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PubMedDate not supplied

Noninvasive evaluation of systolic pressures of pulmonary artery and right ventricle using contrast-enhanced doppler echocardiography: comparative study using sonicated albumin or glucose solution.

Evaluation of pulmonary arterial pressure is essential for the diagnosis and management of patients with congenital heart disease; it is usually done by cardiac catheterization. An alternative, noninvasive method may be clinically more useful. The purpose of this study was to assess the usefulness of the noninvasive determination of systolic pressure of the pulmonary artery and right ventricle by contrast-enhanced Doppler echocardiography. We selected 30 pediatric patients (28 with trivial or nonsignificant tricuspid regurgitant Doppler signals and 2 with significant tricuspid regurgitant Doppler signals) aged 2 months to 21 years. The flow velocity of tricuspid regurgitation was measured with continuous-wave Doppler of the right ventricular inflow view or left parasternal or apical four-chamber view before and after injection of two types of contrast medium (hand-agitated 5% glucose or sonicated albumin). The systolic pressure of the pulmonary artery was assessed as the estimated right ventricular systolic pressure (albumin method) minus the peak pressure gradient across the pulmonary valve (nonenhanced Doppler method). After injection of hand-agitated 5% glucose and sonicated albumin, trivial tricuspid regurgitation signals were enhanced in 25 of 28 patients (89%). In two patients, spectral envelopes were well defined enough to obtain the peak systolic velocity of the tricuspid regurgitation jet without contrast medium injection. Peak velocity was not altered by injection of contrast medium in these patients. There was significant correlation between the estimation by contrast-enhanced Doppler using hand-agitated 5% glucose and the cardiac catheterization measurement of the transtricuspid pressure gradient (r = 0.88). The transtricuspid pressure gradients obtained by continuous-wave Doppler during sonicated albumin enhancement corresponded closely to those measured by cardiac catheterization (r = 0.95). Pulmonary arterial and right ventricular systolic pressures measured by Doppler using sonicated albumin and those obtained by cardiac catheterization were highly correlated (right ventricle, r = 0.96; pulmonary artery, r = 0.95). In conclusion, this technique may be a valuable noninvasive method for determining accurate right ventricular and pulmonary arterial systolic pressures.

Adolescent↗
PubMed2003

Jet expansion module for liquid-sampled GC-discharge ionization detection of liquefied gases.

A rugged jet expansion module was designed, built, and utilized to sample liquefied gas for gas chromatography-discharge ionization detector (GC-DID) analysis. The module is inserted at an intermediate stage between a higher pressure sample cylinder and lower pressure gas injection manifold. The title jet module permits selection of liquid-phase or vapor-phase sampling by setting the valve-cylinder orientation up or down (relative to gravity). It consists of a four-way stainless steel cross, plus the following components connected to pipe thread ports: (1) mechanical pressure gauge, -15 to +30 psig; (2) threaded nut with 0.010-in. jet orifice (connect to sample cylinder valve); (3) bellows valve (connect to GC manifold); (4) bellows valve (connect to expansion cylinder). Making use of the jet module, measurement of air concentration in [15N]ammonia and sulfur hexafluoride (single-component) samples was found to be significantly lower in the liquid phase by GC-DID. This compact apparatus enables phase-selective sampling, reduces primary manifold contamination, and improves operator safety.

Journal Article↗
PubMed1999

Brain renin-angiotensin system and sympathetic hyperactivity in rats after myocardial infarction.

