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Biomedical subjects

S Datta

Publications and source records attributed to S Datta.

At least 397 records · Page 22Linked to original sources
PubMedDate not supplied

Designing and testing of an effective oil-in-water microemulsion drug delivery system for in vivo application.

The phase behavior of a new psedoternary system of clove oil/Tween 20 has been studied. Several compositions from the single-phase region were selected and their stability toward time, temperature, and electrolytes has been examined. A particular composition(clove oil/Tween 20/water as 5/30/65) was chosen as the drug delivery system from the clear oil-in-water zone of the pseudoternary system. The droplet dimension and the polydispersity state of the particular composition was determined by dynamic light scattering. A bioactive compound quarcetin was encapsulated in the vehicle. The efficacy of the drug in the vehicle was examined against leishmaniasis in hamster models. The hepatotoxicity of the vehicle (o/w microemulsion) with and without the drug quarcetin was examined by estimating serum alkaline phosphatase, glutamate pyruvate transaminase, urea, and creatinine.

Animals↗
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New pharmaceutical microemulsion system for encapsulation and delivery of diospyrin, a plant-derived bioactive quinonoid compound.

A new vegetable oil based oil-in-water microemulsion is developed and characterized as a prospective delivery system for in vivo application A particular weight percent composition 5/30/65 (clove oil/Tween-20/water) was selected (V1) from the clear oil-in-water zone of the pseudoternary phase diagram comprising clove oil, polyoxyethylene sorbitan monolaurate (Tween-20), and water. Two modifications of V1, (V2 and V3) were prepared by addition of dipalmitoyl phosphatidyl choline (DPPC), and a mixture of DPPC and cholesterol, respectively. A model drug diospyrin (a plantderived quinonoid compound) was encapsulated in the dispersed clove oil droplets of the three systems and designated as DV1, DV2, and DV3, respectively. The size of the dispersed clove oil droplets ranged between 9-20 nm as determined by dynamic light scattering. The stability of the vehicles, before and after encapsulation, was assessed under varying conditions of time and temperature and was found to be stable for 1 year and over a temperature range of 4-40 degrees C. The ultraviolet-visible spectrum of diospyrin after encapsulation in the compartmentalized medium remained almost identical to that dissolved in chloroform. The single-dose acute toxicity of V1 and DV1 was assessed in vivo by carrying out survival study and enzyme assay in Swiss Albino mice. The vehicle was safe at a volume of 0.05 ml when injected intraperitoneally into the mice.

1,2-Dipalmitoylphosphatidylcholine↗
PubMedDate not supplied

Electron beam depth dose scaling by means of effective atomic number reconstructed from CT scans.

A method is developed by which the computed tomography scans of a medium carried out at a number of diagnostic energies can be utilized to obtain the in situ "Effective Atomic Number" and "Effective Density". The electron depth dose curves in water when scaled by these factors estimate the actual electron depth dose distribution in that medium. It appears that the use of CT scans for electron beam treatment planning, in the management of cancer, is quite promising.

Electrons↗
PubMedDate not supplied

Fine needle aspiration cytology of undifferentiated (embryonal) sarcoma of the liver: a case report.

BACKGROUND: Undifferentiated sarcoma of the liver is a rare tumor of childhood. The histology has been well documented, but the histogenesis is controversial. The cytologic characteristics of this neoplasm in aspiration material have not been previously documented. CASE: The cytologic features in a 9-year-old male were pleomorphic malignant cells, multinucleate giant cells, numerous hyaline globules and myxoid matrix. CONCLUSION: The cytologic features of undifferentiated sarcoma of the liver are distinctive and different from those of other childhood liver tumors. Awareness of the tumor's cytomorphology can result in a confident preoperative diagnosis.

Biopsy, Needle↗
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Vibrio cholerae O139 in Calcutta, 1992-1998: incidence, antibiograms, and genotypes.

We report results of surveillance for cholera caused by Vibrio cholerae O139 from September 1992, when it was first identified, to December 1998. V. cholerae O139 dominated as the causative agent of cholera in Calcutta during 1992-93 and 1996- 97, while the O1 strains dominated during the rest of the period. Dramatic shifts in patterns of resistance to cotrimoxazole, neomycin, and streptomycin were observed. Molecular epidemiologic studies showed clonal diversity among the O139 strains and continuous emergence of new epidemic clones, reflected by changes in the structure, organization, and location of the CTX prophages in the V. cholerae O139

Base Sequence↗
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Perioperative analgesia with subarachnoid sufentanil administration.

