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1.
Diagnostics (Basel) ; 13(21)2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37958266

RESUMO

OBJECTIVES: To assess the effect of oxygen-ozone therapy guided by percutaneous Computed Tomography (CT) compared to corticosteroids in individuals experiencing lower back pain (LBP) not attributed to underlying bone-related issues. METHODS: A total of 321 patients (192 males and 129 females, mean age: 51.5 ± 15.1 years) with LBP were assigned to three treatment groups: group A) oxygen-ozone only, group B) corticosteroids only, group C) oxygen-ozone and corticosteroids. Treatment was administered via CT-guided injections to the intervertebral disc (i.e., intradiscal location). Clinical improvement of pain and functionality was assessed via self-reported pain scales and magnetic resonance (MR) and CT imaging. RESULTS: At all follow-up times, the mean score of the numeric rating scale and the total global pain scale (GPS) of study groups receiving oxygen-ozone (groups A and C) were statistically significantly lower than the study group receiving corticosteroids only (group B), with p < 0.001. There was a statistically significant difference between groups A and C at 30 days for the numeric rating scale. CONCLUSIONS: The percutaneous application of oxygen-ozone in patients with LBP due to degeneration of the lumbosacral spine showed long-lasting significant pain reduction of up to two years post-treatment when compared to corticosteroids alone. Combination therapy of oxygen-ozone and corticosteroids can be useful as corticosteroids showed statistically significant improvement in LBP earlier than the oxygen-ozone-only treatment.

2.
Molecules ; 28(4)2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36838741

RESUMO

Developing highly efficient semiconductor metal oxide (SMOX) sensors capable of accurate and fast responses to environmental humidity is still a challenging task. In addition to a not so pronounced sensitivity to relative humidity change, most of the SMOXs cannot meet the criteria of real-time humidity sensing due to their long response/recovery time. The way to tackle this problem is to control adsorption/desorption processes, i.e., water-vapor molecular dynamics, over the sensor's active layer through the powder and pore morphology design. With this in mind, a KIT-5-mediated synthesis was used to achieve mesoporous tin (IV) oxide replica (SnO2-R) with controlled pore size and ordering through template inversion and compared with a sol-gel synthesized powder (SnO2-SG). Unlike SnO2-SG, SnO2-R possessed a high specific surface area and quite an open pore structure, similar to the KIT-5, as observed by TEM, BET and SWAXS analyses. According to TEM, SnO2-R consisted of fine-grained globular particles and some percent of exaggerated, grown twinned crystals. The distinctive morphology of the SnO2-R-based sensor, with its specific pore structure and an increased number of oxygen-related defects associated with the powder preparation process and detected at the sensor surface by XPS analysis, contributed to excellent humidity sensing performances at room temperature, comprised of a low hysteresis error (3.7%), sensitivity of 406.8 kΩ/RH% and swift response/recovery speed (4 s/6 s).


Assuntos
Óxidos , Umidade , Pós , Óxidos/química
3.
Materials (Basel) ; 15(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35806590

RESUMO

Polycrystalline samples of NaCo2-xCuxO4 (x = 0, 0.01, 0.03, 0.05) were obtained from powder precursors synthesized by a mechanochemically assisted solid-state reaction method (MASSR) and a citric acid complex method (CAC). Ceramic samples were prepared by pressing into disc-shaped pellets and subsequently sintering at 880 °C in an argon atmosphere. Effects of low concentrations of Cu doping and the above-mentioned synthesis procedures on the thermoelectric and mechanical properties were observed. The electrical resistivity (ρ), the thermal conductivity (κ) and the Seebeck coefficient (S) were measured simultaneously in the temperature gradient (ΔT) between the hot and cold side of the sample, and the figure of merit (ZT) was subsequently calculated. The ZT of the CAC samples was higher compared with the MASSR samples. The highest ZT value of 0.061 at ΔT = 473 K was obtained for the sample with 5 mol% of Cu prepared by the CAC method. The CAC samples showed better mechanical properties compared to the MASSR samples due to the higher hardness of the CAC samples which is a consequence of homogeneous microstructure and higher density obtained during sintering of these samples. The results confirmed that, besides the concentration of Cu, the synthesis procedure considerably affected the thermoelectric and mechanical properties of NaCo2O4 (NCO) ceramics.

