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V Ravi

Publications and source records attributed to V Ravi.

At least 37 records · Page 2Linked to original sources
PubMed2003

Role of posterior stabilisation in the management of tuberculosis of the dorsal and lumbar spine.

We present a prospective study of patients with tuberculosis of the dorsal, dorsolumbar and lumbar spine after combined anterior (radical debridement and anterior fusion) and posterior (instrumentation and fusion) surgery. The object was to study the progress of interbody union, the extent of correction of the kyphosis and its maintenance with early mobilisation, and the incidence of graft and implant-related problems. The American Spinal Injury Association (ASIA) score was used to assess the neurological status. The mean preoperative vertebral loss was highest (0.96) in the dorsal spine. The maximum correction of the kyphosis in the dorsolumbar spine was 17.8 degrees. Loss of correction was maximal in the lumbosacral spine at 13.7 degrees. All patients had firm anterior fusion at a mean of five months. The incidence of infection was 3.9% and of graft-related problems 6.5%. We conclude that adjuvant posterior stabilisation allows early mobilisation and rehabilitation. Graft-related problems were fewer and the progression and maintenance of correction of the kyphosis were better than with anterior surgery alone. There is no additional risk relating to the use of an implant either posteriorly or anteriorly even when large quantities of pus are present.

Adolescent↗
PubMed2002

Evaluation of a one-tube RT-PCR system for detection of enteroviruses.

BACKGROUND: A highly sensitive PCR assay for early and rapid detection of enteroviral (EV) RNA in CSF is necessary to investigate the role of EV in acute neurological illnesses. OBJECTIVES: To evaluate and compare two PCR protocols (Titan one-tube RT-PCR and random primed RT-PCR) for detection of enteroviral RNA in CSF. STUDY DESIGN: The PCR protocols were evaluated for lower limit of input detection using log dilutions of five stock EV strains and an isolate of enterovirus-71 in minimum essential medium and three EV stock strains in CSF. The tests were also applied on 77 CSF samples, 46 from patients with suspected acute EV neurological illness and 31 from 'disease controls'. RESULTS: Even though in the initial virus titration assays there was no statistically significant difference in the limit of input detection by Titan system and the random primed two-step PCR, the latter had a higher positivity rate when used on CSF samples from patients (20/46 vs. 10/46, P<0.01). CONCLUSIONS: Random primed RT-PCR assay is superior to Titan one-tube RT-PCR for detection of EV RNA in CSF.

Enterovirus↗
PubMed2002

Dengue fever outbreaks in two villages of Dharmapuri district in Tamil Nadu.

BACKGROUND & OBJECTIVES: Dengue fever is an important public health problem in India. In recent years this disease has extended to rural areas also due to rapid urbanization. In Tamil Nadu, fever outbreaks were reported in two villages of Dharmapuri district during May and September 2001 with clinical symptoms suggestive of dengue fever. Epidemiological, virological and entomological investigations were carried out in these two villages to ascertain the etiology of the outbreaks. METHODS: Paired serum samples were collected from febrile patients clinically suspected to have dengue and were tested for the presence of IgM antibodies to dengue virus by MAC ELISA. Samples were also tested by Dengue Duo IgM/IgG rapid strip. Surveys of larval and adult Aedes mosquitoes were carried out before and after anti-larval and anti-adult measures were implemented. Female Ae. aegypti mosquitoes collected in Mampatti village were tested individually for the presence of dengue-2 viral antigen by indirect immunofluorescence assay (IIFA). In addition, two pools of female Ae. aegypti mosquitoes were tested for the presence of dengue viral antigen by ELISA and then subjected to Toxo-IFA system for demonstration of dengue virus. RESULTS: A total of 124 and 267 fever cases with clinical symptoms and signs suggestive of dengue were reported in Kadumuchandiram and Mampatti villages of Dharmapuri district, respectively. Serodiagnosis revealed that 13 of 31 and 14 of 52 patients tested were positive for dengue-2 virus by MAC ELISA in Kadumuchandiram and Mampatti villages respectively. Dengue Duo rapid strip test also detected 14 (of 31 tested) patients positive for dengue virus specific IgM antibodies in Kadumuchandiram village and 8 (of 12 tested) in Mampatti village. Application of temephos and fogging with pyrethrum 2 per cent extract were found to be effective against immatures and adults respectively. Both the pools of Ae. aegypti tested for the presence of dengue viral antigen were positive by ELISA and one mosquito (tested individually) was positive by IIFA. Supernatants of two pools were found to be positive for dengue-2 virus by Toxo-IFA. INTERPRETATION & CONCLUSION: Virological and serological investigations confirmed that the outbreaks of fever were due to dengue virus infection. High breeding of Ae. aegypti in the study villages, detection of dengue-2 viral antigen and isolation of dengue-2 virus in Ae. aegypti mosquitoes confirmed the etiology.

