Overall adsorption rate of metronidazole, dimetridazole and diatrizoate on activated carbons prepared from coffee residues and almond shells.

This study analyzed the overall adsorption rate of metronidazole, dimetridazole, and diatrizoate on activated carbons prepared from coffee residues and almond shells. It was also elucidated whether the overall adsorption rate was controlled by reaction on the adsorbent surface or by intraparticle diffusion. Experimental data of the pollutant concentration decay curves as a function of contact time were interpreted by kinetics (first- and second-order) and diffusion models, considering external mass transfer, surface and/or pore volume diffusion, and adsorption on an active site. The experimental data were better interpreted by a first-order than second-order kinetic model, and the first-order adsorption rate constant varied linearly with respect to the surface area and total pore volume of the adsorbents. According to the diffusion model, the overall adsorption rate is governed by intraparticle diffusion, and surface diffusion is the main mechanism controlling the intraparticle diffusion, representing >90% of total intraparticle diffusion.

Reversal of radiocontrast medium toxicity in human renal proximal tubular cells by white grape juice extract.

Radiocontrast media (RCM)-induced nephrotoxicity (CIN) is a major clinical problem accounting for 12% of all hospital-acquired cases of acute kidney injury. The pathophysiology of CIN is not well understood, but direct toxic effects on renal cells have been postulated as contributing to CIN. We have investigated the effect of a white grape (Vitis vinifera) juice extract (WGJe) on human renal proximal tubular (HK-2) cells treated with the radiocontrast medium (RCM) sodium diatrizoate. WGJe caused an increase in phosphorylation of the prosurvival kinases Akt and ERK1/2 in HK-2 cells. Treatment of HK-2 cells with 75 mgI/ml sodium diatrizoate for 2.5h and then further incubation (for 27.5h) after removal of the RCM caused a drastic decrease in cell viability. However, pre-treatment with WGJe, prior to incubation with diatrizoate, dramatically improved cell viability. Analysis of key signaling molecules by Western blotting showed that diatrizoate caused a drastic decrease in phosphorylation of Akt (Ser473), FOXO1 (Thr24) and FOXO3a (Thr32) during the initial 2.5h incubation period, and WGJe pre-treatment caused a reversal of these effects. Further analysis by Western blotting of samples from HK-2 cells cultured for longer periods of time (for up to 27.5h after an initial 2.5h exposure to diatrizoate with or without WGJe pre-treatment) showed that WGJe pre-treatment caused a negative effect on phosphorylation of p38, NF-κB (Ser276) and pERK1/2 whilst having a positive effect on the phosphorylation of Akt, FOXO1/FOXO3a and maintained levels of Pim-1 kinase. WGJe may alleviate RCM toxicity through modulation of signaling molecules that are known to be involved in cell death and cell survival and its possible beneficial effects should be further investigated.

Protective effect of adrenomedullin on contrast induced nephropathy in rats.

BACKGROUND AND AIMS: Contrast-induced nephropathy (CIN) has a growing incidence in which renal vasoconstriction and medullary hypoxia are important mechanisms. Therapeutic approaches are very restricted and there is a considerable interest in advancing preventive strategies. Adrenomedullin is a relatively novel peptide having antioxidant, vasoactive and vasodilatory properties. We aimed to investigate whether adrenomedullin might have a preventive role against the development of experimental CIN. METHODS: Wistar albino rats (n=24) were allocated randomly into four equal groups of 6 each; Control (C), Adrenomedullin (A), Contrast Media (CM) and Adrenomedullin plus Contrast Media (ACM). All rats were deprived of water from day 1 to day 4 during 72 hours. Then, intravenous administrations of chemicals were performed. Adrenomedullin was given at dose of 12µg/kg to groups A and ACM. A single dose of high-osmolar contrast media; diatrizoate (Urografin 76%, Schering AG, Germany) was injected to groups CM and ACM at dose of 10mL/kg. On day 1 and 6 blood samples were drawn for renal function tests and inflammatory markers including TNF-α IL-1β, IL-6 and IL-18. After sacrification, kidney histologies were examined with hematoxylin-eosin staining. RESULTS: Compared to CM group, serum cystatin-C levels on 6th day were found significantly lower in ACM group (p<0.05). Additionally, daily protein excretion rates, absolute changes in daily urine output and creatinine clearance values were significantly lower in ACM group than those in CM group (p<0.05). In histopathological evaluation, regarding the degree of tubular damage and medullary congestion scores, ACM group had slightly better scores compared to CM group; however the differences did not reach significance as shown in inflammatory markers. CONCLUSION: This study demonstrated a beneficial impact of adrenomedullin on deteriorated renal function tests in an experimental CIN model. Adrenomedullin might be a candidate agent for prophylaxis of CIN. However, further studies are needed to shed more light on this issue.

