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Biomedical subjects

C R Taylor

Publications and source records attributed to C R Taylor.

At least 271 records · Page 15Linked to original sources
PubMed1982

The detection of estrogen receptors in gynecologic tumors using immunoperoxidase and the dextran-coated charcoal assay.

The dextran-coated charcoal receptor assay for demonstrating functional estrogen and progesterone receptors was used to evaluate the receptor content of gynecological tumors. An immunocytochemical method, the immunoperoxidase antiperoxidase method, that may detect estrogen receptors, was also employed on the same specimens utilizing sections from formalin-fixed paraffin embedded blocks. The results by the two methods were compared and were correlated with the state of differentiation of the tumors. According to the dextran-coated charcoal method, two cases of well differentiated endometrial adenocarcinoma were strongly positive for both estradiol and progesterone receptors, and three moderately differentiated cases contained lesser amounts of both types of receptors. Six cases of undifferentiated adenocarcinoma ranged from no detectable receptors to very high values, while of five cases of squamous cell carcinoma of the cervix, only two were positive for estradiol receptors by the dextran-coated charcoal method. Staining of tissue sections from these same cases using the immunoperoxidase method, demonstrated a positive correlation to the dextran-coated charcoal assay for estrogen receptors. The Dextran-coated charcoal method is presently being used clinically as a screening measure for statistical probability of a patient's response to hormone therapy. The degree of positive correlation shown here suggests that use of the immunoperoxidase method may have further potential for diagnostic and clinical use, and merits further investigation.

Adenocarcinoma↗
PubMed1982

Distribution of fiber types in locomotory muscles of dogs.

The distribution of Type I and Type II fibers, as determined from histochemical estimation of myofibrillar ATPase activity, was studied within and among the locomotory muscles of the forelimb, trunk, and hindlimb of three mongrel dogs. All Type II fibers had high oxidative capacities as estimated from the histochemical assay for reduced nicotinamide adenine dinucleotide tetrazolium reductase, so they were not further divided into subpopulations. Furthermore, Type I and Type II fibers had similar oxidative potentials as indicated by both histochemistry and biochemistry. Type I fiber populations ranged between 14% and 100% in the muscles sampled. The highest percentages of Type I fibers were found in deep muscles of physiological extensor groups in the arm and thigh that serve to resist gravity (antigravity muscles) when the dog is in the quadrupedal standing position. More superficial muscles in these same groups had fewer Type I fibers. The patterns of Type I fiber distribution among muscles in the antigravity groups of the forearm and leg were the opposite of those in the arm and thigh, with the more superficial muscles of the distal limb segments having more Type I fibers than the deeper muscles. In all limb segments, muscle groups that do not serve to resist gravity did not show as much intermuscular variation. Type I fiber populations in these muscles did not exceed 50%. A stratification of fiber types also existed within muscles, both in extensor and flexor groups, with the deeper portions of the muscles having more Type I fibers than the more superficial portions.

Adenosine Triphosphatases↗
PubMed1982

Immunoperoxidase technique in diagnosis of oral pemphigus vulgaris: an alternative method to immunofluorescence.

Five cases of oral pemphigus vulgaris, diagnosed on the basis of clinical, histopathologic, and immunopathologic criteria, were selected. Sections were stained with the peroxidase antiperoxidase (PAP) technique of immunocytochemical staining. The findings correlated well with those reported by direct immunofluorescence demonstrating the same intercellular substance (ICS) pattern of staining. Because this staining technique is applied to routinely processed and paraffinized tissue, it may be of particular value to the oral pathologist who often receives formalin-fixed material before the need for immunopathologic studies is recognized. In addition, interpretation does not require specialized microscopy and tissue sections can be stored and retrieved for retrospective study.

Fluorescent Antibody Technique↗
PubMed1982

Intravenous pirbuterol.

