RESUMO
AIM: Activation of protein kinase C (PKC) is thought to play an important role in the pathogenesis of diabetic microvascular complications. PKC-beta is elevated in hyperglycaemic conditions, both in vivo and in vitro. In this study, pharmacological effects of a novel PKC-beta isoform selective inhibitor, JTT-010 ((2R)-3-(2-aminomethyl-2,3-dihydro-1H-3a-azacyclopenta(a)inden-8-yl)-4-phenylaminopyrrole-2,5-dione monomethanesulphonate), on diabetic neuropathy were examined. METHODS: PKC inhibitory activity of JTT-010 was evaluated with an enzyme assay. For the in vivo study, streptozotocin (STZ)-induced diabetic rats were treated with JTT-010 for 12 weeks and tail/sciatic nerve conduction velocity (NCV) evaluated. Hyper/hypoalgesia was evaluated using tail-flick and formalin tests. RESULTS: JTT-010 inhibited PKC-betaI and -betaII with IC50 values of 4.0 and 2.3 nm respectively. For other PKC isoforms, IC50 values were 54 nm or greater. In STZ-induced diabetic rats showing a reduction in tail/sciatic nerve conduction velocities, JTT-010 (0.3-3 mg/kg) ameliorated the reduction of these velocities. In a formalin test, STZ-induced diabetic rats had hyperalgesia in the first phase. JTT-010 reduced nociceptive response at doses of 0.1 mg/kg or higher. Furthermore, STZ-induced diabetic rats showed hypoalgesia in the second phase of the formalin test and tail-flick test. JTT-010 also ameliorates these symptoms at doses of 0.1 mg/kg or higher. CONCLUSIONS: These observations suggest that PKC-beta contributes not only to diabetic hyperalgesia, but also to hypoalgesia and also contributes to defects in NCV. PKC-beta inhibitor, JTT-010, may be beneficial in suppressing the development of diabetic nerve dysfunction, including hyperalgesia and hypoalgesia.
Assuntos
Diabetes Mellitus Experimental/complicações , Neuropatias Diabéticas/prevenção & controle , Hiperalgesia/prevenção & controle , Indanos/uso terapêutico , Proteína Quinase C/antagonistas & inibidores , Pirróis/uso terapêutico , Animais , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/fisiopatologia , Neuropatias Diabéticas/enzimologia , Neuropatias Diabéticas/fisiopatologia , Hiperalgesia/enzimologia , Hiperalgesia/fisiopatologia , Hipestesia/enzimologia , Hipestesia/fisiopatologia , Hipestesia/prevenção & controle , Indanos/farmacologia , Masculino , Condução Nervosa/efeitos dos fármacos , Proteína Quinase C/metabolismo , Proteína Quinase C/fisiologia , Proteína Quinase C beta , Pirróis/farmacologia , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/enzimologia , Nervo Isquiático/fisiopatologiaRESUMO
PURPOSE: An attenuated baroreflex response and orthostatic intolerance have been reported in endurance-trained male athletes; however, it is still unknown whether this occurs also in females. The purpose of the present study was to examine whether endurance exercise-trained women had a predisposition to orthostatic compromise, and if so, what causative factor(s) may induce orthostatic intolerance. METHODS: We studied cardiovascular and hormonal responses to graded lower body negative pressure (LBNP) (0 to -60 mm Hg) in 26 middle-distance female runners (18.6 +/- 0.1 yr) as the exercise-trained (ET) subjects and 23 age-matched untrained (UT) control subjects. On the basis of the occurrence of syncope episodes during LBNP, ET and UT subjects were further allocated to two groups; ET with presyncope (ET+syncope) and without presyncope (ET-syncope) and UT with presyncope (UT+syncope) and without presyncope (UT-syncope). RESULTS: Occurrence of presyncope episodes during LBNP was higher in ET (65.4%, P < 0.05) than that for UT (34.8%). Leg compliance was higher (P < 0.05) in ET than in UT. LBNP reduced stroke volume (SV) more (P < 0.05), increased heart rate (HR) higher (P < 0.05), and increased forearm vascular resistance (FVR) more in ET+syncope as compared with the other groups. Response of vasoactive hormones to LBNP was higher in ET+syncope (P < 0.05) than that of the other groups except for norepinephrine (NE); high in both ET+syncope and UT+syncope. The relationship between SV and NE, an index of sympathetic neuronal response, had no training-related changes during LBNP. CONCLUSION: We conclude that exercise-trained females have a high incidence of orthostatic intolerance during LBNP, with a greater reduction of SV independent of changes in baroreflex and neurohumoral function. A lower incidence of LBNP intolerance in UT may be accounted for by a lower reduction of SV during LBNP. An increase in leg compliance in the exercise-trained females may play an important role in inducing pronounced reduction of SV and hence the intolerance to LBNP.
