Neural Stimulation Hardware for the Selective Intrafascicular Modulation of the Vagus Nerve.

The neural stimulation of the vagus nerve is able to modulate various functions of the parasympathetic response in different organs. The stimulation of the vagus nerve is a promising approach to treating inflammatory diseases, obesity, diabetes, heart failure, and hypertension. The complexity of the vagus nerve requires highly selective stimulation, allowing the modulation of target-specific organs without side effects. Here, we address this issue by adapting a neural stimulator and developing an intraneural electrode for the particular modulation of the vagus nerve. The neurostimulator parameters such as amplitude, pulse width, and pulse shape were modulated. Single-, and multi-channel stimulation was performed at different amplitudes. For the first time, a polyimide thin-film neural electrode was designed for the specific stimulation of the vagus nerve. In vivo experiments were performed in the adult minipig to validate to elicit electrically evoked action potentials and to modulate physiological functions, validating the spatial selectivity of intraneural stimulation. Electrochemical tests of the electrode and the neurostimulator showed that the stimulation hardware was working correctly. Stimulating the porcine vagus nerve resulted in spatially selective modulation of the vagus nerve. ECAP belonging to alpha and beta fibers could be distinguished during single- and multi-channel stimulation. We have shown that the here presented system is able to activate the vagus nerve and can therefore modulate the heart rate, diastolic pressure, and systolic pressure. The here presented system may be used to restore the cardiac loop after denervation by implementing biomimetic stimulation patterns. Presented methods may be used to develop intraneural electrodes adapted for various applications.

Decoding bladder state from pudendal intraneural signals in pigs.

Neuroprosthetic devices used for the treatment of lower urinary tract dysfunction, such as incontinence or urinary retention, apply a pre-set continuous, open-loop stimulation paradigm, which can cause voiding dysfunctions due to neural adaptation. In the literature, conditional, closed-loop stimulation paradigms have been shown to increase bladder capacity and voiding efficacy compared to continuous stimulation. Current limitations to the implementation of the closed-loop stimulation paradigm include the lack of robust and real-time decoding strategies for the bladder fullness state. We recorded intraneural pudendal nerve signals in five anesthetized pigs. Three bladder-filling states, corresponding to empty, full, and micturition, were decoded using the Random Forest classifier. The decoding algorithm showed a mean balanced accuracy above 86.67% among the three classes for all five animals. Our approach could represent an important step toward the implementation of an adaptive real-time closed-loop stimulation protocol for pudendal nerve modulation, paving the way for the design of an assisted-as-needed neuroprosthesis.

Deletion of the SHOX gene in patients with short stature of unknown cause.

A fluorescence in situ hybridization (FISH) study was performed in 56 patients with short stature of unknown cause in order to establish the role of deletion of the SHOX gene in this population. FISH analysis was carried out on metaphase spreads and interphase lymphocytes from blood smears using a probe specific for the SHOX gene. Deletion of SHOX was found in four patients (7.1%). No skeletal abnormalities were detected in these patients either at the physical examination or at X-rays of the upper and lower limbs. Present results indicate that SHOX plays an important role also in short stature of unknown cause, and FISH analysis appears as an easy, appropriate, and inexpensive method for the detection of SHOX deletion.

Spectrum of clinical variability in familial deletion 22q11.2: from full manifestation to extremely mild clinical anomalies.

The 22q11.2 deletion (del22q11.2) syndrome is a genetic condition with wide interfamilial and intrafamilial variability in clinical expression. The aim of the present study was to review the prevalence of parental transmission in our series of patients with del22q11.2, and to analyse clinical findings of the affected parents. Parental transmission of del22q11.2 in our series was 17.2% (15/87), with a preferential maternal transmission (10/15). One or more major features of del22q11.2 were found in all deleted parents, but one of the mothers showed extremely mild clinical anomalies. The present data demonstrate that it should be current policy to test both parents of patients with del22q11.2, irrespective of the parental phenotype, in view of the fact that extremely mild clinical features can be detected in parents of deleted patients. This would provide accurate genetic counselling to del22q11.2 families, as relatively asymptomatic parents must be advised of the 50% risk of transmitting the deletion in a subsequent pregnancy. Various genetic and non-genetic factors, including modifier genes at separate loci, mosaicism, unstable mutations, allelic variations at the haploid locus, chance and environmental interaction, can be hypothesized to be involved in variable clinical expression, even in the same family.

