The significance of cortisol on acclimation to salinity in pejerrey Odontesthes bonariensis

The role of cortisol on the osmoregulation of pejerrey Odontesthes bonariensis at different salinities was investigated in adult fish injected with 0.7mg hydrocortisone per 100g body weight of fish, and transferred to 0, 5 and 20ppt of NaCl. Blood cortisol was 566ng/ml at the beginning of the experiment (0h) but surged to 1250ng/ml within 3h in cortisol-injected fish. Cortisol levels were influenced not only by treatment but also by time, being higher at 3h compared to 24h. Salinity level, time of exposure and their interaction, but not cortisol treatment, significantly affected plasma osmolality and the concentration of ions Cl- and Na+. This study showed that exogenous cortisol does not seem to play a significant role on the regulation of plasma osmolality and concentration of individual ions in pejerrey

Investigou-se a participação do cortisol na osmoregulação de peixe-rei Odontesthes bonariensis, em diferentes salinidades, em peixes adultos injetados com 0,7mg hidrocortisona por 100g de peso corporal, e transferidos para 0, 5 e 20ppt de NaCl. No inicio do experimento (0h), o cortisol encontrado no plasma foi de 566ng/ml, aumentando para 1250ng/ml em 3h em peixes injetados com cortisol. A concentração de cortisol foi influenciada não somente pelo tratamento, mas também pelo tempo, sendo maior 3h após a inoculação, comparada à 24h. A salinidade, o tempo de exposição e a interação desses dois fatores, mas não o tratamento com o cortisol, afetaram significativamente a osmolaridade e a concentração dos íons Cl- e Na+ do plasma. Este estudo mostrou que, o cortisol exógeno não influi significativamente na regulação da osmolaridade e da concentração de íons Na+ e Cl- no plasma em peixe-rei

Studies on polishing of Ti and Ag-Pd-Cu-Au alloy with five dental abrasives.

Titanium (Ti) and Ag-Pd-Cu-Au alloy were examined for their polishing behaviour by conducting manually controlled polishing tests using five dental abrasives [carborundum point (CR) and silicone points (R1 and R2)] driven by a high torque micromotor with rotational speeds ranging from 2000 to 15 000 r.p.m. Polishing of Ti resulted in less volume of removal upon polishing, a rougher surface and larger loss of abrasives, compared with polishing of Ag-Pd-Cu-Au alloy. Polishing of Ti with a rotational speed of 15 000 r.p.m. led to the largest volume of removal upon polishing, whilst that of 10 000 r.p.m. produced the optimal volume for Ag-Pd-Cu-Au alloy. It was concluded that Ti was much more difficult to polish, requiring special care (e.g. frequent exchange of abrasives). Development of new abrasives for polishing Ti is required.

Molecular cloning and hormonal control in the ovary of connexin 31.5 mRNA and correlation with the appearance of oocyte maturational competence in red seabream.

Gap junctions are aggregates of intercellular channels, composed of the protein connexin (Cx), between adjacent cells. This study examined whether, in the ovary of the red seabream Pagrus major, the connexin gene essential for the production of RNA and protein during the acquisition of oocyte maturational competence is active. Mixed primers for this reaction were designed on the basis of the high sequence homology of selected regions of known connexin genes. Polymerase-chain-reaction-amplified cDNA fragments generated by 3' and 5' rapid amplication of cDNA ends were combined to generate full-length cDNA sequences. The resulting 2400 base pair cDNA had an open reading frame encoding a polypeptide containing 275 amino acid residues (31493 Da; Cx31.5). Hydropathicity analysis of the predicted amino acid sequence indicated that red seabream Cx31.5 has four major hydrophobic regions and four major hydrophilic regions indicative of a topology similar to that of known connexins. Typical connexin consensus sequences were also observed in the first and second extracellular loops. During the acquisition of oocyte maturational competence, red seabream Cx31.5 mRNA transcription levels increased after treatment with gonadotropin-II. It is therefore proposed that expression of Cx31.5 contributes to the acquisition of oocyte maturational competence in this species.

