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1.
Dysphagia ; 37(6): 1757-1768, 2022 12.
Article in English | MEDLINE | ID: mdl-35415813

ABSTRACT

We examined factors related to dietary intake status (food form) of long-term care facility (LTCF) residents to identify factors related to proper food form choice for older individuals requiring nursing care. We surveyed 888 residents from 37 LTCFs in Japan. We evaluated basic information (age, sex, body mass index [BMI]), food form (swallowing-adjusted diet class), Barthel Index (BI), Clinical Dementia Rating (CDR), simply evaluated eating and swallowing functions, the number of present/functional teeth, oral diadochokinesis, repetitive saliva swallowing test (RSST), and modified water swallowing test. To clarify factors associated with food form, participants who had good nutrition by oral intake were categorized into the dysphagic diet (DD) and normal diet (ND) groups. Multi-level analyses were used to detect oral functions associated with food form status. Among objective assessments, BMI (odds ratio [OR] 0.979, 95% confidence interval [CI] - 0.022- to 0.006, p = 0.001), BI (OR 0.993, 95% CI - 0.007 to - 0.004, p < 0.001), CDR 3.0 (OR 1.002, 95% CI 0.002‒0.236, p = 0.046), present teeth (OR 0.993, 95% CI - 0.007 to - 0.001, p = 0.011), functional teeth (OR 0.989, 95% CI - 0.011 to - 0.005, p < 0.001), and RSST (OR 0.960, 95% CI - 0.041 to - 0.007, p = 0.006) were significantly associated with DD vs ND discrimination. Simple evaluations of coughing (OR 1.056, 0.054‒0.198, p = 0.001) and rinsing (OR 1.010, 0.010‒0.174, p = 0.029) could also discriminate food form status. These simple evaluations provide insight into the discrepancies between food form status and eating abilities of LTCF residents. Periodic evaluations by the nursing caregiver may help to prevent aspiration by older individuals with dysphagia.


Subject(s)
Deglutition Disorders , Insurance, Long-Term Care , Humans , Deglutition , Deglutition Disorders/diagnosis , Nutritional Status , Eating , Long-Term Care
2.
Gerodontology ; 39(3): 273-281, 2022 Sep.
Article in English | MEDLINE | ID: mdl-34240454

ABSTRACT

BACKGROUND: Currently, patients with dysphagia are receiving dietary management that deviates from their original swallowing function. OBJECTIVE: To evaluate the clinical significance of fibreoptic endoscopic evaluation of swallowing (FEES) and dietary intervention (DI) by multi-professional collaboration during visit care for determining the actual oral intake status in patients with dysphagia. METHODS: Five hundred and eighteen patients with dysphagia underwent FEES, focusing on the penetration-aspiration scale, and DI. Oral intake status was categorised using the functional oral intake scale (FOIS). FOIS scores at the first visit, after FEES, and at the reassessment were compared. RESULTS: At the first visit, 34.7% of the patients had an FOIS score of level 1 (no oral intake) and 65.3% had a score of level 2 or higher (capable of oral intake). Following FEES, 7.1% of patients had an FOIS score of level 1, and 44.4% had a score of level 2 with resumption of oral intake. At the reassessment, 489 patients (94.4%) were capable of oral ingestion (FOIS level 2 or higher). There were significant differences between the distributions of FOIS scores at the first visit and following FEES (P < .01) and between those at the first visit and at the reassessment (P < .01). Regarding tube feeding, 17 (5.9%) of 289 patients, who had received tube feeding at the first visit, were completely capable of oral intake following FEES and at the reassessment. CONCLUSION: Appropriate evaluation of swallowing function using FEES and DI helps to understand the definite swallowing function in patients with dysphagia.


