PubMed Health⌕ Search

Biomedical subjects

A De

Publications and source records attributed to A De.

At least 19 recordsLinked to original sources
PubMed2006

A clinico-serological study of neurocysticercosis in patients with ring enhancing lesions in CT scan of brain.

AIMS OF THE STUDY: To study the clinical profile of neurocysticercosis and the utility of serological test using enzyme linked immunosorbent assay (ELISA) in patients with ring enhancing lesions in CT scan of brain. METHODS: A total of 51 patients presenting between April 2003 to March 2004 to the Assam Medical College and Hospital, Dibrugarh, with ring enhancing lesions in CT scan of brain suggestive of neurocysticercosis were included in the study. Serum samples for ELISA test were taken from all patients and controlled sera were taken from 20 patients admitted in the ward, who did not have clinical evidence of cysticercosis and whose CT scan of brain were either normal or revealed lesion other than cerebral cysticercosis. RESULTS: The maximum incidence of neurocysticercosis was found in the age group between 21 and 30 years (43.41%). Seizures were the commonest clinical presentation (100%). Eleven patients (21.56%) had ring enhancing lesions with central scolex. Fourty patients (78.44%) showed only ring enhancing lesions. ELISA test for definitive neurocysticercosis showed a sensitivity of 82.60% and specificity of 100%, while patients with CT scan features of neurocysticercosis had a sensitivity of 78.43% with ELISA. CONCLUSION: ELISA for cysticercosis showed a sensitivity of 82.60% and specificity of 100%. The study also shows that therapeutic effectiveness with albendazole is quite satisfactory. As the study population is small in number which was conducted in a span of one year, an evaluation with a larger number of patients will definitely throw more light on the subject.

Adult↗
PubMed2005

AT4 receptor activation increases intracellular calcium influx and induces a non-N-methyl-D-aspartate dependent form of long-term potentiation.

The angiotensin 4 receptor (AT4) subtype is heavily distributed in the dentate gyrus and CA1-CA3 subfields of the hippocampus. Neuronal pathways connecting these subfields are believed to be activated during learning and memory processing. ur laboratory previously demonstrated that application of the AT4 agonist, Norleucine1-angiotensin IV, enhanced baseline synaptic transmission and long-term potentiation, whereas perfusion with the AT4 antagonist, Norleucine1-Leu3-psi(CH2-NH2)3-4-angiotensin IV disrupted long-term potentiation stabilization in area CA1. The objective of the present study was to identify the mechanism(s) responsible for Norleucine1-angiotensin IV-induced increase in hippocampal long-term potentiation. Hippocampal slices perfused with Norleucine1-angiotensin IV for 20 min revealed a notable increase in baseline responses in a non-reversible manner and were blocked by the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione disodium salt. Infusions of Norleucine1-angiotensin IV prior to, but not after theta burst stimulation, significantly enhanced long-term potentiation compared with control slices. Further, N-methyl-D-aspartate receptor-independent long-term potentiation could be induced by tetanization during the perfusion of Norleucine1-angiotensin IV in the presence of the N-methyl-D-aspartate antagonist, D,L-2-amino-5-phosphonovaleric acid. Blockade of select voltage dependent calcium channels significantly reduced Norleucine1-angiotensin IV-induced increase in baseline responses and subsequent long-term potentiation suggesting that AT4 receptor activation increases intracellular calcium levels via altering voltage dependent calcium channels and triggers an N-methyl-D-aspartate-independent form of long-term potentiation. In support of this notion the application of Nle1-angiotensin IV to cultured rat hippocampal neurons resulted in increased intracellular calcium derived exclusively from extracellular sources. Consistent with these observations Nle1-angiotensin IV was capable of augmenting the uptake of 45Ca2+ into rat hippocampal slices. Taken together, these data indicate that increased calcium influx through postsynaptic calcium channels contribute to Norleucine1-angiotensin IV-induced enhancement of long-term potentiation.

Animals↗
PubMed2005

Diagnostic role of stool culture & toxin detection in antibiotic associated diarrhoea due to Clostridium difficile in children.

