Reviewing the use of zebrafish for the detection of neurotoxicity induced by chemical mixtures through the analysis of behaviour

The knowledge and assessment of mixtures of chemical pollutants in the aquatic environment is a complex issue that is often challenging to address. In this review, we focused on the use of zebrafish (Danio rerio), a vertebrate widely used in biomedical research, as a model for detecting the effects of chemical mixtures with a focus on behaviour. Our aim was to summarize the current status of the ecotoxicological research in this sector. Specifically, we limited our research to the period between January 2012 and September 2023, including only those works aimed at detecting neurotoxicity through behavioural endpoints, utilizing zebrafish at one or more developmental stages, from egg to adult. Additionally, we gathered the findings for every group of chemicals involved and summarized data from all the works we included. At the end of the screening process 101 papers were considered eligible for inclusion. Results show a growing interest in zebrafish at all life stages for this kind of research in the last decade. Also, a wide variety of different assays, involving different senses, was used in the works we surveyed, with exposures ranging from acute to chronic. In conclusion, the results of this study show the versatility of zebrafish as a model for the detection of mixture toxicity although, for what concerns behavioural analysis, the lack of standardisation of methods and endpoints might still be limiting.

Cardiopulmonary Exercise Testing after Surgical Repair of Tetralogy of Fallot-Does Modality Matter?

BACKGROUND

Despite a successful repair of tetralogy of Fallot (rToF) in childhood, residual lesions are common and can contribute to impaired exercise capacity. Although both cycle ergometer and treadmill protocols are often used interchangeably these approaches have not been directly compared. In this study we examined cardiopulmonary exercise test (CPET) measurements in rToF.

METHODS

Inclusion criteria were clinically stable rToF patients able to perform a cardiac magnetic resonance imaging (CMR) and two CPET studies, one on the treadmill (incremental Bruce protocol) and one on the cycle ergometer (ramped protocol), within 12 months. Demographic, surgical and clinical data; functional class; QRS duration; CMR measures; CPET data and international physical activity questionnaire (IPAQ) scores of patients were collected.

RESULTS

Fifty-seven patients were enrolled (53% male, 20.5 ± 7.8 years at CPET). CMR measurements included a right ventricle (RV) end-diastolic volume index of 119 ± 22 mL/m2, a RV ejection fraction (EF) of 55 ± 6% and a left ventricular (LV) EF of 56 ± 5%. Peak oxygen consumption (VO2)/Kg (25.5 ± 5.5 vs. 31.7 ± 6.9; p < 0.0001), VO2 at anaerobic threshold (AT) (15.3 ± 3.9 vs. 22.0 ± 4.5; p < 0.0001), peak O2 pulse (10.6 ± 3.0 vs. 12.1± 3.4; p = 0.0061) and oxygen uptake efficiency slope (OUES) (1932.2 ± 623.6 vs. 2292.0 ± 639.4; p < 0.001) were significantly lower on the cycle ergometer compared with the treadmill, differently from ventilatory efficiency (VE/VCO2) max which was significantly higher on the cycle ergometer (32.2 ± 4.5 vs. 30.4 ± 5.4; p < 0.001). Only the VE/VCO2 slope at the respiratory compensation point (RCP) was similar between the two methodologies (p = 0.150).

CONCLUSIONS

The majority of CPET measurements differed according to the modality of testing, with the exception being the VE/VCO2 slope at RCP. Our data suggest that CPET parameters should be interpreted according to test type; however, these findings should be validated in larger populations and in a variety of institutions.

Recurrent thoracic air leak syndrome in patients affected by pulmonary graft-versus-host disease: Surgical strategies and outcome

BACKGROUND AND AIMS

Thoracic air leak syndrome (TALS) is a complication related to chronic pulmonary graft-versus-host disease (pGvHD) that affects approximately 0.83%-3.08% patients after allogenic hematopoietic stem cell transplant. Such complication is defined as the occurrence of any form of air leak in the thorax, including spontaneous pneumomediastinum or pneumopericardium, subcutaneous emphysema, interstitial emphysema and pneumothorax and has a negative impact on post-transplant survival. The aim of the present study is to describe a single-center experience in the surgical management of recurrent TALS in adolescents and young adults and its outcome.

