Efficacy of the nanoparticle-drug conjugate CRLX101 in combination with bevacizumab in metastatic renal cell carcinoma: results of an investigator-initiated phase I-IIa clinical trial.

BACKGROUND: Anti-angiogenic therapies are effective in metastatic renal cell carcinoma (mRCC), but resistance is inevitable. A dual-inhibition strategy focused on hypoxia-inducible factor (HIF) is hypothesized to be active in this refractory setting. CRLX101 is an investigational camptothecin-containing nanoparticle-drug conjugate (NDC), which durably inhibits HIF1α and HIF2α in preclinical models and in gastric cancer patients. Synergy was observed in the preclinical setting when combining this NDC and anti-angiogenic agents, including bevacizumab. PATIENTS AND METHODS: Patients with refractory mRCC were treated every 2 weeks with bevacizumab (10 mg/kg) and escalating doses of CRLX101 (12, 15 mg/m(2)) in a 3 + 3 phase I design. An expansion cohort of 10 patients was treated at the recommended phase II dose (RP2D). Patients were treated until progressive disease or prohibitive toxicity. Adverse events (AEs) were assessed using CTCAE v4.0 and clinical outcome using RECIST v1.1. RESULTS: Twenty-two patients were response-evaluable in an investigator-initiated trial at two academic medical centers. RCC histologies included clear cell (n = 12), papillary (n = 5), chromophobe (n = 2), and unclassified (n = 3). Patients received a median of two prior therapies, with at least one prior vascular endothelial tyrosine kinase inhibitor therapy (VEGF-TKI). No dose-limiting toxicities were observed. Grade ≥3 AEs related to CRLX101 included non-infectious cystitis (5 events), fatigue (3 events), anemia (2 events), diarrhea (2 events), dizziness (2 events), and 7 other individual events. Five of 22 patients (23%) achieved partial responses, including 3 of 12 patients with clear cell histology and 2 of 10 patients (20%) with non-clear cell histology. Twelve of 22 patients (55%) achieved progression-free survival (PFS) of >4 months. CONCLUSIONS: CRLX101 combined with bevacizumab is safe in mRCC. This combination fulfilled the protocol's predefined threshold for further examination with responses and prolonged PFS in a heavily pretreated population. A randomized phase II clinical trial in mRCC of this combination is ongoing.

Chimerism, graft survival, and withdrawal of immunosuppressive drugs in HLA matched and mismatched patients after living donor kidney and hematopoietic cell transplantation.

Thirty-eight HLA matched and mismatched patients given combined living donor kidney and enriched CD34(+) hematopoietic cell transplants were enrolled in tolerance protocols using posttransplant conditioning with total lymphoid irradiation and anti-thymocyte globulin. Persistent chimerism for at least 6 months was associated with successful complete withdrawal of immunosuppressive drugs in 16 of 22 matched patients without rejection episodes or kidney disease recurrence with up to 5 years follow up thereafter. One patient is in the midst of withdrawal and five are on maintenance drugs. Persistent mixed chimerism was achieved in some haplotype matched patients for at least 12 months by increasing the dose of T cells and CD34(+) cells infused as compared to matched recipients in a dose escalation study. Success of drug withdrawal in chimeric mismatched patients remains to be determined. None of the 38 patients had kidney graft loss or graft versus host disease with up to 14 years of observation. In conclusion, complete immunosuppressive drug withdrawal could be achieved thus far with the tolerance induction regimen in HLA matched patients with uniform long-term graft survival in all patients.

Inhibition of αvß6 promotes acute renal allograft rejection in nonhuman primates.

The integrin αvß6 activates latent transforming growth factor-ß (TGF-ß) within the kidney and may be a target for the prevention of chronic allograft fibrosis after kidney transplantation. However, TGF-ß also has known immunosuppressive properties that are exploited by calcineurin inhibitors (CNIs); thus, the net benefit of αvß6 inhibition remains undetermined. To assess the acute impact of interference with αvß6 on acute rejection, we tested a humanized αvß6-specific monoclonal antibody (STX-100) in a randomized, double-blinded, placebo-controlled nonhuman primate renal transplantation study to evaluate whether αvß6 blockade alters the risk of acute rejection during CNI-based immunosuppression. Rhesus monkeys underwent renal allotransplantation under standard CNI-based maintenance immunosuppression; 10 biopsy-confirmed rejection-free animals were randomized to receive weekly STX-100 or placebo. Animals treated with STX-100 experienced significantly decreased rejection-free survival compared to placebo animals (p = 0.049). Immunohistochemical analysis confirmed αvß6 ligand presence, and αvß6 staining intensity was lower in STX-100-treated animals (p = 0.055), indicating an apparent blockade effect of STX-100. LAP, LTBP-1 and TGF-ß were all decreased in animals that rejected on STX-100 compared to those that rejected on standard immunosuppression alone, suggesting a relevant effect of αvß6 blockade on local TGF-ß. These data caution against the use of αvß6 blockade to achieve TGF-ß inhibition in kidney transplantation.

