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Biomedical subjects

R Jain

Publications and source records attributed to R Jain.

At least 19 recordsLinked to original sources
PubMed2003

Photocatalytic degradation of 2-chlorophenol: a study of kinetics, intermediates and biodegradability.

The kinetics of photocatalytic (TiO(2)/UV) degradation of 2-chlorophenol (2-CP), characterization of intermediates and induction of biodegradability in treated chlorophenol solutions is reported. Approximately 95% of the 2-CP is removed in approximately 2h at pH 5 and 0.2g TiO(2)l(-1) when the 2-CP concentration is < or =100mgl(-1); the pseudo-first-order rate constant (k) is estimated to be 0.0183 min(-1). GC-MS analyses detected phenol, catechol, hydroxyhydroquinone (HHQ), and chlorohydroquinone (CHQ) intermediates during the short irradiation time (<1h); however two other higher carbon intermediates 2-hydroxy-benzaldehyde (HB) and [1.1'-biphenyl]-2,2'-diol (BPD) are found as major intermediates over longer irradiation times. The biochemical oxygen demand (BOD) of treated 2-CP solutions improved substantially. A tentative mechanistic pathway to explain formation of higher carbon intermediates is presented.

Biodegradation, Environmental↗
PubMed2003

A genetic algorithm based nearest neighbor classification to breast cancer diagnosis.

This paper presents an application of a hybrid approach (the genetic algorithms and the k-nearest neighbour) proposed by Ishbuchi to Wisconsin breast cancer data. For the diagnosis of breast cancer, the determination of the presence of benign/malignant breast tumors represents a very complex problem (even for an experienced cytologist). Therefore the automatic classification of benign and malignant symptoms is highly desirable as a valuable aid to assist oncologists in the decision making of the diagnosis of breast cancer. In this paper, the genetic algorithm based k-nearest neighbour method for classification of benign and malignant breast tumors is presented. The genetic-algorithm (GA) is used for finding a compact reference set by selecting a small number of reference patterns from a large number of training patterns in nearest neighbor classification. The GA simultaneously performs feature selection and pattern selection and prunes unnecessary features. The goal is to maximize the classification performance of the reference set and minimize the number of selected patterns and features. Results are also compared with a fuzzy-genetic approach where each reference patten represents a fuzzy if-then rule with a circular-cone-type membership function.

Algorithms↗
PubMed2003

Cochlear implant failure: imaging evaluation of the electrode course.

Cochlear implant (CI) is an electronic device used to rehabilitate patients with sensorineural hearing loss. The intent of this review is to demonstrate the normal position of the electrode on computed tomography (CT) and contrast this with various examples of the electrode malpositioning. Post-implantation CT is performed to localize the cause of implant failure in patients in which radiographs suggest an anomalous course of the electrode. A common cause of device failure is extrusion or malpositioning of the electrode. It is important for the radiologists to recognize this important aspect of device failure. Post-implant CT can help identify patients with malpositioned electrode in whom another attempt can be made by correctly re-implanting the electrode.

Cochlea↗
PubMed2003

Hepatocyte dysfunction and hepatic encephalopathy in Plasmodium falciparum malaria.

