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Biomedical subjects

K Liu

Publications and source records attributed to K Liu.

At least 487 records · Page 27Linked to original sources
PubMed1990

The reverse-flow posterior tibial artery island flap: anatomic study and 72 clinical cases.

Based on anatomic, dye injection, and angiography observations since 1984, 72 patients with tissue defects of the foot (due to injury or surgery) have been reconstructed using a reverse-flow posterior tibial artery island flap. In the 72 patients, etiology has included extensive crushing (40 patients), burn scars (10 patients), and tissue loss following tumor or chronic ulcer resection (22 patients). Only two flaps developed necrosis. The survival rate was 97.2 percent, including seven cases of distal marginal necrosis. This procedure, therefore, offers a useful alternative in the repair and reconstruction of extensive tissue defects in the foot, whether caused by accidental injury or surgery.

Adolescent↗
PubMed1990

[Preliminary report on various symptoms of chronic hepatitis treated with radix Astragali and its regulative effect on levels of serum hormone].

67 cases of chronic hepatitis were treated with Radix Astragali. After treatment (2-month course), the clinical improvement rates in 38 cases of the Gan-Yu Pi-Xu type and in 26 cases of the Gan-Shen Yin-Xu type were 92.1% and 88.5% respectively, more effective than that of the control group (P less than 0.05). The regulative effect to the levels of serum hormone was observed in the patients of Gan-Yu Pi-Xu type with this medicine. The results showed that the levels of serum T3, E2 (female) and T (male) were increased after treatment (1.40 +/- 1.38 ng/dl, 129.30 +/- 1.23 pg/ml and 496.24 +/- 1.47 ng/dl respectively) than that before treatment (1.22 +/- 1.49 ng/dl, 104.60 +/- 1.45 pg/ml and 398.17 +/- 1.55 ng/dl respectively, P less than 0.05); however, the level of serum PRL (2.75 +/- 4.46 ng/ml) was lower after treatment than that (3.20 +/- 3.82 ng/ml) before treatment (P less than 0.05). No obvious changes were observed in the levels of serum FSH, LH, TSH, T4; T3U and F after treatment.

Adult↗
PubMed1989

The reverse flow ulnar artery island flap: 42 clinical cases.

Based on anatomical and dye injection observations, since 1984 42 cases of hand tissue defects (due to injury or surgery) have been reconstructed using a reverse flow unlar artery forearm island flap. Of the 42 cases, aetiology has included extensive crushing (25 cases), electric saw injuries (7 cases), burn scars (4 cases) and tissue defects following tumour or chronic ulcer resection (6 cases). Only one flap developed necrosis. The survival rate was 97.6%, including 4 cases of distal marginal necrosis. This procedure, therefore, offers a useful alternative in the repair and reconstruction of extensive tissue defects in the hand, whether caused by accidental injury or by surgery.

Adolescent↗
PubMed1989

The effect of nursing home use on Medicaid eligibility.

Presented are results of a descriptive analysis of the effects of nursing home use on Medicaid eligibility status. Data from the 1982 and 1984 National Long-Term Care Surveys were used to track a cohort of disabled elderly persons residing in the community in 1982 over the 2 years that followed. Although 12% spent some time in nursing homes between 1982 and 1984, about 40% was for short stays. In contrast to persons who did not use nursing homes, persons who entered nursing homes had a 4- to 5-fold risk of spending down to Medicaid eligibility.

Aged↗
PubMed1989

Health care costs of older persons with cognitive impairments.

The 1981-1982 National Long-Term Care Channeling Demonstration Project data revealed that the mean annual cost per capita for home and institutional care for cognitively impaired persons was +18,500. The equivalent figure for cognitively intact persons was +16,650. Cognitively impaired persons used nursing homes at twice the rate of cognitively intact persons. Use differences for other health services were slight. A pre- and post-nursing home admission analysis indicated that for the cognitively impaired the annual cost of community care was +11,700, whereas the cost of nursing home care was +22,300.

