Usefulness of High-Quality Core Genome Single-Nucleotide Variant Analysis for Subtyping the Highly Clonal and the Most Prevalent Salmonella enterica Serovar Heidelberg Clone in the Context of Outbreak Investigations.

Salmonella enterica serovar Heidelberg is the second most frequently occurring serovar in Quebec and the third-most prevalent in Canada. Given that conventional pulsed-field gel electrophoresis (PFGE) subtyping for common Salmonella serovars, such as S. Heidelberg, yields identical subtypes for the majority of isolates recovered, public health laboratories are desperate for new subtyping tools to resolve highly clonal S. Heidelberg strains involved in outbreak events. As PFGE was unable to discriminate isolates from three epidemiologically distinct outbreaks in Quebec, this study was conducted to evaluate whole-genome sequencing (WGS) and phylogenetic analysis as an alternative to conventional subtyping tools. Genomes of 46 isolates from 3 Quebec outbreaks (2012, 2013, and 2014) supported by strong epidemiological evidence were sequenced and analyzed using a high-quality core genome single-nucleotide variant (hqSNV) bioinformatics approach (SNV phylogenomics [SNVphyl] pipeline). Outbreaks were indistinguishable by conventional PFGE subtyping, exhibiting the same PFGE pattern (SHEXAI.0001/SHEBNI.0001). Phylogenetic analysis based on hqSNVs extracted from WGS separated the outbreak isolates into three distinct groups, 100% concordant with the epidemiological data. The minimum and maximum number of hqSNVs between isolates from the same outbreak was 0 and 4, respectively, while >59 hqSNVs were measured between 2 previously indistinguishable outbreaks having the same PFGE and phage type, thus corroborating their distinction as separate unrelated outbreaks. This study demonstrates that despite the previously reported high clonality of this serovar, the WGS-based hqSNV approach is a superior typing method, capable of resolving events that were previously indistinguishable using classic subtyping tools.

A public health enhanced surveillance system for a mass gathering event.

BACKGROUND: From June 7 to June 9, 2018, a G7 Summit was held in the Canadian province of Quebec. This international political mass gathering event posed a number of potential risks to public health. OBJECTIVE: To assess three additional monitoring strategies to detect public health threats during a mass gathering event. INTERVENTION: In addition to routine public health monitoring, a partnership was created and three monitoring strategies were put in place three days before, during and six days after the G7 event: the analysis of data on the presenting complaint and discharge diagnosis from 11 emergency departments in the area using the logical Early Aberration Reporting System; the daily polling of key health partners with an online questionnaire; and the analysis of calls to Info-Santé, a government-run telephone consultation service for the public regarding health and social issues. RESULTS: Emergency room data produced 78 alerts from the presenting complaints and 39 alerts from the discharge diagnoses. Of these 117 alerts, two were investigated (one in the respiratory and one in the neurological-muscular categories) and no other interventions were required. With a few exceptions, all of the health partners completed the online survey each day and no signal of concern was generated. Compared with historical data, no increase or differences in calls to Info-Santé were detected during the monitoring period. CONCLUSION: The three additional monitoring strategies developed to detect events of public health importance during the 2018 G7 Summit in Quebec were successful in gathering timely data for analysis. Close collaboration and good participation from the different partners were essential to this project. However, because no public health event occurred, it was not possible to determine whether the enhanced surveillance system had sufficient speed and sensitivity for timely detection and response.

Hypertrophy and hyperplasia of abdominal adipose tissues in women.

