Myosin-X recruits lamellipodin to filopodia tips

Myosin-X (MYO10), a molecular motor localizing to filopodia, is thought to transport various cargo to filopodia tips, modulating filopodia function. However, only a few MYO10 cargoes have been described. Here, using GFP-Trap and BioID approaches combined with mass spectrometry, we identified lamellipodin (RAPH1) as a novel MYO10 cargo. We report that the FERM domain of MYO10 is required for RAPH1 localization and accumulation at filopodia tips. Previous studies have mapped the RAPH1 interaction domain for adhesome components to its talin-binding and Ras-association domains. Surprisingly, we find that the RAPH1 MYO10-binding site is not within these domains. Instead, it comprises a conserved helix located just after the RAPH1 pleckstrin homology domain with previously unknown functions. Functionally, RAPH1 supports MYO10 filopodia formation and stability but is not required to activate integrins at filopodia tips. Taken together, our data indicate a feed-forward mechanism whereby MYO10 filopodia are positively regulated by MYO10-mediated transport of RAPH1 to the filopodium tip.

Theoretical study of nitrodibenzofurans: A possible relationship between molecular properties and mutagenic activity

In this study we present a theoretical investigation of the molecular properties of nitrodibenzofurans (NDFs) and dinitrodibenzofurans (DNDFs) and their relation to mutagenic activity. Equilibrium geometries, relative energies, vertical ionization potentials (IP), vertical electron activities (EA), electronic dipole polarizabilities, and dipole moments of all NDFs and three DNDFs calculated by Density Functional Theory (DFT) methods are reported. The Ziegler/Rauk Energy Decomposition Analysis (EDA) is employed for a direct estimate of the variations of the orbital interaction and steric repulsion terms corresponding to the nitro group and the oxygen of the central ring of NDFs. The results indicate differences among NDF isomers for the cleavage of the related bonds and steric effects in the active site. The results show a good linear relationship between polarizability (<α>), anisotropy of polarizability (Δα), the summation of IR intensities (ΣIIR) and the summation of Raman activities (ΣARaman) over all 3N-6 vibrational modes and experimental mutagenic activities of NDF isomers in Salmonella typhimurium TA98 strain. The polarizability changes with respect to the νsNO+CN vibrational mode are in correlation with the mutagenic activities of NDFs and suggest that intermolecular interactions are favoured along this coordinate.

Molecular and morphological variability within the Aphidius colemani group with redescription of Aphidius platensis Brethes (Hymenoptera: Braconidae: Aphidiinae)

We have identified the following three taxa related to the Aphidius colemani species group, which are important biological control agents: Aphidius colemani, Aphidius transcaspicus and Aphidius platensis. Using partial sequences of the mitochondrial cytochrome oxidase subunit I (mtCOI) gene and geometric morphometric analysis of the forewing shape, we have explored the genetic structure and morphological variability of the A. colemani group from different aphid host/plant associations covering a wide distribution area. The topology of the maximum parsimony and maximum likelihood trees were identical with 98-100% bootstrap support, clustering A. colemani, A. platensis and A. transcaspicus into separate species. The distances among the taxa ranged from 2.2 to 4.7%, which is a common rate for the between-species divergence within the subfamily Aphidiinae. Differences in the shape of the forewing investigated within the biotypes of A. colemani group are congruent with their genetic diversification. Both A. platensis and A. colemani share a common host range pattern, and it would be interesting to estimate and compare the role of these two species in future biological control strategies against aphids of economic importance. Our results indicate that 'genetic screening' is a reliable approach for identification within the A. colemani group. The high variation in the wing shape among species, including a significant divergence in the wing shape among specimens that emerged from different hosts, makes the forewing shape and wing venation less reliable for species determination. Aphidius platensis is diagnostified and redescribed, and the key for the A. colemani group is presented.

Monitoring of trace element atmospheric deposition using dry and wet moss bags: accumulation capacity versus exposure time

To clarify the peculiarities of trace element accumulation in moss bags technique (active biomonitoring), samples of the moss Sphagnum girgensohnii Rusow were exposed in bags with and without irrigation for 15 days up to 5 months consequently in the semi-urban area of Belgrade (Serbia) starting from July 2007. The accumulation capacity for 49 elements determined by ICP-MS in wet and dry moss bags was compared. The concentration of some elements, i.e. Al, V, Cr, Fe, Zn, As, Se, Sr, Pb, and Sm increased continuously with exposure time in both dry and wet moss bags, whereas concentration of Na, Cl, K, Mn, Rb, Cs, and Ta decreased. Irrigation of moss resulted in a higher accumulation capacity for most of the elements, especially for Cr, Zn, As, Se, Br, and Sr. Principal component analysis was performed on the datasets of element concentrations in wet and dry moss bags for source identification. Results of the factor analysis were similar but not identical in the two cases due to possible differences in element accumulation mechanisms.

