RESUMEN
The effect of exercise on gastric mucosal energy status has not been fully elucidated. The aim of this study was to evaluate the impact of submaximal cycling on gastric mucosal energy balance and its relationship to changes in systemic energy status. Ten healthy volunteers (age 20-40 years) were investigated at rest (BL), during 30 min of submaximal exercise (E) on bicycle ergometry and during the 30 min after the completion of cycling. Gastric mucosal PCO(2) ( P(gm)CO(2)) was measured by air tonometry at 10-min intervals and the gastric mucosal-arterial PCO(2) difference ( PCO(2)gap) was calculated. Hemodynamics, arterial blood gases, lactate and pyruvate were also measured. PCO(2)gap significantly increased throughout exercise [BL: 0.2 kPa (median), -0.1-0.6 kPa (25th-75th percentiles); E(10 min): 1.0 kPa, 0.8-1.7 kPa; E(20 min): 1.35 kPa, 0.8-1.8 kPa; E(30 min): 1.5 kPa, 0.9-2.0 kPa]. The early changes in PCO(2)gap ( PCO(2)gap at E(10 min) minus PCO(2)gap at BL) correlated significantly and positively with corresponding changes in arterial lactate ( r(2)=0.58, P<0.05) and lactate-to-pyruvate ratio ( r(2)=0.72, P<0.05). On recovery, all metabolic parameters normalized within 30 min. We conclude that submaximal cycling in volunteers leads to the early derangement of gastric mucosal energy balance. The time course of PCO(2)gap parallels changes in systemic energy status.
Asunto(s)
Metabolismo Energético/fisiología , Ejercicio Físico/fisiología , Mucosa Gástrica/metabolismo , Adulto , Presión Sanguínea/fisiología , Dióxido de Carbono/sangre , Prueba de Esfuerzo , Mucosa Gástrica/irrigación sanguínea , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/metabolismo , Masculino , Ácido Pirúvico/metabolismo , Circulación Esplácnica/fisiologíaRESUMEN
Craniofacial deformities caused by therapeutic radiation-induced bone growth inhibition can occur in up to 100% of survivors of childhood head and neck cancers. The mechanism of radiation-induced craniofacial bone growth inhibition is poorly understood. The objective of this study is to establish a model of radiation-induced craniofacial bone growth inhibition to study the pathophysiology of radiation on growing membranous bone. Seven-week-old male New Zealand white rabbits were randomized into 4 groups (n = 10/group) and received a single dose of orthovoltage radiation (0, 15, 25, or 35 Gy) to the right orbital-zygomatic complex. Serial radiographs and computed tomography scans were performed for cephalometric analysis, bone volume, and bone density measurements until skeletal maturity at 21 weeks. Statistically significant ( P < 0.05) reductions in orbital-zygomatic complex linear bone growth, bone volume, and bone density were found after radiation with 25 or 35 Gy compared with nonirradiated control animals. A significant ( P < 0.05) decrease in orbital-zygomatic complex volume was noted after 15-Gy radiation but there were no significant effects on linear bone growth as assessed by cephalometric analysis at this dose. This study establishes the rabbit orbital-zygomatic complex as a suitable model for the study of radiation-induced craniofacial bone growth inhibition and will permit investigation into the underlying cellular and molecular basis of this injury.
