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Biomedical subjects

C Block

Publications and source records attributed to C Block.

At least 73 records · Page 4Linked to original sources
PubMed1992

Effect of labor and delivery on neonatal polymorphonuclear leukocyte number and function.

The ability of the neonate to mount an adequate polymorphonuclear leukocyte (PMN) response, either quantitatively or functionally, is impaired. To assess whether neonatal PMN number and function are altered by labor and delivery, three groups of infants were studied: cesarean section without labor (10), cesarean section after labor (10), and vaginal delivery (11). PMN counts were higher in the groups undergoing labor (p less than 0.01) compared with the cesarean section without labor group. Similarly, the labor groups had evidence of complement activation (increased C3a desarg) compared with the cesarean section without labor group. No differences were noted between the groups in measures of PMN motility (chemokinesis or chemotaxis) or PMN degranulation (plasma lysozyme), suggesting that normal labor and delivery does not contribute to the general PMN dysfunction of the neonate.

Cesarean Section↗
PubMed1991

Reduction of transmission of shigellosis by control of houseflies (Musca domestica)

The effect of control of houseflies on the incidence of diarrhoea and shigellosis was evaluated in a prospective crossover intervention study at two military field bases several kilometers apart. In early summer, 1988, intensive fly control measures (mainly bait and trap strategy) were introduced on one base, while the other served as a control. After 11 weeks, as new cohorts arrived, the intervention was abruptly discontinued in the first base and instituted in the second for the next 11 weeks. The study was repeated the next summer. Overall, fly counts were 64% lower on the bases exposed to fly control measures (p = 0.024). Concomitantly, clinic visits dropped by 42% (p = 0.146) for diarrhoeal diseases and by 85% for shigellosis (p = 0.015), as did rates of seroconversion, by 76% (p = 0.024) for antibodies to Shigella and by 57% (p = 0.006) for antibodies to enterotoxigenic Escherichia coli. The findings indicate that houseflies, acting as mechanical vectors, transmit Shigella (and possibly enterotoxigenic E coli) diarrhoeal infections.

Adolescent↗
PubMed1991

Detection and treatment of brucellosis by screening a population at risk.

Brucellosis presents a difficult diagnostic challenge in view of its protean manifestations, multiple organ involvement and variable clinical course. The purpose of the present study was to determine whether active screening of a population at risk, identified through index cases, would enhance the detection rate of brucellosis and improve treatment. During a 1-month period all 98 individuals sharing risk factors with 4 diagnosed symptomatic cases of brucellosis in one Bedouin town in southern Israel were approached and 86 agreed to undergo screening. Symptomatic brucellosis was found in 8 (9%) of the screened population and an additional 5 (6%) asymptomatic individuals were found to be seropositive. These 13 were followed for 12 months. All symptomatic cases were treated and cured. Of the 5 asymptomatic seropositive individuals 2 showed a further elevation of Brucella antibody titers. One became symptomatic, was treated and was cured. This screening program provided 53% of all reported cases from the Bedouin town during the entire year of the study. Screening a population at risk increased the detection rate of brucellosis and improved the treatment.

Adolescent↗
PubMed1991

Prospective study of the association between serum antibodies to lipopolysaccharide O antigen and the attack rate of shigellosis.

A means for determining immune status against shigellosis would significantly improve the design and evaluation of interventional and other epidemiologic studies. Previous case-control studies have indicated the potential role of humoral antilipopolysaccharide antibodies. To test this proposition, 190 soldiers serving in a field unit were monitored prospectively for 2.5 months for shigellosis. Blood samples were taken at the beginning of the follow-up period and tested for serological evidence of prior exposure to Shigella sonnei and Shigella flexneri. The risk for acquiring S. sonnei shigellosis was 3.7 times higher for individuals lacking homologous antibodies (P less than 0.02). The risk for acquiring S. flexneri shigellosis was 2.4 times higher for individuals lacking antibodies, although a low attack rate for S. flexneri resulted in numbers too small to achieve statistical significance. While the importance of the serum antilipopolysaccharide antibodies in protection against the disease remains unclear, these findings demonstrate that they are strong markers of acquired immunity. Serological markers should be incorporated in epidemiologic studies of shigellosis and in the design and evaluation of future trials of potential anti-Shigella vaccines.

Antibodies, Bacterial↗
PubMed1990

Two different zinc sites in bovine 5-aminolevulinate dehydratase distinguished by extended X-ray absorption fine structure.

