Blood feeding of Ornithodoros turicata larvae using an artificial membrane system.

An artificial membrane system was adapted to feed Ornithodoros turicata (Ixodida: Argasidae) larvae from a laboratory colony using defibrinated swine blood. Aspects related to larval feeding and moulting to the first nymphal instar were evaluated. A total of 55.6% of all larvae exposed to the artificial membrane in two experimental groups fed to repletion and 98.0% of all fed larvae moulted. Mortality rates of first instar nymphs differed significantly depending on the sorting tools used to handle engorged larvae (χ2 = 35.578, P < 0.0001): engorged larvae handled with featherweight forceps showed significantly higher mortality (odds ratio = 4.441) than those handled with a camel-hair brush. Differences in the physical properties of the forceps and camel-hair brush may affect the viability of fragile soft tick larvae even when care and the same technique are used to sort them during experimental manipulations. The current results represent those of the first study to quantify successful feeding to repletion, moulting and post-moulting mortality rates in O. turicata larvae using an artificial membrane feeding system. Applications of the artificial membrane feeding system to fill gaps in current knowledge of soft tick biology and the study of soft tick-pathogen interactions are discussed.

Nonlinear Generation of Vorticity by Surface Waves.

We demonstrate that waves excited on a fluid surface produce local surface rotation owing to hydrodynamic nonlinearity. We examine theoretically the effect and obtain an explicit formula for the vertical vorticity in terms of the surface elevation. Our theoretical predictions are confirmed by measurements of surface motion in a cell with water where surface waves are excited by vertical and harmonic shaking the cell. The experimental data are in good agreement with the theoretical predictions. We discuss physical consequences of the effect.

Ion detector of time-of-flight mass spectrometer with registration of leading and trailing edges.

The accuracy of the ion flight time measurement in the time-of-flight mass spectrometer is critical to achieving high resolution. The pulse amplitude variation of the detector pulses leads to the registration time spread at a given pulse detection threshold. This time spread can be eliminated by determining the position of the pulse apex. To determine the position of the pulse apex, the output of the ion detector is fed simultaneously to the two channels of the time-to-digital converter. In this case, the first channel is set to register the leading edge, and the second channel is set to register the trailing edge of the pulse. Using a simple processing of the received data, the position of the pulse tip is determined. Thus, the dependence of the temporal position of the peak on the pulse amplitude is largely eliminated. Examples are given, and the efficiency of using this algorithm to increase the resolution of time-of-flight mass spectral peak registration is demonstrated.

Preliminary silylation for structure determination of oligomeric silsesquioxanes by matrix- assisted laser desorption/ionisation mass spectrometry.

The potential of preliminary silylation for the determination of numbers of hydroxyl groups in separate molecules of oligomeric silsesquioxanes by matrix-assisted laser desorption/ionisation mass spectrometry has been demonstrated for the first time. Derivatisations allowing the introduction of trimethylsilyl, tert-butyldimethylsilyl and pentafluorophenyldimethylsilyl groups were tested. It was shown that more reliable structure elucidation of individual oligomers can be achieved knowing the number of hydroxyl groups thus determined.

Spatial multi-criteria decision analysis for modelling suitable habitats of Ornithodoros soft ticks in the Western Palearctic region.

Ticks are economically and medically important ectoparasites due to the injuries inflicted through their bite, and their ability to transmit pathogens to humans, livestock, and wildlife. Whereas hard ticks have been intensively studied, little is known about soft ticks, even though they can also transmit pathogens, including African Swine Fever Virus (ASFV) affecting domestic and wild suids or Borrelia bacteria causing tick-borne relapsing fever (TBRF) in humans. We thus developed a regional model to identify suitable spatial areas for a community of nine Ornithodoros tick species (O. erraticus, O. sonrai, O. alactagalis, O. nereensis, O. tholozani, O. papillipes, O. tartakovskyi, O. asperus, O. verrucosus), which may be of medical and veterinary importance in the Western Palearctic region. Multi-Criteria Decision Analysis was used due to the relative scarcity of high-quality occurrence data. After an in-depth literature review on the ecological requirements of the selected tick community, five climate-related factors appeared critical for feeding activity and tick development: (i) a spring temperature exceeding 10°C to induce the end of winter soft tick quiescent period, (ii) a three-months summer temperature above 20°C to allow tick physiological activities, (iii) annual precipitation ranging from 60mm to 750mm and, in very arid areas, (iv) dry seasons interrupted by small rain showers to maintain minimum moisture inside their habitat along the year or (v) residual water provided by perennial rivers near habitats. We deliberately chose not to include biological factors such as host availability or vegetation patterns. A sensitivity analysis was done by performing multiple runs of the model altering the environmental variables, their suitability function, and their attributed weights. To validate the models, we used 355 occurrence data points, complemented by random points within sampled ecoregions. All models indicated suitable areas in the Mediterranean Basin and semi-desert areas in South-West and Central Asia. Most variability between models was observed along northern and southern edges of highly suitable areas. The predictions featured a relatively good accuracy with an average Area Under Curve (AUC) of 0.779. These first models provide a useful tool for estimating the global distribution of Ornithodoros ticks and targeting their surveillance in the Western Palearctic region.

[Electron microscopic study of the chemical structural asymmetry of myelin sheaths]. / Elektronno-mikroskopicheskoe issledovanie strukturno-khimicheskoi asimmetrii membran mielina.

Osmium washing of ultrathin sections of the frog sciatic nerve myelin fibres performed with 4% acetic acid solution preceded their treatment with the Dragendorf solution and ammonium paramolibdate. This enabled us to localize amine and phosphate groups of myelin membranes. The data obtained suggest that the majority of phospholipids of these membranes are located on the cytoplasmic surfaces, whereas glycolipids and cholesterol--on the extracellular ones. Examination of these surfaces by freeze--fracturing revealed different hydratation degrees in these surfaces. These results show that myelin membranes are most convenient models for the study of structural and chemical asymmetry of biological membranes.

