RESUMEN
The purpose of our study is to develop a treatment procedure for humic substances (HS hereafter) and phosphate ion in wastewater and environmental water by percolation of the water through a constructed soil layer at the hydraulic loading of a few metres per day. In the present work, batch sorption tests were conducted for more than 80 samples of soil, sludge, mineral and organic materials in order to find good sorbents for fulvic acid (FA hereafter) and phosphate ion. The results showed that the sorption of FA was high for some charcoal, and apatite and goethite minerals. Comparatively high sorption of FA was found for some Andosols and volcanic ash soil. Significant sorption of phosphate ion, on the other hand, was found for various types of soil, sludge from water treatment plants and some waste materials. The linear isotherm was obtained for the sorption of FA to a charcoal, apatite and goethite minerals, and Andosols.
Asunto(s)
Sustancias Húmicas/análisis , Fosfatos/análisis , Suelo , Contaminantes del Agua/análisis , Purificación del Agua/métodos , Absorción , Benzopiranos/análisis , Carbono/química , Carbón Mineral/análisis , Estudios de Evaluación como Asunto , Compuestos de Hierro/química , Minerales/química , Compuestos Orgánicos , Fosfatos/química , Aguas del Alcantarillado/química , TermodinámicaRESUMEN
Presented in this paper are the results of a series of column experiments and a pilot scale test conducted to develop the treatment system of freshwater and wastewater by their percolation through soil and the other materials at the rate of a few metres per day. Materials that had high ability to sorb fulvic acid (FA hereafter) and phosphate ion were selected based on the results of the batch sorption tests and were processed into beads before subjecting them to the column test. The results of the column experiment suggested that the reagents added to increase the strength of the beads reduced the sorption of FA, thus causing the early breakthrough of the FA injected into the column. Less effect from the bead processing was observed for the removal of phosphate ion. Pilot scale test showed that the removal of particulate fraction of phosphorus differed among the materials used. The bead processing technique that can ensure the high water permeability while maintaining the sorption capacity of the material was required for further development of the treatment system.
Asunto(s)
Suelo , Contaminantes del Agua/aislamiento & purificación , Purificación del Agua/métodos , Benzopiranos/aislamiento & purificación , Estudios de Evaluación como Asunto , Filtración , Aguas del Alcantarillado/química , Termodinámica , Eliminación de Residuos LíquidosRESUMEN
It is well established that the Clock gene is essential for expressing circadian activity rhythms in mammals under constant darkness. The Clock gene product is a positive component of a molecular feedback loop which is assumed to generate the circadian rhythm. On the other hand, chronic treatment of methamphetamine (MAP) induces locomotor activity rhythm in a circadian domain, which is independent of the suprachiasmatic nucleus (SCN) and is driven by a pacemaker outside the SCN. However, it is not known whether the pacemaker outside the SCN possesses a similar molecular mechanism to that in the SCN. Here we show that MAP restores locomotor activity rhythm in arrhythmic homozygous Clock mutant (Clock/Clock) mice under constant darkness. This result indicates that the Clock mutation does not affect the MAP-induced locomotor rhythm.
