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Biomedical subjects

P Martinelli

Publications and source records attributed to P Martinelli.

At least 19 recordsLinked to original sources
PubMed1995

Peri-operative assessment of glomerular permeability.

Surgical trauma may provoke an increase in glomerular permeability. Microalbuminuria is a subclinical increase in urinary albumin ranging from 20 to 300 mg..-1. This cannot be measured with routine laboratory tests and is estimated by radioimmunoassay. It has been proposed that microalbuminuria, an expression of increased glomerular permeability, serves to reflect a generalised increase in systemic vascular permeability. In this study the degree of microalbuminuria (expressed as microalbuminuria/creatinine ratio to correct for dilutional changes) has been measured in two groups of patients undergoing either videolaparoscopic surgery (group A) or conventional, open, abdominal surgery (group B). The anaesthetic technique was standardised and the duration of surgery similar in the two groups. A significant increase (p < 0.01) in the microalbuminuria/urinary creatinine ratio occurred in patients undergoing open abdominal surgery (group B). This alteration appeared 2 h after surgery but had disappeared 24 h after the end of the operation. During surgery, there was a direct relationship between glomerular permeability and the severity of the surgical insult.

Abdomen↗
PubMed1995

Familial spasmodic dysphonia with low arylsulphatase A (ASA) level.

Two familial cases of late onset spasmodic dysphonia and low Arylsulphatase A (ASA) are reported. In one case spasmodic dysphonia was associated with negative head tremor and orthostatic tremor, both displayed postural tremor of the upper extremities. A familial predisposition for both focal dystonia and metabolic lysosomal impairment is suggested by similar observations.

Aged↗
PubMed1992

Hemifacial spasm due to peripheral injury of facial nerve: a nuclear syndrome?

Four cases of hemifacial spasm (HFS) are reported. The spasm followed a few months after injury to a peripheral branch of the seventh nerve. An EMG examination of facial muscles disclosed the typical finding of HFS: spontaneous activity, paradoxical cocontraction, and diffusion of spontaneous or provoked blinking. A nuclear involvement, secondary to the nerve lesion, is the most likely pathophysiological explanation for similar cases in HFS.

Adult↗
PubMed1992

Kinetic-dynamic relationship of oral levodopa: possible biphasic response after sequential doses in Parkinson's disease.

The potential difference in the concentration-effect relationship of oral sequential doses of levodopa was explored in six Parkinsonian patients with complex fluctuating response. These patients showed "wearing-off phenomena" characterized by a transient worsening of motor function at the end of the first morning dose response to below baseline values and complained of a progressive reduction of levodopa effect during the day. A first standard levodopa dose was given in the morning, after an overnight fast and levodopa withdrawal. A second equal levodopa dose was administered immediately at the end of the first dose deterioration phase. Postimprovement worsening of motor response was also observed after the second levodopa dose in all patients. No significant difference in the pharmacokinetics of levodopa or in duration or magnitude of motor response could be appreciated between the two doses. These results further support the suggestion that, under controlled dietary conditions, plasma levodopa levels and effects relationship is reproducible between doses. Moreover, even when transient deterioration of motor function occurs between levodopa doses, the central dopaminergic system appears to remain responsive to the drug.

Adult↗
PubMed1992

Autonomic nervous system function in myotonic dystrophy.

Symptoms suggestive of dysautonomia are often reported in Myotonic Dystrophy (MD) patients. 12 patients with MD underwent cardiovascular function testing with assay of plasma noradrenaline (NA) and adrenaline (A) in supine rest condition and after orthostatic and cold stimulus. Statistical analysis showed no differences between MD patients and an age and sex matched control group.

Adolescent↗
PubMed1992

Chronic spastic atrophic hemiparesis with benign course.

We present the clinical and neuroimaging data of 4 patients (mean age: 62 years, range 54-67; mean follow-up: 19.5 years, range: 26 months-29 years) with chronic spastic atrophic hemiparesis (CSAH). Neuroimaging findings were non specific, CT scan and MRI showing white matter lesions located within the centrum semiovale in two cases, parieto-occipital lobe and pons in one case each. This study underlines that patients with CSAH may have a good long-term prognosis. MRI studies may demonstrate associated lesions within the white matter or brainstem and are advisable in all subjects with CSAH, but further studies are necessary to clarify the nature of the observed lesions.

Aged↗
PubMed1992

No effect of chronic bromocriptine therapy on levodopa pharmacokinetics in patients with Parkinson's disease.

