Performance of a targeted cell-free DNA prenatal test for 22q11.2 deletion in a large clinical cohort.

OBJECTIVE: 22q11.2 deletion is more common than trisomies 18 and 13 combined, yet no routine approach to prenatal screening for this microdeletion has been established. This study evaluated the clinical sensitivity and specificity of a targeted cell-free DNA (cfDNA) test to screen for fetal 22q11.2 deletion in a large cohort, using blinded analysis of prospectively enrolled pregnancies and stored clinical samples. METHODS: In order to ensure that the analysis included a meaningful number of cases with fetal 22q11.2 deletion, maternal plasma samples were obtained by prospective, multicenter enrolment of pregnancies with a fetal cardiac abnormality and from stored clinical samples from a research sample bank. Fetal genetic status, as evaluated by microarray analysis, karyotyping with fluorescence in-situ hybridization or a comparable test, was available for all cases. Samples were processed as described previously for the Harmony prenatal test, with the addition of DANSR (Digital Analysis of Selected Regions) assays targeting the 3.0-Mb region of 22q11.2 associated with 22q11.2 deletion syndrome. Operators were blinded to fetal genetic status. Sensitivity and specificity of the cfDNA test for 22q11.2 deletion were calculated based on concordance between the cfDNA result and fetal genotype. RESULTS: The final study group consisted of 735 clinical samples, including 358 from prospectively enrolled pregnancies and 377 stored clinical samples. Of 46 maternal plasma samples from pregnancies with a 22q11.2 deletion, ranging in size from 1.25 to 3.25 Mb, 32 had a cfDNA result indicating a high probability of 22q11.2 deletion (sensitivity, 69.6% (95% CI, 55.2-80.9%)). All 689 maternal plasma samples without a 22q11.2 deletion were classified correctly by the cfDNA test as having no evidence of a 22q11.2 deletion (specificity, 100% (95% CI, 99.5-100%)). CONCLUSIONS: The results of this large-scale prospective clinical evaluation of the sensitivity and specificity of a targeted cfDNA test for fetal 22q11.2 deletion demonstrate that this test can detect the common and smaller, nested 22q11.2 deletions with a low (0-0.5%) false-positive rate. Although the positive predictive value (PPV) observed in this study population was 100%, the expected PPV in the general pregnant population is estimated to be 12.2% at 99.5% specificity and 41.1% at 99.9% specificity. The use of this cfDNA test to screen for 22q11.2 deletion could enhance identification of pregnancies at risk for 22q11.2 deletion syndrome without significantly increasing the likelihood of maternal anxiety and unnecessary invasive procedures related to a false-positive result. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Systematic review of the introduction and evaluation of magnetic augmentation of the lower oesophageal sphincter for gastro-oesophageal reflux disease.

BACKGROUND: Magnetic sphincter augmentation (MSA) is reported to be an innovative alternative to antireflux surgery for patients with gastro-oesophageal reflux disease. Although used in practice, little is known about how it has been evaluated. This study aimed to systematically summarize and appraise the reporting of MSA and its introduction into clinical practice, in the context of guidelines (such as IDEAL) for evaluating innovative surgical devices. METHODS: Systematic searches were used to identify all published studies reporting MSA insertion. Data collected included patient selection, governance arrangements, surgeon expertise, technique description and outcome reporting. RESULTS: Searches identified 587 abstracts; 39 full-text papers were included (1 RCT 5 cohort, 3 case-control, 25 case series, 5 case reports). Twenty-one followed US Food and Drug Administration eligibility criteria for MSA insertion. Twenty-six documented that ethical approval was obtained. Two reported that participating surgeons received training in MSA; 18 provided information about how MSA insertion was performed, although techniques varied between studies. Follow-up ranged from 4 weeks to 5 years; in 14 studies, it was less than 1 year. CONCLUSION: Most studies on MSA lacked information about patient selection, governance, expertise, techniques and outcomes, or varied between studies. Currently, MSA is being used despite a lack of robust evidence for its effectiveness.

