Inactivation of PNKP by mutant ATXN3 triggers apoptosis by activating the DNA damage-response pathway in SCA3.

Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD), is an untreatable autosomal dominant neurodegenerative disease, and the most common such inherited ataxia worldwide. The mutation in SCA3 is the expansion of a polymorphic CAG tri-nucleotide repeat sequence in the C-terminal coding region of the ATXN3 gene at chromosomal locus 14q32.1. The mutant ATXN3 protein encoding expanded glutamine (polyQ) sequences interacts with multiple proteins in vivo, and is deposited as aggregates in the SCA3 brain. A large body of literature suggests that the loss of function of the native ATNX3-interacting proteins that are deposited in the polyQ aggregates contributes to cellular toxicity, systemic neurodegeneration and the pathogenic mechanism in SCA3. Nonetheless, a significant understanding of the disease etiology of SCA3, the molecular mechanism by which the polyQ expansions in the mutant ATXN3 induce neurodegeneration in SCA3 has remained elusive. In the present study, we show that the essential DNA strand break repair enzyme PNKP (polynucleotide kinase 3'-phosphatase) interacts with, and is inactivated by, the mutant ATXN3, resulting in inefficient DNA repair, persistent accumulation of DNA damage/strand breaks, and subsequent chronic activation of the DNA damage-response ataxia telangiectasia-mutated (ATM) signaling pathway in SCA3. We report that persistent accumulation of DNA damage/strand breaks and chronic activation of the serine/threonine kinase ATM and the downstream p53 and protein kinase C-d pro-apoptotic pathways trigger neuronal dysfunction and eventually neuronal death in SCA3. Either PNKP overexpression or pharmacological inhibition of ATM dramatically blocked mutant ATXN3-mediated cell death. Discovery of the mechanism by which mutant ATXN3 induces DNA damage and amplifies the pro-death signaling pathways provides a molecular basis for neurodegeneration due to PNKP inactivation in SCA3, and for the first time offers a possible approach to treatment.

Cardiac involvement in total generalized lipodystrophy (Berardinelli- Seip syndrome)

Total generalized lipodystrophy (Berardinelli--Seip Syndrome) is a rare hereditary disease characterized by insulin-resistant diabetes mellitus and a small quantity of adipose tissue and is of unknown origin. Common cardiovascular alterations related to this syndrome are cardiac hypertrophy and arterial hypertension. This article reports a case of Berardinelli--Seip syndrome and reviews the literature with special emphasis on the cardiovascular manifestations of this syndrome.

Cardiac tamponade in systemic lupus erythematosus. Report of four cases

OBJECTIVE: To report and assess the incidence of cardiac tamponade in systemic lupus erythematosus as a cardiac manifestation of the disease. METHODS: We reviewed the medical records of 325 patients diagnosed with systemic lupus erythematosus according to the American Rheumatism Association and their complementary laboratory tests compatible with cardiac tamponade. RESULTS: In the 325 medical recors reviewed, we found 108 patients with pericardial effusions corresponding to 33.2% of the total and 54% of the patients studied in the active phase of the disease. Clinical assessment and transthoracic echocardiogram allowed the clinical diagnosis of cardiac tamponade in only 4 (1.23%) patients, 3 of whom were females, white, with ages ranging from 25 to 44 years. The pericardial fluid was hemorrhagic or serosanguineous with high levels of FAN and positivity for LE cells. In the treatment, we successfully used pericardicentesis associated with high doses of corticosteroids. In clinical and laboratory follow-up performed for a period of 3 years, neither recrudescence of the pericardial effusion nor evolution to constriction occurred. CONCLUSION: Even though rare (1.23%), cardiac tamponade in patients with systemic lupus erythematosus has a benign evolution when properly treated, according to our experience.

