TG01/GM-CSF and adjuvant gemcitabine in patients with resected RAS-mutant adenocarcinoma of the pancreas (CT TG01-01): a single-arm, phase 1/2 trial

BACKGROUND

TG01 is the first cancer immunotherapy targeting KRAS oncogenic mutations. This study assessed the safety and efficacy of TG01/GM-CSF in patients with resected pancreatic adenocarcinoma.

METHODS

Patients with stage I or II pancreatic adenocarcinoma who had undergone surgical resection (R0 or R1) received adjuvant gemcitabine with TG01/GM-CSF using two schedules of vaccination. Immune response was defined as a positive delayed-type hypersensitivity (DTH) response and/or positive T-cell proliferation assay.

RESULTS

Thirty-two patients were enrolled between February 2013 and May 2016. Nineteen were treated with the high antigen burden, with four serious adverse reactions considered possibly related to TG01 treatment, including three allergic reactions. On this basis, a further 13 patients received a modified vaccination schedule with reduced antigen burden, with no serious adverse events related to TG01. Ninety-five percent patients in the main cohort and 92% in the modified cohort had a positive immune response. Median overall survival (OS) was 33.1 months, and median disease-free survival (DFS) was 13.9 months for the main cohort. For the modified cohort, the median OS was 34.3 months and median DFS was 19.5 months.

CONCLUSIONS

TG01/GM-CSF with gemcitabine was well tolerated, with high levels of immune activation. OS and DFS compare favourably with published data for adjuvant gemcitabine.

CLINICAL TRIAL REGISTRATION

This clinical trial was registered at ClinicalTrials.gov (NCT02261714).

Abstract A022: Phase 1/2 study to evaluate systemic durvalumab (durva) + intraperitoneal ONCOS-102 in patients with peritoneal disease who have epithelial ovarian (OC) or metastatic colorectal cancer (CRC)

Metastasis to the peritoneal cavity is associated with end-stage disease in many cancers, including epithelial ovarian cancer (OC) and colorectal cancer (CRC), both of which exhibit poor responses to checkpoint inhibitors. Oncolytic viruses may promote tumor recognition by the immune system. Evidence suggests that locoregional treatment with oncolytic viruses can be used to improve the efficacy of checkpoint inhibitors at both treated and distant tumor sites. ONCOS-102 is an oncolytic adenovirus encoding for granulocyte-macrophage colony stimulating factor (GMCSF). Durvalumab (durva), a checkpoint inhibitor, is a human IgG1 monoclonal antibody against programmed cell death ligand-1 (PD L1). This study evaluates the combination of intraperitoneally administered ONCOS-102 with systemic durva in patients with peritoneal disease who have histologically confirmed OC or metastatic CRC and have failed prior standard therapies.This ongoing phase 1/2, open-label study (NCT02963831) evaluates the safety and antitumor/biologic activity of durva (1500 mg intravenous, every 4 weeks x 12) + ONCOS-102 (intraperitoneal, weekly x 6); cyclophosphamide is given before the first ONCOS-102 dose. Phase 1 will follow a 3+3 design to evaluate the ONCOS 102 dose to be given with durva. Phase 2 will evaluate the activity of the combination using Simon’s 2-stage MINIMAX design. In Stage 1, the OC and CRC cohorts will enroll 18 and 13 patients, respectively. If ≥ 5 patients in the OC cohort or ≥ 1 patient in the CRC cohort are progression free at the end of Week 24 (PFS24W), then Stage 2 will enroll 15 and 14 additional patients in the OC and CRC cohorts for a total n of 33 and 27, respectively. The null/alternative hypotheses for PFS24W are 20/40% for OC and 5/20% for CRC. The null hypothesis will be rejected if ≥ 11 patients in the OC cohort or ≥ 4 patients in the CRC cohort experience PFS24W. The primary endpoints are safety/tolerability per Common Terminology Criteria for Adverse Events (CTCAE) for phase 1 and PFS24W rate by RECIST 1.1 for phase 2. Secondary endpoints are safety and tolerability, response rate at 8 and 24 weeks, progression-free survival, and overall survival. Exploratory endpoints are immunologic effects in tumors and peripheral blood. Enrollment opened 07 September 2017. As of 27 June 2018, 4 patients are enrolled; enrollment is ongoing.

Citation Format: Dmitriy Zamarin, Kunle Odunsi, Brian Slomovitz, Vanessa M. Hubbard-Lucey, Danielle McCabe, Lisa Shohara, Paul Schwarzenberger, Toni Ricciardi, Mary Macri, Aileen Ryan, Anne-Kirsti Aksnes, Lukasz Kuryk, Ralph Venhaus. Phase 1/2 study to evaluate systemic durvalumab (durva) + intraperitoneal ONCOS-102 in patients with peritoneal disease who have epithelial ovarian (OC) or metastatic colorectal cancer (CRC) [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A022.

