Search PubMed⌕ Search

Biomedical subjects

M A Anderson

Publications and source records attributed to M A Anderson.

At least 127 records · Page 7Linked to original sources

Agreement between haemoglobin estimation and anaemia recognition card in assessment of anaemia in pregnant women.

Sensitivity and specificity of pallor signs were compared to haemoglobin determination for identifying nutritional anaemia in pregnant women. A total of 211 pregnant women were examined for signs of pallor using the anaemia recognition card, and their haemoglobin was determined by the cyanmethaemoglobin filter paper technique. The sensitivity of pallor signs in identifying severe nutritional anaemia in the population was fair, as 67 per cent of the pregnant women identified as anaemic by haemoglobin levels less than 8 g/dl were detected as anaemic by the presence of pallor signs. However, the specificity of the measure indicated that almost half of the pregnant women with haemoglobin level above 8 g/dl were misclassified as anaemic by presence of signs of pallor. Since the sensitivity and specificity of the pallor signs test are fairly low, the anaemia recognition card is an inefficient tool to be used to screen for severe cases of nutritional anaemia.

Anemia, Hypochromic↗

Singleness of action in the interactions of feeding with other behaviors in Hermissenda crassicornis.

Singleness of action in the interactions of feeding behavior with other behaviors was studied in Hermissenda crassicornis. In Experiment 1 withdrawal of the oral veil from a tactile stimulus was inhibited during feeding elicited by application of a mussel homogenate to hungry animals. Rolling-over behavior was also inhibited during feeding. When animals were satiated, thereby abolishing the feeding response to mussel homogenate, withdrawal occurred in the presence of the food stimulus; however, rolling-over behavior was still inhibited. In Experiments 2 and 3 it was demonstrated that spontaneous locomotion was also inhibited in hungry animals by food stimuli; however, satiated animals ignored the food stimulus and continued to locomote. Both biting behavior and the suppressive effect of food stimuli on locomotion were also observed in dissected anterior ends of Hermissenda, suggesting that the mechanisms underlying the interaction of feeding with other behaviors may be accessible to study in the nervous system of reduced preparations.

Animals↗

Physical and genetic localization of quinonoid dihydropteridine reductase gene (QDPR) on short arm of chromosome 4.

A portion of a cDNA clone corresponding to the 3' end of the human quinonoid dihydropteridine reductase (QDPR) mRNA was used as a probe to physically map the QDPR gene by analysis of somatic cell hybrid lines. The provisional assignment of QDPR to chromosome 4, based on expression of the human enzyme in hybrids, was confirmed. The gene was further regionally localized on the short arm to 4p16.1----4p15.1. This physical localization places QDPR in the same area of the genome that contains the defect causing Huntington's disease (HD). The QDPR probe revealed a restriction fragment length polymorphism with the enzyme BanII, permitting determination of its genetic proximity to D4S10, an anonymous DNA marker tightly linked to HD. QDPR is only loosely linked to D4S10, excluding any primary role for the gene in HD.

Animals↗

A somatic cell hybrid panel for localizing DNA segments near the Huntington's disease gene.

Thirty-four random DNA probes from the terminal half of the human chromosome 4 short arm were further localized within 4pter----p15.1. A panel of somatic cell hybrid lines defining six chromosomal regions within 4pter----p15.1 was constructed using human cell lines containing translocation or deletion chromosomes. The vast majority of the DNA sequences, 32 of 34 or 94%, mapped to the three most proximal regions comprising 4p16.1----4p15.1. Only two probes were localized distal to 4p16.1: one in the region 4p16.3----4p16.1 and one in 4p16.3. D4S10, a polymorphic DNA marker linked to the Huntington's disease defect, has previously been mapped to the terminal region of 4p with conflicting assignments to 4p16.1 and 4p16.3. Analysis of restriction fragment length polymorphisms demonstrated hemizygosity for D4S10 in a patient with Wolf-Hirschhorn syndrome resulting from an unbalanced translocation t(4;8)(p16.3;p23.1), supporting the 4p16.3 localization. Our panel of somatic cell hybrids provides a rapid method for mapping new probes to the same vicinity as that of D4S10. However, the relative paucity of such DNA segments identified here suggests that a more directed approach may be required to generate additional markers near the HD gene.

Animals↗

Comparison of clinical and objective methods of assessing trunk muscle strength--an experimental approach.

An objective method was used to evaluate the validity of the sit-up, prone trunk extension, and double leg lowering clinical tests. Normal men and women and patients with a history of backache served as subjects. The vast majority of the subjects were able to perform the Grade 1 level, which was the highest resistance imposed by the sit-up and prone extension tests. The double leg lower was superior to the other two clinical tests but was able to identify only broad differences in strength capability. In the main, the subjective clinical tests were poor discriminators and seemed to lack the range of resistance necessary to be definitively useful as methods of assessing trunk muscle strength and may not provide appropriate resistance for improving trunk muscle strength in most patients.

Adult↗

An enzyme-linked immunosorbent assay (ELISA) for in vitro pollen growth based on binding of a monoclonal antibody to the pollen tube surface.

An indirect method of quantifying in vitro pollen growth has been developed. This is based on the finding that a monoclonal antibody (PCBC3), which has a primary specificity for alpha-l-arabinofuranosyl residues, binds to the surface of in vitro grown pollen tubes of the ornamental tobacco, Nicotiana alata. This binding was quantified using an enzyme linked immunosorbent assay (ELISA). The method was used to determine the effects of 2-deoxy-d-glucose and nonanoic acid on in vitro pollen growth.

