Angiotensin-converting enzyme 2, the complement system, the kallikrein-kinin system, type-2 diabetes, interleukin-6, and their interactions regarding the complex COVID-19 pathophysiological crossroads

Because of the current COVID-19-pandemic, the world is currently being held hostage in various lockdowns. ACE2 facilitates SARS-CoV-2 cell-entry, and is at the very center of several pathophysiological pathways regarding the RAAS, CS, KKS, T2DM, and IL-6. Their interactions with severe COVID-19 complications (e.g. ARDS and thrombosis), and potential therapeutic targets for pharmacological intervention, will be reviewed.

Left-handedness in cardiac surgery: who's right?

There is a paucity of literature describing potential issues related to lateral hand dominance in general and cardiac surgery. Nonetheless, during surgical training left-handedness can produce difficulties in the operating room that are not always understood or accepted by supervising right-handed surgeons. These problems can be easily overcome by practice and anticipation. This report aims to address laterality related issues in cardiac surgery and provide insight into techniques that may aid the left handed surgeon in a right handed dominated surgical environment. An ergonomically different approach, more convenient for the left-handed trainee, may facilitate learning, enhance confidence and increase surgeon satisfaction both for the trainer and trainee.

Comparison of two minimally invasive enilconazole perendoscopic infusion protocols for the treatment of canine sinonasal aspergillosis

OBJECTIVES

To compare two minimally invasive enilconazole infusion protocols for the treatment of canine sinonasal aspergillosis and evaluate the importance of complete endoscopic debridement in determining first treatment success rate.

MATERIALS AND METHODS

Data for 48 dogs with confirmed sinonasal aspergillosis treated with endoscopic debridement followed by per-endoscopic enilconazole infusion were collected. Twenty-four dogs were treated according to the previously published 1-hour infusion protocol and 24 dogs underwent a simplified 15-minute infusion protocol. Completeness of debridement, evaluated as partial or complete at the end of the procedure and outcome after one or several treatments were assessed in all dogs. Multi-variable analysis was performed to derive odds ratios and 95% confidence intervals.

RESULTS

The median duration of the simplified protocol - 92∙3 minutes (range 40 to 140) - was substantially shorter than the duration of the previous protocol - 201∙3 minutes (range 120 to 265). First treatment success rates were 58 and 62∙5% for the previous and simplified protocol, respectively. Overall treatment success rate was similar in both groups (96%). Complete debridement was associated with an improved first treatment success rate compared to partial debridement.

CLINICAL SIGNIFICANCE

The simplified protocol is a valid alternative approach to the treatment of sinonasal aspergillosis. Completeness of endoscopic debridement before infusion is an important step for the success of treatment in canine sinonasal aspergillosis.

Oxidative stress and lung pathology following geogenic dust exposure

This study was designed to evaluate markers of systemic oxidative stress and lung histopathology following subacute exposure to geogenic dust with varying heavy metal content collected from a natural setting prone to wind erosion and used heavily for off-road vehicle recreation. Adult female B6C3F1 mice were exposed to several concentrations of dust collected from seven different types of surfaces at the Nellis Dunes Recreation Area in Clark County, Nevada, designated here as CBN 1-7. Dust representing each of the seven surface types, with an average median diameter of 4.2 μm, was selected and administered via oropharyngeal aspiration to mice at concentrations from 0.01 to 100 mg of dust kg(-1) of body weight. Exposures were given four times spaced a week apart over a 28 day period to mimic a month of weekend exposures. Lung pathology was evaluated while plasma markers of oxidative stress included levels of reactive oxygen and nitrogen species, superoxide dismutase, total antioxidant capacity and total glutathione. Overall, results of these assays to evaluate markers of oxidative stress indicate that no single CBN surface type was able to consistently induce markers of systemic oxidative stress at a particular dose or in a dose-response manner. All surface types were able to induce some level of lung inflammation, typically at the highest exposure levels. These data suggest that dust from the Nellis Dunes Recreation Area may present a potential health risk, but additional studies are necessary to characterize the full extent of health risks to humans. Copyright © 2016 John Wiley & Sons, Ltd.

Conservative Treatment of Left Ventricular Free Wall Rupture

We present a case of post-infarction Left Ventricular Free Wall Rupture (LVFWR), in which conservative treatment was successfully applied. A 48-year old male patient presented at our emergency department with abdominal pain and a clinical presentation of shock. There had been an episode of chest pain three days before admission. Electrocardiogram was suggestive for old myocardial infarction. Coronarography revealed an occlusion of a diagonal branch. Computed Tomography scan was performed to exclude a rupturing aortic aneurysm, but a large pericardial effusion was seen. Echocardiography confirmed the diagnosis of cardiac tamponade and pericardiocentesis was performed. Conservative treatment consisting of bed rest, blood pressure control and beta-blocker therapy was applied, allowing the patient to be discharged after 10 days. The diagnosis of LVFWR was confirmed by cardiac magnetic resonance imaging.Surgery is considered as the golden standard in treatment of LVFWR. This case illustrates that in selected patients conservative treatment is possible.

