PubMed Health⌕ Search

Biomedical subjects

D Hazlett

Publications and source records attributed to D Hazlett.

9 recordsLinked to original sources
PubMed1999

Etiology of serious infections in young Gambian infants.

BACKGROUND: Despite improvements in infant mortality rates in many developing countries including The Gambia, neonatal mortality remains high and many neonatal deaths are caused by infection. The study described in this paper was conducted to determine the bacterial and viral etiology of serious infections in Gambian infants younger than 91 days old. METHODS: At a first level health facility 497 infants with symptoms that could indicate serious infection were enrolled, of whom 239 with 1 or more signs of serious infection and 55 with no signs were investigated, yielding 17 cases with positive bacterial cultures of blood and/or cerebrospinal fluid. At a nearby pediatric referral hospital 198 infants were seen and 182 were investigated, yielding 35 positive bacterial cultures. RESULTS: There were 15 culture positive cases of meningitis caused by Streptococcus pneumoniae (7), Streptococcus pyogenes (2), Enterobacter cloacae (2), Escherichia coli (1), Haemophilus influenzae type b (1), Streptococcus agalactiae (1) and Salmonella spp. (1). Six of these children died. Thirty-three infants without meningitis had positive blood cultures for Staphylococcus aureus (17), S. pneumoniae (3), Salmonella spp. (5), E. coli (3), other enterobacteria (4) and S. agalactiae (1), of whom 14 died. Nasopharyngeal aspirates from 438 children were investigated for common respiratory viruses. Respiratory syncytial virus was found in 51, influenza A in 46, influenza B in 22, parainfluenza in 26 and adenovirus in 16. Respiratory syncytial virus and influenza A isolates were found most frequently toward the end of the wet season. Nasopharyngeal carriage of S. pneumoniae and H. influenzae was studied in 320 infants recruited during the first year. Of these 184 (58%) were positive for S. pneumoniae and 141 (44%) were positive for H. influenzae, 18 of which were type b. Infants with a bacterial isolate from blood or cerebrospinal fluid were more likely than the rest to die, whereas those with a viral isolate were less likely to die. CONCLUSIONS: The most important causes of serious infections in young Gambian infants are Staphylococcus aureus, S. pneumoniae and Salmonella spp.

Bacteria↗
PubMed1994

The etiology of pneumonia in malnourished and well-nourished Gambian children.

During a 2-year period 159 malnourished children ages 3 months to 5 years with radiologic evidence of pneumonia were investigated to determine the cause of their pneumonia. In addition 119 malnourished children without pneumonia, 119 well-nourished children with pneumonia and 52 well-nourished children without pneumonia were studied as controls. Percutaneous lung aspiration was performed on 35 malnourished and 59 well-nourished children with pneumonia. Bacteria were isolated from the blood, lung or pleural fluid of 28 (18%) malnourished children with pneumonia, 42 (35%) well-nourished children with pneumonia and from the blood of 5 (4%) malnourished children without pneumonia. Streptococcus pneumoniae and Haemophilus influenzae, which were the two organisms isolated most frequently in both groups of children with pneumonia, were found in 17 (11%) malnourished and 39 (33%) well-nourished children with pneumonia. Mycobacterium tuberculosis was detected in 5 malnourished children with pneumonia. A potentially pathogenic virus was identified in 35% of malnourished children with pneumonia and 40% of well-nourished children with pneumonia, and from 25% of children without pneumonia. The viruses identified most frequently were adenovirus and respiratory syncytial virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoviridae↗
PubMed1992

Genetic characterization of Sabin types 1 and 3 poliovaccine virus following serial passage in the human intestinal tract.

Poliovirus isolates types 1 and 3 were obtained from five and seven successive passages respectively, in infants who had been fed monovalent OPV in two separate clinical trials conducted in 1960. The purpose of these trials was to answer the question how much the vaccine virus would revert to its original neurovirulent phenotype following multiplication in the intestinal tract. Human passages were performed either by contact exposure or by feeding the excreted virus while the infants were maintained in isolation. Several virus isolates were obtained at each passage level. Infants participating in both studies showed no symptoms of disease. Antigenic studies (McBride, van Wezel) and protein analysis (PAGE) of the isolates, reported earlier from this laboratory, had shown that the isolates remained vaccine-like, although isolates from the later passages revealed some differences. Monkey neurovirulence test results showed that for both types 1 and 3 viruses the loss of attenuation of the vaccine strain upon passage was gradual, although the loss was faster for type 3. Examination of the oligonucleotide maps demonstrated that the oligonucleotide configuration of the isolates remained the same as for the vaccine strain but there was an increase of individual spot differences with increasing passage. The nucleotide sequence analysis of selected regions of the virus genomes revealed that there was no change from a G to A in nucleotide 480 of type 1 isolates; however, nucleotide 476 changed from a U to an A in type 1 passages 3, 4 and 5. Conversely, for type 3 the change of nucleotide 472 from a U to a C changed at the early first passage (4 days following administration of OPV), and remained a C in the six following passages; type 3 nucleotide 2034 did not change in the first passage from a U to a C, but it became a C in all further passages tested. The nucleotide changes mentioned for both virus types remained stable in successive passages. However, there was another nucleotide change for type 3 from a U to a C at position 1973 only for passages 5 and 6 which reverted to a U for passages 7L and 7LL. Study of selected human passage virus strains could further contribute to the identification of the critical nucleotides that are responsible for the attenuation of these two polio types of vaccine viruses.

