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Biomedical subjects

A Cavallini

Publications and source records attributed to A Cavallini.

At least 55 records · Page 3Linked to original sources
PubMed1998

Cerebral hemodynamics in primary headaches: the transcranial Doppler experience.

This paper is an extensive review of the use of transcranial Doppler (TCD) devices in "vascular" forms of headache, and a discussion of the possible occurrence of nonunivocal results, particularly in migraine with or without aura. Despite the large variability in findings, TCD is a noninvasive, safe, and reproducible method for studying hemodynamic phenomena which characterize the clinical profile of migraine and cluster headache attacks. Similarly, it can detect cerebrovasomotor reactivity to external/internal environmental stimuli, as well as responses to pharmacological (therapeutic or diagnostic) agents. Possible future applications of TCD in monitoring vasomotor changes in response to selective stimuli (sympathetic, neuropeptidergic, etc.) are also considered.

Cerebrovascular Circulation↗
PubMed1998

Long-term outcome of migraine.

Migraine prevalence increases from childhood up until 40 years of age, and thereafter declines. Several hypotheses can be advanced to explain the decrease in migraine with advancing age: (i) favorable effect of preventive treatments; (ii) increased mortality in migraineurs (due to higher vulnerability to other fatal diseases); (iii) cohort effect (increased incidence in young subjects); (iv) spontaneous remission. The first two theses are poorly supported by data in the literature. Although a cohort effect may exist, a spontaneous remission of migraine in middle and old age (at least partially due to the loss of sex hormone changes after the menopause in females) is the more likely hypothesis. In a small subgroup of patients (most of them drug abusers), migraine has a "malignant" course and changes into chronic daily headache. The risk factors for a poor outcome of migraine have been little studied. In a case-control study, we found that a history of head trauma and a long duration of contraceptive intake were risk factors for a bad outcome, whilst a long duration of prophylactic treatments had a protective effect.

Age Distribution↗
PubMed1998

A national neurological excellence centers network.

The most relevant problems related to the management of neurological disorders are (i) the frequent hospitalization in nonspecialist departments, with the need for neurological consultation, and (ii) the frequent requests of GPs for highly specialized investigations that are very expensive and of little value in arriving at a correct diagnosis. In 1996, the Consorzio di Bioingegneria e Informatica Medica in Italy realized the CISNet project (in collaboration with the Consorzio Istituti Scientifici Neuroscienze e Tecnologie Biomediche and funded by the Centro Studi of the National Public Health Council) for the implementation of a national neurological excellence centers network (CISNet). In the CISNet project, neurologists will be able to give on-line interactive consultation and off-line consulting services identifying correct diagnostic/therapeutic procedures, evaluating the need for both examination in specialist centers and admission to specialized centers, and identifying the most appropriate ones.

Computer Communication Networks↗
PubMed1998

Business management of headache centers.

Economic evaluation of the costs and benefits of a headache center or unit has become very important for headache specialists. Many of the problems concerning this "financial" approach to headache derive from the model of organization of the Headache Unit, which is dependent on the various approaches to healthcare practiced in the country considered. So far there are two models of headache center that are generally considered: the hospital-based center and the independent center. An argument favoring hospital-based headache clinics is the lower costs, primarily because of their functional connection with the services of a general hospital, i.e., neuroradiology, neurophysiology, routine laboratory analysis, etc. Another is that the headache specialist has the possibility to visit the patients presenting to the emergency room in the acute phase of headache. Independent clinics have greater costs, but are equally as effective as hospital-based models.

Ambulatory Care Facilities↗
PubMed1998

Clinical experience using the Androderm testosterone transdermal system in hypogonadal adolescents and young men with beta-thalassemia major.

beta-Thalassemia major is associated with a high prevalence of hypogonadotropic hypogonadism affecting adolescents and young men with this disease. The pharmacokinetics of Androderm, a non-scrotal permeation-enhanced testosterone transdermal system, was previously studied in this population using three application regimens designed to mimic the nocturnal secretion and circadian patterns of testosterone production characteristics of puberty and young adulthood. In regimen I, designed for prepubertal 14 to 16 year-olds, a single Androderm patch (2.5 mg/day nominal delivery rate) is applied at night and removed 12 hours later in the morning. In regimen II, designed for partially virilized 17 to 19 year-olds, a single Androderm patch is applied nightly for 24 hours. In regimen III, intended for virilized men aged 20 years and older, two Androderm patches (total dose of 5 mg/day) are applied nightly for 24 hours. This report presents the results of a 12-month open label study using these three Androderm regimens to treat nine hypogonadal males with beta-thalassemia (ages 16.8 to 31.8 yr). Our data show that Androderm produced physiologically appropriate testosterone levels, lowered SHBG levels, promoted growth and virilization, increased bone mineral density, and was generally well tolerated in this population of hypogonadal adolescents and young men with beta-thalassemia.

