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Biomedical subjects

K Liu

Publications and source records attributed to K Liu.

At least 433 records · Page 24Linked to original sources
PubMed1993

[A comparative study of "angioblastic meningioma", hemangiopericytoma and cerebellar hemangioblastoma].

Forty-nine cases of the so-called "angioblastic meningioma", six cases of cerebellar hemangioblastoma, and four cases of soft tissue hemangiopericytoma were studied with HE, reticulin stainings, and immunohistochemical reaction with Vimentin, EMA, GFAP, S-100, and UEA-1 antibodies. The results showed that among the three subtypes of "angioblastic meningioma", namely, the hemangiomatous (H), the hemangioblastic (AB), and the hemangiopericytic (P) types, (1) type H belongs to true meningioma; (2) most of type P are almost identical with soft tissue hemangiopericytoma and different from true meningiomas, therefore belong to hemangiopericytoma arising from pericytes; however (3) some true meningiomas may appear as hemangiopericytoma histologically; (4) a few of AB are very similar to cerebellar hemangioblastoma and thus should be considered as supratentorial hemangioblastoma, while most of AB are still true meningiomas.

Adolescent↗
PubMed1993

Impact of the Catastrophic Coverage Act and new coverage guidelines on Medicare skilled nursing facility use.

The promulgation of new coverage guidelines and provisions of the 1988 Medicare Catastrophic Coverage Act indicated that Medicare's role in financing nursing home care could expand greatly. This paper presents a facility-level analysis addressing how the policy changes affected the payer mix of subgroups of Medicare-certified skilled nursing facilities (SNFs). Our analysis found that the new policies increased participation of nursing homes in the Medicare SNF program and suggested that the policies expanded both access to the Medicare SNF benefit and the role of public financing for nursing home care. Greater responsiveness to the policies was observed among proprietary SNFs and among those with more beds.

Catastrophic Illness↗
PubMed1993

Modulation of cardiac performance by amiloride and several selected derivatives of amiloride.

Amiloride and its derivatives (benzamil, dichlorobenzamil, 5-(N,N-dimethyl)-amiloride, 5-(N-ethyl-N-isopropyl)-amiloride, (N,N-hexamethylene)- amiloride and 5-(N-methyl-N-isobutyl)-amiloride) are commonly used as selective blockers of Na+/Ca++ exchange or Na+/H+ exchange. Very little information is currently available regarding their effects on cardiac performance. It was observed that addition of amiloride or any of the selected derivatives to the coronary perfusate of the right ventricular wall produced a potent depressive effect on peak developed tension and the rates of tension generation and dissipation. The concentrations at which this occurred are those that are commonly used in ischemia or hypoxia studies. Significantly, the depressive action of the drugs increased with the perfusion duration and never achieved a stable level. An initial, transient positive inotropic effect was observed with some of the drugs. If the drug concentration and perfusion time was limited, the effects were reversible. All of the drugs except amiloride produced extra systoles. The drugs were capable of blocking Ca++ transients in isolated cardiomyocytes but had little effect on intracellular pH. The drugs lengthened the action potential duration and decreased the action potential amplitude and upstroke velocity. Their effects on cardiac performance may involve a complex inhibition of Ca++ influx and K+ efflux in addition to a stimulation of a nonselective cation current. It is concluded that amiloride and its analogs have striking effects on cardiac performance which may be unrelated to their capacity to inhibit Na+/Ca++ or Na+/H+ exchange. In summary, the use of these drugs is not normally recommended in cell or tissue perfusion experiments because of their nonselectivity. However, if the drug concentration and perfusion time is controlled carefully, interpretable data may be obtained in some cases.

Action Potentials↗
PubMed1992

Structure of d(T)n.d(A)n.d(T)n: the DNA triple helix has B-form geometry with C2'-endo sugar pucker.

