Initiation of follicular maturation during mid-pregnancy by the administration of LH in the rat

Pregnant rats were injected twice daily for 1-3 days (Days 13-16 of pregnancy) with various doses of ovine LH. Follicular maturation was determined by the ability of the follicles to ovulate in response to 10 i.u. hCG as well as by endogenous production of oestradiol-17 beta and inhibin. In control animals, no ovulation was induced by hCG given on Day 16 of pregnancy. An injection of hCG on Day 16 of pregnancy, however, induced ovulation in LH-treated animals (6.25-50.0 micrograms LH per injection, s.c. at 12-h intervals from Days 13 to 16). Concentrations of oestradiol-17 beta and inhibin activity in ovarian venous plasma increased after the administration of LH, indicating that development of ovulatory follicles had been induced. Abolishing the decline in plasma LH values therefore induced maturation of a new set of follicles or prevented the atresia of large antral follicles usually seen at this time of pregnancy. Plasma and pituitary concentrations of FSH decreased in LH-treated animals compared with those in control animals. Concentrations of progesterone, testosterone and oestradiol-17 beta in the peripheral plasma were not significantly different between the two groups. These results suggest that the increase in inhibin secretion from the ovary containing maturing follicles after LH treatment may suppress the secretion of FSH from the pituitary gland. These findings indicate that (1) the development of ovulatory follicles can be induced by the administration of exogenous LH during mid-pregnancy in the rat and (2) basal concentrations of FSH are enough to initiate follicular maturation even in the presence of active corpora lutea of pregnancy, when appropriate amounts of plasma LH are present.     

The distribution of homologous enterococcal plasmid DNA sequences in human faecal isolates.

Hybridization was used to investigate the distribution of enterococcal plasmid sequences among 306 strains of Enterococcus and Streptococcus spp. isolated from faeces of humans of various ages. As DNA probes for the survey three plasmids, whose DNAs did not hybridize each other and designated as pMS13, pTW34 and pHK30, were selected from plasmids borne in Ent. faecalis. pTW34 DNA hybridized only with DNAs from enterococci, with high frequency in Ent. faecalis and low frequency in Ent. faecium. pMS13 DNA hybridized with DNAs of all Enterococcus spp. tested and with Strep. bovis, Strep. equinus and Strep. salivarius. Eighty-five percent of Ent. faecium isolates had sequences homologous to pMS13 but in the other species the values were less than 60%. Some enterococci had DNAs which hybridized with the pHK30 probe. The different distribution of the three DNA sequences indicates the possibility that plasmid DNAs encode advantageous phenotypes for the colonization of bacteria in the lumen of the bowel.     

Stability and reproducibility of proteomic profiles in epidemiological studies: comparing the Olink and SOMAscan platforms

Limited data exist on the performance of high-throughput proteomics profiling in epidemiological settings, including the impact of specimen collection and within-person variability over time. Thus, the Olink (972 proteins) and SOMAscan7Kv4.1 (7322 proteoforms of 6596 proteins) assays were utilized to measure protein concentrations in archived plasma samples from the Nurses’ Health Studies and Health Professionals Follow-Up Study. Spearman's correlation coefficients (r) and intraclass correlation coefficients (ICCs) were used to assess agreement between (1) 42 triplicate samples processed immediately, 24-h or 48-h after blood collection from 14 participants; and (2) 80 plasma samples from 40 participants collected 1-year apart. When comparing samples processed immediately, 24-h, and 48-h later, 55% of assays had an ICC/r ≥ 0.75 and 87% had an ICC/r ≥ 0.40 in Olink compared to 44% with an ICC/r ≥ 0.75 and 72% with an ICC/r ≥ 0.40 in SOMAscan7K. For both platforms, >90% of the assays were stable (ICC/r ≥ 0.40) in samples collected 1-year apart. Among 817 proteins measured with both platforms, Spearman's correlations were high (r > 0.75) for 14.7% and poor (r < 0.40) for 44.8% of proteins. High-throughput proteomics profiling demonstrated reproducibility in archived plasma samples and stability after delayed processing in epidemiological studies, yet correlations between proteins measured with the Olink and SOMAscan7K platforms were highly variable.     

Construction of a consensus linkage map for red clover (Trifolium pratense L.)

Background  

Red clover (Trifolium pratense L.) is a major forage legume that has a strong self-incompatibility system and exhibits high genetic diversity within populations. For several crop species, integrated consensus linkage maps that combine information from multiple mapping populations have been developed. For red clover, three genetic linkage maps have been published, but the information in these existing maps has not been integrated.     