Removal of the iodinated X-ray contrast medium diatrizoate by anaerobic transformation.

The iodinated X-ray contrast medium diatrizoate is known to be very persistent in current wastewater treatment as well as in environmental compartments. In this study, the potential of anaerobic processes in soils, sediments, and during wastewater treatment to remove and transform diatrizoate was investigated. In anaerobic batch experiments with soil and sediment seven biologically formed transformation products (TPs) as well as the corresponding transformation pathway were identified. The TPs resulted from successive deiodinations and deacetylations. The final TP 3,5-diaminobenzoic acid (DABA) was stable under anaerobic conditions. However, DABA was further transformed under air atmosphere, indicating the potential for the mineralization of diatrizoate by combining anaerobic and aerobic conditions. With the development of a methodology using complementary liquid chromatography-electrospray ionization-tandem mass spectrometry and liquid chromatography-inductively coupled plasma-mass spectrometry techniques, all identified TPs were quantified and the mass balance could be closed without having authentic standards for four of the TPs available. The detection and quantification of diatrizoate TPs in groundwater, in technical wetlands with anaerobic zones, and in a pilot wastewater treatment plant established for anaerobic treatment highlights the transferability and up-scaling of the results attained by laboratory experiments to environmental conditions.

Mitochondria-targeted peptides prevent on contrast-induced acute kidney injury in the rats with hypercholesterolemia.

OBJECTIVE: The objective of this study is to evaluate the effect and mechanism of mitochondria-targeted peptides (MTP131 and SPI20) on contrast-induced acute kidney injury (CI-AKI) in rats with hypercholesterolemia. METHOD: Forty SD rats were randomly divided into normal diet group (NN, n = 8) and high cholesterol supplemented dietary group (HN, n = 32). At the end of 8 weeks, the group HN was divided into four subgroups. All Rats were given injection of either diatrizoate (10 mL/kg) or equal volume of normal saline, the rats pretreated with MTP131 or SPI20 were given injection with MTP131 or SPI 20 (3 mg/kg) by peritoneal cavity for 3 times. Blood, urine and renal tissue samples were prepared to determine biochemical parameters. The renal pathological changes were evaluated by hematoxylin and eosin staining and scored semiquantitatively, The protein expression of renal NOX4 was also measured by Western blotting. RESULTS: In diatrizoate-injected rats, Serum creatinine (Scr), fractional excretion of sodium (FeNa%), fractional excretion of potassium (FeK%), pathological scores, renal malondialdehyde (MDA) content, the NADPH oxidase activity and the expression of NOX4 in kidney tissue were significantly increased (p < 0.01). In the groups pretreated with MTP131 or SPI20, the levels of Scr, FeNa%, FeK%, MDA content and NADPH oxidase activity in renal tissue decreased (p < 0.01), the levels of renal super oxygen dehydrogenises and ATPase activity increased (p < 0.01). The renal injuries induced by contrast media (CM) were alleviated. CONCLUSION: MTP131 and SPI20 might protect acute kidney injury induced by CM in rats with hypercholesterolemia.

Na+/Ca2+ exchange inhibitor, KB-R7943, attenuates contrast-induced acute kidney injury.

