Search PubMed⌕ Search

Biomedical subjects

V J Gill

Publications and source records attributed to V J Gill.

At least 55 records · Page 3Linked to original sources
PubMed1991

Clinical and microbiological observations on CDC group DF-3, a gram-negative coccobacillus.

Sequential stool cultures submitted for routine culture were screened for the presence of CDC group DF-3. Of 690 specimens, 11 (1.6%) yielded moderate to heavy growth of DF-3. Information on the 11 patients from whom these specimens were obtained showed that 4 had a history of prolonged diarrheal disease that resolved after specific therapy to eradicate DF-3, while for the other 7 patients no clear role could be established. Microbiological characterization of the stool isolates and 10 CDC strains of DF-3 suggested the presence of two subtypes within the group. Antibiotic susceptibility studies showed DF-3 to be relatively resistant to a wide variety of antibiotics.

Adolescent↗
PubMed1991

Effect of aerosolized pentamidine prophylaxis on the diagnosis of Pneumocystis carinii pneumonia by induced sputum examination in patients infected with the human immunodeficiency virus.

This study assessed the effect of aerosolized pentamidine prophylaxis on the clinical presentation and diagnostic sensitivity of induced sputum examination for Pneumocystis carinii pneumonia. Between January 1, 1988 and October 27, 1990, 348 induced sputum examinations were performed as the initial diagnostic procedure for P. carinii pneumonia in patients infected with the human immunodeficiency virus (HIV). Medical records were reviewed for all induced sputum examinations, and the study group consisted of patients who either had not received prophylactic therapy (n = 193) or had received aerosolized pentamidine prophylaxis (n = 126). A total of 29 induced sputum examinations in patients receiving either other prophylactic regimens or ongoing therapy for previously documented P. carinii pneumonia were excluded from the study group. A total of 72 consecutive episodes of P. carinii pneumonia were subsequently documented by induced sputum examination (n = 54), bronchoalveolar lavage (n = 16), thoracocentesis (n = 1), or autopsy (n = 1). A total of 44 episodes occurred in patients who had not received antipneumocystis prophylaxis, and 28 episodes occurred in patients who had received aerosolized pentamidine. Of patients capable of producing a sputum specimen for analysis, induced sputum examination had a significantly lower diagnostic yield of 64.3% in patients who had received aerosolized pentamidine prophylaxis compared with 92.3% in patients who did not receive prophylaxis (p less than 0.02, Fisher's exact test). When the data were analyzed on an intention to treat basis, although there was a trend suggesting a lower overall yield in the aerosolized pentamidine patients, the difference was not statistically significant (64.3 versus 81.8%, p = 0.17, Fisher's exact test).(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1989

Multicategory interpretive reporting of susceptibility testing with selected antimicrobial concentrations. Ten years of laboratory and clinical experience.

For the last 10 years, the NIH Microbiology Laboratory has been using a broth microdilution method to perform antibiotic susceptibility tests. Instead of using a continuous twofold dilution series as we had done for the previous 10 years, in 1978 we introduced a susceptibility panel that utilized a minimal number of selected (discontinuous) antimicrobic concentrations. The concentrations selected were those thought to be the most clinically relevant, based on known pharmacologic properties of each antimicrobic agent, as well as known MIC population distributions that we had acquired on 50,000 organisms in the preceding years. In addition to using selected concentrations, we also added interpretive codes to aid the physician in selecting the best antimicrobic agent to use. We had previously only reported quantitative MIC results without qualitative interpretations. The present interpretive criteria inform the physician not only if the organism is susceptible or resistant but also if intramuscular or intravenous doses are needed, if the organism is susceptible to an antimicrobic agent but only for lower urinary tract infections, if the organism is resistant to penicillin by virtue of penicillinase production, and in the case of streptococci, if streptomycin or gentamicin can be expected to show synergy when combined with a penicillin. The use of clinically relevant selected concentrations combined with clear interpretive criteria has worked well in our hospital setting. Physicians are able to understand and utilize the information effectively and have found almost no need for exact MICs using a twofold dilution series.

Anti-Infective Agents↗
PubMed1988

Nonspecific interstitial pneumonitis without evidence of Pneumocystis carinii in asymptomatic patients infected with human immunodeficiency virus (HIV).

