Corrigendum: Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): a study protocol for a randomized clinical trial

[This corrects the article DOI: 10.3389/fmed.2022.1087188.].

Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): A study protocol for a randomized clinical trial

Background

Chagas disease (CD) is a neglected endemic disease with worldwide impact due to migration. Approximately 50-70% of individuals in the chronic phase of CD present the indeterminate form, characterized by parasitological and/or serological evidence of Trypanosoma cruzi infection, but without clinical signs and symptoms. Subclinical abnormalities have been reported in indeterminate form of CD, including pro-inflammatory states and alterations in cardiac function, biomarkers and autonomic modulation. Moreover, individuals with CD are usually impacted on their personal and professional life, making social insertion difficult and impacting their mental health and quality of life (QoL). Physical exercise has been acknowledged as an important strategy to prevent and control numerous chronic-degenerative diseases, but unexplored in individuals with the indeterminate form of CD. The PEDI-CHAGAS study (which stands for "Home-Based Exercise Program in the Indeterminate Form of Chagas Disease" in Portuguese) aims to evaluate the effects of a home-based exercise program on physical and mental health outcomes in individuals with indeterminate form of CD.

Methods and design

The PEDI-CHAGAS is a two-arm (exercise and control) phase 3 superiority randomized clinical trial including patients with indeterminate form of CD. The exclusion criteria are <18 years old, evidence of non-Chagasic cardiomyopathy, musculoskeletal or cognitive limitations that preclude the realization of exercise protocol, clinical contraindication for regular exercise, and regular physical exercise (≥1 × per week). Participants will be assessed at baseline, and after three and 6 months of follow-up. The primary outcome will be QoL. Secondary outcomes will include blood pressure, physical fitness components, nutritional status, fatigability, autonomic modulation, cardiac morphology and function, low back pain, depression and anxiety, stress, sleep quality, medication use and adherence, and biochemical, inflammatory and cardiac biomarkers. Participants in the intervention group will undergo a home-based exercise program whilst those in the control group will receive only general information regarding the benefits of physical activity. Both groups will receive the same general nutritional counseling consisting of general orientations about healthy diets.

Conclusion

The findings from the present study may support public health intervention strategies to improve physical and mental health parameters to be implemented more effectively in this population.

Clinical trial registration

[https://ensaiosclinicos.gov.br/rg/RBR-10yxgcr9/], identifier [U1111-1263-0153].

Impact of a Cancer Diagnosis on Quality of Life among Cancer Survivors and their Partners

Background

Cancer survivors (CS) often experience physical, psychological and socioeconomic problems, which may have a negative effect on their quality of life (QoL). Additionally, cancer may also have a significant impact on patientś families, particularly their partners (PCS), who are typically the main informal caregiver.

Objective

To estimate the association between a cancer diagnosis and a poor QoL among both members of the couples, according to sociodemographic, health-related and cancer characteristics.

Methods

This cross-sectional study was based on data from the Sixth Wave of the Survey of Health, Ageing and Retirement in Europe - SHARE, conducted in 2015, in 18 countries. All cancer survivors (n = 2,040) who lived with a partner in the same household, as well as PCS (n = 2,040) were selected, and were country-, sex-, age- and education-matched (1:1) to non-cancer individuals (NC) and their partners (PNC), respectively. QoL was assessed using the Control, Autonomy, Self-Realization and Pleasure scale (CASP-12). The association between a cancer diagnosis and a poor QoL among both members of the couple was estimated through odds ratios (ORs) and 95% confidence intervals (95%CIs).

Results

In nearly one-fifth of couples, both members reported a poor QoL (17.0%); this outcome was more frequently observed among CS than NC (OR = 1.31, 95%CI: 1.10-1.56). A tendency towards stronger odds of poor QoL among both couples’ members was observed among CS who lived in urban areas (OR = 1.91, 95%CI: 1.30-2.80), with no multimorbidity (OR = 2.07, 95%CI: 1.14-3.76), as well as among those diagnosed &lt;5 years (OR = 1.65, 95%CI: 1.21-2.24) and with cancers with a usually poor prognosis (OR = 1.82, 95%CI: 1.04-3.18), when compared with respective NC.