Two novel mutations of the human delta7-sterol reductase (DHCR7) gene in children with Smith-Lemli-Opitz syndrome.

We analyzed seven unrelated children with the Smith-Lemli-Opitz syndrome (SLOS) for mutations in the delta7-sterol reductase gene by using SSCP and direct sequencing. We identified two novel mutations (V330M and R363C) in the DHCR7 gene. Reported mutations found in this study were T93M (3/14 alleles), E448K (2/14), and W151X, G244R, P329L, and R446Q (each found in one allele). The so-called common IVS8-1 G --> C was found in three alleles, confirming its relative rarity among Italian SLOS families. By using a scoring system, clinical severity did not seem to correlate with 7DHC levels and type of mutation. Expanding the spectrum of mutations in SLOS, our study does not support direct genotype-phenotype correlation.

Identification of a novel NOG gene mutation (P35S) in an Italian family with symphalangism.

Symphalangism (SYM or SYM1) is an autosomal dominant disorder characterized by multiple joint fusions. The disease is caused by mutations of the NOG gene, that maps to chromosome 17q22. So far, only six independent NOG mutations have been identified. We have analysed an Italian family in which father and son had bilateral symphalangism and detected a novel NOG mutation (P35S), originated in the father from a c.914C>T transition. A different mutation in the same codon (P35R) has been previously described. Comparison between different noggin gene hortologs shows that codon 35 is conserved. Therefore, this codon should play an important role in NOG gene function. This is the first mutation described for NOG after the initial report of NOG mutations being causative of SYM.

Complete transposition of the great arteries: patterns of congenital heart disease in familial precurrence.

BACKGROUND: Transposition of the great arteries (TGA) is considered to be associated only rarely with genetic syndromes and to have a low risk of precurrence among relatives of affected patients. Because most family studies have involved a relatively small number of patients and evaluated all types of TGA as a single group, we performed a large, prospective study investigating the precurrence of congenital heart disease in families of children with complete, nonsyndromic TGA. METHODS AND RESULTS: From January 1997 through December 2000, 370 patients with nonsyndromic, complete TGA were consecutively evaluated and enrolled in the study. The occurrence of cardiac and noncardiac anomalies among relatives of the probands was investigated. Relatives with congenital heart disease were found in 37 of 370 families (10%), including 5 of 37 families (13.5%) with more than one affected relative. TGA itself was the most common precurrent malformation: complete TGA occurred in 6 families and congenitally corrected TGA occurred in 5 families. Precurrence risks for congenital heart disease were calculated at 1.8% (8 of 436) for siblings, 0.5% (4 of 740) for parents, 0.5% (16 of 3261) for first cousins, 0.2% (4 of 2101) for uncles/aunts, and 0.06% (1 of 1480) for grandparents. CONCLUSIONS: The present study shows that TGA is not always sporadic in families. Precurrence of concordant cardiac defects within affected family members supports monogenic or oligogenic inheritance of TGA in certain kindreds. Moreover, the occurrence of complete TGA and congenitally corrected TGA among first-degree relatives in several different families strongly suggests an underlying pathogenetic link between these 2 malformations that has been previously unrecognized.

Coeliac disease in Williams syndrome.

