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Biomedical subjects

D Scheifele

Publications and source records attributed to D Scheifele.

49 records · Page 3Linked to original sources
PubMed1987

Rapid postmortem gut autolysis in infant rats: a potential problem for investigators.

Experiments were designed to determine the rate and nature of postmortem autolysis in the gut of neonatal rats, as necessary baseline information for developing a model of human neonatal necrotizing enterocolitis. We studied 60 animals, including 33 Wistar rats, 18 Sprague-Dawley rats and nine CD-1 mice. The variables examined included age of the animals (2 or 14 days) and length of delay and holding temperature (20 degrees C or 37 degrees C) after sacrifice. At necropsy, bowel was rapidly removed and fixed for histopathological examination. In all instances, bowel removed immediately after sacrifice was normal whereas after delays as short as 30 minutes it was abnormal (P less than 0.001), becoming markedly so after 60 minutes. The prominent features were detachment and lysis of mucosal epithelial cells. The rate of autolysis was not altered in 14 day old animals or in carcasses held at 20 degrees C or 37 degrees C. Investigators of bowel injury syndromes in young rats should be aware that histopathological studies will be valid only if specimens held at room temperature are fixed within 15 minutes of death.

Animals↗
PubMed1984

Evaluation of skin antisepsis prior to blood culture in neonates.

In our Intensive Care Nursery, coagulase-negative staphylococcus is the most frequent blood culture isolate. As skin antisepsis is critical in preventing blood culture contamination, we examined the efficacy of the chlorhexidine tincture (CH) used in our nursery for this purpose. Staphylococcus epidermidis colonized the forearms of 88% of infants tested, in a mean density of 10(4) organisms/cm2. Following a 60-second application of CH (0.5% in 70% ethanol), bacterial growth from forearm skin remained abundant in 15/38 infants (39.4%). Cleansing with 70% isopropyl alcohol, followed by CH as above, left abundant residual growth in only 1/37 infants (2.7%) (P less than 0.001). All 136 S. epidermidis tested were susceptible to CH (MIC less than 5 micrograms/ml) and 14 of 15 exposed to CH 0.02% were rapidly killed (greater than or equal to 98% fall in viable counts within 90 sec). We conclude that two-phase antisepsis using isopropanol followed by CH is a more effective preparation for blood culture in neonates than is CH alone.

1-Propanol↗
PubMed1978

Increasing incidence of ampicillin resistance in Hemophilus influenzae.

The incidence of ampicillin resistance in Hemophilus influenzae and its medical significance have not been extensively determined. During 1975-1977, we tested for ampicillin resistance 489 consecutive middle-ear isolates of HI obtained from children in Huntsville, Alabama, and 719 consecutive laboratory isolates of HI from Children's Hospital, Boston. The annual incidence of Amp resistance rose progressively in each survey, from initial values of 1.4 to 5.3% in 1975, to 14 to 16% in 1977 (P less than 0.05), a mean annual rate of increase approximately twofold. Resistance was equally prevalent among type b and non-b isolates and among nasally carried and disease-associated isolates (from blood, CSF, middle ears). Patients harboring AmpR isolates were much more likely to have had recent exposure to beta-lactam antibiotics (P less than 0.01).

Ampicillin↗
PubMed1976

Otitis media caused by non-typable, ampicillin-resistant strains of Haemophilus influenzae.

Strains of Haemophilus influenzae, which did not belong to any of the known capsular serotypes and which were resistant in vitro to ampicillin, have been isolated from middle ear exudates of two children with otitis media. These children failed to improve with ampicillin therapy, and the resistant organisms persisted at the site of infection. Patients infected with such ampicillin-resistant organisms require therapy with antimicrobial agents which are not susceptible to degradation by penicillinase.

Ampicillin↗
PubMed1976

Incidence of ampicillin-resistant Hemophilus influenzae in otitis media.

Ampicillin resistance in Hemophilus influenzae type b causing serious infections is appreciated, but little is known about ampicillin resistance in nonencapsulated strains causing otitis media. The ampicillin sensitivity of 984 middle-ear isolates of H. influenzae from children in Huntsville, Ala. obtained from 1970-1976, was examined: Nine AmpR isolates were found: one in 1973, two in 1974, three in 1975, and three in the first five months of 1976. Seven strains were nonencapsulated; two were type b. All nine produced beta-lactomase. The incidence of ampicillin resistance in strains causing otitis media increased from 0.6% in 1973 to 2.4% in 1976. AmpR H. influenzae infection should be suspected in situations where ampicillin therapy of otitis media is unsuccessful.

Alabama↗