Pre-surgical trial of the AKT inhibitor MK-2206 in patients with operable invasive breast cancer: a New York Cancer Consortium trial

INTRODUCTION

The PI3K/AKT/mTOR pathway is an oncogenic driver in breast cancer (BC). In this multi-center, pre-surgical study, we evaluated the tissue effects of the AKT inhibitor MK-2206 in women with stage I-III BC.

MATERIALS AND METHODS

Two doses of weekly oral MK2206 were administered at days - 9 and - 2 before surgery. The primary endpoint was reduction of pAkt^Ser473 in breast tumor tissue from diagnostic biopsy to surgery. Secondary endpoints included changes in PI3K/AKT pathway tumor markers, tumor proliferation (ki-67), insulin growth factor pathway blood markers, pharmacokinetics (PK), genomics, and MK-2206 tolerability. Paired t tests were used to compare biomarker changes in pre- and post-MK-2206, and two-sample t tests to compare with prospectively accrued untreated controls.

RESULTS

Despite dose reductions, the trial was discontinued after 12 patients due to grade III rash, mucositis, and pruritus. While there was a trend to reduction in pAKT after MK-2206 (p = 0.06), there was no significant change compared to controls (n = 5, p = 0.65). After MK-2206, no significant changes in ki-67, pS6, PTEN, or stathmin were observed. There was no significant association between dose level and PK (p = 0.11). Compared to controls, MK-2206 significantly increased serum glucose (p = 0.02), insulin (p < 0.01), C-peptide (p < 0.01), and a trend in IGFBP-3 (p = 0.06).

CONCLUSION

While a trend to pAKT reduction after MK-2206 was observed, there was no significant change compared to controls. However, the accrued population was limited, due to toxicity being greater than expected. Pre-surgical trials can identify in vivo activity in the early drug development, but side effects must be considered in this healthy population.

Proteomic modulation in breast tumors after metformin exposure: results from a "window of opportunity" trial

PURPOSE

Reverse Phase Protein Array (RPPA) is a high-throughput antibody-based technique to assess cellular protein activity. The goal of this study was to assess protein marker changes by RPPA in tumor tissue from a pre-surgical metformin trial in women with operable breast cancer (BC).

METHODS

In an open-label trial, metformin 1500-mg PO daily was administered prior to resection in 35 non-diabetic patients with stage 0-III BC, body mass index ≥25 kg/m². For RPPA, formalin-fixed paraffin-embedded (FFPE) samples were probed with 160 antibodies. Paired and two-sample t-tests were performed (p ≤ 0.05). Multiple comparisons were adjusted for by fixing the false discovery rate at 25 %. We evaluated whether pre- and post-metformin changes of select markers by RPPA were identified by immunohistochemistry (IHC) in these samples. We also assessed for these changes by western blot in metformin-treated BC cell lines.

RESULTS

After adjusting for multiple comparisons in the 32 tumors from metformin-treated patients vs. 34 untreated historical controls, 11 proteins were significantly different between cases vs.

CONTROLS

increases in Raptor, C-Raf, Cyclin B1, Cyclin D1, TRFC, and Syk; and reductions in pMAPK^pT202,Y204, JNK^pT183,pT185, Bad^pS112, PKC.alpha^pS657, and Src^pY416. Cyclin D1 change after metformin by IHC was not observed. In cell lines, reductions in JNK^pT183 and Bad^pS112 were seen, with no change in Cyclin D1 or Raptor.

CONCLUSIONS

These results suggest that metformin modulates apoptosis/cell cycle, cell signaling, and invasion/motility. These findings should be assessed in larger metformin trials. If confirmed, associations between these changes and BC clinical outcome should be evaluated. CLINICALTRIALS.

GOV IDENTIFIER

NCT00930579.

Abstract P3-13-03: Multicenter clinical trial of percutaneous laser ablation for early stage primary breast cancer. Results of 49 cases with radiographic and pathological correlation

Introduction: Percutaneous laser ablation of early stage primary breast cancer remains investigational. A multicenter, international clinical trial (NCT01478438) was completed to determine feasibility of this technique.