Cryopreservation of isolated fish blastomeres: effects of cell stage, cryoprotectant concentration, and cooling rate on postthawing survival

The toxicity of the cryoprotectant dimethyl sulfoxide (Me(2)SO) to isolated blastomeres was examined in three fish species representative of distinct environments: marine (whiting, Sillago japonica); estuarine (pejerrey, Odontesthes bonariensis); and freshwater (medaka, Oryzias latipes). The effects of embryonic stage, Me(2)SO concentration, and cooling rate on the cryopreservation of blastomeres were also studied. Whiting sheds small planktonic eggs whereas the other two species shed large demersal eggs. Isolated blastomeres from the three species tolerated Me(2)SO concentrations up to 9% relatively well for over 5 h but lost viability rapidly at 18%. Cells from later embryonic stages (512 or 1024 cells) were more tolerant of Me(2)SO than those from earlier stages (128 or 256 cells). The three factors examined, alone or in combination, had a significant effect on the survival of blastomeres after freezing and thawing, but the extent of the effect and the optimum conditions varied with the species. In general, the highest rates of successful cryopreservation were observed with older rather than younger blastomeres, slower rather than faster cooling, and with 9-18% rather than 0% Me(2)SO. Survival rates for blastomeres cryopreserved under the most effective combination of the three factors examined for each species were 19.9 +/- 10.1% for whiting, 34.1 +/- 8.5% for medaka, and 67.4 +/- 12.8% for pejerrey. Copyright 1999 Academic Press.

Development of a new high-speed measuring system to analyze the dental cast form.

A new non-contact measurement system employing of a line laser and CCD camera was developed to rapidly measure maloccluded dental casts with large depth and high accuracy. In this system, the measuring interval along the line laser and the model scanning direction perpendicular to the line laser were both 0.2 mm. By averaging the raw data through repetitious input and smoothing by local filtering, the noise was effectively decreased. Sub-pixel processing, which calculates the pixel position with the largest brightness within one pixel, improved the accuracy in the measurement to 22 microns compared with 65 microns before sub-pixel processing. Dental casts with malocclusion were measured with this system. The time and the depth for the measurement were about 10 minutes and 60 mm, respectively. This was a vast improvement compared with our previous system employing a point laser. In the CG of the measured dental casts, smooth and detailed surface morphology were sufficiently reproduced, and recognition of the characteristic points in the cast could be accomplished with the accuracy of 30 microns. This measurement system will be helpful to analyze the dental cast form with malocclusion in progress.

Structure and expression of activin genes in rainbow trout.

Activins are dimeric members of the transforming growth factor-beta (TGF-beta) superfamily. By using the polymerase chain reaction (PCR), we have cloned and sequenced activin beta A and beta B genes encoding the mature region of the peptides from the rainbow trout genomic DNA. Two forms of beta A and a single form of beta B-subunits were found. There is high identity with mammalian counterparts; the two rainbow trout beta A-subunits have more than 75% nucleotide sequence identity with the human beta A-subunit, and the beta B-subunit had 82% sequence identity with the human beta B-subunit. Expression of rainbow trout activin genes was examined by reverse transcription-PCR (RT-PCR). The major expression tissue of rainbow trout activin was ovary and brain at the messenger RNA level, and the major expression subunit of rainbow trout activin was the beta B subunit.

Heat-induced germ cell deficiency in the teleosts Odontesthes bonariensis and Patagonina hatcheri.

Pathological or experimental elevation of testicular temperature is known to trigger degeneration and disappearance of germ cells in scrotal mammals. In contrast, there are no reports of heat-induced germ cell deficiency in males of non-scrotal mammals and other vertebrate taxa, nor in females of any species. This study describes the induction of germ cell deficiency up to complete sterility in the teleosts Patagonina hatcheri and Odontesthes bonariensis by rearing larvae and juveniles for prolonged periods at incipient lethal, high temperatures (27-28.5 and 29 degrees C, respectively). It was shown that female germ cells are also heat-sensitive and disappear under high temperatures. The potential implications of these findings for physiological, ecological, and environmental studies and the usefulness of heat-induced germ cell-deficient fish in research and animal production are discussed.

Cloning and characterization of pejerrey mitochondrial DNA and its application for RFLP analysis

