RESUMO
The German Society of Pneumology initiated 2021 the AWMF S1 guideline Long COVID/Post-COVID. In a broad interdisciplinary approach, this S1 guideline was designed based on the current state of knowledge.The clinical recommendations describe current Long COVID/Post-COVID symptoms, diagnostic approaches, and therapies.In addition to the general and consensus introduction, a subject-specific approach was taken to summarize the current state of knowledge.The guideline has an explicit practical claim and will be developed and adapted by the author team based on the current increase in knowledge.
Assuntos
COVID-19 , Síndrome de COVID-19 Pós-Aguda , HumanosRESUMO
Exposome factors that lead to stressed skin can be defined as any disturbance to homeostasis from environmental (meteorological factors, solar radiation, pollution or tobacco smoke) and/or internal exposure (unhealthy diet, hormonal variations, lack of sleep, psychosocial stress). The clinical and biological impact of chronic exposome effects on skin functions has been extensively reviewed, whereas there is a paucity of information on the impact of short-term acute exposure. Acute stress, which would typically last minutes to hours (and generally no more than a week), provokes a transient but robust neuroendocrine-immune and tissue remodelling response in the skin and can alter the skin barrier. Firstly, we provide an overview of the biological effects of various acute stressors on six key skin functions, namely the skin physical barrier, pigmentation, defences (antioxidant, immune cell-mediated, microbial and microbiome maintenance), structure (extracellular matrix and appendages), neuroendocrine and thermoregulation functions. Secondly, we describe the biological and clinical effects on adult skin from individual exposome factors that elicit an acute stress response and their consequences in skin health maintenance. Clinical manifestations of acutely stressed skin may include dry skin that might accentuate fine lines, oily skin, sensitive skin, pruritus, erythema, pale skin, sweating, oedema and flares of inflammatory skin conditions such as acne, rosacea, atopic dermatitis, pigmentation disorders and skin superinfection such as viral reactivation. Acute stresses can also induce scalp sensitivity, telogen effluvium and worsen alopecia.
Assuntos
Dermatite Atópica , Expossoma , Adulto , Agressão , Exposição Ambiental , Humanos , PeleRESUMO
Stress and skin-an inseparable pair, this is how many of our patients perceive it and even clinicians are willing to integrate psychosomatic aspects into their recommendations if nothing from the somatic repertoire provides sufficient treatment. How the stress reaches the skin however is still an enigmatic matter to most lay people and professionals alike. Interestingly, psychoneuroimmunological research since the 1970s has produced a flood of valuable data. We now know that stressors, be it biochemical or psychoemotional, always elicit a neuroendocrine stress reaction with consequences for the immune response and therefore especially chronic inflammatory skin diseases. Here we employ allergic inflammation/atopic dermatitis and psoriasis as instructive model diseases to discuss basic mechanisms of molecular psychosomatic effects on chronic inflammation. The aim is to enhance pathogenetic understanding and open the door for the development and employment of integrated therapeutic concepts in dermatology.
Assuntos
Citocinas/imunologia , Neuroimunomodulação/imunologia , Dermatopatias/imunologia , Dermatopatias/psicologia , Pele/imunologia , Estresse Psicológico/imunologia , Estresse Psicológico/psicologia , Humanos , Modelos Imunológicos , Dermatopatias/diagnóstico , Estresse Psicológico/diagnósticoRESUMO
The diagnosis of skin cancer imposes a great stress on our patients. Ultraviolet (UV) radiation-induced skin cancers are on the rise and frequently occur in younger patients and unexposed sites despite improved protective behaviour. Environmental factors and lifestyle habits have changed greatly in the last century and in addition to UV radiation exposure, psychosocial stressors and physical inactivity may play a role in the rising tumour incidence. With environmental stressors such as UV radiation they share the capacity to change the stress reaction. So far research into the interaction between stress, cancer and psychosocial intervention has generated some interesting results with respect to improvement of quality of life and the function of the hypothalamic-pituitary-adrenal axis, the sympathetic axis and natural killer cells. These results hint at a suppressive effect of chronic stress on cellular immunity and the importance of a sufficient length and intensity of any psychosocial intervention for it to be effective. Nevertheless, the evidence remains inconclusive and does not take into account the findings of current psychoneuroimmunological research. This research has demonstrated the importance of a third stress axis along which neurotrophins and neuropeptides are effective. Along this axis, regulatory mechanisms may contribute to suppress tumoricidal immune responses. This may be instrumental in the establishment of an immune response that promotes tumour progression and holds important implications for integrated therapeutic strategies. However, research into the psychoneuroimmunological benefits of psychosocial intervention is largely missing, and future interdisciplinary research is warranted for understanding and further promoting improved quality of life and psychological as well as physical well-being after psychosocial intervention.
