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Biomedical subjects

J Ho

Publications and source records attributed to J Ho.

At least 127 records · Page 7Linked to original sources
PubMed1989

Effect of sucralfate and cimetidine on duodenal ulcer-associated antral gastritis and Campylobacter pylori.

The course of gastritis and Campylobacter pylori was studied in a single-blind randomized trial comparing cimetidine 200 mg three times a day and 400 mg at night and sucralfate 1 g four times a day orally for four weeks in 140 patients with proved duodenal ulcer. At least two antral biopsies were performed during endoscopy before entry and at the end of four weeks. The activity and the degree of chronic inflammation, as assessed histologically by the degree of infiltration of, respectively, polymorphs and chronic inflammatory cells, were graded blindly by two pathologists as nil, mild, moderate, or severe. The density of C. pylori, as assessed after Warthin-Starry stain, was similarly graded. Ulcer-healing rates were comparable in the cimetidine (73.2 percent) and sucralfate (79.7 percent) groups. Improvement of the activity of gastritis occurred significantly (p less than 0.05) more frequently in the sucralfate (33.3 percent) than in the cimetidine group (18.3 percent), and remained so (p less than 0.05) when only patients with healed ulcer were compared. The density of C. pylori decreased significantly in the sucralfate group after treatment (p less than 0.01) but not in the cimetidine group. The 12-month ulcer relapse rates were significantly (p less than 0.05) lower by life-table analysis in patients healed with sucralfate than in those healed with cimetidine and were unaffected by either the density of Campylobacter in either group or the improvement of the gastritis. It is concluded that sucralfate improves duodenal ulcer-associated antral gastritis and decreases the density of C. pylori, and that factors other than bacterial density and antral gastritis may be responsible for the advantage of sucralfate over cimetidine in ulcer relapse.

Adult↗
PubMed1989

Natural history of Campylobacter pylori in duodenal ulceration treated with an H2-antagonist.

Campylobacter pylori has been associated closely with active antral gastritis and duodenal ulcer but its pathogenetic role remains uncertain. The present longitudinal study examined, prospectively, the endoscopic antral biopsies of 45 patients with duodenal ulceration, taken before and after healing of the duodenal ulcer, during remission and at relapse. The biopsies were examined for the activity and degree of chronic inflammation of the gastritis and for the occurrence and density of C. pylori by Warthin-Starry stain. Before treatment the frequency of chronic active antral gastritis was 100% and the occurrence of C. pylori was 97%. Compared with the pre-treatment state, there was no significant change in either the frequency and severity of antral gastritis, or in the occurrence and density of the bacteria in the antral mucosa at the time the duodenal ulcer healed, during remission, or at relapse. The occurrence of the bacteria was significantly more frequent during remission, than at the time when the ulcer had healed initially (P less than 0.05). These results suggest that the bacterium may not play an important pathogenetic role in ulcer healing and relapse, when patients are managed using an H2-blocker.

Adult↗
PubMed1989

Direct detection of Neisseria gonorrhoeae with monoclonal antibodies characterized by serotyping reagents.

A panel of monoclonal antibodies (MAbs) directed to outer membrane protein I were generated with the ultimate aim of detecting Neisseria gonorrhoeae in patient samples by a direct immunofluorescence (IF) test. In an initial evaluation of the sensitivity of these reagents, a cocktail of six IF MAbs recognized 491 (91%) of 540 gonococci isolates from several centers in Sydney, Australia. IF MAbs designated 185 and 228 recognized serovars of WI serogroup and IF MAbs 208, 210, and 312 recognized serovars of WII/III serogroup. IF MAb 198 recognized serovars within both serogroups. Three additional IF MAbs, designated 322, 323, and 330, were then generated by using strains which failed to react with the original MAb cocktail and which belonged to particular serovars. The new cocktail of nine IF MAbs recognized 96% of the gonococcal isolates, which incidentally contained representatives of serovars shown to have a worldwide distribution in previous studies. Although subtle differences were apparent in the reaction patterns found with coagglutination (serotyping) and IF, there nonetheless seems to be merit in the approach of continually evaluating the sensitivity of diagnostic reagents such as MAbs. This is especially true with an organism such as N. gonorrhoeae, which has the capacity to regularly alter the antigenic structure of its outer membrane proteins.

Antibodies, Monoclonal↗
PubMed1989

Giemsa staining for cysts and trophozoites of Pneumocystis carinii.

