Low-Intensity Pulsed Ultrasound Promotes Repair of 4-Vinylcyclohexene Diepoxide-Induced Premature Ovarian Insufficiency in SD Rats.

Women with premature ovarian insufficiency (POI) may be more vulnerable to a variety of health risks. To seek a new method to treat the disease, the effects of low-intensity pulsed ultrasound (LIPUS) on promoting repair of ovarian injury in female SD rats induced by 4-vinylcyclohexene diepoxide (VCD) were explored in this research. A total of 24 female SD rats were subjected to intraperitoneal injection of VCD to induce POI. Successful modeling was achieved in 22 rats, which were then randomized into VCD + LIPUS group (n = 13) and VCD group (n = 9). The control group (n = 5) was injected with equal normal saline. Hematoxylin and eosin staining, enzyme-linked immunosorbent assay, Western blot analysis, scanning electron microscope, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated nick end labeling assay were applied to detect the results. The results indicated that rats in the VCD group showed disorder in the estrous cycle, the number of atresia follicles and apoptosis granulosa cells increased (p < .05). After the LIPUS treatment, the estrous cycle recovered, the number of follicles increased (p < .05), the level of E2 and anti-Müllerian hormone enhanced (p < .05), and the follicle-stimulating hormone decreased (p < .05). The expression of NF-κB p65, TNFα, Bax, ATF4, and caspase-3 in ovarian tissue was significantly decreased (p < .05). These findings showed that LIPUS could promote the repair of the VCD-induced ovarian damage in SD rats, which has the potential to be further applied in the clinic.

3-Ethenylpyridine Measured in Urine of Active and Passive Smokers: A Promising Biomarker and Toxicological Implications.

In studies of tobacco toxicology, including comparisons of different tobacco products and exposure to secondhand or thirdhand smoke, exposure assessment using biomarkers is often useful. Some studies have indicated that most of the toxicity of tobacco smoke is due to gas-phase compounds. 3-Ethenylpyridine (3-EP) is a major nicotine pyrolysis product occurring in the gas phase of tobacco smoke. It has been used extensively as an environmental tracer for tobacco smoke. 3-EP would be expected to be a useful tobacco smoke biomarker as well, but nothing has been published about its metabolism and excretion in humans. In this Article we describe a solid-phase microextraction (SPME) GC-MS/MS method for determination of 3-EP in human urine and its application to the determination of 3-EP in the urine of smokers and people exposed to secondhand smoke. We conclude that 3-EP is a promising biomarker that could be useful in studies of tobacco smoke exposure and toxicology. We also point out the paucity of data on 3-EP toxicity and suggest that additional studies are needed.

Plasma Membrane Affiliated AMPA GluA1 in Estrogen Receptor ß-containing Paraventricular Hypothalamic Neurons Increases Following Hypertension in a Mouse Model of Post-menopause.

Sex and ovarian function contribute to hypertension susceptibility, however, the mechanisms are not well understood. Prior studies show that estrogens and neurogenic factors, including hypothalamic glutamatergic NMDA receptor plasticity, play significant roles in rodent hypertension. Here, we investigated the role of sex and ovarian failure on AMPA receptor plasticity in estrogen-sensitive paraventricular nucleus (PVN) neurons in naïve and angiotensin II (AngII) infused male and female mice and female mice at early and late stages of accelerated ovarian failure (AOF). High-resolution electron microscopy was used to assess the subcellular distribution of AMPA GluA1 in age-matched male and female estrogen receptor beta (ERß) enhanced green fluorescent protein (EGFP) reporter mice as well as female ERß-EGFP mice treated with 4-vinylcyclohexene diepoxide. In the absence of AngII, female mice at a late stage of AOF displayed higher levels of GluA1 on the plasma membrane, indicative of functional protein, in ERß-expressing PVN dendrites when compared to male, naïve female and early stage AOF mice. Following slow-pressor AngII infusion, males, as well as early and late stage AOF females had elevated blood pressure. Significantly, only late stage-AOF female mice infused with AngII had an increase in GluA1 near the plasma membrane in dendrites of ERß-expressing PVN neurons. In contrast, prior studies reported that plasmalemmal NMDA GluN1 increased in ERß-expressing PVN dendrites in males and early, but not late stage AOF females. Together, these findings reveal that early and late stage AOF female mice display unique molecular signatures of long-lasting synaptic strength prior to, and following hypertension.

