A step-by-step approach for assessing acute oral toxicity without animal testing for additives of quasi-drugs and cosmetic ingredients

Animal testing of cosmetic ingredients and products has been banned in the European Union since 2013. However, in Japan, the application of new quasi-drugs requires the generation of data on acute oral toxicity through animal testing. A weight of evidence approach for assessing oral toxicity was challenged. This approach used a combination of safety data, including a neutral red uptake cytotoxicity assay using BALB/c3T3 cells (3T3-NRU cytotoxicity assay), which can assess the acute oral toxicity of quasi-drugs or cosmetic ingredients. We conclude that the step-by-step approach can be used to assess test substances that cause low acute oral toxicity, such as the median lethal dose (LD 50) > 2000 mg/kg, thereby avoiding animal testing.

BepiColombo mission confirms stagnation region of Venus and reveals its large extent

The second Venus flyby of the BepiColombo mission offer a unique opportunity to make a complete tour of one of the few gas-dynamics dominated interaction regions between the supersonic solar wind and a Solar System object. The spacecraft pass through the full Venusian magnetosheath following the plasma streamlines, and cross the subsolar stagnation region during very stable solar wind conditions as observed upstream by the neighboring Solar Orbiter mission. These rare multipoint synergistic observations and stable conditions experimentally confirm what was previously predicted for the barely-explored stagnation region close to solar minimum. Here, we show that this region has a large extend, up to an altitude of 1900 km, and the estimated low energy transfer near the subsolar point confirm that the atmosphere of Venus, despite being non-magnetized and less conductive due to lower ultraviolet flux at solar minimum, is capable of withstanding the solar wind under low dynamic pressure.

Improved performance of the SH test as an in vitro skin sensitization test with a new predictive model and decision tree

Demands for the elimination and replacement of animal experiments for cosmetic safety assessment have increased in recent years. Evaluation of skin sensitization, however, is a critical issue in cosmetic safety assessment. The SH test is an in vitro skin sensitization test method that evaluates protein binding of chemical substances, which is an important event in skin sensitization. We previously verified the technical transferability and between-laboratory reproducibility of the SH test, a domestic test method for which no scientific research has been conducted, and improved the protocol, but also noted some unresolved issues. Therefore, in the present study, we successfully improved the operational efficiency and clarity of the final judgment of the SH test by (i) developing a new decision-making system that can make a final judgment without statistical processing, (ii) changing the statistical method, and (iii) evaluating and determining the maximum number of repetitions necessary for optimal efficiency. The improved SH test was verified by comparing it with existing test methods already adopted by the Organization for Economic Cooperation and Development. The results of this study demonstrated excellent performance of the improved SH test, with high reproducibility, reliable predictability, and good operational efficiency. The predictive performance of the improved method does not differ significantly from that of the conventional method, although it is clearer and more efficient. Therefore, the results of the present improved method are consistent with those obtained using the conventional method, with higher efficiency.

Enhancing between-facility reproducibility of the SH test as an in vitro skin sensitization test by the improved test method

There has been an increased demand to eliminate animal experiments and to replace the experiments with alternative tests for assessing the safety of cosmetics. The SH test is an in vitro skin sensitization test that evaluates the protein binding abilities of a test substance. Skin sensitization must be evaluated by multiple test methods. The SH test uses the same cell line and measuring instruments as the human Cell-Line Activation Test (h-CLAT), which is one of the test methods used to evaluate different key events and is listed in the OECD test guidelines. There are cost advantages to usher the SH test into facilities that are already running the h-CLAT. The SH test is conducted only at a facility that has developed the SH test because studies on the between-facility reproducibility and validity have not been performed. Therefore, to verify the transferability of the SH test and the between-facilities reproducibility, we evaluated the reproducibility of the SH test results at three facilities, including the development facility. After an initial round of testing, the protocol was refined as follows to improve reproducibility among the three facilities: i) determine the optimum pH range, ii) change the maximum applicable concentration of water-soluble substances, and iii) define the appropriate dispersion conditions for evaluating hydrophobic substances. These refinements markedly enhanced the between-facility reproducibility (from 76.0% to 96.0%) for the 25 substances evaluated in this study. This study confirmed that the SH test is an effective skin sensitization test method with high technical transferability and between-facility reproducibility.

Large anisotropic deformation of skyrmions in strained crystal

Mechanical control of magnetism is an important and promising approach in spintronics. To date, strain control has mostly been demonstrated in ferromagnetic structures by exploiting a change in magnetocrystalline anisotropy. It would be desirable to achieve large strain effects on magnetic nanostructures. Here, using in situ Lorentz transmission electron microscopy, we demonstrate that anisotropic strain as small as 0.3% in a chiral magnet of FeGe induces very large deformations in magnetic skyrmions, as well as distortions of the skyrmion crystal lattice on the order of 20%. Skyrmions are stabilized by the Dzyaloshinskii-Moriya interaction, originating from a chiral crystal structure. Our results show that the change in the modulation of the strength of this interaction is amplified by two orders of magnitude with respect to changes in the crystal lattice due to an applied strain. Our findings may provide a mechanism to achieve strain control of topological magnetic structures based on the Dzyaloshinskii-Moriya interaction.

Rikkunshito induces gastric relaxation via the β-adrenergic pathway in Suncus murinus

BACKGROUND

Rikkunshito (RKT) is a gastroprotective herbal medicine. In this study, we investigated the role of RKT in the relaxation of the gastric body (fundus and corpus) and antrum.

METHODS

We used Suncus murinus, a unique small model animal with similar gastrointestinal motility to humans and dogs. RKT was added at 0.1, 1.0, and 5.0 mg/mL to induce relaxation in vitro; the outcome measure was the intensity of relaxation. The number of spontaneous antral contractions in the absence or the presence of RKT was also counted.

KEY RESULTS

Rikkunshito induced the relaxation of the gastric body and antrum and decreased the number of spontaneous antral contractions in a dose-dependent manner. The responses to RKT (1.0 mg/mL) were not affected by pretreatment with atropine, N-nitro-l-arginine methyl ester, ritanserin, or ondansetron. On the other hand, timolol almost completely reversed the relaxation induced by RKT (1.0 mg/mL) on the gastric body and antrum and the occurrence of the spontaneous antral contractions. Both butoxamine, a β(2) -adrenoreceptor antagonist, and L 748337, a β(3) -adrenoreceptor antagonist, but not CGP 20712, a β(1) -adrenoreceptor antagonist, significantly reversed the RKT-induced (1.0 mg/mL) gastric relaxation.

CONCLUSIONS & INFERENCES

These results indicate that RKT stimulates and modulates gastric relaxation through β(2) - and β(3) -adrenergic, but not β(1) -adrenergic, pathways in S. murinus.

The prevalence of and factors related to calcium pyrophosphate dihydrate crystal deposition in the knee joint

OBJECTIVES

The purpose of this study was to reveal the accurate prevalence and related factors to the presence of calcium pyrophosphate dihydrate (CPPD) crystal deposition in cadaveric knee joints.

