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Biomedical subjects

K M Schulte

Publications and source records attributed to K M Schulte.

At least 19 recordsLinked to original sources

Mutation and methylation analysis of TP53 in adrenal carcinogenesis.

AIM: To investigate the role of coding region mutation and promoter hypermethylation of TP53 in adrenocortical cancer formation. METHODS: Twenty sporadic adrenocortical cancers (ACCs) and five normal adrenal tissue samples were available for analysis. Coding region mutation of TP53 in 20 ACCs was examined by polymerase chain amplification using intronic primers for exons 2-11 and direct sequencing of the product. In 10 ACCs and five normal adrenal tissue specimens, methylation of the 16 CpG sites within the TP53 promoter was examined using bisulphite methylation sequencing. RESULTS: Coding region mutation in TP53 was demonstrated in 5 of 20 ACCs. There were four mis-sense mutations and one frameshift mutation. Four of 5 patients with a TP53 mutation had metastases at diagnosis or detected soon thereafter and 3 of 4 died of disease within 12 months of surgical resection. No methylation was seen in the TP53 promoter in 10 ACC and the five normal adrenal tissues examined. CONCLUSION: Coding region mutation in TP53 occurs in 25% of ACCs with a trend toward a poorer prognosis. Promoter methylation of TP53 is not present in ACC as a mechanism for tumour suppressor gene (TSG) inactivation and, therefore, other genes in the 17p13 region are implicated in adrenal carcinogenesis.

Adrenal Gland Neoplasms↗

[Economic restraints shorten the length of hospital stay: thyroid operation as a model case].

INTRODUCTION: Decreasing the length of stay is a possible means of cost control in the medical system. Therefore we performed a study to test the feasibility of reducing hospital stay to 2 days after thyroid operation. METHODS: In a controlled prospective trial, 238 patients were randomly assigned to group A (2 days of stay) or group B (more than 2 days). Studied were medical standard, practicability, patient acceptance, and quality of life. RESULTS: Of those in group A, 56.6% did not leave the hospital at the scheduled 2nd day post operation. Reasons were preoperative hyperthyroidism ( P<0.011), postoperative hypocalcemia ( P<0.03), or unspecific disturbances. In group B, 28% of the patients left before the established borderline of 3-4 days, and only 35% left on the 2nd postoperative day. CONCLUSION: Reduced length of stay has no negative influence on medical standards. The quality of life of patients leaving the hospital on the 2nd postoperative day was significantly higher. Reducing hospital stay after thyroid operation to 2 postoperative days is desirable and possible without a loss in quality of care, except in case of postoperative complications or unspecific complaints.

Adult↗

No association of IL-1beta C + 3954 T polymorphism and thyroid disease.

Interleukin-1 is a potent pro inflammatory agent, has a direct influence on human thyroid cell function, and modulates cell growth in differentiated thyroid carcinoma cell lines. To evaluate whether a polymorphism on the IL-1beta gene has an influence on the incidence of thyroid disorders, we analyzed the C + 3954 T polymorphism in DNA samples of 673 individuals. 414 venous blood samples were collected from patients suffering from thyroid diseases (Graves' disease n = 53, euthyroid or hyperthyroid non-immunogenic benign thyroid disorders n = 240, thyroid carcinoma n = 121). 259 persons without thyroid disease served as a control. There was no statistically significant association between either of the thyroid alterations or functional conditions on the one hand and the examined genetic polymorphism on the other. Because of the large number of samples tested we can conclude with a high degree of confidence that there is no association between the genotype and the surveyed diseases.

Adolescent↗

Multiple neuroendocrine tumors of the pancreas associated with pancreas divisum.

