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PubMed2006

X-ray spectroscopy of 1 cm plasma channels produced by self-guided pulse propagation in elongated cluster jets.

We diagnose the self-channeled propagation of intense femtosecond pulses over an extended distance in a N2O cluster gas target using high resolution kilovolt x-ray pinhole images of the channel and spatially resolved x-ray spectra. The x-ray images are consistent with femtosecond optical scattering, shadowgraphy, and interferometry images. We observe extended plasma channels (approximately 9 mm) limited either by the cluster jet length or by absorption, for injected laser intensities in the range of 10(16)-10(17) W/cm2. Spectral line shapes for the OVII 1s2-1s3p and OVIII 1s-2p transitions (at 1.8627 and 1.8969 nm, respectively) show significant broadening to the blue side and with truncated emission on the red side. We attribute this effect to Doppler blueshifted emission from fast ions from exploding clusters moving toward the spectrometer; redshifted emission from the opposite side of the cluster is absorbed.

Journal Article↗
PubMed1982

A heat and humidification system for high frequency jet ventilation.

The clinical application of high frequency jet ventilation (HFJV), especially in pediatrics, has been hindered by the lack of adequate heating and humidification of the delivered gas. A technique of injecting particulate water into the gas from the jet ventilator has been described in the literature. However, it has been used primarily on adults and may cause fluid overload or hypothermia when used on infants. We describe a device for use during HFJV that provides gas (free of particulate water) to the patient at or near body temperature, with a relative humidity of 91%. This system has been used on 34 persons (14 premature infants, 17 small children, and 3 adults) without complications associated with improper conditioning of inspired gas.

Adult↗
PubMedDate not supplied

Air entrainment during high-frequency jet-ventilation. Simulation of a bronchoscopy with a lung model.

Air entrainment contribution to jet-ventilation during bronchoscopy was evaluated as a lung model (increasing compliance and airway resistance). Ventilation was provided through a 10 mm internal diameter tube using either jet alone without air entrainment, or injection with air entrainment (coaxial and lateral injectors). Three I/E ratios (0.25, 0.43 and 0.67) and nine rates of ventilation, ranging from 20 to 300 c X min-1, were assessed. The driving pressure of the injected air was 350 +/- 10 kPa. Air entrainment is an important part of total ventilation (63.7 +/- 5.5%). The magnitude of air entrainment depends upon the levels of peak and end expiratory airway pressures. Increase in lung volume varies linearly with the end expiratory pressure. Air entrainment contributes to keep the tidal volume above the model dead-space. CO2 elimination is related to the magnitude of ventilated volumes. The amount of entrained air interferes with the FIO2 of delivered gases. During bronchoscopy, lateral injection should be preferred because of smaller airway pressures (- 31.2 +/- 0.6%) and lung volumes, while tidal volumes remain adequate.

Airway Resistance↗
PubMed1998

[Anesthetic management for microlaryngeal surgery with high frequency jet ventilation and intravenous application of pentazocine and propofol].

Microlaryngeal surgery was performed with total intravenous anesthesia using pentazocine and propofol in 20 patients. The patients were paralyzed by suxamethonium infusion and ventilated by high frequency jet ventilation via the laryngoscope. In place of the opioid analgesics commonly used in TIVA for microlaryngeal surgery, pentazocine was given. All but one of the patients received pentazocine 15 m.g. intramuscularly as a premedication and then another 15 m.g. intravenously for induction of anesthesia. Average time of surgeries was 33.6 minutes. Average doses of pentazocine and suxamethonium given during surgeries were 369 m.g. and 286 m.g., respectively. This technique allowed stable anesthesia to be achieved with rapid postoperative recovery, without serious complications like intraoperative return of awareness.

Adjuvants, Anesthesia↗
PubMed1994

Mechanical and electromechanical properties of the stereovillar bundles of isolated and cultured hair cells of the chicken.

