A phase I study of Mirvetuximab Soravtansine and gemcitabine in patients with FRα-positive recurrent ovarian, primary peritoneal, fallopian tube, or endometrial cancer, or triple negative breast cancer

OBJECTIVE

Platinum-resistant epithelial ovarian cancer (EOC), recurrent endometrial cancer (EC), and triple negative breast cancer (TNBC) are difficult to treat after failing standard therapies. This phase I study evaluated mirvetuximab soravtansine (MIRV) and gemcitabine in patients with recurrent FRα-positive EOC, EC, or TNBC to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D) (primary endpoint).

METHODS

FRα-positive patients with platinum-resistant EOC, EC, or TNBC with ≤4 prior chemotherapy regimens (2 for EC) were enrolled. FRα expression requirement varied among eligible tumors and changed during the study.

RESULTS

Twenty patients were enrolled; 17 were evaluable for DLT. Half the patients received ≥3 prior chemotherapy lines. Most EOC and EC patients (78%) were medium (50-74%) or high(75-100%) FRα expressors. TNBC patients were low (25-49%) FRα expressors. The MTD/RP2D was MIRV 6 mg/kg AIBW D1 and gemcitabine 800 mg/m2 IV, D1 and D8, every 21 days (Dose Level [DL] 3), where 5/7 patients demonstrated a partial response (PR) as their best response, including 2 confirmed ovarian responses whose time-to-progression and duration of response were 7.9/5.4 and 8.0/5.7 months respectively. Most common treatment-related adverse events at MTD were anemia and neutropenia (3/7 each, 43%), diarrhea, hypophosphatemia, thrombocytopenia, and leukopenia (2/7 each, 29%). DLTs were thrombocytopenia (DL1), oral mucositis (DL4) and diarrhea (DL4). Nine of 20 patients (45%; 95% CI: 21.1-68.9%) achieved PR as their best response, with 3/20 patients or 15% (95%CI, 0-32.1%) confirmed PR.

CONCLUSION

MIRV and gemcitabine demonstrate promising activity in platinum resistant EOC at RP2D, but frequent hematologic toxicities.

Immunologic Signatures of Peripheral Blood T Cells Reveal the Outcome of p53MVA Vaccine and Pembrolizumab Treatment in Patients with Advanced Ovarian Cancer

PURPOSE

Our previous studies indicated that p53-reactive T cells were associated with clinical benefit in patients with advanced ovarian cancer who were treated with p53-expressing modified vaccinia Ankara (p53MVA) vaccine and gemcitabine chemotherapy. To replace chemotherapy with an approach that will enhance vaccine efficacy and antitumor immunity, we treated patients with p53MVA in combination with PD-1 checkpoint blocker, pembrolizumab. We also attempted to further characterize the activation status of T cells prior to vaccination and during treatment.

EXPERIMENTAL DESIGN

Patients received up to three triweekly vaccinations concurrent with pembrolizumab, followed by pembrolizumab monotherapy at 3-week intervals. Correlative studies analyzed peripheral blood T-cell phenotypes and profiles of immune function gene expression.

RESULTS

We observed 6/28 (21%) patients with a clinical benefit to therapy, including 3 partial responses (PR) and 3 patients with stable disease (SD) for 6+ months. The median progression-free survival was 1.8 months (95% confidence interval: 1.7-3.8) and median overall survival was 15.1 months (9.4-30.4). Two patients remain progression-free at 28 and 33 months. Of the 18 patients evaluable in correlative studies, 6 were immunologic responders of whom 5 had clinical benefit (3 PR, 2 SD). Immunologic non-responders expressed in pretreatment peripheral blood mononuclear cell samples high levels of mRNA for multiple molecules associated with terminally differentiated T cells.

CONCLUSIONS

p53MVA/pembrolizumab immunotherapy showed promising antitumor activity in patients who demonstrated functionally competent peripheral blood T cells. Detection of markers of terminally differentiated T cells before treatment may identify patients unlikely to respond to p53MVA/pembrolizumab.

SIGNIFICANCE

The activity of a combination immunotherapy of p53 vaccine and PD-1 checkpoint blockade in patients with platinum-resistant ovarian cancer was evaluated in a phase II trial. Clinical benefit was correlated with the responsive immune status of patients before and during the treatment, defining potential predictive markers for immune therapy.

Impact of Sodium Thiosulfate on Prevention of Nephrotoxicities in HIPEC: An Ancillary Evaluation of Cisplatin-Induced Toxicities in Ovarian Cancer

PURPOSE

Hyperthermic intraperitoneal chemotherapy (HIPEC) with cisplatin confers a survival benefit in epithelial ovarian cancer (EOC) but is associated with renal toxicity. Sodium thiosulfate (ST) is used for nephroprotection for HIPEC with cisplatin, but standard HIPEC practices vary.

METHODS

A prospective, nonrandomized, clinical trial evaluated safety outcomes of HIPEC with cisplatin 75 mg/m2 during cytoreductive surgery (CRS) in patients with EOC (n = 34) and endometrial cancer (n = 6). Twenty-one patients received no ST (nST), and 19 received ST. Adverse events (AEs) were reported according to CTCAE v.5.0. Serum creatinine (Cr) was collected preoperatively and postoperatively (Days 5-8). Progression-free survival (PFS) was followed. Normal peritoneum was biopsied before and after HIPEC for whole transcriptomic sequencing to identify RNAseq signatures correlating with AEs.

