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PubMedDate not supplied

A comparison of proximal and distal high-frequency jet ventilation in an experimental animal model.

High-frequency jet ventilation using either a proximal or a distal endotracheal injection site through a triple-lumen endotracheal tube was studied in 10 adult cats. The comparative effects on pulmonary gas exchange, tracheal pressure, heart rate, and blood pressure were examined for each injection site at both high (8-12 pounds per square inch [PSI] and low (5-8 PSI) jet-driving pressures in normal and lung-injured cats. Lung injury was created by modification of a surfactant washout technique previously demonstrated in rabbits. Alveolar ventilation (PaCO2) was found to be significantly better with distal than with proximal jet injection under all experimental conditions. At high jet-driving pressures, peak inspiratory pressure was higher in both normal (p = 0.03) and lung-injured cats (p = 0.002) with distal high-frequency jet ventilation. In addition, lung-injured animals were observed to have higher distal mean airway pressures at high jet-driving pressures (p less than 0.01). No differences in oxygenation were found in any circumstances. The results of this animal study suggest that distal high-frequency jet ventilation may be more effective in those situations in which improvement in alveolar ventilation is the major goal and that during proximal high-frequency jet ventilation airway pressures should be monitored as far distally as possible.

Animals↗
PubMed1993

Jet ring cell: a tool for flow injection spectroscopy and microscopy on a renewable solid support.

A new flow cell design for spectroscopic measurements of suspensions, the jet ring cell, is introduced. This cell exploits radial flow through a narrow ring-shaped gap to retain suspended particles within the detection region. This ring constitutes a detection volume of well-defined area from which the trapped particles can be instantaneously removed at will. The bed of particles thus forms a renewable surface, which can be probed by reflectance, fluorescence, or chemiluminescence using a microscope or optical fiber. This device should prove useful for microscopic study of cells, for automated immunoassays, and for preconcentration of analytes on sorbents with in situ spectroscopic detection. In conjunction with a fiber optic detection system, the jet ring cell becomes a component of a renewable chemical sensor system.

Animals↗
PubMed1976

[Booster vaccination with a diphtheria-tetanus vaccine for dermo-jet with low diphtheria toxoid content].

Indications are provided on how the organization of polyvaccinations against tuberculosis, poliomyelitis and diphtheria-tetanus in school collectivities can be rationalized. 19 persons aged 19-20 years were vaccinated intradermally with 1.5 Lf diphtheria toxoid and 15 Lf tetanus toxoid (contained in 0.1 ml) by means of a single injection with a jet injector (Dermo-Jet). In cases which had not previously been immunized, vaccination with the toxoid doses employed did not induce detectable antitoxin titers. In all cases which had previously been immunized the antitoxin titers after the booster injection were at least 400 times higher than the protection threshold for diphtheria and 1700 times higher than the protection threshold for tetanus. This was also the case in preimmunized cases which had no detectable antitoxin titer before the vaccination. The increase in antitoxin titer was inversely proportional to the prevaccinal titer in the manner of a logarithmic exponential function. It may be concluded from these results that the benefit of a booster vaccination is particularly high in poorly immunized persons whereas it is clearly limited in cases showing a high prevaccinal titer. The well tolerated intradermal vaccination with the jet injector (Dermo-Jet) can be considered as equivalent to the subcutaneous technic. From the point of view of organization (time consumption, problems of sterilization) this method is much preferable to intramuscular or subcutaneous vaccination.

Adult↗
PubMed2000

Sympathoinhibitory and depressor responses to long-term infusion of nifedipine in spontaneously hypertensive rats on high-salt diet.