DESIGN

Controlled laboratory study.

METHODS

Six hundred and eight knees from 304 cadavers (332 male knees and 276 female knees, formalin fixed, Japanese anatomical specimens) were included in this study. The average age of the cadavers was 78.3 ± 10.7 years. Knees were macroscopically evaluated for the existence of CPPD, and the depth of cartilage degeneration of the femoro-tibial joint following the Outerbridge's classification. CPPD crystal was confirmed under Fourier transform infrared spectroscopy (FTIR) analysis using light microscopy. Statistical analysis was performed to reveal the correlation between the occurrence of CPPD deposition in the knee joint and gender, age, and the depth of cartilage degeneration of the femoro-tibial joint.

RESULTS

The prevalence of grossly visible CPPD crystal was 13% (79 knees). In all of these knees, CPPD crystal was confirmed under FTIR analysis. Statistical analysis showed significant correlation between the occurrence of CPPD deposition and gender (P < 0.001), and depth of cartilage degeneration in the femoro-tibial joint (P < 0.001). In the cartilage degeneration positive knees (Over grade 3 in Outerbridge's classification), average age of CPPD deposition knee was significantly higher than CPPD negative knees.

CONCLUSIONS

In this study, the prevalence of CPPD deposition disease was evaluated in a relatively large sample size of cadaveric knees. The prevalence of CPPD deposition disease was 13%, and was significantly correlated with the subject's age, gender, and severity of cartilage degeneration in the femoro-tibial joint.

Effects of alpha-amylase and its inhibitors on acid production from cooked starch by oral streptococci

This study evaluated acid production from cooked starch by Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis and Streptococcus mitis, and the effects of alpha-amylase inhibitors (maltotriitol and acarbose) and xylitol on acid production. Streptococcal cell suspensions were anaerobically incubated with various carbohydrates that included cooked potato starch in the presence or absence of alpha-amylase. Subsequently, the fall in pH and the acid production rate at pH 7.0 were measured. In addition, the effects of adding alpha-amylase inhibitors and xylitol to the reaction mixture were evaluated. In the absence of alpha-amylase, both the fall in pH and the acid production rate from cooked starch were small. On the other hand, in the presence of alpha-amylase, the pH fell to 3.9-4.4 and the acid production rate was 0.61-0.92 micromol per optical density unit per min. These values were comparable to those for maltose. When using cooked starch, the fall in pH by S. sanguinis and S. mitis was similar to that by S. mutans and S. sobrinus. For all streptococci, alpha-amylase inhibitors caused a decrease in acid production from cooked starch, although xylitol only decreased acid production by S. mutans and S. sobrinus. These results suggest that cooked starch is potentially acidogenic in the presence of alpha-amylase, which occurs in the oral cavity. In terms of the acidogenic potential of cooked starch, S. sanguinis and S. mitis were comparable to S. mutans and S. sobrinus. Alpha-amylase inhibitors and xylitol might moderate this activity.

Diurnal change of thyroid-stimulating hormone mRNA expression in the rat pars tuberalis

Thyroid-stimulating hormone (TSH)-producing cells (TSH cells), which account for a large fraction of the cells in the rat pars tuberalis (PT), have been found to express MT1 melatonin receptor and mammalian clock genes at high densities. Although these findings suggest that TSH production in the rat PT is regulated by melatonin and/or the biological clock, there have been no studies focusing on the diurnal change and regulation mechanism of TSH production in the rat PT. Therefore, in the present study, we examined diurnal changes of in TSH beta and alpha-glycoprotein subunit (alpha GSU) mRNA expression and TSH immunoreactivity (-ir) in the rat PT, and also examined the relationship between melatonin and TSH production in vivo. Both TSH beta mRNA expression and alpha GSU mRNA expression in the PT showed diurnal variations: the expression levels were lowest at the light phase [Zeitgeber time (ZT)4] and high at the dark phase (ZT12 and ZT20). TSH-ir in the PT showed the lowest level at ZT4, as was found for mRNA expression. Interestingly, TSH-ir, which was confined to the Golgi apparatus at ZT4, spread to the cytoplasm, and most of the TSH cells in the PT were uniformly immunostained in the cytoplasm at ZT20. Despite the fact that chronic administration of melatonin suppressed TSH beta and alpha GSU mRNA expression, TSH-ir in the PT was significantly enhanced. These findings results clearly show that there are diurnal changes in TSH expression and accumulation in rat PT-TSH cells and suggest that these fluctuations are regulated by melatonin.

Rapid microglial activation induced by traumatic brain injury is independent of blood brain barrier disruption

Following CNS injury, microglia respond and transform into reactive species exhibiting characteristic morphological changes that have been termed "activated" or "ameboid" microglia. In an attempt to establish that microglial reactions induced immediately after injury are caused by intrinsic mechanisms rather than infiltration of blood and its constituents, oxygenized Ringer's solution was perfused into the cerebral circulation of rats so that the circulating blood could be eliminated prior to injury induction. Under artificial respiration, a catheter was inserted from the cardiac apex into the ascending aorta, and oxygenized Ringer's solution was immediately perfused with a pulsatile blood pump, resulting in wash out of the circulating blood from the brain within 1 min. Subsequently, a cortical contusion was induced in the unilateral parietal cortex using a controlled cortical impact (CCI) device. At 5 min following the injury, the brain was fixed by perfusion of fixative through the catheter and removed. Coronal vibratome sections were then processed for CR3 immunohistochemistry to examine the microglial activation. It appeared that microglial activation with both morphological transformation and an increase in CR3 immunoreactivity was induced throughout the hemisphere ipsilateral to the injury side exclusively, even in rats with elimination of circulating blood. The microglial reactions did not differ substantially from those observed in the control rats with extensive BBB disruption. The present results thus provide direct evidence that the microglial activation induced immediately after injury is independent of infiltration of circulating blood induced by concurrent BBB disruption.

Difference in the xylitol sensitivity of acid production among Streptococcus mutans strains and the biochemical mechanism

Xylitol inhibits the glycolysis and growth of Streptococcus mutans, but to different degrees among strains. Thus, we studied the biochemical mechanism through which the inhibition varies, using S. mutans strains ATCC 31989, NCTN 10449, and NCIB 11723, which are highly sensitive, moderately sensitive, and resistant to xylitol, respectively, under strictly anaerobic conditions such as those found in deep layers of dental plaque. Xylitol (30 mM) decreased the rate of acid production from glucose (10 mM) in ATCC 31989, NCTC 10449, and NCIB 11723 by 86, 26, and 0%, respectively. The activities of the xylitol : phosphoenolpyruvate phosphotransferase system (PEP-PTS) relative to those of glucose : PEP-PTS were 120, 16, and 3%, respectively. In ATCC 31989 and NCTC 10449, intracellular accumulation of xylitol 5-phosphate and decreases of fructose 1,6-bisphosphate and glucose 6-phosphate were observed. Furthermore, in the presence of xylitol (30 mM), glucose : PEP-PTS activities decreased by 34, 17, and 0%, respectively. These findings indicated that the higher the xylitol : PEP-PTS activity was and the more effectively xylitol decreased glucose : PEP-PTS activity, the more sensitive the strain was to xylitol. These results suggest that the following inhibitory mechanisms are active in the xylitol-sensitive mutans streptococci: direct inhibition of glycolytic enzymes by xylitol 5-phosphate derived from xylitol : PEP-PTS and, possibly, indirect inhibition through competition for the phosphoryl donor, HPr-P, between glucose and xylitol : PEP-PTSs.

