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Biomedical subjects

L Avallone

Publications and source records attributed to L Avallone.

At least 19 recordsLinked to original sources
PubMed2006

Platelet aggregation and haemostatic response in dogs naturally co-infected by Leishmania infantum and Ehrlichia canis.

Haemostatic alterations in dogs naturally infected by ehrlichiosis and/or leishmaniasis were studied. Platelet count, ADP and collagen-induced platelet aggregation, prothrombin time, activated partial thromboplastin time (APTT) and plasma fibrinogen concentration were measured. An evident reduction of platelet aggregation response was shown for Leishmania-Ehrlichia co-infected dogs where platelet aggregation was lower in comparison with control and leishmaniotic dogs (ADP and collagen, P < or = 0.01) and ehrlichiotic dogs (ADP 10 and 7.5 microm, P < or = 0.05). Moreover, a significant increase in APTT as well as a reduction of the albumin/globulin rate (A/G) for leishmaniotic and co-infected dogs versus control and ehrlichiotic dogs was detected. The hypothesis of a synergism between leishmaniosis and ehrlichiosis in altering platelet function by different pathways is discussed.

Animals↗
PubMed2001

Evaluation of buffalo colostrum quality by estimation of enzyme activity levels.

A study to evaluate the value and potential use of colostral enzymes as markers for the evaluation of buffalo colostrum quality was conducted. The enzymes gamma-glutamyltransferase (GGT), lactic dehydrogenase (LDH), and alkaline phosphatase (ALP) in buffalo's colostrum were measured spectrophotometrically, and their activities were correlated with the gamma-globulin content. Gamma-globulin concentration was determined following the electrophoretic separation of the colostral proteins and quantified with a densitometer. Colostrum was obtained from 15 dams, soon after calving. Means, standard deviations, correlation coefficients, and degree of significance were calculated using the general linear model procedure of the Statistical Analysis Systems program. The activity of GGT in the colostrum was the highest, followed by LDH and ALP. A significant correlation (r = 0.86; P < 0.001) was seen between GGT and gamma-globulin concentration in the colostrum, supporting the suggestion of using this enzyme as a marker for the evaluation of colostrum quality.

Alkaline Phosphatase↗
PubMed2000

Modulation of anthracycline activity in canine mammary tumour cells in vitro by medroxyprogesterone acetate.

Failure of chemotherapy with anthracyclines as a result of drug resistance and toxicity is a major problem in the clinical management of neoplasia. The aim of the present study was to evaluate the activity of medroxyprogesterone acetate (MPA) as a chemosensitiser on anthracycline cytotoxicity. The study investigated whether such an effect could be related to an increase in lipid peroxidation, nitric oxide production, membrane fluidity and intracellular anthracycline concentration. The results showed that anthracyclines decreased nitric oxide production but increased membrane viscosity (polarisation constant) and lipid hydroperoxide formation in canine mammary tumour cells. Moreover, it was found that both drug-induced cytotoxicity and membrane viscosity increased in the presence of MPA. Conversely, lipid hydroperoxides decreased in MPA-supplemented cells. Medroxyprogesterone acetate did not show any effect on nitric oxide production. The two anthracyclines used (doxorubicin and idarubicin) showed differential intranuclear accumulation in canine mammary tumour cells, and MPA significantly modified intracellular concentration of anthracyclines.

Animals↗
PubMed2000

Buffalo-milk enzyme levels, their sensitivity to heat inactivation, and their possible use as markers for pasteurization.

The activities and rates of inactivation of four enzymes in raw buffalo milk were measured in relation to the process of heating to determine the value of these enzymes as markers for the evaluation of milk pasteurization. The activities of the enzymes alkaline phosphatase (ALP), lactic dehydrogenase (LDH), gamma-glutamyltransferase (GGT), and aspartate aminotransferase (AST) were measured before and after heating at 50, 60, 70, and 80 degrees C for 1, 3, 5, 10, 20, and 30 min. The enzyme GGT showed the highest activity (712 +/- 601 IU/liter), followed by LDH (386 +/- 183 IU/liter), ALP (295 +/- 164 IU/liter), and AST (18 +/- 4 IU/liter). Heating the milk at 50 degrees C for 1 to 30 min resulted in no effect on the activity of any of the enzymes. At 60 degrees C, ALP showed the highest sensitivity to heat inactivation, whereas all other enzymes showed resistance. At 70 degrees C, ALP activity was abolished completely after 1 min, whereas GGT and LDH lost most activity after 10 min, and AST still maintained 50% activity even after 30 min. At 80 degrees C, the activities of LDH and GGT were lost, whereas AST still retained some of its activity. The results suggest that in addition to ALP, LDH and GGT, but not AST, are potential markers for heat denaturation in buffalo milk, with GGT having the advantage that its concentration is the highest.

