Rethinking organizational performance management: a complexity theory perspective

Purpose

Traditional approaches to organizational performance management that emphasize objectivity, control and predictability are rapidly losing relevance in an environment characterized by increasing levels of complexity and dynamism. This paper draws on complexity theory to suggest a new paradigm for managing performance in organizations.

Design/methodology/approach

The paper draws on the common features of complex systems and the corresponding concept of emergence to revisit key themes in organizational performance management and propose a set of implications for research and practice.

Findings

Understanding organizations as complex systems and performance as an emergent property of such systems leads to a set of new research questions, the adoption of alternative methods and the formulation of novel propositions. It also has various implications for both academic research and managerial practice, from moving away from the traditional notion of organizational alignment to adopting a more explicit stakeholder-based view in the design and use of measurement systems.

Originality/value

The paper highlights the great potential of complexity theory for addressing contemporary issues in the field of organizational performance management and charting the landscape for its future development.

The roles of performance measurement and management in the development and implementation of business ecosystem strategies

Purpose

Performance measurement and management (PMM) systems have traditionally enabled strategy execution within and across firms. However, PMM have been criticized as overly static and deterministic and therefore inappropriate for emergent and dynamic contexts, such as those that characterize business ecosystems.The study aims to address the roles of organizational PMM practices in the development and implementation of business ecosystem strategies.

Design/methodology/approach

The authors carried out a qualitative, longitudinal study during 2016–2020 at a Japanese multinational technology corporation attempting to create an ecosystem strategy to expand its market and diversify its offering. The authors collected interview, observation and archival data, spanning the period from framing the initial strategy to establishing the ecosystem.

Findings

The process of developing and implementing the ecosystem strategy was emergent and highly iterative, rather than planned and linear, eventually requiring key decision-makers in the company to challenge some of their deeply held assumptions. PMM practices first acted as barriers to ecosystem development by promoting an excessive focus on revenue generation. Once modified, PMM helped capture, convey and reassess the ecosystem strategy. Performance targets, indicators and strategy maps were not just data gathering and reporting mechanisms but key means to express competing perspectives.

Practical implications

When developing an ecosystem strategy, managers should adopt a participatory and iterative approach, reviewing the complementary effects of various PMM tools at different points in time.

Originality/value

The study is among the first to provide an in-depth account of ecosystem strategy creation and implementation and to identify the diverse roles and effects of PMM practices in dynamic and complex contexts.

The effects of performance measurement system uses on organizational ambidexterity and firm performance

Purpose

This study aims to investigate how dynamic tensions between performance measurement system (PMS) uses enable organizations to achieve both exploitation and exploration and enhance firm performance.

Design/methodology/approach

The authors collected survey data on 153 Italian companies. Scales for each construct were validated through an exploratory factor analysis. Data on firm performance were cross-validated by using lagged accounting data. The authors tested our hypotheses using hierarchical ordinary least squares regressions, together with bootstrapping procedures for the test on mediation.

Findings

A diagnostic use of PMS has a positive association with both exploitation – e.g. reductions in total costs and lead times – and exploration, e.g. introduction of new products and extension of product ranges. The dynamic tension created by a joint diagnostic and interactive use has the strongest association with organizational ambidexterity, measured as the multiplicative interaction between exploration and exploitation.

Practical implications

If an organization or business unit is mainly pursuing exploitative goals, a mainly diagnostic use of PMS would be most suitable. If goals are both exploitative and explorative, a mix of diagnostic and interactive uses would be most effective.

Originality/value

This research helps reconcile conflicting views in the literature. The diagnostic use of PMS, far from acting as a “negative force,” appears to be necessary to guide opportunity search and to establish an appropriate scope for exploration-related activities. The authors’ focus on the uses of PMSs shows that ambidexterity is achieved through managerial capability, rather than just through the introduction of systems and structures.

