Note: optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems

A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time.

[Papilledema of unknown cause]

Orbital metastases occur in 2-5 % of cancer patients. Common primary sites that cause orbital metastases are breast, lung and prostate cancer. In up to 25 % of patients orbital metastasis is the initial sign of an unknown primary tumor. Clinical symptoms are proptosis, ocular motility disorder and visual impairment. Imaging procedures may be useful in diagnosing orbital metastases but are not specific. Treatment is palliative. Radiotherapy, chemotherapy and surgical debulkment in selected patients are treatment options.

Phenylketonuria is not a risk factor for gut mucosa inflammation: a preliminary observation

BACKGROUND

Phenylketonuria (PKU) is an inborn error of amino acid metabolism in which high phenylalanine (Phe) concentrations in the central nervous system adversely affect its development and functioning. In PKU high oxidative stress and inefficiency of free radical scavenging may lead to systemic chronic inflammation. We hypothesised that in PKU gut mucosa is chronically inflamed and that this leads to release of calprotectin from neutrophils and monocytes.

AIM

The aim of this study was to compare intestinal mucosa inflammation status, as measured using fecal calprotectin, in patients with PKU irrespective of compliance, and healthy controls.

PATIENTS AND METHODS

Forty-four patients with classical PKU were included in the study (21 male, 23 female; aged 0-41 years; mean ± SEM: 16.5 ± 1.7 years). Forty-eight healthy subjects (HS) aged 9-68 years (29.4 ± 2.6 years) comprised the control group, of whom 21 were male and 27 female. Among PKU patients 25 had normal Phe blood concentrations and in 19 they were elevated. In all subjects calprotectin stool concentrations were assessed (PhiCal ELISA, Calpro, Lysaker, Norway).

RESULTS

Normal FC (fecal calprotectin) concentrations were found in 43 (97.7%) PKU patients and 46 (95.8%) HS. No correlation between dietary control of Phe blood concentrations and FC levels in PKU patients was found.

CONCLUSIONS

No detectable intestinal inflammation occurs in phenylketonuria. Lack of dietary control and elevated Phe levels do not seem to be risk factors for inflammation of the mucosa of the gut.

Compound heterozygosity of two functional null mutations in the ALPL gene associated with deleterious neurological outcome in an infant with hypophosphatasia

Hypophosphatasia (HPP) is a heterogeneous rare, inherited disorder of bone and mineral metabolism caused by different mutations in the ALPL gene encoding the isoenzyme, tissue-nonspecific alkaline phosphatase (TNAP). Prognosis is very poor in severe perinatal forms with most patients dying from pulmonary complications of their skeletal disease. TNAP deficiency, however, may also result in neurological symptoms such as neonatal seizures. The exact biological role of TNAP in the human brain is still not known and the pathophysiology of neurological symptoms due to TNAP deficiency in HPP is not understood in detail. In this report, we describe the clinical features and functional studies of a patient with severe perinatal HPP which presented with rapidly progressive encephalopathy caused by new compound heterozygous mutations in the ALPL gene which result in a functional ALPL "knock out", demonstrated in vitro. In contrast, an in vitro simulation of the genetic status of his currently asymptomatic parents who are both heterozygous for one mutation, showed a residual in vitro AP activity of above 50%. Interestingly, in our patient, the fatal outcome was due to progressive encephalopathy which was refractory to antiepileptic therapy including pyridoxine, rather than hypomineralization and respiratory insufficiency often seen in HPP patients. The patient's cranial MRI showed progressive cystic degradation of the cortex and peripheral white matter with nearly complete destruction of the cerebrum. To our knowledge, this is the first MRI-based report of a deleterious neurological clinical outcome due to a progressive encephalopathy in an infant harboring a functional human ALPL "knock out". This clinical course of disease suggests that TNAP is involved in development and may be responsible for multiple functions of the human brain. According to our data, a certain amount of residual TNAP activity might be mandatory for normal CNS function in newborns and early childhood.

