Performance of a cryo-cooled crystal monochromator illuminated by hard X-rays with MHz repetition rate at the European X-ray Free-Electron Laser.

Due to the high intensity and MHz repetition rate of photon pulses generated by the European X-ray Free-Electron Laser, the heat load on silicon crystal monochromators can become large and prevent ideal transmission in Bragg diffraction geometry due to crystal deformation. Here, we present experimental data illustrating how heat load affects the performance of a cryogenically cooled monochromator under such conditions. The measurements are in good agreement with a depth-uniform model of X-ray dynamical diffraction taking beam absorption and heat deformation of the crystals into account.

Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser Facility.

The Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser (EuXFEL) facility is described. EuXFEL is the first hard X-ray free-electron laser operating in the MHz repetition range which provides novel science opportunities. The aim of MID is to enable studies of nano-structured materials, liquids, and soft- and hard-condensed matter using the bright X-ray beams generated by EuXFEL. Particular emphasis is on studies of structure and dynamics in materials by coherent scattering and imaging using hard X-rays. Commission of MID started at the end of 2018 and first experiments were performed in 2019.

[Blood supply as a factor regulating pacemaker activity of the rat uterine horn].

Effect of ischemia of the uterine artery supplying with blood the main rhythmogenic zone (the ovarian region) of the uterine horn on parameters of activity both of this locus and of all subsequent pacemaker areas up to the uterine cervix was studied in non-pregnant rats. The most pronounced changes in characteristics of the activity (amplitude, frequency, and burst genesis duration) were revealed in the ovarian horn end. The uterine corpus and the horn cervical end were less affected by ischemia. Meanwhile, under these conditions, amplitude of the slow-wave oscillations rose more than 1.5 times. The obtained data allow us to conclude about the presence of a certain connection between the horn ovarian end and the uterine cervix. Morphological studies have revealed strong vascularization of the upper part of uterine horn.

[Role of acetylcholine in coordination od spontaneous electrical activity of various areas of the rat uterus].

Spontaneous electrical activity of myometrium was studied in areas of the uterine corpus, zone of its connection with uterine tube and cervix at intravenous administration of various acetylcholine concentrations. Under these conditions, changes of the frequency and amplitude characteristics of rhythmogenesis were studied both separately and in their combined active state. The presence of 10(-3) M acetylcholine in the animal blood creates the most optimal conditions for synchronization and coordination of activities of all studied uterus areas.

[Role of oxytocin in activation of spontaneous electrical activity of uterine body and uterine tubes in non-pregnant rats].

The work studies effects of various doses of oxytocin (0.01, 0.1, 1 and 10 microg/kg) on duration of discharges of spontaneous electrical activity and frequency of spikes in various parts of uterine tubes and of uterine body of non-pregnant rats. Under these conditions, changes in these parameters for ovarian parts of the uterine tubes had similar character unlike those in cervical parts of the tubes and in the middle part of the uterine body, so the latter parts can be grouped together owing to peculiarities of their changes. The longest duration of genesis of electric discharges has been shown for the ovarian part of uterine tubes at a concentration of 10 microg/kg of oxytocin. Morphological experiments revealed that among all studies areas the ovarian parts of uterine tubes were characterized by the highest amount of atypical cells that have the maximally pronounced functional activity.

[Effect of oxytocin on activation of spontaneous electrical activities registered from uterine corpus and uterine tubes in rats].

The effects if different concentrations of oxytocin (10(-2), 10(-1), 1 and 10 microg/kg) on burst duration and spikes frequency of spontaneous electrical activity in various parts of uterine horns and uterine corpus in non-pregnant rats have been shown. The changes in given parameters for ovarian parts of horns had similar characters unlike cervical parts of horns and middle part of uterine corpus under these conditions, so the last mentioned areas could be grouped together by the reason of similar changes in their parameters. Oxytocin in a concentration of 10(-1) microg/kg promoted the longest duration of spike electrical activity genesis in ovarian parts of horns. Morphological experiments showed that ovarian parts of horns had a great amount of atypical cells with strongly expressed functional activities.

