Expression of the neurotrophin receptors Trk A and Trk B in adult human astrocytoma and glioblastoma

Neurotrophins and their receptors of the Trk family play a critical role in proliferation, differentiation and survival of the developing neurons. There are reports on their expression in neoplasms too, namely, the primitive neuroectodermal tumours of childhood, and in adult astrocytic gliomas. The involvement of Trk receptors in tumour pathogenesis, if any, is not known. With this end in view, the present study has examined 10 tumour biopsy samples (identified as astrocytoma, pilocytic astrocytoma and glioblastoma) and peritumoral brain tissue of adult patients, for the presence of Trk A and Trk B receptors, by immunohistochemistry. The nature of the tumour samples was also confirmed by their immunoreactivity (IR) to glial fibrillary acidic protein. In the peritumoral brain tissue, only neurons showed IR for Trk A and Trk B. On the contrary, in the tumour sections, the IR to both receptors was localized in the vast majority of glia and capillary endothelium. There was an obvious pattern of IR in these gliomas: high levels of IR were present in the low-grade (type I and II) astrocytoma; whereas in the advanced malignant forms (WHO grade IV giant cell glioblastoma and glio-blastoma multiforme) the IR was very weak. These findings suggest that Trk A and Trk B are involved in tumour pathogenesis, especially in the early stage, and may respond to signals that elicit glial proliferation, and thus contribute to progression towards malignancy.     

Glaucoma: An Extension of Various Chronic Neurodegenerative Disorders

The eyes are the window of the brain; various pathologies of the eyes can be explained on the basis of neurological disorders and vice versa. Today, our only approach for the management of glaucoma is intraocular pressure (IOP) reduction, whether by pharmacological or surgical methods. Available methods may effectively control IOP but fall short of stopping the progression of glaucoma. IOP is just one of the risk factors our therapy addresses, so we need to work towards shifting our approach towards addressing other factors involved in the etiopathogenesis of the disease. Pathogenesis of glaucoma at molecular level can be compared with that of common neurodegenerative diseases like Alzheimer’s and Parkinsonism. Targets for therapeutic intervention in chronic neurodegenerative diseases and glaucoma include apoptosis, axonal transport, free radical damage, role of polyunsaturated fatty acids, chaperones, gene regulation, etc. p38MAPK is a common pathway involved in all the neurodegenerative disease and glaucoma as well, and more research in this direction can be really beneficial for the development of novel diagnostic and therapeutic measures.     

Protective role of IL-18 −137G/C polymorphism in a North Indian population with asthma: A pilot study

BackgroundIL-18, a pleiotropic, pro-inflammatory cytokine that plays a major role in innate as well as acquired immunity, has been implicated in asthma etiology and this is the first study investigating the role of IL-18 ?137G/C (rs 187238) promoter polymorphism in asthma pathogenesis in a North Indian population.MethodsA pilot study was conducted with a total of 824 subjects, out of which 410 were asthma patients including 323 patients suffering from allergic rhinitis and 414 healthy controls from regions of North India. Tetra-Primer Amplification Refractory Mutation System Polymerase Chain Reaction (Tetra-Primer ARMS PCR) was used for genotyping the IL-18 ?137G/C polymorphism.ResultsWhile the homozygous wild (GG) genotype was equally prevalent in asthma patients as well as control subjects (70.0%), the homozygous mutant (CC) genotype was more prevalent among the controls (8.0%) than in asthma patients (3.4%), which yielded a significant protection or decreased risk towards asthma. Statistical analysis revealed Odds Ratio (OR) = 0.43 (95% CI = 0.21–0.85), Chi² (χ²) = 6.93 and p-value = 0.008 (p < 0.005). Moreover, a few asthma phenotypic traits also revealed significant protective associations with the polymorphism.ConclusionsThe IL-18 ?137G/C polymorphism confers a significant protection from asthma in the studied North Indian population. This is the first study to report the protective association of the polymorphism with the disease.     

