Increased cerebrospinal fluid tau protein in multiple sclerosis

Axonal damage is now being recognized as a common finding in multiple sclerosis (MS) lesions and a cause of irreversible neurological damage. Attempts to identify markers of early axonal damage are of great significance. This prompted us to examine the microtubule-associated protein tau in the cerebrospinal fluid (CSF) of patients with MS vs. controls. Tau was measured by double antibody sandwich ELISA. Increased CSF tau levels were found in MS as compared to controls (medians 249.6 and 135 pg/ml respectively, p<0.001). Half of the MS patients presented with levels above the upper limit of the controls. A significant increase vs. controls was found in both relapsing-remitting and progressive subtypes. These data may indicate axonal impairment in a subpopulation of MS patients and may provide a tool for the estimation of axonal damage during life.     

Impaired generation of bone marrow CD34-derived dendritic cells with low peripheral blood subsets in patients with myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a stem cell disorder characterized by ineffective haematopoiesis and blood cytopenias. The present study investigated the potential of bone marrow CD34(+) progenitors in MDS patients to proliferate and differentiate into dendritic cells (DCs) in a cytokine-supplemented liquid culture system and analysed the status of blood DC subsets in these patients. CD34(+) progenitors had low potential to generate DCs in vitro, as the number of DCs obtained from one CD34(+) cell was significantly lower compared with controls (median value 0.2 vs. 4, P = 0.003). In patients, the survival and proliferation of CD34(+) cells in culture was not correlated to the degree of apoptosis. Phenotypically and functionally CD34(+)-derived DCs were similar in MDS patients and normal subjects. The percentage of both circulating DC subsets in patients was extremely diminished compared with controls (myeloid DC: 0.10 +/- 0.10% vs. 0.35 +/- 0.13%, P < 0.001; plasmacytoid DC: 0.11 +/- 0.10% vs. 0.37 +/- 0.14%, P < 0.001). In cases with the 5q deletion both CD34-derived DCs and blood DCs harboured the cytogenetic abnormality. Our results indicate that, in MDS, the production of DCs is affected by the neoplastic process resulting in ineffective 'dendritopoiesis' with low blood DC precursor numbers. This quantitative DC defect probably contributes to the poor immune response against infectious agents and to the escape of the malignant clone from immune recognition with disease progression towards acute leukaemia.     

Attachment relationships of adolescents who spent their infancy in residential group care: The Greek Metera study

A prospective longitudinal study beginning whilst the infants were living in the Metera Babies Centre showed that the great majority showed a disorganized attachment during the period of residential care, even though neither abuse/neglect nor subnutrition were involved. There was an initial follow-up post-adoption age at four years. This paper concerns a further follow-up of the 52 adopted adolescents aged 13 years who had spent their first two years of life in Metera Babies Centre. They were compared to 36 adolescents reared in their biological families who, during their infancy, attended full-time public day care. The key aim was to examine continuities and discontinuities between early and contemporary relationships. The Child Attachment Interview was employed in adolescence. The main findings were a significant decrease in the rate of disorganization and a lack of a significant difference between the previously institutionalized group and the family care comparison group on attachment qualities in adolescence. There was not sufficient statistical power, however, to detect a small difference.     

Screening performance of different methods defining fetal nasal bone hypoplasia as a single and combined marker for the detection of trisomy 21 in the second trimester

Objective: To evaluate different methods of defining fetal nasal bone hypoplasia in the second trimester for the detection of trisomy 21.

Methods: Prospective study in Greek women undergoing anomaly scan between 18?+?0 and 23?+?6 weeks. The following methods of defining nasal bone hypoplasia were evaluated, either as a single marker or in combination with others: (1) BPD to nasal bone length (NBL) ratio; (2) multiples of the median (MoM) of NBL, according to normal curves from a Greek population; (3–4) NBL?<?2.5 percentile according to normal curves (3) commonly used internationally curves and (4) curves from a Greek population.

Results: In total, 1301 singleton fetuses were evaluated???10 with trisomy 21. The best detection rate of trisomy 21 was achieved when the applied method was nasal bone percentiles adjusted to maternal ethnicity, in combination with other markers (<2.5 percentile according to normal curves from a Greek population; p?<?0.001; sensitivity 50%; specificity 94.8%; false-positive rate 5.2%; positive likelihood ratio 9.6).

Conclusion: Screening performance of fetal nasal bone hypoplasia in detecting trisomy 21 varies according to the method applied. The best screening performance is achieved by using percentiles adjusted to maternal ethnicity in combination with other markers of aneuploidy.     

