Search PubMed⌕ Search

Biomedical subjects

A Ho

Publications and source records attributed to A Ho.

At least 181 records · Page 10Linked to original sources
PubMed1986

Isolation and characterization of high-buoyant-density proteoglycans from semilunar menisci.

Proteoglycans were extracted from adult canine menisci in high yield and were purified, and the major species were characterized biochemically. Most proteoglycans in menisci were isolated in the high-buoyant-density fraction. By agarose-acrylamide composite gel electrophoresis, two proteoglycans were seen in this fraction. Although they were smaller than those from porcine laryngeal hyaline cartilage and had shorter chondroitin sulphate and keratan sulphate chains and a lower carbohydrate-to-protein ratio, they were functionally similar to those in hyaline cartilage in their specific interaction with hyaluronate.

Animals↗
PubMed1985

Toward an analogue of alcoholism in mice: criteria for recognition of pharmacologically motivated drinking.

Two criteria of alcoholic drinking behavior--inelasticity of demand and dissociation of intake from normal eating and drinking--are illustrated by study of alcohol-preferring C57BL/6J mice. Although these mice drink enough to become intoxicated for brief periods each night, they do not meet the more rigorous criteria for pharmacologically motivated drinking. Their intake of alcohol was dramatically decreased when they were offered diets augmented with sugar or Crisco, and the temporal pattern of drinking was correlated with the intake of food. Thus, their motivation for drinking alcohol is related to nutrition and is not drug-seeking comparable to that of human alcoholics. Since the tests are simple and decisive, it might be useful to apply them to all putative models of alcoholism.

Alcoholism↗
PubMed1983

An improved technique for monitoring the drinking behavior of mice.

A set of calibrated lickometers provides continuous, quantitative monitoring of fluid consumption. It has been used in our laboratory at four levels of temporal resolution: 24 hr, 1 hr, 6 min, and for counting of individual licks. Convenient features are mounting of the licking tube-bottle assembly on the cage top (which permits the use of disposable plastic cages with litter) and automated collection of data with microcomputers.

Alcohol Drinking↗
PubMed1983

Electrotonic parameters of rat dentate granule cells measured using short current pulses and HRP staining.

The passive electrotonic parameters of nerve cells in the dentate gyrus of the rat were studied in vitro. Intracellular recordings from 30 granule cells and 3 pyramidal basket cells followed by intracellular injection of horseradish peroxidase (HRP), allowed calculations of input resistance (RN), membrane time constant (tau m), electrotonic length (L), ratio of dendritic to somatic conductance (rho), membrane specific capacitance and resistance (Rm, Cm), and specific axoplasmic resistance (Ri). The analysis of the voltage decays from long saturating (100 ms) and short (0.5 ms) current pulses showed that the short-pulse method gave better resolution for the measurement of the time constants and avoided some of the time-dependent nonlinearities but required larger currents than the long pulse. Morphological analysis of 49 branching points taken from the dendritic trees of granule cells showed that the branching power, n, is equal to 1.56 +/- 0.186 and was fairly constant throughout the tree. Given the fact that all dendrites have approximately the same length and number of branch points, the granule cell dendritic tree can be meaningfully collapsed into an equivalent cable. Moreover, electrophysiological data suggested that the cable had a "sealed" end or at least a high-impedance termination. Based on an equivalent cable model with a sealed end and a lumped soma impedance, a method was implemented to analyze the multiexponential decays from hyperpolarizing current pulses and to solve the equations of the model. This was done successfully in only 40% of the cells and yielded the following mean values for L = 1.13 and rho = 7.58. From the measurements of the soma surface area (S) and the equivalent cable diameter (D), the average specific membrane parameters were calculated: Rm = 2,726 alpha x cm2, Cm = 5.24 microF/cm2, Ri = 101 alpha x cm. The input resistance and time constant of the granule cells as measured from the short-pulse technique averaged to RN 58.57 M alpha and tau m = 16.21 ms. The failure of the model to fit 60% of the cells was interpreted to be due to the presence of a somatic shunt resulting from electrode injury, tonic synaptic activity, a lower somatic membrane specific resistance, or electronic coupling.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1982

[Occurrence of HLA-antigens in patients with hypertrophic cardiomyopathy].

The etiology of hypertrophic cardiomyopathy with (HOCM) and without obstruction (HCM) is poorly understood. Controversial data have been published concerning the association of HLA-B-12-antigen with HOCM and HCM respectively. Further, HLA-D-antigen occurrence has been determined in few patients with HOCM or HCM. In 29 patients with HOCM, 38 patients with HCM, and matched healthy persons we determined the occurrence of HLA-A, B, C and DRW-antigen using the test of microcytotoxicity in lymphocytes. HLA-antigens occurred with similar frequency in patients with HOCM and HCM and in control subjects. 25% of the patients and 23% of the control subjects had HLA-B-12. Further, no difference was detected in the frequency of occurrence of HLA-antigens in patients with HOCM and in patients with HCM. The data support the view that HLA tissue typing is of no diagnostic value in identifying patients with HOCM or HCM.

Adult↗
PubMed1981

The effect of chronic poisoning with carbon tetrachloride on voluntary consumption of ethanol by mice.

Mice were chronically poisoned with carbon tetrachloride injected twice weekly, intraperitoneally, in doses of 0.05-0.80 mg/g over 10 to 16 weeks. The poisoned animals, as compared to vehicle-injected controls, showed marginally significant increases in voluntary consumption of ethanol in a three-bottle choice (water, 10% and 20% ethanol continuously available), but not to a degree than could be considered alcoholic. The average daily intakes of ethanol remained within the range of variation for normal animals of this strain; there was no consistent shift in preference from 10% to 20% ethanol, and the distribution of drinking times within the 24-hour cycle remained normal. The relevance of these findings to the clinical problem of alcoholism is that the appetite for alcohol, a potential hepatotoxin, persists despite serious damage to the liver.

Alcohol Drinking↗
PubMedDate not supplied

Early experience and the consumption of alcohol by adult C57BL/6J mice.

Two types of early experience were examined for their effect on voluntary alcohol consumption by adult C57BL/6J mice: the experiences associated with belonging to a particular litter, and the experience of early postweaning choice between water and a 10% alcohol solution. Males from identified litters were individually caged from arrival at three weeks of age and given a choice between 10% alcohol and water when eight weeks old. Another group without notation of litter was given alcohol-water choice upon arrival at three weeks of age. Alcohol intake was examined by three measures: daily licks of 10% alcohol, alcohol selection (percent alcohol drinking), and volume of alcohol drunk daily. Belonging to a particular litter did affect body weight and growth, but had no effect on adult consumption of alcohol. Postweaning exposure to alcohol choice, however, produced a small but significant and prolonged increase in alcohol consumption by adults. Furthermore, a developmental trend was found in mice offered alcohol choice at an early age: alcohol preference developed as postweaning growth slowed.

Aging↗