The neuropsychiatric phenotype in CACNA1A mutations: a retrospective single center study and review of the literature

BACKGROUND AND PURPOSE

CACNA1A encodes the α1 subunit of the neuronal calcium channel P/Q. CACNA1A mutations underlie three allelic disorders: familial hemiplegic migraine type 1 (FHM1), episodic ataxia type 2 (EA2) and spinocerebellar ataxia type 6 (SCA6). A clear-cut genotype-phenotype correlation is often lacking since clinical manifestations may overlap. Several case reports have described cognitive and behavioral features in CACNA1A disorders, but studies in larger case series are lacking.

METHODS

Genetically confirmed CACNA1A cases were retrieved from the database of the ataxia outpatient clinic of the Department of Neurology at Innsbruck Medical University. Clinical charts and neuropsychological test results were retrospectively analyzed. In addition, a review of the literature including only genetically confirmed cases was performed.

RESULTS

Forty-four CACNA1A cases were identified in our database. Delayed psychomotor milestones and poor school performance were described in seven (four FHM1, three EA2) and eight (three FHM1, five EA2) patients, respectively. Psychiatric comorbidities were diagnosed in eight patients (two FHM1, six EA2). Neuropsychological testing was available for 23 patients (11 FHM1, 10 EA2, two SCA6). Various cognitive deficits were documented in 21 cases (all patients except one SCA6). Impairments were predominantly seen in figural memory, visuoconstructive abilities and verbal fluency. In the literature, an early psychomotor delay is described in several children with EA2 and FHM1, whilst reports of cognitive and psychiatric findings from adult cases are scarce.

CONCLUSIONS

Neuropsychiatric manifestations are common in episodic CACNA1A disorders. In the case of otherwise unexplained developmental delay and a positive family history, CACNA1A mutations should be considered in the differential diagnosis.

PIAS1 is a determinant of poor survival and acts as a positive feedback regulator of AR signaling through enhanced AR stabilization in prostate cancer

Novel drugs like Abiraterone or Enzalutamide, which target androgen receptor (AR) signaling to improve androgen deprivation therapy (ADT), have been developed during the past years. However, the application of these drugs is limited because of occurrence of inherent or acquired therapy resistances during the treatment. Thus, identification of new molecular targets is urgently required to improve current therapeutic prostate cancer (PCa) treatment strategies. PIAS1 (protein inhibitor of activated STAT1 (signal transducer and activator of transcription-1)) is known to be an important cell cycle regulator and PIAS1-mediated SUMOylation is essential for DNA repair. In this context, elevated PIAS1 expression has already been associated with cancer initiation. Thus, in the present study, we addressed the question of whether PIAS1 targeting can be used as a basis for an improved PCa therapy in combination with anti-androgens. We show that PIAS1 significantly correlates with AR expression in PCa tissue and in cell lines and demonstrate that high PIAS1 levels predict shorter relapse-free survival. Our patient data are complemented by mechanistic and functional in vitro experiments that identify PIAS1 as an androgen-responsive gene and a crucial factor for AR signaling via prevention of AR degradation. Furthermore, PIAS1 knockdown is sufficient to decrease cell proliferation as well as cell viability. Strikingly, Abiraterone or Enzalutamide treatment in combination with PIAS1 depletion is even more effective than single-drug treatment in multiple PCa cell models, rendering PIAS1 as a promising target protein for a combined treatment approach to improve future PCa therapies.

Spectrum of enteropathogens detected by the FilmArray GI Panel in a multicentre study of community-acquired gastroenteritis

The European, multicentre, quarterly point-prevalence study of community-acquired diarrhoea (EUCODI) analysed stool samples received at ten participating clinical microbiology laboratories (Austria, Finland, France, Germany, Greece, Ireland, Italy, Portugal, Romania, and the UK) in 2014. On four specified days, each local laboratory submitted samples from ≤20 consecutive patients to the Austrian Study Centre for further testing with the FilmArray GI Panel (BioFire Diagnostics, Salt Lake City, UT, USA). Of the 709 samples from as many patients received, 325 (45.8%) tested negative, 268 (37.8%) yielded only one organism, and 116 (16.4%) yielded multiple organisms. Positivity rates ranged from 41% (30 of 73 samples) in France to 74% (59 of 80 samples) in Romania. With the exception of Entamoeba histolytica and Vibrio cholerae, all of the 22 targeted pathogens were detected at least once. Enteropathogenic Escherichia coli, Campylobacter species, toxigenic Clostridium difficile, enteroaggregative E. coli, norovirus and enterotoxigenic E. coli were the six most commonly detected pathogens. When tested according to local protocols, seven of 128 positive samples (5.5%) yielded multiple organisms. Overall, the FilmArray GI Panel detected at least one organism in 54.2% (384/709) of the samples, as compared with 18.1% (128/709) when testing was performed with conventional techniques locally. This underlines the considerable potential of multiplex PCR to improve routine stool diagnostics in community-acquired diarrhoea. Classic culture methods directed at the isolation of specific pathogens are increasingly becoming second-line tools, being deployed when rapid molecular tests give positive results. This optimizes the yield from stool examinations and dramatically improves the timeliness of diagnosis.

