Isolation and identification of a peptide from rat brain which inhibits [3H]TCP binding

1. A stereospecific radioreceptor binding assay for the phencyclidine analogue [3H]TCP was utilized to screen for inhibitors of binding in extracts of rat brain. 2. Extracts were prepared from rat cortex and hippocampus by methods employing aqueous acid or acidified methanol. Samples were fractionated by reversed phase-HPLC (RP-HPLC) and tested for activity in the radioreceptor assay. Three zones of activity were detected. The most active fraction was further purified by high performance-size exclusion chromatography. 3. Size exclusion chromatography revealed two zones of activity, corresponding to mol. wts of 4000-8000 Da and 1000-2000 Da. Final purification of the lower molecular weight material was achieved by RP-HPLC. 4. Two well-separated peaks were shown to be homogeneous. Their amino acid sequences were determined by automated Edman degradation and data base searching identified these two peaks as the undecapeptide Substance P and its oxidized counterpart (Substance P sulfoxide). 5. Comparative HPLC of synthetic Substance P, or its sulfoxide, as well as spectral analysis confirmed the identity of the isolated peptides. 6. Synthetic Substance P inhibits specific [3H]TCP binding in the radioreceptor assay.

Validation of weekly-dose cisplatin combined with radiation therapy in locally advanced head and neck cancer

6076

Background: Impressive outcomes have been achieved using multiagent neoadjuvant and concomitant chemotherapy combined with radiation in definitive treatment of head and neck cancer; these are associated with significant toxicities. The purpose of this study was to determine the efficacy and toxicities of single-agent weekly (CDDP) during curative-intent radiation therapy. Methods: 36 patients with AJCC Stage II (3%), Stage III (14%), Stage IV (83%) squamous cell carcinoma of the larynx, hypopharynx, oropharynx and oral cavity treated from 6/2000 to 11/2003 were retrospectively reviewed. Subjects received 72 Gy irradiation given either by hyperfractionation or IMRT technique with CDDP 30 mg/m2/wk throughout the radiation course. Cisplatin was held for Grade III/IV toxicities. The endpoints were best response, percentage of Grade III/IV toxicities, disease-free survival (DFS), overall survival (OS). Results: The median number of cycles of CDDP administered was 6. Grade III/IV toxicities: 11% of patients had anemia, 6% thrombocytopenia, 33% leukopenia, 0% renal failure, and 25% developed Grade III/IV mucositis; 1 patient (3%) died due to complications directly related to therapy. Responses to therapy included 72% CR, 17% PR, and 5% SD. Median follow-up for all patients was 19 months (34.5 months for living patients), DFS at 3 years (yrs.) was 59%, and OS at 3 yrs, was 40%. Nine patients died of disease up to 2.6 (median, 0.7) yrs. after treatment, while 11 died of intercurrent diseases up to 5.1 (median, 1.8) yrs. later. Fifteen are alive (2 with recurrence) at median 2.7 yrs. after treatment. Conclusion: Concomitant weekly CDDP with full-course radiation is feasible, tolerable, highly active, and comparable to more complex, costly and toxic regimens. Intercurrent disease was a significant contributor to mortality in our population. Our regimen is an attractive alternative to sequential chemoradiotherapy programs.

No significant financial relationships to disclose.

Gallbladder function in the human female: effect of the ovulatory cycle, pregnancy, and contraceptive steroids

We have previously shown that in pregnancy fasting gallbladder volume is increased and emptying after a small volume liquid meal is incomplete. In this study we measured gallbladder volume throughout day and night in healthy women ingesting regular meals. Pregnant women, postpartum women, contraceptive-steroid users, and controls in both phases of the ovulatory cycle were studied. After an overnight fast gallbladder volume was measured by realtime ultrasonography in the fasting state and every 5-10 min for 90 min after breakfast. Residual volume was the lowest volume achieved and the rate constant of gallbladder emptying was calculated from the ln/linear regression of gallbladder volume vs. time. Gallbladder volume was also measured hourly from 11 AM to midnight while subjects ate regular, standard meals, allowing the determination of an average hourly volume. There was no effect of phase of the ovulatory cycle on any measure of gallbladder function. Fasting, residual, and average hourly volume were increased in all trimesters of pregnancy, but tended to return to normal in the postpartum period. Women taking contraceptive steroids had an increased fasting volume. Two distinct rates of emptying after breakfast, an early and a late one, were identified. The early rate was the same in all groups. Pregnant women had a slower late rate of emptying, but women taking contraceptive steroids had emptying rates similar to controls. Retention of bile in the gallbladder may be one reason for the increased risk of cholesterol cholelithiasis in pregnant women and in those taking contraceptive steroids.

Rapid metabolic phenotypes for acetyltransferase and cytochrome P4501A2 and putative exposure to food-borne heterocyclic amines increase the risk for colorectal cancer or polyps

The metabolic activation of food-borne heterocyclic amines to colon carcinogens in humans is hypothesized to occur via N-oxidation followed by O-acetylation to form the N-acetoxy arylamine that binds to DNA to give carcinogen-DNA adducts. These steps are catalyzed by hepatic cytochrome P4501A2 (CYP1A2) and acetyltransferase-2 (NAT-2), respectively, which are known to be polymorphic in humans. On the basis of this proposed metabolic activation pathway, patients at greatest risk to develop colorectal cancer or nonfamilial polyps should be those who possess both the rapid NAT-2 and rapid CYP1A2 phenotypes and are exposed to high dietary levels of carcinogenic heterocyclic amines. Using a method that involves caffeine administration and high pressure liquid chromatographic analysis of urinary metabolites, we have determined the CYP1A2 and NAT-2 phenotypes of 205 controls and 75 cancer/polyp cases. Exposure information was obtained using a dietary and health habits questionnaire. Both the rapid CYP1A2 and rapid NAT2 phenotypes were each slightly more prevalent in cases versus controls (57% and 52% versus 41% and 45%, respectively). However, the combined rapid CYP1A2-rapid NAT-2 phenotype was found in 35% of cases and only 16% of the controls, giving an odds ratio of 2.79 (P = 0.002). Univariate analysis of the questionnaire indicated that age, rapid-rapid phenotype, and consumption of well done red meat were associated with increased risk of colorectal neoplasia. Furthermore, a logistic regression model that included age (as a continuous variable), consumption of well done red meat, and rapid-rapid phenotype as independent covariates gave odds ratios of 1.08, 2.08, and 2.91, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Nuclear magnetic resonance probe head design for precision strain control

