Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 118
Filtrar
1.
Water Res ; 247: 120746, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37984031

RESUMO

The discharge of pathogens into urban recreational water bodies during combined sewer overflows (CSOs) pose a potential threat for public health which may increase in the future due to climate change. Improved methods are needed for predicting the impact of these effects on the microbiological urban river water quality and infection risks during recreational use. The aim of this study was to develop a novel probabilistic-deterministic modelling approach for this purpose building on physically plausible generated future rainfall time series. The approach consists of disaggregation and validation of daily precipitation time series from 21 regional climate models for a reference period (1971-2000, C20), a near-term future period (2021-2050, NTF) and a long-term future period (2071-2100, LTF) into sub-daily scale, and predicting the concentrations of enterococci and Giardia and Cryptosporidium, and infection risks during recreational use in the river downstream of the sewage emissions from CSOs. The approach was tested for an urban river catchment in Austria which is used for recreational activities (i.e. swimming, playing, wading, hand-to-mouth contact). According to a worst-case scenario (i.e. children bathing in the river), the 95th percentile infection risks for Giardia and Cryptosporidium range from 0.08 % in winter to 8 % per person and exposure event in summer for C20. The infection risk increase in the future is up to 0.8 log10 for individual scenarios. The results imply that measures to prevent CSOs may be needed to ensure sustainable water safety. The approach is promising for predicting the effect of climate change on urban water safety requirements and for supporting the selection of sustainable mitigation measures. Future studies should focus on reducing the uncertainty of the predictions at local scale.


Assuntos
Criptosporidiose , Cryptosporidium , Giardíase , Criança , Humanos , Esgotos , Mudança Climática , Qualidade da Água , Giardia , Monitoramento Ambiental/métodos
2.
Med Klin Intensivmed Notfmed ; 114(8): 724-732, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30132026

RESUMO

BACKGROUND: Quick sequential organ failure assessement (qSOFA) has been validated for patients with presumed sepsis and the general emergency department (ED) population. However, it has not been validated in specific subgroups of ED patients with a high mortality. We aimed to investigate the prognostic performance of qSOFA with respect to in-hospital mortality, intensive care unit (ICU) admission, and length of hospitalisation in patients with decompensated liver cirrhosis. Furthermore, we compared qSOFA to systemic inflammatory response syndrome (SIRS), model of end stage liver disease score (MELD), and Child-Pugh criteria and evaluated whether addition of sodium (Na+) levels to qSOFA increases its prognostic performance. METHODS: This observational study included patients admitted with the diagnosis of decompensated liver cirrhosis. All patients with a complete set of vital parameters were included in this study. RESULTS: A total of 186 patients were included. A positive qSOFA score was not associated with in-hospital mortality, ICU admission, or length of hospitalisation (all p > 0.15). MELD scores reliably predicted need for ICU admission and in-hospital mortality (both p < 0.01), but not the length of hospitalisation. qSOFA-Na+ only moderately increased the diagnostic performance of qSOFA with regard to need for ICU admission (AUCICU[qSOFA] = 0.504 vs. AUCICU[qSOFA-Na+] = 0.609, p = 0.03), but not for in-hospital mortality (AUCdeath[qSOFA] = 0.513 vs. AUCdeath[qSOFA-Na+] = 0.592, p = 0.054). CONCLUSION: qSOFA does not predict in-hospital mortality, ICU admission or length of hospitalisation in patients with decompensated liver cirrhosis. Extension of qSOFA with a disease-specific component, the qSOFA-Na+, moderately increased the diagnostic ability of qSOFA.


