Trabecular bone quality is lower in adults with type 1 diabetes and is negatively associated with insulin resistance.

We evaluated trabecular bone score (TBS) and factors affecting TBS in adults with type 1 diabetes (T1D) compared to age-, sex-, and body mass index (BMI)-matched adults without diabetes. Adults with T1D had lower TBS compared to controls. Abdominal obesity and insulin resistance are associated with lower TBS. INTRODUCTION: We evaluated TBS, a non-invasive method to evaluate trabecular bone quality at the lumbar spine, in adults with T1D compared to age-, sex-, and BMI-matched adults without diabetes. METHODS: We calculated TBS from adults with T1D (n = 47) and controls (n = 47) who had a lumbar spine dual x-ray absorptiometry (DXA) at their third visit (2006-2009) of the ongoing "Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study." The linear relationships of TBS and bone mineral density (BMD) with hemoglobin A1c, blood pressure, lipids, and insulin resistance were evaluated using Pearson's correlation coefficient. Multiple linear regression was used to test the association of TBS with sex and diabetes while adjusting for other potential confounders. RESULTS: TBS was significantly lower in adults with T1D compared to controls (1.42 ± 0.12 vs 1.44 ± 0.08, p = 0.02) after adjusting for age, sex, current smoking status, and lumbar spine BMD, despite no difference in lumbar spine BMD between the groups. Components of the metabolic syndrome, including diastolic blood pressure, BMI, triglycerides, and insulin resistance were negatively correlated with TBS among patients with T1D. CONCLUSION: Trabecular bone score, an indirect measurement of trabecular bone quality, was lower in adults with T1D compared to controls. Components of metabolic syndrome and insulin resistance were associated with lower TBS in adults with T1D.

Have rates of erectile dysfunction improved within the past 17 years after radical prostatectomy? A systematic analysis of the control arms of prospective randomized trials on penile rehabilitation.

Based on case series, potency rates after radical prostatectomy (RPE) differ substantially and - furthermore - it remains unclear whether they have improved in more recent surgical series. The purpose of this study was to investigate whether potency rates after RPE have improved over the years. A systematic analysis of the control arms of all randomized controlled trials (RCT; n = 11) on penile rehabilitation after RPE was carried out. In total, 2009 patients were included in these RCTs, 685 thereof in the respective control arms, who were either observed or received placebo. Assessment of erectile function in these studies was carried out by the Sexual Encounter Profile (SEP) or the International Index of Erectile Function (IIEF). Eight trials used SEP3 as study endpoint. The rate of positive response to SEP3 (=erectile function sufficient for successful intercourse) in the control arms was 20% in 1997 (year of publication), 10% in 2003, 19% in 2004, 25% in 2008, 21% in 2010, 67% in 2011, 10% in 2013, and 22% in 2014. Eight RCTs assessed the IIEF-EF, yet results were not reported uniformly. In the control arms the IIEF-EF was 9.2 (year of publication 2003), 13.3 (2004), 8.8 (2008), 25% ≥22.0 (2008), 17.4 (2010), 58% ≥26.0 (2011), 9.3 (2013), and 11.6 (2014). Limitations of this analysis are a positive selection bias regarding patient recruitment, surgical approach, and the non-uniform inclusion and outcome criteria. This systematic analysis of the control arms of all RCTs on penile rehabilitation after nerve-sparing RPE shows (i) that the rate of undisturbed erectile function is in the range 20-25% in most studies and (ii) that these rates have not substantially improved or changed over the past 17 years.

European proficiency study with control serum for the tumor marker CA 19-9 measured on different test systems.