Asunto(s)
Relojes Biológicos/efectos de los fármacos , Encéfalo/efectos de los fármacos , Ritmo Circadiano/efectos de los fármacos , Metanfetamina/farmacología , Actividad Motora/efectos de los fármacos , Mutación/efectos de los fármacos , Transactivadores/efectos de los fármacos , Animales , Relojes Biológicos/genética , Encéfalo/metabolismo , Proteínas CLOCK , Ritmo Circadiano/genética , Ratones , Ratones Mutantes , Actividad Motora/fisiología , Mutación/fisiología , Transactivadores/genética , Transactivadores/metabolismoRESUMEN
Regional specificities of the dorsal and ventral regions of the suprachiasmatic nucleus (SCN) were examined to elucidate the structure of multioscillator circadian organization. The circadian rhythms of arginine vasopressin (AVP) and vasoactive intestinal polypeptide (VIP) release, and of electrical activity of individual neurons were measured in an organotypic, static slice culture of the SCN obtained from neonatal rats. Five days after the start of culture, robust circadian rhythms were detected in AVP release with a peak located consistently at the middle of the original light phase, while the 24 h profiles of VIP release were either arrhythmic or rhythmic. In the latter case, a phase delay of 5-7 h was observed in the circadian peak from the AVP rhythm. Multi-channel, extracellular recording revealed that 51 (76.1%) out of 67 firing neurons, examined in the SCN, showed circadian rhythms in their firing rate. The percentage of rhythmic neurons was significantly larger in the dorsal (86.8%) than in the ventral (62.1%) region of the SCN, where the AVP and VIP containing neurons predominate, respectively. Twenty-seven percent of the firing rhythms were almost antiphasic from the majority of rhythms. There was no regional specificity in the distribution of the antiphasic rhythm. These findings, that the dorsal and ventral regions of the SCN both contain circadian pacemakers with different properties that regulate the AVP and VIP release separately, is probably due to differences in the number and, hence, the coupling strength of oscillating neurons.
Asunto(s)
Potenciales de Acción/fisiología , Arginina Vasopresina/metabolismo , Relojes Biológicos/fisiología , Ritmo Circadiano/fisiología , Neuronas/metabolismo , Núcleo Supraquiasmático/metabolismo , Péptido Intestinal Vasoactivo/metabolismo , Animales , Animales Recién Nacidos , Comunicación Celular/fisiología , Inmunohistoquímica , Neuronas/citología , Ratas , Ratas Wistar , Núcleo Supraquiasmático/citologíaRESUMEN
OBJECTIVES: The aim of this study was to examine the relationship between the monomers eluted from dentin-bonding systems and their cytotoxicities, and to investigate the biochemical effect of the monomers on tyrosine phosphorylation, especially relating to the cell growth activity, of L929 cells in vitro. METHODS: The primers, uncured or cured adhesives (3M and Kuraray) were tested to determine the cytotoxicity of confluent L929 cells cultured by Eagle's MEM medium supplemented with 10% FCS. The area of cells affected by the eluted monomers were evaluated with an image analyzer and the concentrations of monomers eluted into the medium were measured with high performance liquid chromatography (HPLC) after 24h incubation. The protein composition of the stimulated cells was compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tyrosine phosphorylation was detected by Western blot. RESULTS: The primer and uncured adhesives revealed variable cytotoxicities. 2-hydroxyethyl-methacrylate (HEMA) was the major component eluted from uncured primers and adhesives. Small amounts of triethylene glycol dimethacrylate (TEGDMA) were also detected from the uncured adhesives. The cytotoxicities of the adhesives decreased as photo activation time increased. The amount of monomers eluted from the cured adhesives was almost undetectable and did not reach a sufficient concentration to suppress cell viability or cell growth. The cytotoxicities of the primers and adhesives correlated well with the amounts of either HEMA or TEGDMA eluted. Moreover, a high concentration of HEMA (4 mg/ml medium) affected intracellular tyrosine phosphorylation, which is related to cellular activities. SIGNIFICANCE: Although the monomers present in dentin bonding resins are cytotoxic to L929 cells, the amount from cured bonding resin is very small and does not provide a cytotoxic dose. This data does however suggest that clinical exposure to the uncured primers and adhesives of dentin bonding resins should be minimized.