RESULTS

Forty patients had HIPEC at the time of interval or secondary CRS. Renal toxicities in the nST group were 33% any grade AE and 9% grade 3 AEs. The ST group demonstrated no renal AEs. Median postoperative Cr in the nST group was 1.1 mg/dL and 0.5 mg/dL in the ST group (p = 0.0001). Median change in Cr from preoperative to postoperative levels were + 53% (nST) compared with - 9.6% (ST) (p = 0.003). PFS did not differ between the ST and nST groups in primary or recurrent EOC patients. Renal AEs were associated with downregulation of metabolic pathways and upregulation of immune pathways.

CONCLUSIONS

ST significantly reduces acute renal toxicity associated with HIPEC with cisplatin in ovarian cancer patients. As nephrotoxicity is high in HIPEC with cisplatin, nephroprotective agents should be considered.

Safety and Efficacy of Oxaliplatin Pressurized Intraperitoneal Aerosolized Chemotherapy (PIPAC) in Colorectal and Appendiceal Cancer with Peritoneal Metastases: Results of a Multicenter Phase I Trial in the USA

BACKGROUND

Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a laparoscopic locoregional treatment for peritoneal metastases (PM) from colorectal cancer (CRC) or appendiceal cancer (AC) in patients who cannot undergo cytoreductive surgery (CRS). While PIPAC has been studied in Europe and Asia, it has not been investigated in the USA.

PATIENTS AND METHODS

We evaluated PIPAC with 90 mg/m2 oxaliplatin alone (cycle 1) and preceded by systemic chemotherapy with fluorouracil (5-FU) and leucovorin (LV) (cycle 2-3) as a multicenter prospective phase I clinical trial (NCT04329494). The primary endpoint was treatment-related adverse events (AEs). Secondary endpoints included survival and laparoscopic, histologic, and radiographic response.

RESULTS

12 patients were included: 8 with CRC and 4 with AC. Median prior chemotherapy cycles was 2 (interquartile range (IQR) 2-3). All patients were refractory to systemic oxaliplatin-based chemotherapy. Median peritoneal carcinomatosis index (PCI) was 28 (IQR 19-32). Six (50%) of twelve patients completed three PIPAC cycles. No surgical complications or dose-limiting toxicities were observed. Two patients developed grade 3 treatment-related toxicities (one abdominal pain and one anemia). Median overall survival (OS) was 12.0 months, and median progression-free survival (PFS) was 2.9 months. OS was correlated with stable disease by Response Evaluation Criteria in Solid Tumors (RECIST) criteria but not with laparoscopic response by PCI or histologic response by peritoneal regression grading system (PRGS).

CONCLUSIONS

This phase I trial in the USA demonstrated safety, feasibility, and early efficacy signal of PIPAC with oxaliplatin and chemotherapy in patients with PM from AC or CRC who are refractory to standard lines of systemic chemotherapy.

Multicenter dose-escalation Phase I trial of mitomycin C pressurized intraperitoneal aerosolized chemotherapy in combination with systemic chemotherapy for appendiceal and colorectal peritoneal metastases: rationale and design

Objectives

Peritoneal metastasis (PM) from appendiceal cancer or colorectal cancer (CRC) has significant morbidity and limited survival. Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a minimally invasive approach to treat PM. We aim to conduct a dose-escalation trial of mitomycin C (MMC)-PIPAC combined with systemic chemotherapy (FOLFIRI) in patients with PM from appendiceal cancer or CRC.

Methods

This is a multicenter Phase I study of MMC-PIPAC (NCT04329494). Inclusion criteria include treatment with at least 4 months of first- or second-line systemic chemotherapy with ineligibility for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Exclusion criteria are: progression on chemotherapy; extraperitoneal metastases; systemic chemotherapy intolerance; bowel obstruction; or poor performance status (ECOG>2). Escalating MMC-PIPAC doses (7-25 mg/m2) will be administered in combination with standard dose systemic FOLFIRI. Safety evaluation will be performed on 15 patients (dose escalation) and six expansion patients: 21 evaluable patients total.

Results

The primary endpoints are recommended MMC dose and safety of MMC-PIPAC with FOLFIRI. Secondary endpoints are assessment of response (by peritoneal regression grade score; Response Evaluation Criteria in Solid Tumors [RECIST 1.1], and peritoneal carcinomatosis index), progression free survival, overall survival, technical failure rate, surgical complications, conversion to curative-intent CRS-HIPEC, patient-reported outcomes, and functional status. Longitudinal blood and tissue specimens will be collected for translational correlatives including pharmacokinetics, circulating biomarkers, immune profiling, and single-cell transcriptomics.

Conclusions

This Phase I trial will establish the recommended dose of MMC-PIPAC in combination with FOLFIRI. Additionally, we expect to detect an early efficacy signal for further development of this therapeutic combination.

Left atrial venous arterial extracorporeal membrane oxygenation for biventricular failure in cardiogenic shock

Background

Cardiogenic shock complicated by biventricular (BIV) heart failure is associated with high mortality. Venous-arterial extra-corporeal membrane oxygenation is limited by the increase of left ventricular (LV) afterload. Complex configurations of paired circulatory support devices have been used with mixed results due to vascular access complications. One way to simply vascular access is to place a transseptal cannula under echocardiographic guidance with a long fenestrated segment enabling simultaneous left and right sided unloading known as left-atrial venous arterial (LAVA) ECMO.

