De Novo Variants in RAB11B Cause Various Degrees of Global Developmental Delay and Intellectual Disability in Children

BACKGROUND

RAB11B was described previously once with a severe form of intellectual disability. We aim at validation and delineation of the role of RAB11B in neurodevelopmental disorders.

METHODS

We present seven novel individuals with disease-associated variants in RAB11B when compared with the six cases described in the literature. We performed a cross-sectional analysis to identify the clinical spectrum and the core phenotype. Additionally, structural effects of the variants were assessed by molecular modeling.

RESULTS

Seven distinct de novo missense variants were identified, three of them recurrent (p.(Gly21Arg), p.(Val22Met), and p.(Ala68Thr)). Molecular modeling suggests that those variants either affect the nucleotide binding (at amino acid positions 21, 22, 33, 68) or the interaction with effector molecules (at positions 72 and 75). Our data confirmed the main manifestations as neurodevelopmental disorder with intellectual disability (85%), muscular hypotonia (83%), structural brain anomalies (77%), and visual impairment (70%). Combined analysis indicates a genotype-phenotype correlation; variants impacting the nucleotide binding cause a severe phenotype with intellectual disability, and variants outside the binding pocket lead to a milder phenotype with epilepsy.

CONCLUSIONS

We confirm that disease-associated missense variants in RAB11B cause a neurodevelopmental disorder and suggest a genotype-phenotype correlation based on the impact on nucleotide binding functionality of RAB11B.

De novo variants in ATP2B1 lead to neurodevelopmental delay

Calcium (Ca²⁺) is a universal second messenger involved in synaptogenesis and cell survival; consequently, its regulation is important for neurons. ATPase plasma membrane Ca²⁺ transporting 1 (ATP2B1) belongs to the family of ATP-driven calmodulin-dependent Ca²⁺ pumps that participate in the regulation of intracellular free Ca²⁺. Here, we clinically describe a cohort of 12 unrelated individuals with variants in ATP2B1 and an overlapping phenotype of mild to moderate global development delay. Additional common symptoms include autism, seizures, and distal limb abnormalities. Nine probands harbor missense variants, seven of which were in specific functional domains, and three individuals have nonsense variants. 3D structural protein modeling suggested that the variants have a destabilizing effect on the protein. We performed Ca²⁺ imaging after introducing all nine missense variants in transfected HEK293 cells and showed that all variants lead to a significant decrease in Ca²⁺ export capacity compared with the wild-type construct, thus proving their pathogenicity. Furthermore, we observed for the same variant set an incorrect intracellular localization of ATP2B1. The genetic findings and the overlapping phenotype of the probands as well as the functional analyses imply that de novo variants in ATP2B1 lead to a monogenic form of neurodevelopmental disorder.

Novel insights into PORCN mutations, associated phenotypes and pathophysiological aspects

BACKGROUND

Goltz syndrome (GS) is a X-linked disorder defined by defects of mesodermal- and ectodermal-derived structures and caused by PORCN mutations. Features include striated skin-pigmentation, ocular and skeletal malformations and supernumerary or hypoplastic nipples. Generally, GS is associated with in utero lethality in males and most of the reported male patients show mosaicism (only three non-mosaic surviving males have been described so far). Also, precise descriptions of neurological deficits in GS are rare and less severe phenotypes might not only be caused by mosaicism but also by less pathogenic mutations suggesting the need of a molecular genetics and functional work-up of these rare variants.

RESULTS

We report two cases: one girl suffering from typical skin and skeletal abnormalities, developmental delay, microcephaly, thin corpus callosum, periventricular gliosis and drug-resistant epilepsy caused by a PORCN nonsense-mutation (c.283C > T, p.Arg95Ter). Presence of these combined neurological features indicates that CNS-vulnerability might be a guiding symptom in the diagnosis of GS patients. The other patient is a boy with a supernumerary nipple and skeletal anomalies but also, developmental delay, microcephaly, cerebral atrophy with delayed myelination and drug-resistant epilepsy as predominant features. Skin abnormalities were not observed. Genotyping revealed a novel PORCN missense-mutation (c.847G > C, p.Asp283His) absent in the Genome Aggregation Database (gnomAD) but also identified in his asymptomatic mother. Given that non-random X-chromosome inactivation was excluded in the mother, fibroblasts of the index had been analyzed for PORCN protein-abundance and -distribution, vulnerability against additional ER-stress burden as well as for protein secretion revealing changes.

CONCLUSIONS

Our combined findings may suggest incomplete penetrance for the p.Asp283His variant and provide novel insights into the molecular etiology of GS by adding impaired ER-function and altered protein secretion to the list of pathophysiological processes resulting in the clinical manifestation of GS.

Three Individuals with PURA Syndrome in a Cohort of Patients with Neuromuscular Disease

Pur-α protein (PURA) syndrome manifests in early childhood with core features such as neurodevelopmental and speech delay, feeding difficulties, epilepsy, and hypotonia at birth. We identified three cases with PURA syndrome in a cohort of patients with unexplained muscular weakness, presenting with a predominantly neuromuscular and ataxic phenotype. We further characterize the clinical presentation of PURA syndrome including myopathic facies and muscular weakness as the main clinical symptoms in combination with elevated serum creatine kinase levels. Furthermore, we report two novel variants located in the conservative domains PUR-I and PUR-II. For the first time, we present the muscle biopsies of PURA syndrome patients, showing myopathic changes, fiber size variability, and fast fiber atrophy as the key features. PURA syndrome should be taken into consideration as a differential diagnosis in pediatric patients with unexplained muscle weakness.

Practice recommendations for neurovascular ultrasound investigations of acute stroke patients in the setting of the COVID-19 pandemic: an expert consensus from the European Society of Neurosonology and Cerebral Hemodynamics

Background and purpose

Patients with acute ischemic stroke are at high‐risk for contracting COVID‐19 infection. Additionally, healthcare professionals including neurovascular ultrasound providers are also at risk of being infected by SARS‐CoV‐2 virus. Yet, preparedness to continue to guarantee hyperacute treatment is vital for patients outcome. In light of this situation, the European Society of Neurosonology and Cerebral Hemodynamic (ESNCH) appointed a task force to provide consensus recommendations for the performance of neurovascular ultrasound investigations in acute ischemic stroke during the COVID‐19 pandemic with the aim of protecting both patients and ultrasound providers.

Methods

The “ultrasound in acute stroke working group” of the ESNCH examined literature articles and reviews using the following key words: “corona virus” or “COVID‐19” or “SARS‐CoV‐2 virus”, and “acute stroke” or “cerebrovascular disease”, and “ultrasound”. Thereafter, a thorough discussion was conducted with the “education and guidelines working group” of the ESNCH.

Results

We propose rapid up‐to‐date recommendations for healthcare personnel involved in the pre‐hospital and intra‐hospital assessment of stroke patients, with a particular attention to neurovascular ultrasound performance.

Conclusion

The ESNCH provides a guidance summary for the performance of neurovascular ultrasound investigations in acute ischemic stroke in the time of COVID‐19.

