RESUMO
OBJECTIVE: Defensins are immunomodulatory peptides and components of the innate immune response. They have been shown to be modulated in various disease states and in response to inflammatory stimuli. Recently, alpha-defensins have been implicated in the pathogenesis of autoimmune diseases. In order to explore whether these defensins may have a role in the pathogenesis of systemic lupus erythematosus (SLE), we sought to determine whether altered expression can be found in SLE patients. MATERIAL AND METHODS: Serum and EDTA-blood of 50 SLE patients who fulfilled the American College of Rheumatology (ACR) criteria (aged 41.4 ± 13.3 years) and 28 age- and sex-matched healthy controls were collected. Real-time polymerase chain reaction with gene-specific primers for human neutrophil peptides (HNPs), human beta-defensin 2 and 3 (hBD2, 3) in isolated polymorphonuclear cells and enzyme-linked immunosorbent assay (ELISA) in serum samples were performed. Results of SLE patients were compared with the control group and correlated to routine laboratory parameters, clinical data and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). RESULTS: SLE patients were predominantly female (90%) with a mean SLEDAI of 5.7 ± 6.1. In sera, patients displayed higher amounts of hBD2 and HNPs when compared with healthy controls. Furthermore, hBD2 correlated with levels of anti-dsDNA antibodies, erythrocyte count and the SLEDAI. Elevated values were observed in patients with myositis (n = 4). Serum HNPs on the other hand correlated with the neutrophil count and was elevated in patients with a rash (n = 7). Lupus patients suffering from transverse myelitis (n = 3) had raised serum-values of both HNPs and hBD2. While no mRNA of hBD2 or hBD3 was detected in polymorphonuclear cells, HNP mRNA was found in both healthy controls and patients without significant difference. Lupus nephritis and rash were associated with higher amounts of HNP mRNA, and the relative amount of copies correlated positively with the SLEDAI and negatively with C3 measurements. CONCLUSIONS: Serum levels of hBD2 and HNPs are elevated in SLE. The correlations of hBD2 and HNPs to established disease activity parameters and distinct clinical situations suggest that innate immune mechanisms are activated. Defensins may be involved in SLE pathogenesis.
Assuntos
Regulação da Expressão Gênica , Lúpus Eritematoso Sistêmico/imunologia , alfa-Defensinas/sangue , beta-Defensinas/sangue , Adulto , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lúpus Eritematoso Sistêmico/fisiopatologia , Nefrite Lúpica/imunologia , Masculino , Pessoa de Meia-Idade , Miosite/etiologia , Miosite/imunologia , Neutrófilos/metabolismo , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Índice de Gravidade de Doença , alfa-Defensinas/genética , beta-Defensinas/genéticaRESUMO
BACKGROUND: In a multidisciplinary conference patients with advanced non-resectable hepatocellular carcinoma (HCC) were stratified according to their clinical status and tumor extent to different regional modalities or to best supportive care. The present study evaluated all patients who were stratified to repeated transarterial chemoembolization (TACE) from 1999 until 2003 in terms of tumor response, toxicity, and survival. A moderate embolizing approach was chosen using a combination of degradable starch microspheres (DSM) and iodized oil (Lipiodol) in order to combine anti-tumoral efficiency and low toxicity. METHODS: Fourty-seven patients were followed up prospectively. TACE treatment consisted of cisplatin (50 mg/m(2)), doxorubicin (50 mg/m(2)), 450-900 mg DSM, and 5-30 ml Lipiodol. DSM and Lipiodol were administered according to tumor vascularization. Patient characteristics, toxicity, and complications were outlined. In multivariate regression analyses of pre-treatment variables from a prospective database, predictors for tumor response and survival after TACE were determined. RESULTS: 112 TACE courses were performed (2.4+/-1.5 courses per patient). Mean maximum tumor size was 75 (+/-43) mm, in 68% there was bilobar disease. Best response to TACE treatment was: progressive disease (PD) 9%, stable disease (SD) 55%, partial remission (PR) 36%, and complete remission (CR) 0%. Multivariate regression analyses identified tumor size
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Quimioembolização Terapêutica , Óleo Iodado/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Adulto , Idoso , Carcinoma Hepatocelular/mortalidade , Quimioembolização Terapêutica/efeitos adversos , Cisplatino/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Masculino , Microesferas , Pessoa de Meia-Idade , AmidoRESUMO