BACKGROUND & OBJECTIVE: Mere diagnosis of Clostridium difficile by culture does not help in the diagnosis of antibiotic associated diarrhoeae (AAD) due to C. difficile. Detection of toxins A and B form the mainstay in the diagnosis of AAD due to C. difficile. This study was undertaken to find out the role of stool culture and toxin detection in the diagnosis of AAD due to C. difficile. As there are very few documented reports from India about AAD due to C. difficile in children in the age group of 5-12 yr, this age group was selected. METHODS: Faecal samples were collected from 250 hospitalized children in the age group of 5-12 yr who developed diarrhoea on receiving antibiotics for different medical problems for more than five days duration. Also faecal samples of 250 age and sex matched controls were collected. Culture for C. difficile was done on cycloserine cefoxitin fructose egg yolk agar (CCFA) and colonies were identified by standard laboratory techniques. ELISA for toxins A and B detection and tissue culture on HeLa cells for toxin B detection were also done. RESULTS: Overall positivity was 18 per cent in this study group compared to the controls (P<0.001). Maximum positive cases were in 5-8 yr age group (84.4%). Severe diarrhoea, liquid stool with mucus and blood, faecal leucocytes >5/high power field, altered flora and presence of Gram-positive bacilli with oval subterminal spores on Gram stain were sensitive predictors for diagnosis of AAD due to C. difficile. Amongst positive cases, 68.9 per cent responded to discontinuation of antibiotics and 31.1 per cent to metronidazole therapy. INTERPRETATION & CONCLUSION: C. difficile was an important pathogen responsible for antibiotic associated diarrhoea (AAD) in children of 5-12 yr age group. Conservative use of antibiotics would be beneficial to decrease the incidence of AAD.

Anti-Bacterial Agents↗
PubMed2004

Interleukin-1beta stimulates growth hormone-releasing hormone receptor mRNA expression in the rat hypothalamus in vitro and in vivo.

Changes in growth hormone-releasing hormone (GHRH), GHRH-receptor (R), somatostatin and interleukin (IL)-1beta mRNA levels were determined in fetal rat hypothalamic cultures after administration of IL-1beta (1, 10, 100 ng/ml, 2 h incubation), and in adult rat hypothalamus 5 h after intracerebroventricular injection of IL-1beta (2.5 and 25 ng). IL-1beta stimulated GHRH-R mRNA expression both in vitro (10 and 100 ng/ml) and in vivo (2.5 and 25 ng). Somatostatin mRNA was significantly stimulated and GHRH mRNA slightly reduced in vitro, while these mRNA species were not altered in vivo in response to IL-1beta. IL-1beta stimulated its own expression both in vitro (10 and 100 ng/ml) and in vivo (25 ng). IL-1beta-induced mRNA responses occurred 2 h after treatment in vitro (incubation times, 30 min to 6 h). IL-1beta also elicited slight GHRH releases in vitro. Up-regulation of hypothalamic GHRH-R by IL-1beta may explain previous findings suggesting that IL-1beta stimulates GHRH activity.

Animals↗
PubMed2003

Circular polarization beam splitter that uses frustrated total internal reflection by an embedded symmetric achiral multilayer coating.

A symmetric achiral trilayer structure, which consists of a high-index center layer sandwiched between two identical low-index films and embedded in a high-index prism, is designed to produce equal and opposite quarter-wave retardation in reflection and transmission and equal throughput for the p and s polarization at oblique incidence. Such a device splits a beam of incident linearly polarized light into two orthogonally circularly polarized components of equal power that travel in different directions. A visible (633-nm) design that operates at a 60 degree angle of incidence and an infrared (10.6-microm) 45 degree cube design are presented. The spectral and angular sensitivities of the device are also considered.

Journal Article↗
PubMed2003

Potentized Mercuric chloride and Nux vomica facilitate water permeability in erythrocytes of a fresh-water catfish Clarius batrachus under acute ethanol intoxication.

OBJECTIVES: The primary biomolecular target of a homeopathic potency is unknown. If it is a plasma membrane protein such as water-channel protein, the drug would alter water permeation in cells. Therefore, the objective is to see if potentized homeopathic drugs like Mercuric chloride 30c and Nux vomica 30c could alter permeation of water through the erythrocytes of a fresh water fish under acute ethanol intoxication. LOCATION: The work was carried out in the Zoology Laboratory of Visva Bharati University, Santiniketan, West Bengal, India. SUBJECT: Live freshwater catfish. DESIGN: Erythrocytes collected from fish with and without ethanol intoxication were incubated in distilled water at 30 degrees C for 30 minutes with Ethanol 30c (control), Merc cor 30c (test 1), and Nux vomica 30c (test 2). Merc cor 30c and Nux vom 30c were prepared by successive dilution of the respective mother tinctures with 90% ethanol (1:100) followed by sonication at 20 kHz for 30 seconds in 30 steps. Ethanol 30c was prepared in the same way from 90% ethanol diluted with 90% ethanol. In another experiment, fish were pretreated with Ethanol 30c and Nux vom 30c followed by ethanol injection at 2 g/kg of body weight. Then their erythrocytes were tested in vitro with the same potencies. After centrifugation of blood samples, fluid part was removed, erythrocyte pellets dried in a BioChemical Oxygen Demand (BOD; Atlas Surgical, New Delhi, India) incubator at 90 degrees C for 12 hours and intracellular water content measured. RESULTS: Red blood cells (RBCs) from ethanol-injected fish permeated more water than those from normal fish. Water permeation was enhanced with Merc cor 30c and Nux vom 30c. RBCs from fish pretreated with Nux vom 30c imbibed more water in in vitro treatments than those from fish pretreated with Ethanol 30c. CONCLUSION: Because water channel proteins or aquaporins are mainly responsible for water transport through the plasma membrane of RBCs, it is thought that potentized drugs interact with these proteins, thereby facilitating water influx in the cells.

