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Biomedical subjects

J Waddington

Publications and source records attributed to J Waddington.

9 recordsLinked to original sources

Is reduced dermatoglyphic a-b ridge count a reliable marker of developmental impairment in schizophrenia?

BACKGROUND: Finger and hand prints are formed during the late first and second trimester of foetal development, after which they remain unchanged. Their expression may be influenced by both genetic and environmental factors. Some studies have suggested that a reduced total finger ridge count (TFRC) and, in particular, a reduce total a-b ridge count (TABRC), may be associated with schizophrenia. AIM: To study these two variables in a large, ethnically homogenous sample and to compare our findings with those of other recent studies. METHOD: Finger and hand prints of 150 people with DSM-III-R schizophrenia were compared with those of 92 healthy controls. RESULTS: Patients had a reduced mean TABRC (P = 0.03) compared with controls. There was a significant (P=0.02) linear trend for lower TABRC and increasing incidence of schizophrenia (ORlineartrend = 1.3; 95%CI1.1-1.7), implying a continuous increase in the risk for schizophrenia with reduction in TABRC. No significant difference between groups was observed for TFRC. CONCLUSION: These results provide further evidence that dermatoglyphic abnormalities exist in at least some patients with schizophrenia and that the a-b ridge count may be a marker of disruption, probably environmental, that occurs when the developing brain may also be particularly vulnerable to such insult. These findings support the concept that some cases of schizophrenia may be due to adverse intrauterine events.

Adult↗

Epidemic of blindness in kangaroos--evidence of a viral aetiology.

OBJECTIVE: To determine the cause of an epidemic of blindness in kangaroos. DESIGN AND PROCEDURES: Laboratory examinations were made of eyes and brains of a large number of kangaroos using serological, virological, histopathological, electron microscopical, immunohistochemical methods, and PCR with cDNA sequencing. In addition, potential insect viral vectors identified during the disease outbreak were examined for specific viral genomic sequences. SAMPLE POPULATION: For histopathological analysis, 55 apparently blind and 18 apparently normal wild kangaroos and wallabies were obtained from New South Wales, Victoria, South Australia, and Western Australia. A total of 437 wild kangaroos and wallabies (including 23 animals with apparent blindness) were examined serologically. RESULTS: Orbiviruses of the Wallal and Warrego serogroups were isolated from kangaroos affected with blindness in a major epidemic in south-eastern Australia in 1994 and 1995 and extending to Western Australia in 1995/96. Histopathological examinations showed severe degeneration and inflammation in the eyes, and mild inflammation in the brains. In affected retinas, Wallal virus antigen was detected by immunohistochemical analysis and orbiviruses were seen in electron microscopy. There was serological variation in the newly isolated Wallal virus from archival Wallal virus that had been isolated in northern Australia. There were also variations of up to 20% in genotype sequence from the reference archival virus. Polymerase chain reactions showed that Wallal virus was present during the epidemic in three species of midges, Culicoides austropalpalis, C dycei and C marksi. Wallal virus nucleic acid was also detected by PCR in a paraffin-embedded retina taken from a blind kangaroo in 1975. CONCLUSION: Wallal virus and perhaps also Warrego virus are the cause of the outbreak of blindness in kangaroos. Other viruses may also be involved, but the evidence in this paper indicates a variant of Wallal virus, an orbivirus transmitted by midges, has the strongest aetiological association, and immunohistochemical analysis implicates it as the most damaging factor in the affected eyes.

Animals↗

Vaccination of sheep with purified cysteine proteinases of Fasciola hepatica decreases worm fecundity.

There has been some evidence from several parasite systems that proteinases might have potential as protective antigens against parasitic infection. A cysteine proteinase complex identified in the regurgitant of adult F. hepatica was examined in this context. The thiol-cathepsin-related proteinases of M(r) 28,000 were purified and tested in vaccine trials of sheep infected with liver fluke. Ten animals were immunised with the purified proteinases and developed antibodies to the cysteine proteinases prior to challenge with F. hepatica metacercariae. Infection appeared to cause a boost in antibody response by Week 4 into infection, and antibody levels were generally sustained throughout infection. The cysteine proteinases are not novel antigens, since low-level antibody titres were also detected in nonimmunised controls by late infection. On completion of the trial, there was no difference in worm burden between the two groups. However, faecal egg counts and therefore worm fecundity were significantly decreased.

Animals↗

Glutathione S-transferase. Novel vaccine against Fasciola hepatica infection in sheep.

The potential of GST as a vaccine candidate against liver fluke infection in ruminants was studied by vaccinating sheep (n = 9) with GST purified from adult worms of Fasciola hepatica and challenging with 500 F. hepatica metacercariae. The immunization induced a high antibody response to GST in contrast to the poor or undetectable response to this Ag observed in naturally infected sheep. Throughout the trial, the progress of the fluke infection was monitored by measuring RBC hemoglobin levels, the extent of liver damage and the fecal egg output in the sheep. This analysis indicated that a subpopulation (n = 4) of the GST vaccinated animals exhibited no anemia, reduced liver damage and a lower mean fecal egg count relative to the infected control group suggesting a lower fluke burden in these animals. Worm burdens in the livers of the GST vaccine group (107 +/- 22) were 57% lower than in the infected control group (250 +/- 25). The subpopulation of the GST vaccine group demonstrated a 78% reduction in mean worm burdens relative to the control group. These results show that GST of adult F. hepatica is a novel Ag that can significantly protect sheep against liver fluke infection. The results suggest that the immune response to GST is directed to the juvenile worm reducing the number of worms that can establish in the liver of the vaccinated animals.

Animals↗

Diagnostic studies of the fetus, placenta and maternal blood from 265 bovine abortions.

During 1981, the fetus, placenta and maternal serum were received from each of 265 bovine abortions. These specimens were examined using histopathological, histochemical, bacteriological, mycological, endocrinological, immunological, serological and virological techniques. The cause of abortion was identified in 98 (37%) cases. Of these diagnosed abortions 27 (28%) were due to infection with fungi, 17 (17%) to Salmonella spp, 11 (11%) to Campylobacter fetus and 10 (10%) to Corynebacterium pyogenes infection. Of the remaining 33 (34%) diagnosed abortions 8 were due to Leptospira sp, 5 due to protozoan (probably Sarcocystis) encephalitis and 20 due to miscellaneous bacterial infections (including Brucella abortus) and fetal deformities. Bovine virus diarrhoea virus was isolated in 5 (2%) abortions, however the significance of the isolations was not known. Infectious bovine rhinotracheitis virus and chlamydia were not identified as causal agents in any abortion. In 18 (7%) abortions no definite etiologic agent was identified despite pathological findings suggestive of infection. Fetal heart blood serology and immunoglobulin values were not reliable indicators of infectious abortion. Of the remaining 149 (56%) abortions, 17% had high maternal serum cortisol levels and twin fetuses occurred in 9%.

Abortion, Septic↗

Transmissibility of Australian strains of Newcastle disease virus.

The transmission of Newcastle disease virus strains from infected to direct-, indirect-, and aerosol-contact groups of chickens was studied. Chickens 7, 21, and 63 days old were used in separate trials. Chicken age and virus strain were found to be important in spread of the virus. Strain V4 spread quickly to all contact groups and was classed as highly transmissible, whereas strain JA failed to infect all contact chickens of each age group, thus spreading less efficiently than strain V4. The viruses spread more readily among the 2 older groups. The significance of the transmissibility of Newcastle disease virus vaccine is briefly discussed.

Age Factors↗