Active moss biomonitoring of trace elements with Sphagnum girgensohnii moss bags in relation to atmospheric bulk deposition in Belgrade, Serbia

Active biomonitoring with wet and dry moss bags was used to examine trace element atmospheric deposition in the urban area of Belgrade. The element accumulation capability of Sphagnum girgensohnii Russow was tested in relation to atmospheric bulk deposition. Moss bags were mounted for five 3-month periods (July 2005-October 2006) at three representative urban sites. For the same period monthly bulk atmospheric deposition samples were collected. The concentrations of Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb were determined by instrumental neutron activation analyses and atomic absorption spectrometry. Significant accumulation of most elements occurred in the exposed moss bags compared with the initial moss content. High correlations between the elements in moss and bulk deposits were found for V, Cu, As, and Ni. The enrichment factors of the elements for both types of monitor followed the same pattern at the corresponding sites.

[Reversible dysfunction of the left ventricle in coronary disease (part two): hibernation and methods for detection of viability]

HIBERNATION: Hibernating myocardium is defined as a state of persistently impaired myocardial function, as a consequence of reduced coronary flow, which can be partially or completely reversed if the myocardial oxygen consumption/demand ratio is favorably altered. Since it indicates concordance between flow and function (flow-function relation), it can be concluded that hibernating myocardium, caused by reduced myocardial perfusion, improves its function after surgical revascularization, giving its detection a great clinical importance. Hibernating myocardium can be found in majority of patients with coronary artery disease and chronic left ventricular dysfunction. These patients, even without typical symptoms of angina, will benefit from myocardial revascularization. This beneficial effect is expressed by ejection fraction enhancement, which is directly proportional to the number of dysfunctional, but viable segments. Also, symptom improvement depends on the mass of revascularized myocardium, which is previously shown to be viable. Having that in mind, the mass of viable myocardium must be large enough, so that the degree of expected improvement of myocardial function after revascularization justifies the operation itself. Opposing this classical concept of hibernating myocardium, recent studies have shown that in patients with coronary artery disease, coronary flow at rest is normal or just slightly reduced, which cannot explain the degree of myocardial dysfunction. According to that, it is proposed that myocardial dysfunction is, like in myocardial stunning, the result of flow-function mismatch, meaning that pathophysiology of hibernating myocardium includes a component of stunning as well. Therefore, hibernating myocardium can be defined as a form of reversible left ventricular dysfunction, caused by chronic coronary artery disease, which is partially due to episodes of repetitive stunning and shows improvement after inotropic stimulation. From practical point of view, it is important to detect hibernating myocardium in all patients with coronary artery disease and left ventricular dysfunction, since their treatment and prognosis directly depend on whether the dysfunction is reversible or not. METHODS FOR IDENTIFICATION OF MYOCARDIAL VIABILITY: Detection of myocardial viability has great clinical importance, since both regional and global left ventricular function can significantly improve, either spontaneously or by myocardial revascularization. Noninvasive imaging procedures used for that purpose include positron emission tomography, thallium-201 imaging, technetium-99 imaging, dobutamine echocardiography and tissue characterization. Using these methods, it is possible to assess the presence of viable tissue through evaluation of metabolic activity, integrity of myocyte membrane and the inotropic reserve of myocardium.

[Reversible left ventricular dysfunction in coronary disease (part one): myocardial stunning]

INTRODUCTION

The concept of myocardial stunning has been proposed by Braunwald and Kloner in early 1980's and is defined as transient postischemic myocardial dysfunction that persists after reperfusion, despite the absence of irreversible damage and restoration of normal or near normal coronary flow. Thus, the hallmark of stunned myocardium is the mismatch between coronary flow and myocardial function.