First Neisseria gonorrhoeae strain with resistance to cefixime causing gonorrhoea treatment failure in Austria, 2011

We describe the first cefixime-resistant Neisseria gonorrhoeae strain in Austria that caused treatment failure.It follows the first five cases in Europe of cefixime treatment failure, reported in Norway in 2010 and the United Kingdom in 2011. Effective treatment of gonorrhoea is crucial for public health control and, at present, requires substantially enhanced awareness, more frequent test-of-cure, interaction with experts after therapeutic failure, tracing and therapy of contacts, and surveillance of gonococcal antimicrobial resistance and treatment failures worldwide.

First Neisseria gonorrhoeae strain with resistance to cefixime causing gonorrhoea treatment failure in Austria, 2011

We describe the first cefixime-resistant Neisseria gonorrhoeae strain in Austria that caused treatment failure. It follows the first five cases in Europe of cefixime treatment failure, reported in Norway in 2010 and the United Kingdom in 2011. Effective treatment of gonorrhoea is crucial for public health control and, at present, requires substantially enhanced awareness, more frequent test-of-cure, interaction with experts after therapeutic failure, tracing and therapy of contacts, and surveillance of gonococcal antimicrobial resistance and treatment failures worldwide.

A new biliodigestive anastomosis technique to prevent reflux and stasis

BACKGROUND

The Roux-en-Y procedure for biliodigestive drainage is most widely accepted, but 10% to 15% of patients postoperatively suffer from a blind-loop syndrome or cholangitis due to motility disorders. A new biliodigestive technique is evaluated in a rat model to prevent these complications.

METHODS

This experimental study in Wistar rats compares the Roux-en-Y technique with a new biliodigestive anastomosis creating a jejunal loop with luminal occlusion. Clinical parameters, small bowel motility, bacteriologic growth, and liver histopathology were evaluated in native and postoperative animals within a study period of 180 days.

RESULTS

Both operative procedures were well tolerated. After 6 months intense fibrosis of the liver and high-grade purulent cholangitis were observed in animals in the Roux-en-Y group. In these animals enterobacter and enterococci overgrowth was found. Myoelectric small bowel recordings revealed significant impairment of slow-wave frequency, aboral velocity, and action potentials (percentage of phase III) in Roux-en-Y animals.

CONCLUSIONS

Motility disorders after conventional Roux-en-Y biliodigestive anastomosis are pivotal for histomorphological damage and infectious findings and can be prevented by using the new technique to create a jejunal loop with luminal occlusion.

The impact of jejunal transplant peristalsis on enteric flora

The importance of phase III of the migrating myoelectric complex (MMC) for homeostasis of enteric flora is well documented. The goal of this study was to evaluate in an isogeneic rat model the effect of MMC changes on the self-purging capacity of the jejunal graft. The proximal 25% of the entire jejunoileum of Lewis rats was transplanted orthotopically. Electrodes were then fixed to the graft. Native bowel of five rats and five rats with analogue jejunal segmentation served as controls. Myoelectric recordings were carried out until day 21, when animals were killed for bacteriologic analysis of the segments analyzed myoelectrically and the of neighboring gut. MMCs were observed in all animals during all recordings. Phase III was irregular in transplants because of long-lasting periods of phase III absence alternating with phase III occurring more frequently. The variation coefficient of phase III periodicity calculated for grafts was 48.74, for native bowel 14.79, and for segmented jejunum 22.9. Enteric flora found in all specimens consisted of colonic-like microorganisms. Titers of microorganisms in grafts did not differ from control segments. These findings show that phase III periodicity is severely altered in jejunal grafts. Homeostasis of enteric flora, however, is not influenced by the transplant procedure.