Blockade of brain "ouabain" prevents the sympathetic hyperactivity and impairment of baroreflex function in rats with congestive heart failure (CHF). Because brain "ouabain" may act by activating the brain renin-angiotensin system (RAS), the aim of the present study was to assess whether chronic treatment with the AT1-receptor blocker losartan given centrally normalizes the sympathetic hyperactivity and impairment of baroreflex function in Wistar rats with CHF postmyocardial infarction (MI). After left coronary artery ligation (2 or 6 wk), rats received either intracerebroventricular losartan (1 mg. kg-1. day-1, CHF-Los) or vehicle (CHF-Veh) by osmotic minipumps. To assess possible peripheral effects of intracerebroventricular losartan, one set of CHF rats received the same rate of losartan subcutaneously. Sham-operated rats served as control. After 2 wk of treatment, mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) at rest and in response to air-jet stress and intracerebroventricular injection of the alpha2-adrenoceptor-agonist guanabenz were measured in conscious animals. Arterial baroreflex function was evaluated by ramp changes in MAP. Compared with sham groups, CHF-Veh groups showed impaired arterial baroreflex control of HR and RSNA, increased sympathoexcitatory and pressor responses to air-jet stress, and increased sympathoinhibitory and hypotensive responses to guanabenz. The latter is consistent with decreased activity in sympathoinhibitory pathways. Chronic intracerebroventricular infusion of losartan largely normalized these abnormalities. In CHF rats, the same rate of infusion of losartan subcutaneously was ineffective. In sham-operated rats, losartan intracerebroventricularly or subcutaneously did not affect sympathetic activity. We conclude that the chronic increase in sympathoexcitation, decrease in sympathoinhibition, and desensitized baroreflex function in CHF all appear to depend on the brain RAS, since this whole pattern of changes can be normalized by chronic central AT1-receptor blockade with losartan.

Angiotensin II↗
PubMed1980

[Betamethasone in the treatment of hypertrophic scars].

Creams containing corticosteroids are not efficient in the treatment of scar hypertrophy. In 23 patients Betamethason as a cristal suspension was injected into 32 hypertrophic scars by means of a jet-injector. The preparation has proven to reduce bulk and tension in mature scars, but had no effect on fresh and active scar formation, nor in preoperative prevention. The jet-injector is of advantage.

Betamethasone↗
PubMed1990

Carbon paste-tetrathiafulvalene amperometric enzyme electrode forthe determination of glucose in flowing systems.

The development of a carbon paste-tetrathiafulvalene amperometric enzyme electrode for the determination of glucose in flowing streams is described. The enzyme electrode is operated in a flow-through detector based on the wall-jet configuration under flow injection (FI) and steady-state (SS) conditions. Under FI conditions, high precision (0.6%) and sample throughput (120 samples h-1) are possible. Moreover no pre-conditioning of the electrode is required. The flow system is suitable for the determination of glucose in whole blood without sample dilution. With proper orientation of the jet with respect to the enzyme electrode, high accuracy can be obtained under SS conditions.

Blood Glucose↗
PubMedDate not supplied

Comparative effects of 5% ethanolamine oleate versus 5% sodium morrhuate for sclerotherapy of oesophageal varices.

Forty-five cirrhotic patients with oesophageal varices were randomized to receive endoscopic injection sclerotherapy with either 5% ethanolamine oleate (EO), or 5% sodium morrhuate (SM). In the EO group, there was a statistically significant higher rate of disappearance of red colour signs on the varices a week after the initial session of sclerotherapy than in the SM group (91.3% vs 45.5%, P less than 0.05). A jet-like bleeding from injection sites at the second session of sclerotherapy occurred in three patients in the SM group and they experienced blurred vision. There was no such occurrence in the EO group. Oesophageal bleeding requiring blood transfusion during the course of repeated sclerotherapy occurred only in the SM group (five patients): bleeding was from a partly thrombosed varix and in four was from oesophageal ulcers. We found that EO administered intravariceally is more efficacious than SM for sclerotherapy of oesophageal varices.

Esophageal and Gastric Varices↗
PubMed1990

Pitfalls in the display of color Doppler jet areas: combined variability due to Doppler angle, frame rate, and scanning direction.