Methods: Patients with a single focus of biopsy proven infiltrating ductal carcinoma measuring 20 mm or less by pre-ablation MRI were treated by image-guided percutaneous laser ablation. A laser diode source (805 nominal nanometer wavelength) was used to perform the thermal ablation. Thermal sensors placed at the periphery of the tumor measured achievement of predefined temperature levels, indicating successful ablation. The patients were evaluated by post-ablation mammogram, ultrasound and MRI at 4 weeks post-ablation, after which they underwent surgical excision. Pathology specimens were evaluated by hematoxylin & eosin, CK 8/18, Ki-67 and estrogen receptor staining.

Results: Forty-nine of the 61 enrolled patients (ages 42-77, mean age 64 years) undergoing percutaneous laser ablation have finished protocol analysis and are reported in this series. Ablation was considered complete by the treating physician in all cases. The mean tumor size was 11.3 mm. The mean laser time was 15.7 minutes. There were no serious adverse events. Seven patients (14%) reported mild adverse events (pain, blisters, lump). Post-ablation cell viability was determined by MRI and by changes in CK 8/18, Ki67 and estrogen receptor staining. A post-ablation discordance between MRI and pathology was found in evaluation of 4 patients (8%). Three patients (6%) were considered "false negative" with a post-ablation residual tumor burden of less than 2mm which was not detected by MRI. One patient (2%) had a complete pathologic ablation but positive MRI ("false positive"). One patient (2%) had adjacent residual DCIS, visible in retrospect on the pre-ablation MRI and was considered a screening failure. Eight patients (16%) were found to have residual invasive cancer by both post-ablation MRI and pathologic analysis. Complete ablation was confirmed in 36 patients (73%) when evaluated by both post-ablation MRI and pathologic analysis.

Conclusion: Percutaneous laser ablation holds promise as an alternative to lumpectomy in the treatment of early stage breast cancer. There is a strong correlation (92%) between findings on post-ablation MRI and changes in CK 8/18, Ki67 and estrogen receptor staining in this series. Additional trials are necessary to determine the long-term curative potential of this technique.

Citation Format: Schwartzberg BS, Abdelatif OMA, Lewin JM, Bernard JM, Brehm JL, Bu-Ali HM, Cawthorn SJ, Chen-Seeto M, Feldman SM, Govindarajulu S, Jones LI, Juette A, Kavia S, Maganini RO, Pain SJ, Shere MH, Shriver CD, Smith SG, Valencia A, Whitacre EB, Whitney R. Multicenter clinical trial of percutaneous laser ablation for early stage primary breast cancer. Results of 49 cases with radiographic and pathological correlation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-13-03.

Abstract OT2-6-06: Pre-surgical “window of opportunity” trial of metformin and atorvastatin in newly diagnosed operable breast cancer

Background: Breast cancer requires energy homeostasis shifts with enhanced anabolism to enable rapid growth and continued proliferation. The main energy regulatory system is the AMP-activated kinase (AMPK) pathway triggered by changes in the AMP/ATP ratio. AMPK pathway closely interacts with the PI3K/AKT signaling pathway, with both pathways affecting downstream function of the master regulator mTOR. “Window of opportunity” studies with metformin alone, an AMPK inhibitor, have resulted in mixed results in reducing tumor proliferation in women with early-stage operable breast cancer. Reduction in tumor proliferation has been demonstrated with statins alone (i.e. HMG CoA reductase inhibitors) in pre-surgical trials. Dual therapy with both metformin and atorvastatin demonstrate synergistic activity in preclinical studies in cancer cell lines, showing enhanced anti-proliferative effect. The purpose of this study is to determine the effects of dual therapy with metformin and atorvastatin in women with newly diagnosed BC between breast biopsy and surgery.

