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Biomedical subjects

D R Anderson

Publications and source records attributed to D R Anderson.

At least 217 records · Page 12Linked to original sources
PubMed1987

Dupuytren's disease in women: evaluation of long-term results after operation.

A study of the long-term results after operation on 66 women (83 hands) with Dupuytren's disease showed that women are twice as likely as men to have a postoperative flare reaction. Why a flare reaction develops is uncertain. In this study, patients who had a carpal tunnel release at the time of operation for treatment of Dupuytren's disease or those who had an extensive fasciectomy, as opposed to removal of only the contracted tissue, were more apt to have a flare reaction. In addition, after operation, moderate or severe loss of finger flexion occurred in 35% of hands without a flare reaction and in 76% of those who had a flare reaction. This suggests that women having an operation for treatment of Dupuytren's disease are apt to have a worse result than men.

Aged↗
PubMed1987

The response of retinal vasculature to angiotensin.

A retinal arterial constriction was produced in anesthetized cats with a continuous transvitreal infusion of angiotensin I or angiotensin II (Ile-5). Constriction of vessels near the infusion cannula tip occurred over a range of angiotensin II concentrations from 10(-9) to 10(-4) molar, and was reversibly blocked by a ten-fold excess of the competitive antagonist saralasin. Constriction did not occur in response to angiotensin I if angiotensin-converting enzyme was blocked with Captopril. Control infusions of saline did not elicit a contraction of the retinal arteries. Severe axonal and inner retinal damage and necrosis occurred when angiotensin II produced a prolonged vasospasm, but not after infusion with control solutions, or when-constriction caused by angiotensin was brief.

Angiotensin I↗
PubMed1987

Attentional inertia reduces distractibility during young children's TV viewing.

The longer a look at TV is maintained, the conditional probability that it will be further maintained rapidly increases for about 15 sec, after which it increases slowly. This increase in the conditional probability of maintaining a look is called "attentional inertia." An external audiovisual distractor stimulus was presented during 3- and 5-year-olds' TV viewing. The distractor was less effective in eliciting a head turn from the TV if it was presented after a look at the TV had been continuously maintained for at least 15 sec. If a head turn to the distractor following such a maintained look did occur, moreover, its reaction time was significantly increased. Parallel effects were found for the nonviewing pauses between looks. The results provide evidence of increasing attentional engagement as a look at TV is maintained.

Arousal↗
PubMed1987

Adrenergic alpha 1 and alpha 2 binding sites are present in bovine retinal blood vessels.

Bovine retinal vessels have sites that specifically bind 3H-p-aminoclonidine (3H-PAC) with an apparent dissociation constant of 0.12 nM and a capacity of binding of 0.15 pmol/g. In addition, these vessels have 3H-prazosin binding sites bearing a dissociation constant of 5 nM and a binding capacity of 5 pmol/g. To understand the implications for retina-optic nerve vascular physiology and pathophysiology, studies of the exact location of the binding sites, the bioavailability of the adrenergic agonists, and the physiological responses to receptor stimulation in both normal and pathological states are required. The neural elements of the retina also have binding sites for 3H-PAC with an apparent dissociation constant of 0.38 nM in larger quantities (6.7 pmol/g tissue) than in the vascular elements. There are also binding sites for 3H-prazosin in a lower amount than in the vascular fraction (3 pmol/g tissue) with a dissociation constant of 2.4 nM. These sites are presumably related to the use of norepinephrine and dopamine as neurotransmitters by retinal neurons.

Animals↗
PubMed1987

Angiotensin binding sites in bovine and human retinal blood vessels.

Blood vessels isolated from bovine and human retinas have sites that specifically bind 3H-angiotensin II (3H-Ag II) with an apparent dissociation constant (Kd) of 14 nM and a capacity of binding (Bmax) of 0.82 pmol/g. The binding sites for 3H-Ag II appear to be influenced by guanine nucleotides (GTP) and cations (Mg2+ and Na+) in a way that resembles angiotensin II receptors in other tissues. The physiologic effect of blood-borne or locally-formed angiotensin II on retinal blood flow remains to be defined.

Angiotensin II↗
PubMed1986

Young children's recall and reconstruction of audio and audiovisual narratives.

It has been claimed that the visual component of audiovisual media dominates young children's cognitive processing. This experiment examines the effects of input modality while controlling the complexity of the visual and auditory content and while varying the comprehension task (recall vs. reconstruction). 4- and 7-year-olds were presented brief stories through either audio or audiovisual media. The audio version consisted of narrated character actions and character utterances. The narrated actions were matched to the utterances on the basis of length and propositional complexity. The audiovisual version depicted the actions visually by means of stop animation instead of by auditory narrative statements. The character utterances were the same in both versions. Audiovisual input produced superior performance on explicit information in the 4-year-olds and produced more inferences at both ages. Because performance on utterances was superior in the audiovisual condition as compared to the audio condition, there was no evidence that visual input inhibits processing of auditory information. Actions were more likely to be produced by the younger children than utterances, regardless of input medium, indicating that prior findings of visual dominance may have been due to the salience of narrative action. Reconstruction, as compared to recall, produced superior depiction of actions at both ages as well as more constrained relevant inferences and narrative conventions.