Dengue↗
PubMed2001

Persistent movement disorders following Japanese encephalitis.

The authors report on movement disorders that persist for a long duration following Japanese encephalitis (JE). Fifteen patients with diagnosed JE were followed up after an interval of 3 to 5 years. Of the four patients with a movement disorder, two were children with severe generalized dystonia in whom MRI revealed bilateral thalamic lesions. The two adult patients had parkinsonism. MRI in both adult patients showed lesions confined to the substantia nigra. Viral antibody and antigen were absent in the CSF of all patients.

Acute Disease↗
PubMed2000

The Wuchereria bancrofti orthologue of Brugia malayi SXP1 and the diagnosis of bancroftian filariasis.

The gene encoding the Wuchereria bancrofti orthologue of the Brugia malayi-derived diagnostic antigen SXP1 was identified from a W. bancrofti L3 cDNA library and characterized. The Wb-sxp-1 cDNA encoded a basic protein with a calculated molecular mass of 20.8 kDa. Wb-SXP-1 was 85% identical to the SXP1 protein described from B. malayi (Bm-SXP-1). The Wb-SXP-1 sequence also showed significant identity with proteins described from B. pahangi, Onchocerca volvulus, Acanthochilonema vitea, Ascaris suum, Loa loa, Litomosoides sigmodontis and Caenorhabditis elegans. The presence of a number of invariant and conserved residues in all of these nematode-derived molecules suggests that Wb-SXP-1 is a member of a new protein family. A recombinant form of Wb-SXP-1 was produced and it was determined that the anti-Wb-SXP-1 antibody response in patients with W. bancrofti infections was restricted to the IgG4 subclass. An anti-Wb-SXP-1 IgG4 ELISA was developed and this assay was found to be 100% sensitive for patients with patent W. bancrofti infection. Sera from individuals experiencing chronic pathology, endemic normals or patients with non-filarial nematode infections had no detectable IgG4 against Wb-SXP-1. While patients with patent Onchocerca volvulus infections were uniformly negative in the Wb-SXP-1 assay, 40% of sera from patent Loa loa infections were positive. When Bm-SXP-1 was used as the antigen under identical conditions, the assay was 88% specific for patent W. bancrofti infections and the antigen was recognized by antibodies from both O. volvulus and L. loa infections. The results strongly suggested that, for certain diagnostic filarial antigens, the use of same-species molecules can enhance the specificity of diagnostic tests.

Amino Acid Sequence↗
PubMed2000

HIV antibody profiles in serum and CSF of patients with neurological disease can serve as predictors of outcome.

The serum and CSF antibody profiles were investigated in 100 patients with HIV in relation to the type and severity of neurological disease. Among them, 87 were positive for anti-HIV antibodies in the CSF. In 30 of 87 patients detailed analysis by western blot could be performed. In 20 of 30 the profiles were dissimilar, with more of bands being found in the serum than in the CSF. The correlation of western blot profiles to the clinical outcome indicated that the number of anti-HIV antibody bands as well as the index in the CSF of fatal cases were significantly less compared with non-fatal cases (p=0.019 and p=0.039 respectively).

Adolescent↗
PubMed2000

Profile of neurologic disorders associated with HIV/AIDS from Bangalore, south India (1989-96).

