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Biomedical subjects

P Kann

Publications and source records attributed to P Kann.

At least 19 recordsLinked to original sources
PubMed2006

Impact of environmental temperature on skin thickness and microvascular blood flow in subjects with and without diabetes.

BACKGROUND: Glucose measurement from different skin areas might be influenced by changes in skin texture due to several environmental confounders. Our study was performed to investigate the effect of changes in ambient temperature on skin thickness and microvascular skin blood flow in subjects with and without diabetes at the lower forearm. METHODS: Thirteen subjects with diabetes and seven without diabetes participated in the study. The investigations were performed in a temperature- and humidity-controlled climatic chamber (EMPA, St. Gallen, Switzerland). Starting at 25 degrees C, the environmental temperature was changed in 4 degrees C steps every 40 min. Skin thickness was measured by an ultrasonic reflection technique, and microcirculation was measured by laser Doppler fluxmetry at the lower forearm. Study participants underwent the entire procedure on up to four separate study trials. RESULTS: Our study revealed a significantly reduced skin thickness (P<0.05) and microvascular blood flow (P<0.05) in patients with diabetes mellitus compared with controls without diabetes during the entire investigation. During declining ambient temperature a significant reduction in skin thickness (with diabetes, -0.09+/-0.13 mm; without diabetes, -0.06+/-0.11 mm; P<0.05) and microvascular blood flow (with diabetes, -41+/-49 arbitrary units; without diabetes, -46+/-51 arbitrary units; P<0.05) could be observed in both groups without significant differences between the two. CONCLUSIONS: Although skin thickness and microvascular skin blood flow at the lower forearm were found to be reduced in patients with diabetes compared with controls without diabetes, both groups revealed comparable dynamics in skin thickness and microvascular blood flow during changes in environmental temperature.

Adult↗
PubMed2005

Pioglitazone decreases carotid intima-media thickness independently of glycemic control in patients with type 2 diabetes mellitus: results from a controlled randomized study.

BACKGROUND: Patients with type 2 diabetes mellitus are at high risk of cardiovascular disease. Carotid intima-media thickness (IMT) is a strong predictor of myocardial infarction and stroke. METHODS AND RESULTS: We compared the effects of pioglitazone-based therapy (45 mg/d) and glimepiride-based treatment (2.7+/-1.6 mg/d) for 12 and 24 weeks on metabolic control (HbA1c), insulin resistance (homeostasis model assessment), and carotid IMT (B-mode ultrasonography) in a randomized controlled study in 173 orally treated patients with type 2 diabetes (66 women, 107 men; mean+/-SD age, 62.6+/-7.9 years; body mass index, 31.8+/-4.6 kg/m2; HbA1c, 7.5+/-0.9%). Treatment was generally well tolerated in both groups. Despite similar improvements in metabolic control (HbA1c) after 24 weeks (-0.8+/-0.9% [pioglitazone] versus -0.6+/-0.8% [glimepiride]; P=NS), carotid IMT was reduced only in the pioglitazone group after 12 weeks (-0.033+/-0.052 versus -0.002+/-0.047 mm [glimepiride]; P<0.01 between groups) and 24 weeks (-0.054+/-0.059 versus -0.011+/-0.058 mm [glimepiride]; P<0.005 between groups). Insulin resistance was also improved only in the pioglitazone group (homeostasis model assessment, -2.2+/-3.4 versus -0.3+/-3.3; P<0.0001 between groups). Reduction of IMT correlated with improvement in insulin resistance (r=0.29, P<0.0005) and was independent of improvement in glycemic control (r=0.03, P=0.68). CONCLUSIONS: We found a substantial regression of carotid IMT, independent of improved glycemic control, after 12 and 24 weeks of pioglitazone treatment. This finding may have important prognostic implications for patients with type 2 diabetes mellitus.

Aged↗
PubMed2005

Pioneer study: PPARgamma activation results in overall improvement of clinical and metabolic markers associated with insulin resistance independent of long-term glucose control.