Ontogeny of the antigen-reactive lymph follicle-forming capacity of the popliteal lymph node in neonatal mice

The ontogenetic development of the reactive lymph follicle-forming capacity of the popliteal lymph node was investigated immunohistochemically in young mice which had received a single injection of hemocyanin (KLH) in a rear footpad at a predetermined age (between 1 and 21 days). The mice were sacrificed at various intervals after injection. In non-stimulated young mice, primary lymph follicles first appeared in the popliteal node at 11 days of age. When KLH was given to 7-day-old or older mice, each draining popliteal node showed a marked increase in B lymphocytes in the extrafollicular zone 3 days after injection and produced a number of "new" lymph follicles outside the pre-existing follicles over the next few days. In mice injected at 2-4 days of age, these nodes showed an increase in B lymphocytes in the outer cortex and had produced several lymph follicles by 8 days of age. The number of lymph follicles produced by each node tended to increase in line with age at injection. These results indicate that neonatal popliteal nodes become able to produce lymph follicles in response to exogenous antigens some time before ontogenetically developing follicles appear. The formation of new lymph follicles observed in draining popliteal nodes after KLH injection at an early postnatal age is discussed in relation to the ontogenetic development of stromal cells (precursors of follicular dendritic cells) that are capable of interacting with B lymphocytes and the extent of B lymphocyte influx into the node induced by KLH stimulation.

p53 prevents maturation of T cell development to the immature CD4-CD8+ stage in Bcl11b-/- mice

Signaling pathways such as the pre-TCR and Wnt pathways regulate alpha/beta T cell differentiation in thymus. Mice lacking an essential component of the pre-TCR exhibit arrest at the (CD4(-)CD8(-)) (CD44(-)CD25(+)) stage (DN3) of thymocyte development, and introduction of p53 deficiency into those mice abrogates this arrest, resulting in transition to the (CD4(+)CD8(+)) double-positive (DP) stage. This paper examines the effect of inactivation of p53 on thymocyte development in Bcl11b(-/-) mice that exhibit arrest at the DN3 or (CD4(-)CD8(+)) immature single-positive (ISP) stage. No DP thymocytes were detected in thymocytes of adoptive transfer experiments in scid mice that were derived from p53(-/-)Bcl11b(-/-) precursors but ISP thymocytes increased in the proportion and in the cell number approximately three times higher than those from Bcl11b(-/-) precursors. Consistently, the level of apoptosis decreased to the level of wild-type precursors. These results suggest that inactivation of p53 is sufficient for DN3 thymocytes to differentiate into the ISP, but not to DP, stage of thymocyte development in Bcl11b(-/-) mice. This provides evidence for a novel p53-mediated checkpoint that regulates the transition from the DN3 to ISP stage of thymocyte development.

Cytological basis for enhancement of radiation-induced mortality by Friend leukaemia virus infection

PURPOSE

To analyse the cytological basis for enhancement of radiation-induced mortality by Friend leukaemia virus infection.

MATERIALS AND METHODS

Cellularity in haematopoietic tissues of C3H mice infected with FLV and/or whole-body irradiation was examined.

RESULTS

When mice were treated with a sublethal dose (3 Gy) of irradiation at 1 week after virus infection, most manifested a severe loss of cellularity in the spleen, bone marrow and peripheral blood 2 weeks after irradiation. More than 90% of the mice died within 1 month post-irradiation. However, this deleterious effect of virus infection on the survival of irradiated mice was observed only when they were irradiated at around 1 week after virus inoculation. Strain differences in the sensitivity to this effect were observed among virus-sensitive strains of mice.

CONCLUSIONS

The results indicate that Friend leukaemia virus infection can cause enhancement of radiation sensitivity of haematopoietic cells in host animals in a restricted manner in terms of genetic background and the interval between infection and irradiation.

Diagnosis and treatment of progressive space-occupying radiation necrosis following stereotactic radiosurgery for brain metastasis: value of proton magnetic resonance spectroscopy

BACKGROUND

There have been some reports that radiation necrosis can be controlled conservatively. There are rare cases showing progressive space-occupying radiation necrosis (PSORN). It is very difficult to control PSORN by conservative treatment. The purpose of this study was to evaluate the early diagnosis of those cases and the timing of surgery for patients with PSORN.

METHOD

We have experienced some cases where quality of life was improved by the removal of PSORN after stereotactic radiosurgery (SRS) for brain metastases. Therefore, we evaluated retrospectively the diagnosis and treatment of six cases of symptomatic PSORN at approximately 6-12 months after SRS for metastatic brain tumours.

FINDINGS

In all six cases, on Magnetic Resonance Imaging with Gd contrast material (Gd-MRI), PSORN was revealed as a ring-like enhanced mass with large perifocal oedema coupled with the appearance of neurological deficit. Proton Magnetic Resonance Spectroscopy ((1)H-MRS) enabled us to differentiate PSORN from recurrence of metastases in all six cases. Single Photon Emission Computed Tomography with thallium-201 chloride (201TlCl-SPECT) enabled us to do this in four cases of the six. In four cases of the six, lesionectomy of the ring-like enhanced mass (PSORN) was performed, and in two of these cases the removal was performed within 4 weeks from the time when conservative treatment became ineffective, and the neurological deficit and perifocal oedema was improved as was the quality of life. However, in the other two patients who were left for more than 16 weeks, the deficit was gradually progressive. The two patients who did not receive lesionectomy were treated by conservative means with steroids and/or heparin and warfarin and they had progressive neurological symptoms.

INTERPRETATION

Although, the number of patients is small in this study, and more data will be needed, it is recommended that lesionectomy is performed at an early stage, if possible, when conservative management has failed.