Administration, Cutaneous↗
PubMed1997

Opposite effects of L-arginine and nitroglycerin on cerebral blood velocity: nitric oxide precursors and cerebral blood velocity.

Nitric oxide (NO), a gaseous molecule synthesized in the arteriolar endothelium from the amino acid L-arginine (L-arg), has been identified as the previously described Endothelium-Derived Relaxing Factor (EDRF): nitroderivatives such as nitroglycerin are known to induce vasodilation via NO release. The aim of this study was to evaluate by Transcranial Doppler (TCD) monitoring any changes in cerebral hemodynamics induced by both the infusion of L-arg and the sublingual administration of nitroglycerin in 20 healthy subjects. L-arg infusion induced a significant increase in blood velocity compared to the baseline value (mean +/- S.D. percent change = 18 +/- 8.71; p<0.0001 ) and a slight but significant decrease in Pulsatility Index. By contrast, nitroglycerin was able to cause a significant decrease in blood velocity (mean +/- S.D. percent change = 24.8 +/- 7.68; p<0.0001), while leaving Pulsatility Index unchanged. These data suggest that L-arg and nitroglycerin, both hypothesized to use NO as the final product at the vascular level, result in opposite blood velocity patterns within the cerebral circulation. This may be due to the particular type of artery and/or to the local endothelial environment whereby the released NO may act.

Adult↗
PubMed1997

Cerebral cavernous angiomas: an atypical case in infancy.

Cerebral cavernous angiomas (CCA) are rare, reportedly accounting for only 1% of all intracranial vascular lesions and 15% of all cerebral vascular malformations. Forms are sporadic or familial, and the mode of inheritance is probably autosomal dominant. We report an unusual case of an infant born at 37 weeks of gestational age following a normal pregnancy. Her birth-weight was 1560 g. The family history was negative. At 10 months of age, the child presented with the sudden onset of muscular hypotonia, motility and strength deficits, and absence of osteotendinous reflexes in the right arm. The psychomotor development of the child was normal. MRI revealed the presence of a cavernous angioma in the paramedian pontine region. The child's monoparesis quickly disappeared. This case is interesting because of the age at onset and the way in which the clinical manifestations developed.

Brain Neoplasms↗
PubMed1997

Probabilistic investigation of the life behavior of power capacitors operating under distorted supply voltage.

A probabilistic approach to the problem of life evaluation of power capacitors subjected to non-sinusoidal voltage is presented. In order to account for the stochastic nature of harmonic distortion, a probability density function representing the random occurrency of non-sinusoidal voltages is employed, while the stress-failure time relationship is provided by a multi-stress life model appropriate for life evaluation of a polymeric insulation. In such a way, the knowledge of harmonic amplitude distributions provides that of stresses affecting insulation life, i.e. electric field and temperature. Thus, life evaluation under distorted supply voltage is allowed, and comparison can be made with respect to performance in sinusoidal conditions.

Electric Conductivity↗
PubMed1996

Epidemiology of cholelithiasis in southern Italy. Part II: Risk factors.