Increased serum osteoprotegerin in patients with primary adrenal insufficiency receiving conventional hydrocortisone substitution

Patients treated for primary adrenal insufficiency (PAI) are at risk of steroid over-replacement, which may affect their skeleton. The study was aimed to investigate the effect of steroid substitution on serum osteoprotegerin and receptor activator of nuclear factor kappa-beta ligand (RANKL) levels in relation to bone mineral density (BMD) in PAI. Eighty patients (mean age 47.2±14.5 years, mean hydrocortisone dose 0.49±0.14 mg/kg/day) and 63 healthy subjects were included. Serum osteoprotegerin, RANKL, 25-hydroxyvitamin D₃, calcium, phosphate, alkaline phosphatase, intact parathormone, and dehydroepiandrosterone-sulfate levels were evaluated in patients and controls. BMD was assessed in affected subjects using dual-energy X-ray absorptiometry. Mean osteoprotegerin concentration in PAI patients appeared significantly higher vs. controls (p=0.002), while RANKL levels were similar (p=0.430). Serum osteoprotegerin increased with age (p<0.001), but showed no correlation with daily hydrocortisone dose. Osteoprotegerin was negatively correlated with serum dehydroepiandrosterone-sulfate (p=0.008) and with BMD at the lumbar spine (p<0.001) and femoral neck (p=0.003). RANKL correlated negatively with PAI duration (p=0.029) and positively with daily hydrocortisone dose (p=0.018). Lumbar spine osteoporosis and osteopenia were found in 12 and 31 patients, respectively, whereas in femoral neck: in 5 and 33 individuals. Patients with osteoporosis displayed higher osteoprotegerin levels, but after the age-adjustment the correlation was lost. In conclusion, increased osteoprotegerin in PAI might reflect a compensatory response to enhanced bone resorption due to exogenous steroid excess and/or result from a deficit in adrenal androgens. RANKL levels remain within normal range on standard steroid replacement.

Modified C-reactive protein selectively binds to immunoglobulins

Modified C-reactive protein (mCRP) has been reported to non-specifically bind to immunoglobulins; notwithstanding, the nature of these interactions is not clear. The aim of this study was to investigate the binding of antibodies directed against HSA and IgG to mCRP, fibrinogen (Fg), IgG, fibronectin (Fn) and C1q and its contaminants. We also studied the binding of mCRP to the antibodies directed towards receptors involved in CRP signalling (anti-CD32, anti-CD16). For the analysis of such interactions, a combination of ELISA and Western immunoblotting has been applied. The tested antibodies powerfully bound to either the contaminations of purified proteins (Fg, IgG, Fn and mCRP) or interacted directly with some of these proteins (C1q, mCRP, Fg). The effectiveness of anti-HSA binding to immobilized proteins was influenced by the antigenic specificity of the antibody, the content of various protein fractions in the contaminants of a given protein (albumin augmented the interactions), overall protein purity and a natural avidity of a given protein towards immunoglobulins. The relative binding of anti-HSA or anti-IgG to immobilized mCRP was considerably lower than that observed for plasma proteins. Furthermore, the strength of the direct interaction between immunoglobulins and mCRP varied from the lack of response (anti-HSA) or a negligible response (anti-IgG) to the relatively high signal (human IgG, anti-CD16, anti-CD32), as compared to the control. Based on these observations, we conclude that the binding of mCRP to immunoglobulins cannot be easily generalized as a kind of some universal phenomenon.

Prevotella nigrescens and Porphyromonas gingivalis are associated with signs of carotid atherosclerosis in subjects with and without periodontitis

BACKGROUND AND OBJECTIVE

Oral microorganisms may be involved in the development of cardiovascular diseases, and Porphyromonas gingivalis is one of the periodontal microorganisms that has been found in carotid atheroma. The aim of this work was to study subgingival microorganisms and early carotid lesions in subjects with and without periodontitis.

MATERIAL AND METHODS

Eighty-eight subjects with periodontitis and 40 subjects without periodontitis underwent dental examinations in 2003. The presence of the periodontal microorganisms Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia was analyzed from subgingival plaque using PCR amplification. The common carotid artery was scanned using ultrasound and the calculated intima-media area (cIMA) was measured. The association between periodontitis, the cIMA value and the presence of periodontal microorganisms, together with several confounders, was studied in a multiple logistic regression model.