Asunto(s)
Órbita/efectos de la radiación , Cigoma/efectos de la radiación , Análisis de Varianza , Animales , Densidad Ósea/efectos de la radiación , Cefalometría , Modelos Animales de Enfermedad , Relación Dosis-Respuesta en la Radiación , Procesamiento de Imagen Asistido por Computador , Masculino , Mandíbula/diagnóstico por imagen , Mandíbula/crecimiento & desarrollo , Mandíbula/efectos de la radiación , Hueso Occipital/diagnóstico por imagen , Hueso Occipital/crecimiento & desarrollo , Hueso Occipital/efectos de la radiación , Órbita/diagnóstico por imagen , Órbita/crecimiento & desarrollo , Hueso Paladar/diagnóstico por imagen , Hueso Paladar/crecimiento & desarrollo , Hueso Paladar/efectos de la radiación , Conejos , Dosis de Radiación , Traumatismos Experimentales por Radiación/fisiopatología , Distribución Aleatoria , Cráneo/diagnóstico por imagen , Cráneo/crecimiento & desarrollo , Cráneo/efectos de la radiación , Base del Cráneo/diagnóstico por imagen , Base del Cráneo/crecimiento & desarrollo , Base del Cráneo/efectos de la radiación , Estadística como Asunto , Tomografía Computarizada por Rayos X , Cigoma/diagnóstico por imagen , Cigoma/crecimiento & desarrolloRESUMEN
We have developed a non-invasive imaging tracer kinetic model for blood flow which takes into account the distribution of capillaries in tissue. Each individual capillary is assumed to follow the adiabatic tissue homogeneity model. The main strength of our new model is in its ability to quantify the functional distribution of capillaries by the standard deviation in the time taken by blood to pass through the tissue. We have applied our model to the human prostate and have tested two different types of distribution functions. Both distribution functions yielded very similar predictions for the various model parameters, and in particular for the standard deviation in transit time. Our motivation for developing this model is the fact that the capillary distribution in cancerous tissue is drastically different from in normal tissue. We believe that there is great potential for our model to be used as a prognostic tool in cancer treatment. For example, an accurate knowledge of the distribution in transit times might result in an accurate estimate of the degree of tumour hypoxia, which is crucial to the success of radiation therapy.
Asunto(s)
Capilares/anatomía & histología , Capilares/fisiología , Modelos Biológicos , Modelos Cardiovasculares , Próstata/irrigación sanguínea , Neoplasias de la Próstata/irrigación sanguínea , Neoplasias de la Próstata/radioterapia , Hipoxia de la Célula , Humanos , Cinética , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Radioterapia Asistida por Computador/métodos , Flujo Sanguíneo Regional , Reproducibilidad de los Resultados , Tomografía Computarizada por Rayos XRESUMEN
Thermoregulation in control subjects and cold-adapted winter swimmers was examined during 1 h of cold water immersion (13 C). It was found that the thermoregulatory functions of winter swimmers differ from those of non-cold-adapted subjects. As evident from the relationship between rectal temperature and the magnitude of cold thermogenesis, in controls a significant part of cold thermogenesis during the early phase of cooling was induced by changes in peripheral temperature input, while in the late phase of cooling it was the central temperature input which was mainly engaged in induction of cold thermogenesis. In winter swimmers the magnitude of cold thermogenesis was solely related to changes in rectal temperature, indicating the predominance of the central temperature input in activation of heat production mechanisms. The thermoregulatory threshold for induction of cold thermogenesis was lowered (by 0.34 C), but the apparent hypothalamic thermosensitivity was the same as in non-cold-adapted subjects. These differences are indicative of adaptation of thermoregulatory control centres. Additionally, the activity of thermoregulatory effectors was also changed. Shivering was induced later during cooling (after 40 min) in winter swimmers than in controls, which suggests an important participation of non-shivering thermogenesis in the early thermogenic response. Winter swimmers also showed bradycardia and a greater reduction in plasma volume during cooling. The data indirectly indicate restriction of heat loss from the body. Only a non-significant increase in quantity of subcutaneous fat was observed in winter swimmers. Thus, winter swimmers were able to survive a significantly greater temperature gradient between body and environment than non-cold-adapted subjects by modifying the sensory functions of hypothalamic thermoregulatory centres to lower heat loss and produce less heat during cold exposure. Additionally, the capacity of the total cold thermogenesis due to potentiation of non-shivering heat production was also increased. Heat produced due to thermogenic action of adrenaline may represent more than a quarter of the total cold thermogenesis. In conclusion, the data suggest that winter swimmers exhibit metabolic, hypothermic and insulative types of cold adaptation.
Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Catecolaminas/fisiología , Natación/fisiología , Adaptación Fisiológica/fisiología , Adulto , Presión Sanguínea/fisiología , Temperatura Corporal/fisiología , Frío , Epinefrina/sangre , Femenino , Frecuencia Cardíaca/fisiología , Hemodinámica/fisiología , Humanos , Masculino , Norepinefrina/sangre , Volumen Plasmático/fisiologíaRESUMEN
Based on their own experience with a large group of patients with thyroid cancers, the authors confirm the higher prevalence of differentiated thyroid cancers both papillary and follicular (1 : 3,5) in females, while the differences in anaplastic and medullary cancers are much less prominent. Survival of females in univariate studies is much higher in both papillary and follicular cancers compared to males, in multivariate studies these differences lose their significance and only in papillary cancers under the age of 40 years at diagnosis and in a subgroup of papillofollicular cancers the differences retain their significance. The authors therefore deduce that differences found in univariate studies are significantly influenced by other factors such as age at the diagnosis and the spread of disease at the diagnosis.
Asunto(s)
Neoplasias de la Tiroides/epidemiología , Adenocarcinoma Folicular/epidemiología , Adenocarcinoma Folicular/mortalidad , Adulto , Carcinoma/epidemiología , Carcinoma/mortalidad , Carcinoma Medular/epidemiología , Carcinoma Medular/mortalidad , Carcinoma Papilar/epidemiología , Carcinoma Papilar/mortalidad , República Checa/epidemiología , Femenino , Humanos , Masculino , Prevalencia , Factores Sexuales , Tasa de Supervivencia , Neoplasias de la Tiroides/mortalidadRESUMEN
The aim of this study was to investigate whether or not the human immune system can be activated by a noninfectious stimulus, thereby improving the physiological status of the individual. The effect of a single cold water immersion (14 degrees C for 1 h) on the immune system of athletic young men, monitored immediately after immersion, was minimal. With the continuation of the cold water immersions (three times a week for a duration of 6 weeks) a small, but significant, increase in the proportions of monocytes, lymphocytes with expressed IL2 receptors (CD25) and in plasma tumour necrosis factor alpha content was induced. An increase in the plasma concentrations of some acute phase proteins, such as haptoglobin and haemopexin, was also observed. After 6 weeks of repeated immersions a trend towards an increase in the plasma concentrations of IL6 and the amount of total T lymphocytes (CD3), T helper cells (CD4), T suppressor cells (CD8), activated T and B lymphocytes (HLA-DR) and a decrease in the plasma concentration of alpha 1-antitrypsin was observed. Concentrations of IL1 beta, neopterin, C-reactive protein, orosomucoid, ceruloplasmin, macroglobulin, immunoglobulins (IgG, IgM, IgA) and C3, C4 components of the complement, as well as the total number of erythrocytes, leucocytes, granulocytes and neutrophils showed no significant changes after the repeated cold water immersions. It was concluded that the stress-inducing noninfectious stimuli, such as repeated cold water immersions, which increased metabolic rate due to shivering the elevated blood concentrations of catecholamines, activated the immune system to a slight extent. The biological significance of the changes observed remains to be elucidated.
Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Frío , Sistema Inmunológico/fisiología , Adulto , Temperatura Corporal/fisiología , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Differentiated carcinoma of the thyroid gland is globally changing its character and occurrence frequency. METHODS: Retrospective analysis of patients sent to the Clinic of Nuclear Medicine in Prague, Motole in order to undergo the radioactive iodine therapy during the period from 1960 to 1993 in comparison to the set of patients of the 1950-1959 period. MAIN RESULTS: A conspicuous change took place in the proportion of papillary and follicular carcinomas. The previous predominance of follicular carcinoma has turned to the predominance of papillary carcinoma, the occurrence of which is increasing. The authors see the causes not only in introduction of iodidation which decreases the occurrence of more aggressive forms of differentiated carcinoma, but also in radioactive fall, as well as in the change of diagnostic procedures. CONCLUSIONS: The occurrence of differentiated carcinoma is so far increasing, but in the recent years the increase of more aggressive forms of the disease (follicular carcinoma) has ceased and an expressive increase of less aggressive papillary carcinoma is continuing. (Tab. 1, Ref. 14.).