Pirbuterol was given intravenously to nine normal men to determine the hemodynamic effects of intravenous injection of this rather selective beta 2-adrenoceptor agonist. Pirbuterol induced marked improvement of the echocardiographic (percent change in the dimension of the minor axis of the left ventricle during systole, ejection fraction, and velocity of left ventricular circumferential fiber shortening) and systolic time interval (preejection period interval, preejection period/left ventricular ejection time) indices of ventricular performance. The increase in stroke volume was indicated by elevation of systolic blood pressure and widening of pulse pressure. Vascular beta 2-receptor agonist effects were indicated by the fall in diastolic and mean systemic blood pressure and marked reduction in derived systemic vascular resistance. Dose-related positive chronotropic properties were observed without dysrhythmias. There was a good direct correlation between mean plasma pirbuterol concentration and dose. Because of the reported efficacy of oral doses, the direct relationship between plasma concentration and dosage, the positive inotropic properties, and the peripheral vasodilating effects of pirbuterol, investigation of the intravenous form of the drug in patients with severe decompensated low-output congestive heart failure seems warranted.

Adult↗
PubMed1982

Energetics and mechanics of terrestrial locomotion.

This review addresses a simple question: How do muscles use the energy they consume during terrestrial locomotion? Using a comparative approach, it was found that the mass-specific rate of metabolic energy consumption changes by more than ten-fold with body size, while the mass-specific rate at which the muscles performed mechanical work did not change at all. It was also found that the rate of metabolic energy consumption increased linearly with speed, while the rate at which muscles performed mechanical work increased curvilinearly with speed (oc V1.53). We conclude from these observations that the rate at which animals consume metabolic energy during terrestrial locomotion is not determined by the rate at which their muscles perform mechanical work. Instead, the metabolic cost of generating muscular force over time (integral of F dt) appears to determine the metabolic cost of terrestrial locomotion. The cost of generating force increases with increasing speed and decreases with increasing body size in exactly the same manner as cost of locomotion. It is suggested that the metabolic cost of generating muscular force may be determined by the intrinsic velocity of shortening (i.e proportional to rates at which the cross-bridges between actin and myosin cycle) of the muscle motor units that are active during locomotion. Faster motor units are used both as animals increase speed and in equivalent muscles of smaller animals moving at the same speed. This suggestion is testable and future studies should determine whether or not it explains the higher costs of generating muscular force with increasing speed and decreasing body size.

Animals↗
PubMed1982

Immunoblastic sarcoma: morphologic criteria and the distinction of B and T cell types.

Immunologic concepts have facilitated the recognition within the histiocytic lymphoma group of the Rappaport classification of five diagnostic categories of lymphoma (follicular center cell lymphoma large cleaved and large non-cleaved types, immunoblastic sarcoma B cell type, immunoblastic sarcoma T cell type and 'true histiocytic lymphoma'). The first four of these 'large cell lymphomas' are closely related biologically and are difficult to distinguish histologically. This paper purports to examine the morphologic criteria employed in the differential diagnosis of these four large cell lymphomas in an objective manner, utilizing carefully prepared histologic sections from 24 cases of lymphoma that had been subjected to detailed B and T cell characterization by surface marker methods. 18 morphologic criteria were evaluated by four observers independently. The results show that reliable histologic distinctions can be made on histologic grounds in a proportion of cases only and that individual criteria show more overlap within diagnostic criteria than previously recognized. This is attributed in part to the close biologic relationship of these neoplasms. It is also recognized that the morphologic criteria are subtle and that the pathologist should have the advantage of auxiliary techniques--cytochemistry, immunohistology, surface marker techniques--to achieve reliable distinction of functional types within the diffuse histiocytic group of Rappaport.

B-Lymphocytes↗
PubMed1982

Double labeled-antigen method for demonstration of intracellular antigens in paraffin-embedded tissues.

A double "labeled-antigen" method has been developed for the simultaneous staining of both kappa and lambda light chains in fixed paraffin sections. The method is a two step procedure utilizing a mixture of antisera against kappa and lambda light chains in the first stage, followed by the addition of a mixture of kappa antigen labeled with horseradish peroxidase and lambda antigen labeled with alkaline phosphatase. The selection of substrates yielding reaction products of contrasting color enabled the observer to distinguish kappa-containing cells (brown) from lambda-containing cells (blue). Reactive plasma cells stained either pure brown (kappa) or clear blue (lambda) in a ratio of 1.5:1. Blood vessels containing serum immunoglobulins showed a mixed brown-blue reaction, as did the Reed-Sternberg cells of some cases of Hodgkin's disease. The advantages of this double labeled-antigen method over previously reported methods for achieving double staining are discussed.

