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Biomedical subjects

S K Sanyal

Publications and source records attributed to S K Sanyal.

At least 19 recordsLinked to original sources
PubMed2006

Preparation of prospective plant oil derived micro-emulsion vehicles for drug delivery.

Biocompatible oil-in-water (o/w) micro-emulsions can be prospective drug delivery vehicles for their capability to solubilize lipophilic (oil soluble) drugs in the dispersed oil. Plant oils are considered suitable for such a purpose. In this study, we have attempted to examine the dispersion of corn, cottonseed, clove, orange and peppermint oils, as well as isopropyl myristate (IPM) in water continuum in presence of surfactants Tween-20, Brij-30 and Brij-92 and co-surfactants ethanol (EtOH) and isopropyl alcohol (iPrOH). Both ternary (oil/surfactant/water) and psedoternary (oil/surfactant + co-surfactant/water) phase diagrams were constructed. The ternary systems produced larger micro-emulsion forming zones than the psedo-ternary systems. The combinations peppermint oil/iPrOH/water, IPM/iPrOH/water and 1:1 (v/v) peppermint oil + IPM/iPrOH/water were found to form fair proportion of single-phase surfactant-less micro-emulsion. The surfactant-aided ternary systems produced larger clear microemulsion zones, compared to pseudo-ternary systems, while the behaviour of surfactant-less systems was intermediate. The prepared systems had shelf life of 1 year and they withstood temperature variations in the range of 4-40 degrees C.

2-Propanol↗
PubMed2002

Studies on surfactant-biopolymer interaction. I. Microcalorimetric investigation on the interaction of cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) with gelatin (Gn), lysozyme (Lz) and deoxyribonucleic acid (DNA).

The interaction of the surfactants cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) with the biopolymers gelatin (Gn), lysozyme (Lz) and deoxyribonucleic acid (DNA) was studied by isothermal titration microcalorimetry at varied biopolymer concentration, pH and temperature. The nature of interaction of the surfactants with the biopolymers was assessed from the observed enthalpy-[surfactant] profiles. The biopolymer-induced aggregation of the surfactants was observed. The enthalpies of aggregation of amphiphiles, binding of aggregates with macromolecules, organisational change of bound aggregates, and threshold concentrations for micelle formation of surfactants in the presence of biopolymers were estimated. The results collected on the three biopolymers were analysed and compared.

Biopolymers↗
PubMed2002

Physicochemical investigations of microemulsification of coconut oil and water using polyoxyethylene 2-cetyl ether (Brij 52) and isopropanol or ethanol.

The microemulsification of coconut oil/polyoxyethylene 2-cetyl ether/2-propanol or ethanol/water was investigated. The phase behaviors of the mixed system were examined. The shear viscosity at different temperatures was measured to derive activation parameters for the viscous flow. The diffusion coefficient of the microemulsions at different compositions was determined by the DLS method. The energetics of solubilization of water into oil + Brij + alkanol as well as of oil into water + Brij + alkanol forming w/o and o/w microemulsions, respectively, were calorimetrically determined.

Journal Article↗
PubMed2001

Physicochemical investigations on microemulsification of eucalyptol and water in presence of polyoxyethylene (4) lauryl ether (Brij-30) and ethanol.

The microemulsification of eucalyptol/polyoxyethylene(4)lauryl ether (Brij-30)/ethanol/water has been investigated. The phase behaviours of the mixed system in pseudoternary and tetrahedral representations have been examined to understand the topological nature of the multicomponent mixtures. Phase volumes of the heterogeneous combinations have been estimated to understand the mixing efficacy of the combinations. Shear viscosities of different monophasic compositions have been measured at different shear rates and temperatures, and the activation parameters for the viscous flow have been evaluated. The dimensions of the nanodispersions of w/o and o/w types, their diffusion coefficients and the polydispersity have been determined by the DLS method. The energetics of solubilisation (dissolution) of water in oil+Brij-30+ethanol as well as oil in water+Brij-30+ethanol forming w/o and o/w microemulsions, respectively, have been calorimetrically determined. Considering the phase separation point to be the point of maximum solubility, the energetic parameters (enthalpy, free energy and entropy) of the microemulsification process have been estimated.

Calorimetry↗
PubMed1995

First case of human infection caused by Pasteurella gallinarum causing infective endocarditis in an adolescent 10 years after surgical correction for truncus arteriosus.