Pancreas divisum is the most common congenital anomaly of the pancreas, characterized by missing fusion of the ventral and dorsal pancreatic duct. It may cause pancreatitis, but is rarely associated with malignancy.We report herein for the first time the rare association, in a symptomless patient, of multiple neuroendocrine tumors of the pancreas with pancreas divisum and a failure of the exocrine system. Diagnosis was made incidentally by routine abdominal ultrasound. Laboratory examinations and a fine-needle aspiration revealed the neuroendocrine nature of the tumor. Spleen-preserving left pancreas resection was performed, with evidence of multiple neuroendocrine tumors of the pancreas with the typical histological characteristics. Eighteen months later the patient is still free of tumor burden.

Biopsy, Needle↗

Lysophosphatidic acid, a novel lipid growth factor for human thyroid cells: over-expression of the high-affinity receptor edg4 in differentiated thyroid cancer.

Lysophosphatidic acid (LPA) is a small lipid mediator with pleiotropic biological activities, e.g., the regulation of cellular proliferation and various aspects of cellular physiology. Signal transduction is achieved by binding to 2 high-affinity receptors, EDG2 and EDG4, and a group of low-affinity receptors, EDG1-7, all belonging to the superfamily of G protein-coupled receptors. We examined the growth-regulatory effects of LPA in primary cultures of 8 goiters and 1 papillary thyroid cancer. We further assessed mRNA expression of high-affinity receptors EDG2 and EDG4 in 14 normal thyroids, 29 papillary thyroid cancers, 7 follicular thyroid cancers and 13 goiters by quantitative RT-PCR. We also identified mRNA expression of phospholipase A(2) and LPA acyltransferase in fresh thyroid tissues derived from various sources. At concentrations of 10, 50 and 150 microM, LPA induced a 2-fold rise of proliferation (p < 0.001) and acted as strongly as thyrotropin. The combination of LPA and TSH produced significant synergistic effects compared with each substance alone (p < 0.05). Normal thyroid, goiter and papillary or follicular thyroid cancer expressed 2 high-affinity cognate LPA receptors, EDG2 and EDG4. EDG4 receptor mRNA expression was increased 3-fold in differentiated thyroid cancer (p < 0.01), both papillary (p < 0.01) and follicular (p < 0.05), compared to normal thyroid or goiter. Overall expression of EDG2 receptor was unchanged in malignancy; however, increased EDG2 expression in individual samples correlated with lymphonodular metastasis (p = 0.01). Thus, lipid mediators are a novel class of factors involved in the control of proliferation in the human thyroid. Altered mRNA expression of the high-affinity LPA receptor EDG4 suggests a role in the pathogenesis of differentiated thyroid cancer.

Acyltransferases↗

The determination of ketone bodies: preanalytical, analytical and physiological considerations.

The arterial ketone body ratio is calculated as the ratio of arterial levels of acetoacetate/beta-hydroxybutyrate. It correlates with survival in experimental hemorrhagic shock and outcome after liver surgery and myocardial infarction. Procedures for determination of ketone bodies are often laborious and unreliable. As yet the relationship between results from arterial and venous samples is unclear. We therefore describe the determination of the ketone bodies acetoacetate and 3-hydroxybutyrate by an easy, reliable, rapid, inexpensive enzymatic assay using 3-hydroxybutyrate dehydrogenase (E.C. 1.1.1.30) in a semi-automated setting that does not require deproteinization. Preanalytical parameters, including separation from corpuscular elements within 1 h and storage on ice for less than 1 h, must be strictly observed to avoid rapid decay of acetoacetate by spontaneous decarboxylation. The assay has high sensitivity, specificity (+/-5%), and precision (CV <2.5%) with a measurable range of 5-500 micromol/l for either ketone body, and requires only 23.5 microl of plasma. At temperatures below -17 degrees C plasma may be stored for prolonged periods. Results from prospectively scheduled simultaneous sampling of arterial blood and venous blood from the right atrium in 100 consecutive patients with severe multiple trauma (mean Injury Severity Score 38+/-13) support the view that the lung has no role in ketone body metabolism. We conclude that central venous blood can safely be substituted for arterial blood for determination of the ketone body ratio.