Conclusions

A poor QoL among both couples’ members was more frequent among couples dealing with cancer than those without cancer, which highlights the importance of closely monitoring CS and their partners, throughout the cancer survivorship course.

Key messages

• Couples dealing with cancer more frequently reported a worse quality of life among both members, when compared with couples without cancer.

• The findings of this study highlights the importance of family-focused care from an early phase after the cancer diagnosis and throughout the cancer survivorship trajectory.

Healthcare use among cancer survivors during the COVID-19 pandemic

Background

The COVID-19 pandemic and the restrictive measures applied to prevent and control this disease have led to a substantial shift in healthcare systems, with a redefinition of priorities and essential care, causing a serious impact in the oncological care. Therefore, we aimed to estimate the association of a previous cancer diagnosis on healthcare use during the COVID-19 pandemic among European and Israelis cancer survivors (CS).

Methods

This cross-sectional study was based on data from the Survey of Health, Ageing and Retirement in Europe (SHARE), including the SHARE COVID-19 Survey, which was conducted in the summer of 2020, in 27 countries. All CS (n = 6,490) were country-, sex-, age- and education-matched (1:2) to non-cancer individuals (NC). Odds ratios (OR) and 95% confidence intervals (95%CI) were computed using logistic regression.

Results

Overall, CS were more likely to refer that they forwent medical appointments due to fear of COVID-19 (OR = 1.29, 95%CI:1.19-1.41), than NC, particularly those who lived with their partner and other relatives (OR = 1.79, 95%CI:1.39-2.30). Likewise, CS reported the occurrence of postponements more often (OR = 1.54, 95%CI:1.44-1.64); this association was stronger among CS who lived with their partner and other relatives (OR = 1.96, 95%CI:1.63-2.36), who reported higher economic difficulties (OR = 1.73, 95%CI:1.50-2.00) and those with no multimorbidity (OR = 1.85, 95%CI:1.62-2.11). CS were also more likely to refer that they were unable to book an appointment (OR = 1.43, 95%CI:1.26-1.63), particularly those who reported that a person close to them died due to COVID-19 (OR = 2.72, 95%CI:1.47-5.01).

Conclusions

CS were more likely to forgo medical treatment and to report healthcare postponements and to be unable to book an appointment than NC, which highlights the importance of closely monitoring the long-term impact of the COVID-19 pandemic along the cancer care continuum.

Key messages

• During the COVID-19 pandemic, a previous cancer diagnosis was associated with a more frequent report of appointment cancellations, postponements or denials.

• The first months of the COVID-19 pandemic led to changes in healthcare provided to cancer survivors, which may have a deleterious impact in their care and prognosis.

The association of exercise test variables with long-term mortality in patients with chronic Chagas disease

Background

The identification of variables obtained in the exercise test (ET) associated with increased risk of death is clinically relevant and would provide additional information for the management of Chagas disease (CD). The objective of the present study was to evaluate the association of ET variables with mortality in patients with chronic CD.

Methods

This retrospective longitudinal observational study included 232 patients (median age 46.0 years; 50% women) with CD that were followed at the Evandro Chagas National Institute of Infectious Diseases (Rio de Janeiro, Brazil) and performed an ET between 1989 and 2000. The outcome of interest was all-cause mortality.

Results

There were 103 deaths (44.4%) during a median follow-up of 21.5 years (IQR 25–75% 8.0–27.8), resulting in 24.5 per 1,000 patients/year incidence rate. The ET variables associated with mortality after adjustments for potential confounders were increased maximal (HR 1.02; 95% CI 1.00–1.03 per mmHg) and change (HR 1.03; 95% CI 1.01–1.06 per mmHg) of diastolic blood pressure (DBP) during ET, ventricular tachycardia at rest (HR 3.95; 95% CI 1.14–13.74), during exercise (HR 2.73; 95% CI 1.44–5.20), and recovery (HR 2.60; 95% CI 1.14–5.91), and premature ventricular complexes during recovery (HR 2.06; 1.33–3.21).