Subject(s)
Deglutition Disorders , Deglutition , Aged , Deglutition Disorders/diagnosis , Dental Care , Enteral Nutrition , Humans
3.
Theriogenology ; 133: 210-215, 2019 Jul 15.
Article in English | MEDLINE | ID: mdl-31155036

ABSTRACT

The eels are teleost fishes from the order Anguilliformes that includes several species with high commercial value. Due to the high interest for aquaculture production of some eel species and for the need to restore eel species that are endangered, several research groups have directed their research toward developing protocols to cryopreserve the spermatozoa of Japanese eel (Anguilla japonica) and European eel (Anguilla anguilla). In this review, we provide an overview on the different protocols that have been developed so far. The first developed protocols used DMSO as cryoprotectant in both species with good success, obtaining sperm motilities of over 45% in Japanese eel and over 35% in European eel. Moreover, sperm cryopreserved using DMSO was successfully used in fertilization trials, although with low fertilization rates. However, recent studies show that DMSO produce epigenetic changes in eel sperm and therefore, the last developed protocols used methanol as cryoprotectant instead. Cryopreservation protocols using methanol as cryoprotectant, showed improved motility values in both Japanese and European eel. In addition, the latest protocols have been adapted to cryopreserve larger volumes of sperm of up to 5 mL, which is useful for larger scale fertilization trials. The present study introduces the state of the art and future perspectives of the eel sperm cryopreservation to be applied in aquaculture and biological conservation programs.


Subject(s)
Anguilla/physiology , Semen Preservation/veterinary , Spermatozoa/physiology , Animals , Cryopreservation/methods , Cryopreservation/veterinary , Male , Semen Preservation/methods , Vitrification
4.
Gen Comp Endocrinol ; 194: 300-10, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24100168

ABSTRACT

We studied the profiles of thyroid hormone receptors (TRs) in Japanese eels (Anguilla japonica) during development from hatched larvae to juveniles. Two TRαs (TRαA and TRαB) and one TRß (TRßA) cDNA clones were generated by RACE. The TRαA, TRαB and TRßA cDNAs encoded 416, 407 and 397 amino acid proteins with much higher homologies to the Japanese conger eel (Conger myriaster) TRs than to other fish TRs. In a transiently transfected Japanese eel cell line, Hepa-E1, the TRs showed thyroid hormone (TH)-dependent activation of transcription from the TH-responsive promoter. Four TR cDNA clones, including TRßB reported in a previous study, were analyzed by real-time RT-PCR. The TR mRNA levels in hatched larvae were determined. The two TRß mRNAs were present at low levels but there was a peak in the TRαs during the larval stage before metamorphosis. During metamorphosis, the two TRαs both exhibited peaks and expression of the two TRßs was higher than during the early growth stage. This expression pattern is similar to that of the Japanese conger eel. It is possible that thyroid hormones control the early development of Japanese eels and Japanese conger eels through TRs. This is the first analysis of the expression sequence of TRs during early larval stages of Anguilliformes.


Subject(s)
Eels/metabolism , Receptors, Thyroid Hormone/genetics , Receptors, Thyroid Hormone/metabolism , Thyroid Hormones/genetics , Animals , Eels/genetics , Larva/genetics , Larva/metabolism , Male , Metamorphosis, Biological/genetics , Metamorphosis, Biological/physiology , Promoter Regions, Genetic/genetics
5.
Zygote ; 20(1): 79-85, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21106134

ABSTRACT

The viability of ornamental fish culture relies on the maintenance of high-quality breeds. To improve the profitability of culture operations we attempted to produce cloned fish from the somatic nucleus of the high-quality Japanese goldfish (Carassius auratus auratus) breed 'Ranchu'. We transplanted the nucleus of a cultured fin-cell from an adult Ranchu into the non-enucleated egg of the original goldfish breed 'Wakin'. Of the 2323 eggs we treated, 802 underwent cleavage, 321 reached the blastula stage, and 51 reached the gastrula stage. Two of the gastrulas developed until the hatching stage. A considerable number of nuclear transplants retained only the donor nucleus. Some of these had only a 2n nucleus derived from the same donor fish. Our results provide insights into the process of somatic cell nuclear transplantation in teleosts, and the cloning of Ranchu.