Evolution of the management of acquired neurogenic bladder in children using intradetrusor botulinum toxin type A injections: 5-year experience and perspectives

OBJECTIVE

To report the clinical and urodynamic results of repeated intradetrusor botulinum toxin type A injections in children with an acquired neurogenic bladder.

PATIENTS AND METHOD

We reviewed the data of 8 patients presenting an acquired neurogenic bladder treated between 2005 and 2010. Their mean age was 12.4 years old (range: 5-18). They were all on clean intermittent catheterization. All patients presented detrusor overactivity resistant to oral anticholinergic treatment. They received between 2 and 6 injections at a dose of 12 botulinum toxin units (BU)/kg (maximum 300 BU). Cystometry was performed 4-8 weeks after treatment.

RESULTS

Five patients became completely dry, 2 were only rarely wet, and data are lacking for 1 patient. Febrile urinary tract infections ceased after 1 or 2 injections. The mean maximal detrusor pressure decreased below 40 cmH(2)O after 1, 2 and 3 injections. The normalized safe capacity rose significantly after 1, 2 and 3 injections. The normalized maximal bladder capacity rose similarly after 1, 2 and 3 injections although not always significantly.

CONCLUSION

Intradetrusor botulinum toxin-A injections significantly reduce detrusor pressure and can be repeated with efficacy. They have their place in between anticholinergic treatment and surgery. The procedure could be simplified and the dosage reduced.

Optimal profit of the parasitation by Aphelinus mali in an IPM complementary strategy for the control of Eriosoma lanigerum

During summer the parasitoid Aphelinus mali may certainly reduce the infestation of woolly apple aphid (Eriosoma lanigerum), but studies on the single interaction rarely indicate sufficient biological control in the period May-June. In this period chemical control by spirotetramat or pirimicarb remains indispensable in order to anticipate on dense migration waves and subsequent colonization of extension shoots by E. lanigerum. The limited parasitation by A. mali around flowering is linked with a delayed emergence from diapause and with a slower reproduction rate than its host. In 2010 and 2011 the first adult flights monitored on yellow sticky traps corresponded perfectly with the currently used prediction models for A. mali. Further accurate monitoring all along the season enabled also to determine a well defined endo-parasitic phase of A. mali occurring after the small peak observed around flowering. During this endo-parasitic phase A. mali larvae reside inside their mummified host. Compounds with higher acute toxicity on A. mali adults, like chloronicotinyl insecticides (CNI's), are preferably positioned here. Selectivity in the time can then be claimed. Respecting this principle, the further parasitation potential of A. mali in summer is not hampered. Preservation of the first peak of flights of A. mali in the pre-flowering period is essential for an exponential flight increase. This is essential for the parasitation of E. lanigerum in summer, which constitutes a valuable complement in the integrated control strategy.

Mutation analysis of TMC1 identifies four new mutations and suggests an additional deafness gene at loci DFNA36 and DFNB7/11

Hearing loss is the most frequent sensorineural disorder affecting 1 in 1000 newborns. In more than half of these babies, the hearing loss is inherited. Hereditary hearing loss is a very heterogeneous trait with about 100 gene localizations and 44 gene identifications for non-syndromic hearing loss. Transmembrane channel-like gene 1 (TMC1) has been identified as the disease-causing gene for autosomal dominant and autosomal recessive non-syndromic hearing loss at the DFNA36 and DFNB7/11 loci, respectively. To date, 2 dominant and 18 recessive TMC1 mutations have been reported as the cause of hearing loss in 34 families. In this report, we describe linkage to DFNA36 and DFNB7/11 in 1 family with dominant and 10 families with recessive non-syndromic sensorineural hearing loss. In addition, mutation analysis of TMC1 was performed in 51 familial Turkish patients with autosomal recessive hearing loss. TMC1 mutations were identified in seven of the families segregating recessive hearing loss. The pathogenic variants we found included two known mutations, c.100C>T and c.1165C>T, and four new mutations, c.2350C>T, c.776+1G>A, c.767delT and c.1166G>A. The absence of TMC1 mutations in the remaining six linked families implies the presence of mutations outside the coding region of this gene or alternatively at least one additional deafness-causing gene in this region. The analysis of copy number variations in TMC1 as well as DNA sequencing of 15 additional candidate genes did not reveal any proven pathogenic changes, leaving both hypotheses open.

Chromosome 10q harbors a susceptibility locus for bipolar disorder in Ashkenazi Jewish families

We report the results of a 10 cM density genome-wide scan and further fine mapping of three chromosomal candidate regions in 10 Belgian multigenerational families with bipolar (BP) disorder. This two-stage approach revealed significant evidence for linkage on chromosome 10q21.3-10q22.3, showing a maximum multipoint parametric heterogeneity logarithm of odds (HLOD) score of 3.28 and a nonparametric linkage (NPL) score of 4.00. Most of the chromosome 10q evidence was derived from a single, large Ashkenazi Jewish pedigree. Haplotype analysis in this pedigree shows that the patients share a 14-marker haplotype, defining a chromosomal candidate region of 19.2 cM. This region was reported previously as a candidate region for BP disorder in several independent linkage analysis studies and in one large meta-analysis. It was also implicated in a linkage study on schizophrenia (SZ) in Ashkenazi Jewish families. Additionally, we found suggestive evidence for linkage on chromosome 19q13.2-13.4 (HLOD 2.01, NPL 1.09) and chromosome 7q21-q22 (HLOD 1.45, NPL 2.28). Together, these observations suggest that a gene located on chromosome 10q21.3-10q22.3 is underlying the susceptibility both for SZ and for BP disorder in at least the Ashkenazi Jewish population.