Alcoholic Intoxication↗
PubMed2003

An observational study to detect leptospirosis in Mumbai, India, 2000.

BACKGROUND: Leptospirosis is relatively uncommon in children. Following torrential rains and flooding an outbreak of leptospirosis was suspected in Mumbai. AIMS: To investigate the possibility of an outbreak of leptospirosis and describe the clinical illness. METHODS: From 24 July to 14 September 2000, children with a history of abrupt onset of high fever (>39 degrees C), who presented to our hospital, were admitted and tested serologically for anti-Leptospira antibodies by a quantitative enzyme linked immunosorbent assay (ELISA) test. An IgM titre of more than 20U/ml confirmed the diagnosis of leptospirosis. Clinical features in the confirmed leptospirosis and leptospirosis negative groups were analysed. RESULTS: Of 53 children screened, 18 (34%) had leptospirosis. In all 18, the disease was anicteric and responded well to intravenous penicillin. Four clinical features present at the time of admission were significantly associated with leptospirosis: a history of contact with flood water (18/18 v 16/35), conjunctival suffusion (5/18 v 1/35), abdominal pain (9/18 v 5/35), and skin rash (5/18 v 1/35). As the number of these four features concomitantly present increased, the chances of the child having leptospirosis also increased significantly. A history of contact with flood water had a sensitivity of 100%, and the presence of conjunctival suffusion, abdominal pain, and skin rash had a specificity of 97%, 86%, and 97%, respectively, for identifying children with leptospirosis. CONCLUSION: Leptospirosis should be suspected in febrile children with contact with flood water.

Age Distribution↗
PubMed2003

Optimal beam splitters for the division-of-amplitude photopolarimeter.

Optimal optical parameters of the beam splitter that is used in the division-of-amplitude photopolarimeter are determined. These are (1) 50%-50% split ratio of the all-dielectric beam splitter, (2) differential phase shifts in reflection and transmission delta(r) and delta(t) that differ by +/- pi/2, and (3) ellipsometric parameters (psi(r), psi(t)) = (27.368 degrees, 62.632 degrees) or (62.632 degrees, 27.368 degrees). It is also shown that for any nonabsorbing beam splitter that splits incident unpolarized light equally, the relationship psi(r) + psi(t) = pi/2 is always satisfied.

Journal Article↗
PubMed2002

Potentized Mercuric chloride and Mercuric iodide enhance alpha-amylase activity in vitro.

Mercuric chloride 30c and Mercuric iodide 30c were prepared by successive dilution in 30 steps of 1:100 followed by sonication at 20KHz for 30s at each step. Both were prepared in two media: 90% ethanol and distilled water. Three preparations of Mercuric chloride 30 in water were used: 12-month old, 1-month old and 4-day old. The controls for the water and ethanol-water preparations were pure water 30c and 90% ethanol 30c, respectively. For the three water preparations there were three matched controls of water 30c of the same ages. Each potentized substance or its control was mixed with distilled water 1:100 before testing. Hydrolysis of starch by alpha-amylase was measured by the standard procedure after incubation for 15 min at 27 degrees C. Mercuric chloride 30c and Mercuric iodide 30c in both water and aqueous ethanol media, enhanced enzyme activity significantly, compared to their respective controls. Mercuric chloride 30c, prepared in water 12 months previously, produced no significant change in the enzyme activity compared to its control. We hypothesize that the structure of the active molecule imprinted on water polymers during the process of dynamization. The specifically structured water interacts with the active sites of alpha-amylase, modifying its activity. Ethanol molecules have large non-polar part stabilizing the water structure and thus retaining activity for a longer time.

