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Biomedical subjects

H S Chung

Publications and source records attributed to H S Chung.

At least 19 recordsLinked to original sources
PubMed1993

[One lung ventilation in cases with unsuccessful double-lumen endobronchial intubation].

Three cases of thoracotomy with unsuccessful double-lumen endobronchial intubation were reported. Two were first intubated with an endotracheal tube. In the first patient a Fogarty catheter was inserted alongside the endotracheal tube into the right main bronchus to act as a bronchial blocker. The second patient employed a tracheal tube exchanger to change the endotracheal tube into an Univent tube for one lung ventilation. Nasal fiberoptic intubation was performed in the third case and a Fogarty catheter was passed through the lumen of the endotracheal tube into the left main bronchus as the bronchial blocker. All reported cases were operated with one lung ventilation successfully without the use of a double-lumen endobronchial tube.

Aged↗
PubMed1991

[Effect of shift interval for the clinical nurse with respect to circadian rhythm].

Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep-wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi-continuous shift schedule (sunday off) with a backward direction; that is, morning-evening-night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking time, sleep-wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep-wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep-wake cycle for subjects on the morning, evening, and night shift in both of the shift groups (weekly shift group: lambda = 0.121, p less than 0.01, lambda = 0.112, p less than 0.01, biweekly shift group: lambda = 0.116, p less than 0.01, lambda = 0.084, p less than 0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of Variance↗
PubMed1991

Abnormal muscle response in microvascular decompression of hemifacial spasm.

In 1976, Jannetta et al, suggested that microvascular compression caused by arteries and veins crossing the root entry zone of the facial nerve, was the major etiology of hemifacial spasm (HFS). Surgical treatment has become a major trend. Microvascular decompression (MVD) with teflon patches has a high cure rate. However, the possible occurrence of multiple vessel compression makes it difficult to decide which of these vessels are responsible for the symptom during operation. Recently, a method of abnormal EMG was elaborated upon by Møller and Jannetta in 1987, to ensure the quality of MVD intraoperatively. In this study, we report 6 cases who underwent the procedure successfully. After general anesthesia and muscle relaxation, the abnormal EMG was not suppressed. When the offending vessel was lifted up from the facial nerve, the abnormal EMG disappeared immediately. In each case, postoperative improvement of facial spasm correlated with intraoperative abnormal EMG changes. This method is not only able to guide the surgeon to the vessel that induces HFS but also guarantees the quality of MVD.

Adult↗
PubMed1989

[A study on the effect of cold applications using a sponge bath in healthy adults].

This study was a quasi-experimental research study to test the characteristics of temperature regulation according to sponge bath methods of cold application. Thirteen volunteers were selected from among nursing college students according to an established criteria using a purposive sampling technique. Four different cold application methods were used: (1) tepid water sponge bath at 28 degrees C, (2) 20% alcohol sponge bath at 28 degrees C, (3) 40% alcohol sponge bath at 28 degrees C and (4) tepid water sponge bath at 28 degrees C plus an ice bag to the head. Changes in rectal temperature, mean skin temperature, mean body temperature, heat content change and thermal discomfort during the cold application were measured at 5 minute intervals over a 120 minute period. The data collection period was from Dec. 20, 1988 to Feb. 3, 1989. The data were analyzed using descriptive statistics, simple regression, ANOVA, Duncan's multiple range test and Pearson correlation coefficient using the SPSS-X Program. The results of the study are summarized as follows. Five general hypothesis were tested. Hypothesis 1 that "Change in heat content will be decreased for each cold application method according to the cold application time" was rejected. (tepid water sponge bath: after 10 minutes of cold application, 20% alcohol sponge bath: after 25 minutes of cold application: 40% alcohol sponge bath: after 45 minutes of cold application, tepid water sponge bath plus an ice bag to the head: after 80 minutes of cold application). Hypothesis 2 that "Thermal discomfort will be changed for each cold application method according to the cold application time" was rejected after 5 minutes of cold application. Hypothesis 3 that "Change in heat content will differ among the cold application methods" was accepted except 0-5, 0-10, 0-65, 0-105 and 0-120 minute. This difference showed significance only between sponge bath methods and tepid water sponge bath plus an ice bag to the head. Hypothesis 4 that "Thermal discomfort will differ among the cold application methods" was accepted at 15, 20, 35, 45, 75, 80, 90, 95, 100, 105, 110, 115 and 120 minute of cold application time. This difference showed significance only between sponge bath methods and tepid water sponge bath plus an ice bag to the head. Hypothesis 5 that "The higher the change in heat content, the higher the thermal discomfort during the cold application time" was accepted for between 10-60 and 75 minute of cold application.(ABSTRACT TRUNCATED AT 400 WORDS)

