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J H Yardley

Publications and source records attributed to J H Yardley.

At least 19 recordsLinked to original sources
PubMed1997

Genetic alterations and epithelial dysplasia in juvenile polyposis syndrome and sporadic juvenile polyps.

Juvenile polyps are regarded as hamartomatous polyps and occur in sporadic and familial syndromic settings. There is increased risk of gastrointestinal neoplasia in patients with juvenile polyposis syndrome, but the molecular mechanisms are not known. We therefore studied 78 colorectal juvenile polyposis from 12 patients with juvenile polyps syndrome and 34 sporadic juvenile polyps for epithelial dysplasia and genetic changes associated with colorectal neoplasia. Dysplasia occurred in 31% of syndromic juvenile polyps but not in sporadic juvenile polyps (P < 0.0001). Topographic control of proliferation and expression of the cyclin-dependent kinase inhibitor p21(WAFI/CIP1) seen in native colorectal epithelium was lost in 79% of dysplastic juvenile polyps and in 8% of nondysplastic juvenile polyps (P < 0.000001). Somatic mutations in the adenomatous polyposis coli (APC) gene were demonstrated in 50% of dysplastic juvenile polyps (3 of 6) but not in any of 16 juvenile polyps without dysplasia (P = 0.01). Both sporadic and syndromic juvenile polyps had K-ras mutations (14%) and there was no relationship to dysplasia. p53 gene product overexpression identified by immunohistochemical staining occurred rarely in dysplastic juvenile polyps (2 of 24, 8%). Our results indicate that the multiple genetic alterations involved in usual colorectal neoplasia also play a role in neoplastic transformation of juvenile polyps, predominantly in juvenile polyposis syndrome.

Adenomatous Polyposis Coli↗
PubMed1996

Classification and grading of gastritis. The updated Sydney System. International Workshop on the Histopathology of Gastritis, Houston 1994.

The Sydney System for the classification of gastritis emphasized the importance of combining topographical, morphological, and etiological information into a schema that would help to generate reproducible and clinically useful diagnoses. To reappraise the Sydney System 4 years after its introduction, a group of gastrointestinal pathologists from various parts of the world met in Houston, Texas, in September 1994. The aims of the workshop were (a) to establish an agreed terminology of gastritis; (b) to identify, define, and attempt to resolve some of the problems associated with the Sydney System. This article introduces the Sydney System as it was revised at the Houston Gastritis Workshop and represents the consensus of the participants. Overall, the principles and grading of the Sydney System were only slightly modified, the grading being aided by the provision of a visual analogue scale. The terminology of the final classification has been improved to emphasize the distinction between the atrophic and nonatrophic stomach; the names used for each entity were selected because they are generally acceptable to both pathologists and gastroenterologists. In addition to the main categories and atrophic and nonatrophic gastritis, the special or distinctive forms are described and their respective diagnostic criteria are provided. The article includes practical guidelines for optimal biopsy sampling of the stomach, for the use of the visual analogue scales for grading the histopathologic features, and for the formulation of a comprehensive standardized diagnosis. A glossary of gastritis-related terms as used in this article is provided.

Animals↗
PubMed1995

Eosinophilic esophagitis attributed to gastroesophageal reflux: improvement with an amino acid-based formula.

BACKGROUND & AIMS: Treatment for gastroesophageal reflux may be ineffective in patients with an eosinophilic infiltration of the esophagus. The aim of this study was to investigate whether unremitting symptoms of gastroesophageal reflux and biopsy abnormalities of the esophagus may be associated with the ingestion of certain foods. METHODS: Ten children previously diagnosed with gastroesophageal reflux by standard testing with long-standing symptoms (median, 34.3 months; range, 6-78 months) despite standard antireflux therapies, including Nissen fundoplication in 6 patients, were fed the elemental formulas Neocate or Neocate-1-Plus (Scientific Hospital Supplies Inc., Gaithersburg, MD) for a minimum of 6 weeks. Each child had repeat endoscopy followed by open food challenges. RESULTS: While receiving the formulas, patients had either resolution (n = 8) or improvement (n = 2) of symptoms. On follow-up esophageal biopsy, the maximal intraepithelial eosinophil counts decreased significantly before (median, 41; range, 15-100) to after (median, 0.5; range, 0-22) the formula trial (P = 0.005). Other reactive epithelial changes of the esophageal mucosa also improved significantly. All patients redeveloped their previous symptoms on open food challenges. CONCLUSIONS: Chronic gastrointestinal symptoms and histological changes of the esophagus unresponsive to standard treatments for gastroesophageal reflux were improved by the use of elemental formulas. Symptoms recurred when specific dietary proteins were reintroduced during open food challenges. The mechanism of these observations is unknown.

Adolescent↗
PubMed1995

Cerebral ocular Whipple's disease: a 62-year odyssey from death to diagnosis.