Male infant with paternal uniparental diploidy mosaicism and a 46,XX/46,XY karyotype

A male patient with mosaic paternal uniparental diploidy (PUD) is presented. After birth, the patient presented with hypoglycemia, hemihypertrophy, umbilical hernia, and hepatomegaly. Afterward pancreatic hypertrophy, liver hemangiomas, and cysts were detected sonographically. At the age of 3.5 months, hepatoblastoma was diagnosed. To investigate suspected Beckwith-Wiedemann syndrome (BWS), extensive genetic analyses were performed using DNA from chorionic villus sampling, amniocentesis, and peripheral blood lymphocytes (chromosome analysis, methylation-specific multiplex ligation-dependent probe amplification assays, microsatellite analyses, and single nucleotide polymorphism array analysis). These analyses led to the detection of mosaic PUD. In peripheral blood lymphocytes, a male cell line (46,XY[27]/46,XX[5]) predominated, suggesting a mixture of uniparental isodisomy and heterodisomy. The genetic analyses suggest that the mosaic PUD status was attributable to fertilization of an oocyte by two sperms, with subsequent triploidy rescue giving rise to haploidy, which in turn was rescued. Notably, in the majority of the 28 mosaic PUD patients reported to date, BWS was initially suspected. Mosaic PUD status is associated with a higher risk for a broad range of malignant and benign tumors than in BWS. As tumors can also occur after childhood surveillance into adolescence is indicated. Mosaic PUD must therefore be considered in patients with suspected BWS.

Genomic variation among populations of threatened coral: Acropora cervicornis

Background

Acropora cervicornis, a threatened, keystone reef-building coral has undergone severe declines (>90 %) throughout the Caribbean. These declines could reduce genetic variation and thus hamper the species’ ability to adapt. Active restoration strategies are a common conservation approach to mitigate species' declines and require genetic data on surviving populations to efficiently respond to declines while maintaining the genetic diversity needed to adapt to changing conditions. To evaluate active restoration strategies for the staghorn coral, the genetic diversity of A. cervicornis within and among populations was assessed in 77 individuals collected from 68 locations along the Florida Reef Tract (FRT) and in the Dominican Republic.

Results

Genotyping by Sequencing (GBS) identified 4,764 single nucleotide polymorphisms (SNPs). Pairwise nucleotide differences (π) within a population are large (~37 %) and similar to π across all individuals. This high level of genetic diversity along the FRT is similar to the diversity within a small, isolated reef. Much of the genetic diversity (>90 %) exists within a population, yet GBS analysis shows significant variation along the FRT, including 300 SNPs with significant F_ST values and significant divergence relative to distance. There are also significant differences in SNP allele frequencies over small spatial scales, exemplified by the large F_ST values among corals collected within Miami-Dade county.

Conclusions

Large standing diversity was found within each population even after recent declines in abundance, including significant, potentially adaptive divergence over short distances. The data here inform conservation and management actions by uncovering population structure and high levels of diversity maintained within coral collections among sites previously shown to have little genetic divergence. More broadly, this approach demonstrates the power of GBS to resolve differences among individuals and identify subtle genetic structure, informing conservation goals with evolutionary implications.

Heterozygous FGF8 mutations in patients presenting cryptorchidism and multiple VATER/VACTERL features without limb anomalies

BACKGROUND

The acronym VATER/VACTERL association describes the combination of at least three of the following cardinal features: vertebral defects, anorectal malformations, cardiac defects, tracheoesophageal fistula with or without esophageal atresia, renal malformations, and limb defects. Although fibroblast growth factor-8 (FGF8) mutations have mainly found in patients with Kallmann syndrome, mice with a hypomorphic Fgf8 allele or complete gene invalidation display, aside from gonadotropin-releasing hormone deficiency, parts or even the entire spectrum of human VATER/VACTERL association.

METHODS

We performed FGF8 gene analysis in 49 patients with VATER/VACTERL association and 27 patients presenting with a VATER/VACTERL-like phenotype (two cardinal features).

RESULTS

We identified two heterozygous FGF8 mutations in patients displaying either VATER/VACTERL association (p.Gly29_Arg34dup) or a VATER/VACTERL-like phenotype (p.Pro26Leu) without limb anomalies. Whereas the duplication mutation has not been reported before, p.Pro26Leu was once observed in a Kallmann syndrome patient. Both our patients had additional bilateral cryptorchidism, a key phenotypic feature in males with FGF8 associated Kallmann syndrome. Each mutation was paternally inherited. Besides delayed puberty in both and additional unilateral cryptorchidism in one of the fathers, they were otherwise healthy. Serum hormone levels downstream the gonadotropin-releasing hormone in both patients and their fathers were within normal range.

CONCLUSION

Our results suggest FGF8 mutations to contribute to the formation of the VATER/VACTERL association. Further studies are needed to support this observation.

Genome-wide association study and mouse expression data identify a highly conserved 32 kb intergenic region between WNT3 and WNT9b as possible susceptibility locus for isolated classic exstrophy of the bladder

Bladder exstrophy-epispadias complex (BEEC), the severe end of the urorectal malformation spectrum, has a profound impact on continence as well as sexual and renal functions. It is widely accepted that for the majority of cases the genetic basis appears to be multifactorial. Here, we report the first study which utilizes genome-wide association methods to analyze a cohort comprising patients presenting the most common BEEC form, classic bladder exstrophy (CBE), to identify common variation associated with risk for isolated CBE. We employed discovery and follow-up samples comprising 218 cases/865 controls and 78 trios in total, all of European descent. Our discovery sample identified a marker near SALL1, showing genome-wide significant association with CBE. However, analyses performed on follow-up samples did not add further support to these findings. We were also able to identify an association with CBE across our study samples (discovery: P = 8.88 × 10(-5); follow-up: P = 0.0025; combined: 1.09 × 10(-6)) in a highly conserved 32 kb intergenic region containing regulatory elements between WNT3 and WNT9B. Subsequent analyses in mice revealed expression for both genes in the genital region during stages relevant to the development of CBE in humans. Unfortunately, we were not able to replicate the suggestive signal for WNT3 and WNT9B in a sample that was enriched for non-CBE BEEC cases (P = 0.51). Our suggestive findings support the hypothesis that larger samples are warranted to identify association of common variation with CBE.

Second study on the recurrence risk of isolated esophageal atresia with or without trachea-esophageal fistula among first-degree relatives: no evidence for increased risk of recurrence of EA/TEF or for malformations of the VATER/VACTERL association spectrum

BACKGROUND

Esophageal atresia with/without trachea-esophageal fistula (EA/TEF) denotes a spectrum of severe congenital malformations. The aim of this systematic study was to determine both the recurrence risk for EA/TEF, and the risk for malformations of the VATER/VACTERL association spectrum, in first-degree relatives of patients with isolated EA/TEF.

METHODS

A total of 108 unrelated patients with isolated EA/TEF were included. These individuals had 410 first-degree relatives including 194 siblings. The presence of EA/TEF and malformations of the VATER/VACTERL association spectrum in relatives was systematically assessed. Data from the EUROCAT network were used for comparison.

RESULTS

None of the first-degree relatives displayed any form of EA/TEF. In two families, a first-degree relative presented with malformations from the VATER/VACTERL association spectrum. However, no increase in the risk for malformations of the VATER/VACTERL association spectrum was found compared with the control cohort (p = 0.87). In three families, one more distantly related relative presented with EA/TEF.

