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Biomedical subjects

A L Zhang

Publications and source records attributed to A L Zhang.

25 records · Page 2Linked to original sources
PubMed1994

A medium term follow-up study of patients with hypertrophic pyloric stenosis.

A structured questionnaire was sent to the parents of 120 children from a cohort 192, who had undergone a pyloromyotomy for pyloric stenosis at Westmead Hospital during the years 1984-91. Information was gained from 85 children in 82 families regarding gastrointestinal complaints and family history of pyloric stenosis. There were few gastrointestinal problems, no reports of recurrent abdominal pain, but two reports of clinically significant vomiting (2.3%) and one of infantile colic. Of the 85 individuals studied, 21 (24.7%) had a positive family history of pyloric stenosis, a higher frequency than previously reported.

Child↗
PubMed1993

Infantile hypertrophic pyloric stenosis: a clinical review from a general hospital.

A review of 212 cases of infantile hypertrophic pyloric stenosis (IHPS) in a general hospital during an 8.5 year period documents clinical features and suggests refinement of treatment. Features such as sex, age at onset and presentation were similar to other studies. There was a preponderance of infants born in the summer. Premature infants represented 10% of the series, and the most premature (< 33 weeks gestation) presented later after birth (40 vs 25 days). Diagnosis was clinical in 65% of cases, but 4% presented before physical examination and diagnostic tests were positive. At the time of admission only 15% had significant abnormalities of serum electrolytes (chloride < 85 mmol/L). The periumbilical incision resulted in a hidden scar. Duodenal perforation (3.3%) and wound dehiscence (1.4%) are related to technical factors and can be avoided. The timing of commencement of postoperative feeds did not influence the rate of vomiting. The average length of stay was 3.5 days. These results are discussed with suggestions about how to minimize diagnostic tests and length of hospital stay.

Female↗
PubMed1992

Aganglionosis in rodents.

The etiology of aganglionosis of the bowel remains controversial. Initial embryological studies in chicks, mice, and humans suggested the defect was in the migratory capacity of the vagal neural crest cells. This traditional theory has recently been challenged by the demonstration of a defect in the local microenvironment and the suggestion that neural crest cells migrate normally until they reach the terminal defective segment of bowel which then excludes them. To contribute to this debate we studied three rodent animal models using histological, "in vivo" (kidney capsule), and "in vitro" (tissue culture) techniques. The results suggest that there is no discernible difference between mutant and normal embryos in the early migration from the vagal neural crest to the stomach. Migration through the small bowel is normal in mutant mice, but is slowed in the rat. In both strains of mice the migration of enteric precursors into the mutant colon is slowed over an extended period of time, such that a difference between normal and mutants is evidenced well before the final aganglionic region is reached. Aganglionosis is the result either of a defect in vagal neural crest migration or in the microenvironment over an extended area of the bowel and not just in the terminal aganglionic colon. There are changes in the appearance of mutant enteric neurons in tissue culture and some alterations in the gut mesenchyme; it remains to be determined which is the primary event.

Animals↗
PubMed1990

[Dorsal root potential evoked by stimulation of periaqueductal gray and its efferent pathway analysis in rats].

When periaqueductal gray (PAG) was stimulated with concentric electrodes, a steady negative potential called PAG-DRP was recorded from L5 dorsal root. PAG-DRP with properties of spatial and temporal summation propagates decrementally along the dorsal root and is inhibited by picrotoxin. Lesions of NRM had no effect on the PAG-DRP evoked by stimulation of dorsal PAG, but showed obvious reduction up to about 40% on the PAG-DRP evoked by stimulation of ventral PAG. It is suggested that the descending inhibition of PAG includes some presynaptic inhibition and that the ventral PAG-DRP is relayed partly via NRM while the dorsal PAG-DRP is not associated with NRM.

Animals↗
PubMed1989

An epidemiological study of behaviour problems in school children in urban areas of Beijing.

A total of 2432 primary school children, aged 7-14 yrs. in urban areas of Beijing, were evaluated with the Children's Behaviour Questionnaire developed by Rutter. The frequency of behaviour problems in primary school was 8.3%-7.4% antisocial behaviour and 0.62% neurotic behaviour. Behaviour problems were higher in boys than girls: antisocial behaviour was dominant in boys, while neurotic behaviour was common in girls. The frequency of behaviour problems varied significantly with the different social environments in which the children were brought up, but were not different between one-child families and those with more children.

Adolescent↗