The umuDC locus of Escherichia coli is required for most mutagenesis by UV and many chemicals. Mutations in E. coli umuDC genes cloned on pBR322-derived plasmids were isolated by two methods. First, spontaneously-arising mutant umuDC plasmids that failed to confer cold-sensitive growth on a lexA51(Def) strain were isolated by selection. Second, mutant umuDC plasmids that affected apparent mutant yield after UV-irradiation in a strain carrying umuD+C+ in the chromosome were isolated by screening hydroxylamine-mutagenized umuD+C+ plasmids. pBR322-derived umuD+C+ plasmids inhibited the induction of the SOS response of lexA+ strains as measured by expression of din::Mu dl(lac Ap) fusions but most mutant plasmids did not. Mutant plasmids defective in complementation of chromosomal umuD44, umuC36, or both were found among those selected for failure to confer cold-sensitivity, whereas those identified by the screening procedure yielded mostly mutant plasmids with more complex phenotypes. We studied in greater detail a plasmid, pLM109, carrying the umuC125 mutation. This plasmid increased the sensitivity of lexA+ strains to killing by UV-irradiation but was able to complement the deficiencies of umuC mutants in UV mutagenesis. pLM109 failed to confer cold-sensitive growth on lexA(Def) strains but inhibited SOS induction in lexA+ strains. The effect of pLM109 on the UV sensitivity of lexA(Def) strains was similar to that of the parental umuD+C+ plasmid. The mutation responsible for the phenotypes of pLM109 was localized to a 615-bp fragment. DNA sequencing revealed that the umuC125 mutation was a G:C----A:T transition that changed codon 39 of umuC from GCC----GTC thus changing Ala39 to Val39. The implications of the umuC125 mutation for umuDC-dependent effects on UV-mutagenesis and cell survival after UV damage are discussed.

Alleles↗

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Age-related decline in MRI volumes of temporal lobe gray matter but not hippocampus.

The effect of normal aging on the volume of the hippocampus and temporal cortex was assessed cross-sectionally with quantitative Magnetic Resonance Imaging (MRI) in 72 healthy men, spanning 5 decades of the adult age range (21 to 70 years). Neither the hippocampal nor cortical white matter volumes were significantly correlated with age. By contrast, left and right temporal lobe gray matter volumes, exclusive of the hippocampal measures, each decreased with age (p < 0.01). Volumes of temporal lobe sulcal CSF and the ventricular system (temporal horns and lateral and third ventricles) significantly increased with age. Measures of verbal and nonverbal working memory showed age-related declines and were related to enlargement of the three ventricular regions, which may be indicative of age-related atrophy of the adjacent cortex but not the hippocampus, at least up to age 70 years.

Adult↗

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Neuropsychiatric aspects of Parkinson's disease.

Parkinson's disease (PD), a disorder characterized by movement abnormalities, is frequently complicated by psychiatric syndromes. Psychiatric assessment of the PD patient requires familiarity with the motor and cognitive aspects of PD, the various effects of antiparkinsonian medications, and how these relate to mental status changes and psychiatric phenomena. This review describes the various motor and nonmotor features of PD and focuses on the differential diagnosis of affective disorders in PD and their treatment.

Cognition Disorders↗

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The psychiatric perspectives of epilepsy.

Psychiatric conditions occur frequently in epilepsy, and their manifestations are diverse. Evaluation and management require knowledge of disease processes relevant to epilepsy and to psychiatry, as well as the role of other factors that affect the expression of psychiatric illnesses: behaviors, temperament, cognition, and life events. This article describes a comprehensive approach for addressing psychiatric issues in epilepsy patients.

Anticonvulsants↗

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A technique for routine calibration of thermoluminescent dosimeters in the diagnostic energy range.

Four different techniques for calibrating lithium fluoride thermoluminescent dosimeters were compared at two beam qualities in the diagnostic energy range. The techniques included in-air, saturation backscatter, and Bureau of Radiological Health (BRH) test stand geometry with and without an ionization chamber. The results indicate that there are no statistical differences between any of the calibration techniques evaluated. Hence, the technique using the BRH test stand with an ionization chamber is a simple and reproducible calibration procedure which may be used in a routine diagnostic radiology quality assurance program.

Fluorides↗

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Olanzapine for the treatment of psychosis in patients with Parkinson's disease and dementia.

Psychotic symptoms are a common complication in Parkinson's disease with dementia. The authors conducted an open-label 6-week trial of olanzapine preceded by a placebo lead-in in five subjects with Parkinson's disease, mild to moderately severe dementia, and psychosis. Four of the subjects terminated the trial early because of worsening motor function, sedation, or paranoia. There was no improvement in psychotic symptoms, and functional abilities declined significantly. Olanzapine appears to be poorly tolerated in patients with Parkinson's disease, psychotic symptoms, and dementia.

Aged↗

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Developing standards in palliative care.

Palliative care is an area of nursing that demands special skills and deserves standards of excellence. Standards are vital for the monitoring of patient care. Standards ensure that all staff are aware of the level of care to be delivered. Palliative care should be given to all patients who are dying, not just those with cancer. Before standards can be created, a philosophy of care must be written. Time limits must be set and adhered to.

Humans↗

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Creating the optimum environment for pressure area care.

Pressure area care is often thought to be only 'skin deep' but this does not fulfil the philosophy of holistic patient care. Nurses, as the pivot of the multidisciplinary team, must fully assess each patient's needs and implement care based on this assessment, thereby creating the optimum environment for pressure area care.

Humans↗