BACKGROUND: Intracellular Ca2+ overload is considered to be a key factor in contrast-induced acute kidney injury (CI-AKI). The Na+/Ca2+ exchanger (NCX) system is one of the main pathways of intracellular Ca2+ overload. We investigated the effects of KB-R7943, an inhibitor of the reverse mode of NCX, on CI-AKI in a rat model. METHOD: Rats were divided into control group, CI-AKI group and pretreatment groups (with KB-R7943 dose of 5 or 10 mg/kg). CI-AKI was induced by diatrizoate administration in rats with cholesterol-supplemented diet for 8 weeks. Renal function and renal hemodynamics were determined 1 day following contrast medium administration. Renal histopathology was observed by light microscope. Renal tubular apoptosis was examined by TUNEL. Renal endothelin-1 (ET-1) was measured by radioimmunoassay. Renal malondialdehyde (MDA) and catalase (CAT) were measured as oxidative markers. RESULTS: Levels of serum creatinine (Scr), renal ET-1, MDA and CAT, and resistance index (RI) of renal blood vessels increased significantly in CI-AKI rats. The increases in Scr and RI of renal blood vessels induced by diatrizoate were suppressed significantly and dose-dependently by pretreatment with KB-R7943. Histopathological and TUNEL results showed that the contrast medium-induced severe renal tubular necrosis and apoptosis were significantly and dose-dependently attenuated by KB-R7943. KB-R7943 significantly suppressed the increment of renal ET-1 content and MDA and CAT level induced by contrast medium administration. CONCLUSION: Activation of the reverse mode of NCX, followed by ET-1 overproduction and increased oxidative stress, seems to play an important role in the pathogenesis of CI-AKI. The inhibitor of the reverse mode of NCX, KB-R7943, has renoprotective effects on CI-AKI.

Ascending tonic-clonic seizure syndrome in a dog following inadvertent intrathecal use of ionic contrast agent.

OBJECTIVE: To describe the successful management of ascending tonic-clonic seizure syndrome in a dog after inadvertent intrathecal administration of ionic contrast material. CASE SUMMARY: A 7-year-old, 5.9 kg, male castrated Miniature Pinscher inadvertently received intrathecal ionic contrast material during a myelogram to investigate cervical pain. Ascending tonic-clonic muscle spasms quickly progressed to generalized seizure activity that was resistant to anticonvulsant medications. The dog developed complete respiratory arrest, which necessitated mechanical ventilatory support for 26 hours. Pneumonia developed and was treated successfully. After resolution of seizure activity and resumption of voluntary respiration, the dog remained tetraparetic for 16 days and was not able to walk on his own for 20 days post contrast injection. Despite a prolonged recovery, the patient survived and recovered normal neurologic function. NEW OR UNIQUE INFORMATION PROVIDED: Intrathecal administration of ionic contrast material resulting in ascending tonic-clonic seizure syndrome is rarely reported in the human and veterinary literature. No previous veterinary report has described successful treatment after prolonged respiratory arrest. In previous veterinary reports, patients recovered complete neurologic function within hours to days in contrast to this report in which the patient was tetraparetic for 16 days. This report demonstrates complete recovery from intrathecal ionic contrast administration is possible despite a high dose of contrast and a prolonged recovery.

Low-volume hybrid bowel preparation combining saline laxatives with oral contrast agents versus standard polyethylene glycol lavage for colonoscopy.

