Use of the fluid-filled tecna device in Ljubljana,Yugoslavia

Efforts to develop intrauterine devices that conform well to the shape of the uterine cavity have met with mixed success. The fluid-filled Tecna device was designed on the assumption that the pain and bleeding experienced with large IUDs resulted from the mechanical action of the device on the endometrium. The fluid transmits pressure from the contracting uterus in order to avoid localized areas of endometrial compression. Results from a study of 290 cases suggest that the performance of this device is suboptimal relative to the three events pertinent to the design of any intrauterine device—pregnancy, expulsion and bleeding/pain removals. The one-year rates per 100 women for these three events were 4.6, 23.1, and 8.0, respectively. These rates are higher than previously reported rates for the M-device, the Loop D and Dalkon Shield in this clinic. Bleeding associated with the use of this device was heavy and persistent. In addition the physician encountered difficulties in inserting the device. Results from this study indicate that changes in the design will be necessary to improve performance and acceptability of this device.     

Diazenecarboxamide UP-91, a potential anticancer agent,acts by reducing cellular glutathione content

Glutathione (GSH) is a ubiquitous non-protein thiol essential for cellular homeostasis and protection. Diazenecarboxamides (diazenes) are new compounds that could, according to their biochemical properties, lower the intracellular GSH content, thus inhibiting the growth of tumour cells. In the present study we examined four such compounds: JK-914, JK-918, JK-1013 and UP-91. Their cytotoxic effect on the growth of eight human tumour cell lines (glioblastoma, cervical and laryngeal carcinoma cells, mammary carcinoma cells and four drug-resistant sublines) was determined using a modified colorimetric MTT assay. The rate of reaction of thiophenol (as a model thiol) with diazenes leading to diphenyl disulfide was established by chromatography (TLC). Reactivity of diazenes with GSH under quasi-physiological conditions was determined by NMR spectroscopy. Intracellular GSH content was examined spectrophotometrically by the procedure developed by Tietze (1969). Diazene UP-91 reduced significantly the cell survival of all eight examined cell lines, including four drug-resistant cell lines. Other diazenes did not influence the survival of tumour cells. Reaction time for quantitative conversion of thiophenol to diphenyl disulfide was shortest for diazene UP-91, which is highly consistent with high reactivity of the same diazene with GSH, observed under quasi-physiological conditions. UP-91 reduced intracellular GSH level, while other diazenes had no effect on it. Thus, diazenecarboxamides UP-91 is a potential anticancer agent that may inhibit the growth of tumour cells due to reduction in glutathione level.     

Expression of vasoactive intestinal polypeptide and calcitonin gene-related peptide in human stellate ganglia after acute myocardial infarction

Using the method of indirect immunofluorescence the distribution of vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP) was investigated in autopsy specimens of human stellate ganglia following acute myocardial infarction (AMI). The dramatic increase of both VIP- and CGRP-immunoreactivities in principal ganglionic neurons as well as of calcitonin gene-related peptide in perineuronal nets was revealed. It was concluded that hypoxia and myocardial ischaemia following AMI are the main inducing factors for activation of both vasoactive regulatory neuropeptide synthesis. The upregulation of VIP and CGRP expression in sympathetic ganglionic neurons may provide regulatory and trophic support to the ischaemic heart.     

Retinal mean transit time in patients with primary open-angle glaucoma and normal-tension glaucoma

PURPOSE: To compare the mean transit time (MTT) of retinal circulation in eyes with primary open-angle glaucoma (POAG) and eyes with normal-tension glaucoma (NTG) and examine the possible relationship between MTT and visual field damage, expressed as mean deviation (MD). METHODS: Video fluorescein angiography was performed in 40 patients with POAG or NTG. Dye curves for fluorescein passing through the retinal arteries and veins were used to calculate MTT in each patient with a computer-assisted technique based on an impulse-response analysis (MTT(IR)). RESULTS: We were able to analyse MTT(IR) in all 40 angiograms. Mean (SD) MTT(IR) was 5.0 (1.5) seconds in eyes with POAG and 4.7 (1.4) seconds in eyes with NTG. The difference was not statistically significant. There was a weak but significant correlation between the MD and MTT(IR) (MTT(IR) = 4.12-0.08*MD; r = -0.49, p = 0.0013). CONCLUSIONS: The results demonstrate that loss of neuronal tissue in glaucoma is combined with an effect on the retinal circulation and that the effect is similar in eyes with NTG and eyes with POAG.     

