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Biomedical subjects

J Lever

Publications and source records attributed to J Lever.

30 records · Page 2Linked to original sources

Clinical significance of primitive reflexes in Alzheimer's disease.

STUDY OBJECTIVE: To establish the relationship between cognition, behavior, function, and clinical characteristics on the one hand, and the presence of primitive reflexes (PR) (pout, snout, palmomental and grasp) in patients with Alzheimer's disease (AD). DESIGN: Cross-sectional survey. SETTING: Secondary care geriatric practice specializing in the assessment of cognitive impairment. SUBJECTS: 136 consecutive patients presenting with AD. MEASUREMENTS: PR were assessed in standardized fashion by a single clinician. Cognitive function was measured using the Standardized Mini-Mental Status Examination, activities of daily living (ADL) and instrumental activities of daily living (IADL) were measured using the Lawton scale, and behavior was measured using the Behavioural Problem Checklist. RESULTS: There was no difference in age or duration of dementia in those with and without PR, nor was there any difference in cognitive function. Despite this, patients with PR showed a greater degree of functional limitation and dysfunctional behavior. There was also a higher incidence of rigidity, gait abnormalities, and apraxia in patients with PR. CONCLUSIONS: Patients with primitive reflexes had more severe impairment in ADL function and dysfunctional behavior for an equal level of cognitive function.

Activities of Daily Living↗

Malignant cell autolysis caused by intracytoplasmic liberation of lysosomal enzymes.

An ultrastructural study of the action of peptidoglycans on malignant lymphocytes was made. Glycans acted upon lysosomes labilizing and rupturing the lysosomal membrane. Lysosomal enzymes were discharged directly into the cell cytoplasm. Nucleus, mitochondria and all organelles were digested in situ, resulting in a completely structureless cell. Finally, cancerous cells disintegrated by the detachment of cytoplasmic fragments.

Animals↗

Eye injuries associated with 'war games'.

Eye injuries sustained by 4 patients who took part in 'war games' (in which young men shoot at each other with pistols powered by compressed carbon dioxide and firing latex rubber bullets filled with non-toxic paint) are described. In 3 cases the injuries were severe, including traumatic cataract, and 1 of these patients has a permanent macula scar with vision reduced to 6/36. Although eye protection is recommended, it was found that in the 'battle situation' combatants did not always follow regulations. Attention is drawn to the seriousness of disregarding the need for correct protective glasses.

Adolescent↗

Purine and pyrimidine nucleotides in some mutant human lymphoblasts.

To study the role of purine ribonucleotides as possible regulators of the rate of de novo purine biosynthesis in living human cells, we measured intracellular ribonucleotide concentrations by high-pressure liquid chromatography in a series of cloned human lymphoblast mutants selected by resistance to 8-azaguanine, in which the severity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficiency could be correlated with increases in the rate of de novo purine biosynthesis and increases in intracellular concentrations of phosphoribosyl pyrophosphate (PP-ribose-P). Compared with appropriate normal controls, intracellular purine ribonucleotide concentrations were not reduced in HGPRT-deficient lymphoblasts but there were striking increases in intracellular concentrations of some pyrimidine nucleotides and nucleotide sugars which appeared to be related to the degree of the deficiency. Similar changes were found in lymphoblasts from a Lesch-Nyhan boy. These data support the hypothesis that the accelerated rate of purine biosynthesis in HGPRT-deficient cells result from increases in intracellular PP-ribose-P concentration and not from changes in intracellular purine ribonucleotide concentrations. The possibility that the abnormality of pyrimidine nucleotide metabolism results from coordinate regulation of purine and pyrimidine biosynthesis by PP-ribose-P was not substantiated by measurement of rates of pyrimidine synthesis and experimental elevation of intracellular concentrations of PP-ribose-P after incubation of cells with inorganic phosphate.

Adenine Nucleotides↗

Purine and pyrimidine nucleotide concentrations in cells with decreased hypoxanthine-guanine-phosphoribosyltransferase (HGPRT) activity.

