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Biomedical subjects

M Y Ho

Publications and source records attributed to M Y Ho.

17 recordsLinked to original sources
PubMed1992

Direct high-performance liquid chromatographic separation of enantiomeric peptidoleukotriene antagonists.

Enantiomeric peptidoleukotriene antagonists, SK&F R-106203 and SK&F S-106203 can be effectively separated on a cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phase. The utility of this chiral high-performance liquid chromatographic method in assigning absolute stereochemistry to SK&F S-106203-Z2, a non-crystalline amorphous compound which is not amenable to single crystal X-ray analysis, is demonstrated by correlation with the absolute configuration determined crystallographically for a second salt form.

Chromatography, High Pressure Liquid↗
PubMed1992

Neuropeptide gene expression in transgenic animals.

Transgenic animal techniques offer today's neuroscientist the ability to experimentally manipulate neurosecretory systems with a precision undreamt of by our predecessors. The range of techniques now available, building as it does on our growing knowledge of physiological systems at the inter- and intercellular level, allows us to critically define molecular lesions and ask about their consequences to the whole organism. Neuroscientist should grasp the opportunities afforded by these recent developments.

Animals↗
PubMed1991

Intracellular pH and catecholamine secretion from bovine adrenal chromaffin cells.

To study the role of intracellular pH (pHi) in catecholamine secretion and the regulation of pHi in bovine chromaffin cells, the pH-sensitive fluorescent indicator [2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein] was used to monitor the on-line changes in pHi. The pHi of chromaffin cells at resting state is approximately 7.2. The pHi was manipulated first by incubation of the cells with NH4+, and then the solution was replaced with a NH4(+)-free solution to induce acidification of the cytoplasm. The pHi returned toward the basal pH value after acidification within 5-10 min in the presence of Na+ or Li+, but the pHi stayed acidic when Na(+)-free buffers were used or in the presence of amiloride and its analogues. These results suggest that the pH recovery process after an acid load is due to the Na+/H+ exchange activity in the plasma membrane of the chromaffin cells. The catecholamine secretion evoked by carbachol and Na+ removal was enhanced after the cytoplasm had been made more acidic. It appears that acidic pH favors the occurrence of exocytosis.

Adrenal Medulla↗
PubMed1989

Malignant mesothelioma in infancy.

Malignant mesothelioma in infancy has rarely been reported in the literature. A 19-month-old female infant with massive malignant epithelial mesothelioma of the pleura underwent postmortem examination. Histochemical study confirmed the diagnosis by revealing acid mucosubstance in the tumor, which was removed by hyaluronidase. The tumor cell had clear cytoplasm that was positive for periodic acid-Schiff staining, which could be totally abolished by diastase. This correlated well with the electron microscopic finding that there had been massive accumulation of glycogen in the cytoplasm. There was no information about environmental exposure to asbestos.

Adenocarcinoma↗
PubMedDate not supplied

Liveborn trisomy 22: report of one case.

A case of trisomy 22 liveborn female baby with multiple congenital anomalies is described. Physical manifestations included failure to thrive, hypotonia, pre-auricular sinus, low set ears, hypertelorism, posterior low hair line, micrognathia, cleft palate, congenital heart disease, imperforated anus with anovulvar fistula, contracted pelvis and bilateral rocker-bottom feet. The infant died at two months of age. Cases of trisomy 22 usually present with many severe malformations, and they rarely survive to term. A review of the literature is presented to delineate this chromosome disorder.

Adult↗
PubMedDate not supplied

[Complications in the use of mechanical ventilator in newborns: one year's experience].

A retrospective study was undertaken of 175 patients (119 males, 56 females) admitted to the neonatal intensive care unit of Mackay Memorial Hospital during the period of July 1, 1985 to June 30, 1986 who received mechanical ventilation during their stay at the hospital. Upon reviewing the clinical histories of these patients, the complication rate of mechanical ventilation was 31.9%. The percentages of each complication were: pneumothorax 50.0%, pneumomediastinum 5.2%, pulmonary interstitial emphysema 1.7%, atelectasia 13.8%, pneumonia 13.8%, chronic lung disease 13.8%, nasopharyngeal infection 1.7%. Survival rate of these ventilated patients with or without complication was not significant statistically (69.2% vs 65.6%). However, with regard to the hospital course, cases with complication had a significantly longer duration of ventilator usage, hospital stay and oxygen usage than uncomplicated cases. In conclusion, experienced personnel are needed to supervise the use of mechanical ventilation in neonates, and a team of well-trained nurses working in the neonatal intensive care unit are essential to minimize complications.

