Antioxidant supplementation to medium for in vitro embryo production in Felis catus

The development of in vitro embryo production (IVEP) techniques in Felis catus is a fitting model with potential application to the conservation of endangered felid species. To improve the quality of IVEP techniques an appropriate balance of pro- and antioxidants should be provided. Under in vitro conditions, high levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) mRNA provide a defence mechanism against oxidative stress for embryos. In order to improve the development of cat oocytes, the effects of SOD and CAT supplemented to in vitro maturation (IVM) medium and of GPx supplemented to in vitro fertilization (IVF) medium on development and embryo production in vitro were evaluated. Data showed an increase of 70 and 77 % of cleaved embryo and blastocyst formation, respectively, in the experiment with SOD and CAT addition to IVM medium; in the experiment with GPx addition to IVF medium the number of cleaved embryos doubled and the number of embryos increased by 96 %. Therefore, our results were positive and encourage us to continue studies on cat oocytes evaluating the effects of various dosages and combination of antioxidants.

Neurotrophin-4 in the brain of adult Nothobranchius furzeri

Neurotrophin-4 (NT-4) is a member of the well-known family of neurotrophins that regulate the development of neuronal networks by participating in neuronal survival and differentiation, the growth of neuronal processes, synaptic development and plasticity, as well as myelination. NT-4 interacts with two distinct receptors: TrkB, high affinity receptor and p75 low-affinity neurotrophin receptor (p75(NTR)). In the present survey, we identified the gene encoding NT-4 in the teleost Nothobranchius furzeri, a model species for aging research. The identified gene shows a similarity of about 72% with medaka, the closest related species. The neuroanatomical localization of NT-4 mRNA is obtained by using an LNA probe. NT-4 mRNA expression is observed in neurons and glial cells of the forebrain and hindbrain, with very low signal found in the midbrain. This survey confirms that NT-4 is expressed in the brain of N. furzeri during adulthood, suggesting that it could also be implicated in the maintenance and regulation of neuronal functions.

Effect of colostrum and milk on small intestine expression of AQP4 and AQP5 in newborn buffalo calves

Functional studies indicate differences in newborn gastrointestinal morphology and physiology after a meal. Both water and solutes transfer across the intestinal epithelial membrane appear to occur via aquaporins (AQPs). Given that the physiological roles of AQP4 and AQP5 in the developing intestine have not been fully established, the objective of this investigation was to determine their distribution, expression and respective mRNA in the small intestine of colostrums-suckling buffalo calves by using immunohistochemistry, Western blot, and reverse transcriptase-PCR analysis. Results showed different tissue distribution between AQP4 and AQP5 with the presence of the former along the enteric neurons and the latter in the endocrine cells. Moreover, their expression levels were high in the ileum of colostrum-suckling buffalo calves. The data present a link between feeding, intestinal development and water homeostasis, suggesting the involvement of these channel proteins in intestinal permeability and fluid secretion/absorption during this stage of development after birth.

Expression and Localization of Aquaporin 4 and Aquaporin 5 along the Large Intestine of Colostrum-Suckling Buffalo Calves

Aquaporins (AQPs) are membrane channel proteins that play a role in regulating water permeability in many tissues. To date, seven isoforms of AQPs have been reported in the gastrointestinal tract in different mammalian species. In contrast, both tissue distribution and expression of AQPs are unknown in the buffalo. The purpose of this study was to investigate the expression of both AQP4 and AQP5 mRNAs and their relative proteins in the large intestinal tracts of buffalo calves after colostrum suckling using reverse transcriptase polymerase chain reaction (RT-PCR), Western blotting and immunohistochemistry. Our results revealed a diversified tissue AQP4 and AQP5 immunolocalization accompanied by their highest expression in the tissues of colostrum-suckling buffalo calves confirmed by Western blotting. In particular, AQP4 was distributed along the endothelium and enterocytes while AQP5 in the endocrine cells. These findings provide direct evidence for AQP4 and AQP5 expression in the large intestine, suggesting that different AQPs collaborate functionally and distinctively in water handling during intestinal development, especially during the first period after delivery.

