Biomedical subjects

K Kumar

Publications and source records attributed to K Kumar.

At least 73 records · Page 4Linked to original sources

PubMed1997

Effect of hypothermia on microglial reaction in ischemic brain.

Intra-ischemic hypothermia is known to protect neurons against ischemic injury. Microglial cells have been shown to become activated following ischemia and are speculated to play significant roles in the evolution of ischemic neuronal injury. In this study, we examined the effect of intra-ischemic hypothermia on the microglial reaction in the hippocampus following transient forebrain ischemia produced in gerbils by 10 min bilateral carotid occlusion at 30 degrees C or at 37 degrees C, followed by normothermic reperfusion for 1-7 days. Microglial cells were visualized by histochemical staining with isolectin-B4 from Griffonia simplicifolia. Brains subjected to normothermic ischemia showed activation of microglia at 1 day post-ischemia; this increased with further recirculation, becoming intense by 3 days and diminished by 7 days. Ischemia under hypothermic conditions was not associated with activation of microglia, and these brains showed no significant neuronal damage, whereas the brains subjected to normothermic ischemia showed extensive neuronal necrosis in the CA1 region after 1 and 7 days reperfusion. The presence of activated microglial cells in the CA1 region prior to and in parallel with evolution of ischemic neuronal damage, the lack of such activation in brains subjected to the neuroprotective action of intra-ischemic hypothermia, together with the known potential capability of microglial cells to release cytotoxic substances appear to indicate that these cells could contribute significantly to ischemic neuronal necrosis.

Animals↗

PubMed1997

Coronary blood flow velocities during rotational atherectomy.

This study was designed to evaluate the alterations in doppler derived coronary blood flow velocities and flow reserve following rotational ablation. Changes in doppler derived coronary blood flow velocity variables have been valuable in assessing the physiological outcome following coronary balloon angioplasty. Rotational ablation's mechanism of plaque removal could alter distal vascular bed characteristics, and, as a result, intracoronary blood flow velocities and the coronary flow reserve. A 12-MHz doppler guidewire recorded intracoronary phasic velocities and coronary flow reserve (as assessed by the hyperemic response to adenosine [12-18 mcg intracoronary]) in 28 patients, before and after rotational ablation of 30 lesions. Adjunctive balloon angioplasty was performed in 27 of 28 patients (96%). Rotational ablation and adjunctive balloon angioplasty successfully reduced the lesion diameter (87 +/- 9% to 14 +/- 11%; P < 0.001). A significant increase in the mean distal average peak velocity (25 +/- 13 cm/sec, before; 47 +/- 22 cm/sec, after; P < 0.001), and decrease in the proximal to distal average peak velocity ratio, (2.1 +/- 1.3; to 1.2 +/- 0.4; P = 0.002) was recorded. The mean distal diastolic to systolic velocity ratio (before, 1.4 +/- 0.7; after, 1.6 +/- 0.8; P = 0.44) and the coronary flow reserve (before, 1.6 +/- 0.6; after, 1.5 +/- 0.5; P = 0.34) did not increase despite increases in distal velocities, following successful intervention. Doppler derived distal coronary blood flow velocities increased following rotational ablation and adjunctive balloon angioplasty, with resolution of transstenotic velocity gradient. Changes in distal phasic velocity pattern and coronary flow reserve, immediately after the intervention, were not useful in the assessment of the functional outcome and may be related to abnormalities in distal vascular bed vasoreactivity produced by rotational ablation.

Aged↗

PubMed1997

GFAP-immunoreactivity following hypothermic forebrain ischemia.