OBJECTIVE: To report the first case of human infection (infective endocarditis [IE]) caused by Pasteurella gallinarum and to review the literature regarding IE caused by the genus Pasteurella. SETTING: University hospital based. PATIENT: An adolescent boy who underwent successful correction for truncus arteriosus 10 years before the present illness. RESULTS: Persistent fever, pallor, and a palpable spleen suggested IE clinically. Echocardiography documented vegetation in the conduit that was used for surgical correction. Blood cultures grew P. gallinarum and confirmed its role as the causative organism for IE in the patient. CONCLUSION: This case illustrates that IE may develop in a child with congenital heart disease several years after surgical intervention using material that is foreign to the body (conduit), and that such a complication may involve unusual pathogens. These observations emphasize the need for careful long-term follow-up of children with congenital heart disease even after successful surgical correction.

Bacterial Typing Techniques↗
PubMed1994

Sequential changes in vital signs and acid-base and blood-gas profiles in Pneumocystis carinii pneumonitis in children with cancer. Basis for a scoring system to identify patients who will require ventilatory support.

Early reliable identification of patients with Pneumocystis carinii pneumonia (PCP) who will require ventilatory support would be desirable. To develop a predictive system to meet this need, we studied, prospectively, the sequential alterations in vital signs and acid-base and blood-gas profiles associated with this disease in 55 children with cancer, 29 of whom did not require ventilatory support (Group I) and 26 who did (Group II). None of the patients had acquired immunodeficiency syndrome (AIDS). On admission to the hospital the only feature that distinguished patients in Group I from those in Group II was the mean (+/- SD) respiratory rate (38.7 +/- 2.1 versus 49.1 +/- 3.5 breaths/min, p < 0.02). By 12 h after admission there was a significant difference in the partial pressure of oxygen (PaO2) between Groups I and II (75.1 +/- 3.2 mg Hg versus 65.4 +/- 3.1 mm Hg, p < 0.05), and also in the two groups' inspired fraction of oxygen (FIO2; 24.9 +/- 0.54% versus 29.6 +/- 1.6%, p < 0.01). Both alterations, as well as tachypnea, persisted for the remainder of the study period. The maximum FIO2 did not exceed 45% in Group I, and by 60 h after admission to the hospital, all patients in this group had persistent increases in PaO2 that exceeded 80 mm Hg, permitting decreases in FIO2 to that of room air. In Group II, hypoxemia was refractory despite an increase in FIO2 to 50%, at which point ventilatory support was begun (at a mean of 81.1 +/- 32.3 h after admission).(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1991

Anaesthetic-induced ventricular tachyarrhythmia in Jervell and Lange-Nielsen syndrome.

A four-year-old deaf girl with a history of convulsions developed polymorphous ventricular tachycardia during induction of anaesthesia. The arrhythmia reverted to sinus rhythm spontaneously. Post-anaesthetic ECG showed marked prolongation of the QTc interval (570-690 msec). Deafness and prolonged QTc interval in association with microcytic-hypochromic anaemia confirmed the diagnosis of the Jervell and Lange-Nielsen syndrome. This case report highlights the potentially lethal complication of halothane anaesthesia in patients with long QTc interval syndrome.

Anesthesia, Inhalation↗
PubMed1983

Fatal congestive heart failure following mitoxantrone treatment in two children previously treated with doxorubicin and cisplatin.

Two children, who had received chemotherapy with doxorubicin and cisplatin for disseminated chondrosarcoma and recurrent rhabdomyosarcoma, developed congestive heart failure following treatment with mitoxantrone (DHAD); the total doses of DHAD were 128 and 90 mg/m2, respectively. The patient with chondrosarcoma had relief of his cardiac symptoms with digitalis and furosemide. The patient with rhabdomyosarcoma, whose tumor responded following treatment with DHAD, died 2 weeks after development of congestive heart failure. For patients who have received prior treatment with potentially cardiotoxic agents, administration of DHAD should be followed by careful monitoring of cardiac function.

Anthraquinones↗
PubMed1982

Sequelae of the initial attack of acute rheumatic fever in children from north India. A prospective 5-year follow-up study.