Assuntos
Mortalidade Hospitalar , Cirrose Hepática , Escores de Disfunção Orgânica , Sepse , Humanos , Cirrose Hepática/mortalidade , Prognóstico , Estudos Retrospectivos , Síndrome de Resposta Inflamatória Sistêmica
3.
Br J Anaesth ; 120(2): 274-283, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29406176

RESUMO

BACKGROUND: This double-blind randomised controlled trial investigated whether normal saline or a balanced crystalloid has distinct effects on vasopressor use in patients undergoing major abdominal surgery. METHODS: Patients received either normal saline 0.9% or an acetate-buffered crystalloid for intraoperative volume replacement in a goal-directed fashion. The primary outcome was need for vasopressors; the secondary outcomes were the total dose of catecholamines, total perioperative fluid, and unplanned intensive care admissions. RESULTS: This study was terminated early for safety reasons. A total of 60 out of the planned 240 patients were randomized. Thirty patients received normal saline and 30 patients received the balanced crystalloid, with a total volume of 3427 (2732-4130) ml and 3144 (1673-4926), respectively. The normal-saline group developed hyperchloraemic metabolic acidosis. More patients needed vasopressors for circulatory support in the normal-saline group compared with the buffered crystalloid group (97% vs 67%, respectively; P=0.033). The median weight and anaesthesia duration-adjusted dose of norepinephrine were 0.11 (0.00-0.45) ng kg-1 min-1 and 0.00 (0.00-0.00) kg-1 min-1 in the normal-saline and balanced-crystalloid groups, respectively (P=0.003). Cox regression revealed that the need for vasopressors was related to a high volume of administered fluid, normal-saline resuscitation, and lower mean arterial blood pressure. There was no difference between the groups in total perioperative fluid and unplanned intensive-care-unit admissions. Between-group differences in the duration of anaesthesia did not influence the necessity for a vasopressor. CONCLUSIONS: Compared with patients receiving a balanced crystalloid, normal saline in patients undergoing major abdominal surgery was associated with an increased need for vasopressor support. This should be interpreted in view of the large volume of fluid resuscitation and the small sample size because of the preliminary termination of the study. CLINICAL TRIAL REGISTRATION: EudraCT 2014-004867-19, NCT 02414555.


Assuntos
Abdome/cirurgia , Soluções Cristaloides/uso terapêutico , Hidratação/métodos , Assistência Perioperatória/métodos , Solução Salina/uso terapêutico , Procedimentos Cirúrgicos Operatórios/métodos , Acidose/induzido quimicamente , Acidose/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Objetivos , Hemodinâmica , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Vasoconstritores/uso terapêutico
4.
Water Res ; 90: 265-276, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26745175

RESUMO

This was a detailed investigation of the seasonal occurrence, dynamics, removal and resistance of human-associated genetic Bacteroidetes faecal markers (GeBaM) compared with ISO-based standard faecal indicator bacteria (SFIB), human-specific viral faecal markers and one human-associated Bacteroidetes phage in raw and treated wastewater of municipal and domestic origin. Characteristics of the selected activated sludge wastewater treatment plants (WWTPs) from Austria and Germany were studied in detail (WWTPs, n = 13, connected populations from 3 to 49000 individuals), supported by volume-proportional automated 24-h sampling and chemical water quality analysis. GeBaM were consistently detected in high concentrations in raw (median log10 8.6 marker equivalents (ME) 100 ml(-1)) and biologically treated wastewater samples (median log10 6.2-6.5 ME 100 ml(-1)), irrespective of plant size, type and time of the season (n = 53-65). GeBaM, Escherichia coli, and enterococci concentrations revealed the same range of statistical variability for raw (multiplicative standard deviations s* = 2.3-3.0) and treated wastewater (s* = 3.7-4.5), with increased variability after treatment. Clostridium perfringens spores revealed the lowest variability for raw wastewater (s* = 1.5). In raw wastewater correlations among microbiological parameters were only detectable between GeBaM, C. perfringens and JC polyomaviruses. Statistical associations amongst microbial parameters increased during wastewater treatment. Two plants with advanced treatment were also investigated, revealing a minimum log10 5.0 (10th percentile) reduction of GeBaM in the activated sludge membrane bioreactor, but no reduction of the genetic markers during UV irradiation (254 nm). This study highlights the potential of human-associated GeBaM to complement wastewater impact monitoring based on the determination of SFIB. In addition, human-specific JC polyomaviruses and adenoviruses seem to be a valuable support if highly specific markers are needed.