4.
Microsc Res Tech ; 85(4): 1557-1567, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34888993

RESUMO

In the present work, a biomaterial (SBA-16/HA) based on the growth of hydroxyapatite (HA) particles within an organized silica structure SBA-16 (Santa Barbara Amorphous-16) was developed to evaluate its application to act as a porous microenvironment promoting attachment and viability of human dental pulp stem cells of healthy deciduous teeth (SHED). First, SHED were isolated and their phenotypes were evaluated by flow cytometry. The samples of SBA-16/HA were characterized by X-ray diffraction (XRD), small and wide angle X-ray scattering (SWAXS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) equipped with energy dispersive spectra detector (EDS). Afterward, cells were cultured in the eluates of the above-mentioned biomaterial aged for 24 hr, 7. and 14 days. Bio-Oss® and dentin particles are involved for comparison and cells are cultured in the eluates of these two materials also. Thiazolyl Blue Tetrazolium bromide assay-MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay) was used for the determination of cell viability. The results obtained by all aforementioned characterization methods of SBA-16/HA, revealed a uniform spherical mesoporous structure, an intrinsic characteristic of this material. This material displayed excellent biocompatibility on SHEDs, and even proliferative potential, indicating that SBA-16/HA could potentially serve as a suitable substrate for bone regeneration. Contrary to SBA-16/HA, dentin particles showed low cytotoxicity at all time points, compared to control and Bio-Oss®groups. Our results substantiate the idea that SBA-16/HA has a beneficial effect on SHEDs, thus paving the way toward developing new material for bone replacement.


Assuntos
Durapatita , Nanocompostos , Idoso , Polpa Dentária , Dentina/química , Durapatita/química , Humanos , Dióxido de Silício/análise , Dióxido de Silício/química , Dióxido de Silício/farmacologia , Células-Tronco , Difração de Raios X
5.
Int J Clin Pract ; 74(11): e13608, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32649036

RESUMO

BACKGROUND/AIMS: The most effective and safe treatment protocol for Graves' orbitopathy (GO) needs to be further assessed. The aim of the present study was to evaluate the efficacy, safety and outcome of parenteral versus parenteral and oral glucocorticoid (GC) protocols in euthyroid patients with untreated and active moderate to severe GO. METHODS: This was a retrospective observational study in 140 patients comparing intravenous GC pulses only (IVGC group, 74 patients, 51 ± 11 years) with historical controls of combined oral and intravenous GC therapy (CombGC group, 66 patients, 49 ± 10 years, P = ns). IVGC therapy included infusions of 500 mg of methylprednisolone weekly for the first six weeks, followed by infusions of 250 mg weekly for the remaining six weeks (cumulative dose 4.5 g). CombGC therapy included 500 mg of methylprednisolone in 500 mL of saline solution for two alternative days, followed by oral prednisone tapering dose repeated each month for the next 5 months (cumulative dose 10.2 g). RESULTS: The overall success of the treatment was 43/66 (65%) in the CombGC group and 37/73 (51%, P = .071) in the IVGC group. Deterioration of GO developed in four (6%) patients during CombGC therapy and in nine (12%, P = .214) patients during IVGC therapy. After 6 months, relapse of GO was observed in 10/37 (26%) in the IVGC group, whereas none of the patients in CombGC had a relapse (P < .001). There were significantly more side effects in the CombGC versus IVGC group (49/66, 74% vs 28/74, 38%, P < .001). CONCLUSIONS: Our data suggest that CombGC therapy was more efficient with significantly less relapse rate, but with more side effects in comparison to IVGC therapy.


