Medicina, Volume 49, Issue 4 (April 2013) – 8 articles

Ventricular septal defect after myocardial infarction is a rare but often life-threatening mechanical complication. The keys of management are a prompt diagnosis of ventricular septal defect and an aggressive approach to stabilize patient’s hemodynamics. Invasive monitoring, judicious use of inotropes and vasodilators, and an intra-aortic balloon pump are recommended for the optimal support of patient’s hemodynamics. The best results are achieved if optimally medically managed patients survive at least 4 weeks before elective surgery necessary for scar formation in a friable infarcted tissue. We report a case of acute myocardial infarction complicated by the rupture of ventricular septum. Instead of attempting an immediate surgical closure of ventricular septal defect, the postponed surgery was successfully performed 3 weeks after the occurrence of ventricular septal defect. Preoperatively, clinical and hemodynamic conditions of the patient were maintained stable with the support of an intra-aortic balloon pump and inotropes. Full article

Background and Objective. Although previous studies have provided new information on bone repair, there are still gaps in knowledge about resorptive and formative processes during bone repair at the electron microscopic level. The aim of this study was to compare bone repair after the internal fracture, osteotomy, and bicortical perforation of the tibia by means of electron microscopy.
Material and Methods. An electron microscopic study of bone repair after the internal fracture, osteotomy, and bicortical perforation of the tibia was performed on 72 male Wistar rats. Rats undergoing osteotomy and perforation were further subdivided into the control and immobilization subgroups. Bone repair was observed during the first posttraumatic weeks.
Results. Although bone repair in general had similar bone healing stages in all the groups, the repair process depended on the mode and degree of injury thus being different in the experimental groups. After the internal fracture, indirect ossification was observed; after osteotomy, primary periosteal, secondary endosteal ossification was noted; and after perforation, primary endosteal, secondary periosteal ossification was documented. Immobilization had an inhibitory effect on bone repair.
Conclusions. The results of the present study gave new information at the electron microscopic level about intracellular changes and intercellular matrix synthesis during different types of posttraumatic bone repair and confirmed our previous reports on similar posttraumatic bone repair in histomorphometric and immunohistochemical studies. Full article

Objective. The aim of this study was to estimate the significance of nasal potential difference (NPD) in the diagnosis of cystic fibrosis (CF) in children with clinical symptoms suggestive of the disease, positive sweat test results, and/or genetically confirmed diagnosis.
Material and Methods. NPD measurements according to the modifications by Alton were performed in 50 children with clinical CF symptoms supported by positive sweat test results, 50 children with other obstructive lung diseases, and 50 healthy children. A subgroup of 17 children with the diagnosis confirmed by 2 identified mutations in the CF transmembrane regulatory gene was analyzed individually.
Results. The mean NPD value recorded in 50 children with clinical symptoms of CF supported by positive sweat test results and/or genetic analysis was –28.0 mV [SD, 10.2]. The mean NPD value in the subgroup of children with 2 identified mutations in the CF gene (n=17) was more negative than in the subgroup of children with unrecognized mutations (n=33) (–37.1 mV [SD, 7.0] vs. –23.4 mV [SD, 8.3], P<0.001). The mean NPD value in patients with other obstructive lung diseases and healthy children was significantly more positive than in the group of CF children with positive sweat test results and/or identified mutations (–18.1 mV [SD, 3.6] and –15.5 mV [SD, 4.3] vs. –28.0 mV [SD, 10.2], P<0.001). The NPD cut point value for the genetically confirmed diagnosis of CF was –35.0 mV (sensitivity, 93.9%; specificity, 88.2%), while in general, the NPD prognostic value was –24.0 mV (sensitivity, 58.0%; specificity, 98.0%)
Conclusions. The NPD measurement is a valuable tool for the diagnosis of CF in children, but further studies are necessary to establish NPD values related to the CF genotype and to reduce the intrasubject variability of this test. Full article

Background and Objective. Variation of osteoporosis in the population is the result of an interaction between the genotype and the environment, and the genetic causes of osteoporosis are being widely investigated. The aim of this study was to analyze the association between the polymorphisms of the vitamin D receptor (VDR), type I collagen (COL1A1), and lactase (LCT) genes and severe postmenopausal osteoporosis as well as bone mineral density (BMD).
Material and Methods. A total of 54 women with severe postmenopausal osteoporosis and 77 controls (mean age, 58.3 years [SD, 6.2] and 56.7 years [SD, 7.42], respectively) were included into the study. The subjects were recruited at the City Center for Osteoporosis Prevention (Minsk, Belarus). Dual-energy x-ray absorptiometry was used to measure bone mineral density at the lumbar spine and the femoral neck. Severe osteoporosis was diagnosed in the women with the clinical diagnosis of postmenopausal osteoporosis and at least 1 fragility fracture. The control group included women without osteoporosis. Polymorphic sites in osteoporosis predisposition genes (ApaI, BsmI, TaqI, and Cdx2 of the VDR gene, G2046T of the COL1A1 gene, and T-13910C of the LCT gene) were determined using the polymerase chain reaction on the deoxyribonucleic acid isolated from dried bloodspots.
Results. The data showed that the ApaI and BsmI polymorphisms of the VDR gene and T- 13910C of the LCT gene were associated with severe postmenopausal osteoporosis in the analyzed Belarusian women (P<0.01). A statistically significant positive correlation between the VDR risk genotypes ApaI and TaqI and bone mineral density was found (P<0.05).
Conclusions. The findings of this study suggest that at least the ApaI and BsmI polymorphisms of the VDR gene and T-13910C of the LCT gene are associated with the risk of postmenopausal osteoporosis in our sample of the Belarusian women. Full article

