High prevalence of central hypothyroidism in adult patients with ß-thalassemia major.

The commonest form of thyroid dysfunction seen in subjects with TM is primary hypothyroidism due to abnormalities of the thyroid gland. Central hypothyroidism (CH) has been reported as an uncommon clinical entity in TM patients although the anterior pituitary gland is particularly sensitive to free radical oxidative stresses. Diagnosis is usually made on a biochemical basis showing low circulating concentrations of thyroid hormone associated with an inappropriately low TSH levels. The diagnosis is not clinically obvious and a basal normal TSH level does not exclude the diagnosis of CH. Therefore, it is important that clinicians accurately interpret thyroid function tests. In TM patients, CH prevalence differs at different ages is unknown and it is not easy to diagnose because most of the symptoms of symptoms of CH are non specific and are frequently attributed to anaemia or other associated complications . We performed a cross-sectional analysis on a large database using the clinical records of our TM patients to explore the prevalence of CH in prepubertal (<11 years: 25 patients; 13 males) peripubertal (between 11 and 16 years: 9 patients; 3 males), and pubertal TM subjects (>16 years: 305 patients; 164 males). Central hypothyroidism was present in 26 (7,6%) TM patients. Their mean age was 29.9 ± 8.4 years, 14 (53.8%) were males and 12 (46.1%) were females. The prevalence of CH was 6% in patients with a chronological age below 21 years and 7.9% in those above 21 years. Clinicians should be alert for the diagnosis of CH through accurate interpretation of thyroid function tests. We recommend L-thyroxine therapy if the level of FT4 is consistently low provided that the patient has normal cortisol levels.

Gamma ray dosimetry and mating capacity studies in the laboratory on Aedes albopictus males.

In Italy, Aedes albopictus Skuse is currently recognized as the most dangerous mosquito, and as currently applied conventional control methods gave unsatisfactory results, we are developing alternative strategies such as the sterile insect technique. To find the optimal sterilizing dose, male pupae were exposed to different doses of gamma rays in the range 20-80 Gy, generated by a Cesium-137 source. The effects of male pupal age at irradiation and gamma ray dose on adult male emergence, sterility level, longevity, and mating capacity were evaluated, and dose-response curves of residual fertility were calculated. Radiation tests were also performed on female pupae to observe their reproductive capacity in case of accidental release. Results confirmed that the age at which the male pupa is irradiated is an important factor that affects the longevity of the adult, whereas the effect of age on the induced sterility level is less pronounced. When male pupae older than 30 h were irradiated, the longevity of the adults was not affected by doses up to 40 Gy. The 40-Gy dose appeared sufficient to induce high level of sterility (>99%) at any male pupal age for all the strains tested. The duration of coupling and the number of mated females per male appeared to be affected by the radiation received by male pupae only at doses higher than 40 Gy. The female pupae were more sensitive to radiation than male pupae, with strong reduction in fecundity and fertility at 20 Gy and complete suppression of oviposition at higher doses.

Direct and autonomically mediated effects of oral flecainide.

This study was undertaken to determine if oral flecainide exerts autonomically mediated actions in addition to its direct depressant effect. Electrophysiologic studies were performed twice in each of 15 patients (mean age 59 years) with normal resting and intrinsic heart rate and normal A-H interval. In the first study, the variables of sinus node and atrioventricular node were evaluated both in the basal state and after autonomic blockade (propranolol 0.2 and atropine 0.04 mg/kg). Oral flecainide was administered for 4 to 5 days (200 to 250 mg daily) and the study was then repeated using the same methods. From comparison of data obtained in the 2 studies in the basal state, the overall effect of flecainide was evaluated and by comparing those obtained after autonomic blockade, the direct action of the drug was assessed. The overall effect of flecainide on sinus node was slight; sinus cycle length, corrected sinus node recovery time and sinoatrial conduction time did not change significantly after the drug. In contrast, after autonomic blockade the variables of sinosal automaticity were increased significantly (p less than 0.01). Flecainide significantly prolonged the atrioventricular node variables both in the basal state and after autonomic blockade (p less than 0.01), but the degree of increase was more marked after autonomic blockade (p less than 0.05). These data show dual effects of oral flecainide: a direct depressant action and an autonomically mediated opposing action, likely of vagolytic type.

Validation of severity scoring systems SAPS II and APACHE II in a single-center population.

