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1.
Eur J Neurol ; 27(1): 68-76, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31373417

RESUMEN

BACKGROUND AND PURPOSE: Assessment of the severity of chronic peripheral neuropathy during oxaliplatin treatment is based on symptoms. Efforts to adjust the total dose of oxaliplatin to prevent severe neuropathy can be complicated by the worsening of neuropathy symptoms following treatment. Objective measures of the structure and function of peripheral nerves during early phases of treatment may aid in determining the optimal oxaliplatin dose in individual patients. Intraepidermal nerve fibre density (IENFD) has been suggested as an early marker of peripheral neuropathy. METHODS: Sixty patients were examined before treatment and following 25% and 50% of the total planned oxaliplatin dose. Fifty-five of them were also examined at completion of chemotherapy and 6 months later. IENFD in skin biopsies from the distal leg, nerve conduction studies and quantitative sensory testing at the dorsum of the foot were performed. Forty-six healthy subjects were examined at baseline and after 6 and 52 weeks for comparison. RESULTS: Intraepidermal nerve fibre density was not reduced during treatment. Sural nerve amplitude and conduction velocity, vibration detection thresholds, mechanical detection threshold and cold detection threshold were significantly reduced during treatment. Compared to reference values and spontaneous changes in healthy subjects, the largest proportions of patients with deterioration were found for vibration detection thresholds followed by nerve conduction studies, mechanical detection threshold, cold detection threshold and IENFD. CONCLUSIONS: Significant changes were most pronounced for measures of large nerve fibre function, especially vibration sensation. Skin biopsies do not seem to provide a clinically relevant objective measure of peripheral nerve deterioration during oxaliplatin treatment.


Asunto(s)
Antineoplásicos/efectos adversos , Conducción Nerviosa/fisiología , Oxaliplatino/efectos adversos , Enfermedades del Sistema Nervioso Periférico/fisiopatología , Polineuropatías/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Biopsia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Fibras Nerviosas/patología , Examen Neurológico , Oxaliplatino/uso terapéutico , Enfermedades del Sistema Nervioso Periférico/inducido químicamente , Enfermedades del Sistema Nervioso Periférico/patología , Polineuropatías/inducido químicamente , Polineuropatías/patología , Piel/patología , Nervio Sural/patología , Nervio Sural/fisiopatología
2.
J Musculoskelet Neuronal Interact ; 17(2): 8-18, 2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28574407

RESUMEN

OBJECTIVE: Duchenne muscular dystrophy (DMD) patients are often treated with glucocorticoids; yet their precise molecular action remains unknown. METHODS: We investigated muscle biopsies from nine boys with DMD (aged: 7,6±2,8 yrs.) collected before and after three months of deflazacort treatment and compared them to eight healthy boys (aged: 5,3±2,4 yrs.). mRNA transcripts involved in activation of satellite cells, myogenesis, regeneration, adipogenesis, muscle growth and tissue inflammation were assessed. Serum creatine kinase (CK) levels and muscle protein expression by immunohistochemistry of selected targets were also analysed. RESULTS: Transcript levels for ADIPOQ, CD68, CDH15, FGF2, IGF1R, MYF5, MYF6, MYH8, MYOD, PAX7, and TNFα were significantly different in untreated patients vs. normal muscle (p⟨0.05). Linear tests for trend indicated that the expression levels of treated patients were approaching normal values (p⟨0.05) following treatment (towards an increase; CDH15, C-MET, DLK1, FGF2, IGF1R, MYF5, MYF6, MYOD, PAX7; towards a decrease: CD68, MYH8, TNFα). Treatment reduced CK levels (p⟨0.05), but we observed no effect on muscle protein expression. CONCLUSIONS: This study provides insight into the molecular actions of glucocorticoids in DMD at the mRNA level, and we show that multiple regulatory pathways are influenced. This information can be important in the development of new treatments.


Asunto(s)
Antiinflamatorios/uso terapéutico , Músculo Esquelético/efectos de los fármacos , Distrofia Muscular de Duchenne/tratamiento farmacológico , Pregnenodionas/uso terapéutico , Biopsia , Niño , Humanos , Masculino , Distrofia Muscular de Duchenne/patología , Transcriptoma/efectos de los fármacos
3.
Eur J Neurol ; 21(4): 623-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24460946

