Evidence for the role of INSL3 on sperm production in boars by passive immunisation.

Insulin-like factor 3 (INSL3), previously called relaxin-like factor, is essential for foetal testis descent and has been implicated in sperm production in adult males. This study investigated the role of INSL3 in sperm production by examining the effect of neutralising INSL3 by passive immunisation on testicular function and sperm output in boars. Six male Duroc boars were randomly assigned to passive immunisation and control groups (n = 3 each). The immunisation group was intravenously injected with an IgG fraction of anti-INSL3 antibody developed against the B domain of INSL3 at 2-week intervals from 21-40 weeks of age. The control group was treated with normal IgG in the same manner. Antibody administration reduced testis weight and caused a fourfold increase in the frequency of apoptotic germ cells, which was associated with upregulation of the pro-apoptotic caspase 3 and BAX, and downregulation of the anti-apoptotic XIAP and BCL2, and a substantial marked reduction in sperm concentration. Neutralising INSL3 delivered by passive immunisation reduced testis weight and sperm concentration by inducing germ cell apoptosis, suggesting that INSL3 acts as a germ cell survival/anti-apoptotic factor in the maintenance of sperm production.

Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats.

Thromboembolic and haemorrhagic complications are the primary causes of mortality and morbidity in patients with artificial hearts, which are known to be induced by the interactions between blood flow and artificial material surfaces. The authors have been developing a new mechanical artificial myocardial assist device by using a sophisticated shape memory alloy fibre in order to achieve the mechanical cardiac support from outside of the heart without a direct blood contacting surface. The original material employed as the actuator of artificial myocardial assist devices was 100um fibred-shaped, which was composed of covalent and metallic bonding structure and designed to generate 4-7 % shortening by Joule heating induced by the electric current input. In this study, we focused on the synchronization of the actuator with native cardiac function, and the phase delay parameter was examined in animal experiments using Saanen goats. Total weight of the device including the actuator was around 150g, and the electric power was supplied transcutaneously. The device could be successfully installed into thoracic cavity, which was able to be girdling the left ventricle. The contraction of the device could be controlled by the originally designed microcomputer. The mechanical contraction signal input had been transmitted with the phase delay of 50-200 msec after the R-wave of ECG, and hemodynamic changes were investigated. Cardiac output and systolic left ventricular pressure were elevated with 20% delay of cardiac cycle by 27% and 7%, respectively, although there was smaller difference under the condition of the delay of over 30%. Therefore, it was suggested that the synchronization measures should be examined in order to achieve sophisticated ventricular passive/active support on physiological demand.

Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre.

The authors have been developing an artificial myocardium, which is capable of supporting natural contractile function from the outside of the ventricle. The system was originally designed by using sophisticated covalent shape memory alloy fibres, and the surface did not implicate blood compatibility. The purpose of our study on the development of artificial myocardium was to achieve the assistance of myocardial functional reproduction by the integrative small mechanical elements without sensors, so that the effective circulatory support could be accomplished. In this study, the authors fabricated the prototype artificial myocardial assist unit composed of the sophisticated shape memory alloy fibre (Biometal), the diameter of which was 100 microns, and examined the mechanical response by using pulse width modulation (PWM) control method in each unit. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance and also the initial response of each unit were obtained. The component for the PWM control was designed in order to regulate the myocardial contractile function, which consisted of an originally-designed RISC microcomputer with the input of displacement, and its output signal was controlled by pulse wave modulation method. As a result, the optimal PWM parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control theory might be applied for more sophisticated ventricular passive or active restraint by the artificial myocardium on physiological demand.

Morphological approach for the functional improvement of an artificial myocardial assist device using shape memory alloy fibres.

