Clinical characteristics, outcomes and risk factors for mortality in hospitalized diabetes and chronic kidney disease patients after COVID-19 infection following widespread vaccination

BACKGROUND

COVID-19 poses a significant threat to patients with comorbidities, such as diabetes and chronic kidney disease (CKD). China experienced a nationwide COVID-19 endemic from December 2022 to January 2023, which is the first occurrence of such an outbreak following China's widespread administration of COVID-19 vaccinations.

METHODS

A total of 338 patients with diabetes and CKD combined with COVID-19 infection between December 7, 2022 and January 31, 2023 were included in this study. The end follow-up date was February 10, 2023. Univariate analysis and multivariate Cox analysis were used to analyze risk factors for death.

RESULTS

During the 50-day median follow-up period, 90 patients in the study cohort died, for a mortality rate of 26.63%. The median age of the study cohort was 74 years, with a male predominance of 74%. During hospitalization, 21% of patients had incident AKI, 17% of patients experienced stroke, and 40% of patients experienced respiratory failure. Cox proportional hazard regression showed that older age, a diagnosis of severe or critically severe COVID-19 infection, incident AKI and respiratory failure, higher level of average values of fasting glucose during hospitalization, UA, and total bilirubin were independent risk factors for death in our multivariate model.

CONCLUSIONS

These findings highlight the critical importance of identifying and managing comorbid risk factors for COVID-19, especially among the elderly, in order to optimize clinical outcomes, even after COVID-19 vaccination.

Hybrid-Supervised Deep Learning for Proton-Acoustic Reconstruction for 3D In Vivo Proton Dose Verification

PURPOSE/OBJECTIVE(S)

Proton-acoustic (PA) image has shown great potential to provide real-time 3D dose verification of proton therapy. However, the PA image quality suffers from severe limited view artifacts, which significantly impairs its accuracy for dose verification. In this study, we developed a hybrid-supervised deep learning method for PA reconstruction to address the limited-view issues.

MATERIALS/METHODS

Our method consists of two stages. In the first stage, a transformer-based network was proposed to reconstruct initial pressure maps from protoacoustic signals. The network was first trained using supervision by the iteratively reconstructed pressure map and then fine-tuned using transfer learning and self-supervision based on the data fidelity constraint. In the second stage, the PA image was further enhanced by a 3D U-net. The final PA images were converted to dose maps using conversion coefficients derived from CT images. Data from 126 prostate cancer patients treated by proton therapy were collected under an IRB protocol and were split into 86 and 40 patients for model training and testing, respectively. Data of each patient contains the planning CT scan, the corresponding clinical treatment plan, and the dose map calculated by commercial software. The radiofrequency signals were generated by performing proton acoustic simulation based on CT images and the ground truth pressure map derived from the treatment plan. An ultrasound detector matrix with 64 × 64 size and 500kHz central frequency was simulated under the perineum to acquire the signals in the prostate area. In the testing results, the method's accuracy was evaluated using Root-mean-squared-error (RMSE) and structural-similarity-index-measure (SSIM) between the reconstructed and ground truth pressure map and dose distribution.

RESULTS

Testing results showed that the reconstructed pressure map achieved an average RMSE/SSIM of 0.0292/0.96, demonstrating excellent 3D information with details. Dose maps derived from the pressure map achieved an average RMSE/SSIM of 0.018/0.99 with a gamma index of 94.7% and 95.7% for 1%/3 mm and 1%/5 mm criteria compared to the ground truth dose maps. The reconstruction time was 6s, which can be further reduced using GPU.

CONCLUSION

Our study achieves start-of-the-art performance in the challenging task of direct reconstruction from limited-view radiofrequency signals, demonstrating the great promise of PA imaging as a highly efficient and accurate tool for in-vivo 3D proton dose verification. Such high-precision 3D online dose verification can substantially reduce the range uncertainties of proton therapy to significantly improve its precision and outcomes.

Preparation and Photo-Oxidation Aging Behavior of Oriented Polylactic Acid

This study employed solid hot stretching technology to produce successfully specifically oriented polylactic acid (PLA) while investigating the impact of orientation structure on its photo-oxidation aging properties. After orientation, the molecular weight and mechanical properties retention rate of PLA were improved, and the crystallinity (Xc) increased in conjunction with prolonged aging time, while the molecular orientation failed to modify the mechanism responsible for PLA deterioration. Furthermore, an examination regarding the way in which the photo-oxidation stability of PLA was enhanced, demonstrated that the increased Xc and structural orientation were beneficial for delaying the photo-oxidation aging of PLA.

High cyclic tensile stress disrupts the extracellular matrix in human chondrocyte by F-actin cytoskeletal polymerization and reactive oxygen species production

This study aims to explore the mechanism of cyclic tensile stress (CTS) on human chondrocytes (CHs) relating to the reactive oxygen species (ROS) generation and extracellular matrix (ECM) stability in vitro. A well-established CTS model with 5%, 10%, or 20% elongation was performed for CHs stretching. After CTS, the cell viability, total ROS level, main ECM components, matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP), F-actin density, and some anti-oxidative enzymes were analyzed. Additionally, the antioxidant N-acetylcysteine (NAC) and cytochalasin D were used to suppress the ROS production and F-actin polymerization when the CHs underwent CTS, respectively. The treatment of 20% elongation-CST significantly decreased the CH viability and the expressions of collagen II, aggrecan, anti-oxidative enzymes and TIMP3/4, however, it increased the ROS accumulation, F-actin polymerization, and the expression of collagen I and MMP3/13. In contrast, the application of NAC and cytochalasin D could partly rescue the CHs from the injury caused by the high CTS. Therefore, high CTS disrupts the ECM by remodeling the F-actin cytoskeleton and promoting ROS production. Cytochalasin D and NAC are effective in rejecting F-actin cytoskeleton polymerization, and ROS accumulation through a potential synergetic process, which alleviates the ECM injury caused by High CTS.

