T1-Enhanced MRI-visible nanoclusters for imaging-guided drug delivery.

Iron oxide nanoparticles with extremely low dimensions have recently been explored as positive (T1) contrast agent for magnetic resonance imaging (MRI). However, their small sizes lead to fast renal clearance and limit their use in elongated in vivo tracking or therapy monitoring. In this paper, we present a state of art approach to forming nanoclusters by crosslinking ultrasmall iron oxide nanoparticles with bovine serum albumin. This novel design not only maintains the T1 performance of the ultrasmall nanoparticles, but also significantly increases their blood circulation times from 15 minutes to over two hours. Our breast tumor model study also exhibited enhanced contrast at tumor sites for more than 24 hours. The ability of maintaining the T1 performance of the ultrasmall nanoparticles is significant, because previous studies have shown complete T1 loss or signal decrease upon polymer encapsulation. This design also shows great potential in encapsulating model drug molecules, which will greatly benefit the field of imaging-guided drug delivery.

Shape-dependent cellular behaviors and relaxivity of iron oxide-based T1 MRI contrast agents.

Recent research efforts about iron oxide nanoparticles has focused on the development of iron oxide-based T1 contrast agents for magnetic resonance imaging (MRI), such as ultrasmall iron oxide nanospheres (USNPs <4 nm) and ultrathin nanowires (NW, diameter <4 nm). In this paper, we report the cellular uptake behaviors of these two types of ultrasmall scale nanostructures on HepG2 cells. Both these two nanostructures were functionalized with tannic acid and their physical and chemical properties were carefully analyzed before cellular tests. Both USNPs and NWs exhibited strong paramagnetic signals, a property suitable for T1 MRI contrast agents. The distinct shapes also caused much difference in their cellular uptake behaviors. Specifically, the uptake of USNPs was five times higher than that of NWs after 72 hours incubation. The shape-dependent cellular uptake can potentially lead to different blood circulation times, and subsequently different applications of these two types of ultrasmall nanostructures.

Consensus statement on the diagnosis, treatment and follow-up of patients with primary adrenal insufficiency.

Primary adrenal insufficiency (PAI), or Addison's disease, is a rare, potentially deadly, but treatable disease. Most cases of PAI are caused by autoimmune destruction of the adrenal cortex. Consequently, patients with PAI are at higher risk of developing other autoimmune diseases. The diagnosis of PAI is often delayed by many months, and most patients present with symptoms of acute adrenal insufficiency. Because PAI is rare, even medical specialists in this therapeutic area rarely manage more than a few patients. Currently, the procedures for diagnosis, treatment and follow-up of this rare disease vary greatly within Europe. The common autoimmune form of PAI is characterized by the presence of 21-hydroxylase autoantibodies; other causes should be sought if no autoantibodies are detected. Acute adrenal crisis is a life-threatening condition that requires immediate treatment. Standard replacement therapy consists of multiple daily doses of hydrocortisone or cortisone acetate combined with fludrocortisone. Annual follow-up by an endocrinologist is recommended with the focus on optimization of replacement therapy and detection of new autoimmune diseases. Patient education to enable self-adjustment of dosages of replacement therapy and crisis prevention is particularly important in this disease. The authors of this document have collaborated within an EU project (Euadrenal) to study the pathogenesis, describe the natural course and improve the treatment for Addison's disease. Based on a synthesis of this research, the available literature, and the views and experiences of the consortium's investigators and key experts, we now attempt to provide a European Expert Consensus Statement for diagnosis, treatment and follow-up.

Phenotypic variation in a large family with autosomal dominant hypocalcaemia.

BACKGROUND/AIMS: Autosomal dominant hypocalcaemia (ADH) is caused by activating mutations in the calcium- sensing receptor (CASR). We aimed to describe the phenotypic variation within a large family with ADH, especially kidney and cerebral basal ganglia calcifications. METHODS: Fifteen related subjects carrying the CASR mutation T151M participated in a cross-sectional study of calcium homeostasis, renal ultrasonography, cerebral CT, bone mineral density, and health-related quality of life (HRQoL). RESULTS: Eight subjects had received vitamin D treatment (mean duration 15.3 years; range 11-20 years). Urinary calcium excretion was elevated in 5/8 vitamin-D-treated and in 3/7 untreated subjects. Serum magnesium, calcium and parathyroid hormone remained at the lower reference limit or below. Renal calcifications were found in 12 of 14 (86%) and basal ganglia calcifications in 5 of 11 (46%) subjects, independently of vitamin D therapy. The glomerular filtration rate was moderately reduced in 3 subjects. Mean bone mineral density and bone markers were normal. HRQoL was impaired in the vitamin-D-treated group despite correction of the hypocalcaemia. CONCLUSIONS: The impact of the CASR mutation on calcium homeostasis varied greatly. Kidney and basal ganglia calcifications are common in ADH independently of vitamin D treatment, which, however, increases urinary calcium excretion and may promote urolithiasis.