BACKGROUND: Coeliac disease (CD) has been reported in several patients affected by chromosomal disorders, including Down syndrome (DS) and Turner syndrome (TS). CD has also been found in sporadic Williams syndrome (WS) patients. In this study, CD was evaluated in a consecutive series of patients with WS, in order to estimate if the prevalence of CD in WS patients is higher than in the general population. METHODS AND RESULTS: A consecutive series of 63 Italian patients with WS was studied by analysing the dosage of antigliadin antibodies (AGA) IgA and antiendomisium antibodies (AEA). In patients with positive AGA and AEA, small bowel biopsy was performed. The prevalence of CD in our WS population was compared with that estimated in a published series of 17 201 Italian students. Seven WS patients were found to be positive for AGA IgA and AEA. Six of them underwent small bowel biopsy, which invariably disclosed villous atrophy consistent with CD. The prevalence of CD in the present series of WS patients was 9.5% (6/63), compared to 0.54% (1/184) in the Italian students (p<0.001). CONCLUSION: The present results suggest that the prevalence of CD in WS is higher than in the general population and is comparable to that reported in DS and TS. AGA and AEA screening is recommended in patients with WS.

Ext-mutation analysis in Italian sporadic and hereditary osteochondromas.

Osteochondromas represent the largest group of benign tumors of bone. Multiple osteochondromatosis or hereditary multiple exostoses (EXT) is an autosomal dominant inherited disorder characterized by the presence of multiple benign cartilage-capped exostoses. EXT is genetically heterogeneous with at least 3 chromosomal loci: EXT1 (8q24.1), EXT2 (11p11-p13), and EXT3 (19p). In <5% of EXT patients, the inactivation of both copies of EXT alleles (LOH) is associated with malignant transformation. We have analyzed the EXT1 and EXT2 genes in 9 unrelated EXT families and in a patient with a sporadic osteochondroma, all originating from Italy. Four families show an EXT1 mutation, consisting of a small deletion in 3 of them and a small insertion in the 4th. All these mutations lead to premature termination of translation and thus a truncated EXT1 protein. Three families presented EXT2 mutations consisting of nucleotide substitutions leading to alterations of the third intron splice-site, to an amino acid substitution and to a nonsense mutation. All these mutations cosegregate with the disease phenotype. The sporadic osteochondroma patient carried a novel missense mutation in exon 11 of EXT2 gene, leading to an amino acid substitution. Seven of these mutations have never been described before. EXT2 missense mutations were also confirmed by amino acids conservation between human and mouse and by analysis of a healthy control population. In conclusion, our study provide further evidence that loss of function of the EXT1 or EXT2 gene is the main cause of EXT supporting the putative tumor-suppressor function of these genes.

Prevalence and clinical picture of celiac disease in italian down syndrome patients: a multicenter study.

BACKGROUND: A multicenter research study of Down syndrome patients was carried out to estimate the prevalence of celiac disease in patients with Down syndrome and to show clinical characteristics and laboratory data of Down syndrome patients. METHODS: The authors studied 1,202 Down syndrome patients. Fifty-five celiac disease patients (group 1) were compared with 55 immunoglobulin A antigliadin-positive antiendomysium antibodies-negative patients (group 2) and with 57 immunoglobulin A antigliadin-negative antiendomysium antibodies-negative patients (group 3). RESULTS: Celiac disease was diagnosed in 55 of 1,202 Down syndrome patients (4.6%). In group 1, weight and height percentiles were shifted to the left, whereas these parameters were normally distributed in groups 2 and 3. In celiac patients, diarrhea, vomiting, failure to thrive, anorexia, constipation, and abdominal distension were higher than in the other two groups. Low levels of hemoglobinemia, serum iron, and calcium were observed more frequently in group 1. The diagnosis of celiac disease was made after a mean period of 3.8 years from the initiation of symptoms. Sixty-nine percent of patients showed a classic presentation, 11% had atypical symptoms, and 20% had silent celiac disease. Autoimmune disorders were more frequent (30.9%) in group 1 than in the other two groups examined (15%; P < 0.05). CONCLUSIONS: This study reconfirms a high prevalence of celiac disease in Down syndrome. However, the diagnostic delay, the detection of atypical symptoms or silent form in one third of the cases, and the increased incidence of autoimmune disorders suggest the need for the screening of celiac disease in all Down syndrome patients.

