SARS-CoV-2 antigen detection in deceased bodies: implications for infection prevention

Background & objectives

High transmissibility of the SARS-CoV-2 has significant implications on healthcare workers' safety, preservation, handling, transportation and disposal of the deceased bodies. The objective of this study was to detect SARS-CoV-2 antigen in nasopharyngeal samples and its implications in handling and care of COVID-19 deceased bodies.

Methods

A study was conducted at a dedicated COVID-19 centre on deceased individuals from April to December 2020. Rapid antigen test (RAT) and reverse transcription (RT)-PCR was compared on all the SARS-CoV-2 positive cadavers recruited in the study.

Results

A total of 115 deceased individuals were included in the study. Of these, 79 (68.7%) were male and 36 (31.3%) were female and majority were in the age group of 51-60 yr [31 (27%)]. SARS-CoV-2 antigen test was positive in 32 (27.8%) and negative in 83 (72.1%) individuals. The mean time interval between deaths to the sample collection was 13.2 h with interquartile range of eight to 20 h. Reverse transcription (RT)-PCR was used as the reference test and 24 (20.9%) cases were true positive; 93.6 per cent [95% confidence interval (CI) 88.8-98.4%] sensitivity, 45.2 per cent (95% CI 35.5-55%) specificity, 60.2 per cent (95% CI 50.6-69.8%) positive predictive value and 88.8 per cent (95% CI 82.7-95%) negative predictive value of antigen test was computed.

Interpretation & conclusions

SARS-CoV-2 antigen test was positive beyond 19 h in COVID-19 deceased individuals. Antigen test was found to be highly sensitive in the deceased. Patients, suspected of having died due to COVID-19, can be screened by this method. As infectiousness of the virus in the deceased bodies cannot be directly concluded from either the antigen or RT-PCR test, yet possible transmission cannot be completely ruled out. Strict infection control measures need to be followed during the handling and clearance of COVID-19 cadavers.

Cellulose synthesis complexes are homo-oligomeric and hetero-oligomeric in Physcomitrium patens

The common ancestor of seed plants and mosses contained homo-oligomeric cellulose synthesis complexes (CSCs) composed of identical subunits encoded by a single CELLULOSE SYNTHASE (CESA) gene. Seed plants use different CESA isoforms for primary and secondary cell wall deposition. Both primary and secondary CESAs form hetero-oligomeric CSCs that assemble and function in planta only when all the required isoforms are present. The moss Physcomitrium (Physcomitrella) patens has seven CESA genes that can be grouped into two functionally and phylogenetically distinct classes. Previously, we showed that PpCESA3 and/or PpCESA8 (class A) together with PpCESA6 and/or PpCESA7 (class B) form obligate hetero-oligomeric complexes required for normal secondary cell wall deposition. Here, we show that gametophore morphogenesis requires a member of class A, PpCESA5, and is sustained in the absence of other PpCESA isoforms. PpCESA5 also differs from the other class A PpCESAs as it is able to self-interact and does not co-immunoprecipitate with other PpCESA isoforms. These results are consistent with the hypothesis that homo-oligomeric CSCs containing only PpCESA5 subunits synthesize cellulose required for gametophore morphogenesis. Analysis of mutant phenotypes also revealed that, like secondary cell wall deposition, normal protonemal tip growth requires class B isoforms (PpCESA4 or PpCESA10), along with a class A partner (PpCESA3, PpCESA5, or PpCESA8). Thus, P. patens contains both homo-oligomeric and hetero-oligomeric CSCs.

Endoscopic Anterior Odontoid Screw Fixation for the Odontoid Fracture: A Cadaveric Pilot Study

Introduction

Anterior odontoid screw fixation technique for specific types of odontoid fracture has been proven to be an effective, yet challenging procedure because of threatened damage to the structures in the vicinity. There are few articles suggesting the role of percutaneous and endoscopic technique as an alternative approach to the standard microscopic way. This is the first cadaveric study using existing "EASY GO" endoscopic system-assisted odontoid screw placement.

Study Design

This was a cadaveric study.

Objective

The objective of the study is to use the endoscope as a safer minimally invasive approach than the standard microscopic anterior approach to odontoid.