A phase I/II trial of TG01/GM-CSF and gemcitabine as adjuvant therapy for treating patients with resected RAS-mutant adenocarcinoma of the pancreas

4119

Background: TG01 (a mixture of 7 RAS peptides) is an injectable antigen-specific cancer immunotherapy targeted to treat patients (Pts) with KRAS mutations, found in more than 85% of pancreatic adenocarcinomas. There is scope for improvement in adjuvant treatment of resected pancreatic cancer; with 1- and 2-year published overall survival (OS) rates ranging from 56-80% and 30-54% respectively. TG01 induces RAS mutant-specific T-cell responses which are enhanced by co-administration of GM-CSF. This study evaluates safety, immunological response and OS of TG01-immunotherapy with adjuvant gemcitabine chemotherapy. Methods: Pts were eligible after an R0 or R1 pancreatic adenocarcinoma resection. As soon as possible after surgery, TG01 (0.7 mg intradermal injection (id)) together with GM-CSF (0.03 mg id) was given on days 1, 3, 5, 8, 15, 22 and 2-weekly thereafter until the end of gemcitabine (starting within 12 weeks of surgery and given for 6 cycles). Thereafter TG01/GM-CFS were given 4-weekly up to 1 yr and 12-weekly up to 2 yrs. Immune response was assessed using antigen-specific (TG01) Delayed-Type Hypersensitivity (DTH) and T-cell proliferation. OS was assessed from surgery; ~8 weeks before first TG01 injection. Results: To date, 19 pts (68% R1) from 3 sites (Norway and UK) and have been followed for 2 yrs.Eight SARs in 5 pts have occurred; 4 related to gemcitabine (anemia, pulmonary infection and 2 fever); 3 related to TG01/GM-CSF (2 anaphylaxes and 1 hypersensitivity); and 1 possibly related to all products (dyspnea). The allergic reactions only occurred after several cycles of gemcitabine and resolved within 1-2 hrs. There was no treatment related deaths.16/19 (84%) pts had a positive DTH by week 11. Proliferation of mutant RAS specific T-cells is being analyzed. OS rate at 1 and 2 yrs were 89.5% (95% CI 75.7, 100.0) and 68.4 (95% CI 47.5, 89.3), respectively. Median OS was 33.1 months (95% CI 16.8, 40.1). Conclusions: TG01/GM-CSF generated early immune responses in 84% of patients with R0/R1 resected pancreatic cancer. The regimen was generally well tolerated although some late, manageable allergic reactions were seen. OS was encouraging in view of published reports. Clinical trial information: NCT02261714.

Effects of radium-223 dichloride (Ra-223) with docetaxel (D) versus D on prostate-specific antigen (PSA) and bone alkaline phosphatase (bALP) in patients (pts) with castration-resistant prostate cancer (CRPC) and bone metastases (mets): A phase 1/2a clinical trial

202

Background: Ra-223 is an approved α-emitter prolonging survival in CRPC with symptomatic bone mets. We conducted a phase 1/2a study examining the safety and antitumor effects of Ra-223 + D vs D alone, and previously presented data showing that Ra-223 + D is safe and well tolerated (ESMO 2014). Here we report the effect of Ra-223 + D vs D on bALP and PSA dynamics. Methods: D-eligible pts with progressing CRPC and ≥ 2 bone mets were randomized 2:1 to Ra-223 (50 kBq/kg q 6 wk × 5) + D (60 mg/m2 q 3 wk × 10) vs D (75 mg/m2 q 3 wk with step-down option to 60 mg/m2). bALP and PSA were recorded q 3 wk during first 6-wk cycle, then q 6 wk and q 3 wk, respectively, and analyzed at a central laboratory. Changes in both markers are described by the % of pts who achieved ≥ 30%, > 50%, and > 80% declines between baseline and the safety follow-up visit (3 wk post last D injection) as their best response; pts with elevated baseline bALP (≥ 21 µg/L) levels were included for the bALP analysis. bALP to below the upper limit of normal (ULN) was also recorded, regardless of % decline. Results: 46 pts (33 Ra-223 + D vs 13 D alone) were enrolled. As of October 2014, 21 (Ra-223 + D) vs 5 (D) pts had received all planned study treatment. Median (range) baseline PSA was 99 µg/L (3-1000) for Ra-223 + D pts and 43 µg/L (4-1042) for D pts. Maximal changes in PSA and bALP levels between baseline and safety follow-up are shown in Table. No pt had a bALP increase. Conclusions: Ra-223 + D appears to favorably impact posttreatment PSA and bALP declines. Ra-223 + D appears particularly effective at normalizing bALP levels vs D alone. The clinical benefits of such changes in serum markers will require validation in larger prospective studies. Clinical trial information: NCT01106352. [Table: see text]

Radiation safety considerations for the use of ²²³RaCl₂ DE in men with castration-resistant prostate cancer

