The redox-active drug metronidazole and thiol-depleting garlic compounds act synergistically in the protist parasite Spironucleus vortens.

Spironucleus vortens is a protozoan parasite associated with significant mortalities in the freshwater angelfish, Pterophyllum scalare. Control of this parasite is especially problematic due to restrictions on the use of the drug of choice, metronidazole (MTZ), on fish farms. Use of garlic (Allium sativum) is undergoing a renaissance following experimental validations of its antimicrobial efficiency. Ajoene ((E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide), is a stable transformation product of allicin, the primary biologically active component of garlic. In the current study, an ajoene oil crude extract had a minimum inhibitory concentration (MIC) of 40µg/ml against S. vortens. GC-MS and NMR spectroscopy revealed this ajoene extract contained a mixture of the (E) and (Z)-ajoene isomers along with diallyl disulphide (DADS) and diallyl trisulphide (DATS). The only component of the ajoene crude oil found to substantially inhibit S. vortens growth by optical density monitoring (Bioscreen C Reader) was (Z)-ajoene (MIC 16µg/ml). Ajoene oil acted in synergy with MTZ in vitro, reducing the individual MIC of this drug (4µg/ml) by 16-fold, and that of ajoene oil by 200-fold with a fractional inhibitory concentration (FIC) index of 0.263. This synergistic interaction was confirmed in vivo. S. vortens-infected Pterophyllum scalare angelfish dosed orally with 0.5% (v/w) MTZ combined with 0.05% (v/w) ajoene displayed a significant reduction in faecal trophozoite count, whilst those fed on 0.5% MTZ flakes (half the recommended oral dose) alone did not. This study demonstrates for the first time the synergistic interaction between the synthetic drug MTZ and natural ajoene oil both in vitro and in vivo. Future work should evaluate the potential synergy of ajoene and MTZ against MTZ-resistant bacteria and protists.

Clinical efficacy and cost-effectiveness of a new synthetic polymer sheet wound dressing.

Stage II and III pressure ulcers present product development and product choice challenges to manufacturers and professional wound care clinicians respectively. We evaluated the clinical performance and cost of use associated with a new synthetic polymer dressing for the management of these wounds. A total of 10 home healthcare patients, each with a Stage II or III pressure ulcer, were enrolled and randomized for wound treatment using either the new polymer hydrogel wound dressing or the leading market hydrocolloid dressing. Dressings were changed on an as needed basis only. The wounds were assessed weekly and parameters recorded using the Bates-Jensen Pressure Sore Status Tool. In addition, the clinical performance of the dressing and treatment costs were evaluated. The overall healing rate for the two groups was similar. However the new polymer hydrogel dressing was found to have a more favorable overall clinical performance evaluation based largely on its more favorable support of autolytic debridement. The new polymeric dressing also had a more favorable cost of use based on the evaluation. We conclude that the new polymer dressing may be a favorable alternative to the leading market hydrocolloid dressing for the treatment of Stage II and III pressure ulcers due to a better clinical performance and the substantially lower treatment costs associated with its use.

Treatment of atherosclerotic ostial renal artery stenosis with the intravascular stent.

Traditional approaches to revascularization for atherosclerotic ostial renal artery stenosis (RAS) have been suboptimal because of the invasiveness and relatively high perioperative morbidity and mortality of surgery and the low rates of success and long-term patency with percutaneous renal angioplasty (PTRA). We report our 5-year (1991 to 1996) experience with the intravascular stent (Palmaz stent; Johnson & Johnson, Miami Lakes, FL) for the treatment of ostial RAS in 129 patients (63 men, 66 women) and 148 arteries. The mean age of the patients was 71+/-10 years; 98% were hypertensive and 57% had renal dysfunction. Angiographic characteristics of RAS were unilateral in 78%, bilateral in 15%, and single kidney in 7%. The technical success rates were 98% for stent versus 11% for PTRA in the ostial location. The stent restenosis rate (angiographic) was 14% at 8+/-5 months. Systolic and diastolic blood pressures were as follows: baseline, 158+/-3 and 84+/-2 mm Hg; 6 months, 149+/-3 and 81+/-2 mm Hg; 12 months, 149+/-3 and 79+/-2 mm Hg; and 24 months, 135+/-3 and 79+/-2 mm Hg. Follow-up values were significantly lower than baseline (P < 0.05). The number of medications for hypertension initially decreased from 2.2+/-0.1 at baseline to 1.6+/-0.1 and 1.8+/-0.1 at 1 and 3 months, respectively (P < 0.05). By 6 months, however, the number of medications had increased and was not significantly different from before stent placement. Renal function was stable in the group as a whole: Cockroft-Gault creatinine clearance (C-G CrCl) at baseline was 40+/-2 mL/min; at 6 months, 36+/-3 mL/min; at 12 months, 39+/-3 mL/min; and at 24 months, 39+/-4 mL/min. When stratified by degree of renal function, values were similarly stable. Patients with a baseline serum creatinine level of 2 mg/dL or less had C-G CrCl values as follows: baseline, 53+/-3 mg/dL; 6 months, 43+/-4 mg/dL; 12 months, 46+/-4 mg/dL; and 24 months, 52+/-5 mg/dL. Those with a baseline serum creatinine level greater than 2 mg/dL had C-G CrCl values as follows: baseline, 26+/-2 mg/dL; 6 months, 31+/-4 mg/dL; 12 months, 32+/-6 mg/dL; and 24 months, 23+/-3 mg/dL. Of eight patients who were dialysis dependent, four (50%) recovered renal function with a mean serum creatinine level of 2.3+/-0.5 mg/dL at 15+/-6 months (range, 9 to 24 months). Stent placement for the treatment of atherosclerotic ostial RAS has a high success rate and a low rate of restenosis. Control of hypertension improves in most patients. Renal function stabilizes or improves in the majority of patients, even those with severe renal failure. These favorable outcomes are maintained long term.

