Correlation between thermoluminescence and optically stimulated luminescence responses of natural alexandrite

Luminescent properties of alexandrite crystals (BeAl₂O₄:Cr³⁺) are studied. Partial readouts of thermoluminescence (TL) and optically stimulated luminescence (OSL) signals were obtained to infer the relations of OSL and TL trapping centers. Four TL peaks were studied; their intensities decrease at different rates by illumination with blue OSL light. The OSL curve shows two-time components (exponential decay constants 3.15 and 28.4 s). The short time component is preferentially diminished when the sample is heated to temperatures from 363 to 513 K. About 50% of the whole TL intensity remains after a complete 300s OSL readout.

Inhibition of the Platelet Reaction by a High Molecular Weight Phosphoglycoprotein Isolated from Human Platelet Plasma Membranes

The effect of a phospho-glycoprotein (HMW-GP), obtained from human platelet plasma membranes, on the aggregation and secretion of human platelets was studied. Incubation of PRP with 4 to 16 μg/ml of HMW-GP results in inhibition of ADP-, Epinephrine-, Collagen-, and Thrombin-induced platelet aggregation. The effect is mainly reflected on the secondary wave of aggregation. The inhibitory effect is partially overcome by higher concentration of the inducers, however, even under these conditions, a clear tendency towards disaggregation is observed. 5HT release (Col-induced) is strongly decreased from 50% to 4.5. The inhibitory effect on Thrombin-induced aggregation is markedly dependent on external calcium, being maximal at 5 mM calcium. The HMW-GP does not bind ADP or Thrombin. Membrane conformation is markedly affected, as evidenced by the effect of HMW-GP on the iodination of surface polypeptides of intact platelets. It is suggested that interaction of HMW-GP with the platelet membrane blocks the signal(s) transmission that links stimulus to activation. The inhibition observed might just represent an experimental amplification of the endogenous modulatory function that has been proposed for this high molecular weight phosphoglycoprotein.

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 P2-02-21: The utility and correlation of circulating tumor cells (CTCs) and cell-free circulating tumor DNA (ctDNA) based on HER2 positivity

Background:

CTCs are well-established prognostic and predictive biomarkers for metastatic breast cancer (MBC) and other solid tumors. ctDNA is emerging as a quantitative blood-based biomarker for monitoring genomic alterations and disease progression. We evaluated the clinical utility and correlation of these liquid biopsy molecular tools in a cohort of MBC patients.

Methods:

CTC samples were obtained from an ongoing, prospective study of blood based prognostic biomarkers for breast cancer patients. At this time, 71 patients and 98 total samples have been collected. CTC enumeration was performed using the CellSearchTM platform (Menarini, IT). Within this cohort, MBC patients who had ctDNA testing were identified. ctDNA testing was performed using Guardant360TM (Guardant Health, CA), a digital next-generation sequencing technology. Two groups were analyzed: (1) HER2-negative patients with CTC ≥ 5 in 7.5 ml of blood (2) HER2-positive patients who had been treated with HER2 targeted therapy.

Results:

22 samples (N=16 patients) were found with CTC ≥ 5 (range 8-904) and concurrent ctDNA testing (median timeframe between collection 0 days, range 0-42 days). There was a significant association between number of CTCs and the total number of genomic alterations detected in ctDNA (paired two sample t-test, p=0.012). In addition, CTC enumeration was significantly correlated with somatic alteration burden of the dominant clone (paired two sample t-test, p=0.023). The most common alterations detected in the blood were TP53 (55% of patients, 18 total mutations), PIK3CA (41% of patients, 15 total mutations), and ESR1 (32% of patients, 14 total mutations). For patients with HER2 positivity receiving HER2-targeted therapies (N=16 samples from 11 patients), only 18.8% of samples had detectable CTCs (all less than 5) as compared to 75.0% of samples with detectable ctDNA alterations. In N=12 samples with detectable ctDNA mutations, mean number of genomic alterations was 4.4 with mean somatic mutation burden of 2.95%.