Scaling laws for melting ice avalanches.

This Letter describes an investigation of interfacial melting in ice-bearing granular flows. It is proposed that energy associated with granular collisions causes melting at an ice particle's surface, which can thus occur at temperatures well below freezing. A laboratory experiment has been designed that allows quantification of this process and its effect on the dynamics of a granular shear flow of ice spheres. This experiment employs a rotating drum, half filled with ice particles, situated in a temperature controlled laboratory. Capillary forces between the wetted melted particle surfaces lead to the clumping of particles and enhanced flow speeds, in turn leading to further melting. Dimensional analysis defines a parameter space for further experimentation.

Bayesian analysis of longitudinal Johne's disease diagnostic data without a gold standard test.

A Bayesian methodology was developed based on a latent change-point model to evaluate the performance of milk ELISA and fecal culture tests for longitudinal Johne's disease diagnostic data. The situation of no perfect reference test was considered; that is, no "gold standard." A change-point process with a Weibull survival hazard function was used to model the progression of the hidden disease status. The model adjusted for the fixed effects of covariate variables and random effects of subject on the diagnostic testing procedure. Markov chain Monte Carlo methods were used to compute the posterior estimates of the model parameters that provide the basis for inference concerning the accuracy of the diagnostic procedure. Based on the Bayesian approach, the posterior probability distribution of the change-point onset time can be obtained and used as a criterion for infection diagnosis. An application is presented to an analysis of ELISA and fecal culture test outcomes in the diagnostic testing of paratuberculosis (Johne's disease) for a Danish longitudinal study from January 2000 to March 2003. The posterior probability criterion based on the Bayesian model with 4 repeated observations has an area under the receiver operating characteristic curve (AUC) of 0.984, and is superior to the raw ELISA (AUC=0.911) and fecal culture (sensitivity=0.358, specificity=0.980) tests for Johne's disease diagnosis.

Estimating receiver operating characteristic curves with covariates when there is no perfect reference test for diagnosis of Johne's disease.

Paratuberculosis (Johne's disease) is a significant animal health problem. Evaluation of diagnostic tests for Johne's disease has been difficult due to lack of a gold standard test. In recent years, there has been interest in receiver operating characteristic (ROC) curve estimation without any gold standard test. Typically, either Bayesian or maximum likelihood methods are proposed. Although these methods overcome the lack of a gold standard test in ROC curve estimation, little work has been done to incorporate covariates in the analysis. In this paper, we propose a method for estimation of ROC curves based on statistical models to adjust for covariate effects when the true disease states of test animals are unknown. The covariates may be correlated with the disease process or with the diagnostic testing procedure, or both. We propose a 2-part Bayesian model: first, a logistic regression model for disease prevalence is used to fit the covariates; second, a linear model is used to fit the covariates to the distribution of test scores. We used Markov chain Monte Carlo methods to compute the posterior estimates of the sensitivities and specificities that provide the groundwork for inference concerning the diagnostic procedure's accuracy. We applied the methodology to milk ELISA scores from several dairy-cow herds for the diagnostic testing of paratuberculosis. We found that both milk yield and its interaction with age had significant effects on the disease process whereas only milk yield was significant on the testing procedure.

Effect of BCG immunotherapy on N-nitroso-N-methylurea-induced carcinogenesis of guinea pig colon.

A total of 480 guinea pigs each received twice weekly intrarectal instillations of 1 mg N-nitroso-N-methylurea (NMU) during 14-35 weeks (total dose NMU, 28-70 mg) to induce colon neoplasms. At 24, 28, or 35 weeks after the start of NMU instillation, the distal colon was exposed by a ventral laparotomy and suspected neoplastic lesions were treated by one of four methods: A, intratumoral instillation of an emulsion of killed BCG cell walls attached to oil droplets; B, intratumoral instillation of a control emulsion of killed BCG cell walls in an aqueous phase rather than lipid phase; C, surgical excision of the colon lesion with formation of a ventral diverting colostomy; or D, sham operation (no treatment). All guinea pigs were allowed to recover from surgery and were then observed for a period of 1 year for the study of the effects of these treatments on NMU-induced colon neoplasms. Colon neoplasms were produced in 76% of all sham-operated control guinea pigs, and the frequency of such neoplasms was dependent on the total dose of NMU. Most neoplasms were adenocarcinomas with invasion of the bowel wall but only approximately 5% of them metastasized. Treatment with BCG failed to alter the course of NMU-induced colon carcinogenesis, as determined by the frequency of colon neoplasia, the number, the gross, or microscopic characteristics of colon neoplasms, or the rate of survival.

