Linkage disequilibrium fine mapping and haplotype association analysis of the tau gene in progressive supranuclear palsy and corticobasal degeneration

BACKGROUND

The haplotype H1 of the tau gene, MAPT, is highly associated with progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

OBJECTIVE

To investigate the pathogenic basis of this association.

METHODS

Detailed linkage disequilibrium and common haplotype structure of MAPT were examined in 27 CEPH trios using validated HapMap genotype data for 24 single nucleotide polymorphisms (SNPs) spanning MAPT.

RESULTS

Multiple variants of the H1 haplotype were resolved, reflecting a far greater diversity of MAPT than can be explained by the H1 and H2 clades alone. Based on this, six haplotype tagging SNPs (htSNPs) that capture 95% of the common haplotype diversity were used to genotype well characterised PSP and CBD case-control cohorts. In addition to strong association with PSP and CBD of individual SNPs, two common haplotypes derived from these htSNPs were identified that are highly associated with PSP: the sole H2 derived haplotype was underrepresented and one of the common H1 derived haplotypes was highly associated, with a similar trend observed in CBD. There were powerful and highly significant associations with PSP and CBD of haplotypes formed by three H1 specific SNPs. This made it possible to define a candidate region of at least approximately 56 kb, spanning sequences from upstream of MAPT exon 1 to intron 9. On the H1 haplotype background, these could harbour the pathogenic variants.

CONCLUSIONS

The findings support the pathological evidence that underlying variations in MAPT could contribute to disease pathogenesis by subtle effects on gene expression and/or splicing. They also form the basis for the investigation of the possible genetic role of MAPT in Parkinson's disease and other tauopathies, including Alzheimer's disease.

The H1c haplotype at the MAPT locus is associated with Alzheimer's disease

Although it is clear that microtubule associated protein tau (MAPT) is involved in Alzheimer's disease (AD) pathology, it has not been clear whether it is involved genetically. We have recently examined the MAPT locus in progressive supranuclear palsy and found that a haplotype (H1c) on the background of the well-described H1 clade is associated with PSP. Here we report that the same haplotype is associated with the risk of AD in two autopsy confirmed series of cases with ages at death >65 years.

Identification of a Novel Valosin-Containing Protein Polymorphism in Late-Onset Alzheimer’s Disease

BACKGROUND/AIMS

Recently, mutations in the valosin-containing protein gene (VCP) were found to be causative for a rare form of dementia [Watts GDJ, et al.: Nat Genet 2004;36:377-381]. This gene lies within a region on the genome that has been linked to late onset Alzheimer's disease (LOAD) [Myers A, et al.: Am J Med Genet 2002;114:233-242]. In this study, we investigated whether variation within VCP could account for the LOAD linkage peak on chromosome 9.

METHODS

We sequenced 188 individuals from the set of sibling pairs we had used to obtain the linkage results for chromosome 9 to look for novel polymorphisms that could explain the linkage signal. Any variant that was found was then typed in 2 additional sets of neuropathologically confirmed samples to look for associations with Alzheimer's disease.

RESULTS

We found 2 variants when we sequenced VCP. One was a novel rare variant (R92H) and the other is already reported within the publicly available databases (rs10972300). Neither explained the chromosome 9 linkage signal for LOAD.

CONCLUSIONS

We have found a novel rare variant within the VCP gene, but we did not find a variant that could explain the linkage signal for LOAD on chromosome 9.

Significant effect of NSP-ase enzyme supplementation in sunflower meal-based diet on the growth and nutrient digestibility in broilers

The response of broiler chickens to 3 levels of sunflower meal and 2 levels of NSP-ase enzyme combination (with and without) was investigated in 3 × 2 factorial arrangement under complete randomized design (CRD). A total of 240 Hubbard broiler chicks were fed on practical mash diets having 2950 kcal of ME and 21% CP from 1 to 42 days of age. The BW gain was not significantly reduced when 25% SFM was added in the diets during 1 to 42 days of age. Supplementation of NSP-ase in broiler diets (day 1-42 overall) demonstrated non-significant differences (p < 0.05) across the treatments in terms of FI and BWG. The difference in feed:gain at 15% or 20% SFM was observed to be non-significant. Replacement of SBM with SFM or inclusion of SFM at higher level (25%) increased/deteriorated FCR. The addition of exogenous NSP-ase showed a significant improvement (p < 0.01) in feed:gain. The improvement was clearly demonstrated when SFM was added to the experimental diet at 15% or even 20%. Supplementation of NSP-ase at the 25% inclusion level could not, however, sustain the beneficial effect, which was possibly due to excessively high dietary CF. No difference was noted across the treatments regarding carcass response. Relative gizzard weight and intestinal weight were observed to be improved in birds consuming higher levels of SFM (p = 0.00). The digestibility of CF was observed to improve when SFM was used at 20% and 25% in the diets. No improvement in the digestibility of CF was observed with NSP-ase supplementation, which meant other factors were clearly involved. Supplementation of NSP-ase improved FCR up to 20% SFM. At 25% SFM, no improvement in the digestibility of CF was observed with NSP-ase supplementation.

