Early Degeneration Research Articles

Prevalence and Predictive Factors of Early Degeneration of Bioprosthetic Mitral Valves: A Single-Center Cohort Study

Background. Bioprosthetic mitral valves (MV) have limited durability. Dysfunction and degeneration of these valves can lead to reoperation and progressive heart failure. We investigated the frequency and predictors of MV bioprosthesis early degeneration within three years following MV replacement surgery. Methods. In this retrospective cohort study, we retrieved the data of consecutive patients who underwent bioprosthetic MV replacement through midsternotomy at Tehran Heart Center between 2013 and 2019. Based on the reviewed parameters of the bioprosthetic MV in the follow-up echocardiography, the patients were divided into two groups to compare the variables respecting early degeneration. Finally, the predictors of early degeneration were recognized using the Cox regression hazards model. Results. We reviewed and analyzed data of 177 patients from our hospital database. The mean age of the patients was 63.9 ± 11.7 years and 100 (56.5%) were women. 39 (22.0%) patients had experienced early degeneration and two (1.1% of the total) had died during the follow-up period. Patients in the degeneration group tended to have a history of stroke and renal failure, although not statistically significant. The sole independent predictor of early degeneration of bioprosthetic MV was a high MV mean gradient in the first postoperative echocardiography study (HR = 11.01, 95% CI: 4.80–25.24; P < 0.001 ). Conclusion. About 22.0% of our patients had echocardiographic criteria for early degeneration, and according to our results, increased MV gradients (without considering the reason) in the first postoperative echocardiography were the sole independent predictor for it. Careful valve selection can be essential in reducing early degeneration.

Visible and Near-Infrared Spectroscopy Enables Differentiation of Normal and Early Osteoarthritic Human Knee Joint Articular Cartilage

Osteoarthritis degenerates cartilage and impairs joint function. Early intervention opportunities are missed as current diagnostic methods are insensitive to early tissue degeneration. We investigated the capability of visible light-near-infrared spectroscopy (Vis-NIRS) to differentiate normal human cartilage from early osteoarthritic one. Vis-NIRS spectra, biomechanical properties and the state of osteoarthritis (OARSI grade) were quantified from osteochondral samples harvested from different anatomical sites of human cadaver knees. Two support vector machines (SVM) classifiers were developed based on the Vis-NIRS spectra and OARSI scores. The first classifier was designed to distinguish normal (OARSI: 0–1) from general osteoarthritic cartilage (OARSI: 2–5) to check the general suitability of the approach yielding an average accuracy of 75% (AUC = 0.77). Then, the second classifier was designed to distinguish normal from early osteoarthritic cartilage (OARSI: 2–3) yielding an average accuracy of 71% (AUC = 0.73). Important wavelength regions for differentiating normal from early osteoarthritic cartilage were related to collagen organization (wavelength region: 400–600 nm), collagen content (1000–1300 nm) and proteoglycan content (1600–1850 nm). The findings suggest that Vis-NIRS allows objective differentiation of normal and early osteoarthritic tissue, e.g., during arthroscopic repair surgeries.

Macular and Plasma Xanthophylls Are Higher in Age-related Macular Degeneration than in Normal Aging: Alabama Study on Early Age-related Macular Degeneration 2 Baseline.

