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PubMed1991

Gas flow distribution in distal high frequency jet ventilation and lung thorax compliance.

To investigate the influence of changes in thorax and lung compliance on ventilation during distal High Frequency Jet Ventilation (HFJV), similar ventilator settings were compared before and after changing the compliance in two groups of anaesthetized mongrel dogs. Each period of distal HFJV was preceded by adequate Intermittent Positive Pressure Ventilation (IPPV) to assure a start with baseline values. In Group 1 (n = 7), thorax compliance was changed by chest strapping, while in Group 2 (n = 7) lung compliance was changed by inducing acute lung injury by injection of oleic acid into the right atrium. Gas flow distribution in the ventilatory circuit during distal HFJV was determined before and after the changes in compliance were induced. Comparing similar ventilator settings during distal HFJV in the same dog, a decrease in lung or thorax compliance led to changes in gas flow distribution in the ventilatory circuit. Entrainment was decreased and bypass increased with a negative effect on the gas volume entering the lungs and on gas exchange. The results indicate that distal HFJV should be regarded as pressure-limited ventilation.

Animals↗
PubMed2005

[Anaesthesia method in the operation of voice sulus in children].

OBJECTIVE: To explore the anaesthesia method in the operation of voice sulus in children. METHOD: Before operation about 30 minutes, the patient was injected Atropin 0.02 mg/kg ( the dose of maximum < or = 0.5 mg), next to inject midazolam (0.08 mg/kg), scoline (2 mg/kg) into vein, then the operator put the direct laryngoscope to perform operation. The anaesthetist put a tube to subgottis about 1.5-2.0 cm through the laryngoscope, and the end of the tube was linked to respiratory machine (TKP-400), the pressure of oxygen is 30-50 kPa, frequency is 100-120 min. The anaesthesia maintain was injected by 0.2% disoprofol and 0.2% scoline 6-8 ml/(kg x h). The varies of HR, BP before anesthesia, when putting the laryngoscope and 5 minutes after that, 2 minutes after quilting laryngoscope and at the recovering time were recorded. RESULT: All the operations were successful, none of short of oxygen and none of accumulating of CO2. The recovering were quickly within 5-6 minutes after stopping anaesthesia. CONCLUSION: The anaesthesia of injecting THEJV in vein in operating voice sulus in children is safe and suitable.

Anesthesia, Intravenous↗
PubMed1979

Determination of morphine and its major metabolite, morphine-3-glucuronide, in blood by high-performance liquid chromatography with electrochemical detection.

The construction of an electrochemical detector flow cell for high-performance liquid chromatography from stainless steel, which also serves as the auxiliary electrode, is described. Glassy carbon is used for the working electrode in a novel configuration based on a hybrid of the wall-jet and thin-layer arrangements. Application of the detector to the determination of morphine in small blood samples is described. The metabolite, morphine-3-glucuronide, is also determined by hydrolysis with beta-glucoronidase prior to extraction. The detector is capable of detecting less than 1 ng of morphine injected.

Chromatography, High Pressure Liquid↗
PubMed1999

[Endolaryngeal lipoaugmentation of the vocal cords].

Unilateral vocal cord paralysis or the loss of vocal cord tissue results in incomplete glottic closure (internal-paresis) with a consequent hoarseness and poor voice quality. Improving glottic incompetence, instead of the previously used paraffin, teflon is a widely accepted and most commonly used substance at present for vocal cord medialization. Using intracordal teflon injection of for decades had proven that it has limitations and potential complications to the human body. Beside the well-known external "phono-surgical" methods, a wide interest has been shown in endolaryngeal phono-surgery and in finding the ideal and most available biocompatible substances for the procedure. Papers have been issued about the promising results of autologus fat injection for medialization of the paralyzed vocal fold in the early '90s. In this paper the authors report on their slightly modified endolaryngeal intracordal autologus fat injection procedure, and its promising results. The first three patients (a left side glottic paralysis, a bilateral internal paresis and a left side internal paresis) experienced an improvement in their voice right after the medialization procedure, what remained the same during the 11 months follow-up period. Using supraglottic jet ventilation during general anaesthesia provides very good access to the operating field. Monitoring of neuro-muscular block makes possible an intraoperative examination of glottic closure by the protective reflex of the larynx. Incouraged by this initial results the authors suggest the autologus fat as an easy available, ideal substance for increasing (augmenting) the loss of vocal cord tissue.

