Morphological characteristics of the superior cerebellar artery.

With the introduction of new techniques in diagnostic and interventional radiology and progress in micro neurosurgery, accurate knowledge of the brain blood vessels is essential for daily clinical work. The aim of this study was to describe the morphological characteristics of the superior cerebellar artery and to emphasize their clinical significance. In this study we examined radiographs of 109 patients who had CT angiography at the University Clinic for Radiology in Skopje, R. Macedonia. This study included 49 females and 60 males, ranging in age from 27 to 83 years; mean age 57.4 ± 11.8 years. In 105 patients SCA arose from the basilar artery on both sides as a single vessel. In two patients SCA arose as a duplicate trunk from the basilar artery. We found unilateral duplication on the right SCA in one patient, and bilateral duplication in one patient. In two patients was noticed origin of the SCA from PCA as a single trunk from adult type of the PCA. Through knowledge of the anatomy and variations of SCA is important for clinicians as well as basic scientists who deal with problems related to intracranial vasculature in daily basis for save performance of diagnostic and interventional procedures.

Body mass index, underweight and overweight in children 3 to 5 years of age from Skopje.

UNLABELLED: The aim of this research is to present body mass index (BMI) data in children 3-5 years of age from Skopje and provide the information on the prevalence of different categories of nutritional status during the early childhood. MATERIAL AND METHODS: The study included 420 preschool children (210 boys and 210 girls). Stature and body weight were measured, and the BMI value was calculated. Twelve anthropometric parameters were measured using standard equipment and measurement technique according to the International Biological Programme. RESULTS: The majority of anthropometrical parameters have shown significant age and sex specific differences in favor of male subjects. Values at the 50(th) percentile in our male subjects aged 3, 4 and 5 years for the weight-for-age index were 19 kg, 19.1 and 21 kg, respectively whereas in the female subjects the corresponding values were 16.8 kg, 20 kg and 21 kg. The height-for-age index values corresponding to the 50(th) percentile showed slightly higher values in our male subjects (100 cm, 109.5 cm and 116 cm) than those in our female subjects (102 cm, 108.5 cm and 116 cm). The values of 50(th) percentile of BMI in our males subjects were 18.1 kg/m(2), 16.2 kg/m(2) and 16 kg/m(2) whereas in our females were 16.5 kg/m(2), 16.7 kg/m(2) and 16.4 kg/m(2). CONCLUSION: These results show that underweight is a health problem of the rising generation in Skopje and needs to be considered along with the problem of overweight. It is recommended that the detected values could be applied for evaluation of deviations in growth and nutritional status in children aged 3-5.

Morphological characteristics of the first part of the vertebral artery.

Because of their anatomical localization, vertebral arteries were neglected in research for a long period of time. Vertebral arteries are responsible for about 30% of the brain blood supply. The aim of this study was to examine the vertebral artery's course in the first segment, and to define the anatomic variations and percentage of their appearance in the adult population using CT angiography. The data derived from this study may find useful application in a wide range of medical fields, such as anatomy, radiology and surgery. For that purpose during a 6-month period we examined 30 patients with CT angiography. The origin of the vertebral artery in all 30 patients was from the subclavian artery. The diameter of the left vertebral artery was from 1.6-5.20 mm., average 3.35 mm. The diameter of the right vertebral artery was from 1.64-5.40 mm., average 3.19 mm. Hypoplasia of the vessel was found in four patients. We found no aplasia of the vessel in this series. A contorted course was found in 12 (40%) patients. In all 30 (100%) patients the vertebral artery entered the foramen transversum at the level of the sixth cervical vertebra. Although the incidence of anatomical variations is rare, their presence is significant in the diagnostic and surgical procedures in the head and neck region. Insufficient knowledge can lead to serious iatrogenic injures.

Basilar artery fenestration.

The posterior circulation of the brain constitutes the vertebrobasilar system and its branches, which are responsible for about 30% of the brain's blood supply. The aim of this study was to describe the anomalies of the basilar artery, especially fenestrations. For that purpose, we examined 50 patients with computed tomography (CT) angiography during an 8-month period. In the CT reports of 2 (4%) patients of the 50 analysed, fenestration was found at the proximal basilar trunk. The two fenestrations in our series were not associated with aneurysms. No collateral branches originated from the two limbs of the fenestration. In conclusion, basilar artery fenestrations are a rare finding. The data derived from this study are useful teaching material for anatomists, and for the radiologists and neurosurgeons they are important for diagnostic and intervention procedures such as CT, magnetic resonance imaging, angiography, and surgical and endovascular procedures.