Assuntos
Oftalmopatia de Graves , Administração Intravenosa , Glucocorticoides/efeitos adversos , Oftalmopatia de Graves/tratamento farmacológico , Humanos , Metilprednisolona/uso terapêutico , Estudos Retrospectivos
6.
Sensors (Basel) ; 17(8)2017 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-28800063

RESUMO

This paper describes the fabrication and the characterization of an original example of a miniaturized resistive-type humidity sensor, printed on flexible substrate in a large-scale manner. The fabrication process involves laser ablation for the design of interdigitated electrodes on PET (Poly-Ethylene Terephthalate) substrate and a screen-printing process for the deposition of the sensitive material, which is based on TiO2 nanoparticles. The laser ablation process was carefully optimized to obtain micro-scale and well-resolved electrodes on PET substrate. A functional paste based on cellulose was prepared in order to allow the precise screen-printing of the TiO2 nanoparticles as sensing material on the top of the electrodes. The current against voltage (I-V) characteristic of the sensor showed good linearity and potential for low-power operation. The results of a humidity-sensing investigation and mechanical testing showed that the fabricated miniaturized sensors have excellent mechanical stability, sensing characteristics, good repeatability, and relatively fast response/recovery times operating at room temperature.

7.
Scand J Clin Lab Invest ; 77(4): 295-297, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28362116

RESUMO

Assessment of insulin sensitivity based on a single measurement of insulin and glucose, is both easy to understand and simple to perform. The tests most often used are HOMA and QUICKI. The aim of this study was to assess the biological variability of estimates of insulin sensitivity using HOMA and QUICKI indices. After a 12-h fast, blood was sampled for insulin and glucose determination. Sampling lasted for 90 min with an intersample interval of 2 min. A total of 56 subjects were included in the study, and in nine subjects sampling was done before and after weight reduction, so total number of analyzed series was 65. To compute the reference value of the insulin sensitivity index, averages of all 46 insulin and glucose samples were used. We also computed point estimates (single value estimates) of the insulin sensitivity index based on the different number of insulin/glucose samples (1-45 consecutive samples). To compute the variability of point estimates a bootstrapping procedure was used using 1000 resamples for each series and for each number of samples used to average insulin and glucose. Using a single insulin/glucose sample HOMA variability was 26.18 ± 4.31%, and QUICKI variability was 3.30 ± 0.54%. For 10 samples variability was 11.99 ± 2.22% and 1.62 ± 0.31% respectively. Biological variability of insulin sensitivity indices is significant, and it can be reduced by increasing the number of samples. Oscillations of insulin concentration in plasma are the major cause of variability of insulin sensitivity indices.


Assuntos
Resistência à Insulina , Adulto , Glicemia/análise , Feminino , Humanos , Insulina/sangue , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Adulto Jovem
8.
Srp Arh Celok Lek ; 144(3-4): 200-3, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27483566

RESUMO

INTRODUCTION: In interpreting thyroid hormones results it is preferable to think of interference and changes in concentration of their carrier proteins. OUTLINE OF CASES: We present two patients with discrepancy between the results of thyroid function tests and clinical status. The first case presents a 62-year-old patient with a nodular goiter and Hashimoto thyroiditis. Thyroid function test showed low thyroid-stimulating hormone (TSH) and normal to low fT4. By determining thyroid status (TSH, T4, fT4,T3, fT3) in two laboratories, basal and after dilution, as well as thyroxine-binding globulin (TBG), it was concluded that the thyroid hormone levels were normal. The results were influenced by heterophile antibodies leading to a false lower TSH level and suspected secondary hypothyroidism.The second case, a 40-year-old patient, was examined and followed because of the variable size thyroid nodule and initially borderline elevated TSH, after which thyroid status showed low level of total thyroid hormones and normal TSH. Based on additional analysis it was concluded that low T4 and T3 were a result of low TBG. It is a hereditary genetic disorder with no clinical significance. CONCLUSION: Erroneous diagnosis of thyroid disorders and potentially harmful treatment could be avoided by proving the interference or TBG deficiency whenever there is a discrepancy between the thyroid function results and the clinical picture.


