Predicting dosing advantages of factor VIIa variants with altered tissue factor-dependent and lipid-dependent activities

BACKGROUND

Recombinant factor VIIa (rFVIIa) is an FX-cleaving coagulation enzyme licensed for the treatment of bleeding episodes in hemophiliacs with inhibitory antibodies. Even though the optimal dosing and comparative dose efficacy of rFVIIa remain poorly understood, genetic or chemical modifications of rFVIIa have been proposed, with the goal of achieving faster and longer hemostatic action. No ongoing trial is currently comparing rFVIIa variants with each other.

OBJECTIVES AND METHODS

We used mathematical modeling to compare the pharmacokinetics, dose-response (pharmacodynamics) and dose-effect duration (pharmacokinetics/pharmacodynamics) of rFVIIa variants to predict their optimal doses. The pharmacodynamic (PD) model of FXa generation by FVIIa in complexes with tissue factor (TF) and procoagulant lipids (PLs) was validated against published ex vivo and in vitro thrombin generation (TG) experiments. To compare variants' safety profiles, the highest non-thrombogenic doses were estimated from the clinical evidence reported for the licensed rFVIIa product.

RESULTS

The PD model correctly described the biphasic TF-dependent and PL-dependent dose response observed in TG experiments in vitro. The pharmacokinetic/PD simulations agreed with published ex vivo TG data for rFVIIa and the BAY 86-6150 variant, and explained the similar efficacies of a single dose of 270 μg kg(-1) (as reported in the literature) and repeated doses of 90 μg kg(-1) of unmodified rFVIIa. The duration of the simulated hemostatic effect after a single optimal dose was prolonged for rFVIIa variants with increased TF affinity or extended half-lives, but not for those with modulated PL activity.

CONCLUSIONS

Some modifications of the rFVIIa molecule may not translate into a prolonged hemostatic effect.

Regio-selective chemical-enzymatic synthesis of pyrimidine nucleotides facilitates RNA structure and dynamics studies

Isotope labeling has revolutionized NMR studies of small nucleic acids, but to extend this technology to larger RNAs, site-specific labeling tools to expedite NMR structural and dynamics studies are required. Using enzymes from the pentose phosphate pathway, we coupled chemically synthesized uracil nucleobase with specifically (13) C-labeled ribose to synthesize both UTP and CTP in nearly quantitative yields. This chemoenzymatic method affords a cost-effective preparation of labels that are unattainable by current methods. The methodology generates versatile (13) C and (15) N labeling patterns which, when employed with relaxation-optimized NMR spectroscopy, effectively mitigate problems of rapid relaxation that result in low resolution and sensitivity. The methodology is demonstrated with RNAs of various sizes, complexity, and function: the exon splicing silencer 3 (27 nt), iron responsive element (29 nt), Pro-tRNA (76 nt), and HIV-1 core encapsidation signal (155 nt).

Superior vena cava obstruction (SVCO) in patients with advanced non small cell lung cancer (NSCLC)

INTRODUCTION

To report on prognostic and treatment factors influencing the response of SVCO and related survival outcomes in advanced non small cell lung cancer.

MATERIAL AND METHODS

From November 2008 through December 2011, 18 consecutively diagnosed NSCLC patients with SVCO were included in this study. The patient, tumor and treatment related factors were analyzed. Median overall survival (OS), Kaplan -Meier survival plots, T-test, Cox Proportional Hazards models were generated by multiple covariates (MVA) and analyzed on SPSS software (version 19.0; SPSS, Inc., Chicago, IL).

RESULTS

Thirteen patients (72%) had presented with SVCO before the pathological diagnosis of underlying lung malignancy, while 5 (28%) progressed to SVCO after initiating treatment with chemotherapy. Twelve (68%) patients achieved subjective relief from the obstruction at the completion of palliative radiation therapy. Treating oncologists preferred 4 Gy per fraction in 11 (62%), while the median biologically equivalent dose delivered was 28 Gy. Six (33%) patients received chemotherapy during the course of treatment. Median OS of the entire cohort was 3±1.85mths and 1-year survival rate of 7%. Univariate analysis confirmed that SVCO patients with good performance score (p=0.02), and partial response to chemotherapy (p= 0.001) have superior OS. However, Cox regression modeling for MVA demonstrated only good performance SVCO patients (p = 0.05) have a better OS.

CONCLUSION

RT effectively relieves SVCO but overall poor survival associated in our clinical scenario needs to be improved with multimodality approach. Adjuvant chemotherapy is to be considered after initial radiation therapy in good performance patients.

KEYWORDS

superior vena cava obstruction (SVCO), radiation therapy, chemotherapy, non small cell lung cancer (NSCLC), BED (biologically equivalent dose).

