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There were 479 reported whale shark Rhincodon typus encounters between 1999 and 2011 at the island of Utila, which forms part of the Meso-American Barrier Reef System (MBRS) in the western Caribbean Sea. The majority of R. typus were found to feed on small bait fish associated with various tuna species. Ninety-five individual R. typus, ranging from 2 to 11 m total length (LT ), were identified through their unique spot patterns. A significant male bias (65%) was present. There was no significant difference between the mean ± s.d. LT of female (6·66 ± 1·65 m) and male (6·25 ± 1·60 m) R. typus. Most R. typus were transient to Utila, with 78% sighted only within a single calendar year, although some individuals were sighted in up to 5 years. Mean residency time was modelled to be 11·76 days using maximum likelihood methods.

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OBJECTIVES: This study compares the use of three cancer screening practices (Pap smear, mammogram, and clinical breast examination) 3 years prior to interview among five subgroups of Hispanic women, and examines whether sociodemographic; access; health behavior, perception, and knowledge; and acculturation factors predict screening practices for any subgroup. METHODS: Descriptive and multiple logistic regression analyses were conducted with data pooled from the 1990 and 1992 National Health Interview Surveys on women who reported that they were Hispanic. The study sample includes 2,391 respondents: 668 Mexican-American, 537 Mexican, 332 Puerto Rican, 143 Cuban, and 711 other Hispanic women. RESULTS: Subgroup profiles reveal differences in education, health insurance, use of English language, and screening use. Mexican women were the least likely to be screened with any procedure. Logistic regression results for each screening practice show that having a usual source of care was a positive predictor for obtaining each of the three screening practices within the last 3 years. Being married, being more than 50 years of age, and having knowledge of breast self-examination were all predictors of having a Pap smear. Having health insurance and ever having had a clinical breast examination and Pap smear were predictors of having a mammography, while age, knowledge of breast self-examination, ever having had a Pap smear and mammogram, and being a nonsmoker all predicted having a clinical breast examination. CONCLUSIONS: We conclude that access factors and prior screening are more strongly associated with current screening than are language and ethnic factors. Our data confirm that a disproportionate percentage of Hispanic women are low income and at risk of being underscreened. Our findings from a nationally representative sample of Hispanics have implications for provider practices, ethnic-specific community interventions, and future development of measures and data collection approaches.

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Only 16% of women over 40 years of age are being screened regularly with mammography. To learn what radiologists and technologists can do to increase patient adherence to the screening guidelines of the American Cancer Society, especially by poor, urban women, the authors surveyed patients at a county facility immediately after mammography to document the patients' experiences with technologists and the procedure. Analysis of these data led to the conclusion that the radiologist should encourage an expanded role for the technologist as a breast health educator. By incorporating the use of a well-designed patient brochure, technologists can greatly enhance their effectiveness by decreasing the patient's anxiety and increasing her understanding of the procedure and of the importance of screening. Radiologists need to appreciate the potential of an expanded technologist's role for increasing future referrals.

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These studies examined the mechanisms responsible for the paucity of basal LH pulses during estrus. We confirmed our earlier observations that constant infusion of naloxone during estrus results in the immediate appearance of pulsatile LH secretion during estrus, consisting of LH peak heights and LH interpulse intervals that are similar to those observed during other days of the estrous cycle. We then tested whether the proestrous surge of progesterone was responsible for the suppression of pulsatile LH secretion during estrus. Three treatment regimens were used on proestrus to either block progesterone secretion (pentobarbital) or block its action (progesterone antiserum or the progesterone antagonist, RU 486). After treatment at 12.00 h on proestrus, blood samples were collected during estrus every 10 min for 4 h, and the plasma samples were analyzed for the pattern of LH secretion. Treatment with pentobarbital (35 mg/kg at 12:00 h) blocked the proestrous surges of LH and progesterone and resulted in pulsatile LH secretion during estrus. The LH interpulse interval (72 +/- 7 min) was somewhat slower than that observed in the naloxone-infused animals (54 +/- 8 min). Simultaneous treatment with pentobarbital and progesterone at 12:00 h on proestrus completely prevented the appearance of LH pulses during estrus. Treatment with either progesterone antiserum (0.5 ml, i.v.) or RU 486 (1 mg s.c.) resulted in the initiation of pulsatile LH secretion during estrus. In the RU 486-treated animals, LH peak heights and LH interpulse intervals were similar to those observed in naloxone-infused animals and during other days of the estrous cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