Tumor mutational burden on cytological samples: A pilot study

BACKGROUND

Immune-checkpoint inhibitors (ICIs) represent an important treatment option for patients who have advanced stage non-small cell lung cancer (NSCLC). Currently, evaluation of the expression level of programmed death-ligand 1 (PD-L1) has proven highly successful as a positive predictive biomarker for ICIs. In addition to PD-L1, other promising predictive biomarkers are emerging, including high tumor mutational burden (TMB-H). However, measuring TMB-H remains challenging for several reasons, among which is the difficulty in obtaining adequate tissue material from NSCLC patients. There are no data in the current literature regarding the possibility of adopting cell blocks (CBs) for TMB evaluation; therefore, our goal was to evaluate the feasibility of analyzing TMB on CBs.

METHODS

For evaluation of differences in run metric parameters, 8 pairs of histological and CB samples from patients with NSCLC were analyzed using the Oncomine Tumor Mutational Load Assay on Ion Torrent S5 GS next-generation sequencing (NGS) platform.

RESULTS

Most CBs (6/8, 75.0%) were successfully analyzed by adopting the broad NGS panel approach. CBs provided results similar to those obtained on histological matched specimens in terms of median total reads (7207048.80 vs 7558817.80), median mapped reads (7075753.83 vs 7513822.00), median read lengths (115.50 vs. 113.00), median percentage of reads on-target (97.49% vs. 98.45%), median average reads per amplicon (454.67 vs 476.14), and median uniformity of amplicon coverage (83.52% vs 84.13%).

CONCLUSION

In this pilot study, we demonstrated the technical feasibility of assessing TMB on CBs.

Unproductive Effects of ALK Gene Amplification and Copy Number Gain in Non-Small-Cell Lung Cancer. ALK Gene Amplification and Copy Gain in NSCLC

Background: The Anaplastic Lymphoma Kinase (ALK) gene is known to be affected by several genetic alterations, such as rearrangement, amplification and point mutation. The main goal of this study was to comprehensively analyze ALK amplification (ALK-A) and ALK gene copy number gain (ALK-CNG) in a large cohort of non-small-cell lung cancer (NSCLC) patients in order to evaluate the effects on mRNA and protein expression. Methods:ALK locus number status was evaluated in 578 NSCLC cases by fluorescence in situ hybridization (FISH). In addition, ALK immunohistochemistry and ALK mRNA in situ hybridization were performed. Results: Out of 578 cases, 17 cases showed ALK-A. In addition, 14 cases presented ALK-CNG and 72 cases presented chromosome 2 polyploidy. None of those carrying ALK-A and -CNG showed either ALK immunohistochemical expression or ALK mRNA expression through in situ hybridization. We observed a high frequency of extra copies of the ALK gene. Conclusions: Our findings demonstrated that ALK-A is not involved in mRNA production and consequently is not involved in protein production; these findings support the hypothesis that ALK-A might not play a role in the pathogenesis of NSCLC, underlining the absence of a specific clinical application.

Circulating and tumor-associated caspase-4: a novel diagnostic and prognostic biomarker for non-small cell lung cancer

Late diagnosis limits therapeutic options and survival rate of non-small cell lung cancer (NSCLC) patients. Therefore the identification of biomarkers represents an emerging medical need.

A highly sensitive and specific test was developed to identify/quantify a novel/selective diagnostic biomarker for NSCLC patients, caspase-4. This test was validated by using i) plasma from 125 NSCLC patients and 79 healthy (non-pathological) subjects, ii) plasma from 139 smokers and iii) from 70 chronic-obstructive pulmonary disease (COPD) patients. Caspase-4 quantification was also assessed in the lung tumor mass of 98 paired NSCLC patients compared to 10 non-tumor lung tissues (i.e. tuberculosis).

Circulating caspase-4 was detected in both healthy and NSCLC patients; however at different range values: 2.603–3.372 ng/ml for NSCLC patients (95% CI) compared to 0.3994-0.6219 ng/ml for healthy subjects (95% CI). The sensitivity of the test ranged from 97.07% to 100%; the specificity was 88.1% with a positive predictive value of 92.54%, accuracy of 95.19% and AUC of 0.971. Smokers (95% CI, 0.3947–0.6197 ng/ml) and COPD patients (95% CI, 1.703–2.995 ng/ml) showed intermediate values of circulating caspase-4. Tissue levels of caspase-4 in the tumor mass showed that 72 (72.7%) out of 99 patients were positive. More importantly, higher levels (cut-off value = 0.307 ng/ml) of caspase-4 in the tumor mass were associated to reduced overall survival (median 0.92 years) compared to NSCLC patients with lower levels (median 3.02 years).

