Utility of cell-based vaccines as cancer therapy: Systematic review and meta-analysis

Cell-based therapeutic cancer vaccines use autologous patient-derived tumor cells, allogeneic cancer cell lines or autologous antigen presenting cells to mimic the natural immune process and stimulate an adaptive immune response against tumor antigens. The primary objective of this study is to perform a systematic literature review with an embedded meta-analysis of all published Phase 2 and 3 clinical trials of cell-based cancer vaccines in human subjects. The secondary objective of this study is to review trials demonstrating biological activity of cell-based cancer vaccines that could uncover additional hypotheses, which could be used in the design of future studies. We performed the systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The final review included 36 studies - 16 single-arm studies, and 20 controlled trials. Our systematic review of the existing literature revealed largely negative trials and our meta-analysis did not show evidence of clinical benefit from cell-based cancer-vaccines. However, as we looked beyond the stringent inclusion criteria of our systematic review, we identified significant examples of biological activity of cell-based cancer vaccines that are worth highlighting. In conclusion, the existing literature on cell-based cancer vaccines is highly variable in terms of cancer type, vaccine therapies and the clinical setting with no overall statistically significant clinical benefit, but there are individual successes that represent the promise of this approach. As cell-based vaccine technology continues to evolve, future studies can perhaps fulfill the potential that this exciting field of anti-cancer therapy holds.

Abstract P4-07-23: Results of a Phase 2 Trial of Combination Immunotherapy with Concurrent Nelipepimut-S + GM-CSF and Trastuzumab in High-risk HER2+ Breast Cancer Patients

INTRODUCTION: The HER2-targeted peptide vaccine nelipepimut-S + GM-CSF (NeuVax) has been shown to be safe, immunogenic, and potentially synergistic with trastuzumab. Here we present the results of a randomized phase 2 trial assessing the ability of nelipepimut-S/GM-CSF versus GM-CSF alone, added to the standard adjuvant Trastuzumab, to prevent recurrences in high-risk HER2-positive breast cancer patients. METHODS: The study was a multi-center, prospective, randomized, controlled, single-blinded, phase 2 trial. Enrolled patients had high risk HER2+ breast cancer defined by the presence of residual disease post neoadjuvant therapy or by the presence of positive lymph nodes after upfront surgery. Eligible patients had completed an approved trastuzumab-chemotherapy containing regimen and they were receiving adjuvant Trastuzumab monotherapy. Enrollment was limited to patients with HLA-A2, A3, A24, and/or A26 alleles. Patients received intradermal injections of nelipepimut-S + GM-CSF or placebo + GM-CSF every three weeks for six total vaccinations with concurrent, standard monotherapy with iv trastuzumab. After completion of the primary vaccine series, booster inoculations were administered every six months for four doses. The primary outcome measure was invasive disease-free survival (iDFS) at 36 months. Secondary outcome measures were distant recurrence-free survival (DRFS), toxicity assessment, and evaluation of immune response. RESULTS: 100 patients were enrolled and randomized 1:1 to nelipepimut-S/GM-CSF or GM-CSF alone. There were no significant clinicopathologic differences between the groups. There was no difference in related local (p=0.49) or systemic toxicities (p=0.41). Kaplan-Meier estimates of iDFS at 36 months were 79% in the nelipepimut-S arm and 92% in the placebo arm (log rank, p=0.11). DRFS at 36 months was estimated to be 90% in the nelipepimut-S arm and 95% in the placebo arm (log rank, p=0.40). Delayed type hypersensitivity (DTH) response to nelipepimut-S was measured and considered positive if there was more than 5 mm induration after 48 hours. DTH response converted from negative to positive in 11% of patients in the vaccine group versus 5% of patients in the placebo group (p=0.36). In both groups, iDFS at 36 months was 100% for those with a positive DTH response post-inoculation and 88% for those with a negative DTH response post-inoculation (log rank, p=0.29). CONCLUSION: Combination immunotherapy with concurrent nelipepimut-S + GM-CSF and trastuzumab is safe, however there was no difference in iDFS or DRFS among high-risk HER2+ breast cancer patients who received nelipepimut-S + GM-CSF compared to GM-CSF alone. We observed a trend towards improved iDFS in patients with a positive DTH response to nelipepimut-S, though it was not statistically significant.

