Search PubMed⌕ Search

Biomedical subjects

D L Fritz

Publications and source records attributed to D L Fritz.

23 records · Page 2Linked to original sources
PubMed1989

Options for providing health care for the uninsured: opportunities for managed care.

The problem of providing health care for the uninsured has regained national attention. A variety of approaches are being tried across the country including State High Risk Pools and other insurance pools, increased individual policy options, and expansion of Medicaid and Medical Assistance eligibility. One of the key design elements in these approaches often is the use of managed care. A review of important design features and risk factors is presented. Findings from a welfare-to-work demonstration project are described including enrollees who lose Medicaid but do not have employer based health benefits.

Aid to Families with Dependent Children↗
PubMed1989

Determinants of tracheobronchial histologic alterations during conventional mechanical ventilation.

It was hypothesized that diverse mechanisms may influence upper airway injury during mechanical ventilation. To assess the roles of several factors in the propagation of such injury, the tracheobronchial histologic changes in 53 newborn piglets were compared following conventional positive pressure ventilation. Eight animals were assigned to each of four positive pressure ventilation groups at "low" settings (an FiO2 of 0.25, a frequency of 10 breaths per minute, a peak inspiratory pressure of 20 cm H2O, a positive end-expiratory pressure of 4 cm H2O, a flow rate of 10 L/min, and an inspiratory time to expiratory time ratio of 1:2): (1) positive pressure ventilation with no hypotension or hypoxemia; (2) positive pressure ventilation with hypotension; (3) positive pressure ventilation with hypoxemia; and (4) positive pressure ventilation with both hypotension and hypoxemia. In addition, eight piglets were assigned to each of two positive pressure ventilation groups at "high" settings (greater frequency [40 breaths per minute], higher peak inspiratory pressure [40 cm H2O], and greater flow rate [17 L/min]): (1) positive pressure ventilation with no hypotension or hypoxemia; and (2) positive pressure ventilation with both hypotension and hypoxemia. The changes were mild and similar among the first three positive pressure groups at low settings. However, the injury scores of the combined hypotension and hypoxemia group (group 4) were greater than those of the former three positive pressure ventilation groups (P less than .004). The piglets receiving positive pressure ventilation at high settings with no hypotension or hypoxemia (group 5) had no more injury than those in the first three groups receiving positive pressure ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Characterization of the plasmid from Escherichia coli RDEC-1 that mediates expression of adhesin AF/R1 and evidence that AF/R1 pili promote but are not essential for enteropathogenic disease.

RDEC-1, an Escherichia coli strain that adheres to rabbit mucosa and causes an attaching, effacing lesion, expresses the pilus adhesin AF/R1 which determines in vitro attachment to rabbit intestinal brush borders. In order to determine the role of AF/R1 pili in the pathogenesis of enteropathogenic diarrhea in rabbits, we localized the genes for AF/R1 expression, constructed an AF/R1- strain, and compared the virulence of the AF/R1+ and AF/R1- strains with particular attention to the development of attaching, effacing lesions. We introduced Tn5 into the 86-megadalton (MDa) conjugative plasmid known to mediate expression of AF/R1 pili and transferred the derivative plasmids into laboratory strain HB101. Transconjugant M5 was found to contain the 86-MDa plasmid from RDEC-1 and to express AF/R1 pili. Pilus expression on M5 was confirmed by reaction with antiserum raised against purified AF/R1 pili and allowed the bacteria to adhere to the rabbit ileum in an in vitro assay. Three Tn5 insertions in the 86-MDa plasmid were obtained which resulted in loss of AF/R1 expression. Part of the plasmid was mapped, including a region necessary for AF/R1 pilus expression. AF/R1- mutant strain M34 was constructed, and its pathogenesis was investigated. M34 produced disease in rabbits but was less virulent than the parent. The characteristic effacing lesions of RDEC-1 and enteropathogenic E. coli developed in the intestine of rabbits infected with either M34 or RDEC-1, although with M34 they were much less frequent and did not involve the small bowel. We conclude that AF/R1 pilus expression is not essential for the attaching, effacing lesion but serves as an accessory virulence factor which promotes an initial interaction of RDEC-1 with normal epithelial cells.

Adhesins, Escherichia coli↗
PubMedDate not supplied

Ultrastructure of Besnoitia besnoiti tissue cysts and bradyzoites.

Besnoitia besnoiti is an economically important tissue cyst-forming apicomplexan of cattle in Africa and Israel. Tissue cysts and bradyzoites of B. besnoiti from the skin of a naturally infected bull were studied by transmission electron microscopy. Tissue cysts enclosed host cell and bradyzoites. Bradyzoites were 6-7.5 x 1.9-2.3 microm in size and contained organelles found in coccidian merozoites including numerous micronemes, rhoptries, amylopectin granules, and a posteriorly located nucleus. Enigmatic bodies, characteristically found in Besnoitia sp. bradyzoites, were not observed. Therefore, enigmatic bodies should be removed as a generic character of the bradyzoites of Besnoitia species.

Animals↗