GJB2 c.35del variant up-regulates GJA1 gene expression and affects differentiation of human stem cells.

Pathogenic DNA alterations in GJB2 are present in nearly half of non-syndromic hearing loss cases with autosomal recessive inheritance. The most frequent variant in GJB2 causing non-syndromic hearing loss is the frameshifting c.35del. GJB2 encodes Cx26, a protein of the connexin family that assembles hemichannels and gap junctions. The expression of paralogous proteins is believed to compensate for the loss of function of specific connexins. As Cx26 has been involved in cell differentiation in distinct tissues, we employed stem cells derived from human exfoliated deciduous teeth (SHEDs), homozygous for the c.35del variant, to assess GJB2 roles in stem cell differentiation and the relationship between its loss of function and the expression of paralogous genes. Primary SHED cultures from patients and control individuals were compared. SHEDs from patients had significantly less GJB2 mRNA and increased amount of GJA1 (Cx43), but not GJB6 (Cx30) or GJB3 (Cx31) mRNA. In addition, they presented higher induced differentiation to adipocytes and osteocytes but lower chondrocyte differentiation. Our results suggest that GJA1 increased expression may be involved in functional compensation for GJB2 loss of function in human stem cells, and it may explain changes in differentiation properties observed in SHEDs with and without the c.35del variant.

Fmr1 exon 14 skipping in late embryonic development of the rat forebrain.

BACKGROUND: Fragile X syndrome, the major cause of inherited intellectual disability among men, is due to deficiency of the synaptic functional regulator FMR1 protein (FMRP), encoded by the FMRP translational regulator 1 (FMR1) gene. FMR1 alternative splicing produces distinct transcripts that may consequently impact FMRP functional roles. In transcripts without exon 14 the translational reading frame is shifted. For deepening current knowledge of the differential expression of Fmr1 exon 14 along the rat nervous system development, we conducted a descriptive study employing quantitative RT-PCR and BLAST of RNA-Seq datasets. RESULTS: We observed in the rat forebrain progressive decline of total Fmr1 mRNA from E11 to P112 albeit an elevation on P3; and exon-14 skipping in E17-E20 with downregulation of the resulting mRNA. We tested if the reduced detection of messages without exon 14 could be explained by nonsense-mediated mRNA decay (NMD) vulnerability, but knocking down UPF1, a major component of this pathway, did not increase their quantities. Conversely, it significantly decreased FMR1 mRNA having exon 13 joined with either exon 14 or exon 15 site A. CONCLUSIONS: The forebrain in the third embryonic week of the rat development is a period with significant skipping of Fmr1 exon 14. This alternative splicing event chronologically precedes a reduction of total Fmr1 mRNA, suggesting that it may be part of combinatorial mechanisms downregulating the gene's expression in the late embryonic period. The decay of FMR1 mRNA without exon 14 should be mediated by a pathway different from NMD. Finally, we provide evidence of FMR1 mRNA stabilization by UPF1, likely depending on FMRP.

Creatinine-lactate score predicts mortality in non-acetaminophen-induced acute liver failure in patients listed for liver transplantation.

BACKGROUND: The aim of this study was to analyze prognostic indicators of in-hospital mortality among patients listed for urgent liver transplantation (LT) for non-acetaminophen (APAP)-induced acute liver failure (ALF). METHODS: ALF patients listed for LT according to the King's College Criteria were retrospectively reviewed. Variables were recorded from medical records and electronic databases (HCMED and RedCap). RESULTS: The study included 100 patients, of which 69 were subject to LT and 31 died while waiting for LT. Patients were 35.5 ± 14.73 years old, and 78% were females. The main etiologies were virus (17%), drug-induced (32%), autoimmune (15%), and indeterminate hepatitis (31%). The prioritization-to-LT time interval was 1.5 days (0-9). The non-LT patients showed higher lactate (8.71 ± 5.36 vs. 4.48 ± 3.33 mmol/L), creatinine (229 ± 207 vs. 137 ± 136 µm/L), MELD (44 ± 8 vs. 38 ± 8), and BiLE scores (15.8 ± 5.5 vs. 10.3 ± 4.1) compared to LT patients (p < 0.05). Multiple logistic regression analysis identified creatinine and lactate as independent prognostic factors, and a creatinine-lactate (CL) score was developed. ROC analysis showed that creatinine, lactate, MELD, BiLE, and CL scores had considerable specificity (71-88%), but only BiLE, lactate, and CL presented high sensitivities (70%, 80%, and 87% respectively). AUCs were 0.696 for creatinine, 0.763 for lactate, 0.697 for MELD, 0.814 for BiLE, and 0.835 for CL. CONCLUSIONS: CL and BiLE scores predict mortality with more accuracy than MELD in patients with ALF during prioritization time. Creatinine and lactate are independent prognostic factors for mortality.

