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Biomedical subjects

N K Sheth

Publications and source records attributed to N K Sheth.

33 records · Page 2Linked to original sources
PubMed1983

In vitro quantitative adherence of bacteria to intravascular catheters.

Adapting standard techniques, a simple in vitro system was devised to compare quantitative bacterial adherence to iv catheters of different compositions. Upon brief immersion of catheters in suspensions of Staphylococcus aureus, coagulase-negative staphylococci, and Escherichia coli, organisms adhered to catheter surfaces. After overnight growth in broth, organisms remained adherent and formed colonies, as shown by light and scanning electron microscopy. In addition, quantitative adherence using a blood agar roll technique, expressed as bacteria per square centimeter of catheter surface area per 10(6) colonies per milliliter inoculum, was calculated. Adherence was greater on polyvinylchloride (PVC) catheters (geometric mean 342) than on Teflon catheters (geometric mean 49.6) for coagulase-negative staphylococci (P less than 0.005). Also, the number of coagulase-negative staphylococci adherent to PVC catheters was significantly greater than for E. coli (geometric mean 70.6) at analogous inocula (P less than 0.02). Differences in bacterial adherence to the surface of iv devices may be important in the pathogenesis of catheter-associated infections. This in vitro method could prove useful in testing bacterial adherence properties of newly developed catheter materials, and allow development of catheters less prone to be associated with bacterial adherence and catheter-related infections.

Adhesiveness↗
PubMed1983

Antibiotic prophylaxis in patients undergoing prostatectomy.

The value of antibiotic prophylaxis in patients undergoing prostatectomy was assessed in a randomized study using three schedules of gentamicin administration. All three gentamicin schedules were effective in lowering the incidence of postoperative bacteriuria, with a single dose of gentamicin two hours preoperatively being the most effective. Antibiotic prophylaxis did not significantly affect the clinical course.

Bacteria↗
PubMed1983

Multidose vials versus single-dose vials: a study in sterility and cost-effectiveness.

A total of 197 multidose injectable vials were collected from 10 different nursing stations and evaluated for sterility. Experimental contamination studies were undertaken, and the cost-effectiveness of multidose vials was compared with that of single-dose vials. Our results showed that bacterial contamination of multidose injectable vials was not a significant hazard; in addition, contrary to common belief, the use of multidose vials was not always successful as a cost-containment measure.

Bacillus↗
PubMed1983

Colonization of bacteria on polyvinyl chloride and Teflon intravascular catheters in hospitalized patients.

During an 8-month period all intravascular catheters were removed by sterile technique upon completion of use and submitted to the hospital microbiology laboratory. All catheters were routinely cultured by the semiquantitative culture technique, with greater than or equal to 15 colonies being defined as a positive result. Of the 687 Teflon catheters cultured, 6.9% were positive by culture, compared with 24.6% of 77 polyvinyl chloride catheters (P less than 0.001). Also, colonization of coagulase-negative staphylococci on polyvinyl chloride was more than on Teflon. These data suggest that polyvinyl chloride catheters are colonized more frequently with organisms than are Teflon catheters; additionally, there is an increased affinity of coagulase-negative staphylococci for polyvinyl chloride as compared with Teflon, substantiating our previous observations with an in vitro system. We conclude that the type of catheter material may be important in determining the incidence of catheter-related infections and in selective colonization by coagulase-negative staphylococci.

Bacterial Infections↗
PubMed1982

Bacteremia due to Cedecea neteri sp. nov.

Three of four blood cultures from a patient with possible endocarditis were positive for a new species of Enterobacteriaceae which is named Cedecea neteri. This is the first reported case of bacteremia caused by a strain of Cedecea.

Enterobacteriaceae↗
PubMed1982

Pulmonary and disseminated Mycobacterium simiae infection in humans.

Three patients with Mycobacterium simiae infection were seen during a 5-yr period. One patient with chronic infiltrative pulmonary disease had the diagnosis established by open lung biopsy. Two patients with normal chest roentgenograms had disseminated infection, one having had elective surgery for a nonfunctioning kidney. Caseating granulomata were discovered in kidney tissue sections. Both M. kansasii and M. simiae were subsequently recovered from bone marrow and urine cultures. The other patient had vertebral osteomyelitis, and M. simiae was isolated from tissue obtained by needle biopsy. To our knowledge, disseminated M. simiae infection has not been previously described.

Aged↗
PubMed1981

Meningococcal pneumonia. A source of nosocomial infection.

