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Biomedical subjects

M Martini

Publications and source records attributed to M Martini.

At least 145 records · Page 8Linked to original sources
PubMed1986

Some hydrodynamic properties of the posterior canal in the frog labyrinth related to neuronal responses.

Measurements of the posterior-canal radius of curvature (R), the semicircular-duct radius (r) and the cupula radius (rC) were performed in the frog labyrinth. The Steinhausen-van Egmond equation led to an estimate of the canal endolymph flow, cupula deflection and sensory hair bending during constant angular accelerations (0.2-64 degrees/s2) of opposite directions and increasing duration (1.2-12 s). This analysis suggests that the non-linear canal afferent discharge behaviour exhibited by some units may not arise at the presynaptic level but rather postsynaptically, at the encoder site.

Acceleration↗
PubMed1986

Afferent activity recorded during rotation from single fibres of the posterior nerve in the isolated frog labyrinth.

EPSPs and spikes were recorded at rest and during rotation from single fibres of the posterior nerve in the isolated frog labyrinth. The spike discharge properties of 57 units were examined at rest and during repetitive acceleratory-velocity steps. Forty of these units were subjected to excitatory steps of 5-12 s duration and 45% displayed an evident discharge adaptation. In the non-adapting units, the excitatory response also deviated from that expected on the basis of the torsion-pendulum model and exhibited an exponential time-course in only 36% of the fibres examined. The time constant T2 of the response rising phase was significantly longer than that of the decay (2.5 s versus 1.7 s). When all the 57 units were considered, a linear behaviour was found in 67%. The average gain in these linear units was 1.9 +/- 1.4 spikes X s-1/deg X s-1. Adaptive fibres exhibited a lower resting firing rate and a higher gain (3.8 spikes/s and 2.3 spikes X s-1/deg X s-2, respectively) when compared with the non-adapting ones (7.1 spikes/s and 1.5 spikes X s-1/deg X s-2). An undershoot was present in 57% of the units; it increased with acceleration and was not strictly related to adaptation. Fifteen of the 40 units tested with the 5-12 s duration excitatory steps survived repeated inhibitory accelerations of the same duration. In these units a marked response asymmetry was evident since their resting activity could be abolished by accelerations not larger than 10 deg/s2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Tuberculous osteomyelitis. A review of 125 cases.

One hundred and twenty-five cases of tuberculous osteomyelitis have been observed by the authors since 1968. The site of the lesion and the clinical and radiological findings have been analysed. The importance of accurate diagnosis by bacteriological and histological investigation is emphasized. Pitfalls in the differential diagnosis with chronic haematogenous osteomyelitis are described. Treatment is by chemotherapy, and immobilization is useless. Operation was limited to the drainage of three large abscesses. A favourable response to chemotherapy was obtained in 92% of the 105 cases which were followed up. The role of a super-added pyogenic bone infection in 8 cases of persisting sinus after chemotherapy is discussed. Finally, the authors stress the importance of preventing the development of tuberculous arthritis by the correct diagnosis and treatment of juxta-articular tuberculous osteomyelitis.

Adolescent↗
PubMed1986

Tuberculosis of the upper limb joints.

Seventy-four cases of tuberculosis of the upper limb joints (sterno-clavicular 1; shoulder 12; elbow 42; wrist 10 and fingers 9), treated by two of the authors, were reviewed. Eighty-seven percent presented at an advanced stage of destruction. The diagnosis was proved in 71 our of 74 cases. In most, the treatment was 6-12 months of chemotherapy, plaster immobilization (in order to prevent or correct deformity) and functional rehabilitation whenever possible. The sterno-clavicular and finger joints were not immobilized. Response to chemotherapy was favourable in 66 of the patients followed up. One relapse occurred at the 18th month. The affected shoulder joints healed with loss of movement, but were not painful. At the elbow, ten patients developed spontaneous bony fusion in the right-angle position, 27 had a useful range of motion and 19 had more than 70 degrees of flexion-extension movement. One patient had an arthrodesis. At the wrist, two patients healed with painful stiffness and an arthrodesis was performed. All the finger lesions healed with painless stiffness which did not interfere much with function because rehabilitation had been started early. The authors believe that conservative management usually gives better results than arthrodesis or excision of the joint.

