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Biomedical subjects

K H Usadel

Publications and source records attributed to K H Usadel.

At least 19 recordsLinked to original sources
PubMed2005

Bone mineral density changes and bone turnover in thyroid carcinoma patients treated with supraphysiologic doses of thyroxine.

The aim of this one-year prospective study was to determine whether longterm thyroxine treatment is a risk factor for elevated bone turnover, loss of bone mass and subsequent development of osteoporosis. Premenopausal women (N = 19), and men (N = 9) suffering from differentiated thyroid gland carcinoma in the mean age of 39.0 +/- 8.0 years and 41.8 +/- 10.0 years were investigated. All of them had undergone a total thyroidectomy and subsequent thyroxine therapy. The duration of the TSH-suppressive therapy prior to the the beginning of our study was 9.4 +/- 6.4 years in the female and 8.1 +/- 6.0 years in the male group. The prospective observation was performed by dual X-ray absorptiometry (DXA) at the spine and the femoral neck and by single-photon absorptiometry (SPA) at the distal radius. Laboratory testings included thyroid hormones T3, T4 and TSH, serum calcium, phosphate and PTH, and urinary calcium and phosphate from spontaneous and 24-hour urine samples. Markers of bone formation (osteocalcin, alkaline phosphatase and PICP) and resorption (Ca/Cr and ICTP) were determined. Statistically significant loss of bone mass was observed only on the distal radius in males (p<0.05). At the lumbar spine and femoral neck, only a minor bone loss was registered in a small number of patients. Almost 50 % of the females showed values above the reference range. In more than 30 % of the females, and smaller number of male patients, ICTP values ranged above the reference range, corresponding to elevated bone turnover. These two variables exhibited a slight correlation with bone density at the measured skeletal areas, mostly considering the male group. The results are a proof that accelerated bone turnover and subsequent bone loss occurs during TSH-suppressive thyroxine therapy. In future prospective studies a prolonged time of observation will be necessary, as well as to increase the number of studied patients, in order to better assess the relative risk of osteoporosis in patients undergoing TSH-suppressive treatment more precisely.

Absorptiometry, Photon↗
PubMed2005

Pre-meal insulin aspart compared with pre-meal soluble human insulin in type 1 diabetes.

Insulin aspart has been shown, in medium-term studies, to achieve reductions in HbA(1c) without increasing the risk of major hypoglycaemia compared with pre-meal human insulin. The aim of the present 3-year study was to evaluate the long-term safety and efficacy of insulin aspart in people with type 1 diabetes. This was a 30-month extension of a multinational, multicentre, open-label, parallel-group study of 753 people with type 1 diabetes, originally randomly allocated to treatment with insulin aspart or unmodified human insulin before meals, with NPH insulin as basal insulin. Main outcomes measures were hypoglycaemia (major or minor), adverse events and HbA(1c). As insulin aspart became commercially available in some countries before the end of the trial, analyses of HbA(1c) used 30-month data to maintain statistical power. The relative risk estimate of major hypoglycaemia was similar between treatment groups (relative risk [RR] 1.00 [95% CI 0.72, 1.39]). The risk of having a minor hypoglycaemic episode was higher with insulin aspart than with human soluble insulin (RR 1.24 [1.09, 1.39] p=0.024). Insulin aspart was significantly superior to human insulin with respect to overall glycaemic control, with a baseline-adjusted HbA(1c) difference of -0.16 (-0.32, -0.01)% (p=0.035). Insulin aspart was well tolerated and effective during long-term treatment. The HbA(1c) advantage was maintained with insulin aspart without any adverse impact on the rate of major hypoglycaemia.

Adult↗
PubMed2005

Isolation of thyroid cells obtained by fine-needle aspiration biopsy.