 CTCs detectedctDNA detectedCTC ≥ 5Mean number of ctDNA alterations+Mean somatic alteration burden+HER2- (only cases with CTC ≥ 5)100% (22/22)100% (22/22)100%6.716.1%HER2+ (all cases)18.8% (3/16)75.0% (12/16)0%4.42.95%+excludes ctDNA samples without detected genomic alterations

Conclusions:

In HER2-negative MBC patients, CTC enumeration was significantly correlated with the number of ctDNA genomic alterations and somatic alteration burden, indicating the potential for ctDNA as a prognostic, quantitative biomarker of tumor burden. In patients with HER2 positivity, ctDNA may be a more sensitive liquid biopsy tool given the rarity of detecting CTCs detection in this population using the CellSearchTM system. In HER2-positive patients, consideration of size-dependent selection of CTCs using filtration of cells that have undergone epithelial-mesenchymal transition may improve detection in this subgroup.

Citation Format: Davis AA, Zhang Y, Behdad A, Taxter T, Strickland K, Santa-Maria C, Flaum L, Cruz MR, Platanias LC, Gradishar WJ, Cristofanilli M. The utility and correlation of circulating tumor cells (CTCs) and cell-free circulating tumor DNA (ctDNA) based on HER2 positivity [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 P2-02-21.

Abstract GS6-05: Gain-of-function kinase library screen identifies FGFR1 amplification as a mechanism of resistance to antiestrogens and CDK4/6 inhibitors in ER+ breast cancer

Background: CDK4/6 inhibitors have been approved in combination with endocrine therapy for treatment of ER+ metastatic breast cancer. The goal of this study was to discover mechanisms of resistance to ER antagonists alone and in combination with CDK4/6 inhibitors.

Results: To achieve this goal, we used lentiviral vectors to individually express 559 human kinase open reading frames (ORFs) in ER+ MCF7 human breast cancer cells treated with fulvestrant ± the CDK4/6 inhibitor ribociclib. In MCF7 cells treated with fulvestrant alone or with ribociclib, we identified 15 and 17 kinases associated with resistance, respectively. Ten of these kinases overlapped in both groups. In a secondary screen, MCF7 cells were stably transduced with V5-tagged lentiviruses expressing the positive 'hits' for treatment with fulvestrant/ribociclib. Five of 17 kinases (FGFR1, FRK, HCK, FGR, CRKL) were confirmed to induce resistance to fulvestrant/palbociclib and fulvestrant/ribociblib. Survey of TCGA for copy number alterations and/or expression of these 5 genes showed only FGFR1 to be amplified/overexpressed in ˜15% of ER+ breast cancers. Experiments in vitro showed that ER+/FGFR1-amplified (amp) MDA-134, CAMA-1 and HCC1500 human breast cancer cells and MCF7 cells stably transduced with FGFR1 were relatively resistant to estrogen deprivation, fulvestrant and fulvestrant/palbociclib compared to non-FGFR1 amp MCF7 cells. This resistance was abrogated by treatment with the FGFR tyrosine kinase inhibitor (TKI) lucitanib. Treatment with fulvestrant or palbociclib alone modestly delayed growth of ER+/FGFR1-amp breast cancer patient-derived xenografts (PDX) established in nude mice. However, addition of the FGFR TKI erdafitinib to fulvestrant/palbociclib resulted in marked PDX regression in all mice without associated toxicity and a complete cell cycle arrest measured by Ki67. Treatment of FGFR-amp cells with FGF-2 strongly induced CCND1 (cyclin D1) expression. Downregulation of CCND1 with CCND1 RNAi oligonucleotides restored sensitivity of FGFR1-amp cells to fulvestrant/palbociclib, thus phenocopying the effect of FGFR TKIs. Conversely, overexpression of CCND1 in MCF7 cells induced resistance to estrogen deprivation and to fulvestrant ± palbociclib. Finally, we examined next gen sequencing of cell free tumor DNA by Guardant360 in 34 patients before and after progression on CDK4/6 inhibitor. In 10/34 (29%) post-progression specimens, we detected alterations in the FGFR pathway: FGFR1 amplification (n=7), FGFR1 N546K (n=1), FGFR2 N549K (n=1), and FGFR2 V395D (n=1) activating mutations.

Conclusions: These data suggest aberrant FGFR signaling is a mechanism of resistance to anti-ER therapies ± CDK4/6 inhibitors. We posit overexpression of cyclin D1 induced by both FGFR signaling and ER transcription plays a role in drug resistance. Based on these findings we propose ER+/FGFR1 amplified breast cancers are endocrine resistant and should be candidates for treatment with combinations of ER and FGFR antagonists. Accordingly, we have initiated a phase Ib trial of fulvestrant, palbociclib and erdafitinib in patients with antiestrogen resistant ER+/HER2-negative breast cancer with FGFR1-4 amplification.