The aim of the article was to overview the pathophysiology of the conventional outflow pathway, trabecular meshwork, and intraocular pressure and to discuss the options of future glaucoma treatment directed to improvement in aqueous outflow. The literature search in the Medline, Embase, and Cochrane databases from April to May 2012 was performed; a total of 47 articles analyzed. The diminished conventional pathway may be altered by several pathophysiological mechanisms like TM obstruction caused by transforming growth factor-β2, clastic nondeformable cells, macrophages leaking from hypermature cataract, iris pigment, lens capsular fragments after YAG-laser posterior capsulotomy, proteins and their subfragments. It is known that trabecular meshwork contraction reduces outflow, and the actomyosin system is directly linked to this mechanism. New glaucoma drugs are still under investigation, but it is already proven that agents such as latranculin-B are effective in improving aqueous drainage. Selective Rho-associated coiled coilforming protein kinase inhibitors have been shown to cause a significant improvement in outflow facility and may become a new option for glaucoma treatment. Caldesmon negatively regulates actin-myosin interactions and thus increases outflow. Stem cells may replace missing or nonfunctional trabecular meshwork cells and hopefully will bring a new treatment solution. Pathophysiological mechanisms regulating conventional aqueous humor outflow are still not fully understood and require further investigations. Future treatment decisions should be directed to a specific mechanism regulating an elevation in intraocular pressure. Full article

Atomic force microscopy is a valuable and useful tool for the imaging and investigation of living cells in their natural environment at high resolution. Procedures applied to living cell preparation before measurements should be adapted individually for different kinds of cells and for the desired measurement technique. Different ways of cell immobilization, such as chemical fixation on the surface, entrapment in the pores of a membrane, or growing them directly on glass cover slips or on plastic substrates, result in the distortion or appearance of artifacts in atomic force microscopy images. Cell fixation allows the multiple use of samples and storage for a prolonged period; it also increases the resolution of imaging. Different atomic force microscopy modes are used for the imaging and analysis of living cells. The contact mode is the best for cell imaging because of high resolution, but it is usually based on the following: (i) image formation at low interaction force, (ii) low scanning speed, and (iii) usage of “soft,” low resolution cantilevers. The tapping mode allows a cell to behave like a very solid material, and destructive shear forces are minimized, but imaging in liquid is difficult. The force spectroscopy mode is used for measuring the mechanical properties of cells; however, obtained results strongly depend on the cell fixation method. In this paper, the application of 3 atomic force microscopy modes including (i) contact, (ii) tapping, and (iii) force spectroscopy for the investigation of cells is described. The possibilities of cell preparation for the measurements, imaging, and determination of mechanical properties of cells are provided. The applicability of atomic force microscopy to diagnostics and other biomedical purposes is discussed. Full article

Background and Objective. In this study, we attempted to determine whether the C/T polymorphism of the ET-1 gene was significantly associated with changes in several clinical characteristics after the 16-week combined exercise program in overweight middle-aged women.
Material and Methods. The C/T polymorphism of the ET-1 gene was assayed using polymerase chain reaction, i.e., the TaqI restriction fragment length polymorphism method.
Results. The genetic variation in the ET-1 gene showed a significant association with the serum LDL cholesterol level as well as several parameters of physical fitness, including muscular endurance and power of the participants (P<0.05). In addition, this genetic variation showed a significant association with changes in muscular strength of the participants after the 16-week combined exercise program (P<0.05).
Conclusions. Our data suggest that the C/T substitution on intron 4 of the ET-1 gene may be a useful genetic marker influencing muscular strength through a gene-exercise interaction and is associated with an interindividual difference of cardiovascular risk factors and parameters of physical fitness. Full article

We report the case of the osteochondroma of the fibular head in a 40-year-old female patient who underwent an endoscopic extirpation of a relapsed benign tumor. Initially, open surgery was performed, and the tumor was removed 3 years ago. Following the reoccurrence of the symptoms 3 years after the initial open extirpation, an x-ray and computed tomography of the calf were performed. The tumor was endoscopically removed, and the diagnosis of a relapsed osteochondroma measuring 1.5×1.5×2 cm was established. Endoscopic surgery can be applied for a successful extirpation of the osteochondroma of the fibular head. Full article