No abstract

The use of fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) was evaluated for its ability to distinguish acrosome-intact from acrosome-damaged stallion spermatozoa. Incubation of fresh (acrosome-intact) and frozen-thawed (acrosome-damaged) spermatozoa with FITC-PSA resulted in acrosome-intact spermatozoa that exhibited no fluorescence, while acrosome-damaged spermatozoa exhibited fluorescent staining over the rostral portion of the head and equatorial segment. Experiments using mixtures of various ratios of acrosome-intact and acrosome-damaged spermatozoa determined the precision (intrasample coefficient of variation), and linearity (increased percentage of spermatozoa with PSA binding, with increased percentage of frozen-thawed spermatozoa in a sample) of FITC-PSA binding. The binding of FITC-PSA increased in samples as the portion of frozen-thawed (acrosome-damaged) to fresh (acrosome-intact) spermatozoa increased. A positive correlation existed (r = 0.98, P less than 0.05) between the percentage of FITC-PSA bound sperm and the proportion of damaged spermatozoa added to a sample. Location of PSA lectin binding on acrosome-damaged spermatozoa, determined by electron microscopy using gold-conjugated PSA, was to components of the outer acrosomal membrane and acrosomal matrix. These results demonstrate that FITC-PSA binding may be useful in determining acrosomal integrity of fresh and frozen-thawed stallion spermatozoa.

No abstract

The metabolic mechanism for increased circulating free fatty acids in post-menopausal women with metastatic breast cancer was investigated. Hormone and metabolic response to glucose and growth hormone were compared to cancer patients and control subjects; thyroid, adrenal and pituitary function were evaluated. The results of these studies indicated that breast cancer patients had glucose intolerance and delayed and prolonged insulin secretion, increased basal growth hormone levels and insensitivity of adipose tissue to growth hormone. Cortisol and protein-bound iodine levels were normal and there was no lipolytic factor in the sera of breast cancer patients. The changes observed in breast cancer patients were not attributable to age, obesity, inanition or stress. These metabolic abnormalities may characterize host susceptibility to breast cancer or be effects of tumor.