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Biomedical subjects

T M Daniel

Publications and source records attributed to T M Daniel.

At least 19 recordsLinked to original sources
PubMed2000

The origins and precolonial epidemiology of tuberculosis in the Americas: can we figure them out?

Paleologic evidence of tuberculosis in the precolonial Americas is reviewed to cast light on its origins and subsequent epidemiology. The genus Mycobacterium is an ancient one, and M. tuberculosis may have differentiated 20,400 to 15,300 years ago. The Americas were peopled by migrants from Asia in two major migrations, one occurring more than 20,000 years ago and the other 12,000 to 11,000 years ago. Tuberculosis reached the Americas with these migrants, persisting at a low level of endemnicity in small, dispersed population groups. Beginning about 1500 years ago, an epidemic of tuberculosis began, probably in the Andean region of South America. It did not reach or subsided in time to leave highly susceptible indigenous American populations at the time of European colonization.

Americas↗
PubMed1999

Membranous tracheobronchial injury repaired with gastric serosal patch.

This unusual case involves pharyngolaryngoesophagectomy complicated by injury to the membranous trachea and right bronchus. Repair was possible after partial sternal split and elevation of the tracheostoma through the anterior mediastinum, pulling the stomach to the neck, and using the stomach as a patch to repair the injury to the membranous portion of the airway.

Bronchi↗
PubMed1999

Old Testament biblical references to tuberculosis.

Two probable references to tuberculosis are found in Old Testament books of the Bible dating to a time when the Israelites lived in Egypt, which is known from archeological evidence to be an area where tuberculosis was then prevalent. Other putative biblical references to tuberculosis are less credible.

Bible↗
PubMed1999

Lung air spaces: MR imaging evaluation with hyperpolarized 3He gas.

Thirty-two magnetic resonance imaging examinations of the lungs were performed in 16 subjects after inhalation of 1-2 L of helium 3 gas that was laser polarized to 10%-25%. The distribution of the gas was generally uniform, with visualization of the fissures in most cases. Ventilation defects were demonstrated in smokers and in a subject with allergies. The technique has potential for evaluating small airways disease.

Administration, Inhalation↗
PubMed1998

The early history of tuberculosis in central East Africa: insights from the clinical records of the first twenty years of Mengo Hospital and review of relevant literature.

SETTING: Mengo Hospital, in present day Kampala, Uganda, 100 years ago. OBJECTIVE: To determine the presence of tuberculosis in the Bagandan population of central East Africa and elsewhere in Africa at the time of early explorations by Europeans. DESIGN: The case records kept by Albert Cook for two decades beginning in 1897, 35 years after the first visit of Speke to this region, were reviewed for evidence of tuberculosis among Bagandans. Writings of other contemporary medical observers were reviewed for evidence of tuberculosis in pre- and early-colonial Africa. RESULTS: Well documented cases of tuberculosis were observed by Cook beginning in 1897. A minimum total of 93 cases of tuberculosis were included in 26 806 admissions to Mengo Hospital from 1897 through 1916. No secular trend in the prevalence of tuberculosis among patients admitted was apparent. A review of the prior literature concerning tuberculosis in precolonial Africa suggests that tuberculosis may have been present in several regions prior to European exploration, but was probably absent elsewhere. CONCLUSIONS: The concept of all of Africa and all of the people of Africa as virgin soil for tuberculosis is rooted in an archaic Eurocentric view of Africa, and cannot be supported today by available data.

Africa↗
PubMed1997

MR imaging and spectroscopy using hyperpolarized 129Xe gas: preliminary human results.

Using a new method of xenon laser-polarization that permits the generation of liter quantities of hyperpolarized 129Xe gas, the first 129Xe imaging results from the human chest and the first 129Xe spectroscopy results from the human chest and head have been obtained. With polarization levels of approximately 2%, cross-sectional images of the lung gas-spaces with a voxel volume of 0.9 cm3 (signal-to-noise ratio (SNR), 28) were acquired and three dissolved-phase resonances in spectra from the chest were detected. In spectra from the head, one prominent dissolved-phase resonance, presumably from brain parenchyma, was detected. With anticipated improvements in the 129Xe polarization system, pulse sequences, RF coils, and breathing maneuvers, these results suggest the possibility for 129Xe gas-phase imaging of the lungs with a resolution approaching that of current conventional thoracic proton imaging. Moreover, the results suggest the feasibility of dissolved-phase imaging of both the chest and brain with a resolution similar to that obtained with the gas-phase images.

Adult↗
PubMed1997

Estimation of the annual risk of tuberculosis infection for white men in the United States.

The annual risk of tuberculous infection for white men in the United States was estimated from published tuberculin surveys and found to be related to tuberculosis incidence as reflected in the annual case rate during the past 3 decades, with a constant ratio of approximately 150. It is currently estimated to be 0.03%/year. The technique developed for this estimation is not complex and should be applicable to other segments of the population for which suitable data are available.

