Biomedical subjects

Rita Christopher

Publications and source records attributed to Rita Christopher.

7 recordsLinked to original sources

PubMed2006

Thrombophilic gene polymorphisms in puerperal cerebral veno-sinus thrombosis.

Puerperal cerebral veno-sinus thrombosis (PCVT) is a common form of stroke in young women in India, which is associated with high morbidity and mortality. The frequency of PCVT in India is 10 to 12 times more compared to western population. As yet, the etiology of this condition is unclear. Our aim was to study the prevalence and the role of the common genetic polymorphisms associated with thrombophilia such as factor V Leiden, prothrombin G20210A and methylene tetrahydrofolate reductase (MTHFR) C677T, in aseptic PCVT. We investigated 86 women with PCVT and 86 age-matched women with no post-partum complications. Polymerase chain reaction (PCR)/restriction fragment length polymorphism analysis was used to identify their genotypes. The frequency of the three polymorphisms in cases and controls were: factor V Leiden, 2.3% versus 1.2% (OR 0.49, 95% CI=0.02-7.12, p=1.000) and MTHFR C677T, 16.3% versus 17.4% (OR 0.92, 95% CI=0.39-2.19, p=0.838). The prothrombin G20210A variant was not detected in either patients or controls. The clinical characteristics of the PCVT patients with the polymorphisms did not differ significantly from those without them. In our series of PCVT patients, the risk associated with the established thrombophilic risk factors is insignificant. Exploration of these gene polymorphisms seems to be of limited value in the investigation of PCVT in south Indian women.

Adolescent↗

PubMed2006

Factor V gene A4070G mutation and the risk of cerebral veno-sinus thrombosis occurring during puerperium.

INTRODUCTION: Cerebral veno-sinus thrombosis (CVT) occurring during puerperium is a common form of stroke in young women in India, associated with high mortality and morbidity. Genetic polymorphisms involving coagulation factors are considered to be risk factors for thrombosis. A recently identified polymorphism in factor V gene, A4070G (R2 allele), has been reported as a risk factor for venous thrombosis in some studies. Moreover, the R2 allele has been reported to increase factor V Leiden-related thrombosis risk in doubly heterozygous individuals. The risk associated with the R2 allele has not yet been evaluated in CVT. Our aim was to determine the prevalence of factor V A4070G mutation in Indians and examine its role as a possible risk factor for CVT occurring during puerperium. MATERIALS AND METHODS: We investigated 50 patients with puerperal CVT and 100 healthy women with no post-partum complications for factor V A4070G and G1691A (factor V Leiden) polymorphisms using polymerase chain reaction and restriction fragment length polymorphism. RESULTS AND CONCLUSION: Among cases, 6 (12%) were heterozygous for the factor V A4070G mutation and none were homozygous. In the control group, 9 (9%) were heterozygous and 3 (3%) were homozygous. The odds ratio was 1.00 (95% CI: 0.31-3.13, p=1.000), suggesting that the risk for CVT was not increased in the presence of the R2 allele. There was no co-inheritance of factor V A4070G with factor V G1691A in any of the subjects. Our study shows that the A4070G mutation in factor V though highly prevalent in the Indian population is not associated with an increased risk of CVT occurring during puerperium in Indian women.

Alleles↗

PubMed2005

Nuclear localization of Munc18-1 (p67) in the adult rat brain and PC12 cells.

Munc18-1, also referred to as p67, co-purifies with Cdk5 and has an important role in neurotransmitter release. The role of Munc18-1 for functional connectivity of the nervous system was demonstrated by gene knockout experiments in mice, wherein accumulation of neurotransmitter and silencing of synaptic activity was observed. Our earlier studies have shown that both Munc18-1 and Cdk5 co-purify and co-localize with cytoskeletal components, implying that apart from having a regulatory role in vesicle docking and fusion, Munc18-1 could also affect the dynamics of neuronal cytoskeleton. In the present study we have shown the presence of Munc18-1 in nuclear rich fraction from rat brain and confirmed the nuclear localization of this protein in PC12 cells and adult rat brain neurons by immunofluorescence and immunoelectron microscopy. We also demonstrate the binding of Munc18-1 to double stranded (ds) DNA. The ability of Munc18-1 to bind dsDNA, albeit the lack of DNA binding domains, suggests that the binding may be mediated through protein-protein interaction through some other DNA-binding proteins. The presence of both nuclear import and export signals in Munc18-1 primary structure corroborates its nuclear localization and makes it a putative shuttle protein between nuclear and cytoplasmic compartments, the precise physiological relevance of which needs to be elucidated.

Active Transport, Cell Nucleus↗

PubMed2005

Glutamatergic dysfunction in OCD.

