Coexistent HCN4 and GATA5 rare variants and Atrial Fibrillation in a large Spanish Family

BACKGROUND

Familial association of atrial fibrillation (AF) can involve single gene variants related to known arrhythmogenic mechanisms; however, genome-wide association studies often disclose complex genetic variants in familial and non-familial AF, making it difficult to relate to known pathogenetic mechanisms.

METHODS

The finding of 4 siblings with AF led to studying 47 members of a family. Long-term Holter monitoring (298 hours average) ruled out silent AFWhole-exome sequencing was performed and variants shared by the index cases were filtered and prioritized according to current recommendations. HCN4 currents (IHCN4) were recorded in Chinese hamster ovary cells expressing human p.P1163H and/or native Hcn4 channels using the patch-clamp technique and topologically associated domain analysis of GATA5 variant carriers were performed.

RESULTS

The clinical study diagnosed 2 more AF cases. Five family members carried the heterozygous p.P1163H, HCN4 variant, 14 the intronic 20,61040536,G,A GATA5 rare variant, and 9 carried both variants (HCN4+GATA5). Five of the 6 AF cases (onset age ranging 33-70 years) carried both variants and one the GATA5 variant alone. Multivariate analysis showed that the presence of HCN4+GATA5 variants significantly and independently increased AF risk [OR=32.740 (1.812-591.408)] and not age, hypertension or overweight. Functional testing showed that IHcn4 generated by heterozygous p.P1163H were normal. Topologically associating domain analysis suggested that GATA5 could affect the expression of many genes, including those encoding microRNA-1.

CONCLUSION

The coincidence of two rare gene variants was independently associated with AF, but functional studies do not allow the postulation of the arrhythmogenic mechanism(s) involved.

Electrosurgery in patients with implantable electronic cardiac devices (pacemakers and defibrillators)

The electrosurgical unit is a very useful tool widely used in dermatology to treat benign and malignant skin lesions and to achieve hemostasis during surgery. However, precautions are required when this technique is used in patients with implantable electronic cardiac devices (IECD), such as pacemakers and defibrillators, because electromagnetic interference produced by the tool may cause such devices to malfunction. Before using electrosurgery in patients with IECDs, it is essential to ascertain the type of implanted device and the patient's level of dependence on it. The location of the skin lesion to be treated with respect to the device should also be assessed. Bipolar pacemakers are more resistant to interference. Appropriate monitoring and the use of bipolar forceps are recommended.

Evaluation of monocytes as carriers for armed oncolytic adenoviruses in murine and Syrian hamster models of cancer

Replication-competent (oncolytic) adenoviruses (OAV) can be adapted as vectors for the delivery of therapeutic genes, with the aim of extending the antitumor effect beyond direct cytolysis. Transgene expression using these vectors is usually intense but short-lived, and repeated administrations are hampered by the rapid appearance of neutralizing antibodies (NAbs). We have studied the performance of monocytes as cell carriers to improve transgene expression in cancer models established in athymic mice and immunocompetent Syrian hamsters. Human and hamster monocytic cell lines (MonoMac6 and HM-1, respectively) were loaded with replication-competent adenovirus-expressing luciferase. Intravenous administration of these cells caused a modest increase in transgene expression in tumor xenografts, but this effect was virtually lost in hamsters. In contrast, intratumoral administration of HM-1 cells allowed repeated cycles of expression and achieved partial protection from NAbs in preimmunized hamsters bearing pancreatic tumors. To explore the therapeutic potential of this approach, HM-1 cells were loaded with a hypoxia-inducible OAV expressing the immunostimulatory cytokine interleukin-12 (IL-12). Three cycles of treatment achieved a significant antitumor effect in the hamster model, and transgene expression was detected following each administration, in contrast with the rapid neutralization of the free virus. We propose monocytes as carriers for multiple intratumoral administrations of armed OAVs.

Anti-inflammatory, antioxidant and antifungal activity of Chuquiraga spinosa

CONTEXT

Stem and leaves infusion of Chuquiraga spinosa (R&P) Don. (Asteraceae) is used in the Peruvian traditional medicine for its anti-inflammatory properties and for the treatment of vaginal infections.

OBJECTIVE

This study evaluated the antioxidant, anti-inflammatory and antifungal activities of C. spinosa for the first time.

