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1.
BMC Gastroenterol ; 22(1): 160, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35365084

RESUMEN

BACKGROUND: Non-traumatic hemoperitoneum was a rare event with the risk of sudden death. Spontaneous rupture of hepatocellular carcinoma is the most intuitive diagnosis when hemoperitoneum occurs in cirrhotic patients who are not regularly followed up. However, other etiologies of hemoperitoneum, such as intra-abdominal varix rupture, should be kept in mind. CASE PRESENTATION: A 44-year-old man with alcoholic liver cirrhosis, Child-Pugh B was sent to our emergency department (ED) because of recurrent abdominal pain and hypovolemic shock. He had similar symptoms one month ago and was diagnosed as hepatocellular carcinoma (HCC) rupture with hemoperitoneum, therefore he underwent trans-arterial embolization (TAE). However, the follow-up magnetic resonance imaging (MRI) showed less possibility of hepatocellular carcinoma. Contrast enhanced abdominal computed tomography (CT) showed possible umbilical vein contrast agent extravasation. Exploratory laparotomy confirmed the diagnosis of rupture umbilical varix with hemoperitoneum. CONCLUSION: Although umbilical varix rupture is a rare cause of hemoperitoneum, it should be kept in mind in cirrhotic patients with unexplained hemoperitoneum.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Várices , Adulto , Carcinoma Hepatocelular/complicaciones , Hemoperitoneo/diagnóstico por imagen , Hemoperitoneo/etiología , Humanos , Neoplasias Hepáticas/complicaciones , Masculino , Rotura Espontánea/complicaciones , Rotura Espontánea/diagnóstico por imagen , Várices/complicaciones , Várices/diagnóstico por imagen
2.
Artículo en Zh | MEDLINE | ID: mdl-35785902

RESUMEN

Objective: To investigate the occupational damage to workers exposed to chromate in a steel plant. Methods: In January 2021, a retrospective analysis was used to select 850 workers exposed to chromate (observation group) and 598 workers not exposed to chromate (control group) in a steel plant in Shandong Province from 2016 to 2017 as the investigation. We collected their occupational-related information, blood routine, fasting blood sugar, nasal lesions, skin lesions, chest X-rays and other inspection results, compared the differences in the abnormal detection rate of the two groups of respondents, and analyzed the occupational hazards of chromium workers. Results: Incidence of nasal damage, skin lesion, up-regulation of ALT (Alanine aminotransferase), abnormal chest radiograph, abnormal serum biochemical index, and abnormal serum glucose level were observed higher in the exposed group than those in the control group (χ(2)=125.69, 12.25, 5.82, 10.37, 10.46, 20.66, P=0.000, 0.000, 0.016, 0.001, 0.001, 0.000). Among the symptoms, the incidence of erythra, nasal septum deviation, nasal mucosal congestion, nasal mucosal erosion and rhinitis were more frequent than those in the control group (χ(2)=101.54, 4.07, 13.20, 32.05, P=0.000, 0.044, 0.000, 0.000). There was no significant increase in the incidence of work type, age, length of work and the area of nasal mucosa erosion in the observation group compared with the control table, and the difference was not statistically significant (χ(2)=5.31、0.42、0.28, P=0.505, 0.662, 0.871) . Conclusion: Occupational hazards of long-term exposure to chromate cannot be ignored. Attention should be paid to strengthening occupational protection and health education of workers exposed to chromium, and increasing their attention.


Asunto(s)
Enfermedades Nasales , Exposición Profesional , Cromatos/análisis , Cromatos/toxicidad , Cromo , Humanos , Exposición Profesional/efectos adversos , Exposición Profesional/análisis , Estudios Retrospectivos , Acero
3.
Zhonghua Yu Fang Yi Xue Za Zhi ; 53(6): 559-564, 2019 Jun 06.
Artículo en Zh | MEDLINE | ID: mdl-31177750