The role of glutamatergic dysfunction in the pathophysiology of OCD has hardly been explored despite recent reports implicating glutamatergic dysfunction in OCD. We decided to investigate CSF glutamate levels in adult OCD probands compared to psychiatrically normal controls. In total, 21 consenting psychotropic drug-naïve adult OCD patients, diagnosed using SCID-IV-CV, and 18 consenting psychiatrically normal controls with age within 10 years of age of the patients, who did not have any history of head injury or neurological illness, were included into the study. Aseptically collected and stored CSF samples obtained from the patients and control subjects were used for glutamate estimation, which was carried out by a modification of the procedure described by Lund (1986). CSF glutamate (micromol/l) level was found to be significantly higher [F(1,31)=6.846, p=0.014] in OCD patients (47.12+/-4.25) compared to control subjects (41.36+/-3.63) on analysis of covariance. There was no effect of gender, age, duration of illness, Y-BOCS score, or CGI-S score on CSF glutamate levels. Our study provides preliminary evidence implicating glutamatergic excess in the pathophysiology of OCD, which needs to be further explored by studies from other centers involving larger sample sets from different age groups.

Adolescent↗

PubMed2004

Is low serum tocopherol in Wilson's disease a significant symptom?

BACKGROUND: Free radical mediated injury is increasingly recognized in many metabolic diseases including Wilson's disease (WD). Use of antioxidants as an adjunctive therapy in WD may have therapeutic significance. AIM: The aim of the study was to correlate serum levels of tocopherols with serum copper and ceruloplasmin and clinical status of these patients. METHODS: Serum levels of tocopherol of were measured spectrophotometrically using the Emmerie-Engel reaction in 34 patients from a large cohort of WD being followed up at a tertiary care center. RESULTS: Majority of patients were male (M/F=23:11). The mean serum copper was 43.6+/-26.2 microg/dl (range=10-121 microg/dl) and serum ceruloplasmin was 5.6+/-5.5 mg/dl (range=0-30 mg/dl). The mean serum tocopherol level was 0.68+/-0.18 mg/dl (range=0.23-1.14 mg/dl) and compared to the control (1.07+/-0.17 mg/dl), nearly 59% of patients had decreased levels (p<0.001). No significant correlation was noted between low serum tocopherol levels and serum copper levels, Mini Mental Status Examination (MMSE) scores and CHU staging. However, serum tocopherol levels were lower in patients with relatively short duration of treatment (7.8 years vs. 12.4 years). CONCLUSION: Decreased levels of serum tocopherol were detected in 59% of patients compared to controls. However, low tocopherol levels did not correlate with clinical status or biochemical parameters of WD, except for relatively shorter duration of treatment. Further studies, especially in newly diagnosed patients, need to be done to validate the role of low tocopherol levels in Wilson's disease.

Adolescent↗

PubMed2004

Clinical features of adult GM1 gangliosidosis: report of three Indian patients and review of 40 cases.

Deficiency of enzyme acid beta-galactosidase causes GM1 gangliosidosis. Patients with adult GM1 gangliosidosis typically present with generalized dystonia. We describe clinical, bone marrow, and radiological features of adult GM1 gangliosidosis to help improve its recognition. We report 3 Indian patients and review of reports between 1981 and October 2002. The disease frequently is reported in the Japanese literature (75%). Patients are normal at birth and have normal early motor and mental development. Onset is within the first decade with abnormal gait, or worsening of speech is an initial symptom. Dystonia occurs in 97% of patients. Facial dystonia described as "facial grimacing" observed in approximately 90% could be an important clinical clue. Dysarthria/anarthria (97%) is frequent, and eye movements are normal. Bone marrow examination may show Gaucher-like foam cells (39%). Magnetic resonance imaging (MRI) frequently (90.9%) shows bilateral symmetrical putamenal hyperintensities on T2-weighted and proton density images. Diagnosis is confirmed by demonstrating deficiency of beta-galactosidase. Adult (Type 3) GM1 Gangliosidosis commonly presents with generalized dystonia with prominent facial dystonia, severe speech disturbances, and normal eye movements. Bone marrow frequently shows Gaucher-like foam cells. MRI shows typical lesions in the putamen. Deficiency of beta-galactosidase in fibroblasts confirms the diagnosis.

Adolescent↗

PubMed2004

Cerebral glycolipidoses: clinical characteristics of 41 pediatric patients.

A retrospective clinical and biochemical analysis of 41 pediatric patients with cerebral lipidoses seen between 1995 to 2003 was performed at a tertiary referral center for neurologic disorders in southern India. Enzyme assays in serum and leukocytes, including histopathology, neuroimaging, and neurophysiology studies, were performed. There were 20 cases of metachromatic leukodystrophy (infantile,14; juvenile, 6), 12 cases of Tay-Sachs disease (infantile, 9; late G(M2-M3) gangliosidoses, 3), 8 cases of Sandhoff's disease, and 1 male case with multiple sulfatase deficiency. Consanguinity was present in 51.2% of cases. The male-to-female ratio was 23:17. Similar illness in the families was noted in 24.4%. The prominent clinical features in sulfatide lipidoses were regression of motor and mental milestones, seizures, and speech impairment, and in G(M2) gangliosidoses, the features were delayed milestones, startle myoclonus, seizures, and the presence of cherry-red spots. The case with multiple sulfatase deficiency had low levels of arylsulfatase A and B. This study indicates that these autosomal recessive inherited disorders are indeed prevalent in India.

Adolescent↗