Synergistic activation of AMPK prevents from polyglutamine-induced toxicity in Caenorhabditis elegans.

Expression of abnormally long polyglutamine (polyQ) tracks is the source of a range of dominant neurodegenerative diseases, such as Huntington disease. Currently, there is no treatment for this devastating disease, although some chemicals, e.g., metformin, have been proposed as therapeutic solutions. In this work, we show that metformin, together with salicylate, can synergistically reduce the number of aggregates produced after polyQ expression in Caenorhabditis elegans. Moreover, we demonstrate that incubation polyQ-stressed worms with low doses of both chemicals restores neuronal functionality. Both substances are pleitotropic and may activate a range of different targets. However, we demonstrate in this report that the beneficial effect induced by the combination of these drugs depends entirely on the catalytic action of AMPK, since loss of function mutants of aak-2/AMPKα2 do not respond to the treatment. To further investigate the mechanism of the synergetic activity of metformin/salicylate, we used CRISPR to generate mutant alleles of the scaffolding subunit of AMPK, aakb-1/AMPKß1. In addition, we used an RNAi strategy to silence the expression of the second AMPKß subunit in worms, namely aakb-2/AMPKß2. In this work, we demonstrated that both regulatory subunits of AMPK are modulators of protein homeostasis. Interestingly, only aakb-2/AMPKß2 is required for the synergistic action of metformin/salicylate to reduce polyQ aggregation. Finally, we showed that autophagy acts downstream of metformin/salicylate-related AMPK activation to promote healthy protein homeostasis in worms.

Extended phenotype and clinical subgroups in unilateral Meniere disease: A cross-sectional study with cluster analysis.

OBJECTIVES: To define clinical subgroups by cluster analysis in patients with unilateral Meniere disease (MD) and to compare them with the clinical subgroups found in bilateral MD. DESIGN: A cross-sectional study with a two-step cluster analysis. SETTINGS: A tertiary referral multicenter study. PARTICIPANTS: Nine hundred and eighty-eight adult patients with unilateral MD. MAIN OUTCOME MEASURES: best predictors to define clinical subgroups with potential different aetiologies. RESULTS: We established five clusters in unilateral MD. Group 1 is the most frequently found, includes 53% of patients, and it is defined as the sporadic, classic MD without migraine and without autoimmune disorder (AD). Group 2 is found in 8% of patients, and it is defined by hearing loss, which antedates the vertigo episodes by months or years (delayed MD), without migraine or AD in most of cases. Group 3 involves 13% of patients, and it is considered familial MD, while group 4, which includes 15% of patients, is linked to the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by a comorbid AD. We found significant differences in the distribution of AD in clusters 3, 4 and 5 between patients with uni- and bilateral MD. CONCLUSIONS: Cluster analysis defines clinical subgroups in MD, and it extends the phenotype beyond audiovestibular symptoms. This classification will help to improve the phenotyping in MD and facilitate the selection of patients for randomised clinical trials.

Effects of endocrine disorders on maxillary and mandibular growth in Colombian children and adolescents: a cross-sectional study.

OBJECTIVE: To establish the influence of overweight/obesity, medicated hypothyroidism, and medicated non-syndromic hypogrowth on maxillary and mandibular growth. MATERIALS AND METHODS: The relation between 10 craniofacial anthropometric measurements and hypothyroidism (n = 216), overweight/obesity (n = 108), and non-syndromic hypogrowth (n = 250) were evaluated in patients aged 1-19 years and a control group of healthy patients (n = 587). A subgroup analysis was performed at the peak growth in all groups. RESULTS: Patients with overweight/obesity and hypothyroidism showed increased craniofacial growth, while hypogrowth patients showed differences in zygomatic width and nasal base growth. Females with hypothyroidism and non-syndromic hypogrowth showed decreased head circumference at peak growth. Several anthropometric measurements were increased in patients with overweight/obesity, including head circumference. When all age groups were analyzed, overweight/obese and hypothyroidism patients showed increased zygomatic width while decreased hypogrowth. Overall, most craniofacial anthropometric measurements in overweight/obese patients were increased. Finally, the peak growth in males with hypothyroidism and subjects with non-syndromic hypogrowth was delayed compared to the control group (p < 0.05). CONCLUSIONS: Children and adolescents with overweight/obesity and endocrine disorders showed alterations in craniofacial growth. Clinicians must be aware that the growth peak in these patients may be delayed when planning maxillary and mandibular orthopedic treatment.

Metformin to treat Huntington disease: A pleiotropic drug against a multi-system disorder.

