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It has recently been shown that the aging population is refractory to the maintenance of swallowing function, which can seriously affect quality of life. Singing and vocal training contribute to mastication, swallowing and respiratory function. Previous studies have shown that singers have better vocal cord health. No consensus has been reached as to how vocal training affects swallowing ability. Our study was designed to establish evidence that singers are statistically superior at inducing the swallowing reflex. To test our hypothesis, we undertook a clinical trial on 55 singers and 141 non-singers (mean age: 60.1 ± 11.7 years). This cross-sectional study with propensity score matching resulted in significant differences in a repetitive saliva swallowing test among singers: 7.1 ± 2.4, n = 53 vs. non-singers: 5.9 ± 1.9, n = 53, p < 0.05. We conclude that singing can serve an important role in stabilizing the impact of voluntary swallowing on speech.
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KEY MESSAGE: This study describes biological functions of the bHLH transcription factor RERJ1 involved in the jasmonate response and the related defense-associated metabolic pathways in rice, with particular focus on deciphering the regulatory mechanisms underlying stress-induced volatile emission and herbivory resistance. RERJ1 is rapidly and drastically induced by wounding and jasmonate treatment but its biological function remains unknown as yet. Here we provide evidence of the biological function of RERJ1 in plant defense, specifically in response to herbivory and pathogen attack, and offer insights into the RERJ1-mediated regulation of metabolic pathways of specialized defense compounds, such as monoterpene linalool, in possible collaboration with OsMYC2-a well-known master regulator in jasmonate signaling. In rice (Oryza sativa L.), the basic helix-loop-helix (bHLH) family transcription factor RERJ1 is induced under environmental stresses, such as wounding and drought, which are closely linked to jasmonate (JA) accumulation. Here, we investigated the biological function of RERJ1 in response to biotic stresses, such as herbivory and pathogen infection, using an RERJ1-defective mutant. Transcriptome analysis of the rerj1-Tos17 mutant revealed that RERJ1 regulated the expression of a typical family of conserved JA-responsive genes (e.g., terpene synthases, proteinase inhibitors, and jasmonate ZIM domain proteins). Upon exposure to armyworm attack, the rerj1-Tos17 mutant exhibited more severe damage than the wildtype, and significant weight gain of the larvae fed on the mutant was observed. Upon Xanthomonas oryzae infection, the rerj1-Tos17 mutant developed more severe symptoms than the wildtype. Among RERJ1-regulated terpene synthases, linalool synthase expression was markedly disrupted and linalool emission after wounding was significantly decreased in the rerj1-Tos17 mutant. RERJ1 appears to interact with OsMYC2-a master regulator of JA signaling-and many OsJAZ proteins, although no obvious epistatic interaction was detected between them at the transcriptional level. These results indicate that RERJ1 is involved in the transcriptional induction of JA-mediated stress-responsive genes via physical association with OsMYC2 and mediates defense against herbivory and bacterial infection through JA signaling.
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Oryza , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Herbivoria , Oryza/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismoRESUMEN
BACKGROUND: Recent increased use of medical images induces further burden of their interpretation for physicians. A plain X-ray is a low-cost examination that has low-dose radiation exposure and high availability, although diagnosing urolithiasis using this method is not always easy. Since the advent of a convolutional neural network via deep learning in the 2000s, computer-aided diagnosis (CAD) has had a great impact on automatic image analysis in the urological field. The objective of our study was to develop a CAD system with deep learning architecture to detect urinary tract stones on a plain X-ray and to evaluate the model's accuracy. METHODS: We collected plain X-ray images of 1017 patients with a radio-opaque upper urinary tract stone. X-ray images (n = 827 and 190) were used as the training and test data, respectively. We used a 17-layer Residual Network as a convolutional neural network architecture for patch-wise training. The training data were repeatedly used until the best model accuracy was achieved within 300 runs. The F score, which is a harmonic mean of the sensitivity and positive predictive value (PPV) and represents the balance of the accuracy, was measured to evaluate the model's accuracy. RESULTS: Using deep learning, we developed a CAD model that needed 110 ms to provide an answer for each X-ray image. The best F score was 0.752, and the sensitivity and PPV were 0.872 and 0.662, respectively. When limited to a proximal ureter stone, the sensitivity and PPV were 0.925 and 0.876, respectively, and they were the lowest at mid-ureter. CONCLUSION: CAD of a plain X-ray may be a promising method to detect radio-opaque urinary tract stones with satisfactory sensitivity although the PPV could still be improved. The CAD model detects urinary tract stones quickly and automatically and has the potential to become a helpful screening modality especially for primary care physicians for diagnosing urolithiasis. Further study using a higher volume of data would improve the diagnostic performance of CAD models to detect urinary tract stones on a plain X-ray.
