Biomedical subjects

B Mahanta

Publications and source records attributed to B Mahanta.

9 recordsLinked to original sources

PubMed2001

Transmission of bancroftian filariasis in tea agro-ecosystem of Assam, India.

Tea industry is a labor intensive agro-industry and filariasis is mostly localized among the tea garden workers in Assam. The workers live inside the gardens in colonies. Studies conducted in two cosecutive years revealed that among the host seeking Culex quinquefasciatus average infection rate was 4.6% and with 2.1 larvae per mosquito. The overall prevalence of infective mosquitos was 0.8% with average L3 load of 2.0 per mosquito. The probability of infected mosquitos surviving to have complete development of filarial larvae (13 days) was 0.17. The expectation of infective life was 1.416 days for man biting Cx. quinquefasciatus and the estimated adult survival rate of was 87.6%. It has been estimated that a total of 22,569 mosquito bites were received/man/year in tea garden environment out of which 182 bites/man/year were infective (0.806%). The monthly biting rate varied from 310-4,758.5 bites per man (mean 1,846 +/- 1,389.7 SD). Monthly transmission index of W. bancrofti filaria showed two periods of transmission. In both the year no infection was detected during February and March and infection rate remained low up to May (average infection in April 0.72% and in May 0.48%).

Agricultural Workers' Diseases↗

PubMed1999

Temporal variations in biting density and rhythm of Culex quinquefasciatus in tea agro-ecosystem of Assam, India.

Temporal changes in the biting density and host-seeking periodicity of Culex quinquefasciatus, the vector of bancroftian filariasis, were studied for two years in the tea agro-ecosystem of Assam, India. Average biting density of the vector varied from 0.8/hour in December to 13.3/hour in March. Minimum temperature was found to have a limiting effect on the biting density of the vector mosquitos. Multiple regression analysis showed that the rainfall and minimum temperature were significant factors influencing biting density of this vector mosquito. The biting rhythm of Cx. quinquefasciatus was found to be nocturnal with two distinct peak periods of biting activity. The first peak was around 19.00 to 20.00 hours and the second peak period was around 22.00 to 23.00 hours. Biting activity however was seen throughout the night with declining trend as the night proceeded.

Agriculture↗

PubMed1990

Observer reliability in CT and MRI of the abdomen/pelvis.

The purpose of this research was to evaluate two sources of error in the performance of computerized tomography (CT) and magnetic resonance imaging (MRI) of the abdomen/pelvis. The sources of error assessed were inter- and intra-observer reliability. Thirty abdomen/pelvis CT scans were randomly selected from each of three hospitals (university, VA, military) with different CT scanners. Two radiologists were recruited from each site to be CT observers. Forty-five abdomen/pelvis MRI scans were randomly selected from two institutions with different MRI scanners. Four observers were recruited to read the MRI scans. All scans were read blind without clinical information or patient identification. Overall inter-observer and intra-observer diagnostic agreement was significantly higher for MRI compared to CT. Inter-observer diagnostic agreement rates were also significantly higher for MRI when the etiologies of neoplastic vascular and metabolic/toxic were assigned. Observer experience in CT (range: 5-9 yr) or MRI (range: 2-4 yr) was not statistically associated with improved diagnostic agreement. This research addresses many of the criticisms of the MRI literature and compares MRI favorably to CT.

Abdomen↗

PubMed1989

Innocuous gas collections in pancreatic allografts demonstrated by computed tomography.

Over a 4-year period, 6 pancreatic abscesses were found in 37 patients who had combined renal and segmental pancreatic transplants. An additional 4 patients who were nontoxic at the time of their computed tomographic (CT) examinations had innocuous gas collections, either in the pancreatic allograft or the surrounding peripancreatic tissue. The possible etiology of this gas formation is discussed. These collections do not have the same ominous clinical significance as would be expected in abscess formation. Radiological evaluation should include examination of the gastrointestinal tract and voiding cystograms to detect fistula formation. Simultaneous percutaneous aspiration of this area should be performed to rule out an infective process. If this is negative in a nontoxic transplant patient, the radiologist will be in a position to obviate unnecessary surgical intervention.