Neurofibromatosis type 1 presenting with hand dystonia.

Neurofibromatosis type 1 is frequently associated with increased intensity T2-weighted magnetic resonance imaging (MRI) brain abnormalities, called "unidentified bright objects." Unidentified bright objects are generally held to be benign and tend to decrease in size during adulthood. We describe a case of neurofibromatosis type 1 with a similar thalamic and subthalamic MRI abnormality associated with contralateral hand dystonia. Over a 2-year follow-up, the lesions showed a reduction in size apparently correlated with a reduction in symptoms.

Opioid overdose in a patient using a fentanyl patch during treatment with a warming blanket.

IMPLICATIONS: This case describes the narcotic overdose associated with the use of a fentanyl transdermal patch in a patient being rewarmed with an external warming blanket during surgery. The clinical manifestation and the presumed pharmacokinetic mechanism responsible for the fentanyl overdose are discussed.

Pulmonary atresia with ventricular septal defect: prevalence of deletion 22q11 in the different anatomic patterns.

BACKGROUND: Pulmonary atresia with ventricular septal defect (PA-VSD) is one of the most common cardiac defects associated with DiGeorge syndrome. The pattern of the pulmonary circulation determines the complexity of this type of heart disease. The aim of this study was to establish the prevalence of DiGeorge syndrome with deletion 22q11 in patients with simple and complex PA-VSD. METHODS: Since 1993 we have studied 128 consecutive patients affected by PA-VSD. In 90 of our patients the PA-VSD was considered "simple" (group I), because it was not associated with any other cardiac defects. In the other 38 children the PA-VSD was considered "complex" (group II) owing to the presence of heterotaxia, tricuspid atresia, a double-inlet left ventricle, transposition of the great arteries and congenitally corrected transposition of the great arteries. RESULTS: In group I, 38 patients (42%) had genetic syndromes or major extracardiac anomalies; deletion 22q11 was detected in 31% of cases. Major aortopulmonary collateral arteries were present in 50% of group I patients and in 57% of those with deletion 22q11. In group II, 10 patients (26%) had genetic syndromes or major extracardiac anomalies but none had deletion 22q11 (p < 0.005); in no case was the presence of major aortopulmonary collateral arteries observed (p < 0.005). CONCLUSIONS: PA-VSD is an anatomically and morphogenetically heterogeneous disease: in the setting of DiGeorge syndrome or velocardiofacial syndrome, PA-VSD is associated with a peculiar cardiac pattern and is due to deletion 22, whereas in case of nonsyndromic PA-VSD or when this disease is associated with different syndromes or with other types of cardiac defects, it is due to other morphogenetic mechanisms.

Auxological evaluation in patients with DiGeorge/velocardiofacial syndrome (deletion 22q11.2 syndrome).

PURPOSE: Patients with microdeletion of chromosome 22q11.2 (del22q11) were studied, in order to evaluate auxological parameters and to correlate growth patterns with the presence of main clinical characteristics of the syndrome. METHODS: Between January 1995 and March 2000, auxological parameters (weight, height, head circumference, and bone age) of 73 patients with del22q11 were collected. Five subgroups of patients were distinguished: Group I (37 patients) included patients aged between 0.3 and 4 years, Group II (20 patients) included patients aged between 5 and 10 years, Group III (16 patients) included patients aged between 11 and 16.3 years. The presence or absence of some clinical features was correlated to growth patterns. RESULTS: Weight: in Group I, 5 of 37 (13.5%) patients were below the 3rd percentile, 29 of 37 (78.3%) were below the mean percentile, none was overweight; in Group II, 13 of 20 (65%) patients were between the 10th and the 50th percentiles; in Group III, weight corresponded to the 97th percentile in 5 of 16 (31.2%) patients, and in 2/16 (12.5%) adolescents, the weight measurements were even above the 97th percentile. Height: short stature was detected in 7 of 73 (9.6%) of the total patients; the patients with short stature were all < 10 years old; the height was within the normal age in all adolescent patients. Head circumference: it was below the 3rd percentile in 7 of 73 (9.6%), between the 3rd and the 25th percentiles in 36 of 73 (49.3%) patients, between the 25th and the 75th percentiles in 20 of 73 (27.3%) patients, and between the 75th and the 97th percentiles in 10 of 73 (13.7%) patients. Bone age: mean +/- SD bone age was -0.25 +/- 0.78 years. Comparisons: the only statistically significant correlation was that between the presence of feeding difficulties and underweight. CONCLUSION: Auxological parameters of children with del22q11 are characterized by: (1) weight deficiency in the first years of age, (2) weight normalization in the following years, (3) development of obesity in adolescence, (4) short stature in 10% of the patients, (5) normal height in adolescents, (6) slight delay in bone age in infancy, (7) microcephaly in 10% of the patients.