BACKGROUND: Reliable and precise CA 19-9 testing is required for the long-term follow-up of patients with pancreatic carcinoma during therapy. The aim of this longitudinal proficiency study was to evaluate the comparability, linearity, and precision of CA 19-9 determinations performed in different laboratories using currently available test systems under routine conditions. METHODS: During the one year study period, 15 laboratories applied 7 different tests and included a liquid BIOREF control serum with pancreatic carcinoma derived CA 19-9 in their routine testing and quality control procedures. The results were collected centrally and evaluated statistically. RESULTS: The comparability of CA 19-9 results is limited especially when different tests are used, albeit, some tests show a good correlation: The CA 19-9 values obtained by different laboratories using different test systems vary up to a factor of 2. The precision of CA 19-9 determinations was acceptable in most laboratories with coefficients of variation ranging between very low 3.2% and high 17.8%. The imprecision was slightly increased when automatic dilution procedures of the analysers were used. CONCLUSIONS: The comparability of CA 19-9 test results must be improved. The precision is acceptable in most cases. In order to monitor key performance parameters, every laboratory should participate in external quality assessment schemes and should perform a routine internal quality control with a control serum independent from the test kit manufacturer.

Incidence of balanitis xerotica obliterans in boys younger than 10 years presenting with phimosis.

OBJECTIVE: Evaluation of the true incidence of balanitis xerotica obliterans (BXO) among boys younger than 10 years. METHODS: In a period of 13 months, 75 boys younger than 10 years were treated for phimosis. Suspicion of BXO was raised in phimosis grade 2 or 3 (classification by Kikiros). Patients were offered primarily either circumcision or conservative therapy and circumcision secondarily (if treatment failed in the conservative group). Each circumcision specimen was examined histopathologically. RESULTS: Circumcision was primarily performed in 29 and secondarily in 17 patients. The mean age was 3.7 years (range 1-10). BXO, chronic inflammation, and normal histological results were found in 8/26/12 (17.4/56.5/26.1%) cases, respectively. The mean follow-up was 8.1 months. No recurrences were reported. CONCLUSIONS: The incidence of BXO appears to be higher than previously reported. The clinical appearance in children may be confusing. The preoperative BXO suspicion did not correlate with the final histopathological results.

Alpha-1-Fetoprotein (AFP): international proficiency study with different test systems.

BACKGROUND: The present proficiency study aimed to elucidate the comparability and reliability of test systems for the determination of AFP concentrations. METHODS: 25 laboratories using 8 different commercial test systems used liquid BIOREF-AFP control serum in their routine internal quality control over a period of one year. For statistical analysis the results were collected centrally. RESULTS: The statistical analysis of the test results revealed considerable variation for the different laboratories. The deviations of the mean values of different laboratories from the overall mean value varied between 0.1 and 26.1%, and for most of the laboratories the deviation was round about 10%. The precision of measured values in the individual laboratories was in most cases acceptable: Nevertheless, the coefficients of variation of the individual laboratories ranged from 13 to 16.1%. CONCLUSIONS: In conclusion, this study indicates that AFP results vary between different laboratories albeit an international standard for AFP is available. Therefore, every laboratory should participate in external ring studies and should use a quality control serum independent of the test kit manufacturer for the internal quality control.

Association of insulin sensitivity to lipids across the lifespan in people with Type 1 diabetes.

AIMS: Insulin resistance and dyslipidaemia both increase cardiovascular risk in Type 1 diabetes. However, little data exist on the associations of insulin resistance to lipids in Type 1 diabetes. Our objective was to explore the associations between insulin resistance (assessed by glucose infusion rate) and lipids in people with Type 1 diabetes and determine whether adiposity and/or average glycaemia influence these associations. METHODS: Hyperinsulinaemic-euglycaemic clamp studies were performed in 60 subjects with Type 1 diabetes aged 12-19 years (age 15±2 years, 57% female, duration of diabetes 6.3±3.8 years, HbA(1c) 8.6±1.5%, IFCC=70 mmol/mol) and 40 subjects with Type 1 diabetes aged 27-61 years (age 45±9 years, 53% female, duration of diabetes 23±8 years, HbA(1c) 7.5±0.9%, IFCC=58 mmol/mol). Multiple linear regression models were fit to examine the association between glucose infusion rate and fasting lipid levels with adjustment for possible confounders. RESULTS: Lower glucose infusion rate was significantly associated with lower levels of HDL cholesterol in youths with Type 1 diabetes and with higher levels of triglycerides and higher triglyceride/HDL ratio in both youths and adults. The magnitude of the associations between glucose infusion rate and lipid levels translate into interquartile differences of 0.098 mmol/l for HDL cholesterol, 0.17 mmol/l for triglycerides and 1.06 for triglycerides/HDL in the adolescents and 0.20 mmol/l for triglycerides and 1.01 for triglycerides/HDL in the adults. The associations were attenuated and no longer statistically significant by adjustment for adiposity among adults, while adjustment for HbA(1c) had a small effect in youths and adults. CONCLUSIONS: Lower insulin sensitivity is associated with a more atherogenic lipid profile in both youths and adults with Type 1 diabetes.