CONCLUSION

In contrast to previous studies, our results suggest a very low recurrence risk for isolated EA/TEF and/or for malformations of the VATER/VACTERL association spectrum among first-degree relatives.

De novo 13q deletions in two patients with mild anorectal malformations as part of VATER/VACTERL and VATER/VACTERL-like association and analysis of EFNB2 in patients with anorectal malformations

Anorectal malformations (ARMs) comprise a broad spectrum of conditions ranging from mild anal anomalies to complex cloacal malformations. In 40-50% of cases, ARM occurs within the context of defined genetic syndromes or complex multiple congenital anomalies, such as VATER/VACTERL (vertebral defects [V], ARMs [A], cardiac defects [C], tracheoesophageal fistula with or without esophageal atresia [TE], renal malformations [R], and limb defects [L]) association. Here, we report the identification of deletions at chromosome 13q using single nucleotide polymorphism-based array analysis in two patients with mild ARM as part of VATER/VACTERL and VATER/VACTERL-like associations. Both deletions overlap the previously defined critical region for ARM. Heterozygous Efnb2 murine knockout models presenting with mild ARM suggest EFNB2 as an excellent candidate gene in this region. Our patients showed a mild ARM phenotype, closely resembling that of the mouse. We performed a comprehensive mutation analysis of the EFNB2 gene in 331 patients with isolated ARM, or ARM as part of VATER/VACTERL or VATER/VACTERL-like associations. However, we did not identify any disease-causing mutations. Given the convincing argument for EFNB2 as a candidate gene for ARM, analyses of larger samples and screening of functionally relevant non-coding regions of EFNB2 are warranted. In conclusion, our report underlines the association of chromosome 13q deletions with ARM, suggesting that routine molecular diagnostic workup should include the search for these deletions. Despite the negative results of our mutation screening, we still consider EFNB2 an excellent candidate gene for contributing to the development of ARM in humans.

Evidence for a host role in thermotolerance divergence between populations of the mustard hill coral (Porites astreoides) from different reef environments

Studying the mechanisms that enable coral populations to inhabit spatially varying thermal environments can help evaluate how they will respond in time to the effects of global climate change and elucidate the evolutionary forces that enable or constrain adaptation. Inshore reefs in the Florida Keys experience higher temperatures than offshore reefs for prolonged periods during the summer. We conducted a common garden experiment with heat stress as our selective agent to test for local thermal adaptation in corals from inshore and offshore reefs. We show that inshore corals are more tolerant of a 6-week temperature stress than offshore corals. Compared with inshore corals, offshore corals in the 31 °C treatment showed significantly elevated bleaching levels concomitant with a tendency towards reduced growth. In addition, dinoflagellate symbionts (Symbiodinium sp.) of offshore corals exhibited reduced photosynthetic efficiency. We did not detect differences in the frequencies of major (>5%) haplotypes comprising Symbiodinium communities hosted by inshore and offshore corals, nor did we observe frequency shifts ('shuffling') in response to thermal stress. Instead, coral host populations showed significant genetic divergence between inshore and offshore reefs, suggesting that in Porites astreoides, the coral host might play a prominent role in holobiont thermotolerance. Our results demonstrate that coral populations inhabiting reefs <10-km apart can exhibit substantial differences in their physiological response to thermal stress, which could impact their population dynamics under climate change.

De novo microduplications at 1q41, 2q37.3, and 8q24.3 in patients with VATER/VACTERL association

The acronym VATER/VACTERL association describes the combination of at least three of the following congenital anomalies: vertebral defects (V), anorectal malformations (A), cardiac defects (C), tracheoesophageal fistula with or without esophageal atresia (TE), renal malformations (R), and limb defects (L). We aimed to identify highly penetrant de novo copy number variations (CNVs) that contribute to VATER/VACTERL association. Array-based molecular karyotyping was performed in a cohort of 41 patients with VATER/VACTERL association and 6 patients with VATER/VACTERL-like phenotype including all of the patients' parents. Three de novo CNVs were identified involving chromosomal regions 1q41, 2q37.3, and 8q24.3 comprising one (SPATA17), two (CAPN10, GPR35), and three (EPPK1, PLEC, PARP10) genes, respectively. Pre-existing data from the literature prompted us to choose GPR35 and EPPK1 for mouse expression studies. Based on these studies, we prioritized GPR35 for sequencing analysis in an extended cohort of 192 patients with VATER/VACTERL association and VATER/VACTERL-like phenotype. Although no disease-causing mutation was identified, our mouse expression studies suggest GPR35 to be involved in the development of the VATER/VACTERL phenotype. Follow-up of GPR35 and the other genes comprising the identified duplications is warranted.

Isolated bladder exstrophy associated with a de novo 0.9 Mb microduplication on chromosome 19p13.12

BACKGROUND

The exstrophy-epispadias complex (BEEC) is a urogenital birth defect of varying severity. The causes of the BEEC are likely to be heterogeneous, with individual environmental or genetic risk factors still being largely unknown. In this study, we aimed to identify de novo causative copy number variations (CNVs) that contribute to the BEEC.

METHODS

Array-based molecular karyotyping was performed to screen 110 individuals with BEEC. Promising CNVs were tested for de novo occurrence by investigating parental DNAs. Genes located in regions of rearrangements were prioritized through expression analysis in mice to be sequenced in the complete cohort, to identify high-penetrance mutations involving small sequence changes.

RESULTS

A de novo 0.9 Mb microduplication involving chromosomal region 19p13.12 was identified in a single patient. This region harbors 20 validated RefSeq genes, and in situ hybridization data showed specific expression of the Wiz gene in regions surrounding the cloaca and the rectum between GD 9.5 and 13.5. Sanger sequencing of the complete cohort did not reveal any pathogenic alterations affecting the coding region of WIZ.

CONCLUSIONS

The present study suggests chromosomal region 19p13.12 as possibly involved in the development of CBE, but further studies are needed to prove a causal relation. The spatiotemporal expression patterns determined for the genes encompassed suggest a role for Wiz in the development of the phenotype. Our mutation screening, however, could not confirm that WIZ mutations are a frequent cause of CBE, although rare mutations might be detectable in larger patient samples. 19p13.12, microduplication, bladder exstrophy-epispadias complex, array-based molecular karyotyping, in situ hybridization analysis, copy number variations, WIZ gene.

Practice of dilatation after surgical correction in anorectal malformations

BACKGROUND

In order to prevent stricture of the neoanus after surgical correction, regular dilatation is recommended. There is a lack of knowledge about the performance of anal dilatation and the occurrence of pain. The aim of our investigation was to describe the practice of dilatation and to identify possible risk factors for painful procedures.

METHODS

Congenital Uro-Rectal Malformations Network is a German interdisciplinary multicenter research network. With standard questionnaires, physicians interviewed 243 patients and/or their parents at home, additional 103 patients born since 2009 were assessed through their treating physicians.

RESULTS

In total, 88 % of the patients received dilatations. Treatment lasted for 7 months in median (range 1-156 months), until the age of 13 months (range 1-171 months). In 69 % painful dilatation was reported; without a significant differences in age or gender. In 32 % bleeding was reported. In 30 % at least one dilatation was performed under general anesthesia. In 11 % some kind of analgesia was used. Type of fistula, dilatations lasting longer than 10 months and Hegar size above 15 were relevant factors for experience of pain. There were about 16 % postoperative strictures of the neoanus, without reported differences in dilatation procedures; but there was a relation to type of malformation.