Child↗
PubMed1986

Television viewing at home: age trends in visual attention and time with TV.

The TV-viewing behavior of 99 families with young children was videotaped by automated time-lapse recording equipment placed in homes for 10-day periods. The 99 families comprised 460 individuals from infants to 62 years of age. Time-sample analyses of 4,672 hours of recordings indicated that the TV-viewing room contained no viewers 14.7% of the time that the TV was on. There were no age trends in time spent with television. Percent visual attention to television increased greatly across the preschool years, leveled off at about 70% during the school-age years, and declined in adulthood. Men looked at the TV more than women. There were no significant correlations between time spent with TV and percent of visual attention to TV. The increase in visual attention to television during the preschool years is consistent with the theory that TV program comprehensibility is a major determination of attention in young children.

Adolescent↗
PubMed1986

Changes in metabolite levels and morphology of teleost ventricular myocytes due to hypoxia, ischaemia, and metabolic inhibitors.

Since fish hearts are resistant to the effects of hypoxia, comparison of the effects of hypoxia and ischaemia on fish and mammalian hearts may lead to better understanding of ischaemic injury in mammalian hearts. The ultrastructure and levels of ATP, creatine phosphate, and lactic acid were examined in hearts obtained from largemouth bass. Bass hearts were subjected to conditions of normoxia, ischaemia, hypoxia, and hypoxia in the presence of fluoride and cyanide. ATP levels remained stable during hypoxia and ischaemia, but fell during hypoxia in the presence of fluoride or fluoride plus cyanide. Changes in creatine phosphate and lactic acid indicated ATP was produced during hypoxia and ischaemia by glycolysis, by rephosphorylation from creatine phosphate, and by oxidative phosphorylation with oxygen obtained from myoglobin or the atmosphere. Ultrastructural changes were found similar to those reported in ischaemic mammalian heart, consisting of inter- and intracellular swelling, glycogen depletion, and mitochondrial alterations. Comparison of metabolic rates between fish and mammalian hearts suggests the lower rate in fish hearts may be the chief factor which permits stable ATP levels during hypoxia and ischaemia, and thus provides resistance to these conditions.

Adenosine Triphosphate↗
PubMed1985

Arylphorin from Manduca sexta: carbohydrate structure and immunological studies.

The major hemolymph protein in the last larval stage of Manduca sexta is a hexameric glycoprotein, arylphorin (Mr = 450,000). Sodium dodecyl sulfate polyacrylamide gel electrophoresis of purified arylphorin reveals the presence of two subunits, A1 and A2. Both subunits are glycosylated and have apparent Mr = 77,000 and 72,000, respectively. Pronase digestion of arylphorin yielded a single major glycopeptide. 250 MHz NMR spectroscopy of arylphorin glycopeptide revealed a Man9GlcNAc2 oligosaccharide structure similar to that observed in mammalian glycoproteins. Endoglycosidase-H treatment of arylphorin was employed to remove covalently linked carbohydrate residues. The carbohydrate removal lowered the apparent Mr of subunits A1 and A2 to 72,000 and 69,000, respectively, indicating that the difference in arylphorin subunit size is not due to levels of glycosylation. Immunoblotting experiments with anti-arylphorin antiserum and Bombyx mori storage proteins indicated cross reactivity with the corresponding arylphorin of this insect. Preparation of subunit A2 monospecific antibodies, followed by immunoblotting of arylphorin showed a close immunological relationship between subunits A1 and A2.

Animals↗
PubMed1985

Relationship between reversible acetylcholinesterase inhibition and efficacy against soman lethality.

Carbamate pretreatment (45% inhibition, reversible), combined with therapy, protected rats from soman-induced lethality [The Pharmacologist 23, 224 (1981)]. The present study was done to see if less than 45% inhibition protects and to see if reversible acetylcholinesterase (AChE) inhibition and efficacy against soman lethality are correlated. At 30 min pre-soman, guinea pigs and rats received (im) either pyridostigmine (Py) or physostigmine (Ph) to inhibit whole blood AChE from 10 to 70%; at 1 min post-soman (sc), they received (im) atropine (16 mg/kg)/2-PAMCl (50 mg/kg) and mecamylamine (0.8 mg/kg)/atropine (16 mg/kg), respectively. Protective ratios (PRs) were computed and they ranged from 3.1 to 7.7 for guinea pigs and from 1.8 to 2.4 for rats. In guinea pigs the PRs for Py + therapy were roughly similar to those of Ph + therapy. In both species at 30 min after im injection of Py and Ph, a linear relationship was found between percentage of whole blood AChE inhibition and ln dosage of carbamate. Positive correlation (p less than 0.05) was found between the degree of reversible AChE inhibition by pretreatment, coupled with therapy, and efficacy against soman lethality. The present data indicate that inhibition levels as low as 10% may provide some protection.