OBJECTIVE: To determine behavioural, dietary and other common factors associated with new cases of gallstones, diagnosed by ultrasonography, in a prospective cohort study conducted in southern Italy. SUBJECTS AND METHODS: Between May 1985 and June 1986, systematic sampling from the electoral register of Castellana, a small town in southern Italy, yielded 2472 subjects who had had their gallbladder checked for gallstones by ultrasonography. Between May 1992 and June 1993, 1962 out of the 2235 (87.7%) subjects without gallstones at baseline agreed to a further ultrasound examination. At the first survey a standardized questionnaire was administered, inquiring about medical history, diet, cigarette smoking and other behavioural characteristics. Height and weight were also measured, and blood levels of glucose, cholesterol, HDL-cholesterol and triglycerides were determined by standard methods. The same variables were measured at the second survey. The diagnosis of gallstones was made with the same echograph by echographists working in the same department. Multiple logistic regression was used to determine which factors measured at the first survey were associated with the incident cases of gallstones. RESULTS: One hundred and four subjects had developed gallstones, an incidence of 9.7 per 1000 persons per year. Age, body mass index (BMI), weight change, a history of diabetes, constipation (shown by use of laxatives), cigarette smoking, years of schooling, consumption of fried foods and excessive oil, and pregnancy in females, were positively associated with the incidence of gallstones. Consumption of wine, coffee, fish and wholemeal bread was inversely associated. Sex, family history of cholelithiasis, use of oral contraceptives and serum lipids were not independent risk factors for gallstones. CONCLUSION: The results of this study confirm many gallstone-associated factors reported in previous cross-sectional and case-control studies, as well as in other cohort studies based on the clinical diagnosis of gallstones, such as BMI, ageing and wine consumption. Furthermore, use of laxatives, considered a proxy of constipation, appears to be another important independent risk factor for gallstones.

Adult↗
PubMed1996

Cytophotometric determination of heterochromatin base composition in interphase nuclei of plant cells.

The use of DNA base-specific fluorochromes and static cytophotometry at different thresholds of fluorescence intensity is proposed for studying the base composition of differently condensed chromatin fractions in plant interphase nuclei. Results are reported of such analyses on nuclei from leaflets of Posidonia oceanica and Helianthus annuus, which confirm other findings obtained on the same materials by biochemical and molecular methods.

Base Composition↗
PubMed1995

Low density lipoprotein receptors and polyamine levels in human colorectal adenocarcinoma.

The low density lipoprotein receptor (LDLR) is a cell surface protein that binds with LDL, providing the cell with cholesterol for new membrane synthesis. Rapidly growing cells have high numbers of LDLRs, and these proteins have also been detected in neoplastic samples of human colorectal mucosa. Polyamines, putrescine, spermidine, and spermine, play an important role in cellular growth, and studies on colorectal cancers have demonstrated higher polyamine levels in neoplastic mucosa samples than in surrounding mucosa. The aim of this study was to investigate LDLR and polyamine levels in the neoplastic tissue of 43 patients (28 males and 15 females) with colorectal adenocarcinoma, using enzymatic immunoassay and high performance liquid chromatography, respectively. Specimens of neoplastic mucosa were considered LDLR-positive or LDLR-negative when the amount of bound human anti-LDLR antibody detected was equal or higher or lower than the cut-off value (0.5 ng of bound anti-LDLR Ab/mg protein), respectively. Twenty-one subjects were LDLR-positive and 22 LDLR-negative. Polyamine levels (nmol/g tissue) were higher in LDLR-positive specimens; this increase was significant for total polyamines (P < 0.05). These findings, reporting the presence of increased polyamine content in LDLR-positive colorectal neoplastic specimens, suggest an association between LDLR levels and gastrointestinal neoplastic proliferative activity.

Adenocarcinoma↗
PubMed1995

Classification of chronic daily headache by International Headache Society criteria: limits and new proposals.

We conducted a retrospective study of 150 patients with chronic daily headache (CDH) to determine how to categorize their headache according to the classification of the International Headache Society (IHS). All patients were first evaluated at Parma and Pavia Headache Centres (from January 1992 to March 1993) and had had headache for at least 15 days a month during the previous 6 months. Four patients were thereafter excluded due to poor reliability. The 146 patients who met our CDH criteria (92 with and 54 without clear-cut migraine attacks) could be classified into four groups: (i) chronic tension-type headache (CTTH)--27 patients; (ii) coexisting migraine plus CTTH--65 patients; (iii) unclassifiable daily headache--27 patients; and (iv) migraine and an unclassifiable interval headache--27 patients. Seventy-two percent of patients with CDH had migraine as the initial form of their headache. We therefore propose to revise the IHS classification for migraine, taking into account its evolution, and add two subcategories, migraine with interparoxysmal headache and chronic migraine.

Adolescent↗
PubMed1995

Increased cerebral blood flow velocity induced by cold pressor test in migraine: a possible basis for pathogenesis?

