P936Atrial remodeling in rat hearts after exposure to high-intensity infrasound

Background

Noise is an important environmental risk factor. Industrial environments are rich in high-intensity infrasound (hi-IFS), which we have found to induce myocardial and coronary perivascular fibrosis in rats. Recently, a significant association between noise exposure and the incidence of atrial fibrillation (AF) was found in large cohort studies but the pathophysiology is unclear. Atrial fibrosis remains the cornerstone of atrial pathology in AF. Purpose: We hypothesized that rats exposed to hi-IFS develop atrial remodeling involving fibrosis and connexin 43, which we sought to evaluate. Material and Methods: Seventy-two Wistar rats, half exposed to hi-IFS (120dB, <20Hz) during a maximum period of 12 weeks and half age-matched controls, were studied. Atrial fibrosis was analyzed by Chromotrope-aniline blue staining. The immunohistochemical evaluation of Cx43 was performed using the polyclonal antibody connexin-43m diluted 1:1000 at 4ºC overnight. Digitized images were obtained with an optical microscope using 400× magnifications. The measurements were performed using image J software. A two-way ANOVA model was used to compare the groups. Results: The mean values of the ratio "atrial fibrosis / cardiomyocytes" increased to a maximum of 0,1095 ± 0,04 and 0,5408 ± 0,01, and of the ratio "CX43 / cardiomyocytes" decreased to 0,0834 ± 0,03 and 0,0966 ± 0,03, respectively in IFS-exposed rats and controls. IFS-exposed rats exhibited a significantly higher ratio of fibrosis (p < 0,001) and lower ratio of Cx43 (p = 0,009). Conclusion: High-intensity infrasound exposure triggers atrial remodeling in rat hearts. Whether this finding correlates to arrhythmogenic substrate in noise induced-AF is not known and reinforces the need for further experimental studies.

Table 1 Time of exposure (weeks) Group IFS (n = 36) Group CTL (n = 36) P value Ratio of atrial fibrosis / cardiomyocytesMean ± SD 1 0,0896 ± 0,04 0,0460 ± 0,03 0,007 6 0,0936 ± 0,03 0,0491 ± 0,01 0,001 12 0,1095 ± 0,04 0,0541 ± 0,01 0,001 Ratio of atrial CX43 / cardiomyocytesMean ± SD 1 0,1100 ± 0,03 0,1371 ± 0,03 0,047 6 0,0829 ± 0,04 0,1036 ± 0,03 0,170 12 0,0834 ± 0,03 0,0966 ± 0,03 0,259 Mean ± SD of the two measured outcomes in the two groups. IFS – Infrasound; CTL – Control; SD – standard deviation; Cx43 – Connexin 43

Abstract Figure. Atrial fibrosis and Cx43 /cardiomyocytes

P1332 Breaking the dichotomy of myocardial infarction and stress cardiomyopathy

INTRODUCTION

An 83-year-old woman with a past medical history of hypertension, dyslipidaemia and recent diagnosis of disseminated breast cancer was admitted at Emergency department for acute heart failure. She complained about short chest pain episodes on previous days, the ECG showed new T negative waves on precordial leads and high sensitive troponin serum levels were modestly increased (TropT 1200ng/l). Echocardiographic assessment documented moderate left ventricular dysfunction (LVEF 40%) with apical and midventricular dyskinesia associated with hypercontractility off basal segments.

The following day the patient underwent a coronary angiography that showed an occlusion in the distal segment of a large obtuse marginal branch (Panel A) with no other significant stenosis in the remaining vessels. Ventriculography showed a typical apical ballooning pattern (Panel B). Despite the occluded coronary artery was reaching the apex, the myocardial wall motion abnormalities extended beyond the ischemic territory. Therefore, a cardiac magnetic resonance (CMR) was performed a few days later in order to clarify the diagnosis.

CMR confirmed the mid LVEF dysfunction with apical dyskinesia and the T2 weighted spin echo images showed myocardial oedema in all the apical segments (Panel C). Remarkably, a subedocardial late gadolinium enhancement (LGE) restricted to the apical segment of the inferolateral wall was detected, being consistent with the ischaemic territory of the occluded obtuse marginal branch (Panel D). These findings supported the concomitant diagnosis of an apical stress cardiomyopathy and an acute inferolateral myocardial infarction. The patient was successfully discharged one week later with a normal LVEF and no signs of congestion.

DISCUSSION

Apical ballooning in the scenario of an acute coronary syndrome may be secondary to both an acute coronary artery occlusion or to stress cardiomyopathy. Cardiac MR has a key role to resolve the differential diagnosis of these two aetiologies, since ischemia typically produces a subendocardial late gadolinium enhancement pattern and stress cardiomyopathy shows an apical oedema without coronary stenosis or extending beyond a localized ischemic territory. Our case is astonishing because in the clinical practice these two diagnoses frequently excludes each other, but as demonstrated in our case, the differential diagnosis between myocardial infarction and stress cardiomyopathy is not a proper dichotomy.

