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Biomedical subjects

K Pirich

Publications and source records attributed to K Pirich.

17 recordsLinked to original sources
PubMed1991

The immunoregulatory influence of transforming growth factor beta in thyroid autoimmunity: TGF beta inhibits autoreactivity in Graves' disease.

The immunoregulatory influence of transforming growth factor beta (TGF beta) was studied in patients with Graves' disease and in normal controls. Special attention was given to determine how TGF beta affects the interaction between thyroid epithelial cells and T lymphocytes. Human recombinant TGF beta 1 (rTGF beta 1) was immunosuppressive in patients with Graves' disease and in controls. In both groups it inhibited the proliferation of peripheral blood mononuclear cells and of peripheral and thyroid derived T cell lines and clones in response to non-specific stimuli. It also decreased the number of serine esterases expressing cytotoxic T cells and suppressed the recognition of thyroid epithelial cells by thyroid autoantigen specific T cell clones. Inhibition of autoantigen recognition was not only observed when rTGF beta 1 was added to the thyroid epithelial cell/lymphocyte co-culture, but was also found when thyroid epithelial cells were preincubated with rTGF beta 1, which was then removed before the initiation of co-culture. This was probably as a result of a decrease in the antigenicity of the target cells, as rTGF beta 1 also suppressed thyroid peroxidase as well as HLA class II autoantigen expression, in cultured thyroid epithelial cells. These results demonstrate that TGF beta may exert a variety of down-regulatory influences in Graves' disease. It may be of importance for the suppression of autoaggression in persons predisposed to autoimmunity; may be quantitatively overrun by immunostimulatory influences in the acute phase of the disease; and may be important for the induction of remission in patients with Graves' disease.

Adolescent↗
PubMed1990

CD4+ T-cell clones from autoimmune thyroid tissue cannot be classified according to their lymphokine production.

In order to define whether CD4+ T cells from autoimmune and non-autoimmune thyroid tissue could be classified according to their mediator production, lymphokine production was studied in 63 thyroid-derived CD4+ T-cell clones from four patients with Graves' disease, one with Hashimoto's thyroiditis, and one with non-toxic goitre (9-12 clones per patient). The production of interleukin 2 (IL-2), gamma interferon (IFN-gamma), tumour necrosis factor alpha (TNF-alpha), lymphotoxin (LT), interleukin 6 (IL-6) and transforming growth factor beta (TGF-beta) was assessed at the mRNA level by slot-blot analysis in unstimulated clones as well as after activation with monoclonal anti-CD3 (OKT3) and IL-2. No lymphokine production was found in unstimulated clones, whereas 56% of the clones produced all six lymphokines simultaneously after stimulation. In the remaining 44% usually not more than one lymphokine was missing from the complete panel. Lymphokine mRNA concentrations varied between different clones and different patients, but, in this small sample, not between the diseases from which the clones were originated. There was a significant correlation between IL-6, LT, and IL-2 mRNA levels and T-cell helper function, which was estimated by the stimulation of thyroid microsomal autoantibody production using autologous peripheral B cells. TGF-beta and IFN-gamma mRNA expression was unrelated to T-cell help. The results demonstrate that intrathyroid T cells from autoimmune and non-autoimmune thyroid disorders cannot be classified according to their lymphokine production, unlike some results with in vitro-induced mouse T-cell clones, where two populations, Th1 and Th2, have been described. Single T cells are capable of producing a whole panel of lymphokines and thus are capable of triggering a multitude of different processes.

CD4-Positive T-Lymphocytes↗
PubMed1989

Transforming growth factor beta regulates thyroid growth. Role in the pathogenesis of nontoxic goiter.

The production and growth regulatory activity of transforming growth factor beta were studied in human thyroid tissue. As estimated by its mRNA expression in fresh tissue samples, transforming growth factor beta was produced in normal and in diseased thyroid glands. Transforming growth factor beta mRNA was mainly produced by thyroid follicular cells and in lesser quantities by thyroid infiltrating mononuclear cells. The concentrations of transforming growth factor beta mRNA were lower in iodine-deficient nontoxic goiter than in Graves' disease and normal thyroid tissue. Transforming growth factor beta protein secretion by cultured thyroid follicular cells was also low in nontoxic goiter, but could be increased by addition of sodium iodide (10 microM) to the culture medium. Recombinant transforming growth factor beta did not affect basal tritiated thymidine incorporation in cultured thyroid follicular cells, but inhibited, at a concentration of 10 ng/ml, the growth stimulatory influence of insulin-like growth factor I, epidermal growth factor, transforming growth factor alpha, TSH, and partly that of normal human serum on cultured thyroid follicular cells. This inhibition was greater in Graves' disease than in nontoxic goiter. These results suggest that transforming growth factor beta may act as an autocrine growth inhibitor on thyroid follicular cells. Decreased transforming growth factor beta production and decreased responsiveness to transforming growth factor beta may be cofactors in the pathogenesis of iodine-deficient nontoxic goiter.

