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M Castell

Publications and source records attributed to M Castell.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Effective renal plasma flow with I-131-hipuran: evaluation of a method with four extractions].

The aim of this work was to evaluate a method for the estimation of the effective renal plasma flow (ERPF) using sodium 131I-o-hippurate (OIH) by means the bicompartmental analysis of the radioactive concentration of 4 plasma samples, analyzing the error obtained respecting to the multi-sample method and comparing it with those obtained with other simplified methods. We calculated the ERPF from 62 patients using the multi-sample method as standard, the method based in a single sample at 44 minutes p.i., a method based in 2 samples from the first exponential, 4 methods based in 2 samples from the second exponential, one method based in 3 samples and 5 methods based in 4 samples (2 from the first exponential and 2 from the second exponential). Each simplified method was compared to the standard method and their absolute error (AE) and standard estimation error (SEE) were calculated. The method based in the 4 samples withdrawn at 4, 10, 30 and 60 minutes p.i. was the best of them with a correlation factor with the standard equal to 0.997, an EA that ranged from -63 ml/min to 49 ml/min (mean: -4 ml/min) and a SEE of 19.5 ml/min.

Body Fluid Compartments↗
PubMed1998

[Nonmetastatic accumulations in bone radionuclide scans in a patient with breast neoplasm].

A 51 year old woman with breast cancer four years ago was studied by bone scintigraphy. At the moment of the study she had bone pain. The bone scintigraphy showed uptake in humerus and femur and no more uptake in other zones of axial skeleton. Then, we made others radiological procedures (X-Ray and MRI) with the aim to make an accurate diagnosis. Then a diagnosis of benign bone tumours; enchondroma was made. It means something obvious but very interesting. In case of doubt we ever have to compare the bone scintigraphy with other diagnostic. examinations.

Bone Neoplasms↗
PubMed1996

Depletion of gamma/delta T cells does not prevent or ameliorate, but rather aggravates, rat adjuvant arthritis.

OBJECTIVE: To investigate the role of gamma/delta T cells in Mycobacterium tuberculosis-induced rat adjuvant arthritis. METHODS: Rats with adjuvant arthritis were injected with anti-T cell receptor gamma/delta (anti-TCRgamma/delta) monoclonal antibody V65 according to a preventive protocol, a pre-arthritis peak protocol, and a late therapeutic protocol. Arthritis severity and joint destruction were monitored, and depletion of target cells was analyzed by flow cytometry. RESULTS: Although all protocols led to successful depletion of TCRgamma/delta(bright) cells in peripheral blood and lymph nodes, none of the regimens influenced clinical parameters of adjuvant arthritis. If rats were treated before the clinical peak of adjuvant arthritis, however, joint destruction was significantly more severe than in vehicle-treated rats. CONCLUSION: Rat adjuvant arthritis is not promoted or perpetuated by gamma/delta T cells. Aggravation of joint destruction with pre-arthritis peak anti-gamma/delta treatment suggests a stage-dependent protective role of gamma/delta T cells in adjuvant arthritis.

Animals↗
PubMed1996

Treatment with an anti-CD4 monoclonal antibody strongly ameliorates established rat adjuvant arthritis.

Some experimental arthritic diseases can be prevented by treatment with anti-CD4 MoAbs. Trials with ongoing disease have not been successful so far. The aim of this study was to ascertain whether W3/25 could reverse adjuvant arthritis (AA), when beginning treatment on day 14, i.e. when the disease was established. Moreover, one group of animals treated with the anti-CD4 MoAb received OX8 MoAb at the same time, thus depleting CD8+ cells from circulation. During treatment with W3/25, a strong amelioration of inflammatory signals were observed, as assessed by means of paw volume increase and arthritic score. However, when treatment stopped, a rebound to arthritis signals occurred. The parallel depletion of CD8+ cells did not modify these effects, thus the combined treatment W3/25 + OX8 gave the same amelioration as treatment with W3/25 alone. These findings indicate that CD4+ cells play an important role in perpetuating rat AA. Moreover, CD8+ cells do not seem to have a regulatory role int he CD4+ cells responsible for the inflammatory response.

Animals↗
PubMed1996

Simultaneous administration of 99Tcm-HMPAO-labelled autologous leukocytes and 111In-labelled non-specific polyclonal human immunoglobulin G in bone and joint infections.