Assuntos
Neoplasias Cutâneas/psicologia , Doença Crônica , Humanos , Sistemas Neurossecretores/imunologia , Psiconeuroimunologia , Psicoterapia/métodos , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Apoio Social , Estresse Psicológico/imunologia , Estresse Psicológico/prevenção & controleRESUMO
BACKGROUND: Asthma is a chronic disease defined by airway inflammation, increased airway hyperresponsiveness and episodes of airway obstruction. Although there are abundant clinical and experimental data showing that stress may worsen asthma, the mechanisms linking stress to asthma are not well understood. By inducing a pro-inflammatory cytokine milieu, stress might enhance airway inflammation in bronchial asthma. We therefore investigated the correlation of stress perception and the cytokine profile of circulating lymphocytes in humans. METHODS: Allergic asthmatic patients and healthy controls were evaluated for perceived level of stress, demographic and lung function data. Whole blood cells were obtained and stimulated by mitogen to assess intracellular IL-4, IFN-gamma and TNF-alpha by flow cytometry. Neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were measured in serum. RESULTS: Asthmatic patients showed significantly higher percentages of TNF-alpha-producing T cells than healthy controls. Only in asthmatic patients was stress perception correlated with percentages of TNF-alpha-producing T cells and serum BDNF levels, while forced expiratory volume in 1 s (% predicted) was negatively correlated to BDNF. CONCLUSION: The results of our study support the hypothesis that stress deteriorates bronchial asthma by inducing a pro-inflammatory cytokine profile in allergic asthmatics. Stress management might provide a supplement therapy of allergic asthma.
Assuntos
Asma/imunologia , Citocinas/sangue , Fatores de Crescimento Neural/sangue , Hipersensibilidade Respiratória/imunologia , Estresse Fisiológico/complicações , Adulto , Idoso , Asma/diagnóstico , Fator Neurotrófico Derivado do Encéfalo/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fator de Crescimento Neural/sangue , Hipersensibilidade Respiratória/diagnóstico , Estresse Fisiológico/diagnóstico , Linfócitos T/imunologiaRESUMO
The skin develops probably the densest and most complex innervation of all mammalian organs, consisting of sensory and autonomic nerves loaded with a plethora of neuropeptides and neurotransmitters. Skin innervation, as well as the expression patterns of neurotrophins and their receptors, is subject to dramatic changes during not only morphogenesis but also adult tissue remodeling under physiological or inflammatory conditions. Bilateral neuroimmune interactions are the basis of adaptive responses to tissue remodeling (such as hair cycling), psycho-emotional stress or skin inflammation. Dermatitis and hair loss may be exacerbated by stress-induced neurogenic inflammation. In addition, selected inflammatory skin diseases are associated with increased innervation. Finally, inflammatory cytokines influence the cutaneous expression of neurotrophins, as well as neurotrophin-induced neurite outgrowth following axotomy. Here, we review key studies on bilateral neuroimmune interactions in the skin under both healthy and disease conditions to provide a basis for future research on the role of inflammation in peripheral nerve regeneration.