METHODS

We retrospectively reviewed the clinical notes of patients with previous allogenic hematopoietic stem cell transplant who underwent surgical procedures for recurrent TALS from January 2016 until March 2021. We analyzed clinical data, number of episodes of thoracic air leak, surgical procedures and relative outcome.

RESULTS

In the examined period, four patients, aged 16-25 years, underwent surgical procedures for TALS, including thoracostomy tube placement, thoracoscopic pleurodesis and thoracotomy. All the patients had been diagnosed with pGvHD before the onset of TALS, with a mean time lapse of 276 days (range 42-513). These patients experienced on average 4.5 air leak episodes (range 3-6). All the patients experienced at least two episodes before surgery. One patient underwent emergency tube thoracostomy only, three patients underwent thoracoscopic pleurodesis and two patients underwent thoracotomy. After surgery, patients were free from air leak symptoms for a mean time of 176 days (range 25-477). Pulmonary function progressively deteriorated, and all the patients eventually died because of respiratory failure after a mean time of 483 days (range 127-1045) after the first episode of air leak.

CONCLUSIONS

Surgery provides temporary relief to symptoms related to TALS but has limited effects on the underlying pathophysiologic process. The development of TALS in a sign of progressive pulmonary function worsening and is associated with high risk of respiratory failure and mortality.

Differences in Physical Activity Levels between Healthy and Transplanted Children: Who Needs More Tips?

BACKGROUND

Advances in the medical-surgical field have significantly increased the life expectancy of patients undergoing solid organ transplantation but this exposes patients to long-term complications due to chronic therapies and changes in lifestyle. It is known that children affected by pathology tend to be more sedentary and inactivity represents a further risk factor for the onset of non-communicable diseases. The aim of the present study was to compare the lifestyle of two groups of young patients: one group of healthy subjects (HG) and one group of kidney or liver transplant recipients (TG).

METHODS

Patients were asked to complete Physical Activity Questionnaire for Older Children (PAQ-C).

RESULTS

A total of 104 subjects were recruited (50.9% male, mean age 12.8 ± 3.16 years old). No significant differences were observed in the final score between groups when comparing subjects based on health condition (Healthy 2.69 ± 0.65 vs. Transplant Group 2.42 ± 0.88), the intensity of sports activities (Competitive 2.82 ± 0.59 vs. Not Competitive 2.53 ± 0.7) or type of transplant (Liver 2.51 ± 0.91 vs. Kidney 2.16 ± 0.75).

CONCLUSION

The results of this study showed a worrying reality: children are engaged in low levels of physical activity regardless of their health status and in general the level of activity does not reach the recommended values even in the absence of contraindications. So, it is necessary to encourage healthy children to practice more PA and to introduce PA prescriptions for transplanted children to prevent their health from deteriorating due to sedentariness.

Cardiopulmonary Exercise Testing in Children and Young Adolescents after a Multisystem Inflammatory Syndrome: Physical Deconditioning or Residual Pathology?

Multisystem inflammatory syndrome in children (MIS-C) is a serious health condition that imposes a long-term follow-up. The purpose of our pilot study is to evaluate the usefulness of the cardiopulmonary stress test (CPET) in the follow-up after MIS-C. All patients admitted for MIS-C in our hospital in the 12 months preceding the date of observation were considered for inclusion in the study. Pre-existing cardio-respiratory diseases and/or the lack of collaboration were the exclusion criteria. At enrolment, each subject passed a cardiological examination, rest ECG, echocardiogram, 24 h Holter-ECG, blood tests, and a CPET complete of spirometry. A total of 20 patients met the inclusion criteria (11.76 ± 3.29 years, 13 male). In contrast to the normality of all second-level investigations, CPET showed lower-than-expected peakVO₂ and peak-oxygen-pulse values (50% of cases) and higher-than-expected VE/VCO_2-slope values (95% of cases). A statistically significant inverse correlation was observed between P-reactive-protein values at admission and peakVO₂/kg values (p = 0.034), uric acid values at admission, and peakVO₂ (p = 0.011) or peak-oxygen-pulse expressed as a percentage of predicted (p = 0.021), NT-proBNP values at admission and peakVO₂ expressed as a percentage of predicted (p = 0.046). After MIS-C (4-12 months) relevant anomalies can be observed at CPET, which can be a valuable tool in the follow-up after this condition.