Dimensions of the triangle of Koch.

Dimensions of the triangle of Koch varied among the patients. The aim of this study was to present the dimensions of the triangle, and to compare the data obtained directly by post mortal measurement, using two different methods, and indirectly using mathematic formulas. The examination was performed in two independent groups consisting of 50 specimens each. Results showed that the mean value of area of the triangle of Koch obtained by the first type of post mortal measurement was significantly different from the mean value obtained using mathematic formulas (261.65 +/- 52.30 mm2 vs 116.74 +/- 13.20 mm2; p=0.00; p<0.05). But the mean value of the second type of the measurement was very similar to the mathematically obtained data (126.33 +/- 23.71 mm2 vs 116.74 +/- 13.20 mm2; p=0.278; p>0.05) (Fig. 1, Ref. 10).

Dimensions and muscular architecture of the triangle of Koch.

The variability in the arrangement of the superficial atrial muscle fibers in the areas of the triangle of Koch may be one of the factors influencing the route for impulses entering the AV node. The purpose of this study was to present the dimensions of the triangle of Koch and to describe the arrangement of the subendocardial atrial muscle fibers that form the approaches to the AV node, in and around the area of the triangle of Koch. The examination was made on 50 human hearts got obtained after autopsies of patients older than 18 years, died from no cardiac reasons, and fixed in 10% formaldehyde. The dimensions of the triangle of Koch were measured using the caliper. For the analyzing of the arrangement of the subendocardial muscle fibers, the right atrium was divided into four areas and the atrial endocardium was carefully peeled. The mean value of the area of the triangle of Koch (P) was 261.65 +/- 52.30 mm2 (min 160.00; max 375.00), the length of side a, was 24.14 +/- 14.2.53 mm (min 18; max 29), side b, was 20.12 +/- 2.42 mm (min 15; max 25) and side c, was 25.80 +/- 2.83 mm (min 20; max 31). The analyzing of the arrangement of the subendocardial superficial muscle fibers showed that 36 of the specimens had approximately precise patterns of fiber orientation within the areas of the right atrium. Variations in the fiber orientation were observed in 14 specimens. The knowledge of the anatomic features, dimensions and the architecture of the subendocardial muscle fibers of the triangle of Koch is the essential for both successful investigation and interpretation of the electrophysiological basis of heart dysrithmic diseases.

Transcriptional regulation of the vitamin D(3) receptor gene by ZEB.

The hormone 1,25-dihydroxyvitamin D(3) influences the growth and differentiation of a number of cell types. The functions of 1,25-dihydroxyvitamin D(3) are mediated through the vitamin D(3) receptor (VDR); therefore, an understanding of the regulation of VDR expression is important when considering the molecular mechanisms of differentiation induced by vitamin D(3) and its analogues. ZEB, a Krüppel-type transcription factor known to repress the transcription of several genes, binds to two sites within the VDR promoter and activates the transcription of this receptor in a cell-specific manner. Transfection of ZEB into SW620 colon carcinoma cells results in an up-regulation of the expression of endogenous VDR, confirming the role of ZEB in the transcriptional activation of the VDR gene. The expression of VDR is also induced by c-MYB; thus, ZEB and c-MYB may modulate the levels of VDR expression during differentiation in embryonal development, as well as in cancer cells.

HuD, a neuronal-specific RNA-binding protein, is a putative regulator of N-myc pre-mRNA processing/stability in malignant human neuroblasts.

