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Biomedical subjects

R W Ogilvie

Publications and source records attributed to R W Ogilvie.

At least 19 recordsLinked to original sources
PubMed1999

Students' attitudes towards computer testing in a basic science course.

OBJECTIVES: The introduction of computerized testing offers several advantages for test administration, however, little research has examined students' attitudes toward computerized testing. This paper, reports the attitudes of 202 students in a first year cell biology and histology course toward computerized testing and its influence on their study habits over a three year period. DESIGN AND METHODS: Multiple choice and image-based extra credit examinations and summative image-based examinations have been successfully administered in the course. The results indicate that students readily accept computer exams and that their study habits were influenced in a positive manner by the computer administered extra-credit examinations. RESULTS: Our results provide further evidence that medical students like the use of computer administered examinations and that the examinations may actually accentuate the learning experience.

Attitude of Health Personnel↗
PubMed1999

Exercise stimulates neovascularization in occluded muscle without affecting bFGF content.

PURPOSE: This study was conducted to determine whether exercise-induced improvements in capillarity in muscle with peripheral arterial insufficiency (PAI) was accompanied by endothelial cell mitosis, and whether that response could be explained by changes in the expression of basic fibroblast growth factor (bFGF), a known mitogen. METHODS: After bilateral ligation of femoral arteries, Sprague-Dawley rats either remained sedentary or participated in a treadmill running protocol. Running time to exhaustion at each session was recorded. On days 1, 2, 3, 5, and 7 of the experimental period, trained-ligated and sedentary-ligated animals were euthanized, and segments of muscle from the gastrocnemius were obtained. Capillarity was determined with histochemistry, and endothelial cell mitotic activity (cell proliferation) was assayed via nuclear uptake of 5'-bromo-2'-deoxyuridine (BrdU), an analog of thymidine. Content of endogenous bFGF was assessed with immunoblotting techniques. RESULTS: Exercise training resulted in augmented function of PAI affected muscle as evidenced by a nearly threefold increase in running time until exhaustion. Trained-ligated muscle demonstrated significantly (P < 0.05) greater capillarity than sedentary-ligated muscle. Vascular remodeling elicited by exercise included the formation of new capillaries (angiogenesis) as indicated by enhanced endothelial cell proliferation at days 3, 5, and 7 of the study. However, exercise training did not alter the content of bFGF in occluded muscle. CONCLUSION: In muscle with PAI, exercise training improved functional capacity and capillarity. Angiogenesis was confirmed by the increased mitotic activity of endothelial cells. However, the content of bFGF, a potent angiogenic factor, was not altered. Thus, exercise-induced angiogenesis in PAI affected muscle is not dependent upon increased expression of endogenous bFGF.

Animals↗
PubMed1998

Exercise training enhances basic fibroblast growth factor-induced collateral blood flow.

This study evaluated whether daily exercise would enhance the peripheral collateral vessel development found in response to exogenous basic fibroblast growth factor (bFGF) infusion. After bilateral femoral occlusion, male Sprague-Dawley rats (approximately 325 g) received intra-arterial infusions of either bFGF (1 microg/day; n = 15) or carrier solution (n = 13) via osmotic pumps for 2 wk. Subgroups of each treatment were kept sedentary (cage activity) or trained by walking at 20 m/min at 15% grade, two times a day, 5 days/wk for 4 wk. Training markedly increased citrate synthase activity in the active muscle (P < 0.001). Muscle function and blood flows (85Sr microsphere) were evaluated using an isolated hindquarter perfused at 100 mmHg via the abdominal aorta. The significant increase in blood flow to the entire hindlimb in the sedentary animals, caused by bFGF infusion (P < 0.05), was further increased (P < 0.01) in the bFGF-trained group. The quantitatively largest increases in blood flows were observed in the collateral-dependent tissues of the distal hindlimb. Blood flows to the entire calf muscle group increased approximately 140% in carrier-trained (P < 0.001), approximately 180% in bFGF sedentary (P < 0.001), and approximately 240% in the bFGF-trained (P < 0.001) groups compared with the carrier sedentary group. The increases in collateral blood flow were functionally important, as improvements in calf muscle performance correlated with measured blood flows. Our results demonstrate that exogenous bFGF administration in combination with a moderate-intensity exercise program greatly increases collateral-dependent blood flow and improves muscle performance. That physical activity enriched the bFGF response is consistent with the hypothesis that hemodynamic factors are important contributors to collateral vessel enlargement.