3-Hydroxybutyric Acid↗

Genetic determinants of IL-6 expression levels do not influence bone loss in inflammatory bowel disease.

Bone loss in inflammatory bowel disease (IBD) is presumed to be mediated by inflammation. Increased levels of the multifunctional cytokine IL-6 in inflammatory diseases have been proposed to be the link in such "inflammation-mediated osteopenia." A recently described G/C polymorphism with an effect on transcription rate and plasma levels of IL-6 suggests a genetically determined difference in the degree of the IL-6 response to stressful stimuli between individuals. This study aimed to assess the frequency of genotypes and haplotypes of the G/C polymorphism of IL-6 in IBD patients. A further aim was to assess whether carriage of the potentially protective CC genotype is favorable with respect to the development of bone disease in IBD. The IL-6 polymorphism was typed in 105 IBD patients and 113 healthy controls. Bone mineral density was evaluated at baseline and after a prospective 2-year-follow-up. The favorable CC genotype with decreased IL-6 release was not underrepresented in IBD patients compared to healthy controls. Carriage of this genotype was not protective with respect to the development of bone disease, either for the bone mineral density at baseline or for the prospectively observed bone loss. Within the subgroup of patients who did not receive steroids during follow-up, the prospectively observed bone loss was even slightly higher in CC carriers, but differences did not reach significance. Genetically determined differences in the degree of the IL-6 response to stressful stimuli are no major predictors for the degree of bone disease in IBD patients.

Adult↗

Activin A and activin receptors in thyroid cancer.

Proliferation is controlled by a network of mitogenic and growth inhibitory factors. Transforming growth factor-beta1 (TGF-beta1) and activin A are the most important growth inhibitors of benign follicular epithelial cells of the human thyroid. The effects of these substances on malignant primary thyrocytes are not known. We have examined the growth regulatory effects of activin A and TGF-beta1 in primary cultures derived from four papillary cancers, two follicular thyroid cancers, and three benign thyroid tissues. Malignant cells demonstrated resistance to activin and TGF-beta1 or reversal to a weak but significant mitogenic effect (p < 0.001). We also evaluated the activin receptor transcription pattern. Isoforms alk4-1, 4-2, and 4-3 were found in benign (n = 12) and malignant (n = 22) tissues. Two subtypes of type I and type II activin receptors were demonstrated. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) demonstrated a significant threefold downregulation of alk4-1 receptors in papillary (n = 25) and follicular (n = 18) thyroid cancers as compared to normal thyroids (n = 12) (p < 0.001). To our knowledge these are the first data to demonstrate reversal of activin and TGF-beta1 effects in thyroid malignancy and to demonstrate changes of the type Ib activin receptor expression in thyroid malignancy.

Activin Receptors↗

[Monitoring the recurrent laryngeal nerve as a routine measure in thyroid gland surgery].

Intra-operative monitoring of the recurrent laryngeal nerve by electromyography of the inner laryngeal muscles facilitates the nerves preparation. The positive and negative predictive values of the method with regard to vocal cord function have not sufficiently been examined. Prospective randomized data concerning the usefulness with regard to permanent nerve palsy rates are lacking. The impressive reduction in palsy rates over the last 20 years is due to routine preparation and protection of the visualized nerve. This principle must not be abandoned. Depending on the setting, neuromonitoring may be a valuable help. It is not an obligation in thyroid surgery.

Electromyography↗

[Neurostimulation of the recurrent laryngeal nerve--a routine method in thyroid gland surgery?].

INTRODUCTION: Thyroid operations belong to the most frequent procedures in Germany (100,000/year). An important quality parameter is the incidence of postoperative recurrent nerve paralysis. Intraoperative identification by visualization of the nerve with a paralysis rate of 1% is the present gold standard in dedicated centers. PROBLEM: Can this results be further improved by use of an intraoperative neuromonitoring system (NM). RESULTS: The use of NM is helpful in difficult situations (recurrent goiter, advanced carcinoma, anatomic variants), but a quality improvement is not yet proven. CONCLUSION: NM can not replace the current nerve identification by meticulous preparation of anatomic structures. It should be used at the discretion of the operative surgeon.

