Biomedical subjects

K Heel

Publications and source records attributed to K Heel.

9 recordsLinked to original sources

PubMed2000

An outbreak of multi-resistant Shigella sonnei in a long-stay geriatric nursing centre.

An outbreak of Shigella sonnei infection in a long-stay nursing centre was detected during routine surveillance of notifications in July 1999. Subsequent investigations identified 13 cases of multi-resistant S. sonnei infection affecting nine staff, three community members associated with the centre and one resident of the centre. Each isolate of S. sonnei was genetically indistinguishable. The outbreak investigation identified contact with residents with vomiting and diarrhoea as a significant risk factor for infection amongst staff providing nursing care. This association, and the duration of the outbreak over several months, suggests that transmission was most likely person-to-person. This outbreak demonstrates the importance of infection control policies and hygiene measures in long-stay nursing facilities.

Aged↗

PubMed1999

Hepatitis A outbreaks among illicit drug users and their contacts in Queensland, 1997.

OBJECTIVE: To describe five outbreaks of hepatitis A virus (HAV) infection associated with illicit drug use during a statewide outbreak of HAV infection in Queensland. DESIGN: Risk factor prevalence survey. PATIENTS AND SETTING: All 875 cases of HAV infection notified to Public Health Units in Queensland in the 12 months to 30 November 1997. MAIN OUTCOME MEASURE: Type and prevalence of illicit drug use. RESULTS: Risk factor assessment was completed for 804 cases (91.9%). We identified five outbreaks of HAV infection linked to illicit drug use. These outbreaks accounted for 24.6% (215/875) of all notified cases and 39% (190/482) of notified cases in the 15-34 years age group. The main type of illicit drug use in four of the five outbreaks was injecting drug use (74%; 118/160), while in the other outbreak it was sharing of smoking implements for marijuana (38%; 21/55). CONCLUSION: Illicit drug use may be an under-recognised risk factor for HAV infection, particularly in young people. Faecal-oral transmission through poor personal hygiene, including sharing of implements for smoking marijuana, is the most probable route of transmission in these drug-linked outbreaks. The role of contaminated drug and needle-sharing remains to be clarified.

Adolescent↗

PubMed1998

The role of enterocytes in gut dysfunction.

Stem cells in the intestinal epithelium give rise to enterocytes, goblet cells, enteroendocrine cells, and Paneth cells. Each of these cell lines plays a role in cytoprotection of the intestinal mucosa. In particular, it has been demonstrated that mature enterocytes can act as antigen presenting cells. Parenteral and enteral nutrition are used to nourish critically ill patients. However, these regimens are unfortunately associated with gut atrophy. Glutamine, the preferred intestinal nutrient, reverses this gut atrophy and plays a key role in maintaining the barrier function of the gut. Specific nutrients (putrescine, spermidine, spermine) have been used to modulate intestinal adaption. In addition, ornithine has been shown to act as a regulator of intestinal adaption. In this review, we discuss the relationship between the biology of enterocytes and failure of the gut barrier.

Animals↗

PubMed1998

Influence of ischaemia-reperfusion injury on CD44 expression in rat small intestine.

BACKGROUND: CD44 is an adhesion molecule expressed by neutrophils and lymphocytes which is involved in cell-cell and cell-matrix binding. In this study, the effect of ischaemia-reperfusion injury on CD44 messenger RNA (mRNA) and cell surface immunohistochemical expression of CD44 in the rat small intestine was evaluated. METHODS: Wistar rats (n=16) were randomized to either serve as controls (sham surgery) or to be subjected to a standardized ischaemia-reperfusion injury (suprarenal aorta occluded for 1 h followed by 1 h of reperfusion). Standardized segments of jejunum were harvested after ischaemia-reperfusion injury (ischaemic and reperfused samples) to measure the mucosal protein and DNA content, mRNA expression of CD44 and the immunohistochemical expression of CD44. RESULTS: Reperfusion significantly damaged the jejunal mucosa, e.g. mucosal protein content was lower after reperfusion compared with that in the control group (z=-2.31, P=0.02) and the ischaemic samples (z=-2.52, P=001). The expression of cell surface CD44 protein was also significantly decreased after ischaemic injury (z=-1.99, P=0.04); this coincided with a decrease in the amount of cytoplasmic CD44 mRNA within isolated enterocytes (z=-2.31, P=0.02). CONCLUSION: Ischaemia-reperfusion injury decreases the expression of CD44 within the jejunal mucosa. This may contribute to the failure of the gut barrier after such injury.

Animals↗

PubMed1998

The influence of ischemia/reperfusion injury on the jejunum.

