Exposure of healthy subjects with emissions from a gas metal arc welding process: part 3--biological effect markers and lung function.

BACKGROUND: Metal active gas welding (MAG) is a widely-used welding technique resulting in high emissions of welding fume particles. This study investigated whether short-term exposure to these fume particles results in changes in lung function and early stages of inflammatory reactions. METHODS: Twelve healthy, young male subjects were exposed to MAG fumes for 6 h with three different exposure concentrations in a three-fold cross-over study design. Exposure was performed in the "Aachen Workplace Simulation Laboratory" under controlled conditions with constant fume concentration. Fume concentrations were 0, 1, and 2.5 mg m(-3) in randomized order. Before and after each exposure, spirometry, and impulse oscillometry were performed and breath condensate samples were collected in order to quantify inflammatory markers like Nitrate, Nitrite, Nitrotyrosine, Hydroxyprolin and Malondialdehyde. RESULTS: A significant dependency on the exposure concentration could not be established for any of the endpoint parameters. CONCLUSION: In healthy, young subjects neither changes in spirometry nor changes in inflammatory markers measured in exhaled breath condensate could be detected after short-term exposure.

Effects of ultraviolet radiation and temperature on the ultrastructure of zoospores of the brown macroalga Laminaria hyperborea.

The interactive effects of an 8 h exposure to UV radiation and altered temperatures on the ultrastructure and germination of zoospores of the sublittoral brown alga Laminaria hyperborea (Gunn.) Foslie were investigated for the first time. Spores were exposed to four temperatures (2, 7, 12 and 17 degrees C) and three light regimes (PAR, PAR + UV-A, PAR + UV-A+UV-B). Freshly-released spores of L. hyperborea lack a cell wall and contain a nucleus with fine granular nucleoplasm and a nucleolus, one chloroplast, several mitochondria, dictyosomes and an endoplasmatic reticulum. Further, several kinds of so-called adhesive vesicles, lipid globuli and physodes containing UV-absorbing phlorotannins are embedded in the cytoplasm. No eye-spot is present. Physodes were found but they were rare and small. After an 8 h exposure to UV-B, the nucleoplasm had a mottled structure, chloroplasts contained plastoglobuli, the structure of the mitochondria changed from crista- to sacculus-type and germination was strongly inhibited at all temperatures. UV-A only had an impact on the ultrastructure at the highest temperature tested. The strongest effects were found at 17 degrees C, where germination was reduced to 35%, 32% and 9% after exposure to PAR, PAR+UV-A and PAR + UV-A + UV-B, respectively. This study indicates that UV-B radiation has strong damaging effects on the physiology and ultrastructure of zoospores of L. hyperborea. The results are important for developing scenarios for the effect of enhanced UV radiation and increasing temperatures caused by global climate changes.

[Men and women--aspects of sexological counseling in the aging]. / Mann und Frau. Aspekte der sexualmedizinischen Beratung von älter werdenden Menschen.

In our times, sexuality has become an essential part of life for aging people. For the aging, psychosocial and biological changes, as well as increasing morbidity present challenges to a satisfying sexual life. Hence, the demand grows for health-care providers with basic sexological knowledge and counseling abilities. This article discusses relationships between frequent sexual difficulties and aging related organic processes. A therapeutic concept, the "Sexocorporal Approach", is introduced. This approach is based on a model of ongoing sexual development throughout the lifetime enabling adaptation to new life phases and limiting circumstances through sexual learning processes. Aside from pharmacological treatment, the encouragement of sexual learning presents an effective therapeutic approach for practitioners that can be easily learned and applied.

Subcellular localization and processing of the lytic transglycosylase of the conjugative plasmid R1.

Protein P19 encoded by the conjugative resistance plasmid R1, is essential for efficient conjugative DNA transfer and infection by the pilus-specific RNA phage R17. Based on sequence homologies P19 belongs to a family of lysozyme-like virulence factors which are found in type III and type IV secretion systems. In this report we describe the processing and subcellular localization of P19. Pulse-chase experiments were used to demonstrate the processing of P19 by the signal peptidase I of Escherichia coli. Translocation of P19 across the inner membrane was shown by gene 19-phoA fusions. Cell fractionation studies of P19 expressing cells showed the presence of P19 in the membrane compartment. P19 was solubilized with the detergent Sarkosyl indicating an inner membrane localization. Using sucrose density gradient centrifugation to separate inner and outer membranes, P19 was found in both membrane fractions. Taken together, our data suggest that mature P19 is a periplasmic protein which may be attached to the proposed membrane-spanning DNA transport complex.