Databases, Factual↗
PubMed1997

Radiology of pulmonary turberculosis and human immunodeficiency virus infection in Gulu, Uganda.

Pulmonary tuberculosis is a major complication of human immunodeficiency virus (HIV) infection. The radiographic manifestations of pulmonary tuberculosis in HIV-infected patients are not typical of those seen in immunologically normal individuals. We sought to determine whether these manifestations provide clues to the pathogenesis of tuberculosis in HIV-infected persons. The radiographic manifestations of pulmonary tuberculosis were reviewed and classified in 82 HIV-positive and 53 HIV-negative tuberculous patients in Gulu, Uganda. Pulmonary presentations of tuberculosis were more acute in HIV-positive patients, and often included hilar or mediastinal adenopathy and pleural effusions, findings typical of primary tuberculosis in immunologically normal individuals. Many patients also had chronic forms of tuberculosis, either alone or in combination with acute disease. The findings of this study support the hypothesis that reactivation of latent infections and progression of pre-existent chronic disease produce a substantial portion of the tuberculosis burden of HIV-positive persons in Uganda. Tuberculosis control efforts should extend beyond efforts at decreasing transmission of new infections.

AIDS-Related Opportunistic Infections↗
PubMed1996

Induction of monocyte expression of tumor necrosis factor alpha by the 30-kD alpha antigen of Mycobacterium tuberculosis and synergism with fibronectin.

Native 30-kD antigen, also known as alpha antigen, is a fibronectin-binding protein that is secreted by live Mycobacterium tuberculosis. This antigen may play an important biological role in the host-parasite interaction since it elicits delayed type hypersensitivity response and protective immunity in vivo and T lymphocyte blastogenesis and IFN-gamma production in vitro. In the present study, we show that, TNF-alpha protein is produced in monocyte culture supernatants in response to 30-kD antigen and the level is as high as that to purified protein derivative of M. tuberculosis. This stimulatory effect was not due to contamination with either bacterial lipopolysaccharide or mycobacterial lipoarabinomannan. The preincubation of monocytes with plasma fibronectin significantly enhanced the release of TNF-alpha into the culture supernatants in response to 30-kD antigen. This effect was blocked by polygonal antibody to plasma fibronectin. In contrast, the monocytic cell line U937 failed to release TNF-alpha protein in the culture supernatants in response to 30-kD antigen with or without preincubation with plasma fibronectin. To determine whether this observation was due to differential binding of the 30-kD to fibronectin on these cells, a cell based ELISA was used. Pretreatment of monocytes with fibronectin enhanced their binding of the 30-kD antigen. U937 cells bound the 30-kD antigen weakly with or without fibronectin pretreatment. These results indicate that 30-kD antigen which is a known secretary antigen of M. tuberculosis is a stimulus for human monocytes to express TNF-alpha and that stimulatory effect may be mediated through plasma fibronectin.

Antigens, Bacterial↗
PubMed1996

Origin and interstate spread of a New York City multidrug-resistant Mycobacterium tuberculosis clone family.

OBJECTIVE: To determine whether isolates of Mycobacterium tuberculosis from New York and elsewhere that are resistant to four or more primary antimicrobial agents and responsible for widespread disease in the 1990s represent a newly emerged clone or a heterogeneous array of unrelated organisms. SETTING: New York City area and selected locations in the United States. PATIENTS: M tuberculosis isolates from 1953 patients in New York and multidrug-resistant isolates from six patients from other US communities. DESIGN: Convenience sample of all M tuberculosis strains (M tuberculosis isolates resistant to rifampin, streptomycin, isoniazid, and ethambutol, and sometimes ethionamide, kanamycin, capreomycin, or ciprofloxacin) submitted to the Public Health Research Institute Tuberculosis Center since 1991 and samples submitted to the Centers for Disease Control and Prevention from throughout the United States. The samples submitted were representative of the New York City strains of M tuberculosis. MAIN OUTCOME MEASURE: Characterization of resistant M tuberculosis strains studied by IS6110 and polymorphic GC-rich repetitive sequence (PGRS) hybridization patterns, multiplex polymerase chain reaction (PCR) analysis, and automated DNA sequencing of genes containing mutations associated with resistance to rifampin (rpoB), isoniazid (katG and inhA locus), and streptomycin (strA and rrs). RESULTS: Multidrug-resistant M tuberculosis isolates were recovered from 253 New York City patients and had the same or closely allied IS6110 and PGRS patterns, multiplex PCR type, and gene mutations associated with resistance to rifampin, isoniazid, and streptomycin. Isolates with these same molecular characteristics were recovered from patients in Florida and Nevada, health care workers in Atlanta, Ga, and Miami, Fla, and an individual who recently moved from New York City to Denver, Colo, and caused disease or skin test conversion in at least 12 people in a nursing home environment. CONCLUSIONS: The results document the molecular origin and spread of progeny of a closely related family of multidrug-resistant M tuberculosis strains that have recently shared a common ancestor and undergone clonal expansion. The multidrug-resistant phenotype in these organisms arose by sequential acquisition of resistance-conferring mutations in several genes, most likely as a consequence of antibiotic selection of randomly occurring mutants in concert with inadequately treated infections. Dissemination of these difficult-to-treat bacteria throughout New York City and to at least four additional US cities has adverse implications for tuberculosis control in the 21st century.

