Low-dose ipilimumab plus nivolumab combined with IL-2 and hyperthermia in cancer patients with advanced disease: exploratory findings of a case series of 131 stage IV cancers - a retrospective study of a single institution

The 3-year overall survival (OS) rate of patients with previously treated or untreated stage III or IV melanoma has by now reached 63% using ipilimumab and nivolumab therapy. However, immune-related adverse events (irAEs) of grade 3 or 4 occurred in 59% of patients leading to discontinuation of therapy in 24.5% of patients and one death. Therapy with checkpoint inhibitors could be safer and more effective in combination with hyperthermia and fever inducing therapies. We conducted a retrospective analysis to test the safety and efficacy of a new combination immune therapy in 131 unselected stage IV solid cancer patients with 23 different histological types of cancer who exhausted all conventional treatments. Treatment consisted of locoregional- and whole-body hyperthermia, individually dose adapted interleukin 2 (IL-2) combined with low-dose ipilimumab (0.3 mg/kg) plus nivolumab (0.5 mg/kg). The objective response rate (ORR) was 31.3%, progression-free survival (PFS) was 10 months, survival probabilities at 6 months was 86.7% (95% CI, 81.0–92.8%), at 9 months was 73.5% (95% CI, 66.2–81.7%), at 12 months was 66.5% (95% CI, 58.6–75.4%), while at 24 months survival was 36.6% (95% CI:28.2%; 47.3%). irAEs of World Health Organization (WHO) Toxicity Scale grade 1, 2, 3, and 4 were observed in 23.66%, 16.03%, 6.11%, and 2.29% of patients, respectively. Our results suggest that the irAEs profile of the combined treatment is safer than that of the established protocols without compromising efficacy.

Abstract PD3-04: Analysis of ERBB2 (HER2) amplification by ctDNA in a phase Ib dose-escalation trial evaluating trastuzumab emtansine (T-DM1) with neratinib in women with metastatic disease with initially diagnosed HER2+ breast cancer: NSABP FB-10

Background:

In this phase Ib study, the activity of T-DM1 plus N was assessed in patients (pt) previously treated with trastuzumab, pertuzumab, and a taxane (H+P+T). Several mechanisms of resistance have been hypothesized in pts progressing following H+P+T, including acquired alterations in the ERBB (HER) family proteins, reactivation of bypass or parallel pathways, or selective elimination of HER2-overexpressing clones. Loss of HER2 amp has been shown to occur in 25-35% of pts with residual tumor after neoadjuvant therapy or in metastatic disease after initial therapy with chemotherapy and HER2-targeted agents. Data on concordance of HER2 status between tissue and blood is limited. In 7 pts with cfDNA HER2 amp, concomitant tissue was concordant in all 7 pairs and response to anti-HER2 therapy occurred in 6. In our study we have retrospectively analyzed cfDNA in blood samples obtained at study entry.

Methods:

Eligible pts had prior H+P+T as neoadjuvant therapy, or 1st-line metastatic disease, measurable disease, ECOG PS ≤2, and adequate hematologic, renal, and liver function. Pts with stable brain metastases were eligible. Treatment consisted of T-DM1 3.6 mg/kg iv q3wk and N 120, 160, 200, or 240 mg/d using a 3+3 dose-escalation design. HER2+ was determined at initial diagnosis; tissue confirmation at study entry (after H+P+T progression) was not required. Blood was collected in for pharmacokinetic analyses of N peak and trough, and for cfDNA using the Guardant360 assay, which is a 73-gene next-generation cfDNA-sequencing panel that detects SNVs, indels, CNAs, and fusions, utilizing Digital Sequencing and custom bioinformatics methods for error correction. The cut-off for HER2 amp was a copy number of ≥2.0 established by Guardant based on training-set data.

Results:

There were 27 H+P+T-resistant pts enrolled and all pts had a blood sample analyzed for HER2 amp. Eighteen pts were evaluable for efficacy at 6 wks and 11 pts at 12 wks. Dose-limiting toxicity occurred in 6 pts during cycle 1, 1 pt was withdrawn for non-compliance, and 2 pts were withdrawn for disease complications. The recommended phase II dose of N was determined to be 160 mg/d. Responses were seen at all dose-levels of N. Pharmacokinetic analyses did not show a clear relationship with either peak or trough and dose-level. Ten pts showed HER2 amp in blood and 17 were non-amp. Of 18 pts evaluable after 2 cycles (6 wks), 12 pts had an objective response (7 amp; 5 non-amp) and 5 had progressive disease (1 amp; 4 non-amp). At 12 wks, there were 3 CRs and 8 PRs (7 amp; 4 non-amp). All CRs were in amp pts and lasted 364, 510, and 859+ days.

Conclusions:

HER2 amp as determined by cfDNA was found in 10 of 27 pts. The deeper and more prolonged (>12 wk) responses occurred in 7 of 10 amp HER2 pts v 4 of 17 non-amp HER2 pts (p=0.04). In our ongoing phase II study of this regimen concomitant tissue and blood will be analyzed to better understand potential benefit or lack of benefit, with continued use of anti-HER2 therapy after progression on anti-HER2 therapies.

Support: Puma Biotechnology, Inc.

Citation Format: Abraham J, Puhalla SL, Sikov WM, Montero AJ, Salkeni MA, Razaq WA, Beumer JH, Kiesel BF, Buyse ME, Adamson LM, Srinivasan A, Pogue-Geile KL, Allegra CJ, Nagy RJ, Jacobs SA. Analysis of ERBB2 (HER2) amplification by ctDNA in a phase Ib dose-escalation trial evaluating trastuzumab emtansine (T-DM1) with neratinib in women with metastatic disease with initially diagnosed HER2+ breast cancer: NSABP FB-10 [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-04.

