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Biomedical subjects

M Avella

Publications and source records attributed to M Avella.

At least 19 recordsLinked to original sources
PubMed1995

Comparison of the hepatic uptake and processing of cholesterol from chylomicrons of different fatty acid composition in the rat in vivo.

The effect of the fatty acid composition of chylomicrons on the uptake and processing of the cholesterol they carry was investigated in the rat in vivo. Rats kept on a standard low fat pellet diet and tube fed a single dose of palm, olive, corn or fish oil (rich in saturated, n-9 monounsaturated, n-6 polyunsaturated and n-3 polyunsaturated fatty acids, respectively) were used to prepare [3H]cholesterol-labelled chylomicrons of different fatty acid composition. These were then injected intravenously into rats (kept on the standard diet), and the clearance of radioactivity from the blood, distribution in the plasma lipoprotein density fractions, uptake by the liver and appearance in the bile were studied. [3H]Cholesterol from fish and corn oil chylomicrons was cleared from the blood more rapidly than that from palm and olive oil chylomicrons. After 180 min the proportion of the radioactivity present in the plasma in high density lipoprotein (HDL) was less when the chylomicrons were derived from palm oil as compared to any of the other oils. Approx. 40% of the administered label was recovered in the liver after 180 min in all experiments. The percentage of the injected radioactivity secreted into bile during 180 min was significantly higher with corn and fish oil chylomicrons than with palm oil chylomicrons, with chylomicrons from olive oil in an intermediate position, and these differences were most pronounced between 60 and 120 min after administration of the label. These studies clearly demonstrate that the fatty acid composition of chylomicrons has important effects on the hepatic uptake and processing of the cholesterol they carry, with enrichment with polyunsaturated fatty acids leading to an increased rate of uptake and more rapid removal from the body via the bile as compared to enrichment with saturated or monounsaturated fatty acids.

Adrenal Glands↗
PubMed1994

Primary culture of gill epithelial cells from the sea bass Dicentrarchus labrax.

We have developed the first explant technique that allows the in vitro study of gill physiology and biochemistry in marine species. Gill fragments were cultured at 17 degrees C, in atmospheric PCO2, with nutrient medium (Leibovitz L15), pH 7.8, supplemented with 10% fetal bovine serum and adjusted to the osmolarity of fish plasma (350 mOsm/liter). Coating plates with collagen, gelatin, or polylysin did not improve our results. Decrease in osmotic pressure, removal of bovine serum, or its replacement by fish serum inhibited growth from the explants. Approximately 50% of the explants produced cell growth, and after 4 days of culture a monolayer of contiguous cells was formed. This technique is rapid and does not require the use of enzymes. The cells appeared flat and thin with an epitheloid shape. They looked polygonal with a maximum length of 10 to 50 microm. Evidence that they are unique gill cells is the presence of polymorphic surface crenelations (microplicae), prominent Golgi apparatus, tight junctions and desmosomes. Comparison with in vivo tissue showed them to be epithelial cells having differentiated in a homogeneous population of respiratory-like (pavement) cells. They are polarized with their apical surface facing the culture medium. The development of this culture system represents a new tool for cellular approaches to determine precisely the functions and transport mechanism of gill cells.

Animals↗
PubMed1993

Osteoporosis by ovariectomy: calcitonin effect in an experimental model on the rat.

The authors evaluate the efficacy of the aminosuberic derivative of eel calcitonin (eCT) in preventing post-ovariectomy osteoporosis in adult rats. The drug is administered in a dose of 0.5 U.I./day for four months starting from the moment of the ovariectomy. The results show that the treatment is efficacious in preventing bone mass loss due to ovariectomy and that the action of the drug does not bring about alterations in the normal crystalline structure of the bone.

Alkaline Phosphatase↗
PubMed1993

[Osteosarcoma of the extremities metastatic at presentation. Results obtained with primary chemotherapy followed by simultaneous resection of the primary and metastatic lesion].