The authors have been developing a mechano-electric artificial myocardial assist system (artificial myocardium) which is capable of supporting natural contractile functions from the outside of the ventricle without blood contacting surface. In this study, a nano-tech covalent type shape memory alloy fibre (Biometal, Toki Corp, Japan) was employed and the parallel-link structured myocardial assist device was developed. And basic characteristics of the system were examined in a mechanical circulatory system as well as in animal experiments using goats. The contractile functions were evaluated with the mock circulatory system that simulated systemic circulation with a silicone left ventricular model and an aortic afterload. Hemodynamic performance was also examined in goats. Prior to the measurement, the artificial myocardial assist device was installed into the goat's thoracic cavity and attached onto the ventricular wall. As a result, the system could be installed successfully without severe complications related to the heating, and the aortic flow rate was increased by 15% and the systolic left ventricular pressure was elevated by 7% under the cardiac output condition of 3L/min in a goat. And those values were elevated by the improvement of the design which was capable of the natural morphological myocardial tissue streamlines. Therefore it was indicated that the effective assistance might be achieved by the contraction by the newly-designed artificial myocardial assist system using Biometal. Moreover it was suggested that the assistance gain might be obtained by the optimised configuration design along with the natural anatomical myocardial stream line.

Development of rat tetraploid and chimeric embryos aggregated with diploid cells.

In the present study, we examined the preimplantation and postimplantation development of rat tetraploid embryos produced by electrofusion of 2-cell-stage embryos. Developmental rate of tetraploid embryos to morula or blastocyst stage was 93% (56/60) and similar to that found in diploid embryos (95%, 55/58). After embryo transfer, rat tetraploid embryos showed implantation and survived until day 8 of pregnancy, however the conceptuses were aberrant on day 9. In mouse, tetraploid embryos have the ability to support the development of blastomeres that cannot develop independently. As shown in the present study, a pair of diploid blastomeres from the rat 8-cell-stage embryo degenerated immediately after implantation. Therefore, we examined whether rat tetraploid embryos have the ability to support the development of 2/8 blastomeres. We produced chimeric rat embryos in which a pair of diploid blastomeres from an 8-cell-stage green fluorescent protein negative (GFP-) embryo was aggregated with three tetraploid blastomeres from 4-cell GFP-positive (GFP+) embryos. The developmental rate of rat 2n(GFP-) <--> 4n(GFP+) embryos to the morula or blastocyst stages was 93% (109/117) and was similar to that found for 2n(GFP-) <--> 2n(GFP+) embryos (100%, 51/51). After embryo transfer, 2n(GFP-) <--> 4n(GFP+) conceptuses were examined on day 14 of pregnancy, the developmental rate to fetus was quite low (4%, 4/109) and they were all aberrant and smaller than 2n(GFP-) <--> 2n(GFP+) conceptuses, whereas immunohistochemical analysis showed no staining for GFP in fetuses. Our results suggest that rat tetraploid embryos are able to prolong the development of diploid blastomeres that cannot develop independently, although postimplantation development was incomplete.

Development of an Artificial Myocardium using a Covalent Shape-memory Alloy Fiber and its Cardiovascular Diagnostic Response.

The authors have been developing a newly-designed totally-implantable artificial myocardium using a covalent shape-memory alloy fibre (Biometal®, Toki Corporation), which is attached onto the ventricular wall and is also capable of supporting the natural ventricular contraction. This mechanical system consists of a contraction assistive device, which is made of Ti-Ni alloy. And the phenomenon of the martensitic transformation of the alloy was employed to achieve the physiologic motion of the device. The diameter of the alloy wire could be selected from 45 to 250μm. In this study, the basic characteristics of the fiber of 150μm was examined to design the sophisticated mechano-electric myocardium. The stress generated by the fiber was 400gf under the pulsatile driving condition (0.4W, 1Hz). Therefore it was indicated that the effective assistance might be achieved by using the Biometal shape-memory alloy fiber.

Seminal immunoreactive relaxin in domestic animals and its relationship to sperm motility as a possible index for predicting the fertilizing ability of sires.