Adoptive transfer of immunomodulatory M2 macrophages suppresses experimental autoimmune encephalomyelitis in C57BL/6 mice via blockading NF-κB pathway

Macrophages play important roles in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), and M2 macrophage may have anti-inflammatory effects. In this study, we elucidated the roles of M1 and M2 macrophages in the pathogenesis of EAE and the effects of treatment with M2 macrophages that target certain proinflammatory cytokines and with immunomodulatory preparations that beneficially influence the disease course. We found macrophages increased at the onset of clinical signs in the EAE group, consistent with an increased proportion of M1 macrophages and low numbers of M2 macrophages. As the disease progressed and the symptoms worsened, M1 macrophages decreased and M2 macrophages gradually increased until the peak. In the recovery stage, M2 macrophages gradually decreased. Treatment with M2 macrophages inhibited the nuclear factor kappa B (NF-κB) pathway, alleviated the symptoms of EAE, reduced inflammatory cell infiltration and demyelination in the central nervous system and decreased the numbers of macrophages in the spleens. BAY-11-7082, an NF-κB blocking agent, could reduce the total number of macrophages both in vivo and in vitro, effectively prevented EAE development and significantly inhibited EAE symptoms in mice. Our study demonstrates that macrophages may play a crucial role in the pathogenesis of EAE, while M2 macrophages have anti-inflammatory effects. Transfer of M2 macrophages to EAE mice can block the NF-κB pathway successfully and relieve EAE symptoms. Application of NF-κB blockers is useful in the prevention and treatment of EAE.

Erratum: Avalanches triggered by Kelvin-Helmholtz instability in a cylindrical plasma device [Phys. Rev. E 100, 033212 (2019)]

This corrects the article DOI: 10.1103/PhysRevE.100.033212.

MiR-25 overexpression promotes fracture healing by activating the Wnt signaling pathway

OBJECTIVE

To study the mechanism of micro-ribonucleic acid (miR)-25 in regulating the fracture healing in rats.

MATERIALS AND METHODS

A total of 45 male Sprague-Dawley (SD) rats were selected and randomly divided into group A [Phosphate Buffered Saline (PBS), n=15], group B (mimics NC, n=15) and group C (miR-25 mimics, n=15). The fracture model in rats was established via operation in all groups. From 1 d after the successful modeling, 50 μL (2 nmoL) of PBS was intraperitoneally injected into rats in group A, an equal amount of mimics NC was injected into rats in group B, and an equal amount of miR-25 mimics was injected into rats in group C. The above agents were injected once a week for consecutive 6 weeks. Fracture healing in rats was evaluated via X-ray imaging. At the same time, miR-25 expression in the three groups was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Protein expressions of β-catenin, proliferating cell nuclear antigen (PCNA) and bone morphogenetic protein-2 (BMP-2) in the three groups were detected via Western blotting. The OCN-, PCNA- and BMP-2-positive osteoblasts in the three groups were detected via immunohistochemical staining and were further quantified. Moreover, the biomechanical properties of femoral fracture healing in the three groups were analyzed via the 4-point bending flexural test.

RESULTS

The X-ray examination of the femoral fracture healing at postoperative 1 and 7 weeks revealed that the fracture line disappeared, and both callus formation and fracture healing were good in miR-25 mimics group. In PBS group and mimics NC group, a few fracture lines could be observed, and both callus formation and fracture healing were poor. RT-PCR data showed that the expression level of miR-25 significantly increased in the miR-25 mimics group compared with that in the other two groups, and the differences were statistically significant (p<0.01). Western blotting analyses showed upregulated levels of β-catenin, PCNA and BMP-2 in the miR-25 mimics group compared with those in the control group, and the differences were statistically significant (p<0.01). Immunohistochemical staining manifested that the numbers of OCN-, PCNA- and BMP-2-positive osteoblasts in miR-25 mimics group markedly increased compared with that in the other two groups (p<0.01), suggesting that osteoblast differentiation in miR-25 mimics group was affected. The above immunohistochemical results indicated that the osteoblast differentiation at the fracture end in miR-25 mimics group was markedly enhanced compared with that in control groups. The results of the biomechanical test of femur specimens at 7 weeks after operation showed that in miR-25 mimics group, the maximum load, fracture energy and stiffness increased by 188%, 333% and 90%, respectively, compared with those in the PBS group (p<0.01). It is indicated that miR-25 promoted the mechanical properties of fracture healing.

CONCLUSIONS

The overexpression of miR-25 in the fracture in rats promotes fracture healing by activating the Wnt signaling pathway.