Animals↗
PubMed1996

Basic fibroblast growth factor increases collateral blood flow in rats with femoral arterial ligation.

The potential for exogenous infusion of basic fibroblast growth factor (bFGF) to increase collateral blood flow to dependent tissue was quantified in adult male rats with peripheral arterial insufficiency. Occlusion of the femoral artery at a proximal site did not infringe on resting blood flow to the distal hindlimb muscle, but did remove the blood flow reserve. Blood flow to the hindlimb muscles was measured with radiolabeled microspheres using an isolated hindlimb preparation perfused in the descending aorta (Krebs-Henseleit bicarbonate, 5% albumin medium containing red blood cells [40% hematocrit]) at 100 mm Hg. Calf muscle blood flow changed modestly (approximately equal to 50%) with infusion of only the carrier (heparin/saline), increased markedly over the first 2 weeks of bFGF infusion (1 microgram/d into the femoral artery), but did not change further with infusion for 4 weeks. Waiting 2 weeks after 1 week of bFGF infusion did not further increase the intermediate improvement in blood flow. The improved collateral blood flow and increased muscle capillary density likely contributed to the enhanced muscle performance observed during nerve stimulation in situ. X-ray films of arterial casts identified an expansion of upper thigh vessels that likely served as collaterals. In animals with peripheral arterial insufficiency, short-term exogenous infusion of bFGF is effective at inducing vascular expansion that is sufficient to improve the flow reserve of dependent distal tissue and enhance muscle function. This raises the expectation that a similar response in patients with peripheral arterial insufficiency would significantly improve morbidity, including the symptoms of intermittent claudication.

Animals↗
PubMed1995

Training increases collateral-dependent muscle blood flow in aged rats.

The potential for physical training to enhance collateral-dependent blood flow (BF) to the hindlimbs of aged male rats (Fischer 344) was evaluated following bilateral femoral artery ligation at 20.5 mo of age. Rats were either limited to cage activity (sedentary, n = 11) or trained by a mild-intensity treadmill program (trained, n = 14), which involved walking twice a day at 15 m/min (15% grade) to fatigue, 5 days/wk for 8-11 wk. Exercise tolerance of the trained rats increased from approximately 5 to approximately 25 min/bout by week 7, whereas exercise tolerance of the sedentary group changed little (to approximately 8 min/bout) during the training period. At approximately 23 mo age, animals were surgically prepared for hindquarter perfusion (aortic pressure = 100 +/- 1.3 mmHg) and force measurement of the left gastrocnemius-plantaris-soleus (GPS) muscle group during isometric contractions at 4, 8, 15, 30, and 45 tetani/min via sciatic nerve stimulation (approximately 6 V, 0.1-ms square waves at 100 Hz for 100 ms). Although initial force development was similar between groups (12.9 N/g), trained rats maintained tension better at 8, 15, 30, and 45 tetani/min (P < 0.01). BF to the entire hindlimb of the trained group, determined with 85Sr 15-microns microspheres, was 43% greater (P < 0.05) than in the sedentary group. Thus collateral-dependent BF was improved by physical training. The greatest increase in BF was to the distal limb muscles (approximately 78%), the tissues most at risk during intermittent claudication.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1995

Heparin increases exercise-induced collateral blood flow in rats with femoral artery ligation.

The potential for heparin to enhance the training-induced increase in collateral-dependent blood flow to the distal hind-limb muscles was evaluated after bilateral femoral artery ligation in adult male rats (approximately 350 g). Rats received either saline (n = 34) or heparin (n = 36) injections and were kept sedentary (limited to cage activity) or exercised on a treadmill 5 days per week up a 15% incline by one of two protocols: (1) exercise at a constant moderate speed (20 m/min) for approximately 6 wks or (2) exercise at a progressively increased speed for 7 to 8 weeks (started at 20 m/min, increased at 15 minutes to 25 m/min, and then increased at 30 minutes to 30 m/min). Heparin- and saline-treated rats, exercised by the moderate-speed protocol, were run for the same time each day. Collateral-dependent blood flow to the distal limb tissue was determined by using 15-microns 85Sr-labeled microspheres in an isolated hindquarter preparation perfused in the descending aorta at 100 mm Hg. For comparison with the above groups, sedentary animals with acute femoral artery ligation and without femoral obstruction were included. Exercise tolerance increased from approximately 7 minutes initially to 30 to 40 minutes per bout; tolerance was greater in the heparin-injected rats than in the saline-injected rats (P < .05). Muscle performance of the gastrocnemius-plantaris-soleus muscle group (GPS) during isometric contractions in situ improved with training, was further increased by heparin administration (P < .001), and generally scaled with recovery of blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

An interactive histology image-barcode manual for a videodisc image library.