This study investigated the effect of intra-ischemic hypothermia on astroglial reactions in the hippocampus following cerebral ischemia. Mongolian gerbils were subjected to forebrain ischemia by bilateral carotid occlusion of 10 min at a) 30 degrees C and b) 37 degrees C followed by normothermic reperfusion ranging from 1 to 3 days (d). The astrocytes were visualized by immunostaining against glial fibrillary acidic protein (GFAP), and neuronal injury was evaluated by using hematoxylin-eosin staining. In normothermic brains, reactive astrocytosis was noted in 1 and 2 d postischemic animals, becoming prominent in the 3 d postischemic group. Intense GFAP-positive cells with thickened processes were noted in all regions of the hippocampus, especially the CA1 region. These cells were seen to have migrated toward the stratum pyramidale which was normally devoid of such staining. Hypothermia significantly inhibited the GFAP-upregulation seen 3 d after normothermic ischemia. There was no significant neuronal damage in the 3 d hypothermic ischemic group. Since glial cell activation, as evidenced by GFAP-upregulation, precedes as well as accompanies neuronal damage, and since hypothermia, known to be neuroprotective, inhibits glial cell activation in the 3 d postischemic brain, it appears that glial cells play critical roles in neuronal survival or death following ischemia.

Animals↗

PubMed1997

Pure versus hybrid: performance implications of Porter's generic strategies.

This article identifies the strategic types in the hospital industry based on the hospital's use of Porter's generic strategies in their pure and hybrid forms. The article also examines differences in performance of hospitals across strategic types. Results indicate that hospitals that follow a focussed cost leadership strategy, in general, have superior performance on a variety of performance measures, while hospitals that use a combination of cost leadership and differentiation perform the poorest. Implications of findings for hospital administrators are also discussed.

Cost Control↗

PubMed1997

Spinal cord stimulation is effective in the management of reflex sympathetic dystrophy.

OBJECTIVE: The purpose of this study was to determine the efficacy of spinal cord stimulation (SCS) in patients with symptoms of reflex sympathetic dystrophy (RSD), a disabling clinical condition with significant consequences of morbidity and loss of productivity. METHODS: We have used epidural SCS for pain control during the past 15 years. An analysis of our records revealed 12 consecutive patients diagnosed as having RSD before undergoing SCS. Eight of the 12 patients had undergone previous ablative sympathectomy. The mean age of the nine men and three women was 38.2 years. All suffered extremity injuries from a variety of causes. RESULTS: All 12 patients experienced relief of pain after trial stimulation and had their systems permanently implanted. At an average of 41 months follow-up, all patients were using their stimulators regularly and only two were receiving adjunctive minor pain medication. The level of pain present pre- and postoperatively was determined by administering a modified McGill Pain Questionnaire and a visual analog scale to each patient. Eight patients reported excellent pain relief, and four patients described good results. Five minor complications occurred. CONCLUSION: SCS is an effective treatment for the pain of RSD, including recurrent pain after ablative sympathectomy. The low morbidity of this procedure and its efficacy in patients with refractory pain related to RSD suggest that SCS is superior to ablative sympathectomy in the management of RSD.

Adult↗

PubMed1997

Deep brain stimulation for intractable pain: a 15-year experience.

OBJECTIVE: During the past 15 years, we prospectively followed 68 patients with chronic pain syndromes who underwent deep brain stimulation (DBS). The objective of our study was to analyze the long-term outcomes to clarify patient selection criteria for DBS. METHODS: Patients were referred from a multidisciplinary pain clinic after conservative treatment failed. Electrodes for DBS were implanted within the periventricular gray matter, specific sensory thalamic nuclei, or the internal capsule. Each patient was followed on a 6-monthly follow-up basis and evaluated with a modified visual analog scale. RESULTS: Follow-up periods ranged from 6 months to 15 years, with an average follow-up period of 78 months. The mean age of the 54 men and 14 women in the study was 51.3 years. Indications for DBS included 43 patients with failed back syndrome, 6 with peripheral neuropathy or radiculopathy, 5 with thalamic pain, 4 with trigeminal neuropathy, 3 with traumatic spinal cord lesions, 2 with causalgic pain, 1 with phantom limb pain, and 1 with carcinoma pain. After initial screening, 53 of 68 patients (77%) elected internalization of their devices; 42 of the 53 (79%) continue to receive adequate relief of pain. Therefore, effective pain control was achieved in 42 of 68 of our initially referred patients (62%). Patients with failed back syndrome, trigeminal neuropathy, and peripheral neuropathy fared well with DBS, whereas those with thalamic pain, spinal cord injury, and postherpetic neuralgia did poorly. CONCLUSION: DBS in selected patients provides long-term effective pain control with few side effects or complications.

Adult↗

PubMed1997

Postoperative intravenous drip infusion is not required after minilaparotomy cholecystectomy.

