Study of C677T Methylene Tetrahydrofolate Reductase Gene Polymorphism as a Risk Factor for Neural Tube Defects.

INTRODUCTION: Various genetic and environmental factors contribute to the development of neural tube defects (NTDs) which are a group of neurulation defects resulting from failure of closure of embryonic neural tube. Among genetic factors is polymorphism in methylene tetrahydrofolate reductase (MTHFR) gene, giving rise to a gene variant or mutant. However, in most studies directed at finding an association between MTHFR variants and NTD, there is no clear evidence of a cause-and-effect relationship. MATERIALS AND METHODS: Forty diagnosed cases of NTDs and forty healthy individuals were investigated in a case-control study for presence of C677T MTHFR gene polymorphism. Serum folate and Vitamin B12 levels were estimated and MTHFR gene polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: It was found that 32 cases were homozygous with CC genotype and eight were heterozygous with CT genotype, whereas 35 controls had CC genotype and five had CT genotype. TT genotype was absent in both the groups. There was no statistically significant difference between both the groups. No evidence of association between MTHFR C677T polymorphism and NTDs was found. CONCLUSION: Although there was no evidence of association between MTHFR C677T polymorphism and NTDs, our study does not rule out the impact of MTHFR gene mutation on folate metabolism. The reason for absence of TT genotype and no association could be a small sample size. Larger, comprehensive, and well-designed multicentric but feasible studies involving proper subjects and appropriate and adequate controls from several hospitals may provide more meaningful data.

rCBV- and ADC-based Grading of Meningiomas With Glimpse Into Emerging Molecular Diagnostics.

INTRODUCTION: This study was conducted to grade meningiomas based on relative Cerebral Blood Volume (rCBV) and Apparent Diffusion Coefficient (ADC) to help surgeons plan the approach and extent of operation as well as decide on the need of any adjuvant radio/chemo therapy. The current and evolving genomic, proteomic, and spectroscopic technologies are also discussed which can supplement the current radiologic methods and procedures in grading meningiomas. METHODS: A total of 35 patients with meningioma prospectively underwent basic MR sequences (T1W, T2W, T2W/FLAIR) in axial, sagittal and coronal planes followed by Diffusion Weighted (DW) imaging having b value of 1000 (minimum ADC values used for analysis). Then, gadobenate dimeglumine/meglumine gadoterate was administered (0.1 mmol/kg at a rate of 4 mL/s) followed by saline flush (20 mL at a rate of 4 mL/s). Next, T2*W/FFE dynamic images were acquired; dynamics showing maximum fall in intensity was used for creating rCBV and relative Cerebral Blood Flow (rCBF) maps and calculating rCBV. RESULTS: Both maximum rCBV and minimum ADC within the tumor were not significant for differentiating benign from malignant meningiomas. A cut-off maximum rCBV of 2.5 mL/100 g in peritumoral edema was 75% sensitive, 84.6% specific, and 83.3% accurate in differentiating benign from malignant meningiomas. CONCLUSION: Benign and malignant meningiomas can be differentiated based on maximum rCBV in peritumoral edema but ADC values within the tumor are insignificant in differentiating benign and malignant tumors. rCBV values within tumor, however, may be helpful in subtyping meningiomas, especially transitional and meningothelial meningiomas.

Diagnosis of neonatal sepsis using 16S rRNA polymerase chain reaction.

The gold standard for detecting bacterial sepsis is blood culture. However, the sensitivity of blood culture is low and the results take 48-72 h. Molecular assays for the detection of bacterial DNA permit early detection of a bacterial cause as the turnaround time is 6-8 h. We undertook an evaluation of the performance of universal bacterial primer (16S rRNA) polymerase chain reaction (PCR) in the diagnosis of neonatal sepsis at a tertiary care medical college teaching hospital. 16S rRNA PCR was positive in all cases of blood culture proven sepsis. PCR revealed 95.6% sensitivity, 100% specificity, 100% positive predictive value and 91.2% negative predictive value and so appears to be a useful tool for the early diagnosis of bacterial neonatal sepsis.

Macrodystrophia lipomatosa involving multiple nerves.

Macrodystrophia lipomatosa (MDL), a rare congenital disorder, is considered by some to be a localized form of Proteus syndrome. The implication of the PTEN (phosphatase and tensin homolog deleted on chromosome 10) gene in both strengthens this belief. We present a case who had MDL in multiple nerve territories--all on the same side of the body--with hypertrophy of mainly fibroadipose tissue throughout their distribution, thus pointing to a form of localized hemihypertrophy; both hemihypertrophy and lipomatous tumors are components of Proteus syndrome.

Thirteen Years' Experience of Diaphragmatic Injury in Children from the Post Graduate Institute of Medical Sciences (PGIMS), Rohtak, India.

BACKGROUND: Diaphragmatic hernia is migration of abdominal viscera into the thoracic cavity through a defect in the diaphragm. In children, it is mostly congenital; traumatic diaphragmatic hernia being less common. This study aimed to review our experience with traumatic diaphragmatic rupture (TDR) and to identify the clinical findings and diagnostic modality that may help in early diagnosis and prompt therapy. METHODS: The study involved 11 children (1-18 years old) with TDR who were hospitalised between 1993 and 2005. In addition to clinical examination, a plain X-ray of the chest and abdomen, an ultrasound, barium studies, and a computerised tomography (CT) scan were used to evaluate the patients. RESULTS: All of the diaphragmatic ruptures occurred on the left side, with 10 occurring in the posterolateral part and 1 near the oesophageal hiatus. Two of our patients presented 7 and 10 days after the injury, and 1 patient presented 1 year after the trauma. CONCLUSION: TDR should remain a diagnostic possibility in children. These patients are best assessed using a CT scan. New research on stem cells and tissue-engineered bioprosthetics may pave the path for better future therapies in these cases.