Although Giemsa staining has been routinely used for the detection of trophozoites and intracystic bodies in smears of bronchoalveolar lavage fluid (BAL) from patients with Pneumocystis carinii pneumonia, it does not normally stain the cyst wall. For detection of the cysts other stains such as toluidine Blue 'O' and methenamine silver must be used as well. Sulphation of smears before staining with Giemsa allows cysts to be visualised, thus enabling a single stain to be used to show all the stages of BAL or sputum, which is particularly useful, considering the increase in the prevalence of P carinii pneumonia in conjunction with the spread of AIDS.

Animals↗
PubMed1988

Fine structure of early human embryos frozen with 1,2 propanediol.

Previous studies by a French group (Fertil Steril 44:645-651, 1985) have shown that two- to eight-cell human embryos can survive slow freeze-thawing with propanediol in a biological freezer. These embryos were assessed for morphological appearance by phase-contrast microscopy. We assessed the structure of 25 frozen-thawed one- to 12-cell embryos, obtained from our in vitro fertilization (IVF) and GIFT programmes, by phase-contrast and electron microscopy, using the same method of cryopreservation. One-fourth of the embryos examined had all cells intact, and more than one-half the embryos had over 50% of their cells well preserved. Some of these embryos had unequal blastomeres and cytoplasmic fragments. Ultrastructural assessment revealed good preservation of fine structure in the intact blastomeres of all embryos and maintenance of cell-to-cell contacts. Most cytoplasmic organelles, cell membranes, and nuclei were well preserved compared to nonfrozen controls. The cells that were cryoinjured showed varying degrees of disorganization of the cell membrane, cytosol, and cellular membranes, including swelling and disruption of the nuclear envelope. Disruption of the zona was somewhat rare. Small cytoplasmic fragments were less prone to cryoinjury than blastomeres. The use of propanediol for embryo cryopreservation seems to be feasible; frozen embryos with more than 50% cells intact have produced 10 pregnancies after embryo transfer (Fertil Steril 46:268-272, 1986). Replacement of 17 frozen embryos in seven patients has resulted in a twin pregnancy in Singapore. However, the effects of freezing on the mitotic spindles of embryonic cells need to be investigated further.

Blastomeres↗
PubMed1988

The effects of ultrarapid freezing on meiotic and mitotic spindles of mouse oocytes and embryos.

Preovulatory mouse oocytes and 2-cell embryos were frozen with dimethyl sulfoxide and propanediol by an ultrarapid method. The survival of frozen oocytes was low (33-34%) compared to that of 2-cell embryos (78-79%) with either cryoprotectant. Development to blastocysts after postthaw culture was about 7-15% for oocytes and 79-80% for the embryos. Ultrarapid freezing preserves cell structure quite well as revealed by electron microscopy, but meiotic oocytes and late 2-cell embryos undergoing mitosis showed evidence of spindle disorganization involving loss or clumping of microtubules resulting in some scattering of chromosomes. Embryos developed from frozen eggs showed clear evidence of micronuclear formation and incomplete incorporation of chromosomal material into main nuclei. These experiments confirm our observations on freezing of human oocytes and show that spindle microtubules are sensitive to freeze-thawing and that cryopreservation could cause chromosomal aberrations during early development. A cautious approach to the introduction of oocyte freezing in human in vitro fertilization (IVF) programs is advocated.

Animals↗
PubMed1988

Delayed pelvic abscess eight years after generalized peritonitis.

Recently, during a locally severe epidemic of gastroenteritis, a young woman presented, with the symptoms prevalent in her community, harboring an intraabdominal abscess. The case is presented along with a discussion of unusual and delayed presentations of abscesses in the literature. Early diagnosis is imperative because of the very significant morbidity and mortality accompanying delayed treatment.

Abdomen↗
PubMed1988

Pancreatic cancer mucin from xenografts of SW1990 cells: isolation, characterization, and comparison to colon cancer mucin.

Mucin has been purified from nude mouse xenografts of SW1990 human pancreatic cancer cells. The mucin was eluted at the void volume of Sepharose CL-4B and was of density greater than 1.3 in CsCl gradients. The isolated mucin had a high content of threonine, serine, and proline, with 31% of the amino acid residues O-glycosylated. The average oligosaccharide composition was NeuAc1.8Fuc0.7Gal2.0GlcNAc1.7GalNAc1.4. Polyclonal rabbit antibodies prepared against the purified mucin recognized primarily mucin polypeptide, and there was extensive immunological cross-reaction between SW1990 pancreatic cancer mucin and LS174T colon cancer mucin. However, using carbohydrate-specific monoclonal antibodies, the two mucins were found to differ. SW1990 mucin had more Lewis, sialyl Lewis, and sialyl Lewis activity, while the colon cancer mucin had more sialyl T antigen. Since pancreatic mucins, whether from normal pancreas or pancreatic cancer, have not previously been well characterized, the availability of SW1990 pancreatic cancer mucin may be useful as a model for studying the expressing of organ-specific or cancer-associated antigens.

