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Biomedical subjects

C Gray

Publications and source records attributed to C Gray.

At least 37 records · Page 2Linked to original sources
PubMed2000

Two-dimensional map of the proteome of Haemophilus influenzae.

We have constructed a two-dimensional database of the proteome of Haemophilus influenzae, a bacterium of medical interest of which the complete genome, comprising about 1742 open reading frames, has been sequenced. The soluble protein fraction of the microorganism was analyzed by two-dimensional electrophoresis, using immobilized pH gradient strips of various pH regions, gels with different acrylamide concentrations and buffers with different trailing ions. In order to visualize low-copy-number gene products, we employed a series of protein extraction and sample application approaches and several chromatographic steps, including heparin chromatography, chromatofocusing and hydrophobic interaction chromatography. We have also analyzed the cell envelope-bound protein fraction using either immobilized pH gradient strips or a two-detergent system with a cationic detergent in the first and an anionic detergent in the second-dimensional separation. Different proteins (502) were identified by matrix-assisted laser desorption/ionization mass spectrometry and amino acid composition analysis. This is at present one of the largest two-dimensional proteome databases.

Databases, Factual↗
PubMed2000

Osteoclastic resorption of equine cranial and postcranial bone in vitro.

To address possible differences in the resorbability of cranial and postcranial bone, slices of equine frontal bone and leg (first phalanx or third metacarpus) were seeded with embryonic chick bone cells and cultured for 20-24h. After removing the cells and drying the specimens, the areas and volumes of more than 800 resorption pits in each set were measured using a video-rate reflection confocal microscope system. Relative mineralization densities were determined by quantitative electron backscattering analysis. The mean mineralization density was greater in the leg bone, but the mean depths for resorption pits in frontal bone were smaller (median volume/area ratios, experiment 1 and experiment 2: 1.98 microm frontal and 3.79 microm leg versus 2.70 microm and 4.20 microm, respectively; P < 0.0001, Mann-Whitney), even though the areas were greater in the frontal (medians, 286 microm2 and 324 microm2, versus 242 microm2 and 201 microm2; P < 0.0001). This study has shown a difference between cranial and postcranial equine bone in the shape and size of resorption pits formed in vitro. Overall, it has shown that cranial bone may be resorbed at least as readily as postcranial bone. This result is counter to the clinical impression that cranial bone has a greater staying power than postcranial bone when used as a grafting material.

Animals↗
PubMed2000

Intrusion errors in numerical transcoding by Alzheimer patients.

The errors made by brain-damaged patients when they attempt numerical transcoding tasks have recently been considered as a possible aid to early diagnosis of the disease. The transcoding errors of 20 Alzheimer's disease patients are described, and the incidence of each kind of error compared with norms from healthy subjects. Tegnér and Nybäck (Tegnér R, Nybäck H. "To hundred and twenty4our": a study of transcoding in dementia. Acta Neurologica Scandinavia 1990; 81: 177-178) reported that Alzheimer patients often express numerical information in a mixture of verbal and digital codes and Kessler and Kalbe (Kessler J, Kalbe E. Written numerical transcoding in patients with Alzheimer's disease. Cortex 1996; 32: 755-761) suggested that such intrusions of the source code into the target code may not only be largely absent from the responses of the healthy population, but also from the transcoding operations of patients with other kinds of brain damage, such as aphasia. It was found that intrusion errors occurred much more frequently in the transcoding protocols of some of the Alzheimer patients than they do in those of healthy subjects. On the other hand, they were entirely absent from the protocols of other Alzheimer patients. The implications of the findings for the early diagnosis of Alzheimer's disease are discussed, and the phenomenon of intrusion errors is considered in terms of some of the models of arithmetical processing that have been proposed.

Aged↗
PubMed2000

Necrotizing proctitis caused by Streptococcus pyogenes.

We report the case of a 65-year-old patient with peritonitis, septicaemia and toxic shock syndrome in whom the primary focus of infection was acute purulent proctitis with necrosis. Streptococcus pyogenes serotype T28R28 was isolated from blood culture and peritoneal pus. The patient recovered after a prolonged period of intensive therapy and four abdominal operations including anterior resection of the rectum. We believe this to be the first clinical description of streptococcal necrotizing proctitis.

Aged↗
PubMed2000

Clozapine, diabetes mellitus, weight gain, and lipid abnormalities: A five-year naturalistic study.