Quantification of retinal xanthophyll carotenoids in eyes with and without age-related macular degeneration (AMD) via macular pigment optical volume (MPOV), a metric for xanthophyll abundance from dual wavelength autofluorescence, plus correlations to plasma levels, could clarify the role of lutein (L) and zeaxanthin (Z) in health, AMD progression, and supplementation strategies. Cross-sectional observational study (NCT04112667). Adults ≥ 60 years from a comprehensive ophthalmology clinic, with healthy maculas or maculas meeting fundus criteria for early or intermediate AMD. Macular health and supplement use was assessed by the Age-related Eye Disease Study (AREDS) 9-step scale and self-report, respectively. Macular pigment optical volume was measured from dual wavelength autofluorescence emissions (Spectralis, Heidelberg Engineering). Non-fasting blood draws were assayed for L and Z using high-performance liquid chromatography. Associations among plasma xanthophylls and MPOV were assessed adjusting for age. Age-related macular degeneration presence and severity, MPOV in fovea-centered regions of radius 2.0° and 9.0°; plasma L and Z (μM/ml). Of 809 eyes from 434 persons (89% aged 60-79, 61% female), 53.3% eyes were normal, 28.2% early AMD, and 18.5% intermediate AMD. Macular pigment optical volume 2° and 9° were similar in phakic and pseudophakic eyes, which were combined for analysis. Macular pigment optical volume 2° and 9° and plasma L and Z were higher in early AMD than normal and higher still in intermediate AMD (P<0.0001). For all participants, higher plasma L was correlated with higher MPOV 2° (Spearman correlation coefficient [Rs]=0.49; P < 0.0001). These correlations were significant (P<0.0001) but lower in normal (Rs=0.37) than early and intermediate AMD (Rs=0.52 and 0.51, respectively). Results were similar for MPOV 9°. Plasma Z, MPOV 2°, and MPOV 9° followed this same pattern of associations. Associations were not affected by supplement use or smoking status. A moderate positive correlation of MPOV with plasma L and Z comports with regulated xanthophyll bioavailability and a hypothesized role for xanthophyll transfer in soft drusen biology. An assumption that xanthophylls are low in AMD retina underlies supplementation strategies to reduce progression risk, which our data do not support. Whether higher xanthophyll levels in AMD are due to supplement use cannot be determined in this study.

Deformation‐based morphometry analysis shows early degeneration in Nucleus basalis of Meynert in Alzheimer’s disease

AbstractBackgroundNucleus basalis of Meynert (NbM) is the main source of cholinergic projection to the cerebral cortex, including entorhinal cortex (EC). Both cholinergic cells of NbM and their receptive targets in EC show degeneration during early stages of Alzheimer’s disease (AD). While precise delineation of NbM region on T1w scans is difficult due to limited spatial resolution and contrast, we sought to quantify the degeneration of NbM along the disease trajectory and confirm recent studies suggesting that NbM degeneration happens before degeneration in the EC using deformation‐based morphometry (DBM).MethodData included MRI scans of 1473 subjects from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. Resolution was increased to 0.5 mm isotropic voxel‐size before non‐linear registration to an ADNI‐based unbiased symmetric template. The resulting deformation fields were used to compute the Jacobian determinant map for each subject as a proxy for local volume. NbM and EC masks were mapped to our high‐resolution template and mean determinant values inside these masks were calculated for groups with different baseline diagnosis, and sex‐ and age‐corrected z‐scores were calculated. Two‐sample t‐tests were then used to compare the scores between different groups.ResultFigure 1 shows the mean DBM score of both NbM and EC regions for Normal Controls (CN), subjects with early‐ and late‐stage mild cognitive impairment (EMCI and LMCI) and subjects with probable AD dementia. Results corrected for multiple comparisons showed a significant difference between CN and both EMCI and LMCI for left and right NbM. A significant difference was also observed between EMCI and LMCI in left NbM (p‐value = 0.0024). Z‐scored EC volumes did not show a significant difference between CN and EMCI groups; However, results from EMCI and LMCI differ significantly in both hemispheres. We also observed the expected differences between each group with AD in both NbM and EC (P&lt;0.001).ConclusionOur results show that while macroscopic changes in EC emerge as MCI subjects advance toward the later stages, NbM degeneration starts sooner, as early as preliminary stages of MCI. This points to MRI‐based measurements of NbM as potential biomarkers for early detection of AD and as a marker of disease burden.

Deformation‐based morphometry analysis shows early degeneration in Nucleus basalis of Meynert in Subjective Cognitive Decline

AbstractBackgroundPeople with subjective cognitive decline (SCD+) are thought to be at greater risk of Alzheimer’s disease (AD). The Nucleus basalis of Meynert (NbM) has been shown to change early in AD (Fernández‐Cabello et al., 2020), and it is the main source of cholinergic projection to entorhinal cortex (EC) (Mesulam et al., 2013). We thus investigated if there was evidence of degeneration in the NbM, or EC in SCD+ participants compared to those without (SCD‐), and if there was a relationship between changes in these regions and SCD status using deformation‐based morphometry (DBM).MethodData included baseline visit MRI scans of 232 cognitively healthy older adults (148 SCD‐; 84 SCD+) from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset (using only ADNI2). SCD status was extracted based on the cognitive change index (CCI) of the subjects reported in ADNIMERGE data (CCI ≥16). MRI resolution was increased to 0.5 mm isotropic voxel‐size before non‐linear registration to an ADNI‐based unbiased symmetric template. The resulting deformation fields were used to compute the Jacobian determinant map for each subject as a proxy for local volume. NbM, and EC masks were mapped to our high‐resolution template and mean determinant values inside these masks were estimated, and sex‐ and age‐corrected z‐scores were calculated. Two‐sample t‐tests were then used to compare the SCD+:SCD‐ differences.ResultFigure 1 shows the mean z‐score values for NbM and EC regions for both SCD+ and SCD‐ groups. Results for left NbM showed a significant difference between two groups (p = .007), but not for the right NbM (p = .12). However, z‐scored EC volumes did not show any statistically significant difference between groups for either left (p = .58) or right region (p = .41).ConclusionOur results suggest that in SCD+ subjects, while the EC is still intact, neurodegeneration in the NbM appears to have already begun. Quantifying degeneration in the NbM may allow for early diagnosis of AD. Further research is needed to evaluate if such differences can be computed on an individual subject basis for use as a biomarker.