Assuntos
Hipotensão Ortostática/fisiopatologia , Hipovolemia/fisiopatologia , Pressão Negativa da Região Corporal Inferior , Corrida/fisiologia , Síncope/fisiopatologia , Adolescente , Adulto , Barorreflexo/fisiologia , Feminino , Humanos , Hipotensão Ortostática/sangue , Hipovolemia/sangue , Norepinefrina/sangue , Resistência Física/fisiologia , Renina/sangue , Fatores Sexuais , Volume Sistólico/fisiologia , Síncope/sangue , Vasopressinas/sangueRESUMO
To investigate precisely the fluid shifts associated with water drinking in humans, we measured continuously blood density and plasma electrolyte concentrations using the mechanical oscillator technique and ion-selective electrodes, respectively, in healthy young volunteers before (10 min) and after (48 min) water drinking for a period of 2 min. Beat-by-beat blood pressure was also monitored throughout the experiment. Drinking 1 l tap water caused a transient increase in blood density immediately after the drinking episode (from 1051.1+/-0.5 g/l before drinking to 1051.8+/-0.5 g/l 4 min after the start of drinking, P<0.05), followed by a gradual reduction (1050.1+/-0.5 g/l at 31 min). This drinking-induced change paralleled those of haematocrit, plasma density and plasma volume. Plasma [Na+] and [Cl-] and osmolality decreased after drinking without transient increases and reached minima at about 30 min. A transient increase in mean arterial blood pressure was observed prior to the increase in blood density. These findings suggest that water drinking causes a biphasic change in plasma volume: initial haemoconcentration, probably due to sympathetic acceleration, followed by haemodilution due to the post-absorptive effect, and further suggest that the fluid shift associated with the initial haemoconcentration is isosmotic.
Assuntos
Volume Sanguíneo/fisiologia , Ingestão de Líquidos/fisiologia , Hemodiluição , Adulto , Pressão Sanguínea/fisiologia , Cloretos/sangue , Deslocamentos de Líquidos Corporais/fisiologia , Frequência Cardíaca/fisiologia , Hematócrito , Humanos , Masculino , Concentração Osmolar , Sódio/sangueAssuntos
Hepatite C/epidemiologia , Transplante de Rim/fisiologia , Complicações Pós-Operatórias/virologia , Adolescente , Adulto , Criança , Feminino , Sobrevivência de Enxerto , Hepatite C/mortalidade , Hepatite C/fisiopatologia , Humanos , Japão , Transplante de Rim/mortalidade , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Prevalência , Diálise Renal , Estudos Retrospectivos , Taxa de Sobrevida , Doadores de Tecidos , Falha de Tratamento , Resultado do TratamentoRESUMO
BACKGROUND: The present study was designed to examine whether water temperature during head-out immersion (HOI) modifies hemodilution dynamics. METHODS: We made continuous measurements of blood density (rho(b)) during HOI at 3 different water temperatures; the lower critical (32 degrees C), neutral (34.5 degrees C), and upper critical (36 degrees C) temperatures in 6 healthy male volunteers. Blood was withdrawn continuously from the antecubital vein for measurement of rho(b) during 60 min of water immersion with a 10-min control period before the immersion. The density was measured with the mechanical oscillator technique. Hematocrit (Hct), plasma density (rho(p)), and osmolality were measured at 5-min intervals. Erythrocyte density (rho(e)) was calculated from rho(b), rho(p) and Hct. Cardiac output and BP were measured to calculate total peripheral resistance. RESULTS: Hct, rho(b), and rho(p) decreased rapidly in the first 20-25 min of immersion and were maintained at a reduced level during immersion. Plasma volume calculated from rho(p) and Hct increased with the rho(b) reduction. These immersion-induced changes were independent of these water temperatures. Plasma osmolality and rho(e) remained constant throughout the experimental period in the three temperature conditions, indicating that the increase in plasma volume and hence hemodilution was induced by an isotonic fluid shift from extravascular space. The total peripheral resistance increased inversely in proportion to the water temperature during HOI. CONCLUSION: In the present condition, water temperature did not modify the net transcapillary fluid transfer during HOI in the presence of the temperature dependent increase in vascular tone.