OBJECTIVE: To validate two severity scoring systems, the Simplified Acute Physiology Score (SAPS II) and Acute Physiology and Chronic Health Evaluation (APACHE II), in a single-center ICU population. DESIGN AND SETTING: Prospective data collection in a two four-bed multidisciplinary ICUs of a teaching hospital. PATIENTS AND METHODS: Data were collected in ICU over 4 years on 1,721 consecutively admitted patients (aged 18 years or older, no transferrals, ICU stay at least 24 h) regarding SAPS II, APACHE II, predicted hospital mortality, and survival upon hospital discharge. RESULTS: At the predicted risk of 0.5, sensitivity was 39.4 % for SAPS II and 31.6 % for APACHE II, specificity 95.6 % and 97.2 %, and correct classification rate 85.6 % and 85.5 %, respectively. The area under the ROC curve was higher than 0.8 for both models. The goodness-of-fit statistic showed no significant difference between observed and predicted hospital mortality (H = 7.62 for SAPS II, H = 3.87 for APACHE II; and C = 9.32 and C = 5.05, respectively). Observed hospital mortality of patients with risk of death higher than 60 % was overpredicted by SAPS II and underpredicted by APACHE II. The observed hospital mortality was significantly higher than that predicted by the models in medical patients and in those admitted from the ward. CONCLUSIONS: This study validates both SAPS II and APACHE II scores in an ICU population comprised mainly of surgical patients. The type of ICU admission and the location in the hospital before ICU admission influence the predictive ability of the models.

A method for evaluating different modes of action of an antiarrhythmic drug in man. The effects of propafenone on sinus nodal functions.

In vitro experiments have shown that the antiarrhythmic effects of propafenone are due to a direct depressant action and to a beta-blocking activity. In this study a method was used to evaluate the direct effect and the autonomically mediated actions of an antiarrhythmic agent in a clinical setting. An electrophysiological study was performed twice, at an interval of 24 hr, in 17 patients (age: 52 +/- 17 years) with normal resting and intrinsic heart rate. In the first study the overall effect of intravenous propafenone (1.5-2 mg/kg) was evaluated by comparing the sinus node parameters obtained during the basal state and after drug administration. In the second study the direct depressant effect of the drug was evaluated by comparing the electrophysiological variables obtained following autonomic blockade (propranolol 0.2 mg/kg and atropine 0.04 mg/kg) and after propafenone. In the first study there was no significant change in the sinus cycle length and corrected sinus node recovery time and only a small (9.1%) increase in sinuatrial conduction time, whereas in the second study these variables increased significantly. The degree of increase in sinus cycle length and corrected sinus node recovery time was significantly higher in the second study than in the first one. These data suggest that: (1) propafenone has direct depressant effect on sinus automaticity but this effect is counteracted by autonomically mediated actions (most likely of vagolytic type); (2) the beta-blocking effect of the drug demonstrated in isolated atria is not seen in a clinical setting.

Reproducibility of electrophysiological parameters of sinus node following autonomic blockade.

We investigated the reproducibility of sinus node cycle length (SCL), corrected sinus node recovery time (CSRT) and sino-atrial conduction time (SACT) during the control state and following autonomic blockade in 25 patients (mean age: 56.9 +/- 13.8 years). Autonomic blockade was induced by i.v. administration of propranolol (0.2 mg/kg) and atropine (0.04 mg/kg). The electrophysiological study was repeated after 24 hr and the results were compared. The patients were divided into two groups: Group 1 (15) with normal and Group 2 (10) with abnormal intrinsic sinus node function. Following autonomic blockade in Group 1 the daily variations in SCL, CSRT and SACT were very slight whereas in Group 2 there was far greater variability in these parameters. However, in the latter group there were no patients who changed their status from prolonged to normal intrinsic CSRT on the second study, whereas SACT changed its status in 2 patients. In Group 1 the daily variations in sinus node parameters were much slighter following autonomic blockade than during the control state. In Group 2 the variations were very similar during control and following autonomic blockade. These data suggest that: (1) following autonomic blockade the reproducibility of sinus node parameters is very good in Group 1, whereas in Group 2 several patients show marked daily variations in sinus node parameters; (2) following autonomic blockade the sinus node electrophysiological parameters are meaningful in diagnosing an involvement of intrinsic sinus node function; and (3) in patients with abnormal sinus node parameters during control state, but with normal intrinsic sinus node function, the daily variations are mainly due to change in autonomic tone, whereas when the intrinsic sinus node function is abnormal, the day to day variations during control state appear due predominantly to intrinsic sinus node abnormalities.