Acclimatization↗
PubMed1989

[The changes of the orofacial muscle activity induced by the lip forces in subjects with normal occlusion].

This study was intended to investigate whether lip exercise affect the activities of the lips, tongue, digastric and masseter muscles and to understand the functional interrelationship between them. As the forces of maximum lip grimace was reduced to slight lip seal gradually, the electromyograph was taken from 9 conscious human adults with normal occlusion in the upper and lower lips, tongue, digastric and masseter muscle using surface electrodes, especially, newly designed subminiature surface electrodes which was attached directly to the tongue. The results were as follows. 1. During induced maximum lip grimace in the mandibular rest position, there're prominent increase of EMG activity in the upper and lower lips, tongue and digastric muscle 1714 mu v, 2787 mu v, 2142 mu v and 623 mu v, respectively, but there was little activity in the masseter muscle, 129 mu v. The force level induced by maximum grimace of the lips was about 110g when the force transducer was positioned between upper and lower lips in the incisor area. 2. As the lip forces were reduced gradually, EMG activities of the lips, tongue and digastric muscles were decreased definitely with certain tendency, but there was no change in the masseteric EMG activity. Above mentioned results suggest that (1) lip exercise can promote the activities of the lips, tongue and digastric muscles but cannot change the activity of the masseter muscle and (2) masseteric muscle activity seems to be independent of the lips and the tongue but digastric muscle activity is related more closely to them through lip exercise in the subjects with normal occlusion.

Adult↗
PubMed1988

The contribution of the rewarded and the non-rewarded stimulus in visual discrimination learning in mice.

The relative contribution of the rewarded and non-rewarded stimulus in the learning of a visual discrimination task in various species is unclear. A number of different parameters have been suggested as influencing the importance of the one over the other, among them the type of reinforcement. Our results show that with both positive reinforcement (using water as reward after a correct choice, and no reinforcement after an incorrect choice) and negative reinforcement (electroshock punishment after an incorrect choice) mice use the position of the incorrect stimulus as a cue for the discrimination. Mice trained by positive reinforcement without the added negative reinforcement of blocking the door on which the incorrect stimulus is projected, do not learn a brightness discrimination task. This suggested that the added negative reinforcement of the closed door had a strong influence on the learning behaviour in our experiments.

Animals↗
PubMed1988

Retained surgical sponge: diagnosis with CT and sonography.

The diagnosis of a retained surgical sponge was made by CT and sonography in four patients. The plain abdominal radiograph was normal in all cases. In each of four cases of gauze granuloma, CT showed a well-defined round mass with a thick wall; internal heterogeneous densities with a wavy, striped, and/or spotted appearance; mottled calcifications; and gas bubbles. Sonography disclosed a well-defined hypoechoic mass containing highly echogenic foci with a strong posterior shadow. In these cases, CT and sonographic findings, together with a history of surgery, permitted the correct preoperative diagnosis of a retained foreign body.

Abdomen↗
PubMed1987

Polycyclic aromatic hydrocarbon quinones and glutathione thioethers as substrates and inhibitors of the human placental NADP-linked 15-hydroxyprostaglandin dehydrogenase.