PURPOSE: The aim of this study was to compare the quality of low-volume hybrid computed tomography colonography bowel preparation, using both laxatives and oral contrast, with standard polyethylene glycol lavage. METHODS: The study group consisted of 300 consecutive adults (mean age, 58.3 years) who underwent colonoscopy immediately after positive computed tomography colonography. Hybrid bowel preparation for study group was <1 L in total volume, consisting of osmotic cathartic (sodium phosphate or magnesium citrate) in conjunction with oral contrast (2% barium and diatrizoate). A control group of 300 adults (mean age, 58.3 years) underwent primary colonoscopy after standard 4-liter polyethylene glycol lavage without oral contrast. The prospective preparation quality rating by the endoscopist served as the reference standard. A rating of poor/marginal was considered inadequate and adequate/good/excellent was considered diagnostic. RESULTS: The frequency of inadequate bowel preparation was 4.3% (13/300) in the study group vs 12.3% (37/300) for the control group (P < .001). Specifically, preparation was poor or marginal in 10 and 3 cases in the hybrid cohort, respectively, and in 29 and 8 cases in the polyethylene glycol cohort, respectively. Preparation quality was scored as excellent in 32% (96/300) in the hybrid cohort and 23.3% (70/300) in the polyethylene glycol cohort (P < .05). CONCLUSIONS: At colonoscopy, low-volume laxative-oral contrast hybrid preparations are effective for bowel cleansing, perhaps even more so than polyethylene glycol lavage. Beyond improvements in quality, the low-volume preparation may improve patient compliance and would allow for immediate computed tomography colonography if colonoscopy is incomplete, without the need for additional oral contrast tagging.

Identification of particulates in vaccine formulations containing aluminum phosphate.

Density gradient centrifugation was used for identification of particulates in vaccines formulated with aluminum phosphate (AlPO(4)) adjuvant. Protein-derived particulates are sporadically seen in protein pre-filled formulations where siliconized syringes are employed. These particulates are difficult to distinguish from the AlPO(4) suspension. Prior to centrifugation, Histopaque solution is placed at the bottom of the test tube (or the original syringe), resulting in a layer beneath the suspension. After brief centrifugation, AlPO(4) settles to the bottom of the test tube, while the light-weighted particulates in the sample become visible, floating in the inter-phase between the two layers.

Chronic diverticulitis: clinical, radiographic, and pathologic findings.

OBJECTIVE: The purpose of our study is to present a series of 14 patients with chronic diverticulitis on barium enema examinations and to correlate the radiographic findings with the clinical and pathologic findings in these patients. CONCLUSION: Chronic diverticulitis is a distinct pathologic entity characterized by the frequent development of chronic obstructive symptoms and abdominal pain rather than the classic clinical findings of acute sigmoid diverticulitis. Barium enema examinations usually reveal a relatively long segment of circumferential narrowing in the sigmoid colon with a spiculated contour and tapered margins, sometimes associated with retrograde obstruction. Our experience suggests that chronic diverticulitis can often be diagnosed on the basis of the characteristic clinical and radiographic findings in these patients.

Rapid metal-catalyzed hydrodehalogenation of Iodinated x-ray contrast media.

Iodinated X-ray contrast media (ICM) are detected in natural waters at high concentrations relative to other pharmaceuticals due to extensive use in medical diagnostics and high recalcitrance during conventional wastewater treatment. This study examines, for the first time, reductive treatment of ICM in water with hydrogen gas in combination with supported palladium and porous nickel catalysts. Kinetic experiments demonstrate rapid and complete hydrodehalogenation of both ionic (diatrizoate) and neutral (iopromide) ICM. Reaction rates in batch systems (continuous mixing, P(H2) = 0.1 MPa, 25 degrees C) appear to be surface-reaction controlled and are dependent upon catalyst identity (e.g., 5 wt % versus 1 wt % Pd/ Al2O3) as well as the concentration of ICM and catalyst. Reaction rates are not markedly affected by ICM structure, pH, or by the presence of many common ions (Na+, Ca2+, Mg2+, F-, Cl-, Br-, ClO4-, SO4(2-), HCO3-, and NO3-). In contrast, elevated concentrations of iodide, (bi)sulfide, and dissolved organic matter inhibit hydrodehalogenation of ICM. However, catalyst activity can be regained by washing the catalyst (e.g., with water, NaOCl, or alkaline solution). Catalytic reduction of ICM present in treated wastewater effluent is slower than in deionized water, but similar reaction rates are observed when the effluent is pretreated to reduce the level of dissolved organic matter. The high selectivity of reductive catalytic treatment processes suggest that this is a promising strategy for targeted treatment of ICM present in mixed waste streams and natural water matrices containing much higher concentrations of nontarget constituents.

