Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Child Care Health Dev ; 35(2): 271-80, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19228160

RESUMO

AIM: To explore the frequency with which children and young people participate in social activities with peers, when they are affected by Mucopolysaccharidosis I Hurler Disease (MPS IH) post bone marrow transplant (BMT). This was investigated in relation to patient age, and in comparison with a normative sample. Patient withdrawal, adaptive and social skills are also described in terms of patient age and in comparison with a normative sample. METHOD: Forty-four individuals affected by MPS IH post BMT participated in this investigation. Their ages ranged from 16 months to 25 years. Semi-structured interviews with patients' mothers were utilized, which included the Behaviour Assessment System for Children and a socialization questionnaire. Normative data for the socialization questionnaire were collected from 46 mothers of children not affected by chronic illness or disability. RESULTS: A one-way ANOVA revealed that children not affected by disability or chronic illness (mean = 20.63) participated overall in social activities more frequently than children aged under 12 years (mean = 14.87) and over 12 years (mean = 13.25) who were affected by MPS IH post BMT (F = 21.01, P < 0.001). Young people aged 12 years and over affected by this condition were found to participate in social activities the least. A pattern also emerged, which indicated greater withdrawal and less well-developed adaptive and social skills for MPS IH patients aged 2.5-5 years and 12 years and over, but scores were within the normal range for those aged 6-11 years. CONCLUSION: These data illustrate a lack of social competency and a tendency towards inhibition and withdrawal in this patient group, particularly among the very young children and the adolescents and young adults. Further research is needed to explore these issues longitudinally and to examine the role played by the family, and indeed disability, in the quality and quantity of social interaction experienced by these individuals.


Assuntos
Adaptação Psicológica/fisiologia , Transplante de Medula Óssea , Desenvolvimento Infantil/fisiologia , Relações Interpessoais , Mucopolissacaridose I/psicologia , Estresse Psicológico/psicologia , Adolescente , Adulto , Análise de Variância , Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/psicologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Mucopolissacaridose I/cirurgia , Grupo Associado , Resultado do Tratamento
2.
Zentralbl Chir ; 129(3): 216-9, 2004 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-15237330

RESUMO

After excision of pilonidal sinus treatment consists either in open procedure or primary closure. We present the results of 45 consecutive patients (male 29, female 16, age 32 +/- 13 years), who underwent surgery between September 2001 and December 2002. Fourteen patients had simple fistula without infection, 18 had fistulas with putride secretion and 13 had abscess. Primary closure with direct suture was performed in 34 patients (76 %: 13 x simple fistula, 13 x fistula with putride secretion, 8 x abscess). Eleven patients were treated by layopen procedure and secondary wound healing. Wound infection occurred in 13 patients (7 x superficial, 6 x deep). Mean time of postoperative treatment was 15 +/- 3 days after closure and primary healing and 66 +/- 15 days after open proce dure or secondary healing. Mean time out of work was 19 +/- 10 respectively 52 +/- 19 days. A recurrence of fistula occurred in eight patients after primary closure (18 %) and none after open procedure. Also in cases of pilonidal sinus with infection, primary wound closure can be carried out even though the rate of recurrences is higher than after open procedure. A successful primary closure significantly reduces time of illness and time out of work.


Assuntos
Abscesso/cirurgia , Seio Pilonidal/cirurgia , Complicações Pós-Operatórias/etiologia , Técnicas de Sutura , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/cirurgia , Recidiva , Reoperação/estatística & dados numéricos , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/cirurgia
3.
Zentralbl Chir ; 129(1): 58-62, 2004 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-15011114

RESUMO

Suspected extraluminal recurrence of rectal carcinoma after surgical treatment represents a frequent diagnostic challenge. Clinical history and examination as well as tomographic imaging often do not equivocally settle this tissue. Glucose-PET is an expensive, not universally available test. Early diagnosis is required for both successful operative reintervention aiming at cure and indication to palliative therapy. We performed gun-biopsy of presacral space-occupying lesions in three patients, choosing the ultrasound-guided transrectal approach in three of them. Extraluminal recurrence was proven in one patient. In another patient, anastomotic recurrence was proven by endoscopic biopsy and presacral recurrence ruled out before reoperation. In the third patient, no tumour tissue was found in the samples, as confirmed by his clinical course and by another biopsy after one year. By providing a sufficient amount of tissue for histological examination, ultrasound-guided gun-biopsy allows definite diagnosis in presacral space-occupying lesions and hence represents an important expansion of the diagnostic repertoire in the follow-up of rectal cancer.