Abstract PD4-05: Patterns of genomic alterations in ER-positive advanced breast cancer patients treated with CDK4/6 inhibitors

Background:Cyclin D kinase inhibitors (CDK-is) have shown clinical efficacy in estrogen receptor (ER)-positive metastatic breast cancer (MBC) when combined with aromatase inhibition or estrogen receptor (ER) antagonism. Despite the benefit of this approach, clinical resistance develops sometimes early in the treatment without any response to endocrine therapy (primary endocrine resistance) or after initial response (secondary resistance) in all patients in the metastatic setting and the molecular basis for this resistance are still largely unknown. We evaluated the pattern of genomic alterations in circulating cell-free tumor DNA (ctDNA) analysis of metastatic breast cancer patients with ER-positive tumors treated with palbociclib combined with either letrozole or fulvestrant and progressing during therapy.

Methods: We conducted a retrospective study of patients with ER-positive MBC who had longitudinal assessment of their disease by ctDNA analysis. The plasma-based assay was performed utilizing Guardant360 (Guardant Health, CA), a digital NGS technology to sequence a panel of > 50 cancer genes. After tabulating number of genomic alterations detected for every patient at baseline and after CDK-i therapy, analysis was performed to identify molecular profile changes in the entire population and in individuals with early progression of disease (<6 months).

Results: We analyzed data of 15 ER-positive MBC patients: 8 patients received fulvestrant/palbociclib and 7 received letrozol/palpociclib. The most common mutations before CDK-i therapy were: PIK3CA (16%), TP53 (16%), ESR1 (13%), KIT (9%), EGFR (3%), APC (3%), ERBB2 (3%), MYC (3%), PTEN (3%), RB1 (3%). After therapy with CDK-i the pattern of mutations showed stable and persistent incidence of PIK3CA, TP53 and ESR1. However, new mutations where identified: FGFR1 (6%), IDH (2%), BRCA1 (2%), BRCA2 (2%), CCNE (2%), CCND1 (2%), RAF (2%), AR (2%), ALK(2%). Also, the pattern of gene amplifications presented an increased rate of MYC and FGFR1 amp. Patients with progression of disease before 6 months of CDK-i therapy presented baseline higher number and variation of mutations compared to patients with disease controlled beyond 6 months of therapy.

Conclusion: Longitudinal assessment with ctDNA analysis suggest that a genomic alteration landscape consisting of persistent detection of driver and acquired mutations along with emergent new abnormalities in regulatory genes could potentially be related to primary or secondary resistance to CDK-Is in ER+ MBC patients. Future investigation of these alterations should be conducted.

Citation Format: Cruz MR, Limentani K, Taxter T, Santa-Maria CA, Behdad A, Gradishar WJ, Nagy RJ, Cristofanilli M. Patterns of genomic alterations in ER-positive advanced breast cancer patients treated with CDK4/6 inhibitors [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 PD4-05.

Abstract PD1-02: Circulating tumor DNA (ctDNA): A real-time application of precision medicine to the management of metastatic breast cancer (MBC)

Background: Molecular diagnostic, in particular next-generation sequencing (NGS) technologies, improved the detection of actionable mutations (muts) in MBC at baseline and recurrence. We evaluated the ability of ctDNA to detect molecular abnormalities, monitor disease progression and predict outcome.

Methods: We conducted a retrospective study of 91 patients (pts) with locally advanced and MBC, who had longitudinal assessment of their disease by ctDNA analysis. The plasma-based assay was performed utilizing Guardant360 (Guardant Health, CA), a digital NGS technology to sequence a panel of > 50 cancer genes. After tabulating number of muts and quantification of overall ctDNA detected for every patient at baseline, a receiver operating characteristic (ROC) analysis was performed to identify the best cut-offs that separated the pts who had a disease progression from those who hadn't, and the patients who died from those still alive. The overall survival (OS) analysis has been performed using Kaplan-Meier curves.

Results: 84 pts (92%) had stage IV cancer. 63% cases were ER+, 27% HER2+, 29% TNBC. 277 blood samples were collected and 84% had muts. 65% of the pts had serial samples. The average number of alterations detected in each sample was 3 (0-27) and the average ctDNA fraction detected was 4.5% (0-88.2%). The most common alterations were: TP53 (52%), PIK3CA (40%), ERBB2 (20%), NOTCH1 (15.5%), APC (14%), MET (13%). 16 pts (19%) were initiated on a targeted therapy based on ctDNA test results. At the time of analysis 36 pts (39.6%) were dead, 55 (60.4%) were currently alive. PFS was 5.2 months (ms) and OS was 21.5 ms. A statistically significant difference in PFS and OS by log rank test was found between % ctDNA at baseline < 0.5 versus ≥ 0.5 (p = 0.003 and p = 0.012, respectively) and number of muts at baseline < 2 versus ≥ 2 (p = 0.059 borderline and p = 0.0015). Moreover, a statistically significant association by Fisher's exact test was found between the number of alterations and the % ctDNA detected in the baseline sample (% of pts with muts ≥ 2 was 19% when % ctDNA < 0.5%, versus 85% when % ctDNA ≥ 0.5%; p < 0.0001).