CONCLUSION

Considering the high number of painful treatments, predictors for painful dilatations should be further clarified through standardized documentation and prospective evaluation in order to improve follow-up.

Assisted reproductive techniques and the risk of anorectal malformations: a German case-control study

BACKGROUND

The use of assisted reproductive techniques (ART) for treatment of infertility is increasing rapidly worldwide. However, various health effects have been reported including a higher risk of congenital malformations. Therefore, we assessed the risk of anorectal malformations (ARM) after in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

METHODS

Data of the German Network for Congenital Uro-REctal malformations (CURE-Net) were compared to nationwide data of the German IVF register and the Federal Statistical Office (DESTATIS). Odds ratios (95% confidence intervals) were determined to quantify associations using multivariable logistic regression accounting for potential confounding or interaction by plurality of births.

RESULTS

In total, 295 ARM patients born between 1997 and 2011 in Germany, who were recruited through participating pediatric surgeries from all over Germany and the German self-help organisation SoMA, were included. Controls were all German live-births (n = 10,069,986) born between 1997 and 2010. Overall, 30 cases (10%) and 129,982 controls (1%) were born after IVF or ICSI, which translates to an odds ratio (95% confidence interval) of 8.7 (5.9-12.6) between ART and ARM in bivariate analyses. Separate analyses showed a significantly increased risk for ARM after IVF (OR, 10.9; 95% CI, 6.2-19.0; P < 0.0001) as well as after ICSI (OR, 7.5; 95% CI, 4.6-12.2; P < 0.0001). Furthermore, separate analyses of patients with isolated ARM, ARM with associated anomalies and those with a VATER/VACTERL association showed strong associations with ART (ORs 4.9, 11.9 and 7.9, respectively). After stratification for plurality of birth, the corresponding odds ratios (95% confidence intervals) were 7.7 (4.6-12.7) for singletons and 4.9 (2.4-10.1) for multiple births.

CONCLUSIONS

There is a strongly increased risk for ARM among children born after ART. Elevations of risk were seen after both IVF and ICSI. Further, separate analyses of patients with isolated ARM, ARM with associated anomalies and those with a VATER/VACTERL association showed increased risks in each group. An increased risk of ARM was also seen among both singletons and multiple births.

Involvement of the WNT and FGF signaling pathways in non-isolated anorectal malformations: sequencing analysis of WNT3A, WNT5A, WNT11, DACT1, FGF10, FGFR2 and the T gene

Anorectal malformations (ARMs) comprise a broad spectrum of anomalies, including anal atresia, congenital anal fistula and persistence of the cloaca. Research suggests that genetic factors play an important role in ARM development. However, few genetic variants have been identified. Embryogenesis is orchestrated by crosstalk of the wingless-type MMTV integration site family (WNT) and fibroblast growth factor (FGF) signaling pathways in a process that involves several intracellular cascades. Studies in mice have implicated several genes from these pathways in the etiology of ARMs. We performed sequencing analysis of seven of these previously reported genes in 78 patients with ARMs occurring within the context of at least one additional congenital anomaly. No associations were identified with variants in WNT3A, WNT5A, WNT11, DACT1, FGF10 or the T gene. In the FGFR2 gene, three novel heterozygous nucleotide substitutions were identified. Further investigations, including the study of family members, revealed that these variants were not causally related to the phenotype in the present ARM cohort. Mutations in the seven investigated genes may nonetheless be a cause of ARMs in rare cases. However, further studies should consider genes encoding other proteins in the WNT/FGF signaling pathways as possible candidates.

Unexpected results of a nationwide, treatment-independent assessment of fecal incontinence in patients with anorectal anomalies

PURPOSE

To determine the anorectal function in patients with anorectal malformations (ARM) in order to facilitate patient counseling and follow-up.

METHODS

Data were collected by the German network for urorectal malformations (CURE-Net) according to the International Krickenbeck consensus. Questionnaires on bowel function and a defecation protocol were completed by the families/patients. The clinical findings were assessed from the patients' clinical records.

RESULTS

Two hundred and ninety-seven patients with ARM were assessed, 175 patients gave complete data on continence, 52 of them were excluded due to mental retardation, age, and earlier type of pullthrough. Complete continence was found in 27 %, perineal fistula in 40 %, rectourethral/vesical in 10 %, vestibular in 24 %, cloaca in 0 %. Krickenbeck grade 1 soiling: 42 %, grade 2 and 3: 31 %. Forty-nine percent of the incontinent patients practiced bowel management, reaching continence in 19 %. The statement of constipation (67 %) was validated with the last clinical findings, showing coprostasis in 46 %, "Not suffering constipation" was confirmed in 61 % and falsified in 29 %.

CONCLUSION

ARM patients in Germany, as assessed by independent researchers, show a high rate of fecal incontinence and insufficiently treated constipation. Parents should be counseled accordingly and motivated to engage in consequent follow-up. Intensified efforts in the conservative treatment of constipation and fecal incontinence are crucial to improvement.

Familial occurrence of the VATER/VACTERL association

The acronym VATER/VACTERL association is used to describe the non-random co-occurrence of vertebral defects (V), anorectal malformations (A), cardiac defects (C), tracheo-esophageal fistula with or without esophageal atresia (TE), renal malformations (R), and limb defects (L). We report a familial case of VATER/VACTERL association in which both the index case and her maternal uncle displayed four major component features of the disorder. A systematic literature search identified 12 previously described familial cases. However, on comparison, both members fulfilled the diagnostic criteria for VATER/VACTERL association only in one instance, and ours is the second such report. Although, a SNP array-based analysis identified no causal genomic alteration, the findings in the present family suggest that genetic factors are implicated in the development of the disorder.

Nine new twin pairs with esophageal atresia: a review of the literature and performance of a twin study of the disorder

BACKGROUND

Isolated esophageal atresia (EA) is a rare congenital malformation whose etiology remains largely unknown. Nine twin pairs with EA were identified from our clinical service, prompting the performance of a systematic review of the literature and the first reported twin study of isolated EA.

METHODS

A total of 330 twin pairs with EA were identified from the literature. The zygosity, concordance, and malformation (isolated vs. nonisolated) status of all 339 twin pairs were evaluated. A total of 72 twin pairs (4 of 9 / 68 of 330) fulfilled the criteria for inclusion in a classic twin study of isolated EA.

RESULTS

The pairwise concordance rates were 50% (95% confidence interval [CI], 34-66%) for monozygous (MZ) twin pairs and 26% (95% CI, 15-42%) for dizygous (DZ) twin pairs (p = 0.033). The probandwise concordance rates were 67% (95% CI, 53-78%) for MZ twin pairs and 42% (95% CI, 29-56%) for DZ twin pairs (p = 0.011). The MZ/DZ ratios were 1.9 for pairwise analysis and 1.6 for probandwise analysis. The familial risk ratios for MZ and DZ twin pairs were 1700 and 900, respectively.

