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1.
Scand J Med Sci Sports ; 33(9): 1841-1849, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37204065

RESUMO

PURPOSE: Exercise-associated hyponatremia (EAH) is common in ultra-endurance events and severe cases are more common in females. The purpose of this paper is to compare the clinical presentation of EAH between male and female triathletes in ultra-endurance competitions. METHODS: Medical records with sodium concentrations (n = 3138) from the IRONMAN® World Championships over the timeframe of 1989-2019 were reviewed for both male (n = 2253) and female (n = 885) competitors. Logistic regression was used to explore the relationships between sex, sodium concentration, and various clinical presentations. RESULTS: When comparing male and female triathletes, clinical variables found to have a different relationship with sodium concentration include altered mental status (inversely related in males and not related in females), abdominal pain, muscle cramps, hypotension, and tachycardia (directly related in males and not related in females), and vomiting and hypokalemia (not related in males and inversely related in females). Overall, males lost significantly more weight than females, and notably, approximately half of all athletes were dehydrated and lost weight. CONCLUSIONS: Altered mental status, vomiting, abdominal pain, muscle cramps, hypotension, tachycardia, and hyperkalemia appear to present differently between sexes when comparing hyponatremic to eunatremic athletes. Although overhydration is the most common etiology of hypervolemic hyponatremia, hypovolemic hyponatremia comprises a significant amount of hyponatremic triathletes. Further understanding of how EAH presents helps athletes and medical professionals identify it early and prevent life-threatening complications.


Assuntos
Hiponatremia , Humanos , Masculino , Feminino , Hiponatremia/etiologia , Cãibra Muscular/etiologia , Resistência Física/fisiologia , Exercício Físico/fisiologia , Sódio
2.
Pathologe ; 42(3): 328-332, 2021 May.
Artigo em Alemão | MEDLINE | ID: mdl-33355706

RESUMO

We report on a 72-year-old male patient suffering from weight loss, diarrhea, and epigastric pain. By means of endosonographic ultrasound, a well-circumscribed tumor mass was found in the gastric wall, suggesting a gastrointestinal stromal tumor (GIST). Biopsies were taken and processed for standard histopathological analysis. The microscopy revealed uniform, small, round cells with central nuclei and prominent cell borders embedded in vascularized stroma. Immunohistochemistry demonstrated the expression of actin, but showed negativity for cytokeratin, CD34, CD117, DOG­1, desmin, and CD45. The tumor was diagnosed as a gastral glomus tumor. The diagnosis was confirmed in the wedge resection specimen. Gastral glomus tumors are rare intramural tumors of the stomach. GIST and neuroendocrine tumor (NET) present the main differential diagnoses. Especially with regard to the epithelioid variant of GIST, clear separation can be difficult. Besides standard histological examination, immunohistochemistry and molecular analysis can be helpful since gastral glomus tumors do not obtain c­Kit- or PDGFRα mutations. Based on the fact that this tumor most commonly shows a benign biological behavior, the prognosis of gastral glomus tumors is favorable.


Assuntos
Tumores do Estroma Gastrointestinal , Tumor Glômico , Neoplasias Gástricas , Biomarcadores Tumorais , Humanos , Imuno-Histoquímica , Masculino
3.
J Chem Phys ; 151(3): 034903, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31325936

RESUMO

Combining experimental results obtained with X-ray scattering and field-gradient nuclear magnetic resonance (NMR) and an assessment of new and previous dielectric and rheology data, our study focuses on the molecular weight (Mw) evolution of local structure and dynamics in a homologous series of covalently bonded ionic liquids. Performed on a family of electrolytes with a tailored degree of ionic decoupling, this study reveals the differences between monomeric and oligomeric melts with respect to their structural organization, mass and charge transport, and molecular diffusion. Our study demonstrates that for the monomeric compound, the broadband conductivity and mechanical spectra reflect the same underlying distribution of activation barriers and that the Random Barrier Model describes fairly well both the ionic and structural relaxation processes in these materials. Moreover, the oligomers with chains comprising ten segments only exhibit both structural and dynamical fingerprints of a genuine polymer. A comparison of conductivity levels estimated using the self-diffusion coefficients probed via NMR and those probed directly with dielectric spectroscopy reveals the emerging of ion correlations which are affecting the macroscopic charge transport in these materials in a chain-length dependent manner.

