Morphological analysis of dendritic spine development in primary cultures of hippocampal neurons

We monitored developmental alterations in the morphology of dendritic spines in primary cultures of hippocampal neurons using confocal laser scanning microscopy (CLSM) and the fluorescent marker Dil. Dissociated rat hippocampal neurons were plated on polylysine-coated glass cover slips and grown in culture for 1-4 weeks. Fixed cultures were stained with Dil and visualized with the CLSM. Spine density, spine length, and diameters of spine heads and necks were measured. Some cultures were immunostained for synaptophysin and others prepared for EM analysis. In the 1-3 week cultures, 92-95% of the neurons contained spiny dendrites. Two subpopulations of spine morphologies were distinguished. At 1 week in culture, "headless" spines constituted 50% of the spine population and were equal in length to the spines with heads. At 2, 3, and 4 weeks in culture headless spines constituted a progressively smaller fraction of the population and were, on average, shorter than spines with heads. Spines with heads had narrower necks than headless spines. At 3 weeks in culture, spines were associated with synaptophysin-immunoreactive labeling, resembling synaptic terminals. At 4 weeks in culture, only 70% of the Dil-filled cells had spiny dendrites, and the density of spines decreased. Ultrastructurally, the majority of dendritic spine-like structures at 1 week resembled long filopodia without synaptic contacts. The majority of axospinous synapses were on short "stubby" spines. At 3 weeks in culture, the spines were characteristic of those seen in vivo. They contained no microtubules or polyribosomes, were filled with a characteristic, filamentous material, and formed asymmetric synapses. These studies provide the basis for further analysis of the rules governing the formation, development, and plasticity of dendritic spines under controlled, in vitro conditions.

Immediate early genes and brain DNA remodeling in the Naples high- and low-excitability rat lines following exposure to a spatial novelty

The aim of these studies was to map the neural consequences of exposure to a spatial novelty on the expression of immediate gene (IEG) and on unscheduled brain DNA synthesis (UBDS) in two genetic models of altered activity and hippocampal functions, i.e., the Naples High- (NHE) and Low-excitability (NLE) rats. Adult male rats of NLE and NHE lines, and of a random-bred stock (NRB) were tested in a Làt-maze, and corner crossings, rearings, and fecal boli were counted during two 10-min tests 24 h apart. For IEG expression, rats were exposed to a Làt-maze with nonexposed or repeatedly exposed rats used as controls, and were sacrificed at different time intervals thereafter. For UBDS, rats were sacrificed immediately after the first or the second exposure o a Làt-maze. IEG expression was measured by immunocytochemistry for the FOS and JUN proteins. NRB rats exposed for the first time to the maze showed extensive FOS and JUN positive cells in the reticular formation, the granular and pyramidal neurons of hippocampus, the amygdaloid nuclei, all layers of somatosensory cortex, and the granule cells of the cerebellar cortex. The positivity, stronger in rats exposed for the first time, was present between 2 and 6 h and was prevented by the NMDA receptor antagonist CPP (5 mg/kg). The positivity was very low in NHE rats, and it was stronger in NLE compared to NRB rats. UBDS was measured in ex vivo homogenates of brain areas by the incorporation into DNA of 3H-[methyl]-thymidine given intraventricularly 15 min before test trial 1 or 2 (pulse of 0.5 h).(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide and long-term habituation to novelty in the rat

The role of nitric oxide in learning and memory processes has been tested in the albino rat by a histochemical and a behavioral study, following behavioral habituation to spatial novelty. Histochemically, the neural consequences of behavioral testing were mapped in the brain by staining for NADPH-d, known to be a NOS, whereas behaviorally the formation of LTH has been interfered with by posttrial NOS-inhibition. In the histochemical study, adult male Sprague-Dawley rats were tested in a Làt-maze and sacrificed at different time intervals thereafter. Handled unexposed rats served as controls. The brains were perfused with aldheide and processed for NADPH-d staining. In unexposed control rats the basal expression of NADPH-d was low and scattered. It pertained to few cells in the neostriatum, cerebral cortex, and CA1 hippocampal regions. In contrast, rats that had been exposed for the first time to the maze (spatial novelty) showed NADPH-d activity in the dorsal hippocampus (granule cells, few hilar neurons, and some CA1 pyramidal cells), the caudate-putamen complex, the cerebellum, and in all layers of somatosensory cortex. The positivity was not due to activity per se, since immediately after exposure it was not different from baseline. In contrast, it was present by 2 h and decreased significantly 24 h later. In addition, a strong neuronal discharge induced by the convulsant pentylentetrazol did not induce NADPH-d 2 h afterwards. The staining was prevented by pretreatment with the NMDA receptor antagonist CPP (5 mg/kg) or with the NOS inhibitor L-NOARG (10 mg/kg). In the behavioral study, rats were given an intraperitoneal injection of 1-10 mg/kg (L-NOARG) or vehicle immediately following exposure to a Làt-maze. The highest dose used (10 mg/kg) disrupted habituation of the vertical component only, known to be mainly of emotional meaning. Conversely, both doses disrupted emotional habituation based on defecation scores. The data indicate that the formation of LTH to novelty triggers a cascade of neurochemical events also involving NOS neurons. Further, the widespread induction of NADPH-d by exposure to novelty suggests that spatial and emotional information processing activate neural networks across different organizational levels of the CNS.