Purpose

We aimed to review the safety and outcomes of LAVA ECMO utilized for shock at our institution.

Methods

Retrospective analysis of our Hospital Cath Lab Database yielded 6 patients undergoing LAVA-ECMO for shock from 7/2020–3/2021. Patient characteristics, procedural data and outcomes were analyzed. Variables are either expressed as proportions or medians (Interquartile range; IQR).

Results

Median age was 55.5 years (IQR, 51–61) and most patients were men (83.3%). Median baseline LV ejection fraction was 38% (IQR, 23–56%) and all had right ventricular dysfunction. 4/6 (66.7%) had severe valvular dysfunction including aortic regurgitation (2/6), mitral regurgitation (2/6) and mitral stenosis (1/6). One patient had a LV thrombus and hemodynamics necessitated LV unloading. Intracardiac echocardiography was used to guide the transseptal puncture in 5/6 (83%). Transesophageal echocardiography was used in one case. Procedural outcomes and hemodynamic variables are outlined in Tables 1 and 2 consecutively. One case of limb ischemia resulted from an embolus in the contralateral limb. LAVA-ECMO bridged 83% of patients to valve replacement, durable ventricular support or heart transplant (Table 1).

Conclusions

LAVA-ECMO provides BIV support with a single circuit and successfully bridged patients without direct complications. Given the safety, efficacy and simplified configuration of LAVA-ECMO, prospective studies are indicated.

Funding Acknowledgement

Type of funding sources: None.

Use of left ventricular support devices during transcatheter aortic valve replacement and balloon aortic valvuloplasty: a single center experience

Background

Transcatheter aortic valve replacement (TAVR) and balloon aortic valvuloplasty (BAV) are definitive and bridging therapies in patients with aortic stenosis. Data on utilization of mechanical circulatory support (MCS) in this population is scarce. This study sought to evaluate the clinical outcomes of the use of Impella (Abiomed, Danvers, MA) in patients undergoing TAVR or BAV at a tertiary-care center.

Methods

We reviewed all TAVRs and BAVs that required Impella from 2012 and 2020. Patient demographics, procedural outcomes, complications, and 30-day mortality were analyzed.

Results

A total of 1,965 TAVR and 715 BAV cases were performed in the study period. 30 TAVR and 94 BAV cases required an Impella. 65% of these cases were due to cardiogenic shock (CS) (100% of TAVR and 55% of BAV). 31% were performed in female patients. Transfemoral access was utilized in 98% of cases. Impella CP was used in 98% of cases, other types of MCS were used in 8.7% of cases. 32.2% of cases required MCS for more than 24 hours. In the TAVR population the indication for MCS was 46.6% profound hypotension post valve deployment requiring vasopressors, 16.6% cardiac arrest, 10% sustained ventricular arrhythmia, 10% cardiac tamponade [Office1] and 10% coronary occlusion. In the BAV group the indication was 44% high-risk PCI and 56% CS. The 30-day mortality in TAVR was 40% and 28% in BAV; from the BAV group in CS the mortality was 45%. VARC-2 vascular complications and bleeding complications were observed in 4.8% and 1.5%, respectively. 0.7% of the total cohort required conversion to open-heart surgery.

Conclusions

Impella support is required in a minority of TAVR or BAV cases. In those who require MCS with Impella for either BAV or TAVR, the total mortality remains high especially in those experiencing CS.

Funding Acknowledgement

Type of funding sources: None.

Pediatric COVID-19 Cases in Counties With and Without School Mask Requirements - United States, July 1-September 4, 2021

Consistent and correct mask use is a critical strategy for preventing the transmission of SARS-CoV-2, the virus that causes COVID-19 (1). CDC recommends that schools require universal indoor mask use for students, staff members, and others in kindergarten through grade 12 (K-12) school settings (2). As U.S. schools opened for the 2021-22 school year in the midst of increasing community spread of COVID-19, some states, counties, and school districts implemented mask requirements in schools. To assess the impact of masking in schools on COVID-19 incidence among K-12 students across the United States, CDC assessed differences between county-level pediatric COVID-19 case rates in schools with and without school mask requirements.

A phase I study of mirvetuximab soravtansine (MIRV) and gemcitabine (G) in patients (Pts) with selected frα-positive solid tumors: Results in the ovarian cancer (EC) cohort