Blood prolactin levels: influence of age, menstrual cycle and oral contraceptives.

The relationships between the serum levels of estradiol, progesterone and prolactin have been analysed in normal women in relation to age, to menstrual cycle, and in oral contraceptives users. We have been able to detect significant differences between the prolactinemia values during the cycle in different age groups as well as following oral contraceptives. A word of caution is presented for the evaluation of the prolactin blood level which should always be related to the physiological phase of the cycle and to the age of the subjects.

Quality control of 99Mo/99Tcm generators: results of a survey of the Radiopharmacy Working Group of the Italian Association of Nuclear Medicine (AIMN).

A multicentre survey of the quality control of 99Tcm generators has been completed: 245 generators from seven different commercial sources were tested over a period of 2 years. The results indicate that the mean pH of the eluates was 5.8 +/- 0.6; the aluminium contents were typically < 10 ppm; the radiochemical purity was 99.8 +/- 0.4% and the median 99Mo content was 3.8 x 10(-4) percent. The elution profiles gave a volume of 1.9 ml to obtain 50% of the total eluted activity and of 4.9 ml to obtain 95%. Other radionuclide impurities and heavy metal breakthrough were evaluated by graphite furnace absorption spectrometry and inductively coupled plasma mass spectrometry. National guidelines for the standardization of radiopharmacy procedures are currently being compiled.

A survey of radiation dose and image quality in mammography: an ongoing program in Italy.

A program for mammography optimization in individual x-ray units, named Dose and Quality in Mammography (DQM), is now underway in Italy. The project has three stages: measurement of the parameters that affect dose and image quality by means of devices that are practical to use (specifically designed for the purpose), analysis of data to evaluate dose and image quality and suggestion of possible improvements to each unit operator. Instruments and methods employed in our survey are described. Our results, like those of the American survey (Je78) Breast Exposure: Nationwide Trends (BENT), show widespread variations of exposure, half value layer (HVL), optical density, dose and resolution. Facilities using the same type of x-ray apparatus (Mo target-Mo filter) and film-screen combinations present very different exposure values, ranging from 1.6 X 10(-4) to 27.6 X 10(-4) C kg-1. The causes of these variations--ascribable to the individual units, radiologist preferences, processing condition, kVp indicator and timer accuracy--are being explored.

A practical method for the estimation of therapeutic activity in the treatment of Graves' hyperthyroidism.

AIM: To test the efficacy of a practical method which allows the calculation of personalized activity in Graves' disease. METHODS: The method is based on International Commission of Radiological Protection (ICRP) 53 data. The model allows the prediction of the activity administered in order to release 300 Gy to the thyroid, once its iodine uptake and mass are known. We applied it to 289 patients investigated by clinical examination, biochemical assessment and neck ultrasonography. The method was applied considering the thyroid 131I uptake and the ultrasound mass. The patients were followed by check of TSH, FT3, FT4 and clinical examination. Finally, we evaluated the difference between our dosimetric method and the hypothetic administration of a fix amount of 131I (185, 370 and 600 Mbq respectively) in term of adsorbed dose. RESULTS: The average activity administered was 403.3+92.5 MBq with an average dose released to thyroid of 304.9+24.8 Gy. From a statistical point of view the administration of standard activities (185 and 600 MBq) would represent respectively a wrong estimate of the optimal dose (meanly 140.8+44.7 Gy and 473.6+142.6 Gy respectively). The administration of a standard activity (370 MBq) would release a dose close to that prescribed (291.2 Gy) with a standard deviation (86.9 Gy), which is considerably higher than the one obtained with the dosimetric model (24.8 Gy). Twenty four months after radioiodine treatment, 57.8% of patients presented hypothyroidism, 23.2% euthyroidism and 19% of hyperthyroidism. The overall therapeutic efficiency was of 81%. CONCLUSION: The dosimetric method based on IRCP 53 data, is effective in controlling Graves' hyperthyroidism. Advantages in adopting this method are: dose optimization to patient, easy implementation in the clinical practice, low budget impact.

[A program devoted to dose and quality in mammography (DQM)]. / Programma finalizzato dose e qualità in mammografia (DQM).

Radiological units present different exposure values, (even by a factor 100), for the same radiological examination unless special programs are performed in order to optimize the examinations and to reduce variations. The program named DQM, mentioned in the Circular n. 62 of the Ministry of Health, is planned for mammographic optimization. The steps of the programme are: a) collection of the working parameters in each unit, b) dose and image quality evaluation, c) communication of the results and suggestion for corrective actions. The practical aspects of the program and the results of measurements in 65 mammographic units are presented and discussed. The importance of the Quality Assurance, performed by radiologists and physicists is underlined.