Short-term (by hour) intracerebroventricular (i.c.v.) or i.v. infusion of nifedipine at low rates evokes parallel decreases in renal sympathetic nerve activity (RSNA) and blood pressure (BP) in spontaneously hypertensive rats (SHR). In the present study, effects of long-term administration of nifedipine on BP and control of sympathetic tone were examined in SHR on a high-salt (8%) diet. From 6 to 8 weeks of age, for 2 weeks concomitant with taking a high-salt diet, rats were also treated with subcutaneous infusion of nifedipine at 10, 50, or 100 microg/kg/h or vehicle solvent as control using osmotic minipumps. At the end of the 2-week treatment period, mean arterial pressure (MAP), heart rate (HR), and RSNA at rest and in response to air-jet stress, i.c.v. injection of the alpha-adrenoceptor agonist guanabenz (25 microg), and i.v. injection of the ganglionic blocker hexamethonium were recorded in conscious rats. In rats on nifedipine 50 or 100 microg/kg/h, resting MAP was significantly lower (136+/-4 or 130+/-4 vs. 145+/-2 mm Hg in control rats, p < 0.05 for both), the sympathoinhibitory and depressor responses to i.c.v. guanabenz were significantly decreased, and the absolute decreases in MAP in response to i.v. injection of hexamethonium were significantly smaller. Sympathoexcitatory and pressor responses to air-jet stress, however, were not affected by nifedipine. Infusion of nifedipine at the three rates for 2 weeks caused concentrations of plasma nifedipine in a dose-related manner. Nifedipine was not detected in tissues of rats treated with 10 microg/kg/h nifedipine but was present in brain and other tissues of rats treated with nifedipine at the two higher rates. Thus in SHR on high-salt intake long-term treatment with nifedipine at 50 or 100 microg/kg/h decreased resting BP and the sympathetic component in BP control. In addition to possible peripheral effects, long-term administration of nifedipine may also act centrally to decrease sympathetic activity and BP, likely by increasing activity in central pathways involving sympathoinhibition, but not in pathways involving sympathoexcitation as evaluated by air-stress.

Animals↗
PubMed2001

A model to assess the infection potential of jet injectors used in mass immunisation.

Jet injectors are needleless injectors that penetrate skin with high-pressure fluid. They have potential advantages over needles and syringes in mass immunisation programs, but concerns over their capacity to transfer blood-borne viruses have been a barrier to acceptance. Hepatitis B infection can transmit in 10 pl of blood; detection of such low volumes presents severe difficulties to such assessments. A model to assess jet injector safety was developed using injection of an inert buffer into calves and assaying the next injector discharge, representing the next dose of vaccine, for blood using a highly sensitive ELISA. Four injectors were tested: two with reusable heads and direct skin contact, one with single-use injector heads and one where the injector head discharged at a distance from the skin. All injectors tested transmitted significant (over 10 pl) volumes of blood; the volumes and frequency of contamination varied with injector. The source of the contamination was consistent with contamination by efflux of injected fluid and blood from the pressurised pocket in tissue that is formed during injection. This insight should inform the design of safe jet injectors.

Animals↗
PubMed2002

Large-scale extragalactic jets powered by very-high-energy gamma rays.

The radiative cooling of electrons responsible for the nonthermal synchrotron emission of large-scale jets of radiogalaxies and quasars requires quasicontinuous (in time and space) production of relativistic electrons throughout the jets over the scales exceeding 100 kpc. While in the standard paradigm of large-scale jets this implies in situ acceleration of electrons, we propose a different "nonacceleration" origin of these electrons, assuming that they are implemented all over the length of the jet through effective development of electromagnetic cascades initiated by extremely high-energy gamma rays injected into the jet from the central object.

Journal Article↗
PubMed1987

Blood glucose and free insulin levels after the administration of insulin by conventional syringe or jet injector in insulin treated type 2 diabetics.

UNLABELLED: The levels of blood glucose and free insulin were compared in 20 diabetic subjects (type 2) receiving one dose of a combination of fast-acting and intermediary-acting insulins in the morning by means of a needle syringe or a jet injector (SICIM, Italy), using minimum possible injecting power. A shift to the left in the free insulin profile, consequential to different pharmacokinetic characteristics of insulin when administered by means of a jet injector, was observed, although no significant differences were seen for free insulin levels. Statistically significantly higher blood glucose values (P less than 0.05) were recorded 6 and 9 h after insulin administration by means of a jet injector, as well as statistically significant higher MBG values (P less than 0.05), thus indicating a faster and shorter effect achieved in comparison to that produced by the syringe injected insulin. CONCLUSIONS: 1. When switching the method of insulin administration in patients from needle syringe to jet injections the power of the jet injector should be increased (it can be set in three different levels). If that is not possible, because of patient skin characteristics then the dose of intermediary acting insulin should be slightly increased. 2. No local or general side-effects were registered using minimum injecting power of jet injector. 3. The results of the controlled poll have shown that this method of insulin administration is less painful and simpler for patients. The great majority of the patients would like to possess a jet injector.