Adult↗
PubMed1986

Quantitative evaluation of Leydig cells in testicular biopsies of men with varicocele.

A quantitative analysis of Leydig cells was performed in 23 testicular biopsies of men with left varicocele and sperm count ranging from zero to 95,000 sperm/mm3. The oligozoospermic patients had more Leydig cells and higher FSH and LH serum levels than the patient group with more than 10,000 sperm/mm3. The Leydig cell density appeared tightly correlated (p less than 0.01) with the serum level of LH. In oligozoospermic subjects, an altered Leydig cell function could trigger an increased LH secretion; this seems likely to be responsible for the stimulation of interstitial cells resulting in an exaggerated recruitment of mature Leydig cells from their precursors. The comparative analysis of left and right testes failed to show differences in Leydig cell density and spermatogenesis in normozoospermic and oligozoospermic patients. This suggests that the two testes are equally involved by a possible, although unknown, detrimental effect of left side varicocele.

Adult↗
PubMed1986

[Lymphocyte subpopulations in alopecia areata].

Subsets of peripheral blood lymphocytes were studied in 19 patients with alopecia areata. The results shows: a decreased Tm/Tg ratio, decreased number of OKT4+ cells, increased OKT8+ cells, decreased OKT4+/OKT8+ cell ratio. Total lymphocytes, T cells, Tm cells, Tg cells, T DR+ cells and B lymphocytes were normal. The results are similar to those founded in autoimmune diseases and suggest the existence of an immunopathogenic mechanism in these disease.

Adolescent↗
PubMed1985

[Modulating action of barium and other ions on the sensory activity of frog labyrinth].

The effect of Ba2+, TEA, 4-AP and CoCl2 on the EPSP and spike discharges recorded from single fibres of the posterior nerve in the isolated frog labyrinth has been investigated. In Ca-free solution Ba2+ preserved, at low concentration (0.3 mM), the resting activity and at higher levels (up to 6 mM) it resulted in a pronounced facilitation of the EPSP and spike discharges. Facilitation increased on increasing Ba2+ concentration up to 4-5 mM and it was more evident in those units exhibiting a low resting spike firing. The effect of Ba2+ (1 mM) was completely antagonized by 10 mM Ca2+ X CoCl2 (3 mM) suppressed the resting rate at the normal external Ca2+ concentration; the Co2+ block was partially relieved by 1.8 mM Ba2+ X TEA (20 mM) evoked a clear-cut increase in the EPSP and spike discharges which, however, was less consistent than that produced by Ba2+. By comparing the effect of TEA on the spike frequency with that obtained at different Ba2+ levels, the Ba2+ capacity to carry the Ca2+ current was dissected. Such an effect is dose-dependent and it is more evident in low-frequency units. Conversely, 4-AP did not affect the resting discharge frequency. These results indicate that either the Ca2+ or the Ba2+ current sustain the transmitter release at the cyto-neural junction. The effect of TEA suggests that the Ca2+-dependent K+ current may play an important role in supporting the neurosecretory process by controlling the membrane potential of the hair cells.

4-Aminopyridine↗
PubMed1985

Tuberculosis of the knee.

Ninety-eight cases of tuberculosis of the knee (85 adults and 13 children), treated by one or other of the authors, were reviewed. 70% of the patients presented an advanced stage of destructive disease, but 30% were seen at the stage of synovitis. A proven diagnosis was obtained in 88 out of 98 cases. In the majority, treatment was standardised with 6 to 12 months of chemotherapy and plaster immobilisation in order to prevent or correct a deformity. Arthrodesis was only undertaken for disabling deformity after conservative management (16 cases). Response to chemotherapy was favourable in 78 followed-up patients. Five relapses occurred between the 12th and 24th month. The functional results ranged from full normal recovery to spontaneous fusion or arthrodesis. The results were related to the stage of the disease at the time when treatment was started.

