[Endoprosthetic replacement of the elbow joint in rheumatoid arthritis : Video article]. / Endoprothetischer Ersatz des Ellenbogengelenks bei rheumatoider Arthritis : Videobeitrag.

Endoprosthetic replacement of the elbow joint is comparatively rare with less than 100 cases per year in Germany. Patients with forms of rheumatism constitute the major proportion and they also show the significantly best results. The indications are assessed in a stage-adapted manner and depend mostly on the stability and the grade of bony destruction. An acceptable function of this joint, which transmits high strength but is not load bearing, is the main target. The accompanying video demonstrates the implantation of a total elbow endoprosthesis.

The anti SARS-CoV-2 activity of nanofibrous filter materials activated with metal clusters.

Nanofibrous filter materials were prepared by electrospinning a solution of 28 wt% poly(vinylidene fluoride) in N,N-dimethylacetamide with and without the addition of 2 wt% AgNO3, Cu(NO3)2·2.5H2O or ZnCl2. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy, inductively coupled plasma mass spectroscopy, thermogravimetric analysis, contact angle measurement, nitrogen sorption, and mercury intrusion porosimetry methods were used for the characterization of physical structure as well as the chemical composition of the electrospun materials. Particle filtration efficiency and antiviral activity against the SARS-CoV-2 alpha variant were tested in order to estimate the suitability of the prepared electrospun filter materials for application as indoor air filtration systems with virucidal properties. All filter materials prepared with salts demonstrated very high particle filtration efficiency (≥98.0%). The best antiviral activity was demonstrated by a material containing Cu(NO3)2·2.5H2O in the spinning solution, which displayed the decrease in the number of infectious virions by three orders of magnitude after a contact time of 12 h. Materials with the addition of AgNO3 and ZnCl2 decreased the number of infectious virions after the same contact time by only ∼8 and ∼11 times, respectively.

A noninvasive analysis of urinary musculoskeletal collagen metabolism markers from rhesus monkeys subject to chronic hypergravity.

A decrease in load-bearing activity, as experienced during spaceflight or immobilization, affects the musculoskeletal system in animals and humans, resulting in the loss of bone and connective tissue. It has been suggested that hypergravity (HG) can counteract the deleterious effects of microgravity-induced musculoskeletal resorption. However, little consensus information has been collected on the noninvasive measurement of collagen degradation products associated with enhanced load-bearing stress on the skeleton. The purpose of this study is to assess the urinary collagen metabolic profiles of rhesus monkeys (Macaca mulatta) during 1) 2 wk of basal 1 G (pre-HG), 2) 2 wk of HG (2 G), and 3) two periods of post-HG recovery (1 G). Urine was collected over a 24-h period from six individual rhesus monkeys. Hydroxyproline (Hyp) and collagen cross-links (hydroxylysylpyridinoline and lysylpyridinoline) were measured by reverse-phase HPLC. Urinary calcium, measured by atomic absorption, and creatinine were also assayed. The results indicate no changes in nonreducible cross-links and Hyp during HG. Collagen cross-link biomarker levels were significantly elevated during the 2nd wk of HG. Urinary calcium content was significantly lower during HG than during the 1-G control period, suggesting calcium retention by the body. We conclude that there is an adaptation of the nonhuman primate musculoskeletal system during hyperloading and that noninvasive measurements of musculoskeletal biomarkers can be used as indicators of collagen and mineral metabolism during HG and recovery in nonhuman primates.

Optically stimulated luminescence of some thermoluminescent detectors as an indicator of absorbed radiation dose.

Stimulation spectra of several TLD materials in the short-wave spectral region are measured using the optically stimulated afterglow (OSA) method for determination of absorbed dose. Optical stimulation spectra are studied in the region of wavelengths lower than those of emission spectra. The effective optical stimulation hands have been found for examined materials in the regions of wavelengths which overlap with fluorescence excitation bands. Application of short-wave OSA bands for determination of absorbed dose is analysed.

The carotid rete and artiodactyl success.

Since the Eocene, the diversity of artiodactyls has increased while that of perissodactyls has decreased. Reasons given for this contrasting pattern are that the evolution of a ruminant digestive tract and improved locomotion in artiodactyls were adaptively advantageous in the highly seasonal post-Eocene climate. We suggest that evolution of a carotid rete, a structure highly developed in artiodactyls but absent in perissodactyls, was at least as important. The rete confers an ability to regulate brain temperature independently of body temperature. The net effect is that in hot ambient conditions artiodactyls are able to conserve energy and water, and in cold ambient conditions they are able to conserve body temperature. In perissodactyls, brain and body temperature change in parallel and thermoregulation requires abundant food and water to warm/cool the body. Consequently, perissodactyls occupy habitats of low seasonality and rich in food and water, such as tropical forests. Conversely, the increased thermoregulatory flexibility of artiodactyls has facilitated invasion of new adaptive zones ranging from the Arctic Circle to deserts and tropical savannahs.