RESUMEN

Objective: To investigate the relationship between the magnesium intake and patterns of diary and the risk of type 2 diabetes in Harbin residents. Methods: On April 2010, 24 communities in 7 districts of Harbin were selected as research sites using multi-stage stratified random cluster sampling method. A total of 9 734 residents aged 20-74 years was investigated using general questionnaire survey, dietary survey and biochemical indicators test. A total of 9 376 subjects were included in the study. Factor analysis was used to analyze dietary patterns. According to the quartile of dietary magnesium intake, the subjects were divided into four groups, from Q(1) to Q(4) group. The multivariate logistic regression model was used to analyze the relationship between dietary magnesium intake and the risk of type 2 diabetes within different dietary patterns. Results: A total of 998 subjects with type 2 diabetes were screened. The median age of the diabetic group and the non-diabetic group were 54.8 and 50.8, respectively, and the males accounted for 43.4% (2 896 cases) and 34.6% (433 cases), respectively. The magnesium intake median (P(25), P(75)) of two groups was 336.36 (257.31, 440.65) and 339.50 (264.51, 443.78) mg/d. Four dietary patterns were identified as western dietary mode, savvy dietary mode, traditional dietary mode, and staple food mode. In the western dietary model, the Q(4) group had a higher risk of type 2 diabetes than Q(1) group, with an OR (95%CI) value of 1.56 (1.06 to 2.32). However, in the savvy diet mode, compared with the Q(1) group, the risk of diabetes in the Q(4) group was lower, and the OR (95%CI) value was 0.61 (0.37 to 0.96). There was no statistically significant association between dietary magnesium intake and the risk of type 2 diabetes without considering dietary patterns (P>0.05). Conclusion: Dietary magnesium intake has a different relationship with the risk of type 2 diabetes within different dietary patterns.


Asunto(s)
Diabetes Mellitus Tipo 2 , Dieta , Magnesio , Adulto , Anciano , China/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Adulto Joven
4.
Artículo en Zh | MEDLINE | ID: mdl-31177700

RESUMEN

Occupational chromium rhinopathy is chronic nasal damage caused by chromic anhydride, chromate and dichromate 6-valent chromium compounds. In 2016, 700 people who were exposed to chromium slag in steel plant were checked out. 24 people were found to have nasal injuries. The expert group confirmed 1 case of occupational severe chromium rhinosis and 23 cases of occupational mild chromium rhinosis.There was no significant difference in the incidence, type of work and duration of injury among 24 patients (P>0.05) . Active measures should be taken to prevent chromium rhinopathy and the technological process should be reformed. Occupational health education and occupational health monitoring should be strengthened to avoid exposure of chromium and its compounds through nose and respiratory tract, and to reduce or eliminate the occurrence of chromium rhinosis.


Asunto(s)
Cromo , Enfermedades Nasales , Exposición Profesional , Cromatos , Cromo/envenenamiento , Humanos , Enfermedades Nasales/inducido químicamente , Sistema Respiratorio
5.
Dis Esophagus ; 29(4): 326-32, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-25716873

RESUMEN

The study aims to report the operative outcomes of robot-assisted thoracoscopic esophagectomy (RATE) with extensive mediastinal lymphadenectomy (ML) for intrathoracic esophageal cancer. We analyzed a prospective database of 114 consecutive patients who underwent RATE with lymph node dissection along recurrent laryngeal nerve (RLN) followed by cervical esophagogastrostomy. The study included 104 men with a mean age of 63.1 ± 0.8 years. Of these, 110 (96.5%) had squamous cell carcinoma, and the location of the tumor was upper esophagus in 7 (6.1%), middle in 62 (54.4%), and lower in 45 (39.5%). Preoperative concurrent chemoradiation was performed in 15 patients (13.2%). All but one patient underwent successful RATE, and R0 resection was achieved in 111 patients (97.4%). Extended ML and total ML were performed in 24 (21.1%) and 90 (78.9%) patients, respectively. Total operation time was 419.6 ± 7.9 minutes, and robot console time was 206.6 ± 5.2 minutes. The mean number of total, mediastinal, and RLN nodes was 43.5 ± 1.4, 24.5 ± 1.0, and 9.7 ± 0.7, respectively. The most common complication was RLN palsy (30, 26.3%), followed by anastomotic leakage (17, 14.9%) and pulmonary complications (11, 9.6%). Median hospital stay was 16 days, and 90-day mortality was observed in three patients (2.5%). On multivariate analysis, preoperative concurrent chemoradiation was a risk factor for pulmonary complications (odds ratio 7.42, 95% confidence interval 1.91-28.8, P = 0.004). RATE with extensive ML could be performed safely with acceptable postoperative outcomes. Long-term survival data should be followed in the future to verify the oncological outcome of the procedure.


