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Biomedical subjects

S S Yadav

Publications and source records attributed to S S Yadav.

At least 19 recordsLinked to original sources
PubMed1998

A new and simple technique of total hepatic ischemia in the mouse.

BACKGROUND: A model of total hepatic ischemia is currently not available in mice. Models described in rats using portosystemic shunts to achieve total ischemia have been notoriously difficult. In mice, the problem is compounded further when using this type of technique because of the small size of the animal. A new technique is described combining partial hepatectomy with clamping of the remnant liver. METHODS: A partial (30%) hepatectomy is performed with resection of the caudate, right lateral, and quadrate lobes, and papillary process. Vascular microclamps are placed across the pedicles of the median and left lateral lobe at the level of the hilum to achieve total ischemia. Spontaneous portocaval shunts through caudate branches and collateral vessels prevent mesenteric congestion. Animals were studied for survival. RESULTS: The procedure consistently took less than 30 min (25+/-2 min), and no bleeding of the resected tissue was observed. Evidence for total hepatic ischemia and spontaneous shunts was demonstrated by the use of an intraportal dye. All animals survived 60 min of ischemia, whereas all died after 90 min of ischemia. CONCLUSION: This is a technically simple and rapid procedure to perform. In the current environment of multiple knockout mice and bioreagents that are available, a model of this type is essential.

Animals↗
PubMed1998

Elective carotid artery stenting in the presence of contralateral occlusion.

Significant carotid stenosis in the presence of an occluded contralateral artery has a poor prognosis with medical therapy alone. Carotid cross clamping during surgical endarterectomy results in critical flow reductions in patients with inadequate collateral flow, and represents a significant risk for procedural strokes. Carotid stenting is being evaluated as an alternative to endarterectomy. We describe the immediate and late outcome of a series of 26 patients treated with carotid stenting in the presence of contralateral carotid occlusion. The mean age of the patients in this group was 65 +/- 9 years, 23 (89%) were men and 10 (39%) were symptomatic from the vessel treated. The procedural success of carotid stenting in this group of patients was 96%. The mean diameter stenosis was reduced from 76 +/- 15% to 2.8 +/- 5%. There was 1 (3.8%) minor stroke in a patient who developed air embolism during baseline angiography. At late follow-up there was no neurologic event in any patient at a mean of 16 +/- 9.5 months after the procedure. Thus, carotid stenting of lesions with contralateral occlusion can be performed successfully with a low incidence of procedural neurologic complications and late stroke.

Aged↗
PubMed1998

L-selectin and ICAM-1 mediate reperfusion injury and neutrophil adhesion in the warm ischemic mouse liver.

Leukocytes recruited during ischemia-reperfusion to the liver are important mediators of injury. However, the mechanisms of leukocyte adhesion and the role of adhesion receptors in hepatic vasculature remain elusive. L-selectin may critically contribute to injury, priming adhesion for later action of intercellular adhesion molecule-1 (ICAM-1). Paired experiments were performed using mutant mice (L-selectin -/-, ICAM-1 -/-, and L-selectin/ICAM-1 -/-) and wild-type mice (C57BL/6) to investigate leukocyte adhesion in the ischemic liver. Leukocyte adhesion and infiltration were assessed histologically. Aspartate aminotransferase levels were significantly reduced (2- to 3-fold) in mutant vs. wild-type mice in most groups but most significantly after 90 min of partial hepatic ischemia. Leukocyte adhesion was significantly reduced in all mutant mice. Areas of microcirculatory failure, visualized by intravital microscopy, were prevalent in wild-type but virtually absent in L-selectin-deficient mice. After total hepatic ischemia for 75 or 90 min, survival was better in mutant L-selectin and L-selectin/ICAM-1 mice vs. wild-type mice and ICAM-1 mutants. In conclusion, L-selectin is critical in the pathogenesis of hepatic ischemia-reperfusion injury. Poor sinusoidal perfusion due to leukocyte adhesion and clot formation is a factor of injury and appears to involve L-selectin and ICAM-1 receptors.

Animals↗
PubMed1997

Palmaz stent compression in patients following carotid artery stenting.

UNLABELLED: Carotid artery stenting is being investigated as a therapeutic strategy for the management of bifurcation stenosis. Palmaz stents were deployed successfully in the carotid arteries of 112 patients using high-pressure balloon inflations. In 11 out of 70 patients who came for 6-mo follow-up angiography, a stent collapse was noted. Carotid ultrasound was able to detect stent collapse in only two patients at follow-up. Only one patient who had collapse of stent along its entire length was symptomatic at follow-up. Repeat balloon angioplasty was performed in 5 patients, 3 of whom had a Wallstents deployed within the Palmaz stent. CONCLUSION: Stent collapse was observed in a significant number of Palmaz stents within 6 mo of placement in the carotid arteries. These observations should influence the choice of stents for the treatment of extracranial carotid disease.

Aged↗
PubMed1996

Utilization of the coronary balloon-expandable coil stent without anticoagulation or intravascular ultrasound.