In vivo distribution of receptor for ecotropic murine leukemia virus and binding of envelope protein of Friend Murine leukemia virus

Ecotropic infection by Murine leukemia virus (MuLV) infection is initiated by the interaction between the receptor-binding domain of the viral surface glycoprotein (SU) and the cell-surface receptor, mCAT-1. To study the in vivo localization of viral binding site in mice, green fluorescence protein (GFP)-tagged Friend SU (F-SU/GFP) was incubated with tissue sections. Lymphohematopoietic organs and a part of the glandular tissues of C3H as well as C57BL/6 mice revealed positive signals for F-SU/GFP binding on the cell surface. In contrast, C4W mice, which is a partial congenic mouse strain carrying the Fv-4 (r) gene on a BALB/c genetic background, exhibited negative signals in most of the organs except for a very weak binding in the pancreas. The expression of mCAT-1 mRNA determined by reverse transcriptase (RT)-polymerase chain reaction (PCR) revealed a similar distribution in C3H, C57BL/6 and C4W mice. Most of the organs including lymphohematopoietic organs and glandular organs revealed significant expression of mRNA for mCAT-1 gene, while the liver, heart and muscle did not. The results from binding assay were consistent with the fact that Friend MuLV-induced pathogenesis was usually associated with lymphohematopoietic systems, although mRNA expression for mCAT-1 was rather ubiquitous. The discrepancy between F-SU/GFP binding and mRNA expression for mCAT-1 in lymphohematopoietic organs of C4W mice would support the receptor interference effect by the Fv-4 (r) gene causing the resistance of C4W mouse to Friend MuLV infection.

Cytogenetic and cellular events during radiation-induced thymic lymphomagenesis in the p53 heterozygous (+/-) B10 mouse

PURPOSE

Cellular and cytogenetic events in radiation-induced thymic lymphomagenesis were investigated in the p53 heterozygous (+/-) mouse following a single dose of whole-body irradiation.

MATERIALS AND METHODS

The loss of the wild-type p53 allele and microsatellite markers of chromosome 11 in thymic lymphomas that developed in the p53 heterozygous (+/-) mouse after irradiation, and the stage at which prelymphoma cells appeared were analysed.

RESULTS

The p53 heterozygous mouse developed thymic lymphomas in a dose-dependent manner. The loss of the wild-type p53 allele (loss of heterozygosity; LOH) occurred in almost all thymic lymphomas induced in the irradiated p53 heterozygous mouse. Cytogenetic analysis for the mechanism of LOH strongly suggested that the loss of the wild-type p53 gene in the lymphomas was caused by duplication of the disrupted allele through either homologous recombination or non-disjunctional chromosome duplication. The assay for prelymphoma cells suggested that a critical event in the development of prelymphoma cells occurred at least 3 weeks after irradiation.

CONCLUSIONS

The loss of the wild-type p53 gene in thymocytes of the p53 heterozygous mouse may precede the development of prelymphoma cells after irradiation and be a valuable marker of radiation-induced leukemogenesis.

The filamentous type III secretion translocon of enteropathogenic Escherichia coli

Enteropathogenic Escherichia coli (EPEC) uses a type III secretion system (TTSS) to inject effector proteins into the plasma membrane and cytosol of infected cells. To translocate proteins, EPEC, like Salmonella and Shigella, is believed to assemble a macromolecular complex (type III secreton) that spans both bacterial membranes and has a short needle-like projection. However, there is a special interest in studying the EPEC TTSS owing to the fact that one of the secreted proteins, EspA, is assembled into a unique filamentous structure also required for protein translocation. In this report we present electron micrographs of EspA filaments which reveal a regular segmented substructure. Recently we have shown that deletion of the putative structural needle protein, EscF, abolished protein secretion and formation of EspA filaments. Moreover, we demonstrated that EspA can bind directly to EscF, suggesting that EspA filaments are physically linked to the EPEC needle complex. In this paper we provide direct evidence for the association between an EPEC bacterial membrane needle complex and EspA filaments, defining a new class of filamentous TTSS.

A gene therapy model for retrovirus-induced disease with a viral env gene: expression-dependent resistance in immunosuppressed hosts

At the initial stage of retroviral infection, virion envelope glycoprotein (env product) binds to cell surface receptors. Cells infected with retrovirus or into which the env gene was introduced, become resistant to superinfection by other retroviruses with the same receptor specificity, a phenomenon known as receptor interference. We have demonstrated previously that the introduction of an env gene from a truncated endogenous ecotropic murine leukemia virus (MuLV), the Fv-4 resistance (Fv-4r) gene, into the bone marrow hematopoietic cells of Fv-4 sensitive (Fv-4s) mice protected mice from ecotropic retrovirus-induced disease. Using the gene transfer system under the control of the retroviral vector and bone marrow transplantation (BMT), here we could show that the expression of an introduced Fv-4r gene in hematopoietic cells continued for more than 1 year after BMT. To determine the inhibitory mechanism of Fv-4r env gene expression against FLV-infection in this model system, peripheral blood mononuclear cells (PBMCs), or spleen cells from chimeras with various degrees of env-expression, were mixed with green fluorescence protein (GFP)-conjugated Friend MuLV envglycoprotein (GFP-Fr-ENV). The amount of GFP-Fr-ENV bound to these cells inversely correlated with the expression intensity of the transduced env gene indicating the receptor interference effect. Next, to see whether transduction of the Fv-4r gene would protect an immunosuppressed host from FLV-induced leukemogenesis, we generated immunocompromised chimeras by transplanting env-transduced bone marrow cells into a thymectomized host. These chimeras also resisted FLV-induced leukemogenesis, indicating that receptor interference-based gene therapy could become a therapeutic basis for immunodeficiency virus-induced diseases in vivo.

Lipid peroxidation end products-responded induction of a preneoplastic marker enzyme glutathione S-transferase P-form (GST-P) in rat liver on admistration via the portal vein

The in vivo induction mechanism of a preneoplastic marker enzyme, glutathione S-transferase P-form (GST-P), by a number of carcinogens and some noncarcinogens such as anti-oxidants [Proc. Natl. Acad. Sci. U.S.A. 85 (1984) 3964] has remained to be solved. Among the various administration routes tested, GST-P became immunohistochemically demonstrable in the liver centrilobular zone 3 after 24-48h on administration of prostaglandin J2's, 15-deoxy-Delta(12,14)-PGJ2, PGJ2 and Delta(12)-PGJ2 to male rats via the portal vein, whereby the animals had been pretreated with Soya oil intraperitoneally to exhaust fatty acid binding proteins. Unsaturated aldehydes, 4-hydroxynonenal, crotonaldehyde and acrolein, given by the same route induced putatively preneoplastic single cells positive for GST-P. As these lipid peroxidation end products are the substrates as well as inducers of the enzyme, its physiological function could be their detoxication. These results indicate that GST-P expression can be mediated through lipid peroxidation possibly accounting for induction observed with a wide variety of carcinogens. In addition, present method may also be of use as a direct, simple, rapid, and sensitive in vivo test in examination of other biological responses.

