RESUMEN

OBJECTIVES: A carrier prototype by Aerocom® (Schwäbisch Gmünd, Germany) for pneumatic tube systems (PTS) is able to transport 9 blood tubes which are automatically fixed by closing the lid. In this study, we examined the influence of the transport on blood sample quality using the carrier prototype comparing to courier transport and a conventional carrier (AD160, Aerocom®). METHODS: Triplicate blood samples sets (1 lithium heparin, 1 EDTA, 1 sodium citrate) of 35 probands were split among the transportation methods: 1. courier, 2. conventional carrier, and 3. carrier prototype. After transport 51 measurands from clinical chemistry, hematology and coagulation were measured and compared. RESULTS: Overall, 49 of the investigated 51 measurands showed a good concordance among the three transport types, especially between the conventional carrier and the carrier prototype. Focusing on well-known hemolysis sensitive measurands, potassium showed no statistically significant differences. However, between courier and both carrier types lactate dehydrogenase (LDH) and free hemoglobin (fHb) showed statistically significant shifts, whereas the clinical impact of the identified differences was neglectable. The median concentration of fHb, for example, was 0.29 g/L (18 µmol/L), 0.31 g/L (19 µmol/L) and 0.32 g/L (20 µmol/L) for courier transport, conventional carrier and carrier prototype, respectively. These differences cannot be resolved analytically since the minimal difference (MD) for fHb is 0.052 g/L (3.23 µmol/L), at this concentration. CONCLUSIONS: The carrier prototype by Aerocom® is suitable for transportation of diagnostic blood samples. The overall workflow is improved by decreasing hands-on-time on the ward and laboratory while minimizing the risk of incorrectly packed carriers.

Asunto(s)

RESUMEN

Signal fluctuations in a fluorescence time trace on nanosecond time scales can be induced by specific quenching interactions that report on the dynamics of biomolecules. Fluorescence correlation spectroscopy is an analysis tool to investigate dynamic processes on time scales from pico- to milliseconds or longer. Under certain conditions, e.g. in a solvent of high viscosity, a fluorescence labeled dynamic biomolecule yields multiple independent correlation decays due to rotational and translational diffusion, fluorescence quenching interactions, and fluorophore photophysics. We compared parameter estimation for FCS data with multiple correlation decays by dynamical fingerprint analysis and by the non-linear Levenberg-Marquardt fitting procedure and identified conditions for which dynamical fingerprint analysis can be of advantage. In this context we identified a previously unrecognized photophysical process in ATTO655 that introduces fluorescence intermittency on nanosecond time scales that is absent in MR121. The optimized fitting procedure is used to resolve the viscosity dependence of fluorescence quenching for photoinduced electron transfer probes.

Asunto(s)

RESUMEN

BACKGROUND: Incorporation of advanced laparoscopic procedures in the practice of institutions without respective experience is a significant impediment in the dissemination of minimally invasive techniques. On-site mentoring programs carry several cost-related and practical constraints. Telementoring has emerged as a practical and cost-effective alternative mentoring tool. The present study aimed to review the pertinent literature on telementoring applications in laparoscopic general surgery. METHODS: A systematic review using the Medline database was performed. Articles reporting on clinical experience with telementoring applications in general surgery were included. Variations in methodology, study design, and operative procedures precluded cumulative outcome evaluation. Instead, a critical appraisal of current evidence was undertaken. RESULTS: Seventy-five articles were identified in the primary search, and ten studies were considered eligible. No randomized studies comparing on-site mentoring with telementoring were identified. The included studies reported on a total of 96 laparoscopic telementored procedures: 50 cholecystectomies, 23 colorectal resections, 7 fundoplications, 9 adrenalectomies, 6 hernia repairs, and 2 splenectomies. Completion of remotely assisted procedures was feasible in the vast majority of cases, whereas technical difficulties included video and audio latency with low transfer rates (<128 kbps) and inadequate guidance regarding the correct plane for dissection. CONCLUSION: Current evidence supports the feasibility and safety of telementoring programs in general surgery. Their clinical effectiveness as teaching alternatives to traditional mentoring programs remains to be further evaluated.

Asunto(s)

Asunto(s)

RESUMEN

Stacking interactions between organic fluorophores can cause formation of non-fluorescent H-dimers. Dimer formation and dissociation of two fluorophores site-specifically incorporated in a biomolecule result in fluorescence intermittency that can report on conformational dynamics. We characterize intramolecular dimerization of two oxazine fluorophores MR121 attached to an unstructured polypeptide. Formation of stable non-fluorescent complexes with nano- to microsecond lifetimes is a prerequisite for analysing the intermittent fluorescence emission by fluorescence correlation spectroscopy and extracting relaxation time constants on nano- to millisecond time scales. Destabilization of the generally very stable homodimers by chemical denaturation reduces the lifetime of H-dimers. We demonstrate that H-dimer formation of an oxazine fluorophore reports on end-to-end contact rates in unstructured glycine-serine polypeptides under denaturing conditions.

Asunto(s)

RESUMEN

As safe techniques and adequate equipment are easily accessible, the minimally invasive approach to cholecystectomy has become the gold standard over the last decade. Nowadays, further minimally invasive techniques using only 1 skin incision to gain access to the abdominal cavity have become available. Transvaginal, transcolonic, or transgastric approaches have recently been described. We present a laparoscopic single-incision transumbilical approach to cholecystectomy with commonly used laparoscopic instruments.

Asunto(s)

RESUMEN

Reversal of Hartmann's procedure is associated with a high morbidity and mortality leading to a low rate of intestinal restoration. We investigated whether the laparoscopic reversal is safely feasible and offers any advantage to the patient. The reversal operation was performed in 28 of 34 patients after Hartmann's procedure. The laparoscopic reversal of Hartmann's procedure had a short operative time (69 min) and a conversion rate of 17.9%. Wound complications occurred in 10.7%, an anastomosic leak in 1 patient (3.6%). On average the patients were discharged after 8.6 (6 to 17) postoperative days. We conclude that the laparoscopic reversal of Hartmann's procedure is a technically demanding but feasible operation with a low postoperative morbidity and mortality. We recommend the laparoscopic approach, which could be favorable compared with historical open series.

Asunto(s)