Adult↗
PubMedDate not supplied

The application of insulin using the jet injector DG-77.

UNLABELLED: To avoid soreness and psychic stress following insulin injections by needle and syringe, the new jet injector DG-77 was used. It is a portable percutaneous pressure device with a spring, simple to operate which can be used to apply two different types of insulin. Thirty type 1 and type 2a diabetic patients participated in the study (10 females, 20 males). Insulin was applied using a needle and the DG-77 device in the same region of the body. A standardized questionnaire was compiled concerning simplicity of application, soreness, wish to possess the device and the possibility of acquiring it. The results obtained regarding the type of application were as follows: traditional way: glycemia: at 07(00)-8.5, 10(00)-10.5, 13(00)-7.4 mmol/l; insulinemia: at 07(00)-7.5, 10(00)-20.2, 13(00)-21.0 mU/l; jet injector: glycemia - at 07(00)-8.4, 10(00)-10.4, 13(00)-8.4 mmol/l; insulinemia: at 07(00)-2.8, 10(00)-12.3, 13(00)-20.0 mU/l, which was not statistically significant; for glycemia: at 10(00), t = 0.110, p greater than 0.05, at 13(00), t = 1.88, p greater than 0.05, and for insulinemia at 10(00), t = 0.82, p greater than 0.05, and at 13(00), t = 1.23, p greater than 0.05. IN CONCLUSION: 1) blood glucose and insulin control with the jet injector administration of insulin was equally successful as with the standard insulin application; 2) incidence of hematoma was not significant; 3) eighty-five percent of patients prefer the injector due to its simplicity of application, reduced soreness and would wish to possess the device.

Adult↗
PubMed1989

Doppler color flow mapping of simulated in vitro regurgitant jets: evaluation of the effects of orifice size and hemodynamic variables.

The spatial distribution of simulated regurgitant jets imaged by Doppler color flow mapping was evaluated under constant flow and pulsatile flow conditions. Jets were simulated through latex tubings of 3.2, 4.8, 6.35 and 7.9 mm by varying flow rates from 137 to 1,260 cc/min. Color jet area was linearly related to flow rate at each orifice (r = 0.96, SEE = 3.4; r = 0.99, SEE = 1.6; r = 0.97, SEE = 2.3; r = 0.97, SEE = 3.2, respectively), but significantly higher flow rates were required to maintain the same maximal spatial distribution of the jet at the larger regurgitant orifices. Constant flow jets were also simulated through needle orifices of 0.2, 0.5 and 1 mm, with a known total volume (5 cc) injected at varying flow rates and with differing absolute volumes injected at the same flow rate (0.2, 1.0 and 2.0 cc/s, respectively). Again, maximal color jet area was linearly related to flow rate at each orifice (r = 0.97, SEE = 2.3; r = 0.97, SEE = 2.4; r = 0.92, SEE = 3.9, respectively), but was not related to the absolute volume of regurgitation. Color encoding of regurgitant jets on Doppler color flow maps was demonstrated to be highly dependent on velocity and, hence, driving pressure, such that color encoding was obtained from a constant flow jet injected at a velocity of 4 m/s through an orifice of 0.04 mm diameter with flow rates as low as 0.008 cc/s. Mitral regurgitant jets were also simulated in a physiologic in vitro pulsatile flow model through three prosthetic valves with known regurgitant orifice sizes (0.2, 0.6 and 2.0 mm2). For each regurgitant orifice size, color jet area at each was linearly related to a regurgitant pressure drop (r = 0.98, SEE = 0.15; r = 0.97, SEE = 0.20; r = 0.97, SEE = 0.23, respectively), regurgitant stroke volume (r = 0.77, SEE = 0.55; r = 0.94, SEE = 0.30; r = 0.91, SEE = 0.41, respectively) and peak regurgitant flow rate (r = 0.98, SEE = 0.16; r = 0.97, SEE = 0.21; r = 0.93, SEE = 0.37, respectively), but the spatial distribution of the regurgitant jets was most highly dependent on the regurgitant pressure drop. Jet kinetic energy calculated from the summation of the individual pixel intensities integrated over the jet area was closely related to driving pressure (r = 0.84), but integration of the power mode area times pixel intensities provided the best estimation of regurgitant stroke volume (r = 0.80).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2002