Assuntos
Adenocarcinoma/patologia , Adenocarcinoma/secundário , Biópsia por Agulha/instrumentação , Endossonografia/instrumentação , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/patologia , Neoplasias Retais/secundário , Neoplasias Retroperitoneais/patologia , Sacro/patologia , Neoplasias da Coluna Vertebral/patologia , Neoplasias da Coluna Vertebral/secundário , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/cirurgia , Idoso , Terapia Combinada , Diagnóstico Diferencial , Desenho de Equipamento , Seguimentos , Humanos , Masculino , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/cirurgia , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/cirurgia , Reto/diagnóstico por imagem , Reto/patologia , Reto/cirurgia , Reoperação , Neoplasias Retroperitoneais/diagnóstico por imagem , Neoplasias Retroperitoneais/cirurgia , Sacro/diagnóstico por imagem , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/cirurgia , Tomografia Computadorizada por Raios X
4.
Obstet Gynecol ; 98(5 Pt 1): 745-50, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11704163

RESUMO

OBJECTIVE: To estimate the efficacy of preoperative administration of intravaginal metronidazole for the prevention of postcesarean endometritis. METHODS: This double-masked, placebo-controlled randomized trial included patients of at least 24 weeks' gestation undergoing cesarean deliveries for various indications. Patients were randomized to receive either 5 g of metronidazole gel intravaginally or matching placebo before the initiation of the cesarean. All patients underwent surgical cleansing of the abdomen, and most received prophylactic antibiotics after cord clamping. Patients with chorioamnionitis and/or suspected allergy to metronidazole were excluded. For a two-sided alpha of 0.05 and beta of 0.20 (80% power), 120 subjects were required in each group. The main outcome variable was the incidence of postcesarean endometritis. Secondary outcome variables included presence of febrile morbidity, wound infection, days on antibiotics, and length of postpartum hospitalization. Neonatal outcomes included birth weight, Apgar scores less than 7 at 5 minutes, umbilical arterial pH less than 7.16, admission and length of stay in the neonatal intensive care unit, and length of hospital stay. RESULTS: Of 112 patients receiving metronidazole, eight (7%) developed postcesarean endometritis, compared with 19 of 112 (17%) of those receiving placebo gel (relative risk 0.42, 95% confidence interval 0.19, 0.92). No significant differences were noted between treatment groups with respect to the other outcome variables. CONCLUSION: The preoperative administration of 5 g of intravaginal metronidazole gel appears to reduce the incidence of postcesarean endometritis.


Assuntos
Anti-Infecciosos/uso terapêutico , Cesárea , Endometrite/prevenção & controle , Metronidazol/uso terapêutico , Complicações Pós-Operatórias/prevenção & controle , Pré-Medicação , Administração Intravaginal , Adulto , Método Duplo-Cego , Endometrite/epidemiologia , Feminino , Géis , Humanos , Incidência , Complicações Pós-Operatórias/epidemiologia , Gravidez
5.
Obstet Gynecol ; 96(5 Pt 2): 861-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11094242

RESUMO

OBJECTIVE: To evaluate the effectiveness of intrapartum prophylactic amnioinfusion in pregnancies complicated by oligohydramnios. DATA SOURCES: Randomized controlled trials of prophylactic amnioinfusion in women with oligohydramnios were identified using computerized databases, index reviews, and references cited in original studies and review articles. METHODS OF STUDY SELECTION: We evaluated, abstracted data from, and analyzed randomized studies of prophylactic intrapartum amnioinfusion in women with oligohydramnios. In every study the group allocation was based exclusively on presence of oligohydramnios. Only published studies with clearly documented outcome data were included. The quality of each trial was evaluated for methodology, inclusion and exclusion criteria, adequacy of randomization, amnioinfusion protocols, definition of outcomes, and statistical analyses. The trials were evaluated concerning cesarean deliveries for fetal heart rate (FHR) abnormalities, overall cesarean rates, acidemia at birth, intrapartum fetal heart rate abnormalities, Apgar scores under 7 at 5 minutes, and postpartum endometritis. TABULATION, INTEGRATION, AND RESULTS: Thirty-five studies were identified, of which 14 met the inclusion criteria for this systematic review. They included 1533 patients, 793 in the amnioinfusion group, and 740 controls. Odds ratios (OR) with their 95% confidence intervals (CI) for each outcome were calculated. We calculated an estimate of the OR and risk difference for dichotomous outcomes using random and fixed-effects models. A test of homogeneity was done across studies. Women with oligohydramnios who received intrapartum amnioinfusion had lower incidence of cesarean for FHR abnormalities (OR 0.23; 95% CI 0.15, 0.35). Intrapartum amnioinfusion also was associated with lower overall rates of cesarean deliveries (OR 0.52; 95% CI 0.40, 0. 68), acidemia at birth (OR 0.40; 95% CI 0.30, 0.55), FHR abnormalities during labor (OR 0.24; 95% CI 0.17, 0.34), and Apgar scores under 7 at 5 minutes (OR 0.52; 95% CI 0.29, 0.91). Postpartum endometritis rates were similar among the study groups. CONCLUSION: In the presence of oligohydramnios, prophylactic intrapartum amnioinfusion significantly improves neonatal outcome and lessens the rate of cesarean delivery, without increasing the rate of postpartum endometritis.


