Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Efficacy and safety of a single-tablet regimen containing tenofovir disoproxil fumarate 300 mg, lamivudine 300 mg and efavirenz 400 mg as a switch strategy in virologically suppressed HIV-1-infected subjects on nonnucleoside reverse transcriptase inhibitor-containing first-line antiretroviral therapy in Pune, India

OBJECTIVES

As per National AIDS Control Organization (NACO) estimates, there are 2.1 million people living with HIV (PWH) in India, of whom 1.2 million are on first-line antiretroviral therapy (ART). This study explored the use of a single-tablet regimen containing tenofovir disoproxil fumarate 300 mg + lamivudine 300 mg + efavirenz 400 mg (TLE400 STR) as a first-line switch strategy in PWH in Pune, India.

METHODS

This retrospective cohort study was conducted in private sector ART clinics in three tertiary-level hospitals in Pune, India. PWH > 12 years of age (n = 502) who initiated first-line ART (predominantly TLE600 STR), completed ≥ 6 months of follow-up and achieved virological suppression [plasma viral load (VL) < 1000 HIV-1 RNA copies/mL] were identified and switched to TLE400 STR. The virological and immunological efficacy of TLE400 STR at 6 and 12 months of follow-up were noted. Grade 3/4 adverse events (especially efavirenz-related neuropsychiatric adverse events) leading to regimen discontinuation were also noted.

RESULTS

Of 502 PWH who switched to TLE400 STR, complete virological suppression (VL < 20 copies/mL) was maintained in more than 97% of patients at follow-up. TLE400 STR was successful in maintaining CD4 counts within the range observed at the start of the regimen. Grade 3/4 adverse events leading to TLE400 STR discontinuation were seen in 11 (2.2%) patients. Virological failure (VL > 1000 copies/mL) and treatment regimen failure were seen in six (1.2%) and 49 (9.8%) subjects, respectively.

CONCLUSIONS

TLE400 STR exhibits excellent efficacy and safety as a switch strategy and should be introduced in the Indian National ART Program, especially for PWH who are virologically suppressed on TLE600 STR.

Gene therapy as a potential tool for treating neuroblastoma-a focused review

Neuroblastoma, a solid tumor caused by rapid division of undifferentiated neuroblasts, is the most common childhood malignancy affecting children aged <5 years. Several approaches and strategies developed and tested to cure neuroblastoma have met with limited success due to different reasons. Many oncogenes are deregulated during the onset and development of neuroblastoma and thus offer an opportunity to circumvent this disease if the expression of these genes is restored to normalcy. Gene therapy is a powerful tool with the potential to inhibit the deleterious effects of oncogenes by inserting corrected/normal genes into the genome. Both viral and non-viral vector-based gene therapies have been developed and adopted to deliver the target genes into neuroblastoma cells. These attempts have given hope to bringing in a new regime of treatment against neuroblastoma. A few gene-therapy-based treatment strategies have been tested in limited clinical trials yielding some positive results. This mini review is an attempt to provide an overview of the available options of gene therapy to treat neuroblastoma.

5-HT1C receptor-mediated stimulation of inositol phosphate production in pig choroid plexus. A pharmacological characterization

1) 5-HT (5-hydroxytryptamine, serotonin) induces inositol phosphate production in a pig choroid plexus preparation. This effect has been pharmacologically characterized and the data compared to those obtained from radioligand binding studies performed with [3H]mesulergine to 5-HT1C sites in pig choroid plexus membranes. 2) The rank order of potency of agonists stimulating inositol phosphate production was: alpha-methyl-5-HT greater than 1-methyl-5-HT greater than DOI greater than bufotenine = SKF 83566 = 5-HT greater than 5-MeO-DMT greater than 5-MeOT = RU 24969 greater than SCH 23390 greater than 5-CT. 8-OH-DPAT was virtually devoid of activity at 100 mumol/l. 3) The increase in inositol phosphate production induced by 5-HT and other agonists was surmountably antagonised by mesulergine, ketanserin and spiperone with pKB values of 8.7, 6.7 and 5.3, respectively. 4) The rank order of potency of antagonists was: metergoline greater than mesulergine greater than LY 53857 greater than ritanserin greater than methiothepin greater than mianserin greater than cyproheptadine greater than pirenperone greater than cinanserin greater than ketanserin greater than spiperone. The following antagonists were virtually devoid of activity at 100 mumol/l; pindolol, 21-009 and yohimbine. 5) The results obtained both with agonists and antagonists strongly support the view that 5-HT1C receptors mediate agonist induced production of inositol phosphates in pig choroid plexus.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of chronic hydergine treatment on the plasticity of synaptic junctions in the dentate gyrus of aged rats

