What is the best contemporary treatment for in-stent restenosis?

In-stent restenosis (ISR) remains a challenging problem in percutaneous coronary intervention and the optimal treatment strategy remains unclear. The aim of this study was to compare the 18 month clinical outcomes in patients receiving sirolimus-eluting stents (SES) with vascular brachytherapy (VBT) for the treatment of ISR. Twenty-five consecutive patients treated with VBT were compared with 29 patients who had SES deployment for ISR.

Use of water-equivalent plastic scintillator for intravascular brachytherapy dosimetry.

Beta irradiation has recently been investigated as a possible technique for the prevention of restenosis in intravascular brachytherapy after balloon dilatation or stent implantation. Present methods of beta radiation dosimetry are primarily conducted using radiochromic film. These film dosimeters exhibit limited sensitivity and their characteristics differ from those of tissue, therefore the dose measurement readings require correction factors to be applied.

Impact of oedema on implant geometry and dosimetry for temporary high dose rate brachytherapy of the prostate.

The optimal timing of dosimetry for permanent seed prostatic implants remains contentious given the half life of post-implant oedema resolution. The aim of this study was to establish whether prostatic oedematous change over the duration of a temporary high dose rate (HDR) interstitial brachytherapy (BR) boost would result in significant needle displacement, and whether this change in geometry would influence dosimetry. Two CT scans, one for dosimetric purposes on the day of the implant and the second just prior to implant removal, were obtained for four patients receiving transperineal interstitial prostate brachytherapy.

Monte Carlo dosimetry of a tandem positioned beta-emitting intravascular brachytherapy source train.

Prevention of restenosis following interventional coronary procedures with catheter based beta-emitting sources is currently under clinical trial investigations. Systems utilizing fixed length source trains limit the clinician's ability to increase the radiation source length as required. A technique known as "pull back" is used when the segment of artery requiring radiation is longer than the available fixed length source train.

Therapeutic effect of dimethyl sulfoxide on ICAM-1 gene expression and activation of NF-kappaB and AP-1 in septic rats.

Background: Dimethyl sulfoxide (DMSO) is a potent antioxidant which protects against endotoxemia and septic shock in animal models. We investigated the therapeutic effect of DMSO on intercellular adhesion molecule 1 (ICAM-1) gene expression and activation of nuclear factor-kappaB (NF-kappaB) and activating protein-1 (AP-1) in a rat model of peritonitis sepsis. This postchallenge model simulates the clinical treatment of ruptured viscus peritonitis.

Dosimetry errors in endovascular high-dose-rate brachytherapy.

Monte Carlo data were used to demonstrate the dosimetry of the microSelectron high-dose-rate (HDR) iridium 192 (192Ir) stepping source. These data were used to assess the accuracy of the Nucletron brachytherapy planning system (BPS version 13) for peripheral vessel endovascular brachytherapy. Dose rates from the high-dose-rate (HDR) source are calculated using the Monte Carlo code MCNP4A.

Verification of brachytherapy dosimetry with radiochromic film.

The aim of this work is to empirically validate the optimized dose distribution calculated by the Nucletron Brachytherapy Planning System (v. 13.3) at a distance of 1.

Inhibitory effect of dimethyl sulfoxide on nuclear factor-kappa B activation and intercellular adhesion molecule 1 gene expression in septic rats.

Antioxidants are potent radical scavengers that protect against endotoxemia and septic shock in animal models. Using a rat model of peritonitis sepsis induced by cecal incision we studied the effect of the free radical scavenger dimethyl sulfoxide (DMSO) on hepatic nuclear factor kappa B (NF-kappa B) activation, hepatic intercellular adhesion molecule 1 (ICAM-1) gene expression, serum tumor necrosis factor alpha (TNF) formation, and serum glucose concentration. Five groups of rats (N = 5) were treated as follows: (1) untreated control (Untreated), (2) sham operated with laparotomies (Sham), (3) pretreated with 6 ml/kg DMSO followed by sham operation (DMSO/Sham), (4) cecal incision (Sepsis), and (5) pretreated with DMSO followed by cecal incision (DMSO/Sepsis).

Dose errors in the near field of an HDR brachytherapy stepping source.

The dose rate at point P at 0.25 cm in water from the transverse bisector of a straight catheter with an active stepping source (Nucletron microSelectron HDR source) with a dwell length of 2 cm was calculated using Monte Carlo code MCNP 4.A.

Standard linear plans in single channel high dose rate brachytherapy: a dosimetric analysis.

The use of standard linear plans is proposed for single channel intraluminal High Dose Rate brachytherapy. This technique employs the optimized dwell times derived from a straight line within a curved geometry. Such standardization of the planning procedure ensures expedient delivery of treatment.

The contribution of 18F-fluoro-2-deoxy-glucose positron emission tomographic imaging to radiotherapy planning in lung cancer.

A retrospective analysis was performed to determine whether coronal thoracic [18F]fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) scans, if viewed at the time of radiotherapy (RT) planning, would have influenced the anterior-posterior (AP) RT volumes that were administered to a group of unoperated lung cancer patients. Viewing of PET and diagnostic images enabled a qualitative assessment of whether abnormal thoracic PET activity was present in areas regarded as normal by diagnostic imaging; this would, therefore, have influenced the RT volume if done prospectively. Additionally a method of graphical co-registration was devised to quantitate the adequacy of coverage of each patient's abnormal PET activity by his/her actual RT field.