Assuntos
Bacteroidetes/isolamento & purificação , Fezes/microbiologia , Águas Residuárias/microbiologia , Microbiologia da Água , Adenoviridae/isolamento & purificação , Áustria , Reatores Biológicos , Clostridium perfringens/isolamento & purificação , Enterococcus/isolamento & purificação , Monitoramento Ambiental , Escherichia coli/isolamento & purificação , Alemanha , Humanos , Vírus JC/isolamento & purificação , Modelos Estatísticos , Esgotos/microbiologia , Raios Ultravioleta , Eliminação de Resíduos Líquidos , Poluentes da Água , Purificação da Água
5.
Int J Clin Pract ; 68(11): 1352-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24898571

RESUMO

BACKGROUND: To date, the use of proton pump inhibitors (PPIs) has been associated with a low risk of hypomagnesaemia and associated adverse outcomes. We hypothesised that a better risk estimate could be derived from a large cohort of outpatients admitted to a tertiary emergency department (ED). METHODS: A cross-sectional study was performed in 5118 patients who had measurements of serum magnesium taken on admission to a large tertiary care ED between January 2009 and December 2010. Hypomagnesaemia was defined as a serum magnesium concentration < 0.75 mmol/l. Demographical data, serum electrolyte values, data on medication, comorbidities and outcome with regard to length of hospital stay and mortality were analysed. RESULTS: Serum magnesium was normally distributed where upon 1246 patients (24%) were hypomagnesaemic. These patients had a higher prevalence of out-of-hospital PPI use and diuretic use when compared with patients with magnesium levels > 0.75 mmol/l (both p < 0.0001). In multivariable regression analyses adjusted for PPIs, diuretics, renal function and the Charlson comorbidity index score, the association between use of PPIs and risk for hypomagnesaemia remained significant (OR = 2.1; 95% CI: 1.54-2.85). While mortality was not directly related to low magnesium levels (p = 0.67), the length of hospitalisation was prolonged in these patients even after adjustment for underlying comorbid conditions (p < 0.0001). CONCLUSION: Use of PPIs predisposes patients to hypomagnesaemia and such to prolonged hospitalisation irrespective of the underlying morbidity, posing a critical concern.


Assuntos
Serviço Hospitalar de Emergência , Homeostase/efeitos dos fármacos , Magnésio/sangue , Inibidores da Bomba de Prótons/uso terapêutico , Adulto , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Inibidores da Bomba de Prótons/efeitos adversos
6.
Minerva Med ; 105(4): 275-81, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24867188

RESUMO

Falls in the elderly are a major source of injury resulting in disability and hospitalization. They have a significant impact on individual basis (loss of quality of live, nursing home admissions) and social basis (healthcare costs). Even though falls in the elderly are common there are some well studied risk factors. Special emphasis should be put on sarcopenia/frailty, polypharmacy, multimorbidity, vitamin D status and home hazards. There are several well evaluated fall prevention approaches that either target a single fall risk factor or focus on multiple risk factors. It has to be kept in mind that not all fall prevention strategies are useful for all patients as for example dietary substitution of vitamin D is only recommended in people with increased risk for a vitamin D deficiency. Home hazard reduction strategies are more effective when combined with other fall prevention approaches such as for example exercise programs. In conclusion elderly patients should routinely be screened for relevant risk factors and if need an indiviudally targeted fall prevention program compiled.