AIM: To evaluate the treatment effect of percutaneous ethanol injection (PEI) for patients with advanced, non-resectable HCC compared with combination of transarterial chemoembolisation (TACE) and repeated single-session PEI, repeated single-session PEI alone, repeated TACE alone, or best supportive care. METHODS: All patients who received PEI treatment during the study period were included and stratified to one of the following treatment modalities according to physical status and tumor extent: combination of TACE and repeated single-session PEI, repeated single-session PEI alone, repeated TACE alone, or best supportive care. Prognostic value of clinical parameters including Okuda-classification, presence of portal vein thrombosis, presence of ascites, number of tumors, maximum tumor diameter, and serum cholinesterase (CHE), as well as Child-Pugh stage, alpha-fetoprotein (AFP), fever, incidence of complications were assessed and compared between the groups. Survival was determined using Kaplan-Meier and multivariate regression analyses. RESULTS: The 1- and 3-year survival of all patients was 73% and 47%. In the subgroup analyses, the combination of TACE and PEI (1) was associated with a longer survival (1-, 3-, 5-year survival: 90%, 52%, and 43%) compared to PEI treatment alone (2) (1-, 3-, 5-year survival: 65%, 50%, and 37%). Secondary PEI after initial stratification to TACE (3) yielded comparable results (1-, 3-, 5-year survival: 91%, 40%, and 30%) while PEI after stratification to best supportive care (4) was associated with decreased survival (1-, 3-, 5-year survival: 50%, 23%, 12%). Apart from the chosen treatment modalities, predictors for better survival were tumor number (n < 5), tumor size (< 5 cm), no ascites before PEI, and stable serum cholinesterase after PEI (P < 0.05). The mortality within 2 wk after PEI was 2.8% (n = 3). There were 24 (8.9%) major complications after PEI including segmental liver infarction, focal liver necrosis, and liver abscess. All complications could be managed non-surgically. CONCLUSION: Repeated single-session PEI is effective in patients with advanced HCC at an acceptable and manageable complication rate. Patients stratified to a combination of TACE and PEI can expect longer survival than those stratified to repeated PEI alone. Furthermore, patients with large or multiple tumors in good clinical status may also profit from a combination of TACE and reconsideration for secondary PEI.
Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Quimioembolização Terapêutica/métodos , Etanol/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Solventes/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica/efeitos adversos , Colinesterases/sangue , Cisplatino/administração & dosagem , Cisplatino/uso terapêutico , Progressão da Doença , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Etanol/administração & dosagem , Etanol/efeitos adversos , Feminino , Humanos , Injeções Intradérmicas , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Solventes/administração & dosagem , Solventes/efeitos adversos , Análise de Sobrevida , Resultado do Tratamento , alfa-Fetoproteínas/análiseRESUMO
BACKGROUND: Thiamin pyrophosphokinase (TPK) catalyzes the transfer of a pyrophosphate group from ATP to vitamin B1 (thiamin) to form the coenzyme thiamin pyrophosphate (TPP). Thus, TPK is important for the formation of a coenzyme required for central metabolic functions. TPK has no sequence homologs in the PDB and functions by an unknown mechanism. The TPK structure has been determined as a significant step toward elucidating its catalytic action. RESULTS: The crystal structure of Saccharomyces cerevisiae TPK complexed with thiamin has been determined at 1.8 A resolution. TPK is a homodimer, and each subunit consists of two domains. One domain resembles a Rossman fold with four alpha helices on each side of a 6 strand parallel beta sheet. The other domain has one 4 strand and one 6 strand antiparallel beta sheet, which form a flattened sandwich structure containing a jelly-roll topology. The active site is located in a cleft at the dimer interface and is formed from residues from domains of both subunits. The TPK dimer contains two compound active sites at the subunit interface. CONCLUSIONS: The structure of TPK with one substrate bound identifies the location of the thiamin binding site and probable catalytic residues. The structure also suggests a likely binding site for ATP. These findings are further supported by TPK sequence homologies. Although possessing no significant sequence homology with other pyrophospokinases, thiamin pyrophosphokinase may operate by a mechanism of pyrophosphoryl transfer similar to those described for pyrophosphokinases functioning in nucleotide biosynthesis.