Phytochemicals as Prototypes for Pharmaceutical Leads Towards Drug Development Against Diabetic Cardiomyopathy

Globally diabetes mellitus (DM) is swiftly reaching epidemic proportions and impose major health care and socio-economic challenges that are associated with its complications. DM is considered as the major risk factor for the development of debilitating micro & macro vascular complications. Clinical studies have revealed that development of diabetic cardiomyopathy (DCM) in subjects with diabetes can occur both- dependent and independent of pre-existing increased risk factors such as poor glycemic control, hyperlipidemia, and or hypertension. Therefore, DCM represents as a major challenge for the clinical community for the prompt diagnosis and devising the treatment paradigm to combat the diabetes induced cardiac dysfunction. In Chinese traditional medical practice, heart ailments have been coped with herbal extracts. Phytochemicals bioavailability and pharmacokinetic properties are to yet be established completely in human subjects. However, tremendous progress has been made to isolate, purify the phytochemicals and characterize their effects on mitigating the development of DCM in pre-clinical models. Currently there are no approved drugs available for the treatment of DCM. In this review, we have discussed the progress made in understanding the mechanisms for the phytochemicals cardio-protective actions in the diabetic milieu and their caveats and provide future perspectives for proposing these agents to serve as prototypes in the development of drugs for the management of DCM.

EEG seizure detection and epilepsy diagnosis using a novel variation of Empirical Mode Decomposition

Epileptic seizure detection and epilepsy diagnosis based on feature extraction and classification using electroencephalography (EEG) signals is an important area of research. In this paper, we present a simple and effective approach based on signal decomposition, using a novel variation of the Empirical Mode Decomposition called Empirical Mode Decomposition-Modified Peak Selection (EMD-MPS). EMD-MPS allows time-scale based de-trending of signals, allowing signals to be separated directly into a de-trended component, and a trend, according to a frequency separation criterion. Features are extracted from the decomposed components, and a simple classifier, namely the 1-NN classifier is used for three classification tasks. The technique is tested on a publicly available EEG database, and a classification accuracy of 99% for epilepsy diagnosis task, and 100% and 98.2% for two seizure detection tasks is obtained. These results are better than, or comparable to previous results using the same EEG database, but have been obtained with a simpler and computationally fast signal analysis and classification method.

Application of a variation of empirical mode decomposition and Teager energy operator to EEG signals for mental task classification

This paper presents a simple and effective methodology for mental task classification using a novel variation of the empirical mode decomposition (EMD) algorithm and the Teager energy operator applied to electroencephalography (EEG) signals. EEG signals corresponding to various types of mental tasks performed by human subjects are decomposed using the variation of EMD, called Empirical Mode Decomposition-Modified Peak Selection (EMD-MPS), which allows direct separation of the signals into a de-trended component, and a trend, according to a frequency separation criterion. Teager energy operator is then applied to calculate the average energy values of both components obtained after signal decomposition using EMD-MPS. These energy values are used to construct feature vectors, and one-versus-one classification of mental tasks is performed using a simple classifier, namely the 1-NN classifier. An average correct classification rate of 87% is obtained, improving on previous results and thereby also demonstrating the effectiveness of the methodology.

Pulmonary function testing and extreme environments

Millions of people worldwide engage in leisure or occupational activities in extreme environments. These environments entail health risks even for normal subjects. The presence of lung disease, or other conditions, further predisposes to illness or injury. Patients who have lung conditions should, but often do not, consult with their pulmonary clinicians before traveling. Normal subjects, including elderly or deconditioned adults, may be referred to pulmonologists for evaluation of risk prior to exposure. Other patients may present for consultations after complications occur. Pulmonary function testing before or after exposure can assist physicians counseling patients about the likelihood of complications.

Beneficial effects of Annona squamosa extract in streptozotocin-induced diabetic rats

INTRODUCTION

The present study investigated the possible therapeutic effects of Annona squamosa (A. squamosa) extract on certain biochemical markers in streptozotocin (STZ)-induced diabetes mellitus in rats.

METHODS

The effects of an aqueous extract of A. squamosa leaves on blood glucose, insulin, C-peptide, albumin, albumin/globulin ratio, urea, uric acid and creatinine and the activities of diagnostic marker enzymes aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma-glutamyl transpeptidase were examined in the plasma, liver and kidney tissues of control and experimental groups.

RESULTS

Oral administration of A. squamosa (300 mg/kg) aqueous extract to diabetic rats for 30 days significantly reduced blood glucose, urea, uric acid and creatinine, but increased the activities of insulin, C-peptide, albumin, albumin/globulin ratio and restored all marker enzymes to near control levels.

CONCLUSION

The present results shown that A. squamosa extract has an antihyperglycaemic effect and consequently may alleviate liver and renal damage associated with STZ-induced diabetes mellitus in rats.