Tetradecylthioacetic acid attenuates dyslipidaemia in male patients with type 2 diabetes mellitus, possibly by dual PPAR-alpha/delta activation and increased mitochondrial fatty acid oxidation.

AIM: We previously demonstrated that a modified fatty acid, tetradecylthioacetic acid (TTA), improves transport and utilization of lipids and increases mitochondrial fatty acid oxidation in animal and cell studies. We conducted an exploratory study of safety and effects of this novel drug in patients with type 2 diabetes mellitus and investigated the mechanism of action in human cell lines. METHODS: Sixteen male patients with type 2 diabetes mellitus received 1 g TTA daily for 28 days in an open-labelled study, with measurement of parameters of lipid metabolism, glucose metabolism and safety (ClinicalTrials.gov NCT00605787). The mechanism of action was further investigated in a human liver cell line (HepG2) and in cultured human skeletal muscle cells (myotubes). RESULTS: Mean LDL cholesterol level declined from 4.2 to 3.7 mmol/l (p < 0.001), accompanied by increased levels of the HDL apolipoproteins A1 and A2, and a decline in LDL/HDL ratio from 4.00 to 3.66 (p = 0.008). Total fatty acid levels declined, especially the fraction of the polyunsaturated n-3 fatty acids docosahexaenoic acid (-13%, p = 0.002) and eicosapentaenoic acid (-10%, p = 0.07). Glucose metabolism was not altered and the drug was well tolerated. In cultured liver cells, TTA acted as a pan-PPAR agonist with predominant PPAR-alpha and PPAR-delta activation at low TTA concentrations. In myotubes, TTA and a PPAR-delta agonist, but not the PPAR-alpha or PPAR-gamma agonists, increased the fatty acid oxidation. CONCLUSIONS: We demonstrate for the first time that TTA attenuates dyslipidaemia in patients with type 2 diabetes mellitus. These effects may occur through mechanisms involving PPAR-alpha and PPAR-delta activation, resulting in increased mitochondrial fatty acid oxidation.

AIRE variations in Addison's disease and autoimmune polyendocrine syndromes (APS): partial gene deletions contribute to APS I.

Autoimmune Addison's disease (AAD) is often associated with other components in autoimmune polyendocrine syndromes (APS). Whereas APS I is caused by mutations in the AIRE gene, the susceptibility genes for AAD and APS II are unclear. In the present study, we investigated whether polymorphisms or copy number variations in the AIRE gene were associated with AAD and APS II. First, nine SNPs in the AIRE gene were analyzed in 311 patients with AAD and APS II and 521 healthy controls, identifying no associated risk. Second, in a subgroup of 25 of these patients, AIRE sequencing revealed three novel polymorphisms. Finally, the AIRE copy number was determined by duplex quantitative PCR in 14 patients with APS I, 161 patients with AAD and APS II and in 39 healthy subjects. In two Scandinavian APS I patients previously reported to be homozygous for common AIRE mutations, we identified large deletions of the AIRE gene covering at least exon 2 to exon 8. We conclude that polymorphisms in the AIRE gene are not associated with AAD and APS II. We further suggest that DNA analysis of the parents of patients found to be homozygous for mutations in AIRE, always should be performed.

Saliva cortisol measurement: simple and reliable assessment of the glucocorticoid replacement therapy in Addison's disease.

