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Biomedical subjects

K Ashutosh

Publications and source records attributed to K Ashutosh.

At least 19 recordsLinked to original sources
PubMed2000

Nitric oxide and asthma: a review.

Nitric oxide (NO) is synthesized from the amino acid arginine by enzymes called nitric oxide synthases. NO has an important physiologic role in the regulation of vascular tone, response to vascular injury, and hemostasis. It also acts as a neurotransmitter for the nonadrenergic noncholinergic nerves and has important antimicrobial, immunologic, and proinflammatory activities. The lung is rich in nitric oxide synthases, and NO is normally present in the exhaled air. Use of NO in the treatment of asthma has not withstood the test of time and is not recommended. With the advent of analyzers capable of measuring NO rapidly and reliably, however, the analysis of NO in exhaled air is being increasingly recognized as a potential noninvasive test for the evaluation of the inflammatory component of the pathology of patients with asthma. An increase in the exhaled NO has been shown to accompany eosinophilic inflammation and to correlate with other indices of inflammation in asthma. Exhaled NO increases during exacerbation and decreases with recovery in patients with asthma. As exhaled NO is not increased during bronchospasm in the absence of coexisting inflammation, it could serve to differentiate between the inflammatory and bronchospastic components in asthma, thereby guiding therapy with steroids and other anti-inflammatory medications. Levels of NO also can be increased in certain other conditions, for example, allergic rhinitis and adult respiratory distress syndrome, but these can be clinically differentiated from asthma and do not lessen the diagnostic value of exhaled NO. Measurements of exhaled NO are influenced by several physiologic and technical variables, which results in a wide variation in the levels reported from the different laboratories. Standardization of technique, a better understanding of the confounding effects of physiologic and environmental variables, and establishment of the normal range and variability of exhaled NO are needed before its measurement could gain wide acceptance as a clinically useful test. Development of less expensive NO analyzers is also an important consideration.

Adult↗
PubMed2000

Use of nitric oxide inhalation in chronic obstructive pulmonary disease.

BACKGROUND: Inhalation of nitric oxide with oxygen could be a promising treatment in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension. However, the current methods of delivery of NO are cumbersome and unsuitable for long term use. The present study was undertaken to investigate the safety and efficacy of a mixture of nitric oxide (NO) and oxygen administered via a nasal cannula for 24 hours in patients with oxygen dependent COPD. METHODS: Twenty five parts per million (ppm) of NO was administered by inhalation combined with supplemental oxygen at a flow rate of 2 l/min via a nasal cannula for 24 hours to 11 ambulatory men with stable, oxygen dependent COPD. Room air with supplemental oxygen at 2 l/min was administered in an identical manner for another 24 hours as control therapy in a randomised, double blind, crossover fashion to all patients. Pulmonary function tests, exercise tolerance, dyspnoea grade, and lung volumes were measured at baseline, 24, and 48 hours. Pulmonary artery pressure (PAP), cardiac output (CO), pulmonary vascular resistance (PVR), arterial blood gas tensions, and minute ventilation were measured at baseline, after 30 minutes and 24 hours of breathing NO and oxygen. Venous admixture ratio (Qs/Qt) and dead space ratio (Vd/Vt) were also calculated. Concentrations of nitrogen dioxide (NO(2)) and NO in the inhaled and ambient air were monitored continuously. Differences in pulmonary function, arterial blood gas tensions, pulmonary haemodynamics, exercise tolerance, and dyspnoea between oxygen and NO breathing periods were analysed for significance using paired t tests. RESULTS: A significant (p<0.05) fall was observed in PVR (183.1 (116.05) and 137.2 (108.4) dynes.s.cm(-3) before and after breathing NO for 24 hours, respectively) with NO administration without significant changes in symptoms, pulmonary function, arterial oxygen tension, or exercise tolerance. CONCLUSIONS: NO at a concentration of 25 ppm blended with oxygen can be safely administered by nasal cannula for 24 hours without significant adverse effects and lowers PVR in stable patients with COPD receiving long term oxygen therapy.

Administration, Inhalation↗
PubMed1997

Effects of theophylline on respiratory drive in patients with chronic obstructive pulmonary disease.

