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OBJECTIVES: This study identified changes in the work environment due to the COVID-19 pandemic, subsequent initiatives and outcomes, and facilitating factors from the perspective of company officials in small- and medium-sized enterprises (SMEs). METHODS: In 2021, semi-structured interviews were conducted with employers or human resource managers of SMEs with less than 300 employees regarding changes in the work environment due to the pandemic, initiatives, outcomes, and facilitating factors. Thereafter, codes were extracted from verbatim transcripts or interview notes and categorized based on similarities in content. RESULTS: Based on interviews with 16 companies, the following four major categories of changes in the work environment were identified: "conflict and anxiety about infection when employees were forced to attend work despite the rapid transmission of the infection," "unfamiliarity and loneliness with the new working style that was suddenly imposed on them," "loss of emotional ties with workmates and opportunities for mood changes," and "future anxiety, feelings of alienation, and mental illness." The following seven initiatives were implemented to address these issues: "a hands-on approach to infection prevention and physical healthcare," "urgent introduction of telework for business continuity," "development and promotion of online information sharing," "establishment of a place and opportunity to maintain emotional connections within the company," "economic and management measures to protect employees and ensure company continuity," "support for employees for health maintenance," and "measures to respond to employees' needs and ideas, and support the continuation of activities." Four major categories of outcomes were: "increased efficiency of information sharing and enhanced performance," "maintenance and promotion of emotional ties and a sense of solidarity," "increased independence and sense of health among employees," and "adaptation of employees to novel situations." The initiatives were facilitated by factors classified into the following three major categories: "workplace culture wherein employees shared opinions and helped each other," "management's attitude and philosophy of valuing employees," and "proactive attitude toward information acquisition and resource utilization." CONCLUSIONS: The rapid introduction of teleworking as a new working style in response to the need to balance infection control and business continuity resulted in increased loneliness and other associated stressors. Many SMEs stated that they could maintain a sense of solidarity in the workplace and improve employee autonomy through their efforts to incorporate employees' opinions and maintain human connections.
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COVID-19 , Saúde Ocupacional , Humanos , Condições de Trabalho , Pandemias/prevenção & controle , COVID-19/prevenção & controle , Local de Trabalho/psicologia , AtitudeRESUMO
Background and Objectives: Mimasaka city is a relatively small city with a population of 28,381, and an aging rate (≥65 years old) of 38.9%, where only one nephrology clinic is available. Since 2013, the city has conducted its own unique lifestyle intervention for the participants of the National Health Insurance specific medical health checkup, aiming to prevent the progression of chronic kidney disease (CKD) severity. Materials and Methods: The persons in National Health Insurance specific medical health checkup (40−74 years old) conducted in Mimasaka city in 2013, with eGFR less than 50 mL/min/1.73 m² or 50−90 mL/min/1.73 m² with urine dipstick protein 1+ or more, were registered for the CKD follow-up project, as high-risk subjects for advanced renal dysfunction. Municipal workers directly visited the subjects' homes to provide individual health guidance and encourage medical consultation. We aimed to examine the effect of home-visit intervention on the changes of renal function and related factors until 2017. Results: The number of the high-risk subjects who continuously received the health checkup until 2017 was 63, and only 23 (36.5%) visited a medical institution in the first year. The eGFR decreased by only 0.4 mL/min/1.73 m²/year, and the subjects with urinary protein 1+ or higher decreased significantly from 20 (31.7%) to 9 (14.3%) (p = 0.034) in the high-risk subjects. The changes in eGFR and urinary protein was almost in the same fashion regardless of their medical institution visits. Next, we examined the effects of various factors on ΔeGFR, the changes of eGFR from 2013 to 2017, by multivariate linear regression analysis. The effects of medical institution visit were not significant, and the degree of urinary protein (coefficient B: 4.503, ß: 0.705, p < 0.001), age (coefficient B: 4.753, ß: 0.341, p = 0.004), and smoking (coefficient B: 5.878, ß: 0.295, p = 0.031) had independent significant effects, indicating that they were the factors exacerbating the decrease in eGFR from the baseline. Conclusions: The personalized lifestyle intervention by home-visit in CKD follow-up project showed the possibility of beneficial effects on the deterioration of renal function. This may be an efficient method to change behavior in a small community with limited medical resources.
