Biomedical subjects

Dana Wolf

Publications and source records attributed to Dana Wolf.

7 recordsLinked to original sources

PubMed2006

Identification of risk factors for infection in an outbreak of Mycoplasma pneumoniae respiratory tract disease.

BACKGROUND: Mycoplasma pneumoniae is one of the most common pathogens that causes community-acquired respiratory tract infection. Outbreaks are well known, and all age groups are susceptible. An outbreak in an army training unit afforded an opportunity to identify possible risk factors for morbidity. METHODS: An outbreak of respiratory illness that occurred in a unit comprising 91 trainees was investigated and analyzed as a cohort study. M. pneumoniae infection was suspected on clinical grounds and was confirmed by polymerase chain reaction, culture, and serologic testing. Data regarding medical history, symptoms, signs, and laboratory tests were collected. RESULTS: During a period of 12 days, 41 soldiers (45.1%) had respiratory illnesses, of which 10 (11.0%) were pneumonia. Comparison of symptomatic and asymptomatic individuals revealed that smoking was associated with higher rates of disease (risk ratio, 2.1; 95% confidence interval [CI], 1.3-3.2; P<.005) and seroconversion (risk ratio, 2; 95% CI, 1.2-3.4; P=.03). In multivariate analysis, both lower acute immunoglobulin G values (adjusted odds ratio, 7.8; 95% CI, 1.4-42.5; P=.018) and smoking (adjusted odds ratio, 5.6; 95% CI, 1.5-20.4; P=.01) were associated with symptomatic infection; stratification according to smoking status revealed that immunoglobulin G levels among nonsmokers were protective. Patients who had pneumonia had lower lymphocyte counts (1400+/-258 vs. 2000+/-465 cells/microL; P=.001). CONCLUSIONS: Smoking and lower preexisting immunoglobulin G levels were strongly associated with M. pneumoniae respiratory infection. These findings emphasize the importance of immunity and cessation of smoking for the prevention of disease. The high attack rate emphasizes the extent of infection transmission among healthy persons living in close contact.

Cohort Studies↗

PubMed2004

Insight into the intrinsic sensitivity of the PCR assay used to detect CMV infection in amniotic fluid specimens.

BACKGROUND: PCR detection of human cytomegalovirus (HCMV) DNA in amniotic fluid (AF) is the most sensitive tool for diagnosis of fetal infection, but has sub-optimal sensitivity. It has been suggested that inhibition by AF reduces the sensitivity of this assay, however this assumption has never been thoroughly studied. Several PCR assays have been shown to improve sensitivity, but comparative studies are insufficient to choose the optimal approach. OBJECTIVES: To assess the effect of AF inhibition on PCR sensitivity and to determine the most sensitive assay for diagnosing fetal infection. STUDY DESIGN: Plasmid containing HCMV DNA was tested by PCR, in water and in non-infected AF, to assess the inhibitory effect of AF. Twenty-three AF-infected samples were tested by various PCR protocols. AF supernatant, with or without DNA extraction, and AF cells, were assayed by single-round and semi-nested PCR. Viral load was measured in the supernatant by a commercial quantitative PCR kit. RESULTS: The plasmid model demonstrated that single-round PCR was 2000-fold less sensitive in AF compared with water. Semi-nested PCR was only 10-fold less sensitive. Single-round PCR was 30% sensitive in HCMV-infected AF supernatants, and detected viral loads higher than 2.3 x 10(6) viral copies/ml. Extraction of DNA from the supernatant increased the sensitivity of this assay to 89% and the detection limit to 5.2 x 10(4) copies/ml. Semi-nested PCR performed on supernatant, with and without DNA extraction, was 96% and 100% sensitive, respectively, with a detection threshold of 3.8 x 10(3) copies/ml. Single-round and semi-nested PCR were 89% and 100% sensitive, respectively, in cells. The commercial quantitative PCR assay was 100% sensitive. CONCLUSIONS: AF supernatant is inhibitory to PCR. The two most sensitive assays were semi-nested PCR performed on DNA extracted from the supernatant and the commercial quantitative PCR kit. Of these two, the latter is standardized, non-labor-intensive, and allows minimal opportunity for contamination, thereby making it the preferred method for diagnosis.

Adult↗

PubMed2004

Global genetic diversity of human metapneumovirus fusion gene.

We analyzed 64 human metapneumovirus strains from eight countries. Phylogenetic analysis identified two groups (A and B, amino acid identity 93%-96%) and four subgroups. Although group A strains predominated, accounting for 69% of all strains, as many B as A strains were found in persons >3 years of age.

