High dose irradiation after pleurectomy/decortication or biopsy for pleural mesothelioma treatment.

PURPOSE: The role played by radiation therapy after pleurectomy/decortication or surgical biopsy in malignant pleural mesothelioma is uncertain. We treated patients with accelerated hypofractionated radiotherapy using helical tomotherapy and intensity-modulated arc therapy in an attempt to keep lung toxicity to a minimum. The present study reports the feasibility and toxicity of this approach. MATERIAL AND METHODS: Between 2008 and 2012, 36 patients with malignant pleural mesothelioma underwent accelerated hypofractionated radiotherapy to the hemithorax after pleurectomy/decortication (19 patients) or biopsy (17 patients). The prescription dose was 25Gy in five fractions over 5 consecutive days. RESULTS: We observed three patients with G3 pneumonitis, five cases of grade 2 dyspnea and six cases of grade 2 cough. The median follow-up was 37 months (range: 3-54 months). The median overall survival for patients who underwent pleurectomy/decortication followed by radiotherapy was 21.6 months [95% confidence interval (95% CI): 15.5-24.1] compared to 19.4 months for patients not submitted to surgery. CONCLUSION: Treatment of intact lung with pleural intensity-modulated arc irradiation in malignant pleural mesothelioma patients with malignant pleural mesothelioma proved safe and feasible, with an acceptable rate of pneumonitis. Survival rates were encouraging for both biopsy-only and pleurectomy/decortication groups. We are currently conducting a phase II dose escalation trial in a similar patient setting to prospectively evaluate the impact of radiotherapy on toxicity, disease-free survival and overall survival.

1,25-Dihydroxyvitamin D3 stimulates vascular smooth muscle cell proliferation through a VEGF-mediated pathway.

Atherosclerosis is a complex process characterized by an increase in the wall thickness owing to the accumulation of cells and extracellular matrix between the endothelium and the smooth muscle cell wall. This process is associated with different pathologies and it is accelerated in patients with chronic renal failure. In these patients, decreased synthesis of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) leads to secondary complications, like hyperparathyroidism, and treatment with 1,25(OH)(2)D(3) is a common practice. The effect of 1,25(OH)(2)D(3) on vascular smooth muscle cells (VSMCs) calcification has been widely studied, but the role of 1,25(OH)(2)D(3) on VSMC proliferation remains obscure. We have analyzed the effects of 1,25(OH)(2)D(3) in the proliferation of VSMC. We found that 1,25(OH)(2)D(3) (5-100 nM) induces a dose-dependent increase in VSMC proliferation in quiescent cells and in cells stimulated to grow. This increase in proliferation is achieved by shortening the G1 phase. The effect of 1,25(OH)(2)D(3) on VSMC proliferation is mediated by an increase of the expression of vascular endothelial growth factor A (VEGF), as the inhibition of VEGF activity totally blunted the 1,25(OH)(2) D(3)-induced VSMC proliferation. We found this increase in proliferation in vitro, ex vivo in aortic rings incubated with 1,25(OH)(2)D(3), and in vivo in animals with a model of chronic renal failure (5/6 nephrectomy) treated with 1,25(OH)(2)D(3) (1 mug/kg three times a week for 8 weeks). Thus, we conclude that 1,25(OH)(2)D(3) induces increases in VSMC proliferation through an increase on VEGF expression.

Recurrent intraoral pyogenic granuloma with satellitosis treated with corticosteroids.

The development of recurrent pyogenic granulomas as multiple satellite lesions has not been reported in the oral cavity. This report describes an unusual case of intraoral pyogenic granuloma recurring multiple times after surgical excisions with the formation of satellite lesions. Due to failure of surgical management, an alternative approach was taken. We illustrate how the lesions were successfully treated with a series of intralesional corticosteroid injections.

Degranulation patterns of eosinophils in advanced gastric carcinoma: an electron microscopic study.