Re-evaluation After 2 Years of COVID-19 Pandemic: Return to Play in Pediatric Population: What's New?

An observational retrospective study was conducted on 180 young competitive athletes. These children were revaluated after a mild/moderate SARS-CoV-2 infection through 3 different kind of protocol aimed at recognizing any cardiorespiratory complications due to the infection. The aim of the present study was to evaluate the results of "return to play" Italian protocols for readmission to competitive sport in the pediatric population. All of the subjects analyzed were readmitted to competitive sports after revaluation. None of the young athletes showed cardiorespiratory compromises at first and/or second level evaluation, confirming that in young population there is low risk of hospitalization and life-threatening complications after a mild/moderate infection. Italian simplified protocol for resuming sport have proved to be a valuable tool for health assessment both in adult and young athletes allowing them to resume their training in safety.

Preliminary Evaluation of Sedentary Lifestyle in Italian Children after Solid Transplant: What Role Could Physical Activity Play in Health? It Is Time to Move

BACKGROUND

Advances in the medical-surgical field have significantly increased survival after solid organ transplantation in the pediatric population. However, these patients are predisposed to the development of long-term complications (e.g., cardiovascular disease). The therapeutic role of physical activity (PA) to counteract these complications is well known. The purpose of the study was to investigate the level of PA in a pediatric population after solid organ transplantation.

METHODS

In the first 4 weeks at the beginning of the school year, the Physical Activity Questionnaire for Older Children and Adolescents was administered to young patients who had previously undergone solid transplants at our institute.

RESULTS

Questionnaires of 49 patients (57.1% female, mean age 13.2 ± 3.5 years) were analyzed and 32.7% of subjects did not perform any exercise during school physical education classes. Only 24% practiced a moderate quantity of exercise in the previous week (2-3 times/week) and 72% engaged in sedentary behaviors during weekends.

CONCLUSIONS

Preliminary data confirmed that young recipients are still far from meeting the minimum indications of the World Health Organization on PA and sedentary behavior. It will be necessary to increase their involvement in PA programs in order not only to increase their life expectancy but also to improve their quality of life.

Late outcome of Extracardiac Fontan Patients: 32 years of follow-up

OBJECTIVES

We sought to evaluate the long-term survival and risk factors for morbidity and mortality in our cohort of patients after Extracardiac (EC) Fontan.

METHODS

We collected and analyzed follow-up data until September 2020 for all patients who underwent EC Fontan operation at our institution from November 1988 to November 2015.

RESULTS

Out of 406 patients treated with EC Fontan at a mean age of 5.4 ± 4.5 years, 372 (91.6%) were discharged home; 15% were lost to follow-up. The Median follow-up was 14.6 years (IQR 8.7-20.3). Two hundred patients (54%) had a good long-term outcome, with an event-free long-term survival, but late adverse events of any kind needing interventional or surgical reoperations were reported in 128 patients (34%). Forty-four patients (12%) developed late Fontan failure. Thirty-seven survivors (10%) had late arrhythmias, with the need for pacemaker implantation. Obstruction of the cavopulmonary pathway occurred in forty-nine patients (13%), but just 8 pts needed conduit surgical replacement. At 32 years, the survival probability was 84%. The risk of orthotopic heart transplant (HT), considering death as a competing event, (showed as cumulative incidence) was 12.5%. A preoperative diagnosis of hypoplastic left heart syndrome (HLHS) was an independent risk factor for the need for HT.

CONCLUSIONS

The EC Fontan shows satisfactory long-term survival and low incidence of adverse events and late failure. Conduit replacement is rare, and its longevity may not represent a substantial issue in these patients. However, as with other technical variants, the need for reoperations during long-term follow-up is a significant challenge.