The human placental NADP-linked 15-hydroxyprostaglandin dehydrogenase catalyzes oxidoreduction at the 9- and 15-positions of many prostaglandins, but its catalytic efficiency (i.e. kcat/Km) for these reactions is low (Jarabak, J., Luncsford, A., and Berkowitz, D. (1983) Prostaglandins 26, 849-868). In the present study, we demonstrate that both K-region and non-K-region o-quinones of polycyclic aromatic hydrocarbons are excellent substrates for this enzyme. These compounds are reduced with kcat/Km values ranging from 3 to 20 X 10(6) S-1 M-1. The glutathione thioethers of menadione and toluquinone are reduced with similar catalytic efficiencies. Furthermore, these substances and certain other glutathione thioethers are potent inhibitors of prostaglandin B1 oxidation ([I50] = 7 X 10(-8) to 5 X 10(-6) M); while several glutathione thioethers also inhibit polycyclic aromatic hydrocarbon quinone reduction ([I50] = 1.7-6.5 microM). These findings raise the possibility that the potential toxicity of quinones of polycyclic aromatic hyrocarbons and other xenobiotic substances may be altered in the placenta by an oxidoreductase for which prostaglandins are relatively poor substrates. They also suggest that the presence in placental tissue of certain glutathione thioethers could influence the reduction of these quinones and other xenobiotic substances by this enzyme.

Female↗
PubMed1977

Abnormalities of the immune system in children with neuroblastoma related to the neoplasm and chemotherapy.

Children with localized and metastatic neuroblastoma were studies to determine their immune status at the time of diagnosis and while they were receiving intensive intermittent chemotherapy; Investigations included leukocyte and differential counts, delayed hypersensitivity response, quantitative serum immunoglobulins, percentages of T and Fc receptor lymphocytes, PHA-induced mitogenesis, and antibody-and PHA-dependent cellular cytoxicity. Abnormalities related to the neoplasm at diagnosis were limited to depressed leukocyte and lymphocyte counts and increased concentrations of serum IgM in patients with metastases to bone marrow and other sites. No abnormalities were observed in those with localized tumors. Intermittent chemotherapy of metastatic neuroblastoma caused immunosuppression. Effects were most marked during five-day courses of chemotherapy; they included abrogation of DH and decreased leukocyte and lymphocyte counts and percentages of Fc receptor lymphocytes. Recovery of DH with partial recovery of leukocyte and lymphocyte counts was observed three weeks, later, prior to the next course, We conclude that both metastatic tumor and chemotherapy cause abnormalities of the immune system in children with neuroblastoma.

Antibodies, Neoplasm↗
PubMedDate not supplied

Determination of nalbuphine in drug abusers' urine.

Nalbuphine, chemically derived from the oxymorphone, is a potent analgesic with narcotic antagonist activity. Because of the limited availability of methamphetamine, the abuse of nalbuphine as an alternative for methamphetamine began in late 1991 in Korea. In this study, the analysis of nalbuphine by gas chromatography (GC) was investigated. Using solid-phase extraction, we analyzed drug abusers' urine samples in order to quantitate nalbuphine by GC after trimethylsilyl derivatization with N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA), trimethylsilylimidazole (TSIM), and 1% trimethylchlorosilane (TMCS) (100:2:5). Nalbuphine and its two metabolites, nornalbuphine and 6-ketonalbuphine, were identified by gas chromatography-mass spectrometry. The ratio of total (i.e., nonconjugated and glucuronide) nalbuphine to nonconjugated nalbuphine ranged from 1.8 to 3.0 in the five drug abusers' urine. The urinary excretion of nalbuphine showed that 93% of nalbuphine was excreted in 6 h after intraperitoneal administration of 10 mg/kg nalbuphine to five rats. No nalbuphine was detected in the urine specimens of rats from 24 to 48 h.

Animals↗