Huntington disease (HD) is a neurodegenerative disorder produced by an expansion of CAG repeats in the HTT gene. Patients of HD show involuntary movements, cognitive decline and psychiatric impairment. People carrying abnormally long expansions of CAGs (more than 35 CAG repeats) produce mutant huntingtin (mHtt), which encodes tracks of polyglutamines (polyQs). These polyQs make the protein prone to aggregate and cause it to acquire a toxic gain of function. Principally affecting the frontal cortex and the striatum, mHtt disrupts many cellular functions. In addition, this protein is expressed ubiquitously, and some reports show that many other cell types are affected by the toxicity of mHtt. Several studies reported that metformin, a widely-used anti-diabetic drug, is neuroprotective in models of HD. Here, we provide a review of the benefits of this substance to treat HD. Metformin is a pleiotropic drug, modulating different targets such as AMPK, insulin signalling and many others. These molecules regulate autophagy, chaperone expression, and more, which in turn reduce mHtt toxicity. Moreover, metformin alters gut microbiome and its metabolic processes. The study of potential targets, interactions between the drug, host and microbiome, or genomic and pharmacogenomic approaches may allow us to design personalised medicine to treat HD.

Renal failure as a determinant of mortality after cardiac transplantation.

INTRODUCTION: Patients with heart failure frequently develop renal failure, which increases the mortality rate among patients undergoing cardiac transplantation. PURPOSE: To determine whether preoperative renal function influenced postoperative mortality in cardiac transplantation recipients. MATERIALS AND METHODS: The measurements of plasma urea, plasma creatinine, and 24-hour creatinine clearance in patients who underwent cardiac transplantation were correlated with mortality at 30, 90, and 365 days after the procedure, using Student t test for continuous variables and the chi-square test for categorical variables. RESULTS: All variables correlated with mortality, particularly plasma creatinine at 30, 90, and 365 days (P =.029,.003, and.0029, respectively). CONCLUSION: Preoperative renal failure is a mortality indicator in cardiac transplantation recipients.

Platelet resistance to prostacyclin. Enhancement of the antiaggregatory effect of prostacyclin by pentoxifylline.

With regard to existence of high prostacyclin (PGI2) levels during atheromatosis and thrombus formation, resistance of platelets to prostacyclin and its analogues seems to play an important pathophysiologic key role for the clarifying of vasoocclusive phenomena. Platelet resistance to prostacyclin was studied in vitro and ex vivo in 160 atherosclerotic patients (assessed by objective diagnostic criteria) with and without thrombotic complications and in 50 controls. Prostacyclin resistance phenomena were more pronounced and frequent in patients with occlusive complications, the difference from controls being statistically significant. However, there was no significant difference between the controls and the nonthrombotic patient sample. The intraplatelet cAMP levels might be the metabolic basis of the PGI2 resistance phenomenon, because in the patient group, platelet cAMP levels were decreased by 50% after Ca2+ stimulation. Compared to controls beta-thromboglobulin and thromboxane B2 plasma levels were significantly increased (30 +/- 9 to 87 +/- 26 ng/ml and 9 +/- 5 to 54 +/- 21 pg/ml, respectively), confirming the hyperreactivity state of resistant platelets. From the therapeutic point of view, patients with resistant platelets require PGI2 doses that cause, however, increased side effects. We were able to demonstrate in vivo that IV pretreatment with pentoxifylline--a known stimulator of cAMP formation in platelets--followed by a simultaneous and continuous IV infusion of PGI2 + pentoxifylline, permitted us to reduce significantly the mean PGI2 doses needed for triggering an antiplatelet effect, without inducing side effects. In ex vivo studies, PGI2 resistant platelets of atherosclerotic patients pretreated with pentoxifylline showed normalized stimulation response, and platelet cAMP levels increased from 7.8 +/- 2.7 to 15.2 +/- 1.9 pmol/10(8) platelets.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of the determination of cyclosporin-A in blood samples collected on filter paper and by the ordinary technique]. / Comparação entre a dosagem de ciclosporina-A em amostras de sangue coletadas em papel de filtro e pela técnica habitual.