MYOCARDIAL STUNNING

The two most plausible hypotheses used to explain the pathogenetic mechanisms of myocardial stunning are calcium and oxyradical hypotheses. According to the first one, myocardial stunning is the result of impaired calcium homeostasis caused either by calcium overload or decreased responsiveness of myofilaments to calcium. The oxyradical hypothesis postulates that generation of free oxygen radicals depresses myocardial function after the ischemic episode. The exact mechanism is unknown, but it is probably due to extreme reactivity of oxyradicals that bind to some cellular components, impairing membrane permeability and function of various cell organelle. Stunned myocardium can be seen in numerous clinical situations in which myocardial ischemia has been followed by reperfusion. These include: coronary artery bypass surgery, acute myocardial infarction, stable, unstable and variant angina, percutaneous transluminal coronary angioplasty and cardiac transplantation.

DISCUSSION AND CONCLUSION

In majority of these situations, stunned myocardium is usually well tolerated. However, there is a group of high-risk patients in whom prolonged myocardial dysfunction due to stunning can cause serious hemodynamic instability, which requires pharmacological and/or mechanical support. Therefore, in order to avoid these situations, some authors have suggested that stunned myocardium should be prevented, rather than treated. Since stunned myocardium is by definition reperfused, with normal or near normal coronary flow, treatment is reserved only for those patients in whom stunned region is large enough to cause low cardiac output and hypotension. Revascularisation is usually unnecessary; however, there are situations in which episodes of repetitive stunning cause chronic myocardial dysfunction along with hibernated myocardium, when myocardial revascularization would be beneficial.

Reversed-phase ion-pair HPLC determination of some water-soluble vitamins in pharmaceuticals

A reversed-phase ion-pair high-performance liquid chromatografic method (RP-IPC) was developed to assay some water-soluble vitamins in solution dosage forms. Vitamins of the B-group B1, B2, B3, and B6, including vitamin C were determined in Oligovit coated tablets. In Beviplex coated tablets the vitamins B1, B2, B3, B6 and p-aminobenzoic acid were analysed. Hexanesulphonic acid sodium salt and triethanolamine in water methanol were used as mobile phase with adjusting pH to 2.8 with orthophosphoric acid. Phenol was used as an internal standard. For quantitative simultaneous analysis of vitamins in pharmaceutical formulations, the method of internal standard was used. All parameters for the validation of the method are given.

Serial assessment of left ventricular chamber stiffness after acute myocardial infarction

Left ventricular (LV) systolic function after acute myocardial infarction (AMI) has been the subject of detailed studies during the last decade, but diastolic phenomena during and after AMI are less well understood. Recently, it has been shown that early filling deceleration time accurately predicted LV chamber stiffness in an experimental model. To assess changes of LV stiffness after AMI, we studied 116 consecutive patients with 2-dimensional and Doppler echocardiographic examinations 1, 2, 3, 7, 21, and 42 days after AMI. Coronary angiography was performed in 101 patients. For the entire study group, deceleration time decreased nonsignificantly on day 2 and subsequently increased on days 3 (p = 0.001) and 7 (p = 0.036), returning toward initial values afterward. Deceleration time was shorter in large (peak creatine kinase level >1,000 U/L) versus small infarcts (p = 0.0008) and in patients with anterior versus inferior AMI (p = 0.02); there was no difference between patients with good and poor (< or = 45%) ejection fraction. These data indicate that increased LV stiffness can be detected 24 to 48 hours after AMI, but returns to normal within several days. Chamber stiffness is higher in large and anterior infarcts, but appears to be independent of LV systolic function.

Altered gonadal hormone level and constant light-induced stress interfere with the response of the adrenal medulla to oxytocin

The effect of oxytocin (0.25 IU/100 g per day) on the adrenal medulla was examined in intact, intact estrogen-treated, castrated and castrated testosterone-treated adult male Wistar rats. Stereological analysis of the gland (N = 5 rats per group) revealed that in intact animals the number of chromaffin cells (x10(3)) was significantly increased after 3-day (saline: 467.6 +/- 27.4; oxytocin: 567.6 +/- 28.9) or 7-day (saline: 486.2 +/- 39.1; oxytocin: 618.7 +/- 36.8) oxytocin administration. During 7 days of recovery after the 7-day treatment, the chromaffin cell number returned to the control level (saline: 491.4 +/- 12.6; oxytocin: 554.4 +/- 28.7). The effect of oxytocin on chromaffin cell number was also observed in rats simultaneously injected with estradiol (0.3 micrograms/100 g per day) for 10 days (estradiol: 454.3 +/- 32.8; estradiol+oxytocin: 576.1 +/- 25.0), as well as in 10-day castrated rats (saline: 594.7 +/- 22.7; oxytocin: 765.3 +/- 33.1). Testosterone replacement (0.6 mg/100 g per day) abolished the medullary response to oxytocin (testosterone+saline: 528.5 +/- 24.7; testosterone+oxytocin: 620.8 +/- 56.0). There was a 20% rise in adrenal dopamine content (from 0.236 +/- 0.015 to 0.283 +/- 0.015 microgram per pair of glands; N = 9-12) in intact rats injected with oxytocin for 3 days. Oxytocin had no effect on any of the catecholamine levels in adrenal glands of rats exposed to stress induced by constant lighting. The present data indicate that the proliferative response of chromaffin tissue to oxytocin depends on the gonadal hormone level and the basal activity of the adrenal medulla.