Assuntos
Inflamação , Regeneração Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Fenômenos Fisiológicos da Pele , Pele , Animais , Humanos , Pele/citologia , Pele/imunologia , Pele/inervação , Estresse Psicológico/imunologia , Estresse Psicológico/patologia , Estresse Psicológico/fisiopatologiaRESUMO
To study pathogenic stress-effects in health and disease, it is paramount to define easy access parameters for non-invasive analysis of biological change in response to stress. Hair samples successfully provide this access for the study of hypothalamus-pituitary-adrenal axis (HPA) changes. In this study, we assess the hair expression and corresponding epigenetic changes of a neurotrophin essential for autonomic nervous system function and mental health: brain derived neurotrophic factor (BDNF). In three independent studies in healthy academic volunteers (study I: German students, N=36; study II, German academic population sample, N=28; study III: Mexican students, N=115), BDNF protein expression or BDNF gene (BDNF) histone acetylation was determined. Simultaneously, mental distress and distress-associated somatic complaints were assessed by self-report. In study I, we found a negative correlation between hair-BDNF protein level and hair-cortisol as well as between hair-BDNF and somatic complaints, while hair-cortisol correlated positively with mental distress. In study II, we found a negative correlation between H4 histone acetylation at the BDNF gene P4-promoter and somatic complaints. Regression analysis confirmed confounder stability of associations in both studies. In study III, we confirmed study I and found lower hair-BDNF protein level in volunteers with high somatic complaints, who also reported higher mental distress during the end of term exams. The results indicate that BDNF protein levels can be detected in clipped hair and are associated with somatic complaints and stress in life. In addition, we concluded that plucked hair can provide material for the study of epigenetic changes in stress-affected tissues. These tools can prove valuable for future studies on distress, both under experimental and field conditions.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/análise , Estresse Fisiológico/fisiologia , Acetilação , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Epigênese Genética , Feminino , Cabelo/química , Cabelo/metabolismo , Hipocampo/metabolismo , Histonas/metabolismo , Humanos , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Dor Nociceptiva , Projetos Piloto , Sistema Hipófise-Suprarrenal/metabolismo , Regiões Promotoras Genéticas/genéticaRESUMO
As the neuropeptide substance P can manipulate murine hair growth in vivo, we here further studied the role of sensory neuropeptides in hair follicle biology by determining the distribution and hair-cycle-dependent remodeling of the sensory innervation in C57BL/6 mouse back skin. Calcitonin-gene-related peptide, substance P, and peptide histidine methionine (employed as vasoactive intestinal peptide marker) were identified by immunohistochemistry. All of these markers immunolocalized to bundles of nerve fibers and to single nerve fibers, with distinct distribution patterns and major hair-cycle-associated changes. In the epidermis and around the distal hair follicle and the arrector pili muscle, only calcitonin-gene-related peptide immunoreactive nerve fibers were visualized, whereas substance P and peptide histidine methionine immunoreactive nerve fibers were largely restricted to the dermis and subcutis. Compared to telogen skin, the number of calcitonin-gene-related peptide, substance P, and peptide histidine methionine immunoreactive single nerve fibers increased significantly (p < 0.01) during anagen, including around the bulge region (the seat of epithelial stem cells). Substance P significantly accelerated anagen progression in murine skin organ culture, whereas calcitonin-gene-related peptide and a substance-P-inhibitory peptide inhibited anagen (p < 0.05). The inhibitory effect of calcitonin-gene-related peptide could be antagonized by coadministrating substance P. In contrast to substance P, calcitonin-gene-related peptide failed to induce anagen when released from subcutaneous implants. This might reflect a differential functional assignment of the neuropeptides calcitonin-gene-related peptide and substance P in hair growth control, and invites the use of neuropeptide receptor agonists and antagonists as novel pharmacologic tools for therapeutic hair growth manipulation.
Assuntos
Folículo Piloso/crescimento & desenvolvimento , Neuropeptídeos/fisiologia , Pele/inervação , Animais , Peptídeo Relacionado com Gene de Calcitonina/imunologia , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Feminino , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/inervação , Camundongos , Camundongos Endogâmicos C57BL , Terminações Nervosas/imunologia , Técnicas de Cultura de Órgãos , Peptídeo PHI/farmacologia , Substância P/farmacologia , Peptídeo Intestinal Vasoativo/farmacologiaRESUMO
Parathyroid hormone (PTH) related peptide (PTHrP) and the PTH/PTHrP receptor (PTH/PTHrP-R) show prominent cutaneous expression, where this signaling system may exert important paracrine and/or autocrine functions, such as in hair growth control. Chemotherapy-induced alopecia - one of the fundamental unsolved problems of clinical oncology - is driven in part by defined abnormalities in hair follicle cycling. We have therefore explored the therapeutic potential of a PTH/PTHrP-R agonist and two PTH/PTHrP-R antagonists in a mouse model of cyclophosphamide-induced alopecia. Intraperitoneal administration of the agonist PTH(1-34) or the antagonists PTH(7-34) and PTHrP(7-34) significantly altered the follicular response to cyclophosphamide in vivo. PTH(7-34) and PTHrP(7-34) shifted it towards a mild form of "dystrophic anagen", associated with a significant reduction in apoptotic (TUNEL+) hair bulb cells, thus mitigating the degree of follicle damage and retarding the onset of cyclophosphamide-induced alopecia. PTH(1-34), in contrast, forced hair follicles into "dystrophic catagen", associated with enhanced intrafollicular apoptosis. We had previously shown that an induced shift in the follicular damage-response towards "dystrophic catagen" mitigates cyclophosphamide-induced alopecia, whereas a shift towards "dystrophic catagen" initially enhanced the hair loss, yet subsequently promoted accelerated hair follicle recovery. Therefore, this study in an established animal model of chemotherapy-induced alopecia, which closely mimics human chemotherapy-induced alopecia, strongly encourages the exploration of PTH/PTHrP-R agonists and antagonists as novel therapeutic agents in chemotherapy-induced alopecia.