Photosynthetic performance of Arctic macroalgae after transplantation from deep to shallow waters.

Transplantation experiments conducted in the Arctic Kongsfjord (Spitsbergen) in summer 1997 investigated the effects of various types of filtered natural radiation (solar, solar without UV-B, solar without UV-A/B) on photosynthesis of various macroalgae. Two brown algal species (Laminaria solidungula, Saccorhiza dermatodea) and four red algal species (Palmaria palmata, Phycodrys rubens, Phyllophora truncata, Ptilota plumosa) were collected from deeper waters, kept in UV-transparent plexiglass tubes wrapped with different spectral cut-off filter foils and positioned at fixed depths in shallow waters for 7-9 days. At regular intervals, chlorophyll fluorescence of photosystem II (optimum quantum yield, F v/F m) was determined, as an indicator of photosynthetic performance. The data demonstrate that shallow-water species such as P. palmata are much less affected by natural photosynthetically active radiation (PAR) and UV radiation near the surface than extremely sensitive deep-water species such as Phyc. rubens which exhibited strong decreases in photosynthetic performance, as well as photobleaching of part of the thallus. The other species showed intermediate response patterns. In most species investigated inhibition of photosynthesis was mainly caused by the UV-B wavelengths. Interpretation of the data clearly indicates species-specific tolerances of photosynthesis to ambient solar radiation which can be explained by broad physiological acclimation potentials and/or genetic adaptation to certain (low or high) irradiances. The species-specific photosynthetic performance under radiation stress is in good accordance with the vertical distribution of the macroalgae on the shore.

[Leiomyosarcoma of the spermatic cord. A case report with review of the literature]. / Leiomyosarkom des Samenstrangs. Ein Fallbericht mit Literaturübersicht.

The case of a 68-year-old man with leiomyosarcoma of the spermatic cord is reported. Radical orchiectomy with high ligature of the cord was performed. Pathological examination including immunohistochemistry demonstrated a leiomyosarcoma which seemed to arise from a spermatic cord vessel.

MPLW515L mutation in acute megakaryoblastic leukaemia.

The thrombopoietin receptor gene (MPL) is expressed in megakaryocytes and exhibits the gain of function point mutation W515K/L in approximately 5% of patients with primary myelofibrosis/idiopathic myelofibrosis (PMF) representing one subtype of the chronic myeloproliferative disorders (myeloproliferative neoplasm). A series of primary and secondary acute myeloid leukaemias (AML) with megakaryoblastic phenotype and myelofibrosis unrelated to PMF (n=12) was analysed for the MPL(W515K/L) mutation by pyrosequencing. In three cases (25%), MPL(W515L) was found and in two of these a combination with trisomy 21 or the Philadelphia chromosome occurred. None of the secondary AML cases evolving from pre-existing PMF showed MPL(W515K/L) (n=4). We conclude that MPL(W515L) occurs in a considerable proportion of acute megakaryoblastic leukaemias with myelofibrosis unrelated to PMF.

[Metastatic placental site trophoblastic tumor. Diagnosis after pneumothorax]. / Metastasierter "Placental-site-Trophoblasttumor". Diagnose anlässlich eines Spontanpneumothorax.

Placental site trophoblastic tumor (PSTT) is a rare, mostly benign tumor, which in 10-15% of cases shows a malignant behavior. The case of a 35 year old woman with pulmonary metastasis of a PSTT is reported. This finding was incidental in an atypical lung-resection due to pneumothorax. The literature on this rare tumor entity is reviewed especially in terms of differential diagnosis, biological behavior and association with a pneumothorax.

Wundt's views on sensations of innervation: a reevaluation.

