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PubMed2003

Comprehensive two-dimensional gas chromatography using large sample volume injection for the determination of polynuclear aromatic hydrocarbons in complex matrices.

The sensitivity of a gas chromatography (GC) analytical method can be substantially enhanced by injecting large sample volumes. The novel Large Volume Splitless injection technique was used in combination with comprehensive two-dimensional GC (GC x GC), taking advantage of the improved detectability and the very high separation capability. An experimental version of Thermo Electron TRACE GC Ultra using a cryogenic dual jet modulator was utilized with a fast flame ionization detector (FID) for the analysis of low ppbs level of PAHs compounds in very complex matrices. Experimental data (relative standard deviation of 1% evaluated on a standard mixture) demonstrate the reliability of the whole system. A dedicated data system is presented for acquiring and managing GC x GC data: three-dimensional and color plot visualization, peaks integration, identification and quantitation are functions available with the software.

Chromatography, Gas↗
PubMed1987

Fluid particle motion and Lagrangian velocities for pulsatile flow through a femoral artery branch model.

A flow visualization study using selective dye injection and frame by frame analysis of a movie provided qualitative and quantitative data on the motion of marked fluid particles in a 60 degree artery branch model for simulation of physiological femoral artery flow. Physical flow features observed included jetting of the branch flow into the main lumen during the brief reverse flow period, flow separation along the main lumen wall during the near zero flow phase of diastole when the core flow was in the downstream direction, and inference of flow separation conditions along the wall opposite the branch later in systole at higher branch flow ratios. There were many similarities between dye particle motions in pulsatile flow and the comparative steady flow observations.

Adult↗
PubMed2004

Resource guide 2004. Insulin delivery.

Syringes...pumps...jet infectors...pens...infusers...they all do the same basic thing--deliver insulin. These items carry insulin through the outermost layer of skin and into fatty tissue so it can be used by the body. This section will also cover injection aids, products designed to make infecting easier.

Diabetes Mellitus↗
PubMed2005

American Diabetes Association. Resource guide 2005. Insulin delivery.

Syringes...pumps...jet injectors...pens...infusers...they all do the same basic thing--deliver insulin. These items carry insulin through the outermost layer of skin and into fatty tissue so it can be used by the body. This section will also cover injection aids, products design to make injecting easier.

Catalogs, Commercial as Topic↗
PubMed2004

Technologies that make administration of vaccines safer.

There is an ever-expanding technology that is aimed at making the administration of vaccines safer. Conventional ways of administering vaccines are being upgraded, modified or replaced by a wide variety of innovations. The paradigm of liquid vaccines, needles and syringes is slow to change, but already developments are occurring that will change for ever the way vaccines are administered and will improve the safety record of immunization. The oral route of vaccine administration has generally been thought of as safe, but until now only the polio vaccine has been widely used in this way. The conventional method of vaccine administration is by injection. Many ingenious devices have become available that now make injecting safer. Inventors are now looking imaginatively to alternative routes and technologies for delivering vaccines. Vaccines are generally manufactured to extremely high standards and rarely are shown to be the cause of safety issues. People remain the weakest safety link is vaccine administration. Technologies that bypasses the ability of man to make bad decisions or to behave incorrectly are of tremendous value. The vaccine world is in the middle of a radical re-think about how vaccines might best be administered. The presentation of the vaccine can be altered to fit new technologies such as powder jet guns, or skin patches. Even the conventional needle and syringe have evolved to much safer versions, and are set to continue this evolution. All this means even safer vaccines and their delivery.

Drug Compounding↗
PubMed2000

Flow injection analysis of cholic acids in pharmaceutical preparations using a polymeric membrane ISE as detector.

The results reported in this paper regard the setting up of a polymeric membrane ISE that is selective for cholic acids (CA) and able to work in a flow system, especially in flow injection analysis (FIA), based on the exchanger (tetrakisdecylammoniumcholate, TDACh), which has proved effective, is of very simple but suitable structure and is above all easy to synthesise starting from commercially available chemicals. A complete analytical characterisation of the sensor was performed working both in batch conditions and in FIA, using in the latter case a 'wall jet' type of flow cell. The response toward different bile acid sodium salts such as the CA, deoxycholic (DCA), chenodeoxycholic (CDCA), ursodeoxycholic (UDCA), taurocholic (TCA) sodium salts was checked. The application to the analysis of different commercial drugs by FIA was also performed to determine the UDCA or CDCA acid content of several pharmaceutical formulations. Lastly, a preliminary study is presented concerning the use of the investigated electrochemical sensor as high performance liquid chromatography (HPLC) detector.