Hair: an unusual foreign body in airways presenting with haemoptysis in an adult patient

Haemoptysis is defined as expectoration of blood originating from the lungs or tracheo-bronchial tree. It is attributed to various causes like tuberculosis, bronchiectasis, lung cancer, mycetoma, foreign bodies etc. Various types of foreign bodies have been reported in the literature. We report the case of an adult female patient who presented with an episode of haemoptysis (150 mL) in whom flexible fibreoptic bronchoscopy revealed a single long hair at the carina going to left main bronchus. Following successful removal of this hair there were no further episodes of haemoptysis and the patient manifested clinical and radiological improvement.

Application of small-angle neutron scattering to the study of forces between magnetically chained monodisperse ferrofluid emulsion droplets

The optical magnetic chaining technique (MCT) developed by Leal-Calderon, Stora, Mondain-Monval, Poulin & Bibette [Phys. Rev. Lett.(1994),72, 2959–2962] allows precise measurements of force profiles between droplets in monodisperse ferrofluid emulsions. However, the method lacks anin situdetermination of droplet size and, therefore, requires a combination of separately acquired measurements of droplet chain periodicityversusan applied magnetic field from optical Bragg scattering and droplet diameter inferred from dynamic light scattering (DLS) to recover surface force–distance profiles between the colloidal particles. Compound refractive lens (CRL) focused small-angle neutron scattering (SANS) MCT should result in more consistent measurements of droplet size (form factor measurements in the absence of field) and droplet chaining period (from structure factor peaks when the magnetic field is applied), and, with access to shorter length scales, extend force measurements to closer approaches than possible by optical measurements. This article reports on CRL-SANS measurements of monodisperse ferrofluid emulsion droplets aligned in straight chains by an applied field perpendicular to the incident beam direction. Analysis of the scattering from the closely spaced droplets required algorithms that carefully treated resolution and its effect on mean scattering vector magnitudes in order to determine droplet size and chain periods to sufficient accuracy. At lower applied fields, scattering patterns indicate structural correlations transverse to the magnetic field direction owing to the formation of intermediate structures in early chain growth.

Prevalence of hand disorders in type 2 diabetes mellitus and its correlation with microvascular complications

Background:

Physicians have long recognized the association between diabetes mellitus and several pathologic conditions of the hand. The most commonly recognized maladies are limited joint mobility (LJM), Dupuytren's disease (DD), trigger finger (TF), and carpal tunnel syndrome (CTS). Incidence of these hand disorders has increased in the setting of diabetes. Collectively, these are described as diabetic hand syndrome.

Aim:

The aims were to find out the prevalence of hand disorders in diabetic patients, and to study the relation of these hand disorders with microvascular complications.

Subjects and Methods:

This is an observational cross-sectional case-control study done over a period of 1 year Patients of type 2 DM, of age < 65 years, who visited Gandhi Memorial Hospital, Lucknow were enrolled and were described as cases. Age- and sex-matched nondiabetic individuals were taken in the control group. The data were analyzed using software SPSS. SPSS Inc. Released 2008. SPSS Statistics for Windows, Version 17.0. Chicago: SPSS Inc. Means and standard deviations were computed; the Student t-test and Chi-square (χ²) test were used as appropriate.

Results:

A total of 400 subjects were studied, 200 each in the case and control groups. Of total 200 diabetic patients, 30% (60/200) patients had neuropathy, 37.5% (75/200) had nephropathy, and 44.5% (89/200) patients had retinopathy. In the study population, 67% patients were having one or more hand disorders, in which LJM was found in 40.5% (81/200) patients, DD was found in 19% (38/200) patients, TF in 16.5% (33/200), and CTS in 14% (28/200) patients.

Conclusions:

This study shows a high prevalence of hand disorders in diabetic patients and also correlates with the duration of type 2 DM, LJM being the most common hand disorder and more common in patients who have microvascular complications.

PANNOTATOR: an automated tool for annotation of pan-genomes

Due to next-generation sequence technologies, sequencing of bacterial genomes is no longer one of the main bottlenecks in bacterial research and the number of new genomes deposited in public databases continues to increase at an accelerating rate. Among these new genomes, several belong to the same species and were generated for pan-genomic studies. A pan-genomic study allows investigation of strain phenotypic differences based on genotypic differences. Along with a need for good assembly quality, it is also fundamental to guarantee good functional genome annotation of the different strains. In order to ensure quality and standards for functional genome annotation among different strains, we developed and made available PANNOTATOR (http://bnet.egr.vcu.edu/iioab/agenote.php), a web-based automated pipeline for the annotation of closely related and well-suited genomes for pan-genome studies, aiming at reducing the manual work to generate reports and corrections of various genome strains. PANNOTATOR achieved 98 and 76% of correctness for gene name and function, respectively, as result of an annotation transfer, with a similarity cut-off of 70%, compared with a gold standard annotation for the same species. These results surpassed the RAST and BASys softwares by 41 and 21% and 66 and 17% for gene name and function annotation, respectively, when there were reliable genome annotations of closely related species. PANNOTATOR provides fast and reliable pan-genome annotation; thereby allowing us to maintain the research focus on the main genotype differences between strains.