We report for the first time caspase-4 as a novel diagnostic and prognostic biomarker, opening new therapeutic perspectives for NSCLC patients.

The use of management control and performance measurement systems in SMEs

Purpose

The purpose of this paper is to respond to recent calls for understanding how multiple management control (MC) and performance measurement (PM) systems are used simultaneously for managing performance, particularly in the context of small- and medium-sized enterprises (SMEs).

Design/methodology/approach

Data are collected during an in-depth case study of MC and PM and management practices in a Dutch SME using multiple data sources and elicitation methods, including interviews and participant observations.

Findings

This study identifies managerial practices that enable the interplay of the four control systems – beliefs, boundaries, diagnostic and interactive – helping the organization manage organizational tensions in relation to short- and long-term focus, predictable goal achievement and search for new opportunities, internal and external focus, and control and creativity.

Research limitations/implications

This paper advances the research on integrating multiple aspects of performance management, particularly technical and social. This research is based on a single case study; future qualitative and quantitative studies could explore the interplay between the four control systems in other settings and explore the relationship between control systems and leadership style.

Practical implications

Managing performance requires active and continuous use of all four control systems. This is particularly salient in SMEs where less formal controls play a key role and where balance needs to be ensured despite the lack of managerial processes and capabilities.

Originality/value

The findings advance PM and management theory and practice in the context of SMEs.

Executing strategy through comprehensive performance measurement systems

Purpose

The purpose of this paper is to investigate the mediating role of comprehensive performance measurement systems (PMS) – i.e. measurement systems that comprise financial and non-financial indicators, and which also consist of indicators related to different aspects of an organisation’s operations – in the relationship between strategy and company performance.

Design/methodology/approach

Survey data of top managers of large European companies were collected and analysed by means of exploratory factor analyses and hierarchical regressions in order to validate the proposed hypotheses.

Findings

This research shows that different strategies lead to the use of different types of performance indicators. Also, it finds that the utilisation of a comprehensive PMS enables the implementation of both differentiation and cost-leadership strategies. Specifically, a comprehensive PMS positively mediates the effect of differentiation strategy on organisational and innovative performance, and of cost-leadership strategy on organisational performance.

Research limitations/implications

Further research could be undertaken in other contexts and consider additional factors, such as the structure, maturity and different uses of PMS, and the cost of measuring performance. Qualitative studies could examine the role of PMS in dynamic environments, as well as the evolution of PMS during strategic transitions.

Practical implications

Greater consideration should be given to the utilisation of different types of performance indicators when implementing and re-formulating strategy.

Originality/value

This study clarifies the links between strategy and performance measurement, and it is the first to identify the mediating effect of comprehensive PMS between strategy and company performance.

Clinical activity and tolerability of FOLFIRI and cetuximab in elderly patients with metastatic colorectal cancer in the CAPRI-GOIM first-line trial

BACKGROUND

In the cetuximab after progression in KRAS wild-type colorectal cancer patients (CAPRI) trial patients with metastatic colorectal cancer (mCRC) received 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) and cetuximab in first line followed by 5-Fluorouracil, folinic acid, oxaliplatin (FOLFOX) with or without cetuximab until progression. Limited data are available on the efficacy and safety of anti-epidermal growth factor receptor (anti-EGFR) agents on elderly patients with mCRC. In the current study we evaluated the efficacy and safety of FOLFIRI plus cetuximab in age-defined subgroups.

METHODS

A post-hoc analysis was performed in CAPRI trial patients; outcomes (progression-free survival (PFS), overall response rate (ORR), safety) were analysed by age-groups and stratified according to molecular characterisation. 3 age cut-offs were used to define the elderly population (≥65; ≥70 and ≥75 years).