Subject(s)
Cell Nucleus/metabolism , Cloning, Organism/methods , Genetic Engineering/methods , Goldfish/genetics , Nuclear Transfer Techniques , Animals , Animals, Genetically Modified , Cell Nucleus/genetics , Embryo, Nonmammalian/cytology , Embryo, Nonmammalian/embryology , Embryo, Nonmammalian/metabolism , Embryonic Development , Female , Gene Expression Regulation, Developmental , Goldfish/embryology , Goldfish/metabolism , Male , Ovum/cytology , Ovum/metabolism , Polyploidy , Random Amplified Polymorphic DNA Technique
6.
Biol Bull ; 221(2): 227-37, 2011 Oct.
Article in English | MEDLINE | ID: mdl-22042441

ABSTRACT

Sea urchins of both sexes store the nutrients necessary for gametogenesis in nutritive phagocytes of the agametogenic gonad. A zinc-binding protein termed the major yolk protein (MYP) is stored here as two isoforms: the egg-type (predominant in egg yolk granules) and the coelomic fluid-type (a precursor with greater zinc-binding capacity). MYP is used during gametogenesis as material for synthesizing gametic proteins and other components. We investigated its accumulation and relationship to zinc contents in gonads during the non-reproductive season in Pseudocentrotus depressus. MYP constituted most of the protein in coelomic fluid and gonads. Both ovaries and testes grew gradually, accumulating MYP and zinc during the year. Total zinc contents and the ratio of coelomic fluid-type to egg-type protein were higher in ovaries than in testes as gametogenesis approached. Most of the zinc in the coelomic fluid was bound to MYP, and the concentrations of MYP and zinc were elevated toward the onset of oogenesis in the female coelomic fluid. Thus, MYP accumulates in the agametogenic ovaries and testes during the non-reproductive season, playing a role as a carrier to transport zinc to the gonad. Transportation of zinc by MYP is more active in females than in males.


Subject(s)
Egg Proteins/metabolism , Phagocytes/metabolism , Sea Urchins/physiology , Zinc/metabolism , Animals , Female , Gonads/metabolism , Male , Protein Binding , Sea Urchins/metabolism
7.
Mol Ecol Resour ; 11(5): 802-7, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21518301

ABSTRACT

Species and sex identification are among the most important parameters for conservation management. However, it is extremely difficult to perform such identification in Formosa landlocked salmon (Oncorhynchus masou formosanus). Both sexual dimorphism in landlocked dwarf form Formosa landlocked salmon and morphological difference among cherry salmon complex are minimal. We developed a simple, rapid and noninvasive method for identifying sex and species of this critically endangered species using a loop-mediated isothermal amplification (LAMP) technique. The LAMP assay showed the advantage of simple detection (evaluated by visual inspection), rapid reaction time (< 1 h), isothermal condition (less equipment required) and high efficiency (only 0.5-5 pg of DNA was required in the reaction mixture). Therefore, the method is more economical and practical than PCR. The LAMP assay can be easily performed in the field and is a valuable tool for detecting sex ratios in wild populations and identifying species in commercial imports. This is the first application of LAMP in identifying species and sex of salmonids as far as we know and clearly shows the potential application of LAMP in molecular ecology and conservation efforts.


Subject(s)
Conservation of Natural Resources/methods , Nucleic Acid Amplification Techniques/methods , Oncorhynchus/genetics , Animals , DNA Primers/genetics , Electrophoresis, Agar Gel , Sensitivity and Specificity , Sex Determination Analysis , Species Specificity , Taiwan
8.
Cryobiology ; 61(3): 263-7, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20869362

ABSTRACT

In the present study, we examined methods for the cryopreservation of Epinephelus septemfasciatus spermatozoa. The percent motility, average path velocity, and linearity of movement (LIN) of fresh and corresponding post-thaw sperm were evaluated. Sperm motility was investigated using computer-assisted sperm analysis. Five percent dimethyl sulphoxide (Me2SO) with 95% fetal bovine serum (FBS) was the most successful cryoprotectant diluent with a comparative post-thaw motility of 77.6±8.5%; 5% dimethyl formamide was also effective. Fetal bovine serum was significantly better as an extender when compared with artificial seminal plasma, glucose, and trehalose solution. Sperm tolerated a wide range of cooling rates (from 27.1 to 94.3 °C min⁻¹); however, the post-thaw motility of sperm cooled to -30 °C was significantly lower than that of other cooled temperatures (-40 to -70 °C). The velocity of post-thaw sperm was significantly lower than that of fresh sperm, although LIN remained the same. For effective cryopreservation of seven-band grouper sperm, samples should be diluted in 5% Me2SO with 95% FBS and cooled to at least -40 °C before immersion in liquid nitrogen.


