Gel chromatographic characterization of immunoreactive adrenocorticotropin in patients with ACTH hypersecretion

We investigated the molecular size of circulating immunoreactive ACTH by gel chromatography in patients with ACTH hypersecretion due to various disorders of the hypothalamic-pituitary-adrenal axis. 4 patients with Addison's disease, 2 with Nelson's syndrome, 4 with Cushing's disease, 6 with the ectopic ACTH syndrome (2 bronchial carcinoma, 1 medullary carcinoma, 1 metastatic islett cell carcinoma, 1 benign bronchial carcinoid and 1 patient with occult ectopic Cushing's syndrome) and 1 patient with hypersecretion of ACTH from a clinically nonfunctioning pituitary adenoma were studied. Analysis of the molecular size of immunoreactive ACTH was performed by gel chromatography on a Sephadex G-75 column (superfine, 100×1.5 cm) equilibrated with 1% formic acid. 2 ml fractions were collected and evaporated to dryness. The ACTH content of the recovered samples was determined by RIA. In Addison's disease, Nelson's syndrome and Cushing's disease the plasma showed a single peak of ACTH immunoreactivity at the expected position of 1–39 ACTH. In the ectopic ACTH syndrome the plasma of 4 patients revealed at chromatography at least one other peak eluting between the void volume and 1–39 ACTH suggestive of a high molecular weight form of ACTH whereas plasma of 2 patients showed only a single ACTH peak at the position of labeled 1–39 ACTH. The patient with a clinically non-functioning pituitary adenoma revealed a gel filtration pattern similar to the patients with ectopic ACTH syndrom and secretion of high molecular weight ACTH. We conclude that secretion of high molecular weight forms of ACTH is not a unique feature of the ectopic ACTH syndrome. It may therefore not serve as a marker of the ectopic Cushing's syndrome in the differential diagnosis of the ACTH dependent Cushing's syndrome. Vice versa, lack of high molecular weight ACTH does not exclude an ectopic source of ACTH secretion as cause of Cushing's syndrome

Abnormal function of the vasopressin-cyclic-AMP-aquaporin2 axis during urine concentrating and diluting in patients with reduced renal function. A case control study

<p>Abstract</p> <p>Background</p> <p>The kidneys ability to concentrate and dilute urine is deteriorated during progressive renal insufficiency. We wanted to test the hypothesis that these phenomena could be attributed to an abnormal function of the principal cells in the distal part of the nephron.</p> <p>Methods</p> <p>Healthy control subjects and patients with chronic kidney diseases were studied. Group 1 comprised healthy subjects, n = 10. Groups 2-4 comprised patients with chronic kidney disease (Group 2, n = 14, e-GFR ? 90 m1/min; Group 3, n = 11, 60 m1/min ? e-GFR < 90 ml/min; and Group 4, n = 16, 15 ml/min ? e-GFR < 60 ml/min). The subjects collected urine during 24 hours. A urine concentrating test was done by thirsting during the following 12 hours. Thereafter, a urine diluting test was performed with a water load of 20 ml/kg body weight. The effect variables were urinary excretions of aquaporin2 (u-AQP2), cyclic-AMP (u-c-AMP), urine volume (UV), free water clearance (C_H2O), urine osmolarity (u-Osm), and plasma arginine vasopressin (p-AVP).</p> <p>Results</p> <p>After fluid deprivation, u-Osm increased. In all groups, UV and C_H2Odecreased and u-AQP2 and u-c-AMP increased in Groups 1 and 2, but were unchanged in Group 3 and 4. P-AVP was significantly higher in Group 4 than in the other groups. During urine diluting, UV and C_H2Oreached significantly higher levels in Groups 1-3 than Group 4. Both before and after water loading, u-AQP2 and p-AVP were significantly higher and u-c-AMP was significantly lower in Group 4 than the other groups. Estimated-GFR was correlated negatively to p-AVP and positively to u-c-AMP.</p> <p>Conclusions</p> <p>Patients with moderately severe chronic kidney disease have a reduced renal concentrating and diluting capacity compared to both patients with milder chronic kidney disease and healthy control subjects. These phenomena can be attributed, at least partly, to an abnormally decreased response in the AVP-c-AMP-AQP2 axis.</p> <p>ClinicalTrials.Gov Identifier: NCT00313430</p