Thermoregulation in pronghorn antelope (Antilocapra americana, Ord) in winter.

Conservation of energy is a prerequisite thermoregulatory strategy for survival in northern hemisphere winters. We have used thermistor/data logger assemblies to measure temperatures in the brain, carotid artery, jugular vein and abdominal cavity, in pronghorn antelope to determine their winter body temperature and to investigate whether the carotid rete has a survival role. Over the study period mean black globe and air temperature were -0.5+/-3.2 degrees C and -2.0+/-3.4 degrees C, respectively, and mean daytime solar radiation was approximately 186 W m(-2). Brain temperature (T(brain), 39.3+/-0.3 degrees C) was higher than carotid blood temperature (T(carotid), 38.5+/-0.4 degrees C), and higher than jugular temperature (T(jugular), 37.9+/-0.7 degrees C). Minimum T(brain) (38.5+/-0.4 degrees C) and T(carotid) (37.8+/-0.2 degrees C) in winter were higher than the minimum T(brain) (37.7+/-0.5 degrees C) and T(carotid) (36.4+/-0.8 degrees C) in summer that we have reported previously. Compared with summer, winter body temperature patterns were characterized by an absence of selective brain cooling (SBC), a higher range of T(brain), a range of T(carotid) that was significantly narrower (1.8 degrees C) than in summer (3.1 degrees C), and changes in T(carotid) and T(brain) that were more highly correlated (r=0.99 in winter vs r=0.83 in summer). These findings suggest that in winter the effects of the carotid rete are reduced, which eliminates SBC and prevents independent regulation of T(brain), thus coupling T(brain) to T(carotid). The net effect is that T(carotid) varies little. A possible consequence is depression of metabolism, with the survival advantage of conservation of energy. These findings also suggest that the carotid rete has wider thermoregulatory effects than its traditional SBC function.

Thermoregulation in pronghorn antelope (Antilocapra americana Ord) in the summer.

We have used thermistor/data logger assemblies to measure temperatures in the brain, carotid artery, jugular vein and abdominal cavity, and subcutaneously, in five pronghorn antelope over a summer in Wyoming. Globe and air temperature varied by up to approximately 50 degrees C daily during the summer and maximum solar radiation was approximately 900 W m(-2). Brain temperature (38.9+/-0.3 degrees C) was consistently approximately 0.2-0.5 degrees C higher than carotid blood temperature (38.6+/-0.3 degrees C), which was the same as abdominal temperature (38.8+/-0.4 degrees C). Jugular blood temperature (38.0+/-0.4 degrees C) varied, probably because of changes in Respiratory Evaporative Heat Loss (REHL), and was lower than other temperatures. Subcutaneous temperature (38.3+/-0.6 degrees C) varied, probably because of peripheral vasoactivity, but on average was similar to other temperatures. Carotid blood temperature had a circadian/nycthemeral rhythm weakly but significantly (r=0.634) linked to the time of sunrise, of amplitude 0.8+/-0.1 degrees C. There were daily variations of up to 2.3 degrees C in carotid body temperature in individual animals. An average range of carotid blood temperature of 3.1+/-0.4 degrees C over the study period was recorded for the group, which was significantly wider than the average variation in brain temperature (2.3+/-0.6 degrees C). Minimum carotid temperature (36.4+/-0.8 degrees C) was significantly lower than minimum brain temperature (37.7+/-0.5 degrees C), but maximum brain and carotid temperatures were similar. Brain temperature was kept relatively constant by a combination of warming at low carotid temperatures and cooling at high carotid temperatures and so varied less than carotid temperature. This regulation of brain temperature may be the origin of the amplitude of the average variation in carotid temperature found, and may confer a survival advantage.

Quality control in haemostasis.

Laboratory investigation of the haemostatic system deserves particular procedures in the quality control of analytical variables as well as preanalytical variables. This paper reviews the precautions that have to be taken in the blood prelevement, the transport of the tubes and the performance of the laboratory tests aimed to investigate the haemostatic system in order to obtain reliable results.

Comparative study of antiphospholipid antibody detection in eleven Belgian laboratories.

Twenty-six plasma samples have been sent to 11 different Belgian laboratories in order to detect the presence of antiphospholipid antibodies, either by immunological methods and/or by coagulation tests. A good concordance between laboratories was observed for coagulation tests. Laboratories using detection tests and performing mixing procedures and neutralisation procedures displayed the highest sensitivity as compared with laboratories which did not perform one of these two latter procedures. The concordance between laboratories for the immunological methods was much worse as compared with coagulation tests. This may be attributable either to an intrinsic problem of the immunological tests or to a selection bias due the fact that the plasmas used in this study were selected in coagulation laboratories only where the chance to find a lupus anticoagulant positive/ELISA antiphospholipid negative sample is high.