Fibrinolytic therapy for thrombosis in cardiac valvular prosthesis short and long term results

OBJECTIVE: To assess the short- and long-term results of the use of streptokinase (SK) for the treatment of thromboses in cardiac valvular prostheses. METHODS: Seventeen patients with cardiac prosthetic thrombosis diagnosed by clinical, echocardiographic, and radioscopic findings underwent fibrinolytic treatment with a streptokinase bolus of 250,000 U followed by 100.000 U/hour. Short- and long-term results were assessed by radioscopy and echocardiography. RESULTS: Of the 17 patients, 12 had mechanical double-disk prostheses (4 aortic, 6 mitral, 2 tricuspid), 4 had single-disk prostheses (2 aortic, 1 mitral, and 1 tricuspid), and 1 had a tricuspid bioprosthesis. The success rate was 64.8%, the partial success rate was 17.6%, and the nonsuccess rate was 17.6%. All patients with a double-disk prosthesis responded, completely or partially, to the treatment. None of the patients with a single-disk prosthesis had complete resolution of the thrombosis. The time of streptokinase infusion ranged from 6 to 80 hours (mean of 56 h). The mortality rate due to the use of streptokinase was 5.8% and was secondary to cerebral bleeding. During streptokinase infusion, 3 (17.6%) embolic episodes occurred as follows: 1 cerebral, 1 peripheral, and 1 coronary. The rethrombosis index was 33% in a mean follow-up of 42 months. CONCLUSION: The use of fibrinolytic agents was effective and relatively safe in patients with primary thrombosis of a double-disk prosthesis. A fatal hemorrhagic complication occurred in 1 (5.8%) patient, and embolic complications occurred in 3 (17.6%) patients. In a mean 42-month follow-up, 67% of the patients were free from rethrombosis.

Analysis of haemochromatosis mutations in the North West population

Background: Hereditary haemochromatosis is a heritable disorder caused by an inborn error in the metabolism of iron. It results in over absorption of iron by the body, which can manifest clinically as fatigue, arthritis, diabetes and cardiovascular problems. The highest prevalence for the genetic mutations that cause hereditary haemochromatosis can be found in the Irish population. Individuals with diabetes may also have haemochromatosis (and vice versa), due to the bi-directional relationship between iron metabolism and glucose metabolism. Objectives: To determine the incidence of the three haemochromatosis mutations C282Y, H63D & S65C, in a population from the North West of Ireland and to investigate whether there is an increased frequency of these three mutations in a diabetic population from the same region. Method: DNA was extracted from 500 whole blood samples (250 diabetic samples and 250 ‘control’ samples) using a Wizard™ kit. PCR was conducted utilising specific primers for each mutation and in accordance with a set protocol. Following amplification, PCR product was subjected to restriction endonuclease digestion, where different restriction enzymes (Rsa I, Nde II & Hinf I) were employed to determine the HFE genotype status of samples. Results: The incidence of C282Y homozygosity (1/83) and C282Y heterozygosity (1/6) in the ‘control’ group was similar to those reported for the general Irish population (1/83 and 1/5, respectively). Incidences of H63D homozygotes and H63D heterozygotes or ‘carriers’ in the diabetic population were greater than that of the ‘control’ population. A significant finding of this study was that of an incidence of 1/32 S65C carriers in the control population. This is, to our knowledge, the highest incidence of the genotype reported to date in the general Irish population. Statistical analysis showed that there was no significant differences between the HFE genotype frequencies in the Diabetic and Control Populations. Conclusion: Results of the study concord with published literature in terms of C282Y homozygosity and C282Y heterozygosity in the general Irish population. An increased frequency of the H63D mutation in diabetic individuals was also found but was not statistically significant. The biochemical effect of the H63D mutation is still unknown. The significance of such a high incidence of S65C carriers in the ‘control’ population warrants further investigation.

Femoral versus Radial Access in Primary Angioplasty. Analysis of the ACCEPT Registry

Background:The radial access provides a lower risk of bleeding and vascular complications related to the puncture site in comparison to the femoral access. Recent studies have suggested a reduction in mortality associated with the radial access in patients with acute myocardial infarction undergoing percutaneous coronary intervention.Objective:To compare the occurrence of adverse cardiovascular ischemic and hemorrhagic events in patients undergoing primary angioplasty according to the type of arterial access route.Methods:From August 2010 to December 2011, 588 patients undergoing primary percutaneous coronary intervention during acute ST-segment elevation myocardial infarction were assessed; they were recruited from 47 centers participating in the ACCEPT registry. Patients were grouped and compared according to the arterial access used for the procedure.Results:The mean age was 61.8 years; 75% were males and 24% had diabetes mellitus. There was no difference between groups as regards the procedure success rate, as well as regards the occurrence of death, reinfarction, or stroke at six months of follow-up. Severe bleeding was reported in 1.1% of the sample analyzed, with no statistical difference related to the access used.Conclusions:The femoral and radial accesses are equally safe and effective for the performance of primary percutaneous coronary intervention. The low rate of cardiovascular events and of hemorrhagic complications reflects the quality of the participating centers and the operators expertise with the use of both techniques.