Tissue reaction after subcutaneous implants of a new material composed of ethylene-vinyl acetate and starch for future use as a biomaterial.

This study aimed to evaluate the tissue reaction of ethylene-vinyl acetate (EVA) in 4 different compositions and processing: EVA foamed at high pressure with ultrasound (EVACU); EVA with 15% starch foamed at high pressure with ultrasound (EVAMCU); EVA with 15% starch foamed at high pressure without ultrasound and EVA foamed at high pressure without ultrasound as future use as a porous scaffold. Scanning electron microscopy images showed the influence of starch, reducing the diameter of pores. The number of open pores was also reduced with the addition of starch. The ultrasound applied during the manufacturing of composites does not affect these characteristics. Eighteen rats were used to test the tissue reaction of materials and PTFE (polytetrafluoroethylene), proven biocompatible material. After 7, 15, and 60 days of surgery, the materials were removed and processed for microscopic evaluation and counting of the inflammatory infiltrate. The data shows inflammatory reaction similar to PTFE. However, in the quantitative analysis at 60 days, the EVACU and EVAMCU showed less quantity of mononuclear cells (p < 0.05). Thus, the results suggest that the use of ultrasound in the production method (EVA) seems to have improved cell behavior regarding the reduction of infiltration over the period, with tissue response equivalent to the PTFE. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 400-407, 2019.

Adverse outcome pathways: opportunities, limitations and open questions.

Adverse outcome pathways (AOPs) are a recent toxicological construct that connects, in a formalized, transparent and quality-controlled way, mechanistic information to apical endpoints for regulatory purposes. AOP links a molecular initiating event (MIE) to the adverse outcome (AO) via key events (KE), in a way specified by key event relationships (KER). Although this approach to formalize mechanistic toxicological information only started in 2010, over 200 AOPs have already been established. At this stage, new requirements arise, such as the need for harmonization and re-assessment, for continuous updating, as well as for alerting about pitfalls, misuses and limits of applicability. In this review, the history of the AOP concept and its most prominent strengths are discussed, including the advantages of a formalized approach, the systematic collection of weight of evidence, the linkage of mechanisms to apical end points, the examination of the plausibility of epidemiological data, the identification of critical knowledge gaps and the design of mechanistic test methods. To prepare the ground for a broadened and appropriate use of AOPs, some widespread misconceptions are explained. Moreover, potential weaknesses and shortcomings of the current AOP rule set are addressed (1) to facilitate the discussion on its further evolution and (2) to better define appropriate vs. less suitable application areas. Exemplary toxicological studies are presented to discuss the linearity assumptions of AOP, the management of event modifiers and compensatory mechanisms, and whether a separation of toxicodynamics from toxicokinetics including metabolism is possible in the framework of pathway plasticity. Suggestions on how to compromise between different needs of AOP stakeholders have been added. A clear definition of open questions and limitations is provided to encourage further progress in the field.

Tunable, Injectable Hydrogels Based on Peptide-Cross-Linked, Cyclized Polymer Nanoparticles for Neural Progenitor Cell Delivery.

A PEG-based cyclized vinyl polymer was synthesized via one-step RAFT polymerization and used as a precursor of injectable hydrogels. Dithiol linkers including laminin-derived peptides containing IKVAV and YIGSR sequences and DTT were used for gelation. Fast and adjustable gelation rate was achieved through nucleophile-initiated thiol-Michael reaction under physiological conditions. Low swelling ratio and moderate degradation rate of the formed hydrogels were observed. 3D encapsulation of neural progenitor cells in the synthetic hydrogel showed good cell viability over 8 days. The long-term cell survival and proliferation were promoted by the introduction of laminin-derived peptides. This hydrogel platform based on peptide-cross-linked, cyclized vinyl polymers can be used as a universal hydrogel template for 3D cell encapsulation.

Glucose homeostasis in rats treated with 4-vinylcyclohexene diepoxide is not worsened by dexamethasone treatment.