Spontaneous closure of inlet ventricular septal defect in an infant with Down's syndrome and aortic coarctation

Ventricular septal defect (VSD) is considered one of the most common congenital heart diseases in patients with Down's syndrome. It is well known that some VSDs show a tendency to diminish in size and to close. To our knowledge, in patients with Down's syndrome spontaneous closure of a perimembranous inlet VSD has not been described before. The prevalence of some cardiac malformations and the rarity of others have been reported in patients with Down's syndrome. Left ventricular outflow tract obstruction rarely occurs in patients with Down's syndrome. A case of Down's syndrome with coarctation of the aorta, patent ductus arteriosus, and perimembranous inlet VSD that spontaneously closed by formation of aneurysm of the membranous septum is reported.

Distributed changes in c-Fos and c-Jun immunoreactivity in the rat brain associated with arousal and habituation to novelty

The effects of exposure to spatial novelty on expression of the immediate early gene (IEG) products c-Fos and c-Jun were mapped in the rat brain by immunohistochemistry. Adult male Sprague-Dawley rats were tested for 10 min in a Làt-maze, and corner-crossings, rearings, and fecal boli were recorded. Rats were sacrificed at different time intervals after exposure to the maze (0.5, 2, 6, or 24 h). Unexposed rats or rats repeatedly exposed for 3 days at 24 h interval served as controls. Nonperfused brains were processed for immunocytochemistry for c-Fos and c-Jun on adjacent slices using the avidin-biotin method and diaminobenzidine as chromogen. In unexposed control rats the constitutive expression of the two IEGs products was low and scattered. In contrast, rats that had been exposed for the first time to the maze (spatial novelty) showed an extensive c-Fos- and c-Jun-like immunoreactivity in the reticular formation, the caudate-putamen complex, the hippocampus (granular and pyramidal neurons), the cerebellum (granular neurons), and all layers of somatosensory cortex. The positivity was stronger in rats exposed for the first time to the box than in repeatedly exposed or unexposed control rats. A maximal IEG expression was found in animals with postexposure survival times of 2 and 6 h. IEG expression in repeatedly exposed rats was still above baseline expression of unexposed rats but still lower than that of rats having been exposed only once to the maze.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioimmunodetection of colorectal cancer metastases with 131I-labeled monoclonal antibody B72.3: a pilot study to determine efficacy of detection and pharmacokinetics

We performed radioimmunoscintigraphy (RIS) and/or pharmacokinetic (PCK) studies in 12 patients with primary or metastatic colorectal carcinoma, utilizing an intravenous administration of 1-4 mCi (1 mg) of 131I-B72.3 monoclonal antibody. Metastatic lesions were correctly identified in 4/8 patients by RIS. Two patients with small lesions (> 2 cm diameter) had a false-negative RIS scan. Two patients had a true-negative RIS scan. Optimal images were obtained at 1 week postinjection. PCK studies showed that the plasma clearance of 131I-B72.3 was biexponential with an alpha-phase half-life ranging from 0.5 to 7.1 hr and a beta-phase half-life ranging from 47.5 to 85.3 hr. Systemic and renal clearance data indicated that 131I-B72.3 was cleared very slowly and almost entirely by deiodination. This pilot study was conducted to gain an understanding of the pharmacokinetics of this radiolabeled antibody. On the basis of these data, we are now studying second-generation antibodies as part of our long-range objectives to incorporate them in early detection and treatment protocols.

