Biomedical subjects

J Koppel

Publications and source records attributed to J Koppel.

At least 19 recordsLinked to original sources

PubMed2006

Effects of selected plant essential oils on the growth and development of mouse preimplantation embryos in vivo.

Plant essential oils (EOs) have been reported to have health benefit properties and their preventive and therapeutic use in animals is expected to increase in the future. We evaluated the influence of five essential oils obtained from plant species which are known to have positive antimicrobial, antioxidative and anti-inflammatory effects--sage EO from Salvia officinalis L. (Lamiaceae), oregano EO from Origanum vulgare L. (Lamiaceae), thyme EO from Thymus vulgaris L. (Lamiaceae), clove EO from Syzygium aromaticum L. (Myrtaceae) and cinnamon EO from Cinnamomum zeylanicum Blume (Lauraceae) on the growth and development of mouse preimplantation embryos in vivo. Essential oils were added to commercial diet at concentrations of 0.25% for sage EO, thyme EO, clove EO, cinnamon EO and 0.1% for oregano EO, and fed to ICR female mice for 2 weeks ad libitum. Females were then mated with males of the same strain. Embryos obtained on Day 4 of pregnancy at the blastocyst stage were stained by morphological triple staining (Hoechst, PI, Calcein-AM) and evaluated using fluorescent microscopy. The effects of essential oils were estimated by the viability of embryos, number of nuclei and distribution of embryos according to nucleus number. Cinnamon EO significantly decreased the number of nuclei and the distribution of embryos according to nucleus number was significantly altered. Sage EO negatively influenced the distribution of embryos according to nucleus number. Clove and oregano EOs induced a significantly increased rate of cell death. Only thyme EO had no detectable effects on embryo development. In conclusion, none of the essential oils had any positive effect on embryo development, but some of them reduced the number of cells and increased the incidence of cell death.

Animals↗

PubMed2003

Nucleolus in apoptosis-induced mouse preimplantation embryos.

Apoptosis may occur in early embryos in which the execution of essential developmental events has failed. Thus the initiation of the apoptotic mechanism may be related to activation of the embryonic genome. In this way, developmentally incompetent cells or whole embryos are eliminated. It is likely that some link exists between failed resumption of rRNA synthesis and the incidence of apoptosis in cleaving embryos. In this context, decreased developmental potential in cleaving nucleotransferred embryos is consistent with cell loss, and very likely due to programmed cell death. The effects of apoptosis inducers on cleaving embryos have not been characterised in comparable detail to that in the case of somatic cells. Early embryos provide a very good model for study of these processes because of the specificity of rRNA transcription resumption after fertilization. In our experiments three apoptosis inducers (staurosporin 10 mM, actinomycin D 0.05 mg/ml and camptothecin 0.1 mg/ml) were used in a culture medium for 15 h at the 4-cell stage (day 2) of mouse embryos, followed by further development in a pure culture medium until fixation on days 3, 4 and 5. In staurosporin-induced embryos, light microscopy immunostaining of nucleolar proteins (fibrillarin, Nopp140, protein B23) did not reveal changes in nucleolar morphology on day 3. On days 4 and 5, more compact (roundish) nucleoli (in comparison with controls) were observed. The embryos treated with camptothecin displayed a similar staining pattern to those with staurosporin at each day. In actinomycin-D-treated embryos, marked changes in nucleolar appearance were visible as early as day 3. These changes in nucleolar morphology consisted of loss of the reticulation appearance and fragmentation of nucleoli. In addition to nucleolar changes, significantly decreased cell proliferation was observed. The induced embryos did not reach the blastocyst stage. The number of blastomeres was decreased, and staining with Hoechst 33342 revealed a significant percentage of apoptotic nuclei (condensed/fragmented nuclei) from day 4.

Animals↗

PubMed2003

Expression of serotonin receptors in mouse oocytes and preimplantation embryos.