[Polypous ethmoiditis]. / Polipoznyi étmoidit.

Investigations of etiology, pathogenesis and treatment of polypous ethmoiditis show the role of chronic inflammation, sensitization and autoimmune reactions in mechanisms of nasal polyposis (NP). The development of postoperative recurrences of NP depends on the microflora, defective microcirculation, permeability of the histohematic barriers of the nasal and labyrinthine mucosa and metabolism of glycosaminoglycanes in the above mucosa. Adequate treatment methods are suggested: He-Ne laser radiation, UV blood radiation, cryotherapy, corticosteroids. Promising are also autovaccine, autovaccine with tissue (polypous) antigen, ozone solutions.

[Use of demineralized allogeneic bone transplants for plastic surgery of osteomyelitic cavities]. / Primenenie demineralizovannykh kostnykh allotransplantatov dlia plastiki osteomieliticheskikh polostei.

Plasty of osteomyelitic cavities with demineralized bone transplants was performed in 55 patients. Different methods of the bone cavity plasty were used with regard for the state of soft tissues surrounding the pathological focus, changes in the purulent focus. In most of the patients (41) the cavity was filled up with the demineralized bone transplant formed with special reference to the size of the bone wound. In the other 14 patients with false joints complicated by osteomyelitis the bone allotransplant was put in the area of the defect as a duplicator. Good results were obtained in 53 (96.4%) patients.

[Bactericidal and bacteriostatic properties of Acryloxide copolymer in articular endoprosthesis]. / Bakteritsidnye i bakteriostaticheskie svoistva sopolimera "Akriloksid" pri éndoprotezirovanii sustavov.

Based upon bacteriological investigations the authors have proved bacteriostatic and sometimes bactericidal effects of the polymer material "Acryloxide". Endoprostheses made of it do not require sterilization which was demonstrated in operations of endoprosthesis of joints on 225 patients.

[Role of hospital infection in the occurrence of suppurative complications in children with the use of compression-distraction osteosynthesis]. / Rol' gospital'noi infektsii v vozniknovenii gnoinykh oslozhnenii u detei pri primenenii kompressionno-distraktsionnogo osteosinteza.

The authors have performed clinico-bacteriological investigations in 100 patients. Compressional-distractional osteosynthesis was used to correct deformities of the extremities. In 56 children purulent-inflammatory complications were observed. The main pathogenic agent of purulent complications was staphylococcus. The same phagotypes of staphylococcus were isolated from the skin around the wire, rhinopharynx of the children and medical personnel as well as the air of the hospital rooms.

[Bone and bone-muscle autoplasty in the treatment of chronic osteomyelitis]. / Kostnaia i myshechno-kostnaia autoplastika pri lechenii khronicheskogo osteomielita.

Osseous autoplasty of osteomyelitic cavities was used in 138 patients with different forms of chronic osteomyelitis. Complications were found in 8 patients. These patients had suppurations of the wound with sequestrations of osseous transplants.

[Substitution of an extensive defect of tissues after resection of the sternum in tumors]. / Zameshchenie obshirnogo defekta tkanei posle rezektsii grudiny po povodu opukholi.

An original method of substitution of great defect of the soft tissues and osteochondral part of the chest wall after resection of the sternum for a malignant tumor is described. Operations were made on 4 patients. Favorable results were noted in all the patients. The terms of follow-up were from 6 to 25 months.

Efficacy and safety of premedication with oral ketamine for day-case adenoidectomy compared with rectal diazepam/diclofenac and EMLA.

BACKGROUND: Because of its pain-attenuating and sedative properties oral ketamine has been used as premedication in children and adults. We wanted to compare in children scheduled for adenoidectomy safety and efficacy of oral ketamine with a premedication that causes similar preoperative sedation and relief of pain at the venepuncture site. We also evaluated the effect of i.v. glycopyrrolate added to these combinations. METHODS: One hundred children between 10 and 15 kg of body weight scheduled for day-case adenoidectomy were randomly assigned to one of four groups: groups DG and DS received diclofenac 12.5 mg and diazepam 0.5 mg/kg rectally, EMLA cream at the venepuncture site, and placebo orally; groups KG and KS received ketamine 6.0 mg/kg orally, placebo cream at the puncture site, and placebo rectally; additionally, groups DG and KG received glycopyrrolate 5 microg/kg, and groups DS and KS received placebo intravenously. We recorded perioperatively scores (open scale 1-9) for stridor, sedation, bleeding, nausea, pain, heart rate, the need for analgesics and registered psychotomimesis and well-being at home. RESULTS: The children of the K-groups became more tearful during separation from their parents (P=0.0072). No other differences were found between the ketamine and diazepam/diclofenac groups before and after premedication until induction of anaesthesia. Oral ketamine produced unpleasant psychotomimesis in four out of 59 children. During the first 10 min postoperatively, the score for stridor was significantly higher in group KS than in the D-groups; stridor scores > or = 6 were seen in one child of the D-groups (DS) and in six children of the K-groups (n.s.), of whom three developed laryngospasm (one reintubation). Glycopyrrolate diminished salivation in all groups, but had no effect on stridor scores. Additionally, glycopyrrolate delayed the onset of eating at home. CONCLUSION: Premedication with racemic oral ketamine 6 mg/kg does not seem to be suitable for upper airway procedures. Addition of i.v. glycopyrrolate before the induction of anaesthesia significantly reduced the scores for salivation.