OBJECTIVE: The goal of this 5-year naturalistic study of patients treated with clozapine was to examine the incidence of treatment-emergent diabetes mellitus in relation to other factors, including weight gain, lipid abnormalities, age, clozapine dose, and treatment with valproate. METHOD: Data on age, gender, race, diagnosis, family history of diabetes, and age at clozapine initiation were collected from medical records of 82 outpatients with schizophrenia or schizoaffective disorder. Clozapine dose, data on use of valproate, and laboratory test results were recorded at 6-month intervals. RESULTS: The mean age at the time of clozapine initiation of the 82 patients was 36.4 years; 26.8% of the patients were women, and 91.5% were Caucasian. The mean baseline weight was 175.5 lb, and the mean body mass index was 26.9 kg/m(2). Thirty patients (36.6%) were diagnosed with diabetes during the 5-year follow-up. Weight gain, use of valproate, and total daily dose of clozapine were not significant risk factors for developing diabetes mellitus. Patients experienced significant weight gain that continued until approximately month 46 from initiation of clozapine. There was a nonsignificant increase in total serum cholesterol and a significant increase in serum triglycerides level. CONCLUSIONS: The results support the hypotheses that patients treated with clozapine experience significant weight gain and lipid abnormalities and appear to be at increased risk for developing diabetes.

Adult↗
PubMed2000

5-a-day Power Plus: process evaluation of a multicomponent elementary school program to increase fruit and vegetable consumption.

The 5-a-Day Power Plus program targeted multiethnic fourth- and fifth-grade students in 10 intervention and 10 control urban elementary schools in St. Paul, Minnesota, to increase fruit and vegetable consumption. The intervention included behavioral curricula in classrooms, parental involvement, school food service changes, and food industry support. Process evaluation was conducted by using surveys and classroom and lunchroom observations to assess the characteristics of teachers and food service staff, the degree the intervention was implemented as intended, and exteral factors that may have affected the program results. Results showed high levels of participation, dose, and fidelity for all of the intervention components, with the exception of parental involvement. The process evaluation findings help explain why the increase in fruit and vegetable consumption occurred mostly at school lunch and not at home. Future intervention research should focus on creating new and potent strategies for parental involvement and for increasing the appeal and availability of vegetables.

Child↗
PubMed2000

Automaticity, spelling, and second language learning.

This study investigated the relationship between a chronometric estimate of automaticity for the spelling of French words (Automaticity) and performance on four tests of French language attainment among a sample of Year 11 students of French as a foreign language. Fifty participants each completed a computerized test of French spelling and attainment tests in four aspects of French language learning: reading comprehension, writing fluency, oral fluency, and aural comprehension. Correlations were significant between Automaticity and performance on all four tests of French language attainment as well as on overall attainment.

Achievement↗
PubMed1999

Relation of TNF-related apoptosis-inducing ligand (TRAIL) receptor and FLICE-inhibitory protein expression to TRAIL-induced apoptosis of melanoma.

Past studies have shown that apoptosis mediated by TNF-related apoptosis-inducing ligand (TRAIL) is regulated by the expression of two death receptors [TRAIL receptor 1 (TRAIL-R1) and TRAIL-R2] and two decoy receptors (TRAIL-R3 and TRAIL-R4) that inhibit apoptosis. In previous studies, we have shown that TRAIL but not other members of the tumor necrosis factor family induce apoptosis in approximately two-thirds of melanoma cell lines. Here, we examined whether the expression of TRAIL-R at the mRNA and protein level in a panel of 28 melanoma cell lines and melanocytes correlated with their sensitivity to TRAIL-induced apoptosis. We report that at least three factors appear to underlie the variability in TRAIL-induced apoptosis. (a) Four of nine cell lines that were insensitive to TRAIL-induced apoptosis failed to express death receptors, and in two instances, lines were devoid of all TRAIL-Rs. Southern analysis suggested this was due to loss of the genes for the death receptors. (b) Despite the presence of mRNA for the TRAIL-R, some of the lines failed to express TRAIL-R protein on their surface. This was evident for TRAIL-R1 and more so for the TRAIL decoy receptors TRAIL-R3 and -R4. Studies on permeabilized cells revealed that the receptors were located within the cytoplasm and redistribution from the cytoplasm may represent a posttranslational control mechanism. (c) Surface expression of TRAIL-R1 and -R2 (but not TRAIL-R3 and -R4) showed an overall correlation with TRAIL-induced apoptosis. However, certain melanoma cell lines and clones were relatively resistant to TRAIL-induced apoptosis despite the absence of decoy receptors and moderate levels of TRAIL-R1 and -R2 expression. This may indicate the presence of inhibitors within the cells, but resistance to apoptosis could not be correlated with expression of the caspase inhibitor FLICE-inhibitory protein. mRNA for another TRAIL receptor, osteoprotegerin, was expressed in 22 of the melanoma lines but not on melanocytes. Its role in induction of apoptosis remains to be studied. These results appear to have important implications for future clinical studies on TRAIL.