5542

Background: Mirvetuximab soravtansine (MIRV) is an ADC comprising a FRα-binding antibody, cleavable linker, and the maytansinoid DM4, a potent tubulin-targeting agent. MIRV has promising single agent activity in FRα-positive medium/high expression epithelial ovarian cancer (EOC), at 6 mg/kg, based on adjusted ideal body weight (AIBW) IV every (q) 21 days. This study evaluated MIRV and G in recurrent EOC, endometrial and triple negative breast cancer. The recommended phase 2 dose (RP2D) was established at MIRV 6 mg/kg AIBW IV, day 1 and G 800 mg/m2 IV, d1, 8 q21 days (J Clin Oncol 37, 2019, Abs. #3009). Here we report the results from the EOC cohort. Methods: Patients (pts) with FRα-positive platinum resistant EOC with ≤4 prior chemotherapy (CT) regimens, were eligible. FRα positivity was initially defined as ≥ 25% of cells with PS2+ staining intensity (low to high FRα expression) and was subsequently revised to require medium/high FRα expression (≥50%/ ≥75% of cells with PS2+ staining intensity). Results: From 10/2017 to 12/2020, 113 EOC pts underwent FRα screening, with 74 FRα-positive results. Thirty total EOC pts (with median 3 prior lines of therapy) were treated; 8 pts during dose escalation and 22 EOC pts at the RP2D (all evaluable for response). Fifteen (50%) pts had high FRα, 10 pts (33%) medium FRα, and 5 pts (17%) low FRα expression. Eleven (36%) of the 30 EOC pts achieved a partial response (PR), 15 pts (50%) had SD and 4 pts (13%) progressed. Among the 11 responders, 5 pts had high FRα, 4 pts medium FRα and 2 pts low FRα expression. Non-heme clinically significant adverse events (AEs) included: G2 sensory neuropathy (4 pts) G3 diarrhea (3 pts), G3 fatigue (2 pts), G3 pneumonitis (2 pts), and 1 pt with G5 respiratory failure (secondary to pneumonia but drug-induced pneumonitis could not be ruled out). Conclusions: MIRV in combination with G has promising clinical activity in late line platinum resistant FRα-positive EOC, with best responses observed in high FRα expression. The regimen is well tolerated with expected AEs based on the known toxicities of each agent. This study was approved and funded by the National Comprehensive Cancer Network (NCCN) Oncology Research Program from general research support provided by ImmunoGen Corp and Cancer Center Support Grant P30CA033572. Clinical trial information: NCT02996825.

A phase I study of mirvetuximab soravtansine (IMGN853) and gemcitabine (G) in patients with FOLR1-positive recurrent epithelial ovarian (EOC), endometrial cancer (EC), or triple-negative breast cancer (TNBC)

3009

Background: IMGN853 is an antibody-drug conjugate targeting the folate receptor alpha (FOLR1), linked to maytansinoid, DM4. IMGN853 has promising single agent activity in FOLR1+ EOC. The recommended phase 2 dose (RP2D) is 6 mg/kg, based on adjusted ideal body weight (AIBW) IV every 3 wks. This study evaluates IMGN853 and G. Methods: Patients (pts) with FOLR1+ tumors including: platinum resistant EOC with ≤4 prior chemotherapy (CT) regimens, EC with ≤2 CT and TNBC ≤4 CT are eligible. FOLR1 + is defined as ≥25% of tumor staining (all tumors) ≥2+ intensity (EOC, EC) and ≥1+ (TNBC). A standard 3+3 design combines IMGN853 and G. EOC pts undergo one research biopsy to assess intratumoral vs. circulating DM4 level and biopsy vs. archival tissue FOLR1 expression. Dose-limiting toxicity (DLT) is assessed during cycle 1. Responses as per RECIST 1.1 are assessed at 12 wks. and adverse events (AEs) are evaluated by CTCAE v4.0. Results: From 10/2017 to 1/2019 a total of 15 pts. were treated (3 additional pts have consented on dose level [DL] 4):10 EOC, 3 EC and 2 TNBC. One pt. on DL1 had grade (G) 4 thrombocytopenia (PLT) DLT. Three pts were inevaluable for DLT and were replaced: 1 pt. at DL1 with G4 neutropenia without fever of unknown duration due to delayed follow up blood work, 1 pt. at DL2 and 1 pt. at DL3 due to incomplete cycle 1. No DLTs were observed on DL2-3. Day 8 cycle 1 dose modifications were required in 3 of 4 patients on DL3 (for mucositis [1 pt.], and PLT [2 pts]). We are now enrolling at the RP2D for both agents, and MTD will be determined prior to May 2019. Conclusions: IMGN853 in combination with G is achievable at clinically relevant doses and the recommended Phase 2 dose and MTD will be reported. Support: NCCN grant; with support from ImmunoGen Corp and Cancer Center Support Grant P30CA033572. Clinical trial information: NCT02996825. [Table: see text]

p53-Reactive T Cells Are Associated with Clinical Benefit in Patients with Platinum-Resistant Epithelial Ovarian Cancer After Treatment with a p53 Vaccine and Gemcitabine Chemotherapy

Purpose: To conduct a phase I trial of a Modified Vaccinia Ankara vaccine delivering wild-type human p53 (p53MVA) in combination with gemcitabine chemotherapy in patients with platinum-resistant ovarian cancer.Experimental Design: Patients received gemcitabine on days 1 and 8 and p53MVA vaccine on day 15, during the first 3 cycles of chemotherapy. Toxicity was classified using the NCI Common Toxicity Criteria and clinical response assessed by CT scan. Peripheral blood samples were collected for immunophenotyping and monitoring of anti-p53 immune responses.Results: Eleven patients were evaluated for p53MVA/gemcitabine toxicity, clinical outcome, and immunologic response.