Progranulin locus deletion in frontotemporal dementia

Ubiquitin-positive, tau-negative, frontotemporal dementia (FTD) is caused by null mutations in progranulin (PGRN; HUGO gene symbol GRN), suggesting a haploinsufficiency mechanism. Since whole gene deletions also lead to the loss of a functional allele, we performed systematic quantitative analyses of PGRN in a series of 103 Belgian FTD patients. We identified in one patient (1%) a genomic deletion that was absent in 267 control individuals. The deleted segment was between 54 and 69 kb in length and comprised PGRN and two centromeric neighboring genes RPIP8 (HUGO gene symbol RUNDC3A) and SLC25A39. The patient presented clinically with typical FTD without additional symptoms, consistent with haploinsufficiency of PGRN being the only gene contributing to the disease phenotype. This study demonstrates that reduced PGRN in absence of mutant protein is sufficient to cause neurodegeneration and that previously reported PGRN mutation frequencies are underestimated.

Familial occipitotemporal lobe epilepsy and migraine with visual aura: Linkage to chromosome 9q

OBJECTIVE

To map the disease-causing locus in a large Belgian family with occipitotemporal lobe epilepsy associated with migraine with visual aura and to describe the clinical, electrophysiologic, and imaging characteristics.

METHODS

DNA samples from 21 family members were obtained and an 8 cM density genome-wide scan was performed. The authors interviewed 21 individuals and performed interictal EEG in 14 and brain MRI in 13 individuals.

RESULTS

Nine at risk family members and one deceased individual had epilepsy with occipital and temporal lobe symptomatology, variable age at onset, usually good prognosis, no epileptic EEG features, and normal brain MRI. Five of the 10 patients had a history of migraine with aura (p = 0.0026). Seizures and migraine attacks occurred as separate episodes in all but one patient. Three patients described light flashes both as epileptic and migraine aura. Epilepsy and migraine started at the same age in three patients and remitted simultaneously in two. The epileptic phenotype had a dominant mode of inheritance with a reduced penetrance of 75%. A conclusive two-point lod score of 3.3 was obtained for marker D9S257 at recombination fraction zero. Haplotype analysis defined a candidate region of 9.95 cM (5.96 Mb) between markers GATA152H04 and D9S253 located at chromosome 9q21-q22 based upon recombinations in affected individuals.

CONCLUSIONS

The clinical association in this family of occipitotemporal lobe epilepsy and migraine with visual aura and the conclusive linkage of the occipitotemporal lobe epilepsy/migraine with aura trait to a single locus suggests a common monogenic gene defect.

Familial occipitotemporal lobe epilepsy and migraine with visual aura: linkage to chromosome 9q

OBJECTIVE

To map the disease-causing locus in a large Belgian family with occipitotemporal lobe epilepsy associated with migraine with visual aura and to describe the clinical, electrophysiologic, and imaging characteristics.

METHODS

DNA samples from 21 family members were obtained and an 8 cM density genome-wide scan was performed. The authors interviewed 21 individuals and performed interictal EEG in 14 and brain MRI in 13 individuals.

RESULTS

Nine at risk family members and one deceased individual had epilepsy with occipital and temporal lobe symptomatology, variable age at onset, usually good prognosis, no epileptic EEG features, and normal brain MRI. Five of the 10 patients had a history of migraine with aura (p = 0.0026). Seizures and migraine attacks occurred as separate episodes in all but one patient. Three patients described light flashes both as epileptic and migraine aura. Epilepsy and migraine started at the same age in three patients and remitted simultaneously in two. The epileptic phenotype had a dominant mode of inheritance with a reduced penetrance of 75%. A conclusive two-point lod score of 3.3 was obtained for marker D9S257 at recombination fraction zero. Haplotype analysis defined a candidate region of 9.95 cM (5.96 Mb) between markers GATA152H04 and D9S253 located at chromosome 9q21-q22 based upon recombinations in affected individuals.

CONCLUSIONS

The clinical association in this family of occipitotemporal lobe epilepsy and migraine with visual aura and the conclusive linkage of the occipitotemporal lobe epilepsy/migraine with aura trait to a single locus suggests a common monogenic gene defect.

Rh glycoproteins in epithelial cells: lessons from rat and mice studies

Rhesus glycoproteins are a recently discovered family of ammonium transporters and a new branch of the Mep/AMT proteins superfamily that was identified more than 15 years ago in lower organisms and plants. Despite many ex vivo studies showing evidences that Rh glycoproteins can accelerate transmembrane NH3 or NH4+ transfer, their role in normal and disease physiology remains unknown. This review focuses on some of the different studies carried out in animal models to gain insight into Rh glycoprotein function. Immunolocalization studies have added new evidence that this protein family is related to ammonium transport or metabolism in epithelial cells. However, the absence of distal tubular acidosis or hyperammonemia in Rhbg KO mice have raised new questions about the physiological significance of these proteins.

