Bright Quantum Dot Single-Photon Emitters at Telecom Bands Heterogeneously Integrated on Si.

Whereas the Si photonic platform is highly attractive for scalable optical quantum information processing, it lacks practical solutions for efficient photon generation. Self-assembled semiconductor quantum dots (QDs) efficiently emit photons in the telecom bands (1460-1625 nm) and allow for heterogeneous integration with Si. In this work, we report on a novel, robust, and industry-compatible approach for achieving single-photon emission from InAs/InP QDs heterogeneously integrated with a Si substrate. As a proof of concept, we demonstrate a simple vertical emitting device, employing a metallic mirror beneath the QD emitter, and experimentally obtained photon extraction efficiencies of ∼10%. Nevertheless, the figures of merit of our structures are comparable with values previously only achieved for QDs emitting at shorter wavelength or by applying technically demanding fabrication processes. Our architecture and the simple fabrication procedure allows for the demonstration of high-purity single-photon generation with a second-order correlation function at zero time delay, g (2)(τ = 0) < 0.02, without any corrections at continuous wave excitation at the liquid helium temperature and preserved up to 50 K. For pulsed excitation, we achieve the as-measured g (2)(0) down to 0.205 ± 0.020 (0.114 ± 0.020 with background coincidences subtracted).

The role of Meteorin-like in skeletal development and bone fracture healing.

Meteorin-like protein (Metrnl), homologous to the initially identified neurotrophic factor Meteorin, is a secreted, multifunctional protein. Here we used mouse models to investigate Metrnl's role in skeletal development and bone fracture healing. During development Metrnl was expressed in the perichondrium and primary ossification center. In neonates, single cell RNA-seq of diaphyseal bone demonstrated strongest expression of Metrnl transcript by osteoblasts. In vitro, Metrnl was osteoinductive, increasing osteoblast differentiation and mineralization in tissue culture models. In vivo, loss of Metrnl expression resulted in no change in skeletal metrics in utero, at birth, or during postnatal growth. Six-week-old Metrnl-null mice displayed similar body length, body weight, tibial length, femoral length, BV/TV, trabecular number, trabecular thickness, and cortical thickness as littermate controls. In 4-month-old mice, lack of Metrnl expression did not change structural stiffness, ultimate force, or energy to fracture of femora under 3-point-bending. Last, we investigated the role of Metrnl in bone fracture healing. Metrnl expression increased in response to tibial injury, however, loss of Metrnl expression did not affect the amount of bone deposited within the healing tissue nor did it change the structural parameters of healing tissue. This work identifies Metrnl as a dispensable molecule for skeletal development. However, the osteoinductive capabilities of Metrnl may be utilized to modulate osteoblast differentiation in cell-based orthopedic therapies.

RNAseq and RNA molecular barcoding reveal differential gene expression in cortical bone following hindlimb unloading in female mice.

Disuse-induced bone loss is seen following spinal cord injury, prolonged bed rest, and exposure to microgravity. We performed whole transcriptomic profiling of cortical bone using RNA sequencing (RNAseq) and RNA molecular barcoding (NanoString) on a hindlimb unloading (HLU) mouse model to identify genes whose mRNA transcript abundances change in response to disuse. Eleven-week old female C57BL/6 mice were exposed to ambulatory loading or HLU for 7 days (n = 8/group). Total RNA from marrow-flushed femoral cortical bone was analyzed on HiSeq and NanoString platforms. The expression of several previously reported genes associated with Wnt signaling and metabolism was altered by HLU. Furthermore, the increased abundance of transcripts, such as Pfkfb3 and Mss51, after HLU imply these genes also have roles in the cortical bone's response to altered mechanical loading. Our study demonstrates that an unbiased approach to assess the whole transcriptomic profile of cortical bone can reveal previously unidentified mechanosensitive genes and may eventually lead to novel targets to prevent disuse-induced osteoporosis.

Tmem100- and Acta2-Lineage Cells Contribute to Implant Osseointegration in a Mouse Model.