The polynucleotide helix d(T)n.d(A)n.d(T)n is the only deoxypolynucleotide triple helix for which a structure has been published, and it is generally assumed as the structural basis for studies of DNA triplexes. The helix has been assigned to an A-form conformation with C3'-endo sugar pucker by Arnott and Selsing [1974; cf. Arnott et al. (1976)]. We show here by infrared spectroscopy in D2O solution that the helix is instead B-form and that the sugar pucker is in the C2'-endo region. Distamycin A, which binds only to B-form and not to A-form helices, binds to the triple helix without displacement of the third strand, as demonstrated by CD spectroscopy and gel electrophoresis. Molecular modeling shows that a stereochemically satisfactory structure can be build using C2'-endo sugars and a displacement of the Watson-Crick base-pair center from the helix axis of 2.5 A. Helical constraints of rise per residue (h = 3.26 A) and residues per turn (n = 12) were taken from fiber diffraction experiments of Arnott and Selsing (1974). The conformational torsion angles are in the standard B-form range, and there are no short contacts. In contrast, we were unable to construct a stereochemically allowed model with A-form geometry and C3'-endo sugars. Arnott et al. (1976) observed that their model had short contacts (e.g., 2.3 A between the phosphate-dependent oxygen on the A strand and O2 in the Hoogsteen-paired thymine strand) which are generally known to be outside the allowed range.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Phenomena↗
PubMed1992

Oat products and lipid lowering. A meta-analysis.

OBJECTIVES: To test the a priori hypothesis that consumption of oats will lower the blood total cholesterol level and to assess modifiers and confounders of this association. DATA SOURCES: A computerized literature (MEDLINE) search and the Quaker Oats Co identified published and unpublished trials as of March 1991. Raw data were requested for all trials. STUDY SELECTION: Trials were included in summary effect size estimates if they were randomized and controlled, if a formal assessment of diet and body weight changes occurred, and, if raw data were not received, if there was enough information in the published report to perform calculations. DATA SYNTHESIS: Twenty trials were identified. Using the methods of DerSimonian and Laird, a summary effect size for change in blood total cholesterol level of -0.13 mmol/L (-5.9 mg/dL) (95% confidence interval [CI], -0.19 to -0.017 mmol/L [-8.4 to -3.3 mg/dL]) was calculated for the 10 trials meeting the inclusion criteria. The summary effect size for trials using wheat control groups was -0.11 mmol/L (-4.4 mg/dL) (95% CI, -0.21 to -0.01 mmol/L [-8.3 to -0.38 mg/dL]). Calculation of Keys scores demonstrated that substituting carbohydrates for dietary fats and cholesterol did not account for the majority of blood cholesterol reduction. Larger reductions were seen in trials in which subjects had initially higher blood cholesterol levels (greater than or equal to 5.9 mmol/L [greater than or equal to 229 mg/dL]), particularly when a dose of 3 g or more of soluble fiber was employed. CONCLUSION: This analysis supports the hypothesis that incorporating oat products into the diet causes a modest reduction in blood cholesterol level.

Cholesterol↗
PubMed1992

Genomic typing of hepatitis C viruses present in China.

Hepatitis C virus (HCV) genomic clones were obtained from the serum of Chinese HCV carriers using a polymerase chain reaction-based approach. Consensus sequences were derived from (1) the structural region (nt 1-1543) for one carrier, (2) the hypervariable region V (nt 1156-1233) from four carriers and (3) region V3 from four carriers. Region V3, located in the nonstructural domain NS5 (nt 7066-7137), has been previously shown to be a particularly good marker for the genomic typing of HCV isolates [Inchauspe et al., Proc. Natl. Acad. Sci. USA 88 (1991) 10292-10296]. Comparison of these sequences with sequences from geographically distinct HCV isolates indicates that Chinese HCV strains are closely related to, though distinguishable from, Japanese prototype strains. One amino acid motif, GGAA, located in region V, was found to be conserved only among Chinese isolates. This may define a new subgroup among HCV isolates.

Alanine Transaminase↗
PubMed1992

Random digit dialing in Chicago CARDIA: comparison of individuals with unlisted and listed telephone numbers.

Young adult blacks and whites aged 18-30 years of both low and high educational levels were recruited through random digit dialing to participate in the Chicago, Illinois, portion of a longitudinal study, Coronary Artery Risk Development in Young Adults (CARDIA). Overall, 31% of randomly selected persons eligible to participate had unlisted telephone numbers--about 50% of black men and women and 11% and 17% of white men and women, respectively. There was no difference in proportions of numbers unlisted by educational level, except for white men, who were more likely to have unlisted numbers at a low educational level than at a high educational level. There was no consistent pattern of differences in rates of participation across race, sex, or education subgroups for unlisted and listed numbers, and there were no significant differences for selected health measures, except smoking. The findings suggest that in Chicago, there is a potential bias in estimates of sociodemographic characteristics from the exclusion of unlisted numbers, but it is likely to be insignificant if recruitment is stratified according to race, sex, and education. Within strata, there was little bias with respect to the attributes measured. Ideally, to guard against possible bias, random digit dialing is recommended as the preferred way to select a representative population-based sample.