STUDY OBJECTIVE: To assess how often Pneumocystis carinii organisms, P. carinii pneumonia, or other pulmonary pathologic processes were present in persons infected with human immunodeficiency virus (HIV) without pulmonary symptoms or previous history of P. carinii, and with a normal chest roentgenogram. DESIGN: Serial, prospective assessment of eligible HIV-seropositive patients over 21 months. PATIENTS: Twenty-four HIV-seropositive patients with either a nonpulmonary manifestation of the acquired immunodeficiency syndrome (AIDS) (n = 12) or an absolute CD4 lymphocyte count of 0.200 X 10(9) cells/L or less (n = 12), no pulmonary symptoms, a normal chest roentgenogram, no history of P. carinii pneumonia, and no history of treatment with antipneumocystis prophylaxis. INTERVENTIONS: Pulmonary assessment with arterial blood gases, pulmonary function tests, gallium-67 citrate scans, and bronchoscopy with bronchoalveolar lavage and transbronchial biopsies. MEASUREMENTS AND MAIN RESULTS: Mean alveolar-arterial gradient was 11.1 mm Hg +/- 8.5 and mean diffusion capacity was 73.0% +/- 20.0% of predicted. None of the 24 patients showed P. carinii or other pathogens on stains of bronchoalveolar lavage fluid. No patient had histologic evidence of P. carinii pneumonia. Transbronchial biopsy specimens showed chronic, nonspecific interstitial pneumonitis (11 of 23) and no pathologic abnormality (12 of 23). Six patients have developed P. carinii pneumonia during 2 to 18 months of follow-up. CONCLUSIONS: HIV-infected patients without pulmonary symptoms did not have detectable Pneumocystis organisms in bronchoalveolar lavage fluid or transbronchial biopsy specimens; but 11 of 23 had evidence of chronic, nonspecific interstitial pneumonitis. Pneumocystis organisms in a pulmonary specimen from a symptomatic patient probably indicate the cause of the pulmonary dysfunction even if only a few are detected.

Adult↗
PubMed1988

Indolent epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia in an intensive care unit traced to a contaminated blood gas analyzer.

An epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia occurred in the medical intensive care unit at the Clinical Center of the National Institutes of Health. Sixteen patients in the intensive care unit became colonized or infected with this organism in a 21-month period; whereas P. cepacia had been isolated only 16 times in the preceding 90 months from the entire hospital. Further analysis demonstrated a significant association of the epidemic cases with bloodstream isolation of the organism (p less than 0.001, Fisher's exact test). Mortality associated with bacteremia caused by P. cepacia was 38 percent. Intensive investigation of the intensive care unit and its surrounding environment eventually demonstrated that a blood gas analyzer in a satellite laboratory adjacent to the intensive care unit was the reservoir for the outbreak. Replacement of the machine resulted in termination of the outbreak, P. cepacia continues to represent an environmental threat to hospitalized patients.

Blood Gas Analysis↗
PubMed1988

Dysgonic fermenter 3-associated gastrointestinal disease in a patient with common variable hypogammaglobulinemia.

A gram-negative bacteria designated DF-3 was cultured on multiple occasions from stool samples of a patient with common variable hypogammaglobulinemia and chronic diarrhea. Antibiotic therapy resulted in elimination of the organism and resolution of the patient's symptoms. DF-3 has not been linked previously to human disease; because of its fastidious growth characteristics and unique isolation requirements, it may be a rarely identified cause of diarrhea and other gastrointestinal symptoms in immunocompromised patients.

Agammaglobulinemia↗
PubMed1988

Usefulness of pyridoxal-containing blood agar as a primary plating medium to enhance recovery of nutritionally deficient streptococci.

We evaluated the use of horse blood agar containing 0.0005% pyridoxal hydrochloride (HBAP) mainly for use as a primary plating medium for blood cultures, other sterile fluids, wounds, and abscesses in order to facilitate the isolation of nutritionally deficient streptococci (NDS). Our results showed that the addition of pyridoxal hydrochloride (pxl) permitted good growth of NDS within 24 h and did not inhibit or significantly alter the colony morphology of 34 different species of microorganisms and 296 isolates of beta hemolytic streptococci presumptively identified as Group A streptococci. The use of pxl-supplemented blood agar such as HBAP is recommended for primary plating as well as subculturing of blood cultures, and may also increase recovery of NDS from wounds and abscesses.

Agar↗
PubMed1988

Modified toluidine blue O stain for Pneumocystis carinii: further evaluation of some technical factors.

A modified toluidine blue O (TBO) stain for Pneumocystis carinii cysts was evaluated with regard to the influence of (i) the age and extent of use of the sulfation reagent, (ii) the source of TBO, (iii) the TBO content of the staining solution, and (iv) the amount of TBO present in the alcohol wash solutions. All TBOs evaluated, except for a new TBO obtained from Roboz Surgical Instrument Co., Inc., Washington, D.C., produced satisfactory results. Each lot of TBO should be quality controlled before use to ensure that the P. carinii cysts stain lavender against a blue background. We have ourselves decided to use only certified TBO with a high dye content. As extensively used sulfation reagent provided less satisfactory results than did either freshly prepared or 1-week-old unused sulfation reagent, we have decided to prepare fresh sulfation reagent at least weekly and to discard used sulfation reagent after 10 slides have been processed.