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Insuficiência Renal Crônica , Humanos , Idoso , Adulto , Pessoa de Meia-Idade , Estudos de Coortes , Taxa de Filtração Glomerular , Seguimentos , Insuficiência Renal Crônica/terapia , Insuficiência Renal Crônica/epidemiologia , Estilo de Vida , Programas Nacionais de Saúde , Progressão da DoençaRESUMO
With the aim of sharing information about the technical aspects of immunohistochemistry (IHC) and facilitating the selection of suitable antibodies for histopathological examination, this technical report describes the results of a questionnaire distributed during the period of 2018 to 2019 among members of the Conference on Experimental Animal Histopathology. Additionally, it describes the immunological properties and supplier details (clone, supplier, catalog number, species reactivity, etc.) as well as the IHC staining conditions (fixing solution, fixing time, embedding, antigen retrieval method, antibody dilution, incubation time, incubation temperature, positive control tissue, blocking condition, secondary antibody information, etc.) for a total of 509 primary antibodies (comprising 220 different types). These survey results were an update on the contents reported by CEAH in 2017.
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The Standard for Exchange of Nonclinical Data (SEND) has been adopted by the US FDA, which has required pharmaceutical companies who are developing new drugs for the US market to implement SEND. The Japan Pharmaceutical Manufacturers Association (JPMA) SEND Taskforce Team responded to this situation by starting a project to better understand the contents of SEND datasets. The project focused on domains generally included in the SEND domains for single- and repeat-dose general toxicology studies, and surveyed what kind of information are populated in which domains and in what way. The qualitative analysis of the results indicated that variations exist based on whether or not an individual variable was populated and on how the variable was populated. The Taskforce Team recommends reducing variations not only in the SEND datasets but also in the descriptions in the study protocol and/or final study report. Reduction of such variations should lead to higher quality datasets with powerful and increased searchability so that accumulated SEND datasets should become more valuable. These efforts would provide regulatory agencies with easier review of SEND datasets, which contributes to efficient development of new drug candidates.
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Pesquisa Biomédica/normas , Bases de Dados como Assunto/normas , Indústria Farmacêutica/normas , Pesquisa Biomédica/organização & administração , Drogas em Investigação/normas , Humanos , Japão , Estados Unidos , United States Food and Drug Administration/normasRESUMO
Here, we reported a spontaneous case of membranoproliferative glomerulonephritis observed in a young ICR mouse. A 5-week-old female mouse was euthanized owing to abdominal swelling and increased body weight. At necropsy, generalized subcutaneous edema, and clear, colorless, non-viscous ascites were observed. Histologically, the kidneys showed diffuse, bilateral glomerular lesions. The lesions were characterized by thickening and double contour of the basement membrane and an increase in mesangial cells and matrix, resulting in the narrowing of the capillary lumen. Additionally, eosinophilic hyaloid material accumulated in the subendothelial areas and Bowman's space. The material was positive for periodic acid-Schiff, complement component C3, or immunoglobulin G, stained red by Masson's trichrome, and stained blue by phosphotungstic acid-hematoxylin stain and was considered to be plasma due to glomerular leakage. The glomerular lesion was diagnosed as membranoproliferative glomerulonephritis, and an uncertain endothelial injury was suspected as the cause.