4-vinilcyclohexene diepoxide (4-VCD) causes premature ovarian failure and may result in estrogen deficiency, characterizing the transition to estropause in rodents (equivalent to menopause in women). Estropause/menopause is associated with metabolic derangements such as glucose intolerance and insulin resistance. Glucocorticoids (GCs) are known to exert diabetogenic effects. Thus, we aimed to investigate whether rats with premature ovarian failure are more prone to the diabetogenic effects of GC. For this, immature female rats received daily injections of 4-VCD [160mg/kg body weight (b.w.), intraperitoneally (i.p.)] for 15 consecutive days, whereas control rats received vehicle. After 168days of the completion of 4-VCD administration, rats were divided into 4 groups: CTL-received daily injections of saline (1mL/kg, b.w., i.p.) for 5days; DEX-received daily injections of dexamethasone (1mg/kg, b.w., i.p.) for 5days; VCD-treated as CTL group; VCD+DEX-treated as DEX group. Experiments and euthanasia occurred one day after the last dexamethasone injection. 4-VCD-treated rats exhibited ovary hypotrophy and reduced number of preantral follicles (p<0.05). Premature ovarian failure had no impact on the body weight gain or food intake, but both were reduced by the effects of dexamethasone. The increase in blood glucose, plasma insulin and triacylglycerol levels as well as the reduction in insulin sensitivity caused by dexamethasone treatment was not exacerbated in the VCD+DEX group of rats. Premature ovarian failure did change neither the hepatic content of glycogen and triacylglycerol nor the glycerol release from perigonadal adipose tissue. Glucose intolerance was observed in the VCD group after an ipGTT (p<0.05), but not after an oral glucose challenge. Glucose intolerance and compensatory pancreatic ß-cell mass caused by GC were not modified by ovarian failure in the VCD+DEX group. We conclude that reduced ovarian function has no major implications on the diabetogenic effects promoted by GC treatment, indicating that other factors related to aging may make rats more vulnerable to GC side effects on glucose metabolism.

Preventive effect of American ginseng against premature ovarian failure in a rat model.

Preclinical Research Premature ovarian failure (POF) is defined by the WHO as the loss of physiological ovarian function before the age of 40. The effect of American ginseng and its underlying mechanisms in preventing and treating premature ovarian failure (POF) was studied in female Sprague-Dawley rats where POF was induced by ip administration of 4-vinylcyclohexene diepoxide (VCD). Rat behavior, serum hormone levels, ovarian and uterine size, pathological features, and ovarian tissue expression of genes associated with POF were assessed in controls, untreated POF model rats, and POF model rats treated with low- (1.125 g/kg), medium- (2.25 g/kg), and high-dose (4.5 g/kg) American ginseng. Compared with untreated POF model rats, those treated with medium- and high-dose American ginseng had more stable behavior and better coat appearance as well as serum hormone levels closer to those in control rats. Moreover, treatment with medium- or high-dose American ginseng increased ovarian and uterine size. Hematoxylin and eosin-staining revealed mature follicles and endometrium with an alternating concave/convex surface structure with visible capillaries and glands in ginseng- treated POF rats. PLA2G4A expression was positively correlated with POF, while the expression levels of PAPPA, STC2, CCL2, and NELL1 were negatively correlated with POF. Our study showed that American ginseng may effectively prevent POF and alleviate POF symptoms by regulating serum hormone levels and altering the expression levels of genes related to POF in ovarian tissue.

[Index contaminants and target organs]. / Inquinanti indice e organi bersaglio.

SENTIERI Project evaluates the health impact of environmental exposures on residential population of National Priority Contaminated Sites (NPCSs). It takes into account a priori etiological hypotheses, based on the epidemiological evidence of an association between those exposures and selected diseases or causes of death. Building on the previous chapter, this one acts as a blueprint for future causal inferences based on scientific evidence relating to the health effects of exposure to specific pollutants present in the sites. In order to select the relevant pollutants, we make use of data concerning soil, aquifers, the food chain and the atmosphere. For each pollutant, we indicate cancer site and target organs, for non-neoplastic diseases, based on scientific assessment by international Agencies. We have chosen to focus on two sites: Brescia-Caffaro and Priolo. This method may conceivably be used by SENTIERI in the future to carry out more specific studies and provides the basis for a systematic analysis of contaminated sites.