Assuntos
Saccharomyces cerevisiae/genética , Tiamina Pirofosfoquinase/química , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência de Aminoácidos , Tiamina Pirofosfoquinase/metabolismo , Tiamina/metabolismoRESUMO
BACKGROUND: Fumarylacetoacetate hydrolase (FAH) catalyzes the final step of tyrosine and phenylalanine catabolism, the hydrolytic cleavage of a carbon-carbon bond in fumarylacetoacetate, to yield fumarate and acetoacetate. FAH has no known sequence homologs and functions by an unknown mechanism. Carbon-carbon hydrolysis reactions are essential for the human metabolism of aromatic amino acids. FAH deficiency causes the fatal metabolic disease hereditary tyrosinemia type I. Carbon-carbon bond hydrolysis is also important in the microbial metabolism of aromatic compounds as part of the global carbon cycle. RESULTS: The FAH crystal structure has been determined by rapid, automated analysis of multiwavelength anomalous diffraction data. The FAH polypeptide folds into a 120-residue N-terminal domain and a 300-residue C-terminal domain. The C-terminal domain defines an unusual beta-strand topology and a novel 'mixed beta-sandwich roll' structure. The structure of FAH complexed with its physiological products was also determined. This structure reveals fumarate binding near the entrance to the active site and acetoacetate binding to an octahedrally coordinated calcium ion located in close proximity to a Glu-His dyad. CONCLUSIONS: FAH represents the first structure of a hydrolase that acts specifically on carbon-carbon bonds. FAH also defines a new class of metalloenzymes characterized by a unique alpha/beta fold. A mechanism involving a Glu-His-water catalytic triad is suggested based on structural observations, sequence conservation and mutational analysis. The histidine imidazole group is proposed to function as a general base. The Ca(2+) is proposed to function in binding substrate, activating the nucleophile and stabilizing a carbanion leaving group. An oxyanion hole formed from sidechains is proposed to stabilize a tetrahedral alkoxide transition state. The proton transferred to the carbanion leaving group is proposed to originate from a lysine sidechain. The results also reveal the molecular basis for mutations causing the hereditary tyrosinemia type 1.
Assuntos
Carbono/química , Hidrolases/química , Aminoácidos/metabolismo , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Dimerização , Histidina , Humanos , Hidrolases/metabolismo , Hidrólise , Modelos Moleculares , Conformação Proteica , Dobramento de Proteína , ÁguaRESUMO
Thiamin pyrophosphate (TPP) is a coenzyme derived from vitamin B1 (thiamin). TPP synthesis in eukaryotes requires thiamin pyrophosphokinase (TPK), which catalyzes the transfer of a pyrophosphate group from ATP to thiamin. TPP is essential for central metabolic processes, including the formation of acetyl CoA from glucose and the Krebs cycle. Deficiencies in human thiamin metabolism result in beriberi and Wernicke encephalopathy. The crystal structure of mouse TPK was determined by multiwavelength anomalous diffraction at 2.4 A resolution, and the structure of TPK complexed with thiamin has been refined at 1.9 A resolution. The TPK polypeptide folds as an alpha/beta-domain and a beta-sandwich domain, which share a central ten-stranded mixed beta-sheet. TPK subunits associate as a dimer, and thiamin is bound in the dimer interface. Despite lacking apparent sequence homology with other proteins, the alpha/beta-domain resembles the Rossman fold and is similar to other kinase structures, including another pyrophosphokinase and a thiamin biosynthetic enzyme. Comparison of mouse and yeast TPK structures reveals differences that could be exploited in developing species-specific inhibitors of potential use as antimicrobial agents.