Asunto(s)
Adenocarcinoma Folicular/epidemiología , Carcinoma Papilar/epidemiología , Neoplasias de la Tiroides/epidemiología , República Checa/epidemiología , HumanosRESUMEN
BACKGROUND: Repeated exposure to cold leads to a decline in the intensity of physiological defence reactions. In the complex of adaptational responses metabolic, thermogenic and insulation reactions predominate. The objective of the present investigation was to provide evidence of the predominating type of response of sportsmen exposed repeatedly to cold in an aqueous environment and to elucidate metabolic processes which serve to meet the energy demands of a certain type of adaptation to cold. METHODS AND RESULTS: The examination was made in a group of volunteers (men, mean age 21.0 +/- 1.8 years, height 1.80 +/- 0.04 m, body weight 77.0 +/- 3.1 kg, body fat 13.2 +/- 1.7%, anaerobic capacity expressed as maximum oxygen consumption 4.5 +/- 0.43 l.min-1). The cold acclimation programme involved immersion of the body into water 14 +/- 1 degree C 3 times a week for 1 month. During cold exposure the median body temperature before the acclimation programme dropped by 3.9 degrees C, after the acclimation programme by 4.1 degrees C. The total metabolic turnover after the programme declined by a 0.23 multiple of the metabolism at rest, at the end of the programme merely by a multiple of 0.07. During immersion the oxygen consumption doubled regardless of the stage of adaptation and an insignificant rise of non-esterified fatty acids occurred before the onset of the programme as well as after its termination. After the first exposure to cold a significant drop of the blood sugar was observed, while after the acclimation programme it increased insignificantly. The serum level of the thyroid stimulating hormone and triiodothyronine were affected only insignificantly by exposure to cold, the thyroxine level only at the borderline of significance before the onset of the acclimation programme. CONCLUSIONS: From values of the blood sugar level, respiratory quotient RQ, the non-esterified fatty acid level and body temperature at the periphery we may conclude that there is a restriction of the carbohydrate component as regards meeting energy demands of cold exposure before adaptation and a mixed type of meeting energy demands after termination of the cold acclimation programme.
Asunto(s)
Adaptación Fisiológica/fisiología , Frío , Adulto , Glucemia/análisis , Metabolismo Energético , Ácidos Grasos no Esterificados/sangre , Humanos , Masculino , Consumo de OxígenoRESUMEN
The primary metastatic melanoblastoma presented with macroscopic haematuria as a first sign is described. So far it is our first experience with such a type of tumor in lower urinary tract in ageing man. The references in literature are scarce on this subject.
Asunto(s)
Melanoma , Neoplasias de la Vejiga Urinaria , Anciano , Humanos , Masculino , Melanoma/patología , Melanoma/secundario , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
To characterize fluid and ion shifts during 5-weeks cold adaptation, 6 nonadapted volunteers underwent cold acclimation programme (CAP), consisted of 1 h head-out immersion in water 14 +/- 1 degrees C 3 times a week. Blood samples were analyzed before/after the immersion and in the first and in the last week of CAP. Urine was collected for 10 h before, during, and after immersion for 4 h. Plasma volume (PV) decreased during first immersion (-18%) and less after CAP (-12). Blood volume reduction was 8.5% before and 5.2% after the CAP. Mean corpuscular volume was not changed either after the cold exposition or after the cold adaptation. The concentration of serum proteins increased by 12.1% after first immersion and by 8.1% after the CAP. The changes in serum concentration of Na+, K+ and Cl- before and after the CAP were not significant. Urine flow increased by 102% after first immersion, and by 165% after CAP. Urinary excretion of Na+ increased by 167% and 283%, excretion of K+ by 222% and 362% during first immersion and after CAP, respectively. Serum concentration of aldosterone increased nonsignificantly (+30%) during immersion before CAP and it did not changed after CAP. After the cold adaptation we observed the reduction of PV decrease, and increased diuresis with higher excretions of cations.