Generation of mice with inactivated Rh or Rhag genes

Mice carrying inactivated Rh and Rhag genes were generated by insertional targeting. KO animals exhibited normal growth, development and fertility and both types were indistinguishable at a gross phenotypic level from their wild type littermates. Preliminary analysis revealed that red cells from Rh-/- mice lack Rh protein and have a moderate decrease of Rhag protein, whereas those from Rhag-/- mice have a total absence of Rhag and Rh proteins. Studies are in progress to delineate the antigenic, biochemical and functional abnormalities of red cells from these animals as well as the impact on hematological parameters and erythropoiesis.

Role of RhAG and AQP1 in NH3 and CO2 gas transport in red cell ghosts: a stopped-flow analysis

To clarify the potential role Rh/RhAG and AQP1 proteins in erythrocyte gas transport, NH3 and CO2 transport was measured in erythrocyte ghost membrane vesicles from rare human variants (Rh(null), CO(null),) and knockout mice (homozygous AQP1-/-, Rh-/- and Rhag-/-) exhibiting well-characterized protein defects. Transport was measured from intracellular pH (pHi) changes in a stopped-flow fluorimeter. NH3 transport was measured in chloride-free conditions with ghosts exposed to 20 mM inwardly directed gradients of gluconate salts of ammonium, hydrazine and methylammonium at 15 degrees C. Alkalinization rates of control samples were 6.5+/-0.3, 4.03+/-0.17, 0.95+/-0.08 s(-1) for each solute, respectively, but were significantly reduced for Rh(null) and CO(null) samples that are deficient in RhAG and AQP1 proteins, respectively. Alkalinization rates of Rh(null) ghosts were about 60%, 83% and 94% lower than that in control ghosts, respectively, for each solute. In CO(null) ghosts, the lack of AQP1 resulted in about 30% reduction of the alkalinization rates as compared to controls, but the transport selectivity of RhAG for the three solutes was preserved. Similar observations were made with ghosts from KO mice Rhag-/- and AQP1-/-. These results confirm the major contribution of RhAG/Rhag in the NH3 conductance of erythrocytes and suggest that the reduction of transport rates in the absence of AQP1 would be better explained by a direct or indirect effect on RhAG/Rhag-mediated transport. When ghosts were preloaded with carbonic anhydrase and exposed to a 25 mM CO2/HCO3- gradient at 6 degrees C, an extremely rapid kinetics of acidification corresponding to CO2 influx was observed. The rate constants were not significantly different between controls and human variants (125+/-6 s(-1)), or between wild-type and KO mice, suggesting no major role of RhAG or AQP1 in CO2 transport, at least in our experimental conditions.

A novel susceptibility locus at 2p24 for generalised epilepsy with febrile seizures plus

Generalised epilepsy with febrile seizures plus (GEFS+) is a clinically and genetically heterogeneous epilepsy syndrome. Using positional cloning strategies, mutations in SCN1B, SCN1A, and GABRG2 have been identified as genetic causes of GEFS+. In the present study, we describe a large four generation family with GEFS+ in which we performed a 10 cM density genome-wide scan. We obtained conclusive evidence for a novel GEFS+ locus on chromosome 2p24 with a maximum two point logarithm of the odds (LOD) score of 4.22 for marker D2S305 at zero recombination. Fine mapping and haplotype segregation analysis in this family delineated a candidate region of 3.24 cM, corresponding to a physical distance of 4.2 Mb. Linkage to 2p24 was confirmed (p = 0.007) in a collection of 50 nuclear and multiplex families with febrile seizures and epilepsy. Transmission disequilibrium testing and association studies provided further evidence (p < 0.05) that 2p24 is a susceptibility locus for febrile seizures and epilepsy. Furthermore, we could reduce the candidate region to a 2.14 cM interval, localised between D2S1360 and D2S2342, based upon an ancestral haplotype. Identification of the disease gene at this locus will contribute to a better understanding of the complex genetic aetiology of febrile seizures and epilepsy.

Survival of the probiotic, L. plantarum 299v and its effects on the faecal bacterial flora, with and without gastric acid inhibition

INTRODUCTION

Probiotic bacteria have to survive passage through the gastrointestinal tract. In this placebo-controlled double-blind study, the effect of Lactobacillus plantarum 299v on the faecal flora was studied with and without gastric acid inhibition.

METHODS

Thirty-two healthy volunteers were given pantoprazole (40 mg/day) or placebo for 3 weeks from week 2 until week 4. In addition, from week 3 until week 4, L. plantarum 299v in an oatmeal-fermented drink (10(9) CFU/ml) was given twice daily to both groups. From each healthy volunteer, faecal samples were collected at the end of week 1, 2, 4 and 8 (4 weeks after cessation of L. plantarum 299v and pantoprazole/placebo). Several aerobically and anaerobically growing bacteria were counted and short chain fatty acid concentrations were determined.

