bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Progesterone Prior to GnRH‐PGF2α Treatment on Induction of Oestrus and Pregnancy in Anoestrous Awassi Ewes
Authors: Husein MQ , Kridli RT 
Published: May 2003

ContentsAn experiment was conducted to examine the effect of progesterone prior to a GnRH‐PGF2α treatment on oestrus and pregnancy in seasonally anoestrous Awassi ewes. Twenty‐four ewes were randomly assigned to three groups to be pre‐treated with 60 mg medroxyprogesterone acetate sponges (group A), 600 mg progesterone sponges (group B) or blank sponges (group C) for 4 days. All ewes were injected with 100 μg of GnRH 24 h after sponge removal followed, 5 days later, by 20 mg PGF2α injection. Ewes were exposed to three fertile rams at the time of PGF2α injection (day 0, 0 h) and were checked for breeding marks at 6‐h intervals for 5 days. Blood samples were collected from all ewes 1 day (day −10) prior to sponge insertion, at the time of sponge removal (day −6), 1 day following sponge removal (day −5, at the time of GnRH injection) and at the time of PGF2α injection (day 0) for analysis of progesterone. Progesterone concentrations on days −10 and −5 were basal and averaged 0.2 ± 0.04 and 0.2 ± 0.2 ng/ml, respectively. Progesterone concentrations on day −6 were elevated only in group B ewes and were higher (p < 0.0001) than those of groups A and C. Progesterone concentrations on day 0 were higher (p = 0.002) in groups A and B than group C. Oestrous responses occurred only in ewes of groups A and B (p > 0.05). Induced oestrus conception rate was greater (p < 0.01) in group A than groups B and C. Ewes returned to oestrus 17–20 days following day 0 were two of eight, six of eight and three of eight of groups A, B and C, respectively, all of which eventually lambed. The overall lambing rate was 82% in progesterone‐primed ewes compared with only 38% non‐progesterone‐primed ewes (p < 0.05). Progesterone priming apparently sensitizes GnRH‐PGF2α‐treated seasonally anoestrous ewes and increases their response in oestrus and pregnancy rates.
24‐Hour Secretion Patterns of Plasma Oestradiol 17β in Pony Mares in Late Gestation
Authors: O'Donnell LJ , Sheerin BR , Hendry JM , Thatcher MJ , Thatcher WW , LeBlanc MM 
Published: May 2003

ContentsThe mare exhibits nocturnal uterine contractions in the last 6 days of gestation. It is hypothesized that estradiol 17β (O17β) may be associated with the nightly increase in uterine contractions. The 24‐h secretion pattern of plasma O17β was measured in 3 pony mares in late gestation to identify changes in release as the mare neared parturition. Blood was collected weekly at 08:00 hours beginning on day 240 and every third day from day 330 until delivery. Serial blood samples were collected from each mare every 30‐min for 24‐h beginning on gestation day 310 and every sixth day thereafter until parturition. Concentrations of O17β were elevated at night with lowest concentrations occurring directly before sunset (p < 0.01). The natural log of the variance was increased at sunset (p < 0.01) and was decreased during the 6‐h period immediately after sunrise. This pattern was especially evident in the 6 days that preceded parturition. The contrast between nocturnal and daytime concentrations of O17β in the last 6 days of gestation may contribute to night‐time delivery in the mare.
Expression of Osteopontin (OPN) mRNA in Bovine Ovarian Follicles and Corpora Lutea
Authors: Brunswig‐Spickenheier B , Mukhopadhyay AK 
Published: May 2003

ContentsThe matricellular protein osteopontin (OPN) plays a role in various physiological processes, including angiogenesis and tissue remodelling. As these processes are essential for the maintenance of ovarian physiology, the aim of the study was to investigate the expression of OPN (mRNA) in ovarian cells and to evaluate whether it can be regulated by gonadotrophins. Using conventional RT‐PCR and real‐time PCR, we have detected and quantified OPN mRNA as well as glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) mRNA expression in bovine granulosa, theca and luteal cells. In all cells examined, both genes were found in equal amounts and no striking variations in the expression could be observed between granulosa, theca and luteal cells. Furthermore, no effect on either OPN or GAPDH mRNA expression was evident after culturing ovarian cells in the presence of gonadotrophic hormones, although the cells were still highly responsive in terms of cAMP formation. Although neither variations between different cell types nor a regulation of OPN mRNA expression by gonadotrophic hormones could be detected, the high and unambiguous mRNA expression in steroidogenic cells suggests that OPN should be added to the growing list of intraovarian factors which may be involved in ovarian physiology.
Effects of Short‐Term High Carbohydrate or Fat Intakes on Leptin, Growth Hormone and Luteinizing Hormone Secretions in Prepubertal Fat‐Tailed Tuj Lambs
Authors: Yildiz S , Blache D , Celebi F , Kaya I , Saatci M , Cenesiz M , Guven B 
Published: May 2003