Trial Design: Patients (n = 40) will receive metformin 1500mg (500 mg am/1000 mg pm) and atorvastatin 80mg pm, for 2-4 weeks following a diagnostic biopsy and prior to surgery (goal: at least 2 weeks). The main eligibility criteria for this open-label, single-institution, pre-surgical trial include operable stage 0-III BC. Patients must have at least 1 cm of tumor based on palpation or imaging to ensure sufficient pre-treatment tissue. Patients not considered for neoadjuvant chemotherapy are eligible. Specific Aims: Our hypothesis is that pre-surgical metformin plus atorvastatin will result in a significant decrease in the tumor proliferation marker Ki-67. Ki-67 will be log-transformed ln(ki-67), per international guidelines. Secondary objectives include evaluation of functional proteomic changes, such as AMPK/mTOR pathway signaling and apoptosis, by reverse phase protein array (RPPA), as well as assessment of changes in serum insulin, lipids, and markers of the insulin growth factor pathway.

Statistical Methods: Paired t-tests will be calculated to assess modulations in ln(ki-67) before and after treatment. Compared to historical control, we will achieve 80% power with 40 patients, anticipating a -0.523 reduction of ln(ki-67) and standard deviation of 1.15 before and after metformin plus statin (significance level, p = 0.05). We will also be comparing changes in ln(ki-67) in the treated patients to historical controls matched by age, stage, and BMI, using a two-sample t-test at level 0.05. Frequency distributions and summary descriptive statistics will be calculated for all other biomarkers in the two groups. Correlations between all biomarkers and changes in Ki-67 proliferation marker will be analyzed in exploratory fashion. We will also explore differences in modulation of tumor proliferation and functional proteomics in grade III tumors as compared to other tumors. We anticipate accrual 2-3 patient/month, completing the trial within 18 months. Contact information: kk2693@columbia.edu.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-06.

Abstract P2-18-07: Nipple sparing mastectomy-infectious complication risk. A preliminary assessment of the American Society of Breast Surgeons nipple sparing mastectomy registry

Objectives: The American Society of Breast Surgeons (ASBS) Nipple Sparing Mastectomy Registry (NSMR) is a prospective, IRB approved, non-randomized, multi-institutional registry assessing surgical techniques, utilized metrics, oncologic outcome, and aesthetic outcome of nipple sparing mastectomies. The registry has been open for enrollment for 26 months. The target accrual is 1000 individuals. This abstract specifically analyzes rates of post-operative infection in NSMs.

Methods: Fifty two investigators from 41 institutions are participating in the ASBS NSMR. A total of 373 patients underwent 631 mastectomies, with indications of prophylaxis (365), cancer (248), and unknown (18). We assessed a sub group of 449 mastectomies, with indications of prophylaxis (253) and cancer (196) that had all data sets completed. We assessed infection rates(characterized as needing oral or iv antibiotics with or without removal of implant/expander and/or debridement) in the entire group as well as by indication (cancer vs. prophylaxis). Factors such as smoking history, previous radiation therapy, previous surgery, incision type, reconstruction technique, and flap dissection technique were analyzed.

Results: In a subgroup of 449 mastectomies (253 prophylactic and 196 cancer):

Post operative infections were reported in 22 (4.9%) of patients: 7 (3.6%) of mastectomies with an indication of cancer and 15 (5.9%) of prophylactic mastectomies (p-value 0.3140). Infections were characterized as: treatment with oral antibiotics alone, treatment with i.v. antibiotics alone, iv antibiotics with washout or debridement, or antibiotics and implant/ tissue expander removal. No correlation was found in smoking history (p-value 1.000), previous breast surgery (p-value 0.1277) or previous radiation (p-value 0.6024). No correlation was found in incision utilized, reconstruction technique, or method of flap dissection either.

Conclusion:

The rate of postoperative infections in nipple sparing mastectomies is comparable if not lower than non-nipple sparing mastectomies. No statistically significant difference in infection rate was found between mastectomies completed for prophylaxis or cancer. No correlation was found between factors such as smoking history, history of radiation therapy, prior breast surgery, incision utilized, reconstruction technique, or method of flap dissection. Improved aesthetics with a nipple sparing approach (technically more demanding and typically through a smaller incision) does not come at the cost of a higher rate of infectious complications.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-18-07.