Asunto(s)
Recubrimientos Dentinarios/toxicidad , Fibroblastos/efectos de los fármacos , Proteínas Tirosina Fosfatasas/efectos de los fármacos , Piel/efectos de los fármacos , Tirosina/efectos de los fármacos , Adhesivos/toxicidad , Análisis de Varianza , Animales , Western Blotting , Recuento de Células , División Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Resinas Compuestas/toxicidad , Electroforesis en Gel de Poliacrilamida , Procesamiento de Imagen Asistido por Computador , Luz , Ensayo de Materiales , Metacrilatos/toxicidad , Ratones , Fosforilación , Polietilenglicoles/toxicidad , Ácidos Polimetacrílicos/toxicidad , Proteínas Tirosina Fosfatasas/análisis , Cementos de Resina/toxicidad , Piel/citología , Tirosina/análisisRESUMEN
Extracellular concentration of nitrite (NO2-), an oxidized product of nitric oxide (NO), was measured consecutively in the dorsal region of the rat suprachiasmatic nucleus (SCN) by means of in vivo microdialysis. The NO2- concentrations in the dialysates showed robust circadian rhythm under a 12:12 h light/dark cycle and were higher during the dark phase than during the light phase. When the rats were transferred to constant darkness, the 24 h rhythm of NO2- persisted without damping the amplitude. The NO2- level was significantly lowered by an injection of NO synthase inhibitor (NG-monomethyl-L-arginine, 10 mg/kg i.p.). These findings indicate that the daily fluctuation of NO2- in the dorsal region of the SCN, which represents endogenous rhythm of NO, is regulated independently of photic inputs into the SCN and may be related to the circadian clock functions.
Asunto(s)
Ritmo Circadiano/fisiología , Neuronas/metabolismo , Óxido Nítrico/metabolismo , Núcleo Supraquiasmático/metabolismo , Animales , Relojes Biológicos/fisiología , Espacio Extracelular/metabolismo , Masculino , Microdiálisis , Actividad Motora/fisiología , Neuronas/citología , Nitritos/metabolismo , Ratas , Ratas Sprague-Dawley , Núcleo Supraquiasmático/citologíaRESUMEN
Circadian firing rhythms of cultured rat suprachiasmatic nucleus were measured simultaneously from 4-8 neurons by using a multi-electrode dish and neuronal interactions were examined by a cross-correlation analysis of spontaneous action potentials. Functional connections were detected in the neuron pairs showing synchronized circadian firing rhythms, and when the connections were lost, firing rhythms were desynchronized. After the prolonged treatment with tetrodotoxin, cross-correlation and circadian rhythm synchronization were abolished concomitantly in most neuron pairs. Cellular mechanisms involving Na(+)-channel dependent communication are responsible for the synchronization of the circadian rhythms in individual suprachiasmatic nucleus (SCN) neurons.
Asunto(s)
Relojes Biológicos/fisiología , Neuronas/fisiología , Núcleo Supraquiasmático/fisiología , Transmisión Sináptica/fisiología , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Células Cultivadas , Ritmo Circadiano/efectos de los fármacos , Ritmo Circadiano/fisiología , Neuronas/citología , Neuronas/efectos de los fármacos , Ratas , Ratas Wistar , Tiempo de Reacción/efectos de los fármacos , Bloqueadores de los Canales de Sodio , Canales de Sodio/fisiología , Núcleo Supraquiasmático/citología , Transmisión Sináptica/efectos de los fármacos , Tetrodotoxina/farmacologíaRESUMEN
OBJECTIVE: The purpose of this pilot study was to gather preliminary data on father-infant dyads using the Nursing Child Assessment Satellite Training (NCAST) Teaching scale, a parent-infant interaction measure, to determine whether and how fathers score differently than mothers from normative samples. METHOD: Interactions between first-time father (N = 15) and their infants, 3 months to 6 months of age, during the instruction of an unfamiliar play activity were rated using the NCAST Teaching scale. Scores were compared both with a normative database (N = 2,123) of mother-infant dyads and with a subsample (n = 34) of the normative database to control for demographic variables, including the age, gender, and birth parity of the child and the age, education, marital status, and ethnicity of the parent. RESULTS: The fathers scored significantly lower on items related to fostering the infants' cognitive growth than the mothers in the normative database. However, the infants in this study provided clearer behavioral cues and were more responsive to their fathers than the infants in the normative sample. These findings were also true for the subsample comparison. The fathers also scored significantly lower than the normative subsample on items measuring their ability to foster the social and emotional growth of their infants. CONCLUSION: There may be important differences in the interactions of father-infant dyads compared with mother-infant dyads, but further research with a larger, more representative sample of fathers on this parent-infant interaction measure is warranted to support this. The development of normative scores for fathers and their infants is recommended to accurately interpret father-infant interactions when administering the NCAST Teaching scale.