Adult↗
PubMed1989

Tumour necrosis factor synergises with gamma interferon on the induction of mRNA for DR alpha chain on thyrocytes from Graves' disease and non toxic goitre.

In both thyroid autoimmune diseases Graves' and Hashimoto's thyroiditis, the epithelial thyroid follicular cells (TFC) have been shown to express HLA class II molecules, and can restimulate autoreactive T cells cloned from the diseased tissue. This aberrant class II expression is important in the mechanism of perpetuation of the disease process, therefore we have compared the effect of interferon gamma (IFN gamma) and tumour necrosis factor (TNF alpha) on the HLA-DR alpha mRNA expression of thyroid follicular cells derived from Graves' disease (GD) and a non autoimmune disease, non toxic goitre (NTG). Our results indicate that TNF alpha synergises with IFN gamma in the induction of HLA class II mRNA. There was no consistent difference in DR alpha mRNA expression between the GD and NTG thyroid follicular cell preparations in response to induction by a combination of these lymphokines at various concentrations. Our data suggest that the differences in the level of expression of class II molecules observed in vivo in Graves' disease and non toxic goitre, which is much higher in the former, is probably due to local release of lymphokines by infiltrating T lymphocytes, although other factors may be involved.

Drug Synergism↗
PubMed1989

Analysis of intrathyroidal cytokine production in thyroid autoimmune disease: thyroid follicular cells produce interleukin-1 alpha and interleukin-6.

Cytokine production was studied in thyroid tissue from patients with Graves' disease, Hashimoto's thyroiditis and non-toxic goitre. The expression of interferon gamma, tumour necrosis factor alpha and beta, interleukin-1 alpha and beta, interleukin-6 and platelet-derived growth factor A chain was assessed by slot-blot analysis of the respective mRNA in freshly isolated tissue samples. All seven cytokines were detected in patients of all groups. Although the respective mRNA levels were, in general, higher in thyroid autoimmune disorders, this appeared to relate to the degree of the lymphocytic infiltration of the thyroid gland at the time of surgery. Purified thyroid follicular cells expressed high levels of interleukin-1 alpha and interleukin-6 mRNA and when established in primary culture, purified thyroid follicular cells from Graves' disease as well as non-toxic goitre produced interleukin-1 alpha and interleukin-6 bioactivity spontaneously. In the case of interleukin-1 this could be further augmented by addition of lipopolysaccharide to the thyroid follicular cell cultures. These results demonstrate that the lymphocytic infiltrate found in autoimmune and non-autoimmune thyroid disorders is associated with cytokine production. Additionally we have shown that intrathyroidal cytokine production is not restricted to thyroid-infiltrating mononuclear cells, but may also involve thyroid follicular cells both in vivo and in vitro. The cytokines produced by thyroid follicular cells may have an important role in stimulating autoantigen specific T cells in vivo as both interleukin-1 and interleukin-6 facilitate T cell activation.

Adult↗
PubMed1988

[Magnetic resonance tomography as a localization method in hyperparathyroidism].

Magnetic Resonance Imaging (MRT) was performed in 36 consecutive patients with hyperparathyroidism. MR tomograms of 31 patients were evaluated and compared with the results of operation and histology (n = 29). In the remaining 5 patients MR examination was not completed, due to claustrophobia or motion artefacts. MR examinations were performed in 2 superconductive magnets (0.5 and 1.5 Tesla). A surface coil with following spinecho sequences was used: SE: TR/TE: 550-700/15-30; 2000/22-100. All patients were subjected to additional sonography. Out of 28 parathyroid adenomas 25 were identified on MR tomograms (sensitivity: 73%, specificity: 90%). However, only 2 out of 6 hyperplastic parathyroid glands were localized on MR tomograms. Lesions missed on MR tomograms measured 15 mm and less in diameter. It is characteristic that parathyroid adenomas showed isointense MR signal to the thyroid (SE 550/30 and hyperintense MR signal to fat (SE 2000/100). Different signal intensities of the adenomas were observed in 25% of the cases. MR imaging is a valuable diagnostic method for preoperative localisation of parathyroid adenomas. We think that MR imaging should be performed when sonography and subtraction scintigraphy are not able to identify a suspected adenoma in the same location.

