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1.
Cryobiology ; 60(2): 229-34, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20079725

RESUMO

Cryopreservation of gametes is an important tool in assisted reproduction programs to optimise captive breeding programmes of selected felid species. In this study the vitrification was evaluated in order to cryopreserve the immature domestic cat oocytes by assessing the survival of cumulus-oocyte complexes (COC), and the development competence after IVM and IVF by fresh cat epididymal sperms. From a total of 892 COC obtained from queens after ovariectomy were divided into two groups: Experiment 1 for viability evaluation (150 vitrified and 100 control COC) and Experiment 2 for assessing the developmental competence (414 vitrified and 228 control COC). The viability was evaluated by double staining with carboxyfluorescein and Trypan blue, while the developmental competence was evaluated by in vitro maturation (IVM), in vitro fertilisation (IVF) by fresh epididymal spermatozoa and in vitro culture (IVC). The vitrification was performed in OPS into sucrose medium (1M sucrose in HSOF+6% BSA) containing dimethyl sulfoxide (DMSO) (16.5% final concentration) and ethylene glycol (EG) (16.5% final concentration) as cryoprotectants. Percentage of non-viable COC was significantly higher in Experimental 1 vs Control 1 (11% vs 54.5%; P<0.01), while cleavage rate were significantly lower for vitrified oocytes (Experimental 2) than control 2 (18.6% vs 48.2%; P<0.01). Blastocyst rate on day 8 was higher for control oocytes than vitrified counterparts (4.3% vs 20.6% P<0.01). This vitrification protocol ensured a development to blastocyst stage and it is the first report of development of vitrified GV COC.


Assuntos
Gatos , Criopreservação/veterinária , Oócitos , Animais , Animais Selvagens , Diferenciação Celular , Sobrevivência Celular , Criopreservação/instrumentação , Criopreservação/métodos , Crioprotetores , Células do Cúmulo/citologia , Espécies em Perigo de Extinção , Felidae , Feminino , Fertilização in vitro/veterinária , Técnicas In Vitro , Masculino , Oócitos/citologia , Técnicas de Reprodução Assistida/veterinária
2.
Zygote ; 18(1): 1-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19939333

RESUMO

Cryopreservation of gametes is an important tool in assisted reproduction programmes; long-term storage of oocytes or spermatozoa is necessary when in vitro fertilization (IVF) or artificial insemination is to be performed at a future date. Cryopreservation of epididymal spermatozoa offers a potential tool for rescuing genetic material from males of endangered populations. The objectives of this work were to: (1) examine sperm motility, viability, abnormality and acrosome integrity of frozen-thawed domestic cat epididymal spermatozoa; and (2) evaluate the same cryopreservation method on wild feline spermatozoa, needed to preserve their genetic resources. Epididymides were collected from 20 domestic cats during routine neutering procedure and from two wild felines at autopsy. The sperm samples, diluted with 4% glycerol/Tris/egg yolk, were loaded into 0.25 ml mini-straws, exposed to nitrogen vapour and stored in liquid nitrogen. After 4 weeks, samples were thawed and re-evaluated. The quality of each fresh and frozen-thawed sperm sample was tested by determining the motility (54.7 +/- 11.3% and 32 +/- 13.1% respectively for cat spermatozoa; 38.3 +/- 18.7% and 21.5 +/- 16.8% respectively for tiger spermatozoa), viability (74.3 +/- 8.6% and 45.2 +/- 9.4% respectively for cat spermatozoa; 42.4 +/- 14.5% and 33.5 +/- 12.9% respectively for wild felid spermatozoa), morphology and acrosomal status. The present study showed that feline epididymal spermatozoa can be frozen in egg-yolk extender with 4.0% glycerol in 0.25 ml straws. The procedure used in the present study for epididymal cat sperm cryopreservation may be applied to bank the genetic resources of wild felid species.


Assuntos
Criopreservação/métodos , Epididimo/fisiologia , Reprodução , Espermatozoides/fisiologia , Animais , Gatos , Epididimo/citologia , Masculino , Espermatozoides/citologia , Fatores de Tempo
3.
J Anim Physiol Anim Nutr (Berl) ; 94(5): 549-51, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19906130

RESUMO

Evidence is presented that the buffalo mammary gland contains enzymes that catalyse the synthesis and utilization of glutathione. A significant, inverse correlation (r = 0.79) was detected between colostrum gamma-glutamyltransferase (GGT) and glutathione (GSH), suggesting that the enzyme uses GSH as a substrate for its activity. A similar trend was shown in mammary gland homogenates (r = 0.75). Our results show that GSH is secreted into buffalo colostrum and suggest that the enzyme GGT degrades it. To the authors' knowledge, this is the first demonstration of the involvement of GGT-mediated GSH metabolism in the synthesis of colostrums, which elucidates the role of the enzyme that has always been reported very high in colostrum.


