RESUMEN
Mouse hepatitis coronavirus (MHV) buds into pleomorphic membrane structures with features expected of the intermediate compartment between the ER and the Golgi complex. Here, we characterize the MHV budding compartment in more detail in mouse L cells using streptolysin O (SLO) permeabilization which allowed us to better visualize the membrane structures at the ER-Golgi boundary. The MHV budding compartment shares membrane continuities with the rough ER as well as with cisternal elements on one side of the Golgi stack. It also labeled with p58 and rab2, two markers of the intermediate compartment, and with PDI, usually considered to be a marker of the rough ER. The membranes of the budding compartment, as well as the budding virions themselves, but not the rough ER, labeled with the N-acetyl-galactosamine (GalNAc)-specific lectin Helix pomatia. When the SLO-permeabilized cells were treated with guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), the budding compartment accumulated a large number of beta-cop-containing buds and vesicular profiles. Complementary biochemical experiments were carried out to determine whether vesicular transport was required for the newly synthesized M protein, that contains only O-linked oligosaccharides, to acquire first, GalNAc and second, the Golgi modifications galactose and sialic acid. The results from both in vivo studies and from the use of SLO-permeabilized cells showed that, while GalNAc addition occurred under conditions which block vesicular transport, both cytosol and ATP were prerequisites for the M protein oligosaccharides to acquire Golgi modifications. Collectively, our data argue that transport from the rough ER to the Golgi complex requires only one vesicular transport step and that the intermediate compartment is a specialized domain of the endoplasmatic reticulum that extends to the first cisterna on the cis side of the Golgi stack.
Asunto(s)
Virus de la Hepatitis Murina/crecimiento & desarrollo , Acetilgalactosamina/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Proteínas Bacterianas , Transporte Biológico , Compartimento Celular , Permeabilidad de la Membrana Celular , Proteína Coatómero , Retículo Endoplásmico/metabolismo , Proteínas de Unión al GTP/metabolismo , Glicoconjugados/metabolismo , Glicoproteínas/metabolismo , Glicosilación , Aparato de Golgi/metabolismo , Guanosina Trifosfato/metabolismo , Inmunohistoquímica , Isomerasas/metabolismo , Células L , Ratones , Proteínas Asociadas a Microtúbulos/metabolismo , Proteína Disulfuro Isomerasas , Estreptolisinas , Temperatura , Proteínas de la Matriz Viral/metabolismo , Proteínas Virales/metabolismo , Proteína de Unión al GTP rab2RESUMEN
We have investigated the sorting and processing of the amphibian precursor prepro-dermorphin in mammalian cells. Dermorphin, a D-alanine-containing peptide with potent opioid activity, has been isolated from the skin of the frog Phyllomedusa sauvagei. The maturation of this peptide from the precursor involves several posttranslational steps. Recombinant vaccinia viruses were used to infect AtT-20, PC12, and HeLa cells to study the sorting and processing of prepro-dermorphin. While this precursor was not processed in any of the examined cell lines, AtT-20 cells were able to process approximately 40% of a chimeric precursor consisting of the first 241 amino acids of prepro-enkephalin fused to a carboxy-terminal part of pro-dermorphin. By immunogold-EM, we could show that the chimeric protein, but not pro-dermorphin, was sorted to dense-core secretion granules. The processing products could be released upon stimulation by 8-Br-cAMP. We conclude that the pro-enkephalin part of the fusion protein contains the information for targeting to the regulated pathway of secretion, while this sorting information is missing in pro-dermorphin. This indicates that sorting mechanisms may differ between amphibian and mammalian cells.
