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Biomedical subjects

K F Shortridge

Publications and source records attributed to K F Shortridge.

At least 127 records · Page 7Linked to original sources
PubMed1975

Absence of detectable hepatitis B antigen (HBAg) in the commercial oyster, Crassostrea gigas Thunberg, in Hong Kong.

The locally grown commercial oyster in Hong Kong, Crassostrea gigas Thunberg, is faecally polluted particularly in the summer months at a time when oyster consumption and the incidence of viral hepatitis similarly increase. Whole oysters and isolates of tissues including the digestive diverticula and mantle fluids, in unconcentrated or concentrated forms were examined by counterimmunoelectrophoresis for the presence of the hepatitis-B antigen (HBAg); No antigen was detected in samples examined on a monthly basis over a one year period nor those examined hourly for one day in mid-summer. HBAg may not have been detected since the pollution of the oyster beds was considered to be predominantly of animal rather than human origin.

Animals↗
PubMed1975

Arbovirus infections in reptiles: studies on the presence of Japanese encephalitis virus antibody in the plasma of the turtle, Trionyx sinensis.

This study was undertaken to examine further the natural infection of poikilothermic animals e.g. turtles, to Japanese encephalitis (JE) virus. Plasma samples from 75 soft-shelled fresh water turtles (Trionyx sinensis Wiegman) from China were examined in virus neutralization (VN) and hemagglutination inhibition (HAI) tests for the presence of specific antibody. The total incidence of antibody detected by either test to a titer of 10 or greater was 89% while 77% and 60% were positive by VN and HAI tests, respectively. Forty-one per cent were jointly positive by both tests. Mean HAI and VN titers were similar and showed no obvious differences between spring/summer and autumn/winter seasons. The HAI reactivity was associated with a 7S component for both seasons. The significance of this inhibition in the serology of poikilothermic hosts and the possible behaviour of T. sinensis in the natural history of JE virus is briefly considered.

Animals↗
PubMed1975

Studies on the inhibitory activities of human serum lipoproteins for Japanese encephalitis virus.

Human serum lipoproteins were purified by ultracentrifuging and their concentrations adjusted as required to be within the normal male/female serum range for all assays. The activities in inhibition of hemagglutination (HAI) for Japanese encephalitis virus were--low density lipoprotein (LDL) greater than very low density lipoprotein (VLDL) greater than high density lipoprotein (HDL). Heating (56 degrees C/30 minutes) caused the LDL titer to fall and freeze-thawing (20 degrees C/room temperature) the VLDL titer to rise slightly, possibly as a result of alteration in lipoprotein structure. The additon of lipoprotein depleted serum appeared to dampen these effects and there was no nett change in titer when it was added to a lipoprotein mixture. Similarly, unfractionated normal serum showed no significant change in titer after these treatments. The lipoproteins lacked significant virus neutralizing (VN) activity and this remained so in spite of fluctuations in HAI titer after heating and freeze-thawing.

Antiviral Agents↗
PubMed1975

Ethnic aspects of cord serum alpha 2-macroglobulin levels in Chinese, Caucasians and Ghurkas in Hong Kong.

Serum alpha 2-macroglobulin (alpha 2-M) levels were measured in cord sera of Chinese, Caucasian and Ghurka babies in Hong Kong by the antibody-agar radial immunodiffusion technique. The values for male babies of the three ethnic groups were 293 +/- 59, 323 +/- 79 and 303 +/- 72 mg./100 ml., respectively; those for female babies were 287 +/- 74, 315 +/- 74 and 317 +/- 7) mg./100 ml., respectively. Although a general similarity of cord serum alpha 2-M levels was evident at birth, it was noted that ethnic differences in the level of this serum protein only become apparent later in life. The value obtained for Caucasian cord serum alpha 2-M in Hong Kong was significantly lower than a published value for Caucasians elsewhere.

Adult↗
PubMed1974

Trypsinized human group O erythrocytes as an alternative hemagglutinating agent for Japanese encephalitis virus.

Trypsinized human group O erythrocytes were found to be a suitable alternative to gander cells in hemagglutination (HA) and hemagglutination inhibition (HAI) tests for Japanese encephalitis (JE) virus. In the HAI test, no cross-reactions against JE virus were observed with immune sera containing antibody to taxonomically related or unrelated viruses, with mouse brain antigen, or with nonantibody serum inhibitors; specific antibody rise could be detected in an immunized rabbit. Gander and trypsinized human group O cells gave comparable titers in the HAI test, but the latter were preferable since (i) they required less challenging HA antigen, being more sensitive to agglutination by JE virus, and (ii) all human and some animal sera investigated were devoid of natural agglutinins for these cells, thereby eliminating or reducing the need for prior adsorption with packed cells.

ABO Blood-Group System↗