No ideal parameter is available for assessment of the glucocorticoid replacement therapy in Addison's disease. Serum cortisol day-curves can be used to monitor the therapy, but this technique is cumbersome and expensive. We evaluated the potential for saliva cortisol measurement in this setting. We found excellent correlation between serum and saliva cortisol after oral intake of cortisone acetate (no. 7) or iv administration of hydrocortisone (no. 4) (Pearson's R=0.83-0.98, p<0.002). A morning dose of 12.5 mg cortisone acetate yielded wide interindividual variations in cortisol levels in saliva. Saliva cortisol measurements were successfully adopted to evaluate and adjust doses in outpatients. We conclude that cortisol measurement in saliva is practical and reliable, and is preferable to serum cortisol measurement in the assessment of the glucocorticoid replacement therapy. Our results confirm that only a minority of patients require more than 12.5 mg of cortisone acetate (equivalent to 10 mg hydrocortisone) in the morning to have sufficient cortisol levels during the first part of the day.

Diabetic foot ulcers and amputations: estimates of health utility for use in cost-effectiveness analyses of new treatments.

OBJECTIVES: Diabetic foot ulcers (DFU), infections and amputations are associated with high costs of care and loss of health. To evaluate new treatments, both the extra costs incurred and the health utility gained need to be examined. However, evaluations of treatments in diabetes are hampered by the lack of utility values for health states such as DFU. We estimated utility values for health states seen amongst DFU patients. METHODS: We identified 13 unique health states based on presence/type of DFU and amputation. Members of the general public (n=107) received a description of each health state. They were then asked to indicate how undesirable each health state was (using the time trade-off method). Each answer was then transformed to create a value representing the "utility" of the health state, the utility value represented on a 0-1 scale. RESULTS: Valid responses could be obtained from 96 persons. Mean values included: 0.84 (diabetes with no DFU or amputation), 0.75 (uninfected DFU, no amputation), 0.68 (no DFU, previous foot amputation), and 0.63 (uninfected DFU, previous amputation of other foot). The impact of an ulcer depended on amputation status. CONCLUSIONS: Our values correspond with previously published results but are more detailed. In addition, since our values were derived from the general public, economic evaluations that incorporate them will use the generally preferred societal perspective. Therefore, these values are appropriate, practical and sensitive weights to calculate QALYs for cost-effectiveness analyses of foot ulcer treatments.

[Metformin associated lactic acidosis--case reports and literature review]. / Metforminassosiert laktacidose--pasienteksempel og litteraturgjennomgang.

BACKGROUND: The use of metformin in the treatment of diabetes mellitus type II is increasing. The drug has several advantageous metabolic effects, and is considered safe if not used in the presence of contraindications, in particular renal failure. MATERIAL AND METHODS: We present a patient with metformin associated lactic acidosis, to remind of a potentially lethal adverse reaction. We also review the literature about incidence and risk, prognosis and treatment of the disease. RESULTS: Our patient was a 72 year old woman with diabetes mellitus type II treated with metformin, who presented with acute renal failure, severe metabolic acidosis and circulatory failure. Treatment with bicarbonate buffer and vasopressors did not improve her condition, only after hemodialysis was her situation stabilised. INTERPRETATION: Metformin associated lactic acidosis must be considered in obscure metabolic acidosis in diabetic patients. The single most important therapeutic approach appears to be immediate hemodialysis.

Sequestration patterns of transfused rat neutrophilic granulocytes under normal and inflammatory conditions.

The fate of polymorphonuclear neutrophilic granulocytes (PMN) after their mobilization from the bone marrow of healthy individuals is not clearly understood. It has been suggested that there is a continuous utilization of these cells in widespread, subclinical inflammatory foci, where they are ultimately degraded. The goal of the present experiments was to determine whether an alternative ecotaxis ("homing") exists, namely sequestration and degradation of PMN by mononuclear phagocytes exposed to the bloodstream in the liver, spleen and bone marrow. Blood PMN were collected from donor rats, labelled with 51 Cr, and injected i.v. into 2 syngeneic rats, one of them having an induced sterile peritonitis. After various time intervals up to 18 h, the rats were killed and exsanguinated. As expected, we found cell-bound radioactivity in liver, spleen, and bone marrow. The bone marrow uptake of PMN appeared to be much lower in the inflammation rats than in the normal controls. These findings were confirmed in PMN transfer experiments using PVG rats congenic for the RT7 alloantigenic system. Here, transfused blood leukocytes were traced with fluorescent, monoclonal HIS41 antibodies and flow cytometry. A possible corticosteroid effect on the bone marrow sequestration could not be substantiated. Uptake and degradation of PMN takes place in organs containing phagocytes exposed to the bloodstream. Sequestration of PMN in the bone marrow is apparently down-regulated in inflammatory states, perhaps increasing the PMN availability to inflamed tissue.