Isolated single chicken hair cells and pieces of epithelium without the tectorial membrane, either freshly isolated or in tissue culture, were studied using water-jet stimulation of their stereovillar bundles and current injection. Responses were measured under enhanced video-microscopic observation or while using a differential photodiode technique sensitive down into the nanometer range. When stimulated with a water jet at low displacement amplitudes up to about 200 nm, the stereovillar bundle displacement was asymmetrical, indicating a lower stiffness in the excitatory direction, but the reverse was true at higher displacement amplitudes. Undamaged bundles showed no mechanical resonances below 1 kHz. In damaged bundles, however, such resonances were prominent and accompanied by splaying of the stereovilli. Hair cells in the epithelium showed small bundle movements (0.6 nm/mV) whose polarity depended on the polarity of the injected current. These movements probably resulted from activation of the bundle's adaptation motors.

Animals↗
PubMed1997

Growth hormone treatment without a needle using the Preci-Jet 50 transjector.

A new delivery system (Preci-Jet 50) which administers growth hormone through the skin using high pressure and without a needle was evaluated. This device was inconvenient and painful compared with a pen injection system. The conclusion is that the Preci-Jet is not the panacea for solving the problem of compliance with subcutaneous growth hormone injections.

Administration, Cutaneous↗
PubMed1997

A clinical, epidemiological and laboratory study on avoiding the risk of transmitting viral hepatitis during vaccinations with the Dermojet protected by an anticontaminant disposable device.

Jet injectors may transmit blood-borne infections, such as hepatitis B virus (HBV) and human immunodeficiency virus (HIV). To evaluate the safety of an anticontaminant disposable device which protects the jet injector apparatus, 22,714 healthy subjects were intradermally inoculated (38,162 inoculations) with a variety of vaccines. All the subjects were systematically followed-up clinically and epidemiologically for 6-18 months after inoculation; blood samples from 1619 subjects, before and 60-75 days after inoculation, were examined by enzyme-linked immunosorbent assay (ELISA) for HBV, hepatitis C virus (HCV) and HIV. Before vaccination 212 (13.09%) subjects were positive: 204 positive for HBV markers and eight for the HCV marker. None of the subjects were positive for the anti-HIV marker. During the clinico-epidemiological surveillance and the laboratory investigations mentioned above no clinical viral hepatitis B or C case and no seroconversion to positivity for HBV or HCV markers among the susceptible persons in the group were reported. Considering that in similar situations there is a theoretical risk of transmission as high as 1 per 388 to 1 per 3367 injections and that in our case 38,162 inoculations were performed in 22,714 subjects with the same Dermojet protected by the same type of anticontaminant disposable device, no contamination risk being reported, the conclusion can be reached that jet injectors can be safely used in the medical practice if they are protected by the sterile anticontaminant disposable device.

Adolescent↗
PubMed1999

Usefulness of newly designed pigtail catheter with multiple side holes by reducing incidence of ventricular ectopy.

This study was designed to determine whether a newly designed 5 Fr pigtail catheter of Jet Balance with multiple side holes reduces the incidence of ventricular ectopy during left ventriculography. To examine the catheter movement in vitro, we injected a colored glycerin solution by an injector through 5 Fr Jet Balance catheter and 6 Fr conventional pigtail catheter suspended in a water filled, glass container. A recoil of the catheter caused by injection was observed for a 6 Fr conventional catheter; however, no catheter movement was observed when a 5 Fr Jet Balance was used. To evaluate clinical usefulness of the 5 Fr Jet Balance, we compared the number of incidence of ventricular ectopy during left ventriculography between 5 Fr Jet Balance and 6 Fr conventional pigtail catheters. In 104 consecutive patients who underwent left ventriculography, a 5 Fr Jet Balance was used in 55 patients (5 Fr Jet Balance group), and a 6 Fr conventional pigtail in 49 patients (6 Fr conventional pigtail group). The 5 Fr Jet Balance group had a significantly lower incidence of VPB (21.8% vs. 42.9%, P = 0.02), ventricular tachycardia (1.9% vs. 14.3%, P = 0.02), and multiple VPB (9.0% vs. 34.7%, P = 0.001), respectively, than the 6 Fr conventional pigtail group. In conclusion, a 5 Fr Jet Balance pigtail catheter is useful and safe as regard to the incidence of ventricular ectopy during left ventriculography. Cathet. Cardiovasc. Intervent. 48:220-225, 1999.

