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Dive into the research topics where Michael C. Boyars is active.

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Featured researches published by Michael C. Boyars.


American Journal of Clinical Pathology | 2001

Clinical and pathologic features of Mycobacterium fortuitum infections. An emerging pathogen in patients with AIDS.

Michael B. Smith; Vicki J. Schnadig; Michael C. Boyars; Gail L. Woods

The clinical and pathologic features of Mycobacterium fortuitum infection in 11 patients with AIDS were characterized. Nine patients had cervical lymphadenitis; 2 had disseminated infection. The infection occurred late in the course of AIDS, and the only laboratory abnormality seen in more than half of patients (7/11) was relative monocytosis. Absolute monocytosis also was seen in 4 of 11 patients. In both cytologic and histologic preparations, the inflammatory pattern was suppurative with necrosis or a mixed suppurative-granulomatous reaction. M fortuitum, a thin, branching bacillus, stained inconsistently in direct smear and histologic preparations. Staining was variable with Gram, auramine, Brown-Hopps, Gram-Weigert, Kinyoun, Ziehl-Neelsen, modified Kinyoun, and Fite stains. Organisms, when present, were always seen in areas of suppurative inflammation. Incorrect presumptive diagnosis, based on misinterpretation of clinical signs and symptoms or on erroneous identification of M fortuitum bacilli as Nocardia species, led to a delay in proper therapy for 7 of 11 patients. Definitive therapy after culture identification resulted in complete resolution of infection in all patients except 1.


Archives of Pathology & Laboratory Medicine | 2003

Pathologic features of Mycobacterium kansasii infection in patients with acquired immunodeficiency syndrome.

Michael B. Smith; Claudia P. Molina; Vicki J. Schnadig; Michael C. Boyars; Judith F. Aronson

CONTEXT Mycobacterium kansasii is a slow-growing photochromogenic mycobacterium that may infect patients with human immunodeficiency virus (HIV) late in the course of acquired immunodeficiency syndrome (AIDS). The clinical features of pulmonary and extrapulmonary infections have been described in the literature; however, the pathology of infection has not been adequately addressed. OBJECTIVE This report describes the pathologic features of 12 cases of M kansasii infection in patients with AIDS. DESIGN The medical records, autopsy protocols, cytologic material, and histologic material from patients with AIDS and concomitant M kansasii infection at a tertiary-care medical center during 1990-2001 were reviewed. RESULTS Twelve cases were identified, 6 by autopsy, 5 of which were diagnosed postmortem. Four of the 12 cases had cytologic material and 4 cases had histologic biopsies available for review. Pulmonary infection was most common (9/12), and all patients in whom thoracic lymph nodes were assessed showed involvement (7/7). Abdominal infection was less frequent, with only 1 of 6, 2 of 6, and 2 of 6, demonstrating liver, spleen, and abdominal lymph node infection, respectively. Isolated infections without documented pulmonary infection included brain abscess (n = 1), ulnar osteomyelitis (n = 1), and paratracheal mass (n = 1). Cytologic and histologic material showed a wide range of inflammatory reactions, including granulomas with and without necrosis, neutrophilic abscesses, spindle-cell proliferations, and foci of granular eosinophilic necrosis. The M kansasii bacillus was characteristically long, coarsely beaded, and frequently showed folded, bent, or curved ends. Intracellular bacilli were randomly or haphazardly distributed within histiocytes. CONCLUSION Mycobacterium kansasii infection produces predominantly pulmonary infection in late-stage AIDS with a high incidence of thoracic lymph node involvement and a much lower incidence of dissemination to other sites. Infection is manifest as a wide variety of inflammatory reactions on cytology and histology; however, the characteristic appearance of the bacillus on acid-fast bacilli stain and its intracellular arrangement in histiocytes can allow a presumptive identification.


Archives of Pathology & Laboratory Medicine | 2000

Generalized tuberculosis in the acquired immune deficiency syndrome : A clinicopathologic analysis based on autopsy findings