1. In order to investigate the role of purine ribonucleotides in the regulation of de novo purine synthesis in living human cells deficient in HGPRT, intracellular ribonucleotide concentrations have been measured in HGPRT lymphoblasts, fibroblasts and erythrocytes and in appropriate HGPRT controls by high pressure liquid chromatography. 2. Purine Purine ribonucleotide concentrations were not reduced in HGPRT cells, supporting the hypothesis that accelerated purine biosynthesis de novo results from increased availability of PP-ribose-P and not from altered feedback regulation by purine ribonucleotides in HGPRT deficient cells. 3. Striking increases in intracellular concentrations of some pyrimidine nucleotides and nucleotide sugars were detected in HGPRT lymphoblasts and erythrocytes, but not in fibroblasts. 4. The possibiiity that this abnormality of pyrimidine metabolism might result from coordinate regulation of purine and pyrimidine synthesis de novo by PP-ribose-P was not substantiated by measurements of rates of pyrimidine synthesis and experimental elevation of intracellular concentrations of PP-ribose-P following incubation of cells with inorganic phosphate.

Cell Line↗

Components of histidine transport: histidine-binding proteins and hisP protein.

The high-affinity (K(m) = 3 x 10(-8) M) transport system for histidine in Salmonella typhimurium has been resolved into three components: J, K, and P. J, which is a histidine-binding protein released by osmotic shock, is specified by the hisJ gene: hisJ mutants lack the binding protein and are defective in histidine transport. Another class of mutants-dhuA, which is closely linked to hisJ-has five times the normal level of binding protein and has an increased rate of histidine transport. P, which is a protein specified by the hisP gene, is required for J binding protein to be operative in transport. hisP mutants, though defective in transport, have normal levels of J binding protein. K, a third transport component, works in parallel to J, and also requires the P protein in order to be operative in transport. A second histidine-binding protein has been found but its relation to K is unclear. hisJ, dhuA, and hisP have been mapped and are in a cluster (near purF) on the S. typhimurium chromosome.

Biological Transport↗

Lesbians' sexual history with men: implications for taking a sexual history.

BACKGROUND: Health care providers may not solicit a comprehensive sexual history from lesbian patients because of provider assumptions that lesbians have not been sexually active with men. We performed this study to assess whether women who identify themselves as lesbians have a history of sexual activities with men that have implications for receipt of preventive health screening. OBJECTIVE: To convey the importance for health care providers to know their patients' sexual history when making appropriate recommendations for preventive health care. METHODS: A survey was printed in a national news magazine aimed at homosexual men, lesbians, and bisexual men and women. The sample included 6935 self-identified lesbians from all 50 US states. The outcomes we measured were respondents' number of lifetime male sexual partners and partners during the past year, their lifetime history of specific sexual activities (e.g., vaginal intercourse, anal intercourse), their lifetime condom use, and their lifetime history of sexually transmitted diseases. RESULTS: Of respondents, 77.3% had 1 or more lifetime male sexual partners, 70.5% had a lifetime history of vaginal intercourse, 17.2% had a lifetime history of anal intercourse, and 17.2% had a lifetime history of a sexually transmitted disease. Exactly 5.7% reported having had a male sexual partner during the past year. CONCLUSION: These findings reinforce the need for providers to know their patients' sexual history regardless of their reported sexual orientation, especially with regard to recommendations for Papanicolaou smears and screening for sexually transmitted diseases.

Adult↗

Impaired student performance in the clinical setting. A constructive approach.

A challenge for even the most seasoned faculty member is dealing with a student who arrives for clinical experience in an impaired state. Little guidance is available for faculty regarding protocol for the immediate removal of an unfit student from the clinical setting or for subsequent actions aimed at helping the student constructively address the problem. The authors provide guidance to faculty for the development of a policy to address issues pertaining to the impaired student.

Absenteeism↗