Assuntos
Tiamina Pirofosfoquinase/química , Animais , Sítios de Ligação , Cristalografia por Raios X , Dimerização , Desenho de Fármacos , Camundongos , Modelos Moleculares , Conformação Proteica , Subunidades Proteicas , Saccharomyces cerevisiae/enzimologia , Especificidade da Espécie , Tiamina Pirofosfoquinase/metabolismo , Tiamina/metabolismoRESUMO
The 3-D structure of the N-terminal SH3 domain of the regulatory protein Grb2 has been determined by X-ray analysis at 2.8 A resolution and refined to a crystallographic R factor of 21.5%. The structure, which is very similar to those of other SH3 domains, consists of two orthogonal, antiparallel up-down beta-sheets, with three variable loops and a 3(10) helix. Docking of the proline-rich peptide, 3BP1 on Grb2-N SH3, shows that the polyproline type II helix can bind the SH3 domain forming conserved hydrogen bonds between the main-chain carbonyl oxygens of Met4 and Pro7 of the proline-rich peptide and the reoriented side-chains of Trp36 and Asn51, respectively, and a hydrogen bond between the main-chain carbonyl of Leu8 of the proline rich peptide with the side-chain OH of Tyr52 of the Grb2-N SH3. The peptide side-chain binding occurs on the surface of SH3 domain at three major sites involving the side-chains of the residues in the hydrophobic patch (Tyr7, Phe9, Trp36, Phe47, Pro49 and Tyr52) and the RT-Src and n-Src loops of the SH3 domain. The proline-rich peptides could bind the Grb2-N SH3 in either orientation and maintain the key hydrogen bonds because of the pseudo-symmetry of the polyproline type II helix. However, for the mSos1 peptide a salt bridge can be formed between the arginine of the proline-rich peptide and the protein at Asp15, Glu16 and Glu31 only in one direction; this orientation seems to be strongly preferred. The conservatively varied RGD sequence motif (sometimes KGE or KGD) in SH3 domains might be involved in interactions at the cell membrane.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Modelos Moleculares , Estrutura Terciária de Proteína , Proteínas/química , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Proteína Adaptadora GRB2 , Ligação de Hidrogênio , Dados de Sequência Molecular , Peptídeos , Dobramento de Proteína , Proteínas/genética , Proteínas Recombinantes de Fusão/biossíntese , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
Programmes for the eradication and control of infections with bovine viral diarrhea virus (BVDV) concentrate on the identification and elimination of persistently infected (PI) animals. The identification of these animals is mainly based on the detection of viral antigen using ELISA techniques. Protocols detecting viral nucleic acid using RT-PCR have been described recently. Due to high costs the German model recommends screening of animals of 9 up to 36 months of age. Screening of bulk milk samples using RT-PCR technology would allow a system independent of age. The aim of the present study was to test whether bulk milk samples (1433 including max. 50 animals each) collected in four counties of Lower Saxony are suitable for a complementary identification of PI animals via RT-PCR. Thirty-one bulk milk samples derived from 27 dairy herds were BVDV positive, corresponding to 2.3 % of the herds analysed in this study. Two samples first scored doubtful. Follow up tests revealed lactating PI animals in most cases (18). In other cases the epidemiological status of the herd, i.e. high sero-prevalence and/or presence of PI animals among non-lactating cattle, suggested a transient infection detected in the first bulk milk sample. These results demonstrate that monitoring of lactating cattle of any age using RT-PCR is a very sensitive, economically effective additional method for the identification of PI animals.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Vírus da Diarreia Viral Bovina/isolamento & purificação , Leite/virologia , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Bovinos , Vírus da Diarreia Viral Bovina/genética , Feminino , Alemanha/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e EspecificidadeRESUMO
A crystal structure of the serine protease, mouse glandular kallikrein 13 (mGK-13) has been determined at 2.6-A resolution. This enzyme, isolated from the mouse submandibular gland, is also known as prorenin-converting enzyme and cleaves submandibular gland Ren-2 prorenin to yield active renin. The mGK-13 structure is similar to other members of the mammalian serine protease family, having five conserved disulfide bonds and an active site located in the cleft between two beta-barrel domains. The mGK-13 structure reveals for the first time an ordered kallikrein loop conformation containing a short 3(10) helix. This loop is disordered in the related porcine pancreatic kallikrein and rat submandibular tonin structures. The kallikrein loop is in close spatial proximity to the active site and is also involved in a dimeric arrangement of mGK-13. The catalytic specificity of mGK-13 for Ren-2 prorenin was studied by modeling a prorenin-derived peptide into the active site of mGK-13. This model emphasizes two electronegative substrate specificity pockets on the mGK-13 surface, which could accommodate the dibasic P2 and P1 residues at the site of prorenin cleavage by mGK-13.
