600 Years of Town Hall Pharmacy (raeapteek) in Tallinn, Estonia.

The Town Hall Pharmacy (Raeapteek) in the Town Hall Square of Tallinn, Estonia (N59°26'16.001'' E24°44'45.412'') was first mentioned in historical records on 8 April 1422. To our best knowledge, the Raeapteek is the oldest community pharmacy in Europe which has operated on the same premises since the beginning. There are several hypotheses about the actual opening time of Raeapteek: it is possible that the pharmacy was operating on the square of the Tallinn Town Hall as early as in 1415, 1420, 1392 or even in 1248. In the territory of present-day Estonia, two pharmacies (in Tartu first mentioned in 1430) were already in business in less than 200 kilometres from each other before community pharmacies were opened in Russia, Sweden, Finland, Norway, Denmark, Lithuania, and other cities. The Raeapteek played an essential role in the establishment of the current Estonian History Museum, the Estonian Pharmaceutical Factory, K. C. Fick's faience manufactory and other dignified institutions had their beginning at the pharmacy. Now, the pharmacy functions hand-in-hand with the museum which is supported by the city of Tallinn.

Increased retention of tau PET ligand [18F]-AV1451 in Alzheimer's Disease Psychosis.

Psychosis in Alzheimer's disease (AD) represents a distinct disease subtype with a more rapid progression of illness evidenced by an increased velocity of cognitive decline and a hastened mortality. Previous biomarker and post-mortem studies have implicated tau neuropathology as a possible mediator of the accelerated decline in AD psychosis. Tau positron emission tomography (PET) neuroimaging provides the opportunity to evaluate tau pathology in-vivo, so that clinical symptomatology can be correlated with disease pathology. [18F]-AV1451 (Flortaucipir) is a PET ligand with high affinity for insoluble paired-helical filaments (PHFs) of hyperphosphorylated tau. In order to determine whether the development of psychosis and worsened prognosis in AD is associated with an increased burden of tau pathology that can be identified with tau imaging, we identified subjects within the Alzheimer's disease neuroimaging initiative (ADNI) who had [18F]-AV1451 imaging at baseline and became psychotic over the course of the study (N = 17) and matched them 1:3 for gender, age, and education to subjects who had [18F]-AV1451 imaging at baseline and did not become psychotic (N = 50). We compared baseline [18F]-AV1451 retention, in addition to cognitive and functional baseline and longitudinal change, in those who became psychotic over the course of participation in ADNI with those who did not. Results suggest that increases in tau pathology in frontal, medial temporal, and occipital cortices, visualized with [18F]-AV1451 binding, are associated with psychosis and a more rapid cognitive and functional decline.

Adiponectin stimulates glucose uptake in mouse blastocysts and embryonic carcinoma cells.

Preimplantation embryos are sensitive to maternal hormones affecting embryonic signal transduction and metabolic functions. We examined whether adiponectin, the most abundantly secreted adipokine, can influence glucose transport in mouse embryonic cells. In mouse blastocysts full-length adiponectin stimulated glucose uptake, while no effect of globular adiponectin was found. Full-length adiponectin stimulated translocation of GLUT8 glucose transporter to the cell membrane; we did not detect significant changes in the intracellular localization of GLUT4 glucose transporter in adiponectin-treated blastocysts. To study adiponectin signaling in detail, we used embryoid bodies formed from mouse embryonic carcinoma cell (ECC) line P19. We confirmed the expression of adiponectin receptors in these cells. Similar to mouse blastocysts, full-length adiponectin, but not globular adiponectin, stimulated glucose uptake in ECC P19 embryoid bodies. Moreover, full-length adiponectin stimulated AMPK and p38 MAPK phosphorylation. These results indicate that besides AMPK, p38 MAPK is a potential target of adiponectin in mouse embryonic cells. AMPK inhibitor did not influence the adiponectin-stimulated p38 MAPK phosphorylation, indicating independent action of these two signaling pathways. In mouse embryos adiponectin acts as a hormonal regulator of glucose uptake, which becomes especially important in phases with reduced levels of circulating insulin. Our results suggest that adiponectin maintains the glucose supply for early embryos under hypoinsulinaemic conditions, for example, in mothers suffering from type 1 diabetes mellitus.

Pathogenic tau species drive a psychosis-like phenotype in a mouse model of Alzheimer's disease.