RESUMEN

BACKGROUND AND PURPOSE: Chemotherapy-induced peripheral neuropathy negatively affects the quality of life for many patients treated with oxaliplatin or docetaxel for gastrointestinal cancer or breast cancer. Symptoms can persist long after treatment and often include neuropathic pain. Our objective was to characterize the neuropathies with regard to symptoms, neurological signs and objective evidence of damage to the structure and function of the peripheral nerves. Furthermore, the diagnostic values of skin biopsy, quantitative sensory testing (QST) and nerve conduction studies (NCS) were compared. METHODS: Patients complaining of neuropathy symptoms at least 3 months after completion of treatment with oxaliplatin (n = 20) or docetaxel (n = 20) were recruited from the Department of Oncology or using hospital records. Neuropathy scores were determined along with the intraepidermal nerve fibre density in skin biopsies from the proximal and distal parts of the leg, QST and NCS. RESULTS: Clinically only sensory functions were affected. In general, neuropathy scores were higher in the oxaliplatin-treated group. Both sensory and motor fibres were affected in the NCS, showing predominantly signs of axonal damage. Mechanical detection threshold was most often affected in the QST. NCS, QTS and skin biopsy were abnormal in 11, 13 and 17 and 7, 11 and 15 of the oxaliplatin-treated patients and docetaxel-treated patients, respectively. CONCLUSIONS: Chemotherapy-induced peripheral neuropathy after oxaliplatin or docetaxel treatment is a clinically sensory, axonal neuropathy affecting only small nerve fibres in some patients. NCS are often normal, whereas QST and skin biopsy have a higher diagnostic sensitivity.


Asunto(s)
Antineoplásicos/efectos adversos , Conducción Nerviosa/fisiología , Compuestos Organoplatinos/efectos adversos , Polineuropatías , Sensación/fisiología , Piel/patología , Taxoides/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Docetaxel , Humanos , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Conducción Nerviosa/efectos de los fármacos , Oxaliplatino , Polineuropatías/inducido químicamente , Polineuropatías/patología , Polineuropatías/fisiopatología , Sensación/efectos de los fármacos
4.
J Physiol ; 591(15): 3789-804, 2013 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-23732643

RESUMEN

Recovery of skeletal muscle mass from immobilisation-induced atrophy is faster in young than older individuals, yet the cellular mechanisms remain unknown. We examined the cellular and molecular regulation of muscle recovery in young and older human subjects subsequent to 2 weeks of immobility-induced muscle atrophy. Retraining consisted of 4 weeks of supervised resistive exercise in 9 older (OM: mean age) 67.3, range 61-74 yrs) and 11 young (YM: mean age 24.4, range 21-30 yrs) males. Measures of myofibre area (MFA), Pax7-positive satellite cells (SCs) associated with type I and type II muscle fibres, as well as gene expression analysis of key growth and transcription factors associated with local skeletal muscle milieu, were performed after 2 weeks immobility (Imm) and following 3 days (+3d) and 4 weeks (+4wks) of retraining. OM demonstrated no detectable gains in MFA (vastus lateralis muscle) and no increases in number of Pax7-positive SCs following 4wks retraining, whereas YM increased their MFA (P < 0.05), number of Pax7-positive cells, and had more Pax7-positive cells per type II fibre than OM at +3d and +4wks (P < 0.05). No age-related differences were observed in mRNA expression of IGF-1Ea, MGF, MyoD1 and HGF with retraining, whereas myostatin expression levels were more down-regulated in YM compared to OM at +3d (P < 0.05). In conclusion, the diminished muscle re-growth after immobilisation in elderly humans was associated with a lesser response in satellite cell proliferation in combination with an age-specific regulation of myostatin. In contrast, expression of local growth factors did not seem to explain the age-related difference in muscle mass recovery.


Asunto(s)
Envejecimiento/fisiología , Inmovilización/fisiología , Músculo Esquelético/fisiología , Atrofia Muscular/fisiopatología , Mioblastos/fisiología , Adulto , Anciano , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Femenino , Factor de Crecimiento de Hepatocito/genética , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Masculino , Persona de Mediana Edad , Proteína MioD/genética , Miostatina/genética , Factor de Transcripción PAX7/genética , Proteínas Proto-Oncogénicas c-met/genética , ARN Mensajero/metabolismo , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Factor de Transcripción STAT5/genética , Proteínas Supresoras de Tumor/genética , Adulto Joven
5.
Br J Cancer ; 108(3): 715-20, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23322196

RESUMEN

BACKGROUND: Laboratory studies and a single case-control study have suggested a protective effect of statins on the risk of glioma. We wished to investigate the influence of statin use on the risk of glioma in a population-based setting. METHODS: We conducted a nationwide case-control study in Denmark based on population-based medical registries. We identified all patients aged 20 to 85 years with a first diagnosis of histologically verified glioma during 2000-2009. These cases were matched on birth year and sex with population controls. Prior use of statins since 1995 was classified into short-term use (<5 years) and long-term use (5+ years). We used conditional logistic regression to compute odds ratios (ORs), with 95% confidence intervals (CIs), for glioma associated with statin use, adjusted for potential confounders. RESULTS: A total of 2656 cases and 18,480 controls were included in the study. The risk of glioma was reduced among long-term statin users (OR=0.76; 95% CI: 0.59-0.98) compared with never users of statins, and was inversely related to the intensity of statin treatment among users (OR=0.71; 95% CI: 0.44-1.15 for highest intensity). The inverse association between long-term statin treatment and glioma risk was more pronounced among men aged ≤ 60 years (OR=0.40; 95% CI: 0.17-0.91) compared with men aged 60+ years (OR=0.71; 95% CI: 0.49-1.03). An inverse association was also observed among women aged ≤ 60 years (OR=0.28; 95% CI: 0.06-1.25), but not among women over age 60 years (OR=1.23; 95% CI: 0.82-1.85). CONCLUSION: Long-term statin use may reduce the risk of glioma.