ContentsThe aim of the current study was to evaluate the effects of high carbohydrate or fat diets, fed for 15 days at the end of breeding season, on leptin, GH and LH secretions in prepubertal fat‐tailed Tuj lambs. For that purpose, 9‐month‐old ram‐lambs were divided into three groups as control group (fed with basal ration, n = 4), high carbohydrate (HC) group, basal ration plus barley, n = 4), or high fat (HF) group (basal ration plus by‐pass fat, n = 4). For the measurement of leptin and GH, blood plasma samples were collected on days 1, 4, 9 and 14 of the experiment. For the measurement of LH pulse frequency, serial blood samples were collected every 15 min for 6 h on day 14. Lambs were weighed and body condition scored (BCS) on days 1 and 15. Body weight and BCS increased towards the end of the study (p < 0.05). The BCS was higher in high energy groups at the end of the experiment (p < 0.05). Diet affected plasma leptin concentrations (p = 0.002) but time did not. The GH concentrations were not affected by diet or time. The LH pulse frequency appeared to be higher in HC and HF groups but there were no statistical difference between the groups. There was a significant positive relationship between overall BCS and corresponding leptin concentrations (R2 = 0.263; p = 0.010) and between LH pulse frequency and leptin concentrations (R2 = 0.594; p = 0.003). In conclusion, the present study suggests that rather than type of energy, amount of energy intake and body energy reserves are much important regulators of plasma leptin concentrations and LH pulse frequency in fat‐tailed Tuj lambs.
The Effects of the Periodical Use of In‐feed Chlortetracycline on the Reproductive Performance of Gilts and Sows of a Commercial Pig Farm with a History of Clinical and Subclinical Viral and Bacterial Infections
Authors: Alexopoulos C , Fthenakis GC , Burriel A , Bourtzi‐Hatzopoulou E , Kritas SK , Sbiraki A , Kyriakis SC 
Published: May 2003

ContentsThe objective of this study was to assess the effects of in‐feed chlortetracycline (CTC) as a measure of preventing or minimizing infectious problems of reproductive failure in gilts and sows. In a farm of 400 Large White × Landrace gilts and sows with a clinical history of porcine respiratory and reproductive syndrome (PRRS) virus, the animals were treated with CTC. Treatment consisted of 10 g CTC sow/day for 15 days every 3 months. It improved the health status of sows by decreasing post‐farrowing clinical mastitis and vaginal discharges, abortions, return‐to‐oestrus and irregular return‐to‐oestrus rates. These beneficial effects had a positive impact on the performance of the litter. More piglets were born live and weaned. These positive effects improved with repeated use of CTC. The serological evidence of PRRS virus,Leptospiraspp. andChlamydiaspp. and the subsequent beneficial use of the antimicrobial agent indicate that reproductive failure, possibly resulting from the bacterial agents can be controlled with in‐feed use of broad spectrum antimicrobials.
Testicular Measurements and Daily Sperm Output of Tori and Estonian Breed Stallions
Authors: Kavak A , Lundeheim N , Aidnik M , Einarsson S 
Published: May 2003

ContentsEvaluation of testicular measurements and daily sperm output (DSO) yields valuable information for predicting the reproductive capacity of stallions. The present study evaluated testicular measurements (height, length, width and circumference) and DSO of eight Tori and eight Estonian breed stallions. One ejaculate of semen was collected daily for 10 subsequent days from each stallion. The gel‐free volume of semen was measured with a graduated glass cylinder and the sperm concentration was assessed with a Chorjajev chamber. The volume of gel‐free fraction was multiplied by the sperm concentration to give the total number of spermatozoa (TSN). The DSO was calculated as mean TSN of collection on days 8–10 in Tori breed stallions and on days 4–10 in Estonian breed stallions. The DSO of Tori breed stallions was 12.9 × 109 spermatozoa and of Estonian breed stallions 4.5 × 109 spermatozoa (p < 0.001). Testicular measurements (in cm) 1 day after the last semen collection were as follows: left testis– height 7.3, length 10.4 and width 7.3 in Tori breed stallions, and 5.9, 8.1 and 5.9, respectively, in Estonian breed stallions; right testis– height 7.4, length 10.6 and width 7.4 in Tori breed stallions, and 5.5, 7.4 and 5.3, respectively, in Estonian breed stallions. All these testicular measurements were significantly smaller in Estonian than in Tori breed stallions (p < 0.001). Testicular circumference was 45.4 and 35.4 cm in Tori and Estonian breed stallions, respectively (p < 0.001). The testicular circumference was correlated with DSO in both Estonian (p < 0.05) and Tori breed stallions (p = 0.071). The results give us valuable information on the reproductive capacity of Tori and Estonian breed stallions.
Postnatal Hypothyroidism Does Not Affect Prepubertal Testis Development in Boars
Authors: Klobucar I , Kosec M , Cebulj‐Kadunc N , Majdic G 
Published: May 2003