Conclusion

Our findings suggest that ET provides important prognostic value for mortality risk assessment in patients with CD, with hemodynamic (increased DBP during exercise) and electrocardiographic (presence of ventricular arrhythmias) variables independently associated with an increased mortality risk in patients with CD. The identification of individuals at higher mortality risk can facilitate the development of intervention strategies (e.g., close follow-up) that may potentially have an impact on the longevity of patients with CD.

Bidirectional flow of action potentials in axons drives activity dynamics in neuronal cultures

Objective. Recent technological advances are revealing the complex physiology of the axon and challenging long-standing assumptions. Namely, while most action potential (AP) initiation occurs at the axon initial segment in central nervous system neurons, initiation in distal parts of the axon has been reported to occur in both physiological and pathological conditions. The functional role of these ectopic APs, if exists, is still not clear, nor its impact on network activity dynamics.Approach. Using an electrophysiology platform specifically designed for assessing axonal conduction we show here for the first time regular and effective bidirectional axonal conduction in hippocampal and dorsal root ganglia cultures. We investigate and characterize this bidirectional propagation both in physiological conditions and after distal axotomy.Main results.A significant fraction of APs are not coming from the canonical synapse-dendrite-soma signal flow, but instead from signals originating at the distal axon. Importantly, antidromic APs may carry information and can have a functional impact on the neuron, as they consistently depolarize the soma. Thus, plasticity or gene transduction mechanisms triggered by soma depolarization can also be affected by these antidromic APs. Conduction velocity is asymmetrical, with antidromic conduction being slower than orthodromic.Significance.Altogether these findings have important implications for the study of neuronal functionin vitro, reshaping our understanding on how information flows in neuronal cultures.

Probing stress relaxation behavior in glassy methacrylate networks containing thio-carbamate additives

The incorporation of thiourethane prepolymer (TU) into either the organic phase or as a surface treatment for filler particles in composites reduces polymerization stress and improves fracture toughness. The aim of this study was to gain insight into the influence of the inclusion of thiourethanes on the resulting network of methacrylate-based materials polymerized via free-radical mechanisms. Dynamic mechanical analysis was used to elucidate network parameters and potential stress relaxation behavior of these networks. TU oligomers were synthesized using a combination of trimethylol-tris-3-mercaptopropionate and dicyclohexylmethane 4,4'-diisocyanate and added into composite formulations at 20 wt% replacing part of the organic matrix and/or as TU-silanes used to functionalize filler particles (TU-matrix, TU-Sil or TU-matrix/sil). Materials not containing any form of TU were used as the control (in those cases, 3-(trimethoxysilyl)propyl methacrylate was used as the silane agent). Filler was added at 50 wt%. Degree of conversion was evaluated by near-IR spectroscopy, mechanical properties by 3-point bending and rotational rheometry. Dynamic mechanical analysis was used to obtain network parameters (glass transition temperature (Tg), storage modulus, cross-link density, and breadth of tan delta a proxy for network homogeneity - temperature sweep experiments) and to evaluate the potential for network relaxation (stress relaxation). TU-containing formulations showed 10% higher DC than the control. The time to reach storage/loss modulus crossover in the rheometer experiments was significantly longer for TU-matrix and TU-matrix/sil in comparison with the control (21.6, 27.9, and 5.1 s, respectively). TU-matrix and TU-matrix/sil presented significant lower Tg than the control (151.5, 153.8, and 161.3 °C, respectively). There were no statistical differences among the groups in terms of shear modulus, cross-link density, breadth of tan delta, flexural strength/modulus, and toughness. For at least one group (TU-matrix/sil), the relaxation time was four times faster than for the control at 105 °C. The addition of TU additives into dental polymers resulted in a stark reduction in the stress relaxation time. This behavior, in tandem with the network characterization and mechanical properties seems to indicate the TU networks undergo a variety of reversible associative and dissociative chemical reactions which facilitate enhanced stress relief.

