[Unformed conglomerate debilitating jejunal fistulas and their two-stage surgical treatment via posterolateral laparotomy]. / Nesformirovannye konglomeratnye istoshchayushchie toshchekishechnye svishchi i ikh dvukhetapnoe khirurgicheskoe lechenie iz zadnebokovogo laparotomnogo dostupa.

OBJECTIVE: To create a method of two-stage repair of high unformed conglomerate delimited debilitating jejunal fistulas via posterolateral laparotomy with low risk of surgical complications. MATERIAL AND METHODS: Methodology and treatment outcomes were analyzed in 37 patients with unformed conglomerate high debilitating delimited jejunal fistulas. Of these, 22 patients underwent one-stage treatment through 2 converging incisions and/or two-stage treatment through anterolateral access. They made up a control group. Fifteen patients in the main group underwent two-stage treatment via posterolateral left-sided laparotomy with unilateral disconnection of jejunum with fistula. In most patients of both groups, fistulas complicated surgery for acute adhesive intestinal obstruction. Topography of adhesions that caused acute intestinal obstruction in both groups was studied in 172 other patients. Identical jejunal fistulas and two different surgical approaches made it possible to consider our groups representative. RESULTS: Two-stage treatment via posterolateral left-sided laparotomy reduced mortality from 63.6±10.2% to 20.0±10.3% (t=11.8; p<0.001). This approach simplified intraoperative diagnostics that became more informative. Posterolateral access increased the quality of anastomosis and safety of viscerolysis. CONCLUSION: A new two-stage approach with posterolateral left-sided laparotomy allowed atraumatic imposing of inter-intestinal anastomosis with proximal disconnection of jejunal fistula. This exclusion turns the fistula into analogue of the definitive Meidl's jejunostomy, unloads the intestinal anastomosis and increases the quality of suture. New strategy reduced the risk of complications and mortality.

[Mobilization of splenic flexure - routine or selective (results of a single-center randomized study)]. / Mobilizatsiya selezenochnogo izgiba obodochnoi kishki­ rutinno ili selektivno.

OBJECTIVE: To evaluate safety and effectiveness of routine splenic flexure mobilization (SFM) in surgical treatment of rectal cancer (RC). MATERIAL AND METHODS: A single-center randomized study was performed between 2016 and 2019. Patients were randomized into 2 groups (SFM (+), n=156, SFM(-), n=67). Standard anterior and low anterior rectal resection was used. We used a combination of medial, lateral, and anterior approaches for SFM. Intraoperative, early and late postoperative complications, histological data, local recurrence, overall 3-year, relapse-free and cancer-specific survival were analyzed. RESULTS: Surgery time was 253.2±72.8 and 252.0±78.0 min in the SFM(+) and SFM(-) groups, respectively (p=0.98). Blood loss was 53.3±53.6 and 67.0±108.8 ml, respectively (p=0.85), length of specimen - 28.6 (95% CI 27.2-29.9) and 24.0 cm (95% CI 22.2-25.7) (p<0.0001). Length of residual fragment of sigmoid colon was 5.0 (95% CI 3.9-6.1) and 9.1 cm (95% CI 7.2-11.1) (p<0.0001), respectively. The number of examined lymph nodes was 15.5 (95% CI 14.2-16.8) and 16.1 (95% CI 14.2-18.1) (p=0.52), number of affected lymph nodes - 1.5 (95% CI 0.9-2.1) and 1.5 (95% CI 0.9-2.2), respectively (p=0.38). Spleen damage was more common in the SFM (-) group (4.5% vs. 1.3%, p=0.12). Logistic regression analysis indicates that SFM does not affect the incidence of spleen damage. Severity of postoperative complications was similar (p=0.63). Anastomotic leak (AL) was more common in the SFM group (-) (17.9% vs. 9.6%, p=0.04). AL grade B was more common in the SFM(-) group (p=0.0001). Logistic regression analysis revealed the following predictors of anastomotic leakage: length of specimen and length of residual sigmoid colon. There was no significant relationship between SFM and incidence of local and systemic recurrences. Overall, cancer-specific and relapse-free 3-year survival was similar. CONCLUSION: SFM is a safe procedure with various advantages. However, this approach does not improve intraoperative, early and long-term postoperative outcomes that does not allow us to recommend this approach for routine application.

