Präsenzkurse unter Lockdown-Bedingungen – eine Herausforderung

Hintergrund

Methode

Ergebnis

Schlussfolgerung

Post-mortem interval estimation of human skeletal remains by micro-computed tomography, mid-infrared microscopic imaging and energy dispersive X-ray mapping

In this study different state-of-the-art visualization methods such as micro-computed tomography (micro-CT), mid-infrared (MIR) microscopic imaging and energy dispersive X-ray (EDS) mapping were evaluated to study human skeletal remains for the determination of the post-mortem interval (PMI). PMI specific features were identified and visualized by overlaying molecular imaging data and morphological tissue structures generated by radiological techniques and microscopic images gained from confocal microscopy (Infinite Focus (IFM)). In this way, a more distinct picture concerning processes during the PMI as well as a more realistic approximation of the PMI were achieved. It could be demonstrated that the gained result in combination with multivariate data analysis can be used to predict the Ca/C ratio and bone volume (BV) over total volume (TV) for PMI estimation. Statistical limitation of this study is the small sample size, and future work will be based on more specimens to develop a screening tool for PMI based on the outcome of this multidimensional approach.

Clathrates Ba(8){Zn,Cd}(x)Si(46-x), x∼7: synthesis, crystal structure and thermoelectric properties

Novel ternary type-I clathrate compounds Ba(8){Zn,Cd}(x)Si(46-x), x∼7 have been synthesized from the elements by melting and reacting in quartz ampoules. Structural investigations for both compounds, i.e. x-ray single-crystal data at 300, 200 and 100 K for Ba(8)Zn(7)Si(39) and Rietveld data for Ba(8)Cd(7)Si(39), confirm cubic primitive symmetry consistent with the space group type [Formula: see text] (a(Ba(8)Zn(7)Si(39)) = 1.043 72(1) nm; a(Ba(8)Cd(7)Si(39)) = 1.058 66(3) nm). Whereas for Ba(8)Zn(7)Si(39) site 16i is completely occupied by Si atoms, a random atom distribution with different Zn/Si ratio exists for the two sites, 6d (0.77Zn+0.23Si) and 24k (0.91Si+0.09Zn). No vacancies are encountered and all atom sites are fully occupied. This atom distribution is independent of temperature. Rietveld refinements for Ba(8)Cd(7)Si(39) show that the 6d site is fully occupied by Cd atoms, leaving only the 24k site for a random occupation (0.96Si+0.04Cd) consistent with the chemical formula Ba(8)Cd(7)Si(39). The temperature-dependent x-ray spectra for Ba(8)Zn(7)Si(39) define an Einstein mode, Θ(E,U33) = 80 K. Studies of transport properties show electrons as the majority charge carriers in the system. Although the Cd- and Zn-based samples are isoelectronic, a significantly different electronic transport points towards substantial differences in the electronic density of states in both cases.

Accumulation of toxicants in tadpoles of the common frog (Rana temporaria) in high mountains

We analyzed the accumulation of inorganic and organic toxicants in tadpoles from nine populations of the common frog (Rana temporaria) at different altitudes of the Hohe Tauern National Park in Austria). Lead and cadmium concentrations in tadpoles increased with the acidity and metal-to-HCO3(-) ratio in the water exceeding those found in tadpoles from agricultural areas. Organochlorines (DDTs, polychlorinated biphenyls, lindane) and polyaromatic hydrocarbons were present in all of the populations, but only DDTs accumulated significantly compared with the concentrations in their diet.