TOXICITY

there were no DLTs, but 3 of 11 patients came off study early due to gemcitabine-attributed adverse events (AE). Minimal AEs were attributed to p53MVA vaccination. Immunologic and clinical response: enhanced in vitro recognition of p53 peptides was detectable after immunization in both the CD4⁺ and CD8⁺ T-cell compartments in 5 of 11 and 6 of 11 patients, respectively. Changes in peripheral T regulatory cells (Tregs) and myeloid-derived suppressor cells (MDSC) did not correlate significantly with vaccine response or progression-free survival (PFS). Patients with the greatest expansion of p53-reactive T cells had significantly longer PFS than patients with lower p53-reactivity after therapy. Tumor shrinkage or disease stabilization occurred in 4 patients.Conclusions: p53MVA was well tolerated, but gemcitabine without steroid pretreatment was intolerable in some patients. However, elevated p53-reactive CD4⁺ and CD8⁺ T-cell responses after therapy correlated with longer PFS. Therefore, if responses to p53MVA can be enhanced with alternative agents, superior clinical responses may be achievable. Clin Cancer Res; 24(6); 1315-25. ©2018 AACR.

Focal defects in single-celled tubes mutant for Cerebral cavernous malformation 3, GCKIII, or NSF2

Tubes of differing cellular architecture connect into networks. In the Drosophila tracheal system, two tube types connect within single cells (terminal cells); however, the genes that mediate this interconnection are unknown. Here we characterize two genes that are essential for this process: lotus, required for maintaining a connection between the tubes, and wheezy, required to prevent local tube dilation. We find that lotus encodes N-ethylmaleimide sensitive factor 2 (NSF2), whereas wheezy encodes Germinal center kinase III (GCKIII). GCKIIIs are effectors of Cerebral cavernous malformation 3 (CCM3), a protein mutated in vascular disease. Depletion of Ccm3 by RNA interference phenocopies wheezy; thus, CCM3 and GCKIII, which prevent capillary dilation in humans, prevent tube dilation in Drosophila trachea. Ectopic junctional and apical proteins are present in wheezy terminal cells, and we show that tube dilation is suppressed by reduction of NSF2, of the apical determinant Crumbs, or of septate junction protein Varicose.

Risk of falling in Parkinson's disease at the Hoehn-Yahr stage III

BACKGROUND

It is difficult to predict the risk of falling, especially in patients with good motor ability, and the mechanisms underlying the relation between gait patterns and falling in Parkinson's disease (PD) remain unclear. We investigated factors related to falling, including walking speed and time, in patients with Hoehn-Yahr stage III PD.

METHODS

We performed clinical assessments and evaluated balance in 30 patients with PD. Information on falling was obtained from questionnaires and personal interviews. Gait patterns were analyzed with the use of an originally designed, suddenly narrowed path.

RESULTS

Gait velocity was slower in fallers than in non-fallers (p = 0.047). Unified Parkinson's Disease Rating Scale part II (UPDRS part II) score, fear of falling, and gait velocity were significantly related to falling on analysis with a single logistic model. When a multiple logistic model was used, the UPDRS part II score was significantly related to falling (OR: 1.48, p = 0.037, 95% CI: 1.02-2.16).

CONCLUSIONS

Patients with Hoehn-Yahr stage III PD showed slow gait velocity attributed to fear of falling before arrival at a narrowed entrance or while walking on a narrowed path. The UPDRS part II score is significantly related to the risk of future falls.

Selective differentiation of central nervous system–derived stem cells in response to cues from specific regions of the developing brain

Object

Each region of the brain is distinguished by specific and distinct markers and functions. The authors hypothesized that each region possesses unique trophic properties that dictate and maintain its development. To test this hypothesis, they isolated central nervous system (CNS) stem cells from fetal rodents, and these rat CNS-derived stem cells (RSCs) were placed in coculture with primary cultures of the developing neonatal hippocampus and hypothalamus to determine whether region-specific primary cells would direct the differentiation of stem cells in a region-specific manner.

Methods

Primary cultures were first established from the neonatal (3–7 days postnatal) hippocampus and hypothalamus. Rodent CNS stem cells, which had been genetically engineered to express green fluorescent protein, were then placed in coculture with the primary CNS cells. The expression of region-specific markers in the RSCs was then evaluated after 2 weeks using immunocytochemistry. Data from previous studies have indicated that primary adult cells lack a differentiation-inducing capacity.

Results

When placed in coculture with primary CNS cells, RSCs began to express both neuronal (MAP2) and glial (glial fibrillary acidic protein) markers. Those that were placed in coculture with hippocampal cells expressed region-specific markers such as γ-aminobutyric acid, whereas those placed in coculture with hypothalamic cells expressed growth hormone–releasing hormone primarily in the hypothalamus.

Conclusions

Pluripotential RSCs were induced to express region-specific phenotypes on coculture with primary cells derived from the developing hippocampus and hypothalamus. The differentiation of RSCs into specific lineages on exposure to specific cell types is likely modulated through direct cell–cell contact. Secreted factors from the primary neural cells may also play a role in this induction. Such a differentiation influence is also likely age dependent.

Comparative study of torsional and bending properties for six models of nickel-titanium root canal instruments with different cross-sections

This study investigated the influence of cross-section profile on the mechanical behaviors of six commercial nickel-titanium (NiTi) root canal instruments using the finite element method. The nonlinear mechanical characteristics of the NiTi alloy were taken into account. The six root canal instruments studied were ProTaper, Hero642, Mtwo, ProFile, Quantec, and NiTiflex. Mathematical models for these instruments were constructed and their performances were analyzed under equal torque conditions. The ProTaper and Hero642 models achieved the lowest stress levels that made them the most torque-resistant while the NiTiflex model was the poorest. The maximum stress value and the stress distribution in a model were found strongly influenced by the cross-section profile. Factors affecting the stress distribution include the cross-sectional inertia, depth of the flute, area of the inner core, radial land, and peripheral surface ground. As the area of the inner core of the cross-section increased, the model was more torque-resistant.

