[Mobile C-arm-Radiation exposure and workflow killer? : Potential of an innovative assistance system for intraoperative positioning].

Despite its versatile applicability the intraoperative use of a mobile C‑arm is often problematic and potentially associated with increased radiation exposure for both the patient and the personnel. In particular, the correct positioning for adequate imaging can become a problem as the nonsterile circulating nurse has to coordinate the various maneuvers together with the surgeon without having a good view of the surgical field. The sluggishness of the equipment and the intraoperative setting (sterile borders, additional hardware, etc.

RAY-POS: a LIDAR-based assistance system for intraoperative repositioning of mobile C-arms without external aids.

Purpose: In current clinical practice, intraoperative repositioning of mobile C-arms is challenging due to a lack of visual cues and efficient guiding tools. This can be detrimental to the surgical workflow and lead to additional radiation burdens for both patient and personnel. To overcome this problem, we present our novel approach Lidar-based X-ray Positioning for Mobile C-arms (RAY-POS) for assisting circulating nurses during intraoperative C-arm repositioning without requiring external aids.

[Functional outcome of 111 metatarsal fractures following conservative in comparison to operative treatment].

Background: Fractures of the metatarsal bones are common injuries of the foot and particularly occur in patients aged 40-50 years. Especially multiple metatarsal fractures can lead to permanent limitations. Therefore, the aim of this study was to investigate the functional outcome of metatarsal fractures after conservative and surgical treatment using a validated self-reported patient-based outcome questionnaire.

Does implant removal of superior clavicle plate osteosynthesis affect the functional outcome: a prospective trial.

Background: Elective implant removal (IR) accounts for up to 30% of all orthopaedic surgeries. While there is general acceptance about the need of implant removal for obvious reasons, such as infections or implant failure, little is known about the beneficial aspects in cases of minor reasons such as patients' wish for IR. Therefore, we initiated this study to define patients' benefit of elective implant removal following plate osteosynthesis of displaced clavicle fractures.

Long-term Results After Arthroscopic Repair of Isolated Subscapularis Tears.

Background: Although some reports have presented short- to midterm results after arthroscopic repair of isolated subscapularis (SSC) tendon tears, long-term evaluation is still lacking.

Hypothesis: Long-term results after arthroscopic repair of isolated SSC tears are comparable with the functional and radiological short- to midterm outcomes described in the literature.

Study Design: Case series, Level of evidence, 4.

Cellular uptake of imatinib into leukemic cells is independent of human organic cation transporter 1 (OCT1).

Purpose: In addition to mutated BCR-ABL1 kinase, the organic cation transporter 1 (OCT1, encoded by SLC22A1) has been considered to contribute to imatinib resistance in patients with chronic myeloid leukemia (CML). As data are conflicting as to whether OCT1 transports imatinib and may serve as a clinical biomarker, we used a combination of different approaches including animal experiments to elucidate comprehensively the impact of OCT1 on cellular imatinib uptake.

Experimental Design: Transport of imatinib was studied using OCT1-expressing Xenopus oocytes, mammalian cell lines (HEK293, MDCK, V79) stably expressing OCT1, human leukemic cells, and Oct1-knockout mice.

Five amino acids in the innermost cavity of the substrate binding cleft of organic cation transporter 1 interact with extracellular and intracellular corticosterone.

We have shown previously that Leu447 and Gln448 in the transmembrane helix (TMH) 10 of rat organic cation transporter rOCT1 are critical for inhibition of cation uptake by corticosterone. Here, we tested whether the affinity of corticosterone is different when applied from the extracellular or intracellular side. The affinity of corticosterone was determined by measuring the inhibition of currents induced by tetraethylammonium(+) (TEA(+)) in Xenopus laevis oocytes expressing rOCT1.

Transport of lamivudine [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] and high-affinity interaction of nucleoside reverse transcriptase inhibitors with human organic cation transporters 1, 2, and 3.

Nucleoside reverse transcriptase inhibitors (NRTIs) need to enter cells to act against the HIV-1. Human organic cation transporters (hOCT1-3) are expressed and active in CD4+ T cells, the main target of HIV-1, and have been associated with antiviral uptake in different tissues. In this study, we examined whether NRTIs interact and are substrates of hOCT in cells stably expressing these transporters.