Asunto(s)
Emociones , Relaciones Padre-Hijo , Conducta del Lactante , Adulto , Recolección de Datos , Femenino , Humanos , Recién Nacido , Masculino , Persona de Mediana Edad , Relaciones Madre-Hijo , Proyectos Piloto , Valores de ReferenciaRESUMEN
TdP is a serious complication of AV block. We report a case of complete AV block with QT prolongation who had bouts of TdP resistant to lidocaine and isoproterenol. Temporary pacing could not be performed, because insertion of a pacing lead triggered TdP that deteriorated into ventricular fibrillation. Nicorandil, a potassium channel opener, shortened the QT interval and abolished TdP. This may suggest that potassium channel opening drugs are clinically effective against TdP associated with bradycardia-dependent QT prolongation.
Asunto(s)
Antiarrítmicos/uso terapéutico , Bloqueo Cardíaco/complicaciones , Nicorandil/uso terapéutico , Canales de Potasio/efectos de los fármacos , Torsades de Pointes/tratamiento farmacológico , Anciano , Anestésicos Locales/uso terapéutico , Bradicardia/etiología , Cardiotónicos/uso terapéutico , Electrocardiografía/efectos de los fármacos , Femenino , Humanos , Isoproterenol/uso terapéutico , Lidocaína/uso terapéutico , Fibrilación Ventricular/etiologíaRESUMEN
Flecainide and pilsicainide, Class IC antiarrhythmic drugs with slow kinetics, were administered to a 64-year-old man experiencing ventricular tachycardia. Both drugs suppressed the arrhythmia, but caused ST segment elevation in leads II, III, and aVF. No evidence of ischemic heart disease was detected. Withdrawal of the drugs eliminated the ST change. Because these drugs frequently are used to treat tachyarrhythmias in patients who may present with chest pain, this rare ECG manifestation of Class IC drugs should be recognized to avoid misdiagnosis of acute inferior myocardial infarction.
Asunto(s)
Antiarrítmicos/efectos adversos , Electrocardiografía , Flecainida/efectos adversos , Corazón/efectos de los fármacos , Corazón/fisiopatología , Lidocaína/análogos & derivados , Isquemia Miocárdica/fisiopatología , Antiarrítmicos/uso terapéutico , Diagnóstico Diferencial , Quimioterapia Combinada , Flecainida/uso terapéutico , Humanos , Lidocaína/efectos adversos , Lidocaína/uso terapéutico , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico , Taquicardia Ventricular/tratamiento farmacológicoRESUMEN
A 49-year-old male was admitted to our hospital because of chest pain. The pain occurred simultaneously with tachycardia-dependent left bundle branch block (LBBB) during exercise-stress and atropine-stress electrocardiogram (ECG) and on 24-h ambulatory ECG monitoring. Myocardial perfusion and metabolic scintigraphy with Tl-201 and I-123 BMIPP, respectively, showed no evidence of ischemia. Coronary arteriography revealed no atherosclerotic lesions, but did show a fistula between three major coronary arteries and the main pulmonary artery. The left-to-right shunt was undetectably small. Administration of diltiazem and metoprolol suppressed LBBB by attenuating the heart rate response to exercise, and reduced the chest pain. Therefore we presume that the exertional chest pain was not caused by myocardial ischemia but by the tachycardia-dependent LBBB. Coronary artery-pulmonary artery fistula is the most common type of coronary artery fistulae found incidentally in adulthood. Involvement of three major coronary branches is, however, rare. The case is discussed with a review of the literature.
