Guidelines for cellular and molecular pathology content in clinical trial protocols: the SPIRIT-Path extension

The 2013 SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) Statement provides evidence-based recommendations for the minimum content to be included in a clinical trial protocol. Assessment of biospecimens is often required for trial eligibility or as part of an outcome evaluation, and precision molecular approaches are increasingly used in trial design. However, cellular and molecular pathology practices within trials have not been codified or formalised. We developed international consensus reporting guidelines for cellular and molecular pathology content in clinical trial protocols (the SPIRIT-Path extension) using an international Delphi process, which assesses candidate items generated from a previous systematic review, followed by an expert consensus meeting. 74 individuals from five continents responded, including clinicians, statisticians, laboratory scientists, patient advocates, funders, industry representatives, journal editors, and regulators. The SPIRIT-Path guidelines recommend 14 additional items (seven extensions to the SPIRIT checklist and seven elaborations) that should be addressed in trial protocols containing pathology content, alongside the SPIRIT 2013 Statement items. SPIRIT-Path recommends that protocols should document the individuals, processes, and standards for all cellular and molecular pathology components of the trial, including all stages of the specimen pathway and any digital pathology methods, with specific consideration of the value of trial data and biological tissues for additional translational studies.

O13: TUMOUR STROMAL CELLS - A CULPRIT IN BREAST CANCER RECURRENCE AFTER NEOADJUVANT CHEMOTHERAPY

Introduction

The goal of neoadjuvant chemothepaeutics(NACs) and surgical excision of breast cancer is to control and ultimately eliminate the malignant tumour. Despite advances in treatment, a subset of patients will develop disease recurrence. Tumour stromal cells(TSCs) are non-cancerous cells that support malignancy within the tumour microenvironment(TME). In particular, TSCs can suppress the host immune response to tumour. It is unclear if NACs affect the survival of–or alter the immunosuppressive functions of TSCs in breast cancer patients and if this correlates with recurrance or chemoresistance?

Method

TSCs and Tumour Associated Normal Stromal Cells(TANs) were isolated from tissue harvested from breast cancer patients at surgery. Clonogenic survival assays were performed following exposure to increasing doses of Paclitaxel (range 0-1000nM), Cyclophosphamide (range 0-3μM) and Doxorubicin (0-100nM). TSCs were co-cultured with CD4+ and CD8+ T-cells to determine the effect of chemotherapeutics on their ability to suppress T-cell proliferation.

Result

TSCs(n=5) are less susceptible to the cytotoxic effects of chemotherapy compared to TANs with 21%(p-0.0001), 21%(p-0.001) and 15%(p-0.026) more colonies across all doses of Paclitaxel, Cyclophosphamide and Doxorubicin respectively. Chemo naïve TSCs suppressed CD4+ and CD8+ T-Cell proliferation by 44% and 20.5% respectively(p-0.001, p-0.042). Interestingly, Paclitaxel-treated TSCs suppressed CD4+ proliferation by a further 11.1%(p-0.047) and CD8+ proliferation by 35.6%(p-0.017). Additionally, Cyclophosphamide-treated TSCs enhanced CD8+ suppression by 25.6%(p-0.029).

Conclusion

Our data indicate that NACs enhance the immunosuppressive function of TSCs - potentially creating an immune inert TME in vivo. Future studies will explore the correlation between NAC treatment, immunosuppressive activities within patient tumours/blood and recurrence.

Take-home message

After neoadjuvant chemotherapy, Tumour stromal cells are highly immunosuppressive and may contribute to breast cancer recurrence.

Containment of procedure-associated aerosols by an extractor tent: effect on nebulized drug particle dispersal

Background

Several medical procedures involving the respiratory tract are considered as ‘aerosol-generating procedures’. Aerosols from these procedures may be inhaled by bystanders, and there are consequent concerns regarding the transmission of infection or, specific to nebulized therapy, secondary drug exposure.