Psychotic Alzheimer's disease (AD+P) is a rapidly progressive variant of AD associated with an increased burden of frontal tau pathology that affects up to 50% of those with AD, and is observed more commonly in females. To date, there are no safe and effective medication interventions with an indication for treatment in this condition, and there has been only very limited exploration of potential animal models for pre-clinical drug development. Pathogenic tau is over represented in the frontal cortex in AD+P, especially in females. In order to develop a candidate animal model of AD+P, we employed a tau mouse model with a heavy burden of frontal tau pathology, the rTg(tauP301L)4510 mouse, hereafter termed rTg4510. We explored deficits of prepulse inhibition of acoustic startle (PPI), a model of psychosis in rodents, and the correlation between pathogenic phospho-tau species associated with AD+P and PPI deficits in female mice. We found that female rTg4510 mice exhibit increasing PPI deficits relative to littermate controls from 4.5 to 5.5 months of age, and that these deficits are driven by insoluble fractions of the phospho-tau species pSer396/404, pSer202, and pThr231 found to be associated with human AD+P. This preliminary data suggests the utility of the rTg4510 mouse as a candidate disease model of human female AD+P. Further work expanded to include both genders and other behavioral outcome measures relevant to AD+P is necessary.

Two-generation diet-induced obesity model producing mice with increased amount of body fat in early adulthood.

The aim of our study was to develop a model producing obese mice in early adulthood (4-6 weeks) based on their over-nutrition during fetal and early postnatal development. The fertilized dams of the parental generation were fed the standard diet supplemented with high-energy nutritional product Ensure Plus during gestation and lactation. Delivered weanlings were then fed with standard or supplemented diet and assessed for body fat deposits using EchoMRI at the time of early and late adulthood. Maternal over-feeding during the period before weaning had the most significant effect on obesity development in the filial generation. In weanlings, significantly higher body fat deposits and average body weight were recorded. Later, further significant increase in percentage of body fat in both male and female mice was observed. Withdrawal of the Ensure Plus supplement caused a decrease in the percentage of body fat in part of the filial generation. In offspring fed the standard diet, higher fat deposits persisted till the time of late adulthood. We conclude that this diet-induced obesity model might be used in exploration of the effects of elevated body fat on physiological functions of various organ systems during juvenile and early adulthood periods of life of a human being.

Expression of adrenergic receptors in bovine and rabbit oocytes and preimplantation embryos.

Catecholamines play an important role in embryogenesis, and data obtained in the rodent model indicate that they can act even during the preimplantation period of development. Using RT-PCR with specific oligonucleotide primers distinguishing among all members of the adrenergic receptor family, we examined expression of adrenergic receptors in bovine and rabbit oocytes, morulas and blastocysts. We found several profiles of adrenoceptor mRNA expression. Transcripts for some receptor subtypes (bovine alpha 2 receptors, rabbit α2A, α2C, ß1 and ß2 receptors) were detected at all examined stages, which suggests receptor expression throughout (or at most stages) the preimplantation developmental period. Expression in oocytes but not at later stages was found in only one adrenoceptor subtype (rabbit α1B). In contrast, mRNA for several adrenoceptors was found in embryos but not in oocytes (bovine beta adrenoceptors and rabbit α1A). Nucleotide sequences of our PCR products amplified in rabbit oocytes, and preimplantation embryos represent the first published mRNA sequences (partial sequences coding at least one transmembrane region) of rabbit α2C, ß1 and ß2 adrenoceptors. Our results suggest that the expression of adrenergic receptors can be a general feature of mammalian oocytes and preimplantation embryos. On the other hand, comparison of three mammalian species (cattle, rabbit and mouse) revealed possible interspecies differences in the expression of particular adrenoceptor subtypes. Our results support the opinion that stress mediators can act directly in cells of preimplantation embryos.

Changes in diatom patch-size distribution and degradation in a spatially self-organized intertidal mudflat ecosystem.

Self-organized spatial patterns have been proposed as possible indicators for regime shifts in ecosystems. Until now, this hypothesis has only been tested in drylands. Here, we focus on intertidal mudflats where regular spatial patterns develop in early spring from the interaction between diatom growth and sedimentation but disappear when benthic herbivore abundance increases in early summer, accompanied by a dramatic shift to a bare mudflat. We followed the patch-size distributions of diatom biofilms during this degradation process. As time progressed, we found a temporal change in the spatial configuration occurring simultaneously with the loss of the diatom-sediment feedback. This indicates a gradual failure in time of the self-organization process that underlies regular patterning in this ecosystem. The path to degradation co-occurred with the loss of the larger patches in the ecosystem, which resulted in a decrease of the truncation in the patch-size distribution. Hence, our study in mudflat ecosystems confirms the general hypothesis that spatial patterns can provide important clues about the level of degradation. Nevertheless, our study highlights the need for thorough study about the type of spatial patterns and the nature of the underlying feedbacks before a reliable assessment of ecosystem status can be made, as changes in patch-size distribution differed markedly with those observed in other ecosystems.

