Metabolic inhibitors accentuate the anti-tumoral effect of HDAC5 inhibition

The US FDA approval of broad-spectrum histone deacetylase (HDAC) inhibitors has firmly laid the cancer community to explore HDAC inhibition as a therapeutic approach for cancer treatment. Hitting one HDAC member could yield clinical benefit but this required a complete understanding of the functions of the different HDAC members. Here we explored the consequences of specific HDAC5 inhibition in cancer cells. We demonstrated that HDAC5 inhibition induces an iron-dependent reactive oxygen species (ROS) production, ultimately leading to apoptotic cell death as well as mechanisms of mitochondria quality control (mitophagy and mitobiogenesis). Interestingly, adaptation of HDAC5-depleted cells to oxidative stress passes through reprogramming of metabolic pathways towards glucose and glutamine. Therefore, interference with both glucose and glutamine supply in HDAC5-inhibited cancer cells significantly increases apoptotic cell death and reduces tumour growth in vivo; providing insight into a valuable clinical strategy combining the selective inhibition of HDAC5 with various inhibitors of metabolism as a new therapy to kill cancer cells.

Overview of the shuttle imaging radar-B preliminary scientific results

The Shuttle Imaging Radar-B experiment consisted of a large number of scientific investigations in the earth sciences. Nine oceanographic experiments were conducted to study the generation and propagation of surface waves, the dynamics of internal waves, oil slick detection, and the properties of southern polar ice. Stereo imaging from space allowed three-dimensional viewing of surface features. Geologic experiments were conducted to study subsurface penetration, structural mapping, and lithologic classification. Imaging radar angular scatterometry was used in the vegetation cover, forest type, and urban areas classification experiments. This article provides an overview of the scientific results, some of which are also presented in this issue.

Intrapartum management of nonvertex second-born twins: a critical analysis

OBJECTIVE

Our purpose was to assess the impact of the mode of delivery--vaginal delivery versus cesarean section--on the perinatal outcomes of the second-born breech twins.

STUDY DESIGN

This study was a retrospective analysis of second-born breech twins with a gestational age of > or =24 weeks at the onset of labor. The patients are divided into three groups: cesarean section without labor (group I), cesarean section after labor (group II), and vaginal breech delivery (group III).

RESULTS

There were 141 patients: 40 in group I, 66 in group II, and 35 in group III. There was no birth injury or neonatal death. Group II had one fetus with grade II intraventricular hemorrhage. There was no significant difference among the groups with regard to gestational age, birth weight, hyaline membrane disease, Apgar scores at 1 and 5 minutes, and cord blood gas indices, except venous pH in infants with birth weights <1500 g.

CONCLUSIONS

Vaginal delivery of breech second-born twins, with gestational ages of at least 24 weeks, especially those with birth weights of > or =1500 g, appears to be a safe alternative to cesarean section.

Interpreting natural language queries using the UMLS

This paper describes AQUA (A QUery Analyzer), the natural language front end of a prototype information retrieval system. AQUA translates a user's natural language query into a representation in the Conceptual Graph formalism. The graph is then used by subsequent components to search various resources such as databases of the medical literature. The focus of the parsing method is on semantics rather than syntax, with semantic restrictions being provided by the UMLS Semantic Net. The intent of the approach is to provide a method that can be emulated easily in applications that require simple natural language interfaces.

The integrated academic information management system at Columbia-Presbyterian Medical Center

Over the past seven years, Columbia-Presbyterian Medical Center has been planning and implementing an integrated academic information management system. Accomplishments to date include establishing an institutional information architecture, installing a campus-wide network of workstations, recruiting the staff needed to develop and implement the system, and developing various applications. This paper presents the rationale and steps involved in these accomplishments, as well as data on use of the system so far.

Hospitalized advanced cancer patients: a profile

More than half of all individuals diagnosed with cancer will not be cured and will require supportive care for some period. Nonetheless, few large scale studies have documented the prevalence and complexity of the problems of advanced disease. This study examined the demographic treatment and outcome variables for 1,103 admissions to a specialty acute care hospital devoted to the care of patients with advanced cancer. The population is profiled, and significant relationships among these variables are identified. The prevalence of major symptoms is documented. This data base study provides a foundation for further research.