Abstract P4-15-03: Proteomic modulation in breast tumors after metformin use: Results from a “window of opportunity” trial

Background: Laboratory and population studies demonstrate that metformin offers a beneficial breast cancer (BC) effect through reduction of serum insulin levels and changes in cellular protein synthesis and growth, such as AMPK pathway signaling. In a pre-surgical metformin trial of overweight/obese, multi-ethnic BC patients, we reported no difference in tumor proliferation, as measured by ki-67. However, reductions in other biomarkers were observed, including reduction in body mass index (BMI), serum cholesterol, serum insulin, and leptin. Reverse Phase Protein Array (RPPA) is a high-throughput antibody-based technique to assess cellular protein activity in signaling networks. The goal of this study was to assess changes in functional proteomics through RPPA in patients treated in a pre-surgical metformin trial.

Methods: Metformin 1500mg PO daily (500mg am/1000 mg pm) was administered for 2-4 weeks prior to resection in 35 patients with stage 0-III operable BC, BMI ≥ 25 kg/m2, and no history of diabetes. Protein was extracted from pre- and post-metformin paraffin-embedded tumor tissue, denatured by sodium dodecyl sulfate, and printed on nitrocellulose-coated slides. Samples were probed with 160 antibodies. Evaluated antibodies associated with various cellular activities, including PI3K/AKT signaling, HSP90 clients, Src/STAT activity, and apoptosis. We analyzed changes in RPPA parameters in tumor tissue of study patients with those of untreated historical controls, matched by age, BMI, and tumor characteristics. Paired t-test was used to calculate within-group changes in RPPA, and two-sample t-tests were used to compare between-group changes in cases and controls (significance: p ≤ 0.05). Multiple comparisons were adjusted for by fixing the false discovery rate (FDR) at 25%.

Results: Of the 35 metformin-treated patients, 32 were evaluable. The majority were Hispanic (80%). Metformin was administered for a median of 23 days (range: 8-64). Of the invasive BCs (n = 21/35), 80% of patients had HR+/HER2- BC. The 33 historical controls were well-matched. For RPPA, the mean total formalin-fixed paraffin embedded protein concentration was 38.9 ug (SD: 3.3). Of the 160 antibodies, 67 antibodies significantly changed after metformin use in the treated group, including reduction in pAKTS473, pAKTT308, and MTOR (unadjusted). Nineteen antibodies were identified as having between group differences in change from baseline: increase in BadpS112, C-RAF, Claudin-7, Cyclin B1, Cyclin D1, EGFR, HER3 pY1298, Lck, PKC-alphapS657, RAD50, Raptor, Syk, and TRFC; reduction in 14-3-3 epsilon, FOXO3a, JNKpT183, MAPKpT202, MEK1pS217, and SrcpY416. Adjusting for multiple comparisons, the following remain statistically significantly different between cases vs. controls: increase in BadpS112, C-RAF, Cyclin D1, and Raptor; and reduction in JNKpT183. Further assessment of RPPA modulation is ongoing, including changes grouped by signaling pathway and activity, as well as validation by immunohistochemistry.

Conclusions: Compared to controls, metformin use associates with changes in apoptosis, cell signaling, C-RAF, and Raptor. These results should be further validated in larger metformin intervention trials to better define populations who may benefit from this therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-15-03.

Abstract PD03-03: Pre-surgical Trial of Metformin in Overweight and Obese, Multi-ethnic Patients with Newly Diagnosed Breast Cancer

Background: Overweight or obese women with breast cancer (BC) have a higher risk of distant recurrence and death compared to normal weight women. There is increasing evidence that insulin significantly mediates these adverse clinical outcomes. Laboratory and population studies demonstrate that metformin offers a protective BC effect through reduction of serum insulin levels and direct modulation of cellular protein synthesis and growth through AMPK pathway signaling. Our aim is to assess the biologic impact of metformin on blood- and tumor-based markers on insulin, IGF and AMPK/mTOR pathway signaling, and/or proliferation in operable BC patients with a body mass index (BMI) ≥ 25 kg/m2.