Methodology

This is a pilot study on 10 fresh-frozen formalin-fixed adult human cadavers. The cadaver was positioned in a way to simulate reduced odontoid fracture. Tubular dilators were used to dock at C2-3 disk space after identifying the landmarks through the microscopic method. The EASY GO endoscopic system was then introduced, and a handheld drill was used to mark the entry point and pass the K-wire through the planned trajectory.

Results

No vascular or adjacent vital structures' injury was observed in any of the cadavers. The initial difficulty in attaining the alignment was overcome by the appropriate positioning of the scope.

Conclusions

Endoscopic-assisted technique for odontoid screw fixation shall provide a minimally invasive, safe, and easy surgery.

A cadaveric study on the rate of strain-dependent behavior of human anterior cruciate ligament

Purpose: Failure of anterior cruciate ligament often occurs in young sports personnel hampering their career. Such ACL ruptures are quite prevalent in sports such as soccer during dynamic loading which occurs at more than one rate of loading. In this work, a structural constitutive equation has been used to predict the forces acting on ACL for different rates of loading. Methods: Ligaments with distal femur and proximal tibia were subjected to tensile loading to avoid crushing of tissue ends and slipping at higher rates of strain. Custom designed cylindrical grippers were fabricated to clamp the distal femur and proximal tibial bony sections. To estimate parameters for the model, eighteen fresh cadaveric femur-ACL-tibia complex (FATC) samples were experimented on by pure tensile loading at three orders of rates of strain viz., 0.003, 0.03, and 0.3 s–1. The experimental force-elongation data was used to obtain parameters for De-Vita and Slaughter’s equation. The model was validated with additional tensile experiments. Results: Statistical analysis demonstrated failure stress, Young’s modulus and volumetric strain energy to vary significantly as a function of rate of strain. Midsection failure was observed only in samples tested at 0.03 s–1. Femoral or tibial insertion failure were observed in all other experiments irrespective of rate of strain. Conclusion: Human FATC samples were tensile tested to failure at three rates of strain using custom-designed cylindrical grippers. A structural model was used to model the data for the ACL behaviour in the linear region of loading to predict ligament behaviour during dynamic activities in live subjects.

A cadaveric study on the rate of strain-dependent behaviour of human anterior cruciate ligament

PURPOSE

Failure of anterior cruciate ligament often occurs in young sports personnel hampering their career. Such ACL ruptures are quite prevalent in sports such as soccer during dynamic loading which occurs at more than one rate of loading. In this work, a structural constitutive equation has been used to predict the forces acting on ACL for different rates of loading.

METHODS

Ligaments with distal femur and proximal tibia were subjected to tensile loading to avoid crushing of tissue ends and slipping at higher rates of strain. Custom designed cylindrical grippers were fabricated to clamp the distal femur and proximal tibial bony sections. To estimate parameters for the model, eighteen fresh cadaveric femur-ACL-tibia complex (FATC) samples were experimented on by pure tensile loading at three orders of rates of strain viz., 0.003, 0.03, and 0.3 s^-1. The experimental force-elongation data was used to obtain parameters for De-Vita and Slaughter's equation. The model was validated with additional tensile experiments.

RESULTS

Statistical analysis demonstrated failure stress, Young's modulus and volumetric strain energy to vary significantly as a function of rate of strain. Midsection failure was observed only in samples tested at 0.03 s^-1. Femoral or tibial insertion failure were observed in all other experiments irrespective of rate of strain.

CONCLUSION

Human FATC samples were tensile tested to failure at three rates of strain using custom-designed cylindrical grippers. A structural model was used to model the data for the ACL behaviour in the linear region of loading to predict ligament behaviour during dynamic activities in live subjects.

Design of orthogonal regulatory systems for modulating gene expression in plants

Agricultural biotechnology strategies often require the precise regulation of multiple genes to effectively modify complex plant traits. However, most efforts are hindered by a lack of characterized tools that allow for reliable and targeted expression of transgenes. We have successfully engineered a library of synthetic transcriptional regulators that modulate expression strength in planta. By leveraging orthogonal regulatory systems from Saccharomyces spp., we have developed a strategy for the design of synthetic activators, synthetic repressors, and synthetic promoters and have validated their use in Nicotiana benthamiana and Arabidopsis thaliana. This characterization of contributing genetic elements that dictate gene expression represents a foundation for the rational design of refined synthetic regulators. Our findings demonstrate that these tools provide variation in transcriptional output while enabling the concerted expression of multiple genes in a tissue-specific and environmentally responsive manner, providing a basis for generating complex genetic circuits that process endogenous and environmental stimuli.