Michael B. Smith; Michael C. Boyars; Sparks P. Veasey; Gail L. Woods

OBJECTIVE Generalized, or hematogenously disseminated, tuberculosis (TB) in patients with the acquired immune deficiency syndrome (AIDS) has been associated with a high incidence of cases remaining undiagnosed until postmortem. To better characterize generalized TB in the setting of AIDS, this report describes the clinical, laboratory, radiologic, and pathologic features of 20 fatal cases. DESIGN The medical records, autopsy protocols, and histologic material from patients with AIDS and concomitant TB were reviewed. All patients were autopsied at a tertiary care medical center during the years 1985-1997. RESULTS In 50% of our 20 cases, diagnosis was not made until postmortem. Signs and symptoms were few, including the absence of fever (temperature > or = 38 degrees C) in 55% of patients. Consistent laboratory abnormalities of a nonspecific nature were limited to hyponatremia (sodium <135 mmol/L) in 60%. Both peripheral and deep (thoracic and abdominal) lymphadenopathy, unusual in adults with TB, occurred in 45% and 95% of cases, respectively. In contrast to previous reports, all of the 6 cases of tuberculous meningitis presented as acute meningitis with a predominance of neutrophils in cerebrospinal fluid. Necrotizing encephalitis with extension of the acute inflammation into the superficial cortex was seen in all cases and tuberculous brain abscesses occurred in 50% of cases, a higher frequency than previously reported. Despite lung involvement in 90% of the cases, 33% of chest radiographs were interpreted as normal and disseminated mycobacterial disease was not suggested in the radiograph report in any of the other cases. Soft tissue abscesses in uncharacteristic locations such as the neck, mediastinum, and perirectal area occurred in these patients. Histologically, 95% of organs sampled showed inflammatory foci characterized by extensive necrosis with numerous neutrophils and/or karyorrhectic debris, numerous acid-fast bacilli, few or no epithelioid histiocytes, and no Langhans giant cells. CONCLUSION Clinically and pathologically, generalized TB in the setting of AIDS is characterized by either unusual features or a lack of the typical features described for generalized TB in patients who do not have AIDS. This absence of classic features contributes to the high incidence of cases that remain undiagnosed until postmortem examination.


The American Journal of Medicine | 1996

Results of a multicenter study of nebulized inhalant bronchodilator solutions

Donald P. Tashkin; Eugene R. Bleecker; Sheldon R. Braun; Sammy Campbell; Arthur C. Degraff; David W. Hudgel; Michael C. Boyars; Steven A. Sahn

The efficacy, persistence of bronchodilator action, and safety of the quaternary ammonium anticholinergic agent, ipratropium bromide (500 microgram), and placebo were compared when each was added in solution form to the beta-adrenergic agonist solution, metaproterenol sulfate (15 mg), and administered three times daily for 12 weeks to a total of 213 patients with chronic obstructive pulmonary disease (COPD). Subjects had a mean forced expiratory volume in 1 second (FEV1) of approximately 1 liter (37% of predicted) and were permitted to use nonanticholinergic therapy for COPD throughout the trial. The study was a randomized, double-blind, 85-day, parallel-group, eight-center study. On a 3 test days, 1, 43, and 85, mean peak responses for FEV1 and forced vital capacity and mean area under the curve were significantly higher for the iprathropium bromide-metaproterenol combination than for metaproterenol only. Duration of action was also significantly longer for the combination therapy than for the beta-agonist alone on test days 1 and 43. Neither treatment regimen produced an demonstrable effect on daily morning peak expiratory flow rates, reported respiratory symptoms, or quality of life. Both treatment regimens were similarly well tolerated with a comparable frequency of adverse events. These results suggest that the combination of iprathropium bromide and metaproterenol inhalation solutions offers a potential therapeutic advantage to patients with symptomatic COPD over nebulized metaproterenol alone without the risk of increased side effects.


Journal of Thoracic Imaging | 1992

Clinical manifestations of pulmonary fungal infections

Michael C. Boyars; Joseph B. Zwischenberger; Charles S. Cox

Coccidioidomycosis, histoplasmosis, cryptococcosis, and blastomycosis are the most common deep pulmonary fungal infections encountered by the clinician. Each has a particular environmental habitat. As world travel increases, exposure to these infections becomes increasingly more common. The article reviews the microbiology, natural history, and clinical and laboratory findings of these diseases. Treatment options for these infections also are discussed.


Digestive Diseases and Sciences | 2003

Total parenteral nutrition associated crystalline precipitates resulting in pulmonary artery occlusions and alveolar granulomas

Terry A. McNearney; Christopher Bajaj; Michael C. Boyars; John Cottingham; Abida Haque

This case report describes total parenteral nutrition (TPN) -associated crystalline precipitates occluding the pulmonary artery branches in a Crohns disease patient who survived. These precipitates caused focal vascular disruptions and alveolar granulomas. High-resolution CT (HRCT) scan demonstrated a diffuse ground-glass appearance. Pulmonary function tests showed severe ventilatory defects, arterial hypoxemia, and decreased oxygen saturations. Energy dispersive x-ray analysis (EDAX) of the patients lung biopsy and expectorant demonstrated similar patterns, supporting crystal migration into the alveoli. Treatment included broad-spectrum antibiotics, anticoagulation, corticosteroids, and daily pulmonary toilet. The patient required continuous supplemental oxygen for two months and then was able to use it intermittently. This patient survived widespread pulmonary vascular occlusions secondary to precipitation and crystallization of TPN solution, with moderately severe residual deficits in exercise tolerance and chest x-ray abnormalities. This case underscores the importance of surveillance and recognition and of TPN-associated complications by health care workers.