Competitive sport after SARS-CoV-2 infection in children

BACKGROUND

With the gradual resumption of sports activities after the lock-down period for coronavirus pandemic, a new problem is emerging: Allow all athletes to be able to return to compete after SARS-CoV-2 infection in total safety. Several protocols have been proposed for healed athletes but all of them have been formulated for the adult population. The aim of the present study is to evaluate the adequacy of Italian practical recommendations for return-to-paly, in order to exclude cardiorespiratory complications due to COVID-19 in children and adolescents.

METHODS

Between April 2020 and January 2021 the Italian Sports Medical Federation formulated cardiorespiratory protocols to be applied to athletes recovered from SARS-CoV-2 infection. The protocols take into account the severity of the infection. Protocols include lung function tests, cardiopulmonary exercise test, echocardiographic evaluation, blood chemistry tests.

RESULTS

From September 2020 to February 2021, 45 children and adolescents (aged from 9 to 18 years; male = 26) with previous SARS-CoV-2 infection were evaluated according to the protocols in force for adult. 55.5% of the subjects (N = 25) reported an asymptomatic infection; 44.5% reported a mild symptomatic infection. Results of lung function test have exceeded the limit of 80% of the theoretical value in all patients. The cardiorespiratory capacity of all patients was within normal limits (average value of maximal oxigen uptake 41 ml/kg/min). No arrhythmic events or reduction in the ejection fraction were highlighted.

CONCLUSION

The data obtained showed that, in the pediatric population, mild coronavirus infection does not cause cardiorespiratory complications in the short and medium term. Return to play after Coronavirus infection seems to be safe but it will be necessary to continue with the data analysis in order to modulate and optimize the protocols especially in the pediatric field.

[Physical activity in patients with repaired and unrepaired congenital heart diseases. Task Force for exercise prescription in patients with congenital heart disease of the Italian Society of Pediatric Cardiology and Congenital Heart Disease]

Regular physical activity is essential for physical health and mental wellbeing in children and teenagers. However, patients with congenital heart disease are often restricted from being physically active due to parental overprotection and lack of physical activity promotion or exercise prescription from their physicians. A comprehensive medical evaluation is crucial for the development of personalized exercise programs for these patients. The aim of this review is to provide physicians with a practical guide on how to promote physical activity and prescribe exercise for patients with congenital heart disease with or without surgical correction.

Impact of complex congenital heart disease on the prevalence of arterial hypertension after aortic coarctation repair

OBJECTIVES

This study was designed to evaluate the difference in the prevalence of long-term arterial hypertension among patients with corrected aortic coarctation according to the existence of associated cardiac congenital lesions.

METHODS

We identified 235 patients who had undergone surgery for aortic coarctation and classified them into 2 groups: patients with isolated coarctation of the aorta (CoA) and patients with aortic coarctation associated with complex congenital heart disease. Data were retrospectively analysed.

RESULTS

There were 148 subjects with isolated CoA and 87 with complex CoA (CoA-c). Patients were defined as hypertensive if they required antihypertensive treatment and/or when blood pressure was above 95th percentile. Patients with isolated aortic coarctation were significantly younger than patients with CoA-c (P < 0.001) and a markedly higher prevalence of arterial hypertension (44% vs 24%) was documented in the isolated coarctation group. The difference in the prevalence of hypertension in the 2 groups was still significant after correcting for differences in age (P < 0.001), confirming that the prevalence of arterial hypertension in patients with CoA-c was half of that of patients with isolated CoA.

CONCLUSIONS

We conclude that complex congenital heart disease in patients who have undergone surgical correction for aortic coarctation results in a significantly lower prevalence of late-onset hypertension. Reduced systemic flow and pressure before surgery in patients with CoA-c might be associated with a lower rate of arterial hypertension.