The majority of patients with late stage castration-resistant prostate cancer (CRPC) develop bone metastases that often result in significant bone pain. Therapeutic palliation strategies can delay or prevent skeletal complications and may prolong survival. An alpha-particle based therapy, radium-223 dichloride (²²³RaCl₂), has been developed that delivers highly localized effects in target areas and likely reduces toxicity to adjacent healthy tissue, particularly bone marrow. Radiation safety aspects were evaluated for a single comprehensive cancer center clinical phase 1, open-label, single ascending-dose study for three cohorts at 50, 100, or 200 kBq kg⁻¹ body weight. Ten patients received administrations, and six patients completed the study with 1 y follow-up. Dose rates from patients administered ²²³Ra dichloride were typically less than 2 μSv h⁻¹ MBq⁻¹ on contact and averaged 0.02 μSv h⁻¹ MBq⁻¹ at 1 m immediately following administration. Removal was primarily by fecal excretion, and whole body effective half-lives were highly dependent upon fecal compartment transfer, ranging from 2.5-11.4 d. Radium-223 is safe and straightforward to administer using conventional nuclear medicine equipment. For this clinical study, few radiation protection limitations were recommended post-therapy based on facility evaluations. Specific precautions are dependent on local regulatory authority guidance. Subsequent studies have demonstrated significantly improved overall survival and very low toxicity, suggesting that ²²³Ra may provide a new standard of care for patients with CRPC and bone metastases.

Pain analyses from the phase III randomized ALSYMPCA study with radium-223 dichloride (Ra-223) in castration-resistant prostate cancer (CRPC) patients with bone metastases

5038

Background: Bone metastases (mets), present in > 90% of patients (pts) with CRPC, may cause severe pain. In a phase 2 dose-response study with a single injection of Ra-223, pain response was seen in up to 71% of CRPC pts with painful bone mets (Nilsson 2012). In the phase 3 ALSYMPCA study, which included 921 CRPC pts with bone mets randomized 2:1 to receive 6 injections of Ra-223 (50 kBq/kg IV) q4wk or matching placebo (Ra-223, n = 614; placebo, n = 307), Ra-223 significantly improved overall survival vs placebo (median 14.9 vs 11.3 mo; HR = 0.695) and was well tolerated. Post hoc analyses of pain parameters in ALSYMPCA are presented. Methods: The Cox proportional hazards model was used to analyze time to initial opioid use and time to EBRT. Pts with no opioid use at baseline were included in the pain analyses. All pts were included in the analysis for the prespecified endpoint time to EBRT. Concomitant opioid use was recorded from first study drug injection to 12 weeks after last injection. Pain-related QOL was analyzed based on the sum of 4 questions within FACT-P prostate cancer subscale (PCS) (Cella 2009) using ANCOVA. Results: Baseline pain characteristics were similar between the treatment groups (approximately 55% of pts had moderate to severe pain and opioid use based on WHO ladder for cancer pain). Time to EBRT was significantly longer with Ra-223 vs placebo (HR = 0.670; 95% CI, 0.525-0.854). Despite a longer observation time, fewer Ra-223 pts (50%) than placebo pts (62%) reported bone pain as an AE. At baseline, 269 Ra-223 pts and 139 placebo pts did not use opioids. Median time to initial opioid use was significantly longer in the Ra-223 group, with a risk reduction of 38%, compared to placebo (HR = 0.621; 95% CI, 0.456-0.846). Fewer Ra-223 pts (36%) than placebo pts (50%) required opioids for pain relief. The QOL pain score indicated reduced pain for Ra-223 pts relative to placebo pts at week 16 (P = 0.001). Ra-223 pts had significant pain reduction relative to baseline at weeks 16 (P < 0.001 ) and 24 (P = 0.001). Conclusions: These results provide consistent evidence that, in addition to prolonging survival, Ra-223 reduces pain and opioid use in CRPC pts with bone mets. Clinical trial information: NCT00699751.

Safety of radium-223 dichloride (Ra-223) with docetaxel (D) in patients with bone metastases from castration-resistant prostate cancer (CRPC): A phase I Prostate Cancer Clinical Trials Consortium Study