RESULTS

340 patients with mCRC were treated in first line with FOLFIRI plus cetuximab. Among those, 154 patients were >65 years, 86 >70 years and 35 >75 years. Next-generation sequencing (NGS) was performed in 182 patients. Among them, 87 patients were >65 years, 46 >70 and 17 >75. 104 of 182 patients were wild type (WT) for KRAS, NRAS, BRAF, PIK3CA genes. In the quadruple WT group, 51 patients were ≥65 years; 29 were ≥70; 9 were ≥75. Median PFS was similar within the age-subgroups in the intention-to-treat population, NGS cohort and quadruple WT patients, respectively. Likewise, ORR was not significantly different among age-subgroups in the 3 populations. Safety profile was acceptable and similarly reported among all age-groups, with the exception of grade ≥3 diarrhoea (55% vs 25%, p=0.04) and neutropaenia (75% vs 37%, p=0.03) in patients ≥75 years and grade ≥3 fatigue (31% vs 20%, p=0.01) in patients <75 years.

CONCLUSIONS

Tolerability of cetuximab plus FOLFIRI was acceptable in elderly patients. Similar ORR and PFS were observed according to age-groups. No differences in adverse events were reported among the defined subgroups with the exception of higher incidence of grade ≥3 diarrhoea and neutropaenia in patients ≥75 years and grade ≥3 fatigue in patients <75 years.

TRIAL REGISTRATION NUMBER

2009-014041-81.

pRb2/p130 localizes to the cytoplasm in diffuse gastric cancer

pRb2/p130 is a key tumor suppressor, whose oncosuppressive activity has mainly been attributed to its ability to negatively regulate cell cycle by interacting with the E2F4 and E2F5 transcription factors. Indeed, pRb2/p130 has been found altered in various cancer types in which it functions as a valuable prognostic marker. Here, we analyzed pRb2/p130 expression in gastric cancer tissue samples of diffuse histotype, in comparison with their normal counterparts. We found a cytoplasmic localization of pRb2/p130 in cancer tissue samples, whereas, in normal counterparts, we observed the expected nuclear localization. pRb2/p130 cytoplasmic delocalization can lead to cell cycle deregulation, but considering the emerging involvement of pRb2/p130 in other key cellular processes, it could contribute to gastric tumorigenesis also through other mechanisms. Our data support the necessity of further investigations to verify the possibility of using pRb2/p130 as a biomarker or potential therapeutic target for diffuse gastric cancer.

Liver iron excess in patients with hepatocellular carcinoma developed on non-alcoholic steato-hepatitis

BACKGROUND/AIMS

Liver iron deposits are frequent in patients with non-alcoholic steato-hepatitis (NAFLD), but their role is not well defined. To investigate the effect of liver iron excess on the prevalence of hepatocellular carcinoma (HCC) in patients with NASH-related cirrhosis.

METHODS

Hepatic iron was measured retrospectively with a semiquantitative method in liver biopsies of 153 patients with NASH-related cirrhosis: 51 with HCC and 102 controls without HCC, matched for age, sex and stage of liver disease. The corrected total iron score (0-60) was the sum of three scores: the hepatocytic iron score (0-36), sinusoidal iron score (0-12), and portal iron score (0-12), multiplied by 3/3, 2/3, or 1/3 depending on the localisation of the iron in the nodules.

RESULTS

Conditional logistic regression analysis showed that iron deposits (corrected total iron score>0) were more frequent in HCC patients than in controls. The median corrected total iron score was significantly higher in HCC patients than in controls. The liver iron overload was sinusoidal.

CONCLUSIONS

Iron deposition in the liver was more frequent in patients with NASH-related cirrhosis with HCC than in HCC-free controls. Liver iron overload may be associated with development of HCC in patients with NASH-related cirrhosis.

