Hb taradale [beta82(EF6)Lys-->Arg]: a novel mutation at a 2,3-diphosphoglycerate binding site

Hb Taradale [beta82(EF6)Lys-->Arg] was initially detected as a split Hb A0 peak on Hb A1c, monitoring. Red cell parameters, hemoglobin (Hb) electrophoresis and stability tests were normal. Mass spectrometry (ms) clearly identified a variant beta chain with a mass increase of 28 Da and peptide mapping located the mutation site to peptide betaT-9. DNA sequencing confirmed the presence of a novel beta82(EF6)Lys-->Arg mutation. This conservative substitution at a 2,3-diphosphoglycerate (2,3-DPG) binding site did not, however, appear to affect the P50 for oxygen binding.     

Diallyl trisulfide modulates cell viability and the antioxidation and detoxification systems of rat primary hepatocytes

This study investigated the effects of various concentrations of diallyl trisulfide (DATS) and incubation times on cell viability, glutathione (GSH) content, and GSH-related enzyme activity in rat primary hepatocytes. Isolated and cultured primary rat hepatocytes were used as an experimental model. Cells were treated with 0 (control), 0.025, 0.05, or 0.25 mmol/L DATS for 0, 4, 8, or 24 h. After 24 h of treatment, some cells were incubated in fresh medium without DATS for an additional 24 h (48-h incubations). Based on lactate dehydrogenase (LDH) leakage and morphological examination, hepatocytes treated with 0.025 mmol/L DATS did not differ from the control cells at 4, 8, 24, and 48 h of incubation. However, LDH leakage was higher than in the control cells (P < 0.05) when the hepatocytes were treated with 0.05 or 0.25 mmol/L DATS for 4 h or more. The intracellular GSH levels of hepatocytes treated with 0.025 or 0.05 mmol/L DATS were higher than those of the control cells (P < 0.05), whereas those treated with 0.25 mmol/L DATS did not differ. The activity of glutathione reductase (GRd) was higher than in the control cells at 24 h (P < 0.05) when the hepatocytes were treated with 0.025 mmol/L DATS. When the hepatocytes were treated with 0.025 mmol/L DATS, the activity of glutathione S-transferase (GST) was higher than in the control cells at 48 h (P < 0.05). In hepatocytes treated with 0.05 mmol/L DATS, the activity of GST and glutathione peroxidase (GPx) was higher than in the control cells (P < 0.05) at 24 and 48 h of incubation. The results indicate that 0.025 or 0.05 mmol/L DATS could enhance antioxidation and detoxification capabilities by increasing the intracellular GSH level and the activity of GPx, GRd, or GST in rat primary hepatocytes. However, 0.05 or 0.25 mmol/L DATS might adversely affect the viability of hepatocytes.     

Two new paracetamol/dioxane solvates--a system exhibiting a reversible solid-state phase transformation

This work reports on the crystal structures of two dioxane solvates of paracetamol that are true polymorphs. The high temperature phase is an orthorhombic form, space group Pbca, Z = 8, a = 12.6078(3) A, b = 12.1129(2) A, c = 13.4138(3) A, V = 2048.52(7) A(3), (at 295 K) and the low temperature form is monoclinic, space group P21/c, Z = 4, a = 12.325(6) A, b = 11.965(4) A, c = 13.384(6) A, beta = 92.01 degrees, V = 1972.6(14)A(3) (at 123 K). The structures of these polymorphs are described as is the interrelationship between the two structures. In addition to the structural interrelationship, it is shown that the two forms undergo a reversible phase transformation. Desolvation of either form generates the stable monoclinic phase of paracetamol.     

Developmental genetic malformations of the cerebral cortex

Cortical malformations give rise to severe clinical manifestations such as epilepsy and mental retardation, but sometimes to more subtle problems like dyslexia. From a clinical standpoint, such structural abnormalities are diagnosed by radiographic and histologic findings, with disease classifications often based on these observations. Using this categorization, many of the responsible genes have been determined and now provide a means of understanding the molecular basis of the neurologic disorders. This review discusses the known genetic developmental syndromes in the context of the observed cortical malformations, the expression and function of the responsible genes, and their potential roles during the various stages of central nervous system development.     

c-Myc alters the DNA damage-induced G2/M arrest in human mammary epithelial cells

