PubMed Health⌕ Search

Biomedical subjects

H K Yu

Publications and source records attributed to H K Yu.

14 recordsLinked to original sources
PubMed2000

Nasogastric lansoprazole is effective in suppressing gastric acid secretion in critically ill patients.

AIM: To evaluate the effect of nasogastric lansoprazole on acid suppression in critically ill patients. METHODS: Patients were eligible for the study if they had a nasogastric tube in place and had not received acid-suppressive agents for 3 days prior to enrolment into the study. Patients with active gastrointestinal bleeding or a baseline gastric pH > 4.0 were excluded. Patients served as their own controls during a 24 h lead-in period. Lansoprazole 30 mg was administered once daily with water through a nasogastric tube for 2 days. Intragastric pH was measured by continuous 24 h pH-metry for 3 days. RESULTS: Fifteen patients were enrolled into the study. The baseline median 24 h intragastric pH was 2.25 +/- 1.01, and increased to 6.70 +/- 0.82 (P= 0.001) after 2 days of lansoprazole. Mean percentage of time intragastric pH was > or = 4.0 was 25 +/- 13% at baseline, and increased to 84 +/- 14% (P=0. 001) after 2 days of lansoprazole. CONCLUSIONS: Nasogastric lansoprazole 30 mg daily is effective in suppressing gastric acid secretion in critically ill patients.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

The induction of P450-mediated oxidation of all-trans retinoic acid by retinoids in head and neck squamous cell carcinoma cell lines.

All-trans retinoic acid (RA) can be catabolized into polar metabolites by cytochrome P450 (P450) in several tissues including the skin. We examined eight different squamous cell carcinoma (SCC) cell lines to determine their capacity to induce P450-mediated oxidation of RA. Among the eight different cell lines, enhanced catabolism was detected in AMC-HN-1, -2, -5, and -6, whereas it was not found in the cell lines of AMC-HN-3, -4, -7, and -8. It was found that the enhanced catabolism brought on by P450 induction was blocked when RA was added to AMC-HN-6 along with actinomycin D or cyclohexamide. Also, this catabolism was inhibited by ketoconazole. P450-mediated oxidation was detectable within 4 hours of RA treatment, and RA catabolism reached its maximum 16 hours after treatment. P450 was induced by 13-cis-RA, 9-cis-RA, and retinal; however, retinol could not induce P450. In conclusion, P450 can be induced by retinoids in head and neck SCC (HNSCC) cells and the ability of retinoids to induce P450 can serve as an important factor in determining the biological effect of retinoids.

Antibiotics, Antineoplastic↗
PubMed1997

Ambulatory 24-hour esophageal manometry and pH-metry in patients with noncardiac chest pain, but no reflux symptoms.

The aim of this study is to determine the diagnostic value of 24-hour ambulatory esophageal manometry and pH-metry for patients with noncardiac chest pain (NCCP), but no reflux symptoms. Twenty-four hour ambulatory esophageal manometry and pH-metry was performed on 34 patients with NCCP, but no reflux symptoms. The pressure transducers were located 3, 8, and 13 cm above the lower esophageal sphincter (LES) and the pH probes were located 5 and 20 cm above the LES. An event marker was triggered by the patient for chest pain. Only 17 patients (50%) had at least one pain episode (total 81 episodes, range 1-19 episodes per person) during a 24-hour recording. Twenty-one chest pain episodes (26%) occurred during abnormal motility, whereas 4 episodes (5%) were associated with pH < 4, and 10 episodes (12%) had both abnormalities. The majority of chest pain episodes, 46 out of 81 events (57%), did not have any association with motility or pH abnormalities. Five of 7 patients (71%) with reflux-related chest pain and 8 of 11 patients (73%) with dysmotility-related chest pain had symptom association probability > 95%, indicating a significant association between chest pain and esophageal dysfunction. Our conclusion is that ambulatory esophageal manometry and pH-metry is a useful tool in the evaluation of NCCP, but only a few additional patients with reflux-related chest pain could be found in patients without reflux symptoms.

Adult↗
PubMed1993

Kinetic analysis of cellular nucleotides correlated to growth and tPA production in perfusion cultures of human fibroblast cells.

A maximum cell density of 8 x 10(6) viable human fibroblast cells/ml was obtained on microcarriers at a perfusion rate of 0.6 mL/min-a rate which maintained a quasi-steady state. The maximum tPA production was approximately 1.2 micrograms/ml and obtained when the cell density was relatively constant during the later periods of cultivation. Specific UTP and tPA production rates had a correlation factor of 0.85, and cell growth to oxygen consumption had an 0.92 correlation factor. ATP generation was strongly correlated to glutamine consumption, with a lower correlation to oxygen utilization.

Adenosine Triphosphate↗
PubMed1989

[Preliminary study on red cell immune adherence inhibitory activities in serums of myasthenia gravis patients].