Aged↗
PubMed1999

Transdermal and transmucosal powdered drug delivery.

High-velocity powder injection is a promising new drug-delivery technique that provides needle- and pain-free delivery of traditional drugs, drugs from biotechnology such as proteins, peptides, and oligonucleotides as well as traditional and genetic vaccines. The energy of a transient helium gas jet accelerates fine drug particles of 20 microns-100 microns diameter to high velocities and delivers them into skin or mucosal sites. This review describes the configuration and operating principles of devices that accelerate the particles, the required properties of the particles, the characteristics of the target tissues, and features of the developmental test methods. Preclinical and clinical results that best characterize the technology and introduce its potential as a drug-delivery platform are presented.

Administration, Cutaneous↗
PubMed2006

Tempol in the dorsomedial hypothalamus attenuates the hypertensive response to stress in rabbits.

BACKGROUND: We have recently shown that microinjection of the superoxide dismutase mimetic tempol into the pressor region of the rostral ventrolateral medulla attenuates the cardiovascular response to mental (air-jet) stress in rabbits. In the present study, we examined the influence of tempol on the blood pressure (BP) and heart rate (HR) responses to stress in the key region of the hypothalamic defense area, the dorsomedial hypothalamus (DMH). METHODS: New Zealand White rabbits were implanted with guide cannulae for microinjection into the DMH. After 2 weeks of recovery, the cardiovascular response to air-jet stress was evaluated before and after bilateral injections of equimolar doses (20 nmol) of the superoxide scavengers tempol, tiron, or 3-carbamoyl proxyl (3-CP). RESULTS: Microinjection of superoxide scavengers into the DMH did not alter resting BP or HR. Air-jet stress evoked a sustained increase in BP (+16 +/- 2 mm Hg) and HR (+48 +/- 5 beats/min). Tempol attenuated the pressor and tachycardic responses to air-jet stress by 39% +/- 10% and 37% +/- 8%, respectively (P < .05), without altering stress-induced tachypnea. Similarly, tiron selectively decreased the BP and HR responses to stress by 33% +/- 8% and 53% +/- 13%, respectively (P < .05). Conversely, 3-CP, which is structurally close to tempol but has a lower superoxide scavenging activity, did not alter the cardiovascular stress response, and neither did vehicle. Microinjection of tempol or tiron just outside the DMH had little effect on stress responses. CONCLUSIONS: This study provides first published evidence that superoxide in the DMH is important in the regulation of acute hypertensive and tachycardic responses to mental stress.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗
PubMed2006

Needle-free injection of DNA vaccines: a brief overview and methodology.

The development of needle-free injection originally stemmed from a general apprehension of needle injections, disease transmission by accidental needle-sticks, and the need for effective mass immunization. Naked DNA vaccines, as attractive and universal as they appear, have not produced robust immune responses in test systems. However, proof of principle for DNA vaccines has been validated with a number of vaccine candidates in a variety of test systems, and the concept of DNA vaccines as a generic platform for vaccines still remains viable and attractive. Many avenues are being explored to enhance the immunogenicity of DNA vaccines. The easiest and most straightforward approach that can be quickly transitioned to a clinical trial setting is vaccine delivery by a needle-free jet injector. This approach has shown much potential in a number of cases and should become the lead method for enhancing DNA vaccines. This approach requires no additional development, and with an expanding market and willingness from jet injector manufacturers to produce prefilled syringes, the technique should become feasible for larger phase II/phase III trials.

Animals↗
PubMed2006

[Development of new surgical tools, Q-PAL and HP-Jet for endoscopy only used unilateral transnasal approach for pituitary adenomas].