Aim

To assess the efficacy of a proprietary high-efficiency-particulate-air-filtering extractor tent on reducing the aerosol dispersal of nebulized bronchodilator drugs.

Methods

The study was conducted in an unoccupied outpatient room at St. James's Hospital, Dublin, Ireland. A novel real-time, fluorescent particle counter, the Wideband Integrated Bioaerosol Sensor (WIBS), monitored room air continuously for 3 h. Baseline airborne particle count and count during nebulization of bronchodilator drug solutions were recorded.

Findings

Nebulization within the tent prevented any increase over background level. Nebulization directly into room air resulted in mean fluorescent particle counts of 4.75 x 10⁵/m³ and 4.21 x 10⁵/m³ for Ventolin and Ipramol, respectively, representing more than 400-fold increases over mean background level. More than 99.3% of drug particles were <2 μm in diameter and therefore small enough to enter the lower respiratory tract.

Conclusion

The extractor tent was completely effective for the prevention of airborne spread of drug particles of respirable size from nebulized therapy. This suggests that extractor tents of this type would be efficacious for the prevention of airborne infection from aerosol-generating procedures during the COVID-19 pandemic.

Effectiveness of a plasma treatment device on microbial air quality in a hospital ward, monitored by culture

This study analysed the effectiveness of plasma treatment on airborne bacteria and surface counts during a 14-day intervention within a four-bedded bay in an adult respiratory ward at Cork University Hospital, Ireland. One-hundred-litre air samples were collected twice daily every weekday for 4 weeks, with settle plates and surface swabs. The plasma treatment did not have an effect on airborne bacteria and fungi that was detectable by culture. However, the possibility that culture-based sampling may be insufficiently sensitive to detect an effect, or that the duration of the study was insufficient for plasma treatment to affect a complex environment, cannot be excluded.

Abstract LB-396: Amplification of the CXCR3/CXCL9 axis via intratumoral electroporation of CXCL9 synergizes with IL-12 gene therapy (TAVO) to elicit robust anti-tumor immunity

Clinical and preclinical studies have demonstrated that plasmid IL-12 (tavokinogene telseplasmid; TAVO) delivered intratumorally via electroporation drives IFN-γ expression and recruits T cells to the tumor microenvironment, ultimately yielding durable systemic T cell responses. Interrogation of longitudinal biomarker data from our IL-12/anti-PD-1 clinical trial has identified that clinical responses are closely tied to intratumoral CXCR3 levels. While all patients had a similar frequency of activated CD8+ T cells in the periphery, responding patients had a significant increase of intratumoral CXCR3 transcripts post-treatment (p=0.03) compared to nonresponding patients (p=0.4), underscoring the clinical relevance of tumor-infiltrating CXCR3+ immune cells. Since the IFN-γ/CXCL9/CXCR3 axis is known to increase sensitivity to anti-PD-1 therapies, we hypothesized that combining intratumoral TAVO with a DNA-encoded locally secreted CXCL9 (cognate ligand for CXCR3) would further augment/restore this axis and ‘license' a robust anti-PD-1 response beyond the treated lesion. An appropriate CXCL9 gradient can productively modulate frequencies of tumor infiltrating tumor-reactive CXCR3+ T cells. We have previously demonstrated that intratumoral electroporation of plasmid IL-12 and CXCL9 elicits a robust antitumor immune response evidenced by increased systemic antigen-specific CD8+ T cells and improved regression of both treated and contralateral CT26 tumors. In the current study, we demonstrate that an enhanced CXCL9 gradient via intratumoral electroporation leads to efficient trafficking of CXCR3+ CD8+ T cells into CT26 tumors. We further explored how DNA-encodable IL-12/CXCL9 can work together to improve checkpoint inhibitor response. We demonstrated that intratumoral TAVO rapidly drives a population of CXCR3+ CD8+ T cells in the lymph node and importantly, depletion of these CXCR3+ immune cells abrogated an IL-12-mediated anti-tumor response. Furthermore, upon electroporation of IL-12 and CXCL9, transcriptomic analysis of the tumor microenvironment revealed an enrichment of genes associated with immune-related pathways (IFN-γ signaling, interleukin signaling, GPCR signaling), antigen presentation machinery, and TCR signaling, indicating that this combination therapy augments anti-tumor immunity. Lastly, leveraging the partially responsive anti-PD-1 CT26 tumor model, we demonstrated that intratumoral electroporation of plasmid IL-12 with CXCL9 significantly improved anti-PD1 response, providing a strong rationale for filing an Investigational New Drug application based on this intratumoral DNA-encodable combination approach.Intratumoral CXCL9 with IL12