New scores and biochemical markers have recently been published for diagnosis of insulin resistance and beta-cell dysfunction (such as intact proinsulin, adiponectin, IRISII-score). One goal of this 6-month prospective controlled study was to evaluate the impact of pioglitazone (45 mg) vs. glimepiride (1-6 mg, in the intend to optimize therapy) on these markers. Observation parameters were: IRIS-II score, HOMA-score, ATP III score, HbA (1c), fasting glucose, lipids, intact proinsulin, adiponectin, and adverse events. The study was completed by 173 patients (66 female, 107 male, age +/- STD: 63 +/- 8 years, disease duration: 7.2 +/- 7.2 years, HbA (1c): 7.53 +/- 0.85 %, pioglitazone arm: 89 patients). The groups were not different for any of the observation parameters at baseline, and a similar reduction in HbA (1c) was seen in both groups (p < 0.001). In the pioglitazone group, reductions were observed for the IRIS-II and HOMA scores (p < 0.001 vs. glimepiride at endpoint) fasting glucose (p < 0.001), insulin (p < 0.001), LDL/HDL ratio (p < 0.001), hsCRP (p < 0.05), intact proinsulin (p < 0.001), and an increase was seen in HDL (p < 0.001), adiponectin (p < 0.001) and BMI (p < 0.001). In conclusion, treatment with pioglitazone resulted in an improvement of markers for insulin resistance and beta-cell dysfunction, independent from blood glucose control. Adiponectin, intact proinsulin, and the IRIS-II score may be suitable parameters for monitoring of these additional beneficial therapeutic effects.

Biomarkers↗
PubMed2004

[The choice between transperitoneal and retroperitoneal adrenalectomy. A prospective study].

INTRODUCTION: The aim of this prospective study was to evaluate the optimal surgical approach to endoscopic adrenalectomy. PATIENTS AND METHODS: Between March 1997 and February 2003, we performed 221 endoscopic adrenalectomies in 202 patients (right side 83, left side 100, bilateral 19), with an conversion rate of 2,5%. In 197 patients endoscopic adrenalectomy was carried out via retropertioneal approach 128 times and via transperitoneal approach 88 times. RESULTS: Endoscopic adrenalectomy was performed in 98% of the total number patients. No statistically significant influence ( P=0.05) was found for the parameters intraoperative blood loss, rate of postoperative complications, or duration of hospitalization in regard to the procedure. The operative time and learning curve were significantly longer with the retroperitoneal approach. Multivariate analysis identified surgical approach, tumor size (5 cm), and body mass index (25) as independent factors for operative time. CONCLUSION: The lateral transperitoneal approach is the optimal procedure for endoscopic adrenalectomy.

Adrenal Gland Neoplasms↗
PubMed2003

Size of pancreatic islets of Langerhans: a key parameter for viability after cryopreservation.

Large amounts and excellent viabilities of pancreatic islets are prerequisites for recent advances in islet transplantation. Cryopreservation has been shown to enlarge transplanted cell mass, but has been accompanied by reduced viability. In this study rat pancreatic islets were differentiated into small (<200 micro m), medium (200-400 micrometers) and large (>400 micrometers) categories and their susceptibilities to different freezing conditions were evaluated: concentration of cryoprotectant (0.7-3.1 M), equilibration (15 vs. 45 min, 22 degrees C vs. on ice) and post-thaw removal of cryoprotectant (15 vs. 30 min, stepwise vs. one-step). The most prominent finding was a negative correlation between islet size and viability observed in non-frozen islets to a minor degree (r=-0.44) and significantly enhanced after cryopreservation (r<-0.8). The concentration of cryoprotectant showed the most significant influence on viability affecting small, medium and large islets. Different techniques of equilibration with the cryoprotectant resulted in significant changes of islet viability of medium islets, whereas small and large islets were unaffected. For different techniques of removal of the cryoprotectant, no significant influence on viabilities was found. We conclude that large islets represented a highly susceptible population concerning damage due to cryopreservation.

