Burden of osteoarthritis in India and its states, 1990-2019: findings from the Global Burden of disease study 2019

OBJECTIVE

To describe the burden of osteoarthritis (OA) in India from 1990 to 2019.

DESIGN

Data from Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used. The burden of OA -knee OA, hip OA, hand OA, and other OA- was estimated for India and its states from 1990 to 2019 through a systematic analysis of prevalence, incidence, years lived with disability (YLD), and disability-adjusted life years (DALY) using methods reported in GBD 2019 study.

RESULT

Around 23.46 million individuals in India had OA in 1990; this increased to 62.35 million in 2019. The age-standardised prevalence of OA increased from 4,895 (95% uncertainty interval (UI):4,420-5,447) in 1990-5313 (95%UI:4,799-5,898) in 2019, per 100,000 persons. Similarly, DALYs due to OA increased from 0.79 million (95%UI:0.40-1.55) to 2.12 million (95%UI:1.07-4.23); while age-standardised DALYs increased from 164 (95%UI:83-325) to 180 (95%UI:91-361) per 100,000 persons from 1990 to 2019. OA was the 20^th most common cause of YLDs in India in 2019, accounting for 1.48% (95%UI:0.88-2.78) of all YLDs; increasing from 23rd most common cause in 1990 (1.25%(95%UI:0.74-2.34)). Knee OA was the most common form of OA, followed by hand OA. The prevalence, incidence, and DALYs for OA and knee OA were consistently higher in females than males.

CONCLUSION

The burden and impact of OA in India are substantial and is increasing. Adopting suitable control and preventive community measures to reduce modifiable risk factors (obesity, injuries, occupational stress) are needed to reduce the current and future burden of OA in India.

The Mafb cleft-associated variant H131Q is not required for palatogenesis in the mouse

BACKGROUND

Orofacial clefts (OFCs) are common birth defects with complex etiology. Genome wide association studies for OFC have identified SNPs in and near MAFB. MAFB is a transcription factor critical for structural development of digits, kidneys, skin, and brain. MAFB is also expressed in the craniofacial region. Previous sequencing of MAFB in a Filipino population revealed a novel missense variant significantly associated with an increased risk for OFC. This MAFB variant, leading to the amino acid change H131Q, was knocked into the mouse Mafb, resulting in the Mafb^H131Q allele. The Mafb^H131Q construct was engineered to allow for deletion of Mafb ("Mafb^del ").

RESULTS

Mafb^del/del animals died shortly after birth. Conversely, Mafb^H131Q/H131Q mice survived into adulthood at Mendelian ratios. Mafb^del/del and Mafb^H131Q/H131Q heads exhibited normal macroscopic and histological appearance at all embryonic time points evaluated. The periderm was intact based on expression of keratin 6, p63, and E-cadherin. Despite no effect on craniofacial morphogenesis, H131Q inhibited the Mafb-dependent promoter activation of Arhgap29 in palatal mesenchymal, but not ectodermal-derived epithelial cells in a luciferase assay.

CONCLUSIONS

Mafb is dispensable for murine palatogenesis in vivo, and the cleft-associated variant H131Q, despite its lack of morphogenic effect, altered the expression of Arhgap29 in a cell-dependent context.

