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Biomedical subjects

L Butler

Publications and source records attributed to L Butler.

At least 37 records · Page 2Linked to original sources
PubMed1988

Regulation of cellular and humoral immune responses to collagen type I or collagen type II.

We have investigated the characteristics of antigen-specific reductions in murine immune responses to rat collagen type I (R-CI), chick collagen type II (C-CII) or bovine collagen type II (B-CII). Intravenous pretreatment with the appropriate soluble collagen or collagen-coupled spleen cells led to the development of antigen-specific reduced immune responses, the former treatment being more effective than the latter. In the case of CII, pretreatment with R-CI or non-related antigens was ineffective. However, pretreatment with denatured bovine-CII, native bovine-CII or chick-CII led to immune hyporesponsiveness for either the homologous or heterologous CII molecule. A delayed development of the diminished immune responses was observed for the cell-mediated immune response (CMI), as measured by in vivo delayed-type hypersensitivity (DTH), in that no reduction was evident at Day 7 but a significantly decreased response was observed at Day 14. Collagen-specific IgG and IgM antibody responses were consistently reduced by the pretreatment and remained reduced during the study period. The antigen-specific hyporesponsive state was not sensitive to cyclophosphamide treatment and was not transferable with hyporesponsive spleen cells. Additionally, we have induced unresponsiveness to CII by treating mice with an antibody directed to T helper cells (GK1.5). This treatment led to profound reductions in CII CMI responses as well as CII antibody levels. However, this unresponsive state is not permanent and not transferable with spleen cells from treated mice. These two types of procedures, soluble B-CII i.v. or GK1.5 treatment, not only resulted in CII hyporesponsive states, but also produced delayed onset and decreased incidence of arthritis in the appropriate strains.

Animals↗
PubMed1988

Facing up to AIDS.

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Acquired Immunodeficiency Syndrome↗
PubMed1988

The effect of cigarette smoke, nicotine, and carbon monoxide on the permeability of the arterial wall.

The association between cigarette smoking and the development of atherosclerosis is well established, but the mechanism that makes cigarettes such a potent "risk factor" is not understood. There is normally a constant insudation of plasma macromolecules into the arterial wall. Fibrinogen and lipids are two of the large molecules involved in atherosclerosis. Therefore we studied the effect of cigarette smoke, nicotine, and carbon monoxide on the permeability of the canine arterial wall to 125I-labeled fibrinogen. The results show that inhaled cigarette smoke significantly and rapidly increases the permeability of the arterial wall to fibrinogen and that this effect can be produced with carbon monoxide alone but not with intravenous nicotine.

Animals↗
PubMed1987

Effect of carotid endarterectomy on cerebral blood flow and its response to hypercapnia.

Cerebral blood flow (CBF) was measured in 14 patients before carotid endarterectomy, 3 h after surgery and 2 days postoperatively using the intravenous xenon-133 technique. In 11 of the patients CBF was remeasured at 6 months and in 8 patients CBF and the response to hypercapnia (5 per cent CO2 in air) was measured pre-operatively and 6 months following surgery. All operations were performed using an intraluminal Javid shunt and internal carotid artery (ICA) 'stump' pressure was recorded. CBF measured at 3 h after endarterectomy revealed a postoperative cerebral hyperperfusion with significantly increased flows in both hemispheres. There was a significant correlation between carotid cross clamping time and ipsilateral hemispheric CBF increase which implied an ischaemic aetiology for the hyperperfusion and supported the routine use of an intraluminal shunt in carotid endarterectomy. Six months after surgery, CBF had returned to its preoperative value but reactivity to CO2 was significantly improved, which suggested that the operation had increased cerebral reserve.

Aged↗
PubMed1986

Diabetic BioBreeding/Worcester (BB/Wor) rats need not be lymphopenic.