CONCLUSION

The observation of higher concordance rates for MZ compared to DZ twin pairs indicates that genetic factors contribute to isolated EA.

Phenotype severity in the bladder exstrophy-epispadias complex: analysis of genetic and nongenetic contributing factors in 441 families from North America and Europe

OBJECTIVE

To identify genetic and nongenetic risk factors that contribute to the severity of the bladder exstrophy-epispadias complex (BEEC).

STUDY DESIGN

Patients with BEEC from North America (n = 167) and Europe (n = 274) were included. The following data were collected: associated anomalies, parental age at conception, mode of conception, periconceptional folic acid supplementation, maternal risk factors during pregnancy, and environmental risk factors. The patients were divided into 3 subgroups according to phenotype severity: (i) mild, epispadias (n = 43); (ii) intermediate, classic bladder exstrophy (n = 366); and (iii) severe, cloacal exstrophy (n = 31). These subgroups then were compared with identify factors that contribute to phenotype severity.

RESULTS

Males were overrepresented in all subgroups. A relatively high prevalence of cleft lip, with or without cleft palate, was observed. Maternal smoking and medical radiation during the first trimester were associated with the severe cloacal exstrophy phenotype. Compliance with periconceptional folic acid supplementation was associated with the mildest phenotype (epispadias).

CONCLUSIONS

Periconceptional folic acid supplementation appears to prevent the development of the severe phenotype of BEEC.

De novo partial trisomy 18p and partial monosomy 18q in a patient with anorectal malformation

Anorectal malformations (ARM) encompass a broad clinical spectrum which ranges from mild anal stenosis to severe anorectal anomalies such as complex cloacal malformations. The overall incidence of ARM is around 1 in every 2,500 live births. Although causative genes for a few syndromic forms have been identified, the molecular genetic background of most ARM remains unknown. The present report describes a patient with a de novo 13.2-Mb deletion of chromosome 18q22.3-qter and a 2.2-Mb de novo duplication of chromosomal region 18pter-p11.32 located at the telomeric end of chromosome 18q. The patient presented with ARM and the typical features of 18q- syndrome (De-Grouchy syndrome). The combination of a partial duplication of the short arm and a partial deletion of the long arm of chromosome 18 has been described in 16 previous cases. However, this is the first report of an association between this complex chromosomal rearrangement and ARM.

Autosomal-dominant non-syndromic anal atresia: sequencing of candidate genes, array-based molecular karyotyping, and review of the literature

INTRODUCTION

Anorectal malformations (ARM) range from mild anal to severe anorectal anomalies. Approximately 50% are estimated to be non-syndromic with multiple familial cases reported that suggest underlying genetic factors. These, however, still await identification.

MATERIALS AND METHODS

We report a familial case of non-syndromic ARM with a mother and her two children being affected. Mother and daughter had mild ARM that had only been diagnosed after the index patient was born with a more severe form and ultrashort Hirschsprung's disease. To reveal the genetic cause in our family genome-wide array analysis was carried out to ascertain microaberrations characterized by loss or gain of genomic material. In addition, sequence analysis of four major Hirschsprung's disease genes (RET, EDNRB, EDN3, and GDNF) and the HLXB9 gene was performed to identify a mutation common to all three family members; however, these analyses did not reveal any causal genetic alteration. To demonstrate the frequency of familial non-syndromic cases, we performed a literature search revealing 59 families with at least two affected members. Sufficient description of ARM phenotype and affection status of relatives to surely classify them as familial non-syndromic forms was given for 22 families.

CONCLUSION

The present family suggests that mild ARM may be overlooked in patients with non-specific clinical symptoms and that the incidence of ARM may thus be higher than previously estimated. With the new possibilities of whole exome sequencing, even small families hold the possibility to identify causal defects.

Osteoarthritis - a role for weight management in rheumatology practice: an update

Osteoarthritis (OA) and obesity are related diseases, which occur in a large proportion of the population. Epidemiological evidence show that weight is of great importance for the development of OA in the knee, and to some extent also in hip and finger joints. Once acquired, the OA contributes to further weight problems by decreasing the daily activity level. Weight loss will be beneficial for the knee and experimental data point at a highly significant effect on knee function and recent results even point at a positive effect on the cartilage of the knee joint. Recommending patients with a combination of knee OA and obesity to lose at least 5% body weight, and aim for 10% is predicted to correspond to 26% improvement in physical function. A programme for this weight loss has been tested with good results applying an initial formula diet with maintenance therapy in groups during follow-up.

Evidence for linkage of the bladder exstrophy-epispadias complex on chromosome 4q31.21-22 and 19q13.31-41 from a consanguineous Iranian family

BACKGROUND

The bladder exstrophy-epispadias complex (BEEC) is a spectrum of anomalies involving the abdominal wall, pelvis, urinary tract, genitalia, and, occasionally, the spine and anus. Although BEEC typically occurs sporadically, families with two or more affected members have been reported. The present authors previously conducted a genome-wide linkage analysis in two multiply affected (multiplex) families (one of German and one of Spanish origin), which revealed several chromosomal regions compatible with linkage. In the present study, genome-wide linkage analysis was performed in a recently reported consanguineous Iranian multiplex family with an affected sibling pair: a female with epispadias and a male with classic exstrophy of the bladder.

METHODS

The Affymetrix 250K Sty chip (238,304 single nucleotide polymorphisms) was used to genotype the parents and four children, including the two affected siblings. Parametric and nonparametric linkage analyses were performed.

RESULTS

Parametric linkage analysis under a recessive model with complete penetrance identified seven loci with LOD scores >1.6 (1p33, 4q31.21-22, 9q22.33, 12q13.13-2, 13q12.12-13, 18q23, and 19q13.31-41). These results were supported by nonparametric linkage analysis. Haplotype analysis showed that the affected individuals were homozygous identical by descent for all seven regions. Two of these regions overlapped with regions observed previously in the Spanish family -one on chromosome 4q31.21-22, and the other on chromosome 19q13.31-41.

CONCLUSION

These results suggest that chromosomal regions 4q31.21-22 and 19q13.31-41 are likely to harbor genes for an autosomal recessive form of BEEC.

Research perspectives in the etiology of congenital anorectal malformations using data of the International Consortium on Anorectal Malformations: evidence for risk factors across different populations

PURPOSE

The recently established International Consortium on Anorectal Malformations aims to identify genetic and environmental risk factors in the etiology of syndromic and nonsyndromic anorectal malformations (ARM) by promoting collaboration through data sharing and combined research activities.

METHODS

The consortium attempts to recruit at least 1,000 ARM cases. DNA samples are collected from case-parent triads to identify genetic factors involved in ARM. Several genetic techniques will be applied, including SNP arrays, gene and whole exome sequencing, and a genome-wide association study. Questionnaires inquiring about circumstances before and during pregnancy will be used to obtain environmental risk factor data.

RESULTS

Currently, 701 ARM cases have been recruited throughout Europe. Clinical data are available from all cases, and DNA samples and questionnaire data mainly from the Dutch and German cases. Preliminary analyses on environmental risk factors in the Dutch and German cohort found associations between ARM and family history of ARM, fever during first trimester of pregnancy and maternal job exposure to cleaning agents and solvents.