Asunto(s)
Neoplasias Encefálicas/prevención & control , Glioma/prevención & control , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/epidemiología , Estudios de Casos y Controles , Dinamarca/epidemiología , Femenino , Estudios de Seguimiento , Glioma/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Tasa de Supervivencia , Adulto Joven
6.
J Physiol ; 587(Pt 14): 3679-90, 2009 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-19470780

RESUMEN

In vitro experiments indicate a non-metabolic role of muscle glycogen in contracting skeletal muscles. Since the sequence of events in excitation\#8211;contraction (E\#8211;C) coupling is known to be located close to glycogen granules, at specific sites on the fibre, we hypothesized that the distinct compartments of glycogen have specific effects on muscle fibre contractility and fatigability. Single skeletal muscle fibres (n = 19) from fed and fasted rats were mechanically skinned and divided into two segments. In one segment glycogen localization and volume fraction were estimated by transmission electron microscopy. The other segment was mechanically skinned and, in the presence of high and constant myoplasmic ATP and PCr, electrically stimulated (10 Hz, 0.8 s every 3 s) eliciting repeated tetanic contractions until the force response was decreased by 50% (mean +/- S.E.M., 81 +/- 16, range 22-252 contractions). Initially the total myofibrillar glycogen volume percentage was 0.46 +/- 0.07%, with 72 +/- 3% in the intermyofibrillar space and 28 +/- 3% in the intramyofibrillar space. The intramyofibrillar glycogen content was positively correlated with the fatigue resistance capacity (r(2) = 0.32, P = 0.02). Intermyofibrillar glycogen was inversely correlated with the half-relaxation time in the unfatigued tetanus (r(2) = 0.25, P = 0.03). These results demonstrate for the first time that two distinct subcellular populations of glycogen have different roles in contracting single muscle fibres under conditions of high myoplasmic ATP.


Asunto(s)
Glucógeno/metabolismo , Contracción Muscular/fisiología , Fatiga Muscular/fisiología , Fibras Musculares Esqueléticas/fisiología , Resistencia Física/fisiología , Animales , Células Cultivadas , Masculino , Ratas , Ratas Sprague-Dawley , Distribución Tisular
7.
Andrology ; 6(4): 547-555, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29656500

RESUMEN

Low testosterone levels in aging men are associated with insulin resistance. Mitochondrial dysfunction, changes in glycogen metabolism, and lipid accumulation are linked to insulin resistance in skeletal muscle. In this randomized, double-blinded, placebo-controlled study, we investigated the effects of six-month testosterone replacement therapy (TRT) and strength training (ST) on mitochondrial, glycogen, and lipid droplet (LD) content in skeletal muscle of aging men with subnormal bioavailable testosterone (BioT) levels. Mitochondrial, glycogen, and LD volume fractions in muscle biopsies were estimated by transmission electron microscopy. Insulin sensitivity (insulin-stimulated Rd) and body composition were assessed by euglycemic-hyperinsulinemic clamp and dual X-ray absorptiometry, respectively. TRT significantly increased total testosterone levels, BioT, and lean body mass (LBM) (p < 0.05), whereas percent body fat decreased (p < 0.05), and insulin sensitivity was unchanged. Baseline mitochondrial volume fraction correlated inversely with percent body fat (ρ = -0.43; p = 0.003). Δ-mitochondrial fraction correlated positively with Δ-total testosterone (ρ = 0.70; p = 0.02), and Δ-glycogen fraction correlated inversely with Δ-LBM (ρ = -0.83; p = 0.002) during six-month TRT, but no significant changes were observed in mitochondrial, glycogen, and LD volume fractions during TRT and ST. In conclusion, in this exploratory small-scale study, the beneficial effects of six-month TRT on total testosterone, LBM, and percent body fat were not followed by significant changes in fractions of mitochondria, glycogen, or lipid in skeletal muscle of aging men with lowered testosterone levels. Six-month ST or combined three-month ST+TRT did not change intramyocellular mitochondria, glycogen, and LD fractions compared to placebo. However, further studies with a larger sample size are needed.


