Biomedical subjects

R K Chitkara

Publications and source records attributed to R K Chitkara.

At least 19 recordsLinked to original sources

PubMed2001

Immunoglobulin-E and anti-IgE treatment in lung disease.

A highly specific monoclonal antibody binding IgE (anti-IgE/omalizumab) has made it possible to determine the immunopathogenetic role that this reaginic antibody plays in human allergic disease. It is clear from recently completed studies that IgE is essential to the full generation of early and late asthmatic responses in human bronchoprovocation trials. Importantly, anti-IgE treatment of severe asthma disease significantly improves symptoms and reduces exacerbation episodes. Elevated serum levels of IgE are prominent in the clinical presentation of allergic bronchopulmonary mycoses and IgE-mediated Type I hypersensitivity reactions are of fundamental importance to the immunopathogenesis of allergic bronchopulmonary aspergillosis. Although the role of IgE in mediating immunity to helminth parasites is considerably less clear, it is safe to conclude that the overall balance of evidence does not support a primary role for IgE in host protection with regard to schistosomiasis and strongyloidiasis.

Antibodies, Anti-Idiotypic↗

PubMed2000

Clinical and chest radiographic findings among persons with sputum culture positive for Mycobacterium gordonae: a review of 19 cases.

STUDY OBJECTIVES: To describe the clinical and radiographic findings associated with growth of Mycobacterium gordonae in cultured sputum and to determine the proportion of cases that fulfill criteria for nontuberculous mycobacterial pulmonary disease as established by the American Thoracic Society. DESIGN: A retrospective review of charts and radiographs of all patients from whom M gordonae was isolated from sputum cultures between November 1996 and June 1998. SETTING: University-affiliated Veterans Affairs hospital. PATIENTS: Nineteen patients were identified with sputum culture positive for M gordonae. All patients had a chest radiograph within 1 month of sputum culture. RESULTS: Sixteen patients (84%) had suppressed local and/or general immunity. Sixteen patients (84%) had respiratory symptoms, weight loss, fever, or night sweats as an indication for chest radiography. Seventeen patients (89%) had abnormal chest radiographs; however, no typical radiographic pattern was observed. No patient met diagnostic criteria for nontuberculous mycobacterial pulmonary disease as delineated by the American Thoracic Society. All patients with abnormal chest radiographs and/or respiratory symptoms ultimately had alternative explanations for their pulmonary disease. CONCLUSIONS: There is a broad spectrum of chest radiographic findings among persons with sputum culture positive for M gordonae, arguing against the presence of a characteristic chest radiograph in this patient population. M gordonae is usually a nonpathogenic colonizing organism, even among persons with local or general immune suppression and abnormal chest radiograph findings.

Adult↗

PubMed2000

Benzocaine-associated methemoglobinemia following bronchoscopy in a healthy research participant.

Benzocaine (ethyl aminobenzoate) is a local anesthetic commonly used to achieve topical anesthesia of the skin and mucous membranes prior to endoscopic procedures. Methemoglobinemia, a condition in which hemoglobin cannot bind and deliver oxygen normally, has been associated with benzocaine use in various patient populations. This is the first report of benzocaine-associated methemoglobinemia occurring in a healthy research participant. The research participant developed a methemoglobin level of 27% and marked cyanosis. No adverse sequelae other than cyanosis were identified. This report extends the population in which benzocaine-associated methemoglobinemia has been described. Additionally, this report supports the observation that methemoglobin levels approaching 30% may be tolerated in otherwise healthy individuals, producing few clinically important effects. Finally, this case also indicates that, in obtaining informed consent for a procedure in which benzocaine will be administered, patients and research participants should be specifically informed of the risk of benzocaine-induced methemoglobinemia. This information is especially important in those settings in which the manufacturer-recommended dose of benzocaine may either intentionally or inadvertently be exceeded.

Administration, Topical↗

PubMed1999

Usefulness of positron emission tomography imaging in the management of lung cancer.

Positron emission tomography imaging is useful for the characterization of the solitary pulmonary nodule and mediastinal staging. Potential future applications include extrathoracic staging to help to determine the ideal site for possible tissue diagnosis, to guide treatment plans, and to monitor the response to therapy and recurrence. Positron emission tomography may also predict prognosis. This review discusses the uses of positron emission tomography, the current literature, and the clinical guidelines for positron emission tomography imaging.

Carcinoma, Non-Small-Cell Lung↗

PubMed1998

Functional magnetic stimulation for restoring cough in patients with tetraplegia.

