Regulation of hemodynamics and oxygenation in developing intestine: insight into the pathogenesis of necrotizing enterocolitis

The pathogenesis of necrotizing enterocolitis remains unknown, but various factors have been postulated including, but not limited to, mesenteric ischemia, enteral alimentation, and infection. Since an understanding of circulatory physiology in developing intestine may provide insight into the role of mesenteric ischemia in the etiology of necrotizing enterocolitis, this review summarizes what is currently known about the regulation of blood flow and oxygenation in developing intestine and how it differs from that in adult intestine. The discussion is divided into intrinsic versus extrinsic factors. Phenomena which may be used to evaluate the capacity for intrinsic vasoregulation include pressure-flow autoregulation, reactive hyperemia, venous hypertension, arterial hypoxemia, and postprandial hyperemia. Extrinsic factors include neurologic and hormonal influences. Additionally, the susceptibility for tissue hypoxia as a function of age and the correlation with subsequent development of mucosal injury are discussed     

A molecular basis for hemoglobin-H disease in American blacks

We have applied gene counting and restriction endonuclease mapping techniques to the study of two American black families in which there were one or more cases of HbH disease. We found deletions of three of the four normal alpha-globin genes in individuals with HbH disease. In two of these individuals, the chromosome containing the single alpha gene could have originated by crossing over between mispaired alpha genes, resulting in a deletion of about 4.2 kilobases (kb).     

Oral health of Adelaide nursing home residents: longitudinal study

Objective: The Adelaide Dental Study of Nursing Homes aimed to quantify oral disease experience, incidence and increments in Adelaide nursing home residents. Methods: Questionnaires and dental inspections were completed at baseline and at 1‐year for residents from randomly selected Adelaide nursing homes. Results: The residents were very functionally dependent, cognitively impaired and behaviourally difficult older adults with complex oral problems and dental treatment needs. The prevalence of edentulism (total tooth loss) (63%) decreased and more residents were retaining natural teeth. Existing residents had a mean of 10.8 teeth present and new residents had a mean of 12.7 teeth present. Residents’ previous experiences of caries (decay) were high – existing residents had a mean of 1.2 decayed teeth and new residents had a mean of 0.8 decayed teeth. Residents’ caries increments (new decay) over the 1‐year period were high (coronal = 2.5 surfaces; root = 1.0 surfaces), especially in those who had lost weight and who could eat fewer food types. These levels of caries were many times greater than had been reported for community‐dwelling older adults. Large accumulations of plaque, calculus and debris (food) were evident on residents’ natural teeth and dentures, especially those with dementia. Up to 25% of residents owned dentures that were not worn. Residents with dementia gave their carers complex and challenging oral hygiene care problems. Existing and new residents had similar general health and oral health characteristics, with the exceptions that new residents had significantly more filled tooth surfaces, and fewer decayed retained roots. Conclusion: New residents were being admitted to the nursing homes with a compromised oral health status or developed severe oral diseases and conditions within several months of their admittance. Residents’ oral diseases, especially coronal and root caries, rapidly progressed during their stay in residential care.