Assuntos
Cisteína Endopeptidases/química , Estrutura Terciária de Proteína , Glândula Submandibular/enzimologia , Animais , Sítios de Ligação , Cristalografia por Raios X , Masculino , Camundongos , Modelos Moleculares , Homologia de Sequência de AminoácidosRESUMO
Equilibrium denaturation of dimeric mouse beta-nerve growth factor (beta-NGF) has been studied by monitoring changes in the protein's spectroscopic characteristics. Denaturation of beta-NGF in guanidine hydrochloride and urea resulted in an altered intrinsic fluorescence emission spectrum, fluorescence depolarization, and diminished negative circular dichroism. Native-like spectroscopic properties and specific biological activity are restored when denaturant is diluted from unfolded samples, demonstrating that this process is fully reversible. However, refolding of denatured beta-NGF is dependent on the three disulfide bonds present in the native protein and does not readily occur when the disulfide bonds are reduced. Graphical analysis and nonlinear least-squares fitting of beta-NGF denaturation data demonstrate that denaturation is dependent on the concentration of beta-NGF and is consistent with a two-state model involving native dimer and denatured monomer (N2 = 2D). The conformational stability of mouse beta-NGF calculated according to this model is 19.3 +/- 1.1 kcal/mol in 100 mM sodium phosphate at pH 7. Increasing the hydrogen ion concentration resulted in a 25% decrease in beta-NGF stability at pH 4 relative to pH 7.
Assuntos
Fatores de Crescimento Neural/química , Desnaturação Proteica , Animais , Dicroísmo Circular , Relação Dose-Resposta a Droga , Guanidina , Guanidinas/farmacologia , Concentração de Íons de Hidrogênio , Camundongos , Fatores de Crescimento Neural/efeitos dos fármacos , Dobramento de Proteína , Espectrometria de Fluorescência , Raios Ultravioleta , Ureia/farmacologiaRESUMO
The conformational stability of dimeric globular proteins can be measured by equilibrium denaturation studies in solvents such as guanidine hydrochloride or urea. Many dimeric proteins denature with a 2-state equilibrium transition, whereas others have stable intermediates in the process. For those proteins showing a single transition of native dimer to denatured monomer, the conformational stabilities, delta Gu (H2O), range from 10 to 27 kcal/mol, which is significantly greater than the conformational stability found for monomeric proteins. The relative contribution of quaternary interactions to the overall stability of the dimer can be estimated by comparing delta Gu (H2O) from equilibrium denaturation studies to the free energy associated with simple dissociation in the absence of denaturant. In many cases the large stabilization energy of dimers is primarily due to the intersubunit interactions and thus gives a rationale for the formation of oligomers. The magnitude of the conformational stability is related to the size of the polypeptide in the subunit and depends upon the type of structure in the subunit interface. The practical use, interpretation, and utility of estimation of conformational stability of dimers by equilibrium denaturation methods are discussed.
Assuntos
Conformação Proteica , Ligantes , Ligação Proteica , Desnaturação Proteica , Solventes/farmacologia , TermodinâmicaRESUMO
Interactions between the purified recombinant receptor extracellular domain (RED) of the human low-affinity neurotrophin receptor (LANR) and recombinant human brain-derived neurotrophic factor, neurotrophin-3 (NT-3) and neuotrophin-4/5 have been studied by chemical crosslinking and circular dichroism. Conformational changes subsequent to binding have been shown by these procedures. First, relative affinities of the neurotrophins for RED were determined by binding competition assays in which radioiodinated nerve growth factor (NGF) from mouse submaxillary gland was crosslinked to RED in the presence of varying amounts of unlabeled neurotrophin competitors. RED bound each of the 3 recombinant human neurotrophins with affinities that were indistinguishable from authentic mouse NGF. These results are the first measurement of binding of the neurotrophin family to their common receptor using purified components. In order to study the effect of binding on the conformation of the proteins, CD measurements were made before and after mixing neurotrophins and RED, as had previously been done with NGF and RED (Timm DE, Vissavajjhala P, Ross AH, Neet KE, 1992, Protein Sci 1:1023-1031). Similar changes in CD spectra occurred upon combination of each of the neurotrophins and RED, with negative changes near 220-225 nm and positive changes near 190-200 nm; however, significant differences existed among the various neurotrophin-RED difference spectra. The NT-3/RED complex showed the largest spectral change and NGF the smallest. Thus, specific conformational changes in secondary structure of neurotrophin, RED, or both accompany the binding of each neurotrophin to the extracellular domain of the LANR.