Assuntos
Líquido Amniótico , Oligo-Hidrâmnio/terapia , Resultado da Gravidez , Índice de Apgar , Cesárea , Feminino , Frequência Cardíaca Fetal , Humanos , Recém-Nascido , Oligo-Hidrâmnio/prevenção & controle , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
Reprod Fertil Dev ; 12(5-6): 251-61, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11451015

RESUMO

Sperm were incubated for up to 9 days in the presence or absence of exogenous hydrogen peroxide, phenylalanine, catalase and aurintricarboxylic acid to assess the influence of reactive oxygen species and inhibition of deoxyribonucleases on sperm chromatin stability. The assessment of sperm DNA susceptibility to in situ acid denaturation by the sperm chromatin structure assay did not detect any difference in chromatin stability between sperm incubated for 9 days under aerobic and anaerobic conditions in a diluent called 14G. Exposure to exogenous hydrogen peroxide under both aerobic and anaerobic conditions and to phenylalanine under aerobic conditions (which produces hydrogen peroxide by a reaction catalysed by the aromatic amino acid oxidase present in sperm) was detrimental to sperm chromatin stability, increasing its DNA susceptibility to in situ acid denaturation over the incubation time. This effect was eliminated if catalase was present in the diluent. Inclusion of the general deoxyribonuclease inhibitor aurintricarboxylic acid in the diluent severely decreased sperm chromatin stability under both aerobic and anaerobic conditions. Aurintricarboxylic acid was mildly cytotoxic, as revealed by viability assessment, under aerobic, but not under anaerobic, incubation conditions. Exogenous hydrogen peroxide, either directly added to the diluent or generated through the enzymatic oxidation of phenylalanine, was detrimental to sperm motility and the integrity of the plasma membrane.


Assuntos
Dano ao DNA , Inibidores Enzimáticos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Espermatozoides/fisiologia , Animais , Ácido Aurintricarboxílico/farmacologia , Catalase/metabolismo , Catalase/farmacologia , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Cromatina/química , Cromatina/efeitos dos fármacos , Meios de Cultura , Desoxirribonucleases/antagonistas & inibidores , Peróxido de Hidrogênio/farmacologia , Masculino , Fenilalanina/química , Fenilalanina/metabolismo , Preservação do Sêmen , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Temperatura
7.
Int J Androl ; 22(2): 77-82, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10194638