Cholic Acids↗
PubMed1985

Venous contrast extravasation during digital subtraction angiography.

Six episodes of contrast extravasation occurred in 5 patients during intravenous digital subtraction angiography in a period of 9 months. The extravasations were into the mediastinum (3), pericardium (1), and right atrial wall (2). These occurred using a variety of catheters, all the same size (5.0 F--1.67 mm). Three were Katzen catheters, one had a pigtail configuration, and two were straight catheters. We believe that the extravasations are due to three main factors. The first is catheter-related, owing to the small size (5.0 F) creating recoil and marked jet stream effect due to the large volume and pressure that must be delivered through the side holes. The second factor is related to positioning of the catheter in the superior vena cava. Finally, the respiratory phase at the time of injection becomes crucial. Understanding of these factors may help to decrease this potentially serious complication.

Adult↗
PubMed1993

Simultaneous determination of ammonia nitrogen and L-glutamine in bioreactor media using flow injection.

A novel split stream flow injection (FI) system suitable for the simultaneous determination of L-glutamine and ammonia nitrogen (ammonia-N) in cell culture media is described. Potentiometric detection of ammonia-N in one portion of the manifold is achieved using a commercial ammonia gas-sensing electrode fitted with a wall-jet cap. L-Glutamine is quantified in the other part of the split sample by potentiometric detection of ammonium ions (by an ammonium-selective polymer membrane electrode), liberated from the hydrolysis of glutamine after the sample flows through a glass bead reactor containing immobilized glutaminase. Endogenous ammonia-N and potassium ions that would normally interfere with the glutamine measurement are removed upstream using a unique tubular cation-exchange unit. Using 50 microliters sample volumes and mixed solutions of ammonium chloride and L-glutamine in Iscove's Modified Dulbecco's Medium to calibrate the FI measuring system, values for ammonia-N and L-glutamine determined for 22 media samples obtained from a bioreactor growing retroviral producer cells correlate well with those measured with commercial, manual enzymic-spectrophotometric assay kits.

Ammonia↗
PubMed1999

Ouabain- and central sodium-induced hypertension depend on the ventral anteroventral third ventricle region.

To examine the role of the ventral anteroventral third ventricle (vAV3V) in the hypertension induced by chronic subcutaneous ouabain and intracerebroventricular hypertonic saline, neurons in this area were destroyed by microinjection of an excitotoxin, ibotenic acid. Sham-operated or lesioned Wistar rats were administered ouabain (50 microgram/day) or placebo for 3 wk from subcutaneously implanted controlled release pellets or artificial cerebrospinal fluid (CSF) or CSF containing 0.8 mol/l NaCl (5 microliter/h) infused intracerebroventricularly for 2 wk. At the end of the experiment, mean arterial pressure (MAP) and heart rate at rest and in response to ganglionic blockade by intravenous hexamethonium (30 mg/kg) were assessed. In rats infused with hypertonic saline, responses to air jet stress were also assessed. Baseline MAP in sham-operated rats receiving intracerebroventricular hypertonic saline or subcutaneous ouabain was significantly higher than in control rats (115 +/- 1 vs. 97 +/- 3 and 121 +/- 3 vs. 103 +/- 3 mmHg, respectively). vAV3V lesions abolished the increase in MAP elicited by chronic infusion of hypertonic saline or administration of ouabain. Sham-operated rats treated with hypertonic saline or ouabain exhibited significantly enhanced decreases in MAP to hexamethonium, but lesioned rats did not. Rats infused with hypertonic saline demonstrated enhanced responses to air jet stress that were similar in sham-operated and lesioned rats. These results demonstrate that neurons in the vAV3V are essential for the hypertension induced by intracerebroventricular hypertonic saline and subcutaneous ouabain, possibly by increasing sympathetic tone. Cardiovascular responses to air jet stress appear not to be mediated by the vAV3V.

Animals↗
PubMed2000

Plasmid DNA vaccines: tissue distribution and effects of DNA sequence, adjuvants and delivery method on integration into host DNA.