Assuntos
Fatores de Crescimento Neural/química , Receptores de Fator de Crescimento Neural/química , Ligação Competitiva , Dicroísmo Circular , Reagentes de Ligações Cruzadas , Humanos , Técnicas In Vitro , Modelos Químicos , Fatores de Crescimento Neural/metabolismo , Conformação Proteica , Receptores de Fator de Crescimento Neural/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismoRESUMO
Nerve growth factor (NGF) interacts with a cell surface receptor on responsive neurons to initiate a series of cellular events leading to neuronal survival and/or differentiation. The first step in this process is the binding of NGF to a low affinity and/or a high affinity receptor. In the present report, we have studied the conformation and stability of recombinant receptor extracellular domain (RED) from the human low affinity receptor and the structural basis of its interaction with NGF. Circular dichroism (CD) studies indicate that the RED is primarily random coil in nature with little regular secondary structure. Thermal stability studies have shown that this irregular conformation is a specific structure that can undergo a reversible two-state thermal denaturation with a concomitant fluorescent and CD change. During heating at 100 degrees C for 15 min, the structure of RED is sufficiently unfolded for a reducing agent, dithiothreitol, to inactivate the receptor toward NGF binding and cross-linking. The complex formation between the RED and NGF has been examined by differential CD measurements, and we have shown that a small, reproducible change in conformation occurs in RED or NGF upon interaction. These results are interpreted in terms of the initiation of NGF cell surface binding and possible modes of signal transduction.
Assuntos
Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Estrutura Secundária de Proteína , Receptores de Fator de Crescimento Neural/química , Receptores de Fator de Crescimento Neural/metabolismo , Animais , Linhagem Celular , Dicroísmo Circular , Humanos , Cinética , Camundongos , Mariposas , Desnaturação Proteica , Dobramento de Proteína , Receptores de Fator de Crescimento Neural/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Espectrometria de Fluorescência , Glândula Submandibular/metabolismo , TransfecçãoRESUMO
The mouse major urinary proteins are pheromone-binding proteins that function as carriers of volatile effectors of mouse physiology and behavior. Crystal structures of recombinant mouse major urinary protein-I (MUP-I) complexed with the synthetic pheromones, 2-sec-butyl-4,5-dihydrothiazole and 6-hydroxy-6-methyl-3-heptanone, have been determined at high resolution. The purification of MUP-I from mouse liver and a high-resolution structure of the natural isolate are also reported. These results show the binding of 6-hydroxy-6-methyl-3-heptanone to MUP-I, unambiguously define ligand orientations for two pheromones within the MUP-I binding site, and suggest how different chemical classes of pheromones can be accommodated within the MUP-I beta-barrel.
Assuntos
Feromônios/metabolismo , Proteínas/química , Proteínas/metabolismo , Animais , Sítios de Ligação , Cristalografia por Raios X , Ligação de Hidrogênio , Fígado/química , Camundongos , Modelos Moleculares , Feromônios/síntese química , Feromônios/química , Ligação Proteica , Estrutura Secundária de Proteína , Relação Estrutura-AtividadeRESUMO
Passing galvanic current across the skin (known as "tap water iontophoresis" or TWI) inhibits sweating; however, its mechanism of action is unclear. Using improved methods, we confirmed that anodal current has more of an inhibitory effect than cathodal current, water is superior to saline, and the inhibitory effect is a function of the amperage used. To address the importance of current flowing through the pores, a layer of silicone grease was placed on the skin to reduce the shunt pathway across the epidermis. With silicone, total skin conductance decreased 60% without the sweat pores being occluded, swelling of the stratum corneum and collapse of the poral lumen was prevented, and current-induced inhibition of sweating was enhanced, most likely because of an increase in current density in the pores. The pH of anodal water, but not of saline, dropped to 3, whereas that of cathodal water increased to 10 during passage of current through the skin. Acidified anodal water was superior to alkaline water. Sweat glands isolated from TWI-induced anhidrotic palmar skin responded to methacholine in vitro, but the sweat rate and pharmacological sensitivity were slightly lowered. Thus the strong acidity generated by hydrolysis of water in the anodal bath and the further accumulation of H+ in the sweat duct by anodal current may be responsible for TWI-induced inhibition of sweating due to an unknown lesion(s) in the duct or sweat pore. The secretory coil function may also be altered because of exposure to intense acidity during TWI. The importance of H+ movement into the sweat pore for inhibition of sweating could be further exploited to develop new strategies for the control of sweating.