Abstract P1332 Figure

Antibiotic therapy in acute pancreatitis: From global overuse to evidence based recommendations

BACKGROUND

Unwarranted administration of antibiotics in acute pancreatitis presents a global challenge. The clinical reasoning behind the misuse is poorly understood. Our aim was to investigate current clinical practices and develop recommendations that guide clinicians in prescribing antibiotic treatment in acute pancreatitis.

METHODS

Four methods were used. 1) Systematic data collection was performed to summarize current evidence; 2) a retrospective questionnaire was developed to understand the current global clinical practice; 3) five years of prospectively collected data were analysed to identify the clinical parameters used by medical teams in the decision making process, and finally; 4) the UpToDate Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was applied to provide evidence based recommendations for healthcare professionals.

RESULTS

The systematic literature search revealed no consensus on the start of AB therapy in patients with no bacterial culture test. Retrospective data collection on 9728 patients from 22 countries indicated a wide range (31-82%) of antibiotic use frequency in AP. Analysis of 56 variables from 962 patients showed that clinicians initiate antibiotic therapy based on increased WBC and/or elevated CRP, lipase and amylase levels. The above mentioned four laboratory parameters showed no association with infection in the early phase of acute pancreatitis. Instead, procalcitonin levels proved to be a better biomarker of early infection. Patients with suspected infection because of fever had no benefit from antibiotic therapy.

CONCLUSIONS

The authors formulated four consensus statements to urge reduction of unjustified antibiotic treatment in acute pancreatitis and to use procalcitonin rather than WBC or CRP as biomarkers to guide decision-making.

Portuguese consensus document for the management of alpha-1-antitrypsin deficiency

Alpha-1-antitrypsin deficiency (AATD) is a genetic autosomal codominant disorder caused by mutations in SERPINA1 gene. It is one of the most prevalent genetic disorders, although it remains underdiagnosed. Whereas at international level there are several areas of consensus on this disorder, in Portugal, inter-hospital heterogeneity in clinical practice and resources available have been adding difficulties in reaching a diagnosis and in making therapeutic decisions in this group of patients. This raised a need to draft a document expressing a national consensus for AATD. To this end, a group of experts in this field was created within the Portuguese Pulmonology Society - Study group on AATD, in order to elaborate the current manuscript. The authors reviewed the existing literature and provide here general guidance and extensive recommendations for the diagnosis and management of AATD that can be adopted by Portuguese clinicians from different areas of Medicine. This article is part of a supplement entitled "Portuguese consensus document for the management of alpha-1-antitrypsin deficiency" which is sponsored by Sociedade Portuguesa de Pneumologia.

Reference equations for the 6-minute walk distance in healthy Portuguese subjects 18-70 years old

INTRODUCTION

Six-minute walk test (6MWT) is used for evaluating functional exercise capacity. To the best of our knowledge, there are no reference equations to predict six-minute walk distance (6MWD) for the Portuguese population. The aims of the present study were to measure anthropometric data and 6MWD in a sample of healthy Portuguese population, to establish reference equations to predict 6MWD and to compare our equations with those obtained by previously published studies.

METHODS

We conducted an observational prospective study. We consecutively recruited 158 healthy 18-70 years old subjects from Porto district, who performed two 6MWTs using a standardized protocol. The best 6MWD was used for further analysis.

RESULTS

The mean 6MWD was 627.8m (SD=73.3m). The variables that were significantly associated with the 6MWD were age, sex, BMI and ΔHR (Heart Rate_{at the end of the test}-HR_{at rest)}. We found three explanatory models for 6MWD, the best with an explanatory power of 38%: 6MWD=721.7-1.6×Age-4.0×BMI+0.9×ΔHR+58.4×Sex. We verified that 6MWD decreased 1.6m per year of age, and 4.0m per unit of BMI and increased 0.892m per beat per minute. Moreover, on average, males walk 58.4m more than females (p<0.001). Applying equations from other studies to our population resulted in an overestimation or underestimation of the 6MWD.

CONCLUSION

The present study was the first to describe the 6MWD in healthy Portuguese people aged 18-70 years old and to propose predictive equations. These can contribute to improving the evaluation of Caucasian Mediterranean patients with diseases that affect their functional capacity.

Severe asthma in obese patients: Improvement of lung function after treatment with omalizumab

INTRODUCTION

Asthma and obesity have a considerable impact on public health and their prevalence is increasing. Obesity is a known risk factor for asthma and can make it more difficult to control. Omalizumab is recommended in patients with severe allergic persistent asthma. The aim of this study was to assess the impact of omalizumab treatment in obese asthmatic patients with poorly controlled severe persistent asthma.