[Results of reconstructive surgery with formation of low colorectal anastomoses after previous Hartmann's procedure]. / Rezul'taty rekonstruktivno-vosstanovitel'nykh operatsii s formirovaniem nizkikh kolorektal'nykh anastomozov posle obstruktivnykh rezektsii pryamoi kishki.

OBJECTIVE: To evaluate the efficacy and safety of original access to short rectal stump compared to traditional direct one. MATERIAL AND METHODS: A retrospective-prospective cohort comparative study was conducted between 2012 and 2018. Inclusion criterion was previous Hartmann's procedure with formation of a short rectal stump. Short stump was determined by its length from anal-skin line to the cupola <7 cm. There were 93 patients who were divided into 2 groups: the main group - new approach (n=38), the control group - traditional direct approach (n=55). We analyzed surgery time, blood loss, intraoperative, early and late postoperative morbidity. RESULTS: Surgery time and blood loss were similar in both groups (299.9 vs. 288.3 min, p=0.82; 204.5 vs. 112.4 ml, p=0.94, respectively). Intraoperative complications occurred in 7 patients of the control group (0 vs. 12.7% (7/55), p=0.02). Incidence of early postoperative complications was similar (28.9% (11/38) vs. 25.5% (14/55), p=0.71). Adverse events Clavien-Dindo grade I and IIIa were more common in the main group, grade IIIb and IVa - in the control group. Incidence of delayed postoperative complications were similar (10.5% (4/38) vs. 7.3% (4/55), p=0.58). Colorectal anastomosis stricture prevailed in the control group, ureteral stricture - in the main group. Neurophysiological and complex urodynamic examinations revealed no between-group differences. CONCLUSION: The new method ensures access to the rectal stump and formation of colorectal anastomosis under direct visual control. Postoperative outcomes demonstrated safety and effectiveness of this technique.

[Splenic flexure mobilization in surgery for rectal cancer]. / Mobilizatsiia selezenochnogo izgiba pri rezektsii priamoi kishki po povodu raka: tak li éto neobkhodimo?

Nowadays, the issue of splenic flexure mobilization (SFM) in anterior and low anterior rectal resection for rectal cancer is still debatable. This stage is important because dissection results tension-free anastomosis and excision of specimen of enough length with adequate number of harvested lymph nodes. However, literature review confirmed the absence of agreement regarding reduced incidence of colorectal anastomotic leakage and improved long-term oncologic outcomes after SFM. Opinion about selective approach to this procedure is becoming more common. Therefore, randomized trials are necessary to determine a need for routine SFM or indications for selective approach to SFM in anterior rectal resection for rectal cancer.

Unusual features of the c-ring of F1FO ATP synthases.

Membrane integral ATP synthases produce adenosine triphosphate, the universal "energy currency" of most organisms. However, important details of proton driven energy conversion are still unknown. We present the first high-resolution structure (2.3 Å) of the in meso crystallized c-ring of 14 subunits from spinach chloroplasts. The structure reveals molecular mechanisms of intersubunit contacts in the c14-ring, and it shows additional electron densities inside the c-ring which form circles parallel to the membrane plane. Similar densities were found in all known high-resolution structures of c-rings of F1FO ATP synthases from archaea and bacteria to eukaryotes. The densities might originate from isoprenoid quinones (such as coenzyme Q in mitochondria and plastoquinone in chloroplasts) that is consistent with differential UV-Vis spectroscopy of the c-ring samples, unusually large distance between polar/apolar interfaces inside the c-ring and universality among different species. Although additional experiments are required to verify this hypothesis, coenzyme Q and its analogues known as electron carriers of bioenergetic chains may be universal cofactors of ATP synthases, stabilizing c-ring and prevent ion leakage through it.