RESUMO

Associations of abnormal spermatozoa with bull fertility have yielded varying results. Manual methods of analysis are subjective and highly variable within and between technicians, which may account for these differences. Computer-aided sperm head morphometry appears to be a precise method of assessing sperm head dimensions; however, the effects of replication and technician on sperm head morphometry have not been assessed. The objective of this study was to determine the inter- and intra-analysis and technician variation associated with computer-aided bull sperm head morphometry analysis. Semen from 10 bulls was diluted to 200 x 10(6) sperm/mL, and slide smears were prepared and stained using haematoxylin and rose bengal. Each of two technicians analysed 250 images from each slide, 3 times, using computer-aided sperm head morphometry analysis. The morphometric dimensions of area, perimeter, length, width and width/length for individual sperm heads of each analysis were assessed by GLM-ANOVA for effects of bulls, replications and technicians. The coefficient of variation was recorded for each analysis and across replications. The mean coefficients of variation within and between analyses were compared between technicians by GLM-ANOVA. No differences (p > 0.1) between technicians were found between or among bulls for area (29.63 vs. 29.26 micron 2), perimeter (23.73 vs. 23.86 microns), length (8.73 vs. 8.71 microns), width (4.47 vs. 4.46 microns), or width/length (0.51 vs. 0.51). No differences (p > 0.1) between replicates for sperm head dimension were detected within or among bulls for either technician. No intra- or inter-analysis differences (p > 0.1) between technicians on CVs were observed. The mean intra-analysis CVs for all bulls for both technicians were area = 6.9%, perimeter = 4.9%, length = 4.5%, width = 5.6% and width/length = 6.5%. The mean interanalysis CVs for both technicians were area = 3.0%, perimeter = 2.4%, length = 2.0%, width = 2.0%, and width/length = 1.7%. The results indicate that ASMA is a repeatable and objective method of assessing bull sperm head morphometry within and between technicians. No differences between replications were detected, and hence replicate analyses are not necessary to acquire accurate morphometric data.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Cabeça do Espermatozoide/ultraestrutura , Animais , Bovinos , Masculino , Reprodutibilidade dos Testes
8.
Pulm Pharmacol Ther ; 12(1): 7-12, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10208831

RESUMO

Angiotensin II potentiates the contractions evoked by endothelin-1. Previous studies have suggested that the mechanism underlying this effect may involve leukotrienes. The effects of the leukotriene synthesis inhibitor MK886 and of the leukotriene receptor antagonist ICI 198615 on angiotensin II-mediated potentiation of endothelin-1-induced contractions were examined. The ability of exogenously applied leukotriene D4 (3x10(-9)M) to potentiate the endothelin-1-induced contractions was also investigated. The presence of angiotensin II (3x10(-7)M) potentiated the constrictions evoked by endothelin-1 (e.g. 170% increase at 3x10(-7)M endothelin-1). In the presence of MK886 (10(-7)-10(-5)M), however, this potentiation was abolished. The presence of ICI 198615 (10(-7)-10(-5)M), likewise abolished the angiotensin II effect. The presence of leukotriene D4(3x10(-9)M), mimicked angiotensin II in significantly potentiating the endothelin-1-evoked responses. These data confirm previous work using nordihydroguaiaretic acid and suggest that leukotrienes contribute to the angiotensin II-mediated potentiation of endothelin-1-evoked contractions.


Assuntos
Angiotensina II/farmacologia , Brônquios/efeitos dos fármacos , Endotelina-1/farmacologia , Antagonistas de Leucotrienos/farmacologia , Vasoconstritores/farmacologia , Animais , Bovinos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Indazóis/farmacologia , Indóis/farmacologia , Leucotrieno D4/farmacologia
9.
J Dairy Sci ; 81(11): 2890-6, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9839231

RESUMO

The efficiency and accuracy of estrus detection using HeatWatch (DDx Inc., Denver, CO) or visual observation were compared in an autumn-calving Friesian herd (n = 48 per group) and a spring-calving Jersey herd (n = 50 per group) grazing on pasture. Cows in the group monitored by the HeatWatch system were fitted with a pressure-sensitive transmitter that signaled mounting activities associated with estrus. Visual observation was carried out for about 20 min before the morning and afternoon milkings and was aided by a strip of paint applied over the tailhead. Ovarian cyclicity was monitored with progesterone concentrations in milk samples collected twice a week. The efficiency and accuracy of estrus detection were, respectively, 98.4 and 97.6% for visual observation and 91.7 and 100% for HeatWatch detection. Autumn-calving herds differed from spring-calving herds in duration of estrus (9.7 vs. 7.3 h), number of mounts (13.6 vs. 8.5), total duration of mounts (36.8 vs. 19.9 s), and mean duration of a mount (2.6 vs. 2.3 s). There was no significant variation in the distribution of the time of onset of estrus or mounting activities at different hours of the day. Conception rate was similar for AI after estrus detection with HeatWatch (65.8%) or after visual observation (65.0%). The highest conception rate was obtained when AI was carried out between 12 and 18 h after the first mount. Both the HeatWatch system and visual observation plus tail painting can be used for estrus detection of dairy cows on pasture.