Adenosine Triphosphate↗
PubMed2003

Oral administration of the growth hormone secretagogue NN703 in adult patients with growth hormone deficiency.

OBJECTIVE: Little is known of the usefulness of GH secretagogues (GHSs) in GH-deficient (GHD) adults. The objective of this study was to determine the number of responders to treatment with NN703 in GHD adults. DESIGN: A multicentre, randomized, double-blind, and placebo-controlled study. PATIENTS: Ninety-seven GHD adults were included. MEASUREMENTS: The GH response before and after 1 week of oral treatment with NN703 (n = 83) or placebo (n = 14) was determined. The first and last dose of NN703 was 3 mg/kg, whereas the dose of NN703 was 1.5 mg/kg/day during the 6 days between the first and last doses. Furthermore, all 97 patients received 1 micro g/kg GH-releasing hormone (GHRH) 3 weeks after the last dose of NN703. RESULTS: Serum GH peak and area under curve (AUC) values after the first NN703 administration were greater than those after placebo administration (P < 0.05). However, after correction for the lower body mass index (BMI) in the NN703 group, this difference lost statistical significance. After 1 week of therapy, GH peak and AUC values were similar following the final doses of NN703 and placebo. Serum peak and AUC values of other anterior pituitary hormones were similar between the NN703 and placebo groups both after the first and last administration of study drug. Nine of the 83 patients (11%) responded with a serum peak GH concentration >or= 5 micro g/l after the first and/or last NN703 administration, whereas no patient responded after placebo administration. Serum IGF-I was unaffected by 1-week NN703 treatment, whereas serum IGFBP-3 was increased (P < 0.05 vs. placebo) also after correction for BMI. Mean serum peak GH concentration after GHRH administration was 2.1 micro g/l (+/-0.3, SEM), which was higher than that after the first NN703 administration (1.32 +/- 0.3, P < 0.05). CONCLUSION: NN703 administration was generally well tolerated. Eleven per cent of the GHD adult patients responded with a peak GH response >or= 5 micro g/l after the first and/or last administration of oral NN703. Although a majority of GHD adults will not respond to NN703, the present results suggest that oral NN703 treatment could be useful in some adult patients with moderately severe GHD. These patients may be identified by a test dose of GHS.

Administration, Oral↗
PubMed2002

The collagen Ia1 SP1 polymorphism is associated with differences in ultrasound transmission velocity in the calcaneus in postmenopausal women.

Bone mineral density (BMD) and fracture risk are under genetic control. An association of a G to T polymorphism in the Sp1 binding site of the collagen Ia1 (COLIa1) gene with the risk for fractures has been previously reported. This association is only partly explained by differences in BMD. Thus, we analyzed the relationship between the COLIa1 Sp1 polymorphism and ultrasound (US) transmission velocity (speed of sound; SOS) in bone. In a population-based sample of 740 women (aged 55-80 years) we determined COLIa1 genotype and US parameters in the calcaneus. SOS in the "GG" genotype group was 1522 +/- 31 m/sec, in the "GT" group, 1519 +/- 30 m/sec, and in the "TT" group 1508 +/- 30 m/sec (P = 0.01). While the difference between the GG and TT genotype groups corresponds to 0.5 SD or 1%, we observed an allele-dose-effect of 4.3 m/sec decrease in SOS per each copy of the "T" allele (P = 0.01). The differences remained significant after adjustment for BMD measured at the femoral neck. When we analysed 45 incident nonvertebral fractures in this group of women, we found the risk for fracture by COLIA1 Sp1 genotype to be partly explained by SOS differences as well as by BMD differences. Linear regression analysis showed a progressive negative slope of the regression line of SOS over age from "GG" over "GT" to "TT" genotype. These data indicate that the collagen Ia1 Sp1 polymorphism is associated with the modulus of elasticity of bone as determined in vivo by acoustical measurement. The relationship is independent of BMD and increases with age, contributing to an explanation of the increased fracture risk observed for this polymorphism.