Avalanches triggered by Kelvin-Helmholtz instability in a cylindrical plasma device

A profile-evolving simulation of the Controlled Shear Decorrelation Experiment (CSDX) linear device is performed with our newly developed code. The simulation result shows an excellent agreement with the experimental observations of profiles and fluctuations of plasma density and electric potential in the B=1000 G standard discharges, suggesting the mechanism of their evolutions. According to our simulation, an avalanche of plasma density, featuring a rapid destruction of particle profile, is triggered every time the dominant instability transits from near adiabatic collisional drift wave to non-adiabatic Kelvin-Helmholtz instability. The avalanches always start at the point where the local vorticity is the maximum among the whole device. A critical vorticity is found for any avalanche to happen. The avalanches always lead to intermittent particle and heat convective structures outside the main plasma column, and these structures are ejected out as avaloids when zonal flow intensity at birth time is weak.

Diabetes mellitus and risk of hip fractures: a meta-analysis

This meta-analysis revealed that diabetic adults had a twofold greater risk of hip fractures compared with non-diabetic populations, and this association was more pronounced in type 1 diabetes.

INTRODUCTION

The relationship between diabetes mellitus and risk of hip fracture yielded conflicting results. We conducted a meta-analysis to investigate the association between diabetes mellitus and the risk of hip fractures based on observational studies.

METHODS

We conducted a systematic literature search of PubMed and Embase databases through May 2015. We selected cohort and case-control studies providing at least age-adjusted risk ratio (RR) and corresponding 95 % confidence intervals (CI) of hip fractures among diabetic and non-diabetic subjects. Moreover, we pooled the female-to-male RR of hip fractures from studies that reported gender-specific risk estimate in a single study.

RESULTS

Twenty-one studies involving 82,293 hip fracture events among 6,995,272 participants were identified. Diabetes mellitus was associated with an increased risk of hip fractures (RR 2.07; 95 % CI 1.83-2.33) in a random effects model. Subgroup analysis indicated that excess risk of hip fracture was more pronounced in type 1 diabetes (RR 5.76; 95 % CI 3.66-9.07) than that in type 2 diabetes (RR 1.34; 95 % CI 1.19-1.51). The pooled female-to-male RR of hip fractures was 1.09 (95 % CI 0.93-1.28).

CONCLUSIONS

Individuals with diabetes mellitus have an excessive risk of hip fractures, and this relationship is more pronounced in type 1 diabetes. The association between diabetes and hip fracture risk is similar in men and women.

Synthesis of polymer-silica hybrid microparticles with defined geometry using surface initiated atom transfer radical polymerization

In vivo functionalization of the diatom with an initiator site allows grafting from the surface via SI-ATRP.

Overexpression of ubiquitin-specific protease 22 predicts poor survival in patients with early-stage non-small cell lung cancer

Ubiquitin-specific protease 22 (USP22), a novel ubiquitin hydrolase, has been implicated in oncogenesis and cancer progression in various types of human cancer. However, the clinical significance of USP22 expression in non-small cell lung cancer (NSCLC) has not been determined. In the present study, USP22 messenger RNA (mRNA) and protein levels were analyzed by quantitative real-time polymerase chain reaction (PCR) and western blot analysis in 30 cases of NSCLC and in corresponding non-tumor tissue samples. Furthermore, immunohistochemistry was performed to detect USP22 protein expression in 86 primary tumor tissues derived from clinically annotated NSCLC cases at stage I-II. In our analysis we found that both USP22 mRNA and protein levels in NSCLC tissues were significantly higher than those in corresponding non-tumor tissues and that there was a significant correlation between the expression of USP22 mRNA and protein (P=0.000, κ=0.732). In addition, a high-level of USP22 expression was observed in 53.3% (39 out of 86) cases and it was correlated with large tumor size (P=0.029) and lymph node metastasis (P=0.026). Patients with tumors displaying a high-level of USP22 expression showed significantly shorter survival (P=0.006, log-rank test). Importantly, multivariate analysis showed that high USP22 protein expression was an independent prognostic factor for NSCLC patients (P=0.003). In sum, our data suggest that USP22 plays an important role in NSCLC progression at the early stage, and that overexpression of USP22 in tumor tissues could be used as a potential prognostic marker for patients with early clinical stage of NSCLC.

Pharmacological activity of ibuprofen released from mesoporous silica

Novel drug delivery systems (DDS) to improve the pharmacokinetic profile of hydrophobic drugs following oral administration are an area of keen interest in drug research. An ideal DDS should not adversely affect drug activity, be capable of delivering a therapeutic dose of drug, and allow homogenous drug loading and drug release. Mesoporous silica has been proposed for this application, with ibuprofen employed as the model drug. It was hypothesised that mesoporous silica MCM-41 is capable of delivering a pharmacologically therapeutic dose of ibuprofen. Ibuprofen-loaded MCM-41 can be prepared reproducibly at a drug to carrier ratio of 30% (wt/wt). The release profile was seen to be 90% within 2 h. Initial assessment of COX-1 inhibitory activity suggests the absence of adverse effects attributable to drug-carrier interaction. The results of this study provide further evidence in support of the proposed use of mesoporous silica in drug delivery.

Clinical trial: benefits and risks of immunomodulators and maintenance infliximab for IBD-subgroup analyses across four randomized trials

BACKGROUND

Benefits and risks of concomitant immunomodulators and maintenance infliximab in inflammatory bowel disease (IBD) patients have not been adequately evaluated.