Assuntos
Viscosidade Sanguínea/fisiologia , Índices de Eritrócitos/fisiologia , Deslocamentos de Líquidos Corporais/fisiologia , Hematócrito , Imersão/efeitos adversos , Volume Plasmático/fisiologia , Temperatura , Água , Simulação de Ausência de Peso/efeitos adversos , Adulto , Resistência Capilar/fisiologia , Hemorreologia , Humanos , Masculino , Monitorização Fisiológica/métodos , Concentração Osmolar , Fatores de TempoRESUMO
A concise synthesis of a versatile chiral C4 building block for 2-aminoalkanols, (1S)-1-[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]-2-hydroxyethylammo nium benzoate (1a), was described. 1 (1a and its enantiomer 1b) acted as four stereoisomers of optically active 2-amino-1,3,4-butanetriol. The versatility of 1 was demonstrated by its application to the practical synthesis of nelfinavir (2), a potent HIV-protease inhibitor, as well as by the stereospecific synthesis of three diastereomers of 2.
Assuntos
Amino Álcoois/química , Amino Álcoois/síntese química , Inibidores da Protease de HIV/química , Nelfinavir/química , EstereoisomerismoRESUMO
We report a case of a compound adrenal medullary tumor. A 63-year-old woman was referred to our hospital for examination of a right adrenal tumor, incidentally found by abdominal computed tomography (CT). CT and magnetic resonance imaging (MRI) revealed a round heterogeneous tumor, 5 cm in diameter, on the upper pole of the right kidney. A view of the total body scan demonstrated the uptake into the tumor after the injection of 123I-metaiodobenzyl-guanidine. Serum and urinary adrenaline levels were slightly elevated, and urinary excretion of vanillylmandelic acid was markedly elevated. Her blood pressure was normal. From these findings, the tumor was suspected to be a pheochromocytoma of the right adrenal gland and was resected reteroperitoneally. Pathological diagnosis was a compound adrenal medullary tumor, which was composed of pheochromocytoma and ganglioneuroma. This combination of the adrenal medullary tumor is extremely rare, and to date this case may be the sixth case in the Japanese medical literature.
Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Medula Suprarrenal , Ganglioneuroma/patologia , Neoplasias Primárias Múltiplas , Feocromocitoma/patologia , 3-Iodobenzilguanidina , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Feminino , Ganglioneuroma/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Feocromocitoma/diagnóstico por imagem , CintilografiaRESUMO
BACKGROUND: This study examines the relationship between the threshold for plasma vasopressin concentration [PVP] responses and diuresis (Gauer-Henry reflex), and tests the hypothesis that water intake would not influence diuresis. METHODS: Eight men (19-25 yr) underwent four treatments: euhydration in air (Eu-air), euhydration in water immersion (Eu-H2O), and with prior 3.6% hypohydration in air (Hypo-air), and hypohydration in immersion (Hypo-H2O). Ad libitum drinking was allowed during the 3-h experimental and 1-h recovery periods. RESULTS: Drinking was greatest during the first 10 min: 3.5 ml x kg(-1) with Hypo-air (450 ml x 3 h(-1)) and only 1.7 ml x kg(-1) (p < 0.05) with Hypo-H2O (235 ml x 3 h(-1)). At 1 h, concomitant [PVP] decreased from a control level of 6.6+/-1.5 to 4.0+/-1 .0 pg x ml(-1) (delta = 2.6 pg x ml(-1), p < 0.05) with Hypo-air, and from 5.9+/-0.6 to 2.3+/-0.2 pg x ml(-1) (delta = 3.6 pg x ml(-1), p < 0.05) with Hypo-H2O. Urine flow was unchanged from control level (<1.0 ml x min(-1)) with Hypo-air, Hypo-H2O, and Eu-air, but increased to 4-5 ml x min(-1) with Eu-H2O. Neither water intake volume nor urine flow was related to the magnitude of [PVP] depression. Regression of Uosm/Posm ratio on [PVP] and urine flow indicated that [PVP] above 2 pg x ml(-1) did not affect urine flow. Thus, ad libitum water intake in previously hypohydrated subjects did not affect urine flow or the decrease in [PVP]. The threshold [PVP] to initiate significant diuresis was about 2 pg x ml(-1), and significant diuresis can occur with no change in [PVP] maintained at about 1 pg x ml(-1) during immersion in euhydrated subjects. CONCLUSIONS: Thus, it appears that the Gauer-Henry reflex is not the major mechanism for immersion-induced diuresis. Clearly, other diuretic factors are also involved.
Assuntos
Desidratação/fisiopatologia , Diurese/fisiologia , Comportamento de Ingestão de Líquido/fisiologia , Imersão/fisiopatologia , Reflexo/fisiologia , Vasopressinas/sangue , Vasopressinas/fisiologia , Equilíbrio Hidroeletrolítico/fisiologia , Adulto , Ar , Homeostase/fisiologia , Humanos , Masculino , Concentração Osmolar , Análise de Regressão , Fatores de Tempo , Urodinâmica/fisiologiaRESUMO
A case of resection of metastatic multiple lung malignant pheochromocytoma is presented. Seven years before, total resection of the right adrenal gland and the right kidney was performed to remove a pheochromocytoma. During the post-surgical observation in the urology outpatient clinic, the blood noradrenalin concentration increased and multiple lung metastatic nidi were observed by chest X-ray. An excision was made to remove 3 wedge-shape metastatic nidi from both lungs. In the third year after the removal of the pulmonary metastatic nidi, a resection was again performed due to recurrence in the left retroperitoneal lymph node. Another recurrence was found in the S6 liver 1 year after the removal of the lymph node, and TAE and PEIT were conducted. When the recurrent metastatic nidi were found, the blood noradrenalin concentration was elevated, and it normalized after treatment. In this case, careful and long-term observation including monitoring the blood noradrenalin concentration in the outpatient clinic and positive surgical treatment proved effective. The patient is currently in good health without signs of recurrence 12 years after the removal of the primary adrenal nidus and 6 years after the removal of the pulmonary metastatic nidus.
Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Feocromocitoma/secundário , Feocromocitoma/cirurgia , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Renais/secundário , Neoplasias Hepáticas/secundário , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The hydrostatic pressure gradient during head-out water immersion (HOI) causes a blood shift from the legs into the thoracic cavity to stretch the receptors in the cardiac atria and results in a diuresis in hydrated subjects. The present study was conducted to examine whether the HOI-induced diuresis and related circulatory and hormonal changes were attenuated in the subjects who had no legs (legless men). METHODS: Two legless men served as the subjects. They lost both legs 15 and 17 yr ago by accidents and were otherwise healthy. Six normal males participated as controls. The experimental protocol was consisted of a 1-h control, a 3-h HOI (water temperature, 34.5 degrees C) and a 1-h recovery. RESULTS: Average urine flow (0.6 ml x min(-1)), urinary excretion of sodium (90 microeq x min(-1)), and osmolal clearance (1.4 ml x min(-1)) of the legless subjects increased in the first h of immersion to 0.7 ml x min(-1), 139 microeq x min(-1), and 1.8 ml x min(-1), respectively. These values remained elevated during HOI, however, the magnitude of the increase was smaller compared with the control subjects. Plasma arginine vasopressin was significantly (p < 0.05) decreased from 1.0+/-0.4 microU x 100 ml(-1) to 0.4+/-0.2 microU x 100 ml(-1) during HOI in the normal subjects, but was not in the legless subjects (from 0.5 at control period to 0.4 microU x 100 ml(-1) during HOI). A concurrent reduction of aldosterone and plasma renin activity was observed with an increase in atrial natriuretic peptide during HOI in both subject groups, however, the magnitude of the changes was smaller in the legless subjects compared with the control subjects. Similarly, the average increase in cardiac output during HOI in the legless subjects (by 17%) was less compared with the control subjects (by 31%). CONCLUSION: The magnitude of renal, endocrine, and cardiovascular changes in response to HOI in the legless subjects were less than in control subjects, but the responses were qualitatively similar. Accordingly, we suggest that the cephalad blood expansion during immersion is not only due to translocation of blood from the legs but also the abdominal region.
