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Biomedical subjects

B J Ruck

Publications and source records attributed to B J Ruck.

8 recordsLinked to original sources
PubMed1978

Pattern of shedding of two noncultivable viruses in stools of newborn babies.

Noncultivable viruses have been associated with diarrhea affecting newborn babies in obstetric hospital nurseries. Persisting infection in a special care nursery in Melbourne, Australia, permitted a study of the pattern of excretion of these viruses. Ten babies admitted to the nursery within 2 hr of birth were randomly selected for prospective study. Feces were collected daily for 14 days and were examined by electron microscopy. All ten babies excreted detectable amounts of duovirus (rotavirus, HRVL agent, IGV) for at least 1 day. Age at onset of excretion varied from 2 to 13 days. Eight of the ten babies developed diarrhea. Excretion of duovirus preceded the onset of diarrhea by 12--72 hr and persisted for at least 3 days. Seven of the ten babies also excreted detectable amounts of 28-nm virus-like particle for 3--8 days. The identity of this particle is unknown. Morphologically it resembles Norwalk agent and "astrovirus." Excretion of this 28-nm particle coincided with symptoms of diarrhea in four babies, all of whom were also excreting duovirus. It is concluded that most newborn babies admitted to a nursery where duovirus infection is endemic will excrete this virus at least once during the first 2 weeks of life. Excretion of virus particles will either precede development of diarrhea or be asymptomatic. Selective isolation of babies with diarrhea is thus unlikely to control spread of duovirus infection within a hospital nursery.

Australia↗
PubMed1976

Is lactase the receptor and uncoating enzyme for infantile enteritis (rota) viruses?

Rotaviruses are now regarded as important causes of diarrhoea in man, cattle, pigs, mice, and possibly other animals. Characteristically, disease occurs in newborn and young animals, and infection seems limited to the differentiated gut epithelial cells. The major surface polypeptide of the calf scours rotavirus is glycosylated, and highly purified beta-galactosidase (lactase) interacts with the virus in vitro causing removal of the outer shell of the capsid (uncoating). It is suggested that lactase present in the brush border of the intestinal epithelial cell performs a similar function in vivo by acting as a combined receptor and uncoating enzyme for the rotavirus. This hypothesis is consistent with the observations that rotaviruses seem to infect only gut epithelial cells, and that infant animals, whose lactase concentrations are generally higher than those of adult animals, seem more susceptible to rotavirus infections. Implications of the hypothesis include possible new approaches to laboratory cultivation of rotaviruses, which should be more successful in cells selected for surface lactase activity, and the suggestion that the epidemiology of human rotavirus infections may be influenced by the fact that different ethnic groups have different lactase levels (and hence lactose intolerance) in adulthood.

Acute Disease↗
PubMed1976

The aetiology of diarrhoea in newborn infants.

Diarrhoea is a common problem in newborn infants in hospital nurseries. In the past, sporadic diarrhoea was often attributed to dietary indiscretion by the mother, and epidemic diarrhoea was though to be caused by an unknown infectious agent. Techniques with which to locate non-cultivable viruses and untypable enteropathogenic strains of Escherichia coli allow reevaluation of the aetiology of diarrhoea in newborn infants. Preliminary results from Melbourne, Australia, suggest that most diarrhoea in newborn infants is induced by a specific infectious agent. During 1975 the agent most often identified from sporadic and epidemic diarrhoea in hospital nurseries was a reovirus-like particle ("duovirus"). Enterotoxin-producing strains of E. coli were rarely isolated. Future attempts to protect newborn infants from developing diarrhoea must be based on an accurate understanding of the aetiology of this disease.

Australia↗
PubMed1976

An epidemic of diarrhoea in human neonates involving a reovirus-like agent and 'enteropathogenic' serotypes of Escherichia coli.

During December 1974, an epidemic of diarrhoea occurred in the Royal Children's Hospital, Melbourne, in a ward caring for neonates with acute or chronic medical and surgical problems. Electron microscopy of diarrhoeal faeces revealed a reovirus-like particle ('duovirus' or 'rotavirus') known to cause acute enteritis in older children. This virus is considered to have been primarily involved in the aetiology of the epidemic. In addition, three 'enteropathogenic' serotypes of Escherichia coli were isolated from babies during the epidemic, but none produced enterotoxin when tested in ligated ileal loops of rabbits or in monolayers of Y1 adrenal cells. Further epidemics of neonatal diarrhoea must be studied using culture and electron microscopy of faeces to determine the relative importance of this virus and of E. coli in the aetiology of diarrhoea in this age-group.

Diarrhea, Infantile↗
PubMed1975

Immunofluorescence in duodenal mucosa of children with acute enteritis due to a new virus.

Electron microscopy od duodenal mucosa from children with acute non-bacterial enteritis has shown virus particles in epithelial cells. Indirect immunofluorescent techniques applied to the same tissue showed virus antigen localized in the cytoplasm of epithelial cells of the villi. Specific IgM antibody was present in sera from infected patients as early as two days after the onset of symptoms. Virus particles from different patients appeared to share a common antigen. The evidence presented supports our belief that this new virus was the cause of acute enteritis in the children studied.

Antigens, Viral↗