AIM

To assess the effect of concomitant immunomodulator and infliximab maintenance therapy using data from four prospective, randomized Phase 3 trials in IBD patients.

METHODS

Overall, 1383 patients from ACCENT I and ACCENT II [luminal and fistulizing Crohn's disease trials] and ACT 1 and ACT 2 [ulcerative colitis trials] were analysed. Patients were treated with placebo or infliximab 5 or 10 mg/kg at weeks 0, 2 and 6 followed by every-8-week maintenance therapy. Clinical response, clinical remission, fistula response, complete fistula response, infection and infusion reaction rates; serum infliximab concentrations and immunogenicity were summarized by baseline concomitant immunomodulator subgroup (use or non-use).

RESULTS

Overall, almost 40% of evaluated IBD patients received concomitant immunomodulators. Efficacy, infection, and serious infection rates were generally similar in patients who received maintenance therapy with or without concomitant immunomodulators. There were no consistent differences in serum infliximab concentrations with or without immunomodulators in patients who received scheduled maintenance therapy. Concomitant immunomodulators reduced infusion reactions and immunogenicity.

CONCLUSION

Concomitant immunomodulators did not improve efficacy or pharmacokinetics in IBD patients who received maintenance infliximab.

Clinical trial: benefits and risks of immunomodulators and maintenance infliximab for IBD-subgroup analyses across four randomized trials

BACKGROUND

Benefits and risks of concomitant immunomodulators and maintenance infliximab in inflammatory bowel disease (IBD) patients have not been adequately evaluated.

AIM

To assess the effect of concomitant immunomodulator and infliximab maintenance therapy using data from four prospective, randomized Phase 3 trials in IBD patients.

METHODS

Overall, 1383 patients from ACCENT I and ACCENT II [luminal and fistulizing Crohn's disease trials] and ACT 1 and ACT 2 [ulcerative colitis trials] were analysed. Patients were treated with placebo or infliximab 5 or 10 mg/kg at weeks 0, 2 and 6 followed by every-8-week maintenance therapy. Clinical response, clinical remission, fistula response, complete fistula response, infection and infusion reaction rates; serum infliximab concentrations and immunogenicity were summarized by baseline concomitant immunomodulator subgroup (use or non-use).

RESULTS

Overall, almost 40% of evaluated IBD patients received concomitant immunomodulators. Efficacy, infection, and serious infection rates were generally similar in patients who received maintenance therapy with or without concomitant immunomodulators. There were no consistent differences in serum infliximab concentrations with or without immunomodulators in patients who received scheduled maintenance therapy. Concomitant immunomodulators reduced infusion reactions and immunogenicity.

CONCLUSION

Concomitant immunomodulators did not improve efficacy or pharmacokinetics in IBD patients who received maintenance infliximab.

Favorable effects of lacrimal plugs in patients with an anophthalmic socket

BACKGROUND

The use of punctal plugs in the treatment of dry eyes is well established. Anophthalmic patients have less tears in the anophthalmic socket in comparison to their normal side, due to an absent corneal reflex (Lee & Elsie, 1981a,b). Many of those patients complain of dry eye symptoms, even when they are treated with tear replacement therapy. The authors wished to examine whether they could improve their dry socket complaints with punctal plugs.

PURPOSE

To evaluate the clinical efficacy and tolerability of punctal plug (Smart Plugs) insertion in anophthalmic patients with symptoms of dry eye.

PATIENTS AND METHODS

Interventional case series. Fifteen anophthalmic patients with dry eye symptoms, a Schirmer test of less than 3 mm and an open lacrimal passage were examined before and after insertion of punctal plugs. The patients were asked for their subjective evaluation of the treatment and were examined to evaluate the change. Schirmer tests were compared. Bacterial cultures were taken at both visits.

RESULTS

Schirmer results of less than 3 mm in the anophthalmic socket were obtained in 75% of patients with dry eyes symptoms; 87% of patients in whom punctal plugs were inserted reported an improvement in dry eye sensation. More than half of the patients demonstrated less discharge (p < or = 0.05). Schirmer tests improved from 1.4 mm to 1.9 mm (p < or = 0.05). Patients with a Schirmer outcome of 2 mm or more tended to have less pathogenic bacterial cultures (p = 0.11).

CONCLUSION

Punctal plugs improve the symptoms and signs of dry socket. Punctal plugs seem to reduce the pathogenic bacterial growth in the anophthalmic socket.

Optimal screw diameter for interference fixation in a bone tunnel: a porcine model

The study investigates the optimal interference screw dimensions required to secure a tendon graft in a bone tunnel. A standard 8 mm pig flexor-tendon graft was inserted into a standard open-ended 8 mm bone tunnel of a porcine distal femur and secured using either 7 mm, 8 mm or 9 mm diameter metal interference screws (Arthrex Inc, Naples, FL). The construct was tested to failure using a Shimadzu ASG 10KN Universal Material Testing Machine (Shimadzu, Tokyo, Japan). Load and mode of construct failure were recorded for 37 individual constructs. There was no significant difference in the load at failure between the 7 mm screw (192 N; range 151-232) and 8 mm screw (181 N; range 150-212) (p>0.05). There was a significant difference between the 7 mm screw and the 9 mm screw (109 N; range 67-151) (p=0.006) and between the 8 mm screw and the 9 mm screw (p=0.015). When using a 9 mm screw, 100% of the constructs failed by cut out of the graft at the tunnel opening. The 7 mm constructs failed by slippage of the tendon from the bone tunnel in 83% of cases, with only 17% failing by cut out at the tunnel opening. The 8 mm constructs demonstrated a mixture of failure modes, with slippage occurring in 58% of cases, cut out in 38% and failure of the graft substance in one case (4%). In this model, screw diameters equal to or 1 mm less than the tunnel/tendon diameter provides better fixation than using a screw 1 mm larger. The mode of failure differs for each of these screws.