Citation Format: Anandaroop Mukhopadhyay, Bianca Nguyen, Jack Y. Lee, Mia Han, Jon Salazar, Reneta Hermiz, Lauren Svenson, Erica Browning, Daniel J. O'Connor, David A. Canton, Daniel Fisher, Joseph Skitzki, Christopher G. Twitty. Amplification of the CXCR3/CXCL9 axis via intratumoral electroporation of CXCL9 synergizes with IL-12 gene therapy (TAVO) to elicit robust anti-tumor immunity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-396.

The important role of the histopathologist in clinical trials: challenges and approaches to tackle them

High-quality histopathology is essential for the success of clinical trials. Histopathologists have a detailed understanding of tumour biology and mechanisms of disease, as well as practical knowledge of optimal tissue handling and logistical service requirements for study delivery, such as biomarker evaluation, tissue acquisition and turnaround times. As such, histopathologist input is essential throughout every stage of research and clinical trials, from concept development and study design to trial delivery, analysis and dissemination of results. Patient recruitment to trials takes place among all healthcare settings, meaning that histopathologists make an invaluable contribution to clinical trials as part of their routine day-to-day work that often goes unrecognised. More complex evaluation of surgical specimens in the neoadjuvant setting and ever-expanding minimum data sets add to the workload of every histopathologist, not just academic pathologists in tertiary centres. This is occurring against a backdrop of increasing workload pressures and a worldwide shortage of histopathologists and biomedical scientists. Providing essential histopathology support for trials at grassroots level requires funding for adequate resources including histopathologist time, education and training, biomedical scientist and administrative support and greater recognition of the contribution made by histopathology. This paper will discuss the many ways in which histopathologists are involved in clinical trials and the challenges faced in meeting the additional demands posed by trial participation and potential ways to address this, with a special emphasis on the UK model and the Cellular-Molecular Pathology Initiative (CM-Path).

Incorporating the patient experience into regulatory decision making in the USA, Europe, and Canada

The clinical development of cancer therapeutics is a global undertaking, and incorporation of the patient experience into the clinical decision-making process is of increasing interest to the international regulatory and health policy community. Disease and treatment-related symptoms and their effect on patient function and health-related quality of life are important outcomes to consider. The identification of methods to scientifically assess, analyse, interpret, and present these clinical outcomes requires sustained international collaboration by multiple stakeholders including patients, clinicians, scientists, and policy makers. Several data sources can be considered to capture the patient experience, including patient-reported outcome (PRO) measures, performance measures, wearable devices, and biosensors, as well as the careful collection and analysis of clinical events and supportive care medications. In this Policy Review, we focus on PRO measures and present the perspectives of three international regulatory scientists to identify areas of common ground regarding opportunities to incorporate rigorous PRO data into the regulatory decision-making process.