5021

Background: Ra-223, a first-in-class α-emitting pharmaceutical, targets bone metastases (mets) with high-energy α-particles of very short range (< 100 µm). D is an approved chemotherapy with demonstrated survival benefit for patients progressing after castrating hormone therapy. We are exploring the hypothesis that simultaneously targeting the tumor and the bone is clinically superior to targeting either alone. We therefore conducted a phase I study of Ra-223 + D in patients with CRPC and bone mets to establish the safety of the combination. Methods: Eligible patients had confirmed symptomatic CRPC with ≥ 2 bone mets and were candidates for treatment with D. Dose escalation followed a 3 + 3 design, with no intrapatient dose escalation or overlapping of cohorts. Patients were to receive 2 combined doses of Ra-223 q6wk + D q3wk (cohort 1: Ra-223/D = 25 kBq/kg /75 mg/m2; cohort 2: Ra-223/D = 25 kBq/kg /60 mg/m2; and cohort 3: Ra-223/D = 50 kBq/kg /60 mg/m2). Dose-limiting toxicity was assessed 6 weeks after first Ra-223 + D injection. Long-term safety data were collected every 3 months after end of study treatment for up to 1 year after start of study treatment. Results: 17 patients were treated, 7 each in cohorts 1 and 3 (1 patient in each cohort discontinued early and was replaced), and 3 in cohort 2. There was no discontinuation or delay of Ra-223 due to adverse events, and so far no reports of long-term toxicity during follow-up. 4 cases of febrile neutropenia occurred during study treatment (12 wk): 3 occurred in cohort 1 (1 was 7 days after first Ra-223 + D, and 2 were in the same subject, both occurring 1 wk after first and second doses of D alone [wk 4 and 10]); 1 occurred in cohort 3, 1 week after second Ra-223 + D (wk 7). Other safety data were as expected based on Ra-223 and D monotherapy data. Conclusions: The phase IIa regimen of Ra-223 + D utilizes a regimen of D 60 mg/m2 q3wk × 10 + Ra-223 50 kBq/kg q6wk × 5. The regimen is currently being explored in a randomized 2:1 open-label expanded safety cohort comparing Ra-223 + D versus D 75 mg/ m2 alone (standard dose). Clinical trial information: NCT01106352.

Pain analysis from the phase III randomized ALSYMPCA study with radium-223 dichloride (Ra-223) in patients with castration-resistant prostate cancer (CRPC) with bone metastases

19

Background: Bone metastases (mets), present in >90% of patients (pts) with CRPC, may cause severe pain. In a phase II dose-response study with Ra-223 treatment, pain response (pain reduction and stable analgesic consumption) was seen in up to 71% of CRPC pts with painful bone mets (Nilsson 2012). In the phase III ALSYMPCA study, which included 921 CRPC pts with bone mets randomized 2:1 to receive 6 injections of Ra-223 (50 kBq/kg IV) q4wk or matching placebo (Ra-223, n=614; placebo, n=307), Ra-223 significantly improved overall survival vs placebo (median 14.9 vs 11.3 mo; HR=0.695) and was well tolerated. Post hoc analyses of pain parameters in ALSYMPCA are presented. Methods: The hazard ratios for time to initial opioid use and time to external beam radiation therapy (EBRT) were analyzed using the Cox proportional hazards model. Pts with no opioid use at baseline were included in the pain analyses. Concomitant opioid use was recorded from first study drug injection to 12 weeks after last injection. Results: Baseline pain characteristics were similar between the treatment groups (approximately 55% of pts had moderate to severe pain and opioid use based on WHO ladder for cancer pain). Time to EBRT was significantly longer in the Ra-223 group vs placebo (HR=0.670, 95% CI: 0.525-0.854). Fewer Ra-223 pts reported bone pain as an AE compared to placebo pts (50% vs 62%). 269 pts in the Ra-223 group and 139 pts in the placebo group had no opioid use at baseline. Median time to initial opioid use was significantly longer in the Ra-223 group, with a risk reduction of 38% compared to placebo (HR=0.621, 95% CI: 0.456-0.846). Fewer pts in the Ra-223 group (36%) than in the placebo group (50%) required opioid use for pain relief. Conclusions: These ALSYMPCA results provide consistent evidence that, in addition to prolonging survival, Ra-223 reduces pain and opioid use in patients with CRPC and bone metastases. Clinical trial information: NCT00699751.

A phase I/IIa study of the safety and efficacy of radium-223 chloride (Ra-223) with docetaxel (D) for castration-resistant prostate cancer (CRPC) patients with bone metastases

TPS4694

Background: Ra-223is a first-in-class alpha-pharmaceutical that targets bone metastases (mets) with high energy alpha-particles of short range (< 100 μm). In the ALSYMPCA trial, Ra-223 plus best standard of care (BSC) significantly improved OS vs placebo plus BSC in CRPC patients (pts) with bone mets (Parker et al. ECCO/ESMO 2011), and was shown to have an excellent safety profile. Since D is an approved chemotherapy with demonstrated survival benefit for pts progressing after castrating hormone therapy, it is logical to explore combining Ra-223 plus D in pts with CRPC and bone mets. This study is being conducted in the Prostate Cancer Clinical Trials Consortium with an aim to establish the safe dose of Ra-223 and D when used in combination in pts with bone mets with CRPC. Methods: This ongoing phase I/IIa trial (NCT01106352) is enrolling pts with bone mets from CRPC intended for treatment with D. D naïve pts are preferred, although up to 10 previous infusions of D are acceptable if D was well tolerated and the patient is in good condition and fulfills all eligibility criteria at study entry. Phase I dose-escalation study: minimum of 9 pts (max. 18 pts) will be included if no dose limiting toxicity (DLT) is observed. Dose escalation will follow a ‘3+3’ design, with no intra-patient dose escalation or overlapping of cohorts permitted. Ra-223 doses are 25 or 50 kBq/kg, with number of Ra-223 injections (inj) (2, 4, 5, or 10) and interval between inj (3 or 6 wks) varying by escalation schema; D doses are 60 or 75 mg/m2 q3wk. DLT will be assessed when 6 wks post-inj safety data are available after 1st Ra-223 +D inj. Phase IIa open-label expanded safety study: pts will be randomized 2:1 to the recommended dose of Ra‑223 to be used with D or to treatment with D alone (approx. 42 pts will be included). Primary endpoint is to assess safety of combining Ra-223 with D. Exploratory efficacy endpoints for the open-label expanded safety portion of the study include change in disease-related biomarkers, time to 1st radiological or clinical progression, CTC and pain assessment. Enrollment in dose-escalation portion of the study is complete; expanded safety cohort to begin enrolling in March 2012.