Adipose Tissue↗
PubMed1988

Echocardiographic imaging of the left ventricle by peripheral intravenous injection of echo contrast agent.

With the use of a new echo contrast agent (ECA) that consists of a suspension with microbubbles (100% less than 3.9 micron in a moving system), we were able to opacify the left ventricle by peripheral intravenous injection in 124 of 130 patients (95%) without shunt connection. In 12 patients with aortic valve disease we measured the opacification of the right and left ventricles videodensitometrically by means of increasing doses. Dose 1 (8.7 ml ECA) and dose 4 (50 ml ECA) led to no significant difference in intensity in the right ventricle (168 +/- 32 vs 184 +/- 16 units, respectively; p greater than 0.05); however, opacification of the left ventricle was significantly more evident after dose 4 (60 +/- 60 vs 88 +/- 62 units, respectively; p less than 0.05). On the basis of the farthest distance reached by the regurgitant microbubbles from the aortic valve, the severity of regurgitation was graded on a four-point scale; the results were compared with those of aortography. A significant correlation (r = 0.98, n = 9) was found between ECA grading and aortography in the evaluation of the severity of aortic insufficiency. In addition, flow characteristics in patients with mitral stenosis, aortic insufficiency, and the regurgitation jet in incompetent aortic prosthesis in connection with diastolic inflow over the mitral valve were described. Moreover, it was possible to differentiate between inflow of ECA into the left atrium via an atrial septal defect and across the pulmonary vascular bed. No adverse effects were reported by the patients. Left ventricular end-diastolic volume index, end-systolic volume index, stroke volume index, and ejection fraction were determined before and after intravenous injection of increasing doses of ECA by means of the area-length method of Sandler and Dodge. Even after dose 4 we observed no significant changes in left ventricular function. The values before and after injection were in the range of intra- and interobserver reproducibility. Only three patients reported a slight taste sensation. In nine patients with a history of allergies there were no side effects.

Aortic Valve Insufficiency↗
PubMedDate not supplied

Study of specific immune response to unadsorbed concentrated tetanus vaccine administered by intradermal route to non-immunized persons in the last ten years.

Investigations of anti-tetanus response, in 404 subjects, most of them aged 60, being non-immunized for at least 10 years, stressed out the fact that 28.7% were not protected and 6.18% presented a protecting titer of 0.01 IU/ml, evaluated by "in vivo" protection test in mice. Some subjects were immunized with unadsorbed Tetanus vaccine (10 Lf/0.1 ml/dose) by i.d. route, using Jet-injector, and the others with adsorbed Tetanus vaccine (0.5 ml/dose), by i.m. route, using the needle and syringe. The vaccines were well tolerated and adverse reactions were not recorded. After 30 days, a single vaccine dose produced a protecting effect in 97.45% of non-protected subjects, belonging to i.d. immunized group, and also in 93.33% belonging to i.m. immunized group. 30 days after the administration of a second dose, protection set up in all subjects, no matter of vaccine type and administration route used. For a continuous reduction of tetanus morbidity, the authors suggest a specific periodical immunization of non-protected persons, selected by serological screening, using unadsorbed Tetanus vaccine, administered by i.d. route by means of the Jet-injector.

Adsorption↗
PubMed1994

Variations in flows and pressures during jet ventilation in the infant: a model study.