The serum inhibitory activities on RBC-C3b receptor rosette of healthy individuals were studied in myasthenia gravis (MG) patients. The serum inhibitory activities appeared in 65% of MG patients. The serum inhibitory activities of generalized type MG were higher than those of ocular type MG. It was also found that the serum inhibitory activities were correlated with the RBC-C3b receptor rosette rate and immune complex (CIC). Furthermore, it was identified that the CIC of MG serums possessed the inhibitory activity on RBC-C3b receptor rosette.

Antigen-Antibody Complex↗
PubMed1989

[A preliminary study on immune complexes in myasthenia gravis].

The levels of circulating immune complex from 43 patients with myasthenia gravis (MG) and 50 normal controls were detected by using ELISA based on bovine conglutinin. The levels of circulating immune complex in MG patients were higher than those in normal controls (P less than 0.01). Although the levels of circulating immune complex in generalized type MG were higher than those in ocular type MG, the difference showed no statistically significant. It was found that the levels of circulating immune complex, both generalized type MG and ocular type MG, were higher than those in normal controls respectively (P less than 0.01).

Adolescent↗
PubMed1983

Effects of combined oral contraceptive steroids on pituitary-ovarian function during the menstrual cycle of lactating women.

The object of this study was to investigate the effects of combined oral contraceptives on pituitary-ovarian function during the menstrual cycle of lactating women whose prolactin levels were usually elevated. Five of six lactating women studied were considered to have the normal menstrual cycle which was comparable to the presumptive ovulatory cycle of non-puerperal women. The patterns of serum LH and FSH as well as estradiol and progesterone during the menstrual cycle of lactating women were quantitatively and qualitatively, similar to those of non-puerperal women. Prolactin levels, however, were elevated throughout the cycle of lactating women as compared with those of non-puerperal women. Treatment with combined oral contraceptive steroids abolished a midcycle surge of LH and decreased ovarian steroids during the menstrual cycle of lactating women. Serum prolactin levels were also decreased throughout the cycle treated with contraceptives in lactating women.

Adult↗
PubMed1983

Androstenedione, testosterone, and estradiol concentrations in fetal and maternal plasma in late pregnancy in the sheep.

Fetal and maternal plasma concentrations of androstenedione, testosterone, and estradiol were measured in chronically catheterized pregnant sheep during late gestation, spontaneous term delivery, and premature delivery induced by the infusion of low doses of synthetic ACTH-(1-24) (ACTH) to the fetus at 120-130 days gestation. RIAs employing two different antisera directed at different sites of each molecule were used in combination with Celite column chromatography to ensure the specificity of the hormone measurements. Fetal plasma concentrations of all three hormones were greater than the respective maternal concentration at all periods investigated, except immediately before ACTH-induced delivery when fetal testosterone and estradiol concentrations were lower. These observations further support the hypothesis that delivery in the sheep is associated with the induction of placental 17 alpha-hydroxylase and 17,20-lyase by the increased conversion of progesterone to estrogens. The higher values of androstenedione than of testosterone also support the view that estrone is produced in larger quantities than estradiol and that estrone and estrone sulfate are good endocrine markers of the progress of the endocrine changes occurring immediately before parturition in the sheep.

Androstenedione↗
PubMed1982

Effect of abolition of fetal movement on fetal intravascular PO2 and incidence of tonic myometrial contractures in the pregnant ewe at 114 to 134 days' gestation.

The possibility that fetal movements play a role in the initiation of the bursts of tonic myometrial activity (contractures) that occur throughout the second half of pregnancy in the sheep has been examined by the administration of the curare derivative pancuronium to abolish fetal movement. The duration and frequency of the electromyographic bursts associated with contractures, as well as the increase in intrauterine pressure generated by the contractures, were unchanged. However, within 1 hour of the abolition of fetal movement, fetal jugular venous PO2 was significantly elevated and remained elevated for at least 6 hours. This observation is in keeping with the view that fetal skeletal muscle movement consumes significant amounts of oxygen.

Animals↗
PubMed1979

Imagery in the associative learning of schizophrenics.

The present experiment is similar to Bower's (1970) study on imagery as a relational organizer in paired-associate (PA) learning with normals. Three groups of 20 schizophrenic patients learned three different lists of 30 word-word paired-associates, which used either interactive imagery, separation imagery, or rote repetition encoding. Ss were tested on stimulus recognition and paired-associate recall, given recognition. Differences in stimulus recognition and paired-associate recall were not significant across the three encoding methods. Results suggest that schizophrenics are unable to benefit from imaginal cues to facilitate learning in a manner similar to normals. These results are interpreted as providing additional support for the notion that the schizophrenics' cognitive deficit is associated with the relational organizing process of learning.

Adult↗