Grzegorz Bajor

Nesfatin-1, a unique regulatory neuropeptide of the brain

Nesfatin-1, a newly discovered NUCB2-derived satiety neuropeptide is expressed in several neurons of forebrain, hindbrain, brainstem and spinal cord. This novel anorexigenic substance seems to play an important role in hypothalamic pathways regulating food intake and energy homeostasis. Nesfatin-1 immunoreactive cells are detectable in arcuate (ARC), paraventricular (PVN) and supraoptic nuclei (SON), where the peptide is colocalized with POMC/CART, NPY, oxytocin and vasopressin. The nesfatin-1 molecule interacts with a G-protein coupled receptor and its cytophysiological effect depends on inhibitory hyperpolarization of NPY/AgRP neurons in ARC and melanocortin signaling in PVN. Administration of nesfatin-1 significantly inhibits consumatory behavior and decreases weight gain in experimental animals. These recent findings suggest the evidence for nesfatin-1 involvement in other important brain functions such as reproduction, sleep, cognition and anxiety- or stress-related responses. The neuroprotective and antiapoptotic properties of nesfatin-1 were also reported. From the clinical viewpoint it should be noteworthy, that the serum concentration of nesfatin-1 may be a sensitive marker of epileptic seizures. However, the details of nesfatin-1 physiology ought to be clarified, and it may be considered suitable in the future, as a potential drug in the pharmacotherapy of obesity, especially in patients treated with antipsychotics and antidepressants. On the other hand, some putative nesfatin-1 antagonists may improve eating disorders.

Cephalic Index in the First Three Years of Life: Study of Children with Normal Brain Development Based on Computed Tomography

Cephalic index is a highly useful method for planning surgical procedures, as well as assessing their effectiveness in correcting cranial deformations in children. There are relatively very few studies measuring cephalic index in healthy Caucasian young children. The aim of our study was to develop a classification of current cephalic index for healthy Caucasian children up to 3 years of age with normal brain development, using axial slice computer tomography performed with very thin slices (0.5 mm) resulting in more accurate measurements. 180 healthy infants (83 females and 97 males) were divided into 5 age categories: 0–3, 4–6, 7–12, 13–24, and 25–36 months. The average value of cephalic index in children up to 3 years of age amounted to 81.45 ± 7.06. The index value in case of children under 3 months was 80.19, 4 to 6 months was 81.45, 7 to 12 months was 83.15, in children under 2 years was 81.05, and in children under 3 years was 79.76. Mesocephaly is the dominating skull shape in children. In this study, we formulated a classification of current cephalic indices of children with normal brain development. Our date appears to be of utmost importance in anthropology, anatomy forensic medicine, and genetics.

Clinical significance of knowledge about the structure, function, and impairments of working memory

A review of contemporary research on the working memory system (WMS) is important, both due to the need to focus the discussion on further necessary investigations on the structure and function of this key part of the human brain, as well as to share this knowledge with clinicians. In our introduction we try to clarify the actual terminology and provide an intuitively understandable model for 3 basic cognitive operations: perception, recognition, imagery, and manipulation of recalled mental images. We emphasize the importance of knowledge of the structure and function of the WMS for the possibility to demonstrate the links between genetic polymorphisms and the prevalence to some mental disorders. We also review current knowledge of working memory dysfunction in the most common diseases and specific clinical situations such as maturation and aging. Finally, we briefly discuss methods for assessment of WMS capacity. This article establishes a kind of compendium of knowledge for clinicians who are not familiar with the structure and operation of the WMS.