OBJECTIVE: To determine if drip infusion should be discontinued after full recovery of the patient from anaesthesia after minilaparotomy cholecystectomy in uncomplicated cases. DESIGN: A randomised controlled clinical trial on 60 patients, from the waiting list, of cholelithiasis/cholecystitis operated by minilaparotomy cholecystectomy between November 1995 to March 1996. 30 patients did not receive postoperative i.v. drip infusion and in 30 patients 12-24 hours of standard drip transfusion was continued according to the current practice. SETTING: Single Surgical Unit, SS Hospital, Banaras Hindu University, Varanasi, India. MAIN OUTCOME MEASURE: Recognition of clinical indication for continuation of i.v. drip infusion after full recovery from anaesthesia. RESULTS: In the cohorts of 30 patients each who were or were not given i.v. drip infusion after full recovery from anaesthesia following minilaparotomy cholecystectomy the observations on pulse rate, blood pressure, time to first voiding of urine and time to start first oral intake of fluids were identical. However postoperative urinary retention occurred in 6 (20%) patients in whom the IV drip infusion was given. CONCLUSION: There is no clinical indication to continue IV drip infusion after full recovery from anaesthesia in patients operated for minilaparotomy cholecystectomy.

Adult↗

PubMed1997

Video-endoscopic and mini-endoscopic sympathectomy for hyperhidrosis.

Video-endoscopic sympathectomy (VES) is currently the method of choice for the minimally invasive treatment of hyperhidrosis involving the palms, armpit and facial areas. Over a 7-year period from 1991 to 1997 our technique of performing VES has evolved during the performance of 800 endoscopic sympathectomies from the use of 3 ports to a single 10-mm port to finally a 3-mm port using a mini-endoscope. In comparison to standard VES, mini-endoscopic sympathectomy is simpler, less invasive, causes less postoperative discomfort and consistently allows patients to return home the same day.

Adult↗

PubMed1997

Improvement of limb circulation in peripheral vascular disease using epidural spinal cord stimulation: a prospective study.

Spinal cord stimulation was used in 46 patients for pain associated with lower extremity ischemic vascular disease that was considered to be nonreconstructable. Thirty-nine patients who had a follow-up examination between 2 and 36 months after the procedure form the basis of this report. Thirty (77%) of 39 cases were considered successful. Clinical endpoints indicating failure included amputation, vascular reconstruction, poor pain relief, or hardware malfunction. The transcutaneous partial pressure of oxygen (TcPO2) increased in both target and control feet. In patients with good outcome with a preimplantation TcPO2 of less than 30 mm Hg, TcPO2 increased significantly (p < 0.05). Pulse volume recording improved significantly (p < 0.05) at the thigh, metatarsal, and great toe levels in successfully treated patients. Peak blood flow velocity also showed a significant increase in patients with good outcome (p < 0.05). Patients with a TcPO2 of less than 10 mm Hg following stimulation tended to undergo amputation within the first 3 months. Improvement in pain control, combined with an increase in TcPO2 values that was greater than 10 mm Hg, were significant early predictors of long-term success. An initial increase in peak blood flow velocities (measured in Doppler studies) of greater than 10 mm also signified a good long-term outcome. Spinal cord stimulation appears to be a useful therapeutic modality for controlling pain and improving perfusion in a select group of patients with end-stage ischemic vascular disease considered nonreconstructable. The best results were seen in patients with severe claudication and rest pain without trophic changes in the foot. The mechanism of this beneficial effect is not yet completely understood.

Aged↗

PubMed1997

Entomological and rodent surveillance of suspected plague foci in agro-environmental and feral biotopes of a few districts in Maharashtra and Gujarat states of India.

