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R Bartkowski

Publications and source records attributed to R Bartkowski.

44 records · Page 3Linked to original sources
PubMed1988

Hepatic arterial infusion (HAI) chemotherapy proves to be advantageous in the treatment of experimental liver tumors.

To evaluate the best locoregional approach in the treatment of hepatic tumors we investigated four different treatment modalities. Sixty female Sprague-Dawley rats were randomized to the following treatment groups: (1) untreated control; (2) hepatic artery ligation; (3) hepatic artery ligation plus portal 5-FU chemotherapy; (4) arterial 5-FU chemotherapy; (5) portal 5-FU chemotherapy. All animals received Novikoff hepatoma cells inoculated in the median liver lobe. After tumor inoculation animals were treated according to their randomization and surgery was performed for repeated tumor size measurements. Through hepatic artery ligation, hepatic artery ligation plus portal 5-FU infusion as well as through arterial 5-FU infusion a significant tumor growth inhibition compared to the untreated control could be achieved. The portal infusion group even showed an accelerated tumor growth; however, this effect was not significant. We conclude that the intraarterial application in terms of clinical feasibility and duration of response should be the preferred approach in locoregional therapy of liver malignancies.

Animals↗
PubMed1988

Numerical and experimental study of steady-state CO2 and inert gas washout.

The predictions of a single-path trumpet-bell numerical model of steady-state CO2 and infused He and sulfur hexafluoride (SF6) washout were compared with experimental measurements on healthy human volunteers. The mathematical model used was a numerical solution of the classic airway convention-diffusion equation with the addition of a distributed source term at the alveolar end. In the human studies, a static sampling technique was used to measure the exhaled concentrations and phase III slopes of CO2, He, and SF6 during the intravenous infusion of saline saturated with a mixture of the two inert gases. We found good agreement between the experimentally determined normalized slopes (phase III slope divided by mixed expired concentration) and the numerically determined normalized slopes in the model with no free parameters other than the physiological ones of upper airway dead space, tidal volume, breathing frequency, and breathing pattern (sinusoidal). We conclude 1) that the single-path (Weibel) trumpet-bell anatomic model used in conjunction with the airway convection-diffusion equation with a distributed source term is adequate to describe the steady-state lung washout of CO2 and infused He and SF6 in normal lungs and 2) that the interfacial area separating the tidal volume fron from the functional residual capacity gas, through which gas diffusion into the moving tidal volume occurs, exerts a major effect on the normalized slopes of phase III.

Carbon Dioxide↗
PubMed1987

Feasible model for locoregional and systemic longterm administration of drugs and concomitant blood sampling in Sprague-Dawley rats.

This methodological study describes three surgical procedures for locoregional and systemic drug administration, which are based on a similar experimental design. Cannulation of the arterial and portal access to the liver in comparison to the general venous system, and arterial access to the large intestine through a permanently implantable system, suitable for serial bolus injections and infusions in unrestrained rats, is presented (experiment I). Furthermore, an infusion system for longterm administration (experiment II) and a method for blood sampling during locoregional or systemic infusion procedures (experiment III) have been developed. The positioning and free flow of the catheters were checked by means of scintigraphy, administration of fluorescein under UV light and angiography in animals of experimental series I. After 7 days, no obstruction was detected. On day 15 and 30 following implantation 73.3% and 58.3% of the animals, respectively, showed unimpeded flow through the catheter system. The methods described here were well tolerated by the animals without alteration of their general condition and are currently in use in a series of chemotherapeutic and pharmacokinetic investigations.

Animals↗
PubMed1986

Experiments on the efficacy and toxicity of locoregional chemotherapy of liver tumors with 5-fluoro-2'-deoxyuridine (FUDR) and 5-fluorouracil (5-FU) in an animal model.