CONCLUSION

First results show that both genetic and environmental factors may contribute to the multifactorial etiology of ARM. The International Consortium on Anorectal Malformations will provide possibilities to study and detect important genes and environmental risk factors for ARM, ultimately resulting in better genetic counseling, improved therapies, and primary prevention.

Embryonic expression of the cysteine rich protein 61 (CYR61) gene: A candidate for the development of human epispadias

BACKGROUND

Isolated epispadias is the mildest phenotype of the exstrophy-epispadias complex, a urogenital birth defect of variable severity. The androgen receptor antagonist flutamide (FLU) is known to cause malformations in the rat genital and reproductive tract, and single-dose prenatal FLU exposure can induce epispadias in rat offspring. The Cyr61 gene exhibited the highest response to FLU in rat fetal testis, and we suggested it a promising candidate gene for epispadias in humans, because its protein product promotes proliferation, migration, and adhesion of endothelial cells and fibroblasts.

METHODS

We used whole mount in situ analysis in mice to investigate ventrocaudal expression of the Cyr61 transcript at gestational days 9.5 to 11.5, which is the equivalent of human gestational weeks 4 to 6 (postulated time of epispadias organogenesis in humans). We also performed mutational analysis of the CYR61 gene in 11 patients with isolated epispadias and in additional eight patients with the related classic bladder exstrophy phenotype.

RESULTS

Expression of Cyr61 was detected in endothelial cells of vessels surrounding the cloaca and the umbilical cord on gestational days 10 and 11.5. The mutation screening, however, revealed no alterations in the coding region of human CYR61.

CONCLUSIONS

The spatiotemporal expression pattern observed suggests a role for Cyr61 in the development of the external genitalia. Our mutation screening study, however, could not confirm that mutations affecting the CYR61 gene are a frequent cause of epispadias or classic bladder exstrophy, although rare mutations might be detectable in larger patient samples.

Möglichkeiten und Grenzen der transkraniellen Farbduplexsonographie bei der Darstellung intrakranieller arteriovenöser Malformationen

PURPOSE

Using transcranial color coded duplex sonography (TCCS) it is possible to visualize intracranial arteriovenous malformations (AVMs). The purpose of this study is to describe their typical ultrasonographic features and to define sensitivity for diagnosis with regard to the localization of an AVM.

MATERIALS AND METHODS

Over a period of six years we prospectively examined 54 intracranial AVMs confirmed by angiography. Using TCCS the vessels of the circle of Willis were identified by location, course and direction of flow on color flow images. The examination was performed during the first three years of the study using the Acuson 128 XP 10 system, equipped with a sector transducer with a 2.0/2.5 - MHz imaging frequency for the transcranial examination, and with a 7.0 MHz linear transducer fot the extracranial examination. During the second three years of the study, transcranial examination was performed with an Acuson Seqouia 512 ultrasound system equipped with a 2 - 4 MHz phased array transducer.

RESULTS

In accordance with digital subtraction angiography, the intracranial AVMs could be visualized in 42 cases (77.8 %). The major feeding vessels of the AVMs could be easily identified due to typical hemodynamic parameters showing increased systolic and diastolic flow velocities and decreased pulsatility index. We failed to visualize AVMs localized near the cortex, i. e. in the parietal, frontal, occipital and cerebellar regions of the brain. In contrast, 88.9 % of AVMs localized in the basal regions were very easy to image. Additionally, TCCS was useful for postoperative or postinterventional follow-up, although only a limited number of patients could be examined by TCCS in the post-treatment period.

CONCLUSION

TCCS is a noninvasive method for the diagnosis and possibly valuable in the long-term follow-up of intracranial AVMs. However, further research is needed to establish TCCS as an imaging modality in the follow-up after treatment of AVMs. The method can be regarded as a useful supplement to the palette of established, noninvasive diagnostic techniques such as MRI and MRA. However, since TCCS cannot rule out an AVM, angiography is still the method of choice for the definitive diagnosis.

Evaluation of cerebral perfusion deficit in stroke patients using new transcranial contrast imaging CPS technology--preliminary results

BACKGROUND AND PURPOSE

Contrast-enhanced transcranial duplex sonography can be used to examine cerebral perfusion. This technique, however, is still faced with methodological problems. The aim of the present study is to evaluate cerebral perfusion deficit after administration of the contrast agent SonoVue in acute stroke patients using new contrast imaging software.

METHODS

Ten subjects (6 male stroke patients and 4 healthy volunteers), were examined using transcranial duplex sonography (Acuson Sequoia 512 Ultrasound System) after a bolus injection of the contrast agent SonoVue. The transcranial examination was performed using transient response harmonic grey scale imaging with refill kinetics. The Sequoia ultrasonographic system was equipped with a new contrast harmonic imaging software "Cadence contrast pulse sequencing technology" (CPS). Triggered images with the mechanical index (MI) at 1.1 as well as continuous registration with MI at 0.28 were used for the evaluation of time intensity curves in several regions of interest. The sonographically imaged hypoperfused areas were compared with findings from MR imaging.

RESULTS

In all healthy volunteers, the contrast-enhanced signal could be recognized well in the ipsi- and also in the contralateral hemisphere up to the skull crown. In stroke patients, the perfusion deficit in the area of the MCA could be detected ipsilaterally in all subjects using triggered registration. Additionally, the area of MCA infarction could also be visualized in two patients using contralateral insonation. The low MI continuous imaging was successful in three patients. For all patients, the ischaemic region corresponded well in shape and size with the findings from MR imaging.

CONCLUSIONS

CPS enhances the possibility of perfusion-imaging in cerebral microcirculation and of perfusion-deficit-imaging in patients with cerebral ischaemia. Further studies with a larger number of patients should be carried out to improve this method.

Transcranial contrast imaging of cerebral perfusion in stroke patients following decompressive craniectomy

AIM

Contrast-enhanced transcranial triggered B-mode technology can be used to examine cerebral perfusion. However, this technique is still faced with methodological problems, especially the difficulty of overcoming the temporal bone window. The aim of the present study is to evaluate a deficit in cerebral perfusion after administration of the contrast agent SonoVue (TM) in acute stroke patients following decompressive craniectomy.

METHODS

Ten stroke patients (aged 39 to 59 years, mean age 57 years), in whom a decompressive craniectomy due to a malignant space-occupying infarction or intracerebral haemorrhage was performed, were examined with transcranial duplex sonography after application of the contrast agent SonoVue (TM). The transcranial examination was performed using transient response harmonic grey scale imaging with bolus kinetics based on a contrast harmonic imaging software with single-pulse transmission technology. The mechanical index was set at 1.0 to 1.1. Triggered images with pulsing intervals of 1000 ms were used for the evaluation of time intensity curves in several regions of interest. The sonographically imaged areas of hypoperfusion were compared with CT or MRI findings.

RESULTS

After injection of the contrast agent, the perfusion deficit could be detected ipsilaterally according to the affected vascular territory in the area of the MCA in 5 patients, in the area of ACA and MCA in 2 patients, in the area of the MCA, ACA and PCA in one patient and in the area of intracranial haemorrhage in 2 patients. The calculated average peak images corresponded precisely with the superimposed CT or MRI images in shape and size in all patients. Additionally, it was possible to observe several interesting contrast-induced phenomena in the cerebral parenchyma, as well as specific transit-time curve characteristics in the perfusion deficit area.