Characterization of immortalized human chondrocytes originated from osteoarthritis cartilage

Immortalized cloned human chondrocytes isolated from a normal (Ch-4, 8, N) and an osteoarthritis patient (Ch-8-OA) were established by introduction of recombinant SV40-adenovirus vector containing SV40 early gene. These cells exhibited continuous proliferative capacity in monolayer culture and showed chondrocytic characteristics in that they were positive for alkaline phosphatase and collagen type II. When cells were treated with IL-1alpha, the growth was inhibited. IL-1alpha induced the production of IL-6, GM-CSF and TNFalpha from immortalized chondrocytes. Significantly high amounts of cytokines including IL-6, GM-CSF and TNFalpha were produced from Ch-8-OA cells, even in the absence of IL-1alpha stimulation. Interestingly, TNFalpha, exogenously added into the culture, inhibited the growth of Ch-8-OA cells. Further studies are required to clarify the different mechanisms on chondrocytes originating from osteoarthritis cartilage underlying the biological reaction to various cytokines and the production of these cytokines as compared with chondrocytes from normal cartilages. However, the novel chondrocyte cell lines established in the present study may provide researchers with a useful model for studying the pathogenesis of osteoarthritis.

Adenosarcoma of the uterine corpus associated with ovarian thecoma

We describe a case of adenosarcoma of the uterine corpus associated with ovarian thecoma in a 67-year-old woman. The patient underwent surgery under a diagnosis of ovarian carcinoma. The 110 x 70 mm-sized ovarian tumor was diagnosed as thecoma. The polypoid tumor of the uterine corpus which measured 30 x 15 mm was diagnosed as adenosarcoma. Cells of both epithelial and stromal elements of the adenosarcoma expressed estrogen receptors (determined by immunohistochemistry). These findings support the view that estrogen stimulation, including that by a pre-existing ovarian thecoma, may play a role in the development of mesenchymal and mixed epithelial / mesenchymal uterine tumors, including adenosarcoma.

Impairment in the expression and activity of Fyn during differentiation of naive CD4+ T cells into the Th2 subset

We previously showed that the amounts of Fyn protein in Th2 clones were approximately one-third to one-fifth of those in Th1 clones. In this study we examined the role of Fyn in the polarization of naive CD4+ T cells toward the Th2 subset using fyn(-/-) mice. The fyn(-/-) naive CD4+ T cells efficiently produced Th2 cytokines and polarized toward the Th2 subset even in the absence of IL-4 and IL-13. The expression of Fyn in wild-type CD4+ T cells decreased at a transcription level concomitant with polarization toward the Th2 subset. These results suggest that Fyn plays a role in the down-regulation of the differentiation of naive CD4+ T cells into the Th2 subset.

Establishment of left-right asymmetric innervation in the lancelet oral region

Lancelets (amphioxus) exhibit a remarkable asymmetric development in the anterior body region, which is reflected in the peripheral nervous system even at adulthood. Not all of the anterior nerves are involved, but the left third to fifth nerves are clearly asymmetric. To trace the developmental process responsible for asymmetric innervation, the peripheral nerves in the anterior region were studied in pre- and mid-metamorphic larvae, 1-cm-long juveniles, and in adults by using whole-mount immunostaining. The mouth changes in size and location during larval life before moving ventrally and, in conjunction with this change, nerves in the oral region are also modified. The left second nerve initially innervates the oral region, but this connection is secondarily lost. As the mouth expands and shifts posteriorly, the left fifth to ninth nerves join the left third and fourth in the innervation of the oral region. The left third to sixth nerves anastomose with the oral nerve ring, which encircles the mouth on the left side. In the juveniles and adults, there are two nerve plexuses that run parallel to the margin of the oral hood. The innermost of these, the "inner oral-hood nerve plexus", is asymmetrically connected with the left third to fifth nerves on both sides. The other, the "outer oral-hood nerve plexus", is ipsilaterally connected with the third to seventh nerves on both sides. The velar nerve ring is also innervated asymmetrically by the left fourth and fifth nerves. From these observations, we suggest that the oral nerve ring is the precursor of both the inner oral-hood nerve plexus and the velar nerve ring, and that the asymmetric innervation retained in adult lancelets is related to the early anastomosis of the left nerves with the oral nerve ring. We also show that, contrary to the persistent asymmetric innervation, the axonal patterns of the anterior peripheral nervous system in developing lancelets can change.

Collecting duct carcinoma with long survival treated by partial nephrectomy

A case is reported of collecting duct carcinoma of the left kidney treated with partial nephrectomy. A 57-year-old woman presented for evaluation of the left renal mass, which was detected by screening ultrasonography. A computed tomography scan and magnetic resonance imaging showed a solid mass at the upper pole of the left kidney. The renal tumor biopsy revealed a low-grade renal cell carcinoma or a tubulopapillary adenoma. Subsequently, left partial nephrectomy was performed. Microscopically, the tumor showed tubulopapillary proliferation with a fibrous capsule. Histochemically, the tumor cells reacted with lectins or antibodies against the collecting duct. Twenty-four months after partial nephrectomy, the patient is alive and has no distant metastatic lesions. We review the literature on collecting duct carcinoma, in addition to the case of partial nephrectomy.

Emx2directs the development of diencephalon in cooperation withOtx2

The vertebrate brain is among the most complex biological structures of which the organization remains unclear. Increasing numbers of studies have accumulated on the molecular basis of midbrain/hindbrain development, yet relatively little is known about forebrain organization. Nested expression among Otx and Emx genes has implicated their roles in rostral brain regionalization, but single mutant phenotypes of these genes have not provided sufficient information. In order to genetically determine the interaction between Emx and Otx genes in forebrain development, we have examined Emx2−/−Otx2+/− double mutants and Emx2 knock-in mutants into the Otx2 locus (Otx2+/Emx2). Emx2−/−Otx2+/− double mutants did not develop diencephalic structures such as ventral thalamus, dorsal thalamus/epithalamus and anterior pretectum. The defects were attributed to the loss of the Emx2-positive region at the three- to four-somite stage, when its expression occurs in the laterocaudal forebrain primordia. Ventral structures such as the hypothalamus, mammillary region and tegmentum developed normally. Moreover, dorsally the posterior pretectum and posterior commissure were also present in the double mutants. In contrast, Otx2+/Emx2 knock-in mutants displayed the majority of these diencephalic structures; however, the posterior pretectum and posterior commissure were specifically absent. Consequently, development of the dorsal and ventral thalamus and anterior pretectum requires cooperation between Emx2 and Otx2, whereas Emx2 expression is incompatible with development of the commissural region of the pretectum.

