Accelerating drug discovery for Alzheimer's disease: best practices for preclinical animal studies

Animal models have contributed significantly to our understanding of the underlying biological mechanisms of Alzheimer's disease (AD). As a result, over 300 interventions have been investigated and reported to mitigate pathological phenotypes or improve behavior in AD animal models or both. To date, however, very few of these findings have resulted in target validation in humans or successful translation to disease-modifying therapies. Challenges in translating preclinical studies to clinical trials include the inability of animal models to recapitulate the human disease, variations in breeding and colony maintenance, lack of standards in design, conduct and analysis of animal trials, and publication bias due to under-reporting of negative results in the scientific literature. The quality of animal model research on novel therapeutics can be improved by bringing the rigor of human clinical trials to animal studies. Research communities in several disease areas have developed recommendations for the conduct and reporting of preclinical studies in order to increase their validity, reproducibility, and predictive value. To address these issues in the AD community, the Alzheimer's Drug Discovery Foundation partnered with Charles River Discovery Services (Morrisville, NC, USA) and Cerebricon Ltd. (Kuopio, Finland) to convene an expert advisory panel of academic, industry, and government scientists to make recommendations on best practices for animal studies testing investigational AD therapies. The panel produced recommendations regarding the measurement, analysis, and reporting of relevant AD targets, th choice of animal model, quality control measures for breeding and colony maintenance, and preclinical animal study design. Major considerations to incorporate into preclinical study design include a priori hypotheses, pharmacokinetics-pharmacodynamics studies prior to proof-of-concept testing, biomarker measurements, sample size determination, and power analysis. The panel also recommended distinguishing between pilot 'exploratory' animal studies and more extensive 'therapeutic' studies to guide interpretation. Finally, the panel proposed infrastructure and resource development, such as the establishment of a public data repository in which both positive animal studies and negative ones could be reported. By promoting best practices, these recommendations can improve the methodological quality and predictive value of AD animal studies and make the translation to human clinical trials more efficient and reliable.

Impact of pharmacotherapy on the incidence of transurethral prostatectomy for benign prostatic hyperplasia and the implications for surgical training

Medical therapy has become first line treatment for Benign Prostatic Hypertrophy (BPH) and in many cases TURP may no longer be required. Proof and quantification of this evolution in practice has been somewhat elusive and provided the principle impetus for this study. This is a retrospective study of BPH management in Republic of Ireland from 1995 to 2008. National treatment databases were sourced for numbers undergoing TURP and pharmacotherapy prescribing data was obtained from individual pharmaceutical companies. A total of 28,240 TURP's were performed nationally between 1995 and 2008. TURP's performed annually, decreased by 1,494 (51%), alpha-blocker prescriptions increased from 8,710 to 302,159 units and the number of urology trainees increased by 10 (60%). Clear association between decreases in TURP's and increases in pharmacotherapy for BPH is demonstrated. Implications on training likely exist and will require proper evaluation in order to maintain future standards in this surgical practice.

Renal artery embolisation in the palliative treatment of renal carcinoma

The aim of this study is to review the role and technique of renal artery embolisation (RAE), and assess its effectiveness in the palliative treatment of unresectable or inoperable renal cell carcinoma (RCC) in our institution. The study group consisted of 19 consecutive patients (16 male, 3 female; age range 47-87 years) who underwent palliative RAE for the treatment of renal carcinoma between January 2000 and December 2005. Unresectable disease was present in 11 patients (3 stage IVa, 8 stage IVb). Potentially resectable disease was present in 8 patients (4 stage II, 1 stage IIIa, 1 stage IIIb, 2 stage IIIc); however, these patients were unfit for surgery for other reasons. 13 patients presented with haematuria, which was gross in 7 patients. Nine patients complained of flank pain. RAE was performed using polyvinyl alcohol or embosphere particles, metallic coils and, in some cases, absolute alcohol was necessary. At the time of analysis, 12 patients had died while 7 patients were still alive, with an overall median survival for the study group of 6 months. In the 7 patients with transfusion dependant gross haematuria, there was stabilization of the haemoglobin level post-embolisation. In the 9 patients who presented with flank pain, symptoms improved or resolved in 8 patients. The median length of hospital stay for the 18 patients who were discharged was 5.0 days. RAE is a safe and tolerable management option for patients with inoperable or unresectable renal carcinoma as a means of palliation of local symptoms and improving clinical status, with low morbidity and shorter hospital stay.

[Extensor mechanism allograft reconstruction after total knee replacement]

We present three cases in which we used a complete extensor mechanism allograft for the reconstruction of an insufficient extensor mechanism after total knee arthroplasty (and failed reconstruction with local tissue in two of these cases). Early results are encouraging. Allograft reconstruction can be taken into consideration as an alternative to arthrodesis in those "worst-case scenarios". Late failure may occur in about 20%, probably due to a lack of revitalisation in the centre of the allograft.

A preventive intervention for pregnant women on public assistance at risk for postpartum depression

OBJECTIVE

Promising results were obtained in an earlier pilot study of a preventive intervention based on the principles of interpersonal psychotherapy to reduce the risk of postpartum major depressive disorder. In this study, the authors examined whether the intervention would reduce the risk of postpartum major depressive disorder in a larger sample of pregnant women.

METHOD

Ninety-nine pregnant women on public assistance who were assessed to be at risk for postpartum depression were randomly assigned to receive standard antenatal care plus the intervention or standard antenatal care only. Diagnostic interviews were administered 3 months after delivery to assess for major depressive disorder.

RESULTS

Within 3 months after delivery, eight (20%) of the women in the standard antenatal care condition had developed postpartum major depressive disorder, compared with two (4%) in the intervention condition.

CONCLUSIONS

This study provides further evidence for the efficacy of a brief intervention to reduce the occurrence of major depressive disorder among financially disadvantaged women during a postpartum period of 3 months.

A preventive intervention for pregnant women on public assistance at risk for postpartum depression

OBJECTIVE

Promising results were obtained in an earlier pilot study of a preventive intervention based on the principles of interpersonal psychotherapy to reduce the risk of postpartum major depressive disorder. In this study, the authors examined whether the intervention would reduce the risk of postpartum major depressive disorder in a larger sample of pregnant women.