Serotonin receptors have been found in several reproductive organs as well as in the central nervous system. Serotonin-binding sites have been demonstrated in duck ovarian follicles and the testis, hamster ovaries, human granulosa cells and mouse placenta. Local production of serotonin by the rat ovary, oviduct, uterus and testis has also been reported. We analyzed the expression of three types of serotonin receptors: 5-HT1B, 5-HT2C and 5-HT1D by reverse transcription-polymerase chain reaction in mouse unfertilized oocytes and preimplantation embryos from zygotes to the blastocyst stage in vivo. Transcripts for 5-HT1B and 5-HT2C serotonin receptors were detected neither in unfertilized oocytes nor at any stages of in vivo developing preimplantation embryos. Serotonin 5-HT1D receptor mRNA was present in unfertilized oocytes, zygotes, 2-cell embryos, compacted morulae and in vivo produced expanded blatocysts. The expression of the mRNA 5-HT1D serotonin receptor was also detected in blastocysts cultured in vitro. When added to the culture medium, specific serotonin 5-HT1D agonist sumatriptan (1 microM) significantly inhibited the development of mouse embryos cultured in vitro. Demonstration of the expression of 5-HT1D serotonin receptor in mouse oocytes and preimplantation embryos supports the idea of a functional serotonin (5-HT1D) receptor in early mammalian development.

Animals↗

PubMed2001

Cloning of a novel biogenic amine receptor-like G protein-coupled receptor expressed in human brain.

We report the cloning and sequence of a novel gene, BALGR, which is coding for a candidate G protein-coupled receptor (GPCR) that is distantly related to the histamine, adrenergic, serotonin and dopamine receptors. The coding region of the human BALGR gene predicts a seven transmembrane domain receptor of 451 amino acids. BALGR has 42% amino acid identity to a Medaka fish 'orphan' GPCR. BALGR gene has been conserved throughout the mammalian evolution as indicated by Southern blot analysis. BALGR gene has been assigned to chromosome 1 by typing a panel of somatic cell hybrids and its exon/intron organization has been predicted. As determined by semiquantitative RT-PCR, expression of BALGR is relatively the highest in the human brain. A high level of BALGR transcript is also detected in testes. Within the brain, Northern blot analysis revealed relatively high expression in frontal and temporal lobes, occipital pole, amygdala and hippocampus. The preferential expression of BALGR in the areas of the human brain associated with cognition, learning and memory, and its conservation in evolution, indicate a potentially important biological function for this biogenic amine-like receptor and its putative neurotransmitter ligand.

Amino Acid Sequence↗

PubMed2000

The influence of insulin on the in vitro development of mouse and bovine embryos.

To further investigate the role of insulin during preimplantation embryo development, we compared the effects of insulin on the development of mouse and bovine preimplantation embryos and on cell proliferation during culture in vitro in simplex media. The influence of insulin on the development of mouse zygotes was determined during cultivation in mSOF medium, alone or supplemented with glucose. Similarly, the effects of insulin on the bovine preimplantation embryo development were studied in mSOF medium. The addition of insulin into mSOF medium enhanced significantly the number of cells per mouse blastocyst. Moreover, when mSOF medium was supplemented with insulin and 0.2 mmol x l(-1) glucose, the percentage of hatched blastocysts and the mean cell number of mouse blastocysts were significantly higher. Insulin had no significant effect on the development of bovine embryos, produced by in vitro fertilization of in vitro matured oocytes. Neither the rates of developing embryos nor the mean number of cells in blastocysts were different in comparison with control embryos. Our results suggest that the in vitro development of mouse embryos could be enhanced by the addition of insulin to the culture medium and is further improved by the addition of glucose. In contrast to this our results indicate that insulin has no detectable beneficial effect on the preimplantation development of bovine embryos in mSOF medium.

Animals↗

PubMed1999

Sequence and tissue distribution of a novel G-protein-coupled receptor expressed prominently in human placenta.