ANTECEDENTES: El aumento de esfínter con un dispositivo magnético (magnetic sphincter augmentation, MSA) se ha descrito como una alternativa innovadora a la cirugía antirreflujo para pacientes con enfermedad por reflujo gastroesofágico. Aunque este procedimiento se utiliza en la práctica, se sabe poco acerca de cómo ha sido evaluado. Este estudio se propuso resumir sistemáticamente y evaluar los trabajos sobre MSA y su introducción en la práctica clínica, en el contexto de las guías (como IDEAL) para la evaluación de dispositivos quirúrgicos innovadores. MÉTODOS: Se identificaron todos los estudios publicados que describían la colocación de MSA efectuando búsquedas sistemáticas. Los datos recogidos incluían la selección de los pacientes, disposiciones de gobernanza, experiencia del cirujano, descripción técnica, y descripción de resultados. RESULTADOS: Las búsquedas identificaron 587 resúmenes, incluyéndose 39 artículos completos (5 estudios de cohortes, 3 estudios de casos y controles, 26 series de casos, 5 casos clínicos). En 21 estudios se siguieron los criterios de elegibilidad de la FDA para la colocación de MSA. En 26 estudios se confirmaba que se había obtenido la aprobación ética. Dos estudios describieron que los cirujanos participantes habían recibido formación en MSA; 18 proporcionaron información sobre cómo se realizó la colocación de MSA, aunque las técnicas variaron entre los estudios. El seguimiento oscilaba entre 4 semanas y 5 años; en 14 estudios fue inferior a un año. CONCLUSIÓN: La mayoría de los estudios sobre MSA fueron casos aislados y series de casos, sin un incremento apreciable en la calidad de la evidencia sobre MSA. La información sobre la selección de los pacientes, gobernanza, experiencia, técnicas, y resultados estaba ausente o variaba entre los estudios, haciendo difíciles las comparaciones. En la actualidad, MSA se utiliza a pesar de la falta de evidencia robusta sobre su efectividad.

Impact of peripheral immune status on central molecular responses to facial nerve axotomy.

When facial nerve axotomy (FNA) is performed on immunodeficient recombinase activating gene-2 knockout (RAG-2-/-) mice, there is greater facial motoneuron (FMN) death relative to wild type (WT) mice. Reconstituting RAG-2-/- mice with whole splenocytes rescues FMN survival after FNA, and CD4+ T cells specifically drive immune-mediated neuroprotection. Evidence suggests that immunodysregulation may contribute to motoneuron death in amyotrophic lateral sclerosis (ALS). Immunoreconstitution of RAG-2-/- mice with lymphocytes from the mutant superoxide dismutase (mSOD1) mouse model of ALS revealed that the mSOD1 whole splenocyte environment suppresses mSOD1 CD4+ T cell-mediated neuroprotection after FNA. The objective of the current study was to characterize the effect of CD4+ T cells on the central molecular response to FNA and then identify if mSOD1 whole splenocytes blocked these regulatory pathways. Gene expression profiles of the axotomized facial motor nucleus were assessed from RAG-2-/- mice immunoreconstituted with either CD4+ T cells or whole splenocytes from WT or mSOD1 donors. The findings indicate that immunodeficient mice have suppressed glial activation after axotomy, and cell transfer of WT CD4+ T cells rescues microenvironment responses. Additionally, mSOD1 whole splenocyte recipients exhibit an increased astrocyte activation response to FNA. In RAG-2-/- + mSOD1 whole splenocyte mice, an elevation of motoneuron-specific Fas cell death pathways is also observed. Altogether, these findings suggest that mSOD1 whole splenocytes do not suppress mSOD1 CD4+ T cell regulation of the microenvironment, and instead, mSOD1 whole splenocytes may promote motoneuron death by either promoting a neurotoxic astrocyte phenotype or inducing Fas-mediated cell death pathways. This study demonstrates that peripheral immune status significantly affects central responses to nerve injury. Future studies will elucidate the mechanisms by which mSOD1 whole splenocytes promote cell death and if inhibiting this mechanism can preserve motoneuron survival in injury and disease.

Can daytime measures of lung function predict respiratory failure in children with neuromuscular disease?

Neuromuscular disorders in children are a heterogeneous group of conditions with a variable age of presentation and overlapping clinical manifestations, many of which have progressive respiratory morbidity. Respiratory insufficiency occurs as a consequence of an imbalance between demands on the respiratory system and respiratory muscle capacity. Daytime measures of pulmonary function are used routinely in these children to assess respiratory status and monitor the consequences of the progression of muscle weakness. This review describes the current evidence for daytime pulmonary function tests and their ability to predict imminent respiratory morbidity.

Lower extremity amputations--a review of global variability in incidence.