Bedside evaluation of sinus bradycardia: usefulness of atropine test in discriminating organic from autonomic involvement of sinus automaticity.

In 55 patients with persistent sinus bradycardia who underwent an electrophysiologic study of sinus node, both in the basal state and after autonomic blockade (propranolol, 0.2 mg/kg, and atropine, 0.04 mg/kg), an atropine test (0.02 mg/kg) was performed the following day. The 49 patients in whom sinus rate could be evaluated after atropine were subdivided into two groups--group I, 24 patients (age: 54 +/- 13 years) with normal intrinsic sinus automaticity (normal intrinsic heart rate and intrinsic corrected sinus node recovery time) and group II, 25 patients (age: 62 +/- 9 years) with abnormal intrinsic sinus automaticity. In group I, atropine increased sinus rate from 53.7 +/- 4 to 87.9 +/- 17 bpm (delta %: 65.5 +/- 33) and in group II from 51.6 +/- 5 to 73.9 +/- 14 bpm (delta %: 43.1 +/- 26). The discriminant threshold of sinus rate after atropine and its percent increase, obtained by discriminant analysis, was 80 bpm and +52%, respectively, with a misleading classification of 32% and 36%, respectively. The overall predictive accuracy of sinus rate after atropine was higher than the percent change in sinus rate (73% and 65%, respectively). These data evidence that the atropine test is not very helpful in discriminating between an organic and an autonomic involvement of sinus automaticity in patients with sinus bradycardia.

[Usefulness of transesophageal stimulation in the evaluation of sinus node function in patients with sick sinus syndrome]. / Utilità della stimolazione transesofagea nella valutazione della funzionalità sinusale nei pazienti con sick sinus syndrome.

The purpose of this study was to find out whether transesophageal pacing could be utilized for assessment of sinus node function, besides Wenckebach point, in patients with sick sinus syndrome. In 17 patients with sino-atrial disease (group I) we compared the results of sinus node tests obtained both in the basal state and after pharmacological autonomic blockade by endocavitary stimulation and 24 hours later, by transesophageal pacing. In another group of 17 patients with sino-atrial disease (control group) we compared the results obtained from two endocavitary studies. In group I, sinus cycle length and corrected sinus recovery time did not show significant differences between the two studies either the basal state or after autonomic blockade, whereas sino-atrial conduction time was more prolonged during esophageal pacing (P less than 0.01). In the control group, sinus node measures did not show significant differences between the two studies. In group I, the following coefficients of correlation were obtained: A) in the basal state sinus cycle length, r = 0.65, corrected sinus recovery time, r = 0.57, sinoatrial conduction time, r = 0.52; B) after autonomic blockade sinus cycle length, r = 0.95, corrected sinus recovery time, r = 0.62 and sino-atrial conduction time, r = 0.53. In the basal state, the correlation for sinus cycle length and corrected sinus recovery time between the two studies was lower in the "study group" than in the "control group" (P less than 0.05). However, after autonomic blockade the correlation for sinus node measures did not show any significant differences between the two groups of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability of transesophageal pacing in the assessment of sinus node function in patients with sick sinus syndrome.

The purpose of this study was to find out whether transesophageal pacing could be utilized for assessment of sinus node function in patients with sick sinus syndrome (SSS). In 17 patients with SSS (study group) we compared the results of sinus node tests obtained both in the basal state and after pharmacological autonomic blockade by endocavitary stimulation and, 24 hours later, by transesophageal pacing. In another group of 17 patients with SSS (control group), we compared the results obtained by two endocavitary studies. In "study group", sinus cycle length (SCL) and corrected sinus node recovery time (CSRT) did not show significant differences between the two studies both in the basal state and after autonomic blockade, whereas sinoatrial conduction time (SACT) was more prolonged during esophageal pacing (P less than 0.01). In "control group", sinus node measures did not show significant differences between the two studies. In the "study group," the following coefficients of correlation were obtained in the basal state; SCL, r = 0.65, CSRT, r = 0.57, SACT, r = 0.52 and after autonomic blockade: SCL, r = 0.95, CSRT, r = 0.62 and SACT, r = 0.53. In the basal state, the correlation for SCL and CSRT between the two studies was lower in the "study group" than in the "control group" (P less than 0.05), whereas after autonomic blockade the correlation for sinus node measures did not show significant differences between the two groups of patients. These data suggest that transesophageal study influences the autonomic tone regulating the sinus node; however, it is not responsible for important variations in sinus node measures.(ABSTRACT TRUNCATED AT 250 WORDS)

Autosomal dominant microcephaly without mental retardation.