UNLABELLED: The Doppler color jet area depicting a regurgitant or shunt lesion may be useful in estimating its severity. However, color jet area may be affected by technical factors. We studied the combined effects of Doppler angle, frame rate, and scanning direction on the Doppler color jet area of a free jet with 10-mL injection. RESULTS: (1) Angle effects: color flow area was 11.7 +/- 2.0 cm2 at a Doppler angle of 20 degrees , and 2.3 +/- 1.2 cm2 at an angle of 60 degrees , when other parameters were kept constant (frame rate = 12 frames/sec, reverse scanning direction). (2) Frame rate effects: with other parameters kept constant (Doppler angle = 20 degrees , reverse scanning direction), color flow area was 11.7 +/- 2.0 cm2 at a rate of 12 frames/sec and 6.5 +/- 1.8 cm2 at 6 frames/sec. (3) Scanning direction effects: with other parameters kept constant (Doppler angle = 20 degrees , frame rate = 9 frames/sec), color flow area was 7.3 +/- 1.1 cm2 with scanning in the reverse direction, and 20.5 +/- 1.6 cm2 with scanning in the forward direction. (4) Combined effects: In our in vitro studies, the maximum color flow area was 20.5 +/- 1.6 cm2, and the minimum area was 1.5 +/- 0.2 cm2 (nearly twelve-fold). CONCLUSIONS: Doppler color jet area correlated inversely with Doppler angle (P less than 0.01) and directly with frame rate (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography, Doppler↗
PubMed1982

Release of nickel into fluid stored in the reservoir of Dermo-Jets.

Release of nickel into triamcinolone acetonide suspensions stored in the reservoir of a Dermo-Jet was demonstrated by electrothermal atomic absorption spectrometry. Increased urinary nickel excretion was found for three days following intradermal injections (with the Dermo-Jet) of triamcinolone acetonide in patients suffering from alopecia areata. The dimethylglyoxime test showed that the internal rod of the reservoir as well as metallic internal parts of the nozzle leached appreciable amounts of nickel, even before any clinical use.

Alopecia Areata↗
PubMed1991

[Injections without needles in the treatment of insulin-dependent diabetes].

Jet injectors, which force a fluid under considerable pressure through a very small opening, have recently become available for subcutaneous administration of insulin. Use of the new devices introduced on the market is neither simpler nor more complicated than use of a syringe. Although jet injectors are highly attractive to both patients and parents, they can be used in only a limited range of diabetics. Main limitations to more widespread use include: 1) the small capacity of the devices which cannot inject more than 20 units of 40 unit/ml insulin; 2) modifications in the pharmacokinetic effects of insulins, especially long-acting insulins; 3) the high price of the injectors. Young children, who often find it difficult to accept injections, may be the main potential target for jet injector therapy. A trial period at home should always be scheduled before considering the purchase of a jet injector.

Adolescent↗
PubMed2004

Platelet activating factor receptor binding plays a critical role in jet fuel-induced immune suppression.

Applying military jet fuel (JP-8) or commercial jet fuel (Jet-A) to the skin of mice suppresses the immune response in a dose-dependent manner. The release of biological response modifiers, particularly prostaglandin E2 (PGE2), is a critical step in activating immune suppression. Previous studies have shown that injecting selective cyclooxygenase-2 inhibitors into jet fuel-treated mice blocks immune suppression. Because the inflammatory phospholipid mediator, platelet-activating factor (PAF), up-regulates cyclooxygenase-2 production and PGE2 synthesis by keratinocytes, we tested the hypothesis that PAF-receptor binding plays a role in jet fuel-induced immune suppression. Treating keratinocyte cultures with PAF and/or jet fuel (JP-8 and Jet-A) stimulates PGE2 secretion. Jet fuel-induced PGE2 production was suppressed by treating the keratinocytes with specific PAF-receptor antagonists. Injecting mice with PAF, or treating the skin of the mice with JP-8, or Jet-A, induced immune suppression. Jet fuel-induced immune suppression was blocked when the jet fuel-treated mice were injected with PAF-receptor antagonists before treatment. Jet fuel treatment has been reported to activate oxidative stress and treating the mice with anti-oxidants (Vitamins C, or E or beta-hydroxy toluene), before jet fuel application, interfered with immune suppression. These findings confirm previous studies showing that PAF-receptor binding can modulate immune function. Furthermore, they suggest that PAF-receptor binding may be an early event in the induction of immune suppression by immunotoxic environmental agents that target the skin.

