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Biomedical subjects

K Sarkar

Publications and source records attributed to K Sarkar.

At least 37 records · Page 2Linked to original sources
PubMed1996

Structural and functional changes in the canine shoulder after cessation of immobilization.

The functional and structural consequences of remobilization of the glenohumeral joint after 12 weeks of immobilization were studied in 10 beagle dogs. The dogs were grouped in pairs: 2 were used as controls, and in 8 others 1 forelimb was immobilized. At the end of 12 weeks, 2 dogs in the experimental group were euthanized, as were the 2 dogs used as controls. The cast was removed from the other 6 dogs, and the remobilized animals were euthanized in pairs at the end of 4, 8, and 12 weeks. It was found that after 12 weeks of immobilization, the passive range of motion was markedly impaired, intraarticular pressure was raised during movements, and the filling volume of the joint cavity was reduced. Histologically, the capsule showed synovial lining hyperplasia and vascular proliferation in the wall. Immunohistochemical labeling for collagen Types I and III failed to show an increase of fibrous collagens in the capsular wall. Both the functional and structural changes were unaltered after 4 weeks of remobilization, but after 8 weeks they began to reverse, and they returned to normal levels after 12 weeks. Both functional and structural changes after 12 weeks of immobilization of the uninjured glenohumeral joint are reversible by remobilization. The collagen composition of the capsule seems unrelated to the degree of capsular contraction that occurs during 12 weeks of immobilization and subsequent remobilization.

Animals↗
PubMed1995

[Anatomy and pathology of the rotator cuff].

In this contribution we stress the fact that not all rotator cuff tendinopathies are degenerative in nature. Moreover, we insist on a clear distinction between intrinsic and extrinsic tendinopathies. In a final note we point out that the impingement syndrome is not always due to a developmental or acquired spur of the anterior part of the acromion.

Collagen Diseases↗
PubMed1994

Epidemic of herpes zoster following HIV epidemic in Manipur, India.

Since 1989, injecting drug use (IDU) related HIV infection has affected thousands of young adults in Manipur, a north eastern state of India bordering Myanmar following a similar kind of epidemic in adjoining countries like Thailand and Myanmar. During a clinical surveillance of a group of HIV positive IDUs for a natural history study at Manipur, herpes zoster (HZ) emerged as the most specific early HIV related illness (positive predictive value of 100%) in patients belonging to the age group of 12-45 years. Data collected from the dermatology departments of the two main hospitals of the state revealed that there had been an epidemic of HZ since 1990 (rate of 1990 being 11.3/1000 compared to 6.5/1000 in 1989, P value < 0.0001) among males of 12-45 years. The epidemic of HZ has been attributed to the preceding epidemic of IDU related HIV in the same age and gender group occurring 1 year earlier. HZ should be recognised as a marker condition similar to tuberculosis indicating the necessity of screening for HIV in regions where the dual problem of IDU and HIV exist in young adults.

AIDS-Related Opportunistic Infections↗
PubMed1994

The collagen types in the attachment zone of rotator cuff tendons in the elderly: an immunohistochemical study.

OBJECTIVE: The attachment zone of the rotator cuff tendons in the elderly was studied immunohistochemically in order to determine how degenerative changes affected the pattern of collagen fiber distribution. METHODS: Twenty-seven cuffs with their bony insertion were obtained from 22 postmortem cases of both sexes ranging in age from 52 to 90 years and without a history of shoulder ailments. In addition, 3 cuff specimens from cadavers in the 3rd and 4th decades were examined for comparison. Sections of formalin fixed tissues were stained by peroxidase antiperoxidase (PAP) technique using monoclonal antibodies against types I, II and III collagen. RESULTS: Degenerative changes affecting the fibrocartilage primarily were characterized by calcification, fibrovascular proliferation and microtears. In addition, they were found in all the cuff tendons of elderly individuals but not in those from younger subjects. Immunohistochemically, the attachment zone in areas without degenerative lesions showed collagen type I labelling strongly in bone but only moderately in the fibrocartilage. The predominant labelling in the fibrocartilage was for collagen type II, and collagen type III labelled principally in perichondrocytic areas. The tide-mark showed inconsistent labelling for any of the collagen types. In the presence of degenerative lesions, the disposition of fiber types was interrupted by calcification and microtears. Collagen type II composition of the fibrocartilage was markedly altered by the presence of fibrovascular tissue which labelled only for collagen type III. CONCLUSION: We conclude that severe degenerative changes in the cuff tendons of elderly individuals, alter the collagen characteristic of the rotator cuff and that the changes could be associated with impairment of biomechanical properties of the attachment zone, and may give rise to the clinical syndrome of enthesopathy.