RESULTS

In both the pantoprazole and the placebo group, median lactobacilli counts increased significantly in week 4 compared to week 1 (from log 4.5 to 8.0 CFU/g faeces in pantoprazole and from log 4.2 to 7.7 CFU/g faeces in placebo group) and decreased significantly in week 8 (to log 4.5 CFU/g faeces in pantoprazole and log 4.3 CFU/g faeces in placebo group). These lactobacilli were identified as L. plantarum 299v. No significant differences were observed in all other bacterial counts and short chain fatty acid concentrations.

CONCLUSIONS

The comparable increase of faecal lactobacilli counts in both the pantoprazole and the placebo-treated group demonstrates that L. plantarum 299v survives passage through the gastrointestinal tract irrespective of gastric acidity. The increment of the intra-gastric pH in combination with L. plantarum 299v did not modulate bacterial composition and/or the production of short chain fatty acids.

[Palatal myoclonus and dysphagia]

INTRODUCTION

Post brainstem lesion dysphagia is frequently associated with palatal myoclonus (PM) but the correlation between these two symptoms is still unclear.

OBJECTIVE

The aim of this study was to verify the relationship between PM and dysphagia, and if PM could itself induce dysphagia.

PATIENTS AND METHODS

Twelve patients suffering from post brainstem lesion PM and dysphagia; 10 male and two female, mean aged of 50.5 years, were assessed using clinical examination, radiological and endoscopic examination of deglutition.

RESULTS

In three cases, PM were associated with pharyngeal area decreasing, laryngeal aspiration, and dysphagia.

DISCUSSION

This study confirms the hypothesis of close relationship between PM and dysphagia. In these cases, specific dysphagia therapy should be recommended.

CONCLUSION

Post brainstem lesion dysphagia is sometimes associated with PM and in some cases, there is probably a relationship between PM and swallowing disorders of these patients.

Probiotics in gastroenterology: indications and future perspectives

Nowadays. there is a growing interest in probiotics as a safe way of changing the intestinal bacterial flora. Probiotics may have potential in several gastroenterological conditions, especially when the intestinal flora has been disturbed. Most scientific evidence is available for diarrhoea patients treated with Lactobacillus GG, Lactobacillus reuteri or Saccharomyces boulardii. Meta-analyses have shown an overall reduction in the risk of antibiotic-associated diarrhoea during treatment with probiotics, and benefits have also been demonstrated for patients with rota-virus-associated diarrhoea. Patients with inflammatory bowel disease, an inflammatory disorder characterized by a change in the intestinal flora, are another important target group for which probiotics may be beneficial. It has been claimed that in ulcerative colitis and Crohn disease patients, lactobacilli, S. boulardii and Escherichia coli reduce relapses. but most studies were not placebo-controlled. A reduction in relapses has also been demonstrated in pouchitis patients treated with a multispecies probiotic. Irritable bowel syndrome might be another clinical indication for probiotic therapy, but results of clinical trials performed in these patients are inconsistent. Additionally, probiotics may improve lactose absorption. Helicobacter pylori eradication and constipation. Finally, in animal models of colorectal cancer, treatment with probiotics reduces the prevalence of this disease, and in humans the amount of genotoxic substances in faeces has been reduced. In conclusion, the results of studies on the effects of probiotics in gastrointestinal conditions are encouraging. but well-designed placebo-controlled studies are warranted before recommendations for therapeutic or preventive use can be given. Many issues still have to be resolved, including optimal dose and duration of treatment, selection of and differences between the several available probiotic strains, and, importantly, their mechanisms of actions have to be elucidated.

The effect of Lactobacillus plantarum 299v on the bacterial composition and metabolic activity in faeces of healthy volunteers: a placebo-controlled study on the onset and duration of effects

AIM

To study the onset and duration of a possible effect of a fermented oatmeal drink containing Lactobacillus plantarum 299v on the composition of the faecal flora of healthy volunteers in a placebo-controlled, double-blind study.

METHODS

Twenty-two participants consumed a fermented oatmeal drink with or without L. plantarum 299v for 4 weeks. Faecal samples were collected weekly: two samples before, four during and four after the consumption of the drink. Several bacterial species were counted and enzyme activities, short-chain fatty acid concentrations, endotoxin concentration and pH were determined. L. plantarum 299v was identified using randomly amplified polymorphic DNA.

RESULTS

In contrast with the placebo group, median lactobacilli counts increased significantly from 4.2 (3.4-6.3) to 8.2 (7.3-8.5) log colony-forming units/gram faeces (P = 0.005) after 1 week of consumption of L. plantarum 299v, thereafter remaining stable during the treatment period. One week after cessation, a significant decrease in lactobacilli [to 4.4 (2.2-6.5) log colony-forming units/gram faeces] was observed (P = 0.003). These lactobacilli were identified as L. plantarum 299v. All other bacterial counts, enzyme activities, short-chain fatty acid concentrations, endotoxin concentration and pH remained unchanged.

