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Biomedical subjects

E H Cheng

Publications and source records attributed to E H Cheng.

29 records · Page 2Linked to original sources
PubMed1990

Multiple gastrointestinal tract diverticula.

Simultaneous occurrence of gastrointestinal diverticula at multiple sites in a single patient is unusual. We report a patient with a Zenker's, a mid-esophageal, a gastric, and multiple colonic diverticula. The presence of multifocal gastrointestinal diverticula suggests as one possible etiology congenital weaknesses in the bowel wall, since esophageal manometry and histology of a resected diverticulum did not reveal any abnormalities other than gastroesophageal reflux.

Aged↗
PubMed1989

Chloride secretory response of cystic fibrosis human airway epithelia. Preservation of calcium but not protein kinase C- and A-dependent mechanisms.

Because the defect in Cl- secretion exhibited by cystic fibrosis (CF) epithelia reflects regulatory rather than conductive abnormalities of an apical membrane Cl- channel, we investigated the role of different regulatory pathways in the activation of Cl- secretion in freshly excised normal and CF nasal epithelia mounted in Ussing chambers. A beta agonist (isoproterenol [ISO]), a Ca2+ ionophore (A23187), and a phorbol ester (PMA) were all effective Cl- secretagogues in normal human nasal epithelia. Agonist addition studies indicated that ISO and PMA but not A23187 may share a common regulatory pathway. In contrast, only A23187 induced Cl- secretion in CF epithelia. Bradykinin raised cytosolic Ca2+ and induced Cl- secretion in both normal and CF tissues, indicating that receptor gated Ca2+ dependent Cl- secretory mechanisms were preserved in CF. The defective Cl- secretory response in CF epithelia to ISO and PMA did not reflect abnormalities in cAMP-dependent (A) and phospholipid Ca2+-dependent (C) kinase activities. We conclude that (a) a Ca2+-sensitive mechanism for regulating Cl- secretion is maintained in CF airway epithelia, and (b) a regulatory pathway shared by two distinct protein kinases is defective in CF, indicating that the CF genetic lesion is not tightly coupled to a single (e.g., cAMP dependent) regulatory mechanism.

1-Methyl-3-isobutylxanthine↗
PubMed1989

Prevalence of Campylobacter pylori in esophagitis, gastritis, and duodenal disease.

The relationship between the presence of Campylobacter pylori and esophagitis was studied in patients undergoing paired biopsies of distal esophagus and gastric antrum during esophagogastroduodenoscopy. Biopsy specimens were examined for urease activity and for the presence of C pylori by culture and by histologic examination of hematoxylin-eosin- and Warthin-Starry-stained sections. Sixty-two patients were entered into the study. All esophageal biopsy specimens, regardless of histologic findings, were negative for the presence of C pylori by urease test, culture, and histologic examination. Of 35 patients with normal esophageal biopsy specimens, 11 (31%) had antral specimens that were positive for C pylori, while 11 (41%) of the 27 patients with esophagitis had antral specimens that were positive for the organism. Campylobacter pylori was detected in 14 (70%) of 20 patients with chronic gastritis, in 8 (67%) of 12 patients with endoscopically documented duodenal ulcers and erosions, but in only 3 (33%) of 9 patients with endoscopically defined duodenitis. We conclude that histologic esophagitis is not associated with increased prevalence of either gastric or esophageal C pylori. The well-described association of chronic gastritis and duodenal ulcers with C pylori was present in our study population.

Adult↗
PubMed1985

Effect of uracil arabinoside on metabolism and cytotoxicity of cytosine arabinoside in L5178Y murine leukemia.

Pretreatment of L5178Y murine leukemia cells with uracil arabinoside (ara-U) enhances the cytotoxicity of cytosine arabinoside (ara-C). This effect is mediated by the cytostatic effect of ara-U, which causes a delay of cell progression through S-phase. Consequently, the specific activity of enzymes that peak during S-phase increases, and deoxycytidine kinase increases 3.6-fold over untreated controls. This allows enhanced anabolism of ara-C to nucleotides, as well as increased incorporation into DNA with ultimate synergistic cytotoxicity. It is postulated that the systemic metabolism of high-dose ara-C to sustained high levels of ara-U in patients with acute leukemia may enhance the activity of subsequent doses of ara-C, and thus contribute to a means for pharmacologic self-potentiation, contributing to the unique therapeutic activity of high-dose ara-C.

Animals↗
PubMed1980

Inhibition of growth of B16 murine malignant melanoma by exogenous interferon.

We previously reported that polyinosinic-polycytidylic acid, a potent interferon inducer, inhibits the growth of B16 malignant melanoma in the C57BL/6 mouse. Two experiments were done to evaluate the effectiveness of interferon in tumor inhibition in vivo. In the first, mice were implanted with melanoma and divided into four groups, according to treatment: interferon preparation; interferon control preparation ("breakthrough fraction"); phosphate-buffered saline control; and murine serum albumin control. Daily, each mouse was given i.p. injections of 200,000 NIH reference units (hereafter called units) of interferon or of one of the control substances. The second experiment was similar to the first, except that bovine serum albumin was an additional control. In both experiments, the average tumor volume in interferon-treated mice was statistically significantly smaller than that of each control group. Mouse interferon preparations also inhibited the multiplication of B16 malignant melanoma cells in culture. This inhibition was statistically significant from interferon levels as low as 5 to as high as 5000 units/ml. The degree of inhibition markedly increased from 5 up to 500 units, the inhibition reaching its maximum at this concentration. The inhibitory effect of interferon was abrogated by anti-murine interferon serum produced in a rabbit. These findings suggest that the in vivo inhibition of the growth of B16 melanoma demonstrated with polyinosinicpolycytidylic acid and with exogenous interferon probably results, at least in part, from a direct effect of interferon on the tumor cells themselves.

Animals↗
PubMed1976

A computer package to facilitate compliance with utilization review requirements.

The Cumberland County CMHC in Fayetteville, North Carolina, developed a series of computer programs to produce the information that is required by area regional utilization review committees. There is a total of eight programs. The first establishes a master file and prints out all the information that has been gathered on all the clients. The other seven programs retrieve various portions of the data stored in the master file. The system does not require elaborate in-house computer equipment. It is easy to operate and benefits clients by enabling clinical staff to spend less time on documentation and more time on direct treatment.

Community Mental Health Services↗