Citation Format: Formisano L, Lu Y, Jansen VM, Bauer JA, Hanker A, Gonzalez Ericsson P, Lee K-M, Nixon MJ, Guerrero-Zotano AL, Schwarz LJ, Sanders M, Sudhan D, Dugger TC, Cruz MR, Behdad A, Cristofanilli M, Bardia A, O'Shaughnessy J, Mayer IA, Arteaga CL. Gain-of-function kinase library screen identifies FGFR1 amplification as a mechanism of resistance to antiestrogens and CDK4/6 inhibitors in ER+ breast cancer [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 GS6-05.

Timing of adjuvant chemotherapy in colorectal cancer

AIM

Delay in commencing adjuvant therapy for colorectal cancer seems to impair survival in some retrospective studies. This study was planned to evaluate its impact on survival.

METHODS

This was a retrospective study enrolling patients registered from 2000 to 2012 in two large cancer-dedicated institutions in Brazil. The primary outcome was overall survival according to early vs late chemotherapy initiation. The interval between the primary surgery and the start of adjuvant chemotherapy was calculated. Survival was estimated using the Kaplan-Meier method and the impact of multiple prognostic factors on survival by Cox regression analysis.

RESULTS

By the end of 2012, a total of 1963 Stage II and III colorectal patients were identified and 1318 patients received adjuvant chemotherapy, with 22% and 46% of those starting adjuvant chemotherapy within 6 weeks and 8 weeks of surgery. The median period of follow-up was 41 months. Patients starting chemotherapy within 6-8 weeks of surgery had longer overall survival compared with those who started after (6 weeks vs later, hazard ratio 0.76, 95% CI 0.57-0.99, P = 0.046; 8 weeks vs later, hazard ratio 0.74, 95% CI 0.59-0.93, P = 0.011). In the multivariate analysis, age, stage, histological grade, angiolymphatic invasion, emergency surgery and preoperative therapy were independent prognostic factors, but the interval between surgery and start of adjuvant therapy was not.

CONCLUSION

In this large retrospective study, the standard prognostic factors impacted on survival whereas the timing of adjuvant therapy did not. Patients with delayed adjuvant chemotherapy may have worse prognostic factors which could play a major role in their poor outcome.

Chemotherapy for advanced non-small cell lung cancer in the elderly population

BACKGROUND

Approximately 50% of patients with newly diagnosed non-small cell lung cancer (NSCLC) are over 70 years of age at diagnosis. Despite this fact, these patients are underrepresented in randomized controlled trials (RCTs). As a consequence, the most appropriate regimens for these patients are controversial, and the role of single-agent or combination therapy is unclear. In this setting, a critical systematic review of RCTs in this group of patients is warranted.

OBJECTIVES

To assess the effectiveness and safety of different cytotoxic chemotherapy regimens for previously untreated elderly patients with advanced (stage IIIB and IV) NSCLC. To also assess the impact of cytotoxic chemotherapy on quality of life.

SEARCH METHODS

We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 10), MEDLINE (1966 to 31 October 2014), EMBASE (1974 to 31 October 2014), and Latin American Caribbean Health Sciences Literature (LILACS) (1982 to 31 October 2014). In addition, we handsearched the proceedings of major conferences, reference lists from relevant resources, and the ClinicalTrial.gov database.

SELECTION CRITERIA

We included only RCTs that compared non-platinum single-agent therapy versus non-platinum combination therapy, or non-platinum therapy versus platinum combination therapy in patients over 70 years of age with advanced NSCLC. We allowed inclusion of RCTs specifically designed for the elderly population and those designed for elderly subgroup analyses.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed search results, and a third review author resolved disagreements. We analyzed the following endpoints: overall survival (OS), one-year survival rate (1yOS), progression-free survival (PFS), objective response rate (ORR), major adverse events, and quality of life (QoL).