Administration, Cutaneous↗
PubMed1981

Evaluation of selected aerosol-control measures on flow sorters.

Flow sorters produce microdroplets as part of their normal operation, and if these microdroplets escape into the room, they are potentially hazardous. We have tested several aerosol-control measures on a commercial flow sorter. To accomplish this, T-4 phages were introduced into the sorter's liquid jet through the sample injection tube, and culture plates containing lawns of T-4-sensitive Escherichia coli bacteria were exposed around the sorter for each operational configuration. After the exposure, the plates were incubated and then scored for plaques. A single phage-containing microdroplet landing on a plate was sufficient to cause a plaque of lysed bacteria to form. The number of plaques was thus an indicator of how much aerosol was released for each configuration. Aerosols were controlled most effectively by catching the central, undeflected stream in a vacuum-exhausted tube; this technique, coupled with the manufacturer's vacuum-exhaustion of the air around the sorting location, produced no plaques. Several failure modes were tested, including having the central stream hit the outside of the catch-tube or deflection plates, and loss the manufacturer's vacuum-exhaustion system. Many flow sorters allow the underflected stream to splash into a flask or beaker, an approach that produces the most plaques if instrument-failure modes are excluded. The simple addition of a catch-tube removed this major contributor to the aerosol production.

Accident Prevention↗
PubMed1989

Neurological damage in a cardiopulmonary arrest model in the rat.

In view of the interest in cerebral protection in the framework of cardiopulmonary arrest (CPA), we assessed the neurological damage in a CPA model in the rat. CPA was induced in anesthetized Wistar rats by discontinuation of the jet ventilation and intracardiac injection of KCl. The animals were resuscitated after a CPA of either 7 min, 10.5 min, or 14 min. Six rats were used as nonischemic controls. All nonischemic rats survived, whereas in the resuscitated rats the 7-day survival rate decreased with increasing CPA duration. In the resuscitated rats, the neurological score was worse than in the control rats, and the score after 10.5-min CPA was worse than after 7-min CPA. Seizures were observed in 68% of resuscitated rats. Histopathological evaluation revealed moderate but selective neuronal necrosis in the hippocampus of all ischemic rats, and no cortical necrosis. However, neither the occurrence of seizures nor the extent of neuronal necrosis was related to the CPA duration. We conclude that in this model survival rate, neurological score, occurrence of seizures, and histopathological assessment can be used to evaluate neurological damage, although the contribution of other organ failure to these effects cannot be excluded.

Animals↗
PubMed1995

Matrix-assisted laser desorption ionization of neutral clusters composed of matrix and analyte molecules.

A new version of the matrix-assisted laser desorption ionization experiment is described. Composed clusters created by laser desorption of a mixture of analyte and matrix material were injected into a supersonic jet and then analyzed by multiphoton ionization time-of-flight mass spectrometry. Selective two-photon ionization of matrix molecules of a cluster component caused their dissociation, followed by intercluster proton or cation transfer to an analyte that is transparent for the wavelength of ionizing radiation. The intercluster charge transfer reactions are the only pathway for analyte ion formation under these conditions, as can be concluded from analysis of the mass spectra of a variety of substances.

Amino Acid Sequence↗
PubMed1979

Side effects of diphtheria-tetanus toxoid in adults.