Antigens↗
PubMed1982

A comparative study of the use of monoclonal antibodies using three different immunohistochemical methods: an evaluation of monoclonal and polyclonal antibodies against human prostatic acid phosphatase.

The use of immunohistochemical methods has been advocated for the detection and localization of prostatic acid phosphatase in paraffin sections of human prostate. This article explores the possible advantages of utilizing monoclonal antibodies in this method. Monoclonal antibodies, specific for human prostatic acid phosphatase, were integrated into three different immunohistochemical procedures. In the first method, a three-layer peroxidase-antiperoxidase (PAP) system was employed; the monoclonal antibody was followed by rabbit bridge antibody directed against mouse immunoglobulin and mouse PAP complex. The second method was a three-layer system utilizing biotin-labeled horse anti-mouse antibody as "bridge" antiserum between the primary monoclonal antibody and an avidin-biotin-horseradish peroxidase complex. The third method was a four-layer system; the monoclonal antibody was followed by rabbit anti-mouse serum, swine anti-rabbit immunoglobulin as the bridge antibody and rabbit PAP complex. It was found that some, but not all, monoclonal antibodies can be used for the detection of prostatic acid phosphatase in paraffin sections. The four-layer PAP method was found to be the most sensitive method of the three systems tested; however, the avidin-biotin method required the least amount of time. No significant difference in the quality of staining was observed between monoclonal antibodies and carefully absorbed conventional antiserum.

Acid Phosphatase↗
PubMed1982

Energetics and mechanics of terrestrial locomotion. I. Metabolic energy consumption as a function of speed and body size in birds and mammals.

This series of four papers investigates the link between the energetics and the mechanics of terrestrial locomotion. Two experimental variables are used throughout the study: speed and body size. Mass-specific metabolic rates of running animals can be varied by about tenfold using either variable. This first paper considers metabolic energy consumed during terrestrial locomotion. New data relating rate of oxygen consumption and speed are reported for: eight species of wild and domestic artiodactyls; seven species of carnivores; four species of primates; and one species of rodent. These are combined with previously published data to formulate a new allometric equation relating mass-specific rates of oxygen consumed (VO2/Mb) during locomotion at a constant speed to speed and body mass (based on data from 62 avian and mammalian species): VO2/Mb = 0.533 Mb-0.316.vg + 0.300 Mb-0.303 where VO2/Mb has the units ml O2 s-1 kg-1; Mb is in kg; and vg is in m s-1. This equation can be expressed in terms of mass-specific rates of energy consumption (Emetab/Mb) using the energetic equivalent of 1 ml O2 = 20.1 J because the contribution of anaerobic glycolysis was negligible: Emetab/Mb = 10.7 Mb-0.316.vg + 6.03 Mb-0.303 where Emetab/Mb has the units watts/kg. This new relationship applies equally well to bipeds and quadrupeds and differs little from the allometric equation reported 12 years ago by Taylor, Schmid-Nielsen & Raab (1970). Ninety per cent of the values calculated from this genera equation for the diverse assortment of avian and mammalian species included in this regression fall within 25% of the observed values at the middle of the speed range where measurements were made. This agreement is impressive when one considers that mass-specific rates of oxygen consumption differed by more than 1400% over this size range of animals.

Animals↗
PubMed1982

Energetics and mechanics of terrestrial locomotion. II. Kinetic energy changes of the limbs and body as a function of speed and body size in birds and mammals.

This is the second paper in a series examining the link between energetics and mechanics of terrestrial locomotion. In this paper, the changes in the kinetic energy of the limbs and body relative to the centre of mass of an animal (EKE, tot) are measured as functions of speed and body size. High-speed films (light or X-ray) of four species of quadrupeds and four species of bipeds running on a treadmill were analysed to determine EKE, tot. A mass-specific power term, EKE, tot/Mb was calculated by adding all of the increments in EKE during an integral number of strides and dividing by the time interval for the strides and body mass. The equations relating EKE, tot/Mb and speed were similar for all bipeds and quadrupeds regardless of size. One general equation for the rate at which muscle and tendons must supply energy to accelerate the limbs and body relative to the centre of mass seems to apply for all of the animals: E'KE, tot/Mb = 0.478 vg1.53 where E'KE, tot/Mb has the units W kg-1 and vg is ground speed in m s-1. Therefore, E'KE, tot/Mb does not change in parallel with the mass-specific rate at which animals consume energy (Emetab/Mb), either as a function of speed or as a function of body size.