Formulation and optimization of mucoadhesive nanodrug delivery system of acyclovir

Acyclovir is an antiviral drug used for the treatment of herpes simplex virus infections, with an oral bioavailability of only 10-20% [limiting absorption in gastrointestinal tract to duodenum and jejunum] and half-life of about 3 h, and is soluble only at acidic pH (pKa 2.27). Mucoadhesive polymeric nanodrug delivery systems of acyclovir have been designed and optimized using 2(3) full factorial design. Poly (lactic-co-glycolic acid) (PLGA) (50:50) was used as the polymer along with polycarbophil (Noveon AA-1) as the mucoadhesive polymer and pluronic F68 as the stabilizer. From the preliminary trials, the constraints for independent variables X(1) (amount of PLGA), X(2) (amount of pluronic F68) and X(3) (amount of polycarbophil) have been fixed. The dependent variables that were selected for study were particle size (Y(1)), % drug entrapment (Y(2)) and % drug release in 12 h (Y(3)). The derived polynomial equations were verified by check point formulation. The application of factorial design gave a statistically systematic approach for the formulation and optimization of nanoparticles with the desired particle size, % drug release and high entrapment efficiency. Drug: Polymer ratio and concentration of stabilizer were found to influence the particle size and entrapment efficiency of acyclovir-loaded PLGA nanoparticles. The release was found to follow Fickian as well as non-Fickian diffusion mechanism with zero-order drug release for all batches. In vitro intestinal mucoadhesion of nanoparticles increased with increasing concentration of polycarbophil. These preliminary results indicate that acyclovir-loaded mucoadhesive PLGA nanoparticles could be effective in sustaining drug release for a prolonged period.

Weight loss for reduction of proteinuria in diabetic nephropathy: Comparison with angiotensin-converting enzyme inhibitor therapy

Reduction of weight in obese type 2 diabetes mellitus (T2DM) individuals is emerging as a significant strategy in the reduction of proteinuria in diabetic nephropathy along with control of hyperglycemia, hypertension, and dyslipidemia. The objective was to evaluate the reduction in 24-h proteinuria in T2DM patients with nephropathy by weight loss, with conventional therapy (angiotensin-converting enzyme [ACE] inhibitors) as the control arm. A prospective, randomized controlled trial was conducted between June 2010 and May 2011. T2DM patients with confirmed nephropathy by 24-h urinary protein estimation with a body mass index (BMI) of >25 kg/m² were studied. Patients who had nondiabetic nephropathy, uncontrolled hypertension (>125/75 mmHg) irrespective of antihypertensive drugs, excess weight due to edema or obesity due to other specific diseases, alcoholics, smokers, and patients who were on hemodialysis were excluded from the study. The patients were divided into three groups, namely, group A, patients on ACE inhibitor therapy; group B, patients on lifestyle modifications for weight loss; and group C, patients on an antiobesity drug (orlistat) and lifestyle modifications. At the end of 6 months, all the three groups were compared. Data were analyzed using software SPSS version 15.0. This study encompassed a total of 88 patients; 12 patients were dropped during the study period and 76 (group A: 22, group B: 23, and group C: 31) patients remained. The mean age of the patients was 58.36 ± 10.87 years (range: 30-70 years). At baseline, age, gender, mean BMI, waist-to-hip ratio (WHR), and 24-h proteinuria did not vary significantly among the three groups. At 6 months, the mean BMI significantly decreased in group C (P < 0.001) compared to that in the other two groups. Among the parameters BMI and WHR, the proportional form of BMI correlated well with the degree of reduction in proteinuria (r = 0.397, P = 0.01). Reduction in weight using lifestyle modifications and antiobesity drugs might improve renal function and proteinuria safely as observed in obese patients with diabetic nephropathy.

Can Metabolic Factors be used Prognostically for Short-Term Mortality in HIV-Infected Patients?

BACKGROUND

Metabolic abnormalities are common throughout the course of human immunodeficiency virus (HIV) infection and may occur either due to HIV infection or as a result of side effects of antiretroviral therapy. It has been established that dyslipidemia and dysglycemia associated with HIV disease reduce the long-term survival of the patients, but their role for predicting prognosis of short-term mortality in HIV patients is unknown.

AIM

To study dyslipidemia and dysglycemia as a prognostic indicator for short-term mortality (<3 months) in HIV patients.