OBJECTIVE: To examine the expression of selected transcription factors involved in adipogenesis and genes related to lipid metabolism in abdominal subcutaneous and omental fat tissue. RESEARCH DESIGN AND METHODS: We obtained subcutaneous and omental adipose tissue samples from 40 women undergoing abdominal hysterectomies (age: 47+/-5 years; BMI 27.9+/-5.3 kg/m(2)). We measured isolated adipocyte size and metabolism, and detailed measures of body fat accumulation and body fat distribution were obtained (dual-energy X-ray absorptiometry and computed tomography, respectively). RESULTS: Adipocyte size of both subcutaneous and omental fat were increased with higher body fat mass values, with similar regression slopes in each compartment. In contrast, with higher body fat mass values, fat accumulation was progressively higher in the subcutaneous than in the visceral fat compartment, suggesting hyperplasia in the subcutaneous fat compartment. Messenger RNA levels of CEBPalpha, PPARgamma2, SREBP1c and genes related to lipid metabolism (LPL, FABP4, DGAT1, DGAT2, PLIN and HSL) were significantly higher in subcutaneous than in omental fat tissue (P< or =0.001 for all). Only subcutaneous expression of these genes tracked with obesity levels as reflected by significant positive associations between subcutaneous fat CEBPalpha, SREBP1c and DGAT2 expression and total body fat mass (r=0.37, r=0.41, r=0.57, respectively, P< or =0,05), fat percentage (r=0.40, r=0.39, r=058, respectively, P< or =0,05) and subcutaneous adipose tissue area (r=0.36, r=0.38, r=0.58, respectively, P< or =0,05). Omental adipose tissue expression levels of these genes were not significantly related to adiposity measures. CONCLUSIONS: These results show that in obese women, hyperplasia is predominant in the subcutaneous fat depot, whereas fat cell hypertrophy is observed both in the omental and subcutaneous compartments.

Increased cyclic guanosine monophosphate production and overexpression of atrial natriuretic peptide A-receptor mRNA in spontaneously hypertensive rats.

Atrial natriuretic peptide (ANP) specifically stimulates particulate guanylate cyclase, and cyclic guanosine monophosphate (cGMP) has been recognized as its second messenger. Spontaneously hypertensive rats (SHR) have elevated plasma ANP levels, but manifest an exaggerated natriuretic and diuretic response to exogenous ANP when compared to normotensive strains. In isolated glomeruli, the maximal cGMP response to ANP corresponds to a 12- to 14-fold increase over basal levels in normotensive strains (Wistar 13 +/- 2; Wistar-Kyoto 12 +/- 2; Sprague-Dawley 14 +/- 2) while a maximal 33 +/- 3-fold elevation occurs in SHR (P < 0.001). This hyperresponsiveness of cGMP is reproducible in intact glomeruli from SHR from various commercial sources. Furthermore, this abnormality develops early in life, even before hypertension is clearly established, and persists despite pharmacological modulation of blood pressure, indicating that it is a primary event in hypertension. In vitro studies have revealed a higher particulate guanylate cyclase activity in membranes from glomeruli and other tissues from SHR. This increase is not accounted for by different patterns of ANP binding to its receptor subtypes between normotensive and hypertensive strains, as assessed by competitive displacement with C-ANP102-121, an analog which selectively binds to one ANP receptor subtype. The hyperactivity of particulate guanylate cyclase in SHR and its behavior under basal, ligand (ANP), and detergent-enhanced conditions could be attributed either to increased expression or augmented sensitivity of the enzyme. Radiation-inactivation analysis does not evoke a disturbance in the size of regulatory elements normally repressing enzymatic activity, while the expression of particulate guanylate cyclase gene using mutated standard of A- and B-receptors partial cDNAs, quantified by polymerase chain reaction (PCR) transcript titration assay, manifests a selective increase of one guanylate cyclase subtype. Our data suggest that in hypertension, genetic overexpression of the ANP A-receptor subtype is related to the exaggerated biological response to ANP in this disease.

Exophytic bulbar pilocytic astrocytoma and post-operative cerebral salt wasting syndrome.

