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Biomedical subjects

G Brown

Publications and source records attributed to G Brown.

At least 343 records · Page 19Linked to original sources
PubMed1987

A monoclonal antibody recognizes a human nuclear protein resembling Xenopus oocyte nucleoplasmin.

The monoclonal antibody 10BG2 (IgG3) was derived from a mouse immunized with human pre B cells. In immunofluorescence studies the antibody revealed a human nuclear-associated determinant, which in interphase cells was entirely restricted to the nucleus. In metaphase cells 10BG2 antigen was detected throughout the cytoplasm with intensified staining at the periphery of chromosomes. 10BG2 antibody stained all human normal and transformed cells tested. In contrast, the antibody did not stain mouse 3T3 cells or Chinese hamster ovary (CHO) cells. Electrophoresis under denaturing and non-denaturing conditions revealed the 10BG2 antigen to be a 130 X 10(3) to 140 X 10(3) Mr protein with a subunit molecular weight of 29.5 X 10(3). This suggests the protein is at least a tetramer. On two-dimensional gels the 10BG2 antigen had a streaked appearance and separated into two isoelectric variants (pI5.2, 5.4). The protein was also shown to be phosphorylated and thermostable, and remained in solution at pH 3.6. 10BG2 antigen was highly soluble in aqueous buffers and co-migrated on non-denaturing gels with the nucleosome-assembly protein, nucleoplasmin, purified from Xenopus oocytes. The similarity of 10BG2 antigen to nucleoplasmin is discussed.

Animals↗
PubMed1987

Validation of the 24-hour dietary recall in preschool children.

The results of the current study indicate that data obtained by the dietary recall correlate highly with the children's weighed food intake if a parent or the primary caretaker providing the child's food responds to the interview. Meredith et al. found parents to be poor reporters of children's consumption outside the home. It is encouraging to note that parents can be reliable reporters of their children's food intake in the home environment. When errors did occur, they were errors in portion size, as 96% of foods eaten by the children were correctly identified by the parents. Parents under-reported only 4% of the time. This slight tendency to under-report is consistent with other reports of the validity of the 24-hour dietary recall. In younger children, parents appear to be reliable reporters of their children's in-home dietary intake. As children become older, they appear to be able to recall their own intake both within and outside the home. There are several possible explanations for these findings. First, several factors could have influenced the accuracy of parental reports of the child's intake during the day that we weighed foods. Because food was weighed in the homes, the parents undoubtedly attended more closely to their child's diet. Additionally, the dietary recalls were collected at the end of the day of observation. This was closer in time than most 24-hour recalls and may have reflected less memory decay than usual. Also, since our sample was primarily middle-class families who were well educated, the correspondence between actual vs. reported dietary intake may have been artificially enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)

Child Nutritional Physiological Phenomena↗
PubMed1986

Cathepsin B synthesis by the HL60 promyelocytic cell line: effects of stimulating agents and anti-inflammatory compounds.

Cathepsin B synthesis by the human HL60 promyelocyte cell line was investigated by immunohistochemistry and by the assay of the enzyme in cell lysates using a fluorimetric substrate. HL60 cells were shown to produce cathepsin B in response to treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA). Intracellular levels of cathepsin B and immunohistochemical staining of the enzyme were related to time in culture with increasing concentrations of TPA from 1 nmol/1 to 8.0 nmol/1. Synthesis of cathepsin B was associated with TPA-induced phagocytic activity of cells in culture, expression of alpha-naphthyl acetate esterase and reduced cell division. Cathepsin B production was, therefore, related to differentiation of the HL60 promyelocytes into mature macrophage-like cells. Cathepsin B activity in HL60 cell lysates was significantly increased by incubation of the cells with 10 micrograms/ml endotoxin (lipopolysaccharide) from Escherichia coli, but not carrageenan. The production of cathepsin B by TPA-induced HL60 cells was significantly reduced by 0.25 mumol/1 dexamethasone and the non-steroidal anti-inflammatory compound 4-(6-methoxy-2-naphthyl)-butan-2-one but not by indomethacin. The HL60 promyelocytic cell line is a useful model for the study of factors affecting proteinase synthesis by human mononuclear phagocytes.

Anti-Inflammatory Agents↗
PubMed1986

Timer: a new objective measure of consultation content and its application to computer assisted consultations.