Efficacy and safety of percutaneous transhepatic portal embolization before right liver resection using an ethibloc/lipiodol mixture: a single-center experience.

AIM: The purpose of this study was to evaluate the safety and efficacy of percutaneous transhepatic portal vein embolization of the right portal vein with an Ethibloc/Lipiodol mixture to induce hypertrophy of the left liver lobe in patients with primarily unresectable liver tumor. METHODS: 15 patients (8 primary liver tumors, 7 liver metastases) underwent portal vein embolization. Liver volumetry, duration of hospitalization, complication rates, relevant laboratory values were documented. RESULTS: In 13/15 patients (84.6%) embolization could be performed with a median of 8.8 ml (range 1.5-28 ml) Ethibloc/Lipiodol. One minor procedure-related complication (subcapsular hematoma) occurred, which did not affect the two-step liver resection. No patient developed acute liver failure after embolization or liver resection. The volume of the left liver lobe increased significantly (p = 0.0015) by 25% from a median of 750 ml (587-1,114 ml) to 967 ml (597-1,249 ml). 11/13 (81.8%) of the embolized patients underwent liver resection at a median of 49 days after embolization. Median hospitalization time was 4 days after embolization and 7 days after liver resection. Median overall survival of the 11 operated patients was 376 days. CONCLUSION: Percutaneous transhepatic portal vein embolization using an Ethibloc/Lipiodol mixture is a safe, feasible, and efficient interventional procedure.

Percutaneous portal vein embolisation in preparation for extended hepatic resection of primary nonresectable liver tumours.

BACKGROUND: In patients with malignant primary and secondary liver tumours or proximal bile duct carcinoma radical surgery is superior to all other therapeutic modalities in terms of survival and quality of life. Radical resection, however, often requires the removal of a large amount of liver parenchyma, resulting in a marked reduction of functional liver tissue with the risk of liver failure. AIM: Preoperative partial portal vein embolisation induces hypertrophy of the controlateral liver and thereby increases the safety of extended liver resections. PATIENTS AND METHODS: Between January 1997 and February 2001 we applied this strategy in 19 patients with primary and secondary nonresectable hepatobiliary malignancies, in whom the estimated amount of the remnant liver was < or =25% of the liver volume. RESULTS: The increase in volume ranged between 7 and 245%. Radical extended liver resection was performed in 13 patients (68%) without mortality. After a mean observation time of 22 months patient survival was 19 months with six tumour-related deaths during the second year after surgery. The remaining seven patients are alive and well with tumour recurrence in one. CONCLUSION: Preoperative partial portal vein embolisation allows more patients with previously unresectable liver tumours to benefit from a potentially curative resection.

Intralesional Ethibloc injections in primary aneurysmal bone cysts: an efficient and safe treatment.

OBJECTIVE: Ethibloc is a fibrogenic and thrombogenic agent recently proposed for the treatment of bone cysts. The purpose of this study is to report the results of direct Ethibloc injection in primary aneurysmal bone cyst (ABC) in children. DESIGN AND PATIENTS: Seventeen patients, aged from 2 to 18 years (mean 8 years), were treated with either a single injection (14 patients) or supplementary injections (3 patients) of Ethibloc. The histological diagnosis was assessed following surgical biopsy and was retrospectively reviewed. The mean follow-up was 5 years (range 18 months to 11 years). RESULTS: At 5 year follow-up, 14 of 17 patients demonstrated complete healing manifest by increased cortical and septal thickening. Surgical excision was required in three patients, in two of whom the ABC increased rapidly in size despite the injection, and in one of whom the healing was incomplete. We observed inflammatory reactions in 16 of 17 patients with local pain and fever. Three patients developed a small cutaneous fistula which resolved spontaneously in a few weeks. No major complications such as deep infection, pulmonary embolism, epiphyseal necrosis or malignant degeneration were observed. CONCLUSION: Percutaneous direct Ethibloc injection is a safe, efficient and noninvasive treatment for ABC. The authors highlight the frequent local reactions.

Peripheral blood eosinophilia associated with gastrointestinal administration of iodinated contrast media.

