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Background: Standard chemotherapy remains inadequate in metastatic pancreatic adenocarcinoma. Combining an agonistic CD40 monoclonal antibody with chemotherapy induces T-cell-dependent tumour regression in mice and improves survival. In this study, we aimed to evaluate the safety of combining APX005M (sotigalimab) with gemcitabine plus nab-paclitaxel, with and without nivolumab, in patients with pancreatic adenocarcinoma to establish the recommended phase 2 dose., Methods: This non-randomised, open-label, multicentre, four-cohort, phase 1b study was done at seven academic hospitals in the USA. Eligible patients were adults aged 18 years and older with untreated metastatic pancreatic adenocarcinoma, Eastern Cooperative Oncology Group performance status score of 0-1, and measurable disease by Response Evaluation Criteria in Solid Tumors version 1.1. All patients were treated with 1000 mg/m 2 intravenous gemcitabine and 125 mg/m 2 intravenous nab-paclitaxel. Patients received 0·1 mg/kg intravenous APX005M in cohorts B1 and C1 and 0·3 mg/kg in cohorts B2 and C2. In cohorts C1 and C2, patients also received 240 mg intravenous nivolumab. Primary endpoints comprised incidence of adverse events in all patients who received at least one dose of any study drug, incidence of dose-limiting toxicities (DLTs) in all patients who had a DLT or received at least two doses of gemcitabine plus nab-paclitaxel and one dose of APX005M during cycle 1, and establishing the recommended phase 2 dose of intravenous APX005M. Objective response rate in the DLT-evaluable population was a key secondary endpoint. This trial (PRINCE, PICI0002) is registered with ClinicalTrials.gov, NCT03214250 and is ongoing., Findings: Between Aug 22, 2017, and July 10, 2018, of 42 patients screened, 30 patients were enrolled and received at least one dose of any study drug; 24 were DLT-evaluable with median follow-up 17·8 months (IQR 16·0-19·4; cohort B1 22·0 months [21·4-22·7], cohort B2 18·2 months [17·0-18·9], cohort C1 17·9 months [14·3-19·7], cohort C2 15·9 months [12·7-16·1]). Two DLTs, both febrile neutropenia, were observed, occurring in one patient each for cohorts B2 (grade 3) and C1 (grade 4). The most common grade 3-4 treatment-related adverse events were lymphocyte count decreased (20 [67%]; five in B1, seven in B2, four in C1, four in C2), anaemia (11 [37%]; two in B1, four in B2, four in C1, one in C2), and neutrophil count decreased (nine [30%]; three in B1, three in B2, one in C1, two in C2). 14 (47%) of 30 patients (four each in B1, B2, C1; two in C2) had a treatment-related serious adverse event. The most common serious adverse event was pyrexia (six [20%] of 30; one in B2, three in C1, two in C2). There were two chemotherapy-related deaths due to adverse events: one sepsis in B1 and one septic shock in C1. The recommended phase 2 dose of APX005M was 0·3 mg/kg. Responses were observed in 14 (58%) of 24 DLT-evaluable patients (four each in B1, C1, C2; two in B2)., Interpretation: APX005M and gemcitabine plus nab-paclitaxel, with or without nivolumab, is tolerable in metastatic pancreatic adenocarcinoma and shows clinical activity. If confirmed in later phase trials, this treatment regimen could replace chemotherapy-only standard of care in this population., Funding: Parker Institute for Cancer Immunotherapy, Cancer Research Institute, and Bristol Myers Squibb., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Severe infusion reactions (SIRs) at rates of 5% or less are known side effects of biological agents, including mAbs such as cetuximab. There are currently no prospectively validated risk factors to aid physicians in identifying patients who may be at risk of experiencing an SIR following administration of any of these drugs. A retrospective analysis of 545 banked serum or plasma samples from cancer patients participating in clinical trials of cetuximab was designed to evaluate whether the presence of pretreatment IgE antibodies against cetuximab, as determined by a commercially available assay system, is associated with SIRs during the initial cetuximab infusion. Patients with a positive test indicating the presence of pretreatment antibodies had a higher risk of experiencing an SIR; however, at the prespecified cutoff utilized in this analysis, the test has a relatively low-positive predictive value (0.577 [0.369-0.766]) and a negative predictive value of 0.961 (0.912-0.987) in an unselected patient population. Data collected in this large retrospective validation study support prior observations of an association between the presence of pretreatment IgE antibodies cross-reactive with cetuximab and SIRs. Further analysis of the test's ability to predict patients at risk of an SIR would be required before this assay could be used reliably in this patient population., (© 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Purpose: Retrospective studies have reported that tumor expression of the beta-3 tubulin (β3T) isoform is an unfavorable prognostic factor in non-small-cell lung cancer (NSCLC) treated with tubulin-inhibiting chemotherapy. Ixabepilone is a tubulin-inhibiting agent with low susceptibility to multiple resistance mechanisms including β3T isoform expression in several tumor models. This randomized phase II study evaluated ixabepilone-based chemotherapy in stage IIIb/IV NSCLC, compared with paclitaxel-based chemotherapy. Tumor specimens were prospectively evaluated for β3T expression., Patients and Methods: Patients were stratified by β3T status (positive v negative) and randomly assigned at a ratio of 1:1 to receive ixabepilone (32 mg/m(2)) and carboplatin (area under concentration-time curve [AUC], 6) or paclitaxel (200 mg/m(2)) and carboplatin (AUC, 6) for up to six cycles. The primary end point was progression-free survival (PFS) in the β3T-positive subgroup., Results: Ninety-five patients (β3T positive, 52; β3T negative, 43) received ixabepilone plus carboplatin; 96 patients (β3T positive, 49; β3T negative, 47) received paclitaxel plus carboplatin. No significant differences in median PFS were observed between arms for either subgroup (β3T positive, 4.3 months in both arms; β3T negative, 5.8 v 5.3 months). Ixabepilone did not significantly improve overall survival (OS) for the β3T-positive subset or the overall population. Adverse events were similar between the two arms and comparable with those in previous studies., Conclusion: There was no predictive value of β3T in differentiating clinical activity of ixabepilone- or paclitaxel-containing regimens. Ixabepilone did not improve PFS or OS in patients with β3T-positive tumors. β3T-positive patients had worse PFS relative to β3T-negative patients, regardless of treatment; hence, β3T expression seems to be a negative prognostic factor, but not a predictive factor, in advanced NSCLC treated with either ixabepilone or paclitaxel platinum-based doublets.

