Sm3+ doped calcium orthovanadate Ca3(VO4)2 - A spectral study

Sm³⁺-doped vanadate-based phosphors, Ca_3-x (VO₄)₂:Sm_x(x = 0.005 ≤ x ≤ 0.095), were synthesized by the citrate-based sol-gel method. The samples were characterized with XRD, SEM, diffuse reflectance and photoluminescence spectroscopy, aiming at the development of phosphor-converted wLED applications. Using diffuse reflectance spectra and the Kubelka-Munk function, the band gap energy was calculated to be 3.28 eV for the Ca_2.95(VO₄)₂:Sm_0.05 phosphor. Observation of the photoluminescence excitation spectra revealed a broadband excitation from the distorted VO₄ tetrahedron and a few narrow peaks from the 4f-4f intra-configuration transitions of the Sm³⁺ ions. Upon 404 nm excitation, ⁴G_5/2 → ⁶H_5/2 (564 nm), ⁴G_5/2 → ⁶H_7/2 (601 nm), ⁴G_5/2 → ⁶H_9/2 (648 nm) and ⁴G_5/2 → ⁶H_11/2 (701 nm) transitions were observed. The optimum Sm³⁺ concentration for the studied phosphor is 0.05 mol, and the estimated critical distance between Sm³⁺ ions (R_c) is 19.1 Å. The observed quenching of Sm³⁺ emission is attributed to the dipole-dipole interactions. The possible cross-relaxation process between neighboring Sm³⁺ ions was discussed in detail. The CIE coordinates were calculated for all the samples, and they set on the orange region of CIE diagram. In addition, pure orange color emission was observed under 365 nm UV lamp. The results suggest that the Ca₃(VO₄)₂:Sm³⁺ phosphor could be a good candidate for the orange emitting component for wLED applications.

Association of the Apolipoprotein A-I Gene Polymorphisms with Cardiovascular Disease Risk Factors and Atherogenic Indices in Patients from Assam, Northeast India

Cardiovascular disease (CVD) risk factors, and particularly decreased high density lipoprotein cholesterol (HDL-C) dyslipidemia are prevalent in Assam, India. This study was undertaken to investigate whether Apolipoprotein A-I (APOA1) gene polymorphisms (G-75A and C+83T) were associated with i) the risk for decreased HDL-C, and ii) other CVD risk factors, viz. serum lipids, atherogenic indices, obesity, and blood pressure (BP). A total of 649 subjects were screened, from which 200 eligible individuals, classified as case group with decreased HDL-C levels (100 subjects) and control group with normal HDL-C levels (100 subjects) were enrolled and genotyped using polymersase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. Lipid fractions [HDL-C, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), triglycerides (TG)] and atherogenic indices [Castelli's Risk Indices-I and -II (CRI-I and -II), non-HDL-C fraction, atherogenic index of plasma (AIP), atherogenic coefficient (AC)] were estimated. The G-75A and C+83T loci were not associated with decreased HDL-C risk. This was confirmed across different genetic models (dominant, recessive, additive and allelic). Association was also absent with BP and obesity. However, the G-75A locus was associated with LDL-C, whereas the C+83T locus was associated with TG and VLDL-C. Furthermore, these sites had effects on atherogenic indices. The rare A allele at the G-75A locus was associated with adverse CRI-I, CRI-II, non-HDL-C and AC values, while the major C allele at the C+83T locus was associated with adverse AIP values. Thus, the pro-atherogenic G-75A polymorphism and the anti-atherogenic C+83T polymorphism represent important genetic loci that modulate CVD risk factors in subjects from Assam.