METHOD

Ninety-nine pregnant women on public assistance who were assessed to be at risk for postpartum depression were randomly assigned to receive standard antenatal care plus the intervention or standard antenatal care only. Diagnostic interviews were administered 3 months after delivery to assess for major depressive disorder.

RESULTS

Within 3 months after delivery, eight (20%) of the women in the standard antenatal care condition had developed postpartum major depressive disorder, compared with two (4%) in the intervention condition.

CONCLUSIONS

This study provides further evidence for the efficacy of a brief intervention to reduce the occurrence of major depressive disorder among financially disadvantaged women during a postpartum period of 3 months.

Integrated therapy for locally advanced bladder cancer: final report of a randomized trial of cystectomy plus adjuvant M-VAC versus cystectomy with both preoperative and postoperative M-VAC

PURPOSE

We conducted a phase III trial to investigate the timing of chemotherapy with respect to surgery for patients with resectable but high-risk urothelial cancer. The trial was also designed to evaluate the accuracy of clinical staging in patients with locally advanced cancer and the prognostic significance of chemotherapy-induced downstaging.

PATIENTS AND METHODS

A total of 140 uniformly evaluated patients with locally advanced urothelial cancer were studied. Planned treatment was five cycles of chemotherapy (M-VAC: methotrexate, vinblastine, doxorubicin, and cisplatin) plus radical cystectomy and pelvic lymph node dissection. Patients were randomly assigned to receive either two courses of neoadjuvant M-VAC followed by surgery plus three additional cycles of chemotherapy, or, alternatively, to have initial cystectomy followed by five cycles of adjuvant chemotherapy.

RESULTS

There were no significant differences in outcome between the two groups. By intent-to-treat, 81 patients (58%) remain disease-free, with median follow-up of 6.8 years. We confirmed a high rate of clinical understaging in this cohort, especially among patients showing lymphovascular invasion on biopsy. Patients with no residual muscle-invasive disease at cystectomy after neoadjuvant chemotherapy were likely to be cured.

CONCLUSION

These results lend further support to the impression from small randomized trials that, in a high-risk cohort, there is an improved cure fraction by the combination of multiagent chemotherapy and surgery, although we found no preferred sequence. Importantly, it is possible to select appropriate patients for such therapy on the basis of clinical staging information. These results establish a benchmark of outcome for this cohort.

Treatment with low-dose interferon-alpha restores the balance between matrix metalloproteinase-9 and E-cadherin expression in human transitional cell carcinoma of the bladder

Tumor invasion and metastasis are regulated by the expression of genes such as E-cadherin, which regulates cell adhesion, and matrix metalloproteinase-9 (MMP-9), which alters the integrity of the extracellular matrix. Both up-regulation of MMP-9 and down-regulation of E-cadherin correlate with bladder cancer metastasis. The purpose of this study was first to determine whether an imbalance between MMP-9 and E-cadherin expression correlates with metastasis from human transitional cell carcinoma (TCC) of the bladder after therapy with neoadjuvant chemotherapy and radical cystectomy and then to determine whether treatment of human TCC xenografts growing in nude mice with interferon (IFN)-alpha would restore this balance, thereby limiting tumor invasion and metastasis. We used in situ hybridization to evaluate the expression of several metastasis-related genes, including MMP-9 and E-cadherin, in paraffin-embedded biopsy specimens from 55 patients with muscle-invasive TCC treated with neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin chemotherapy and radical cystectomy. By multivariate analysis, an MMP-9:E-cadherin ratio of >1.8 was an independent prognostic factor for disease progression. In vitro incubation of an IFN-resistant, highly metastatic human TCC cell line, 253J B-V(R) with noncytostatic concentrations of IFN-alpha down-regulated the activity of MMP-9, up-regulated E-cadherin, and inhibited in vitro invasion. 253J B-V(R) cells were implanted into the bladders of athymic nude mice. Systemic therapy with IFN-alpha (10,000 units s.c. daily) decreased the expression of MMP-9, increased expression of E-cadherin, reduced tumor volume, and inhibited metastasis. The MMP-9:E-cadherin ratio was 4.5 in untreated controls and 1.1 after IFN-alpha treatment. Moreover, systemic low-dose daily IFN-alpha potentiated the efficacy of paclitaxel. These studies indicate that in addition to its antiproliferative and antiangiogenic effects, IFN-alpha limits tumor invasion by restoring the normal balance between MMP-9 and E-cadherin and enhances the activity of systemic chemotherapy.

Adenoviral-mediated gene therapy of human bladder cancer with antisense interleukin-8

We previously demonstrated the importance of interleukin-8 (IL-8) as a mediator of angiogenesis, tumorigenicity, and metastasis of transitional cell carcinoma (TCC) of the bladder. In the present study, we evaluated the feasibility of adenoviral mediated antisense IL-8 gene transfer (Ad IL-8-AS) as therapy for established TCC. In vitro, Ad IL-8-AS inhibited endothelial cell proliferation and enhanced endothelial cell apoptosis. The highly metastatic human TCC cell line 253J B-V(R) was implanted into the subcutis of athymic nude mice, and intralesional therapy with Ad IL-8-AS commenced when the tumors reached a diameter between 5 and 7 mm. Tumor growth was significantly inhibited compared with therapy in controls (saline and beta-galactosidase adenovirus). Ad IL-8-AS therapy decreased the in vivo expression of IL-8 and matrix metalloproteinase type 9 (MMP-9), reduced microvessel density, and enhanced endothelial cell apoptosis. These results indicate that Ad IL-8-AS therapy targets both tumor cells and host endothelial cells resulting in endothelial cell apoptosis and significant inhibition of tumor growth.

An autoradiographic study of regional blood flow distribution in the rat kidney during ureteric obstruction--the role of vasoactive compounds

OBJECTIVE

To determine the changes in regional renal blood flow during ureteric obstruction and to examine the role of vasoactive mediators in effecting these changes.