Conjoined twins in a spontaneous trichorionic quadruplet pregnancy: a case report.

BACKGROUND: Multifetal pregnancies are high-risk pregnancies. Coexistence of conjoint twins with multifetal pregnancies further increases the risk factor, which is already considerably high with multiple births. Assisted reproductive techniques lead to an increase in multifetal pregnancies, especially monozygotic pregnancies, which in turn lead to an increase in the rate of conjoined twins. CASE: A spontaneously achieved quadruplet pregnancy with coexisting conjoint twins has not been reported previously. We report one such case of spontaneously achieved quadruplet pregnancy with coexisting conjoined twins. CONCLUSION: Early (preferably first trimester) recognition of multifetal pregnancy, chorionicity, amnionicity and fetal malformation help in proper pregnancy management and optimizing outcome.

Neural tube defects: review of experimental evidence on stem cell therapy and newer treatment options.

The failure of closure of the neural tube during development leads to malformations called neural tube defects (NTDs). The most common neural malformations in humans include anencephaly, encephalocele, exencephaly, craniorachischisis spina bifida with or without myelomeningocele, lipomyeloschisis, lipomyelomeningocele, meningocele and myelocystocele. Current preventive strategies are mainly based on pharmacologic/folic acid supplementation. However, stem cell-based and other combination approaches may emerge as potential treatment options for NTDs. This review provides an account of experimental evidence on stem cell therapy and newer treatment options for NTDs which have become available in recent years.

Sequence analysis of 16S rRNA gene inRhinosporidium seeberi shows similarity to plant chloroplast DNA.

UNLABELLED: Identity of causative agent of rhinosporidiosis (Rhinosporidium seeberi) has been controversial since the disease was described in 1900. Extensive sequence alignments and phylogenetic analyses of 16S rRNA gene detected recently by us in R. seeberi , revealed 99% similarity with 16S rDNA in chloroplasts of flowering plants. Study demonstrates R. seeberi is a pigmented prokaryote displaying some characteristics of cyanobacteria, and contains 16S rDNA present in chloroplasts of all groups of land plants. This study and our recent publication of 2006 are the first molecular studies using purified organismal DNA extracted from R. seeberi free of infected tissue. ABBREVIATIONS: RB - Round body.

Thoracic kidney associated with congenital diaphragmatic hernia.

We report three cases of ectopic thoracic (or superior ectopic) kidney; one in a neonate and two in 6-month-old children, associated with congenital diaphragmatic hernia. In all cases the diagnosis was made during surgery and confirmed by intravenous pyelography, sonography and magnetic resonance imaging in the postoperative period. Because of the rarity of this condition we report these cases together with a wide review of the published reports.

Meniscal ossicle.

Meniscal ossicle, or bone within the substance of meniscus, is a rare entity and commonly confused with a loose body both clinically and radiologically. MRI is the modality that can definitely diagnose meniscal ossicle and avoid unnecessary diagnostic arthroscopy. Here we report one such case diagnosed using MRI; this patient is doing well without surgery one year after diagnosis.

Lipoma of Guyon's canal causing ulnar neuropathy.

Lipoma is a benign soft tissue tumor which rarely causes neuropathy. In closed compartments such as Guyon's canal, even small volume loss can lead to compression of nerve. Hence in such areas, even innocuous tumors such as lipomas can cause neuropathy and warrant surgery. We present one such case of ulnar neuropathy caused by lipoma of Guyon's canal.

Complement activation via alternative pathway is critical in the development of laser-induced choroidal neovascularization: role of factor B and factor H.

The objective of this study was to explore the role of classical, lectin, and alternative pathways of complement activation in laser-induced choroidal neovascularization (CNV). The classical and alternative pathways were blocked in C57BL/6 mice by small interfering RNAs (siRNA) directed against C1q and factor B, respectively. C4(-/-) mice developed CNV similar to their wild-type controls and inhibition of C1q by siRNA had no effect on the development of CNV. In contrast, CNV was significantly inhibited (p < 0.001) in C5(-/-) mice and C57BL/6 mice treated with factor B siRNA. Inhibition of the alternative pathway by factor B siRNA resulted in decreased levels of membrane attack complex and angiogenic factors-vascular endothelial growth factor and TGF-beta2. Furthermore, factor B was up-regulated in complement sufficient C57BL/6 mice at day 1 postlaser and remained elevated at day 7. Significantly reduced levels of factor H were observed at day 3 in these animals. In conclusion, our results demonstrate that activation of the factor B-dependent alternative pathway, but not the classical or lectin pathways, was essential for the development of CNV in mouse model of laser-induced CNV. Thus, specific blockade of the alternative pathway may represent a therapeutically relevant strategy for the inhibition of CNV.

Detection of 16S rRNA gene in round bodies isolated from polyps of rhinosporidiosis.

Polyps of rhinosporidiosis contain microscopic round bodies, believed to be causative agents of the disease. The source and identity of these round bodies has been debated ever since the first case was described in the year 1900. Most patients have a history of exposure to pond water. Collection and microscopic analysis of pond water samples where patients had been dipping led to the idea that a cyanobacterium could possibly develop into round bodies after entering the patient's nose. Molecular genomic studies based on PCR, cloning, and sequencing were, therefore, carried out using purified DNA, extracted from individually separated round bodies from polyp samples. Parallel investigations were also conducted on DNA extracted from cyanobacterium Microcystis isolated from pond water samples. The results of these experiments presented here provide evidence of the presence of 1458 bp 16S rRNA gene in round bodies. This is the first molecular study indicating the prokaryotic identity of round bodies in rhinosporidiosis.