Liver transplant recipients infected with SARS-CoV-2 in the early postoperative period: Lessons from a single center in the epicenter of the pandemic.

The impact of coronavirus disease-19 (COVID-19) in liver recipients remains largely unknown. Most data derive from small retrospective series of patients transplanted years ago. We aimed to report a single-center case series of five consecutive patients in the early postoperative period of deceased-donor liver transplantation who developed nosocomial COVID-19. Two patients presented important respiratory discomfort and eventually died. One was 69 years old and had severe coronary disease. She rapidly worsened after COVID-19 diagnosis on 9th postoperative day. The other was 67 years old with non-alcoholic steatohepatitis, who experienced prolonged postoperative course, complicated with cytomegalovirus infection and kidney failure. He was diagnosed on 36th postoperative day and remained on mechanical ventilation for 20 days, ultimately succumbing of secondary bacterial infection. The third, fourth, and fifth patients were diagnosed on 10th, 11th, and 18th postoperative day, respectively, and presented satisfactory clinical evolution. These last two patients were severely immunosuppressed, since one underwent steroid bolus for acute cellular rejection and another also used anti-thymocyte globulin for treating steroid-resistant rejection. Our novel experience highlights that COVID-19 may negatively impact the postoperative course, especially in elder and obese patients with comorbidities, and draws attention to COVID-19 nosocomial spread in the early postoperative period.

Livebirth after uterus transplantation from a deceased donor in a recipient with uterine infertility.

BACKGROUND: Uterus transplantation from live donors became a reality to treat infertility following a successful Swedish 2014 series, inspiring uterus transplantation centres and programmes worldwide. However, no case of livebirth via deceased donor uterus has, to our knowledge, been successfully achieved, raising doubts about its feasibility and viability, including whether the womb remains viable after prolonged ischaemia. METHODS: In September, 2016, a 32-year-old woman with congenital uterine absence (Mayer-Rokitansky-Küster-Hauser [MRKH] syndrome) underwent uterine transplantation in Hospital das Clínicas, University of São Paulo, Brazil, from a donor who died of subarachnoid haemorrhage. The donor was 45 years old and had three previous vaginal deliveries. The recipient had one in-vitro fertilisation cycle 4 months before transplant, which yielded eight cryopreserved blastocysts. FINDINGS: The recipient showed satisfactory postoperative recovery and was discharged after 8 days' observation in hospital. Immunosuppression was induced with prednisolone and thymoglobulin and continued via tacrolimus and mycophenalate mofetil (MMF), until 5 months post-transplantation, at which time azathioprine replaced MMF. First menstruation occurred 37 days post-transplantation, and regularly (every 26-32 days) thereafter. Pregnancy occurred after the first single embryo transfer 7 months post-transplantation. No blood flow velocity waveform abnormalities were detected by Doppler ultrasound of uterine arteries, fetal umbilical, or middle cerebral arteries, nor any fetal growth impairments during pregnancy. No rejection episodes occurred after transplantation or during gestation. Caesarean delivery occurred on Dec 15, 2017, near gestational week 36. The female baby weighed 2550 g at birth, appropriate for gestational age, with Apgar scores of 9 at 1 min, 10 at 5 min, and 10 at 10 min, and along with the mother remains healthy and developing normally 7 months post partum. The uterus was removed in the same surgical procedure as the livebirth and immunosuppressive therapy was suspended. INTERPRETATION: We describe, to our knowledge, the first case worldwide of livebirth following uterine transplantation from a deceased donor in a patient with MRKH syndrome. The results establish proof-of-concept for treating uterine infertility by transplantation from a deceased donor, opening a path to healthy pregnancy for all women with uterine factor infertility, without need of living donors or live donor surgery. FUNDING: Fundação de Amparo à Pesquisa do Estado de São Paulo and Hospital das Clínicas, University of São Paulo, Brazil.