During a mass diphtheria-tetanus immunization campaign in November 1975, more than 220,000 doses of diphtheria-tetanus toxoid, adult type were administered to adults throughout Alaska. In Anchorage, where more than 87,000 doses were given, a survey was conducted to determine the frequency of side effects. Postcard questionnaires were mailed to 2,000 randomly selected Anchorage residents; 467 questionnaires were returned by the post office as undeliverable, and 697 questionnaires were completed and returned. A follow-up survey was done of a random sample of the 836 non-responders. Of those responding, 57.8 per cent reported at least one reaction to the toxoids. The most frequent side effects were sore arm (42.7 per cent), swelling at the site of injection (34.8 per cent), and itching (24.2 per cent). Serious side effects occurred less frequently-swelling of the arm below the elbow (1.1 per cent) and abscess or infection (0.7 per cent). Of those vaccinated, 0.5 per cent saw a physician. There were no statistically significant differences in reaction rates by age group, except for sore arms. The jet injector produced more arm swelling at the site of injection, hives, and itching. More women than men reported adverse reactions, especially sore arm, swelling at the site of injection, and itching. Fear of adverse side effects should not preclude mass vaccination of adults. (Am. J. Public Health (69:246-249,1979.)

Adult↗
PubMed2002

Ionisation clusters at DNA level: experimental modelling.

The importance of initial clustered damage to DNA is a hypothesis, which has to be approached also from physical modelling of the initial products of single charged particle interaction with DNA. A new tool for such studies, presented here, is based on modelling of the ionisation patterns resulting from a single charged particle crossing a nitrogen cavity of nanometre size. The nanometre size sites equivalent in unit density to DNA and nucleosome, have been modelled in a device, called a Jet Counter, consisting of a pulse operated valve which injects nitrogen in the form of an expansion jet into an interaction chamber. The distributions of the number of ions in a cluster created by a single alpha particle of 4.6 MeV along 0.15 nm to 13 nm size in nitrogen have been measured. A new descriptor of radiation action at DNA level is proposed.

DNA↗
PubMed2002

The track structure of alpha-particles from the point of view of ionization-cluster formation in "nanometric" volumes of nitrogen.

Probability distributions of the size of ion clusters created in "nanometric" volumes of nitrogen by single alpha-particles of a gold-plated 241Am source, were measured and compared with those calculated by Monte Carlo methods in the same geometry. The diameter of the sensitive volumes had a mass per area of between 0.015 microgram/cm2 and 1.3 micrograms/cm2 which, for a material at unit density, corresponds to a nanometric target volume 0.15-13 nm in diameter. These nanometre sizes were simulated experimentally in a device called the Jet Counter. This consists of a pulse-operated valve which injects into an interaction chamber an expansion jet of molecular nitrogen gas, which is crossed by a narrow beam of alpha-particles. The resulting ions are counted and analyzed from the point of view of ionization cluster formation. The measured or calculated cluster size probabilities prove that the formation of ionization clusters along a "nanometre" track is governed by Poisson's law only in the case of very small target volumes, due to the contributions by secondary electrons. The present ionization cluster probabilities produced in "nanometric" volumes 0.15-13 nm in diameter, are the first ever determined experimentally and confirmed by Monte Carlo simulation.

Alpha Particles↗
PubMed1990

A solution to the problem of high-flow jets from miniature angiographic catheters.

In this study we evaluated methods for reducing high-flow jets from 5-French catheters that occur when injection pressures approach catheter tolerance (1000 psi [6.9 MPa]). This "jet effect" has been responsible for subintimal extravasation of contrast material in patients. We designed a physical model that accurately measures flow rates through the end hole and each side hole of 5-French high-flow catheters under simulated physiologic arterial pressure. When a standard catheter commonly used for injection of contrast material was studied, flow of contrast material was 34% through the end hole and 31% through the distal side-hole pair at high injection pressures (1000 psi). We examined the effect of altering the size and configuration of catheter side holes and end hole in an effort to create an improved flow profile, and thus a safer angiographic catheter. End-hole flow rate was reduced by 73% to 9% of total flow by tapering the 5-French catheter to 0.018 in. (0.046 cm) and by using smaller 0.015-in. (0.038-cm) side holes for even flow distribution. The high-flow jets present with standard high-flow 5-French catheters do not occur when flow-restrictive end holes and side holes are used. A uniform flow profile can be obtained without sacrificing delivery of contrast material through small catheters.

Angiography↗