BACKGROUND AND OBJECTIVES: Thirty-seven ASA Physical Status I parturients undergoing elective cesarean delivery were evaluated to determine the effects of subarachnoid sufentanil administration. METHODS: This study was carried out in a randomized, double-blind fashion. All patients received 1.4 ml 0.75% bupivacaine with 8.25% dextrose following 10 micrograms, 15 micrograms, or 20 micrograms sufentanil, or 1 ml of normal saline containing no sufentanil. Onset and duration of sensory and motor anesthesia, duration of complete analgesia, duration of effective analgesia, and intraoperative parenteral opioid requirements were evaluated. Incidence of side effects such as respiratory depression, pruritus, nausea, and vomiting were evaluated. RESULTS: Duration of complete analgesia and duration of effective analgesia were prolonged significantly in all patient groups receiving sufentanil as compared to control groups receiving no narcotic. Pruritus was significantly increased in patient groups receiving subarachnoid sufentanil. Respiratory depression was not observed in any patient studied. One- and five-minute Apgar scores; umbilical, venous, and arterial blood gas results; and Early Neonatal Neurobehavioral Scale results were all within normal limits and were not significantly different among the groups.

Adult↗
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Continuous pump pressures cannot be used to identify catheter tip migration into the subarachnoid space.

BACKGROUND AND OBJECTIVES: Migration of an epidural catheter into the subarachnoid space is a potentially lethal complication of continuous epidural anesthesia. We evaluated the use of pump pressure measurement during infusion in detecting such an occurrence. METHODS: Pump pressures at two flow rates (P1 and P10) and epidural space pressure (P0) were measured hourly in eight consecutive ASA Physical Status I parturients receiving continuous epidural anesthesia and compared to those of a patient whose catheter migrated into the subarachnoid space. In addition, total resistance to infusion (Rtot) was calculated as the slope of the least squares regression line linking pressure and flow. Epidural resistance (Repi) was computed as the difference between total resistance and catheter resistance; Repi = Rtot - Rcath. RESULTS: In epidural catheters, average P0 and P10 were 13 +/- 4 mmHg and 23 +/- 4 mm Hg, respectively, and did not change over time. Rtot and Repi averaged 960 +/- 180 RU and 980 +/- 120 RU, respectively. Pump pressures in the subarachnoid catheter were 10 mmHg for P0 and 20 mmHg for P10, while Rtot was 1000 RU. CONCLUSIONS: We conclude that epidural and subarachnoid space resistance is essentially zero and the pump pressure in the system is used to overcome the catheter resistance. Both spaces offer the same total resistance to infusion and, therefore, pump pressure will not change when a catheter migrates into the subarachnoid space.

Anesthesia, Epidural↗
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Status of maternal and new born care at first referral units in the state of West Bengal.

A study was conducted in 12 First Referral Units (FRUs), selected through multistage sampling, from 6 districts of West Bengal. Infrastructure facilities, record keeping, referral system and MCH indicators related to newborn care were documented. Data was collected by review of records, interview and observation using a pre-designed proforma. Inadequate infrastructure facilities (e.g. no sanctioned posts of specialists, no blood bank at rural hospitals declared as First Referral Units etc.); poor utilization of equipment like neonatal resuscitation sets, radiant warmer etc, lack of training of the service providers were evident. Records/registers were available but incomplete. Referral system was found to be almost nonexistent. Most of the deliveries (86.1%) were normal delivery. Deliveries (87.71%) and immediate neonatal resuscitation (94.9%) were done mostly by nursing personnel. Institution based maternal, perinatal and early neonatal mortality rates were found to be 5.6, 62.4 and 25.2 per 1000 live births respectively. Eclampsia (48.9%), hemorrhage (17.7%), puerperal sepsis (7.1%) were reported to be major causes of maternal mortality. Common causes of early neonatal mortality were birth asphyxia (54.3%), sepsis (14.6%) and prematurity/LBW (12.4%).

Documentation↗
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Regional anesthesia in women with chorioamnionitis.

BACKGROUND AND OBJECTIVES: Controversy regarding the use of regional anesthesia in parturients with chorioamnionitis stems from concern that, in bacteremic patients, anesthetic technique may result in infectious complications because of "seeding" of the epidural or subarachnoid space. This study attempts to evaluate the outcome of the parturient with chorioamnionitis based on anesthetic technique. METHODS: Data on chorioamnionitis was collected by review of all obstetric deliveries over a 1-year period with respect to type of anesthetic administered, blood culture results, antibiotic administration, and outcome. RESULTS: Three hundred nineteen women with chorioamnionitis were identified from a total of 10,047 deliveries over a 1-year period. Bacteremia was found in eight of these patients, three of whom received epidural anesthesia. None had received antibiotics before induction of anesthesia. No infectious complications related to anesthetic technique were found. Mean temperature and leukocyte counts were not significantly different between bacteremic and nonbacteremic groups. CONCLUSIONS: Although the total number of patients in this study is small, there is no evidence that regional anesthesia was detrimental to patients with chorioamnionitis. Factors such as leukocyte count and temperature elevation may not be predictive in identifying the bacteremic subgroup of patients.