MAIN RESULTS

We included 51 trials in the review: non-platinum single-agent therapy versus non-platinum combination therapy (seven trials) and non-platinum combination therapy versus platinum combination therapy (44 trials). Non-platinum single-agent versus non-platinum combination therapy Low-quality evidence suggests that these treatments have similar effects on overall survival (hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.72 to 1.17; participants = 1062; five RCTs), 1yOS (risk ratio (RR) 0.88, 95% CI 0.73 to 1.07; participants = 992; four RCTs), and PFS (HR 0.94, 95% CI 0.83 to 1.07; participants = 942; four RCTs). Non-platinum combination therapy may better improve ORR compared with non-platinum single-agent therapy (RR 1.79, 95% CI 1.41 to 2.26; participants = 1014; five RCTs; low-quality evidence).Differences in effects on major adverse events between treatment groups were as follows: anemia: RR 1.10, 95% 0.53 to 2.31; participants = 983; four RCTs; very low-quality evidence; neutropenia: RR 1.26, 95% CI 0.96 to 1.65; participants = 983; four RCTs; low-quality evidence; and thrombocytopenia: RR 1.45, 95% CI 0.73 to 2.89; participants = 914; three RCTs; very low-quality evidence. Only two RCTs assessed quality of life; however, we were unable to perform a meta-analysis because of the paucity of available data. Non-platinum therapy versus platinum combination therapy Platinum combination therapy probably improves OS (HR 0.76, 95% CI 0.69 to 0.85; participants = 1705; 13 RCTs; moderate-quality evidence), 1yOS (RR 0.89, 95% CI 0.82 to 0.96; participants = 813; 13 RCTs; moderate-quality evidence), and ORR (RR 1.57, 95% CI 1.32 to 1.85; participants = 1432; 11 RCTs; moderate-quality evidence) compared with non-platinum therapies. Platinum combination therapy may also improve PFS, although our confidence in this finding is limited because the quality of evidence was low (HR 0.76, 95% CI 0.61 to 0.93; participants = 1273; nine RCTs).Effects on major adverse events between treatment groups were as follows: anemia: RR 2.53, 95% CI 1.70 to 3.76; participants = 1437; 11 RCTs; low-quality evidence; thrombocytopenia: RR 3.59, 95% CI 2.22 to 5.82; participants = 1260; nine RCTs; low-quality evidence; fatigue: RR 1.56, 95% CI 1.02 to 2.38; participants = 1150; seven RCTs; emesis: RR 3.64, 95% CI 1.82 to 7.29; participants = 1193; eight RCTs; and peripheral neuropathy: RR 7.02, 95% CI 2.42 to 20.41; participants = 776; five RCTs; low-quality evidence. Only five RCTs assessed QoL; however, we were unable to perform a meta-analysis because of the paucity of available data.

AUTHORS' CONCLUSIONS

In people over the age of 70 with advanced NSCLC who do not have significant co-morbidities, increased survival with platinum combination therapy needs to be balanced against higher risk of major adverse events when compared with non-platinum therapy. For people who are not suitable candidates for platinum treatment, we have found low-quality evidence suggesting that non-platinum combination and single-agent therapy regimens have similar effects on survival. We are uncertain as to the comparability of their adverse event profiles. Additional evidence on quality of life gathered from additional studies is needed to help inform decision making.

Transcriptome characterization of the dimorphic and pathogenic fungus Paracoccidioides brasiliensis by EST analysis

Paracoccidioides brasiliensis is a pathogenic fungus that undergoes a temperature-dependent cell morphology change from mycelium (22 degrees C) to yeast (36 degrees C). It is assumed that this morphological transition correlates with the infection of the human host. Our goal was to identify genes expressed in the mycelium (M) and yeast (Y) forms by EST sequencing in order to generate a partial map of the fungus transcriptome. Individual EST sequences were clustered by the CAP3 program and annotated using Blastx similarity analysis and InterPro Scan. Three different databases, GenBank nr, COG (clusters of orthologous groups) and GO (gene ontology) were used for annotation. A total of 3,938 (Y = 1,654 and M = 2,274) ESTs were sequenced and clustered into 597 contigs and 1,563 singlets, making up a total of 2,160 genes, which possibly represent one-quarter of the complete gene repertoire in P. brasiliensis. From this total, 1,040 were successfully annotated and 894 could be classified in 18 functional COG categories as follows: cellular metabolism (44%); information storage and processing (25%); cellular processes-cell division, posttranslational modifications, among others (19%); and genes of unknown functions (12%). Computer analysis enabled us to identify some genes potentially involved in the dimorphic transition and drug resistance. Furthermore, computer subtraction analysis revealed several genes possibly expressed in stage-specific forms of P. brasiliensis. Further analysis of these genes may provide new insights into the pathology and differentiation of P. brasiliensis.