Early disc degeneration in radiotherapy-treated childhood brain tumor survivors

BackgroundChildhood brain tumor (BT) survivors have an increased risk of treatment-related late effects, which can reduce health-related quality of life and increase morbidity. This study aimed to investigate lumbar disc degeneration in magnetic resonance imaging (MRI) in adult survivors of radiotherapy-treated childhood BT compared to age and sex-matched population controls.MethodsIn this cross-sectional comparative study, 127 survivors were identified from hospital registries. After a mean follow-up of 20.7 years (range 5–33.1), 67 survivors (mean age 28.4, range 16.2–43.5) were investigated with MRI and compared to 75 sex-matched population-based controls. Evaluated MRI phenotypes included Pfirrmann grading, , intervertebral disc protrusions, extrusions, and high-intensity-zone-lesions (HIZ). Groups were also compared for known risk factors of lumbar intervertebral disc (IVD) degeneration.ResultsChildhood BT survivors had higher Pfirrmann grades than controls at all lumbar levels (all p < 0.001). Lumbar disc protrusions at L4-5 (p = 0.02) and extrusions at L3-4 (p = 0.04), L4-5 (p = 0.004), and L5-S1 (p = 0.01) were significantly more common in the BT group compared to the control. The survivor cohort also had significantly more HIZ-lesons than the controls (n=13 and n=1, p=0.003). Age at diagnosis was associated with lower degree of IVD degeneration (p < 0.01). Blood pressure correlated with IVD degeneration (P < 0.05).ConclusionsSigns of early disc degeneration related to tumor treatment can be seen in the IVDs of survivors. Disc degeneration was more severe in children treated in adolescence.

A New Preclinical Model of Retinitis Pigmentosa Due to Pde6g Deficiency

Retinitis pigmentosa (RP) is the most common cause of inherited blindness, with onset occurring as early as 4 years of age in certain rare but severe forms caused by mutations in the gamma subunit of phosphodiesterase 6 (PDE6). Studies in humans and mice have shown that RP pathology begins with progressive photoreceptor death, which then drives changes in downstream neurons, neighboring retinal pigment epithelium (RPE), and vasculature. Here, we present the first detailed analysis of RP disease progression in Pde6g-deficient mice. Experimental study of an RP mouse model. We studied Pde6g-/- and Pde6g+/- mice at the age of 7, 16, 30, 44, and 56 days with n=2 to 5 per group and time point. Photoreceptor degeneration and retinal remodeling were analyzed in retinal sections by immunofluorescence. Retinal blood vessel degradation was analyzed in flat-mounted retinas immunolabeled for isolectin GS-IB4. Protein expression was measured by immunoblot. Acellular capillaries were assessed in trypsin-digested and hematoxylin-eosin-stained retinas at postnatal day (P) 44. Retinal pigment epithelium cells were delineated in flat-mounted RPE-choroid-sclera by immunolabeling for the cell-adhesion protein β-catenin. Immunofluorescence and morphometry (quantitative analysis of outer nuclear layer, dendrite area, vessel area, acellular vessels, RPE cell size, number of nuclei per RPE cell, RPE cell eccentricity, and RPE cell solidity). This novel RP model exhibits early onset and rapid rod degeneration, with the vast majority gone by P16. This pathology leads to retinal remodeling, including changes of inner retinal neurons, early activation of glia cells, degradation of retinal vasculature, and structural abnormalities of the RPE. The pathology in our Pde6g-/- mouse model precisely mirrors human RP progression. The results demonstrate the significant role of the gamma subunit in maintaining phosphodiesterase activity and provide new insights into the disease progression due to Pde6g deficiency. Proprietary or commercial disclosure may be found after the references.