Vitrectomy to remove a posteriorly dislocated endocapsular tension ring

We treated a patient who had a posteriorly dislocated endocapsular ring associated with decreased vision and intravitreal cortical remnants. The ring was removed by uneventful pars plana vitrectomy. By the last examination, best corrected visual acuity had improved to 6/12 and intraocular pressure had stabilized to within normal limits. A posteriorly dislocated endocapsular ring is a rare complication of cataract surgery. Its removal by pars plana vitrectomy under direct observation is effective and safe.

Intraocular pressure and photorefractive keratectomy: a comparison of three different tonometers

PURPOSE

To evaluate the intraocular pressure (IOP) with three different instruments, Goldmann applanation tonometer (GAT), noncontact tonometer, and Tono-Pen after photorefractive keratectomy (PRK) for myopia.

METHODS

A prospective case series study to evaluate preoperative and postoperative IOP measurements of 149 eyes at 12 months. We performed GAT, noncontact tonometry, Tono-Pen central, and Tono-Pen temporal periphery measurements. We also performed measurements of the central corneal thickness (CCT) by ultrasonic pachymetry and keratometry. Pre-operative IOP reading served as control for all studies.

RESULTS

After PRK, IOP reading was significantly reduced in the treated eyes when compared with the control measurements (11.87+/-1.73 vs. 13.37+/-1.52 mm Hg, p<0.0001 with GAT; 12.07+/-1.6 vs. 13.51+/-1.59 mm Hg, p<0.0001 with noncontact tonometer; 12.18+/-1.6 vs. 13.48+/-1.55 mm Hg, p<0.0001 with Tono-Pen central; 13.48+/-1.65 vs. 13.71+/-1.56 Hg, p<0.0104 with Tono-Pen temporal periphery). There was also a significant correlation between IOP reading changes measured by GAT, noncontact tonometer, Tono-Pen central, and change of CCT and between reduction of IOP reading and keratometry (r2>0.39, p<0.0001 for each). The correlation between IOP reading change by Tono-Pen temporal periphery and CCT was also significant but r2 value was only 0.034. Tono-Pen temporal periphery postoperative IOP measurements had the best correlation with preoperative GAT IOP (r2 = 0.57, p<0.0001).

CONCLUSIONS

PRK reduced IOP reading as measured by GAT, noncontact tonometer, and Tono-Pen central; less so when measured by Tono-Pen temporal periphery. Early detection of glaucoma and IOP follow-up in glaucoma patients may be done best by peripheral Tono-Pen measurements over the nonablated cornea.

Neonatal lethality in mice deficient in XCE, a novel member of the endothelin-converting enzyme and neutral endopeptidase family

XCE, a new member of the endothelin-converting enzyme and neutral endopeptidase family, is preferentially expressed in specific areas of the central nervous system including spinal chord and medulla. To elucidate the importance and function of XCE, we disrupted its gene in mouse embryonic stem cells by homologous recombination and created mice deficient in XCE. The resulting phenotype is characterized by neonatal lethality. All XCE -/- homozygous mice died of respiratory failure shortly after birth, and in most cases their lungs were never ventilated. Apart from the atelectasis, anatomical and histological examinations of embryonic day 18.5 XCE -/- embryos and newborn homozygotes did not reveal any obvious abnormalities in organs and tissues. Malformations that are related to the knock-out were also not found in the skeletons of XCE -/- mice. In addition, XCE knock-out animals showed no deficiency of pulmonary surfactant proteins and had normal heart beat frequencies. Taken together, our results demonstrate that XCE is an essential gene. The phenotype of the XCE-deficient mice together with the central nervous system-specific expression further suggest that XCE may play a vital role in the control of respiration.

Mice deficient for tenascin-R display alterations of the extracellular matrix and decreased axonal conduction velocities in the CNS

Tenascin-R (TN-R), an extracellular matrix glycoprotein of the CNS, localizes to nodes of Ranvier and perineuronal nets and interacts in vitro with other extracellular matrix components and recognition molecules of the immunoglobulin superfamily. To characterize the functional roles of TN-R in vivo, we have generated mice deficient for TN-R by homologous recombination using embryonic stem cells. TN-R-deficient mice are viable and fertile. The anatomy of all major brain areas and the formation and structure of myelin appear normal. However, immunostaining for the chondroitin sulfate proteoglycan phosphacan, a high-affinity ligand for TN-R, is weak and diffuse in the mutant when compared with wild-type mice. Compound action potential recordings from optic nerves of mutant mice show a significant decrease in conduction velocity as compared with controls. However, at nodes of Ranvier there is no apparent change in expression and distribution of Na+ channels, which are thought to bind to TN-R via their beta2 subunit. The distribution of carbohydrate epitopes of perineuronal nets recognized by the lectin Wisteria floribunda or antibodies to the HNK-1 carbohydrate on somata and dendrites of cortical and hippocampal interneurons is abnormal. These observations indicate an essential role for TN-R in the formation of perineuronal nets and in normal conduction velocity of optic nerve.