METHODOLOGY

A non-interventional, prospective study was conducted, in an outpatient asthma clinic. All patients with severe asthma who started treatment with omalizumab were included and followed over 12 months. The study population was divided into two groups (obese and non-obese) for statistical analysis (descriptive and comparative analysis).

RESULTS

Thirty-two patients (19 obese) were followed. After 12 months of omalizumab treatment, there was a statistically significant improvement in body mass index, number of exacerbations in the previous year, rescue medication, disease control and lung function, in the whole population. At the end of the study obese patients had a significantly better lung function (FEV₁) than non-obese.

DISCUSSION

As described in the literature, there was a significant reduction in the number of exacerbations in the previous year, rescue medication and better disease control, in the whole population. In relation to lung function, about which published data are inconsistent, treatment with omalizumab significantly improved it in obese patients.

CONCLUSION

Our study showed that omalizumab significantly improved asthma control, reduced rescue medication and asthma exacerbations in all the population; and for the first time showed that obese patients achieved significantly improved lung function.

Mycobacterium avium infection in Portugal

BACKGROUND

Although the incidence rates of non-tuberculous mycobacteria (NTM) have been increasing in many countries, the basic epidemiology of NTM remains to be fully understood.

OBJECTIVE

To assess the incidence, clinical relevance and geographical distribution of NTM disease in Portugal and to identify demographic and clinical characteristics associated with Mycobacterium avium complex (MAC) disease.

METHODS

Information stored in an electronic database of all NTM cases reported over an 11-year period was retrospectively reviewed. Significant demographic and clinical characteristics of MAC disease (vs. having any other NTM disease) were determined using multiple logistic regression models.

RESULTS

We identified 632 patients, mostly male, native Portuguese, with pulmonary disease, predominantly from Lisbon and Porto. The annual incidence of NTM disease was 0.54 per 100 000 population. The annual number of NTM cases increased throughout the study period. MAC was most frequently isolated. MAC disease was positively (and significantly) associated with being female, age >45 years and human immunodeficiency virus infection.

CONCLUSIONS

The increasing incidence of NTM over the study period emphasises the importance of NTM as a public health issue. This study provides important information for health care professionals and a basis for further study of NTM in Portugal.

Does any association exist between Chronic Obstructive Pulmonary Disease and Erectile Dysfunction? The DECODED study

INTRODUCTION

Erectile dysfunction (ED) is the inability to achieve or maintain an erection for satisfactory sexual activity. Recent studies have shown an association between ED and chronic obstructive pulmonary disease (COPD). However, this issue is often ignored. We aimed to evaluate the ED prevalence in COPD patients and its risk factors and to study the impact of dyspnea in sexual activity.

METHODS

Cross-sectional study that included sexually active male patients with COPD. The International Index of Erectile Function (IIEF-5) questionnaire evaluated ED and the Respiratory Experiences with Sexuality Profile (RESP) was used to evaluate the impact of dyspnea on sexual activity. Risk factors for mild-moderate or moderate ED were determined using logistic regression.

RESULTS

84 patients were consecutively assessed for eligibility, 67 were included (median age: 65 years, 13% never-smokers). Twenty two percent had COPD 2011-GOLD A; 22% GOLD B, 14% GOLD C and 42% GOLD D. Fifty-eight patients (87%) had some degree of ED: 26 (45%) mild, 20 (34%) mild-moderate and 12 (21%) moderate ED. ED occurred in all GOLD stages of COPD, mainly in GOLD B and D stages. Higher CAT score was independently associated to mild-moderate/moderate ED. Most patients (85%) reported dyspnea during their sexual activity but 72% had never talked about it with their physician.

CONCLUSIONS

ED is highly prevalent among COPD patients and it is more severe in patients with higher CAT scores. Dyspnea affects their sexual activity but this is not a topic often discussed between patients and doctors, something which needs to be improved.

Effects of positive airway pressure therapy on cardiovascular and metabolic markers in males with obstructive sleep apnea

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular/metabolic complications. Some analytical parameters (homocysteine, glycemic and lipidic profiles) are recognized markers of these consequences. Limited data is available on the association of these markers and OSAS's severity/response to positive airway pressure therapy (PAP).

MATERIAL AND METHODS

In this prospective study we analyzed polysomnographic and analytical data of male patients admitted to sleep laboratory. The aim was to evaluate metabolic/cardiovascular markers in snorers and OSAS patients, to relate with sleep parameters and PAP response. One-hundred and three patients were included, and 73 (71%) were OSAS patients. OSAS patients were similar to snorers except for higher body mass index (BMI) and dyslipidemia. Severe OSAS patients showed higher glycemia, HbA1c, insulin, and insulin resistance, and lower HDL cholesterol in comparison to mild-moderate (p<0.05, p<0.05, p<0.001, p<0.001, p<0.05, respectively). Glycemic profile and triglycerides were slightly correlated with OSAS severity. 46 OSAS patients were submitted to 6 months of PAP, with a statistical decrease in mean values of homocysteine, glycemia, total and LDL cholesterol (p<0.05, p<0.05, p<0.05, respectively), and in glycemia and LDL cholesterol in severe group only (p<0.05, p<0.05, respectively).

