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Biomedical subjects

C A Harms

Publications and source records attributed to C A Harms.

At least 19 recordsLinked to original sources
PubMed2007

The identification of a genetically unique piroplasma in North American river otters (Lontra canadensis).

During a routine health check of a wild-caught North American river otter (Lontra canadensis) small piroplasms were noted within erythrocytes. Analyses of the 18S ribosomal ribonucleic acid (rRNA) gene sequences determined that this was a genetically unique organism most closely related to Babesia microti-like parasites found in other small carnivores. Subsequently 39 wild-trapped North American river otters from North Carolina were tested for the presence of piroplasma deoxyribonucleic acid (DNA) via polymerase chain reaction and piroplasma DNA was detected in 82% (32/39) of these samples. Sequencing of partial 18S rRNA genes from selected cases determined that they were identical to the sentinel case. This report documents the existence of a genetically unique piroplasma in North American river otters and indicates that the prevalence of piroplasma in North Carolina otters is quite high. The pathogenic potential of this organism for otters or other species remains unknown.

Animals↗
PubMed2005

A quantitative real-time RT-PCR assay to measure TGF-beta mRNA and its correlation with hematologic, plasma chemistry and organo-somatic indices responses in triamcinolone-treated Atlantic menhaden, Brevoortia tyrannus.

A quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) assay was developed to measure transforming growth factor-beta (TGF-beta) in Atlantic menhaden (Brevoortia tyrannus), an estuarine-dependent species plagued by ulcerative skin lesions in the estuaries along the eastern United States. Atlantic menhaden were acclimated in a closed system for two weeks prior to initiation of the study. The synthetic glucocorticoid, triamcinolone acetonide (10mg/kg body weight) was administered by intracoelomic injection and its effect on the splenic mononuclear cell TGF-beta mRNA transcription, liver-somatic index, spleno-somatic index, hematology, and plasma chemistry were compared to untreated fish at 48 and 96h post-treatment. Triamcinolone-treated Atlantic menhaden showed suppression of TGF-beta mRNA production, neutrophilia, monocytosis, lymphopenia, and an increase in blood glucose concentrations. The health indices used in this study may help us interpret some of the changes observed during the development of ulcerative skin lesions in wild-caught menhaden.

Animals↗
PubMed2005

Enrofloxacin pharmacokinetics in the European cuttlefish, Sepia officinalis, after a single i.v. injection and bath administration.

Enrofloxacin pharmacokinetics were studied in European cuttlefish, Sepia officinalis, after a single 5 mg/kg i.v. injection or a 2.5 mg/L 5 h bath. A pilot study with two animals was also performed following a 10 mg/kg p.o. administration. The concentration of enrofloxacin in hemolymph was assayed using high-performance liquid chromatography (HPLC) and pharmacokinetic parameters were derived from compartmental methods. In the i.v. study, the terminal half-life (t(1/2)), apparent volume of distribution, and systemic clearance were respectively 1.81 h, 385 mL/kg, and 4.71 mL/min/kg. Following bath administration the t(1/2), peak hemolymph concentration (C(max)), and area under the curve to infinity (AUC(0-infinity)) were 1.01 h, 0.5 +/- 0.12 mug/mL, and 0.98 microg.h/mL, respectively. After oral administration, the t(1/2), C(max), and AUC(0-infinity) were 1.01 h, 10.95 microg/mL, 26.71 mug.h/mL, respectively. The active metabolite of enrofloxacin, ciprofloxacin, was not detected in any samples tested. The hemolymph concentration was still above minimum inhibitory concentration (MIC) values for shrimp and fish bacterial isolates at 6 h after i.v. administration, therefore, a dose of 5 mg/kg i.v. every 8-12 h is suggested for additional studies of efficacy. The C(max) value for the water bath was lower than for the i.v. study, but a bath of 2.5 mg/L for 5 h once to twice daily is suggested for additional studies to test efficacy against highly susceptible organisms. Although only two animals were used for the oral study, a dose of 10 mg/kg produced hemolymph concentrations of enrofloxacin that were in a range consistent with therapeutic efficacy in other species.

Administration, Cutaneous↗
PubMed2001

Clothing fabric does not affect thermoregulation during exercise in moderate heat.