Asunto(s)
Bloqueo de Rama/etiología , Dolor en el Pecho/etiología , Anomalías de los Vasos Coronarios/complicaciones , Arteria Pulmonar/anomalías , Taquicardia/etiología , Fístula Vascular/complicaciones , Anomalías de los Vasos Coronarios/diagnóstico por imagen , Prueba de Esfuerzo , Humanos , Masculino , Persona de Mediana Edad , Arteria Pulmonar/diagnóstico por imagen , Radiografía , Fístula Vascular/diagnóstico por imagenRESUMEN
Various oligosaccharides from hyaluronic acid, which have glucuronic acid or N- acetylglucosamine at the nonreducing terminal, were prepared by digestion with a combination of testicular hyaluronidase and beta-glucuronidase. These oligo saccharides were analyzed by negative-mode ion-spray mass spectrometry (MS) with an atmospheric pressure ion source. Introduction of collisionally activated dissociation tandem mass spectrometry (CAD-MS/MS) produced ions derived from cleavage of the glycosidic bonds, allowing the structure to be analyzed. The CAD-MS/MS spectrum showed an intense and characteristic fragment ion at m/z 193 for oligosaccharides having glucuronic acid at the nonreducing terminal. On the other hand, this ion was not observed in the spectra of oligosaccharides having N- acetylglucosamine at the nonreducing terminal. Therefore, the fragmentation pattern revealed by CAD-MS/MS provides useful information for distinguishing glucuronic acid and N- acetylglucosamine at the nonreducing terminal of oligosaccharides derived from hyaluronic acid and other glycosaminoglycans. This ion-spray CAD-MS/MS technique was also applied successfully to the characterization of glycosaminoglycans reconstructed by glycotechnology.
Asunto(s)
Glicosaminoglicanos/química , Ácido Hialurónico/química , Oligosacáridos/química , Animales , Secuencia de Carbohidratos , Carbohidratos/análisis , Bovinos , Escherichia coli/enzimología , Glucuronidasa/metabolismo , Humanos , Ácido Hialurónico/aislamiento & purificación , Hialuronoglucosaminidasa/metabolismo , Masculino , Espectrometría de Masas/métodos , Datos de Secuencia Molecular , Oligosacáridos/aislamiento & purificación , Espectrometría de Masa de Ion Secundario/métodos , Testículo/enzimología , Cordón Umbilical/químicaRESUMEN
The activities of sucrase, total alkaline phosphatase (total ALP) and intestinal-type alkaline phosphatase (I-ALP) were assayed in gastric carcinomas and in their surrounding mucosae from 57 patients with advanced cancers, and the localization of sucrase in 203 carcinomas, including 86 early cancers, was examined immunohistochemically using polyclonal anti-sucrase antibody. All three enzymes were active in the 57 carcinomas as well as in their surrounding mucosae, but the levels were fairly low as compared to those in normal jejunum mucosa. A considerable part of the total ALP activity in tumor specimens was assumed to be due to I-ALP itself. Increased sucrase and I-ALP were found with greater depth of invasion by undifferentiated-type carcinomas. The pattern of immunohistochemical localization of sucrase in the 203 carcinomas also clearly indicated increased expression with greater depth of invasion even in differentiated-type carcinomas.
Asunto(s)
Adenocarcinoma/enzimología , Fosfatasa Alcalina/biosíntesis , Neoplasias Gástricas/enzimología , Sacarasa/biosíntesis , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Fosfatasa Alcalina/metabolismo , Progresión de la Enfermedad , Femenino , Humanos , Inmunohistoquímica , Intestinos/enzimología , Masculino , Persona de Mediana Edad , Fenotipo , Neoplasias Gástricas/patología , Sacarasa/metabolismoRESUMEN
In this study the small-intestine phenotype in rat colonic tumors was investigated in terms of sucrase and intestinal-type alkaline phosphatase (I-ALP) activity. F344 rats were given intraperitoneal injections of methylazoxymethanol acetate at a dose level of 25 mg/kg body weight once a week for 8 weeks and were killed 40 weeks after the first injection. Sucrase and I-ALP activities in proximal and distal colon adenocarcinomas were significantly higher than those in the normal colon epithelium. In the jejunum, by contrast, normal tissue had significantly higher levels than tumors. Immunohistochemical staining of I-ALP was also strong in striated cell borders of colon adenocarcinoma cells. These data suggest that, whereas absorptive cells of the small intestine lose their own traits with tumor development, colonocytes acquire phenotypic features of the small intestine. Intestinal enzymes associated with the striated-cell border, such as sucrase and I-ALP, may be useful markers for malignant phenotypic expression in colonocytes.
