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Biomedical subjects

S Yan

Publications and source records attributed to S Yan.

At least 19 recordsLinked to original sources
PubMed1992

Effect of fatigue on diaphragmatic function at different lung volumes.

The transdiaphragmatic pressure twitches (PdiT) in response to single maximal shocks delivered bilaterally to the phrenic nerves were recorded as a function of lung volume when the diaphragm was fresh and when fatigued. All relationships were linear and negatively sloped (all r greater than 0.85). From these relationships PdiT was found to decrease with fatigue more rapidly and to recover more quickly at high than at low lung volumes. Complete recovery of PdiT at all lung volumes was greater than 1 h. Contraction and relaxation rate constants of PdiT did not change significantly with fatigue. We conclude that fatigue affects diaphragm contractility more at high than at low lung volumes and that changes in diaphragm contractility are best reflected in the measurement of PdiT as a function of lung volume.

Adult↗
PubMed1992

Evaluation of human diaphragm contractility using mouth pressure twitches.

Mouth (PmT), esophageal (PesT), and transdiaphragmatic pressure twitches (PdiT) in response to single supramaximal bilateral phrenic nerve shocks were recorded during relaxation between total lung capacity (TLC) and functional residual capacity (FRC) in five normal volunteers. The PmT versus PesT or PmT versus PdiT relationships, which were linearly correlated (all r greater than 0.76), were not affected by diaphragm fatigue and were reproducible on repeated determinations over a period exceeding 1 yr. The PmT versus lung volume relationship was also linear (all r greater than 0.72) and reproducible, and its changes following diaphragm fatigue reliably reflected the changes in diaphragm contractility. We conclude that PmT is a reliable measure of diaphragm pressure-generating capacity in normal individuals and has the potential of providing similar information in patients.

Adult↗
PubMed1992

Mitochondrial DNA content and mitochondrial gene transcriptional activities in the early development of loach and goldfish.

The mitochondrial DNA (mtDNA) content of the mature eggs and embryos of loach and goldfish at early developmental stages were detected by means of dot hybridization. The transcription of mitochondrial cytochrome oxidase subunit I and II (COI and COII) genes during their early development was also detected by Northern hybridization. The experimental results showed that the mtDNA content of the mature egg as well as that of the embryos during the period from fertilized egg up to hatching stage in both fishes is maintained at a constant level, giving an average value of 7.40 x 107 molecules or 1.33 ng for every embryo in loach and an average value of 1.87 x 10(8) molecules or 3.31 ng for every embryo in goldfish. In both fish embryos, the COI and COII transcripts declined gradually after fertilization until late-blastula stage and then increased in early gastrula stage. This indicated that the transcription of mitochondrial genomes of these two freshwater fishes, which belong to different families, might be activated at the beginning of gastrulation. The steady-state amounts of mitochondrial messenger transcripts existing in the embryos during the early development in both fishes seemed to be regulated by both their half-lives and the transcriptional level of the mitochondrial genomes. The results showed that the transcription of the mitochondrial genome in the early developmental process in loach and goldfish was not regulated by a gene dosage mechanism.

Animals↗
PubMed1991

Contractile properties of the human diaphragm during chronic hyperinflation.

BACKGROUND: In patients with chronic obstructive pulmonary disease (COPD) and hyperinflation of the lungs, dysfunction of the diaphragm may contribute to respiratory decompensation. We evaluated the contractile function of the diaphragm in well-nourished patients with stable COPD, using supramaximal, bilateral phrenic-nerve stimulation, which provides information about the strength and inspiratory action of the diaphragm. METHODS: In eight patients with COPD and five control subjects of similar age, the transdiaphragmatic pressure generated by the twitch response to phrenic-nerve stimulation was recorded at various base-line lung volumes, from functional residual capacity to total lung capacity, and during relaxation and graded voluntary efforts at functional residual capacity (twitch occlusion). RESULTS: At functional residual capacity, the twitch transdiaphragmatic pressure ranged from 10.9 to 26.6 cm of water (1.07 to 2.60 kPa) in the patients and from 19.8 to 37.1 cm of water (1.94 to 3.64 kPa) in the controls, indicating considerable overlap between the two groups. The ratio of esophageal pressure to twitch transdiaphragmatic pressure, an index of the inspiratory action of the diaphragm, was -0.50 +/- 0.05 in the patients, as compared with -0.43 +/- 0.02 in the controls (indicating more efficient inspiratory action in the patients than in the controls). At comparable volumes, the twitch transdiaphragmatic pressure and esophageal-to-transdiaphragmatic pressure ratio were higher in the patients than in normal subjects, indicating that the strength and inspiratory action of the diaphragm in the patients were actually better than in the controls. Twitch occlusion (a measure of the maximal activation of the diaphragm) indicated near-maximal activation in the patients with COPD, and the maximal transdiaphragmatic pressure was 106.9 +/- 13.8 cm of water (10.48 +/- 1.35 kPa). CONCLUSIONS: The functioning of the diaphragms of the patients with stable COPD is as good as in normal subjects at the same lung volume. Compensatory phenomena appear to counterbalance the deleterious effects of hyperinflation on the contractility and inspiratory action of the diaphragm in patients with COPD. Our findings cast doubt on the existence of chronic fatigue of the diaphragm in such patients and therefore on the need for therapeutic interventions aimed at improving diaphragm function.