PFS (ms) p = 0.059 (log rank test)Muts < 2 (n = 32)Muts ≥ 2 (n = 58)658%40%1230%13%1821%6%24--PFS(ms) p = 0.003 (log rank test)% ctDNA < 0.5(n = 27)% ctDNA ≥ 0.5(n = 60)665%39%1241%10%1823%6%24--

OS(ms) p = 0.002 (log rank test)Muts < 2(n = 32)Muts ≥ 2(n = 57)697%66%1288%51%1888%42%24-29%OS(ms) p = 0.012 (log rank test)% ctDNA < 0.5(n = 27)% ctDNA ≥ 0.5(n = 59)696%69%1290%55%1885%48%24-35%

Conclusions: ctDNA liquid biopsy provides a real-time, quantitative NGS-based assessment of MBC which is useful for treatment planning, disease monitoring and prognostic evaluation. Future prospective studies should consider the use of ctDNA for molecular and prognostic stratification.

Citation Format: Rossi G, Austin LK, Nagy RJ, Rademaker AW, Gradishar WJ, Santa-Maria CA, Curry-Edwards RL, Jain S, Flaum LE, Lima Barros Costa R, Zagonel V, Platanias LC, Giles FJ, Talasaz A, Cristofanilli M. Circulating tumor DNA (ctDNA): A real-time application of precision medicine to the management of metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD1-02.

Abstract P1-05-06: Estrogen receptor 1 (ESR1) mutations in circulating tumor DNA (ctDNA): A guide to the management of advanced breast cancer (ABC)

Background: Estrogen receptor (ER)-α is expressed in about 70% of breast cancers and drugs that target the receptor function, selective estrogen receptor modulators (SERM) and aromatase inhibitors (AIs) represent the standard of care for patients (pts) with ER+ breast cancer. Nevertheless, prolonged exposure to endocrine therapy may result in acquired resistance and subsequent progression of disease. Recent evidence showed that activating mutations (muts) in the ligand-binding domain of ER-α occur in approximately 20% of pts exposed to endocrine therapies and those genomic abnormalities may represent the driver of endocrine resistance. In this context, ctDNA provides a non-invasive source for real-time next generation sequencing (NGS) studies, in order to understand the biology of ABC and guide and monitor treatment.

Methods: We conducted a retrospective review of 91 pts with ABC, including 57 pts with ER+ tumor, who had longitudinal assessment of their disease by ctDNA analysis. At the time of baseline sampling, 50/57 pts had stage IV cancer. The total number of blood samples collected was 184. 38 (67%) pts had serial samples. The average number of samples for each pt was 3 (range 1-7). The plasma-based assay was performed utilizing Guardant360 (Guardant Health, CA), a digital NGS technology to sequence a panel of > 50 cancer genes.

Results: Among the ER+ subgroup (57 pts), we identified 11 pts (19%) harboring ESR1 muts in ctDNA. All 11 pts had metastatic disease: 2 (18%) had bone metastases, 2 (18%) had visceral metastases, 7 (64%) had both sites of disease. The median age was 55 years (range 33-73). 5 pts had inflammatory breast cancer. The most common ESR1 muts were: Y537S (6/11, 55%), D538G (4/11, 36%) and Y537N (3/11, 27%). 7 pts carried polyclonal muts. At the time of testing, 10 pts had already failed at least 1 line of endocrine therapy (average 2, range 1-5), including 6 pts that had received a fulvestrant-containing regimen, 8 pts ≥ 1 line of AIs. After the mut detection, 5 pt were on endocrine therapy and 4 pts were started on/continued chemotherapy. ESR1 muts disappeared in 2 pts (fulvestrant-palbociclib and chemotherapy respectively) who achieved stable disease as best response. Three pts continued to harbour muts and then progressed (one died). 2 pts had tissue NGS and ESR1 mut was not identified. Progression free survival and overall survival were 8 months (ms) and 21.5 ms in ESR1+ subpopulation versus 6.2 ms and 22.2 ms in the ESR1- pts (p = 0.78 and p = 0.97, respectively). At the time of analysis 5 pts were dead, 6 were currently alive.

  ESR1+ (n. pts) ESR1- (n. pts) Pts (total n.)1146 Previous chemotherapies11 (100%)31 (67%) Previous fulvestrant-containing regimens6 (54%)20 (43%) Previous AIs ± targeted therapy8 (73%)27 (59%)

Conclusions: We observed that ESR1 muts, a known driver of endocrine resistance, occurs at a high frequency in heavily pre-treated estrogen receptor positive ABC. Blood-based diagnostics can be used to identify ESR1 muts sometimes not detected by tissue-based sequencing of the metastatic lesions indicating tumor heterogeneity and allowing dynamic monitoring of ABC.

Citation Format: Rossi G, Lima Barros Costa R, Nagy RJ, Rademaker AW, Gradishar WJ, Santa-Maria CA, Curry-Edwards RL, Jain S, Flaum LE, Zagonel V, Platanias LC, Giles FJ, Talasaz A, Cristofanilli M. Estrogen receptor 1 (ESR1) mutations in circulating tumor DNA (ctDNA): A guide to the management of advanced breast cancer (ABC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-06.

Citrobacter freundii as a test platform for recombinant cellulose degradation systems

Cellulosic biomass represents a huge reservoir of renewable carbon, but converting it into useful products is challenging. Attempts to transfer cellulose degradation capability to industrially useful micro-organisms have met with limited success, possibly due to poorly understood synergy between multiple cellulases. This is best studied by co-expression of many combinations of cellulases and associated proteins. Here, we describe the development of a test platform based on Citrobacter freundii, a cellobiose-assimilating organism closely related to Escherichia coli. Standard E. coli cloning vectors worked well in Cit. freundii. Expression of cellulases CenA and Cex of Cellulomonas fimi in Cit. freundii gave recombinant strains which were able to grow at the expense of cellulosic filter paper or microcrystalline cellulose (Avicel) in a mineral medium supplemented with a small amount of yeast extract. Periodic physical agitation of the cultures was highly beneficial for growth at the expense of filter paper. This provides a test platform for the expression of combinations of genes encoding biomass-degrading enzymes to develop effective genetic cassettes for degradation of different biomass streams.