MATERIALS AND METHODS

Extracts of methanol, 50% methanol and water were obtained from C. spinosa aerial parts. Antioxidant activity of the extracts was evaluated (DPPH˙, ABTS˙(+) and superoxide radical-scavenging activity). The correlation between these results and total polyphenolic content was determined by Pearson's Correlation Coefficient. Anti-inflammatory activity of 50% methanol extract was evaluated with the rat model of carrageenan-induced acute inflammation and mouse model of TPA-induced acute inflammation. The antifungal activity of the extracts against Cladosporium cucumerinum and Candida albicans was studied by direct bioautography, and antifungal activity against phytopathogenic fungi was performed by culture in potato dextrose agar plates.

RESULTS

All the extracts showed high antioxidant activity, and there was correlation between the activity and total polyphenolic compounds. As 50% methanol extract was administered orally, the paw edema in rats was reduced significantly (52.5%). This extract, by topical administration, produced a reduction of 88.07% of the edema TPA-induced in ear of mice. The aqueous and 50% methanol extracts were active against C. albicans (minimum inhibitory concentration of 2.5 and 6.25 µg, respectively). The aqueous extract showed antifungal activity against C. cucumerinum (MIC: 2.5 µg).

DISCUSSION AND CONCLUSION

Preliminary phytochemical screening and the analysis of the three extracts by high-performance liquid chromatography diode-array detection showed the majority compounds are flavonoids and phenolic acid derivatives. These compounds may be responsible of the radical-scavenging activity of these extracts as well as responsible of anti-inflammatory effect in vivo of 50% methanol extract. Several authors have demonstrated the antioxidant and anti-inflammatory properties of some flavonoids and phenolic acids. The antifungal activity of the extracts obtained from aerial parts of C. spinosa has been investigated here for the first time. Other studies are necessary to determine the mechanism of action and to identify the bioactive compounds of this plant.

Anti-inflammatory and antioxidant activities of Jungia paniculata

The present study was conducted to evaluate the antioxidant and anti-inflammatory activities of Jungia paniculata (DC.) A. Gray (Asteraceae), used traditionally in Peru. The dry leaves were extracted with methanol, 50% methanol, and water. The anti-inflammatory activity of this plant was studied using in vitro (nitric oxide production in RAW 264.7 macrophages and sPLA(2) inhibition assay) and in vivo (carrageenan-induced paw edema in rats and TPA-induced ear edema in mice) model systems. The antioxidant activity of extracts was studied using three in vitro model systems (DPPH(*) radical-scavenging assay, ABTS(*+) assay, and superoxide radical-scavenging activity). The results have been correlated with total phenolics and total flavonoids contents. In the NO test of the extracts of Jungia paniculata, no significant cytotoxicities were observed at the concentrations determined by MTT assay. Only the MeOH50 extract of Jungia paniculata significantly inhibited PLA(2) enzyme activity (82.3 +/- 2.6%). At 3 h, the 50% methanol extract of Jungia paniculata at an oral dose of 500 mg/kg showed significant suppression of carrageenan-induced rat paw edema (36.36%). The same extract induced a 93.99% reduction in TPA-induced edema in topical administration. The extracts exhibited a high antioxidant activity and contained high total levels of polyphenols and flavonoids. There was a significant linear correlation between total phenolics and flavonoids contents and antioxidant activity in the three models used. In conclusion, Jungia paniculata possesses anti-inflammatory and antioxidant properties, which confirm the use of this plant in folk medicine as a topical anti-inflammatory herbal.

Identification and Quantification of Flavonoids from Chuquiraga spinosa (Asteraceae)

Nine flavonol glycosides (quercetin-3-O-glucuronide, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, kaemperol-3-O-glucuronide, kaemperol-3-O-rutinoside, kaempherol-3-O-glucoside, isorhamnetin-3-O-glucuronide, isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside) were isolated from the aerial parts of Chuquiraga spinosa (R. et P.) D. Don (Asteraceae). The identification of the compounds was carried out by HPLC/DAD, HPLC/MS and NMR analysis. These compounds may be useful in the chemotaxonomy of the genus and species.

Identification and quantification of flavonoids from Chuquiraga spinosa (Asteraceae)

Nine flavonol glycosides (quercetin-3-O-glucuronide, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, kaemperol-3-O-glucuronide, kaemperol-3-O-rutinoside, kaempherol-3-O-glucoside, isorhamnetin-3-O-glucuronide, isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside) were isolated from the aerial parts of Chuquiraga spinosa (R. et P.) D. Don (Asteraceae). The identification of the compounds was carried out by HPLC/DAD, HPLC/MS and NMR analysis. These compounds may be useful in the chemotaxonomy of the genus and species.