Monitoring cyclosporin-A (CsA) blood levels is of utmost importance for the rational use of this drug. Although many centers perform transplants, in Brazil there are few laboratories able to measure CsA blood levels. Therefore making blood samples reach the laboratory emerged as a problem. Collection of blood on filter paper has been a technique used for a long time in special cases. PURPOSE--To confirm the usefulness of measuring CsA blood levels in blood samples collected on filter paper and in the usual way. METHOD--We studied twenty renal cadaver kidney recipients who were receiving CsA, azathioprine and prednisone. Ninety five blood samples were collected and divided into two aliquots. One of them was sent routinely to one laboratory to perform whole blood CsA measurements. From the other aliquot, 20 microliters were pipetted on filter paper. When dried they were mailed to the other laboratory, where, after elution, CsA was measured. In both cases radioimmunoassay with polyclonal antibody was used. RESULTS--Linear correlation between both measurements revealed r = 0.81 with no statistical difference. CONCLUSION--The technique showed to be useful in clinical practice. In countries with continental size, as Brazil, it may be very helpful.

Ophthalmic features of Friedreich ataxia.

PURPOSE: To describe ocular abnormalities in patients with Friedreich ataxia (FRDA). METHODS: Patients diagnosed with FRDA by genetic analysis were invited to participate in a prospective cohort. The patients included underwent an extensive ophthalmologic examination, including low-contrast Sloan letter charts test and retinal nerve fiber layer (RNFL) thickness analysis by optical coherence tomography (OCT). RESULTS: Twenty-three patients agreed to participate. In all, 19 patients (83%) had a visual acuity of at least 0.8 in both eyes. Fundus examination showed diffuse optic nerve pallor in four patients. However, OCT showed a decreased mean peripapillary RNFL thickness in all but three adult cases and one teenager. The RNFL thickness was found to have a positive correlation with visual acuity (P=0.001) and contrast sensitivity (P=0.001) and a negative correlation with time elapsed from diagnosis (P=0.001). CONCLUSIONS: OCT and low contrast test sensitivity show that the visual pathway is affected in FRDA. However, in most patients there is no significant visual impairment. In a small proportion of patients visual acuity declines with disease progression. This study provides a better understanding of the ophthalmic features of FRDA.

Sickle cell anemia. Pathophysiological role of increased intracorpuscular calcium and changes during treatment with pentoxifylline.

In a group of 20 homozygous (SS) sickle cell patients (age range 8-28 years) determinations of red blood cell and platelet calcium as well as platelet aggregation and platelet malondialdehyde formation were performed before and after oral treatment with 28.4 mg/kg daily pentoxifylline (Trental) for 30 days. After a previous observation period, drug treatment was started at the onset of painful exacerbation, which thereby subsided within 26.4 +/- 9.6h; no further pain symptoms were observed during the treatment. All the above mentioned parameters were found to be increased before treatment when compared to normal subjects and they fell progressively during treatment: red blood cell calcium 86.0 +/- 17.9 mumol/l (before), 45.0 +/- 8.2 mumol/l (after); intraplatelet calcium 31.6 +/- 10.5 mumol/10(9) platelets (before), 18.0 +/- 5.2 mumol/10(9) platelets (after); malondialdehyde 18.6 +/- 8.9 mumol/10(9) platelets (before), 9.3 +/- 3.9 mumol/10(9) platelets (after). Also platelet aggregation index was significantly reduced. It is concluded that clinical improvement of patients was attributable to the effects of pentoxifylline on both red blood cells and platelets.

Placebo controlled double-blind study of pentoxifylline in sickle cell disease patients.

Sixty patients (37 males, 23 females, age range 7 to 34 years) suffering from sickle cell disease were treated with pentoxifylline (1200 mg/day per os, Trental 400 t.i.d.) or placebo in a double-blind randomized study of six week duration. Observation of pain frequency, intensity and duration of pain events as well as determination of various laboratory and hematologic parameters were maintained on weekly or biweekly basis, respectively, throughout the study. At the end of the trial the number of patients (14) with pain periods and the number of pain events (57) and the mean duration of pain events (4.1 days) in the drug group were significantly better than in the placebo group with 25 patients with pain, 219 pain events and 8.8 days mean pain duration. Hematocrit, red cell count, hemoglobin and platelet aggregation showed slight but significant positive changes with no corresponding alteration with placebo. The over all assessment of the therapeutic response showed 21 clearly improved patients with pentoxifylline compared to 10 such patients with placebo (p less than 0.05). Two patients on pentoxifylline and four on placebo experienced transient side effects of nausea and gastric intolerance.

Changes in plasma levels of 17 beta-estradiol after administration of an analogue of luteinizing hormone releasing hormone (LHRH-A) and pimozide in Diplectrum formosum (Teleostei: Serranidae).