The BB/Wor rat is an animal model of spontaneous autoimmune type I diabetes mellitus. Previous reports have emphasized the presence of lymphopenia in all diabetic and diabetes-prone BB rats. This manuscript reports the appearance of diabetes among three family lines of BB/Wor animals that were previously free of diabetes. Diabetic W-line rats are not lymphopenic and possess normal percentages of phenotypic T cell subsets. Hence the presence of lymphopenia is not obligatory for the occurrence of diabetes in BB/Wor rats.

Animals↗
PubMed1986

Characteristics of cellular immune responses to collagen type I or collagen type II.

We have examined the murine cell-mediated immune (CMI) response to collagens type I (CI) and type II (CII) as measured by in vivo delayed-type hypersensitivity responses. We have verified the histopathology and kinetics of the cell-mediated immune responses. Predominant cell-mediated responses were obtained 7, 10, or 14 days following immunization. A presumed antibody-mediated reaction was observed at later times (e.g., greater than 21 days following immunization). The CMI responses to the collagens show a strain-dependent relationship. For CI, the CMI response profile shows H-2b greater than or equal to H-2k = H-2q much greater than H-2d. For bovine CII, the response profile is H-2d greater than H-2b = H-2k = H-2q; the chick CII response profile is H-2q = H-2k greater than H-2b = H-2d, and in limited testing, only the H-2q strain could generate murine CII-specific cell-mediated immune responses. The CII-specific CMI response is cross-reactive with CII from several species of animals, but not with CI. Further, the collagen-specific CMI response can be elicited with certain cyanogen-bromide fragments of bovine CII. Finally, our study also demonstrates that there is a non-H-2-linked locus(i) involved in the development of CII-induced arthritis.

Animals↗
PubMed1986

Identification of two subtypes of HLA-DR2 by Southern blot analysis.

We studied the polymorphism of HLA-DR2 by Southern blot analysis. Genomic DNA from 12 DR2 positive unrelated individuals was digested separately with five restriction endonucleases, Bam HI, Eco RI, Eco RV, Hind III and Pvu II. Hybridizing restriction fragments were visualized using radiolabeled beta-chain cDNA probes homologous to the DR and DQ subregions of the HLA. The results in the present study demonstrate that the two subtypes of DR2, DR2.1 and DR2.2, as defined by serological and cellular (PLT) techniques can be identified by Southern blot analysis. These two subtypes were identifiable after cleaving genomic DNA with Bam HI and EcoRV. DR2.1 correlated with restriction endonuclease fragments at 2.8 kb (DR beta) and 6.6 kb (DQ beta) after Bam HI digest, while DR2.2 correlated with a 2.9 kb (DR beta) and a 2.6 kb (DQ beta) restriction fragment after Eco RV digest. In addition, inheritance of the restriction fragment lengths defining DR2.1 and DR2.2 were observed in two families. In contrast, no differences between DR2.1 and DR2.2 were observed with the restriction enzymes Eco RI, Hind III and Pvu II.

DNA Restriction Enzymes↗
PubMed1985

Assay of covalent intermediate of 5'-nucleotide phosphodiesterase.

We report a new procedure for isolating a covalent phosphoryl enzyme (diester) intermediate of bovine intestinal 5'-nucleotide phosphodiesterase. The convenience of the procedure makes it possible to determine effects of reaction conditions on the yield of covalent intermediate. Under optimum conditions, using [methyl-3H]deoxythymidine 5'-triphosphate as substrate, more than 50% of the enzyme is recovered as thymidylyl enzyme, a 10-fold increase in yield over the previous procedure (M. Landt and L. G. Butler, 1978, Biochemistry 17, 4130-4135). Yields of thymidylyl enzyme were maximal at pH 4, whereas optimum catalytic activity is observed at pH greater than 9.

Animals↗
PubMed1985

Heterogeneity of HLA-DR2: definition of two subtypes by serological and cellular techniques.

We have used the serological and cellular (PLT) techniques to investigate the heterogeneity of HLA-DR2. The serologic studies demonstrate that DR2 can be subdivided into two specificities based on the patterns of reactivity with the Ninth Workshop serum, 9w555. These two DR2 subtypes were also recognized by cellular assay utilizing PLTs generated between HLA-DR2, DQ-identical, DP-identical or incompatible individuals. The data, therefore, suggest the existence of two alleles of DR2, DR2.1 (long) and DR2.2 (short).

