Apomorphine-induced blinking and yawning in healthy volunteers.

Yawning and spontaneous blink rate (SBR) are two physiological reflexes which have been incompletely examined but one neurobiological step of these two behaviours seems, at least in part, dopamine-dependent. The reference dopaminergic agonist, apomorphine hydrochloride (0.5, 1, and 2 micrograms kg-1 s.c.), was compared with a placebo in a double-blind latin-square design, and was shown to induce yawning and increase SBR in a population of eight healthy volunteers. These two behavioral effects were not dose-related. The individual SBR differences were correlated with the individual number of yawns for all the four treatments at the 10-30 min interval. Thus, parallel yawning and SBR behaviour suggests a similar pharmacological mechanism. Apomorphine-induced yawning and blinking may be therefore of use in the evaluation of central dopaminergic pathways in man.     

CXCR4 and Gab1 cooperate to control the development of migrating muscle progenitor cells

Long-range migrating progenitor cells generate hypaxial muscle, for instance the muscle of the limbs, hypoglossal cord, and diaphragm. We show here that migrating muscle progenitors express the chemokine receptor CXCR4. The corresponding ligand, SDF1, is expressed in limb and branchial arch mesenchyme; i.e., along the routes and at the targets of the migratory cells. Ectopic application of SDF1 in the chick limb attracts muscle progenitor cells. In CXCR4 mutant mice, the number of muscle progenitors that colonize the anlage of the tongue and the dorsal limb was reduced. Changes in the distribution of the muscle progenitor cells were accompanied by increased apoptosis, indicating that CXCR4 signals provide not only attractive cues but also control survival. Gab1 encodes an adaptor protein that transduces signals elicited by tyrosine kinase receptors, for instance the c-Met receptor, and plays a role in the migration of muscle progenitor cells. We found that CXCR4 and Gab1 interact genetically. For instance, muscle progenitors do not reach the anlage of the tongue in CXCR4;Gab1 double mutants; this target is colonized in either of the single mutants. Our analysis reveals a role of SDF1/CXCR4 signaling in the development of migrating muscle progenitors and shows that a threshold number of progenitor cells is required to generate muscle of appropriate size.     

Exploring the potential association among sleep disturbances,cognitive impairments,and immune activation in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.DS) is a neurogenetic disorder caused by a microdeletion in chromosome 22. Its phenotype includes high rates of psychiatric disorders, immune system abnormalities, and cognitive impairments. We assessed the quality of sleep in 22q11.2DS and its potential link to inflammatory markers and cognitive deficits. Thirty‐three 22q11.2DS individuals and 24 healthy controls were studied. Sleep parameters were assessed by the Pittsburgh sleep quality index (PSQI) questionnaire and correlated with serum cytokine levels and cognitive functioning, measured using the Penn computerized neurocognitive battery (CNB). The 22q11.2DS individuals had significantly worse sleep quality scores than the controls, unrelated to the psychiatric or physical comorbidities common to 22q11.2DS. Interleukin 6 levels were correlated with the overall score of the PSQI questionnaire for nonpsychotic 22q11.2DS participants only. Several domains of the CNB were associated with poorer sleep quality, suggesting that cognitive impairments in 22q11.2DS may be at least partially explained by poor sleep quality. Our findings confirm sleep impairments in individuals with 22q11.2DS, which might negatively affect their cognitive functioning, and corroborate a potential role of immunological pathways in the 22q11.2DS neuro‐phenotype.     