Electrodiagnosis↗

Growth regulation of thyroid and thyroid tumors in humans.

In a study of growth regulation of the human thyroid gland and thyroid tumors we investigated the impact of iodine and that of the thyroid-specific growth-stimulating hormone TSH. Further studies included locally active growth factors such as the epidermal growth factor, insulin-like growth factor, and tissue transforming growth factors alpha and beta. In addition to studies of growth regulation by the various growth factors in mostly normal thyrocytes, the impact of tumor-specific mutations in oncogenes and tumor-suppressor genes was investigated. The results demonstrated distinct changes in tissue specificity and sensitivity to external stimuli. This rather complex view on thyrocyte growth regulation may be confusing, but it describes the biologic reality more precisely. Increased knowledge of the regulatory processes may lead to the development of new tumor- and patient-specific therapeutic approaches, especially for preventing benign goiter recurrence and for treating follicular and papillary thyroid cancers.

Genes, Tumor Suppressor↗

Coral reef aorta: a long-term study of 21 patients.

Coral reef aorta is a rare calcifying disease of the juxtarenal and suprarenal aorta. We report here our surgical experience in treating 21 patients, with a mean follow-up of 4 years and 7 months. Both genders were equally affected. Ten male (48%) and 11 female (52%) patients with a mean age of 54.6 years (range 42-76 years) underwent surgery. The main symptoms were limb claudication (n = 11, 52%), renovascular stenosis (n = 9, 43%) with concurrent renovascular hypertension (n = 5, 24%), and angina abdominalis (n = 7, 33%). Most patients had multiorgan vascular disease such as iliofemoral arterial occlusive disease (n = 14, 66%), coronary artery obstruction (n = 8, 38%), or obstruction of the carotid artery (n = 6, 28%). Risk factors did not differ between coral reef patients and those with other occlusive vascular diseases. All patients were treated through vascular operations, including open thromboendarterectomy of the suprarenal (n = 9, 43%), infrarenal (n = 4, 19%), or supra- and infrarenal aorta (n = 8, 38%), and thromboendarterectomy of the following vessels: celiac artery (n = 7, 33%), superior mesenteric artery (n = 12, 57%), inferior mesenteric artery (n = 3, 14%), unilateral renal artery (n = 3, 14%), or bilateral renal artery (n = 9, 43%). Bypass reconstructions were performed in 39% (n = 8). A thoracoabdominal approach was used in 14 patients (67%) and a median laparotomy in 7 (33%). Our results show that coral reef aorta is not confined to either gender. It appears most frequently in the context of general atherosclerotic disease and patients benefit from timely diagnosis and operation before onset of severe, life-threatening visceral and renal complications.

Adult↗

Multivisceral fibromuscular dysplasia in childhood: case report and review of the literature.

We report here a 9-year-old girl with fibromuscular dysplasia of many muscular arteries including both renal and internal carotid arteries, the celiac artery, superior mesenteric artery, and one external carotid artery. She suffered from severe renovascular hypertension with beginning secondary cardiac decompensation, typical angina abdominalis, and neurological signs, including severe headaches and hemianopsia. Surgery was performed for all major vessels and the outcome is good 2.5 years after the operation. The clinical presentation, differential diagnosis, and treatment options of fibromuscular dysplasia in childhood are discussed and the literature is reviewed.

Child↗

Genetic factors determine extent of bone loss in inflammatory bowel disease.

