Production of mouse fibroblast growth factor 4 in E. coli and its application for isolation and maintenance of mouse trophoblast stem cells in vitro

Fibroblast growth factor 4 (FGF4) promotes isolation of trophoblast stem (TS) cells from mouse blastocysts and maintenance of TS cells in an undifferentiated state in vitro. To date, commercially available, bacterially expressed human FGF4 (RhFGF4) has been used generally for this purpose. In this study, HismFGF4, a 6x histidine-tagged mouse FGF4, was produced in E. coli and purified using heparin column chromatography. We demonstrated that HismFGF4 (25 ng/ml) more efficiently generates mouse TS cells from a single blastocyst than RhFGF4 (25 ng/ml) and that TS cells isolated and maintained with HismFGF4 retained their ability to differentiate into the trophoblast cell lineage in vitro. In addition, TS cells cultured with HismFGF4 (25 ng/ml) were maintained in an undifferentiated state better than with RhFGF4 (25 ng/ml). To the best of our knowledge, this is the first application of a mouse FGF4 derivative for isolation and maintenance of mouse TS cells.     

Ultrastructure of boar testis: spindle shape body of spermatid

The fine structure of the spindle shape body (SSB) of boar spermatid was studied using testes samples fixed by perfusion. This structure appeared on the middle piece which served as the upper border of the fibrous sheath of principal piece during the transition period between the late acrosome phase to the maturation phase of spermiogenesis. The formation of this thread-like spindle form coincided with the development of the postnuclear sheath with perinuclear ring just prior to the growth of the equatorial segment of the acrosome. Likewise, the ribs of the fibrous sheath on the principal piece were observed to have already formed but have not yet completed the mitochondrial sheath. The total size of the SSB and its consisting microtubule were measured. The functional meaning of this transitory construction may involve a threshold condition on the sperm middle piece.     

The posterior nasal nerve plays an important role on cardiopulmonary reflexes to nasal application of capsaicin, distilled water and l-menthol in anesthetized dogs

The sensory innervation of the cardiopulmonary reflexes to nasal application of capsaicin (CAPS), distilled water (DW) and l-menthol (LM) was studied in anesthetized dogs breathing through tracheostomy. A marked cardiopulmonary reflex was observed by CAPS and DW into the nasal cavity, while a prolongation of expiration was induced by LM. All these reflexes were significantly decreased by bilateral section of the posterior nasal nerve (PNN) and completely abolished by topical nasal anesthesia with lidocaine. Responses of the whole nerve activity of the PNN to these substances corresponded to the magnitude of the reflexes. These results indicate that PNN afferents play an important role on the reflex elicitation of the noxious, water and cold stimuli from the nasal cavity.     

Retort beef aroma that gives preferable properties to canned beef products and its aroma components

The objective of this study is to identify the properties and responsible compounds for the aromatic roast odor (retort beef aroma) that commonly occurs in canned beef products and could contribute to their palatability. The optimal temperature for generating retort beef aroma was 121°C. An untrained panel evaluated both uncured corned beef and canned yamato‐ni beef and found that they had an aroma that was significantly (P < 0.01) similar to the odor of 121°C‐heated beef than 100°C‐heated beef. The panel also noted that the aroma of 121°C‐heated beef tended to be (P < 0.1) preferable than that of 100°C‐heated beef. These results suggest that retort beef aroma is one constituent of palatability in canned beef. GC‐MS (gas chromatography‐mass spectrometry) analysis of the volatile fraction obtained from 100°C‐ and 121°C‐heated beef showed that the amounts of pyrazine, 2‐methylpyrazine and diacetyl were higher in the 121°C‐heated beef than in the 100°C‐heated beef. GC‐sniffing revealed that the odor quality of pyrazines was similar to that of retort beef aroma. Therefore, pyrazines were suggested to be a candidate responsible for the retort beef aroma. Analysis of commercial uncured corned beef and cured corned beef confirmed the presence of pyrazine, 2‐methylpyrazine and 2,6‐dimethylpyrazine.     

Dynamic changes in plasma concentrations of gonadotropins, inhibin, estradiol-17beta and progesterone in cows with ultrasound-guided follicular aspiration