Visible upconversion in Er3+/Yb3+ co-doped LaAlO3 phosphors

The Er³⁺ doped and Er³⁺/Yb³⁺ co-doped LaAlO₃ phosphors have been synthesized by the combustion method and characterized their structural, morphological, elemental, vibrational and optical properties. The optical absorption and upconversion properties of the synthesized phosphors have been studied. Upon co-doping Yb³⁺ ions into Er³⁺:LaAlO₃, the blue, green and red upconversion emissions of Er³⁺ ions have been enhanced about ~20, ~54 and ~22 times, under 978nm laser excitation. The observed upconversion emissions could be due to excited state absorption in Er³⁺:LaAlO_3, whereas energy transfer is dominant mechanism in Er³⁺/Yb³⁺:LaAlO₃ phosphors. The tuning in the color emitted from the synthesized phosphors towards the green region has been found due to incorporation of the Yb³⁺ ions. With increase in the pump power, the color emitted from the co-doped phosphor is not tuned significantly, showing its applicability in making the green display devices.

Association of Decreased High-Density Lipoprotein Cholesterol (HDL-C) With Obesity and Risk Estimates for Decreased HDL-C Attributable to Obesity: Preliminary Findings From a Hospital-Based Study in a City From Northeast India

BACKGROUND

Obesity is an important risk factor for decrease in high-density lipoprotein cholesterol (HDL-C) levels, which predisposes to cardiovascular diseases. But, the relative contribution of obesity toward decreased HDL-C and the risk estimates of decreased HDL-C attributable to obesity are unavailable. Such measures will help in understanding the extent by which the burden of decreased HDL-C can be reduced by tackling obesity.

OBJECTIVES

The objectives of this study were to ( a) determine the association between decreased HDL-C and obesity and ( b) estimate the attributable risk proportion (ARP) and population attributable risk proportion (PARP) for decreased HDL-C due to obesity.

METHODS

Body mass index (BMI) and waist circumference (WC) were measured as indices of overweight (or generalized obesity) and central obesity, respectively in 190 subjects (95 cases with low HDL-C and 95 healthy controls with normal HDL-C) from Guwahati city. Crude odds ratio (OR) and adjusted OR with 95% confidence interval (CI) were calculated along with the risk estimates (ARP and PARP).

RESULTS

People with overweight or generlized obesity (adjusted OR = 4.90, 95% CI = 3.59-6.68), and people with central obesity (adjusted OR = 3.33, 95% CI = 2.39-4.64) had significantly greater odds of developing decreased HDL-C. Among the exposed, 79.8% of the decreased HDL-C cases could be attributed to overweight (or generalized obesity), while 72.8% cases could be attributed to central obesity. In the overall population, the corresponding figures were 57.1% and 36%, respectively.

CONCLUSION

Decreased HDL-C is strongly associated with and largely attributable to obesity.

Single nucleotide polymorphisms of APOA1 gene and their relationship with serum apolipoprotein A-I concentrations in the native population of Assam

Background

There is a growing interest in the role of allelic variants of the APOA1 gene in relation to a number of disorders. We described two common polymorphisms of the APOA1 gene, G-75A and C+83T and investigated their potential influence on the serum apolipoprotein A-I (apo A-I) levels in the native population of Assam — a region that is ethnically distinct and from where no information is hitherto available.

Methods

Blood samples were collected from 150 healthy volunteers. Apo A-I levels were estimated by immunoturbidometry. Genotyping was done by a PCR-RFLP method that involved DNA extraction from whole blood, followed by polymerase chain reaction and digestion of the PCR product by MspI restriction enzyme, and analysis of fragment sizes in 12% polyacrylamide gel.

Results

The GG variant at G-75A locus and CC variant at C+83T locus were the most prevalent. GG/CC was the most common combination. Homozygous TT genotype was not detected in any of the subjects. The rare allele frequencies for the G-75A and C+83T sites were found to be 0.22 and 0.06 respectively, which significantly differed from those reported in some other populations in neighbouring regions. Serum apo A-I concentrations did not vary significantly across the detected genotypes. These findings were consistent in both sexes.

Conclusion

We described the distribution of the G-75A and C+83T polymorphisms of the APOA1 gene in the population of Assam for the first time. These polymorphisms were not found to directly influence apo A-I concentrations in this population either individually or synergistically.