SIGNIFICANCE AND IMPACT OF THE STUDY

Biofuels have been shown to be the best sustainable and alternative source of fuel to replace fossil fuels. Of the different types of feedstocks used for producing biofuels, lignocellulosic biomass is the most abundant. Converting this biomass to useful products has met with little success. Different approaches are being used and microbial platforms are the most promising and sustainable method. This study shows that Citrobacter freundii is a better test platform than Escherichia coli for testing various combinations of cellulases for the development of microbial systems for biomass conversion.

Abstract P3-05-02: Detection of activating estrogen receptor 1 (ESR1) in circulating tumor DNA (ctDNA) in hormone-receptor positive metastatic breast cancer (MBC)

Background

About 65% of breast cancers express the estrogen receptor α and the mainstay of treatment are therapies that result in estrogen receptor modulation (selective estrogen receptor modulators, SERMs) or estrogen deprivation (aromatase inhibitors, AIs). Even though endocrine therapy has resulted in reduced recurrence and mortality, a significant portion of patients relapse with metastatic disease and subsequently progress while on therapy for advanced disease (endocrine resistance). Recent evidence showed that activating hot spot mutations in the ligand binding domain of the ERα (ESR1) are acquired on treatment (frequency of 20%) and can drive resistance to endocrine therapy, especially AIs. ESR1 mutations can be detected by evaluation of circulating tumor DNA (ctDNA), a method where circulating DNA fragments with tumor-specific sequence alterations are identified in the blood of patients.

Methods

This is a retrospective evaluation of 9 patients with hormone receptor positive (HR+) metastatic breast cancer (MBC) who had progressed on multiple lines of endocrine therapy (ET) and were found to have ESR1 mutations in ctDNA. Patients had blood drawn for ctDNA analysis either at progression to serve as a baseline before starting a new regimen or to monitor response to ongoing treatment. Guardant360™(Guardant Health) involves ctDNA isolation from plasma using a Qiagen circulating nucleic acid kit, then a panel of 68 gene mutations associated with solid tumors as reported in the COSMIC database sequenced using single-molecule digital sequencing technology.

Results

All of the patients had MBC and were luminal subtype except for one HER2+, and most had invasive ductal carcinoma although 2 patients were invasive lobular carcinoma (22%). Most patients had both bone and visceral involvement (78%), only two patients had bone only metastasis. The patients were generally heavily pretreated with an average of 3 lines of ETs and 6 lines of therapy altogether (chemotherapy + ET). Duration on endocrine therapy ranged from 23 months to 7 years (mean 4.3 years). All patients were found to have ESR1 mutations on ctDNA, the range of percentage of mutant allele was 0.28-23.76%. Three patients had tissue sent for NGS and none of the tissue samples had an ESR1 mutation detected although they were biopsied at various time points in treatment. One of those patients had two ESR1 mutations in ctDNA, which were not detected on tissue sent for NGS one year prior, and had not been on ET for several years. One patient with abdominal carcinomatosis from lobular carcinoma who had been on ETs therapies for 6 years was found to have 4 distinct ESR1 mutations in a single blood draw, suggesting sub-clonal evolution of resistance. One patient also had 5 circulating tumor cells, all of which had ESR1 mutations detected when circulating tumor cells were individually sequenced.

Conclusions

ctDNA is a sensitive test for detection of ESR1 in HR+ MBC patients, with the advantage of being a blood based assay which lends itself to serial analysis. In this patient population ctDNA can be a helpful tool to predict response to ET and predict treatment failure.

Citation Format: Austin L, Rodriguez A, Jaslow R, Fortina P, Nagy R, Zill O, Talasaz A, Cristofanilli M. Detection of activating estrogen receptor 1 (ESR1) in circulating tumor DNA (ctDNA) in hormone-receptor positive metastatic breast cancer (MBC). [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 P3-05-02.

Microcephalic osteodysplastic primordial dwarfism type I with biallelic mutations in the RNU4ATAC gene

Microcephalic osteodysplastic primordial dwarfism type I (MOPD I) is a rare autosomal recessive developmental disorder characterized by extreme intrauterine growth retardation, severe microcephaly, central nervous system abnormalities, dysmorphic facial features, skin abnormalities, skeletal changes, limb deformations, and early death. Recently, mutations in the RNU4ATAC gene, which encodes U4atac, a small nuclear RNA that is a crucial component of the minor spliceosome, were found to cause MOPD I. MOPD I is the first disease known to be associated with a defect in small nuclear RNAs. We describe here the clinical and molecular data for 17 cases of MOPD I, including 15 previously unreported cases, all carrying biallelic mutations in the RNU4ATAC gene.

Differential regulation of five Pht1 phosphate transporters from maize (Zea mays L.)

Maize is one of the most important crops in the developing world, where adverse soil conditions and low fertilizer input are the two main constraints for stable food supply. Understanding the molecular and biochemical mechanisms involved in nutrient uptake is expected to support the development of future breeding strategies aimed at improving maize productivity on infertile soils. Phosphorus is the least mobile macronutrient in the soils and it is often limiting plant growth. In this work, five genes encoding Pht1 phosphate transporters which contribute to phosphate uptake and allocation in maize were identified. In phosphate-starved plants, transcripts of most of the five transporters were present in roots and leaves. Independent of the phosphate supply, expression of two genes was predominant in pollen or in roots colonized by symbiotic mycorrhizal fungi, respectively. Interestingly, high transcript levels of the mycorrhiza-inducible gene were also detectable in leaves of phosphate-starved plants. Thus, differential expression of Pht1 phosphate transporters in maize suggests involvement of the encoded proteins in diverse processes, including phosphate uptake from soil and transport at the symbiotic interface in mycorrhizas, phosphate (re)translocation in the shoot, and phosphate uptake during pollen tube growth.