Assuntos
Amputados , Sistema Cardiovascular/fisiopatologia , Sistema Endócrino/fisiopatologia , Imersão/fisiopatologia , Rim/fisiopatologia , Perna (Membro) , Adulto , Aldosterona/sangue , Arginina Vasopressina/sangue , Fator Natriurético Atrial/sangue , Estudos de Casos e Controles , Diurese/fisiologia , Deslocamentos de Líquidos Corporais/fisiologia , Hematócrito , Hemodinâmica/fisiologia , Humanos , Imersão/efeitos adversos , Masculino , Renina/sangue , Fatores de Tempo , UrodinâmicaRESUMO
BACKGROUND: This experiment was designed to examine the involvement of the autonomic nervous system in the production of hyperbaric bradycardia. METHODS: Four male divers were exposed to a He-O2 (heliox) environment at 24 atmosphere absolute (atm abs) for 7 d. The heart rate (HR) and respiratory rate were recorded at rest in the morning (0700 h) and at night (2230 h) on 1 d during a 5-d predive control, 2 d during a 7-d saturation dive at 24 atm abs, 2 d during decompression, and on 1 d during a 4-d postdive period. Cardiac sympathetic and parasympathetic activities were estimated by using a spectral analysis of the variability of R-R intervals. RESULTS: The morning HR did not fluctuate throughout the experimental days. The night time HR decreased (p < 0.05) by 11.8% on the first day at 24 atm abs compared with that of the predive control. The bradycardia diminished gradually and returned to the predive level with continued exposure at 24 atm abs. The high-frequency power of the cardiac variability, an index of cardiac parasympathetic activity, increased (p < 0.05) only in the first night at 24 atm abs, whereas the low-frequency power and a ratio of low- to high-frequency power, an index of cardiac sympathetic activity, were unchanged. CONCLUSIONS: The present results suggest that an increased parasympathetic activity rather than a decrease in the sympathetic activity is responsible for the bradycardia on exposure to heliox dry saturation dive at 24 atm abs. The mechanism of the gradual disappearance of the bradycardia is unknown, but perhaps it may be related to the development of cardiovascular deconditioning.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Bradicardia/fisiopatologia , Mergulho , Coração/inervação , Adulto , Bradicardia/etiologia , Ritmo Circadiano , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Nervo Vago/fisiologiaRESUMO
Tacrolimus has already gained a high reputation as an induction-maintenance immunosuppressive therapy after kidney transplantation. Recently, it is being used as rescue therapy against rejection, and its effectiveness also appears to have been established to some extent. In this study, we evaluated the efficacy of Tacrolimus rescue therapy at 4 institutions in the Kinki District. The subjects were 19 patients treated with Tacrolimus against rejection observed during immunosuppressive therapy using cyclosporin. Evaluation was made by classifying the patients into 6 with acute rejection that occurred within 3 months after transplantation (AR), 4 with late onset acute rejection that developed more than 3 months after operation (LAR), and 9 patients with chronic rejection (CR). In the AR group, many patients received combination therapy at the introduction of Tacrolimus, and the long-term outcome was satisfactory. Tacrolimus was effective in 2 (50%) of the 4 patients in the LAR group. The trough levels of Tacrolimus at its introduction were 10-15 ng/ml in the AR and LAR groups. Deterioration of the transplanted kidney function was prevented in 3 (50%) out of 6 patients in the CR group observed for less than 1 year, but it deteriorated in all 3 patients observed for 1 year or longer. The trough levels of tacrolimus at its introduction were 5-10 ng/ml in many patients in the CR group. The rescue therapy using Tacrolimus was effective against acute rejection but further follow-up is considered to be needed to evaluate its efficacy against chronic rejection.