It is sometimes stated that Wundt believed in the primacy of 'sensations of innervation' in the control of eye and limb position, to the exclusion of afferent feedback. Wundt's own statements on the subject are traced through the six editions of the Grundzüge: he believed that sensations of innervation were a contributory factor along with peripheral feedback; but in the fourth edition he dropped the term and subsumed them under 'central sensations of senses', because increased neurophysiological knowledge made a literal interpretation of the original term impossible. In the fifth edition he developed a more precise model of central processes, described as 'sensory costimulation', and an additional idea of 'reproduced' or conditioned sensations. He mentions clinical evidence on the perception of eye and limb position of weight by paralysed and other subjects. This evidence is discussed in relation to modern theories. It is concluded that Wundt's later theories have some similarities with modern "hybrid' theories of efference-contingent afference.

Effects of ultraviolet radiation on photosynthesis and related enzyme reactions of marine macroalgae.

Changes in physiological parameters related to photosynthesis were studied in five macroalgal species from Spitsbergen (Monostroma arcticum, Laminaria solidungula, Alaria esculenta, Palmaria palmata, Phycodrys rubens) during a 72-h exposure to UV radiation. Maximal quantum yield of photochemistry (Fv/Fm) and maximal electron transport rate (ETRmax) were measured with a pulse-amplitude-modulated fluorometer; the activity of the Calvin cycle enzymes ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) were estimated using a photometric test. Proteins of crude extracts were separated by SDS gel electrophoresis and changes in cellular concentrations of Rubisco were determined. Moreover, the concentration of chlorophyll a (Ch1 a), and protein content, were measured photometrically. In all species, Ch1 a content, maximal quantum yield as well as ETRmax decreased during the UV treatment. Changes in ETRmax were related to the changes in the overall activity of Rubisco. Analysis of SDS gels showed that in P. rubens, L. solidungula, M. arcticum and A. esculenta decreasing Rubisco activity partly resulted from a degradation of the enzyme. However, in A. esculenta, the formation of a high-molecular-weight polypeptide was observed. In all species, the activity of Rubisco was more strongly impaired than that of G3PDH. Exposure to UV resulted in loss of total protein only in the deepwater species L. solidungula and P. rubens. The different sensitivities to UV exposure of the species tested reflect their zonation pattern in the field.

The essential transfer protein TraM binds to DNA as a tetramer.

The TraM proteins encoded by F-like plasmids are sequence specific DNA binding proteins that are essential for conjugative DNA transfer. We investigated the quarternary structure and the DNA binding properties of the TraM wild-type protein of the resistance plasmid R1 and two mutant forms thereof. Size-exclusion chromatography and differential scanning calorimetry showed that purified TraM protein (amino acids 2-127) forms stable tetramers in solution. A truncated version of the protein termed TraMM26 (amino acids 2-56) forms dimers. Thus, the dimerization and tetramerization domains can be assigned to the N-terminal and C-terminal domains of TraM, respectively. Further analyses using chemical cross-linking and light scattering corroborated the preferentially tetrameric nature of the protein but also suggest that TraM has a tendency to form higher aggregates. Band-shift and fluorescence spectroscopy investigations of TraM-DNA complexes revealed that the TraM protein is also tetrameric when bound to its minimal DNA binding site. The deduced binding constant in the range of 10(8) M(-1) demonstrated a very strong binding of TraM to its preferred DNA sequence. Secondary structure analysis based on CD measurements showed that TraM is mainly alpha-helical with a significant increase in alpha-helicity (48 to 58%) upon DNA-binding, indicating an induced fit mechanism.

Functional and mutational analysis of p19, a DNA transfer protein with muramidase activity.

