Solvent vapour monitoring in work space by solid phase micro extraction.

Solid phase micro extraction (SPME) is a fast, solvent-less alternative to conventional charcoal tube sampling/carbon disulfide extraction for volatile organic compounds (VOC). In this work, SPME was compared to the active sampling technique in a typical lab atmosphere. Two different types of fibre coatings were evaluated for solvent vapour at ambient concentration. A general purpose 100 microm film polydimethylsiloxane (PDMS) fibre was found to be unsuitable for VOC work, despite the thick coating. The mixed-phase carboxen/PDMS fibre was found to be suitable. Sensitivity of the SPME was far greater than charcoal sorbent tube method. Calibration studies using typical solvent such as dichloromethane (DCM), benzene (B) and toluene (T) showed an optimal exposure time of 5 min, with a repeatability of less than 20% for a broad spectrum of organic vapour. Minimum detectable amount for DCM is in the range of 0.01 microg/l (0.003 ppmv). Variation among different fibres was generally within 30% at a vapour concentration of 1 microg DCM/l, which was more than adequate for field monitoring purpose. Adsorption characteristics and calibration procedures were studied. An actual application of SPME was carried out to measure background level of solvent vapour at a bench where DCM was used extensively. Agreement between the SPME and the charcoal sampling method was generally within a factor of two. No DCM concentration was found to be above the regulatory limit of 50 ppmv.

Left ventricular hypertrophy, treadmill tests, and 24-hour blood pressure in pediatric transplant patients.

BACKGROUND: Hypertension and left ventricular hypertrophy (LVH) are possible complications in pediatric patients after renal transplantation. METHODS: We performed left ventricular echocardiography, 24-hour ambulatory blood pressure monitoring (24-hr ABPM), and treadmill tests in 28 pediatric renal transplant patients (mean age 16.1 +/- 3.7; time since transplantation 36 +/- 23 months). Left ventricular mass (LVM) was indexed for height 2.7. RESULTS: LVH was found in 82% of the patients. Seven of these patients were normotensive by 24-hour ABPM, but five patients showed a hypertensive systolic BP response during the treadmill test. LVM/height 2.7 correlated significantly with the mean 24-hour systolic BP (P = 0.002) and with the maximal exercise systolic BP (P = 0.002). CONCLUSION: LVH is frequent in pediatric renal transplant patients. More information is needed with respect to the risk for LVH, including data from 24-hour ABPM and treadmill testing.

Does pattern electroretinogram spatial tuning alteration in Parkinson's disease depend on motor disturbances or retinal dopaminergic loss?

Systemic decrease of dopaminergic cells, such as in Parkinson's disease may produce visual alterations in humans. In order to show possible pattern electroretinogram (PERG) spatial tuning function (STF) alterations due to impaired dopaminergic transmission in humans, we studied a group of Parkinson's disease patients before and during treatment with the dopamine precursor, levodopa, and compared their performances with those of an age-matched control group. Moreover, in order to exclude the possible involvement of motor disabilities to produce PERG alterations, we also investigated PERG responses in post-traumatic parkinsonian patients who exhibited motor abnormalities as a consequence of focal lesions of basal ganglia, in the absence of systemic dopaminergic degeneration. Our results showed a clear decrease of PERG responses in Parkinson's disease patients particularly at medium spatial frequency range (2.7-4.0 cycles/degree) with a substantial preservation of responses at low frequencies. Levodopa therapy reversed these alterations in Parkinson's disease patients, resulting in the recovery of a normal tuning function shape. In contrast to Parkinson's disease, the tuning function appeared to be preserved in post-traumatic parkinsonian patients. Our results clearly establish a relationship between retinal alteration in PD patients and dopaminergic retinal function.

Isolated neonatal atrial flutter: clinical features, prognosis and therapy.

BACKGROUND: Concern exists in literature about the clinical course, the best acute and chronic treatment and the prognosis of idiopathic neonatal atrial flutter. The aim of our study was to evaluate this in a population of our patients with this type of arrhythmia. METHODS: Six infants (3 M, 3 F, mean age 42 +/- 62 days, range 1-150) affected with atrial flutter without structural heart disease were studied and then acutely and chronically treated. The effectiveness of chronic antiarrhythmic treatment was evaluated with Holter monitoring every 3 months for the first year of life and with transesophageal atrial pacing. RESULTS: Mean arrhythmia cycle length was 180 +/- 34 ms with atrioventricular conduction ratio ranging between 1:1 and 3:1. Two patients with clinical signs of heart failure were successfully treated with DC shock. Transesophageal overdrive atrial pacing was successfully used in one patient treated with i.v. propafenone without benefit. In the remaining three patients, cardioversion was achieved with amiodarone after digoxin had failed in all three and propafenone had failed in two of them. To prevent recurrences, we treated four patients with amiodarone, one with amiodarone combined with propranolol and one with digoxin. During the follow-up (22 +/- 11 months), neither arrhythmia recurrences nor side-effects of the therapy occurred. CONCLUSIONS: Neonatal atrial flutter is an arrhythmia with significant acute morbidity but an excellent long-term prognosis. Electrical cardioversion is the first-choice treatment when the arrhythmia is not well-tolerated hemodynamically, while class III antiarrhythmic drugs such as amiodarone should be preferred in the other cases.