CONCLUSIONS

Using contrast-enhanced transcranial duplex sonography with transient response harmonic imaging, it is possible to depict the perfusion deficit in cerebral microcirculation in patients following decompressive craniectomy and to obtain new insights into the pathophysiology of the hypoperfusion areas. Further studies should be done in stroke patients through the intact skull to standardise this method for early diagnosis of acute deficit in cerebral perfusion.

[Dissection of the extracranial vertebral artery. Color duplex ultrasound findings and follow-up of 20 patients]

AIM

To assess the diagnostic potential of duplex color-flow imaging in the evaluation of extracranial vertebral artery dissection. In 15 of 20 patients (75%), the dissection was related to trauma.

METHOD

Over the last six years, we evaluated 20 consecutive patients aged 18 to 59 years with 24 extracranial vertebral artery dissections (four occurring bilaterally). The examinations were performed with a color Doppler imaging system using a 7 MHz transducer. Angiography was done in 18 patients, confirming the diagnosis.

RESULTS

In 15 patients, the diagnosis was primarily established with ultrasonography. Six vertebral arteries were dissected at the origin or in the proximal V1 segment, one in the distal V2 segment and one at the atlas loop. Most dissections occurred in the region between the V1 and V2 segments (n = 16), most often at the entrance of the artery into the transverse foramen of the C6 vertebra (n = 11). Typical ultrasonographic findings were irregular stenosis, dissecting membrane with true and false lumen, localized increase in diameter of the artery, pseudoaneurysm, intramural hematoma and tapering stenosis with distal occlusion. The diagnosis of dissection in the V3 segment was based on indirect signs such as high resistance flow pattern and decreased diastolic flow velocity. In follow-up examinations, marked resolution of pathological findings were found in 17 cases (70.8%). Two occlusions were completely recanalized.

CONCLUSION

Duplex color-flow imaging is a valuable noninvasive method for early diagnosis of extracranial vertebral artery dissection and for follow-up examinations.

Evaluation of extracranial vertebral artery dissection with duplex color-flow imaging

BACKGROUND AND PURPOSE

We describe the diagnostic potential of duplex color-flow imaging in the evaluation of extracranial vertebral artery dissection.

METHODS

Twenty patients with 24 extracranial vertebral artery dissections (four bilateral) were examined with duplex ultrasonography over a period of 6 years. Color-flow imaging was carried out in 16 of these patients. In 15 patients (75%), the dissection was temporally related to trauma. Angiography was available in 18 patients, confirming the diagnosis.

RESULTS

In 15 patients, the diagnosis was primarily established with ultrasonography. Five patients with a dissection were referred for follow-up color-flow examinations. Six vertebral arteries were dissected at the origin or in the proximal V1 segment, one in the distal V2 segment, and one at the atlas loop. In contrast to other studies, the most frequent localization of the dissection in our patients was the region between the V1 and V2 segments (n = 16), where the most typical dissection site was the entrance of the artery into the transverse foramen of the C6 vertebra (n = 11). Typical ultrasonographic findings were irregular stenosis, dissecting membrane with true and false lumen, localized increase in diameter of the artery, pseudoaneurysm, intramural hematoma, and tapering stenosis with distal occlusion. In follow-up examination, a good regression of pathological findings was found in 17 dissections (70.8%). Two occlusions were completely recanalized.

CONCLUSIONS

Extracranial vertebral artery dissections can be diagnosed noninvasively with duplex color-flow imaging. It is therefore a useful method for early diagnosis and follow-up examination.

Color Doppler imaging of basal cerebral arteries: normal reference values and clinical applications

Transcranial color-coded duplex ultrasonography is a new diagnostic procedure allowing the visualization of major intracranial vessels. The purpose of this report is to describe this method and to evaluate its practical potential in the routine examination of basal cerebral arteries. The results from the examination of 96 patients are presented. By means of color coding of Doppler frequencies, the major intracranial vessels were identified by nature of their anatomic location with respect to the echogenic brainstem structures in all subjects. The average maximal systolic velocity was, in the middle cerebral artery, 108 +/- 15 cm/s; in the anterior cerebral artery, 96 +/- 15; in the posterior cerebral artery, 76 +/- 16; and in the basilar artery, 59 +/- 17 cm/s. The determination of the angle between the ultrasonic beam and the examined vessel improved the accuracy of flow velocity measurements in comparison with conventional transcranial Doppler ultrasonography. The exact measurement of blood flow velocity in several segments of the visualized vessel proved helpful in the assessment of pathologic findings, especially in differentiation between a stenosis of the intracranial vessel and a vasospasm.

Quantitative measurements of blood flow velocity in basal cerebral arteries with transcranial duplex color-flow imaging. A comparative study with conventional transcranial Doppler sonography

Transcranial duplex color-flow imaging is a new diagnostic method that allows visual display of blood flow in the basal cerebral arteries. This method allows determination of and correction for the Doppler angle of insonation. Conventional transcranial Doppler sonography has no imaging component and assumes a 0-degree Doppler angle for the calculation of flow velocities. The magnitude of the angle of insonation and the effect on flow velocity estimates have not been clearly defined. In order to evaluate the angle of insonation and the effect of angle correction on velocity readings, 50 patients referred for evaluation of cerebrovascular disease were studied. The mean age was 45 years (range, 24-62 yr). All were examined with conventional transcranial Doppler and transcranial duplex color-flow imaging. Specific vessels of the circle of Willis were identified by location, course, and direction of flow on color-flow images and by depth, direction of flow, and transducer orientation with conventional Doppler sonography. Visually controlled measurements of the Doppler angle of insonation were made by color-flow imaging. The data show that the mean angle of insonation was 33 degrees (+/- 15) in the middle cerebral artery, 35 degrees (+/- 17) in the anterior cerebral artery, 45 degrees (+/- 18) in the posterior cerebral artery, and 15 degrees (+/- 14) in the basilar artery. Angle-corrected peak systolic flow velocities were higher in all vessel segments (middle cerebral = 15%, anterior cerebral = 18%, posterior cerebral = 30%, and basilar = 3%), compared to uncorrected velocity readings by conventional Doppler sonography.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transcranial color-coded duplex ultrasound--possibilities and limits of this method in comparison with conventional transcranial Doppler ultrasound]

The purpose of this report is to describe, based on the experience with 50 patients, transcranial colour-coded duplex ultrasonography and to evaluate its practical potential in the routine examination in comparison with conventional transcranial Doppler ultrasonography. Under visual control, the Doppler angle between the ultrasonic beam and the flow direction can be adjusted. The mean angle of incidence in the middle cerebral artery was 33 degrees +/- 15 degrees, in the anterior cerebral artery 35 degrees +/- 17 degrees, in the posterior cerebral artery 45 degrees +/- 18 degrees and in the basilar artery 15 degrees +/- 14 degrees. The measurements of blood flow velocity under consideration of the angle of incidence resulted in 15%, 18%, 30% and 3% respectively higher velocity values. Examples of pathologic findings demonstrate the practical potential of this noninvasive method.