PURPOSE: We investigated whether temperature regulation is improved during exercise in moderate heat by the use of clothing constructed from fabric that was purported to promote sweat evaporation compared with traditional fabrics. METHODS: Eight well-trained, euhydrated males performed three exercise bouts wearing garments made from an evaporative polyester fabric (SYN), wearing garments made from traditional cotton fabric (COT), or dressed seminude (S-N) in random order. Bouts consisted of 15 min seated rest, 30 min running at 70% .VO(2max), 15 min walking at 40% .VO(2max), and 15 min seated rest, all at 30 +/- 1 degrees C and 35 +/- 5% relative humidity. COT and SYN clothing ensembles consisted of crew neck, short sleeve T-shirts, cycling shorts, and anklet socks made from their respective materials, and running shoes. The S-N condition consisted of a Lycra swim suit, polyester socks, and running shoes. RESULTS: Mean skin temperature was lower for S-N during preexercise rest when compared with SYN and COT. No differences in mean body temperature, rectal temperature, or mean skin temperature were observed during or after exercise. No differences in VO2 or heart rate were observed. No differences in comfort sensations were observed. CONCLUSION: In summary, before, during, or after exercise in a moderately warm environmental condition, neither the addition of a modest amount of clothing nor the fabric characteristics of this clothing alters physiological, thermoregulatory, or comfort sensation responses.

Adult↗
PubMed2001

Treatment of Argulus sp. infestation of river frogs.

Ten river frog tadpoles (Rana hecksheri) were collected from Pointsett State Park in South Carolina in April 1995. They were housed together in a tank at the North Carolina Zoological Park. Although no skin lesions were evident at collection, skin scrapings performed 4 weeks later revealed numerous immature and adult Argulus sp. on the tails and dorsal trunks of many of the tadpoles. The adult parasites were removed manually, and the tadpoles were treated with lufenuron (15 mg/l; Program, Novartis Animal Health, Greensboro, N.C.) and sodium chloride (3 g/l) in the tank water for 3 weeks. A single immature Argulus was found on a skin scraping on day 2 of treatment, and no parasites were seen thereafter on skin scrapings obtained through day 28 after the initiation of treatment. Metamorphosis occurred in all tadpoles within 4 weeks of initiating treatment. No deleterious effects of the treatment were noted.

Animals↗
PubMed2000

Cloning and sequencing hybrid striped bass (Morone saxatilis x M. chrysops) transforming growth factor-beta (TGF-beta), and development of a reverse transcription quantitative competitive polymerase chain reaction (RT-qcPCR) assay to measure TGF-beta mRNA of teleost fish.

A transforming growth factor (TGF)-beta was isolated and cloned from hybrid striped bass (Morone saxatilis x M. chrysops) anterior kidney mononuclear cells. This isolate (Genbank accession number AF140363) contains an open reading frame of 1146 bases coding for a 382 amino acid protein most similar to rainbow trout TGF-beta (57.3 and 78.6% identity with precursor and active protein, respectively) and rat TGF-beta 1 (41.1 and 68.8% identity with precursor and active protein, respectively). Consensus primers were demonstrated to amplify specifically by polymerase chain reaction (PCR), a TGF-beta segment from 14 species of teleost fish comprising 10 taxonomic families in 7 orders. A reverse transcription quantitative competitive polymerase chain reaction (RT-qcPCR) assay was devised to measure TGF-beta mRNA expression in teleost fish. Higher levels of TGF-beta mRNA expression were detected in mononuclear cells of peripheral blood than from spleen or anterior kidney.

Amino Acid Sequence↗
PubMed2000

Surgery in fish.

Surgery in fish is feasible and practical for clinical and research applications. Certain adjustments in standard surgical procedures are necessary to accommodate piscine tissue handling, skin sensitivity, aqueous respiration, anatomic variations, and patient size. General considerations for fish surgery, including anesthesia, presurgical evaluation, equipment, suture selection, and surgical site preparation, have been presented here. Procedures described include celiotomy, enucleation, pseudobranchectomy, swim bladder surgery, gonadectomy, liver and kidney biopsy techniques, telemetry device implantation, and vascular catheterization.