Trajectories of marijuana use and psychological adjustment among urban African American and Puerto Rican women.

BACKGROUND: The current longitudinal study examined the developmental patterns of marijuana use and their relationship with subsequent psychological adjustment in a community-based sample of urban African American and Puerto Rican women. METHOD: Participants were interviewed five times over a period ranging from adolescence (mean age 14.0 years) to adulthood (mean age 32.5 years). Outcome measures included depressive symptoms, anger/hostility and the presence of a substance use disorder (abuse/dependence). RESULTS: Three distinct trajectories of marijuana use were identified: non-users, increasers and quitters. Increasers reported higher levels of depressive symptoms and anger/hostility than did non-users and were more likely to meet criteria for a substance use disorder at age 32.5 years. CONCLUSIONS: Our findings indicate that early-starting long-term use of marijuana is associated with psychological maladjustment among women. Prevention efforts should emphasize the long-term cost associated with marijuana use, and that the best psychological health is reported by those who abstain from the drug.

The effect of herbicide BASTA 15 on the development of mouse preimplantation embryos in vivo and in vitro.

The aim of this study was to evaluate the possible effect of maternal poisoning by BASTA-15 on developmental capacities and quality of preimplantation embryos in a mouse model. During in vivo tests, fertilized mice were fed with various doses of BASTA-15 for several days. During in vitro tests, isolated embryos were cultured in a medium with the addition of herbicide or its main compound glufosinate ammonium. Stereomicroscopic evaluation of embryonic pools obtained from treated dams showed that BASTA-15 at dose 58 µl/kg bw negatively affected their ability to reach the blastocyst stage. Moreover, as shown by morphological evaluation, based on cell counting and cell death assay, even the application of herbicide at the lowest dose (approx. 1/100 LD50) had a negative effect on obtained embryo quality. In vitro tests proved the direct ability of BASTA-15 to negatively affect embryo growth and quality. On the other hand, the addition of glufosinate ammonium at equivalent concentrations (from 0.015 to 15 µg/ml) had almost no damaging effect on embryos. It was harmful only at very high doses. Results show that maternal intoxication with BASTA-15 might affect the development of preimplantation embryos and suggest that the responsibility for this effect lies probably not solely with glufosinate ammonium, but in combination with the herbicide's secondary compounds.

The effect on preimplantation embryo development of non-specific inflammation localized outside the reproductive tract.

The aim of this study was to evaluate the possible effect of non-specific acute inflammation localized outside the reproductive tract on the quality of preimplantation embryos. In fertilized female mice two experimental models of inflammation were used-trinitrobenzene sulfonic acid colitis and carrageenan paw oedema. Inflammation was induced during the cleavage period of embryo development and embryos were collected at 92 h post hormonal synchronization. Stereomicroscopical evaluation of in vivo derived embryos showed that the presence of inflammation in the maternal body did not affect their basic developmental abilities, i.e. there were no significant differences in the proportion of early blastocysts, morulas, slowly developing embryos and degenerates between embryonic pools obtained from mothers with induced inflammation and control mothers. In the next step, non-degenerated embryos from all mothers were cultured in vitro under standard conditions for another 24 h, and the average cell number (fluorescence DNA staining) and the incidence of cell death (fluorescence viability staining combined with TUNEL assay) were evaluated. The majority of cultured embryos reached expanded blastocyst stage. There were no significant differences in the average cell numbers of blastocysts, but blastocysts derived from mothers with induced inflammation showed a significantly higher incidence of dead cells in both experiments. The majority of dead cells were of apoptotic origin. These results show that non-specific inflammation localized outside the reproductive tract has no detrimental effect on the preimplantation embryo growth; however it can affect the embryo quality.

Effects of borneol and thymoquinone on TNBS-induced colitis in mice.