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The adrenal gland is the most common toxicological target of drugs within the endocrine system, and inhibition of adrenal steroidogenesis can be fatal in humans. However, methods to evaluate the adrenal toxicity are limited. The aim of the present study was to verify the usefulness of simultaneous measurement of blood levels of multiple adrenal steroids, including precursors, as a method to evaluate drug effects on adrenal steroidogenesis in cynomolgus monkeys. With this aim, physiological and drug-induced changes in blood levels of adrenal steroids, including cortisol, aldosterone, androgen, and their precursors were examined. First, for physiological changes, intraday and interday changes in blood steroid levels were examined in male and female cynomolgus monkeys. The animals showed circadian changes in steroid levels that are similar to those in humans, while interday changes were relatively small in males. Next, using males, changes in blood steroid levels induced by ketoconazole and metyrapone were examined, which suppress adrenal steroidogenesis via inhibition of CYP enzymes. Consistent with rats and humans, both ketoconazole and metyrapone increased the deoxycorticosterone and deoxycortisol levels, probably via CYP11B1 inhibition, and the increase was observed earlier and with greater dynamic range than the changes in cortisol level. Changes in other steroid levels reflecting the drug mechanisms were also observed. In conclusion, this study showed that in cynomolgus monkeys, simultaneous measurement of blood levels of adrenal steroids, including precursors, can be a valuable method to sensitively evaluate drug effects on adrenal steroidogenesis and to investigate the underlying mechanisms.
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Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Aldosterona/sangue , Aldosterona/metabolismo , Androgênios/sangue , Androgênios/metabolismo , Cromatografia Líquida/métodos , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Cetoconazol/toxicidade , Metirapona/toxicidade , Espectrometria de Massas em Tandem/métodos , Animais , Ritmo Circadiano , Desoxicorticosterona/metabolismo , Feminino , Humanos , Macaca fascicularis , Masculino , Esteroide 11-beta-Hidroxilase/antagonistas & inibidoresRESUMO
To verify simultaneous measurement of blood levels of adrenal steroids as a tool to evaluate drug effects on adrenal steroidogenesis, dose- and time-dependent changes in blood levels of corticosterone and its precursors (pregnenolone, progesterone and deoxycorticosterone), as well as their relationship with the pathological changes in the adrenal gland, were examined in rats dosed with ketoconazole (KET). Also examined were whether effects on adrenal steroidogenesis that were not obvious in the blood steroid levels after sole administration of KET could be revealed by post-administration of ACTH, and the correlation between the blood and adrenal steroid levels. Male rats were dosed with 15, 50, or 150 mg/kg of KET for 1 or 7 days with or without ACTH, and the blood and adrenal concentrations of the steroids were measured. KET increased the blood deoxycorticosterone level even at a dose level and time point at which histopathological changes were not obvious. KET-induced changes in blood levels of other steroids were revealed by ACTH, and the blood and adrenal levels were generally correlated especially after ACTH post-administration. Thus, blood levels of adrenal steroids, including precursors, can be a sensitive and early marker of drug effects on the adrenal steroidogenesis that reflect adrenal levels of steroids. The usefulness of the multiple steroid measurement as a method for mechanism investigation of drug effects on the adrenal gland can be further enhanced by ACTH.
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Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Desoxicorticosterona/sangue , Desoxicorticosterona/metabolismo , Cetoconazol/toxicidade , Pregnenolona/sangue , Pregnenolona/metabolismo , Progesterona/sangue , Progesterona/metabolismo , Glândulas Suprarrenais/patologia , Hormônio Adrenocorticotrópico/administração & dosagem , Animais , Cromatografia Líquida , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Fatores de TempoRESUMO
The thermotolerant yeast Kluyveromyces marxianus, growing at high temperature (45â) , showed stronger survival under heat shock at 50â than the brewing yeast Saccharomyces cerevisiae, which was unable to grow at 45â. The survival rate of K. marxianus decreased to 10% during heat shock at 50â for 20 min, and to less than 0.01% at 60â for 20 min. Cells with damaged cellular membranes were infrequently observed at 50â and had decreased significantly from heat shock at 60â. The metabolic activity of K. marxianus was retained at 50â, whereas that of S. cerevisiae was not. The trehalose content of K. marxianus was approximately two times that of S. cerevisiae. These results suggest that K. marxianus protects itself from heat shock-induced damage through the use of trehalose (a protective molecule in S. cerevisiae) as well as other different factors.