Chi-Square Distribution↗
PubMedDate not supplied

[Pharmacological closure of symptomatic PDA in premature infants using indomethacin].

When left to right shunting through the ductus arteriosus is of a degree contributing to the cardiopulmonary problems in a premature infant, the condition is clinically termed symptomatic PDA. It is also generally agreed that symptomatic PDA if left untreated is a significant cause of increased morbidity and mortality. Studies have also concluded that all infants with symptomatic PDA who are prematurely born and/or ventilator dependent should be considered candidates for ductal closure by either pharmacological or surgical mean. Over a period of approximately 2 1/2 years, 22 premature infants with symptomatic PDA have been treated here with powder form indomethacin. The one course success rate was 68%. Thereafter, in another 2 1/2 years, 33 cases were selected for whom a liquid form was used instead. The success rate was 70%. Indomethacin is better given by an intravenous route. However, if the intravenous form is not available, using the liquid form by mouth or via the naso-gastric tube is a good substitute.

Ductus Arteriosus, Patent↗
PubMedDate not supplied

Periventricular leukomalacia in infancy: ultrasonic diagnosis and neurological outcome.

During the more than five years from January 1984 to June 1989, twenty-four patients with definite or probable cystic periventricular leukomalacia (PVL) were diagnosed by cranial ultrasonography at Mackay Memorial Hospital. The 24 patients were divided into two groups. Group A comprise two boys and four girls who received longitudinal sonographic follow-ups for leukomalacia. Of these six patients, five were premature and all suffered from severe perinatal insults. In each case, sequences of developmental cystic PVL were observed by serially scanning the brain. High echogenicity was discovered during the initial stages (2 to 7 days) in the periventricular area, and cystic formations were observed between the age of 18 and 60 days. Clinically, only one patient developed normally; four had severe motor dysfunction and poor motor development; and one was lost during follow-up, Group B was composed of 18 patients who visited the out-patient clinic for psychomotor retardation evaluation, and were found through ultrasound to have or possibly have cystic PVL formations at various stages. The clinical work-up revealed that 12 had spastic quadriplegia; 2 had hemiplegia; 3 had spastic displegia; and 1 case had hypotonic cerebral palsy. In infants, PVL is considered to be a much more reliable and important prognostic predictor than intraventricular hemorrhage. Consequently, it is crucial that physicians should screen patients at high risk for PVL, especially those with perinatal insults.

Cysts↗
PubMedDate not supplied

[Kawasaki disease complicated with hemorrhagic enteritis mimicking intestinal obstruction: report of one case].

A 6-month-old little boy presented with fever and cervical lymphadenopathy for four days. On admission, he was found to have conjunctival congestion of both eyes, reddened and fissured lips, straw-berry tongue, macular rash at the trunk and erythematous change on the BCG injection site. The diagnosis of Kawasaki disease was made and aspirin therapy (100 mg/kg/day) was started. On the 3rd hospital day, he developed abdominal distention, jaundice, poor activity and tachypnea. Bowel sound was silent on auscultation. Nasogastric tube was inserted for decompression and bilious material was drained out continuously. In addition, bloody, mucoid stool passage was noted. An abdominal radiography revealed dilatation of the small bowel and paucity of the colon gases. On the abdominal ultrasound, hydrops of gallbladder, marked ascites and silent and dilated bowel loops were found. Despite of supportive care, abdominal symptoms persisted and condition deteriorated. Laparotomy was done on the following day. At operation, it was found that the patient developed severe petechia on the long segment of small intestine from 15cm distal to the Treitz ligament to ileocecal valve and some fibrin plagues on the terminal ileum at 25cm proximal to the ileocecal valve were also found.

Enteritis↗