Aged↗
PubMed1989

Dual bidirectional promoters at the mouse dhfr locus: cloning and characterization of two mRNA classes of the divergently transcribed Rep-1 gene.

The mouse dihydrofolate reductase gene (dhfr) is a housekeeping gene expressed under the control of a promoter region embedded in a CpG island--a region rich in unmethylated CpG dinucleotides. A divergent transcription unit exists immediately upstream of the dhfr gene which is coamplified with dhfr in some but not all methotrexate-resistant cell lines. We show that the promoter region for this gene pair consists of two bidirectional promoters, a major and minor promoter, which are situated within a 660-base-pair region upstream of the dhfr ATG translation initiation codon. The major promoter controls over 90% of dhfr transcription, while the minor promoter directs the transcription of the remaining dhfr mRNAs. The major promoter functions bidirectionally, transcribing a divergent 4.0-kilobase poly(A) mRNA (class A) in the direction opposite that of dhfr transcription. The predicted protein product of this mRNA is 105 kilodaltons. The minor promoter also functions bidirectionally, directing the transcription of at least two divergent RNAs (class B). These RNAs, present in quantities approximately 1/10 to 1/50 that of the class A mRNAs, are 4.4- and 1.6-kilobase poly(A) mRNAs. cDNAs representing both class A and class B mRNAs have been cloned from a mouse fibroblast cell line which has amplified the dhfr locus (3T3R500). DNA sequence analysis of these cDNAs reveals that the class A and class B mRNAs share, for the most part, the same exons. On the basis of S1 nuclease protection analysis of RNA preparations from several mouse tissues, both dhfr and divergent genes showed similar levels of expression but did show some specificity in start site utilization. Computer homology searches have revealed sequence similarity of the divergent transcripts with bacterial genes involved in DNA mismatch repair, and we therefore have named the divergently transcribed gene Rep-1.

Amino Acid Sequence↗
PubMed1989

Ethnic differences in blood pressure, pulse rate, and related characteristics in young adults. The CARDIA study.

This study examined ethnic differences in blood pressure and pulse rate in young adults to see whether the differences, if they exist, can be explained by differences in body mass index, lifestyle, psychological, and socioeconomic characteristics. Data used were from the baseline examination of the Coronary Artery Risk Development in (Young) Adults Study (CARDIA). CARDIA is a longitudinal study of lifestyle and evolution of cardiovascular disease risk factors in 5,116 young adults, black and white, men and women, aged 18-30 years, of varying socioeconomic status. Young black adults had higher mean systolic blood pressure and slightly higher mean diastolic blood pressure than young white adults. For both men and women, the blood pressure differences between blacks and whites tended to be greater for the age group 25-30 than for the age group 18-24 years. Among the variables studied, body mass index, duration of exercise on the treadmill, number of cigarettes smoked per day, and number of alcoholic drinks per week were consistently associated with blood pressure. The blood pressure differences were greatly reduced after adjusting for these variables. Black participants had lower mean pulse rate than white participants. The differences tended to be greater for the age group 18-24 than for the age group 25-30 years. Among the variables studied, only duration on treadmill and number of cigarettes smoked per day were consistently correlated with pulse rate. With adjustment for duration on treadmill, the differences in pulse rate increased. These results suggest that differences in ethnic pattern of blood pressures and pulse rate with age may be due in part to obesity, physical fitness, alcohol consumption, and cigarette smoking.

Adolescent↗
PubMed1989

Studies on circulation rate and flow model for external loop bioreactor.

We performed experiments in an external loop bioreactor 250 mm in diameter and 4500 mm in height. The variation in circulation rate Um was studied over a wide range of surface gas velocities (UG = 0-24.9 cm/s), and a bioreactor flow model was obtained. We developed a new method (i.e., an electrical conductivity tracking system) to measure circulation rate and solve the problem of measuring general circulation resistance. A theoretical formula for Um was derived for use in scaling up the bioreactor: [formula: see text]

Biotechnology↗
PubMed1989

Intraoperative determination of thoracic duct injury with 131I-fat. An experimental study on dogs.