A 47-year-old white man with dementia, supranuclear ophthalmoplegia, and myoclonic ocular and facial jerks died in 1931. The case report in 1936 by Ford and Walsh diagnosed encephalitis. In 1993, we made a clinical diagnosis of Whipple's disease on the basis of the 1936 publication. We restudied the pathologic material and found, in addition to extensive encephalitis, PAS-positive material in only the eye, brain, spinal cord, and pituitary. Electron microscopy demonstrated free and intracytoplasmic microorganisms in the eye and brain. We review the history of cerebral ocular Whipple's disease and the implications from this case, which occurred before the development of antibiotics.

Astrocytes↗
PubMed1994

Effects of Helicobacter pylori infection and gastritis on gastric alcohol dehydrogenase activity.

Sex and age differences in gastric alcohol dehydrogenase activity in relation to abnormalities of gastric histology and Helicobacter pylori infection were determined in 63 patients (32 men and 31 women) undergoing upper endoscopy for gastrointestinal symptoms. No sex difference was found in gastric alcohol dehydrogenase activity. Males older than 50 years had lower enzyme activity than younger males. Patients with H. pylori and/or moderate to severe chronic and acute inflammation and epithelial mucin depletion had lower alcohol dehydrogenase activity in the antrum, but not in the fundus. H. pylori was found more frequently in the older male patients. Antral alcohol dehydrogenase was most decreased in older patients of both sexes with H. pylori infection. In conclusion, H. pylori infection and/or chronic active gastritis are important causes of low gastric alcohol dehydrogenase activity.

Adult↗
PubMed1992

Increased HLA A1 and diminished HLA A3 in lymphocytic colitis compared to controls and patients with collagenous colitis.

Lymphocytic colitis is a newly described chronic diarrheal disorder. Although its etiology is unknown, the possibility has been raised that autoimmunity may play a role in both lymphocytic and collagenous colitis, a similar clinicopathologic illness. The frequencies of HLA class I and class II antigens were examined in 24 white patients with lymphocytic colitis and in 47 white patients with collagenous colitis. Frequencies in these two disorders were compared to control white populations and to each other. An increased frequency of HLA-A1 was noted in 16 of 24 lymphocytic colitis patients (66.6%) compared with 1089 of 3942 controls (27.6%) (P less than 0.005; relative risk 5.2). Furthermore, HLA-A3 was found in decreased frequency in lymphocytic colitis patients: 0 of 24 (0%) compared with 1017 of 3942 controls (25.8%) (P less than 0.05; relative risk 0.0). Collagenous colitis patients had no significant deviation from control frequencies of HLA antigens. In lymphocytic colitis, there was no significant increase in B8 or DR3 antigens, which are found in linkage disequilibrium with A1 and associated with many autoimmune diseases. Moreover, the frequency of autoimmune-associated class I HLA antigens was not increased in lymphocytic colitis. Statistically significant differences existed between lymphocytic and collagenous colitis in HLA-A1, A3, Bw6, and B7 antigen frequencies. The HLA patterns noted previously in other gastrointestinal disorders, including ulcerative colitis and Crohn's disease, were not apparent in lymphocytic or collagenous colitis. HLA typing provides further evidence that lymphocytic colitis is a distinct form of chronic intestinal inflammatory disease associated with HLA class I phenotypes.

Colitis↗
PubMed1992

Association of gastric hypoacidity with opportunistic enteric infections in patients with AIDS.

To determine the relation and possible significance of gastric hypoaciditity to chronic diarrhea in AIDS, patients with and without chronic (greater than 1 month) diarrhea underwent fasting gastric juice pH measurement and microbiologic study and upper and lower endoscopy with biopsy. All 8 patients with diarrhea and high gastric pH (greater than 3; mean, 6.1 +/- 1.0) had gastric bacterial overgrowth (greater than 10(4) bacteria/mL) along with opportunistic enteropathogens in the duodenum or rectosigmoid, but only 1 of 6 patients with diarrhea and gastric pH in the normal range (less than or equal to 3; mean, 1.9 +/- 0.7) had overgrowth or an opportunistic enteropathogen. By contrast, all but 1 of 9 controls (AIDS patients without diarrhea) had normal fasting gastric pH (mean, 2.9 +/- 1.5). Overall, the presence of gastric hypoacidity was associated with identification of opportunistic enteropathogens (P = .035). Thus, gastric hypoacidity is associated with quantitative bacterial overgrowth and opportunistic enteric infections and may be etiologically important in the pathophysiology of the chronic diarrhea seen in some AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1991

AIDS enteropathy: occult enteric infections and duodenal mucosal alterations in chronic diarrhea.