4.
Clin Psychol Psychother ; 25(3): 465-473, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29430794

RESUMO

The Liebowitz Social Anxiety Scale (LSAS) is the most frequently used instrument to assess social anxiety disorder (SAD) in clinical research and practice. Both a self-reported (LSAS-SR) and a clinician-administered (LSAS-CA) version are available. The aim of the present study was to define optimal cut-off (OC) scores for remission and response to treatment for the LSAS in a German sample. Data of N = 311 patients with SAD were used who had completed psychotherapeutic treatment within a multicentre randomized controlled trial. Diagnosis of SAD and reduction in symptom severity according to the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, served as gold standard. OCs yielding the best balance between sensitivity and specificity were determined using receiver operating characteristics. The variability of the resulting OCs was estimated by nonparametric bootstrapping. Using diagnosis of SAD (present vs. absent) as a criterion, results for remission indicated cut-off values of 35 for the LSAS-SR and 30 for the LSAS-CA, with acceptable sensitivity (LSAS-SR: .83, LSAS-CA: .88) and specificity (LSAS-SR: .82, LSAS-CA: .87). For detection of response to treatment, assessed by a 1-point reduction in the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, rating, a reduction of 28% for the LSAS-SR and 29% for the LSAS-CA yielded the best balance between sensitivity (LSAS-SR: .75, LSAS-CA: .83) and specificity (LSAS-SR: .76, LSAS-CA: .80). To our knowledge, we are the first to define cut points for the LSAS in a German sample. Overall, the cut points for remission and response corroborate previously reported cut points, now building on a broader data basis.


Assuntos
Fobia Social/diagnóstico , Fobia Social/terapia , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Psicoterapia/métodos , Adulto , Feminino , Alemanha , Humanos , Masculino , Fobia Social/psicologia , Psicometria , Indução de Remissão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do Tratamento
5.
Pathologe ; 35(2): 191-5, 2014 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-23793289

RESUMO

Primary Hodgkin's lymphoma of the colon is exceedingly rare. We report on the case of a 74-year-old female patient presenting with weight loss and hematochezia. Proctocolonoscopy revealed a bleeding tumor localized in the right colonic flexure. Histological examination of initial mucosal biopsies could not verify malignancy; however, explorative surgery was decided in an interdisciplinary conference setting and right-sided hemicolectomy was performed. Macroscopically, a tumor measuring 5.5 cm in maximum diameter was found. By means of histology and immunohistochemistry the diagnosis of classic Hodgkin's lymphoma was made. Mesenteric lymph nodes were not affected and postoperative staging revealed no systemic spread. Therefore, the tumor fulfilled the criteria of a primary colonic Hodgkin's lymphoma. Diagnosis of primary colonic lymphoma can be difficult as clinical symptoms are typically unspecific and, as shown in this case, even primary biopsy histology can be falsely negative.


Assuntos
Neoplasias do Colo/patologia , Doença de Hodgkin/diagnóstico , Doença de Hodgkin/patologia , Idoso , Biópsia , Colectomia , Neoplasias do Colo/diagnóstico , Neoplasias do Colo/cirurgia , Colonoscopia , Reações Falso-Negativas , Feminino , Doença de Hodgkin/cirurgia , Humanos , Mucosa Intestinal/patologia , Linfonodos/patologia , Estadiamento de Neoplasias
6.
J Chem Phys ; 138(9): 094505, 2013 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-23485311