Citation Format: Ankur Tiwari, Guy Clifton, Carmen Calfa, Gheath Alatrash, Jarrod Holmes, Isabelle Bedrosian, George Peoples, Elizabeth A. Mittendorf. Results of a Phase 2 Trial of Combination Immunotherapy with Concurrent Nelipepimut-S + GM-CSF and Trastuzumab in High-risk HER2+ Breast Cancer Patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-23.

542 Randomized trial of tumor lysate particle only vaccine vs. tumor lysate particle-loaded, dendritic cell vaccine to prevent recurrence of resected stage III/IV melanoma: 36-month analysis

Background

The tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is an autologous tumor vaccine that decreased recurrence in stage III/IV melanoma when granulocyte-colony stimulating factor (G-CSF) was not used to harvest the dendritic cells in a randomized phase 2B adjuvant trial.1The tumor lysate (TL) particle only (TLPO) vaccine utilizes a similar mechanism, but with autologous TL-loaded yeast cell wall particles; this eliminates the need for dendritic cell (DC) collection and ex-vivo loading and reduces production costs and time. The TLPO vaccine was compared to TLPLDC in an embedded bridging portion of the trial. Here, we examine 36-month outcomes of the ongoing randomized, double-blind phase 2 trial in patients (pts) with resected stage III/IV melanoma.

Methods

Pts were randomized 2:1 to receive TLPO or TLPLDC as a continuation of a previously established clinical trial comparing TLPLDC versus placebo. The TLPLDC group was analyzed separately based on use (or not) of G-CSF for collection of DC. Safety was measured by the Common Terminology Criteria for Adverse Events (CTCAE). Kaplan-Meier and log-rank analysis was used to compare 36-month disease-free survival (DFS) and overall survival (OS) in the intention-to-treat (ITT) main arms as well as pre-specified subgroups.

Results

A total of 187 pts were randomized with 41, 47, 56, and 43 pts enrolled in the placebo, TLPLDC without G-CSF (TLPLDC), TLPLDC with G-CSF (TLPLDC+G), and TLPO arm, respectively. Pts randomized to the TLPO arm were more likely to have stage IV melanoma (22.0% for placebo, 20.4% for TLPLDC and TLPLDC+G, and 44.2% for TLPO; p = 0.002) and to receive prior immunotherapy (36.6% for placebo, 39.8% for both TLPLDC and TLPLDC+G, and 83.7% for TLPO; p < 0.001). Grade 3+ adverse events were not significantly different between arms. In the ITT analysis, 36-month DFS was 30.0% for placebo, 55.8% for TLPLDC, 24.4% for TLPLDC+G, and 64.0% for TLPO (p < 0.001). OS at 36 months was 70.9% for placebo, 94.2% for TLPLDC, 69.8%% for TLPLDC+G, and 94.8% for TLPO (p = 0.011) (figure 1).

Abstract 542 Figure 1

Kaplan-Meier curves demonstrating DFS (A) and OS (B) between Placebo (n=41), TLPLDC (n=47), TLPLDC+G (n=56), and TLPO (n=43)

Conclusions

The TLPO and TLPLDC (without G-CSF) vaccines improved 36-month DFS and OS in this randomized phase 2 trial. The efficacy of the TLPO and TLPLDC vaccines will be confirmed in a phase III trial in resected Stage III/IV melanoma pts.

Trial Registration

NIH, clinicaltrials.gov, NCT02301611

References

O’Shea AE, Chick RC, Clifton GT, et al. The effect of pretreatment with G-CSF prior to dendritic cell collection during the phase IIb trial of an autologous DC-based vaccine for advanced, resectable melanoma. Presented at: Society for Immunotherapy of Cancer 35th Anniversary Annual Meeting & Preconference Programs (SITC 2020); November 11–14, 2020. Abstract 310. J Immunother Cancer. 2020;8(Suppl 3):A656–A959.

Ethics Approval

The clinical trial protocol was approved by the Western Institutional Review Board (2014–1932). All participants provided informed consent prior to enrollment in the trial.