To elucidate the effects of ultrasound-guided transvaginal follicular aspiration, plasma concentrations of FSH, LH, inhibin, estradiol-17beta and progesterone, and folliculogenesis were examined in Holstein cows. Four clinically healthy cows with regular estrous cycles were scanned by ultrasound per rectum once a week for 9 weeks before the commencement of follicular aspiration. All visible follicles were divided into 3 categories based on their sizes (2 < or = small < 5 mm; 5 < or = medium < 10 mm, large > or = 10 mm). The follicular aspiration was started at random during the estrous cycle and conducted under epidural anesthesia induced with 5 ml of 2% lidocaine once a week for 6 weeks. The average number of total visible follicles > or = 2 mm in diameter at 7 days after aspiration (21.7 +/- 7.4, n = 24) was similar to that before starting aspiration (26.7 +/- 10.5, n = 36). Plasma inhibin and estradiol-17beta declined and fell to a trough on 1.5 days and returned to pre-aspiration values by 5 days after aspiration. Plasma concentrations of FSH increased and reached peak levels between 1 and 1.5 days after aspirations. Plasma concentrations of LH also increased and reached peak levels between 0.5 and 1.5 days after aspirations. Both plasma FSH and LH had returned to pre-aspiration levels by 5 days after aspirations. Plasma concentrations of progesterone did not change with the follicular aspiration. These results demonstrate that follicular aspiration decreases plasma concentrations of inhibin and estradiol-17beta, which in turn leads to a rise in plasma concentrations of FSH and LH. It is suggested that marked increases in plasma concentrations of FSH and LH after the aspiration stimulate the development and maturation of a new cohort of follicles within one week in cows.     

Ultrastructure of abnormal boar spermatid: acrosomic fragmentation and vacuolization.

The fine structure of acrosomic abnormalities such as fragmentation and vacuolization of boar spermatids was studied in 4 different breeds (Duroc, Hampshire, Landrace and Yorkshire). These abnormalities initially appeared from the cap phase of spermiogenesis. The acrosome did not consist of serial sac covering the hemispherical nucleus, but only of a large acrosomic vesicle containing a dense granule and several pieces of cleaved proacrosomic vesicles attached to the anterior half of the round nucleus. The abnormality was frequently observed in the sister cells connected with the intercellular bridge. In the same seminiferous tubules, there was another abnormality on the acrosomic vacuolization of limited membrane system. Multiple vacuoles or vesicles were seen in the apical part of the nucleus in the cap phase, and also in the lower part of the equatorial segment of the acrosome phase.     

Antihemophilic factor release by perfused liver and spleen: relationship to hemophilia

As judged by perfusion of isolated organs an antihemophilic factor is produced in the liver and the spleen. Perfusates (from hemophiliacs) that are deficient in the human anti-hemophilic factor stimulate production of the factor during perfusion. Apparently there is an antihemophilic-factor-stimulating substance in the plasma of hemophiliacs. The data suggest that splenic homotransplantation might alleviate the symptoms of hemophilia.     

Effect of the lateral growth rate on wood properties in fast-growing hardwood species

We investigated the feasibility of using several fast-growing tropical or subtropical hardwood species for timber production by measuring key wood qualities in relationship to the high rates of lateral growth. The trees tested were sampled from even-aged plantations of Acacia mangium, A. auriculiformis, hybrid Acacia (A. mangium × A. auriculiformis), Eucalyptus grandis, E. globulus, and Paraserianthes falcataria (Solomon and Java origin) that had already reached commercial harvesting age. The released strain of the surface growth stress (RS), xylem density (XD), microfibril angle (MFA), and fiber length (FL) were measured at the outermost part of the xylem at breast height in each tree. Results were then compared to the lateral growth rate (radius/age) at breast height, which provides a relative indicator of the amount of tree growth per year. Our findings indicated that RS was constant, regardless of lateral growth rate in each species. Similar results were observed for XD, MFA, and FL, with a few exceptions, suggesting that high growth rates do not intrinsically affect the wood properties of fast-growing tropical or subtropical species that have reached harvesting age. However, special attention must be paid to patterns of xylem maturation when developing plantations of such species.     

Growth response to the stress of low osmotic potential,salinity and high pH in cultured shoot of Chinese poplars

In vitro cultured shoots of three Chinese poplar species (Populus tomentosa, P. alba cv. Pyramidalis andP. euphratica) and an improved poplar (FS-51), as a control, were exposed to the stress of low osmotic potential, salinity and high pH, and the shoot growth was measured.P. tomentosa andP. euphratica could grow even under the high osmotic stress (0.5m mannitol; −1.7 MPa).P. euphratica shoots which were previously cultured on the medium containing 0.7m mannitol (−2.4 MPa) recovered its growth after being transplanted to the medium without mannitol. The shoot growth ofP. euphratica was not so reduced even on the medium containing 100 mM NaCl. However, growth of the other poplars markedly reduced with 10 mM NaCl. Medium pH (pH 5.8–10) also did not affect the shoot growth ofP. euphratica. These poplars have different tolerance to the stresses in cultured shootin vitro. P. euphratica was extremely tolerant to the stresses which are possible to damage plants in dry land. A part of this study was presented at the 104th Annual Meeting of the Japanese Forestry Society. (1993).