Adolescent↗

PubMed2003

Late cytomegalovirus disease following liver transplantation.

The widespread use of antiviral prophylaxis or preemptive therapy among orthotopic liver transplantation (OLT) recipients has reduced the occurrence of early cytomegalovirus (CMV) disease. Late disease is increasingly reported. Little is known about CMV disease occurring beyond the first year after transplantation. The aim of this study was to evaluate the occurrence of CMV disease two or more years after OLT and to determine its risk factors and clinical features. Eighty-one consecutive OLT recipients followed for 2 years or longer after transplantation were included in the study. Data were collected on demographic and clinical variables, clinical presentation, treatment, and outcome of late CMV disease. Late CMV disease occurred in 7/81 liver recipients (8.5%) at a mean time of 5.9 years after OLT (range: 3.5--9.3, median: 6.3 years). All seven patients were women, with a mean age of 47.7 years (range: 26--60, median: 59 years). There was no association between the development of late CMV disease and the occurrence of rejection episodes, treatment with corticosteroids, or the early use of antiviral prophylaxis. Clinical presentation included fever and disturbed liver functions in all patients, one patient had concurrent CMV pneumonitis and one CMV retinitis. Though all patients responded to ganciclovir, two had recurrent disease episodes and one patient died of secondary bacterial sepsis. Late-onset CMV disease can occur several years after OLT. Although it manifests classic clinical features of early disease, it is not associated with traditional risk factors and its pathogenesis may differ from that of early disease.

Adult↗

PubMed2003

Enteroviruses and sudden deafness.

A young, healthy man presented with sudden severe sensorineural hearing loss and tinnitus. The results of the workup and neuroimaging were normal, as were the auditory brain stem responses. Methylprednisolone pulse therapy was associated with significant hearing improvement within 10 days. A history of a short self-limited febrile illness preceding admission (with headache, photophobia, myalgia and fatigue), a raised serum C-reactive protein level and transient leukopenia suggested an infectious cause. Lumbar puncture revealed a mononuclear pleocytosis of the cerebrospinal fluid, with negative cultures but positive polymerase chain reaction test results for enterovirus, which was later cultured from the patient's stool. The patient's wife and baby had had a similar febrile illness without hearing loss 10 days earlier, and an outbreak of enterovirus meningitis was identified in the area, which was associated with familial clustering and echovirus serotype 4 infection. The varied causes of sudden sensorineural hearing loss, which should include enterovirus, are reviewed here.

Adult↗

PubMed2002

Exacerbation of pulmonary sarcoidosis after liver transplantation.

Patients with hepatic sarcoidosis rarely require orthotopic liver transplantation (OLT). Progression of granulomatous activity involving other organs after OLT has rarely been described. We describe a 32-year-old woman who underwent liver transplantation for sarcoidosis-associated end-stage liver disease. She presented 4 years later with shortness of breath, hilar lymphadenopathy, and interstitial lung abnormalities. Liver functions were normal. Open lung biopsy results revealed granulomata compatible with sarcoidosis. The patient made a complete recovery after corticosteroid treatment. To the best of our knowledge, this is a first description of severe exacerbation of pulmonary sarcoidosis in an immunosuppressed patient who underwent liver transplantation for sarcoidosis-associated liver disease.

Adult↗

PubMed2002

Pivotal role of CEACAM1 protein in the inhibition of activated decidual lymphocyte functions.

Lymphocytes in direct contact with embryonic extravillous trophoblasts constitute more than 40% of decidual cells and appear to play major roles in implantation and early gestation. A unique subset of NK cells, making up 70-80% of decidual lymphocytes, express high levels of CD56 but lack CD16. We have recently demonstrated a novel class I MHC-independent inhibitory mechanism of NK cell cytotoxicity that is mediated by CEACAM1 homotypic interactions. This mechanism is used by some melanoma cells to avoid attack, mainly by CD16(-) NK cells. We now demonstrate that CEACAM1 is expressed on primary extravillous trophoblasts and is upregulated on the vast majority of IL-2-activated decidual lymphocytes, including NK, T, and NKT cells. Importantly, we present evidence that CEACAM1 interactions inhibit the lysis, proliferation, and cytokine secretion of activated decidual NK, T, and NKT cells, respectively. In vivo analysis of decidual lymphocytes isolated from cytomegalovirus-infected (CMV-infected) pregnant women revealed a dramatic increase in the expression of CEACAM1. Finally, we suggest that a novel ligand for this adhesion molecule is present on the surface of CMV-infected fibroblasts. These combined results demonstrate a major role for the CEACAM1 protein in controlling local decidual immune responses.

Antigens, CD↗