We describe six Italian families affected by microcephaly with an apparently autosomal mode of inheritance (total number of microcephalic children and adults, 21). All microcephalic subjects were of normal height, with the exception of one. The head volume was measured directly in at least one adult microcephalic member from five of the six families, and lower values were obtained in these subjects than in control subjects. Psychometric tests were performed on seven children and five adults among the microcephalic subjects. Normal values were found for all but one of the subjects. In the selected families microcephaly seems to be inherited in an autosomal dominant manner. Because some families showing autosomal dominant microcephaly have normal intelligence, psychometric evaluation of microcephalic children and their microcephalic relatives is important for genetic counseling.

[Method for differentiating in humans the direct effects of anti-arrhythmic drugs from those mediated by the autonomic nervous system. Effects of quinidine and propafenone]. / Metodo per differenziare nell'uomo gli effetti diretti dei farmaci antiaritmici da quelli mediati dal sistema neurovegetativo. Effetti della chinidina e del propafenone.

We have set up a method which investigates the different modes of action of an antiarrhythmic drug in man, in particular the direct effects of the drug and those mediated by the autonomic nervous system (ANS). The electrophysiological study (ES) is performed twice in each patient. In the first study the parameters of sinus and A-V nodal functions are evaluated both in the basal state and after pharmacological autonomic blockade (AB) (propranolol 0.2 mg/kg and atropine 0.04 mg/kg). Subsequently, the antiarrhythmic drug is administered per os until a steady-state has been achieved and the ES is then repeated with the same method. By comparing the data obtained in the two studies in the basal state, before and after drug administration, we can evaluate the overall effect, and by comparing those obtained after pharmacological AB we can assess the direct action of the drug. From the comparison of the percentage changes in the examined parameters in the basal state and following AB we can evaluate whether the drug, besides having a possible direct action, also has another one which is mediated by the ANS. This method can be adapted to the way of administration and to the pharmacodynamics of the drug. If the drug does not induce important hemodynamic effect, it can be studied also after intravenous administration. In this case during the first study we can evaluate the overall effect and during the second study the direct effect. The electrophysiological parameters are then compared with the above mentioned method.(ABSTRACT TRUNCATED AT 250 WORDS)

Poor R wave progression in pure mitral stenosis. Correlation with hemodynamic data.

Poor R wave progression in the right precordial leads has frequently been reported in patients with pure mitral stenosis, but has never been investigated from clinical and hemodynamic points of view. In this work the clinical, electrocardiographic and hemodynamic data of 19 patients (mean age: 49 +/- 8.6 years), with pure mitral stenosis and poor R wave progression (study group) were compared with those of 19 subjects with pure mitral stenosis and normal R wave progression (control group). The age, sex distribution and duration of mitral valve disease were similar in the two groups; also clinical status, i.e. the distribution in the functional classes (NYHA), was similar in the two groups. Mitral valve area was similar in the two groups (1.3 +/- 0.5 vs 1.1 +/- 0.3 cm2), whereas wedge pressure, mean pulmonary artery pressure, systolic and diastolic right ventricle pressures and total pulmonary resistances showed significant lower values in patients with poor R wave progression compared to those with normal R wave progression (P less than 0.05). The hemodynamic variables of left ventricle and the cardiac index were similar in the two groups. In study group patients there was higher prevalence of vertical axis (P less than 0.05). These data indicate that in pure mitral stenosis, clinical status is similar in patients with poor R wave progression and in those with normal R wave progression, whereas in the former there is slighter hemodynamic involvement of the right ventricle.

[Determination of cerebral blood flow using non-diffusible tracers]. / Determinazione del flusso ematico cerebrale con traccianti non diffusibili.

A program for the evaluation of cerebral blood flow based on the analysis of the time activity curves is presented. The method is based on the Meier and Zierler formula, applying the partition coefficents suggested by Lassen et al. for the corrections deriving from the use of non-diffusible indicators (99Tcm-DTPA). Particular attention is given to the smoothing of the time-activity curve (using Legendre's polynomials) and to the correction function for reflux. The computation procedures and their validity is discussed.