Context: The therascreen KRAS RGQ polymerase chain reaction kit is being developed as a companion diagnostic to aid clinicians, through detection of KRAS mutations, in the identification of patients with metastatic colorectal cancer (mCRC) who are more likely to benefit from cetuximab., Objectives: To assess whether KRAS mutation status, determined by using the therascreen KRAS kit, is a predictive marker of cetuximab efficacy., Design: Tissue samples were obtained from patients with mCRC treated on the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) CO.17 phase 3 study of cetuximab plus best supportive care (BSC) versus BSC alone. Tumor DNA samples were assessed for the presence of KRAS mutations by using the therascreen KRAS kit. Efficacy and safety were assessed to determine whether mutation status was predictive of outcomes. Results.-Evaluable samples were available from 453 patients (79.2%) enrolled in the NCIC CTG CO.17 trial. The KRAS wild-type subset represented 54.1% (245 of 453) of the evaluated population. Median overall survival of patients with KRAS wild-type tumors was 8.6 months among those who received cetuximab plus BSC and 5.0 months among patients who received BSC alone (hazard ratio [HR], 0.63; P = .002). Among patients with KRAS mutant mCRC, no meaningful difference in overall survival was observed between arms (HR, 0.91; P = .55). These results are consistent with a previous report that analyzed patient tumor samples by using bidirectional sequencing., Conclusions: These data support the utility of the therascreen KRAS kit as a means of selecting patients who may benefit from cetuximab therapy.