Asunto(s)
Encefalinas/genética , Oligopéptidos/genética , Precursores de Proteínas/genética , Procesamiento Proteico-Postraduccional , 8-Bromo Monofosfato de Adenosina Cíclica/farmacología , Secuencia de Aminoácidos , Animales , Anuros , Línea Celular , Quimera , Gránulos Citoplasmáticos/metabolismo , Gránulos Citoplasmáticos/ultraestructura , Encefalinas/biosíntesis , Humanos , Cinética , Microscopía Inmunoelectrónica , Plásmidos , Precursores de Proteínas/biosíntesis , Proteínas Recombinantes de Fusión/biosíntesis , Transfección , Virus Vaccinia/genéticaRESUMEN
The carboxyl-terminal Lys-Asp-Glu-Leu (KDEL), or a closely-related sequence, is important for ER localization of both lumenal as well as type II membrane proteins. This sequence functions as a retrieval signal at post-ER compartment(s), but the exact compartment(s) where the retrieval occurs remains unresolved. With an affinity-purified antibody against the carboxyl-terminal sequence of the mammalian KDEL receptor, we have investigated its subcellular localization using immunogold labeling on thawed cryosections of different tissues, such as mouse spermatids and rat pancreas, as well as HeLa, Vero, NRK, and mouse L cells. We show that rab1 is an excellent marker of the intermediate compartment, and we use this marker, as well as budding profiles of the mouse hepatitis virus (MHV) in cells infected with this virus, to identify this compartment. Our results demonstrate that the KDEL receptor is concentrated in the intermediate compartment, as well as in the Golgi stack. Lower but significant labeling was detected in the rough ER. In general, only small amounts of the receptor were detected on the trans side of the Golgi stack, including the trans-Golgi network (TGN) of normal cells and tissues. However, some stress conditions, such as infection with vaccinia virus or vesicular stomatitis virus, as well as 20 degrees C or 43 degrees C treatment, resulted in a significant shift of the distribution towards the trans-TGN side of the Golgi stack. This shift could be quantified in HeLa cells stably expressing a TGN marker. No significant labeling was detected in structures distal to the TGN under all conditions tested. After GTP gamma S treatment of permeabilized cells, the receptor was detected in the beta-COP-containing buds/vesicles that accumulate after this treatment, suggesting that these vesicles may transport the receptor between compartments. We propose that retrieval of KDEL-containing proteins occurs at multiple post-ER compartments up to the TGN along the exocytotic pathway, and that within this pathway, the amounts of the receptor in different compartments varies according to physiological conditions.
Asunto(s)
Compartimento Celular , Aparato de Golgi/química , Membranas Intracelulares/química , Oligopéptidos/metabolismo , Señales de Clasificación de Proteína , Receptores de Péptidos/aislamiento & purificación , Animales , Proteínas Bacterianas/metabolismo , Biomarcadores , Polaridad Celular , Células Cultivadas , Exocitosis/efectos de los fármacos , Exocitosis/fisiología , Proteínas de Unión al GTP/inmunología , Proteínas de Unión al GTP/aislamiento & purificación , Aparato de Golgi/ultraestructura , Guanosina 5'-O-(3-Tiotrifosfato)/farmacología , Humanos , Membranas Intracelulares/ultraestructura , Masculino , Microscopía Inmunoelectrónica , Virus de la Hepatitis Murina/crecimiento & desarrollo , Receptores de Péptidos/inmunología , Espermátides/química , Espermátides/ultraestructuraRESUMEN
Vaccinia virus, the prototype of the Poxviridae, is a large DNA virus which replicates in the cytoplasm of the host cell. The assembly pathway of vaccinia virus displays several unique features, such as the production of two structurally distinct, infectious forms. One of these, termed intracellular naked virus (INV), remains cells associated while the other, termed extracellular enveloped virus (EEV), is released from the cell. In addition, it has long been believed that INVs acquire their lipid envelopes by a unique example of de novo membrane biogenesis. To examine the structure and assembly of vaccinia virus we have used immunoelectron microscopy using antibodies to proteins of different subcellular compartments as well as a phospholipid analysis of purified INV and EEV. Our data are not consistent with the de novo model of viral membrane synthesis but rather argue that the vaccinia virus DNA becomes enwrapped by a membrane cisterna derived from the intermediate compartment between the ER and the Golgi stacks, thus acquiring two membranes in one step. Phospholipid analysis of purified INV supports its derivation from an early biosynthetic compartment. This unique assembly process is repeated once more when the INV becomes enwrapped by an additional membrane cisterna, in agreement with earlier reports. The available data suggest that after fusion between the outer envelope and the plasma membrane, mature EEV is released from the cell.