Direct Evidence of Ionic Fluxes Across Ion-Selective Membranes: A Scanning Electrochemical Microscopic and Potentiometric Study

Scanning electrochemical microscopy (SECM) supplemented with potentiometric measurements was used to follow the time-dependent buildup of a steady-state diffusion layer at the aqueous-phase boundary of lead ion-selective electrodes (ISEs). Differential pulse voltammetry is adapted to SECM for probing the local concentration profiles at the sample side of solvent polymeric membranes. Major factors affecting the membrane transport-related surface concentrations were identified from SECM data and the potentiometric transients obtained under different experimental conditions (inner filling solution composition, membrane thickness, surface pretreatment). The amperometrically determined surface concentrations correlated well with the lower detection limits of the lead ion-selective electrodes.

The effects of a single course of a calculus-softening scaling and root planing gel. A scanning electron microscopic study

The effect of a calculus scaling gel was evaluated as an adjunct to instrumentation in a double blind, split-mouth, clinical study. Fifteen comparable periodontally involved teeth from 5 patients were instrumented on the mesio-buccal root surface with the aid of either the test gel, placebo gel, or no gel until smoothness was achieved. Test or placebo gel was applied subgingivally for 10 minutes. Instrumentation time, ease, number of strokes, and gingival/tooth surfaces changes were recorded. Scanning electronic microscopic (SEM) evaluation of root surface topography was evaluated. The results demonstrated effective calculus removal in all treatment groups with no differences found between them. Instrumentation time, ease, and number of strokes were similar for all treatment groups. There were no harmful effects to soft or hard tissues. The results of this study do not support the use of calculus scaling gel as an adjunct to root instrumentation.

Comparison of postoperative bupivacaine with lidocaine on pain and analgesic use following periodontal surgery

The purpose of this study was to compare postoperative administration of bupivacaine, a long-acting local anesthetic, with lidocaine, a short-acting local anesthetic, on pain perception and analgesic use following periodontal surgery. Ten male subjects were selected on the basis of having similar bilateral mandibular quadrants with moderate to severe periodontal disease requiring osseous surgery. The study was a matched-pair, double-blind design. Carpules of 2% xylocaine with 1:100,000 epinephrine and 0.5% bupivacaine with 1:200,000 epinephrine were wrapped in opaque tape and placed in separate coded envelopes. At the time of suturing, the quadrant was injected with one Carpule from one envelope. The Carpules from the second envelope were saved for the second surgery, which took place approximately one month later. Subjects were given standardized postoperative instructions and prescriptions for Peridex and Tylenol #3. They were told not to take the analgesic unless pain or discomfort occurred. They were given a self-administered questionnaire and asked to assess pain and/or discomfort 2, 4, 6, 8, 10, and 12 hours after the procedure, the amount of analgesic taken, and time when complete sensation returned. Results showed that the quadrants which received lidocaine maintained postoperative anesthesia an average of 2.47 hours while the Marcaine quadrants had a significantly longer duration of 5.62 hours. A large intra- and intersubject variability was noted in the amount of analgesic taken. The lidocaine group reported an average of 3.70 tablets versus a significantly smaller amount for the bupivacaine group of 1.60 tablets. Throughout all time intervals, the bupivacaine group reported significantly less pain than the lidocaine group. When used at the end of a mandibular periodontal surgical procedure, bupivacaine provides a significantly greater duration of anesthesia, decreased postoperative pain, and a reduction of anesthesia, decreased postoperative pain, and a reduction in the amount of analgesics taken.

[A foldable cardboard box for drying and storage of by cotton swab collected biological samples]

The ability to perform successful DNA analysis on biological evidence obtained at a crime scene or during a sexual assault examination depends very much on the first step--how specimens are collected and preserved. Body fluids and their wet or dry stains, are often recovered using dry cotton swabs or cotton swabs moistened with sterile water or saline. In order to prevent decomposition and deterioration of a specimen, resulting in degradation or loss of DNA, it is recommended to either air dry or freeze these swabs as soon as possible after collection. We designed a simple, foldable cardboard box, which is suitable for the drying and storage of biological evidence collected on cotton swabs. Immediately after collection swabs are placed into the drying racks within the cardboard box, which is subsequently folded, labeled, sealed and initialed. At room temperature swabs completely air dry within the sealed box within 6-9 hours. In this box the evidence is properly packed, labelled and sealed, thus preventing cross contamination, degradation and sample switch. It is a valuable device for the collection of biological evidence at a crime scene, during sexual assault examinations, and for the collection of buccal swabs for PCR-based databasing and paternity testing.

Biological and molecular characterisation of potential biocontrol strains of Trichoderma

Thirty-four strains of seven species of Trichoderma isolated from various fungal sources were compared for direct mycoparasitic activity (MPA), chitinase production and antibiotic activity (ANA) in order to choose the most appropriate partners for a strain-breeding programme. Within species genetic differences were also assesses in T. hamatum, T. harzianum and T. viride by means of random amplification of polymorphic DNA (RAPD). Endochitinase activities of the Trichoderma strains ranged between 20.4 and 1264.5 units/g dry weight of mycelium. The correlation between MPA and chitinase activity was not unambiguous and no correlation existed between MPA and ANA. The RAPD patterns of T. viride strains were highly variable, while isolates of T. harzianum proved to be more uniform; T. hamatum revealed remarkable intraspecific divergence. All these three comprised certain pairs of strains that are promising participants of a strain-improving programme, since their strong genetic affinities offer good changes for combining their contrasted biocontrol traits.