Suspected side effects of a herbicide on dung beetle populations (Coleoptera: Scarabaeidae)

This paper addresses the association between use of a herbicide and anecdotal reports of reduced dung degradation and dung beetle populations. Dung beetles were monthly collected at two adjacent ranches in Mexico. Ranches were similar in area, elevation, exposition, soil, and vegetation, but differed in weed control. Ranch A controlled weeds manually, and ranch B controlled unwanted vegetation with applications of the herbicide Tordon 101M. The main species recovered on each ranch (Ataenius apicalis) was significantly more abundant at ranch A than at ranch B. Conversely, similar numbers of a second species, Ataenius sculptor, were recovered from both ranches. Three lines of evidence support the tentative conclusion that herbicide applications may be causing a decline in populations of A. apicalis on ranch B. First, the greatest reductions of A. apicalis were observed during periods of herbicide application. Second, A. sculptor, apparently little affected by these same herbicide applications, is active primarily during months without herbicide applications. Third, preliminary results of laboratory studies show that exposure to herbicide can impair reproductive function of the dung beetle Canthon cyanellus.

Fertility ratio in male rats: effects after denervation of two pelvic floor muscles

Fertility ratio is defined here as the proportion of females that a male can impregnate after a constant period of in-polygyny living. This ratio was investigated in male rats after denervation of two pelvic floor muscles, the pubococcygeus and iliococcygeus. Denervation was carried out by transecting the somatomotor branch of the pelvic nerve. The lesion did not modify the sexual behavior of males or their overall fertility, but decreased the weight of the ejaculated seminal plug. Consequently, the number of days living in cohabitation to induce pregnancy was increased in lesioned males (approximately 13 days) compared with intact and sham animals (approximately 5 days). These results showed that the fertility ratio was optimal when intact/sham males cohabited with females for two consecutive estrous cycles, but that lesioned males needed up to four cycles to induce most pregnancies. Two hypotheses are raised by our results. The first is that pelvic floor denervation decreases the forceful tension required to expel the semen from the prostatic urethra to the vagina, then an incomplete seminal plug is expelled. The second is that denervation cut afferent fibers that reflexively promote the continence of the semen deposited in the prostatic urethra during seminal emission, allowing some to leak out before ejaculation. The latter hypothesis can also explain the recovery of the fertility ratio in lesioned males. It could be a compensatory mechanism mediated by the pudendal nerve supply to the coccygeus muscle, the other pelvic floor muscle.

Spinal organization and steroid sensitivity of motoneurons innervating the pubococcygeus muscle in the male rat

Male rat motoneurons innervating the pubococcygeus muscle were located in the ventral nucleus of lamina IX at the sixth lumbar (L6) and first sacral (S1) spinal cord segments. Retrograde labeling with horseradish peroxidase-wheat germ agglutinin was transported up to second-order dendrites and revealed that these motoneurons have a "U-shaped arborization" of dendrites toward the intermediolateral and intermediomedial nuclei area of lamina VII. This dendritic organization makes a wide "final common path" that probably integrates afferent information from several sources, accounting for the participation of the pubococcygeus muscle in autonomic and somatic processes, such as those related to micturition and reproduction. Castration produced a decrement in the morphometry of these motoneurons. A main effect was a decrement in dendritic length. Steroid replacement indicated that testosterone and estradiol, but not dihydrotestosterone, are able to induce a recovery of morphometric alterations. However, estrogen induced recovery after 2 weeks of treatment, whereas testosterone took 4 weeks. Thus, it is proposed that supraspinal aromatization of testosterone in the male central nervous system might be an important process for the appropriate organization of the pubococcygeus muscle motoneurons and that estradiol seems to need a shorter time of action than testosterone because of differential up-regulation and down-regulation of steroid receptors.