Components of olive oil and chemoprevention of colorectal cancer

Olive oil contains a vast range of substances such as monounsaturated free fatty acids (e.g., oleic acid), hydrocarbon squalene, tocopherols, aroma components, and phenolic compounds. Higher consumption of olive oil is considered the hallmark of the traditional Mediterranean diet, which has been associated with low incidence and prevalence of cancer, including colorectal cancer. The anticancer properties of olive oil have been attributed to its high levels of monounsaturated fatty acids, squalene, tocopherols, and phenolic compounds. Nevertheless, there is a growing interest in studying the role of olive oil phenolics in carcinogenesis. This review aims to provide an overview of the relationship between olive oil phenolics and colorectal cancer, in particular summarizing the epidemiologic, in vitro, cellular, and animal studies on antioxidant and anticarcinogenic effects of olive oil phenolics.

Antimetastatic activity of a cyclooxygenase-2 inhibitor

Cyclooxygenase-2 (COX-2) expression is increased in breast cancer and surgery has been shown to increase the growth of metastatic tumours. We investigated the effect of selective COX-2 inhibition on the growth of metastases in either an experimental metastasis model or following excision of a murine primary breast tumour. 50 000 4T1 mammary carcinoma cells were injected into the mammary fat pad of female BALB/c mice. When the mean TD reached 8±0.4 mm, tumours were excised and the mice were randomised into two groups (n=12 per group) to receive daily intraperitoneal injections of the selective COX-2 inhibitor, SC-236 or drug vehicle for 14 days. Alternatively, experimental metastases were established by tail-vein injection of 50 000 4T1 cells. Mice received either the selective COX-2 inhibitor, SC-236 or drug vehicle for 14 days (n=12 per group). SC-236 treatment significantly reduced tumour burden, the number and size of spontaneous metastases following primary tumour excision. SC-236 treatment also reduced tumour burden, the number and size of experimental metastases. Immunohistochemical staining demonstrated that COX-2 inhibition reduced microvessel density and increased apoptosis within both spontaneous and experimental metastases. These data clearly demonstrate that the selective COX-2 inhibitor, SC-236, has potent antimetastatic activity against both spontaneous metastases arising following primary tumour excision and experimental metastases.

Bile acid concentrations, cytotoxicity, and pH of fecal water from patients with colorectal adenomas

In the multistage model of human colorectal tumorigenesis, both genetic and environmental factors play an important role. The identity of the environmental factors involved, however, still remains to be elucidated. As fecal bile acids are proposed as candidates, we compared the concentration of bile acids in fecal water from patients at different risk of developing colorectal cancer. In addition, pH of fecal water as well as its cytotoxicity to HT-29 colonic cells was determined. The high-risk group consisted of individuals diagnosed with one or more (tubulo)villous colorectal adenomas larger than 1 cm in diameter and containing moderate or severe dysplasia (N = 20). Subjects with colorectal adenomas smaller than 1 cm and showing only minor dysplasia were assigned to the medium risk group (N = 19). The control group consisted of persons with normal findings by colonoscopy (N = 25). The results show no significant differences in fecal water bile acid concentrations between the three groups. However, 46% of the observed cytotoxicity is explained in a regression model that includes pH and the concentrations of deoxycholic acid, cholic acid, and ursodeoxycholic acid. The pH of fecal water is found to be significantly lower in the high risk group as compared to the controls, suggesting that a relatively high fecal pH has a protective effect on the development of colorectal adenomas. Although hyperproliferation as a result of cytotoxicity has been suggested to contribute to tumor formation in the colon, the pH-dependent cytotoxicity of bile acids in fecal water was not found to be associated with adenoma formation in the present study.

Phase I clinical and pharmacologic study of weekly cisplatin combined with weekly irinotecan in patients with advanced solid tumors

PURPOSE

In vitro synergy between cisplatin and irinotecan (CPT-11) has been reported. We designed a combination schedule of these agents to maximize the potential for synergistic interaction.

PATIENTS AND METHODS

To maximize the opportunity for synergy, we divided the cisplatin into four consecutive weekly treatments, followed by a 2-week rest. Each dose of cisplatin was immediately followed by a dose of irinotecan. The dose of cisplatin was fixed at 30 mg/m2/wk. The initial irinotecan dose was 50 mg/m2/wk and this was escalated by 30% increments in successive cohorts of three to six patients to establish the maximum-tolerated dose (MTD). Pharmacokinetics of irinotecan and its metabolites, SN-38 and SN-38 glucuronide (SN-38G), were analyzed.

RESULTS

Of 35 patients with solid tumors enrolled onto this trial, 30 were assessable for toxicity and response. The MTD for this regimen was 30 mg/m2/wk of cisplatin plus 50 mg/m2/wk of irinotecan in previously treated patients and 30 mg/m2/wk of cisplatin plus 65 mg/m2/wk of irinotecan in chemotherapy-naive patients. Neutropenia was the dose-limiting toxicity (DLT) encountered in this trial. Diarrhea was infrequent and rarely dose-limiting. Seven of 30 assessable patients achieved a partial response. No alteration in irinotecan, SN-38, or SN-38G pharmacokinetics resulted from the administration of cisplatin with irinotecan.