Rat accessory sex glands response to oxytocin under different light regimens

Effects of oxytocin (0.25 IU OT/100 g/d for 3 days) on accessory sex glands structure and catecholamine content were examined in rats kept on two different light regimens. In 12 h light/12 h dark conditions ventral prostate responded to OT by a regression of the epithelial component and an increase in dopamine content. Coagulating gland structure was not affected, but noradrenaline content of the seminal vesicle+coagulating gland complex was enhanced. Constant lighting per se caused atrophic changes in the prostatic epithelium, evident by decreased total volume and by increased percentage of acini containing cuboidal epithelium. OT treatment considerably prevented the epithelial atrophy without affecting catecholamines level. In the seminal vesicle+coagulating gland complex it reduced the dopamine content. Since this light regimen elevated the plasma ACTH, the altered accessory sex gland response to OT seems to be due to the stress-induced changes in the neuro-endocrine factors conditioning their function. The effects of OT on accessory glands catecholamine content indicate interferences with their autonomic control.

Mitotic activity and cell deletion in ventral prostate epithelium of intact and castrated oxytocin-treated rats

Previous study has shown that oxytocin (OT) attenuated the postcastration regression of ventral prostate epithelium in rats. To decide if this effect is associated with stimulation of cell division or improvement of cell survival, metaphase index of secretory cells and frequency of apoptotic bodies in the epithelium, combined with stereological parameters, were determined in the present study. OT was injected subcutaneously in a dose of 0.25 IU/100 g/d during 5 postorchiectomal days and the same treatment was applied to intact rats. Only the prostate of castrated animals responded to OT. They had greater total volume of the epithelium, total number and metaphase index of secretory cells, but lower frequency of apoptotic bodies. These findings demonstrate the ability of OT to stimulate mitotic activity and to diminish mortality of secretory cells caused by orchiectomy.

[The effect of occupational noxae in the tobacco industry on pulmonary function in exposed workers]

A study was carried out to determine respiratory hazards to workers in tobacco manufacture. The investigations at the workplace included analysis of the work technology and measurements of chemical pollutants and dust concentrations in the work rooms. Ventilatory lung function tests were performed in 95 workers exposed to tobacco dust and in 129 control workers. Results of workplace analysis showed the presence of tobacco dust levels exceeding the maximum permissible concentrations. The values of some lung function tests for exposed workers non-smokers were significantly lower than for control workers non-smokers. They could be attributed to the effect of occupational noxae on the respiratory system.

[Effect of industrial noise on cardiac systolic cycle in exposed workers]

First the working conditions in the "Ratko Pavlović-Niteks" textile industry were studied and analysed. It was found that industrial noise was one of the dominant noci, grading from 81 to 105 dB (A). It belonged to the group of high-frequency continued noises. The highest noise was recorded in the section "Tkacnica" (101 +/- 3.9 dB). Then the carotide artery curve was recorded before and after work in 411 workers exposed to noise of different intensity. At the same time a control group of 153 workers was studied. They worked in a relatively calmer section (section of dress cutting and control of finished goods). In workers exposed to noise a significant decrease of Q-I sound, I-II sound, ICT, IPEP intervals and PEP/LVET was recorded. However, ILVET was insignificantly increased after the work in comparison with its level before work. These results suggested the existence of significant haemodymanic changes due to industrial noise. Values of these parameters were closely related to the general noise level at working place. The greatest changes were observed in workers working under the effect of the greatest noise (95-105 dB), and the smallest in those working in the smallest noisy areas (75-85 dB). Thus, the intensity of haemodynamic changes depended on the level of general noise atworking place. Therefore appropriate preventive measures should be applied in practice in order to reduce the level of general noise.