Assuntos
Alopecia/tratamento farmacológico , Antineoplásicos Alquilantes/farmacologia , Ciclofosfamida/farmacologia , Hormônio Paratireóideo , Fragmentos de Peptídeos , Alopecia/induzido quimicamente , Animais , Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Feminino , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/patologia , Antagonistas de Hormônios/agonistas , Antagonistas de Hormônios/farmacologia , Marcação In Situ das Extremidades Cortadas , Queratinócitos/efeitos dos fármacos , Queratinócitos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Hormônio Paratireóideo/agonistas , Hormônio Paratireóideo/antagonistas & inibidores , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/agonistas , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , Proteínas/agonistas , Proteínas/antagonistas & inibidores , Proteínas/farmacologia , Teriparatida/agonistas , Teriparatida/análogos & derivados , Teriparatida/antagonistas & inibidores , Teriparatida/farmacologiaRESUMO
Recently, it has been shown that alpha-melanocyte stimulating hormone can directly activate tyrosinase by removing the allosteric regulator 6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin resulting in a stable alpha-melanocyte stimulating hormone/6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin complex. As melanin production occurs in the melanosome, a specific organelle of the melanocyte, it seemed important to investigate whether these organelles themselves actually produce pro-opiomelanocortin-related peptides in their acidic environment. The presence of alpha-melanocyte stimulating hormone and adrenocorticotropin in the epidermis and melanocytes has been shown by several investigators. In order to follow possible pro-opiomelanocortin processing in the melanosome, human melanocytes were established in MCDB 153 medium and utilized for immunohistochemistry, immunogold electron microscopy, and western blotting. For this purpose antibodies against alpha-melanocyte stimulating hormone, adrenocorticotropin, prohormone convertases 1 and 2 (PC1 and PC2) and the PC2 regulatory protein 7B2 were used. Our results demonstrated the presence of the entire system for pro-opiomelanocortin processing in the melanosome. Considering the pH optima of these convertases, the results are in agreement with an autocrine intramelanosomal production of pro- opiomelanocortin-related peptides and an autocrine production and recycling of the cofactor 6(R)-L- erythro 5,6,7,8 tetrahydrobiopterin in melanocytes. Based on these novel observations, we would like to propose that the pigmentation process may not necessarily involve a melanocortin-1 receptor-mediated mechanism.
Assuntos
Melanossomas/química , Proteínas do Tecido Nervoso/análise , Hormônios Hipofisários/análise , Pró-Opiomelanocortina/análise , Subtilisinas/análise , Western Blotting , Humanos , Melanócitos/ultraestrutura , Microscopia Imunoeletrônica , Proteína Secretora Neuroendócrina 7B2 , Pró-Proteína Convertase 2 , alfa-MSH/análiseRESUMO
Skin nerves may exert "trophic" functions during hair follicle development, growth, and/or cycling. Here, we demonstrate hair cycle-related plasticity in the sympathetic innervation of skin and hair follicle in C57BL/6 mice. Compared with telogen skin, the number of nerve fibers containing norepinephrine or immunoreactive for tyrosine hydroxylase increased during the early growth phase of the hair cycle (anagen) in dermis and subcutis. The number of these fibers declined again during late anagen. beta2-adrenoreceptor-positive keratinocytes were transiently detectable in the noncycling hair follicle epithelium, especially in the isthmus and bulge region, but only during early anagen. In early anagen skin organ culture, the beta2-adrenoreceptor agonist isoproterenol promoted hair cycle progression from anagen III to anagen IV. The observed hair cycle-dependent changes in adrenergic skin innervation on the one hand, and hair growth modulation by isoproterenol, accompanied by changes in beta2-adrenoreceptor expression of selected regions of the hair follicle epithelium on the other, further support the concept that bi-directional interactions between the hair follicle and its innervation play a part in hair growth control. This invites one to systematically explore the neuropharmacologic manipulation of follicular neuroepithelial interactions as a novel therapeutic strategy for managing hair growth disorders.
