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Biomedical subjects

K Federlin

Publications and source records attributed to K Federlin.

At least 37 records · Page 2Linked to original sources

Bone metabolism and bone mineral density of systemic lupus erythematosus at the time of diagnosis.

Recent studies have shown that systemic lupus erythematosus (SLE) is associated with a loss of trabecular bone. However, these changes have not been not described in patients with SLE at the time of diagnosis. To investigate the markers of bone metabolism 20 female patients with a recently manifested clinical picture of SLE were selected. All patients included in this study met the ARA criteria (for classification) of SLE. For comparison, 35 female patients with SLE, which had previously manifested itself and which had been treated with glucocorticoids, were included in a second group. A control group (III) consisting of 20 healthy individuals of the same age was formed to compare the results obtained. Test parameters comprised both serum levels of osteocalcin (OC) as the marker for bone formation and crosslinks excretion (CE) in urine as a specific marker for bone resorption. The bone density (BMD) was examined by dual energy X-ray absorption (DEXA) of the vertebral column (L2-L4), femoral neck, Ward's triangle and trochanter. The patients under study received either no medication or nonsteroidal antirheumatic drugs. The BMD of the vertebral column was significantly lower than expected in SLE-afflicted subjects of group II when compared with the age-matched normal female controls. The reduction of BMD in female patients with SLE was related to the significantly increased excretion of urinary pyridinoline, to hypoparathyroidism, and to the decrease in serum OC. Bone loss in women with fresh manifestation of SLE (I) increases to a degree similar to that of patients in group II. Lowered BMD predicts an increased risk for bone fractures. Therefore, female premenopausal SLE patients should be monitored for osteoporosis.

Absorptiometry, Photon↗

The Giessen-Bad Oeynhausen family study: improved prediction of type I diabetes in a low incidence population of relatives using combinations of islet autoantibodies in a dual step model.

To determine the value of a combined antibody screening for prediction of type I diabetes in a low incidence cohort, we prospectively studied 882 first-degree relatives (485 parents, 382 siblings and 15 offsprings) for up to 11 years who were not preselected for islet cell antibody (ICA) status. During the observation period, 16 individuals developed diabetes. The first serum sample obtained at study entry was analyzed for ICA and antibodies to insulin (IAA), glutamic acid decarboxylase (GADA) and anti-IA-2ic. A multivariate analysis, according to the Cox proportional hazard model considering the joint effects of all baseline variables, selected the four antibodies and the specific family history as significant risk confounding factors (p < 0.05). Further analysis by Kaplan-Meier Life-table methods confirmed a significantly increasing risk of diabetes with the number of autoantibodies present (p < 0.001). In accordance with the Cox model, relatives with more than one affected family member (a multiplex pedigree) and siblings and offsprings vs. parents were at increased risk of IDDM (p < 0.05). In addition to technical problems, a screening strategy based on initial ICA testing has the potential of missing ICA negative subjects among future cases of type I diabetes (19% were ICA negative in the present study) and we therefore set out to evaluate an alternative approach using a dual step strategy with a combination of GADA and anti-IA-2ic for initial screening followed by retesting of positive individuals for ICA and IAA. The combination of GADA and anti-IA-2ic for primary screening (step 1) proved to be more sensitive, identifying 94% of future cases of type I diabetes compared to 81% using ICA as initial test and this antibody combination identified 93% of those individuals with ICA of 20 JDF or more. Retesting of positive individuals for ICA and IAA (step 2) significantly improved the positive predictive value confering a risk of diabetes for siblings and offsprings with more than 2 antibodies within 5 years of 67% (95%CI: 39-90). We conclude that the prognosis of contracting IDDM in relatives is strongly related to the number of autoantibodies present, but the family history should be additionally considered for individual risk assessment. The proposed screening strategy could overcome the inherent problems of the ICA and IAA assays for large-scale screening. In the present study it allows 5-year risk estimates of up to 67% identifying 94% of future cases of type I diabetes.