Although immunoassayable relaxin has been detected in human and boar seminal plasma, there is no evidence suggesting the existence of immunoreactive relaxin in the seminal plasma of other domestic animals. The first objective of this study was to determine whether immunoreactive relaxin was present in the seminal plasma of bulls, rams and he-goats. In addition, the correlation of immunoreactive relaxin with sperm motility as an index for predicting the fertilizing ability of bull sires was investigated. Semen with normal sperm motility was collected from bulls, rams and he-goats, and the relaxin immunoreactivity of the semen samples was measured using a time-resolved fluoroimmunoassay (TR-FIA) for porcine relaxin that we developed. The presence of relaxin immunoreactivity was demonstrated in seminal plasma from bulls, rams and he-goats. The level of immunoreactive relaxin in seminal plasma was the highest in bulls followed by humans, rams, boars and he-goats in that order, when relaxin levels in boar and human semen having normal sperm motility were also assayed under the same conditions. When the correlation between the seminal plasma level of immunoreactive relaxin and sperm motility was examined in bull semen samples as an index for predicting fertilizing ability, it was found that the relaxin level was significantly correlated with the percentage of spermatozoa showing the most intensive motility (r = 0.64, p < 0.05). These results indicate that immunoreactive relaxin is widely found in the seminal plasma of domestic animals and that measuring the relaxin concentration of seminal plasma may be useful to identify subfertile sires or predict the fertility potential of individual sires.

Vitrification of large quantities of immature bovine oocytes using nylon mesh.

Vitrification of oocytes and embryos has recently been improved using new physical supports such as electron microscope (EM) grids, open-pulled straws, and cryoloops. However, the number of samples per container was restricted in each of these methods. In the present study, to develop a novel simple technique for vitrification of large quantities of oocytes or embryos, we examined vitrification of large quantities of immature bovine oocytes using nylon mesh as a novel container. As many as 65 oocyte-cumulus cell complexes could be placed on nylon mesh for vitrification compared with 15 per EM grid. Recovery rates were higher when using nylon mesh than EM grids, while fertilization and development rates were not different. These results indicated that vitrification using nylon mesh is useful and offers a new way to cryopreserve large numbers of oocytes.

Immunoreactive relaxin in seminal plasma of fertile boars and its correlation with sperm motility characteristics determined by computer-assisted digital image analysis.

Ejaculates from 10 mature fertile large white Yorkshire boars were used to examine the correlation between immunoreactive relaxin levels in seminal plasma and sperm motility characteristics. Seminal plasma levels of immunoreactive relaxin were measured by a time-resolved fluoroimmunoassay (TR-FIA). Motility characteristics were assessed using a CellSoft computer-assisted digital image analysis system. The mean +/- SD level of immunoreactive relaxin in seminal plasma was 2.61 +/- 0.62 ng/mL. When the correlation between seminal plasma levels of immunoreactive relaxin and parameters of sperm movement was examined, it was found that relaxin levels were significantly correlated with the percentage of motile spermatozoa (r=0.687, p < 0.05), curvilinear velocity (r=0.745, p < 0.05), straight line velocity (r=0.651, p < 0.05), mean amplitude of lateral head displacement (mean ALH) (r=0.844, p < 0.01) and the maximum amplitude of lateral head displacement (max ALH) (r=0.830, p < 0.01), but not with linearity, beat-cross frequency, or percentage of circular cells. Among these parameters, seminal plasma levels of immunoreactive relaxin showed the strongest correlation with the ALH parameter related to fertilizing ability. These results indicate that immunoreactive relaxin in boar semen may be necessary not only for normal sperm motility but also for normal fertility, suggesting that determination of the profile of immunoreactive relaxin in ejaculates may have value as a potential marker for predicting sperm fertilizing ability of boars.

Use of porous hydroxyapatite graft containing recombinant human bone morphogenetic protein-2 for cervical fusion in a caprine model.