OBJECTIVE: This study was designed to assess whether gastrointestinal administration of iodinated contrast media results in peripheral blood eosinophilia. MATERIALS AND METHODS: We studied 110 patients in a retrospective review. Diatrizoate meglumine and diatrizoate sodium for abdominal CT were administered to 98 of these patients; 22 of the 98 had also been given the same contrast medium administered by enema. The remaining 12 patients were given diatrizoate sodium for gastrointestinal fluoroscopy. A control group of 65 patients underwent single-contrast barium upper gastrointestinal or enema examinations. WBC and eosinophil counts were determined approximately 24 hr before the examination and every 24 hr thereafter, through the ninth day. RESULTS: Eosinophilia was detected in 17 (15.5%) of 110 patients after gastrointestinal administration of iodinated contrast media. The prevalence of eosinophilia after administration of iodinated contrast media was statistically significantly different compared with that in the control group, in which none of the 65 patients had eosinophilia (p < 0.001). Eosinophilia was detected 48 hr after application of iodinated contrast agents and lasted through the sixth day, with a peak on the fifth day. The prevalence of eosinophilia was independent of route of application, dose, or type of iodinated contrast medium. Eosinophilia in all cases was clinically asymptomatic. CONCLUSION: Eosinophilia that is caused by gastrointestinal administration of iodinated contrast media is a transient, clinically silent phenomenon. It may lead to unnecessary workup for known conditions associated with eosinophilia.

[Which imaging in case of sigmoid diverticulitis? The value of ultrasound (Conventional B-mode in combination with hydrocolonsonography and colour flow Doppler) in comparison to the well-established modalities like contrast enema and helical computertomography]. / Welche bildgebende Diagnostik bei Verdacht auf eine Sigmadivertikulitis? - Wertigkeit der sonographischen Untersuchungsverfahren (konventionelle B-Bild-Diagnostik in Kombination mit der Hydrokolonsonographie und der farbkodierten Duplexsonographie) im Vergleich mit den etablierten Verfahren wie dem Kolon-Kontrasteinlauf und der Spiral-Computertomographie -

Sigmoid diverticulitis is in case of complications like perforation, abscess and peritonitis a life-threatening disease. A diagnostic work up with high sensitivity is mandatory. In a prospective study upon 247 patients with the possible diagnosis of acute diverticulitis ultrasound is a screening method with a high specificity (97 %) and leads in combination with the hydrocolonsonography and the colour flow doppler to a high sensitivity (76 %). Without any typical findings in ultrasound, helical CT scan is the best method in the evaluation of the acute diverticulitis (sensitivity and specificity 100 %), because contrast enema is inferior to CT in the evaluation of abscesses (6 %) and perforation (53 %). CT has in case of perforation and of abscesses a sensitivity of 90 % and 100 %, while ultrasound has a sensitivity of 12 % to perforation and of 39 % to abscesses.

The use of dilute Calogen as a fat density oral contrast medium in upper abdominal computed tomography, compared with the use of water and positive oral contrast media.

AIM: Oral contrast media are commonly given prior to computed tomography (CT) examination of the upper abdomen. Although positive oral contrast media are normally used, there is increasing interest in using negative agents such as water and less commonly fat density products. The aim of this study was to compare a positive oral contrast medium, water, and a diluted emulsion of arachis oil Calogen, a fat density food supplement) for assessment of the upper abdomen. MATERIALS AND METHODS: Seventy-one patients referred for upper abdominal CT were randomized to receive either 500 ml water, 2% sodium diatrizoate or a dilute suspension of Calogen. The CT images were scored independently by three radiologists. Distension and anatomical identification was assessed for the stomach, duodenum and jejunum; with anatomical identification recorded for the pancreas, retroperitoneum, liver, gallbladder and spleen. RESULTS: Dilute Calogen produced a significant improvement (P < 0.01) in distension and anatomical visualization of the stomach and proximal duodenum. Only minimal differences were demonstrated between the three contrast media for visualization of more distal small bowel or identification of the other upper abdominal viscera. Significantly more artifacts were caused by positive contrast media than with the Calogen mixture. CONCLUSION: A dilute suspension of Calogen as an oral contrast medium is recommended when disease is suspected within the stomach or proximal duodenum.