Methods: The study was an open-label pre-surgical trial with metformin 1500 mg PO per day (500 mg am/1000 mg pm) for 2–4 weeks prior to surgical resection in 35 overweight or obese patients with invasive BC (n = 25) or ductal carcinoma in situ (n = 10) and no history of diabetes. The primary endpoint was to assess a reduction in tumor proliferation. We have 80% power to detect a 30% decrease in Ki-67 in invasive BCs from baseline to post-metformin values (two-sample t-test, 0.05). Secondary endpoints include changes in BMI and insulin resistance markers, such as fasting serum insulin, lipid panel, glucose, leptin, and adiponectin. Tumor markers will be compared to untreated historical controls matched by age, BMI, and tumor characteristics.

Results: Between Oct 2009 to Aug 2011, we screened 116 patients, enrolling 35 with newly diagnosed BC: 18/34 overweight (27.6: 25.1–29.7) and 16/34 obese (35.9: 30.5–46.4). Hispanic women made up 80% of the population (28/35). The median metformin duration was 22 days (1–64). All took metformin until the evening prior to surgery, except 2 (1 withdrew and 1 stopped early after surgery delay). More than half had a prior diagnosis of hypertension and a third had hypercholesterolemia. In the invasive BC cohort (n = 25), 19/25 (76%) were HR+/HER2−. The most common grade I-II included self-limiting diarrhea, flatulence, abdominal pain, fatigue, and anorexia. Grade III events included abdominal pain (n = 1) and diarrhea (n = 3). The change in blood markers are described in the table. Tumor Ki-67 (immunohistochemistry) and pathway signaling analyses (reverse protein microarray) are ongoing.

Abstract P1-11-15: Improving Patient Accrual to “Window of Opportunity” Trials

Background: A challenge in evaluating new targeted investigational agents is procuring tumor tissue to measure the direct biologic effect on tumor cells. Pre-surgical studies, i.e. “window of opportunity” trials, in women with newly diagnosed, operable breast cancer (BC) provide an opportunity to assess the biologic impact of new agents on human tissue. The study drug is taken between the time of diagnostic biopsy and definitive surgical resection (approx 2-4 weeks). Pre-and post-treatment blood and tumor tissue are collected to evaluate for biomarker modulation. While these trials are appealing, conducting them can be difficult. We present the evolution of a multidisciplinary pre-surgical program, focusing on “lessons learned” with regard to patient accrual, improving tissue acquisition, and maintaining quality control.

Material and Methods: We have completed 2 pre-surgical studies (anastrazole, polyphenon E), with 1ongoing (metformin).The Recruitment Core is a shared NCI cancer center resource that identifies and screens participants for active studies. Charts of women with newly diagnosed BC are screened for eligibility. If a patient is deemed appropriate by the surgeon, she is introduced to the recruiters, and the medical oncology research team evaluates the patient that day. Once consented, the patient undergoes blood collection and clinical evaluation prior to study drug usage (same day or next). The research staff contacts the patient by phone weekly to assess toxicities and ensure medication adherence. The patient presents the day of or prior to surgery for blood work and clinical examination. The post-treatment surgical resection tissue (paraffin embedded and frozen) is collected for biomarker analysis.

Results: We have enrolled 52 patients to 3 trials: 10 at a rate of 2.5/month, 25 at 1.5/month, and 17 at 2.5/month. Stress from the diagnosis and fear of toxicity are the main reasons for not enrolling. Another barrier to enrollment is strict eligibility criteria; for example,28/66 (43%) patients were ineligible due to a required BMI &gt; 25 without known diabetes. The majority of patients are not overwhelmed by the trial discussion and appreciate the oncology consultation prior to surgery. Weekly multidisciplinary meetings have resulted in improvements to study accrual and data quality. Over time, the requirements for tumor acquisition have been standardized to decrease variability in biomarker analysis. To ensure sufficient quantity of pre-study tumor tissue, patients undergo up to 4 core biopsies at diagnosis (tumor&gt;1cm). To limit the warm ischemia period and ensure biomarker reproducibility, core biopsies are fixed within 20 minutes. At resection, the surgical specimen is placed in ice-cold formalin within 30 minutes of devascularization. Excisions are fixed for 6-48 hours prior to processing.