Asunto(s)
Terapia de Reemplazo de Hormonas , Mitocondrias/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Entrenamiento de Fuerza , Testosterona/uso terapéutico , Anciano , Envejecimiento , Composición Corporal/efectos de los fármacos , Método Doble Ciego , Glucógeno , Humanos , Resistencia a la Insulina , Gotas Lipídicas/efectos de los fármacos , Masculino , Persona de Mediana Edad
8.
Mol Biol Cell ; 12(4): 1147-60, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11294913

RESUMEN

Deletion of the yeast gene ACB1 encoding Acb1p, the yeast homologue of the acyl-CoA-binding protein (ACBP), resulted in a slower growing phenotype that adapted into a faster growing phenotype with a frequency >1:10(5). A conditional knockout strain (Y700pGAL1-ACB1) with the ACB1 gene under control of the GAL1 promoter exhibited an altered acyl-CoA profile with a threefold increase in the relative content of C18:0-CoA, without affecting total acyl-CoA level as previously reported for an adapted acb1Delta strain. Depletion of Acb1p did not affect the general phospholipid pattern, the rate of phospholipid synthesis, or the turnover of individual phospholipid classes, indicating that Acb1p is not required for general glycerolipid synthesis. In contrast, cells depleted for Acb1p showed a dramatically reduced content of C26:0 in total fatty acids and the sphingolipid synthesis was reduced by 50-70%. The reduced incorporation of [(3)H]myo-inositol into sphingolipids was due to a reduced incorporation into inositol-phosphoceramide and mannose-inositol-phosphoceramide only, a pattern that is characteristic for cells with aberrant endoplasmic reticulum to Golgi transport. The plasma membrane of the Acb1p-depleted strain contained increased levels of inositol-phosphoceramide and mannose-inositol-phosphoceramide and lysophospholipids. Acb1p-depleted cells accumulated 50- to 60-nm vesicles and autophagocytotic like bodies and showed strongly perturbed plasma membrane structures. The present results strongly suggest that Acb1p plays an important role in fatty acid elongation and membrane assembly and organization.


Asunto(s)
Proteínas Portadoras/fisiología , Proteínas Fúngicas/fisiología , Esfingolípidos/biosíntesis , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Membrana Celular , Inhibidor de la Unión a Diazepam , Ácidos Grasos/biosíntesis , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fosfatidiletanolaminas/biosíntesis , Fosfatidilinositoles/biosíntesis , Fosfatidilserinas/biosíntesis , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiología
9.
J Neurodegener Dis ; 2017: 1436519, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28596929

RESUMEN

OBJECTIVES: The present study aimed to explore the effect of resistance training in patients with amyotrophic lateral sclerosis (ALS), a disease characterized by progressive motor neuron loss and muscle weakness. MATERIALS AND METHODS: Following a 12-week "lead-in" control period, a population of ALS patients from Funen, Denmark, completed a 12-week resistance training program consisting of 2-3 sessions/week. Neuromuscular function (strength and power) and voluntary muscle activation (superimposed twitch technique) were evaluated before and after both control and training periods. Physical capacity tests (chair rise and timed up and go), the revised ALS functional rating scale (ALSFRS-R) scores, and muscle cross sectional area (histology) were also assessed. RESULTS: Of twelve ALS patients assessed for eligibility, six were included and five completed the study. Training did not significantly affect the ALSFRS-R score, and loss of neuromuscular function (strength and power) increased following the training period. However, an improved functionality (chair rise) and an increase in greatly hypertrophied type II fibres combined with an increase in atrophied fibres following the training period compared to the control period were observed. CONCLUSION: In this small study, the present form of resistance training was unable to attenuate progressive loss of neuromuscular function in ALS, despite some changes in physical capacity and morphology.

10.
Cancer Res ; 60(6): 1704-10, 2000 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-10749143

RESUMEN

The gene deleted in malignant brain tumors 1 (DMBT1) has been proposed as a candidate tumor suppressor for brain, gastrointestinal, and lung cancer. It codes for a protein of unknown function belonging to the superfamily of scavenger receptor cysteine-rich proteins. We aimed at getting insights into the functions of DMBT1 by expression analyses and studies with a monoclonal antibody against the protein. The DMBT1 mRNA is expressed throughout the immune system, and Western blot studies demonstrated that isoforms of DMBT1 are identical to the collectin-binding protein gp-340, a glycoprotein that is involved in the respiratory immune defense. Immunohistochemical analyses revealed that DMBT1 is produced by both tumor-associated macrophages and tumor cells and that it is deregulated in glioblastoma multiforme in comparison to normal brain tissue. Our data further suggest that the proteins CRP-ductin and hensin, both of which have been implicated in epithelial differentiation, are the DMBT1 orthologs in mice and rabbits, respectively. These findings and the spatial and temporal distribution of DMBT1 in fetal and adult epithelia suggest that DMBT1 further plays a role in epithelial development. Rearrangements of DMBT1 were found in 16 of 18 tumor cell lines, and hemizygous deletions were observed in a subset of normal individuals, indicating that the alterations in tumors may be a result of both pre-existing deletions uncovered by a loss of heterozygosity and secondary changes acquired during tumorigenesis. Thus, DMBT1 is a gene that is highly unstable in cancer and encodes for a protein with at least two different functions, one in the immune defense and a second one in epithelial differentiation.