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Kluyveromyces/fisiologia , Termotolerância/fisiologia , Trealose/metabolismo , Membrana Celular/química , Resposta ao Choque Térmico , Temperatura Alta , Kluyveromyces/química , Viabilidade Microbiana , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/fisiologia , Especificidade da EspécieRESUMO
The aim of this study was to evaluate the usefulness of simultaneous measurement of plasma steroids, including precursors, for the evaluation of drug effects on adrenal steroidogenesis in vivo. Plasma concentrations of corticosterone and its precursors were examined in rats dosed with compounds that affect adrenal steroidogenesis via different modes of action as well as the relationships of the changes with blood chemistry and adrenal histopathology. Male rats were dosed with tricresyl phosphate, aminoglutethimide, trilostane (TRL), metyrapone (MET), ketoconazole (KET), or mifepristone for 7 days. In the TRL, MET, and KET groups, precursor levels were markedly increased, while there were no significant changes in the corticosterone level, suggesting that the precursors are more sensitive biomarkers to detect the effect on adrenal steroidogenesis. Also, the precursors with increased levels were those that are normally metabolized by the inhibited enzymes, reflecting the modes of action of the compounds. In addition, different patterns of changes were observed in blood chemistry and histopathology, supporting the mechanism suggested by the steroid changes. These results show that simultaneous measurement of plasma steroids, including precursors, can be a valuable method to sensitively evaluate drug effects on adrenal steroidogenesis and to investigate the underlying mechanisms.
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Glândulas Suprarrenais/efeitos dos fármacos , Corticosterona/biossíntese , Corticosterona/sangue , Monitoramento de Medicamentos/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/sangue , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Animais , Peso Corporal/efeitos dos fármacos , Desoxicorticosterona/sangue , Masculino , Tamanho do Órgão/efeitos dos fármacos , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/metabolismo , Pregnenolona/sangue , Progesterona/sangue , Ratos , Ratos Sprague-DawleyRESUMO
The human renin-angiotensinogen double transgenic rat (dTGR) is a model of hypertension. The aim of this short report was to describe the histopathological characteristics of the renal changes in this rat strain in detail. Seven to nine-week-old male dTGRs were euthanized, and their kidneys were histopathologically examined. At the time of sacrifice, the average systolic blood pressure of the dTGRs was 258 mmHg, while that of age-matched, normal Sprague-Dawley rats was 135 mmHg. In the kidney, histopathological changes were observed mainly in blood vessels, tubules and glomeruli. In blood vessels, changes including medial hypertrophy, intimal thickening, hyaline change and/or fibrinoid necrosis were observed in arteries and arterioles. In tubules, changes including tubular basophilia were observed radially, mainly around interlobular arteries with lesions. In glomeruli, changes including hyaline droplet accumulation in podocytes, which was accompanied by increased expression of desmin, were observed. These changes were similar to those reported in other hypertension models, such as the spontaneously hypertensive rat (SHR). We hope that this short report will be helpful in histopathological examination of renal changes in this or other hypertension models.
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The adrenal gland is the most common toxicological target in the endocrine system, and inhibition of adrenal steroidogenesis by drugs can be fatal in humans. However, methods to evaluate the drug effect are limited. Recently, simultaneous measurement of multiple steroids, including precursors, has become possible. Here, we evaluated the usefulness of this simultaneous measurement for the evaluation of drug effects on adrenal steroidogenesis in vivo. For this purpose, we measured plasma concentrations of adrenal steroids in rats dosed with ketoconazole, a known inhibitor of adrenal steroidogenesis, and examined its relationship with the changes in histopathology and mRNA expression of steroidogenic enzymes in the adrenal gland. Ketoconazole (150mg/kg/day) was orally administered to male rats for 7 days. The adrenal weight was high, and the zona fasciculata/reticularis were hypertrophic with an accumulation of lipid droplets. mRNA expression of CYP11A1, a rate-limiting enzyme in adrenal steroidogenesis, was slightly high in the adrenal gland. Plasma concentration of deoxycorticosterone was markedly high, while there were no significant changes in that of corticosterone, progesterone, or pregnenolone. The changes in the adrenal gland and plasma concentration of steroids were thought to reflect inhibited metabolism of deoxycorticosterone to corticosterone through inhibition of CYP11B1, and compensatory reaction for the inhibition. The compensatory reaction was thought to have masked decrease of corticosterone. These results suggest that simultaneous measurement of multiple steroids can enable sensitive evaluation of drug effects on adrenal steroidogenesis in vivo, while providing insight into the underlying mechanism of the effect.