Liver cirrhosis in HIV-infected patients: prevalence, aetiology and clinical outcome

Liver disease is frequently seen in HIV+ patients as a result of coinfection with hepatitis B (HBV) or C (HCV) viruses, alcohol abuse and/or exposure to hepatotoxic drugs. The aim of this study was to assess the prevalence of liver cirrhosis, its main causes and clinical presentation in HIV+ patients. Observational, cross-sectional, retrospective study of all HIV+ individuals followed at one reference HIV outpatient clinic in Madrid. Liver fibrosis was measured in all cases using transient elastometry (FibroScan). All 2168 HIV+ patients on regular follow-up (76% males, 46% injecting drug users) were successfully examined by FibroScan) between October 2004 and August 2006. Liver cirrhosis was recognized in 181 (overall prevalence, 8.3%), and the main aetiologies were HCV, 82.3%; HBV, 1.6%; dual HBV/HCV, 2.8%; and triple HBV/HCV/ hepatitis delta virus (HDV) infection, 6.6%. The prevalence of cirrhosis differed among patients with distinct chronic viral hepatitis: HCV, 19.2%; HBV, 6.1%; HBV/HCV, 41.7%; and HBV/HCV/HDV, 66.7%. In 12 patients with cirrhosis (6.7%), no definite aetiology was recognized. Overall, cirrhotics had lower mean CD4 counts than noncirrhotics (408 vs 528 cells/microL respectively; P = 0.02), despite similar proportion of subjects with undetectable viraemia on highly active antiretroviral therapy. Clinical manifestations of liver cirrhosis were: splenomegaly, 61.5%; oesophageal varices, 59.8%; ascites, 22.6%; encephalopathy, 12.1%; and variceal bleeding, 6.1%. Liver cirrhosis and hepatic decompensation events are relatively frequent in HIV+ individuals. Chronic HCV and alcohol abuse, but not chronic HBV, play a major role. Transient elastometry may allow the identification of a significant number of HIV+ individuals with asymptomatic liver cirrhosis.

Recovery of gallium and vanadium from gasification fly ash

The Puertollano Integrated Coal Gasification Combined Cycle (IGCC) Power Plant (Spain) fly ash is characterized by a relatively high content of Ga and V, which occurs mainly as Ga2O3 and as Ga3+ and V3+ substituting for Al3+ in the Al-Si fly ash glass matrix. Investigations focused on evaluating the potential recovery of Ga and V from these fly ashes. Several NaOH based extraction tests were performed on the IGCC fly ash, at different temperatures, NaOH/fly ash (NaOH/FA) ratios, NaOH concentrations and extraction times. The optimal Ga extraction conditions was determined as 25 degrees C, NaOH 0.7-1 M, NaOH/FA ratio of 5 L/kg and 6 h, attaining Ga extraction yields of 60-86%, equivalent to 197-275 mg of Ga/kg of fly ash. Re-circulation of leachates increased initial Ga concentrations (25-38 mg/L) to 188-215 mg/L, while reducing both content of impurities and NaOH consumption. Carbonation of concentrated Ga leachate demonstrated that 99% of the bulk Ga content in the leachate precipitates at pH 7.4. At pH 10.5 significant proportions of impurities, mainly Al (91%), co-precipitate while >98% of the bulk Ga remains in solution. A second carbonation of the remaining solution (at pH 7.5) recovers the 98.8% of the bulk Ga. Re-dissolution (at pH 0) of the precipitate increases Ga purity from 7 to 30%, this being a suitable Ga end product for further purification by electrolysis. This method produces higher recovery efficiency than currently applied for Ga on an industrial scale. In contrast, low V extraction yields (<64%) were obtained even when using extreme alkaline extraction conditions, which given the current marked price of this element, limits considerably the feasibility of V recovery from IGCC fly ash.

CT and MR imaging findings in methanol intoxication

We present the CT and MR imaging findings in acute methanol intoxication in a 35-year-old man who was admitted to the emergency department with weakness, blurred vision, mild bilateral areactive mydriasis, and a progressive decrease in the level of consciousness. CT and MR imaging showed bilateral putaminal hemorrhagic necrosis and subcortical white matter lesions with peripheral contrast enhancement. There was only partial improvement in patient's Glasgow Coma Scale score during follow-up.