Effect of dexamethasone on NF-kB activation, tumor necrosis factor formation, and glucose dyshomeostasis in septic rats.

Glucocorticoids are potent anti-inflammatory and immunosuppressive therapeutic agents. The protective effect of dexamethasone (DEX) on hepatic phosphoenolpyruvate carboxykinase (PEPCK) transcript level, hepatic NF-kB (nuclear factor-kB) activation, and serum tumor necrosis factor alpha (TNF) formation was investigated in peritoneal sepsis induced by cecal incision in rats. For the control the rats were sham-operated with laparotomies only.

Efficacy of anti-tumor necrosis factor polyclonal antibody on phosphoenolpyruvate carboxykinase expression in septic and endotoxemic rats.

We studied the protective effect of anti-tumor necrosis factor-alpha (anti-TNF) polyclonal antibody on phosphoenolpyruvate carboxykinase (PEPCK) expression in lipopolysaccharide-induced endotoxemia and peritonitis sepsis induced by cecal incision. At 3 h after intraperitoneal lipopolysaccharide injection, levels of serum glucose, liver glycogen, and PEPCK expression were decreased and serum TNF was elevated. In contrast, 3 h after cecal incision, levels of serum glucose, serum TNF, and PEPCK expression were elevated.

The utility of the Philips SRI-100 Real Time Portal Imaging Device in a case of postoperative irradiation for prevention of heterotopic bone formation following total hip replacement.

The new Radiation Oncology Department at the Heidelberg Repatriation Hospital in Melbourne, Australia commenced operation in June 1992. As part of quality control the Philips SL-15 linear accelerator was fitted with the Philips SRI-100 Real Time Portal Imaging Device (RTPID), the first such apparatus in Australia. One of its major advantages over older systems is its ability to provide a permanent hard copy of the image of the field treated.

Altered levels of mRNA encoding enzymes of hepatic glucose metabolism in septic rats.

We investigated whether the multiple pathophysiological signals generated in a peritonitis septic model alter the mRNA levels of glycolytic and gluconeogenic enzymes, and whether these alterations are associated with glucose dyshomeostasis. Rats were sham-operated in the control group, and peritonitis sepsis was produced by a 1 cm cecal incision in the septic group. At 2, 4, and 6 hr post-surgery, total cellular RNAs were isolated from livers, and Northern blots performed to measure mRNA levels of aldolase B (ADL), lactate dehydrogenase (LDH), pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and glucokinase (GK).

Alterations in the activities of DNA topoisomerase enzymes and O6-methylguanine-DNA-methyltransferase in septic rat liver.

To understand the genomic changes contributing to the various metabolic derangements in sepsis and septic shock, we measured the activities of the following liver enzymes intimately associated with DNA function: (1) DNA topoisomerases I and II (topo I and topo II) controlling DNA conformation in mammalian nuclei, and (2) O6-methylguanine-DNA-methyltransferase (MT) capable of removing the methyl groups from the O6-position of guanine in DNA. We found that in septic rat livers the specific activities (units/mg protein) of topo II and MT were elevated by 1.4- and 1.

Lung and muscle water after crystalloid and colloid infusion in septic rats: effect on oxygen delivery and metabolism.

We compared the effect of crystalloid infusion with that of colloid infusion on extravascular lung water and muscle water in septic rats. We also examined the relationship of lung and muscle edema to arterial oxygenation and muscle energy metabolism during sepsis. Cecal ligation and perforation were used to induce sepsis.

Early impairment of oxidative metabolism and energy production in severe sepsis.

We investigated the relationship of systemic blood flow to skeletal muscle tissue oxygenation, lactate production, and energy production during rat peritonitis established by cecal ligation and perforation. The study included five sham rats, five septic rats, and five septic rats infused with 5% albumin. Thermodilution cardiac output and skeletal muscle tissue oxygen tension were sequentially measured over a 6 hr interval.

Liver gluconeogenic metabolites in young and old rats during septic shock.

Aged individuals have diminished resistance to severe sepsis and septic shock. Previous studies in young animals showed that the liver's gluconeogenic capacity was an important determinant of survival in shock states. This study compared hepatic carbohydrate intermediates from young rats and old rats to correlate changes during peritonitis septic shock with known differences in survival times.

Effect of aging on hepatic carbohydrate metabolism in septic rats.

Aged individuals have diminished resistance to severe sepsis and septic shock. Past work with animals suggested that an important determinant of survival was the ability of the liver to supply glucose. In this study, young adult (3 to 4 months) and old (24 months) Fischer 344 rats were fasted and subjected to cecal incisions producing a rapidly lethal peritonitis.

Hepatic glycolytic intermediates in fed and fasted rats after severe hemorrhage.

The responses of key liver carbohydrate intermediates to severe hemorrhage were investigated in fed and fasted young adult male rats. Forty per cent of intravascular blood was withdrawn and liver was sampled by freeze-clamp at 0, 0.25, 1.

Endotoxin lethality is intensified by inhibited gluconeogenesis.

There are two major etiologies regarding the lethal element in the pathophysiology of endotoxemia and severe gram-negative sepsis: 1) metabolic lesions culminating in terminal hypoglycemia and 2) circulatory deficits resulting in early peripheral and late vital organ perfusion failure. Although not mutually exclusive, a direct test of the relative importance of either hypothesis is needed. The impact of inhibited gluconeogenesis on endotoxin lethality in young adult male rats (180-220 g) was investigated.