Identification of cysteines in rat organic cation transporters rOCT1 (C322, C451) and rOCT2 (C451) critical for transport activity and substrate affinity.

Effects of the sulfhydryl reagent methylmethanethiosulfonate (MMTS) on functions of organic cation transporters (OCTs) were investigated. Currents induced by 10 mM choline [I(max(choline))] in Xenopus laevis oocytes expressing rat OCT1 (rOCT1) were increased four- to ninefold after 30-s incubation with 5 mM MMTS whereas I(max(choline)) by rat OCT2 was 70% decreased. MMTS activated the rOCT1 transporter within the plasma membrane without changing stoichiometry between translocated charge and cation.

Polyspecific organic cation transporters: structure, function, physiological roles, and biopharmaceutical implications.

The body is equipped with broad-specificity transporters for the excretion and distribution of endogeneous organic cations and for the uptake, elimination and distribution of cationic drugs, toxins and environmental waste products. This group of transporters consists of the electrogenic cation transporters OCT1-3 (SLC22A1-3), the cation and carnitine transporters OCTN1 (SLC22A4), OCTN2 (SLC22A5) and OCT6 (SLC22A16), and the proton/cation antiporters MATE1, MATE2-K and MATE2-B. The transporters show broadly overlapping sites of expression in many tissues such as small intestine, liver, kidney, heart, skeletal muscle, placenta, lung, brain, cells of the immune system, and tumors.

Polyspecific cation transporters mediate luminal release of acetylcholine from bronchial epithelium.

In airway epithelia, non-neuronal cholinergic regulations have been described; however, the route for acetylcholine (ACh) release has not been verified. To investigate whether organic cation transporters (OCTs) serve this function, we studied the expression of OCTs in airway epithelia and their capability to translocate ACh. Using immunohistochemistry in rats and humans, OCT1, OCT2, and OCT3 were localized to the luminal membrane of ciliated epithelial cells.

Subtype-specific affinity for corticosterone of rat organic cation transporters rOCT1 and rOCT2 depends on three amino acids within the substrate binding region.

The affinity of corticosterone to organic cation transporters (OCTs) is subtype- and species-dependent. For example, the IC50 values for corticosterone inhibition of cation uptake by transporters rOCT1 and rOCT2 are approximately 150 and approximately 4 microM, respectively. By introducing domains and amino acids from rOCT2 into rOCT1, we found that the exchange of three amino acids in the presumed 10th transmembrane alpha helix is sufficient to increase the affinity of rOCT1 for corticosterone to that of rOCT2.

Different affinities of inhibitors to the outwardly and inwardly directed substrate binding site of organic cation transporter 2.

The rat organic cation transporter 2 (rOCT2) was expressed in Xenopus laevis oocytes and cation-induced outward and inward currents were measured in whole cells and giant patches using voltage clamp techniques. Tetrabutylammonium (TBuA) and corticosterone were identified as nontransported inhibitors that bind to the substrate binding site of rOCT2. They inhibited cation-induced currents from both membrane sides.

A glucose sensor hiding in a family of transporters.

We have examined the expression and function of a previously undescribed human member (SGLT3/SLC5A4) of the sodium/glucose cotransporter gene family (SLC5) that was first identified by the chromosome 22 genome project. The cDNA was cloned and sequenced, confirming that the gene coded for a 659-residue protein with 70% amino acid identity to the human SGLT1. RT-PCR and Western blotting showed that the gene was transcribed and mRNA was translated in human skeletal muscle and small intestine.

The cation transporters rOCT1 and rOCT2 interact with bicarbonate but play only a minor role for amantadine uptake into rat renal proximal tubules.

In renal proximal tubules, the organic cation transporters rOCT1 and rOCT2 are supposed to mediate the first step in organic cation secretion. We investigated whether previously described differences in amantadine and tetraethylammonium (TEA) uptake into isolated renal proximal tubules could be explained by differences in their transport by rOCT1 and rOCT2. By expressing rOCT1 and rOCT2 in Xenopus oocytes and HEK 293 cells, we demonstrated that both transporters translocated amantadine.