AIM: To quantify global variation in the incidence of lower extremity amputations in light of the rising prevalence of diabetes mellitus. METHODS: An electronic search was performed using the EMBASE and MEDLINE databases from 1989 until 2010 for incidence of lower extremity amputation. The literature review conformed to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards. RESULTS: Incidence of all forms of lower extremity amputation ranges from 46.1 to 9600 per 10(5) in the population with diabetes compared with 5.8-31 per 10(5) in the total population. Major amputation ranges from 5.6 to 600 per 10(5) in the population with diabetes and from 3.6 to 68.4 per 10(5) in the total population. Significant reductions in incidence of lower extremity amputation have been shown in specific at-risk populations after the introduction of specialist diabetic foot clinics. CONCLUSION: Significant global variation exists in the incidence of lower extremity amputation. Ethnicity and social deprivation play a significant role but it is the role of diabetes and its complications that is most profound. Lower extremity amputation reporting methods demonstrate significant variation with no single standard upon which to benchmark care. Effective standardized reporting methods of major, minor and at-risk populations are needed in order to quantify and monitor the growing multidisciplinary team effect on lower extremity amputation rates globally.

Exogenous androgen treatment delays the stress response following hamster facial nerve injury.

Following injury or stress of any type, cells undergo a stress response, involving the cessation of general protein synthesis and the up-regulation of heat shock proteins (HSP), which have been implicated in promoting cell survival and repair. In a variety of neuronal injury models, including the hamster facial motoneurone (FMN) model, steroid hormones augment regeneration and are neuroprotective. We have previously shown that facial nerve axotomy induces expression of HSP70 (HSP70) and/or up-regulates constitutively expressed HSP70 (HSC70) mRNA in axotomised hamster FMN and that testosterone propionate (TP) treatment reduces this response. These previous studies were unable to differentiate between HSC70 mRNA and HSP70 mRNA. Therefore, an objective of the present study was to determine which HSP (HSC70 or HSP70) was being up-regulated by axotomy and reduced by TP. Axotomy increased HSC70 protein in axotomised and non-axotomised FMN, relative to untreated baseline hamsters. Interestingly, TP transiently delayed the stress-induced up-regulation of HSC70 protein in axotomised FMN compared to axotomised FMN from non-TP treated controls. A potential explanation for this delay may involve the TP-induced liberation of HSP from the androgen receptor, which would provide the injured cell with an immediately available pool of protective HSP. An hypothesis is presented suggesting that this TP-induced delay of stress-induced HSC70 up-regulation might allow for the diversion of cellular energy away from HSP synthesis and towards the synthesis of proteins required for regeneration and survival.

Enhanced hydrolysis of carbohydrates in primary sludge under biosulfidogenic conditions.

The potential for using readily available and cost-effective complex carbon sources, such as primary sludge (PS), for the bioremediation of sulfate-rich effluent streams, including acid mine drainage, has been constrained by the slow rate of solubilization and low yield of soluble products. Disposal of PS also remains a global problem. Recent studies of a patented recycling sludge bed reactor have shown that the solubilization of PS is enhanced under biosulfidogenic conditions. The current study investigated the enhanced solubilization of the carbohydrate fraction of PS under these conditions, using selective metabolic inhibitors. The mean maximum rate of reducing sugar production was significantly higher under sulfidogenic (167 mg L(-1)h(-1)) than methanogenic (51 mg L(-1)h(-1)) conditions and the utilization of volatile fatty acids under sulfidogenic conditions was rapid. Analysis of VFA profiles indicated preferential utilization of longer chain acids under sulfidogenic conditions and of acetate in the methanogenic systems and that the acetogenic step was unlikely to be rate-limiting in the solubilization of complex carbon.

Deficiency of the syntrophins and alpha-dystrobrevin in patients with inherited myopathy.

The syntrophins and dystrobrevins are members of the dystrophin-associated protein complex, and are thought to function as modular adaptors for signalling proteins recruited to the sarcolemmal membrane. We have characterised the expression of the syntrophins (alpha-, beta1-, and beta2-) and alpha-dystrobrevin by immunohistochemistry in normal human muscle and in biopsies from 162 patients with myopathies of unknown aetiology (with normal staining for dystrophin and other dystrophin-associated proteins). Unlike mice, beta2-syntrophin is expressed at the sarcolemma in post-natal human skeletal muscle. Deficiency of alpha-dystrobrevin +/- beta2-syntrophin was present in 16/162 (10%) patients, compared to age-matched controls. All patients presented with congenital-onset hypotonia and weakness, although there was variability in clinical severity. Two major clinical patterns emerged: patients with deficiency of beta2-syntrophin and alpha-dystrobrevin presented with severe congenital weakness and died in the first year of life, and two patients with deficiency of alpha-dystrobrevin had congenital muscular dystrophy with complete external ophthalmoplegia. We have sequenced the coding regions of alpha-dystrobrevin and beta2-syntrophin in these patients, and identified a new isoform of dystrobrevin, but have not identified any mutations. This suggests that disease causing mutations occur outside the coding region of these genes, in gene(s) encoding other components of the syntrophin-dystrobrevin subcomplex, or in gene(s) responsible for their post-translational modification and normal localisation.