A nonsense mutation in C8orf37 linked with retinitis pigmentosa, early macular degeneration, cataract, and myopia in an arRP family from North India

ObjectiveThis study aimed at identifying the underlying genetic defect in a consanguineous autosomal recessive retinitis pigmentosa (arRP) (RP-1175) family having RP with early macular degeneration, cataract, and myopia.MethodsWhole-exome sequencing (WES) was performed on the DNA of the proband, and variants observed were validated in the rest of the affected and unaffected family members by Sanger sequencing. Different bioinformatics tools were applied to access the pathogenicity of the observed variant.ResultsA nonsense mutation i.e., c.555G > A (p.Trp185Ter) in C8orf37 in homozygous form, has been identified that segregated with the disease in the affected members. c.555G > A was absent in unaffected family members and in 107 ethnically matched controls, therefore ruling out its possibility of being a polymorphism.ConclusionsPresent study identifies a nonsense mutation (c.555G > A) at codon 185 in C8orf37 linked with arRP, early macular degeneration, posterior subcapsular cataract, and myopia. The identical mutation has previously been reported in a Pakistani family with isolated RP and in a Chinese family with RP and macular degeneration. This variable expressivity of the identified mutation c.555G > A in C8orf37 in the analyzed Indian family may be attributed to the presence of the modifier alleles. Also, Trp185 might be a mutation hotspot in Asian arRP patients and in the future, p.Trp185Ter in C8orf37 may be tested during initial screening in arRP cases especially belonging to a similar population.

Ultrasonographic echo intensity in the medial femoral cartilage is enhanced prior to cartilage thinning in women with early mild knee osteoarthritis.

We aimed to determine whether altered cartilage echo intensity is associated with knee osteoarthritis (OA) severity and whether the alteration occurs before thinning of the femoral cartilage in knee OA. The medial femoral cartilage thickness and echo intensity of 118 women aged ≥ 50years were assessed using an ultrasound imaging device. Based on the Kellgren-Lawrence (KL) grade and knee symptoms, participants were classified into five groups: control (asymptomatic grades 0-1), early OA (symptomatic grade 1), grade 2, grade 3, and grade 4. Analysis of covariance, with adjusted age and height, and the Sidak post hoc test were used to assess the differences in cartilage thickness and echo intensity in knees with varying OA severity. The echo intensity on longitudinal images, equivalent to the tibiofemoral weight-bearing surface, was significantly higher in the grade 2 group than that in the control group (p = 0.049). However, no significant difference was noted in cartilage thickness (n.s.). In the grades 3 and 4 groups, cartilage thickness became thinner as OA progressed (p < 0.001 and p < 0.001, respectively). However, the cartilage echo intensity was not significantly enhanced compared with that of the grade 2 group (n.s.). There were no significant differences in the cartilage thickness and echo intensity between the early OA and control groups on the longitudinal images (n.s.). The echo intensity of the medial femoral cartilage was high in patients with KL grade 2, without decreased thickness. Our findings suggested that higher echo intensity is a feature of early cartilage degeneration in mild knee OA. Further studies are needed to establish this feature as a useful screening parameter of early cartilage degeneration in knee OA. Level III.

Short exposure to photo-oxidative damage triggers molecular signals indicative of early retinal degeneration.

Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, currently affecting over 350 billion people globally. For the most prevalent late-stage form of this disease, atrophic AMD, there are no available prevention strategies or treatments, in part due to inherent difficulties in early-stage diagnosis. Photo-oxidative damage is a well-established model for studying inflammatory and cell death features that occur in late-stage atrophic AMD, however to date has not been investigated as a potential model for studying early features of disease onset. Therefore, in this study we aimed to determine if short exposure to photo-oxidative damage could be used to induce early retinal molecular changes and advance this as a potential model for studying early-stage AMD. C57BL/6J mice were exposed to 1, 3, 6, 12, or 24h photo-oxidative damage (PD) using 100k lux bright white light. Mice were compared to dim-reared (DR) healthy controls as well as mice which had undergone long periods of photo-oxidative damage (3d and 5d-PD) as known timepoints for inducing late-stage retinal degeneration pathologies. Cell death and retinal inflammation were measured using immunohistochemistry and qRT-PCR. To identify retinal molecular changes, retinal lysates were sent for RNA sequencing, following which bioinformatics analyses including differential expression and pathway analyses were performed. Finally, to investigate modulations in gene regulation as a consequence of degeneration, microRNA (miRNA) expression patterns were quantified using qRT-PCR and visualized using in situ hybridization. Short exposure to photo-oxidative damage (1-24h-PD) induced early molecular changes in the retina, with progressive downregulation of homeostatic pathways including metabolism, transport and phototransduction observed across this time-course. Inflammatory pathway upregulation was observed from 3h-PD, preceding observable levels of microglia/macrophage activation which was noted from 6h-PD, as well as significant photoreceptor row loss from 24h-PD. Further rapid and dynamic movement of inflammatory regulator miRNA, miR-124-3p and miR-155-5p, was visualized in the retina in response to degeneration. These results support the use of short exposure to photo-oxidative damage as a model of early AMD and suggest that early inflammatory changes in the retina may contribute to pathological features of AMD progression including immune cell activation and photoreceptor cell death. We suggest that early intervention of these inflammatory pathways by targeting miRNA such as miR-124-3p and miR-155-5p or their target genes may prevent progression into late-stage pathology.

Higher plasma β-synuclein indicates early synaptic degeneration in Alzheimer's disease.

β-Synuclein is an emerging synaptic blood biomarker for Alzheimer's disease (AD) but differences in β-synuclein levels in preclinical AD and its association with amyloid and tau pathology have not yet been studied. We measured plasma β-synuclein levels in cognitively unimpaired individuals with positive Aβ-PET (i.e., preclinical AD, N=48) or negative Aβ-PET (N=61), Aβ-positive patients with mild cognitive impairment (MCI, N=36), and Aβ-positive AD dementia (N=85). Amyloid (A) and tau (T) pathology were assessed by [18 F]flutemetamol and [18 F]RO948 PET. Plasma β-synuclein levels were higher in preclinical AD and even higher in MCI and AD dementia. Stratification according to amyloid/tau pathology revealed higher β-synuclein in A+ T- and A+ T+ subjects compared with A- T- . Plasma β-synuclein levels were related to tau and Aβ pathology and associated with temporal cortical thinning and cognitive impairment. Our data indicate that plasma β-synuclein might track synaptic dysfunction, even during the preclinical stages of AD. Plasma β-synuclein is already higher in preclinical AD. Plasma β-synuclein is higher in MCI and AD dementia than in preclinical AD. Aβ- and tau-PET SUVRs are associated with plasma β-synuclein levels. Plasma β-synuclein is already higher in tau-PET negative subjects. Plasma β-synuclein is related to temporal cortical atrophy and cognitive impairment.

A Single-Centre, Retrospective, Observational Study to Assess Safety and Functional Outcomes of Arthroscopic Meniscal Repair Using Surestitch All Inside Implant.

Introduction The meniscus plays a vital role in maintaining knee stability. It acts as a shock absorber and knee filler. The incidence of meniscal tears is estimated to be 60 per 100,000 people. Due to lack of awareness among patients, only 10% of the meniscus tears were treated through partial or total meniscectomy. Recently, the concept of meniscus preservation surgery has emerged to preserve early degeneration of the knee joint. In the current retrospective study, safety and functional outcomes of arthroscopic meniscal repair surgery using SurestitchAll inside implants (Sironix Arthroscopy Solutions, Healthium Medtech Limited, Bengalaru, India) were assessed. Methods Fifty-two patients who underwent arthroscopic meniscal repair surgery between January 2019 to July 2022 at Epic Hospital in Gujarat, India, were enrolled in the study. Retrospective data including demographics, injury details, surgery details, and post-surgery complications were collected from the medical records of the patients. Then, the patients were followed up telephonically to document safety and functional outcomes using patient-reported instruments such as International Knee Documentation Committee (IKDC) score, Single Assessment Numeric Evaluation (SANE) score, Tegner activity level, and Lysholm knee score. Results The recruited patients had the mean age, height, and weight of 37.56 ± 12.52 years, 167.61 ± 7.28 cm, and 75.87 ± 10.7 kgs, respectively. Seventy-one percent of patients were male and 29% were female. Majority of the patients had the routine of doing mild exercise. During pre-surgery representations, medial meniscal tear was observed in majority of patients. The mean length of the tear was 1.32 ± 0.84 cm. In addition, patients were also diagnosed with anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) tears, and osteochondral defects. Surgeries for meniscal repair were performed using Surestitch All inside implant. In patient-reported outcomes, the mean IKDC, SANE, and Lysholm scores were 81.72 ± 14.23, 94.02 ± 13.79, and 93.32 ± 14.63, respectively. When the mean Tegner scores of pre-injury and post-surgery periods were compared, this resulted in no significant difference (p>0.05) in the activity levels of the patients. Conclusion Based on our findings, arthroscopic meniscal repair with Surestitch All inside meniscal repair implant provides satisfactory and favorable functional outcomes with no remarkable adverse events.