Autoimmune mechanisms in thromboangiitis obliterans (Buerger's disease): the role of tobacco antigen and the major histocompatibility complex

This study is a continuation of our previous work that showed that patients with thromboangiitis obliterans (TAO; Buerger's disease) demonstrate a cell-mediated immune response to human artery type-specific collagens. To investigate the role of cigarette smoking in patients with TAO, cellular and humoral sensitivity was tested to a tobacco glycoprotein (TGP) antigen in 13 patients with Buerger's disease, 16 healthy smokers, and 12 nonsmoking healthy young male subjects. In this study, patients with Buerger's disease and healthy smokers had the same rate of cellular response to TGP, whereas nonsmokers did not respond. All three groups had a 30% to 40% measurable antibody response to TGP. If TGP has an immunologic role in the pathogenesis of TAO, an additional factor (or factors) may be operative. A specific genetic makeup may be one such factor, although at this stage other pathogenic mechanisms cannot be ruled out. Eleven patients with Buerger's disease and two control groups of 10 young healthy smoking male subjects and 12 young nonsmokers underwent histocompatibility leukocyte antigen (HLA) typing. Patients with Buerger's disease had a statistically significantly higher frequency of HLA-DR4 and a significantly lower frequency of the HLA-DRW6 antigen than had both control groups. Because similar findings have been reported in other autoimmune diseases, this observation may serve as further evidence that an autoimmune mechanism is involved in Buerger's disease.

[Right atrial isomerism with pulmonary atresia: the angiocardiographic characteristics and pulmonary circulatory patterns]

The patterns of pulmonary circulation were assessed by angiography in a series of 24 patients with right atrial isomerism (asplenia syndrome) and pulmonary atresia. Mean age at catheterization was 21.5 days (range 1 day-11 months). The pulmonary arteries were confluent in 22 cases (91.7%). Eighteen patients (75%) had ductus-dependent pulmonary circulation in presence of confluent pulmonary arteries, similar to cases of pulmonary atresia combined with complex congenital heart disease. The ductus appeared in continuity with the aortic arch, shaping an acute angle with the descending aorta, as in cases of pulmonary atresia with ventricular septal defect. A bilateral ductus was present in 5 cases (20.8%), 3 with confluent and 2 with nonconfluent pulmonary arteries. One patient presented multiple systemic collaterals to the lungs. All the other patients had normal arborization of the pulmonary arteries. Seven patients presented an obstructed total anomalous pulmonary venous connection: 4 in inferior vena cava and 3 in superior vena cava. These anatomical observations provide useful information for the surgical palliation of these anomalies and, probably, warrant pre-operative angiographic evaluation in all the patients with right atrial isomerism.

Estrogen induces c-fos expression specifically in the luminal and glandular epithelia of adult rat uterus

It was previously shown that injection of 17 beta-estradiol into adult ovariectomized rats induces a rapid and transient increase of c-fos gene transcription in the uterus. Immunohistochemical analysis now shows that estrogen activates c-fos specifically in the luminal and glandular epithelial cells of the endometrium, which are the only uterine cells responding to the hormone with DNA synthesis and cell proliferation, and not in estrogen receptor positive stromal and myometrial cells. This finding suggests that c-fos is involved in the mechanism of estrogen regulation of uterine epithelial cell proliferation and, furthermore, that the c-fos activation by estrogen is cell type dependent.

[Interventricular muscular defect in the atrioventricular canal]

The muscular ventricular septal defect associated with the atrioventricular canal is a malformation which has not yet been extensively studied. Between June 1982 and December 1989, 151 patients with atrioventricular canal underwent echocardiography and angiocardiography in our Department. Of these 95 (62.9%) had a complete form and 56 (37.1%) a partial. Among the 151 patients, 81 (53.6%) presented Down syndrome. We found 5 muscular ventricular septal defects in 4 patients; in 3 cases there was a single defect and in one case two defects. These defects were midmuscular in all patients and one patient also presented an apical defect. All 4 patients with muscular ventricular septal defect presented a complete atrioventricular canal and aortic coarctation; 3 out of 4 patients had a hypoplastic left ventricle with absence of Down syndrome. The muscular ventricular septal defect is a malformation which is rarely associated with atrioventricular canal (4/151 = 2.6%). In our experience, it was always associated with a complete form with aortic coarctation and was very rare in Down syndrome patients (1/81 = 1.2%). These findings may represent a peculiar association of anomalies which may be caused by fetal hemodynamic mechanisms.

Acute effects of nisoldipine, propranolol, and their combination in patients with chronic stable angina: a double-blind, randomized, cross-over, placebo-controlled study

We studied the short-term effects of oral administration of nisoldipine (10 mg) and propranolol (80 mg) alone and in combination in 14 patients with chronic exertional angina pectoris in a double-blind, randomized, cross-over study. The 14 patients (13 men and 1 woman, mean age 56 +/- 7 years) performed symptoms-limited bicycle exercise stress test 3 h after placebo or active substance administration. Maximal work load, exercise duration, and time to 1-mm ST segment depression were significantly increased and ST depression at peak exercise was significantly decreased by drugs alone and in combination. Propranolol and nisoldipine alone improved exercise duration similarly and as well as the combination; however, a different response to the three pharmacologic interventions was found in patients treated with single drugs. The improvement in exercise tolerance was associated with rate-pressure product values at peak exercise, unchanged after nisoldipine and significantly reduced after both propranolol alone and in combination. After placebo, all patients had exercise-induced angina, in 9, 8, and 4 patients after nisoldipine, propranolol, and the combination of the two drugs, respectively. Nisoldipine is effective in the treatment of effort angina and its combination with propranolol may be useful and superior in patients who show poor response to monotherapy.