Caracterización del ambiente físico en viviendas Petrocasas en el Asentamiento Simón Bolívar de Cienfuegos 2008-2009 / Characterization of the physical environment in petrohouses from the village of Simón Bolívar in the province of Cienfuegos 2008-2009

En varios asentamientos del país se han construido viviendas Petrocasas de policloruro de vinilo, relleno con hormigón sobre balsa y cubierta de lámina de aluminio revestida de papel asfalto por ambas caras. El policloruro de vinilo como material de construcción resulta controversial en relación a sus efectos en la salud. Con el objetivo de caracterizar desde el punto de vista sanitario el ambiente físico en viviendas Petrocasas de Cienfuegos, fue conducido un estudio descriptivo en dos semanas seleccionadas de las estaciones seca y húmeda de 2008 y 2009. Se monitoreó factores de riesgo físico en una muestra de 6 viviendas seleccionadas según la opinión de expertos, del total de las 104 viviendas del asentamiento según su ubicación en las filas de viviendas: centro, culata de fila y fachada. Se estudió el ruido, componente magnético del campo electromagnético de baja frecuencia, iluminación natural, artificial, microclima y penetración del viento. La evaluación del monitoreo se efectuó por descriptores estadísticos, modelos de regresión, varianza y espectro de potencia bivariado con los paquetes estadísticos: SPSS v. 17,0 y Statistica v. 8,0. Durante la estación seca, la temperatura del aire es mayor en la habitación principal de viviendas con fachada al sur. En ambas estaciones, las temperaturas y humedades relativas de las viviendas son más altas que en la intemperie. Las cubiertas y paredes muestran calentamientos ante el asoleamiento. Los coeficientes de iluminación natural presentan elevadas reflexiones. Los valores del campo electromagnético son bajos. En la estación seca los niveles sonoros reflejan una contaminación acústica moderada. Concluimos que el microclima en el interior de las viviendas durante el día es inconfortable(AU)

Petrohouses have been built in several villages in the country. These houses are made of polyvinyl chloride, filled with raft concrete and covered with aluminum sheets coated with asphalt paper on both sides. The health effects of polyvinyl chloride as a construction material is a matter of controversy. With the purpose of carrying out a health characterization of the physical environment in Cienfuegos petrohouses, a descriptive study was conducted during two weeks selected from the dry and wet seasons of 2008 and 2009. Physical risk factors were monitored in a sample of 6 houses selected on the basis of expert opinion, of the total 104 houses in the village, according to their location in the rows: front, mid and end positions. The variables studied were noise, magnetic component of the low frequency electromagnetic field, natural and artificial lighting, microclimate and wind penetration. Monitoring was evaluated with statistical descriptors, regression models, variance and bivariate power spectrum, with the statistical software SPSS v. 17.0 and Statistica v. 8.0. In the dry season, air temperature is higher in the main room of houses with facades facing the south. In both seasons, temperature and relative humidity values are higher inside the houses than outside. Covers and walls heat up when hit by the sun. Natural lighting coefficients show high reflection values. Electromagnetic field values are low. In the dry season, sound levels show moderate acoustic contamination. It is concluded that the microclimate inside houses during the day is uncomfortable(AU)

Caracterización del ambiente físico en viviendas Petrocasas en el Asentamiento Simón Bolívar de Cienfuegos (2008-2009) / Characterization of the physical environment in petrohouses from the village of Simón Bolívar in the province of Cienfuegos (2008-2009)

En varios asentamientos del país se han construido viviendas Petrocasas de policloruro de vinilo, relleno con hormigón sobre balsa y cubierta de lámina de aluminio revestida de papel asfalto por ambas caras. El policloruro de vinilo como material de construcción resulta controversial en relación a sus efectos en la salud. Con el objetivo de caracterizar desde el punto de vista sanitario el ambiente físico en viviendas Petrocasas de Cienfuegos, fue conducido un estudio descriptivo en dos semanas seleccionadas de las estaciones seca y húmeda de 2008 y 2009. Se monitoreó factores de riesgo físico en una muestra de 6 viviendas seleccionadas según la opinión de expertos, del total de las 104 viviendas del asentamiento según su ubicación en las filas de viviendas: centro, culata de fila y fachada. Se estudió el ruido, componente magnético del campo electromagnético de baja frecuencia, iluminación natural, artificial, microclima y penetración del viento. La evaluación del monitoreo se efectuó por descriptores estadísticos, modelos de regresión, varianza y espectro de potencia bivariado con los paquetes estadísticos: SPSS v. 17,0 y Statistica v. 8,0. Durante la estación seca, la temperatura del aire es mayor en la habitación principal de viviendas con fachada al sur. En ambas estaciones, las temperaturas y humedades relativas de las viviendas son más altas que en la intemperie. Las cubiertas y paredes muestran calentamientos ante el asoleamiento. Los coeficientes de iluminación natural presentan elevadas reflexiones. Los valores del campo electromagnético son bajos. En la estación seca los niveles sonoros reflejan una contaminación acústica moderada. Concluimos que el microclima en el interior de las viviendas durante el día es inconfortable(AU)

