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Biomedical subjects

S K Mishra

Publications and source records attributed to S K Mishra.

At least 19 recordsLinked to original sources

Safety and efficacy of surgical management of hyperthyroidism: 15-year experience from a tertiary care center in a developing country.

BACKGROUND: Ideal management of toxic goiter still remains elusive. Though surgical management of toxic multinodular goiter (MNG) is well accepted, surgical treatment of Graves' disease (GD) is still controversial in view of the presumed increased incidence of complications. In this paper, we discuss the experience of the surgical management of hyperthyroidism at a specialized tertiary care endocrine center in a developing country, highlighting the minimal morbidity and satisfactory outcome in experienced hands. MATERIALS AND METHODS: We retrospectively reviewed 325 consecutive patients with hyperthyroidism managed surgically from 1990 to 2005. The etiologic diagnoses were Graves' disease (185), toxic MNG (105), and autonomously functioning thyroid nodules (AFTN) (n = 35). The indications for surgery in Graves' patients were large goiter, relapse after antithyroid drug therapy (ATD), Graves' ophthalmopathy, and presence of nodule. The indications for surgery in toxic MNG were retrosternal extension (n = 15), compressive symptoms (n = 20), and large size (grade II). Among the AFTN nodule size, those greater than 4 cm (85%) formed the major indication for surgery. Subjects with GD and toxic MNG were subjected to subtotal thyroidectomy (n = 93 prior to 1995) or total thyroidectomy (n = 205 post-1995). Hemithyroidectomy was the procedure of choice in patients with AFTN. RESULTS: Patients with Graves' disease were younger in age, with shorter mean duration of goiter when compared with the other 2 groups. Eight percent of patients with Graves' disease without a clinically palpable nodule and 25% of those with nodules had associated differentiated carcinoma, including papillary, follicular, and medullary thyroid cancer. Four percent of patients with toxic MNG had malignancy. Complications included temporary hypocalcemia (24%), permanent hypocalcemia (3%), and permanent vocal-cord palsy (1%). CONCLUSIONS: Surgery for hyperthyroidism has negligible mortality and acceptable morbidity in experienced hands. It is a definite option in selected cases. Immediate and permanent cure of hyperthyroidism is achieved, with no recurrences, after total thyroidectomy. The cosmetic outcome is good, with excellent patient satisfaction and acceptance.

Adult↗

The external laryngeal nerve in thyroid surgery: the 'no more neglected' nerve.

AIMS: To describe a novel surgical technique of 'lateralization' of superior pole to identify and save external branch of superior laryngeal nerve (EBSLN) during thyroidectomy. SETTINGS AND DESIGN: Prospective, nonrandomized at a tertiary care hospital in a specialized unit. MATERIAL AND METHODS: Over 30 months, 46 patients underwent thyroidectomy using technique of 1) 'Lateralization' of upper pole and dissection of avascular cricothyroid space 2) identification of EBSLN 3) skeletonization and individual ligation of superior thyroid vessels. Identified nerves were classified according to Cernea's classification. Outcomes were number of nerves identified, number of 'at risk' nerves' bilateral asymmetry and incidence of injury assessed by subjective interview and indirect laryngoscopy. RESULTS: Of the 78 dissected superior poles, nerves could be identified in 72 (92.31%). There were 22 (28.2%) type I, 42 (53.54%) IIa and 8 (10.25%) IIb 'at risk' nerves. In 32 patients with bilateral dissections, asymmetry of nerve was noted in 15%. Injury to nerve was not recorded in any of the patients. Average weight of glands was 69.59 g. Thyroidectomy was performed for benign disease in 28, malignancy in 4 and thyrotoxicosis in 14 patients. CONCLUSIONS: With technique of 'lateralization' and 'skeletonization and individual ligation of the superior vessels,' EBSLN identification increases and injury can be prevented. These results relate to the utilization of specific surgical technique and it is reasonable to expect that most surgeons, once familiar with the technique, should be able to achieve similar outcomes.

Adolescent↗

Telementoring in endocrine surgery: preliminary Indian experience.

Telemedicine is starting to play an important role in the health field in India. In this case report we describe the successful use of telementoring to remove a parathyroid tumor in a patient with residual hyperparathyroidism after two previous unsuccessful attempts in tumor excision. A 21-yr-old patient crippled with advanced hyperparathyroidism was taken up for third-time exploration at Amrita Institute of Medical Sciences (AIMS), Kochi, with guidance from the Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, using telemedicine technology. These two centers are located 2,500 km apart, and telementoring from the more experienced endocrine surgeons at SGPGIMS resulted in successful tumor localization and removal. For this session both the institutions were provided with a dedicated 512 Kbps very small aperture terminal (VSAT) link and two-way video-audio connectivity. Even though two previous explorations were unsuccessful, with the help of telemedicine technology the same surgeon was successful in locating and removing the tumor. The video and audio quality was of good enough quality for the expert at SGPGIMS to guide the team at AIMS satisfactorily. The patient benefited since he did not have to travel to a far-off specialized center for surgery. This case report testifies to the usefulness of telemedicine in the field of surgery, especially in developing countries, which have few medical experts in certain specialized areas.