A variety of factors could affect the frequency of integration of plasmid DNA vaccines into host cellular DNA, including DNA sequences within the plasmid, the expressed gene product (antigen), the formulation, delivery method, route of administration, and the type of cells exposed to the plasmid. In this report, we examined the tissue distribution and potential integration of plasmid DNA vaccines following intramuscular administration in mice and guinea pigs. We compared needle versus Biojector (needleless jet) delivery, examined the effect of aluminum phosphate adjuvants, compared the results of different plasmid DNA vaccines, and tested a gene (the human papilloma virus E7 gene) whose protein product is known to increase integration frequency in vitro. Six weeks following intramuscular injection, the vast majority of the plasmid was detected in the muscle and skin near the injection site; lower levels of plasmid were also detected in the draining lymph nodes. At early time points (1-7 days) after injection, a low level of systemic exposure could be detected. Occasionally, plasmid was detected in gonads, but it dissipated rapidly and was extrachromosomal - indicating a low risk of germline transmission. Aluminum phosphate adjuvant had no effect on the tissue distribution and did not result in a detectable increase in integration frequency. Biojector delivery, compared with needle injection, greatly increased the uptake of plasmid (particularly in skin at the injection site), but did not result in a detectable increase in integration frequency. Finally, injection of a plasmid DNA vaccine containing the human papilloma virus type 16 E7 gene, known to increase integration in vitro, did not result in detectable integration in mice. These results suggest that the risk of integration following intramuscular injection of plasmid DNA is low under a variety of experimental conditions.

Adjuvants, Immunologic↗
PubMed1986

Hypothalamic beta 2-adrenoceptor control of renal sympathetic nerve activity and urinary sodium excretion in conscious, spontaneously hypertensive rats.

The contributions of beta 1-, B2-, and alpha 2-adrenoceptors in the posterior hypothalamus to the increased renal sympathetic nerve activity and decreased urinary sodium excretion resulting from environmental stress (air jet) in conscious spontaneously hypertensive rats were examined. Air stress increased mean arterial pressure and renal sympathetic nerve activity (54% from 7.0 +/- 0.7 integrator resets/min), and decreased urinary sodium excretion (44% from 2.7 +/- 0.4 microEq/min per 100 g body weight). After bilateral injection of ICI 118,551 (beta 2-adrenoceptor antagonist) into the posterior hypothalamus of the same spontaneously hypertensive rats, air stress had no effect on renal sympathetic nerve activity (8% from 4.8 +/- 0.7 integrator resets/min) or urinary sodium excretion (2% from 5.2 +/- 0.8 microEq/min per 100 g body weight), but still increased mean arterial pressure. Bilateral injection of isoproterenolol (beta-adrenoceptor agonist) into the posterior hypothalamus enhanced the renal sympathetic nerve activity and urinary sodium excretion (but not mean arterial pressure) responses to air stress. Air stress had no effect on renal sympathetic nerve activity or urinary sodium excretion when ICI 118,551 was given into the posterior hypothalamus before isoproterenol. Atenolol (beta 1-adrenoceptor antagonist) had no effect on the renal responses to air stress when given alone or before isoproterenol. Similarly, ICI 118,551 administered into the lateral hypothalamus or lateral cerebral ventricle, or guanabenz (alpha 2-adrenoceptor agonist) given into the posterior hypothalamus, had no effects on the renal or mean arterial pressure responses to air stress. Thus, beta 2-adrenoceptors in the posterior hypothalamus mediate the increased renal sympathetic nerve activity and antinatriuresis resulting from environmental stress in conscious spontaneous hypertensive rats.

Air↗
PubMed2000

[New trends in therapy of diabetes. More freedom, fewer risks, comfortable insulin administration].

The incidence of diabetes mellitus is increasing worldwide. Strict metabolic control can prevent late sequelae of this disease. For this purpose, not only more potent drugs with fewer side effects are needed, but also user-friendly techniques and devices for self-monitoring of blood glucose and the less painful application of insulin (jet application, inhalable insulin). More user-friendly insulins are the rapid- and short-acting human insulin analogues, which do away with the bothersome injection/meal interval, and improve the postprandial glycemic response. New long-acting insulins reduce the frequency of injections and the occurrence of nocturnal hypoglycemia. Type 2 diabetics will presumable benefit from the use of the rapid, short-acting glinides, for example, by enabling a greater measure of eating freedom during the course of the day. The thiazolidinediones, a group of agents that enhance the effects of insulin in target tissue, reduce insulin resistance and improve insulin sensitivity.

Diabetes Mellitus↗
PubMedDate not supplied

[An evaluation of orthotopic ileal neobladders by dynamic digital urography].