[Hypothermia treatment of junctional ectopic tachycardia after surgical repair of congenital heart defects]

Junctional ectopic tachycardia after surgical repair of congenital heart defects is associated with high mortality. Usually, it is transitory and resolves spontaneously, but a long period with very fast heart rate and without atrio-ventricular synchrony contraction may cause low cardiac output. Treatment with common anti-arrhythmic drugs is often uneffective both in restoring sinus rhythm and in reducing heart rate. Since hypothermia is known to decrease cardiac automaticity, two infants, aged 4 and 10 months, with junctional ectopic tachycardia and low cardiac output after surgical repair of the atrio-ventricular septal defect were treated with hypothermia after unsuccessful pharmacological attempts to control the arrhythmia. Generalized hypothermia was induced with cooling-blankets and ice packs. Rectal temperature initially dropped to 30 degrees and was subsequently maintained at between 33.8 and 34.2 degrees with the heart rate between 130 and 140 m beats per minute. Trans-oesophageal atrial pacing at a higher rate allowed for sequential atrio-ventricular contraction. Signs of low cardiac output were quickly resolved. One patient was warmed-up after 12 hours of hypothermia and remained in sinus rhythm. In the other patient, the arrhythmia recurred after rewarming and a further 30-hour period of hypothermia was required. Sinus rhythm was maintained thereafter. Both patients are in stable sinus rhythm 20 and 22 months after surgery. Our experience supports the use of hypothermia as a means to control post-operative junctional ectopic tachycardia resistant conventional anti-arrhythmic drugs.

Ventricular septal defect in Down syndrome. Anatomic types and associated malformations

Ventricular septal defect is a common cardiac anomaly in Down syndrome. To detect the prevalence of anatomic types and associated cardiac malformations we analyzed the echocardiographic and angiocardiographic findings of 73 children with ventricular septal defect and Down syndrome. We compared these results with those obtained in 303 patients with ventricular septal defect without Down syndrome. The prevalence of inlet ventricular septal defect was significantly higher in patients with Down syndrome, while muscular and subpulmonary ventricular septal defects were present only in patients without Down syndrome. The incidence of a cleft of the mitral valve was significantly higher in Down syndrome, while left-ventricular inflow and outflow obstructions were present only in patients without Down syndrome. Different patterns of ventricular septal defect and associated anomalies exist in patients with and without Down syndrome.

Relationship between QT interval duration and exercise-induced ventricular arrhythmias

This study was performed to determine if QT prolongation before and during early exercise is related to the occurrence of exercise-induced ventricular arrhythmias (EIVA). EIVA occurred in 47 of 142 patients with angiographic evidence of coronary artery disease (CAD); no EIVA occurred among the 22 patients without CAD (OV). Resting QTc and QT intervals during early exercise were similar in patients without EIVA, irrespective of the presence or absence of CAD; however resting QTc was significantly longer in CAD patients who showed EIVA (443 +/- 40 ms; P less than 0.01) than in CAD patients without EIVA (424 +/- 37 ms) and in OV patients (421 +/- 32 ms). During early exercise, the QT interval remained significantly longer in patients with than in those without EIVA. There was a trend toward increasing resting QTc in patients who exhibited EIVA more severe than grade 3. When resting QTc was longer than 440 ms, subsequent EIVA were correctly predicted in CAD patients with a sensitivity of 43%, a specificity of 72% and a predictive accuracy of 63%. Thus, a trend toward longer resting QTc values exists in CAD patients who develop EIVA; however, a long resting QTc (greater than 440 ms) appears to be only a weak predictor of subsequent EIVA.

[Pulmonary atresia with an intact septum: indications for the neonatal surgical treatment guided by 2-dimensional and Doppler echocardiography]

Twelve neonates with pulmonary atresia and intact ventricular septum underwent surgical treatment based on two-dimensional and Doppler echocardiography. Ten patients with adequate morphology of the right ventricular outflow tract portion shown by means of two-dimensional echocardiography underwent pulmonary valvulotomy and systemic-to-pulmonary shunt. Two neonates with atresia of the right ventricular infundibulum on two-dimensional echocardiography underwent systemic-to-pulmonary artery shunt without valvulotomy. In all patients the qualitative and quantitative echocardiographic diagnosis was confirmed at surgery and/or with the subsequent angiocardiographic study. Two-dimensional and Doppler echocardiography is a precise diagnostic method for planning surgical treatment in neonates with pulmonary atresia and intact ventricular septum.