A betacoronavirus multiplex microsphere immunoassay detects early SARS-CoV-2 seroconversion and antibody cross reactions

Sensitive and specific SARS-CoV-2 antibody assays remain critical for community and hospital-based SARS-CoV-2 surveillance. Here, we developed and applied a multiplex microsphere-based immunoassay (MMIA) for COVD-19 antibody studies that incorporates spike protein trimers of SARS-CoV-2, SARS-CoV-1, MERS-CoV, and the seasonal human betacoronaviruses, HCoV-HKU1 and HCoV-OC43, that enables measurement of off-target pre-existing cross-reactive antibodies. The MMIA performances characteristics are: 98% sensitive and 100% specific for human subject samples collected as early as 10 days from symptom onset. The MMIA permitted the simultaneous identification of SARS-CoV-2 seroconversion and the induction of SARS-CoV-2 IgG antibody cross reactions to SARS-CoV-1 and MERS-CoV. Further, synchronous increases of HCoV-OC43 IgG antibody levels was detected with SARS-CoV-2 seroconversion in a subset of subjects for whom early infection sera were available prior to their SARS-CoV-2 seroconversion, suggestive of an HCoV-OC43 memory response triggered by SARS-CoV-2 infection.

431 Prospective, randomized trial of the tumor lysate, particle only vaccine compared to the tumor lysate, particle-loaded, dendritic cell vaccine to prevent recurrence for resected stage III/IV melanoma

Background

The autologous tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is safe and effective in improving 24 and 36-month disease-free survival (DFS) in patients (pts) with resected stage III/IV melanoma who completed the primary vaccine series. The tumor lysate, particle only (TLPO) vaccine has been developed to accelerate production by omitting DC isolation and ex vivo loading in favor of in vivo phagocytosis of the TL-loaded particles. We are currently conducting a randomized and double-blind trial of the TLPO vs TLPLDC to improve DFS and overall survival (OS) in patients with resected late stage melanoma.

Methods

Patients with stage III/IV melanoma who were clinically disease-free after standard of care therapies were randomized to receive TLPO vs TLPLDC (2:1) as a continuation of the phase IIb trial comparing TLPLDC vs placebo (2:1). For the TLPLDC vaccine, autologous TL was loaded into yeast cell wall particles (YCWP) which were then phagocytized by isolated autologous DC ex vivo. For the placebo DC were loaded with empty YCWP. For TLPO, the autologous TL-loaded YCWP were coated with a chemoattractant and injected intradermally for in vivo phagocytosis. Some patients in the TLPLDC arm received G-CSF prior to DC harvest to minimize blood draw (60 mL instead of 120 mL without G-CSF). For all arms, six vaccine/placebo doses were administered intradermally at 0, 1, 2, 6, 12, and 18 mos. Data was analyzed by an intention-to-treat (ITT) analysis for DFS and OS by the Kaplan-Meier method and compared by log-rank test.

Results

63 pts were randomized to TLPO (n=43) vs TLPLDC (n=20). The TLPO cohort contained more females and received less chemotherapy (0% vs 10%), but otherwise were comparable. There were no differences in DFS (p=0.948) or OS (p=0.779) between the two vaccines (figures 1&2). Comparing the TLPO pts to all other pts in the phase IIb trial [TLPLDC+G-CSF (n=57), TLPLDC-G-CSF (n=46), and placebo (n=41)] the TLPO arm had improved DFS compared to placebo (p=0.019) and TLPLDC+G-CSF (p=0.001), but roughly equivalent to the TLPLDC-G-CSF arm (p=0.276) (figure 3). A similar trend was seen in OS analysis, though differences were not statistically significant (figure 4).

Abstract 431 Figure 1

TLPO vs TLPLDC (n=20) DFS. Disease-free survival of TLPO patients compared to similar TLPLDC patients (n=20)

Abstract 431 Figure 2

TLPO vs TLPLDC (n=20) OS. Overall survival of TLPO patients compared to similar TLPLDC patients (n=20)

Abstract 431 Figure 3

TLPO vs TLPLDC subsets vs Placebo DFS. Disease-free survival of TLPO patients compared to placebo and all TLPLDC patients (n=103) stratified by use of G-CSF

Abstract 431 Figure 4

TLPO vs TLPLDC subsets vs Placebo OS. Disease-free survival of TLPO patients compared to placebo and all TLPLDC patients (n=103) stratified by use of G-CSF

Conclusions

TLPO and TLPLDC vaccines (without the use of G-CSF) improve DFS in patients with resected stage III/IV melanoma compared to placebo. The TLPO vaccine may offer advantages via reduced cost and vaccine production time. TLPO should be closely considered for further clinical trials.