Recruitment and activation of eosinophils have been studied intensely in asthma and other allergic diseases. Less is known about the infiltration and degranulation patterns of eosinophils in the tumor stroma. Seven cases of advanced gastric carcinomas were found to be massively infiltrated by eosinophils and studied by light and electron microscopy. Gastric carcinomas, despite having similar numbers of tissue eosinophils, exhibited markedly different degranulation patterns. In 2 cases, resting nondegranulating eosinophils were found. Piecemeal degranulation was the predominant mode of secretion from eosinophils localized within the tumor stroma in 4 cases. Eosinophil exocytosis and cytolysis were rarely observed. In 1 case, crystals morphologically similar to Charcot-Leyden crystals were observed at the extracellular level as well as in phagosomes of tissue macrophages, confirming active sequestrations of eosinophil Charcot-Leyden protein by macrophages in vivo. In the same case, eosinophils showed characteristic features of early and late apoptotic changes, such as condensed chromatin, focal dilatation of nuclear envelope, and preserved plasma membrane. Morphological association between apoptotic eosinophils and deposition of granules in the tumor stroma was found. Extracellular deposition of intact granules from apoptotic eosinophils was distinct from eosinophilic (necrotic) cytolysis, and has reported previously in experimental studies in vitro. To the knowledge of the authors, this case represents the first report of late apoptotic eosinophils that release their granules within the tumor stroma in a human gastric carcinoma.

[Influence of the vitamin D receptor gene polymorphism and 25-hydroxyvitamin D on arterial pressure in health individuals]. / Influencia del polimorfismo del gen receptor de la vitamina D y de la 25-hidroxivitamina D en la tensión arterial de individuos sanos.

UNLABELLED: The role of vitamin D in the regulation of blood pressure is unclear. There are no studies that relate Bsm I polymorphism with blood pressure. OBJECTIVE: To analyze if Bsm I polymorphism and 25-hydroxyvitamin D (25OHD3) influence blood pressure in healthy individuals with normal blood pressure. METHODS: Systolic (SBP) and diastolic (DBP) blood pressure, Body Mass Index (BMI), plasma creatinine, serum calcium, serum phosphorus, serum iPTH, serum 25OHD3 and Bsm I genotype were determined in 590 healthy individuals (260 men and 330 women). Data were analysed using a multiple linear regression model. SBP and DBP were defined as dependent variables and the rest of variables as independent. RESULTS: Gender was strongly associated with both SBP (beta: -12.01, p: 0.000) and DBP (beta: -4.78, p: 0.000). Therefore, a separate analysis was performed according to gender. In males, SBP was associated with BMI (beta: 0.83, p: 0.001), 25OHD3, (beta: 0.36, p: 0.000) and genotype (beta: -3.90, p: 0.002); and DBP with 25OHD 3 (beta: 0.16, p: 0.018) and age (beta: 0.28, p: 0.000). Differences of blood pressure among the three genotypes were explored by analysis of variance. SBP was higher in men with bb genotype than in the other genotypes (p: 0.007). In females, 25OHD3 and genotype were not associated with blood pressure. CONCLUSIONS: Healthy men with higher levels of vitamin D have higher levels of SBP and DBP. Moreover, men with bb genotype have the highest levels of SBP. Blood pressure levels in women are not influenced by vitamin D nor by Bsml genotype. Our data suggest a possible pathophysiological interaction between vitamin D and sex hormones in blood pressure control.

[Differential effect of vitamin D analogues on the proliferation of vascular smooth muscle cells]. / Efecto diferencial de los análogos de la vitamina D en la proliferación de células de músculo liso vascular.