From September 1986 to September 1990 35 patients affected by osteosarcoma of the extremities with synchronous metastasis were treated with two cycles of high-dose methotrexate IV, cisplatin IA and adriamycin IV followed, in 22, by simultaneous resection of the primary and metastatic tumor. Six patients progressed and were not operated on, 7 patients with complete response of pulmonary nodules underwent surgical resection of the primary lesion. A complete histological examination of the resected specimens was always performed to evaluate the percentage of necrosis produced by chemotherapy on both the primary and metastatic tumor. After surgery the patients received 3 more cycles of the same drugs as used preoperatively plus ifosfamide. The histological response of the primary tumour was "good" (90% or more tumour necrosis) in 8 patients (27%) and "poor" (less than 90% of tumour necrosis) in 21 (73%) while in the 75 metastatic nodules the resulting necrosis was good in 18 (24%) and poor in 57 (74%). A good correlation between the histological response in the primary and metastatic tumour was observed. At an average follow-up of 30 months (R 12-60), 13 patients are alive, 10 disease-free, and 3 with uncontrolled disease. This data suggest that prognosis of osteosarcoma of the extremities with synchronous metastases remains poor even with a very aggressive treatment. Our results also seem to confirm the validity of the present strategy in the treatment of non metastatic osteosarcoma: to introduce new drugs postoperatively in patients poor responder can allows a better treatment of microscopic disease and can improve the prognosis for these patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

[Effect of high and low doses of methotrexate (MTX) on bone mass in subjects treated for osteosarcoma of the limbs].

Twenty-three patients with highly malignant localized osteosarcoma receiving neoadjuvant chemotherapy with MTX randomly administered at high (7500 mg/m2) and low (750 mg/m2) doses underwent serial densitometric controls at the start of treatment and after 18 and 36 months. Increasing BMC levels at both examination points were observed in all subjects examined over time, but, contrary to findings in the control group, this increase was not statistically significant using the paired T test. Significantly lower BMC levels in relation to the control group were only found in the group treated with high doses of MTX at MDP but not PM. Reduced density at MDP alone, a site in which trabecular bone is prevalent, shows that MTX predominantly acts at the level of the latter in line with its greater sensitivity to the action of osteopenic agents.

Adolescent↗
PubMed1992

Osteosarcoma of the extremity metastatic at presentation: results achieved in 26 patients treated with combined therapy (primary chemotherapy followed by simultaneous resection of the primary and metastatic lesions).

From September 1986 to December 1989, 26 selected patients with high-grade osteosarcoma of the extremities metastatic at presentation were treated with primary chemotherapy (high doses of methotrexate, -cisplatinum and adriamycin) followed by surgery. Twenty-one cases underwent resections of the primary and metastatic tumor at the same time; owing to the disappearance of lung metastases after preoperative chemotherapy in 3 cases, only the primary tumor was operated on. Due to progression of the disease in 2 patients, no surgery was performed. Histologic examination of the resected specimen was performed to evaluate the percentage of necrosis produced by chemotherapy on the primary and metastatic tumor. After surgery, the patients received further chemotherapy with the same drugs used preoperatively plus ifosfamide and VP-16. The histologic response of the primary tumor was good (> 90% tumor necrosis) in 25% of the cases; in the resected metastatic nodules, 23% had good responses. A discrepancy between the histologic response of the primary and secondary tumor was observed in only 15% of the cases. These results seem to confirm the validity of the strategy (widely used today in the neoadjuvant treatment of non-metastatic osteosarcoma) of changing the postoperative treatment when the histologic response of the primary tumor is poor. At an average follow-up of 3.5 years, only 6 patients remained disease-free; 19 patients relapsed and 1 patient died for adriamycin cardiotoxicity. Of the 19 relapsed patients, 16 died and 3 are still alive but with uncontrolled disease. These results are much worse than those obtained in 144 cases of non-metastatic osteosarcoma of the extremities treated in the same period with the same preoperative chemotherapy (77% with good response in the primary tumor and 78% with continuous disease-free survival). The data suggest that a very effective neoadjuvant chemotherapy for nonmetastatic osteosarcoma of the extremities gives disappointing results in osteosarcoma of the extremities which is metastatic at presentation.