Mutant polycystin-2 induces proliferation in primary rat tubular epithelial cells in a STAT-1/p21-independent fashion accompanied instead by alterations in expression of p57KIP2 and Cdk2

Background

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is characterized by the formation of multiple fluid-filled cysts that destroy the kidney architecture resulting in end-stage renal failure. Mutations in genes PKD1 and PKD2 account for nearly all cases of ADPKD. Increased cell proliferation is one of the key features of the disease. Several studies indicated that polycystin-1 regulates cellular proliferation through various signaling pathways, but little is known about the role played by polycystin-2, the product of PKD2. Recently, it was reported that as with polycystin-1, polycystin-2 can act as a negative regulator of cell growth by modulating the levels of the cyclin-dependent kinase inhibitor, p21 and the activity of the cyclin-dependent kinase 2, Cdk2.

Methods

Here we utilized different kidney cell-lines expressing wild-type and mutant PKD2 as well as primary tubular epithelial cells isolated from a PKD transgenic rat to further explore the contribution of the p21/Cdk2 pathway in ADPKD proliferation.

Results

Surprisingly, over-expression of wild-type PKD2 in renal cell lines failed to inactivate Cdk2 and consequently had no effect on cell proliferation. On the other hand, expression of mutated PKD2 augmented proliferation only in the primary tubular epithelial cells of a rat model but this was independent of the STAT-1/p21 pathway. On the contrary, multiple approaches revealed unequivocally that expression of the cyclin-dependent kinase inhibitor, p57^KIP2, is downregulated, while p21 remains unchanged. This p57 reduction is accompanied by an increase in Cdk2 levels.

Conclusion

Our results indicate the probable involvement of p57^KIP2 on epithelial cell proliferation in ADPKD implicating a new mechanism for mutant polycystin-2 induced proliferation. Most importantly, contrary to previous studies, abnormal proliferation in cells expressing mutant polycystin-2 appears to be independent of STAT-1/p21.     

Selective benefits of simvastatin in bitransgenic APPSwe,Ind/TGF-β1 mice

Cognitive and cerebrovascular deficits are 2 landmarks of Alzheimer's disease (AD) to target for effective therapy. Here, we evaluated the efficacy of simvastatin in bitransgenic A/T mice overexpressing a mutated form of the human amyloid precursor protein (APP_Swe,Ind) and a constitutively active form of transforming growth factor-β1. These mice feature the AD amyloid beta (Aβ) and cerebrovascular pathology. Simvastatin significantly decreased insoluble Aβ peptide levels and Aβ plaque load despite no effect on β-site amyloid precursor protein-cleaving enzyme and Aβ-degrading enzyme neprilysin protein levels. However, simvastatin failed to improve spatial learning and memory deficits and the decreased baseline levels of the memory-related protein early growth response-1 (Egr-1) in the hippocampus CA1 area. The impaired hyperemic response to whisker stimulation in A/T mice was not improved with treatment, but simvastatin fully restored constitutive nitric oxide synthesis in vessel walls and exacerbated agonist-mediated dilatory deficits. These findings point to the efficacy of simvastatin on selective AD features in a complex model of the disease, likely reflecting the challenges faced by recent clinical trials in assessing statin efficacy.     

Defective growth hormone secretion in primary microcephaly

The 24 hr variations of plasma growth hormone (GH) and/or GH secretion provoked by oral glucose load or by insulin-induced hypoglycemia were studied in five microcephalic children. Low levels of GH and, especially, complete lack of secretory episodes were detected in three of the five children, two of whom were brothers. GH deficiency may constitute the principal or a contributing factor of impaired growth in some microcephalic children. A possible association between the cerebral abnomality and the pituitary hypofunction is suggested. An analogy is made between the present cases and the neuroendocrine complexes reported as Kallmann's and de Morsier's syndromes, respectively.     

Greek employee awareness of carcinogenic exposure

BACKGROUND: Occupational risk factors contribute significantly to the development of lung cancer; however, little is known about the extent to which employees are informed of occupational exposure to carcinogenic substances. METHODS: Through a case-control study, we estimated the level of awareness among Greek employees potentially exposed to known carcinogenic substances within various occupational settings. RESULTS: Only 6.6% of men (n = 482) employed in occupations with potential exposure to carcinogenic substances were aware of such occupational exposures. Age, education, and residence were significantly associated with awareness. Employees having at least a secondary level of education were 3.5 times more aware than those having at most 6 years of educational training. CONCLUSIONS: Assessing awareness among workers potentially exposed to occupational risk factors and promoting occupational health education are important steps for increasing health and safety at the workplace.