Endovascular approaches to the ascending aorta for repair with straight and branched endografts: techniques and for what lesions

Traditionally ascending aortic lesions have been repaired in open fashion: stenotomy, cardiopulmonary bypass, with or without deep hypothermic circulatory arrest. However, a subsegment of patients are deemed too high risk for open intervention. In the advent of endovascular advancement, this subset of patients may be treated with the use of stents (physician made, off-label use), branched stents, through a variety of methods and approaches. Although there are currently no large randomized, prospective studies, success has been seen in smaller case series. This review article addresses the identification of anatomy amenable to endovascular repair for management of type A aortic dissection, pseudoaneurysm, and zone 0 lesions. Different approaches to repair, including transapical, transeptal, femoral, common carotid, and axillary graft insertion are also examined. For endovascular treatment of ascending aortic lesions to grow as a field, devices made specifically for the ascending aorta need to be designed and larger trials are necessary to evaluate the rates of complications, morbidity, and mortality, and graft patency.

To die or not to die: how does p53 decide?

p53 is frequently mutated in cancer and as a result is one of the most intensely studied tumour suppressors. Analysis of the primitive forms of p53 found in Caenorhabditis elegans and Drosophila, alongside studies using transgenic mouse models, indicate that the induction of apoptosis is both the most conserved function of p53 and vital for tumour suppression. p53-mediated apoptosis occurs through a combination of mechanisms which include pathways that are both dependent and independent of alterations in gene expression. In response to genotoxic insult, these pathways probably act together, thereby amplifying the apoptotic signal. However, the picture is complicated because the p53 activity is determined by stress type and individual cellular characteristics. The numerous p53 responsive genes that have been identified also provide further means of controlling the actions of p53. The recent discoveries of proteins that interact with p53 and specifically regulate the ability of p53 to trigger apoptosis have provided further mechanistic insights into the role of p53 in inducing cell death. Understanding the molecular basis of the proapoptotic action of p53 can assist in our quest to reintroduce or reactivate p53 in human tumours.

The biological response of MCF7 breast cancer cells to proteosome inhibition or gamma-radiation is unrelated to the level of p53 induction

The p53 tumour suppressor is stabilised following exposure to genotoxic agents, such as gamma-radiation. Cell responses to p53 stabilisation include induction of apoptosis and/or cell cycle arrest. Several studies have suggested that gamma-radiation stabilises p53 by blocking ubiquitin mediated proteolysis. Here we have compared the biological activities of p53 stabilized following exposure to gamma-radiation or treatment with the proteosome inhibitor N-acetyl-leucinyl-leucinyl-norleucinal (ALLN) in MCF7 cells with wild type p53. Stabilisation of p53 by ALLN was reversible and was not blocked by caffeine. Although ALLN was a more effective p53 stabilising agent than gamma-radiation, ALLN was not as effective at inducing cell cycle arrest/apoptosis as gamma-radiation. Although p53 stabilised by ALLN and gamma-radiation were both able to bind DNA and activate transcription, ALLN did not increase expression of BAX, which is involved in p53-induced apoptosis. Therefore, p53 stabilised by different agents is not always biologically active to the same extent and additional alterations triggered by gamma-radiation may enable p53 to activate a subset of critical target genes, such as BAX, which are required for p53 responses.

iASPP oncoprotein is a key inhibitor of p53 conserved from worm to human

We have previously shown that ASPP1 and ASPP2 are specific activators of p53; one mechanism by which wild-type p53 is tolerated in human breast carcinomas is through loss of ASPP activity. We have further shown that 53BP2, which corresponds to a C-terminal fragment of ASPP2, acts as a dominant negative inhibitor of p53 (ref. 1). Hence, an inhibitory form of ASPP resembling 53BP2 could allow cells to bypass the tumor-suppressor functions of p53 and the ASPP proteins. Here, we characterize such a protein, iASPP (inhibitory member of the ASPP family), encoded by PPP1R13L in humans and ape-1 in Caenorhabditis elegans. iASPP is an evolutionarily conserved inhibitor of p53; inhibition of iASPP by RNA-mediated interference or antisense RNA in C. elegans or human cells, respectively, induces p53-dependent apoptosis. Moreover, iASPP is an oncoprotein that cooperates with Ras, E1A and E7, but not mutant p53, to transform cells in vitro. Increased expression of iASPP also confers resistance to ultraviolet radiation and to cisplatin-induced apoptosis. iASPP expression is upregulated in human breast carcinomas expressing wild-type p53 and normal levels of ASPP. Inhibition of iASPP could provide an important new strategy for treating tumors expressing wild-type p53.