Metal implants are commonly used in orthopedic surgery. The mechanical stability and longevity of implants depend on adequate bone deposition along the implant surface. The cellular and molecular mechanisms underlying peri-implant bone formation (ie, osseointegration) are incompletely understood. Herein, our goal was to determine the specific bone marrow stromal cell populations that contribute to bone formation around metal implants. To do this, we utilized a mouse tibial implant model that is clinically representative of human joint replacement procedures. Using a lineage-tracing approach, we found that both Acta2.creERT2 and Tmem100.creERT2 lineage cells are involved in peri-implant bone formation, and Pdgfra- and Ly6a/Sca1-expressing stromal cells (PαS cells) are highly enriched in both lineages. Single-cell RNA-seq analysis indicated that PαS cells are quiescent in uninjured bone tissue; however, they express markers of proliferation and osteogenic differentiation shortly after implantation surgery. Our findings indicate that PαS cells are mobilized to repair bone tissue and participate in implant osseointegration after surgery. Biologic therapies targeting PαS cells might improve osseointegration in patients undergoing orthopedic procedures. © 2021 American Society for Bone and Mineral Research (ASBMR).

An osteocalcin-deficient mouse strain without endocrine abnormalities.

Osteocalcin (OCN), the most abundant noncollagenous protein in the bone matrix, is reported to be a bone-derived endocrine hormone with wide-ranging effects on many aspects of physiology, including glucose metabolism and male fertility. Many of these observations were made using an OCN-deficient mouse allele (Osc-) in which the 2 OCN-encoding genes in mice, Bglap and Bglap2, were deleted in ES cells by homologous recombination. Here we describe mice with a new Bglap and Bglap2 double-knockout (dko) allele (Bglap/2p.Pro25fs17Ter) that was generated by CRISPR/Cas9-mediated gene editing. Mice homozygous for this new allele do not express full-length Bglap or Bglap2 mRNA and have no immunodetectable OCN in their serum. FTIR imaging of cortical bone in these homozygous knockout animals finds alterations in the collagen maturity and carbonate to phosphate ratio in the cortical bone, compared with wild-type littermates. However, µCT and 3-point bending tests do not find differences from wild-type littermates with respect to bone mass and strength. In contrast to the previously reported OCN-deficient mice with the Osc-allele, serum glucose levels and male fertility in the OCN-deficient mice with the Bglap/2pPro25fs17Ter allele did not have significant differences from wild-type littermates. We cannot explain the absence of endocrine effects in mice with this new knockout allele. Possible explanations include the effects of each mutated allele on the transcription of neighboring genes, or differences in genetic background and environment. So that our findings can be confirmed and extended by other interested investigators, we are donating this new Bglap and Bglap2 double-knockout strain to the Jackson Laboratories for academic distribution.

Single-Cell RNA Sequencing of Calvarial and Long-Bone Endocortical Cells.

Single-cell RNA sequencing (scRNA-Seq) is emerging as a powerful technology to examine transcriptomes of individual cells. We determined whether scRNA-Seq could be used to detect the effect of environmental and pharmacologic perturbations on osteoblasts. We began with a commonly used in vitro system in which freshly isolated neonatal mouse calvarial cells are expanded and induced to produce a mineralized matrix. We used scRNA-Seq to compare the relative cell type abundances and the transcriptomes of freshly isolated cells to those that had been cultured for 12 days in vitro. We observed that the percentage of macrophage-like cells increased from 6% in freshly isolated calvarial cells to 34% in cultured cells. We also found that Bglap transcripts were abundant in freshly isolated osteoblasts but nearly undetectable in the cultured calvarial cells. Thus, scRNA-Seq revealed significant differences between heterogeneity of cells in vivo and in vitro. We next performed scRNA-Seq on freshly recovered long bone endocortical cells from mice that received either vehicle or sclerostin-neutralizing antibody for 1 week. We were unable to detect significant changes in bone anabolism-associated transcripts in immature and mature osteoblasts recovered from mice treated with sclerostin-neutralizing antibody; this might be a consequence of being underpowered to detect modest changes in gene expression, because only 7% of the sequenced endocortical cells were osteoblasts and a limited portion of their transcriptomes were sampled. We conclude that scRNA-Seq can detect changes in cell abundance, identity, and gene expression in skeletally derived cells. In order to detect modest changes in osteoblast gene expression at the single-cell level in the appendicular skeleton, larger numbers of osteoblasts from endocortical bone are required. © 2020 American Society for Bone and Mineral Research.