Effects of aging and beta-adrenergic-blockade on standing-induced QT/QS2 changes

In order to evaluate whether the changes in the electrical systole/electromechanical systole ratio (QT/QS2) may reflect the effects of beta-adrenergic stimulation on the heart, we studied the variations of this ratio induced by active standing. We studied 45 healthy volunteers aged 15 to 82 years, subdivided into three groups; Group 1 (mean age 22 +/- 4 years), Group 2 (mean age 44 +/- 6 years), and Group 3 (mean age 74 +/- 6 years). Fifteen subjects repeated the test after propranolol administration (0.1 mg/kg iv). Resting QT/QS2 ratio increased slightly, but not significantly, with age. Upright position significantly increased QT/QS2 ratio in all groups. Changes in heart rate (r = -.43), electromechanical systole (r = .55) and QT/QS2 were significantly correlated with age. Propranolol prevented the increase in QT/QS2 ratio induced by active standing. Therefore, QT/QS2 changes induced by standing are correlated with age and are inhibited or reduced by beta-blockade. QT/QS2 changes can be used to monitor adrenergic activity, even if their value is limited by the overlapping responses of the individual cases.

Feeding gastrostomy in neurologically impaired children: is an antireflux procedure necessary?

Some authors recommend a routine "protective" antireflux procedure (ARP) in neurologically impaired children undergoing feeding gastrostomy (FG). Over 4 years, we performed FG in 107 neurologically impaired children aged 1 month to 16 years. Ninety-eight had preoperative radiological assessment for gastroesophageal reflux (GER), which was documented in 44, of whom 33 had FG plus ARP and 11 had FG alone. Seven of the 11 subsequently developed symptomatic GER and 5 of them had a secondary ARP. Of the 54 children with no demonstrable GER preoperatively, 3 children underwent FG plus ARP. The remaining 51 had FG alone. There was one postoperative death. Of the 50 surviving patients, 22 developed symptomatic GER and 17 of these had a subsequent ARP. Mean follow-up of 20.0 months showed that the risk of developing GER after FG alone was not influenced by age, sex, indication for FG, underlying diagnosis, or method of gastrostomy. There was no significant difference in mortality and early morbidity between patients undergoing FG alone and those having FG with simultaneous or subsequent ARP. Only 44% of our patients in whom GER was not demonstrated initially developed symptomatic GER followed FG alone. This incidence does not justify a routine "protective" ARP.

Selective damage of neuron perikarya in the medial septum of the rat forebrain: effects on food and water intake, urine output and body weight

The intraseptal administration of the neurotoxin kainic acid (KA) induced a significant depletion of the neuronal population and glial proliferation in medial septal areas. The behavioral effects induced by this selective destruction of the neurons indigenous to the medial septal areas were investigated. KA produced a marked increase in urine output and a transient reduction in body weight, but failed to affect water and food intake.

Relationship between QT/QS2 ratio and angiographic severity of coronary heart disease

The relationship between QT/QS2 ratio and angiographic severity of coronary heart disease (CHD) was determined in 99 patients who underwent coronary arteriography because of chest pain. Sixteen control patients with normal coronary arteriograms and normal left ventricular function and 83 patients with angiographic evidence of CHD were studied. QT/QS2 ratio and systolic time intervals were calculated from poligraphic recordings taken at rest. In control subjects QT/QS2 ratio was significantly shorter (0.91 +/- 0.04) than in patients with double (0.95 +/- 0.07; p less than 0.05 versus control subjects) and triple vessel coronary artery disease (0.95 +/- 0.05; p less than 0.05 versus control subjects). QT/QS2 ratio was significantly higher (p less than 0.01) in patients with 3 areas or more of left ventricular abnormal wall motion (LV AWM) (0.98 +/- 0.05) than in patients with none (0.92 +/- 0.06) or just 1-2 areas (0.93 +/- 0.06) of LV AWM. Multiple regression analysis revealed no relation between the number of coronary stenoses and QT/QS2 (t = 0.86; p = NS), while a relation was identified between the number of asynergic segments and QT/QS2 (t = 1.99; p less than 0.05). A significant correlation was found between QT/QS2 and PEP/LVET (r = 0.39; p less than 0.001). Setting the upper normal limit at 2 standard deviations from the mean of control subjects (QT/QS2 = 0.99), QT/QS2 criterion yielded a 30% sensitivity, a 94% specificity and a 96% predictive accuracy in diagnosing CHD. We conclude that in CHD patients QT/QS2 ratio is influenced by the extension of LV AWM. Although a low sensitivity may limit its use, a QT/QS2 value higher than 0.99 in a patient with chest pain strongly suggests CHD and thus this criterion may be diagnostically useful.