Additive intraocular pressure lowering effect of various medications with latanoprost

PURPOSE

To determine the additive intraocular pressure reduction of various topical glaucoma agents used adjunctively with latanoprost.

DESIGN

Retrospective interventional case series.

METHODS

Retrospective evaluation of 73 eyes of 73 patients with glaucoma and inadequate intraocular pressure control on latanoprost alone. Each patient received adjunctive treatment with an additional glaucoma agent (dorzolamide, brimonidine, timolol, or other beta-blockers) for 1 year.

RESULTS

When added to latanoprost, dorzolamide lowered intraocular pressure an additional 3.9 mm Hg (19.7%, P <.001); beta-blockers further reduced intraocular pressure by 2.0 mm Hg (12.3%, P <.001), and brimonidine further reduced intraocular pressure by 2.0 mm Hg (9.3%, P =.0011). Dorzolamide dosed twice or three times daily was as effective as adjunctive therapy with latanoprost (P =.92).

CONCLUSION

Adjunctive therapy with dorzolamide provided a statistically significant intraocular pressure reduction at 1 year in eyes that were inadequately controlled with latanoprost alone.

Novel function of the cyclin A binding site of E2F in regulating p53-induced apoptosis in response to DNA damage

We demonstrate here that the E2F1 induced by DNA damage can bind to and promote the apoptotic function of p53 via the cyclin A binding site of E2F1. This function of E2F1 does not require its DP-1 binding, DNA binding, or transcriptional activity and is independent of mdm2. All the cyclin A binding E2F family members can interact and cooperate with p53 to induce apoptosis. This suggests a novel role for E2F in regulating apoptosis in response to DNA damage. Cyclin A, but not cyclin E, prevents E2F1 from interacting and cooperating with p53 to induce apoptosis. However, in response to DNA damage, cyclin A levels decrease, with a concomitant increase in E2F1-p53 complex formation. These results suggest that the binding of E2F1 to p53 can specifically stimulate the apoptotic function of p53 in response to DNA damage.

ASPP proteins specifically stimulate the apoptotic function of p53

We identified a family of proteins termed ASPP. ASPP1 is a protein homologous to 53BP2, the C-terminal half of ASPP2. ASPP proteins interact with p53 and specifically enhance p53-induced apoptosis but not cell cycle arrest. Inhibition of endogenous ASPP function suppresses the apoptotic function of endogenous p53 in response to apoptotic stimuli. ASPP enhance the DNA binding and transactivation function of p53 on the promoters of proapoptotic genes in vivo. Two tumor-derived p53 mutants with reduced apoptotic function were defective in cooperating with ASPP in apoptosis induction. The expression of ASPP is frequently downregulated in human breast carcinomas expressing wild-type p53 but not mutant p53. Therefore, ASPP regulate the tumor suppression function of p53 in vivo.

Randomized, controlled study of low-dose 5-fluorouracil in primary trabeculectomy

PURPOSE

To report a randomized clinical trial of postoperative subconjunctival injections of low-dose 5-fluorouracil in patients undergoing primary trabeculectomy.

METHODS

In a prospective, randomized clinical trial, 40 eyes of 40 patients were randomized to the low-dose 5-fluorouracil group and received three subconjunctival injections of 5 mg each over 11 postoperative days, and 40 eyes of 40 patients were randomized to trabeculectomy without 5-fluorouracil.