The aim of this study was to investigate the ability of 111In-labelled human polyclonal immunoglobulin G (111In-IgG) to localize bone and joint infections compared with 99Tcm-HMAPO-labelled leukocytes (99Tcm-WBC). Thirty-four patients routinely referred for investigation of bone and joint infections were studied. In all patients, a bone scan using 99Tcm-MDP was initially obtained. Subsequently, 99Tcm-WBC and 111In-IgG were simultaneously injected and images obtained at 30 min, 4 h and 24 h post-injection. Diagnostic accuracy was established by bacteriology of specimens obtained by needle aspiration and/or surgery, other imaging methods and clinical follow-up. The images were read by three experienced observers blinded to any other information; the clinical suspicion of infection and the diagnosis were established when two observers agreed. Infection was confirmed in 11 patients. The 99Tcm-WBC scans gave 8 true-positive, 5 false-positive, 18 true-negative and 3 false-negative results. With 111In-IgG, the figures were 7, 6, 17 and 4, respectively. The sensitivity, specificity and accuracy were 72.7%, 78.2% and 76.4% respectively for the labelled leukocytes and 63.6%, 73.9% and 70.6% respectively for 111In-IgG. There was greater agreement between the observers with 99Tcm-WBC than 111In-IgG. In this study, 111In-IgG was less sensitive and less specific than 99Tcm-WBC scintigraphy for the diagnosis of chronic infections, but these differences were not significant. Both tracers appear to be useful in the diagnosis of bone and joint infections. However, our results were less reliable for the diagnosis of an infected prosthesis.

Adult↗
PubMed1995

Comparison of four lymphocyte isolation methods applied to rodent T cell subpopulations and B cells.

The aim of this study was to establish the validity of four lymphocyte isolation methods. The effects of three different erythrocyte lysing methods commonly used in the analysis of human cells, namely, lysis by ammonium chloride (AC), Becton Dickinson lysis (BDL) and the Coulter Q-Prep (CQP) preparation system were established by flow cytometry on rat lymphocyte subsets. The results were compared with those obtained with a Ficoll-Isopaque (FI) density gradient procedure adapted for use with rat cells. Lymphocyte isolation by AC or FI gradient was performed before labelling the lymphocyte subpopulations, whereas the BDL and CQP methods were performed after staining the cells in whole blood. The FI gradient yielded the lowest CD5+, CD4+ and CD25+ cell percentages. On the other hand AC lysis produced higher percentages of T cells and lower percentages of B cells than the other methods studied. The percentages obtained after BDL or CQP methods for T lymphocyte subsets and B cells were found to be reproducible. The commercial methods (BDL and CQP) are faster but rather expensive, whereas AC lysis and FI gradient separations are cheap and particularly useful when there is a requirement to culture the cells.

Animals↗
PubMed1995

Administration of a nondepleting anti-CD4 monoclonal antibody (W3/25) prevents adjuvant arthritis, even upon rechallenge: parallel administration of a depleting anti-CD8 monoclonal antibody (OX8) does not modify the effect of W3/25.

The aim of this study was to determine the effects of the anti-CD4 monoclonal antibody (mAb) W3/25, found to be nondepleting, on the onset of rat adjuvant arthritis (AA), and, in addition, to ascertain whether depletion of CD8+ cells during the same period could interfere with those effects. Female Wistar rats in which AA had been induced were treated with W3/25 and/or OX8 (anti-rat CD8) mAb during the latency period of arthritis. W3/25 alone or in combination with OX8 prevented the inflammatory process of AA. When the protected groups were rechallenged with a second dose of Mycobacterium butyricum no arthritis was observed. Protected and nonprotected arthritic animals developed the same anti-mycobacteria antibody levels as the arthritic control group. This study indicates that a nondepleting anti-CD4 mAb can prevent AA, while CD8+ lymphocytes do not appear relevant for the development of AA and do not seem to have a regulatory role for CD4+ cells.

Animals↗
PubMed1995

Immunohistochemical changes in synovial tissue during the course of adjuvant arthritis.

OBJECTIVE: To study immunohistochemical changes occurring in knee synovial membranes of rats during the time course of adjuvant arthritis (AA). The effect of treatment with dexamethasone after establishment of arthritis was also studied. METHODS: AA was induced in Wistar rats by means of a single injection of a suspension of Mycobacterium butyricum. On Days 7, 14, 17, 21, 28 and 42 after induction, synovial membranes were obtained, frozen and sectioned on a cryostat. Tissue sections were tested by peroxidase-antiperoxidase method, using the following monoclonal antibodies: OX19 (CD5), W3/25 (CD4), OX8 (CD8), OX6 (Ia), OX33 (LCA) and OX39 (CD25). RESULTS: Knee synovial membranes obtained from arthritic rats on days of maximum inflammation showed few or no CD5+ cells, a higher proportion of CD8+ cells, and a higher number of CD4+ and Ia+ cells than healthy synovial tissues. CD25+ cells were observed from Day 7 postinduction and remained numerous throughout the study. CONCLUSION: Few T lymphocytes (CD5+) were found in arthritic synovial membrane, whereas an increase of cells expressing CD8, CD4, CD25, Ia, and LCA was found. These increases (except CD8) are not evident in dexamethasone treated rats.