[Effect of nifedipine on electrophysiological properties of rat ureter spontaneous activity].

The work studied effect of various concentrations of nifedipine on the slow and fast spontaneous activities evoked in the perivesical and perirenal areas of the rat ureter. Whereas in the proximal zone of the organ at the low dose of nifedipine (0.06 and 0.12 mg/kg), inhibition is revealed both of slow waves and of their corresponding spikes, in the perivesical part the opposite effect is observed. Besides, with further increase of the nifedipine dose to 0.15 and 0.2 mg/kg, in the ureter area adjacent to the urinary bladder, alongside with acceleration of slow pacemaker oscillations, the appearance of the antiperistaltically directed action potentials is also possible.

[Autonomy of spontaneous rhythmogenesis of perivesicular area of cat ureter].

The work present data indicating no dependence of the pacemaker activity located in the zone of junction of cat ureter with urinary bladder on genesis of the main perirenal pacemaker. Data are presented on effect of clamping the renal artery supplying with blood flow the renal area on rhythmogenesis of the ureter perivesicular area. An inhibition of the pacemaker activity of the pyeloureteral anasomosis is observed. At the same time, no marked effect on automatism of the low organ area is revealed. Data of morphological studies of the vascular bed providing blood supply of various ureter areas are presented.

[Study of volatile fatty acids in the blood of patients with periodic disease].

Microecological "failures" are an important pathogenetic factor of different diseases and, in the authors' opinion, periodic disease (PD) is one of them. PD is a recessive disease characterized by fever attacks and neutrophil-mediated serous inflammation. A genetic factor has been established to be responsible for half the cases of PD, the influence of non-hereditary factors, particularly a role of the host automicroflora in the genesis of an inflammatory process, has been little studied. The authors' early studies indicate that there are changes in the qualitative and quantitative composition of microbial molecules in the blood of patients with PD. The anaerobic bacterial metabolites that are volatile fatty acids (VFAs) represent biologically active substances that affect the growth of the microflora, on the one hand, and the host's immunological responsiveness, on the other. Out of VFAs, only is acetic acid detectable in small quantities in the blood of healthy individuals. The other VFAs, namely propionic, valeric, butyric, and caproic acids and their isomers, are absent. Gas chromatography was used for qualiitative and quantitative determination of the metabolites of anaerobic microorganisms in the blood of patients with PD (n = 13) during an attack and remission and in that of healthy volunteers (Armenians) (n = 5) of a control group from one Yerevan region. The blood samples from all the patients with PD displayed a significantly higher concentration of caproic acid while the latter was absent in the blood of the controls. This finding suggests that there is a specific shift in the structure of the microbiocenosis in patients with PD. It is conceivable that caproic acid plays a certain role in the pathogenesis of the disease under study. Further studies will deal with the association of some microbial molecules with the manifestation of an attack of PD, which may provide the key to the goal-oriented regulation of detected homeostatic disorders and to the management of the frequency of its attacks.

Porcine peritoneal sepsis: modeling for clinical relevance.