Glycaemic variability is associated with coronary artery calcium in men with Type 1 diabetes: the Coronary Artery Calcification in Type 1 Diabetes study.

AIMS: We investigated coronary artery calcium in association with glucose levels and variability measured using continuous glucose monitoring in adults with Type 1 diabetes in the Coronary Artery Calcification in Type 1 Diabetes study. METHODS: Coronary artery calcium was measured by electron beam tomography. The presence of any coronary artery calcium was analysed with respect to glucose levels [mean(T) (mean glucose), % of values < 3.9 mmol/l, > 10 mmol/l and either < 3.9 or > 10 mmol/l] and glycaemic variability [sd(T) (sd of all glucose values); sd(dm) (sd of the daily mean glucose levels) and sd(hh:mm) (glucose sd for a specified time of day, over all days)] using 3-5 days of continuous glucose monitoring from 75 subjects (45 women, 30 men), age 42 ± 9 years (mean ± sd) and diabetes duration of 29 ± 8 years using logistic regression. RESULTS: We observed significant associations between coronary artery calcium and mean(T) (OR = 4.4, 95% CI 1.1-18.6), % of values > 10 mmol/l (OR = 5.5, 95% CI 1.3-22.6), % of measures < 3.9 or > 10 mmol/l (OR = 5.7, 95% CI 1.3-24.9), sd(T) (OR = 4.7, 95% CI 1.1-19.7), sd(dm) (OR = 6.0, 95% CI 1.2-30.4) and sd(hh:mm) (OR = 4.0, 95% CI 1.1-15.4), among men, but none of these variables were associated with the presence of coronary artery calcium in women. CONCLUSIONS: We report the novel finding that subclinical atherosclerosis is associated with glucose levels and variability in men with Type 1 diabetes. The relationship of coronary artery calcium and glucose variability in Type 1 diabetes, and potential gender differences in this association, deserve further study.

Precision and long-term stability of different estradiol immunoassays assessed in a multi-center quality control study.

BACKGROUND: Because of the vast range of physiological relevant estradiol concentrations the requirements to be met by an estradiol assay are high. In the present study the performance of various commercially available estradiol assays was evaluated with regard to imprecision and long-term stability. METHODS: Precision and long-term stability of 7 commercially available estradiol immunoassays were assessed in a multi-centre quality control study based on the repeated measurement of liquid BIOREF estradiol control sera by 18 laboratories during a 14-month study period. RESULTS: The mean estradiol concentrations determined in 594 runs performed for each control level were 71 pg/ml, 349 pg/ml and 676 pg/ml. A high variation was found for the method specific mean values calculated from all results measured with the same method, which ranged between 32 - 90 pg/ml, 187 - 392 pg/ml and 373 - 790 pg/ml, resulting in a similar high inter-laboratory variation with coefficients of variation (CVs) of 25.0%, 16.7% and 17.5%. In contrast, the intra-laboratory variation of estradiol values as well as the variation of values measured with the same method were found to be considerably lower with coefficients of variation < 10% for most laboratories and methods; only the low control level was measured with CV values > 10% by the majority of laboratories and methods. For none of the laboratories a tendency was observed in the results from beginning to end of the 14 month study period indicating a high uniformity in assay production and a good long-term stability of the control material used. CONCLUSIONS: The present data demonstrate that also with the currently available estradiol immunoassays the comparability of results measured with different methods is limited. With most assays very low estradiol concentrations, as observed in postmenopausal women, can be determined only with a precision which is not adequate for clinical assessment.