Acetylcholinesterase↗
PubMed1985

A clinical, fluorescein angiographic, and electron microscopic correlation of cystoid macular edema.

Electron microscopic findings in an eye removed from a woman who had biomicroscopic and angiographic signs of cystoid macular edema occurring in association with a peripheral choroidal melanoma disclosed evidence that the anatomic basis for the biomicroscopic and angiographic changes was the polycystic expansion of the extravascular compartment of the retina by serous exudate and not, as previously reported, edema of the Mueller's cells.

Aged↗
PubMed1985

Laser iridotomy vs surgical iridectomy. Have the indications changed?

The number of laser iridotomies in 1982 was more than four times the annual rate of surgical iridectomies performed before the laser was in common use at the Bascom Palmer Eye Institute, Miami. No single reason accounts for the increase. Only a minority of the increase is due to a 32% increase in our outpatient volume, a backlog of individuals with borderline indications who had not undergone surgery, or the number of iridotomies performed prophylactically for asymptomatic narrow angles. The proportion of eyes treated for each of several classic indications (acute attacks, chronic angle closure with pressure elevation or synechiae, aphakic pupillary block, etc) remained the same. However, eyes with acute attacks and their fellow eyes had iridotomy more promptly and more often with the availability of laser. In addition, the laser was applied earlier in the course of chronic angle closure. We believe that the increased use of an easy, low-risk procedure represents an improvement in the quality of care.

Adult↗
PubMed1985

Application of microcomputers to the interpretation of high-resolution nuclear magnetic resonance spectra of asparagine-linked oligosaccharides: evaluation of high-mannose structures.

A microcomputer program for determining primary oligosaccharide structures by high-resolution nuclear magnetic resonance is reported. The program uses the data base obtained from spectra of model compounds reported in the literature. A number of high-mannose-type asparagine-linked glycopeptide spectra containing tabulated chemical shifts measured at room temperature were tested to determine the ability of the computer to correctly assign carbohydrate units into a complete structure. High-mannose structures ranging from five to nine oligomannosyl units were completely and unambiguously analyzed to give complete structural assignments. The computer program will also resolve glycopeptide mixtures. The method provides investigators with a useful tool for accurately evaluating nuclear magnetic resonance spectra and should greatly facilitate the complicated and time-consuming evaluation of microheterogeneity in samples commonly isolated from biological systems.

Asparagine↗
PubMed1985

Major carbohydrate structures at five glycosylation sites on murine IgM determined by high resolution 1H-NMR spectroscopy.

Mouse myeloma immunoglobulin IgM heavy chains were cleaved with cyanogen bromide into nine peptide fragments, four of which contain asparagine-linked glycosylation. Three glycopeptides contain a single site, including Asn 171, 402, and 563 in the intact heavy chain. Another glycopeptide contains two sites at Asn 332 and 364. The carbohydrate containing fragments were treated with Pronase and fractionated by elution through Bio-Gel P-6. The major glycopeptides from each site were analyzed by 500 MHz 1H-NMR and the carbohydrate compositions determined by gas-liquid chromatography. The oligosaccharide located at Asn 171 is a biantennary complex and is highly sialylated. The amount of sialic acid varies, and some oligosaccharides contain alpha 1,3-galactose linked to the terminal beta 1,4-galactose. The oligosaccharides at Asn 332, Asn 364, an Asn 402 are all triantennary and are nearly completely sialylated on two branches and partially sialylated on the triantennary branch linked beta 1,4 to the core mannose. The latter is sialylated about 40% of the time for all three glycosylation sites. The major oligosaccharide located at Asn 563 is of the high mannose type. The 1H-NMR determination of structures at Asn 563 suggests that the high mannose oligosaccharide contains only three mannose residues.

Amino Acids↗
PubMed1985

Estimates of young children's time with television: a methodological comparison of parent reports with time-lapse video home observation.

Accurate information on behavior of young children at home is crucial to the study of child development. The present study compared parent diaries of 5-year-old children's time spent with television to concurrent automated time-lapse video observations. In addition, a number of control groups were employed to assess the effects of observational equipment in the homes. The sample consisted of 334 mostly white middle-class families, of whom 106 had observational equipment installed. Results indicated no systematic subject selection of families who were willing to have observational equipment as compared to the controls. In addition, there were no differences in reported viewing behavior between the observed families and controls. Of 3 types of parent estimates of 5-year-old TV viewing, concurrent diaries correlated best with video observation (r = .84) and produced a very small absolute mean time error. Direct parent estimates of typical time spent viewing produced smaller correlations and large overestimates as compared with diaries.

Child↗