Nasal Region Dimensions in Children: A CT Study and Clinical Implications

Atresias of nasal cavity, especially in young children, pose an essential problem in childrens otolaryngology. Only a few morphometric studies of nasal cavity concerning healthy neonates and young infants without nasal stenosis are available. Multislice computed tomography is a perfect tool enabling a precise evaluation of anatomic structures. The aim of this study was a complex morphometric evaluation of clinically important bone and mucosal structures of nasal cavity and examination of their dependence on age and sex in children up to 3 years of age. 180 children, age range 0–3 years, were divided into 5 age groups, and measurements of 18 distances between skeletal structures and between mucosal structures of nasal cavity were performed on their CT scans. A correlation between the widths of selected bone structures was examined. There were no statistically significant differences in analyzed morphometric parameters between adjacent age groups. The differences were statistically significant only between extreme age groups. There was a correlation between evaluated structures and age. Our results are a valuable supplement of nasal cavity morphometric data of young children. They may be useful in setting reference values of evaluated parameters in children and in diagnosis and planning of surgical treatment in childrens otolaryngology.

Female and male orbit asymmetry: Digital analysis

BACKGROUND Standard anthropometric methods applied to measurements of the skull differentials are laden with mistakes stemming from the way the measuring devices are built and from a lack of experience on the part of the researchers. To increase objectivity, digital imaging measurements via computer systems were introduced. OBJECTIVES The aim of this research was to assess the asymmetry of the male and female orbit with the application of the new graphic methods: raster graphics and vector graphics. MATERIAL AND METHODS The examination was conducted on 184 well-preserved skulls. The photos were taken by a digital camera with high definition. Orbit asymmetry was examined by determining the distance between the centers of gravity of both orbits and the frontal median line d1 and d2. Then angles α and β were appointed. They are defined as angles between the line that runs through craniometrical points mf and ek on the right side (angle α) and on the left side (angle β), and the frontal median line at their crossing point. Distances r2 and r1, which are allocated points between the frontal median lines (LPP), were also set. RESULTS Angles α and β were also analyzed while comparing the skulls of both genders. Statistically significant differences were only observed in male skulls. However, differences for both genders were noted in parameters d1 and d2. No statistically significant differences were discovered between men and women for parameters r1 and r2. The groups of women and men were merged, being treated as a population; which resulted in the conclusion that there are no statistically significant differences between these parameters. CONCLUSIONS The skulls asymmetry connected to gender and the asymmetry of the right and left sides of examined craniums can be used in criminal examinations as well as in facial reconstructive surgeries.

Feasibility and accuracy of new insertion technique of S1 transpedicular screw. Computed tomography-based morphometric analysis

OBJECTIVE To assess feasibility and accuracy of a new insertion technique of S1 transpedicular screw. SUMMARY OF BACKGROUND DATA Transpedicular stabilization in the first sacral vertebra (S1) is a technically demanding surgical procedure with inherent risk of loosening of the implant. A modification of the technique was recently proposed, along with the analytical verification which was performed based on the available literature. In the study, we performed radiological assessment of screws inserted into the S1 using the classical and modified techniques. METHODS The analysis was performed in two parts. The first part was performed on eight cadaver specimens after implantation of the screws. In the second part, we used computed tomography images of patients with degenerative disk disease with a superimposed representation of screws. The thickness of the posterior cortex adherent to the screws, screw trajectory and their position with regard to the spinal canal was measured. The area of posterior cortex in contact with the screws was also calculated. RESULTS The contact length and area was found to be two times greater for screws introduced with the modified technique. The convergence angle was comparable between the techniques, despite the shift of entry point. There was no canal breach, although with the modified technique the screws passed closer to the spinal canal. CONCLUSIONS The modified technique is considered safe. In this technique, the screws pass through a thicker portion of the posterior cortex compared to the classical technique that aims at improving the stability of the fixation.

Orbital Opening Shape and Its Alphanumerical Classification.

BACKGROUND Orbit is the one of the most complicated areas of the facial part of cranium. The anthropological analysis of the orbits comprises basic measurement characterizing their shape: width and height. Classic anthropometric methods used to measure the skull variability are burdened with mistakes resulting from construction of measuring devices as well as from researchers experience. OBJECTIVES The purpose of our research was to introduce a metric classification of the orbital opening. MATERIAL AND METHODS The study was carried out on 184 skulls. In our study we suggest introducing a classification of the orbital opening shape by calculating a functional for the 15 categories of the orbit shape. Shape categories have been arranged following the increasing value of the functionals. Each shape category of the orbital opening, according to the Piaseckis descriptive classification, was assigned a letter from the alphabet. RESULTS We have observed a greater number of symmetrical skulls in the female group (29.11%) than in the male (23.81%). In both groups the symmetry type AA was the most frequent, it corresponds to the value of functional comprised in the interval from 0 to 1,30. According to the Piaseckis descriptive classification it was the oval elongated type. CONCLUSIONS Our alphanumerical classification based on the value of functional and on the orbit outline assigned to the value is an objective and useful method of the orbital opening shape analysis.