ContentsYoung boars were treated with propiothiouracil to induce hypothyroidism to examine its effects on postnatal testicular development. Treatments with 0.1% 4‐propyl‐2‐thiouracil (PTU) in drinking water started after weaning, at 3 weeks of age and all boars were severely hypothyroid at 6  weeks of age as determined by measuring T3 and T4 in blood plasma. Boars were castrated at different ages up to 20 weeks and their testes used for histological and immunohistochemical analyses. Although small but significant reduction in testis weight was observed from 8 to 12 weeks of age, this was not accompanied by significant difference in testicular volume. By 20 weeks of age, at the beginning of puberty, the differences in testis weights between control and treated groups of boars disappeared suggesting there is no lasting effect of hypothyroidism on postnatal development of boar testis. Immunohistochemical staining was used to determine the presence of molecular markers in both Sertoli and Leydig cells. Again, there were no differences between testes from control and treated boars in the pattern or intensity of immunostaining using antibodies against 3β‐hydroxysteroid dehydrogenase, antimullerian hormone or proliferating cell nuclear antigen (PCNA). Immunostaining with antibodies against PCNA showed interesting results as it was observed that Sertoli cells still express this marker of proliferating cells at 14 weeks of age, later than previously suggested cessation of Sertoli cell proliferation. This study suggests that hypothyroidism in boars does not have similar effects on postnatal testis development as reported in some other species.
Conception Rates after AI in Swedish Red and White Dairy Heifers: Relationship with Progesterone Concentrations at AI
Authors: Båge R 
Published: May 2003

ContentsBlood samples were collected from 211 dairy heifers at the time of field insemination [artificial insemination (AI)]. Heifers were defined as either first‐service heifers (n = 91) or third to eigth‐service heifers [presumed (third AI, n = 60)] or well‐defined repeat breeders (greater than the fourth AI, n = 60). Plasma progesterone concentrations at AI were evaluated in relation to oestrous behaviour at AI and conception rates post‐AI. Conception rates after third AI were good, but conception rates decreased markedly after fourth AI and onwards. Those heifers that did not become pregnant after AI had significantly higher basal progesterone concentrations (>0.5 nmol/l) at AI, so‐called suprabasal concentrations, compared with those which conceived after AI (irrespective of the number of AI practised). Relative risk for repeat breeding was 58% after AI performed at suprabasal progesterone concentrations, while it was 42% at basal (0.5) progesterone concentrations. Results from this field study confirm results obtained in earlier controlled studies of repeat‐breeder heifers (RBH), indicating that the current definition of repeat breeding should be retained. Analysis of suprabasal progesterone concentrations could be considered as a tool for identification of RBH, provided that heat detection and AI timing are optimal. Besides considering the direct costs involved in repeat breeding, it remains to be determined whether it would be economically beneficial to identify and exclude RBH from the breeding population.
Manipulated Mouse Embryos as Bioassay System for Water Quality Control
Authors: Elsheikh AS , Takahashi Y , Nagano M , Kanagawa H 
Published: May 2003