Benznidazole decreases the risk of chronic Chagas disease progression and cardiovascular events: A long-term follow up study

BACKGROUND

Chagas disease (CD) remains an important endemic disease in Latin America. However, CD became globalized in recent decades. The majority of the chronically infected individuals did not receive etiologic treatment for several reasons, among them the most conspicuous is the lack of access to diagnosis. The impact of trypanocidal treatment on CD chronic phase, without cardiac involvement (indeterminate form ICF), is yet to be determined. We aimed to evaluate the effect of trypanocidal treatment with benznidazole (BZN) on the rate of progression to Chagas heart disease in patients with ICF.

METHODS

This is a retrospective cohort observational study including patients with ICF treated with BZN and compared to a group of non-treated patients matched for age, sex, region of origin, and the year of cohort entry. We reviewed the medical charts of all patients followed from May 1987 to June 2020 at the outpatient center of the Evandro Chagas National Institute of Infectious Diseases (INI) of the Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil. Patients' follow-up included at least one annual medical visit and one annual electrocardiogram (ECG). Echocardiographic exams were performed at baseline and during the follow-up. Disease progression from ICF to cardiac form was defined by changes in baseline ECG. Cumulative incidence and the incidence rate were described in the incidence analysis. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for the association between BZN and CD progression, cardiovascular events or death.

FINDINGS

One hundred and fourteen treated patients met the study inclusion criteria. A comparison group of 114 non-treated patients matched for age, sex, region of origin, and the year of cohort entry was also included, totalizing 228 patients. Most patients included in the study were male (70.2%), and their mean age was 31.3 (+7.4) years. Over a median follow-up of 15.1 years (ranging from 1.0 to 32.4), the cumulative CD progression incidence in treated patients was 7.9% vs. 21.1% in the non-treated group (p = 0.04) and the CD progression rate was 0.49 per 1.000 patients/year in treated patients vs. 1.10 per 1.000 patients/year for non-treated patients (p = 0.02). BZN treatment was associated with a decreased risk of CD progression in both unadjusted (HR 0.46; 95%CI 0.21 to 0.98) and adjusted (HR 0.43; 95%CI 0.19 to 0.96) models and with a decreased risk of occurrence of the composite of cardiovascular events only in the adjusted (HR 0.15; 95%CI 0.03 to 0.80) model. No association was observed between BZN treatment and mortality.

INTERPRETATION

In a long-term follow-up, BZN treatment was associated with a decreased incidence of CD progression from ICF to the cardiac form and also with a decreased risk of cardiovascular events. Therefore, our results indicate that BZN treatment for CD patients with ICF should be implemented into clinical practice.

Effect of Hydrofluoric Acid Concentration and Etching Time on Bond Strength to Lithium Disilicate Glass Ceramic

The aim of this study was to evaluate the influence of different concentrations of hydrofluoric acid (HF) associated with varied etching times on the microshear bond strength (μSBS) of a resin cement to a lithium disilicate glass ceramic. Two hundred seventy-five ceramic blocks (IPS e.max Press [EMX], Ivoclar Vivadent), measuring 8 mm × 3 mm thickness, were randomly distributed into five groups according to the HF concentrations (n=50): 1%, 2.5%, 5%, 7.5%, and 10%. Further random distribution into subgroups was performed according to the following etching times (n=10): 20, 40, 60, 120, and 20 + 20 seconds. After etching, all blocks were treated with a silane coupling agent followed by a thin layer of an unfilled resin. Three resin cement cylinders (∅=1 mm) were made on each EMX surface, which was then stored in deionized water at 37°C for 24 hours before testing. The μSBS was in a universal testing machine at a crosshead speed of 1 mm/min until failure. Data were submitted to two-way analysis of variance, and multiple comparisons were performed using the Tukey post hoc test (α=0.05). One representative EMX sample was etched according to the description of each subgroup and evaluated using scanning electron microscopy for surface characterization. The HF concentrations of 5%, 7.5%, and 10% provided significantly higher μSBS values than 1% and 2.5% (p<0.05), regardless of the etching times. For 1% and 2.5% HF, the etching times from 40 to 120 seconds increased the μSBS values compared with 20 seconds (p<0.05), but etching periods did not differ within the 5%, 7.5%, and 10% HF groups (p>0.05). The effect of re-etching was more evident for 1% and 2.5% HF (p<0.05). Different HF concentrations/etching times directly influenced the bond strength and surface morphology of EMX.