UNLABELLED: Cell Biology and HISTOLOGY (alias Microanatomy, alias Microscopic Anatomy) is a required course for first-year medical and dental students in most health science centers. The traditional approach used in teaching this discipline is to present photomicrographic images of structures to students in lecture using 35 mm slides of fields seen through the microscope. The students then spend many hours viewing and studying specimens of tissues using a light microscope in a laboratory setting. Students in traditional courses of histology spend an inordinate amount of time learning the component structures by attempting to find and identify them in tissue sections using a microscope, where the structure being sought is surrounded by a multitude of other structures with which they are also not familiar. With the recent availability of videodisc stored image libraries of histological samples, it is now possible to study histological principles without the use of the microscope as the primary learning tool. A videodisc entitled " HISTOLOGY: A Photographic Atlas" by S. Downing (published by Image Premastering Services Limited, Minneapolis, MN, 1991) has been incorporated into our histology course. Fifteen videodisc player stations are provided for 150 students. Images are retrieved by students using a bar code scanner attached to a videodisc player (Pioneer CLD-2400). Using this kind of image library, students can now learn basic histological structure, such as cell and tissue types, without the use of a microscope or as a tool for facilitating microscopy. The use of a videodisc library of randomly accessible images simplifies learning the basic components which all organs are composed of by presenting the learner with clear-cut examples to avoid confusion with other structures. However, videodisc players and TV monitors are still not appropriately priced for every student to own. This presents a problem in that the same images studied in class are not available to study and review outside of class. There is a need for resources for additional study outside of the institutional setting, for students to have and interact with to reinforce the learning experience in the teaching laboratory. A hard copy manual was created and is being used in our course; it incorporates photos captured from the videodisc. The images displayed in the manual are chosen to give the student one example of each histological component. Additional labeling is added to the images, and each image is accompanied by a bar code that may be used at a videodisc player with a bar code reader to retrieve the same color image from the disc displayed in larger format on a TV monitor. Each topic in the manual is accompanied by learning objectives and a statement of clinical relevance. Following the presentation of the images in each section of the manual, the students are encouraged to practice by viewing multiple examples of each structural component presented in the lesson. They can do this by using the bar-coded catalog supplied with each disc. The presentation of each topic concludes with a quiz composed of questions about images that the student can retrieve from the videodisc using barcodes in the text of the manual. Some of the images on the quiz are printed in miniature in the manual to provide the student with an opportunity for personal review at home when hardware to obtain and display images from a video disc is not available. This manual provides an answer to the dilemma faced by the learner when access to hardware is not available; reinforcement is therefore facilitated outside the teaching laboratory. This allows learning to continue outside of the classroom, using the same materials. (abstract truncated)

Computer-Assisted Instruction↗
PubMed1994

Increased peak oxygen consumption of trained muscle requires increased electron flux capacity.

The importance of the training-induced increase in mitochondrial capacity in realizing the increase in maximal O2 consumption (VO2max) of trained muscle was evaluated using an isolated perfused rat hindlimb preparation at a high blood flow (approximately 80 ml.min-1.100 g-1) during tetanic contractions. Rats trained for 8-12 wk by treadmill running exhibited an approximately 25% increase in muscle VO2max (5.62 +/- 0.31 to 7.06 +/- 0.64 mumol.min-1.g-1), an increase in mitochondrial enzyme activity (approximately 70% for cytochrome oxidase and approximately 55% for NADH cytochrome-c reductase), and an increase in tissue capillarity (14%) that is expected to increase the O2 exchange capacity of the tissue. Muscle VO2max of sedentary (n = 34) and trained (n = 30) animals was determined, and electron transport capacity was acutely managed with myxothiazol, a tight-binding inhibitor of complex III. Inhibition of complex III was similar among 1) the low- and high-oxidative fibers and 2) the superficial and deep mitochondrial populations within muscle. Inhibition of NADH cytochrome-c reductase activity resulted in reductions in muscle VO2max with similar dose responses (mean effective dose of approximately 0.2 microM) of myxothiazol added to the perfusion medium. The extraction of O2 by the contracting muscle decreased as VO2max declined. The increase in muscle VO2max observed in the muscle of trained animals was eliminated when its electron transport capacity was reduced to that observed in normal sedentary rat muscle. Thus, the exercise-induced adaptation of an increased muscle mitochondrial content appears to be essential for trained muscle to exhibit its increased O2 flux capacity. The results of the present experiment illustrate the importance of mitochondrial adaptations in muscle remodeled by exercise training.

