PRL and GH synthesis and release from the sea bream (Sparus auratus L.) pituitary gland in vitro in response to osmotic challenge.

The endocrine factors prolactin (PRL) and growth hormone (GH) are believed to have counteracting effects in the adaption of fish to changes in environmental salinity. In order to further investigate this interaction sea bream were challenged with full seawater (SW) or freshwater (FW) for 7 days and the response of pituitary glands cultured in vitro to an osmotic challenge (230, 275 and 320 mOsm/kg) was assessed. In vitro PRL secretion from pituitaries of SW-adapted fish was unaltered in response to an osmotic challenge, while GH secretion increased in the lowest osmolality (230 mOsm/kg). In contrast, both GH and PRL secretion by pituitaries from FW challenged fish was significantly increased (p<0.01) over that of pituitaries from SW fish at the highest osmolality (320 mOsm/kg). After FW challenge pituitary PRL content and de novo synthesised and released PRL were significantly increased (p<0.01), while total PRL secretion was not different from SW animals. GH pituitary content decreased in FW animals while total secretion and secretion of de novo synthesised protein were significantly increased (p<0.01). In addition, after transfer of fish to FW expression of PRL and GH increased 3- and 2-fold, respectively. Despite the increase in PRL expression, no increase in total PRL secretion occurred and although in gills a 2-fold increase in the osmoregulatory marker, Na(+)/K(+)-ATPase activity was detected, profound haemodilution and a cumulative mortality of 40% occurred in sea bream placed in FW. Taken together the results suggest that the sea bream pituitary gland fails to respond appropriately to the osmotic challenge caused by low salinity and the physiological response evoked in vivo is not enough to allow this species to withstand and adapt to FW.

The Effect of Anchors and Training on the Reliability of Voice Quality Ratings for Different Types of Speech Stimuli.

OBJECTIVE: The main objective of the present study was to investigate if the type of voice stimuli-sustained vowel, oral reading, and connected speech-results in good intrarater and interrater agreement/reliability. STUDY DESIGN: A short-term panel study was performed. METHODS: Voice samples from 30 native European Portuguese speakers were used in the present study. The speech materials used were (1) the sustained vowel /a/, (2) oral reading of the European Portuguese version of "The Story of Arthur the Rat," and (3) connected speech. After an extensive training with textual and auditory anchors, the judges were asked to rate the severity of dysphonic voice stimuli using the phonation dimensions G, R, and B from the GRBAS scale. The voice samples were judged 6 months and 1 year after the training. RESULTS: Intrarater agreement and reliability were generally very good for all the phonation dimensions and voice stimuli. The highest interrater reliability was obtained using the oral reading stimulus, particularly for phonation dimensions grade (G) and breathiness (B). Roughness (R) was the voice quality that was the most difficult to evaluate, leading to interrater unreliability in all voice quality ratings. CONCLUSIONS: Extensive training using textual and auditory anchors and the use of anchors during the voice evaluations appear to be good methods for auditory-perceptual evaluation of dysphonic voices. The best results of interrater reliability were obtained when the oral reading stimulus was used. Breathiness appears to be a voice quality that is easier to evaluate than roughness.

The prevalence of laryngeal pathologies in an academic population.

OBJECTIVE: The main purposes of the present study were to determine the prevalence of laryngeal pathology and voice disorders and to identify their associated risk factors among the workers, teachers, and nonteachers, from a Portuguese university. STUDY DESIGN: Cross-sectional study. METHODOLOGY: A total of 101 participants have volunteered to participate in a voice survey. Data were collected using a questionnaire followed by the diagnosis of laryngeal pathology based on the videolaryngoscopic examination conducted by experienced otolaryngologists. RESULTS: The mean age of the participants was 43 years. Nearly half of the sample had a diagnosis of pathology, with functional disorders being the most frequent laryngeal pathology. None of the demographic, behavioral, and occupational factors analyzed were statistically associated with laryngeal pathology. Although university teachers do not have an increased risk of laryngeal pathology, self-perceived voice disorders were more prevalent in teachers than in nonteachers. Vocal effort and the number of years teaching have a significant effect on voice disorders prevalence among teachers. CONCLUSIONS: Voice disorders have a higher rate of occurrence among university teachers. Demands of teaching, like vocal effort and years of teaching, and not other demographic and/or behavioral factors, are the risk factors that increase the rate of occurrence of voice disorders among the university teachers. Risk factors that predispose to laryngeal pathology were not detected in the present study. However, the high prevalence of functional laryngeal pathologies underlines the importance of further investigation toward this type of laryngeal pathology in this academic population.

Use of cepstral analyses for differentiating normal from dysphonic voices: a comparative study of connected speech versus sustained vowel in European Portuguese female speakers.

OBJECTIVE: The aim of this study was to investigate the use of cepstral peak prominence (CPP) and CPP-smoothed (CPPs) to differentiate dysphonic from nondysphonic voices, using two speech tasks: sustained vowel /a/ and connected speech. STUDY DESIGN: A retrospective study was based on data selected from an archival database of recorded voices. METHODS: Sixty age- and occupation-matched individuals (30 participants with dysphonia and 30 controls) were recorded producing the sustained vowel /a/ and reading the European Portuguese version of "The Story of Arthur the Rat." Recorded voices were analyzed acoustically by measuring CPP and CPPs and auditory-perceptual ratings were related to the acoustic measurements. RESULTS: For the sustained vowel, both CPP and CPPs measures were significantly different between dysphonic and control groups. For connected speech, only CPP values revealed significant differences between the two groups, both in direct and narrative speech. Acoustic measurements correlated with the auditory-perceptual classifications in both sustained vowel and connected speech, although the strongest correlation (0.6 < r < 0.7) was obtained between CPP and the perception of breathiness. CONCLUSIONS: The results of this study suggest that analysis of CPP and CPPs is a promising tool in clinical practice with European Portuguese speakers.

The regulatory action of estrogen and vasoactive intestinal peptide on prolactin secretion in sea bream (Sparus aurata, L.).

The effect of estradiol-17beta (E(2)) implants on the in vitro secretion of prolactin (PRL) and its modulation by vasoactive intestinal peptide (VIP) in a marine teleost, sea bream (Sparus aurata L.), was determined. Experiments were conducted during winter and spring. During winter, fish (n=130, body weight 50-70 g) were randomly divided into 2 groups; control and E(2) treated (10 mg/kg, wet weight). Fish were sacrificed after 7 days treatment and in vitro pituitary cultures in Ringer bicarbonate supplemented with increasing doses (0-200 nM) of VIP were carried out for 18 h. Culture medium was analysed by PAGE and secreted PRL quantified by densitometry. Fish treated with E(2) secreted significantly more PRL (P<0.05) in vitro than control fish. In E(2) primed fish VIP caused a dose-dependent inhibition of PRL secretion in vitro. VIP had no detectable effect on the secretion of PRL from control pituitaries. Treatment with E(2) had a different effect during spring; PRL secretion was significantly decreased (P<0.01) compared with the control fish. Anatomical evidence of abundant VIP immunoreactive nerve fibres in neurohypophysial (NH) tissue penetrating the rostral pars distalis provide further evidence supporting an action for VIP in the regulation of PRL cells. In conclusion, the responsiveness of PRL in the pituitary gland varied with season. Moreover, in the sea bream VIP appears to modulate PRL secretion from E(2) primed pituitary glands.