BACKGROUND: According to the WHO, signs of hepatic dysfunction are unusual, and hepatic encephalopathy is never seen in malaria. However, in recent years, isolated cases have been reported from different parts of world. AIM: To identify the evidence for hepatocyte dysfunction and/or encephalopathy in jaundiced patients with falciparum malaria. DESIGN: Prospective observational study. METHODS: We studied 86 adult patients of both sexes who had malaria with jaundice (serum bilirubin > 3 mg%). The main outcome measures were: flapping tremor, deranged psychometric test, level of consciousness, serum bilirubin level, serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, blood ammonia level, viral markers for hepatitis, ultrasonography of liver and gall bladder and electroencephalography (EEG). RESULTS: The range of serum bilirubin was 3-48.2 mg% (mean +/- SD 10.44 +/- 8.71 mg%). The ranges of AST and ALT levels were 40-1120 IU/l (294.47 +/- 250.67 IU/l) and 40-1245 IU/l (371.12 +/- 296.76 IU/l), respectively. Evidence of hepatic encephalopathy was seen in 15 patients. Asterexis was observed in 9 patients, impaired psychometric tests in 12 and altered mental state in 13. Arterial blood ammonia level was 120-427 meq/l (310 +/- 98.39 meq/l). EEG findings included presence of large bilateral synchronous slow waves, pseudo burst suppression and triphasic waves. Four patients died due to multiple organ dysfunction; the others made rapid recoveries. DISCUSSION: There is strong evidence of hepatocyte dysfunction and hepatic encephalopathy in some of these patients, with no obvious non-malarial explanation. Current guidelines may need to be revised.

Adult↗
PubMed2003

Pulmonary manifestations in brucellosis: a report on seven cases from Bikaner (north-west India).

OBJECTIVES: Pulmonary manifestations of Brucellosis are rare. We came across seven patients with predominant symptomatology of pulmonary involvement amongst 98 patients of active brucellosis seen in last four years. MATERIAL AND METHODS: The study is related to patients of brucellosis whose principal presenting features were related to respiratory symptom (cough, expectoration, pain in chest and breathlessness) along with fever and other constitutional symptoms. It included seven patients amongst 98 patients of active brucellosis seen during June 1996 to Feb. 2000 at PBM Hospital Bikaner. Diagnosis was confirmed by demonstration of the raised brucella agglutination titre of 1:320 or more in the serum. All patients were treated with rifampicin 900 mg daily and doxycyclin 100 mg twice daily for six week. The treatment was extended for another four weeks in two patients because of persistence of skiagram abnormalities. RESULT: Three patients had abnormality in skiagram chest in the form of pleural effusion, multiple paranchymal opacities and pneumonia. The skiagram chest was normal in remaining four patients. The response of treatment started with 10-15 days and all the patients became symptom-free at the end of six weeks except one patient. Skiagram chest at this time was normal in patients of pleural effusion but there was persistence of haziness and few opacities in other two patients. Follow up skiagram chest at the end of six months and twelve months was normal in all patients except calcified opacity in one patient. There was no evidence of relapse in any patient at the end of one year follow up. Liver function tests remained within normal range and no drug toxicity was observed. CONCLUSION: Pulmonary manifestations of brucellosis are rare. Treatment with rifampicin and doxycylin showed marked clinical and radiological improvement. All patients were completely disease-free at the end of one year follow up.

Adolescent↗
PubMed2002

Naegleria meningitis: a rare survival.

Acute amebic meningoencephalitis caused by free-living amebae naegleria fowleri is extremely rare and uniformly fatal with only seven survivals reported till date. An interesting case of naegleria meningitis diagnosed by wet mount cytology of cerebrospinal fluid (CSF) and treated with amphoterecin B, rifampicin and ornidazole with complete recovery is presented. In cases of suspected pyogenic meningitis, if CSF staining, antigen detection or culture is negative for bacteria, a wet mount cytology of CSF for naegleria is suggested. Early treatment with amphoterecin B and rifampicin may improve survival.

Adult↗
PubMed2002

Validity of self-report of recent opiate use in treatment setting.

Self-report validity of recent drug use among heroin abusers depends on many factors including the population being studied and the setting in which the study is carried out. This study was conducted by the treating physicians to assess the self-report validity of recent heroin use by heroin dependent patients in the outdoor setting using 'thin layer chromatography' (TLC) and two highly sensitive methods of urinalysis viz. 'gas liquid chromatography' (GLC) and 'high performance liquid chromatography' (HPLC). Out of seventy-six heroin dependent patients who entered the study, 64 provided urine sample on the same day. Patients' self-report about recent opiate use was found to have a moderate agreement with urinalysis report. However, it is important to validate it with urinalysis during the treatment process because a substantial proportion of patients fails to report recent opiate use. It is recommended that all drug dependence treatment centres should be equipped with a sensitive urinalysis facility. Otherwise, the outcome of the treatment process should be considered with caution.