Primary gamma-sarcoglycanopathy (LGMD 2C): broadening of the mutational spectrum guided by the immunohistochemical profile.

An important step in the diagnostic evaluation of a patient with recessive limb-girdle muscular dystrophy is the immunohistochemical analysis of the components of the sarcoglycan complex in a muscle biopsy specimen. Even though a primary mutation in any of the four sarcoglycan genes (alpha-, beta-,gamma-, delta-sarcoglycan) may cause secondary deficiencies in all the other sarcoglycan proteins, more specific immunohistochemical patterns have emerged with the potential to guide and abbreviate the necessary molecular genetic investigations. In gamma-sarcoglycan mutations, the pattern consists of absent or prominently reduced gamma-sarcoglycan immunoreactivity in combination with reduced but detectable immunoreactivity for the other components, with preservation of delta-sarcoglycan. In five consecutive patients, this pattern was able to predict primary gamma-sarcoglycan mutations. Five different mutations were found, including a recurrent novel splice mutation, a large deletion of the entire gene and a novel missense mutation (Leu90Ser). The mutation Cys283Tyr, previously restricted to Gypsy populations was found in compound heterozygosity with del521T, common in north Africa. The variety of known and novel mutations found indicates that the immunohistochemical profile of gamma-sarcoglycan mutations is not restricted to a particular mutation or type of mutation, but rather is a general reflection of the effect of gamma-sarcoglycan mutations on the composition of the sarcoglycan complex. Complete immunohistochemical analysis with all available sarcoglycan antibodies, therefore, is a useful tool to guide the molecular genetic investigations that are necessary to arrive at the correct genetic diagnosis in a given case.

Neuroprotective effects of gonadal steroids on regenerating peripheral motoneurons.

In this review, the neuroprotective actions of testosterone on three different populations of injured rat peripheral motoneurons, i.e. facial (FMN), spinal (SMN) and pudendal (PMN), will be discussed. We have extrapolated concepts from the neuroendocrine field regarding the trophic effects of gonadal steroids on target neural tissue to the nerve regeneration field. Exogenous administration of testosterone immediately after nerve injury impacts positively on functional recovery through actions mediated by the androgen receptor. The mechanism by which steroidal enhancement of the regenerative properties of injured motoneurons occurs may involve pre-existing androgen receptors, heat shock proteins, and modulation of the cellular stress response.

Preinduction cervical ripening. A randomized trial of intravaginal misoprostol alone vs. a combination of transcervical Foley balloon and intravaginal misoprostol.

OBJECTIVE: To determine if the addition of a mechanical ripening agent (transcervical Foley balloon) to a pharmacologic agent (intravaginal misoprostol) improves the efficiency of preinduction cervical ripening. STUDY DESIGN: Singleton patients with an indication for delivery, unfavorable cervix (Bishop score < or = 5) and no contraindication to labor were randomly assigned to two groups: misoprostol alone (25 micrograms intravaginally every 3 hours for no more than 12 hr) or combination therapy (25-French transcervical Foley balloon inflated to 50 mL of sterile water with identical intravaginal misoprostol dosing). All patients received a history and physical examination (including Bishop score), preripening ultrasound, electronic fetal heart rate and contraction monitoring (to rule out spontaneous labor and document fetal well-being). Multiple variables of perinatal outcome were analyzed, including the main outcome variables of ripening-to-delivery time and cesarean section rate. RESULTS: During August 1998 to August 1999, 81 patients were randomized, 40 to misoprostol alone and 41 to combination therapy. There were no differences between the groups with respect to maternal demographics, preripening Bishop score, maternal complications, intrapartum intervention or neonatal outcome. The misoprostol group spent longer periods of time in active labor, and there was a trend for the combination group to require oxytocin for longer intervals. These findings did not significantly affect the total ripening-to-delivery time or cesarean section rate which were similar for both groups. CONCLUSION: The addition of mechanical ripening with a transcervical Foley balloon to intravaginal misoprostol did not improve the efficiency of preinduction cervical ripening. Mechanical and pharmacologic cervical ripening agents appear to act independently rather than synergistically.

Congenital muscular dystrophy with primary partial laminin alpha2 chain deficiency: molecular study.