RESULTS

This study demonstrated an association between glucose metabolism parameters and triglycerides with OSAS severity underlying the complexity of the process leading to cardiovascular/metabolic complications in this disorder. Moreover, homocysteine, glycemic and lipidic profiles changed significantly after 6 months of PAP therapy in OSAS, supporting its cardiovascular and metabolic protective effect.

CONCLUSION

Our study has reinforced the importance of analytical cardiovascular/metabolic evaluation as complementary tool of diagnosis/treatment response in OSAS.

Saturated salt solution: a further step to a formaldehyde-free embalming method for veterinary gross anatomy

In the field of veterinary anatomy, most of the specimens used in practical sessions are perfused with fixatives. Thus, they can be used for a longer time_, reducing the number of animals for educational purposes. Formalin is the most commonly used fixative, consisting of a 37% formaldehyde solution. However, formaldehyde is a powerful irritant of the eyes and airways and is considered carcinogenic, causing nasopharyngeal cancer in exposed workers and professionals. In the present study, we explored an alternative method to avoid the use of formaldehyde in specimens used for gross anatomy practical sessions. We propose an inexpensive, non-toxic fixative that is available worldwide, such as sea salt. This method consists of a continuous perfusion of saturated salt solution for a period of 6-8 h, enabling drainage of the solution to avoid a weight increase of the specimen, and allowing salt to be retained in the tissue. The method is based on recirculation of the saturated salt solution instead of maceration. Perfused specimens retained their natural consistency and joint mobility, with no blood, resembling a piece of meat from the slaughterhouse. They could be used immediately without a maceration period, or stored in the fridge until use and then kept in a bath of saturated salt solution for future conservation. In the case of the former, no refrigeration was needed. The specimens did not have an irritating or offensive smell, and could be used for long sessions (several hours per day) and stored for long periods. However, the blood vessels used for perfusion determine the results: a less invasive approach (through common carotid arteries) gave good preservation of the musculoskeletal system, whereas more invasive access to cannulate the abdominal aorta and vena cava caudalis was required to achieve better preservation of the viscera. In conclusion, we propose that perfusion followed by immersion in a saturated salt solution is a good alternative method for the preservation of specimens used in the practical teaching of gross veterinary anatomy. It is a very simple and inexpensive technique, and is much healthier for users than traditional formalin. Moreover, specimens can be preserved for prolonged periods, and maintain a similar appearance and consistency to fresh material.

Diabetic foot ulcer development risk classifications' validation: A multicentre prospective cohort study

AIMS

To prospectively validate the existing classifications to stratify subjects with diabetes mellitus (DM) by their risk of diabetic foot ulcer (DFU), in high and low risk settings.

METHODS

A prospective multicentre cohort study was conducted, including 446 subjects with DM without active DFU followed in the hospital or primary care setting. Demographic, clinical characterization variables, and those included in the classifications were collected at baseline. Subjects were followed for 1year, until DFU or death.

RESULTS

In our sample, with a mean age of 65years, 52% were male; 32 developed a DFU, 7 required an amputation and 18 died. Differences were found between participants' characteristics and classifications' accuracy according to the setting. The great majority of the variables were associated with higher DFU risk. Globally, classifications were highly and equally valid, positive predictive values (PV) were inferior to 40%, negative PV superior to 90% and area under the receiver operating characteristic curve superior to 0.75.

DISCUSSION

All the existing classifications are valid to be applied in high risk clinical context and have a very high capacity to categorize as low risk those subjects that will not develop a DFU. Further research is needed in the primary care setting.

Three-dimensional scaffolds of fetal decellularized hearts exhibit enhanced potential to support cardiac cells in comparison to the adult

A main challenge in cardiac tissue engineering is the limited data on microenvironmental cues that sustain survival, proliferation and functional proficiency of cardiac cells. The aim of our study was to evaluate the potential of fetal (E18) and adult myocardial extracellular matrix (ECM) to support cardiac cells. Acellular three-dimensional (3D) bioscaffolds were obtained by parallel decellularization of fetal- and adult-heart explants thereby ensuring reliable comparison. Acellular scaffolds retained main constituents of the cardiac ECM including distinctive biochemical and structural meshwork features of the native equivalents. In vitro, fetal and adult ECM-matrices supported 3D culture of heart-derived Sca-1(+) progenitors and of neonatal cardiomyocytes, which migrated toward the center of the scaffold and displayed elongated morphology and excellent viability. At the culture end-point, more Sca-1(+) cells and cardiomyocytes were found adhered and inside fetal bioscaffolds, compared to the adult. Higher repopulation yields of Sca-1(+) cells on fetal ECM relied on β1-integrin independent mitogenic signals. Sca-1(+) cells on fetal bioscaffolds showed a gene expression profile that anticipates the synthesis of a permissive microenvironment for cardiomyogenesis. Our findings demonstrate the superior potential of the 3D fetal microenvironment to support and instruct cardiac cells. This knowledge should be integrated in the design of next-generation biomimetic materials for heart repair.

