Biomedical subjects

J J Pillow

Publications and source records attributed to J J Pillow.

4 recordsLinked to original sources

PubMed1997

High frequency ventilation.

The 1990s have seen a dramatic resurgence of interest in high frequency ventilation (HFV). The role of HFV in the rescue of infants failing conventional mechanical ventilation (CMV) is now relatively well established. However, the wider role of HFV in the routine management of respiratory failure in the newborn is more contentious. Recent trials in small numbers of infants suggest that HFV may be associated with significantly less chronic lung disease than CMV when used under optimal conditions (i.e. with a 'high-volume' strategy, from early in the disease and continued to the point of weaning). Further, clinical trials are now required to define the role of HFV more clearly.

Clinical Trials as Topic↗

PubMed1995

Vitamin D deficiency in infants and young children born to migrant parents.

OBJECTIVE: To determine the current modes of presentation for the development of nutritional vitamin D deficiency in Melbourne children. METHODOLOGY: A retrospective descriptive review was undertaken of the case records of children less than 5 years of age discharged from three Melbourne hospitals with a diagnosis of vitamin D deficiency or hypocalcaemia from January 1992 to January 1994. RESULTS: The study identified 13 infants and young children whose hospital admission was related to nutritional vitamin D deficiency. Significant morbidity and a broad spectrum of biochemical and clinical features were noted at presentation. All children had migrant parents and were either exclusively or predominantly breast fed. Ten infants (77%) were less than 1 year at presentation. Associated deficiencies of iron and B12 were present in five cases. Of the five mothers tested, serum 25-hydroxy vitamin D3 was low in four. CONCLUSIONS: Nutritional vitamin D deficiency is a continuing health problem in infants and young children born to migrant parents living in Melbourne. Paediatricians, obstetricians and general practitioners, particularly those managing women and infants from migrant communities, should be aware of this condition. Vitamin D supplementation to high-risk women during pregnancy and to their infants should be considered.

Breast Feeding↗

PubMed1987

Cell-layer-associated proteolytic cleavage of the telopeptides of type I collagen in fibroblast culture.

In human skin fibroblast cultures a fraction of the procollagen that was processed to collagen and remained in the cell layer was further proteolytically modified by removal of both N- and C-terminal telopeptides. The proteolytic activity was associated with the cell layer, since secreted collagens were found always to contain intact telopeptides. The inclusion of neutral polymers, which caused the accumulation of the collagen in the cell layer [Bateman, Cole, Pillow & Ramshaw (1986) J. Biol. Chem. 261, 4198-4203], made the telopeptide cleavage more apparent in those cells which expressed the proteolytic activity. The extent of this cleavage was variable from cell culture to cell culture and between experiments with the same fibroblast line. The proteolytic activity was pH-dependent; cleavage was greatest at a culture-medium pH of 7.5 and 8.0 and was completely inhibited at a culture-medium pH of 7.0 and 6.5. The activity was significantly inhibited by soybean trypsin inhibitor, an elastase-specific inhibitor (N-acetylalanylalanylprolylvalylchloromethane) and the thrombin inhibitor hirudin. This cell-associated proteolytic activity may play a role in collagen degradation by removing the telopeptides, which are the primary sites of collagen cross-linking, thus destabilizing the collagen matrix sufficiently to render it susceptible to further proteolytic breakdown.

Cells, Cultured↗

PubMed1986

Induction of procollagen processing in fibroblast cultures by neutral polymers.

In cultures of dermal fibroblasts, procollagen and the intermediates pC- and pN-collagen accumulated in the culture medium with little further processing to collagen. When polyethylene glycol (PEG) or other neutral polymers were added to fibroblast culture medium, no collagen or procollagen was found in the medium, but all the collagen was associated with the cell layer. The type I procollagen was fully processed to collagen with an initial transient accumulation of pN-collagen, and the processed collagen formed covalently cross-linked dimers. The presence of pepsin-sensitive COOH-terminal telopeptides and the accumulation of pN-collagen in PEG-treated cultures of dermatosparactic fibroblasts indicated that it was likely that processing occurred via the correct in vivo propeptidase activities. At the levels used in this study, PEG did not have any toxic effect during the incubation period on the fibroblasts in culture, since the amount of total protein synthesis was not altered by addition of PEG to cultures. However, the level of collagen production was reduced to about half, indicating that there was increased degradation or that the released collagen propeptides or the accumulation of processed collagen in association with the cells exerted a feedback regulation on collagen synthesis. Addition of neutral polymers to the culture medium provided a simple means of achieving complete and accurate processing of procollagen which more closely resembled the in vivo process.

Animals↗