Organometallic Gold(III) Compounds as Catalysts for the Addition of Water and Methanol to Terminal Alkynes

Different inorganic and organometallic gold(III) and gold(I) complexes have been tested in the addition of water and methanol to terminal alkynes. Anionic and neutral organometallic gold(III) compounds can efficiently mediate these reactions in neutral media in refluxing methanol. The compounds are added in catalytic amounts (1.6-4.5 mol % with respect to the alkyne). Thus, compounds of the general formula Q[AuRCl(3)], Q[AuR(2)Cl(2)], [AuRCl(2)](2), and [AuR(2)Cl](2) (Q = BzPPh(3)(+), PPN: N(PPh(3))(2)(+) or N(Bu)(4)(+); R = C(6)F(5) or 2,4,6-(CH(3))(3)C(6)H(2)) seem to behave as Lewis acids in nucleophilic additions to triple bonds. Some intermediates could be detected in the stoichiometric reaction between [Au(C(6)F(5))(2)Cl](2) and phenylacetylene that was followed by variable temperature (1)H, (19)F[(1)H], COSY (19)F[(1)H]-(19)F[(1)H], and (2)H[(1)H] NMR experiments. Compound [Au(C(6)F(5))(2)Cl](2) is also able to catalyze the hydration of phenylacetylene at room temperature. A plausible mechanism for the hydration reaction has been proposed.

Heterologous expression of a plant small heat-shock protein enhances Escherichia coli viability under heat and cold stress

A small heat-shock protein (sHSP) that shows molecular chaperone activity in vitro was recently purified from mature chestnut (Castanea sativa) cotyledons. This protein, renamed here as CsHSP17. 5, belongs to cytosolic class I, as revealed by cDNA sequencing and immunoelectron microscopy. Recombinant CsHSP17.5 was overexpressed in Escherichia coli to study its possible function under stress conditions. Upon transfer from 37 degrees C to 50 degrees C, a temperature known to cause cell autolysis, those cells that accumulated CsHSP17.5 showed improved viability compared with control cultures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of cell lysates suggested that such a protective effect in vivo is due to the ability of recombinant sHSP to maintain soluble cytosolic proteins in their native conformation, with little substrate specificity. To test the recent hypothesis that sHSPs may be involved in protection against cold stress, we also studied the viability of recombinant cells at 4 degrees C. Unlike the major heat-induced chaperone, GroEL/ES, the chestnut sHSP significantly enhanced cell survivability at this temperature. CsHSP17.5 thus represents an example of a HSP capable of protecting cells against both thermal extremes. Consistent with these findings, high-level induction of homologous transcripts was observed in vegetative tissues of chestnut plantlets exposed to either type of thermal stress but not salt stress.

Site-directed mutagenesis of active site residues in a class I endochitinase from chestnut seeds

Despite the intensive research on plant chitinases, largely bolstered by their antifungal properties, little is known at present about the structure-activity relationships of these enzymes. Here we report the identification of essential active site residues in endochitinase Ch3, a class I enzyme abundant in chestnut seeds. Knowledge-based protein modeling as well as structural and sequence comparisons were performed to identify potential catalytic residues. Different mutated proteins were then generated by site-directed mutagenesis, expressed in Escherichia coli , and characterized for their chitinolytic activity. Glu124 and Glu146, the only carboxylic residues properly located into the active site cleft to participate in catalysis, were both mutated to Gln and Asp. Our results suggest that Glu124 functions as the general acid catalyst whereas Glu146 is likely to act as a general base. Other mutations involving three highly conserved active site residues, Gln173, Thr175, and Asn254, also impaired the chitinolytic activity of Ch3. The effects of these variants on the fungus Trichoderma viride revealed that catalysis is not necessary for antifungal activity. Similarly to its homologous nonenzymatic polypeptides hevein and stinging nettle lectin, the N-terminal chitin-binding domain of Ch3 appears to interfere itself with hyphal growth.

Purification and in vitro chaperone activity of a class I small heat-shock protein abundant in recalcitrant chestnut seeds

A 20-kD protein has been purified from cotyledons of recalcitrant (desiccation-sensitive) chestnut (Castanea sativa) seeds, where it accumulates at levels comparable to those of major seed storage proteins. This protein, termed Cs smHSP 1, forms homododecameric complexes under nondenaturing conditions and appears to be homologous to cytosolic class I small heat-shock proteins (smHSPs) from plant sources. In vitro evidence has been obtained that the isolated protein can function as a molecular chaperone; it increases, at stoichiometric levels, the renaturation yields of chemically denatured citrate synthase and also prevents the irreversible thermal inactivation of this enzyme. Although a role in desiccation tolerance has been hypothesized for seed smHSPs, this does not seem to be the case for Cs smHSP 1. We have investigated the presence of immunologically related proteins in orthodox and recalcitrant seeds of 13 woody species. Our results indicate that the presence of Cs smHSP 1-like proteins, even at high levels, is not enough to confer desiccation tolerance, and that the amount of these proteins does not furnish a reliable criterion to identify desiccation-sensitive seeds. Additional proteins or mechanisms appear necessary to keep the viability of orthodox seeds upon shedding.