Atherosclerosis is the principal cause of myocardial infarction, stroke, and peripheral vascular disease, accounting for nearly half of all mortality in developed countries. The excessive growth of vascular smooth muscle cells is an important component in the development of atherosclerotic lesion. The direct effect of calcitriol and vitamin D analogs on the VSMCs proliferation is not clear. In this study we have analysed if calcitriol, Paricalcitol (19-nor-1,25-dihydroxy-vitamin D2) and EB1089 (experimental analog used as anticancerous) modify proliferation and the expression of vitamin D receptor (VDR) gene that is regulated at the transcriptional level by itself in the VSMCs. VSMCs proliferation was analysed by BrdU incorporation and VDR gene expression using RT-PCR. VSMCs proliferation was stimulated when calcitriol was added to the culture. VSMCs proliferation was significantly lower with analogs at the same dose. With regard to the functional study, the expression of VDR gene was upregulated by calcitriol at a concentration of 100 nM. There were no changes in this expression with the analogs. In conclusion, calcitriol, do not modify VSMCs proliferation. Therefore, Paricalcitol could have a minor proliferating effect on the wall of vessels that vitamin D.

Influencia del polimorfismo del gen receptor de la vitamina D y de la 25-hidroxivitamina D en la tensión arterial de individuos sanos / Vitamin D receptor genotype and 25 hydroxyvitamin D influence on blood pressure in healthy individuals

El efecto de la vitamina D sobre la tensión arterial (TA) no está bien establecido. No existen estudios que relacionen el polimorfismo del gen del VDR con la TA. Objetivo: Analizar la posible influencia del genotipo Bsm I y de la 25 hidroxivitamina D3 (25OHD3) en la TA en individuos sanos y normotensos. Métodos: Analizamos en 590 individuos sanos (260 varones y 330 mujeres) la posible asociación de la edad, sexo, IMC, creatinina, calcio, fósforo, PTHi, 25OHD3 y genotipo Bsm I con la tensión arterial sistólica (TAS) y diastólica (TAD) mediante un análisis de regresión lineal múltiple. Resultados: El sexo se asoció fuertemente a la TAS (β: –12,01, p: 0,000) y a la TAD (β: –4,78, p: 0,000), por lo que se realizó un análisis multivariante en función del mismo. En varones, la TAS se asoció a: 25OHD3 (β: 0,36, p: 0,000), genotipo (β: –3,90, p: 0,002) e IMC (β: 0,83, p: 0,001); y la TAD a: 25OHD3 (β: 0,16, p: 0,018) y edad (β: 0,28, p: 0,000). El análisis de la varianza mostró que los varones con genotipo bb presentaron una TAS superior al resto de genotipos (p: 0,007). En las mujeres, no encontramos asociación de la 25OHD3 ni del genotipo con la TA. Conclusiones: Los varones con mayores niveles de vitamina D presentan una mayor TAS y TAD. Los varones con genotipo bb tienen una mayor TAS. No existe dicha relación en el sexo femenino. Ello sugiere un posible nexo fisiopatológico entre las hormonas sexuales y la vitamina D en el control de la tensión arterial (AU)

The role of vitamin D in the regulation of blood pressure is unclear. There are no studies that relate Bsm I polymorphism with blood pressure. Objective: To analyze if Bsm I polymorphism and 25-hydroxyvitamin D (25OHD3) influence blood pressure in healthy individuals with normal blood pressure. Methods: Systolic (SBP) and diastolic (DBP) blood pressure, Body Mass Index (BMI), plasma creatinine, serum calcium, serum phosphorus, serum iPTH, serum 25OHD3 and Bsm I genotype were determined in 590 healthy individuals (260 men and 330 women). Data were analysed using a multiple linear regression model. SBP and DBP were defined as dependent variables and the rest of variables as independent. Results: Gender was strongly associated with both SBP (β: –12.01, p: 0.000) and DBP (β: –4.78, p: 0.000). Therefore, a separate analysis was performed according to gender. In males, SBP was associated with BMI (β: 0.83, p: 0.001), 25OHD3 (β: 0.36, p: 0.000) and genotype (β: –3.90, p: 0.002); and DBP with 25OHD3 (β: 0.16, p: 0.018) and age (β: 0.28, p: 0.000). Differences of blood pressure among the three genotypes were explored by analysis of variance. SBP was higher in men with bb genotype than in the other genotypes (p: 0.007). In females, 25OHD3 and genotype were not associated with blood pressure. Conclusions: Healthy men with higher levels of vitamin D have higher levels of SBP and DBP. Moreover, men with bb genotype have the highest levels of SBP. Blood pressure levels in women are not influenced by vitamin D nor by BsmI genotype. Our data suggest a possible pathophysiological interaction between vitamin D and sex hormones in blood pressure control (AU)