Usually thyroid cells isolated from tissue obtained by surgery or thyroid cell lines are used to investigate the pathogenesis of autoimmune thyroid diseases. Isolation and cultivation of thyrocytes from fine-needle aspiration biopsy (FNAB) has not yet been published. The aim of this study was to isolate and cultivate thyrocytes from samples of FNAB. FNAB samples were obtained from nine adults and nine children with Hashimoto's thyroiditis (HT). The aspiration material was filtered resulting in small samples of tissue on the surface of the filter membrane. These tissue fragments were digested by collagenase I and dispase II. The yielding cells were cultivated for 3 weeks in Ham's F12 Kaighn's Modification medium in presence of 1 mU/mL bovine thyrotropin (TSH), 10 microg/mL human insulin, 6 microg/mL transferrin, and 10(-8) M hydrocortisone. Finally, isolated thyroid cells were characterized by determination of gene expression of thyrotropin receptor (TSHR), thyroperoxidase (TPO), and thyroglobulin (Tg) using a nested reverse transcriptase-polymerase chain reaction (RT-PCR). Thyroid cells obtained by FNAB can be maintained over a time period of approximately 3 weeks. Depending on the sample size a final number of 1000-14,000 cells was gained per FNAB. In addition, all cells isolated by the described method expressed TPO mRNA. TSHR mRNA was found in 4 samples, whereas 15 samples were Tg mRNA-positive. There were no differences with respect to the expression TSHR and TPO mRNA between samples from adults and children. The isolation and cultivation of thyroid cells obtained by FNAB has been established. In contrast to surgical specimen, this technique provides an easy access to thyrocytes derived from individual patients allowing repeated sampling to investigate the time progression of the chronic disease or the effect of treatment over time.

Adolescent↗
PubMed2004

Lymphocyte homing in xenotransplanted human thyroid tissue can be inhibited by LFA-1 and ICAM-1 antibodies.

OBJECTIVES: Homing of lymphocytes is an important factor with respect to the initiation of the autoimmune process in Graves' disease (GD). As previously shown, human lymphocytes, particularly of intrathyroidal origin, derived from patients with GD, are able to migrate into normal xenotransplanted thyroid tissue and induce functional and histological changes. The aim of this study was to investigate the effect of LFA-1 and ICAM-1 antibodies on the homing of lymphocytes of different origin into xenografted human thyroid tissue. METHODS: Eighty-five nude mice bearing 8-week-old xenografts of normal human thyroid tissue were treated twice with anti-CD 54 (anti-ICAM-1), anti-CD 11a (anti-LFA-1), a combination of both, or, serving as controls, iso-antibodies without specific binding capacity or saline. Thereafter, intrathyroidal (ITL) or peripheral blood lymphocytes (PBL) obtained from 4 patients with GD or saline were injected into the animals (i.v., 0.2 mL, 10(6) cells). After 48 hours the mice were sacrificed and transplants as well as mice thyroids were examined by immunohistochemical staining with Ki67, CD3, HLA-II (DAKO, Hamburg), IgG, CD44, ICAM-1, and VCAM-1 (Immunotech, Hamburg). RESULTS: Pretreatment with anti-ICAM-1 and anti-LFA-1 decreased lymphocyte homing (CD3-staining), and expression of HLA-II, IgG, CD44, and VCAM-1 in the transplants. CONCLUSION: Our data show that [ICAM-1/LFA-1 stimulated (induced)] lymphocyte homing and subsequently thyrocyte proliferation are inhibited by ICAM-1 and LFA-1 antibodies in xenotransplanted thyroid tissue. This suggests that ICAM1 and LFA-1 play an important role in the early steps of autoimmune thyroid disease. The inhibition/suppression of ICAM-1 and LFA-1 interaction by respective antibodies, as demonstrated in the present study, may provide a new concept for prophylaxis and therapy.

Animals↗
PubMed2003

[Autoimmune thyroiditis. Treatment with thyroid gland hormones in subclinical hypothyroidism or already in euthyroid state?].

In patients with subclinical hypothyroidism thyroid hormone therapy should be recommended more often with respect to analysis of effectiveness and risks. There is no cost-difference between treated patients and those who undergo thyroid hormone controls only, but thyroid hormone therapy probably induces improvement of clinical and laboratory parameters and reduction of cardiovascular risk factors. These therapeutic effects have to be elucidated in clinical prospective studies. Thyroid hormone therapy of patients with autoimmune thyroiditis and still euthyroid function obviously inhibits the autoimmune process and development of hypothyroidism. A final recommendation, however, can be given after the data of clinical studies with larger populations are available.

Adult↗
PubMed2003

[Optimal recurrence prevention of iodine deficiency related goiter after thyroid gland operation. A prospective clinical study].