Adult↗

PubMed1989

Pancreatic transplant rejection: assessment with duplex US.

The value of duplex ultrasonography (US) in the assessment of pancreatic transplants was studied in 22 patients over a 1 1/2-year period. Ninety-eight duplex US examinations were performed, and the Doppler arterial resistive indexes (RIs) correlated with clinical events after transplantation. The RI was 0.70 or less in the parenchymal vessels in all instances of normal transplant function and greater than 0.70 in seven of eight clinical episodes of rejection (87.5%). In all studies performed during these eight cases of rejection, the positive predictive value of an RI exceeding 0.70 was 100%. The negative predictive value of an RI of less than 0.70 in excluding rejection was 90%. High RI values were not found in isolated episodes of cyclosporine toxicity, pancreatitis, peripancreatic hemorrhage, or infection. Duplex US may prove to be more accurate in the diagnosis of rejection of pancreatic transplants versus renal transplants because the former cases have fewer causes of increased vascular impedance and diminished perfusion.

Female↗

PubMed1988

Neutropenic colitis: evaluation with computed tomography.

The computed tomography findings of 10 patients with neutropenic colitis are described and illustrated. Seven of these patients had leukemia, one had lymphocytic lymphoma, and two had systemic lupus erythematosus. All patients had colon wall thickening which was either isodense with the normal bowel tissue or showed areas of intramural low density. Air in the thickened bowel wall was seen in six patients. These computed tomography findings in neutropenic patients with fever, abdominal pain, and diarrhea should suggest the diagnosis in most instances, resulting in prompt treatment of this usually life-threatening entity.

Adult↗

PubMed1988

Pancreatic transplantation: scintigraphy, US, and CT.

Twenty-one patients with insulin-dependent diabetes mellitus received simultaneous renal and segmental pancreatic transplants. A retrospective analysis of 112 real-time ultrasound (US) images, 108 technetium-99m glucoheptonate scinti-scans, 55 computed tomography (CT) scans, and 11 cystograms was performed. Complications that were observed included pancreatic transplant rejection, pancreatitis, arteriovenous occlusions, hemorrhage, abscesses, and extravasation at the pancreaticocystostomy site. Scintigraphy is a sensitive indicator of normal transplant function but is non-specific when findings are abnormal. Real-time US aids in the differentiation of acute rejection from pancreatitis and arteriovenous occlusion. CT is helpful for evaluation of postoperative complications. Imaging may play an important role in the noninvasive management of pancreatic transplants.

Adult↗

PubMed1986

Dose-response relationship to dacarbazine demonstrated in a patient with malignant melanoma.

Dacarbazine has shown the most consistent activity of any single chemotherapeutic agent in patients with metastatic melanoma. While the overall rate is 21%, responses fall to less than 10% when hepatic metastases are present. We report a patient with malignant melanoma metastatic to the liver in whom an apparent dose-response relationship to dacarbazine was demonstrated. His liver metastases responded to hepatic artery infusion, progressed with systemic iv therapy, and responded upon reinstitution of hepatic artery infusion.

Dacarbazine↗

PubMedDate not supplied

Diagnostic accuracy of a teleradiology image transmission system.

Teleradiology is the remote interpretation of digitized radiographic images by physicians. The images are usually transmitted over telephone lines, but satellite communication has also been used. The interpretability of the transmitted image is an important factor in the operation and use of teleradiology systems. Commercially available equipment has certain built-in functions that may enhance the interpretability of the image received. These functions and their usefulness in diagnosis are described. It is also possible to enhance the image for transmission, prior to digitizing, by certain manual techniques. These may be of value in situations where the first transmission is lacking in some quality. A test of these functions and techniques is reported.

Diagnostic Imaging↗