Maternal primary imprinting is established at a specific time for each gene throughout oocyte growth

Primary imprinting during gametogenesis governs the monoallelic expression/repression of imprinted genes in embryogenesis. Previously, we showed that maternal primary imprinting is disrupted in neonate-derived non-growing oocytes. Here, to investigate precisely when and in what order maternal primary imprinting progresses, we produced parthenogenetic embryos containing one genome from a non-growing or growth-stage oocyte from 1- to 20-day-old mice and one from a fully grown oocyte of adult mice. We used these embryos to analyze the expression of eight imprinted genes: Peg1/Mest, Peg3, Snrpn, Znf127, Ndn, Impact, Igf2r, and p57(KIP2). The results showed that the imprinting signals for each gene were not all imposed together at a specific time during oocyte growth but rather occurred throughout the period from primary to antral follicle stage oocytes. The developmental ability of the constructed parthenogenetic embryos was gradually reduced as the nuclear donor oocytes grew. These studies provide the first insight into the process of primary imprinting during oocyte growth.

Vasopressin and epinephrine are equally effective for CPR in a rat asphyxia model

Epinephrine has been administered as a drug essential for cardiopulmonary resuscitation (CPR). Recently, vasopressin has been reported to be more effective than epinephrine for CPR in a ventricular fibrillation (VF) model. As a different myocardial pathology is speculated to exist between the VF model and the asphyxia model, we investigated whether vasopressin is also effective in a rat asphyxia model. Twenty-one Sprague-Dawley male rats were divided into three groups: vasopressin 0.8 U/kg (Vaso-Gr), epinephrine 0.05 mg/kg (Epi-Gr), and saline same volume as the other two drugs (Sal-Gr). Five minutes after suffocation induced by obstruction of the tracheal tube, CPR was performed using each drug. Although only one animal survived (17%) in the Sal-Gr, 6/7 (85%) survived in both Vaso-Gr and Epi-Gr (P<0.01). Vasopressin is as effective as epinephrine for CPR in asphyxia-induced rats.

Localization of gelatinolytic activity can be detected in breast cancer tissues by film in situ zymography

BACKGROUND

Extracellular matrix-degrading proteinases secreted by malignant tumor cells have been thought to play an essential role in the processes of invasion and metastasis. However, existence and localization of gelatinase activity in breast cancer tissues have not been clarified.

METHODS

We developed a novel film for highly reproducible detection and the localization of gelatinolytic activity. This film has a gelatin layer with a constant thickness 7 microm, and adequate crosslinking to control the speed of degradation by proteases. Cryosections of several breast cancer tissues were put on this gelatin film and incubated for 16 hrs at 37 degrees C. After staining with ponceau 3R dye, the digested area was evaluated under light microscopy.

RESULTS

Digestion of gelatin was detected in more than 90%of breast cancer specimens, although it varied in degree and area for each case. In most cases, the gelatinolytic activity was located within cancer nests, and was not detected in stromal cells surrounding cancer cells. The gelatinolytic activity was inhibited by 1,10-phenanthroline, an inhibitor of matrix metalloproteinases (MMPs).

CONCLUSIONS

In this study, the localization of net MMP activity was confirmed in breast cancer nest using film in situ zymography. Detailed analysis on the relationship between the strength or distribution of MMP activity and malignancy are anticipated in the future.

Promoting mechanism of menthol derivative, 1-O-ethyl-3-buthylcyclohexanol, on the percutaneous absorption of ketoprofen

Menthol derivatives were synthesized and evaluated for their promoting activity on the percutaneous absorption of ketoprofen and skin irritation in vivo, choosing O-ethylmenthol (MET) as the mother compound. The compound having a C-3 positionned n-butyl group (1-O-ethyl-3-n-buthylcyclohexanol, OEBC) indicated the most promoting activity and caused relatively little skin irritation. In order to understand enhancement mechanism of OEBC an in vitro permeation study of ketoprofen was performed. The time course of the cumulative amounts of drug permeated through the rat skin exhibited a linear relation after an initial lag time. This was analyzed in membrane diffusion model and the diffusion and partition parameters of ketoprofen were estimated. Both parameters were remarkably enhanced when a hydrogel containing a small quantity of OEBC (0.5%) was applied. Furthermore, to clarify the site of action of OEBC, we also investigated in vitro permeation study of ketoprofen employing different skins of state, reversed skin and stratum corneum stripped skin. When OEBC was added to the hydrogels which were applied to the reversed and stripped skins, almost no changes of the flux were observed compared with the control (without OEBC). These results suggested that the site of action of OEBC was stratum corneum. Morphological changes of the stratum corneum surface were microscopically observed with 0-2% OEBC. The spaces between the stratum corneum cells treated with 0.5-2% OEBC became extended and the shape of each cell became clear. This may suggest that the site of action of OEBC was the intercellular of stratum corneum. Furthermore, an electron spin resonance study was performed to investigate the effect of OEBC on the intercellular lipid bilayer fluidity of the stratum corneum and the rotational correlation times were calculated. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) were used as the spin label. In use of OEBC, the fluidity of TEMPO labeled the stratum corneum lipid increased as the addition of OEBC. The results suggested that OEBC promote the penetration of drugs by enhancing fluidity of the local lipid bilayers around TEMPO.

