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Biomedical subjects

R Maselli

Publications and source records attributed to R Maselli.

At least 37 records · Page 2Linked to original sources
PubMed1991

Transcutaneous oxygen pressure in systemic sclerosis: evaluation at different sensor temperatures and relationship to skin perfusion.

Transcutaneous oxygen pressure (TcPO2) and skin blood flow (as evaluated by laser doppler) (LD) were investigated in 24 systemic sclerosis (SSc) patients in sclerotic skin (dorsal aspect of the hand) and non-sclerotic skin (interscapular region) and in 24 controls matched for sex and age for the same sites. The two parameters were evaluated at 44 degrees C (temperature of the two sensors) in 13 patients and 13 controls, and at 36-37 degrees C in the remaining 11. At 44 degrees C, TcPO2 was lower in SSc patients than in controls for both sclerotic and non-sclerotic skin. At 37 degrees C there was no significant difference. At 44 degrees C, LD values were decreased in patients with respect to controls for both sclerotic and and non-sclerotic skin. In contrast, at 37 degrees C the values were increased in patients only for the sclerotic skin. It can be hypothesized that the increased LD values at physiological temperature are at least in part balancing a decreased tissue oxygen tension, then a normal TcPO2 is ensured. On the other hand, the decreased LD values at 44 degrees C, when TcPO2 is also decreased, indicates that there is an inability of SSc vessels to significantly increase their flow under the stimulus of a maximal hyperaemia-inducing temperature.

Adult↗
PubMed1991

Experimental allergic neuritis in the SJL/J mouse: dysfunction of peripheral nerve without clinical signs.

Experimental allergic neuritis (EAN) was studied in the SJL/J mouse and compared to EAN in the Lewis rat. The Lewis rat developed hind limb weakness and weight loss while the SJL/J mouse had no discernible clinical abnormalities. The SJL/J mouse, however, suffered subclinical damage to peripheral nerve (PN) myelin. Both species reproducibly developed electrophysiologic dysfunction of PN and histopathology confined to the peripheral nervous system (PNS). Understanding of autoimmune demyelination in the central nervous system was greatly enhanced by the development of experimental allergic encephalomyelitis in the SJL/J mouse. We believe that EAN in the SJL/J mouse could lead to a similar increase in our understanding of autoimmune demyelination in the PNS.

Action Potentials↗
PubMed1990

Sympathetic skin responses are decreased and lymphocyte beta-adrenergic receptors are increased in progressive multiple sclerosis.

Immune abnormalities, including deficient CD8 lymphocyte-mediated suppression, have been implicated in the progression of multiple sclerosis (MS). The peripheral sympathetic branch of the autonomic nervous system innervates the lymphoid organs and affects immune function. Animals with an ablated sympathetic nervous system develop more severe experimental allergic encephalomyelitis than control animals and exhibit an increased density of beta-adrenergic receptors on their lymphocytes. Experimental allergic encephalomyelitis shares many features with MS. Accordingly, we investigated the psychogalvanic skin reflex in patients with rapidly progressive MS and found that 13 patients (57%) lacked this sympathetic-mediated response. The density of beta-adrenergic receptors on lymphocyte subsets was increased in progressive MS, most notably on the CD8 suppressor/cytotoxic subset. B lymphocytes had the greatest number of receptors with 12.1 +/- 1.8 fmol/10(6) cells in control subjects and 18.7 +/- 2.6 fmol/10(6) cells in patients with MS. CD8 lymphocytes possessed an intermediate number of receptors with 3.4 +/- 0.4 fmol/10(6) cells in control subjects and 9.1 +/- 1.6 fmol/10(6) cells in patients with MS. CD4 lymphocytes demonstrated the fewest receptors with 1.2 +/- 0.1 fmol/10(6) cells in control subjects and 1.8 +/- 0.4 fmol/10(6) cells in patients with MS. No differences in the affinity or function (cyclic adenosine monophosphate levels in response to 10(-5) M (-)isoproterenol) of the adrenergic receptor were found when patients with progressive MS and control subjects were compared. Autonomic abnormalities in progressive MS and the increased beta-adrenergic receptor density found on CD8 lymphocytes may be related.

Adult↗
PubMed1989

Electrophysiologic studies on locked-in patients: heterogeneity of findings.