Non-equilibrium turbulence scalings and self-similarity in turbulent planar jets

We study the self-similarity and dissipation scalings of a turbulent planar jet and the theoretically implied mean flow scalings. Unlike turbulent wakes where such studies have already been carried out (Dairay et al. 2015 J. Fluid Mech. 781, 166-198. (doi:10.1017/jfm.2015.493); Obligado et al. 2016 Phys. Rev. Fluids 1, 044409. (doi:10.1103/PhysRevFluids.1.044409)), this is a boundary-free turbulent shear flow where the local Reynolds number increases with distance from inlet. The Townsend-George theory revised by (Dairay et al. 2015 J. Fluid Mech. 781, 166-198. (doi:10.1017/jfm.2015.493)) is applied to turbulent planar jets. Only a few profiles need to be self-similar in this theory. The self-similarity of mean flow, turbulence dissipation, turbulent kinetic energy and Reynolds stress profiles is supported by our experimental results from 18 to at least 54 nozzle sizes, the furthermost location investigated in this work. Furthermore, the non-equilibrium dissipation scaling found in turbulent wakes, decaying grid-generated turbulence, various instances of periodic turbulence and turbulent boundary layers (Dairay et al. 2015 J. Fluid Mech. 781, 166-198. (doi:10.1017/jfm.2015.493); Vassilicos 2015 Annu. Rev. Fluid Mech. 95, 114. (doi:10.1146/annurev-fluid-010814-014637); Goto & Vassilicos 2015 Phys. Lett. A 3790, 1144-1148. (doi:10.1016/j.physleta.2015.02.025); Nedic et al. 2017 Phys. Rev. Fluids 2, 032601. (doi:10.1103/PhysRevFluids.2.032601)) is also observed in the present turbulent planar jet and in the turbulent planar jet of (Antonia et al. 1980 Phys. Fluids 23, 863055. (doi:10.1063/1.863055)). Given these observations, the theory implies new mean flow and jet width scalings which are found to be consistent with our data and the data of (Antonia et al. 1980 Phys. Fluids 23, 863055. (doi:10.1063/1.863055)). In particular, it implies a hitherto unknown entrainment behaviour: the ratio of characteristic cross-stream to centreline streamwise mean flow velocities decays as the -1/3 power of streamwise distance in the region, where the non-equilibrium dissipation scaling holds.

Association between nocturnal blood pressure dipping and insulin resistance in children affected by NAFLD

The aim of this study was to analyse the relationship between insulin-glucose metabolism, nocturnal blood pressure dipping and nonalcoholic fatty liver disease (NAFLD) in obese adolescents without diabetes. One hundred one consecutive children, with biopsy-proven NAFLD, were included in this study. Blood samples were drawn for the analyses of liver function tests, insulin-glucose metabolism and lipid profile appraisal. An ambulatory blood pressure measurement (ABPM) was performed. Seventy-six children (75.3 %) were systolic nondippers, and 23 of them were diastolic nondippers (30.3 %). No differences were found in the anthropometric parameters between the two groups. When compared to the systolic dippers, the systolic nondippers had higher medians of mean nocturnal blood pressure, glucose at 0, 60 and 120 min in the oral glucose tolerance test (OGTT), OGTT insulin at all time points and insulin-resistance values. No correlation of histopathological features with dipping/nondipping statuses was found.

CONCLUSIONS

We found an association between a nocturnal blood pressure fall and measures of insulin levels, independent of obesity, or daytime blood pressure levels, among the obese patients with NAFLD. Although no association between nondipping profiles and NAFLD was observed in our study, further studies with a longer term follow-up are needed, to better elucidate the complex link between these particular entities.

Early left ventricular abnormality/dysfunction in obese children affected by NAFLD

BACKGROUND AND AIMS

Although it is generally accepted that non alcoholic fatty liver disease (NAFLD) is linked to increased risk of cardiovascular disease, the presence of abnormalities in cardiac function among NAFLD children is limited and controversial. Aim of the study was to detect cardiac abnormalities/dysfunction in a paediatric population of NAFLD.

METHODS AND RESULTS

Anthropometric, laboratory, cardiovascular fitness, 24 h blood pressure monitoring and Doppler echocardiography parameters were obtained in 50 untreated children (37 males; mean age 12.2 + 2.5) with biopsy-proven NAFLD. Abnormalities in both cardiac function and geometry could be identified in the whole study population: prevalence of about 35% in left ventricular hypertrophy, 14% of concentric remodelling and 16% of left atrial dilatation. Furthermore children with NAFLD (NAS score <5) showed lower cardiac alterations compared to NASH patients (NAS score >5). After adjusting for age, sex and BMI, a positive correlation was found only between LV mass and NAS score (p < 0.001).