[The heart of anorexic adolescents]. / Il cuore nelle adolescenti anoressiche.

BACKGROUND: Anorexia nervosa (AN) is often associated with cardiac changes, such as thinning of the left ventricle (LV), reduction of LV mass, abnormalities of mitral valve function and systolic dysfunction. Some authors have reported QT interval prolongation and sudden death in these patients. METHODS: We studied 23 adolescent females, aged 14.7 +/- 2 years (mean +/- SD), with AN. Serum electrolytes, proteins and albumin were measured in all patients. Electrocardiogram, Doppler-echocardiogram and chest X-rays were also performed on the same day. Eighteen patients were also examined via indirect calorimetry (difference from basal metabolic rate) and 21 underwent dosage of thyroid hormones. RESULTS: The patients, who were of normal height (159 +/- 7.4 cm), were underweight (36 +/- 4.8 kg) and had a body mass index (BMI) of less than 19 (14.2 +/- 1.3). Serum electrolytes, proteins, albumin and chest X-rays were substantially normal in all patients; 74% of them showed reduction of FT3. The calorimetry was reduced (-27.1 +/- 10.6%) with the exception of one patient. Resting heart rate was 58 +/- 12 bpm. We found normal values for PR, QRS, QT (0.41 +/- 0.03 s1/2) and QTc intervals (0.40 +/- 0.03 s1/2) and QT dispersion (40.9 +/- 14.1 ms). Echocardiography showed a reduction in the dimensions of the interventricular septum (52% of patients), LV free wall (61%), left atrium (31%) and LV mass (61%). Fractional shortening was normal in all but one patient. In 61% of cases, there was mild or moderate pericardial effusion that was clinically silent and inversely related to BMI (r = -0.38, p 0.08, ns), to calorimetry (r = -0.56, p < 0.0055), to FT3 (r = -0.53, p < 0.05) and to sodium concentration (r = -0.43, p 0.04). CONCLUSIONS: Teen-agers with AN often show a reduction in LV thickness and mass, as well as clinically silent pericardial effusion that is inversely related to BMI, calorimetry, FT3 and sodium serum concentrations. We did not find any prolongation of QTc interval or of QT dispersion.

Age and stage dependency of P300 latency alterations in non-demented Parkinson's disease patients without therapy.

Acoustic P300 was recorded from Fz, Cz and Pz by means of an 'odd-ball' paradigm in 44 non-demented de novo Parkinson's disease patients (PD) or PD patients under treatment withdrawal, and in 31 age-matched normal subjects, to evaluate whether a P300 latency increase was present in PD patients. The influence of age and disease stage on latency was successively verified by subgrouping PD patients according to different age ('young' and 'old') and disease stage ('early' or 'advanced'). PD patient data were compared to data of normal subjects subgrouped into 'young' and 'old' or, to eliminate the age-dependent shift of latency, this latter was adjusted to 60 years in all the examined subjects. A significant increase of latency has been found in Fz and Cz in the 'old' group of PD patients (n = 23) but not in the 'young' group (n = 21) utilising both methods. Moreover, a significant latency increase was also present in Fz and Cz in the group of 'advanced' PD patients (n = 8), but not in the group of 'early' PD patients (n = 36) utilising age-adjusted measurements. When the 'early' PD patient group was divided into 'young' (n = 20) and 'old' (n = 16), the 'early old' group displayed significantly increased latencies in Fz compared with normal subjects. Abnormal P300 latencies were observed, at least in one electrode, by analysing the raw data, in 5.0% of the 'early young', 43.7% of the 'early old' and up to 62.7% of the 'advanced' patients. Fz represented the site in which abnormal P300 latencies were most often observed. Moreover, in the total group of PD patients, the P300 delay was significant only on the frontal (Fz) site when compared with normal subjects. The reported findings were interpreted as if PD produces a sort of 'accelerated effect of age' on the cognitive functions, presumably produced by a mechanism different from that producing motor impairment since no clear correlation could be detected between P300 latency and motor score. The frontal impairment of P300 is in line with previous neuropsychological findings obtained in these patients. Considering that about 30% of PD patients develop dementia during their disease progression, a border-line or abnormal P300 latency observed at disease onset may represent a predictive marker of this evolution.