Asunto(s)
Membranas Intracelulares/microbiología , Virus Vaccinia/crecimiento & desarrollo , Retículo Endoplásmico/microbiología , Aparato de Golgi/microbiología , Células HeLa/microbiología , Células HeLa/ultraestructura , Humanos , Membranas Intracelulares/ultraestructura , Modelos Biológicos , Virus Vaccinia/patogenicidad , Virus Vaccinia/ultraestructura , Esparcimiento de VirusRESUMEN
Today's doping tests involve longitudinal monitoring of urinary steroids including the testosterone glucuronide and epitestosterone glucuronide ratio (T/E) in an Athlete Biological Passport (ABP). The aim of this study was to investigate the possible influence of short-term use of codeine on the urinary excretion of androgen metabolites included in the steroidal module of the passport prior to and after the co-administration with testosterone. The study was designed as an open study with the subjects being their own control. Fifteen healthy male volunteers received therapeutic doses of codeine (Kodein Meda) for 6 days. On Day 3, 500 mg or 125 mg of testosterone enanthate (Testoviron®-Depot) was administered. Spot urine samples were collected for 17 days, and blood samples were collected at baseline, 3, 6, and 14 days after codeine intake. The circulatory concentration of total testosterone decreased significantly by 20% after 3 days' use of codeine (p = 0.0002) and an atypical ABP result was noted in one of the subjects. On the other hand, the concomitant use of codeine and testosterone did not affect the elevated urinary T/E ratio. In 75% of the individuals, the concentration of urinary morphine (a metabolite of codeine) was above the decision limit for morphine. One of the participants displayed a morphine/codeine ratio of 1.7 after codeine treatment, indicative of morphine abuse. In conclusion, our study shows that codeine interferes with the endogenous testosterone concentration. As a result, the urinary steroid profile may lead to atypical findings in the doping test.
Asunto(s)
Andrógenos/sangre , Andrógenos/orina , Codeína/sangre , Codeína/orina , Detección de Abuso de Sustancias/métodos , Testosterona/sangre , Testosterona/orina , Adolescente , Adulto , Cromatografía Líquida de Alta Presión/métodos , Doping en los Deportes , Humanos , Límite de Detección , Masculino , Persona de Mediana Edad , Morfina/orina , Espectrometría de Masas en Tándem/métodos , Testosterona/análogos & derivados , Adulto JovenRESUMEN
Polycystin, the product of autosomal dominant polycystic kidney disease (ADPKD) 1 gene (PKD1) is the cardinal member of a novel class of proteins. As a first step towards elucidating the function of polycystin and the pathogenesis of ADPKD, three types of information were collected in the current study: the subcellular localization of polycystin, the spatial and temporal distribution of the protein within normal tissues and the effects of ADPKD mutations on the pattern of expression in affected tissues. Antisera directed against a synthetic peptide and two recombinant proteins of different domains of polycystin revealed the presence of an approximately 400-kD protein (polycystin) in the membrane fractions of normal fetal, adult, and ADPKD kidneys. Immunohistological studies localized polycystin to renal tubular epithelia, hepatic bile ductules, and pancreatic ducts, all sites of cystic changes in ADPKD, as well as in tissues such as skin that are not known to be affected in ADPKD. By electron microscopy, polycystin was predominantly associated with plasma membranes. Polycystin was significantly less abundant in adult than in fetal epithelia. In contrast, polycystin was overexpressed in most, but not all, cysts in ADPKD kidneys.