Animals↗
PubMed1994

Effect of acetylsalicylic acid and dexamethasone on antibody production in adjuvant arthritis.

The production of antibodies to IgG and type II collagen occurs in a similar fashion in human rheumatoid arthritis and adjuvant arthritis. In this study, the effect of dexamethasone (DXT) and acetylsalicylic acid (ASA) on antibody synthesis was analysed. Daily treatment with DXT (0.3 mg/kg per day p.o.) or with ASA (200 mg/kg per day p.o.) from day 14 to day 56 after arthritis induction inhibited both the synthesis of antibodies to IgG and type II collagen and also the humoral immune response to the mycobacteria that induced the disease. The immunosuppressive response was similar for both drugs: DXT, which is known to suppress the immune response, and ASA, a classical anti-inflammatory agent.

Analysis of Variance↗
PubMed1994

Time course of antibodies against IgG and type II collagen in adjuvant arthritis. Role of mycobacteria administration in antibody production.

The aim of this study was to elucidate, during the time course of adjuvant arthritis, the existence of antibodies directed to IgG (rheumatoid factor-like) and antibodies against type II collagen. In a second study, we also studied the relation between antibody production, arthritic process and mycobacteria administration. We have demonstrated the presence of antibodies to IgG and type II collagen by means of ELISA techniques. This reactivity appeared on day 7 post-induction, decreased later, and increased progressively from day 21 until last day studied (day 56 post-induction). We have also quantified antibodies against a soluble fraction of Mycobacterium butyricum, the inductor of the disease. Anti-mycobacteria antibodies appeared during the first seven days after induction, but from day 14, when systemic inflammation began, their levels suddenly increased. There is a positive correlation between anti-mycobacteria antibody levels and articular swelling. Anti-IgG and anti-collagen antibody production was not directly linked to arthritic process since these antibodies were synthesized when M. butyricum was administered intraperitoneally, which does not induce arthritis. Anti-mycobacteria antibody concentration was higher when arthritis induction by mycobacterial was successful than when it was unsuccessful.

Animals↗
PubMed1994

Anti-type I collagen antibodies in advanced phases of adjuvant arthritis.

The aim of this study was to elucidate the existence of autoantibodies directed to type I collagen as a response to connective tissue alterations that occur in inflammatory diseases. We have demonstrated the presence of antibodies to type I collagen during the time course of adjuvant arthritis, by means of the ELISA technique. These autoantibodies reached the highest levels in advanced phases of the arthritic process from 8 to 10 weeks after mycobacteria administration. The hind-paw swelling and the anti-type I collagen antibodies remained for at least 18 weeks post-induction.

Animals↗
PubMed1994

Blood lymphocyte subsets in rats with adjuvant arthritis.

OBJECTIVES: To determine the phenotype of peripheral blood lymphocytes during the time-course of adjuvant arthritis (AA) to detect alterations that could be involved in the pathogenesis of the arthritic process. METHODS: Phenotype analysis was performed on days 7, 14, 21, 28, 42, 56 and 70 after arthritis induction using monoclonal antibodies to CD5, CD4 and CD8 subsets, and flow cytometry. The proportion of activated lymphocytes and lymphocytes was also assessed with monoclonal antibodies to IL-2R (CD25), to Ia antigen and by polyclonal antibodies to rat Ig. RESULTS: Adjuvant arthritis produced leukocytosis with neutrophilia. Rats with AA showed a marked increase in the number of both CD4+ and CD8+ cells. The ratio CD4/CD8 decreased because the rise in CD8+ cells was more pronounced than the increase in CD4+ cells. Changes in lymphocyte counts showed two well-defined periods: the first, from day 14 to day 28, during which the inflammation of the joints reached a maximum and changes in lymphocyte subsets were more pronounced, that is, there was a threefold increase in CD8+ lymphocytes over normal counts, and the second, from day 42 to day 70, in which modified parameters improved considerably but remained different from controls. CONCLUSION: Alterations were detected in the phenotype of peripheral blood lymphocytes in AA, which provides an additional marker of disease activity.

Animals↗
PubMed1994

Anticytoskeletal autoantibody development in adjuvant arthritis.