A new male hypogonadism mutant rat (hgn/hgn): concentrations of testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in the serum and the responsiveness of accessory sex organs to exogenous T, FSH, human chorionic gonadotropin, and luteinizing hormone-releasing hormone

To determine the etiology of male hypogonadism in a newly found mutant rat (hgn/hgn, with a single autosomal recessive trait), concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured, and the responsiveness of the urogenital organs, hypothalamus, and pituitary gland to testosterone (1 mg/kg s.c. for 7 days), FSH (0.3 AU/kg s.c. for 7 days), human chorionic gonadotropin (hCG) (40 IU/kg s.c. for 7 days), and luteinizing hormone-releasing hormone (LHRH) (0.5 or 5.0 micrograms/kg s.c. for 7 days) were tested. Treatment with testosterone only increased the weights of all of the accessory sex organs, whereas treatment with FSH, hCG, or LHRH did not. Levels of serum FSH and LH were extremely higher and testosterone was lower in hgn/hgn males than in normal males. Serum FSH and LH decreased to levels found in intact animals after treatment with testosterone, suggesting that hypothalamic responsiveness to exogenous testosterone is present in the hgn/hgn males. Thus, the status of the hgn/hgn males was indicated to be due to primary Leydig cell dysfunction.     

Age-related changes in the secretory pattern of FSH and LH in response to LH-RH in prepubertal female rats

Developmental changes in the pituitary responsiveness and the secretory pattern of FSH and LH in response to a single injection of LH-RH (100 ng/rat, s.c.) as estimated by increases in plasma concentrations of FSH and LH 10, 30 and 60 min after the injection were studied in female rats at 5, 10, 15, 20, 25 and 30 days of age. The pituitary responsiveness to LH-RH for both FSH and LH release increased from 5 to 15 days of age, reached a maximum on 15 days of age and declined thereafter, whereas a marked increase in the amount of these hormones in the pituitary occurred between 15 and 20 days of age. An apparent change in the secretory pattern of both FSH and LH was observed from 20 days of age onward. In groups up to 15 days of age, plasma concentrations of FSH and LH remained elevated 60 min after the injection of LH-RH, though the plasma concentration of these hormones returned to preinjection concentrations in groups at 20 days of age or later. These results indicate that the age-related changes in the secretory pattern of LH and FSH in response to LH-RH as well as changes in the pituitary responsiveness were apparent during the prepubertal period.     

Active forms of chymotrypsin C isolated from autolyzed porcine pancreas glands

Four active forms of chymotrypsin C (C1, C2A, C2B, and C3) were isolated from the autolyzed porcine pancreas glands. Their molecular weights were estimated by SDS-polyacrylamide gel electrophoresis to be 29 100 for C1, 26 300 for C2A and C3, and 25 500 for C2B. The kinetic analyses of esterase activity of the enzymes toward Ac-LLeu-OEt and Ac-LPhe-OEt showed that chymotrypsin C1 hydrolyzed the two substrates more efficiently than did chymotrypsin C3. Chymotrypsin C1 consisted of chain A (H-Cys-...-Asn-OH, Mr 886) and chain BC (H-Val-...-Lys-OH, Mr 28 200). Chymotrypsin C3 consisted of the two components of C3L and C3S that could be dissociated in the presence of 2.3% SDS. C3L consisted of the chain A and the chain C (H-Ser-...-Lys-OH, Mr 13 600). C3S was the chain B (H-Val-...-Lys-OH, Mr 11 800). These kinetic and chemical analyses show that chymotrypsins C1 and C3 correspond to chymotrypsin A delta and A alpha, respectively.     

Isolation of human cDNA clones of myb-related genes, A-myb and B-myb.

cDNA clones of the myb-related genes A-myb and B-myb were obtained by screening human cDNA libraries. The predicted open reading frame of B-myb could encode a protein of 700 amino acid residues. Although the C-terminal end has not been cloned yet, an almost entire coding region of A-myb, which is 745 amino acid long, was determined. The A-myb and B-myb proteins are highly homologous with the myb protein in three regions. Domain I, which is 161 amino acid long, is well conserved in the myb gene family. The homology between human-myb and A-myb in domain I is 90% at the amino acid level. Domain II, which is about 85 amino acid long, is less well conserved. Although it is a short stretch, domain III is found in the C-terminal region. The mRNAs of A-myb and B-myb were 5.0 and 2.6 kb, respectively. The mRNA expression pattern of the myb gene family in various tumors is presented.     

Callus proliferation from leaf protoplasts using phenylurea type cytokinin, 4-PU,inBetula platyphylla VAR.Japonica

Summary Protoplasts were isolated from leaves ofBetula platyphylla var.japonica using a 0.6M mannitol solution containing 1% Cellulase Onozuka R-10 and 1% Driselase. The cell division and colony formation were largely enhanced using Murashige and Skoog (1962) liquid medium at half strength (1/2 MS), containing 0.6M mannitol, 0.09M sucrose, and factorial combinations of 0.1–30 μM N-(2-chloro-4-pyridyl)-N′-phenylurea (4-pu) and 0.1–10 μM 1-naphthaleneacetic acid (NAA) or 0.1–30 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The optimal protoplast density was 5–7 × 10⁴/ml. Continuous callus proliferation from protoplasts was achieved by transferring colonies to fresh 1/2 MS agar medium containing 1 μM NAA and 1 μM 4-pu with no mannitol. It appeared that supplementation of the medium with phenylurea type cytokinin, 4-pu gave the successful callus proliferation from the protoplasts ofB. platyphylla.