Early detection of acute kidney injury in the perioperative period of liver transplant with neutrophil gelatinase-associated lipocalin.

BACKGROUND: Acute kidney injury (AKI) is a common complication in patients undergoing liver transplant (LT) and is associated with high morbidity and mortality. We aim to evaluate the pattern of urine and plasma neutrophil gelatinase-associated lipocalin (NGAL) elevation during the perioperative period of LT and to assess it as a prognostic marker for AKI progression, need for dialysis and mortality. METHODS: We assessed NGAL levels before induction of anesthesia, after portal reperfusion and at 6, 18, 24, and 48 h after surgery. Patients were monitored daily during the first week after LT. RESULTS: Of 100 enrolled patients undergoing liver transplant, 59 developed severe AKI based on the KDIGO serum creatinine (sCr) criterion; 34 were dialysed, and 21 died within 60 days after LT. Applying a cut-off value of 136 ng/ml, UNGAL values 6 h after surgery was a good predictor of AKI development within 7 days after surgery, having a positive predictive value (PPV) of 80% with an AUC of 0.76 (95% CI 0.67-0.86). PNGAL at 18 h after LT was also a good predictor of AKI in the first week, having a PPV of 81% and AUC of 0.74 (95% CI 0.60-0.88). Based on PNGAL and UNGAL cut-off criteria levels, time to AKI diagnosis was 28 and 23 h earlier than by sCr, respectively. The best times to assess the need for dialysis were 18 h after LT by PNGAL and 06 h after LT by UNGAL. CONCLUSION: In conclusion, the plasma and urine NGAL elevation pattern in the perioperative period of the liver transplant can predict AKI diagnosis earlier. UNGAL was an early independent predictor of AKI development and need for dialysis. Further studies are needed to assess whether the clinical use of biomarkers can improve patient outcomes. TRIAL REGISTRATION: Registered at Clinical Trials ( clinicaltrials.gov ) in March 24th, 2014 by title "Acute Kidney Injury Biomarkers: Diagnosis and Application in Pre-operative Period of Liver Transplantation (AKIB)" and identifier NCT02095431, retrospectively registered.

A Cell Junctional Protein Network Associated with Connexin-26.

GJB2 mutations are the leading cause of non-syndromic inherited hearing loss. GJB2 encodes connexin-26 (CX26), which is a connexin (CX) family protein expressed in cochlea, skin, liver, and brain, displaying short cytoplasmic N-termini and C-termini. We searched for CX26 C-terminus binding partners by affinity capture and identified 12 unique proteins associated with cell junctions or cytoskeleton (CGN, DAAM1, FLNB, GAPDH, HOMER2, MAP7, MAPRE2 (EB2), JUP, PTK2B, RAI14, TJP1, and VCL) by using mass spectrometry. We show that, similar to other CX family members, CX26 co-fractionates with TJP1, VCL, and EB2 (EB1 paralogue) as well as the membrane-associated protein ASS1. The adaptor protein CGN (cingulin) co-immuno-precipitates with CX26, ASS1, and TJP1. In addition, CGN co-immunoprecipitation with CX30, CX31, and CX43 indicates that CX association is independent on the CX C-terminus length or sequence. CX26, CGN, FLNB, and DAMM1 were shown to distribute to the organ of Corti and hepatocyte plasma membrane. In the mouse liver, CX26 and TJP1 co-localized at the plasma membrane. In conclusion, CX26 associates with components of other membrane junctions that integrate with the cytoskeleton.