Cyclin D1 as a proliferative marker regulating retinoblastoma phosphorylation in mouse lung epithelial cells.

Elevations in cyclin D1 content increase the phosphorylation status of retinoblastoma (Rb) protein to encourage cell cycle transit. We sought to determine if cyclin D1 content could be used as an index of cell proliferation in mouse lung epithelia following growth manipulations in vitro and in vivo. Rb protein concentration was high in 82-132 and LM2, two fast-growing neoplastic mouse lung epithelial cell lines. The hyperphosphorylated form of Rb predominated in these two cell lines, while Rb in slower-growing cell lines was predominantly hypophosphorylated. Consistent with this, more cyclin D1 protein was expressed in the fast-growing cell lines than in slower-growing cells. We therefore tested whether cyclin D1 content varied with growth status. The amount of cyclin D1 decreased upon serum removal coincident with growth inhibition and then increased upon serum re-addition which stimulated resumption of proliferation. This correlation between cyclin D1 content and growth status also occurred in vivo. Cyclin D1 content increased when lungs underwent compensatory hyperplasia following damage caused by butylated hydroxytoluene administration to mice and in lung tumor extracts as compared with extracts prepared from uninvolved tissue or control lungs. We conclude that elevated cyclin D1 levels account, at least in part, for the hyperphosphorylation of Rb in neoplastic lung cells, and are associated with enhanced lung growth in vitro and in vivo.

Oligomers of the Cdc7/Dbf4 protein kinase exist in the yeast cell.

Cdc7/Dbf4 protein kinase is required for the initiation of DNA replication in Saccharomyces cerevisiae. Cdc7/Dbf4 protein kinase is not a cyclin-dependent kinase (CDK), but is regulated in a similar fashion in that the Cdc7 kinase subunit is inactive in the absence of the regulatory subunit Dbf4. In contrast to what is known about CDKs, Cdc7/Dbf4 protein kinase is shown to be an oligomer in the cell in this report. Genetic data that support this claim include interallelic complementation between several cdc7ts alleles and the cdc7T281A allele and also the results of experiments using the two-hybrid system with Cdc7 in both DNA-binding and transactivation domain plasmids. A molecular interaction between two different Cdc7 molecules was shown by using a HA-tagged Cdc7 protein that differs in size from the wild-type Cdc7 protein: an anti-HA antibody immunoprecipitates both proteins in approximately equal stoichiometry. Analysis of the native molecular weight of Cdc7/Dbf4 protein kinase is consistent with oligomerization of the Cdc7 protein in that complexes of about 180 and 300 kDa were found. Oligomers of Cdc7 protein may exist for the purpose of allosteric regulation or to allow phosphorylation of multiple substrate protein molecules.

Biphasic regulation of breast cancer cell growth by progesterone: role of the cyclin-dependent kinase inhibitors, p21 and p27(Kip1).