Somatosensory evoked potentials, brain-stem auditory evoked potentials and electroencephalograms were obtained from 9 patients with the diagnosis of 'locked-in' syndrome. No pattern of evoked potential abnormality was specific to this syndrome, with findings ranging from bilaterally normal to unilaterally or bilaterally absent. The evoked potential studies complemented radiographic findings in defining the extent of the lesion and revealed that a portion of the pontine tegmentum was usually involved. Pathology from 2 patients corroborated the findings of the evoked potential studies. The value of evoked potential studies of patients with locked-in syndrome is to provide early objective evidence of brain-stem involvement independent of the clinical examination, EEG and radiographic studies.

Adult↗
PubMed1987

Late denervation in patients with antecedent paralytic poliomyelitis.

The development of new weakness, fatigue, and pain decades after acute paralytic poliomyelitis is a recognized syndrome. We conducted a controlled study of this syndrome by analyzing clinical, electromyographic, and muscle-biopsy features in 18 patients with a history of poliomyelitis--13 reporting 1 to 20 years of new weakness and 5 without new symptoms. The patients with new weakness also reported new muscle atrophy (9 of 13) and fatigue (10 of 13), symptoms not reported by the controls. The age at the time of acute poliomyelitis, severity of poliomyelitis, residual disability, number of years since acute poliomyelitis, and age at the time of study were comparable in the weakening and control groups. Evidence of remote denervation consistent with antecedent poliomyelitis was demonstrated in all patients by electromyography or muscle biopsy or both. In addition, active denervation (as evidenced by spontaneous activity on conventional electromyography, increased jitter on single-fiber electromyography, or atrophic myofibers) was found in 12 patients in the weakening group and in all 5 controls. Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups. When muscle data from both groups were pooled, correlations were observed between the extent of past reinnervation and the degree of ongoing motor-unit instability. We conclude that the extensive reinnervation of denervated muscle that occurs in paralytic poliomyelitis may be followed by late denervation of the previously reinnervated muscle fibers. Electromyographic and muscle-biopsy evidence of ongoing denervation does not distinguish between stable patients with prior paralytic poliomyelitis and those with new weakness.

Adult↗
PubMed1987

Sympathetic skin response in diabetic neuropathy.

The sympathetic skin response (SSR) was studied in 47 diabetic patients selected for the presence of symptoms and clinical signs of peripheral neuropathy and in 24 normal control subjects. The SSR was present in all controls but was absent at the foot in 66% and at the hand in 27.7% of the diabetic patients. Absence of the SSR failed to correlate with other electrophysiologic parameters on routine nerve conduction and electromyographic studies. Although absent SSR was more often found in patients with symptoms of autonomic dysfunction (P less than 0.05), there was no correlation with any specific symptoms of autonomic involvement. The SSR was frequently absent, at least in the foot, in those patients with abnormal cardiac beat-to-beat variability (expiratory: inspiratory, E:I, ratio) and pupil cycle time (PCT). In addition there was a good correlation between the amplitude of the SSR and the value of the E:I ratio (r = 0.81, P less than 0.001). The SSR may be a valuable adjunct in the assessment of autonomic involvement in diabetic neuropathy, but its sensitivity requires further evaluation.

Adult↗
PubMed1986

Edrophonium: an aid in the diagnosis of acute organophosphate poisoning.

Unsuspected accidental cutaneous exposure to an organophosphate insecticide caused flaccid paralysis in a 10-year-old girl. Electromyogram demonstrated repetitive compound muscle action potentials in response to a single stimulus of nerve; decremental response, more prominent at higher rates of stimulation; worsening of decremental response after edrophonium injection; and normal nerve conduction velocities. Electromyogram with repetitive nerve stimulation and an edrophonium test may provide a simple and rapid method for diagnosis of acute organophosphate poisoning.

Action Potentials↗
PubMed1986

Clinical studies with an aldose reductase inhibitor in the autonomic and somatic neuropathies of diabetes.