Spinopelvic parameters in patients with lumbar degenerative disc disease, spondylolisthesis, and failed back syndrome: Comparison vis-à-vis normal asymptomatic population and treatment implications

Background:

Most of the literature on role of spinopelvic parameters in various lumbar spine pathologies has been based on studies done on Caucasian population.

Aims and Objectives:

The present study attempts to establish a database of measurements of the sagittal profile of spine in asymptomatic Indian population and their comparison with subjects having various lumbar spine pathologies.

Materials and Methods:

We performed a prospective case control study at All India Institute of Medical Sciences, New Delhi in which we enrolled 109 patients and 22 healthy asymptomatic subjects in 2 years from 2015 to 2017. All patients underwent standing lateral radiographs of the pelvis and the entire spine and various spino-pelvic parameters were measured using Surgimap software.

Results:

The mean Pelvic incidence (PI) in the asymptomatic individuals was 49.29 ± 5.95° which was significantly lower when compared with patients of chronic low backache (53.96 ± 9.47, P-<0.001), lumbar listhesis (59.4 ± 21.33, P-<0.001) and failed back surgery syndrome (56.7 ± 8.21, P-<0.001). The mean Pelvic Tilt (PT) in healthy subjects was 14.3±4.08° which was significantly lower when compared with patients of lumbar listhesis (23.35 ± 14.03, P-<0.001) and failed back surgery syndrome (22.8 ± 8.09, P-<0.001). Sacral slope (SS) and sagittal vertical axis (SVA) offset did not show any statistically significant difference. The mean Lumbar lordosis (LL) measured in healthy individuals was 42.5 ± 7.89° which was significantly lower when compared with patients of lumbar listhesis (46.24 ± 19.24, P-0.04) and failed back surgery syndrome (45.12 ± 6.87, P-0.05).

Conclusion:

PT and PI showed statistically significant difference in subjects having lumbar spondylolisthesis and failed back surgery syndrome as compared to healthy asymptomatic subjects.

Convergent evolution of hetero-oligomeric cellulose synthesis complexes in mosses and seed plants

In seed plants, cellulose is synthesized by rosette-shaped cellulose synthesis complexes (CSCs) that are obligate hetero-oligomeric, comprising three non-interchangeable cellulose synthase (CESA) isoforms. The moss Physcomitrella patens has rosette CSCs and seven CESAs, but its common ancestor with seed plants had rosette CSCs and a single CESA gene. Therefore, if P. patens CSCs are hetero-oligomeric, then CSCs of this type evolved convergently in mosses and seed plants. Previous gene knockout and promoter swap experiments showed that PpCESAs from class A (PpCESA3 and PpCESA8) and class B (PpCESA6 and PpCESA7) have non-redundant functions in secondary cell wall cellulose deposition in leaf midribs, whereas the two members of each class are redundant. Based on these observations, we proposed the hypothesis that the secondary class A and class B PpCESAs associate to form hetero-oligomeric CSCs. Here we show that transcription of secondary class A PpCESAs is reduced when secondary class B PpCESAs are knocked out and vice versa, as expected for genes encoding isoforms that occupy distinct positions within the same CSC. The class A and class B isoforms co-accumulate in developing gametophores and co-immunoprecipitate, suggesting that they interact to form a complex in planta. Finally, secondary PpCESAs interact with each other, whereas three of four fail to self-interact when expressed in two different heterologous systems. These results are consistent with the hypothesis that obligate hetero-oligomeric CSCs evolved independently in mosses and seed plants and we propose the constructive neutral evolution hypothesis as a plausible explanation for convergent evolution of hetero-oligomeric CSCs.