Adolescent↗
PubMed1992

Effects of starvation on valine and alanine transport across the intestinal mucosal border in sea bass, Dicentrarchus labrax.

Kinetics of intestinal transport of L-alanine and L-valine (substrates of the A-system and the L-system, respectively, in mammals) across the brush-border membrane in sea bass, Dicentrarchus labrax, were studied on intact mucosa using a short-term uptake technique. When fish were starved for 4-8 weeks, total influx (mucosa-to-cell) of valine fell owing to disappearance or modification of the diffusion component. The maximum influx rate of saturable component increased but its affinity (reflected by the Michaelis constant) decreased. Alanine transport by Na(+)-dependent and diffusion pathways was unchanged after starvation. Fasting also induced an almost 20% decrease in the length of intestinal microvilli.

Alanine↗
PubMed1992

Effect of intra-arterial versus intravenous cisplatin in addition to systemic adriamycin and high-dose methotrexate on histologic tumor response of osteosarcoma of the extremities.

In neoadjuvant treatment of osteosarcoma of the extremities intra-arterial (IA) instead of intravenous (IV) administration of cisplatinum (CDDP) has been advocated to improve local response and consequently increase the percentage of limb salvages and the cure rate. Since the major local advantages from the IA use of CDDP have been recently questioned, a comparative prospective study was performed at the Rizzoli Institute between July 1990 and September 1991. Preoperative chemotherapy consisted of two cycles of high-dose methotrexate (HDMTX), followed 6 days later by CDDP and adriamycin (ADM), HDMTX and ADM were delivered intravenously while CDDP was delivered according to previous randomization, either intra-arterially or intravenously. Of the 79 patients who entered the study 40 received CDDP IA and 39 CDDP IV. The percentage of clinical and radiological response of the tumor as well as the percentage of limb salvage procedures performed was the same in the two groups. However the rate of good histological response (tumor necrosis greater than 90%) was significantly higher in the group of patients who received IA CDDP than in the patients who received the drug intravenously (77.5% vs 46%: p less than 0.01). No differences in terms of local or systemic side effects were found in the two groups. A longer follow-up is necessary to establish if this improved good response rate achieved with IA CDDP will lead to an improved cure rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Primary chemotherapy and delayed surgery for osteosarcoma of the extremities with synchronous metastases.

From September 1986 to September 1989 11 patients affected by osteosarcoma of the extremities with synchronous metastases were treated with two cycles of high-dose methotrexate i.v., cisplatin i.a. and adriamycin i.v. followed by simultaneous resection of the primary and metastatic tumor. A complete histological examination of the resected specimens was always performed to evaluate the percentage of necrosis produced by chemotherapy on both the primary and metastatic tumor. After surgery the patients received 3 more cycles of the same drugs as used preoperatively plus ifosfamide. The histological response of the primary tumor was 'good' (90% or more tumor necrosis) in 4 patients and 'poor' (less than 90% of tumor necrosis) in 7, while in the 34 metastatic nodules the resulting necrosis was good in 8 and poor in 26. A good correlation between the histological response in the primary and metastatic tumor was observed, particularly for poor responders (91% of poor responses also in metastatic nodules). At an average follow-up of 42 months, only 3 patients are alive, 2 disease-free, and one with uncontrolled disease. These data suggest that the prognosis of osteosarcoma of the extremities with synchronous metastases remains poor, even with a very aggressive treatment. Our results also seem to confirm the validity of the present strategy in the treatment of non-metastatic osteosarcoma: introducing new drugs post-operatively in poor responding patients can allow a better treatment of microscopic disease and can improve the prognosis for these patients.

Adolescent↗
PubMed1992

[Effects of hydration on plasma concentrations of methotrexate in patients with osteosarcoma treated with high doses of methotrexate].