Brain glucose uptake and unawareness of hypoglycemia in patients with insulin-dependent diabetes mellitus

BACKGROUND

In patients with insulin-dependent diabetes mellitus (IDDM) whose treatment results in nearly normal mean plasma glucose concentrations, an unawareness of hypoglycemia can develop, and such patients are at increased risk for seizures and coma. We tested the hypothesis that during hypoglycemia, these patients would have normal glucose uptake in the brain and that consequently no sympathoadrenal activation would begin, resulting in an unawareness of hypoglycemia.

METHODS

We measured glucose uptake in the brain at plasma glucose concentrations of 105 and 54 mg per deciliter (5.8 and 3.0 mmol per liter) in 24 patients with IDDM, stratified into three groups according to their glycosylated hemoglobin values (mean [+/- SD] values, 7.2 +/- 0.5, 8.5 +/- 0.4, and 10.2 +/- 1.3 percent) and compared the values for brain glucose uptake with those measured in 15 normal subjects at plasma glucose concentrations of 85 and 55 mg per deciliter (4.2 and 3.1 mmol per liter). We also recorded the subjects' hypoglycemic-symptom scores and measured their plasma concentrations of counterregulatory hormones.

RESULTS

There was no significant change in the uptake of glucose in the brain (calculated as the uptake during hypoglycemia minus the uptake during normoglycemia) among the patients with IDDM who had the lowest glycosylated hemoglobin values (+0.6 +/- 2.0 mg [3.3 +/- 11.1 mumol] per 100 g of brain tissue per minute, P = 0.39). Conversely, glucose uptake in the brain fell in both the group with intermediate values (a decrease of 1.3 +/- 1.0 mg [7.2 +/- 5.6 mumol] per 100 g per minute, P = 0.009) and the group with the highest values (a decrease of 1.8 +/- 1.6 mg [10.0 +/- 9.0 mumol] per 100 g per minute, P = 0.01), as it did in the normal subjects (a decrease of 1.6 +/- 1.8 mg [9.0 +/- 10.1 mumol] per 100 g per minute, P = 0.003). The responses of plasma epinephrine and pancreatic polypeptide and the frequency of symptoms of hypoglycemia were lowest in the group with the lowest glycosylated hemoglobin values.

CONCLUSIONS

During hypoglycemia, patients with IDDM who have nearly normal glycosylated hemoglobin values have normal glucose uptake in the brain, which preserves cerebral metabolism, reduces the responses of counterregulatory hormones, and causes an unawareness of hypoglycemia.

Mini-chromosomes in Fusarium sporotrichioides are mosaics of dispersed repeats and unique sequences

Variations in trichothecene patterns of 26 Fusarium sporotrichioides isolates from different plant and geographic origins showed no correlation with electrophoretic karyotype polymorphisms. When intact chromosomes were examined, interisolate karyotype differences were observed only in the mini-chromosome range. Further polymorphisms were revealed in Notl-digested samples. By summing the Notl fragments the average genome size of F. sporotrichioides was estimated to be 20.4 Mb. Mini-chromosomes shared common sequences with the larger ones; however, clones (RMS-1 and RMS-2) specific to these structures have also been found. These clones contained no coding region and no promising similarities were observed when they were compared to sequences held at GenBank. Mini-chromosomes in F. sporotrichioides constitute a mosaic composed of dispersed repeats and unique sequences. This mosaic structure was maintained in all noninterbreeding, genetically isolated strains examined.

Adaptation in brain glucose uptake following recurrent hypoglycemia

Brain glucose metabolism is impaired during hypoglycemia, but, if sustained, brain metabolism reverts to normal in animal models--data in man are lacking. We tested the hypothesis that adaptations occur to allow maintenance of normal rates of brain glucose uptake (BGU) following recurrent hypoglycemia in man. Twelve normal humans were studied over 4 days. On the initial day, arterial plasma glucose concentrations were decreased from 4.72 to 2.50 mmol/liter in five 0.56 mmol/liter steps. Cerebral blood flow, brain arteriovenous glucose difference, BGU, and cognitive function were quantitated at each step. BGU was initially impaired at the 3.61 mmol/liter glucose step (P = 0.04) and was antedated by increments in epinephrine that began at 4.16 mmol/liter (P = 0.03). The onset of hypoglycemic symptoms occurred during the 3.61 mmol/liter glucose step (P = 0.02), whereas tests of cognitive function generally deteriorated at the 3.05 mmol/liter step (P < 0.05). During the next 56 hr, mean glucose concentrations were kept at 2.9 +/- 0.1 mmol/liter and reached normal only during meals. The stepped clamp protocol was repeated beginning at 4.16 mmol/liter on the last day. No decrement in BGU was observed at any step; cognitive function was preserved until significantly lower glucose concentrations on the final day relative to the first (P = 0.04). Subjects remained asymptomatic of hypoglycemia until they reached a glucose concentration of 2.50 mmol/liter (P < 0.001 vs. day 1), while initial increments in all counterregulatory hormones were forestalled to lower glucose steps than on day 1. Therefore, adaptations occur that allow normal BGU and cerebral function to be maintained during recurrent systemic hypoglycemia. Counterregulatory events that should result in symptoms of hypoglycemia and increments in endogenous glucose production are prevented until extremely subnormal glucose concentrations.