Animals↗
PubMed1988

Optimal use of the cytocentrifuge for recovery and diagnosis of Pneumocystis carinii in bronchoalveolar lavage and sputum specimens.

To facilitate the diagnosis of Pneumocystis carinii from bronchoalveolar lavage and sputum specimens, we have defined conditions for optimal use of the cytocentrifuge for this purpose. Centrifugation in the cytocentrifuge at 1,200 rpm for 10 min yielded the best recovery of P. carinii. To reliably ensure complete absorption of the fluid specimen from the cytocentrifuge chamber, it was necessary to use two absorption filters simultaneously. Different methods of treating induced sputum with mucolytic agents to process sputum with the cytocentrifuge were tried. Results of these studies and our current method for treating sputa are discussed. Comparisons of slides prepared by traditional centrifugation and by cytocentrifuge processing showed the latter to be equally effective for detecting P. carinii. The most prominent advantage of the cytocentrifuge was the much smaller area to review and consequently the shortened time required to read the slides.

Animals↗
PubMed1988

Intestinal infections in patients with the acquired immunodeficiency syndrome (AIDS). Etiology and response to therapy.

STUDY OBJECTIVE: To determine the frequency of pathogenic gastrointestinal microorganisms in patients with the acquired immunodeficiency syndrome (AIDS) and diarrhea, and to determine if treatment for identifiable microorganisms improves symptoms. DESIGN: Prospective, consecutive sample study. SETTING: Referral-based clinic and wards, National Institutes of Health. PATIENTS: Twenty of twenty-two consecutive homosexual males with AIDS and diarrhea, and 10 homosexual males with AIDS without diarrhea. INTERVENTIONS: All patients had a complete physical examination; serial stool examinations for viral, bacterial, fungal, and protozoan pathogens; and esophagogastroduodenoscopy and colonoscopy to obtain duodenal fluid and mucosal tissue to analyze for enteric pathogens or histopathology. Patients with diarrhea had a malabsorption evaluation. Patients with treatable pathogenic microorganisms received standard antimicrobial therapy. MEASUREMENTS AND MAIN RESULTS: The 20 patients with AIDS and diarrhea had greater weight loss, lower mean numbers of helper-inducer (OKT4) lymphocytes, and a higher incidence of extraintestinal opportunistic infections than the 10 patients without diarrhea. One or more enteric pathogen was identified in 17 of 20 patients (85%; 95% confidence interval [CI], 65% to 96%) with diarrhea. Only 1 patient without diarrhea was infected with an enteric pathogen. Nineteen of twenty patients with diarrhea and all 10 patients without diarrhea had chronic inflammatory changes in their intestinal biopsy specimens. Sixteen patients with identifiable enteric pathogens and diarrhea were treated; 11 (69%; 95% CI, 43% to 87%) showed microbiologic, histologic, or clinical improvement. CONCLUSIONS: Thorough diagnostic evaluation can lead to the identification of enteric pathogens in a high percentage of patients with AIDS and diarrhea. Specific therapy can lead to symptomatic improvement.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Detection of Mycobacterium avium-Mycobacterium intracellulare in blood cultures using concentrated and unconcentrated blood in conjunction with a radiometric detection system.

Studies were performed in order to determine optimal methods for isolating mycobacteria from blood. The combined use of a lysis-centrifugation (Isolator) system and a radiometric-detection system (Bactec) was compared to the use of either unconcentrated blood or centrifuged blood pellet in conjunction with the Bactec mycobacterial system. Results showed that for cultures with greater than 10 colony forming units (CFU) per ml of blood, the use of unconcentrated blood and centrifuged blood pellet was as sensitive as use of the Isolator concentrate. For cultures with lower colony counts (less than 10 CFU/ml), however, Isolator concentrate was consistently better than either centrifuged or unconcentrated blood. Since over half of our positive cultures had low colony counts, the use of Isolator concentrate inoculated into either a Bactec mycobacterial culture vial or onto Middlebrook agar slants is recommended over the use of either centrifuged blood pellet or unconcentrated blood inoculated into a Bactec mycobacterial culture vial.

Bacteriological Techniques↗
PubMed1987

Rapid identification of enterococci by pyrrolidonyl aminopeptidase activity (PYRase).