Assuntos
Acidentes por Quedas/prevenção & controle , Acidentes Domésticos/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Exercício Físico , Feminino , Idoso Fragilizado , Humanos , Masculino , Força Muscular , Polineuropatias/complicações , Polimedicação , Medição de Risco/métodos , Fatores de Risco , Sarcopenia/complicações , Transtornos da Visão/complicações , Vitamina D/administração & dosagem , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/prevenção & controle , Vitaminas/administração & dosagem
8.
Anaesthesist ; 62(4): 296-303, 2013 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-23558720

RESUMO

Electrolyte disorders are common and potentially fatal laboratory findings in emergency patients. Approximately 20 % of patients in the emergency department present with either hyponatremia or hypernatremia. Recently it was shown that disorders of serum sodium are not only an expression of the severity of the underlying disease but independent predictors for the outcome of patients. They directly influence patient daily life by causing not only gait and concentration disturbances but also an increased tendency to fall together with a reduced bone mass. Given these new data it is even more important to detect and adequately correct dysnatremia in patients in the emergency department. Acute, symptomatic dysnatremia should be corrected promptly by use of 3 % NaCl for hyponatremia and 5 % glucose for hypernatremia. A close monitoring of serum sodium concentration is, however, essential in any case of correction of hyponatremia or hypernatremia in order to avoid rapid overcorrection and subsequent complications. A profound knowledge of the mechanisms underlying the development of hyponatremia, e.g. diuretics, syndrome of inappropriate antidiuretic hormone secretion (SIADH), heart failure and cirrhosis of the liver and hypernatremia, e.g. dehydration, infusions, diuretics and osmotic diuresis is essential. The present article describes the epidemiology, etiology and correction of hyponatremia and hypernatremia on the basis of current knowledge with special emphasis on emergency department patients.


Assuntos
Sódio/sangue , Desequilíbrio Hidroeletrolítico/sangue , Desequilíbrio Hidroeletrolítico/terapia , Algoritmos , Serviços Médicos de Emergência , Humanos , Hipernatremia/sangue , Hipernatremia/terapia , Hiponatremia/sangue , Hiponatremia/terapia , Síndrome de Secreção Inadequada de HAD/diagnóstico , Concentração Osmolar , Prevalência , Desequilíbrio Hidroeletrolítico/complicações , Desequilíbrio Hidroeletrolítico/epidemiologia
9.
Minerva Med ; 103(4): 279-91, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22805620

RESUMO

Hyponatremia is the most common electrolyte disorder in hospitalized patients. According to the Edelman equation, hyponatremia usually develops due to a gain of free water, a loss of serum sodium or a combination of both. Investigating the causes of hyponatremia and consequent correction of the electrolyte disorder can be challenging. In this review we give an overview on the mechanisms leading to hyponatremia and in a further step, the correction of hyponatremia is discussed in detail with sections on: rate of correction, treatment with respect to volume state, risks of correction and a discussion of vasopressin receptor antagonists.


Assuntos
Antagonistas dos Receptores de Hormônios Antidiuréticos , Hiponatremia/etiologia , Hiponatremia/terapia , Água Corporal/metabolismo , Gerenciamento Clínico , Humanos , Rim/metabolismo , Sódio/metabolismo , Vasopressinas/metabolismo
11.
Eur J Clin Invest ; 37(10): 820-5, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17764464

RESUMO

BACKGROUND: The increasingly recognized prognostic impact of the strong ion gap in critical illness is in contrast to its largely unknown chemical nature. Experimental and clinical evidence suggest that acute phase proteins might account for elevation of the strong ion gap. The hypothesis of this investigation was that acute phase proteins account for strong ion gap in critically ill patients. MATERIALS AND METHODS: The charges of the two acute phase proteins C-reactive protein and fibrinogen were estimated by a computer model. Additionally, 142 patients admitted to a medical intensive care unit of a university hospital were studied prospectively during a six month period. Serial daily observations were recorded and classified according to the systemic inflammatory state. The acute phase proteins C-reactive protein and fibrinogen were measured and the strong ion gap was calculated from the measured acid-base variables. RESULTS: The approximated mean charges of C-reactive protein and fibrinogen at a pH of 7.4 are -4.0 and -13.6 per molecule, respectively. Therefore, their negative charge is too small to explain the elevated strong ion gap even during a substantial increase of C-reactive protein and fibrinogen due to an acute-phase reaction. Moreover, C-reactive protein did not correlate with the strong ion gap when partialized for creatinine (R = 0.02, P = 0.567). Fibrinogen did not correlate with the strong ion gap. Creatinine correlated with the strong ion gap (R = 0.42, P < 0.001). Neither systemic inflammatory state nor increasing C-reactive protein levels were associated with an increasing strong ion gap. CONCLUSION: Acute phase proteins do not account for an elevated strong ion gap in critically ill patients.


