Revision Carpal Tunnel Release Following Endoscopic Compared With Open Decompression.

Importance: Carpal tunnel release (CTR) technique may influence the likelihood of revision surgery. Prior studies of revision CTR following endoscopic CTR (ECTR) compared with open CTR (OCTR) have been limited by sample size and duration of follow-up. Objective: To estimate the incidence of revision CTR following ECTR compared with OCTR in a national cohort. Design, Setting, and Participants: This retrospective cohort study used data from the US Veterans Health Administration. Participants included all adults (age ≥18 years) undergoing at least 1 outpatient CTR from October 1, 1999, to May 20, 2021. Data were analyzed from May 21, 2021, to November 27, 2023. Exposure: Index CTR technique. Main Outcomes and Measures: The primary outcome was time to revision CTR, defined as repeat ipsilateral CTR during the study period. Secondary outcomes were indications for revision, findings during revision, and additional procedures performed during revision. Results: Among 134 851 wrists from 103 455 patients (92 510 [89.4%] male; median [IQR] age, 62 [53-70] years) undergoing at least 1 CTR, 1809 wrists underwent at least 1 revision at a median (IQR) of 2.5 (1.0-3.8) years. In competing-risks analysis, the cumulative incidence of revision was 1.06% (95% CI, 0.99%-1.12%) at 5 years and 1.59% (95% CI, 1.51%-1.67%) at 10 years. ECTR was associated with increased hazard of revision CTR compared with OCTR (adjusted hazard ratio [aHR], 1.56; 95% CI, 1.34-1.81; P < .001). The risk difference for revision CTR associated with ECTR compared with OCTR was 0.57% (95% CI, 0.31%-0.84%) at 5 years (number needed to harm, 176) and 0.72% (95% CI, 0.36%-1.07%) at 10 years (number needed to harm, 139). Regardless of index CTR technique, the most common indication for revision was symptom recurrence (1062 wrists [58.7%]). A reconstituted transverse carpal ligament (TCL) was more common after ECTR compared with OCTR, whereas scarring of the overlying tissues and of the median nerve itself were more common following OCTR. Incomplete transverse-carpal-ligament release was observed in 251 of the wrists undergoing revision CTR (13.94%) and was more common among revisions following ECTR (odds ratio, 1.62; 95% CI, 1.11-2.37; P = .01). Conclusions and Relevance: In this cohort study of revision CTR in the Veterans Health Administration, ECTR was associated with increased risk of revision compared with OCTR, but the absolute risk was low regardless of technique. Intraoperative findings at revision varied significantly according to index CTR technique.

Diagnosing Systemic Amyloidosis Presenting as Carpal Tunnel Syndrome: A Risk Nomogram to Guide Biopsy at Time of Carpal Tunnel Release.

BACKGROUND: As carpal tunnel syndrome often precedes other signs of systemic amyloidosis, tenosynovial biopsy at the time of carpal tunnel release may facilitate early diagnosis and treatment. However, evidence-based guidelines for amyloidosis screening during carpal tunnel release have not been established. We sought to develop a predictive model for amyloidosis after carpal tunnel release to inform screening efforts. METHODS: We performed a retrospective cohort study of adults without known amyloidosis undergoing at least 1 carpal tunnel release from 2000 to 2019 with use of the national Veterans Health Administration database. After estimating the cumulative incidence of amyloidosis after carpal tunnel release, we identified risk factors, constructed a predictive nomogram based on a multivariable subdistribution-hazard competing-risks model, and performed cross-validation. RESULTS: Among 89,981 patients undergoing at least 1 carpal tunnel release, 310 were subsequently diagnosed with amyloidosis at a median interval of 4.5 years, corresponding to a cumulative incidence of 0.55% (95% confidence interval [CI]: 0.47% to 0.63%) at 10 years. Amyloidosis diagnosis following carpal tunnel release was associated with an increased hazard of heart failure (hazard ratio [HR], 4.68; 95% CI: 4.26 to 5.55) and death (HR, 1.27; 95% CI: 1.07 to 1.51) after adjustment for potential confounders. Age, male sex, Black race, monoclonal gammopathy of undetermined significance or multiple myeloma, rheumatoid arthritis, atrial fibrillation, spinal stenosis, and bilateral carpal tunnel syndrome were independently associated with increased risk of amyloidosis diagnosis and were included in the risk nomogram. CONCLUSIONS: Amyloidosis diagnosis after carpal tunnel release is rare but is associated with poor outcomes. We present an amyloidosis-risk nomogram to help guide tenosynovial biopsy at time of carpal tunnel release. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Robust intrinsic differences in mitochondrial respiration and H2O2 emission between L6 and C2C12 cells.

