Biomedical subjects
Publications and source records attributed to G Rapisarda.
A rare case of a bilateral Leydig cells tumour located in the testis of a 15-year-old donkey slaughtered normally is presented. Histologically, the testicular tumour showed neoplastic Leydig cells arranged in solid growth as a pseudoadenomatous packet type. To our knowledge, this is the first bilateral Leydig cells tumour, a neoplasm never reported in the donkey.
A case of preputial glomangioma in an 8-year-old Springer Spaniel dog is reported. The dog presented a solitary nodular mass, approximately 3.5 x 5.2 cm in diameter, located on the lateral wall of the prepuce at the base of the penis. Histologically, the excised tumour mass consisted of proliferating round epithelioid cells arranged in a cordon-like structure around small blood vessels. The neoplastic cells were positive for alpha smooth muscle actin and negative for cytokeratin, desmin, S-100 protein and neurone-specific enolase. Based on these pathologic features, the tumour was diagnosed as glomangioma, a neoplasm extremely rare in dogs. To our knowledge, this is the first report of preputial glomangioma in the dog.
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Here we present a case of preputial benign fibrous histiocytoma in a 7-year-old mule. This case was treated surgically. Pathologic analysis and diagnosis of these lesions were based on a combination of light microscopy and immunohistochemistry. Histologically, the tumour was composed primarily of a storiform pattern of fibroblastic and poligonal cells. In immunohistochemistry, except for consistent immunoreactivity for vimentin, nearly all tumour cells were positive for CD68, S-100 protein, pan-cytokeratin, alpha-smooth muscle actin, and desmin. Benign fibrous histiocytoma of the prepuce in mule is rarely reported in veterinary literature.
One case of interstitial cell tumour in the testicle of a New Zealand White rabbit was reported. The rabbit was 9-years old and had monolateral testicular lesion. There was enlargement of left testis and the lesion were seen on the cut surface. Light microscopy revealed intracytoplasmic crystals of Reinke that resembled to the features observed for this tumour in human. Immunohistochemically, this tumour was positive for vimentin.
OBJECTIVES: The objective of this study was to assess the sensitivity of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) in demonstrating the possible subclinical impairment of the corticospinal pathway after recovery, in patients with a clinical history of pure motor stroke (PMS) due to a single lacunar infarct detectable by magnetic resonance imaging (MRI). METHODS: MEPs were recorded from the first dorsal interosseous muscle of 20 healthy subjects and 40 patients, 6 months or more after PMS onset. Patients were evaluated clinically by means of the NIH stroke scale, the Medical Research Council (MRC) scale and the Barthel Index. The patients with full hand strength recovery and the normal controls were also tested by means of the 9-hole peg test. RESULTS: Motor threshold (MT), MEP amplitude and central motor conduction time (CMCT) of the affected side were significantly different from those of the normal side and of the control subjects. MT, MEP amplitude and CMCT obtained after stimulation of the affected hemisphere were significantly correlated with the MRC scale values of the affected hand. Eighty-six percent of patients with persistent hand strength deficit showed MEP abnormalities. In 21 patients with complete clinical recovery, a significant increase in MT and decrease in MEP amplitude on the affected side were observed. CONCLUSIONS: After PMS, neurophysiological changes may persist despite complete clinical recovery. TMS represents a sensitive tool that enables to demonstrate objectively the clinical and subclinical impairment of the corticospinal pathway.
OBJECTIVES: To evaluate central motor conduction to lower limbs in spinocerebellar ataxia type 2 (SCA2). METHODS: Transcranial magnetic stimulation was performed to study the corticospinal tracts of 18 patients with SCA2. RESULTS: Central motor conduction time (CMCT) to lower limbs and thresholds were abnormal in 8 patients (44%); CMCT and thresholds were significantly correlated with disease duration and disability. CONCLUSIONS: Corticospinal tract involvement is more frequent than previously reported in SCA2. Prolonged CMCT and increased threshold should not be used to differentiate between various type of autosomal dominant cerebellar ataxia. Similar to that reported in Friedreich's ataxia, we suggest that examining central motor conduction to the lower limbs may assist in evaluating the progressive steps of neurodegeneration in SCA2.
In order to determine the mono- or oligosynaptic character of connections between pyramidal axons and individual spinal motor neurons, we constructed peri-stimulus time histograms (PSTHs) of the firing probability of voluntarily activated single motor units (SMUs) of various upper and lower limb muscles upon slightly suprathreshold transcranial anodal electrical stimulations of the motor cortex in normal subjects. Weak anodal cortical stimuli are known to activate preferentially fast-conducting pyramidal axons directly, bypassing cell bodies and cortical interneurons. A narrow bin width (0.1 ms) was chosen to measure precisely the duration of the PSTH excitatory peak, which corresponds to the rise time of the underlying compound excitatory post-synaptic potentials (EPSP). A short duration PSTH peak indicates sharp-rising EPSPs, most commonly encountered in the case of monosynaptic connections. In flexor carpi radialis and soleus SMUs, the PSTHs of built-in responses to anodal cortical stimuli were compared with those produced by 1A afferent stimulation able to elicit a Hoffmann reflex, which is known to be largely monosynaptic. In all upper and lower limb muscles, excitable SMUs responded to anodal cortical stimuli with a highly synchronized peak of increased firing probability. In flexor carpi radialis and soleus SMUs, the mean duration of this peak was significantly narrower than that evoked by 1A afferent stimulation, indicating that monosynaptic corticomotor neuronal transmission dominates low-threshold motor units, even in proximal arm and leg muscles. In the various muscles studied, and particularly in forearm SMUs, we did not observe broad PSTH peaks against the activation of non-monosynaptic corticomotor neuronal pathways, even with near-threshold stimuli. In some triceps and forearm flexor SMUs, subthreshold anodal pulses caused significant inhibition of their voluntary firing, with a latency consistent with activation of 1A inhibitory interneurons by the descending volleys. Measurements of the maximal number of counts in the excitatory PSTH peak upon anodal cortical stimuli provide comparisons of the strength of monosynaptic inputs to various muscles which seems to be maximal for hand and finger extensor muscles, and also for deltoid.