Adult↗
PubMed2001

Using an in vivo phagemid system to identify non-compatible loxP sequences.

The site-specific recombination system of bacteriophage P1 is composed of the Cre recombinase that recognizes a 34-bp loxP site. The Cre/loxP system has been extensively used to manipulate eukaryotic genomes for functional genomic investigations. The creation of additional heterologous loxP sequences potentially expands the utility of this system, but only if these loxP sequences do not recombine with one another. We have developed a stringent in vivo assay to examine the degree of recombination between all combinations of each previously published heterologous loxP sequence. As expected, homologous loxP sequences efficiently underwent Cre-mediated recombination. However, many of the heterologous loxP pairs were able to support recombination with rates varying from 5 to 100%. Some of these loxP sequences have previously been reported to be non-compatible with one another. Our study also confirmed other heterologous loxP pairs that had previously been shown to be non-compatible, as well as defined additional combinations that could be used in designing new recombination vectors.

Attachment Sites, Microbiological↗
PubMed2001

Using an in vivo phagemid system to identify non-compatible loxP sequences.

The site-specific recombination system of bacteriophage P1 is composed of the Cre recombinase that recognizes a 34-bp loxP site. The Cre/loxP system has been extensively used to manipulate eukaryotic genomes for functional genomic investigations. The creation of additional heterologous loxP sequences potentially expands the utility of this system, but only if these loxP sequences do not recombine with one another. We have developed a stringent in vivo assay to examine the degree of recombination between all combinations of each previously published heterologous loxP sequence. As expected, homologous loxP sequences efficiently underwent Cre-mediated recombination. However, many of the heterologous loxP pairs were able to support recombination with rates varying from 5 to 100%. Some of these loxP sequences have previously been reported to be non-compatible with one another. Our study also confirmed other heterologous loxP pairs that had previously been shown to be non-compatible, as well as defined additional combinations that could be used in designing new recombination vectors.

Attachment Sites, Microbiological↗
PubMed2001

Regiospecific synthesis of 2,3-disubstituted-L-histidines and histamines.

Regiospecific synthesis of 2,3-disubstituted-L-histidines and 2,3-disubstituted histamines starting from L-histidine methyl ester and histamine is reported. The key step involves homolytic free radical alkylation via silver catalyzed oxidative decarboxylation of alkylcarboxylic acids with ammonium persulfate.

Alkylation↗
PubMed2001

Hydrops fetalis in an interstitial deletion of chromosome 10.

We report the case of a premature neonate with ascites and dysmorphic facial features at birth. The chromosomal analysis showed an interstitial deletion of chromosome 10, that is, 46, XX, del(10)(q22.3q24.1). This is the first known case of a patient with interstitial deletion of chromosome 10 with symptoms of ascites and hydrops.

Chromosome Banding↗
PubMed2001

A fluorescence-based homogeneous assay for measuring activity of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase.

UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) is one of the key enzymes of bacterial lipid A biosynthesis, catalyzing the removal of the N-acetyl group of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine. The lpxC gene is essential in Gram-negative bacteria but absent from mammalian genomes, making it an attractive target for antibacterial drug discovery. Current assay methods for LpxC are not suitable for high throughput screening, since they require multiple product separation steps and the use of radioactively labeled material that is difficult to prepare. A homogeneous fluorescence-based assay was developed that uses UDP-3-O-(N-hexyl-propionamide)-N-acetylglucosamine as a surrogate substrate. This surrogate can be prepared from commercially available UDP-GlcNAc by enzymatic conversion to UDP-MurNAc, which is then chemically coupled to n-hexylamine. Following the LpxC reaction, the free amine of the deacetylation product can be derivatized by fluorescamine, thus generating a fluorescent signal. This surrogate substrate has a K(m) of 367 microM and k(cat) of 0.36 s(-1), compared to 2 microM and 1.5 s(-1) for the natural substrate. Since no separation is needed, the assay is easily adaptable to high throughput screening. IC(50)s of LpxC inhibitors determined using this assay method is similar to those measured by traditional method with the natural substrate.