Effects of theophylline administration on the respiratory drive were studied in seven patients with chronic obstructive pulmonary disease (COPD). End tidal CO2 (PetCO2), minute ventilation (Ve), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), oxygen consumption (VO2), carbon dioxide output (VCO2), serum theophylline level (STL), ventilatory response (VeR), and mouth occlusion pressure response (OPR) to rise in PetCO2 on rebreathing were measured before and at 2-hour intervals after oral administration of 5 mg/kg anydrous theophylline or placebo. Mouth occlusion pressure response and VeR showed c significant increase after theophylline but not after placebo. Significant positive correlation between changes (delta) in STL and OPR (delta OPR = 0.025 + 0.8 delta STL; SEE = 1; r = 0.4; P < 0.005) and between STL and VeR (VeR = 0.82 + 0.055 STL +/- SEE = 0.7; r = 0.46; P < 0.01) and an inverse correlation between delta STL and delta PetCO2 (delta PetCO2 = 13.8 - 0.59 delta STL; SEE = 9.1; r = 0.61; P < 0.001) were noted. There was no correlation between the indices of respiratory drive and FEV1, Ve, VO2, or VCO2. It is concluded that theophylline increases respiratory drive in clinically employed doses independently of its bronchodilator or metabolic effects.

Aged↗
PubMed1997

Just say NO.

Explore the source record for details and available documents.

Breath Tests↗
PubMed1997

Clinical and personality profiles and survival in patients with COPD.

OBJECTIVE: To assess the relationship of personality and clinical characteristics with survival in patients with advanced chronic obstructive pulmonary disease (COPD). DESIGN: Prospective double-blind study. SETTING: Outpatient clinic of a teaching Veterans Affairs Hospital in central New York. PATIENT PARTICIPATION: Sixteen male patients (mean age, 62.2 +/- 2.5 years) with severe COPD INTERVENTIONS: Patients were administered Minnesota Multiphasic Personality Inventory (MMPI) test; their clinical features were recorded from hospital records at the time of admission into the study. All were followed up for 4 years after the initial assessment or until their death. MEASUREMENTS AND MAIN RESULTS: The nine survivors and seven nonsurvivors were similar in age, pulmonary function test (PFT) results, oxygenation, number of medications, or concomitant illnesses. However, the nonsurvivors had higher MMPI and clinical illness scores compared with the survivors (p < 0.01 and < 0.05, respectively). CONCLUSIONS: The 4-year mortality in male veterans with severe COPD is influenced by overall psychological distress and difficulty in coping with their disease, which seem to be important prognostic indicators irrespective of PFT results or oxygenation.

Aged↗
PubMed1997

Effects of sustained weight loss and exercise on aerobic fitness in obese women.

OBJECTIVE: To assess the long term effects of weight loss with and without additional aerobic and weight training exercises on exercise tolerance and cardiorespiratory fitness in obese women. EXPERIMENTAL DESIGN: Randomized prospective study for an approximately one-year community setting. PATIENTS: 31 healthy obese women volunteers (age 42.8 yrs +/- 6 SD) recruited by community advertisement. INTERVENTION: All subjects underwent a weight loss program consisting of low calorie diet and behavior therapy for a minimum of 46 weeks. They were randomly assigned to one of the four groups. Group A: diet alone, Group B: diet plus aerobic exercise program in a supervised group setting, Group C: Diet plus weight training and Group D: diet plus weight training plus aerobic exercise program. MEASURES: Exercise time (Tex) peak sustained workload (Wp), peak oxygen consumption (VO2), oxygen pulse and the rate of change of VO2 on recovery (VO2rec) were measured at the beginning and after 47.5 weeks +/- 1.5 SD, of the program. RESULTS: All subjects lost weight and achieved increased Tex and lowered resting VO2. VO2 peak and VO2 peak kg-1 increase in Groups B and D only. O2 pulse and VO2rec improved in group D. Improvements in exercise time correlated significantly with initial exercise time and weight loss. CONCLUSIONS: Weight loss increase Tex irrespective of participation in an exercise program. However, evidence of improved aerobic fitness occurred only in groups performing aerobic exercise.