Protein P19 encoded by the conjugative resistance plasmid R1 has been identified as being one member of a large family of muramidases encoded by bacteriophages and by type III and type IV secretion systems. We carried out a mutational analysis to investigate the function of protein P19 and used in vivo complementation assays to test those of several P19 mutants. The results indicated that conserved residues present in the presumed catalytic center of P19 are absolutely essential for its function in conjugation of plasmid R1 and infection by the RNA phage R17. Overexpression of protein P19 in an early growth phase resulted in a massive lysis of Escherichia coli cells in liquid culture, as indicated by a rapid and distinct decrease in cell culture densities after induction. Change of the proposed catalytic glutamate at position 44 to glutamine completely abolished this effect. P19-induced cell lysis was directly shown by transmission and scanning electron microscopy. Typically, P19-overexpressing cells showed bulges protruding from the cell surfaces. Our interpretation is that these protrusions arose from a localized and spatially confined disruption of the bacterial cell wall. To our knowledge such an effect has not previously been documented for any member of the lytic transglycosylase family. From the data presented here, we conclude that protein P19 possesses the proposed localized peptidoglycan-hydrolyzing activity. This activity would be a prerequisite for efficient penetration of the cell envelope by the DNA translocation complex encoded by the conjugative plasmid.

[Incidental chorangiocarcinoma. Case report, immunohistochemistry and theories of possible histogenesis]. / Inzidentelles Chorangiokarzinom. Fallbericht, Immunhistochemie und Theorien zur möglichen Histogenese.

We describe the third case world-wide of a chorangiocarcinoma, a tumour with an abnormal trophoblast proliferation in combination with a hypervascular chorangiosis of the villous stroma. The lesion was an incidential finding by a healthy 31-year-old woman, gravida 1, para 1 when the pregnancy was terminated at 34 weeks gestation because of fetal distress and intrauterine growth restriction. Hormonal levels were within the normal range. Mother and infant had an uneventful postpartum course. Immunohistochemical studies of the abnormal trophoblasts demonstrated strong immunoreactivity for HCG and in 80% for Ki 67. The semiquantitative expression of angiogenic growth factors (VEGF, bFGF, Ang-1 und Ang-2, PDGF) in the tumour trophoblasts was similar to that seen in the normal villi. The pathogenesis of this tumour with a villous vascular response is curious and unclear. Possibilities include the occurrence of a variant of a chorion carcinoma, the occurrence of a new tumour entity or of two separate lesions, a chorangioma and incidential chorion carcinoma, present together as a "collision" tumour. Another possibility is a composition tumour or a reactive lesion of trophoblasts and the villous vascular tree.

[Ectopic meningioma of the tonsil]. / Ektopes Meningeom in der Tonsille.

To our knowledge this is the first reported case of a primary extracranial meningioma located in the palatine tonsil. Immunohistochemical investigation of the tumour showed coexpression of vimentin and neuron-specific enolase (NSE). No staining was found with antibodies against cytokeratins KL1, 13/10, 8 and 18, epithelial membrane antigen EMA and melanoma protein (HMB-45). It seems justifiable to classify this tumour as an atypical meningioma because of the local increased mitotic activity.

[Morphology and prognosis of follicular thyroid cancer--a clinico-pathologic and DNA cytometric study of 95 tumors]. / Morphologie und Prognose des folliculären Schilddrüsencarcinoms--Eine klinisch-pathologische und DNS-cytometrische Untersuchung an 95 Tumoren.

A retrospective study of 95 follicular thyroid carcinomas was conducted to evaluate the prognostic value of different morphological and clinical features. The biological behaviour of these tumours was primarily influenced by presence or absence of a capsule type of confinement: the frequency of lethal outcome among widely invasive carcinomas was six times higher than among encapsulated neoplasms. Furthermore, dismal prognosis could be demonstrated for tumours occurring in older patients (with a sharp break in the prognosis at the age of 52 years) and for those lesions which displayed oxyphilic metaplasia. The same effect was shown for presence of lymph node metastasis, tumour invasion of the cervical soft tissue and, for the case of encapsulated carcinomas, distant haematogenous spread. Conversely, the degree of differentiation and the patients' sex proved to have no significant influence on prognosis. In 22 carcinomas, cytophotometric and flow-cytometric determinations of DNA values were performed. These procedures revealed to have only limited diagnostic value, since for the majority of the tumours, benignancy or malignancy could not be judged from the DNA histograms. However, DNA measurements proved to contribute valuable information for the prognosis in individual cases of widely invasive follicular carcinomas. The discussion focuses on the diagnostic, therapeutic and prognostic relevance of these findings and on their impact on subclassification of follicular thyroid carcinomas.