Adenoma↗
PubMed1988

24-hour serum concentration profile of cortisol in patients with Cushing's disease.

To evaluate whether or not patients with Cushing's disease can be differentiated from those with obesity by the determination of 24-hour integrated serum concentrations of cortisol we studied healthy, nonobese males (n = 5), as well as patients with marked obesity (n = 5) and with Cushing's disease (n = 7) in whom diagnosis was established biochemically and subsequently confirmed by surgery. Serum cortisol concentrations in samples collected continuously by a portable blood withdrawal pump during 24 hours (08:00-08:00h) were 6.6 +/- 1.7 micrograms/dl and 8.4 +/- 1.5 micrograms/dl in nonobese and obese individuals, respectively. Patients with Cushing's disease presented a mean cortisol concentration of 21.4 +/- 6.4 micrograms/dl (p vs normal: less than 0.005; vs obesity: less than 0.005). Collecting consecutive samples in 4-h periods the decline of serum cortisol from peak to nadir values was 73 +/- 10% and 57 +/- 23% in normal males and obese subjects, respectively, while a decline of only 22 +/- 8% was seen in patients with Cushing's disease. Three of the patients with Cushing's disease exhibited a circadian rhythm of cortisol albeit on an elevated level. These results may reflect variable stages of autonomy in pituitary ACTH-production and hence a possible criteria for differentation of hypothalamic and pituitary forms of Cushing's disease. In regard to differential diagnosis between Cushing's disease and obesity the 24-hour cortisol profile obtained by multiple sampling did not provide additional information to that obtained by a single sample pooled for 24 hours, which was diagnostic in each case.

Adrenocorticotropic Hormone↗
PubMed1988

Pathogenetic relevance of HLA class II expressing thyroid follicular cells in nontoxic Goiter and in Graves' disease.

HLA class II expressing thyroid follicular cells are found not only in classical thyroid autoimmune diseases, such as Graves' disease, but also in presumably nonautoimmune thyroid disorders such as nontoxic goiter. In this study the immunostimulatory function of the HLA class II expressing thyroid follicular cells derived from patients with nontoxic goiter and with Graves' disease was compared by assessing their capacity to stimulate allogeneic and autologous peripheral blood mononuclear cells, as well as cultured intrathyriodal T lymphocytes. Proliferation of allogeneic peripheral blood mononuclear cells was stimulated by thyroid follicular cells from both nontoxic goiter and Graves' disease thyroids, thus demonstrating that thyroid follicular cells from both disorders are capable of presenting alloantigens. In contrast the proliferation of autologous peripheral blood mononuclear cells was more efficiently stimulated by thyroid follicular cells from Graves' disease than from nontoxic goiter. Cultured intrathyroidal T lymphocytes proliferated specifically in response to autologous HLA class II+ thyroid follicular cells in Graves' disease, but not in nontoxic goiter. The responses were dose dependent and HLA class II restricted. Thyroid autoantigen presentation by HLA class II expressing thyroid follicular cells thus only occurs in Graves' disease, suggesting that HLA class II expression on thyroid follicular cells is an essential feature, but by itself not sufficient for the induction of autoimmunity. Additional factors, the possible nature of which is discussed must also be involved.

Adult↗
PubMed1987

[Detection of primary aldosteronism using the captopril test].

In order to evaluate whether changes in the plasma concentration of aldosterone (PA) following the administration of captopril, an inhibitor of angiotensin-converting enzyme, will establish the diagnosis of primary aldosteronism we have used this test in 9 healthy subjects and in 22 patients with various forms of hypertension, including 5 patients with primary aldosteronism due to idiopathic adrenal hyperplasia (n = 4) or aldosterone-producing adenoma (n = 1). The response of PA to captopril (25 mg orally) was investigated on an outpatient basis, following a rest period of 120 minutes in the supine position. In healthy subjects PA decreased from a mean basal value of 11.5 +/- 5.9 ng/dl to less than 6.4 ng/dl (4.9 +/- 1.4 ng/dl [p less than 0.01]). Similarly, captopril induced a fall in PA concentration to less than 6.4 ng/dl in patients with essential hypertension, with renal artery stenosis or with an afunctional kidney. Post-captopril concentrations of plasma aldosterone were about twice the normal level in 3 of 4 patients with idiopathic adrenal hyperplasia and about four-fold raised above normal in the patient with an aldosterone-producing adenoma. In spite of a false-negative result in one patient with idiopathic adrenal hyperplasia, the administration of captopril appears to be of use in recognizing patients with primary aldosteronism on an outpatient basis.