High dose of methotrexate (HDMTX) with leucovorin rescue requires over-hydratation to avoid nephrotoxicity; nevertheless the relationship between hydratation and plasma MTX levels is unknown. We compared the effects of two different types of hydratation (2 lt/m2 vs 1.5 lt/m2) on plasma MTX levels in two groups of patients with osteosarcoma of the extremities and treated with HDMTX (8 g/m2 IV). Samples were obtained at the end of infusion of MTX and 14 and 38 hours after the start of MTX infusion. At the end of infusion of MTX the medium plasma MTX levels proved significantly higher in the group with low hydratation than in the group with high hydratation (585.5 microns/l vs 427.7 microns/l P less than 0.001). The values obtained at 14 and 38 hours, did not show significant differences. No significant differences were seen between the two groups in term of late elimination of MTX and correlated toxicity. These data show that a low hydratation regime allows higher plasma MTX levels at the end of infusion of HDMTX and does not increase the incidence of late elimination of MTX compared to a high hydratation regime.

Adult↗
PubMed1991

Measurement of branchial vascular space of trout, Oncorhynchus mykiss: effects of adrenaline.

Using the isolated-perfused head preparation at a constant flow rate, hemodynamic effects of adrenaline were studied in trout gills. The calculation of the vascular spaces was performed with the isotopic pulse technique allowing measurement of the distribution space of the tracer. The results show that the branchial arterial circuit was cleared more quickly than the branchial venous and cephalic circuits. Adrenaline addition significantly increased the volume of the branchial arterial circuit at the expense of the venous circuit, illustrating the closing of arterio-venous sphincters under catecholamine control. The increase of the arterial volume could be explained by a vasodilation of the arterial circuit, rather than resulting from lamellar recruitment. Furthermore, the flow rate of the cephalic circuit represented 5% of the total branchial flow rate.

Animals↗
PubMed1991

Plasma prolactin and cortisol concentrations of stressed coho salmon, Oncorhynchus kisutch, in fresh water or salt water.

Juvenile coho salmon, Oncorhynchus kisutch, adapted to fresh water or seawater were either acutely handled or continuously stressed by severe confinement. Chronic stress, independent of external salinity, caused a gradual increase in the concentration of circulating prolactin that persisted for 1 to 5 days but lagged behind the cortisol response which peaked much more rapidly and remained elevated. Acutely stressed fish showed a rapid, more transient increase in plasma cortisol titer with no apparent effect on prolactin. Confinement appeared to be more stressful to fish in salt water than to those in fresh water, as judged by their sodium regulatory ability, hormone profiles, and mortality. Stress always elevated plasma prolactin concentrations, regardless of medium or developmental stage.

Animals↗
PubMed1991

Primary lymphoma of bone: long term results in patients treated with vincristine--adriamycin--cyclophosphamide and local radiation.

Primary lymphoma of bone (PLB) is an unusual but well-recognized extranodal presentation of non-Hodgkin's lymphoma. In most series treatment with radiotherapy alone results in a cure rate of approximately 40%. Between January 1972 and December 1982, 26 patients with biopsy proven PLB were treated at the Rizzoli Institute with radiotherapy (4000-5,500 rad) and chemotherapy (vincristine, cyclophosphamide and adriamycin). The minimal clinical staging included complete blood cell counts and serum chemistries, bone radiography, full lung tomography, isotope bone scan, bone marrow biopsy and bipedal lymphoangiograms. At a median follow-up of 13 years (8.5-18.5) there were only three relapses (2 cases of meningeal involvement and 1 recurrence in another bone). No local recurrences nor second tumor in the irradiated field were observed. We conclude that the addition of chemotherapy to radiotherapy results in an excellent cure rate for patients with PLB.

Adolescent↗
PubMed1991

[Ultrasound in the diagnosis of fragilitas ossium].

