Postpartum reproductive performance in the multiparous mare fed to obesity

Twenty multiparous Quarter Horse mares were assigned to one of two treatment groups at 40 to 75 d of pregnancy. Group 1 was the control group and the mares were fed to maintain a moderate degree of body fat (condition score 5.5 to 7). Group 2 was the obese group and the mares were fed to achieve (prepartum) and then maintain (post partum) an extremely high degree of body fat (condition score 9). Estrous intensity was evaluated using subjective teasing scores ranging from 0 (rejection) to 4 (maximum receptivity). Mares were artificially inseminated beginning with the second postpartum ovulatory cycle; the study was terminated after 63 d of pregnancy. Duration of estrus, maximum teasing score and the number of mares exhibiting overt estrus (teasing score > 2) did not differ between treatment groups during the first and second postpartum ovulatory cycles. The intervals from foaling to first cycle ovulation, foaling to second cycle ovulation, and first to second cycle ovulation were also similar between treatment groups. All mares in both treatment groups conceived and maintained pregnancy. The first cycle conception rate and the number of cycles per conception did not differ between treatment groups. A high degree of body fat produced by overfeeding during gestation did not adversely affect postpartum reproductive performance in the multiparous mare.     

Toxicity effects of latex gloves on boar spermatozoa

It is known that several materials used in semen collection have been found to be detrimental to spermatozoal motility. In this study, examinations for toxic effects of latex and vinyl gloves, used with and without talcum powder on boar spermatozoa, were performed. Ten boars of known fertility with >/=80% sperm motility were divided into two groups (n = 5 boars each) for in vitro and in vivo studies. In the in vitro study, semen was collected from each of the five boars and was divided into five separate aliquots (5 ml each). One aliquot from each of the boars remained as the control, while the remaining aliquots were divided into individual treatments exposing the semen to a l cm(2) piece of latex or vinyl glove with or without talcum powder. In the in vivo experiment, semen from each of the five boars was collected using a gloved hand. During collection, the first half of the sperm-rich fraction was collected into a filtered sterile container, while the second half of the fraction was allowed to run through the palm of either a latex or vinyl powdered glove prior to collection in the container. In both experiments, semen sample motility was assessed by two independent observers at 1 minute after exposure. Results of both experiments consistently showed a significant (P<0.05) effect of latex gloves (with or without talcum powder) on boar semen when compared with the control semen. Motility was at or near 0% at 1 min after exposure to latex. No significant difference (P>0.05) in motility was observed between the control semen and the semen exposed to talcum powdered vinyl gloves. These results show that latex gloves are detrimental to boar spermatozoa. Therefore, it is suggested that when collecting boar semen vinyl gloves should be used.     

Farrowing induction with cloprostenol-xylazine combination

Eighty crossbred, multiparous sows, weighing between 190 and 320 kg, were randomly assigned to the following four treatment groups of 20 sows each: 1) saline-saline, 2) cloprostenol-saline, 3) saline-xylazine and 4) cloprostenol-xylazine. The mean gestation length of each multiparous sow was calculated. Cloprostenol (250 ug/sow, i.m.) or saline was given 3 d prior to the calculated due date at 11:30 a.m. Xylazine (2 mg/kg, i.m.) or saline was given 20 h after either the cloprostenol or previous saline treatment. Cloprostenol-xylazine treated sows had the shortest mean farrowing interval (1.5 +/- 0.3 h) when compared with the rest of the treatment groups (saline-saline:66.0 +/- 8.1, cloprostenol-saline:10.5 +/- 1.9, saline-xylazine:60.6 +/- 5.6 h). Farrowing time, percentage of stillbirths, average birth weight, d-5 and d-21 postbirth weights, number of pigs born, number of pigs born alive, and number of pigs surviving at 5 and 21 d afterbirth were not significantly different among the four groups. This study demonstrated that cloprostenol-xylazine treatment decreases the time to onset of farrowing with less variation than cloprostenol or xylazine alone. Therefore, the use of a cloprostenol-xylazine combination is suggested as an alternative method for inducing farrowing.     

Lipid metabolism during the initiation of lactation in the rat. The effects of starvation and tumour growth.