RESUMO

A previous dielectric, near-infrared (NIR), and nuclear magnetic resonance study on the hydrogen-bonded liquid 2-ethyl-1-hexanol [C. Gainaru et al., Phys. Rev. Lett. 107, 118304 (2011)] revealed anomalous behavior in various static quantities near 250 K. To check whether corresponding observations can be made for other monohydroxy alcohols as well, these experimental methods were applied to such substances with 5, 6, 7, 8, and 10 carbon atoms in their molecular backbone. All studied liquids exhibit a change of behavior near 250 K, which is tentatively ascribed to effects of hydrogen bond cooperativity. By analyzing the NIR band intensities, a linear cluster size is derived that agrees with estimates from dielectric spectroscopy. All studied alcohols, except 4-methyl-3-heptanol, display a dominant Debye-like peak. Furthermore, neat 2-ethyl-1-butanol exhibits a well resolved structural relaxation in its dielectric loss spectrum, which so far has only been observed for diluted monohydroxy alcohols.


Assuntos
Álcoois/química , Temperatura , Vidro/química , Espectroscopia de Luz Próxima ao Infravermelho
7.
J Chem Phys ; 139(13): 134503, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24116571

RESUMO

The relatively small dielectric Debye-like process of the monohydroxy alcohol 4-methyl-3-heptanol (4M3H) was found to depend slightly on the intramolecular conformation. Proton and deuteron nuclear magnetic resonance demonstrate that the hydroxyl dynamics and the overall molecular dynamics take place on similar time scales in contrast to the situation for the structural isomer 2-ethyl-1-hexanol (2E1H) [S. Schildmann et al., J. Chem. Phys. 135, 174511 (2011)]. This indicates a very weak decoupling of Debye-like and structural relaxation which was further probed using volume expansivity experiments. Shear viscosity as well as diffusometry measurements were performed and the data were analyzed in terms of the Debye-Stokes-Einstein equations. In mixtures of 4M3H with 2E1H the Debye-like process becomes much stronger and for 2E1H mole fraction of more than 25% the behavior of this alcohol is rapidly approached. This finding is interpreted to indicate that the ring-like supramolecular structures in 4M3H become energetically unfavorable when adding 2E1H, an alcohol that tends to form chain-like molecular aggregates. The concentration dependence of the Kirkwood factor in these mixtures displays a high degree of similarity with experimental results on monohydroxy alcohols in which the pressure or the location of the OH group within the molecular structure is varied.

8.
Med Sci Sports Exerc ; 55(11): 1968-1976, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37332229

RESUMO

PURPOSE: This study aimed to examine the injury and illness characteristics, treatments, and outcomes at elite ultraendurance triathlon events. METHODS: We quantified participant demographics, injury types, treatments, and disposition for medical encounters at 27 Ironman-distance triathlon championships from 1989 to 2019. We then calculated the likelihood of concurrent medical complaints in each encounter. RESULTS: We analyzed 10,533 medical encounters among 49,530 race participants for a cumulative incidence of 221.9/1000 participants (95% confidence interval [CI] = 217.7-226.2). Younger (<35 yr; 259.3/1000, 95% CI = 251.6-267.2) and older athletes (70+ yr; 254.0/1000, 95% CI = 217.8-294.4) presented to the medical tent at higher rates than middle-age adults (36-69 yr; 180.1/1000, 95% CI = 175.4-185.0). Female athletes also presented at higher rates when compared with males (243.9/1000, 95% CI = 234.9-253.2 vs 198.0/1000, 95% CI = 193.4-202.6). The most common complaints were dehydration (438.7/1000, 95% CI = 426.2-451.6) and nausea (400.4/1000, 95% CI = 388.4-412.6). Intravenous fluid was the most common treatment (483/1000; 95% CI = 469.8-496.4). Of the athletes who received medical care, 116.7/1000 (95% CI = 110.1-123.4) did not finish the race, and 17.1/1000 (95% CI = 14.7-19.8) required hospital transport. Athletes rarely presented with an isolated medical condition unless their injury was dermatologic or musculoskeletal in nature. CONCLUSIONS: Ultraendurance triathlon events have high rates of medical encounters among female athletes, as well as both younger and older age categories. Gastrointestinal and exertional-related symptoms are among the most common complaints. Intravenous infusions were the most common treatment after basic medical care. Most athletes entering the medical tent finished the race, and a small percentage were dispatched to the hospital. A more thorough understanding of common medical occurrences, including concurrent presentations and treatments, will allow for improved care and optimal race management.


