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Biomedical subjects

M Rizzo

Publications and source records attributed to M Rizzo.

At least 181 records · Page 10Linked to original sources
PubMed1989

Colored hearing synesthesia: an investigation of neural factors.

We studied a 17-year-old boy with colored hearing synesthesia (chromesthesia) using psychophysical and neurophysiologic tests. Specific musical notes consistently evoked the same color hues. Unlike controls, he could make new musical note-color associations in a single trial. Auditory evoked potential studies showed no evidence of abnormal activation. The results in this subject do not favor the notion that chromesthesia was due to aberrant neural transmission in collateral pathways, and support the alternative hypothesis that chromesthesia results from strong cross-modal associative ability.

Adolescent↗
PubMed1989

Pharmacokinetics, endocrine and antitumour effects of leuprolide depot (TAP-144-SR) in advanced prostatic cancer: a dose-response evaluation.

Twenty-two patients with advanced prostatic cancer and one with benign prostatic hypertrophy were given the GnRH analogue leuprolide in the form of a slow-release depot formulation by subcutaneous injection at doses of 3.75, 7.5, 15 or 30 mg. Following the first dose, drug levels were measured by a double-antibody RIA over an observation period of 5 weeks. Thereafter patients continued long-term subcutaneous treatment at the same dose every 4 weeks. Serum levels of leuprolide showed a rapid increase immediately after injection, reaching a peak proportional to dose within 3 h (range of mean values 13.1-54.5 ng/ml). Subsequently, mean drug levels declined to a plateau proportional to dose (0.49-1.99 ng/ml at 5 weeks). A significant dose-dependent increase in the area under the serum concentration-time curve from zero to 35 days (AUC0-35 days) from 541.7 to 1653.9 ng/ml.h was also noted (p less than 0.01). With all doses there was an initial rise in serum LH and FSH, followed by a rise in testosterone and dihydrotestosterone, then a sharp decrease within 3 weeks. FSH inhibition was achieved in all the 20 evaluable patients and was maintained in 17 of them (85%) over 5 weeks. Fifteen subjects (75%) had marked suppression of LH levels. In 13 of them (65%) this condition continued for the entire observation time. Castration levels of serum testosterone and dihydrotestosterone, however, were maintained in all patients for up to 5 weeks. Two of the 21 evaluable patients (10%) had a complete response; 15 a partial response (71%) and 3 stable disease (14%). No significant differences were observed in relation to dose. Clinical improvement and serum hormonal changes support this as a new and superior method of administration of leuprolide at a dose as low as 3.75 mg.

Aged↗
PubMed1988

In vivo release of angiotensin II from the rat hypothalamus.

Recent studies suggest that angiotensin II is released from neuronal tissue in vitro, but the occurrence of this phenomenon in the intact brain has not yet been demonstrated. To characterize the in vivo release of immunoreactive angiotensin II, push-pull cannulas were positioned in the anterior hypothalamus in 47 Sprague-Dawley rats (200-250 g) anesthetized with Inactin (100 mg/kg i.p.). Artificial cerebrospinal fluid was perfused at 20 microliters/min, and effluent samples were collected for 15-minute periods over 2 hours. Angiotensin II was detectable (greater than 2.5 pg/ml) in the push-pull cannula perfusate of the majority (76%) of the rats. Spontaneous release of immunoreactive angiotensin II was constant for 2 hours in 11 rats at values averaging from 4.4 +/- 1.5 to 8.2 +/- 2.2 pg/ml. In addition, bilateral nephrectomy performed 48 hours before did not affect the detection of angiotensin II (n = 3). Angiotensin immunoreactivity in the rat hypothalamus was further characterized by high performance liquid chromatography. The analysis showed that the perfusate contained authentic angiotensin II as well as other angiotensin metabolites. The effect of beta-adrenergic modulation on the release of angiotensin II was assessed in 20 rats by adding isoproterenol (10(-10), 10(-8), and 10(-6) M), propranolol (10(-6) M), or a combination of both. Neither activation nor inhibition of hypothalamic beta-receptors altered the spontaneous release of angiotensin II. These data demonstrate that angiotensin II and congener peptides are detectable in the microenvironment of the anterior hypothalamus of the anesthetized rat and that the release of angiotensin II immunoreactivity in the anterior hypothalamus is not modified by beta-adrenergic receptors.

Angiotensin II↗
PubMed1987

The role of scanpaths in facial recognition and learning.

We carried out a comprehensive assessment of eye movements in 2 subjects with impaired facial learning and recognition to determine if the defect might be associated with abnormal scanning of faces. Standard electroculogram showed that fixation, pursuit, saccades, and scanning of salient features of scenes and faces were normal, indicating that the defect was not due to abnormal scanning. However, study of the transitional properties of scanning revealed that the scanpaths of personally meaningful familiar faces, whether or not they were consciously recognized, were less predictable than those of other faces. This result indicates the existence of an internal and relatively specific schema for familiar faces sufficient to alter the "predictable" scanpath used for nonfamiliar faces. This internal schema is accessed even when conscious recognition fails, i.e., when other pertinent memories related to the possessor of the face are not evoked. The meaning of this finding is comparable to that obtained with autonomic studies of covert recognition in prosopagnosia and suggests that properties of scanning can be used as an index of higher neural processing.

