Selenium status in soils in Yugoslavia

In the last 8 years, a number of data on selenium (Se) content and distribution in the soil of Yugoslavia (Serbia and Montenegro) became available. The Se content of the soil in Yugoslavia varies in a broad range 39 to 440 microg/kg (mean value 230 microg/kg; n = 284). The soil clay fraction is rich in Se (range 146 to 586 microg/kg) in relation to sand and silt fractions. The available Se content (after extraction with ammonium acetate and EDTA) varies in the range of 1.2 to 28.2% of the total Se content. The speciation of Se is shown for the soils derived from volcanic rocks in Serbia. In addition, the influence of some soil properties on the Se content, as well as its content in the rocks, sediment, and wild plants in Yugoslavia, is discussed. The geographical distribution of Se in the soil of Yugoslavia shows that it is found in inadequate amounts in many agricultural regions. Its low content in soil has been thought to be associated with a higher incidence of some diseases. The Se content of the soil in Yugoslavia is not fully known. There is a great need to make a systematic geochemical mapping for Se and other trace elements in the soil.     

Dirofilariasis in France: a case in Languedoc in an HIV-seropositive patient

Dirofilaria repens is an endemic canine parasite in the Mediterranean area. Human infestation is rare. We observed a case in an HIV-positive patient who presented an ocular filaria which was successfully removed under local anesthesia. In man, filariae may be expulsed without a parasite cycle or complete a growth cycle, depending on the individual's immunological status. The disease has been known in southern France for several centuries, mainly in lagoons near the Mediterranean seaside. A review of the literature however shows that observation of clinical cases is rare, only 46 cases having been reported to date. Outcome is favorable.     

Melanoma in pregnancy

The incidence of pregnancy complicated by melanoma of the skin, calculated from data of the Netherlands Cancer Registry, is 1 per 10,000 pregnancies. The prognosis of a melanoma is not affected by prior or subsequent pregnancy. A melanoma diagnosed during pregnancy does appear to have a more unfavourable prognosis, due not to a less favourable clinical course, but to a delay in diagnosing melanoma during pregnancy and (or) a less favourable site. When a pregnancy is complicated by malignancy, in case of a melanoma there is a higher risk of placental metastasis compared with other malignancies. In nearly 50% of the cases reported in literature of placental metastasis there was foetal involvement.     

Fluctuations in composition in dilute alloys under irradiation

Solute segregation in alloys and steels during irradiation has been studied both experimentally and theoretically for a number of years. In this paper, a rigorous theory for the segregation of solute in a dilute binary alloy is described which is based on the kinetic theory of diffusion. This theory is then used to predict irradiation-induced instabilities in the diffusion of the solute which cause spatial oscillations in composition. It is shown that trapping of both vacancies and interstitials at solute atoms can cause such instabilities. The results of numerical calculations are compared with experimental results. This paper is based on a presentation made in the symposium “Irradiation-Enhanced Materials Science and Engineering” presented as part of the ASM INTERNATIONAL 75th Anniversary celebration at the 1988 World Materials Congress in Chicago, IL, September 25-29, 1988, under the auspices of the Nuclear Materials Committee of TMS-AIME and ASM-MSD.     

深度学习中注意力机制研究进展

对注意力机制的主流模型进行了全面系统的概述。注意力机制模拟人类视觉选择性的机制,其核心的目的是从冗杂的信息中选择出对当前任务目标关联性更大、更关键的信息而过滤噪声,也就是高效率信息选择和关注机制。首先简要介绍和定义了注意力机制的原型,接着按照多个层面对各种注意力机制结构进行分类,然后对注意力机制的可解释性进行了阐述同时总结了在各种领域的应用,最后指出了注意力机制未来的发展方向以及会面临的挑战。      

Needle arthroscopy in rheumatology--its role in diagnosis and therapy

Needle arthroscopy is a new technique in rheumatology. The procedure is only marginally more invasive than a normal joint puncture, because small instruments are available. The method allows repeated interventions, e.g. synovial biopsy under visual inspection during the course of a disease. The procedure is demonstrated in detail, and the possibilities in the management of rheumatic diseases offered by needle arthroscopy are discussed.     

Fibrillations in regenerating muscle in dystrophic myopathies

In the presented study we attempted to demonstrate a correlation between muscle regeneration and fibrillations in electromyography in dystrophic myopathies. Especially in Emery-Dreifuss muscular dystrophy there is much abnormal spontaneous activity, and NCAM (neural cell adhesion molecule)and cytoskeletal protein vimentin expressing myocytes are predominantly seen. Therefore, definitely regenerating fibers are identified apart from only a few remnants of previous necrosis. Moreover, in the other biopsies of dystrophic myopathies there are also scattered and clustered NCAM and vimentin expressing regenerating myofibers. Here, regressive fiber changes, like necrosis, are more prominent. Furthermore, most regenerating fibers show pseudo-cholinesterase activity indicating innervation. Interestingly, motor end-plate changes in regeneration and in disuse atrophy are very similar. They predominantly consist of terminal sprouting and pseudo-cholinesterase spread. However, in disuse atrophy there is no abnormal spontaneous spread in electromyography. Therefore, in regenerating muscle not innervation, but regeneration itself is likely to be the cause of fibrillations. In conclusion, a correlation is evident between regenerating muscle and fibrillations in electromyography.     