Asunto(s)
Riñón Poliquístico Autosómico Dominante/genética , Proteínas/metabolismo , Anticuerpos/inmunología , Anticuerpos/metabolismo , Western Blotting , Membrana Celular/química , Clonación Molecular , Embrión de Mamíferos/metabolismo , Regulación de la Expresión Génica/genética , Humanos , Inmunohistoquímica , Túbulos Renales/química , Hígado/química , Hígado/citología , Microscopía Inmunoelectrónica , Páncreas/química , Páncreas/citología , Proteínas/inmunología , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Piel/química , Piel/citología , Canales Catiónicos TRPPRESUMEN
Two different techniques have been used to study the complex formation of recombinant human plasminogen activator inhibitor type-1, PAI-1, with either recombinant human two-chain tissue plasminogen activator, tc tPA (EC 3.4.21.68), or the tPA deletion variants tc K2P, containing the kringle 2 domain and the proteinase domain, and P, containing only the proteinase domain. The same value for Kon, 2.10(7) M-1s-1 for binding of PAI-1 was found for the three tPA forms by direct detection of the complex formation in real time by surface plasmon resonance, BIAcore, or indirectly by monitoring the time course of the inhibition of tPA using the chromogenic substrate N-methylsulfonyl-D-Phe-Gly-Arg-4-pNA-acetate. Apparently, no conformational change is involved in the rate-limiting step, since the kon value was found to be independent of the temperature from 20 to 35 degrees C. By the BIAcore technique, it was found that the complex between PAI-1 and tPA covalently coupled to the surface, was stable at 25 degrees C, since no dissociation was seen in buffer. However, extended treatment with 1 M NH4OH destroyed the complex with t 1/2 = 5 h. The same kon values and complex composition were found by measuring either the binding of tPA to PAI-1 captured on the monoclonal antibody MAI-11 or the binding of PAI-1 to tPA captured on the monoclonal antibody 2:2 B10. Quantification of the complex composition between PAI-1 captured on the monoclonal antibody MAI-11 with either tPA, K2P or P gave a one-to-one ratio with the fraction of active PAI-1, consistent with the results from SDS-PAGE and the specific activity of PAI-1. The complexes of the three tPA forms with PAI-1 captured on a large surface of MAI-11 dissociated more rapidly from MAI-11, with the same apparent koff, kdis, = 2.10(-3) s-1, compared with 0.7-10(-3) s-1 for the dissociation of PAI-1 alone. In consistance, the Kd, calculated from the direct determination of the kon and koff for the association of different form of PAI-1 to a small surface of MAI-11, was found to be higher for PAI-1 in complex with tPA than for free active PAI-1. Apparently, upon complex formation, a change is induced in PAI-1 at the binding epitope for MAI-11.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Endopeptidasas/química , Inhibidor 1 de Activador Plasminogénico/farmacología , Activador de Tejido Plasminógeno/química , Secuencia de Aminoácidos , Compuestos Cromogénicos/química , Cinética , Datos de Secuencia Molecular , Oligopéptidos/químicaRESUMEN
OBJECTIVES: The objectives of this study were to examine children with previous manifest neuroborreliosis and concommitant facial palsy to see whether there were any persisting symptoms and/or signs of persistent residual facial palsy. STUDY DESIGN: Open, controlled prospective study. SETTING: Tertiary referral center (University Hospital). PATIENTS: The study was conducted on twenty-four patients with clinically manifest neuroborreliosis and facial palsy 3 to 5 years prior to the investigation. MAIN OUTCOME MEASURES: Results of the clinical examination using the House-Brackmann scale were compared to results from two neuro-physiological examinations (qEMG and ENoG). RESULTS: Approximately one-half of the patients with reported subjective symptoms of residual facial palsy had signs of slight dysfunction in the clinical examination using the House-Brackmann scale. There was no correlation between the subjective feeling of facial dysfunction and presence of clinical signs. Likewise, about one-half of the subjective facial dysfunction group, as well as the control group, were found to demonstrate pathological values in their neurophysiological examinations using qEMG and ENoG. CONCLUSIONS: This study shows that the assumption is not true that all children who had neuroborreliosis with facial palsy will heal 100%. A small proportion of the children claim that several years after the infection, they have subjective symptoms of slight facial weakness on the affected side. Our study shows that some of these children, as well as some children without subjective symptoms of facial palsy, demonstrate a slight facial weakness when examined clinically. Likewise, signs of slight-to-moderate facial motor dysfunction were revealed in about half of the children with the two neurophysiological methods utilized in this study. It is interesting to note that there was no clear correlation between the presence of subjective symptoms, objective signs, and neurophysiological results.
Asunto(s)
Parálisis Facial/microbiología , Parálisis Facial/fisiopatología , Neuroborreliosis de Lyme , Niño , Preescolar , Electrodiagnóstico , Electromiografía , Músculos Faciales/fisiopatología , Parálisis Facial/complicaciones , Parálisis Facial/diagnóstico , Femenino , Humanos , Estudios Longitudinales , Masculino , Debilidad Muscular/etiología , Debilidad Muscular/fisiopatologíaRESUMEN
The effect of somatostatin on thyroid hormone secretion stimulated by TSH in man was studied. The injection of TSH into a thyroid artery during surgery was followed by an increase in the serum concentration of iodothyronines in the corresponding thyroid vein. This increase was significantly lower (p less than 0.02) when somatostatin was given as a bolus injection into a peripheral vein 5 min prior to the administration of TSH, and followed by a continuous infusion for 60 min. Since somatostatin-like immunoreactivity has been localized to some cells of the thyroid gland being in a parafollicular location, it is suggested that somatostatin may be an intrathyroidal regulator of thyroid activity in man.