Assuntos
Equilíbrio Ácido-Base , Ânions/análise , Gasometria/métodos , Proteína C-Reativa/análise , Fibrinogênio/análise , Concentração de Íons de Hidrogênio , Desequilíbrio Ácido-Base/sangue , Adulto , Idoso , Ânions/sangue , Dióxido de Carbono/sangue , Simulação por Computador , Estado Terminal , Interpretação Estatística de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos
12.
Artigo em Inglês | MEDLINE | ID: mdl-15458492

RESUMO

One hundred and ten clinical Escherichia coli isolates of serovar O157 (n = 102) and O26 (n = 8) were characterized for the presence of putative virulence genes by PCR. All but one of these isolates contained the eae gene. The EHEC-hly gene could be detected in all E. coli O157 and in 50% of E. coli O26 isolates. Forty-five (40.9%) of the 110 E. coli were positive for both stx(1) and stx(2) genes, 2 (1.8%) isolates were positive for stx(1) and 57 isolates (51.8%) were positive for stx(2) only. Among the 102 stx(2) positive isolates, 14 (13.7%) E. coli O157 contained also the stx(2c) variant gene. No other stx(2) variant was identified. Six clinical isolates (five E. coli O157:H7 and one E. coli O26) did not contain stx genes. Ten non-pathogenic E. coli isolates which were amplified as controls didn't contain any stx and eae gene but two of the ten strains contained the EHEC-hly gene. By their growth on chromogenic media, all but two of 50 E. coli O157 could be differentiated from eight E. coli O26 and 10 non-pathogenic E. coli. Sixty-one of the O157:H7 isolates were further subjected to pulsed-field gel electrophoresis (PFGE) which identified 49 distinguishable patterns. In five cases where contact infection among family members was suspected, indistinguishable PFGE patterns confirmed the epidemiological relatedness of the isolates. Moreover, two PFGE clusters were identified which comprised five and three strains, respectively. These findings indicate the occurrence of both family and diffuse outbreaks of E. coli O157 infections in Austria during recent years and demonstrate the need for molecular subtyping of these pathogens.


Assuntos
Infecções por Escherichia coli/microbiologia , Escherichia coli O157/patogenicidade , Adesinas Bacterianas/análise , Adolescente , Adulto , Idoso , Áustria/epidemiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , DNA Bacteriano/análise , Eletroforese em Gel de Campo Pulsado , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/prevenção & controle , Escherichia coli O157/genética , Escherichia coli O157/metabolismo , Proteínas de Escherichia coli/análise , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase , Sorotipagem , Toxinas Shiga/metabolismo
13.
J Invest Dermatol ; 116(6): 947-55, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11407986

