Anti-inflammatory pre-treatment and the resultant effects of interleukin-10: adjuncts to multi-therapeutical strategies

With the advent of off-pump coronary bypass surgery, there is increasing demand for research in attenuating the deleterious effects of cardiopulmonary bypass (CPB). An improved understanding of the systemic inflammatory response syndrome (SIRS) has distinguished which areas of components have the most adverse effects and which are, in fact, anti-inflammatory. This classification of inflammatory components allows strategic treatment for those likely to cause the most clinically significant 'effect', suitably termed 'effectors'. This article will identify current methods in treating 'effectors', as well as those components having anti-inflammatory effects. This article selectively features certain inflammatory components by: (1) grouping them as being 'mediators' or 'effectors'; (2) relating them to interleukin-10 (IL-10) and treatments potentiating anti-inflammatory effects; (3) summarizing their mechanisms of action; (4) recognizing the time periods during bypass exhibiting peak levels; and (5) investigating current treatment. methods and identifying their significance to 'effectors'. A literature search in MEDLINE was performed, featuring articles of the English-language within the past 5 years. Because of the characteristic of having interlinked multi-component cascades, it is evident that treating SIRS with a one-dimensional method would be inadequate. This article not only confirms the importance of a multi-factorial therapeutic approach, but also targets the inflammatory components having the highest potential for causing direct tissue damage, known as 'effectors'. In addition, previous studies have found IL-10 to have 'regulatory effects' during periods of excessive pro-inflammatory stimuli. These findings may arouse new ideas in exploring the area of anti-inflammatory cytokines. In fact, future treatments may suggest a new classification featuring 'mediators', 'effectors', and 'regulators'.

A novel platinum-iridium, potentially gamma radioactive stent: evaluation in a porcine model

In-stent restenosis (ISR) is a major problem within stented arteries. Surface treatment of stents with platinum and gold were found to have the maximum charge with least neointima formation (NF). This study was designed to evaluate platinum (maximum electrical charge) as a material to make stents to reduce NF. Iridium was added to make an alloy suitable for stent manufacture, with the potential to make the stent radioactive. We implanted the novel platinum-iridium (PI) stent in 10 porcine coronaries and compared to the Palmaz-Schatz (PS) stent implanted in 8 coronary arteries. Six weeks after implantation, angiography of the stented vessel was performed before sacrifice. The coronaries were perfusion-fixed and stained, and vessel parameters were analyzed by computer-aided histomorphometry. The thrombus formation and the inflammatory response was less in the PI stent (0.04 +/- 0.1 vs. 0.24 +/- 0.2, P = 0.005; and 1.1 +/- 0.5 vs. 2.4 +/- 0.3, P < 0.001). The NF from PI-stented arteries was smaller in size than the PS controls (1.9 +/- 0.6 mm(2) vs. 2.4 +/- 0.4 mm(2), P = 0.06). However, PI stents presented with higher recoil than the PS stent (16% vs. 5%, P < 0.001). Platinum-iridium is a highly biocompatible material with high performance, low inflammatory response with small NF. This stent does not lead to thrombus formation and has the potential (due to the presence of iridium) to be irradiated to form a gamma radioactive stent. Cathet. Cardiovasc. Intervent. 51:364-368, 2000.

S-nitrosoglutathione reduces nonocclusive thrombosis rate following balloon overstretch injury and intracoronary irradiation of porcine coronary arteries

PURPOSE

Intracoronary radiation (IR) suppresses neointima formation following balloon injury in animal models. High doses of radiation exacerbate thrombosis and delay re-endothelialization. The free radical nitric oxide (NO) has been reported to inhibit platelet aggregation, reduce neointimal hyperplasia, and stimulate re-endothelialization. This study examined the effects of a chemical NO donor on neointima formation, thrombosis, and healing of irradiated porcine coronary arteries.