CONCLUSION

Our results suggest that cardiac dysfunction can be detectable early in NAFLD children and this is not linked to cardiovascular and metabolic alteration, other than to liver damage. Although as a preliminary stage, we can speculate a possible direct relationship between liver and heart steatosis, already occurring during childhood.

Galectin-3 expression in thyroid fine needle cytology (t-FNAC) uncertain cases: validation of molecular markers and technology innovation

Thyroid cancer is not very common, accounting for 1-2% of all cancers, with a population incidence of about 0.004%. Currently, the ability to discriminate between follicular adenoma and carcinoma represents the major challenge in preclinical diagnosis of thyroid proliferative lesions. Better discrimination between the two would help avoid unnecessary thyroidectomy and save valuable resources. Over the years, galectin-3 (Gal-3) has been proposed as a diagnostic marker with varied success. In this paper, we used Environmental Scanning Electron Microscopy Immunogold Labelling (ESEM-IGL) to investigate the expression of Gal-3 on Thin-Prep fine needle aspiration cytology (FNAC). We optimized the ESEM-IGL method on thyroid cell lines (RO-82 and FTC-133) comparing our membrane Gal-3 labeling data with Western blot. We evaluated 183 thyroid FNAC from Italian patients with a uncertain pre-surgical diagnosis. ESEM-IGL method marker sensitivity is 71.2%, while specificity is 53.3% and diagnostic efficacy is 61.2%. Our results confirmed that Gal-3 expression is associated with situations of hypertrophy and/or cellular hyperproliferation, pathophysiological situations common both to adenomas and to thyroid carcinomas. The innovation of thyroid FNAC Thin-Prep ESEM-IGL shows the levels of Gal-3 immunolabeling clearly, even through the individual cells of a thyroid nodule. However, Gal-3 alone, as a molecular marker of thyroid cancer, can still have a limited application in pre-surgery diagnosis.

Impaired energy expenditure despite normal cardiovascular capacity in children with type 1 diabetes

BACKGROUND

Benefit of fitness on children with type 1 diabetes mellitus (T1DM) is still debated.

AIM

To evaluate the influence of physical activity on metabolic balance and exercise tolerance in prepubertal children affected by T1DM.

METHODS

We analyzed 35 pre-/peripubertal T1DM children and 31 matched controls using an activity monitor (SenseWear Armbad) and physical activity questionnaire (PAQ) to assess energy expenditure (EE), total and active, sedentary and physical activities (h/day and Mets = metabolic equivalents). The maximal cardiopulmonary exercise test (CPET) was also performed.

RESULTS

Total physical activities and total and active EE (>3 Mets) resulted higher in controls than in T1DM patients and self-reported perception of physical and sedentary activities was altered in T1DM children as well in controls and were different from the measured data. No differences were found in CPET parameters with the exception of a higher maximal blood pressure in T1DM children. In multivariate analysis HbA1c negatively correlated with VO(2).

CONCLUSION

Prepubertal T1DM children seem to have a lower level of physical activity and EE and a probable altered feeling of physical and sedentary activities. On the other hand, T1DM children do not show any alteration of cardiovascular performance, although glycemic control (HbA1c) may play a role in cardiovascular performance.

Energy expenditure and insulin sensitivity evaluation in obese children affected by hepatosteatosis

OBJECTIVES

The aim of our study was to evaluate the physical and sedentary activities and energy expenditure (EE) in a group of children affected by non-alcoholic fatty liver disease (NAFLD), compared with normal and obese subjects, using a physical activity questionnaire (PAQ) and a SenseWear armband (SWA).

METHODS

Forty NAFLD (10 females), 41 lean (NRM; 11 females) and 30 obese (OB; 10 females), age- and pubertal stage-matched, children were included.

RESULTS

Sedentary activity (PAQ) was similar in NAFLD and NRM but less in OB, while SWA showed that NAFLD spent less time in physical activity and more in sedentary activities compared with NRM, but not with OB. Insulin sensitivity index result is related to active EE (cal kg(-1)  d(-1) ) in NAFLD, while homeostatic model assessment index result was negatively related to total EE in OB.