A bone marrow toxicity model for ²²³Ra alpha-emitter radiopharmaceutical therapy

Ra-223, an α-particle emitting bone-seeking radionuclide, has recently been used in clinical trials for osseous metastases of prostate cancer. We investigated the relationship between absorbed fraction-based red marrow dosimetry and cell level-dosimetry using a model that accounts for the expected localization of this agent relative to marrow cavity architecture. We show that cell level-based dosimetry is essential to understanding potential marrow toxicity. The GEANT4 software package was used to create simple spheres representing marrow cavities. Ra-223 was positioned on the trabecular bone surface or in the endosteal layer and simulated for decay, along with the descendants. The interior of the sphere was divided into cell-size voxels and the energy was collected in each voxel and interpreted as dose cell histograms. The average absorbed dose values and absorbed fractions were also calculated in order to compare those results with previously published values. The absorbed dose was predominantly deposited near the trabecular surface. The dose cell histogram results were used to plot the percentage of cells that received a potentially toxic absorbed dose (2 or 4 Gy) as a function of the average absorbed dose over the marrow cavity. The results show (1) a heterogeneous distribution of cellular absorbed dose, strongly dependent on the position of the cell within the marrow cavity; and (2) that increasing the average marrow cavity absorbed dose, or equivalently, increasing the administered activity resulted in only a small increase in potential marrow toxicity (i.e. the number of cells receiving more than 4 or 2 Gy), for a range of average marrow cavity absorbed doses from 1 to 20 Gy. The results from the trabecular model differ markedly from a standard absorbed fraction method while presenting comparable average dose values. These suggest that increasing the amount of radioactivity may not substantially increase the risk of toxicity, a result unavailable to the absorbed fraction method of dose calculation.

Contrast-enhanced power Doppler imaging of normal and decreased blood flow in canine prostates

The purpose of this study was to investigate if Sonazoid, a new ultrasound (US) contrast agent, can improve the delineation of areas with normal and decreased blood flow in the prostate. Sonazoid was administered in the dose range of 0.00625-0.0375 microL microbubbles/kg into five anaesthetised mongrel adult male dogs. Transrectal power Doppler imaging of the prostate was performed in 2-D and 3-D with a C9-5 end-fire probe, using an HDI 3000 scanner. An area of decreased blood flow was created by inducing tissue ablation with a CL60 laser system, to mimic an avascular lesion. A subjective assessment of the intraprostatic vessels and the prostate vascular architecture was performed, with and without Sonazoid, before and after inducing the abnormal site. Visibility of the prostate blood flow improved following Sonazoid injection (p < 0.001). A symmetric, radial vascular pattern was identified in the normal prostate prior to tissue ablation, but only on the enhanced images. After tissue ablation, a disturbance of the normal vascular pattern and identification of areas with lack of blood flow was possible, following Sonazoid injection. Furthermore, the location and size of these areas were verified in all dogs by gross histology examination. Sonazoid enhances the visibility of the prostate vascular architecture and improves, thereby the delineation of areas with normal and decreased blood flow.

Enhanced visualisation of the normal prostate blood flow in young healthy volunteers using a new ultrasound contrast agent

PURPOSE

To evaluate the sonographic appearance of normal prostate vascularity before and after injection of a new ultrasound contrast agent, Sonazoid (NC100100, Nycomed Amersham).

MATERIAL AND METHODS

Five healthy male volunteers were given three injections of Sonazoid each. Transrectal B-mode, colour Doppler and colour Doppler energy (i.e. power Doppler) imaging was performed. The visibility of the vascular pattern and the vascular architecture of the prostate, including dynamics of contrast inflow and blood flow symmetry, were evaluated.

RESULTS

The depiction of the vascularity was improved in all subjects after injection of Sonazoid for both Doppler modes. No improvement was seen for B-mode. Contrast dynamics within the prostate vessels were demonstrated with a mean time from injection of the ultrasound contrast agent to enhancement of the Doppler signals in the subcapsular arteries of 14+/-1 s (11--17 s), and the ultrasound contrast agent reached the central periurethral veins 4--7 s later. A symmetric, radial, spoke-like intraprostatic vascular pattern could be identified in all subjects using power Doppler imaging and ultrasound contrast agent.