Animals↗
PubMed2000

Skeletal muscle: master or slave of the cardiovascular system?

Skeletal muscle and cardiovascular system responses to exercise are so closely entwined that it is often difficult to determine the effector from the affector. The purpose of this manuscript and its companion papers is to highlight (and perhaps assist in unraveling) the interdependency between skeletal muscle and the cardiovascular system in both chronic and acute exercise. Specifically, we elucidate four main areas: 1) how a finite cardiac output is allocated to a large and demanding mass of skeletal muscle, 2) whether maximal muscle oxygen uptake is determined peripherally or centrally, 3) whether blood flow or muscle metabolism set the kinetic response to the start of exercise, and 4) the matching of structural adaptations in muscle and the microcirculation in response to exercise. This manuscript, the product of an American College of Sports Medicine Symposium, unites the thoughts and findings of four researchers, each with different interests and perspectives, but with the common intent to better understand the interaction between oxygen supply and metabolic demand during exercise.

Adaptation, Physiological↗
PubMed2000

Effect of skeletal muscle demand on cardiovascular function.

Cardiac output is directed primarily to skeletal muscle during exercise. Recent investigations have examined how different groups of skeletal muscle compete for the cardiac output during exercise. To date, there is a lack of consistent findings on a blood flow steal effect of arm versus leg exercise, although the majority of data suggest that leg blood flow is not compromised when arm exercise is added to leg exercise. A recent set of experiments have demonstrated that respiratory muscles compete favorably for blood flow with the legs during maximal exercise. Decreased work of breathing leads to: 1) a decrease in cardiac output, due primarily to reduced stroke volume; and 2) increased leg blood flow and leg vascular conductance. An increased work of breathing leads to the converse. Exercise performance may also be affected by the work of breathing during heavy exercise due to redistribution of blood flow between the chest wall and the locomotor muscles. It appears that in contrast to arm exercise, respiratory muscles demand a significant portion of the cardiac output during maximal exercise, and the work of breathing normally experienced during heavy exercise compromises leg blood flow.

Arm↗
PubMed2000

Effect of exercise-induced arterial O2 desaturation on VO2max in women.

PURPOSE: We have recently reported that many healthy habitually active women experience exercise induced arterial hypoxemia (EIAH). We questioned whether EIAH affected VO2max in this population and whether the effect was similar to that reported in men. METHODS: Twenty-five healthy young women with widely varying fitness levels (VO2max, 56.7 +/- 1.5 mL x kg(-1) x min(-1); range: 41-70 mL x kg(-1) x min(-1)) and normal resting lung function performed two randomized incremental treadmill tests to VO2max (FIO2: 0.21 or 0.26) during the follicular phase of their menstrual cycle. Arterial blood samples were taken at rest and near the end of each workload during the normoxic test. RESULTS: During room air breathing at VO2max, SaO2 decreased to 91.8 +/- 0.4% (range 87-95%). With 0.26 FIO2, SaO2, at VO2max remained near resting levels and averaged 96.8 +/- 0.1% (range 96-98%). When arterial O2 desaturation was prevented via increased FIO2, VO2max increased in 22 of the 25 subjects and in proportion to the degree of arterial O2 desaturation experienced in normoxia (r = 0.88). The improvement in VO2max when systemic normoxia was maintained averaged 6.3 +/- 0.3% (range 0 to +15%) and the slope of the relationship was approximately 2% increase in VO2max for every 1% decrement in the arterial oxygen saturation below resting values. About 75% of the increase in VO2max resulted from an increase in VO2 at a fixed maximal work rate and exercise duration, and the remainder resulted from an increase in maximal work rate. CONCLUSIONS: These data demonstrate that even small amounts of EIAH (i.e., >3% delta SaO2 below rest) have a significant detrimental effect on VO2max in habitually active women with a wide range of VO2max. In combination with our previous findings documenting EIAH in females, we propose that inadequate pulmonary structure/function in many habitually active women serves as a primary limiting factor in maximal O2 transport and utilization during maximal exercise.

Adolescent↗
PubMed2000

Effects of respiratory muscle work on exercise performance.