Correct and incorrect use of child restraints: results from an urban survey in New Zealand.

This study describes the incorrect use of child restraints among car drivers with young children and examines factors that may influence their misuse. A cross-sectional survey was undertaken in supermarket car parks with car drivers travelling with children under the age of 8 years. The main measure was errors in child restraint use. Short interviews were conducted with 1113 drivers with a close inspection of the child restraints used in the vehicles. Only 4% of children were unrestrained but 64% of drivers made at least one error in restraint use. Most respondents thought using a restraint was easy, but 65% of these drivers made at least one error. Child restraints are used, but many are incorrectly fitted and/or have the child incorrectly placed in them. Correct use is a moderately complex task. Restraint systems need to be designed to minimize the opportunity for error and maximize safety.

Exercise induces two types of human luteal dysfunction: confirmation by urinary free progesterone.

We have previously reported that during 2 months of strenuous exercise, untrained young women with documented ovulatory menstrual cycles developed secondary oligoamenorrhea and luteal phase defects. In this study we tested the hypothesis that such abnormalities arise by altered neuroendocrine regulation of menstrual hormone secretion and that weight loss potentiates such effects. We supply a detailed analysis of the 20 cycles, of the total of 53, in which luteal phase abnormalities occurred. During the control month and 2 exercise months, all subjects collected daily overnight urine samples for the determination of LH, FSH, estriol (E3), and free progesterone (P) excretion by RIAs and creatinine by chemical assay. The characteristics of the abnormal luteal phase cycles were determined by comparing the excreted hormone levels and patterns during the control cycles with those of exercise cycles. The area under the curve (AUC) for each hormone was calculated for the follicular and luteal phases of each cycle. Six of the exercise cycles exhibited an inadequate luteal phase. This was characterized by a mean integrated P area of 202.4 (SEM, -61.8) nmol/day.nmol creatinine, compared with 331.7 (SEM, 64.7) during the corresponding control cycles, over a period of 9 or more days after the urinary LH peak to the onset of menses. Fourteen of the exercise cycles exhibited a short luteal phase. This was characterized by a mean integrated P area of 75.9 (30.9) nmol/day.nmol creatinine, compared to 267 (61.7) during the corresponding control cycles, over a span of 8 days or less from the urinary LH peak to the onset of menses. Additional abnormalities occurred only in the short luteal phase cycles. These included an increase in the length and AUC for E3 of the follicular phase and a decrease in the AUC of LH during the luteal phase. We conclude that the initiation of strenuous endurance training in previously ovulating untrained women frequently leads to corpus luteum dysfunction associated with insufficient P secretion and, in the case of short luteal phase cycles, decreased luteal phase length. That exercise may alter the neuroendocrine system is suggested by a delay in the ovulatory LH peak in spite of increased E3 excretion; moreover, less LH is excreted during the luteal phase. The lack of positive feedback to estrogens and decreased LH secretion during the luteal phase could compromise corpus luteum function. In contrast, decreased free P excretion was the sole abnormality noted in menstrual cycles with an inadequate luteal phase.

Reporting the accuracy of biochemical measurements for epidemiologic and nutrition studies.

Procedures for reporting and monitoring the accuracy of biochemical measurements are presented. They are proposed as standard reporting procedures for laboratory assays for epidemiologic and clinical-nutrition studies. The recommended procedures require identification and estimation of all major sources of variability and explanations of laboratory quality control procedures employed. Variance-components techniques are used to model the total variability and calculate a maximum percent error that provides an easily understandable measure of laboratory precision accounting for all sources of variability. This avoids ambiguities encountered when reporting an SD that may taken into account only a few of the potential sources of variability. Other proposed uses of the total-variability model include estimating precision of laboratory methods for various replication schemes and developing effective quality control-checking schemes. These procedures are demonstrated with an example of the analysis of alpha-tocopherol in human plasma by using high-performance liquid chromatography.

Plasma selenium concentration predicts the prevalence of colorectal adenomatous polyps.