Adult↗

The combination of antibodies to GAD-65 and IA-2ic can replace the islet-cell antibody assay to identify subjects at risk of type 1 diabetes mellitus.

First-degree relatives of type 1 diabetic patients are at increased risk of developing diabetes and, until recently, islet cell antibodies (ICA) have represented the major risk marker used for identification of individuals at increased risk for subsequent progression to diabetes. In order to determine the value of antibodies to GAD-65 and IA-2ic to identify individuals at high risk for type 1 diabetes mellitus, we measured both autoantibodies and ICA in 1436 first-degree relatives of patients with type 1 diabetes. In addition, the sera were analyzed for thyroid, adrenal and gastric-parietal cell autoantibodies as markers for possible polyendocrine involvement. GAD-65 Abs were found in 135 out of 1436 (9.4%) first-degree relatives and in 57 of 98 (58.2%) ICA-positive subjects. IA-2ic were detected in 52 of 1436 (3.6%) first-degree relatives and in 44 of 98 (44.8%) ICA-positive relatives. IA-2ic and/or GAD-65 were detected in 73 of 98 (74.5%) ICA-positive relatives. Interestingly, antibodies to GAD-65 and/or IA-2ic were present in 91.2% of individuals with more than 20JDF-units. Anti-IA-2ic and GAD-65 were positively correlated with high levels of ICA. Anti-IA-2ic and GAD-65 were found in 19% and 48.5% of subjects with ICA levels of 5-20JDF-u but in 68.8% and 76.5% of individuals with ICA of 40JDF-u or more, respectively (p < 0.001), compared to subjects with ICA levels less than 5 JDF-u. When autoantibody frequencies among the relatives were analyzed according to relationship to the proband, the offspring and siblings had a higher frequency of ICA and IA-2ic (p<0.05) than the subgroup of parents. A significant association was observed between IA-2ic and thyroid antibodies. In addition, higher levels of IA-2ic were found in relatives with positive TPO antibodies (p < 0.001); this correlation was particularly strong in offspring and siblings (p < 0.01). Determination of GAD-65 and IA-2ic antibodies may be considered as an alternative to primary ICA-screening, enabling the screening of large populations.

Adolescent↗

Evaluation of serum and urinary estrogen levels in male patients with HIV-infection.

Several endocrine functions are described which are altered in patients with human immunodeficiency virus infection. However, there is limited information available on estrogens and their function in these patients. The aim of this study was to relate the stage of the disease with urinary and serum estrogens and the influence of heroin consumption on gonadal steroids. Forty human immunodeficiency virus infected outpatients without AIDS or the clinical picture of AIDS were involved in this cross-sectional study. The subjects were divided in two groups: heroin addicts and non heroin addicts. Blood samples were taken and 24 h urines collected. Serum follicle stimulating hormone, luteinizing hormone, prolactin, estrone, estradiol, testosterone and urinary total estrogens were measured by commercially available radioimmunoassays. Prolactin levels were not affected in the patients. However, compared with controls, follicle stimulating hormone and luteinizing hormone were significantly higher for both groups tested. In contrast, the elevated serum estrone levels were significantly lower expressed in the patients with heroin abuse compared to those of the other group. Urinary estrogens in human immunodeficiency virus infected patients of both groups were found to be higher than those compared to healthy controls. Since these drugs are known to enhance estrogen levels, we conclude that other factors are modulating estrogen formation and degradation in these patients.

Adult↗

Improved glucose counterregulation and autonomic symptoms after intraportal islet transplants alone in patients with long-standing type I diabetes mellitus.