Tissue ghrelin level and gastric emptying rate in adult patients with celiac disease

Celiac disease (CD) patients show a number of gastrointestinal motor abnormalities. Ghrelin, a gastric peptide implicated in short-term feeding control and long-term body weight regulation, has been recently considered a key regulator of gastric motility. The aim of this study was to evaluate the gastric emptying rate of solids and the density of ghrelin-immunopositive cells in adult CD patients before and at least 1 year after starting a gluten-free diet. Twenty CD patients (M 8/F 12; mean age 36 years) and 10 controls underwent endoscopy with gastric and duodenal biopsies and 13C-octanoic acid breath test to measure gastric emptying of solids. Celiac disease patients repeated the protocol at least 1 year after starting gluten-free diet. Ghrelin tissue levels were evaluated by immunohistochemistry on gastric mucosa specimens. Gastric emptying time was normal in all control subjects (t(1/2) = 89 +/- 16 min) while it was delayed in CD patients prior to gluten-free diet (t(1/2) = 252 +/- 101 min; P < 0.005). The mean number of ghrelin-positive cells/field (x 400) was 14.4 +/- 2.7 in controls and 25.3 +/- 5.7 in CD patients respectively (P < 0.0001). Gluten withdrawal was effective in normalizing gastric emptying time in all CD patients (97 +/- 14 min; P < 0.0001) and resulted in a significant reduction of the density of ghrelin-immunopositive cells (19.8 +/- 5.4; P < 0.0001). The density of ghrelin-positive cells correlated directly with the degree of duodenal damage (P < 0.001) and inversely with the body mass index of CD patients (P < 0.0001). However, in neither CD patients nor controls, a correlation between tissue ghrelin levels and gastric emptying rate was detected. In conclusion, tissue ghrelin level does not correlate with gastric emptying rate in adult CD patients and in controls.

Evidence of COX-1 and COX-2 expression in Kaposi's sarcoma tissues

Cyclooxygenases (COXs) are enzymes catalysing prostaglandin synthesis and are implicated in the carcinogenesis of some cancer types. In addition, an important role of these enzymes in herpesvirus infections was demonstrated and it has recently been proposed that COX-2 may participate in herpesvirus-induced neoplasia such as Kaposi's sarcoma (KS). To date no immunohistochemical study has been performed to determine the identification of COX-1 and COX-2 in KS. We have investigated 35 cases of classic KS and 27 cases of epidemic KS form in order to study the distribution and localisation of COXs. We have examined by immunohistochemistry the expression of COX-1 and COX-2 in classic and epidemic forms of KS also in relationship to the characteristic morphological phases (patch, plaque and nodular stage) of KS and cell localisation by double immunostaining. Moreover, we have obtained COX-1 and COX-2 expression by Western blot analysis. Our results establish that (a) COX-1 and COX-2 are overexpressed significantly in classic and epidemic KS compared with control skin tissues (P<0.01 and P>0.03, respectively, for COX-1; P<0.01 and P>0.03, respectively, for COX-2); (b) the extent and intensity staining for both COXs were higher in classic than in epidemic form of KS. Our data support the hypothesis that both COXs may be involved in the pathogenesis of KS.

Evidence of angiogenesis in bronchial biopsies of smokers with and without airway obstruction

The involvement of bronchial vasculature in the airway remodelling occurring in symptomatic smokers with normal lung function and with chronic obstructive pulmonary disease (COPD) has been poorly investigated. An immunohistochemical study was performed on bronchial biopsies taken from 8 non-smokers and 18 smokers divided, according to global health initiative on obstructive lung diseases (GOLD) classification of COPD, into two groups, GOLD 0 and GOLD 2, each of 9 subjects. The number of vessels and the percentage of vascular area in the lamina propria were evaluated by mAb anti-collagen IV. Cellular expression of VEGF and vascular expression of alphavbeta3 integrin were evaluated by the specific monoclonal antibodies. An image processing and analysis system was used to quantify the immunohistochemical data. The number of vessels, the vascular area, the cellular expression of VEGF, the number and percentage of alphavbeta3 positive vessels were significantly higher in GOLD 0 and in GOLD 2 smokers than in non-smokers. The comparison between GOLD 0 and GOLD 2 smokers did show a weak but significantly lower number of vessels in GOLD 2, while the vascular area and the percentage of alphavbeta3 positive vessels did not differ between the two groups. A higher cellular VEGF expression was detected in the GOLD 2 than in the GOLD 0 group. Angiogenesis of bronchial vessels is a component of the airway remodelling occurring in symptomatic smokers with normal lung function and with COPD, it seems independent by the development of airway obstruction and not related to its severity.