Petrohouses have been built in several villages in the country. These houses are made of polyvinyl chloride, filled with raft concrete and covered with aluminum sheets coated with asphalt paper on both sides. The health effects of polyvinyl chloride as a construction material is a matter of controversy. With the purpose of carrying out a health characterization of the physical environment in Cienfuegos petrohouses, a descriptive study was conducted during two weeks selected from the dry and wet seasons of 2008 and 2009. Physical risk factors were monitored in a sample of 6 houses selected on the basis of expert opinion, of the total 104 houses in the village, according to their location in the rows: front, mid and end positions. The variables studied were noise, magnetic component of the low frequency electromagnetic field, natural and artificial lighting, microclimate and wind penetration. Monitoring was evaluated with statistical descriptors, regression models, variance and bivariate power spectrum, with the statistical software SPSS v. 17.0 and Statistica v. 8.0. In the dry season, air temperature is higher in the main room of houses with facades facing the south. In both seasons, temperature and relative humidity values are higher inside the houses than outside. Covers and walls heat up when hit by the sun. Natural lighting coefficients show high reflection values. Electromagnetic field values are low. In the dry season, sound levels show moderate acoustic contamination. It is concluded that the microclimate inside houses during the day is uncomfortable(AU)

Nonlinear responses for chromosome and gene level effects induced by vinyl acetate monomer and its metabolite, acetaldehyde in TK6 cells.

Vinyl acetate monomer (VAM) produced rat nasal tumors at concentrations in the hundreds of parts per million. However, VAM is weakly genotoxic in vitro and shows no genotoxicity in vivo. A European Union Risk Assessment concluded that VAM's hydrolysis to acetaldehyde (AA), via carboxylesterase, is a critical key event in VAM's carcinogenic potential. In the following study, we observed increases in micronuclei (MN) and thymidine kinase (Tk) mutants that were dependent on the ability of TK6 cell culture conditions to rapidly hydrolyze VAM to AA. Heat-inactivated horse serum demonstrated a high capacity to hydrolyze VAM to AA; this activity was highly correlated with a concomitant increase in MN. In contrast, heat-inactivated fetal bovine serum (FBS) did not hydrolyze VAM and no increase in MN was observed. AA's ability to induce MN was not impacted by either serum since it directly forms Schiff bases with DNA and proteins. Increased mutant frequency at the Tk locus was similarly mitigated when AA formation was not sufficiently rapid, such as incubating VAM in the presence of FBS for 4 hr. Interestingly, neither VAM nor AA induced mutations at the HPRT locus. Finally, cytotoxicity paralleled genotoxicity demonstrating that a small degree of cytotoxicity occurred prior to increases in MN. These results established 0.25 mM as a consistent concentration where genotoxicity first occurred for both VAM and AA provided VAM is hydrolyzed to AA. This information further informs significant key events related to the mode of action of VAM-induced nasal mucosal tumors in rats.

Subcutaneous tissue reaction and cytotoxicity of polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene blends associated with natural polymers.

Cytotoxicity and subcutaneous tissue reaction of innovative blends composed by polyvinylidene fluoride and polyvinylidene fluoride-trifluoroethylene associated with natural polymers (natural rubber and native starch) forming membranes were evaluated, aiming its applications associated with bone regeneration. Cytotoxicity was evaluated in mouse fibroblasts culture cells (NIH3T3) using trypan blue staining. Tissue response was in vivo evaluated by subcutaneous implantation of materials in rats, taking into account the presence of necrosis and connective tissue capsule around implanted materials after 7, 14, 21, 28, 35, 60, and 100 days of surgery. The pattern of inflammation was evaluated by histomorphometry of the inflammatory cells. Chemical and morphological changes of implanted materials after 60 and 100 days were evaluated by Fourier transform infrared (FTIR) absorption spectroscopy and scanning electron microscopy (SEM) images. Cytotoxicity tests indicated a good tolerance of the cells to the biomaterial. The in vivo tissue response of all studied materials showed normal inflammatory pattern, characterized by a reduction of polymorphonuclear leukocytes and an increase in mononuclear leukocytes over the time (p < 0.05 Kruskal-Wallis). On day 60, microscopic analysis showed regression of the chronic inflammatory process around all materials. FTIR showed no changes in chemical composition of materials due to implantation, whereas SEM demonstrated the delivery of starch in the medium. Therefore, the results of the tests performed in vitro and in vivo show that the innovative blends can further be used as biomaterials.