Adult↗

Hypothyroid state reduces calcium channel function in 18-day pregnant rat uterus.

Hypothyroidism significantly reduced the mean amplitude and increased the mean frequency of spontaneous rhythmic contractions in 18 day pregnant rat uterus. Nifedipine (10(-12)-10(-9) M) and diltiazem (10(-10)-10(-6) M) caused concentration related inhibition of the myogenic responses of the uterine strips obtained from both pregnant and hypothyroid state. However, nifedipine was less potent (IC50:2.11 x 10(-11) M) in pregnant hypothyroid state as compared to pregnant control (IC50: 3.1 x 10(-12) M). Similarly, diltiazem was less potent (IC50: 3.72 x 10(-9) M) in inhibiting the uterine spontaneous contractions in hypothyroid than in pregnant rat uterus (IC50:5.37 x 10(-10) M). A similar decrease in the sensitivity to nifedipine and diltiazem for reversal of K+ (100 mM)-induced tonic contraction and K(+)-stimulated 45Ca2+ influx was observed with these calcium channel antagonists in uterus obtained from hypothyroid pregnant rats compared to the controls. Nifedipine-sensitive influx of 45Ca(2+)-stimulated either by K+ (100 mM) or by Bay K8644 (1,4-dihydro-2,6-methyl-5-nitro-4-[2'-(trifluromethyl)phenyl]-3-pyridine carboxylic acid methyl ester) (10(-9) M) was significantly less in uterine strips from hypothyroid rats compared to controls. The results suggest that the inhibition of uterine rhythmic contractions may be attributable to a reduction in rat myometrial Ca2+ channel function in the hypothyroid state.

Animals↗

Efficacy and safety of beta-arteether and alpha/beta-arteether for treatment of acute Plasmodium falciparum malaria.

One hundred thirty-eight adult patients with acute Plasmodium falciparum malaria were randomized to receive either beta-arteether or alpha/beta-arteether. The drugs were administered in the dose of 150 mg once a day intramuscularly for three consecutive days in hospitalized patients. After one week of hospitalization, patients were followed-up for three weeks after release from the hospital. There was no statistically significant difference between cure rates, mean fever clearance time (FCT), mean parasite clearance time (PCT), and occurrence of side effects in either group. The cure rate was 97.14% for beta-arteether and 97.01 for alpha/beta-arteether (P = 0.9660). The mean PCT was 38.49 hours for beta-arteether and 36.90 hours for alpha/beta-arteether (P = 0.6054), and the mean FCT was 37.27 hours for beta-arteether and 37.9 hours for alpha/beta-arteether (P = 0.8718). Both arteether formulations were safe and efficacious in reducing the clinical symptoms of acute falciparum malaria. There was also rapid clearance of parasitemia with both formulations. Thus, either beta-arteether or alpha/beta-arteether can be used in the treatment of acute falciparum malaria.

Adolescent↗

Adjuvant therapy in cerebral malaria.

Cerebral malaria is the most common cause of non-traumatic encephalopathy in the world. The mainstay of therapy is either quinine or artemisinin, both of which are effective antimalarials. The clinical picture of cerebral malaria may persist or even become worse in spite of the clearance of parasites from blood. The death rate is unacceptably high even with effective antimalarials in tertiary care hospitals. The mortality increases in presence of multi organ failure (renal failure, jaundice, respiratory distress, severe anaemia, lactic acidosis, etc.). The pathogenesis of cerebral malaria is multifactorial and includes clogging, sequestration, rosette formation, release of cytokines, cerebral oedema, increased intracranial hypertension, etc. Attempts are made to use adjuvant therapy which will act through alternate mechanisms and address one or more of the pathogenetic processes. In this review, we have discussed the role of corticosteroids, pentoxifylline, desferrioxamine, mannitol and newer agents in the treatment of cerebral malaria. Though the literature on adjuvant therapy in cerebral malaria is large enough, there are a number of shortcomings in the clinical trials, many being open and non randomized or of very small sample size. Further research is of utmost importance through large multicentric, double-blind controlled trials to show the efficacy of any of these drugs.

Adrenal Cortex Hormones↗

Effects of oxidizing and reducing agents on ovine pulmonary artery responses to nitric oxide donors, sodium nitroprusside and 3-morpholino-sydnonimine.