Alpha-1 antitrypsin deficiency caused by a novel mutation (p.Leu263Pro): Pi*ZQ0gaia - Q0gaia allele

Severe alpha-1 antitrypsin deficiency (AATD) is generally associated with PI*ZZ genotype and less often with combinations of PI*Z, PI*S, and other rarer deficiency or null (Q0) alleles. Severe AATD predisposes patients to various diseases, including pulmonary emphysema. Presented here is a case report of a young man with COPD and AATD. The investigation of the AATD showed a novel mutation p.Leu263Pro (c.860T>C), which was named Q0gaia (Pi*ZQ0gaia). Q0gaia is associated with very low or no detectable serum concentrations of AAT.

Iodine intake in Portuguese pregnant women: results of a countrywide study

BACKGROUND

Iodine is the key element for thyroid hormone synthesis, and its deficiency, even moderate, is harmful in pregnancy, when needs are increased, because of its potential deleterious effects on fetal brain development. In Portugal, no recent data on iodine intake exists. The objective of this countrywide study was to analyze iodine status in pregnant Portuguese women in order to propose adequate measures to the health authorities.

SUBJECTS AND METHODS

Using a fast colorimetric method, urine iodine concentration (UIC) was evaluated in 3631 pregnant women followed in 17 maternity hospitals from hinterland and coastal areas in Continental Portugal and the Portuguese islands of Açores and Madeira.

RESULTS

Median UIC value was 84.9 μg/l (range 67.6-124.1) in Continental Portugal, 69.5 μg/l in Madeira, and 50.0 μg/l in Açores. The percentage of satisfactory values (>150 μg/l) was 16.8, ranging from 8.8 to 34.1 in the Continent, and being 8.2 in Madeira and 2.3 in Açores. The percentage of values below 50 μg/l was 23.7, ranging from 14.0 to 37.4 in the Continent, 33.7 in Madeira, and 50.0 in Açores.

CONCLUSIONS

Our results point to an inadequate iodine intake in pregnant women assisted in most Portuguese maternity hospitals. Considering the potential deleterious effects of inadequate iodine supply in pregnancy, iodine supplementation is strongly recommended in this period of life.

C/EBPbeta is over-expressed in gastric carcinogenesis and is associated with COX-2 expression

The CCAAT/enhancer-binding protein beta (C/EBPbeta) transcription factor has been associated with several cancer models. In this study, the expression of C/EBPbeta was analysed in a series of 90 gastric carcinomas (GCs). We also assessed the effect of C/EBPbeta on COX-2 expression. In normal gastric mucosa, C/EBPbeta expression was restricted to cells in the proliferative zone. In intestinal metaplasia, dysplasia, and GC of the intestinal and atypical subtypes, C/EBPbeta was over-expressed (p < 0.0001, for the association with histological type). C/EBPbeta and Ki67, a marker of cell proliferation, were also co-expressed in primary GC. We also observed an overlap between C/EBPbeta and COX-2 expression in GC. Using GC cell lines we show that C/EBPbeta can regulate the expression of endogenous COX-2 and transactivate the promoter of the COX-2 gene, depending on its methylation status. These results suggest that C/EBPbeta may be a marker of neoplastic transformation and also play an active role in gastric tumourigenesis by regulating COX-2 expression.

Germline E-cadherin mutations in hereditary diffuse gastric cancer: assessment of 42 new families and review of genetic screening criteria

BACKGROUND

Mutations in the E-cadherin (CDH1) gene are a well documented cause of hereditary diffuse gastric cancer (HDGC). Development of evidence based guidelines for CDH1 screening for HDGC have been complicated by its rarity, variable penetrance, and lack of founder mutations.

METHODS

Forty three new gastric cancer (GC) families were ascertained from multiple sources. In 42 of these families at least one gastric cancer was pathologically confirmed to be a diffuse gastric cancer (DGC); the other family had intestinal type gastric cancers. Screening of the entire coding region of the CDH1 gene and all intron/exon boundaries was performed by bi-directional sequencing.

RESULTS

Novel mutations were found in 13 of the 42 DGC families (31% overall). Twelve of these mutations occur among the 25 families with multiple cases of gastric cancer and with pathologic confirmation of diffuse gastric cancer phenotype in at least one individual under the age of 50 years. The mutations found include small insertions and deletions, splice site mutations, and three non-conservative amino acid substitutions (A298T, W409R, and R732Q). All three missense mutations conferred loss of E-cadherin function in in vitro assays. Multiple cases of breast cancers including pathologically confirmed lobular breast cancers were observed both in mutation positive and negative families.