Purpose: Predictive biomarkers offer the potential to improve the benefit:risk ratio of a therapeutic agent. Ixabepilone achieves comparable pathologic complete response (pCR) rates to other active drugs in the neoadjuvant setting. This phase II trial was designed to investigate potential biomarkers that differentiate response to this agent., Experimental Design: Women with untreated, histologically confirmed primary invasive breast adenocarcinoma received neoadjuvant doxorubicin/cyclophosphamide, followed by 1:1 randomization to ixabepilone (n = 148) or paclitaxel (n = 147). Rates of pCR were compared between treatment arms based on predefined biomarker sets: TUBB3, TACC3, and CAPG gene expression, a 20- and 26-gene expression model, MDR1 protein expression, and other potential markers of sensitivity. βIII-tubulin protein expression is reported separately but is referred to here for completeness. All patients underwent a core needle biopsy of the primary cancer for molecular marker analysis before chemotherapy. Gene expression profiling data were used for molecular subtyping., Results: There was no significant difference in the rate of pCR in both treatment arms in βIII-tubulin-positive patients. Higher pCR rates were observed among βIII-tubulin-positive patients than in βIII-tubulin-negative patients. Furthermore, no correlation was evident between TUBB3, TACC3, and CAPG gene expression, MDR1 protein expression, multi-gene expression models, and the efficacy of ixabepilone or paclitaxel, even within the estrogen receptor-negative subset., Conclusion: These results indicate that βIII-tubulin protein and mRNA expression, MDR1 protein expression, TACC3 and CAPG gene expression, and multigene expression models (20- and 26-gene) are not predictive markers for differentiating treatment benefit between ixabepilone and paclitaxel in early-stage breast cancer.

Background: The aim of this phase 2 study was to evaluate the safety and efficacy of ixabepilone plus cetuximab in patients with advanced pancreatic cancer., Methods: Eligible patients had advanced pancreatic adenocarcinoma that was metastatic or not amenable to resection, a Karnofsky performance status ≥70%, and no prior therapy for advanced disease. Patients received ixabepilone 32 mg/m(2) (3-hour IV infusion) every 3 weeks and cetuximab 250 mg/m(2) (1-hour IV infusion) weekly. The primary efficacy end point was the 6-month survival rate. Secondary end points included tumor response rate, overall survival, progression-free survival, and tolerability., Results: A total of 54 patients were enrolled on this study. The 6-month survival rate was 57% (31/54: 95% CI: 43-71%) with a median overall survival of 7.6 months (95% CI: 5.5-12.2 months). Patients who developed acneiform rash (n = 36) had a median survival of 8.8 months, compared with 2.6 months for those without rash (n = 18). Of 31 patients with measurable disease (defined as response-evaluable), 4 had confirmed partial responses and an additional 24 had stable disease. The combination was generally well-tolerated with the most common grade 3/4 hematological toxicities being leucopenia (39%) and neutropenia (33%). The most common grade 3/4 nonhematologic toxicity was fatigue (17%)., Conclusions: The combination of ixabepilone and cetuximab was active and had acceptable toxicity. The efficacy results are similar to single-agent ixabepilone and gemcitabine-based combination therapies in patients with advanced pancreatic cancer. Exploratory analyses suggest a trend toward improved survival for patients who experienced rash.

Dysregulation of enzymes involved in prostaglandin biosynthesis plays a critical role in influencing the biological behavior and clinical outcome of several tumors. In human gliomas, overexpression of cyclooxygenase-2 has been linked to increased aggressiveness and poor prognosis. In contrast, the role of prostaglandin E synthase in influencing the biological behavior of human gliomas has not been established. We report that constitutive expression of the microsomal prostaglandin E synthase-1 (mPGES-1) is associated with increased prostaglandin E(2) (PGE(2)) production and stimulation of growth in the human astroglioma cell line U87-MG compared with human primary astrocytes. Consistently, pharmacologic and genetic inhibition of mPGES-1 activity and expression blocked the release of PGE(2) from U87-MG cells and decreased their proliferation. Conversely, exogenous PGE(2) partially overcame the antiproliferative effects of mPGES-1 inhibition and stimulated U87-MG cell proliferation in the absence of mPGES-1 inhibitors. The EP2/EP4 subtype PGE(2) receptors, which are linked to stimulation of adenylate cyclase, were expressed in U87-MG cells to a greater extent than in human astrocytes. PGE(2) increased cyclic AMP levels and stimulated protein kinase A (PKA) activity in U87-MG cells. Treatment with a selective type II PKA inhibitor decreased PGE(2)-induced U87-MG cell proliferation, whereas a selective type I PKA inhibitor had no effect. Taken together, these results are consistent with the hypothesis that mPGES-1 plays a critical role in promoting astroglioma cell growth via PGE(2)-dependent activation of type II PKA.