The creation of an experimental animal model of traumatic chylothorax was verified by 131I labelled fat (peanut oil). 15 dogs of 3 groups were administered 131I labelled oil via a gastric tube. The results were compared between the two experimental groups and a control group with nonchylous pleural effusion. Dynamic radioactive studies on the blood and pleural fluid showed that the absorption curve of the dog's blood and chyle to 131I labelled oil was identical regardless of different attitudes, and was also similar to that of the human blood because the peak appeared 4 hours after the administration of 131I labelled oil, at which the radioactivity of chyle reached its maximum, more powerful than that of the blood collected at the same time (P less than 0.01). The 99% confidence limitation of radioactivity of the pleural fluid, and the radioactivity ratio of the pleural fluid to blood in the experimental groups were 1.8-10.5 and 493-2340 cpm respectively. The specific characteristics of chyle was then determined qualitatively according to the quantitative norms. We conclude that the technique is parallel with the normal physiological pattern and seems to be more simple and reliable than the conventional methods for detection of intraoperative injury of the thoracic duct and early diagnosis of postoperative chylothorax.

Animals↗
PubMed1988

Generation of corticosteroid binder IB from binder II by a sulfhydryl dependent renal cytosolic factor.

It has long been debated whether binder IB represents a unique form of the glucocorticoid receptor or is derived from the larger molecular weight form, binder II, by limited proteolysis. Transformed glucocorticoid receptors in kidney, liver and mixed kidney/liver cytosols were examined using anion exchange and gel filtration chromatography. The transformed receptor in liver cytosols chromatographs as binder II on DEAE-Sephadex A-50 anion exchange columns and has a Stokes radius of approx 6.0 nm. The transformed receptor in kidney cytosols chromatographs as binder IB on DEAE-Sephadex A-50 anion exchange columns and has a Stokes radius of 3.0-4.0 nm (3.2 nm on agarose; 3.0-4.0 nm on Sephadex G-100). Using cytosols prepared from mixed homogenates (2 g kidney plus 8 g liver tissue), our experiments show that binder II is converted to a lower molecular weight form (Rs = 3.2 nm on agarose; Rx = 3.9 nm on Sephadex G-100) that is identical to binder IB in its elution position from DEAE-Sephadex anion exchange resin. Identical results are obtained using kidney/liver/cytosols mixed in vitro in which only the hepatic receptor, binder II, is labelled with [3H]TA. These results support the hypothesis that the renal receptor, binder IB, is a proteolytic fragment of binder II and does not represent a polymorphic form of the glucocorticoid receptor. The renal converting activity is dependent on free-SH for full activity but is insensitive to the protease inhibitors leupeptin, antipain, and PMSF. The conversion of hepatic binder II to binder IB in in vitro mixing experiments can be prevented if kidney cytosol is gel filtered on Sephadex G-25 and the eluted macromolecular fraction is adjusted to 10 mM EGTA (or EDTA) prior to mixing with the [3H]TA labelled hepatic cytosol.

Adrenalectomy↗
PubMed1988

CARDIA: study design, recruitment, and some characteristics of the examined subjects.

In 1984, a prospective cohort study, Coronary Artery Risk Development in Young Adults (CARDIA) was initiated to investigate life-style and other factors that influence, favorably and unfavorably, the evolution of coronary heart disease risk factors during young adulthood. After a year of planning and protocol development, 5,116 black and white women and men, age 18-30 years, were recruited and examined in four urban areas: Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota, and Oakland, California. The initial examination included carefully standardized measurements of major risk factors as well as assessments of psychosocial, dietary, and exercise-related characteristics that might influence them, or that might be independent risk factors. This report presents the recruitment and examination methods as well as the mean levels of blood pressure, total plasma cholesterol, height, weight and body mass index, and the prevalence of cigarette smoking by age, sex, race and educational level. Compared to recent national samples, smoking is less prevalent in CARDIA participants, and weight tends to be greater. Cholesterol levels are representative and somewhat lower blood pressures in CARDIA are probably, at least in part, due to differences in measurement methods. Especially noteworthy among several differences in risk factor levels by demographic subgroup, were a higher body mass index among black than white women and much higher prevalence of cigarette smoking among persons with no more than a high school education than among those with more education.