Two consecutive zinc fingers in Sp1 and in MAZ are essential for interactions with cis-elements

The zinc finger proteins Sp1 and Myc-associated zinc finger protein (MAZ) are transcription factors that control the expression of various genes. Regulation of transcription by these factors is based on interactions between GC-rich DNA-binding sites (GGGCGG for Sp1 and GGGAGGG for MAZ) and the carboxyl-terminal zinc finger motifs of the two proteins. Sp1 and MAZ have three and six zinc fingers, respectively, and the details of their interactions with cis-elements remain to be clarified. We demonstrate here that Sp1 and MAZ interact with the same GC-rich DNA-binding sites, apparently sharing DNA-binding sites with each other. We found that the DNA binding activities of Sp1 and MAZ depended mainly on consecutive zinc fingers, namely the second and third zinc fingers in Sp1 and the third and fourth zinc fingers in MAZ. Furthermore, the interactions of the zinc finger proteins with the same cis-elements appear to play a critical role in the regulation of gene expression. It seems plausible that two consecutive zinc finger motifs in a zinc finger protein might be essential for interaction of the protein with DNA.

Simultaneous optimization based on artificial neural networks in ketoprofen hydrogel formula containing O-ethyl-3-butylcyclohexanol as percutaneous absorption enhancer

The influence of the amounts of additives including 1-O-ethyl-3-n-butylcyclohexanol (OEBC), diisopropyl adipate (DIA), and isopropanol (IPA) on the penetration rate (R(p)) of ketoprofen from hydrogels through rat skin in vivo was investigated. Skin irritation evoked by the application of hydrogels was evaluated based on a microscopic observation of skin cross-sections. Both optimization techniques incorporating an artificial neural network (ANN) and a second-order polynomial regression analysis were applied to the optimization of ketoprofen hydrogel formulations. Findings indicated that the R(p) and total irritation score (TIS) of the skin were predicted quantitatively as a function of quantities of OEBC, DIA, and IPA, employing ANN. In contrast, the prediction ability of the polynomial regression equation was somewhat poorer compared with that of ANN. The observed results of R(p) and TIS in the optimal formulation coincided well with the predictions in the simultaneous optimization technique incorporating ANN.

Identification of a new imprinted gene, Rian, on mouse chromosome 12 by fluorescent differential display screening

Systematic screening of differentially expressed genes among androgenetic, parthenogenetic, and normal embryos by means of fluorescent differential display revealed five imprinted genes. One of them, named Rian, was expressed exclusively from the maternal allele and was closely linked to an imprinted gene, Meg3(Gtl2), mapped to the distal end of chromosome 12. The Rian transcript did not have any apparent open reading frame, and its transcript was exclusively localized to the nucleus.

The binding of thymus leukemia (TL) antigen tetramers to normal intestinal intraepithelial lymphocytes and thymocytes