Conclusion: Studying a new agent pre-surgically is an effective tool in assessing a drug's impact on tumor biology and predictive biomarkers. In order for pre-surgical studies to be successful, a close collaboration between radiology, surgery, medical oncology and pathology must be established and continually reassessed. We plan to utilize this multidisciplinary approach to successfully complete future pre-surgical studies, including a multicenter trial with a novel AKT inhibitor.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-11-15.

Limitation in gamma probe localization of the sentinel node in breast cancer patients with large excisional biopsy

BACKGROUND

Radiolocalization and selective biopsy of the sentinel node to correctly predict the status of remaining lymph nodes may provide an alternative to axillary dissection in selected breast cancer patients with clinically negative lymph nodes.

STUDY DESIGN

In a nonrandomized, multicenter clinical trial, gamma probe localization for lymphatic mapping and sentinel node biopsy along with axillary dissection was performed on 75 patients with invasive breast cancer and clinically negative lymph nodes. The accuracy of the sentinel node biopsy to correctly predict the status of the remaining axillary lymph nodes was established through standard pathologic investigation.

RESULTS

A sentinel node was identified in 70 of 75 patients with a technical success rate of 93%. Of these 70 patients, 21 (30%) had axillary nodal metastases identified pathologically. Four of these 21 (19%) had sentinel nodes negative for metastases. All 4 false-negative patients had prior excisional biopsies. The false-negative group had a larger mean maximal biopsy dimension than the true-positive group. Eleven of the 21 patients with axillary metastases had a diagnosis made by core needle biopsy with no false negatives.

CONCLUSIONS

The accuracy of the sentinel node biopsy in correctly predicting the status of remaining axillary lymph nodes may be limited in patients with large excision before radiolocalization of the sentinel node. Our findings suggest that excisional biopsy should be avoided prior to lymphatic mapping for sentinel node biopsy.

Sodium nitroprusside (SNP) hypotension: intracranial pressure (ICP) and hemodynamics in pial arteriole in the rat

A detailed description is made of an acute closed cranial window method. The method is used for the study of cerebral pial microcirculation by intravital microscopy in the rat. Using these methods and techniques, the effects of systemic hypotension by SNP, i.v., on pial microvessel hemodynamics and on ICP were simultaneously measured and characterized under normophysiological conditions. The pH, PO2, PCO2 and temperature of the artificial cerebrospinal fluid (CSF) in the closed cranial window, intermittently measured, remained relatively constant, 30 to 60 min following the period of stabilization of the preparation. The infusion of SNP (6.2-35.0 micrograms/kg/min, 0.02% sol., i.v.) significantly decreased BP (52.1 +/- 13.4 mm Hg, mean +/- SD). From measurement of microvessels internal diameter (I. D.) and microhemodynamics, significant increases in pial arteriolar I.D. (from 35.4 +/- 10.1, microns, to 47.1 +/- 5.7, microns, mean and S.D., 33.0%) and estimated bulk flow (51.2%), occurred during the hypotension. The changes in hemodynamic parameter were predominantly in the arteriolar system. Only minimal changes in the venular diameter occurred during the SNP hypotension. The observed moderate (22.0%) increase in ICP during SNP hypotension in pentobarbital anesthetized rat correlates well with the microhemodynamic changes of the cerebral microcirculatory system.

The nucleus locus coeruleus modulates local cerebral glucose utilization during noise stress in rats

Local cerebral glucose utilization (LCGU), estimated by the quantitative autoradiographic 2-deoxyglucose technique, was studied in rats with bilateral 6-hydroxydopamine lesions of the locus coeruleus (LC) and in vehicle-injected controls. Unanesthetized animals were studied during exposure to stressful levels of white noise (95 dB) or in relative silence (50 dB). Results indicated that noise caused greater and more widespread increases in LCGU in animals with LC lesions than in vehicle-injected controls. Lesions alone had little or no effect in animals not subjected to noise. Analyses of variance revealed significant treatment interaction effects (intact/lesion x silence/noise) for 37 of 109 regions measured. The pattern of results suggests that the LC acts during stress to limit unnecessary cerebral activity that might interfere with efficient sensory processing and/or the organization of appropriate behavioral responses. In this respect LC function may be similar to those actions of the peripheral sympathetic nervous system that suppress vegetative functions during stress to allow for the performance of coping responses.