CONCLUSIONS

L. plantarum 299v significantly increased the number of lactobacilli in the faecal flora within 1 week, and this effect disappeared within 1 week after cessation of intake. No other changes in bacterial counts and metabolic products were observed.

A novel CpG-associated brain-expressed candidate gene for chromosome 18q-linked bipolar disorder

We previously identified 18q21-q22 as a candidate region for bipolar (BP) disorder and constructed a yeast artificial chromosome (YAC) contig map. Here we identified three potential CpG islands using CCG/CGG YAC fragmentation. Analysis of available genomic sequences using bioinformatic tools identified an exon of 3639 bp downstream of a CpG island of 1.2 kb containing a putative transcription initiation site. The exon contained an open reading frame coding for 1212 amino acids with significant homology to the SART-2 protein; weaker homology was found with a series of sulphotransferases. Alignment of cDNA sequences of corresponding ESTs and RT-PCR sequencing predicted a transcript of 9.5 kb which was confirmed by Northern blot analysis. The transcript was expressed in different brain areas as well as in multiple other peripheral tissues. We performed an extensive mutation analysis in 113 BP patients. A total of nine single nucleotide polymorphisms (SNPs) were identified. Five SNPs predicted an amino acid change, of which two were present in BP patients but not in 163 control individuals.

Trinucleotide repeat expansions: do they contribute to bipolar disorder?

It has long been known that bipolar disorder has a true but complex genetic background. Reports on genetic anticipation in bipolar disorder opened the way to a new approach for genetic studies. Indeed, anticipation, a decreasing age at onset, and/or increasing disease severity in successive generations, were recently explained by an expansion of trinucleotide repeats in monogenic diseases like Huntington's disease and Fragile X syndrome. The involvement of trinucleotide repeat expansions in bipolar disorder received even more support when studies reported association of large CAG/CTG repeats with bipolar disorder. Even though a large number of studies have been conducted, this association is still unexplained. Here, we review the studies investigating the trinucleotide repeat expansion hypothesis in bipolar disorder. Studies on anticipation, on association of anonymous large CAG/CTG repeats and on specific trinucleotide repeats are critically analysed and discussed, showing a field with precipitate conclusions or inconclusive results. The analysis suggests that there are indications, though disputable, supporting the trinucleotide repeat expansion hypothesis in bipolar disorder, but no conclusive evidence has been hitherto provided.

No evidence for the involvement of CAG/CTG repeats from within 18q21.33-q23 in bipolar disorder

We previously identified 18q21.33-q23 as a candidate region in one BP family and constructed a yeast artificial chromosome (YAC) contig map. Here, we mapped eight known CAG/CTG repeats relative to 18q21.33-q23. We also isolated four CAG/CTG repeats from within the region using CAG/CTG YAC fragmentation, one of which is located in the 5' untranslated region of the CAP2 gene coding for a brain-expressed serine proteinase inhibitor. The triplet repeats located in the 18q21.33-q23 BP candidate region showed no expanded alleles in the linked BP family nor in a BP case-control sample. Moreover, only the CAP2 triplet repeat was polymorphic but no genetic association with BP disorder was observed.

A soluble recombinant multimeric anti-Rh(D) single-chain Fv/CR1 molecule restores the immune complex binding ability of CR1-deficient erythrocytes

CR1 (CD35, the C3b/C4b receptor) is a widely distributed membrane glycoprotein with a unique cluster conformation on the surface of erythrocytes (E). CR1 on E is responsible for the transport of immune complexes (IC) to liver and spleen. As a cofactor of the C3b cleavage by factor I, CR1 is also a potent inhibitor of C activation and inflammation. In some diseases (systemic lupus erythematosus, hemolytic anemia, AIDS, etc.) an acquired low level of CR1 on E has been observed, leading to an impaired clearance of IC. The aim of this study was to design a heterofunctional molecule that will bind to E and restore a normal or a supranormal CR1 density on E that could mimic the unique distribution pattern of CR1 on normal E. For that purpose a new multimerizing system based on the properties of the C-terminal part of the alpha-chain of the C4 binding protein (C4bp) was used. We first produced a multimeric soluble CR1 that proved to be a better inhibitor of in vitro C activation than the monomeric form of CR1, then a heteromultimeric molecule made of CR1 and single-chain Fv anti-Rh(D) valences able to attach E and providing E with as much as a 10-fold increase in CR1 density with the same CR1 distribution pattern as native E. CR1/single-chain Fv anti-Rh(D)-treated E were able in vitro to attach as many opsonized IC as native E. These data open the way for future use of multimeric and heteromultimeric forms of soluble recombinant CR1 as therapy of IC diseases.