Complementary functions of Otx2 and Cripto in initial patterning of mouse epiblast

The development of the mammalian antero-posterior (A-P) axis is proposed to be established by distinct anterior and posterior signaling centers, anterior visceral endoderm and primitive streak, respectively. Knock-out studies in mice have shown that Otx2 and Cripto have crucial roles in the generation and/or functions of these anterior and posterior centers, respectively. In both Otx2 and Cripto single mutants, the initial formation of the A-P axis takes place in a proximal-distal (P-D) orientation, but subsequent axis rotation fails to occur. To examine the developmental consequences of the lack of these two genes, we have analyzed the Otx2(-/-);Cripto(-/-) double homozygous mutant phenotype. In the double mutants, the expression of the A-P axis markers Cer-l, Lim1, and Wnt3 was not induced, while expression of Fgf8 and T was expanded throughout the epiblast, indicating that the double mutants could not form the A-P axis even in its initial P-D orientation. In addition, the double mutants displayed defects in differentiation of the visceral endoderm overlying the epiblast, as well as in the extraembryonic ectoderm. Furthermore, differentiation of neuroectoderm was accelerated as judged by the reduction of Oct4 expression and emergence of Sox1 and Gbx2 expression in the double mutant epiblast. The resulting ectoderm only displayed characteristics of anterior hindbrain, implicating it as a ground state in the mammalian body plan. Our results indicate that complementary functions of Otx2 and Cripto are essential for initial patterning of the A-P axis in the mouse embryo.

Subcellular localization of insulin receptor substrate family proteins associated with phosphatidylinositol 3-kinase activity and alterations in lipolysis in primary mouse adipocytes from IRS-1 null mice

To clarify the roles of insulin receptor substrate (IRS) family proteins in phosphatidylinositol (PI) 3-kinase activation and insulin actions in adipocytes, we investigated the intracellular localization of IRS family proteins and PI 3-kinase activation in response to insulin by fractionation of mouse adipocytes from wild-type and IRS-1 null mice. In adipocytes from wild-type mice, tyrosine-phosphorylated IRS-1 and IRS-2, which were found to associate with PI 3-kinase in response to insulin, were detected in the plasma membrane (PM) and low-density microsome (LDM) fractions. By contrast, tyrosine-phosphorylated IRS-3 (pp60), which was found to associate with PI 3-kinase, was predominantly localized in the PM fraction. In adipocytes from IRS-1-null mice, insulin-stimulated PI 3-kinase activity in anti-phosphotyrosine (alphaPY) immunoprecipitates in the LDM fraction was almost exclusively mediated via IRS-2 and was reduced to 25%; however, insulin-stimulated PI 3-kinase activity in the PM fraction was primarily mediated via IRS-3 and was reduced to 60%. To determine the potential functional impact of the distinct subcellular localization of IRSs and associating PI 3-kinase activity on adipocyte-specific metabolic actions, we examined lipolysis in IRS-1 null mice. The level of isoproterenol-induced lipolysis was increased 5.1-fold in adipocytes from IRS-1 null mice as compared with wild-type mice. Moreover, hormone-sensitive lipase (HSL) protein was increased 4.3-fold in adipocytes from IRS-1-null mice compared with wild-type mice, and HSL mRNA expression was also increased. The antilipolytic effect of insulin in IRS-1 null adipocytes, however, was comparable to that in wild-type mice. Thus, discordance between these two insulin actions as well as the transcriptional and translational effect (HSL mRNA and protein regulation) and the PM effect (antilipolysis) of insulin may be explained by distinct roles of both PI 3-kinase activity associated with IRS-1/IRS-2 and PI 3-kinase activity associated with IRS-3 in insulin actions related to their subcellular localization.

Expression of receptor for ecotropic murine leukemia virus on hematopoietic cells

A fusion protein (F-SU/GFP) which is comprised of the surface (SU) subunit of the Friend MuLV envelope glycoprotein and the green fluorescence protein (GFP) was generated by a baculovirus expression system. The F-SU/GFP specifically bound to mammalian tissue cultured cells expressing the mCAT-1, the receptor for ecotropic murine leukemia virus (ECO-MuLV). The expression level of mCAT-1 on hematopoietic cells was measured based on the capacity of cells to absorb the F-SU/GFP. In BALB/c mice susceptible to Eco-MuLV infection, all hematopoietic cell subpopulations absorbed the F-SU/GFP with the most prominent absorption observed in the TER119+ erythroblasts. Hematopoietic cells from C4W and AKR mice did not absorb the F-SU/GFP as readily as the BALB/c cells, probably due to expression of the envelope glycoproteins of endogenous Eco-MuLVs in these mice. Although AKR mice are susceptible to Eco-MuLV infection while C4W mice are resistant, these mice showed no apparent difference in the F-SU/GFP-absorbing capacity.

Functional disorders of the sympathetic nervous system in mice lacking the alpha 1B subunit (Cav 2.2) of N-type calcium channels

N-type voltage-dependent Ca(2+) channels (VDCCs), predominantly localized in the nervous system, have been considered to play an essential role in a variety of neuronal functions, including neurotransmitter release at sympathetic nerve terminals. As a direct approach to elucidating the physiological significance of N-type VDCCs, we have generated mice genetically deficient in the alpha(1B) subunit (Ca(v) 2.2). The alpha(1B)-deficient null mice, surprisingly, have a normal life span and are free from apparent behavioral defects. A complete and selective elimination of N-type currents, sensitive to omega-conotoxin GVIA, was observed without significant changes in the activity of other VDCC types in neuronal preparations of mutant mice. The baroreflex response, mediated by the sympathetic nervous system, was markedly reduced after bilateral carotid occlusion. In isolated left atria prepared from N-type-deficient mice, the positive inotropic responses to electrical sympathetic neuronal stimulation were dramatically decreased compared with those of normal mice. In contrast, parasympathetic nervous activity in the mutant mice was nearly identical to that of wild-type mice. Interestingly, the mutant mice showed sustained elevation of heart rate and blood pressure. These results provide direct evidence that N-type VDCCs are indispensable for the function of the sympathetic nervous system in circulatory regulation and indicate that N-type VDCC-deficient mice will be a useful model for studying disorders attributable to sympathetic nerve dysfunction.

Isolation of Dlx and Emx gene cognates in an agnathan species, Lampetra japonica, and their expression patterns during embryonic and larval development: conserved and diversified regulatory patterns of homeobox genes in vertebrate head evolution

Agnathan cognates of vertebrate homeobox genes, Emx and Dlx, were isolated from embryonic cDNA of a Japanese marine lamprey, Lampetra japonica. Analyses of amino acid sequences indicated that the Dlx cognate was closely related to the common ancestor of gnathostome Dlx1 and Dlx6 groups and termed LjDlx1/6. Southern blot analyses could not rule out the possibility that L. japonica possesses more than one paralog for both LjDlx1/6 and LjEmx, the lamprey cognate of Emx. Expression of LjDlx1/6 was regulated spatially as well as developmentally, and its transcripts were mainly found in the craniofacial and pharyngeal mesenchyme and in the forebrain. The expression pattern of LjEmx changed dramatically during embryogenesis; expression was seen initially in the entire neural tube and mesoderm, which were secondarily downregulated, and secondarily in cranial nerve ganglia and in the craniofacial mesenchyme. No specific expression of LjEmx was seen in the telencephalon. Comparisons of Dlx and Otx gene expression patterns suggested a shared neuromeric pattern of the vertebrate brain. Absence of Emx expression implied that the patterning of the lamprey telencephalon is not based on the tripartite plan that has been presumed in gnathostomes. Expression domains of LjDlx1/6 in the upper lip and of LjEmx in the craniofacial mesenchyme were peculiar features that have not been known in gnathostomes. Such differences in expression pattern may underlie distinct morphogenetic pathway of the mandibular arch between the agnathans and gnathostomes.