CONCLUSION

Germline truncating CDH1 mutations are found in 48% of families with multiple cases of gastric cancer and at least one documented case of DGC in an individual under 50 years of age. We recommend that these criteria be used for selecting families for CDH1 mutational analysis.

Bulging mesothelial cells of the visceral pleura of the rat mimic the network of subpleural lymphatics

The mesothelial surface of the visceral pleura of the Wistar rat was viewed at high resolution by scanning electron microscopy (SEM). The pleural surface showed exquisite linear arrangements made up of bulging mesothelial cells. They were organized in irregular circles that often presented anastomotic junctures. This arrangement of pleural mesothelial cells mimics the organization of subpleural lymphatics of the lung. A low density of microvilli was seen inside the irregular circles, contrasting with the microvilli-rich mesothelial cells seen on or outside these arrangements. These SEM features of the mesothelium may be related with the formation of microdomains for fluid absorption across the visceral pleura into subpleural lymphatics.

In utero and postnatal exposure of Wistar rats to low frequency/high intensity noise depletes the tracheal epithelium of ciliated cells

Chronic exposure of men or rodents to low frequency/high intensity (LFHI) noise causes a number of systemic changes that make up the so-called vibroacoustic disease (VAD), a disorder that includes alterations of the respiratory system, namely, of its epithelial layer. We have investigated here the susceptibility of the tracheal epithelium of Wistar rats to in utero and postnatal exposure to LFHI noise by comparing its ultrastructure with that of the tracheal epithelium of control rats and of animals exposed to LFHI noise only after reaching adulthood (8 weeks of age). Scanning electron microscopy (SEM) of the inner surface of rat trachea was used to determine the relative areas covered by ciliated and non-ciliated cells. In rats that were exposed in utero and postnatally to LFHI noise, we observed that out of 100 microm(2) of tracheal epithelium only 31 +/- 14 microm(2) were covered by cilia, whereas in control rats; ciliated cells occupied an average of 60 +/- 18 microm(2) out of 100 microm(2) of the epithelium; this difference between the two groups was statistically significant (p <0.05). In rats that were exposed to LFHI noise only after reaching adulthood, cilia covered 55 +/- 22 microm(2) out of 100 microm(2) of the luminal surface of the trachea, a value that, although lower than that of controls, was not found to be statistically different. We conclude that (1) the tracheal ciliated cells are damaged by exposure of rats to LFHI noise if the animals are kept under this environmental aggression during in utero and postnatal periods; (2) tracheal ciliated cells from adult rats are more resistant to the deleterious effects of LFHI noise than pleura or lung alveolar cells that were shown before to undergo marked changes upon chronic exposure of rats to LFHI noise. These findings suggest a note of caution regarding pregnant women and young children: they should be prevented from areas where LFHI noise occurs, namely, in aircraft and textile industries where this type of environmental hazard is often present.

Detection of circulant tumor necrosis factor-alpha, soluble tumor necrosis factor p75 and interferon-gamma in Brazilian patients with dengue fever and dengue hemorrhagic fever

Pro-inflammatory cytokines are believed to play an important role in the pathogenesis of dengue infection. This study reports cytokine levels in a total of 54 patients examined in Recife, State of Pernambuco, Brazil. Five out of eight patients who had hemorrhagic manifestations presented tumor necrosis factor-alpha (TNF-alpha) levels in sera which were statistically higher than those recorded for controls. In contrast, only one out of 16 patients with mild manifestations had elevated TNF-alpha levels. The levels of interleukin-6 (IL), IL-1beta tested in 24 samples and IL-12 in 30 samples were not significantly increased. Interferon-g was present in 10 out of 30 patients with dengue. The data support the concept that the increased level of TNF-alpha is related to the severity of the disease. Soluble TNF receptor p75 was found in most patients but it is unlikely to be related to severity since it was found with an equivalent frequency and levels in 15 patients with dengue fever and another 15 with dengue hemorrhagic fever.

Molecular mechanisms of invasion by cancer cells, leukocytes and microorganisms

Invasion is a phenotype common to cancer cells, leukocytes, parasites, bacteria and viruses, involving cell-cell adhesion, cell-matrix adhesion, proteolysis and motility. These activities are regulated by the cross talk between invaders and host. We discuss the invasion-related molecular interactions of E-cadherin, integrins, matrix metalloproteinases and the chemokine receptor RANTES.