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Glândulas Suprarrenais/efeitos dos fármacos , Corticosterona/sangue , Desoxicorticosterona/sangue , Cetoconazol/toxicidade , Administração Oral , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Animais , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Cetoconazol/administração & dosagem , Antígeno Ki-67/metabolismo , Masculino , Ratos Sprague-DawleyRESUMO
A male domestic ferret (Mustela putorius furo), which was purchased from outside of Japan at 13 weeks of age, was euthanized at 18 months of age because of poor health. At autopsy, the liver, spleen, and mesenteric lymph node were enlarged, and white foci were observed on the outer surface of the liver. The outer surface of the mesenteric lymph node was dark red. Histologically, granulomas were observed in the liver, spleen, bone marrow, and lymph nodes, composed mainly of aggregated epithelioid macrophages, some of which were positive to an anti-feline coronavirus (FCoV; Alphacoronavirus 1) antibody in immunohistochemistry. Mesangioproliferative glomerulonephritis was observed, and periodic acid-Schiff-positive deposits were observed along glomerular capillary walls. These deposits stained pale red with periodic acid-methenamine silver stain and red with Masson trichrome stain, and were also observed in the mesangial matrix. In affected glomeruli, glomerular capillary walls and mesangial areas were positive for anti-ferret immunoglobulin G. By electron microscopy, subepithelial and mesangial electron-dense deposits were observed consistent with immune complex deposition. The deposition of immune complexes may have been associated with FCoV infection.
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Infecções por Coronavirus/veterinária , Coronavirus Felino/isolamento & purificação , Furões , Glomerulonefrite/veterinária , Animais , Medula Óssea/patologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/patologia , Coronavirus Felino/imunologia , Diagnóstico Diferencial , Glomerulonefrite/complicações , Glomerulonefrite/diagnóstico , Glomerulonefrite/patologia , Imuno-Histoquímica/veterinária , Japão , Fígado/patologia , Linfonodos/patologia , Masculino , Baço/patologiaRESUMO
A compact facility for SPF mice that was not equipped with a large autoclave used disposable mouse cages instead. The SPF clean room was 5.7 × 8.1 × 2.7 m(3), with a breeding capacity of 1008 cages (168 cages on each of 6 racks). We evaluated cleanliness in the SPF clean room under the conditions of an occupation rate of 60% to 70% and typically 1 to 3 personnel (maximum, 4 to 6) daily on weekdays. Personnel were taught standard procedures and received training beforehand. During the 15-mo study period, the maximal concentration of airborne particles 0.5 µm or larger was 1.0 × 10(4) particles/m3 and that of particles 5.0 µm or larger was 5.0 × 10(2) particles/m(3)--well below the maximal permissible concentrations of 3.52 × 10(5) and 2.93 × 10(3) particles/m(3), respectively. During the study period, no mice exhibited clinical symptoms of infection. Testing of 2 representative, overtly healthy mice for 16 pathogens including Staphylococcus aureus, Pseudomonas aeruginosa, and Helicobacter bilis failed to detect any of the target agents. The current study demonstrates the feasibility of the compact facility for breeding SPF mice in the academic environment.
