Purification, characterization, and immunolocalization of a thioredoxin reductase from adult Fasciola hepatica.

Thioredoxin reductase (TrxR), an enzyme belonging to the flavoprotein family of pyridine nucleotide-disulfide oxidoreductases, was isolated from the deoxycholate-soluble extract of the common liver fluke, Fasciola hepatica. Purification to homogeneity of the 60-kDa enzyme from the adult worm was achieved by a combination of ammonium sulfate fractionation, anion exchange, and affinity chromatography on 2',5'-adenosine diphosphate-Sepharose. Using the 5,5'-dithiobis(2-nitrobenzoic acid) assay, the purified TrxR showed a specific activity of 7,117 U min(-1) mg(-1). The enzyme activity was completely inhibited by the presence of the gold compound aurothioglucose (IC50 = 120 nm), indicating that F. hepatica TrxR is a selenoenzyme. Also, the enzyme was capable of reducing disulfide bonds in insulin and was activated by the presence of the reduced form of flavin adenine dinucleotide, properties shared with mammalian TrxRs. Furthermore, the isolated enzyme showed very low glutaredoxin (Grx) activity (0.47 U mg(-1)), but no glutathione reductase activity was detected. Affinity-purified IgGs (20 microg ml(-1)) from the antisera produced against the purified TrxR inhibited its activity about 80% with respect to the control. The enzyme was immunolocalized in cells located within the parenchyma and in the testes, but it was not found in the tegument of the adult fluke.

Hepatic outer-ring deiodinase in a Mexican endemic lizard (Sceloporus grammicus).

The kinetic characterization of the outer-ring deiodination pathway using rT(3) (rT(3)-ORD) in male, female, and pregnant female livers of an endemic lizard, Sceloporus grammicus, is reported. The ORD pathway does not have the characteristics of deiodinase type II; it is exclusively carried out by deiodinase type I (DI). DI enzymatic activity in lizard liver contains one of the highest activities reported in vertebrates. This activity is sexually dimorphic, with males presenting the highest activity during the reproductive season. The properties of this enzyme correspond to those described in mammals, such as specificity for rT(3), susceptibility to inhibition by 6-n-propyl-2-thiouracil and gold-thioglucose, cofactor requirement, and kinetic pattern. Unlike other vertebrates, the lizard DI exhibits conspicuous stability in the thermal range of 15 to 42 degrees C and in the pH range of 5.0 to 9.0. Male true kinetic constants exhibit a direct correlation with temperature. This is in agreement with short-term adaptation to microenvironmental changes and the feasible expression of enzymatic forms/variants which, together, endow this lizard species with a greater adaptation to natural daily ambient thermal fluctuations.

The effect of adipose cell size on the measurement of GLUT 4 in white adipose tissue of obese mice

Glucose transporter (GLUT 4) was assessed in subcellular membrane fractions of white adipose tissue (WAT) from obese insulin-resistant aurothioglucose (AuTG)- or monosodium glutamate (MSG)-treated mice. Obesitywas demonstrable by increased body weight and/ or Lee index, as well as by the heavier WAT and brown adipose tissue in relation to similar weights of gastrocnemius and heart. In vivo insulin-resistance in obese animals was suggested by moderate hyperglycemia and severe hyperinsulinemia. Morphological analyses of adipose cells showed a > 10-fold increase in cell volume of obese mice. Subcellular fractionation indicated a reduced (P<0.01) protein membrane content in the fat-free extract (FFE) from obese mice. However, the specific activity of 5'nucleotidase, a plasma membrane (PM) marker, in EFE and PM did not differ among groups. In addition, the total PM enzyme activity per unit of cell surface area was also unchanged. The GLUT 4 content, assessed by Western blotting and expressed per µg membrane protein, was reduced by ~50 percent (P<0.01) in all membrane fractions from obese animals. However, the total FFE GLUT 4 content per cell was increased...

Reduced content and preserved translocation of glucose transporter (GLUT 4) in white adipose tissue of obese mice.

We investigated glucose transporters (GLUT 1 and GLUT 4) in subcellular membrane fractions of white adipose tissue (WAT) of insulin-resistant obese aurothioglucose (AuTG)- or monosodium glutamate (MSG)-treated mice. In vivo insulin stimulation (0.75 U/kg, EV) promoted, 10 min later, no significant change on glycemia of both AuTG and MSG obese mice, but control mice showed a decrease of 30% (p < 0.001). Basal GLUT 4 content in WAT of obese mice was reduced by 40% (p < 0.001) when compared to that of nonobese mice. Insulin-stimulated GLUT 4 content was significantly (p < 0.01) higher in plasma membrane fraction and lower in microsomal fraction when compared to respective basal values, in all groups. Although the absolute values of GLUT 4 were lower in membrane fractions of obese mice, the relative changes stimulated by insulin were similar among the groups. No effect of obesity or insulin stimulation was observed upon GLUT 1 content. We conclude that WAT of insulin-resistant obese AuTG- and MSG-treated mice has a decreased GLUT 4, but not GLUT 1, content, and the in vivo insulin-stimulated GLUT 4 translocation is preserved.