We present the design and construction of an NMR probe to investigate single crystals under strain at cryogenic temperatures. The probe head incorporates a piezoelectric-based apparatus from Razorbill Instruments that enables both compressive and tensile strain tuning up to strain values on the order of 0.3% with a precision of 0.001%.   ⁷⁵As NMR in BaFe₂As₂ reveals large changes to the electric field gradient and indicates that the strain is homogeneous to within 16% over the volume of the NMR coil.

Abstract P5-11-04: Therapy-induced priming of natural killer cells predicts patient-specific tumor rejection in multiple breast cancer indications

Background: Predicting patient-specific clinical response to anticancer therapy is the holy grail of treatment-selection. It is now clear that response or resistance to therapy depends on the heterogeneous tumor microenvironment, which is comprised of malignant cells, normal stroma, soluble ligands, and tumor-immune contexture; attributes that are unique to each individual patient. This is particularly true for emerging anticancer drugs, such as immune checkpoint inhibitors, which recalibrate the body's own immune defense largely by modulating exhaustion of cytotoxic lymphocytes including T cells and natural killer (NK) cells. However, clinical response to therapy varies enormously. There is a critical gap in our understanding for the mechanisms that drive response or resistance to conventional drugs and immunotherapies at the individual patient level.

Methods: Here, we used a fully patient-autologous, clinically-validated ex-vivo tumor model that recreates and preserves the native, patient tumor microenvironment (CANscriptTM), which incorporates an algorithm-driven method to predict clinical response to therapy (M-Score). Utilizing tissue from patients diagnosed with luminal, HER2 positive, and triple-negative (ER- PR- HER2-) breast cancers (N=10), we studied phenotypic alterations to the tumor-immune contexture under pressure of conventional standard-of-care regimens and immunotherapies including immune-checkpoint inhibitors, ex-vivo. To do this, we used a comprehensive panel of immunological assays to evaluate changes in cytotoxic lymphocytes by flow cytometry and multiplex immunohistochemistry (i.e. CD56, MHC class 1A/B, NKG2D/C, CD8, CD3, PD-1, CTLA-4, TIM-3, LAG-3, 4-1BB, granzyme A/B). In addition, we used multiplex cytokine analysis to study the soluble components of the tumor microenvironment.

Results: We identified that tumor response, predicted by M-Score, correlates to increased infiltration of NK cells, which associated a pro-inflammatory cytokine signature from the tumor microenvironment. Interestingly, these evidences were concordant with induction of the tumor-expressing biomarker MICA/B, which is known to attract and recruit active NK cells. Furthermore, we determined that therapy-induced expression of protein biomarkers associated with NK cell exhaustion inversely correlated to the expression of cytotoxic granzyme B in the tumor microenvironment.

Conclusions: Taken together, these data demonstrate an integral role that NK cells contribute to the antitumor effect of therapy including conventional and immuno-modulatory drugs. It further demonstrates how a novel ex-vivo platform can be harnessed to study the mechanisms of response and resistance, which couldn't otherwise be known in a drug naïve state. Such an advance in our preclinical methods to study anticancer drugs at the individual patient level can help guide treatment decisions for clinicians while simultaneously functioning as a platform to study clinical efficacy of novel and emerging agents.

Citation Format: Smalley M, Shanthappa BU, Gertje H, Lawson M, Ulaganathan B, Thayakumar A, Maciejko L, Radhakrishnan P, Biswas M, Thiyagarajan S, Majumder B, Gopinath KS, K GB, Goldman A. Therapy-induced priming of natural killer cells predicts patient-specific tumor rejection in multiple breast cancer indications [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-11-04.

An epidemic without illness. Using dna markers to model infection

PURPOSE: Combining molecular biology with infection control interventions can increase compliance and allow objective measurement of effectiveness. We developed a group of PCR detectable non-infectious DNA markers that can be used to model infection and provide immediate feedback on hygiene practices in institutional settings. In previous studies, we illustrated that the markers were spread in the environment in the same manner as infectious particles.METHODS: We are conducting a prospective study in 10 child care centers in order to 1) confirm that the DNA markers are valid surrogates for bacteria and viruses; 2) identify specific foci of contamination and modes of transmission; 3) illustrate the effectiveness of infection control programs utilizing the DNA markers. Centers are randomized to receive an interactive educational infection control intervention or a standard immunization intervention. The DNA markers are introduced into the center and the rate of dispersion of the DNA markers is compared with directly observed changes in hygiene behavior among the staff.RESULTS: Initial results indicate that the markers can be removed mechanically by hand washing and that common over-the-counter cleaners are effective in inactivating the markers. Toys, countertops and doorknobs appear to be more important as infectious reservoirs than brief casual contact. Data from the prospective study will be available prior to September, 2000.CONCLUSIONS: This novel approach utilizing an objective measurement will be used to identify the interaction between behavior and environmental reservoirs of infection and drive future strategies for infection control.