Pharmacokinetics and pharmacodynamics of a new formulation of recombinant human growth hormone administered by ZomaJet 2 Vision, a new needle-free device, compared to subcutaneous administration using a conventional syringe.

The objective of the present study was to investigate the applicability of a new human growth hormone (Zomacton) formulation, administered both by a conventional syringe and by a new needle-free device (ZomaJet 2 Vision). The study was performed according to a randomized, controlled, three-period crossover design. On 3 separate days, all subjects received in a random order a single subcutaneous injection of 1.67 mg hGH as follows: Zomacton 4 mg/ml conventional syringe administration (Treatment A), Zomacton 10 mg/ml conventional syringe administration (Treatment B), or Zomacton 10 mg/ml ZomaJet 2 Vision administration (Treatment C). The pharmacokinetic parameters were assessed for the individual subjects in each group by noncompartmental methods. Bioequivalence was assessed based on log-transformed AUC and C(max) values. To investigate the effectiveness of two formulations and the different administration methods, the pharmacodynamic parameters (insulin-like growth factor-1 [IGF-1] and free fatty acids [FFA]) were also evaluated. No subjects were withdrawn due to adverse events. The local tolerance assessment (assessed by inspection)revealed no differences between ZomaJet2 Vision application and conventional injections by syringe. Administration of the new hGH formulation by syringe was found to be bioequivalent with the reference treatment, both based on AUC and C(max) values; the new formulation administered by use of ZomaJet 2 Vision was found to be bioequivalent based on AUC values only. When using the ZomaJet 2 Vision, the absorption of hGH was faster, resulting in higher C(max) values. The maximum hGH serum concentration of around 20 ng/ml was observed 3.5 to 4 hours after drug administration. The terminal half-life was found to be around 2.5 hours. Comparison of the pharmacodynamic profiles (both IGF-1 and FFA) demonstrated bioequieffectiveness. These results support the use of jet injectors as a viable alternative to the traditional injection pens.

Adult↗
PubMed1990

Devices for insulin administration.

There is a significant need for revised, safe, and more effective insulin-delivery methods than subcutaneous injections in the treatment of both type I (insulin-dependent) and type II (non-insulin-dependent) diabetes. The aim of this review is to describe the rationale and methods for better use of injection and infusion devices for intensive insulin therapy and to describe results of animal and human research that will lead to an implantable artificial pancreas. Injection devices, e.g., jet injectors, insulin pens, and access ports, cannot be considered as a major breakthrough in the quest for improved control, although they may improve the patient's comfort. External pumps have benefits over multiple injections and conventional insulin therapy only in specific subgroups of patients, e.g., those with recurrent severe hypoglycemia, but only when used by experienced personnel. The external artificial pancreas (Biostator) is also to be used by experienced personnel for limited clinical and research applications, e.g., surgery of the diabetic patient. The development of an implantable version of the artificial pancreas is linked to progress in the field of reliable long-duration glucose sensors. Finally, programmable implantable insulin pumps, used as an open-loop delivery system, are the most promising alternative to intensive subcutaneous insulin strategies in the short term, although clear evidence of improved safety and efficacy remains to be documented.

Diabetes Mellitus, Type 1↗
PubMedDate not supplied

Development of new jet injector for insulin therapy.