RESULTS

Mean (+/-SD) preoperative and 1-year postoperative intraocular pressures in the 5-fluorouracil group were 26.9 (+/-9.5) and 15.3 (+/-5.8) mm Hg, respectively. In the control group these were 25.9 (+/-8.1) mm Hg, and 15.8 (+/-5.1) mm Hg, respectively. The patients who received 5-fluorouracil had a mean reduction in intraocular pressure of 11.5 (+/-9.1) mm Hg at a median follow-up of 52.3 weeks. The control group had a mean reduction in intraocular pressure of 10.2 (+/-8.7) mm Hg at a median follow-up of 52.6 weeks. These differences were not statistically significant.

CONCLUSIONS

Three postoperative subconjunctival 5-fluorouracil injections of 5 mg each after trabeculectomy in eyes at low risk for failure had no statistically or clinically significant effect on reduction of intraocular pressure with 1-year follow-up. Enhancement of success in this group of patients may require a larger total dose of 5-fluorouracil.

Proapoptotic p53-interacting protein 53BP2 is induced by UV irradiation but suppressed by p53

p53 is an important mediator of the cellular stress response with roles in cell cycle control, DNA repair, and apoptosis. 53BP2, a p53-interacting protein, enhances p53 transactivation, impedes cell cycle progression, and promotes apoptosis through unknown mechanisms. We now demonstrate that endogenous 53BP2 levels increase following UV irradiation induced DNA damage in a p53-independent manner. In contrast, we found that the presence of a wild-type (but not mutant) p53 gene suppressed 53BP2 steady-state levels in cell lines with defined p53 genotypes. Likewise, expression of a tetracycline-regulated wild-type p53 cDNA in p53-null fibroblasts caused a reduction in 53BP2 protein levels. However, 53BP2 levels were not reduced if the tetracycline-regulated p53 cDNA was expressed after UV damage in these cells. This suggests that UV damage activates cellular factors that can relieve the p53-mediated suppression of 53BP2 protein. To address the physiologic significance of 53BP2 induction, we utilized stable cell lines with a ponasterone A-regulated 53BP2 cDNA. Conditional expression of 53BP2 cDNA lowered the apoptotic threshold and decreased clonogenic survival following UV irradiation. Conversely, attenuation of endogenous 53BP2 induction with an antisense oligonucleotide resulted in enhanced clonogenic survival following UV irradiation. These results demonstrate that 53BP2 is a DNA damage-inducible protein that promotes DNA damage-induced apoptosis. Furthermore, 53BP2 expression is highly regulated and involves both p53-dependent and p53-independent mechanisms. Our data provide new insight into 53BP2 function and open new avenues for investigation into the cellular response to genotoxic stress.

Stress signals induce transcriptionally inactive E2F-1 independently of p53 and Rb

One of the common features of cellular response to stress is cell cycle arrest or apoptosis. E2F is one of the key factors which controls cell cycle progression. Overexpression of E2F-1 can also induce apoptosis. In order to understand the role of E2F-1 in cellular response to stress, we studied the E2F-1 response in various cell lines to different types of stress signals including UV irradiation, cisplatin, etoposide and hypoxia. We showed here that the expression level of E2F-1 can be up regulated by the treatment of DNA damage agents as well as hypoxia. The kinetics of E2F-1 increase was dependent on the types of inducer and was similar to that of p53. However, stress signals can induce E2F-1 expression independently of p53 and Rb. Furthermore, the induced E2F-1 was transcriptionally inactive. All these results suggested that E2F-1 may play a very important role in cellular response to stress and this novel role of E2F-1 is independent of its transactivation function.