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The G-75A and C + 83T polymorphisms of the APOA1 gene are described for the first time in the native population of Assam, north-east India.

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The minor allelic frequencies of G-75A and C + 83T differ significantly from some populations in the adjoining regions.

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The G-75A and C + 83T polymorphisms do not influence the serum apolipoprotein A-I levels in the current population.

Variation in Lipid Profile Across Different Patterns of Obesity - Observations from Guwahati, Assam

BACKGROUND

Obesity adversely affects cardiovascular health is known. But, data is few in this regard from Assam, northeast India. The serum lipid profile is performed for cardio-metabolic status assessment.

AIM

The aim of the study was to investigate variation in serum lipids across different obesity patterns in an urban population from Assam.

MATERIALS AND METHODS

Two hundred subjects were classified by WC (waist circumference) and BMI (body mass index) values into four groups as follows: Group I (normal WC, normal BMI), Group II (normal WC, increased BMI), Group III (increased WC, normal BMI) and Group IV (increased WC, increased BMI). WC and BMI served as measures of central and generalized obesity respectively. Lipid profile was measured using VITROS 5600 Autoanalyser, and compared across these groups. Multivariate analyses were performed separately for males and females to confirm the results of univariate analyses.

RESULTS

WC and BMI exhibited significant correlations with different lipid parameters. Group IV individuals had the most abnormal lipid profile values, while, Group I individuals had the most normal values. Group II and Group III individuals had intermediate values. BMI was independently associated with serum triglycerides in both males and females. WC was independently associated with high density lipoprotein cholesterol in females.

CONCLUSION

The lipid values varied significantly across different obesity patterns. Serum lipid concentrations were strongly influenced by anthropometric indices of obesity in both sexes. Presence of both central and generalized obesity led to greater abnormalities in lipid profile than presence of central or generalized obesity alone.

A Study on Atherogenic Indices of Pregnancy Induced Hypertension Patients as Compared to Normal Pregnant Women

INTRODUCTION

Pregnancy induced hypertension (PIH) includes Gestational hypertension, Pre-eclampsia and Eclampsia and is one of the most common obstetric complication. Worldwide about 76,000 pregnant women die each year from pre-eclampsia and related hypertensive disorders. The aetiology of Pre-eclampsia is unknown but it is thought to be related to abnormal development of placenta. Several studies have shown the presence of reduced endothelial function in pre-eclamptic pregnancy. Endothelial dysfunction is also a feature of atherosclerosis.

AIM

To assess fasting lipid profile and atherogenic indices in women diagnosed with pre-eclampsia as well as in women with normal pregnancy and to correlate the findings of pre-eclamptic women with that of normal pregnant women, in an attempt to utilize the data for the development of a new clinical approach for early recognition and prevention of risk of future cardiovascular diseases in women with PIH.

MATERIALS AND METHODS

This case-control study was conducted on 50 pre-eclampsia patients who were in third trimester of pregnancy (Case group). A control group of 50 age and gestational age matched normal pregnant women was taken. Strict inclusion and exclusion criteria were followed. Fasting Lipid profile parameters were assessed and used to calculate the atherogenic indices namely Atherogenic index of plasma (AIP), Cardiac risk ratio (CRR) and Atherogenic coefficient (AC). Statistical Analysis was done by using student's t-test. Mann-Whitney U-test was used wherever applicable and correlations between the variables were estimated by Pearson's correlation coefficients.

RESULTS

There was an extremely significant (p<0.0001) increase in Atherogenic indices (AIP, CRR and AC) in case group as compared to the control group. A positive and significant correlation of systolic blood pressure with AIP (r=0.3583), CRR (r=0.3137), AC (r=0.3193) was found in cases. There was a positive and significant correlation between gestational age and atherogenic indices in the case group.

CONCLUSION

Women with pre-eclampsia present abnormalities in lipid profile and these lipids turn out to be a risk factor for cardiovascular complications. Evaluation of the atherogenic indices during pregnancy may help prevent this risk.