N-myc gene copy numbers and transcription rates are similar in N (neuroblastic, tumorigenic) and S (non-neuronal, non-tumorigenic) neuroblastoma cells with chromosomally integrated amplified N-myc genes. However, N cells show significantly higher N-myc mRNA levels than S cells. Therefore, post-transcriptional control of N-myc gene expression must differ between these cell types. Since no differences in N-myc mRNA half-life were found between N and S cells from two cell lines, steady-state levels of N-myc pre-mRNA processing intermediates were analysed. Results suggest that the differences in N-myc expression arise primarily at the nuclear post-transcriptional level. The neuronal-specific RNA-binding Hu proteins are present in cytoplasmic and nuclear fractions of N cells and one of them, HuD, binds specifically to both exonic and intronic N-myc RNA sequences. In sense and antisense HuD-transfected N cells, there are coordinate changes in HuD and N-myc expression levels. Thus, we propose that HuD plays a role in the nuclear processing/stability of N-myc pre-mRNA in N-type neuroblastoma cells.

Cell lineage and differentiation state are primary determinants of MYCN gene expression and malignant potential in human neuroblastoma cells.

Neuroblastoma cell lines typically exhibit multiple cell phenotypes, counterparts of those comprising the embryonic neural crest. Expression of the MYCN gene, usually amplified in cell lines, differs markedly among the various differentiation phenotypes. Whereas neuroblastic (N-type) and stem cell (I-type) sublines have abundant MYCN RNA and protein, S-type cells (nonneuronal neural crest precursors) have a 4- to 9-fold lower level of cytoplasmic mRNA and a 2- to 36-fold lower protein content. N and S sublines with chromosomally integrated MYCN genes have similar gene copy numbers. Thus, in these S cells, MYCN expression is downregulated. Nuclear run-on and mRNA stability assays have revealed similar transcription rates and mRNA half-lives in N and S cells from two cell lines, indicating that downregulation occurs posttranscriptionally prior to mRNA degradation in the cytoplasm. S-type cells derived from double minute chromosome-containing lines show 4- to 10-fold lower gene copy numbers than N counterparts. Experimental induction of differentiation to neuronal/neuroendocrine or to S-type cells results in a marked reduction of MYCNexpression and, in double minute chromosome-containing N-type sublines, in gene loss as well. Malignant potential as indicated by soft agar growth capacity and tumor formation in nude mice is markedly diminished in S cells and, generally, is directly proportional to MYCN mRNA levels. The most plausible relationship suggested by our data is that MYCN expression, regulated by cell lineage and/or differentiation state, directly modulates the malignant potential of human neuroblastoma cells.

HuD, a neuronal-specific RNA-binding protein, is a potential regulator of MYCN expression in human neuroblastoma cells.

HuD is one of a family of neural antigens recognised by the sera of patients with antibody-associated paraneoplastic encephalomyelitis. Localised exclusively to neurons, these proteins are among the earliest markers of the developing nervous system. Sequence analysis suggests that HuD is an RNA-binding protein. Hu protein levels were determined for the three cell types characterising human neuroblastoma cell lines: sympathoadrenal neuroblasts (N), substrate-adherent Schwann/glial/melanoblastic precursors (S) and stem cells (I) which can give rise to both N and S cells. Western blot analysis showed similar levels of protein in three N-type cell lines; S cells have no detectable Hu protein. Northern blot analysis indicated that N cells express all three Hu genes, HuD, HuC and Hel-N1. N cells, mostly from MYCN-amplified cell lines, have consistently higher steady-state levels of MYCN mRNA than S cell counterparts. Nuclear run-on and mRNA half-life experiments revealed no differences in transcription rate or mRNA stability between N and S cells from the LA-N-1 cell line, implicating differences in post-transcriptional regulation. HuD is postulated to be instrumental in splicing/processing and/or stabilisation of mRNAs involved in cell growth and neuronal differentiation. As determined by gel-mobility shift assays, HuD fusion protein binds to the 3'UTR of human MYCN mRNA. Analysis of HuD deletion mutants has demonstrated that the first and second RNA-recognition motifs (RRMs) are required for binding. Whether HuD regulates MYCN expression and thereby influences tumour aggressiveness is of major interest.

[Properties, production, and practical uses of alkaline phosphatase]. / Svoistva, poluchenie i prakticheskoe primenenie shchelochnoi fosfatazy.

Literary data concerning the properties, isolation, purification and practical applications of alkaline phosphatase isolated from different sources are reviewed with special reference to the macromolecular structure and action mechanism of the enzyme in the reactions of phosphomonoester hydrolysis. The practicality of alkaline phosphatase as a helpful tool in conducting enzyme-linked immunoassays is demonstrated.