Depending on the tissue, progesterone is classified as a proliferative or a differentiative hormone. To explain this paradox, and to simplify analysis of its effects, we used a breast cancer cell line (T47D-YB) that constitutively expresses the B isoform of progesterone receptors. These cells are resistant to the proliferative effects of epidermal growth factor (EGF). Progesterone treatment accelerates T47D-YB cells through the first mitotic cell cycle, but arrests them in late G1 of the second cycle. This arrest is accompanied by decreased levels of cyclins D1, D3, and E, disappearance of cyclins A and B, and sequential induction of the cyclin-dependent kinase (cdk) inhibitors p21 and p27(Kip1). The retinoblastoma protein is hypophosphorylated and extensively down-regulated. The activity of the cell cycle-dependent protein kinase, cdk2, is regulated biphasically by progesterone: it increases initially, then decreases. This is consistent with the biphasic proliferative increase followed by arrest produced by one pulse of progesterone. A second treatment with progesterone cannot restart proliferation despite adequate levels of transcriptionally competent PR. Instead, a second progesterone dose delays the fall of p21 and enhances the rise of p27(Kip1), thereby intensifying the progesterone resistance in an autoinhibitory loop. However, during the progesterone-induced arrest, the cell cycling machinery is poised to restart. The first dose of progesterone increases the levels of EGF receptors and transiently sensitizes the cells to the proliferative effects of EGF. We conclude that progesterone is neither inherently proliferative nor antiproliferative, but that it is capable of stimulating or inhibiting cell growth depending on whether treatment is transient or continuous. We also suggest that the G1 arrest after progesterone treatment is accompanied by cellular changes that permit other, possibly tissue-specific, factors to influence the final proliferative or differentiative state.

Cell cycle control and cancer: lessons from lung cancer.

Recent developments in the study of the cell cycle have shed much light on the origins of human cancer. We summarize these developments with an emphasis on the molecular characterization and the functional role of the cyclin-dependent kinase family of protein kinases (CDK) and their associated regulatory subunits. The Rb tumor suppressor in the progression from the G1 to S phase of the cell cycle and in tumor development is used as a paradigm for illustrating the importance of understanding the molecular regulatory events in the etiology of cancer. Recent developments with cyclin-dependent kinase inhibitors, most notably, p16 (CDKN2), indicate that these molecules represent new tumor suppressors in both skin and lung cancers. Insights from these cell cycle studies can provide avenues for the diagnosis, prognosis, and potential gene and chemotherapies for many cancers, including non-small cell lung cancer.

Cyclin D1 overexpression vs. retinoblastoma inactivation: implications for growth control evasion in non-small cell and small cell lung cancer.

The cyclin-dependent kinases and their associated regulatory cyclins control cell cycle progression and cell growth. Antibodies against these proteins were used to determine their levels in several lung tumor-derived cell lines and a "normal" immortalized bronchoepithelial cell line in order to investigate their potential roles in the etiology of lung cancer. All the cell lines expressed roughly equal levels of cdk-1; cdk-2; PSTAIRE-sequence containing kinases; proliferating cell nuclear antigen; and cyclins A, B1, and E. Cyclin D1, however, was present at 4- to 100-fold higher levels in 11 of 12 non-small cell lung cancer cell lines than in the bronchoepithelial line and all but one of the small cell lung cancer lines. Furthermore, immunoblots of the retinoblastoma gene product, pRB, revealed a perfect correlation between pRB levels and tumor type with normal levels of phosphorylation-competent pRB in all of the non-small cell lung cancer lines and undetectable levels of pRB in all of the small cell lung cancer lines. These data suggest the possibility that small cell and non-small cell lung cancer may evade normal growth controls by different mechanisms: loss of the proliferation inhibitor pRB in small cell lung cancer and overexpression of the growth promoting cyclin D1 in non-small cell lung cancer.

Functional behaviour of mononuclear blood cells from patients with hypercholesterolemia.

Mononuclear cells were prepared from venous blood obtained from 20 patients with a newly diagnosed hypercholesterolemia and without clinical signs of vascular disease, and from 19 age and sex matched controls. Adhesiveness to plastic surface, phagocytic activity measured as ingestion of zymosan particles, and spontaneous motility of mononuclear cells from patients were significantly higher by 57%, 19% and 50%, respectively, when compared to controls. In controls chemotaxis induced by the chemotactic peptide FMLP was slightly higher than spontaneous motility measured in absence of FMLP, whereas in patients FMLP significantly inhibited cell motility by about 47%. With the exception of FMLP-induced chemotaxis the results indicate that mononuclear cells are hyperreactive in hypercholesterolemia.

Early C. elegans embryos are transcriptionally active.