Asunto(s)
Somatostatina/farmacología , Glándula Tiroides/metabolismo , Hormonas Tiroideas/metabolismo , Tirotropina , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Glándula Tiroides/irrigación sanguínea , Glándula Tiroides/efectos de los fármacos , Tiroxina/sangre , Triyodotironina/sangre , Triyodotironina Inversa/sangre , VenasRESUMEN
Liver alcohol dehydrogenase of the ethanol-active type ('class I enzyme') from the lizard, Uromastix hardwickii, was purified and screened for relationships with other vertebrate forms of the enzyme. Two different acetylated N-termini (acetyl-Gly and acetyl-Ser) and further positional differences already in the N-terminal segments establish the presence of two types of protein chain. The multiplicity is different from that hitherto detected within vertebrate class I alcohol dehydrogenase isozymes but typical of that which would be expected for subunits of different classes. In particular, relationships to class II or to class II-related forms appear likely. This may indicate yet further vertebrate alcohol dehydrogenase multiplicity or discovery of a class II non-mammalian enzyme. The results give prospects of defining gene duplications corresponding to more than one alcohol dehydrogenase class split to at an early vertebrate stage.
Asunto(s)
Alcohol Deshidrogenasa/metabolismo , Isoenzimas/metabolismo , Alcohol Deshidrogenasa/química , Alcohol Deshidrogenasa/clasificación , Secuencia de Aminoácidos , Animales , Cromatografía Líquida de Alta Presión , Isoenzimas/química , Hígado/enzimología , Lagartos , Mamíferos , Datos de Secuencia Molecular , Alineación de SecuenciaRESUMEN
Preparative ultracentrifugal and electrophoretic analysis of serum lipoproteins was performed in 30-70-year-old healthy, fasting males (N = 80) and females (N = 77), randomly selected from the Uppsala region, Sweden. The concentrations of cholesterol and triglycerides in total serum and in VLDL,LDL and HDL lipoprotein classes are reported. Total serum, VLDL and LDL triglycerides and cholesterol concentrations increased with age, while HDL cholesterol and triglyceride concentrations did not vary with age. Overweight persons had higher total serum triglyceride, higher VLDL cholesterol and triglyceride and lower HDL cholesterol levels. The upper 90% population limit values for non-overweight males/females were: total triglycerides (mmol/l) 2.5/2.0, total cholesterol (mg/100 ml) 298/300, VLDL triglyceride 1.80/1.05, VLDL-cholesterol 32/33, LDL triglyceride 0.69/0.69, LDL cholesterol 210/218, HDL triglyceride 0.32/0.34 and HDL-cholesterol 69/93. The 2 major differences between males and females were that females had lower VLDL but higher HDL concentrations. For VLDL there was a very strong and for LDL a moderately strong positive correlation between cholesterol and triglyceride contents. In HDL however, the mearsured amounts of cholesterol and triglycerides did not correlate at all. Sinking pre-beta lipoproteins was found in about 25% of cases and a second pre-beta band floating at d 1.006, late pre-beta, was found in 35% of male and 25% of female subjects. Subjects with sinking pre-beta lipoprotein did not differ from other subjects with regard to the concentration of cholesterol and triglycerides in the 3 lipoprotein classes. Males, but not females, with the late pre-beta (LPB), had an increased amount of cholesterol in VLDL and a raised cholesterol-triglyceride ratio in this lipoprotein class. Also the LDL triglyceride level was increased in males with the late pre-beta lipoprotein.
