal dominant gastrointestinal hamartomatous polyposis syndrome in which patients are at risk for developing gastrointestinal cancers. Previous studies have demonstrated a locus for JP mapping to 18q21.1 (ref. 3) and germline mutations in the homolog of the gene for mothers against decapentaplegic, Drosophila, (MADH4, also known as SMAD4) in several JP families. However, mutations in MADH4 are only present in a subset of JP cases, and although mutations in the gene for phosphatase and tensin homolog (PTEN) have been described in a few families, undefined genetic heterogeneity remains. Using a genome-wide screen in four JP kindreds without germline mutations in MADH4 or PTEN, we identified linkage with markers from chromosome 10q22-23 (maximum lod score of 4.74, straight theta=0.00). We found no recombinants using markers developed from the vicinity of the gene for bone morphogenetic protein receptor 1A (BMPR1A), a serine-threonine kinase type I receptor involved in bone morphogenetic protein (BMP) signaling. Genomic sequencing of BMPR1A in each of these JP kindreds disclosed germline nonsense mutations in all affected kindred members but not in normal control individuals. These findings indicate involvement of an additional gene in the transforming growth factor-beta (TGF-beta) superfamily in the genesis of JP, and document an unanticipated function for BMP in colonic epithelial growth control.

Adenomatous Polyposis Coli↗
PubMed2000

Hepatitis C virus (HCV) infection and cryoglobulinemia: analysis of whole blood and plasma HCV-RNA concentrations and correlation with liver histology.

The influence of cryoprecipitate (CP) on liver histology and peripheral titers of hepatitis C virus (HCV) RNA was evaluated for 115 patients with chronic hepatitis. Fifty-four patients had measurable CP levels whereas 61 did not. Assessment of liver biopsies for grade of fibrosis revealed that patients with CP had increased fibrosis (P <.001) and incidence of cirrhosis (P =.001) compared with those without CP. In contrast, there was not a significant difference in the inflammatory activity score between the 2 groups. HCV RNA in whole blood (WB) and plasma (Pl) was evaluated in patients with or without CP by end-point-limiting dilution titer. Among patients with CP, WB titers were significantly higher than Pl titers (P <.001); however, there was no difference in WB or Pl titers in patients without CP (P =.068). Histological activity and fibrosis scores of patients from either group were compared with peripheral viral titers of WB and Pl, percentage of CP, rheumatoid factor (RF) titer, and serum alanine transaminase (ALT). There were significant correlations between the amount of fibrosis and the percentage of CP and rheumatoid factor titer, yet neither of the latter parameters was correlated with inflammatory activity. These data suggest that patients with CP and chronic hepatitis owing to HCV are more likely to have progressive disease than patients without CP. Furthermore, the presence of CP in patients infected with HCV appears to influence the amount of virus detected in patient Pl, suggesting that WB assays may be more reliable for HCV-RNA quantitation in patients with CP.

Adult↗
PubMed2000

Effect of endotoxin on opossum gallbladder motility: a model of acalculous cholecystitis.

OBJECTIVE: To determine whether endotoxin causes histologic changes in the gallbladder consistent with acalculous cholecystitis, and to determine the effects of endotoxin on gallbladder motility. SUMMARY BACKGROUND DATA: Acute acalculous cholecystitis is frequently seen in critically ill, septic patients, after prolonged fasting and gallbladder stasis. The pathogenesis of acalculous cholecystitis is unknown; however, previous studies have suggested that ischemia may play a role. METHODS: Adult opossums received Escherichia coli lipopolysaccharide. The gallbladder was removed for histologic examination or for physiologic studies 4 hours to 2 weeks later. For histologic examination, gallbladder strips underwent standard hematoxylin-and-eosin processing. For physiologic studies, they were mounted in a tissue bath to determine responses to cholecystokinin octapeptide or electrical field stimulation. RESULTS: Intravenous endotoxin at a dose of 0.005 mg/kg resulted in disrupted mucosal surfaces and areas of hemorrhage; higher doses of endotoxin resulted in coagulation necrosis, hemorrhage, areas of fibrin deposition, and extensive mucosal loss, consistent with an acute ischemic insult. Endotoxin abolished the contractile response to cholecystokinin octapeptide in gallbladder strips 4 hours after endotoxin administration. The 0.005-mg/kg dose of endotoxin decreased the contractile response to cholecystokinin octapeptide for up to 96 hours after endotoxin administration and decreased the contractile response to electrical field stimulation for 48 hours after administration. Inhibition of nitric oxide synthase reversed the decreased contractile response to cholecystokinin octapeptide. CONCLUSIONS: Endotoxin causes an ischemic insult to the gallbladder similar to that seen in acalculous cholecystitis. Also, endotoxin may lead to gallbladder stasis by decreasing gallbladder contractile responses to hormonal and neural stimuli.