Adult↗
PubMed1988

Education, smoking and non-cardiovascular mortality: findings in three Chicago epidemiological studies.

The interrelationships among education, smoking, and non-cardiovascular (non-CVD) mortality were examined in middle-aged white males from the Chicago Peoples Gas Company Study (PG), the Chicago Western Electric Company Study (WE), and the Chicago Heart Association Detection Project in Industry (CHA). In each study, college graduates had the lowest prevalence of current smokers and the highest prevalence of former smokers. The associations between education and smoking were strongest in CHA, a study with baseline measurements 10-14 years after those of PG and WE and 3-8 years after the US Surgeon General's report on smoking and health in 1964. In PG and WE, the relative risks of non-CVD death for those who did not attend college compared to those who did were 1.50 and 1.38 (95% limits, 1.04 to 2.18 and 0.95 to 2.02). In CHA, the relative risk for those who did not graduate from college compared to those who did was 1.55 (1.17, 2.05). Differences in baseline cigarette smoking could account for only 23-29% of these increased risks. Because the associations between education and non-CVD mortality may have been confounded by changes in smoking status over the course of follow-up in these studies, non-CVD deaths were subdivided into those from causes related to smoking and causes not related to smoking. For smoking-related causes, the relative risk of death for those who did not attend/graduate from college was 1.95 (0.96, 3.95) in WE, 2.13 (1.18, 3.87) in PG, and 2.34 (1.47, 3.84) in CHA, while the relative risks for causes not related to smoking were 1.17, 1.12 and 1.16, respectively. These findings suggest that education is related inversely to non-CVD mortality primarily through smoking and smoking-related causes of death. With smoking becoming increasingly a habit of the less well-educated, these findings underscore the need for smoking prevention and cessation programmes targeted at the lower end of the socioeconomic scale.

Adult↗
PubMed1988

Measurement error and its impact on partial correlation and multiple linear regression analyses.

In studies examining associations between dietary factors and biomedical risk factors, the relations, if they exist, are frequently attenuated by measurement error. Measurement error may be due to a large intraindividual variation and an inadequate number of measurements or to an inaccurate measuring instrument. This paper evaluates the impact of measurement error on partial correlation and multiple linear regression analyses. Quantitative methods are derived to estimate the potential attenuation of associations. The results indicate that when the controlled variables do not have measurement error, but the correlated variables do, the attenuation of the partial correlation coefficient (or multiple regression coefficient) is greater than that of the simple correlation (or regression) coefficient. When both the correlated variables and the controlled variables have measurement error, the partial correlation (or the regression) coefficients can be either increased or decreased.

Cholesterol, Dietary↗
PubMed1988

A comparison of the random-zero and standard mercury sphygmomanometers.

Both the standard mercury sphygmomanometer and the random-zero sphygmomanometer have been used in epidemiological studies and clinical trials. Problems arise in comparing studies since, in addition to other methodological differences, the readings obtained with the random-zero sphygmomanometer have been found to be lower than those obtained with the standard mercury sphygmomanometer. In the present study, blood pressures were measured in 66 subjects to examine the comparability of findings with the two instruments. Trained observers measured blood pressures simultaneously using a double-headed stethoscope and one cuff connected to the two sphygmomanometers. Use of instrument was randomly assigned for each blood pressure measurement; each observer was unaware of the other's blood pressure reading. Readings were lower with the random-zero sphygmomanometer; mean difference ranged from 2.5 to 3.3 mm Hg for systolic pressure and 1.9 to 2.7 mm Hg for diastolic pressure. Digit distributions recorded by the two observers for the standard mercury sphygmomanometer and the random-zero sphygmomanometer were not significantly different for either systolic or diastolic blood pressure. Intraindividual variation was greater with the random-zero sphygmomanometer than with the standard mercury sphygmomanometer. These data do not indicate that one instrument is clearly superior to the other, although in studies where the observer seeks to reduce the bias of multiple readings per person, the random-zero sphygmomanometer may be the more appropriate instrument. Critical to the use of either instrument are careful training, standardization, certification, and periodic recertification of observers.