We determined the outcome of acute rheumatic fever in 85 children from North India who had received regular antistreptococcal prophylaxis after their first attack. By the end of the 5-year follow-up, 33 patients had rheumatic heart disease. Mitral insufficiency, the most common valvular lesion, appeared in 91% of the patients, whereas mitral stenosis developed in only 18%. Initial carditis, congestive heart failure, cardiomegaly or moderate-to-severe mitral insufficiency significantly increased the risk of rheumatic heart disease (p less than 0.001). The recurrence rate of acute rheumatic fever in children who received continuous prophylaxis was 0.006 per patient-year. Most recurrence (92%) mimicked the first attack and produced further cardiac damage in five patients with carditis and in one patient with chorea. Cardiac status during the first attack of rheumatic fever and the continuity of prophylaxis were the major determinants of outcome. Statistical comparisons disclosed that with continuous prophylaxis, the prevalence rate, evolution and clinical spectrum of the sequelae of acute rheumatic fever in children from India do not differ significantly from those in the West.

Child↗
PubMed1982

Systolic time interval characteristics in children with Duchenne's progressive muscular dystrophy.

Systolic time interval (STI) characteristics of 17 boys with Duchenne's muscular dystrophy (DMD) were compared with those of 80 normal boys who served as control subjects. The heart rate decreased linearly with age in normal control subjects (r = -.47, P less than .01). By contrast, heart rate was significantly higher in patients with DMD (P less than .001) and tended to increase further with age. Each STI variable for normal control subjects increased significantly with age (P less than or equal to .01); QII, left ventricular ejection time (LVET), and pre-ejection period (PEP), in addition, decreased with increasing heart rate (P less than or equal to .05). In dystrophic patients QII and LVET decreased with increasing heart rate (P less than .001) but were not influenced by age. None of the other STI values in dystrophic patients was significantly influenced by either age or heart rate. Mean QII, LVET, and QI were shorter and PEP, isometric contraction time (ICT), and PEP/LVET ratio were longer (P less than .001) for DMD patients than for normal control subjects. In 13/17 patients, QII and LVET were below the 95% confidence interval of the normal mean, whereas PEP, ICT, and PEP/LVET exceeded the upper limits of normal in 8, 9 and 11 patients, respectively. For dystrophic patients, the difference (delta) between the observed values and those predicted from regression equations for normal control subjects was lower for QII, LVET, and QI (P less than .01) but higher for PEP (P less than .04), ICT, and PEP/LVET ratio (P less than .001). delta QII and delta LVET increased with age (P = .001 and .032, respectively). Duchenne's muscular dystrophy is thus documented to be associated with substantial alterations in STI characteristics that suggest a compromise of global left ventricular performance. Some of these abnormalities increase with age, probably reflecting the progressive cardiomyopathy characteristics of this disease.

Adolescent↗
PubMed1981

Course of pulmonary dysfunction in children surviving Pneumocystis carinii pneumonitis. A prospective study.

Pulmonary function studies were done serially in 23 children 7 to 18 yrs of age who had survived the acute stage of Pneumocystis carinii pneumonitis. Each child was asymptomatic. Spirometric indices, expiratory flows, pulmonary gas transfer factor, arterial blood gases, and other clinical variables were assessed a few days before patients were discharged from the hospital and at 1-, 3-, 6-, and 12-month intervals thereafter; two patients developed recurrent pneumonitis during follow-up and were studied twice. All but five subjects had pulmonary dysfunction when tested initially. A decrease in pulmonary gas transfer factor, observed in 17 studies, was the most common abnormality. Restrictive pulmonary disease was seen in 11 studies; an obstructive component, in one. Arterial hypoxemia at rest, while patients were breathing room air, was noted in nine cases. Roentgenographic evidence of bilateral diffuse lung opacities was seen in 11 patients and was positively correlated with decreases in pulmonary gas transfer factor (p less than 0.001). Arterial hypoxemia was significantly related to intrapulmonary right-to-left shunt (p less than 0.001) but not to decreases in pulmonary gas transfer factor, indicating the importance of ventilation-perfusion abnormalities in these patients. Serial follow-up studies disclosed significant improvement in pulmonary function deficits within 1 month and complete resolution by 6 months in all survivors. Recovery was not related to the amount of duration of O2 therapy, to the need for ventilatory support, or to chest roentgenographic abnormalities. Histopathologic findings in nine patients who died during follow-up did not indicate any residual interstitial fibrosis, collagen deposits, or alveolopathy. We conclude that Pneumocystis carinii pneumonitis during childhood does not typically produce long-lasting pulmonary sequelae.

Adolescent↗