Ischemia/reperfusion injury (IRI) after free tissue transfer of the small intestine results in transmural tissue damage. This study examined the effects of IRI on the jejunum. Wistar rats served either as controls (N=10) or underwent clamping of the infrarenal aorta for 1 hour followed by 1 hour of reperfusion (N=10). Both ischemia and reperfusion reduced the protein and deoxyribonucleic acid content of the jejunal mucosa (p < 0.05). Myeloperoxidase activity in the jejunal mucosa remained relatively low. The expression of leukocyte function-associated antigen 1 and intercellular adhesion molecule 1 (ICAM-1) on the surface of mucosal cells was not altered significantly by the ischemic insult, but was reduced after the period of reperfusion (p < 0.05). This coincided with an increase in messenger ribonucleic acid (mRNA) for ICAM-1 within isolated mucosal cells (p < 0.05). The specific activity of glutaminase in isolated jejunal mucosal cells was diminished after ischemia and reperfusion (p < 0.05), and this was not associated with an appreciable change in glutaminase mRNA expression. These results have identified some molecular mechanisms underlying IRI of the small intestine that are possible candidates for therapeutic intervention.

Animals↗

PubMed1996

Glutamine.

Glutamine is the most abundant free amino acid in the circulation. It is a primary fuel for rapidly dividing cells and plays a key role in the transport of nitrogen between organs. Although glutamine is absent from conventional regimens aimed at nutritional support, glutamine deficiency can occur during periods of metabolic stress; this has led to the reclassification of glutamine as a conditionally essential amino acid. Experiments with various animal models have demonstrated that the provision of glutamine can result in better nitrogen homoeostasis, with conservation of skeletal muscle. There is also considerable evidence that glutamine can enhance the barrier function of the gut. This review concludes by discussing the clinical evidence that supports the inclusion of stable forms of glutamine in solutions of nutrients.

Enteral Nutrition↗

PubMedDate not supplied

Loss of heterozygosity studies in squamous cell carcinomas of the head and neck.

BACKGROUND: Loss of heterozygosity (LOH) studies have been pivotal in identifying tumor suppressor genes involved in the pathogenesis of a number of cancers. In squamous cell carcinomas of the head and neck region (SCCHN), LOH studies using the Southern blot technique are scarce. METHODS: SCCHNs were obtained immediately after surgical resection from 78 patients. Histologic confirmation was made by frozen section and tumors with less than 50% malignant cells were excluded. DNA was digested with restriction enzymes, and after Southern blotting the membranes were hybridized with radio-labeled probes. Chromosome arms analyzed included 1p, 3p, 4p, Sq, 8p, lOp, 11p, 11q, 13q, 17p, 17q, 18q, 21q, and 22q. RESULTS: The average rate LOH was 25% per chromosome arm. Significantly higher rates of LOH were observed for chromosome arms 5q (56%) and 17p (45%). Other investigators have reported high rates of LOH for the H- ras-1 locus, and chromosome arms 11p, 11q, and 13q. However, these results were not confirmed in this study. For patients with stage 1 or 2 tumors, the overall LOH rate was 13%, and for patients with stage 3 or 4 disease the rate was 23%. This difference was statistically significant (p < 0.025). CONCLUSIONS: tumors progress to higher stages, they appear to accumulate an increasing number of genetic abnormalities. Chromosome arms 5q and 17p contain tumor suppressor genes which are likely to be involved in the pathogenesis of SCCHN:

Adult↗

PubMedDate not supplied

The role of glutaminase in the small intestine.

Glutaminase is the enzyme which hydrolyses glutamine, the main respiratory fuel of the intestine, to yield glutamate and ammonia. Glutaminase has a central role in intestinal metabolism: the products of the reaction catalyzed by glutaminase can be transaminated, catabolized to yield energy or used for the biosynthesis of pyrimidine nucleotides. Experimental treatments which deprive the intestine of glutamine induce intestinal atrophy. In this review, attention is paid to the role of glutaminase in intestinal metabolism. Background information on the structure, kinetics and distribution of glutaminase precede a discussion of the metabolism of glutamine within the intestine. In closing, we review the factors known to regulate glutaminase activity and emphasise that the regulation of glutaminase within the intestine is poorly understood.

Caco-2 Cells↗

PubMedDate not supplied

Potential exposure to Australian bat lyssavirus, Queensland, 1996-1999.

Two human deaths caused by Australian bat lyssavirus (ABL) infection have been reported since 1996. Information was obtained from 205 persons (mostly adults from south Brisbane and the South Coast of Queensland), who reported potential ABL exposure to the Brisbane Southside Public Health Unit from November 1,1996, to January 31, 1999. Volunteer animal handlers accounted for 39% of potential exposures, their family members for 12%, professional animal handlers for 14%, community members who intentionally handled bats for 31%, and community members with contacts initiated by bats for 4%. The prevalence of Lyssavirus detected by fluorescent antibody test in 366 sick, injured, or orphaned bats from the area was 6%. Sequelae of exposure, including the requirement for expensive postexposure prophylaxis, may be reduced by educating bat handlers and the public of the risks involved in handling Australian bats.

Adolescent↗