The objective of this cross-sectional study was to determine whether plasma selenium concentration predicts the prevalence of adenomatous polyps of the colon and rectum. The source population for the study was 101 patients undergoing sequential colonoscopies at the Veterans Affairs Medical Center, Tucson, AZ. The study population was then limited to the 48 patients (all male) undergoing their initial colonoscopy who did not have a diagnosis of colorectal cancer. For each of these patients, a prediagnostic fasting plasma selenium concentration was determined. The data from this study suggest that fasting plasma selenium concentrations may be an important risk factor for colorectal adenomas. Patients with fasting plasma selenium concentrations below the median (< 128 mcg/liter) were significantly more likely to have one or more adenomatous polyps (prevalence odds ratio 4.2) and more adenomatous polyps (3.5 times) per patient. There was also a suggestion of a more proximal distribution of adenomatous polyps in the patients with a lower level of selenium. These associations were not confounded by age or smoking. The results of this study are consistent with the experimental animal studies, geographic mortality studies, and prospective cohort studies of selenium and colorectal cancer.

Cholesterol-lowering effect of hydroxychloroquine in patients with rheumatic disease: reversal of deleterious effects of steroids on lipids.

PURPOSE: The effects of hydroxychloroquine (HCQ) on serum levels of cholesterol, triglycerides, and high- (HDL) and low-density lipoprotein (LDL) were studied in patients with rheumatoid arthritis or systemic lupus erythematosus. PATIENTS AND METHODS: A total of 155 women were divided into the following treatment groups: Group A: patients taking HCQ and no steroids (n = 58); Group B: patients taking steroids and no HCQ (n = 35); Group C: patients receiving both HCQ and steroids (n = 18); and Group D: patients receiving neither HCQ nor steroids (n = 44). RESULTS: HCQ therapy had a high statistical association with low serum levels of cholesterol (181 mg/dL; p = 0.0006), triglycerides (106 mg/dL; p = 0.0459), and LDL (101 mg/dL; p = 0.0004), irrespective of concomitant steroid administration. The HCQ-treated group (A) had lower cholesterol (181 mg/dL; p = 0.0039) and LDL (101 mg/dL; p = 0.007) levels than those receiving neither HCQ nor steroids (205 mg/dL) and 128 mg/dL) (Group D). No HDL differences were observed. CONCLUSION: The effects of HCQ do not appear to be due to changes in diet or weight, and the drug was well tolerated. Although the mechanism of cholesterol lowering by HCQ is not known, this drug deserves further investigation for its lipid-lowering properties.

Sleep-wave activity of a delta sleep-inducing peptide analog correlates with its penetrance of the blood-brain barrier.

Delta sleep-inducing peptide (DSIP) significantly increases delta wave electrical activity in the brain of rats after intraperitoneal (i.p.) injection. Rats (n = 10) were peripherally injected with DSIP and [D-Ala4]DSIP-NH2 during the dark portion of a 12-h light/dark cycle prior to recording of epidural encephalographic (EEG) wave forms. Administration of [D-Ala4]DSIP-NH2, an analog that enters the brain after peripheral administration more readily than the parent DSIP molecule, resulted in significantly more delta waves than DSIP together with a highly significant amount of theta activity. DSIP was found to significantly increase EEG output in the delta range when compared with controls. In addition, the DSIP analog significantly decreased locomotor activity, whereas DSIP itself was without effect. These findings strongly support the controversial concepts that peripherally injected peptides can reach the brain and that DSIP compounds can increase sleep activity.

The effect of MSH/ACTH 4-10 on delayed response performance and post-test locomotor activity in rats.

Delayed response performance was measured in male, Long-Evans rats 1 hr after IP administration of various doses of MSH/ACTH 4-10 or control in a Hunter delayed reaction apparatus. Additional treatments consisting of naloxone 500 micrograms/kg (IP) and naloxone 500 micrograms/kg in conjunction with MSH/ACTH 4-10 95 micrograms/kg were also administered. Directly after delayed response performance was assessed, gross locomotor activity was determined. MSH/ACTH 4-10, at a dose of 95 micrograms/kg, significantly enhanced retention of a visual stimulus, while MSH/ACTH 4-10, at doses of 195 and 285 micrograms/kg, significantly impaired delayed response performance. Naloxone treatment resulted in significantly impaired delayed response performance when compared to control. However, naloxone plus MSH/ACTH 4-10 treatment failed to produce a significant difference from control in the delayed response performance paradigm. In post-test locomotor activity determination, an apparent dose-response existed for MSH/ACTH 4-10 with the two highest doses (190 and 285 micrograms/kg) resulting in significantly increased locomotor activity. The observed delayed response performance data support theories implicating MSH/ACTH peptides in attentional processes involving visual stimuli. The fact that large doses of MSH/ACTH 4-10 disrupt delayed response performance while increasing post-test activity suggest that an optimum level of effect caused by the MSH/ACTH peptide exists in this paradigm.