Assuntos
Hiperidrose/fisiopatologia , Prótons , Sudorese/fisiologia , Água , Adolescente , Adulto , Estimulação Elétrica , Feminino , Resposta Galvânica da Pele/fisiologia , Mãos/fisiologia , Humanos , Concentração de Íons de Hidrogênio , Hiperidrose/terapia , Técnicas In Vitro , Iontoforese , Masculino , Silicones , Fenômenos Fisiológicos da Pele , Glândulas Sudoríparas/fisiologiaRESUMO
Despite recent progress in eccrine sweat gland physiology, simple, safe and reliable methods of visualizing local and generalized sweating are not available for clinicians and physiologists. We developed a simple one-step method for visualizing sweating that requires only soluble starch previously treated with iodine. When the powder is sprayed on the skin, sweat droplets are visualized as discrete dark purple dots. Since visualized dots are easily wiped off without staining the skin, sweating patterns can be obtained consecutively on the same skin site. The method is far superior to the classical Minor's method and is useful for clinical diagnosis of disorders of sweating and for visualization of the total body sweating for physiological studies. Two simple devices for spraying powder also have been presented.
Assuntos
Iodo , Amido , Sudorese , Feminino , Humanos , Hiperidrose/diagnóstico , Iodo/administração & dosagem , Pessoa de Meia-Idade , Nebulizadores e Vaporizadores , Amido/administração & dosagemRESUMO
The insulin-content in islets of Langerhans on sand rats with disturbances of the carbon hydrate tolerance (reference-, impaired glucose tolerance-, and diabetic group) is measured cytophotometrically. In the IGT-group (impaired glucose tolerance) is a decrease of the insulin content in B-cells detectable. However in the diabetic group of sand rats is the insulin-content increased. This results demonstrate the stimulation of the B-cell function in the islets of Langerhans. The diabetes mellitus of sand rats is characterized by disturbed glucose tolerance hyperinsulinaemia, and elevated readiness to insulin secretion. That are characteristics of the human type-II-diabetes (insulin-independent). In conclusion, the sand rat is a biological model of the human type-II-diabetes (NIDDM).
Assuntos
Diabetes Mellitus Experimental/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Animais , Arvicolinae , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , HistocitoquímicaRESUMO
Heterotopia of thyroid gland can be seen very seldom in humans. Most frequently ectopic thyroid tissue is found in the middle line of neck and chest. Ectopia of thyroid tissue caudal of the diaphragm is an exceptionally rare finding. An explanation results out of the embryology of the thyroid gland development. Reviewing the literature we could find only one case of accessory thyroid tissue in the region of the hepatic porta, it was found at autopsy. In the present case report we describe a 58-year-old woman who had an indistinct tumor in the hepatic porta which was successfully removed. Histologic findings was that of aberrant normal thyroid tissue.
Assuntos
Coristoma/cirurgia , Neoplasias Hepáticas/cirurgia , Glândula Tireoide , Coristoma/patologia , Feminino , Humanos , Fígado/patologia , Neoplasias Hepáticas/patologia , Pessoa de Meia-IdadeRESUMO
During the first four years of its existence, the Drug and Poison Information Service at King Khalid University Hospital established itself as an integral part of the clinical pharmacy program and was appreciated by the medical staff. In terms of references and request categories it was similar to the UMDIS. Differences result from dissimilar formularies and a large number of physician inquiries, as opposed to the large number of consumer inquiries received at the UMDIS.
Assuntos
Serviços de Informação sobre Medicamentos/estatística & dados numéricos , Centros de Controle de Intoxicações/estatística & dados numéricos , Coleta de Dados , Hospitais com mais de 500 Leitos , Hospitais Universitários/estatística & dados numéricos , Minnesota , Serviço de Farmácia Hospitalar/estatística & dados numéricos , Arábia SauditaRESUMO
Comprehensive serological and virological monitoring for bovine viral diarrhoea (BVD) virus was applied in a dairy herd. Out of 83 calves 26 persistently infected animals were identified. Four viremic calves showed clinical signs of disease, the others displayed no symptoms. Viral isolates from persistently infected animals were homogenous with respect to their antigenicity. The results of virological and serological investigations allowed an almost complete reconstruction of events following the introduction of BVD virus into the herd. This case illustrates the potentially dangerous and damaging effects of unidentified virus carriers in cattle herds. Strategies for the identification of virus-shedding animals and the limitation of economical losses are discussed.