Animals↗
PubMed1994

Peripheral adaptations in trained aged rats with femoral artery stenosis.

The development and functional significance of exercise-induced peripheral adaptations were evaluated in aged animals with peripheral arterial insufficiency. Fisher 344 male rats (21 months old) were subjected to bilateral stenosis of the femoral arteries sufficient to limit active hyperemia but not to impair resting blood flow. Beginning the third day after stenosis, animals were (1) exercised by walking (n = 12) on a treadmill at 20 m/min at 15% inclination, twice a day, 5 days per week, or (2) limited to cage activity (n = 10). Exercise tolerance improved from approximately 5 to approximately 35 minutes (P < .001) over the 8 weeks of the training program but increased only marginally to approximately 8 minutes for the sedentary group. An isolated hind limb preparation perfused at equivalent blood flows (approximately 1 ml.min-1 x g-1 with an arterial blood oxygen content of approximately 20 vol%) was used to assess the functional and metabolic impact of muscle-specific adaptations during sequential contraction periods at 4, 8, 15, 30, 45, 60, 75, and 90 tetani per minute. An initially similar force development of approximately 10 N/g was better maintained (P < .001) by the trained group. The peak oxygen consumption attained by the trained group of 5.68 +/- 0.34 mumol.min-1 x g-1 was greater (P < .01) than that of the sedentary group (4.34 +/- 0.29 mumol.min-1 x g-1). This was due to a greater oxygen extraction, since oxygen delivery was the same (approximately 10 mumol.min-1 x g-1) to muscles of both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1991

Functional and metabolic consequences of skeletal muscle remodeling in hypothyroidism.

Functional and metabolic responses of hypothyroid skeletal muscle were evaluated during steady-state isometric contraction conditions, using an isolated perfused rat hindlimb preparation. Treating rats with propylthiouracil (PTU) for 4-5 mo resulted in a 55% decrease (P less than 0.001) in citrate synthase activity in plantaris muscle and phenotypic remodeling of the plantaris, evident by a threefold increase in type I fiber area and a 13% decrease in type II fiber area. Perfusion of PTU (n = 9) and control (n = 9) rat hindlimbs of similar size, with similar inflow (approximately 10 ml/min) and oxygen content (approximately 20 g/100 ml), resulted in similar oxygen deliveries to the contracting muscles (PTU 11.4 +/- 0.58, control 9.54 +/- 0.75 mumol.min-1.g-1; P greater than 0.05). Ten-minute tetanic contraction (100 ms at 100 Hz) periods at 4, 8, 15, 30, and 45 tetani/min were elicited in consecutive ascending order. Oxygen consumption (VO2) was lower in the PTU group at all contraction frequencies (P less than 0.005), with a decrease in peak VO2 of 44% (PTU 3.01 +/- 0.29, control 5.35 +/- 0.42 mumol.min-1.g-1; P less than 0.001). Oxygen extraction by the PTU muscle was only approximately 25% of that delivered. Developed tension was initially less (15%; P less than 0.05) in the PTU group but declined in a similar manner, as a percent of initial, to that of the control group. The slightly lower absolute tension development of the PTU muscle could not account for the large reduction in VO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Low-intensity training produces muscle adaptations in rats with femoral artery stenosis.