Alkaline Phosphatase↗
PubMed1999

Synthesis and characterisation of poly(D,L-lactic acid)-idoxuridine conjugate.

A new polymeric prodrug was prepared coupling 5-iodo-2'-deoxyuridine (IDU) to poly(d,l-lactic acid) (PLA) via a succinic acid spacer. The PLA-IDU conjugate was characterised by thermal analysis, IR and 1H and 13C NMR spectroscopy. The IDU content (0.024 mequiv.g-1 of PLA) was consistent with the carboxylic acid endgroup present in the polymer sample (0.025 mequiv.g-1 of polymer). The PLA-IDU conjugate was susceptible to degradation in biological environments containing esterase, whereas IDU was not detected by chemical hydrolysis in pH 7.4 phosphate buffer. The conjugate should be used to prepare injectable microspheres and nanospheres containing IDU chemically coupled to the polymer carrier.

Animals↗
PubMed1999

Ovarian function suppression with a GnRH analogue: D-ser(But[t])[6]-Arzgly[10]-LHRH (Goserelin) in hormone dependent canine mammary cancer.

Hormones and hormone level modifying substances have long been used to treat hormone-dependent tumours in humans. Recently, attempts have been made to use hormone manipulation regimens for the treatment of these tumours in veterinary medicine. The aim of the present study was to evaluate the activity of the luteinizing hormone-releasing hormone (LHRH)-agonist, D-ser(But[t])[6]-Azgly[10]-LHRH (Goserelin) in hormone-dependent mammary cancer in dogs. Eighteen female dogs with hormone-dependent mammary cancer (T2-T4, N0, M0 according to TNM clinical staging classification) were selected and allocated into two groups: nine dogs not treated with Goserelin (Group 1) referred to as control; and nine dogs treated with 60 microg/kg depot Goserelin every 21 days for 12 months (Group 2). Goserelin treatment decreased circulating levels of oestradiol and progesterone and reduced the size of mammary tumours; all the animals showed objective response (OR) to treatment after 3 months, and the relapse-free survival after 2 years was 88%. Haematology and blood chemistry parameters, measured every month from the beginning of treatment, as well as physical examination, showed that the drug was without toxic effects. This suggests that, at the dose administered, Goserelin blocks the hypothalamus-pituitary-ovary axis, and consequently can be useful to treat hormone-dependent mammary tumours in female dogs.

Animals↗
PubMed1998

Research on heterocyclic compounds, Part 40. 2-Phenylimidazo[1,2-a]pyridine-3-carboxylic acid derivatives: synthesis and antiinflammatory activity.

A series of 2-phenylimidazo[1,2-a]pyridine-3-carboxylic esters, acids, and amides were synthesized and pharmacologically tested in order to evaluate their antiinflammatory and analgesic activity and their ulcerogenic action on the gastro-intestinal tract. The most active member of this series of compounds was found to be 6-methyl-2-phenylimidazo[1,2-a]pyridine-3-carboxylic acid (5c).

Animals↗
PubMed1997

Research on heterocyclic compounds. XXXVIII. Synthesis and pharmacological activity of imidazo[1,2-b]pyridazine-2-carboxylic derivatives.

A series of imidazo[1,2-b]pyridazine-2-carboxylic acids, esters and amides was synthesized and tested for antiinflammatory, analgesic and ulcerogenic activities. The ethyl esters were prepared by cyclocondensation of some 3-aminopyridazines with ethyl bromopyruvate, followed by hydrolysis or ammonolysis in order to obtain the corresponding acids and amides. The inhibitory activity on the carrageenan-induced edema in the rat paw and on writhes induced by acetic acid in mice was evaluated, as well as the ulcerogenic action on the rat gastric mucosa. The pharmacological activity was discussed in terms of structure-activity relationships. In particular, the analgestic activity shown by these carboxylic derivatives was compared with that found in other series of imidazo[1,2-b]pyridazine analogues previously examined.