CHANGES TO LEVELS OF CHONDROCYTE-ASSOCIATED ADAMTS-4 IN EARLY HUMAN OSTEOARTHRITIS

Early changes within articular cartilage during human idiopathic osteoarthritis are poorly understood. However alterations to chondrocyte morphology occur with the development of fine cytoplasmic processes and cell clusters, potentially playing a role in cartilage degeneration. The aggrecanase ADAMTS-4 (A disintegrin and metalloproteinase with thrombospondin motifs-4) has been implicated as an important factor in cartilage degradation, so we investigated the relationship between chondrocyte morphology and levels of ADAMTS-4 in both non-degenerate and mildly osteoarthritic human cartilage.Human femoral heads were obtained following consent from patients undergoing hip arthroplasty following femoral neck fracture. Cartilage explants of normal (grade 0; G0) and mildly osteoarthritic (grade 1; G1) cartilage were labelled with the cytoplasmic dye CMFDA (5-chloromethylfluorescein-diacetate). Explants were cryosectioned (30μm sections), and labelled for ADAMTS-4 by fluorescence immunohistochemistry. Sections were imaged with confocal microscopy, allowing the semi-quantitative analysis of ADAMTS-4 and 3D visualisation of in situ cell morphology.With cartilage degeneration from G0 to G1, there was a decrease in the proportion of chondrocytes with normal rounded morphology (P&lt;0.001) but an increase in the proportion of cells with processes (P&lt;0.01) and those in clusters (P&lt;0.001;[4(1653)]; femoral heads:cells). Although average levels of ADAMTS-4 for all cells was the same between G0 and G1 (P&gt;0.05), a change was evident in the distribution curves for cell-specific ADAMTS-4 labelling. Cell-by-cell analysis showed that ADAMTS-4 levels were higher in chondrocytes with cytoplasmic processes compared to normal cells (P=0.044) however cells in clusters had lower levels than normal cells (P=0.003;[3(436)]). Preliminary data suggested that ADAMTS-4 levels increased with larger chondrocyte clusters.These results suggest complex heterogeneous changes to levels of cell-associated ADAMTS-4 with early cartilage degeneration – increasing in cells with processes and initially decreasing in clusters. Increased levels of ADAMTS-4 are likely to produce focal areas of matrix weakness potentially leading to early cartilage degeneration.

Phenotypic diversity observed in a Chinese patient cohort with biallelic variants in Bardet-Biedl syndrome genes.

Bardet-Biedl syndrome (BBS) is a rare multisystem ciliopathy. The aim of this study was to describe the clinical and genetic features of a cohort of Chinese patients carrying biallelic BBS gene variants. We recruited 34 patients from 31 unrelated pedigrees who carried biallelic pathogenic variants in BBS genes. All patients underwent ophthalmic and systematic evaluations, as well as comprehensive molecular genetic analyses. Ultimately, 14 patients were followed up over time. We identified 47 diseasing-causing variants in 10 BBS genes; 33 were novel. Diagnosis of BBS and non-syndromic retinitis pigmentosa (RP) were established in 28 patients from 27 pedigrees and 6 patients, respectively. The two most prevalent genes in patients with BBS were BBS2 and BBS4, accounting for 51.8% of the probands. The patients exhibited clinical heterogeneity, from patients with all six primary clinical components to patients suffering from non-syndromic RP. The common components were retinal dystrophy, polydactyly, and obesity, with frequencies of 78.6% to 100%, while renal anomaly frequencies were only 7.1%. Patients exhibited early and severe visual defects and retinal degeneration. Patients with biallelic missense variants in BBS2 suffered fewer clinical symptoms and mild visual impairment. Patients with BBS10 variants tended to have cone dystrophy. Our study defined the mutated gene profiles and established the configuration of the variation frequencies for each BBS gene in Chinese patients. Overall, our patients showed early and severe visual defects and retinal degeneration. Genetic analysis is therefore crucial for diagnosis, genetic counseling, and future gene therapy in these patients.