Aged↗
PubMed2002

[Cushing's syndrome caused by paraneoplastic ACTH secretion 11 years after occurence of a medullary thyroid carcinoma].

HISTORY AND ADMISSION FINDINGS: A 47-year-old man, with known and treated hypertension for 2 years, was admitted because of recent marked weight gain. Eleven years before a medullary thyroid carcinoma had necessitated removal of his thyroid and parathyroids. He was not receiving levothyroxine, calcium and vitamin D. Physical examination revealed florid Cushing's syndrome with a "buffalo hump", plethora, truncal obesity and red striae. Both his mother and a maternal male cousin were reported to have had a medullary thyroid carcinoma. INVESTIGATIONS: Plasma ACTH was 80 pg/ml (normal 10-70 pg/ml), urinary cortisol 764 microgram/24 h (normal 20-100 microgram/24 h). ACTH rose to 93.1 pg/ml after dexamethasone, with little suppression of serum cortisol (reduced from 34.4 to 22.1 microgram/dl; normal 7-25 microgram/dl. Magnetic resonance imaging did not detected an abnormal hypophysis. Petrosal sinus catheterization revealed hypophyseal suppression of ACTH, without evidence of focal peripheral ACTH production. Calcitonin was 24 000 pg/ml (normal < 8.8 pg/ml). Computed tomography showed multiple round lesions in the liver (histology: metastasis of a C-cell carcinoma). Genetic test showed a multiple endocrine neoplasm type IIa. DIAGNOSIS, TREATMENT AND COURSE: The findings indicated Cushing's syndrome, most likely due to paraneoplastic ACTH secretion from a metastasis of the C-cell carcinoma. In the absence of a site of paraneoplastic ACTH secretion, bilateral adrenalectomy was performed. The plethora and striae regressed postoperatively and it was possible to reduce markedly the antihypertensive medication. CONCLUSION: An ectopic site of ACTH should be included in the differential diagnosis of Cushing's syndrome. This is the first reported case of a medullary thyroid carcinoma and ectopic ACTH production in which the paraneoplastic ACTH secretion had been delayed for 11 years.

Adrenalectomy↗
PubMed2002

Abnormal pentagastrin response in a patient with pseudohypoparathyroidism.

The case of a 25 year old female patient with pseudohypoparathyroidism type I (PHP) and hypercalcitoninaemia is reported. She was referred to our clinic because of recurrent hypocalcaemia associated with paraesthesias and muscle cramps. She had no signs of Albright hereditary osteodystrophy (AHO), a normal mental status and no family history of hypocalcaemia or any other endocrine disease. Considering the laboratory results with hypocalcaemia, hyperphosphataemia, normal vitamin D and normal creatinine with an extraordinary elevated PTH we diagnosed pseudohypoparathyroidism type I. She had delayed pubertal development with menarche in the age of 20 and hypothyroidism with an atrophic thyroid since she was 22 years old. Calcitonin (CT) was increased and the performed pentagastrin test showed an excessive CT-response with a peak of 725 pg/ml after 2 min. Up to now there are only three reports of patients with PHP and hypercalcitoninaemia. An abnormal pentagastrin response is known to be a specific marker for medullary thyroid carcinoma, but there were no signs of any malignant disease, even after one year of follow-up. The most reasonable cause for the pathological pentagastrin response might be chronic hypocalcaemia. When interpreting a pathological pentagastrin test in a patient with PHP the specifity of the test might be diminished and a careful observational strategy might be appropriate.

Adult↗
PubMed2002

Determination of the modulus of elasticity of bone material by an acoustical approach at the forearm distinguishes women with and without vertebral fractures independent of bone mineral density.

