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Biomedical subjects

P V Sharma

Publications and source records attributed to P V Sharma.

15 recordsLinked to original sources

Changing patterns of atheroembolism.

Among 1011 patients undergoing infrarenal aortic and infrainguinal vascular surgery in a 90-month period (1986-1993), 29 patients (2.9%) with clinical, angiographic and pathologic evidence of atheroembolism were identified. Over one-third (44.8%) of atheroemboli were iatrogenic and the rest spontaneous. All iatrogenic atheroemboli were precipitated by angiographic (n = 11; 84.6%) or operative manipulation (n = 2; 15.4%). The sources of emboli were in the abdominal arota (16), iliac (seven) and femoropopliteal (six) arteries. 'Trash foot' occurred in 19 patients (seven bilateral) and occlusions of tibioperoneal/digital arteries were seen in seven, renal and dermal microcirculation in two each, and calf muscles in one. Larger conduits were affected in three instances (common femoral, popliteal and in situ saphenous vein graft). The management consisted of 54 (43 surgical and 11 endovascular) procedures concurrently with thrombolytic, anticoagulant and antiplatelet therapy. Three early (10.3%) and two late (6.9%) deaths (overall mortality rate 17.2%), eight major (27.6%) and five minor (17.2%) amputations, and four (13.8%) instances of renal failure occurred in 17 patients resulting in a 58.6% complication rate. Besides initial angiography, 53 invasive procedures were required in 25 patients. Among these, 12 patients could be managed with a single definitive procedure in contrast to a group of 13 patients that required 41 (average 3.2 per patient) procedures. The incidence of foot ischemia, reoperation and amputation was higher in the spontaneous group, whereas, the iatrogenic group incurred a higher incidence of endovascular interventions, greater mortality and new onset renal failure. The high morbidity and mortality of atheroemboli demand prompt recognition and treatment, as well as attempts at prevention to achieve good results.

Adult

Central and regional hemodynamics determine optimal management of major venous injuries.

Controversy continues in the selection of optimal management of major venous injuries. We analyzed our experience with 191 major venous injuries in 163 patients (1986 to 1991). The mechanism of injury was gunshot (112), stab (44), blunt (six), and iatrogenic (one). Eighteen cervicothoracic, 51 caval, 30 iliac, 36 visceral, and 56 extremity veins were involved. Of the 191 injuries, 105 (54.9%) were repaired (lateral repair 76, end-to-end anastomosis 15, vein patch four, vein graft five, Gore-Tex graft four, and compilation one). Of the remaining venous injuries, 64 were ligated as a result of hemodynamic instability. Twenty-two injuries in 18 patients did not receive treatment because 16 of 18 patients died before vascular control or repair. The overall amputation rate was 1.2%, and the mortality rate was 28.2% (46/163). The highest mortality rate occurred in those patients who required resuscitative thoracotomy (100%, p < 0.00001), retrohepatic caval injuries (90%, p < 0.0004), and multiple venous injuries (81.8%, p < 0.00001). Seventeen patients underwent fasciotomies (15 prophylactic and two therapeutic). Clinical or measured venous hypertension by stump pressure assisted in deciding for venous repair in 20 patients. A significant decrease in venous stump pressure (p < 0.000001) was noted after venous reconstruction. Thus the decision to ligate or repair venous injuries correlated primarily with (1) hemodynamic stability, and in stable patients, with (2) extent and location of injury and (3) clinical and measured venous hypertension. Venous ligation in clinically stable patients did not increase the need for fasciotomy or amputation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Meticulously restored lumina of injured veins remain patent.

We report our experience with 38 major venous injury repairs in 37 patients between January 1981 and December 1989. The injuries were caused by gunshot (n = 27), shotgun (n = 3), knife (n = 5), blunt trauma (n = 1), and dog bite (n = 1). These involved 27 femoral, 10 popliteal, and one brachial veins. Thirty patients had associated major arterial injuries and seven had major long bone fractures. Retrospective analysis yielded two groups. Group I consisted of 17 patients who underwent meticulous restoration of venous lumina ensured by intraoperative postreconstruction venography (IPV) in all patients. Two of these required revision on the basis of IPV findings. Late patency of venous repair was confirmed by postoperative venography (n = 10) or duplex scans (n = 7). All 17 venous repairs were patent (100%). In group II none of the 20 patients (21 veins) underwent IPV. Fifteen of the 20 patients underwent venography and five patients (six veins) underwent duplex scanning after surgery. Eight veins were occluded and 13 (62%) were patent. The difference in patency rates of venous repair between groups I and II was significant (p = 0.02). Three (37.5%) of eight patients with occluded venous repair required delayed fasciotomy, but only 1 (3.4%) of 29 limbs (30 veins) with patent lumina required fasciotomy (p = 0.03). We conclude that meticulous restoration to normal-caliber venous lumina, confirmed by IPV, can achieve high patency and low morbidity rates.

Adolescent

Monitor-guided responses. Operability with safety is increased in patients with peripheral vascular diseases.