Adolescent↗
PubMed1985

[Conservative treatment of osteoarticular tuberculosis of the elbow].

Thirty-six cases of tuberculosis of the elbow have been treated by chemotherapy and plaster cast immobilisation followed by rehabilitation. The overall results were satisfactory with restoration of useful mobility and flexion in 26 cases. The ranges of movement in pronation and supination were less satisfactory.

Adult↗
PubMed1984

[Physical dimensions influence the functional property of the semicircular canal].

The functional dependence of the semicircular canal upon its physical dimensions was evaluated by measuring the internal radius (r), the radius of curvature (R) and the cupula radius (rC) of the posterior canal in 10 freshly dissected frog labyrinths. These values have been compared to the same parameters of the cat labyrinth. The coefficients I, B, K in the Steinhausen equation were determined for both animals. The A ratio between cupula deflection and endolymph displacement was also calculated by utilizing the Bernard equation. The A ratio is three times larger in the frog than in the cat. It follows that if the same acceleration produces similar endolymph displacements in the posterior canal of both animals, the cupula deflection will be larger in the frog. The solution of the Steinhausen equation in the presence of a constant acceleration, however, reveals that the same stimulus intensity will result in a larger endolymph displacement in the cat posterior canal; similarly, the endolymph displacement directly depends on the duration of the stimulating period in both animals. Contrary to the Bernard assumption, these effects generate a G ratio (psi frog/psi cat) which is less than the Q ratio (A frog/A cat). Moreover, G decreases on increasing the duration of the stimulating period. For stimuli of short duration the semicircular canal of a small animal is expected to exhibit a higher sensitivity than that of a larger one. However, the definitive primary afferent discharge will be largely controlled by the receptor/generator potential properties.

Acoustic Stimulation↗
PubMed1984

[Tuberculous osteoarthritis of the foot and ankle joint].

The authors have reviewed 26 cases of tuberculosis of the foot and 32 of the ankle, which they have treated personally. All the patients were adults and most presented with advanced destruction of bone and joints. Bacterial and histological confirmation of the diagnosis was obtained in 56 patients. All were treated by chemotherapy; the drugs and regime varied over the years. All responded well to this treatment, but one relapsed after 24 months. Orthopaedic problems were usually managed by immobilisation in plaster casts, but 6 patients required arthrodesis, 5 of the ankle and one triple fusion. The functional results of the standard treatment were generally good. Arthrodesis is seldom needed and should be performed only for permanent pain or crippling deformity.

Adolescent↗
PubMed1984

[Neglected luxations of the elbow. 25 surgical reductions].

During the past 8 years the authors have seen 47 old dislocations of the elbow. In 16 instances, function was acceptable with more than 90 degrees flexion and in 31 it was not acceptable. Twenty five elbows were operated on with 23 satisfactory results and 2 stiff elbows. The importance of long-term rehabilitation is stressed. Reduction achieved a better position of the elbow but only slight improvement in the range of movement. The need for surgical reduction should only be considered after several months of rehabilitation since some older cases can be improved without surgery. More recent cases should be operated on as soon as possible.

Adult↗
PubMed1982

[Arrest of maturation in spermatogenesis].

The ultrastructural aspects of the germinal epithelium of 10 infertile men affected by maturative arrest of spermatogenesis were studied. We noted an increased number of malformed germinal cells. Marginal nuclear vescicles were present in spermatogonia of patients affected by spermatogonial arrest. The few spermatid present in the germinal epithelium of the patients affected by a spermatidic arrest presented changes of the nuclear condensation, the acrosome, and the tail. The Sertoli cells presented an immature aspect of the nucleus and changes of the "mantle". A possible correlation between the Sertoli cells changes and the altered spermatogenesis was proposed.

Humans↗