Bacterial expression of an active class Ib chitinase from Castanea sativa cotyledons

Ch3, an endochitinase of 32 kDa present in Castanea sativa cotyledons, showed in vitro antifungal properties when assayed against Trichoderma viride. The characterization of a cDNA clone corresponding to this protein indicated that Ch3 is a class Ib endochitinase that is synthesized as a preprotein with a signal sequence preceding the mature polypeptide. Bacterial expression of mature Ch3 fused to the leader peptide of the periplasmic protein ompT resulted in active Ch3 enzyme. A plate assay was adapted for semi-quantitative determination of chitinase activity secreted from cultured bacteria, which should facilitate the identification of mutants with altered capacity to hydrolyse chitin.

Electrophoretic analysis of seed storage proteins from gymnosperms

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), pore gradient gel electrophoresis (PGGE) followed by SDS-PAGE and Western blot analysis were used to characterize the seed storage proteins from seven gymnosperm species from the families Pinaceae (Abies alba, Cedrus atlantica and Picea abies), Cupressaceae (Biota orientalis, Chamaecyparis lawsoniana and Cupressus arizonica), and Taxaceae (Taxus baccata). SDS-PAGE and PGGE X SDS-PAGE indicate the presence of proteins with characteristics similar to the 7S globulins in all the species studied. Antibodies to a 7S globulin subunit from Pinus pinaster cross-reacted with homologous polypeptides from Pinaceae species, but not with corresponding subunits from species belonging to other families. Also detected in each of the studied species, with the exception of A. alba and T. baccata, were those of C. atlantica may be extracted by saline buffer, while the remainder require a dissociating agent. Antibodies raised against the small subunit from P. pinaster 11S protein recognized only the corresponding polypeptides from Pinaceae species. Overall, these results help clarify our knowledge of gymnosperm seed storage proteins.

Biochemical genetics of a 7S globulin-like protein from Pinus pinaster seed

The megagametophytes of seeds of Pinus pinaster Ait. contain two types of oligomeric globulins of approximately 175 and 190 kDa that are comprised of 47-kDa and 27- and 22-kDa, monomers, respectively, joined by weak interactions. The 27- and 22-kDa components were purified and their N-terminal sequences determined. Both polypeptides were inherited as if they were coded by a single unit of recombination. The results obtained suggest that these two polypeptides originate from a single protein that undergoes proteolytic processing. The characteristics of this P. pinaster globulin indicate that it is a member of the 7S globulin family of seed storage proteins.

2S Arginine-rich proteins from Pinus pinaster seeds

Low molecular weight globulins, which are abundant proteins in the Pinus pinaster Ait. megagametophyte, were purified and characterized. They showed a dimeric structure formed of one large and one small subunit linked by disulfide bridges. They were characterized by a high Arg and Glx content and by a relatively high Cys content. A comparison of their characteristics with those of angiosperm 2S proteins suggests that there is homology between them.

Basic Endochitinases Are Major Proteins in Castanea sativa Cotyledons

Basic endochitinases are abundant proteins in Castanea sativa Mill. cotyledons. Three basic chitinases were purified with molecular masses of 25, 26, and 32 kD (Ch1, Ch2, and Ch3) and with isoelectric points between 8 and 9.5. Antibodies raised against Ch1 cross-reacted with Ch2 and Ch3. However, Ch3 showed differences when compared with the other two enzymes, especially in its higher cysteine content. The size, amino acid composition, and N-terminal sequence of Ch1 indicate that it is a class II endochitinase and, therefore, has no cysteine-rich hevein domain. Ch1 inhibits the growth of the fungus Trichoderma viride. The biological role of these endochitinases is discussed.

[Immunologic responses following surgical resection of gastrointestinal carcinomas]

The amount of IgG, IgM, IgA, C3, C4 and C5 in serum, and the response to delayed hypersensitivity tests with PPD, varidase, candidin and mumps antigens were estimated in patients submitted to radical surgery for gastric and colorectal cancer (group I), before and at intervals after the operation was performed, and compared with cancer patients undergoing palliative abdominal surgery (group II), and with patients submitted to major abdominal surgery for diseases other than cancer (group III). Group I showed a decrease of all the immunoglobulins (Igs) and complement fractions (F) during the first week after operation, and a significant increase after one month. Similar changes were observed in group III, the augmentation of Igs and F after one month being somewhat smaller. Group II showed a larger number of positiveness than either group I or II in both the preoperative and early postoperative periods (p = 0.001). After 2 and 3 months, the number of positive cases was larger in group I than in group II (p = 0.05). According to these results, the immune response is recovered one month after the excision of gastric and colorectal malignant tumors, being this the best moment to receive a complementary cytoreductive therapy.