Overexpression of human cyclooxygenase 2 (COX-2) in the mammary glands of transgenic mice induces tissue-specific tumorigenic transformation. However, the molecular mechanisms involved are not yet defined. Here we show that COX-2 expressed in the epithelial cell compartment regulates angiogenesis in the stromal tissues of the mammary gland. Microvessel density increased before visible tumor growth and exponentially during tumor progression. Inhibition of prostanoid synthesis with indomethacin strongly decreased microvessel density and inhibited tumor progression. Up-regulation of angiogenic regulatory genes in COX-2 transgenic mammary tissue was also potently inhibited by indomethacin treatment, suggesting that prostanoids released from COX-2-expressing mammary epithelial cells induce angiogenesis. G protein-coupled receptors for the major product, prostaglandin E(2) (PGE(2)) EP(1-4), are expressed during mammary gland development, and EP(1,2,4) receptors were up-regulated in tumor tissue. PGE(2) stimulated the expression angiogenic regulatory genes in mammary tumor cells isolated from COX-2 transgenic mice. Such cells are tumorigenic in nude mice; however, treatment with Celecoxib, a COX-2-specific inhibitor, reduced tumor growth and microvessel density. These results define COX-2-derived PGE(2) as a potent inducer of angiogenic switch during mammary cancer progression.

Prostaglandins have long been known to impact the radiosensitivity of cells and tissues, and many studies have centered on exploiting nonspecific prostaglandin inhibitors such as NSAIDs for therapeutic gain. These studies have ultimately been unsuccessful due to the lack of targeted specificity against the tumor. The discovery of the inducible cyclooxygenase enzyme (COX-2) and development of some highly selective inhibitors (which spare the constitutive COX-1 activity) has renewed excitement for modulating tumor prostaglandins as a method of specific radiosensitization of tumors, while sparing normal tissues. This review discusses these new data and generates a rationale for use of COX-2 inhibitors as radiosensitizing agents in cancer therapy.

Cyclooxygenase (COX)-2 and the prostaglandins resulting from its enzymatic activity have been shown to play a role in modulating cell growth and development of human neoplasia. Evidence includes a direct relationship between COX-2 expression and cancer incidence in humans and animal models, increased tumorigenesis after genetic manipulation of COX-2, and significant anti-tumor properties of non-steroidal anti-inflammatory drugs in animal models and in some human cancers. Recent data showed that COX-2 and the derived prostaglandins are involved in control of cellular growth, apoptosis, and signal through a group of nuclear receptors named peroxisome proliferator-activated receptors (PPARs). In this article we will review some of the findings suggesting that COX-2 is involved in multiple cellular mechanisms that lead to tumorigenesis.

Angiogenesis plays a crucial role in tumor development and growth. The present investigation was undertaken to test the potential involvement of the cyclooxygenase-2 (COX-2) pathway in the regulation of angiogenesis and growth in pancreatic cancer. We compared the angiogenic characteristics of a COX-2-positive human pancreatic tumor cell line, BxPC-3, with those of a COX-2-negative pancreatic tumor cell line, AsPC-1. Cultured BxPC-3 cells promoted a marked increase of endothelial cell migration in comparison with migration that occurred in the absence of cancer cells. Furthermore, BxPC-3 cell culture supernatants induced endothelial cell capillary morphogenesis in vitro and neovascularization in vivo. In contrast, cultured AsPC-1 cells elicited a modest effect on endothelial cell migration and neovascularization in vivo. Pretreatment of BxPC-3 cells with the selective COX-2 inhibitor NS-398 (50 micro M) dramatically decreased angiogenic responses of endothelial cells. NS-398 (25-100 micro M) caused inhibition of BxPC-3 cell proliferation but had no effect on AsPC-1 cell growth. SC-560, a selective COX-1 inhibitor, had no effect on growth of either cell lines. These results suggest an involvement of COX-2 in the control of tumor-dependent angiogenesis and growth in certain pancreatic cancers and provide the rational for inhibition of the COX pathway as an effective therapeutic approach for pancreatic tumors.