METHODS AND MATERIALS

Vascular lesions were created in the coronary arteries of 59 domestic swine by overstretch balloon injury. Arteries were then left untreated or were treated with intracoronary gamma-radiation using Iridium-192 in each artery to deliver 5 or 15 Gy at 2 mm from the center of the source. The chemical NO donor S-nitrosoglutathione (GSNO) was infused i.v. at a rate of 250 microg/min for 10 min before injury, followed by a continuous infusion for 60 min. Animals were euthanized at 14 days and their arteries were analyzed for histomorphometric indices of proliferation and thrombosis.

RESULTS

A dose of 15 Gy reduced the ratio of intimal area to medial fracture length (IA/FL) versus control (0.06 +/- 0.05 0.54 +/- 0.10 [p < 0. 001]) but increased the nonocclusive thrombosis rate compared to controls (85% vs. 30%; p < 0.05). A low dose of 5 Gy did not affect neointima formation. Treatment with GSNO reduced thrombosis in all treated groups: control, 15%; 5 Gy, 18%; and 15 Gy, 35% (p < 0.05) without affecting neointima formation.

CONCLUSION

Systemic administration of GSNO during balloon injury and IR was tolerated well by the swine and resulted in reduction of the thrombosis rate, especially at high doses, without apparent effect on neointima formation.

Vascular repair after balloon overstretch injury in porcine model effects of intracoronary radiation

OBJECTIVES

The purpose of this study was to evaluate the effect of IR on thrombus formation and dissection repair following overstretch balloon injury in porcine coronary arteries.

BACKGROUND

Exposure of blood to the injured arterial wall after percutaneous transluminal coronary angioplasty (PTCA) induces thrombus formation and inflammation in the dissection plane. Neointima formation is related to smooth muscle cell (SMC) proliferation and migration into the preformed thrombus. Intracoronary radiation (IR) with doses of 10 to 25 Gy using either beta or gamma emitters can prevent neointima accumulation by reducing SMC proliferation. However, there are some indications that IR may delay the process of dissection repair after PTCA. The purpose of this study was to evaluate the effect of IR on thrombus formation and dissection repair after overstretch balloon injury in porcine coronary arteries.

METHODS

Forty porcine coronaries were injured by balloon overstretch followed by either 0 or 18 Gy of 90Y prescribed to 1.2 mm from the balloon center. The animals were euthanized 14 days after treatment, and intimal area (IA) and IA corrected for medial fracture length (IA/FL) were quantified by digital image analysis. Dissections were quantified by tracing the length, thickness and area behind the dissection flap. The rate of dissections was calculated for each group. Thrombi were identified and designated as intraluminal thrombus or thrombus within dissection planes (mural thrombus), and area measurements were obtained.

RESULTS

The irradiated group showed a significant reduction of IA/FL (0.55 +/- 0.29 vs. 0.05 +/- 0.09; p < 0.001). No difference was observed in the rate of dissection between control and irradiated arteries (77% vs. 88%, respectively). The control group showed a smaller dissection area (0.19 +/- 0.28 mm2 vs. 0.32 +/- 0.29 mm2; p < 0.05) with smaller mural thrombi (0.03 +/-0.01 mm2 vs. 0.29 +/- 0.30 mm2; p < 0.001). A strong correlation between dissection area and neointima area was observed only in the control group (R2 = 0.474; p < 0.003; alpha0.05 = 0.862). A positive correlation between mural thrombus and dissection area was observed only in the irradiated group (R2 = 0.889; p < 0.001; alpha0.05 = 1.00).

CONCLUSIONS

These results suggest that the dissection area may be a useful parameter by which to quantify the extent of injury and repair after IR and may indicate an incomplete healing process after IR at this time point.

Dose-finding, safety, and tolerability study of an oral platelet glycoprotein IIb/IIIa inhibitor, lotrafiban, in patients with coronary or cerebral atherosclerotic disease

BACKGROUND

Antiplatelet therapy is the mainstay of the treatment and secondary prevention of cardiovascular and cerebrovascular ischemic events. We assessed the safety, tolerability, and pharmacodynamics of lotrafiban, an oral platelet glycoprotein IIb/IIIa inhibitor, as a secondary prevention strategy in patients with cerebrovascular or cardiovascular disease.