We report here a novel gene, NPGPR, which encodes a G-protein-coupled receptor (GPCR) that is most similar to the peptide receptor subfamily. The coding region of the human NPGPR gene predicts a seven transmembrane domain receptor of 522 amino acids and having a relatively large N-terminus of 147 amino acids. The NPGPR sequence has 30-33% amino acid identity to NPY receptors and similar percentage identity to orexin receptors (32%). Northern blot analysis reveals an abundant 1.5 kb NPGPR transcript in human placenta. Semi-quantitative RT-PCR determined additional sites of expression in thymus, testis and small intestine. These sites of mRNA expression suggest a potential role for the novel receptor in signaling to tissues undergoing active cell growth and differentiation. At low levels, NPGPR message is detectable in several other tissues including spleen, prostate, brain, heart, ovary, colon, kidney, lung, liver, and pancreas.

Amino Acid Sequence↗

PubMed1999

Cellular and subcellular localization of stathmin during oocyte and preimplantation embryo development.

Stathmin is a 19 kDa cytosolic phosphoprotein, proposed to act as a relay integrating diverse intracellular signaling pathways involved in regulation of cell proliferation, differentiation, and function. To gain further information about its significance during early development, we analyzed stathmin expression and subcellular localization in mouse oocytes and preimplantation embryos. RT-PCR analysis revealed a low expression of stathmin mRNA in unfertilized oocytes and a higher expression at the blastocyst stage. A fine cytoplasmic punctuate fluorescent immunoreactive stathmin pattern was detected in the oocyte, while it evolved toward an increasingly speckled pattern in the two-cell and later four- to eight-cell embryo, with even larger speckles at the morula stage. In blastocysts, stathmin immunoreactivity was fine and intense in inner cell mass cells, whereas it was low and variable in trophectodermal cells. Electron microscopic analysis allowed visualization with more detail of two types of stathmin immunolocalization: small clusters in the cytoplasm of oocytes and blastocyst cells, together with loosely arranged clusters around the outer membrane of cytoplasmic vesicles, corresponding to the immunofluorescent speckles in embryos until the morula stage. In conclusion, it appears from our results that maternal stathmin is accumulated in the oocyte and is relocalized within the oocyte and early preimplantation embryonic cell cytoplasm to interact with specific cytoplasmic membrane formations. Probably newly synthesized, embryonic stathmin is expressed in the blastocyst, where it is localized more uniformly in the cytoplasm mostly of inner cell mass (ICM) cells. These expression and localization patterns are probably related to the particular roles of stathmin at the successive steps of oocyte maturation and early embryonic development. They further support the proposed physiologic importance of stathmin in essential biologic regulation.

Animals↗

PubMed1998

Preimplantation embryo development in ICR mice after streptozotocin treatment.

To investigate the significance of impaired insulin secretion on preimplantation embryo development, outbred ICR female mice received a single injection of streptozotocin 130 mg (low) and 160 mg (subdiabetic) kg(-1), 14-17 days before fertilization. Preimplantation embryos were collected on day 3 of pregnancy, four to eight-cell embryos were cultured in vitro 48 h (day 5) and their cell number was estimated. After spontaneous ovulation, the significantly different distribution pattern in comparison with the controls was detected only in preimplantation embryos isolated from subdiabetic (160 mg x kg(-1) streptozotocin) mice. Furthermore, the incidence of degenerated embryos was significantly increased after 48 h in vitro cultivation. The analysis of cell number distribution in embryos after cultivation in vitro indicated a significant delay in cell proliferation in both experimental groups (130 and 160 mg x kg(-1) streptozotocin) in comparison with control mice. After superovulation, the only significant difference was found in the distribution pattern of embryos isolated on day 3 of pregnancy from subdiabetic (160 mg x kg(-1) streptozotocin) mice. No significant differences were found after embryo cultivation in vitro. It could be concluded that, in outbred ICR mice, lower streptozotocin treatment (130 mg x kg(-1)) influenced only cell distribution of in vitro cultured embryos after spontaneous ovulation. In ICR mice, marked changes in preimplantation embryo development were detected only after subdiabetic (160 mg x kg(-1)) streptozotocin treatment. During in vitro cultivation delayed effects of impaired insulin secretion resulted in an increase of embryo degeneration at the time after the third mitotic cleavage. Our results indicate that the effects of impaired maternal insulin secretion on preimplantation embryo development in mice are marked and consistent after spontaneous ovulation. Superovulation apparently disguises subtle changes in preimplantation embryo development after low and subdiabetic streptozotocin treatment.