Combining anticancer drugs with different mechanisms of action has the potential to enhance antitumor effect. CPT-11 (Camptosar, irinotecan), a topoisomerase I inhibitor, has been shown to be highly effective in the treatment of a variety of cancers. However, its clinical usage is often complicated by late diarrhea. A number of studies have shown that cyclooxygenase (COX)-2 is overexpressed in many forms of human tumors, suggesting that COX-2 inhibition may be useful in the treatment of cancer. In this study, we used two mouse tumor models (HT-29 and colon-26 cells) to evaluate the effect of combining CPT-11 with celecoxib on tumor growth. We also assessed the involvement of COX-2 in the pathogenesis of CPT-11-induced late diarrhea using a rat model. Results indicate that celecoxib enhances the antitumor effect of CPT-11 and reduces the severity of late diarrhea in a dose-dependent manner. The extended benefits of combining celecoxib with CPT-11 may significantly improve the outcome of cancer patients.

The cyclooxygenase (COX)-2 gene encodes an inducible prostaglandin synthase enzyme that is overexpressed in adenocarcinomas and other tumors. Deletion of the murine Cox-2 gene in Min mice reduced the incidence of intestinal tumors, suggesting that it is required for tumorigenesis. However, it is not known if overexpression of Cox-2 is sufficient to induce tumorigenic transformation. We have derived transgenic mice that overexpress the human COX-2 gene in the mammary glands using the murine mammary tumor virus promoter. The human Cox-2 mRNA and protein are expressed in mammary glands of female transgenic mice and were strongly induced during pregnancy and lactation. Female virgin Cox-2 transgenic mice showed precocious lobuloalveolar differentiation and enhanced expression of the beta-casein gene, which was inhibited by the Cox inhibitor indomethacin. Mammary gland involution was delayed in Cox-2 transgenic mice with a decrease in apoptotic index of mammary epithelial cells. Multiparous but not virgin females exhibited a greatly exaggerated incidence of focal mammary gland hyperplasia, dysplasia, and transformation into metastatic tumors. Cox-2-induced tumor tissue expressed reduced levels of the proapoptotic proteins Bax and Bcl-x(L) and an increase in the anti-apoptotic protein Bcl-2, suggesting that decreased apoptosis of mammary epithelial cells contributes to tumorigenesis. These data indicate that enhanced Cox-2 expression is sufficient to induce mammary gland tumorigenesis. Therefore, inhibition of Cox-2 may represent a mechanism-based chemopreventive approach for carcinogenesis.

Overexpression of the cyclooxygenase-2 (COX-2) gene is observed in several neoplastic diseases. However, molecular mechanisms involved in the regulation of expression of COX-2 are not well understood. In this report, we describe a unique post-transcriptional regulatory mechanism of COX-2 mRNA stabilization in MDA-MB-231 cells, a highly metastatic cell line derived from a human mammary tumor. High levels of COX-2 mRNA, protein, and enzyme activity were induced by serum withdrawal, which were potently inhibited by the addition of serum or >100-kDa serum factor. Nuclear run-on analysis and actinomycin D chase experiments indicate that regulation is primarily at the level of post-transcriptional mRNA stability. Interestingly, SB203580, an inhibitor of the p38 stress-activated protein kinase (SAPK), and overexpression of the dominant-negative p38alpha construct potently inhibited the serum withdrawal-induced COX-2 mRNA levels. Indeed, the half-life of COX-2 mRNA decreased from 9 to 4.5 h after SB203580 treatment, suggesting that signal transduction by the p38 SAPK pathway is required for COX-2 mRNA stability.