MATERIALS AND METHODS

Renal blood flow in Sprague-Dawley rats was assessed after periods of ureteric obstruction using a quantitative autoradiographic technique based on Kety's theory of diffusion of an inert tracer (14C-iodoantipyrine). Prostaglandins, thromboxanes and renin-angiotensin were inhibited pharmacologically using diclofenac sodium and enalapril.

RESULTS

Baseline blood flow to the outer cortex, inner cortex and medulla was 807, 258 and 105 mL/100 g/min, respectively. There was an increase in outer cortical blood flow after 10 min of ureteric obstruction which became significant at 30 min (P < 0.05). There was a significant decrease in inner cortical and medullary blood flow at 30 min, to 210 and 68 mL/100 g/min, respectively (P < 0.05). Diclofenac sodium abolished the increase in outer cortical blood flow. After 24 h of unilateral ureteric obstruction, outer cortical blood flow decreased to 492 mL/100 g/min; inner cortical blood flow also decreased but to a lesser extent, to 190 mL/100 g/min. Inhibition of prostaglandins, thromboxanes and the renin-angiotensin system reduced the degree of renal vasoconstriction but there was still a significant decrease in outer cortical perfusion despite the presence of these blocking agents.

CONCLUSIONS

The control of the renal vasculature involves a complex interplay between a variety of vasoactive mediators. Quantitative autoradiography offers the opportunity to evaluate changes in regional renal perfusion with high resolution and will allow a greater understanding of the pathophysiology of renal diseases.

Nitric oxide in unilateral ureteral obstruction: effect on regional renal blood flow

BACKGROUND

Ureteral obstruction (UO) is characterized by reduced blood flow and loss of tissue mass in the involved kidney(s). Vasoactive mediators interact to produce an initial hyperemia, followed by a sustained decrease in renal blood flow in the obstructed kidney. Nitric oxide (NO) has been shown to play a central role in the acute hyperemic response to UO. Its role in the reduced perfusion of prolonged UO is less studied.

METHODS

Ureteral obstruction was achieved by ligation of the distal left ureter and maintained for 24 hours. Blood flow was studied in untreated animals and after the administration of the NO synthase (NOS) inhibitor N-mono-methyl L-arginine and the NO donor sodium nitroprusside. Tissue was collected for localization and quantitation of NOS. Serum and renal tissue L-arginine levels were measured in control and UO settings.

RESULTS

Blood flow in the obstructed kidney diminished to approximately 50% of control values after 24 hours of UO. NOS blockade led to a further decrease in blood flow. Supplementation with exogenous nitrates restored renal blood flow to levels approaching control values. Serum and tissue L-arginine levels did not change with UO. NOS expression was seen to increase with increasing duration of obstruction, with staining most pronounced in the renal tubules.

CONCLUSIONS

NO plays a vasodilatory role even in the hypoperfusion of prolonged UO. The administration of exogenous nitrates has a restorative effect on blood flow, suggesting therapeutic potential in UO.

The prognostic value of angiogenesis factor expression for predicting recurrence and metastasis of bladder cancer after neoadjuvant chemotherapy and radical cystectomy

To determine the prognostic value of angiogenesis factor expression for patients with muscle-invasive transitional cell carcinoma (TCC) of the bladder treated with neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC) chemotherapy and radical cystectomy, we evaluated the expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and interleukin 8 (IL-8) by in situ hybridization, and we determined microvessel density (MVD) by immunohistochemistry. These factors were evaluated in 55 biopsy specimens prior to therapy and in the cystectomy specimens of 51 patients after completion of therapy. By univariate analysis, VEGF expression and MVD in the biopsy specimens were significant predictors of disease recurrence. By multivariate analysis, only VEGF expression was an independent prognostic factor. Pathological stage, bFGF expression, and MVD in the cystectomy specimens after therapy were all independent prognostic factors for disease recurrence. The results of this exploratory study indicate that the expression levels of VEGF and bFGF as indicated by in situ hybridization and MVD as indicated by immunohistochemistry identify patients with muscle-invasive TCC who are at high risk of developing metastasis after aggressive therapy with systemic M-VAC chemotherapy and radical cystectomy.

Paclitaxel enhances the effects of the anti-epidermal growth factor receptor monoclonal antibody ImClone C225 in mice with metastatic human bladder transitional cell carcinoma

Previously we reported that when cells from the human transitional cell carcinoma cell line 253J B-V growing orthotopically within the bladder of athymic nude mice were treated with the anti-epidermal growth factor receptor monoclonal antibody C225, angiogenesis was inhibited, resulting in regression of the primary tumor and inhibition of metastasis. In this study, we evaluated whether paclitaxel enhanced this therapeutic effect of C225. In vitro, the proliferation of 253J B-V cells was inhibited more by the combination of C225 and paclitaxel than with either agent alone. In vivo therapy with C225 and paclitaxel resulted in significantly greater regression of tumors compared with either agent alone. Median bladder tumor weight was 85 mg (range, 69-133 mg) compared with 168 mg (range, 72-288 mg) after C225 alone (P < 0.05), and 273 mg (range, 83-563 mg) after paclitaxel alone (P < 0.005). The incidence of spontaneous lymph node metastasis was also reduced by the combination of C225 with paclitaxel, although this result did not significantly differ from results after the use of C225 alone. Treatment with paclitaxel and C225 down-regulated the expression of basic fibroblast growth factor, vascular endothelial cell growth factor, interleukin-8, and matrix metalloproteinase type 9 and inhibited tumor-induced neovascularity compared with untreated controls (P < 0.005). Moreover, the combination of C225 and paclitaxel enhanced apoptosis in tumor and endothelial cells compared with either agent alone (P < 0.005). These studies indicate that therapy with paclitaxel increases the ability of C225 to inhibit tumorigenicity and metastasis. This effect is mediated by inhibition of angiogenesis and induction of apoptosis.