Probes were cloned, characterized, and developed for all regions of the mitochondrial DNA (mtDNA) of pejerrey Odontesthes bonariensis to provide the basis for the study of genetic diversity of South American atherinopsinii and to enable species identification from small amounts of tissue. The mtDNA was extracted from liver and cleaved with Eco RI, producing four fragments (7·4, 3·4, 3·1 and 2·9 kb) which were cloned using pUC118 plasmid vectors. Sequence analysis from both ends of the fragments showed that they encode tRNA (Asp, Phe, and Ser-TGA), 12 S rRNA, cytochrome oxidase (CO) II, NADH 4, 5, and 6, and the d-loop, and that the relative positions of these genes are identical to those in the mtDNA of other teleosts. A comparison of homology with carp mtDNA nucleotide sequences revealed that tRNA (Phe and Ser-TGA) and CO II were relatively conserved, whereas the d-loop region was highly divergent. The cloned mtDNA probes detected mtDNA fragments from about 800 ng of total DNA extracted from liver, muscle, and single embryos of O. bonariensis, and were effective for restriction length fragment polymorphism (RFLP) analysis of Patagonina hatcheri, the most distant atherinopsine relative of pejerrey. The cloned mtDNA probes may be useful for the analysis of genetic diversity and non-destructive species identification, including the examin-ation of eggs, larvae and juveniles. The mtDNA sequences reported here provide the basis for the design of primers for PCR-based RFLP analysis. 1997 The Fisheries Society of the British Isles

Cloning and sequencing of cDNAs of the ß-globin gene family in carp.

A total blood cell cDNA library was constructed using a 3-year-old carp Cyprinus carpio. A ß-globin cDNA (CßG1) was identified from the library by the polymerase chain reaction using a ß-globin-specific primer deduced from the carp ß-globin-A amino acid sequence. Also, five additional types of ß-globin cDNAs (CßG2∼6) were isolated by colony hybridization using CßG1 as a probe. Sequence analysis revealed that these CßGs encoded 147 amino acids, and the deduced amino acid sequences showed high identity (89·1-95·2%) to previously reported carp ß-globin amino acid sequences. The nucleotide sequences of the CßGs were very similar (identity 96·0-99·6%) and the expression levels of CßG1∼6 were 28·6, 28·6, 21·4, 14·3, 3·6 and 3·6% of the total number of cloned CßGs, respectively. Although the complete amino acid sequence identities between the CßGs and the ß-globin of higher vertebrates were low, functionally important regions such as the α-ßcontact region and haem contact region were well conserved. These data showed that, as in higher vertebrates, the adult carp has a multiple ß-globin gene family (at least six members). However, transcripts encoding four types of peptides (CßG1 type, CßG2 and 3 type, CßG5 type, and CßG4 and 6 type) were expressed at relatively high levels, this being a unique character of the carp haemoglobin system.

Development of the computerized dental cast form analyzing system--three dimensional diagnosis of dental arch form and the investigation of measuring condition.

To analyze the functional and morphological harmonies of the tooth and dental arch, a computerized system to measure a dental cast and to detect the apex of dental cusps and angle points of incisors was developed. Detailed morphology in the measured dental cast could be displayed distinctively by computer graphics (CG) with a surface model. Accuracy in determining the position of the apex of the dental cusp was examined by increasing the measuring pitch from 50 microns to 400 microns, the error increased gradually with increased measuring pitch. Taking the measuring error, the time for measurement and the memory size for analysis into account, a measuring pitch of 200 microns was determined to be reasonable. Three-dimensional data measurements from the apex of the dental cusp in molar, and the mesial and distal angles in canine and incisor were fitted to a polynomial formula. In the present measured model, the 4th order polynomial formula was used for the dental arch, and the 2nd order polynomial formula was used for the anteroposterior and lateral occlusal curves. These formulae could be simultaneously superimposed on the surface model of the dental cast, and displayed using CG.

A highly repetitive sequence isolated from genomic DNA of the medaka (Oryzias latipes).

A highly repetitive interspersed DNA sequence (MRE) was isolated from the genome of medaka, Oryzias latipes, and characterized. Three distinct sequences of MRE were cloned and compared. The conserved sequences of MRE were approximately 220 bp in length. On average, one copy of MRE was present in every 153 kb, and the number of copies of MRE in the genome was calculated to be approximately 9800. MRE constituted approximately 0.14% of the genome. MRE-related sequences were not detected in carp (Cyprinus carpio) red-spot masu trout (Oncorhynchus masou macrostomus), masu salmon (Oncorhynchus masou masou), rainbow trout (Oncorhynchus mykiss), eel (Anguilla japonica), Arctic lamprey (Lampetera japonica), or yellowtail (Seriola quinqueradiata). MRE was randomly distributed in the medaka genome, indicating a high incidence of polymorphism in the five medaka inbred lines.

Effect of the location of chewing on facial and jaw muscles activity and the mandibular movement.