Assuntos
Corrida , Natação , Adulto , Pessoa de Meia-Idade , Masculino , Humanos , Feminino , Ciclismo/lesões , Corrida/lesões , Resistência Física , Resultado do Tratamento
9.
Phys Rev Lett ; 107(11): 118304, 2011 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-22026709

RESUMO

Dielectric loss spectra covering 13 decades in frequency were collected for 2-ethyl-1-hexanol, a monohydroxy alcohol that exhibits a prominent Debye-like relaxation, typical for several classes of hydrogen-bonded liquids. The thermal variation of the dielectric absorption amplitude agrees well with that of the hydrogen-bond equilibrium population, experimentally mapped out using near infrared (NIR) and nuclear magnetic resonance (NMR) measurements. Despite this agreement, temperature-jump NIR spectroscopy reveals that the hydrogen-bond switching rate does not define the frequency position of the prominent absorption peak. This contrasts with widespread notions and models based thereon, but is consistent with a recent approach.

10.
Phys Rev Lett ; 105(25): 258303, 2010 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-21231631

RESUMO

Monohydroxy alcohols show a structural relaxation and at longer time scales a Debye-type dielectric peak. From spin-lattice relaxation experiments using different nuclear probes, an intermediate, slower-than-structural dynamics is identified for n-butanol. Based on these findings and on translational diffusion measurements, a model of self-restructuring, transient chains is proposed. The model is demonstrated to explain consistently the so-far puzzling observations made for this class of hydrogen-bonded glass forming liquids.

11.
Psychother Psychosom ; 78(1): 35-41, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18852500

RESUMO

This paper presents the Social Phobia Psychotherapy Research Network. The research program encompasses a coordinated group of studies adopting a standard protocol and an agreed-on set of standardized measures for the assessment and treatment of social phobia (SP). In the central project (study A), a multicenter randomized controlled trial, refined models of manualized cognitive-behavioral therapy and manualized short-term psychodynamic psychotherapy are compared in the treatment of SP. A sample of 512 outpatients will be randomized to either cognitive-behavioral therapy, short-term psychodynamic psychotherapy or waiting list. Assessments will be made at baseline, at the end of treatment and 6 and 12 months after the end of treatment. For quality assurance and treatment integrity, a specific project using highly elaborated measures has been established (project Q). Study A is complemented by 4 interrelated add-on projects focusing on attachment style (study B1), on cost-effectiveness (study B2), on variation in the serotonin transporter gene in SP (study C1) and on structural and functional deviations of the hippocampus and amygdala (study C2). Thus, the Social Phobia Psychotherapy Research Network program enables a highly interdisciplinary research into SP. The unique sample size achieved by the multicenter approach allows for studies of subgroups (e.g. comorbid disorders, isolated vs. generalized SP), of responders and nonresponders of each treatment approach, for generalization of results and for a sufficient power to detect differences between treatments. Psychological and biological parameters will be related to treatment outcome, and variables for differential treatment indication will be gained. Thus, the results provided by the network may have an important impact on the treatment of SP and on the development of treatment guidelines for SP.


Assuntos
Transtornos Fóbicos/terapia , Psicoterapia/métodos , Adolescente , Adulto , Idoso , Terapia Cognitivo-Comportamental , Análise Custo-Benefício , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Apego ao Objeto , Transtornos Fóbicos/diagnóstico , Transtornos Fóbicos/genética , Psicoterapia/economia , Ensaios Clínicos Controlados Aleatórios como Assunto , Adulto Jovem
12.
J Magn Reson ; 288: 84-94, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29438834