Cerebral salt wasting syndrome (CSWS) is a well-described consequence of several neurological disorders. Although the exact etiology of CSWS is still not completely elucidated, it is believed that the hypothalamus plays a pivotal role in the genesis of this disorder. We report for the first time 3 cases of CSWS occurring during the post-operative course following surgical resection of exophytic bulbar pilocytic astrocytomas in children. Since these 3 cases shared in common a medial implication of the medulla, we suggest that specific interconnectivity between the dorso-medial portion of the medulla oblongata and the hypothalamus might thus represent an anatomical pathway of interest in the pathogenesis of CSWS. Our findings suggest that the resection of medially located exophytic bulbar tumors might constitutes a risk factor in the development of CSWS. Particular care should thus be carried towards the prompt detection and treatment of CSWS in the post-operative courses of exophytic bulbar tumors.

A novel mechanism for isolated central hypothyroidism: inactivating mutations in the thyrotropin-releasing hormone receptor gene.

Isolated central hypothyroidism, characterized by insufficient TSH secretion resulting in low levels of thyroid hormones, is a rare disorder. We report a boy in whom isolated central hypothyroidism was diagnosed at 9 yr of age. Complete absence of TSH and PRL responses to TRH led us to speculate that he had an inactivating mutation of the TRH receptor gene. The patients' genomic DNA was isolated, and the entire coding region of the TRH receptor was amplified by the PCR and sequenced directly. Confirmation of the mutations and haplotyping of the family was performed using restriction enzymes. The biological activity of the wild-type and mutated TRH receptors was verified by evaluating the binding of labeled TRH and stimulation by TRH of total inositol phosphate accumulation in transfected HEK-293 and COS-1 cells. The patient was found to be a compound heterozygote, having inherited a different mutated allele from each of the parents; both mutations were in the 5'-part of the gene. Mutated receptors were unable to bind TRH and to activate total inositol phosphate accumulation. Our report is the first description of naturally occurring inactivating mutations of a G protein-coupled receptor linked to the phospholipase C second messenger pathway. The prevalence and phenotypic spectrum of TRH receptor mutations in isolated central hypothyroidism remain to be established.

Severe autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy in an adolescent girl with a novel AIRE mutation: response to immunosuppressive therapy.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder for which the gene (AIRE) has recently been identified on chromosome 21q22.3. We present the mutational analyses of a French-Canadian family with APECED, in which there are two affected siblings, as well as the response to cyclosporine A(CyA) therapy in the index patient, the eldest sibling. Haplotype analysis suggested compound heterozygozity at the AIRE locus. Direct sequencing of exon 8 revealed a previously described mutation, a 13-bp deletion (1085-1097) of maternal origin, found in the index patient, her affected sister, and her unaffected sister. A novel missense mutation characterized by a T-->G transversion at nucleotide position 398, resulting in a leu-->arg amino acid substitution (L93R), was found in exon 2. The mutation was present in the father, the brother, the index patient, and the affected sister. The presence of the mutation in the propositus was verified by cloning of PCR products from genomic DNA. The mutation destroys a PstI restriction enzyme site, as confirmed in the aforementioned patients. Screening of 50 French-Canadian controls with PstI digestion did not show destruction of the restriction-enzyme site. The index patient's phenotype was severe, manifested by classic features of the illness (adrenal insufficiency, hypoparathyroidism, candidiasis, and keratoconjunctivitis with alopecia universalis), as well as by severe exocrine pancreatic insufficiency, diabetes mellitus, hepatic inflammation, growth hormone (GH) deficiency due to lymphocytic hypophysitis, and primary ovarian failure. Oral CyA (5 mg/kg/day) was initiated at 13 yr of age. After 8 months of therapy, stimulated pancreatic lipase increased 24-fold with normalization of stool fat (from 31.5 g/day to 2.5 g/day, normal(N) < 5). There was complete resolution of her photophobia, and considerable hair regrowth was diffusely apparent. Minimal side effects were noted. Our experience supports the use of oral CyA for the treatment of severe APECED-associated exocrine pancreatic failure and keratoconjunctivitis.