Atrial Fibrillation and Non-cardiovascular Diseases: A Systematic Review

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an unfavorable prognosis, increasing the risk of stroke and death. Although traditionally associated with cardiovascular diseases, there is increasing evidence of high incidence of AF in patients with highly prevalent noncardiovascular diseases, such as cancer, sepsis, chronic obstructive pulmonary disease, obstructive sleep apnea and chronic kidney disease. Therefore, considerable number of patients has been affected by these comorbidities, leading to an increased risk of adverse outcomes.The authors performed a systematic review of the literature aiming to better elucidate the interaction between these conditions.Several mechanisms seem to contribute to the concomitant presence of AF and noncardiovascular diseases. Comorbidities, advanced age, autonomic dysfunction, electrolyte disturbance and inflammation are common to these conditions and may predispose to AF.The treatment of AF in these patients represents a clinical challenge, especially in terms of antithrombotic therapy, since the scores for stratification of thromboembolic risk, such as the CHADS2 and CHA2DS2VASc scores, and the scores for hemorrhagic risk, like the HAS-BLED score have limitations when applied in these conditions.The evidence in this area is still scarce and further investigations to elucidate aspects like epidemiology, pathogenesis, prevention and treatment of AF in noncardiovascular diseases are still needed.

Hereditariedade da homeose

A preliminary account on the normal development of the imaginai discs in holometabolic Insects is made to serve as an introduction to the study of the hereditary homoeosis. Several facts and experimental data furnished specially by the students of Drosophila are brought here in searching for a more adequate explanation of this highly interesting phenomenon. The results obtained from the investigations of different homoeotic mutants are analysed in order to test Goldschmidt's theory of homoeosis. Critical examination of the basis on which this theory was elaborated are equally made. As a result from an extensive theoretical consideration of the matter and a long discussion of the most recent papers on this subject the present writer concludes that the Goldschmidt explanation of the homoeotic phenomena based on the action of diffusing substances produced by the genes, the "evocators", and on the alteration of the normal speed of maturation of the imaginai discs equally due to the activity of the genes, could not be proved and therefore should be abandoned. In the same situation is any other explanation like that of Waddington or Villee considered as fundamentally identical to that of Goldschmidt. In order to clear the problem of homoeosis in terms which seem to put the phenomenon in complete agreement with the known facts the present writer elaborated a theory first published a few years ago (1941) based entirely on the assumption that the imaginai discs are specifically determined by some kind of substances, probably of chemical nature, contained in the cytoplam of the cells entering in the consti- tution of each individual disc. These substances already present in the blastem of the egg in which they are distributed in a definite order, pass to different cells at the time the blastem is transformed into blastoderm. These substances according to their organogenic potentiality may be called antenal-substance, legsubstance, wing-substance, eye-substance, etc. The hipoderm of the embryo resulting from the multiplication of the blastoderm cells would be constituted by a series of cellular areas differing from each other in their particular organoformative capacity. Thus the hypoderm giving rise to the imaginai discs, it follows that each disc must have the same organogenic power of the hypodermal area it came from. Therefore the discs i*re determinated since their origin by substances enclosed in the cytoplasm of their cells and consequently can no longer alter their potentiality. When an antennal disc develops into a leg one can conclude that this disc in spite of its position in the body of the larva is not, properly speaking, an antennal disc but a true leg disc whose cells instead of having in their cytoplasm the antennal substance derived from the egg blastem have in its place the leg-substance. Now, if a disc produces a tarsus or an antenna or even a compound appendage partly tarsus-like, partly antenna-like, it follows tha,t both tarsal and antennal substances are present in it. The ultimate aspect of the compound structure depends upon the reaction of each kind of substance to the different causes influencing development. For instance, temperature may orient the direction of development either lowards arista or tarsus, stimulating, or opposing to the one or the other of these substances. Confering to the genes the faculty of altering the constitution of the substances containing in the cytoplasm forming the egg blastem or causing transposition of these substances from one area to another or promoting the substitution of a given substance by a different one, the hereditary homoeocis may be easily explained. However, in the opinion of the present writer cytoplasm takes the initiative in all developmental process, provoking the chromosomes to react specifically and proportionally. Accordingly, the mutations causing homoeotic phenomena may arise independently at different rime in the cytoplasm and in the chromosomes. To the part taken by the chromosomes in the manifestation of the homoeotic characters is due the mendalian ratio observed in homoeotic X normal crosses. Expression, in itself, is mainly due to the proportion of the different substances in the cells of the affected discs. Homoeotic phenomena not presenting mendelian ratio may appear as consequence of cytoplasmic mutation not accompanied by chromosomal mutation. The great variability in the morphology of the homoeotic characteres, some individual being changed towards an extreme expression of the mutant phenotype while others in spite of their homozigous constitution cannot be distinguished from the normal ones, strongly supports the interpretation based on the relative proportion of the determining substances in the discs. To the same interpretation point also asymetry and other particularities observed in the exteriorization of the phenomenon. In conformity with this new conception homoeosis should not prove homology of Insect appendages (Villee 1942) since a more replacement of substances may cause legs to develop in substitution of the wings, as it was already observed (requiring confirmation in the opinion of Bateson 1894, p. 184) and no one would conclude for the homology of these organs in the usual meaning of the term.