Asunto(s)
Neoplasias Esofágicas , Esofagectomía , Escisión del Ganglio Linfático , Ganglios Linfáticos , Procedimientos Quirúrgicos Robotizados , Toracoscopía , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Neoplasias Esofágicas/mortalidad , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/cirugía , Esofagectomía/efectos adversos , Esofagectomía/métodos , Femenino , Humanos , Escisión del Ganglio Linfático/efectos adversos , Escisión del Ganglio Linfático/métodos , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía , Metástasis Linfática , Masculino , Mediastino , Persona de Mediana Edad , Tempo Operativo , Evaluación de Procesos y Resultados en Atención de Salud , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , República de Corea/epidemiología , Factores de Riesgo , Procedimientos Quirúrgicos Robotizados/efectos adversos , Procedimientos Quirúrgicos Robotizados/métodos , Toracoscopía/efectos adversos , Toracoscopía/métodos
6.
Arch Toxicol ; 86(5): 741-52, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22349056

RESUMEN

Polyphyllin D (PD) is a potent anticancer agent isolated from a traditional medicinal herb Paris polyphylla that has been used in China for many years to treat cancer. PD is not a substrate of p-glycoprotein, and it can bypass the multi-drug resistance in cancer cell line R-HepG2. However, the effect of PD on the induction of cell death in human erythrocytes remains unknown. Given that PD is a small molecule that can depolarize the mitochondrial membrane potential and release apoptosis-inducing factor (AIF) in isolated mitochondria, we hypothesized that the apoptogenic effect of PD in human erythrocytes devoid of mitochondria would be minimal. This study therefore tried to evaluate the in vitro effect of PD on hemolysis and apoptosis in human erythrocytes. Apoptosis in human red blood cells (RBCs), also known as eryptosis or erythroptosis, after PD treatment was determined by flow cytometry and confocal microscopy for the phosphatidyl-serine externalization and other apoptosis feature events. False to our prediction, PD caused hemolysis and eryptosis/erythroptosis in human RBCs. Mechanistically, elevation in the cytosolic Ca²âº ion level seems to be a key but not the only mediator in the PD-mediated eryptosis/erythroptosis because depletion of the external Ca²âº could not eliminate the PD effect. Also, PD was able to permeabilize the membrane of RBC ghosts in a way similar to digitonin. Taken together, we report here for the first time the toxicity of PD in human RBCs as well as its underlying mechanism for the hemolysis and eryptosis/erythroptosis.


Asunto(s)
Apoptosis/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Diosgenina/análogos & derivados , Eritrocitos/efectos de los fármacos , Calcio/metabolismo , Caspasa 3/metabolismo , Tamaño de la Célula/efectos de los fármacos , Células Cultivadas , Citosol/efectos de los fármacos , Citosol/metabolismo , Diosgenina/farmacología , Diosgenina/toxicidad , Eritrocitos/metabolismo , Eritrocitos/patología , Humanos , Membranas Mitocondriales/efectos de los fármacos , Saponinas
7.
J Neurophysiol ; 103(1): 278-89, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19889847

RESUMEN

In humans, hand performance has evolved from a crude multidigit grasp to skilled individuated finger movements. However, control of the fingers is not completely independent. Although musculotendinous factors can limit independent movements, constraints in supraspinal control are more important. Most previous studies examined either flexion or extension of the digits. We studied differences in voluntary force production by the five digits, in both flexion and extension tasks. Eleven healthy subjects were instructed either to maximally flex or extend their digits, in all single- and multidigit combinations. They received visual feedback of total force produced by "instructed" digits and had to ignore "noninstructed" digits. Despite attempts to maximally flex or extend instructed digits, subjects rarely generated their "maximal" force, resulting in a "force deficit," and produced forces with noninstructed digits ("enslavement"). Subjects performed differently in flexion and extension tasks. Enslavement was greater in extension than in flexion tasks (P = 0.019), whereas the force deficit in multidigit tasks was smaller in extension (P = 0.035). The difference between flexion and extension in the relationships between the enslavement and force deficit suggests a difference in balance of spillover of neural drive to agonists acting on neighboring digits and focal neural drive to antagonist muscles. An increase in drive to antagonists would lead to more individualized movements. The pattern of force production matches the daily use of the digits. These results reveal a neural control system that preferentially lifts fingers together by extension but allows an individual digit to flex so that the finger pads can explore and grasp.