One hundred patients (95 males, 5 females, mean age at presentation 31.6 +/- 9.4 yr) with various neurological disorders associated with HIV infection during 1989-1996 were evaluated at NIMHANS, Bangalore. Eighty patients belonged to group I associated with opportunistic neuroinfections and 20 to group II--non infectious neurological disorders. Cryptococcal meningitis either alone (n = 31) or associated with tuberculous meningitis (n = 6) was the most common (46.3%) followed by neurotuberculosis either alone (n = 24) or with cerebral toxoplasmosis (n = 4) accounting for 35 per cent. Other opportunistic neuroinfections included cerebral toxoplasmosis, herpes zoster, fulminant pyogenic meningitis and neurosyphilis. Clinical characteristics, diagnostic clues, their laboratory and radiological profiles and problems encountered in diagnosis and management of these opportunistic infections are highlighted. In group II (19 males and one female; mean age of 32.6 +/- 9.4 yr), two patients had cortical dementia, three acute brain stem involvement, two epilepsy and one had features suggestive of progressive multifocal leukoencephalopathy. Two patients of group I during follow up developed cortical dementia. Six had peripheral nervous system involvement similar to Guillain-Barre syndrome. Sixty six patients (63 of group I and 3 of group II) progressed to AIDS, 33 patients from group I and one patient from group II succumbed to the disease. With the rapid increase in the incidence of HIV/AIDS and an increase in the neurological manifestations of HIV/AIDS it is important to recognise the magnitude of the problem for health planning in India.

AIDS-Related Opportunistic Infections↗
PubMed2000

First outbreak of Japanese encephalitis in two villages of Dharmapuri district in Tamil Nadu.

BACKGROUND & OBJECTIVES: Three cases of Japanese encephalitis (JE) were reported for the first time from two villages in Krishnagiri Health Unit district of Tamil Nadu during November 1999. Two children died and one developed neurological sequelae. A serological survey was conducted in these villages to find out the prevalence of JE antibodies among children below 15 yr of age in addition to the epidemiological investigations. METHODS: The prevalence of haemagglutination inhibiting (HI) antibodies to JE virus (JEV), West Nile virus (WNV) and dengue-2 virus (DEN-2) was detected by HI test and IgM antibody capture ELISA (MAC ELISA) was performed to determine recent infections with JE virus. Adult mosquitoes were collected in the study villages and females of Culex pseudovishnui, C. tritaeniorhynchus and C. vishnui were tested for the presence of JE viral antigen by ELISA. RESULTS: Out of 146 sera samples from children below 15 yr, the prevalence of HI antibodies to JEV, WNV and DEN-2 virus was found to be 8.9, 3.4 and 6.85 per cent respectively and three children had IgM antibodies to JEV. Of the 13 species of mosquitoes identified, C. tritaeniorhynchus (30.8%) was the most abundant species in the study villages. Two pools of female C. tritaeniorhynchus were found to be positive for JEV antigen. Fogging with 2 per cent pyrethrum and residual spray with 10 per cent cyfluthrin were effective in reducing vector density. INTERPRETATION & CONCLUSIONS: Serological investigations revealed that the JE virus was predominant in the study villages. In addition, DEN-2 and WN viruses were also prevalent. Detection of JE virus specific IgM antibodies in three specimens and the presence of JE viral antigen in 2 pools of C. tritaeniorhynchus emphasized the need for constant surveillance and monitoring so as to prevent future large outbreaks.

Adolescent↗
PubMed1999

Oral immunisation of mice with live Japanese encephalitis virus induces a protective immune response.

This study was undertaken to evaluate the efficacy of oral immunisation of mice with live Japanese encephalitis virus (JEV). Swiss albino mice were immunised with JEV by the peroral (p.o.), intraperitoneal (i.p.) and the subcutaneous (s.c.) routes on days 0, 7 and 14 using either mouse brain derived immunogen (MBDI) or cell culture derived immunogen (CCDI). Oral immunisation of mice evoked high anti-JEV antibody titres by ELISA (Geometric mean titres of 5065 with CCDI and 8854 with MBDI). Moreover, the orally immunised mice showed 76.7% protection with MBDI and 70% with CCDI against intracerebral challenge with a lethal dose of JEV. This study demonstrates for the first time that oral immunisation of mice with live JEV generates a brisk, protective immune response. The results of this study suggest that oral immunisation with JEV holds promise for the future.

Administration, Oral↗
PubMed1998

Anxiety and depression among HIV-infected heterosexuals--a report from India.