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Aprendizaje Profundo , Diagnóstico por Computador , Redes Neurales de la Computación , Radiografía , Cálculos Urinarios/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Conjuntos de Datos como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Interpretación de Imagen Radiográfica Asistida por Computador , Sensibilidad y EspecificidadRESUMEN
Introduction and Objectives: An ileal conduit (IC) is an established option for urinary diversion, despite the fact that early renal impairment (RI) sometimes occurs after surgery. The aim of this study was to investigate the incidence and risk factors of early RI. Materials and Methods: Thirty-one patients diagnosed with muscle-invasive bladder cancer who underwent RC with IC were analyzed in this study. Early RI was defined as a greater than 25% decrease in estimated glomerular filtration rate (eGFR) over the course of one year after surgery. The incidence and risk factors of early RI were evaluated. Results: The mean preoperative eGFR of the patients was 69.6 mL/min/1.73 m2. Early RI was observed in 7 (22.5%) patients. Multivariate analyses demonstrated that postoperative hydronephrosis was an independent risk factor for early RI (P=0.018). The mean intermediate-term eGFR change was -5.1 mL/min/1.73 m2 in patients with early RI and was greater than that (-2.9) in patients without early RI, although neither were statistically significantly different. Conclusion: Renal function after RC with IC decreased immediately over the course of one year, and postoperative hydronephrosis was an independent risk factor for early RI. Renal function had decreased slightly at intermediate-term follow-up with or without early RI.
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OBJECTIVES: To evaluate the incidence and predictors of acute kidney injury after clampless partial nephrectomy, and its impact on intermediate-term renal function. METHODS: The incidence and severity of acute kidney injury were assessed for 262 patients undergoing clampless partial nephrectomy between 2010 and 2015. The association between perioperative covariates and acute kidney injury was evaluated using multivariate logistic regression analysis. An annual change in estimated glomerular filtration rate from 1 year after surgery was calculated according to the presence or absence of acute kidney injury. An impact of acute kidney injury on postoperative renal impairment, defined as a ≥25% estimated glomerular filtration rate decrease, was evaluated. RESULTS: Overall, 21 (8.0%) patients experienced grade 1 acute kidney injury after clampless partial nephrectomy, and grade ≥2 acute kidney injury was not observed. High tumor complexity was the only independent predictor of acute kidney injury. Estimated glomerular filtration rate in patients with acute kidney injury improved within 1 year, and annual estimated glomerular filtration rate changes were similar among patients with or without acute kidney injury. Ultimately, 13 (5.0%) patients showed postoperative renal impairment during the median follow-up period of 37 months. Advanced age and diabetes mellitus were independent risk factors for renal impairment, but acute kidney injury was not. CONCLUSIONS: The incidence and severity of acute kidney injury after clampless partial nephrectomy are low. Low-grade acute kidney injury after clampless partial nephrectomy does not seem to affect intermediate-term renal function.
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Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Nefrectomía/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Factores de Riesgo , Análisis de Supervivencia , Resultado del Tratamiento , Isquemia TibiaRESUMEN
Renal angiomyolipoma without local invasion is usually considered benign entity, however, it may extend into the renal vein or the inferior vena cava. Renal angiomyolipoma with venous extension should be treated; however, surgical complications such as iatrogenic pulmonary fat embolism remain a serious concern. We present a case of a 66-year-old Japanese woman without tuberous sclerosis in whom a right-sided renal tumor was incidentally detected on ultrasonography during a health check-up. Further evaluation showed that the tumor extended into the renal vein, and she was successfully treated using preoperative inferior vena cava filter placement and radical nephrectomy. An inferior vena cava filter can prevent catastrophic pulmonary fat embolism during nephrectomy.