Animals↗
PubMed1998

Mutations in the SMAD4/DPC4 gene in juvenile polyposis.

Familial juvenile polyposis is an autosomal dominant disease characterized by a predisposition to hamartomatous polyps and gastrointestinal cancer. Here it is shown that a subset of juvenile polyposis families carry germ line mutations in the gene SMAD4 (also known as DPC4), located on chromosome 18q21.1, that encodes a critical cytoplasmic mediator in the transforming growth factor-beta signaling pathway. The mutant SMAD4 proteins are predicted to be truncated at the carboxyl-terminus and lack sequences required for normal function. These results confirm an important role for SMAD4 in the development of gastrointestinal tumors.

Cell Membrane↗
PubMed1998

The risk of gastrointestinal carcinoma in familial juvenile polyposis.

BACKGROUND: Familial juvenile polyposis (JP) is an autosomal dominant condition in which affected individuals develop upper or lower gastrointestinal (GI) juvenile polyps, or both, and have a predisposition to cancer of the gastrointestinal tract. The risk of GI cancer has not been well defined because of the small number of these families and the lack of follow-up. The objective of this study was to determine the prevalence and age at diagnosis of GI polyposis and cancer in a large JP kindred. METHODS: Medical records were reviewed, patients were interviewed, and histories were taken. Pathology reports and slides were reviewed by our pathologists. A database was created for analysis of clinical and pathologic factors. RESULTS: This kindred contains 117 members, 29 of whom have had upper or lower GI polyps or cancer, or both. All those affected have had colonic juvenile polyps or cancer, except for two who died of advanced gastric cancer and never had colonic evaluation. Nine individuals have had both upper and lower GI polyps or cancer. Sixteen of 29 (55%) affected patients have developed gastrointestinal cancer. Eleven (38%) have had colon cancer, and six (21%) have had upper GI cancers. CONCLUSIONS: The risk of gastrointestinal malignancy in affected members of this JP kindred exceeds 50%. The high risk of GI cancer warrants frequent endoscopic screening of both affected and at-risk family members. Screening will soon be facilitated by presymptomatic genetic testing for the identification of gene carriers.

Adenomatous Polyposis Coli↗
PubMed1998

A gene for familial juvenile polyposis maps to chromosome 18q21.1.

Familial juvenile polyposis (FJP) is a hamartomatouspolyposis syndrome in which affected family members develop upper and lower gastrointestinal juvenile polyps and are at increased risk for gastrointestinal cancer. A genetic locus for FJP has not yet been identified by linkage; therefore, the objective of this study was to perform a focused genome screen in a large family segregating FJP. No evidence for linkage was found with markers near MSH2, MLH1, MCC, APC, HMPS, CDKN2A, JP1, PTEN, KRAS2, TP53, or LKB1. Linkage to FJP was established with several markers from chromosome 18q21.1. The maximum LOD score was 5.00, with marker D18S1099 (recombination fraction of .001). Analysis of critical recombinants places the FJP gene in an 11.9-cM interval bounded by D18S1118 and D18S487, a region that also contains the tumor-suppressor genes DCC and DPC4. These data demonstrate localization of a gene for FJP to chromosome 18q21.1 by linkage, and they raise the possibility that either DCC or DPC4 could be responsible for FJP.

Adolescent↗
PubMed1997

Surreptitious hepatitis C virus (HCV) infection detected in the majority of patients with cryptogenic chronic hepatitis and negative HCV antibody tests.

Reverse transcription-polymerase chain reaction was used to identify hepatitis C virus (HCV) RNA in peripheral whole blood (WB) and plasma samples from 15 patients with chronic, unexplained hepatitis. These patients were serologically negative for hepatitis A, B, and C and were classified as having chronic non-A, non-B, non-C hepatitis (NANBNC). HCV RNA was repeatedly detected in WB samples from 10 (67%). In contrast, plasma samples from only 5 were intermittently positive. Statistically, HCV RNA detection in WB was significantly more sensitive than in plasma. Nucleic acid hybridization and HCV genotypic analysis confirmed the specificity of the HCV RNA assay. Liver biopsies from these patients suggested histopathologic differences between HCV RNA-positive and -negative groups. These data demonstrate that HCV infection is present in patients with unexplained chronic hepatitis more frequently than previously believed. Additionally, WB HCV RNA detection is more sensitive than plasma assays in identifying antibody-negative HCV infection.