Subject(s)
Cryopreservation/veterinary , Semen Preservation/veterinary , Animals , Aquaculture/methods , Bass , Cattle , Cryopreservation/methods , Dimethyl Sulfoxide/pharmacology , Dimethylformamide/pharmacology , Fetal Blood/physiology , Male , Semen Preservation/methods , Sperm Motility , Spermatozoa/drug effects
9.
Mol Reprod Dev ; 76(2): 142-50, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18500722

ABSTRACT

Major yolk protein (MYP), a transferrin superfamily protein contained in yolk granules of sea urchin eggs, also occurs in the coelomic fluid of male and female adult sea urchins regardless of their reproductive cycle. MYP in the coelomic fluid (CFMYP; 180 kDa) has a zinc-binding capacity and has a higher molecular mass than MYP in eggs (EGMYP; 170 kDa). CFMYP is thought to be synthesized in the digestive tract and secreted into the coelomic fluid where it is involved in the transport of zinc derived from food. To clarify when and where MYP synthesis starts, we investigated the expression of MYP during larval development and growth in Pseudocentrotus depressus. MYP mRNA was detected using RT-PCR in the early 8-arm pluteus stage and its expression persisted until after metamorphosis. Real-time RT-PCR revealed that MYP mRNA increased exponentially from the early 8-arm stage to metamorphosis. Western blotting showed that maternal EGMYP disappeared by the 4-arm stage and that newly synthesized CFMYP was present at and after the mid 8-arm stage. In the late 8-arm larvae, MYP mRNA was detected in the digestive tract using in situ hybridization, and the protein was found in the somatocoel and the blastocoel-derived space between the somatocoel and epidermis using immunohistochemistry. These results suggest that CFMYP is synthesized in the digestive tract and secreted into the body cavities at and after the early 8-arm stage. We assume that in larvae, CFMYP transports zinc derived from food via the body cavities to various tissues, as suggested for adults.


Subject(s)
Egg Proteins/biosynthesis , Egg Proteins/metabolism , Gastrointestinal Tract/metabolism , Gene Expression Regulation, Developmental/physiology , Sea Urchins/metabolism , Transferrin/metabolism , Animals , Blotting, Western , Immunohistochemistry , In Situ Hybridization , Larva/metabolism
10.
Res Lett Biochem ; 2009: 251731, 2009.
Article in English | MEDLINE | ID: mdl-22820749

ABSTRACT

Hyaluronan (HA) is a linear polysaccharide of high molecular weight that exists as a component of the extracellular matrix. The larvae (leptocephali) of the Japanese conger eel (Anguilliformes: Conger myriaster) have high levels of hyaluronan (HA) which is thought to help control body water content. We isolated glycosaminoglycans (GAGs) from Japanese conger eel leptocephali and measured the changes in tissue HA content during metamorphosis. HA content decreased during metamorphosis. In contrast, neutral sugar content increased during metamorphosis. We hypothesize that the leptocephali utilize a metabolic pathway that converts HA to glucose during metamorphosis. Glucose may then be metabolized to glycogen and stored in the juvenile life-history stage.