We have developed a nucleotide incorporation assay for run-on transcription in C. elegans embryonic extracts as an approach to characterizing early transcription. The incorporation is primarily polymerase II-catalyzed RNA synthesis, producing transcripts of the expected size range for mRNAs. Incorporation is insensitive to inhibitors of reinitiation, indicating that the activity represents primarily elongation of nascent chains initiated prior to extract preparation. The transcripts produced appear to be unprocessed pre-mRNAs. Hybridization of labeled transcripts from extracts of staged embryos to a set of cloned genes suggests that the specificity of the in vitro reaction accurately reflects developmentally regulated in vivo transcription. Comparative analyses of transcription in extracts from various stages indicate that pregastrulation embryos are active transcriptionally and that the level of transcription per nucleus is approximately constant throughout embryogenesis. Furthermore, most embryonically expressed genes are already being transcribed in pregastrulation embryos. We also demonstrate that the labeled embryonic run-on transcripts can be used as probes to screen for sequences transcribed preferentially in pregastrulation embryos. There appears to be only a small set of such sequences, which could represent a previously unsuspected class of embryonically transcribed genes important for early embryogenesis.

Inhibition of human lecithin: cholesterol acyltransferase activity by catecholamines in vitro.

The effects of L-adrenaline and L-noradrenaline on human lecithin: cholesterol acyltransferase (LCAT) activity were investigated in vitro. Both catecholamines are shown to be inhibitors of this enzyme. Despite inter-individual variations in the dose-response relationships calculated for both hormones, significant effects can be expected in the upper physiological range of concentration. Since diminished LCAT activity is known to be followed by a low level of HDL cholesterol and an increased concentration of triglycerides, it is supposed that catecholamine mediated inhibition of LCAT activity may contribute to the development of stress mediated fluctuations in plasma lipoprotein concentrations.

[Triglyceride determination with the Sumal system in routine operations]. / Triglyceridbestimmung mit dem Sumal-System im Routinebetrieb.

A micromethod for determination of serum triglyceride concentrations using the Sumal-system and the sampler Sumal PVS 100 will be described. The results show that the qualitative, technical and economic parameters of the method (coefficient of variation 5%, 500 specimens per day and examiner, cost of reagents 0.50 M per test) correspond to the requirements of standard techniques and methods used in prevention trials. The method is suitable for use in routine clinical laboratory.

[Lipoprotein metabolism and beta receptor blockers]. / Lipoproteinstoffwechsel und beta-Rezeptorenblocker.

Including own results a survey is given of the side effects of beta-receptor blockers on the plasma lipoprotein metabolism. The formation of a from the coronary-preventive point of view unfavourable lipoprotein risk profile under influence of individual beta-receptor blockers, among others propranolol, seems to be connected with an inhibition of a key enzyme in the lipoprotein metabolism, the lecithin-cholesterol-acyl transferase. Talinolol does not show these side effects. It is recommended to control the triglyceride level and the HDL cholesterol before the induction and after the beginning of a therapy with beta-receptor blockers and to use talinolol instead of propranolol in pre-existing dyslipoproteinaemia or in unfavourable changes during the treatment.

Structure, assembly, and secretion of octameric invertase.

Yeast invertase forms a homo-octamer of core glycosylated subunits during assembly in the lumen of the endoplasmic reticulum. This form has been purified from mutant cells (sec18) in which transport of secreted proteins from the endoplasmic reticulum is blocked. No heterologous protein subunits are found in the purified material. Analysis of invertase derived from wild type cells or from mutant cells blocked at subsequent stages in secretion demonstrates that invertase remains a homo-octamer throughout the pathway even though the extent of subunit glycosylation increases. Purified octameric invertase is dissociated into dimer units that reassociate in the presence of polyethylene glycol. Negatively stained preparations show the dissociated enzyme as individual spheres, whereas octameric invertase appears as four associated spheres. Assembly of the octamer in vitro and in vivo is facilitated by the presence of N-linked carbohydrate. Selective release of dimeric glycosylated invertase from intact yeast cells suggests that oligomerization helps retain the enzyme in the periplasmic space.