Asunto(s)
Dedos , Actividad Motora , Desempeño Psicomotor , Pulgar , Adulto , Análisis de Varianza , Fenómenos Biomecánicos , Retroalimentación Sensorial , Femenino , Humanos , Masculino , Análisis y Desempeño de Tareas , Torsión Mecánica , Percepción Visual
8.
Eur Rev Med Pharmacol Sci ; 24(11): 6046-6054, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32572919

RESUMEN

OBJECTIVE: To elucidate the role of microRNA-34c-5p (miRNA-34c-5p) in the progression of hepatocellular carcinoma (HCC) and the indicated mechanism. PATIENTS AND METHODS: Relative levels of miRNA-34c-5p and FAM83A in HCC tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Their influences on clinical features in HCC patients were analyzed. Kaplan-Meier method was introduced for assessing the relationship between miRNA-34c-5p and overall survival in HCC. After overexpression of miRNA-34c-5p in HepG2 and HB611 cells, we detected proliferative, migratory and invasive abilities by cell counting kit-8 (CCK-8) and transwell assay. The interaction between miRNA-34c-5p and FAM83A was explored by Dual-Luciferase reporter assay. Finally, their co-regulation on HCC cell phenotypes was examined. RESULTS: MiRNA-34c-5p was downregulated in HCC tissues, especially stage III+IV cases. Its level was correlated to tumor size, tumor number and TNM staging in HCC. Overexpression of miRNA-34c-5p inhibited proliferative, migratory and invasive abilities in HepG2 and HB611 cells. In addition, miRNA-34c-5p targeted on FAM83A and negatively regulated its level. Overexpression of FAM83A could reverse the inhibitory effects of miRNA-34c-5p on malignant phenotypes of HCC cells. CONCLUSIONS: By negatively regulating FAM83A level, miRNA-34c-5p alleviates the progression of HCC.


Asunto(s)
Carcinoma Hepatocelular/metabolismo , Progresión de la Enfermedad , Neoplasias Hepáticas/metabolismo , MicroARNs/metabolismo , Proteínas de Neoplasias/metabolismo , Carcinoma Hepatocelular/patología , Células Cultivadas , Femenino , Humanos , Neoplasias Hepáticas/patología , Masculino , MicroARNs/genética , Persona de Mediana Edad , Proteínas de Neoplasias/genética
9.
Science ; 193(4250): 314-7, 1976 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-17745726

RESUMEN

A high-efficiency power cycle is proposed in which molecular hydrogen gas is used as a working fluid in a regenerative closed Brayton cycle. The hydrogen gas is compressed by an absorption-desorption cycle on metal hydride (FeTiH(x)) beds. Low-temperature solar or geothermal heat (temperature about 100 degrees C) is used for the compression process, and high-temperature fossil fuel or nuclear heat (temperature about 700 degrees C) supplies the expansion work in the turbine. Typically, about 90 percent of the high-temperature heat input is converted to electricity, while about 3 kilowatts of low-temperature heat is required per kilowatt of electrical output.

10.
Cancer Res ; 48(22): 6379-83, 1988 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-3052802

RESUMEN

Cyst fluid from women with gross cystic breast disease was found to contain protease activity when assayed against [14C]albumin. At least six different proteases were detected when the fluid was fractionated by a combination of S-300 Sephacel, hydroxylapatite, and DEAE-Sephacel chromatographic techniques. The distribution of the proteases appeared to be related to the ionic composition of the fluids. A major protease component, found in both high Na and high K fluids, was isolated. It showed chymotryptic cleavage characteristics against the beta-chain of insulin. It was partially inhibited by alpha 2-macroglobulin, N-tosyl-L-phenylalanine chloromethyl ketone, and benzamidine but not by leupeptin, pepstatin, N-tosyl-L-lysine chloromethyl ketone, or alpha 1-protease inhibitor. The protease has an apparent molecular weight of 110,000 with Mr 24,000 subunits. This protease may be identical or closely associated with Haagensen's GCDFP-24 progesterone binding protein which was isolated in a similar manner. An imbalance between protease and protease inhibitors in cyst fluid may account for gross cyst formation and may be involved in the tumorigenic process. The accumulation of poorly diffusible peptide fragments, as a result of protease activity, would increase the oncotic pressure leading to enlargement of the cyst cavity as water enters to reestablish osmotic equilibrium.