Gene therapy of human bladder cancer with adenovirus-mediated antisense basic fibroblast growth factor

We previously investigated the role of basic fibroblast growth factor (bFGF) as a mediator of angiogenesis, tumorigenicity, and metastasis of transitional cell carcinoma (TCC) of the bladder. In the present study, we determined whether adenoviral-mediated antisense bFGF gene transfer therapy (Ad bFGF-AS) would inhibit TCCs growing in the subcutis of nude mice. In vitro, Ad bFGF-AS inhibited endothelial cell proliferation and enhanced apoptosis. The highly metastatic human TCC cell line 253J-BV(R) was implanted ectopically in the subcutis of athymic nude mice, and therapy was begun when the tumors reached a diameter between 5 and 7 mm. Intralesional therapy with Ad bFGF-AS decreased the in vivo expression of bFGF and matrix metalloproteinase type 9 mRNA and protein, and reduced microvessel density and enhanced endothelial cell apoptosis. Tumor growth was significantly inhibited by Ad bFGF-AS (mean, 58 mg) compared with controls [saline (mean, 562 mg), beta-galactosidase adenovirus (mean, 586 mg), and sense bFGF adenoviral therapy (Ad bFGF-S; mean, 3012 mg)]. These results suggest that Ad bFGF-AS therapy affects endothelial cells directly and tumor cells indirectly through down-regulation of bFGF and matrix metalloproteinase type 9, resulting in endothelial cell apoptosis and significant tumor growth inhibition. Furthermore, these studies confirm that bFGF expression is a valid target for the therapy of bladder cancer.

Ad5CMVp53 gene therapy for locally advanced prostate cancer--where do we stand?

Despite the introduction of screening procedures and an increased public awareness of prostate cancer, a substantial number of patients present with locally advanced prostate cancer. Traditional therapies (such as radiation therapy or radical prostatectomy) applied either alone or in combination fail to control local disease in a large number of cases and have no effect on disseminated disease. Recent advances in molecular oncology and genetics have led to such novel therapies as p53 gene therapy, which we are currently evaluating in a clinical protocol in patients with locally advanced (nonmetastatic) prostatic cancer. Ad5CMVp53 (RPR/INGN 201) has previously shown promise in both patients with lung cancer and those with head and neck cancer. The traditional end points used to appraise prostate cancer preclude rapid evaluation of the patient's disease and prevent modification of the therapeutic strategy, and we suggest that the pathologic stage after therapy be evaluated as an intermediate end point.

Effective induction of HIV-specific CTL by multi-epitope using gene gun in a combined vaccination regime

Reliable and effective induction of cytotoxic T-lymphocytes (CTL) is one of the prime objectives of vaccine research. Previously, novel HIV vaccine candidates were constructed as a string of CTL epitopes (20 human, 3 macaque and 1 mouse) delivered using a DNA vector [Hanke T, Schneider J, Gilbert SG, Hill AVS, McMichael A. DNA multi-CTL epitope vaccines for HIV and Plasmodium falciparum: immunogenicity in mice. Vaccine 1998;16:426-435.] or modified vaccinia Ankara (MVA [Hanke T, Blanchard TJ, Schneider J, Ogg GS, Tan R, Becker MSC, Gilbert SG, Hill AVS, Smith GL, McMichael A. Immunogenicities of intravenous and intramuscular administrations of MVA-based multi-CTL epitope vaccine for HIV in mice. J Gen Virol 1998;79:83-90.]), i.e. vaccine vehicles acceptable for use in humans. In mice, a single intramuscular (i.m.) needle injection of either vaccine alone elicited good CTL responses. Here, it is demonstrated that the multi-epitope DNA also induced CTL when delivered intradermally using the Accell gene gun. The CTL responses increased after re-immunization and after three deliveries were comparable to those induced by a single i.m. injection. Recent evidence indicates that combining routes and vaccine vehicles enhances the immunogenicity of vaccine-delivered or -encoded antigens. Here, it is shown that administration of DNA by an i.m. priming/gene gun boosting more efficiently induced CTL than gene gun priming/i.m. boosting. A similar increment was obtained by sequential vaccinations using a gene gun-delivered DNA followed by recombinant MVA. Thus particular sequences of routes or vaccine vehicles rather than simple prime-boost delivery of a single vaccine is critical for an effective elicitation of CTL.

Changes in regional renal blood flow after unilateral nephrectomy using the techniques of autoradiography and microautoradiography

PURPOSE

To determine alterations in regional renal blood flow following unilateral nephrectomy using an autoradiographic technique. The role of prostaglandins and the sympathetic nervous system in the mediation of these changes was assessed.

MATERIALS AND METHODS

C-14 iodoantipyrine was used as a tracer to measure intrarenal blood flow in anaesthetised rats at multiple time points following nephrectomy. Autoradiographs were produced from tissue sections. C-14 concentrations were measured from standards thus allowing blood flow values to be calculated.

RESULTS

Base line values for cortical and medullary blood flow were 806 +/- 63 and 373 +/- 39 ml./100 gm./min. (mean +/- SEM) respectively. At 2 hours post nephrectomy blood flow to both the cortex and medulla increased significantly (1152 +/- 54 and 594 +/- 37; p < 0.05). Blood flow had returned to control levels by 24 hours and was maintained at 5 days post-nephrectomy. Multiple discrete regions of high blood flow within the cortex were observed. Microautoradiography defined the morphological location of these discrete regions of higher blood flow as periglomerular vasculature. Diclofenac administration did not inhibit the augmentation in cortical blood flow post-nephrectomy, while medullary blood flow fell below base line values at both 30 minutes and 2 hours following nephrectomy. Sympathetic denervation did not affect the changes in cortical blood flow seen following nephrectomy, but did ameliorate the changes in medullary blood flow.

CONCLUSIONS

Significant, transient changes in regional renal blood flow occur in the residual kidney following unilateral nephrectomy. The interaction between vasoactive mediators and the autonomic nervous system which produces changes in cortical blood flow is complex. It is evident, however, that medullary blood flow is dependent on local prostaglandin production and is also influenced by sympathetic nervous supply.