HLA-DR2 Antigen↗
PubMed1985

Heterogeneity of HLA-DR5: definition of two subtypes by the primed lymphocyte test.

We have used the serological and cellular (PLT) techniques to investigate the heterogeneity of HLA-DR5. The cellular studies suggested that DR5 can be subdivided into two specificities, DR5.1 and DR5.2. Three PLTs defined DR5.2 and one PLT recognized DR5.1. In serological assay, it is likely that DR5.1 could equal DRw12 and DR5.2 equal DRw11. Alternatively, it is possible that DRw11 can be further subdivided into two specificities, DR5.1 and DR5.2.

Antigens, Heterophile↗
PubMed1985

Amiodarone pulmonary toxicity. Chest radiography and CT in asymptomatic patients.

Two asymptomatic patients from a group of 30 being treated with the antiarrhythmic drug amiodarone developed roentgenographic pulmonary and pleural reactions. Computed tomography in one patient with an uncommon radiographic pattern of fuzzy nodules showed the spatial distribution of the parenchymal changes, as well as unrecognized pleural thickening. The disease in these asymptomatic patients was presumably detected on the periodic chest roentgenogram at an early stage because the changes disappeared after withdrawal of the drug. Periodic chest radiographs are recommended during amiodarone therapy and CT may be useful in evaluation of patients with unusual chest radiographic findings.

Aged↗
PubMed1985

Processing of form: further evidence for the necessity of attention.

Using the materials and general procedure described by Rock and Gutman (1981), 160 subjects were required to attend selectively to a series of 10 red or green outlines of two overlapping contours. Immediately afterwards, six groups of 20 subjects were administered various kinds of recognition tests involving attended, unattended, or new figures, and two groups of 20 were asked to provide affect ratings of the test stimuli. Consistent with the findings of Rock and Gutman in 1981, attended outlines were selected as old more often than unattended or new ones. Although some data in a single-stimulus condition suggested that the unattended forms were "discriminated negatively," this effect was not replicated with forced-choice testing. Over-all, there was little evidence that, on unattended forms, subjects were significantly more accurate, differentially confident or displayed more liking than on new ones. These results are interpreted as supporting the view that attention is required for the cognitive representation of form.

Attention↗
PubMed1985

The probability of tsetse acquiring trypanosome infection from single blood meal in different localities in Kenya.

The probability of tsetse, Glossina pallidipes, acquiring a trypanosome infection from a single blood meal was estimated in five localities on the Kenya coast which were selected for differences in habitat and host availability. The probability that one blood meal contained infective Trypanosoma congolense was 0.0077 in rural areas with domestic animals, 0.0019 in extensive areas of natural habitat with wild hosts and 0.0013 in an area with domestic animals under regular chemoprophylaxis. The respective probabilities for T. vivax were 0.0010, 0.0024 and 0.0021.

Age Factors↗
PubMed1977

Pathology on-call.

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Appointments and Schedules↗
PubMed1977

Recombination values and their errors.

Two four-point testcrosses comprising 87,000 tomato plants were grown and the data collected from 28 subgroups. Each subgroup consisted of 2,000 or 5,000 plants and should give a valid estimate of the three recombination values. The 28 values for each interval give more outlyers (23% are outside the 95% limits set by the standard deviation calculated by the binomial formula square root of p q/n) than would be expected by chance. If each subgroup was regarded as the control and the other groups tested against this, then 42% of the time the two subgroups would be significantly different. It is suggested that there are many cases in the literature where this comparison has been made and the significant difference wrongly ascribed to treatment. While the causes of these changes in recombination value are unknown and therefore uncontrollable, they must be anticipated in all such studies. Control and treatment must be replicated enough that chance extreme values will not be attributed to treatment.

Crosses, Genetic↗