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Biomedical subjects

G Peretti

Publications and source records attributed to G Peretti.

At least 55 records · Page 3Linked to original sources

Experimental osteosarcoma in the mouse, induced by Moloney's murine sarcoma virus.

The writers report an experimental trial on the mouse, consisting in the induction of osteosarcoma by inoculation of Moloney's murine sarcoma virus (MSV-M) into the proximal metaphysis of the tibia. This experiment was conducted on 90 BALB/c female mice aged twenty-one days and of mean weight 12.8 g. One group of animals was also given immunodepressive drugs. The tumour developed in 100 per cent of cases, producing metastases in some of the animals and resulting in death in three cases. The radiographic changes were initially osteolytic followed later by new bone formation. The histological examinations confirmed that the tumour was of an osteosarcomatous nature. Cells characteristic of rhabdomyosarcoma were observed in the soft tissues surrounding the bone. The skeletal metastases had the characteristics of osteosarcoma, while those in the lymph glands and lungs had those of an undifferentiated sarcoma. The writers also took into consideration a series of previous trial performed at the Institute of Clinical Orthopaedics of the University of Milan, involving a total of 740 mice, in arriving at their final conclusion that MSV-M induces, in the mouse, an osteosarcoma similar to spontaneous osteosarcoma in man, capable of producing osteoid tissue, of giving rise to metastases, and of causing the death of the animal.

Animals↗

Experimental suture of the peripheral nerves with "fibrin glue".

An experiment on rats is presented, concerned with a technique for suturing peripheral nerves by means of "human fibrin glue". The sutures were performed by three different methods: (1) the traditional technique; (2) using a special grooved Vitallium plate (presented by the authors in a previous paper) by means of which all sutures can be dispensed with, and which facilitates more rapid and complete regeneration of the nerve; (3) with "fibrin glue", used on its own or together with the special plate. On comparing the three methods it was found that fibrin glue achieves better approximation of the nerve ends and thus leads to more rapid and more complete regeneration of the peripheral nerve fibres. Combined use with the plate is preferred where there is a minimal loss of nerve substance.

Animals↗

Larsen's syndrome. Case report and discussion.

The writers present the case of a small girl affected by Larsen's syndrome. Her brother had the same syndrome. Surgical reduction of the dislocated knees was performed at the age of two months, followed by immobilisation in a spica plaster. At operation it was found that both patellae, which are cartilaginous at that age, were absent. On the basis of recent literature and the heterogeneous manifestations of the syndrome, the authors discuss the pathogenetic theories, the differential diagnosis, and the current therapeutic possibilities.

Abnormalities, Multiple↗

Camptomelic syndrome. A rare type of congenital dwarfism associated with skeletal and other abnormalities.

Three cases of the rare camptomelic syndrome are presented observed within fourteen months at the Mangiagalli University Clinic, Milan. The radiographic appearances and clinical characteristics are described, and compared with the thirty five cases in the literature. The differential diagnosis is discussed and the possibility of diagnosing this malformation prenatally is suggested.

Abnormalities, Multiple↗

A study of the development of fracture callus in the presence of an experimentally induced osteosarcoma.

The results of two experiments are reported in which the formation of an osteosarcoma was induced in mice by the intraosseous injection of Moloney's virus. In the first group of fifty mice, a complete diaphyseal fracture was carried out nine days later at the site of the tumour. In the second group of 200 mice, a partial fracture was produced at the time of injection so that immobilisation was assured. The effects of cyclophosphamide and calcitonin administration were also studied in this group. The course of the repair processes of the bone was studied in both groups, and showed that, even in the presence of an osteosarcoma, these begin and can reach completion, though obstructed and delayed by the tumour.

Animals↗

Dynamic and static contributions to the rhythmic y activation of primary and secondary spindle endings in external intercostal muscle.

1. In cats anaesthetized with sodium pentobarbital 160 external intercostal muscle spindle afferents were identified by their pause in response to ventral root stimulation; the internal intercostal muscle was denervated. 2. In order to assignate the afferents to either primary or secondary endings they were tested for their responsiveness to vibration (Bianconi & Van Der Meulen, 1963). The maximal frequency which they were able to follow regularly for at least four cycles, termed 'critical frequency', was determined. 3. The endings fell into two groups: low-f (frequency) sensitive endings with critical frequencies below 400 c/s and high-f sensitive endings with critical frequencies above 400 c/s. The latter were regarded as primary endings and the former as secondary ones. 4. The manner in which the spindle endings resumed activity after a pause produced by shocks to the ventral root, i.e. whether 'phasic' or 'tonic' (Granit & Van Der Meulen, 1962) was studied in all the spindle afferents. 5. All the secondary (low-f sensitive) endings were 'tonic' except three for which the determination of critical frequency was questionable. Both 'tonic' and 'phasic' properties were found among the primary (high-f sensitive) endings. 6. The majority of the secondary endings (74%) showed inspiratory ythmic fusimotor activation in parallel with the skeletomotor contracton as did the primary endings (79 %). 7. Fifty-seven spindle endings which all showed marked rhythmic inspiratory gamma activation were tested for respiratory variations in their dynamic responses to steady stretch and length changes introduced at low repetition rates. 8. The results indicate that both 'dynamic' and 'static' gamma fibres are represented among the rhythmic gamma fibres controlling primary muscle spindle endings, whereas rhythmic activation of secondary endings seems to be mediated only by 'static' fibres.

Animals↗