Adult↗
PubMed1996

Practice guideline development task force of the College of American Pathologists. Hereditary hemochromatosis.

Hereditary hemochromatosis is an autosomal recessive disorder, the gene for which occurs in approximately 10% of Americans, most of whom are unaffected heterozygotes. Approximately 5/1000 white Americans are homozygous and at risk of developing severe and potentially lethal hemochromatosis. The disorder affects numerous organ systems, but the most common symptoms are fatigue, palpitations, joint pains, and impotence; the most common signs are those that relate to hypothalamic, cardiac, hepatic or pancreatic dysfunction, including poor cold tolerance, impotence in males, amenorrhea in females, cardiac arrhythmias, dyspnea, edema, hepatosplenomegaly, spider telangiectases, ascites, deformity, swelling or limitation of motion of joints, weight loss, hyperpigmentation. Characteristic abnormalities of laboratory tests include elevated serum iron concentration, high transferrin saturation, elevated serum ferritin concentration, elevated serum transaminases, hyperglycemia and low values for thyroid-stimulating hormone (TSH) and gonadotropins. Death may be the result of cardiac arrhythmia, congestive heart failure, liver failure or liver cancer. Since many of these complications cannot be reversed once they have developed, early diagnosis and treatment are essential. In view of the high prevalence in the American population (prevalence varies with ethnic background), the low cost of diagnosis and treatment, the efficacy of treatment if begun early, and, on the other hand, high costs and low success rate of late diagnosis and treatment, systematic screening for hemochromatosis is warranted for all persons over the age of 20 years. The initial screening should be by measurement of serum iron concentration and transferrin saturation. The practice guideline provides a diagnostic algorithm for cases in which the serum transferrin saturation is 60% or greater. It also provides guidelines for clinical management.

Female↗
PubMed1994

Acute gastritis associated with spiral organisms from cats.

Numerous studies implicated Helicobacter pylori as one causative agent producing gastritis and dyspepsia. Recent reports focus on another bacterium, Gastrospirillum hominis, as a possible pathogen producing gastritis. We report a 30-year-old researcher who became acutely ill with epigastric pain indicative of esophagitis or peptic ulcer disease. Gastritis and a gastric ulcer were observed endoscopically. Histological examination of the gastric mucosa revealed an acute gastritis and large spiral-shaped organisms. The spiral forms were present in large quantities in the gastric mucosa of experimental animals (cats) handled by the patient in his research. Electron microscopy confirmed that the organisms from the cat and patient were morphologically identical. The patient was successfully treated with bismuth subsalicylate. His symptoms resolved and the organisms were cleared from his stomach. This study provides evidence that another bacterium, a Gastrospirillum, may cause gastritis in man and may be transmitted from animal to man.

Adult↗
PubMed1994

Eosinophilic cholecystitis, appendiceal inflammation, pericarditis, and cephalosporin-associated eosinophilia.

A patient with eosinophilic cholecystitis and accompanying eosinophilic appendiceal inflammation, eosinophilic pericarditis, and peripheral eosinophilia is described. Review of the nine previously reported cases of eosinophilic cholecystitis suggests that this is the first case with closely associated eosinophilic appendiceal inflammation and pericarditis as manifestations of a systemic hypereosinophilic syndrome. The possible etiologic role of cephalosporin hypersensitivity is discussed.

Adult↗
PubMed1994

Heat stress does not sensitize rats to the toxic effects of bacterial lipopolysaccharide.

To determine whether heat stress sensitizes rats to lipopolysaccharide (LPS), four groups were examined: saline, LPS, heat stressed+saline, and heat stressed+LPS treated rats. Saline or LPS (Escherichia coli, 5 mg.kg-1 body weight, i.v.) was given after exposure to heat and at the same time of day for nonheated rats. Survival was monitored for 24 or 48 h; samples of liver and small intestine were obtained at 24 h for histological analysis. Thermal responses were similar (P > 0.05) for the heat stressed saline and LPS treated rats: mean values for maximum colon temperature were 43.0 +/- 0.1 and 42.9 +/- 0.1 degrees C, respectively. Mortality was similar for rats exposed to heat stress+saline (11%, 2/19) and heat stress+LPS (32%, 6/19). No lethality was observed in nonheated rats given saline or LPS. Tissue damage was similar in heat stress+saline and heat stress+LPS treated rats. Liver showed mild to severe degrees of coagulative necrosis while duodenum exhibited damage to the villous tips. These findings show that severe heat stress does not markedly sensitize the rat to the lethal activity of LPS.