Animals↗

PubMed1997

Intravenous ondansetron for postsurgical opioid-induced nausea and vomiting. S3A-255 Study Group.

The use of opioids for postoperative analgesia may be limited by side effects such as nausea and vomiting. Because ondansetron, a selective serotonin type 3 (5-hydroxytryptamine [5-HT3]) antagonist, is effective for chemotherapy and general anesthesia-induced nausea and vomiting, we hypothesized that it may also be effective for opioid-induced nausea and vomiting. ASA physical status I-III patients undergoing regional anesthesia were eligible for the study. Those who requested an antiemetic after postsurgical opioid administration were randomized to receive a single dose of ondansetron (0.1 mg, 4 mg, or 16 mg intravenously [I.V.]) or placebo in a double-blind fashion. Emetic episodes, nausea and pain ratings, and adverse events were recorded for 24 h after study drug administration. Patient satisfaction scores were obtained 24 h after study drug infusion. A significantly (P < 0.05) larger proportion of patients treated with ondansetron 4 mg and 16 mg experienced no emetic episodes, received no rescue antiemetic, and completed the study compared with placebo. Nausea scores and patient satisfaction scores in the ondansetron 16-mg group were significantly (P < 0.05) more favorable than in the placebo group. Postsurgical pain scores did not differ among groups. The incidence of adverse events was similarly low across groups. The results of this study support our hypothesis that I.V. ondansetron is effective for postsurgical opioid-induced nausea and vomiting.

Adult↗

PubMed1996

Effects of impaired maternal insulin secretion on preimplantation embryo development in ICR mice.

To investigate the significance of impaired insulin secretion on preimplantation embryo development, outbred ICR female mice received an injection of a single dose of streptozotocin 200 mg.kg-1 14-17 days before fertilization. Oocytes were collected 24-26 h after hCG injection. Morphological evaluation revealed a lower percentage of oocytes with second polar bodies from streptozotocin-treated females in comparison with controls. Furthermore, in this group the incidence of degenerated embryos significantly increased after 120 h in vitro cultivation. Insulin (5 U per 100 g b.w.) administered twice daily to streptozotocin-treated mice significantly improved the Embryonic development. Morphological analysis of oocyte maturation in streptozotocin-treated mice showed no significant differences in comparison with control mice. It could be concluded that marked changes in preimplantation embryo development were detected in outbred ICR mice after streptozotocin administration and this process was partly reversible by insulin treatment. Furthermore, it was shown that the process of fertilization was negatively influenced and that during in vitro cultivation the delayed effects of impaired insulin secretion resulted in an increase of embryo degeneration at the time following the third mitotic cleavage.

Animals↗

PubMed1995

Localization of fibrillarin and nucleolin in nucleoli of mouse preimplantation embryos.

The localization of fibrillarin and nucleolin in the nuclei of mouse two-cell, four-cell, and eight-cell embryos has been studied using immunofluorescent staining with specific antibodies. In all of these cleavage stages, both antigens were associated exclusively with the peripheral region of the nucleolus precursor bodies (NPBs). The original speckled fluorescent staining pattern in the early two-cell stage was progressively changed into a continuous fluorescent-positive layer localized in the cortex of the NPBs in the four-cell embryos. The compact central area of NPBs was never stained. Both proteins were colocalized in the same substructures of developing nucleoli. In order to analyze the interaction of chromatin with NPBs, DNA structures were specifically immunolabelled. At the time of resumption of nucleolar transcription (in the two-cell mouse embryo), DNA was detected at the periphery of, but not penetrating into, NPBs. Our results confirm the view that the cortical region of NPBs could represent a nucleolonemal area involved in the resumption of nucleolar transcription in the early mouse embryo.