New Insights on Signal Propagation by Sensory Rhodopsin II/Transducer Complex.

The complex of two membrane proteins, sensory rhodopsin II (NpSRII) with its cognate transducer (NpHtrII), mediates negative phototaxis in halobacteria N. pharaonis. Upon light activation NpSRII triggers a signal transduction chain homologous to the two-component system in eubacterial chemotaxis. Here we report on crystal structures of the ground and active M-state of the complex in the space group I212121. We demonstrate that the relative orientation of symmetrical parts of the dimer is parallel ("U"-shaped) contrary to the gusset-like ("V"-shaped) form of the previously reported structures of the NpSRII/NpHtrII complex in the space group P21212, although the structures of the monomers taken individually are nearly the same. Computer modeling of the HAMP domain in the obtained "V"- and "U"-shaped structures revealed that only the "U"-shaped conformation allows for tight interactions of the receptor with the HAMP domain. This is in line with existing data and supports biological relevance of the "U" shape in the ground state. We suggest that the "V"-shaped structure may correspond to the active state of the complex and transition from the "U" to the "V"-shape of the receptor-transducer complex can be involved in signal transduction from the receptor to the signaling domain of NpHtrII.

High-resolution structure of a membrane protein transferred from amphipol to a lipidic mesophase.

Amphipols (APols) have become important tools for the stabilization, folding, and in vitro structural and functional studies of membrane proteins (MPs). Direct crystallization of MPs solubilized in APols would be of high importance for structural biology. However, despite considerable efforts, it is still not clear whether MP/APol complexes can form well-ordered crystals suitable for X-ray crystallography. In the present work, we show that an APol-trapped MP can be crystallized in meso. Bacteriorhodopsin (BR) trapped by APol A8-35 was mixed with a lipidic mesophase, and crystallization was induced by adding a precipitant. The crystals diffract beyond 2 Å. The structure of BR was solved to 2 Å and found to be indistinguishable from previous structures obtained after transfer from detergent solutions. We suggest the proposed protocol of in meso crystallization to be generally applicable to APol-trapped MPs.

Nanoparticle surface-enhanced Raman scattering of bacteriorhodopsin stabilized by amphipol A8-35.

Surface-enhanced Raman spectroscopy (SERS) has developed dramatically since its discovery in the 1970s, because of its power as an analytical tool for selective sensing of molecules adsorbed onto noble metal nanoparticles (NPs) and nanostructures, including at the single-molecule (SM) level. Despite the high importance of membrane proteins (MPs), SERS application to MPs has not really been studied, due to the great handling difficulties resulting from the amphiphilic nature of MPs. The ability of amphipols (APols) to trap MPs and keep them soluble, stable, and functional opens up onto highly interesting applications for SERS studies, possibly at the SM level. This seems to be feasible since single APol-trapped MPs can fit into gaps between noble metal NPs, or in other gap-containing SERS substrates, whereby the enhancement of Raman scattering signal may be sufficient for SM sensitivity. The goal of the present study is to give a proof of concept of SERS with APol-stabilized MPs, using bacteriorhodopsin (BR) as a model. BR trapped by APol A8-35 remains functional even after partial drying at a low humidity. A dried mixture of silver Lee-Meisel colloid NPs and BR/A8-35 complexes give rise to SERS with an average enhancement factor in excess of 10(2). SERS spectra resemble non-SERS spectra of a dried sample of BR/APol complexes.

[Early complications after surgery for middle- and lower-ampullar cancer: total mesorectumectomy or "blind" preparation of rectum?].