CONCLUSIONS

Regular physical activity must be encouraged in all obese children affected by NAFLD or not, and SWA might be a possible valid tool for evaluating actual EE.

Physical activity, fitness, and dyspnea perception in children with congenital diaphragmatic hernia

We assessed whether physical activity could influence the performance and perception of dyspnea in children who were operated on for high risk congenital diaphragmatic hernia (CDH). We hypothesized that CDH children with normal activity would have better lung function and exercise performance level when compared to sedentary CDH subjects. We studied 18 children (11 males and 7 females, mean age 6.6 ± 2.6 years) who were surgically corrected. All children underwent physical examination, ECG at rest, and a maximal exercise stress test on a treadmill to measure the duration of exercise, maximal heart rate and blood pressure, maximal oxygen uptake (VO(2)  max and VO(2)  ml/kg/min). Lung function testing to measure forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV(1) ), and peak expiratory flow (PEF) was also performed. Following the stress test, the Dalhousie dyspnea and effort scale was shown to children as a pictorial panel with three groups of increasing (from 1 to 7) levels of effort perception, throat discomfort, and chest dyspnea. Children were divided into group A (sedentary) and group B (regular physical participation). There was no difference in CDH severity between the two groups. Group A had a statistically significant lower duration of exercise (P < 0.01), maximal oxygen consumption (VO(2)  max P < 0.0001), VO(2)  ml/kg/min (P < 0.001), higher throat closing feeling (P < 0.004), chest dyspnea (P < 0.001), and effort perception (P < 0.04) compared to group B. No differences were found in lung function tests. In conclusion, our data may suggest that children with a history of CDH who are active maintain a higher level of performance with less perception of dyspnea and effort.

Impression cytology with scanning electron microscopy: a new method in the study of conjunctival microvilli

PURPOSE

Recent studies used impression cytology with scanning electron microscopy (SEM) to study the conjunctival surface of bovine eyes and normal human eyes. The purpose of this study was to evaluate the use impression cytology and SEM (ICSEM) in patients affected by tear film abnormalities.

METHODS

Forty-five patients were divided into three groups according to mild, moderate or severe subjective sensation of dry eye. Fifteen asymptomatic subjects served as control group. In all patients the tear film was evaluated with break-up time (BUT), Schirmer's, and Ferning test, whereas conjunctival epithelium was evaluated with impression cytology and optic microscopy (ICOM), and ICSEM. The Spearman rank correlation test was used to compare the outcome of these examinations with the subjective sensation of dry eye in each group, and to identify correlations among the five tests.

RESULTS

ICSEM findings highly correlated with subjective dry eye sensation (Spearman correlation coefficient, 796; P<0.01). ICSEM revealed incipient epithelial damage (reduction or absence of microvilli) before the appearance of alterations of nucleus and cytoplasm of epithelial cells revealed by optic microscopy. The number of microvilli was correlated with the degree of tear film abnormalities and subjective sensation of dry eye (Spearman correlation coefficient, 796; P<0.01).

CONCLUSION

ICSEM was very effective in detecting the reduction in the number of microvilli. Therefore, it could represent an effective method to detect alterations in the conjunctival epithelium resulting from tear film damage even before the epithelial damage occurs and is detected by optic microscopy.

Accumulation, localisation, and toxic effects of cadmium in the liverwort Lunularia cruciata

Accumulation, tissue and intracellular localisation, and toxic effects of cadmium were investigated in the liverwort Lunularia cruciata. The results of analyses carried out by atomic absorption spectrometry on single plants showed that the cadmium accumulation was dose- and time-dependent. Cadmium localisation was assessed by X-ray scanning electron microscopy microanalysis in gemmalings and in the different tissues of the thallus and by X-ray transmission electron microscopy microanalysis at the cellular level. The metal preferentially accumulated in the hyaline parenchyma and at the base of the gemma cups. Inside the cell, cadmium accumulated in the vacuoles and the cell wall. Metal accumulation was accompanied by a concomitant increase in sulphur content within the vacuoles of stressed cells. Gel-permeation chromatography showed that most of the cadmium was associated with a low-molecular-mass fraction eluting at a ratio of elution volume to void volume corresponding to that of phytochelatins. The excess of sulphur deposited in the vacuoles may well have been caused by the stress-induced synthesis of phytochelatins. At the ultrastructural level, sublethal concentrations of cadmium caused alterations of the fine structure of the cells, inducing marked alterations of the chloroplast structure. Cadmium also induced a dose-dependent inhibition of apical thallus growth and gemma germination.