METHODS AND RESULTS

Overall, 451 patients with a recent cardiovascular or cerebrovascular acute ischemic event were randomized in a double-blind fashion to 1 of 5 dosing regimens for 12 weeks: placebo or 5, 20, 50, or 100 mg lotrafiban, both twice daily with 300 to 325 mg/d aspirin. The primary end point was the incidence and tolerability of major and minor bleeding during treatment. Secondary end points included inhibition of platelet aggregation and clinical events. The placebo and lotrafiban 5-mg groups had similarly low rates of minor and major bleeding, but the 100-mg arm was terminated early because of excess major bleeding. Protocol-defined thrombocytopenia (<100 000 platelets/microL) occurred in 5 lotrafiban-treated patients (1.4%, 95% CI 0.2% to 2.7%) and 1 placebo patient (1.1%, 95% CI 0% to 3.1%). Three lotrafiban-treated patients had a nadir platelet count <20 000/microL (0.9%, 95% CI 0% to 1.8%). Lotrafiban produced dose-dependent inhibition of platelet aggregation; 5 mg lotrafiban did not differ significantly from placebo, whereas 100 mg inhibited aggregation by nearly 100%.

CONCLUSIONS

-Lotrafiban provides dose-dependent platelet inhibition when administered to a range of patients with atherosclerosis. The level of platelet inhibition appears to correlate with bleeding risk and drug tolerability.

Sex workers' perspectives on condom use for oral sex with clients: a qualitative study

The authors conducted in-depth interviews with 46 female brothel-based sex workers to explore their perceived barriers and approaches in getting clients to use condoms for oral sex. Reasons given by sex workers for not using condoms for oral sex as compared to vaginal sex included self-perception of low vulnerability to AIDS and sexually transmitted infections, misconceptions on transmission of the HIV virus, lack of negotiation skills, lack of support from brothel keepers and peers, and unpleasant taste and smell of condoms. Some sex workers could get all their clients to use condoms for oral sex by using negotiation skills, including the positive approach, the fear approach, the emotional appeal approach, and the assertive approach. Findings from this study would help design more appropriate messages and improve negotiation skills of sex workers to increase consistent condom use for oral sex.

Identification of multiple genital HPV types and sequence variants by consensus and nested type-specific PCR coupled with cycle sequencing

Consensus and type-specific HPV primers were employed for PCR and cycle sequencing of genital HPVs in scrapings and colposcopically directed biopsies of the cervix from a cohort of 188 female sex workers. A total of 27 individuals tested positive for a broad spectrum of HPV types, including HPVs 6b, 16, 18, 31, 33, 34, 35, 45, 56 and 58, as well as a new HPV type, with seven individuals displaying dual infections. Good correlation between the results of individually paired samples was observed. A HPV 16 primer biotinylated at the 5' end was also used as a probe, which could successfully detect amplified products of HPV 16 but not other HPV types tested by an automated ELISA detection system. DNA sequence analysis revealed several HPV sequence variants that harbored mutations, especially in the E6 gene, many of which culminated in non-conservative amino acid substitutions in the transforming E6 oncoprotein. Such an approach of coupling PCR with cycle sequencing permits the determination of many known and even novel HPV types associated with varying degrees of risk to cervical carcinogenesis, and enables the identification of HPV sequence variants of putative biological and clinical significance, thus justifying its utility as an adjunct tool to complement cervical cytology and colposcopy. This study also emphasises the need for educational, interventional and behavioral modification to minimise HPV transmission, such as through consistent condom usage among sex workers.

Design of the blockade of the glycoprotein IIb/IIIa receptor to avoid vascular occlusion (BRAVO) trial

BACKGROUND

Platelets play a key role in the pathogenesis of atherosclerosis, thrombosis, and acute coronary and cerebrovascular syndromes. Inhibition of platelet function by acetylsalicylic acid (aspirin) has been shown to reduce the incidence atherothrombotic events in patients with coronary, cerebrovascular, or peripheral vascular disease. Thienopyridine agents, however, including ticlopidine and clopidogrel, inhibit the adenosine diphosphate receptor and have modestly superior effects compared with aspirin on reduction of death, myocardial infarction, and stroke among a broad group of patients with vascular disease. More effective antithrombotic agents are still required to treat patients at high risk for recurrent vascular events.

