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Biomedical subjects

R Dhand

Publications and source records attributed to R Dhand.

At least 73 records · Page 4Linked to original sources
PubMed1988

High speed photographic analysis of aerosols produced by metered dose inhalers.

The design of pressurized metered dose inhalers (MDI) used to assess asthma is variable. We have examined the aerosol spray flumes generated by four commercially available MDI products using high speed video photography. For this purpose a moulded jacket was designed which could hold the inhaler in an immovable position during actuation. Fresh inhalers were fitted in the jacket after thorough shaking and three successive actuations 30 s apart were filmed with a high speed video camera (200 frames s-1). The aerosol, ejected at high velocity into calm room air, was seen to have a 'jet' phase followed by a 'cloud' phase as a result of particle dispersion. Filming was continued till the flume could no longer be visualized on the TV monitor. High speed photography was used to record flumes seen on the video monitor, to enable characterization of flume appearance, dimensions and mean velocity.

Aerosols↗
PubMed1988

Use of visual analogue scales for assessment of the severity of asthma.

Use of visual analogue scales (VAS) can provide reliable assessment of dyspnea. In order to determine if VAS can be used for clinical assessment of asthma we administered the scale to 40 stable asthmatics and found a good correlation (r = -0.72) with the peak expiratory flow rate (PEFR) readings expressed as per cent of predicted normal. The scales were also used to assess severity in 12 acutely ill asthmatics. Values of VAS and PEFR were recorded at the time of admission and twice daily thereafter till discharge from the hospital. The correlation of the two parameters was less than that obtained in stable asthmatics, but graphic parallelism was remarkable.

Adolescent↗
PubMed1988

Single dose kinetics of rifampicin and isoniazid in well-nourished and malnourished patients of tuberculosis.

A single dose kinetics of isoniazid and rifampicin alone, and combination was studied in well-nourished and malnourished patients of tuberculosis. The elimination half-life of isoniazid was significantly increased when administered in combination with rifampicin in well-nourished and malnourished patients, while no significant difference was observed in any of the pharmacokinetic parameters of rifampicin in combination with isoniazid or alone in both groups of patients. Results are discussed on the basis of pharmacokinetic drug interaction.

Acetylation↗
PubMed1988

Phrenic nerve conduction in leprosy.

Phrenic nerve conduction was performed bilaterally in 22 multibacillary (BL-LL) and 18 paucibacillary (BT-TT) leprosy patients and 25 control subjects. Prolonged phrenic nerve conduction time and/or reduced amplitude of diaphragm muscle action potential beyond 2.5 standard deviations of control mean values was observed in 9 BL-LL patients (4 bilateral) and 6 BT-TT patients (all unilateral). Out of the nine BL-LL patients with phrenic nerve involvement, median motor and/or sensory nerve conduction was also abnormal in seven patients. On fluoroscopy, diaphragm movements were normal in all patients. The study documents subclinical phrenic nerve involvement in leprosy--a fact not previously recognized.

Adolescent↗
PubMed1985

A role for interstitial matrix in tissue tension of alveolar wall.

Single alveolar walls subjected to length-tension studies in saline and Bicine (0.2 M) undergo a progressive decay in tissue tension (TTD). We have examined the effect of different solutions on this TTD and looked for corresponding changes in the ultrastructure. Lung parenchyma was dissected to single alveolar walls (30 X 30 X 150 microns) in phosphate-buffered saline (0.15 M). Transferred to a length-tension bath, the tissue was immersed in Bicine, saline, fortified Hank's solution, 0.25% Alcian blue in saline, or a sodium dodecyl sulfate solution, for variable periods. Cycled through a given extension with peak force measured over time, these same tissues were fixed in buffered glutaraldehyde/tannic acid and processed for electron microscopy. Single alveolar walls immersed in saline or Bicine showed a progressive TTD. Vacuoles or spaces appeared in the interstitium which with cellular disorganization progressed with the TTD. Seen within 0.3 h, the changes were well advanced at 0.6 h. In sodium dodecyl sulfate (70 mM), however, there was no TTD and structurally there was no interstitium, with only basement membranes and fibrous proteins remaining. In fortified Hank's solution or 0.25% Alcian blue the interstitial matrix, cell morphology and tissue tension were well preserved for 1 h. This study suggest that leaching of the interstitial matrix occurs in saline or Bicine, and an intact matrix is essential for the preservation of tissue tension.

Alcian Blue↗
PubMed1985

The role of bronchial circulation in lung abscess.

We studied the anatomy of bronchial circulation in 6 sheep with multiple lung abscesses. After anesthesia, the animals were heparinized and exsanguinated. The bronchial artery, pulmonary artery, and tracheobronchial tree were filled with Batson's solution of varying colors. The cast was dissected and the anatomy was studied with a dissecting microscope as well as a scanning electron-microscope. The bronchial arteries were found to be enlarged and hypertrophied in all infected animals. The abscess cavities were surrounded with a dense vascular plexus that was being supplied exclusively by the bronchial arteries. The pulmonary capillaries were sparse and were filled entirely by the bronchial artery. The pulmonary circulation did not supply the walls of lung abscess cavity. Our findings indicate that the bronchial circulation may be more important than the pulmonary circulation in resolution and repair after certain lung infections.