Distribution of phospholipids around gramicidin and D-beta-hydroxybutyrate dehydrogenase as measured by resonance energy transfer

A resonance energy transfer method was developed to study the distribution of phospholipids around integral membrane proteins. The method involved measuring the extent of energy transfer from tryptophan residues of the proteins to different phospholipids labeled with a dansyl moiety in the fatty acid chain. No specific interactions were observed between gramicidin and dansyl-labeled phosphatidylcholine, phosphatidylethanolamine, or phosphatidic acid. The results were consistent with a random distribution of each phospholipid in the bilayer in the presence of gramicidin. However, a redistribution of both gramicidin and dansyl-labeled phospholipids was easily observed when a phase separation was induced by adding Ca2+ to vesicles made up of phosphatidylcholine and phosphatidic acid. Polarization measurements showed that in the presence of Ca2+ a rigid phosphatidic acid rich region and a more fluid phosphatidylcholine-rich region were formed. Energy-transfer measurements from gramicidin to either dansylphosphatidylcholine or dansylphosphatidic acid showed gramicidin preferentially partitioned into the phosphatidylcholine-rich regions. Energy-transfer measurements were also carried out with D-beta-hydroxybutyrate dehydrogenase reconstituted in a vesicle composed of phosphatidylcholine, phosphatidylethanolamine, and phosphatidic acid. Although the enzyme has a specific requirement for phosphatidylcholine for activity, the extent of energy transfer decreased in the order dansylphosphatidic acid, dansylphosphatidylcholine, dansylphosphatidylethanolamine. Thus, the enzyme reorganized the phospholipids in the vesicle into a nonrandom distribution.

Malignant lymphomas in a population at risk for acquired immune deficiency syndrome

Certain neoplasia are closely associated with acquired immune deficiency syndrome (AIDS). To evaluate this relationship the authors reviewed the occurrence of lymphomas in populations at high risk for AIDS; the study population included prisoners from New York State and nonprisoner intravenous drug abusers (IVDA). Non-Hodgkin's lymphoma was diagnosed in 16 prisoners, all of whom were IVDA, and four nonprisoner IVDA. The observed number of prisoners with non-Hodgkin's lymphoma (11) diagnosed between January 1, 1981 and December 12, 1984, significantly greater than the expected number (2.28) based on age adjusted incidence rates for the US population (P less than 0.001). The calculated average incidence rate for non-Hodgkin's lymphoma among New York State prisoners aged 20 to 49 years was 21.5/10(5) to 67.2/10(5), which was nearly sixfold to 18-fold higher than the general population. For prisoner IVDA, specifically, this incidence may be as high as 164/10(5), which represents a 40-fold increase in the relative risk compared with the general population. It is concluded that, non-Hodgkin's lymphoma is frequently a manifestation of AIDS among IVDA, and is the most common malignancy seen in IVDA with AIDS.

Adaptive changes induced by high altitude in the development of brain monoamine enzymes

Exposure to high altitude (HA) affects neurotransmitter levels in the adult brain and induces a number of neurologic and behavioral disturbances. The present work was undertaken to investigate the effects of chronic exposure to a moderate hypoxic environment (natural altitude of 3800 m, 12.8% O2 in inspired air) on the development from birth until adulthood of brain monoamine enzymes in rats. The activity of synthesizing (tyrosine and tryptophan hydroxylase) and catabolizing (catechol-O-methyl transferase and monoamine oxidase) enzymes were studied in discrete brain areas (cerebral cortex, cerebellum, mesodiencephalon, hypothalamus, corpus striatum, and pons medulla) and was shown to be selectively affected by HA, depending on the age of the animal and the brain region. In general, enzyme activity was less susceptible to HA during the first week after birth than at later ages, some brain areas such as the hypothalamus showing significant alterations in some enzymes throughout development, and in all enzymes at adulthood. Furthermore, in all brain areas and at all ages, tyrosine and tryptophan hydroxylase were more affected by HA than the catabolizing enzymes, and their activity was increased in some areas (e.g., cerebral cortex and cerebellum) but decreased in other areas (e.g., hypothalamus, mesodiencephalon, corpus striatum). These enzymatic changes and the corresponding alterations in precursor amino acids, particularly tryptophan, seem to be due more to the direct effect of hypoxia on oxygen-dependent enzymes, than to the stress. It appears that an hypoxic environment may provoke both early and long-term alterations in catecholamine and serotonin metabolism, thus neurotransmitter imbalances may explain some of the alterations in neurologic and endocrine development characteristic of the hypoxic animal.