Asunto(s)
Aglutininas , Células Epiteliales/metabolismo , Sistema Inmunológico/metabolismo , Neoplasias/genética , Receptores de Superficie Celular/genética , Encéfalo/metabolismo , Química Encefálica , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , Proteínas de Unión al Calcio , Diferenciación Celular/genética , Proteínas de Unión al ADN , Células Epiteliales/citología , Regulación de la Expresión Génica , Células HL-60 , Humanos , Inmunohistoquímica , Células Jurkat , Pérdida de Heterocigocidad , Neoplasias/patología , Polimorfismo Genético , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Receptores de Superficie Celular/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Distribución Tisular , Células Tumorales Cultivadas , Proteínas Supresoras de Tumor , Células U937
11.
Biomed Res Int ; 2016: 5930621, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27195289

RESUMEN

Muscle weakness is considered the pivotal sign of amyotrophic lateral sclerosis (ALS). Knowledge about the skeletal muscle degeneration/regeneration process and the myogenic potential is limited in ALS patients. Therefore, we investigate these processes in a time course perspective by analysing skeletal muscle biopsies from ALS patients collected before and after a 12-week period of normal daily activities and compare these with healthy age-matched control tissue. We do this by evaluating mRNA and protein (immunohistochemical) markers of regeneration, neurodegeneration, myogenesis, cell cycle regulation, and inflammation. Our results show morphological changes indicative of active denervation and reinnervation and an increase in small atrophic fibres. We demonstrate differences between ALS and controls in pathways controlling skeletal muscle homeostasis, cytoskeletal and regenerative markers, neurodegenerative factors, myogenic factors, cell cycle determinants, and inflammatory markers. Our results on Pax7 and MyoD protein expression suggest that proliferation and differentiation of skeletal muscle stem cells are affected in ALS patients, and the myogenic processes cannot overcome the denervation-induced wasting.


Asunto(s)
Esclerosis Amiotrófica Lateral/fisiopatología , Inflamación/genética , Desarrollo de Músculos/genética , Proteína MioD/biosíntesis , Factor de Transcripción PAX7/biosíntesis , Anciano , Biopsia , Proteínas de Ciclo Celular/biosíntesis , Proteínas de Ciclo Celular/genética , Diferenciación Celular/genética , Regulación del Desarrollo de la Expresión Génica , Voluntarios Sanos , Humanos , Inflamación/patología , Inflamación/fisiopatología , MicroARNs/biosíntesis , MicroARNs/genética , Persona de Mediana Edad , Músculo Esquelético/inervación , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatología , Proteína MioD/genética , Factor de Transcripción PAX7/genética , Regeneración/genética , Células Madre/metabolismo
12.
Biochim Biophys Acta ; 1537(3): 211-21, 2001 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-11731223

RESUMEN

There is no consensus regarding the results from in vivo and in vitro studies on the impact of chronic high insulin and/or high glucose exposure on acute insulin stimulation of glycogen synthase (GS) kinetic parameters in human skeletal muscle. The aim of this study was to evaluate the kinetic parameters of glycogen synthase activity in human myotube cultures at conditions of chronic high insulin combined or not with high glucose exposure, before and after a subsequent acute insulin stimulation. Acute insulin stimulation significantly increased the fractional activity (FV(0.1)) of GS, increased the sensitivity of GS to the allosteric activator glucose 6-phosphate (A(0.5)) and increased the sensitivity of GS to its substrate UDPG (K(m(0.1))) when myotubes were precultured at low insulin with/without high glucose conditions. However, this effect of acute insulin stimulation was abolished in myotubes precultured at high insulin with or without high glucose. Furthermore, we found significant correlations between the fractional velocities FV(0.1) of GS and K(m(0.1)) (rho=-0.72, P<0.0001), between FV(0.1) and A(0.5) (rho=-0.82, P<0.0001) and between K(m(0.1)) and A(0.5) values (rho=0.71, P<0.0001). Our results show that chronic exposure of human myotubes to high insulin with or without high glucose did not affect the basal kinetic parameters but abolished the reactivity of GS to acute insulin stimulation. We suggest that insulin induced insulin resistance of GS is caused by a failure of acute insulin stimulation to decrease A(0.5) and K(m(0.1)) in human skeletal muscle.


Asunto(s)
Glucógeno Sintasa/metabolismo , Insulina/farmacología , Fibras Musculares Esqueléticas/metabolismo , Biopsia , Células Cultivadas , Glucosa/farmacología , Glucógeno/metabolismo , Humanos , Inmunohistoquímica , Resistencia a la Insulina , Cinética , Fibras Musculares Esqueléticas/efectos de los fármacos , Miosinas/metabolismo
13.
Diabetes ; 50(6): 1324-9, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11375332