UNLABELLED: The aim of this study is to present surgical techniques and results of endoscope-assisted transnasal approach (TNA) for pituitary adenomas. It is a new alternative for Hardy's surgery (TSS). We performed TNA assisted by only endoscope through single nostril. METHOD: We enter the sphenoid sinus directly through the natural ostium and ablate neither the nasal septum nor the vomer bone. We found the hardest problem of this method resides in its deep and narrow working space which obstructs usage of two tools at same time. To overcome this problem we developed two surgical tools, Q-PAL and HP-Jet. Q-PAL is combination of PAL and suction. We place flexible PAL wire electrode through suction tube so as PAL tip protrudes from suction tip. This eliminates coagulation smoke which otherwise disturbs surgeons view. HP-Jet is a combination of a suction tool and an irrigator. The irrigator is connected to syringe containing saline. Saline is injected manually from tip bursting up tumor tissue with its jet pressure. It is safe and effective instrument suitable for extirpation of rather fragile tissue like adenomas existing in deep and blind spaces. CASES: Since 2004 we have operated on 16 patients using endoscopic TNA. Eight were non-functioning adenomas, and 8 functioning. RESULTS: Results of surgery were compared with those of 10 cases operated by TSS. More than 70% removal of adenoma was achieved in 75% of cases with TNA, but in only 71% with TSS. Postoperative CSF rhinorrhea was seen in one case. Four cases showed postsurgical transient diabetes insipidus. We had no case with postsurgical infection. With the help of instruments having multiple functions in single probe such as Q-PAL and HP-Jet, we can execute endoscopic TNA more smoothly and more safely.

Adenoma↗
PubMed1997

Midazolam-flumazenil topical anaesthesia for microlaryngoscopy with jet ventilation.

A comparison between midazolam and midazolam-flumazenil for total intravenous anaesthesia in combination with topical anaesthesia and muscle relaxants was performed in a double-blind, parallel study in 40 patients scheduled for microlaryngoscopy with or without bronchoscopic procedures using jet ventilation with oxygen. A single intravenous injection of midazolam 0.3 mg/kg, lignocaine spray and muscle relaxants provided adequate anaesthesia and good operative conditions throughout the procedures, which took 20 to 30 minutes. Patients who had placebo at the end of the procedures had a longer recovery and a high incidence of airway obstruction (20%). Administration of flumazenil provided prompt awakening in 19 of 20 patients (95%) within five minutes, resulting in rapid and favourable recovery without resedation or other side-effects, while only three of 20 (15%) patients in the placebo-treated group had improved consciousness within five minutes. The simplicity and reliability of the midazolam-flumazenil technique is attractive. We consider it worthy of further investigation for wider application in clinical practice.

Adolescent↗
PubMed2006

High-pressure injection injuries to the upper extremity: a review of the literature.

OBJECTIVES: The purpose of this review was to identify the relative impact of injected material, location of injury, time to debridement, injection pressure, infection, and the use of adjuvant steroid medication upon the need for amputation after high-pressure injection injuries to the upper extremity. DATA SOURCES AND STUDY SELECTION: A Medline literature search extending from 1966 to December 2003 was performed, referencing the key words "high-pressure injection injury," "grease gun injury," "paint gun injury," "pressure gun injury," and "high-pressure injection." The results were limited to the English language and to reports involving human subjects. Each abstract was reviewed to confirm that the described injury had occurred in the upper extremity and that it had truly been a high-pressure injection. The reference pages from each of the papers were reviewed to identify additional reports of high-pressure injection injury. Manuscripts describing injuries resulting from hand held syringes or other low-pressure mechanisms were excluded. DATA EXTRACTION: All of the manuscripts were analyzed to identify the clinical outcome, age, hand dominance, site of injection, substance injected, injection pressure, elapsed time to wide debridement, use of steroids, and incidence of infection. These variables were subjected to a Pearson chi test to determine their impact upon the need for amputation. RESULTS: Four hundred thirty-five cases of high-pressure injection injury to the upper extremity were identified. The amputation rate after these injuries was 30%. The location of the injury and the material injected contributed significantly to the need for amputation. For injections of paint, paint thinner, gasoline, oil, or jet fuel (organic solvents), the amputation risk was lower if wide surgical debridement occurred within 6 hours of injury. Steroids did not impact the amputation rate or incidence of infection. The presence of infection did not affect the incidence of amputation. CONCLUSIONS: The risk of amputation after high-pressure injection injury to the upper extremity is highest with organic solvent injection into the fingers. Injections into the thumb or palm result in a much lower frequency of tissue loss. Emergent surgical debridement reduces the amputation risk after injections of organic solvents. From the available data, no conclusions could be reached regarding functional outcomes, other than amputation, after high-pressure injection injury.