OBJECT: The efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) for enhancing anterior cervical spine interbody fusion when added to a porous hydroxyapatite (HA) graft was investigated. METHODS: Fourteen mature goats underwent three-level anterior discectomies after induction of endotracheal anesthesia. Porous HA grafts that contained 0, 5, and 50 microg of rhBMP-2 were placed concurrently with anterior cervical spine plates to achieve interbody fusion. The fusion rate, radiological findings, biomechanical stiffness, and histological appearance were evaluated in 42 spinal units immediately and again at 4 and 12 weeks after graft and plate placement. At 12 weeks postsurgery, manual testing showed a 100% fusion rate in the spines with HA grafts containing high-dose rhBMP-2; however, only a 50% fusion rate was shown in spines with grafts that contained no or low-dose rhBMP-2. On radiographic and histological studies the process of solid fusion was seen to be more advanced in relation to the use of larger amounts of rhBMP-2. Biomechanical testing demonstrated significantly higher stiffness values for grafts that contained high-dose rhBMP-2 than those without rhBMP-2 in flexion at 4 weeks, as well as in flexion, extension, and lateral bending tests at 12 weeks. Histological analysis demonstrated that rhBMP-2 increased the amount of bone apposition on the surface of the implants and promoted bone formation in the porous structure without increasing the penetration distance. CONCLUSIONS: Through osteogenesis at the fusion site, the addition of rhBMP-2 to a porous HA ceramic graft enhances the rate of anterior cervical fusion.

Effects of hormones and osmolarity in the culture medium on germinal vesicle breakdown of porcine oocytes.

The present study was conducted to examine effects of hormones and osmolarity on germinal vesicle breakdown (GVBD) and histone H1 kinase (H1K) activity in porcine oocytes cultured in vitro. The basic medium used for culture of oocytes was modified Tyrode's solution in which the osmolarity was adjusted to 134 to 495 mOsm by changing the concentration of sodium chloride (NaCl). When the hormones were present, osmolarity of medium that allows GVBD of oocytes was less than 400 mOsm. However, the range of osmolarity of medium that allows meiotic maturation of oocytes was 210 to 362 mOsm. On the other hand, without hormonal supplement, the incidence of GVBD in oocytes decreased as the osmolarity of the medium increased in the rage of 210 to 362 mOsm. By increasing the osmolarity of the medium from 210 to 362 mOsm by addition with sorbitol instead of NaCl, the incidence decreased from 89.1% to 13.3%. In oocytes cultured in medium of 210 mOsm without hormones, the percentage of oocytes that underwent GVBD and had increased H1K activity 20 h after culture was significantly higher (P < 0.05) than those of oocytes cultured in the same medium supplemented with hormones or medium of 362 mOsm. These results indicate that in vitro induction of GVBD in porcine oocytes is strongly affected by osmolarity of the medium in the absence of hormones. The results also suggest that, under low osmolarity (210 mOsm), GVBD is accelerated with rapid increase of H1K activity.

Fluorescence in situ hybridization with Y chromosome-specific probe in decondensed bovine spermatozoa.

This study was carried out to demonstrate bovine Y chromosome-bearing spermatozoa by rapid fluorescence in situ hybridization (FISH), using a digoxigenin (Dig)-labeled DNA probe specific to bovine Y chromosome. Before the FISH procedure, sperm heads were treated for decondensation with dithiothreitol (DTT) and glutathione (GSH) with or without heparin supplementation. Concentrations of either above 2 mM DTT or above 100 mM GSH induced swelling of the sperm head, which resulted in sufficient detection of the Y chromosome signal in sperm nuclei by rapid FISH (49.8 to 53.4%). When FISH was used with 2 mM DTT or 100 mM GSH on specimens from 7 sires, the rate of detection of the Y chromosome signal varied among sires (5.4 to 49.6%), especially that of the GSH treatment. Supplementation of GSH with heparin (100 U/mL), however, could induce reliable, repeatable detection of the Y chromosome signal in sperm nuclei of all the 7 sires (48.4 to 50.3%). These results show that in bovine spermatozoa decondensed with GSH and heparin, rapid FISH can detect Y chromosome-bearing spermatozoa.

Rapid detection of male-specific DNA sequence in bovine embryos using fluorescence in situ hybridization.

An accurate, reliable, and quick (less than an hour) method for determining the sex of bovine embryos was developed using a fluorescence in situ hybridization (FISH), with a probe designed from a bovine Y chromosome specific DNA (BC1.2). First, to improve a protocol of FISH and evaluate an accuracy of the method, lymphocyte nuclei prepared from three bulls, two cows, and one freemartin were tested. We found that 5 min was enough for hybridization. The washing solution adequate for posthybridization was 0.5x SSC at 72 degrees C for 5 min. The whole procedure for FISH can be accomplished in less than an hour. A male-specific signal was detected, on average, as 97, 0.5, and 83%, respectively, of lymphocytes in males, females, and a freemartin. Using the rapid FISH protocol developed, 28 embryos were divided. According to the presence of the digoxigenin signal, 16 embryos (57.1%) were predicted as male, and 12 embryos (42.9%), predicted as female.