As part of the research into the effect in the consultation of the use of a computer to prompt opportunistic preventive care a valid, objective, and practical measure of the consultation process was required. After a review of the alternative methods the Time Interval Medical Event Recorder (Timer) was developed, its reliability tested, and applied to 93 control consultations and 49 computer assisted consultations. Timer records, every five seconds, four consultation events: the problems being dealt with, the physical activity, the verbal activity, and the secondary tasks being attempted. Timer showed that control consultations lasted an average of 6 minutes 58 seconds. The doctors spent 35% of their time on administration, and patients and doctors were both conversational for just 33% of the consultation. Giving information was the most common verbal activity (48% of the duration of the consultation) with silence accounting for 21% of the time. When the computer was used the average consultation was longer, at 7 minutes and 46 seconds. The doctor's contribution to the consultation appeared to have increased. Patient centred speech fell from 36% in controls to 28% of the duration of the consultation when the computer was used, while doctor centred speech rose from 30% to 34.5%. Secondary tasks (exploring patient concepts, education, management sharing, and prevention) were attempted during 28% of the control consultations and 40% of the computer consultations. This was accounted for by the increase in prevention (p less than 0.001). Timer is a reliable and practical tool for researching the consultation, and though it has shown validity in detecting differences between consultations that use a computer and those that do not, further applications are required to establish its full value.

Diagnosis, Computer-Assisted↗
PubMed1986

A quantitative estimate of the contribution made by various receptor categories to the depolarizations evoked by some excitatory amino acids in the olfactory cortex.

A study has been undertaken to assess the percentage contributions made by N-methyl-D-aspartate (NMDA), kainate and quisqualate receptors to the composite depolarizations evoked by L-cysteate, L-cysteinesulphinate, L-homocysteate and S-sulpho-L-cysteine in the rat olfactory cortex slice. The percentage contribution made by NMDA receptors, which was quantified by measuring the reduction in agonist responses in the presence of the highly selective NMDA receptor antagonist 2-amino-5-phosphonopentanoate (0.1 mM), was: L-homocysteate, 73%; S-sulpho-L-cysteine, 65%; L-cysteate, 42% and L-cysteinesulphinate, 30%. Responses mediated by NMDA, kainate and quisqualate receptors were abolished by a 'desensitization' procedure involving repeated application of a mixture containing high concentrations of the selective agonists followed by perfusion of the non-selective receptor antagonist cis-2,3-piperidine dicarboxylate (5 mM). Following this procedure, responses to L-homocysteate and S-sulpho-L-cysteine were almost abolished and simple calculation gave the contribution of kainate plus quisqualate receptors to the agonist responses as: L-cysteinesulphinate, 46%; L-cysteate, 34%; S-sulpho-L-cysteine, 28% and L-homocysteate, 23%. However, approximately 24% of the composite depolarizations evoked by L-cysteate and L-cysteinesulphinate was mediated by a mechanism not involving NMDA, kainate or quisqualate receptors, neither did it reflect possible electrogenic uptake of the amino acids nor an interaction with 2-amino-4-phosphonobutyrate receptors. It is suggested that this fraction of the depolarizations evoked by L-cysteate and L-cysteinesulphinate might be due to a non-receptor-mediated release of K+ or, perhaps, to activation of an as yet unidentified receptor category.

Amino Acids↗
PubMed1986

Redistribution of protein kinase C during mitogenesis of human B lymphocytes.

G0 human tonsillar B-lymphocytes were stimulated to divide by the polyclonal mitogen Staphylococcus Aureus Cowan strain 1 (SAC) and by the combined use of 12-O-tetradecanoyl phorbol-13-acetate (TPA) and the calcium ionophore ionomycin. The activities of protein kinase C, which requires Ca++ and phospholipid as co-factors, and a proteolytically cleaved form of this enzyme (protein kinase M), which is independent of calcium and phospholipid control, were determined in soluble and particulate fractions obtained from activated B cells. Treatment of G0 B cells with SAC or TPA together with ionomycin caused redistribution of protein kinase C from the soluble to the particulate fraction where the 80,000-Dalton protein kinase C was cleaved to give rise to a 50,000-Dalton form of the kinase which was also found in the cytoplasm. These data suggest that redistribution and proteolytic cleavage of protein kinase C are key signal transduction events in B cell mitogenesis.

B-Lymphocytes↗
PubMed1986

Differentiation of depressive disorders from generalized anxiety by the Beck Depression Inventory.