11.
Hypertens Res ; 31(11): 2019-25, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19098373

ABSTRACT

We examined the relationship of several cardiovascular disease (CVD) risk factors to flow-mediated vasodilatation of the brachial artery (FMD) and the clustering effect of risk factors on FMD in Japanese subjects free of CVD. In 819 Japanese subjects free of CVD (age 45+/-10 years, 611 men and 208 women), FMD correlated significantly with the Framingham risk points score (FRS) (r=-0.27, p<0.01). FMD was higher in subjects in the 1st tertile of the FRS range than in patients in either the 2nd or 3rd tertiles of the FRS range, but it was similar between the subjects in the 2nd and 3rd tertiles. FMD was found to have a significant independent negative correlation with age (beta=-0.19, p<0.01), gender (beta=-0.024, p<0.01) and smoking habit (beta=-0.08, p=0.02). In subjects >or=50 years of age, the FMD in men with one CVD risk factor, excluding smoking, was similar to that in men with no CVD risk factors. CVD risk factors did not attenuate FMD in women. Thus, in Japanese subjects free of CVD, FMD may be a useful marker of CVD risk, but it may not be a robust marker for endothelial damage related to clusters of CVD risk factors. Age, gender and smoking were independent variables related to the impairment of FMD, which therefore appears to be less applicable in subjects aged 50 or more, and especially in women. (Hypertens Res 2008; 31: 2019-2025).


Subject(s)
Brachial Artery/physiology , Cardiovascular Diseases/etiology , Vasodilation , Adult , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Regional Blood Flow , Risk Factors
12.
Article in English | MEDLINE | ID: mdl-18387327

ABSTRACT

Thyroid hormones (THs) are essential for the embryonic and post-embryonic development of fish. We studied the role of THs during the early, post-embryonic, development of Pacific bluefin tuna. Embryos were treated with L-thyroxine (T(4)) or the anti-thyroid drug methimazole (MMI), and reared in microtitre plates for 3 days. Immersion in MMI, but not T(4), led to retardation of retinal pigment epithelium (RPE) pigmentation 3 days post-hatching (dph). Concurrent immersion in T(4) and MMI had no effect of RPE pigmentation. We also measured the expression of TRalphaA, TRalphaB, and TRbeta mRNA using real-time RT-PCR. Treatment with MMI significantly reduced TRbeta mRNA expression. Taken together these results suggest that the development of RPE pigmentation is mediated by TH, most likely via TRbeta.


Subject(s)
Eye/drug effects , Eye/metabolism , Pigmentation/drug effects , Thyroxine/pharmacology , Tuna/metabolism , Animals , Breeding , Gene Expression Regulation/drug effects , Methimazole/pharmacology , Pigment Epithelium of Eye/cytology , Pigment Epithelium of Eye/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Thyroid Hormone/genetics , Receptors, Thyroid Hormone/metabolism , Survival Analysis , Tuna/growth & development
13.
Gen Comp Endocrinol ; 155(3): 597-606, 2008 Feb 01.
Article in English | MEDLINE | ID: mdl-17988667

ABSTRACT

We studied the profiles of 3,5,3'-l-triiodothyronine (T3), thyroxine (T4), and thyroid hormone receptors (TRs) in Pacific bluefin tuna (Thunnus orientalis) during embryonic and post-embryonic development. Both T3 and T4 were detected in embryos just before hatching, and it was found that the levels of both were increased in postflexion fish. The thyroid follicles were increased in both size and number in postflexion fish compared with preflexion fish. A TRbeta cDNA clone was generated by RACE. Two TRalpha cDNA clones were also partially identified and analyzed by real-time RT-PCR in this study. The TR mRNA levels in embryos were determined, and these were found to be lower than those in preflexion fish. Therefore, we considered that thyroid hormones function during early post-embryonic development as well as during embryonic development. Moreover, there was a peak in the TR mRNA level during postflexion stages, as seen during metamorphosis in Japanese flounder and Japanese conger eel. It is possible that thyroid hormones control the early development of scombrid fish through TRs, as they do for Pluronectiformes and Anguilliformes.