A clinical-morphological study on cholestatic presentation of nonalcoholic fatty liver disease

To determine the association among the clinical, biochemical, and histological features of cholestasis, we analyzed all the relevant data of the patients recorded in our non-alcoholic fatty liver disease (NAFLD) database. We selected 20 NAFLD patients with abnormal transaminase levels, with both alkaline phosphatase >500 U/L and gamma-glutamyl transpeptidase >250 U/L. Their histological features were compared with those of a group of patients with NAFLD matched for sex, age, and body mass index and of a group of patients matched for sex, body mass index and histological NAFLD grading/staging. Cases and controls satisfied, on histology, the criteria for NASH. The presence of cholestasis in our patients was correlated with injury of the bile duct epithelium, characterized by cholangitis, swelling, variable bile duct loss, and bile stasis. Compared to NAFLD patients of similar age, sex, and body mass index, the cholestatic group had total and severe histological liver impairment. When we analyzed the group of patients histologically identified on the basis of identical stage and grade severity, we could not find any evidence of significant bile damage, compared to cases, despite the control group's significantly older age. NAFLD patients with biochemical cholestasis have a histological picture of bile damage; they have more advanced histological impairment than patients matched for age, sex and body mass index.

CDK9/CYCLIN T1 expression during normal lymphoid differentiation and malignant transformation

CDK9 is a member of the CDC2-like family of kinases. Its cyclin partners are members of the CYCLIN T family (T1, T2a, and T2b) and CYCLIN K. The CDK9/CYCLIN T1 complex is very important in the differentiation programme of several cell types, controlling specific differentiation pathways. Limited data are available regarding the expression of CDK9/CYCLIN T1 in haematopoietic and lymphoid tissues. The aim of this study was to analyse the expression of the CDK9/CYCLIN T1 complex in lymphoid tissue, in order to assess its role in B- and T-cell differentiation and lymphomagenesis. CDK9/CYCLIN T1 expression was found by immunohistochemistry in precursor B and T cells. In peripheral lymphoid tissues, germinal centre cells and scattered B- and T-cell blasts in interfollicular areas expressed CDK9/CYCLIN T1, while mantle cells, plasma cells, and small resting T-lymphocytes displayed no expression of either molecule. CDK9/CYCLIN T1 expression therefore appears to be related to particular stages of lymphoid differentiation/activation. CDK9 and CYCLIN T1 were highly expressed in lymphomas derived from precursor B and T cells, from germinal centre cells, such as follicular lymphomas, and from activated T cells (ie anaplastic large cell lymphomas). Hodgkin and Reed-Sternberg cells of classical Hodgkin's lymphoma also showed strong nuclear staining. Diffuse large B-cell, Burkitt's lymphomas, and peripheral T-cell lymphomas, among T-cell lymphoproliferative disorders, showed a wide range of values. No expression of CDK9 or CYCLIN T1 was detected in mantle cell and marginal zone lymphomas. However, at the mRNA level, an imbalance in the CDK9/CYCLIN T1 ratio was found in follicular lymphoma and diffuse large B-cell lymphomas with germinal centre phenotype, and in the cell lines of classical Hodgkin's lymphomas, Burkitt's lymphomas, and anaplastic large cell lymphoma, in comparison with reactive lymph nodes. These results suggest that the CDK9/CYCLIN T1 complex may affect the activation and differentiation programme of lymphoid cells. The molecular mechanism through which the CDK9/CYCLIN T1 complex is altered in malignant transformation needs to be elucidated.

RB2/p130 gene-enhanced expression down-regulates vascular endothelial growth factor expression and inhibits angiogenesis in vivo

Angiogenesis is an essential step in the progression of tumor formation and development. The switch to an angiogenetic phenotype can occur as a distinct step before progression to a neoplastic phenotype and is linked to genetic changes such as mutations in key cell cycle regulatory genes. The pathogenesis of the angiogenetic phenotype may involve the inactivation of tumor suppressor genes such as the "guardian of the genome," p53, and the cyclin-dependent kinase inhibitor p16. Retinoblastoma family member RB2/p130 encodes a cell cycle regulatory protein and has been found mutated in different tumor types. Overexpression of RB2/p130 not only suppresses tumor formation in nude mice but also causes regression of established tumor grafts, suggesting that RB2/p130 may modulate the angiogenetic balance. We found that induction of RB2/p130 expression using a tetracycline-regulated gene expression system as well as retroviral and adenoviral-mediated gene delivery inhibited angiogenesis in vivo. This correlated with pRb2/p130-mediated down-regulation of vascular endothelial growth factor protein expression both in vitro and in vivo.