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INTRODUCTION: This study is aimed at evaluating the incidence and predictors of adherent perinephric fat (APF) in Asians during partial nephrectomy (PN), and determining the impact of APF on perioperative outcomes. MATERIALS AND METHODS: A total of 231 Asian patients with renal tumors underwent PN, and their Mayo adhesive probability (MAP) score was calculated. APF was intraoperatively determined, and the perioperative data were compared according to the presence of APF. The predictors of APF were examined using logistic regression analyses. RESULTS: APF was observed in 40 (17%) patients. In multivariate analysis, male gender and higher MAP score were the independent predictors of APF. The estimated blood loss was higher in patients with APF, however, the complication rates did not differ between the 2 groups. CONCLUSIONS: The MAP score can predict APF in an Asian population. The presence of APF was associated with greater blood loss; however it did not increase the postoperative complications in PN.
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Tejido Adiposo/patología , Neoplasias Renales/etnología , Neoplasias Renales/cirugía , Riñón/patología , Nefrectomía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Pueblo Asiatico , Índice de Masa Corporal , Femenino , Humanos , Incidencia , Riñón/cirugía , Masculino , Persona de Mediana Edad , Análisis Multivariante , Periodo Perioperatorio , Complicaciones Posoperatorias/etiología , Probabilidad , Estudios Prospectivos , Análisis de Regresión , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: Pretreatment C-reactive protein (CRP) has been shown to be an independent prognostic factor for metastatic renal cell carcinoma (mRCC) treated with tyrosine kinase inhibitors (TKIs). We further evaluated the early response of CRP after the initiation of TKIs. METHODS: A total of 103 patients (80 men and 23 women) were treated with TKIs for mRCC from 2008-2013. Patients were divided into three groups according to their early CRP kinetics-patients whose baseline CRP levels were <10 mg/L (non-elevated), patients whose baseline CRP levels were ≥10 mg/L and had decreased by >20% at 4 weeks after the initiation of TKIs (early CRP responder), and the remaining patients (non-early CRP responder). The endpoints were progression-free survival (PFS) and overall survival (OS). RESULTS: The median follow-up period was 21 (interquartile range 10-34) months. The numbers of patients classified as non-elevated, early CRP responder, and non-early CRP responder were 62, 19, and 22, respectively. The 1-year PFS rates of patients in the non-elevated, early CRP responder, and non-early CRP responder groups were 50, 23, and 9.7%, respectively (p < 0.001). The 1-year OS rates of patients in these three groups were 79, 62, and 36%, respectively (p < 0.001). In multivariate analysis, the early CRP kinetics assessment was a significant independent factor for PFS and OS. CONCLUSIONS: Early CRP response at 4 weeks is predictive of survival for patients with mRCC treated with TKI.