Asunto(s)
Aclimatación , Volumen Sanguíneo , Frío , Electrólitos/metabolismo , Orina , Adulto , Proteínas Sanguíneas/análisis , Humanos , InmersiónRESUMEN
The authors present the case-history of a patient with a cystic retroperitoneal lymphangioma. Its diagnosis was established only by histological examination of the resected tissue. The authors draw attention to the symptomatology, diagnosis, therapy and discuss contemporary views regarding the cause of this disease.
Asunto(s)
Linfangioma Quístico , Neoplasias Retroperitoneales , Humanos , Linfangioma Quístico/diagnóstico , Linfangioma Quístico/terapia , Masculino , Persona de Mediana Edad , Neoplasias Retroperitoneales/diagnóstico , Neoplasias Retroperitoneales/terapiaRESUMEN
Losec (omeprazole) Astra Co. is a blocker of the proton pump of the parietal cell. It inhibits basal and stimulated HCl secretion. It is used for treatment of gastroduodenal ulcers, reflux oesophagitis and Zollinger Ellison's syndrome. In a group of 17 patients with duodenal ulcers the authors investigated the effect of omeprazole on (1) healing of duodenal ulcers and bulbitis after 2-4 weeks of therapy, (2) elimination of Helicobacter pylori in the antrum, (3) chronic antral gastritis. Ad 1. After two weeks of treatment the authors found that 5 of 17 chronic duodenal ulcers were healed in the remainder substantial regression was found. Four-week treatment led to healing of 16 from a total of 17 ulcers (P < 0.001), i. e. 94%. In subjects with ulcers and bulbitis (12 patients) the ulcer healed in 11 instances, in 7 patients residual bulbitis persisted. Ad 2. H. pylori was detected before treatment in 16 of 17 patients, after treatment only in 5 (P < 0.001). Ad 3. Chronic gastritis was recorded before treatment in all patients. Treatment reduced its activity and the presence of H. pylori.
Asunto(s)
Úlcera Duodenal/tratamiento farmacológico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Omeprazol/uso terapéutico , Úlcera Duodenal/microbiología , Úlcera Duodenal/patología , Femenino , Gastritis/tratamiento farmacológico , Gastritis/microbiología , Gastritis/patología , Infecciones por Helicobacter/patología , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Estómago/microbiologíaRESUMEN
Adipose tissue in the thyroid gland was observed in 7 biopsies and 2 autopsies: in 3 cases of solitary adenolipoma, 3 cases of multiple adenolipoma, 1 case of pure lipomatosis and 2 cases of lipomatosis with multiple adenolipomas combined with amyloidosis of lobules as well of adenomas in one bioptic case. Pathogenesis of this unusual phenomenon was discussed.
Asunto(s)
Adenoma/patología , Amiloidosis/patología , Lipomatosis/patología , Enfermedades de la Tiroides/patología , Neoplasias de la Tiroides/patología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Concentrations of selenium and rubidium in groups of subjects with hyperthyroidism, carcinomas, or adenomas and in controls were determined by neutron activation analysis with coirradiated inorganic standards and IAEA reference material. Se was decreased in all pathological groups with the greatest modification in thyroids with carcinomas. Rb was elevated in all pathological groups with the greatest increase in carcinomas as well. According to the literature, Se has a protective effect on carcinogenity as well as on biochemical pathways in thyroid cells. There are no data in the literature on the effects of Rb in those cells. On the grounds of the present results, it seems possible to use the trapping of Rb for diagnostic purposes in cases of pathologically altered thyroids.