Discrimination Learning↗
PubMed1987

Neglect in a patient with multiple sclerosis.

We report a patient with multiple sclerosis (MS) who developed left-sided neglect. Although MS is commonly associated with mental status changes, we believe that this is the first reported case of hemineglect. The deficit is probably related to the location, acuteness, size, and right hemispheric predominance of lesions in this patient.

Adult↗
PubMed1987

Looking but not seeing: attention, perception, and eye movements in simultanagnosia.

We studied three subjects who reported the apparent "disappearance" of stationary objects from direct view. They had simultanagnosia caused by CT-verified bilateral superior occipital lobe lesions. They had no abnormalities of visual acuity or fields to explain their defect. EOG with computer analysis showed intact motility and scanning. Most important, the subjects reported intermittent disappearance of a light target during EOG-verified fixation--ie, they were looking but not seeing. Results indicate that attention mechanisms that permit sustained awareness of visual targets depend on the superior visual association cortices and are relatively separate from mechanisms that shift gaze and drive visual search.

Aged↗
PubMed1986

Spatial contrast sensitivity in facial recognition.

Recognition and learning of complex images may depend on spatial processing characteristics of the visual system. Prosopagnosia, an impairment of visual learning and recognition of faces, might result from impaired perception in spatial channels carrying crucial information. We studied spatial contrast sensitivity (SCS) in two subjects with stable facial recognition defects. One had relative SCS reduction for high-frequency gratings but could process high frequencies in room light. The other had normal SCS. Both had intact spatial processing relative to image size. The results suggest that impairments in visual spatial channels are not necessary for the development of prosopagnosia.

Adult↗
PubMed1985

[Congenital cytomegalovirus infections in a neonatal pathology unit].

In order to evaluate the incidence of congenital CMV infections we checked 200 babies in the special care baby unit of an obstetric clinic in Milan. In the same period 3779 babies were born in that clinic. Congenital CMV infection was diagnosed by virus isolation from urine specimens collected in the first week of life in two babies. One of them was asymptomatic, the other had the classical CID. Virological confirmation of a further CID observed in an infant hospitalized at that time in the unit was obtained. Different serological methods of congenital infections diagnosis, specific IgM, total IgM and IgA, rheumatoid factor determinations, were employed. Only the CMV-IgM ELA method didn't give false positive reactions and picked up 2 congenitally infected babies out of 3. From our data, we infer that the incidence of congenital CMV infection in the general milanese population might lie between 0.5-1% of live births. The level of seropositivity for CMV antibodies in the same population, as judged from the complement fixing antibodies determinations in the group of the mothers, was 87%.

Cytomegalovirus Infections↗
PubMed1984

Cadmium concentrations in blood and urine of pregnant women at delivery and their offspring.

The levels of cadmium in blood (CdB) and in urine (CdU) were measured in 40 women at delivery and in their offspring. The women were not occupationally exposed to cadmium. The CdB levels in the pregnant women were significantly lower than in a control group consisting of 40 subjects of the same sex and age living in the same area. The difference can probably be ascribed to the physiological hemodilution that takes place in pregnancy. The CdU levels in the two groups were identical, which suggests that no mobilization of the metal from tissue deposits occurs during pregnancy. The presence of cadmium in the blood and urine of the newborn demonstrates that cadmium crosses the placental barrier. There was a rather high correlation between the CdU levels of mothers and offspring. Since only traces of cadmium are present in tissues at birth, it is speculated that the CdU levels in the newborn are influenced by the tissue deposits of cadmium in the mother. Further research is required to ascertain whether, in the case of women occupationally exposed to cadmium or living in cadmium polluted areas, transfer of the metal across the placenta can produce toxic effects in the foetus.

Adolescent↗
PubMed1984

Clinical aspects of augmentation enterocystoplasties.

Augmentation enterocystoplasty was performed in 28 patients with tuberculous, interstitial, radiation and chronic bacterial cystitis and hypertonic neurogenic bladder. Better results were observed in tuberculous contracted bladders where the extent of bladder resection and the bowel segment used were not related to the surgical outcome. In the other forms, the ileocecal segment is preferable. In our experience patients with neurogenic bladder did not benefit from the procedure. Radiographic and urodynamic studies are valuable for an accurate follow-up; radioisotope scan is also useful in selected cases. Anatomical and surgical causes of failure are discussed. Pharmacologic treatment is useful in partial surgical failure and provides indications for further bladder neck surgery.

Adolescent↗