Adult brachial plexus injuries: Surgical strategies and approaches

Traumatic brachial plexus injuries are devastating injuries commonly affecting the young population and leading to significant socioeconomic losses to the society. The results of brachial plexus surgery have been severely disappointing in the past. However, several technological advancements and newer surgical techniques, especially the advent of distal nerve transfers over recent years, have led to a paradigm shift in the outcome of patients with these injuries. The best time window for surgery is the first 3 months after injury, and the next best time is the next 3 months. The timing is a crucial factor as the neuromuscular junctions degenerate in 20-24 months. The presence of spontaneous fibrillations in a muscle on electromyography is an indication of denervated yet vital muscle. The restoration of elbow flexion is a priority followed closely by restoration of shoulder abduction and stabilization. The various surgical strategies in brachial plexus injuries should be directed toward accomplishing this goal. The global avulsion injuries have a poor outcome because of very limited source of donors in such types of injury whereas the partial injuries have a remarkable outcome in a majority of cases. This article presents the reader with the guidelines and management algorithms of repair strategy and various surgical approaches utilized in the surgical treatment of brachial plexus injuries.

Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly

Like all higher organisms, plants have evolved in the context of a microbial world, shaping both their evolution and their contemporary ecology. Interactions between plant roots and soil microorganisms are critical for plant fitness in natural environments. Given this co-evolution and the pivotal importance of plant-microbial interactions, it has been hypothesized, and a growing body of literature suggests, that plants may regulate the composition of their rhizosphere to promote the growth of microorganisms that improve plant fitness in a given ecosystem. Here, using a combination of comparative genomics and exometabolomics, we show that pre-programmed developmental processes in plants (Avena barbata) result in consistent patterns in the chemical composition of root exudates. This chemical succession in the rhizosphere interacts with microbial metabolite substrate preferences that are predictable from genome sequences. Specifically, we observed a preference by rhizosphere bacteria for consumption of aromatic organic acids exuded by plants (nicotinic, shikimic, salicylic, cinnamic and indole-3-acetic). The combination of these plant exudation traits and microbial substrate uptake traits interact to yield the patterns of microbial community assembly observed in the rhizosphere of an annual grass. This discovery provides a mechanistic underpinning for the process of rhizosphere microbial community assembly and provides an attractive direction for the manipulation of the rhizosphere microbiome for beneficial outcomes.

Effect of preservation methods on tensile properties of human femur-ACL-tibial complex (FATC) - a cadaveric study on male subjects

PURPOSE

Deep freezing and storing in formalin are some of the common techniques of human tissue preservation. However, the preservation modes affect the biomechanical properties of the tissues. In this work, the effects of the above-stated preservation tech- niques are compared with that of fresh cadaveric samples.

METHODS

FATC samples from male cadavers of age between 60 and 70 years were tested under tensile loading at a strain rate of 0.8 s-1. Fourteen FATC samples from soft embalmed cadavers were preserved for 3 weeks by two methods: (a) 10% formalin and (b) deep freezing at -20 ° C followed by thawing. Seven FATC samples from fresh ca- davers were experimented as control samples. The results were evaluated by a two-stage statistical process of Kruskal-Wallis H test and Mann-Whitney U-test.

RESULTS

It was observed that the failure force of fresh cadavers was the highest while that of preserved samples were approximately half the value. Failure elongation of frozen samples exceeded fresh samples while formalin samples failed at lesser elongations. Higher incidence of tibial insertion point or mid-section failures were observed in fresh samples while the higher incidence of ruptures at femoral insertion point was observed in the two preservation methods.

CONCLUSION

Tensile properties of fresh tissues vary significantly from that of formalin preserved or frozen preserved samples.

Expression of heterologous xyloglucan xylosyltransferases in Arabidopsis to investigate their role in determining xyloglucan xylosylation substitution patterns