Continuing the search for WBGT clothing adjustment factors

The original concept for the heat stress limits adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) was that the threshold for heat stress can be marked by environmental conditions (WBGT) that are adjusted for metabolic rate. The underlying data were based on ordinary work clothes. The Physical Agents Committee promoted clothing adjustment factors within the industrial hygiene community through a revision in the TLVs for heat stress in 1990. As approved, there were adjustment factors for three other clothing ensembles. To extend and further understand adjustment factors, adjustments for commercially available clothing ensembles and prototype ensembles have been examined. The fundamental principle of the assignment of an adjustment factor to an ensemble begins with establishing critical environmental conditions in which test subjects were just able to maintain thermal equilibrium. Four or five subjects for each ensemble walked on a tread-mill inside a climatic chamber under controlled conditions of heat stress. During each test, heart rate and core temperature were continuously monitored. After a physiological steady-state was achieved, temperature and humidity were slowly increased to maintain relative humidity at 20 percent, 50 percent, or 70 percent. Metabolic rate was assessed by measuring the rate of oxygen consumption. Reviewing a trial, the critical conditions were noted as the time when thermal regulatory control was lost (called the inflection point and marked by a steady increase in core temperature). The climatic conditions at the inflection point were used to assign a critical WBGT. A WBGT representative of each ensemble was assigned through a weighted average of different protocols. Clothing adjustment factors representing an equivalent increase in WBGT were computed by noting the difference between the representative WBGT of the cotton work clothes and the other clothing ensembles. The results suggested adjustment factors with reference to ordinary work clothes from the least stress at -2.1 to 5.5 degrees C-WBGT. The adjustment factors were reasonably well predicted by a linear regression based on a computed value for total evaporative resistance (r2 = 0.92).

RB regulates the stability and the apoptotic function of p53 via MDM2

The binding of RB to MDM2 is shown to be essential for RB to overcome both the antiapoptotic function of MDM2 and the MDM2-dependent degradation of p53. The RB-MDM2 interaction does not prevent MDM2 from inhibiting p53-dependent transcription, but the RB-MDM2 complex still binds to p53. Since RB specifically rescues the apoptotic function but not the transcriptional activity of p53 from negative regulation by MDM2, transactivation by wild-type p53 is not required for the apoptotic function of p53. However, an RB-MDM2-p53 trimeric complex is active in p53-mediated transrepression. These data link directly the function of two tumor suppressor proteins and demonstrate a novel role of RB in regulating the apoptotic function of p53.

Physical and functional interactions between p53 and cell cycle co-operating transcription factors, E2F1 and DP1

One way in which wild-type p53 is able to regulate cell cycle progression is thought to be via the induction of its downstream target gene Waf1/CIP1, thus indirectly regulating the transcriptional activity of E2F. The E2F transcription factors are known to be key effectors of the cell cycle. We report here that there is a physical and functional interaction between p53 and two of the components of the E2F transcription factors, E2F1 and DP1. The expression of wild-type p53 can inhibit the transcriptional activity of E2F, and the expression of both E2F1 and DP1 can also downregulate p53-dependent transcription. The transcriptional activity of p53 is known to be inhibited by the direct binding of mdm2, but we demonstrate here that both E2F1 and DP1 can inhibit p53 transcriptional activity independently of mdm2. Detailed studies of protein-protein interactions have provided evidence that E2F1 and its co-operating factor DP1 can complex with p53 both in vitro and in vivo.

Comparisons of methods to detect glaucomatous optic nerve damage

PURPOSE

Various techniques of optic disc and nerve fiber layer evaluation may be used to detect structural glaucomatous damage. The authors compared several qualitative and quantitative methods to determine their relative sensitivities and specificities to detect the presence of glaucomatous visual field loss.

METHODS

Fifty-one healthy eyes, 169 ocular hypertensive eyes with normal visual fields, and 132 glaucomatous eyes with early visual field defects were evaluated with qualitative and quantitative measures of structural damage to the optic nerve and nerve fiber layer. Qualitative evaluations were performed by three experienced masked observers who independently graded stereoscopic color disc and monochromatic nerve fiber layer photographs. Quantitative measurements of disc rim area and nerve fiber layer height were made with digitized image analysis of videographic images. Manual planimetric measurements of disc rim area were made from enlarged prints of stereoscopic optic disc photographs. Diagnostic precision was defined as the total proportion of correct diagnoses for the presence or absence of visual field loss.