In summary the data of our study show: (1) Sonographically determined thyroid volume of patients with euthyroidism after surgery is found to be significantly lower with a combination therapy (iodide 150 microgram +Levothyroxine 75 microgram) compared to patients with iodide monotherapy (200 microgram). (2) Thyroid volume of patients with hypothyroidism after surgery is found to be significantly lower during a combination therapy (150 microgram iodide + 75 microgram L-thyroxine) compared to patients with a Levothyroxine monotherapy. (3) Patients with hypothyroidism and Levothyroxine monotherapy, however present with a significant increase of thyroid volume after surgery. (4) Urinary iodide excretion in the treatment groups with iodide or combination therapy increases significantly during therapy, however, patients with Levothyroxine monotherapy do not show changes. (5) Thyroid function is well stabilized in all treatment groups with adequate controls and adjustment of Levothyoxine dosage. There data clearly demonstrate that the combination therapy with Levothyoxine and iodide significantly improves prophylaxis of goiter recurrence.

Adult↗
PubMed2002

A retroviral long terminal repeat adjacent to the HLA DQB1 gene (DQ-LTR13) modifies Type I diabetes susceptibility on high risk DQ haplotypes.

AIMS/HYPOTHESIS: HLA-DQ genes, located in the human leukocyte antigen region on chromosome 6 p, are the main inherited factors predisposing to Type I (insulin-dependent) diabetes mellitus. Endogenous retroviral long-terminal repeats are integrated at several sites within this region, one of which is known to enhance susceptibility for Type I diabetes. We examined another LTR within the HLA-region as an additional genetic risk marker. METHODS: We investigated the segregation of one long-terminal repeat (DQ-LTR13), located 1.3 kb upstream of HLA DQB1 with different HLA-DQ haplotypes, and its transmission to patients. A total of 284 Caucasian families (203 German and 81 Belgian) with at least one diabetic offspring were genotyped for DQA1, DQB1 and DQ-LTR13. RESULTS: DQ8/LTR13(+) was preferentially transmitted (139 transmitted vs 28 not transmitted; P(TDT) = 1.67 x 10(-14)) whereas no deviation from expected transmission frequencies was observed for DQ8/LTR13(-) (20 transmitted vs 17 not transmitted; P(TDT) = 1.00). DQ8/LTR13(+) alleles conferred a significantly higher risk for Type I diabetes than DQ8/LTR13(-) alleles (p chi(2) = 2.58 x 10(-14)). This difference remained significant even after DRB1 subtyping (p chi(2) = 0.02). Also, there was a significant difference when comparing the transmission of DQ2/LTR13(+) and DQ2/LTR13(-) alleles (p chi(2) = 0.01), the latter conferring an increased risk. The transmission of DQ-LTR13(+) haplotypes did not show any differences regarding paternal, maternal or gender-related stratification. However, DQ8/LTR13(-) was significantly more often transmitted from mothers (p chi(2) = 0.01) and to female patients (p chi(2) = 0.04). CONCLUSION/INTERPRETATION: We conclude that DQ-LTR13 marks additional genetic risk for Type I diabetes on predisposing DRB1(*)0401- DQ8 and DQ2 haplotypes and will help to further define susceptibility in this gene region.

Base Sequence↗
PubMed2002

Unbalanced amounts of HLA-DQA1 allele mRNA: DQA1*03 shows high and DQA1*0501 low amounts of mRNA in heterozygous individuals.

Genes of the HLA-DR, DQ region confer strong susceptibility to type 1 diabetes mellitus (IDDM). A possible mechanism of susceptibility is a difference in the amounts of transcripts of predisposing and neutral or protective haplotypes. In this study we developed an assay to compare the amounts of mRNA of two distinct HLA-DQA1 alleles in peripheral blood lymphocytes (PBLs) of heterozygous individuals, using a quantitative RT-PCR with an internal standard covering all HLA-DQA1 specifities. We also developed an algorithm to calculate the amounts of mRNA for two distinct alleles in heterozygous individuals based on the comparison to the same internal standard. In total, 37 HLA-DQA1 heterozygous individuals were analysed, including patients with IDDM (n = 14) and healthy controls (n = 23). Intra-individually, we observed different amounts of mRNA for different HLA-DQA1 alleles in the order: HLA-DQA1*03 > *01 > *0201 > *05. This order was observed in all individuals. We also observed a variation in the ratio of these unbalanced amounts of mRNA in individuals with the same HLA-DQA1 allele combinations. In all allele combinations the average ratio was increased in patients with IDDM compared to the control samples. HLA-DQA1*03 positive and DQA1*03, *05 heterozygous patients had the highest average ratios. Nevertheless, based on limited sample numbers, these differences did not reach significance. We therefore conclude that variations between HLA-DQA1 alleles are not limited to the nucleotide sequence but are also found at the level of amounts of mRNA.