Assuntos
Adrenérgicos/farmacologia , Folículo Piloso/crescimento & desenvolvimento , Pele/inervação , Sistema Nervoso Simpático/citologia , Animais , Feminino , Folículo Piloso/efeitos dos fármacos , Isoproterenol/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Neuropeptídeo Y/análise , Norepinefrina/análise , Técnicas de Cultura de Órgãos , Receptores Adrenérgicos beta/análise , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
After the completion of skin development, angiogenesis, i.e., the growth of new capillaries from pre-existing blood vessels, is held to occur in the skin only under pathologic conditions. It has long been noted, however, that hair follicle cycling is associated with prominent changes in skin perfusion, that the epithelial hair bulbs of anagen follicles display angiogenic properties, and that the follicular dermal papilla can produce angiogenic factors. Despite these suggestive observations, no formal proof is as yet available for the concept that angiogenesis is a physiologic event that occurs all over the mature mammalian integument whenever hair follicles switch from resting (telogen) to active growth (anagen). This study uses quantitative histomorphometry and double-immunohistologic detection techniques for the demarcation of proliferating endothelial cells, to show that synchronized hair follicle cycling in adolescent C57BL/6 mice is associated with substantial angiogenesis, and that inhibiting angiogenesis in vivo by the intraperitoneal application of a fumagillin derivative retards experimentally induced anagen development in these mice. Thus, angiogenesis is a physiologic event in normal postnatal murine skin, apparently is dictated by the hair follicle, and appears to be required for normal anagen development. Anagen-associated angiogenesis offers an attractive model for identifying the physiologic controls of cutaneous angiogenesis, and an interesting system for screening the effects of potential antiangiogenic drugs in vivo.
Assuntos
Cabelo/crescimento & desenvolvimento , Neovascularização Fisiológica , Pele/irrigação sanguínea , Animais , Núcleo Celular/ultraestrutura , Cicloexanos , Endotélio Vascular/ultraestrutura , Feminino , Camundongos , Camundongos Endogâmicos C57BL , O-(Cloroacetilcarbamoil)fumagilol , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Sesquiterpenos/farmacologiaRESUMO
It has been shown in vivo that patients with the depigmentation disorder vitiligo accumulate hydrogen peroxide (H(2)O(2)) accompanied by low catalase levels and high concentrations of 6- and 7-biopterin in their epidermis. Earlier it was demonstrated that epidermal 4a-OH-tetrahydrobiopterin dehydratase, an important enzyme in the recycling process of 6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin (6BH(4)), has extremely low activities in these patients concomitant with a build-up of the abiogenic 7-isomer (7BH(4)), leading to competitive inhibition of epidermal phenylalanine hydroxylase. A topical substitution for the impaired epidermal catalase with a pseudocatalase effectively removes epidermal H(2)O(2), yielding a recovery of epidermal 4a-OH-tetrahydrobiopterin dehydratase activities and physiologic 7BH(4) levels in association with successful repigmentation demonstrating recovery of the 6BH(4) recycling process. Examination of recombinant enzyme activities, together with 4a-OH-tetrahydrobiopterin dehydratase expression in the epidermis of untreated patients, identifies H(2)O(2)-induced inactivation of this enzyme. These results are in agreement with analysis of genomic DNA from these patients yielding only wild-type sequences for 4a-OH-tetrahydrobiopterin dehydratase and therefore ruling out the previously suspected involvement of this gene. Furthermore, our data show for the first time direct H(2)O(2) inactivation of the important 6BH(4) recycling process. Based on this observation, we suggest that H(2)O(2) derived from various sources could be a general mechanism in the regulation of all 6BH(4)-dependent processes.