Assuntos
Bovinos/fisiologia , Detecção do Estro/métodos , Telemetria/métodos , Animais , Feminino , Inseminação Artificial/veterinária , Leite/química , Pintura , Gravidez , Progesterona/análise , Rádio , Reprodução/fisiologia , Estações do Ano , Comportamento Sexual Animal , Cauda , Fatores de Tempo
10.
Mol Microbiol ; 27(1): 121-30, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9466261

RESUMO

Green fluorescent protein (GFP) is a useful reporter to follow the in vivo behaviour of proteins, but the wild-type gfp gene does not function in many organisms, including many plants and filamentous fungi. We show that codon-modified forms of gfp, produced for use in plants, function effectively in Aspergillus nidulans both as gene expression reporters and as vital reporters for protein location. To demonstrate the use of these modified gfps as reporter genes we have used fluorescence to follow ethanol-induced GFP expression from the alcA promoter. Translational fusions with the modified gfp were used to follow protein location in living cells; plant ER-retention signals targeted GFP to the endoplasmic reticulum, whereas fusion to the GAL4 DNA-binding domain targeted it to the nucleus. Nuclear-targeted GFP allowed real-time observation of nuclear movement and division. These modified gfp genes should provide useful markers to follow gene expression, organelle behaviour and protein trafficking in real time.


Assuntos
Aspergillus nidulans/metabolismo , Regulação Fúngica da Expressão Gênica , Genes Reporter , Proteínas Luminescentes/análise , Proteínas Recombinantes de Fusão/análise , Aspergillus nidulans/citologia , Aspergillus nidulans/genética , Biomarcadores/análise , Divisão Celular/genética , Núcleo Celular/química , Núcleo Celular/fisiologia , Eletroforese em Gel de Poliacrilamida , Retículo Endoplasmático/química , Retículo Endoplasmático/fisiologia , Fluorometria , Proteínas de Fluorescência Verde , Proteínas Luminescentes/biossíntese , Proteínas Luminescentes/genética , Microscopia Confocal , Mitose/genética , Plasmídeos , Biossíntese de Proteínas
11.
J Androl ; 19(6): 704-9, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9876021

RESUMO

Artificial insemination using cryopreserved semen is a common management tool of the contemporary livestock producer. However, cryopreservation is detrimental to sperm function and fertility, killing some 50% of the spermatozoa during the process. Prediction of cryopreservation damage from prefreeze samples remains elusive. Computer-automated sperm head morphometry was used in this study to determine the effects of cryopreservation on bovine sperm head morphometry. Semen was collected from 18 bulls and was divided. One portion was extended to 200 x 10(6) sperm/ml and a microscope slide was prepared, while the remaining portion was cryopreserved in a Triscitrate-yolk extender. After thawing, the cryopreserved samples were prepared on microscope slides. All slides were air dried and were stained with hematoxylin and rose bengal. The morphometric dimensions for length, width, width/length, area, and perimeter for a minimum of 200 sperm heads were analyzed from each slide by computer-aided sperm head morphometry analysis, and the mean measurements were recorded. Bull sperm heads were significantly (P < 0.01) smaller in cryopreserved spermatozoa than in the companion extended samples for length (8.56+/-0.07 vs. 8.63+/-0.08 microm), width (4.39+/-0.05 vs. 4.48+/-0.05 microm), area (28.42+/-0.07 vs. 29.14+/-0.08 microm), and perimeter (23.33+/-0.21 vs. 23.70+/-0.23 microm) for all bulls. Width/length was also different (0.513 vs. 0.519). In addition, differences (P < 0.05) were found within 14 of 18 bulls for at least four of the morphometric parameters. The percent change in measures after cryopreservation were correlated (P < or = 0.05) to the variability of the extended sample. Variations in sperm head measurements were lower (P < or = 0.05) in extended samples of the four bulls in which no changes occurred than in extended samples of the remaining 14 bulls. These data suggest that the variability in sperm head measurements of individual bulls, or ejaculates, may be an indicator of sperm cryosurvivability.


Assuntos
Criopreservação , Cabeça do Espermatozoide , Animais , Bovinos , Masculino
12.
Eur J Pharm Sci ; 6(1): 1-10, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16256702

RESUMO

Granulocyte-colony stimulating factor (G-CSF) was administered to sheep in three different nasal formulations and as a subcutaneous injection. The nasal formulations were: a solution containing L-alpha-lysophosphatidylglycerol (LPG), a powder formulation comprising small starch microspheres (SSMS) and a powder formulation comprising SSMS and LPG. Absorption of G-CSF was assessed directly by quantitation in plasma and indirectly by measurement of the pharmacodynamic response in terms of leucocyte and neutrophil counts. After the nasal delivery of the G-CSF powder formulation containing SSMS and LPG the absorption of G-CSF was significantly higher (P<0.01) than that from the simple nasal solution or the powder without the enhancer, but the resulting pharmacological response was not significantly different. The bioavailability of G-CSF from the powder formulation containing SSMS and LPG relative to the subcutaneous injection was 8.4% (+/-3.4). We also found that at the respective G-CSF doses investigated, the pharmacodynamic response of this nasal formulation, was similar to that obtained after the subcutaneous administration. The study indicates that the powder formulation containing enhancers could offer an alternative delivery route for G-CSF in the form of intranasal administration.