We studied the effect of chronic bromocriptine cotherapy on levodopa kinetics in seven patients with Parkinson's disease who were receiving levodopa therapy. Plasma levodopa concentrations were measured after a standard oral levodopa fasting dose over a 5-hour period, on two different sessions, without and with bromocriptine at a fixed daily dose of 15 mg. We found no statistically significant difference in the rate and extent of levodopa absorption between the two treatments, with minimal intrasubject variability. Our observations suggest that chronic bromocriptine cotherapy is unlikely to affect the plasma levodopa pharmacokinetics under standardized intake conditions or to contribute to a less predictable pattern of drug plasma concentrations.

Aged↗
PubMed1992

Malpractice in obstetrics: a contribution of cases in southern Italy.

Looking ahead to the abolition of many intra-European frontiers the Authors offer this contribution to the discussion of the medico-legal aspects of gynecological activity in the United Europe of 1993. It is to this end that they present the data from a review of the material which has been the subject of litigation on the part specialists in Southern Italy, also commenting on the case series in the light of the Italian provisions in force up to date.

Abortion, Induced↗
PubMed1991

Efficiency of different criteria for selecting pharmacokinetic multiexponential equations.

Several statistical and empirical approaches have been proposed to select the multiexponential equation that best describes the time course of the plasma concentration of a drug. Recently, a new criterion (Ip) has been proposed according to which the model that best interprets a set of experimental data points is the one with the smallest area between the approximate confidence limits of estimated plasma concentration. We used large Montecarlo simulations to compare the ability of different selection criteria to select the correct model from data generated with an independent, normally distributed random error. The new criterion (Ip), Akaike's information criterion, the Schwartz test, and the F ratio test were studied. In this situation, the correct model was known and the performances of different selecting methods were assessed by examining their sensitivity to the number of exponential terms, the number of data points, and the size of the exponents in the true model. Mono-, bi-, and triexponential equations were studied. Overall mean percentages of right identification were 98.1 per cent for the new index, 82.8 per cent for Akaike's information criterion, 89.5 per cent for the Schwartz test, and 97.7 per cent for the F ratio test. The Akaike and Schwartz tests were not as efficient as the other tests with few (8-10) data points. The Ip and the F test raise the percentages of right identification of the model when the hybrid elimination rate macroconstants differ by at least a factor of four.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1991

Effect of age on the pharmacokinetics of oral levodopa in patients with Parkinson's disease.

The influence of age on the kinetics of a standard oral dose of levodopa administered with an inhibitor of peripheral dopa decarboxylase enzymes (benserazide) has been evaluated in 40 patients with Parkinson's disease (age 34-78 y) on chronic therapy. They were divided into 2 groups, on the basis of age below (21 patients, Group A) or above (19 patients, Group B) 65 y. The area under the plasma concentration-time curve (AUC) of levodopa was significantly greater in the older group (547 versus 428 mumol.l-1.min in Group B), coupled with a reduced apparent oral clearance (8.1 versus 10.7 ml.min-1.kg-1) and a longer plasma elimination half-life (67.6 versus 54.6 min). The age of the patients was positively correlated with the AUC of levodopa (r = 0.474) and its plasma elimination half-life (r = 0.391), and was negatively correlated with clearance (r = -0.489). The findings confirm previous data on volunteers that showed a reduction in the systemic clearance of levodopa due to age, which would probably account for the finding of a greater AUC of levodopa in older patients. The observed, age-mediated differences in levodopa pharmacokinetics, albeit statistically significant, were moderate and were likely to be of only minor importance for the dosing schedule.

Administration, Oral↗
PubMed1991

Muscle mitochondrial DNA deletion and 31P-NMR spectroscopy alterations in a migraine patient.

A 40-year-old female suffering from recurrent migrainous strokes is reported. She did not show any muscle weakness or wasting. Ragged red and cytochrome c oxidase negative fibers were present in the muscle biopsy. Muscle mitochondrial DNA analysis showed a 5 kb deletion, without a point mutation at nucleotide pair 3243 in the mitochondrial tRNALeu(UUR) gene. Phosphorus nuclear magnetic resonance spectroscopy of brain and gastrocnemius muscle showed a defective energy metabolism in both organs. An increased inorganic phosphate to phosphocreatine ratio due to a decreased phosphocreatine content was found in the occipital lobes, while an abnormal work-energy cost transfer function and a low rate of phosphocreatine post-exercise recovery were found in the muscle.

Adult↗
PubMed1991

Endothelial-derived relaxing factor released by endothelial cells of human umbilical vessels and its impairment in pregnancy-induced hypertension.