Permanent overdrive atrial pacing in the chronic management of recurrent postoperative atrial reentrant tachycardia in patients with complex congenital heart disease.

This study investigated the value of permanent atrial pacing as an adjunct to the current therapy in the chronic management of recurrent postoperative atrial reentrant tachycardia in patients with complex congenital heart disease. We studied the postpacing clinical course in 18 patients with recurrent atrial reentrant tachycardias unresponsive to conventional therapy who had an implanted atrial pacemaker. The pacemaker was programmed at a lower pacing rate 20% faster than the spontaneous mean daily rate previously determined with 24-hour Holter monitoring. Serial Holter recordings and pacemaker programming sessions were subsequently performed trying to maintain a paced atrial rhythm overdriving the spontaneous rhythm as long as possible. Twenty-four hour Holter monitoring documented a prevalent (> 80%) paced rhythm during the daily hours in all patients during the follow-up; all patients, however, required at least once a variation in programmed mode and pacing rate. Antiarrhythmic medications were discontinued after 6 months if the patient remained arrhythmia free while on pacing. Recurrences of atrial reentrant tachycardia occurred in five patients (29%) during the initial 6 months interval after the pacemaker implantation, while late recurrences occurred in only two patients (11%). One patient died suddenly 10 months after the pacemaker implant. At the end of the follow-up, 15 patients (83%) were arrhythmia-free and only 2 of them were still on antiarrhythmic drugs. We conclude that permanent atrial overdrive pacing can be an important tool in the management of patients with atrial reentrant tachycardia following repair of congenital heart disease.

SEPs N30 amplitude in Parkinson's disease and in pharmacologically induced rigidity: relationship with the clinical status.

The frontal N30 wave amplitude of somatosensory evoked potentials (SEPs) has been studied in 41 Parkinson's disease (PD) patients (pts) in a basal condition and compared to that of 30 normal subjects; moreover the N30 amplitude and clinical motor score have been evaluated in a subgroup of 30 PD pts before and during apomorphine infusion and in a second subgroup of 22 PD pts also during levodopa chronic therapy. The data show that N30 amplitude is decreased in PD pts in basal condition and increased following both treatments by a percentage proportional to the clinical improvement Analysis by non parametric correlations showed that the increase is well correlated to the clinical score amelioration induced by apomorphine in the more affected side. The best correlation was to rigidity score amelioration in the group of PD pts in medium stage (Hohen and Yahr stage between 2 and 3), suggesting a relationship between the rigidity and N30 amplitude decrease. Non parkinsonian subjects, treated with low (11 aged normal subjects) and high (eight young psychotic pts) doses of antidopaminergic drugs, were studied. N30 amplitude decreases were only found in the group of eight psychotic pts showing clinical extrapyramidal signs, produced by the high dose of drug administered, but not in the group treated with the lower dose not producing extrapyramidal side effects, although this dose was efficacious on different modalities of evoked potentials. We conclude that N30 amplitude decrease in PD reflects the dopaminergic lack paralleled by clinical symptoms. We propose that N30 amplitude variations by dopaminergic agonists may be useful in the clinical evaluation of dopamine related and non related tone alterations.

Exercise tolerance and behavior of blood pressure in children and adolescents after renal transplant.

OBJECTIVE: The purpose of the study was to evaluate the exercise tolerance and the behaviour of blood pressure during a maximal exercise testing on treadmill for a group of patients with renal transplant carried out at least 6 months earlier. EXPERIMENTAL DESIGN, SETTING AND PATIENTS: In a retrospective study, nineteen patients were examined in our laboratory: 13 boys and 6 girls, mean age 15.8 years (range 10.5-22). INTERVENTIONS: All patients were given a clinical examination, an ECG at rest, a maximal exercise testing on treadmill (Bruce protocol), a mono-2D echo, a lung function test and 24-hour Holter monitoring. The results of the exercise test were compared with those of two control groups of same age and body surface area. RESULTS: The clinical examination of their cardiovascular apparatus gave normal results. The echo revealed anatomical and heart function anomalies related to the original disease. Exercise testing on treadmill showed a reduction in exercise tolerance (p < 0.001) and the maximal heart rate showed a statistically significant difference (p < 0.001) in comparison to control groups. Maximal systolic blood pressure was higher than in patients with same body surface area (p < 0.001) and higher than in peers (p = 0.133). CONCLUSIONS: In view of this hypertensive response, strenuous physical activity should be undertaken with caution and indeed submaximal aerobic activity is more suitable for this population of patients.