Low-level chromosome 12 amplification in a primary lipoma of the lung: evidence for a pathogenetic relationship with common adipose tissue tumors

Cytogenetic analysis of a primary lipoma of the lung removed from a 56-year-old woman revealed the presence of a supernumerary marker chromosome in all metaphase cells analyzed; namely, 47,XX,+mar. To the best of our knowledge, this is the first cytogenetic description of a primary lipoma of lung. Genetic analysis of intramuscular lipoma, atypical lipoma, and well-differentiated liposarcoma have revealed the presence of one to three supernumerary ring or giant marker chromosomes composed of chromosome 12 segments as the characteristic anomaly. The marker chromosome in the present case was shown to be composed entirely of chromosome 12 material by subsequent analysis with a chromosome 12-specific paint probe and fluorescence in situ hybridization. Thus, analogous to intramuscular lipoma, atypical lipoma, and well-differentiated liposarcoma, extra chromosome 12 material is present. These findings support a pathogenetic relationship between this lipoma of unusual anatomic location and common adipose tissue tumors.

Metabolism and detoxification of nitrite by trout hepatocytes

Nitrite (NO2-) is one of the most important toxicants to fish. Freshwater fish are especially sensitive, particularly salmonids. Nitrite uptake is thought to occur via the HCO3-, Cl- -exchanger at the gill epithelia with nitrite substituting for chloride. In this way freshwater fish accumulate nitrite in the blood up to 100-fold from the surrounding water. Another source, endogenous nitrite as a degradation product of nitric oxide, rarely leads to pharmacologically relevant concentrations. We developed a new method for the determination of nitrate (NO3-) in biological samples and used it to measure nitrite oxidation in isolated rainbow trout (Oncorhynchus mykiss) hepatocytes which were found to detoxify nitrite to the almost non-toxic nitrate. Detoxification is inhibited by 0.05 mM bumetanide and 0.1 mM furosemide but not by SITS and DITS, suggesting the involvement of the Na+, K+, 2Cl- -cotransporter with nitrite or nitrate substituting for chloride. Oxidation of nitrite is strongly accelerated by 0.05 mM uric acid. The efficacy of this antioxidant suggests that similar reactions are involved as known for haemoglobin [33]. However, in the case of trout liver also membrane bound detoxificating activity can be observed which is also enhanced by uric acid. ATP concentrations remained constant in the hepatocytes during all experiments demonstrating that hepatocyte energy status was not influenced by nitrite oxidation. Thus nitrite resistance in fish is governed by at least two mechanisms, nitrite uptake and the rate of detoxification. It is unknown whether fish actually differ in their ability to distinguish between chloride and nitrite during branchial uptake, but evidence presented in this paper suggests a significant contribution of detoxification pathways to a possible nitrite tolerance of fish.

Ascorbate-2-sulfate sulfohydrolase in fish and mammal. Comparative characterization and possible involvement in ascorbate metabolism

1. The new assay conditions were determined for crude and purified enzyme ascorbate-2-sulfate sulfohydrolase from liver tissues of two fish species and bovine. 2. The major departure from the existing indirect method, based on reduction of 2,6-dichlorophenolindophenol (DCIP) by released ascorbic acid and change from pink-blue to a colorless molecule, takes into account the shift of maximum absorbance of DCIP from 516 nm at pH 5.14 to 600 nm at pH 6.5. 3. The direct method is based on colorimetric assay of liberated ascorbic acid including correction for interfering substances. The optimum pH for both fish ascorbate sulfatases was 5.5. 4. The Km for bovine ascorbate sulfatase was confirmed to be approximately 7 mM at 37 degrees C. 5. Partly purified ascorbate-sulfate sulfohydrolase has a Km value in rainbow trout of 0.4 mM and it changes very little in the range of water temperatures characteristic for this stenothermic fish species. 6. In eurythermic chub, the Km values increased from 1.2 to 4.3 mM with rising temperatures.

Oxidative degradation of high molecular weight chlorolignin by manganese peroxidase of Phanerochaete chrysosporium

Phanerochaete chrysosporium was able to degrade high molecular weight chlorolignins (Mr greater than 30,000) from bleach plant effluents, although a direct contact between ligninolytic enzymes and chlorolignin was prevented by a dialysis tubing. In the absence of the enzymes, Mn3+ depolymerized chlorolignin when complexed with lactate causing the color, chemical oxygen demand (COD) and dry weight to decrease by 80%, 60% and 40%, respectively. Manganese peroxidase effectively catalyzed the depolymerization of chlorolignin in the presence of Mn2+ and H2O2. It can be concluded from these results that manganese peroxidase plays the major role in the initial breakdown and decolorization of high molecular weight chlorolignin in bleach plant effluents by P. chrysosporium in vivo.