Immediate effects of digit amputation on SI cortex in the raccoon: unmasking of inhibitory fields.

Immediately after removal of one digit, inhibitory receptive fields were revealed in the affected part of somatosensory cortex. These were usually seen as 'off' responses if only a short, tapping stimulus is used. Over the course of several weeks, these inhibitory responses disappear and are replaced by excitatory responses. These changes are seen with both alpha-chloralose and barbiturate anesthesia.

Unexpected reorganization of somatosensory cortex in a raccoon with extensive forelimb loss.

Electrophysiological recordings were made from primary somatosensory cortex in a raccoon that had suffered a traumatic amputation of the forearm some time prior to its capture. Neurons in the affected forepaw region of sensory cortex were not silent but responded to cutaneous or neuroma activation of the remaining forearm stump. In addition, cells at many sites were responsive to tactile stimulation of the glabrous skin of the hindpaw ipsilateral to the damage. This indicates that the cortical plasticity following peripheral nerve damage can occur over much larger regions of cortex than was previously thought. An unmasking of silent thalamocortical terminals is not likely to be the mechanism underlying this plasticity in the raccoon.

Effects of short-term strenuous endurance exercise upon corpus luteum function.

PURPOSE: The present study tested whether short-term, abruptly initiated training can cause corpus luteum dysfunction when exercise is limited to either the follicular or luteal phase of the cycle. METHODS: Reproductive hormone excretion and menstrual characteristics were studied in sedentary women who exercised only during the follicular (N = 5) or the luteal (N = 4) phase. Six women served as controls, three of whom exercised at a low volume and three who remained sedentary. Weekly progressive increments in exercise volume continued until either ovulation (follicular group) or menses (luteal group) occurred. Physical activity and nutrient intake were closely monitored with the intent to maintain body weight. RESULTS: No luteal phase disturbances occurred in any of the control subjects, whereas 40% of follicular and 50% of luteal exercisers experienced luteal defects. The proportion of menstrual cycles disrupted was not different between luteal and follicular exercisers (50% vs 30%, respectively) but was significantly greater than the proportion of cycles disrupted in control subjects (P < 0.05). CONCLUSIONS: These results suggest that exposure to abrupt onset of training can alter luteal function, regardless of the menstrual cycle phase in which exercise occurs. This study also demonstrates that a relatively low volume of exercise suffices to induce mild disturbances in luteal function.

Strenuous exercise with caloric restriction: effect on luteinizing hormone secretion.

To test whether strenuous exercise with and without caloric restriction alters LH secretion, and whether these changes are apparent in the immediate post-exercise period, LH pulse parameters were studied in four moderately trained eumenorrheic women over three successive menstrual cycles. Blood samples were obtained 5 h before and 5 h after 90 min of running at 74% VO2max. Each test was preceded by a 7-d treatment of controlled diet and exercise (74% VO2max). During CONTROL, subjects were eucaloric on days 1-7, and performed no exercise on days 5-7. During STTI (short-term training increase), subjects were eucaloric and completed 90 min runs on days 5-7. During DIET/STTI, subjects consumed 60% of the calories necessary to maintain weight on days 1-7, and exercised as in STTI. A significant decrease in overall (0700-1830 h) LH pulse frequency during DIET/STTI compared with CONTROL and STTI treatments was observed. No changes were found in mean serum LH levels or peak amplitude. These results suggest that high-volume training combined with caloric restriction may predispose one to exercise-induced changes in LH pulse frequency, while adequate caloric intake may prevent these changes.

Effect of high doses of naloxone on shuttle avoidance acquisition in rats.

Administration of high doses of naloxone intraperitoneally (2.5-10.0 mg/kg) resulted in a dose-related impairment of avoidance response acquisition in a shuttle avoidance paradigm in rats. Naloxone in this dose range produced a significant decrease in the number of intertrial responses but did not result in a significant dose-response. Escape latencies were not affected by naloxone administration at any dose tested. The effect of naloxone on activity and nociception are implicated as possible causes of the observed behavior. The results are discussed as behavioral evidence supporting theories postulating multiple opiate receptors.

The detection of peaks in luteinizing hormone secretion.

Fluctations in luteinizing hormone are believed to consist of irregularly spaced sharp increases separated by periods of exponential decay. A simple method is presented for analysing such fluctuations when the data consist of uniformly sampled observations of hormone. Specific allowance for the exponential decay in the absence of pulses is made via a time series model before assessing the number and extent of pulses. All calculations are done using MINITAB regression programs. The results have been compared with those obtained by three established models and are in general agreement.