BACKGROUND: Defective glucose counterregulation and hypoglycemia unawareness are both well-recognized risk factors for recurrent episodes of severe hypoglycemia in patients with type I diabetes. At present, no conventional therapy is available to routinely overcome these acquired impairments in long-standing diabetes. METHODS: To test the hypothesis that successful intraportal islet transplantation could improve this syndrome, hormonal counterregulatory responses and symptoms were studied during stepped hypoglycemic clamp tests before and after intraportal islet transplantation in three patients with type I diabetes who were prone to severe hypoglycemia. RESULTS: As compared with matched nondiabetic control subjects, before islet transplantation, glucagon responses were absent while epinephrine and cortisol responses were either markedly decreased or absent in all diabetic subjects. One patient also had decreased norepinephrine and growth hormone responses. Autonomic warning symptoms were absent in all patients during hypoglycemia. One month after successful islet transplantation, there was no improvement in the glucagon response. However, glycemic thresholds and/or peak incremental responses of epinephrine, norepinephrine, and cortisol improved in all patients. Moreover, all patients had developed autonomic warning symptoms so that glycemic thresholds were detectable within the examined range. CONCLUSION: We conclude that intraportal islet transplantation does not restore hypoglycemia-induced glucagon secretion, but it improves the responses of most counterregulatory hormones and hypoglycemic warning symptoms even in long-standing type I diabetes.

Adult↗

Adhesion molecules and microvascular changes in the nonobese diabetic (NOD) mouse pancreas. An NO-inhibitor (L-NAME) is unable to block adhesion inflammation-induced activation.

The aim of the present study was to investigate the immunoreactivity of pancreatic microvasculature with emphasis on the adhesion molecule expression in NOD mice at a very early stage and after the start of infiltration, before the onset of the diabetic disease. Immunoreactivity for Ia-b, BM8 (mouse macrophages) and inter-cellular-adhesion-molecule-1 (ICAM-1) molecules in untreated control mice and in animals treated using an inhibitor of nitric oxide (NO) formation (L-arginine analogue), as well as islet culture, nitrite assay and ultrastructural studies were performed. Results showed that Ia-b and ICAM-1 immunoreactivities on endothelia are a very early phenomenon and that pancreatic blood vessels and, in particular, some peri-islet venules, as well as several venules of the exocrine parenchyma, undergo significant morphological changes. Several endothelial cells of both peri-islet and extra-islet compartments, often showed Ia-b and ICAM-1 immunoreactivities, demonstrating that these cells are important for the adhesion processes taking place during early autoimmune inflammation. Inhibition of NO formation does not significantly affect ICAM-1 and Ia-b immunoreactivity both in vivo and in vitro, BM8 immunoreactive cells were considerably less in number although these were detected either around islets or along pancreatic septa, but rarely within the epithelial layer.

Animals↗

Alginate-based microcapsules for immunoprotected islet transplantation.

Islet transplantation is a promising therapeutic approach for the treatment of insulin-dependent diabetes mellitus. Nevertheless, its broader clinical use is hampered by the shortage of human organ donors as well as the need for a permanent immunosuppressive drug therapy in order to avoid rejection. Microencapsulation shall help to overcome this problem by creating an immunoprotected transplantation site. Biocompatibility of the encapsulation material and the possible immuno-interaction of the grafted tissue and the host immune system need to be examined very carefully. In transplantation experiments, we could show that the long-term function of the graft is dependent on the species of the islet donor, indicating that there has to be a recognition of the encapsulated islet despite the encapsulation membrane. This could be confirmed by in vitro data in the mixed lymphocyte islet culture (MLIC). Moreover, morphological studies of the tissue reaction toward encapsulated syngeneic vs. allogeneic vs. xenogeneic encapsulated islets reveal that the greater the difference between donor and recipient species the greater the amount of fibrous tissue formation. Thus, for the outcome of transplantation experiments, not only the material-related biocompatibility but as well the reaction towards the whole device (consisting of the capsule plus the encapsulated tissue) are crucial. Therefore, immunoprotection does not only comprise the protection of the grafted tissue from the host immune effector mechanisms but as well the inhibition of the recognition of the graft by the host immune system.