Allelic association of gene markers on chromosome 11q in Italian families with atopy

In our study, the genetic linkage of the Fcepsilon RIbeta gene with atopy in 77 affected sibling pairs recruited from an Italian panel of 201 subjects has been examined. Atopy was defined by the presence of a positive skin prick test to one or more common aeroallergens, a positive RAST test to one or more common aeroallergens and an elevated circulating total IgE. Genotype analysis was performed by PCR amplification of Fcepsilon RIbeta CA and CI11-319 CA microsatellites. All the family members were also tested for the Ilepsilon 181 mutation with the ARMS method and for Leu181/Leu183 polymorphism. Seventy-two point five percent (72.5%) of the affected sibling pairs shared their maternal allele and 27.5% did not. Therefore, an increased maternal allele sharing was observed: chi2 = 8.10, p < 0.01. Comparing paternal versus maternal allele sharing, a significant difference was observed for the C1II-319 CA marker (chi2 = 4.32, p < 0.05). Atopy phenotype with positive skin prick test, RASTs, and high total serum IgE also showed greater sharing of maternal than paternal alleles in affected sibling pairs. Of the 201 subjects studied, 17 (8.4%) were positive for Leu181. Ten of these were children and seven (70%) had inherited the variant maternally. The seven children had maternally inherited Leu181/Leu183 and were atopic. Within this sample the maternal inheritance of Fcepsilon RIbeta Leu181/Leu183 was associated with an increased risk of IgE responses to common allergens, raised eosinophil counts and increased skin prick test reactions. Therefore, the variant identified a genetic risk factor for atopy.

CONCLUSION

The central role of Fcepsilon RIbeta in atopy and the linkage data presented here point to the possibility that genetic variation in Fcepsilon RIbeta or its controlling element may cause differences in the extent of IgE responses between atopic and non-atopic subjects. A search for such mutations or polymorphisms will need to take into account some carriers of atopy among the normal population and genetic heterogeneity among atopic individuals.

Scanning electron microscopy of the tunica albuginea of the corpora cavernosa in normal and impotent subjects

The tunica albuginea (TA) of the penis is thought to play a major role in the erection mechanism. It functions by compressing the subalbugineae venulae, which promotes the slower venous flow during erection, and provides a fibrous frame to give an inextensible support for the vessels and nerves. It acts as the inextensible enclosing structure which contains the erectile tissue and gives the erect penis its shape. The functions of the TA result from its structure, consisting for the most part of collagenic and elastic fibers. This study investigated, with the aid of scanning electron microscopy (SEM), the microarchitecture of the TA and the spatial relation of its fibers in ten impotent patients and in six control subjects with normal erectile function. The arrangement of elastic fibers in the TA seems to account for their function, which is to prevent the overstretching of collagenic fibers during maximum intracavernous pressure. In impotent patients, a reduction in the elastic fibers in the TA appears to produce disorders in the arrangement of the collagenic fibers. These alterations in the architecture of the TA in impotent patients can give rise top erection disorders.

Cell junctions during the early development of the sea urchin embryo (Paracentrotus lividus)

Thin sections, lanthanum tracer and the freeze-fracture technique revealed the presence of different types of cell junctions in early sea urchin (Paracentrotus lividus) embryos. During the first four cleavage cycles, which are characterized by synchrony of cell division, sister blastomeres were connected only by intercellular bridges, formed as a result of incomplete cytokinesis; no trace of other junctions was found at these stages. From the 16-cell stage onwards, septate junctions and gap junctions began to appear between blastomeres. It is postulated that cell-cell interactions may provide a mechanism for the propagation of signals necessary for the coordination of cell proliferation and differentiation.