Assuntos
Búfalos/metabolismo , Glutationa/análise , Glutationa/metabolismo , Leite/química , Leite/enzimologia , gama-Glutamiltransferase/metabolismo , Animais , Animais Recém-Nascidos , Feminino , Glutationa/sangue , gama-Glutamiltransferase/sangue
4.
Science ; 261(5125): 1130-4, 1993 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-17790344

RESUMO

Simultaneous in situ measurements of hydrochloric acid (HCl) and chlorine monoxide (ClO) in the Arctic winter vortex showed large HCl losses, of up to 1 part per billion by volume (ppbv), which were correlated with high ClO levels of up to 1.4 ppbv. Air parcel trajectory analysis identified that this conversion of inorganic chlorine occurred at air temperatures of less than 196 +/- 4 kelvin. High ClO was always accompanied by loss of HCI mixing ratios equal to (1/2)(ClO + 2Cl(2)O(2)). These data indicate that the heterogeneous reaction HCl + ClONO(2) --> Cl(2) + HNO(3) on particles of polar stratospheric clouds establishes the chlorine partitioning, which, contrary to earlier notions, begins with an excess of ClONO(2), not HCl.

5.
Science ; 261(5125): 1134-6, 1993 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-17790345

RESUMO

In situ measurements of chlorine monoxide (ClO) at mid- and high northern latitudes are reported for the period October 1991 to February 1992. As early as mid-December and throughout the winter, significant enhancements of this ozone-destroying radical were observed within the polar vortex shortly after temperatures dropped below 195 k. Decreases in ClO observed in February were consistent with the rapid formation of chlorine nitrate (ClONO(2)) by recombination of ClO with nitrogen dioxide (NO(2)) released photochemically from nitric acid (HNO(3)). Outside the vortex, ClO abundances were higher than in previous years as a result of NOx suppression by heterogeneous reactions on sulfate aerosols enhanced by the eruption of Mount Pinatubo.

6.
Science ; 261(5125): 1143-6, 1993 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-17790348

RESUMO

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.

7.
Science ; 261(5125): 1140-3, 1993 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-17790347

RESUMO

Highly resolved aerosol size distributions measured from high-altitude aircraft can be used to describe the effect of the 1991 eruption of Mount Pinatubo on the stratospheric aerosol. In some air masses, aerosol mass mixing ratios increased by factors exceeding 100 and aerosol surface area concentrations increased by factors of 30 or more. Increases in aerosol surface area concentration were accompanied by increases in chlorine monoxide at mid-latitudes when confounding factors were controlled. This observation supports the assertion that reactions occurring on the aerosol can increase the fraction of stratospheric chlorine that occurs in ozone-destroying forms.

8.
Science ; 266(5184): 398-404, 1994 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-17816682

RESUMO

Simultaneous in situ measurements of the concentrations of OH, HO(2), ClO, BrO, NO, and NO(2) demonstrate the predominance of odd-hydrogen and halogen free-radical catalysis in determining the rate of removal of ozone in the lower stratosphere during May 1993. A single catalytic cycle, in which the rate-limiting step is the reaction of HO(2) with ozone, accounted for nearly one-half of the total O(3) removal in this region of the atmosphere. Halogen-radical chemistry was responsible for approximately one-third of the photochemical removal of O(3); reactions involving BrO account for one-half of this loss. Catalytic destruction by NO(2), which for two decades was considered to be the predominant loss process, accounted for less than 20 percent of the O(3) removal. The measurements demonstrate quantitatively the coupling that exists between the radical families. The concentrations of HO(2) and ClO are inversely correlated with those of NO and NO(2). The direct determination of the relative importance of the catalytic loss processes, combined with a demonstration of the reactions linking the hydrogen, halogen, and nitrogen radical concentrations, shows that in the air sampled the rate of O(3) removal was inversely correlated with total NOx, loading.