OBJECTIVE: Because the presence of autoantibodies against cell components is a common feature of most autoimmune diseases and some of these autoantibodies have been detected in sera of patients with rheumatic diseases such as rheumatoid arthritis (RA), we studied the presence of autoantibodies to cell components in an experimental model of chronic inflammation in rats, adjuvant arthritis (AA), to determine possible similarities between AA and human RA. METHODS: Sera from arthritic rats were initially tested by indirect immunofluorescence using rat liver sections as a substrate. Afterwards, arthritis sera were further studied in cultures of human skin fibroblasts and the HEp-2 cell line, with or without colchicine treatment. RESULTS: Results using liver as substrate showed that 31% of the arthritic rats showed a cytoskeleton staining pattern throughout the cytoplasm, with higher intensity of staining along the surface membranes, particularly in pericanalicular regions. This staining was suggestive of intermediate filament autoantibodies. When sera were analyzed on cultured cells, the results showed that the pattern is identical to the arrangement described for intermediate filaments and different from those seen with antiactin antibodies. Colchicine pretreatments ruled out antitubulin activity. Further analysis by immunoblotting revealed that autoantibodies did not recognize intermediate filament proteins when these were denatured in the electrophoretic process. CONCLUSION: The development of autoantibodies to intermediate filament proteins, both cytokeratin and vimentin, has been demonstrated in sera from rats with AA, in a similar manner to that described in human RA.

Animals↗
PubMed1993

Blood B, T, CD4+ and CD8+ lymphocytes in female Wistar rats.

We have established reference values of peripheral blood lymphocyte subsets in healthy female Wistar rats under highly standardized conditions. Using monoclonal antibodies and flow cytometry, T lymphocytes (OX19+), B lymphocytes (OX6+ and anti-Ig+), T-helper/inducer (W3/25+), and T-suppressor/cytotoxic subsets (OX8+) were determined, from week 11 to week 21 after birth. The mean percentages of T and B lymphocytes with respect to total lymphocytes were 78.5% and 18%, respectively; the mean percentages of T-helper/inducer and T-suppressor/cytotoxic cells in relation to T lymphocytes were 59% and 25%, respectively (n = 48). No difference in total leukocyte count, differential leukocyte analysis, or lymphocyte subsets was observed during the 10 weeks the rats were studied under standard housing conditions. Therefore, the period considered seems the most appropriate in which to carry out experiments that could involve lymphocyte subset disturbances.

Animals↗
PubMed1992

Adjuvant arthritis pretreatment with type II collagen and Mycobacterium butyricum.

A treatment previous to adjuvant arthritis induction has been performed with type II collagen (CII) or Mycobacterium butyricum (Mb), which is the inducer of the pathology. Pretreatment was administered in two different ways: a) subcutaneously or intradermally 14 days before arthritis induction, and b) intravenously 3 days before induction. In order to relate the change in inflammation to the corresponding antigen immune response, serum antibodies and delayed type hypersensitivity (DTH) against CII or Mb were studied. Pretreatment with s.c. CII 14 days before induction produced slight protection against arthritis and significantly delayed its onset; systemic inflammation showed good positive correlation with anti-CII antibodies. The CII administered i.v. 3 days before arthritic challenge did not significantly modify the inflammatory process. The use of i.d. subarthritogenic doses of Mb 14 days before induction protected a high percentage of the animals from the posterior arthritic challenge; this protection was accompanied by high anti-Mb antibody titers and DTH reaction. When Mb was given i.v. 3 days before induction, a partial protection of inflammation was observed; arthritis was milder and its onset was delayed. These changes were accompanied by reduced humoral and cellular response to Mb.

Animals↗
PubMed1990

Urinary N-acetyl-beta-D-glucosaminidase as a marker of renal injury in adjuvant arthritis.

In the present study we have determined if renal damage occurs with adjuvant arthritis (AA). As a sensitive indicator of renal injury in tubular cells, urinary N-acetyl-beta-D-glucosaminidase (NAG) was measured at predetermined times after arthritis induction. Urinary protein, sodium and potassium excretion were also evaluated. NAG levels in arthritic animals were higher than those in healthy ones from day 12 after induction and the levels remained high during the study period. A significant positive correlation was noted between urinary NAG excretion and disease severity reflected by hind paw edema. Protein excretion also increased in arthritic animals but there was no correlation between urinary protein, NAG levels, and degree of inflammation. Changes in urine sodium and potassium levels did not reach statistical significance. Thus, we can conclude that some renal damage occurred in this experimental model of chronic inflammation.

Acetylglucosaminidase↗
PubMed1987

Serum sulfhydryl group levels in experimental chronic inflammation.

Serum sulfhydryl group concentration and protein fraction were determined in adjuvant arthritic rats, during six weeks. Significantly reduced sulfhydryl levels were found in arthritic rats from day 3 and these values remained decreased throughout the study period. Good correlation exists between serum sulfhydryl alterations and degree of inflammation measured as hind paw swelling, as well as between the former and changes in serum protein fractions.

Animals↗