Studies carried out on entomological and rodent surveillance in agroclimatic and feral biotopes of five districts of Maharashtra and two districts of Gujarat revealed that the terrain features of the seven districts surveyed were conducive to wild rodent species, Tatera indica, a natural reservoir of plague and vector flea species, Xenopsylla cheopis. A total of 214 Tatera indica and three Bandicoota bengalensis were collected from burrows by the digging method and 89 rat fleas were retrieved. The flea index calculated ranged from 0.26 to 1.0 in different districts. The examination of blood serum samples, contact tissue impression smears and tissue organs (heart, lung, liver and spleen) of these wild rodents did not reveal any evidence of plague activity. The natural harbourages of Tatera indica were found to be elevated land or raised margins of agricultural fields or barren land with thorny bushes/xerophytic plants and parthenium grass. Agricultural fields having wet soil were found to be the preferred harbourages of Bandicoota bengalensis. Movement of wild rodents toward human settlement was observed to be the common phenomenon during the harvesting season which may lead to the creation of favorable conditions for plague outbreaks.

Animals↗

PubMed1997

Entomological and rodent surveillance in plague-suspected areas during September 1994 and thereafter.

Studies carried out in the states of Maharashtra, Gujarat, Uttar Pradesh and Union Territory of Delhi after the bubonic plague outbreak during 1994 revealed the presence of seven species of rodents, viz. Rattus rattus, R. norvegicus, Mus. musculus, Tatera indica, Suncus murinus, Bandicoota bengalensis and B. indica. The flea species encountered were Xenopsylla cheopis and X. astia. The X. cheopis and X. astia index recorded in different areas of Beed district of Maharashtra; Surat, Vadodra and Baruch districts in Gujarat and Varanasi district in Uttar Pradesh and their implications have been discussed. Insecticide suspectibility tests carried out against DDT, dieldrin, malathion and deltamethrin with X. cheopis collected from Maharashtra, Delhi and Varanasi revealed that this vector species is resistant to DDT and dieldrin but susceptible to malathion and deltamethrin. The prevalence and distribution of rodents species, high cheopis index and prevalence of Tatera indica just at the door steps of houses in village Mamla of Beed district provides highly congenital conditions for the intermingling of wild and domestic rodents and transfer of flea population from wild to domestic rodents and vice-versa. These conditions were found to be highly supportive for bubonic plague transmission in the district. The presence of Yersinia pestis antibodies in Rattus rattus collected from Beed, Surat and Varanasi areas are also indicative of bubonic plague in Beed and Varanasi and pneumonic plague in Surat during 1994.

Animals↗

PubMed1997

Performance-oriented: toward a successful strategy.

Changes in the health care industry have profoundly affected hospital management and have caused severe declines in hospital profitability. In 1993, Health Care Management Review reported that the average operating profit margin, around 2% in 1984, had declined to a 0.2% loss by 1990. In the past, hospitals were buffered by entry regulations and cost reimbursement; thus, they rarely dealt with traditional market pressures. But the changed terrain means that competitive factors now underscore all strategic decisions. This study examines the strategic significance of market orientation in the health care industry. The authors identified forms of market orientation by emphasizing different components, and discovered that hospitals fell into four distinct clusters or groups. They also found a critical relationship between market orientation and performance scores on a number of criteria. Finally, the authors suggest that different forms of market orientation should be employed to target specific performance measures.

Economic Competition↗

PubMed1997

Alteration of electronic relaxation in MR contrast agents through de-novo ligand design.

The longitudinal electronic state lifetime of the paramagnetic Gd metal within a macrocyclic ligand core can be increased by designing ligand frames that alter the vibronic interactions between the ligating atoms and the metal. We conducted the first pulsed EPR studies that demonstrated the increase in the longitudinal state lifetimes of the electronic subsystem at cryogenic temperatures. We also designed a simple sucrose/ water model that significantly increases the rotational correlation time in solution of the Gd chelate. This model system enables relaxivity studies at ambient temperatures that more readily interrogate exchange and electronic contributions to the inner-sphere relaxivity by effectively removing the rotational correlation time contribution. These results combined with water residence (Q) measurements suggest that rigidification of the macrocyclic core or that of the pendant arms increases the longitudinal electronic state lifetime of the paramagnetic Gd metal. This increased lifetime possibly contributes to the improved relaxivity for the rigid Gd chelates observed in the sucrose/ water model studies.

Chelating Agents↗

PubMed1997

Extended field trial of deltamethrin WDP for control of malaria at Jagdalpur, Madhya Pradesh, India.