Expression and Localization of Aquaporin-1 Along the Intestine of Colostrum Suckling Buffalo Calves

Aquaporin-1 (AQP1), a six-transmembrane domain protein, belongs to a highly conserved group of proteins called aquaporins known to regulate permeability across cell membranes. Although the role of AQP1 has been extensively studied, its specific activity along the gastrointestinal tract in animals during early postnatal development is poorly known. This study investigates the expression of AQP1 mRNA and protein in the small and large intestine of water buffalo calves after colostrum ingestion using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and cellular localization of AQP1 by immunohistochemistry. Our results revealed AQP1 immunoreactivity and the presence of the corresponding mRNA in all the examined tracts of the intestine but with a different cellular localization. Western blotting confirmed the presence of AQP1, with a more intense band in colostrum-suckling animals. These findings offer insights into AQP1 expression in the small and large intestine, suggesting its involvement in osmoregulation in gastrointestinal physiology particularly during the first week after birth in relation to specific maturation of intestinal structures.

Gammaglutamyltransferase activity in buffalo mammary tissue during lactation

In the present study, the rôle of gammaglutamyltransferase (GGT) during lactation has been investigated in the water buffalo. GGT activity has been evaluated in the mammary tissue at 4 and 6 months after calving and during the non-lactating period. The highest GGT activity levels were found at day 120 (32·57±7·41 U per g) of lactation and were statistically higher than those at 180 (10·76±3·6 U per g) or during the non-lactating period (9·86±7·94 U per g). Histochemistry confirmed these findings and revealed that GGT reactivity was distributed throughout the cytoplasm of alveolar epithelial cells. Such results showed that the GGT production is high during lactation thus supporting the hypothesis that this enzyme plays a rôle in determining milk production in water buffalo by supporting milk protein synthesis.

Genetically modified soya bean in rabbit feeding: detection of DNA fragments and evaluation of metabolic effects by enzymatic analysis

The presence of DNA fragments in tissues from rabbits given genetically modified (GM) soya-bean meal (solvent extracted) was investigated by using the polymerase chain reaction (PCR) approach. Moreover, the possible effects on cell metabolism were evaluated by determination of several specific enzymes in serum, heart, skeletal muscle, liver and kidney. The chloroplast sequence for tRNA Leu by using the Clor1/Clor2 primers designed on chloroplast trnL sequence was clearly detected. On the contrary, two couples of species specific primers for conventional (Le1-5/Le 1-3 which amplifies the soya bean lectin gene) and genetically modified (35S1/35S2 which amplifies the 35S CMV promoter that is present in the genomic structure of GM soya bean) soya bean were not found in all samples. No differences in enzyme levels were detected in serum, but a significant increase of lactic dehydrogenase, mainly concerning the LDH1 isoenzyme was found in particular in kidney and heart but not in the muscle, thus suggesting a potential alteration in the local production of the enzyme. Finally, no significant differences were detected concerning body weight, fresh organ weights and no sexual differences were detected.

327 IDENTIFICATION OF OSTEOPONTIN IN WATER BUFFALO SEMEN

The competitiveness of buffalo breeding will depend on the utilization of reproductive biotechnologies that allows acceleration of genetic progress. A major factor hampering the efficiency of both artificial insemination and in vitro embryo production programs in this species is male hypofertility. Reports for several species suggest that seminal plasma contains factors that influence male fertility. Osteopontin is a glycoprotein found in several biological fluids including seminal plasma, and its presence is associated with spermatozoa concentration. In cattle, expression of osteopontin was highly correlated with bull fertility, and it was proposed to be a marker to predict male fertility (Cancel et al. 1999 Biol. Reprod. 60, 454–460). No data are available about the presence or activity of osteopontin in water buffalo. The aim of this preliminary study was to determine if osteopontin is present in buffalo semen and to evaluate whether freezing procedures cause the loss of osteopontin from spermatozoa. Semen was collected in authorized semen collection centers from 6 buffalo bulls by using an artificial vagina. A collection of bovine semen was used as a positive control. An aliquot from each sample was frozen using standard procedures for semen storage. Each ejaculate was centrifuged at 600g for 10 min at room temperature, and the supernatant was recovered and centrifuged at 10 000g for 1 h at 4�C. The total protein concentration in seminal plasma and spermatozoa was determined by the Bradford method, using ovoalbumin as the standard. Proteins (50 �g) were separated by electrophoresis and analyzed by western blotting (Cancel et al. 1999). Polyclonal antibodies against bovine milk osteopontin were prepared as previously described (Cancel et al. 1997 Biol. Reprod. 57, 1293–1301). The intensities of bands indicated by western blot were quantified by densitometer. Osteopontin was detected in all samples of buffalo semen. Most of the osteopontin detected was in the seminal plasma. Relative amounts of osteopontin detected in spermatozoa were 50% or less of that detected in seminal plasma; furthermore, the protein was not found in sperm from all bulls. These results suggest that most osteopontin is produced by the ampullae and seminal vesicles, similar to what was reported for cattle (Cancel et al. 1999). Semen frozen by standard procedures showed a reduction in amount of osteopontin by up to 50%. These studies suggest that the fertility-associated protein osteopontin may be useful as a sensitive tool to evaluate whether sperm storage procedures are detrimental and result in excess loss of osteopontin from sperm. In conclusion, the results have demonstrated that osteopontin is present in buffalo seminal plasma and sperm. Further studies will examine whether the expression of osteopontin is correlated with the fertility of buffalo bulls, as has been demonstrated in bovine bulls.