Diversity of cyanobacterial hydrogenases, a molecular approach

In an effort to elucidate the diversity of cyanobacterial hydrogenases, we used a molecular approach. Filamentous strains from a broad range of sources were screened for the presence of hup (uptake hydrogenase), xisC (rearrangement within hupL), and hox (bidirectional hydrogenase) genes. As expected, an uptake hydrogenase seems to be present in all N(2)-fixing cyanobacteria. On the other hand, no evidence was found for the presence of a conventional bidirectional enzyme in several strains. Similarly, the presence of xisC is not a characteristic shared by all the heterocyst-forming cyanobacteria. Although tempting, it is not possible to establish a correlation between the presence/absence of the bidirectional hydrogenase and the occurrence of xisC. The natural molecular variation of hydrogenases in cyanobacteria is certainly a field to explore, both to understand the physiological functions of the respective enzymes and to identify a genetic background to be used when constructing a strain for photobiological H(2) production in a bioreactor.

[Status epilepticus in the childhood. A review of seven years]

INTRODUCTION

Status epilepticus is a neurological emergency that requires early and prompt treatment.

PATIENTS AND METHODS

This retrospective study includes 32 children treated for status epilepticus at Hospital Geral de Santo António, from January 1992 to December 1998. We evaluated the clinical features, duration, aetiology and prognostic.

RESULTS

Symptomatic or criptogenetic aetiology was present in 53% of children and idiopathic in 47%. 27% of episodes of status epilepticus were induced by fever. The most common neurological sequel was epilepsy (onset of new epilepsy in 20%; aggravated in 25%). Two children (10%) had major neurological sequelae after status epilepticus.

CONCLUSION

In our study the duration of status epilepticus and sequelae seems to be related with aetiology.

Effects of low frequency noise upon the reaction of pleural milky spots to mycobacterial infection

INTRODUCTION

Milky Spots (m.s.), also known as Kampmeier's foci, are confined to the parietal leaflet and act as a barrier to mediastinum infections, having very important phagocytic functions. Previous studies have made clear that large pressure amplitude and low frequency (LPALF) noise (> or = 90 dB, < or = 500 Hz) induces morphofunctional changes on the pleural mesothelium. The purpose of this study was to investigate the dynamics of m.s., namely the response to infectious agents reaching the pleural space under noise stress.

METHODS

Wistar rats (n = 20) were used; 5 as control and sham operated, 5 exposed to infection but not to noise, 5 exposed to 1696 cumulative hours of LPALF noise, and 5 exposed to 2184 cumulative hours. Following noise exposures, all rats except the 5 controls were injected with 0.2 ml of saline solution containing 2 x 10(8) viable mycobacterium avium bacilli (ATCC-25291 strain, sereotype 2). The rats were sacrificed 21 d after infection and sections of the retrocardiac pleural leaflets were observed with a light microscope using the Ziehl-Neelsen staining method.

RESULTS

There was an increase in the number and diameter of the m.s. due to hypercellularity, mainly caused by the increase of mononuclear cells, and there was formation of large granulomas containing many mycobacteria. Rats submitted to noise also presented alterations of the standard morphological changes, namely partial necrosis of the m.s.

CONCLUSION

The data suggest that exposure to LPALF noise can interfere with the normal immune response to bacterial infection in rats. This can be an important contribution to the understanding of the disorders in the pleural space of vibroacoustic disease patients.

Pure red cell aplasia due to persistent B19 parvovirus infection in patient infected with human immunodeficiency virus type 1. Recovery with alpha-interferon therapy

B19 parvovirus (PV) infection is ordinarily resolved with the production of specific antibodies that neutralize virus infectivity for erythroid host cells. Nevertheless persistent infection with B19 PV and pure red blood cell aplasia have been documented. A 27 year-old male. i.v. drug abuser, HIV+ and HCV was diagnosed of pure red cell aplasia. Six months later we had serologic evidence of persistent parvovirus infection. Interferon therapy, started for HCV infection, showed a marked improvement of anaemia and anti parvovirus IgM became negative. It is discussed the possible role of interferon therapy in persistent parvovirus infection.

Poliovirus type 1 isolated from a vaccine-associated case of paralytic poliomyelitis in Brazil

This study reports a type 1 poliovirus strain isolated in Brazil from a case classified as vaccine-associated paralytic poliomyelitis (VAPP). After serotyping of the viral isolate with hyperimmune equine sera, PCR and molecular hybridization techniques characterized the strain as P1/Sabin-derived. The isolate was partially sequenced to identify mutations at nucleotides 480, 525 and 6203, which are important for reversion of the P1/Sabin strain to neurovirulence. In a recent study, a P1/Sabin-derived strain isolated from the central nervous system of a VAPP case did not mutate at these positions, but maintained 480-G and 525-U (and 6203-C), suggesting that these mutations are not essential for the occurrence of disease (Georgescu et al., (1994), Journal of Virology, 68: 8089-8101). Although the Brazilian strain also maintained 480-G and 525-U (and 6203-C) and was isolated from the stool, the possibility that this isolate invaded the central nervous system after replicating in the gut, causing the paralysis, cannot be ruled out. This is the first report of a type 1 VAPP case in Brazil, although some cases caused by type 2 and type 3 strains have been described.