Cytokines in implantation

Implantation is a complex process which involves the 'invasion' of the maternal endometrium by the trophoblast surrounding the developing blastocyst. In response to this interaction there is a cellular reaction within the endometrium which has some features analogous to invasion by a tumour and some which are more characteristic of an inflammatory response. In addition, and also in common with cancer and inflammation, there is a release of biologically active molecules, including cytokines, at and around the implantation site. The information on cytokines is complex and often contradictory but it is recognised that they play an important role in the successful establishment of pregnancy. The evidence for this role is examined in this review.     

Geographic differences in seasonality of preterm births in Japan

Based on vital statistics from 1979 to 1983, we used a time-series analysis using the Box-Jenkins model (ARIMA model) to compare the seasonality of preterm births among 47 prefectures in Japan. We also evaluated the relation between seasonality of preterm births and temperature. According to the Box-Jenkins analysis, a seasonal moving average was detected for 44 prefectures. The seasonality of preterm births in general shows a bimodal pattern with two peaks, one in summer and one in winter. The most interesting result is that the peaks show a trend with geographic location; one peak is dominant in winter among the northern prefectures and the other peak is dominant in summer among the southern prefectures. Another important result is that the winter increase in preterm births is negatively correlated with mean winter temperature (R = -0.424, p = 0.003); on the contrary, the summer increase in preterm births is positively correlated with the average summer temperature (R = 0.549, p < 0.001). These results suggest that climate-associated factors should be associated with the occurrence of preterm births in Japan.     

Genetic mutations resulting in estrogen insufficiency in the male

Surgical wound suture is often considered of minor importance compared to the whole surgical operation. The aesthetical result of a wound suture is still hardly considered in general surgical practice compared to other "traditional" wound sutures. The Authors carried a prospective study an 201 intradermal absorbable sutures in clean general surgery. The results clearly show that with a limited increase of the mean operation time of 90 seconds, for a 10 cm suture, there are such positive clinical, and aesthetical results that it is advisable to use routinely this type of suture in elective clean surgery.     

IV ventricle astrocytomas in childhood: clinicopathological features in 21 cases

Retinoic acid is thought to induce transdifferentiation of multipotent epithelial stem cells in the developing buds of the ascidian Polyandrocarpa misakiensis. We isolated a cDNA clone from this species, named PmRAR, encoding a retinoic acid receptor (RAR) homologue. PmRAR clusters with other RARs on phylogenetic trees constructed by three different methods. Within the cluster, PmRAR is on a separate branch from all the subtypes of RARs, suggesting that RAR subtypes arose in the ancestral vertebrates after divergence of vertebrates and urochordates. The embryos of another ascidian species Ciona intestinalis were co-electroporated with a mixture of a PmRAR expression vector and a lacZ reporter plasmid containing vertebrate-type retinoic acid response elements. The expression of lacZ depended on the presence of both retinoic acid and PmRAR, suggesting that PmRAR is a functional receptor. PmRAR mRNA is expressed in the epidermis and mesenchyme cells of the Polyandrocarpa developing bud. The mRNA is not detectable in the mesenchyme cells in the adult body wall, but its expression can be induced by retinoic acid in vitro. These results suggest that the PmRAR is a mediator of retinoic acid signalling in transdifferentiation during asexual reproduction of protochordates.     

The change in laser usage in gastroenterology--the status in 1997

Since the establishing of laser technology in gastroenterology there has been a change in the indications for laser therapy and numerous new laser systems have been introduced in basic and clinical research. First the argon laser and later on the Nd:YAG laser were used mainly for bleeding peptic lesions, today emphasis is on palliative desobliteration of advanced esophageal and rectosigmoidal carcinoma. Moreover, in selected cases it is used for curative ablation of early carcinoma and dysplasia. A new field of application is photocoagulation of the "watermelon stomach". Despite of promising ablation results the erbium:YAG and holmium:YAG laser became not yet established in gastroenterology. Also the KTP laser is rarely used e.g. for treatment of telangiectasia. Difficult bile duct stones can be highly effective fragmented intracorporally by means of laser lithotripsy; an automatic stone-tissue discrimination system avoids uncontrolled injury of the bile ducts. The hitherto experimental interstitial laser therapy of primary and secondary liver malignancies shows excellent results, but online monitoring of the expansion of the necrosis is still a problem. Thermal probes, MRT technology and duplex sonography are under current evaluation. Photodynamic therapy (PDT) is now, after numerous pilot studies, investigated with larger numbers of patients. First results show a marked effectiveness in ablation of dysplasia and mucosal carcinoma. The photosensitizer 5-aminolaevulinic acid seems to be particularly effective for ablation of Barrett's mucosa and m-THPC for treatment of local carcinoma. Palliative PDT of bile duct cancer may help to avoid repeated endoprosthetic treatment. The possibilities and limitations of light induced fluorescence diagnostics of severe dysplasia and carcinoma in situ is now being evaluated intensively. This method might in future facilitate the endoscopic diagnosis of dysplasia in Barrett's esophagus and chronic inflammatory bowel disease.     