The immediate-early gene cyclooxygenase 2 (Cox-2) is induced in a variety of hyperplastic pathological conditions, including rheumatoid arthritis and colorectal cancer. Although a causal role for Cox-2 has been proposed, mechanisms by which Cox-2 function contributes to the pathogenesis of hyperplastic disease are not well defined. We constructed a green fluorescent protein-tagged Cox-2 (Cox-2-GFP) to examine its effects on a variety of cell types upon overexpression. Subcellular localization and enzymatic and pharmacological properties of Cox-2-GFP polypeptide were indistinguishable from those of the wild-type Cox-2 polypeptide. Overexpression of the Cox-2-GFP or the Cox-2 polypeptide by transient transfection suppressed the population of cells in the S phase of the cell cycle, with a concomitant increase in G(0)/G(1) population. In contrast, transient overexpression of GFP had no effect on cell cycle distribution, whereas endoplasmic reticulum-retained GFP (GFP-KDEL) overexpression was associated with only a minor decrease of cells in S phase. Interestingly, neither NS-398 (a Cox-2-specific inhibitor) nor indomethacin could reverse the effect of Cox-2-GFP overexpression on cell cycle progression. Furthermore, two mutants of Cox-2, S516Q and S516M, which lack the cyclooxygenase activity, exhibited the same effect as Cox-2-GFP. The cell cycle effect of Cox-2-GFP was observed in ECV-304, NIH 3T3, COS-7, bovine microvascular endothelial cells, and human embryonic kidney 293 cells. These findings suggest that Cox-2 inhibits cell cycle progression in a variety of cell types by a novel mechanism that does not require the synthesis of prostaglandins.

The cyclooxygenase isoenzymes (COX-1 and -2) catalyze the rate-limiting steps in prostanoid biosynthesis. COX-1 and -2 genes encode two isoenzymes with overlapping yet distinct expression patterns and functions. Physiologically, various extracellular stimuli such as growth factors, cytokines and tumor promoters regulate the expression of COX-1 and -2 genes at both transcriptional and post-transcriptional levels. COX-2 is overexpressed in rheumatoid arthritis, colorectal and breast cancer. Prostanoids produced by the COX pathway signal via plasma membrane-localized, G-protein-coupled receptors as well as via nuclear receptors. Currently, several COX-2-selective inhibitors are developed to control the anti-inflammatory and anti-neoplastic activities of the COX-2 isoenzyme. Inhibition of the COX isoenzyme activity and/or expression may be the basis of future generation of anti-inflammatory and anti-neoplastic drugs.

Purpose: Two genes for adult-onset primary open-angle glaucoma have been mapped to chromosomes 2cen-q13 and 3q21-q24. We studied a family with adult-onset primary open-angle glaucoma in which the disease did not map to these two chromosomal regions., Methods: We ascertained a four-generation family with adult-onset primary open-angle glaucoma in which the disease status of individuals was objectively assigned using defined criteria. Complete ophthalmologic examinations, visual field testing, optic nerve head photographs, and venous blood samples were obtained. Family members were genotyped using polymerase chain reaction amplification of microsatellite polymorphic markers. Linkage analysis was performed and lod scores were calculated. Haplotype transmission data were analyzed., Results: A total of 20 subjects in three successive generations agreed to participate in the study. This included samples from eight affected subjects, one glaucoma suspect, one normal individual, and two spouses in generations II and III, and an additional eight individuals in generation IV. The phenotype in this family appears to be variable, with onset of visual field loss in middle age, followed by modest elevation of intraocular pressure and progression of the disease in older individuals. Linkage was established with a group of DNA markers located in the 8q23 region. A lod score value of 3.61 was obtained using marker D8S1471. Three other markers from the same region gave lod score values of over 3.0. Haplotype transmission data identified two recombination events that placed the gene in a 6.3-cM region flanked by D8S1830 and D8S592. The disease-bearing haplotype was inherited by eight affected subjects and three glaucoma suspects., Conclusion: We present evidence for a third adult-onset primary open-angle glaucoma locus (GLC1D) on chromosome 8q23. The genetic heterogeneity of adult-onset glaucoma is evident from the multiplicity of chromosomal loci associated with this disease.