OBJECTIVE: To evaluate the usefulness of functional magnetic stimulation (FMS) as a noninvasive method for assisting cough in patients with tetraplegia. DESIGN: A prospective before-after trial. SETTING: The functional magnetic stimulation laboratory of a spinal cord injury (SCI) service. PARTICIPANTS: Thirteen male SCI patients, with injury levels between C4 and C7. INTERVENTION: A commercially available magnetic stimulator with a round magnetic coil (MC) was used. Expiratory muscle activation was achieved by placing the MC along the lower thoracic spine. MAIN OUTCOME MEASURE: The planned major outcome measures were the maximal expired pressure (MEP), expiratory reserve volume (ERV), and forced expiratory flow rate (FEF) by FMS compared with voluntary maximal efforts. Another outcome was the optimal MC placement and stimulation intensity that would result in highest expired pressure. RESULTS: The mean (+/-SEM) MEP, ERV, and FEF generated by FMS were 66.40 +/- 6.69 cmH2O, .77 +/- .14 L, and 5.28 +/- .42 L/sec, respectively. They were 118%, 169%, and 110% of voluntary maximum efforts. MC placement at the T10 to T11 spinous process and stimulation intensity at 80% produced the highest MEP and FEF. CONCLUSION: FMS of the expiratory muscles produced significant expired pressures, volumes, and flow rates when compared with voluntary maximum efforts; therefore, FMS can be used as an effective method to restore cough in tetraplegic patients.

Abdominal Muscles↗

PubMed1998

Inspiratory flow rate and dynamic lung function in cystic fibrosis and chronic obstructive lung diseases.

STUDY OBJECTIVES: The peak inspiratory flow rates (PIFRs) generated by cystic fibrosis (CF) and COPD patients through a range of clinically relevant resistances have not yet been reported (to our knowledge). The objectives of this study were to (1) explore a relevant range of resistive loads and address whether patients with stable CF and COPD can generate the PIFR sufficient to disperse dry-powder inhalants (DPI) and (2) determine whether the optimal inspiratory flow rate effective for delivery of aerosolized pharmacologic therapeutic agents can be attained with a comfort rating acceptable to subjects. DESIGN: Prospective, controlled, subject-blinded study. SETTING: Pulmonary function laboratory at the VA Palo Alto Health Care System. PATIENTS OR PARTICIPANTS: Thirty-six subjects, including 12 healthy volunteers, 12 subjects with CF, and 12 subjects with COPD were studied. MEASUREMENTS: Studies of dynamic lung function and PIFR without and with varying resistances were obtained at a single laboratory visit. RESULTS: Dynamic lung function and PIFR varied inversely with the resistive load for all patient groups and did not correlate with the disease severity, as indicated by FEV1 of percent predicted. The average subjective comfort rating for any given resistive load was similar for subjects with CF and COPD. CONCLUSIONS: These results support the conclusion that subjects with stable CF and COPD of varying severity can comfortably generate the necessary flow rates to operate new and currently available DPIs over a wide range of inspiratory resistances.

Adolescent↗

PubMed1998

Occupational asthma. Practical points for diagnosis and management.

Asthma is a common chronic illness characterized by episodes of reversible airflow obstruction. A cornerstone of asthma management is identifying and avoiding agents that cause bronchospasm. The workplace is an important potential source of respirable exposures that can cause or trigger asthma. Identification of an occupational factor in asthma is important: early diagnosis and removal of the worker from the exposure is associated with improved prognosis; the diagnosis of occupational asthma may lead to compensation for work-related impairment and disability; and the diagnosis of occupational asthma is a Sentinel Health Event with implications for public health and prevention. In this article, we review specific causes of occupational asthma and general settings in which an occupational factor should be suspected and explored as part of the management of the worker with asthma. We also review specific and simple elements of history and pulmonary function testing that can be easily assessed by most health care practitioners and may be sufficient to establish a diagnosis of occupational asthma. Finally, we review the medical-legal implications of occupational asthma.

Airway Obstruction↗

PubMed1997

Ascariasis and hookworm.