RESUMEN

To gain further insight into the mechanisms underlying muscle insulin resistance, the influence of obesity and type 2 diabetes on GLUT4 immunoreactivity in slow and fast skeletal muscle fibers was studied. Through a newly developed, very sensitive method using immunohistochemistry combined with morphometry, GLUT4 density was found to be significantly higher in slow compared with fast fibers in biopsy specimens from lean and obese subjects. In contrast, in type 2 diabetic subjects, GLUT4 density was significantly lower in slow compared with fast fibers. GLUT4 density in slow fibers from diabetic patients was reduced by 9% compared with the weight-matched obese subjects and by 18% compared with the lean control group. The slow-fiber fraction was reduced to 86% in the obese subjects and to 75% in the diabetic subjects compared with the control group. Estimated GLUT4 contribution from slow fibers was reduced to 77% in the obese subjects and to 61% in type 2 diabetic patients compared with the control subjects. We propose that a reduction in the fraction of slow-twitch fibers, combined with a reduction in GLUT4 expression in slow fibers, may reduce the insulin-sensitive GLUT4 pool in type 2 diabetes and thus contribute to skeletal muscle insulin resistance.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Proteínas de Transporte de Monosacáridos/metabolismo , Fibras Musculares de Contracción Lenta/metabolismo , Proteínas Musculares , Adulto , Western Blotting , Diabetes Mellitus Tipo 2/fisiopatología , Transportador de Glucosa de Tipo 4 , Humanos , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Fibras Musculares de Contracción Rápida/metabolismo , Obesidad/metabolismo , Valores de Referencia
14.
Biomed Res Int ; 2015: 265278, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25853139

RESUMEN

Trapezius myalgia is the most common type of chronic neck pain. While physical exercise reduces pain and improves muscle function, the underlying mechanisms remain unclear. Nitric oxide (NO) signaling is important in modulating cellular function, and a dysfunctional neuronal NO synthase (nNOS) may contribute to an ineffective muscle function. This study investigated nNOS expression and localization in chronically painful muscle. Forty-one women clinically diagnosed with trapezius myalgia (MYA) and 18 healthy controls (CON) were included in the case-control study. Subsequently, MYA were randomly assigned to either 10 weeks of specific strength training (SST, n = 18), general fitness training (GFT, n = 15), or health information (REF, n = 8). Distribution of fiber type, cross-sectional area, and sarcolemmal nNOS expression did not differ between MYA and CON. However, MYA showed increased sarcoplasmic nNOS localization (18.8 ± 12 versus 12.8 ± 8%, P = 0.049) compared with CON. SST resulted in a decrease of sarcoplasm-localized nNOS following training (before 18.1 ± 12 versus after 12.0 ± 12%; P = 0,027). We demonstrate that myalgic muscle displays altered nNOS localization and that 10 weeks of strength training normalize these disruptions, which supports previous findings of impaired muscle oxygenation during work tasks and reduced pain following exercise.


Asunto(s)
Ejercicio Físico/fisiología , Músculo Esquelético/metabolismo , Enfermedades Musculares/fisiopatología , Mialgia/metabolismo , Mialgia/fisiopatología , Óxido Nítrico Sintasa de Tipo I/metabolismo , Adulto , Estudios de Casos y Controles , Dolor Crónico/metabolismo , Dolor Crónico/fisiopatología , Femenino , Humanos , Persona de Mediana Edad , Músculo Esquelético/fisiopatología , Enfermedades Musculares/metabolismo , Dolor de Cuello/metabolismo , Dolor de Cuello/fisiopatología , Óxido Nítrico/metabolismo , Entrenamiento de Fuerza/métodos , Músculos Superficiales de la Espalda/metabolismo
15.
J Invest Dermatol ; 116(5): 702-12, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11348458

RESUMEN

Peroxisome proliferator-activated receptors (PPARs) are pleiotropic regulators of growth and differentiation of many cell types. We have performed a comprehensive analysis of the expression of PPARs, transcriptional cofactors, and marker genes during differentiation of normal human keratinocytes using a combination of reverse transcriptase polymerase chain reaction, Northern and Western blotting, and immunohistochemistry. PPARdelta was the predominant PPAR subtype in human keratinocytes and highly expressed in basal cells and suprabasal cells. Induction of PPARalpha and PPARgamma expression was linked to differentiation, and accordingly, expression of PPARalpha and PPARgamma was in essence confined to suprabasal cells. Differentiation was not accompanied by significant changes in the expression of the coactivators CREB-binding protein, p300, steroid receptor coactivator 1, or the corepressors nuclear receptor corepressor and silence mediator for retinoid and thyroid hormone receptors. We critically evaluated the effects of selective PPAR ligands and a synthetic fatty acid analog, tetradecylthioacetic acid. Tetradecylthioacetic acid activated all human PPAR subtypes in the ranking order PPARdelta >> PPARalpha > PPARgamma. All selective PPAR ligands marginally induced transglutaminase-1 expression with the PPARdelta-selective ligand L165041 being the most potent. The PPARalpha- and PPARgamma-selective ligands Wy14643 and BRL49653 had negligible effect on involucrin expression, whereas a dose-dependent induction was observed with L165041. Simultaneous addition of L165041 and BRL49653 synergistically induced strong involucrin expression. Additionally, L165041 potently induced CD36 mRNA expression. Administration of tetradecylthioacetic acid resulted in a dramatic decrease in proliferation and a robust upregulation of the expression of involucrin and transglutaminase. Our results indicate that tetradecylthioacetic acid may affect keratinocyte gene expression and differentiation via PPAR-dependent and PPAR-independent pathways, and that the latter play an important role.