Adult↗
PubMed1995

Nonbronchodilator effects of pirbuterol and ipratropium in chronic obstructive pulmonary disease.

BACKGROUND: Although both beta-adrenergic agonists and anticholinergic agents are widely used in the treatment of patients with COPD, they influence the pulmonary circulation and ventilation differently. We compared the effects of these two agents on gas exchange and distribution of ventilation in COPD. METHODS: Pirbuterol and ipratropium bromide were administered by inhalation via a metered-dose inhaler to 12 and 14 patients with COPD, respectively, in a randomized, double-blind fashion. Pulmonary function tests, arterial blood gas levels, heart rate, resting minute ventilation (VE), physiologic dead space volume to total ventilation ratio (VD/Vt) and oxygen consumption (VO2) were measured prior to and then 5, 15, 30, and 60 min after administration of the respective drugs. The changes in these measurements after administration of the two drugs were analyzed and compared with each other. RESULTS: The pulmonary function test measurements showed similar improvement after administration of both drugs. Heart rate fell in both groups. After administration of pirbuterol, the alveolar-arterial oxygen pressure difference (P[A-a]O2) and VE rose significantly and the rise in FEV1 showed a negative correlation with the fall in PaO2. In contrast, the use of ipratropium bromide did not produce these effects, but resulted in a fall in VO2 and a rise in VD/Vt. CONCLUSION: Pirbuterol and ipratropium are equally effective bronchodilators in COPD. Pirbuterol results in a significant rise in P(A-a)O2 and resting VE. Ipratropium does not affect these measurements and seems to reduce the oxygen cost of breathing. The results suggest significant differences between the effects of the two agents on gas exchange, ventilation, and VO2 which could be of clinical significance.

Administration, Inhalation↗
PubMed1992

Prediction criteria for successful weaning from respiratory support: statistical and connectionist analyses.

OBJECTIVE: To develop predictive criteria for successful weaning of patients from mechanical assistance to ventilation, based on simple clinical tests using discriminant analyses and neural network systems. DESIGN: Retrospective development of predictive criteria and subsequent prospective testing of the same predictive criteria. SETTING: Medical ICU of a 300-bed teaching Veterans Administration Hospital. PATIENTS: Twenty-five ventilator-dependent elderly patients with acute respiratory failure. INTERVENTIONS: Routine measurements of negative inspiratory force, tidal volume, minute ventilation, respiratory rate, vital capacity, and maximum voluntary ventilation, followed by a weaning trial. Success or failure in 21 efforts was analyzed by a linear and quadratic discriminant model and neural network formulas to develop prediction criteria. The criteria developed were tested for predictive power prospectively in nine trials in six patients. RESULTS: The statistical and neural network analyses predicted the success or failure of weaning within 90% to 100% accuracy. CONCLUSION: Use of quadratic discriminant and neural network analyses could be useful in developing accurate predictive criteria for successful weaning based on simple bedside measurements.

Aged↗
PubMed1990

Use of serum theophylline level as a guide to optimum therapy in patients with chronic obstructive lung disease.

Blood and urine samples were collected simultaneously with measurements of pulmonary function at 2-hour intervals for 8 hours after oral administration of short-acting (SAT) and long-acting theophylline (LAT) preparations in 15 patients with stable chronic obstructive lung disease (COLD) on long-term maintenance theophylline therapy. The relationship between pulmonary function tests, serum theophylline level, plasma and urinary adenosine 3'5' cyclic monophosphate (cAMP) was examined. The highest forced expiratory volume in one second FEV1 was obtained with STL of 12.8 micrograms/ml +/- 5.21 SD and 9.14 micrograms/ml +/- 6.15 (P less than .05) after administration of SAT and LAT, respectively. A further increase in serum theophylline level (STL) offered no therapeutic benefit, and, in fact, was associated with a fall in FEV1 in many instances. Plasma or urinary cAMP measurements did not correlate with STL. STL at which the best pulmonary function is achieved is quite variable in patients with COLD on maintenance theophylline therapy, is frequently less than 10 micrograms/ml, and can be determined only by repeated measurements of pulmonary function at different STL. Therefore measurements of STL are of limited value in guiding treatment with theophylline.