Proteolysis and cartilage development are activated in the synovium after surgical induction of post traumatic osteoarthritis.

Anterior cruciate ligament (ACL) transection surgery in the minipig induces post-traumatic osteoarthritis (PTOA) in a pattern similar to that seen in human patients after ACL injury. Prior studies have reported the presence of cartilage matrix-degrading proteases, such as Matrix metalloproteinase-1 (MMP-1) and A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), in the synovial fluid of injured or arthritic joints; however, the tissue origin of these proteases is unknown. The objective of this study was to identify transcriptional processes activated in the synovium after surgical induction of PTOA with ACL transection, and to determine if processes associated with proteolysis were enriched in the synovium after ACL transection. Unilateral ACL transection was performed in adolescent Yucatan minipigs and synovium samples were collected at 1, 5, 9, and 14 days post-injury. Transcriptome-wide gene expression levels were determined using bulk RNA-Sequencing in the surgical animals and control animals with healthy knees. The greatest number of transcripts with significant changes was observed 1 day after injury. These changes were primarily associated with cellular proliferation, consistent with measurements of increased cellularity of the synovium at the two-week time point. At five to 14 days, the expression of transcripts relating to proteolysis and cartilage development was significantly enriched. While protease inhibitor-encoding transcripts (TIMP2, TIMP3) represented the largest fraction of protease-associated transcripts in the uninjured synovium, protease-encoding transcripts (including MMP1, MMP2, ADAMTS4) predominated after surgery. Cartilage development-associated transcripts that are typically not expressed by synovial cells, such as ACAN and COMP, were enriched in the synovium following ACL-transection. The upregulation in both catabolic processes (proteolysis) and anabolic processes (cartilage development) suggests that the synovium plays a complex, balancing role in the early response to PTOA induction.

Evaluation of trabecular bone microstructure of mandibular condyle in edentulous, unilateral edentulous and fully dentate patients using cone-beam computed tomography.

BACKGROUND: The aim of this study was to compare the trabecular bone microstructure of the mandibular condyle in edentulous, unilateral edentulous (Kennedy Class II), and fully dentate patients. MATERIALS AND METHODS: The study used the cone-beam computed tomography (CBCT) images of 17 fully dentate (34 condyles), 16 edentulous (32 condyles), and 17 unilateral edentulous patients (34 condyles) aged 19 to 80 years. The trabecular bone microstructure of the mandibular condyle was evaluated on 8 consecutive cross-sectional images of these patients. In the microstructure analysis, structural model index (SMI), ellipsoid factor (EF), bone volume fraction (BV/TV), trabecular thickness (Tb.Th) and trabecular seperation (Tb.Sp) were measured. RESULTS: There was no significant difference between the mean SMI, BV/TV, EF and Tb.Th microstructure values of each group (p = 0.243, p = 0.095, p = 0.962, p = 0.095, respectively). However, there was significant difference in terms of mean Tb.Sp between the groups (p = 0.021). The trabecular structure in all three groups was more rod-shaped. No correlation was found between age factor and microstructure values. CONCLUSIONS: Considering the in vivo microstructure analysis of CBCT images, it can be said that teeth loss does not have a significant effect on the microstructure parameters excluding Tb.Sp of mandible condyles and does not affect mandibular condyle trabecular endurance.

Cocaine- and amphetamine-regulated transcript promoter regulated by nicotine in nerve growth factor-treated PC12 cells.

Nicotine and cocaine- and amphetamine-regulated transcripts (CART) have several overlapping functions, such as the regulation of reward, feeding behavior, stress response, and anxiety. Previous studies showed that nicotine regulates CART expression in various brain regions. However, the molecular mechanisms underlying this regulation are not known. This study investigated the regulatory effect of nicotine on promoter activity of the CART gene in PC12 cells, which were differentiated into a neuronal phenotype by nerve growth factor (NGF) treatment. Two vectors containing reporter genes (Gaussia luciferase or mCherry) and the 1,140-bp upstream of the transcriptional start site of the mouse CART gene are used to analyze the CART promoter activity. Transient transfection of PC12 cells with either vector displayed strong promoter activity in both undifferentiated and differentiated PC12 cells. CART promoter activity in the PC12 cell line is increased by forskolin or NGF treatment. In differentiated PC12 cells, exposure to 50 nM nicotine for 6 h increased CART promoter activity. However, treatment with higher nicotine doses for 6 h and treatment with all nicotine doses for 24 h showed no effect. A nicotine concentration of 50 nM is comparable to brain nicotine levels experienced by chronic smokers over long periods of time. Taken together, these data indicate that nicotine may exert some of its actions through the regulation of CART transcription in the brain.