SUBJECTS AND METHODS

An observational, prospective study was conducted at a tertiary care center over a period of 6 months. Consecutive HIV-positive patients hospitalized (both, HIV status known prior to hospitalization and the diagnosis made for the first time at admission) in medical wards from March to May 2010 were studied. All patients had their random blood sugars, fasting blood sugars (if possible), fasting lipid profile, and cluster of differentiation 4 (CD4) counts tested at the time of enrollment. The patients were followed for a period of 3 months, at the end of which they were categorized as survivors and non-survivors, and the demographic, clinical, and investigational parameters were compared between the above groups. Data was analyzed by applying Mann-Whitney U test, two sample t-test, Fisher-Exact test, and stepwise logistic regression analysis of significance, using the computer-based program, Stata, version 11.1.

RESULTS

A total of 82 patients were enrolled for the study of which 64 (78.05%) were males and 18 (21.95%) were females, with a mean (SD) age of 34.00 (7.0) years. The mean CD4 count was 206.23 (129.5) cells/mm(3). The overall mortality within 3 months was 20.7% (17/82). Mycobacterium tuberculosis as opportunistic infection was found in 42 patients, out of which 13 expired (P=0.02). Patients with low high-density lipoprotein (HDL) and hypertriglyceridemia (adjusted OR = 22.92, P value = 0.03, adjusted OR = 3.4, P value = 0.02, respectively) had high likelihood of mortality within 3 months.

CONCLUSIONS

Low HDL and hypertriglyceridemia also appear to be promising short-term mortality markers in HIV patients apart from established factors like low CD4 counts, co-morbid conditions, and opportunistic infections like M. tuberculosis infection. This study warrants further studies with a larger sample size to establish HDL and triglyceride as markers of disease progression and short-term mortality in HIV-infection.

Study on Clinico-Laboratory Profile of Children with Scrub Typhus

Scrub typhus is an acute, febrile, infectious illness caused by Orientia (formerly Rickettsia) tsutsugamushi,an obligate intracellular gram-negative bacterium. Humans are accidental hosts in this zoonotic disease.The present retrospective study describes clinical profile of the children hospitalized in hospital with Scrub Typhus infection during period 2010-2011. 19 hospitalized children with clinical features suggestive of Rickettsial disease (fever, generalized rash) who tested ELISA positive for IgM against Scrub Typhus were included in the present study between the age of 1 years and 15 years. All children presented with fever (100%). 42.10% had lymphadenopathy, 47.36% had eschar and 57.89% patients had cough. 26.31, 21.05%, 10.52%, had hepatomegaly, pain abdomen, and respiratory distress and gastrointestinal bleed respectively. All of the children were investigated and treated with as per protocol. None of them died. We think that Rickettsial infection is not quite common in this region but study showed that it is not an uncommon entity and thus, high degree of suspicion, knowledge of geographical distribution and clinical features of Rickettsial disease helps in its early diagnosis and treatment. J Nepal Paediatr Soc 2012;32(2):187-192 doi: http://dx.doi.org/10.3126/jnps.v32i2.5683

Convergent functional genomics of schizophrenia: from comprehensive understanding to genetic risk prediction

We have used a translational convergent functional genomics (CFG) approach to identify and prioritize genes involved in schizophrenia, by gene-level integration of genome-wide association study data with other genetic and gene expression studies in humans and animal models. Using this polyevidence scoring and pathway analyses, we identify top genes (DISC1, TCF4, MBP, MOBP, NCAM1, NRCAM, NDUFV2, RAB18, as well as ADCYAP1, BDNF, CNR1, COMT, DRD2, DTNBP1, GAD1, GRIA1, GRIN2B, HTR2A, NRG1, RELN, SNAP-25, TNIK), brain development, myelination, cell adhesion, glutamate receptor signaling, G-protein-coupled receptor signaling and cAMP-mediated signaling as key to pathophysiology and as targets for therapeutic intervention. Overall, the data are consistent with a model of disrupted connectivity in schizophrenia, resulting from the effects of neurodevelopmental environmental stress on a background of genetic vulnerability. In addition, we show how the top candidate genes identified by CFG can be used to generate a genetic risk prediction score (GRPS) to aid schizophrenia diagnostics, with predictive ability in independent cohorts. The GRPS also differentiates classic age of onset schizophrenia from early onset and late-onset disease. We also show, in three independent cohorts, two European American and one African American, increasing overlap, reproducibility and consistency of findings from single-nucleotide polymorphisms to genes, then genes prioritized by CFG, and ultimately at the level of biological pathways and mechanisms. Finally, we compared our top candidate genes for schizophrenia from this analysis with top candidate genes for bipolar disorder and anxiety disorders from previous CFG analyses conducted by us, as well as findings from the fields of autism and Alzheimer. Overall, our work maps the genomic and biological landscape for schizophrenia, providing leads towards a better understanding of illness, diagnostics and therapeutics. It also reveals the significant genetic overlap with other major psychiatric disorder domains, suggesting the need for improved nosology.