Advantages of color Doppler imaging for the evaluation of vertebral arteries

Assessment of the vertebral arteries is often difficult with conventional duplex ultrasonography. This study of 60 patients aimed to determine the potential advantages of color Doppler imaging over conventional duplex ultrasonography in the evaluation of vertebral arteries, specifically three extracranial segments of these vessels. Both methods allowed visualization of the vertebral artery in the midcervical course (V2 and distal V1 segments) in all subjects. Color Doppler imaging appeared more effective for visualization of the V0 and the proximal V1 segments (on the right side in 88% of patients and on the left side in 73%). Conventional duplex ultrasonography imaged the ostium on the right side in 80% of patients and on the left side in 65%, but was difficult and time-consuming. Visualization at the atlas loop (V3 segment) was rarely successful with duplex sonography, whereas color Doppler imaging visualized the vertebral artery on the right side in 87% of patients and on the left side in 85%. Color Doppler imaging allows better visualization of the proximal and distal segments of the vertebral arteries, compared to conventional duplex ultrasonography.

Additive insulinotropic effects of exogenous synthetic human gastric inhibitory polypeptide and glucagon-like peptide-1-(7-36) amide infused at near-physiological insulinotropic hormone and glucose concentrations

Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1-(7-36) amide (GLP-1) are glucose-dependent insulinotropic gut hormones that may explain the greater insulin secretory response with oral compared to i.v. glucose (incretin effect). To study their individual and combined contributions, in eight healthy volunteers, on separate occasions, synthetic human GIP (1 pmol/kg.min) and/or GLP-1 (0.3 pmol/kg.min) or placebo were infused i.v. (-30 to 120 min), while at 0 min, a glucose infusion "isoglycemic" to the profile after an oral glucose load of 50 g/400 mL was started. After the administration of 50 g oral glucose, immunoreactive GIP rose several-fold to 337 +/- 43 pmol/L, while there was only a transient (10-30 min) and moderate increment in immunoreactive GLP-1 (from basal, 25-30, to 41 +/- 4 pmol/L). Isoglycemic i.v. glucose infusions led to smaller B-cell responses (estimated incretin effect, 41 +/- 5%). With single infusions of GIP or GLP-1 (circulating concentrations, 464 +/- 73 and 54 +/- 3 pmol/L, respectively), B-cell responses were significantly augmented compared to i.v. glucose alone and were no longer significantly different from those after oral glucose. The combination of GIP and GLP-1 led to B-cell responses that were significantly higher than those with either hormone alone (additive mode of cooperation). Plasma GIP concentrations were similar after endogenous secretion (oral glucose) and i.v. infusion, while exogenously administered GLP-1 led to plasma levels that were maintained at an elevated level for a longer period during exogenous infusion than after stimulation by oral glucose. When, in seven volunteers, a lower dose (0.15 pmol/kg.min) of GLP-1 was infused during isoglycemic glucose infusion experiments only for the duration of elevated plasma levels in the oral glucose challenges (0-30 min), a significant, but transient, increment in insulin and C-peptide concentrations was observed, which was equivalent to 26 +/- 10% of the estimated incretin effect. Therefore, in conclusion, circulating GIP seems to make a major contribution to the incretin effect after oral glucose, and GLP-1 appears to mediate a smaller proportion. GIP and GLP-1 can interact in an additive manner in normal man.

Duplex ultrasonography of vertebral arteries: examination, technique, normal values, and clinical applications

A technique for the imaging of vertebral arteries at their origins and along the longitudinal extracranial course is described. The results of the examination of 108 normal vertebral arteries are shown. The vertebral artery could be distinguished in the pretransverse and intertransverse segment C5-C6 in 100%. The average diameter of the vessel was 3.81 +/- 0.46 mm on the right and 3.88 +/- 0.47 on the left side. The average maximal systolic velocity was 43.0 +/- 8.9 cm/s on the right and 43.3 +/- 9.6 on the left side. In 81% of the cases the vertebral origin could be located on the right and in 65% of the cases on the left side. The technical quality of visualization, especially of the vertebral origin, was greatly influenced by the depth of the examined structure. Examples of pathologic findings, such as hypoplasia, stenosis, and occlusion, demonstrate the practical possibilities of this noninvasive method.

Lack of effect of synthetic human gastric inhibitory polypeptide and glucagon-like peptide 1 [7-36 amide] infused at near-physiological concentrations on pentagastrin-stimulated gastric acid secretion in normal human subjects

Gastric inhibitory polypeptide (GIP) and glucagon-like peptide 1 [7-36 amide] (GLP-1) are glucose-dependent insulinotropic gut hormones. Under experimental conditions, both have been shown to reduce stimulated gastric acid secretion. To study their individual and combined effects on pentagastrin-stimulated (0.1 micrograms/kg/h from -90 to 120 min) gastric volume, acid and chloride output, on separate occasions, synthetic human GIP (1 pmol/kg/min) and/or GLP-1 [7-36 amide] (0.3 pmol/kg/min) or placebo (0.9% NaCl with 1% albumin) were infused intravenously (from -30 to 120 min) in 9 healthy volunteers. At 0 min, a glucose infusion was started that mimicked the glycemic profile after an oral glucose load of 50 g/400 ml and allowed for the glucose-dependent insulinotropic action of GIP and GLP-1 [7-36 amide]. Pentagastrin stimulated acid output significantly, but neither GIP nor GLP-1 [7-36 amide] either alone or in combination, reduced pentagastrin-stimulated gastric acid secretion. The circulating concentrations of GIP and GLP-1 [7-36 amide] obtained at steady state during exogenous administration of synthetic peptides were similar to or higher than those reached after oral glucose (endogenous secretion). In conclusion, (penta)gastrin-stimulated gastric acid secretion is not inhibited by physiological circulating concentrations of GIP or GLP-1 [7-36 amide]. Therefore, the insulinotropic action of these intestinal hormones is physiologically more important than their possible role as enterogastrone.

[Intraductal chemotherapy of bile duct cancer with 5-fluorouracil]

The prognosis of bile duct cancer is still poor. Curative surgical therapy is possible in only 10%-20% of cases. Palliative effects of chemotherapy and radiation are small. Newer palliative techniques like iridium 192 wire radiation or hepatic artery infusion of chemotherapeutic agents seem to be more effective. Another new form of palliative local chemotherapy, intrabiliary application of 5-fluorouracil, is described. A 67-year-old woman with an adenocarcinoma of the left and common hepatic ducts received symptomatic therapy by an external biliary drainage for 20 months. In the following 3 weeks the amount of drained bile diminished and finally stopped, while icterus occurred. Catheter cholangiography showed a right catheter position, the known obstruction of the common hepatic duct and the left bile duct, and a diffuse right-sided peripheral bile duct occlusion, regarded as multifocal tumor spreading. Intraductal application of 5-fluorouracil via the PTCD tube, 125-375 mg twice a week, effected a rising bile secretion after a few days, to a final volume of 1,000 ml/day. An X-ray control 34 days after start of the therapy showed a nearly complete reopening of the formerly occluded peripheral bile duct system and a filiform reopening of the common hepatic duct with sufficient flowing off into the common bile duct and the duodenum. Certain side effects of this therapy were not noticed. After successful reopening of malignant bile tract occlusion, other palliative therapeutic techniques like internal bile drainage or iridium 192 wire radiation can be applied.