Adolescent↗
PubMed1992

Endoscopic sphincterotomy in young patients with choledochal dilatation and a long common channel: a preliminary report.

An anomalous elongated pancreaticobiliary common channel encourages reflux up both the biliary tree and the pancreatic ductal system, resulting in progressive choledochal dilatation, cholangitis with ductal calculi, relapsing pancreatitis and malignant change. Transduodenal sphincteroplasty has been used to improve drainage from the abnormal channel. The use of endoscopic sphincterotomy (ES) to establish drainage and minimize the surgical risks is reported in six symptomatic patients with mild choledochal dilatation (common bile duct diameter less than 15 mm), a common channel less than 15 mm in length and a distal stenosis. This was successful in five patients, who have no further symptoms. ES failed in the only patient with an undilated common channel and this patient went on to have open surgery. We believe ES to be safe and effective in the treatment of selected cases of long common channel.

Bile Ducts↗
PubMed1992

Effect of treated infection on microvascular anastomosis.

The effect of established infection with penicillin-resistant Staphylococcus aureus on microarterial and microvenous anastomosis was studied in a rat experimental model. The infection was treated with wound debridement and systemic antibiotics at the time of the surgical procedure. It was found that the patency rate of microarterial repairs at 10-14 days was 95.1%. Veins were less resistant to infection than arteries. Two types of vein involvement were found. These were classified according to the degree of thrombosis resulting from endophlebitis. The patency rate of anastomoses performed on the more mildly infected veins was 56.5% and that on the more severely infected veins was 0%.

Anastomosis, Surgical↗
PubMed1992

Radioiodinated anti-hepatocellular carcinoma (HCC) ferritin. Targeting therapy, tumor imaging and anti-antibody response in HCC patients with hepatic arterial infusion.

Radioimmunoimaging and radioimmunotherapy with radioiodinated anti-(hepatocellular carcinoma ferritin) antibody (131I- or 125I-FtAb) have been applied in patients with primary liver cancer. A total of 41 patients with surgically unresectable hepatocellular carcinoma (HCC) and receiving hepatic artery ligation and cannulation during exploratory laparotomy were treated with this regimen by intrahepatic arterial infusion. Compared with the control group, a decline of serum alpha-fetoprotein (65.7% versus 42.9%) and shrinkage of tumor (68.3% versus 33.9%) were observed in the treated group, and a higher second-look resection rate (31.7% versus 5.1%) and longer survival (1-year: 61.0% versus 37.3%, 3-year: 25.0% versus 6.9%) resulted. The administration of antibody through a hepatic arterial catheter (n = 16) was compared with intravenous injection (n = 17) in terms of the tumor-imaging sensitivity in 33 patients with liver cancer. The results indicated that hepatic arterial infusion was superior to intravenous injection. The sensitivity 7 days after the administration was 100% in the i.a. group and 76.5% in the i.v. group, the uptake ratio of tumor to liver being 1.74 +/- 0.57 in the former and 1.34 +/- 0.29 in the latter. Furthermore, intrahepatic arterial infusion revealed a lower anti-antibody detection rate than intravenous injection (0/14 versus 4/11).

Antibody Formation↗
PubMed1992

Associations of body fat and its distribution with dietary intake, physical activity, alcohol, and smoking in blacks and whites.

Cross-sectional associations between body fat and its distribution and environmental factors influencing energy balance were examined in 5115 young adults. Protein was directly associated with body mass index (BMI) in all race and sex groups (P less than 0.01) after age, education, cigarette-smoking status, alcohol intake, and physical activity were adjusted for. Carbohydrate intake was inversely associated with BMI in males (P = 0.02). Total physical activity was inversely associated with BMI in white women and with skinfold-thickness measures (P less than 0.01) in all groups. Waist-to-hip-circumference ratio (WHCR) was positively associated with total kilojoules (kilocalories) in women, inversely associated with percent of kilojoules (kilocalories) from carbohydrates in whites, grams of crude fiber/4184 kJ (1000 kcal) (except in black men), and physical activity (except in white women). WHCR was directly associated with cigarette smoking except in black men, and with total alcohol intake in men. Beer was consistently associated with WHCR in all race and sex groups.