Sex Hormones Protect Against Amyloid-β Induced Oxidative Stress in the Choroid Plexus Cell Line Z310

The choroid plexus (CP) epithelium is a unique structure in the brain that forms an interface between the peripheral blood on the basal side and the cerebrospinal fluid (CSF) on the apical side. It is a relevant source of many polypeptides secreted to the CSF with neuroprotective functions and also participates in the elimination and detoxification of brain metabolites, such as β-amyloid (Aβ) removal from the CSF through transporter-mediated influx. The CP is also a target tissue for sex hormones (SHs) that have recognised neuroprotective effects against a variety of insults, including Aβ toxicity and oxidative stress in the central nervous system. The present study aimed to understand how SHs modulate Aβ-induced oxidative stress in a CP cell line (Z310 cell line) by analysing the effects of Aβ1-42 on oxidative stress, mitochondrial function and apoptosis, as well as by assessing how 17β-oestradiol (E2 ) and 5α-dihydrotestosterone (DHT) modulated these effects and the cellular uptake of Aβ1-42 by CP cells. Our findings show that E2 and DHT treatment reduce Aβ1-42 -induced oxidative stress and the internalisation of Aβ1-42 by CP epithelial cells, highlighting the importance of considering the background of SHs and therefore sex-related differences in Aβ metabolism and clearance by CP cells.

The Effect of Hydrofluoric Acid Concentration on the Bond Strength and Morphology of the Surface and Interface of Glass Ceramics to a Resin Cement

The purpose of this study was to evaluate the influence of various concentrations of hydrofluoric acid (HF) on the surface/interface morphology and μ-shear bond strength (μSBS) between IPS Empress Esthetic (EST) (Ivoclar Vivadent) and IPS e.max Press (EMX) (Ivoclar Vivadent) ceramics and resin cement. Ceramic blocks were divided into 12 groups for each kind of ceramic. Six different HF concentrations were evaluated: 1%, 2.5%, 5%, 7.5%, 10%, and 15%. All groups were silanated after etching, and half of the specimens within each group received a thin layer of unfilled resin (UR). Three resin cement cylinders were prepared on each ceramic block for μSBS testing. The specimens were stored in distilled water at 37°C for 24 hours. The μSBS test was carried out in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. The data were submitted to three-way analysis of variance and multiple comparisons were performed using the Tukey post hoc test (p<0.05). The etched surfaces and bonded interfaces were evaluated using scanning electron microscopy. μSBS means (MPa) for 1%, 2.5%, 5%, 7.5%, 10%, and 15% HF concentrations were, respectively, 25.2, 27.2, 30.1, 31.4, 33.3, and 31.8. μSBS means with or without UR application measured 32.24 and 27.4, respectively; EST and EMX measured 29.8 and 29.9, respectively. For the HF concentrations, 10% and 15% showed higher μSBS means than did 1% and 2.5% (p<0.05); 7.5% was higher than 1% (p<0.05); and no statistical differences were found among the other concentrations (p>0.05). When evaluating UR, μSBS mean was significantly higher and better infiltration was observed on the etched surfaces. No statistical difference was found between the ceramics. The HF concentration and UR influenced the bond strength and surface/interface morphology.

Effects of Surface Treatments, Thermocycling, and Cyclic Loading on the Bond Strength of a Resin Cement Bonded to a Lithium Disilicate Glass Ceramic

Objectives

The aim of this present study was to investigate the effect of two surface treatments, fatigue and thermocycling, on the microtensile bond strength of a newly introduced lithium disilicate glass ceramic (IPS e.max Press, Ivoclar Vivadent) and a dual-cured resin cement.