ContentsMouse pronuclear stage embryos with intact slit zona pellucida (manipulated) were cultured in vitro until the hatched blastocyst stage in simplex optimized medium with higher K+ concentration (KSOM) prepared with three different water types: tap, deionized reverse osmosis (D‐O) water and Milli‐Q system (M‐Q) water. The culture media were supplemented with or without protein and ethylenediaminetetraacetic acid (EDTA, disodium salt). The rates of hatched blastocysts were significantly affected (p < 0.01) by micromanipulation, protein supplement and water source. The water source has no influence (p > 0.05) on development in EDTA‐supplemented protein‐free culture media, whereas in EDTA‐ and protein‐free culture media, the water quality significantly (p < 0.001) affected the rates of development, with higher rates in media prepared with M‐Q water. The micromanipulated embryos showed higher sensitivity to the water quality (p < 0.01). It worth mentioning that the rates of hatched blastocysts in protein‐free culture media were very low (0–7.5%). Furthermore, the three different water types were analysed by measuring the electrical conductivity, inorganic ions, total organic carbon and endotoxins to evaluate the purity. M‐Q water showed the lowest levels of inorganic ion, total organic carbon and endotoxin concentrations. We concluded that manipulated mouse embryos are good system to evaluate the quality of water used in biological system.
Ovarian Follicular Dynamics in Buffalo Cows (Bubalus bubalis)
Authors: Ali A , Abdel‐Razek AK , Abdel‐Ghaffar S , Glatzel PS 
Published: May 2003

ContentsFollicular growth in Egyptian buffalo cows was monitored using genital tracts from 200 buffalo cows collected immediately after slaughter. According to the morphological appearance of the corpus luteum (CL), the corresponding oestrous cycle was divided into four stages: A (days 1–4), B (days 5–10), C (days 11–17) and D (days 18–21). Within these stages the follicular population on the ovaries was evaluated and the dominant follicle (DF) determined in all recovered ovaries. The functional status of the DF and the largest sub‐dominant follicles was examined by histological examination in 31 cases, and Radio Immunoassay (RIA) analyses for estradiol‐17β (E2) and progesterone (P4) was performed in the follicular fluid in 23 of the DF. The results showed that DFs changed their endocrine character within the stages of the oestrous cycle. The DFs between days 5 and 10 were functionally active (E2‐dominant; non‐atretic) in most of the cases. Between days 11 and day 17 half of the DFs became functionally inactive (P4‐dominant; atretic). At days 18–21 all of the DF became functionally active and non‐atretic. In the specimens that carried two large follicles one of them was regularly atretic and P4‐dominant whereas the other was non‐atretic and E2‐dominant. Between days 18 and 21 all ovaries examined showed at least one large follicle. These findings suggest that in most of the cases follicular dynamics occurs in two wave‐like patterns in the Egyptian buffalo cows.
Secretory Patterns of Prolactin in Dogs: Circannual and Ultradian Rhythms
Authors: Corrada Y , Castex G , Sosa Y , Gobello C 
Published: May 2003

ContentsThe objectives of the present study were to characterize in dogs circannual and ultradian prolactin (PRL) secretory patterns and also to compare gender differences in the ultradian period of study in the Southern hemisphere. Blood samples were collected at 15‐min intervals for 2.5 h from seven male and seven female dogs and a single monthly sampling, over a 1‐year time span, from six male dogs for the ultradian and circannual studies, respectively. Plasma PRL was measured by a homologous enzyme immunometric assay. The ultradian study evidenced PRL elevations suggesting pulsatile secretion in both genders. Significantly higher mean smoothed baseline (ng / ml [7.02 ± 1.2 vs 1.23 ± 1.0, p < 0.01]) and AUC (ng/ml * 2.5 h [25.2 ± 3.8 vs 4.4 ± 3.8, p < 0.01]) were found in females when compared with males. In the circannual study, plasma PRL concentrations did not statistically differ among the months of the year. When grouped together the 3 months with a longer daylight had significantly higher PRL concentrations than the 3 months with the shortest (2.31 ± 0.37 vs 0.96 ± 0.37, p < 0.01). The correlation between length of daylight and PRL concentrations was 0.24, p < 0.05. It is concluded that PRL does have a circannual rhythmicity and that there are ultradian gender‐related differences in the period under study in these groups of dogs. This study also demonstrates plasma PRL elevations suggesting pulsatile secretion in male dogs.
Apoptosis of Granulosa Cells: A Review on the Role of MAPK‐signalling modules
Authors: Peter AT , Dhanasekaran N 
Published: May 2003