BACKGROUND & AIMS: Although bone loss and osteoporosis are well-known long-term sequelae of inflammatory bowel disease (IBD), the risk factors for increased bone loss have not been identified. Balances of pro- and anti-inflammatory cytokines influence mechanisms of both chronic inflammation and bone resorption. The aim of this study was to identify genetic risk factors for rapid bone loss in IBD patients as a model of disease- and inflammation-associated bone loss. METHODS: Multiple clinical parameters, biochemical markers of bone metabolism (vitamin D, parathyroid hormone, N-terminal telopeptide of type-I collagen, desoxypyridinoline, bone alkaline phosphatase), and bone mineral density were prospectively assessed in 83 IBD patients over 1.6+/-0.3 years. Eighty-six healthy bone marrow donors served as controls for allelotyping. The allele status of the interleukin 1 receptor antagonist (IL-1ra), IL-6, heat shock protein 70-2 (hsp 70-2), and heat shock protein 70-hom (hsp hom) genes was typed and correlated with clinical course of IBD and extent of bone loss. RESULTS: The extent of bone loss was not correlated to clinical severity of disease or application of corticosteroids. Noncarriage of the 240-base pair allele of the IL-1ra gene and carriage of the 130-base pair allele of IL-6 were independently associated with increased bone loss. Genetic variations of the hsp genes were not associated with degree of bone loss. The combined presence of the named risk factors was significantly associated with increasing bone loss. CONCLUSIONS: Genetic variations in the IL-6 and IL-1ra gene identify IBD patients at risk for increased bone loss.

Absorptiometry, Photon↗

Sequence analysis of the MEN I gene in two patients with multiple cutaneous lipomas and endocrine tumors.

The discovery of mutations of the menin gene in a few multiple endocrine neoplasma type 1 (MEN I)-associated lipomas and loss of heterozygosity (LOH) on chromosome 11q13 in some sporadic lipomas has stimulated the hypothesis that lipomas may belong to the group of sporadic tumors caused by defects of the gene responsible for MEN I. Since it is unclear if the above hypothesis applies to all patients with lipoma or just to specific subsets, we searched to enlarge the database on this topic. For this purpose, we identified two patients with multiple cutaneous lipomas. One had an additional pituitary adenoma and familial presentation of multiple lipomas, the other had recurrent goiter in the setting of a family history of adenomatous goiter. Deoxyribonucleic acid (DNA) was analyzed by complete direct DNA sequencing of all coding exons and splice junctions of the MEN I gene. No mutation was identified in the coding exons of the menin gene. In contrast to former data on sporadic lipomas, these data are the first to render evidence that mutations of the MEN I gene may not be responsible for the formation of multiple lipomas, even if they appear in the context of other endocrine tumors.

Adenoma↗

Complete sequencing and mRNA expression analysis of the MEN-I gene in adrenal myelolipoma.

The molecular pathogenesis of adrenal myelolipoma is unclear. Endocrine activity of these tumors and association with other endocrine tumors have stimulated the hypothesis that it may belong to the group of sporadic tumors caused by defects of the gene responsible for multiple endocrine neoplasia type I (MEN-I). DNA of blood and tumoral sections from two patients with adrenal myelolipoma were analyzed by examination of variable number of tandem repeats (VNTR) loci PYGM, D11S987, D11S480, and D11S449 on chromosome 11q13 and by complete direct DNA sequencing of all coding exons and splice junctions of the MEN-I gene. Menin expression was examined by RT-PCR. RT-PCR did not detect menin expression in one adrenal myelolipoma. No loss of heterozygozity on chromosome 11q13 was identified. Intragenic heterozygozity was retained in codon 418 of the menin gene in both patients. No mutation was identified in the coding exons of the menin gene. Complete DNA sequencing yielded no hint that defects of the MEN-I gene are responsible for the formation of adrenal myelolipomas. Adrenal myelolipomas do not share the loss of heterozygozity on chromosome 11q13 observed in some benign adenomatous and many malignant adrenocortical tumors.

Adrenal Gland Neoplasms↗