METHODS

Lotrafiban, a selective, nonpeptide antagonist of the human platelet fibrinogen receptor (glycoprotein [GP] IIb/IIIa [alphaIIb/beta3 integrin]), blocks the binding of fibrinogen to the GP IIb/IIIa receptor, which is the final common pathway of platelet aggregation. Lotrafiban at doses of up to 50 mg twice daily was well-tolerated in a 12-week, double-blind, placebo-controlled, dose-ranging study in patients with recent myocardial infarction, unstable angina, transient ischemic attack, or stroke when added to aspirin therapy. On the basis of these results, a dosing regimen was selected for the phase III Blockage of the Glycoprotein IIb/IIIa Receptor to Avoid Vascular Occlusion (BRAVO) trial based on pharmacodynamics and drug tolerability. In the pivotal BRAVO study, lotrafiban therapy is being evaluated in patients who have had a recent myocardial infarction, unstable angina, transient ischemic attack, or ischemic stroke, or who present at any time after a diagnosis of peripheral vascular disease combined with either cardiovascular or cerebrovascular disease.

RESULTS

The efficacy evaluation will be based on a composite end point of clinical events (death by any cause, myocardial infarction, stroke, recurrent ischemia requiring hospitalization, or urgent ischemia-driven revascularization). The target enrollment is 9200 patients worldwide. Approximately 700 centers will participate and will be distributed within 30 countries across North America, Europe, Australia, and Asia.

Three-dimensional anatomic characterization of the canine laryngeal abductor and adductor musculature

The biomechanics of vocal fold abduction and adduction during phonation, respiration, and airway protection are not completely understood. Specifically, the rotational and translational forces on the arytenoid cartilages that result from intrinsic laryngeal muscle contraction have not been fully described. Anatomic data on the lines of action and moment arms for the intrinsic laryngeal muscles are also lacking. This study was conducted to quantify the 3-dimensional orientations and the relative cross-sectional areas of the intrinsic abductor and adductor musculature of the canine larynx. Eight canine larynges were used to evaluate the 3 muscles primarily responsible for vocal fold abduction and adduction: the posterior cricoarytenoid, the lateral cricoarytenoid, and the interarytenoid muscles. Each muscle was exposed and divided into discrete fiber bundles whose coordinate positions were digitized in 3-dimensional space. The mass, length, relative cross-sectional area, and angle of orientation for each muscle bundle were obtained to allow for the calculations of average lines of action and moment arms for each muscle. This mapping of the canine laryngeal abductor and adductor musculature provides important anatomic data for use in laryngeal biomechanical modeling. These data may also be useful in surgical procedures such as arytenoid adduction.

Aneurysm of a jejunal branch of the superior mesenteric artery in a patient with Marfan's syndrome

A case of post-traumatic aneurysm of a jejunal branch of the superior mesenteric artery in a patient with Marfan's syndrome is reported. Ascending aortic involvement is well known in Marfan's syndrome but no association with visceral artery aneurysms has been previously described. The blunt abdominal trauma preceding the detection of the aneurysm may have been the precipitating cause in a predisposed patient. Because of the high risk of rupture, aneurysms of the superior mesenteric artery branches should be treated. Excision or ligation without restoring continuity are the most common surgical procedures; endovascular embolization is an alternative option especially in high risk patients.

Mice deficient for corticotropin-releasing hormone receptor-2 display anxiety-like behaviour and are hypersensitive to stress