RESUMO

Polycrystalline dimethyl sulfone is studied using central-transition oxygen-17 exchange NMR. The quadrupolar and chemical shift tensors are determined by combining quantum chemical calculations with line shape analyses of rigid-lattice spectra measured for stationary and rotating samples at several external magnetic fields. Quantum chemical computations predict that the largest principal axes of the chemical shift anisotropy and electrical field gradient tensors enclose an angle of about 73°. This prediction is successfully tested by comparison with absorption spectra recorded at three different external magnetic fields. The experimental one-dimensional motionally narrowed spectra and the two-dimensional exchange spectrum are compatible with model calculations involving jumps of the molecules about their two-fold symmetry axis. This motion is additionally investigated by means of two-time stimulated-echo spectroscopy which allows for a determination of motional correlation functions over a wider temperature range than previously reported using carbon and deuteron NMR. On the basis of suitable second-order quadrupolar frequency distributions, sin-sin stimulated-echo amplitudes are calculated for a two-site model in the limit of vanishing evolution time and compared with experimental findings. The present study thus establishes oxygen-17 NMR as a powerful method that will be particularly useful for the study of solids and liquids devoid of nuclei governed by first-order anisotropies.

13.
Br J Health Psychol ; 12(Pt 4): 511-23, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17931470

RESUMO

Epidemiologic studies on hypochondriasis are very rare and have not been included in large North American community surveys until now. In order to gain information on the prevalence as well as the socio-demographic characteristics of hypochondriasis, the following community study was carried out. Analyses are based on an assessment of 1575 subjects selected by socio-demographic representation criteria for the German community. All subjects completed the Illness Attitude Scales (IAS) and responded to several additional questions on sociodemographics and diagnostic criteria pertaining to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) hypochondriasis. The IAS is internationally one of the best-established self-rating questionnaires for the assessment of hypochondriasis and health anxiety. Results reveal a 0.4% point prevalence rate of DSM-IV hypochondriasis. In contrast to that, 6% of the German population suffers from severe health anxiety. There are small positive effects for female gender, higher age and lower school education on health anxiety. Subjects with high health anxiety report a much lower health-related quality of life and a higher risk for a type of psychotherapeutic or psychiatric treatment. These results support the development of less restrictive criteria for hypochondriasis and place emphasis on the clinical and socio-economic relevance of health anxiety.


Assuntos
Ansiedade/epidemiologia , Hipocondríase/epidemiologia , Adolescente , Adulto , Idoso , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Autorrevelação , Inquéritos e Questionários
14.
Diabetes ; 42(1): 90-7, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8420822

RESUMO

In a model of congenic and intra-MHC recombinant rat strains, the differential role of various histocompatibility antigens in renal subcapsular transplantation of purified islets of Langerhans is evaluated. Class I MHC antigens of the RT1.A region, expressed on the endocrine cells of the islets themselves, do not induce graft rejection on their own. MHC class I antigens as encoded by the RT1.C region do not induce rejection either. MHC class II antigens as encoded by the RT1.B/D region are not expressed on the endocrine pancreas, not even during rejection. Although interstitial dendritic cells situated within the islets express these antigens, an isolated RT1.B/D incompatibility of islets is associated with prolonged survival in contrast to rapid rejection of fully MHC-mismatched grafts. Unlike other organs, islets matched for all MHC antigens, but incompatible at minor histocompatibility antigens, undergo rejection early after transplantation.


Assuntos
Diabetes Mellitus Experimental/cirurgia , Rejeição de Enxerto , Antígenos de Histocompatibilidade/imunologia , Transplante das Ilhotas Pancreáticas/imunologia , Animais , Transplante das Ilhotas Pancreáticas/patologia , Complexo Principal de Histocompatibilidade , Masculino , Ratos , Ratos Endogâmicos Lew , Ratos Endogâmicos , Especificidade da Espécie
15.
Diabetes ; 40(1): 134-40, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2015968

RESUMO

In inbred streptozocin-induced diabetic rats, the long-term function of different endocrine pancreatic isografts was compared. Isolated islets transplanted into the portal vein showed a progressive deterioration of function over time. In contrast, islets under the kidney capsule sustained a constant long-term function controlling all clinical signs of diabetes. Recipients of kidney subcapsular islets displayed normal growth rate, peripheral serum glucose and insulin levels, and metabolic parameters. However, their functional reserve was markedly reduced as revealed by diminished glucose tolerance and reduced insulin-secreting capacity after an intravenous glucose challenge. Vascularized whole-organ pancreatic grafts with portal venous drainage led to complete normalization of all parameters determined in this study. This study showed that the long-term function of islets transplanted under the kidney capsule is superior compared with islets transplanted into the portal vein.