Subject(s)
Receptors, Thyroid Hormone/genetics , Thyroid Hormones/metabolism , Tuna/growth & development , Tuna/genetics , Amino Acid Sequence , Animals , Base Sequence , DNA, Complementary/isolation & purification , DNA, Complementary/metabolism , Embryo, Nonmammalian , Gene Expression Regulation, Developmental , Life Cycle Stages/genetics , Life Cycle Stages/physiology , Models, Biological , Molecular Sequence Data , Phylogeny , Sequence Homology, Amino Acid , Thyroid Gland/anatomy & histology , Thyroid Gland/embryology , Thyroid Gland/growth & development , Time Factors , Tuna/embryology , Tuna/metabolism
14.
Int J Biometeorol ; 52(5): 331-40, 2008 May.
Article in English | MEDLINE | ID: mdl-17957390

ABSTRACT

We investigated the effects of redecoration of a hospital isolation room with natural materials on thermoregulatory, cardiovascular and hormonal parameters of healthy subjects staying in the room. Two isolation rooms with almost bilaterally-symmetrical arrangements were used. One room (RD) was redecorated with wood paneling and Japanese paper, while the other (CN) was unchanged (with concrete walls). Seven healthy male subjects stayed in each room for over 24 h in the cold season. Their rectal temperature (T(re)) and heart rate, and the room temperature (T(a)) and relative humidity were continuously measured. Arterial blood pressures, arterial vascular compliance, thermal sensation and thermal comfort were measured every 4 h except during sleeping. Blood was sampled after the stay in the rooms. In RD, T(a) was significantly higher by about 0.4 degrees C and relative humidity was lower by about 5% than in CN. Diurnal T(re) levels of subjects in RD significantly differed from those in CN, i.e., T(re)s were significantly higher in RD than in CN especially in the evening. In RD, the subjects felt more thermally-comfortable than in CN. Redecoration had minimal effects on cardiovascular parameters. Plasma levels of catecholamines and antidiuretic hormone did not differ, while plasma cortisol level was significantly lower after staying in RD than in CN by nearly 20%. The results indicate that, in the cold season, redecoration with natural materials improves the thermal environment of the room and contributes to maintaining core temperature of denizens at preferable levels. It also seems that redecoration of room could attenuate stress levels of isolated subjects.


Subject(s)
Hospital Design and Construction/methods , Patient Isolation/psychology , Stress, Physiological/prevention & control , Adult , Blood Pressure , Body Temperature Regulation , Cold Climate , Heart Rate , Humans , Hydrocortisone/blood , Male , Stress, Physiological/physiopathology
15.
FEBS J ; 274(19): 4985-98, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17760878

ABSTRACT

Major yolk protein (MYP), a transferrin superfamily protein that forms yolk granules in sea urchin eggs, is also contained in the coelomic fluid and nutritive phagocytes of the gonad in both sexes. MYP in the coelomic fluid (CFMYP; 180 kDa) has a higher molecular mass than MYP in eggs (EGMYP; 170 kDa). Here we show that MYP has a zinc-binding capacity that is diminished concomitantly with its incorporation from the coelomic fluid into the gonad in the sea urchin Pseudocentrotus depressus. Most of the zinc in the coelomic fluid was bound to CFMYP, whereas zinc in eggs was scarcely bound to EGMYP. Both CFMYP and EGMYP were present in nutritive phagocytes, where CFMYP bound more zinc than EGMYP. Saturation binding assays revealed that CFMYP has more zinc-binding sites than EGMYP. Labeled CFMYP injected into the coelom was incorporated into ovarian and testicular nutritive phagocytes and vitellogenic oocytes, and the molecular mass of part of the incorporated CFMYP shifted to 170 kDa. Considering the fact that the digestive tract is a major production site of MYP, we propose that CFMYP transports zinc, essential for gametogenesis, from the digestive tract to the ovary and testis through the coelomic fluid, after which part of the CFMYP is processed to EGMYP with loss of zinc-binding site(s).