Abnormal increase in urinary aquaporin-2 excretion in response to hypertonic saline in essential hypertension

<p>Abstract</p> <p>Background</p> <p>Dysregulation of the expression/shuttling of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in renal collecting duct principal cells has been found in animal models of hypertension. We tested whether a similar dysregulation exists in essential hypertension.</p> <p>Methods</p> <p>We measured urinary excretion of AQP2 and ENaC β-subunit corrected for creatinine (u-AQP2_CR, u-ENaC_β-CR), prostaglandin E2 (u-PGE₂) and cyclic AMP (u-cAMP), fractional sodium excretion (FE_Na), free water clearance (C_H2O), as well as plasma concentrations of vasopressin (AVP), renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), and atrial and brain natriuretic peptide (ANP, BNP) in 21 patients with essential hypertension and 20 normotensive controls during 24-h urine collection (baseline), and after hypertonic saline infusion on a 4-day high sodium (HS) diet (300 mmol sodium/day) and a 4-day low sodium (LS) diet (30 mmol sodium/day).</p> <p>Results</p> <p>At baseline, no differences in u-AQP2_CRor u-ENaC_β-CRwere measured between patients and controls. U-AQP2_CRincreased significantly more after saline in patients than controls, whereas u-ENaC_β-CRincreased similarly. The saline caused exaggerated natriuretic increases in patients during HS intake. Neither baseline levels of u-PGE₂, u-cAMP, AVP, PRC, Ang II, Aldo, ANP, and BNP nor changes after saline could explain the abnormal u-AQP2_CRresponse.</p> <p>Conclusions</p> <p>No differences were found in u-AQP2_CRand u-ENaC_β-CRbetween patients and controls at baseline. However, in response to saline, u-AQP2_CRwas abnormally increased in patients, whereas the u-ENaC_β-CRresponse was normal. The mechanism behind the abnormal AQP2 regulation is not clarified, but it does not seem to be AVP-dependent.</p> <p>Clinicaltrial.gov identifier</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=00345124">NCT00345124</a>.</p

Use of photosensitising diuretics and risk of skin cancer: a population-based case–control study

Diuretics have photosensitising properties. However, little is known about how these diuretics affect the risk of skin cancers. In North Jutland County, Denmark, we investigated whether the use of photosensitising diuretics was associated with an increased risk for developing basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). From the cancer registry, we identified primary cases of BCC, SCC and MM during the period of 1989–2003. We selected four population controls for each case from the Danish Civil Registration System, matched on age and gender. Prescriptions for photosensitising diuretics before cancer diagnosis were ascertained in the county's Prescription Database. We used conditional logistic regression to compute incidence rate ratio (IRR), controlling for the chronic medical conditions and for the previous use of oral glucocorticoids. We found an increased risk of SCC (IRR of 1.79 (95% confidence interval (CI): 1.45–2.21)) and MM (IRR of 1.43 (95% CI: 1.09–1.88)) among users of combined amiloride and hydrochlorothiazide therapy. An increased risk of MM (IRR of 3.30 (95% CI: 1.34–8.10)) was found among users of indapamide. We found little associations with risk of BCC. Our findings provide evidence that the use of some photosensitising diuretics is associated with an increased risk for SCC and MM