9.
Pol J Vet Sci ; 22(3): 573-579, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31560466

RESUMO

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.


Assuntos
Antioxidantes/farmacologia , Catalase/farmacologia , Gatos/embriologia , Técnicas de Cultura Embrionária/veterinária , Superóxido Dismutase/farmacologia , Animais , Antioxidantes/administração & dosagem , Catalase/química , Catalase/metabolismo , Meios de Cultura/química , Feminino , Fertilização in vitro/veterinária , Glutationa Peroxidase/metabolismo , Masculino , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo
10.
Ann Anat ; 219: 35-43, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29842992

RESUMO

NGF, BDNF, NT-3 and their specific receptors TrkA, TrkB and TrkC are known to be involved in the development and maintenance of vertebrates' nervous system. However, these molecules play a role also in non-neuronal tissue, such as in the reproductive system. In this study we investigated the presence and localization of neurotrophins and Trk receptors to unravel their potential role in the developing and adult ovary of Japanese quail, a model species well suited for reproduction studies. Western blotting analysis on ovaries of three month old quails in the period of egg laying showed the presence of pro and mature forms of neurotrophins and splice variants of Trk receptors. Immunohistochemical investigation reported that in embryonic ovaries from the 9th day of incubation to the hatching NGF and NT-3 were observed in the cortical and medullar areas respectively, whereas Trk receptors were observed in both areas. In adult ovary, all NTs were detected in glandular stromal cells, NGF and NT-3 also in the nervous component. Regarding follicle components, NGF and BDNF were observed in oocytes and follicular cells. All TrK receptors were present in nervous components and only TrkA in glandular stromal cells. In follicles, TrkA was present in oocyte cytoplasm and TrkB in theca cells. The results suggest an involvement of the neurotrophin system in the quail ovary physiology, promoting the oocyte development and follicular organization in the embryo, as well as oocyte and follicular maturation in adults.


Assuntos
Coturnix/metabolismo , Fatores de Crescimento Neural/análise , Ovário/metabolismo , Receptores Proteína Tirosina Quinases/análise , Animais , Western Blotting , Fator Neurotrófico Derivado do Encéfalo/análise , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Coturnix/crescimento & desenvolvimento , Feminino , Imuno-Histoquímica , Modelos Animais , Fator de Crescimento Neural/análise , Fator de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/metabolismo , Ovário/citologia , Ovário/crescimento & desenvolvimento , Receptores Proteína Tirosina Quinases/metabolismo , Receptor trkA/análise , Receptor trkA/metabolismo , Receptor trkB/análise , Receptor trkB/metabolismo , Receptor trkC/análise , Receptor trkC/metabolismo
11.
Vet Comp Oncol ; 15(4): 1503-1512, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28120522

RESUMO

The expression of sigma-2 receptor (S2R) was assayed in blood and bladder samples from healthy cattle and in blood and bladder of cattle with deltapapillomavirus-associated urothelial tumors. Samples of bladder from cattle with neoplasia had significantly higher S2R than samples of bladder from healthy cattle (95% CI 0.31-0.82, P < 0.05). In addition, significantly higher S2R was detected in the blood of cattle with bladder cancer than blood from healthy cattle (95% CI 0.22-0.41, P < 0.05). The results provide evidence that increased expression of SR2 in blood could be useful as circulating biomarker for bladder cancer in cattle. PGRMC1 protein levels were also found to be increased in blood and bladder from cattle with cancer and increased expression of PGRMC1 transcripts was detected by quantitative real time PCR in samples from cattle neoplasia. Furthermore, electron microscopy revealed phagophores and numerous autophagosomes, ultrastructural hallmark of autophagy.


Assuntos
Doenças dos Bovinos/metabolismo , Receptores sigma/metabolismo , Neoplasias da Bexiga Urinária/veterinária , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Western Blotting/veterinária , Estudos de Casos e Controles , Bovinos , Doenças dos Bovinos/sangue , Microscopia Eletrônica de Transmissão/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Receptores sigma/sangue , Bexiga Urinária/metabolismo , Bexiga Urinária/ultraestrutura , Neoplasias da Bexiga Urinária/sangue , Neoplasias da Bexiga Urinária/metabolismo
12.
Eur Rev Med Pharmacol Sci ; 10(5): 229-34, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17121315

RESUMO

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.