Gonadotropin secretion in teleosts is known to be stimulated by gonadotropin hormone releasing hormone (GnRH) and inhibited by dopamine. This study has investigated the effects of administration of pimozide (PIM) alone or in combination with an analogue of GnRH on plasma 17 beta-estradiol (17 beta-E) levels and the gonadosomatic index. Adult Diplectrum formosum were treated with a gonadotropin-releasing hormone analogue [des-Gly10 D-Ala6 Pro9 N-ethylamide (LHRH-A); 50, 70, and 100 ng/g body wt] alone or in combination with pimozide (PIM), a dopamine antagonist (0.5, 1.0, and 5.0 micrograms/g body wt). LHRH-A alone caused a dose-dependent increase in plasma 17 beta-E levels. A single injection of PIM (0.5 or 5.0 micrograms/g) 12 hr previous to a single injection of 100 ng/g body wt of LHRH-A increased 17 beta-E concentrations compared with fish receiving PIM alone; however, 1 microgram/g PIM did not change 17 beta-E plasma levels. Simultaneous administration of PIM (0.5, 1.0, and 5.0 micrograms/g body wt) and 100 ng/g body wt of LHRH-A at an interval of 12 hr (30% of the total dose of both PIM and LHRH-A was administered in the first injection and 70% in the second injection) significantly increased plasma 17 beta-E concentrations. The magnitude of this increase was at least threefold higher than those of fish receiving a single injection of PIM, 12 hr before a single injection of LHRH-A. LHRH-A or PIM alone or combined was ineffective in causing ovulation.

Hemodynamic determinants of coronary constriction in human myocardial bridges.

To study the physiopathology of myocardial bridges, we assessed the degree of systolic coronary artery constriction (%SC) in different hemodynamic situations in six patients submitted for coronary angiograms. There was an increase of %SC (p less than 0.05) with sodium nitroprusside (NP), no modification during fast atrial stimulation (AS), and a decrease (p less than 0.05) during noradrenaline infusion (Nor). Hemodynamic studies indicate an inverse relation (p less than 0.05) between %SC and systolic and diastolic aortic pressure and left ventricular dP/dt. There was no correlation between changes in %SC and changes in Vmax or heart rate. Thus we conclude that changes in systemic arterial pressure and coronary perfusion pressure may significantly affect the degree of severity of myocardial bridges, possibly through an influence upon intraluminal coronary pressure and an intramyocardial tension relationship.

Evolution of gypsy endogenous retrovirus in the Drosophila obscura species group.

The Ty3/gypsy family of retroelements is closely related to retroviruses, and some of their members have an open reading frame resembling the retroviral gene env. Sequences homologous to the gypsy element from Drosophila melanogaster are widely distributed among Drosophila species. In this work, we report a phylogenetic study based mainly on the analysis of the 5' region of the env gene from several species of the obscura group, and also from sequences already reported of D. melanogaster, Drosophila virilis, and Drosophila hydei. Our results indicate that the gypsy elements from species of the obscura group constitute a monophyletic group which has strongly diverged from the prototypic D. melanogaster gypsy element. Phylogenetic relationships between gypsy sequences from the obscura group are consistent with those of their hosts, indicating vertical transmission. However, D. hydei and D. virilis gypsy sequences are closely related to those of the affinis subgroup, which could be indicative of horizontal transmission.

Genotype and phenotype analysis of Friedreich's ataxia compound heterozygous patients.

Friedreich's ataxia is caused by mutations in the FRDA gene that encodes frataxin, a nuclear-encoded mitochondrial protein. Most patients are homozygous for the expansion of a GAA triplet repeat within the FRDA gene, but a few patients show compound heterozygosity for a point mutation and the GAA-repeat expansion. We analyzed DNA samples from a cohort of 241 patients with autosomal recessive or isolated spinocerebellar ataxia for the GAA triplet expansion. Patients heterozygous for the GAA expansion were screened for point mutations within the FRDA coding region. Molecular analyses included the single-strand conformation polymorphism analysis, direct sequencing, and linkage analysis with FRDA locus flanking markers. Seven compound heterozygous patients were identified. In four patients, a point mutation that predicts a truncated frataxin was detected. Three of them associated classic early-onset Friedreich's ataxia with an expanded GAA allele greater than 800 repeats. The other patient associated late-onset disease at the age of 29 years with a 350-GAA repeat expansion. In two patients manifesting the classical phenotype, no changes were observed by single-strand conformation polymorphism (SSCP) analysis. Linkage analysis in a family with two children affected by an ataxic syndrome, one of them showing heterozygosity for the GAA expansion, confirmed no linkage to the FRDA locus. Most point mutations in compound heterozygous Friedreich's ataxia patients are null mutations. In the present patients, clinical phenotype seems to be related to the GAA repeat number in the expanded allele. Complete molecular definition in these patients is required for clinical diagnosis and genetic counseling.