The effectiveness of a mild-intensity exercise program to induce adaptations within skeletal muscle of animals with peripheral arterial insufficiency was evaluated using an isolated perfused hindlimb preparation at a muscle blood flow similar to the peak found in vivo. Adult rats were subjected to bilateral femoral artery stenosis sufficient to limit peak blood flow during exercise but not alter resting blood flow. Stenosed-trained (Sten-Trained) rats walked on a treadmill at an easily achieved speed (20 m/min with a 15% grade) 5 days wk. Exercise tolerance improved from 10 min initially to 2 h/day. Non-stenosed-sedentary (Non-Sten-Sed) and stenosed-sedentary (Sten-Sed) animals were limited to cage activity. Oxygen delivery to the contracting muscles was similar among groups (7.0 +/- 0.4, 7.3 +/- 0.6, and 6.6 +/- 0.6 mumol.min-1.g-1 in Non-Sten-Sed, Sten-Sed, and Sten-Trained, respectively; n = 13 each). Force development was better maintained by Sten-Trained muscle (P less than 0.001) during a sequence of tetanic contraction conditions. Peak oxygen consumption was greater (P less than 0.05) in the Sten-Trained (5.23 +/- 0.34 mumol.min-1.g-1) than in Non-Sten-Sed (4.08 +/- 0.35) and Sten-Sed (4.34 +/- 0.37) rats. The increased peak oxygen extraction (P less than 0.05) by the muscle of the Sten-Trained rats (82.5 +/- 7.1% of oxygen inflow vs. 58.7 +/- 4.7 and 57.4 +/- 5.0%, respectively) was probably related to the increased muscle capillarity and mitochondrial enzyme activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1990

Impact of reduced cytochrome oxidase activity on peak oxygen consumption of muscle.

The impact of reduced muscle oxidative capacity on peak oxygen consumption and isometric performance was evaluated using an isolated rat hindlimb preparation perfused with a high oxygen delivery. Capacity for electron transport was reduced with chloramphenicol (CAP), an inhibitor of mitochondrial gene-coded protein synthesis. The activity of cytochrome oxidase, a mitochondrial cristae component, was reduced approximately 45% (P less than 0.005) in the mixed-fiber-type plantaris muscle. Several facets of muscle remodeling were also evident with the 10- to 14-day CAP treatment, including decreased citrate synthase activity, increased capillarity, and increased numbers of type IIc fibers. Perfusion of CAP (n = 6) and control (n = 7) rat hindlimbs of similar size with similar total flows (10-11 ml/min) and oxygen contents (20-21 vol%) resulted in similarly high oxygen deliveries to contracting muscles of the hindlimbs (CAP, 9.66 +/- 0.83 mumols.min-1.g-1; control, 8.74 +/- 0.75). Performance of the gastrocnemius-plantaris-soleus group declined in a similar fashion for both groups during increasingly intense near-steady-state tetanic contraction (100 ms at 100 Hz) conditions of 4, 8, 15, 30, 45, and 60 per minute. Oxygen consumption was similar for both groups at rest and increased similarly at each contraction condition. Peak oxygen consumption was not different between CAP (5.34 +/- 0.55 mumols.min-1.g-1) and control (5.74 +/- 0.43) groups and required only 56-68% of the oxygen delivered. This implies that rat skeletal muscle can suffer a significant reduction in its electron transport capacity without impairing peak oxygen consumption and muscle performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

A metachromatic dye-ATPase method for the simultaneous identification of skeletal muscle fiber types I, IIA, IIB and IIC.

The histochemical demonstration of quantitative differences in myofibrillar ATPase activity at the selective pH optima of the various types of human skeletal muscle fibers is the most widely used technique for their differentiation. The basis of the reaction is the deposition of insoluble salts of inorganic phosphate cleaved from ATP by myofibrillar ATPase(s) followed by substitution of the phosphates with less soluble chromogenic salts. Doriguzzi and associates reported using metachromatic dyes to demonstrate quantitative differences in phosphate deposition among different fiber types. Following routine ATPase histochemistry and staining with either azure A or toluidine blue, fibers with low ATPase activity (and low phosphate content) were stained metachromatically while fibers with high ATPase activity (and high phosphate content) were orthochromatic with the intensity of color proportional to the content of insoluble phosphate. The metachromasia was readily lost after immoderate washing in aqueous solutions or routine dehydration in ethanol, with consequent diminished fiber type distinction. A critical modification of this technique is reported in which incubation of frozen sections of human skeletal muscle in ATP-containing medium is carried out at room temperature (22-24 C), rather than the usual 37 C, followed by a revised washing and dehydration protocol. With these modifications, the four human skeletal muscle fiber types (types I, IIA, IIB, and IIC) can be identified rapidly and reliably in single sections, obviating the need for examination of serial sections. The tinctorial differentiation allows fiber type identification even in black and white photographs.

Adenosine Triphosphatases↗
PubMed1988

Peripheral adaptations to low blood flow in muscle during exercise.