Permanent Dipole Moments of Methane-Type Molecules: Calculation of the DeltaJ = 0 Matrix Elements in the l = 1 Vibrational State

We examined permanent dipole moments (PDMs) of methane-type molecules induced by molecular internal motions which are expanded in terms of the vibrational coordinate operator q , total angular momentum operator J , and vibrational angular momentum operator l . The qq -, JJ -, Jl -, and ll -type quadratic terms of these operators contribute to the production of PDMs. The DeltaJ = 0 matrix elements of the four PDMs are calculated for the first excited state of the triply degenerate vibrational mode; a portion are numerically given in a table for the J

Precise frequency-difference measurement between the 1.66-mum transitions of methane.

We determined 66 frequency differences (FD's) between rovibrational lines of methane at the 1.66-mum region. Following the technique developed by Nakagawa et al.[Opt.Lett.20, 410 (1995)], we measured the FD's as the optical beat frequency between two external-cavity diode lasers locked at 1-MHz-wide saturated absorption dips of the methane lines. Even though the methane lines often overlap in Doppler-limited resolution, the spectrometer that we use resolves them and determines their FD's with better than 40-kHz precision. This fact demonstrates that the methane lines are promising candidates for frequency reference and that this technique has great potential for high-resolution molecular spectroscopy.

Effect of culture conditions on artificial activation of porcine oocytes matured in vitro.

The effects of culture media used and culture period for in vitro maturation of porcine oocytes on their subsequent response to chemical and electrical activation, were investigated. Activated oocytes were identified by the presence of a pronucleus(ei) or cleavage. Porcine oocytes were cultured for 24, 30, 36, 42 and 48 h in TCM199 with Earle's salts (199) supplemented with 10% fetal calf serum (199-FCS) before electrical stimulation. Although few oocytes were activated after 24 h and 30 h of culture (5.4% and 6.1% respectively), the percentage of activated oocytes increased significantly to 93.2% after 42 h in culture (P < 0.05); however, when the culture period was extended to 48 h, there was a significant decrease to 56.7% (P < 0.05). Oocytes were also cultured in four types of media: (1) 199-FCS; (2) 199 supplemented with 5 mg mL-1 bovine serum albumin (199-BSA); (3) Kreb's-Ringer bicarbonate solution supplemented with 10% FCS (KRB-FCS); and (4) KRB supplemented with BSA (KRB-BSA). After 42 h of culture in each medium, the oocytes were electrically activated. Although rates of maturation of oocytes cultured in the four media were similar (74.0-80.8%), all oocytes except those cultured in 199-FCS failed to be activated. In addition, oocytes were cultured for 36, 42 and 48 h in 199-FCS and then stimulated by treatment with ethanol. Significantly fewer oocytes were activated in the chemically-treated group than in the electrically-treated group. These results indicate that culture conditions used for the culture of porcine oocytes in vitro are important with respect to their subsequent response to artificial activation.

Optical frequency measurement of the H(12)C(14)N Lamb-dip-stabilized 1.5-microm diode laser.

We have measured the frequency of the P(27) line of H(12)C(14)N at 1556 nm, using the 778-nm two-photon transition of Rb as a frequency reference. The measured frequency was 192, 622, 446.9 +/- 0.1 MHz. We believe that this experiment is the first absolute frequency measurement of a laser stabilized to a saturation dip at 1.5 microm and also the most accurate measurement of a 1.5-microm optical frequency.

Mode-hop suppression of Littrow grating-tuned lasers: erratum.

A recent paper [Appl. Opt. 32, 269-274 (1993)) contained an analysis of the conditions required to suppress mode hops when one is tuning a Littrow grating-loaded laser cavity. Although the model was correct, an algebraic mistake led to a wrong conclusion. The corrected results are given and tend to recommend a previously investigated configuration.