Aged↗
PubMed1991

[A case-control study of ulcerative colitis].

In order to evaluate the epidemiological characteristics of ulcerative colitis, we conducted a matched case-control study of ulcerative colitis. Fifty patients with ulcerative colitis diagnosed at three hospitals in Kyoto, Osaka and Hyogo Prefectures in Japan during 1984 and 1987 were interviewed about their habitual and pre-illness diets, personal habits, past histories and family histories. The results were compared to those for fifty healthy controls who were matched for sex and age (+/- 2 years) and participated in health-screening examinations in Kyoto or Osaka during the same period. Frequent intake of rice (4 or more bowls a day), bread (3 or more times a week), and green tea (7 or more cups a day) significantly increased the relative risk of ulcerative colitis. However, a past history of appendectomy was negatively correlated with the disease. There were no relationships between ulcerative colitis and consumption of animal foods and tobacco.

Adolescent↗
PubMed1991

[General anesthesia with sevoflurane and vecuronium for patients with dystrophia myotonica and progressive muscular dystrophy].

A 9 year old male previously diagnosed as progressive muscular dystrophy whose serum CPK5430IU.l-1 was very high received general anesthesia. Before anesthesia, dantrolene sodium 2 mg.kg-1 was given. Anesthesia was induced with thiamylal 100 mg and vecuronium bromide 3 mg. Anesthesia was maintained with sevoflurane (0.5%) in nitrous oxide (66%) and oxygen (33%). The course of anesthesia was uneventful. The operative time was 80 minutes. At the end of the operation, the patient recovered smoothly from anesthesia. A 46 year old female with dystrophia myotonia also received general anesthesia. The patient was diagnosed as having this disease 26 years previously. Preoperatively, the patient was suspected to have cardiac damage. Anesthesia was induced with thiamylal 100 mg, fentanyl 100 micrograms, midazolam 5 mg and vecuronium bromide 4 mg, and maintained with sevoflurane (1.0%) in nitrous oxide (66%) and oxygen (33%). Anesthesia was uneventful, but at the end of the operation, the patient could not breath fully by herself. She was placed on a ventilator and observed carefully. The endotracheal tube was removed 150 minutes after the induction of anesthesia. In these two cases, sevoflurane and vecuronium bromide were used safely.

Anesthesia, Inhalation↗
PubMed1991

[Effect on cerebral blood flow of midazolam during modified neurolept-anesthesia].

Midazolam (0.2 mg.kg-1) was administered to ten patients undergoing neurosurgical operation and its influence on CBF was studied under modified NLA. Simultaneously, the plasma concentration of midazolam was measured. Heart rate and mean arterial blood pressure showed no significant changes after injection in comparison with the control. Cerebral blood flow (CBF) decreased for about 15-20% after 5 minutes, 10 minutes and 15 minutes in comparison with the control. However, 30 minutes later, CBF showed a trend to return to the control. This change in CBF is related to the changes of cerebro-vascular resistance. We applied cerebral oxygen extraction fraction (OEF) to evaluate cerebral metabolism. OEF was constant, showing no significant changes. It is concluded that cerebral oxygen consumption (CMRO2) has decreased together with the decrease in CBF. The plasma concentration of midazolam was 250-300 ng.ml-1 or greater after 5 minutes, 10 minutes and 15 minutes. We think that the sedative dose of midazolam can also sufficiently reduce CBF and CMRO2. The results suggest that midazolam is a safe and effective agent to use for anesthesia and provides adequate sedation for patients with intracranial hypertension.

Adolescent↗
PubMed1991

[Two biotin-labeled probes of gentamicin resistance genes].

A 2.0 kb BamHI-HindIII fragment of pDG0103 from Australia containing gentamicin 2"-o-adenylytransferase [ANT(2")] gene and a 4.9 kb PstI-EcoRI fragment of pBY102 were recovered from low-temperature-melting agarose by the slot method. Both fragments were labeled with biotin-7-dATP by nick translation with a commercial kit. The result of colony and Southern hybridization was that: the 2.0 kb probe from Australia hybridized with that containing ANT(2") from America, while no hybridization occurred between the 2.0 kb probe and the 4.9 kb probe constructed in our lab. Furthermore, the above two fragments were used as probes for detection of 106 strains of gentamicin resistant Enterobacteriaceae. It revealed that there were more than one gentamicin resistance gene in the tested strains.

Biotin↗
PubMed1990

[Inhibitory effect of liuwei dihuang decoction on induced mutation and spontaneous tumor].

