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Biomedical subjects

K K Mahajan

Publications and source records attributed to K K Mahajan.

At least 19 recordsLinked to original sources
PubMed1991

Effect of exercise on lung transfer factor for CO in smokers.

The lung transfer factor for carbon monoxide was studied in 24 apparently healthy smokers and in 24 well-matched non-smokers at rest and during exercise. Single-breath and steady state (TLcoss) transfer factors for carbon monoxide, the Krogh constant, and the capillary blood volume were significantly lower in smokers. Exercise increased minute ventilation to a similar extent in both groups, but significantly lower values of TLcoss were measured in smokers than in non-smokers during mild and moderate grades of exercise (p less than 0.001). This difference in TLcoss may be attributed either to the difference in capillary blood volume or to increased inhomogeneities with regard to alveolar ventilation and perfusion due to airway damages in smokers, or to both factors.

Adult↗
PubMed1991

Lung transfer components in hyperthyroidism.

Pulmonary functions were studied in twenty hyperthyroid non smoker patients. Their FVC, PEFR and MVV were significantly lowered while FEV1/FVC% and EFR25-75% were normal. Amongst the diffusion functions, Tlco, Dm and VA were reduced and VC increased, though these changes were not statistically significant. After the achievement of euthyroid state, statistically significant increase was seen in FVC, PEFR, MVV, Tlco120, Dm and VA with significant decrease in Vc from the basal levels. FEV1/FVC% and EFR25-75% were not affected. These observations suggest that the principal abnormalities in pulmonary functions in the hyperthyroid state are increased pulmonary capillary blood volume and respiratory myopathy, which are reversed as euthyroid state is achieved.

Adult↗
PubMed1991

H-reflex latency and sensory conduction in the assessment of neuropathy in patients of chronic obstructive lung disease.

H-reflex latency, proximal conduction velocity and distal proprioceptive conduction velocity were studied along with distal motor and sensory conduction in 38 patients of chronic obstructive lung disease grouped according to age and duration of the disease, as well as in 35 age-matched smoker controls and 14 non-smoker controls. The mean values of all the parameters studied in all the patient groups were significantly different from those of the non-smoker control group. Smoker controls also showed significant abnormality in all the parameters except motor conduction velocity. Among the patients, significant abnormality (mean +/- greater than 2 SD) was seen in 44.7% in motor conduction, 86.8% in sural nerve distal latency, 97% in Ia conduction velocity, 78.9% in H-reflex latency and 60.5% in proximal conduction velocity, as compared to the non-smoker control values. Among the old patients with more than 10 years of the disease, 62.5% had all the parameters significantly abnormal. More than one parameter was affected in 97.4% of the patients. The intra-group and inter-group differences in all the parameters studied, except motor conduction velocity, were statistically significant indicating that age, chronicity of the disease and smoking can produce nerve conduction defects independently and collectively. It is suggested that though all parameters studied are highly sensitive to neuropathies, proximal H-latency studies are best suited for grading conduction defects in patients of chronic obstructive lung disease, since in many patients sural nerve action potential (52.63%) and distal H-reflex response for Ia conduction studies (81.52%) could not be elicited.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Effect of salbutamol on pulmonary diffusion functions in asymptomatic smokers.

Pulmonary functions including transfer factor for CO and its components (TIco, Dm, Vc) were studied in 45 asymptomatic subjects (25 smokers, 20 non smokers) using single breath technique. Ventilatory functions of smokers were significantly reduced; these improved significantly after salbutamol inhalation but most still remained lower than in non smokers. VA and Dm were marginally higher while Vc was significantly reduced in smokers. Their TIco1(20) was influenced only insignificantly. However, after salbutamol, both Dm and Vc were significantly lowered, resulting in further reduction (p 0.01) of TIco120 in smokers. The effect of salbutamol in non smokers was insignificant.

Adult↗
PubMed1990

Autonomic reflexes in borderline hypertensives.