Assuntos
Rejeição de Enxerto/terapia , Imunossupressores/uso terapêutico , Transplante de Rim , Tacrolimo/uso terapêutico , Rejeição de Enxerto/prevenção & controle , Humanos , Transplante HomólogoAssuntos
Gnathostoma , Larva Migrans/parasitologia , Adulto , Animais , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
To examine the baroreflex response in humans during acute high-altitude exposure, the carotid baroreflex cardiac responsiveness was studied using a neck chamber in seven unacclimatized male subjects. Measurements were made in a high-altitude chamber on separate days at sea level and during 1-h exposure at two different altitudes of 3,800 m [partial pressure of oxygen in inspired air (PI(O2)) = 90 mmHg] and 4,300 m (PI(O2) = 82 mmHg). R-R intervals were plotted against neck chamber pressures, and the baroreceptor response was analyzed by applying a four-parameter sigmoidal logistic function. The baroreceptor response curve shifted downward in either altitude, reflecting a tachycardic response at high altitude, and the magnitude of the shift was greater at 4,300 m than at 3,800 m. There was no change in the sigmoidal parameters at 3,800 m compared with sea level except for a reduction (P < 0.05) of the minimum R-R interval. At 4,300 m the maximal R-R range, slope coefficient, minimum R-R interval, and maximal gain of the curve decreased significantly (P < 0.05) compared with sea level values, whereas the centering point of the curve remained unchanged. These results suggest that hypoxia (PI(O2) = 82 mmHg) reduces the sensitivity of carotid baroreflex cardiac response.
Assuntos
Altitude , Barorreflexo/fisiologia , Artérias Carótidas/fisiologia , Frequência Cardíaca/fisiologia , Adulto , Pressão Sanguínea/fisiologia , Humanos , Masculino , Montanhismo/fisiologia , Oxigênio/sangue , Fatores de TempoRESUMO
BACKGROUND: Recent studies have shown that 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI), a new agent for myocardial perfusion imaging, can be successfully applied to parathyroid imaging. We evaluated the efficacy of 99mTc-MIBI scintigraphy for preoperative localization of enlarged parathyroid glands in patients with hyperparathyroidism. PATIENTS AND METHODS: From June 1994 to September 1996, 24 patients with biochemical confirmation of hyperparathyroidism were studied with 99mTc-MIBI scintigraphy prior to operation. Eleven patients had primary hyperparathyroidism (PHPT) and 13 had secondary hyperparathyroidism (SHPT) associated with chronic renal failure, including one patient with recurrent disease after subtotal parathyroidectomy. A positive 99mTc-MIBI scan for an enlarged gland was defined as an area of persistent focal uptake on the delayed image acquired at 150 min after intravenous injection of 600 MBq of 99mTc-MIBI. RESULTS: Of 11 patients with PHPT, 10, were found to have solitary parathyroid adenomas at surgery and one patient had primary hyperplasia. 99mTc-MIBI scintigraphy accurately detected 9 of 10 adenomas and 2 of 3 hyperplastic glands with no false positive results. Both of the two glands that were not detected by 99mTc-MIBI weighed 200 mg. The mean weight of the 11 glands that were visualized was 1264 mg (range 300 approximately 4300 mg). The sensitivity and predictive value positive for PHPT were 84.6% and 100%, respectively. In 13 patients with SHPT, all of 49 parathyroid glands were identified during surgery, with 43 hyperplastic glands and 6 normal-size glands. Of 43 hyperplastic glands, 28 were detected by 99mTc-MIBI and there was significant difference between the mean weight of these 28 glands (999 mg, range 290 approximately 2630 mg) and that of the 15 nonimaged hyperplastic glands (283 mg, range 90 approximately 540 mg). None of the six normal glands were imaged with 99mTc-MIBI. One patient had a false positive scan caused by a thyroid nodule. The sensitivity and predictive value positive for SHPT were 65.1% and 96.6%, respectively. CONCLUSION: 99mTc-MIBI scintigraphy is an excellent imaging method for localization of enlarged parathyroid glands in patients with hyperparathyroidism, especially with PHPT. However, it has the difficulty to demonstrate enlarged glands smaller than 300 mg in weight.