The aim of the study was to study factors related to anxiety, depression, and suicidal ideation among HIV-seropositive heterosexuals soon after being tested for their HIV status for the first time. Anxiety, depression, and suicidal ideation were assessed among 51 HIV-seropositive heterosexual men and women with various stages of HIV infection. All assessments were done between 4 and 6 weeks after revelation of positive serostatus. Psychosocial variables such as quality of family relationships and substance use and sociodemographic details such as gender, income, education, and residence were studied for their association with psychiatric morbidity. Illness details studied for their association with psychiatric morbidity included stage of HIV infection, spouse's HIV status, presence of physical illness, and pain. Depression was present in 40% and anxiety in 36% of the sample. Serious suicidal intent was seen in 14%. Multiple regression analysis indicated that presence of pain, concurrent alcohol abuse, poor family relations, and presence of AIDS in the spouse were significant factors associated with depression, anxiety, and suicidal ideation.

Adult↗
PubMed1998

Functional analysis of the herpes simplex virus type 2 strain HG52 RL1 gene: the intron plays no role in virulence.

Sequence analysis predicts that herpes simplex virus type 2 (HSV-2) strain HG52 contains an open reading frame, RL1, encoding a polypeptide equivalent to ICP34.5 of HSV-1. Similarly to HSV-1, deletion of the region spanning RL1 abolishes the virulence of HSV-2 strain HG52 and its ability to grow in stationary 3T6 cells. In contrast to HSV-1, the HSV-2 strain HG52 RL1 gene is predicted to contain a 154 bp intron. Previously, we have demonstrated that this intron is spliced from RL1 poly(A)+ mRNA at the predicted splice donor/ acceptor sites. To determine if the intron affects the function of ICP34.5 of HSV-2 strain HG52, we have constructed a virus, 2624, in which the RL1 intron is deleted: 2624 retains wild-type growth both in vivo and in 3T6 cells, indicating that the presence of an intron does not affect the function of RL1 in HSV-2 strain HG52. 2624 has wild-type growth kinetics in BHK21/C13 cells.

Animals↗
PubMed1997

Cerebrospinal fluid viral antibodies in obsessive-compulsive disorder in an Indian population.

Immunoglobulin G viral antibodies for herpes simplex virus type 1, varicella zoster virus, cytomegalovirus, measles, and mumps were studied in 76 subjects with obsessive-compulsive disorder and compared with a control population. There was a significantly higher titer for herpes simplex virus type 1 antibodies. Sera: cerebrospinal fluid ratios were suggestive of intrathecal synthesis.

Adolescent↗
PubMed1997

Co-existence of cerebral cysticercosis with Japanese encephalitis: a prognostic modulator.

In this study, we investigated the frequency of co-existence of cerebral cysticercosis (CC) in Japanese encephalitis (JE) cases with special emphasis on its role in predicting the final clinical outcome. Amongst the 163 confirmed cases of JE, 37.42% (61/163) had co-existent CC. This was confirmed by antibody detection in the CSF of 45 cases, CT scan of the brain in 6 cases and at autopsy in 3 cases. In 2 cases confirmation was possible by CT scan as well as at autopsy, in 4, CSF antibody levels and CT scan were suggestive of CC while in 1, CSF antibodies and autopsy were suggestive of CC The co-occurrence of Cysticercus cellulosae in the brain emerged as a prognosticator of poor outcome in JE cases (P < 0.03).

Adolescent↗
PubMed1997

Correlation of tumor necrosis factor levels in the serum and cerebrospinal fluid with clinical outcome in Japanese encephalitis patients.

To investigate the prognostic role of tumour necrosis factor (TNF) in Japanese encephalitis virus (JEV) infection, we measured the immunoreactive forms of TNF concentrations in the serum and cerebrospinal fluid (CSF) of 47 laboratory-confirmed cases of JE. It was observed that TNF levels were elevated (> 15 pgm/ml) in all the 47 serum samples (range 19.4-923.8 pg/ml), while in 46/47 CSF samples TNF was elevated (range 10.8-376 pg/ml). The mean (SD) TNF levels in the serum of fatal cases was 234.34 pg/ml (304.40) as compared to the mean of 85.31 pg/ml (SD 153.92) in nonfatal cases. Similar observations were also made with respect to the TNF levels in the CSF; the mean of fatal cases was 69.39 pg/ ml (SD 39.00) in contrast to the mean of 62.41 pg/ml (SD 75.25) of nonfatal cases. The increase in TNF levels did not show any correlation to the duration of illness. It was further observed that the mortality rate increased with increasing concentrations of TNF in the serum and CSF. Correlation of laboratory parameters to final outcome revealed that TNF concentrations above 50 pg/ ml in serum correlated significantly (P = .05) with a fatal outcome, whilst high levels of JEV-IgM antibodies (> 500 units) in the CSF correlated with a nonfatal outcome (P = .03). These results suggest that TNF can be used as a possible prognosticator of a fatal outcome in JEV infection.