Regulation of noncontact erection in rats by gonadal steroids

Male rats exhibit erections in the presence of inaccessible estrous females, and we investigated which gonadal steroids regulate these noncontact erections (NCEs). Sexually experienced Wistar males (n >/= 8/group) were tested for NCE four times (every 3 days) before castration, after castration, and after receiving subcutaneous implants of 10-mm Silastic capsules that were empty or filled with crystalline testosterone propionate (TP), dihydrotestosterone (DHT), estradiol benzoate (EB), or DHT + EB (10 mm each). Before castration, males responded with NCE in approximately 50% of tests. No males had NCEs after castration, beginning 3 days after surgery. Also, no males responded after treatment with EB or empty capsules. After receiving implants of TP, DHT, or DHT + EB, 50% of males had NCEs, beginning with the first test 3 days after treatment. On every measure of NCE, males treated with DHT or DHT + EB were indistinguishable from each other and from TP-treated males. Among the sexual responses of male rats, NCE appears to be more sensitive than other behaviors to changes in gonadal condition. In its profile of response to gonadal steroids (testosterone+, dihydrotestosterone+, estradiol-), NCE is similar to reflexive erection, for which spinal systems are sufficient, and unlike copulation (T+, DHT-, E+), which depends on discrete areas of the brain. We nonetheless conclude that NCE depends on androgen-sensitive systems in the brain, but androgen-sensitive neurons in the lumbosacral spinal cord may also play a role.

Peripheral nerves mediating penile erection in the rat

We examined the effects in male rats of bilateral transection of two nerves previously implicated in erectile function, the viscerocutaneous branch of the pelvic nerve (Vc) and the hypogastric nerve (HgN). In Experiment 1 (conducted in Storrs), males underwent simultaneous or successive section of Vc and HgN and were tested for copulation, reflexive erection, and noncontact erection (NCE), i.e. in response to remote cues from estrous females. NCE is considered to be analogous to 'psychogenic' erection in humans, for which the HgN has been ascribed a significant role. In all three types of test, males had a moderate to severe deficit in erectile function after Vc transection. Section of HgN alone had no apparent pro- or anti-erectile effect in any context, nor did it affect the decrement resulting from Vc surgery. Regardless of treatment, all groups retained some erectile potential in each type of test. The loss of bladder function after Vc surgery and of seminal plug deposition after HgN section gave evidence that the targeted nerves were in fact severed. In Experiment 2 (conducted in Xalapa), males were tested only for NCE, but (a) they were tested every 3 days beginning 3 days after each surgery, (b) the interval between the two surgeries was more than 2 weeks, rather than 1 week as in Experiment 1, to allow more time for recovery from general effects of surgery and for hypothetical plasticity of neural function. In the first test after the first surgery, all groups had a modest reduction in the proportion of males displaying NCE, relative to sham-operated males. However, this deficit did not extend to measures of NCE latency or number, and was absent after the second test. After the second surgery, when all males except those with sham operations had both nerves cut, none of the groups exhibited a significant deficit in NCE, and all groups had at least one test in which at least half the males responded. Thus, (a) HgN section did not significantly impair NCE, reflexive erection, or copulation; (b) Vc section impaired, but did not eliminate, erection in all three contexts, but even those effects may be transient; and (c) transection of both nerves, simultaneously or successively, did not cause a greater impairment in erection than did cutting just the Vc. We infer that the HgN may have no pro-erectile role in erection in rats, even in a model analogous to psychogenic erection. The Vc is probably the most important nerve mediating pro-erectile function in NCE, as in reflexive erection and copulation, but this nerve may not be essential for erection in rats in any context, at least in some males.

alpha 1-Antitrypsin- and anchorage-independent growth of MCF-7 breast cancer cells

alpha 1-Antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-ACHY) are closely related protease inhibitors, synthesized primarily by the liver, which play major roles in modulation of the inflammatory response. Previously, we had shown that MCF-7 human breast cancer cells were able to synthesize active alpha 1-AT and alpha 1-ACHY and that the synthesis of both inhibitors varied among different MCF-7 sublines. We now show that when MCF-7(ML) cells (a subline synthesizing low levels of alpha 1-AT) are grown in soft agar in medium depleted of its trypsin inhibitory capacity (i.e. alpha 1-AT-free), addition of alpha 1-AT (50 micrograms/ml) significantly reduces colony formation in both the presence and absence of estradiol (34% and 44%, respectively). Under these conditions, incubation with 10(-7) M estradiol alone increased colony formation 2- to 3-fold. Colony formation was also significantly reduced by serum leukocyte protease inhibitor, which, like alpha 1-AT, is a potent inhibitor of elastase-like enzymes. We also found that a variety of inflammatory mediators, cytokines, and steroid hormones are able to stimulate synthesis of alpha 1-AT and alpha 1-ACHY by MCF-7 cells. Stimulation by interleukin-6 (IL-6; 200 U/ml), epidermal growth factor (4 nM), and estradiol (10(-7) M) was 2- to 3-fold, whereas stimulations by tetradecanoylphorbol-13-acetate (TPA; 80 nM) and IL-1 (10 U/ml) were 2- to 5-fold and 5- to 10-fold, respectively. In each instance, protein synthesis, monitored by immunoprecipitation of 35S-labeled proteins followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and steady state mRNA levels, monitored by Northern blot analysis with specific cDNA probes, increased to the same extent. Consistent with their ability to stimulate alpha 1-AT synthesis, TPA and IL-1 reduced colony formation in the absence of estradiol by 65% and 63%, respectively. In addition, the effects of both TPA and IL-1 could be reversed by antibody to alpha 1-AT. These results suggest that local synthesis of alpha 1-AT and possibly other protease inhibitors may be important in regulating the tumorigenic potential of MCF-7 breast cancer cells.