Alginates↗

Elevated serum-calcium and parathormone-levels in HIV afflicted female heroin addicts.

Alterations of calcium and bone metabolisms have been observed in numerous studies of small groups of male HIV-infected patients. However, our knowledge regarding the manifestation of AIDS-associated hypoparathyroidism in female subjects is limited. In order to investigate the influence of heroin on the calciotropic hormones we performed a cross-sectional study on 45 female patients with proven HIV infection. The following criteria were used for exclusion from the study: age less than 20/ more than 50 years; confinement to bed; wasting symptoms; treatment with agents containing ketoconazole, renal or hepatic insufficiency; clinical or echographic signs of liver cirrhosis; endocrine diseases, or treatment with drugs known to influence calcium metabolism. A reduced parathormone (PTH) level was found among the female HIV-infected patients. Additional long-term use of heroin resulted in a significant increase of PTH compared to sex- and age matched controls and a second group of non-HIV-afflicted heroin dependent females. Significantly lowered serum magnesium concentrations were found in all three groups. Both serum calcium and urinary excretion of calcium were elevated in the group of HIV-infected heroin addicts and were independent from low vitamin D3 levels (1,25-dihydroxycholecalciferol) and alterations of protein metabolism. Therefore, it is concluded that the changes of PTH secretion are mainly due to mechanisms both of the impaired immune defense of HIV-infected females and the additional effect of opiates.

Adult↗

[Late diabetic sequelae].

Diabetic patients are exposed to higher risk of morbidity and mortality. However, it is difficult to define this in advance and to predict the degree of inability for work. The risk is depending on type of diabetes, age of manifestation, age of the patient course and duration of the disease and mainly from glycemic control. Educational programs may markedly ameliorate the overall situation and decrease of risk of late complications which may threat kidney, eyes, nerves and the cardiovascular system. However, it is an erroneus notion that most diabetics may be crippled by complications of their disease which may result in unwarranted bias against them in both work and leisure activities. Most diabetics may undertake any occupation or hobby, of course with some exceptions when hypoglycemia due to insulin or hypoglycemic agents represents risk for themselves and other persons. Those patients may not serve as pilots and cannot hold public service vehicle driving licences. They should not take over the supervision in power-stations etc. Ordinary driving licences can be held by diabetic patients if on insulin or not, provided that they are otherwise physically fit and do not suffer from blackouts. From many studies it is known that the rate of accidents is not higher with respect to diabetic patients than in the normal population. Life assurance premiums are often raised by amounts which depend on the result of a medical examination but it is very important that the judgement is not made on the basis of a single checkup at a given time. To get information about the presence or development of late complications which have a very broad spectrum it is necessary to have insight into the course of the metabolic disorder and the tendency of worsening or amelioration.

Cause of Death↗

Rapid spinal trabecular bone loss in female patients with ileitis terminalis Crohn and additional sacroiliac joint inflammation.

Patients with Crohn's disease are well known to have local and generalized osteopenia of varying degrees. The aim of this study was to investigate whether the additional involvement of the sacroiliac joint as an extraintestinal manifestation has an influence on bone turnover in female patients with Crohn's disease. Osteocalcin and other parameters of bone metabolism were measured in 79 female patients with Crohn's disease. Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry (DEXA). Z scores were obtained by comparison with age- and sex-matched normal values. As regards the sacroiliac involvement (n = 26; group 1), we found a significantly lower BMD in the lumbar spine (L4) and in Ward's triangle of the femoral neck compared to controls (P < 0.05) and those patients (n = 53; group 2) with pure ileitis terminalis Crohn. Furthermore, the duration of the disease process in patients with Crohn's disease and extraintestinal involvement was markedly shorter than that of patients in group 2 (P < 0.05). In conclusion, osteoporosis in female patients with sacroiliac involvement manifested itself in a more severe way.

Adult↗