Control of phospholipid turnover and prolactin release in a dopamine-sensitive, prolactin-secreting rat pituitary adenoma and in two dopamine-resistant, prolactin-secreting rat pituitary tumors.

Abstract The secretion of prolactin by the pituitary gland is under a tonic inhibitory control exerted by tubero-infundibular dopamine. Recently, it has been suggested that dopamine may exert its action by inhibiting production of inositol phosphates and mobilization of intracellular Ca(2+). To study the effects of dopamine on the production of inositol phosphates and prolactin release, we have utilized an estrone-induced, dopamine-sensitive rat pituitary adenoma and two transplantable and dopamine-resistant rat pituitary tumors, 7315a and MtTW15. Purified cells, obtained from the three tissues, were incubated for 30 min in media with drugs (thyrotropin-releasing hormone or angiotensin II) stimulating inositol phosphates and prolactin release, in the presence or the absence of dopamine. Basal production of inositol phosphates and prolactin release by adenomatous lactotrophs were inhibited by dopamine. Thyrotropin-releasing hormone and angiotensin II stimulated inositol phosphates by adenomatous and 7315a cells. This effect was antagonized by dopamine in adenomatous cells. Prolactin release by adenomatous cells only was stimulated by thyrotropin-releasing hormone and angiotensin II. This stimulation was inhibited by dopamine. The results show differences, in the mechanisms of regulation of prolactin release, between adenoma and transplantable pituitary tumors as well as between the two tumors themselves. These differences may be responsible, in part, for the resistance of the two transplantable pituitary tumors to the inhibitory effects of dopamine on prolactin release and tumor size. Our results obtained both with adenoma and tumoral cells also suggest that inositol phosphates probably intervene only in the late phases of dopamine inhibition of prolactin release and only in the presence of a normal Ca(2+) signaling system.

Growth and pubertal development following pediatric heart transplantation: a 15-year experience at Ste-Justine Hospital.

BACKGROUND: Thirty-one children and adolescents have undergone allograft heart transplantation at Ste-Justine Hospital from July 1984 to August 1996. Twenty-five patients were followed prospectively more than 3 years to document their growth and pubertal development. METHODS: Parameters surveyed were clinical (height, weight, pubertal staging, and bone age) and biochemical (luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, estradiol, dehydroepiandrosterone sulphate (DHEAS), IGF-1, and fasting insulin). RESULTS: At surgery, there were 18 boys and 7 girls aged 11 months to 17 years (median 13 years); 14 had congenital heart defects (CHDs) and 11 had a cardiomyopathy (CM). Immunosuppressive therapy included cyclosporine, azathioprine, and prednisone. Eighteen patients were still growing (15 boys, 3 girls): 8 had a retarded bone age and 6 with CHD had severe growth failure. Following surgery, most patients maintained their height within one sodium dodecyl sulfate (SDS) score of that initially observed. Patients reaching their target heights do so mainly in the lower range. Three patients not reaching target height had a CHD. Weight was greatest 1 year postoperatively (113 +/- 27% ideal body weight) with normalization at 2 years (100 +/- 18%). Of the 13 prepubertal patients, menarche occurred at age 12 in 1 girl, while 3 boys began puberty at age 12 years. In both sexes, serum levels of gonadotropins and IGF-1 increased during puberty, moderate hyperinsulinism was observed, and DHEAS levels decreased. CONCLUSIONS: Our results indicate that children and adolescents grow normally following cardiac transplantation and that they attain their target height despite a lack of catch-up growth. They gain weight significantly in the first postoperative year with normalization of their weight at 2 years. Furthermore, the clinical and biochemical indices of puberty are overall within the norms. However, the severity of growth delay at the time of transplantation inherent to the cardiac pathology has a major impact on adult height.

Congenital malformations associated with maternal use of valproic acid.