Assuntos
Anticorpos Heterófilos/sangue , Doenças Genéticas Ligadas ao Cromossomo X/sangue , Bócio Nodular/sangue , Doença de Hashimoto/sangue , Testes de Função Tireóidea/métodos , Hormônios Tireóideos/sangue , Tireotropina/sangue , Globulina de Ligação a Tiroxina/deficiência , Globulina de Ligação a Tiroxina/metabolismo , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tiroxina/sangue , Tri-Iodotironina/sangue
9.
Hormones (Athens) ; 13(2): 222-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24776622

RESUMO

OBJECTIVE: Glucocorticoids (GC) are the treatment of choice for moderate-to-severe and active Graves' orbitopathy (GO), but optimal treatment is still . The aim of the present study was to analyze the efficacy and tolerability of combined parenteral GC pulse therapy followed by oral GC in the interpulse period. DESIGN: The study included 50 patients (48 ± 10 years; 37 female) with untreated, active and moderate-to-severe GO. Patients received 500 mg of methylprednisolone in 500 ml of physiologic saline. Infusion was repeated after 48 h and then followed by tapering doses of oral prednisone and the cycle repeated each month for the next 5 months. The cumulative dose was 10.2g.Ophthalmic assessment was performed before and 6 months after start of treatment. Side effects of GC therapy were evaluated and recorded each month. RESULTS: GC showed the greatest effectiveness on soft tissue changes (incorporated in the CAS). Median CAS values decreased from 4.5 to 2 (p>0.001). Improvement was demonstrated in 37 patients (74%), there was no change in 13 patients (26%) and none of the patients presented with deterioration of inflammatory status. Diplopia improved in 21 patients (42%), was unchanged in 28 patients (56%) and deteriorated in 1 patient (2%). Improvement in visual acuity occurred in 36% of patients. At 6 months, 33/50 patients (66%) demonstrated overall treatment response. Response to GC therapy was influenced by CAS, TSHRAb and smoking behavior. The only independent parameter associated with positive treatment response was CAS ≥ 4 (p<0.001). Side effects occurred in 35/50 patients (70%) and the vast majority of them were mild to moderate. During the 6-months follow-up period, 2/33 patients (6%) had relapsing GO. CONCLUSION: With appropriate selection of patients and careful monitoring during and after treatment, combined parenteral and oral GC therapy is effective and safe.


Assuntos
Glucocorticoides/administração & dosagem , Oftalmopatia de Graves/tratamento farmacológico , Metilprednisolona/administração & dosagem , Administração Oral , Adulto , Técnicas de Diagnóstico Oftalmológico , Monitoramento de Medicamentos , Feminino , Glucocorticoides/efeitos adversos , Oftalmopatia de Graves/diagnóstico , Oftalmopatia de Graves/fisiopatologia , Humanos , Infusões Intravenosas , Masculino , Metilprednisolona/efeitos adversos , Pessoa de Meia-Idade , Seleção de Pacientes , Valor Preditivo dos Testes , Pulsoterapia , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
10.
Eur J Endocrinol ; 159(5): 649-52, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18753312

RESUMO

OBJECTIVE: Interleukin 6 (IL6) has the ability to influence each level of the hypothalamo-pituitary-adrenocortical (HPA) axis. The aim of the study was to test whether IL6 concentration correlates with the adrenal cortex response to ACTH in healthy humans. We postulated that higher basal IL6 concentration would be associated with the higher cortisol response to the stimulation. DESIGN AND METHODS: Basal IL6 concentration was measured and a low dose (1 microg) ACTH test was performed to assess cortisol response. Twenty-seven apparently healthy subjects (11 male, 16 female, mean age 31.1 years, age range 22-47 years) were included in the study. RESULTS: Data are presented as mean+/-S.E.M. Basal IL6 level was 0.84+/-0.10 pg/ml. Basal cortisol was 351.9+/-18.3 nmol/l. Maximal cortisol during synacthen test was 653.0+/-20.6 nmol/l. Maximal cortisol increment was 301.1+/-20.0 nmol/l. IL6 concentration was not correlated with basal or maximal cortisol concentration, but correlated significantly with cortisol increment (r=0.63, 95% confidence interval) 0.42-0.83). CONCLUSIONS: In our study, we found that higher basal IL6 concentration is associated with the higher cortisol response to ACTH stimulation. Based on previous research and our data, IL6, even in low concentrations and under physiologic conditions, modulates adrenal cortex responsivity to ACTH. Therefore, it seems that immune modulation of HPA axis is also present under physiologic and not only pathologic conditions.