PURPOSE: To report on the diagnostic capabilities of dynamic digital urography in the evaluation of orthotopic ileal neobladders. MATERIAL AND METHODS: Ten male patients (aged 61.3 +/- 14.7 years) with orthotopic ileal neobladder (4 Studer, 4 Camey type II with spiralized ileal segment and 2 classic Camey type II) underwent dynamic digital urography using an angiographic unit (Philips DVI/ARC-A). Eight patients were asymptomatic and two presented mild nycturia. All patients should have undergone follow-up conventional urography, which was replaced, for the purposes of our study, by dynamic digital urography. The intestinal cleansing regimen usual for the double contrast barium enema was used in all the patients. Ninety mL of a nonionic iodinated contrast agent were administered i.v. with an automatic injector. After precontrast mask images, two postcontrast sequences were acquired 15 s and 30 min after the injection (each made of 20 images acquired every 10 seconds). Postprocessing consisted of digital image subtraction and videorecording. RESULTS: Renal pelvis and calyceal systems were well visualized in 18/20 excretory systems. Eighteen of 20 ureters were visualized completely up to the ureteral jet, and two were only partially visualized. Calyceal, pyelic and ureteral enlargement with ureteral kinking were observed in a patient with classic Camey type II. High motility was seen in 11 ureters, moderate in 5 and mild in 4. The orthotopic ileal neobladder was well opacified in 8/10 patients. Effective peristalsis of the afferent ileal segment was seen in all the Studer type neobladders. Ureteral reflux was not observed in any patient. DISCUSSION: After orthotopic ileal neobladder reconstruction, the most frequent complications include urinary leakage, intestinal obstruction, venous thrombosis, stenosis of the neobladder anastomoses, incontinence, cancer recurrence, stone formation. In the follow-up, many diagnostic tools are used: intravenous urography, retrograde cystography, urodynamic studies, transabdominal and transrectal ultrasonography. With dynamic digital urography the nephrographic evaluation was possible in all patients, as well as the evaluation of calyceal, pyelic and ureteral opacification and even ureteral peristalsis. Moreover, this diagnostic tool allows the morphofunctional dynamic study of the ureteral-neobladder anastomoses and of the orthotopic ileal neobladder, even evaluating the residual peristalsis of the detubularized ileal segment. A major drawback of the new method is the relatively high radiation dose given to the patient. A limitation of the study is the selection of a population of completely or nearly asymptomatic patients. CONCLUSIONS: Dynamic digital urography provides useful morphologic and functional information in the follow-up of patients with orthotopic ileal neobladder and could replace conventional urography in symptomatic patients.

Aged↗
PubMed1993

[Viscosurgically assisted hydro-jet irrigation of the lens nucleus. An effective procedure for extracapsular cataract extraction with capsulorhesis].

BACKGROUND: To reduce costs and to be independent of high technology equipment it is desirable to perform cataract operations of high quality manually. MATERIALS AND METHODS: The manual operation includes a spiral shaped capsulorhexis, hydrodissection of the nucleous and its consequent delamination by means of hydroxypropylmethylcellulose (Metho). A bent cannula is used to create a jet stream of fluid separating the nucleous from the cortex and pressing the nucleous out of the bag. The cannula is connected to an infusion system 80 cm above the patient's eye. The nucleous slips into the anterior chamber and is delivered by injection of Metho, the injection cannula acts as a spatula to facilitate nucleous delivery. The nucleous also can be fragmentated for reduced incision length. The method was combined with an 8 mm tunnel incision. The implanted lenses had 7 mm optics and 10 or 11 mm haptics. In 100 consecutive operations (48 in males and 52 in females respectively) daily clinical examination was carried out for 7 days including the day of operation. Complications occurring during this time were listed. RESULTS: No lesion of the capsule/zonule diaphragm occurred. In 3 cases corneal edema was observed, which disappeared within 5 days totally. In 2 cases a continuous rhexis was not achieved, but the lens was situated in the bag and centered well in these cases as well as in the 98 eyes with intact capsulorhexis. CONCLUSIONS: The method described is safe. Using a purely manual operation technique it is possible to achieve an excellent lens fixation in the bag with undamaged rehexis rim and scleral tunnel incision.

Aged↗
PubMed2002

A new miniature catheter with side-holes for percutaneous transradial or transbrachial coronary angiography.