Two children born with birth defects after intrauterine exposure to valproic acid are reported. The mothers took the drug throughout pregnancy as sole treatment for primary generalized epilepsy. The first baby showed facial dysmorphism, arachnodactyly and triphalangeal thumbs. The second had facial dysmorphism, severe laryngeal hypoplasia, tracheomalacia and an aberrant innominate artery that caused tracheal compression. A left superior vena cava, abnormal pulmonary lobulation, and unilateral hydronephrosis were also found at autopsy. Valproic acid has probable teratogenic potential in humans but the number of reported cases is few and the spectrum of anomalies is broad so it is not possible to delineate a definite fetal valproate syndrome.

Prophylactic thyroidectomy for medullary thyroid carcinoma in gene carriers of MEN2 syndrome.

BACKGROUND/PURPOSE: Although medullary thyroid carcinoma (MTC) can occur sporadically, in the pediatric population it is most often associated with the multiple endocrine neoplasia syndrome (MEN type 2). Traditional screening was based on evaluation of basal and stimulated serum calcitonin levels. The recent cloning of the MEN2 gene on the RET proto-oncogene of chromosome 10 now allows for testing of gene carrier status in individuals at risk who could benefit from prophylactic treatment. The current study was undertaken to determine the appropriate age for safe total prophylactic thyroidectomy. METHODS: Over a 16-year period, 12 patients with a family history of MEN2A and one with a MEN2B underwent total thyroidectomy and central neck dissection without parathyroid autotransplantation. Four patients (31%) were treated previously for Hirschsprung's disease. RESULTS: In seven patients (mean age, 11.8 years) undergoing biochemical screening for diagnosis, multifocal MTC and C cell hyperplasia (CCH) were found in all the resected specimens. Of six patients identified with genetic screening (mean age, 9.1 years), two had elevated stimulated calcitonin levels, one (age 14) had evidence of MTC, and one (age 6) had CCH. Four patients with normal calcitonin levels had no evidence of MTC (ages 6, 8, 10) but there was one occurrence of CCH (age 11). No permanent postoperative hypoparathyroidism or recurrent laryngeal nerve damage occurred in this series. With a mean follow-up of 4 years (range, 1 to 14 years), the overall disease-free survival is 100%. CONCLUSIONS: From this study the authors conclude that total thyroidectomy can be performed safely in children and should be the treatment of choice in patients with a family history of MEN2A carrying a germinal RET mutation even if the serum basal or stimulated serum calcitonin level is normal. Total thyroidectomy should be performed as early as 5 years of age before the occurrence of CCH or MTC.

[Growth and pubertal development following pediatric heart transplantation]. / Croissance et développement pubertaire après transplantation cardiaque pédiatrique.

STUDY AIM: Prospective study of growth and pubertal development following pediatric heart transplantation in 25 children. PATIENTS AND METHOD: Twenty-five children underwent orthotopic cardiac transplantation at Ste-Justine Hospital from July 1984 to August 1996. Systematic evaluation of anthropometric parameters (weight, height, bone age), hormonal profile (LH, FSH, testosterone, oestradiol, DHEAS), and pubertal development according to Marshall and Tanner were done yearly. RESULTS: Six patients had severe growth retardation at transplantation and only one patient was obese. All patients showed normal height increment following cardiac transplantation. Only 3 patients will not reach genetic target height. The 6 children suffering from congenital cardiomyopathy and showing severe growth delay before surgery did not show any significant catch up growth. Significant weight gain was observed during the first post-operative year (113 +/- 27% ideal body weight p = 0.0002) with evolution towards normal values at 2 years (100 +/- 18%). Thirteen patients were in the prepubertal stage at the time of transplant. Since then, one girl had her menarche at 11 years of age and 3 boys started their pubertal onset at 12 years old. The elevation of blood gonadotrophins during pubertal development correlated with progression of secondary sexual characteristics in both sexes. CONCLUSION: This pediatric population showed normal growth and normal onset and progression of puberty following cardiac transplantation. However, no catch-up growth was observed. The most important factor influencing attainment of maximal growth potential following heart transplantation was the degree of staturoponderal growth retardation at the time of surgery.