The normal respiratory muscle effort at maximal exercise requires a significant fraction of cardiac output and causes leg blood flow to fall. We questioned whether the high levels of respiratory muscle work experienced in heavy exercise would affect performance. Seven male cyclists [maximal O(2) consumption (VO(2)) 63 +/- 5 ml. kg(-1). min(-1)] each completed 11 randomized trials on a cycle ergometer at a workload requiring 90% maximal VO(2). Respiratory muscle work was either decreased (unloading), increased (loading), or unchanged (control). Time to exhaustion was increased with unloading in 76% of the trials by an average of 1.3 +/- 0.4 min or 14 +/- 5% and decreased with loading in 83% of the trials by an average of 1.0 +/- 0.6 min or 15 +/- 3% compared with control (P < 0.05). Respiratory muscle unloading during exercise reduced VO(2), caused hyperventilation, and reduced the rate of change in perceptions of respiratory and limb discomfort throughout the duration of exercise. These findings demonstrate that the work of breathing normally incurred during sustained, heavy-intensity exercise (90% VO(2)) has a significant influence on exercise performance. We speculate that this effect of the normal respiratory muscle load on performance in trained male cyclists is due to the associated reduction in leg blood flow, which enhances both the onset of leg fatigue and the intensity with which both leg and respiratory muscle efforts are perceived.

Adult↗
PubMed2000

Quantitative polymerase chain reaction for transforming growth factor-beta applied to a field study of fish health in Chesapeake Bay tributaries.

Fish morbidity and mortality events in Chesapeake Bay tributaries have aroused concern over the health of this important aquatic ecosystem. We applied a recently described method for quantifying mRNA of an immunosuppressive cytokine, transforming growth factor-beta (TGF-beta), by reverse transcription quantitative-competitive polymerase chain reaction to a field study of fish health in the Chesapeake Basin, and compared the results to those of a traditional cellular immunoassay macrophage bactericidal activity. We selected the white perch (Morone americana) as the sentinel fish species because of its abundance at all of the collection sites. White perch were sampled from Chesapeake Bay tributaries in June, August, and October 1998. Splenic mononuclear cell TGF-beta mRNA levels increased and anterior kidney macrophage bactericidal activity decreased, particularly in eastern shore tributaries, from June to August and October. The results of the two assays correlated inversely (Kendall's [Tau] b = -0.600; p = 0.0102). The results indicated both temporal and spatial modulation of white perch immune systems in the Chesapeake Basin, and demonstrated the utility of quantitative PCR for TGF-beta as a molecular biomarker for field assessment of teleost fish immune status.

Animals↗
PubMed2000

Use of a two-step Percoll gradient for separation of loggerhead sea turtle peripheral blood mononuclear cells.

In order to determine a suitable procedure for isolating peripheral blood mononuclear cells (PBMCs) from loggerhead sea turtles (Caretta caretta), blood was collected using three different anticoagulants (sodium heparin, sodium citrate or potassium EDTA) and separated using a single step commercially-prepared arabinogalactan gradient of 1.077 g/ml density or multiple step Percoll gradients between 1.053 and 1.076 g/ml density (40-60% stock isotonic Percoll suspension). Heparinized blood centrifuged over a two-step 45/55% (1.059/1.070 g/ml) Percoll gradient yielded 99 to 100% mononuclear cells at the 45/55% interface. Mononuclear cell viability ranged from 85 to 97% with cell yields up to 9.2 x 10(6) cells/mL. An unexpected finding was a population of low density granulocytes migrating to 40% (1.053 g/ml) and 45% Percoll layers in the multiple step gradients. These granulocytes could be eliminated from the PBMC preparation by use of the two-step 45/55% Percoll gradient. Isolated PBMCs can be used for cellular immunology and toxicology studies on these threatened marine organisms for which other tissues can usually be obtained only sporadically from post-mortem specimens.

Animals↗
PubMed2000

Evaluation of epidural morphine for postoperative analgesia in ferrets (Mustela putorius furo).