Thymus leukemia (TL) Ags belong to the family of nonclassical MHC class I Ags and can be recognized by both TCRalphabeta and TCRgammadelta CTL with TL, but not H-2 restriction. We previously reported that the CTL epitope is TAP independent, but the antigenic molecule(s) presented by TL has yet to be determined. In the present study, TL tetramers were prepared with T3(b)-TL and murine beta(2)-microglobulin, not including antigenic peptides, and binding specificity was studied. CTL clones against TL Ags were stained with the T3(b)-TL tetramer, and the binding shown to be CD3 and CD8 dependent. Normal lymphocytes from various origins were also studied. Surprisingly, most CD8(+) intraepithelial lymphocytes derived from the small intestines (iIEL), as well as CD8(+) and CD4(+)CD8(+) thymocytes, were stained, while only very minor populations of CD8(+) cells derived from other peripheral lymphoid tissues, such as spleen and lymph nodes, were positive. The binding of T3(b)-TL tetramers to CD8(+) iIEL and thymocytes was CD8 dependent, but CD3 independent, in contrast to that to TL-restricted CTL. These results altogether showed that TL-restricted CTL can be monitored by CD3-dependent binding of T3(b)-TL tetramers. In addition, CD3-independent T3(b)-TL tetramer binding to iIEL and thymocytes may imply that TL expressed on intestinal epithelium and cortical thymocytes has a physiological function interacting with these tetramer(+)CD8(+) T lymphocytes.

Disruption of imprinted expression of U2afbp-rs/U2af1-rs1 gene in mouse parthenogenetic fetuses

The present study shows that the U2afbp-rs gene, a paternally expressed imprinted gene, is activated and expressed in a biallelic manner from maternal alleles in parthenogenetic mouse fetuses on day 9.5 of gestation. The mean expression was detected to be 88% (31-134%) of that in control biparental fetuses, using real-time quantitative reverse transcription and polymerase chain reaction. This disrupted expression of the gene was associated with changes in the chromatin structure but not with the methylation pattern in the regulation region. The present results show that parental specific expression of imprinted genes is not always maintained in uniparental embryos. This suggests that both parental genomes are necessary to establish parental specific expression of the U2afbp-rs gene.

Comparison of anti-tumor responses against TL positive lymphoma induced by skin grafting and dendritic cell immunization

When the skin of Tg.Con.3-1 transgenic mice expressing the TL (thymus leukemia) antigen in most tissues is grafted on syngeneic C3H mice, it is rejected, and a cytotoxic T cell (CTL) response against the TL antigen is induced. In this study, we first demonstrated that growth of TL positive lymphoma is suppressed in mice immunized by skin grafting. Immunization with bone marrow derived dendritic cells (DCs) from Tg.Con.3-1, was also found to be associated with an anti-tumor response, but less potent than skin grafting. Relative CTL precursor frequency with DC immunization was also approximately only one third that of skin grafting. The numbers of IFN-gamma producing cells in responder CD8 and CD4 T cell populations were higher with DC immunization than with skin grafting. However, DC immunization seems to induce non-specific immune responses, as re-stimulation with TL negative C3H spleen cells resulted in induction of almost half the number observed with TL positive cells. Thus, the actual number of IFN-gamma producing cells in specific responses to TL is not necessarily larger than with skin grafting immunization. The present results altogether suggest that DC immunization is capable of inducing an anti-tumor reaction, but also possibly unwanted immune responses. In vitro monitoring of specific and non-specific responses in the immune system, thus, is of particular importance for future development of cancer immunotherapy.

Limited association between a catechol-O-methyltransferase (COMT) polymorphism and breast cancer risk in Japan

BACKGROUND

Catechol-O-methyltransferase (COMT) inactivates the estradiol metabolites, 2-hydroxy estradiol and 4-hydroxy estradiol. To date, three studies in Caucasians and one study in Chinese have been conducted to determine the association with breast cancer risk of a functional polymorphism (G-to-A, Val158Met) of this enzyme, but the results were inconsistent. In order to examine the impact of this polymorphism on breast cancer risk in Japan, a case-control study was conducted, at Aichi Cancer Center Hospital.

METHODS

The cases were 150 patients with histologically confirmed breast cancer who had been diagnosed within 4 years before enrollment at this hospital. The controls were 165 non-cancer patients, mainly from the gastroenterology and breast surgery clinics at the hospital. COMT-H (Val) is the wild-type allele, with high enzyme activity, while the COMT-L (Met) allele has low activity. Genotyping was conducted by a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method.

RESULTS

The allele frequency of COMT-L was 36.0% for cases and 33.0% for controls. Age-adjusted odds ratios relative to the COMT-HH genotype were 1.46 (95% confidence interval [CI], 0.90-2.36) for COMT-HL, and 0.99 (95% CI, 0.49-2.02) for the COMT-LL genotype. Significant odds ratios were not observed for any subgroup stratified by menopausal status, age at menarche, age at birth of first child, body mass index, and breast cancer history of mother and/or sister(s).