The synthetic pyrethroid, deltamethrin 2.5% wdp, was evaluated at a dosage of 25 mg/sq m in a group of villages of tribal area around Jagdalpur, District Bastar (Madhya Pradesh). Study was carried out in three consecutive years from 1986 to 1988 with a total of five rounds of deltamethrin spray covering a population of approximately 10,000. The suspension of deltamethrin wdp was white in colour, odourless, non-irritant and the deposits were faintly visible on the surface of wall. A total of 3848 kg of 2.5% deltamethrin wdp was consumed during the trial. Insecticide was found effective in keeping the adult vector density An. culicifacies to a very low level for a period of 14-16 wks. Both anopheline and culicine mosquitoes were affected by the spray. The trial confirmed its long residual effectiveness from 15 to 16 wks on both mud and cement plastered surfaces. Deltamethrin spray shortened the average life span of vector mosquitoes. Observations indicated that insecticide although has an excito-repellent effect on mosquitoes, thus forcing exodus from treated area but with poor survival. Partial impact of deltamethrin spray was observed on the larval population confirm this. Deltamethrin spray did not exhibit any fumigant effect on mosquitoes. Significant decline in SPR from 17.93 to 4.26% was observed in areas sprayed with deltamethrin as compared to the comparison area. Similarly, SfR showed 81% reduction in experimental area while the control area showed increase by 42 per cent. No ill-effect of spray was noticed on the inhabitants, spray personnels, animal population and other non-target organisms of the area. The acceptability of the deltamethrin spray was found to be very high.

Animals↗

PubMed1996

Detection of coronary artery calcium to differentiate patients with early coronary atherosclerosis from luminally normal arteries.

Patients with angiographic evidence of early coronary atherosclerosis (<50% diameter stenosis) have a poorer prognosis than those with normal arteries and may benefit from more aggressive interventions targeted toward the primary prevention of cardiovascular disease. Using a calcium score of 5, fast computed tomography was able to identify 59% of patients with early atherosclerosis, while excluding 87% of patients with smooth, luminally normal coronary arteries.

Adult↗

PubMed1996

Effect of Surfactant Concentration and Film Area on the Stability of Films of Surfactant Solutions

The effect of surfactant concentration and film area on film stability was investigated in thin liquid films of sodium dodecyl sulfate (SDS) solutions. Film stability was evaluated at various concentrations of SDS solutions and various film areas. In this study, a maximum film stability was observed for the SDS concentration of 200 mM. Interestingly, this concentration also corresponds to the maximum micelle lifetime or long relaxation time (tau2). The results also show that film stability decreases with increasing film area, and that the larger films appear to be more sensitive to the micelle stability and structuring effect in the film than films with smaller surface areas.

Journal Article↗

PubMed1996

Dobutamine stress testing in the cardiac catheterization laboratory.

Dobutamine stress ventriculography is a safe test that appears to separate groups of patients with and without significant coronary artery stenoses. In this study, all 7 patients with significant coronary artery stenoses who reached a heart rate > or = 110 beats/min had a positive stress test, whereas 9 of 10 control patients had a negative stress test.

Adult↗

PubMed1996

Spinal deformity and axial traction.

Axial traction to correct spinal deformity is a very old concept. The oldest reference available is in ancient Hindu mythological epics (written between 3500 BC and 1800 BC) where it is mentioned how Lord Krishna corrected the hunchback of one of his devotees. Later, Hippocrates (460 BC to 377 BC) described certain devices. Galen (131 AD to 201 AD), a follower of Hippocrates, used axial traction with direct pressure. Ibn Sena (980 AD to 1037 AD) in the Middle East also used similar methods. Osteopaths of Turkey also used axial traction to correct spinal deformities. But gradually mechanical methods for the correction of the spinal deformity went into disrepute due to the invariable production of paraplegia. In the past few decades, interest in the correction of spinal deformity has been rejuvenated due to better understanding of anatomy, physiology, and pathomechanics of spinal deformity. Controlled axial traction has been the keystone of several modern procedures such as Cotrel traction, Halo traction, and Harrington Outrigger instrumentation, etc. It appears that the primitive ways of application of axial traction by crude methods did not totally vanish but have been modified. In Indian tribal areas, bone setters still practice it in modified form.

History, 20th Century↗