Major histocompatibility complex class II molecules function as a template for the processing of a partially processed insulin peptide into a T-cell epitope

Our understanding of how an autoantigen is processed and presented during the development of a major histocompatibility complex (MHC) class II-dependent and T-cell-mediated autoimmune disease, such as IDDM, is incompletely understood. We have used insulin as a model autoantigen in IDDM to address the question of whether MHC class II molecules play a role in the generation and/or preservation of an autoantigen peptide that stimulates T-cell activation. Analyses of the requirement of I-Ad class II molecules in the processing of the partially processed porcine insulin peptide A1-A14/B1-B16 demonstrate that the binding of this peptide to I-Ad is essential for it to be further processed and tailored into a T-cell epitope. Based on our observations, we propose a two-step model for insulin processing in which insulin is first processed by an enzyme(s) into an intermediate peptide that binds to class II and then class II functions as a template to guide the processing of this partially processed peptide by cathepsin D into a T-cell epitope. Our data further underscore the important realization that MHC class II-directed processing of an autoantigen (e.g., insulin) may regulate 1) the relative immunodominance of T-cell determinants in an autoantigen, 2) the self-reactivity to cryptic T-cell epitopes in autoantigens, and 3) the susceptibility to autoimmune disease.

Synthesis and pharmacology of highly selective carboxy and phosphono isoxazole amino acid AMPA receptor antagonists

(RS)-2-Amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA, 5) and the selective AMPA receptor antagonist (RS)-2-amino-3-[3-(carboxymethoxy)-5-methyl-4-isoxazolyl]propionic acid (AMOA, 7) have been used as leads for the design and synthesis of a number of potential AMPA receptor antagonists. Two parallel series of AMOA analogs were synthesized, containing either a distal carboxylic acid (compounds 8b-g and 11b) or a phosphonic acid (compounds 9a-g, 10c, and 11c). Pharmacological characterization of the synthesized compounds was carried out using a series of receptor binding assays and by in vitro electrophysiological experiments using the rat cortical slice model. The two analogs with a tert-butyl substituent, (RS)-2-amino-3-[5-tert-butyl-3-(carboxymethoxy)-4-isoxazolyl]pr opi onic acid (ATOA, 8b) and the corresponding phosphonic acid analog ATPO (9b), were the most potent and selective AMPA antagonists within each series. ATOA and ATPO showed IC50 values of 150 and 28 microM, respectively, toward AMPA-induced depolarizations in the cortical slice model compared to IC50 = 320 microM for the parent compound, AMOA. These two new competitive AMPA antagonists were significantly more selective than AMOA, showing no antagonism (up to 1 mM) toward NMDA-induced responses, whereas AMOA (at 1mM) showed weak (19%) inhibition toward NMDA-induced responses. The structure-activity relationships for the two series of compounds revealed considerable differences with respect to the substituents effects, and the phosphonic acid analogs generally exhibited significantly higher potencies compared to the carboxylic acid analogs.

Efficient control of gene expression by single step integration of the tetracycline system in transgenic mice

Tetracycline-regulated gene expression in eukaryotic cell lines, plants, and transgenic mice has become a powerful tool for the analysis of eukaryotic gene expression and function. The system consists of two plasmids, one encoding the transactivator protein under control of a viral cytomegalovirus promoter, and the second being the tet-operator minimal promoter driving the gene of interest. Here we show that these control elements, when integrated in cis on a single plasmid, allow efficient and tight control of reporter gene expression in vitro and in vivo. Dependent on the route of administration of tetracycline, gene expression can be partially or fully repressed in transgenic mice, whereas removal of the antibiotic induces the reporter gene in various tissues to levels up to 800-fold more than the two-plasmid system. In addition, crossing and analysis of animals transgenic for the individual components of the system are unnecessary, and genetic segregation of the control elements during breeding is prevented.

Cone-rod dysfunction in patients with unexplained reduction in visual acuity

Electrophysiologic tests were performed in 233 patients who complained of reduced visual acuity with no satisfactory clinical explanation. The functional integrity of the retina was assessed from the light- and dark-adapted electroretinogram. Macular function and conduction in the optic nerves were estimated from the flash visual evoked potentials. Of the 233 patients 78 were grouped together on the basis of the electrophysiologic and clinical findings. They were characterized by subnormal electroretinogram responses with the cone system more affected than the rod system. The flash visual evoked potential responses were of abnormal waveform and prolonged implicit times. Most of these patients exhibited normal fundi. The reduction in visual acuity, the degree of electroretinogram deficits and the pattern of the visual evoked potential responses were similar in both eyes of each patient, indicating a symmetric disorder. Slight deterioration of visual acuity and electrophysiologic variables were observed in 37 of the patients who were followed up over a period of up to 8 years. The electrophysiologic findings indicate that about 20% of patients complaining of unexplained reduction in visual acuity were suffering from a diffuse retinal disorder affecting the peripheral retina as well as the macular region. On the basis of electrophysiologic findings and clinical symptoms, we suggest grouping these patients under a new entity: cone-rod dysfunction.