Trial Registration

NCT02301611: Phase IIB TL + YWCP + DC in MelanomaTLPLDC IND#16101TLPO IND#17274

Ethics Approval

This study was approved by WIRB; protocol #20141932

Cancer vaccines in colon and rectal cancer over the last decade: lessons learned and future directions

INTRODUCTION

Great advances have been made in screening for and treatment of colorectal cancer (CRC), but recurrence rates remain high and additional therapies are needed. There is great excitement around the field of immunotherapy and many attempts have been made to bring immunotherapy to CRC through a cancer vaccine. Areas covered: This is a detailed review of the last decade's significant CRC vaccine trials. Expert commentary: Monotherapy with a CRC vaccine is likely best suited for adjuvant therapy in disease free patients. Vaccine therapy elicits crucial tumor infiltrating lymphocytes, which are lacking in microsatellite-stable tumors, and therefore may be better suited for these patients. The combination of CRC vaccines with checkpoint inhibitors may unlock the potential of immunotherapy for a much broader range of patients. Future studies should focus on vaccine monotherapy in correctly selected patients and combination therapy in more advanced disease.

Effect of an enhanced medical home on serious illness and cost of care among high-risk children with chronic illness: a randomized clinical trial

IMPORTANCE

Patient-centered medical homes have not been shown to reduce adverse outcomes or costs in adults or children with chronic illness.

OBJECTIVE

To assess whether an enhanced medical home providing comprehensive care prevents serious illness (death, intensive care unit [ICU] admission, or hospital stay >7 days) and/or reduces costs among children with chronic illness.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of high-risk children with chronic illness (≥3 emergency department visits, ≥2 hospitalizations, or ≥1 pediatric ICU admissions during previous year, and >50% estimated risk for hospitalization) treated at a high-risk clinic at the University of Texas, Houston, and randomized to comprehensive care (n = 105) or usual care (n = 96). Enrollment was between March 2011 and February 2013 (when predefined stopping rules for benefit were met) and outcome evaluations continued through August 31, 2013.

INTERVENTIONS

Comprehensive care included treatment from primary care clinicians and specialists in the same clinic with multiple features to promote prompt effective care. Usual care was provided locally in private offices or faculty-supervised clinics without modification.

MAIN OUTCOMES AND MEASURES

Primary outcome: children with a serious illness (death, ICU admission, or hospital stay >7 days), costs (health system perspective). Secondary outcomes: individual serious illnesses, medical services, Medicaid payments, and medical school revenues and costs.

RESULTS

In an intent-to-treat analysis, comprehensive care decreased both the rate of children with a serious illness (10 per 100 child-years vs 22 for usual care; rate ratio [RR], 0.45 [95% CI, 0.28-0.73]), and total hospital and clinic costs ($16,523 vs $26,781 per child-year, respectively; cost ratio, 0.58 [95% CI, 0.38-0.88]). In analyses of net monetary benefit, the probability that comprehensive care was cost neutral or cost saving was 97%. Comprehensive care reduced (per 100 child-years) serious illnesses (16 vs 44 for usual care; RR, 0.33 [95% CI, 0.17-0.66]), emergency department visits (90 vs 190; RR, 0.48 [95% CI, 0.34-0.67]), hospitalizations (69 vs 131; RR, 0.51 [95% CI, 0.33-0.77]), pediatric ICU admissions (9 vs 26; RR, 0.35 [95% CI, 0.18-0.70]), and number of days in a hospital (276 vs 635; RR, 0.36 [95% CI, 0.19-0.67]). Medicaid payments were reduced by $6243 (95% CI, $1302-$11,678) per child-year. Medical school losses (costs minus revenues) increased by $6018 (95% CI, $5506-$6629) per child-year.