The principal objective of this study was to determine and compare the capability of human umbilical vessels of normal and pregnancy-induced hypertensive parturients to produce and to release the endothelial-derived relaxing factor. A bolus of bradykinin injected in the perfusion system of human umbilical vessels induces a release of a relaxant factor, detectable by bioassay, that is pharmacologically similar to the endothelial-derived relaxing factor. Human umbilical cords were collected from normal and pregnancy-induced hypertensive parturients. In the latter group the release of endothelial-derived relaxing factor is extremely reduced. In fact, in umbilical vessels collected from normal parturients, bradykinin at a dose of 20 pmol produces a release of endothelial-derived relaxing factor equivalent to a relaxation induced by 59.9 +/- 11.0 and 30.8 +/- 11.4 pmol of glyceryl trinitrate for the artery and vein, respectively. The same dose of bradykinin in umbilical vessels, collected from pregnancy-induced hypertensive parturients, produces a release equivalent to 6.6 +/- 2.2 and 5.7 +/- 3.5 pmol of glyceryl trinitrate equivalent for the artery and vein, respectively. Neither an increasing bolus of exogenous bradykinin or an infusion of superoxide dismutase or L-arginine was able to restore the production of endothelial-derived relaxing factor to normal levels. Our results indicate a probable alteration of endothelial cell numbers or an alteration of the enzymatic pathway, probably due to cytotoxic endogenous factors produced in pregnancy.

Animals↗
PubMed1991

Combined levodopa-anticholinergic therapy in the treatment of Parkinson's disease. Effect on levodopa bioavailability.

The effect of chronic intake of the anticholinergic drug orphenadrine on the bioavailability of levodopa was studied in six patients with Parkinson's disease. Plasma levodopa profiles and corresponding motor response to a standard dose of levodopa plus an inhibitor of peripheral L-aromatic aminoacid decarboxylase (benserazide) were followed, over a 5-h period, on two different sessions, with and without anticholinergic cotherapy. Six control patients were also included in the study for assessment of intrasubject variability in levodopa absorption under identical conditions. A considerable delay in levodopa absorption was found in one patient, and decreased absorption in an additional two patients while on anticholinergic. Patients' clinical performance corresponded well to plasma levodopa profiles. A significant impairment of basal clinical state was observed in two cases on anticholinergic withdrawal, probably as a result of pharmacodynamic interactions. Our observations suggest that chronic anticholinergic intake may contribute to a less predictable pattern of levodopa absorption and related therapeutic response in some subjects.

Adult↗
PubMed1991

Neuropathy caused by spontaneous intraneural hemorrhage: case report.

A case of ulnar neuropathy at the elbow produced by spontaneous intraneural hemorrhage in a patient with acquired immunodeficiency syndrome and thrombocytopenia is reported. Intraneural hemorrhage in patients with bleeding disorders occurs infrequently. It consists of acute intrafascicular bleeding, presumably producing very high elevations of endoneurial fluid pressure. The clinical features and treatment of this condition are considered, the pertinent literature is reviewed, and the involved pathophysiological mechanisms are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Sneddon syndrome presenting with hemicranic attacks: a case report.

The case of a young woman suffering from a rare cerebrovascular disease associated with livedo reticularis (Sneddon syndrome) is reported. Hemicranic attacks were the first symptom detected. The patient had a progressive clinical course of neurologic symptoms. Cerebral CT scan, NMR and cerebral arteriography revealed a progressive cerebral multifarctual feature involving middle-size arteries.

Adult↗
PubMed1990

Complicated migraine studied by phosphorus magnetic resonance spectroscopy.

The brain and skeletal muscle of eight adult patients with migraine with prolonged auras or migraine strokes leaving a permanent hemianopic defect were studied by phosphorus magnetic resonance spectroscopy. Biochemical assays performed on muscle biopsy and platelets had revealed abnormal mitochondrial enzyme activities. Brain magnetic resonance spectroscopy showed an abnormally low phosphocreatine to inorganic phosphate ratio in all patients, apparently due to decreased phosphocreatine and increased inorganic phosphate contents. Muscle phosphorus magnetic resonance spectroscopy showed low recovery from exercise in seven patients. Three patients had an increased phosphocreatine/inorganic phosphate ratio at rest, and the exercise transfer characteristics were abnormal in four patients for relatively low levels of exercise. The mitochondrial metabolic defects present in platelets and muscle of complicated migraine patients are therefore also expressed in the brain.

Adolescent↗