CONCLUSION

The present study suggested that any association of the COMT polymorphism with breast cancer risk is limited in Japanese.

Evaluation and structure-activity relationship of synthesized cyclohexanol derivatives on percutaneous absorption of ketoprofen using artificial neural network

The effect of 35 newly synthesized O-ethylmenthol (MET) derivatives on percutaneous absorption of ketoprofen was investigated in rats. In order to understand the relationship between the structure of compounds and promoting activity (structure-activity relationship), an artificial neural network (ANN) was employed. In the in vivo percutaneous absorption study, male Wistar rats, weighing 160-180 g, were used. The apparent penetration rate (Rp) was estimated based on a pharmacokinetic model with a constant rate of penetration through the skin after a lag time. As an index of the promoting activity of each compound, an enhancement factor (Ef), defined as follows, was used: Ef=Rp(with enhancer)/Rp(without enhancer). An irritation evoked on rat skin was microscopically judged at the end of the in vivo percutaneous absorption experiment and evaluated as a total irritation score (TIS). Ef and TIS were selected as output variables to determine the ANN structure. Calculated logP, molecular weight, steric energy (SE), van der Waals area, van der Waals volume, dipole moment, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were used as factors to determine the structural nature of cyclohexanol derivatives. Among these parameters, logP, SE and LUMO significantly affected the prediction of Ef and TIS. The predicted values of Ef and TIS coincided well with in vivo percutaneous absorption experimental values. However, results observed with a linear regression method were poor compared with the ANN approach. The contribution index of logP was approximately 50% in the prediction of Ef, suggesting that lipophilicity among physicochemical properties contributes most of the promoting activity of these compounds.

SEREX analysis of gastric cancer antigens

Stomach cancer is the major malignancy in Japan and one of the most common cancers worldwide. To establish the basis for an immunotherapeutic approach to stomach cancer, we have initiated an analysis of stomach cancer antigens recognized by human immunoglobulin G (IgG) antibodies using SE-REX, a powerful expression cloning method developed by Dr. M. Pfreundschuh's group. Five stomach cancer cDNA libraries have been screened with autologous patient sera: one moderately differentiated adenocarcinoma; two poorly differentiated adenocarcinomas; and two scirrhous-type poorly differentiated adenocarcinomas of Borrmann type 4, the most devastating form of stomach cancer. Based on the reactivities of clones with autologous IgG antibodies, an average of 50 independent clones from each library and a total of 297 clones were isolated. DNA sequencing revealed that these 297 clones were derived from 136 different genes. Comparison of the 136 genes to sequences in DNA databases showed that 95 are previously identified genes and 41 are newly identified in this study. The antigens are derived from various genes including a chimeric gene between E-cadherin and an unknown gene Y, AKT oncogene, genes overexpressed in stomach cancers, genes of which the transcripts are alternatively or aberrantly spliced, and genes known to be involved in autoimmune diseases. Thus stomach cancer patients can generate an immune response against a surprisingly diverse set of gene products. To identify antigens potentially useful in the diagnosis and therapy of gastric cancer, all 136 genes were tested for their reactivities with a panel of sera from 44 gastric cancer patients (17 women and 27 men, aged 35-81 years) and with a panel of sera from 100 control individuals with no previous history of cancer but some of whom had gastritis (55 women and 45 men, aged 30-69 years). Eleven antigens showed reactivity only with a certain proportion of cancer patient sera but not with any control sera. An additional 12 antigens elicited antibody production at a much higher frequency in cancer patients than in control individuals. To evaluate the clinical usefulness of these antigens we are now examining their expression in normal and malignant tissues.

The epitope detected by cytotoxic T lymphocytes against thymus leukemia (TL) antigen is TAP independent