Analysis of Variance↗
PubMed1993

A staged surgical approach to save ischemic bowel.

A 15-year-old girl developed bowel strangulation of 80% of her small intestine by an omental sling. At exploration, only 100 cm of proximal jejunum remained clearly viable and the remaining small bowel looked necrotic. The transitional bowel between normal and ischemic segments was exteriorized to form a double-barreled jejunostomy. Twelve hours later a "second look" operation was performed. The bowel distal to the exteriorization appeared still seminecrotic but blood flow recovery was demonstrated along the mesenteric border by Doppler oxymeter. No bowel resection was performed. Two months later the jejunostomy was converted to a Bishop-Koop type side-to-end jejunostomy. In the ensuing 2 months, the patient passed both gas and stool per rectum, and oral feedings were gradually increased, retaining the jejunal stoma as a "safety valve." Later, the stoma was taken down, stenotic bowel segments were resected, and the bowel was finally reconstructed by an end-to-end anastomosis, preserving approximately 80% of the small intestine. This management strategy provides an alternative approach to the conventional practice of simple resection of severely ischemic bowel, allowing maximal salvage of bowel with reversible high-grade ischemic change in selected patients.

Adolescent↗
PubMed1993

Antineutrophil cytoplasmic antibody in inflammatory bowel and hepatobiliary diseases. High prevalence in ulcerative colitis, primary sclerosing cholangitis, and autoimmune hepatitis.

The prevalence of antineutrophil cytoplasmic antibodies was evaluated in patients with ulcerative colitis, primary sclerosing cholangitis, and various other gastrointestinal and hepatobiliary diseases to define the sensitivity and specificity of the test. The presence of antineutrophil cytoplasmic antibodies was detected in alcohol-fixed cytospin preparations of peripheral blood neutrophils with an indirect immunofluorescence technique. A perinuclear staining pattern was considered positive. Thirty-six of 50 patients (72%) with ulcerative colitis and/or primary sclerosing cholangitis had positive results. Twenty-two of 210 patients (10%) in the control group had positive findings, including a significant proportion of patients with autoimmune hepatitis (50%) and non-A, non-B and non-C hepatitis (27%). This test for antineutrophil cytoplasmic antibodies has a sensitivity of 72% and specificity of 90% for either ulcerative colitis or primary sclerosing cholangitis. It may be useful in the differential diagnosis of Crohn's disease and ulcerative colitis and in the early diagnosis of ulcerative colitis. It also may be employed to distinguish primary biliary cirrhosis from primary sclerosing cholangitis.

Adolescent↗
PubMed1993

Collagenous colitis associated with chronic constipation.

We present a case in which the classical histopathologic features associated with collagenous colitis were present throughout the colectomy specimen of a 69-year-old woman operated on for life-long intractable idiopathic constipation. This patient had never suffered from episodes of watery diarrhea. The reasons for this paradox are unclear, but suggest that a thickened collagen table and damaged surface epithelium may not be entirely specific pathologic findings marking the clinicopathological syndrome of collagenous colitis.

Aged↗
PubMed1993

Atheroemboli-associated polyps of the sigmoid colon.

Atheroemboli-associated inflammatory type polyps localized to a portion of the sigmoid colon occurred in a 68-year-old diabetic man presenting with a 2-year history of bloody diarrhea and abdominal pain. The patient underwent segmental resection of the sigmoid colon. The specimen contained 15 polyps ranging from 0.3 to 1.9 cm in greatest dimension, localized to an 8-cm length of sigmoid colon. The polyps had an edematous submucosa with a superficially ulcerated mucosa. Microscopically, arterioles within the submucosa of the polyps contained organized atheroemboli. The overlying mucosa was largely replaced by granulation tissue, with foci of coagulation necrosis present in residual mucosa. The remainder of the bowel was unremarkable. The histologic diagnosis of atheroembolization to the gastrointestinal tract is difficult, requiring the inclusion of submucosa with atheroemboli in the biopsy tissue. Ischemic ulcers and erosions as well as inflammatory polyps related to atheroemboli may require deeper biopsy for etiologic diagnosis.

Aged↗
PubMed1992

Fine-needle aspiration findings of the liver in a case of Q fever.

This report describes the cytologic findings in Q fever involving the liver in a 59-yr-old man. The fine-needle aspiration findings are correlated with a surgical needle biopsy performed concurrently. Cytopathologists should include Q fever in their differential diagnosis of granulomatous inflammation. Ring granulomas, which can be seen in an aspiration biopsy, should suggest the diagnosis of Q fever.

Biopsy, Needle↗