Comparative study of radiation-induced G2 phase delay and chromatid damage in families with ataxia-telangiectasia.

Two assay systems, radiation-induced chromosome aberrations and flow cytometry, were compared for the detection of ataxia-telangiectasia (A-T) heterozygotes. In three A-T families, the frequencies of chromatid aberrations in phytohemagglutinin-stimulated blood lymphocytes after 1 Gy of gamma-irradiation were twofold higher in A-T homozygotes than in obligate A-T heterozygotes, which were in turn approximately twofold higher than in normal control cells. Other consanguineous relatives of A-T patients had intermediate levels of induced chromatid aberrations, suggesting that they were carriers of the gene.

Prolonged expression of c-jun and associated activity of the transcription factor AP-1, during apoptosis in a human leukaemic cell line.

The product of the c-jun gene is a component of the transcription factor AP-1, which plays a critical regulatory role in the cellular response to certain proliferative stimuli. In this report, we demonstrate the prolonged expression of c-jun mRNA during apoptosis induced in a human leukaemic T-cell line, CEM C7, by treatment with either dexamethasone or gamma-radiation. However, overexpression of the c-jun mRNA was not accompanied by either increased expression of jun protein, or increased AP-1 DNA binding activity.

Molecular biology and the radiation oncologist.

An overview is provided of several recent advances in our understanding of the molecular events that occur when cells are exposed to ionizing radiation. A basic knowledge of molecular radiobiology is necessary so that the radiation oncologist can (i) screen cancer patients for an abnormally reduced or exaggerated response to radiotherapy; and (ii) devise novel ways to counter the molecular pathways that sustain malignant progression.

Antiemetic-induced akathisia in cancer patients receiving chemotherapy.

A structured, prospective telephone interview was used to assess the prevalence of akathisia in 24 cancer patients receiving metoclopramide or prochlorperazine during or after chemotherapy. Half of the patients reported subjective motor restlessness, and 75% stated that they would not have informed staff. This report suggests that akathisia is frequently unrecognized in chemotherapy patients receiving metoclopramide and prochlorperazine.

Psychiatric comorbidity and length of stay in the general hospital. A critical review of outcome studies.

The authors critically reviewed 26 international and American outcome studies that assessed the effect of psychiatric comorbidity on length of stay for medical/surgical inpatients. Three generations of American studies were defined according to the rigorousness of the methodology. Eighty-nine percent of all studies with sample sizes greater than 110 and 75% of the prospective, rigorously controlled, American studies found a significant association between psychiatric comorbidity and increased length of stay.

Immunohistological expression of p53 in primary pT1 transitional cell bladder cancer in relation to tumour progression.

Objective: To determine whether p53 expression is a marker of tumour progression in superficially invasive (pT1) transitional cell carcinoma of the bladder.

Patients And Methods: The immunohistochemical status of the p53 protein in 28 pT1 primary bladder cancers was determined on frozen tissue and archival paraffin block sections using three primary antibodies (CM-1, PAB1801 and D07). The findings were compared with the patients' progress.

A specific DNA-binding protein activated by ionizing radiation in normal cells and constitutively present in ataxia telangiectasia cells.

Exposure of mammalian cells to ionizing radiation gives rise to a complex series of changes. This response is characterized by the induction of a variety of genes and the activation of pre-existing proteins. We describe here activation of a specific DNA-binding protein by ionizing radiation.

Ionizing radiation and cell cycle progression in ataxia telangiectasia.

Exposure of mammalian cells to ionizing radiation causes delay in normal progress through the cell cycle at a number of different checkpoints. Abnormalities in these checkpoints have been described for ataxia telangiectasia cells after irradiation. In this report we show that these abnormalities occur at different phases in the cell cycle in several ataxia telangiectasia lymphoblastoid cells.

Combined peribulbar injection and blunt cannula infiltration for vitreoretinal surgery.

Seventy-six patients undergoing combined peribulbar and direct intraconal infiltration local anesthesia for vitreoretinal surgery were prospectively evaluated. Forty-six patients had local anesthesia with a combination of lidocaine 2% and bupivacaine 0.5%; in 30 patients, a combination of lidocaine 2% and prilocaine 1% was used.

Radiosensitivity in ataxia-telangiectasia: anomalies in radiation-induced cell cycle delay.

A number of anomalies have been described in the progression of ataxia-telangiectasia (AT) cells through the cell cycle post-irradiation. Some uncertainty still exists as to whether AT cells show increased or reduced division delay after exposure to ionizing radiation. We have attempted to resolve the apparent inconsistencies that exist by investigating the effects of radiation on AT cells at various stages of the cell cycle.

Remarkable sequence relatedness in the DNA encoding the major outer membrane protein of Chlamydia psittaci (koala type I) and Chlamydia pneumoniae.

DNA encoding the major outer membrane protein (MOMP) of the koala type-I strain of Chlamydia psittaci (pathogen responsible for blindness and infertility in koalas) was cloned and sequenced. Comparison with momp gene sequences from other chlamydial species revealed a remarkable degree of homology (> 97%) with that of the human pathogen, Chlamydia pneumoniae. In comparison, the sequence only shared 75% DNA sequence homology with other C.

Butyrate induced apoptosis in lymphoid cells preceded by transient over-expression of HSP70 mRNA.