Recently, a proposal has been made to evaluate bone fragility in osteoporotic women by measuring ultrasound transmission velocity at the patella. Theoretically, sound transmission velocity depends on both bone mass and other factors which are not mass-dependent--e.g. bone architecture. Ultrasound transmission technique was thus tested for the capability of evaluating bone fragility factors, which are not mass-dependent, in the screening of osteoporotic women. To this purpose, the sound velocity at the patella of 31 healthy women was compared with that of 62 osteoporotic women with spontaneous vertebral fractures having similar bone mineral content. In 31 cases bone mineral content was similar to that of healthy women at the middle radius, and in 31 at the distal radius. Sound transmission velocity was significantly lower in osteoporotic than in healthy women. Fifty-two per cent of healthy women was correctly selected by US, relative to the risk threshold, versus 13% with bone mineral densitometry. This finding suggests that US is capable of distinguishing normal from osteoporotic women having similar bone mineral content, which means that non-mass-dependent factors may affect US velocity in the bone. Since the measurement were taken in various sites, different for US and bone densitometry, our results need confirmation in further studies where measurements are taken in the same sites.

Bone Density↗
PubMed1991

Non-metastatic Ewing's sarcoma: results in 98 patients treated with neoadjuvant chemotherapy.

From June 1983 to December 1987, 98 patients with non-metastatic Ewing's sarcoma of bone were treated by a protocol of neoadjuvant chemotherapy consisting of two months of preoperative chemotherapy with vincristine, adriamycin, and cyclophosphamide followed by local treatment and one year of chemotherapy aimed at preventing recurrence using the same drugs plus dactinomycin. Local treatment consisted of surgery in 39 cases (40%), radiation in 34 (34%), and both surgery and radiation in 25 (26%). After an average follow-up of five years, 51 patients (52%) had remained continuously disease-free (CDF), 46 had developed metastasis, of which 20 with local recurrence, and one had developed a radioinduced sarcoma. The site of the tumor (61% of patients with Ewing's sarcoma of the extremities were CDF vs. 35% with tumor of the pelvis) and the kind of local treatment (61% of patients who underwent surgery with or without radiation therapy were CDF vs. 35% of patients treated with radiation therapy alone) were important prognostic factors. These results are similar to those obtained in 59 patients treated from 1979 to 1982 (average follow-up, 10 years) using the same drugs administered according to adjuvant chemotherapy procedure as well as those reported in the only other large study on this subject in the literature (the multi-institution German study CESS-81). The authors conclude that even though neoadjuvant chemotherapy makes surgery possible and easier in Ewing's sarcoma, it does not significantly increase survival when compared to traditional adjuvant treatment.

Adolescent↗
PubMed1991

Neoadjuvant chemotherapy for nonmetastatic osteosarcoma of the extremities.

Between September 1986 and December 1988, 125 patients with osteosarcoma of the extremities entered the second neoadjuvant study at the authors' institution. Patients received preoperatively two cycles of methotrexate (MTX) intravenously, followed by cisplatinum (CDP) intraarterially, plus adriamycin (ADM) intravenously. After surgery, the patients classified as "good responders" (more than 90% tumor necrosis) received ADM, MTX, and CDP, while the "poor responders" (less than 90% tumor necrosis) had a longer chemotherapy that included ifosfamide and etoposide (VP-16) in addition to MTX, ADM, and CDP. Limb salvage was possible in 85% of patients, 8% had an amputation, and 7% had a rotationplasty. The surgical margins were adequate (radical or wide) in 88% of cases and inadequate (marginal or intralesional) in 12%. At an average follow-up period of 28 months (range, 13 to 41), 109 patients (87%) remained continuously disease free, 15 (12%) relapsed with pulmonary metastases, and one patient (0.8%) had a local recurrence. Compared with the first neoadjuvant study at the authors' institution that used only MTX and CDP preoperatively, the percentage of limb salvages, "good responders," and continuously disease-free survival at two years was significantly higher in the second Rizzoli neoadjuvant study (85%, 74%, and 87% versus 77%, 52%, and 59%). Systemic toxicity because of chemotherapy was superimposable. A retrospective analysis of the real dose intensity for each patient demonstrated a correlation between the intensity of chemotherapy and prognosis.

Adolescent↗