Patterns of age-dependent changes in the numbers of lymph follicles and germinal centres in somatic and mesenteric lymph nodes in growing C57Bl/6 mice

The timing of the first appearance of lymph follicles and germinal centres in various lymph nodes, and the ways in which numbers of these and IgM-synthesising cells increase within the nodes, were investigated in male and female C57Bl/6N mice aged from 4 d to 16 wk. The lymphoid organs examined were the Peyer's patches, spleen, somatic (submandibular, deep cervical, brachial, axillary, inguinal and popliteal) and visceral (mesenteric and lumbar) lymph nodes. Primary follicles appeared in most somatic lymph nodes 6 d after birth. The number of follicles per node then increased rather sharply in larger lymph nodes and slowly in smaller nodes, up to 28 d of age, reaching a level which varied according to the location of the node. Thereafter, the number of follicles in the somatic lymph nodes increased only slightly to moderately, reaching a peak or plateau at 8-12 wk. In the mesenteric (ileocaecal) nodes, primary follicles first appeared at 12 d, then increased linearly during the suckling period and after weaning to reach a plateau at 8 wk of age. Germinal centres appeared in the submandibular and mesenteric nodes at 28 d and their numbers increased consistently in the latter, while remaining low in the former. The impact of possible 'natural' exogenous antigen stimulation of the various lymph nodes was estimated from the presence of IgM-synthesising cells and germinal centres. Differences between the patterns of age-dependent changes in the numbers of lymph follicles observed in the somatic and mesenteric lymph nodes during their ontogeny are discussed in relation to differences in the magnitude of the exogenous antigen stimulatory effect. We also found that the variations in the numbers of lymph follicles produced in somatic lymph nodes at different locations during the first 28 d after birth reflected differences in the dimensions of the body regions drained by a particular somatic lymph node at this stage of development.

Establishment of an androgen-responsive prostatic cell line "PEA5" from a p53-deficient mouse

BACKGROUND

We demonstrated that p53-deficiency is sufficient for the establishment of clonal cell lines from the uterus and prostate. In the present study, we improved cloning methods to establish androgen-responsive cell lines.

METHODS

In our previous study, a prostatic cell line was established from the ventral prostate of a p53-deficient mouse and was maintained in a medium containing heat-inactivated fetal calf serum at 10% supplemented with insulin (10 microg/ml), transferrin (10 microg/ml), cholera toxin (10 ng/ml) and selenium (10(-8) M). In the present study, 5alpha-dihydrotestosterone (10(-8) M) was added to the medium from the beginning of cloning procedures.

RESULTS

We succeeded in the establishment of an androgen receptor positive prostatic cell line, designated PEA5. PEA5 cells exhibited a typical epithelial morphology in culture and growth was stimulated by androgens in a dose-dependent manner. In addition, they grew and formed three-dimensional structures in collagen gel, in which growth was also stimulated by androgen.

CONCLUSIONS

Although PEA5 lacks p53 gene, it still retains androgen sensitivity. In collagen gel culture, PEA5 cells can grow and form three-dimensional structures similar to those of the primary cultures reported previously. Furthermore, prostates of p53-deficient mice are shown to be useful sources for obtaining androgen-responsive cells lines.

Role of lymphoid cells in age-related change of susceptibility to Friend leukemia virus-induced leukemia

Susceptibility for Friend leukemia virus (FLV)-induced leukemogenesis was examined in the C3H/He (C3H)-->C57BL/6 (B6) radiation bone marrow chimeras of various age groups, and the effect of aging of host mice on the susceptibility was determined. The bone marrow chimera system provided the various age of FLV-resistant host mice (B6) possessing the same age of FLV-susceptible target cells from C3H mice. Using this system, we could determine the aging effect on the host resistancy against FLV without an influence of the aging effect on target cells. First, the young C3H-->young B6 chimeras and young C3H-->old B6 chimeras were compared. The young-->old chimeras were more susceptible to FLV-induced acute disease than the young-->young chimeras. The spleen CD4+ as well as CD8+ T cells were reduced in young-->old chimeras compared with young-->young chimeras. Similarly, the old C3H-->old B6 chimeras were more susceptible than old-->young chimeras and revealed the lower CD4+ T cell ratio in the spleen. Discussion was made on the possible implication of these findings on the role of T cells in age-related change of resistance to FLV-induced leukemogenesis.

Setting characteristics of five autopolymerizing resins measured by an oscillating rheometer

STATEMENT OF PROBLEM

Ease of handling and the working time of autopolymerizing resins are directly associated with the setting characteristics during polymerization.

PURPOSE

This study assessed the setting characteristics of autopolymerizing resins by measuring viscosity changes and tested the hypotheses that: (1) different products have different viscosity increase patterns during polymerization, and (2) the increased rate of viscosity is not proportional to the length of the setting time.

MATERIAL AND METHODS

Viscosity change during polymerization was measured in 5 test materials (Unifast II, ADFA, META FAST, Miky, and Trim) with an oscillating rheometer. The working time was defined as the time required for a 5% reduction in the amplitude of the rheometer trace. The setting time was measured as the time required to reach zero amplitude on the rheometer trace.

RESULTS

The order of working times from longest to shortest was Trim, Unifast II and META FAST, ADFA, Miky (ANOVA, P<.0001). The order of setting times from longest to shortest was Trim, META FAST, Miky, ADFA, Unifast II. Materials that had rapid setting times did not necessarily have short working times. Unifast II showed well-balanced setting properties that satisfied both longer working time and faster setting time.

CONCLUSION

Autopolymerizing resins have setting characteristics specific to the brand. Knowledge of these characteristics is essential for selection of the appropriate resin product depending on the purpose of clinical usage and the individual dentist's technique.

Kinetic effect of zinc(II) and cadmium(II) ions on configurational inversion of deltaLLL-fac(S)-tris(L-cysteinato-N,S)cobalt(III) complex

It has been confirmed from circular dichroism (CD) spectral changes of aqueous solutions of deltaLLL-fac(S)-[Co(L-cys-N,S)3]3- that the absolute configurational inversion to the ALLL isomer is remarkably accelerated by zinc(II), while it is retarded by cadmium(II). In the diluted solutions of these metal ions containing excess deltaLLL-fac(S)-[Co(L-cys-N,S)3]3-, the observed inversion rate constant linearly depends on the zinc(II) concentration with an intercept, while it is not affected by the cadmium(II) concentration. The kinetic behavior has been explained by difference between zinc(II)- and cadmium(II)-interactions with lone pairs on sulfur donor atoms of fac(S)-[Co(L-cys-N,S)3]3-. It has also been proposed that concentrations of zinc(II) and cadmium(II) can be simultaneously determined by the kinetic measurements.