Phase transitions in biological membranes

Native membranes of biological cells display melting transitions of their lipids at a temperature of 10-20 degrees below body temperature. Such transitions can be observed in various bacterial cells, in nerves, in cancer cells, but also in lung surfactant. It seems as if the presence of transitions slightly below physiological temperature is a generic property of most cells. They are important because they influence many physical properties of the membranes. At the transition temperature, membranes display a larger permeability that is accompanied by ion-channel-like phenomena even in the complete absence of proteins. Membranes are softer, which implies that phenomena such as endocytosis and exocytosis are facilitated. Mechanical signal propagation phenomena related to nerve pulses are strongly enhanced. The position of transitions can be affected by changes in temperature, pressure, pH and salt concentration or by the presence of anesthetics. Thus, even at physiological temperature, these transitions are of relevance. There position and thereby the physical properties of the membrane can be controlled by changes in the intensive thermodynamic variables. Here, we review some of the experimental findings and the thermodynamics that describes the control of the membrane function.Comment: 23 pages, 15 figure

The small GTPase Rab29 is a common regulator of immune synapse assembly and ciliogenesis

Acknowledgements We wish to thank Jorge Galán, Gregory Pazour, Derek Toomre, Giuliano Callaini, Joel Rosenbaum, Alessandra Boletta and Francesco Blasi for generously providing reagents and for productive discussions, and Sonia Grassini for technical assistance. The work was carried out with the financial support of Telethon (GGP11021) and AIRC.Peer reviewedPostprin

Generation of fusion protein EGFRvIII-HBcAg and its anti-tumor effect in vivo

The epidermal growth factor receptor variant III (EGFRvIII) is the most common variation of EGFR. Because it shows a high frequency in several different types of tumor and has not been detected in normal tissues, it is an ideal target for tumor specific therapy. In this study, we prepared EGFRvIII-HBcAg fusion protein. After immunization with fusion protein, HBcAg or PBS, the titers of antibody in BALB/c mice immunized with fusion protein reached 2.75 × 105. Western blot analysis demonstrated that the fusion protein had specific antigenicity against anti-EGFRvIII antibody. Further observation showed fusion protein induced a high frequency of IFN-γ-secreting lymphocytes. CD4+T cells rather than CD8+T cells were associated with the production of IFN-γ. Using Renca-vIII(+) cell as specific stimulator, we observed remarkable cytotoxic activity in splenocytes from mice immunized with fusion protein. Mice were challenged with Renca-vIII(+) cells after five times immunization. In fusion protein group, three of ten mice failed to develop tumor and all survived at the end of the research. The weight of tumors in fusion protein were obviously lighter than that in other two groups (t = 4.73, P = 0.044;t = 6.89, P = 0.040). These findings demonstrated that EGFRvIII-HBcAg fusion protein triggered protective responses against tumor expressing EGFRvIII

Temporal changes in frequency of severe hypoglycemia treated by emergency medical services in types 1 and 2 diabetes:a population-based data-linkage cohort study

Background&nbsp; Almost 20 years ago, the frequencies of severe hypoglycemia requiring emergency medical treatment were reported in people with types 1 and 2 diabetes in the Tayside region of Scotland. With subsequent improvements in the treatment of diabetes, concurrent with changes in the provision of emergency medical care, a decline in the frequency of severe hypoglycemia could be anticipated. The present population-based data-linkage cohort study aimed to ascertain whether a temporal change has occurred in the incidence rates of hypoglycemia requiring emergency medical services in people with types 1 and 2 diabetes.&nbsp; Methods&nbsp; The study population comprised all people with diabetes in Tayside, Scotland over the period 1 January 2011 to 31 December 2012. Patients&rsquo; data from different healthcare sources were linked anonymously to measure the incidence rates of hypoglycemia requiring emergency medical services that include treatment by ambulance staff and in hospital emergency departments, and necessitated hospital admission. These were compared with data recorded in 1997&ndash;1998 in the same region.&nbsp; Results&nbsp; In January 2011 to December 2012, 2029 people in Tayside had type 1 diabetes and 21,734 had type 2 diabetes, compared to 977 and 7678, respectively, in June 1997 to May 1998. In people with type 2 diabetes, the proportion treated with sulfonylureas had declined from 36.8 to 22.4% (p&lt;0.001), while insulin-treatment had increased from 11.7 to 18.7% (p&lt;0.001). The incidence rate of hypoglycemia requiring emergency medical treatment had significantly fallen from 0.115 (95% CI: 0.094&ndash;0.136) to 0.082 (0.073&ndash;0.092) events per person per year in type 1 diabetes (p&lt;0.001), and from 0.118 (0.095&ndash;0.141) to 0.037 (0.003&ndash;0.041) in insulin-treated type 2 diabetes (p=0.008). However, the absolute annual number of hypoglycemia events requiring emergency treatment was 1.4-fold higher.&nbsp; Conclusions&nbsp; Although from 1998 to 2012 the incidences of hypoglycemia requiring emergency medical services appeared to have declined by a third in type 1 diabetes and by two thirds in insulin-treated type 2 diabetes, because the prevalence of diabetes was higher (2.7 fold), the number of severe hypoglycemia events requiring emergency medical treatment was greater