Adenocarcinoma cístico hemorrágico da glândula mamária de camondongo

The A. A. have observed a hemorrhagic cyst-adenocacinoma of the mammary gland of mouse. This malignant tumor shows atipical, it is composed almost entirely of large cuboidal epithelial cells, which possess eosinophilic cytoplasm and generally hyperchromatic nuclei. There is a acinouslike structure. One can find many hemorragic areas, which form cyst-like blood filled spaces.

Hemângio-retículo-endotelioma do pericárdio

The author presents a case of primitive hemangio-reticulo-endothelioma of the pericardium. The structure of the tumor is identical to that of cases reported as primitive of the heart, and similar to that of the hemorrhagic sarcoma of KAPOSI, without, however, the typical cutaneous lesion of the disease.

Patogenesis of pipe-stem fibrosis of the liver (experimental observation on murine Schistosomiasis)

Mice infected with 30 cercariae of Schistosoma mansoni developed portal and septal fibrosis due to the massive and concentrated deposition of eggs in the periportal areas which occurred following the 16th week after infection. The lesion resembled pipe-stem fibrosis seen in human hepatosplenic schistosomiasis in the following characters: portal fibrosis interconnecting portal spaces as well as portal spaces and central canals; portal inflammation; periovular granulomas; vascular obstruction and telangiectasia. The liver parenchyma maintained its normal architecture. Vascular injection techniques with Indian ink and vinylite revealed that the portal system developed numerous dilated collateral venules coming from the large and medium-sized portal branches, about 10 weeks after schistosome infection. The lodging of schistosome eggs into these collaterals resulted in granulomatous inflammation and fibrosis along all the portal tracts, thus forming the pipe-stem lesion. Although not readily demonstrable grossly, the pipe-stem fibrosis of murine schistosomiasis has many similarities with the human lesion and can be considered to have the same basic pathogenesis.

NR2E3 mutations in enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), clumped pigmentary retinal degeneration (CPRD), and retinitis pigmentosa (RP).

NR2E3, also called photoreceptor-specific nuclear receptor (PNR), is a transcription factor of the nuclear hormone receptor superfamily whose expression is uniquely restricted to photoreceptors. There, its physiological activity is essential for proper rod and cone photoreceptor development and maintenance. Thirty-two different mutations in NR2E3 have been identified in either homozygous or compound heterozygous state in the recessively inherited enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), and clumped pigmentary retinal degeneration (CPRD). The clinical phenotype common to all these patients is night blindness, rudimental or absent rod function, and hyperfunction of the "blue" S-cones. A single p.G56R mutation is inherited in a dominant manner and causes retinitis pigmentosa (RP). We have established a new locus-specific database for NR2E3 (www.LOVD.nl/eye), containing all reported mutations, polymorphisms, and unclassified sequence variants, including novel ones. A high proportion of mutations are located in the evolutionarily-conserved DNA-binding domains (DBDs) and ligand-binding domains (LBDs) of NR2E3. Based on homology modeling of these NR2E3 domains, we propose a structural localization of mutated residues. The high variability of clinical phenotypes observed in patients affected by NR2E3-linked retinal degenerations may be caused by different disease mechanisms, including absence of DNA-binding, altered interactions with transcriptional coregulators, and differential activity of modifier genes.