Diminished brain glucose metabolism is a significant determinant for falling rates of systemic glucose utilization during sleep in normal humans

Systemic glucose utilization declines during sleep in man. We tested the hypothesis that this decline in utilization is largely accounted for by reduced brain glucose metabolism. 10 normal subjects underwent internal jugular and radial artery cannulation to determine cerebral blood flow by N2O equilibrium technique and to quantitate cross-brain glucose and oxygen differences before and every 3 h during sleep. Sleep stage was graded by continuous electroencephalogram, and systemic glucose turnover was estimated by isotope dilution. Brain glucose metabolism fell from 33.6 +/- 2.2 mumol/100 g per min (mean +/- SE) before sleep (2300 h) to a mean nadir of 24.3 +/- 1.1 mumol/100 g per min at 0300 h during sleep (P = 0.001). Corresponding rates of systemic glucose utilization fell from 13.2 +/- 0.8 to 11.0 +/- 0.5 mumol/kg per min (P = 0.003). Diminished brain glucose metabolism was the product of a reduced arteriovenous glucose difference, 0.643 +/- 0.024 to 0.546 +/- 0.020 mmol/liter (P = 0.002), and cerebral blood flow, 50.3 +/- 2.8 to 44.6 +/- 1.4 cc/100 g per min (P = 0.021). Brain oxygen metabolism fell commensurately from 153.4 +/- 11.8 to 128.0 +/- 8.4 mumol/100 g per min (P = 0.045). The observed reduction in brain metabolism occurred independent of stage of central nervous system electrical activity (electroencephalographic data), and was more closely linked to duration of sleep. We conclude that a decline in brain glucose metabolism is a significant determinant of falling rates of systemic glucose utilization during sleep.

Electrophoretic karyotypes and gene mapping in eight species of the Fusarium sections Arthrosporiella and Sporotrichiella

Pulsed-field gel electrophoresis was used to identify karyotypes for eight species of the Fusarium sections Arthrosporiella and Sporotrichiella. The total number of chromosome-sized DNA molecules varied from six to nine, depending on the species. The sizes of chromosomes ranged from 0.4 to approximately 6.5 Mb which gave estimates of genome size of between 27.0 and 29.9 Mb. When fractionated chromosomes of the eight species were probed with Tox5, a gene coding for the key-enzyme of trichothecene biosynthesis, strong hybridization signals developed in F. poae and F. sporotrichioides, suggesting that of the eight species examined only these two have the genetic potentiality to produce trichothecene mycotoxins. By using heterologous probes from Aspergillus different rRNA loci have also been mapped on Fusarium chromosomes.

Derivation of completely cell culture-derived mice from early-passage embryonic stem cells

Several newly generated mouse embryonic stem (ES) cell lines were tested for their ability to produce completely ES cell-derived mice at early passage numbers by ES cell <==> tetraploid embryo aggregation. One line, designated R1, produced live offspring which were completely ES cell-derived as judged by isoenzyme analysis and coat color. These cell culture-derived animals were normal, viable, and fertile. However, prolonged in vitro culture negatively affected this initial totipotency of R1, and after passage 14, ES cell-derived newborns died at birth. However, one of the five subclones (R1-S3) derived from single cells at passage 12 retained the original totipotency and gave rise to viable, completely ES cell-derived animals. The total in vitro culture time of the sublines at the time of testing was equivalent to passage 24 of the original line. Fully potent early passage R1 cells and the R1-S3 subclone should be very useful not only for ES cell-based genetic manipulations but also in defining optimal in vitro culture conditions for retaining the initial totipotency of ES cells.

Octreotide reverses hyperinsulinemia and prevents hypoglycemia induced by sulfonylurea overdoses

Emergency therapy of sulfonylurea overdoses with glucose is often unsatisfactory because glucose stimulates insulin release and initiates a need for escalating quantities of hypertonic glucose to maintain normoglycemia. We tested the hypothesis that octreotide, an analog of somatostatin, would reverse hyperinsulinemia induced by a sulfonylurea overdose. Eight normal subjects received glipizide (1.45 mg/kg) on three occasions. Within 3 h, all subjects became hypoglycemic (< 50 mg/dL) and were initially treated with 50% dextrose followed by 1) dextrose infusion, 2) octreotide (30 ng/kg.min, iv), or 3) diazoxide (300 mg, iv, every 4 h). Euglycemia (85 mg/dL) was maintained with supplementary dextrose in treatment limbs 2 and 3. Insulin concentrations were 4-5 times greater with dextrose alone or in combination with diazoxide than with octreotide (P < 0.01). Dextrose requirements during diazoxide or dextrose alone were not different, but were both greater than those during octreotide treatment (P < 0.0001). All therapies were stopped at 13 h. Glucose levels remained above 3.6 mmol/L (65 mg/dL) in six of eight subjects receiving octreotide for the remaining 4 h. Glucose fell to below 3.6 mmol/L within 1.5 h of stopping either dextrose or diazoxide in each subject. Overall, octreotide reduced and in four of eight subjects entirely eliminated the need for exogenous glucose after a large overdose of glipizide. We conclude that octreotide is safe and effective and should be strongly considered as a logical therapeutic alternative for this metabolic emergency.

The effectiveness of scaling and root planing with curets designed for deep pockets

This study evaluates the effectiveness of subgingival scaling and root planing with longer shank, thinner blade, rigid curets compared to the standard rigid Gracey curet. A total of 35 non-molar teeth from 7 patients provided 140 root surfaces for evaluation; 52 root surfaces were instrumented with the rigid longer shank curets; 52 with the standard rigid Gracey curets; and 36 provided untreated controls. A bilateral matched design was utilized where contralateral teeth in the same arch were instrumented. Instrumentation was standardized at 15 minutes per tooth. Both scaled and unscaled teeth were extracted immediately after the experimental procedures. They were viewed under a stereomicroscope with a 0.10 mm grid to assess the percent of surface covered by calculus and unaltered cementum. The curet efficiency was also evaluated. The results indicated a significant treatment effect compared to the controls in relation to the percentage of residual calculus and curet efficiency. However, there was no significant difference between the rigid longer shank and standard rigid Gracey curets. There was a difference noted when tooth surfaces were evaluated. Mesial tooth surfaces had the least remaining calculus and demonstrated the best curet efficiency.