Functional screening of enzymes and bacteria for the dechlorination of hexachlorocyclohexane by a high-throughput colorimetric assay

Two distinct microbial dehalogenases are involved in the first steps of degradation of hexachlorocyclohexane (HCH) isomers. The enzymes, LinA and LinB, catalyze dehydrochlorination and dechlorination reactions of HCH respectively, each with distinct isomer specificities. The two enzymes hold great promise for use in the bioremediation of HCH residues in contaminated soils, although their kinetics and isomer specificities are currently limiting. Here we report the functional screening of a library of 700 LinA and LinB clones generated from soil DNA for improved dechlorination activity by means of a high throughput colorimetric assay. The assay relies upon visual colour change of phenol red in an aqueous medium, due to the pH drop associated with the dechlorination reactions. The assay is performed in a microplate format using intact cells, making it quick and simple to perform and it has high sensitivity, dynamic range and reproducibility. The method has been validated with quantitative gas chromatographic analysis of promising clones, revealing some novel variants of both enzymes with superior HCH degrading activities. Some sphingomonad isolates with potentially superior activities were also identified.     

Fine needle aspiration cytology in lymphadenopathy of HIV-positive cases

OBJECTIVE: To evaluate the role of fine needle aspiration biopsy (FNAB) material in 25 HIV-positive cases with lymphadenopathy. STUDY DESIGN: We selected 25 cases for the present study who were enzyme-linked immunosorbent assay positive for HIV (HIV-1). FNAB was performed as a routine, outdoor procedure with informed consent of the patient. For each case, along with routine May-Grünwald-Giemsa and hematoxylin and eosin staining, Ziehl-Neelsen staining for acid-fast bacilli and periodic acid-Schiff staining for fungi were performed wherever necessary. RESULTS: A total of 28 sites were aspirated from 25 HIV patients. All these patients were heterosexual, and none had a history of drug abuse. FNAB was performed under ultrasound guidance in all four cases of a retroperitoneal group of lymph nodes. The most common FNAB diagnosis was reactive lymphoid hyperplasia (10), followed by tuberculosis (8). There were three cases diagnosed as fungal infection (two, Cryptococcus; one, histoplasmosis). FNAB of a case of lymph node was suggestive of tuberculosis. There was one case each diagnosed as non-Hodgkin's lymphoma and squamous cell carcinoma (metastatic). One case of a small axillary lymph node did not yield representative material. CONCLUSION: FNAB is a relatively inexpensive initial investigative technique in the diagnosis and management of HIV-positive patients. It can obviate the need for surgical excision and enable immediate treatment of specific infections.     

Impact of lead exposure on pituitary-thyroid axis in humans

Thyroid function tests (serum levels of thyroxine-T4, triiodothyronine-T3 and thyroid stimulating hormone-TSH) were performed in fifty-eight men (mean age: 31.7±10.6 years; mean duration of lead exposure: 156.9±122.7 months). These subjects were exposed to lead either as petrol pump workers or automobile mechanics. The mean whole blood lead (Pb-B) levels were 2.49±0.45 mole/l (51.90±9.40 g/dl) in the lead exposed workers and were approximately 5 times higher than in the control (n=35) subjects. No significant alteration was seen in their mean T3 and T4 levels as compared with the controls. Interestingly, T3 was significantly lower with the longer (210 months) exposure time in comparison with the group having shorter (29 months) exposure duration. The mean TSH levels were significantly (p<0.01) higher in workers exposed in comparison with the control group. This rise in TSH was independent of exposure time, but it was definitely associated with the Pb-B levels. The increase being more pronounced with mean Pb-B levels of 2.66±0.2 mole/l (55.4±4.25 g/dl) when compared with the group having mean levels of 1.51±0.30 mole/l (31.5±6.20 g/dl). The rise is TSH associated with Pb-B levels was only statistical valid, however, the levels fall within the normal laboratory range. We thus conclude that the Pb-B levels of 2.4 mole/l (50 g/dl) could enhance the pituitary release of TSH without having any significant alterations in the circulating levels of T3 and T4.     

Synthesis of 4-(1-oxo-isoindoline) and 4-(5,6-dimethoxy-1-oxo-isoindoline)-substituted phenoxypropanolamines and their beta1-, beta2-adrenergic receptor binding studies

Phenoxypropanolamines with 1-oxo-isoindoline and 5,6-dimethoxy-1-oxo-isoindoline groups at the para position were synthesized. beta1, beta2-Adrenergic receptor binding affinities for the synthesized compounds were tested and compared with propranolol and atenolol. It was found that the incorporation of para-amidic functionality within the 1-oxo-isoindoline ring and 5,6-dimethoxy-1-oxo-isoindoline ring system led to a high degree of cardioselectivity in the phenoxypropanolamines. Two of the compounds and possessed beta1-adrenergic receptor affinity comparable with that of atenolol and both showed a better cardioselectivity than atenolol. Both and are undergoing further pharmacological evaluation.