Reciprocating supraventricular tachycardia in children: low rate at rest as a major factor related to propensity to syncope during exercise.

Reciprocating supraventricular tachycardia may have several clinical presentations, with symptoms often more severe during exercise or emotional stress. This study shows by using transesophageal atrial pacing, the factors related to syncope during exercise. Between May 1989 and June 1994, transesophageal atrial pacing was performed at rest and during exercise in 75 children aged > 6 years with suspected or documented episodes of paroxysmal supraventricular tachycardia. Reciprocating supraventricular tachycardia could be induced both at rest and during exercise in 22 patients (8 girls, 14 boys; mean age 10.6 +/- 2.7 years, range 7 to 15 years) with ventriculoatrial interval < 70 msec in 11 patients and > 70 msec in 11. At rest, all patients had palpitations caused by the induction of tachycardia. After conversion to sinus rhythm, when tachycardia was induced during exercise, symptoms did not change in 14 patients (group A), whereas symptoms worsened (presyncope) in eight (group B). The statistical analysis showed a significant difference of mean reciprocating supraventricular tachycardia rate at rest between the two groups (group A, 211 +/- 23 beats/min; group B, 173 +/- 33 beats/min; p = 0.0057) and reciprocating supraventricular tachycardia rate variation from rest to exercise (group A, 62 +/- 18 beats/min; group B, 105 +/- 24 beats/min; p = 0.0001). These data suggest that children with low tachycardia rate during normal activities may have syncope more frequently, independently of the tachycardia rate during exercise or emotional stress.

[Transesophageal atrial stimulation in the oral treatment of supraventricular reciprocal paroxysmal tachycardia in infants]. / La stimolazione atriale transesofagea nel trattamento orale della tachicardia parossistica reciprocante sopraventricolare del lattante.

INTRODUCTION: The aim of the study was the evaluation of the usefulness of transesophageal atrial pacing in predicting chronic oral treatment efficacy of symptomatic reciprocating supraventricular tachycardia in infants and in avoiding the risk of very dangerous recurrences at home. METHODS: We studied 13 infants (11 males, 2 females, mean age 43 +/- 31 days) with symptomatic reciprocating supraventricular tachycardia and no structural heart disease. All patients had chronic oral therapy, using the drug effective in acute i.v. somministration. Each patient was discharged when supraventricular tachycardia was not inducible with transesophageal atrial pacing after 5 half-lives of the drug used in chronic oral treatment. All patients, every 6 months, were retested with transesophageal atrial pacing alternatively during chronic oral therapy and after complete wash out. Oral therapy was stopped in each patient when supraventricular tachycardia was not inducible after the wash out. RESULTS: The number of oral treatments tested for each patient were 2 +/- 1 (range 1-5). The number of transesophageal studies performed for each patient were 4 +/- 2 (range 3-7). No patient had symptomatic episodes of supraventricular tachycardia or needed to change therapy during the follow-up. The oral treatment was stopped after the twelfth month of life in 8 patients and after the twenty-fourth in 2 others without recurrences. CONCLUSION: Transesophageal atrial pacing seems to be useful in predicting accurately and rapidly the oral treatment efficacy of supraventricular tachycardia in infants. Our protocol seems to be effective to avoid dangerous recurrences of tachycardia and to decide when we can stop therapy without risk.

P3 components evoked by unilateral and bilateral somatosensory stimulation: normative data for the study of neglect syndrome.

Latency and amplitude of an "odd-ball" somatosensory P3 component evoked either by unilateral or bilateral somatosensory target stimulation, were measured in 15 healthy right-handed subjects (age range 42-79 years) in order to obtain normative data useful for studying the neglect syndrome. The bilateral stimulation protocol was designed to investigate the tactile extinction phenomenon. P3 waves were recorded from nine electrodes. A three-way Anova showed that mean P3 latency on the whole scalp following unilateral stimulations, regardless of side (i.e. right or left stimulations), was significantly longer than that observed after bilateral stimulation. Both "early" and "late" peaks were usually observed in P3 complex. The bilateral modality stimulation showed a more evident "early" peak than the two unilateral stimulations. No significant mean P3 amplitude differences were observed on the whole scalp between bilateral and unilateral stimulations. No significant amplitude differences were observed either for the right or the left hemisphere. The reported latency decrease in the bilateral target stimulation may be a valuable cue for studying possible modifications in patients affected by neglect.