Mutations in the retinoblastoma-related gene RB2/p130 in primary nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an endemic cancer in southern China and northern Africa, and its pathogenesis is not yet well defined at the molecular level. Although the involvement of p53 and of the retinoblastoma gene (RB/p105) in NPC has been well studied, there is paucity of mutational data regarding the retinoblastoma-related gene RB2/p130 in primary tumors and particularly in NPC. We have shown previously that RB2/p130 could be rearranged in a nasopharyngeal cell line. In the present study, we screened by single-strand conformation polymorphism and sequence analysis the retinoblastoma-related gene RB2/p130 for mutations within exons 19-22. Mutations in the RB2/p130 gene were detected in 3 of 10 primary human NPCs from Northern Africa (30%). These findings, along with previous data showing that genetic replacement of RB2/p130 restores a normal growth pathway in the nasopharyngeal cell line Hone-1, strengthen the hypothesis that genetic changes of RB2/p130 may be involved in the development and/or progression of nasopharyngeal cancer and suggest that RB2/p130 could be considered a tumor suppressor gene and may be a candidate for novel gene therapeutic approaches for NPC.

Regulatory functions of Cdk9 and of cyclin T1 in HIV tat transactivation pathway gene expression

HIV-1 gene expression relies upon a complex machinery that is primarily controlled by two viral regulatory proteins, Tat and Rev. Rev is involved in regulating post-transcriptional events of HIV-1 gene expression. The Tat protein transactivates transcription from the HIV-1 5' long terminal repeat (LTR) and acts in synergy with specific cellular factors. Recently, it has been shown that one set of these cellular factors is a protein kinase activity termed TAK (Tat-associated kinase), which activates transcription by hyperphosphorylation of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II. TAK also enhances transcription of HIV-2, together with the retroviral transactivator, Tat-2. The TAK activity appears to be related to the CTD kinase P-TEFb, which stabilizes transcription elongation of many genes and was originally isolated from Drosophila extracts. Both TAK and P-TEFb contain at least two subunits: the cyclin-dependent kinase, CDK9 (PITALRE), the catalytic subunit, and the regulatory subunit, cyclin T1. CDK9 and cyclin T1 are ubiquitous factors that affects many cellular processes, including cell differentiation and apoptosis. The involvement of TAK in HIV-1 and HIV-2 gene expression is an important aspect in the biology of these two retroviruses, and may lead to the development of novel antiretroviral drugs and/or gene therapy approaches for the treatment of patients with AIDS.

Pathological relevance of epithelial and mesenchymal phenotype plasticity

Epithelium and mesenchyme, two tissue types virtually found in every organ, are endowed with fundamentally different functional properties. Active motility, a capability that is limited to the mesenchymal repertoire, is the principal characteristic that distinguishes them. During embryonic development, conversions from epithelium to mesenchyme and from mesenchyme to epithelium normally occur, allowing morphogenetic processes and tissue remodelling to take place. However, there is now increasing evidence that the modulation between the epithelial and the mesenchymal phenotypes is not limited to embryonic life. Indeed, the pathogenesis of some adult diseases seems to implicate an inappropriate activation of this change. On the other hand, failure of normally occurring embryonic epithelial-mesenchymal interconversions could result in the development of some pathologies. It is now possible to study some molecular events underlying these phenotype transitions, since several biological agents implicated in the epithelial-mesenchymal interconversion, such as growth factors, extracellular matrix components and their receptors, transcription factors and oncogenes have been identified. The malignant potential of some oncogenes seems to express itself through the disruption of the mechanisms involved in the maintenance of the epithelial phenotype while, on the other hand, some observations suggest the existence of regulatory genes able to counteract the action of oncogenes by restoring epithelial characteristics. Therefore, the manipulation of the tissue phenotype could represent a novel strategy for the prevention and treatment of diseases in the future.