Diabetes Mellitus, Type 1↗
PubMed2002

Detection of thyroid peroxidase mRNA in peripheral blood of patients with malignant and benign thyroid diseases.

The aim of this study was to evaluate thyroid peroxidase (TPO) mRNA expression in peripheral blood of patients with benign and malignant thyroid disease. Included were 120 thyroid cancer patients, 85 patients with goitre or Graves' disease (GD) and 54 healthy volunteers. TPO mRNA expression was analysed in peripheral blood by nested RT-PCR. In cancer patients, RT-PCR results were compared with staging, grading and serum thyroglobulin (TG) measurement. TPO transcripts were detected in 7/10 (70%) patients with known metastases of thyroid cancer and in 39 of 110 (36%) patients without metastases (P<0.05), in 15/44 (34%) patients with goitre, in 17/41 (41%) cases with GD and in 4/54 (7.4%) subjects in the control group (P<0.05, controls vs all patients with thyroid disease). Among cancer patients without metastatic disease, RT-PCR results correlated positively with lymph node status (P=0.05), grading (P=0.01) and elevated serum thyroglobulin levels (P=0.03). This is the largest study investigating the use of the TPO-RT-PCR assay. Positivity in TPO-RT-PCR correlates significantly with metastatic disease in cancer patients and with the presence of thyroid disease in general. To date, TPO-RT-PCR cannot substitute for standard techniques in the diagnosis of local recurrence or metastatic spread in thyroid cancer patients. However, as results of TPO-RT-PCR correlate significantly with lymph node status, grading and serum TG measurements in patients with non-metastatic disease, TPO seems to be an interesting molecular marker to look at in follow-up studies.

Adult↗
PubMed2001

Circulating calcitonin and carcinoembryonic antigen m-RNA detected by RT-PCR as tumour markers in medullary thyroid carcinoma.

Detection of local relapse or metastasis in medullary thyroid carcinoma (MTC) continue to pose a major diagnostic challenge. Besides established diagnostic studies such as serum calcitonin (CT) and carcinoembryonic antigen (CEA), molecular detection of circulating tumour cells may be an additional diagnostic tool for the early detection of disease recurrence. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with MTC disease using primers specific for CT and CEA, respectively. CT mRNA was not detectable in peripheral blood of all patients with MTC (n = 11) and all controls (n = 32). CEA mRNA was significantly more often detected patients with MTC (72.7%) than in controls (34.4%; p = 0.038; Fisher exact test). With an example of a patient with MTC and massive tumour mass in the neck we demonstrate the failure of detection of CT mRNA over a period of 6 months, whereas CEA mRNA could be detected in peripheral blood of this patient. As a consequence, CT mRNA detected by RT-PCR in the peripheral blood can not be recommended as a tumour marker in MTC. However, the use of carcinoembryonic mRNA may provide a significant improvement in diagnosis of recurrent disease in MTC.

Biomarkers, Tumor↗
PubMed2001

Impact of cyclosporine and low-dose steroid therapy on insulin sensitivity and beta-cell function in patients with long-term liver grafts.

To examine whether factors controlling glucose tolerance, i.e., insulin sensitivity (SI) and first-(phi1) and second-phase insulin secretion (phi2), are impaired in after orthotopic liver transplantation (OLT), they were assesssed in patients that had undergone OLT for cirrhosis (n = 10) with cyclosporin A and low-dose steroid therapy (5 mg prednisone per day) and were compared with those of healthy matched control subjects (n = 10). These factors were determined by means of computer-based analysis of frequently sampled intravenous glucose tolerance tests (FSIGTT). Glucose and insulin profiles (posthepatic insulin) did not differ between both groups, whereas C-peptide levels (prehepatic insulin) were elevated in the transplant group after the FSIGTT, indicating an increased hepatic insulin degradation. SI and (phi1 did not differ between both groups. phi2, however, was significantly enhanced (23.94 +/- 2.63 vs 13.88 +/- 1.25 min(-1), P < 0.05). These results indicate that cyclosporine and low-dose steroid therapy do not impair SI and phi1. However, enhanced phi2 compensates the increased hepatic insulin clearance.