Anti-mutagenic activity was evaluated with micronuclear test. It appeared to be same between the result of mice treated with 10 g/kg Liuwei Dihuang decoction (LWDHd) for 3 days and that with 34.5 g/kg for 10 days. All the permillages of micronuclear appearance of treated groups were less than that of controls. The intercept (A) value of dose-effect curve were 12.7 and 9.4 as treated with cyclophosphamide (Cy) alone, but 1.2 and 3.2 as orally administered with LWDHd before injecting Cy. It showed that LWDHd could inhibite mutagenic activity of Cy. The affection of LWDHd on spontaneous tumorigenesis was observed in LACA mice. The tumor incidence rate was 9.0% in the control mice observed for 60 weeks, but 5.0% in the animal feeding LWDHd in food. The tumor incidence rate of big dose group was 1.0% and the difference was significant between it and that of the control (P less than 0.01).

Animals↗
PubMed1989

[A study of factors in medical insurance records associated with participation in health examinations].

Factors in medical insurance records of two groups classified as participants and nonparticipants in a multiphasic health examination (MHE) conducted in a rural town in Kyoto prefecture were compared. The purpose of this study was to clarify how the conditions of medical care influenced the participation in the MHE. The factors were days of consultation, total insurance points and days of consultation classified by specific disease and the area of the medical facility. Participants were examined at least once in 1987-1988 and nonparticipants were never examined in the corresponding period. The data were obtained from the medical insurance records of outpatients for the period from April 1986 thru March 1987. The medical care bills of 170 males and 201 females aged 30-69 were randomly sampled from National Health Insurance records (unit = family), and those of 55 males and 88 females aged 70 and over were from the Medical Service for the Aged (unit = person). These samples were about one forth of target population respectively. Both older participants and older nonparticipants of both sexes had more consultation days and more total insurance points than the corresponding younger subjects. Nonparticipants of both sexes aged 70 and over had more consultation days and more total insurance points than participants; female nonparticipants aged 50-69 had slightly more consultation days and those aged 30-49 also had more insurance points. Nonparticipants tended to have previous medical care for hypertension or ischemic heart disease, which the MHE is responsible for discovering.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[A socio-medical study of adult diseases related to the life style of Chinese in Japan].

This study was conducted to investigate the relationship between life style factors and adult disease for Chinese living in Japan. The mortalities of major cancers and other major diseases of Chinese in Japan were compared with those of Japanese by calculating Standardized Mortality Ratios (SMR) for the Chinese using death rates in the Japanese population the standard. The life style data on smoking, drinking and dietary habits for Chinese in Japan were collected by self-administered questionnaire surveys, and age-adjusted proportions were calculated with the truncated world population as the standard. Then the corrected indexes on life style for Chinese in Japan were compared with those of Japanese. The results are summarized as follows: 1. The mortality rates of heart disease, diabetes mellitus, hypertensive disease, liver cirrhosis, rectum cancer, liver cancer (both sexes), lung cancer (females), breast cancer and cerebrovascular disease (females) for Chinese in Japan were higher than those for Japanese, but the rates of stomach cancer, pancreas cancer (both sexes), uterus cancer (females) and cerebrovascular disease (males) were lower than those for Japanese. 2. The prevalence of current smokers for Chinese males in Japan was lower than that of Japanese, and that of females was higher than that of Japanese. The prevalence of non-smokers for Chinese males was higher than that of Japanese, and that of females was lower than that of Japanese. 3. Although the prevalence of regular drinkers for Chinese of both sexes in Japan were lower than that of Japanese, the prevalence of heavy drinkers who drank over 80 ml of ethanol every day for Chinese males was higher than that of Japanese males. 4. Significant differences were not found in the prevalences of frequent consumers of meat, milk, eggs, fish, other vegetables and food using oil between cooks and non-cooks of Chinese of both sexes in Japan. 5. The age-adjusted prevalences of frequent meat and milk consumers for Chinese in Japan were higher than those of Japanese in both sexes, but those of frequent pickled vegetable and MISO soup consumers were lower than those of Japanese. The dietary pattern of Chinese in Japan was different from that of Japanese with intakes of much fat and less salt. 6. It is assumed that the mortalities due to adult disease for Chinese in Japan are related to their heavy drinking and to their dietary habits.

Adult↗
PubMed1989

[Cochlear aqueduct].

The morphology and structure within the cochlear aqueduct have been investigated on the basis of a histological analysis of 234 temporal bones ranging from 12-week old to adult. Barrier membrane was found in 28.6% of the temporal bones examined, and fibrous reticular tissues of the inner opening of the cochlear aqueduct in 38.1% of the temporal bones. No any tissue in the inner opening of the cochlear aqueduct was seen in 33.3%. Periotic duct was filled with loose reticular tissue. The clinical significance of contents in the cochlear aqueduct was discussed.

Adult↗