[Pubertal development after pediatric heart transplantation]. / Développement pubertaire après la greffe cardiaque pédiatrique.

Twenty-one children and adolescents underwent orthotopic cardiac transplantation at the Hôpital Sainte-Justine between July 1984 and June 1993. Of those patients, 16 (4 girls and 12 boys) who survived more than one year after the procedure were followed prospectively for documentation of onset and progression of puberty. The immunosuppressive therapy included cyclosporine, azathioprine and prednisone. Subjects were evaluated at 6 month intervals for the study of: pubertal development according to staging by the method of Marshall and Tanner and hormonal profile (FSH, LH, testosterone, DHEAS). Despite a stagnation of pubertal signs before surgery, puberty carried on and progressed normally postoperatively. The urinary levels of gonadotropins rose to adequate levels for age. Testosterone levels in boys were related to the progression of secondary sexual characteristics. Levels of DHEAS were drastically reduced, most likely because of the supraphysiological doses of oral glucocorticoids. Our results indicate that after pediatric heart transplantation, puberty progresses normally at adolescence.

The impact of exercise consultation on activity levels and metabolic markers in obese adolescents: a pilot study.

Objective. To assess the impact of exercise consultation on physical activity (PA) levels, anthropometric measures, and metabolic markers in obese adolescents. Methods. Obese adolescents (14-18 years) were randomized to either an exercise consultation (intervention group) or to review "Canada's Physical Activity Guide for Youth" (control group). Outcomes, including accelerometry, anthropometrics, blood pressure, stage of exercise behavior change, fasting glucose, insulin, and lipids, were measured at baseline and 3 months later. Results. Thirty adolescents (mean BMI = 36.1 kg/m(2); SD = 6.9) completed the study. At follow-up, the intervention group had significantly greater PA compared with controls (P < .05). Similarly, the intervention group weighed an average 2.6 kg less than the control group (P < .05), with a mean BMI z-score of 2.15 compared to 2.21 for controls (P = .054). No other differences were noted. Conclusion. Exercise consultation may be a simple approach to increase PA levels, reduce weight, and lower BMI in obese adolescents.

Cell biology of atrial natriuretic peptide.

Atrial natriuretic peptide (ANP) exhibits a wide spectrum of cardiovascular, endocrine, metabolic and renal actions. cGMP is the major mediator of ANP at the cellular level and only tissues possessing particulate guanylate cyclase appear to present ANP-induced actions. Three types of ANP receptors have recently been cloned. Two of them (A and B receptors) are homologous and contain guanylate cyclase catalytic domains. The C receptor could possibly regulate the metabolic fate of ANP. Data obtained by the radiation inactivation method suggest the presence of an inter- or intramolecular inhibitory component of nearly 90 kilodaltons that represses the catalytic activity of guanylate cyclase within its membrane environment. The mechanism of guanylate cyclase stimulation by ANP could involve this inhibitory component. Preliminary data suggest that the hyperresponsiveness of the particulate guanylate cyclase/cGMP system in hypertension occurs through modulation of the inhibitory component.

Reduced pituitary volume in children with short stature: clinical and radiological correlates.

A retrospective evaluation of 80 cases of growth retardation evaluated at the Hôpital Sainte-Justine of Montreal has revealed that 20 of them (25%; 15 boys and 5 girls) had a reduction of pituitary volume as revealed by high-resolution CT scanning of the pituitary gland. Of these patients, 8 had complete growth hormone (GH) deficiency, as evaluated by arginine infusion and L-Dopa-propranolol testing and nocturnal blood sampling, and 3 had GH neurosecretory dysfunction. Five patients had combined or multiple hormonal deficiencies. A statistically significant correlation was found between nocturnal plasma GH values and pituitary volumes. From this study it can be concluded that reduced pituitary volume is a frequent finding in growth-retarded children with hypopituitarism.