Characterization of a mouse liminin receptor gene homologous to the human blood group Lutheran gene

The human Lutheran (Lu) blood group antigens are carried by two glycoproteins (gps) that belong to the immunoglobulin (Ig) superfamily. These gps represent adhesion molecules that function as the unique erythroid receptors for laminin. We report here the cloning and functional expression of the orthologous mouse Lu mRNA as well as the genomic organization of the mouse Lu gene. The deduced human and mouse Lu gps share 72.5% identity and similar organization of the Ig-like domains. As in the human, the mouse Lu gene is organized in 15 exons. The proximal promoter showed consensus CACC-binding sites whereas the distal promoter exhibits a GATA-1-binding site and multiple E boxes. Like the human gene, the mouse Lu gene is also widely expressed among tissues but is transcribed as a unique 2.4-kb mRNA species. Expression of the mouse Lu mRNA is upregulated upon dimethyl sulfoxide-induced erythroid differentiation of murine erythroleukemia cells (MEL). During mouse embryonic development, the Lu transcript is detected as early as day 7 of gestation. Analysis of transfected human erythroleukemia K562 cells indicated that the adhesive properties of the Lu gps to laminin are conserved between human and mouse.

Isolation of CAG/CTG repeats from within the chromosome 2p21-p24 locus for autosomal dominant spastic paraplegia (SPG4) by YAC fragmentation

Pure autosomal dominant spastic paraplegia (SPG) is a genetically heterogeneous neurodegenerative disorder of the central nervous system clinically characterized by progressive spasticity mainly affecting the lower limbs. Three distinct loci have been mapped to chromosomes 14q (SPG3), 2p (SPG4) and 15q (SPG6). In particular, SPG4 families show striking intrafamilial variability suggestive of anticipation and evidence has been provided that CAG/CTG repeat expansions may be involved. To isolate CAG/CTG repeat containing sequences from within the SPG4 candidate region, a novel approach was developed. Fragmentation vectors were assembled allowing direct fragmentation of yeast artificial chromosomes (YACs) with a short (> or = 21 bp) CAG/CTG sequence as the target site for homologous recombination. We used the CAG/CTG YAC fragmentation vectors to isolate CAG/CTG containing sequences from four YACs spanning the SPG4 candidate region between D2S400 and D2S367. A total of four CAG/CTG containing sequences were isolated of which three were novel. However, none of the four CAG/CTG repeats showed expanded alleles in two Belgian SPG4 families. In addition, we showed that the CAG/CTG alleles detected by the repeat expansion detection (RED) method could be fully explained by two polymorphic nonpathogenic CAG/CTG repeats on chromosomes 17 and 18, respectively. Also, the RED expansions in six SPG families could not be explained by amplification of the CAG/CTG repeats at the SPG4 locus. Together, our data do not support the hypothesis of a CAG/CTG repeat expansion as the molecular mechanism underlying SPG4 pathology.

YAC fragmentation with repetitive and single-copy sequences: detailed physical mapping of the presenilin 1 gene on chromosome 14

We constructed new LYS2 fragmentation vectors that allow direct acentric and centric fragmentation of yeast artificial chromosomes (YACs) and selection of fragmented YACs in yeast strain AB1380. The fragmentation vectors were used efficiently with repetitive (e.g., Alu), low-copy (e.g., CA-repeats) and single-copy (e.g., exons) sequences. High recombination efficiencies were obtained in fragmenting two different CEPH YACs with the Alu consensus sequence as target sequences for homologous recombination. Analysis of the acentric Alu fragmentation panel of 788H12, containing the presenilin 1 (PSEN1) gene for familial Alzheimer's disease (AD), indicated that high-resolution YAC fragmentation panels covering the entire parent YAC are obtained. Also, marker content analysis of the fragmentation panel indicated that fragmented YACs were propagated stably without rearrangements. The same fragmentation vectors were used efficiently for fragmentation of 788H12 with unique sequences, i.e., exons 3 and 12 of PSEN1 and D14S77, a polymorphic CA repeat, as target sequences. Together, our YAC fragmentation data of 788H12 provided a size estimate for the coding region of PSEN1 of 60kb and a more precise localization of D14S77 at 25kb upstream of PSEN1.

Molecular genetic analysis of autosomal dominant cerebellar ataxia with retinal degeneration (ADCA type II) caused by CAG triplet repeat expansion

Autosomal dominant cerebellar ataxia with retinal degeneration (ADCAII) was previously mapped by linkage analysis studies to chromosome 3p12-p21.1 (SCA7). Positional cloning efforts have recently identified a novel gene, SCA7 , containing a translated CAG repeat, expanded in SCA7 patients. We cloned the SCA7 gene from a yeast artificial chromosome (YAC) clone contig spanning the SCA7 candidate region. Using a combination of genomic sequencing and cosmid-based exon trapping, two expressed sequence tags were identified. Sequencing of the corresponding cDNA clones and RT-PCR analysis identified the full-length SCA7 cDNA. Together, our sequence data defined the intron/exon boundaries of the first two coding exons of the SCA7 gene, with the first exon containing the expanded CAG repeat. Further, sequence comparison with the published SCA7 cDNA identified one additional putative exon in the 5'-UTR region of the SCA7 gene. The SCA7 gene was mapped on the YAC contig in the 2.5 cM interval between D3S1600 and D3S1287. In one extended Belgian SCA7 pedigree the expanded alleles ranged from 38 to at least 55 repeats with allele lengths being inversely correlated with onset age of ADCAII symptoms. The SCA7 repeats increased in length in successive generations. Normal alleles had from four to 18 repeats, with 10 repeats being the most common allele.