ContentsRecent studies suggest that ovarian follicular atresia is associated with DNA fragmentation and degeneration of granulosa cells, the hallmark of programmed cell death or apoptosis. Apoptosis of granulosa cells play a major role in follicular atresia. These studies have also demonstrated the involvement of tumour suppressors, apoptotic proteins and survival factors. These factors contribute to the developmental decision as to whether the ovarian follicles mature or undergo atresia. However, the precise temporal and molecular events involved in the apoptotic pathways in this process need to be elucidated. The present report summarizes the role of Jun N‐terminal kinase (JNK), p38 mitogen activated protein kinase (p38 MAPK), and extracellular‐signal regulated kinase (ERK)‐signalling module in the regulation of pro‐ and anti‐apoptotic factors of the granulosa cells in regulating follicular atresia. The findings presented here suggest that the loss of tropic hormone support is translated into the attenuation of Raf‐1‐MAPK/ERK kinase (MEK)‐ERK‐signalling pathway of the granulosa cells and this results in the decreased phosphorylation of the pro‐apoptotic BAD.
Alterations in the DNA binding activity of transcriptional factors activator protein‐1, Sp1, and hepatocyte nuclear factor‐1 in rat jejunum during starvation and refeeding
Authors: IHARA TAKASHI , TSUJIKAWA TOMOYUKI , FUJIYAMA YOSHIHIDE , BAMBA TADAO 
Published: May 2003

AbstractBackground: The molecular processes leading to mucosal atrophy, regrowth, and functional changes with starvation and refeeding are largely unknown. There are many transcriptional factors that might be related to mucosal atrophy and proliferation. In contrast, we previously reported that H+/peptide transporter and aminopeptidase N messenger RNA in the intestinal mucosa were upregulated during starvation. Therefore, we selected and studied three transcriptional factors: activator protein (AP)‐1, Sp1, and hepatocyte nuclear factor (HNF)‐1, which not only play important roles for enterocytes proliferation, but also exist in promoter lesions of the brush border enzymes and peptide transporter.Methods: In the present study, we performed electrophoretic mobility shift assays employing AP‐1, Sp1, and HNF‐1, and evaluated the changes in the DNA binding activities in rat jejunum during starvation and refeeding.Results: Two days after starvation, the Sp1 binding activity was significantly decreased to 61.8% as compared with the control level, whereas AP‐1 was 121.4% and HNF‐1 was 77.5%. Two hours after refeeding, the AP‐1 activity was significantly increased to 175.0% as compared with the control level, and the HNF‐1 activity was significantly increased to 180.2%. In contrast, the decreased SP1 level did not recover until 24 h after refeeding.Conclusions: The DNA binding activities of these three transcriptional factors were significantly changed in the rat jejunum during starvation and refeeding. Our results provide insight into the molecular mechanisms of the transcriptional regulations associated with mucosal atrophy, regrowth, and functional changes of the jejunal epithelium in response to starvation and refeeding.
Differential, stage‐dependent expression of Hsp70, Hsp110 and Bcl‐2 in colorectal cancer
Authors: HWANG TAE SOOK , HAN HYE SEUNG , CHOI HYO KYOUNG , LEE YONG J , KIM YUN‐JEONG , HAN MI‐YOUNG , PARK YOUNG‐MEE 
Published: May 2003

AbstractBackground: The presence of hypoxic cells in solid tumors has been suggested to contribute to the malignant progression of various tumors. Recently, we reported an activation of heat shock transcription factor (HSF) and expression of heat shock proteins (Hsp) in murine tumor cells by hypoxia.Methods: To search for a possible role of Hsp in the malignant progression of human tumors, we analyzed the expression profiles of Hsp family proteins in weakly and highly metastatic human colorectal cancer (CRC) cell lines. We also analyzed the expression profiles of Bcl‐2 family proteins because the altered expression of these proteins has been demonstrated in various solid tumors.Results: In the present paper we showed among various Hsp and Bcl‐2 family proteins that the expression of Hsp70 and Hsp110 was elevated in highly metastatic CX‐1 and HT‐29 cells, while the expression of Bcl‐2 was elevated in weakly metastatic MIP‐101 and Clone A cells. Subsequent immunohistochemical analysis of 81 primary human CRC tissues demonstrated that the expression of Hsp70 and Hsp110 was highly correlated with the advanced clinical stages and positive lymph node involvement. The expression of Bcl‐2, in contrast, was correlated to the early clinical stage and negative lymphovascular invasion.Conclusion: Taken together, our study demonstrated for the first time a differential, stage‐dependent expression of Hsp70, Hsp110 and Bcl‐2 in CRC. We suggest that the molecular mechanisms underlying the differential expression of Hsp and Bcl‐2 family members deserves a more rigorous future study, the results of which might offer novel modes of rationale and strategy to predict and manipulate the malignant progression of colorectal cancers.