Animals↗
PubMed1984

Gross and subgross anatomy of bronchial circulation in sheep.

The anatomy of the bronchial artery in sheep has recently been described. However, the course of the bronchial veins has not been well established. It has been suggested that the bronchial veins are the major site of fluid leakage following histamine infusion, and it has been postulated that the bronchial circulation may play a role in fluid reabsorption. We studied the anatomy of the bronchial circulation in 18 sheep with emphasis on bronchial venous drainage and bronchopulmonary communications. Following anesthesia animals were heparinized and exsanguinated. Evans blue dye was infused into the bronchial artery in six sheep and the gross and subgross anatomy of the bronchial circulation studied. In six other sheep the bronchial artery, pulmonary artery, and tracheobronchial tree were filled with Batson's solution of varying colors. The subgross anatomy was studied under a dissecting microscope, and samples were taken for scanning electron microscopy. In six separate sheep we studied the anatomy of the proximal vein by infusing dye directly into the vein and found that the extrapulmonary bronchial blood drained into the left azygos vein via a single vessel. Intrapulmonary bronchi are surrounded by a dense bronchial microvascular plexus which drains into the pulmonary vessels at the precapillary level.

Animals↗
PubMed1982

Bronchogenic carcinoma in Northern India.

A study of 336 patients with bronchogenic carcinoma was carried out in Chandigarh, Northern India. The findings suggest that its epidemiology differs in several respects from that in Western countries. Almost a third of all patients and 94.4% of the 54 women had never smoked. The peak frequency of bronchogenic carcinoma occurred between the ages of 51 and 60 years, 14.6% of the patients being aged less than 41 years. Of the 232 smokers and ex-smokers, 48.3% had smoked only cigarettes, 28.4% only bidis (made of naturally cured tobacco), 19.8% both cigarettes and bidis, and 3.4% hukkas. There was a clear association between duration of smoking and frequency of carcinoma. Tumours were classified in 287 (85%) of the patients. Squamous-cell carcinoma was relatively more frequent (32.4%) than any other tumour type and occurred almost exclusively in smokers. Adenocarcinoma was found in 13.2% of patients and was the most frequent tumour in non-smokers. No differences of histological type were found between cigarette smokers and bidi smokers.

Adenocarcinoma↗
PubMed1982

A comparative randomized double-blind clinical trial of isoaminile citrate and chlophedianol hydrochloride as antitussive agents.

The efficacy and safety of a new centrally acting antitussive agent, isoaminile citrate, was compared with that of chlophedianol hydrochloride in a double-blind, randomized interpatient study. A total of 66 patients participated, two and four patients were lost to follow-up with isoaminile and chlophedianol, respectively. In the experimentally induced cough in 12 normal human subjects, isoaminile (40 mg) was as effective as chlophedianol (20 mg), but its duration of action was somewhat longer. One subject developed allergic skin rash with chlophedianol and was withdrawn from the study. In 60 patients with cough associated with chest diseases, isoaminile (40 mg, 3 x daily) was as effective as chlophedianol (20 mg, 3 x daily) in suppressing cough as judged from the 3-h and 24-h cough counts. The increase in PEFR at day 7 of treatment was somewhat more marked with chlophedianol as compared with isoaminile. None of the drugs interfered with the expectoration process. The side effects observed were few, mild in nature, and did not require a decrease in dose or withdrawal of treatment in any of the patients. Isoaminile citrate was concluded to be an effective and relatively safe antitussive agent. Isoaminile citrate, alpha(isopropyl)-alpha-(beta-dimethylaminoproyl) phenylacetonitrile citrate, is a centrally acting antitussive agent. In animal experiments this drug was as efficacious as codeine but was devoid of any respiratory depressant effect [Krause 1958, Kuroda et al. 1971]. This controlled double-randomized interpatient study was designed to test the comparative efficacy and safety of isoaminile and chlophedianol, another centrally acting antitussive, in humans.

Acetonitriles↗
PubMedDate not supplied

Bronchodilator effect of terbutaline aerosol in asthmatic: comparison of two spacer devices.

The degree of bronchodilation achieved with aerosolised bronchodilators may partly depend on correct usage of a particular inhaler device. The effect of two puffs of 0.25 mg each of terbutaline aerosol using either of two spacer devices--a tube spacer and conical spacer with inhalation valve (Nebuhaler)--in a randomised manner were compared in 20 patients with bronchial asthma. All participants (11 male, 9 female) aged 16 to 50 years had clinically stable baseline airway obstruction responsive to bronchodilators. The maximum per cent increase of PEFR and FEV1 were significantly higher after inhalation via Nebuhaler than tube spacer (44.93 +/- 21.15% vs 26.67 +/- 13.17%; 74.0 +/- 17.87 vs 47.65 +/- 15.74% respectively, p less than 0.01). The increase noted at each time interval was significantly higher and more sustained with Nebuhaler. In terms of bronchodilator effect Nebuhaler had definite advantage over tube spacer in our study. There were no significant changes in pulse rate nor in blood pressure.

Administration, Inhalation↗