Changes in regional renal blood flow after unilateral nephrectomy using the techniques of autoradiography and microautoradiography

PURPOSE

To determine alterations in regional renal blood flow following unilateral nephrectomy using an autoradiographic technique. The role of prostaglandins and the sympathetic nervous system in the mediation of these changes was assessed.

MATERIALS AND METHODS

C-14 iodoantipyrine was used as a tracer to measure intrarenal blood flow in anaesthetised rats at multiple time points following nephrectomy. Autoradiographs were produced from tissue sections. C-14 concentrations were measured from standards thus allowing blood flow values to be calculated.

RESULTS

Base line values for cortical and medullary blood flow were 806 +/- 63 and 373 +/- 39 ml./100 gm./min. (mean +/- SEM) respectively. At 2 hours post nephrectomy blood flow to both the cortex and medulla increased significantly (1152 +/- 54 and 594 +/- 37; p < 0.05). Blood flow had returned to control levels by 24 hours and was maintained at 5 days post-nephrectomy. Multiple discrete regions of high blood flow within the cortex were observed. Microautoradiography defined the morphological location of these discrete regions of higher blood flow as periglomerular vasculature. Diclofenac administration did not inhibit the augmentation in cortical blood flow post-nephrectomy, while medullary blood flow fell below base line values at both 30 minutes and 2 hours following nephrectomy. Sympathetic denervation did not affect the changes in cortical blood flow seen following nephrectomy, but did ameliorate the changes in medullary blood flow.

CONCLUSIONS

Significant, transient changes in regional renal blood flow occur in the residual kidney following unilateral nephrectomy. The interaction between vasoactive mediators and the autonomic nervous system which produces changes in cortical blood flow is complex. It is evident, however, that medullary blood flow is dependent on local prostaglandin production and is also influenced by sympathetic nervous supply.

The role of ATP citrate-lyase in the metabolic regulation of plasma lipids. Hypolipidaemic effects of SB-204990, a lactone prodrug of the potent ATP citrate-lyase inhibitor SB-201076

ATP citrate (pro-S)-lyase (EC 4.1.3.8), a cytosolic enzyme that generates acetyl-CoA for cholesterol and fatty acid synthesis de novo, is a potential target for hypolipidaemic intervention. Here we describe the biological effects of the inhibition of ATP citrate-lyase on lipid metabolism in Hep G2 cells, and plasma lipids in rats and dogs, by using SB-204990, the cell-penetrant gamma-lactone prodrug of the potent ATP citrate-lyase inhibitor SB-201076 (Ki=1 microM). Consistent with an important role of ATP citrate-lyase in the supply of acetyl-CoA units for lipid synthesis de novo, SB-204990 inhibited cholesterol synthesis and fatty acid synthesis in Hep G2 cells (dose-related inhibition of up to 91% and 82% respectively) and rats (76% and 39% respectively). SB-204990, when administered orally to rats, was absorbed into the systemic circulation; pharmacologically relevant concentrations of SB-201076 were recovered in the liver. When administered in the diet (0.05-0. 25%, w/w) for 1 week, SB-204990 caused a dose-related decrease in plasma cholesterol (by up to 46%) and triglyceride levels (by up to 80%) in rats. This hypolipidaemic effect could be explained, at least in part, by a decrease (up to 48%) in hepatic very-low-density lipoprotein (VLDL) production as measured by the accumulation of VLDL in plasma after injection of Triton WR-1339. SB-204990 (25 mg/kg per day) also decreased plasma cholesterol levels (by up to 23%) and triglyceride levels (by up to 38%) in the dog, preferentially decreasing low-density lipoprotein compared with high-density lipoprotein cholesterol levels. Overall these results are consistent with the concept that ATP citrate-lyase is an important enzyme in controlling substrate supply for lipid synthesis de novo and a potential enzyme target for hypolipidaemic intervention.

Epididymectomy in the management of intrascrotal disease: a critical reappraisal

OBJECTIVE

To assess the outcome of epididymectomy as a method of treating epididymal pathology.

PATIENTS AND METHODS

Forty-one patients who underwent epididymectomy between 1990 and 1995 were analysed retrospectively; their clinical records were reviewed and their satisfaction with the outcome and relief of symptoms assessed using a questionnaire and/or telephone interview.

RESULTS

Twenty-nine patients with pain were subdivided into three categories depending on the indication for epididymectomy, i.e. post-vasectomy epididymal engorgement (eight patients), complex cystic disease (11) or 'chronic epididymitis' (10). The outcome was satisfactory in 27 of the 29 patients. The best results were obtained in the group who underwent epididymectomy after vasectomy, where seven of eight improved after the procedure. Those with chronic epididymitis had the least favourable outcome, with only seven reporting any improvement in symptoms.

CONCLUSIONS

Epididymectomy has a valuable role in the management of epididymal pathology in appropriately selected patients.

An intraoral positioning appliance for stereotactic radiotherapy

Stereotactic radiotherapy provides the most accurate and effective therapy and protects the adjacent, normal tissues. The head must be positioned the same for all treatments. This article describes the fabrication and application of a noninvasive intraoral appliance that verifies the position of the head to deliver more accurate radiotherapy and protect the adjacent, normal tissues.

Quantitative imaging study of extent of surgical resection and prognosis of malignant astrocytomas

OBJECTIVE

This study used quantitative radiological imaging to determine the effect of surgical resection on postoperative survival of patients with malignant astrocytomas. Previous studies relied on the surgeons' impressions of the amount of tumor removed, which is a less reliable measure of the extent of resection.

METHODS

Information concerning possible prognostic factors was collected for 75 patients undergoing magnetic resonance imaging or computed tomography preoperatively and within 10 days postoperatively. Image analysis of the neuroradiological studies was conducted to quantify pre- and postoperative total tumor volumes and enhancing volumes. Univariate and multivariate proportional hazards models were used to analyze the regression of survival regarding 22 covariates that might affect survival. The covariates that were entered included age, gender, tumor grade, cumulative radiation dose, chemotherapy, seizures as a first symptom, Karnofsky performance status at presentation, pre- and postoperative total and enhancing tumor volumes, ratio of pre- to postoperative total and enhancing tumor volumes, tumor location, surgeon's impression of the degree of resection, and subsequent surgery.