Assuntos
Artrite Juvenil/classificação , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Itália , Masculino , Reumatologia , Sociedades Médicas
13.
Eur Rev Med Pharmacol Sci ; 10(4): 173-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16910346

RESUMO

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.


Assuntos
Anti-Inflamatórios/farmacologia , Colchicina/farmacologia , Febre Familiar do Mediterrâneo/tratamento farmacológico , Periodicidade , Amiloidose/prevenção & controle , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Anti-Inflamatórios/farmacocinética , Criança , Pré-Escolar , Colchicina/administração & dosagem , Colchicina/efeitos adversos , Colchicina/farmacocinética , Proteínas do Citoesqueleto/genética , Interações Medicamentosas , Monitoramento de Medicamentos , Etnicidade/genética , Febre Familiar do Mediterrâneo/genética , Febre Familiar do Mediterrâneo/prevenção & controle , Humanos , Nefropatias/prevenção & controle , Mutação , Pirina
14.
Ann Anat ; 207: 47-54, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26970500

RESUMO

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.


Assuntos
Envelhecimento/metabolismo , Encéfalo/metabolismo , Fundulidae/metabolismo , Fatores de Crescimento Neural/metabolismo , Envelhecimento/patologia , Animais , Encéfalo/citologia , Fundulidae/anatomia & histologia , Especificidade de Órgãos/fisiologia , Distribuição Tecidual
15.
Anat Histol Embryol ; 45(6): 418-427, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26429198

RESUMO

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.


Assuntos
Aquaporina 4/metabolismo , Aquaporina 5/metabolismo , Búfalos/metabolismo , Células Endócrinas/metabolismo , Endotélio/metabolismo , Enterócitos/metabolismo , Intestino Grosso/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Aquaporina 4/genética , Aquaporina 5/genética , Transporte Biológico/fisiologia , Western Blotting/veterinária , Colostro , Imuno-Histoquímica/veterinária , Intestino Grosso/crescimento & desenvolvimento , Masculino , RNA Mensageiro/biossíntese , Água/metabolismo
16.
Res Vet Sci ; 103: 149-55, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26679810

RESUMO

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.


Assuntos
Animais Recém-Nascidos/genética , Aquaporina 4/genética , Aquaporina 5/genética , Búfalos/genética , Colostro/metabolismo , Expressão Gênica , Leite/metabolismo , Animais , Animais Recém-Nascidos/metabolismo , Aquaporina 4/metabolismo , Aquaporina 5/metabolismo , Western Blotting/veterinária , Búfalos/metabolismo , Imuno-Histoquímica/veterinária , Intestino Delgado/metabolismo , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária
17.
Anat Histol Embryol ; 44(5): 391-400, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25348329

RESUMO

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.


Assuntos
Aquaporina 1/metabolismo , Búfalos/metabolismo , Intestino Grosso/metabolismo , Intestino Delgado/metabolismo , Animais , Animais Recém-Nascidos/metabolismo , Animais Lactentes , Aquaporina 1/biossíntese , Aquaporina 1/genética , Colostro , Imuno-Histoquímica , Masculino , RNA Mensageiro/biossíntese
18.
J Control Release ; 58(1): 61-8, 1999 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-10021490

RESUMO

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.


Assuntos
Antivirais/síntese química , Idoxuridina/química , Ácido Láctico/química , Polímeros/química , Pró-Fármacos/síntese química , Animais , Antivirais/química , Análise Diferencial Térmica , Esterases/química , Poliésteres , Pró-Fármacos/química , Solubilidade , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Suínos
19.
J Food Prot ; 63(7): 970-3, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10914671

RESUMO

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.


Assuntos
Microbiologia de Alimentos , Temperatura Alta , Leite/enzimologia , Esterilização , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Búfalos , Isoenzimas , L-Lactato Desidrogenase/metabolismo , Leite/microbiologia , gama-Glutamiltransferase/metabolismo
20.
J Food Prot ; 64(8): 1265-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11510674

RESUMO

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.


Assuntos
Búfalos/fisiologia , Colostro/enzimologia , gama-Globulinas/análise , Fosfatase Alcalina/metabolismo , Animais , Biomarcadores/análise , Estudos de Avaliação como Assunto , Feminino , L-Lactato Desidrogenase/metabolismo , Controle de Qualidade , Espectrofotometria , gama-Glutamiltransferase/metabolismo
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