Nitrovasodilators-sodium nitroprusside (SNP; 10(-9)-10(-4) M) and 3-morpholino-sydnonimine (SIN-1; 10(-9)-10(-4) M) produced concentration-dependent relaxation of the fourth generation sheep pulmonary artery, preconstricted with 5-hydroxytryptamine (1 microM). Oxidizing agents [oxidized glutathione (GSSG, 1 mM) and CuSO4 (5 and 20 microM)] and reducing agents [dithiothreitol (DTT, 0.1 mM), ascorbic acid (1 mM) and reduced glutathione (GSH, 1 mM)] caused opposite effects on nitric oxide (NO)-induced vasodilation in the artery. Ascorbic acid and GSH potentiated the NO responses, while GSSG and CuSO4 inhibited relaxation caused by the nitrovasodilators. DTT, however, reduced the relaxant potency and efficacy of SNP and SIN-1. Pretreatment of the pulmonary artery strips with DTT (0.1 mM) inhibited SNP (10 microM)-induced Na(+)-K(+)-ATPase activity, while ascorbic acid (1 mM) and GSH (1 mM) had no effect either on basal or SNP (10 microM)-stimulated 86Rb uptake, an index of Na(+)-K(+)-ATPase activity, in ovine pulmonary artery. The results suggest that reducing agents like ascorbic acid may have beneficial effect in improving the vascular function under oxidative stress.

Animals↗

Studies on the adsorption of Brij-35 and CTAB at the coal-water interface.

The adsorption behavior of polyoxyethylene (23) lauryl ether (Brij-35) and cetyl trimethyl ammonium bromide (CTAB) on coal sample has been studied. The adsorption process is found to be sensitive to pH, temperature, electrolyte concentration, and the amount of surface active agent. An attempt has been made to explain the adsorption behavior of the surfactants using the Langmuir equation. The extent of adsorption of Brij-35 on coal is found to be the highest at pH 2, which decreases with increase in pH and remains constant in the neutral and alkaline pH regions. But, the adsorption of CTAB exhibits the opposite behavior of that of Brij-35. Adsorption of any of the surfactant at the coal/water interface sharply decreases the apparent viscosity of 55 wt% coal-water slurry (CWS) at a shear rate of 100 s(-1). Electrostatic adsorption of the surfactants on the coal surface decreases the surface charge and renders the coal surface hydrophobic which is manifested in the form of high apparent viscosity of the coal-water slurry under the test conditions.

Journal Article↗

Telemedicine in neurology: underutilized potential.

Advances in telecommunication which started with telephone lines, FAX, integrated service digital network (ISDN) lines and now internet have provided an unprecedented opportunity for transfer of knowledge and sharing of information. The information can be used for overlapping applications in patient care, teaching and research. In medicine there is increasing utilization of telemedicine; radiology and pathology being regarded as mature specialties and emergency medicine as maturing specialties compared to other evolving specialties which include psychiatry, dermatology, cardiology and ophthalmology. Of the emergencies, status epilepticus and stroke have high potential for improving patient management. Administration of tPA was more frequent when carried out under telemedicine guidance. Telemedicine has great potential for medical education. The principles of education are in congruence with those of telemedicine and can be closely integrated in the existing medical education system. Our experience of telemedicine as a medical education tool is based on video conferencing with SCB Medical College, Cuttack. We had 30 sessions during 2001 to 2004 in which 2-3 cases were discussed in each session. The patients' details, radiological and neurophysiological findings could be successfully transmitted. These conferences improved the knowledge of participants, provided an opportunity for a second opinion as well as modified the treatment decisions in some cases. The advances in telemedicine should be utilized more extensively in neurology, especially in emergency management, epilepsy and stroke patients as well, as it may have a role in neurophysiology and movement disorders.

Education, Medical↗

Effects of calcium channel blocker, mibefradil, and potassium channel opener, pinacidil, on the contractile response of mid-pregnant goat myometrium.

The present study was undertaken to investigate the in vitro influence of mibefradil, a calcium channel blocker, and pinacidil, a potassium channel opener, on pregnant goat myometrial spontaneous rhythmic contractility and contractions induced with the agonist, oxytocin. Longitudinal strips from the distal region of uterus, collected from goats at midgestation, were mounted in an organ bath for recording isometric contractions. Mibefradil (10(-8)-10(-4) M) or pinacidil (10(-10)-10(-4) M), added cumulatively to the bath at an increment of 1 log unit, caused concentration-dependent inhibition of the spontaneous rhythmic contractions of isolated uterine strips. The rhythmic contraction was, respectively, abolished at 100 and 10 microM concentrations of mibefradil and pinacidil. In a concentration-dependent manner, mibefradil (1 and 10 microM) antagonized the contractions elicited with oxytocin (10(-5)-10(-2) IU). Pretreatment of uterine strips with glibenclamide (10 microM), a selective KATP channel blocker, caused a rightward shift of the concentration-response curve of pinacidil with a concomitant decrease in its pD2 value. Pinacidil (0.3, 1 and 3 microM), in a concentration-related manner, antagonized the oxytocin (10(-5)-10(-2) IU)-induced contractile response. The inhibition of spontaneous rhythmic contractions and antagonism of oxytocin-induced contraction by mibefradil in the pregnant goat myometrium may be related to the antagonism of voltage-dependent Ca2+ channels, while by pinacidil suggests that KATP channel could be a therapeutic target for tocolysis.

Adenosine Triphosphate↗