Components of plant essential oils have been reported to have health benefit properties, including antioxidative, anti-tumour, antimicrobial, anti-stress, and immunomodulative activities. We examined the anti-inflammatory effects of thymoquinone, the active ingredient in the volatile oil of Nigella sativa seeds, and borneol, the active component of Salvia officinalis essential oil, on TNBS-induced colitis in mice. Thymoquinone was added to the commercial diet at a concentration of 0.05 % and borneol at two concentrations (0.09% and 0.18%) and fed to ICR mice 5 days before induction of TNBS colitis. Seven days after TNBS administration the mice were killed and macroscopic and histological scores were evaluated. Cytokine mRNA expression in colonic tissue was assessed using quantitative realtime RT-PCR. We did not detect any significant changes in macroscopic and histological scores between experimental and control groups, but we observed a significant decrease in proinflammatory cytokine (IL-1beta and IL-6) mRNA expression in colon tissue in the 0.09% and 0.18% borneol-treated groups of mice in comparison to the control group. Surprisingly, we were not able to confirm anti-inflammatory effects of thymoquinone in TNBS colitis. In conclusion, our data show that borneol is able to significantly suppress proinflammatory cytokine mRNA expression in colonic inflammation, although no significant morphological changes are visible.

Chronological appearance of spontaneous and induced apoptosis during preimplantation development of rabbit and mouse embryos.

This study was undertaken to obtain specific information on the characteristics of spontaneous and induced apoptosis during preimplantation development of rabbit in vivo and in vitro developed embryos and mouse in vitro embryos. After reaching appropriate developmental stages, embryos were transferred into culture media with or without apoptotic inductor (actinomycin D 500 ng/mL) and cultured for 10 h. The identification of apoptotic cells was based on morphological assessment of nuclei and on detection of specific DNA degradation, phosphatidylserine redistribution and active caspase-3 under fluorescence microscope. Our experiments proved that apoptosis is a frequent physiological event occurring during normal preimplantation development. A high number of untreated rabbit and mouse blastocysts contained at least one apoptotic cell. Rabbit embryos showed a lower incidence of spontaneous apoptosis. Treated blastocysts of both species responded to the presence of apoptotic inductor by significant decrease in the average number of blastomeres and significant increase in the incidence of apoptotic cell death. The occurrence of spontaneous apoptosis during earlier preimplantation development was sporadic and its presence was observed only at stages following embryonic genome activation (at 4-cell stage and later in mouse, at 16-cell and morula stage in rabbit). The susceptibility of embryos at early stages to the apoptotic inductor was much lower. The presence of actinomycin D did not increase the incidence of apoptotic embryos or apoptotic cells. Nevertheless, it slowed down embryo growth and triggered earlier appearance of some apoptotic features (at the 6-cell stage in rabbit). The results show that the occurrence of both spontaneous and induced apoptosis in preimplantation embryos is stage- and species-specific.

Dose- and time-dependent effects of TNFalpha and actinomycin D on cell death incidence and embryo growth in mouse blastocysts.

This study was undertaken to obtain information about characteristics of different types of induced apoptosis in preimplantation embryos. Freshly isolated mouse blastocysts were cultured in vitro with the addition of two apoptotic inductors--TNFalpha and actinomycin D--at various doses and times. The average number of nuclei and the percentage of dead cells were evaluated in treated embryos. Classification of dead cells was based on morphological assessment of their nuclei evaluated by fluorescence microscopy, the detection of specific DNA degradation (TUNEL assay), the detection of active caspase-3 and cell viability assessed by propidium iodide staining. The addition of both apoptotic inductors into culture media significantly increased cell death incidence in blastocysts. Their effects were dose and time dependent. Lower concentrations of inductors increased cell death incidence, usually without affecting embryo growth after 24 h culture. Higher concentrations of inductors caused wider cell damage and also retarded embryo development. In all experiments, the negative effect of actinomycin D on blastomere survival and blastocyst growth was greater than the effect of TNFalpha. Furthermore, the addition of actinomycin D into culture media increased cell death incidence even after 6 h culture. Differences resulted probably from diverse specificity of apoptotic inductors. The majority of dead cells in treated blastocysts were of apoptotic origin. Morphological and biochemical features of apoptotic cell death induced by both TNFalpha and actinomycin D were similar and had homologous profile. In blastomeres, similarly to somatic cells, the biochemical pathways of induced apoptosis included activation of caspase-3 and internucleosomal DNA fragmentation.

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.

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.

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.

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.

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.

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.