RESULTS

The diagnostic precision of results of a quantitative disc examination (81%) was greater than those of a qualitative nerve fiber layer examination (75%). Quantitative nerve fiber height measurement had the highest sensitivity rate (73%) and results of the qualitative disc examination had the highest specificity rate (87%) of the methods tested.

CONCLUSION

The diagnostic precision of disc evaluation was superior to other methods, including nerve fiber layer examination, in correctly determining the presence of structural glaucomatous damage at the early visual field loss stage.

A surgical method to repair leaking filtering blebs

Surgical revision of a chronically-thinned filtering bleb with a leak at the limbus is described. After surgical excision of the scarred cystic conjunctiva and Tenon's fascia surrounding the leaking bleb, relatively uninvolved conjunctiva and Tenon's fascia are mobilized with the help of a large relaxing incision in the superior fornix and sutured over the area of filtration. We have used this technique successfully in five cases to provide fresh tissue to repair the bleb leak and restore adequate filtration.

"Idiopathic" deep venous thrombosis: the value of routine abdominal and pelvic computed tomographic scanning

Recent studies have demonstrated an increased incidence in the diagnosis of malignancy subsequent to the diagnosis of deep venous thrombosis or pulmonary embolus. We reviewed 237 patients with venographically proven deep venous thrombosis over eight years. Of these, 216 had at least one predisposing cause for deep venous thrombosis; of the remaining 21 patients, three had hemoglobin determinations revealing anemia and were subsequently shown to have a malignant disease. One patient had two chief complaints and was shown to have deep venous thrombosis and malignant disease. The 17 remaining patients underwent computed tomographic scan of the abdomen and seven (41%) had abnormalities which proved to be malignant in origin. One further patient was diagnosed with carcinoma of the cervix two months following the onset of deep venous thrombosis. The remaining 10 patients continued free of malignant disease. Five have died of circulatory causes in the follow-up period. Seven of the nine patients diagnosed with malignancy succumbed within six months of the diagnosis. We conclude that only a small group of patients with deep venous thrombosis will have no identifiable cause for deep venous thrombosis and be asymptomatic for malignancy. Complete blood count, physical examination and computed tomographic scan of the abdomen at the time of venographic diagnosis of deep venous thrombosis is useful in diagnosis of "occult" malignancy. The number of gynecologic tumors would suggest the need for pelvic examination as well as radiographic examination. The presence of deep venous thrombosis and malignant disease is an ominous prognostic sign.

The Study of Surfaces Using Ion Beams

The study of surfaces has progressed by the development of techniques which use different probing species in the form of electrons, ions and photons. Specialisation within the use of each probe has resulted in the subsequent development of methods of analysis tuned to obtain specific information about a surface. In this presentation the various uses of ion scattering spectrometry over a wide range of energies will be reviewed to illustrate how it has been successfully used to yield structural and compositional information of the surface atomic layer and the near surface region.

Poxvirus and multiple tumors in an eastern gray squirrel

A moribund juvenile gray squirrel (Sciurus carolinensis) with numerous skin fibromas was submitted to the Northeastern Research Center for Wildlife Diseases. Necropsy revealed multiple firm white nodules in the lungs. On histologic examination, in addition to the skin lesions, fibromatous proliferations were seen in the wall of the alimentary tract, in 1 mesenteric lymph node, and in the myocardium. Tubular adenomas were seen in the renal cortex, and the lung nodules were bronchoalveolar adenomas. Eosinophilic intracytoplasmic poxvirus inclusion bodies were seen in both the mesenchymal and epithelial tumors.

Staphylococcus aureus mastitis in nursing mink affected with aleutian disease

An outbreak of staphylococcal mastitis in nursing female ranch mink (Mustela vison) is described. Lesions were acute necrotizing mastitis, fatty infiltration of the liver and renal tubules, and adrenal cortical hyperplasia. The presence of Aleutian disease in the herd suggests a role of immunosuppression in the outbreak.