CONCLUSION

The administration of cisplatin and irinotecan on this weekly schedule provides a practical and well-tolerated regimen that has the potential to maximize any clinical synergy between the two agents. Evidence of substantial clinical activity was seen in this phase I study.

Clinical relevance of the distinction between alcohol dependence with and without a physiological component

OBJECTIVE

DSM-IV indicates that diagnoses of substance dependence should be further characterized with regard to the presence of a physiological component, defined by tolerance or withdrawal. This study evaluated the possible meaning of this distinction in alcohol-dependent men and women.

METHOD

As part of the Collaborative Study on the Genetics of Alcoholism, structured interviews were carried out with 3,395 DSM-III-R-defined alcohol-dependent individuals divided into 2,949 subjects (86.9%) with evidence of tolerance and/or withdrawal (group 1), 51.3% of whom evidenced withdrawal symptoms, and 446 subjects (13.1%) without a physiological component (group 2). Data were evaluated to determine differences between the two groups.

RESULTS

Group 1 reported greater severity of alcohol dependence as demonstrated by a larger maximum number of drinks in 24 hours, more persons reporting binges, more alcohol-related life problems, more relevant DSM-III-R criteria endorsed, more physiological complications, and more alcohol-related emotional/psychiatric symptoms such as depression and anxiety. Each of these severity indicators for problems in group 1 was significant in the presence of the others in a logistic regression, and similar items remained significant when tolerance alone, withdrawal alone, or their combination was used as the criterion for group 1 membership; however, for withdrawal a larger proportion of the variance was explained by the predictor variables. The regression results were independent of gender, proband status, and history of antisocial personality disorder.

CONCLUSIONS

The results support the clinical relevance of distinguishing between alcohol-dependent patients with and without a physiological component. The data indicate a potential advantage to limiting that definition to withdrawal only.

Formulation development and primary degradation pathways for recombinant human nerve growth factor

The chemical and physical stabilities of recombinant human nerve growth factor (NGF) in aqueous solution were investigated between 5 and 37 degrees C and at pH 4.2-5.8. NGF chemical stability decreased with a decrease in pH due to Asp60-Pro61 cleavage, with the stability being greater in acetate buffer than in succinate buffer at each pH investigated. Aggregation was a significant degradation pathway at 37 degrees C, with the aggregation rate being greatest in succinate buffer at pH 5.8. Quantitation of NGF degradation by cation-exchange chromatography was complicated by the rearrangement of the NGF monomer variants into various mixed dimers over time. Treatment with dilute acid brought the dimer distribution rapidly to equilibrium, allowing NGF degradation to be accurately quantitated. An acetate-buffered formulation at pH 5.5 was investigated in more detail. To assist in degradation product identification, NGF degradation was accelerated with base, hydrogen peroxide, and temperature. These degradation products were shown to coelute on RP-HPLC with the variants found when the protein was stored at -70, 5, and 25 degrees C. By electrospray mass spectrometry, peptide maps, and LC/MS, these degradation products were shown to be monooxidized (Met37) and dioxidized (Met37 and Met92) NGF, with Met37 being more labile, deamidated NGF (Asn45), and NGF with Asp93 isomerized to beta-Asp93. NGF can be stored in pH 5.5 acetate buffer at 5 degrees C for 1.5 years with less than 10% conversion to these degradation products, with Asp93 isomerization being the primary degradation pathway.

Phase I clinical and pharmacokinetic study of irinotecan, fluorouracil, and leucovorin in patients with advanced solid tumors

PURPOSE

To determine the maximum-tolerable dose (MTD) of fluorouracil (5FU) when given with fixed doses of leucovorin and irinotecan (CPT-11), to define the dose-limiting toxicities of this combination, and to evaluate the effect of 5FU on the pharmacokinetics of CPT-11.

PATIENTS AND METHODS

CPT-11, leucovorin, and 5FU were administered in repeated 6-week cycles that consisted of weekly treatment with all three drugs for 4 consecutive weeks followed by a 2-week break. On day 1 of treatment, CPT-11 alone was given by 90-minute infusion, and pharmacokinetic sampling was performed over 24 hours. Leucovorin and 5FU were administered by brief intravenous injection on day 2. On days 8, 15, and 22, CPT-11 infusion was immediately followed by leucovorin and then 5FU. A second 24-hour pharmacokinetic sampling was performed on day 8, which permitted comparison of the pharmacokinetics of CPT-11 with and without 5FU. For the second 6-week cycle, leucovorin was administered first, followed by 5FU and then CPT-11, and a third pharmacokinetic sampling was performed.

RESULTS

Forty-two patients were entered onto this trial. The CPT-11 dose was initially fixed at 100 mg/m2. Leucovorin was fixed at 20 mg/m2. 5FU doses of 210, 265, 340, 425, and 500 mg/m2 were studied. When the 500-mg/m2 dose of 5FU was found to be tolerable, this was then maintained and CPT-11 was escalated to 125 and then 150 mg/m2. This final CPT-11 dose exceeded the MTD. Neutropenia was the major dose-limiting toxicity. Diarrhea was common, but was rarely dose-limiting. Coadministration of 5FU had no substantial effect on the pharmacokinetics of CPT-11 or SN-38. Among the 38 patients with colorectal cancer, six partial responses (PRs) were seen in this predominantly 5FU-refractory patient population.