Goldthioglucose causes brain norepinephrine and serotonin depletion correlated with increased body weight.

Goldthioglucose (GTG) injected i.p. in mice is known to cause hyperphagia and obesity which is related to ventromedial hypothalamic damage and norepinephrine (NE) depletion in females. In the present experiment 6 doses of GTG were tested in males. After 160 days the monoamine content of whole brain was measured. Norepinephrine (NE) and serotonin (SER) were depleted without changes in dopamine content. Brain NE and SER were both negatively correlated with body weight. These experiments extend earlier studies by suggesting that GTG obesity in mice may be caused by NE depletion in males as well as females and by suggesting that the obesity is also a function of serotonin depletion.

Terapêutica coadjuvante no tratamento do pênfigo foliáceo sul-americano com auranofina: estudo duplo-cego / Coadjuvant therapy with auranofin in the treatment of the South American pemphigus foliaceus: a double blind study

Os autores descrevem suas experiência do uso de auranofina como tratamento coadjuvante na terapêutica do pênfigo foliáceo sul-americano em estudo duplo-cego e chamam a atençäo para os efeitos produzidos pela auranofina nos parâmetros imunológicos da doença. Afirmam que a droga tem sua utilidade no tratamento de pacientes portadores de pênfigo, no entanto sugerem o prosseguimento da pesquisa

Monocyte bone degradation: in vitro analysis of monocyte activity in patients with juvenile rheumatoid arthritis.

We examined the ability of the mononuclear phagocyte in vitro to degrade 45Ca-labeled bone particles to determine whether this assay allowed us to monitor disease activity in patients with juvenile rheumatoid arthritis. The monocytes from patients with juvenile rheumatoid arthritis receiving no anti-erosive therapy (n = 10) degraded significantly more bone than did cells obtained from normal controls (n = 10, P less than 0.001) or patients with juvenile rheumatoid arthritis receiving either gold thioglucose (n = 4, P less than 0.001) or D-penicillamine (n = 6, P less than 0.005). In two patients monitored for either 8 or 11 months, results of monocyte assays were found to parallel the clinical course. We conclude that in vitro monocyte bone degradation assays may provide a means of assessing joint activity in patients with juvenile rheumatoid arthritis. Further, this study and others indicate that mononuclear phagocytes are capable of causing erosive changes.

Valoracion clinica - eficacia y tolerancia - de un nuevo compuesto quimico (auranofin) por via oral en el tratamiento de la artritis reumatoide. / Clinical evaluation-efficacy and tolerance - of a new chemical compound (auranofin) by oral administration in the treatment of rheumatoid arthritis

El presente estudio resume la experiencia obtenida con el empleo de crisoterapia oral - auranofin - en 22 pacientes afectados por artritis reumatoide. El tratamiento vario entre 6 y 36 meses.Se administraron 6 mg de auranofin diariamente, en una sola toma o repartida en dos. Los resultados fueron alentadores: 17 enfermos terminaron el estudio, en 4 hubo remision, en otros 4 resultados catalogados como muy buenos, buenos en 4 mas, ligeros en 3 y malos o desfavorables en 2. Se suspendio el tratamiento en 4 enfermos; 3 de ellos por efectos indeseables (1 neutropenia, 1 sensibilidad al oro, 1 agravacion de la AR) en el cuarto caso por embarazo. Hubo una desercion

Auranofin in the treatment of juvenile rheumatoid arthritis.

Auranofin (triethylphosphine gold) was administered to 21 patients with juvenile rheumatoid arthritis during an open-ended, open-label, noncontrolled trial designed to establish safety and preliminary efficacy. Initial dosage was 0.1 mg/kg/day; incremental increases to 0.2 mg/kg/day were allowed. Aspirin (80 mg/kg/day), tolmetin (20 to 40 mg/kg/day), and naproxen (400 to 600 mg/m2/day) were allowed as rapidly acting anti-inflammatory agents. All patients attained measurable plasma concentrations of gold during the study. Clinically significant improvement (greater than 25%) occurred in more than half the patients with regard to the number and severity of joints with swelling, pain on motion, and tenderness. The number of joints with active arthritis decreased by at least 25% in nine of the 19 patients. Group mean changes between the initial and final visit indicated improvement in all articular disease indices measured. Eleven of 16 patients with an elevated erythrocyte sedimentation rate showed decreases of at least 25%. The group given the higher dosage had a greater proportion of responders with decreases in erythrocyte sedimentation rate. Four of six patients whose sera contained rheumatoid factor showed decreases in its titer. Discontinuation of auranofin was necessary in two patients because of headaches and because of hematuria and anemia associated with a severe flare of polyarticular disease, respectively. The results from this trial are sufficiently encouraging to merit a double-blind trial of auranofin in children with juvenile rheumatoid arthritis.