Abdominal wall hernia in cirrhotic patients: emergency surgery results in higher morbidity and mortality.

BACKGROUND: Patients with cirrhosis have a high incidence of abdominal wall hernias and carry an elevated perioperative morbidity and mortality. The optimal surgical management strategy as well as timing of abdominal hernia repair remains controversial. METHODS: A cohort study of 67 cirrhotic patients who underwent hernia repair during the period of January 1998-December 2009 at the University Hospital of Sao Paulo were included. After meeting study criteria, a total of 56 patients who underwent 61 surgeries were included in the final analysis. Patient characteristics, morbidity (Clavien score), mortality, Child-Turcotte-Pugh score, MELD score, use of prosthetic material, and elective or emergency surgery have been analysed with regards to morbidity and 30-day mortality. RESULTS: The median MELD score of the patient population was 14 (range: 6 to 24). Emergency surgery was performed in 34 patients because of ruptured hernia (n = 13), incarceration (n = 10), strangulation (n = 4), and skin necrosis or ulceration (n = 7). Elective surgery was performed in 27 cases. After a multivariable analysis, emergency surgery (OR 7.31; p 0.017) and Child-Pugh C (OR 4.54; p 0.037) were risk factors for major complications. Moreover, emergency surgery was a unique independent risk factor for 30-day mortality (OR 10.83; p 0.028). CONCLUSIONS: Higher morbidity and mortality are associated with emergency surgery in advanced cirrhotic patients. Therefore, using cirrhosis as a contraindication for hernia repair in all patients may be reconsidered in the future, especially after controlling ascites and in those patients with hernias that are becoming symptomatic or show signs of possible skin necrosis and rupture. Future prospective randomized studies are needed to confirm this surgical strategy.

Neuropsychological profile in tuberous sclerosis complex: a study of clinical and cognitive variables in a cohort from Brazil.

BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder with a wide clinical, cognitive, and behavioral expressivity. OBJECTIVE: To assess the neuropsychological profile of individuals clinically diagnosed with TSC and the factors that could significantly impact their cognitive development. METHODS: A total of 62 individuals with ages ranging from 3 to 38 years were followed up in a tertiary attention hospital in Southern Brazil, and they were assessed using a standard battery and the Vineland Adaptive Behavior Scales, when intellectual disability was observed. RESULTS: History of epilepsy was found in 56 participants (90.3%), and 31 (50%) presented an intellectual disability. Among the other half of TSC individuals without intellectual disability, 8 (12.9%) presented borderline classification, 20 (32.2%) presented average scores, and 3 (4.8%) were above average. In total, 17 participants (27.4%) fulfilled the diagnostic criteria for autism spectrum disorder. The results of the multiple linear regression analysis suggested that seizures, age at diagnosis, visual perception, and general attention significantly impact cognitive performance indexes. CONCLUSION: The present study suggests that the occurrence of epileptic seizures and older age at diagnosis contribute to higher impairment in the domains of cognitive development, underlining the importance of early diagnosis and the prevention of epileptic seizures or their rapid control. The development of attentional skills, visual perception, and executive functions must be followed up.