Assuntos
Biopterinas/análogos & derivados , Biopterinas/biossíntese , Hidroliases/metabolismo , Peróxido de Hidrogênio/metabolismo , Vitiligo/metabolismo , Catalase/farmacologia , Ativação Enzimática/efeitos dos fármacos , Epiderme/química , Epiderme/enzimologia , Humanos , Hidroliases/genética , Peróxido de Hidrogênio/farmacologia , Isomerismo , Mutação , Vitiligo/genéticaRESUMO
This study determined whether daily supplementation with 600 mg vitamin C would reduce the incidence of symptoms of upper-respiratory-tract (URT) infections after participation in a competitive ultramarathon race (> 42 km). Ultramarathon runners with age-matched controls were randomly divided into placebo and experimental (vitamin C-supplemented) groups. Symptoms of URT infections were monitored for 14 d after the race. Sixty-eight percent of the runners in the placebo group reported the development of symptoms of URT infection after the race; this was significantly more (P < 0.01) than that reported by the vitamin C-supplemented group (33%). The duration and severity of symptoms of URT infections reported in the vitamin C-supplemented nonrunning control group was also significantly less than in the nonrunning control group receiving the placebo (P < 0.05). This study provides evidence that vitamin C supplementation may enhance resistance to the postrace URT infections that occur commonly in competitive ultramarathon runners and may reduce the severity of such infections in those who are sedentary.
Assuntos
Ácido Ascórbico/uso terapêutico , Infecções Respiratórias/prevenção & controle , Corrida , Adulto , Ácido Ascórbico/administração & dosagem , Feminino , Humanos , Masculino , Infecções Respiratórias/epidemiologiaRESUMO
The influence of vitamin C supplementation on the pattern of change in plasma cytokine concentrations was measured in 29 runners following a 90-km ultramarathon. The study was based on a 3 (groups) by 4 (blood samples at 16 prerace, postrace, and 24 h and 48 h postrace) repeated measures design. Groups included placebo control (n = 7) and two groups supplementing vitamin C at 500 mg/day (vit C-500, n = 10) or 1500 mg/day (vit C-1500, n = 12) for 7 days before the race, on race day, and for 2 days after the race. All measured plasma cytokine concentrations were significantly elevated immediately postrace, with the magnitude of increase for tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) much smaller than for IL-6, IL-10, IL-8, and IL-1 receptor antagonist (IL-1RA). Cortisol increased in all groups immediately after the race but significantly less in the vit C-1500 group. Group x time interaction statistics were not significant for any of the plasma cytokines. However, when the placebo and vit C-500 groups were combined (n = 17) and compared with the vit C-1500 group (n = 12), immediate postrace plasma concentrations were significantly lower in the vit C-1500 group for IL-1RA (-57%) and IL-10 (-57%), with a trend measured for IL-6 (-27%, p = 0.11) and IL-8 (-26%, p = 0.14). In summary, runners completing the 90-km Comrades Ultramarathon experienced strong increases in concentrations of plasma IL-6, IL-10, IL-1RA, and IL-8. These increases were attenuated in runners ingesting 1500 mg but not 500 mg vitamin C supplements for 1 week prior to the race and on race day.
Assuntos
Ácido Ascórbico/farmacologia , Citocinas/sangue , Suplementos Nutricionais , Corrida , Adulto , Ácido Ascórbico/administração & dosagem , Humanos , Hidrocortisona/sangue , Pessoa de Meia-IdadeRESUMO
Four hundred thirteen recent clinical isolates of Staphylococcus, Haemophilus, Moraxella, and Neisseria species were tested for beta-lactamase production using the Difco DrySlide beta-lactamase test. These results were compared with those of the BBL Cefinase reagent. Of the 413 isolates tested, 258 (62.5%) were beta-lactamase positive. There was 99.8% agreement between the two test methods; only one isolate of Staphylococcus aureus was DrySlide-negative and Cefinase-positive. The DrySlide beta-lactamase reagent is an accurate and convenient format for the evaluation of beta-lactamase activity in the clinical laboratory.