Asunto(s)
Lipoproteínas/sangre , Factores de Edad , Electroforesis de las Proteínas Sanguíneas , Colesterol/sangre , Femenino , Humanos , Masculino , Obesidad/metabolismo , Sefarosa , Factores Sexuales , Triglicéridos/sangre , UltracentrifugaciónRESUMEN
The fasting concentration of cholesterol and triglycerides in serum and in very low (VLDL), low (LDL) and high (HDL) density lipoproteins (LP) was determined 3 months after a myocardial infarction (MI) in 54 men, and the values obtained were compared to those in 61 healthy male control subjects. The mean triglyceride concentration in MI patients was significantly increased in serum, VLDL, LDL and HDL by 74%, 110%, 30% and 12% respectively, compared to controls. The mean cholesterol concentration was significantly raised by 16%, 120% and 14% in serum, VLDL and LDL but decreased by 22% in HDL. Hypertriglyceridaemia occurred in 58% of MI patients. Of these patients, two-fifths had hypertriglyceridaemia only and three-fifths had combined hyperlipidaemia. The hypertriglyceridaemia was caused by elevation of only VLDL triglycerides in 26%, only LDL triglycerides in 19%, VLDL and LDL triglycerides in 23% and by various other combinations of raised LP triglyceride levels in 25% of cases. Hypercholesterolaemia was found in 41% of MI subjects. Of these, one-sixth had elevation of cholesterol levels, while five-sixths had combined hyperlipidaemia. The LP abnormalities underlying hypercholesterolaemia were increased of only VLDL cholesterol levels in 36%, only LDL cholesterol in 14% and both VLDL and LDL cholesterol in 50% of cases. The low HDL cholesterol values in comparison to controls were related to higher VLDL triglyceride values in MI patients, since HDL cholesterol fell significantly with increasing VLDL triglyceride levels. When HDL cholesterol was related to similar VLDL triglyceride levels, there were no major differences between controls and MI.
Asunto(s)
Lipoproteínas/sangre , 1-Propanol , Autoanálisis , Centrifugación por Gradiente de Densidad , Colesterol/sangre , Electroforesis , Humanos , Masculino , Infarto del Miocardio/metabolismo , Obesidad , Triglicéridos/sangreRESUMEN
Monoclonal antibodies that interact with the decay accelerating factor (DAF, CD55), the lymphocyte homing receptor (CD44) or the intercellular adhesion molecule I (ICAM- 1) were found to inhibit the replication of different strains of Coxsackievirus serotype B4 (CBV-4) to various extent. By adding antibodies to CD55 the replication of two (V345 and VD2921) of seven strains in HeLa cells, three (V89-4557, VD2921 and T318) of seven in A549-10C cells and one (VD2921) of five strains in RD cells was blocked totally. Consequently, the replication of one strain (VD2921) was blocked in all cells indicating that this strain uses CD55 as a receptor or as a co-receptor on all cell lines and is unable to use another cell surface protein. The binding of this strain to the cell surface was inhibited by the antibodies to CD55. None of the CBV-4 strains was blocked totally by adding antibodies to CD44 to HeLa and A549-10C cells, whereas in RD cells the replication of one (T318) of the CBV-4 strains was blocked totally. The antibodies to ICAM-1 did not inhibit totally the replication of any strain in HeLa and RD cells, but it blocked totally the replication of one strain (CBV-4-E) in A549-10C cells. In HeLa and A549-10C cells the degree of replication correlated highly with the degree of cytopathic effect (CPE). In RD cells, four of the strains replicated without CPE. The adding of antibodies to the integrin alpha(v)beta(3) led to slightly enhanced replication of three of the CBV-4 strains in all cell lines. It is concluded that the receptor usage by different strains of CBV-4 varies not only within the same cells but also between different cell lines.