Rat L6 and mouse C2C12 cell lines are commonly used to investigate myocellular metabolism. Mitochondrial characteristics of these cell lines remain poorly understood despite mitochondria being implicated in the development of various metabolic diseases. To address this need, we performed high-resolution respirometry to determine rates of oxygen consumption and H2O2 emission in suspended myoblasts during multiple substrate-uncoupler-inhibitor titration protocols. The capacity for oxidative phosphorylation supported by glutamate and malate, with and without succinate, or supported by palmitoyl-l-carnitine was lower in L6 compared with C2C12 myoblasts (all P < 0.01 for L6 vs. C2C12). Conversely, H2O2 emission during oxidative phosphorylation was greater in L6 than C2C12 myoblasts (P < 0.01 for L6 vs. C2C12). Induction of noncoupled respiration revealed a significantly greater electron transfer capacity in C2C12 compared with L6 myoblasts, regardless of the substrate(s) provided. Mitochondrial metabolism was also investigated in differentiated L6 and C2C12 myotubes. Basal rates of oxygen consumption were not different between intact, adherent L6, and C2C12 myotubes; however, noncoupled respiration was significantly lower in L6 compared with C2C12 myotubes (P = 0.01). In summary, L6 myoblasts had lower respiration rates than C2C12 myoblasts, including lesser capacity for fatty acid oxidation and greater electron leak toward H2O2. L6 cells also retain a lower capacity for electron transfer compared with C2C12 following differentiation to form fused myotubes. Intrinsic differences in mitochondrial metabolism between these cell lines should be considered when modeling and investigating myocellular metabolism.

Neurite Growth and Polarization on Vitronectin Substrate after in Vitro Trauma is not Enhanced after IGF Treatment.

Following traumatic brain injuries (TBI), insulin-like growth factor (IGF) is cortically widely upregulated. This upregulation has a potential role in the recovery of neuronal tissue, plasticity, and neurotrophic activity, though the molecular mechanisms involved in IGF regulation and the exact role of IGF after TBI remain unclear. Vitronectin (VN), an extracellular matrix (ECM) molecule, has recently been shown to be of importance for IGF-mediated cellular growth and migration. Since VN is downregulated after TBI, we hypothesized that insufficient VN levels after TBI impairs the potential beneficial activity of IGF. To test if vitronectin and IGF-1/IGFBP-2 could contribute to neurite growth, we cultured hippocampal neurons on ± vitronectin-coated coverslips and them treated with ± IGF-1/IGF binding protein 2 (IGFBP-2). Under same conditions, cell cultures were also subjected to in vitro trauma to investigate differences in the posttraumatic regenerative capacity with ± vitronectin-coated coverslips and with ± IGF-1/IGFBP-2 treatment. In both the control and trauma situations, hippocampal neurons showed a stronger growth pattern on vitronectin than on the control substrate. Surprisingly, the addition of IGF-1/IGFBP-2 showed a decrease in neurite growth. Since neurite growth was measured as the number of neurites per area, we hypothesized that IGF-1/IGFBP-2 contributes to the polarization of neurons and thus induced a less dense neurite network after IGF-1/IGFBP-2 treatment. This hypothesis could not be confirmed and we therefore conclude that vitronectin has a positive effect on neurite growth in vitro both under normal conditions and after trauma, but that addition of IGF-1/IGFBP-2 does not have a positive additive effect.

[Expanded ambulatory physiotherapy (EAP) and ambulatory orthopedic trauma rehabilitation (AOTR)]. / Erweiterte ambulante Physiotherapie (EAP) und ambulante orthopädische traumatologische Rehabilitation (AOTR).

Orthopaedic rehabilitation for outpatients in Germany called EAP/AOTR is a new and complex therapy which combines elements of physical therapy and orthopaedic rehabilitation that so far have only been applied separately. This sophisticated therapy is based on individually made up plan of treatment, supervised by a specialist. Its aim is to substitute/shorten inpatient treatment and inability to work. Indications are strictly stipulated and differ among the various health insurance companies and state pension authorities. Undue increase in indication, in duration of treatment and thus in cost led to criticism by the above mentioned institutions. This effective treatment will eventually hold an eminent place in medical care if proper attention is paid to efficient control, adherence to basic agreement and requirements, scientific research and evaluation, as well as to increase consultation of specialists, qualified in physical rehabilitation. To renounce outpatient treatment as an alternative to inpatient treatment is unreasonable from a medical point of view and is quite impossible with regard to cost.

The mechanism of specific prolongation of class I-mismatched skin grafts induced by retroviral gene therapy.