Assuntos
Diabetes Mellitus Experimental/cirurgia , Transplante das Ilhotas Pancreáticas/fisiologia , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Teste de Tolerância a Glucose , Insulina/análise , Rim , Fígado , Masculino , Ratos , Ratos Endogâmicos Lew , Valores de Referência , Transplante Heterotópico
16.
J Am Coll Cardiol ; 15(1): 64-9, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2295743

RESUMO

To examine the functional consequences of the greater increase in right ventricular work with exercise, the effects of prolonged exercise on the right and left heart chambers were compared in 41 athletes before, at the finish (13 min) and after recovery (28 h) from the Hawaii Ironman Triathlon (3.9 km swim, 180.2 km bike ride, 42.2 km run). Two-dimensional and Doppler echocardiograms were analyzed for left and right atrial and ventricular areas at end-diastole and end-systole, right and left ventricular inflow velocities and mitral and tricuspid regurgitation. After exercise, left ventricular and left and right atrial sizes were reduced, whereas right ventricular size increased (diastole: 21.4 to 24.2 cm2; systole: 15.8 to 18.2 cm2; p less than 0.01). The emptying fraction of all chambers was unchanged. Left but not right ventricular inflow showed an increase in peak velocity of rapid filling, whereas both atrial systolic velocities increased (26 to 38 cm/s tricuspid; 38 to 54 cm/s mitral; both p less than 0.01). Overall, the right ventricular early to atrial velocity ratio was reduced after exercise (1.56 to 1.17; p less than 0.05) and the left ventricular pattern was unchanged. The prevalence of tricuspid regurgitation was statistically unchanged (86% to 52%), although that of mitral regurgitation was greatly reduced (76% to 0%). Changes in all variables returned toward prerace values during recovery. Thus, in highly trained athletes, prolonged exercise causes differing responses of the right and left ventricles. These differences may be due to changes in right ventricular function, shape or compliance.


Assuntos
Resistência Física/fisiologia , Esforço Físico/fisiologia , Função Ventricular , Adulto , Ciclismo , Circulação Coronária/fisiologia , Ecocardiografia , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Contração Miocárdica/fisiologia , Corrida , Volume Sistólico/fisiologia , Natação
17.
Arch Gen Psychiatry ; 47(8): 782-4, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2378549

RESUMO

To enhance diagnostic assessment in routine clinical care, the Munich Diagnostic Checklists have been developed for a systematic criteria-related evaluation of the most common psychiatric disorders according to DSM-III-R. Design, concept, and areas of application of the instrument are described. An initial test-retest study showed that satisfactory to excellent diagnostic agreement can be reached.


Assuntos
Transtornos Mentais/diagnóstico , Inventário de Personalidade , Adulto , Assistência Ambulatorial , Estudos de Avaliação como Assunto , Humanos , Transtornos Mentais/classificação , Escalas de Graduação Psiquiátrica , Psicometria
18.
J Phys Chem B ; 119(51): 15769-79, 2015 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-26606384

RESUMO

Alkylacetamide-based model peptides display an intense Debye-type dielectric relaxation. In order to explore the extent to which this feature has to be regarded analogous to that in other supramolecular liquids, notably the monohydroxy alcohols, we applied broadband dielectric, time-dependent solvation, and near-infrared spectroscopies as well as shear rheology and various nuclear magnetic resonance techniques to mixtures of N-methylacetamide (NMA) or N-ethylacetamide (NEA) with N-methylformamide. Compared in the modulus format, dielectric relaxation, solvation dynamics, and mechanical response indicate a common global and local dynamics. The present spin-relaxation measurements reflect motional processes which are significantly faster than the dominant Debye dielectric response, and a similar conclusion is drawn from measurements of the shear viscosity. The NH overtone stretching vibrations reveal a temperature-dependent hydrogen-bond equilibrium that changes its characteristics near temperatures of 325 K. Finally, dielectric low-temperature data recorded for (NEA)0.4(NMF)0.6 mixed with 2-picoline indicate the existence of a critical concentration akin to the situation in various monohydroxy alcohol mixtures.

