ИВЛИНДУЦИРОВАННЫЕ ПОВРЕЖДЕНИЯ ЛЕГКИХ (ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ)

Objective: to evaluate the impact of highfrequency jet ventilation (HFJV) and traditional positive endexpiratory pressure (PEEP) ventilation on blood oxygenation, gas exchange, and hemodynamics on an experimental model of acute lung injury.Material and methods. Thirty albino outbred laboratory male rats weighing 200—300 g were randomly selected for investigations and further divided into groups: 1) traditional ventilation (TV) (n=15); 2) HFJV (n=15). The rats were anesthetized with intraabdominal ketamine (6—8 mg/kg) and sibasone (15—45 mg). Anesthesia was maintained by the bolus administration of ketamine (1 mg/kg every 15—20 min). Tracheostomy was carried outwith a 0.2—0.4 mm diameter endotracheal tube that was then fixed using surgical thread 2—2.5 cm deep to the cricoid cartilage.Results. Acute respiratory distress syndrome (ARDS) has clear histological criteria for lung tissue structural injury; it is widely prevalent in clinical practice and associated with high mortality rates. The paper describes anexperimental ARDS model, the essence of which is 45—55% aspiration of the circulating blood volume for 10—15 minutes. A Reosorbilact® solution was used to compensate for the volume of blood loss, which was followed by the administration of autothromboplastin (16—20 mg/kg animal weight). PEEP was studied for its impact on gasexchange, hemodynamics, and blood oxygenation during HFJV and TV. Gas exchange parameters during TV and HFJV were comparatively analyzed.Conclusion. The use of PEEP for ARDS was ascertained to improve blood oxygenation due to decreased pulmonary shunt, better respiratory muscle performance, lower infiltrated and atelectatic tissue volumes, and higher lung functional residual capacityЦель исследования. Изучить влияние ВЧС ИВЛ и ТИВЛ с ПДКВ на оксигенацию крови, газообмен и гемодинамику на экспериментальной модели острого повреждения легких.Материал и методы. для проведения исследований на животных были отобраны в случайном порядке 30 самцов белых беспородных лабораторных крыс весом 200—300 г, с последующим разделением их на группы. 1 группа — для ТИВЛ (n=15). 2 группа — для ВЧС ИВЛ (n=15). Крысы были наркотизированы внутрибрюшинным введением кетамина (6—8 мг/кг) и сибазона (15—45 мг). Анестезию поддерживали болюсным введением кетамина (1 мг/кг каждые 15—20 мин.). Была произведена трахеостомия для установки эндотрахеальной трубки диаметром 0,2—0,4 мм, которая затем была фиксирована хирургической нитью на глубине 2—2,5 см от перстневидного хряща.Результаты. Острый респираторный дистресссиндром (ОРДС) имеет четкие гистологические критерии повреждения структур ткани легкого, широко распространен в клинической практике и сопровождается высокой летальностью. В статье описана экспериментальная модель ОРДС, сущность которой состоитв аспирации 45—55% от объема циркулирующей крови в течение 10—15 минут. Объем потери крови восполняли раствором Реосорбилакта® с последующим введением аутотромбопластина (16—20 мг/кг веса животного). Проведено исследование влияния положительного давления в конце выдоха (ПДКВ) на газообмен, гемодинамику и оксигенацию крови при высокочастотной струйной вентиляции легких (ВЧС ИВЛ) и традиционной искусственной вентиляции легких (ТИВЛ). Проведен сравнительный анализ параметров газообмена при применении ТИВЛ и ВЧС ИВЛ.Заключение. Выявлено, что применение ПДКВ при ОРДС улучшает оксигенацию крови вследствие уменьшения легочного шунта, облегчения работы дыхательных мышц, уменьшения объемов инфильтрированных и ателектатических тканей, а также повышения функциональной остаточной емкости легких