Disinfectants↗
PubMed2001

Heat shock protein 27 inhibits apoptosis in human neutrophils.

BACKGROUND: Prolonged neutrophil(PMN) survival has been implicated in tissue injury following sepsis. A variety of bacterial products have been identified which inhibit PMN apoptosis including lipopolysaccharide(LPS). Extracellular heat shock proteins(Hsp) have recently been identified as potent regulatory signals for the innate immune system during the inflammatory response. We hypothesized that Hsp 27 can affect PMN phenotype with respect to apoptosis and cytokine profile. MATERIALS AND METHODS: PMN were isolated from the peripheral blood of healthy human volunteers by red blood cell sedimentation and gradient centrifugation. Cells were placed in media and cultured for 18 h with and without recombinant human Hsp 27 at various concentrations. In parallel experiments, PMN were stimulated with LPS, a known inhibitor of PMN apoptosis, for comparison. Apoptosis was quantified using annexin V and propidium iodide staining with flow cytometric analysis. Culture supernatants were assayed for secretion of TNF-alpha, IL-10, and IL-12. RESULTS: Hsp 27 significantly inhibits PMN apoptosis [control; 81.8 +/- 3.6%, vs Hsp 27, 60.4 +/- 4.1% p < 0.05]. The reduction is similar to that signaled by LPS, alone. Together their effect is not synergistic. The Hsp 27 response is dose-dependent. Hsp 27 does not induce secretion of TNF-alpha, IL-10, or IL-12, whereas LPS does signal IL-12 and TNF-alpha secretion. CONCLUSION: These data demonstrate that exogenous Hsp 27 may play a role in neutrophil-mediated tissue injury during trauma and sepsis via its ability to inhibit neutrophil apoptosis. However, Hsp 27 does not significantly alter neutrophil phenotype with respect to cytokine production profile.

Apoptosis↗
PubMed2001

Loss of chemokine SDF-1alpha-mediated CXCR4 signalling and receptor internalization in human hepatoma cell line HepG2.

Expression of the chemokine stromal cell-derived factor-1alpha (SDF-1alpha) is absent from many carcinomas, including hepatomas. We note an early signalling defect in the hepatocellular carcinoma (HCC) cell line HepG2 that expresses the CXCR4 receptor and binds biotin-labelled SDF, but fails to stimulate downstream signalling events after engagement with SDF. In HepG2, the SDF/CXCR4 interaction did not result in calcium influx, phosphorylation and internalization of CXCR4, nor in a rapid phosphorylation of p44/42 MAP kinase. There were no CXCR4 mutations in the second chemokine binding loop or C terminal phosphorylation and internalization domains. The downstream signalling machinery in HepG2 appears to be intact since transfection of wild-type CXCR4 restored functional responsiveness. We conclude that HepG2 is unresponsive to SDF stimulation because of a defect located after receptor binding but before the activation of the signalling cascade. A hypothetical blocking molecule could hinder receptor internalization or CXCR4 signalling.

Carcinoma, Hepatocellular↗
PubMed2001

Synthesis and studies on spectroscopic as well as electron donating properties of the two alkoxy benzo[b]thiophenes.

Synthesis, characterization, steady state and time resolved, using time correlated single photon counting as well as laser flash photolysis techniques, spectroscopic investigations were made for two alkoxy benzo[b]thiophene molecules: 5-methoxy benzo[b]thiophene (5MBT) and 5-methoxymethyl benzo[b]thiophene (5MMBT). In both non-polar n-heptane (NH) and polar acetonitrile (ACN) solvents and at ambient temperature the electronic absorption spectra of these thiophenes exhibit different band systems whose assignments were made from the measurements of the steady state excitation polarization spectra. Steady state fluorescence spectra of these molecules in the different polarity solvents show the presence of non-specific interactions. From the redox properties of the benzothiophenes, measured by cyclic voltammetry, their electron donating properties were observed in the presence of the well-known electron acceptor 9cyanoanthracene (9CNA). Further, detailed studies by laser flash photolysis techniques show that ion-recombination mechanism predominates after the initial excitation of the acceptor moiety using the third harmonic of Nd:YAG laser. This recombination together with the external heavy atom effect (the donor containing 'sulphur' atom) appears to be responsible for the formation of the triplet of the monomeric acceptor 9CNA. From the steady state experiments it is shown that both in non-polar NH and highly polar ACN the quenching in the fluorescence emission of 9CNA in the presence of the benzothiophene donors is brought about primarily by the external heavy atom effect and in ACN, although the presence of the photoinduced ET reaction is confirmed, this process seems, from the observed bimolecular dynamic quenching rate, kq to be significantly masked by the external heavy atom effect.