The Beck Depression Inventory (BDI) was administered to 35 outpatients diagnosed according to the DSM-III as primary generalized anxiety disorders and 101 outpatients diagnosed as primary major-depression and dysthymic disorders. A backward stepwise-discriminant analysis revealed that Sadness and Loss of Libido were the only two symptoms that meaningfully distinguished between the two groups. The depressed patients were sadder and complained of more loss of libido than did the anxious patients. It was concluded that the BDI is a powerful tool for differentiating the depressive from generalized anxiety disorders.

Adult↗
PubMed1986

Scanning fluorometer for the rapid assessment of pyridine nucleotide and flavoprotein fluorescence changes in tissues in vivo.

This paper describes a scanning fluorometer which produces images in real time of the distribution of pyridine nucleotide or flavoprotein fluorescence at the surface of tissues in vivo. The basic difference between this device and others reported in the literature is that fluorescence changes at any selected point within the image can be quantified as they occur. We suggest that the apparatus has potential application in those areas of surgery where vascular replacement or repair is required and where it would be advantageous to have an immediate measure of the cellular response to a return of blood flow.

Animals↗
PubMed1986

Expression of a 215,000-dalton nuclear envelope protein decreases during cell maturation.

The monoclonal antibody AGF2.3 identifies a nuclear envelope protein expressed at high levels in most transformed cell lines and weakly expressed in or absent from normal tissues and primary cell cultures. Here we report that expression of AGF2.3 antigen relates to the maturation status of cells. When HL60 cells were induced to mature loss of AGF2.3 antigen correlated with the appearance of neutrophils in culture. Acute myeloid leukaemia cells were intensely labelled by AGF2.3 antibody whereas chronic myeloid leukaemia cells were weakly reactive. Staining of tonsil epithelium showed a progressive loss of antigen during epithelial cell maturation. High levels of AGF2.3 antigen in most permanent cell lines suggest that such lines represent transformation of immature cells.

Antibodies, Monoclonal↗
PubMed1986

Swallowing food without chewing; a simple way to reduce postprandial glycaemia.

1. The degree to which disruption by mastication affects the glycaemic response to four different carbohydrate foods was investigated in healthy human volunteers; each food was eaten by six subjects. 2. Subjects ate meals of sweetcorn, white rice, diced apple or potato on two occasions; on one occasion they chewed the food thoroughly, on the other occasion they swallowed each mouthful without chewing it. 3. When the foods were chewed the postprandial blood glucose levels rose to levels which varied according to the food ingested. 4. Swallowing without chewing reduced the glycaemic response to each food, achieving a similar effect as administration of viscous polysaccharides or 'slow-release' carbohydrates.

Adult↗
PubMed1986

Calcofluor white detection of fungi in cytopathology.

Calcofluor/Cellufluor (CFW) binds to fungal cell walls and causes them to fluoresce blue-green when illuminated with UV light. Retrospective and prospective studies were made to determine if CFW could be added to the Papanicolaou (PAP) stain procedure without altering diagnostic cytopathologic features while still allowing fungi to be identified. The retrospective study included 136 cytology specimens that were designated positive for fungus by PAP stain; these were stained with a 0.1% aqueous solution of CFW and examined by fluorescent microscopy. The overall agreement between the two methods in the detection of fungi was 90.4%. The incorporation of CFW into the PAP stain was tested at various points in the PAP stain sequence; optimum results were obtained when CFW was introduced after acid eosin. A total of 197 random, sequentially accessioned cytology specimens were stained with the PAP/CFW combination in the prospective study. The results indicate that detection of fungi by a combination of regular light and fluorescent microscopy was far more effective than was examination for the organisms by light microscopy alone.

Benzenesulfonates↗
PubMed1986

Presence of 3-fucosyl-N-acetyllactosamine shown by monoclonal antibody AGF 4.48 in Reed-Sternberg cells.

A series of 50 specimens of Hodgkin's disease and 10 of reactive follicular hyperplasia were examined by means of indirect immunoperoxidase staining with a monoclonal antibody AGF 4.48: this is known to bind to 3-fucosyl-N-acetyllactosamine, which, in particular, is expressed by granulocyte series cells. Most Reed-Sternberg and many Hodgkin's cells were labelled by the antibody after pretreatment with neuraminidase. Routinely processed paraffin wax embedded sections proved suitable for staining. The findings were comparable with those reported by others with monoclonal antibodies to various other granulocyte markers. This technique is of potential diagnostic value.

Antibodies, Monoclonal↗