Adult↗
PubMedDate not supplied

The antiemetic efficacy and safety of prophylactic metoclopramide for elective cesarean delivery during spinal anesthesia.

BACKGROUND AND OBJECTIVES: The efficacy and safety of intravenous metoclopramide administered prophylactically before elective cesarean delivery under spinal anesthesia was studied. METHODS: In a double-blind, randomized fashion, 42 ASA Physical Status I-II parturients at term were assigned to receive either 10-mg intravenous metoclopramide or an equal volume of normal saline before induction of spinal anesthesia. The occurrence of nausea and/or vomiting recorded throughout the perioperative period until the patient was admitted to the recovery room. Neonatal acid-base status and neurobehavioral exams were obtained. RESULTS: Patients in the group receiving metoclopramide had a significantly lower incidence of nausea and vomiting both before and after delivery than the control group (14% versus 81% overall). All neonatal acid-base values were within normal limits and there were no significant differences in neurobehavioral exam results between the two groups. CONCLUSIONS: Metoclopramide administered before induction of spinal anesthesia for cesarean delivery appears to significantly reduce both pre- and postdelivery emetic symptoms without apparent adverse effects on mother or neonate.

Adult↗
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Vertebral column length and spread of hyperbaric subarachnoid bupivacaine in the term parturient.

Patient height is considered an important determinant of the dose of spinal anesthesia. However, the relationship between body height and the level of sensory anesthesia with a fixed dose of spinal anesthetic has not been clearly documented. Recent evidence suggests no correlation between height or weight of parturients and spread of spinal anesthesia. Vertebral column length rather than body height may be more important in determining anesthetic spread. We studied the correlation between vertebral length measured from C7 to the level of the iliac crest (IC) and to the sacral hiatus (SH) and the sensory anesthetic level after the subarachnoid administration of 12 mg hyperbaric bupivacaine in term pregnant patients. There was no correlation between patient height, weight or body mass index and sensory anesthesia level. However, a significant correlation existed between vertebral length measured from C7 to IC (r = 0.32, p = 0.025) or to SH (r = 0.38, p = 0.006) and the level of anesthesia.

Anesthesia, Obstetrical↗
PubMedDate not supplied

Comparative effects of subarachnoid hyperbaric bupivacaine and tetracaine-procaine for cesarean delivery.

Hyperbaric solutions of 0.75% bupivacaine (8.25% dextrose), and 1% tetracaine mixed with an equal volume of 10% procaine were compared in a double-blind study of 22 parturients undergoing elective cesarean delivery and spinal anesthesia. The onset of sensory anesthesia and motor block was similar in the two groups. The maximal level of sensory anesthesia to pinprick was significantly higher after the use of the tetracaine-procaine mixture. The adequacy of anesthesia was similar in both groups as indicated by the lack of differences with regard to anesthetic supplementation between the groups. However, a significantly shorter duration of sensory anesthesia and motor blockade occurred in the group in which bupivacaine was employed. The incidence of hypotension was higher in those patients receiving the tetracaine-procaine mixture as indicated by the use of significantly higher total doses of ephedrine to maintain baseline blood pressure in this group. No differences in Apgar scores or blood gases were noted between the two groups of patients. This study suggests that hyperbaric 0.75% bupivacaine offers certain advantages over hyperbaric tetracaine-procaine when used in equal volumes for spinal anesthesia cesarean delivery.

Analgesia, Obstetrical↗
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Anesthesia for cesarean delivery in patients with herpes simplex virus type-2 infections.

Some concerns exist regarding the use of regional anesthesia for patients with active genital herpes simplex virus type-2 (HSV) infections undergoing cesarean delivery. Previous studies have reported the safe use of epidural anesthesia in these patients; there are no reports of the use of spinal anesthesia in this setting. We performed a 6-year retrospective survey of 169 patients delivered by cesarean delivery because of HSV infection. One hundred sixty-four of these patients had the diagnosis of secondary infection and five had the diagnosis of primary infection. Fifty-nine patients received general anesthesia, 75 received spinal anesthesia, and 35 received epidural anesthesia. One patient who was diagnosed with primary herpes and who received spinal anesthesia had a transient postpartum neurologic deficit; the etiology of this deficit was not clearly related to the anesthetic technique. No patients with secondary infection had septic or neurologic complications related to the anesthetic. Both spinal and epidural anesthesia appear to be safe alternatives for patients with secondary HSV infections undergoing cesarean delivery.

Anesthesia, Epidural↗
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Precordial Doppler monitoring and pulse oximetry during cesarean delivery: detection of venous air embolism.