Synthesis of alpha 1-antichymotrypsin and alpha 1-antitrypsin by human trophoblast

alpha 1-Antichymotrypsin (alpha 1-ACHY) and alpha 1-antitrypsin (alpha 1-AT) are closely related glycoprotein protease inhibitors, present in plasma and other extracellular fluids, that neutralize proteases released by leukocytes in response to trauma and inflammatory stimuli. Both inhibitors are synthesized primarily by hepatocytes, although lower levels of synthesis by monocytes and breast and intestinal epithelial cells have been demonstrated. Recently, the immunohistochemical localization of alpha 1-AT and alpha 1-ACHY in intrauterine and extrauterine human trophoblastic tissue has been reported. In the present study, we have sought to determine whether human trophoblast is also able to synthesize alpha 1-AT and alpha 1-ACHY. Messenger RNA for both inhibitors was found by Northern blotting in chorionic villi obtained from first trimester and term placenta. Substantial differences in messenger levels for both inhibitors among individual placentas were noted. alpha 1-ACHY and alpha 1-AT messenger was also present in trophoblast cells in primary culture. Synthesis of alpha 1-AT and alpha 1-ACHY protein was demonstrated by SDS-PAGE after immunoprecipitation of [35S]-labeled alpha 1-AT and alpha 1-ACHY from conditioned media of trophoblast cells in culture metabolically labeled with [35S]-methionine. It is of some interest that the M(r) of the alpha 1-AT and alpha 1-ACHY secreted by trophoblast were 50,000 and 49,000, respectively, compared with 54,000 and 68,000 for these proteins in plasma (or secreted by HepG2 human hepatoma and MCF-7 human breast cancer cells).(ABSTRACT TRUNCATED AT 250 WORDS)

The storage pool deficiency in platelets from humans with the Chédiak-Higashi syndrome: study of six patients

Functional and biochemical studies of platelets from human Chédiak-Higashi syndrome (CHS) are scarce and/or incomplete. In the present report, the aggregation response to a variety of inducers of platelet aggregation, the content of the dense granule constituents ATP, ADP, serotonin and calcium, the secretion of ATP, ADP, and calcium induced by thrombin, the total content of magnesium, the incorporation of 14C-adenine in the cytoplasmic pool of adenine nucleotides, as well as the content of intracellular cyclic-AMP, have been quantitated in six patients with CHS. Furthermore, data is presented on the kinetics of uptake of radiolabelled serotonin and its storage in human CHS platelets. An abnormal aggregation behaviour was found in all patients. However, the response of CHS platelets to the different inducers studied did not show a uniform pattern. The total content and the maximal amounts of the dense granule constituents secretable by thrombin were greatly decreased in all six patients. Total magnesium content was similar to that of normal platelets. The ATP/ADP ratio was higher than in controls. Uptake of radiolabelled serotonin by CHS platelets closely followed the uptake by normal platelets; during the first 2-3 min, however, incorporation of the amine by CHS platelets came rapidly to a plateau which contrasts with the steady, linear increase in uptake found in controls. CHS platelets loaded with radiolabelled serotonin and gel-filtered, showed a spontaneous release of radioactivity not observed in normal platelets under the same conditions. The cyclic-AMP content of CHS platelets was similar to that of normals. In contrast to platelets from patients with storage pool disease, the secretable calcium from CHS platelets represents a 67% of total platelet calcium (61% in normals), suggesting that the absolute values for the non-secretable portion in CHS platelets must be very low. The results reported confirm the existence of a true storage pool deficiency of the dense granule constituents as a common defect in CHS platelets. The variety of responses among patients, to the different aggregatory stimuli studied, can not be solely ascribed to the storage pool deficiency described.