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Ambiente Controlado , Abrigo para Animais , Camundongos , Organismos Livres de Patógenos Específicos , Animais , Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/veterinária , Cruzamento , Microbiologia Ambiental , Abrigo para Animais/normas , Ciência dos Animais de Laboratório/métodos , Ciência dos Animais de Laboratório/normasRESUMO
The common marmoset (Callithrix jacchus) is now widely used in various research fields, including toxicology. However, information about the background pathology of this species is scarce. Here, we report a case of rhabdomyosarcoma that spontaneously occurred in a common marmoset. A 44-month-old male common marmoset was euthanized due to bilateral hind limb paralysis. At necropsy, a 2×2×5-cm intramuscular mass was observed in the lower right back. Histologically, the mass was mainly composed of interlacing bundles of spindle-shaped tumor cells. Immunohistochemically, the tumor cells were positive for myogenin, desmin, vimentin and alpha-smooth muscle actin. Ultrastructurally, the tumor cells contained bundles of myofilaments with Z-band-like structures. Thus, the tumor was diagnosed as a rhabdomyosarcoma. To our knowledge, this is the first report of spontaneous rhabdomyosarcoma that was definitely diagnosed in the common marmoset.
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Clobazam (CLB) is known to increase hepatobiliary thyroxine (T4) clearance in Sprague-Dawley (SD) rats, which results in hypothyroidism followed by thyroid follicular cell hypertrophy. However, the mechanism of the acceleration of T4-clearance has not been fully investigated. In the present study, we tried to clarify the roles of hepatic UDP-glucronosyltransferase (UGT) isoenzymes (UGT1A and UGT2B) and efflux transporter (multidrug resistance-associated protein-2; MRP2) in the CLB-induced acceleration of T4-clearance using two mutant rat strains, UGT1A-deficient mutant (Gunn) and MRP2-deficient mutant (EHBR) rats, especially focusing on thyroid morphology, levels of circulating hormones (T4 and triiodothyronine (T3)) and thyroid-stimulating hormone (TSH), and mRNA or protein expressions of UGTs (Ugt1a1, Ugt1a6, and Ugt2b1/2) and MRP2 (Mrp). CLB induced thyroid morphological changes with increases in TSH in SD and Gunn rats, but not in EHBR rats. T4 was slightly decreased in SD and Gunn rats, and T3 was decreased in Gunn rats, whereas these hormones were maintained in EHBR rats. Hepatic Ugt1a1, Ugt1a6, Ugt2b1/2, and Mrp2 mRNAs were upregulated in SD rats. In Gunn rats, UGT1A mRNAs (Ugt1a1/6) and protein levels were quite low, but UGT2B mRNAs (Ugt2b1/2) and protein were prominently upregulated. In SD and Gunn rats, MRP2 mRNA and protein were upregulated to the same degree. These results suggest that MRP2 is an important contributor in development of the thyroid cellular hypertrophy in CLB-treated rats, and that UGT1A and UGT2B work in concert with MRP2 in the presence of MRP2 function to enable the effective elimination of thyroid hormones.
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Anticonvulsivantes/farmacologia , Benzodiazepinas/farmacologia , Glucuronosiltransferase/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/patologia , Animais , Clobazam , Expressão Gênica/efeitos dos fármacos , Glucuronosiltransferase/biossíntese , Glucuronosiltransferase/metabolismo , Histocitoquímica , Hipertrofia , Isoenzimas/biossíntese , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/biossíntese , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Distribuição Aleatória , Ratos , Ratos Gunn , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Glândula Tireoide/enzimologia , Glândula Tireoide/metabolismo , Hormônios Tireóideos/sangue , Hormônios Tireóideos/metabolismoRESUMO
A female congenic rat produced by repeated backcrossing of Nihon rats, a model for hereditary renal cell carcinoma, to Brown Norway rats was necropsied at 24 months of age. At necropsy, a white mass about 1 centimeter in size was observed in the thoracic cavity, and the mass partly adhered to the esophagus and the diaphragm. Histologically, the mass was clearly circumscribed by connective tissue, and consisted of neoplastic cuboidal epithelial cells that showed cystic tubular proliferation. Some islands of well-differentiated hepatocytes and some vessels were observed in the mass. Immunohistochemically, the tumor cells were strongly positive for cytokeratin and partly positive for vimentin but were negative for mesothelin and Von Willebrand Factor. The positive rate for Ki-67 was 2.4%. Based on these histological and immunohistochemical evidences, we diagnosed this tumor as a cystic cholangioma that might have arisen from the ectopic hepatic tissue in the thoracic cavity.