CONCLUSIONS AND RELEVANCE

Among high-risk children with chronic illness, an enhanced medical home that provided comprehensive care to promote prompt effective care vs usual care reduced serious illnesses and costs. These findings from a single site of selected patients with a limited number of clinicians require study in larger, broader populations before conclusions about generalizability to other settings can be reached.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02128776.

Interim Analysis of a Randomized Phase II Study of the Novel Ii-Key Hybrid HER2/Neu Peptide (AE37) Vaccine To Prevent Breast Cancer Recurrence: United States Military Cancer Institute Clinical Trials Group Study I-05

BACKGROUND: CD4+ T helper peptides from HER2/neu have been evaluated in vaccine trials. The Ii-Key addition, a 4-amino-acid (LRMK) modification, increases vaccine potency when compared to unmodified class II epitopes. We present results of a prospective, randomized, single-blinded phase II clinical trial of the Ii-Key hybrid HER2/neu peptide (AE37) + GM-CSF immunoadjuvant vaccine versus GM-CSF alone in the adjuvant setting in disease-free, high risk breast cancer (BCa) patients to prevent recurrence.METHODS: Disease-free, high risk BCa patients who have completed standard adjuvant therapy were enrolled and randomized to receive six monthly inoculations of either 500 mcg of AE37 with 62.5 or 125 mcg of GM-CSF (Peptide group; PG) or 62.5 or 125 mcg of GM-CSF alone (adjuvant group; AG). Toxicity was assessed after each inoculation using National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 (CTCAE). Immunologic response was monitored using delayed type hypersensitivity reactions (DTH) and 3H-thymidine proliferative assays for both hybrid AE37 (LRMK+HER2/neu:776-790) and AE36 (unmodified HER2/neu:776-790) peptides. Patients were clinically, radiographically, and pathologically monitored for recurrence of BCa.RESULTS: Thus far, 120 (49 PG, 71 AG) of the planned 200 patients have completed the primary series. The PG and AG have similar demographic/prognostic characteristics (Table 1). Toxicity profiles in the PG and AG were almost identical with no grade 4-5 local toxicities and no grade 3-5 systemic toxicities in either arm. Median DTH reaction to AE36 and AE37 increased significantly from baseline at 1 month after completion of the primary series in the PG group (AE36: 0.0±0.8 cm to 15.3 ±2.1 cm; AE37: 0.0±0.7 cm to 24.5±2.6 cm; p&lt;0.0001) and did not change in the AG group (AE36: 0.0±0.5 cm to 0.0±1.4 cm; AE37: 0.0±0.7 cm to 0.0±1.6 cm; p&gt;0.05). Median proliferation response to AE36 and AE37 increased significantly from baseline at 3, 6, and 12 months after the start of the vaccine series in the PG (p&lt;0.015) and did not change significantly in the AG. At a median follow up of 13 months, there have been no (0.0%) recurrences in the PG (0/49) compared to 7.0% (5/71) in the AG (p=0.08).CONCLUSIONS: The modified peptide AE37 is safe with mild toxicities observed primarily due to the GM-CSF immunoadjuvant. AE37 elicits a strong HER2/neu-specific in-vivo and ex-vivo immune response to the modified and unmodified peptides. Importantly, the AE37 peptide vaccine may protect against BCa recurrences. peptideadjuvantp valueN=4971 Age (median)49520.06Node Positive75.5%62.1%0,16Grade 348.9%57.8%0.44Tumor ≥2 cm55.1%56.1%1ER/PR negative38.8%40.9%0.84HER2 over-expressor59.2%60.6%1 

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3183.

NOTE: This abstract was accepted for presentation at the Symposium after the Abstract Book went to press.

Cationic lipid-mediated NGF gene transfection increases neurofilament phosphorylation

We examined the effect of cationic lipid-mediated gene transfection of nerve growth factor (NGF) in primary septo-hippocampal cell cultures. Rat NGF cDNA was subcloned into a pUC19-based plasmid containing a CMV promoter. Two days after NGF gene transfection in primary cell cultures, ELISA confirmed increases in NGF protein secretion from transfected cells. To study the biological effect of cationic lipid-mediated NGF gene transfection, we analyzed the amount of neurofilament protein from NGF-transfected cell cultures. Western blot and immunohistochemical analyses detected significant increases in the phosphorylated form of neurofilament proteins in the cultures after cationic lipid-mediated NGF cDNA transfection. Cationic lipid-mediated NGF cDNA transfection did rot cause significant changes in the total amount of neurofilament protein. Our studies suggest that cationic lipid-mediated NGF gene transfection can increase neurofilament phosphorylation but not total neurofilament protein.