The zinc coordination in 5-aminolevulinate dehydratase was investigated by extended X-ray absorption fine structure (EXAFS) associated with the zinc K-edge. The enzyme binds 8 mol of zinc/mol of octameric protein, but only four zinc ions seem sufficient for full activity. We have undertaken a study on four forms of the enzyme: (a) the eight-zinc native enzyme; (b) the enzyme with only the four zinc sites necessary for full activation occupied; (c) the enzyme with the vacant sites of (b) occupied by four lead ions; (d) the product complex between (b) and porphobilinogen. We have shown that two structurally distinct types of zinc sites are available in the enzyme. The site necessary for activity has an average zinc environment best described by two/three histidines and one/zero oxygen from a group such as tyrosine or a solvent molecule at 2.06 +/- 0.02 A, one tyrosine or aspartate at 1.91 +/- 0.03 A, and one cysteine sulfur at 2.32 +/- 0.03 A with a total coordination of five ligands. The unoccupied site in (b), obtained by taking the difference spectrum between the spectra from samples (a) and (b), is dominated by a single contribution of four cysteinyl sulfur atoms at 2.28 +/- 0.02 A. Spectra from samples (c) and (d) show only small changes from that of (b), reflecting a slight rearrangement of the ligands around the zinc atom.

Animals↗
PubMed1990

An in-use evaluation of decontamination of polypropylene versus steel bedpans.

A prospective cross-over study in three different wards has demonstrated the lack of effect of two disinfectants compared with a detergent when added to the washing cycle of automatic bedpan washers that employ hot water centrally supplied at 60 degrees C. An unexpected and potentially important finding was that polypropylene pans were much more effectively cleaned and decontaminated than their stainless steel counterparts. The role, if any, of bedpans in the epidemiology of nosocomial infections remains a mystery. The continued absence of information clearly incriminating these ubiquitous devices in the transmission of potential pathogens, or of genes encoding antibacterial drug resistance, raises questions as to whether extensive efforts to achieve a high degree of decontamination of bedpans are necessary at all.

Cross Infection↗
PubMed1990

Nasal carriage of Staphylococcus aureus: correlation with hormonal status in women.

In view of recent observations on hormone-microorganism interactions, a study of Staphylococcus aureus nasal carriage in relation to sex-hormone status was undertaken. Prospectively in 479 women attending a colpocytologic clinic, hormonal status was assessed by determining the karyopyknotic index (KI) on smears stained by the Papanicolaou method. Rates of S. aureus nasal carriage were 29.3% in premenopausal women and 21.9% in postmenopausal women (P not significant). Carriage rates were significantly higher (P = .026, chi 2 7.32) for women with high KIs (40.7%) than for those with intermediate and low KIs (27.03% and 25.1%, respectively). S. aureus nasal carriage also correlated independently and significantly with previous antibiotic use and the presence of insulin-treated diabetes mellitus. This preliminary observation confirms an association between levels of sex hormones as reflected by the KI and S. aureus nasal carriage rates.

Adolescent↗
PubMed1990

Pefloxacin versus ceftazidime in therapy of soft tissue infections in compromised patients.

Soft tissue infections in compromised patients are frequently caused by Gram-negative organisms and particularly by Pseudomonas aeruginosa. These pathogens are effectively eradicated by pefloxacin as well as by ceftazidime. The effectiveness and safety of these two agents were compared in a prospective randomized study in 67 patients with soft tissue infections. Underlying conditions included malignant diseases, diabetes mellitus and chronic renal failure. The infections included: post operative infection, septic foot, soft tissue abscess and cellulitis. Thirty-three patients were treated with intravenous ceftazidime for a mean duration of ten days. More than half the 34 patients given pefloxacin were treated only orally for a mean period of 13 days. The clinical and bacteriological outcomes were similar in both groups. There was clinical cure or improvement in 26 pefloxacin cases and in 23 ceftazidime cases, failure in six pefloxacin cases and in seven ceftazidime and relapse in two pefloxacin and in three ceftazidime patients. The bacteriological responses were eradication in 23 pefloxacin cases and in 22 ceftazidime cases, persistence in five pefloxacin cases and in six ceftazidime cases, relapse in one pefloxacin case and in none of the ceftazidime group, reinfection in four pefloxacin cases and in three ceftazidime cases and there was one unassessed patient in the pefloxacin group and two in the ceftazidime group. Nausea and vomiting occurred in three patients and elevation of liver enzymes in another patient; all side effects were observed only in the pefloxacin treated patients. These results suggest that oral pefloxacin could offer an alternative to intravenous ceftazidime in half the compromised patients with tissue infections. However, adverse reactions due to pefloxacin administration should be watched for during such therapy.

Administration, Oral↗
PubMed1990

Rapid screening of urine for bacteria and cells by using a catalase reagent.