Subject(s)
Egg Proteins/metabolism , Egg Proteins/physiology , Gametogenesis/physiology , Zinc/metabolism , Animals , Blotting, Western , Chromatography, Gel , Egg Proteins/isolation & purification , Electrophoresis, Polyacrylamide Gel , Protein Binding , Protein Transport , Sea Urchins
16.
Cryobiology ; 54(1): 19-26, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17174293

ABSTRACT

In order to develop cryopreservation techniques for Japanese pearl oyster spermatozoa, the effects of various cryopreservation conditions on post-thaw motility were examined. Spermatozoa cryopreserved with 10% methanol (MET), dimethylformamide or dimethylacetamide plus 90% diluent comprising 80% seawater and 20% fetal bovine serum (FBS) showed higher percentages of post-thaw motility than those cryopreserved with 10% dimethylsulfoxide or glycerol. When spermatozoa were cryopreserved with various concentrations (0-20%) of MET and 100-80% diluent, 10% MET showed the highest percentages of post-thaw motility. When spermatozoa were cryopreserved with 10% MET and 90% diluent comprising various concentrations (0-100%) of FBS or Ringer solution mixed with seawater, the percentages of post-thaw motility peaked at 20% FBS or Ringer solution, and were significantly higher for 20% FBS than for 20% Ringer solution. The percentages of post-thaw motility increased with increasing dilution ratios from 2.5- to 50-fold. Spermatozoa cooled to -50 degrees C and then immersed in liquid nitrogen (LN) showed higher post-thaw motility than those cooled to -30 degrees C or -40 degrees C. When spermatozoa were cryopreserved to -50 degrees C at various cooling rates by changing the sample height above the LN surface, the post-thaw motilities of spermatozoa cooled at 10 cm (cooling rate: -21.3 degrees C/min) and 12.5 cm (-15.6 degrees C/min) from the LN surface were higher than those at 5, 7.5 or 15 cm. These results indicate that 10% MET plus 90% diluent comprising 80% seawater and 20% FBS is a suitable extender for cryopreservation of Japanese pearl oyster spermatozoa and that samples should be cooled to -50 degrees C at a cooling rate between -15 and -20 degrees C/min for efficient storage.


Subject(s)
Cryopreservation/methods , Pinctada/physiology , Sperm Motility , Spermatozoa/physiology , Temperature , Animals , Cryoprotective Agents/pharmacology , Male , Semen Preservation/methods , Spermatozoa/drug effects , Time Factors
17.
J Exp Zool A Comp Exp Biol ; 305(10): 823-9, 2006 Oct 01.
Article in English | MEDLINE | ID: mdl-16917813

ABSTRACT

The Itasenpara bitterling has an embryonic period up to 7 months, when the embryo experiences large seasonal temperature changes. We examined the temperature requisites for normal development during the embryonic stage. Fertilized eggs reared under any of the constant temperatures ranging from 5 degrees C to 30 degrees C did not achieve complete embryogenesis, and none reached the swim-up stage. The optimum temperature for normal embryonic development was found to be stage-dependent: 10-30 degrees C for fertilization, 15-25 degrees C for hatching, 5 degrees C for the requisite low temperature, 10-15 degrees C for eye pigmentation, and 20-30 degrees C for swim-up. These temperatures correlated well with the embryo's natural environmental conditions. Embryos raised at these temperatures sequentially grew normally, with 70% of the fertilized eggs achieving complete embryogenesis and, for the first time, developed to the swim-up stage. These results indicate that the low temperature, as required by the bitterling embryo, is an essential factor and correlates well with the embryo's natural ambient temperatures. Since the populations of Itasenpara bitterlings have been declining in Japan, this study is the first to provide additional information for successful artificial breeding of this endangered species.


Subject(s)
Cold Temperature , Cyprinidae/embryology , Embryo, Nonmammalian/embryology , Embryonic Development/physiology , Animals , Breeding , Cyprinidae/growth & development , Embryo, Nonmammalian/physiology , Female , Insemination, Artificial/methods , Life Cycle Stages/physiology , Male , Seasons
18.
Article in English | MEDLINE | ID: mdl-16820313

ABSTRACT

We previously isolated cDNAs encoding conger eel (Conger myriaster) thyroid hormone (TH) receptors (TRs). In the present study, we investigated the transactivation activities of conger eel TRs treated with THs (3,3',5-triiodo-l-thyronine [T3], l-thyroxine [T4], and 3,3',5'-triiodo-l-thyronine [rT3]), or ligands and activators of other nuclear receptors. Following transient transfection into the Japanese eel (Anguilla japonica) hepatocyte cell line Hepa-E1, the conger eel TRs (cTRs) showed TH-dependent activation of transcription from a TH-responsive promoter. However, no transactivation activity of any of the four cTRs was observed with ligands or activators of other nuclear receptors. Although T3 activation for cTRs is stronger than other THs (T3>T4>rT3), the transactivation sensitivity was different from the activity of cTRs with THs, respectively. Therefore, we conclude that cTRs can act in concert with THs in fish metamorphosis.