[Co-trimoxazole administration: a rare cause of hypoglycemia in elderly persons]

We report a case of severe hypoglycaemia following co-trimoxazole therapy. An 88-year-old woman was admitted with urinary tract infection and treated with co-trimoxazole (960 mg bid). Seven days after initiation of the treatment she became comatose. Blood sugar was 1.3 mmol/l and C-peptide at the upper limit of normal range. Glucose infusion restored normal consciousness and no hypoglycaemia recurred after interruption of co-trimoxazole therapy. Advanced aged was the only risk factor identified. Other risk factors described in previous case reports are renal failure, poor nutritional state and high doses of co-trimoxazole.

[Benign ulcers of the cecum]

Benign ulceration of the cecum is an uncommon lesion that was originally described by Cruveilhier in 1832. Etiology is unknown and symptomatology not pathognomonic. Pre-operative and intraoperative diagnosis is rare and difficult. Definitive diagnosis is usually obtained by histologic evaluation of the surgical specimen after a right hemicolectomy performed for a suspect of a neoplasm of the cecum. The authors present 7 cases of cecal ulcers and suggest that preoperative diagnosis may be due after a colonoscopy with biopsy. This examination may be performed only in that cases that appear without symptoms of acute abdomen. The authors suggest also to perform right hemicolectomy.

Prognostic value of p53 in non-small cell lung cancer: relationship with proliferating cell nuclear antigen and cigarette smoking

p53 mutations are among the most frequent genetic alterations reported in human lung cancer. Although the prognostic value of altered p53 expression is still debated, it is accepted widely that estimation of the proliferation rate has an important prognostic role. Moreover, an association between certain types of human lung cancers and tobacco use is well known. Drawing from this background, we investigated the immunohistochemical expression of mutant oncogenic p53 protein, and related it to the smoking history of 61 patients with non-small cell lung carcinoma (NSCLC) and to the expression pattern of proliferating cell nuclear antigen (PCNA), which is considered to be an important negative prognostic factor in several neoplasms. We found p53 overexpression in 22 (36.1%) specimens, including 16 squamous carcinomas (41%) and six (27.2%) adenocarcinomas. PCNA nuclear staining was detected in 98.4% of the specimens, and a significantly higher PCNA expression score was found in all of the p53-positive samples. When the patient survival time was compared, p53 accumulation had a statistically significant negative prognostic value (P < .001). This was supported by a Kaplan-Meier survival percentage plot of immunohistochemically p53-undetectable specimens and p53-detectable specimens. These latter patients had a greatly reduced survival time. A relationship was established between p53 immunohistochemical detection and the smoking history of the patients. None of the specimens from the nonsmoking patients expressed immunohistochemically detectable p53 protein. Altered p53 expression was detected in 40.7% of smoking patients. Our findings support the hypothesis of involvement of p53 mutations in tobacco-induced carcinogensis and indicate that altered p53 expression plays an important prognostic role in NSCLC in smokers.

[Role of splenectomy in Chediak-Higashi syndrome in its accelerated phase]

Chediak-Higashi (C.H.S.) syndrome is a rare immunodeficiency, due to defective granulocyte activity. The syndrome is characterized by large inclusion bodies in the leukocytes, albinism, photophobia, nystagmus, and recurrent infections. Some patients develop hepatosplenomegaly, lymphadenopathy, pancytopenia and widespread organ infiltrates with mononucleated cells. This phase is called "accelerated (or lymphoma-like syndrome) phase". A 5 years old girl with C.H.S. in accelerated phase received initially medical treatment without improvement. A splenectomy was performed to remove the hypersplenism and the mechanical compression of the spleen on the gut. Few days after the splenectomy the fever and the pancytopenia disappeared. The pathological examination of the spleen showed multiple intraparenchymal abscesses. Unfortunately, six months after the operation, she died after an acute episode of pneumonia, with normal hematological pattern. The splenectomy may play a role in the "accelerated phase" of C.H.S., but new treatments (bone marrow transplantation) are necessary to remove the basic disease.