The characteristics of two types of intraperitoneal (i.p.) soilage sepsis models, autologous fecal inoculum (FEC) and a pure culture of Escherichia coli (EC), were studied in 26 male Yucatan minipigs (20-30 kg). Early (1-4 h) and late (24-72 h) changes were different between the two groups. The EC group was characterized early by hypotension, low cardiac output, and increased systemic and pulmonary vascular resistances, along with leukopenia, hypoglycemia, lactacidemia, and elevated blood urea nitrogen. Of the pigs in the EC group that survived the early effects, there were few significant differences in physiological parameters, compared to control pigs, that would indicate ongoing pathological processes. In contrast, the FEC group pigs demonstrated early hypotension, but with increased cardiac output and reduced systemic vascular resistance. Other parameter changes were similar to those seen in the EC pigs, but to a lesser degree, with the exception of elevations in serum lactate dehydrogenase. Also in contrast to the EC group, most of the changes in the FEC group persisted in later days, and FEC pigs demonstrated leukocytosis. There were also greater elevations in circulating lipopolysaccharide (LPS) concentrations in the EC group that returned later to baseline levels. In the FEC group, there were persistently elevated LPS concentrations over 72 h. These observations suggest that pigs challenged with intraperitoneal E. coli demonstrated an initial acute peritonitis and damaging physiologic effects of high levels of circulating LPS. Survivors in this group improved and were physiologically stable after 24 h. Pigs that received i.p. autologous feces developed an early acute peritonitis phase with lower levels of circulating LPS, and later developed pronounced peritoneal reaction as demonstrated by multiple abdominal abscesses, pyogenic granuloma formation, and adhesions with physiological evidence of developing sepsis over 72 h. These observations indicate that i.p. EC models evoke a systemic response not unlike intravenous administration of LPS or EC, however, the FEC model produced a systemic response akin to a slower developing septic process.

Prediction of operative cholangiography in patients undergoing elective cholecystectomy with routine liver function chemistries.

A retrospective reviews of 195 consecutive patients who underwent elective cholecystectomy and operative cystic duct cholangiography (OCDC) were reviewed to establish criteria to correlate the preoperative laboratory data of liver chemistry tests and the actual biliary tract disease found in each patients. Patients who had a history of jaundice or other clinical indication for common bile duct exploration were excluded from this study. The patients were divided into four groups based on the results of the OCDC: I negative, II false positive, III false negative, and IV positive for choledocholithiasis. The results of the preoperative liver chemistry studies of the patients in each of the four groups were analyzed by the chi 2 method. The four liver chemistry tests were lactate dehydrogenase, SGOT, bilirubin, and alkaline phosphatase. When results of all preoperative liver chemistry tests were normal, there was no incidence of choledocholithiasis. As the number of chemistry test result elevations increased from one to four, the incidence of choledocholithiasis increased from 17% to 50% (p less than 0.001). Preoperative liver chemistry tests in selected patients undergoing elective cholecystectomy may provide a valuable indicator to the surgeon as to whether an OCDC should be performed at the time of surgery.

Metallic foreign bodies in the stomach.

We present a case of a patient who ingested 648 metallic objects that formed an intertwining mass within the stomach, requiring operative removal. Of interest was the absence of symptoms and complications after 11 years of continual ingestion. To our knowledge, this is the second heaviest accumulation of metallic foreign objects removed from the stomach of a living patient.

Penetration of clindamycin into the human appendix.

Clindamycin penetrated extremely well into inflamed (19) and normal (one) appendices. Average levels in appendiceal tissue taken 26 to 300 minutes after a single intravenous dose were 154% of the simultaneous serum concentration.

A shunt equation for estimating the splenic component of portal hypertension.

A modification of the Berggren pulmonary shunt equation was derived for use in estimating the splenic component of portal hypertension. It was used in nine patients, six of whom had sufficient decreases in portal flow and pressure after splenic artery and coronary vein ligation. The average decrease in portal flow was 52%.

Radionuclide cholescintigraphy in patients with suspected biliary tract obstruction.

Radionuclide cholescintigraphy is used to help establish the diagnosis of acute cholecystitis and is thought to provide additional information regarding the patency of the biliary duct system. Nonvisualization of the extrahepatic biliary duct system and lack of excretion into the duodenum despite uptake in the liver (a positive study) is considered indicative of common bile duct obstruction. The authors retrospectively reviewed 281 hepatobiliary cholescintigrams done at Stamford Hospital from July 1, 1987 to June 30, 1989. Previous authors have demonstrated a false-positive rate of eight to 15 per cent in those cases that have a documented normal extrahepatic biliary system at operation. Of those patients explored after a common bile duct obstruction pattern depicted by cholescintigram in the authors' series, 46 per cent of patients were found to have normal extrahepatic biliary systems. Factors possibly contributing to this high false-positive rate are discussed. The utility of radionuclide hepatobiliary scans may be limited for diagnosis of biliary duct obstruction.