RESULTS

There were 23 patients with anaplastic astrocytomas and 52 with glioblastomas multiforme. The estimated mean survival time was 27 months for patients undergoing gross total resection, 33 months for subtotal resection, and 13 months for open or stereotactic biopsy. Five factors that were significant predictors of survival in multivariate analysis were tumor grade, age, Karnofsky performance status, radiation dose, and postoperative complications (P < 0.05). In univariate analysis, tumor grade, radiation dose, age, Karnofsky status, complications, presence of enhancing tumor in postoperative imaging, and postoperative volume of enhancing tumor were significantly associated with survival (P < 0.05).

CONCLUSION

We conclude that the most important prognostic factors affecting survival of patients with anaplastic astrocytomas and glioblastomas multiforme are tumor grade, age, preoperative performance status, and radiation therapy. Postoperative complications adversely affect survival. Aggressive surgical resection did not impart a significant increase in survival time. Surgical resection may improve survival, but its importance is less than that of other factors and may be demonstrable only by larger studies.

Neutrophil maturation of CD34+ cells from peripheral blood and bone marrow in serum-free culture medium with PIXY321 and granulocyte-colony stimulating factor (G-CSF)

Bone marrow (BM) or peripheral blood (PB) CD34+ cells were cultured for 12 days in serum-free culture medium containing PIXY321 (IL-3/ GM-CSF fusion protein) with or without periodic supplements of granulocyte-colony stimulating factor (G-CSF). The cultures were evaluated at day 12 for total cell proliferation (fold increase from day 0), neutrophil differentiation by flow cytometry, using dual staining with CD15-FITC and CD11b-PE, and morphology using Wright-Giemsa and granule staining. In cultures containing PIXY321 where 6000 U/ml of G-CSF was added days 0 and 6, there was no significant difference (p > or = 0.05) in cell proliferation or the percent of CD15+/CD11b+ cells when compared with cultures with PIXY321 alone. ELISA analysis showed G-CSF levels had declined by 90% after 3 days of culture. Further studies were performed to assess the benefit of supplementing lower concentrations of G-CSF (600 U/ml) at more frequent intervals. A significant increase (p < or = 0.05) in cell proliferation and percent CD15+/CD11b+ was observed when G-CSF was added on days 0, 3, 6, and 9 (every 3 days) as compared with those cultures with PIXY321 alone. CD34+ cell proliferation without G-CSF was 19.6 +/- 4.8-fold, with G-CSF added on days 0 and 6 was 28.7 +/- 6.4-fold, and with G-CSF added on days 0, 3, 6, and 9 was 45.9 +/- 10.6-fold. Percent of CD15+/CD11b+ cells was 19.0 +/- 4.6%, 38.2 +/- 7.2%, and 58.5 +/- 6.5%, respectively, in these cultures. We observed more CD15+/CD11b+ cells, myelocytes/metamyelocytes, and secondary granule staining in cultures with G-CSF added on day, 0, 3, 6, and 9 as compared with cultures with G-CSF added on days 0 and 6 or no G-CSF added. We conclude that PIXY321 and G-CSF act synergistically on the in vitro proliferation and neutrophil differentiation of BM and PB CD34+ cells and that frequent supplements of G-CSF facilitate neutrophil differentiation.

The effect of tramadol on dento-alveolar surgical pain

The aim of the study was to assess the analgesic effect of tramadol in the relief of pain after dentoalveolar operations that involve the removal of bone and suturing. Four-hundred and fifty-two patients over the age of 18 years who were to undergo removal of impacted teeth (n = 362), removal of root (n = 79), or alveolectomy, enucleation of cysts, or removal of soft tissue (n = 11) under local anesthesia were studied. Patients were randomly allocated to receive tramadol 100 mg or 50 mg four times daily, or 50 mg twice daily, or placebo. Median pain scores on the day of operation in the three tramadol groups were similar (2 in each group, ranges 1-5, 1-4.8, and 1-5 respectively) and were all significantly lower than that in the placebo group (2.3 range 1-4.2). The median number of Paracetamol tablets taken by patients in the three tramadol groups was 2 (ranges 0-8, 0-12 and 0-8 respectively), and were all significantly less than in the placebo group (4, range 0-12). More patients given tramadol reported complete pain relief than the placebo group. The advantages of tramadol continued over the next 2 days. There were no serious or unexpected adverse effects. It is concluded that tramadol is an effective analgesic after dentoalveolar operations.

Late rectal sequelae following definitive radiation therapy for carcinoma of the uterine cervix: a dosimetric analysis

PURPOSE

This study attempted to correlate patient, treatment, and dosimetric factors with the risk of late rectal sequelae in patients treated with radiation therapy (RT) for cervical carcinoma.

METHODS AND MATERIALS

A total of 183 patients with cervical carcinoma (67 Stage I, 93 Stage II, and 23 Stage III) treated with definitive RT with a minimum of 2 years follow-up were evaluated. Treatment consisted of external beam pelvic RT (EBRT) followed by intracavitary RT (ICRT) consisting of one or two insertions. Complications were scored and analyzed as a function of 25 patient and treatment factors. Conventional total rectal doses were obtained by adding together the EBRT and ICRT rectal doses. To account for differences in dose rate between the ICRT and EBRT, and variations in EBRT fractionation schemes, biologically equivalent rectal doses (BED) were calculated using a linear quadratic model. In addition, the influence of the varying proportions of EBRT and ICRT rectal doses were evaluated.

RESULTS

Twenty-eight patients (15.3%) developed late rectal sequelae (13 Grade 1, 3 Grade 2, and 12 Grade 3). Diabetes (p = 0.03), Point A dose (p = 0.04), and conventional EBRT dose (p = 0.03) were the most significant factors on multivariate analysis. Logistic regression analysis demonstrated a low risk (<10%) of late rectal sequelae below conventional and biological rectal doses of 75 Gy and 135 BED, respectively. The percentage of rectal dose delivered by the EBRT significantly influenced the dose-response relationship. A defined threshold percentage above which rectal sequelae were more common was identified over the range of doses evaluated. This threshold was 87% at a total rectal dose of 60 Gy and decreased to 60% at 80 Gy.