Adolescent↗
PubMed1996

Review on tropical root and tuber crops. I. Storage methods and quality changes.

The root tuber crops, including cassava, sweet potato, yams, and aroids, enjoy considerable importance as a vegetable, staple food, or raw material for small-scale industries at a global level, particularly in the less developed tropical countries. The perishability and postharvest loses of root and tuber crops are the major constraints in the utilization of these crops. Several simple, low-cost traditional methods are being followed by farmers in different parts of the world to store different root and tuber crops in the fresh state. An account of different storage practices and constraints is reviewed in this article. Some of these methods have been studied and evaluated by different research workers. Several modern techniques, including refrigerated cold storage, freezing, chemical treatments, wax coating, and irradiation, for storing fresh tropical tubers are also reviewed. The pre- and postharvest factors to be considered for postharvest storage of different root and tuber crops are incorporated into the review.

Africa↗
PubMed1996

Review on tropical root and tuber crops. II. Physiological disorders in freshly stored roots and tubers.

Tropical root and tubers, including cassava, sweet potato, yams and aroids, have been reported to show an increase in respiratory activity after harvest and injury and subsequent storage in association with their deterioration. This leads to loss of water and carbohydrate. Cassava roots often show discoloration of the tissue with development of pigments in the xylem vessels (vascular streaking or primary/physiological deterioration). This has been established to be enzymatic in nature. Pruning the cassava stem, leaving about a 20- to 30-cm stub prior to harvest, could delay the onset of primary deterioration. Sweet potato roots and yam tubers show a peak respiratory activity immediately or 1 d after harvest. The respiratory rate, however, declines during the subsequent storage period. Yam tubers show a further increase in respiratory activity at the breakage of dormancy occurring at the time of sprouting. Dormancy in yam tubers has been studied in some detail. Different species of yams vary in their dormancy period, a major factor that accounts for the variation in their storage life. Little information is available on the dormancy of sweet potato and aroids. Tropical roots and tubers exhibit "chilling injury" when stored at temperatures below a critical level. The critical cold-storage temperatures range between 10 and 15 degrees C for different tropical root and tuber crops.

Carbohydrates↗
PubMed1996

Protection of adult but not newborn mice against lethal intracerebral challenge with Japanese encephalitis virus by adoptively transferred virus-specific cytotoxic T lymphocytes: requirement for L3T4+ T cells.

The protective ability of cytotoxic T cells (CTL) raised in vitro against Japanese encephalitis virus (JEV) was examined by adoptive transfer experiments. Adoptive transfer of anti-JEV effectors by intracerebral (i.c.) but not by intraperitoneal (i.p.) or intravenous (i.v.) routes protected adult BALB/c mice against lethal i.c. JEV challenge. In contrast to adult mice, adoptive transfer of anti-JEV effectors into newborn (4-day-old)and suckling (8-14-day-old) mice did not confer protection. However, virus-induced death was delayed in suckling mice compared to newborn mice upon adoptive transfer. The specific reasons for lack of protection in newborn mice are not clear but virus load was found to be higher in newborn mice brains compared to those of adults and virus clearance was observed only in adult mice brains but not in newborn mice brains upon adoptive transfer. Specific depletion of Lyt 2.2+, L3T4+ or Thy-1+ T cell populations before adoptive transfer abrogated the protective ability of transferred effectors. However, when Lyt 2.2+ cell-depleted and L3T4+ cell-depleted effectors were mixed and transferred into adult mice the protective activity was retained, demonstrating that both Lyt 2.2+ and L3T4+ T cells are necessary to confer protection. Although the presence of L3T4+ T cells in adoptively transferred effector populations enhanced virus-specific serum neutralizing antibodies, the presence of neutralizing antibodies alone without Lyt 2.2+ cells are not sufficient to confer protection.

Aging↗