Assuntos
Cosintropina/administração & dosagem , Hormônios/administração & dosagem , Hidrocortisona/sangue , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Interleucina-6/sangue , Córtex Suprarrenal/metabolismo , Adulto , Cosintropina/sangue , Feminino , Hormônios/sangue , Humanos , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Pessoa de Meia-Idade , Estimulação Química
12.
Srp Arh Celok Lek ; 132(1-2): 28-32, 2004.
Artigo em Sérvio | MEDLINE | ID: mdl-15227962

RESUMO

INTRODUCTION: Endogenous Cushing's syndrome is a clinical state resulting from prolonged, inappropriate exposure to excessive endogenous secretion of cortisol and hence excess circulating free cortisol, characterized by loss of the normal feedback mechanisms of the hypothalamo-pituitary-adrenal axis and the normal circadian rhythm of cortisol secretion [2]. The etiology of Cushing's syndrome may be excessive ACTH secretion from the pituitary gland, ectopic ACTH secretion by nonpituitary tumor, or excessive autonomous secretion of cortisol from a hyperfunctioning adrenal adenoma or carcinoma. Other than this broad ACTH-dependent and ACTH-independent categories, the syndrome may be caused by ectopic CRH secretion, PPNAD, MAH, ectopic action of GIP or catecholamines, and other adrenel-dependent processes associated with adrenocortical hyperfunction. CASE REPORT: A 31 year-old men with 6-month history of hyperpigmentation, weight gain and proximal myopathy was refereed to Institute of Endocrinology for evaluation of hypercortisolism. At admission, patient had classic cushingold habit with plethoric face, dermal and muscle atrophy, abdominal strie rubrae and centripetal obesity. The standard laboratory data showed hyperglycaemia and hypokaliemia with high potassium excretion level. The circadian rhythm of cortisol secretion was blunted, with moderately elevated ACTH level, and without cortisol suppression after low-dose and high-dose dexamethason suppression test. Urinary SHIAA was elevated. Abdominal and sellar region magnetic resonance imaging was negative. CRH stimulation resulted in ACTH increase of 87% of basal, but without significant increase of cortisol level, only 7%. Thoracal CT scan revealed 14 mm mass in right apical pulmonary segment. A wedge resection of anterior segment of right upper lobe was performed. Microscopic evaluation showed tumor tissue consisting of solid areas of uniform, oval cells with eosinophilic cytoplasm and centrally located nuclei. Stromal tissue was scanty, and mitotic figures were infrequent. Tumor cells were immunoreactive for synaptophysin, neuron-specific enolase, and ACTH. The postoperative course was uneventful and the patient was discharged on glucocorticoid supplementation. Signs of Cushing's syndrome were in regression, and patient remained normotensive and normoglycaemic without therapy. DISCUSSION: A multitude of normal nonpituitary cells from different organs and tissues have been shown to express the POMC gene from which ACTH is derived. The tumors most commonly associated the ectopic ACTH syndrome arise from neuroendocrine tissues, APUD cells. POMC gene expression in non-pituitary cells differs from that in pituitary cells both qualitatively and quantitatively [8]. Aggressive tumors, like small cell cancer of the lung (SCCL) preferentially release intact POMC, whereas carcinoids rather overprocess the precursor, releasing ACTH and smaller peptides like CLIP. Some tumors associated with ectopic ACTH syndrome express other markers of neuroendocrine differentiation like two specific prohormone convertases (PCs). Assessment of vasopressin (V3) receptor gene expression in