Base Sequence↗
PubMed1986

Clinical evaluation of rosoxacin for the treatment of chancroid.

One hundred seven men with Haemophilus ducreyi-positive chancroid were assigned to receive 300 mg of rosoxacin as a single dose or 150 mg twice daily for 3 days. Ulcers and buboes were followed clinically and bacteriologically for 1 month. Of 40 evaluable males on the 3-day regimen, 38 (95%) were cured, while only 14 of 23 (61%) males on the single-dose regimen were cured; this regimen was discontinued. There was one ulcer relapse at day 21 in both groups; the one relapse in the single-dose group had a persistent culture-positive bubo. Eight of nine (89%) buboes followed to the endpoint on the 3-day rosoxacin regimen were cured, versus three of six (50%) on the single-dose regimen. Adverse effects were mainly related to the central nervous system but were minor and did not require intervention. None of the treatment failures was due to organisms resistant to rosoxacin, and failure of the single-dose regimen presumably was related to duration of tissue levels rather than to drug resistance. Administration of 150 mg of rosoxacin twice daily for 3 days is an effective regimen for the therapy of chancroid and is a reasonable alternative to other short-course regimens.

4-Quinolones↗
PubMed1986

Effects of malnutrition and chronic reserpine treatment on pancreatic exocrine function.

The chronically reserpine-treated rat, an experimental model for cystic fibrosis, exhibits generalized exocrinopathy, impaired pancreatic secretion, and decreased pancreatic amylase. Although chronic reserpine treatment induces malnutrition by decreasing food consumption and growth, the effects of this malnutrition per se on the exocrine pancreas have not been considered. In this study, the effects of chronic reserpine treatment and malnutrition on the exocrine pancreas were determined using pair-fed controls. Male, Sprague-Dawley rats were treated daily subcutaneously for 5 to 7 days with: no injection (control), 1.0 ml/kg vehicle or sham (control-sham, pair fed-sham), or 0.5 mg/kg reserpine (chronically reserpine-treated). Both chronic reserpine-treatment and pair-feeding significantly decreased food consumption (40%), body weight (51 and 59%), total pancreatic amylase (49 and 56%) and specific amylase activity (62 and 61%), pancreatic protein (65 and 75%), and pancreatic weights (62 and 65%) compared to controls. These decreases, however, were comparable between the chronically reserpine-treated and pair fed-sham rats. In contrast, the secretory response to the biologically active cholecystokinin analog cholecystokinin octapeptide was significantly attenuated in isolated pancreatic acini prepared from reserpine-treated rats compared to that from either control or pair-fed sham rats. Malnutrition decreased pancreatic amylase activity and protein comparably to reserpine treatment, but only partially attenuated the secretory response to cholecystokinin octapeptide. Based on the results of this study, pair-fed controls should be used to distinguish between the effects of reserpine alone and the induced malnutrition on pancreatic exocrine function in studies of this experimental model of cystic fibrosis.

Amylases↗
PubMed1984

Aetiology of pneumonia in children in Goroka Hospital, Papua New Guinea.

To determine the aetiology of pneumonia in 83 children admitted to Goroka Hospital, Papua New Guinea, lung aspirates and blood were cultured for bacteria. Haemophilus infuenzae, Streptococcus pneumoniae, or both, were isolated from 43 (52%) of the children, other bacteria from 8 (10%), and no bacteria from 32 (39%). Of the 32 strains of H influenzae tested, 18 (56%) were non-serotypable, 8 (25%) were serotypes other than type b, and only 6 (19%) were type b. Viruses were isolated from lung or nasopharyngeal aspirates from 18 (29%) of the 62 children for whom viral cultures were done. It seems that, although viruses may initiate infection, death from pneumonia in children in developing countries is often due to H influenzae, S pneumoniae, or both. Antibiotic therapy would prevent many of these deaths. There is an urgent need for vaccines, effective in children less than 6 months old, that protect against all strains of H influenzae, and S pneumoniae.

Biopsy, Needle↗
PubMed1976

Relationship between Intralipid-induced hyperlipemia and pulmonary function.

One unit (500 ml) of 10% Intralipid (an intravenous soy bean oil-egg yolk lecithin preparation) was infused into 20 normal subjects over 4 hr. Serum triglyceride concentration and plasma optic density (at 700 nm) increased to maximal levels of 339 +/- 102 mg/100 ml and 1.14 +/- 0.41, respectively, at the completion of the infusion, and returned to basal levels in most subjects within 4 hr. Pulmonary membrane diffusion was decreased in six subjects at rest and with exercise at 25 and 50% maximum oxygen uptake. Only one subject showed a minor change in PO2 and none showed clinical signs of ischemia. The changes in pulmonary diffusion reverted to basal levels when serum lipids were cleared. Heparin (60 IU/kg) prevented the marked increase in serum lipids and, as a consequence, the changes in pulmonary function. Changes in pulmonary function from Intralipid-induced lipemia are similar to those known to result from diet-induced lipemia. The findings suggest that in the presence of normal vasculature and pulmonary function, Intralipid-induced lipemia should cause no clinical consequences. However, patients with preexisting pulmonary or vascular disease may be at greater risk after Intralipid-induced lipemia.

Adult↗