The Journal of Allergy and Clinical Immunology | 1990

Sensitivity of basophils to histamine releasing factor(s) of various origin: Dependency on allergic phenotype of the donor and surface-bound IgE

Rafeul Alam; Patricia A. Forsythe; John A. Rankin; Michael C. Boyars; Michael A. Lett-Brown; J. Andrew Grant

Certain species of histamine-releasing factor (HRF) have been demonstrated to distinguish a select group of allergic patients from healthy subjects. An IgE-dependent mechanism of action has been suggested. The donor and IgE dependency of HRF produced by peripheral blood mononuclear cells (PBMCs) has not been clearly demonstrated. In this study, we have compared the response of basophils from normal subjects versus allergic patients with and without asthma. In addition, we have addressed the IgE dependency of HRF recovered from cultures of PBMCs, T cells, B cells, macrophages, and bronchoalveolar lavage fluid. We have demonstrated that basophils from allergic as well as normal subjects respond to PBMC-HRF. The response of basophils from allergic patients with asthma is significantly increased. This heightened response to HRF does not correlate with the severity of disease as assessed by baseline spirometry, medication, and skin test scores. Stripping of the membrane-bound IgE by incubating basophils with lactic acid causes a significant loss of sensitivity to HRF generated by PBMCs, T cells, B cells, and macrophages, as well as to HRF recovered from bronchoalveolar fluid. The loss of response can be restored by sera from patients with asthma but not from normal subjects or by myeloma IgE. In addition, poorly responsive basophils from normal subjects can be rendered sensitive by incubating with sera from patients with asthma. The capacity of a given serum from a patient with asthma to restore the response to HRF is not correlated with the total concentration of IgE in the serum.(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of Medical Case Reports | 2011

An unusual case of metastasis to the left side of the heart: a case report

Bharadwaj Cheruvu; Praveena Cheruvu; Michael C. Boyars

IntroductionCardiac metastases are found in six to 20% of autopsies of patients with malignant neoplasm. The most common neoplasms that metastasize to the heart are malignant melanoma, lymphoma, and leukemia, but the relative numbers are greater with breast and lung cancers, reflecting the most common incidence of these cancers.Case presentationA 60-year-old Hispanic man presented to our hospital after being transferred from an outside hospital for workup and evaluation of an adrenal mass of the abdomen and pelvis, found on computed tomography. His chief complaint upon admission was altered mental status. Physical examination was unremarkable. He was alert and oriented and had a dry and non-erythematous oropharynx, and bilateral diffuse wheezing on lung examination. Computed tomography of the chest showed multiple hypodense lesions in the left ventricular myocardium, suggestive of metastases. There were also tiny sub-centimeter nodular densities in the right upper and lower lobes. Adrenal glands contained hypodense lesions, which showed characteristic adenocarcinomatous malignant cells.ConclusionCancers which have metastasized to the heart are found in six to 20% of patients with malignant neoplasms. The right side of the heart is more commonly involved in metastasis. This study is unusual in that a tumor of an unknown primary origin had metastasized to the left side of the heart.


Journal of Thoracic Imaging | 1991

Clinical manifestations of carcinoma of the lung

Michael C. Boyars

In 1991 lung cancer will account for 30% of all cancer deaths in this country, or more than 140,000 deaths. One reason for this high mortality rate is our inability to diagnose carcinoma of the lung at an early stage. Carcinoma of the lung is associated with numerous systemic effects. Because many of these are subtle in their clinical presentation, they may be overlooked until more obvious signs of malignancy are present. By this time, the tumor may be no longer amenable to surgical resection, and the chance for cure is lost. The article reviews the clinical manifestations of carcinoma of the lung that may alert the clinician to its presence and perhaps allow earlier diagnosis and prolonged survival.


Journal of Thoracic Imaging | 1990

The microbiology, chemotherapy, and surgical treatment of tuberculosis

Michael C. Boyars

Tuberculosis is a disease that has plagued humankind for centuries. The “white plague” is not only treatable and curable but also preventable. Initially, tuberculosis fell in the province of the general physician. With the advent of technologic advances in thoracic surgery, surgical management of tuberculosis was brought to the forefront. Effective bactericidal drug therapy became available by 1954 after the development of streptomycin in 1945 and isoniazid in 1952. Additional effective antituberculous drugs have relegated surgical therapy for tuberculosis to a relatively minor role.

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Akhil Bidani

University of Texas Health Science Center at Houston

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Michael B. Smith

University of Texas Medical Branch

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Bernard M. Karnath

University of Texas Medical Branch

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Gail L. Woods

University of Texas Medical Branch

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Madhavan Nampoothiri

University of Texas Medical Branch

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Vicki J. Schnadig

University of Texas Medical Branch

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J. Andrew Grant

University of Texas Medical Branch

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Michael A. Lett-Brown

University of Texas Medical Branch

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