Asunto(s)
Anticuerpos Monoclonales , Enterovirus Humano B/fisiología , Proteínas de la Membrana/fisiología , Replicación Viral , Animales , Antígenos CD55/inmunología , Antígenos CD55/fisiología , Células CHO , Línea Celular , Cricetinae , Células HeLa , Humanos , Receptores de Hialuranos/inmunología , Receptores de Hialuranos/fisiología , Molécula 1 de Adhesión Intercelular/inmunología , Molécula 1 de Adhesión Intercelular/fisiología , Proteínas de la Membrana/inmunología , Receptores Virales/metabolismoRESUMEN
The effects of partial D2 dopamine (DA) receptor agonists on the behavioural activation produced by 1.5 and 8.0 mg/kg d-amphetamine were compared with the changes produced by the classical DA antagonist haloperidol. Alterations in behaviour were assessed in standard activity monitoring cages by direct observation of the rats using a rapid time sampling procedure. Haloperidol blocked d-amphetamine (1.5 mg/kg)-induced increases in photocell counts, ambulation, rearing and sniffing up, and after the highest dose of the DA antagonist the animals were mainly inactive. The partial D2 DA agonist SDZ 208-911 was equipotent to haloperidol in blocking the increase in photocell counts and rearing produced by d-amphetamine. However, even high doses of the drug did not reduce the incidence of sniffing or induce inactivity, but qualitative changes in the form of sniffing did occur. Although considerably less potent, preclamol exerted similar effects to SDZ 208-911. The profiles of SDZ 208-912 and terguride were intermediary to those of SDZ 208-911 and haloperidol. All compounds blocked the repetitive sniffing down produced by 8.0 mg/kg d-amphetamine. After a low dose of haloperidol, these stereotyped behaviours were replaced by a behavioural syndrome similar to that observed with low dose d-amphetamine, but inactivity was observed following a further small increase in antagonist dose. The blockade of stereotypy by SDZ 208-911, preclamol and terguride was accompanied only by the low dose d-amphetamine behavioural syndrome; no inhibition of sniffing or induction of inactivity occurred. SDZ 208-912 exhibited a profile with features very similar to that noted with haloperidol. These findings suggest that partial D2 agonists exert similar, but not identical, behavioural effects to classical DA antagonists when dopaminergic function in increased by d-amphetamine. The differences in behavioural profile are discussed in relation to variations in the intrinsic efficacy of the dopaminergic compounds and to differences in the response capability of D2 receptor populations underlying the different behaviours produced by d-amphetamine.
Asunto(s)
Dextroanfetamina/antagonistas & inhibidores , Actividad Motora/efectos de los fármacos , Receptores Dopaminérgicos/efectos de los fármacos , Conducta Estereotipada/efectos de los fármacos , Animales , Dextroanfetamina/farmacología , Dopaminérgicos/farmacología , Relación Dosis-Respuesta a Droga , Ergolinas/farmacología , Lisurida/análogos & derivados , Lisurida/farmacología , Piperidinas/farmacología , Ratas , Ratas Endogámicas , Receptores de Dopamina D2RESUMEN
Pentagastrin stimulates the release of calcitonin from normal C-cells in the human thyroid. In the present investigation the effect of cimetidine on the liberation of calcitonin in response to intraarterial pentagastrin (0.6 micrograms . kg-1) was studied in 14 normocalcaemic patients undergoing surgery for thyroid adenomas. Cimetidine was administered as a bolus injection of 200 mg followed by an intravenous infusion of 1.5 mg . kg-1 . h-1. In seven patients not given cimetidine, mean calcitonin concentration in the thyroid vein rose from 419 +/- 58 to 2787 +/- 645 pM in response to pentagastrin. In seven patients given cimetidine, mean calcitonin concentration only increased from 107 +/- 33 to 166 +/- 51 pM after pentagastrin. The difference between the two groups was statistically significant both during basal conditions (P less than 0.001) and in response to pentagastrin (P less than 0.01). The results suggest that pentagastrin affects normal C-cells via release of histamine and that cimetidine markedly interferes with this mechanism.
Asunto(s)
Calcitonina/sangre , Cimetidina/farmacología , Guanidinas/farmacología , Pentagastrina , Adulto , Anciano , Calcio/sangre , Femenino , Humanos , Persona de Mediana Edad , Glándula Tiroides/irrigación sanguínea , Glándula Tiroides/efectos de los fármacos , VenasRESUMEN
Francisella tularensis is used as a model organism in studies of mechanisms behind the induction of a protective T-cell response in the mammalian host. Protective immunity is associated with a CD4 and CD8 T-cell response towards a mosaic of proteins of F. tularensis and due to HLA restriction, each individual selects her own mosaic. No single protein has so far been shown to be immunodominant. Only live F. tularensis affords effective host protection. Subcellular antigen preparations induce only a marginal protective response even when combined with potent adjuvants such as immunostimulating complexes (ISCOMs). In mice, intradermal injection of live F. tularensis but not of killed bacteria results in an early cytokine expression in the infected liver, including interleukin-12, tumor necrosis factor-alpha, and interferon-gamma. This cytokine response seems to be a prerequisite for effective priming of T cells to an array of proteins of F. tularensis to occur.