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Hyaline glomerulopathy with tubulo-fibrillary deposits was observed in two young female ddY mice. One of the mice showed gross systemic edema and bilateral enlargement and pale color of the kidneys, whereas no significant gross findings were noted in the other mouse. Microscopically, a large number of the glomeruli in both mice were enlarged because of diffuse and global deposition of amorphous eosinophilic materials. The deposits were negatively stained with Congo red and positively stained with IgG, IgM, IgA, C3, and periodic acid-Schiff. Electron microscopic examination revealed microtubular and fibrillary deposits with diameters of 80-100 and 9-16 nm, respectively, in the subendothelial space of the glomeruli. These features are histopathologically similar to immunotactoid glomerulopathy or fibrillary glomerulonephritis according to the classification of human glomerular lesions. Understanding of these characteristics of hyaline glomerulopathy in ddY mice is essential when evaluating pharmacological, pharmacokinetic, and toxicological studies using this mouse strain.
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Glomerulonefrite/patologia , Hialina/metabolismo , Glomérulos Renais/patologia , Glomérulos Renais/ultraestrutura , Animais , Feminino , Glomerulonefrite/diagnóstico , Glomerulonefrite/metabolismo , Imuno-Histoquímica , Camundongos , Camundongos EndogâmicosRESUMO
Antiepileptic agents are known to cause adverse effects in human liver, including steatosis. Clobazam (CLB), a 1,5-benzodiazepine, is clinically used as an antiepileptic agent. In the previous study, 4-week treatment with CLB induced hepatomegaly in male rats. In the present study, the human risk of hepatomegaly was assessed and the causative mechanism in terms of cell proliferation and apoptosis, oxidative stress, and drug-metabolizing enzyme induction was elucidated by toxicological approach. Male SD rats were treated orally with 400 mg/kg CLB for 1, 3, 7, 14, or 28 days. The 28-day treatment was followed by 7 or 14 days of withdrawal. At the end of each treatment, the liver and plasma of each rat were examined. Liver weight increased from Day 3 of CLB treatment. This increase was mostly accompanied by hepatic centrilobular hypertrophy and proliferation of smooth endoplasmic reticulum (SER), and by an increase in microsomal proteins. Cyp2b1, Cyp3a1, Cyp3a2, and Ugt2b2 mRNA levels in the liver were upregulated as compared to the control group throughout the dosing period. On the other hand, the thiobarbituric acid reactive substance (TBARS) formulation, hepatocyte proliferation, and apoptosis, assumed to play roles in laying groundwork for effective induction of metabolizing enzymes, were increased only at the acute phase of treatment. These results suggested that CLB-induced hepatomegaly in male rats is mainly attributable to microsomal enzyme induction associated with Cyp2b1, Cyp3a1, Cyp3a2, and Ugt2b2 gene upregulation, but does not cause any toxicological concerns.
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Anticonvulsivantes/toxicidade , Benzodiazepinas/toxicidade , Hepatomegalia/induzido quimicamente , Inativação Metabólica/genética , Animais , Apoptose/efeitos dos fármacos , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Proliferação de Células/efeitos dos fármacos , Clobazam , Citocromo P-450 CYP2B1/genética , Citocromo P-450 CYP2B1/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Hepatomegalia/genética , Hepatomegalia/metabolismo , Hepatomegalia/patologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Fígado/patologia , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Microssomos Hepáticos/patologia , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
In the present study, we investigated the histological, immunohistochemical and ultrastructural characteristics of cytoplasmic blood plasma inclusions that spontaneously occurred in a rat liver. Histologically, a number of cytoplasmic inclusions were observed in the liver of an 8-week-old female SD rat. These inclusions were strongly positive for PAS staining and resistant to diastase digestion. Immunohistochemical analyses revealed that these inclusions were positive for albumin and IgG; however, most of them were negative for LAMP-1 and LAMP-2. Ultrastructurally, the inclusions were surrounded by limiting membranes and composed of moderately electron dense, homogenous materials. These characteristics described here represent valuable information for pathological examination in toxicity studies.