In addition to inducing differentiation in several cell types sodium butyrate is cytotoxic to lymphoid cells and causes apoptosis in HL-60 cells. We report here that butyrate treatment of the Burkitt's lymphoma cell line BL-30 causes cell death by apoptosis, as established by nuclear changes and DNA fragmentation. The kinetics of induction of apoptosis by butyrate revealed a considerably delayed response in comparison to that observed with heat treatment.

Accumulation of HL-60 leukemia cells in G2/M and inhibition of cytokinesis caused by two marine compounds, bistratene A and cycloxazoline.

The effects on the cell cycle of two biologically active compounds, bistratene A and cycloxazoline, from the marine ascidian Lissoclinum bistratum were studied in HL-60 human leukemia cells using flow cytometry. Both compounds were shown to cause an apparent accumulation of cells in the G2/M phase. This effect was shown to be both time- and dose-dependent.

Is surgery for proliferative vitreoretinopathy justifiable?

Surgery for proliferative vitreoretinopathy (PVR) may require prolonged procedures often with limited improvement in visual function. Forty-seven consecutive patients who had PVR surgery in one eye had a case note review to assess anatomical re-attachment rate and improvement in visual acuity. All patients had at least 3 clock-hours of grade C PVR membrane.

Ionizing radiation and UV induction of p53 protein by different pathways in ataxia-telangiectasia cells.

Cell cycle anomalies have been described in ataxia-telangiectasia cells after exposure to ionizing radiation. A recent report demonstrates that cells from these patients lack the ionizing radiation-induced increase in p53 protein seen in controls. We report here that an ionizing radiation-induced p53 response is reduced and/or delayed in cells from four ataxia-telangiectasia complementation groups.

Diagnosis and pharmacotherapy of conduct disorder.

1. There are few double-blind, placebo-controlled studies of the drug treatment of conduct disorders in children and adolescents. 2.

Isolation of a cDNA clone, encoding the ribosomal protein S20, downregulated during the onset of apoptosis in a human leukaemic cell line.

In this report we describe the isolation, by differential screening, and characterization of a cDNA clone downregulated fivefold in association with the induction of apoptosis in the human leukaemic cell line CEM C7. DNA sequence analysis identified this clone as representing the gene encoding the S20 ribosomal protein. Interestingly, the expression of the S20 mRNA was downregulated early during the induction of apoptosis in this model system, prior to the onset of DNA fragmentation and other morphological changes associated with cell death, suggesting some degree of involvement of this particular gene in the biochemical events that occur during the onset of cell death.

Radiation-activated DNA-binding protein constitutively present in ataxia telangiectasia nuclei.

We have recently described the appearance of a specific DNA-binding protein in nuclei from human cells exposed to ionizing radiation which was not detected in nuclear extracts from unperturbed cells (Singh, S. P., and Lavin, M.

Comparison of type I and type II Chlamydia psittaci strains infecting koalas (Phascolarctos cinereus).

The native Australian marsupial Phascolarctos cinereus, otherwise known as the koala, is prone to infection by the obligate intracellular parasite Chlamydia psittaci, which causes ocular 'pink eye' and urogenital 'dirty tail' diseases. Several chlamydial DNA probes to both chromosomal and plasmid sequences were used to type by Southern blot analysis 51 samples taken from wild and captive koalas from habitats on the eastern seaboard of Australia as far apart as Queensland and Victoria. Two types of C.

Recombinant viral vaccines for enzootic bovine leucosis.

Recently published studies on the development and use of recombinant vaccinia virus (VV) vaccines incorporating either the complete envelope (env) gene or only a fragment of the env gene consisting of the coding sequence for the env glycoprotein 51 (gp51) and part of gp30 of the bovine leukaemia virus (BLV) are described. It has been reported that vaccination of sheep with recombinant VV vaccines containing the complete env gene appears to protect sheep against challenge infection with BLV. The evidence for this protection is based on the lack of persistence of high titres of anti-gp51 antibodies compared with unvaccinated BLV infected controls, on the enhanced CD4 proliferative responses to specific BLV gp51 synthetic peptides in the vaccinated sheep, and on the inability to detect BLV pro-virus by polymerase chain reaction in the vaccinated sheep after 4 months following challenge infection compared with continual detection in unvaccinated sheep over a 16 month trial period.

Immuno-dot blot as a rapid diagnostic method for detection of chlamydial infection in koalas (Phasolarctos cinereus).

The sensitivity and specificity of an immunoscreening test for anti-chlamydial antibodies in koala (Phasolarctos cinereus) serum were determined after the adsorption of non-specific antibodies. The results of the test were compared with complement fixation tests, tissue culture, gene probe analysis and dot blot immunoscreening for host-borne chlamydial antigen. The immunoscreening test was the most sensitive test for the identification of chlamydial infection in koala serum samples, furthermore it was rapid, taking approximately 16 hours to complete, and inexpensive.

Spontaneous hypertensive reactions with monoamine oxidase inhibitors.

Despite long-standing concerns over hypertensive reactions, monoamine oxidase inhibitors (MAOIs) have grown in popularity and are now used in a variety of psychiatric disorders. The risk of hypertensive episodes is less than 1%. This is most likely the result of careful dietary instructions and prudent prescribing of concomitant medications.