ARHGAP29 Mutation Is Associated with Abnormal Oral Epithelial Adhesions

Nonsyndromic cleft lip and/or palate (NSCL/P) is a prevalent birth defect of complex etiology. Previous studies identified mutations in ARHGAP29 associated with an increased risk for NSCL/P. To investigate the effects of ARHGAP29 in vivo, we generated a novel murine allele by inserting a point mutation identified in a patient with NSCL/P. This single-nucleotide variation of ARHGAP29 translates to an early nonsense mutation (K326X), presumably resulting in loss-of-function (LoF). Embryos from Arhgap29^K326X/+ intercrosses were harvested at various time points. No homozygous Arhgap29^K326X animals were found in the 45 analyzed litters, assessed as early as embryonic day 8.5 (e8.5). Coronal sectioning of e13.5 and e14.5 heads revealed that 59% of Arhgap29^K326X/+ mice ( n = 37) exhibited improper epithelial contact between developing oral structures, while none were observed in wild types ( n = 10). In addition, Arhgap29^K326X/+ embryos exhibited a significantly higher percentage of maxillary epithelium in contact with mandibular epithelium. Immunofluorescent analyses of the periderm and oral adhesions revealed the presence of Arhgap29 in periderm cells. These cells were p63 negative, keratin 17 positive, and keratin 6 positive and present at sites of adhesion, although occasionally disorganized. Oral adhesions did not appear to impair palatogenesis, as all analyzed Arhgap29^K326X/+ embryos showed confluent palatal mesenchyme and epithelium at e18.5 ( n = 16), and no mice were found with a cleft at birth. Collectively, our data demonstrate that ARHGAP29 is required for embryonic survival and that heterozygosity for LoF variants of Arhgap29 increases the incidence and length of oral adhesions at a critical time point during orofacial development. In conclusion, we validate the LoF nature of the human K326X mutation in vivo and reveal a previously unknown effect of Arhgap29 in murine craniofacial development.

Small membrane proteins found by comparative genomics and ribosome binding site models

The correct annotation of genes encoding the smallest proteins is one of the biggest challenges of genome annotation, and perhaps more importantly, few annotated short open reading frames have been confirmed to correspond to synthesized proteins. We used sequence conservation and ribosome binding site models to predict genes encoding small proteins, defined as having 16-50 amino acids, in the intergenic regions of the Escherichia coli genome. We tested expression of these predicted as well as previously annotated genes by integrating the sequential peptide affinity tag directly upstream of the stop codon on the chromosome and assaying for synthesis using immunoblot assays. This approach confirmed that 20 previously annotated and 18 newly discovered proteins of 16-50 amino acids are synthesized. We summarize the properties of these small proteins; remarkably more than half of the proteins are predicted to be single-transmembrane proteins, nine of which we show co-fractionate with cell membranes.

DksA is required for growth phase-dependent regulation, growth rate-dependent control, and stringent control of fis expression in Escherichia coli

DksA is a critical transcription factor in Escherichia coli that binds to RNA polymerase and potentiates control of rRNA promoters and certain amino acid promoters. Given the kinetic similarities between rRNA promoters and the fis promoter (Pfis), we investigated the possibility that DksA might also control transcription from Pfis. We show that the absence of dksA extends transcription from Pfis well into the late logarithmic and stationary growth phases, demonstrating the importance of DksA for growth phase-dependent regulation of fis. We also show that transcription from Pfis increases with steady-state growth rate and that dksA is absolutely required for this regulation. In addition, both DksA and ppGpp are required for inhibition of Pfis promoter activity following amino acid starvation, and these factors act directly and synergistically to negatively control Pfis transcription in vitro. DksA decreases the half-life of the intrinsically short-lived fis promoter-RNA polymerase complex and increases its sensitivity to the concentration of CTP, the predominant initiating nucleotide triphosphate for this promoter. This work extends our understanding of the multiple factors controlling fis expression and demonstrates the generality of the DksA requirement for regulation of kinetically similar promoters.

Efficacy and safety of leflunomide alone and in combination with methotrexate in the treatment of refractory rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis patients who develop refractoriness are left with no alternatives other than leflunomide and costly biological response modifiers. Leflunomide, though effective, was associated with adverse events and has not been extensively studied in the Indian population.

AIMS

Determination of safety and efficacy of leflunomide alone and if not useful, in combination with methotrexate in patients refractory to conventional disease-modifying agents.

SETTING AND DESIGN

Open labeled clinical trial with leflunomide [100 mg, OD x 3 days followed by 20 mg, OD x 6 months], if no improvement at three months, combined with methotrexate [5-7.5 mg, OD x 3 months] at a tertiary care hospital.