It was performed a comparative analysis of parameters of early postoperative period in 318 patients with middle- and lower-ampullar cancer of rectum who underwent total mesorectumectomy and "blind" preparation of rectum. All patients were divided into 2 groups. The main group included 202 patients after total mesorectumectomy. The control group included 116 patients after "blind" preparation of rectum. Statistically significant differences in frequency of laparotomy wounds suppuration, urinary tract dysfunction and postoperative mortality were revealed. These complications were diagnosed more frequent in case of "blind" preparation of rectum. In the main group laparotomy wounds suppuration depended on sex (p<0.001, r=0.65), in the control group - on surgeon's experience (p=0.006, r=0.58), localization of tumor (p<0.001, r= -0.87) and type of surgery (p<0.001, r= -0.76). Urinary tract dysfunction after total mesorectumectomy depended on patient's sex (p<0.001, r=-0.77), after "blind" preparation of rectum - sex (p=0.002, r= -0.39) and performing of preoperative radiation therapy (p<0.001, r=0.46). In the main group none of the analyzed variables effected on the postoperative mortality. In the control group age (p=0.006, r=0.48), intraoperative blood loss (p=0.002, r=0.55), anastomosis failure (p=0.01, r=0.61), postoperative bleeding (p<0.001, r=0.88), early adhesive intestinal obstruction (p=0.006, r=0.77) effected on the mortality. It is considered that total mesorectumectomy in comparison with "blind" preparation of rectum decreases frequency of postoperative complications and mortality.

[Application of prolonged flow-aspiration drainage of laparotomy wounds in order to reduce suppurative septic complications in bowels reconstructive surgery].

The article presents the follow-up study of 254 onco-proctologic patients after reconstructive abdominoperitoneal resections. Patients were divided into 4 statistically homogeneous groups (2 main and 2 control groups). A comparative analysis of middle and lateral laparotomy wounds healing was made. Laparotomy wounds were stitched up using conventional method (in layers, tightly) and using other method of prolonged flow-aspiration drainage of hypodermic tissue. Postoperative wound infections were noted in 11.4% patients in case of conventional means. The prolonged flow-aspiration drainage in laparotomy wounds causes only 1.5% of complications.

[A method for reducing suppurative septic complications in the perineal wound after cylindrical extralevatory extirpation of the rectum in cancer patients].

One of frequent postoperative complications of cylindrical extralevatory extirpation of the rectum is suppuration of a perineal wound. It is possible to reduce to a minimum or to prevent completely this complication by application of the passive prolonged drainage of a perineal wound.

[Influence of irrigation prolonged drainage on healing laparotomy wounds in patients with colorectal cancer].

In two statistically uniform groups of observation of oncocoloproctological patients a comparative analysis was made of healing median laparotomy wounds sutured traditionally (layerwise, hermetically) and with irrigating prolonged drainage of the subcutaneous fat. Traditional suturing of the wounds was followed by suppuration in 66%, while in laparotomy wounds where irrigating prolonged drainage was used there were no cases of suppuration.

Few-cycle attosecond pulses via periodic resonance interaction with hydrogenlike atoms.

We show that it is possible to produce nearly bandwidth-limited few-cycle attosecond pulses based on periodic resonance interaction of a quasi-monochromatic radiation with the bound states of hydrogenlike atoms. A periodic resonance is provided by a far-off-resonant laser field with intensity much below the atomic ionization threshold via periodic tunnel ionization from the excited states and adiabatic Stark splitting of the excited energy levels. Without external synchronization of the spectral components, it is possible to produce 135 as pulses at 13.5 nm in Li²âº-plasma controlled by radiation of a mode-locked Nd:YAG laser, as well as 1.25 fs pulses at 122 nm in atomic hydrogen controlled by radiation of a CO2 laser.

Extremely short pulses via stark modulation of the atomic transition frequencies.

We propose a universal method to produce extremely short pulses of electromagnetic radiation in various spectral ranges. The essence of the method is a resonant interaction of radiation with atoms under the conditions of adiabatic periodic modulation of atomic transition frequencies by a far-off-resonant control laser field via dynamic Stark shift of the atomic levels and proper adjustment of the control field intensity and frequency, as well as the optical depth of the medium. The potential of the method is illustrated by an example in a hydrogenlike atomic system.