CONCLUSION

Sonazoid improved the detection of normal human prostate vascular anatomy for both colour and power Doppler imaging. Contrast dynamic studies revealed a radial spoke-like intraprostatic vascular pattern. This information might be useful in examination of patients with suspicion of prostate cancer, and needs to be further investigated.

Enhanced detection of blood flow in the normal canine prostate using an ultrasound contrast agent

RATIONALE AND OBJECTIVES

To evaluate the sonographic appearance of normal prostate vascularity in dogs before and after injection of a new ultrasound contrast agent, NC100100.

METHODS

Thirty-five intravenous injections of NC100100, in doses ranging from 0.00625 to 0.05 microL microbubbles/kg, were administered to seven anesthetized mongrel male dogs. Transrectal color Doppler imaging and power Doppler imaging were used to perform the assessment. The visibility of the vascular pattern of the prostate was assessed, including dynamics of contrast inflow, blood flow symmetry, and duration times.

RESULTS

Before contrast administration, the vascular pattern was poorly visualized in all cases. After contrast injection, the visibility of the vascular architecture improved significantly for both modalities. Independent of the imaging method used, higher doses tended to be more effective than lower doses. Contrast kinetics in the prostate vessels was demonstrated with a mean time from injection of the ultrasound contrast agent to enhancement of the Doppler signals in the subcapsular arteries (+/-1 SD) of 13+/-3 seconds, and the ultrasound contrast agent reached the central periurethral veins 3 to 6 seconds later. A spokelike radial pattern of internal prostatic vessels observed with enhanced ultrasound could also be seen on silicone microfil x-ray images. The Doppler enhancement persisted for a mean time ( +/-1 SD) of 904 seconds (approximately 15 minutes) +/- 225 seconds and tended to increase with increasing dose.

CONCLUSIONS

NC100100 significantly improves the detection of blood flow in the normal canine prostate and allows more accurate depiction of the vascular architecture of the prostate.

Exercise-induced overexpression of key regulatory proteins involved in glucose uptake and metabolism in tetraplegic persons: molecular mechanism for improved glucose homeostasis

Complete spinal cord lesion leads to profound metabolic abnormalities and striking changes in muscle morphology. Here we assess the effects of electrically stimulated leg cycling (ESLC) on whole body insulin sensitivity, skeletal muscle glucose metabolism, and muscle fiber morphology in five tetraplegic subjects with complete C5-C7 lesions. Physical training (seven ESLC sessions/wk for 8 wk) increased whole body insulin-stimulated glucose uptake by 33+/-13%, concomitant with a 2.1-fold increase in insulin-stimulated (100 microU/ml) 3-O-methylglucose transport in isolated vastus lateralis muscle. Physical training led to a marked increase in protein expression of GLUT4 (378+/-85%), glycogen synthase (526+/-146%), and hexokinase II (204+/-47%) in vastus lateralis muscle, whereas phosphofructokinase expression (282+/-97%) was not significantly changed. Hexokinase II activity was significantly increased, whereas activity of phosphofructokinase, glycogen synthase, and citrate synthase was not changed after training. Muscle fiber type distribution and fiber area were markedly altered compared to able-bodied subjects before ESLC training, with no change noted in either parameter after ECSL training. In conclusion, muscle contraction improves insulin action on whole body and cellular glucose uptake in cervical cord-injured persons through a major increase in protein expression of key genes involved in the regulation of glucose metabolism. Furthermore, improvements in insulin action on glucose metabolism are independent of changes in muscle fiber type distribution.

Improved body composition after 8 wk of electrically stimulated leg cycling in tetraplegic patients

The practical aspects of utilizing electrically stimulated leg cycling (ESLC) to counteract alterations in body composition were investigated in five tetraplegic subjects with long-standing complete spinal cord injuries (C5-C7). After a 2-wk adaptation period, the subjects performed seven ESLC sessions per week for 8 wk. No adverse reactions were noted in response to the ESLC program. The ESLC sessions were accompanied by higher lactate concentrations compared with arm exercise. Heart rate and blood pressure response revealed clear, but not serious, signs of autonomic dysreflexia in the beginning of the ESLC sessions. Body temperature increased moderately during the ESLC sessions. Peak oxygen uptake (Vo2) during an ESLC session increased by 70% (P < 0.05) after 8 wk of training. Body composition, evaluated by dual-energy X-ray absorptiometry (DEXA), demonstrated an increase in lean body mass (LBM) from 66.2 +/- 2.6 to 68.2 +/- 2.1% (P < 0.05), with a concomitant decrease in whole body fat (BF) content from 29.7 +/- 2.6 to 27.8 +/- 2.1% (P < 0.05) after training. The cross-sectional area of quadriceps, hamstrings, gluteus maximus, and gluteus medius muscles, measured by computer tomographic scans, increased from 267 +/- 27 to 324 +/- 27 cm2 (P < 0.05) after the training. In conclusion, daily ESLC sessions during a 2-mo period resulted in increased LBM, decreased BF content, and increased muscular endurance in tetraplegic subjects without any noticeable adverse effects.