Sustained expression of functional nerve growth factor in primary septo-hippocampal cell cultures by liposome-mediated gene transfer

We examined liposome-mediated gene transfection of nerve growth factor (NGF) in primary central nervous system cultures. RT-PCR analyses detected increased expression of NGF mRNA one day after liposome-mediated NGF gene transfection. ELISA studies detected large increases in NGF protein in cells and in culture medium after NGF gene transfection. Cells continued to secrete NGF into the medium for at least 2 weeks. NGF bioassays confirmed that the NGF secreted after gene transfection was biologically active.

Optimizing liposome-mediated gene transfer in primary rat septo-hippocampal cell cultures

Although liposomes have been widely employed to transfect DNA into a variety of cell types, no previous studies have systematically examined conditions producing optimal liposomal-mediated transfection of DNA into central nervous system (CNS) cells. Thus, we used the beta-galactosidase (beta-gal) reporter gene to examine factors influencing the efficiency of liposome-mediated gene transfection in CNS cell cultures. Our results indicate that without increasing the amounts of DNA, increased liposome concentrations within certain limits enhanced transfection efficiency. However, higher liposome levels could produce cell lysis. Without increasing liposome concentrations, increased amounts of DNA did not improve transfection efficiency. Employing the optimal concentration (1 microgram DNA/3 microliters liposomes/well), beta-gal gene expression was sustained for at least two weeks after transfection in primary septo-hippocampal cultures.

Resuscitation from prolonged cardiac arrest with high-dose intravenous magnesium sulfate

We present evidence of resuscitation from prolonged (70-min) cardiac arrest, temporally associated with administration of 8 g intravenous (IV) magnesium sulfate (MgSO4). A patient undergoing liposuction surgery developed bradycardia and a fall in oxygen tension after reversal of general anesthesia with physostigmine. The electrocardiogram (ECG) rhythm degenerated to ventricular asystole, which was refractory to standard therapy, including multiple boluses of epinephrine, atropine, wide-open dopamine, and attempts at right heart pacing. External cardiopulmonary resuscitation (CPR) was continuously maintained with the patient intubated on 100% oxygen. Multiple electric countershocks (x7) and lidocaine were also administered when ventricular tachycardia/ventricular fibrillation (VT/VF) occurred, but without clinical success. Approximately one hour into the resuscitation, after all of the above occurred, 8 g IV MgSO4 was given and countershock repeated. Whereas the 7 previous countershocks had resulted in unsuccessful conversion of VT/VF to a pulseless rhythm (EMD), the 8th countershock (applied immediately after two 4 g boluses of IV MgSO4) resulted in a stable pulse and normal sinus rhythm developing within 4 minutes. The patient recovered without neurologic deficit.

The effects of enoximone on renal function in patients with congestive heart failure

Enoximone is an investigational cardiotonic agent with positive inotropic and vasodilatory properties. In this protocol the effects of enoximone on parameters of renal function in patients (n = 14) with New York Heart Association class II or III congestive heart failure were determined after intravenous (IV) treatment (2 mg/kg) and after chronic oral administration (150 mg t.i.d.), either alone or with added furosemide (40 mg b.i.d.). Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), filtration fraction, mean arterial pressure (MAP), renal blood flow (RBF), and renal vascular resistance (RVR) were determined each time. Plasma volume (PV) was determined at baseline and after oral enoximone and after oral enoximone plus furosemide. Significant reductions in GFR (18%) and ERPF (20%) were observed after IV treatment but not after oral treatment with or without furosemide. MAP also was lowered significantly by 14% after IV administration but not after oral treatments. PV after oral enoximone plus furosemide was reduced significantly (31%) compared with baseline. These results demonstrate that enoximone produces acute reductions in GFR and ERPF when given intravenously but has no effect on parameters of renal function when given orally, either alone or with furosemide.