Journal Article↗

Inhibition of beta-lactamase synthesis in Staphylococcus aureus by minocycline.

The effect of minocycline on beta-lactamase synthesis in Staphylococcus aureus was examined. Some inhibition of synthesis was detectable in organisms exposed to 0.015 mg minocycline/litre (0.15 of the single cell MIC) and complete inhibition was observed at 0.05 mg drug/litre (0.5 MIC). In contrast, total cell protein synthesis was less susceptible to inhibition by minocycline. Although synthesis of beta-lactamase was inhibited by low concentrations of minocycline, benzylpenicillin and minocycline failed to show synergy when tested in a variety of combinations against penicillinase producing staphylococci. In fact, benzyl-penicillin did not influence the minocycline MIC, and in the majority of cases the same pattern was exhibited by minocycline i.e. it did not generally alter the penicillin MIC. This is an example of true indifference whereby each antibiotic behaves as if the other were not present. The results presented here are discussed in relation to the possibility of therapeutic control of beta-lactamase producing organisms by suppressing the level of enzyme produced.

Drug Synergism↗

Molecular basis of cell recognition during fertilization in higher plants.

The molecular basis of recognition between plant cells is incompletely understood. Some principles established for recognition between animal cells may well apply to plant cell recognition, although, in contrast to animal cells, plant cells are encased by cell walls that play an active role in plant cell-cell recognition. The interaction that controls fertilization in flowering plants involves recognition between pollen or pollen tubes and the female sexual tissues. In many flowering plant families, self-incompatibility (S) genes operate to prevent inbreeding. In plants that have gametophytically controlled self-incompatibility, recognition of common S alleles in pollen tube and style results in arrest of pollen tube growth within the style. Self-incompatibility therefore provides a model cell-cell recognition system that is genetically defined. We have taken two approaches to defining cell recognition involved in gametophytic self-incompatibility in Nicotianas alata. Firstly, we have established the major features of the pollen tube wall and the matrix of the style transmitting tissue that are in contact with the growing pollen tube. Secondly, we have established the nature of style glycoproteins that are associated with the S genotype and have initiated a program to clone the genes coding for the protein component of these glycoproteins. Analyses of the pollen tube are consistent with the major polymers being a (1----3)-beta-D-glucan (callose) and a (1----5)-alpha-L-arabinan. The pollen tube has two distinct layers: gold immunocytochemistry using a monoclonal antibody directed to terminal alpha-L-arabinosyl residues shows the binding is confined to the outer layers. The major component of the extracellular matrix of the style transmitting tissue is a family of proteoglycans, the arabinogalactan-proteins. A major glycoprotein that segregates with the S2 allele is present in extracts of mature styles. This component has a high pI (greater than 9.5) and an apparent molecular weight of 32 X 10(3). It is not present in extracts of immature styles of N. alata genotypes bearing the S2 allele, or in extracts from other organs of N. alata or styles of other members of the Solanaceae. The isolated glycoprotein is an effective inhibitor of in vitro pollen tube growth. This evidence suggests that the S2-associated glycoprotein is either the product of the S2 allele, or a gene closely associated with the S gene. We have prepared a cDNA library from styles of one genotype and are screening this library with mRNA from mature and immature styles.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

DNA markers for nervous system diseases.

Recombinant DNA technology has provided a vast new source of DNA markers displaying heritable sequence variation in humans. These markers can be used in family studies to identify the chromosomal location of defective genes causing nervous system disorders. The discovery of a DNA marker linked to Huntington's disease has opened new avenues of research into this disorder and may ultimately permit cloning and characterization of the defective gene.

Alleles↗

Separation of some neutral lipids by normal-phase high-performance liquid chromatography on a cyanopropyl column: ubiquinone, dolichol, and cholesterol levels in sheep liver.

The normal-phase high-performance liquid chromatographic separation of neutral lipids into molecular classes was carried out on a cyanopropyl (CN) column eluted with isopropanol in hexane. Cholesteryl, retinyl, and dolichyl esters, triglycerides and vitamin E, ubiquinone, dolichol, phytol, and cholesterol eluted as separate peaks with 0.05% isopropanol in hexane. Cholesterol, retinol, diglyceride, and monoglyceride eluted as separate peaks with 0.75% isopropanol in hexane. These separations could not be achieved on a silica gel column. The method was used to assay sheep liver ubiquinone, dolichol, and cholesterol levels, that were determined as 77, 108 and 1864 micrograms/g wet wt, respectively.

Animals↗

A high proportion of hybridomas raised to a plant extract secrete antibody to arabinose or galactose.

A high proportion of hybridomas, obtained from mice immunized with style extracts prepared from mature flowers of an ornamental tobacco, Nicotiana alata, secrete antibody to arabinogalactan protein (AGP). The specificity of the antibodies secreted by three cloned cell lines is primarily directed to beta-d-galactopyranose and alpha-l-arabinofuranose; antibodies from two cell lines preferentially bind beta-d-galactopyranose residues and antibodies from the other cell line preferentially bind alpha-l-arabinofuranose. As AGPs are components of most plant tissues and exudates, it is likely that attempts to raise monoclonal antibodies to other plant extracts will result in hybridomas producing antibodies to AGPs.

Journal Article↗