Serum hsCRP: A Novel Marker for Prediction of Cerebrovascular Accidents (Stroke)

INTRODUCTION AND OBJECTIVES

Strokes are caused by disruption of the blood supply to the brain. This may result from either blockage or rupture of a blood vessel. Yearly 15 million people worldwide suffer a stroke. India ranks second worldwide in terms of deaths from stroke. The incidence of stroke increases with age affecting the economically productive middle aged population. Hypertension and male sex are other risk factors for stroke. C-Reactive Protein (CRP) is an acute phase protein whose concentration rises in blood following inflammation. Formerly, assays for CRP detected its rise only after significant inflammation. However, recently developed high sensitivity assays (hsCRP) enable the measurement of CRP in individuals who are apparently healthy. Several studies indicate that hsCRP is elevated in individuals who are at risk of developing Coronary Artery Disease or Cerebrovascular events, the elevation may be found years before the first detection of vascular problems. In the absence of other biochemical markers, the present study aimed to evaluate the predictive and diagnostic role of hsCRP in stroke.

MATERIALS AND METHODS

The study consisted of 50 patients of acute stroke admitted in Gauhati Medical College and Hospital. The control population consisted of two groups - 50 age and sex matched controls with hypertension (Hypertensive control group) and 50 age and sex matched controls with no obvious disease constituted the Normal control group. hsCRP levels were measured in all the groups and compared statistically.

CONCLUSION

hsCRP is an acute phase reactant whose concentration rises in stroke as well as in those at risk. The rise may be identified even before the appearance of risk factors. Hence, hsCRP may be useful as a predictive and diagnostic marker in stroke.

Haemoglobin s interaction with Beta thalassaemia- a case report from assam, India

Interaction of Hb S with beta thalassaemia is being reported here as this type of case is rare. Hb S (β6 glu→val) is a genetic disorder which occurs due to beta globin gene mutation of haemoglobin. In India, the Hb S is prevalent in the central part, in the eastern, western and southern tribal belt regions and among the tea tribe communities of Assam. The Hb S carriers (Sickle cell trait) leads a normal life but the Sickle cell disease patients show certain clinical manifestation like joint pain, anaemia and jaundice. The HPLC report of the patient showed Compound heterozygous for Hb S- β thalassaemia. The complete blood count was measured in automated haematology analyser. Mutational pattern of the beta thalassaemia as well as the presence of Hb S gene was detected by PCR. The case showed severe clinical manifestations and transfusion was required due to inheritance of the IVS 1-5 G →C β- thalassaemia mutation with the Hb S gene.

Management of spasticity in adults: practical application of botulinum toxin

Spasticity, characterized by increased muscle tone, exaggerated stretch reflexes, and abnormal limb posture, is a common sequel of central nervous system pathology. Historically, medicinal treatments have been of limited efficacy. This review discusses the clinical features of spasticity, the functional and pathological consequences, and treatment. It reviews the most common patterns of spasticity encountered in the upper and lower limbs and focuses on focal treatment of spastic muscles with the three commercially available botulinum toxins Botox, Dysport, and Myobloc/NeuroBloc. It addresses practical details such as muscle selection and identification, drug dilution, and doses.

Management of spasticity in adults: practical application of botulinum toxin

Spasticity, characterized by increased muscle tone, exaggerated stretch reflexes, and abnormal limb posture, is a common sequel of central nervous system pathology. Historically, medicinal treatments have been of limited efficacy. This review discusses the clinical features of spasticity, the functional and pathological consequences, and treatment. It reviews the most common patterns of spasticity encountered in the upper and lower limbs and focuses on focal treatment of spastic muscles with the three commercially available botulinum toxins Botox, Dysport, and Myobloc/NeuroBloc. It addresses practical details such as muscle selection and identification, drug dilution, and doses.