Asunto(s)
Expresión Génica/efectos de los fármacos , Queratinocitos/citología , Queratinocitos/fisiología , Receptores Citoplasmáticos y Nucleares/metabolismo , Sulfuros/farmacología , Factores de Transcripción/metabolismo , Adulto , Diferenciación Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Células Cultivadas , Epidermis/metabolismo , Marcadores Genéticos , Humanos , Inmunohistoquímica , Ligandos , Isoformas de Proteínas/fisiología , Receptores Citoplasmáticos y Nucleares/fisiología , Factores de Transcripción/fisiología , Activación Transcripcional/fisiología
16.
J Neuropathol Exp Neurol ; 53(3): 272-5, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8176410

RESUMEN

A stereological estimation of nuclear volume in recurrent and non-recurrent meningiomas was made. The aim was to investigate whether this method could discriminate between these two groups. We found that the mean nuclear volumes in recurrent meningiomas were all larger at debut than in any of the control tumors. The mean nuclear volume of the individual recurrent tumors appeared to change with time, showing a tendency to diminish. A relationship between large nuclear volume at presentation and number of or time interval between recurrences was not found. We conclude that measurement of mean nuclear volume in meningiomas might help identify a group at risk of recurrence.


Asunto(s)
Neoplasias Meníngeas/patología , Meningioma/patología , Recurrencia Local de Neoplasia/patología , Adulto , Anciano , Núcleo Celular/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
J Clin Endocrinol Metab ; 86(11): 5465-70, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11701723

RESUMEN

Immunohistochemical analysis of the distribution of human fetal antigen 1 (FA1) in adult human tissues has demonstrated a strong association between FA1 and (neuro)endocrine structures. In the anterior pituitary gland FA1 was colocalized with GH, and the present study was performed to evaluate a possible relationship between GH and FA1. FA1 and GH levels were measured during a 24-h period at 20-min intervals. In contrast to the known GH peaks during 24-h sampling, there was no detectable FA1 peak. The FA1 responses to placebo were not significantly different from the responses to the combination of pyridostigmine and GHRH. No significant difference was found between basal FA1 (nanograms per ml) levels [median (minimum-maximum)] in healthy adults [n = 40; 28.6 ng/ml (12.5-72.0)], acromegalic patients [n = 11; 31.0 ng/ml (21.6-56.3)], and patients with GH deficiency [n = 22; 32.1 ng/ml (13.4-108.7)]. FA1 levels were significantly reduced, in the six of seven acromegalic GH responders to octreotide, from [median (minimum-maximum)] 30.6 ng/ml (20.0-43.1) to 20.3 (13.9-30.2; P < 0.02). There was no significant change during placebo. FA1 levels were significantly increased compared with placebo values during 3 months of GH therapy. The increase in FA1 levels was significantly higher than the change during placebo (P < 0.003). In conclusion, a common secretory and stimulatory pathway for FA1 and GH in healthy adults has been ruled out. However, we found that pharmacologically induced changes in GH levels during weeks to months had a corresponding direct or indirect effect on FA1 levels in patients with GH deficiency or acromegaly. However, a direct effect of octreotide on FA1 levels, independent of GH levels, has not been ruled out.


Asunto(s)
Glicoproteínas/metabolismo , Hormona de Crecimiento Humana/sangre , Enfermedades de la Hipófisis/metabolismo , Acromegalia/sangre , Adulto , Ritmo Circadiano , Ensayo de Inmunoadsorción Enzimática , Femenino , Hormona Liberadora de Gonadotropina/deficiencia , Hormona Liberadora de Gonadotropina/metabolismo , Hormonas/farmacología , Humanos , Inmunohistoquímica , Octreótido/farmacología , Enfermedades de la Hipófisis/patología , Bromuro de Piridostigmina/farmacología , Valores de Referencia
18.
J Comp Neurol ; 217(2): 176-86, 1983 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-6886051