Adult↗
PubMed2001

Fluvastatin therapy improves microcirculation in patients with hyperlipidaemia.

The purpose of this study was to investigate the effect of fluvastatin on the microcirculation of patients with hyperlipidaemia (low-density lipoprotein cholesterol > 160 mg/dL, triglycerides < 350 mg/dl) inadequately controlled by diet. After a dietary run-in of 4 weeks, patients were randomised in a double-blind study to receive fluvastatin 40 mg twice daily (n = 24) or placebo (n = 24) for 12 weeks. The effect on microcirculation was assessed using capillary microscopy and laser Doppler fluxmetry at the nailfold at baseline and at 6 and 12 weeks after initiation of therapy. Capillaroscopy showed that fluvastatin improved microcirculation, i.e. time to peak flow during postocclusive reactive hyperaemia dropped from 19.7 +/- 7.2 s at baseline to 12.3 +/- 9.5 s at week 6 (P < 0.01) and 10.6 +/- 6.5 s at week 12 (P < 0.0001). These results were confirmed using laser Doppler fluxmetry to study microcirculation in thermoregulatory capillaries at the same site. A significant decrease in total and LDL-cholesterol was achieved during fluvastatin therapy. In conclusion, fluvastatin therapy improves microcirculation in nutritive as well as thermoregulatory capillaries in hypercholesterolaemic patients within 6 weeks.

Anticholesteremic Agents↗
PubMed2001

Panhypopituitarism associated with severe retroperitoneal fibrosis.

A 43-year-old man, with a history of central diabetes insipidus diagnosed 3 years previously, complained about reduced libido. An MRI scan showed a suprasellar lesion just below the supraoptic recess of the third ventricle. A stereotactically guided biopsy revealed fibrous glia, but no other specific tissue and no inflammatory cells. Two months later the patient presented with fatigue and muscular weakness. Tertiary adrenal failure and hypothyroidism were diagnosed by endocrine function tests and therapy with levothyroxine and hydrocortisone was started. Another 2 months later the patient was admitted with giddiness, nausea, peripheral oedema and oliguria. Radiological imaging and an open transperitoneal kidney exploration showed severe fibrosis around both ureters. Histological examination confirmed the diagnosis of idiopathic retroperitoneal fibrosis. Presumably the suprasellar tumour was the first manifestation of retroperitoneal fibrosis. Once the diagnosis 'idiopathic retroperitoneal fibrosis' is confirmed, fibrotic manifestations and complications involving extra-retroperitoneal tissues including the endocrine system, should be sought.

Adult↗
PubMed2001

Screening for an AIRE-1 mutation in patients with Addison's disease, type 1 diabetes, Graves' disease and Hashimoto's thyroiditis as well as in APECED syndrome.

OBJECTIVE: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare systemic autoimmune disorder of monogenic and autosomal-recessive inheritance. To date, 29 APECED causing mutations have been identified in the responsible gene AIRE-1, coding for a regulator of transcription. The aim of this study was to examine whether mutations in AIRE-1, in their heterozygous form, predispose to the more common isolated autoimmune endocrinopathies Addison's disease, type 1 diabetes mellitus, Graves' disease and Hashimoto's thyroiditis. DESIGN: Patients with isolated autoimmune endocrine disorders as well as healthy controls were analysed for two of the most common AIRE-1 mutations, mutation R257X in exon 6 and a 13-bp deletion in exon 8. Mutations were detected by polymerase chain reaction based techniques. PATIENTS: In total, 726 individuals were investigated for mutation R257X. Subjects comprised patients with Addison's disease, IDDM, Graves' disease and Hashimoto's thyroiditis. With regard to the 13 bp deletion we could screen 91 patients with Addison's disease. In addition, six patients with the APECED syndrome including one family were analysed for both mutations. RESULTS: Out of the 12 alleles in APECED patients six contained either mutation R257X or the 13 bp deletion, confirming that these mutations prevail in Europe. R257X was found in one subject with Hashimoto's thyroiditis in its heterozygous form. The 13 bp deletion was not detected in any subject with Addison's disease. CONCLUSIONS: The two studied AIRE-1 mutations are so rare in the general population that they can not contribute to susceptibility for the more common isolated autoimmune disorders.

Addison Disease↗