Autonomic reflexes were studied in 53 patients with borderline hypertension (BLH) and 25 normotensives. BLH patients had higher basal heart rate. With 2 minutes of sustained head-up passive tilt of 50 degrees or 75 degrees, the rise in heart rate was comparable in both groups but the rise in blood pressure was significantly more in the BLH group. The rise in systolic pressure with Valsalva manoeuvre as well as with sustained hand grip was significantly higher in BLH patients. The postural tachycardia index and Valsalva index were significantly lower in BLH patients probably due to higher basal heart rate.

Adult↗
PubMed1990

Effect of cold challenge on alveolar capillary blood volume in normal individuals.

The effect of immersion of both the hands and the feet in water at 10 degrees C on lung transfer factor for carbon monoxide (Tlco) and on pulmonary capillary blood volume (Vc) was investigated in 20 normal young adult males immediately, 60 min and 120 min after the end of the cold challenge. Vc was significantly reduced immediately and the reduction was aggravated at 60 min. Tlco was significantly reduced only at 60 min. All the values returned to baseline at 120 min. It is concluded that the cold-induced changes in Tlco and Vc are physiological responses and not unique to patients with Raynaud's phenomenon as suggested by some workers.

Adult↗
PubMed1990

Diurnal variations in lung transfer factor and its components.

Serial measurements of transfer factor of lung and its constituent components along with FVC and EFR25-75% were undertaken in 20 healthy nonsmoker adult males thrice on the same day. All the lung transfer components decreased as the day advanced, though reduction was statistically significant for Tlco and VA only. These changes were present in association with reduction in FVC and EFR25.75% indicating that patency of airways influences diffusion function of lung. Variations during the day are less than 7.4% and are hence unlikely to influence their diagnostic value, but serial estimation of these functions should preferably be carried out at the same time specially in the morning when these values are maximum.

Adult↗
PubMed1987

Difficulties in the serodiagnosis of infection with the fragilis group of Bacteroides.

Bacteroides antibodies were studied in sera from 74 patients infected with the fragilis group of Bacteroides and 74 healthy control persons, by immunofluorescence of 26 different serotypes of the fragilis group. Antibodies were present at titres of 10-320 in 65 (88%) patients and 50 (68%) controls (p less than 0.01). Titres of greater than or equal to 80 were demonstrated in sera of 38 (51%) patients and 5 (7%) controls (p less than 0.01). Specific IgM antibodies were detected in sera of 42 (57%) patients at a geometric mean titre (GMT) of 30, and 8 (11%) controls at a GMT of 11 (p less than 0.01). High antibody titres as well as specific IgM were found in 32 (43%) patients, while none of the controls showed such a combination (p less than 0.01). The majority of positive patients' sera (57%) reacted with five or more serotypes, whereas most positive control sera (51%) reacted against only one or two serotypes (p less than 0.01). A selected combination of serotypes not reacting with the control sera showed positive reactions with 52 (70%) patients' sera. These findings may be useful in devising schemes for the serodiagnosis of infection caused by the fragilis group of Bacteroides. However, there are indications of geographic variation in prevalence of serotypes, which may prevent the development of a single universal scheme.

Adolescent↗
PubMed1987

Development of an animal model using a closed system to study the sensitivity of a radiopharmaceutical for the detection of gastrointestinal bleeding.

An experimental animal model using a closed system to study the sensitivity of radiopharmaceuticals for the detection and localization of gastrointestinal (GI) bleeding site in a sheep was developed. This model was validated with 99mTc-DTPA. Radioactivity as low as 85.47 +/- 13.32 kBq in a volume of 2.1 +/- 0.14 ml at a bleeding rate of 0.07 ml/min was detected. Simulated intermittent bleeding experiments indicated that at 1 h after injection of 99mTc-DTPA there was still enough circulating radioactivity to bleed into the gut and that it was possible to perform repeat injection of 99mTc-DTPA as early as 2 h after the first injection.