MATERIALS AND METHODS

The primary endpoint in the improvement in EULAR criteria and secondary endpoints were patient and physician global evaluation, incidence of remission and biochemical and clinical adverse events.

STATISTICAL ANALYSIS

Chi square test or Fisher's exact test and parametric and non-parametric repeat measure ANOVA were used for analysis.

RESULTS

Among 84 patients who were included in the study, leflunomide showed improvement and remission in 52 [62%] and 6 [7%] in six months, by intention to treat analysis. Adverse events were observed in 15, discontinuation in 5 and 24 dropped out. With combination in 11 patients, there was improvement and remission in nine [91%] and one [9%] after three months. Adverse events were observed in six and one discontinued.

CONCLUSIONS

If regular monitoring of hepatic function and hematological parameters are performed, leflunomide is an effective and safe drug in the Indian population in resistant rheumatoid arthritis patients, especially if used alone.

DksA potentiates direct activation of amino acid promoters by ppGpp

Amino acid starvation in Escherichia coli results in a spectrum of changes in gene expression, including inhibition of rRNA and tRNA promoters and activation of certain promoters for amino acid biosynthesis and transport. The unusual nucleotide ppGpp plays an important role in both negative and positive regulation. Previously, we and others suggested that positive effects of ppGpp might be indirect, resulting from the inhibition of rRNA transcription and, thus, liberation of RNA polymerase for binding to other promoters. Recently, we showed that DksA binds to RNA polymerase and greatly enhances direct effects of ppGpp on the negative control of rRNA promoters. This conclusion prompted us to reevaluate whether ppGpp might also have a direct role in positive control. We show here that ppGpp greatly increases the rate of transcription initiation from amino acid promoters in a purified system but only when DksA is present. Activation occurs by stimulation of the rate of an isomerization step on the pathway to open complex formation. Consistent with the model that ppGpp/DksA stimulates amino acid promoters both directly and indirectly in vivo, cells lacking dksA fail to activate transcription from the hisG promoter after amino acid starvation. Our results illustrate how transcription factors can positively regulate transcription initiation without binding DNA, demonstrate that dksA directly affects promoters in addition to those for rRNA, and suggest that some of the pleiotropic effects previously associated with dksA might be ascribable to direct effects of dksA on promoters involved in a wide variety of cellular functions.

rRNA transcription in Escherichia coli

Ribosomal RNA transcription is the rate-limiting step in ribosome synthesis in bacteria and has been investigated intensely for over half a century. Multiple mechanisms ensure that rRNA synthesis rates are appropriate for the cell's particular growth condition. Recently, important advances have been made in our understanding of rRNA transcription initiation in Escherichia coli. These include (a) a model at the atomic level of the network of protein-DNA and protein-protein interactions that recruit RNA polymerase to rRNA promoters, accounting for their extraordinary strength; (b) discovery of the nonredundant roles of two small molecule effectors, ppGpp and the initiating NTP, in regulation of rRNA transcription initiation; and (c) identification of a new component of the transcription machinery, DksA, that is absolutely required for regulation of rRNA promoter activity. Together, these advances provide clues important for our molecular understanding not only of rRNA transcription, but also of transcription in general.

DksA

Ribosomal RNA (rRNA) transcription is regulated primarily at the level of initiation from rRNA promoters. The unusual kinetic properties of these promoters result in their specific regulation by two small molecule signals, ppGpp and the initiating NTP, that bind to RNA polymerase (RNAP) at all promoters. We show here that DksA, a protein previously unsuspected as a transcription factor, is absolutely required for rRNA regulation. In deltadksA mutants, rRNA promoters are unresponsive to changes in amino acid availability, growth rate, or growth phase. In vitro, DksA binds to RNAP, reduces open complex lifetime, inhibits rRNA promoter activity, and amplifies effects of ppGpp and the initiating NTP on rRNA transcription, explaining the dksA requirement in vivo. These results expand our molecular understanding of rRNA transcription regulation, may explain previously described pleiotropic effects of dksA, and illustrate how transcription factors that do not bind DNA can nevertheless potentiate RNAP for regulation.