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To assess whether gonadotropin-releasing hormone (GnRH) release from the hypothalamus might be altered by hyperprolactinemia in the male rat, we measured in chronically hyperprolactinemic rats the pituitary GnRH receptor content and described the pattern of luteinizing hormone (LH) release during the postcastration rise in gonadotropin secretion 24 and 72 h after gonadectomy. In intact rats, the effect of hyperprolactinemia was determined by describing the pattern of LH secretion, pituitary GnRH receptor content and assessment of pituitary responsiveness to small doses of GnRH (1.0 ng). In addition, to determine the role endogenous opioids might play in inhibiting GnRH release in hyperprolactinemic rats, we examined the effect of both a continuous infusion and a bolus injection of the opioid antagonist naloxone on the pattern of LH release. Chronic hyperprolactinemia was achieved by implanting 4 pituitaries under the kidney capsules 3-4 weeks before study. Acute hyperprolactinemia was achieved by injecting rats with 1 mg ovine prolactin every 12 h for 3 days. Control animals were untreated or were chronically hyperprolactinemic rats in which the hyperprolactinemia was transiently reversed by treatment for 3 days with the dopamine agonist 2-alpha-bromoergocryptine. The mean LH concentration was greatly decreased at 24 postcastration in chronically hyperprolactinemic rats relative to controls. This decrease was associated with a decrease in LH pulse height and pulse amplitude and pituitary GnRH receptor content, but not with an increase in the LH interpulse interval. In contrast, the decrease in mean LH concentrations in hyperprolactinemic animals at 72 h postcastration was primarily associated with a significantly longer LH interpulse interval than that observed in control animals. Chronic hyperprolactinemia in intact rats decreased the pituitary GnRH receptor content, in addition to decreasing the mean LH concentrations during pulsatile GnRH administration. Chronic hyperprolactinemia also inhibited LH release relative to controls during the continuous 4-hour infusion of naloxone and in response to a bolus injection of naloxone. However, in acutely hyperprolactinemic intact male rats a bolus injection of naloxone increase LH secretion 20 min later to levels similar to those obtained in control rats. In summary, these results indicate that chronic hyperprolactinemia decreased LH secretion by primarily decreasing GnRH secretion as suggested by a decrease in pituitary GnRH receptor content and a decrease in LH pulse frequency and pulse amplitude.(ABSTRACT TRUNCATED AT 400 WORDS)

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Lactation in the rat is characterized by an inhibition of ovarian cyclicity which correlates with a suppression of basal gonadotropin secretion, a decrease in the magnitude of estrogen-induced LH surges and a decrease in the postcastration rise en LH and FSH. Furthermore, pulsatile administration of GnRH (0.4 ng GnRH every 50 min) fails to elicit LH pulses in females nursing 8 pups but produces normal basal LH pulses in females nursing 2 pups. There is a good correlation during lactation among pituitary GnRH receptor content, pituitary responsiveness to GnRH and basal LH secretion. All of these parameters are greatly decreased in the presence of an 8-pup suckling stimulus but are generally normal in the presence of a 2-pup suckling stimulus. Taken together with data from other laboratories suggesting that GnRH positively regulates its own receptors, these data suggest that a large suckling stimulus decreases GnRH release from the hypothalamus. This hypothesis is supported by studies in which GnRH release in lactating rats was indirectly assessed by examining the pulsatile pattern of LH secretion. In intact rats suckling 2 or 8 pups on day 10 postpartum, the pattern of LH secretion was uniformly nonpulsatile. The suppression of pulsatile GnRH release in intact females suckling 2 pups does not appear to be due to the small suckling stimulus itself, because ovariectomized females suckling 2 pups exhibited pulsatile LH secretion on day 10 postpartum, but may be due to some ovarian factor acting within the CNS to inhibit GnRH release. In contrast, in ovariectomized females suckling 8 pups, pulsatile LH secretion was completely suppressed.(ABSTRACT TRUNCATED AT 250 WORDS)

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