Prenatal detection of a 17p11.2 duplication resulting from a rare recombination event and novel PCR-based strategy for molecular identification of Charcot-Marie-Tooth disease type 1A

Charcot-Marie-Tooth disease, type 1A (CMT1A) is caused in most cases by a 1.5 Mb duplication on chromosome 17p11.2 arising after unequal crossing-over between repeated sequences called CMT1A-REPs, flanking the 1.5 Mb unit. A 3.2 kb recombination hot spot has been defined, resulting in a junction fragment between EcoRI (distal CMT1A-REP) and SacI (proximal CMT1A-REP). This was further reduced to a 1.7kb EcoRI-NsiI fragment, and recently to a 731 bp hot spot region within this fragment. We describe the CMT1A-REPs-based PCR method used to identify CMT1A duplications and report on a family case in which a 29-year-old pregnant woman requested prenatal diagnosis for two successive pregnancies because her husband was affected with CMT1A. Our method enabled us to characterise the duplication in both foetuses and demonstrate that it arose from a rare recombination event taking place outside the 1.7 kb region. Since our approach is simple and enables the entire set of duplications occurring after recombination in the enlarged 3.2kb region including the hot spot to be detected, we suggest it might be considered for use in primary screening for pre- and postnatal diagnosis of CMT1A.     

Subtotal gastrectomy in a teenager with gastroparesis

Disorders of gastric emptying are rare in healthy infants and children. Delayed gastric emptying is encountered in adults after operations on the stomach, such as vagotomy and partial gastrectomy, and is extremely rare in young patients. The authors report on a 15-year-old patient with gastroparesis after three attempts to repair a congenital diaphragmatic hernia. Medical therapeutic trials consisting of all combinations of diet regimes with various gastrokinetic drugs failed to alleviate the intractable vomiting. All the patient's symptoms resolved after subtotal gastrectomy with gastroduodenostomy (Billroth I).     

Lower motor neuron disease and signs of dysimmunity

Twenty-two patients (12 men, 10 women, age range 16 to 60) affected with an adult-onset, sporadic, lower motor neuron disease were studied. Motor weakness was associated with a severe muscular atrophy but never in a peripheral nerve distribution. Weakness predominated in the proximal parts of the limbs in 3 cases, in distal parts in 10 cases involving predominantly the upper limbs in 10. It was diffuse in all four limbs in six cases and was monomelic in the last 2 two others. Reflexes were generally lost in weak muscles. Electrodiagnostic findings consisted of pure motor axonal features, subtle sensory involvement was present in 3 cases with an IgM monoclonal gammopathy, in only one case the neurological syndrome was associated with a lymphoproliferative disorder despite complete investigations. All patients had dysimmune biological features (MGUS or anti-GM1 antibodies). We studied SMN gene in 12 patients and found no deletion. 16 patients were treated with IVIg and five improved but in 2 cases the improvement was transcient and lasted less than six months. Intravenous cyclophosphamide (1g/m(2) repeated monthly during 6 to 9 months) was used in six patients and three improved. Among these three patients two received also plasma exchanges on two days before the infusion. In all three patients, muscle weakness gradually deteriorated in the months following the end of the treatment. Nor the weakness pattern nor the type of biological marker was predictive of a good response to treatment. Lower motor neuron diseases appear to be much less sensitive to treatment than multifocal motor neuropathy with conduction block. However, treatment with IVIg or cyclophosphamide must be considered in the most severe forms or in case of a young onset.     

Extra-anatomic aortic bypass via sternotomy for complex aortic arch stenosis in children

OBJECTIVE: Recurrent aortic narrowing after repair of aortic coarctation or interrupted aortic arch, as well as diffuse, long-segment aortic hypoplasia, can be difficult to manage. Extra-anatomic ascending aorta-descending aorta bypass grafting through a sternotomy is an alternative approach for this problem. METHODS: Since 1985, 19 patients aged 2 months to 18 years (mean 10.7 years) underwent extra-anatomic bypass with 10- to 30-mm Dacron grafts. The initial diagnosis was coarctation with hypoplastic arch in 15, interrupted aortic arch in 3, and diffuse long-segment aortic hypoplasia in 1. Seventeen of the children had a total of 22 previous operations: transthoracic interposition or bypass graft (n = 7), end-to-end anastomosis (n = 7), subclavian arterioplasty (n = 6), and synthetic patch (n = 2). The mean time from initial repair was 8.0 years (range 0.6-18 years). Three children had previous sternotomies. Cardiopulmonary bypass was avoided in all but 6 patients (5 with simultaneous intracardiac repairs). RESULTS: No hospital or late deaths occurred. On follow-up from 4 months to 14.7 years (mean 7.9 years), no reoperations for recurrent stenosis were performed. Two patients have arm-to-leg pressure gradients: 20 mm Hg at rest in 1 patient and a 60-mm Hg systolic exercise gradient with no resting gradient in the other. One patient required exclusion of an aortic aneurysm at the old coarctation repair site 13 years after extra-anatomic bypass. Three children had subsequent successful cardiac operations. CONCLUSIONS: Extra-anatomic bypass is an effective and relatively easy approach for selected cases of complex or reoperative aortic arch obstruction. It should be considered as an alternative operative technique for complex aortic arch reconstruction.     