[The life style and physical activity of the child operated on for congenital cardiopathy]. / Abitudini di vita e attività fisica del bambino operato per cardiopatia congenita.

The parents of 151 children operated on for congenital heart disease have answered some questions about the scholastic, extrascholastic and physical activity of their children. Approximately 94% of the children are at the correct school level for their age. Extrascholastic activities of the city children is the same as children living in the country. During their free time 22% of the child population engages in physical activity, whereas 78% of the child population engages in physical activity at school. Among the parents, 61% think the activity of their children is normal, and 27% think it is too active. Our results demonstrate that the children operated on for congenital heart disease have a normal life during scholastic and free time, whereas, the introduction of these children to sport activities is anomalous and insufficient.

[Cycloergometric exercise test in normal children: comparison of an Italian and a North American population]. / La prova da sforzo al cicloergometro in bambini normali: confronto tra una popolazione italiana e nord americana.

The need for a more complete protocol for bicycle ergometer exercise testing in children in our country, induced the Authors to apply the F.W. James protocol to healthy Italian children and then compare the results with a study on a similar american sample population. A total of 102 children, 67 males and 35 females, age range 4.4 - 17 years (mean 10.3 yrs), were examined following the F.W. James protocol. The Authors report the anthropometric and ergometric data obtained, the comparison with James' results and the linear correlation coefficients. Normal reference data were obtained. There were no significant differences between the results obtained from the Italian and American groups, and the correlation coefficients were satisfactory. The results will enable us to benefit from a simple and complete protocol which can be applied to healthy and sick children alike in our country.

[Diagnostic usefulness of Holter monitoring in pediatric fainting and syncope]. / Utilità diagnostica del monitoraggio Holter nelle lipotimie e sincopi in età pediatrica.

The aim of the study was to assess the diagnostic efficacy of ambulatory electrocardiographic monitoring in children with a previous history of fainting and/or syncope. Sixty-one children, from 2 months to 17 years of age, all at the time undergoing different physical examinations because of previous syncopal episodes were examined. All the children had a normal electrocardiogram at rest and all underwent 24 hour electrocardiographic monitoring (Holter). The ECG was normal in 48 patients. Eight children had several dysrhythmias, classified as "borderline" and five children showed a clearly pathological trend. These results are even more significant considering that standard electrocardiogram results are negative. These data underline the diagnostic importance of the dynamic electrocardiogram particularly in cases of very frequently repeated symptoms.

Syntheses and gastric acid antisecretory properties of the H2-receptor antagonist. N-[3-[3-(1-piperidinylmethyl)phenoxy]propyl]thieno[3,4-d]isot hiazol-3-amine 1,1-dioxide and related derivatives.

The synthesis and gastric acid antisecretory properties of several N-substituted thieno[3,4-d]isothiazol-3-amine 1,1-dioxides and analogues are described. Two of the more potent compounds, N-[3-[3-(1-piperidinylmethyl)phenoxy]propyl]thieno[3,4-d] isothiazol-3-amine 1,1-dioxide (6a) and N-[4-[3-(1-piperidinylmethyl)phenoxy]propyl]thieno[3,4-d] isothiazol-3-amine 1,1-dioxide, showed greater potencies as H2-receptor antagonists (in vitro) than ranitidine. They also had potent gastric acid antisecretory activities in vivo, inhibiting basal acid secretion in the rat, histamine-stimulated acid secretion in the dog, and food-stimulated acid secretion in the dog. These were selected for further pharmacological evaluation.

2-Oxo-1,8-naphthyridine-3-carboxylic acid derivatives with potent gastric antisecretory properties.

The syntheses of 2-oxo-1,8-naphthyridine-3-carboxylic acid derivatives having potent gastric antisecretory properties in the pyloric-ligated (Shay) rat model are described. Two of the more potent compounds tested that were selected for more detailed dose-response evaluation were 4-amino-1-ethyl-1,2-dihydro-2-oxonaphthyridine-3-carboxylic acid ethyl ester (35) and 1-ethyl-1,2-dihydro-7-methyl-4-(4-methyl-1-piperazinyl)-2- oxo-1,8-naphthyridine-3-carboxylic acid ethyl ester (77). These compounds lowered total acid output in the rat in a dose-related fashion. Both compounds were more potent than cimetidine when tested in the rat. Both 35 and 77 showed inhibitory activity in food-stimulated acid secretion in the Pavlov-pouch, conscious dog. The mechanism of action for this series is not known. Details of structure-activity relationships are described.