CSF brain creatine kinase levels and lactic acidosis in severe head injury

The posttraumatic creatine kinase-BB isoenzyme (CKBB) activity and lactate concentration in ventricular cerebrospinal fluid (CSF) have been studied in 29 patients with severe head injuries. The CKBB activity reaches its maximum a few hours after trauma, and has a monoexponential drop with a half-time of approximately 10 hours. Ventricular CSF lactate concentration continues to rise in patients with a poor outcome, and decreases only slowly and inconsistently in most of the other patients. Thus, increase of lactate in the ventricular CSF is not, like CKBB, a direct one-stage consequence of the trauma but is due to continuous production from a derangement of metabolism caused by the trauma. Since even higher ventricular CSF lactate levels can be survived when not caused by head injury, and since no significant pH changes were related to the ventricular CSF lactic acidosis in these artificially ventilated patients, it is concluded that ventricular CSF lactic acidosis is indicative of a severe, although not necessarily intractable, disturbance of brain function associated with intracellular lactate production and acidosis.

Developing a system of comprehensive care for the spinal cord injured patient in Houston, Texas, U.S.A

The authors agree with the principle, widely accepted, that spinal cord injured (SCI) individuals should receive all their acute, rehabilitative and follow-up care in a spinal cord injury centre. The evolution of rehabilitation medicine and services in the United States, however, has favoured the separation of acute and rehabilitation care for spinal cord injured patients, as well as other disabilities. This has resulted partly from specialisation of medical and allied health personnel, physical separation of acute and rehabilitation facilities, and reluctance of some funders of health care to see rehabilitation as a natural extension of medical care in these patients. In Houston the proximity of a rehabilitation facility to three acute care university hospitals, representing three medical schools, provided an opportunity to improve communication among the medical personnel. These individuals have recognised the value of early rehabilitation even while the patient is acutely ill; they agreed to institute a system of care wherein the rehabilitation physician partakes in the early management in a designated area of the acute hospitals for spinal cord injured patients and works toward early transfer to the rehabilitation hospital in as ideal a condition as possible. Surgeons, who have initial primary responsibility, also visit the rehabilitation hospital, following their patient's progress at selected conferences and at the bedside. This paper describes how, a spinal cord injury service was established, how the major barriers to early transfer were confronted, and the results of the first 6 months of operation.

Effects of labetalol and methyldopa on renal function

Renal function studies were performed in subjects with mild hypertension treated with labetalol (n = 5) and moderate to moderately severe hypertension treated in a random double-blind fashion with either labetalol (n = 6) or methyldopa (n = 6). Drugs were given in doses sufficient to reduce standing diastolic blood pressure to less than 90 mm Hg. This was achieved in all subjects without significant side effects. Inulin clearance, para-aminohippurate clearance, filtration fraction, free-water clearance, and maximal concentrating ability was assessed before and after 15 days of drug. No alterations in any parameter were noted with labetalol. Inulin clearance fell by 13% (p less than 0.05), and filtration fraction fell from 0.23 to 0.18 (p less than 0.02), but other parameters of renal function did not change with methyldopa.

The glutathione S-transferases of the small intestine in the rat

Glutathione S-transferase activities have been identified in the small intestine of the rat. Thrree activities obtained with p-nitrobenzyl chloride (aralkyl), 1,2-epoxy-3(p-nitrophenoxy)propane (epoxide), and ethacrynic acid (alkene) as substrates were present in significant amounts. Gel filtration indicated an elution volume for the intestinal transferase activities that was similar to those activities in the liver and kidney. The induction of the intestinal transferases by polycyclic aromatic hydrocarbons and phenobarbital is similar to those effects observed previously for the hepatic and renal enzymes. The highest concentration of transferase activities occurs in the proximal small intestine; these activities are reduced upon fasting. Parallel observations have been reported for aryl hydrocarbon hydroxylases. Because only low or negligible levels of epoxide hydrases have been reported in the small intestine, the glutathione S-transferases may be the primary epoxide-detoxifying system in that organ.