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Proteína C-Reactiva/metabolismo , Carcinoma de Células Renales/tratamiento farmacológico , Neoplasias Renales/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Anciano , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/sangre , Proteína C-Reactiva/análisis , Carcinoma de Células Renales/mortalidad , Carcinoma de Células Renales/patología , Supervivencia sin Enfermedad , Femenino , Humanos , Indoles/uso terapéutico , Neoplasias Renales/mortalidad , Neoplasias Renales/patología , Masculino , Persona de Mediana Edad , Niacinamida/análogos & derivados , Niacinamida/uso terapéutico , Compuestos de Fenilurea/uso terapéutico , Pronóstico , Pirroles/uso terapéutico , Sorafenib , Sunitinib , Resultado del TratamientoRESUMEN
BACKGROUND: Point prevalence surveys (PPSs) in Japanese hospitals have not yet been reported. The purpose of this pilot PPS study was to evaluate the epidemiology of health care-associated infections (HAIs) and antimicrobial use in a Japanese tertiary university hospital. METHODS: A 1-day, cross-sectional PPS was performed at a Japanese university hospital. Data on demographics, active HAIs, and antimicrobial use of all inpatients were collected using a data collection form. RESULTS: Of 841 patients, 85 (10.1%) had 90 active HAIs, and 308 patients (36.6%) were administered 494 antimicrobials. Among the 90 HAIs and 58 pathogens, the most frequent infection and isolated pathogen were pneumonia (20.0%) and Enterobacteriaceae (27.6%), respectively. Of the 118 antimicrobials used for treatment of HAIs, carbapenems were the most frequently administered category of antimicrobials (22.9%). In regard to antimicrobials for surgical prophylaxis, 37 of 119 (31.1%) were administered to patients on postoperative day 3 or later, and 48 of 119 (40.3%) were administered orally. CONCLUSIONS: The incidence of HAIs is higher than in other developed countries. The social and medical situation in Japan may affect patient demographics, active HAIs, and antimicrobial use. Multicenter PPSs are necessary to uncover the real epidemiology of HAIs and antimicrobial use in Japan.
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Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/epidemiología , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/epidemiología , Utilización de Medicamentos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacterias/clasificación , Bacterias/aislamiento & purificación , Niño , Preescolar , Estudios Transversales , Monitoreo Epidemiológico , Femenino , Hospitales Universitarios , Humanos , Incidencia , Lactante , Recién Nacido , Japón , Masculino , Persona de Mediana Edad , Proyectos Piloto , Centros de Atención Terciaria , Adulto JovenRESUMEN
A 58-year-old woman was referred to our hospital for Cushingoid features and diagnosed as adrenal Cushing's syndrome due to a right adrenocortical mass (60 × 55 mm). The mass was composed of three different tumors; the first one was homogeneously lipid-poor neoplasm measuring 20 × 13 mm located at the most dorsal region, the second one was heterogeneous and lipid-rich tumor containing multiple foci of calcification measuring 50 × 32 mm located at the central region, and the last one was heterogeneous harboring dilated and tortuous vessels and lipid-poor one measuring 35 × 18 mm at the most ventral region of the adrenal gland. A right adrenalectomy was subsequently performed by open surgery. Macroscopic and microscopic analyses revealed that all three tumors were adrenocortical adenomas; the first one represents a pigmented adrenocortical adenoma, the second one adrenocortical adenoma associated with degeneration, and the third one adrenocortical adenoma harboring extensive degeneration. Immunohistochemical analysis of the steroidogenic enzymes also revealed that all of the tumors had the capacity of synthesizing cortisol. This is a very rare case of Cushing's syndrome caused by multiple adrenocortical adenomas including a pigmented adenoma. Immunohistochemical analysis of steroidogenic enzymes contributed to understanding of steroidogenesis in each of these three different adrenocortical adenomas in this case.
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Neoplasias de la Corteza Suprarrenal/complicaciones , Neoplasias de la Corteza Suprarrenal/patología , Adenoma Corticosuprarrenal/complicaciones , Adenoma Corticosuprarrenal/patología , Síndrome de Cushing/etiología , Biomarcadores de Tumor/análisis , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana EdadRESUMEN
OBJECTIVES: To investigate longitudinal changes in renal function after radical nephrectomy, and to explore risk factors of postoperative severe renal impairment in a Japanese multicenter cohort. METHODS: The present retrospective study included 701 patients who had no metastasis, end-stage kidney disease or bilateral kidney cancer, who underwent radical nephrectomy and who were followed up for at least 1 year. The longitudinal change in postoperative renal function during a 10-year follow-up period was evaluated according to the presence or absence of potential risk factors including greater age, chronic kidney disease, hypertension, diabetes mellitus and cardiovascular disease. A slope of annual change in estimated glomerular filtration rate was analyzed using a linear mixed model. Associations between the potential risk factors and a >50% estimated glomerular filtration rate decrease were evaluated using a multivariate Cox regression model. RESULTS: Overall, the postoperative estimated glomerular filtration rate recovered over time with a significant positive slope of 0.34 mL/min/1.73 m(2)/year. Renal function did not tend to recover in patients with chronic kidney disease, hypertension, diabetes mellitus or cardiovascular disease. The multivariate analysis showed that greater age and diabetes mellitus were independent risk factors for severe renal impairment. CONCLUSIONS: Overall, patients who had deteriorated renal function immediately after radical nephrectomy recovered over time. However, patients with chronic kidney disease, hypertension, diabetes mellitus and cardiovascular disease did not tend to recover renal function postoperatively. Greater age and diabetes mellitus were independent risk factors for a >50% decrease in estimated glomerular filtration rate.