The modulus of elasticity is a parameter characterizing fracture stability of bone independent of bone mineral density. Measurement of acoustical properties of the forearm by determination of the resonant frequency of the ulna in longitudinal direction as a function of sound transmission velocity after adjustment of the measuring result by ulna length yields information about the modulus of elasticity. It was the aim of this study to investigate whether this parameter may distinguish between subjects with and without vertebral fractures independent of bone mineral density. Fifty females (61.1 +/- 9.1 years) were enrolled into the study, 25 with, and 25 age-matched without prevalent osteoporotic vertebral fracture(s). Especially low bone mineral density was not considered an exclusion criteria for enrollment into the control group. Resonant frequency of the ulna multiplied by ulna length was significantly lower in the group with prevalent fractures (53.6 +/- 6.8 m/s versus 56.8 +/- 5.2 m/s) after adjustment for age and after additional adjustment for forearm bone mineral density. Linear regression analysis showed complete independence of the acoustical parameter from bone mineral density. This study demonstrates that the modulus of elasticity of bone material is an independent risk factor for osteoporotic fractures. Acoustical measurement at the forearm by analyzing the resonant frequency of the ulna and correcting it by ulna length as geometrical parameter is capable of determining the modulus of elasticity in vivo.

Acoustics↗
PubMed2001

Endosonography of insulin-secreting and clinically non-functioning neuroendocrine tumors of the pancreas: criteria for benignancy and malignancy.

OBJECTIVE: Endosonography is a powerful tool in the diagnosis of gastroenteropancreatic neuroendocrine tumors. This study was performed in order to characterize endosonographic criteria of malignant and benign neuroendocrine pancreatic tumors focussing on those typically presented to endocrinologists, i.e. insulin-secreting tumors and clinically non-functioning tumors in MEN-1. DESIGN: We studied six benign insulinomas, four hormone inactive benign neuroendocrine adenomas in MEN-1, and three non-metastatic neuroendocrine carcinomas with clinically symptomatic insulin secretion. METHODS: Endosonography was performed using Pentax FG 32 UA endosonoscope with a longitudinal 7.5 MHz sector array. RESULTS: Tumor diameter was larger in malignant tumors (19 - 70 / 47.0 +/- 25.9 mm) than in benign lesions (2.3 - 19 / 9.7 +/- 5.8 mm). Hypoechoic echogeneity was more or less present in benign and in malignant tumors and could not be used as a criteria for differential diagnosis. Heterogeneous or multinodular structure on endosonographic imaging however, was an exclusive feature of malignant tumors. Echo-free areas representing cystic transformation or necrosis and vascular invasion were additional signs of malignancy. CONCLUSIONS: Molecular genetic diagnosis of MEN-1 and new therapeutic developments such as endoscopic surgery make sufficient imaging procedures in the management of neuroendocrine pancreatic tumors mandatory. Besides valid detection and exact localization, endosonography provides criteria for benign and malignant tumors and thus may be helpful in planning therapeutic strategies.

Carcinoma, Neuroendocrine↗
PubMed2001

Speed of sound measurements in mandibular and phalangeal bone during growth.

The micromechanical and elastic properties of bone, its structural maturity and, indirectly, mineral density are important factors for the planning and assessment of orthodontic and/or jaw orthopaedic treatment. This clinical study was undertaken to evaluate age-related changes in the anterior mandibular body. The speed of sound (SOS) has demonstrated age dependency in various peripheral bones and has been proposed as an alternative method for investigating bone parameters without the use of radiation. The ultrasound transmission velocity was measured in 184 healthy subjects (93 females, 91 males; mean age 17.6 +/- 13.7 years). According to the statistical analysis, the data did not reveal any gender-related differences, but were significantly age-dependent. Different kinetics were established between the maturity of the phalanx and the anterior mandible. Further clinical investigations of age-dependent structural changes in bone maturation parameters may provide information that should be taken into account for early functional jaw orthopaedic treatment.

Adolescent↗
PubMed2001

Suppressed levels of serum cortisol following high-dose oral dexamethasone administration differ between healthy postmenopausal females and patients with established primary vertebral osteoporosis.