Ventilatory flow rates with either He-O2 (heliox) or N2-O2 (nitrox) mixtures during high frequency jet ventilation (HFJV) were calculated using a mathematical model, and were measured in a physical monoalveolar model of the infant lung. A constant flow was delivered to the model (Vd) drawing with it an entrained flow (Ve). When the inspiratory time (Tl) was long, a back flow (Vr) was generated that increased progressively as the alveolar pressure increased. In order to reduce Vr, the reflux time (Tr), i.e., the time needed for the injected gas to reflux, was measured (Trm) and calculated (Trc) with the model. The Tr depends on both chest-lung compliance and resistance to reflux as well as on the Ve/Vd ratio. For a given setting of the ventilator, values of Trm and Trc were significantly lower with heliox than nitrox (P < 0.01), and the correlation between Trm and Trc were fair with both gases. Tidal volume (VT) was calculated when the Tl was interrupted at Tr. The values of VT were significantly higher with helix than nitrox (P < 0.05). It is concluded that the evaluation of Tr during HFJV may provide useful information for setting the ventilator.

Airway Resistance↗
PubMed1994

Behavior-dependent activity labeling in the central complex of Drosophila during controlled visual stimulation.

3H-2-deoxyglucose (2-DG) is used as a histological marker to study the spatial distribution of neuronal activity in the central brain of Drosophila melanogaster under controlled stimulus conditions. Tethered flies injected with the label are kept for 45-90 minutes in the center of a rotating drum carrying on its periphery a single black vertical stripe or a periodic grating. In either stimulus situation, one-half of the flies walk on top of a small black styrofoam ball floating on a jet of air, and one-half are kept flying 1.5 mm above the ball. 1) During walking on the styrofoam ball little 2-DG accumulates in the central brain. The area in and around the ellipsoid body as well as several tracts are weakly labeled. 2) After flight, labeling patterns are more distinct. The following labeled structures can be identified: ventral bodies, ring neurons of the ellipsoid body, the region of the inferior bridge, fiber tracts connecting the central complex to other parts of the protocerebrum, and tracts in the subesophageal and dorsal brain. These contrast with fan-shaped body and protocerebral lobes, which are only weakly labeled. 3) Not only flight and walking lead to distinct staining patterns but also the two visual stimuli. With the single stripe, in most flies the caudal layers of the ellipsoid body accumulate more 2-DG than the rostral ones. With the striped drum, the ellipsoid body is uniformly labeled. 4) Other stimulus-related features are found less regularly: Unilateral distribution of 2-DG in or around the noduli was observed in several flies that had been exposed to a rotating single stripe. In one preparation, two strongly marked individual neurons of the protocerebral bridge can be tentatively identified. The labeling patterns support earlier notions that the central complex is involved in the initiation and organization of behavior and that it integrates visual data of the two brain hemispheres.

Animals↗
PubMed1998

Resynchronisation of a diurnal rodent circadian clock accelerated by a melatonin agonist.

Using 'jet lag' paradigms involving phase shifts in the light-dark (LD) cycle, we studied the effects of S-20098 on the circadian clock of a diurnal rodent. Arvicanthis mordax, entrained to a regular LD cycle, were subjected to advance shifts (i.e. 4, 6 or 8 h) in the LD cycle and injected with vehicle or the melatonin agonist S-20098 (20 mg/kg) the day of the shift (and also on subsequent days in the 6 h or 8 h shift paradigms). In each condition, S-20098 accelerated by about 30% resynchronization to the new LD cycle. These data, which are the first to demonstrate the chronobiotic effects of a melatonin agonist in a diurnal rodent, provide new insights for the design of human chronopharmacological protocols.

Acetamides↗
PubMed2003

Effect of a laser prepulse on a narrow-cone ejection of MeV electrons from a gas jet irradiated by an ultrashort laser pulse.

Spatial and energy distributions of energetic electrons produced by an ultrashort, intense laser pulse with a short focal length optical system (Ti:sapphire, 12 TW, 50 fs, lambda=790 nm, f/3.5) in a He gas jet are measured. They are shown to depend strongly on the contrast ratio and shape of the laser prepulse. The wave breaking of the plasma waves at the front of the shock wave formed by a proper laser prepulse is found to make a narrow-cone (0.1pi mm mrad) electron injection. These electrons are further accelerated by the plasma wake field generated by the laser pulse up to tens of MeV forming a Maxwell-like energy distribution. In the case of nonmonotonic prepulse, hydrodynamic instability at the shock front leads to a broader, spotted spatial distribution. The numerical analysis based on a two-dimensional (2D) hydrodynamic (for the laser prepulse) and 2D particle-in-cell (PIC) simulation justifies the mechanism of electron acceleration. The PIC calculation predicts that electrons with energy from 10 to 40 MeV form a bunch with a pulse duration of about 40 fs.