Thymus leukemia (TL) antigens belong to the family of MHC class Ib antigens. We have shown in our previous studies that they serve as transplantation antigens, and can be recognized by both TCR alpha beta and TCR gamma delta cytotoxic T lymphocytes (CTL) with TL but not H-2 restriction. Although TL are known to be expressed TAP independently, it is unclear whether peptide loading on TL molecules is necessary for the formation of CTL epitopes. In the present study, we first showed that TL expression is beta(2)-microglobulin (beta(2)m)-dependent but TAP1 independent by flow cytometric analysis of thymocytes from beta(2)m- or TAP1-deficient mice crossed with TL transgenic mice expressing Tla(a)-3-TL on their thymocytes. Subsequently, we investigated the epitope recognized by CTL derived from C3H mice immunized with skin from a transgenic mouse expressing T3(b)-TL ubiquitously. Bulk CTL lines against TL from primary mixed lymphocyte cultures showed comparable cytotoxicity against T3(b)-TL transfectants of TAP2-deficient murine RMA-S grown at 37 degrees C to that against those grown at 25 degrees C. Furthermore, TCR alpha beta and TCR gamma delta CTL clones against TL recognized TL expressed on T3(b)-TL transfectants of RMA-S and Drosophila melanogaster cells having broad defects in peptide loading of MHC, and lysed these target cells. These results together indicate that TL-specific CTL populations primarily recognize epitopes expressed TAP independently.

No association of the 5' promoter region polymorphism of CYP17 with breast cancer risk in Japan

To examine the association between breast cancer risk and a T-to-C substitution polymorphism at the 5' promoter region of CYP17, a case-control study was conducted at Aichi Cancer Center Hospital in Japan. Subjects were 144 histologically confirmed breast cancer patients diagnosed in the past 4 years and 166 hospital controls without cancer. Allele frequency among controls was 44.9% (95% confidence interval; 39.5 - 50.2) for C allele. Odds ratio (OR) of the polymorphism relative to TT-genotype was 0.97 (0.58 - 1.64) for TC-genotype and 0.81 (0.39 - 1.68) for CC-genotype. Subgroup analyses revealed that the OR was not statistically significant for the subgroups stratified by interval after diagnosis, age at menarche, age at first birth, menopausal status, body mass index, and mother / sisters' history of breast cancer. Consistent with previous studies conducted in other countries, the 5' promoter region polymorphism of CYP17 affected breast cancer risk of Japanese women to a limited extent. Although this is not a large-scale case-control study with population controls, these findings provide enough information to discourage further studies on the association between this polymorphism and breast cancer risk in Japan at large, and suggest that this polymorphism is useless for breast cancer risk estimation.

Formula optimization of theophylline controlled-release tablet based on artificial neural networks

Formulation of the controlled-release tablet containing theophylline was optimized based on the simultaneous optimization technique in which an artificial neural network (ANN) was incorporated. As model formulations, 16 kinds of theophylline tablets were prepared. The amounts of Controse, the mixture of hydroxypropylmethyl cellulose with lactose, cornstarch and compression pressure were selected as causal factors. The release profiles of theophylline were characterized as the sum of the fast and slow release fractions. The initial weight, the rate constant in the fast release fraction and the rate constant in the slow release fraction were estimated as release parameters. A set of release parameters and causal factors were used as tutorial data for ANN and analyzed using a computer. Based on the plasma concentration profiles of theophylline predicted by the pharmacokinetic analysis in humans, a desirable set of release parameters was provided. The simultaneous optimization was performed by minimizing the generalized distance between the predicted values of each response and the desirable one that was optimized individually. The optimization technique incorporating ANN showed a fairly good agreement between the observed values of release parameters and the predicted results.

Imprint switching for non-random X-chromosome inactivation during mouse oocyte growth

In mammals, X-chromosome inactivation occurs in all female cells, leaving only a single active X chromosome. This serves to equalise the dosage of X-linked genes in male and female cells. In the mouse, the paternally derived X chromosome (X(P)) is imprinted and preferentially inactivated in the extraembryonic tissues whereas in the embryonic tissues inactivation is random. To investigate how X(P) is chosen as an inactivated X chromosome in the extraembryonic cells, we have produced experimental embryos by serial nuclear transplantation from non-growing (ng) oocytes and fully grown (fg) oocytes, in which the X chromosomes are marked with (1) an X-linked lacZ reporter gene to assay X-chromosome activity, or (2) the Rb(X.9)6H translocation as a cytogenetic marker for studying replication timing. In the extraembryonic tissues of these ng/fg embryos, the maternal X chromosome (X(M)) derived from the ng oocyte was preferentially inactivated whereas that from the fg oocyte remained active. However, in the embryonic tissues, X inactivation was random. This suggests that (1) a maternal imprint is set on the X(M) during oocyte growth, (2) the maternal imprint serves to render the X(M) resistant to inactivation in the extraembryonic tissues and (3) the X(M) derived from an ng oocyte resembles a normal X(P).