Whole body and splanchnic metabolic and circulatory effects of glucose during beta-adrenergic receptor inhibition

The aim of the study was to assess the possible contribution of adrenergic mechanisms to the thermogenic and circulatory effects of glucose ingestion. With the use of indirect calorimetry and arterial, pulmonary arterial, and hepatic venous catheterization, whole body and splanchnic oxygen uptake and blood flow were examined in nine propranolol-treated healthy male volunteers before and during 2 h after oral ingestion of 75 g of glucose. The glucose effects were compared with those in nine untreated controls. After propranolol, the glucose-induced rise in splanchnic blood flow was reduced by approximately 60%, and the hepatic venous glucose release to the systemic circulation was significantly delayed. Glucose-induced increments in pulmonary and splanchnic oxygen uptake and cardiac output were similar in the two groups. It is concluded that adrenergic mechanisms contribute to the glucose-induced rise in splanchnic blood flow and thereby probably to the time course for intestinal absorption of nutrients. It is suggested that the magnitude of glucose-induced thermogenesis is independent of adrenergic stimulation.

Intact glucose transport in morphologically altered denervated skeletal muscle from quadriplegic patients

The present study was undertaken to investigate the nature of the whole body insulin resistance that characterizes patients with complete cervical spinal cord lesion. Nine patients with C5-C7 lesions and ten age-matched healthy individuals were studied. Whole body insulin-mediated glucose utilization was reduced by 43% in the quadriplegic patients compared with the controls (P < 0.001). In the quadriplegic patients, lean body mass corresponded to 66 +/- 3% of total body mass. Despite whole body insulin resistance, in isolated vastus lateralis muscle, basal and insulin-stimulated 3-O-methylglucose transport, as well as protein expression of the insulin or exercise-regulatable glucose transporter, GLUT-4, and glycogen content were comparable between the patients and controls. Strikingly, muscle fiber area was reduced by 44% (P < 0.05), percentage of type IIb fibers was increased (P < 0.01), and there was a complete loss of type I fibers in the patients. In conclusion, the dissociation between whole body insulin-mediated glucose uptake and skeletal muscle glucose transport in quadriplegic patients primarily reflects the decreased muscle mass. Furthermore, these findings demonstrate a remarkable capacity of skeletal muscle to maintain an intact glucose transport system despite severe morphological alterations.

Metabolic, thermal and circulatory effects of intravenous infusion of amino acids in tetraplegic patients

Metabolic, circulatory and thermal effects of intravenously (i.v.) administered amino acids were studied in eight patients with complete cervical spinal cord injuries, and compared with the effects in eight healthy subjects. Using indirect calorimetry and catheter techniques, whole-body and splanchnic oxygen consumption, blood flow and blood temperatures were measured before and at timed intervals during 2.5 h of i.v. infusion of 600 kJ of a mixture of 19 amino acids. Pulmonary oxygen uptake increased from 209 +/- 11 to 267 +/- 13 ml min-1 in the patients and from 268 +/- 5 to 320 +/- 8 ml min-1 in the controls. The thermic effect of amino acids was 21 +/- 3% and 16 +/- 2% in patients and controls, respectively. In both groups the splanchnic tissues accounted for approximately half of the rise in whole-body oxygen consumption. Cardiac output rose by, on average, 0.5 +/- 0.1 and 0.8 +/- 0.2 1 min-1 in patients and controls, respectively, while the hepatic blood flow remained unchanged in both groups. Pulmonary arterial blood temperature increased by 0.647 +/- 0.100 degrees C in the patients and by 0.244 +/- 0.174 degrees C in the controls (P < 0.05). The whole-body specific heat was low in the patients, its calculated maximum value being approximately 20% below the normal level. During the amino acid infusion the arterial blood concentration of amino acids rose by approximately 170% and 112% of its basal levels in patients and controls, respectively, indicating a significantly reduced capacity for cellular uptake of amino acids in tetraplegic patients. It is concluded that, in tetraplegic patients, i.v. infused amino acids induce prompt thermogenesis of normal magnitude accompanied by supranormal temperatures and amino acid concentrations in the blood, and that low whole-body specific heat contributes to the well-known thermoregulatory instability in tetraplegia.