[Amputation of the leg in arterial occlusive disease]

The until recently held opinion that above-knee amputations were the method of choice for treating stage IV chronic occlusive arterial disease, is outdated. Determining the appropriate level for amputation in patients with peripheral arterial obstruction is difficult, and requires much experience. Successful fitting of a prosthetic device and subsequent rehabilitation depend not only on the patient's bodily and emotional reserves, but also on the operative technique employed. The more distal the amputation, the better is the prognosis for satisfactory prosthetic function and social reintegration. A total of 280 amputations on 268 patients was performed over a 48-month period. In 181 patients (68%) primary healing occurred without complications. Total mortality was 10%, occurring mainly in the group of above-knee amputees. The majority of local wound complications was found in transmetatarsal resections and below-knee amputations. A total of 42 patients (15%) underwent re-amputation. Only half of the above-knee amputees could be fitted with a prosthesis and rehabilitated, whereas nearly all patients amputated more distally experienced satisfactory outcomes in this respect.

Intravenous ofloxacin in severe infections

The efficacy and tolerance of intravenous ofloxacin was studied in 70 patients suffering from soft tissue infections (n = 33), intra-abdominal abscesses (n = 14), septicaemia (n = 12), pneumonia (n = 9) and brucellosis (n = 2). The average daily dose was 6 mg/kg divided into two doses. Pathogens treated included Enterobacter cloacae (n = 14), Escherichia coli (n = 12), Staphylococcus aureus (n = 13), Pseudomonas aeruginosa (n = 11), Klebsiella pneumoniae (n = 10), Enterococcus faecalis (n = 8) and Streptococcus spp. (n = 5). Most patients had several underlying diseases. Most of the patients had received other antibiotic therapy without success. Clinically, 41% were considered cured, 19% improved and 30% failed to respond. Bacteriologically, pathogens were eradicated in 52.5% and persisted in 22.5%. Adverse reactions included an anaphylactoid reaction, abnormal liver function (n = 13) and insomnia (n = 2). This study suggests that higher doses of ofloxacin may be needed in deep seated infections.

Prevention of stress-induced erosive gastritis by parenteral administration of arachidonic acid

Stress-induced mucosal ulcerations are associated with a decreased synthesis of mucosal prostaglandin (PG) E2. This phenomenon is poorly understood. To investigate whether it is due to a decreased availability of the necessary substrates to the mucosa, four groups of 10 Holtzman rats were studied: group 1 received normal saline by intraperitoneal (ip) injection; group 2 also received ip normal saline, then were submitted to stress, by the cold restraint method; group 3 received a solution of arachidonic acid (AA) ip; and group 4 also received ip AA, then were submitted to stress. After sacrifice, the number of gastric ulcerations were counted and specimens of nonulcerated mucosa were assayed for PGE2 by high-performance liquid chromatography; the mean numbers of ulcers were 0, 5.8, 0.8, and 3 and the mean levels of PGE2 were 55, 41, 125, and 62 pg/mg of wet tissue for groups 1, 2, 3, and 4, respectively. It is concluded that parenteral administration of AA reduces but does not completely eliminate stress-induced gastric ulcerations and that the stressed animals synthesized half as much PGE2 as the nonstressed ones after ip administration of equal amounts of AA, suggesting that stress reduces the availability of AA to the gastric mucosa, possibly by vascular spasm.