Animals↗
PubMed1982

Energetics and mechanics of terrestrial locomotion. III. Energy changes of the centre of mass as a function of speed and body size in birds and mammals.

This is the third in a series of four papers examining the link between the energetics and mechanics of terrestrial locomotion. It reports measurements of the mechanical work required (ECM, tot) to lift and reaccelerate an animal's centre of mass within each step as a function of speed and body size during level, constant average speed locomotion. A force platform was used in this study to measure ECM, tot for small bipeds, quadrupeds and hoppers. We have already published similar data from large animals. The total power required to lift and reaccelerate the centre of mass (ECM, tot) increased nearly linearly with speed for all the animals. Expressed in mass-specific terms, it was independent of body size and could be expressed by a simple equation: ECM, tot/Mb = 0.685 vg + 0.072 where ECM, tot/Mb has the units of W kg-1 and vg is speed in m s-1. Walking involves the same pendulum-like mechanism in small animals as has been described in humans and large animals. Also, running, trotting and hopping produce similar curves of ECM, tot as a function of time during a stride for both the small and large animals. Galloping, however, appears to be different in small and large animals. In small animals the front legs are used mainly for braking, while the back legs are used to reaccelerate the centre of mass within a stride. In large animals the front and hind legs serve to both brake and reaccelerate the animal; this difference in mechanics is significant in that it does not allow the utilization of elastic energy in the legs of small animals, but does in the legs of large animals.

Animals↗
PubMed1982

Relationship between muscle force and muscle area showing glycogen loss during locomotion.

This experiment was designed to study the relationship between the cross-sectional area of rat skeletal muscle showing glycogen loss and the muscle forces exerted during exercise. Muscular force exerted by the extensors of the elbows and ankle was increased by 24% by loading rats with 24% of their body mass while running them on a treadmill at 30 m.min-1. VO2 increased by 24% and stride frequency was unchanged when the rats ran with loads. Cross-sectional areas of the elbow and ankle extensor muscles showing glycogen loss were compared from rats running with and without the load. We found a nearly direct proportionality between the changes in force and the changes in muscle area showing glycogen loss, i.e. when the force of the extensors was increased by 24%, the cross-sectional area of the elbow extensors showing glycogen loss increased by 28%, and that of the ankle extensor group increased by 24%. The more peripheral muscles in each group accounted for a greater proportion of the increase in cross-sectional area of the group showing glycogen loss (i.e. lateral and long heads of triceps brachii muscle accounted for 91% of the increase in the elbow extensor group, and gastrocnemius muscle accounted for 84% of the increase in the ankle extensor group). Most of the increases in muscle area showing glycogen loss occurred in fast-twitch-glycolytic fibres (84% in the elbow and 88% in the ankle). The data suggest that increasing muscle force requirements by 24% by loading resulted in proportional increases in cross-sectional area of muscles recruited to produce the force, i.e. that spatial recruitment primarily accounted for the elevation in force. The relatively greater increases in cross-sectional area showing glycogen loss of peripheral muscles within a group indicate the importance of studying whole groups of muscles when considering muscular recruitment patterns during exercise.

Animals↗
PubMed1982

Energetics and mechanics of terrestrial locomotion. IV. Total mechanical energy changes as a function of speed and body size in birds and mammals.