For the investigation of locoregional chemotherapy of liver neoplasms we developed a standardized animal model in the rat. Continuous infusion therapy or repeated bolus injections of FUDR or 5-FU were given via the hepatic artery, the portal vein or the vena cava in tumor-bearing animals. The efficacy of the treatment was determined by measuring the tumor volume 3 weeks after tumor cell implantation. For the evaluation of the local and systemic toxicity serum GOT, GPT, and total bilirubin were determined. DNA single strand breaks were assessed in isolated liver and bone marrow cells. Inhibition of colony formation of bone marrow stem cells was determined by CFU-C and CFU-S bioassay. A significant reduction of tumor growth was observed only after continuous infusion of FUDR via the hepatic artery. Systemic toxicity was lowest in this group for both compounds while the local liver toxicity was only slightly elevated.

Animals↗
PubMedDate not supplied

Intubating conditions after pipecuronium bromide: the influence of dose and time.

STUDY OBJECTIVE: To determine the intubating conditions following the administration of pipecuronium bromide in doses of two (0.07 mg/kg) or three (0.1 mg/kg) times ED95 (average dose that gives 95% block of the first twitch). DESIGN: To compare intubating conditions at 11/2 and 21/2 minutes in 41 patients receiving balanced anesthesia. SETTING: Surgical patients at Thomas Jefferson University Hospital. PATIENTS: Forty-one patients undergoing surgical procedure who received general anesthesia. INTERVENTIONS: After obtaining a stable baseline of train-of-four (TOF), 41 patients randomly received either 0.07 mg/kg or 0.1 mg/kg of pipecuronium as a single intravenous (IV) bolus dose, and the trachea was intubated either at 11/2 or 21/2 minutes. MEASUREMENTS AND MAIN RESULTS: Intubating conditions at 21/2 minutes appeared significantly better than those at 11/2 minutes, regardless of the pipecuronium dose. The mean time for T1 (first twitch of TOF) to reach 50% and 90% suppression was 1.36 +/- 0.51 minutes and 2.29 +/- 0.8 minutes, respectively, for the 0.07 mg/kg dose and 1.07 +/- 0.27 minutes and 1.72 +/- 0.45 minutes, respectively, for the 0.1 mg/kg dose. This did not make a significant difference in intubating conditions at either time. The time to 25% recovery of T1 was 68.2 +/- 22 minutes for the 0.07 mg/kg dose and 121.5 +/- 49 minutes for the 0.1 mg/kg dose. In patients who had spontaneous recovery of T1 to between 10% and 25% of control, administration of neostigmine or edrophonium resulted in identical recovery in 10 minutes. However, in patients with less than 10% spontaneous recovery of T1, neostigmine appeared to be superior to edrophonium. CONCLUSION: Pipecuronium has a relatively rapid onset. The trachea could be intubated successfully in 11/2 minutes with a dose of either 0.07 mg/kg or 0.1 mg/kg. If the clinical situation requires perfect relaxation with no movement or bucking, we recommend waiting at least 21/2 minutes.

Adult↗
PubMedDate not supplied

Inversion recovery snapshot FLASH MR imaging.

Snapshot fast low angle shot (FLASH) magnetic resonance (MR) imaging techniques have been developed to enable real time imaging of MR parameters. The method is based on a 64 x 128 FLASH tomogram acquired within less than 200 ms. This work describes snapshot FLASH MR using a single 180 degrees pulse prior to the acquisition of a series of FLASH images. The experiment creates continuous dynamic inversion recovery (IR) T1 contrast in successive images. The total acquisition time of 16 images displaying the IR behavior is less than 4 s. Representative snapshot FLASH IR MR images of the abdomen of healthy rats and of an implanted hepatic tumor are illustrated.

Animals↗
PubMedDate not supplied

Sufentanil stellate ganglion injection in the treatment of refractory reflex sympathetic dystrophy.

Reflex sympathetic dystrophy is a neurologic disorder with characteristic symptomatology including burning dysesthesia, swelling, and vasomotor alteration. Two patients with refractory reflex sympathetic dystrophy underwent stellate ganglion injection with 10 mcg of sufentanil in 10 ml preservative-free saline. Both reported decrease in pain and improved mobility, which was long lasting.

Adult↗