Corticotropin-releasing hormone (Crh) is a critical coordinator of the hypothalamic-pituitary-adrenal (HPA) axis. In response to stress, Crh released from the paraventricular nucleus (PVN) of the hypothalamus activates Crh receptors on anterior pituitary corticotropes, resulting in release of adrenocorticotropic hormone (Acth) into the bloodstream. Acth in turn activates Acth receptors in the adrenal cortex to increase synthesis and release of glucocorticoids. The receptors for Crh, Crhr1 and Crhr2, are found throughout the central nervous system and periphery. Crh has a higher affinity for Crhr1 than for Crhr2, and urocortin (Ucn), a Crh-related peptide, is thought to be the endogenous ligand for Crhr2 because it binds with almost 40-fold higher affinity than does Crh. Crhr1 and Crhr2 share approximately 71% amino acid sequence similarity and are distinct in their localization within the brain and peripheral tissues. We generated mice deficient for Crhr2 to determine the physiological role of this receptor. Crhr2-mutant mice are hypersensitive to stress and display increased anxiety-like behaviour. Mutant mice have normal basal feeding and weight gain, but decreased food intake following food deprivation. Intravenous Ucn produces no effect on mean arterial pressure in the mutant mice.

Ultrasound-guided renal biopsy: experience using an automated core biopsy system

OBJECTIVE

To assess the safety and efficacy of ultrasound-guided percutaneous renal biopsy using an automated core biopsy system, and to determine radiologists' accuracy in predicting sample adequacy.

METHODS

Ninety-five biopsies were performed on 25 native kidneys and 70 renal allografts using a 16-gauge automated, spring-loaded core biopsy device under real-time sonographic guidance. Radiologists performing the biopsy estimated the number of core samples needed to obtain an adequate specimen, based on visual inspection of each core. The final determination of the number of samples was made by a pathology technologist who attended each biopsy, based on preliminary microscopic examination of tissue cores. After each biopsy, an ultrasonographic examination was performed to search for biopsy-related hemorrhage, and a questionnaire was given to the patient to determine biopsy-related complications, which were categorized as either minor or major.

RESULTS

The main indication for biopsy was acute renal failure (in 43.2% of biopsies). An average of 3 tissue cores per biopsy were obtained. Of the 94 patients in whom a biopsy was conducted to exclude diffuse renal disease, a mean of 12.5 glomeruli were present in each specimen. Overall, adequate tissue for diagnosis was obtained in 98.9% of cases. The radiologists' estimate of the number of core samples needed concurred with the pathology technologists' determination of sample adequacy in 88.4% of cases. A total of 26 complications occurred (in 27.4% of biopsies), consisting of 23 minor (24.2%) and 3 major (3.2%) complications.

CONCLUSIONS

Real-time sonographic guidance in conjunction with an automated core biopsy system is a safe and accurate method of performing percutaneous renal biopsy. Routine use of sonographic examinations to search for biopsy-related complications is not indicated. Radiologists are accurate in estimating sample adequacy in most cases; however, the presence of a pathology technologist at the biopsy procedure virtually eliminates the possibility of obtaining insufficient tissue for histologic diagnosis.

Comparative efficacy of three 5-HT3 antagonists (granisetron, ondansetron, and tropisetron) plus dexamethasone for the prevention of cisplatin-induced acute emesis: a randomized crossover study