Efecto diferencial de los análogos de la vitamina D en la proliferación de células de músculo liso vascular / Vascular and tissue calcifications in haemodialysis patients

Existen datos experimentales contradictorios respecto al comportamiento de las células de músculo liso vascular (CMLV) expuestas al calcitriol. Determinar el efecto del calcitriol y de sus análogos a nivel vascular tiene una considerable trascendencia clínica ya que la proliferación de las CMLV está implicada en el mecanismo patogénico de la arteriosclerosis y de la resistencia tras angioplastia. En este trabajo demostramos mediante incorporación de BrdU que el calcitriol estimula la proliferación en las CMLV. La proliferación es menor al añadir al medio de cultivo Paracalcitol o EB1089 a dosis equimolar. En concordancia con estos hechos, también observamos que el calcitriol induce la expresión del mRNA VDR mientras que no existe este efecto con ninguno de los análogos estudiados. En conclusión, el calcitriol tiene un efecto directo estimulador de la proliferación de las CMLV que no se observa con el Paracalcitol y EB1089 a concentración equimolar (AU)

Atherosclerosis is the principal cause of myocardial infarction, stroke, and peripheral vascular disease, accounting for nearly half of all mortality in developed countries. The excessive growth of vascular smooth muscle cells is an important component in the development of atherosclerotic lesion. The direct effect of calcitriol and vitamin D analogs on the VSMCs proliferation is not clear. In this study we have analysed if calcitriol, Paracalcitol (19-nor-1,25-dihydroxyvitamin D2) and EB1089 (experimental analog used as anticancerous) modify proliferation and the expression of vitamin D receptor (VDR) gene that is regulated at the transcriptional level by itself in the VSMCs. VSMCs proliferation was analysed by BrdU incorporation and VDR gene expression using RT-PCR. VSMCs proliferation was stimulated when calcitriol was added to the culture. VSMCs proliferation was significantly lower with analogs at the same dose. With regard to the functional study, the expression of VDR gene was upregulated by calcitriol at a concentration of 100 nM. There were no changes in this expression with the analogs. In conclusion, calcitriol, do not modify VSMCs proliferation. Therefore, Paracalcitol could have a minor proliferating effect on the wall of vessels that vitamin D (AU)

Identification of cadmium-sensitive genes in the Antarctic fish Chionodraco hamatus by messenger RNA differential display.

To investigate the ability of cadmium to affect gene transcription in fish, the messenger RNA (mRNA) differential display technique was used to analyze gene expression in the Antarctic icefish Chionodraco hamatus exposed to sublethal doses of cadmium salt. Seven DNA complementary to RNA (cDNA) bands whose steady-state levels of expression significantly changed in response to cadmium exposure were identified. The results obtained show that two groups of genes are affected by cadmium in icefish liver. The first group comprises genes that are up-regulated by the metal: in particular, a gene encoding the heat-shock protein HSP70 and another encoding a protein homologous to GP49 of Sparus aurata egg envelope. The other group comprises genes down-regulated by cadmium. These are the transferrin gene and a gene encoding a protein presenting homology to mouse T2K, a kinase having a role in the prevention of apoptosis. Three cDNAs had no homology to known gene sequences, thus suggesting that may either encode not yet identified proteins, or correspond to untranslated regions of mRNA molecules.

Structural and functional analysis of metal regulatory elements in the promoter region of genes encoding metallothionein isoforms in the Antarctic fish Chionodraco hamatus (icefish).