Amides↗
PubMed1996

Preliminary observations on the interference of antiblastic agents in membrane fluidity and leukocyte potential.

A major problem in cancer treatment is the progressive desensitization of the cancer cells to chemotherapeutic drugs. Several hypotheses have been advanced to explain this property of neoplastic cells. In recent years, some calcium-channel blockers have successfully been used to restore drug-sensitivity in previously resistant tumors. The presence of a correlation between ion channels and membrane fluidity is well known. In the ambit of our studies on the activity of several chemotherapeutic drugs on tumors, we have studied the variations in membrane depolarization and fluidity in some leukemic cells as a result of polychemotherapeutic treatments. Our results demonstrate that the membrane fluidity and K(+)-induced depolarization of some types of leukemic cells in patients untreated and treated with some chemotherapeutic agents, are altered significantly as compared to those of normal leukocytes.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Age-dependent variations of lactate dehydrogenase and creatine kinase activities in water buffalo calf serum.

The electrophoretic patterns of the serum enzymes lactate dehydrogenase and creatine kinase from water buffalo calves are described. Differences in total activities as well as their relative distribution were seen at ages ranging from 1 to 10 weeks. While total lactate dehydrogenase activity increased by over 100%, total creatine kinase increased by almost 400%. The relative activities of lactate dehydrogenase 1 and 5 decreased with age. Lactate dehydrogenase 2 and 3 increased and lactate dehydrogenase 4 did not change. In relation to creatine kinase, the prevalent isoenzyme was creatine kinase-MM, but it's relative activity gradually decreased in comparison to the other two isoenzymes (creatine kinase-MB and creatine kinase-BB). Creatine kinase-BB was completely absent until the 3rd week of age. The percentage modifications of creatine kinase isoenzymes were correlated to age. The results suggest that isoenzymatic separation and characterization of lactate dehydrogenase and creatine kinase in relation to the various tissues can significantly contribute to the diagnosis of diseases which are linked to tissue damage.

Aging↗
PubMed1996

gamma-Glutamyltransferase and serum proteins in buffalo calves following colostral ingestion.

Catalytic activity concentrations of gamma-glutamyltransferase in blood were determined for the evaluation of colostral ingestion. gamma-Glutamyltransferase levels were compared with those of total proteins, albumins and total globulins in the serum, showing good correlation at 2-3 days after birth. gamma-Glutamyltransferase was determined using the Boehringer Mannheim "Reflotron" dry chemistry enzyme strips. After colostral ingestion, blood gamma-glutamyltransferase increased from 35 +/- 19 U/l at birth to 1563 +/- 1283 U/l. Electrophoretic separation of total proteins showed an increase of serum gamma-globulins from 4.2 g/l before ingestion to 32.9 g/l after ingestion. The same analytes were determined in colostrum showing the major protein fraction to be gamma-globulins. gamma-Globulins and gamma-glutamyltransferase permeate to the blood stream, and there is a good correlation between them. The enzyme gamma-glutamyltransferase can be used as an equivalent for the determination of gamma-globulins in the calf serum and the degree of colostral ingestion.

Animals↗
PubMed1989

[Morphostructural features of the pleural lymphatic circulation in the pig].

The morphostructural features of the lymphatic circle of swine visceral pleura were investigated by means of vital dye injection in the pleural cavity. In the animals treated as mentioned previously it was possible to observe that in the visceral pleura the superficial lymphatic network had formed the very thick mesh, while the underlying pulmonary parenchyma was not interested. This behaviour lets us suppose that the drainage of the visceral pleura is mainly a direct one.

Animals↗
PubMed1987

The serum lipoprotein pattern of water buffalo (Bubalus bubalis).

1. The serum lipoprotein pattern of water buffalo was studied by means of electrophoresis and the lipoproteins were isolated by ultracentrifugation on the basis of their hydrated density. 2. High density lipoproteins (HDL) showed a higher level of cholesterol than did the other lipoproteins. Moreover, the level of phospholipids was higher in HDL than in very low density lipoproteins (VLDL). 3. The buffalo B100 apoprotein was similar to that of man and rat. Three apoproteins similar to human apo E, apo AI and AII were found in buffalo HDL, buffalo VLDL contained essentially apo B protein.

Animals↗