ACTH-producing nonpitultary tumors revealed bronchial carcinoid as a particular subset of tumors where both V3 receptor and POMC gene may be expressed in pattern indistinguishable from that in corticotroph adenoma [9]. In most, but not all, patients with ectopic ACTH syndrome, cortisol is unresponsive to high-dose dexamethason suppression test, what is used as diagnostic tool. It is not clear if the primary resistance resulted from structural abnormality of the native glucocorticoid receptor (GR), a low level of expression, or some intrinsic property of the cell line [9]. It appears that ectopic ACTH syndrome is made of two different entities. When it is because of highly differentiated tumors, with highest level of pituitary-like POMC mRNA, expressing PCs, high level of V3 receptors and GR, like bronchial carcinoids, it might be called ectopic corticotroph syndrome. In contrast, when it is caused by aggressive, poorly differentiated tumors, with much lower expression of V3 receptor, like SCCL, it might be called aberrant ACTH secretion syndrome. Carcinoid tumors have been reported in a wide range of organs but most commonly involve the lungs, bronchi, and gastrointestinal tract. They arise from neuroendocrine cells and are characterized by positive reactions to markers of neuroendocrine tissue, including neuron specific enolase, synaptophysin, and chromogranina [11]. Carcinoid tumors are typically found to contain numerous membrane-bound neurosecretory granules composed of variety of hormones and biogenic amines. One of the best characterized is serotonin, subsequently metabolized to 5-hydrohy-indolacetic acid (5-HIAA), which is excreted in the urine. In addition to serotonin, carcinoid tumors have been found to secrete ACTH, histamine, dopamine, substance P, neurotensin, prostaglandins and kallikrein. The release of serotonin and other vasoactive substances is thought to cause carcinoid syndrome, which manifestations are episodic flushing, weezing, diarrhea, and eventual right-sided valvular heart disease. These tumors have been classified as either well-differentiated or poorly differentiated neuroendocrine carcinomas. The term "pulmonary tumorlets" describes multiple microscopic nests of neuroendocrine cells in the lungs [12]. Pulmonary carcinoids make up approximately 2 percents of primary lung tumors. The majority of these tumors are perihilar in location, and patients often presents with recurrent pneumonia, cough, hemoptisis, or chest pain. The carcinoid syndrome occurs in less than 5 percent of cases. Ectopic secretion of ACTH from pulmonary carcinoid accounts for 1 percent of all cases of Cushing's syndrome. They are distinct clinical and pathologic entity, generally peripheral in location. Although they are usually typical by standard histologic criteria, they have mush greater metastatic potential than hormonally quiescent typical carcinoids [13]. Surgical treatment therefore should be one proposed for more aggressive malignant tumors. In all cases of ACTH-dependent Cushing's syndrome with regular pituitary MRI and bilateral inferior petrosal sinus sampling, thin-section and spiral CT scanning of the chest should be routine diagnostic procedure [14]. We present thirty-one year old patient with typical pulmonary carcinod with ACTH ectopic secretion consequently confirmed by histology.


Assuntos
Síndrome de ACTH Ectópico/diagnóstico , Tumor Carcinoide/metabolismo , Neoplasias Pulmonares/metabolismo , Adulto , Tumor Carcinoide/diagnóstico , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino
13.
Srp Arh Celok Lek ; 131(9-10): 370-4, 2003.
Artigo em Sérvio | MEDLINE | ID: mdl-15058215