Noradrenergic nuclei of the locus coeruleus are believed to be involved in migraine pathogenesis. We recently demonstrated a typical intracerebral vasoconstriction after prolonged (5 min) exposure to cold pressor test (CPT), likely related to a central noradrenergic mechanism modulated at the locus coeruleus level and eliminated by pretreatment with clonidine. In the present study, we used transcranial Doppler ultrasonography to monitor blood flow velocity (BFV) changes to CPT in the middle cerebral artery (MCA) of migraine with (MA, n = 12) and without (MO, n = 15) aura subjects. CPT induced a significant increase in BFV and a concomitant decrease in the pulsatility index (PI), a pattern which is the opposite of the results obtained with controls. The results were comparable when controls were pretreated with clonidine. The MO patients produced an intermediate pattern between the MA and control subjects. A possible altered modulatory effect of opioids and/or serotonin on noradrenergic nuclei of the brainstem is the possible cause of the observed inverse response in migraine, suggesting intracerebral vasomotor instability in these patients.

Adult↗
PubMed1995

Headache and quality of life.

The present prospective-type study quantified, by way of and ad hoc questionnaire, the impact of the headache attack in its various manifestations and the effect of headache on the quality of life of 400 headache sufferers. In addition, the functional status of episodic headache patients has been compared to that of patients with chronic daily headache. We observed that during headache attacks, episodic headache patients were significantly more disabled by physical symptoms. On the contrary, patients with chronic daily headache showed a significantly greater occurrence of emotional disturbances. A difference was detectable for mental health which was significantly more compromised in chronic daily headache than in episodic headache patients (P < 0.05). During the interictal period, quality of life appeared more compromised in chronic daily headache than in episodic headache patients. Chronic daily headache subjects were characterized by higher disability scores in all the sections considered. The results of this investigation confirm that headache negatively influence a patient's quality of life not only during attack phases but also during interictal periods and underline the importance that future studies on the efficacy of headache treatments should also evaluate the impact on patient's quality of life.

Adolescent↗
PubMed1995

Quantification of headache disability: a diagnostic-based approach.

The quantification of the social and economic handicaps caused by headache is a complex problem, especially given the great variability of headache patients' clinical pictures. In the present study, 400 patients, consecutively admitted to Headache Centers in Pavia and Milan, were interviewed on the relationship between headache and their work and social activities, in order to evaluate their socioeconomic handicap due to headache. The analysis of the data primarily focused on attack-type headaches (migraine, cluster headache, and episodic tension-type headache) and chronic or daily headaches (chronic tension-type headache and migraine combined with tension-type headache). These latter types were often characterized by the daily use or abuse of analgesics. The overall profile which emerged from the study reveals relatively low levels of handicap or disability in work and social activities. These low levels can be mainly attributed to timely, and at times excessive, use of analgesics.

Absenteeism↗
PubMed1995

[Therapeutic guidelines for headache].

Guidelines have been recently introduced in clinical practice in order to improve the quality of patient care reducing health-care costs. In 1993 the Italian Headache Society has published the "Guidelines and recommendation for the treatment of migraine" based on a wide revision of the existing literature and a consensus conference of Italian headache experts. These guidelines include the information necessary to make a correct diagnosis and to identify the best symptomatic and/or prophylactic migraine treatment. Until now guidelines for the treatment of tension-type headache and cluster headache are not available. However we can refer to the "Treatment recommendations" proposed by the Educational Committee of the International Headache Society. These suggestions indicate common practice and give precise information about types and dosages of the drugs utilizable for the prophylaxis and for the treatment of attacks.

Cluster Headache↗
PubMed1994

Continuing loss of vertebral mineral density in renal transplant recipients.

This cross-sectional study examined bone abnormalities by digital radiography, bone densitometry and biochemical tests in 44 clinically asymptomatic renal transplant recipients 6-195 months after renal transplantation. Abnormal radiographs were obtained in 40 of the 44 patients. Dual-energy X-ray absorptiometry (DXA) performed at the lumbar spine (L2-L4)/showed a negative Z score in all patients, ranging from -1 to -1.9 in 28 patients and less than -2.0 in 16 patients. The severity of osteopenia increased with the length of time after transplantation and there was a significant correlation with parathyroid hormone values in patients with normal and low glomerular filtration rates. Our data suggest that decreased bone density values (Z score less than -2) are present in about one-third of patients with renal transplants. Bone loss appears to continue after transplantation. Steroid therapy and immunotherapy are probably the cause of this bone loss. Bone mineral measurements alone are helpful in identifying asymptomatic patients with low bone mass after transplantation.

Absorptiometry, Photon↗