The purpose of this study was to compare the antiemetic efficacy of three 5-HT3 antagonists (granisetron, ondansetron, tropisetron) plus dexamethasone for the prevention of acute emesis induced by high-dose cisplatin chemotherapy. This was a randomized, open label, crossover study. Recruited into the study were 94 chemotherapy-naive patients of whom five were excluded because chemotherapy was not given, noncisplatin regimen was used instead, or presence of anticipatory vomiting. The remaining 89 evaluable patients were mostly (86.5%) male, and were all treated for head and neck cancers. The antiemetic regimens consisted of 1) granisetron 3 mg i.v. and dexamethasone 20 mg i.v. on day 1 (GRADEX); 2) tropisetron 5 mg i.v. and dexamethasone 20 mg i.v. on day 1 (TRODEX); and 3) ondansetron 8 mg i.v. and dexamethasone 20 mg i.v. to be followed by ondansetron 8 mg p.o. x 2 on day 1 (ONDEX). Patients were randomized to receive one of the three regimens in the first cycle, and treatment was crossed over to the other two regimens in subsequent cycles. Antiemetic efficacy was assessed using self-report diaries recording the number of vomiting episodes as well as duration and severity of nausea within the first 24 hours. Complete response was defined as no vomiting with or without mild nausea, and major response was defined as one vomiting episode and/or moderate to severe nausea. Major efficacy refers to either complete or major response. A total of 219 cycles was given to 89 patients: 16 received one cycle only, 16 received two cycles, and 57 received three cycles. No carryover effects were observed between cycles. Using pooled data from all cycles, the complete response rates to GRADEX, TRODEX, and ONDEX were 81%, 68%, and 71%, respectively (p = 0.11); the corresponding major efficacy rates were 91%, 93%, and 86%, respectively (p = 0.36). When only the first cycle was considered, the complete response rates to GRADEX, TRODEX, and ONDEX were 81%, 75%, and 74%, respectively (p = 0.58); the corresponding major efficacy rates were 92%, 94%, and 84%, respectively (p = 0.38). Analysis of the crossover data showed that the majority of patients achieved complete response or major efficacy with the different pairs of regimens, and there were no significant differences between different regimens in terms of complete response or major efficacy. The only exception was GRADEX versus TRODEX, in which 15.5% of patient achieved complete response with GRADEX as compared with 1.7% with TRODEX (p = 0.025). The majority of patients (53%) did not report any preference, whereas 14% preferred GRADEX, 15% preferred TRODEX, and 18% preferred ONDEX. The three 5-HT3 antagonists, when used in combination with steroids, had similar major efficacy for prophylaxis against cisplatin-induced acute emesis. Although GRADEX was superior to TRODEX in terms of complete response, this may not be of clinical significance. The choice of antiemetic regimens should therefore depend on patient preference and drug cost.

Oncogenic activating mutations in the neu/erbB-2 oncogene are involved in the induction of mammary tumors

Amplification and overexpression of erbB-2/neu is an important determinant in the initiation and progression of human breast cancer. Indeed, transgenic mice that over-express the neu proto-oncogene heritably develop mammary adenocarcinomas. Tumorigenesis in these transgenic strains is associated with activation of the intrinsic catalytic activity of Neu. In many of these tumors, activation of Neu occurs as a result of somatic mutations located within the transgene itself. Examination of the altered neu transcripts revealed the presence of in-frame deletions that encode aberrant Neu receptors lacking 5 to 12 amino acids within the extracellular domain proximal to the transmembrane region of Neu. In addition to these deletion mutants we have also detected single point mutations within this juxta-transmembrane region. The majority of the mutations analyzed affect the one of several conserved cysteine residues present within this region. Introduction of these activating mutations into the wild-type neu cDNA results in its oncogenic conversion. Taken together, these observations suggest that this cysteine-rich region plays an important role in regulating the catalytic activity of Neu.

Detection of small, functional islet cell tumors in the pancreas: selection of MR imaging sequences for optimal sensitivity

PURPOSE

To determine the sensitivity and specificity of magnetic resonance (MR) imaging for depicting pancreatic small, functional islet cell tumors and the minimum number of sequences for expedient diagnosis.

MATERIALS AND METHODS

Twenty-eight patients clinically suspected to have functional islet cell tumors underwent T1- and T2-weighted spin-echo (SE) MR imaging with and without fat suppression, T2-weighted fast SE imaging, and spoiled gradient-echo (GRE) imaging before and after injection of gadopentetate dimeglumine. Sensitivity, specificity, and the best and minimum number of sequences for definitive diagnosis were determined.

RESULTS

MR images depicted proved islet cell tumors in 17 of 20 patients (sensitivity, 85%). Images were true-negative in eight patients with negative follow-up examination results for more than 1 year. Specificity was 100%; positive predictive value, 100%; and negative predictive value, 73%. Among 20 patients with tumor, T1-weighted SE images with fat suppression and nonenhanced spoiled GRE images each showed lesions in 15 (75%); T2-weighted conventional SE with fat suppression, in 13 (65%); gadolinium-enhanced spoiled GRE, in 12 (60%); and T2-weighted fast SE, in seven of 10 patients (70%).

CONCLUSION

MR imaging accurately depicts small islet cell tumors. T2-weighted fast SE and spoiled GRE sequences usually suffice. Gadolinium-enhanced sequences are needed only if MR imaging results are equivocal or negative.