Group A streptococci and enterococci can be differentiated from other streptococci by their ability to cleave pyrrolidonyl beta-naphthylamide (PYRase). We evaluated two PYRase systems [Strep-A-Chek (SAC), E-Y Laboratories, San Mateo, CA; Strep-A-Fluor (SAF), BioSpec, Inc., Dublin, CA) for the presumptive identification of enterococci. Initially, 40 enterococcal and 21 nonenterococcal streptococci were tested, retrospectively. A prospective comparison of SAC and SAF to bile-esculin reaction (BE) was then incorporated into our routine procedure for the identification of non-beta-hemolytic streptococcal colonies from cultures. All isolates were speciated using standard biochemical tests. We encountered 85 enterococcal and 26 nonenterococcal isolates. Tests were performed on colonies from primary plates whenever possible (77 isolates). Sensitivity and specificity of both SAC and SAF were greater than 96% in identifying enterococci from routine cultures. These PYRase tests were cost-effective, easily adaptable to work-flow, and yielded results within 30 min. Thus, PYRase testing appears to be a reasonable alternative for the identification of enterococci in the clinical laboratory.

Aminopeptidases↗
PubMed1987

Medium for the simultaneous detection of pyocyanin and fluorescein pigments of Pseudomonas aeruginosa.

To help simplify the identification of Pseudomonas aeruginosa by clinical microbiology laboratories, the authors developed a new medium, pyocyanin-fluorescein agar (PFA), which enhances the production of both Pseudomonas pigments simultaneously. Production of pigments on PFA was equivalent to production on a pyocyanin agar (P agar) and a fluorescein agar (F agar) used in combination and was superior to either P agar or F agar used alone. The medium is simple to prepare and it detected pigment in 94% of P. aeruginosa isolates tested.

Culture Media↗
PubMed1987

Detection of Pneumocystis carinii by fluorescent-antibody stain using a combination of three monoclonal antibodies.

A combination of three monoclonal antibodies, two prepared against human and one against rat Pneumocystis carinii, was used in an indirect fluorescent-antibody stain (IFA) to diagnose P. carinii in both bronchoalveolar lavage and lung biopsy specimens. This combination of monoclonal antibodies was specific for P. carinii and yielded bright fluorescence of both P. carinii cysts and trophozoites. A total of 126 specimens from 93 patients were stained for P. carinii by a toluidine blue O stain and the monoclonal IFA. Forty-five (35.7%) of these were positive for P. carinii by toluidine blue O, and 43 (34.1%) were positive by IFA. There was 98.4% agreement between both methods, with no false-positive and two false-negative occurrences by IFA. An IFA procedure with monoclonal antibodies such as those used in these studies can provide a simple, fast, and sensitive method for diagnosing P. carinii pneumonia by microbiology laboratories.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Clinical features and therapeutic interventions in 17 cases of Bacillus bacteremia in an immunosuppressed patient population.

We retrospectively examined episodes of Bacillus bacteremia at a hospital with a large proportion of immunosuppressed patients. Seventeen episodes in 9.5 years met our case definition: two of two bottles of one blood culture or one of two bottles of two or more separately obtained blood cultures drawn on the same date. During the same period, there were 59 additional episodes in which a single blood culture had only one of two bottles positive for Bacillus species. Only 2 of 59 such episodes resulted in recurrent bacteremia (3%), as compared with 5 of 17 episodes meeting our case definition (29%) (P = 0.004). In four of five episodes complicated by recurrent bacteremia and in which appropriate antibiotics were used, a Hickman-Broviac catheter was in place and was not removed. We suggest that our case definition permits the differentiation of infection from contamination based on outcome and that patients with Bacillus bacteremia have chronic venous catheters removed as well as receive antibiotic treatment.

Adolescent↗
PubMed1987

Nonspecific interstitial pneumonitis: a common cause of pulmonary disease in the acquired immunodeficiency syndrome.

During a 4.4-year period, nonspecific interstitial pneumonitis was seen in 41 of 110 (38%) patients with the acquired immunodeficiency syndrome and accounted for 32% (48/152) of all episodes of clinical pneumonitis. Diffuse alveolar damage was typically a feature of nonspecific interstitial pneumonitis, but neither lung biopsy nor bronchoalveolar lavage detected a pathogen. Of these 41 patients, 13 had no associated pulmonary tumor and had not been exposed to pulmonary toxins, whereas 28 patients had either concurrent pulmonary Kaposi sarcoma, previous experimental therapies, or a history of pneumocystis pneumonia or drug abuse. Of these 41, 23 had normal chest radiographs. The clinical features of patients with nonspecific interstitial pneumonitis were similar to those of patients with pneumocystis pneumonia, although histologic findings showed less severe alveolar damage in patients with nonspecific interstitial pneumonitis (p less than 0.001). Pathologic evaluation and clinical follow-up suggest that many clinical episodes of pneumonitis in patients with the acquired immunodeficiency syndrome are due to nonspecific interstitial pneumonitis of unknown cause.

Acquired Immunodeficiency Syndrome↗