ANTECEDENTES: O complexo da esclerose tuberosa (CET) é uma doença genética autossômica dominante com ampla expressividade clínica, cognitiva e comportamental. OBJETIVO: Avaliar o perfil neuropsicológico de indivíduos com diagnóstico clínico de CET e os fatores que poderiam impactar significativamente o seu desenvolvimento cognitivo. MéTODOS: Ao todo, 62 indivíduos com idades entre 3 e 38 anos foram acompanhados em um hospital terciário do Sul do Brasil e avaliados por meio de uma bateria padrão e das Escalas de Comportamento Adaptativo Vineland, quando observada deficiência intelectual. RESULTADOS: Encontrou-se histórico de epilepsia em 56 participantes (90,3%) e de deficiência intelectual em 31 (50%). Quanto à outra metade dos indivíduos com CET sem deficiência intelectual, 8 (12,9%) apresentaram classificação limítrofe, 20 (32,2%) apresentaram pontuações médias e 3 (4,8%) estavam acima da média. No total, 17 participantes (27,4%) preenchiam os critérios diagnósticos para o transtorno do espectro autista. Os resultados da análise de regressão linear múltipla sugeriram que as crises epilépticas, a idade ao diagnóstico, a percepção visual e a atenção geral impactam significativamente os índices de desempenho cognitivo. CONCLUSãO: Este estudo sugere que a ocorrência de crises epilépticas e a maior idade ao diagnóstico contribuem para um maior comprometimento nos domínios do desenvolvimento cognitivo, e destaca-se a importância do diagnóstico precoce e da prevenção das crises epilépticas ou do seu rápido controle. O desenvolvimento de habilidades de atenção, percepção visual e funções executivas deve ser acompanhado.

A dermatological assessment of pediatric patients with tuberous sclerosis complex (TSC).

BACKGROUND: Tuberous sclerosis complex (TSC) is a multisystem neurocutaneous syndrome with variable phenotypes. Recent updates of TSC diagnostic criteria reaffirmed the defined genetic diagnostic criterion as the finding of a pathogenic DNA alteration in either TSC1 or TSC2 genes. It also slightly modified definite clinical diagnostic criteria. TSC-associated skin lesions in infancy are important clinical signs to select individuals with possible TSC for a closer clinical follow-up and genetic testing. OBJECTIVE: To raise awareness of the updated TSC diagnosis criteria; to assess the frequency of skin lesions in TSC patients as well as the first dermatological presentation; and to associate the findings with either TSC1 or TSC2 mutations. METHODS: Observational cross-sectional study. Clinical and genetic data were retrospectively collected from 37 TSC patients from a Brazilian University Hospital. Patients with skin signs were examined and prospectively assessed for 12 months. RESULTS: The earliest cutaneous lesions were hypomelanotic macules, which together with angiofibromas were the most frequent dermatological lesions. The total pathogenic DNA alteration ratio between TSC2 and TSC1 genes was 8:1. The frequency of a TSC2 pathogenic variant was 10-fold greater in the presence of ungual fibromas. STUDY LIMITATIONS: Small sample and a limited number of patients with TSC1 pathogenic variants. CONCLUSION: Clinicians should be knowledgeable about TSC updated diagnostic criteria. Patients need to be followed up by a multidisciplinary team and treated accordingly. Early detection of cutaneous lesions is important for TSC diagnosis. A significant association between TSC2 gene pathogenic alterations and ungual fibromas is described.

Liver Transplantation for Adenomatosis: A Single-Center Experience.

BACKGROUND: Liver adenomatosis is characterized by multiple adenomas diffusely distributed throughout the liver parenchyma. Studies addressing liver transplantation for those cases are scarce, and the criteria used to indicate transplantation are still debatable. OBJECTIVE: To report a single-center experience of liver transplantation for diffuse adenomatosis. METHODS: Single-center retrospective study involving all adult patients who underwent liver transplantation due to adenomatosis from January/2010 to June/2023. RESULTS: A total of 13 patients were identified, corresponding to 0.89% of liver transplants performed during the study period. The mean age was 33 ± 6.55 years, and most of them were female (n = 9, 69.23%). There were 12 transplants with deceased donors and 1 with a right lobe from a living donor. The most frequent reason to preclude liver resection was multiple and large unresectable adenomas in patients without previous liver disease (n = 8, 61.58%), followed by underlying liver disease (Abernethy Malformation, n = 3, 23.07%) and recurrence after liver resection (n = 2, 15.38%). The indications for liver transplantation were high risk of malignant transformation (n = 7, 53.84%), increasing size and number of nodules (n = 3, 23.07%), confirmed malignant transformation (n = 2, 15.38%), and hemorrhage (n = 2, 15.38%). There was 1 perioperative death due to primary non-function. Another patient died during follow-up because of COVID-19. CONCLUSION: Liver adenomatosis is a rare indication for liver transplantation, with acceptable post-transplant outcomes. Unresectable adenomas with high-risk or confirmed malignant transformation are the main indications for transplant. Reasons for unresectability involve underlying liver disease, multiple and large high-risk nodules, and recurrence after previous resection.