Comparison of renal and hepatic glutathione S-transferases in the rat

Renal and hepatic GSH (reduced glutathione) S-transferase were compared with respect to substrate and inhibitory kinetics and hormonal influences in vivo. An example of each of five classes of substrates (aryl, aralkyl, epoxide, alkyl and alkene) was used. In the gel filtration of renal or hepatic cytosol, an identical elution volume was found for all the transferase activities. Close correspondence in Km values was found for aryl, epoxide- and alkyl-transferase activities, with only the aralkyl activity significantly lower in kidney. Probenecid and p-aminohippurate were competitive inhibitors of renal aryl-, aralkyl-, epoxide- and alkyl-transferase activities and inhibited renal alkene activity. Close correspondence in Ki values for inhibition by probenecid of these activities in kidney and liver was found. In addition, furosemide was a potent competitive inhibitor of renal alkyl-transferase activity. Hypophysectomy resulted in significant increases in aryl-, araklyl-, and expoxide-transferase activities in liver and kidney. The hypophysectomy-induced increases in renal aryl- and aralkyl-transferase activities (approx. 100%) were more than twofold greater than increases in hepatic activities (approx. 40%). Administration of thyroxine prevented the hypophysectomy-induced increase in aryltransferase activity in both kidney and liver. The renal GSH S-transferases, in view of similarities to the hepatic activities, may play a role as cytoplasmic organic-anion receptors, as previously proposed for the hepatic enzymes.

Drug induction and sex differences of renal glutathione S-transferases in the rat

Treatment of male rats with 3,4-benzopyrene, 3-methylcholanthrene and phenobarbital resulted in the induction of glutathione S-aryl- and S-aralkyl-transferase activities in kidney cytosol. Benzopyrene produced 77 and 44% increases in aryl and aralkyl activities respectively. Methylcholanthrene caused 73 and 86% increases in the retrospective activities, whereas phenobarbital treatment increased only aralkyl activity (51%). There was no effect on epoxide or alkyl glutathione S-transferase activities with these treatments. Differences were found between the specific activities of the four glutathione S-transferases in females and males, with the following female/male ratios: aryl 0.74; aralkyl 2.37; epoxide 1.52; alkyl 1.33. No changes in Km values were observed relative to drug induction or sex differences. Comparisons are made between the findings of this report and corresponding experiements with liver.

Hepatic glutathione S-transferases: identification by gel filtration and in vitro inhibition by organic anions

In the gel filtration of 100,000 g rat liver supernatant, four major glutathione S-transferase activities, S-aryl-, S-epoxide-, S-aralykyl, and S-alkyltransferase, were identified as having an elution volume identical to that of fractions exhibiting either glutathione or sulfobromophthalein sodium binding. The organic anions, sulfobromophthalein sodium, indocyanine green, and bilirubin, were found to be competitive inhibitors of the four glutathione S-transferase activities. These findings indicate that the glutathione S-transferases bind organic anions, and as a group, have a similar molecular weight to a known organic anion-binding protein. It is proposed that these enzymes also serve nonenzymically as a group of binding proteins in the hepatic cytoplasmic transport of organic anions.

Drug induction of hepatic glutathione S-transferases in male and female rats*

The induction of the glutathione S-transferases by phenobarbital and polycyclic hydrocarbons was studied in male and female rats. Administration of phenobarbital resulted in 60-80% increase in S-aryl and S-aralkyl enzyme specific activities, whereas the S-epoxide and S-alkyl activities were increased by 30-40%. In following the sequence of induction, the former two activities were noted to reach peak activities before an increase in the latter two activities was observed. Both 3-methylcholanthrene and 3,4-benzopyrene were shown toi nduce these four enzymic activities, although without the discrimination between pairs of activities noted with phenobarbital. No change in Km accompanied the increase in Vmax. after induction by drugs, and no change occurred in Ki for sulphobromophthalein inhibition. Significantly lower enzyme specific activities were found for three of the activities studied in female rats but no difference was observed in the S-alkyltransferase activity. However, the proportional increase in the enzymic activities in response to phenobarbital was the same in males and females. These studies demonstrate the drug induction of a group of cytosolic drug-metabolizing enzymes as well as the identification of sex differences in these activities.