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Tasa de Filtración Glomerular , Neoplasias Renales/cirugía , Riñón/fisiopatología , Riñón/cirugía , Nefrectomía/efectos adversos , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/epidemiología , Estudios de Cohortes , Comorbilidad , Creatinina/sangre , Diabetes Mellitus/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Hipertensión/epidemiología , Japón/epidemiología , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Nefrectomía/métodos , Periodo Posoperatorio , Recuperación de la Función , Insuficiencia Renal/etiología , Estudios Retrospectivos , Factores de RiesgoRESUMEN
We evaluated the significance of dietary instruction (DI) for patients who are going on a low iodine diet (LID) as a preparation for remnant tissue ablation for thyroid cancer. DI was done by a dietarian using a dedicated handbook we have developed. To assess the effect of LID on depleting body iodine, urinary iodine concentration (UIC) in patients with post-surgical papillary thyroid cancer was measured twice, before and after LID. UIC on the day of radioiodine administration was compared with radioiodine uptake (RU) in the remnant tissue. Additionally, the association between clinical and lifestyle-related features of patients and the outcome of LID were investigated. A questionnaire survey was conducted to determine whether the DI helped patients go on LID. The mean value of UIC after the one-week LID was decreased to about 15% of the baseline value. There was a significant inverse correlation between UIC and RU (r= -0.694). Age and UIC before the start of LID were linked to successful outcome of LID. In the questionnaire survey, 84% of the participants answered that the handbook helped them go on a LID. Likewise, 80% answered that they could manage their LID without using the boil-in-the-bag low iodine food. LID successfully decreased UIC in patients undergoing remnant tissue ablation. DI by a dietitian may make a practice of LID easier.
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OBJECTIVES: To develop and validate predictive models for postoperative estimated glomerular filtration rate and risk of chronic kidney disease after radical nephrectomy in Japanese patients. METHODS: The present retrospective study included a development cohort of 209 patients without preoperative chronic kidney disease who underwent radical nephrectomy between 1994 and 2008, and were followed up for longer than 3 years, and a validation cohort of 144 similar such patients. Univariate and multivariate linear regression or logistic regression analyses were carried out to identify the independent predictors of estimated glomerular filtration rate or chronic kidney disease 3 years after radical nephrectomy. Incorporating all independent predictors, predictive models for postoperative renal function were developed and externally validated. RESULTS: Age, the presence of diabetes mellitus, and preoperative estimated glomerular filtration rate were independent predictors of both postoperative estimated glomerular filtration rate and chronic kidney disease. A formula for predicting the postoperative estimated glomerular filtration rate and a nomogram for predicting the risk of postoperative chronic kidney disease were developed. The adjusted R(2) of the formula and area under the receiver operating characteristic curves of the nomogram were 0.446 and 0.865 in the development cohort, and 0.396 and 0.787 in the validation cohort, respectively. CONCLUSIONS: We developed and validated novel predictive models for the postoperative renal function 3 years after radical nephrectomy in Japanese patients.