Journal Article↗
PubMed1990

Outbreak of Mycobacterium chelonae infection associated with use of jet injectors.

Between January 1 and May 15, 1988, foot infections due to Mycobacterium chelonae subspecies abscessus were diagnosed in eight persons who had undergone invasive procedures at a podiatry office. A cohort study was performed to evaluate risk factors for disease. Persons who underwent procedures before 10:30 AM were more likely to have developed infection than those with procedures after that time (relative risk, 5.6). In addition, procedures involving any of the second through fourth toes were more likely to have resulted in infection than procedures involving only the first and/or fifth toes (relative risk, 4.4). Persons with 0, 1, or 2 risk factors had attack rates of 5%, 14%, and 60%, respectively. Mycobacterium chelonae subspecies abscessus organisms of the same antimicrobial resistance pattern as the patients' strains were cultured from distilled water in a reusable, nonsterilized container. A jet injector used to administer lidocaine was held between procedures in a mixture of the distilled water and a disinfectant as recommended by the manufacturer. Inoculation of patients with mycobacteria by the jet injector may have only occurred early in the day due to slow killing of the bacteria by the disinfectant. The outbreak emphasizes the pathogenicity of this water-associated organism and the need for high-level disinfection of jet injectors.

Abscess↗
PubMed2002

Transonic injection in interaction with transverse compressible flow.

An extensive study devoted to modelling blade cooling was undertaken at CEAT a few years ago in collaboration with SNECMA. For the turbomachinery applications, an experimental configuration of a turbulent boundary layer with heat transfer was studied for compressible and incompressible flows. The research presented here is a part of that study and this paper reports on the experimental results of an investigation concerned with a row of transonic jets interacting with a transverse flow. In many applications, the cooling layer does not emerge onto the surface from a tangential slot but comes from a slot normal to or inclined to what is otherwise a flush surface. In this case the freestream interacts with the coolant flow. The secondary (jet) flow is introduced at an angle of 45 degrees to the mainstream flow direction. Visualization studies using the surface flow patterns and surface temperature flow patterns are reported and discussed.

Journal Article↗
PubMed2005

Piezo- and solenoid valve-based liquid dispensing for miniaturized assays.

Miniaturization of biological assays requires dispensing liquids in the submicroliter range of volumes. Accuracy and reproducibility of dispensing this range depend on both the dispenser and the receptacle in which the assay is constructed. Miniaturization technologies developed by Aurora Discovery, Inc. (San Diego, CA) include high-density multiwell plates for assay samples and reagent storage, as well as piezo-based and solenoid valve-based liquid dispensers. Some basic principles of small-volume dispensing by jetting are described to provide context for dispenser design and function. Performance of the latest instruments incorporating these dispensing devices is presented.

Biological Assay↗
PubMed2000

Formation, stability, and breakup of nanojets

Atomistic molecular dynamics simulations reveal the formation of nanojets with velocities up to 400 meters per second, created by pressurized injection of fluid propane through nanoscale convergent gold nozzles with heating or coating of the nozzle exterior surface to prevent formation of thick blocking films. The atomistic description is related to continuum hydrodynamic modeling through the derivation of a stochastic lubrication equation that includes thermally triggered fluctuations whose influence on the dynamical evolution increases as the jet dimensions become smaller. Emergence of double-cone neck shapes is predicted when the jet approaches nanoscale molecular dimensions, deviating from the long-thread universal similarity solution obtained in the absence of such fluctuations.

Journal Article↗
PubMed2005

[Determination of bioactive components in Semencustae by capillary electrophoresis with electrochemical detection].