Aged↗
PubMed1988

Nifedipine in chronic cor pulmonale: acute and relatively long-term effects.

After 20 mg sublingual nifedipine in 12 men with clinical stable chronic cor pulmonale the mean arterial pressure and systemic vascular resistance fell, cardiac index rose, and mean pulmonary arterial (Ppa) and wedge (Ppaw) pressures, right atrial pressure, and PaO2 remained unchanged. After 20 mg orally every 6 hours for 24 hours in 11 patients, the mean arterial pressure fell further, systemic vascular resistance remained low, and the cardiac index returned to baseline, whereas the Ppa and Ppaw decreased, but the pulmonary vascular driving pressure (Ppa-Ppaw), right atrial pressure, PaO2, and spirometry and ejection fractions remained unchanged. Of eight patients receiving maintenance therapy four developed untoward side effects in 1 to 3 weeks and one was noncompliant. The remaining three patients evaluated at 6 weeks failed to improve and had unchanged resting hemodynamics. Thus in the absence of a potentially reversible hypoxic pulmonary hypertension, nifedipine may not improve pulmonary arterial pressure and cardiac function in clinically stable patients with cor pulmonale.

Administration, Sublingual↗
PubMed1987

Respiratory sensitivity to carbon dioxide in schizophrenia.

Respiratory sensitivity was evaluated in 10 patients with schizophrenia and 10 normal control subjects utilizing a rebreathing system and measurements of the changes in the mouth occlusion pressure in 100 ms and ventilation in response to the increase in end-tidal PCO2 (PetCO2). Although ventilation response was similar in both groups, we noted that the occlusion pressure response was more variable (coefficient of variability, CV = 17.5%) and the correlation coefficient (r = 0.75 +/- 0.13) lower in the patients with schizophrenia compared to controls (CV = 4.6%; r = 0.90 +/- 0.04). Apnea threshold was also lower in patients with schizophrenia (29.03 +/- 12.73 Torr, mean +/- SD) compared to controls (39.5 +/- 4.5 Torr). Furthermore, schizophrenia patients showed a significant positive and negative correlation between occlusion pressure response and age (r = 0.73; p less than 0.001) and estimated duration of schizophrenia (r = 0.65; p less than 0.05). We conclude that the apnea threshold is lower and the respiratory sensitivity to CO2 is more variable in patients with schizophrenia compared to normal subjects.

Adult↗
PubMed1987

Noninvasive tests for responsiveness of pulmonary hypertension to oxygen. Prediction of survival in patients with chronic obstructive lung disease and cor pulmonale.

Response of mean pulmonary artery pressure (PAP) to breathing oxygen for 24 hours was measured in 43 patients with chronic obstructive pulmonary disease and cor pulmonale (COPD-CP). Considering a greater than or equal to 5 mm Hg fall in PAP after breathing 28 percent oxygen for 24 hours to be a significant response to oxygen administration, 25 and 18 patients were identified as responders (R) and nonresponders (NR), respectively. Oxygen consumption at the end of a symptom-limited maximum exercise (Vo2 peak) and right (RVEF) and left ventricular (LVEF) ejection fractions by nuclide ventriculography (NVG) were also obtained, and the changes (delta) in RVEF and LVEF after 48 hours of oxygen breathing recorded. All patients were prescribed continuous long-term domiciliary oxygen therapy (CLTO) and followed up as outpatients. Thirty-three patients have completed the follow-up for three years or until their deaths. The R showed a markedly higher survival compared to the NR at 1, 2, and 3 years. A high Vo2 peak (greater than 6.5 ml min-1 kg-1) was significantly associated with R status and also predicted two- and three-year survival. A baseline EF or delta EF of right or left ventricles could not be used to predict either the response of PAP to O2 or the long-term survival, although delta LVEF was significantly higher in the R. Response of PAP to breathing O2 for 24 hours is a reliable indicator of at least three-year survival with CLTO, which can be predicted noninvasively by baseline Vo2 peak.