We evaluated the analgesic efficacy of epidural morphine for relieving postoperative pain in domestic ferrets by evaluating behavior and fecal cortisol concentrations. The 12 laboratory-reared, intact, female, domestic ferrets were anesthetized then underwent ovariohysterectomy and bilateral anal sacculectomy. Using a double-blind procedure, we provided epidural morphine (0.1 mg/kg) to six ferrets and epidural saline (0.1 mL/ferret) to the remaining animals prior to surgery. Compared to the animals that received saline, the morphine-treated ferrets were more likely to have attenuated pain responses, and they returned more rapidly to preoperative behavior. Although fecal cortisol concentrations during the first 24 h after surgery increased in all animals, the increase was statistically significant only in the ferrets that received saline epidurals. These data suggest that morphine epidurals administered to ferrets prior to surgery may attenuate both the physiologic and behavioral manifestations of surgically induced pain.

Analgesics, Opioid↗
PubMed1999

Influence of respiratory muscle work on VO(2) and leg blood flow during submaximal exercise.

The work of breathing (W(b)) normally incurred during maximal exercise not only requires substantial cardiac output and O(2) consumption (VO(2)) but also causes vasoconstriction in locomotor muscles and compromises leg blood flow (Q(leg)). We wondered whether the W(b) normally incurred during submaximal exercise would also reduce Q(leg). Therefore, we investigated the effects of changing the W(b) on Q(leg) via thermodilution in 10 healthy trained male cyclists [maximal VO(2) (VO(2 max)) = 59 +/- 9 ml. kg(-1). min(-1)] during repeated bouts of cycle exercise at work rates corresponding to 50 and 75% of VO(2 max). Inspiratory muscle work was 1) reduced 40 +/- 6% via a proportional-assist ventilator, 2) not manipulated (control), or 3) increased 61 +/- 8% by addition of inspiratory resistive loads. Increasing the W(b) during submaximal exercise caused VO(2) to increase; decreasing the W(b) was associated with lower VO(2) (DeltaVO(2) = 0.12 and 0.21 l/min at 50 and 75% of VO(2 max), respectively, for approximately 100% change in W(b)). There were no significant changes in leg vascular resistance (LVR), norepinephrine spillover, arterial pressure, or Q(leg) when W(b) was reduced or increased. Why are LVR, norepinephrine spillover, and Q(leg) influenced by the W(b) at maximal but not submaximal exercise? We postulate that at submaximal work rates and ventilation rates the normal W(b) required makes insufficient demands for VO(2) and cardiac output to require any cardiovascular adjustment and is too small to activate sympathetic vasoconstrictor efferent output. Furthermore, even a 50-70% increase in W(b) during submaximal exercise, as might be encountered in conditions where ventilation rates and/or inspiratory flow resistive forces are higher than normal, also does not elicit changes in LVR or Q(leg).

Adult↗
PubMed1999

Technique of mandibular salivary gland biopsy in river otters (Lutra canadensis).

A Franklin-Silverman biopsy needle was used to obtain 2-5- x 1-2-mm mandibular salivary gland tissue samples percutaneously from nine North American river otters (Lutra canadensis). The samples were suitable for fluorescent antibody or polymerase chain reaction rabies testing. Ninety-two percent (11/12) of the biopsy procedures yielded histologically confirmed salivary gland tissue, and the remaining biopsy yielded adipose tissue. No complications were noted after 5-21 days.

Animals↗
PubMed1999

Cardiovascular consequences of exercise hyperpnea.

In summary, evidence shows that the respiratory muscles demand a significant portion of the cardiac output during maximal exercise. Estimates of both animal and human blood flow and VO2 to the respiratory muscles during maximal exercise approximate 14-16% of the total cardiac output and VO2. During heavy exercise, this metabolic demand of the respiratory muscles affects the distribution of cardiac output between the respiratory muscles and the legs such that leg vascular conductance and blood flow increases with respiratory muscle unloading and decreases with respiratory loading. The reflex effects underlying this blood flow redistribution remain unknown; however, these data do clearly support the existence of a significant sympathetic effect output to working skeletal muscle in heavy exercise. These data also invite the exciting (although speculative) prospect of important chemo- or mechano-induced reflexes emanating from respiratory muscle under load.Finally, while not yet completely understood or investigated, it appears that respiratory muscle work during strenuous exercise affects exercise performance.

Animals↗