Adipose Tissue↗
PubMed1992

Severely disabled elderly persons with financially catastrophic health care expenses: sources and determinants.

This article describes the sources of financially catastrophic health care expenses among disabled elderly persons. Using a cost-to-income approach and data from the 1981-1982 Channeling Demonstration project, we examined the types of health care costs (hospital, physician and ancillary care, nursing home, and prescription medicine) that contributed to overall expenses. For the Channeling sample, out-of-pocket expenses for prescription medicines and for nursing home care were the principle source of catastrophic expenses.

Aged↗
PubMed1992

Cephalometric analysis of maxillofacial morphology in unoperated cleft palate patients.

This study was designed to investigate maxillofacial morphology in adolescents and adults with unrepaired cleft palate, with or without cleft lip. Twenty-two Chinese patients with unilateral cleft lip and palate (the UCLP group), and 21 Chinese with cleft palate (the CP group) were cephalometrically evaluated and classified into the five ranges established from the means and standard deviations for matched normal Chinese populations. Many subjects in both UCLP and CP groups showed an intrinsic maxillary retrusion and a steeper mandible. The others had nearly normal maxillofacial morphology. The tendency for maxillary retrusion and a steeper mandible became increasingly remarkable with age. In the long axis of upper incisors in subjects with permanent dentition, there were no UCLP subjects with labial inclination, whereas three CP subjects exhibited labial inclination.

Adolescent↗
PubMed1992

Correlates of obesity in young black and white women: the CARDIA Study.

OBJECTIVES: Although differences in obesity between Blacks and Whites are well documented in adult women, less information is available on potential correlates of these differences, especially in young adults. METHODS: The association between behavioral and demographic factors and body size was assessed in 2801 Black and White women aged 18 to 30 years. RESULTS: Black women had significantly higher age-adjusted mean body mass index and subscapular skinfold thickness than did White women. Obesity had different associations with age and education across racial groups. A positive relationship between age and obesity was seen in Black women but not in White women, whereas a negative association between education and body size was noted only in White women. Potential contributing factors to the increased prevalence of obesity in Black women include a more sedentary lifestyle, higher energy intake, earlier menarche, and earlier age at first childbirth. CONCLUSIONS: The difference in obesity across race could not be explained completely by these factors, since within virtually all strata, Black women had higher body mass indexes. Further investigation is needed to develop interventional strategies to prevent or reduce excess levels of obesity in Black women.

Adolescent↗
PubMed1992

International infant mortality rankings: a look behind the numbers.

The very unfavorable infant mortality ranking of the United States in international comparisons is often used to question the quality of health care there. Infant mortality rates, however, implicitly capture a complicated story, measuring much more than differences in health care across countries. This article examines reasons behind international infant mortality rate rankings, including variations in the measurement of vital events, and differences in risk factors across countries. Its goal is to offer a broader context for more informed debate on the meaning of international infant mortality statistics. These statistics offer opportunities to identify strategies for improving the U.S. health care system and learn from other countries that have been more successful.

Adolescent↗
PubMed1992

[Computerized tomography findings and clinical analysis of psychiatric disorder of praecox from head injury. Report of 52 cases].

This article reports and analyses 52 cases of psychiatric disorders of praecox from head injury. These patients included 39 males and 13 females. They were 13-80 years old. All of them examples by CT scan and found intracerebral hematomas or cerebral contusion. The shortest course of disease was 3 day, and the longest course was 53 day. 44 cases (84.7%) appear psychiatric disorders in first week. The most frequent psychiatric symptoms was disturbances of consciousness and dysmnesia. Disturbance of emotion, change of personality were also observed. Frequency of psychiatric disorders was same in brain traumatic of left or right lateralis. Course of disease and degree of psychiatric symptoms had nothing to do with size of hematoma and cerebral contusion, and relate to compression of ventricles of the brain. Encephalo-edema around the focus leading to regional compression of the brain was important factors for the disorder. The appearance of this disorder was early, course of disease was short, and prognosis was good.

Adolescent↗