Vero cytotoxin-producing Escherichia coli O157 infections in Austria

To determine the prevalence of Vero cytotoxin-producing Escherichia coli (VTEC) serotype O157 associated diarrhea in the Austrian patient population, we surveyed all stool specimens of liquid consistency submitted to the Federal Public Health Laboratory (FPHL) in Innsbruck for 2 years for this organism. This laboratory serves a population of approximately 1 Million people. Of 5,265 stool specimens, 7 yielded O157 VTEC. Five isolates of E. coli O157 phage type 32, VT2 were cultured from specimens received during a three day period from residents in the county of Schwaz. During the investigation of this "outbreak" E. coli O157 strains were also isolated from two household contacts. Only 1 out of 8 persons with E. coli O157 diarrhea had bloody stools, although 5 of 7 tested specimens (= 71%) also yielded Campylobacter jejuni. None of our patients received antimicrobial therapy directed against E. coli O157 (one child had josamycin). There were no fatalities and no cases of hemolytic uremic syndrome (follow up period: 6 months). Consumption of hamburger, roast beef, and unpasteurized milk was not confirmed in this study. In Austria, no O157 VTEC strain was isolated till June 1992, although at the FPHL in Innsbruck stool specimens of liquid consistency were cultured for this organism since January 1991.

[Therapy-refractory fulminant meningococcal sepsis]

Two cases of the severe form of meningococcal infection are described. A 17-year-old girl and a (unrelated) 2-year-old boy suddenly developed fever and rigor. Several hours later petechiae of the skin were noted: they rapidly spread. On admission the girl was found to have a severe consumptive coagulopathy (prothrombin 24%, partial thromboplastin time 104 sec, fibrinogen 73 mg/dl, platelets 35,000/microliters). She died two-and-a-half hours after admission of treatment-resistant shock. The boy had at first only a low prothrombin value (39%), but later the other coagulation values also became abnormal. He died 16 hours after admission from the consumptive coagulopathy and profound anaemia (haemoglobin 7.4 g/dl, haematocrit 0.23). Neither patient had any clinical signs of meningitis. Isolation of Neisseria meningitidis from blood cultures confirmed the diagnosis.

Interaction between C3 and IL-2; inhibition of C3b binding to CR1 by IL-2

We previously reported that C3 has a role in the enhancement of the IL-2 dependent proliferation of helper T cells. Because the IL-2R has a structural homology with the complement proteins, such as CR1 and CR2, we studied the possible ligand crossreactions on CR1 and IL-2-receptor, and the direct interaction between C3 and IL-2. While C3 has an enhancing effect on the IL-2 dependent proliferation of HT-2, a CR1-positive mouse T-cell line, the growth of the CTLL-16 line (CR1-negative) is not affected by C3. It has been proven that neither the insolubilized C3 nor the soluble C3b-like C3 react with the IL-2 binding epitope of the IL-2 receptor. However, using human RBC we have demonstrated that the binding of aggregated C3 to CR1 is inhibited by rIL-2, in a dose-dependent manner. When RBC were incubated with rIL-2 and FITC-labelled Fab-anti-CR1 simultaneously, there was no inhibition in the fluorescence intensity. As detected by ELISA, rIL-2 was bound to the same extent by insolubilized C3, C3b, and C3c, while C3d coat had lower binding capacity. The receptor-binding epitope of IL-2 is intact in the complex of complement proteins and rIL-2, as demonstrated by the binding of DMS1, a monoclonal antibody reacting with the receptor site of IL-2. It is strongly suggested that C3b may play a role in the growth of CR1 positive T cells.

C3bi-binding protein on Candida albicans: temperature-dependent expression and relationship to human complement receptor type 3

We investigated in detail the previously described capacity of pseudohyphae of Candida albicans to bind C3-coated particles. We show that the expression of the C3bi receptor of C. albicans was dependent upon the growth temperature of the fungi. C. albicans grown at 30 degrees C bound strongly to EAC1423bi, whereas those cells grown at 38.5 degrees C were completely devoid of this capacity. The molecule responsible for the attachment of EAC1423bi was heat labile and trypsin sensitive. Several, but not all, monoclonal antibodies to the alpha-chain of human complement receptor type 3 (CR3) stained C. albicans, and this reactivity was expressed in parallel with the capacity of C. albicans to bind EAC1423bi, i.e., both were dependent on the growth temperature of the fungi and were trypsin sensitive. In contrast to CR3, the binding of EAC1423bi to C. albicans did not require the presence of divalent cations. Rabbit immunoglobulin G antibodies directed against C. albicans inhibited the binding of EAC1423bi to C. albicans but not to human CR3. These inhibiting IgG antibodies recognized antigens expressed on the surface of pseudohyphae but not those of yeast cells. OKM-1, a monoclonal antibody to human CR3 inhibited the attachment of EAC1423bi to CR3 and also to C. albicans. OKM-1 precipitated a 130-kilodalton band from solubilized 125I-labeled C. albicans. We conclude that the complement receptors on C. albicans and human CR3 were antigenically related but not identical and that they differed in their functional characteristics.