Adenoma↗
PubMed1987

Possible adverse effect of failed adjuvant chemotherapy on the prognosis of women receiving consecutive chemotherapy for recurrent breast cancer.

This study tried to evaluate the impact of adjuvant chemotherapy on the induction of chemoresistance in radically operated upon breast cancer patients. Remission rate, remission duration and survival of a group of women (n = 22) treated with combination chemotherapy (adriamycin and cyclophosphamide, AC) for recurrent breast cancer after failed adjuvant therapy (cyclophosphamide, methotrexate, fluorouracil, vinblastine) were retrospectively compared with the clinical data of non-pre-treated patients (n = 28) receiving the same regimen (AC). The two groups of patients were comparable with regard to their risk factors. In the group of women with prior adjuvant chemotherapy only 3 out of 22 had a partial response, lasting 3, 8, and 16 months; the median survival was 50 months. In the group without prior adjuvant therapy 3 complete and 7 partial remissions with a median remission duration of 15.5 months (range 2-54 months) were found; the median survival was 104 months. The percentage of objective responses among the non-pre-treated patients at 36% was almost significantly higher than that of the pretreated women with 14% (p less than 0.1). Responders to chemotherapy after relapse profited in terms of survival within the first 3 years after radical mastectomy, although no statistically significant difference was observed. The survival data shown assume a "shifting" of women from a group with better prognosis to a group with unfavourable prognosis following failed adjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Effect of prolonged administration of CRF on plasma concentrations of ACTH in patients with Addison's disease.

To investigate the possibility that the prolonged administration of corticotropin releasing factor (CRF) might suppress rather than enhance pituitary ACTH-secretion 24-hour infusions (50 micrograms/h) of ovine CRF were performed in 6 patients with adrenocortical insufficiency. CRF induced a heterogeneous behaviour of plasma ACTH concentrations in these hypercorticotropinemic patients but both a sustained increase and a suppression of ACTH was clearly absent at the end of the 24 hour infusion period. Thus, continuous administration of CRF does not appear to be a promising way to control abundance of plasma ACTH concentrations in patients with Addison's disease.

Addison Disease↗
PubMed1985

[Corticotropin releasing factor as an aid in the diagnosis of Cushing syndrome].

6 patients with Cushing's syndrome were investigated with regard to the effect of synthetic ovine corticotropin-releasing factor (o-CRF), administered as an intravenous bolus of 100 micrograms, on peripheral plasma concentrations of ACTH and cortisol. The purpose of this study was to evaluate the usefulness of this "CRF test" in the differential diagnosis of Cushing's syndrome as compared with conventional diagnostic procedures. 100 micrograms CRF caused a rise in plasma ACTH and cortisol in patients with bilateral adrenal hyperplasia (n = 3). However, in patients with cortisol-producing adrenal adenoma (n = 2) and ectopic ACTH overproduction (n = 1), no increase in plasma cortisol and ACTH was induced by exogenous CRF. We conclude from these findings that the CRF test will prove a valuable diagnostic tool to differentiate pituitary from extrapituitary forms of endogenous hypercortisolism in patients with Cushing's syndrome.

Adolescent↗
PubMed1985

Low antithrombin III and high plasma fibronectin in pre-eclampsia.

Antithrombin III activity and plasma fibronectin levels were determined in patients with preeclampsia. In several cases low antithrombin III and high plasma fibronectin concentrations could be related to proteinuria. Altered plasma fibronectin and antithrombin III concentrations might contribute to a hypercoaguable state in patients with preeclampsia.

Adolescent↗
PubMed1985

Plasma fibronectin and thyroid function.

Plasma fibronectin concentrations up to 85 mg/100 ml were found in hyperthyroid patients. There was a significant correlation between free thyroxine index and plasma fibronectin values. Hypothyroid patients had low to normal fibronectin concentrations. Parallel decreases of thyroid hormones and plasma fibronectin concentrations were noted during treatment with thiamazole. A direct effect of thyroid hormones on fibronectin synthesis seems probable.

Adult↗