Benzodiazepine-insensitive mice generated by targeted disruption of the gamma 2 subunit gene of gamma-aminobutyric acid type A receptors

Vigilance, anxiety, epileptic activity, and muscle tone can be modulated by drugs acting at the benzodiazepine (BZ) site of gamma-aminobutyric acid type A (GABAA) receptors. In vivo, BZ sites are potential targets for endogenous ligands regulating the corresponding central nervous system states. To assess the physiological relevance of BZ sites, mice were generated containing GABAA receptors devoid of BZ sites. Following targeted disruption of the gamma 2 subunit gene, 94% of the BZ sites were absent in brain of neonatal mice, while the number of GABA sites was only slightly reduced. Except for the gamma 2 subunit, the level of expression and the regional and cellular distribution of the major GABAA receptor subunits were unaltered. The single channel main conductance level and the Hill coefficient were reduced to values consistent with recombinant GABAA receptors composed of alpha and beta subunits. The GABA response was potentiated by pentobarbital but not by flunitrazepam. Diazepam was inactive behaviorally. Thus, the gamma 2 subunit is dispensable for the assembly of functional GABAA receptors but is required for normal channel conductance and the formation of BZ sites in vivo. BZ sites are not essential for embryonic development, as suggested by the normal body weight and histology of newborn mice. Postnatally, however, the reduced GABAA receptor function is associated with retarded growth, sensorimotor dysfunction, and drastically reduced life-span. The lack of postnatal GABAA receptor regulation by endogenous ligands of BZ sites might contribute to this phenotype.

[Mammaplasty immediately after mastectomy for breast cancer]

From March 1990 to March 1994, 7 cases of one stage breast reconstruction with silicone prosthesis after mastectomy for breast cancer were performed in our hospital. All the operations were successful and no operative complication observed. They were followed up for three months to four years. The contour was good, symmetrical, soft to touch and the patients did not complain uncomfortable sensation. The authors propose that immediate reconstruction of the breast be recommended. In this paper, the indications, methods, selection of opportune time for operation and precautions are discussed.

Chemical and molecular classification of Saccharomonospora strains

The results of our experiments showed that the 5'-terminal sequences of 23S rRNAs can be used to distinguish different genera of actinomycetes, including the genera Streptomyces, Micromonospora, Amycolatopsis, and Saccharomonospora. There are small differences (< 1%) among the sequences of some strains belonging to the genera Streptomyces (two strains) and Saccharomonospora (seven strains). On the basis of the results of morphological and biochemical analyses, strain 9022 belongs in the genus Saccharomonospora; however, there are distinct differences in the cell wall compositions and the 5' termini of the 23S rRNA sequences of this strain and members of the genus Saccharomonospora. Hence, strain 9022 cannot be classified in the genus Saccharomonospora.

Mice deficient for the myelin-associated glycoprotein show subtle abnormalities in myelin

Using homologous recombination in embryonic stem cells, we have generated mice with a null mutation in the gene encoding the myelin-associated glycoprotein (MAG), a recognition molecule implicated in myelin formation. MAG-deficient mice appeared normal in motor coordination and spatial learning tasks. Normal myelin structure and nerve conduction in the PNS, with N-CAM overexpression at sites normally expressing MAG, suggested compensatory mechanisms. In the CNS, the onset of myelination was delayed, and subtle morphological abnormalities were detected in that the content of oligodendrocyte cytoplasm at the inner aspect of most myelin sheaths was reduced and that some axons were surrounded by two or more myelin sheaths. These observations suggest that MAG participates in the formation of the periaxonal cytoplasmic collar of oligodendrocytes and in the recognition between oligodendrocyte processes and axons.

Mice lacking the tumour necrosis factor receptor 1 are resistant to TNF-mediated toxicity but highly susceptible to infection by Listeria monocytogenes

Tumour necrosis factor (TNF), jointly referring to TNF alpha and TNF beta, is a central mediator of immune and inflammatory responses; its activities are mediated by two distinct receptors, TNFR1 (p55) and TNFR2 (p75) (reviewed in refs 1-3). The cytoplasmic domains of the TNFRs are unrelated, suggesting that they link to different intracellular signalling pathways. Although most TNF responses have been assigned to one or the other of the TNF receptors (mostly TNFR1), there is no generally accepted model for the physiological role of the two receptor types. To investigate the role of TNFR1 in beneficial and detrimental activities of TNF, we generated TNFR1-deficient mice by gene targeting. We report here that mice homozygous for a disrupted Tnfr1 allele (Tnfr1(0)) are resistant to the lethal effect of low doses of lipopolysaccharide after sensitization with D-galactosamine, but remain sensitive to high doses of lipopolysaccharide. The increased susceptibility of Tnfr1(0)/Tnfr1(0) mutant mice to infection with the facultative intracellular bacterium Listeria monocytogenes indicates an essential role of TNF in nonspecific immunity.

A first instance of human philophthalmosis in Israel

Conjunctivitis due to the trematode Philophthalmus in a 13-year-old Israeli girl is described. A single worm, probably a mature Philophthalmus palpebrarum, was detected on the palpebral conjunctiva of the upper eyelid of the right eye. Removal of the worm resulted in rapid abatement of the ocular symptoms. This is the first documentation of human philophthalmosis in Israel.