Asunto(s)
Citoplasma/microbiología , Francisella tularensis/inmunología , Adyuvantes Inmunológicos/química , Animales , Vacunas Bacterianas/inmunología , Humanos , Ratones , Linfocitos T/inmunología , Tularemia/prevención & controlRESUMEN
An apparatus for extraction of solid matrices has been constructed which utilizes a microwave technique for heating in a dynamic mode. During the extraction, fresh solvent is continuously pumped through the extraction cell, which is maintained at a slight overpressure in order to keep the solvent in a liquid state. The extraction efficiency, which can be easily monitored, has been investigated in a factorial design and validated for polycyclic aromatic hydrocarbons in a reference sediment sample (EC-1). Important parameters were found to be temperature and duration of extraction. Flow-rate had no significant first-order effect on the recovery, but interaction effects with flow-rate were found to be significant. The dynamic microwave-assisted extraction apparatus was demonstrated to yield recoveries equivalent to Soxhlet extraction, but in a much shorter time. Each extraction of EC-1 typically takes 40 min.
Asunto(s)
Microondas , Cromatografía Líquida de Alta Presión , Espectrometría de FluorescenciaRESUMEN
Weekly dose Adriamycin was given prospectively as first line chemotherapy in a phase II study including 76 patients with evaluable advanced breast cancer. The response rate (CR+PR) was 24 percent (18/76) and a further 41 per cent (31/76) of the patients achieved stable disease (NC). Mean time to progression for responders was 17 months and for those with stabilized disease 10 months. Mean time to progression for all patients was 8.8 months and overall mean survival time 16 months (2-55+). Side effects were well tolerable; myelosuppression was registered in 27 percent and alopecia requiring a wig in 24 percent. In three patients cardiotoxicity was registered after 1,190 mg, 1,480 mg and 1,780 mg respectively. This low dose regimen seems effective and well comparable regarding time to progression with multidrug regimens, including doxorubicin.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/uso terapéutico , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/patología , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Esquema de Medicación , Femenino , Humanos , Menopausia , Persona de Mediana Edad , Metástasis de la Neoplasia , Estudios Prospectivos , Receptores de Estrógenos/análisis , Receptores de Progesterona/análisisRESUMEN
Thirty-five (34 evaluable) consecutive postmenopausal women with estrogen receptor positive (greater than or equal to 10 fmol/mg) or unknown advanced breast cancer were treated with high dose toremifene in a phase II study. All patients had progressed during prior adjuvant or palliativ antiestrogen treatment. The dose of toremifene was 240 mg per day. No complete or partial responders were registered. Nine patients (26%) were considered to have stable disease (NC). The time to progression for these patients was 5-27+ months with a mean time of twelve months and median time of eight months. Two patients are still on treatment after twelve and 24 months respectively. There seems to be a relationship with receptor value; however, there are two few patients for a safe statistical analysis. The side effects were insignificant. The conclusion is that the efficiency of toremifene as second line hormonal treatment is restricted, although it may be one additional choice.
Asunto(s)
Antineoplásicos/toxicidad , Neoplasias de la Mama/tratamiento farmacológico , Tamoxifeno/análogos & derivados , Tamoxifeno/uso terapéutico , Biomarcadores de Tumor/análisis , Evaluación de Medicamentos , Femenino , Humanos , Menopausia , Persona de Mediana Edad , Metástasis de la Neoplasia , Receptores de Estrógenos/análisis , Tamoxifeno/toxicidad , ToremifenoRESUMEN
We determined serum apolipoprotein A I and A II concentrations and triglyceride and cholesterol concentrations in serum lipoprotein density classes in 28 male patients with severe ischaemic heart disease (IHD) and with angiographically verified coronary artery disease (CAD) and in age-matched controls. Both triglyceride and cholesterol concentrations in very low density lipoproteins and in low density lipoproteins were higher in IHD-patients than in the controls. The triglyceride but not the cholesterol concentration in serum was higher in IHD-patients than in the controls. The cholesterol in high density lipoproteins and the serum apolipoprotein A I concentration were lower in IHD-patients than in the controls. At least in part the higher triglyceride concentration in very low density lipoproteins could be attributed to a decreased removal of triglycerides from the blood since the fractional removal rate of an i.v. injected artificial triglyceride emulsion (Intralipid) was slower in IHD-patients than in the controls.