Ascariasis and hookworm (ancylostomiasis) remain the most common intestinal nematodes in the world with significant economic, social, and medical impact. An understanding of the transmission and pathogenesis of ascariasis and hookworm are necessary to recognize their clinical manifestations and to manage the pulmonary sequelae of infection. Transmission occurs predominantly in the tropics and rural areas where there is suboptimal sanitation, personal hygiene, and education regarding these parasites. Ascariasis generally occurs through hand-to-mouth ingestion of agricultural products or food contaminated with parasite eggs. Hookworm is transmitted through larval penetration of the skin. Larval pulmonary migration generally is asymptomatic. However, symptomatic pulmonary disease may occur with fever, cough, chest pain, hemoptysis, dyspnea, and wheezing due to (1) Loffler's syndrome, (2) the effects of larval tissue migration, (3) airway reactivity or bronchospasm, (4) infectious bacterial complications from parasitic migration and associated aspiration, and rarely (5) chronic eosinophilic pneumonia, transdiaphragmatic penetration, or symptoms of upper airway obstruction. Clinical evaluation shows pulmonary opacities on chest radiograph, peripheral blood eosinophilia, and larvae in respiratory or gastric secretions. Symptomatic treatment may be necessary with bronchodilators and systemic steroids or antibiotics for bacterial complications. The drug of choice is mebendazole (Vermox) 100 mg twice a day for 3 days. Alternatives include a single dose of pyrantel pamoate (Antiminth) 11 mg/kg (maximum dose, 1 g) or albendazole (Zentel) 400 mg orally once. Invermectin (Mectizan) is available through the World Health Organization, and, in the United States, through the manufacturer on a compassionate-use basis. Ivermectin is as effective as currently available drugs against Ascaris but shows only partial efficacy against hookworms, which infest humans. Preventive measures, improvement of sanitary facilities, education, and school screening may be important in the endemic areas to control these parasitic infections.

Animals↗

PubMed1997

Dirofilaria, visceral larva migrans, and tropical pulmonary eosinophilia.

Helminthic infections are prevalent worldwide. The intestinal ascarid, Toxocara, the animal filarial parasite, Dirofilaria, and the human filarial parasite, Wuchereria or Brugia, produce an array of pulmonary disease in humans. Infections are common in temperate, tropical, and subtropical regions of the world. Pulmonary dirofilariasis is essentially an asymptomatic disease. Most cases are diagnosed accidentally after thoracotomy for a solitary pulmonary nodule presumed to be lung cancer. Clinical manifestations of toxocariasis or visceral larva migrans (VLM) are the result of allergic and inflammatory responses of the host, and manifest with airway reactivity, acute pneumonia, and persistent eosinophilia. VLM is a self-limited disease and specific treatment is rarely necessary. In acute cases, a short course of steroids reduces morbidity and mortality but preventive measures are more important in curbing toxocara infection. Tropical pulmonary eosinophilia (TPE) is the result of immunologic hyperresponsiveness to the human filarial antigen and eosinophils play a crucial role in its pathogenesis. Airway hyperreactivity, extreme eosinophilia, and pulmonary physiologic impairment are the characteristic features. Treatment of TPE with diethylcarbamazine results in dramatic amelioration of symptoms. However, low grade inflammation persists in a significant number of patients and can lead to chronic interstitial lung disease. Mass treatment of patients in certain endemic areas has been effective in eliminating TPE.

Animals↗

PubMed1996

Imaging in lung cancer.

The diagnosis, staging, and follow-up of lung cancer is a clinical and therapeutic challenge. Recent radiographic advances are critical to the management of patients with lung cancer. This review focuses on state-of-the-art chest imaging modalities, including plain radiography, computed tomography; magnetic resonance imaging, as well as the newest technique, positron-emission tomography, and discusses the current literature.

Diagnostic Imaging↗

PubMed1992

The role of surgery in treating pleuropulmonary suppurative disease--review of 77 cases managed at Queens Hospital Center between 1986 and 1989.

Despite the generally salutary experience in recent years of managing suppurative pleuropulmonary disease, empyemas and lung abscesses have persisted and increased in incidence in hospitals such as Queens Hospital Center that serve large numbers of the socioeconomically disadvantaged. This study documents the etiology, clinical presentation, treatment, and treatment results of suppurative pleuropulmonary disease at Queens Hospital Center, which serves a large segment of the urban poor, many of whom are black. Results indicate that contributory or antecedent etiologic factors include a history of prior disease (specifically pneumonia, lung abscess, obstructive lung disease, pulmonary neoplasia, and tuberculosis); a predisposition to constitutional or immunologic deficiencies (specifically, alcoholism, anemia/malnutrition, drug abuse, and acquired immunodeficiency syndrome [AIDS]); conditions contributing to tracheobronchial aspiration (specifically, alcoholism and seizure disorders); and a miscellaneous group such as prior surgery, cardiovascular disease, and sepsis syndrome. The patients in this study were young with maximal incidence occurring in the third to fifth decades of life. Patients were predominantly male (75%) and black (66%). There were 18 deaths (23%), with sepsis being the cause in 10 (56%). Most surgical interventions were conservative, ie, bronchoscopies (48), thoracenteses (43), and tube thoracotomies (39). Thirty-one open thoracotomies were performed for drainage, decortication, or pulmonary resection. The surgical mortality was three cases or 5% of the patients who underwent surgery. The designated incidence of proven AIDS in this series (29%) was low, undoubtedly because many patients refused testing, and the multiple gram-positive and gram-negative infections that were seen did not conform to the Centers for Disease Control criteria for diagnosis and case reporting for AIDS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991