Biomechanical trial of modified flexor tendon sutures: An in vitro study

Abstract Proven benefits of early active mobilisation for intra-synovial flexor tendon repairs have inducted new criteria for a 'perfect suture'. This study has examined different variations of modified Kessler's suture, which could fulfil the new criteria. A total of 93 swine extensor tendons were transected, repaired and tested using a dynamometer with constant rate of extension. The first part of study tested clinically the most used modified Kessler suture, a variation of double modified Kessler suture and intact tendons as a control group. Further variations in the second part of study were due to type of suture, location and number of the knots and type of peripheral suture. According to the results, the tested version of double modified Kessler suture with crossed peripheral suture was the strongest one among all tested variations. The ultimate force for the authors preferred modification of the double modified Kessler (DMK) is significantly higher than modified Kessler suture. The version of DMK with crossed peripheral suture is the strongest one among all tested variations. The lowest strength manifests variation with two knots between tendon ends. The variations with interlocked and outsided knot or monofilament tread are not statistically significant regarding ultimate force. The frequency of suture failure events (suture pull out or tendon and/or suture rupture) is equal respecting braided or monofilament suture. The preferred modification of the double modified Kessler (DMK) suture with crossed peripheral suture is the strongest one among all tested variations and could achieve, concerning range of force, early active mobilisation. Further variations due to the type of thread and location, type and number of the knots did not show statistical significance.     

Sagittal suture morphological variation in human archaeological populations

Cranial sutures join the many bones of the skull. They are therefore points of weakness and consequently subjected to the many mechanical stresses affecting the cranium. However, the way in which this impacts their morphological complexity remains unclear. We examine the intrinsic and extrinsic mechanisms of human sagittal sutures by quantifying the morphology from 107 individuals from archaeological populations spanning the Mesolithic to Middle ages, using standardized two-dimensional photographs. Results show that the most important factor determining sutural complexity appears to be the position along the cranial vault from the junction with the coronal suture at its anterior-most point to the junction with the lambdoid suture at its posterior-most point. Conversely, factors such as age and lifeways show few trends in complexity, the most significant of which is a lower complexity in the sutures of Mesolithic individuals who consumed a tougher diet. The simple technique used in this study therefore allowed us to identify that, taken together, structural aspects play a more important role in defining the complexity of the human sagittal suture than extrinsic factors such as the mechanical forces imposed on the cranium by individuals' diet.     

Assessment of Endothelial Dysfunction: The Role of Symmetrical Dimethylarginine and Proinflammatory Markers in Chronic Kidney Disease and Renal Transplant Recipients

Objectives. The study was designed to evaluate associations between symmetric dimethylarginine (SDMA), inflammation, and superoxide anion (O₂^∙−) with endothelial function and to determine their potential for screening of endothelial dysfunction in patients with chronic kidney disease (CKD) and renal transplant (RT) recipients. Materials and Methods. We included 64 CKD and 52 RT patients. Patients were stratified according to brachial artery flow-mediated dilation (FMD). Results. Logistic regression analysis showed that high SDMA and high sensitive C-reactive protein (hs-CRP) were associated with impaired FMD in CKD and RT patients, after adjustment for glomerular filtration rate. The ability of inflammation, SDMA, and O₂^∙− to detect impaired FMD was investigated by receiving operative characteristic analysis. Hs-CRP (area under the curves (AUC) = 0.754, P < 0.001), IL-6 (AUC = 0.699, P = 0.002), and SDMA (AUC = 0.689, P = 0.007) had the highest ability to detect impaired FMD. SDMA in combination with inflammatory parameters and/or O₂^∙− had better screening performance than SDMA alone. Conclusions. Our results indicate a strong predictable association between hs-CRP, SDMA, and endothelial dysfunction in CKD patients and RT recipients. The individual marker that showed the strongest discriminative ability for endothelial dysfunction is hs-CRP, but its usefulness as a discriminatory marker for efficient diagnosis of endothelial dysfunction should be examined in prospective studies.     

Applicability of electro-osmotic flow for the analysis of the surface zeta potential

The analysis of the surface zeta potential (SZP) opens up new possibilities in the characterization of various materials used for scientific or industrial applications. It provides at the same time insight into the material surface chemistry and elucidates the interactions with charged species in the aqueous test solution. For this purpose, an accurate, reliable and repeatable analysis of the SZP is the key factor. This work focuses on a detailed and systematic comparison of two electrokinetic techniques, i.e. the mapping of the electro-osmotic flow (EOF) and the measurement of the streaming potential (SP), for the surface zeta potential (SZP) determination of several materials with varying properties. Both techniques have advantages as well as drawbacks. The applicability of latex polymer material and inorganic tracer particles at varying ionic strength, the interaction between oppositely charged tracer particles and solid surfaces, the assessment of the pH dependence of the SZP and the isoelectric point (IEP), and the effects of sample porosity and conductance have been investigated. Although in some cases the EOF method gives a SZP similar to the streaming potential measurement, especially when the tracer particle exhibits the same charge as the solid surface, it was revealed that reliable results were only obtained with the streaming potential and streaming current method. Several obstacles such as elevated conductivity at higher ionic strength, the applied voltage for the EM measurement, and the nature of tracer particles lower the accuracy and reliability of the SZP determined by the EOF method. It was shown that the EOF method is not applicable to oppositely charged surface and tracer particles and also limited to low salinity conditions especially when using polymeric tracer particles. Although the EOF method does not require the formation of a capillary flow channel, it disables a non-destructive SZP of fragile or valuable samples, such as QCM-D sensors, in comparison to the SP approach.

Detail comparison of two different electrokinetic phenomena EOF and SP method for the SZP determination with taking into account various materials with different surface and bulk properties.