Relation of transesophageal echocardiographic findings to subtypes of cerebral infarction in patients with atrial fibrillation

BACKGROUND

Transesophageal echocardiography (TEE) has been used to identify the potential risk for cardiogenic embolism in patients with atrial fibrillation (AF). However, ischemic stroke in patients with AF is not always attributable to embolism. Identification of the risk of embolic versus atherothrombotic stroke should lead to the optimal individualized management of patients with AF.

HYPOTHESIS

The goal of the study was to determine the relation between cortical infarction and perforating infarction and TEE findings in patients with AF.

METHODS

We investigated the clinical usefulness of TEE in the risk stratification of clinical subtyping of the cerebral infarctions which were divided into two territories of the cortical branch (cortical infarction due to embolism) and deep perforators (perforating infarction due to atherothrombosis). Left atrial spontaneous echo contrast, peak flow velocity in the left atrial appendage, and generalized atherosclerosis as estimated by the intima-media wall thickness of the thoracic aorta were assessed by TEE in 118 consecutive patients with either paroxysmal (n = 44) or chronic (n = 74) AF. All patients underwent either brain computed tomography or magnetic resonance imaging.

RESULTS

Cortical and perforating infarction was found in 39 and 18% of patients, respectively. The grade of spontaneous echo contrast was higher in patients with than in those without cortical infarction (p < 0.05). In contrast, patients with perforating infarction showed significant increase in the aortic wall thickness when compared with patients without perforating infarction (p < 0.05). In addition, multivariate logistic analysis revealed that spontaneous echo contrast was an independent predictor of cortical infarction, while intima-media wall thickness of the aorta, hypertension, and age were useful in predicting the risk of perforating infarction.

CONCLUSIONS

Transesophageal echocardiography has a potential role in the risk stratification for cortical and perforating infarction in patients with AF.

p300/CBP-dependent and -independent transcriptional interference between NF-kappaB RelA and p53

p53 and NF-kappaB RelA are activated by various genotoxic agents and mutually suppress each other's ability to activate transcription, most likely through competition for transcriptional coactivators such as CBP or p300. However, we found that the inhibition by RelA of p53 transcriptional activity is not completely restored by CBP/p300 overexpression and that a p53 mutant can not suppress RelA activity despite of its ability to bind CBP/p300. In the present study, we further present evidence that these two transcriptional factors directly interact both in vivo and in vitro. These results therefore indicate that the cross transcriptional interference between p53 and RelA is partly caused by the direct interaction between these two transcription factors which is mediated by their dimerization/tetramerization domains and results in inhibition of each other's transcriptional activity. Finally, cells derived from RelA knockout mice showed enhanced p53 transcriptional activity, suggesting that this cross transcriptional interference is physiologically important in cellular response to genotoxic stress.

Effect of synthesized cyclohexanol derivatives using L-menthol as a lead compound on the percutaneous absorption of ketoprofen

L-Menthol was selected as a lead compound to synthesize new candidates for percutaneous absorption enhancers. In a previous study, O-ethylmenthol (MET) was the most effective compound and caused relatively little skin irritation. To develop more effective compounds, mono- or disubstitute groups of cyclohexane with an O-ethyl group were synthesized. Some 35 compounds were synthesized and evaluated for their promoting activity and effect on skin. An in vivo percutaneous absorption study was performed using rats with hydrogel containing ketoprofen and each of the synthesized compounds. The plasma concentration of ketoprofen was determined after the application of hydrogel to the abdominal area of rats. The apparent penetration rate (R(p)) was estimated based on the pharmacokinetic model with a constant rate of penetration through the skin after the lag time. The 2-compartment model was applied to the data obtained from the iv administration. As an index to evaluate the promoting activity of each enhancer, an enhancement factor (E(f)) was defined as follows: E(f) = R(p) (with enhancer)/R(p) (without enhancer). Irritation to skin was pathologically evaluated. The treated area of rat abdominal skin was excised after the in vivo experiment using total irritation score (TIS). The compound having a C-3 positioned iso-butyl group on the chemical structure was the most effective and caused relatively little irritation among mono-substituted compounds. In the case of di-substituted compounds, all had the same effect as or a stronger effect than MET. Furthermore, the promoting activity almost corresponded to irritation. To estimate log P, one of the physicochemical properties of molecules, a computer program 'CAChe' was employed. The log P was calculated using the atom typing scheme. Multiple regression analysis revealed that the relations between E(f) or TIS and log P were parabolic. It was suggested that the optimum logP value reflects the promoting activity to enhance percutaneous absorption of ketoprofen.