To investigate the regulation of Chionodraco hamatus metallothionein (MT) encoding genes about 1000-bp regions of both MT-I and MT-II gene promoters were cloned and sequenced. Both promoters were rich in A-T content, and lacked the canonical TATA box; several putative cis-regulatory sequences were also present. In the MT-I promoter, four MREs were identified within the first 300 bp from the ATG codon. In the MT-II promoter, seven MREs were organized into two clusters, one containing three MREs located close to the ATG codon, and the other consisting of four MREs lying 500-900 bp upstream of the transcription starting point. The alignment of the MT-I and MT-II promoter regions showed 57% identity, which increased to 87% in the 300-bp region upstream of the ATG. Only the three proximal putative MREs identified were conserved both in position and sequence. Functional analysis of MT-I and MT-II promoters was performed by introducing deletion mutants of the 5'-flanking regions into vector pGL-3, directly upstream of the firefly luciferase reporter gene. Each construct was tested in the HepG2 cell lines in the absence or presence of zinc or cadmium ions. Maximum inducibility of the MT-II gene promoter was achieved with a construct containing both the proximal and the distal MRE clusters. The lack of the most distally located MRE dramatically affected MT-II promoter sensitivity to metals; removal of the distal cluster of MREs also reduced metal inducibility. The MT-I promoter was more compact, since maximal activity and metal inducibility depended on the presence of the proximal cluster of four MREs. This study suggests that the different organization of the MT-I and MT-II gene promoter regions might account for the observed differences in the basal and metal-induced expression of MT-I and MT-II isoforms in the C. hamatus liver.

Molecular cloning, sequence and expression of follicle-stimulating hormone receptor in the lizard Podarcis sicula.

The present paper reports the full nucleotide sequence of a cloned cDNA prepared from RNA of lizard ovaries. The open reading frame consists of 2019 nucleotides, which encodes a protein of 673 amino acids belonging to the G protein-coupled receptor superfamily with a large extracellular N-terminal domain involved in hormone recognition. The transmembrane domain ends with a short intracytoplasmic COOH-terminal domain involved in effector activation. Phylogenetic analysis showed that the lizard receptor belongs to the family of follicle-stimulating hormone (FSH) receptors. The hydrophobicity profile is similar to that observed for mammalian and avian FSH receptors. Northern blot analysis of total RNA revealed that the FSH receptor is expressed at high levels in the ovary. In situ hybridization experiments demonstrate that FSH receptor mRNA is specifically localized within the small cells of the follicular epithelium surrounding the oocyte.

[Importance of dermatologic screening within the frame work of a general cancer prevention program]. / Importanza di uno screening dermatologico nell'ambito di un programma di prevenzione oncolologica generale.

BACKGROUND: Skin tumours represent about 11% of all the malignant neoplasms and their frequency is increasing annually. Skin tumours (melanoma, basal and squamous cell carcinoma, etc.) can be used for a good screening activity, but in relation to breast or cervix uteri cancer needs to be better defined. A test on a population of selected patients against skin malignant neoplasms has been carried out in our Centre. All of them had skin lesions and further checks were necessary. METHODS: The diagnostic protocol used in our Centre for Oncological Prevention uses the collection of anamnestic data and an objective examination. Between 1996 and 2000, 222 patients between the ages of 18 and 80 have been selected. All of them had suspected skin lesions. The patients were selected by the oncologist, particularly for pigmentation, asymmetry, irregular borders and heterogeneous colour of their skin lesions. Subsequently, the patients were sent for a further examination to the dermatologist oncologist, who on the basis of the objective dermatological examination with possible dermatoscopy, made a clinical diagnosis of the skin injuries or suggested surgical removal for the histological control of the same. RESULTS: Requested consultations: 222. Exami-nations made: 195. Patients considered: 190. Skin injuries examined: 190. The following skin lesions were identified: melanoma: 4 (2.1%) [2: I Clark level; 2: II Clark level]; basal cell carcinoma: 14 (7.37%); dermatofibrosarcoma: 1 (0.53%); keratoacanthoma: 1 (0.53%); dysplastic nevus: 4 (2.1%); actinic keratosis: 7 (3.68%); benign lesions: 159 (83.68%). CONCLUSIONS: These data were obtained by a screening program and it is therefore not a random study. This study shows interesting results because tumoral skin lesions and in particular melanoma were recognised at early stages. This is more than enough for us to create a specific screening program for skin lesions to cut down the rate of morbidity and mortality.