Disruptive lysosomal-metabolic signaling and neurodevelopmental deficits that precede Purkinje cell loss in a mouse model of Niemann-Pick Type-C disease

Purkinje cell (PC) loss occurs at an early age in patients and animal models of Niemann-Pick Type C (NPC), a lysosomal storage disease caused by mutations in the Npc1 or Npc2 genes. Although degeneration of PCs occurs early in NPC, little is known about how NPC1 deficiency affects the postnatal development of PCs. Using the Npc1nmf164 mouse model, we found that NPC1 deficiency significantly affected the postnatal development of PC dendrites and synapses. The developing dendrites of Npc1nmf164 PCs were significantly deficient in mitochondria and lysosomes. Furthermore, anabolic (mTORC1) and catabolic (TFEB) signaling pathways were not only perturbed but simultaneously activated in NPC1-deficient PCs, suggesting a loss of metabolic balance. We also found that mice with conditional heterozygous deletion of the Phosphatase and Tensin Homolog Deleted on Chromosome 10 gene (Pten-cHet), an inhibitor of mTORC1, showed similar early dendritic alterations in PCs to those found in Npc1-deficient mice. However, in contrast to Npc1nmf164 mice, Pten-cHet mice exhibited the overactivation of the mTORC1 pathway but with a strong inhibition of TFEB signaling, along with no dendritic mitochondrial reductions by the end of their postnatal development. Our data suggest that disruption of the lysosomal-metabolic signaling in PCs causes dendritic and synaptic developmental deficits that precede and promote their early degeneration in NPC.

The Corticosteroid Meniscectomy Trial of Extended-Release Triamcinolone Injection After Arthroscopic Partial Meniscectomy: Protocol for a Double-Blind Randomized Controlled Trial.

Meniscal tear in older adults often accompanies knee osteoarthritis and is commonly treated with arthroscopic partial meniscectomy (APM) when patients have persistent pain after a trial of physical therapy. Cross-sectional evidence suggests that synovitis is associated with baseline pain in this patient population, but little is known about the relationship between synovitis and postoperative recovery or progression of knee osteoarthritis. Intra-articular extended-release triamcinolone may reduce inflammation and thereby improve outcomes and slow disease progression. This article presents the rationale behind the Corticosteroid Meniscectomy Trial (CoMeT) and describes its study design and implementation strategies. Randomized controlled trial. CoMeT is a 2-arm, 3-center, randomized placebo-controlled trial designed to establish the clinical efficacy of extended-release triamcinolone administered via intra-articular injection immediately after APM. The primary outcome is change in Knee injury and Osteoarthritis Outcome Score Pain subscore at 3-month follow-up. Synovial biopsy, joint fluid aspirate, and urine and blood sample analyses will examine the associations between various objective measures of baseline inflammation and pre- and postoperative outcome measures and clinical responses to triamcinolone intervention. Quantitative 3-T magnetic resonance imaging will evaluate cartilage and meniscal composition and 3-dimensional bone shape to detect early joint degeneration. We discuss methodologic innovations and challenges. To our knowledge, this is the first randomized double-blind clinical trial that will analyze the effect of extended-release triamcinolone acetonide on pain, magnetic resonance imaging measures of structural change and effusion/synovitis, soluble biomarkers, and synovial tissue transcriptomics after APM.

Cbfβ Is a Novel Modulator against Osteoarthritis by Maintaining Articular Cartilage Homeostasis through TGF-β Signaling