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Tasa de Filtración Glomerular , Riñón/fisiología , Modelos Estadísticos , Nefrectomía , Adulto , Anciano , Anciano de 80 o más Años , Pueblo Asiatico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nefrectomía/métodos , Complicaciones Posoperatorias/epidemiología , Pronóstico , Insuficiencia Renal Crónica/epidemiología , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVE: The management of lower urinary tract symptoms that persist after radical prostatectomy remains to be established. We investigated whether an alpha1-blocker, naftopidil, improves LUTS in patients >or=1 year after radical prostatectomy. METHODS: A total of 29 male patients received 25 mg/day of naftopidil for the first week, then 75 mg/day for 4 weeks. The frequency-volume chart, international prostate symptom score and quality of life index (QOL) were examined before and at the end of the 5-week administration in all subjects. RESULTS: Total international prostate symptom score (I-PSS) and I-PSS subtotals associated with voiding symptoms and storage symptoms were significantly decreased at 5 weeks compared with baseline (P < 0.001 each). QOL index was significantly improved with naftopidil for 5 weeks (P < 0.001). From analyses of the frequency-volume chart, mean and maximum volume/void were significantly increased (P < 0.05 each). CONCLUSION: Lower urinary tract symptoms detected in patients >or=1 year after radical prostatectomy were markedly improved with administration of naftopidil at 75 mg/day. These symptoms could represent a novel target for medical treatment by improved understanding of the symptom pathology in the near future.
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Antagonistas Adrenérgicos alfa/uso terapéutico , Naftalenos/uso terapéutico , Piperazinas/uso terapéutico , Prostatectomía/métodos , Neoplasias de la Próstata/cirugía , Calidad de Vida , Trastornos Urinarios/tratamiento farmacológico , Antagonistas Adrenérgicos alfa/efectos adversos , Anciano , Anciano de 80 o más Años , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Estudios de Seguimiento , Humanos , Masculino , Naftalenos/efectos adversos , Satisfacción del Paciente , Piperazinas/efectos adversos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/tratamiento farmacológico , Prostatectomía/efectos adversos , Neoplasias de la Próstata/patología , Medición de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del Tratamiento , Trastornos Urinarios/etiología , UrodinámicaRESUMEN
Two types of sperm are produced in the silkworm, Bombyx mori. Nucleate eupyrene sperm is an ordinary sperm that contributes to fertilization, while anucleate apyrene sperm is considered to play important roles in assisting eupyrene sperm. At the very late stage of spermatogenesis, a phenomenon called "peristaltic squeezing" occurs in both types of sperm, whereby cytoplasm of the eupyrene and nuclei of the apyrene sperm are discarded from the posterior end, forming matured sperm. In this study, rhodamine-phalloidin staining for actin was applied to sperm bundles. Before the start of peristaltic squeezing, actin filament networks are spread on the cyst cells and constrictions by the networks appear in several places of the bundles. Actin particles, which are later recognized as circlets, are localized within the bundles. Squeezing action by the networks occurs from the anterior region and transfers toward the posterior, eliminating cytoplasm together with circlets from the posterior end. It seems that actin filaments contribute to the peristaltic squeezing of the sperm bundles in Bombyx mori.
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Citoesqueleto de Actina/metabolismo , Bombyx/metabolismo , Movimiento Celular/fisiología , Espermatogénesis/fisiología , Espermatozoides/citología , Espermatozoides/metabolismo , Citoesqueleto de Actina/ultraestructura , Animales , Bombyx/anatomía & histología , Bombyx/crecimiento & desarrollo , Diferenciación Celular/fisiología , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Citoplasma/metabolismo , Citoplasma/ultraestructura , Masculino , Faloidina , RodaminasRESUMEN
We isolated four W chromosome-derived bacterial artificial chromosome (W-BAC) clones from Bombyx mori BAC libraries by the polymerase chain reaction and used them as probes for fluorescence in situ hybridization (FISH) on chromosome preparations from B. mori females. All four W-BAC probes surprisingly highlighted the whole wild-type W sex chromosome and also identified the entire original W-chromosomal region in W chromosome-autosome translocation mutants. This is the first successful identification of a single chromosome by means of BAC-FISH in species with holokinetic chromosomes. Genomic in situ hybridization (GISH) by using female-derived genomic probes highlighted the W chromosome in a similar chromosome-painting manner. Besides the W, hybridization signals of W-BAC probes also occurred in telomeric and/or subtelomeric regions of the autosomes. These signals coincided well with those of female genomic probes except one additional GISH signal that was observed in a large heterochromatin block of one autosome pair. Our results support the opinion that the B. mori W chromosome accumulated transposable elements and other repetitive sequences that also occur, but scattered, elsewhere in the respective genome.