[Clinico-radiological observations on pulmonary manifestations of leptospirosis during the Montefeltro epidemic]

During the summer of 1984, in the Montefeltro area an epidemic of leptospirosis took place from a common source. In 15% of the people affected, the disease involved the lungs. In 3 patients the disease had a deadly course; one decrease was due to ARDS. The clinical, anatomopathological, and radiological features are described of the patients who presented with lung involvement. Such an outcome proved to be more likely than we thought. X-ray pattern of the chest was a polymorphous appearance, in spite of the same anatomopathological substratum, characterized by lung edema and endoalveolar hemorrhages.

Diagnostic value of the ratio of recovery systolic blood pressure to peak exercise systolic blood pressure for the detection of coronary artery disease

It has been previously reported that at treadmill exercise testing an abnormal ratio of recovery systolic blood pressure (SBP) to peak exercise SBP is more sensitive than exercise-induced angina or ST segment depression for diagnosing coronary artery disease (CAD). To investigate whether the SBP ratio keeps its diagnostic value during upright bicycle exercise, we evaluated the ratio of postexercise SBP to peak SBP in 73 patients with angiographically documented CAD and in 48 patients with normal coronary arteries (OV group) undergoing maximal stress testing on a bicycle ergometer. Three minutes after exercise ended, SBP ratio was significantly higher in the CAD than in the OV group (0.79 +/- 0.1 vs 0.71 +/- 0.08; p less than .001). Setting the upper normal limits of the recovery SBP ratio at 2 SDs from the mean for the OV group (SBP ratio = 0.98 and 0.88 at 1 and 3 min after exercise, respectively), with an increase or no change in SBP ratio at between 1 and 3 min of recovery considered an abnormal response, the sensitivity of SBP ratio was 30%, the specificity was 83%, and the accuracy was 51%. The respective values for ST depression were 81% (p less than .0001 vs SBP ratio), 48% (p less than .001 vs SBP ratio), and 67% (p less than .01 vs SBP ratio). Thus, for bicycle ergometer exercise testing, ST segment depression seems to be more accurate than SBP ratio in diagnosing CAD.

Neuroanatomical and biochemical evidence for the involvement of the area postrema in the regulation of vasopressin release in rats

Studies were carried out in the rat to determine if the area postrema (AP), a medullary circumventricular organ, might be involved in the control of vasopressin (VP) release. The data from this study demonstrate the existence of direct neural connections between the AP and the hypothalamic VPergic neurons of the supraoptic nucleus (SON) as showed by the retrograde tracer horseradish peroxidase (HRP). Labeled neurons were observed in the AP following HRP injections into the SON. In addition, rats with AP lesions showed an impaired ability to conserve water and concentrate their urine in response to an hypertonic NaCl load. They, also, failed to maintain sodium retention and showed an attenuation of VP release during intracellular dehydration. These findings indicate that AP plays an important role in the regulation of VP release during changes in osmotic environment and suggest that this medullary circumventricular organ is a part of central circuitry subserving salt-water balance.

Evaluation of exercise-induced Q-wave amplitude changes and their clinical value

We studied the influence of exercise level, severity of coronary artery disease (CAD), presence of previous myocardial infarction (MI), anterior or diaphragmatic, on the clinical value of exertional Q wave changes (Delta-Q). We retrospectively evaluated the exercise electrocardiograms of 62 patients without angiographic evidence of CAD and 133 patients with CAD; 28 of them had single (SVD) and 105 multivessel disease (MVD). Forty-one patients had a previous diaphragmatic MI and 23 anterior. The sensitivity, specificity and predictive value of Delta-Q were compared to the ST criterion. The exercise level affected Delta-Q. ST and Delta-Q had similar specificity and predictive values. The extent of CAD did not affect the sensitivity of Delta-Q and this method was better than ST to detect SVD patients. The Delta-Q criterion was equally as efficient as ST in MVD patients without MI and with diaphragmatic MI. The loss of septal forces on resting electrocardiograms made useless Delta-Q analysis on patients with anterior MI. The improvement of sensitivity in SVD patients by Delta-Q might be of clinical value since these latter are frequently not diagnosed by the ST criterion.