ДИФФЕРЕНЦИРОВАННАЯ ВЕНТИЛЯЦИЯ ЛЕГКИХ ПРИ ОСТРОЙ ЦЕРЕБРАЛЬНОЙ НЕДОСТАТОЧНОСТИ

Summary. The study was aimed at investigating the intracranial and cerebral perfusion pressures during lung ventilation in 58 patients with brain insult. The study demonstrated that non-invasive ventilation did not affect the intracranial pressure and cardiovascular activity significantly and therefore did not deteriorate the cerebral perfusion pressure. This confirms a benefit of non-invasive lung ventilation and a rationale for its use for respiratory support incorporated in intensive therapy of acute cerebral vascular failure. A role of monitoring gas content and arteriovenous oxygen difference in the venous blood flow from the cranial cavity was also defined during respiratory support in patients with acute cerebral vascular failure.Резюме. Целью исследования было изучение динамики показателей внутричерепного и церебрального перфузионного давления в условиях использования различных способов вентиляции легких у 58 больных острой церебральной недостаточностью. Полученные данные показывают, что вспомогательные режимы вентиляции существенно не влияют на внутричерепное давление и функцию сердечно-сосудистой системы, тем самым не оказывают отрицательного действия на церебральное перфузионное давление. Это доказывает преимущество вспомогательных режимов и целесообразность их использования для проведения респираторной поддержки в практике интенсивной терапии острой церебральной недостаточности. Также определено значение мониторинга показателей газового состава венозной крови, оттекающей из полости черепа и артериовенозной разницы по кислороду при проведении респираторной поддержки у больных с острой церебральной недостаточностью

Search for Kaluza-Klein Graviton Emission in ppˉp\bar{p} Collisions at s=1.8\sqrt{s}=1.8 TeV using the Missing Energy Signature

We report on a search for direct Kaluza-Klein graviton production in a data sample of 84 ${pb}^{-1}$ of \ppb collisions at $\sqrt{s}$ = 1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and one or two high energy jets. We compare the data with the predictions from a $3+1+n$-dimensional Kaluza-Klein scenario in which gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for $n$=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71 TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure

Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Tevatron

We have measured the number of like-sign (LS) and opposite-sign (OS) lepton pairs arising from double semileptonic decays of $b$ and $\bar{b}$-hadrons, pair-produced at the Fermilab Tevatron collider. The data samples were collected with the Collider Detector at Fermilab (CDF) during the 1992-1995 collider run by triggering on the existence of $\mu \mu$ and $e \mu$ candidates in an event. The observed ratio of LS to OS dileptons leads to a measurement of the average time-integrated mixing probability of all produced $b$-flavored hadrons which decay weakly, $\bar{\chi} = 0.152 \pm 0.007$ (stat.) $\pm 0.011$ (syst.), that is significantly larger than the world average $\bar{\chi} = 0.118 \pm 0.005$.Comment: 47 pages, 10 figures, 15 tables Submitted to Phys. Rev.

ATP release via anion channels

ATP serves not only as an energy source for all cell types but as an ‘extracellular messenger-for autocrine and paracrine signalling. It is released from the cell via several different purinergic signal efflux pathways. ATP and its Mg2+ and/or H+ salts exist in anionic forms at physiological pH and may exit cells via some anion channel if the pore physically permits this. In this review we survey experimental data providing evidence for and against the release of ATP through anion channels. CFTR has long been considered a probable pathway for ATP release in airway epithelium and other types of cells expressing this protein, although non-CFTR ATP currents have also been observed. Volume-sensitive outwardly rectifying (VSOR) chloride channels are found in virtually all cell types and can physically accommodate or even permeate ATP4- in certain experimental conditions. However, pharmacological studies are controversial and argue against the actual involvement of the VSOR channel in significant release of ATP. A large-conductance anion channel whose open probability exhibits a bell-shaped voltage dependence is also ubiquitously expressed and represents a putative pathway for ATP release. This channel, called a maxi-anion channel, has a wide nanoscopic pore suitable for nucleotide transport and possesses an ATP-binding site in the middle of the pore lumen to facilitate the passage of the nucleotide. The maxi-anion channel conducts ATP and displays a pharmacological profile similar to that of ATP release in response to osmotic, ischemic, hypoxic and salt stresses. The relation of some other channels and transporters to the regulated release of ATP is also discussed

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Search for doubly charged Higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in p(p)over-bar collisions at root s=1.96 TeV

A search for pair production of doubly charged Higgs bosons in the process p (p) over bar -->H++H---->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of roots=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H-L(+/-+/-))>118.4 GeV/c(2) and M(H-R(+/-+/-))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs

Analysis of common errors and methods of calibration of ultrasonic level meter

This article is devoted to improve the accuracy of the measuring system to the analyzing of common errors of an ultrasonic level meter designed to measure the level of liquid materials in tanks. To reduce the random error of the measurement system, appropriate measures and compensation methods are presented. As a result, it was revealed that the generalized cumulative error of the device belongs to the interval G = 1.3 - 2%