Asunto(s)
Enfermedad Fibroquística de la Mama/enzimología , Péptido Hidrolasas/aislamiento & purificación , Femenino , Humanos , Peso Molecular , Péptido Hidrolasas/fisiología , Albúmina Sérica/análisis
11.
J Comp Neurol ; 347(2): 233-48, 1994 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-7814666

RESUMEN

Neurogenesis occurs in adult song birds, which suggests that neurons born after hatching may contribute to histogenesis and plasticity of the avian brain. However, little is known about the overall contribution to the mature brain of neurons born in juveniles and adults, and how this process affects different regions of the avian brain. In fact, studies of the histogenesis of the avian forebrain have made the classical assumption that neuronal birth ends before hatching. Here we determined the contribution of neurons born before and after hatching to different regions throughout the adult canary brain. Male canaries were injected with [3H]-thymidine at different times during embryonic, juvenile, and adult life. The position of labeled neurons was mapped in parasagittal brain sections. Because all birds were killed as adults, results indicate the time of birth of neurons that survived to adulthood in different structures of the avian brain. Injection at embryonic day (E) 5 or E9 resulted in labeled neurons in all regions of the neuroaxis. The vast majority of neurons outside of the telencephalon were born before E9. One exception was a discrete region in the dorsal thalamus, a part of the song-control circuit, where neurons continued to be born after E9. Most regions of the telencephalon had a high proportion of its neurons labeled by the embryonic injections. In particular, archistriatum, anterior neostriatum, and the hippocampus had most of their neurons labeled before hatching. This indicates that many of the telencephalic neurons born in the embryo are long lived and are not replaced by other neurons that continue to be added to the telencephalon after hatching. Neurons labeled by [3H]-thymidine injections after hatching were restricted to the telencephalon and contributed importantly to many regions. In particular, the avian striatum (lobus parolfactorius, LPO) received a large number of its neurons during the first 20 days of life, but continued to incorporate new neurons throughout juvenile and adult life. Neurons continued to be added to the telencephalon of adults (even in 4-year-old birds). The distribution of labeled neurons after [3H]-thymidine injections in adults was similar to that observed in latter stages of juvenile development. The contribution of neurons born at different ages from embryonic development to adulthood varied among different anatomical subdivisions of the canary brain. this could, in part, explain differences in the cytoarchitecture and plasticity between brain regions. Neurogenesis after hatching may allow the modification of selected brain circuits as the bird matures and ages.


Asunto(s)
Mapeo Encefálico , Canarios/fisiología , Neuronas/fisiología , Vocalización Animal/fisiología , Animales , Canarios/embriología , Canarios/crecimiento & desarrollo , Supervivencia Celular/fisiología , Cuerpo Estriado/fisiología , Embrión no Mamífero/citología , Hipocampo/fisiología , Masculino , Plasticidad Neuronal/fisiología , Neuronas/citología , Telencéfalo/fisiología , Núcleos Talámicos/fisiología , Factores de Tiempo
12.
Ann N Y Acad Sci ; 586: 198-203, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2113367