Assuntos
Hiperparatireoidismo/diagnóstico por imagem , Glândulas Paratireoides/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Adulto , Feminino , Humanos , Hiperparatireoidismo Secundário/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , CintilografiaRESUMO
Plasma arginine vasopressin (AVP) concentration is reduced in human subjects during prolonged saturation dive exposures of 4 atmospheres absolute (atm abs) and greater. The objectives of the present study were to determine if AVP would be reduced in eight male subjects during a 1-h exposure of 3 atm abs air and, if so, to determine the mechanisms responsible for the AVP response. Assessments of transmural central venous pressure (central venous pressure-esophageal pressure) and cardiac volume measurements were made to evaluate the possible role of cardiopulmonary receptors on the AVP response. Also, plasma osmolality (P(osmol)), venous blood gases, and mean corpuscular volume (MCV) were determined to evaluate potential effects of osmoreceptor and other fluid shifts on AVP release. AVP decreased (P < 0.05) by 0.5 microU/ml at 3 atm abs, whereas the transmural central venous pressure and cardiac volume remained unchanged throughout the experimental periods. A significant reduction (P < 0.05) in P(osmol) (by approximately 3 mosmol/kgH2O) was detected at 3 atm abs. Therefore, we conclude that the reduction in P(osmol) may cause the reduction in AVP during exposure to 3 atm abs pressure. The reduction in P(osmol) without water intake requires the postulation of an internal source of water. We propose that the threefold increase (P < 0.01) in venous PO2 and concomitant decrease (P < 0.05) in venous MCV suggest that the red blood cell may contribute to hypotonicity at 3 atm abs.
Assuntos
Equilíbrio Ácido-Base , Pressão do Ar , Arginina Vasopressina/metabolismo , Hemodinâmica , Adulto , Arginina Vasopressina/sangue , Bicarbonatos/sangue , Pressão Sanguínea , Dióxido de Carbono/sangue , Pressão Venosa Central , Mergulho , Volume de Eritrócitos , Esôfago/fisiologia , Átrios do Coração , Frequência Cardíaca , Hematócrito , Hemoglobinas/análise , Humanos , Concentração de Íons de Hidrogênio , Masculino , Oxigênio/sangue , Volume Plasmático , Pressorreceptores/fisiologia , Pressão , Respiração , Volume SistólicoRESUMO
The purpose of this study was to examine the effect of hyperthermia on the carotid baroreceptor-cardiac reflexes in humans. Nine healthy males underwent acute hyperthermia (esophageal temperature -38.0 degrees C) produced by hot water-perfused suits. Beat-to-beat heart rate (HR) responses were determined during positive and negative R-were-triggered neck pressure steps from +40 to -65 mm Hg during normothermia and hyperthermia. The carotid baroreceptor-cardiac reflex sensitivity was evaluated from the maximum slope of the HR response to changes in carotid distending pressure. Buffering capacity of the HR response to carotid distending pressure was evaluated in % from a reference point calculated as (HR at 0 mm Hg neck pressure-minimum HR)/HR range x 100. An upward shift of the curve was evident in hyperthermia because HR increased from 57.7 +/- 2.4 beats/min in normothermia to 88.7 +/- 4.1 beats/min in hyperthermia (P < 0.05) without changes in mean arterial pressure. The maximum slope of the curve in hyperthermia was similar to that in normothermia. The reference point was increased (P < 0.05) during hyperthermia. These results suggest that the sensitivity of the carotid baroreflex of HR remains unchanged in hyperthermia. However, the capacity for tachycardia response to rapid onset of hypotension is reduced and the capacity for bradycardia response to sudden hypertension is increased during acute hyperthermia.