Animals↗
PubMed1986

Evaluation of technetium-99m DTPA for localization of site of acute upper gastrointestinal bleeding.

Intravenous Tc-99m DTPA was evaluated in 34 patients with active upper gastrointestinal bleeding. Active bleeding was detected in 25 patients: nine in the stomach, 12 in the duodenum, and four from esophageal varices. No active bleeding was seen in nine patients (two gastric ulcers and seven duodenal ulcers). Results were correlated with endoscopic and/or surgical findings. All completely correlated except: 1) one case of esophageal varices in which there was disagreement on the site, 2) three cases of duodenal ulcers that were not bleeding on endoscopy but showed mild oozing on delayed images and 3) one case of gastric ulcer, in which no bleeding was detected in the Tc-99m DTPA study, but was found to be bleeding at surgery 24 hours later. The Tc-99m DTPA study is a reliable method for localization of upper gastrointestinal bleeding with an agreement ratio of 85%. This method also can be used safely for follow-up of patients with intermittent bleeding. It is less invasive than endoscopy, is easily repeatable, and has the same accuracy.

Acute Disease↗
PubMed1986

99mTc-DTPA uptake in malignant and inflammatory bowel disease: experience from gastrointestinal bleeding studies.

During the evaluation of 99Tcm-DTPA for localization of acute gastrointestinal bleeding in 81 studies (78 patients), it was observed that there was an increased 99Tcm-DTPA at sites of inflammatory and malignant lesions of the GI tract in 18 studies. Active bleeding was detected only in 10 and no bleeding was detected in the remaining eight studies. In all the increased DTPA uptake helped to localize the site of bleeding. Image subtraction of early from delayed images according to a predefined acquisition and processing protocol helped to differentiate bleeding from non bleeding lesions. We conclude that increased 99Tcm-DTPA uptake in malignant and inflammatory lesions of the bowel is an additional advantage for its use in localizing the site of acute GI bleeding. Technetium-99m diethylenetriamine pentaacetic acid (99Tcm-DTPA) has been widely used for imaging the brain and kidneys since it was introduced by Hauser in 1970. Kadir and Strauss in 1979 reported that 99Tcm-DTPA localizes in segments of bowel with inflammation due to ulcerative colitis, regional enteritis and other forms of enterocolitis. Recently we reported the advantages of 99Tcm-DTPA in localizing the site of acute gastrointestinal bleeding. Inflammatory bowel diseases are among the causes of gastrointestinal bleeding. One of the problems in localizing the site of the bleeding by radionuclide procedures is the intermittent nature of the bleeding. We have reviewed all gastrointestinal bleeding studies in our department using 99Tcm-DTPA from January 1984 till September 1985 in order to find out whether increased uptake of 99Tcm-DTPA was helpful in localizing the bleeding lesion due to malignancy and/or inflammation.

Adult↗
PubMed1986

An experimental model for the detection and localisation of gastrointestinal bleeding using 99mTc-DTPA.

99mTc-DTPA was successfully used to detect simultaneously gastrointestinal bleeding sites in experimentally created mucosal ulcers in the colon and stomach of rabbits. Unlike the other radiopharmaceuticals that are currently used, 99mTc-DTPA was rapidly cleared from the vascular, hepatic and splenic circulation. The overall background radioactivity was low. 99mTc-DTPA appears to be an ideal agent for detection and localisation of gastrointestinal bleeding sites.

Animals↗
PubMed1975

Traumatic intraperitoneal haemorrhage. Diagnosis by paracentesis and lavage.

A method is described for detecting blood in the peritoneal cavity in cases of blunt abdominal trauma. It involves introducing a peritoneal dialysis catheter through a single puncture site in the anterior abdominal wall and in some cases performing lavage. Fifty cases have been investigated by this method and the results are presented.

Abdominal Injuries↗