Aged↗
PubMed1994

Aortic rupture and false aneurysm formation following balloon angioplasty of coarctation in an adult: successful treatment by urgent surgery.

A 25-year-old man developed a false aneurysm as a result of acute disruption of the aortic wall immediately after successful balloon dilatation of his coarctation. He underwent emergency resection of the false aneurysm and end-to-end anastomosis of the descending aorta with an excellent result. The diagnosis and management of this complication are discussed.

Adult↗
PubMed1994

Immunohistochemical distribution of type I, II and III collagens in the rabbit supraspinatus tendon insertion.

The collagen fibres in the area of attachment of the supraspinatus tendon to bone were studied immunohistochemically in 12 mature female New Zealand white rabbits. The labelling of type I collagen was uniformly prominent in the bone as well as in the fascicles of the tendon proper but inconspicuously scattered in the unmineralised and mineralised zones of the fibrocartilage. Type II collagen, not detected in the tendon proper, was widespread in both zones of the fibrocartilage. Type III collagen, on the other hand, appeared to be confined mainly to the zone of unmineralised fibrocartilage, in addition to its presence in the endotenon of the tendon proper. The region of the tidemark failed to show immunostaining for any of the collagen fibre types. In conclusion, this study demonstrates that, although all the principal fibrous collagen types are constituents of the supraspinatus tendon at its attachment site, the distribution pattern of immunolabelling varies from zone to zone.

Animals↗
PubMed1994

Effects of immobilization on the capsule of the canine glenohumeral joint. A structural functional study.

The effects of immobilization on the function of the glenohumeral joint and its capsule were investigated in eight beagle dogs. One foreleg of each animal was immobilized in a spica cast, and the dogs were euthanized after 4, 8, 12, and 16 weeks of immobilization in groups of two. The contralateral limb and the forelegs of two normal beagles were used as controls. At the time of euthanasia, the range of motion, intraarticular filling volume during passive movements of the joint, and intraarticular filling volume to rupture the capsule were measured. The synovium, including the capsule and the subscapular bursa, were examined histologically. In the immobilized limb, there was progressive restriction in the range of motion with increases in intraarticular pressure, and the filling volume that was required to cause a rupture of the capsule diminished. Morphologically, the capsule and the subscapular bursa showed focal adhesions. Thus, it appeared that immobilization of these canine forelimbs produced changes in the glenohumeral joint that resembled those of frozen shoulder in humans.

Animals↗
PubMed1993

Macrophage-directed delivery of doxorubicin conjugated to neoglycoprotein using leishmaniasis as the model disease.

The antileishmanial potency of doxorubicin conjugated to mannose-human serum albumin (man-HSA) was tested in experimental visceral leishmaniasis. Conjugation of doxorubicin did not decrease the affinity of the neoglycoprotein for the macrophage mannose receptor. Conjugated doxorubicin eliminated intracellular amastigotes of Leishmania donovani in peritoneal macrophages almost 12.5 times more efficiently than did the free drug and greatly reduced and possibly eliminated splenic intracellular parasites in four consecutive dosages at 5 micrograms/kg/day for 45 days. Free drug at a similar dose had little effect. The leishmanicidal effect of doxorubicin conjugate can be prevented by competitive inhibitors such as man-HSA or mannan and inhibitors of receptor-mediated endocytosis such as colchicine and monensin. These results not only indicate the potential of doxorubicin as an effective chemotherapeutic agent for leishmaniasis but also establish the use of mannosylated neoglycoprotein as a drug carrier in the therapy of macrophage-associated diseases.

Animals↗
PubMed1993

Rapid spread of HIV among injecting drug users in north-eastern states of India.

Manipur, a north-eastern state of India bordering Myanmar, has experienced very rapid transmission of the human immunodeficiency virus (HIV) among its vast drug-injecting population. Seroprevalence among intravenous drug users increased from 0 per cent in September 1989 to 50 per cent within six months. With a minimum injecting population of 15,000 and seropositivity of over 50 per cent, the infection quickly spread to the population at large. One per cent of antenatal mothers tested seropositive by 1991. Forming part of the area of South-East Asia known as the Golden Triangle, and producing opium and its derivatives, Myanmar shares a long international border with four States of the region, and populations with a common language and culture move freely across borders. Two other north-eastern states of India bordering Myanmar have faced a similar epidemic within a short period of time. As a result of serosurveillance for HIV since 1986, the epidemic could be detected at an early stage. The present paper provides an account of the results of ongoing comprehensive studies conducted in the north-eastern states of India on drug-related HIV infection, already a serious problem, but possibly still restricted to that region of the country. The prevalence of intravenous drug users, their HIV serological status, the demographic profile, risk behaviour, the spread of the infection to other groups and the problems of harm minimization are also covered.