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.

Focus on juvenile idiopathic arthritis according to the 2001 Edmonton revised classification from the International League of Associations for Rheumatology: an Italian experience

OBJECTIVE

To classify a cohort of Italian patients categorized as affected with juvenile idiopathic arthritis (JIA) according to the revised 2001 Edmonton International League of Associations for Rheumatology (ILAR) criteria.

METHODS

Eighty-five patients with JIA firstly framed depending on traditional criteria during the last ten years were reallocated according to the JIA revised criteria proposed in 2001 by ILAR in Edmonton.

RESULTS

The revision consented to define the following distribution of patients: 28.2% systemic, 55.3% oligoarticular and 11.8% polyarticular forms; only one child was defined as having psoriatic arthritis, one child with enthesitis-associated arthritis and two with the undifferentiated form of JIA.

DISCUSSION

The 97.6% of the recruited patients were strictly classified according to the Edmonton ILAR criteria, demonstrating a very low number of patients whose arthritis could not be assigned to any JIA category due to unfulfillment of the required criteria.

The pharmacologic basis of treatment with colchicine in children with familial Mediterranean fever

Familial Mediterranean fever (FMF) is the prototype of auto-inflammatory disorders and is ethnically restricted to people living in the Mediterranean basin and Middle-East. Pyrin, the protein product of the FMF gene, expressed in myeloid cells and fibroblasts, interacts with the cytoskeletal machinery and may modulate leukocyte effector functions. At present colchicine, an alkaloid with antimitotic activity interfering with microtubule formation, which has been used to alleviate acute gout, is the only available drug for patients with FMF to prevent both acute attacks and long-term complications such as amyloidosis. The anti-inflammatory effect of colchicine may be mediated not only through direct interaction with microtubules, but also through changes at the transcriptional level influencing cell cycle regulation and leukocyte migration. Gastrointestinal side effects may occur early and are the most frequent manifestations of colchicine toxicity in children, whilst multiple organ failure is very rarely reported as overdosage expression.

Evaluation of adenosine 5'-diphosphate (ADP)- and collagen-induced platelet aggregation in canine leishmaniasis

Leishmania-infected dogs, which represent an important reservoir of infection in many parts of the world, frequently suffer from haematological disorders, including thrombocytopenia. In this study, the ability of platelets from healthy (control) dogs (n = 11) and from dogs with naturally acquired clinical leishmaniasis (n = 24) to aggregate in the presence of two different agonists (adenosine 5'-diphosphate [ADP] and collagen) was assayed. Haematological parameters examined consisted of the platelet count, prothrombin time, activated partial thromboplastin time (aPTT), fibrinogen concentration and D-dimer concentration. In dogs with leishmaniasis, a significant decrease in ADP- and collagen-induced platelet aggregation was observed. Compared with platelets from the control dogs, those from leishmania-infected dogs showed a higher sensitivity to collagen, as demonstrated by a reduction in platelet aggregation of up to 20.4%, and a significant (P < 0.0001) difference for all the doses tested. With ADP the reduction was up to 10.4%, the difference reaching a significant level of P < 0.0001 only at the maximum dose used. The nature of this response, which was not accompanied by any clinical signs of bleeding other than an increase in aPTT, emphasizes the role of platelets in the parasite-host cell interaction.