RESULTS

Smoking [odds ratio (OR) = 5.64; p = 0.001), level of education (OR = 5.02; p < 0.05) and the presence of P. gingivalis (OR = 6.50; p < 0.05) were associated with periodontitis. Explanatory factors for the increased cIMA were periodontitis (OR = 4.22; p < 0.05), hypertension (OR = 4.81; p < 0.05), high body mass index (OR = 5.78; p < 0.01), male gender (OR = 3.30; p < 0.05) and poor socioeconomic status (OR = 4.34; p < 0.05). P. nigrescens (OR 4.08; p < 0.05) and P. gingivalis (OR 7.63; p < 0.01) also appeared as explanatory variables associated with increased cIMA values.

CONCLUSION

This cross-sectional study showed that P. nigrescens and P. gingivalis were significantly associated with increased cIMA values.

Adrenal hypoplasia congenita - an uncommon reason of primary adrenal insufficiency

Adrenal hypoplasia congenita (AHC) is a rare inherited condition characterised by primary adrenal failure and hypogonadotropic hypogonadism. Most cases arise from mutations in the NR0B1 gene (Xp21.3), which encodes an orphan nuclear receptor DAX-1. A 20-year-old patient was recently diagnosed with AHC. Adrenal failure had been recognized and treated since his infancy. During adolescence, gradual decrease in growth velocity and low body mass were noted. Lack of puberty and skeletal immaturity were observed. Serum DHEA-S and testosterone were undetectable. Low gonadotropin levels failed to rise after stimulation. Neither dysfunction of the somatotropic nor pituitary-thyroid axis was found and no hypothalamo-pituitary pathology was visible on MRI. Androgen replacement therapy induced the development of secondary sexual characteristics, remarkably improved patient's growth and advanced his bone age. NR0B1 mutation screening revealed nucleotide transversion C>A, resulting in premature stop codon (Y399X). Same mutation was previously identified in a Scottish family, however, phenotypic differences suggest the role of additional factors modifying the disease course. Although it does not change therapeutic strategy, accurate molecular diagnosis allows genetic counselling in family members. Autoimmunity remains the major cause of adrenal failure; however, other rare conditions should always be considered.

Association of the CYP27B1 C(-1260)A polymorphism with autoimmune Addison's disease

Autoimmune Addison's disease (AAD) is a complex endocrine disorder with several susceptibility loci. This study was aimed to investigate the associations of CYP27B1 C(-1260)A and PDCD1 G7146A polymorphisms with AAD in a Polish cohort, comprising 101 AAD patients and 251 healthy controls. CYP27B1 encodes 1alpha-hydroxylase, responsible for conversion of the vitamin D (3) precursor into its active form, involved in the immune function. PDCD1 gene gives rise to an inhibitory immune receptor, expressed on activated lymphocytes. Polymorphic variants of these genes had previously been associated with various autoimmune disorders. Genotyping was performed by PCR-RFLP method. The CYP27B1 C(-1260) allele appeared significantly more frequent in AAD compared to controls ( P=0.020), yielding an OR of 1.53 (95% CI 1.07-2.19). The distribution of C(-1260)A genotypes also demonstrated significant difference ( P=0.003). Stratification according to the presence of concomitant autoimmune disorders revealed an association of the C(-1260) allele with the polyendocrine cases of AAD ( P=0.031), while no significance was found for the isolated ADD compared with healthy controls ( P=0.253). Overall, the association between AAD and C(-1260)A was confirmed in a meta-analysis of 325 AAD patients and 952 controls from three different European populations. Under a fixed-effect model, C(-1260) allele and CC genotype were associated with AAD susceptibility with a pooled OR of 1.44 (95% CI 1.18-1.75) and 1.88 (95% CI 1.42-2.36), respectively. No differences were observed for the PDCD1 G7146A between affected subjects and controls (p>0.05). In conclusion, this study confirms the association of the CYP27B1 C(-1260)A polymorphism with AAD, whereas the contribution of PDCD1 G7146A seems less likely.