Five hundred urine samples were tested for cells and bacteria by using a commercial dipstick, a catalase screening device, standard culturing, and chamber counts. The sensitivities of the catalase test were 83% for all samples and 97.6% for specimens containing significant numbers of leukocytes and bacteria. The catalase screening test is simple to perform and should prove useful for the detection of urinary tract infections.

Bacteriuria↗
PubMed1990

Probing of active site residues of the zinc enzyme 5-aminolevulinate dehydratase by spin and fluorescence labels.

5-Aminolevulinate dehydratase from bovine liver requires Zn(II) for its activity and is inhibited by micromolecular concentrations of Pb(II). To elucidate the structure of the active site and its interactions between the active site and the metal binding site we labeled the active site for fluorescence studies and ESR spectroscopy. o-Phthalaldehyde reacted with active site lysyl and cysteinyl residues to form a fluorescent isoindole derivative. The fluorescence energy was independent of the deprivation of Zn(II) and of its substitution by the inhibitory Pb(II). For ESR-studies five iodoacetamide and four isothiocyanate pyrrolidine-N-oxyl derivatives with various spacer lengths were used to label the active site cysteinyl and lysyl residues, respectively. The ESR spectra of the modified enzyme preparations exhibited a significant immobilization of all labels, even with the longest spacers employed. Obviously the reactive cysteine is buried more than 12 A, and the active site lysine more than 11 A in a cleft of the enzyme structure. Zn(II) deprivation from the iodoacetamide spin-labeled enzyme caused a marked reversible increase in label mobility, whereas the Pb(II) substituted enzyme exhibited a smaller mobilization of the label. These results are interpreted by a model of the active site where the reactive cysteinyl and the lysyl side groups are close enough to be crosslinked by o-phthalaldehyde within a distance of 3 A. A structural role is assigned to Zn(II) in the enzyme, since Zn(II) deprivation does not alter the fluorescence of the isoindole derivative and increases the mobility of the cysteine-bound spin labels in the active site cleft.

Apoenzymes↗
PubMed1989

Immunoglobulin M, A, and G antibody response to lipopolysaccharide O antigen in symptomatic and asymptomatic Shigella infections.

The antilipopolysaccharide antibody response in sera obtained from subjects involved in 10 outbreaks of shigellosis occurring in Israeli military field units was determined by an enzyme-linked immunosorbent assay and a passive hemagglutination test. Both tests were found to be sensitive and specific for the diagnosis of shigellosis. A significant antibody response was detected in 73 to 82% of the symptomatic and 48 to 60% of the asymptomatic subjects during the Shigella sonnei and Shigella flexneri outbreaks. Fifty percent of the symptomatic and none of the asymptomatic subjects showed a significant antibody response in the Shigella boydii outbreaks. An examination of the kinetics of the antibody levels over a 10-week period after the onset of disease revealed that immunoglobulin A (IgA) levels were highest 2 weeks after infection and had declined to initial levels within 2.5 months. In contrast, IgG levels at the late convalescent stage were half those measured at early convalescence, still being about twice as high as the initial titers. Although the IgM levels showed a pattern similar to that of IgA, their elevation at the early convalescent stage was less pronounced. We conclude that the detection of an increase in the level of the IgA fraction appeared to be the best indicator for recent symptomatic, as well as symptomatic, infections due to Shigella organisms.

Adult↗
PubMed1989

Apparent effect of immune serum globulin prophylaxis in the military on viral hepatitis incidence in the civilian population in Israel.

Since 1969, extensive use of immune serum globulin in the Israel Defence Force for prophylaxis against hepatitis A virus (HAV) infection has produced a sharp decline in the incidence of the disease. However, it is not clear whether this policy has affected the susceptibility of Israeli adults to HAV infection. In this study, we examined the effect of the immunisation policy on the incidence of hepatitis A virus infection in the civilian population in the 15-44 year age group, which includes all those who have completed compulsory military service since vaccination was introduced. The incidence of viral hepatitis in the Jewish civilian population aged 15-44 increased by approximately 50% 3-4 years after the implementation of the immunisation policy. This rise was not seen in the non-Jewish population of the same age nor among Jews aged 45-64. These findings strongly suggest that the immunisation policy in the military prevents both clinical and sub-clinical disease, but has had the effect of producing more susceptible people at an older age in the civilian population.

Adolescent↗
PubMed1989

Saksenaea vasiformis infection in a burn wound.

Saksenaea vasiformis was isolated, after 18 days, from a burn wound caused by a petrol bomb. The fungus was locally invasive and was treated successfully by excision and systemic administration of amphotericin B. Identification of the isolate was accomplished by inducing sporulation on 1% agar containing grass clippings and on hay infusion agar.

Adult↗