An intersubunit contact stimulating transcription initiation by E coli RNA polymerase: interaction of the alpha C-terminal domain and sigma region 4

The C-terminal domain of the Escherichia coli RNA polymerase (RNAP) alpha subunit (alphaCTD) stimulates transcription initiation by interacting with upstream (UP) element DNA and a variety of transcription activators. Here we identify specific substitutions in region 4.2 of sigma 70 (sigma(70)) and in alphaCTD that decrease transcription initiation from promoters containing some, but not all, UP elements. This decrease in transcription derives from a decrease in the initial equilibrium constant for RNAP binding (K(B)). The open complexes formed by the mutant and wild-type RNAPs differ in DNAse I sensitivity at the junction of the alphaCTD and sigma DNA binding sites, correlating with the differences in transcription. A model of the DNA-alphaCTD-sigma region 4.2 ternary complex, constructed from the previously determined X-ray structures of the Thermus aquaticus sigma region 4.2-DNA complex and the E. coli alphaCTD-DNA complex, indicates that the residues identified by mutation in sigma region 4.2 and in alphaCTD are in very close proximity. Our results strongly suggest that alphaCTD, when bound to an UP element proximal subsite, contacts the RNAP sigma(70) subunit, increasing transcription. Previous data from the literature suggest that this same sigma-alphaCTD interaction also plays a role in transcription factor-mediated activation.

Simultaneous detection of different glycosidase activities by 19F NMR spectroscopy

A fast method for the simultaneous detection of different glycosidolytic activities in commercially available enzyme preparations and crude culture filtrates was found in using, as substrate, a mixture of different glycosyl fluorides and 19F NMR spectroscopy as a screening technique. Accompanying studies regarding the hydrolytic stability of these fluorides in various buffer systems, as well as conditions of their long-term storage, were carried out. A simple procedure for the preparation of beta-D-mannopyranosyl fluoride in gram quantities is given.

Synthesis of deoxyfluoro sugars from carbohydrate precursors

Results obtained over the past decade concerning the introduction of the fluorine atom into carbohydrate molecules, either by nucleophilic substitution or electrophilic addition reactions, are summarised. The first section mainly deals with the triflate/fluoride tandem sequence and the DAST-reaction. In the discussion, emphasis is given to the dependency of the reaction course on the stereochemical and protecting group features. Possible reaction pathways are direct substitution (with inversion or retention of configuration), rearrangement (combined with substitution and inversion of configuration at both of the centres involved) and elimination. Based on the assumption of cyclic transition states or transient intermediates (formed through participation of neighbouring groups), far-reaching mechanistic generalisations were made. On this basis, isolated examples from the literature, which are not in accordance with these generalisations, are specifically brought to attention. Results from the recently introduced reaction of safe and easy to handle N-F fluorinating agents with glycals are also reported. This approach allows the simple and stereoselective access to a series of 2-deoxy-2-fluoro aldopyranoses, as well as the synthesis of various C-1-substituted derivatives by an easy one-pot reaction. However, the same method applied to furanoid glycals is rather poor with respect to stereoselectivity. Finally, considerations on the importance of fluorine-specific reactions of the S(N)-type in related fields of organic synthesis are made.

Osteoporosis in hemiplegia

Localized osteoporosis in 25 long-term stroke patients was evaluated by means of measuring the combined cortical thickness in the humerus, radius and third metacarpal bones of both involved and noninvolved upper extremities. The combined cortical thickness was found to be consistently smaller on the involved side. Since the factors of weight bearing and calcium homeostasis were eliminated or controlled in this study, the authors were able to focus on the role of muscle pull as manifested by voluntary muscle function and spasticity in relation to the degree of cortical thinning. A smaller degree of cortical thinning was associated with better voluntary muscle function, but the relationship of spasticity to preservation of cortical thickness was not clear cut. The applicability of these techniques to the study of factors affecting localized osteoporosis is discussed.