Evaluating the anti-plaque capabilities of a copper-containing prophylaxis paste

The purpose of this study was to evaluate a dental prophylaxis paste containing mono-copper citrate (MCC) for short term anti-plaque capabilities. In addition to other baseline data, plaque scores were recorded on 36 paid volunteer subjects from the dental school student, staff, and faculty populations. After scaling, two quadrants of each subject's dentition were polished with the MCC containing paste and two quadrants with the placebo paste, using a diagonal split mouth double blind design. Subjects did not brush or floss for two days. Plaque scores were recorded at 24 and 48 hours, after which they resumed normal hygiene. Results showed that after 24 hours placebo areas had 92% higher plaque and after 48 hours 33% higher plaque than the active paste areas. This was statistically significant at the P less than .001 level. The diminishing effect of the copper containing prophy paste over 48 hours might indicate that the copper ion should be applied on a daily basis for best anti-plaque results.

Functional neuroanatomic mapping of the rat striatum: regional differences in glucose utilization in normal controls and after treatment with apomorphine

Glucose utilization was measured in 5 regions of rat striatum within four anterior-posterior levels. Areas of minimal and maximal glucose utilization were identified. Density-window image analysis was used to quantify areas of minimal and maximal glucose utilization, which were also apparent upon close visual inspection. In a normal control group, there were substantial regional variations in striatal glucose utilization (e.g. dorsal vs ventral; dorsomedial vs dorsolateral), revealing a detailed pattern, previously unavailable, which served as a baseline to study the effect of systemic apomorphine. The highest levels of glucose utilization were in small islands 0.01-0.25 mm2, and in what appeared to be dense clusters of islands that formed larger zones. Apomorphine treatment decreased glucose utilization in dorsomedial regions, increased it in a ventromedial region, and did not change it in others. The findings emphasize the importance of regional analysis of striatum in functional and physiological studies, and provide a new baseline for analyses of striatal glucose utilization in studies of development and aging, drug effects, external stimuli, and rat models of movement disorders.

Bleeding gastric varices and gastric torsion secondary to a wandering spleen

We are reporting a patient who presente with upper gastrointestinal bleeding which was in part caused by a wandering spleen. Endoscopy revealed erosions of gastric varices in the presence of gastric torsion. At surgical exploration the spleen was present in the pelvis. The twisted and elongated splenic pedicle resulted in a markedly dilated venous system of the proximal stomach and the engorged spleen. The literature of the wandering spleen is reviewed.

The value of repetition and reinforcement in improving oral hygiene performance

The purpose of this study was to assess the value of including repetition and reinforcement in a dental health education program for school children. Sixty-one pupils, 11 to 13 years of age, were divided into three groups according to room assignments. Group I (control) received no oral hygiene lectures or instructions until the conclusion of the experiment. Group 2 (nonreinforced) received one lecture and a toothbrushing lesson, but no repetition or reinforcement. Group 3 (reinforced) received the same program as Group 2 on the initial visit and also received two additional visits for repetition and reinforcement of the lectures and instructions, plus a final summary lecture. Six visits were conducted at intervals of 0, 1, 5, 3, 8, 20 and 52 weeks, following a double-blind experimental format. PHP scores were obtained on all subjects on each of the six visits. It was concluded that the repetition and reinforcement components of this dental health education program were of significant value in improving the oral hygiene performance of the school children over a period of 1 year. The findings provide evidence of the desirability of incorporating these concepts in plaque-control program.