Effects of garlic extract and of three pure components isolated from it on human platelet aggregation, arachidonate metabolism, release reaction and platelet ultrastructure

We studied the effect of the methanol extract of garlic bulbs (EOG) and of three pure components isolated from it (F1, F2, F3), on human platelet aggregation induced by ADP, epinephrine, collagen, thrombin, arachidonate, PAF, and the ionophore A-23187. Incubation of PRP with EOG, either in methanol or in homologous PPP, inhibits platelet aggregation induced by all of the above mentioned agonists. F1, F2, and F3 also inhibit platelet aggregation, however, F3 was about four times more potent. Addition of EOG or F3 to platelets that have already been irreversibly aggregated by 10 microM ADP, induces rapid deaggregation. Inhibition of aggregation was still present after three hours. The inhibitory effect persisted even after the treated platelets were Gel-Filtered (GFP) or separated from plasma through a metrizamide gradient and resuspended in new homologous PPP. Thrombin-induced release of ATP from GFP was inhibited by 75-80% after EOG or F3 treatment. Incorporation of [3-H]-arachidonate by intact platelets was decreased by 50-60% in treated platelets. However, platelets incubated with the inhibitors after incorporation of radiolabeled arachidonate, although did not aggregate, produced, after thrombin activation similar amounts of radiolabeled TXB2 and lipoxygenase products as the controls. Electron microscopy of inhibited platelets, in the presence of thrombin, showed no degranulation but an increase of spherical forms. Our results suggest that the effects described might be mediate by a perturbation of the physicochemical properties of the plasma membrane rather than by affecting arachidonate or calcium metabolism in the cells. Chemical structures of F1, F2 and F3 have been provisionally assigned: F1 is diallytrisulfide, F2 is 2-vinyl-1,3-dithiene, and F3 is most probably allyl 1,5-hexadienyltrisulfide.

The phospholipase A2 from human platelets

Studies on a purified phospholipase A2 (PLA2) from human platelets show that the enzyme, which is copurified with the plasma membrane fraction, has a MW of approximately 50 K Dalton, requires Ca++, and has a pH optimum of 9.4. Under optimal conditions, PLA2 activity corresponds to at least 13 nmol/min/10(9) platelets. Unsaturated PL are preferred substrates and the enzyme is considerably more active on the aggregated form of the substrate than on the monomers. The specific activity is markedly affected by the quality of the interface, showing variations of more than 10-fold between different substrate forms. In the absence of detergents, a 4-fold increase in rate is observed when both products are present. Maximal rates are obtained at 20 mole percent of products to substrate. 1,2-Diglyceride and phosphatidic acid stimulate the hydrolysis of PC by the purified enzyme, however, in these forms of the substrate, neither of them are hydrolyzed. Activation of this enzyme by some intermediate of the phospholipase C pathway might play a role in the stimulus-linked release of platelet arachidonic acid.

Inhibition of the platelet reaction by a high molecular weight phosphoglycoprotein isolated from human platelet plasma membranes

The effect of phospho-glycoprotein (HMW-GP), obtained from human platelet plasma membranes, on the aggregation and secretion of human platelets was studied. Incubation of PRP with 4 to 16 micrograms/ml of HMW-GP results in inhibition of ADP-, Epinephrine-, Collagen-, and Thrombin-induced platelet aggregation. The effect is mainly reflected on the secondary wave of aggregation. The inhibitory effect is partially overcome by higher concentrations of inducers, however, even under these conditions, a clear tendency towards disaggregation is observed. 5HT release (Col-induced) is strongly decreased from 50% to 4.5. The inhibitory effect on Thrombin-induced aggregation is markedly dependent on external calcium, being maximal at 5 mM calcium. The HMW-GP does not bind ADP or Thrombin. Membrane conformation is markedly affected, as evidenced by the effect of HMW-GP on the iodination of surface polypeptides of intact platelets. It is suggested that interaction of HMW-GP with the platelet membrane blocks the signal(s) transmission that links stimulus to activation. The inhibition observed might just represent an experimental amplification of the endogenous modulatory function that has been proposed for this high molecular weight phosphoglycoprotein.