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R Bombelli

Publications and source records attributed to R Bombelli.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Mechanics of the normal and osteoarthritic hip. A new perspective.

The mechanism of force transmission in normal and osteoarthritic human hips is interpreted with the aid of the following hypothesis: the essential anatomic requisite for the maintenance of mechanical equilibrium about the hip is a horizontal acetabular weight-bearing surface. Anatomic deviations from this norm result in a disequilibrium of opposing vector forces and may be contributory to the eventual onset of osteoarthritis (OA). The radiographic anatomy of the hip is the temporal record of the biologic response of bone to load transmission. From the analysis of radiographs the magnitude and direction of mechanical forces about the hip can be inferred. Deviations from normal, as in OA, can be understood by such radiographic analyses.

Adult↗
PubMedDate not supplied

Measurement of catecholamines in mouse bone marrow by means of HPLC with electrochemical detection.

BACKGROUND AND OBJECTIVE: Noradrenergic innervation is present in the bone marrow and adrenergic agents can modulate hematopoiesis. However, since no data are available concerning endogenous catecholamines at this level, we investigated their presence and origin. METHODS: Using a high performance liquid chromatographic method, we have and measured endogenous catecholamines in bone marrow from normal, 6-OHDA-treated and pargyline-treated mice. RESULTS: Noradrenaline, adrenaline and dopamine levels were, respectively, 2806.74 +/- 408.85, 803.37 +/- 87.66 and 274.47 +/- 51.54 pg/g of tissue. Noradrenaline levels were lower after 6-OHDA (1130.47 +/- 142.73 pg/g of tissue, p < 0.01 vs. control values) and higher after pargyline (4122.62 +/- 509.54 pg/g of tissue, p < 0.05). None of these treatments significantly affected adrenaline or dopamine content. INTERPRETATION AND CONCLUSIONS: Noradrenaline in the bone marrow originates mainly from sympathetic nerve endings and is metabolized through specific enzymatic pathways. Adrenaline and dopamine may originate from other sources, such as the systemic circulation.

Adrenergic Agents↗
PubMedDate not supplied

The biomechanics of the normal and dysplastic hip.

The author describes a simple method to highlight forces, by extrapolating on x-rays of normal and dysplastic hips the direction of the skeletal lamellae of the pelvis and that of the proximal femoral metaepiphysis. In the pelvis is described a tridimensional structure, made of two basic lamellar systems: one that begins from the "lamina quadrilatera" and one from the lateral border of the "sourcil." They move in the opposite direction: the first towards the Waldayer tuberosity, the anterosuperior and inferior iliac spine; the second towards the sacroiliac joint. They form a structure similar in shape to an hourglass, the inferior cone of which underlines the "sourcil" and looks like a Gothic arch. In the normal hip the "sourcil" is slightly oblique (3-4 degrees) in bipodalic support. It becomes horizontal in monopodalic support. From the direction of the lamellae of the Gothic arch the author obtains the direction of the forces acting in the static and dynamic phase of the normal hip. In the dysplastic hip the "sourcil" may be oblique in an anterocraniolateral or posterocraniomedial direction. Consequently, the lamellae of the hour-glass and of the Gothic arch undergo a different orientation. From these altered orientations the author visualizes the direction of the pathologic forces. Based on the shape of the Gothic arch and of the angle of inclination of the femoral neck the author describes the forces acting on the pelvis and on the femoral head when there is either valgus or varus in the neck; according to the degrees of inclination of the femoral neck he describes the variation of magnitude of loading on the support surfaces.

Biomechanical Phenomena↗