Apoptosis↗
PubMed1999

Target controlled infusion of ketamine as analgesia for TIVA with propofol.

PURPOSE: To determine the accuracy of a target controlled infusion system for ketamine and to assess its suitability for the provision of analgesia when used in conjunction with a propofol infusion in spontaneously breathing patients. METHODS: Nineteen, adult, ASA I-III patients scheduled for elective surgery were studied. After premedication with 20 mg temazepam an appropriate plasma concentration of ketamine was selected and, when the target controlled infusion (TCI) system indicated that this had been achieved, anesthesia was induced and maintained using a propofol infusion. The plasma ketamine concentration was measured at predetermined intervals and cardiovascular and respiratory parameters recorded at 10 min intervals. Patients were reviewed in recovery and 24 hr postoperatively to assess the adequacy of their recovery and the presence of any undesirable side effects. RESULTS: The TCI system had a median performance error against predicted plasma concentrations of 18.9% (SE 2.5%) and a median absolute performance error of 23.3% (SE 2.3%). Divergence was 20.3% (SE 30.1%) and wobble was 12.9% (SE 2.1%). There was a mean decrease in arterial pressure of 6.4% (SD 19.7%) and a mean increase in heart rate of 4.3% (SD 17.4%). Little respiratory depression occurred and all patients made a rapid postoperative recovery with none describing unpleasant dreams or hallucinations. CONCLUSION: The TCI system provided a clinically acceptable degree of control of the plasma ketamine concentration although some further improvement should be possible by amending the pharmacokinetic model. Clinically the combination with a propofol infusion proved to be a satisfactory anesthetic technique.

Adolescent↗
PubMed1999

Pattern span: a tool for unwelding visuo-spatial memory.

Evidence showing that non-verbal short-term memory has distinct visual and spatial/sequential components is reviewed. A new test, The Visual Patterns Test (VPT), which was designed to measure short-term visual memory largely shorn of its spatio-sequential component, is described. Correlational studies of the VPT and the Corsi Blocks Test with healthy subjects and brain-damaged patients indicate a separation between visual and sequential abilities. This separation of function is supported by double dissociations shown by patients. Moreover, in a selective interference experiment, the VPT and the Corsi tests were found to show a double dissociation pattern of interference from visual and spatio sequential subsidiary tasks, respectively. The present results are discussed in relation to other findings in the literature, and it is concluded that non-verbal short-term memory can indeed be viewed as comprising distinct visual and spatio-sequential components. The VPT will be a useful neuropsychological instrument for measuring the visual component.

Adolescent↗
PubMed1999

Mnemonic training in older adults: effects of age, length of training, and type of cognitive pretraining.

OBJECTIVES: To improve performance with mnemonic techniques for remembering words and proper names. DESIGN: For word recall, a 2 x 2 factorial in which type of pretraining and length of training were between-subjects manipulations. For proper name recall, a two-group design in which type of pretraining was manipulated between subjects. SETTING: Community. PARTICIPANTS: 268 community-dwelling adults over the age of 55 years who wished to improve their memory. MEASUREMENTS: Recall of words and proper names both before and after training in mnemonics. INTERVENTION: Participants received a 2-week training course on two mnemonic techniques, the method of loci for words and a name association technique for proper names. RESULTS: There was no effect of the pretraining manipulation on proper name recall. For word recall, however, a multiple regression that included age indicated that the older-old participants benefited more from a combination of comprehensive pretraining and extended mnemonic training than did the younger-old. CONCLUSIONS: Increased training time coupled with a comprehensive pretraining regimen can improve the performance of the older-old in using mnemonics; this improved performance cannot be attributed solely to enhanced knowledge of the mnemonic.

Age Factors↗
PubMed1999

Media reviews

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Journal Article↗