Clinical Characterization and Underlying Genetic Findings in Brazilian Patients with Syndromic Microcephaly Associated with Neurodevelopmental Disorders.

Microcephaly is characterized by an occipitofrontal circumference at least two standard deviations below the mean for age and sex. Neurodevelopmental disorders (NDD) are commonly associated with microcephaly, due to perturbations in brain development and functioning. Given the extensive genetic heterogeneity of microcephaly, managing patients is hindered by the broad spectrum of diagnostic possibilities that exist before conducting molecular testing. We investigated the genetic basis of syndromic microcephaly accompanied by NDD in a Brazilian cohort of 45 individuals and characterized associated clinical features, as well as evaluated the effectiveness of whole-exome sequencing (WES) as a diagnostic tool for this condition. Patients previously negative for pathogenic copy number variants underwent WES, which was performed using a trio approach for isolated index cases (n = 31), only the index in isolated cases with parental consanguinity (n = 8) or affected siblings in familial cases (n = 3). Pathogenic/likely pathogenic variants were identified in 19 families (18 genes) with a diagnostic yield of approximately 45%. Nearly 86% of the individuals had global developmental delay/intellectual disability and 51% presented with behavioral disturbances. Additional frequent clinical features included facial dysmorphisms (80%), brain malformations (67%), musculoskeletal (71%) or cardiovascular (47%) defects, and short stature (54%). Our findings unraveled the underlying genetic basis of microcephaly in half of the patients, demonstrating a high diagnostic yield of WES for microcephaly and reinforcing its genetic heterogeneity. We expanded the phenotypic spectrum associated with the condition and identified a potentially novel gene (CCDC17) for congenital microcephaly.

Liver Transplantation for Benign Massive Hepatomegaly: Results From a Single Center and Contribution of the Left-to-Right Piggyback Approach.

INTRODUCTION: Polycystic liver disease and giant hepatic hemangioma may present with severe symptom burden and indicate orthotopic liver transplantation. The left-to-right piggyback approach is a useful technique for performing total hepatectomy of enlarged livers. OBJECTIVE: The purpose of this study is to analyze the results of liver transplantation in patients with benign massive hepatomegaly. METHODS: This is a single-center retrospective study involving all adult patients who underwent liver transplantation due to benign massive hepatomegaly from January 2002 to June 2023. RESULTS: A total of 22 patients underwent liver transplantation (21 cases of polycystic live disease and 1 case of giant hepatic hemangioma). During the same time, there were 2075 transplants; therefore, benign massive hepatomegaly accounted for 1.06% of cases. Most patients (59.09%) were transplanted using the left-to-right piggyback technique. Seven patients had previous attempted treatment of hepatic cysts. Another patient previously underwent bilateral nephrectomy and living-donor kidney transplantation. Among these patients, in 5 cases there were massive abdominal adhesions with increased bleeding. Four of these 8 patients died in the very early perioperative period. In comparison to patients without previous cysts manipulation, massive adhesions and perioperative death were significantly higher in those cases (62.5 vs 0%, P = .002 and 50% vs 0%, P = .004, respectively). CONCLUSION: Liver transplantation due to polycystic liver disease and giant hemangioma is a rare event. Total hepatectomy is challenging due to the enlarged native liver. The left-to-right piggyback technique is useful, because it avoids vena cava twisting and avulsion of its branches. Massive adhesions due to previous cysts manipulation may lead to increased bleeding, being a risk factor for mortality.