The surgical implications of purpura fulminans

Purpura fulminans is an uncommon catastrophic syndrome that occurs in children, typically one to four weeks after a seemingly benign infectious process. The child usually presents with a high fever, purpuric ecchymosis, hypotension, disseminated intravascular coagulation, and gangrene of the extremities. We have recently treated six children, whose mean age was 22 months; three were male and three were female. Five of the six had a change of mental status upon initial examination. Their mean temperature was 104 degrees F. All six children had purpuric involvement of their extremities; three had involvement of their hands, two had involvement of their faces, and two had involvement of their trunks. All had absent palpable pulses and sluggish capillary refill in the involved hands and feet. Two patients died shortly after admission as a result of severe end-stage sepsis. The platelet counts in these two patients, and the white blood cell counts were markedly depressed. The mean platelet count of the survivors was 370,000 and the mean white blood cell count was 25,000. Lumbar punctures were positive for bacterial meningitis in five patients and viral meningitis in one patient. All patients were treated with intravenous heparin. Of the four survivors, two lost significant tissue and required multiple plastic reconstructive procedures, and two improved on heparin alone with no tissue loss. In addition to systemic support and intravenous antibiotics, the mainstay of treatment is one of immediate heparinization and a continuous heparin drip. Heparin prevents subsequent small vessel thrombosis and limits tissue loss due to ongoing purpura. Conservative management of the purpuric lesions is the treatment of choice until final demarcation occurs.

[Splenic cyst--a rare cause of epigastric expansion]

Cysts are rare lesions of the spleen, and may be divided into parasitic and non-parasitic types. After the parasitic cysts, the second most frequent group is the (secondary) posttraumatic form of non-parasitic cysts. The primary form (congenital and neoplastic) of the latter is the least frequent. Whereas splenectomy was the treatment of choice for lienal cysts until a few years ago, a change has occurred in the techniques of splenic salvage. Against the background of a case report of a primary epidermoid cyst the etiology, diagnostic measures, and the recent developments in conserving spleen surgery are discussed.

Health care financing policy for hospitalized pediatric patients

Prospective hospital payment systems using the federal Medicare DRG payment model are changing hospital reimbursement. Currently, many states have adopted diagnosis related group (DRG) prospective "all payer systems" using the federal model. All payer systems, whereby Medicaid, Blue Cross, and other commercial insurers pay by the DRG mode, prevent cost shifting between payers. New York state has used an all payer system since Jan 1, 1988. This study simulated DRG all payer methods for a large sample (N = 16,084) of pediatric patients for a three-year period using the New York DRG all payer reimbursement system now in effect. Medicaid pediatric patients had (adjusted for DRG weight index) a longer hospital stay and greater total hospital cost compared with pediatric patients from Blue Cross and other commercial payers. Medicaid pediatric patients also had a greater severity of illness compared with patients from Blue Cross and other payers. Pediatric patients in all payment groups (ie, Medicaid, Blue Cross, and other commercial insurers) generated financial risk under the DRG all payer scheme. Medicaid pediatric patients generated the greatest financial risk, however. These data suggest that state and private payers may be under-reimbursing for the care of the hospitalized pediatric patient using the DRG prospective hospital payment scheme. Health care financing policy for pediatric patients may limit both access and quality of care.

Hospital resource consumption and outcome. Route of admission and age for hospitalized otolaryngology patients

Hospitals and physicians face new payment mechanisms that provide incentives to study health policy, management, and economics. The purpose of this study was to analyze hospital resource consumption and outcome based on age and the route of hospital admission (emergency [ER] vs nonemergency [non-ER]). We analyzed all adult otolaryngology hospital admissions (N = 1589) during a three-year period (1985 through 1987) to a large northeastern academic medical center. Hospital resource consumption, measured by hospital length of stay and total hospital cost per patient, rose with age for ER and non-ER admissions. Severity of illness, clinical resource utilization, and mortality demonstrated these same characteristics. Diagnosis related group prospective hospital payment generated financial risk for ER admissions and elderly patients. Analysis demonstrated ER admission as more predictive of subsequent hospital resource consumption and outcome with changes in age compared with non-ER admission. Our findings suggest that in the future physicians and hospitals may find that age and the route of admission may be useful in stratifying patients regarding cost and outcome.