A gel technology system to determine postpartum RhIG dosage

Failures of Rh immune globulin (RhIG) prophylaxis occur when the dose is too small. We report a test using a gel technology (GT) method to replace the Kleihauer-Betke (K-B) test to assess fetomaternal hemorrhage (FMH) and assist in determining the minimum necessary dose of RhIG. Cord blood (O, D+) was mixed with adult blood (O D-) to mimic an FMH of 10 mL, 20 mL, 28 mL, and 40 mL. Test samples were incubated with anti-D at known concentrations and centrifuged. The supernatant was titrated against D+ and D- red cells using GT and an interpretation of the required RhIG dose was made. Results were compared with the K-B test. Results were easily discernible and interpretations leading to determination of recommended RhIG dosage were reproducible. Correlation to standard K-B testing was confirmed. Elapsed time for result availability by GT testing was 60 minutes, with a direct technical time requirement of 30 minutes. The GT system is easier, objective, and quantitative, and compares well to the standard K-B test. A single procedure will allow assessment of the extent of FMH in the great majority of cases. This technique works well in determining the appropriate dose of anti-D required to treat D- patients with D+ newborns. There are potential cost savings in decreased use of RhIG, less direct technical time required, and more rapid availability of results.

The PRESTO (Prevention of restenosis with tranilast and its outcomes) protocol: a double-blind, placebo-controlled trial

BACKGROUND

Tranilast is a unique drug in clinical development for the prevention of restenosis after percutaneous transluminal coronary revascularization (PTCR). Tranilast interferes with proliferation and migration of vascular medial smooth muscle cells induced by platelet-derived growth factor and transforming growth factor beta1. Collagen synthesis in vascular medial smooth muscle cells is inhibited by tranilast, which also inhibits the release or production of cyclooxygenase-2 and restores cytokine-induced nitric oxide production. These mechanisms may contribute to the reduction of angiographic restenosis after coronary intervention previously reported in clinical studies.

METHODS

The primary objective of this multicenter study of 11,500 patients is to compare the composite clinical event rate of death, myocardial infarction, or the need for ischemia-driven target vessel revascularization of tranilast (300 and 450 mg twice daily) for 1 or 3 months with that of placebo in patients undergoing PTCR with or without stenting for single or multiple vessels over a 9-month period. The lesions can be de novo or restenotic. All revascularization procedures and the use of glycoprotein IIb/IIIa agents are permitted. The inclusion criteria are meant to allow an "all comer" approach for generalization of results to the broadest possible PTCR population. A subset population (n = 2000) will undergo 9-month follow-up angiography, 1000 of which will also undergo intravascular ultrasound (n = 1000). This study is the first tranilast trial to be conducted in a Western population to confirm the improved angiographic findings reported in Japanese patients and to determine if the clinical sequelae of restenosis are also reduced.

CONCLUSION

This multicenter study is the largest restenosis trial planned to date. It will test whether tranilast, a drug with multiple actions aimed at affecting proliferation and migration of vascular smooth muscle cells, can reduce clinical, angiographic, and intravascular ultrasound assessments of restenosis.

Evaluation of a combination rapid immunoassay for detection of Giardia and Cryptosporidium antigens

A combination cassette format nonenzymatic rapid immunoassay for detection of Giardia and Cryptosporidium antigens was evaluated by using 556 patient stool specimens from three clinical laboratories. This assay (Genzyme Diagnostics Contrast Giardia/Cryptosporidium), which can be used with fresh or formalin-fixed specimens, had unadjusted sensitivities and specificities of 96.1 and 98.5% for Giardia and 100 and 98.7% for Cryptosporidium, respectively, in this study.