CONCLUSION

Diabetes, Point A, and EBRT doses are the most significant factors associated with the risk of late rectal sequelae in patients treated with RT for cervical carcinoma. The percentage of rectal dose delivered by the EBRT significantly affects the conventional and biological dose-response relationship. This suggests that the volume of rectum irradiated is an important and independent parameter in the development of late rectal sequelae.

Localization of the prostatic apex for radiotherapy planning: a comparison of two techniques

Autopsy and pathology studies have shown that the caudal portion of the prostate gland harbors tumour in 64-75% of specimens examined. Accurate localization of the prostatic apex may be important in improving local control with external beam radiation therapy. We compared the location of the apex obtained with CT based treatment planning versus localization using retrograde urethrography in 32 consecutive patients. The prostatic apex, localized by CT and retrograde urethrography, was compared relative to the ischial tuberosities and the symphysis pubis. Discordance between the location of the prostatic apex as defined on CT scan and retrograde urethrography was found in 50% of patients evaluated. There was 31% discordance between the location of the prostatic apex as defined on CT and retrograde urethrography when data were analysed with the location of the prostatic apex 1 cm above the narrowing on urethrography, a definition others have suggested. The urethrogram defined prostatic apex, as compared with the CT definition, necessitated the treatment of more of the surrounding normal tissues in 31% of our cases, with four-field techniques. Comparison of dose-volume histograms of the bladder, rectum and penis irradiated for target volumes defined by CT versus retrograde urethrography showed that more penis was irradiated in some patients with the urethrogram defined prostatic apex; irradiation of the base of the penis could be relatively avoided by using a six-field treatment plan instead of the standard four-field box. There is discordance between the CT and urethrogram defined prostatic apex. Dose-volume histogram information suggests that differences in apex localization can significantly affect doses to normal adjacent prostatic tissues. Combining CT localization with the urethrogram localization of the prostatic apex optimizes radiotherapy planning and dose delivery.

Multimodal-therapy breast salvage in the urban poor with locally advanced cancer

OBJECTIVES

To determine whether economically disadvantaged urban women with locally advanced breast cancer (American Joint Committee on Cancer stages IIB to IIIB) have rates of response to sequential neoadjuvant chemotherapy and radiation, breast salvage rates, overall survival rates, and disease-free survival rates comparable with those previously reported in other socioeconomic groups and to compare these variables in different ethnic groups within the study population.

DESIGN

Prospective, nonrandomized, case series.

SETTING

Urban county hospital.

PATIENTS

Thirty-seven women with locally advanced breast cancer who came to the breast clinic at Cook County Hospital, Chicago, Ill, during a 3-year interval.

INTERVENTION

Sequential chemoradiation followed by surgery in selected patients.

MAIN OUTCOME MEASURES

Comparison of clinical response rates, disease-free survival rates, and breast salvage rates between different ethnic groups in the study population.

RESULTS

In the entire group, the overall response rate to neoadjuvant chemotherapy was 73%, with a complete response rate of 32%. Twenty-five percent of patients whose tumors responded incompletely to chemotherapy had a complete response after subsequent radiation. With a mean follow-up of 18.7 months, 65% of patients had no evidence of disease, and breast salvage without evidence of recurrent disease was achieved in 38% of patients. No differences in overall response rates, breast salvage rates, or early disease-free survival rates were observed within different ethnic groups in the study population, and these results are generally comparable with previously reported results in other socioeconomic groups.

CONCLUSION

These results do not show significant differences in responses to sequential chemotherapy and irradiation, in breast salvage rates, or in survival between different ethnic groups in this study population.

Comparison of static conformal field with multiple noncoplanar arc techniques for stereotactic radiosurgery or stereotactic radiotherapy

PURPOSE

Compare the use of static conformal fields with the use of multiple noncoplanar arcs for stereotactic radiosurgery or stereotactic radiotherapy treatment of intracranial lesions. Evaluate the efficacy of these treatment techniques to deliver dose distributions comparable to those considered acceptable in current radiotherapy practice.

METHODS AND MATERIALS

A previously treated radiosurgery case of a patient presenting with an irregularly shaped intracranial lesion was selected. Using a three-dimensional (3D) treatment-planning system, treatment plans using a single isocenter multiple noncoplanar arc technique and multiple noncoplanar conformal static fields were generated. Isodose distributions and dose volume histograms (DVHs) were computed for each treatment plan. We required that the 80% (of maximum dose) isodose surface enclose the target volume for all treatment plans. The prescription isodose was set equal to the minimum target isodose. The DVHs were analyzed to evaluate and compare the different treatment plans.

RESULTS

The dose distribution in the target volume becomes more uniform as the number of conformal fields increases. The volume of normal tissue receiving low doses (> 10% of prescription isodose) increases as the number of static fields increases. The single isocenter multiple arc plan treats the greatest volume of normal tissue to low doses, approximately 1.6 times more volume than that treated by four static fields. The volume of normal tissue receiving high (> 90% of prescription isodose) and intermediate (> 50% of prescription isodose) doses decreases by 29 and 22%, respectively, as the number of static fields is increased from four to eight. Increasing the number of static fields to 12 only further reduces the high and intermediate dose volumes by 10 and 6%, respectively. The volume receiving the prescription dose is more than 3.5 times larger than the target volume for all treatment plans.

CONCLUSIONS

Use of a multiple noncoplanar conformal static field treatment technique can significantly reduce the volume of normal tissue receiving high and intermediate doses compared with a single isocenter multiple arc treatment technique, while providing a more uniform dose in the target volume. Close conformation of the prescription isodose to the target volume is not possible using static uniform conformal fields for target shapes lacking an axis of rotational symmetry or plane of mirror symmetry.