Gravity effects on cellulose assembly

The effect of microgravity on cellulose synthesis using the model system of Acetobacter xylinum was the subject of recent investigations using The National Aeronautics and Space Administration's Reduced Gravity Laboratory, a modified KC-135 aircraft designed to produce 20 sec of microgravity during the top of a parabolic dive. Approximately 40 parabolas were executed per mission, and a period of 2 x g was integral to the pullout phase of each parabola. Cellulose biosynthesis was initiated on agar surfaces, liquid growth medium, and buffered glucose during parabolic flight and terminated with 2.0% sodium azide or 50.0% ethanol. While careful ground and in-flight controls indicated normal, compact ribbons of microbial cellulose, data from five different flights consistently showed that during progression into the parabola regime, the cellulose ribbons became splayed. This observation suggests that some element of the parabola (the 20 sec microgravity phase, the 20 sec 2 x g phase, or a combination of both) was responsible for this effect. Presumably the cellulose I alpha crystalline polymorph normally is produced under strain, and the microgravity/hypergravity combination may relieve this stress to produce splayed ribbons. An in-flight video microscopy analysis of bacterial motions during a parabolic series demonstrated that the bacteria continue to synthesize cellulose during all phases of the parabolic series. Thus, the splaying may be a reflection of a more subtle alteration such as reduction of intermicrofibrillar hydrogen bonding. Long-term microgravity exposures during spaceflight will be necessary to fully understand the cellulose alterations from the short-term microgravity experiments.

[Idiopathic thrombocytopenia caused by varicella]

The authors deal with the case of a 6-year old girl in whom thrombocytopenia developed with haemorrhagic symptoms as a rare complication of varicella. They give a short review about the reasons and the etiology of idiopathic thrombocytopenic purpura, and deal with the mechanism of thrombocytopenia caused by varicella.

The amobarbital interview in a general hospital setting, friend or foe: a case report

The amobarbital interview has been in use for over 50 years. Its clinical indications have been primarily as an aid in determining a diagnosis and in conducting psychotherapy. This article presents an overview of the procedure along with a brief historic perspective. A case is presented which highlights its potential clinical utility and shortcomings.

Mouse DNA polymerase alpha-primase terminates and reinitiates DNA synthesis 2-14 nucleotides upstream of C2A1-2(C2-3/T2) sequences on a minute virus of mice DNA template

The distribution of termination and initiation sites in a 5081-nucleotide minute virus of mice DNA template being copied by a highly purified mouse DNA polymerase alpha-DNA primase complex in the presence of GTP has been examined. The 3'-hydroxyl termini (17 in all) were clustered at six sites that were located 2-14 nucleotides upstream of C2A2C2, C2AC3, or C2A2T2 sequences. When either [alpha-32P]- or [gamma-32P]GTP was included in the DNA polymerase reaction mixtures, nascent DNA became radiolabeled. Analysis of the 32P-labeled material following treatment of the DNA with tobacco acid pyrophosphatase, bacterial alkaline phosphatase, or ribonuclease T1 revealed the presence of oligoribonucleotide chains averaging 5-7 nucleotides long and beginning with 5' GTP residues. Eight presumptive DNA primase initiation sites were located opposite C4 or C5 sequences 3-9 nucleotides upstream of one of the three closely related hexanucleotides C2A2C2, C2AC3, and C2A2T2. RNA-DNA junctions were found 3-10 nucleotides downstream of DNA primase initiation sites. The results indicate that hexanucleotides having the general formula C2A1-2(C2-3/T2), herein referred to as psi, are involved in promoting termination of DNA synthesis and/or de novo initiation of RNA-primed DNA chains by DNA polymerase alpha-primase.

ATP(GTP)-dependent conversion of MVM parvovirus single-stranded DNA to its replicative form by a purified 10 S species of mouse DNA polymerase alpha

A species of DNA polymerase alpha that is active in the ATP(GTP)-dependent conversion of MVM parvovirus single-stranded linear DNA to the duplex replicative form has been purified 4300-fold from Ehrlich ascites mouse tumour cells. The single-stranded----replicative form activity is maintained throughout ammonium sulfate precipitation, DEAE-cellulose, phosphocellulose and hydroxyapatite column chromatography and glycerol gradient sedimentation. Polypeptides with Mr = 230 000, 220 000, 183 000, 157 000, 125 000, 70 000, 65 000, 62 000, 57 000, 53 000 and 48 000 copurify with the single-stranded----replicative form activity, which sediments at approx. 10 S. The Mr = 183 000, 157 000 and 125 000 polypeptides exhibit catalytic activity when assayed in situ following SDS-polyacrylamide gel electrophoresis. The 10 S form of DNA polymerase alpha is functionally distinguishable from an 8.4 S form of the enzyme obtained from the same cells on the basis of single-stranded----replicative form activity. The single-stranded----replicative form activity of the 10 S enzyme is stable at 22 degrees C for up to 3 h, but exhibits a half life of only 5 min at 45 degrees C.

Microcomputer applications in retinal research

A low cost microcomputer was used to: (1) word process and edit this manuscript, (2) create a patient file storage and retrieval system, (3) transcribe and store information from video display such as wide-angle fundus photographs and fluorescein angiograms, (4) plot data points in graphic display mode, (5) solve complex equations used to calculate intraocular tumor volumes, (6) search medical literature data bases, and (7) directly interface with sophisticated laboratory equipment performing complicated tasks such as multicomponent analysis and enzyme kinetics.