Asunto(s)
Adenocarcinoma/enzimología , Fosfatasa Alcalina/metabolismo , Neoplasias Colorrectales/enzimología , Acetato de Metilazoximetanol/farmacología , Sacarasa/metabolismo , Adenocarcinoma/patología , Animales , Neoplasias Colorrectales/patología , Inmunohistoquímica , Mucosa Intestinal/enzimología , Fenotipo , Ratas , Ratas Endogámicas F344RESUMEN
Comparison of the slope of progressive isocapnic hypoxia obtained with and without prior O2 exposure (termed + and -O2 runs, respectively) placed our subjects into two groups. Positive responders had a significantly lower slope in -O2 runs compared with similar runs in negative responders, but they also improved hypoxic ventilatory response (HVR) significantly after O2 exposure. Negative responders had a high -O2 slope that did not alter significantly after O2 exposure. We conclude that ambient air hypoxic depression is active in positive responders who are O2 sensitive.
Asunto(s)
Hipoxia/inducido químicamente , Hipoxia/diagnóstico , Oxígeno/efectos adversos , Adulto , Femenino , Humanos , Masculino , Oxígeno/administración & dosificación , Método Simple CiegoRESUMEN
We measured heart rate (HR), stroke volume (SV), systemic arterial blood pressure (BP), and mean arterial pressure (MAP) in 7 healthy volunteers in response to face immersion in water with concomitant breath-holding at different lung volumes. The subjects were at rest in the prone position. During breath-holding at total lung capacity (TLC), baseline HR (70 to 75 beats/min) fell by 10% within fractions of a second, both in the control preimmersion state when the head was surrounded by room air, and when it was immersed in water of 33 degrees C. This response was associated with rises in MAP and in SV. Immersion of the face in 10 degrees C water while breath-holding, was associated with a strong, negative chronotropic effect (22% fall in HR), which developed within 10 s. Breath-holding at functional residual capacity (FRC) reduced HR substantially only in 10 degrees C water, and in contrast to that at TLC, the response was slowly developing with a latency of 10-15 s. All these reductions in HR were significant and accompanied by increases in BP and MAP. The strong, negative chronotropic effect of cold water was typically linked to a rise in SV. The study identified two temporal components of HR reduction to face immersion: a fast parasympathetic response dependent on the input from the high pressure baroreceptors, and a late response mediated, in all likelihood, by sympathetic efferent activity. Facial receptors sensitive to cold seem to be vital in the largest responses observed. The fast response to breath-holding with the face in water of neutral temperature was equal to that in air. Thus "diving bradycardia" is in fact a basic survival response independent of water.
Asunto(s)
Frío , Inmersión , Reflejo/fisiología , Células Receptoras Sensoriales/fisiología , Adulto , Presión Sanguínea/fisiología , Bradicardia/etiología , Bradicardia/fisiopatología , Buceo , Cara , Frecuencia Cardíaca/fisiología , Humanos , Respiración/fisiología , Volumen Sistólico/fisiología , Capacidad Pulmonar TotalRESUMEN
Chemical and non-chemical contributions to breath-holding time (BHT) were directly determined by using a visual analog scale (VAS). These values were compared with those indirectly calculated from the method proposed by Godfrey and Campbell (1968). The magnitude of non-chemical factor at low PCO2 in our study was substantially less than the one obtained by the above investigators. We conclude that Godfrey and Campbell's model postulating linear augmentation of non-chemical sensation is inappropriate to explain dyspnea profile during breath-holding.