Putative XyG xylosyltransferases from Tropaeolum majus (nasturtium) and Solanum lycopersicum (tomato) homologous to characterized Arabidopsis genes were identified and shown to functionally complement Arabidopsis mutants lacking xyloglucan demonstrating they represent xyloglucan xylosyltransferases. Xyloglucan is a major hemicellulose in the plant cell wall and is important for the structural organization of the wall. The fine structure of xyloglucan can vary dependent on plant species and tissue type. Most vascular seed-bearing plants including Arabidopsis thaliana and nasturtium (Tropaeolum majus) have a xyloglucan structure, in which three out of four backbone glucosyl-residues are substituted with xylosyl-residues. In contrast, the xyloglucan found in plants of the Solanaceae family, which includes tomato (Solanum lycopersicum), is typically less xylosylated with only two of the four backbone glucosyl-residues substituted with xylosyl-residues. To investigate the genetics of xyloglucan xylosylation, candidate xyloglucan xylosyltransferase genes (XXTs) homologous to known A. thaliana XXTs were cloned from nasturtium and tomato. These candidate XXTs were expressed in the A. thaliana xxt1/2 double and xxt1/2/5 triple mutant, whose walls lack detectable xyloglucan. Expression of the orthologs of XXT5 resulted in no detectable xyloglucan in the transgenic A. thaliana plants, consistent with a lack of xyloglucan in the A. thaliana xxt1/2 double mutant. However, transformation of both the tomato and nasturtium orthologs of AtXXT1 and AtXXT2 resulted in the production of xyloglucan with a xylosylation pattern similar to wild type A. thaliana indicating that both SlXXT2 and TmXXT2 likely have xylosyltransferase activity. As the expression of the SlXXT2 did not result in xyloglucan with a decreased xylosylation frequency found in tomato, this gene is not responsible for the unique xylosylation pattern found in the solanaceous plants.

Synergistic epistasis of paraoxonase 1 (rs662 and rs85460) and apolipoprotein E4 genes in pathogenesis of Alzheimer's disease and vascular dementia

Genetic polymorphism and epistasis play a role in etiopathogenesis of Alzheimer's disease (AD) and vascular dementia (VaD). In this case-control study, a total of 241 patients were included in the study to see the effect of paraoxonase 1 (PON1; rs662 and rs85460) and apolipoprotein E (ApoE) genes in altering the odds of having AD and VaD along with serum PON and lipid profile. The presence of at least 1 variant allele of rs662, but not rs85460, increased the risk of having AD by 1.8-fold (95% confidence interval [CI]: 0.97-3.40) and VaD by 3.09-fold (95% CI: 1.4-6.9). The interaction between PON1 genes (rs662 and rs85460) and ApoE genes showed synergistic epistasis in altering the odds of significantly having both AD and VaD. On the other hand, low serum level of high-density lipoprotein and low level of serum PON activity were found associated significantly (P ≤ .001 in both cases) only in patients with VaD as compared to healthy control.

TRICHOME BIREFRINGENCE-LIKE27 affects aluminum sensitivity by modulating the O-acetylation of xyloglucan and aluminum-binding capacity in Arabidopsis

Xyloglucan (XyG) has been reported to contribute to the aluminum (Al)-binding capacity of the cell wall in Arabidopsis (Arabidopsis thaliana). However, the influence of O-acetylation of XyG, accomplished by the putative O-acetyltransferase TRICHOME BIREFRINGENCE-LIKE27 (TBL27 [AXY4]), on its Al-binding capacity is not known. In this study, we found that the two corresponding TBL27 mutants, axy4-1 and axy4-3, were more Al sensitive than wild-type Columbia-0 plants. TBL27 was expressed in roots as well as in leaves, stems, flowers, and siliques. Upon Al treatment, even within 30 min, TBL27 transcript accumulation was strongly down-regulated. The mutants axy4-1 and axy4-3 accumulated significantly more Al in the root and wall, which could not be correlated with pectin content or pectin methylesterase activity, as no difference in the mutants was observed compared with the wild type when exposed to Al stress. The increased Al accumulation in the wall of the mutants was found to be in the hemicellulose fraction. While the total sugar content of the hemicellulose fraction did not change, the O-acetylation level of XyG was reduced by Al treatment. Taken together, we conclude that modulation of the O-acetylation level of XyG influences the Al sensitivity in Arabidopsis by affecting the Al-binding capacity in the hemicellulose.

The Cellulase KORRIGAN Is Part of the Cellulose Synthase Complex

Plant growth and organ formation depend on the oriented deposition of load-bearing cellulose microfibrils in the cell wall. Cellulose is synthesized by a large relative molecular weight cellulose synthase complex (CSC), which comprises at least three distinct cellulose synthases. Cellulose synthesis in plants or bacteria also requires the activity of an endo-1,4-β-d-glucanase, the exact function of which in the synthesis process is not known. Here, we show, to our knowledge for the first time, that a leaky mutation in the Arabidopsis (Arabidopsis thaliana) membrane-bound endo-1,4-β-d-glucanase KORRIGAN1 (KOR1) not only caused reduced CSC movement in the plasma membrane but also a reduced cellulose synthesis inhibitor-induced accumulation of CSCs in intracellular compartments. This suggests a role for KOR1 both in the synthesis of cellulose microfibrils and in the intracellular trafficking of CSCs. Next, we used a multidisciplinary approach, including live cell imaging, gel filtration chromatography analysis, split ubiquitin assays in yeast (Saccharomyces cerevisiae NMY51), and bimolecular fluorescence complementation, to show that, in contrast to previous observations, KOR1 is an integral part of the primary cell wall CSC in the plasma membrane.