CONCLUSION

5FU does not substantially affect the metabolism of CPT-11 to its active metabolite, SN-38. The combination of CPT-11125 mg/m2, 5FU 500 mg/m2, and leucovorin 20 mg/m2 is feasible and tolerable on this schedule.

The importance of standardization of carboxymethylchitin concentration by the dye-binding capacity of alcian blue before adsorption on liposomes

A new method based on the measurement of the relative dye-binding capacity of Alcian Blue to carboxymethylchitin (CMC) at various molecular weights (MW) has been developed to facilitate the standardization of the initial polyelectrolyte concentration. In the absence of standardization, non-reproducible adsorption patterns are encountered during the adsorption of the MW CMC on neutral and positively charged liposomes. This method is sensitive down to a concentration of 5 mu g/ml of polymer in water. Static Light Scattering (SLS) measurements are used to obtain the weight average molecular weight (Mw) and the size of the polyelectrolyte (Rg) and overlap concentrations (c*). The Mws are then used to determine the constants K and a of the Mark-Houwink equation which are 1.65 x 10(-2) dl/g and 0.4701, respectively, evaluated at kappa = 0.154 M, pH = 7.4 and T = 25 degrees C. The critical electrolyte concentration decreases with molecular weight for Mws ranging from 5.0 x 10(4)-1.2 x 10(6). The dye-binding capacity changes with the molecular weight distribution of the polyelectrolyte demonstrating the sensitivity of this technique to polydispersity.

Chemical heterogeneity as a result of hydroxylamine cleavage of a fusion protein of human insulin-like growth factor I

Recombinant DNA techniques were used to biosynthesize human insulin-like growth factor I (hIGF-I) as a fusion protein wherein the fusion polypeptide is an IgG-binding moiety derived from staphylococcal protein A. This fusion protein is produced in Escherichia coli and secreted into the fermentation broth. In order to release mature recombinant-derived hIGF-I (rhIGF-I), the fusion protein is treated with hydroxylamine, which cleaves a susceptible Asn-Gly bond that has been engineered into the fusion protein gene. Reversed-phase h.p.l.c. was used to estimate the purity of the rhIGF-I preparations, especially for the quantification of the methionine sulphoxide-containing variant. It was determined that hydroxylamine cleavage of the fusion protein produced, as a side reaction, hydroxamates of the asparagine and glutamine residues in rhIGF-I. Although isoelectric focusing was effective in detecting, and reversed-phase h.p.l.c. for producing enriched fractions of the hydroxamate variants, ion-exchange chromatography was a more definitive procedure, as it allowed quantification and facile removal of these variants. The identity of the variants as hydroxamates was established by Staphylococcus aureus V8 proteinase digestion, followed by m.s., as the modification was transparent to amino acid and N-terminal sequence analyses. The biological activity of rhIGF-I was established by its ability to incorporate [3H]thymidine into the DNA of BALB/c373 cells and by a radioreceptor assay utilizing human placental membranes. Both assays demonstrate that the native, recombinant and methionine sulphoxide and hydroxamate IGF-I variants are essentially equipotent.

Hepatocyte iron release in rats

Hepatocyte iron release was studied in vivo in rats. After the injection of iron 59-labeled ferritin, hemoglobin, or human asialotransferrin, the proportions of the radioactive iron returned to the plasma and incorporated into stores were determined under various conditions. Iron 55-labeled rat transferrin was injected at the same time as the 59Fe-labeled compound, and storage iron release was calculated from the cumulative incorporation of the two isotopes in the red cell mass over 2 weeks. The various 59Fe-labeled compounds were processed differently by the hepatocyte, but the radioactive iron was incorporated in the same iron stores. About 6% of the hepatocyte storage iron was released daily in normal rats, but a pool of iron that is not mobilized spontaneously was clearly identified in iron overload. Iron turnover in the hepatocyte was regulated by the rate of erythropoiesis and iron status of the animal, and inflammation blocked hepatocyte iron release. A strong correlation between hepatocyte iron release and plasma transferrin receptor levels was observed (p less than 0.001), suggesting that plasma transferrin receptors could mediate the regulation of hepatocyte iron mobilization in rats.

Stress analysis of a total hip acetabular component: an FEM study

A stress analysis of a total hip acetabular component was performed using three-dimensional finite element modeling. The model consisted of 548 four-noded quadrilateral shell elements with 582 nodes. A worst-case support condition was assumed in which bony contact with small areas of the ilium, ischium, and pubis was represented by three-point support. Loads corresponding to the peak pressures developed in the hip when rising from a seated position--the activity contributing most to the fatigue of a prosthesis--were applied to the model. Peak stresses of 490 MPa are predicted around a screw hole in the region of greatest loading; according to the fatigue curve for porous-coated Ti-6Al-4V alloy, this translates into a component life of three years. When the area of bony support for the prosthesis is increased by a factor of 1.5, the fatigue life is more than doubled to seven years. The addition of restraints around the loaded hole to represent the placement of a screw extends the lifetime dramatically to 65 years. Substituting the material properties of cobalt-chromium alloy increases the predicted lifetime of the component to twelve years. We conclude that poor bone support can compromise the service life of titanium alloy acetabular components. Furthermore, we suggest that screw fixation be used to secure the prosthesis in the anterior-superior region if the prosthesis is not well supported by bone in the acetabulum.