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Biomedical subjects

D P Mukherjee

Publications and source records attributed to D P Mukherjee.

At least 19 recordsLinked to original sources
PubMed1997

Biomechanical evaluation of new fixation devices for mandibular angle fractures.

This biomechanical study investigated the effectiveness of fixation devices of simulated angle fractures in sheep mandibles. The fractures were stabilized by a Leibinger 8-hole three-dimensional (3-D) plate, a Synthes eight-hole mesh plate, and a Synthes six-hole reconstruction plate with 2.0-mm and 2.4-mm mono- and bicortical screws. Each mandible was tested in bending (class III cantilever model). The bone mineral density of the mandibles was measured by computed tomography scan. The Leibinger 3-D plate showed plate deformation in bending of > 230 N. None of the plates showed failure in the bone/screw interface. The gap and displacement values for the mesh and 3-D plate were comparable to those of the reconstruction plate. These results indicate that a 3-D or mesh plate can be used for fixation of mandibular angle fractures.

Animals↗
PubMed1995

Anterior screw fixation of type II odontoid fractures. A biomechanical study.

STUDY DESIGN: This study examined the torsional and shear stiffness of Type II odontoid fractures that were stabilized with two 3.5-mm cannulated AO screws or a single 4.5-mm cannulated Herbert screw. OBJECTIVE: To determine the stability of a commonly used two-screw method versus a single-screw fixation method. Insertion of a single screw could make the procedure technically easier. SUMMARY OF BACKGROUND DATA: Biomechanical studies have shown the 4.5-mm Herbert screw to generate greater compressive forces than 3.5-mm cannulated screws, which are commonly used to anteriorly stabilize Type II odontoid fractures. No previous biomechanical studies have compared the shear or torsional stiffness of Type II odontoid fractures stabilized with these screws. METHODS: Twelve cadaver C2 vertebrae were harvested and an osteotomy was performed to simulate a Type II fracture pattern. Six were stabilized with two 3.5-mm cannulated screws, and the remaining were stabilized with a single 4.5-mm cannulated Herbert screw. Each specimen then was tested in torsion through +/- 0.75 degrees, +/- 1.25 degrees, and +/- 1.75 degrees for 10 cycles each. Shear forces then were applied from an anterior to posterior direction to a maximum load of 44.48 N. RESULTS: The mean torsional stiffness for the Herbert screw was 1196 N.m/deg, which was significantly greater than the mean stiffness of the 3.5-mm screw fixation, which measured 434 N.m/deg. The mean shear stiffness for the Herbert screw fixation was 106.9 kN/m, compared to 86.1 kN/m for the 3.5-mm cannulated screw. This was not statistically significant. CONCLUSIONS: The biomechanical properties of the 4.5-mm cannulated Herbert screw suggest it may lend itself for use in fixation of Type II odontoid fractures. With only a single screw to insert, this technically demanding procedure may be less daunting.

Aged↗
PubMed1995

Bacterial colony counting using distance transform.

A distance-transform based technique is presented for the segmentation of monochrome images of colonies grown on membrane filters. This is used to count the number of Escherichia coli in a given water sample, which is used as a parameter for determining water quality. The result is compared with fuzzy c-means clustering approach.

Algorithms↗
PubMed1993

Myotrophin induces early response genes and enhances cardiac gene expression.

We have identified and partially sequenced a soluble factor, myotrophin, from spontaneously hypertensive rat hearts and hypertrophic human hearts that enhances myocyte protein synthesis and stimulates myocardial cell growth. Our studies suggest that myotrophin may be a biochemical link between hemodynamic stress and myocardial cellular hypertrophy. When rat neonatal cardiac myocytes maintained in culture were incubated with myotrophin for 30 minutes, they showed a marked increase in c-myc, c-fos, and c-jun messenger RNA levels. Cardiac myocytes treated for 24 hours with myotrophin showed a fourfold increase in connexin 43 (gap junction protein), a sixfold increase in atrial natriuretic factor, a threefold increase in skeletal alpha-actin, and a threefold increase in total myosin transcript levels. Studies on myosin isoforms showed a selective increase in the beta-myosin heavy chain transcript levels but no reciprocal decrease in alpha-myosin heavy chain transcript levels. Our data suggested that myotrophin appears to be a primary modulator for myocardial cell growth and differentiation and may play an important role in the pathogenesis of cardiac hypertrophy. Myotrophin may be involved in the upregulation of myofibrillar protein and the activation of cardiac gene transcription during growth and hypertrophy of the myocardium, and the induction of early response gene expression may be linked to this response.