Clasificación de materiales plásticos sanitarios desechables y búsqueda de alternativas sin policloruro de vinilo en el Hospital Virgen de las Nieves / Classification of disposable medical plastics and search for alternatives without polyvinyl chloride in the Hospital Virgen de las Nieves (Granada, Spain)

Objetivos. identificación y clasificación de los productos hospitalarios desechables que contengan policloruro de vinilo (PVC), integrando la búsqueda y valoración de productos alternativos libres de PVC sustentables desde un punto de vista coste/efectivo. Métodos. análisis de tipo descriptivo observacional. Se realizó en primer lugar una clasificación de los trabajos de investigación más recientes en las principales bases de datos. Seguidamente, se clasificaron los productos desechables susceptibles de contener PVC, dividiéndolos en 5 grupos: cánulas, sondas, tubos, bolsas y equipos enmarcados en el periodo de consumo 2008-2009, diferenciando la valoración técnica y económica de los materiales. Resultados. en el estudio se observa que de los 492 artículos analizados en su composición, 234 (47,5%) contienen PVC y las alternativas libres del compuesto conforman el 19,4%, siendo viable económicamente solo el 11,3% de las alternativas valoradas. Conclusiones. la investigación aclara las ventajas derivadas de la clasificación de productos con PVC, existiendo alternativas seguras y eficientes para algunas líneas de productos, en consonancia con la seguridad de los pacientes y la calidad en el trabajo por parte de los facultativos (AU)

Objectives. To identify and classify disposable hospital products containing polyvinyl chloride (PVC), including the search and evaluation of cost-effective sustainable alternative products free of PVC. Methods. A descriptive observational analysis was performed, after classifying the latest research in major databases, and disposable products that could contain PVC. These were divided into 5 groups: cannulas, catheters, tubes, bags, and equipment, purchased in the period 2008-2009, differentiating between the technical and economic assessment of the materials. Results. In the analysis of the composition of 492 articles selected, 234 (47.5%) contained PVC, and 19.4% were considered PVC-free alternatives, with only 11.3% of these being economically viable. Conclusions. This study highlights the advantages of the classification of PVC products, by showing that safe and efficient alternatives exist for some product lines that are consistent with patient safety and quality in the work by doctors (AU)

Vinyl isolator breeding induces insulin resistance in C57BL/6JJcl mice.

As basic probiotics studies, the glucose tolerance test (GTT), insulin tolerance test (ITT), and adipokine and hepatic enzyme activities were investigated in male C57BL/6JJcl (B6J) mice under germfree (GF) or specific pathogen free (SPF) conditions. GF B6J mice were reproduced by reproductive engineering and cesarean section using a vinyl isolators (GF group). Some GF group mice were transferred to other vinyl isolators under SPF conditions (SPF group). In addition, conventional B6J mice bred in an open room were defined as controls (Conv group). GTT, ITT, and the sampling of blood, liver, white adipose tissue, and pancreas were performed when these B6J mice were at the age of 8 weeks. As a result, the GF and SPF groups showed hyperglycemia, impaired glucose tolerance and insulin resistance when compared with the Conv group. The adipose tissues and plasma TNFα concentrations in the GF and SPF groups were enlarged and increased when compared with the Conv group. Hepatic enzyme activities associated with glucose uptake in the GF and SPF groups were higher than those in the Conv group. However, hepatic enzyme activities associated with gluconeogenesis in the GF and SPF groups were lower than those in the Conv group. We assumed that these results were reactions by the liver to recover from the impaired glucose tolerance and the insulin resistance caused by vinyl isolator breeding of the GF and SPF groups by control of glucose metabolism.