RESUMO
Semen samples obtained from 18 healthy volunteers and 42 subfertile men were divided into four groups: normospermia (n = 18), oligozoospermia (n = 21), asthenozoospermia (n = 10), and oligoasthenozoospermia (n = 11). After semen analysis, 10% glycerol was used as a cryoprotectant and the samples were stored in a liquid nitrogen tank at -196 degrees C. We studied the cryosurvival rate of thawed spermatozoa after cryopreservation at one week and one month. Further comparisons of the cryosurvival rate of spermatozoa thawed at 30 minutes, 60 minutes and 120 minutes were also made. Our results showed that: (1) there was no significant difference in the cryosurvival rate between spermatozoa preserved for one week and those preserved for one month (73.3% vs 68.7%, p greater than 0.05); (2) there was, however, a significant difference in the cryosurvival rate of spermatozoa thawed at 60 minutes and those thawed at 120 minutes (74.3% vs 60.2%, p less than 0.05); and (3) there was a significant difference in the cryosurvival rate of oligozoospermia/normospermia (39.0%) vs 73.3%, p less than 0.05) and oligoasthenozoospermia/normospermia (35.0% vs 73.3%, p less than 0.05). Thus, we suggest that artificial insemination with frozen semen be performed within one hour after thawing and that fresh semen is preferred to frozen semen in oligozoospermia and oligoasthenozoospermia patients undergoing artificial insemination.
Assuntos
Criopreservação , Preservação do Sêmen , Adulto , Sobrevivência Celular , Humanos , MasculinoRESUMO
AIMS: To determine the identity and composition of mesophilic Bacillus spp. in faeces sampled from feedlot cattle. METHODS AND RESULTS: Faecal samples from 10 feedlot cattle were analysed. The total aerobic spore count increased from 4.6 x 10(4) CFU g(-1) (before feedlotting, day 0) to 1.6 x 10(6) CFU g(-1) (feedlot for day 76). A total of 150 randomly selected spore isolates (60 each from days 0 and 76 cattle, 30 from feed) were speciated using a Bacillus group-specific PCR-amplified ribosomal DNA restriction analysis technique (Wu et al. 2006). At day 0, Bacillus subtilis and Bacillus cereus predominated with a prevalence of 58.3% and 26.7%, respectively, whereas three species, B. subtilis (50.0%), Bacillus licheniformis (27.6%) and Bacillus clausii (20.0%) predominated in day 76 faecal samples. Of these, only the first two species were present in feed samples at a frequency of 70% and 30% respectively. All B. cereus isolates on day 0, possessed at least one of three enterotoxin genes (nheA, nheB and nheC) but these were completely eliminated after a period of feedlotting. All isolates of B. licheniformis were genotypically heterogeneous according to pulsed-field gel electrophoresis analysis. CONCLUSIONS: Cattle faeces contain large numbers of Bacillus spores representing different mesophilic species. Stable faecal populations of particular Bacillus spp. mimicking those found in feed, were subsequently established by feedlotting. SIGNIFICANCE AND IMPACT OF THE STUDY: The results obtained and methods used in this study will help to investigate the indigenous Bacillus composition in the gastrointestinal tract of cattle and will further guide the administration of Bacillus probiotics.
Assuntos
Bacillus/isolamento & purificação , Fezes/microbiologia , Animais , Bacillus/genética , Bacillus cereus/genética , Bacillus cereus/isolamento & purificação , Bacillus subtilis/genética , Bacillus subtilis/isolamento & purificação , Bovinos , Contagem de Colônia Microbiana/métodos , DNA Bacteriano/genética , DNA Ribossômico/genética , Eletroforese em Gel de Campo Pulsado/métodos , Enterotoxinas/genética , Genes Bacterianos/genética , Mapeamento por Restrição/métodos , Esporos Bacterianos/genética , Esporos Bacterianos/isolamento & purificaçãoRESUMO
Production of embryos that are free of tough outer coats facilitates studies that are not possible with embryos surrounded by impenetrable envelopes. This report describes a new procedure for preventing formation of fertilisation membranes in the sea urchin (Lytechinus pictus) model. This procedure involves treating unfertilised eggs with the enzyme alpha-amylase, which cleaves alpha-1,4 glucosidic bonds in the vitelline layer. A major advantage of this method is that it is very well defined and completely controllable with alpha-amylase inhibitor. The results suggest that intact alpha-1,4 glucosidic bonds are essential for vitelline layer integrity required for formation of the fertilisation membrane. Eggs treated with alpha-amylase possessed the same surface lectin receptors as untreated eggs and, as shown by light and transmission electron microscopy, produced healthy, cleaving embryos that were free of fertilisation envelopes.