Monkeypox DNA levels correlate with virus infectivity in clinical samples,Israel, 2022

The current monkeypox virus global spread and lack of data regarding clinical specimens’ infectivity call for examining virus infectivity, and whether this correlates with results from PCR, the available diagnostic tool. We show strong correlation between viral DNA amount in clinical specimens and virus infectivity toward BSC-1 cell line. Moreover, we define a PCR threshold value (Cq ≥ 35, ≤ 4,300 DNA copies/mL), corresponding to negative viral cultures, which may assist risk-assessment and decision-making regarding protective-measures and guidelines for patients with monkeypox.     

The Sheba Medical Center healthcare workers' children's school: can we open schools safely?

ObjectiveThe role of school closure in mitigating coronavirus disease 2019 (COVID-19) transmission has been questioned. In our medical centre, during a 9-week national lockdown, an alternative school was opened for health-care workers' (HCW) children with a small number of children per class and strict symptom surveillance. After lockdown was lifted we screened children and their parents for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology.MethodsWe conducted a cross-sectional study of HCW parents and their children after one teacher contracted COVID-19 following exposure at home and 53 children were exposed, isolated and tested by RT-PCR. We compared families with children attending the alternative school with families whose children who remained at home during the 9-week lockdown. Epidemiological and medical data were collected using a short questionnaire; nasopharyngeal and oropharyngeal swabs were obtained and tested for SARS-CoV-2 by RT-PCR, and blood was collected for SARS-CoV-2 IgA and IgG titres.ResultsA total of 435 children attended the Sheba alternative school. Among the 53 children exposed to the infected teacher, none tested positive by RT-PCR. Of these, 18 children–parent pairs were tested for serology and all were negative. A total of 106/435 (24%) children and their 78 parents were recruited for the cross-sectional study; 70 attended the Sheba school and 36 did not. Approximately 16% of children in either group reported symptoms (11/70 in the school group and 6/36 in the ‘stay home’ group), but SARS-CoV-2 was not detected by PCR in any, and previous exposure, as determined by serological tests, was low and not significantly different between the groups.ConclusionIn an alternative school for children of HCWs, active during COVID-19 national outbreak, we found no evidence of increased infection compared with children that stayed home.     

Directing exocrine secretory vesicles to the apical membrane by actin cables generated by the formin mDia1

The final stage in exocrine secretion involves translocation of vesicles from their storage areas to the apical membrane. We show that actin-coated secretory vesicles of the exocrine pancreas travel this distance over bundles of specialized actin cables emanating from the apical plasma membrane. These bundles are stable structures that require constant G-actin incorporation and are distinct from the actin web that surrounds the exocrine lumen. The murine mammalian Diaphanous-related formin 1 (mDia1) was identified as a generator of these cables. The active form of mDia1 localized to the apical membrane, and introduction of an active form of mDia1 led to a marked increase in bundle density along the lumen perimeter. Compromising formation of the cables does not prevent secretion, but results in disorganized trafficking and fusion between secretory vesicles. Similar apical secretory tracks were also found in the submandibular salivary glands. Together with previous results that identified a role for Diaphanous in apical secretion in tubular organs of Drosophila, the role of Diaphanous formins at the final stages of secretion appears to be highly conserved.