The authors report a case of congenital muscular dystrophy with mild nonprogressive muscle weakness, white matter hypodensity, and absence of the laminin alpha2 chain in muscle fibers with two antibodies, but not with four others. They identified mutations in LAMA2, which explain the partial laminin alpha2 deficiency. Analysis of this case and two others allows us to refine the epitopes of two of the commercial antibodies, and illustrate the importance of using antibodies directed against different domains of the protein.

The expanding phenotype of laminin alpha2 chain (merosin) abnormalities: case series and review.

Initial reports of patients with laminin alpha2 chain (merosin) deficiency had a relatively homogeneous phenotype, with classical congenital muscular dystrophy (CMD) characterised by severe muscle weakness, inability to achieve independent ambulation, markedly raised creatine kinase, and characteristic white matter hypodensity on cerebral magnetic resonance imaging. We report a series of five patients with laminin alpha2 deficiency, only one of whom has this severe classical CMD phenotype, and review published reports to characterise the expanded phenotype of laminin alpha2 deficiency, as illustrated by this case series. While classical congenital muscular dystrophy with white matter abnormality is the commonest phenotype associated with laminin alpha2 deficiency, 12% of reported cases have later onset, slowly progressive weakness more accurately designated limb-girdle muscular dystrophy. In addition, the following clinical features are reported with increased frequency: mental retardation (~6%), seizures (~8%), subclinical cardiac involvement (3-35%), and neuronal migration defects (4%). At least 25% of patients achieve independent ambulation. Notably, three patients with laminin alpha2 deficiency were asymptomatic, 10 patients had normal MRI (four with LAMA2 mutations reported), and between 10-20% of cases had maximum recorded creatine kinase of less than 1000 U/l. LAMA2 mutations have been identified in 25% of cases. Sixty eight percent of these have the classical congenital muscular dystrophy, but this figure is likely to be affected by ascertainment bias. We conclude that all dystrophic muscle biopsies, regardless of clinical phenotype, should be studied with antibodies to laminin alpha2. In addition, the use of multiple antibodies to different regions of laminin alpha2 may increase the diagnostic yield and provide some correlation with severity of clinical phenotype.

Neurotrophic and migratory properties of an olfactory ensheathing cell line.

Olfactory ensheathing cells (OECs) are a unique type of macroglia required for normal olfactory axonal regeneration throughout the lifetime of an individual. Recent evidence in the literature suggests that OECs transplanted into injured spinal cords may facilitate axonal regeneration. In this study, we evaluated the neurotrophic properties of OECs using a homogeneous clonal cell line (nOEC), which does not contain contaminating cell types found in all primary OEC cultures. The results indicate that nOECs express mRNA for NGF, BDNF, NT-4/5, and neuregulins, but not for NT-3 or CNTF. In addition, nOECs secrete NGF, BDNF, and neuregulin, but retain NT-4/5 intracellularly. Finally, prelabeled nOECs derived from rat survived transplantation into a dorsal hemisected region of the hamster spinal cord and migrated only in the injured, dorsal portion of the spinal cord. This migratory pattern suggests that the nOECs are viable in vivo and respond to signals originating from the injured neuronal cells and their processes.

Detection of retrogradely transported WGA-HRP in axotomized adult hamster facial motoneurons occurs after initiation of the axon reaction.

We have previously shown that facial nerve transection at the stylomastoid foramen activates ribosomal RNA transcription in injured facial motoneurons (FMN) of the adult hamster within 30 minutes postoperative. The signal for the initiation of the nerve cell body response to injury in vertebrates is currently unknown. It has been hypothesized that the signal for initiating the injury response is dependent on retrograde transport, where the signal itself is either the loss of a repressor substance from the periphery or the loss of retrogradely transported target-derived factors. To examine if a retrograde transport-mediated signal would be sufficient to produce the rapid ribosomal effects observed in hamster FMN following injury, adult hamsters were subjected to right facial nerve axotomies, with the neuronal tracer wheat germ agglutinin horseradish peroxidase (WGA-HRP; M.W. 80,000) applied at the proximal stump of the transected nerve. At time points ranging from 0.5 to 24 hours postoperative (hpo), the animals were killed and brainstem sections containing bilateral facial nuclei processed for WGA-HRP label using the TMB method. The earliest time point at which WGA-HRP was detected in the axotomized facial nucleus occurred at 3 hpo. To eliminate molecular weight as a confounding factor, an additional retrograde transport study was performed using the smaller tracer, Fluoro-Gold (M.W. 532.59). Fluoro-Gold was not detected until well after the 3 hpo time point. Thus, it appears that initiation of the axon reaction in hamster FMN is likely to be independent of the retrograde transport properties of the injured neuron.