Practical protective tools for occupational exposure: 1) double focus spectacles for the aged with highly refracted glass lens 2) remodeled barrier for radiation protection

SUMMARY

Two practical protective tools for occupational exposure for neurointerventional radiologists are presented. The first purpose of this study was to investigate the effectiveness of double focus spectacles for the aged with a highly refracted glass lens (special spectacles for the aged) for radiation protection of the crystalline lens of the eye in comparison with other spectacles on the market, based on the measurement of film density which was obtained by exposure of X-ray through those spectacles. As a result of the film densitometry mentioned above, the effectiveness of special spectacles for the aged in radiation protection was nearly equal to the effectiveness of a goggle type shield which is made with a 0.07 mm lead-equivalent plastic lens. The second purpose of this study was to investigate the effectiveness of the protective barrier, which we remodeled for cerebral angiography or neuroendovascular therapy, for radiation exposure, based on the measurement in a simulated study with a head phantom, and on the measurement of radiation exposure in operaters during procedures of clinical cases. In the experimental study radiation exposure in supposed position of the crystalline lens was reduced to about one third and radiation exposure in supposed position of the gonadal glands was reduced to about one seventh, compared to radiation exposure without employing the barrier. The radiation exposure was monitored at the left breast of three radiologists, in 215 cases of cerebral angiography. Employing the barrier in cerebral angiography, average equivalent dose at the left breast measured 1.49mu Sv during 10 min of fluoroscopy. In three kinds of neuroendovascular therapy in 40 cases, radiation exposure in an operator was monitored in the same fashion and the dose was recorded less than the result reported in previous papers in which any protective barrier have not been employed in the procedure (1,2). As a result, the two above mentioned protective tools are considered practical in clinical usage and very effective to reduce radiation exposure in an operator of interventional neuroradiolgy which may sometimes require many hours to complete the therapy under extended fluoroscopic time. 1) The first topic of this report is double focus spectacles for the aged with a highly refracted glass lens (special spectacles for the aged).

Disruption of insulin receptor substrate 2 causes type 2 diabetes because of liver insulin resistance and lack of compensatory beta-cell hyperplasia

To investigate the role of insulin receptor substrate (IRS)-2 in vivo, we generated IRS-2-deficient mice by gene targeting. Although homozygous IRS-2-deficient mice (IRS-2-/- mice) had a body weight similar to wild-type mice, they progressively developed type 2 diabetes at 10 weeks. IRS-2-/- mice showed insulin resistance and a defect in the insulin-stimulated signaling pathway in liver but not in skeletal muscle. Despite insulin resistance, the amount of beta-cells was reduced to 83% of that in wild-type mice, which was in marked contrast to the 85% increase in the amount of beta-cells in IRS-1-deficient mice (IRS-1-/- mice) to compensate for insulin resistance. Thus, IRS-2 plays a crucial role in the regulation of beta-cell mass. On the other hand, insulin secretion by the same number of cells in response to glucose measured ex vivo was significantly increased in IRS-2-/- mice compared with wild-type mice but was decreased in IRS-1-/- mice. These results suggest that IRS-1 and IRS-2 may play different roles in the regulation of beta-cell mass and the function of individual beta-cells.

A new murine zinc finger gene, Opr

Here we report a novel murine zinc-finger gene, Opr, belonging to the opa/Zic family. Opr is expressed in the entire embryonic ectoderm before gastrulation, but gradually restricted to the anterior part from the mid to late streak stage. At the beginning of neural induction, Opr is expressed throughout the anterior neural plate, but is soon restricted to the neural ridge. After neural tube closure, its expression is maintained in the dorsal part of the neural tube, except for the roof of the telencephalon. Opr is also expressed in somites and limbs.

Nephrotic syndrome associated with diffuse mesangial hypercellularity: is it a heterogeneous disease entity?

Diffuse mesangial hypercellularity (DMH) is a rare primary mesangial proliferative glomerulonephritis associated with idiopathic nephrotic syndrome (INS). We conducted this study on 15 patients, including 5 patients with repeated specimens, with a follow-up of 0.9-17.5 years and evaluated the clinical course and pathological findings. Seven patients were male. Ten patients were under 14 years of age. All specimens had INS and were diagnosed morphologically with primary diffuse mesangial proliferative glomerulonephritis at initial biopsy; 4 were diagnosed with focal segmental glomerulosclerosis (FSGS) within 3 years by the second biopsy. The remaining 11 patients included 8 initial responders and 3 initial nonresponders to 8 weeks' steroid therapy and had the histologic variant of the minimal-change nephrotic syndrome (MCNS). Ten of the 11 patients had normal renal function during the investigation period. One patient with the MCNS variant who was refractory to steroid therapy developed end-stage renal disease (ESRD) within 6 years. Four patient with the histologic variant of FSGS included 1 initial responder, 2 late responders, and 1 steroid-refractory case. One patient with the FSGS variant developed ESRD within 4 years. The follow-up biopsies documented that the severity of mesangial hypercellularity was associated with the severity of proteinuria or hematuria. We conclude that DMH may be divided into heterogeneous disease entities, whereas morphologic changes in initial biopsies were similar. Each variant as well as the degree of DMH should be recognized routinely by follow-up biopsy, because they are prognostic indicators.

Noninvasive, microinvasive, and invasive mucinous carcinomas of the ovary: a clinicopathologic analysis of 40 cases

BACKGROUND

Whether ovarian mucinous tumors with epithelial stratification of more than three cell layers in the absence of stromal invasion (i.e., carcinomas diagnosed according to the Hart and Norris criteria) should be placed in the same category as mucinous tumors with stromal invasion (i.e., unquestionable carcinomas) remains controversial. Because individual mucinous tumors frequently contain benign, borderline, and malignant components, the adequacy of sampling has been emphasized.

METHODS

We examined 21 mucinous carcinomas with no destructive stromal invasion (MCNI), 4 mucinous carcinomas with microinvasion (MCMI) of < 2 mm, and 15 mucinous carcinomas with invasion (MCI) of > or = 2 mm. Tumors were diagnosed as MCNI according to Hart and Norris criteria (12 tumors) or when severe nuclear atypia was present (9 tumors). Cases of MCNI were selected for review if a section had been taken for each 2 cm or less of the tumor's greatest diameter. The International Federation of Gynecology and Obstetrics stage and follow-up data of each case were examined, and differences among MCNI, MCMI, and MCI were analyzed.

RESULTS

All 21 patients with MCNI and all 4 patients with MCMI had Stage I disease; there was no recurrence or death in these cases. In contrast, 7 of 15 patients with MCI had Stage II or III disease, and 8 patients died.

CONCLUSION

MCNI clearly should be distinguished from MCI and be classified as noninvasive carcinomas after the absence of destructive stromal invasion has been confirmed by examining a sufficient number of sections.