Sclérodermie et risques oncologiques [Systemic sclerosis and cancer]

The combination of skin induration with clinical features such as dyspnea, facial telangiectasia, digital infarctions and/or dysphagia supports the diagnosis of systemic sclerosis. The oesophageal dysmotility is associated with symptoms which may delay the diagnosis of gastro-oesophageal cancer. Herein we report a case of long standing systemic sclerosis with heartburn and dysphagia symptoms which were monitored closely. Unfortunately, these symptoms delayed the diagnosis of gastric adenocarcinoma. This case prompted us to review the evidence of the association of cancer and systemic sclerosis and if any oncologic evaluation is required during the follow-up of patients affected with systemic sclerosis.

Pseudohypoaldosteronisms, report on a 10-patient series.

BACKGROUND: Type 1 pseudohypoaldosteronism (PHA1) is a salt-wasting syndrome caused by mineralocorticoid resistance. Autosomal recessive and dominant hereditary forms are caused by Epithelial Na Channel and Mineralocorticoid Receptor mutation respectively, while secondary PHA1 is usually associated with urological problems. METHODS: Ten patients were studied in four French pediatric units in order to characterize PHA1 spectrum in infants. Patients were selected by chart review. Genetic, clinical and biochemistry data were collected and analyzed. RESULTS: Autosomal recessive PHA1 (n = 3) was diagnosed at 6 and 7 days of life in three patients presenting with severe hyperkalaemia and weight loss. After 8 months, 3 and 5 years on follow-up, neurological development and longitudinal growth was normal with high sodium supplementation. Autosomal dominant PHA1 (n = 4) was revealed at 15, 19, 22 and 30 days of life because of failure to thrive. At 8 months, 3 and 21 years of age, longitudinal growth was normal in three patients who were given salt supplementation; no significant catch-up growth was obtained in the last patient at 20 months of age. Secondary PHA1 (n = 3) was diagnosed at 11, 26 days and 5 months of life concomitantly with acute pyelonephritis in three children with either renal hypoplasia, urinary duplication or bilateral megaureter. The outcome was favourable and salt supplementation was discontinued after 3, 11 and 13 months. CONCLUSIONS: PHA1 should be suspected in case of severe hyperkalemia and weight loss in infants and need careful management. Pathogenesis of secondary PHA1 is still challenging and further studies are mandatory to highlight the link between infection, developing urinary tract and pseudohypoaldosteronism.

Selection of patients with germline MLH1 mutated Lynch syndrome by determination of MLH1 methylation and BRAF mutation.

Lynch syndrome is one of the most common hereditary colorectal cancer (CRC) syndrome and is caused by germline mutations of MLH1, MSH2 and more rarely MSH6, PMS2, MLH3 genes. Whereas the absence of MSH2 protein is predictive of Lynch syndrome, it is not the case for the absence of MLH1 protein. The purpose of this study was to develop a sensitive and cost effective algorithm to select Lynch syndrome cases among patients with MLH1 immunohistochemical silencing. Eleven sporadic CRC and 16 Lynch syndrome cases with MLH1 protein abnormalities were selected. The BRAF c.1799T> A mutation (p.Val600Glu) was analyzed by direct sequencing after PCR amplification of exon 15. Methylation of MLH1 promoter was determined by Methylation-Sensitive Single-Strand Conformation Analysis. In patients with Lynch syndrome, there was no BRAF mutation and only one case showed MLH1 methylation (6%). In sporadic CRC, all cases were MLH1 methylated (100%) and 8 out of 11 cases carried the above BRAF mutation (73%) whereas only 3 cases were BRAF wild type (27%). We propose the following algorithm: (1) no further molecular analysis should be performed for CRC exhibiting MLH1 methylation and BRAF mutation, and these cases should be considered as sporadic CRC; (2) CRC with unmethylated MLH1 and negative for BRAF mutation should be considered as Lynch syndrome; and (3) only a small fraction of CRC with MLH1 promoter methylation but negative for BRAF mutation should be true Lynch syndrome patients. These potentially Lynch syndrome patients should be offered genetic counselling before searching for MLH1 gene mutations.