Apathy, but Not Depression, Reflects Inefficient Cognitive Strategies in Parkinson's Disease

The relationship between apathy, depression and cognitive impairment in Parkinson's disease (PD) is still controversial. The objective of this study is to investigate whether apathy and depression are associated with inefficient cognitive strategies in PD.In this prospective clinical cohort study conducted in a university-based clinical and research movement disorders center we studied 48 PD patients. Based on clinical evaluation, they were classified in two groups: PD with apathy (PD-A group, n = 23) and PD without apathy (PD-NA group, n = 25). Patients received clinical and neuropsychological evaluations. The clinical evaluation included: Apathy Evaluation Scale-patient version, Hamilton Depression Rating Scale-17 items, the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr staging system; the neuropsychological evaluation explored speed information processing, attention, working memory, executive function, learning abilities and memory, which included several measures of recall (immediate free, short delay free, long delay free and cued, and total recall).PD-A and PD-NA groups did not differ in age, disease duration, treatment, and motor condition, but differed in recall (p<0.001) and executive tasks (p<0.001). Immediate free recall had the highest predictive value for apathy (F = 10.94; p = 0.002). Depression and apathy had a weak correlation (Pearson index= 0.3; p<0.07), with three items of the depression scale correlating with apathy (Pearson index between .3 and.4; p<0.04). The depressed and non-depressed PD patients within the non-apathetic group did not differ.Apathy, but not depression, is associated with deficit in implementing efficient cognitive strategies. As the implementation of efficient strategies relies on the fronto-striatal circuit, we conclude that apathy, unlike depression, is an early expression of executive impairment in PD

Type D patients report poorer health status prior to and after cardiac rehabilitation compared to non-type D patients

Background: Type D personality is an emerging risk factor in coronary artery disease (CAD). Cardiac rehabilitation (CR) improves outcomes, but little is known about the effects of CR on Type D patients. Purpose: We examined (1) variability in Type D caseness following CR, (2) Type D as a determinant of health status, and (3) the clinical relevance of Type D as a determinant of health status compared to cardiac history. Methods: CAD patients (n = 368) participating in CR completed the Type D Scale, the Short-Form Health Survey 36 pre- and post-CR, and the Hospital Anxiety and Depression Scale pre-CR, to assess health status and depressive and anxious symptomatology, respectively. Results: The prevalence of Type D decreased from 26.6% to 20.7% (p = 0.012) following CR, but Type D caseness remained stable in 81% of patients. Health status significantly improved following CR [F(1,359) = 17.48, p < 0.001], adjusting for demographic and clinical factors and anxious and depressive symptoms. Type D patients reported poorer health status [F(1,359) = 10.40, p = 0.001], with the effect of Type D being stable over time [F(1,359) = 0.49, p = 0.48]. Patients with a cardiac history benefited less from CR [F(1,359) = 5.76, p = 0.02]. The influence of Type D on health status was larger compared to that for cardiac history, as indicated by Cohen's effect size index. Conclusions: Type D patients reported poorer health status compared to non-Type D patients pre- and post-CR. In the majority of patients, CR did not change Type D caseness, with Type D being associated with a stable and clinically relevant effect on outcome. These high-risk patients should