Dental amalgam: effects of alloy/mercury mixing ratio, uses and waste management

BACKGROUND

Silver dental amalgam is one of the oldest filling materials used in dentistry. The American Dental Association (ADA) has estimated that billions of amalgam restorations have been placed in patients in the last 150 years. Due to the presence of mercury and mishandling during the filling make it more controversial. The objective of this study was to conduct a survey of the use of different brands and to assess any deviations in practice from the hand mixing manual method of elemental mercury and alloy in a pestle/mortar and encapsulated form.

METHODS

A questionnaire was sent to 250 of randomly selected dental practitioner in various localities of Karachi. Data was analysed to record the specified brands used along with their powder/liquid (P/L) ratio and the different methods for disposing off mercury in this study.

RESULTS

The most commonly used form of dispensing method was hand mixing (57%) and only 30% of the dentists followed the manufacturer instruction for hand mixing ratio.Eighty-seven percent of dental amalgam restoration was performed and 13% removed by the dentist per month and the method of disposing the amalgam wastage that 55%, 25%, and 20% dentists were used the sink, bin and other methods respectively in their dental clinics.

CONCLUSION

Amalgam restoration is still popular filling material in the posterior region of the mouth but we need to create awareness among the dentists who do not follow the ADA specifications.

Antidiabetic and antioxidant activity of Annona squamosa extract in streptozotocin-induced diabetic rats

INTRODUCTION

The aim of the study is to analyse the antioxidant effect of oral administration of aqueous extract of Annona squamosa (A. squamosa) leaf on blood glucose, haemoglobin, glycosylated haemoglobin, plasma insulin, antioxidant enzymes and lipid peroxidation in liver and kidney to streptozotocin (STZ)-induced diabetic rats.

METHODS

Aqueous extract of A. squamosa on blood glucose, haemoglobin, glycosylated haemoglobin, plasma insulin, serum lipid and the levels of lipid peroxides and antioxidant enzymes, such as catalase, superoxide dismutase, glutathione peroxidase and reduced glutathione, were examined in the liver and kidney tissues of control and experimental groups.

RESULTS

Oral administration of A. squamosa aqueous extract to diabetic rats for 30 days significantly reduced the levels of blood glucose, lipids and lipid peroxidation, but increased the activities of plasma insulin and antioxidant enzymes, like catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase.

CONCLUSION

The A. squamosa aqueous extract supplementation is useful in controlling the blood glucose level, improves the plasma insulin, lipid metabolism and is beneficial in preventing diabetic complications from lipid peroxidation and antioxidant systems in experimental diabetic rats; therefore, it could be useful for prevention or early treatment of diabetes mellitus.

Biochemical effects of Nigella sativa L seeds in diabetic rats

Oral administration of ethanol extract of N. sativa seeds (300 mg/kg body weight/day) to streptozotocin induced diabetic rats for 30 days significantly reduced the elevated levels of blood glucose, lipids, plasma insulin and improved altered levels of lipid peroxidation products (TBARS and hydroperoxides) and antioxidant enzymes like catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase in liver and kidney. The results confirm the antidiabetic activity of N. sativa seeds extract and suggest that because of its antioxidant effects its administration may be useful in controlling the diabetic complications in experimental diabetic rats.

Protective effects of Piper nigrum and Vinca rosea in alloxan induced diabetic rats

In the present study aqueous extract of Piper nigrum seeds and Vinca rosea flowers were administered orally to alloxan induced diabetic rats once a day for 4 weeks. These treatments lead to significant lowering of blood sugar level and reduction in serum lipids. The levels of antioxidant enzymes, catalase and glutathione peroxidase decreased in alloxan induced diabetic rats however these levels returned to normal in insulin, P. nigrum and V. rosea treated rats. There was no significant difference in superoxide dismutase activity in all groups compared to controls. Lipid peroxidation levels were significantly higher in diabetic rats and it was slightly increased in insulin, P. nigrum and V. rosea treated rats as compared to control rat. These results suggest that oxidative stress plays a key role in diabetes, and treatment with P. nigrum and V. rosea are useful in controlling not only the glucose and lipid levels but these components may also be helpful in strengthening the antioxidants potential.

Management of uric acid stone

Uric acid stones are the most readily dissolvable of all types of urinary stones. By maintaining urinary pH between 6.2-6.8 with the use of sodium acid citrate or uralyt-U and reducing serum uric acid by allopurinol, we tried to dissolve 107 stones in 67 patients. Ninety three (86.9%) stones were dissolved and 6 (5.6%) passed spontaneously within a period of one year. Eight (7.5%) stones were removed surgically or with ESWL. Five (7.5%) patients had stone recurrence over a period of 3 years follow-up. Serum uric acid was raised in 19 (28.5%) and urinary uric acid in 12 (18%) patients while urinary pH was low in 46 (69%) patients. For uncomplicated uric acid stones oral chemolysis on an out-patient basis is the treatment of choice. It is simple, safe and inexpensive. However, it requires rigid compliance by the patient and strict follow-up by ultrasonography (JPMA 42: 153, 1992).