Methods

A total of 18 ceramic blocks (10 mm long × 7 mm wide × 3.0 mm thick) were fabricated and divided into six groups (n=3): groups 1, 2, and 3—air particle abraded for five seconds with 50-μm aluminum oxide particles; groups 4, 5, and 6—acid etched with 10% hydrofluoric acid for 20 seconds. A silane coupling agent was applied onto all specimens and allowed to dry for five seconds, and the ceramic blocks were bonded to a block of composite Tetric N-Ceram (Ivoclar Vivadent) with RelyX ARC (3M ESPE) resin cement and placed under a 500-g static load for two minutes. The cement excess was removed with a disposable microbrush, and four periods of light activation for 40 seconds each were performed at right angles using an LED curing unit (UltraLume LED 5, Ultradent) with a final 40 second light exposure from the top surface. All of the specimens were stored in distilled water at 37°C for 24 hours. Groups 2 and 5 were submitted to 3,000 thermal cycles between 5°C and 55°C, and groups 3 and 6 were submitted to a fatigue test of 100,000 cycles at 2 Hz. Specimens were sectioned perpendicular to the bonding area to obtain beams with a cross-sectional area of 1 mm2 (30 beams per group) and submitted to a microtensile bond strength test in a testing machine (EZ Test) at a crosshead speed of 0.5 mm/min. Data were submitted to analysis of variance and Tukey post hoc test (p≤0.05).

Results

The microtensile bond strength values (MPa) were 26.9 ± 6.9, 22.2 ± 7.8, and 21.2 ± 9.1 for groups 1–3 and 35.0 ± 9.6, 24.3 ± 8.9, and 23.9 ± 6.3 for groups 4–6. For the control group, fatigue testing and thermocycling produced a predominance of adhesive failures. Fatigue and thermocycling significantly decreased the microtensile bond strength for both ceramic surface treatments when compared with the control groups. Etching with 10% hydrofluoric acid significantly increased the microtensile bond strength for the control group.

Influence of the volume of composite and photoactivation method on push-out bond strength and Knoop hardness of a resin composite

AIM

The aim of this paper was to evaluate the influence of modulated photoactivation methods and volume of composite on Knoop hardness (KHN) and push-out bond strength (PBS) of Filtek Z350 to root dentin.

METHODS

Three volumes (small, medium and large) of composite were bulk inserted in cavities prepared in 90 premolars. The specimens were photoactivated with continuous light, pulse-delay, or soft-start methods and submitted to PBS and KHN tests. The failure pattern was evaluated in stereomicroscope after the bond strength test. The data were submitted to two-way ANOVA and Tukey's test (P<0.05).

RESULTS

Modulated photoactivation methods showed a higher PBS than continuous method (P<0.05). Medium volume of composite showed higher PBS than small and large volumes when photoactivated with continuous method (P<0.05). Pulse-delay significantly increased KHN for medium and large volumes in comparison to continuous method (P<0.05). Medium volume of composite showed KHN significantly higher than small and large volumes (P<0.05).

CONCLUSION

The volume of composite influenced the PBS and KHN of resin composites. Pulse-delay showed the highest bond strength to dentin, as well KHN similar to the conventional method. The analysis of the failure pattern showed predominance of adhesive failure.

Optical mapping of cryoinjured rat myocardium grafted with mesenchymal stem cells

Mesenchymal stem cells (MSCs) have been shown to improve cardiac electrophysiology when administered in the setting of acute myocardial infarction. However, the electrophysiological phenotype of MSCs in situ is not clear. We hypothesize that MSCs delivered intramyocardially to cryoinjured myocardium can engraft, but will not actively generate, action potentials. Cryoinjury-induced scar was created on the left ventricular epicardial surface of adult rat hearts. Within 30 min, hearts were injected with saline (sham, n = 11) or bone marrow-derived MSCs (2 × 10(6)) labeled with 1,1'-dioctadecyl-3,3,3,3'-tetramethylindocarbocyanine percholate (DiI; n = 16). At 3 wk, optical mapping and cell isolation were used to measure optical action potentials and calcium transients, respectively. Histological analysis confirmed subepicardial scar thickness and the presence of DiI-positive cells that express connexin-43. Optical action potential amplitude within the scar at MSC-positive sites (53.8 ± 14.3%) was larger compared with sites devoid of MSCs (35.3 ± 14.2%, P < 0.05) and sites within the scar of shams (33.5 ± 6.9%, P < 0.05). Evidence of simultaneous action potential upstroke, the loss of action potential activity following ablation of adjacent viable myocardium, and no rapid calcium transient response in isolated DiI+ cells suggest that the electrophysiological influence of engrafted MSCs is electrotonic. MSCs can engraft when directly injected into a cryoinjury and are associated with evidence of action potential activity. However, our results suggest that this activity is not due to generation of action potentials, but rather passive influence coupled from neighboring viable myocardium.