Effects of adenosine receptor antagonists on the responses to contrast media in the isolated rat kidney.

Contrast media can induce both a decrease in renal blood flow and a reduction in glomerular filtration rate (GFR) when administered to both experimental animals and humans. In the present study we have examined the role of adenosine in mediating these effects using the isolated perfused rat kidney. Kidneys were perfused with a 6. 7%-(w/v)-albumin-based perfusate supplemented with glucose and amino acids (n=6 per group). They were exposed to diatrizoate [20 mg of iodine (mgI)/ml; osmolality 1650 mOsm/kg of water] or iotrolan (20 mgI/ml; osmolality 320 mOsm/kg of water) in the presence or absence of theophylline (10.8 microg/ml), or to diatrizoate in the presence or absence of a specific adenosine A(1) receptor antagonist (KW-3902; 2 microg/ml) or a specific A(2) receptor antagonist (KF17837; 6 microg/ml). Diatrizoate (n=6) produced a fall in GFR from 0.65+/-0.04 to 0.42+/-0.03 ml.min(-1).g(-1) (P<0.05); renal perfusate flow (RPF) also declined, from 36.5+/-3.8 to 22.0+/-3.2 ml. min(-1).g(-1) (P<0.05). Iotrolan (n=6) produced a fall in GFR from 0. 64+/-0.02 to 0.48+/-0.04 ml.min(-1).g(-1) (P<0.05) and in RPF from 33.3+/-3.8 to 24.0+/-3.0 ml.min(-1).g(-1) (P<0.05). Theophylline (10.8 microg/ml) prevented the fall in GFR caused by either diatrizoate (baseline, 0.63+/-0.05 ml.min(-1).g(-1); diatrizoate+theophylline, 0. 60+/-0.04 ml.min(-1).g(-1)) or iotrolan (baseline, 0.64+/-0.04 ml. min(-1).g(-1); iotrolan+theophylline, 0.67+/-0.05 ml.min(-1).g(-1)), but did not affect the decreases in RPF caused by either agent. KW-3902 (2 microg/ml) also prevented the fall in GFR produced by diatrizoate (baseline, 0.66+/-0.05 ml.min(-1).g(-1); diatrizoate+KW-3902, 0.61+/-0.05 ml.min(-1).g(-1)), while the fall in RPF remained unaffected. KF17837 (6 microg/ml) had no effect on the decreases in either GFR or RPF induced by diatrizoate (n=6 per group). The results suggest a role for adenosine acting at the A(1) receptor in mediating the decrease in GFR induced by contrast media. This effect is independent of a change in renal vascular resistance, and possibly secondary to mesangial cell contraction causing a decrease in the ultrafiltration coefficient.

Percutaneous fluoroscopic gastrostomy tube placement in patients with head and neck cancer.

OBJECTIVE: To study the safety and efficacy of percutaneous fluoroscopic gastrostomy tube placement in patients with head and neck cancer. DESIGN: We conducted a retrospective case review of 92 consecutive cases. Comparable access procedures and relevant literature were reviewed. SETTING: Academic tertiary care center. PATIENTS: Patients with head and neck cancer who underwent percutaneous fluoroscopic gastrostomy tube placement between January 1996 and July 1996. MAIN OUTCOME MEASURES: Immediate, delayed, and long-term complications; tube malfunction; and tube placement failure. RESULTS: The major complication rate was 1%; the minor complication rate was 8%; and the tube malfunction rate was 13%. The rate of successful tube placement was 98%. None of the patients required hospitalization as a result of the procedure. CONCLUSIONS: Percutaneous fluoroscopic gastrostomy tube placement is a safe, economical, and comfortable method that has distinct advantages over other gastrostomy tube placement methods. It is recommended for enteral feeding and nutritional supplementation in patients with head and neck cancer.