[Diagnostic value of changes in the Q wave induced by exertion]

In order to evaluate the diagnostic value of exercise-induced Q wave changes and its relationship with the extent of coronary involvement and presence and location of a previous myocardial infarction, we examined the stress electrocardiograms of 188 consecutive patients with chest pain. Coronary arteriography shoved single vessel disease (SV) in 28 patients and multivessel disease (MV) in 130 patients; a previous myocardial infarction was present in 64 patients. The Q wave amplitude was measured as average of ten values in CM5 at rest and at peak exercise; a Delta-Q less than 0, i.e. reduction or no change of Q wave at peak exercise, was considered a positive response for coronary artery disease. The Delta-Q criterion shoved a significantly better sensitivity than ST depression, as a whole, but this improvement was nullified when patients with anterior myocardial infarction were excluded; as well specificity of Delta-Q although better than ST, did not allow a significant improvement for the diagnostic value of stress test. We also evaluated the diagnostic accuracy for multivessel coronary artery disease of both criteria positive was 78% whereas the negative predictive value of both criteria negative was 91%. We concluded that the exercise-induced Delta-Q less than 0 is a good indicator of coronary artery disease, although not superior to ST depression; the negativity of both criteria seems to be highly reliable for the exclusion of multivessel coronary artery disease.

[Comparative evaluation using an ergometric test of the efficacy of the 3 major calcium antagonists on exertion stable angina]

Nifedipine, diltiazem and verapamil are three effective calcium-antagonists in the treatment of angina pectoris. We compared their effects on effort angina to evaluate whether one of them is more efficacious. The data were collected from 42 patients (37 males, 5 females; mean age 51 +/- 4) entering one of 3 different trials; the beginning of all trials comprised a two-week, single blind, placebo run-in phase. An exercise stress test was performed at the end of this period and it was considered as basal test for the statistical analysis. Then the 42 patients were divided in 3 groups of 14 and entered a double-blind, randomized phase of drug treatment. The 3 groups started 3 parallel trials: 1) placebo/nifedipine 60 mg/day; 2) placebo/verapamil 360 mg/day; 3) placebo/diltiazem 240 mg/day. The duration of each trial was of 6 weeks (3 weeks of treatment with placebo and 3 weeks with active substance). Exercise stress tests were performed at the end of each phase of the trials, and the resulting data were compared with the data of the test performed at the end of run-in period. Parameters evaluated were: heart rate, blood pressure and rate pressure product at basal conditions, at submaximal and peak exercise; moreover we considered workload, maximal ST segment depression, total exercise duration and frequency of exercise-induced angina. Verapamil reduced rate pressure product at basal condition; all three drugs reduced rate pressure product at submaximal exercise, but a significant statistical difference was found only for verapamil and diltiazem.(ABSTRACT TRUNCATED AT 250 WORDS)

[Renal oncocytoma. A diagnostic and therapeutic problem]

Renal oncocytoma is a more common entity as one may believe. Five cases and their sonographic features observed in six months are reported; in none of these cases was possible a secure diagnosis before the operation.

Multimedia document presentation, information extraction, and document formation in MINOS: a model and a system

MINOS is an object-oriented multimedia information system that provides integrated facilities for creating and managing complex multimedia objects. In this paper the model for multimedia documents supported by MINOS and its implementation is described. Described in particular are functions provided in MINOS that exploit the capabilities of a modern workstation equipped with image and voice input-output devices to accomplish an active multimedia document presentation and browsing within documents. These functions are powerful enough to support a variety of office applications. Also described are functions provided for the extraction of information from multimedia documents that exist in a large repository of information (multimedia document archiver) and functions that select and transform this information. Facilities for information sharing among objects of the archiver are described; an interactive multimedia editor that is used for the extraction and interactive creation of new information is outlined; finally, a multimedia document formatter that is used to synthesize a new multimedia document from extracted and interactively generated information is presented.

This prototype system runs on a SUN-3 workstation running UNIX'". An Instavox, directly addressable, analog device is used to store voice segments.

Non-invasive evaluation of autonomic tone changes during isometric exercise in normal subjects and in patients with coronary artery disease

In order to evaluate the clinical implications of QT/QS2 ratio during manoeuvres of sympathetic stimulation we studied the effects of handgrip (75% of maximal voluntary contraction) in 18 middle-aged normal subjects and in 16 patients with previous myocardial infarction. We also evaluated the effects of propranolol (0.1 mg/kg i.v.) in all normal subjects and in 10 of the 16 patients with coronary artery disease. At rest the two groups had similar heart rate, blood pressure, QT, QS2 and QT/QS2 ratio values. A significant increase in heart rate and systolic blood pressure was recorded during handgrip both in normal subjects and in patients with coronary artery disease; QT/QS2 significantly increased in normal subjects but did not show significant variations in patients with coronary artery disease, with significant differences between the two groups at peak exercise. Handgrip-induced QT/QS2 changes showed a marked variability both in normal and diseased subjects. After propranolol, QT/QS2 showed no significant difference at peak exercise in the two groups. The variability of ratio changes was nullified by the administration of the drug. These findings suggest that handgrip-induced QT/QS2 changes might be an expression of beta-adrenergic discharge. The clinical value of handgrip-induced QT/QS2 changes in detecting patients with coronary artery disease is limited by the variability of the response of the ratio observed in the two groups.