Animals↗

PubMed1995

The protein kinase C inhibitor H7 blocks phosphorylation of stathmin during TPA-induced growth inhibition of human pre-B leukemia REH6 cells.

The human pre-B acute lymphoblastic leukemia cell line REH6 was used to analyze the regulation of a ubiquitous intracellular phosphoprotein stathmin (Mr 19,000, pl = 5.6-6.2). We demonstrated by 32P-labeling that the short (1 h) treatment of the REH6 cells with the tumor promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), resulted in a rapid phosphorylation of at least three (P1, P2 and P3) stathmin isoforms without an alteration of stathmin isoform expression. Furthermore, Western blot analysis with specific antiserum showed that the prolonged period (48 h) of TPA treatment partially reduced protein levels particularly of two (N2 and P2) stathmin isoforms. The potent and relatively specific protein kinase C (PKC) inhibitor, 1,(5-isoquinolinesulphonyl)2methylpiperasine dihydrochloride (H7), partially inhibited these TPA effects, whereas the specific calmodulin inhibitor R24571 (calmidazolium) had no effect upon these events. Our findings suggest that stathmin phosphorylation in REH6 cells could be in part mediated by PKC activation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1995

Effects of impaired insulin secretion on the fertilization of mouse oocytes.

We have studied the effect of moderately impaired maternal insulin secretion on oocyte chromosomal constitution, fertilization and zygote DNA synthesis. Female mice were injected with a single dose of streptozotocin (65 mg/kg) 14 days before fertilization/ovulation. Zygotes/oocytes were recovered from control and subdiabetic mice on day 1 of pregnancy. Compared with control animals, subdiabetic females showed a significant difference in the proportion of zygotes/oocytes. The subdiabetic mothers had a lower percentage of zygotes and a higher percentage of unfertilized and degenerated oocytes in comparison with control animals. The investigation of [3H]thymidine incorporation did not show any influence of the maternal subdiabetes on the initial zygote DNA synthesis. An analysis of the ovulated oocytes at the metaphase II stage isolated from subdiabetic mice did not reveal increased chromosomal anomalies in comparison with the controls. Control and subdiabetic mothers had a similar percentage of oocytes with a normal haploid set of chromosomes, and the incidence of aneuploidy/diploidy did not differ significantly. These observations suggest that insulin changes in subdiabetic mothers had a deleterious influence on oocyte fertilization in mice, but apparently they did not have any effect on the nuclear events.

Animals↗

PubMed1994

Effects of healthy pseudopregnant milieu on development of two-cell subdiabetic mouse embryos.

Female mice were injected with a single dose of streptozotocin (65 mg kg-1) 14-17 days before fertilization to investigate the significance of impaired insulin secretion induced by subdiabetic streptozotocin treatment on preimplantation embryo development. Subdiabetic mice (streptozotocin-treated) had significantly different glucose tolerance from that of control animals, despite similar basal glycaemia. Morphological analysis of preimplantation embryos collected on day 2 of pregnancy revealed no significant changes in the number of two-cell embryos recovered from streptozotocin-treated females compared with controls. Two-cell embryos were transferred into the oviducts of healthy, synchronous pseudopregnant females and recovered 24-28 h later. Morphological evaluation revealed a significantly greater percentage of degenerated embryos from streptozotocin-treated females than from control females. Morphological analysis of preimplantation embryos collected on day 2.5 of pregnancy revealed no significant changes in the number of two- to four-cell embryos recovered from streptozotocin-treated females compared with controls, but there was a significant increase in the number of degenerated embryos in streptozotocin-treated females that did not receive insulin therapy. Insulin (1-1.5 iu per 100 g) administered twice a day to streptozotocin-treated mice significantly improved the altered development of embryos in both experiments. It is possible that the impaired insulin secretion in female mice adversely affected the growth of preimplantation embryos. Almost half of the morphologically normal two-cell embryos isolated from subdiabetic females were incapable of development to the eight-cell stage even in a non-diabetic maternal environment. the morphologically distinct degenerative changes were first detected at the time of the second mitotic cleavage.