Serum folic acid and RFC A80G polymorphism in Alzheimer's disease and vascular dementia

Low level of vitamin B12 and folic acid has been reported to play an important role in the pathogenesis of Alzheimer's disease (AD) and vascular dementia (VaD). Serum folic acid and vitamin B12 were assayed in 80 AD and 50 VaD cases and in 120 healthy controls. The reduced folate carrier (RFC1) gene, rs1051266, which encodes the RFC 1, protein was analyzed for polymorphism by polymerase chain reaction-restriction fragment length polymorphism. It was observed that the patients having folic acid <8.45 ng/mL had 2.4 (95% confidence interval [CI]: 1.4-4.5) times higher odds of having AD and 2.1 (95% CI: 1.1-4.2) times higher odds of having VaD than patients having folic acid ≥8.45 ng/mL. Serum vitamin B12 level did not show any such statistically significant effect in altering the odds. No direct association was found between variant (G) allele or genotype of rs1051266 with AD and VaD cases. On serum folate level no association was observed with gene polymorphism.

Hemicellulose biosynthesis

One major component of plant cell walls is a diverse group of polysaccharides, the hemicelluloses. Hemicelluloses constitute roughly one-third of the wall biomass and encompass the heteromannans, xyloglucan, heteroxylans, and mixed-linkage glucan. The fine structure of these polysaccharides, particularly their substitution, varies depending on the plant species and tissue type. The hemicelluloses are used in numerous industrial applications such as food additives as well as in medicinal applications. Their abundance in lignocellulosic feedstocks should not be overlooked, if the utilization of this renewable resource for fuels and other commodity chemicals becomes a reality. Fortunately, our understanding of the biosynthesis of the various hemicelluloses in the plant has increased enormously in recent years mainly through genetic approaches. Taking advantage of this knowledge has led to plant mutants with altered hemicellulosic structures demonstrating the importance of the hemicelluloses in plant growth and development. However, while we are on a solid trajectory in identifying all necessary genes/proteins involved in hemicellulose biosynthesis, future research is required to combine these single components and assemble them to gain a holistic mechanistic understanding of the biosynthesis of this important class of plant cell wall polysaccharides.

Complexes with mixed primary and secondary cellulose synthases are functional in Arabidopsis plants

In higher plants, cellulose is synthesized by so-called rosette protein complexes with cellulose synthases (CESAs) as catalytic subunits of the complex. The CESAs are divided into two distinct families, three of which are thought to be specialized for the primary cell wall and three for the secondary cell wall. In this article, the potential of primary and secondary CESAs forming a functional rosette complex has been investigated. The membrane-based yeast two-hybrid and biomolecular fluorescence systems were used to assess the interactions between three primary (CESA1, CESA3, CESA6), and three secondary (CESA4, CESA7, CESA8) Arabidopsis (Arabidopsis thaliana) CESAs. The results showed that all primary CESAs can physically interact both in vitro and in planta with all secondary CESAs. Although CESAs are broadly capable of interacting in pairwise combinations, they are not all able to form functional complexes in planta. Analysis of transgenic lines showed that CESA7 can partially rescue defects in the primary cell wall biosynthesis in a weak cesa3 mutant. Green fluorescent protein-CESA protein fusions revealed that when CESA3 was replaced by CESA7 in the primary rosette, the velocity of the mixed complexes was slightly faster than the native primary complexes. CESA1 in turn can partly rescue defects in secondary cell wall biosynthesis in a cesa8ko mutant, resulting in an increase of cellulose content relative to cesa8ko. These results demonstrate that sufficient parallels exist between the primary and secondary complexes for cross-functionality and open the possibility that mixed complexes of primary and secondary CESAs may occur at particular times.

Do gene polymorphism in IL-1β, TNF-α and IL-6 influence therapeutic response in patients with drug refractory epilepsy?