Assuntos
Fator Estimulador de Colônias de Granulócitos/farmacocinética , Pós/química , Administração Intranasal , Animais , Disponibilidade Biológica , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/química , Humanos , Injeções Subcutâneas , Lisofosfolipídeos/química , Ovinos , Soluções/química , Amido/química
13.
Theriogenology ; 48(3): 369-76, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16728135

RESUMO

This experiment was designed to test whether spermatozoa encapsulated in an alginate poly-L-lysine matrix had an extended fertile life in vivo after insemination. Estrus was synchronized in 417 primiparous Friesian and Jersey heifers with a system based on a CIDR-B intravaginal device before the heifers were inseminated either during proestrus (24 h after device removal) or at estrus (48 h after device removal). Pregnancy rates to first inseminations did not differ between the 24 and 48 h inseminations (61 vs 60.6%) with liquid semen diluted in Caprogen (control) but differed with encapsulated semen (45.1 vs 68.6%). The difference in pregnancy rates between the 2 types of semen was more pronounced (P < 0.08) in the animals that were visually detected in estrus. The mean survival time of spermatozoa in the female reproductive tract following insemination at the 24-h insemination time was estimated to be 50 +/- 7.5 h. The increased pregnancy rate with insemination of encapsulated spermatozoa at 48 h could have been due to this process predisposing spermatozoa to capacitate soon after insemination.

14.
Theriogenology ; 46(7): 1205-15, 1996 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-16727983

RESUMO

Morphological type classification of spermatozoa is an important component of the modern semen evaluation; however, current methods of analysis are subjective and highly variable between technicians. To reduce the subjectivity and thus variability of sperm morphology assessment, computer automated sperm head morphology analysis (ASMA) has been developed. Previous studies have shown the importance of standardizing ASMA procedures to optimize accuracy. The objective of this study was to standardize ASMA procedures for evaluating bull sperm heads. Semen from 10 fertile bulls was used to standardize procedures for optimal analysis of bull spermatozoa. Sample preparation methods, sperm staining methods and microscopic magnifications were compared. Semen samples that were diluted to a standard concentration of 200 x 10(6) sperm/ml were more efficiently analyzed than raw samples. A modified GZIN staining procedure, incorporating rose bengal as an acrosomal stain, was used for accurate ASMA at a magnification of x 60. The mean morphometric measurements for all bulls were the area (27.30 microM), perimeter (25.36 microM), length(8.65 microM), width(4.40 microM) and width/length (0.50). Within the analyses, coefficients of variation ranged from 3.45% for length to 8.52% for area. The ASMA system correctly digitized sperm heads 97% of the time. Results of this study indicate that bull sperm heads can be accurately analyzed using current standard procedures of ASMA technology.

15.
Pharm Res ; 11(11): 1581-7, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7870675

RESUMO

Recombinant human keratinocyte growth factor (rhKGF) is prone to aggregation at elevated temperatures. Its aggregation pathway is proposed to proceed initially with a conformational change which perhaps results from repulsion between positively charged residues in clusters forming heparin binding sites. Unfolding of the protein leads to formation of large soluble aggregates. These soluble aggregates then form disulfide cross-linked precipitates. Finally these precipitates are converted to scrambled disulfides and/or non-disulfide cross-linked precipitates. Stabilizers such as heparin, sulfated polysaccharides, anionic polymers and citrate can greatly decrease the rate of aggregation of rhKGF at elevated temperatures. These molecules may all act by reducing charge repulsion on the protein thus stabilizing the native conformation. EDTA, on the other hand, is found to inhibit disulfide formation in aggregates and has only a moderate stabilizing effect on rhKGF.