Structural and functional relationships among receptors and regulators of the complement system

The classical and alternative pathway of complement activation are regulated by a series of fluid phase and cell-bound factors, some of which at the same time serve as receptors for fragments of C3 and C4. These molecules are factor H, CR1 (C3b/C4b receptor), CR2 (C3d/EBV receptor), C4BP (C4b binding protein), DAF (decay accelerating factor), MCP (membrane cofactor protein; earlier designated p45/70), CR3 (iC3b receptor or Mac-1) and CR4 (protein 150/95). Due to structural, genetic and functional features these factors are members of one or several newly recognized large families of proteins: (1) molecules with 60 amino acids long repeats (H, CR1, CR2, C4BP, DAF); (2) proteins with 1,2-diacylglycerol membrane anchoring (DAF); (3) proteins with a heterodimer structure and preference for ligands containing the tripeptide arginine-glycine-asparagine (CR3, CR4). Recognizing the above mentioned regulators and receptors of the complement system as belonging to these protein families opens new perspectives for further genetic and functional research of mutual interest to complement and noncomplement scientists.

Cell cycle control of a Burkitt lymphoma cell line: responsiveness to growth signals engaging the C3D/EBV receptor

CR2, the receptor for the C3d fragment of the third complement component and for Epstein-Barr virus (EBV) has been shown, on mouse B cells, to be involved in the control of B-cell proliferation by acting as a receptor for macrophage-derived growth factors. We examined whether the growth of a Burkitt lymphoma cell line, RAJI, could be influenced by ligands of human CR2. In serum-free culture, purified human C3d, as well as three monoclonal antibodies to distinct epitopes on human CR2, were capable of enhancing the growth rate of RAJI cells two to five-fold. This effect could not be observed if even trace amounts of serum were present in the culture medium. Simultaneous addition of pairs of antibodies did not enhance the growth rate, suggesting that a particular engagement of CR2 may be critical in order to induce a stimulatory effect. These results indicate that in a homologous serum-free human B-cell system human C3d as well as monoclonal antibodies to human CR2 can induce B-cell proliferation and that CR2-mediated triggering of B cells can be induced via epitopes other than the C3d-binding site. In addition we conclude that--unlike normal human B cells--at least some human B-lymphoma cells respond to CR2-mediated stimuli in the absence of any T-cell derived factors. Therefore the control mechanisms exerted through CR2 must still be intact on these autonomously growing cells.

Structural and functional analysis of CR2/EBV receptor by means of monoclonal antibodies and limited tryptic digestion

The receptor for the C3d fragment of the third component of complement, CR2, has recently been shown also to act as the receptor for the Epstein-Barr virus (EBV) and to be involved in the control of B-cell proliferation. In order to define functionally important domains on this molecule, we produced monoclonal antibodies to several distinct epitopes. CR2 was purified from a NP-40 lysate of human tonsils by a new method involving sequential chromatography on lentil lectin Sepharose 4B and DEAE-Sephadex and used to immunize mice. After fusion we obtained four stable hybridoma lines producing antibody to CR2. Specificity of these antibodies for CR2 was ascertained by immunofluorescence analysis on a panel of various cells known to possess CR2, by their reactivity in a recently described ELISA for C3 receptors, by Western blotting with purified CR2 and immunoprecipitation from 125I-labelled Raji cells. These four antibodies were found to recognize three distinct epitopes localized on the same fragments of 95,000, 72,000, 50,000, 32,000 and 28,000 MW obtained after mild tryptic digestion of CR2. The 72,000 MW fragment contains the binding site for C3d. Two monoclonal antibodies recognizing the same epitope did not inhibit the binding of C3d-coated sheep erythrocytes to Raji cells, whereas the other two antibodies against distinct epitopes did inhibit in the presence of a second antibody. All four monoclonal antibodies stimulated the proliferation of human peripheral blood B cells.