Clinical investigations with the aldose reductase inhibitor (ARI) sorbinil in diabetic patients with neuropathy are described. Cardiac autonomic neuropathy was studied in 36 patients, in a double-blind, placebo-controlled, randomized, noncrossover trial. Patients received sorbinil (250 mg qd) or placebo over 6 weeks after a one-week baseline period. Diabetic control did not change over the study period, as indicated by unchanged glycohemoglobin. Response was assessed by expiration/inspiration (E/I) ratios on EKG during 6 c/min respiration and resting minimum heart rate, both measures of vagal function. In the sorbinil group, E/I ratios improved from 1.074 +/- 0.012 to 1.096 +/- 0.020 (P less than 0.03) with a slight decrease in the placebo group from 1.112 +/- 0.023 to 1.105 +/- 0.023 (P = NS). The difference between the week 6 and week 0 changes in each group was significant (P less than 0.01). Resting minimum heart rate decreased in the sorbinil group from 76.4 +/- 2.3 to 66.8 +/- 2.4 beats/min (P less than 0.001), with a mean change of 10 +/- 2. In the placebo group, heart rate was unchanged (77.9 +/- 3.9 to 77.5 +/- 3.3). The two sample t tests of the within-group differences were likewise significant (P less than 0.001). These changes in both E/I ratio and resting minimum heart rate are consistent with a sorbinil-related improvement in cardiac parasympathetic nerve function. Several isolated cases with apparent sorbinil-related improvement in autonomic symptoms will also be described. Studies of somatic neuropathy have previously shown improvement in nerve conduction velocities with sorbinil. In a study of 11 patients with severely painful diabetic neuropathy treated with sorbinil for 3 weeks [placebo-controlled in single-blind fashion (n = 8)], pains (as assessed on a 0 to 20 rating scale) improved from a mean score of 16 down to 8, with deterioration following drug withdrawal. Objective improvements in sensation and strength were observed in some cases. In this group of patients, statistically significant improvements in nerve conduction velocity, E/I ratios, and resting minimal heart rate, similar to those previously discussed, were also documented. Somatosensory-evoked potentials studies in the 36-patient study showed significant improvements in peripheral conduction and cortical responses. Sorbinil toxicity in 106 patients was 11.3%, with sex incidence of 7/73 males (9.6%) and 5/33 females (15.2%).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1983

Treatment of severely painful diabetic neuropathy with an aldose reductase inhibitor: relief of pain and improved somatic and autonomic nerve function.

11 patients with severely painful diabetic neuropathy previously unresponsive to numerous drugs were treated with an aldose reductase inhibitor ('Sorbinil'--Pfizer CP 45, 634); 8 also received a placebo. Response was assessed according to a 0-20 graphic rating scale for pain and by tests for motor and sensory nerve conduction velocities (NCV) and cardiac autonomic nerve function. 8 patients had moderate to marked relief of symptoms, generally beginning on the 3rd or 4th day of medication, 2 had equivocal responses, and 1 had no change. Each of 4 patients with diabetic amyotrophy reported striking improvement in pain and mild to moderate improvement in proximal leg muscle strength; 2 of these noticed improved sensory perception in their feet. Objective evidence of improved muscle strength was obtained in each of these 4 patients and of improved sensation in 3. On stopping medication, pain worsened in 7 of 8 responders, although generally with some delay, suggesting a carry over effect. During the course of treatment autonomic nerve function improved significantly in 6 of 7 patients tested and across the group, and NCV improved in 4 of 7 tested. Both of these variables deteriorated after withdrawal of the drug. A correlation between NCV response and clinical response was apparent. Very little toxicity was observed. These observations suggest that aldose reductase inhibitors may be important in the treatment of symptomatic somatic and autonomic neuropathies complicating diabetes.

Adult↗
PubMedDate not supplied

Activation of peripheral phagocytes in BCG-vaccinated subjects.

The role of polymorphonuclear leukocytes (PMNs) in the immune defence against intracellular bacteria has long been neglected. Only recently have studies begun to address this issue. In this study the behavior of peripheral PMNs in Bacillus Calmette-Guerin (BCG) vaccinated subjects was investigated. Twenty healthy and purified protein derivative-negative adults were studied before, and two and four months after, BCG administration. Luminol-amplified chemiluminescence (CL) emission was evaluated in whole blood phagocytes using a soluble stimulus, such as phorbol mirystate acetate, or particulates such as zymosan opsonized with homologous (OZH) or autologous (OZA) serum. Specific IgG, IgA and IgM against antigen -60 by ELISA, total immunoglobulin, C3 and C4 components of complement, were assessed by immunochemical tests. The results revealed a late heightened production of reactive oxygen intermediates in vaccinated subjects in presence of OZA and OZH. Our findings confirm that the role of PMNs and their mediators in immunoregulation of intracellular diseases needs to be re-evaluated.

Adolescent↗