This paper evaluates the influence of the location of chewing on facial and jaw muscles' activity and mandibular movements. Ten subjects with complete dentition performed following chewing sequences; 1) right side chewing (unilateral location-unspecified chewing); 2) chewing on right molars; 3) chewing on right premolars; and 4) chewing on anterior teeth. Bilateral activities of upper lip, cheek, masseter (anterior, middle and posterior parts), and anterior bellies of digastrics were recorded by surface electromyography. Mandibular movements were simultaneously recorded by electrognathography. Chewing on anterior teeth showed smaller masseteric activity in posterior part, smaller envelope of motion, and lower velocity of both opening and closing than unilateral location-unspecified chewing and chewing on right molars. Chewing on premolars showed smaller envelope of motion than chewing on molars. No significant difference was found between unilateral location-unspecified chewing and chewing on premolars or molars.

Olfactory responses of several species of teleost to F-prostaglandins.

Olfactory responses (EOG: electro-olfactogram) of 11 species of teleost (five Cypriniformes and six non-Cypriniformes) to F-prostaglandins (PGF2 alpha, 15-keto-PGF2 alpha, 13,14-dihydro-15-keto-PGF2 alpha) were examined. All the Cypriniformes showed distinct EOG responses to F-prostaglandins at 10(-7) M. By contrast, non-Cypriniformes with the exception of ayu, Pleccoglossus altivelis, showed responses to 10(-7) M F-prostaglandins of < 22% of that to 10(-5) M L-serine, and they were anosmic to 10(-8) M F-prostaglandins. These results indicate that F-prostaglandins are potent chemical stimulants in Cypriniformes, and suggest that F-prostaglandins may be commonly used as sex pheromones in Cypriniformes, whereas they seem not to have pheromonal functions in most non-Cypriniformes examined.

The relationship between the mandibular movements during speech and specific types of malocclusions.

To investigate the effect of malocclusion on mandibular movements during speech, the location, width and height of the envelope of motion during speech were analyzed in 25 normal subjects and 60 subjects with malocclusion using the Sirognathograph Analyszing System. Location of the envelope of motion was closely related to the specific types of malocclusions. It is suggested that the analysis of the envelope of motion during speech has diagnostic values in speech function and dental treatments.

Crow-Fukase syndrome associated with pulmonary hypertension.

A 60-year-old woman suffering from heart failure was found to have Crow-Fukase syndrome. A precise cardiovascular study revealed the existence of pulmonary hypertension (PH), cardiomegaly and myocardial hypertrophy in addition to manifestations of this syndrome such as hyperpigmentation, hypertrichosis, finger clubbing, polyneuropathy, organomegaly and plasma cell dyscrasia. These findings suggest the possibility that patients with Crow-Fukase syndrome have cardiopulmonary disorders including PH and cardiomegaly which might cause some cardiovascular symptoms such as peripheral edema and finger clubbing.

Subunit structure of multiple hemoglobins in carp.

Three hemoglobin components in carp designated CI, CII, and CIII, were isolated by DEAE-Tokyo-pearl ion-exchange chromatography. Constituent globin chains, alpha 1, alpha 2, beta 1, and beta 2, were analyzed by urea-Triton acid polyacrylamide gel electrophoresis and isolated by high performance liquid chromatography with a reverse-phase column. Tryptic peptide mapping indicated that the alpha-globin chains of the three hemoglobin components have slightly different structures. In addition, N-terminal amino acid sequence analysis indicated that the beta 1-globin chain has a primary structure different from that of the beta 2-chain. A series of hybridization experiments between isolated hemoglobins, together with such structural properties of globin chains, suggested that the three hemoglobins have the following compositions: CI (alpha 1 alpha 2 beta 1(2)), CII (alpha 1 alpha 2 beta 1 beta 2), and CIII (alpha 1 alpha 2 beta 2(2)). Hemoglobin CII was a hybrid between the two types each of alpha- and beta-chain and could be constructed in vitro from two hemoglobin components CI and CIII.

Histological study on bone response to resin-hydroxyapatite.

Resin-Hydroxyapatite has been developed to take the advantages of bioactivity of hydroxyapatite (HAP) and plasticity of resin (Bis-GMA). It was composed of 75% HAP, 15% Bis-GMA and 10% quartz reinforced filler. Tested pellets of Resin-HAP as well as its constituents were implanted into subcutaneous connective tissue of femurs of adult dogs. Histological observation at 12 weeks postoperatively showed that each pellet was surrounded by the fibrous connective tissue almost free of the inflammatory cells. The thickness of the fibrous layer around HAP was relatively thin, while those around Bis-GMA and Resin-HAP showed some variance. Taking our previous data into consideration, it was suggested that Resin-HAP had bio-compatibility both in soft tissue and bone, although its long-term stability as well as its stability under function should further be examined.