Photon neutron mixed-beam radiotherapy of locally advanced prostate cancer

PURPOSE

In this article we present the results of mixed-beam, photon/neutron radiation therapy in 45 patients with locally advanced, bulky, or postoperative recurrent prostate cancer treated at the University of Chicago between 1978 and 1991. Survival, disease-free survival, local control, and long-term complications are analyzed in detail.

METHODS AND MATERIALS

Between 1978 and 1991, 45 patients with locally advanced (> 5 cm State B2, Stage C, or Stage D1) prostate cancer underwent mixed-beam (photon/neutron) radiation therapy. Forty percent of the treatment was delivered with neutron irradiation at either the University of Chicago or Fermilab. Sixty percent of treatment was delivered with photons at the University of Chicago. Initially, the whole pelvis was irradiated to 50 photon Gy equivalent. This was followed by a boost to the prostate for an additional 20 photon Gy equivalent.

RESULTS

The median follow-up for patients in this series is 72 months. The overall 5-year actuarial survival was 72%, and the 5-year disease-free survival was 45%. Thus far, 18 patients have died. Eleven patients have died from prostate cancer and 7 from other medical illness. Twenty-seven patients are alive, and 12 of these patients have recurrent and or metastatic disease. The local control rate was 89% (40 out of 45). Histologic material was available on 18 patients following treatment (i.e., prostate biopsy in 16 patients and autopsy in 2 patients) and was negative for carcinoma in 13 (72%). Significant Grade 3-5 complications occurred in 36% (16 out of 45) of the patients treated with mixed-beam radiation therapy and were related to dose and beam quality. Factors related to survival, disease-free survival, local control, and complications are analyzed.

CONCLUSIONS

The survival and local control results of mixed-beam radiation therapy at the University of Chicago appear to be superior to those series using photon radiation in patients with locally advanced prostate carcinoma. Mixed-beam radiation therapy should remain an alternative to studies using dose escalation or implant techniques as a method to increase local control and survival at institutions with this capability. However, appropriate plans with high-energy neutrons are necessary to minimize complications.

Hydroxyurea with continuous infusion paclitaxel, 5-fluorouracil, and concomitant radiotherapy for poor-prognosis head and neck cancer

Concomitant chemoradiotherapy holds promise in the therapy of advanced head and neck cancer. We have previously reported on the combination of 5-fluorouracil, hydroxyurea, and concomitant chemoradiotherapy administered on an alternate-week basis. In this ongoing study, we are testing the feasibility of adding continuous-infusion paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) to this combination. Background information and early clinical data are presented.

Teenagers at risk of human immunodeficiency virus type 1 infection. Results from seroprevalence surveys in the United States

OBJECTIVE

To describe the seroprevalence of human immunodeficiency virus type 1 (HIV-1) and risk factors for HIV-1 infection among teenagers attending selected clinics.

DESIGN

Anonymous, cross-sectional serosurveys conducted in 130 clinics in 24 cities.

SETTINGS

Adolescent medicine clinics, sexually transmitted disease clinics, clinics in juvenile detention and correctional facilities, and homeless and runaway youth centers.

PATIENTS

Teenagers in whom serum samples were drawn as part of routine medical services.

MAIN OUTCOME MEASURES

Prevalence of HIV-1 infection and reported HIV risk behaviors.

RESULTS

From January 1, 1990 through December 31, 1992, serum specimens were collected from 79,802 teenagers; 591 of these specimens were positive for HIV-1 antibody. Seropositive test results were found in all 24 cities surveyed, and in 95 (73%) of the 130 clinics surveyed. The median clinic-specific prevalence was 0.2% (range, 0% to 1.4%) in 22 adolescent medicine clinics, 0.3% (range, 0% to 6.8%) in 33 correctional facilities, 0.5% (range, 0% to 3.5%) in 70 sexually transmitted disease clinics, and 1.1% (range, 0% to 4.1%) in five homeless youth centers. Rates exceeded 1% in 37 sites (28%). Excluding sites with many men reporting sex with men, rates in women were similar or somewhat higher than rates in men. Rates were highest among young men reporting sex with men, with clinic rates ranging from 16% to 17% in two homeless youth sites and 13% to 17% in two sexually transmitted disease clinics. Most teenagers with risk information reported heterosexual activity as their only potential risk exposure to HIV-1.

CONCLUSIONS

Seroprevalence of HIV was generally low but varied by type of clinic and geographic area. The highest rates were observed among young women and gay men in some settings, suggesting that targeted prevention messages are needed.

Partial cystectomy

Partial cystectomy remains an uncommonly performed procedure in the urologist's armamentarium. Historically, it has had a limited role in the treatment of bladder cancer because of the variable reported success rate and because of the high success rate of local endoscopic excision. When patients with muscle-invasive lesions are appropriately selected, 5-year survival rates following partial cystectomy approximate those of radical cystectomy in the treatment of transitional-cell carcinoma while preserving a physiologically functioning bladder. Therefore, not only does partial cystectomy represent a valuable treatment option, but it appears to be the procedure of choice for local muscle-invasive transitional-cell carcinoma of the bladder when careful selection criteria are utilized. Future studies are needed to define its precise role in affording bladder preservation when used in association with adjuvant chemotherapy. Partial cystectomy also remains a surgical option for a variety of less common benign and malignant lesions of the bladder.

The future of healthcare. Seven experts look ahead

If there were ever a time to have a crystal ball, it's now. In today's healthcare environment the only thing that seems certain is change. To help marketers make some educated guesses about the future of healthcare, hospitals, and the market, PROFILES invited seven experts to prognosticate. They considered what might happen in this decade, and what could be reality in 25 to 50 years. They address topics ranging from surgery of the future to how consumers will find healthcare information. Here are a few of their predictions: 1. Managed care will dominate the market. 2. More hospitals will close. Those remaining will consolidate or collaborate and draw closer to their communities. 3. Doctors and hospitals will build partnerships. More doctors will be salaried. 4. Cost controls will increase. 5. Quality will differentiate hospitals and drive marketing. 6. Patients will become more involved in their care and in their selection of hospitals. 7. Drug treatments will play an increased role as surgery declines.