The percutaneous arm approach through the radial or brachial artery for diagnostic cardiac catheterization has advantages, such as a lower incidence of access-site complications and decreased patient discomfort, particularly when smaller diameter catheters are employed. However, the pressure produced by high-flow jets of contrast material exiting from an end-hole against the vascular wall can cause coronary dissection or myocardial blushing. To avoid this type of complication, we designed and developed a new miniature (4 French) catheter with two side-holes for coronary angiography. Under conditions similar to those of a clinical situation, we obtained the relationship between the pressure produced by the jets exiting from an end-hole and the force with which the tip of the catheter was pushed against the vascular wall. The presence of the side-holes substantially decreased the pressure at forces ranging between 0 and 15 gf, and at all injection rates (2.0 3.5 ml/second), but their location did not affect the pressure. In a preliminary clinical study, the new catheters with side-holes were feasible and effective for coronary angiography through the radial artery. Furthermore, the distribution of contrast material decreased the incidence of dislodgement of the catheter from the coronary ostia and enabled good visualization of the coronary ostia and proximal branches.

Brachial Artery↗
PubMed1990

Measurement of end-expiratory pressure during transtracheal high frequency jet ventilation for laryngoscopy.

An anaesthetic technique using high frequency jet ventilation has been proposed for direct laryngoscopy, but this may expose the patients to the risk of barotrauma. In order to assess this risk, we have measured end-expiratory airway pressure (EEP) through the injector using two three-way solenoid valves mounted in series. At the end of insufflation the first valve was switched off and the apparatus deadspace connected to atmosphere through a large exit port during an adjustable time (decompression time). Then the second valve was switched off and the injection line connected to a transducer, allowing measurement of EEP through the injector. The accuracy of this measurement was tested against airway pressure measured directly in the trachea (Pt) in a lung model. Provided that the decompression time was long enough (70 ms) and the apparatus deadspace was small (6 ml), the difference between EEP and Pt was less than 1 cm H2O for frequencies up to 5 Hz. A clinical evaluation was performed in 64 patients under general anaesthesia before laryngoscopy. EEP correlated with end-expiratory pulmonary volume above apnoeic FRC inferred from abdominal and thoracic displacements. At jet frequencies up to 5 Hz, the correlations between these two variables were satisfactory (r greater than 0.88), suggesting that EEP is a good indicator of pulmonary overdistension.

Barotrauma↗
PubMed1993

Enhancement of mitral regurgitation and normal left atrial color Doppler flow signals with peripheral venous injection of a saccharide-based contrast agent.

OBJECTIVES: The saccharide ultrasound contrast agent SHU 508 A was used to test the hypothesis that an intravenous, transpulmonary contrast method can enhance color Doppler flow signals in the left atrium in a clinically useful manner. BACKGROUND: Color Doppler display of mitral regurgitation may be unreliable because of variable signal to noise ratios that are at times poor. Traditional contrast agents enhance color Doppler flow signals in the right heart chambers. This study describes our observation of a recently developed contrast agent, SHU 508 A, capable of pulmonary transit after peripheral venous injection. METHODS: Control subjects (n = 10) and patients with suspected mitral regurgitation (n = 23) were studied by color Doppler flow imaging before and after 3-g intravenous doses of SHU 508 A. Reference grading of mitral regurgitation (0 to 3) was formulated from left ventricular angiography. In the four-chamber view of the left atrium, we selected for analysis the systolic frame with the maximal retrograde jet of mitral regurgitation (aliased/blue) and the diastolic frame with the maximal color coding from anterograde pulmonary venous flow (red) for planimetry and for grading the intensity of the color Doppler signal (0 to 5). RESULTS: The score of the color Doppler signal intensity increased by > or = 2.5 after 3 g of SHU 508 A (p < 0.001). Flow detection improved, as shown by the increased jet area of mitral regurgitation (> or = 170%), after 3 g of SHU 508 A (3 +/- 3 vs. 12 +/- 8 cm2, p < 0.001) and by a > or = 200% increase in normal anterograde flow area (p < 0.001) in both the mitral regurgitation group and the control group. After contrast enhancement, the correlation between angiographic grading and the relation of jet area to the left atrial area increased from r = 0.79 to r = 0.91. CONCLUSIONS: Contrast-mediated increased echogenicity of the left atrial blood pool improves the signal to noise ratio of Doppler images of mitral regurgitation and anterograde atrial flow. The technique is safe and simple and seems to minimize variability due to instrument design and anatomic signal attenuation.

Adult↗