RESUMO

In this study, we have correlated cutaneous apoptosis and proliferation in neonatal mice during hair follicle morphogenesis. We have applied a novel triple- staining technique that uses Ki67 immunoreactivity as a marker of proliferation as well as TUNEL and Hoechst 33342 staining as apoptosis markers. We have also assessed the immunoreactivity of interleukin-1 beta-converting enzyme, caspase 1, a key enzyme in the execution of apoptosis, and of P-cadherin, which has been suggested as a key adhesion receptor in segregating proliferating keratinocytes. The TUNEL data were systematically compared with high resolution light microscopy and transmission electron microscopy data. Virtually all keratinocytes of the developing hair bud were strongly Ki67(+), suggesting that the hair bud is not an epidermal invagination but primarily the product of localized keratinocyte proliferation. As hair follicle development advanced, three distinct foci of proliferation became apparent: the distal outer root sheath around the hair canal, the mid outer root sheath, and the proximal hair matrix. Of these proliferating hair follicle keratinocytes only defined subsets expressed P-cadherin. TUNEL(+) cells in the hair follicle were not found before stage 5 of murine hair follicle morphogenesis. During the early stages of hair follicle development, interleukin-1 beta-converting enzyme immunoreactivity was present on all keratinocytes, but virtually disappeared from the proximal hair follicle epithelium later on. High resolution light microscopy/transmission electron microscopy revealed scattered and clustered apoptotic keratinocytes in all epithelial hair follicle compartments throughout hair follicle development, including its earliest stages. This highlights striking differences in the demarcation of apoptotic hair follicle keratinocytes between the TUNEL technique and high resolution light microscopy/transmission electron microscopy and suggests a role for apoptosis in sculpting the hair follicle even during early hair follicle development.


Assuntos
Apoptose , Folículo Piloso/crescimento & desenvolvimento , Animais , Caderinas/análise , Caspase 1/análise , Divisão Celular , Feminino , Folículo Piloso/química , Folículo Piloso/ultraestrutura , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica , Morfogênese
14.
Br J Dermatol ; 143(5): 1036-9, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11069516

RESUMO

BACKGROUND: Hair loss following skin inflammation may in part be mediated by keratinocyte (KC) apoptosis. While the effects of different cytokines or other apoptosis stimulating agents such as interferon (IFN)-gamma or tumour necrosis factor (TNF)-alpha on KC apoptosis in vitro have been addressed in several studies, little is known about the effects of proinflammatory cytokines on KC apoptosis in vivo. OBJECTIVES: To study the effects of intradermally injected TNF-alpha, interleukin (IL)-1beta and IFN-gamma on KC apoptosis in the back skin of C57BL/6 mice. METHODS: Apoptosis in epidermal and hair bulb KCs was analysed by immunohistology using TUNEL staining. RESULTS: Injection of TNF-alpha induced a significantly higher number of apoptotic cells within the epidermis than vehicle; all three proinflammatory cytokines together further increased their number. Intrafollicular hair bulb KCs were much more susceptible to apoptosis induction by TNF-alpha or IL-1beta; their injection significantly upregulated apoptosis after 6 h, which was further increased after 24 h. The combination of all cytokines together accelerated intrafollicular apoptosis after 6 h by doubling the number of apoptotic cells per hair bulb, compared with the effects of TNF-alpha or IL-1beta alone. CONCLUSIONS: These data suggest that programmed cell death of proliferating KCs in vivo can be induced by proinflammatory cytokines.


Assuntos
Apoptose/efeitos dos fármacos , Citocinas/farmacologia , Folículo Piloso/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Animais , Folículo Piloso/citologia , Interferon gama/farmacologia , Interleucina-1/farmacologia , Queratinócitos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa/farmacologia
16.
FASEB J ; 14(5): 752-60, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10744631