Venous air embolism (VAE) is a potential but rare complication of cesarean delivery that can be associated with morbidity and death. Uterine sinuses are susceptible to the entrance of air during cesarean delivery. To define the incidence of VAE and its relation to arterial oxygen saturation (SaO2) and consequent electrocardiographic (ECG) changes, a prospective study was undertaken in which precordial Doppler monitoring was conducted during cesarean delivery. Concomitant, SaO2 and ECG were recorded in 78 patients. Fifty-one of 78 (65%) of the subjects had Doppler changes consistent with VAE. Of these, 37 patients (72%) showed a decreased SaO2, (average decline 5.2%). The remainder of the patients with Doppler changes showed no SaO2 change. Twenty of the patients with Doppler changes and decreased SaO2 complained of chest pain and dyspnea. Three of these patients exhibited ECG changes including ST segment depression. Although all ECG changes resolved spontaneously without sequelae, the potential clearly existed for life threatening embolic events. Thus, precordial Doppler monitoring of cesarean delivery patients demonstrated a surprisingly high incidence of Doppler changes consistent with VAE. Some episodes were associated with a significant reduction in SaO2 and rarely with ECG changes.

Cesarean Section↗
PubMedDate not supplied

pH adjustment of local anesthetic solutions with sodium bicarbonate: laboratory evaluation of alkalinization and precipitation.

pH adjustment of several commonly administered local anesthetic solutions was evaluated in the laboratory. The pH achieved after the addition of sodium bicarbonate and the onset of precipitation for alkalinized solutions were recorded. Solutions of 2-chloroprocaine and lidocaine readily alkalinized to near physiological pH without precipitation. Mepivacaine solutions exhibited a tendency for delayed precipitation (18-20-minute latency for 1.5% mepivacaine) above neutral pH. Bupivacaine and etidocaine solutions precipitated after the addition of small amounts of sodium bicarbonate and could not be alkalinized to physiologic pH. Two commercially available sodium bicarbonate preparations, 4% (wt/vol) and 8.4% (wt/vol), were compared and produced similar pH changes and precipitation behavior. The data obtained for pH and time to precipitation for local anesthetic solutions alkalinized with sodium bicarbonate may be useful for practical application in the clinical setting.

Anesthetics, Local↗
PubMedDate not supplied

Single neuronal activities from CA3 region of hippocampus during conditioning, in mobile unanaesthetised conscious rabbits.

Single neuronal activities of 93 units from CA3 region of hippocampus were studied in unanaesthetised mobile rabbits. Effects of repeated reinforced conditioned stimuli (CS+) were observed on these neuronal firing pattern. The conditioned stimuli (CS) consisted of a tone 600 Hz for 6 seconds which was reinforced by a subcutaneous electrical shock (0.4 V, frequency 250 sec, and pulse width 300 microsec) for one second duration (CS+). Ten such CS+ were applied at the gap of 5 min, in between. As majority of CA3 neurons showed irregular spontaneous activities-the histograms drawn after calculation of interspike intervals showed a definite pattern of discharge which could be compared before, during and after multiple CS+. Two groups of neurons could be identified by their resting firing pattern. One group consisting of 21 neurons (22.5% approximately) showed complex spikes, with spike frequency less than 2 to 8 per sec. They were complex spike cells (CSC). The other group consisting of majority of neurons (72 neurons, 77.5% approximately) showed comparatively high spike frequency greater than 8 to 40 per sec (theta cells). Both the group of neurons reacted tonically to CS+. All complex spike cells and 54% of theta cells showed inhibitory reaction and 46% of theta cells showed excitatory reaction to CS+. But with repeated presentation (4th to 5th) of CS+ the reaction gradually declined and finally after tenth CS+ it disappeared and resting firing pattern was observed. Thus it seems that the neurons of CA3 region have an intrinsic habituation capability. The probable cause, mechanism and the significance for the habituation has been discussed here.

Animals↗
PubMedDate not supplied

Purification and characterization of fish surface mucin.

Fish surface mucin from Pampus argenteus was extracted with different organic solvents and the residue passed through Sephadex G-200. The major peak was purified by DEAE-Cellulose chromatography and five fractions were obtained. Carbohydrate and protein contents showed that major peak is a glycoprotein. Rechromatography of this component on the Sephadex G-200 column gave a single peak, with an estimated minimal molecular weight of 6.9 X 10(5). Analysis of individual sugar components revealed the presence of galactose, glucose, mannose, arabinose, N-acetyl glucosamine, N-acetyl galactosamine and sialic acid. The most represented amino acids are threonine, serine, proline, glutamic acid and glycine. The N-terminal amino acid end was blocked. Nearly 47% of sulphate was acid labile. Sialic acid and fucose were released rapidly by mild acid hydrolysis. The presence of blood group-A activity suggests that some kind of terminal alpha-Gal-NAC may be present.

Amino Acids↗