A novel,noncanonical mechanism of cytoplasmic polyadenylation operates in Drosophila embryogenesis

Cytoplasmic polyadenylation is a widespread mechanism to regulate mRNA translation that requires two sequences in the 3′ untranslated region (UTR) of vertebrate substrates: the polyadenylation hexanucleotide, and the cytoplasmic polyadenylation element (CPE). Using a cell-free Drosophila system, we show that these signals are not relevant for Toll polyadenylation but, instead, a “polyadenylation region” (PR) is necessary. Competition experiments indicate that PR-mediated polyadenylation is required for viability and is mechanistically distinct from the CPE/hexanucleotide-mediated process. These data indicate that Toll mRNA is polyadenylated by a noncanonical mechanism, and suggest that a novel machinery functions for cytoplasmic polyadenylation during Drosophila embryogenesis.     

Micromotions in the primary fixation of cementless femoral stem prostheses

Summary Thirty cementless femoral stems of six different types of hip endoprostheses were impanted in femurs taken at autopsy and underwent static loading and afterwards dynamic loading of 50000 cycles to simulate walking during the early months after implantation. After that, the static load tests were performed again. During both static load series a certain amount of micromotion between stem and implantation bed occurred in the frontal and sagittal planes and also during rotation. The six prostheses exhibited clearly differing results. The influence of dynamic load on the extent of micromotion was small.     

Intravenous immunoglobulin in the treatment of malignant epilepsy in children

15 children with malignant epilepsy showing no response to conventional antiepileptic drugs or hormone therapy were administered intravenous immunoglobulin (Endobulin, Immuno) at a dosage of 400 mg/kg per day on the 1st and 15th day and subsequently every three weeks for 6 months. 7 of these 15 patients showed IgG2 subclass deficiency. A significant reduction in attacks, or even absence of attacks was observed in 10 out of 15 children after six months of intravenous immunoglobulin therapy. Apart from one patient with ringchromosomopathy, all the children with IgG2 subclass deficiency responded to this therapy. The reduction of attacks after i.v. immunoglobulin therapy correlates with the improvement or normalization of the EEG findings. At present, the authors consider the number of patients still too small to make a final assessment, but they believe that intravenous immunoglobulin holds an important position in the treatment of malignant epilepsy in childhood.     

Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood-derived platelets and apheresis platelets

BACKGROUND: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system. STUDY DESIGN AND METHODS: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux). RESULTS: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture. CONCLUSION: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.     

Microarchitecture of the Radial Head and Its Changes in Aging

Fractures of the radial head are common; however, it remains to be determined whether the radial head has to be considered as a typical location for fractures associated with osteoporosis. To investigate whether the human radial head shows structural changes during aging, we analyzed 30 left and 30 right human radial heads taken from 30 individuals. The specimens taken from the left side were analyzed by peripheral quantitative computed tomography (pQCT) and micro-CT. The specimens taken from the right elbow joint were analyzed by radiography and histomorphometry. In these specimens pQCT revealed a significant decrease of total and cortical bone mineral density (BMD_to BMD_co) with aging, regardless of sex. Histomorphometry revealed a significant reduction of cortical thickness (Ct.Th), bone volume per tissue volume (BV/TV), and trabecular thickness (Tb.Th) in male and female specimens. In this context, mean BV/TV and mean trabecular number (Tb.N) values were significantly lower and, accordingly, mean trabecular separation (Tb.Sp) was significantly higher in female samples. The presented study demonstrates that the radial head is a skeletal site where different age- and sex-related changes of the bone structure become manifest. These microarchitectural changes might contribute to the pathogenesis of radial head fractures, especially in aged female patients where trabecular parameters (BMD_tr and Tb.Sp) change significantly for the worse compared to male patients.     

CUTANEOUS MERCURY GRANULOMA

Mercury poisoning arising from cutaneous mercury deposition is highly unusual. The diagnosis is difficult to make when no history of a penetrating injury is given. We report such a case and discuss investigation and management. Other cutaneous manifestations of mercury exposure are outlined.     

Inhibitory cholinergic effects on the autonomously contractile bulbus cordis branchialis of the cephalopod Sepia officinalis L.

In vitro experiments were performed on a standardized preparation of the autonomously contractile bulbus cordis branchialis of the branchial heart of Sepia officinalis to investigate its cholinergic neuroregulation. Apart from acetylcholine, nicotine and carbachol (nicotinic agonists), the muscarinic agonists muscarine, arecoline, pilocarpine, and oxotremorine also exerted concentration-dependent negative inotropic effects on the preparations. As both the muscarinic antagonist quinuclidinylbenzilate and the nicotinic antagonist alpha-bungarotoxin blocked the ACh action there might be a special, possibly mixed muscarinic/nicotinic ACh-receptor system in the myocytes of the bulbus cordis branchialis, which is different from the cholinergic receptor in the central part of the branchial heart.