Gastrointestinal injuries.

Any wound that penetrates the abdomen may involve the gastrointestinal tract whether controlled for a specific operation of diagnostic procedure or uncontrolled when secondary to blunt or penetrating trauma. The first important consideration is the prevention of complications. The choice of incisions, the managment of the contaminated peritoneal cavity, intestinal fistulas and specific bowel injuries and the importan differences in the treatment of injuries to small intestine versus to large intestine and rectum be considered. Bowel viability must also be determined.

Na(+)-Ca++ exchange mechanism in smooth muscle of the ureter.

The participation of Na+ in regulation of intracellular Ca++ content and in formation of spontaneous action potentials of guinea-pig ureter was studied. It was shown that the fast decrease of intracellular Ca++ in the Ca(++)-loaded muscles was accompanied by enhancement of Na+ content in the cells. The concentration gradient of Na+ was found to define the effectiveness of Ca(++)-extrusion from Ca(++)-loaded cells. The decrease of intracellular Ca++ showed a sigmoidal dependence on Na+ content in the medium. A correlation was established between the concentration gradient of Na+ and the formation of action potential plateau of ureter smooth muscle cells. The duration of action potential plateau decreased in accordance with Ca++ efflux and Na+ influx. The results confirmed the participation of Na(+)-Ca++ exchange mechanism in support of Ca++ cellular homeostasis as well as in the generation of action potentials of guinea-pig ureter.

Factors controlling the intracellular concentration of calcium and the spontaneous activity of the ureter.

The role of the electrogenic Na(+)-Ca(2+)-exchange mechanism in regulating the spike activity of the ureter was studied. The ureter cells were shown to be capable of generating action potentials (AP) in sodium-free Krebs solution. The time during which the spikes are generated is in exponential dependence on the concentration of calcium ions in the medium, [Ca2+]o within 2.5 to 15 mmol/l. Simultaneously with the generation of the spikes, accumulation of calcium in the muscles is observed, proportional to the increase of [Ca2+]o. The addition of as little as 20 mmol/l Na+ or Li+ ions into the solution restores the prolonged electrical activity of the ureter. Under these conditions, the decrease of intracellular Ca2+ within 5 min was more than two times larger as compared with that in sodium-free medium. Upon substituting Ba2+ ions for Ca2+ ions in Krebs solution AP are generated within an interval which was the longer the higher the Ba2+ concentration in the medium. Li+ ions can replace Na+ ions in maintaining AP and in extruding calcium from the cell. It is supposed that the generation of the stable spike activity of the ureter depends on the functioning of Na(+)-Ca(2+)-exchange mechanism.

The surgical significance of Persian Gulf sand.

Foreign bodies, in particular sand and soil particles, can cause considerable reaction in wounds and remain in tissues indefinitely. The introduction of foreign material as a contaminant in wounds and intracavitary injuries to military personnel deployed in the Persian Gulf region can be a complicating factor in treatment. Samples of desert sand from the military operational areas of the Persian Gulf were analyzed and the acute local and systemic responses of intraperitoneal contamination determined in an experimental rat model.

[The role of Na+/Ca2+ exchange in the generation of delayed electrical activity of smooth muscle cells]. / Rol' Na+/Ca2+-obmena v generatsii medlennoi élektricheskoi aktivnosti gladkomyshechnykh kletok.

It was shown that electrogenic 3Na+/Ca2+ antiport evoked depolarization of the membranes and Ca2+ ions influx through Ca2+ activated channels which lead to the appearance of stable self-oscillation of the membrane potential (MP), as well as Na+ and Ca2+ ions intracellular concentrations.