Animals↗

PubMed1994

The longitudinal growth of tibia in oestradiol-treated and restrictedly fed immature male rats.

The effect of oestradiol administration and restricted feeding on longitudinal tibia growth was investigated in immature male rats. The restrictedly fed animals had a significantly longer tibia, greater thickness of the growth plate, faster rate of longitudinal tibial growth as well as the greater rate of [methyl-3H]thymidine incorporation into the growth plate of the tibia compared with oestradiol-treated animals. The results indicate that, in immature male rats, exogenous oestradiol can decrease the longitudinal growth of the tibia (at least partly due to inhibition of cell proliferation in the growth plate) independently of its anorexic effect.

Animals↗

PubMed1993

Induction of stathmin expression during liver regeneration.

Stathmin is a 19 kDa cytoplasmic phosphoprotein proposed to act as a relay for signals activating diverse intracellular regulatory pathways. After two-thirds partial hepatectomy, the concentration of stathmin reached a peak between 48 and 72 hours, comparable to the levels observed in neonatal liver, at about 10 times the basal adult level. Stathmin then decreased to basal levels within 7 days, more rapidly than during postnatal tissue development (7 weeks), with no detectable change in its phosphorylation state. Interestingly, the mRNA for stathmin reached a peak much earlier than the protein, at 24 hours posthepatectomy, and decreased to a still detectable level until 96 hours after hepatectomy. Altogether, the present results further support the generatility of the implication of stathmin in regulatory pathways of cell proliferation and differentation during normal tissue development and posttraumatic regeneration.

Animals↗

PubMed1993

[Body weight and skeletal growth in female rats after ovariectomy].

The body weight gain and growth of tail and tibia were investigated in ovariectomized female rats to ascertain whether the increased skeletal growth after ovariectomy takes place at the same time as the increased body weight gain. Female rats were ovariectomized on the 30th day of age; half of them was killed on the 60th day of age and the other half was killed on the 130th day of age. The body weight and tail length were significantly higher in the ovariectomized females than in intact females from the 60th day of age (Figs. 1, 2). The ovariectomized animals had higher body weight gain and tail length increment, in comparison with intact animals, mainly between the 40th and 60th day of age (Tabs. I, II). After the 90th day of age the body weight gain and tail length increment were no longer significantly higher in ovariectomized animals than in intact animals, although the ovariectomized females maintained the significantly higher body weight and tail length till the end of the experiment (130th day of age). The length of tibia was larger in ovariectomized animals if compared with controls, on the 60th as well as on the 130th day of age. However, the rate of longitudinal growth of tibia, measured (by tetracycline method) between the 57th and 59th day and between the 127th and 129th day of age, was significantly higher in ovariectomized animals only in the first period of measurement (Tab. III).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Immunolocalization of DNA in preimplantation mouse embryos.

Distribution of embryonic DNA in mouse preimplantation embryos was studied by the immunoelectron microscopic method with colloidal gold. The embryos (one-cell, early or late two-cell, four-cell) were sampled separately, and immunogold labelling has been performed on thawed ultrathin cryosections. Condensed chromatin blocks were labelled very intensively. DNA labelling was predominantly visible over peripheral chromatin blocks and over small patches of chromatin localized throughout the nucleus of one-cell embryo. DNA distribution appeared to be more extended in the whole nucleus of early two-cell embryo. A few labelled chromatin clumps were observed to be associated with prenucleolar body (nucleolar precursor body--NPB) in this stage. Convex-shaped electron-light areas (fibrillar centres?) were found at the periphery of NPB in the late two-cell stage. These areas were labelled by scattered individual gold particles. In reticulated nucleolar regions (detected in four-cell embryos) immunolabelling appeared as individual gold particles present over the periphery of areas with loosely arranged material (fibrillar centres) surrounded by a denser component (dense fibrillar component). These consecutive changes are correlated with nucleologenesis and with the onset of transcriptional activity. We conclude that at the onset of nucleolar transcriptional activity condensed chromatin does not penetrate the NPB of mouse two-cell embryo.

Animals↗