OBJECTIVE: To investigate occult enteric infections and morphologic changes in the small intestine in patients with advanced human immunodeficiency virus (HIV) infection and chronic diarrhea of undefined cause. DESIGN: Case-control study. SETTING: Referral-based clinic and hospital in tertiary care center. PATIENTS: Twenty-two patients with advanced HIV infection (19 with the acquired immunodeficiency syndrome [AIDS], 3 with AIDS-related complex) with chronic diarrhea, selected because of previously negative stool evaluations for bacterial or parasitic pathogens, were compared with 13 patients with advanced HIV infection (9 with AIDS, 4 with AIDS-related complex) without diarrhea by analysis of endoscopic biopsies using light and electron microscopy, viral culture, and morphometric studies. Both groups were convenience samples and had at least 7 months follow-up. MEASUREMENTS AND MAIN RESULTS: Eleven of twenty-two patients with HIV infection and chronic diarrhea but only 1 of 13 patients without diarrhea showed occult enteric pathogens (that is, undetected by routine studies) after extensive evaluation of duodenal and colorectal biopsies. Mycobacterium avium-intracellulare and microsporidia were the most common occult agents in study patients with diarrhea (5 each). Patients with diarrhea and occult enteric infections had greater weight loss (mean, 14.3 kg compared with 6.2 kg; P less than 0.05) and shorter survival (1 of 11 compared with 8 of 11 still alive; P less than 0.004) than those with diarrhea but no identified pathogens (defined as "AIDS enteropathy"). Duodenal morphometry showed decreased villus-to-crypt ratios because of villus atrophy and crypt elongation in HIV-infected patients both with and without diarrhea compared with normal controls (P less than 0.001 for each). All three groups showed comparable frequencies of epithelial mitoses. CONCLUSIONS: Further endoscopic biopsy evaluation of patients with AIDS who had unexplained chronic diarrhea showed an occult infectious cause in half of the cases. However, altered villus and crypt architecture in advanced HIV infection was independent of the presence of diarrhea or enteric infection and therefore did not correlate with AIDS enteropathy. Subnormal epithelial proliferation in response to injury could be a factor, but the underlying cause of the architectural changes remains obscure. We suggest that T-cell dysfunction may play a role.

AIDS-Related Complex↗
PubMed1991

Prominent mononuclear cell infiltrate is characteristic of herpes esophagitis.

Diagnosis of herpes esophagitis is often difficult since the characteristic nuclear inclusions and/or multinucleate giant cells of herpes virus infection may be absent in endoscopic biopsy specimens. We have noted aggregates of large mononuclear cells with convoluted nuclei adjacent to infected epithelium in the exudates of herpetic esophagitis, and postulate that this is a characteristic inflammatory response to the virus. To test this hypothesis, we reviewed biopsies from 22 cases of ulcerative herpetic esophagitis and from 44 control cases of nonherpetic esophageal ulcers (including nine cases of candidal and five cases of bacterial esophagitis) that contained a quantifiable amount of exudate. The estimated percentage of mononuclear cells present in the specimens was ranked independently by two reviewers using coded photomicrographs of exudate. Wilcoxon's rank sum analysis demonstrated significant correlation between presence of herpes and increased mononuclear cells (P less than .0001). Only one of the 22 herpes cases did not show a prominent mononuclear cell infiltrate. Immunoperoxidase studies performed on Hollande-Bouin's-fixed paraffin-embedded material from 11 herpes cases showed strong staining of the mononuclear cells for KP-1 (CD68), indicating that the majority of these cells are macrophages. These findings suggest strongly that aggregates of macrophages are characteristic of the inflammatory response in ulcerative herpetic esophagitis. The presence of these mononuclear cells in a biopsy specimen that initially does not show herpetic inclusions warrants additional studies to rule out herpes virus infection.

Adolescent↗
PubMed1990

Collagenous colitis in setting of nonsteroidal antiinflammatory drugs and antibiotics.

Collagenous colitis is a clinicopathologic syndrome characterized by chronic watery diarrhea and a mucosal inflammatory process with increased subepithelial collagen band on colonic biopsy. This disorder occurs primarily in females, and the etiology is unknown. We report the atypical presentation of collagenous colitis in two older-aged men following prolonged use of nonsteroidal antiinflammatory agents and short-term use of antibiotics. Although one patient had colonic pseudomembranes, neither patient had microbiological evidence of C. difficile toxin or infection. A variety of medications were initially given to these patients without resolution of diarrhea. Only after the diagnosis of collagenous colitis was made and antiinflammatory drugs directed at the colitis given did the diarrhea abate. These cases illustrate an unusual presentation of collagenous colitis with possible implications for pathogenesis.

Aged↗
PubMed1990

Enhancement of human intestinal mast cell mediator release in active ulcerative colitis.

To further define the role of mast cells in the idiopathic inflammatory bowel diseases, mediator release from intestinal mast cells derived from actively inflamed and relatively quiescent areas of ulcerative colitis was studied. It was hypothesized that mast cells in the actively diseased segments would indicate involvement in the disease process by releasing a different profile of mediators than cells in uninflammed tissue. Mast cell-containing suspensions derived from matched segments of 12 ulcerative colitis specimens were compared for responsiveness to the mast cell stimulus goat anti-human immunoglobulin E. Supernatants from challenged cells were analyzed for levels of three mast cell mediators, histamine, prostaglandin D2, and the sulfidopeptide leukotriene C. Mast cells from the actively involved areas released significantly greater amounts of histamine, prostaglandin D2, and sulfidopeptide leukotriene. The difference in histamine release was not a result of greater stores of histamine in the active tissue cells, because the total histamine content of the mast cells from the active areas was not significantly greater. The enhanced release of both preformed and newly generated mediators indicates activation of those cells in the course of the disease and points to the mast cell contribution to the inflammatory process in these disorders.

Adult↗