Search PubMed⌕ Search

Biomedical subjects

R Marini

Publications and source records attributed to R Marini.

At least 55 records · Page 3Linked to original sources
PubMed1984

Immunohistochemical localization of fibronectin in structures of the human oral cavity: dental pulp and gingiva.

The distribution of fibronectin (FN) in the dental pulp and gingiva of the human adult was investigated by indirect immunofluorescence and indirect immunoperoxidase techniques. FN could not be demonstrated in the connective tissue of the dental pulp even in the blood vessels. On the contrary, a positive stain was obtained in the ground substance at the base of the odontoblast cell bodies and in various structures of a denticle which was accidentally found in the pulp of one of the examined teeth. The lack of FN in the dental pulp could mean that this tissue, sometimes considered to be of an immature and undifferentiated type, is instead a mature one. The subepithelial connective tissue and the epithelium of the gingiva were examined. The distribution of FN in the connective tissue of the gingiva was found to be similar to that described in other types of connective tissue; high concentrations were found both in the epithelial cells and around them. This finding is described here for the first time and remains to be verified in other types of stratified epithelia.

Dental Pulp↗
PubMed1983

Acromesomelic dwarfism in a child with an interesting family history.

Acromesomelic dwarfism is a rare skeletal disorder characterized by recessive autosomal transmission. A case is described in a boy 2 1/2 years old whose relatives (in a large number) showed a peculiar aspect of the upper extremities, and whose two grandparents were second cousins. Early diagnosis is important because it makes it possible to advise the parents with regard to the infant's prospects and the genetic implication.

Abnormalities, Multiple↗
PubMed1982

A somatotopic and functional organization of the masticatory proprioceptors in the mesencephalic trigeminal nucleus of the frog.

A stratified organization of the first-order neurons of the masticatory proprioception has been observed in the frog mesencephalic trigeminal nucleus (MeNV). Extracellular records of unit activity have shown that in this nucleus neurons responding either to jaw raising muscles or to jaw lowering muscles reveal a somatotopy. A consistent topography pattern is evident by exploring in dorsoventral direction the layers 4 and 6 in the optic tectum. The jaw closing muscles are represented in the dorsal part of the MeNV, whereas the jaw opening ones are distributed more ventrally. Since MeNV neurons represents the afferent limb of the masticatory reflex, the motor effects elicited by electrical stimulation of these cells have been tested.

Afferent Pathways↗
PubMed1981

[Preliminary observations on the existing relationship between plasma levels of prolactin and hypophyseal reserves of FSH and LH in the male].

PRL plasma levels and FSH and LH pituitary reserve were tested in ten apparently healthy male subjects. A good correlation was found between PRL on one hand and FSH plasma levels (p less than 0,05), LH plasma levels (p less than 0,01) and FSH pituitary reserve (p less than 0,01) on the other hand. This seems to support the current hypothesis that prolactin may cause a progressive clinically latent impairment in the spermatogenetic function of the testis. Further evidence is needed.

Adult↗
PubMed1981

[Relationship between benign breast cancer and plasma levels of prolactin].

Prolactin (PRL) plasma levels were measured in the follicular phase of the cycle in 75 normally menstruating women divided into three groups: group I was normal (n. = 39), group II showed benign breast disease (n. = 26), group III hyperandrogenism (n. = 10). PRL levels were higher (670,8 +/- 61,2 microunits/ml) in the second group than in the first (216,0 +/- 12,0 microunits/ml; p less than 0,001) and in the third group (426,0 +/- 75,2 microunits/ml; p less than 0,02). Two mechanisms are hypothesized as a possible explanation for the results: a) hyperprolactinemia primarily alters progesterone/oestradiol ratio which secondarily initiates benign breast disease, or b) relative hyperestrogenism causes an increase in PRL plasma levels, which, in turn, interact with oestradiol to give mammary gland hypertrophy. Further studies are needed in order to elucidate the problem.

Adolescent↗
PubMed1979

Proximal limb movements in response to microstimulation of primate dentate and interpositus nuclei mediated by brain-stem structures.

The cerebellar dentate and interpositus nuclei and the area of their efferent fibres have been stimulated in Cebus monkeys, using a movable microcathode. Responses consisted of eye and face movements and a stereotyped flexion of proximal parts of extremities. Very few distal limb movements were seen. The activation of proximal muscles was studied most closely. It consisted of the limited number of 5 movements: arm flexion and shoulder elevation in the forelimb and hip flexion, knee flexion and dorsiflexion of the ankle in the hindlimb. With currents of up to 100 microamperemeter these movements were elicited more readily from the interpositus and the area of efferent fibres of both nuclei as compared to the dentate nucleus. Responses were more often seen in forelimb than in hindlimb muscles, without apparent somatotopy in either nucleus. Combined forelimb-hindlimb movements were elicited from 42 per cent of effective points. Lesions placed at various locations of cerebellar output pathways demonstrated that the responses were mediated by the descending branch of brachium conjunctivum and did not require the activation of structures anterior to and including the red nucleus. The responses are interpreted to represent adjustments in flexor posture that may serve to modify maintained antigravity tonus during the initiation of volitional movements. This function, mediated by brain-stem structures, is considered to be closely associated with the activity of the lateral and intermediate cerebellum during initiation and conduction of volitional movements, which is mediated mainly through the cerebral cortex. It is stressed that control over both flexor posture and discrete distal movements is inherent in the initiation of voluntary movements.

Animals↗
PubMed1979

Somatotopic organization of second order neurons of the eye muscle proprioception.

Unit activity was recorded extracellularly from lamb's nucleus principalis and pars oralis of trigeminal nuclear complex following moderate manual stretching of individual extraocular muscles. The oral portion of the spinal trigeminal nucleus and the main sensory nucleus have been investigated by systematic exploration of the second-order neurons of the eye muscle proprioception. Such responses were somatotopically organized. In particular, each single extraocular muscle was represented along the main dorso-ventral axis in this manner: superior oblique and superior rectus in a dorsal layer; inferior rectus and inferior oblique in an intermediate layer, while the medial rectus and the lateral rectus were represented more ventrally. In a few experiments this representation was not observed, due to intermingling of the units. The topographic organization of eye muscle proprioception in the trigeminal nuclear complex described above closely corresponds to that reported by previous authors in the Gasser ganglion.

Animals↗
PubMed1977

Integration of cerebral and peripheral inputs by interpositus neurons in monkey.

The patterns of convergence of cerebral and peripheral nerve inputs onto interpositus neurons were studied in cebus monkeys. The strongest inputs to interpositus neurons are from motor and somatosensory cortex, with weaker inputs from peripheral nerves and cerebral area 6. The neurons in the anterior portion of interpositus receive cerebral and peripheral inputs primarily representing the hindlimb, while inputs to neurons in the posterior division represent forelimb or mixed forelimb and hindlimb. The hindlimb neurons integrate signals principally from motor cortex, somatosensory cortex, nerves, supplementary motor and medial pre-motor areas, while forelimb neurons receive inputs from motor, somatosensory, lateral premotor cortical areas and nerves. The results from this study are compared with those from studies of interpositus and dentate neurons in cat and monkey in order to determine the role of n. interpositus in movement. It is suggested that the inputs integrated by interpositus neurons are consistent with a role in up-dating skilled movements.

Action Potentials↗