To improve diabetic patients' compliance to multiple injection protocols, we developed and tested a new insulin jet injector, the Preci-Jet 50. The prototype has the following features: small size (14 X 2 cm) and weight (160 g), capability of mixing two types of insulin, accuracy and reliability of the ejected volume (dose), ease of use and sterilization, simplicity of design, and capacity of adjusting jet pressure to individual skin resistance. The ejected volume, evaluated by gravimetry, was more accurate and more reliable with the injectors (N = 18) than with 0.5-cc disposable plastic syringes (N = 18). The dead space of the injectors (N = 16), as evaluated by isotopic recuperation of radioactive insulin, was minimal, allowing mixed insulin injections. The human-device interface evaluation demonstrated that diabetic patients (N = 13) learned easily to manipulate the injector and that their ability to use it properly improved after 1 mo of use. We conclude that this injector may be a practical tool for insulin-dependent diabetic patients.

Adult↗
PubMed2001

Persistence of the effects of Jet-A in a microcosm with releases from the sediment.

This study investigates both the methods and the multispecies and functional level effects of a release of a complex hydrocarbon mixture from sediments using a 60-d modified mixed flask culture (MFC) microcosm. Neat Jet-A was injected and mixed into the sediment with one nondosed and three dosed concentrations. Univariate and multivariate statistical and graphical techniques were used to detect patterns in the data. A slow release of the test material from the spiked sediment layer was obtained, and constituents of Jet-A were detected. Functional parameters (such as pH) were generally better at determining treatment groups than structural parameters (population densities). Analysis of the ability of the various parameters to detect treatment differences confirms that there is not one best indicator for the status of an ecological structure. Transient but statistically significant outcomes were seen at initial treatment concentrations as low as 2 microl/L. The higher concentration treatment groups could be identified as distinguished from nondosed or lower treatments at the end of the 63-d experiment. Each of the three multivariate techniques differed in their ability to distinguish treatment groups during the course of the experiment.

Animals↗
PubMed2004

Clusters of ionisation in nanometre targets for propane-experiments with a Jet Counter.

Further evidence on the reliability of the device called the Jet Counter (JC) for studying the formation of ionisation clusters at the nanometre level are presented. The new experimental data on the distributions of ionisation cluster size originating from a 2-10 nm size target in propane irradiated by 3.8 MeV alpha particles are described. The JC consists of a pulse-operated valve that injects an expanding jet of propane into an interaction chamber, where a sensitive volume in the form of a cylinder is created. The sensitive volume was irradiated by 3.8 MeV alpha particles. The resulting distribution of ion clusters, ranging from 2 to 10 nm in unit density gas, has been measured. A method of determining the efficiency of registration of single propane ions using an ion detector is described. A method of deconvolution of the measured to true cluster size distributions is also given. Finally, the measured cluster size distributions are compared with modelled distributions based on Monte Carlo calculations. The results for propane together with previous ones for nitrogen indicate the JC to be an efficient tool for the investigation of radiation quality at the nanometre level.

Algorithms↗
PubMed1996

Immunogenicity and safety of a new inactivated hepatitis A vaccine: a clinical trial with comparison of administration route.

A bicentre, controlled, randomized, open trial was carried out in order to compare the immunogenicity and the reactogenicity of PASTEUR MERIEUX Sérums et Vaccins inactivated Hepatitis A Vaccine on adults, when used with different routes of administration [intramuscular (i.m.), subcutaneous (s.c.) and needless injection using a Jet injector device]. Vaccines were given at two doses 6 months apart to 147 seronegative subjects. Anti-Hepatitis A virus (HAV) titres were performed at each visit by modified radioimmunoassay assay. After the first dose, 138 subjects except one seroconverted (s.c.). After booster dose, all subjects exhibited high levels of HAV antibodies. The higher titres were observed with Jet injector (GMT: 305 mIU ml-1 after the first dose and 3727 mIU ml-1 after the booster dose), followed by the i.m. route (210 mIU ml-1, 3152 mIU ml-1) and the s.c. route (165 mIU ml-1, 2082 mIU ml-1). No statistically significant differences were observed in the three paired comparisons (i.m. vs jet injector; jet vs s.c., im vs s. c.). This inactivated hepatitis A vaccine appeared to be highly immunogenic after one single dose and one booster 6 months later.

Adult↗