Managing care, managing change, managing information.

Under managed care, information is often required on a longitudinal--not an episodic--basis. As a result, we need to rethink our approach to data storage and use. The author identifies ways to look at the demand for data in a managed care environment and shows how process assessment and benchmarking can help HIM professionals do their jobs more effectively.

Drinking after intragastric NaCl without increase in systemic plasma osmolality in rats.

Drinking after intragastric hypertonic solutions was examined to determine whether increased plasma osmolality always accompanied initiation of drinking. A 2-ml infusion through a gastric catheter was the beginning of tests in Sprague-Dawley male rats. Latency to drink was shorter and 1-h water intake was greater for increasing concentrations of NaCl (600, 1,200, and 1,800 mosmol/kg) compared with baseline (290 mosmol/kg). Although 600, 900, or 1,200 mosmol/kg NaCl elicited drinking, such infusions failed to change systemic plasma osmolality, and 900 mosmol/kg also failed to change plasma sodium, protein, renin activity, or packed cell volume at the initiation of drinking. Intragastric 900 mosmol/kg sodium bicarbonate, sodium isethionate, potassium chloride, lithium chloride, and mannitol differentially increased water intake. Total subdiaphragmatic vagotomy abolished drinking elicited by intragastric NaCl; selective gastric or hepatic vagotomy attenuated intake under some conditions. These results support the hypothesis of a vagally mediated, gastrointestinal and/or hepatic-portal, osmosensitive mechanism for initiation of drinking in advance of postprandial increases in systemic osmolality.

Neonatal caffeine exposure and seizure susceptibility in adult rats.

Early developmental exposure to caffeine in rats results in changes in brain excitability that persist to adulthood. The mechanism of these alterations is unknown. To identify potential neurotransmitter systems involved, we exposed neonatal rats to caffeine and determined seizure thresholds for chemoconvulsants active at different CNS receptors in the adult animal. Rats were unhandled (NH) or received by gavage (0.05 ml/10 g) either vehicle (water) or caffeine (15-20 mg/kg/day) for postnatal days 2-6. At age 70-90 days, each rat was infused intravenously (i.v.) with picrotoxin (PIC), bicuculline (BIC) [convulsants acting at the gamma-aminobutyric acid/benzodiazepine (GABA/BDZ) receptor], pentylenetetrazol [PTZ, possibly acting at both GABA/BDZ and N-methyl-D-aspartate (NMDA) receptors], caffeine (acting at adenosine receptors), strychnine (STR, acting at glycine receptors), or kainic acid (KA, acting at the NMDA receptor). Seizure thresholds were analyzed as a function of neonatal treatment and sex. Thresholds for caffeine, PTZ, PIC, and KA were increased as a function of neonatal caffeine exposure (p = 0.01, 0.02, 0.02, and 0.005, respectively). The thresholds for BIC and STR were not altered. There were also gender differences in seizure susceptibility. Thresholds for seizures produced by BIC, caffeine, PIC, and STR were higher in females (p = 0.005, 0.005, 0.001, and 0.0001, respectively), but were not different for seizures caused by PTZ. These results suggest that early developmental exposure to caffeine affects later seizure susceptibility. Moreover, some of these effects are gender specific.

Cost reduction opportunities in radiology departments.

The recent institution of prospective methods of hospital reimbursement has created a strong incentive to reduce costs. Significant savings were achieved in the cardiovascular-interventional radiology section of our hospital by obtaining competitive bids, purchasing in bulk, purchasing certain comparable but less expensive supplies, reducing film use, and altering patterns of use of some supplies.

Digital subtraction angiography: principles and pitfalls of image improvement techniques.