Animals↗
PubMed1987

Quantitative determination of porphyrins, their precursors and zinc protoporphyrin in whole blood and dried blood by high-performance liquid chromatography with fluorimetric detection.

Methods for the determination of porphyrins, delta-aminolevulinic acid (ALA), porphobilinogen (PBG) and zinc protoporphyrin of heme biosynthesis in whole blood and dried blood are described. Erythrocyte porphyrins and the precursors ALA and PBG were extracted from whole blood (50 microliter) with 0.3 ml of methanol and 1.5 M hydrochloric acid (2:1, v/v). Zinc protoporphyrin was extracted with an acetone-pyridine-Sterox solution. Other major interfering metabolites were removed by centrifugation. An aliquot of the supernatant was injected onto the reversed-phase C18 column for detection of porphyrins with excitation wavelength at 405 nm and emission wavelength at 630 nm. The mobile phase was 0.1 M phosphate-methanol-tetrahydrofuran (18:30:16, v/v/v), pH 5.38. The ALA and PBG were derivatized with o-phthalaldehyde before injection. The detection excitation wavelength occurred at 330 nm and the emission wavelength at 418 nm. The mobile phase was 0.1 M phosphate-methanol (7.5:5), pH 3.38. For the dried blood specimen of filter paper, two 0.64-cm discs punched out from the blood-impregnated filter paper were placed in a test tube containing 200 microliter of 0.9% saline for 60 min or longer at room temperature and then treated as whole blood.

Chromatography, High Pressure Liquid↗
PubMed1987

Persistence of Campylobacter pyloridis despite healing of duodenal ulcer and improvement of accompanying duodenitis and gastritis.

Campylobacter pyloridis has been associated with antral gastritis and duodenal ulcer. To study the pathogenetic role of these organisms in duodenal ulcer, endoscopic biopsies, two from the first part of duodenum, four from antrum, and four from body and fundus, were taken before and after four weeks of cimetidine treatment (1.2 g/day) from 67 patients with active duodenal ulcer. The biopsies were examined for the presence and severity of any inflammation by two independent pathologists in the absence of any clinical information and for the occurrence and density of Campylobacter pyloridis by culture and Warthin-Starry stain. Before treatment, inflammation was present in 71.1, 100, and 25.8%, while the organisms were present in 34.3, 91.0, and 79.1% of the duodenal, antral, and fundal biopsies, respectively. With complete healing of duodenal ulcer, inflammation was present in 48.9, 98.2, and 30.2%, while the organisms were present in 25, 76.7, and 63.3% of the respective mucosae. With ulcer healing, duodenitis became significantly milder (P less than 0.05). With improvement of gastritis and duodenitis, there was no significant change in the occurrence and density of Campylobacter pyloridis. These findings indicate that healing of duodenal ulcer is not influenced by the presence of Campylobacter pyloridis, which is frequently found in the gastroduodenal mucosa of patients with duodenal ulcer, but does not appear to be associated with mucosal inflammation except in the antrum.

Adult↗
PubMed1986

Detection of delta-aminolevulinic acid, porphobilinogen and porphyrins related to heme biosynthesis by high-performance liquid chromatography.

Two new high-performance liquid chromatographic methods are described for the quantitative determination of porphyrins and their precursors. In our method, sub-nanomole quantities of porphyrins, delta-aminolevulinic acid and porphobilinogen derivatized with ophthalaldehyde were injected onto a C18 reversed-phase column and eluted with 0.1 M monobasic sodium phosphate-methanol-tetrahydrofuran (4:6:3) and detected with a spectrofluorometer. A second reversed-phase system using methanol-tetrahydrofuran-22 mM acetate buffer (15:6:11) was also developed.

Aminolevulinic Acid↗
PubMed1986

Chronic antral gastritis in duodenal ulcer. Natural history and treatment with prostaglandin E1.