Pneumonia apparently resulting from aspiration became clinically apparent in an elderly man two days after admission to a private room on a general medical ward. Pneumonia developed in a patient in an adjacent room three days later. Both patients had group B Neisseria meningitidis isolated from a percutaneous transtracheal aspirate. A prevalence survey failed to identify meningococcal carriers among other ward patients. The index patient required frequent nasotracheal suctioning during the first two hospital days prior to penicillin G potassium therapy. The second patient was simultaneously receiving continuous oxygen therapy administered by nasal cannula. Events suggested that the organism may have been transmitted by direct contact, probably on the hands of hospital personnel.

Aged↗
PubMed1981

Experimental aspergillosis in rabbits.

Controls, as well as cortisone-treated rabbits, were challenged with Aspergillus fumigatus spores intratracheally. Animals were sacrificed 3, 7, 14 and 28 days after inoculation and their organs cultured and studied histologically. Lesions were produced in both groups, although the cortisone-treated group showed greater pathology and the lesions persisted for a longer period of time than the control groups. Histologically, the pulmonary lesions showed granulomatous pulmonary aspergillosis and suppurative necrotizing pneumonic infiltrates.

Animals↗
PubMed1980

The role of Aspergillus fumigatus antigens in blood coagulation and platelet function.

The effects of Aspergillus fumigatus antigens on platelet function of rabbits was studied. A. fumigatus antigens produced spontaneous and irreversible aggregation of platelets. Aspirin, indomethacin or lidocaine did not block the antigen-induced aggregation. However, no aggregations occurred when complement depleted plasma was used. No differences were noted between the strains used. Our findings show that soluble Aspergillus antigens can cause platelet aggregation in vitro, possibly via a complement dependent pathway. The likely implications of these findings in clinical situations are discussed.

Animals↗
PubMed1978

Pulmonary candidiasis. A clinical and pathological correlation.

Thirty patients with systemic Candida infection underwent autopsy during a 13-year prospective study. Eleven patients had tissue-verified pulmonary candidiasis. Nine of these patients had hematogenous dissemination, as evidenced by multiple organ invasion; two had aspiration pneumonia with lung involvement only. Aspiration Candida pneumonia is rare. Pulmonary candidiasis usually arises from a focus of infection implanted during hematogenous dissemination. An infected indwelling venous catheter was the source of candidemia in six of these patients. Organisms in the lumen of pulmonary vessels caused a necrotizing vasculitis and appeared to invade the parenchyma from these areas.

Adult↗
PubMed1976

Immunotyping and pyocin typing of Pseudomonas aeruginosa from clinical specimens.

Two hundred sixty-seven strains of Pseudomonas aeruginosa isolated from clinical specimens were immunotyped using seven anti-Pseudomonas rabbit sera, and pyocin typed using eight indicator strains. Of the 230 consecutive isolates tested, 83% were immunotypable and 90% were pyocin typable. When both typing methods were used concurrently, 261 strains were typed, giving a 98% overall typability. An attempt was made to correlate sensitivity to carbenicillin and gentamicin with various immunotypes. Using growth from sensitivity plates directly for immunotyping as an added advantage for early surveillance and treatment is discussed.

Bacteriocins↗
PubMed1975

Evaluation of tyrosine medium for the identification of Enterobacteriaceae.

Use of the tyrosine medium in the identification of members of the family Enterobacteriaceae form the basis of this paper. Six hundred and twenty-three strains were tested for their property of tyrosine degradation. Three hundred and seventy-two strains were positive in 24 h and an additional eight strains were positive in 48 to 72 h. These positive strains consisted of all 344 strains of the Proteus-Providencia group, all 25 strains of Citrobacter diversus, and three strains of atypical C. freundii. Our findings suggest that tyrosine degradation is a useful property for separating out the Proteus-Providencia group and in specific identification of C. diversus.

Citrobacter↗
PubMed1971

The possible significance of IgA in abnormal cerebrospinal fluid.

In a study of 21 patients with disease of the central nervous system IgA, which is normally absent, could be detected in the cerebrospinal fluid in the presence of meningitis of bacterial or fungal origin: the concentration of IgA in the cerebrospinal fluid could not, however, be correlated with serum levels. A reaction of non-identity has been demonstrated between serum and cerebrospinal fluid IgA using the diffusion technique on cellulose acetate. These data seem to suggest that cerebrospinal fluid IgA is produced independently of serum IgA and can be detected in measurable amounts where microorganisms are the cause of inflammatory disease of the central nervous system.

Cellulose↗
PubMed1968

Inherited thrombocytopenia with thrombasthenia.

A family with congenital thrombocytopenia is described through four generations where the mode of inheritance appears to be an autosomal dominant. Spontaneous bruising of varying severity, menorrhagia, and profuse bleeding at operation necessitating transfusion were predominant in the history. Platelet function tests were performed on the various patients. Platelet aggregation by adenosine diphosphate (ADP) was found to be defective, though liberation of platelet factor III and platelet thromboplastic function were found to be normal when corrected for deficient numbers.

Adult↗