Assuntos
beta-Lactamases/análise , Estudos de Avaliação como Assunto , Humanos , Sensibilidade e EspecificidadeRESUMO
Renal medullary cells contain large quantities of organic osmolytes when the levels of salt and urea in renal medullary interstitial fluid are high. Two of these osmolytes, betaine and glycerophosphocholine (GPC), are methylamines. Methylamines generally counteract the perturbing effects of urea on enzymes and other macromolecules. Betaine was previously shown to counteract the effect of urea on enzymes in vitro and to protect renal cells in tissue culture from harmful effects of high urea. Nevertheless, renal medullary cells in vivo and in tissue culture specifically accumulate GPC rather than betaine, in response to high urea. In the present studies we tested directly whether GPC counteracts the effect of urea on the Km of pyruvate kinase (PK) for ADP and compared the effectiveness in this regard of GPC to that of betaine. We find that urea increases the Km (as previously observed), that betaine and GPC decrease it, and that the increase caused by urea is counteracted by betaine or by GPC. The effects of GPC are slightly less than those of betaine. In addition, other renal medullary organic osmolytes (namely sorbitol, inositol and taurine) were already known to be compatible osmolytes whose accumulation protects renal medullary cells from hypertonicity because they have little effect on enzyme function. In agreement with this generalization we find that high sorbitol or inositol has little or no effect on PK activity, but surprisingly that taurine reduces Vmax and greatly elevates Km. In conclusion, the main finding is direct evidence that GPC is a counteracting osmolyte, which explains its accumulation in response to high urea. However, we do not find that GPC is a more effective counteracting osmolyte than betaine, which leaves unexplained the preference of renal cells for GPC over betaine for counteracting the perturbing effect of urea.
Assuntos
Betaína/farmacologia , Glicerilfosforilcolina/farmacologia , Medula Renal/efeitos dos fármacos , Piruvato Quinase/metabolismo , Ureia/antagonistas & inibidores , Animais , Betaína/metabolismo , Glicerilfosforilcolina/metabolismo , Inositol/metabolismo , Inositol/farmacologia , Medula Renal/metabolismo , Sorbitol/metabolismo , Sorbitol/farmacologia , Taurina/metabolismo , Taurina/farmacologia , Ureia/metabolismo , Ureia/farmacologiaRESUMO
The absolute configuration of (+)-isoshinanolone, a wide-spread acetogenic metabolite from higher plants, has been determined by X-ray structure analysis of its new dibromide; accordingly, this natural tetralone is 3R,4R-configured, in agreement with previous degradative results. In addition, a first chiroptical on-line stereoanalysis for isoshinanolones is presented, i.a. by HPLC on a chiral phase coupled to CD spectroscopy, giving pure CD spectra of all of the four stereoisomers of isoshinanolone directly from stereoisomeric mixtures.
Assuntos
Plantas/química , Tetra-Hidronaftalenos/química , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Conformação Molecular , Extratos Vegetais/química , EstereoisomerismoRESUMO
The isolation of 6-hydroxyluteolin-7-O-(1"-alpha-rhamnoside) from the Central American epiphyte Vriesea sanguinolenta Cogn. and Marchal (Bromeliaceae) is described here. Its stereostructure was established by spectroscopic methods and an X-ray structure analysis of its hepta-O-acetyl derivative. This flavonoid glycoside had previously been reported from some Teucrium species (Labiatae), yet without sufficient physical data and spectroscopic evidence.
Assuntos
Glicosídeos/isolamento & purificação , Luteolina , Plantas/química , Animais , Antimaláricos/química , Antimaláricos/isolamento & purificação , Cristalografia por Raios X , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Folhas de Planta/química , Plantas/classificação , Plasmodium falciparum/efeitos dos fármacosRESUMO
Neuropeptides produced, stored and secreted by the unusually dense sensory and autonomic innervation of hair follicles (HFs) can induce hair growth (anagen) and may be involved in hair growth control. To test the role of follicle innervation of HF cycling in vivo, we generated innervation-deficient HFs by unilateral surgical denervation of a defined region of back skin in C57BL/6 mice and assessed its effect on spontaneous and induced anagen development. Successful denervation was demonstrated by the absence of PGP 9.5+ or tyrosine hydroxylase+ nerves and nerve-associated neuropeptides (substance P, CGRP). By quantitative histomorphometry, no significant difference in spontaneous or cyclosporin A-induced anagen development could be detected between sham-operated control skin and denervated skin. Only after hair growth induction by depilation, a discrete, marginally significant retardation of anagen development was apparent in denervated HFs. Thus, even though cutaneous nerves may exert a minor modulatory role in depilation-induced hair growth, they are not essential for normal murine anagen development.