Asunto(s)
Rubidio/análisis , Selenio/análisis , Enfermedades de la Tiroides/metabolismo , Glándula Tiroides/química , Adenoma/química , Adenoma/metabolismo , Adolescente , Adulto , Anciano , Carcinoma Papilar/química , Carcinoma Papilar/metabolismo , Femenino , Humanos , Hipertiroidismo/metabolismo , Masculino , Persona de Mediana Edad , Factores Sexuales , Enfermedades de la Tiroides/patología , Glándula Tiroides/metabolismo , Glándula Tiroides/patología , Neoplasias de la Tiroides/química , Neoplasias de la Tiroides/metabolismoRESUMEN
1. Extreme long-term endurance loads of great intensity lead during the recovery period to significant changes of the preejection period and Weissler's index. The cause of this change is most probably the reversibly impaired contractility of the heart muscle after fatigue of the left ventricle as a result of a certain degree of overburdening. 2. Systolic time intervals are suitable means for the dynamic follow-up of the performance of the left ventricle in subjects after sports performances.
Asunto(s)
Resistencia Física/fisiología , Sístole/fisiología , Humanos , Masculino , Volumen Sistólico/fisiologíaRESUMEN
The authors subjected to endoscopic examination 90 patients with duodenal ulcers. From each patient they collected a bioptic specimen of the gastric antrum and duodenal bulbus for microbiological and histological examination. They found that for detection of C. pylori the microscopic examination was most useful. The presence of C. pylori in the gastric antrum was detected in 87% of the subjects and in the duodenal bulb only in 48%. The difference is significant at the 0.01 level. To 43 patients of the group Ranitidine was administered. The ulcer was cured within 4 weeks in 35 subjects. Ranitidine did not affect the presence of C. pylori and antral gastritis. After cure of the ulcer the authors administered Tarivid to 10 patients with persisting C. pylori positivity. The presence of C. pylori and antral gastritis were not affected by this treatment.
Asunto(s)
Infecciones por Campylobacter/tratamiento farmacológico , Úlcera Duodenal/microbiología , Adulto , Campylobacter/aislamiento & purificación , Úlcera Duodenal/tratamiento farmacológico , Femenino , Gastritis/tratamiento farmacológico , Gastritis/microbiología , Humanos , Masculino , Persona de Mediana Edad , Ofloxacino/uso terapéutico , Ranitidina/uso terapéuticoRESUMEN
The authors present two cases where on the basis of the pilonidal sinus spinocellular carcinoma developed. Both patients were successfully operated. The first one has been for three years, the second one for eight months without relapse. From the paper ensues that cancerization of the pilonidal sinus must be considered a very serious complication and must be prevented by early surgery.
Asunto(s)
Carcinoma de Células Escamosas/complicaciones , Seno Pilonidal/complicaciones , Adulto , Anciano , Carcinoma de Células Escamosas/patología , Humanos , Masculino , Seno Pilonidal/patologíaAsunto(s)
Frío , Riñón/fisiología , Natación , Adulto , Análisis Químico de la Sangre , Humanos , Masculino , Proteinuria , Orina/análisisRESUMEN
Whenever we stand upright in apparent static equilibrium, we are, in fact, continuously making minor adjustments in order to maintain our balance. For each intervertebral joint, a point must exist at which all moments applied to the joint are continually and dynamically balanced. This point, known as the centre of reaction, is a mathematical invention necessary to perform analyses of spinal motion, but which need not be associated with any real anatomical structure. As the spine flexes and extends, this centre is expected to move; where it moves and the rationale for its motion is worthy of enquiry. In this paper, we propose that the centre of reaction remains confined to the nucleus of the disc, but only if one simple but crucial assumption is made; that the motion of the spine and control of its musculature maintain a minimum and equal stress at each intervertebral joint. This is a simple hypothesis which imposes a very specific relationship between lordosis and the centre of reaction. We investigate this relationship and its consequences on the teaching of lifting. The impossibility of designing experiments adequately to verify this hypothesis prevents in vivo verification, and, therefore, the model's verification must be made through the inferred consequences. For example, the capability of correctly predicting physiological responses of the musculoskeletal system is an indication of the validity of a model; however, this is not universally accepted. In this particular case, additional experimental data are available in the form of the locus of the centre of rotation of a vertebra vis-à-vis its lower neighbour as the spine flexes and extends. It is instructive to compare the predicted locus of the centre of reaction to experimentally determined locus of the centre of rotation; more than just coincidental similarities are found.