Acetonitriles↗
PubMed2001

Effect of antisense suppression of transforming growth factor-beta3 gene on lactotropic cell proliferation.

The mechanism by which oestrogen regulates lactotropic cell proliferation is not well understood. Recently it has been shown that a transforming growth factor beta (TGF-beta) gene-related peptide, TGF-beta3, is produced in the lactotropes and stimulates lactotropic cell proliferation in vitro. In this study, the role of this growth factor in oestrogen-induced lactotropic cell proliferation was determined in vitro using oligonucleotide designed to inhibit TGF-beta3 gene expression. We used the oligonucleotide in an antisense orientation, which is complementary to regions in the TGF-beta3 message. Oligonucleotides in sense and missense orientation were also used. We found that the antisense sequence that was effectively incorporated into pituitary cells produced a marked inhibition of the stimulatory action of oestrogen on lactotropic cell proliferation. Sense and missense oligonucleotides produced no significant effects on oestrogen-stimulated lactotropic cell proliferation. The growth-inhibitory effect of antisense oligonucleotide was blocked by TGF-beta3 peptide. These results suggest that TGF-beta3 may be involved in the processes that mediate oestrogen-regulated lactotropic cell proliferation.

Animals↗
PubMed2001

Nux vomica 30 prepared with and without succession shows antialcoholic effect on toads and distinctive molecular association.

Adult toads, Bufo melanostictus, were administered Nux vomica (Nux v) 30 prepared with and without succussion on the tongue. The drug was mixed with sterile distilled water at the rate 0.05ml/ml water and given orally 0.05ml/individual. The control consisted of blank ethanol solution. Seeds of Strychnos nuxvomica were ground and extracted with 90% ethanol in the laboratory. Nux v 30 was prepared by successive dilution and succussion in 30 steps, Nux v 30 u was prepared by successive dilution only. Four hours after treatment, toads were given 25% ethanol i.p. at 8g/kg body weight. The duration of ethanol induced sleep time was recorded for each toad. Both Nux v 30 and Nux v 30 u significantly reduced ethanol induced sleep time in toads as compared to their respective controls. Electronic, infra red and nuclear magnetic resonance spectra of Nux v 30, Nux v 30 u and their diluent medium (90% ethanol) show marked differences from each other. These dilutions and ethanol 30 and ethanol 30 u show marked differences from each other with respect to spin-lattice relaxation time (T1) and chemical shift. The difference has been attributed to the variation in intra and inter-molecular association of ethanol and water.

Administration, Oral↗
PubMed2001

Ceftriaxone therapy in ciprofloxacin treatment failure typhoid fever in children.

BACKGROUND & OBJECTIVES: The rapid spread of multidrug resistant (MDR) typhoid fever has posed a great challenge for the treatment of these cases the world over. After the emergence of chloramphenicol resistant Salmonella typhi strains, ciprofloxacin has become the drug of choice for the treatment of typhoid fever even in the paediatric age group. This study evaluated the role of ceftriaxone therapy in bacteriologically confirmed MDR typhoid cases who did not respond to 12-14 days of ciprofloxacin therapy. Attempts have also been made to investigate the in vitro susceptibility of isolated S. typhi strains to chloramphenicol, ciprofloxacin and ceftriaxone. METHODS: A total of 140 children, aged 3-10 yr, clinically diagnosed as having typhoid fever, without any clinical response after 12-14 days of ciprofloxacin therapy were screened for S. typhi by blood culture. In the bacteriologically positive children the treatment was changed to intravenous ceftriaxone for 14 days. The isolated strains of S. typhi were tested for in vitro antimicrobial susceptibility. RESULTS: Clinical and bacteriological cure was observed with intravenous ceftriaxone therapy in all the 32 bacteriologically positive patients. All isolated S. typhi strains were uniformly (100%) susceptible to ciprofloxacin and ceftriaxone but 50 per cent of the strains were resistant to chloramphenicol. The MIC values of chloramphenicol, ciprofloxacin and ceftriaxone ranged between 125-500, 0.0625-0.5 and < 0.0625 microgram/ml respectively. INTERPRETATION & CONCLUSION: The study indicates that although the S. typhi strains were susceptible to ciprofloxacin in vitro, the patients did not respond clinically and bacteriologically to ciprofloxacin therapy. Hence, ciprofloxacin may not represent a reliable and useful option for treating MDR typhoid fever; ceftriaxone may be an effective alternative for the treatment of such cases.

Anti-Infective Agents↗