Actins↗
PubMed1987

Biological affinities between the migrant groups of fishermen of Puri Coast, Orissa, India.

Biological affinities between the three endogamous groups of marine fishermen of Puri are examined with the help of nine anthropometric measurements and 22 dermatoglyphic traits of fingers and palms. The results are interpreted in the light of their ethnic, geographical, and migrational backgrounds. Multiple discriminant analysis and Mahalanobis's generalized distances suggest higher discrimination of populations with reference to anthropometric traits as compared to that in dermatoglyphic variables. While the nature of interpopulation distances conforms to the geographic pattern in anthropometrics, no clear picture emerges in the dermatoglyphic distances supporting either ethnic or geographic evidence.

Adult↗
PubMed1985

A new synthetic monofilament absorbable suture made from polytrimethylene carbonate.

The physical and biologic characteristics of a new synthetic absorbable monofilament suture, glycolide trimethylene carbonate (GTMC) are presented. The suture was formulated to combine predictable in vivo performance of synthetic absorbable sutures with the handling characteristics of a monofilament suture. Three in vivo studies were described: strength, gross and microscopic absorption and reaction, and radiolabelled decay. The studies carried out in rats showed cumulative strength retention of sizes 0, 00, 4-0 and 5-0 of 81 per cent at 14 days, 59 per cent at 28 days and 30 per cent at 42 days. Strength retention was consistent throughout the size spectrum. Absorption of sizes 00 and 4-0 were studied in subcutaneous implantations in rabbits. Histologic assessment of absorption obtained from serial sections at intervals of three to nine months showed that, in both sizes, complete absorption occurred between six and seven months. At six months, 83 per cent of size 00 was absorbed and size 4-0 was 93 per cent absorbed. At seven months, no implanted material was discernible histologically. Untoward tissue reactions, such as acute inflammatory cells, abscesses or tissue necrosis, were not observed. There were no signs of cellular mobilization of any kind observed remote from the implant. Absorption of GTMC sutures was achieved through the action of mononuclear and multinuclear macrophages which were confined to the implant and sequestered by a fibrous connective tissue capsule. When implant absorption was complete, resorbtion of the macrophage component was observed which was replaced by a narrow cord of fibrous tissue and collagen. The results of studies of radiolabelled sutures carried out in the subcutaneous tissues of rats revealed urine and expired CO2 to be the major excretary routes of the metabolites. By 22 to 24 weeks, 0.1 to 0.7 per cent of the total implanted radioactivity remained at the suture sites. Tissue deposition and excretion of radioactivity suggests similar metabolism of the sutures in both species. We conclude that GTMC sutures maintain good strength with little or no absorption during the critical wound healing period, absorbs completely from tissues in six to seven months with minimal tissue reaction and, therefore, provides an absorbable, flexible, monofilament material with extended support that is strong and effective.

Absorption↗
PubMed1983

Low haemoglobin levels in A1 and O blood groups.

In an anthropological investigation of 114 Bengalee families of the Sodepur industrial suburb of Calcutta, the average haemoglobin level is found to be significantly lower in males with A1 blood group than those with other blood groups, and this is more marked in young age. A depression of the haemoglobin level is also apparent in women of reproductive age who have blood group O, conforming to the suggestion of greater bleeding tendencies in individuals with O blood group than in others.

ABO Blood-Group System↗
PubMed1980

A proposed formulation of palmar patterns with special reference to Jatavs and other Indian populations.

Frequencies of patterns with triradii, that is, whorls, loops, and tented arches have been studied on palms of 58 males and 70 females of the Jatav population of Western U. P., India. It is demonstrated that simple presentation of pattern combinations on two hands permits evaluation of pattern frequencies simultaneously in individuals and on hands; derivation of average pattern value or number of loops per area, and computation of pattern intensity index for palms, which is related but not equal to the number of triradii. The bimanual, sexual and area-specific trends and their interrelations have been further elucidated by applying this method. The convention of recording frequencies of patterns and vestiges per hand lacks efficiency for clinical, genetical or anthropological analyses and overestimates sex difference. The present data have been broadly compared with published Indian material, eliminating subjective classes as far as practicable.