A method of high performance capillary electrophoresis with electrochemical detection (CE-ECD) has been developed for the determination of five bioactive components in Semencustae, namely rutin, hyperoside, kaempferol, p-coumaric acid and quercetin. The effects of several factors such as the acidity and concentration of the running buffer, the separation voltage, the applied potential and the injection time on CE-ECD were investigated. Under the optimized conditions, these five components can be separated in a 50.0 mmol/L borax running buffer (pH 9.0) within 19 minutes. A 300 microm diameter carbon disk electrode was used as the working electrode positioned carefully opposite to the outlet of the capillary in a wall-jet configuration at potential of + 950 mV (vs. saturated calomel electrode as reference electrode, SCE). Good linear relationships were established between the peak current and concentration of analytes over two orders of magnitude. The detection limits (S/N = 3) were 1.93 x 10(-5), 3.55 x 10(-4), 3.65 x 10(-5), 1. 73 x 10(-5) and 1.46 x 10(-4) g/L for rutin, hyperoside, kaempferol, p-coumaric acid and quercetin, respectively. The method has been successfully applied to the determination of these analytes in Semencustae samples after a relatively simple extraction procedure, and the assay results were satisfactory.

Coumaric Acids↗
PubMed2000

Determination of Cd and Pb at microg/L levels by HHPN-beam injection flame furnace-AAS.

Flame-heated tubes are widespread in flame-AAS, mainly for the determination of hydride-forming elements. Instead of the introduction of gaseous compounds liquids can also be introduced continuously in such an absorption cell. With the aid of an HPLC pump the liquid is forced through a very fine nozzle, generating an aerosol beam less than 0.5 mm in diameter. This beam travels a distance of 10cm as a "free-flying aerosol jet" into the sample introduction hole of a metal tube furnace placed in the flame. Both introduction of the entire sample and the long residence time lead to a considerable improvement in power of detection. The detection limit for 100 microL samples amounts to 7 microg/L (Pb) and to 0.2 microg/L (Cd), which means an increase in power of detection of between one and two orders of magnitude compared to conventional flame-AAS. The relative standard deviation (100 microL sample volume, N = 10) was found to be 1.3% (signal area) for 600 microg/L Pb and to be 1.5% (signal-area) for 15 microg/L Cd. RSD values from measurements in peak-height amounted to 2.2% (Pb) and to 1.7% (Cd).

Journal Article↗
PubMed2004

Antigen delivery systems.

Many vaccine candidates are highly purified, sometimes monomeric antigens and as a result, not very immunogenic. Antigen delivery systems optimize the presentation of antigens. They also play a major role in solving the problem of there being an increasing number of vaccines but limited opportunities in which to include these vaccines in immunization programs. The number of injections is restricted and combining vaccines may lead to immunological and physicochemical incompatibility. In this review, the current status with respect to parenteral and mucosal delivery systems is discussed. These include lipid-based systems such as liposomes and immunostimulating complexes, as well as polymeric microspheres. In addition, developments in needle-free, dermal delivery devices such as jet injectors, microneedles and patches are presented.

Administration, Intranasal↗
PubMed1993

[Effect of 2 vaccination strategies on developments during the epidemic of meningococcal A meningitis in N'Djamena (Chad) in 1988].

From February till May 1988, during an epidemic of group-A meningococcal disease, 4542 cases of meningitis were reported in N'Djamena, the capital of Chad (550,000 inhabitants). A first selective vaccination campaign was carried out between 5 and 14 March; 156,500 vaccine doses (polyvalent: group A and C: Institut Mérieux) were given using jet injectors. The target population for this first campaign consisted of groups such as school-children and the armed forces. As the epidemic continued, a mass vaccination campaign was implemented one month later between 8 and 14 April 1988; this was targeted at the whole population above 1 year of age, not previously immunized, and 266,738 doses of vaccine were injected. One week after the start of the second campaign, the number of reported cases fell sharply and, within four weeks, the epidemic was halted. The vaccination coverage rate, evaluated by a WHO cluster survey method in people above one year of age, was 95.5%. These results show (i) the failure of selective vaccination, restricted to only at-risk groups, to halt the epidemic; (ii) the efficacy of the mass vaccination campaign aimed at the whole population; and (iii) the feasibility in tropical Africa of such a mass campaign which must be carried out in a few days.

Adolescent↗