1. The effects of starvation post partum (24 h) and tumour growth pre partum on the initiation of lactation in the rat were studied. 2. Tumour growth decreased food intake at 24 h, but not at 2 days post partum. 3. Pup growth rate increased with hyperphagia; starvation and tumour burden decreased pup growth, and starvation decreased maternal body weight. 4. Starvation decreased gastrointestinal-tract mass; tumour growth decreased gastrointestinal-tract and mammary-gland mass. 5. Mammary-gland DNA-synthesis rate was high immediately post partum, but decreased by day 3 of lactation; starvation and tumour burden decreased this rate, and also decreased gastrointestinal-tract DNA-synthesis rate. 6. Arteriovenous differences for glucose and lactate across the mammary gland did not change with time, nor were they affected by the tumour. Starvation decreased arterial glucose and lactate, and the gland extracted less glucose but produced lactate. 7. Mammary-gland lipogenesis was sensitive to starvation and to tumour growth. 8. In contrast with the gradual development of mammary-gland lipogenic enzyme activities, lipoprotein lipase activity was high in the gland by 2 days post partum; starvation or tumour burden decreased the activity. 9. The mammary gland is sensitive post partum to decreased food intake, and to tumour presence. The effects of the latter are apparently independent of hypophagia.     

Telomeric associations in a lymphoblastoid cell line from a patient with B-cell follicular lymphoma

We have established a new Epstein-Barr virus transformed cell line from a patient with B-cell follicular lymphoma. Telomeric fusions were observed in several subclones, with the nonrandom involvement of chromosomes 1, 5, 12, and 17. Centromeric staining with immunofluorescent anti-kinetochore antibodies was positive in both centromeres of the fused chromosomes, suggesting they were both active. Unlike previously reported cases, we were unable to demonstrate telomeric fusions directly in cells from the patient's blood. However, the finding of identical immunoglobulin gene rearrangements in DNA from the patient's blood and cell line suggested that they originated from the same malignant B-cell clone.     

The ras oncogene and tumour metastasis: observations on murine cells transfected with activated human c-Ha-ras

Transfection of cells with cloned genes or total genomic DNA offers a means for studying aspects of neoplastic behaviour. We have used this method to examine whether incorporation of the cloned 6.6-kilobase (kb) fragment of DNA containing the mutant c-Ha-ras human oncogene can confer metastatic capability on murine NIH 3T3 cells. Cells co-transfected with the mutated ras gene and the neomycin resistance marker pSV2neo were selected by culture in neomycin. On subcutaneous inoculation into MF 1 nude mice, these cells proved to be tumourigenic with short latent periods (approximately 14 days)--nude mice were used to circumvent immunological rejection of the mouse cells expressing the product of the human oncogene. Transfectants were capable of lung colonisation after intravenous injection, but there was no evidence of spontaneous metastasis at autopsy, or on histological examination of the lungs and other organs, 90 days after inoculation. Incorporation of the transfected oncogene was confirmed by Southern blotting and its expression by dot-blot hybridisation and immunoprecipitation. The results in this experimental system indicate that transfection of a mutated human ras oncogene into non-neoplastic 3T3 cells can confer part of the metastatic phenotype, namely lung colonisation, but is not by itself sufficient to induce spontaneous metastatic behaviour.     

Identification of a novel metabolite in phenanthrene metabolism by the fungus Cunninghamella elegans

The metabolism of phenanthrene by the fungus Cunninghamella elegans was investigated. Kinetic experiments using [9-14C]phenanthrene showed that after 72 h, 53% of the total radioactivity was associated with a glucoside conjugate of 1-hydroxyphenanthrene (phenanthrene 1-O-beta-glucose). This metabolite was isolated by reversed-phase high-performance liquid chromatography and characterized by the application of UV absorption, 1H nuclear magnetic resonance, and mass spectral techniques. The results show that aromatic ring oxidation followed by glucosylation is a predominant pathway in the metabolism of the polycyclic aromatic hydrocarbon phenanthrene by C. elegans.     