Retransplantation for Late Hepatic Artery Thrombosis: Results from a Single Center.

BACKGROUND: Hepatic artery thrombosis is the most common vascular complication of liver transplantation. When occurring late in the postoperative course, it may have no clinical repercussions, and conservative treatment may be implemented. Some patients, however, will develop severe biliary complications due to ischemic cholangiopathy and require retransplantation. The aim of this study is to report the outcomes of retransplantation in this population. METHODS: This is a single-center retrospective study involving all adult patients who underwent liver retransplantation due to late hepatic artery thrombosis from January/2010 to December/2022. RESULTS: During the study period, 1378 liver transplants were performed in our center; 147 were retransplantations, with 13 cases of late hepatic artery thrombosis (0.94%). All had symptomatic ischemic cholangiopathy. Twelve of them had already presented previous cholangitis, bilomas, or liver abscesses and had undergone biliary stenting or percutaneous drainage. The median time between the first liver transplant and late hepatic artery thrombosis diagnosis and between this diagnosis and retransplantation were 73 and 50 days, respectively. Arterial reconstruction using splenic artery, celiac trunk, or arterial conduit from the aorta was performed in 7 cases, whereas biliary reconstruction was mostly done with choledochojejunostomy (n = 8). There were 4 perioperative deaths, 2 due to primary non-function and 2 due to refractory shock after exceedingly complex retransplants. CONCLUSION: Liver retransplantation due to late hepatic artery thrombosis is a rare condition that should be offered to patients who develop severe biliary complications and recurrent infections. It is nonetheless a challenging procedure associated with significant perioperative mortality.

Bone marrow stem cells in facial nerve regeneration from isolated stumps.

INTRODUCTION: Severe lesions in the facial nerve may have extensive axonal loss and leave isolated stumps that impose technical difficulties for nerve grafting. METHODS: We evaluated bone marrow stem cells (BMSC) in a silicone conduit for rat facial nerve regeneration from isolated stumps. Group A utilized empty silicone tubes; in groups B-D, the tube was filled with acellular gel; and, in groups C and D, undifferentiated BMSC (uBMSC) or Schwann-like cells differentiated from BMSC (dBMSC) were added, respectively. Compound muscle action potentials (CMAPs) were measured, and histology was evaluated. RESULTS: Groups C and D had the highest CMAP amplitudes. Group C had shorter CMAP durations than groups A, B, and D. Distal axonal number and density were increased in group C compared with groups A and B. CONCLUSIONS: Regeneration of the facial nerve was improved by both uBMSC and dBMSC in rats, yet uBMSC was associated with superior functional results.

Understanding the Elevated Lethality of COVID-19 in Liver Transplant Recipients: Does Immunosuppression Management Matter? Results from a Brazilian Multicentric Historical Cohort.

BACKGROUND: Infections by SARS-CoV-2 in liver transplant recipients (LT) patients are of particular concern, notably due to perceived added risks related to immunosuppression and comorbidity burden. Current literature on this topic often relies on small, non-standardized, and geographically limited studies. This manuscript describes COVID-19 presentations and causes for elevated mortality in a large cohort of LT recipients. METHODS: This study was designed as a multicentric historical cohort, including LT recipient patients with COVID-19 in 25 study centers, with the primary endpoint being COVID-related death. We also collected demographic, clinical, and laboratory data regarding presentation and disease progression. RESULTS: Two hundred and thirty-four cases were included. The study population was predominantly male and White and had a median age of 60 years. The median time from transplantation was 2.6 years (IQR 1-6). Most patients had at least one comorbidity (189, 80.8%). Patient age (P = .04), dyspnea (P < .001), intensive care unit admission (P < .001), and mechanical ventilation (P < .001) were associated with increased mortality. Modifications of immunosuppressive therapy (P < .001), specifically the suspension of tacrolimus, maintained significance in multivariable analysis. CONCLUSIONS: Attention to risk factors and the individualization of patient care, especially regarding immunosuppression management, is crucial for delivering more precise interventions to these individuals.