The technology of imaging methods in digital subtraction angiography (DSA) is discussed in detail. Areas covered include function of the video camera in both interlaced and sequential scan modes, digitization by the analog-to-digital converter, logarithmic signal processing, dose rates, and acquisition of images using frame integration and pulsed-sequential techniques. Also discussed are various methods of improving image content and quality by both hardware and software modifications. These include the development of larger image intensifiers, larger matrices, video camera improvements, reregistration, hybrid subtraction, matched filtering, recursive filtering, DSA tomography, and edge enhancement.

The desktop personal computer for the radiology manager.

Although the benefits of a central computer in the operation of a successful radiology department have been well documented, there has been no information regarding the use of the personal computer by the radiology manager. The personal computer is specifically designed to be used by one person and does not require the operator to be a computer expert. Many practical daily functions can be performed by using this computer. These uses will be described based upon my own experience over the last eight months.

Causes of cine image quality deterioration in cardiac catheterization laboratories.

Deterioration of cineangiographic image quality can result from malfunctions or technical errors at a number of points along the cine imaging chain: generator and automatic brightness control, x-ray tube, x-ray beam geometry, image intensifier, optics, cine camera, cine film, film processing, and cine projector. Such malfunctions or errors can result in loss of image contrast, loss of spatial resolution, improper control of film optical density (brightness), or some combination thereof. While the electronic and photographic technology involved is complex, physicians who perform cardiac catheterization should be conversant with the problems and what can be done to solve them. Catheterization laboratory personnel have control over a number of factors that directly affect image quality, including radiation dose rate per cine frame, kilovoltage or pulse width (depending on type of automatic brightness control), cine run time, selection of small or large focal spot, proper object-intensifier distance and beam collimation, aperture of the cine camera lens, selection of cine film, processing temperature, processing immersion time, and selection of developer.

New equipment considerations for angiograhic laboratories.

The modern angiographic laboratory should be equipped to perform peripheral, visceral, and interventional procedures. Biplane, magnification, multiangulation, and spot filming capabilities are all desirable. Power requirements have decreased in recent years as a result of the introduction of rare earth screen-film systems and the incorporation of carbon fiber into tabletops and film changer faceplates. As a result, generators with lower power outputs and x-ray tubes with smaller focal spots can be used. Multiangulation rotational mounting units have been developed in recent years by the major equipment manufacturers; these units have major advantages over older ones, but their designs incorporate certain drawbacks with which angiographers should be familiar.

A survey of the chromatographic analysis of natural insect juvenile hormones and the insect growth regulator, altosid.

A brief survey of gas and liquid chromatographic methods for analysis, purification and quantitation of natural insect juvenile hormones and one commercially used analoh, altosid (methoprene) insect growth regulator, includes references to the most recent literature.

Argyrophilic carcinoids in two Syrian hamsters (Mesocricetus auratus).

Argyrophilic carcinoids were found in 2 Syrian hamsters (Mesocricetus auratus). A solitary neoplasm was located in the glandular stomach of a 25.5-month-old animal that had ingested for 12 months laboratory chow to which arecoline and calcium hydroxide [Ca(OH)2] had been added. In the other hamster, a primary carcinoid of the pancreas had metastasized to the mesenteric lymph nodes and liver; this was in a 22-month-old animal that had ingested for 16 months chow containing added snuff and Ca(OH)I. It is not known whether the carcinoids were spontaneous or induced by the treatment. Argyrophilic carcinoids have previously been reported in only one other rodent species.

Determination of altosid insect growth regulator in waters, soils, plants, and animals by gas-liquid chromatography.

Residues of isopropyl (2E,4E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate (Altosid) insect growth regulator are determined in waters, soils, plants, milk, eggs, fish, shellfish, poultry and cattle tissues, blood, urine, and feces. Acetonitrile is the primary extraction solvent for all samples. Residues are extracted by high-speed blending followed by vacuum filtration. Fatty extracts are subjected to cold-temperature precipitation and filtration. Samples are cleaned up by petroleum ether partitioning and Florisil and neutral alumina chromatography. The concentrated eluants are analyzed by gas-liquid chromatography (GLC) on columns of differing polarity, using hydrogen flame ionization detectors. The identity of suspected residues is confirmed by additional GLC and by mass fragmentography. The lower limits of detection were: water samples, 0.0004-0.001 ppm; soils, blood, and urine, 0.001 ppm; forage grasses, forage legumes, and rice foliage, 0.005 ppm; and milk, eggs, fish, shellfish, poultry and cattle tissues, and feces, 0.010 ppm.

Mutants of Bacillus subtilis bacteriophage phi e defective in dTTP-dUTP nucleotidohydrolase.

Mutants of bacteriophage phie inducing only 1 to 5% of wild-type levels of dTTP-dUTP nucleotidohydrolase give normal bursts of viable progeny phage whose DNA contains 5 to 10% thymine (but no uracil) in place of 5-hydroxymethyluracil. The relative heat lability of one phage mutant enzyme solubilized from the membrane fraction of infected cells suggests that a phie gene codes for the induced dTTPase-dUTPase.