BACKGROUND: The balloon-expandable coil stent has been proved effective in the management of acute and threatened closure after coronary balloon angioplasty and has been shown to reduce restenosis in patients with suboptimal results after coronary balloon angioplasty. Coronary artery stenting has been limited by the occurrence of stent thrombosis and comorbidity related to anticoagulation. This study was undertaken to determine whether anticoagulation may be removed from poststenting protocols, thus reducing comorbidity without increasing stent thrombosis. METHODS AND RESULTS: Between September 1994 and May 1995, 369 patients received balloon-expandable coil stents in native coronary arteries at our institution. Of these patients, 216 were selected for a protocol of aspirin and ticlopidine (for 1 month) without anticoagulation. Eligibility for this protocol followed satisfaction of certain procedural and angiographic criteria. These criteria included adequate coverage of intimal dissections, absence of residual filling defects, and normal (TIMI grade 3) flow in the stented vessel after high-pressure balloon inflations. Intravascular ultrasound was not used to guide stent deployment. The stenting procedure was planned in 37% of patients and unplanned in 63% of patients, including 25 (12%) for acute or threatened closure. During the 30-day follow-up period, stent thrombosis occurred in 2 patients (0.9%), there was 1 death (0.5%), and 2 patients (0.9%) underwent coronary bypass surgery. Vascular access-site complications occurred in 4 patients (1.9%), and bleeding that required blood transfusion occurred in 4 patients (1.9%). CONCLUSIONS: Patients who receive the coronary balloon-expandable coil stent with optimal angiographic results without intravascular ultrasound guidance can be managed safely with a combination of aspirin and ticlopidine without anticoagulation.

Adult↗
PubMed1993

Double oblique diaphyseal osteotomy. A new technique for lengthening deformed and short lower limbs.

We treated 25 patients with severely deformed and shortened lower limbs by double oblique diaphyseal osteotomy of the short deformed bone, followed by balanced skeletal traction to correct the alignment and increase the length of the limb. The technique is simple and inexpensive and does not require special equipment. It has the advantage of allowing rapid lengthening and secure healing as the overlap allows end-to-end union with no bone gap. The lengthening achieved ranged from 6 to 16 cm. No serious complications were encountered.

Adolescent↗
PubMed1993

Nephrolithiasis in children.

A study of 100 cases of nephrolithiasis between 3 to 15 years of age is reported. Seventy four cases were more than 10 years old. The common presenting symptoms included abdominal pain (69%), burning micturition (23%), gross hematuria (4%) and unexplained pyrexia (6%). Associated urinary tract malformations were found in 16 cases. Twenty four had struvite calculi. Urinary infection with Proteus mirabilis was found in 23 children and idiopathic hypercalciuria in 31 cases. Following surgical removal, either percutaneously or by open surgery, 8 patients had residual calculi and in 6 cases recurrence occurred.

Adolescent↗
PubMed1991

Patterns of erythropoiesis and anaemia in leprosy.

A total of 128 leprosy patients were investigated for the morphological type of anaemia, the underlying disturbances in iron metabolism and patterns of erythropoiesis and other cytomorphological changes in the bone marrow. The anaemia was a mild to moderate degree in paucibacillary (PB) leprosy, while in multibacillary (MB) leprosy it was of a severe degree. Iron deficiency was observed in only a few patients. Impaired iron utilization as observed in a anaemia of a chronic disorder was a common finding in MB leprosy (41.7%) and more so in new cases (50%). Megaloblastic erythropoiesis was also more frequent in MB leprosy (45.2%) as compared to PB leprosy (16%), accounting for the severe degree of anaemia in the former type. In 17.2% of the total patients (MB, 21.4%; PB, 9%) both megaloblastic erythropoiesis and features of impaired iron utilization were observed in bone marrow. Disturbances in iron metabolism and erythropoiesis were also observed but to a lesser degree in patients receiving specific antileprosy treatment. Irrespective of the type of disease and duration of treatment, increasing frequency of acid-fast bacillia (AFB) positivity and granulomas was observed in the bone marrow with an increasing severity of anaemia.

Anemia↗
PubMed1991

Tuberculosis of breast (study of 7 cases).

Seven cases of tuberculosis of breast are presented. The clinical features were multiple discharging sinuses, lump, ulcer and recurring abscess of breast. Diagnosis relied on histological appearance. Acid fast bacilli being present in only one specimen and positive culture obtained in one patient. Successful treatment combines antituberculous drug therapy with removal of infected breast tissue.

Adolescent↗
PubMed1990

Surgical management of malignant bone tumours.

Limb-salvage surgery has proved adequate in the management of malignant bone tumours. The goal of radical resection is to achieve local control with an appropriate surgical margin. Sixty-five cases of bone tumours have been managed by radical resection and suitable reconstruction by autologous fibular strut grafting. Single fibular grafting was attempted in the upper extremity and dual fibular grafting in the lower extremity. None had obvious evidence of secondary metastases at the time of surgery. out of 65 cases, 39 were sarcomatous lesions. Biplane Angiography had proved extremely useful in the exact delineation and appropriate resection of such lesions. Twenty two patients had complications - eight had local recurrence, three had deep infection needing amputation and eleven had multiple secondaries and died. It is suggested that in an Oncologically sound limb, salvage procedure with biological reconstruction should be attempted.

Adolescent↗
PubMed1990

Dual-fibular grafting for massive bone gaps in the lower extremity.

Fifty-two patients who had a tumor in the lower extremity (thirty-seven, a giant-cell tumor and fifteen, a small osteosarcoma that had not metastasized) had dual-fibular strut-grafting to bridge the osseous gap resulting from excision of the tumor. The size of the gap ranged from nine to twenty-four centimeters. The average time until union ranged from ten to twenty months. The ipsilateral fibula was used in thirty-six patients and both fibulae, in the remaining sixteen patients. Immediate reimplantation and adequate fixation of the fibular graft to the proximal and distal ends of the bone to be grafted, along with placement of a cuff of cancellous bone at the host-graft junction and between the fibular struts, fostered early union of the graft to the host bone. Insertion of Kirschner wires inside these long grafts helped to maintain continuity of the graft when a stress fracture occurred. Eight patients who had a non-union at one of the host-graft sites and three who had a stress fracture had subsequent cancellous bone-grafting to obtain union. Superficial infection was the most common complication and was seen in seventeen patients.

Adolescent↗