BACKGROUND AND PURPOSE: Transcranial magnetic stimulation (TMS) has been proposed as a prognostic tool in stroke patients. Most of the previous studies agree in considering the presence of motor-evoked potentials (MEPs) in the first days after a stroke as an indicator of good outcome. In the present study, we have assessed the prognostic value of the absence of response to early TMS on hand motor recovery in stroke patients with complete hand palsy at onset due to ischemia in the area of the middle cerebral artery. METHODS: Fifteen patients submitted to TMS within 48 hours of stroke onset (defined as day 1) and again after 1 year. They were also evaluated clinically on day 1 by a scale derived from the Medical Research Council (MRC) and by the National Institutes of Health (NIH) stroke scale; they were reevaluated by the same scales and by Barthel Index on day 365. RESULTS: On day 1, all the patients had complete hand palsy and no response to TMS; their NIH scores showed great variability. After 1 year, 6 of 15 patients regained small and prolonged MEPs, together with a very poor and not functionally useful motor recovery. NIH scores were significantly improved. Barthel Index scores showed large interindividual differences and were not correlated with MRC scores. CONCLUSIONS: We conclude that in patients with complete hand palsy, the absence of response to TMS in the first hours is predictive of absent or very poor, not useful, hand motor recovery.
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Recovery curves of the R2 component of the blink reflex have been studied in 10 control subjects and 13 parkinsonian patients both after ipsilateral paired stimulation of the supraorbital nerve and after index finger stimulation. In control subjects, both types of conditioning induced a comparable marked inhibition lasting more than 600 ms. In parkinsonian patients, inhibition was reduced after both conditionings. However, differences appeared in the magnitude of the changes: after paired stimulation, it was less significant (ANOVA and post-hoc Duncan's test: p = 0.04) than after index finger stimulation (p = 0.002). In that latter situation, the more marked reduction in inhibition is interpreted, in the light of current physiologic knowledge, by hypoactivity of the Nucleus Reticularis Giganto Cellularis (NRGC) which would make less efficient inhibitory interneurones in the trigemino-facial pathway. The results are thus compatible with the suggestion that NRGC is made indirectly less active in Parkinson's disease.
BACKGROUND AND PURPOSE: We used transcranial magnetic stimulation of the motor cortex to evaluate the functional state of corticospinal pathways innervating the first dorsal interosseous muscle of the hand in 26 patients suffering from a first-ever ischemic stroke in the middle cerebral artery territory. METHODS: All patients had complete hand palsy and were tested within the first 24 hours from stroke onset. Patients were also tested clinically with the MRC, Rankin, and National Institutes of Health (NIH) stroke scales at day 1 and with MRC and NIH scales and the Barthel Index at day 14. Electrophysiological testing was repeated at day 14. Patients were divided into three subgroups according to the amplitude of the maximal response (motor evoked potential [MEP]) evoked at day 1. RESULTS: After 2 weeks, all 6 patients with initial MEPs > 5% maximum motor response (Mmax) showed some first dorsal interosseous muscle motor function recovery, whereas 19 of 20 patients with initially absent or small (< 5% Mmax) MEPs were left with complete hand palsy. There were strong positive correlations between MEP amplitude at day 1 and MRC and Barthel Index scores at day 14. However, measurement of central motor conduction time proved to be of little prognostic value. CONCLUSIONS: We conclude that early-performed transcranial magnetic stimulation is a valuable prognostic tool for motor recovery from stroke and that relatively preserved MEP amplitude shortly after stroke is a better prognostic factor than normal central motor conduction time.
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The potency of allergenic extracts can be determined in vitro by RAST inhibition, and this has become the preferred method for the standardization of allergens. A disadvantage of this technique is the impossibility of obtaining data about allergens bound to the solid phase, i.e., the counterpart of the inhibiting extract. The REAST (reverse enzyme allergosorbent test) is based on the capture of IgE by a specific antibody bound to microtiter wells, the reaction of captured IgE with biotinylated allergen and the development of a colour reaction by subsequent addition of streptavidin-peroxidase and chromogenic substrate. The addition of an allergen extract in a dose-response fashion competes with the biotinylated allergen and inhibits the test. In the present study REAST inhibition has been evaluated with Dermatophagoides pteronyssinus, Parietaria judaica and mixed grass pollen extracts. The correlation of REAST inhibition with RAST inhibition and both intra-assay and inter-assay reproducibility have been evaluated. REAST inhibition is a potentially valuable new tool for the standardization of allergenic extracts.
Local intranasal immunotherapy relieves the allergic symptoms of rhinitic patients but little is known about the absorption and distribution of inhaled allergens in the body. The aim of this study was to establish whether allergenic proteins are able to reach the bloodstream by penetrating through the nasal mucosa when aqueous P. judaica extract was administered into the nostrils of normal rabbits. Optimal conditions for a sensitive modified RAST (immunocapture RAST) were set up and the method was used to detect clinically relevant allergenic activity in the systemic circulation. The kinetic profile after intranasal treatment was compared with the profile after intravenous injection of the allergenic extract. The findings are discussed in relation to the mechanism by which local immunotherapy acts.
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