Inflammatory pseudotumor--differential diagnosis in lung tumor in a child

A case of a twelve-year-old girl with a big solid tumour in the right lung is presented. As malignancy could not be excluded, she was operated. A lobectomy was performed. Frozen section showed no malignancy. Histology showed inflammatory pseudotumour, which is a rare but important benign lung tumour in childhood. The recommended treatment is conservative resection.     

Antagonists in anesthesia

In modern anaesthesia various antagonists are used. They provide efficient tools to facilitate better control of pharmacological effects and side effects of drugs routinely used in anaesthesia. Naloxone is a competitive antagonist of opioids without any intrinsic activity. It counteracts respiratory depression, pruritus, sedation and analgesia caused by opioids. It is fast-acting with a duration of action of 45 to 90 min. Several investigators have reported severe side effects of naloxone including hypertension, tachyarrhythmias, left heart failure and cardiac arrest, and hence the use of naloxone must be carefully considered in every single patient. Flumazenil is a competitive antagonist of benzodiazepines. It is a remarkably safe drug and very effective to terminate all benzodiazepine effects in anaesthesia and intensive-care patients. Serious complications caused by flumazenil have been reported in patients receiving benzodiazepines in the treatment of seizure disorders and in patients with mixed intoxications. Neostigmine is one of several antagonists of neuromuscular blocking agents. Its side effects include bradycardia, increased bronchial secretions and increased peristalsis. Indication depends on the results of neuromuscular monitoring. Physostigmine is an unspecific antagonist of the central anticholinergic syndrome, an acute psychosis that may be caused by numerous drugs used in anaesthesia. Generally, antagonists should be carefully titrated. In emergency medicine the use of these antagonists is not recommended; the primary goal is to restore vital functions.     

Unsolved problems in comparing brain sizes in Homo sapiens

When brain size is compared across taxonomic levels, there is a clear relation between body parameters and brain size. It is generally stated that the correlation between brain size and body parameters becomes very small at the species level (Aboitiz, 1996), but this is not the case for Homo sapiens where there is a strong correlation between brain size and body size across racial groups that differ in body size. The control for body size across racial groups (and sexes) is rendered difficult because bodies do not just differ only in height and weight. Within groups different studies show weak and inconsistent brain size/body height correlations. A better understanding of brain size/body height relations must await better quality data and a better understanding of how exactly body parameters should be scaled between groups and sexes. We attribute the clear between-group and weak within-group correlations to the large variety of body sizes and body types in our species, a variety which is only equalled in selectively bred species of animals. At present, there is no meaningful basis for the comparison of brain sizes within and between racial groups and sexes.     

Adenosine triphosphate (ATP) levels in paracetamol-induced cell injury in the rat in vivo and in vitro

We have investigated the relationship between ATP levels and the onset and progression of cell injury induced by paracetamol overdose both in vivo and in vitro. Liver slices obtained from phenobarbitone-induced and non-induced rats were used in a model in vitro system. Slices were exposed to paracetamol (2-10 mM), for 120 min and then incubated without paracetamol for a further 240 min. ATP levels are reduced upon exposure to paracetamol in liver slices from both phenobarbitone-induced and non-induced rats. Cell injury, as quantified by measuring leakage of lactate dehydrogenase (LDH) and potassium (K+), does not become apparent until 240 min, some 120 min after exposure to paracetamol had ended. This irreversible cell injury is not observed in liver slices from non-induced rats. For in vivo studies rats were phenobarbitone-induced and received i.p. injections of 800 mg/kg body weight paracetamol. Hepatic ATP levels were measured and are found to drop sharply by 3 h post-injection. Development of irreversible hepatic cell injury was assessed by measuring serum enzyme (ALT) activity. ALT levels do not rise until 12 h have elapsed. Paracetamol in overdose gives rise to ATP depletion in liver cells, that is early, independent of paracetamol metabolism and probably spread throughout the lobule. In contrast cell injury is found late and only in our phenobarbitone-induced rats. No cell injury is observed in liver slices from non-induced rats. This suggests that while the level of ATP depletion which is observed may be a necessary part of cell injury by paracetamol, it is not a sufficient cause.