Assuntos
Fatores de Crescimento de Fibroblastos , Substâncias de Crescimento/química , Ânions , Soluções Tampão , Precipitação Química , Citratos/química , Ácido Cítrico , Estabilidade de Medicamentos , Fator 10 de Crescimento de Fibroblastos , Fator 7 de Crescimento de Fibroblastos , Humanos , Proteínas Recombinantes/química
16.
J Biomater Sci Polym Ed ; 5(5): 421-31, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8038137

RESUMO

ABA block copolymers of polyethylene glycol and poly-DL-lactic acid were prepared by ring-opening polymerization of DL-dilactide with alpha,omega-dihydroxy polyethylene glycol, Mn 1000 or 2000. The morphology of the resulting copolymers, with PEG:PLA ratios(mol/mol) of 1:2, 1:3 and 1:4, was characterized by DSC and ESR spectroscopy. The rate of water uptake was biphasic, reflecting the contribution of two processes: rapid diffusion of water into the initially miscible PEG and PLA blocks; then a slower rate of hydration possibly due to phase separation and hydrolytic cleavage of the PLA blocks. The rate of hydrolytic degradation of the block copolymers in DI water at 37 degrees C was measured by two methods: weight loss and colorimetric analysis of the carboxy end group concentration resulting from chain scission of PLA blocks. As a result of phase separation, the rate of scission of PLA blocks in the copolymers was similar to that of the PLA homopolymer. The more rapid onset of weight loss of the copolymers, relative to PLA, is attributed to the greater water solubility of PEG-PLA oligomers and their greater diffusivity in the more highly hydrated copolymers.


Assuntos
Materiais Biocompatíveis , Lactatos/química , Ácido Láctico , Polietilenoglicóis/química , Polímeros/química , Hidrólise , Cinética , Lactatos/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Poliésteres , Polietilenoglicóis/síntese química , Relação Estrutura-Atividade , Termodinâmica
18.
Appl Opt ; 32(21): 3981-8, 1993 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-20830039

RESUMO

Waveguide modulators incorporating paralle-plate electrodes are investigated by computer modeling. Metal-electrode structures differ from severe optical losses that are due to surface plasmons. Siliconelectrode structures exhibit lower losses. Bandwidth is limited by the resistivity and the proximity of the electrodes. Doping the silicon improves conductivity but incireases optical absorption. Device optimization involves a trade-off between bandwidth and optical loss. Devices are fabricated by the use of substrates of silicon on sapphire, with rf sputtered lithium niobate films and plasma-enhanced chemical vapor-deposited hydrogenated amorphous silicon for the upper electrodes. The electro-optic coefficient of these lithium niobate films is ~50% of the value for bulk material. The results indicate the possibility of using these devices for combining silicon integrated circuits with waveguide modulators on a common substrate.

20.
Biomaterials ; 12(8): 715-21, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1665991

RESUMO

The molecular motions of spin-labelled ligands covalently bound by spacer groups to an hydrophobic and an hydrophilic polymer matrix were evaluated by ESR spectroscopy. The ligands were prepared by alkylation of 4-N-methylamino-TEMPO with the omega-bromocarboxylic esters, Br(CH2)nCOOEt, n = 1,4 and 10. The hydrolysed esters were coupled to a cross-linked aminoethylated polyacrylamide hydrogel (n = 1,4,10) and to a surface hydroxylated elastomeric polyester (n = 4). The rotational correlation times (tau c) of the nitroxide label in the hydrogels were measured in the dry state and after exposure to water at pH 4, 7.4 and 10.5. The tau c of the nitroxide label was insensitive to the length of the spacer group and to the degree of protonation of the tertiary amino group of the ligand. There was no evidence of self-association of the ligand and spacer, or more than a single phase within the polyacrylamide hydrogel. The tau c of the nitroxide labelled polyester was similarly insensitive to pH, but was sensitive to organic solvents. The low mobility of the spin label and its high concentration were consistent with the spin label being covalently bound within the hydrophobic polyester matrix to a depth of at least 5 microns.


Assuntos
Ligantes , Sondas Moleculares , Polímeros/química , Marcadores de Spin , Resinas Acrílicas/química , Ácidos Carboxílicos/química , Óxidos N-Cíclicos/síntese química , Óxidos N-Cíclicos/química , Microanálise por Sonda Eletrônica , Espectroscopia de Ressonância de Spin Eletrônica , Hidrólise , Cinética , Metilaminas/química , Análise Espectral , Marcadores de Spin/síntese química , Propriedades de Superfície , Termodinâmica , Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...