Use of the epinephrine test in diagnosis of coronary artery disease

Two-dimensional echocardiographic (2-D echo) and electrocardiographic (ECG) monitoring was performed in 53 patients with anginal chest pain during infusion of physiologic doses of epinephrine. Technically adequate 2-D echo studies were recorded in 45 patients. Of these 45 patients, 35 had significant coronary artery disease. Twenty-two patients showed ECG changes during the test (ECG sensitivity 63%), 13 of whom also showed wall motion abnormalities (2-D echo sensitivity 48.5%). Combined ECG and 2-D echo criteria of a positive test yielded a sensitivity of 74%. None of the 10 patients without coronary artery disease had electrical or mechanical abnormalities during the test (specificity 100%). Thus, the epinephrine test during simultaneous 2-D echo and ECG monitoring is a valid alternative to echocardiographic exercise stress testing. Furthermore, the adequate images obtained during the infusion allow better investigation of relation between wall motion abnormalities and ECG changes during myocardial ischemia.

Aortic false aneurysm following blunt trauma of the abdomen

A post-traumatic false aneurysm of the abdominal aorta was diagnosed 8 years after blunt abdominal trauma with blast, sustained during combat. Severe persistent backache with erosion of D12 and L1 vertebrae were the presenting symptoms. The aneurysm was repaired by tube graft replacement.

The effect of ischemia of the dog's colon on transmural migration of bacteria and endotoxin

The purpose of this investigation was to evaluate the effect of temporary ischemia created during the surgical preparation of the colon for resection on transmural migration of bacteria and passage of endotoxin through the ischemic wall of the canine colon. Eighteen dogs were used: in fourteen the colon was devascularized by ligating all marginal vessels. Aerobic and anaerobic cultures and washings for endotoxin assay were obtained from the surface of the bowel at intervals up to 6 hr after creating the ischemia. Peripheral and portal blood samples were also obtained at equal intervals for bacteriologic cultures and endotoxin assay. Bacterial transmural migration was examined in 10 dogs. In 6 of the dogs biologically marked bacteria were introduced into the colon via a rectal catheter before producing the ischemia. In 4 dogs radioactively labeled endotoxin was introduced into the colon in a similar fashion. In all the dogs, surface cultures, both routine and specific for the marked bacteria, were negative for the whole period of up to 6 hr after creation of ischemia. All portal and peripheral vein cultures were also negative. Transmural migration of endotoxin was investigated in 8 dogs, 4 of which served as controls and underwent a sham operation. In the 4 dogs in which the colon was devascularized endotoxin was discovered in peritoneal washings, and in portal and systemic blood samples, as early as 30 min after the preparation of the bowel was completed. In the control dogs endotoxin assays were negative throughout the experiment. In this model up to 6 hr of ischemia did not result in migration of bacteria through the ischemic wall. Endotoxin, however, entered the peritoneum and the blood very soon after producing the ischemia.

Cimetidine and renal allograft rejection

Cimetidine, an H2 receptor antagonist, has gained acceptance as a drug capable of preventing gastroduodenal complications in renal transplant recipients. In several reports, cimetidine's immunoregulatory role has been questioned and its possible interference with graft acceptance has been observed. Two kidney allograft recipients are reported here, in whom cimetidine administration was associated with acute graft deterioration, which was completely reversed when the H2 receptor blocker therapy was discontinued. The observations support the view that the drug has an immunological, rather than nephrotoxic, effect. Caution should be exerted, at this stage, with respect to the use of cimetidine in renal transplant recipients.

Ultrastructural analysis of the X1X2X3O sex chromosome system during the spermatogenesis of Tegenaria domestica (Arachnida)

An ultrastructural study was performed on the sex chromosomes (male X1X2X3O) during the spermatogenesis of Tegenaria domestica (Arachnida, Agelenidae). This study was carried out using random and serially cut sections. During pachytene and diplotene the three X chromosomes are longitudinally paired. Each of these consists of a central core of condensed chromatin, surrounded by a field of dense chromatin projections through which the chromosomes are in contact with one another. These projections may be responsible for the recognition and pairing of the sex chromosomes and in some way participate in their non-disjunction during anaphase I. A study of the structure and behaviour of the sex chromosomes during spermatogenesis is also presented. The available information on non-synaptonemal complex-mediated chromosome pairing and a systematization of sex chromosome structure in spiders are discussed.