[Successfull extirpation of femoral pseudotumour in a patient with severe haemophilia A and an inhibitor to factor VIII]

The article deals with a successfull extirpation of femoral pseudotumour in a 53-year-old patient with severe haemophilia A (F VIII: C less than 1%) and an inhibitor to factor VIII. Such case is the first one reported in Yugoslavia. A combination of ultrasonography, computed axial tomography, angiography and Tc-99m labelled red blood cell scintigraphy was used for precise diagnosis of the pseudotumour. Preoperative preparation consisted of 50 units/kg of concentrate of F VIII (Hemate P) and 50 units/kg of activated prothrombine complex concentrate (FEIBA). A pseudotumour, 15 cm in diameter, was extirpated, as well as a few dauther cysts. F VIII concentrate was used for postoperative supportive therapy. On the 5-th postoperative day the patient prematurely rose from his bed and the "secondary bleeding" had to be treated with F VIII concentrate. The success of complex operations in haemophiliacs is possible only in big centres which can provide the best diagnostic procedures, trained surgeon teams, and modern and various supportive therapy.

[The effect of occupational exposure to respiratory noxae in the tobacco industry on the status of pulmonary ventilation]

The study from the working environment prevailing in two departments of tobacco factory (DIN) Nis together with the study of the employees (95) working in these departments were carried out. The workers were divided into two sub-groups: smokers (62) and non-smokers (33) and the results of the lung function tests were compared to normal values. The results found point out to the presence of the tobacco dust in these departments and the values exceeding MAC might have caused the obstructive changes of airways in the workers exposed.

[Characteristics of acute myocardial infarct in young people]

The coronary heart disease is one of the main causes of the mortality and morbidity at the present time. The frequency of this disease is in constant increase and limitation of the age of the patient is in decrease. A group of 25 patients with acute myocardial infarction and under 40 years ob age, was analyzed. It was evident that genetic factor was more frequent in young persons and that they presented several risk factors at the same time. The anginal typical or atypical pains were not taken into a serious consideration. The course of infarction was less serious and complications were rare in comparison to a group of old patients.

The response of rat adrenal zona fasciculata and zona reticularis to oxytocin treatment

The response of the adrenal zona fasciculata (ZF) and zona reticularis (ZR) to oxytocin (OT) was examined in male rats using a stereological method. The 10-day administration of 0.25 IU OT/100 g daily caused an enlargement of ZF due to cell hypertrophy associated with striking lipid accumulation. The volume of ZR was decreased, this change being the consequence of the reduced cell population. The possible site of OT action is discussed.

Stereologic analysis of ventral prostate of oxytocin-treated rats

Ventral prostate response to oxytocin (OT) was examined in intact and castrated adult rats. The treatment consisted of 10 daily subcutaneous injections of 0.25 IU OT per 100 g body weight, which for orchiectomized rats began immediately after surgery. OT induced prostatic response only in castrated animals. Stereologic analysis revealed changes in the epithelial component, its total volume and surface being increased. The acinar lumen as well as the glandular weight were also enhanced. A possibility that the ventral prostate is the target organ for OT is discussed.

[Echocardiographic diagnosis of angiosarcoma of the heart]

Cardiac angiosarcoma is the most common primary malignant tumour of the heart that is rarely diagnosed ante mortem. The authors present the case of a 73-year-old female with right atrial angiosarcoma that was followed-up echocardiographically for 20 months. Echocardiographic features suggestive of primary and metastatic malignant tumours of the right heart are discussed.

The response of rat adrenal medulla to oxytocin

Effects of oxytocin (OT) on the adrenal chromaffin tissue of male rats were examined by coupled morphometric and biochemical techniques. Synthetic OT was administered in doses of 0.14 and 0.25 IU/100 g/d during 7 or 10 consecutive days and the effects were followed 1, 24, 72 and 168 hours after the last injection. The function and structure of chromaffin cells were affected by the higher dose of OT only. They caused divergent responses on their amine contents. Adrenaline, noradrenaline and dopamine contents were increased, while serotonin content was decreased. These changes were different in duration and time of incidence. Stereological analysis showed an enhanced number of chromaffin cells and an increase in their total volume. The parallelism between the changes in chromaffin cell number and the catecholamine content strongly suggests a mitogenic effect of the applied OT.