RESUMEN

The precise origin of breast cyst fluid remains obscure. Molina has presented evidence that type II cysts (high Na/K ratio) may be transudative, that is, partly derived from plasma elements which enter through gap junctions, while Type I cysts (high K/Na ratio) are primarily secretory. In transudative cysts, plasma protease inhibitors may be present, but the balance between protease and its inhibitors may fluctuate as a result of as yet undetermined circumstances. An imbalance between the protease activity of cyst fluid and its inhibitors may be involved in the pathogenesis of breast gross cystic disease. Accumulation of protein fragments with resistant bonds would produce an elevated oncotic pressure causing a shift of fluid into the cyst capsule. Albumin is a good substrate for the protease, which may account for its low concentration in cyst fluid. The major protease fraction closely corresponds to the progesterone binding protein (GCDFP-24) described by Haagensen. Affinity columns containing aprotinin or benzamidine ligands retain the protease which can then be eluted with 0.5 M NaCl. The HD1 protease and progesterone binding protein are either tightly complexed or are the same protein. Cyst fluid is a complex mixture of biomolecules. If the progesterone binding protein is a protease, many questions must be answered concerning the influence of cyst fluid steroids, lipids, anions, and cations on enzyme action. Determination of the amino acid sequence of HD1 may help elucidate the source of the enzyme and its relationship to other tissue proteases. Human plasma contains inhibitors of this protease activity. When pooled, dialyzed plasma was mixed with pooled, dialyzed cyst fluid, the ratio of plasma/cyst fluid at which all activity was inhibited was 6/1. A comparison of the rate of cleavage of three 14C-protein substrates shows that cyst fluid proteases cleave in a characteristic manner, distinct from either trypsin or calpain. A simple method for semiquantitative estimation of protease activity in cyst fluid is described which utilizes prestained Coomassie blue-albumin containing agarose gel plates. All cyst fluids tested had protease activity but showed variability in their ability to cleave 14C-albumin by a factor of 4. There is much direct and indirect evidence that proteases are involved in the cancer process. In view of the higher than normal incidence of breast cancer in women who have had gross cystic breast disease, the possibility exists that an imbalance between these proteases and their inhibitors is somehow involved.


Asunto(s)
Exudados y Transudados/enzimología , Enfermedad Fibroquística de la Mama/enzimología , Péptido Hidrolasas/metabolismo , Femenino , Humanos , Inmunodifusión , Péptido Hidrolasas/análisis , Inhibidores de Proteasas/sangre
13.
Ann Otol Rhinol Laryngol ; 88(2 Pt 1): 178-82, 1979.
Artículo en Inglés | MEDLINE | ID: mdl-109028

RESUMEN

Combined therapy, consisting of 5000 rads delivered in five weeks by total laryngectomy +/- radical neck dissection, was compared with treatment by irradiation (6000-7000 rads) with surgical salvage when clinically possible for radiation failure. Patients were categorized according to site of primary cancer (glottic, supraglottic and pyriform sinus) and staged (T, N, M). Survival was equally good in the two programs for glottic and supraglottic lesions, N0 or N1. The combined treatment program was judged superior for supraglottic and pyriform sinus lesions, N2 or N3.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Hipofaringe , Neoplasias Laríngeas/radioterapia , Neoplasias Faríngeas/radioterapia , Cuidados Preoperatorios , Adulto , Anciano , Carcinoma de Células Escamosas/cirugía , Femenino , Glotis , Humanos , Neoplasias Laríngeas/cirugía , Laringectomía , Masculino , Persona de Mediana Edad , Disección del Cuello , Recurrencia Local de Neoplasia , Neoplasias Faríngeas/cirugía , Dosificación Radioterapéutica , Radioterapia de Alta Energía
14.
Acta Otolaryngol ; 115(2): 173-7, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7610798

RESUMEN

We used the IL088 Otodynamic Analyzer system to study click-evoked otoacoustic emissions (CEOAEs) in 30 healthy guinea pigs. The animals were anesthetized and patterns of the CEOAEs were evaluated before manipution, after the tympanic bulla was opened, and after formation of a microfistula on the basal turn of the cochlea. The animals then were divided into three pressure loading groups (10, 20, and 30 cm H2O). CEOAEs were recorded with a capillary manometer at pretest, 5, 10, 20, 30, 45, and 60 min after perilymphatic pressure loading to the basal turn of cochlea, and 10 and 20 min after pressure unloading. As perilymphatic pressure increased, all three pressure groups showed maximum decreases in both echo response and reproducibility 5 min after pressure loading. In the 10 cm H2O pressure group, emissions recovered 10 min after pressure loading, and this tendency continued. However, in the 20 and 30 cm H2O pressure groups, no recovery of emissions was seen throughout the 60 min observation period, except for emissions after pressure unloading. The results suggest that the echo response and reproducibility may be sensitive indicators of cochlear function and perilymphatic pressure regulation capacity.