Glucose-induced thermogenesis in tetraplegic patients with low sympathoadrenal activity

The influence of the sympathoadrenal system on the thermic effect of glucose was examined by studying six tetraplegic patients with complete lesions of the cervical spinal cord. Indirect calorimetry and catheter techniques were employed, and measurements were made before and during 2 h after oral ingestion of 75 g of glucose. The results were compared with previous findings from an identical study in healthy subjects and with those from a control group of five tetraplegic patients receiving water instead of glucose. In response to glucose, energy expenditure rose from 69 +/- 5 to 79 +/- 5 and from 88 +/- 3 to 98 +/- 4 W, (not significant) in the patients and healthy subjects, respectively. In both patients and the healthy subjects the postprandial oxygen consumption increased exclusively in extrasplanchnic tissues. Splanchnic blood flow, which in normals increased 34 +/- 1%, did not change in the patients after glucose. Blood temperatures were unchanged in normals after glucose but rose by approximately 0.5 degrees C in the patients. The patients' arterial plasma concentrations of norepinephrine were low in the basal state and did not rise significantly after glucose. The arterial blood glucose concentrations after glucose were significantly higher in the patients than in the healthy subjects. Insulin levels rose to 105 +/- 20 mU/l in the patients and to 59 +/- 7 mU/l in the controls (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary function and symptom-limited exercise stress testing in subjects with late sequelae of poliomyelitis

Sixty-eight subjects, consecutively admitted to our rehabilitation hospital with a presumptive postpolio syndrome, were examined by pulmonary function and symptom-limited exercise stress testing. The purpose of this investigation was to study how many of these subjects could be classified as suffering from cardiorespiratory deconditioning. The subjects had moderately reduced lung function of restrictive type, and none of the subjects had forced expiratory volume for one second (FEV1) below 30% of predicted value, indicating that hypoventilation would probably not occur. A pronounced reduction in maximal oxygen uptake (max VO2) was seen, especially in women. The maximal heart rate (max HR) values were above 70% of predicted values in all but one subject, indicating that the subjects might benefit from endurance training. Fifteen subjects had a suspected pulmonary limitation due to the exercise, with the ratio ventilation/maximal voluntary ventilation (V/MVV) above 70%. However, max HR in these subjects did not differ from that in the subjects with the ratio V/MVV below 70%. Thirteen other subjects had a ratio V/MVV < 70% but did not achieve respiratory quotient (R) > 1.0 and/or capillary lactate concentration > 4 mmol/l during exercise, indicating that muscular factors limited the exercise. These results indicate that cardiorespiratory deconditioning was considerable in most of our subjects with postpolio syndrome.

Meal-induced rise in resting energy expenditure in patients with complete cervical spinal cord lesions

Central activation of the sympathoadrenal system is generally considered to be an essential component of the mechanisms whereby food ingestion stimulates resting energy expenditure. The functional importance of such sympathoadrenal stimulation has been demonstrated primarily in animals. To the extent that central sympathoadrenal stimulation is required for normal human nutrient-induced thermogenesis, this process should be defective in patients with complete cervical spinal cord lesion and severed connection between the central nervous system and the peripheral sympathetic nerves. Consequently, respiratory gas exchange was measured by indirect calorimetry in 9 tetraplegic patients and in 6 healthy individuals. Measurements were performed before and 2 hours after ingestion of a standardised mixed meal (40% of basal 24 h energy requirements). The basal energy expenditure was 64 +/- 4 watts in the tetraplegic patients and 79 +/- 6 watts in the controls. After the meal, energy expenditure increased on average by 17 +/- 2 watts or 26 +/- 3% of the basal values in the patients and by 14 +/- 2 watts or 19 +/- 3% in the healthy controls (NS). The thermic effect of the meal, ie the rise in energy expenditure expressed in percent of the meal's energy content, was 5.5 +/- 0.7% in the patients and 3.8 +/- 0.6% in the controls (NS). Plasma concentrations of noradrenaline were low in the tetraplegic patients (0.3-0.4 nmol/l) compared to the healthy controls (1.1-1.4 nmol/l), p < 0.02. It is concluded that nutrient-induced thermogenesis in tetraplegic patients with low sympathoadrenal activity is not diminished compared to healthy controls. The findings indicate that efferent sympathoadrenal stimulation from the brain is not a causal necessity for nutrient-induced thermogenesis in man.

Lung volumes in tetraplegic patients according to cervical spinal cord injury level

Fifty-six tetraplegic patients with motor complete lesions (Frankel A and B) underwent spirometric measurements more than 6 months after injury. The results were evaluated according to the level of transection of the cervical cord. A pronounced restrictive respiratory dysfunction was demonstrated in all patients. The expiratory reserve volume (ERV) was zero or markedly reduced in patients at all lesion levels. Systematic increases in both ERV and vital capacity (VC) were found with lower lesion level. The inspiratory capacity (IC) was reduced at all injury levels, but there were no systematic differences in IC between injury levels C4-C8. The total lung capacity (TLC) was reduced and the ratio residual volume/total lung capacity (RV/TLC) was increased in patients at all injury levels. The lung function of patients tested > 12 months after injury was not significantly different from the function in those tested 6-12 months after injury. A respiratory rehabilitation programme for tetraplegic patients should take into account the fact that the respiratory function, especially the forced expiration, is dependent upon injury level.