Adhesive properties of platelets from different animal species

The use of large animals (e.g., pig and sheep) in human medicine, and the need to develop new therapeutic strategies for domestic animal diseases related to platelet disorders, require better characterization of the physiology of animal platelets. In this study, the ability of platelets from buffaloes, horses, pigs and sheep to adhere to immobilized autologous fibrinogen was compared with that of human platelets. Blood samples were collected from the jugular vein of six healthy subjects of each species and platelet-rich plasma (PRP) was obtained by centrifugation. Platelets, isolated by further centrifugation of PRP, were washed by gel-filtration on Sepharose-2B, counted and added to the wells of 96-well plates pre-coated with autologous fibrinogen. After different times of incubation, non-adherent platelets were removed, and the number of adherent platelets was assessed by measuring endogenous acid phosphatase activity. Horse platelets showed the strongest ability to adhere to autologous immobilized fibrinogen, being 1.7-, 3.1- and 2.3-fold more active than human, buffalo and porcine platelets, respectively. Sheep platelets were unable to adhere to autologous immobilized fibrinogen. Platelet activation by adenosine 5-diphosphate (ADP) increased both human and animal platelet adhesive response. ADP-stimulated sheep platelets were able to adhere to autologous immobilized fibrinogen, albeit to a lesser extent than platelets from the other animal species. The observed interspecies variability in adhesive properties of platelets may reflect structural differences, or differences in the availability of the fibrinogen receptor (glycoprotein IIb/IIIa) on the platelet surface.

Species variability in platelet aggregation response to different agonists

Conflicting data on platelet function in animal species are reported in the literature. In this study, the response of buffalo, horse, pig and sheep platelets to different agonists was assessed. Blood samples were collected from the jugular vein of six healthy subjects of each species and platelet-rich plasma was obtained by centrifugation. Platelet aggregation responses to increasing doses of adenosine 5'-diphosphate (ADP), arachidonic acid, collagen, platelet activating factor (PAF) and ristocetin were measured by a turbidimetric method. Horse platelets were the most responsive to ADP, collagen and PAF, whereas sheep platelets were the most responsive to ristocetin. The response to arachidonic acid varied least between species. PAF was the most effective agonist, inducing a maximum aggregation response at a concentration of 1 micro M for platelets of each species. Conversely, concentrations of ristocetin higher than 1mg/ml induced a maximum aggregation response only with sheep and horse platelets. The different responses of platelets from the four animal species to various agonists may reflect either (1). structural differences (including composition of the platelet membrane and presence of specific agonist receptors), or (2). activation of distinct signalling pathways by the agonist.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

Stratospheric Meteorological Conditions in the Arctic Polar Vortex, 1991 to 1992

Stratospheric meteorological conditions during the Airborne Arctic Stratospheric Expedition II (AASE II) presented excellent observational opportunities from Bangor, Maine, because the polar vortex was located over southeastern Canada for significant periods during the 1991-1992 winter. Temperature analyses showed that nitric acid trihydrates (NAT temperatures below 195 k) should have formed over small regions in early December. The temperatures in the polar vortex warmed beyond NAT temperatures by late January (earlier than normal). Perturbed chemistry was found to be associated with these cold temperatures.

[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.

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.

[Rate of erythrocyte sedimentation in buffaloes in related to age]

The behavior of the ERS was studied in water buffalo of both sexes from one week to nine years of age. A progressive and considerable increase in the values of the ERS, with a respective increase in the animal's age, was noted. Concerning the factors conditioning such peculiarities, the authors attribute importance to the following items: the number of erythrocytes, the plasmatic viscosity, and the total proteinemia (especially in the region of the gamma-globulins that, among those taken in the study, exhibited the greatest variations).

[Initial observations on the biocompatibility of a polymer used as a skin dressing]

In the development of a dressing for burn wound covers, a material is required which combines good oxygen permeability, high water content and good biocompatibility with reasonable mechanical properties. One of the most important functions of the cover is to protect the burned surfaces from drying out and to constitute the first defence against microbial invasion. In this study composite sheets crosslinked either in presence of glicerol or diacetin, obtained by reinforcing PHEMA with a tricot PET net have been implanted subacute in rabbits, to test their biocompatibility. The same composites crosslinked in presence of diacetin and grafted on a polybutadene film, have been used as a skin graft on rabbits.