Adult↗
PubMed1988

Sodium, lithium-countertransport and blood pressure control by nutritional intervention in 'mild' hypertension.

Erythrocyte membrane cation transport was measured in 167 adults completing the fourth year of a randomized controlled trial testing the efficacy of nutrition intervention for treatment of 'mild' hypertension. Intervention objectives consisted of weight loss, moderate sodium restriction, and reduction of alcohol intake. The mean sodium-stimulated lithium-countertransport (LCT) for 35 participants able to maintain normotensive blood pressures for 4 years by nutritional means alone was 0.29 mmol/l cells per h compared with 0.38 for the 48 subjects requiring represcription of drugs (P less than 0.01). Weight loss from baseline to year 4 was inversely related to LCT among those who were overweight at baseline (P less than 0.05); reported alcohol intakes were positively related to LCT (P less than 0.05). These findings suggest that blood pressure control by nutrition intervention in 'mild' hypertensives is associated with levels of LCT characteristic of normotension. Higher mean LCT in those requiring represcription of drugs was related to lower serum potassium and higher serum triglyceride levels in this subgroup.

Alcohol Drinking↗
PubMed1988

Proximal gastric vagotomy with drainage for obstructing duodenal ulcer.

The optimal treatment for obstructing duodenal ulcer is controversial because of questions about the efficacy of proximal gastric vagotomy (PGV) in controlling the primary ulcer diathesis. Impressed with the theoretic advantages of PGV with drainage as a primary treatment for this problem, we have treated 37 suitable patients by this approach. All patients underwent endoscopic examination and barium meal study that proved the diagnosis. PGV, including division of the gastroepiploic nerves as indicated by intraoperative testing, was followed by Jaboulay gastroduodenostomy (18), Finney pyloroplasty (12), Heineke-Mikulicz pyloroplasty (3), anterior hemipylorectomy (2), duodenoplasty (1), and gastroenterostomy (1). No recurrent ulcers were seen during a mean follow-up of 4.6 years. Three patients had mild early dumping at infrequent intervals. Bilious vomiting, alkaline gastritis, and other postgastrectomy complaints were recorded infrequently. PGV with drainage is a good treatment for the obstructing ulcer and does not have as many morbid risks as alternative operative procedures.

Adult↗
PubMed1988

Patterns of metabolic acidosis in patients with chronic renal failure: impact of hemodialysis.

The type of metabolic acidosis in patients with chronic renal failure was studied prospectively over a three-month period in 32 stable patients on chronic hemodialysis using acetate. All patients had pre-dialysis metabolic acidosis (mean TCO2 = 16.6 +/- 0.4 mEq/l, range 10 to 23 mEq/l). The patterns of metabolic acidosis were defined using the ratio: delta AG/delta TCO2 where delta AG is the increment in plasma anion gap above normal and delta TCO2 the decrement in plasma bicarbonate below normal. The group as a whole showed a mixed hyperchloremic and high anion gap pattern with a mean delta AG/delta TCO2 ratio of 53.3 +/- 7.1%. The individual distribution of patterns ranged from a pure hyperchloremic acidosis (24%) to a pure high anion gap acidosis (30%) with the mixed pattern being the most frequent (46%). An inverse correlation between the TCO2 change (y) during the dialysis procedure and the TCO2 (x) prevailing at the start of dialysis was found by linear regression analysis: y = -0.51x + 11, r = -0.54, p less than 0.01. Thus, before acetate conversion to bicarbonate was fully completed, patients gained bicarbonate during dialysis if TCO2 was less than 21 mEq/l and lost it when the pre-dialysis TCO2 was above this level. On average, the delta AG was reduced to a greater extent than the delta TCO2 so that the delta AG/delta TCO2 ratio fell significantly (from 53 +/- 7.1 to 11 +/- 8.8%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