Adolescent↗
PubMed1992

Periarticular soft tissue conditions causing pain in the shoulder.

Pain originating in periarticular soft tissues of the shoulder is a common clinical problem among the aged patients of both sexes, but it has become increasingly frequent in young individuals because of a health-oriented life style. In the past year, a considerable progress has been made in diagnosing these conditions, especially with the aid of magnetic resonance imaging. Our understanding of the pathogenesis of these conditions, however, has advanced very little, and we hope that more efforts will be devoted in the future to elucidate how the periarticular soft tissues of the shoulder react to diverse injuries they are exposed to.

Humans↗
PubMed1991

Usefulness of a new technique for hind limb immobilization in rats for the study of tendon healing.

To study wound repair in rat Achilles tendon, we utilized a novel surgical method for immobilizing only one hind limb. In this technique, the femoral vessels were preserved while the skin, muscles, nerves and the shaft for the femur were transected. The limb was then rotated and sutured to lie on the posterolateral flank of the animal. The recovery was prompt and the procedure affected the routine growth and metabolism of the animal minimally throughout the period of experimentation. In the immobilized limb, healing of the Achilles tendon was studied after subtotal severance in the midsection. The rats were killed at intervals of 1, 2, and 4 weeks postoperatively. After 1 week, the surface of the wound was covered by a thin layer of cells. A gap persisted underneath and showed fibrovascular proliferation at the margins. In 2 weeks, the gap was completely occupied by fibrovascular tissue that was beginning to align along the long axis of the tendon. By the 4th week, remodeling had occurred and the site of the wound had almost blended with the rest of the tendon. We conclude that this new technique of hind limb immobilization causes little stress on the animal, and it can be useful for the study of tendon healing.

Achilles Tendon↗
PubMed1991

Shoulder pain and reflex sympathetic dystrophy.

Shoulder pain has become one of the commonest clinical problems in modern North American society. The pathogenetic mechanisms vary widely, and often times, speculations about the underlying pathology have not been substantiated by investigative studies. In the past year, progress in our knowledge about shoulder pain has not been significant. We discuss the topic by dividing shoulder pain into four categories: 1) shoulder pain of local origin; 2) pain referred to the shoulder; 3) shoulder and neck pain; and 4) shoulder pain and reflex sympathetic dystrophy. It appears that a thorough history taking, an understanding of the psychosocial background of the patient, and a complete physical are equally important in the clinical evaluation of painful shoulders.

Humans↗
PubMed1991

Surgical repair of rotator cuff ruptures. The importance of the subacromial bursa.

We examined biopsy specimens obtained during surgery on 115 patients with complete rotator cuff rupture. The vascularised connective tissue covering the area of rupture and the proliferating cells in the fragmented tendons reflected more of the features of repair than of degeneration and necrosis. The main source of this fibrovascular tissue was the wall of the subacromial bursa. These features clearly indicated a vigorous reparative response which might play an important role in tendon reconstitution and remodelling. We therefore suggest that extensive debridement along with subtotal bursectomy, commonly practised during surgical repair of rotator cuff rupture, should be avoided. Although strong suture margins are essential for good operative results, debridement should be judicious and preserve as much as possible of the bursa and the associated fibrovascular tissue.

Acromioclavicular Joint↗
PubMed1991

Classification and definition of tendinopathies.

The authors have classified tendinopathies into two categories. The majority of the tendinopathies are in the primary category in which lesions arise in the substance of the tendon. The authors emphasize that not all tendinopathies are degenerative in nature. Some primary tendinopathies are reactive, such as calcifying tendinitis.

Athletic Injuries↗
PubMed1990

Mast cells in the rat heart during normal growth and in cardiac hypertrophy.

Mast cells in rat hearts were studied quantitatively during normal postnatal growth and in two types of cardiac hypertrophy. Normally, cardiac mast cell density in 11-12-day-old animals is very low, but increases markedly in the following 2-3 weeks to its highest values, with a subsequent decline toward adult values. At the peak of mast cell density, the percentage of mast cells in close proximity to capillaries is also highest. In adult animals, mast cell counts are significantly higher in the right ventricle than in the left. This relation is preserved even when the right ventricle is hypertrophic, as in rats born at simulated high altitude. Chronic hypertension and swimming have little effect on the mast cell density in rat hearts. Conspicuous changes in the mast cell density at the time of capillary proliferation seem to indicate a special role played by these cells in the formation of new vessels.

Altitude↗