This is the final paper in or series examining the link between the energetics and mechanics of terrestrial locomotion. In this paper the kinetic energy of the limbs and body relative to the centre of mass (EKE, tot of paper two) is combined with the potential plus kinetic energy of the centre of mass (ECM, tot of paper three) to obtain the total mechanical energy (excluding elastic energy) of an animal during constant average-speed locomotion. The minimum mass-specific power required of the muscles and tendons to maintain the observed oscillations in total energy, Etot/Mb, can be described by one equation: Etot/Mb = 0.478 . vg 1.53 + 0.685 . vg + 0.072 where Etot/Mb is in W kg-1 and vg is in m s-1. This equation is independent of body size, applying equally as well to a chipmunk or a quail as to a horse or an ostrich. In marked contrast, the metabolic energy consumed by each gram of an animal as it moves along the ground at a constant speed increases linearly with speed and is proportional to Mb-0.3. Thus, we have found that each gram of tissue of a 30 g quail or chipmunk running at 3 m s-1 consumes metabolic energy at a rate about 15 times that of a 100 kg ostrich, horse or human running at the same speed while their muscles are performing work at the same rate. Our measurements demonstrate the importance of storage and recovery of elastic energy in larger animals, but they cannot confirm or exclude the possibility of elastic storage of energy in small animals. It seems clear that the rate at which animals consume energy during locomotion cannot be explained by assuming a constant efficiency between the energy consumed and the mechanical work performed by the muscles. It is suggested that the intrinsic velocity of shortening of the active muscle motor units (which is related to the rate of cycling of the cross bridges between actin and myosin) and the rate at which the muscles are turned on and off are the most important factors in determining the metabolic cost of constant-speed locomotion. Faster motor units are recruited as animals increase speed, and equivalent muscles of small animals have faster fibres than those of larger animals. Also, the muscles are turned on and off more quickly as an animal increases speed, and at the same speed a small animal will be turning muscles on and off at a much higher rate. These suggestions are testable, and future studies should determine if they are correct.

Animals↗
PubMed1982

Expression of HLA-DR antigens in human fetal pancreas tissue.

The expression of HLA-DR antigens in human fetal pancreas tissue was studied using four independently derived monoclonal antibodies recognizing nonpolymorphic HLA-DR antigens. Immunoperoxidase staining of frozen sections revealed numerous DR-antigen-positive cells. Two major cell types could be distinguished. Large, strongly DR-positive cells with dendritic morphology were distributed throughout the dendritic morphology were distributed throughout the pancreatic parenchyma and interstitial connective tissue. Dual staining of DR antigens and insulin using a two-color immunoperoxidase technique clearly showed that some of these DR-positive dendritic cells were located within and in close association with insulin-producing islets. Also observed as a regular feature of fetal pancreas tissue sections were large clusters of DR-positive cells with lymphoid morphology. Positive staining of many cells within these clusters with monoclonal antibodies against T-cell marker (Leu-1) and T-cell subset markers (Leu-2 and -3) supported their classification as lymphoid cells. In contrast, no positive staining with anti-T-cell antibodies was observed outside of lymphoid cell clusters, confirming the distinction between these cells and the DR-positive cells distributed throughout the pancreas. The presence of other DR-bearing cell types in fetal pancreas could not be excluded, but most endothelial cells appeared to be DR-negative. The demonstration of numerous DR-bearing cells associated with fetal pancreas tissue may require that we alter our views on DR-antigen ontogeny and develop new strategies for fetal pancreas transplantation.

Antibodies, Monoclonal↗
PubMed1982

Cytoplasmic as opposed to surface Ia antigens expressed on human peripheral blood lymphocytes and monocytes.

Peripheral blood leucocytes were examined for the presence of HLA-Dr or Ia-like antigen on the cell surface and in the cytoplasm. Surface staining of viable cell suspensions, using monoclonal anti-Ia antibody in both immunofluorescence and immunoperoxidase methods gave similar results. Using a newly developed immunoperoxidase double staining procedure, which stains the cells when either viable or fixed, both the surface and cytoplasm of the individual cells were labelled and examined. Twenty to thirty percent of the mononuclear cells were positive for Ia staining on the cell surface and in the cytoplasm. Morphologically these positive cells were identified as both lymphocytes and monocytes. A small percentage (5-9%) of these monocytes and lymphocytes consistently labelled only cytoplasmic Ia determinants. In contrast, only surface binding was observed with monoclonal antibodies recognizing T cell subpopulations. The ability to detect intracellular Ia antigenic determinants is of value in distinguishing stages of lymphocyte and monocyte development.

Antigens, Surface↗