Experimental modulation of the reactivity of pleural milky spots (Kampmeier's foci) by Freund's adjuvants, betamethasone and mycobacterial infection

We studied the response of milky spots in the parietal pleura of the rat and mouse to intrapleural instillation of immunomodulatory agents such as complete or incomplete Freund's adjuvants and betamethasone, and also to infection by mycobacteria (M. avium). Both incomplete (mineral oil) and complete (mineral oil plus dead mycobacteria) adjuvants, as well as M. avium infection, induced a striking increase in the size and cellularity of the pleural milky spots whereas betamethasone caused a slight atrophy. The extensive inflammatory infiltrates observed after adjuvant injection differed between milky spots reactive to complete and incomplete Freund's adjuvants. Fifteen days after adjuvant administration, the pleural milky spots of rats were still enlarged and hypercellular but differences were noted in the size of milky spots of the pleura between the 2 adjuvant treatments: animals submitted to injection of complete Freund's adjuvant showed an increase in the size of milky spots from d 3 to d 15, while the size of milky spots of the incomplete Freund's adjuvant treated group showed a decrease in size from d 3 to d 15. The milky spots at d 15 were well organised: reticulin fibres permeated the whole area of the milky spot and the different cell types were evenly distributed. Histiocytes, which were previously confined to the inner layer, were now the main cell type in all areas of milky spots. A moderate number of mast cells and a few eosinophils were also seen. Complete Freund's adjuvant caused the formation of granulomas in the milky spots, a change that was not detected in animals treated with incomplete adjuvant.(ABSTRACT TRUNCATED AT 250 WORDS)

Oligonucleotide probes for the specific detection of the wild poliovirus types 1 and 3 endemic to Brazil

Synthetic oligodeoxynucleotide probes, 21-23 nucleotides in length, were prepared which specifically hybridize to the genomes of the wild type 1 and 3 polioviruses currently endemic to the northeastern region of Brazil. The probes are complementary to sequences near the 5'-terminus of the VP1 gene that differ substantially among genetically distant polioviruses but are largely conserved among related isolates. The probes have been routinely used in the laboratory surveillance of poliomyelitis cases in Brazil, permitting direct, rapid identification of the indigenous wild polioviruses by dot-blot hybridization.

Effects of the venom of the Brazilian scorpion Tityus serrulatus and two of its fractions on the isolated diaphragm of the rat

1. The effects of Tityus serrulatus venom and of two of its toxic fractions, toxin gamma (Tx gamma) and T2III1, on the rat isolated diaphragm were examined. 2. The crude venom (5 ng) facilitated the neuromuscular transmission and increased the twitch tension evoked by retrograde injection of Ach. 3. Tx gamma (25-100 ng) and fraction T2III1 (2.5 ng) also facilitated the neuromuscular transmission but only fraction T2III1 increased the twitch tension evoked by retrograde injection of Ach. 4. Tx gamma (50 ng) and fraction T2III1 (2.5 ng) produced a tetrodotoxin-sensitive increase in the frequency of miniature endplate potentials (m.e.p.p.) and a transitory reduction of the resting potential. The latter effect of the fractions was prevented by treating muscles with tetrodotoxin or D-tubocurarine. Fraction T2III1 also produced a tetrodotoxin-resistance increase of m.e.p.p. amplitude. 5. These results suggest that Tx gamma enhances Ach output through the activation of Na+ channels in the motor nerve terminals. Fraction T2III1 produced effects similar to those induced by Tx gamma but also acted at postjunctional sites, probably by increasing subsynaptic membrane sensitivity to the neurotransmitter.

Randomised trial of alternative formulations of oral poliovaccine in Brazil

In February to July, 1986, an outbreak of type 3 poliomyelitis occurred in north-east Brazil that was linked to type-specific failure of trivalent oral polio vaccine (TOPV). To see if alternative vaccines would improve seroconversion to type 3, 441 children less than 5 years of age who had previously received no or up to four doses of TOPV were randomly assigned to receive one dose of standard TOPV (1,000,000, 100,000, and 300,000 median tissue culture infection doses [TCID50] of types 1, 2, and 3, respectively); a new formulation of TOPV containing twice the dosage of type 3 (600,000 TCID50); or a monovalent vaccine containing 300,000 TCID50 of type 3. While rates of seroconversion to types 1 or 2 were equivalent following vaccination with either formulation of TOPV, children who received the new formulation were 2.7 times more likely to seroconvert to type 3. Similar differences for type 3 were observed when monovalent vaccine was compared with standard TOPV, though both groups had received the same dose of type 3 antigen. The low rate of seroconversion to type 3 in the standard TOPV group was associated with a higher rate of reinfection with type 2, which also appeared to interfere to some extent with seroconversion to type 1. These findings extend earlier observations that interference from Sabin type 2 virus may be an important contributory cause of type-specific TOPV failure, and suggest that interference can be overcome with alterations in the formulation.