The number of synapses (Nv), the surface density of contact zones (Sv) as well as the average size (S) of E-PTA stained synapses in the supragranular layer of the dentate gyrus from adult (12 months), old (30 month), and Hydergine-treated old (30 months) rats were measured by using quantitative morphometric techniques. In old animals, Nv and Sv were significantly reduced, whereas S was significantly increased as compared with the values in adult rats. Hydergine (Codergocrine mesylate) treatment of old animals (3 mg/Kg/day for 4 weeks) influenced these three parameters, differentially. The Sv in aged animals receiving Hydergine, relative to that in untreated old rats, was significantly increased; the number and size of synapses in the treated old rats were significantly higher and smaller, respectively, than that in old controls. We interpret the present findings to indicate a modulating effect of Hydergine on the morphological plasticity of synaptic junctions in the dentate gyrus of aged rats.

Unilateral fimbria/fornix lesions attenuate behavioral symptoms induced by subsequent dorsal hippocampal lesions in rats

Adult rats were given a unilateral fimbria-fornix (5, 10, 15 micrograms colchicine or electrolytic) lesion 30 days before a restricted bilateral dorsal hippocampal lesion to assess the behavioral effects of temporally and structurally spaced lesions. The rats were tested 30 days after the second-stage surgery in the Hebb-Williams maze learning task. All rats with lesions were impaired in comparison with sham-operated control rats. However, those which sustained electrolytic or 5 micrograms colchicine fimbria-fornix lesions before hippocampal lesions were less impaired than rats which received hippocampal lesions alone or hippocampal lesions preceded by fimbria-fornix lesions with larger doses of colchicine.

Spontaneous recovery from motor asymmetry in adult rats with 6-hydroxydopamine-induced partial lesions of the substantia nigra

Animals with 6-hydroxydopamine-induced partial unilateral lesions of the substantia nigra exhibit spontaneous recovery from motor asymmetry, a transitory increase in dopamine turnover and an increase in tyrosine hydroxylase activity in the denervated striatum. The recovery of function in these animals seems to be due to the compensatory increase in dopamine metabolism as well as due to the time-dependent increase in tyrosine hydroxylase resulting from either enzyme activation or following reinnervation of the denervated striatum by nigral efferents spared by the partial lesions.

Classification of drugs according to receptor binding profiles

The affinity for eight different neurotransmitter receptors of about forty drugs, used for the treatment of various central nervous system disorders, was determined following in vitro receptor binding assays. Our findings indicate that, in spite of widely varying chemical structures and often poorly understood mechanisms of action, the similarities in the "affinity profiles" permit a clinically meaningful classification of these drugs. Such an approach would thus be useful in the assessment of newly synthesized compounds at an early stage of drug development.

Chronic intraventricular injections of nerve growth factor elevate hippocampal choline acetyltransferase activity in adult rats with partial septo-hippocampal lesions

Nerve growth factor (NGF) was injected intraventricularly during 4 weeks into adult rats with unilateral partial lesions of the cholinergic septo-hippocampal pathway. On the lesioned side, NGF treatment elevated choline acetyltransferase (ChAT) activity up to 60% above the activity measured on the lesioned side of cytochrome c-treated controls. On the unlesioned side, NGF treatment increased ChAT activity only to an insignificant degree. ChAT activity in the septum of NGF-treated animals was increased by 60% as compared to controls. The NGF-induced increases on the lesioned side and in the septum were not accompanied by elevations in acetylcholinesterase (AChE) activity. Furthermore, histochemical analysis revealed no difference in AChE staining pattern or intensity between NGF-treated and control animals. The lack of effect on AChE strongly suggests that the increases in ChAT activity in hippocampus and septum are due to an elevation of ChAT activity within cholinergic neurons surviving the lesion rather than to a promotion of sprouting of cholinergic fibers.

Muscarinic receptors on intact, cultured neurons. Characterization by [3H]quinuclidinylbenzilate binding

[3H]Quinuclidinylbenzilate (QNB) was used to identify muscarinic cholinergic receptors on intact, cultured neurons from fetal rat brains. Scatchard analysis revealed a single binding site with a dissociation constant Kd = approximately or equal to 170 pM. The rank order of potency of cholinergic drugs to displace [3H]QNB from intact neurons was similar to that observed using isolated membranes of brain homogenates. No difference in the rank order was observed with cultures of neurons from different brain regions which vary in their neuronal composition.