19.
Eur J Cell Biol ; 78(11): 832-41, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10604660

RESUMO

Human gastric mucous cells - gastric cancer cell lines mucin gene expression - TNFalpha - RT-PCR immunocytochemistry Little is known on the expression pattern of mucin genes in human gastric cancer cell lines in relation to mucin expression in normal gastric epithelial cells. Thus, the aim of this study was to compare gastric cancer cell lines and non-transformed epithelial cells in their expression of the different mucin genes, in order to use these cells as models for physiological MUC expression in human stomach. Human gastric mucous cell primary cultures which were obtained from surgical specimen by collagenase/pronase treatment and a panel of six human gastric cancer cells were screened for mRNA expression of the mucin genes MUC1, MUC2, MUC5AC, MUC5B, and MUC6. Mucin gene expression was analyzed by semi-quantitative RT-PCR, and by Western blotting and immunocytochemistry. Primary cultured human gastric mucous cells retained the stomach-specific pattern of mRNA expression found in gastric mucosal biopsies (MUC1, MUC5AC, MUC6), whereas any gastric cancer cell line exhibited an aberrant mucin gene expression. Mucin gene expression showed large variations in levels and patterns from cell line to cell line, but MUC2 was aberrantly expressed in all cancer cells. Immunocytochemistry confirmed aberrant MUC2 protein expression in cancer cells. The expression of the secretory mucin genes MUC2 and MUC5AC varied in relation to the length of cultivation of the cancer cell lines. Treatment of the gastric cancer cells with TNFalpha resulted in an enhanced mRNA expression of MUC1, MUC2, and MUC5AC (2-fold increase within 3 hours; p <0.05). In contrast, immunocytochemistry disclosed a decrease in MUC2 and MUC5AC staining intensity. Our results indicate that primary cultured human gastric mucous cells provide a physiological in vitro system for investigations of gastric mucin gene regulation. In gastric cancer cells marked changes in the mucin gene expression pattern are found with coexpression of non-gastric type mucins. Gastric mucin gene expression may be regulated by proinflammatory cytokines which could have implications in gastritis.


Assuntos
Mucosa Gástrica/metabolismo , Regulação Neoplásica da Expressão Gênica , Mucinas/genética , Neoplasias Gástricas/genética , Processamento Alternativo , Sequência de Bases , Biópsia , Western Blotting , Células Epiteliais/metabolismo , Mucosa Gástrica/patologia , Humanos , Imuno-Histoquímica , Mucinas/metabolismo , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/metabolismo , Células Tumorais Cultivadas
20.
Am J Clin Nutr ; 45(3): 534-9, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3825980

RESUMO

Energy expenditure of four subjects was measured by the doubly-labelled-water (2H2 18O) method to determine if energy expenditure could be determined over short periods. Three subjects were studied while they performed 8 h of heavy exercise in a laboratory environment. Urine and blood samples were taken before and after exercise. Estimated energy expended during 8 h of high-intensity exercise (55% VO2 max) for three subjects was 757 +/- 118 kcal/h by the doubly-labelled-water method using urine and a two-point calculation, which compared favorably with 735 +/- 82 kcal/h obtained by respiratory gas exchange. For the fourth subject, daytime, nighttime, and daily energy expenditure was calculated by both the two-pair method and decay-curve analysis of urine and saliva samples collected in the morning and at night. Daytime and nighttime energy expenditures differed significantly (p less than 0.05).


Assuntos
Atividades Cotidianas , Metabolismo Energético , Esforço Físico , Sono/fisiologia , Adulto , Água Corporal/análise , Ritmo Circadiano , Deutério , Humanos , Masculino , Isótopos de Oxigênio
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