Biomedical subjects

Vee J Gill

Publications and source records attributed to Vee J Gill.

6 recordsLinked to original sources

PubMed2003

Reinfection, rather than persistent infection, in patients with chronic granulomatous disease.

Chronic granulomatous disease (CGD) is characterized by severe recurrent infections with Staphylococcus aureus, certain gram-negative rods, Nocardia species, and fungi. When infections with the same species recur, they may represent relapses or new infections. We collected organisms from infections that occurred between 1992 and 2000 in patients with CGD and determined the biochemical phenotypes, in vitro antibiotic susceptibility patterns, and pulsed-field gel electrophoresis (PFGE) patterns of the organisms causing the initial and recurrent infections. Recurrence of infection with Burkholderia cepacia or Serratia marcescens was caused by a new strain in 9 of 10 cases (P=.001). Recurrent S. aureus infections were caused by new strains in 7 of 8 cases (P=.006). In patients with CGD, recurrence of infection with the same bacterial species after appropriate antibiotic therapy usually represents new infection.

Adolescent↗

PubMed2002

Brevibacterium endocarditis: a first report.

There are few case reports of infections caused by Brevibacterium species, and there have been no previously reported cases of endocarditis caused by any of the 6 known species of Brevibacterium. We report the first case of Brevibacterium endocarditis (caused by Brevibacterium otitidis) in a patient with prosthetic heart valves. The patient responded to 6 weeks of treatment with vancomycin and 2 weeks with gentamicin, and she has been receiving long-term maintenance therapy with oral azithromycin.

Actinomycetales Infections↗

PubMed2002

Phase I study of the intravenous administration of attenuated Salmonella typhimurium to patients with metastatic melanoma.

PURPOSE: A strain of Salmonella typhimurium (VNP20009), attenuated by chromosomal deletion of the purI and msbB genes, was found to target to tumor and inhibit tumor growth in mice. These findings led to the present phase I study of the intravenous infusion of VNP20009 to patients with metastatic cancer. PATIENTS AND METHODS: In cohorts consisting of three to six patients, 24 patients with metastatic melanoma and one patient with metastatic renal cell carcinoma received 30-minute intravenous bolus infusions containing 10(6) to 10(9) cfu/m(2) of VNP20009. Patients were evaluated for dose-related toxicities, selective replication within tumors, and antitumor effects. RESULTS: The maximum-tolerated dose was 3 x 10(8) cfu/m(2). Dose-limiting toxicity was observed in patients receiving 1 x 10(9) cfu/m(2), which included thrombocytopenia, anemia, persistent bacteremia, hyperbilirubinemia, diarrhea, vomiting, nausea, elevated alkaline phosphatase, and hypophosphatemia. VNP20009 induced a dose-related increase in the circulation of proinflammatory cytokines, such as interleukin (IL)-1beta, tumor necrosis factor alpha, IL-6, and IL-12. Focal tumor colonization was observed in two patients receiving 1 x 10(9) cfu/m(2) and in one patient receiving 3 x 10(8) cfu/m(2). None of the patients experienced objective tumor regression, including those patients with colonized tumors. CONCLUSION: The VNP20009 strain of Salmonella typhimurium can be safely administered to patients, and at the highest tolerated dose, some tumor colonization was observed. No antitumor effects were seen, and additional studies are required to reduce dose-related toxicity and improve tumor localization.

Adult↗

PubMed2002

Development and evaluation of a quantitative, touch-down, real-time PCR assay for diagnosing Pneumocystis carinii pneumonia.