In the present study, we examine the mechanism of specific hyporesponsiveness to major histocompatibility complex (MHC) class I-mismatched skin allografts induced by retrovirus-mediated gene transfer of an allogeneic class I gene into syngeneic bone marrow (BM). Using appropriate congenic recombinant mouse strains, we have mapped MHC determinants that are capable of restoring rapid rejection of Kb-bearing skin grafts. Our results indicate that either a single class I or a single class II alloantigen expressed on skin in association with Kb is able to restore the rapid rejection of Kb-mismatched skin grafts. These data suggest that third-party alloantigens expressed on skin in association with Kb abrogate hyporesponsiveness by providing T cell help. Consistent with this interpretation, spleen cells from mice reconstituted with Kb-transduced BM were unable to elicit a significant anti-Kb cytotoxic T lymphocyte response in vitro unless interleukin-2 was added to the culture medium. Skin graft survival was also analyzed on B10. AKM mice thymectomized 3-4 weeks post-reconstitution with Kb-transduced BM. Thymectomy did not result in significantly prolonged survival of B10. MBR skin grafts compared to euthymic controls, suggesting that even early after reconstitution, intrathymic deletion of Kb-reactive T cells must have been incomplete. Taken together, these data suggest that prolongation of skin allograft survival in this model is controlled at the level of T cell help.

Pig to monkey bone marrow and kidney xenotransplantation.

BACKGROUND: The intensity of discordant xenograft cellular rejection makes it unlikely that safe doses of immunosuppressive drugs will alone be sufficient to permit long-term survival. We have therefore concentrated our efforts on establishing tolerance to xenogeneic organs through lymphohematopoietic chimerism and the elimination of preformed natural antibodies (nAbs). METHODS: Here we report the most recent series of 11 technically successful porcine to nonhuman primate transplantation procedures. In eight experimental animals induction therapy consisted of (1) 3 x 100 cGy nonlethal whole body irradiation (day -6 and day -5) to all animals, (2) horse anti-human thymocyte globulin (day -2, day -1, and day 0) to seven of the animals, (3) 700 cGy thymic irradiation (day -1) to five of the animals, and (4) pig bone marrow infused on day 0 (2-9 x 10(8)/cells/kg). On day 0, just before the renal xenograft, the recipient was splenectomized, and antipig nAbs were removed by means of perfusion of the monkey's blood through either a pig liver (n = 6) or a Gal-alpha (1,3)-Gal adsorption column (n = 5). There control animals did not receive this pretransplantation induction therapy but did undergo hemoperfusion and posttransplantation immunosuppression identical to the experimental animals. All 11 recipients were treated after transplantation with cyclosporin A and 15-deoxyspergualin. Recombinant pig-specific growth factors (interleukin-3 and stem cell factor) were given to six experimental animals from day 0 until the termination of the experiment. RESULTS: Analysis of recipients' sera by means of flow cytometry indicated the effective removal of immunoglobulin M and immunoglobulin G nAbs by either liver perfusion or column adsorption. In the eight experimental animals, nAb titers remained low until death (up to 15 days), but in the three control animals nAb titers increased substantially with time. The longest surviving recipient maintained excellent kidney function with creatinine levels at 0.8 to 1.3 mg/dl throughout its course. Death occurred at day 15 from complications caused by a urinary leak and pancytopenia. Histologic examination of the xenograft revealed only focal tubular necrosis and cytoplasmic vacuolization, with trace amounts of fibrin and C3 in peritubular capillaries. In this animal a fraction of the peripheral blood cells (3%) at day 7 were of pig origin as detected by pig-specific monoclonal antibodies. In addition, colony-forming assays performed on a bone marrow biopsy specimen taken at day 14 indicated that approximately 30% of the relatively few myeloid progenitors detected were of swine origin. CONCLUSIONS: We have demonstrated that our protocol is effective in the prevention of hyperacute rejection and in the maintenance of excellent function of the renal xenograft for up to 15 days. These results also indicate that at least short-term engraftment of the xenogeneic donor bone marrow cells is possible to achieve in this discordant large animal combination. Longer survivals will be required to assess the possible effect of this engraftment on induction of tolerance.

The neuropharmacology of various diazepam antagonists.

Recently, compounds which bind avidly to benzodiazepine binding sites have been shown to possess diazepam antagonist properties. For example, the benzodiazepine RO 15-1788 and the pyrazoloquinoline CGS 8216 can antagonize the anxiolytic, sedative, muscle relaxant and anticonvulsant properties of diazepam. The beta-carbolines have also been shown to antagonize several actions of diazepam. Other compounds including physostigmine, naloxone, bicuculline, picrotoxin, caffeine and theophylline, lack appreciable affinity for benzodiazepine binding sites but do antagonize at least some of the behavioral actions of diazepam. Their antagonist properties are probably the result of opposing pharmacological actions rather than direct receptor antagonism. Clinically, a potent safe diazepam antagonist could be used to reverse effects of diazepam overdose and to speed recovery of diazepam-treated patients after various out-patient procedures.