Poor cardiopulmonary reserve was demonstrated in a group of 75 elderly patients undergoing elective vascular reconstruction when cardiovascular hemodynamics were analyzed with the automated physiologic profile (APP) preoperatively. Only 25 patients (33.3%) had normal left ventricular function (LVF) and did not need any corrective therapy before surgery. Increment in preload was necessary in 20 patients (26.7%) to improve myocardial function; 30 patients (40%) revealed abnormal LVF and hence required pharmacologic modulation and preload adjustment, inotropic support, and afterload reduction to enhance the ventricular performance. Conventional methods of clinical evaluation did not reveal the degree of compromised ventricular function and potential high risk of surgical morbidity and mortality in many of these patients. The APP disclosed subtle and important physiologic aberrations indicating modification of anesthetic and operative procedures and precise modulation of physiologic factors. Optimization was achieved in all except two patients, and only one was denied the benefits of vascular reconstruction.

Aged

Chemical constituents of gentianaceae XXIII: tetraoxygenated and pentaoxygenated xanthones and xanthone O-glucosides of Swertia angustifolia Buch.-Ham.

The whole plant extract of Swertia angustifolia Buch.-Ham., collected at different stages of growth, contained 14 tetraoxygenated and five pentaoxygenated xanthones and xanthone 1-O-glucosides. Of the eight xanthone 1-O-glucosides isolated, five were previously unreported in nature. The xanthones are broadly based on 1,3,5,8- and 1,3,7,8-oxygenated systems, with an added oxygen function at C-4 in some compounds, and represent a number of methoxylated patterns. The content and relative abundance of the free xanthones and their 1-O-glucosides changed with plant growth. These results are the first demonstration of the variation in chemical characters in the different parts of a Swertia species during its ontogeny. The biolgocial significance of these results is appraised.

Glucosides

Chemical constituents of Gentianaceae XIX: CNS-depressant effects of swertiamarin.

CNS activity of swertiamarin, a secoiridoid glucoside from Swertia chirata, was evaluated. An apparent anomaly, associated with the unanticipated finding that the alcoholic extracts (excluding mangiferin) of S. chirata significantly reversed the mangiferin-induced CNS-stimulating effects in albino mice and rats, was resolved. The results indicate that swertiamarin and mangiferin antagonize each other in vivo and thereby reverse their CNS effects.

Amphetamine

Chemical constituents of gentianaceae XIV: tetraoxygenated and pentaoxygenated xanthones of Swertia purpurascens Wall.

The whole plant of Swertia purpurascens Wall. (Gentianaceae) has been shown to contain five tetraoxygenated and three pentaoxygenated zanthones. These are identified as 1,5,8-trihydroxy-3-methoxyxanthone, 1,3,8-trihydroxy-5-methoxyzanthone, 1-hydroxy-3,7,8-trimethoxyxanthone, 1,3,7,8-tetrahydroxyxanthone, 1,3,5,8-tetrahydroxyxanthone, and 1-hydroxy-3,4,7,8-tetramethoxyxanthone by chemical and spectral evidence. Additionally, the crude mixture of natural xanthones has been shown to include two partially emthylated pentaoxygenated xanthones as minor entities, which yield 1-hydroxy-3,4,7,8-tetramethoxyxanthone and 1-hydroxy-3,4,5,8-tetramethoxyxanthone on methylation. This is the first time that pentaoxygenated xanthones have been found in a member of the genus Swertia. 1-Hydroxy-3,4,7,8-tetramethoxyxanthone was previously known only as a synthetic compound. The total xanthones of S. purpurascens produce significant CNS stimulant actions, consistent with some therapeutic uses of the plant extract in the Indian system of medicine. The chemotaxonomic significance of the cooccurrence of various biogenetically related chemical characters in a single plant species is appraised.

Amphetamine

Bullet embolism.

Bullet embolism is a rare complication of vascular trauma. During the last ten years we have treated six patients with bullet embolism. Three patients had inferior vena caval injuries with embolizations of the bullets to the heart or pulmonary arteries. Two had infrarenal aortic injuries with embolization to vessels of the lower extremities. One patient with a shotgun injury to the superficial femoral artery and vein had both arterial and venous embolizations. The site of vascular penetration was repaired in all six patients. All peripheral arterial bullet emboli were removed except for an asymptomatic shotgun pellet in the peroneal artery. One bullet was removed from a right atrium and another from a proximal pulmonary artery. Emboli in the distal pulmonary artery branches were left undisturbed in two patients. All six patients survived without any complications. A 14-year review of the literature is presented in order to emphasize some important features of this rare pathology.

Adult

Changing patterns in civilian arterial injuries.

A critical review of 185 patients with 211 arterial injuries over an eleven year period was performed to recognize the changing patterns in clinical findings, management and results. A ten fold increase in multiple arterial injuries as well as higher incidence of associated venous and visceral injuries occurred during the last five years. Despite this, the incidence of hypotension on arrival at hospital was reduced by half due to rapid transportation and resuscitation during transit. Shock in patients with only extremity injuries heralded dual injuries (arterial and venous). Lateral repair of both arterial and venous injuries has given way to end to end anastomoses, vein grafts and patch grafts. A greater tendency to repair all major arteries, most minor arteries, more liberal use of heparin, fasciotomy, intraluminal shunts, repair of venous injuries and extra-anatomic bypass has been noted. Rapid patient retrieval, early resuscitation, improved recognition and management of arterial injuries has not lead to better limb salvage or survival. The apparent lack of benefit in limb salvage is probably due to the higher incidence of multiple arterial injuries and associated venous injuries as well as the willingness to attempt repair all major arterial injuries and reluctance to advise primary amputation. Early patient retrieval, rapid transportation and resuscitation during transit has increased the number of potentially unsalvageable patients (who would otherwise be declared dead on arrival) resulting in an unchanging mortality.

Accidents, Traffic