A reduction in muscle blood flow caused by central vascular or peripheral vascular disease, or both, invariably leads to a reduction in exercise tolerance. Exercise conditioning programs have been shown to be an effective means of improving exercise tolerance in many patients with cardiovascular disease. However, improvements can be found without detectable changes in total muscle blood flow during activity. This suggests that peripheral adaptations induced within active muscles by exercise training exert a beneficial influence. These adaptations could include (1) a redistribution of blood flow within the active muscle or limb, or both; (2) an enhanced capillary density within the active muscle; and (3) an increased mitochondrial content within the active muscle. Evaluation of these adaptations, in an animal model of peripheral arterial insufficiency, suggests that all 3 factors potentially serve to enhance exercise tolerance after training. The improved ability of trained muscle to accommodate the metabolic stress during contractions is noteworthy. These factors could contribute to the marked increase in endurance during mild submaximal exercise observed in patients after training.

Adaptation, Physiological↗
PubMed1988

Lesions in the rat soleus muscle following eccentrically biased exercise.

Morphological changes in skeletal muscle related to lengthening (eccentric) contractions have been noted by several laboratories. However, a systematic examination of skeletal muscle following repetitive eccentric contractions is lacking. This study was undertaken to study lesions and determine their relative densities in rat soleus muscle 30 min following level or downhill treadmill exercise. Following fixation in situ by vascular perfusion, toluidine-blue-stained 1-micron sections of the muscle samples selected at 73-micron intervals were scanned with a light microscope. Three types of lesions were noted: focal disruptions in the A-band, localized dissolution of Z-lines, and clotting of muscle fibers. Soleus muscle from the caged controls and the tibialis anterior muscle from downhill-exercised rats were essentially free of lesions. Eighty-nine percent of the soleus m. lesions in the downhill runner group and 97% of those in the level runner group were A-band disruptions. A-band lesion density was significantly higher in the soleus muscle of the downhill runners compared to level runners with the highest incidence in the distal half. A-band lesion density was lower in soleus muscles from level runners; however, the highest intramuscular incidence was in the proximal rather than the distal end. The results indicate that a disruption of the A-band is a principal change within some skeletal muscle fibers 30 min following repetitive eccentric contractions.

Animals↗
PubMed1983

Eccentric exercise-induced injury to rat skeletal muscle.

These experiments were designed to study skeletal muscle pathology resulting from eccentric-biased exercise in rats. The effects on the muscles of running on a treadmill on a 0 degrees incline (similar amounts of concentric and eccentric contractions), down a 16 degrees incline (primarily eccentric contractions), and up a 16 degrees incline (primarily concentric contractions) at 16 m . min-1 for 90 min were assessed by following postexercise changes in 1) plasma creatine kinase and lactate dehydrogenase activities, 2) glucose-6-phosphate dehydrogenase (G-6-PDase) activity (bio- and histochemically) in the physiological extensor muscles, and 3) histological appearance of the muscles. The data indicate the following. 1) Whereas all exercise protocols resulted in elevations of plasma enzymes immediately after running, only eccentric exercise caused late phase elevations 1.5-2 days postexercise. 2) Significant increases in muscle G-6-PDase activity, which were always associated with accumulations of mononuclear cells, always occurred within some muscles of each extensor group 1-3 days following downhill and uphill running and did not occur following level running; the increases in activity were usually of lower magnitude in the muscles of uphill runners than in those of downhill runners; the deeply located, predominantly slow-twitch muscles were most affected by both down- and uphill running. 3) Muscle histology demonstrated localized disruption of normal banding patterns of some fibers immediately after exercise and accumulations of macrophages in the interstitium and in some (less than 5%) muscle fibers by 24 h postexercise in the deep slow muscles of the antigravity groups. Although the data generally indicated that eccentric exercise causes greater injury to the muscles, questions remain.

Animals↗
PubMed1980

Backscatter electron imaging (BEI) of paraffin sections stained with heavy metal histopathologic stains, with observations on some variables encountered in BEI.

Using a recently developed annular photolithographic type backscatter detector, we studied a number of heavy metal stains used routinely in light microscopy. These were paraffin sections fixed with standard light microscopic fixation and dehydration techniques with no special modification made to them prior to coating of the slides with carbon for scanning observations. It was found that many of the stains that work in light microscopy will also provide good results in backscatter imaging if the differentiation of the staining is good. Studying the effects of varying accelerating voltages, it was discovered that optimum results and the most reliable data are achieved by comparative examination of the specimen at both a low and high voltage. This is necessary to prevent misinterpretation of data as a result of inadequate beam penetration of the sample.

Animals↗