Hypercortisolism and glucocorticoid treatment, even in a low dose or administered topically, may influence bone metabolism. It was the aim of this study to investigate whether there might be differences in the regulation of endogenous cortisol secretion between patients with established primary vertebral osteoporosis and healthy controls. Suppressed morning serum cortisol concentrations in a 3 mg dexamethasone overnight suppression test were compared in well-defined healthy postmenopausal women (n = 149) and osteoporotic patients classified as having established primary vertebral osteoporosis with no clinical features of hypercortisolism (n = 78). Suppressed cortisol in the healthy controls was 1.08 +/- 0.44 microg/dl and in the primary osteoporotics 1.58 +/- 1.42 microg/dl (p < 0.0001). Of the investigated primary osteoporotics 15.4% (n = 12) had suppressed cortisol levels above the 97.5th percentile (1.96 microg/dl) of the healthy controls. Subgroup analysis regarding the influence of gonadal steroid hormone replacement in both groups and gender in the osteoporotic group did not change the results. Four of the 12 patients with incomplete suppressive cortisol underwent adrenal endosonography, unilateral adrenal nodular hyperplasia being detected in three cases. In two patients the diagnosis was confirmed by histology and normalisation of a dexamethasone suppression test following endoscopic adrenalectomy. These data yield evidence for a difference in the regulation of cortisol secretion following high-dose dexamethasone administration between healthy subjects and a subgroup of patients with primary osteoporosis. This might be due to a relevant amount of autonomous cortisol secretion in some of these patients; however, even cortisol resistance has to be taken into account.

Aged↗
PubMed2000

[Comparison of hypoglycemia perception and hormonal counterregulation in controlled hypoglycemia. A contribution to diagnosis of hypoglycemia unawareness syndrome in type 1 diabetic patients].

BACKGROUND AND OBJECTIVE: Diabetics with abnormal hypoglycaemia awareness cannot recognize hypoglycaemic symptoms early and adequately enough to respond, thus endangering in everyday life not only themselves but also others. Thus it is important to diagnose such symptoms early and assess the extent to which the diabetic is at risk of severe hypoglycaemia. This study was designed to contribute to the evaluation of hypoglycaemia awareness in type 1 (IDDM) diabetics. PATIENTS AND METHODS: In 57 diabetics (IDDM) awareness of typical hypoglycaemic warning symptoms and of hormonal counterregulation were tested during controlled induced hypoglycaemia. A questionnaire was used to measure at fixed time intervals, along a four-point scale, the severity of 6 autonomic and 6 cerebral warning symptoms, and compare them with synchronously obtained plasma levels of glucagon and epinephrine. RESULTS: The cohort was divided into three groups according to the rise of epinephrine levels induced by the hypoglycaemia. Group A (n = 22) showed a significant rise in epinephrine level at the onset of hypoglycaemia; group B (n = 22): significantly increased epinephrine only after 30 min of hypoglycaemia; group C (n = 15): no epinephrine rise at any time during hypoglycaemia. None of the patients had a significant rise in glucagon levels. There were significant differences between the three groups regarding HbA1c levels and the duration of diabetes. Low levels of HbA1c and duration of diabetes were commonly associated with a loss of hormonal counterregulation. In only 40% of patients was it possible to draw any conclusion about epinephrine-induced hypoglycaemia from symptoms revealed in the past history. CONCLUSIONS: The past history of hypoglycaemic symptoms is an unreliable and inadequate guide for objectively assessing the actual risk of hypoglycaemia in type 1 diabetics. The results of this study indicate that when severe hypoglycaemic attacks (requiring outside help etc.) are suspected, standardized diagnostic tests of hypoglycaemia awareness should be performed in specialized centres, particularly if an official medical report ist required.

Adult↗
PubMed2000

[Predictive genetic investigations. Individualization of diagnosis and treatment in families with multiple endocrine neoplasia type II].