Optimal drug therapy and therapeutic drug monitoring after spinal cord injury: a population-specific approach

Study of the clinical pharmacology of SCI has revealed population-specific patterns of drug metabolism and disposition. PD/PK profiles reflect the changed physiology associated with SCI and correlate well with the neurologic or anatomic level and the magnitude and completeness of the injury. The greatest value of SCI PK/PD profiles lies in their use in developing criteria and strategies for the optimal prescribing of drugs and in therapeutic drug monitoring. Patients with SCI, acute or long-standing, comprise a therapeutically unique and distinct population. Rational, efficacious, and cost-effective approaches to drug development and pharmacotherapy in spinal cord-injured patients can only come about when population-specific PK/PD behavior is incorporated early into the drug development process and used to develop safe, effective therapeutic guidelines.

Absorption characteristics of sustained-release 4-aminopyridine (fampridine SR) in patients with chronic spinal cord injury

Fampridine SR (4-aminopyridine) is a potassium channel-blocking drug currently being investigated for its therapeutic efficacy in ameliorating central conduction deficits due to demyelination in patients with spinal cord injury (SCI). The present open-label pharmacokinetic trial examined the absorption characteristics of a sustained-release form of the drug in 25 SCI subjects with chronic incomplete injuries. The overall group mean Cmax of 27.7 +/- 6.2 ng/mL occurred at a tmax of 3.4 +/- 1.4 hours. AUC0-12 was 210.5 +/- 49.5 ng/mL.h. For paraplegics, AUCtmax was 76.02 +/- 33.28 and for tetraplegics was significantly less at 51.25 +/- 20.36 (p = 0.037). A statistically significant difference in the initial rate and extent of absorption, but not in total 4-AP bioavailability over the 12-hour study period, was evident between tetraplegic patients, 0.60 +/- 0.23, and paraplegic patients, 0.39 +/- 0.14 (p = 0.02). There was a linear correlation (p < 0.05) between the neurological level of injury and Cmax/AUCtmax. These results confirm and extend previous observations of different rates of drug absorption among SCI patients with lesions above and below the sympathetic outflow (T6) and provide evidence of the absorption characteristics of this sustained-release form of 4-aminopyridine, which is helpful for optimal dosing.

Safety and efficacy of 4-aminopyridine in humans with spinal cord injury: a long-term, controlled trial

STUDY OBJECTIVE

To determine the effects of the long-term administration of 4-aminopyridine (4-AP) on sensorimotor function in humans with long-standing spinal cord injury (SCI).

DESIGN

Randomized, open-label, active-treatment control, dosage-blinded study.

SETTING

University-affiliated, tertiary-level care, Department of Veterans Affairs Medical Center.

PATIENTS

Twenty-one healthy men and women outpatients suffering from traumatic SCI (14 tetraplegic, 7 paraplegic) for 2 years or more.

INTERVENTIONS

Dosages of an immediate-release formulation of 4-AP were titrated. At 3 months, 16 subjects were receiving 4-AP 30 mg/day (high dose); 5 subjects were receiving 4-AP 6 mg/day (low dose) and served as an active-treatment control group.

MEASUREMENTS AND MAIN RESULTS

Composite motor and sensory scores had statistically significant increases at 3 months. Maximal expiratory pressure, maximal inspiratory pressure, forced vital capacity, and forced expiratory volume in 1 second showed clinically meaningful and/or statistically significant increases among patients receiving 4-AP 30 mg/day. These subjects also had significant decreases in spasticity (modified Ashworth Scale). Serial biochemical profiles and electroencephalographs were unchanged from baseline, and no clinically significant drug toxicity was encountered.

CONCLUSIONS

Long-term oral administration of immediate-release 4-AP was associated with improvement in and recovery of sensory and motor function, enhanced pulmonary function, and diminished spasticity in patients with long-standing SCI. 4-Aminopyridine appears to be safe and relatively free from toxicity when administered orally over 3 months. Each patient who received immediate-release 4-AP 30 mg/day showed a response in one or more of the outcome measures.