PURPOSE

Pro-inflammatory cytokines may play an important pathophysiological role in patients with epilepsy. To understand the role of genes encoding pro-inflammatory cytokines in epilepsy, this study aimed to evaluate the polymorphisms of the promoter regions of IL-1β-511C>T (rs16944), TNF-α-308G>A (rs1800629) and IL-6-174G>C (rs1800795) genes and to look into the interaction between these genes in influencing seizure susceptibility, seizure frequency and response to therapy.

METHODS

The comparative frequency of polymorphism was determined in rs16944, rs1800629 and rs1800795 using PCR-RFLP in a group of 120 persons with epilepsy (PWE) and 110 ethnically matched healthy subjects of comparable age and sex in the North Indian population.

RESULTS

Alleles and genotypes of rs16944, rs1800629 and rs1800795 were not found to influence the odds ratio of having susceptibility to epilepsy. Also gene-gene interaction of possible nine combinations of these genes did not show any positive association with epilepsy. The genotype and allelic frequency of rs1800795 showed a significant association (p<0.05) in seizure frequency (number of seizures/6-months) and drug refractory epilepsy. However, the genotype and allelic frequency of rs16944 and rs1800629 were not found to have such effect.

CONCLUSION

This study demonstrates that the rs16944, rs1800629 and rs1800795 polymorphism does not act as a strong susceptibility factor for epilepsy in North Indian population. The genotypic association of rs1800795 with seizure frequency and drug-refractory epilepsy raises the issue that a specific set of polymorphic genes can influence seizures and therapeutic response in epilepsy.

MTHFR (677 and 1298) and IL-6-174 G/C genes in pathogenesis of Alzheimer's and vascular dementia and their epistatic interaction

Genetic risk factors play an important role in the pathogenesis of Alzheimer disease (AD) and vascular dementia (VaD). In this case-control study, we examined C677T and A1298C (rs1801133 and rs1801131) polymorphism in the methylenetetrahydrofolate reductase (MTHFR) genes and their correlation with plasma levels of homocysteine (Hcy) in AD and VaD cases and evaluated the gene-gene interaction (epistasis) with IL-6-174 G/C (rs1800795). CC genotype was associated with elevated levels of plasma homocysteine (p = 0.004) as compared with genotype AA of rs1801131. In AD, we observed a significant (p = 0.04) association with C alleles of rs1801131. Regression analysis revealed that the presence of both rs1801133 T and rs1800795 C alleles increased the odds of developing AD by 2.5 and VaD by 3.7-fold. While rs1800795 (CC or GC) genotypes alone increased the odds of developing VaD by 2.2-fold, the presence of CC genotype of rs1801131 nullified this effect. The findings support the hypothesis that multiple genes are involved to alter the odds of developing AD and VaD.

IL-6-174 G/C and ApoE gene polymorphisms in Alzheimer's and vascular dementia patients attending the cognitive disorder clinic of the All India Institute of Medical Sciences, New Delhi

BACKGROUND

Remarkable improvement in the life expectancy of the Indian population is expected to commensurate with the increase in number of dementia cases. Among various types of dementia, Alzheimer's disease (AD) and vascular dementia (VaD) are common and widely studied. We evaluated the role of apolipoprotein E (ApoE) and interleukin-6 (IL-6)-174 G/C gene polymorphism along with serum IL-6 levels in AD and VaD patients.

METHODS

The polymorphisms in ApoE and IL-6-174 G/C genes were assessed using RFLP. Serum IL-6 level was measured by ELISA.

RESULTS

The allele ε4 of the ApoE gene was found to be associated with AD and VaD patients (p < 0.05). No association of IL-6-174 G/C polymorphism was observed in AD patients, while the IL-6-174 C allele increased the odds of having VaD twofold. Regression analysis to assess possible interaction between ApoE and the IL-6-174 G/C genes revealed that presence of both the ε4 and C alleles increased the odds of having AD 13.75-fold and VaD 14.7-fold. Serum IL-6 levels did not correlate with either presence or severity of disease among AD or VaD patients.

CONCLUSION

The ApoE ε4 allele is an important genetic marker for AD and VaD. Presence of both ApoE ε4 and IL-6 C genes increases the OR of having AD and VaD markedly.