The Unmixing Problem: A Guide to Applying Single-Cell RNA Sequencing to Bone.

Bone is composed of a complex mixture of many dynamic cell types. Flow cytometry and in vivo lineage tracing have offered early progress toward deconvoluting this heterogeneous mixture of cells into functionally well-defined populations suitable for further studies. Single-cell sequencing is poised as a key complementary technique to better understand the cellular basis of bone metabolism and development. However, single-cell sequencing approaches still have important limitations, including transcriptional effects of cell isolation and sparse sampling of the transcriptome, that must be considered during experimental design and analysis to harness the power of this approach. Accounting for these limitations requires a deep knowledge of the tissue under study. Therefore, with the emergence of accessible tools for conducting and analyzing single-cell RNA sequencing (scRNA-seq) experiments, bone biologists will be ideal leaders in the application of scRNA-seq to the skeleton. Here we provide an overview of the steps involved with a single-cell sequencing analysis of bone, focusing on practical considerations needed for a successful study. © 2019 American Society for Bone and Mineral Research.

Gain-of-function mutation of microRNA-140 in human skeletal dysplasia.

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression. Heterozygous loss-of-function point mutations of miRNA genes are associated with several human congenital disorders1-5, but neomorphic (gain-of-new-function) mutations in miRNAs due to nucleotide substitutions have not been reported. Here we describe a neomorphic seed region mutation in the chondrocyte-specific, super-enhancer-associated MIR140 gene encoding microRNA-140 (miR-140) in a novel autosomal dominant human skeletal dysplasia. Mice with the corresponding single nucleotide substitution show skeletal abnormalities similar to those of the patients but distinct from those of miR-140-null mice6. This mutant miRNA gene yields abundant mutant miR-140-5p expression without miRNA-processing defects. In chondrocytes, the mutation causes widespread derepression of wild-type miR-140-5p targets and repression of mutant miR-140-5p targets, indicating that the mutation produces both loss-of-function and gain-of-function effects. Furthermore, the mutant miR-140-5p seed competes with the conserved RNA-binding protein Ybx1 for overlapping binding sites. This finding may explain the potent target repression and robust in vivo effect by this mutant miRNA even in the absence of evolutionary selection of miRNA-target RNA interactions, which contributes to the strong regulatory effects of conserved miRNAs7,8. Our study presents the first case of a pathogenic gain-of-function miRNA mutation and provides molecular insight into neomorphic actions of emerging and/or mutant miRNAs.

Distinct molecular pathways mediate Mycn and Myc-regulated miR-17-92 microRNA action in Feingold syndrome mouse models.

Feingold syndrome is a skeletal dysplasia caused by loss-of-function mutations of either MYCN (type 1) or MIR17HG that encodes miR-17-92 microRNAs (type 2). Since miR-17-92 expression is transcriptionally regulated by MYC transcription factors, it has been postulated that Feingold syndrome type 1 and 2 may be caused by a common molecular mechanism. Here we show that Mir17-92 deficiency upregulates TGF-ß signaling, whereas Mycn-deficiency downregulates PI3K signaling in limb mesenchymal cells. Genetic or pharmacological inhibition of TGF-ß signaling efficiently rescues the skeletal defects caused by Mir17-92 deficiency, suggesting that upregulation of TGF-ß signaling is responsible for the skeletal defect of Feingold syndrome type 2. By contrast, the skeletal phenotype of Mycn-deficiency is partially rescued by Pten heterozygosity, but not by TGF-ß inhibition. These results strongly suggest that despite the phenotypical similarity, distinct molecular mechanisms underlie the pathoetiology for Feingold syndrome type 1 and 2.

A somatic GNA11 mutation is associated with extremity capillary malformation and overgrowth.