Predictors of hospital mortality in type A aortic dissections: a retrospective analysis of 148 consecutive surgical patients

Reports in the literature frequently concern miscellaneous types of dissections. This makes correct interpretation of data difficult. In order to assess the determinants of hospital mortality, the results of 148 consecutive patients over a 23-year period, all operated on for a type A dissection, were reviewed. Mean(s.d.) age was 56(13.1) years, 64% were male. An acute dissection (surgery within 14 days after onset of symptoms) was performed in 139 patients. Stigmata of the Marfan syndrome were present in 6.1% (n = 9). Peripheral vascular ischaemic complications were observed in 27.7%. Nowadays, diagnosis is primarily confirmed using transoesophageal echocardiography (75 correct diagnoses among 76 performed). Operation consisted of repair or replacement of the ascending aorta. Resuspension of the aortic valve was performed in 74 patients, and arch replacement in 25. In 74 patients, distal repair was done under deep hypothermic circulatory arrest. Hospital mortality rate was 23.6% (35 patients), though mortality rate calculated over the period 1990-1993 was 17.4% (P = n.s.). Univariate analysis revealed the following variables to be statistically significant predictors of hospital mortality (P < 0.05): preoperative ischaemic complications, preoperative resuscitation, haemopericardium, postoperative neurological complications, rethoracotomy, renal insufficiency and intestinal ischaemia. Multivariate stepwise logistic regression indicated preoperative resuscitation, postoperative haemodialysis and postoperative neurological complications as the only independent predictors of hospital death. Dissections arising from a primary intimal tear in the descending aorta had a more favourable outcome (P = 0.06, odds ratio 0.1). Although hospital mortality has declined over the past few years, no decline was seen in operative mortality since gelatine-resourcine-formol (GRF) glue is used as a routine. Transoesophageal echocardiography is the first choice in confirming diagnosis. Early operation is advocated, with careful haemostasis, before the development of cardiac tamponade or end-organ ischaemia, as the cornerstone of a successful treatment of a type A dissection. Reduction of neurological complications will further improve the results.

A recombinant human scFv anti-Rh(D) antibody with multiple valences using a C-terminal fragment of C4-binding protein

Monomeric recombinant molecules prove generally unsatisfactory for in vivo use. Most biological systems are indeed multivalent either structurally, associating different chains, or functionally, when cross-linked by their ligands. Mimicking natural molecules for immune intervention implies the need for multimerizing systems to create multivalent molecules capable of interfering with physiological processing. A multivalent anti-Rh(D) recombinant protein has been designed by reconstructing the antibody binding site of a human monoclonal anti-Rh(D) antibody as a single chain Fv mini antibody, then multimerizing it by inserting at its C-terminal end the C-terminal part of the C4 binding protein (C4bp) alpha chain, which is responsible for the octamer multimerization of that molecule. This soluble multivalent recombinant molecule was functional, bound red blood cells (RBCs), agglutinated them, and did not activate complement. This demonstration model opens the way for future in vivo use of multivalent molecules associating antibody valences and other functional molecules for cell targeting, imaging, or removal of cells such as Rh(D)-positive RBCs for preventing Rh alloimmunization.

Reoperative aortic root surgery late after use of histo-acryl

Cardiovascular reoperations after the use of histo-acryl are extremely rare. A patient is described, who underwent an aortic root replacement according to Bentall's technique, for a postdissectional aneurysm. At that time, to achieve hemostasis, histo-acryl adhesive was applied and a Cabrol's fistula was created. Fourteen years later, a recurrent 'false', aneurysm had developed and the fistula had a hemodynamically significant left-right shunt. At reoperation, the composite graft was replaced by a cryopreserved aortic root allograft with long coronary arteries. To our knowledge, this is the first report of a cardiovascular reoperation after previous use of histo-acryl. This patient also merits attention as to the fact that it illustrates a failure of a modified Cabrol's procedure.

'In vivo' size of knitted Dacron prostheses (Gelseal) used in the thoracic aorta: a computed tomography study

When replacing the thoracic aorta, gelatin-sealed triaxial knitted Dacron prostheses are used as they have zero porosity and are easy to handle. It is known that knitted prostheses (not triaxially constructed), when implanted in the abdominal aorta or in the peripheral vessels, show a dilatation of 10-20%. The initial in vivo expansion of this prosthesis in the thoracic aorta was assessed using computed tomography scanning in 18 patients. The graft sizes used were 18mm (n = 4). 20mm (n = 5). 22mm (n = 4), 26mm (n = 1), 28mm (n = 2) and 30mm (n = 2). All patients were kept normotensive postoperatively. Computed tomography scan measurement was performed within 4 weeks of operation. using standard computed tomography equipment and no contrast. Two radiologists checked and agreed upon the slice levels and measurements compared with the manufacturer's stated size referring to internal diameter of the crimped prosthesis. The mean(s.d.) 'in vivo' size was 16.2(6)% larger. This 'true size' should be taken as the reference measurement when considering further dilatation over the period of follow-up.