Microvascular responses to norepinephrine and vasopressin during halothane anesthesia in the rat

This experiment was designed to determine the microvascular responses to the two known naturally occurring vasoconstrictors, norepinephrine (NE) and vasopressin, at known levels of central vasomotor activity before, during and after halothane anesthesia. The responses to topical application of NE and vasopressin were studied in the microvasculature of the mesentery and cremaster muscle, using microscopic methods. Neural (CNS) stimulation was accomplished through electrodes chronically implanted in vasoactive sites of the forebrain and midbrain. The increase in blood pressure in response to CNS stimulation was decreased during halothane anesthesia (32.4 +/- 5.4 per cent before and 24.7 +/- 6.1 per cent during; P less than 0.001). There was no significant change in the steady-state diameter of the microvasculature under study during or after halothane anesthesia. Marked abatement of arteriolar vasoconstriction in response to CNS stimulation was seen prior to halothane. However, the same target vessel showed increased constriction in response to topically applied NE (from 32.3 +/- 4.7 to 53.2 +/- 7.8 per cent; P less than 0.01) during halothane anesthesia. By contrast, the response to vasopressin decreased (from 42.4 +/- 5.7 to 1.0 +/- 6 per cent; P less than 0.001) with halothane. The precise mechanism(s) underlying the described hypersensitivity to NE and hyposensitivity to vasopressin in the same vascular structure during halothane anesthesia remains undetermined.

Course evaluation by committee

An intradepartmental course evaluation committee has been established in the Department of Community Dentistry at the University of Louisville School of Dentistry. This committee's review of student evaluation mechanisms was a major focus in the assessment of all departmental courses. An evaluation technique, based on a comparison of existing student evaluation mechanisms against criteria established by the committee and approved by the departmental faculty, was designed and applied. The committee was viewed as successful by departmental course directors; however, its suggestions were not widely implemented by the departmental faculty. Several reasons are cited for this, as well as suggestions for future modifications of the committee's procedures.

Central neural influence on precapillary microvessels and sphincter

The responses to central nervous system (CNS) stimulation of consecutive segments of arterioles down to the precapillary sphincter were measured in the mesoappendix and/or cremaster of nine male rats with indwelling electrodes. Under pentobarbital sodium anesthesia, vasoactive sites were stimulated at threshold for maximal constriction or lumen closure of the precapillary sphincter and/or immediately preceding precapillary arteriole (metarteriole). In all experiments, CNS stimulation induced blood pressure elevation and constriction of three consecutive segments of precapillary vessels and of the sphincter. A threefold increase in rate of vasomotion of precapillary sphincter and metarteriole was the rule, but this was noted infrequently in larger arterioles. In addition to an overall influence of the CNS on microcirculation, the data show a gradient of responses to stimulation, the slope of which is negatively related to the size of the vessels and sphincter, in both tissues studied. A complete lumen closure of the metarteriole and precapillary sphincter (when present) in response to CNS stimulation implies active participation in the regulation of local blood flow. No evidence was foun for central neural regulation of the precapillary sphincter independent of arteriolar control.

Reversal of hypercoagulable state by bilateral nephrectomy

The hypercoagulable state associated with select cases of glomerulonephritis is difficult to diagnose by standard laboratory techniques but is clinically manifested by recurrent shunt and fistula thrombosis which may be refractory to anticoagulant therapy. Bilateral nephrectomy reversed this hypercoagulable state. After renal allograft, however, the patient experienced hyperacute rejection, and transplant nephrectomy was required to cure the recurrent hypercoagulable state. The mechanism of this previously unreported phenomenon and its implications with regard to renal transplantation are discussed.

Somatosensory thalamic neurons: effects of cortical depression

Deafferented somatosensory thalamic neurons showed hyperactivity, followed by greatly reduced activity, after initiation of cortical spreading depression; local cooling of sensorimotor cortex was followed only by the inactive phase. Stimulation of contralateral midbrain reticular formation during the inactive phase failed to induce the typical increase in discharge rate of somatosensory thalamic neurons, but produced desynchronization in unaffected cortex. These results indicate that corticothalamic discharge is necessary for sustaining the ongoing activity of deafferented somatosensory thalamic neurons and for maintaining their responsiveness to stimulation of the reticular formation.