A new bladder allows kinetic venous augmentation with a roller pump

Augmented venous drainage improves venous return during minimally invasive cardiac surgery. Two systems to augment drainage are common: in one, a centrifugal pump draws blood from the venous site and pumps it into a venous reservoir. In the other, suction is applied directly to a hard-shell venous reservoir. Both systems overcome the high resistance of the venous cannula when gravity alone is insufficient to provide adequate drainage. Both systems also have shortcomings: in the first approach, the centrifugal pump head can entrap large bubbles, reducing flow and requiring pump stoppage to remove them. Air from the venous line also can be broken up by the centrifugal pump into small bubbles that can pass through the pump head. The direct suction system in the second approach cannot use a closed-bag reservoir, and has the potential to introduce air into the arterial line. We have developed a new venous augmentation system for a closed venous reservoir that provides excellent suction control without the potential to introduce air into the arterial line. Our system replaces the centrifugal pump of the first approach with a roller pump controlled by the Better-Bladder, a new device with FDA 510(k) clearance for long-term pumping. The Better-Bladder is a length of medical tubing, processed to form a thin-walled, enlarged bladder that is sealed within a clear rigid housing. It acts as an in-line reservoir that provides compliance in the venous line and a noninvasive means to measure blood pressure at the pump inlet. The bladder housing can maintain a negative pressure set by the user that controls the degree of gravity drainage. Tests have shown that the Better-Bladder allows for safe, smooth pump control using a roller pump in the venous line.

An HPLC method for the determination of diastereomeric prodrug RS-79070-004 in human plasma

Ganciclovir is an antiviral nucleoside analogue approved for treatment and prevention of cytomegalovirus infections in immunocompromised subjects. RS-79070-194, a diastereomeric monovalyl ester of ganciclovir (hydrochloride salt), is under evaluation as a prodrug to increase the bioavailability of ganciclovir. An HPLC method with column switching has been developed and validated for quantification of the corresponding free base RS-79070-004 in human plasma. In the method, proteinaceous material in 0.25 ml of plasma is precipitated by trichloroacetic acid. An aliquot of the supernatant is analyzed by HPLC, with automated column switching to remove late-eluting materials that might interfere with the analyte peaks in subsequent runs. Detection of RS-79070-004 is by UV lambda = 254 nm). The peak areas for each isomer are summed to generate a value for total RS-79070-004. The method has a validated range of 0.0400-4.00 microg/ml and a lower limit of quantification of 0.0400 microg/ml. All intra- and inter-assay %CVs were < 7.5%, and all recoveries (accuracy) were within 6% of nominal values. No interference was observed by ganciclovir, caffeine, acetaminophen, or ibuprofen. Analyte stability in plasma and in the sample extracts is adequate for the specified collection, storage, and analysis conditions. The validated method has been successfully used to analyze clinical study samples.

The influence of hospital-based prescribers on prescribing in general practice

OBJECTIVE

To document the influence of hospital prescribers on prescribing in general practice.

DESIGN AND PARTICIPANTS

Five percent of members of the Irish College of General Practitioners (n = 92) prospectively recorded 40 consecutive prescriptions.

INTERVENTIONS

The name, dose and amount of medicine prescribed as well as the indication for therapy, details of their practice, distribution of private/GMS patients, and the number of years since qualification were recorded. The cost of individual prescriptions was calculated based on the ingredient cost and the number of days of treatment. This was subsequently correlated with the origin of the prescription. Each prescription was classified as either new or repeat.

MAIN OUTCOME MEASURES AND RESULTS

Of 3286 prescriptions, 69% were for the state-supported General Medical Services (GMS) patients and 31% for private patients. Repeat prescriptions constituted 51%; 49% were new prescriptions. While hospital doctors initiated only 8% of private prescriptions, they initiated 38% of GMS prescriptions, particularly repeat prescriptions and those for cardiovascular, hormonal and centrally-acting agents. Prescriptions for anti-infectives, oral contraceptives, dermatological preparations and musculoskeletal drugs were mostly initiated in general practice. The median cost for hospital-initiated GMS prescriptions (5.93 Pounds) was greater than the cost of general practitioner (GP)-initiated prescriptions (3.49 Pounds; p < 0.01). Prescriptions from GPs who were qualified for less than 10 years and those with a mixed urban and rural practice were less costly (p < 0.05) than those issued by doctors qualified for over 10 years or working predominantly in an urban or rural area. These findings may also reflect differences in patient population, morbidity and demography.

CONCLUSIONS

Our study indicates that hospital-initiated prescriptions are responsible for a significant proportion, both in volume and cost of GP prescribing.