BACKGROUND AND OBJECTIVE: When multiple endocrine neoplasia type 2 (MEN2) is suspected, genetic tests are at the centre of screening procedures. It was the aim of this study to compare the diagnostic value of molecular biological investigations with that of conventional biochemical tests. PATIENTS AND METHODS: The study cohort consisted of all 144 patients cared for in our department since 1990 with the suspected diagnosis of MEN2 (evidence of a medullary thyroid carcinoma [MTC]), coexistence of two MEN2 tumours or a family history of MEN2. 14 of the 144 patients (from 12 families) were already known to have an hereditary MTC, while the remaining 130 had been referred for further diagnostic investigations. RESULTS: An hereditary MTC was diagnosed in 22 of the 130 patients, a sporadic MTC in 32, while no definitive classification was possible in 20 MTC patients without a positive family history and on whom no mutation analysis had been performed. MEN2 was excluded in 56 family members. All 22 patients with newly diagnosed MTC had abnormally high calcitonin levels. A germ-line mutation in the RET proto-oncogene was found in 8 of the 9 families who had undergone molecular biological tests. The investigate results led to a thyroidectomy in 19 of the 22 patients with hereditary MTC; in all of them the surgical specimen showed C-cell hyperplasia and/o MTC. CONCLUSION: These results emphasize the importance of genetic tests in family screening. Preoperative measurement of calcitonin remains essential in MEN2 families in whom a germ-line mutation is not known. The choice of the appropriate diagnostic test must be individualized to the particular patients so that optimal results are obtained.

Adolescent↗
PubMed2000

Using ultrasound transmission velocity to analyse the mechanical properties of teeth after in vitro, in situ, and in vivo irradiation.

Ultrasound transmission velocity (UTV) in isotropic material as a measure for the modulus of elasticity was correlated to mechanical properties. Changes in micromechanical properties of radiated teeth and influence of the oral cavity were to be evaluated nondestructively. UTV was measured in extracted teeth after 36 Gy and 62 Gy of in situ (enorally, with no contact to the oral cavity) and in vitro irradiation. Relative to controls, teeth subjected to 62 Gy in vivo showed higher UTV values for dentine and enamel. Sound teeth irradiated with 60 Gy in situ also showed higher UTV values for enamel, whereas dentine values were not significantly different from those of control. The mechanical properties of teeth irradiated in vitro were affected only after high experimental doses of up to 500 Gy. The difference between in vivo and in vitro mechanical properties may be due to radioxerostomia-induced damages as well as the status of dentine vitality. This supports the concept of direct radiation-induced damage in synergy with radioxerostomia-induced caries.

Cranial Irradiation↗
PubMed2000

Comparison of immunoassays for the detection of anti-GAD65 autoantibodies in patients with diabetes mellitus.

Recent studies have demonstrated that a combination of GAD-antibody assays and IA-2 autoantibody assays show a high diagnostic specificity for Type 1 diabetes. For this reason there is increasing interest in the use of GAD-antibody measurement for Type 1 risk assessment. Since a number of different assays have been published and documented in the literature, the aim of this study was to evaluate four different anti-GAD test systems that are commercially available in Germany. We tested the anti-GAD prevalences in five patient groups with the different immunoassays and compared them with the values obtained by an immunoprecipitation test (IP-Test). All assays correlated well with the IP-test and showed high sensitivity and specificity in the group of patients with recent onset Type 1 diabetes and the control group. The groups tested consisted of 20 subjects with recent onset Type 1 diabetes (< 6 weeks) (sensitivity 70-90%), nine subjects with a Type 1 duration of more than 2 years (sensitivity 11-33%), 21 patients with pluriglandular insufficiency (sensitivity 28.5-47.5%), 10 patients with Type 2 (specificity: 90-100%), and 14 healthy control subjects (specificity: 93-100%). Our data show a high level of sensitivity and specificity of the tested, commercially available, assays. Since almost every laboratory should be able to establish one of these assays, this may facilitate the possibility of further large scale population studies with the aim of investigating GAD-antibody prevalences in screening for Type 1 diabetes. Increased measurement of the diabetes-associated antibodies will be helpful in the differential diagnosis of gestational diabetes mellitus (GDM) and latent autoimmune diabetes of the adult (LADA).

Adolescent↗