Anatomic patterns of conotruncal defects associated with deletion 22q11.

PURPOSE: Patients with cardiovascular malformations (CVMs) and deletion 22q11 from our series were studied in order to (1) analyze the association with dysmorphic features and noncardiac anomalies, (2) identify specific cardiac patterns and the distinctive association with additional CVMs. METHODS: From 1993 to 2000, 931 patients with CVM (95 with a clinical diagnosis of DiGeorge/velocardiofacial syndrome (DG/VCFS), 208 with different genetic syndromes, 628 without dysmorphic features) underwent accurate cardiac assessment, clinical and phenotypical examination, and screening for deletion 22q11 by fluorescence in situ hybridization (FISH). RESULTS: Deletion 22q11 was detected in 88 of the total patients, and in 87 of the 95 patients with a clinical diagnosis of DG/VCFS. Only one patient among the 628 without dysmorphic features had deletion 22q11. Conotruncal heart defects were the most common CVMs, often presenting in association with additional anomalies in four areas of the cardiovascular system: (1) the aortic arch can be right sided, cervical, double, and the subclavian artery can be aberrant, (2) the pulmonary arteries can present discontinuity, diffuse hypoplasia, discrete stenosis, defect of arborization and major aortopulmonary collateral arteries (MAPCA), (3) the infundibular septum can be malaligned, hypoplastic, or absent, (4) the semilunar valves can be bicuspid, severely dysplastic, insufficient, or stenotic. CONCLUSION: In subjects with deletion 22q11 CVM is virtually always associated with one or more noncardiac anomalies. Deletion 22q11 is exceptionally rare in children with nonsyndromic CVMs. Specific patterns of CVMs are observed in patients with deletion 22q11, including (1) anomalies of the aortic arch, (2) anomalies of the pulmonary arteries and of the pulmonary blood supply, (3) defects of the infundibular septum, (4) malformations of the semilunar valves. These additional CVMs may influence the surgical treatment of these patients.

Congenital heart defects in Kabuki syndrome.

Kabuki makeup (Niikawa-Kuroki) syndrome (KS) is characterized by distinct facial anomalies, mental retardation, congenital heart defect (CHD), and skeletal malformations. In the present study we analyze cardiac characteristics and differences in sex prevalence of specific CHDs in our series of patients with KS and review published reports from the literature. Between January 1992 and February 2000, 60 patients (37 males and 23 females) with KS underwent phenotypic and cardiac evaluations at our hospital. CHD was diagnosed in 35 (58%) of our patients. Aortic coarctation (COA) (23%), atrial septal defect (ASD) (20%), and ventricular septal defect (VSD) (17%) were the most frequent CHDs in our series and in previous reports from the literature. Male preponderance was noted in patients with COA. In conclusion, CHD is a cardinal feature of KS. There is an overlap between cardiac malformations of KS and those of Turner syndrome. Male preponderance in patients with KS and COA supports the hypothesis that genes located on the X chromosome may be involved in determining KS in some patients. The high prevalence of CHD prompts accurate re-examination of patients evaluated by pediatric cardiologists in order to identify mild and still unrecognized cases of KS.