A rapid (time to completion, <4 h, including DNA extraction) and quantitative touch-down (QTD) real-time diagnostic Pneumocystis carinii PCR assay with an associated internal control was developed, using fluorescence resonance energy transfer (FRET) probes for detection. The touch-down procedure significantly increased the sensitivity of the assay compared to a non-touch-down procedure. Tenfold serial dilutions of a cloned target were used as standards for quantification. P. carinii DNA has been detected in respiratory specimens from patients with P. carinii pneumonia (PCP) and from patients without clinical evidence of PCP. The latter probably represents colonization or subclinical infection. It is logical to hypothesize that quantification might prove helpful in distinguishing between infected and colonized patients: the latter group would have lower copy numbers than PCP patients. A blinded retrospective study of 98 respiratory samples (49 lower respiratory tract specimens and 49 oral washes), from 51 patients with 24 episodes of PCP and 34 episodes of other respiratory disease, was conducted. PCR-positive samples from colonized patients contained a lower concentration of P. carinii DNA than samples from PCP patients: lower respiratory tract samples from PCP and non-PCP patients contained a median of 938 (range, 2.4 to 1,040,000) and 2.6 (range, 0.3 to 248) (P < 0.0004) copies per tube, respectively. Oral washes from PCP and non-PCP patients contained a median of 49 (range, 2.1 to 2,595) and 6.5 (range, 2.2 to 10) (P < 0.03) copies per tube, respectively. These data suggest that this QTD PCR assay can be used to determine if P. carinii is present in respiratory samples and to distinguish between colonization and infection.

Bronchoalveolar Lavage Fluid↗

PubMed2002

Development of a rapid real-time PCR assay for quantitation of Pneumocystis carinii f. sp. carinii.

A method for reliable quantification of Pneumocystis carinii in research models of P. carinii pneumonia (PCP) that is more convenient and reproducible than microscopic enumeration of organisms would greatly facilitate investigations of this organism. We developed a rapid quantitative touchdown (QTD) PCR assay for detecting P. carinii f. sp. carinii, the subspecies of P. carinii commonly used in research models of PCP. The assay was based on the single-copy dihydrofolate reductase gene and was able to detect <5 copies of a plasmid standard per tube. It was reproducibly quantitative (r = 0.99) over 6 log values for standards containing > or =5 copies/tube. Application of the assay to a series of 10-fold dilutions of P. carinii organisms isolated from rat lung demonstrated that it was reproducibly quantitative over 5 log values (r = 0.99). The assay was applied to a recently reported in vitro axenic cultivation system for P. carinii and confirmed our microscopy findings that no organism multiplication had occurred during culture. For all cultures analyzed, QTD PCR assays showed a decrease in P. carinii DNA that exceeded the expected decrease due to dilution of the inoculum upon transfer. In conclusion, a rapid, sensitive, and reproducible quantitative PCR assay for P. carinii f. sp. carinii has been developed and is applicable to in vivo as well as in vitro systems. The assay should prove useful for conducting studies in which quantification of organism burden or growth assessment is critical, such as in vitro antimicrobic susceptibility testing or in vivo immunopathological experiments.

Animals↗

PubMed2002

Large-scale screening of nasal swabs for Bacillus anthracis: descriptive summary and discussion of the National Institutes of Health's experience.

In October 2001, a letter containing a large number of anthrax spores was sent through the Brentwood post office in Washington, D.C., to a United States Senate office on Capitol Hill, resulting in contamination in both places. Several thousand people who worked at these sites were screened for spore exposure by collecting nasal swab samples. We describe here a screening protocol which we, as a level A laboratory, used on very short notice to process a large number of specimens (3,936 swabs) in order to report preliminary results as quickly as possible. Six isolates from our screening met preliminary criteria for Bacillus anthracis identification and were referred for definitive testing. Although none of the isolates was later confirmed to be B. anthracis, we studied these isolates further to define their biochemical characteristics and 16S rRNA sequences. Four of the six isolates were identified as Bacillus megaterium, one was identified as Bacillus cereus, and one was an unidentifiable Bacillus sp. Our results suggest that large-scale nasal-swab screening for potential exposure to anthrax spores, particularly if not done immediately postexposure, may not be very effective for detecting B. anthracis but may detect a number of Bacillus spp. that are phenotypically very similar to B. anthracis.

Anthrax↗