Antitubercular Agents↗
PubMed1996

Postpneumonectomy syndrome with an ipsilateral aortic arch after left pneumonectomy.

BACKGROUND: Previous reports have described bronchial obstruction after left pneumonectomy (so-called post-pneumonectomy syndrome) in the presence of a right aortic arch with the bronchus being compressed between the ascending aorta and thoracic spine. This study reports on 4 patients with left postpneumonectomy syndrome in the presence of a normally located left aortic arch and ascending thoracic aorta. METHODS: The case histories of 4 patients with this syndrome were reviewed and several features common to all 4 were noted. In each case, the obstruction was thought to be due to a clockwise rotation of the mediastinum with bronchial compression occurring between the right main pulmonary artery and thoracic spine. RESULTS: Three patients were treated by repositioning of the mediastinum, and all 3 obtained relief of their dyspnea. In these cases, permanent repositioning was ensured by the insertion of a prosthesis filled with saline solution. The fourth patient was successfully treated by resection of a portion of the adjacent thoracic vertebra. CONCLUSIONS: Postpneumonectomy syndrome can occur after a left pneumonectomy in the absence of a right aortic arch. We suggest that mediastinal repositioning with a prosthesis filled with saline solution is simple, is safe, and results in complete relief of preoperative symptoms.

Adult↗
PubMed1996

Bacille Calmette Guérin immunization of health care workers exposed to multidrug-resistant tuberculosis: a decision analysis.

SETTING: North American health care workers with exposure to multidrug-resistant tuberculosis. OBJECTIVE: To evaluate the relative utilities of bacille Calmette Guérin (BCG) immunization and post-infection chemoprophylaxis for the protection of health care workers exposed to multidrug-resistant Mycobacterium tuberculosis. DESIGN: Decision analysis using SMLTREE software and published data for probabilities. RESULTS: BCG vaccination was preferred by a small margin over post-infection chemoprophylaxis. Sensitivity analysis revealed that possible changes in probability values used tended to tilt the result towards use of BCG vaccination. The threshold for protective efficacy of BCG vaccination was 26%. CONCLUSIONS: BCG vaccination should be considered for health care workers in environments where there is a substantial risk of exposure to multidrug-resistant tuberculosis.

Antitubercular Agents↗
PubMed1996

Lung volume reduction surgery. Case selection, operative technique, and clinical results.

OBJECTIVE: A clinical study was undertaken to define optimal preoperative strategies and intraoperative techniques that would result in the least morbidity and maximum physiologic improvements in patients with end-stage emphysema selected for lung volume reduction surgery. BACKGROUND: Lung volume reduction surgery recently has been advocated as an alternative or a bridge to lung transplantation for patients with end-stage chronic obstructive pulmonary disease. The risks, benefits, and long-term results have not been clarified. METHODS: Twenty-six patients underwent lung volume reduction surgery with a 3-month follow-up on 17 patients. Preoperative and postoperative changes in pulmonary function parameters, quality of life, and oxygen requirement were analyzed. The value of preoperative localization of diseased lung segments and how this affects intraoperative resection is addressed. RESULTS: Forty-nine percent improvement in FEV1 (forced expiratory volume in 1 second) and 23% improvement in FVC (forced vital capacity) were seen after lung volume reduction surgery. Supplemental oxygen requirement was decreased and 79% of patients reported a much better quality of life. Mortality was 3.8% and air leak morbidity was 18%. CONCLUSIONS: Lung volume reduction surgery can predictably improve objective and subjective pulmonary function in selected patients with end-stage emphysema with low morbidity and mortality. Careful patient selection, accurate preoperative localization of diseased target areas, skilled anesthetic technique, meticulous operative approach, and intense postoperative support are essential to achieve favorable results.

Adult↗
PubMed1996

Thoracoscopic sympathectomy.

Thoracoscopic sympathectomy has become the most widely used approach to cervicothoracic sympathectomy. Appropriate selection of cases and a knowledge of the regional anatomy are essential in achieving good clinical results. The physiology and anatomy of the upper thoracic sympathectomy system and the indications, contraindications, and complications of the operation are described. The technique of the operation as done at the University of Virginia is then presented in a step-by-step manner.

Ganglia, Sympathetic↗