Structural characterization and thermal stability of Notothenia coriiceps metallothionein.

Fish and mammalian metallothioneins (MTs) differ in the amino acid residues placed between their conserved cysteines. We have expressed the MT of an Antarctic fish, Notothenia coriiceps, and characterized it by means of multinuclear NMR spectroscopy. Overall, the architecture of the fish MT is very similar to that of mammalian MTs. However, NMR spectroscopy shows that the dynamic behaviour of the two domains is markedly different. With the aid of absorption and CD spectroscopies, we studied the conformational and electronic features of fish and mouse recombinant Cd-MT and the changes produced in these proteins by heating. When the temperature was increased from 20 to 90 degrees C, the Cd-thiolate chromophore absorbance at 254 nm of mouse MT was not modified up to 60 degrees C, whereas the absorbance of fish MT decreased significantly starting from 30 degrees C. The CD spectra also changed quite considerably with temperature, with a gradual decrease of the positive band at 260 nm that was more pronounced for fish than for mouse MT. The differential effect of temperature on fish and mouse MTs may reflect a different stability of metal-thiolate clusters of the two proteins. Such a conclusion is also corroborated by results showing differences in metal mobility between fish and mouse Zn-MT.

Seasonal-dependent effect of temperature on the response of adenylate cyclase to FSH stimulation in the oviparous lizard, Podarcis sicula.

The study of environmental factors affecting vertebrate reproduction has long interested both developmental and evolutionary biologists. Although photoperiod has been considered to be an important environmental parameter for vertebrates such as birds, temperature is probably a primary external factor responsible for reproductive cyclicity in reptiles. In spite of the progress made in the understanding of reptilian reproductive strategies and adaptations, much remains to be learned about the interplay between endocrine physiological factors, such as hormones, and environmental parameters. In this report, we have examined the effects of in vivo administered FSH on oocyte recruitment during the most significant periods of the reproductive cycle of the lizard, Podarcis sicula. The results show that when FSH is administered in proximity to the reproductive period, it stimulates oocyte growth and ovulation; when the hormone is administered at the beginning of the winter stasis it affects ovarian activity without inducing ovulation. Ovarian adenylate cyclase activity is moderately sensitive to in vitro FSH stimulation during the pre- and post-reproductive periods. The sensitivity to hormone stimulation increases significantly during the reproductive period and winter stasis. We have also tested the hypothesis that environmental temperature affects the responsiveness of ovarian adenylate cyclase to FSH stimulation. For such a purpose, we exposed animals to 28 degrees C or 4 degrees C in different periods of the ovarian cycle. The results show that, whenever the temperature applied mimics the thermal regime of the coming season, adenylate cyclase sensitivity to FSH shifts towards levels that anticipate the natural responsiveness.

Zinc transport and metallothionein secretion in the intestinal human cell line Caco-2.

Caco-2, a human cell line, displays several biochemical and morphological characteristics of differentiated enterocytes. Among these is the ability to transport zinc from the apical to the basal compartment. This process was enhanced following exposure by the apical compartment to increasing concentrations of the metal. High pressure liquid chromatography fractionation of the media obtained from cells labeled with radioactive zinc showed that metallothioneins (MTs), small metal-binding, cysteine-rich proteins), were present in the apical and basal media of controls as well as in cells grown in the presence of high concentrations of zinc. Following exposure to the metal, the levels of Zn-MTs in the apical medium increased, while in the basal compartment the greatest part of zinc appeared in a free form with minor changes in the levels of basal MTs. Metabolic labeling experiments with radioactive cysteine confirmed the apical secretion of MTs. A stable transfectant clone of Caco-2 cells (CL11) was selected for its ability to express constitutively high levels of the mouse metallothionein I protein. This cell line showed an enhanced transport of the metal following exposure to high concentrations of zinc and a constitutive secretion of the mouse metallothionein I protein in the apical compartment. Together, these findings strongly support the hypothesis of a functional role between the biosynthesis and secretion of MTs and the transport of zinc in intestinal cells.