Subject(s)
Eels/metabolism , Receptors, Thyroid Hormone/metabolism , Thyroid Hormones/pharmacology , Transcriptional Activation , Animals , Cell Line , Hepatocytes/cytology , Hepatocytes/metabolism , Liver/metabolism , Receptors, Thyroid Hormone/agonists , Receptors, Thyroid Hormone/genetics , Thyroxine/pharmacology , Triiodothyronine, Reverse/pharmacology
19.
Article in English | MEDLINE | ID: mdl-16828323

ABSTRACT

In a previous study, we identified cDNAs encoding the growth hormone receptor (eGHR1) and eGHR1 homologue (eGHR2) in Japanese eel (Anguilla japonica). In the present study, changes in the developmental expression of growth hormone (GH), eGHR1 and eGHR2 were investigated in the Japanese eel eggs and preleptocephali by RT-PCR and immunohistochemical methods in an attempt to examine the involvement of these proteins in larval growth. The GH transcripts and the production of GH protein were not detected in the newly hatched larvae and preleptocephali at day 3 post-hatch, however, these were detected at day 6 post-hatch, and also detected at higher levels at day 10 post-hatch. In contrast, prolactin and somatolactin transcripts could not be detected in all preleptocephalus specimens (newly hatched larvae and preleptocephali at day 3, 6 and 10 post-hatch). eGHR1 and eGHR2 transcripts were detected in all preleptocephalus specimens. Therefore, it is plausible that the actions of GH during the preleptocephalus stage are mediated through the eGHRs. The present data suggest that GHR-mediated actions of GH begin at the same time as the initiation of GH production, and that GH plays important roles in larval growth and survival to the leptocephalus stage. eGHR1 mRNA, which is thought to be of maternal origin, was also detected in ovulated eggs. However, the role of eGHR1 mRNA in eggs is not clear.


Subject(s)
Anguilla/growth & development , Anguilla/metabolism , Growth Hormone/metabolism , Receptors, Somatotropin/metabolism , Animals , Female , Gene Expression Regulation , Immunohistochemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
20.
Zoolog Sci ; 23(5): 443-8, 2006 May.
Article in English | MEDLINE | ID: mdl-16766863

ABSTRACT

A cDNA encoding transthyretin was cloned from the Pacific bluefin tuna (Thunnus orientalis). This cDNA contains a complete open reading frame encoding 151 amino acid residues. The deduced amino acid sequence is 81% and 55% identical to the gilthead seabream and common carp forms, respectively, and 33-39% to mammalian, reptilian, and amphibian forms. A 1.0-kb transcript was found in the the liver and ovary; the liver is the main source of this protein. Analysis of triiodo-L-thyronine (T(3)) and L-thyroxine (T(4)) binding demonstrated that both T(3) and T(4) bind to bluefin transthyretin. The binding activity of T(3) for bluefin transthyretin is higher than that of T(4). These results indicate that bluefin transthyretin acts as a transporter of thyroid hormones (THs) in the plasma, and plays an important role in the function of THs in target cells.


Subject(s)
DNA, Complementary/analysis , Liver/metabolism , Prealbumin/genetics , Prealbumin/isolation & purification , Thyroid Hormones/metabolism , Tuna/metabolism , Amino Acid Sequence , Animals , Base Sequence , DNA, Complementary/chemistry , Female , Gene Expression , Male , Molecular Sequence Data , Open Reading Frames , Ovary/metabolism , Prealbumin/chemistry , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sequence Alignment , Sequence Homology, Nucleic Acid , Thyroxine/metabolism , Triiodothyronine/metabolism , Tuna/blood
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