Asunto(s)
Disnea/fisiopatología , Respiración/fisiología , Biometría , Dióxido de Carbono , Femenino , Humanos , Masculino , Modelos Biológicos , Intercambio Gaseoso Pulmonar/fisiologíaRESUMEN
Combined effect of cis-DDP (II) (CDDP), a streptococcal preparation (OK-432) and systemic hyperthermia on ascites tumor in mice was studied. Tumor cells were of a syngeneic cloned cell line FMA3 which was derived from Furth's mastocytoma. When number of cells transplanted into the abdominal cavity was at 10(5), a single i.p. injection of CDDP at a dose of 4 mg/kg was effective to increase the mean survival time by a factor of 1.6. OK-432 given i.p. at a dose of 5 KE/kg on every two days between day 2 and day 10 after transplantation decreased the mean survival times. Even when it was used in combination with CDDP, enhancement of the effect of CDDP was not statistically significant. However, by the factorial analysis of the all data obtained in the experiments carried out with tumor cells of the number of 10(2), 10(3), 10(4) and 10(5), enhancement of the effect of CDDP by OK-432 was significant. Systemic hyperthermia of the core-body temperature of 40 degrees C was not effective when used alone, and did not enhance the effect of CDDP. However, combined use of it and OK-432 significantly enhanced the effect of CDDP.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Hipertermia Inducida , Sarcoma de Mastocitos/terapia , Neoplasias Peritoneales/terapia , Animales , Cisplatino/administración & dosificación , Terapia Combinada , Masculino , Ratones , Ratones Endogámicos , Picibanil/administración & dosificaciónRESUMEN
Effects of microwave-induced whole-body hyperthermia (WBH) on the mouse kidney were examined histologically for acute and late effects up to 150 days after WBH treatment at 43.5 degrees C (rectal temperature) for 20 min or 42 degrees C for 40 min. As a whole the damage could be divided into two types. One was the damage to distorted epithelial cells in the subcapsular region. This lesion was common in most animals, possibly caused by direct hyperthermic effect of microwave. The other was general renal atrophy accompanied with aqueous or protein-rich cysts due to a chain of physiological reactions of the whole body to WBH. The first reaction was characterized by general stasis of the blood stream in all parts of the kidney, which resulted in acute ischemia of some tissues. This was seen immediately by dilatation of the renal and interlobular veins as well as the bundles of capillaries in the medulla region. The subsequent event was rather specific cell necrosis of distal and collecting tubular epithelium as compared to proximal tubules. The cell destruction induced cell proliferation of the proximal tubular epithelia after two days. Later on, in accord with the recovery of the blood circulation, the proliferated cells were carried away into the lumen, these processes then resulting in obstruction of tubules through formation of protein casts in the lumen. The block incidentally led to the destruction of nephrons. The degenerated area sometimes consisted of aqueous or protein-rich cysts of various sizes after 7 to 30 days. Thereafter these cysts degenerated, decreasing in both number and size. Thus irreversible atrophy of the kidney developed after WBH.
Asunto(s)
Lesión Renal Aguda/etiología , Hipertermia Inducida/efectos adversos , Isquemia/etiología , Necrosis Tubular Aguda/etiología , Riñón/patología , Enfermedad Aguda , Animales , Atrofia , Isquemia/patología , Riñón/irrigación sanguínea , Necrosis Tubular Aguda/patología , Túbulos Renales Colectores , Túbulos Renales Distales , Ratones , Ratones EndogámicosRESUMEN
Circulatory and ventilatory responses to lower body negative pressure (LBNP) were simultaneously investigated in 8 healthy men before, during, and after the application of -20, -40, and -60 mmHg pressure. Minute ventilation (VE) decreased during LBNP due to a fall in respiratory frequency with sustained tidal volume. The cardiac output (Q) was reduced in proportion to the applied LBNP exposure, while VE decreased to almost the same level at all LBNP applications. In spite of decreased VE, end-tidal PO2 and PCO2 were increased and decreased, respectively, indicating a relative alveolar hyperventilation. The ventilation equivalent for O2 (VE/VO2) increased, while the cardiac output equivalent for O2 (Q/VO2) decreased. The relation between VE/VO2 and Q/VO2 showed a significant negative correlation (r = -0.93, p less than 0.01). The veno-arterial CO2 concentration difference (CvCO2--CaCO2) increased with LBNP, due to a fall in CaCO2 with constant CvCO2. The constant CvCO2 indicated a constant tissue acid-base balance. These observations suggest the existence of a ventilatory mechanism improving the efficiency of respiration in order to compensate for the sustained LBNP depression of Q at a given gas exchange.