BACKGROUND: Capillary malformation is a cutaneous vascular anomaly that is present at birth, darkens over time, and can cause overgrowth of tissues beneath the stain. The lesion is caused by a somatic activating mutation in GNAQ. In a previous study, we were unable to identify a GNAQ mutation in patients with a capillary malformation involving an overgrown lower extremity. We hypothesized that mutations in GNA11 or GNA14, genes closely related to GNAQ, also may cause capillary malformations. METHODS: Human capillary malformation tissue obtained from 8 patients that had tested negative for GNAQ mutations were studied. Lesions involved an extremity (n = 7) or trunk (n = 1). Droplet digital PCR (ddPCR) was used to detect GNA11 or GNA14 mutant cells (p.Arg183) in the specimens. Single molecule molecular inversion probe sequencing (smMIP-seq) was performed to search for other mutations in GNA11. Mutations were validated by subcloning and sequencing amplimers. RESULTS: We found a somatic GNA11 missense mutation (c.547C > T; p.Arg183Cys) in 3 patients with a diffuse capillary malformation of an extremity. Mutant allelic frequencies ranged from 0.3 to 5.0%. GNA11 or GNA14 mutations were not found in 5 affected tissues or in unaffected tissues (white blood cell DNA). CONCULSIONS: GNA11 mutations are associated with extremity capillary malformations causing overgrowth. Pharmacotherapy that affects GNA11 signaling may prevent the progression of capillary malformations.

The management of adnexal masses in premenopausal patients: a ten-year retrospective study at a single center.

PURPOSE OF INVESTIGATION: To distinguish adnexal masses as benign and malignant, and to thereby identity the suitable surgical method for these masses, in premenopausal women, by retrospectively evaluating over a ten-year period, the diagnostic parameters, such as serum CA 125 and transvaginal ultrasonography (TVS), in combination with the presence of ascites in the abdomen. MATERIALS AND METHODS: The study was conducted with 255 premenopausal patients diagnosed with adnexal masses who had been admitted to the Gaziantep University Faculty of Medicine, Clinic of Gynecology and Obstetrics, between January 2003 and January 2013. Data collected from these patients included age, menopausal state, information regarding the presence of ascites, ultrasound findings, and serum CA 125 levels. RESULTS: The mean age of the women included in the study was 32.79 ± 8.11 (range: 18-51) years. Based on the criteria mentioned above, 152 patients were treated by laparoscopy based on a strong suspicion of benign mass, while 103 patients were treated by laparotomy, based on a strong suspicion of malignant mass. CA 125 values did not have a significant effect on malignancy risk. Based on the TVS results, three malignant masses were reported postoperatively in the patient group strongly suspected to have benign masses, while five benign masses were reported postoperatively in the patient group strongly suspected to have malignant masses.An evaluation of the present diagnostic method showed that the TVS has a positive predictive value (PPV) of 94.19% in identifying malignant masses, and a negative predictive value (NPV) of 98.22% in identifying benign masses. CONCLUSION: TVS and CA 125, along with an evaluation of menopausal status and ascites, can be an effective approach for diagnosing adnexal masses, and also for determining the proper surgical method to follow.

Assessment of ß-hydroxydeoxyguanosine levels in patients with preeclampsia: a prospective study.

PURPOSE OF INVESTIGATION: To determine the levels of 8-hydroxydeoxyguanosine (8-OHdG) in preeclampsia (PE) using (enzyme-linked immunosorbent assay (ELISA) method. MATERIALS AND METHODS: Twenty-two pregnant women with severe PE, 18 pregnant women with mild PE, and 40 healthy pregnant women, all between 25 and 41 weeks of gestation, were enrolled in this prospective controlled study. 8-OHdG levels in maternal serum were measured using ELISA method. RESULTS: The authors observed no statistically significant difference in 8-OHdG levels between the mild-severe PE and control groups (p = 0.208). CONCLUSION: The present results do not support the concept that 8-OHdG has a role in the etiopathogenesis of PE.

Comparison of the effectiveness of medicinal leech and TENS therapy in the treatment of primary osteoarthritis of the knee : A randomized controlled trial.