Surveillance and care of four Chinese hemophiliacs with human immunodeficiency virus (HIV) infection

Four Chinese hemophiliacs with HIV infection have been followed up in Zhejiang Province since 1985. A plan for optimal care of HIV seropositive patients was proposed, including surveillance and care; clinical follow-up and preventive education of asymptomatic HIV seropositive patients; keeping the disease confidential so as not to stir up unnecessary social unease; propaganda and health education about acquired immunodeficiency syndrome (AIDS); treatment with traditional Chinese medicines; and regular surveillance of family members and medical personnel. This plan is regarded as feasible and effective for the prevention and control of AIDS in China.

Philophthalmus species, probably P. palpebrarum, in Israel: description of the eye fluke from experimental infection

Following a recent incident of human philophthalmosis in Israel, the intramolluscan larval trematode fauna in snails randomly collected from the suspected water source was checked. Of the snails examined, only Melanopsis praemorsa shed cercariae, including a Philophthalmus cercaria. To identify the philophthalmid species involved, chicks were experimentally infected with metacercariae of the trematode, subsequently yielding mature trematodes resembling those of P. palpebrarum. The majority of trematodes obtained, whether from one-worm infections or from multiple-worm infections resulting in a single trematode in one of the eyes, were relatively small and showed only immature eggs in their uteri. This finding suggests that the existing descriptions of two species of Philophthalmus purportedly harbouring eggs with non-oculate miracidia, namely P. palpebrarum and P. nyrocae, are actually based on immature specimens from one-worm infections that precluded cross-fertilisation. If this be true, then all species of the genus Philophthalmus produce eggs that, when mature, contain oculate miracidia. The species encountered in Israel is thus most likely P. palpebrarum.

Processing and presentation of insulin. III. Insulin degrading enzyme: a neutral metalloendoproteinase that is non-homologous to classical endoproteinases mediates the processing of insulin epitopes for helper T cells

Presentation of a protein antigen to T cells generally requires that the antigen be enzymatically processed into an immunogenic peptide(s). The identification of a protease(s) and its mechanism of action in the proteolysis of such an antigen is therefore a primary goal in the study of antigen processing. We show here that insulin degrading enzyme (IDE), a neutral thiol metalloendoproteinase that is structurally non-homologous to the classical metallo, thiol, acid, or serine proteinases, is relatively specific in its proteolytic activity for insulin and digests human insulin (H(I)) into peptides that are presented by murine TA3 B cell antigen presenting cells (APCs) to HI/I-Ad-reactive T cells. These peptides are, however, not presented by fixed TA3 APCs. Anti-IDE mAbs, after their internalization by TA3 cells, significantly inhibit the presentation of H(I) by these APCs. Immunoblotting experiments demonstrate that this inhibition is mediated by the reactivity of these mAbs with a 110 kDa protein, the known M(r) of IDE. These data show that IDE is an endoproteinase that is involved in the processing of insulin and that this IDE-mediated proteolysis is necessary but not sufficient for the recognition of insulin by T cells. Furthermore, we demonstrate that reduction of the disulfide bonds of a pre-processed A-loop containing heterodimeric insulin peptide is required to further process insulin into a T cell epitope.

Normal development and behaviour of mice lacking the neuronal cell-surface PrP protein

PrPC is a host protein anchored to the outer surface of neurons and to a lesser extent of lymphocytes and other cells. The transmissible agent (prion) responsible for scrapie is believed to be a modified form of PrPC. Mice homozygous for disrupted PrP genes have been generated. Surprisingly, they develop and behave normally for at least seven months, and no immunological defects are apparent. It is now feasible to determine whether mice devoid of PrPC can propagate prions and are susceptible to scrapie pathogenesis.

Traumatic central retinal artery occlusion

A healthy 6-year-old boy with a clinical picture of central retinal artery occlusion (CRAO) of his left eye is presented here. The underlying cause was a trauma to the boy's left cheek some 6 months earlier. Possible pathophysiological mechanisms are discussed. To the best of our knowledge, the late onset of traumatic CRAO has not yet been reported in the literature.

Behcet disease: long-term follow-up of three children and review of the literature

Behcet disease is rare in children. There are only two reports of Behcet disease in childhood, describing seven patients. Three pediatric patients are described, in whom the age of onset ranged from 6 to 11 years. Aphthous stomatitis and arthritis were present in all of the patients; genital ulcers, iridocylitis, erythema nodosum, and CNS involvement were present in two patients. Other manifestations included Stevens-Johnson-like eruption, fever of unknown origin, and testicular involvement. All of the patients responded to glucocorticoids; two were also treated with colchicine and one was treated with chlorambucil. In two patients, follow-up of more than 10 years was done, with complete cure in one patient and benign course of illness in the other. Because of the rarity of the disease in childhood and the difficulty in making the diagnosis, there is not enough awareness by pediatricians concerning this disease.

Intraocular pentastomiasis causing unilateral glaucoma

We present a case of intraocular pentastomiasis in a 12-year-old Israel Arab boy. A single secondary pentastomid larva, most likely of Linguatula serrata, was found in the anterior chamber of the right eye, attached loosely to the pupil's border by a fibrinous mass. Associated conditions were iritis, subluxation of the lens, and secondary glaucoma. This is the first documentation of human pentastomiasis in Israel.