TGF-β signaling is a vital regulator for maintaining articular cartilage homeostasis. Runx transcription factors, downstream targets of TGF-β signaling, have been studied in the context of osteoarthritis (OA). Although Runx partner core binding factor β (Cbfβ) is known to play a pivotal role in chondrocyte and osteoblast differentiation, the role of Cbfβ in maintaining articular cartilage integrity remains obscure. This study investigated Cbfβ as a novel anabolic modulator of TGF-β signaling and determined its role in articular cartilage homeostasis. Cbfβ significantly decreased in aged mouse articular cartilage and human OA cartilage. Articular chondrocyte-specific Cbfb-deficient mice (Cbfb△ac/△ac) exhibited early cartilage degeneration at 20 weeks of age and developed OA at 12 months. Cbfb△ac/△ac mice showed enhanced OA progression under the surgically induced OA model in mice. Mechanistically, forced expression of Cbfβ rescued Type II collagen (Col2α1) and Runx1 expression in Cbfβ-deficient chondrocytes. TGF-β1-mediated Col2α1 expression failed despite the p-Smad3 activation under TGF-β1 treatment in Cbfβ-deficient chondrocytes. Cbfβ protected Runx1 from proteasomal degradation through Cbfβ/Runx1 complex formation. These results indicate that Cbfβ is a novel anabolic regulator for cartilage homeostasis, suggesting that Cbfβ could protect OA development by maintaining the integrity of the TGF-β signaling pathway in articular cartilage.

Development of a COX-2-Selective Fluorescent Probe for the Observation of Early Intervertebral Disc Degeneration.

Cyclooxygenase-2 (COX-2) is a biomolecule known to be overexpressed in inflammation. Therefore, it has been considered a diagnostically useful marker in numerous studies. In this study, we attempted to assess the correlation between COX-2 expression and the severity of intervertebral disc (IVD) degeneration using a COX-2-targeting fluorescent molecular compound that had not been extensively studied. This compound, indomethacin-adopted benzothiazole-pyranocarbazole (IBPC1), was synthesized by introducing indomethacin-a compound with known selectivity for COX-2-into a phosphor with a benzothiazole-pyranocarbazole structure. IBPC1 exhibited relatively high fluorescence intensity in cells pretreated with lipopolysaccharide, which induces inflammation. Furthermore, we observed significantly higher fluorescence in tissues with artificially damaged discs (modeling IVD degeneration) compared to normal disc tissues. These findings indicate that IBPC1 can meaningfully contribute to the study of the mechanism of IVD degeneration in living cells and tissues and to the development of therapeutic agents.

AGE-REALTED MACULAR DEGENERATION AND SERUM LEPTIN: A CASE–CONTROL STUDY

Objective: The objective of this study was to evaluate the association of serum leptin levels with presence and severity of age-related macular degeneration (AMD). Methods: A hospital-based case–control study conducted on 84 patients (42 cases and 42 controls) of either sex complaining of diminution of vision aged 40 years and above between August 2019 and 2021. Results: Mean serum leptin level in cases was 1.55±0.99 ng/mL and control was 2.11±0.88 ng/mL (p&lt;0.008). The serum leptin level was negatively correlated with early (1.06±0.99 ng/mL), intermediate (0.50±0.08 ng/mL), and dry age-related macular degeneration (ARMD) (0.29±0.12 ng/mL). However, we found higher serum leptin levels in exudative ARMD (2.58±0.99 ng/mL). Maximum number of cases were of exudative AMD (42.86%) followed by early AMD (33.34%) and intermediate and dry AMD (11.91% each). Conclusion: We found a decrease in serum leptin levels as disease severity increases from the early AMD to intermediate AMD and Dry AMD. However, the levels of serum leptin levels were higher in patients with exudative AMD. This may be due to some pathological process that is different in dry and exudative AMD. This can form the basis for further research in future.

Knee cartilage injuries in athletes

Acute and chronic cartilage injuries are often encountered in professional and recreational athletes. They can compromise the athlete's performance and career and are considered apotential risk factor for early joint degeneration. Incidence of cartilage injury in athletes, understanding of cartilage composition, injury mechanism and suitable diagnostic imaging are summarized and established therapeutic procedures, postoperative imaging including detection of relevant complications and assessment of reasonable indications for follow-up examinations are described. Original research and review articles were analyzed. Cartilage injury can mimic meniscal or ligamentous injury and cannot be ruled out by clinical examination alone. Magnetic resonance imaging (MRI) is the method of choice to (1)detect (sensitivity 87-93%, specificity 94-99%) and grade cartilage lesions to facilitate choice of therapy and (2)to exclude concomitant injuries that require treatment to improve the prognosis of the chosen cartilage therapy. Postoperatively MRI allows noninvasive assessment of the repaired cartilage tissue and is an appropriate method to detect therapeutically relevant complications. Knowledge of mechanisms and appearance of cartilage injuries, current cartilage repair techniques and their imaging is crucial for the medical care of athletes.