OBJECTIVES: The aim of this study was to evaluate the effects of leech therapy in the treatment of knee osteoarthritis in terms of duration of effectiveness and symptom relief and to compare these results with transcutaneous electrical nerve stimulation (TENS) therapy. MATERIAL AND METHODS: This study was designed as a prospective, single center, randomized, single-blind and parallel group study. A total of 90 patients were included in the study, 46 in the leech group and 44 in the TENS group. Primary outcome measures were changes of the pain scores in visual analogue scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) on the measurements day 0, 21 and 180. Secondary outcome measures were the changes in the sub-groups of the WOMAC scores. Five leeches were applied to the affected knee, once every week for 3 weeks. RESULTS: The VAS pain score showed a similar decrease in both groups in the evaluation on day 21 (p < 0.001). The course of the change of the VAS pain score in both groups was similar in the comparisons between groups. Long-term benefits of the TENS therapy group were slightly more than the leech therapy group. All the sub-scores of WOMAC in both therapy groups showed a similar decrease (p = 0.819). Throughout the study this decrease was statistically significant in both groups (p < 0.001). CONCLUSION: Leech therapy relieves symptoms in patients with osteoarthritis of the knee and is as effective as TENS therapy in the management of osteoarthritis of the knee. This treatment has the potential of being an additional or alternative therapy for the non-surgical management of osteoarthritis of the knee.

Evaluation of sialic acid levels in patients with hydatidiform mole: a preliminary study.

PURPOSE OF INVESTIGATION: This study aims to investigate whether hydatidiform mole (HM) disease with malignant potential is significantly associated with increased sialic acid (SA) levels. MATERIALS AND METHODS: A total of 114 women were enrolled in this study. Patients were divided into three groups including HM (Group 1, n = 34), control group including non-pregnant healthy patients (Group 2, n = 42), and another control group including healthy pregnant patients within 12 weeks of gestation (Group 3, n = 38). Serum-free SA levels were measured. RESULTS: There was a statistically significant difference in serum-free SA levels among the groups (p ≤ 0.001). Patients with HM had significantly higher levels compared to the control groups. CONCLUSION: The present study results showed that there was a significant correlation between HM and serum SA level.

The Effect of Garlic Derivatives (S-Allylmercaptocysteine, Diallyl Disulfide, and S-Allylcysteine) on Gentamicin Induced Ototoxicity: An Experimental Study.

OBJECTIVES: Gentamicin is a potent aminoglycoside antibiotic. Ototoxicity and nephrotoxicity are the main side effects which restrict the use of gentamicin. Garlic with its intrinsic antioxidant activity may prove beneficial in prevention from ototoxicity. S-allylmercaptocysteine (SAMC), diallyl disulfide (DD), and S-allylcysteine (SAC) are three active compounds found in garlic. In this study, we investigated the effect of SAMC, DD, and SAC on the ototoxicity induced by gentamicin in rats, by using brainstem evoked response audiometry (BERA). METHODS: Thirty male Wistar rats with intact Preyer's reflex initially weighing 220-260 g were randomly assigned to either the gentamicin injection with SAMC treatment group (Genta-w SAMC), DD treatment group (Genta-w DD), SAC treatment group (Genta-w SAC), gentamicin injection without any active compounds (AC) treatment groups (Genta-w/o AC), or control group (n=6 rats each group). Gentamicin was given 120-mg/kg body weight, intraperitoneally once daily for 25 days to subjects in all groups except the control group. SAMC 100-mg/kg, and DD 50-mg/kg body weight were given intragastrically, and SAC 250-mg/kg body weight was given intraperitoneally once daily to subjects in Genta-w SAMC, and Genta-w DD, and Genta-w SAC groups, respectively during the study. After 25 days hearing thresholds were evaluated by using BERA test. RESULTS: The mean amplitude of auditory thresholds (sensation level [SL]) measured by using BERA for the Genta-w SAMC, Genta-w DD, Genta-w SAC, Genta-w/o AC, and control groups were 22±8, 25±5, 30±9, 54±11, and 10±7 dB SL, respectively (mean±SD). The differences between every active compound group (Genta-w SAMC, Genta-w DD, and Genta-w SAC) and Genta-w/o AC were statistically significant (P<0.016). CONCLUSION: SAMC, DD, and SAC are derivative of garlic seems to attenuate aminoglycoside-induced hearing loss. The effect of SAMC and DD seems to be more prominent than that of SAC.