Distribution and properties of lactate dehydrogenase isoenzymes in red and white muscle of freshwater fish

The distribution and kinetics of LDH isoenzymes in red and white muscles of 5 species of salmonids, 4 species of cyprinids and one coregonid species were studied. In all species the white muscles are characterized by the occurrence of only the most cathodic isoenzymes, or groups of isoenzymes. The red muscles contained either the full set of isoenzymes (cyprinids) or a selection in which the anodic forms dominated (salmonids, coregonid). The most striking difference between the two types of muscle was met inCoregonus sp. The temperature profiles of pyruvate affinity are similar in all species of fish studied. On the other hand, Km(pyr) values and degree of pyruvate inhibition are closely related and vary greatly with temperature, with the taxonomic position (and thus biology) of the species, and with electrophoresic mobility of the isoenzyme. Highest affinity and strongest inhibition occurred in the anodic (H4) isoenzymes of cyprinids at low temperature; lowest affinity and zero inhibition in the cathodic isoenzymes (Mα4 → Mβ4) of salmonids and coregonids at high temperature. In salmonids the more recently duplicated loci of the M-group of isoenzymes possess identical Km values at all temperatures, whereas the two older M and H loci differ greatly in this respect. Thus the more recent duplication of LDH loci in salmonids and coregonids may be seen as a mechanism by which the tetramers required for LDH activity can be constructed from more closely related subunits than are provided by the older M and H loci.Some problems in connection with the determination of the kinetic constants of the lactate oxidase reaction are discussed and it is suggested that an alkaline, pyruvate trapping system provides conditions which are more realistic than those of other assay systems. The Km(lactate) values found are in the biological range and, at 20°C, provide further circumstantial evidence that the red muscles of fish should be capable of oxidizing the lactate produced by the white muscles during strenuous exercise. At 4°C the Km(lactate) values are abnormally high in all muscle preparations and thus are not correlated with the Km(pyruvate) values which are lowest at this temperature.

Screening for organic acids in fish tissues with special reference to the distribution of taurine inRutilus rutilus L

A liquid chromatographic method for rapid profiling of some organic acids and other compounds of physiological interest in fish tissues is presented. The method provides the detection of α-ketoglutaric, malic and pyruvic acid and is optimized for the quantitation of citric, phosphoric, succinic, lactic and fumaric acids, as well as glucose and especially taurine. These substances were separated in a single analytical run on a cation exchange column with dilute sulfuric acid as the elutant. The effluent was monitored by a refractive index or an UV detector at 208 nm wavelength. Resolution was satisfactory. No further treatment was found to be necessary when samples were deproteinized with perchloric acid. Taurine (2-aminoethansulfonic acid), not previously described in the roach (Rutilus rutilus L.), occurs in considerable amounts in red and white muscle and heart tissue. However, it is also present in all other tissues.

A problem in the radiochemical assay of glucose-6-phosphatase in muscle

A radiochemical assay for glucose-6-phosphatase, which depends on the absorption of radiolabelled substrate on to a nascent precipitate of BaSO4 and Zn(OH)2, can give rise to erroneously high activities. Adsorption on to a Fe(OH)3 precipitate does not expose the incubation medium to extreme alkaline conditions and provides a satisfactory and simple assay. This method demonstrates a very low activity of the enzyme in mammalian muscle, in contrast with previous findings.

[Hand injuries due to agricultural accidents (author's transl)]

Agricultural injuries are common in childhood. About a quarter of the cases shows injuries of the hand. These are sometimes very extensive and, particularly in younger children, open fractures or amputation of one or more fingers are often found. Machines for peeling maize-cobs, cutting and mixing fodder, and tractors are those implements which cause the commonest serious injuries to the hand. The high percentage of children under eight years of age among our cases clearly indicates the small account of safety measures held among country people. For successful accident-prevention it is therefore necessary to increase the consciousness of danger to children among the farming population by means of detailed information, as well as to carry out improvements on the machines themselves.