Exercise Test↗
PubMed1986

Comparison of the anticholinergic bronchodilator ipratropium bromide with metaproterenol in chronic obstructive pulmonary disease. A 90-day multi-center study.

The short- and long-term efficacy and safety of an inhaled quaternary ammonium anticholinergic agent, ipratropium bromide, and a beta agonist aerosol, metaproterenol, were compared in 261 nonatopic patients with chronic obstructive pulmonary disease (COPD). The study was a randomized, double-blind, 90-day, parallel-group trial. On three test days-one, 45, and 90-mean peak responses for forced expiratory volume in one second and forced vital capacity and mean area under the time-response curve were higher for ipratropium than for metaproterenol. Clinical improvement was noted in both treatment groups, especially during the first treatment month, with persistence of improvement throughout the remainder of the study. Side effects were relatively infrequent and generally mild; tremor, a complication of beta agonists, was not reported by any subject receiving ipratropium. These results support the effectiveness and safety of long-term treatment with inhaled ipratropium in COPD.

Adult↗
PubMed1984

Sarcoidlike granulomas as an early manifestation of Whipple's disease.

Whipple's disease is often accompanied by a long, preintestinal phase of vague symptoms, such as weight loss, fever, and migratory arthralgia, which may delay diagnosis and proper treatment. We report a patient who presented with sarcoidlike granulomas in the lung 1.5 yr before the development of gastrointestinal symptoms. He was treated with prednisone and his lung lesions improved dramatically. However, steroids could not be discontinued until the diagnosis of Whipple's disease was made and he was started on antibiotic treatment. Whipple's disease was diagnosed from a small intestinal biopsy specimen by electron microscopic demonstration of characteristic bacillary bodies. Liver biopsy specimens also demonstrated a few Kupffer cells containing degenerative bacillary bodies. Based on this case and other reported cases of Whipple's disease with sarcoidlike lesions in various organs, we suggest that sarcoidlike tissue reaction can be an early manifestation of Whipple's disease, recognition of which may have practical value in facilitating an early diagnosis and treatment.

Diagnosis, Differential↗
PubMed1984

Comparison between long-term treatment of chronic bronchitic airway obstruction with ipratropium bromide and metaproterenol.

Twenty-eight patients with chronic obstructive lung disease with a reversible component were treated with either 40 micrograms of ipratropium bromide (IB) or 1.5 mg of metaproterenol (MP) by a metered dose inhaler four times a day in a double-blind randomized fashion. The treatment was continued for 3 months and pulmonary function tests and clinical evaluation were made on days, 1, 30, 45, 60, and 90. IB produced significantly greater bronchodilatation between one and three hours compared with MP. Furthermore, patients receiving IB showed no decline in effectiveness over 3 months, in contrast to MP which showed some evidence of development of drug tolerance within the same period. No side effects were noted. It is concluded that the anti-cholinergic agent IB is a more effective bronchodilator at the doses used in the above group of patients, both acutely and over a long-term period.

Atropine Derivatives↗
PubMed1983

Gradual versus abrupt weaning from respiratory support in acute respiratory failure and advanced chronic obstructive lung disease.

Two methods of weaning from mechanical ventilation were compared in 18 instances of acute respiratory failure requiring mechanical ventilation for more than 30 days in patients with advanced chronic obstructive lung disease. All patients were ventilated using intermittent mandatory ventilation. Abrupt weaning (AW) consisted of abruptly discontinuing mechanical ventilation when the patients were considered ready for unassisted breathing. Gradual weaning (GW) involved a gradual reduction in the rate of intermittent mandatory ventilation before starting unassisted breathing. Gradual or abrupt weaning alone was used for weaning in five and four instances, respectively. Both methods were used in nine other instances. In the 14 instances when GW was tried, weaning was successful in three. In the 13 instances when AW was tried, weaning was successful in nine. The time in which mechanical ventilation was required was 64 +/- 31 (SD) days with GW and 42 +/- 12 (SD) days with AW. There was no difference in age, pulmonary function, or arterial blood gas results between the patients being weaned by the different methods. I conclude that GW offers no advantage over AW in weaning patients with advanced chronic obstructive lung disease requiring prolonged mechanical ventilation.

Acute Disease↗