Dermatoglyphics↗
PubMed1978

ABO blood groups and ABH saliva secretion in Reddis and Kammas of Southern Andhra Pradesh.

ABO blood groups and ABH saliva secretion were investigated in two caste populations, Reddis and Kammas of Southern Andhra Pradesh, and compared with the data of other populations. In ABO gene frequencies, the present series of Reddis and Kammas approach the values from other Andhra caste data. Moderate gene frequency of non-secretor gene in both Reddis and Kammas are noted.

ABO Blood-Group System↗
PubMed1977

Dynamic mechanical properties of atherosclerotic aorta. A correlation between the cholesterol ester content and the viscoelastic properties of atherosclerotic aorta.

The effect of cholesterol and cholesterol ester content of aortas on the dynamic mechanical properties of these tissues was studied in rabbits during development of atherosclerosis. The disease was induced by feeding a 1.5% cholesterol diet for six weeks. At two week intervals, an equal number of control and experimental animals were sacrificed and their aortas were collected. After grading the aortas for lesions, one-half of each aorta was used for the determination of cholesterol and cholesterol ester content while the other half was used for the determination of viscoelastic properties. The viscoelastic properties were determined in both the longitudinal and the tangentail direction of the aortas. The results showed that cholesterol feeding had no effect on the longitudinal dynamic Young's modulus of the aortas. On the other hand, the tangential dynamic Young's modulus of the aortas was found to be very much influenced by the cholesterol diet. After the first two weeks of cholesterol feeding, the tangential dynamic Young's modulus was found to be increased markedly with time. At the end of the 6-week period, the average value of the tangential Young's moduli was 4.0 X 10(6) dynes/cm2 in the cholesterol-fed group while in the control group it remained 2.7 X 10(6) dynes/cm2. This increase in the tangential Young's moduli showed a remarkable correlation with the increase in the cholesterol ester content of the aortas. The cholesterol est content of aortas, like the tangential Young's modulus, remained unaffected during the first two weeks of cholesterol feeding. But after the first two weeks, a rapid increase in the cholesterol ester content was observed which coincided with an almost identical increase in the tangential Young's modulus values. It is concluded that during the early stages of atherosclerosis, the cholesterol ester content of aortas exerts a significant influence on the tangential dynamic Young's modulus of aortas. The serum levels of cholesterol and cholesterol ester, although increased steadily with the cholesterol feeding, did not show any direct correlation with the viscoelastic properties of the aortas.

Animals↗
PubMed1976

Inbreeding among some Brahman populations of Tamil Nadu.

A statewide survey of four endogamous Brahman populations of Tamil Nadu reveals a low level of inbreeding in three of them. In the fourth population, the Thengalai, the level is higher, but not as high as in other social castes. The Tamil Brahmans rank next to the Telugu and the Kanarese Brahmans in this respect. Uncle-niece marriages also occur as in Telugu-speaking populations, and these exceed in the two Ayyangar populations in comparison to the Ayyar. A decline of first-cousin marriages and an increase of uncle-niece marriages are detected in the first two living generations in each population.

Consanguinity↗
PubMed1976

Effect of hydrophobic elastin ligands on the stress-strain properties of elastin fibers.

Alkyl sodium sulfates as well as sodium oleate previously shown to bind to insoluble elastin markedly decrease the tensile strength of fibers of ligament elastin. This effect correlates with the increasing number of carbon atoms in the detergent molecules. These data support previously proposed models which emphasize the importance of hydrophobic bonding to the elastic properties of this connective tissue protein.

Animals↗
PubMed1975

Genetic distances among the Ho tribe and other groups of Central Indians.

The Ho, a settled tribal group of Chota Nagpur, India, were tested for five genetic characters. Genetic distance among eleven tribal groups of Bihar, Orissa and Madhya Pradesh are calculated according to Edwards ('71). Affinities of these tribes are discussed taking into consideration the languages spoken by them. These breeding groups may have drifted apart along the paths of their dialect differentiations. Cultural and geographical factors further enhanced their isolation.

Blood Group Antigens↗