Effects of c-Myc overexpression on the DNA damage-induced G2/M checkpoint were studied in finite lifespan, normal human mammary epithelial cells (HMECs). Previously, we showed that c-Myc attenuates G1/S arrest and leads to an inappropriate entry of cells with damaged DNA into the S phase, following treatment with ionising radiation (IR). Here we show that, in striking contrast to control cells, c-Myc-overexpressing HMECs demonstrate a significant attenuation of the G2/M arrest, following IR, and enter into inappropriate mitoses. At the molecular level, ectopic overexpression of c-Myc leads to an unusually high level of expression of cyclin B1, and the elevated levels of cyclin B1 were maintained, after gamma-irradiation. Introduction of DNA damage in c-Myc-overexpressing, normal mammary epithelial cells eventually induces apoptosis, indicating a dramatic sensitisation by c-Myc of DNA damage-induced apoptosis. These two remarkable phenotypes, checkpoint attenuation and sensitisation to apoptosis, resulting from a deregulation of the protooncogene c-myc, may produce a unique pattern of alternating cycles, consisting first of amplification of DNA damage, followed by apoptosis-assisted selective pressure. The result of this alternating pattern of damage apoptosis could facilitate the selection of certain genomic alterations required for cellular survival and cellular transformation.     

T lymphocytes isolated from patients with advanced colorectal cancer are suitable for gene immunotherapy approaches

Despite improvements in treatment, the 5-year survival for metastatic colorectal cancer remains poor. Novel approaches such as gene immunotherapy are being investigated to improve treatment. Retroviral gene transfer methods have been shown to transduce primary human T lymphocytes effectively resulting in the expression of therapeutic genes. However, a number of defects have been identified in T lymphocytes isolated from patients bearing tumour, which may have critical implications for the development of gene-targeted T cells as an anticancer therapy. To address this issue, primary T lymphocytes were isolated from patients with advanced colorectal cancer and tested for their ability to be transduced and to express subsequently a chimeric immune receptor consisting of a single-chain antibody fragment antigen-binding moiety specific for carcinoembryonic antigen (CEA) fused to the T cell receptor (TCR) CD3zeta chain. In 10 out of 10 patients, T lymphocytes were transduced, expanded in the absence of selection and tested for functional activity against CEA-expressing tumour cells. In each case, functional-specific cytotoxic activity was observed. Negligible activity was found in control cultures. This study highlights the feasibility of patient-derived T lymphocytes as a source of immune cells for autologous gene immunotherapy approaches.     

Unintentional rechallenge resulting in a causative relationship between ketoconazole and acute liver injury

We present the case of a female patient in whom acute overt hepatitis developed after 60 days of ketoconazole administration (200 mg/day). A prompt renewed hepatic injury 48 hours after an unintentional rechallenge 30 months later provided definitive evidence for a causative relationship between ketoconazole and acute liver injury. Histological examination revealed acute hepatitis with bridging hepatic necrosis. Clinicians should be aware of this cause and effect relationship between ketoconazole and acute liver injury, which can result in prompt severe acute liver injury after rechallenge.     

Soluble adhesion molecules and cytokines in tumor-associated tissue eosinophilia of nasopharyngeal carcinoma

The phenomenon of tumor-associated tissue eosinophilia (TATE) is seen in some cases of nasopharyngeal carcinoma (NPC) and is characterized by the eosinophils breaking through the vascular wall and pervading the tumor stroma. The margination and trans-endothelial migration of eosinophils in a typical inflammatory reaction depend on the activating effects of certain cytokines and the expression of adhesion molecules on the eosinophils and endothelial cells. In order to investigate whether the adhesion molecules and activating cytokines play a role in eosinophil tumor infiltration, we measured the serum levels of 3 adhesion molecules, intercellular adhesion molecule-1, E-selectin and vascular cell adhesion molecule-1, and 2 cytokines, IL-3 and IL-5, in 60 NPC patients and 40 normal healthy subjects. We found that the NPC patients had higher serum levels of all three soluble adhesion molecules than the normal subjects but the levels of adhesion molecules failed to correlate with the TATE phenomenon. The levels of IL-3 and IL-5 appeared not to differ between the NPC and control groups. We postulate that the three soluble adhesion molecules do not play a major role in TATE and that their elevation in serum may be due to local and/or systemic immune responses.