The negative inotropic action of canrenone is mediated by L-type calcium current blockade and reduced intracellular calcium transients

BACKGROUND AND PURPOSE

Adding spironolactone to standard therapy in heart failure reduces morbidity and mortality, but the underlying mechanisms are not fully understood. We analysed the effect of canrenone, the major active metabolite of spironolactone, on myocardial contractility and intracellular calcium homeostasis.

EXPERIMENTAL APPROACH

Left ventricular papillary muscles and cardiomyocytes were isolated from male Wistar rats. Contractility of papillary muscles was assessed with force transducers, Ca(2+) transients by fluorescence and Ca(2+) fluxes by electrophysiological techniques.

KEY RESULTS

Canrenone (300-600 micromol L(-1)) reduced developed tension, maximum rate of tension increase and maximum rate of tension decay of papillary muscles. In cardiomyocytes, canrenone (50 micromol L(-1)) reduced cell shortening and L-type Ca(2+) channel current, whereas steady-state activation and inactivation, and reactivation curves were unchanged. Canrenone also decreased the Ca(2+) content of the sarcoplasmic reticulum, intracellular Ca(2+) transient amplitude and intracellular diastolic Ca(2+) concentration. However, the time course of [Ca(2+)](i) decline during transients evoked by caffeine was not affected by canrenone.

CONCLUSION AND IMPLICATIONS

Canrenone reduced L-type Ca(2+) channel current, amplitude of intracellular Ca(2+) transients and Ca(2+) content of sarcoplasmic reticulum in cardiomyocytes. These changes are likely to underlie the negative inotropic effect of canrenone.

The role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance

The aim of this study was to determine the role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance. The adherence of S. epidermidis 1457 and the mutant defective in PIA production (1457-M10) to urinary epithelium and endothelium was estimated by colony counting. Minimum bactericidal concentration and mean reduction of cellular activity (XTT) following antibiotic exposure was determined for planktonic and adhered bacteria. S. epidermidis 1457 adhered to a greater extent to both cells than the mutant strain. The adhered strains had a significantly higher antimicrobial tolerance than their planktonic counterparts. The mutant strain was, in general, the most susceptible to the antibiotics assayed. In conclusion, PIA may influence S. epidermidis adherence to host tissues and their antimicrobial susceptibility. Initial adhesion may be the main step for the acquisition of resistance in S. epidermidis.

Isolation of Mycobacterium gordonae from poultry slaughterhouse water in São Paulo State, Brazil

Water samples (24 untreated water, 12 treated water and 24 served water) used in different stages of the slaughter process were examined to identify a possible source of pathogenic mycobacteria. The isolates were identified based on microscopy, morphological and biochemical features, mycolic acid analysis and molecular method--PCR-restriction-enzyme analysis. Eighteen mycobacterial strains were isolated from 60 water samples: 11 from untreated water, 5 from treated water and 2 from served water. All mycobacteria isolated were identified as Mycobacterium gordonae and showed the following PRA genotypes: III (27.8%), IV (38.9%) and V (33.3%).

Trichophyton raubitschekii: a new agent of dermatophytosis in Brazil?

A microbiological and ultrastructural study of Trichophyton raubitschekii recovered from a patient with tinea faciei is presented. This is the second case of isolation of this fungus in Sao Paulo and the sixth case in Brazil. Upon culture, the morphological pattern and the physiological tests performed confirmed the identification of T. raubitschekii. The ultrastructural study of T. raubitschekii showed the presence of a membrane-like structure located in the outer portion of the hyphal walls. This structure was bi-stratified and very like the one observed in T. rubrum. Is T. raubitschekii a new fungus emerging in Brazil or is it a T. rubrum variant?