RESUMO

Chronic fatigue syndrome (CFS) is defined as constellation of the prolonged fatigue and several somatic symptoms, in the absence of organic or severe psychiatric disease. However, this is an operational definition and conclusive biomedical explanation remains elusive. Similarities between the signs and symptoms of CFS and adrenal insufficiency prompted the research of the hypothalamo-pituitary-adrenal axis (HPA) derangement in the pathogenesis of the CFS. Early studies showed mild glucocorticoid deficiency, probably of central origin that was compensated by enhanced adrenal sensitivity to ACTH. Further studies showed reduced ACTH response to vasopressin infusion. The response to CRH was either blunted or unchanged. Cortisol response to insulin induced hypoglycaemia was same as in the control subjects while ACTH response was reported to be same or enhanced. However, results of direct stimulation of the adrenal cortex using ACTH were conflicting. Cortisol and DHEA responses were found to be the same or reduced compared to control subjects. Scott et al found that maximal cortisol increment from baseline is significantly lower in CFS subjects. The same group also found small adrenal glands in some CFS subjects. These varied and inconsistent results could be explained by the heterogeneous study population due to multifactorial causes of the disease and by methodological differences. The aim of our study was to assess cortisol response to low dose (1 microgram) ACTH using previously validated methodology. We compared cortisol response in the CFS subjects with the response in control and in subjects with suppressed HPA axis due to prolonged corticosteroid use. Cortisol responses were analysed in three subject groups: control (C), secondary adrenal insufficiency (AI), and in CFS. The C group consisted of 39 subjects, AI group of 22, and CFS group of nine subjects. Subject data are presented in table 1. Low dose ACTH test was started at 0800 h with the i.v. injection of 1 microgram ACTH (Galenika, Belgrade, Serbia). Blood samples for cortisol determination were taken from the i.v. cannula at 0, 15, 30, and 60 min. Data are presented as mean +/- standard error (SE). Statistical analysis was done using ANOVA with the Games-Howell post-hoc test to determine group differences. ACTH dose per kg or per square meter of body surface was not different between the groups. Baseline cortisol was not different between the groups. However, cortisol concentrations after 15 and 30 minutes were significantly higher in the C group than in the AI group. Cortisol concentration in the CFS group was not significantly different from any other group (Graph 1). Cortisol increment at 15 and 30 minutes from basal value was significantly higher in C group than in other two groups. However, there was no significant difference in cortisol increment between the AI and CFS groups at any time of the test. On the contrary, maximal cortisol increment was not different between CFS and other two groups, although it was significantly higher in C group than in the AI group. Maximal cortisol response to the ACTH stimulation and area under the cortisol response curve was significantly larger in C group compared to AI group, but there was no difference between CFS and other two groups. Several previous studies assessed cortisol response to ACTH stimulation. Hudson and Cleare analysed cortisol response to 1 microgram ACTH in CFS and control subjects. They compared maximum cortisol attained during the test, maximum cortisol increment, and area under the cortisol response curve. There was no difference between the groups in any of the analysed parameters. However, authors commented that responses were generally low. On the contrary Scott et al found that cortisol increment at 30 min is significantly lower in the CFS than in the control group. Taking into account our data it seems that the differences found in previous studies papers are caused by the methodological differences. We have shown that cortisol increment at 15 and 30 min is significantly lower in CFS group than in C group. Nevertheless, maximum cortisol attained during the test, maximum cortisol increment, and area under the cortisol response curve were not different between the C and CFS groups. This is in agreement with our previous findings that cortisol increment at 15 minutes has the best diagnostic value of all parameters obtained during of low dose ACTH test. However, there was no difference between CFS and AI group in any of the parameters, although AI group had significantly lower cortisol concentrations at 15 and 30 minutes, maximal cortisol response, area under the cortisol curve, maximal cortisol increment, and maximal cortisol change velocity than C group. Consequently, reduced adrenal responsiveness to ACTH exists in CFS. In conclusion, we find that regarding the adrenal response to ACTH stimulation CFS subjects present heterogeneous group. In some subjects cortisol response is preserved, while in the others it is similar to one found in secondary adrenal insufficiency.


Assuntos
Córtex Suprarrenal/fisiopatologia , Síndrome de Fadiga Crônica/fisiopatologia , Testes de Função do Córtex Suprarrenal , Hormônio Adrenocorticotrópico , Adulto , Humanos , Hidrocortisona/sangue
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