Post-implantation development of mouse androgenetic embryos produced by in-vitro fertilization of enucleated oocytes

We report here on the precise ability of mouse androgenetic embryos produced by in-vitro fertilization of enucleated oocytes to develop to day 9.5 of gestation when cultured with M16 and CZB media. Androgenetic embryos cultured with CZB rather than M16 medium developed to the blastocyst stage in a more significant proportion (56.6% versus 45.0%, P < 0.001). However, after cavitation, the rate of cell proliferation of androgenetic embryos cultured with CZB medium was significantly decreased (P < 0.05). Embryo transfer experiments showed that blastocysts cultured with M16 medium were superior to those cultured with CZB medium in their ability to develop to 9.5-day-old fetuses (28.1% versus 11.1%, P < 0.001). These results showed that the present procedure for producing androgenetic mouse embryos is reliable and that M16 medium is superior for culturing the embryos. Fetal sexing by polymerase chain reaction (PCR) also demonstrated that both XX and XY embryos develop to 9.5-day fetuses at theoretical rates (1:2). This is the first finding that mouse XX androgenones survive after implantation.

Evaluation of skin damage caused by percutaneous absorption enhancers using fractal analysis

Fractal analysis of the cross-sectional morphology of rat skin was conducted to evaluate pathologic changes evoked by percutaneous absorption enhancers. Male hairless rats (WBN/Ht-ILA), 8 weeks old, weighing 160 to 180 g were used. Under anesthetization, glass cells (10-mm inner diameter) were attached to the rats' abdomens, and test solutions containing various mixtures of the percutaneous absorption enhancers, sodium lauryl sulfate, isopropanol, 2-methyl-1-butanol, and sodium myristate were applied. Six hours after application, the solutions were removed and the abdominal skin was excised. Skin cross sections were analyzed with a charge-coupled device (CCD) camera. Image data taken by the CCD camera were fed into a desktop digital computer; then the fractal dimension of each skin cross section was determined on the basis of the box-counting algorithm. A pathologic study was also performed on the skin treated with the test solution. All sections of skin were examined with an optical photo microscope. Pathologic findings were classified into five levels. The total irritation score (TIS) was defined as the summation of damage levels in all regions. Only with the administration of hydrogel containing 2-methyl-1-butanol or sodium lauryl sulfate were positive values of TIS observed. However, the TIS values were independent of the concentration of these components. The most severe skin damage was evoked by application of sodium lauryl sulfate. Noticeable skin damage was also seen with 2-methyl-1-butanol. No irritation to the skin resulted from treatment with isopropanol or sodium myristate. When test solution containing sodium lauryl sulfate was applied to the skin, a remarkable increment in fractal dimensions was noted. This may suggest that the structure of the skin was greatly compromised as a result of sodium lauryl sulfate application. Although no change in fractal dimension was observed as a result of application of the test solution containing only 25% isopropanol, the fractal dimension of skin cross section gradually increased with increasing concentrations of isopropanol, 2-methyl-1-butanol or sodium myristate in the test solutions. The increment of fractal dimension was around 0.4. Thus, the skin structure was also altered by the application of high concentrations of these compounds. Although the relevance to humans is not known, fractal analysis of skin structure is thought to be useful as a novel method for detecting skin damage that is brought about by the application of percutaneous absorption enhancers.

Epigenetic modifications necessary for normal development are established during oocyte growth in mice

The ability of maternal chromatin to support full-term development is attained during oocyte growth. The aim of this study was to identify when during the growth phase the maternal chromatin developed the capacity to support term development. Mature metaphase II-arrested oocytes that contained chromatin from oocytes at different stages of oocyte growth were constructed by micromanipulation. The oocytes were fertilized in vitro, developed to the blastocyst stage in vitro, and transferred to recipients to assay developmental potential. The results demonstrate, firstly, that the origin of the maternal chromatin has no effect on the rate of oocyte maturation, fertilization, or development to the blastocyst in vitro. Secondly we demonstrate that maternal chromatin is first competent to support development to term during the latter half of oocyte growth when oocytes are 60-69 microm in diameter in juvenile mice or 50-59 microm in diameter in adult mice. These data show that epigenetic modifications necessary for postimplantation development occur during a specific phase of oocyte growth.