The natural history of chronic antral gastritis in relation to the healing of duodenal ulcer and its response to treatment, if any, are unknown. We performed a double-blind controlled trial using an oral prostaglandin E1, misoprostol, in 229 patients with active duodenal ulcer randomized to receive placebo (n = 76), misoprostol 200 micrograms (n = 77), or misoprostol 300 micrograms (n = 76), q.i.d. orally. Healing of duodenal ulcer was assessed biweekly up to 12 wk by endoscopy, during which procedures at least two antral and two fundal biopsy specimens were taken. The activity and the degree of chronic inflammation of gastritis, as assessed histologically by the infiltration of polymorphs and chronic inflammatory cells, respectively, was graded blindly by two pathologists as nil, mild, moderate, or severe. Before treatment, 99% of patients had chronic antral gastritis and 1.5% had chronic fundal gastritis. In the placebo group, healed duodenal ulcer was associated with significantly (p less than 0.01, life table analysis) higher incidence of improvement of the activity of the antral gastritis (nil or mild as endpoint) than unhealed ulcer (30% vs. 4% at week 8). Irrespective of whether duodenal ulcer was healed or unhealed, significantly (p less than 0.01) more patients on misoprostol (50% at week 8) showed improvement (nil or mild as endpoint) than the placebo group. The degree of chronic inflammation of the antral gastritis showed similar significant changes in favor of misoprostol. Smoking and alcohol intake had no significant effect on the improvement of chronic antral gastritis. In conclusion, healing of duodenal ulcer was associated with improvement of the activity of chronic antral gastritis, which, as shown for the first time, could be further enhanced by a therapeutic agent--prostaglandin E1.

Adult↗
PubMed1986

Liver disease in asymptomatic hepatitis B surface antigen carriers.

Fifty-five Chinese healthy asymptomatic Hepatitis Bs Antigen carriers, 49 males and 6 females, were studied over a six year period, 1978 to 1984. Seventeen patients (30.9%) had normal transaminases, and 38 patients (69.1%) had fluctuating levels of transaminases throughout the period of study. 83.6% of patients were below 40 years, and mean age was 29.5 years (range 18 to 49 years). Twenty three patients (41.8%) had liver biopsy, and a spectrum of chronic liver diseases was seen, with Chronic Lobular Hepatitis (CLH) and Chronic Persistent Hepatitis (CPH) being the commonest. Six patients (26.1%) had normal histology, seven patients (30.4%) had CLH, seven patients (30.4%) had CPH, two patients (8.7%) had Chronic Active Hepatitis (CAH), and one patient (4.4%) with Active Cirrhosis (AC). An attempt to correlate the severity of histological changes with the levels of transaminases at the time of biopsy failed to show any definite correlation. However, three patients with transaminases of more than four times normal had severe liver diseases (2 CAH and 1 AC).

Adolescent↗
PubMed1986

Liver disease in blood donors with raised transaminases.

1000 consecutive blood donors had their liver functions studied. 110 donors (11%) were found to have raised ALT of more than twice normal levels. 29 donors had liver biopsies done. Histologically 23 had fatty change, 5 had chronic persistent hepatitis and 1 had liver cirrhosis. Fourteen out of the 23 donors with fatty change also had hypercholesterolemia and hypertriglyceridemia. Viral serology of the 110 donors showed that 3 donors were HBsAg positive, 5 donors were Anti-HAV (IgM) positive and 20 donors were Anti-HBc (IgM) positive. Majority of donors with raised ALT had fatty liver on biopsy with only 6 donors having significant findings of chronic persistent hepatitis and cirrhosis. Serologically, most of the donors (74.5%) with raised ALT had no markers of Hepatitis A, Hepatitis B, CMV or EBV. An interesting finding is the high incidence (18%) of positive, Anti HBc (IgM) in donors with raised ALT.

Adult↗
PubMed1983

Recovery of malignant tumor cells from the right atrium during hepatic resection for hepatocellular carcinoma.

Tumor cells were recovered from the right atrium in three of five patients during hepatic resection for hepatocellular carcinoma. Mechanical factors during blunt mobilization and rotation of the hepatic tumor appeared to be responsible for tumor dislodgement into the venous circulation. Tumor embolization to the lungs may be one of the important reasons for the poor results of surgery in this disease. Two possible technical and therapeutic modifications are suggested to prevent or neutralize this phenomenon.

Blood↗
PubMed1983

Immunoglobulin M and G histoplasmal antibody response in histoplasmosis.

Radioimmunoassays for IgM and IgG histoplasmal antibodies were developed and proved to be specific for their respective immunoglobulin classes, sensitive, and reproducible. Elevated IgM antibodies were detected in 59.8% of patients with histoplasmosis and 7.9% of control subjects. Elevated IgG antibodies occurred in 80.4% of patients with histoplasmosis but in only 12.9% of control subjects. Radioimmunoassay was nearly twice as sensitive as complement fixation for identifying patients with mild, presumably asymptomatic, infection. Of 13 patients with serologic follow-up at least 1 yr later, elevated IgM antibodies cleared, whereas IgG antibodies persisted in 7. In an epidemiologic investigation of a recurrent histoplasmosis outbreak, only the radioimmunoassay was able to prove the hypothesis that construction for a swimming complex was the source of exposure. These assays promise to be useful for clinical and epidemiologic investigations.

Antibodies, Fungal↗