Biomechanical analysis of the durability of a modified S1 vertebrae transpedicular screws insertion technique

Background: One of the most important elements of the transpedicular screw implantation technique, which enables a strong screw‐bone interface, is the precise choice of the site of screw insertion and the screws trajectory. Due to the complex biomechanics of the lumbosacral interface and different shape of the sacrum, fixation of this segment remains a challenge for surgeons. Because of this, Kubaszewski et al. proposed a modified technique in which the entry point for screw insertion in the S1 vertebra is changed. Methods: Six human cadaver specimens of the S1 vertebrae were examined. Two transpedicular screws were inserted into the body of each examined vertebra using two implantation methods with different screw entry points and trajectories. The screws were subjected to cyclic preloading, followed by the pull‐out test. The ultimate pull‐out force, displacement, stiffness, and failure energy were measured. Findings: The average pull‐out force obtained for the standard method of implantation was 498 N (SD 201), whereas for the modified technique, it was 1308 N (SD 581). Displacement of the inserted screws in the new method was 36% higher than in the case of the standard method. This method is also characterized by the greater stiffness of the obtained interface and greater failure energy than the normally used technique. Interpretation: The obtained results demonstrate that the use of the new technique of implantation significantly increases the strength of the obtained screw‐bone interface. It should also increase the success rate of the performed fixations and increase the safety of such fixations in clinical practice.

Neointima development in externally stented saphenous vein grafts

Introduction The main limitation of coronary artery bypass grafting (CABG) is rapid neointimal hyperplasia leading to graft failure. Aim To assess plaque formation in saphenous vein grafts (SVG) covered by an external Dacron stent in comparison with the classical technique. Material and methods In the study group vein grafts covered by external stent mesh made of Dacron were implanted. An intravascular ultrasonography (IVUS) study was performed in 35 aorto-coronary SVG covered by an external Dacron stent and in 64 normal SVG during the first year after CABG. In each SVG 25 mm of good quality IVUS image, volumes of lumen, plaque (neointima), outer border of the vein graft (external SVG) and adventitia were calculated in three time periods: 0–130 days, 130–260 days and 260–390 days. Results Between the first and second time period, lumen volume (mm3) was reduced from 10.33 ±4.4, to 6.80 ±2.23 in the second period and 5.69 ±1.26 in the third one. This effect was much less marked in normal grafts. The corresponding lumen volume (mm3) was: 10.90 ±3.9, 9.15 ±2.94 and 8.92 ±2.93 in consecutive time periods. Plaque volume (mm3) did not change in control grafts during the course of the study, but it increased very significantly in stented grafts from 0.86 ±1.24 in the first period to 2.70 ±1.58 in the second and 3.29 ±2.66 in the third one. Conclusions The experimental technique of implanting SVG covered with an external elastic Dacron stent seems to be inferior to traditional ones. This is probably due to the more complicated process of vein implantation and higher micro-injury occurrence during the surgery.

Comparative Study on Human Cartilage in Laryngological Transplantation Surgery Purposes by Means Confocal Fluorescence Microscope – Primary Study

Five sources of healthy human cartilage tissue were investigated using fluorescence confocal microscope: larynx, meniscus, nose, joint and ear. The structural qualitative comparison carried out a maximum number of chondrocytes is present in nose and ear. Laser induced fluorescence using 404 nm wavelength source and statistical comparison shown extracellular matrix is similar in larynx, meniscus and nose cartilage. The biggest differences appeared in joint and ear tissue. This beginning study is promising and shows useful application in reconstructive surgery and oncology.