One of the major causes of blindness is primary open-angle glaucoma, which affects millions of elderly people worldwide. Genetic studies have so far mapped three loci for the adult-onset form of this condition to the 2cen-q13, 3q21-q24, and 8q23 regions. Herein, we report the localization of a fourth locus, to the 10p15-p14 region, in one large British family with a classical form of normal-tension open-angle glaucoma. Of the 42 meioses genotyped in this pedigree, 39 subjects (16 affected) inherited a haplotype compatible with their prior clinical designation, whereas the remaining 3 were classified as unknown. Although a maximum LOD score of 10.00 at a recombination fraction of straight theta=.00 was obtained with D10S1216, 21 other markers provided significant values, varying between 3.77 and 9.70. When only the affected meioses of this kindred were analyzed, LOD scores remained statistically significant, ranging from 3.16 (D10S527) to 3.57 (D10S506). Two critical recombinational events in the affected subjects positioned this new locus to a region of approximately 21 cM, flanked by D10S1729 and D10S1664. However, an additional recombination in a 59-year-old unaffected female suggests that this locus resides between D10S585 (or D10S1172) and D10S1664, within a genetic distance of 5-11 cM. However, the latter minimum region must be taken cautiously, because the incomplete penetrance has previously been documented for this group of eye conditions. A partial list of genes that positionally are considered as candidates includes NET1, PRKCT, ITIH2, IL2RA, IL15RA, IT1H2, hGATA3, the mRNA for open reading frame KIAA0019, and the gene for D123 protein.

Recent studies have indicated that repeated brief episodes of ischemia and reperfusion render the myocardium more tolerant to subsequent lethal ischemic injury. In view of the previous observations that ischemia-reperfusion potentiates phospholipase D signaling and that such signaling is beneficial for the heart, we investigated whether a similar phospholipase D signaling is responsible for the beneficial effects associated with repeated ischemia and reperfusion. Using an isolated perfused working rat heart model, we demonstrated that four brief episodes of 5 min of ischemia and 10 min of reperfusion reduced the incidence of ventricular arrhythmias, enhanced the postischemic ventricular performance, and decreased the release of creatine kinase from the reperfused heart, with simultaneous activation of phospholipase D generating the second messengers diacylglycerol and phosphatidic acid and leading to the translocation and activation of protein kinase C. The specific antiphospholipase D antibody blocked the activation of phospholipase D and attenuated the generation of diacylglycerol and phosphatidic acid and activation of protein kinase C. In concert, phospholipase D inhibition increased the incidence of ventricular arrhythmias, blocked the beneficial effects of preconditioning on the ventricular performance, and increased the amount of creatine kinase release from the coronary effluent. The results of this study indicate that repeated brief episodes of ischemia and reperfusion exert beneficial effects on the intact rat heart by triggering the activation of a phospholipase D signaling mechanism.

Primary open angle glaucoma (GLC1) is a common ocular disorder with a characteristic degeneration of the optic nerve and visual field defects that is often associated with an elevated intraocular pressure. The severe but rare juvenile-onset type has previously been mapped to 1q21-q31, and its genetic heterogeneity has been established. Herein, we present a new locus (GLC1B) for one form of GLC1 on chromosome 2cen-q13 with a clinical presentation of low to moderate intraocular pressure, onset in late 40s, and a good response to medical treatment. Two-point and haplotype analyses of affected and unaffected meioses in six families provided maximum linkage information with D2S417, GATA112EO3, D2S113, D2S373, and D2S274 (lod scores ranging from 3.11 to 6.48) within a region of 8.5 cM that is flanked by D2S2161 and D2S2264. Analysis of affected meioses alone revealed no recombination with an additional two markers (D2S2264 and D2S135) in a region of 11.2 cM that is flanked by D2S2161 and D2S176. Analysis of unaffected meioses identified only one healthy 86-year-old male who has inherited the entire affected haplotype and, hence, is a gene carrier for this condition. Eight additional families with similar and/or different clinical presentation did not show any linkage to this region and, therefore, provided evidence for genetic heterogeneity of adult-onset primary open angle glaucoma.

The synthesis and the release of the atrial natriuretic factor (ANF) were studied by electron microscopy in the atrial cells from an ischemic myocardium. The ANF-containing secretory vesicles of normal atrial cells were present in great number near the Golgi apparatus, and near the sarcolemma. After 30 min. of global ischemia the number of ANF-containing secretory vesicles decreased in the atrial cells, suggesting an ANF release during heart ischemia.