Forearm Injuries↗
PubMed1978

Cardiac trauma from angiographic injections. A quantitative study.

To relate angiographic injections to potential cardiac trauma, we verified a mathematic theory that allows quantitative definition of the kinetic energy content of contrast jets emanating from the exit holes of angiographic catheters. Cineangiographic recordings of a range of jets of known energy content were obtained in 18 cardiac canine experiments and energy content and dissipation were quantified precisely from center line to jet edge. All contrast jets produced in clinical angiographic practice were turbulent, even those from hand injections into the coronary arteries. Energy content was related to an estimated cardiac wall damage threshold. At energy levels and damage thresholds predicted by the theory and computations, a traumatic spectrum was found by cineradiology and microscopic examination. A unique curve independent of jet Reynolds number was discovered relating the penetration of the contrast jet into the intravascular blood to the potential for cardiac trauma. This curve allowed ready calculation of hydraulic energy dissipation for any clinically used angiographic catheter and the definition of safe operational injection flow rates. Thus potential cardiac trauma can be anticipated and prevented.

Angiography↗
PubMed1996

Determination of salicylate in beverages and cosmetics by use of an amperometric biosensor.

A fast and selective enzymatic method for the determination of salicylate in beverages and cosmetics has been developed. The enzyme salicylate hydroxylase was immobilised covalently onto a glassy carbon working electrode of a wall-jet cell coupled with a flow-injection analysis system. The salicylate is enzymatically converted to catechol, which can be detected amperometrically on the glassy carbon electrode at +0.45 V. The response of the biosensor is linearly proportional to the concentration of salicylate between 725 nmol/l and 700 micromol/l. A high sample throughput (60 h(-1)) is possible, and the biosensor is stable for more than three months. Sample pretreatment for beverages and hair lotions is easy and fast. For creams, an extraction of salicylate is necessary. Relative standard deviations are less than 5.5% and the recoveries are between 95 and 105%.

Journal Article↗
PubMed2005

Engineering of needle-free physical methods to target epidermal cells for DNA vaccination.

A challenge in epidermal DNA vaccination is the efficient and targeted delivery of polynucleotides to immunologically sensitive Langerhans cells. This paper investigates this particular challenge for physical delivery approaches. The skin immunology and material properties are examined in the context of the physical cell targeting requirements of the viable epidermis. Selected current physical cell targeting technologies engineered to meet these needs are examined: needle and syringe; diffusion patches; liquid jet injectors; microneedle arrays/patches; and biolistic particle injection. The operating methods and relative performance of these approaches are discussed, with a comment on potential future developments and technologies.

Biolistics↗
PubMed1999

The effect of a neuropeptide Y antagonist, BIBP 3226, on short-term arterial pressure control in conscious unrestrained rats with congestive heart failure.

The effects of a neuropeptide Y (NPY) Y1-receptor antagonist (BIBP 3226) on mean arterial pressure (MAP) and heart rate were investigated in conscious unrestrained rats with chronic congestive heart failure. The rats were randomly assigned to 2 groups, and received either BIBP 3226 or its inactive enantiomer (BIBP 3435) as an intravenous infusion (6 mg/kg/h for 1.5 h, respectively). Before, during and after the infusion, rats were stressed with a jet of air and received a bolus injection of NPY (2 nmol/kg iv.). There was no difference between the 2 groups in resting MAP and heart rate before, during or after infusion (BIBP 3226 vs. BIBP 3435). The effects of exogenous NPY on MAP were significantly attenuated in BIBP 3226 group during and 1 h after the infusion (p<0.05). The tissue NPY levels in heart, adrenal gland and kidney in heart failure rats were not different from those in sham-operated rats. The results suggest that Y1-receptor mechanisms are of minor importance in the short-term control of basal MAP and heart rate in conscious unrestrained rats with congestive heart failure.

Animals↗