Malignant lymphoma of the head and neck

Oral Diseases (2010) 16 , 119–128 Malignant lymphomas represent approximately 5% of all malignant neoplasms of the head and neck area. They are classically divided into two subgroups, Hodgkin’s lymphomas (HLs) and non‐Hodgkin’s lymphomas (NHLs). We describe the clinical characteristics of head and neck lymphomas and the methods to establish the diagnosis. The World Health Organization classification of lymphoid tissues describes more than 50 different histological types, and we analyse the most common staging system for lymphomas, the Ann Arbor staging system. Finally, the different therapeutic approaches are discussed.     

Optimal HIV testing and earlier care: the way forward in Europe

The articles in this supplement were developed from a recent pan-European conference entitled 'HIV in Europe 2007: Working together for optimal testing and earlier care', which took place on 26–27 November in Brussels, Belgium. The conference, organized by a multidisciplinary group of experts representing advocacy, clinical and policy areas of the HIV field, was convened in an effort to gain a common understanding on the role of HIV testing and counselling in optimizing diagnosis and the need for earlier care. Key topics discussed at the conference and described in the following articles include: current barriers to HIV testing across Europe, trends in the epidemiology of HIV in the region, problems associated with undiagnosed infection and the psychosocial barriers impacting on testing. The supplement also provides a summary of the World Health Organization's recommendations for HIV testing in Europe and an outline of an indicator disease-guided approach to HIV testing proposed by a committee of experts from the European AIDS Clinical Society (EACS). We hope that consideration of the issues discussed in this supplement will help to shift the HIV field closer towards our ultimate goal: provision of optimal HIV testing and earlier care across the whole of the European region.     

Enhanced oxidative stress and increased mitochondrial mass during Efavirenz-induced apoptosis in human hepatic cells

BACKGROUND AND PURPOSE

Efavirenz (EFV) is widely used in the treatment of HIV-1 infection. Though highly efficient, there is growing concern about EFV-related side effects, the molecular basis of which remains elusive.

EXPERIMENTAL APPROACH

In vitro studies were performed to address the effect of clinically relevant concentrations of EFV (10, 25 and 50 µM) on human hepatic cells.

KEY RESULTS

Cellular proliferation and viability were reduced in a concentration-dependent manner. Analyses of the cell cycle and several cell death parameters (chromatin condensation, phosphatidylserine exteriorization, mitochondrial proapoptotic protein translocation and caspase activation) revealed that EFV triggered apoptosis via the intrinsic pathway. In addition, EFV directly affected mitochondrial function in a reversible manner, inducing a decrease in mitochondrial membrane potential and an increase in mitochondrial superoxide production, followed by a reduction in cellular glutathione content. The rapidity of these actions rules out any involvement of mitochondrial DNA replication, which, until now, was thought to be the main mechanism of mitochondrial toxicity of antiretroviral drugs. Importantly, we also observed an increase in mitochondrial mass, manifested as an elevated cardiolipin content and enhanced expression of mitochondrial proteins, which was not paralleled by an increase in the mtDNA/nuclear DNA copy number ratio. The toxic effect of EFV was partially reversed by antioxidant pretreatment, which suggests ROS generation is involved in this effect.

CONCLUSION AND IMPLICATIONS

Clinically relevant concentrations of EFV were shown to be mitotoxic in human hepatic cells in vitro, which may be pertinent to the understanding of the hepatotoxicity associated with this drug.     

肥胖抑素与Ghrelin

体重部分地受大脑或胃肠道合成的肽类激素的调控。Ghrelin前激素原含117个氨基酸残基，经翻译后裂解作用形成Ghrelin，由28个氨基酸组成。我们检索基因库，与另外11种哺乳动物进行Ghrelin前激素原的序列比较，除了已知的Ghrelin信号肽，我们还确定了另一保守区，侧链含有转化酶裂解部位，编码一种23个氨基酸的肽链，其C端侧翼有保守的甘氨酸残基，可能经酰胺化作用。我们称此Ghrelin相关肽为肥胖抑素（Obestatin）。     

Ascorbic acid during cerebral ischemia in newborn piglets

We measured ascorbic acid (reduced and oxidized) in brain, CSF and blood, before, during and after cerebral ischemia in newborn piglets. Bilateral carotid ligation induced a 54% decrease in cerebral blood flow (p < 0.01) and a 43% decrease in the cerebral metabolic rate of oxygen (p < 0.01). After ischemia and reperfusion, we obtained a 60% decrease (p < 0.01) in total brain ascorbic acid content. CSF ascorbic acid increased during reperfusion:+60% at 30min (p < 0.001) and +160% at 120min (p < 0.05). Blood ascorbic acid content did not change. These changes and the absence of massive oxidation of ascorbic acid in brain tissue suggest release of ascorbic acid by the brain during ischemia.     

Differential expression of crown gall tumor markers in transformants obtained after in vitro Agrobacterium tumefaciens-induced transformation of cell wall regenerating protoplasts derived from Nicotiana tabacum

To obtain transformation of plant cells, we incubated 3-day-old cell wall-regenerating protoplasts from tobacco with Agrobacterium tumefaciens harboring tumor-inducing plasmids. Putative transformed tobacco cells were selected by phytohormone autotrophic growth and were shown to be transformed by the detection of the tumor cell specific enzymes lysopine dehydrogenase or nopaline dehydrogenase. This was substantiated by the detection, in transformed tumor tissues, of DNA sequences homologous to sequences in the tumor-inducing plasmid. Segregation of tumor markers has been observed among the transformants and it is suggested that this happened during the initiation of the transformation. The stable character of the transformed state was shown by the retention of tumor markers in subcloning of primary transformants under nonselective conditions. Suppression of the neoplastic state of transformants could take place, resulting in the development of transformed shoots. Indications were obtained for the inheritance of tumor markers through meiosis from seedlings obtained from seeds of flowering transformed plants that still expressed nopaline synthesis.