Chronic paroxysmal hemicrania-tic syndrome

The association of chronic paroxysmal hemicrania and ticlike pain-chronic paroxysmal hemicrania-tic (CPH-tic)-is a recently described syndrome. The authors found only two previously reported cases. They report three new cases of this rare syndrome with both chronic paroxysmal hemicrania and ticlike pain concurrently and ipsilaterally. The trigeminal-autonomic cephalalgias (TAC) are considered as differential diagnoses. CPH-tic syndrome could be a different clinical entity.

[The use of a rate-responsive pacemaker after heart transplantation]

PURPOSE

The indications and the results of pacemaker implant following orthotopic cardiac transplantation.

METHODS

Four patients implanted a cardiac pacemaker (PM) in the early post-operative period (PO) of orthotopic cardiac transplantation (from 10th to 16th PO day). The patients were 33 to 55 year-old and the indications to PM were supraventricular arrhythmia (atrial fibrillation or flutter) associated with atrioventricular block in three, and complete atrioventricular block in one patient. Previous to PM implant, patients were submitted to endomyocardial biopsy, which was normal in two patients, evidenced mild rejection in one and moderate rejection in the remaining. A ventricular rate responsive pacemaker was implanted in all patients, with sensors responsive to muscular activity in one patient, and to minute ventilation in three.

RESULTS

One patient died in the 20th PO due to acute allograft rejection not controlled by immunosuppressive drugs. Three other patients had satisfactory evolution and the pacemakers were programmed during exercise testing, previous to hospital discharge. Recent evaluation revealed that these patients are in good clinical condition at the 6th, 14th and 24th PO months. Adequate pacemaker function was insured by exercise testing and ambulatory electrocardiographic recording.

CONCLUSION

A ventricular rate responsive pacemaker represented a satisfactory mode of pacing, in patients with severe bradycardia, following heart transplantation.

Rhinofacial zygomycosis caused by Conidiobolus coronatus. A case report

A case of rhinofacial zygomycosis with of years duration, caused by Conidiobolus coronatus is described. The patient, a 72-years-old woman, presented with a bilateral distortion of the subcutaneous tissue and disfigurement of the face. Treatment with ketoconazole and potassium iodide did not prevent several relapses. At present she is still under treatment with fluconazole with clinical healing. Histopathological and mycological examination confirmed the dermatological diagnosis. An increasing number of cases of zygomycosis caused by fungi of the order Entomophthorales have also been reported in the Northern and Northeastern States of Brazil.

Subcutaneous phaeohyphomycosis caused by Bipolaris hawaiiensis. A case report

A case of phaeohyphomycosis caused by Bipolaris hawaiiensis is reported. The patient, an immunocompetent host, presented a verrucous lesion on the first finger of the left foot. Dematiaceous septate hyphae and yeast-like elements were seen in direct and histological examination. The isolated strain was identified on the basis of micro and macromorphological aspects. Treated with electrocoagulation, the lesions healed and presented no relapse after two years follow-up.

Subcutaneous mucormycosis caused by Mucor hiemalis Wehmer f. luteus (Linnemann) Schipper 1973

The authors report a case of subcutaneous mucormycosis in a diabetic patient with verrucous lesions in the fourth finger of the right hand. Initially diagnosed as a fixed cutaneous sporotrichosis case, success was obtained with the use of potassium iodide with healing of the lesion in a period of nearly 5 months. At present the patient remains under clinical observation with no treatment or relapse.

[Sternal cleft. Surgical treatment in the newborn]

The lack of total sternal fusion without other anomalies of the chest wall is extremely rare. We present the case of one 24 h. old female, clinically asymptomatic with complete sternal cleft without other symptoms. She was operated on within the first week of life, a sternal primary suture with costal condrotomy and alternate costal suture were performed. Good thoracic stability was obtained. We agree with other authors about the need for surgical correction during the neonatal period.