Asunto(s)
Estimulación Acústica , Cóclea/fisiología , Cobayas , Perilinfa/fisiología , Animales
15.
Acta Otolaryngol ; 120(2): 146-50, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11603760

RESUMEN

Cisplatin ototoxicity is known to involve mainly the organ of Corti. Outer hair cells (OHCs). especially in the basal turn, are preferentially involved. One possible mechanism of ototoxicity might be alteration of the antioxidant system causing an increase in free radicals. It has been demonstrated that heat shock proteins (HSPs), which are believed to protect cells by dissolving and refolding misfolded or denatured protein are induced by various form of stress. HSP is also demonstrated to be induced by free radicals. The purpose of this study was to evaluate HSP 72 induction in cochlea following cisplatin injection in the animal model. Sprague-Dawley (SD) rats were injected intraperitoneally with normal saline as control or cisplatin at a dose of 5, 10 or 20 mg/kg. Cochleae were harvested 1, 3, 6 and 12 h after injection and compared with those of controls. Immunocytochemical study with surface preparation and Western blotting were performed to investigate the expression of HSP 72. Auditory brainstem response (ABR) was also recorded to assess functional change according to the dosage of cisplatin and duration after injection. In the 5 and 10 mg/kg groups, immunostaining for HSP 72 in the OHCs reached a plateau level at 3 h, which was maintained until 12 h after injection. The amount of immunoreactive OHCs in the 20 mg/kg group was smaller than those in 5 and 10 mg/kg groups and declined after 6 h. The bands for HSP 72 became less intense as the cisplatin dosage increased from 5 to 10 and 20 mg/kg in Western blotting. The change in ABR threshold was small in the 5 and 10 mg/kg groups and a marked change in threshold was observed in the 20 mg/kg group. Detection of HSP 72 after cisplatin injection could confirm the OHCs as one of the major injured cells in the cochlea. With a lethal dosage of cisplatin (20 mg/kg), HSP 72 expression was less prominent and declined after 6 h.


Asunto(s)
Supervivencia Celular/efectos de los fármacos , Cisplatino/toxicidad , Células Ciliadas Auditivas Externas/efectos de los fármacos , Proteínas de Choque Térmico/metabolismo , Órgano Espiral/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Radicales Libres , Proteínas del Choque Térmico HSP72 , Células Ciliadas Auditivas Externas/patología , Masculino , Órgano Espiral/patología , Ratas , Ratas Sprague-Dawley
20.
J Physiol ; 583(Pt 3): 1145-54, 2007 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-17656436

RESUMEN

The uncommonly good proprioceptive performance of the long flexor of the thumb, flexor pollicis longus (FPL), may add significantly to human manual dexterity. We investigated the forces produced by FPL single motor units during a weak static grip involving all digits by spike-triggered averaging from single motor units, and by averaging from twitches produced by intramuscular stimulation. Nine adult subjects were studied. The forces produced at each digit were used to assess how forces produced in FPL are distributed to the fingers. Most FPL motor units produced very low forces on the thumb and were positively correlated with the muscle force at recruitment. Activity in FPL motor units commonly loaded the index finger (42/55 units), but less commonly the other fingers (P < 0.001). On average, these motor units produced small but significant loading forces on the index finger ( approximately 5.3% of their force on the thumb) with the same time-to-peak force as the thumb ( approximately 50 ms), but had no significant effect on other fingers. However, intramuscular stimulation within FPL did not produce significant forces in any finger. Coherence at 2-10 Hz between the thumb and index finger force was twice that for the other finger forces and the coherence to the non-index fingers was not altered when the index finger did not participate in the grasp. These results indicate that, within the long-term coordinated forces of all digits during grasping, FPL motor units generate forces highly focused on the thumb with minimal peripheral transfer to the fingers and that there is a small but inflexible neural coupling to the flexors of the index finger.


Asunto(s)
Fuerza de la Mano/fisiología , Neuronas Motoras/fisiología , Pulgar/inervación , Pulgar/fisiología , Soporte de Peso/fisiología , Adulto , Electromiografía , Femenino , Dedos/inervación , Dedos/fisiología , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Propiocepción/fisiología
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