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Bombyx/genética , Cromosomas Artificiales Bacterianos/genética , Sondas de ADN , Aberraciones Cromosómicas Sexuales , Cromosomas Sexuales , Animales , Femenino , Biblioteca de Genes , Genoma , Hibridación Fluorescente in Situ/métodos , Cariotipificación , MasculinoRESUMEN
Bombyx spermatogonia are bipotential, producing nucleate eupyrene sperm and anucleate apyrene sperm. An in vitro cultivation of spermatocysts of Bombyx mori from spermatocytes to matured sperm was established. The present experiment made clear that: (i) spermatocysts must be isolated; (ii) constant shaking at 45 r.p.m. was necessary; and (iii) the addition of Bombyx hemolymph (BH) was indispensable for successful cultivation. In the absence of BH, spermatogenesis proceeded normally for 2 or 3 days and, thereafter, spermatocytes and sperm bundles began to degenerate. The best results for normal eupyrene spermatogenesis were obtained when culture medium containing BH of the corresponding stage was used in every exchange of the medium at 72 h intervals. None or only a small number of apyrene sperm bundles was produced by this culture system when spermatocysts from larval testes were used, although eupyrene spermatogenesis proceeded normally to form matured, or squeezed, sperm bundles.
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Bombyx/fisiología , Espermatocitos/crecimiento & desarrollo , Espermatogénesis/fisiología , Animales , Técnicas de Cultivo de Célula/métodos , Masculino , Espermatocitos/citología , Espermatocitos/fisiología , Espermatozoides/citología , Espermatozoides/fisiologíaRESUMEN
Silkworm males produce dimorphic sperm, nucleate eupyrene sperm and anucleate apyrene sperm. Apyrene sperm have been speculated to have an assisting role in fertilisation. However, the coexistence of eupyrene and apyrene sperm in the testis and female reproductive organs has made it difficult to define the role of apyrene sperm. Polyploid males are highly sterile. Microscopic observation revealed that the elimination of eupyrene nuclei by peristaltic squeezing caused the sterility of polyploids. Heat-shock applied to pupae of Daizo males (DH) also induced high sterility due to the lack of normal apyrene sperm. When eupyrene sperm of sterile DH males and apyrene sperm of sterile polyploid males were mixed by double copulation, a remarkable increase in fertility of the double-mated females was observed. This finding strongly suggests that the apyrene sperm are indispensable in fertilisation of the silkworm and that polyploid apyrene sperm function as a substitute for diploid sperm. We established an experimental system in which we can separate the two types of sperm for further studies on their functions without chemical and/or mechanical treatments.
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Bombyx/fisiología , Diploidia , Poliploidía , Animales , Bombyx/genética , Cruzamientos Genéticos , Femenino , Fertilidad/genética , Masculino , Reproducción/fisiología , Espermatozoides/fisiologíaRESUMEN
Early embryonic mitosis of the silkworm, Bombyx mori, was morphologically studied in the normal eggs and in the eggs treated by low temperature (-10°C). The first embryonic mitosis is observed in the eggs at 120 to 150 minutes after deposition at 26°C. After egg and sperm pronuclei unite, a spindle is formed in each of the pronuclei independently. At metaphase and anaphase paternal and maternal chromosomes are in separate groups on a spindle (gonomeric) and karyogamy takes place at telophase when they reach the poles. The second embryonic mitosis is shown in the eggs at 180 to 210 minutes after deposition. The division of two nuclei is not synchronous in the silkworm, and the mitosis is not gonomeric. In the eggs treated by low temperature, spindle fibers are not observed at all at -10°C, and chromosomes, which form two deeply stained masses of irregular shape, are seen in the less stained area of spindle shape. When the eggs are returned to 26°C, some eggs go into normal gonomeric division, while some form two small and compact spindles, which seem to be derived from each of the pronuclei. It was observed that these compact spindles are able to continue mitosis.