RESUMEN

The distribution of cholecystokinin in the spinal cord was investigated by immunohistochemistry. Throughout the length of the spinal cord cholecystokinin immunoreactivity was found in laminae I and II, in the spinal reticular nucleus, and in the surroundings of the central canal. On the basis of the cholecystokinin pattern lamina II could be divided into a dorsal and ventral part. In the lumbar and sacral spinal cord additional terminal fields of cholecystokinin immunoreactive boutons unique to these levels were found. They corresponded to the intermediolateral nucleus and to the medial lumbar sympathetic nucleus dorsal to the central canal in the first and second lumbar segment. Also the intermediolateral nucleus in L6-S1 received a dense cholecystokinin positive input. Moreover, the area surrounding the central canal in L6-S1 contained many cholecystokinin immunoreactive structures. Combined retrograde tracing and immunocytochemistry revealed that the two cholecystokinin terminal fields characteristic for L1-L2 and that surrounding the intermediolateral nucleus in L6-S1 were situated corresponding to preganglionic neurons innervating pelvic organs through the hypogastric nerve or the pelvic nerves. It thus appears that the unique lumbosacral cholecystokinin is related to nuclei influencing pelvic structures, pointing to a special need for regulation of the organs involved in evacuation and sexual functions. Moreover, it is demonstrated that the caudal part of the spinal sympathetic system differs from the more cranial part with respect to type of afferent connections. The origin of the spinal cholecystokinin was investigated and it was found that neither complete transection of the spinal cord nor ipsilateral sectioning of three or four dorsal roots induced visible changes in the cholecystokinin staining pattern. Treatment of the caudal spinal cord with colchicine revealed the presence of cholecystokinin immunoreactive neurons in the intermediate gray, at the lateral border of the dorsal horn, in the dorsal horn proper, and in the substantia gelatinosa. These findings indicate that the majority of spinal cholecystokinin has a spinal origin.


Asunto(s)
Colecistoquinina/metabolismo , Ganglios Autónomos/metabolismo , Pelvis/inervación , Médula Espinal/metabolismo , Animales , Fibras Autónomas Posganglionares/metabolismo , Fibras Autónomas Preganglionares/metabolismo , Ratas , Ratas Endogámicas , Sustancia Gelatinosa/metabolismo
19.
J Comp Neurol ; 223(3): 400-14, 1984 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-6142909

RESUMEN

The distribution of somatostatin in the rat spinal cord was studied immunohistochemically with particular reference to the localization in the caudal centers that innervate the pelvic organs. For detailed studies of the laminar distribution of somatostatin the combination of immunohistochemistry and acetylcholinesterase enzyme histochemistry was employed. Deafferentation experiments were carried out to shed light on the origin of the somatostatin-containing axons. These experiments showed that the bulk of the spinal somatostatin has a spinal origin. The structures showing somatostatin immunoreactivity formed a distinct and detailed pattern. The marginal layer and particularly the substantia gelatinosa contained a dense immunoreactivity in terminallike structures. Such structures were also found in the reticular nucleus, along the medial border of the dorsal horn, and in the nucleus of the dorsolateral funiculus. In all of these regions somatostatin-positive cell bodies were also observed. In the intermediate gray matter stained terminals were present around the central canal in a varying number. The most prominent stainability was found in the lumbosacral transition zone. Many terminals were also observed in the sacral parasympathetic intermediolateral nucleus. In contrast, very few appeared in the sympathetic nuclei. Immunoreactive somata were present in the surroundings of the central canal at all levels. Moreover, positive neurons were found in the intermediolateral nucleus of the sacral cord. By combined retrograde tracing and immunohistochemistry the existence of somatostatin-containing parasympathetic visceromotoneurons was ascertained. Corresponding to this, somatostatin-positive terminals were seen in the major pelvic ganglion. The ventral horn generally contained few terminals, and the density was particularly low in the motoneuron neuropil. However, a dense somatostatin network was found in the sixth lumbar segment in relation to the neurons in Onuf's nucleus X complex, the nucleus that innervates the small pelvic muscles including the striated sphincters. It is concluded that somatostatin, besides being involved in the processing of sensory input, serves an important motor task, that of taking part in the complex control of the pelvic organs and their associated striated muscles.


Asunto(s)
Pelvis/inervación , Somatostatina/fisiología , Médula Espinal/fisiología , Animales , Femenino , Técnica del Anticuerpo Fluorescente , Histocitoquímica , Inmunoquímica , Técnicas para Inmunoenzimas , Masculino , Neuronas/análisis , Ratas , Ratas Endogámicas , Somatostatina/análisis , Médula Espinal/análisis , Distribución Tisular
20.
J Comp Neurol ; 186(3): 439-50, 1979 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-88463

RESUMEN

Spinal cord motoneuron neuropil (cervical and lumbar enlargements) has been studied at the ultrastructural level after fixation with glutaraldehyde and staining with uranyl acetate and lead citrate. Based on the appearance of the synaptic specializations, different types of boutons were identified and correlated with the classification of bouton types based on osmicated tissue. The sulfide silver method for histochemical demonstration of heavy metals was applied to the same region. The localization of reaction products (silver grains) was predominantly in the terminals. Within the bouton, the grains were mainly in the specialized region of the synaptic contact, and the presynaptic network has also labelled, but to a lesser degree. All stained boutons had the same type of paramembranous synaptic specialization, but not all of the boutons with this type of specialization were stained. The stained boutons are interpreted as a fraction of the 'F' boutons.


Asunto(s)
Metales/metabolismo , Neuronas Motoras/ultraestructura , Médula Espinal/citología , Animales , Histocitoquímica/métodos , Microscopía Electrónica , Neuronas Motoras/metabolismo , Ratas , Plata , Médula Espinal/metabolismo , Coloración y Etiquetado , Sulfuros , Sinapsis/metabolismo , Sinapsis/ultraestructura
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