RESUMO

The regression phase of the hair cycle (catagen) is an apoptosis-driven process accompanied by terminal differentiation, proteolysis, and matrix remodeling. As an inhibitor of keratinocyte proliferation and inductor of keratinocyte apoptosis, transforming growth factor beta1 (TGF-beta1) has been proposed to play an important role in catagen regulation. This is suggested, for example, by maximal expression of TGF-beta1 and its receptors during late anagen and the onset of catagen of the hair cycle. We examined the potential involvement of TGF-beta1 in catagen control. We compared the first spontaneous entry of hair follicles into catagen between TGF-beta1 null mice and age-matched wild-type littermates, and assessed the effects of TGF-beta1 injection on murine anagen hair follicles in vivo. At day 18 p.p., hair follicles in TGF-beta1 -/- mice were still in early catagen, whereas hair follicles of +/+ littermates had already entered the subsequent resting phase (telogen). TGF-beta1-/- mice displayed more Ki-67-positive cells and fewer apoptotic cells than comparable catagen follicles from +/+ mice. In contrast, injection of TGF-beta1 into the back skin of mice induced premature catagen development. In addition, the number of proliferating follicle keratinocytes was reduced and the number of TUNEL + cells was increased in the TGF-beta1-treated mice compared to controls. Double visualization of TGF-beta type II receptor (TGFRII) and TUNEL reactivity revealed colocalization of apoptotic nuclei and TGFRII in catagen follicles. These data strongly support that TGF-beta1 ranks among the elusive endogenous regulators of catagen induction in vivo, possibly via the inhibition of keratinocyte proliferation and induction of apoptosis. Thus, TGF-betaRII agonists and antagonists may provide useful therapeutic tools for human hair growth disorders based on premature or retarded catagen development (effluvium, alopecia, hirsutism).


Assuntos
Folículo Piloso/crescimento & desenvolvimento , Fator de Crescimento Transformador beta/fisiologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/fisiologia , Humanos , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/farmacologia
17.
FASEB J ; 14(2): 319-32, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10657988

RESUMO

HGF/SF and its receptor (Met) are principal mediators of mesenchymal-epithelial interactions in several different systems and have recently been implicated in the control of hair follicle (HF) growth. We have studied their expression patterns during HF morphogenesis and cycling in C57BL/6 mice, whereas functional hair growth effects of HGF/SF were assessed in vivo by analysis of transgenic mice and in skin organ culture. In normal mouse skin, follicular expression of HGF/SF and Met was strikingly localized: HGF/SF was found only in the HF mesenchyme (dermal papilla fibroblasts) and Met in the neighboring hair bulb keratinocytes. Both HGF/SF and Met expression peaked during the initial phases of HF morphogenesis, the stage of active hair growth (early and mid anagen), and during the apoptosis-driven HF regression (catagen). Met+ cells in the regressing epithelial strand appeared to be protected from undergoing apoptosis. Compared to wild-type controls, transgenic mice overexpressing HGF/SF under the control of the MT-1 promoter had twice as many developing HF and displayed accelerated HF development on postnatal day 3. They also showed significant catagen retardation on P17. In organ culture and in vivo, HGF/SF i.c. resulted in a significant catagen retardation. These results demonstrate an important role of HGF/SF and Met in murine hair growth control and suggest that Met-mediated signaling might be exploited for therapeutic manipulation of human hair growth disorders.-Lindner, G., Menrad, A., Gherardi, E., Merlino, G., Welker, P., Handjiski, B., Roloff, B., Paus, R. Involvement of hepatocyte growth factor/scatter factor and Met receptor signaling in hair follicle morphogenesis and cycling.


Assuntos
Folículo Piloso/crescimento & desenvolvimento , Fator de Crescimento de Hepatócito/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Feminino , Fator de Crescimento de Hepatócito/genética , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Morfogênese , Técnicas de Cultura de Órgãos , Proteínas Proto-Oncogênicas c-met/genética , RNA Mensageiro/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais
20.
Inorg Chem ; 39(13): 2740-6, 2000 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-11232808

RESUMO

The unique optical properties of Se2- radicals located in the cages of the sodalite structure are reported. By means of luminescence, photoluminescence excitation, and absorption spectroscopy, three different centers are identified. Two of them are Se2- anions in sites with presumably a tetrahedral Na4(4+) coordination and a Na3(3+) environment with cation deficiency, respectively, giving rise to a red luminescence band with two different progressions. The third center is the intermediate Se2 molecule, created photochemically by UV laser excitation. It induces an additional blue luminescence. The electronic properties of the Se2- centers, particularly in the excited states, are significantly influenced by steric constraints imposed by the limited space in the sodalite host polyhedra. Thus, the sodalite structure can be viewed as a model system for studying effects of this kind on chromophores imbedded in the cages of the zeolite-type lattice.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...