Assuntos
Barorreflexo/fisiologia , Febre/fisiopatologia , Frequência Cardíaca/fisiologia , Doença Aguda , Adulto , Pressão Sanguínea/fisiologia , Bradicardia/complicações , Bradicardia/fisiopatologia , Seio Carotídeo/fisiologia , Febre/complicações , Humanos , Hipotensão/complicações , Hipotensão/fisiopatologia , Masculino , Taquicardia/complicações , Taquicardia/fisiopatologiaRESUMO
To study the reliability of formulas for calculating mean skin temperature (Tsk), values were computed by 18 different techniques and were compared with the mean of 10,841 skin temperatures measured by infrared thermography. One hundred whole-body infrared thermograms were scanned in ten resting males while changing the air temperature from 40 degrees C to 4 degrees C. Local, regional average and mean skin temperatures were obtained using an image processing system. The agreement frequency, defined as the percentage of the calculated Tsk values which agreed with the corresponding infrared thermographic Tsk within +/- 0.2 degree C, ranged for with the various formulas from 7% to 80%. In many sites, the local skin temperature did not coincide with the regional average skin temperature. When the local skin temperatures which showed the highest percentage similarity to the regional average skin temperature within +/- 0.4 degree C were applied to the formula, the agreement frequency was markedly improved for all formulas. However, the agreement frequency was not affected by changing the weighting factors from specific constants to individually measured values of regional surface area. By applying the physiologically reliable accuracy range of +/- 0.2 degree C in the moderate and +/- 0.4 degree C in the cool condition, agreement frequencies of at least 95% were observed in formulas involving seven or more skin temperature measurement sites, including the hand and foot. We conclude that calculation of a reliable mean skin temperature must involve more than seven skin temperature measurement sites regardless of ambient temperature. Optimal sites for skin temperature measurement are proposed for various formulas.
Assuntos
Temperatura Cutânea , Termografia/métodos , Adulto , Humanos , Masculino , Computação Matemática , Termografia/estatística & dados numéricosRESUMO
The patient was a 70-year-old male with familial amyloidosis of Finnish type who complained of heat intolerance due to anhidrosis during outdoor activities in summer. A water-cooled TM-2 vest was tried for this patient to reduce his body heat during exercises. Following the morning activities including jogging in August his body temperature rose up to 38.0 degrees C without wearing the partly frozen vest. However, when he wore it, his temperature rose up to only 37.2 degrees C after the exercises, which was 0.8 degree C lower than when he did not wear the vest. Headache and tachycardia during and following the morning activities did not appear by wearing the vest. In the heat loading test, in which the room temperature was raised from 28.0 degrees C to 38.0 degrees C for 15 minutes and kept at 38.0 degrees C for 60 minutes with 60% humidity, the rises of his skin and esophageal temperatures with wearing the partly frozen vest for the last 60 minutes were 1.2 degrees C and 0.4 degree C lower, respectively, than his skin and esophageal temperatures without wearing it. Concomitantly, the increase of heart rate was suppressed in the same test condition. Wet vest in running water showed the similar effects. Therefore, we concluded that the use of water-cooled TM-2 vest was effective in alleviating the symptoms and signs of his heat intolerance.
Assuntos
Amiloidose/complicações , Amiloidose/genética , Crioterapia , Transtornos de Estresse por Calor/terapia , Hipo-Hidrose/etiologia , Idoso , Vestuário , Humanos , MasculinoRESUMO
A 65-year-old man and a 35-year-old woman were diagnosed with intrapelvic tumors originating from the sacral nerves by computed tomographic (CT) scan, magnetic resonance imaging (MRI) and angiography. These tumors were tightly adhered to the iliac arteries and veins and could not be resected completely. Since the cryostat sections revealed benign schwannomas histopathologically, we enucleated the tumors without the pseudocapsules. All of the 57 intrapelvic schwannomas previously reported in Japan were resected with pseudocapsules. Both of our patients showed improvement of subjective symptoms, but should be followed up and examined for the presence of regrowth of tumors.