Susceptibility to heavy metals and cadmium accumulation in aerobic and anaerobic thermophilic microorganisms isolated from deep-sea hydrothermal vents.

Thirty thermophilic strains isolated from heavy metal-rich hydrothermal vent sites at Lau Basin were tested for their susceptibility to cadmium, zinc, cobalt, and nickel. The 14 aerobic spore formers belonging to the genus Bacillus, 6 anaerobic fermenters from the order Thermotogales, and 10 anaerobic sulfur reducers from the order Thermococcales could be clearly distinguished according to their metal susceptibilities. The Thermococcales were found to exhibit the highest resistance to cadmium and zinc, whereas Thermotogales were highly sensitive to these metals. In contrast, the Thermotogales displayed the highest resistance to cobalt ions. No clear distinction could be established between the metal susceptibilities of these strains and seven reference organisms used for comparative studies. Cadmium resistance, slightly inducible in some cadmium-resistant bacilli, was not plasmid mediated. The amount of cadmium immobilized by the Thermotogales was related to their level of resistance to this metal.

Monaural and binaural loudness measures in cochlear implant users with contralateral residual hearing.

OBJECTIVE: The aim was to measure the loudness of monaural and binaural stimuli in a group of cochlear implant users who had residual hearing in the nonimplanted ear, and to consider the implications of these measures for a binaural fitting consisting of a hearing aid and an implant in opposite ears. Three independent hypotheses were addressed: that the shapes of the electric and acoustic loudness growth functions would be similar, although the dynamic ranges would differ; that standard implant and hearing aid fittings would result in substantial loudness mismatches between the acoustic and electric signals; and that loudness summation would occur for binaural combinations of electric and acoustic signals. DESIGN: A modified version of the "Loudness Growth in 1/2-Octave Bands" method (Allen, Hall, & Jeng, 1990) was used to measure loudness growth for each ear of nine subjects. At the time of the experiment, the subject group included all implant users in Melbourne and Denver who were available for research and who also had sufficient residual hearing to use a hearing aid in the nonimplanted ear. Five acoustic frequencies and five electrodes were measured for each subject. The same subjects also estimated the loudness of a set of stimuli including monaural and binaural signals chosen to cover the loudness range from very soft to loud. RESULTS: The shapes of the averaged loudness growth functions were similar in impaired and electrically stimulated ears, although the shapes of iso-loudness curves were quite different in the two ears, and dynamic ranges varied considerably. Calculations based on the psychophysical data demonstrated that standard fitting procedures for cochlear implants and hearing aids lead to a complex pattern of loudness differences between the ears. A substantial amount of loudness summation was observed for the binaural stimuli, with most summation occurring when the acoustic and electric components were of equal loudness. This is consistent with observations for subjects with normal hearing and subjects with bilaterally impaired hearing. CONCLUSIONS: These experiments provide data on which criteria and methods for the binaural fitting of cochlear implants and hearing aids may be based. It is unlikely that standard monaural fitting methods for cochlear implants and hearing aids will result in balanced loudness between the two ears across a reasonably broad range of frequencies and levels. It is also likely that output levels of both devices will need to be reduced relative to a monaural fitting to compensate for the binaural summation of loudness in some listeners.

Sex- and tissue-specific expression of aspartic proteinases in Danio rerio (zebrafish).

Full-length zebrafish cDNAs encoding two aspartic proteinases were cloned and sequenced. One of the two cDNAs was a 1708 bp product with an open reading frame of 398 amino acid residues corresponding to a cathepsin D. The other was a 1383 bp product encoding a polypeptide chain of 416 amino acids homologous to nothepsin, an aspartic proteinase first identified by us in the liver of Antarctic Notothenioidei. Gene expression assessed by RT-PCR and northern blot hybridization of RNA from different tissues showed that the expression was tissue- and sex-specific. Whereas the cathepsin D gene was expressed in all the tissues examined independently of the sex, the nothepsin gene was expressed exclusively in female livers.