Amidohydrolases↗
PubMed2001

MR spectrum in spinal dysraphism.

Spinal dysraphism is a general term which encompasses a wide variety of anomalies of the spine, all of which result from imperfect midline fusion of the embryonic neural tube. This term refers to large defects that involve the spine and not to small vertical clefts commonly seen within the spinal process of L5 or S1. We present a spectrum of MR imaging findings selected from a retrospective review of 100 patients of spinal dysraphism evaluated at our institution.

Diagnosis, Differential↗
PubMed2001

Intraspinal neurenteric cysts--report of three paediatric cases.

BACKGROUND: Neurenteric cysts are rare congenital lesions of the spine and are lined with entodermal epithelium. They result from anomalous endodermal-neuroectodermal adhesion in the 3rd week of embryonic life with persistence of canal of Kovalevsky. The nature of the eventual abnormality depends on the extent to which this adhesion subsequently disappears. Persistence of the entire tract results in the extreme form of combined anterior and posterior spina bifida with dorsal enteric fistula and persistence of only a part of the tract producing the isolated intraspinal cyst. The most common location is the cervico-dorsal region, and usually it lies ventral to the spinal cord. The lumbosacral location is uncommon. Associated vertebral anomalies, gut cysts, bowel duplication, the presence of keratin markers and mucin-secreting cuboidal or columnar intestinal epithelium in their walls confirm their entodermal origin. PATIENTS: We describe here three unusual cases of neurenteric cysts in patients aged 5-18 years who had already had symptoms for some time. One of these had a cyst sited predominantly in the sacral canal, another presented with a lumbar neurenteric cyst, and the third patient had an intradural extramedullary thoracic lesion. Two of these children had associated anomalies, the one with lumbar cyst also having a lipomeningomyelocele and spina bifida while the other also had deformed vertebrae. All three patients underwent laminectomy and gross excision of the cysts through a posterior approach. RESULTS AND CONCLUSION: The diagnosis of neurenteric cysts was confirmed by demonstrating mucin-producing cuboidal or columnar epithelium lining the cystic cavity.

Adolescent↗
PubMed2001

Safety and efficacy of AS-1 red blood cell use in neonates.

Many Regional Blood Centers are providing AS-1(Adsol preservative) red blood cells (RBCs) as a standard product because of the extended shelf life (42 days). The use of AS-1 RBCs is concerning in neonates because of high exposure to dextrose, adenine and mannitol. We conducted this study to evaluate the safety and efficacy of AS-1 RBC use in neonates. We assigned one unit of AS-1 RBCs to each infant for small volume transfusions (15 ml/kg) for the life of the unit (42 days). The study was conducted for one year. The infants under 1500 g were included in the study. We measured the pre- and post-transfusion hematocrit, post-transfusion serum sodium, potassium, glucose, bilirubin and blood pH. We compared the average number of transfusions per patient and average blood donor exposure per patient using AS-1 RBC to CPDA-1 packed red blood cells (PRBC) use, data available for prior year. We monitored the blood transfusion reactions during the study period. The hematocrit increased significantly from 30.1 +/- 4.6 pre-transfusion to 38.3 +/- 4.9 post-transfusion. The post-transfusion serum bilirubin, blood pH, serum potassium, sodium and glucose remained within the normal range. In spite of an increase in the number of average transfusions per patient with AS-1 RBC (6.67 +/- 5.1), the average donor exposure (1.8 +/- 1.1) remained less than two donors. There were not any transfusion reactions reported during the study. In conclusion, the use of AS-1 red blood cells is safe for small volume transfusions in neonates.

Adenine↗