The pharmacology of L-670,596, a potent and selective thromboxane/prostaglandin endoperoxide receptor antagonist

L-670,596 ((-)6,8-difluoro-9-rho-methylsulfonyl benzyl-1,2,3,4- tetrahydrocarbazol-1-yl-acetic acid) has been shown to be a potent receptor antagonist as evidenced by the inhibition of the binding of 125I-labeled PTA-OH to human platelets (IC50, 5.5 x 10(-9) M), inhibition of U-44069 induced aggregation of human platelet rich plasma (IC50, 1.1 x 10(-7) M), and competitive inhibition of contractions of the guinea pig tracheal chain induced by U-44069 (pA2,9.0). The compound was also active in vivo as shown by inhibition of arachidonic acid and U-44069 induced bronchoconstriction in the guinea pig (ED50 values, 0.04 and 0.03 mg/kg i.v., respectively), U44069 induced renal vasoconstriction in the pig (ED50, 0.02 mg/kg i.v.), and inhibition of ex vivo aggregation of rhesus monkey platelets to U-44069 (active 1-5 mg/kg p.o.). The selectivity of the compound was indicated by the failure to inhibit, first, ADP-induced human or primate platelet aggregation and, second, bronchoconstriction in the guinea pig in vivo and contraction of the guinea pig tracheal chain in vitro to a variety of agonists. It is concluded that L-670,596 is a potent, selective, orally active thromboxane A2/prostaglandin endoperoxide receptor antagonist.     

Natural killer cells can enhance the proliferative responses of B lymphocytes

In addition to lytic activity against malignant and virally transformed target cells, recent evidence has suggested that natural killer (NK) cells can modulate immune activities such as the suppression of B cell responses through noncytotoxic means. Using human B cells and highly purified autologous NK cells, we have demonstrated that NK cells can substantially augment the proliferative responses of B cells stimulated with the surface immunoglobulin crosslinking agents anti-IgM or Staphylococcus aureus Cowan strain I (SAC). This "enhancer" activity of NK cells was quite potent and was observed at an NK:B cell ratio as low as 0.05. Peak blastogenic responses of B cells cocultured with NK cells in the presence of B cell activators were observed at 2-3 days, similar to the responses of B cells in the absence of NK cells. Using the inhibitor of DNA synthesis mitomycin C, we determined that B cells and not NK cells were proliferating in cocultures of these lymphocytes stimulated with SAC. Activated B cells neither prevented the lysis of the isotope-labeled NK-sensitive target cell line K562 nor formed conjugates with NK cells, suggesting that cell contact was not a prerequisite for the effect. These studies have further expanded the functional repertoire of NK cells to include enhancer as well as suppressor and lytic activities.     

Preparative isoelectric focusing in ampholine electrofocusing columns versus immobiline polyacrylamide gel for the purification of biologically active leukoregulin

Preparative vertical and rotating horizontal (Rotofor) ampholine column and immobiline flat bed polyacrylamide gel isoelectric focusing were evaluated for the isolation of the biologically active acidic form of leukoregulin, a 50,000-Da glycoprotein lymphokine with tumor growth inhibitory activity. Leukoregulin secreted by normal human lymphocytes was concentrated by 10,000 nominal molecular weight size exclusion ultrafiltration and by DEAE anion exchange chromatography using step elution with 0.02 M Tris-HCl: 0.1 M NaCl, pH 7.4. Preparative isoelectric focusing was carried out in a 110-ml vertical column containing 1% ampholines in a pH 4-6 gradient at 15 W constant power for 16-18 h, in a Rotofor 55-ml horizontal column containing 2% ampholines in a pH 4-6 gradient at 12 W constant power for 4-6 h, or in an immobiline pH 4.5-6.5 gradient within a 5% polyacrylamide 120 X 110 X 5-mm flat bed gel at 3 W constant power for 16-18 h. Recovery of biologically active leukoregulin from the vertical and horizontal ampholine columns was similar. The pH 4.9-5.2 fractions from the Rotofor ampholine column contained 4-7% and the fractions from the immobiline gel contained 4% of the leukoregulin activity applied to the electrofocusing column or gel, respectively. Analytical immobiline isoelectric focusing of the leukoregulin in the pH 4.9-5.2 fractions from the Rotofor column demonstrated that a single silver staining band with a pI of 5.1 can be obtained by this rapid method of preparative isoelectric focusing.