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Body size, sex ratio and timing of reproduction of the sand shrimp, Crangon septemspinosa Say (1818), and the distribution of larvae and adults with respect to temperature and salinity, were studied in the estuary of the Kouchibouguac River, New Brunswick. Contrary to predictions, body size was not related to latitude or biogeographic zone. Reproduction in May and June by a cohort of large females, followed in summer and early fall by a cohort of smaller reproductive females, was consistent with previous reports of estuarine populations. Reproduction was continuous throughout the spring and summer, in contrast to the two distinct spawning seasons reported for other northerly populations. Larvae were most abundant in July. At least part of the adult population remained in shallow waters of the estuary throughout the summer, at temperatures up to 28°C, unlike the offshore migrations reported for most other populations during periods of warm water conditions.

Parasites are integral components of marine ecosystems, a general observation accepted by parasitologists, but often considered of trifling significance to the broader community of zoologists. Parasites, however, represent elegant tools to explore the origins, distribution and maintenance of biodiversity. Among these diverse assemblages, host and geographic ranges described by various helminths are structured and historically constrained by genealogical and ecological associations that can be revealed and evaluated using phylogenetic methodologies within the context of frameworks and hypotheses for co-evolution and historical biogeography. Despite over 200 years of sporadic investigations of helminth systematics, knowledge of parasite faunal diversity in chondrichthyan and osteichthyan fishes, seabirds and marine mammals remains to be distilled into a coherent and comprehensive picture that can be assessed using phylogenetic approaches. Phylogenetic studies among complex host–parasite assemblages that encompass varying temporal and geographic scales are the critical context for elucidating biodiversity and faunal structure, and for identifying historical and contemporary determinants of ecological organization and biogeographic patterns across the marine biosphere. Insights from phylogenetic inference indicate (1) the great age of marine parasite faunas; (2) a significant role for colonization in diversification across a taxonomic continuum at deep and relatively recent temporal scales; and (3) a primary role for allopatric speciation. Integration of ecological and phylogenetic knowledge from the study of parasites is synergistic, contributing substantial insights into the history and maintenance of marine systems.

Three female specimens of C. rigidum were found in zooplankton samples from the Kouchibouguac and East River Estuaries in the southern Gulf of St. Lawrence, representing a new record for the northwest Atlantic. The geographic distribution of other monstrilloids in the northwest Atlantic and Arctic are also summarized. Variations in morphological characters were found between C. rigidum females found in the latter estuaries and those of C. rigidum Thompson, 1888 and are discussed herein. Trois specimens femelles du monstrilloide C. rigidum ont ete trouves dans des echantillons de zooplancton collectes dans les estuaires des rivieres Kouchibouguac et East, situees dans le sud du Golfe St. Laurent. La presence de ces femelles dans ces estuaires represente un nouveau signalement pour le nord-ouest de l'Atlantique. Un sommaire de la repartition geographique des monstrilloides dans le nord-ouest de l'Atlantique et l'Arctique est presente. Les differences morphologiques entre les specimens femelles de C. rigidum retrouves dans ces estuaires et le specimen-type femelle de C. rigidum Thompson, 1888 y sont discutees.

HIV-1 infection results in a dementing illness affecting 20% of patients with AIDS. Several HIV-1 genes have been implicated in the pathogenesis of HIV-induced neurological disease. To search for distinct HIV-1 sequences associated with the development of dementia, brain-derived tat, env, and pol sequences were examined from AIDS patients defined pre-mortem as demented (HIV-D)[n=5] or non-demented (HIV-ND)[n=5]. Estimations of evolutionary distances and frequency of non-synonymous mutation rates revealed significant differences between brain-derived tat, env, and pol-encoded reverse transcriptase sequences. However, established zidovudine-associated resistance mutations in reverse transcriptase sequences were identified in only one HIV-D and one HIV-ND patient despite prolonged treatment of some patients. Non-synonymous/synonymous substitution rates among the tat sequences derived from patients with HIV-D were significantly higher compared to the HIV-ND group (P0.001). The ratios of transversions to transitions were also significantly higher among the HIV-D tat sequences (P0.01). Phylogenetic analyses showed clustering of sequences from each clinical group among the brain-derived tat and env sequences. These studies indicated that differing selective forces act on individual HIV-1 genes in the brain which may influence the development of dementia.

Seventy-four catalase protein sequences, including 29 bacterial, 8 fungal, 7 animal, and 30 plant sequences, were compiled, and 70 were used for phylogenetic reconstruction. The core of the resulting tree revealed unique, separate groups of plant and animal catalases, two groups of fungal catalases, and three groups of bacterial catalases. The only overlap of kingdoms occurred within one branch and involved fungal and bacterial large-subunit enzymes. The other fungal branch was closely linked to the group of animal enzymes. Group I bacterial catalases were more closely related to the plant enzymes and contained such diverse taxa as the Gram-positive Listeria seeligeri, Deinocococcus radiodurans, and gamma-proteobacteria. Group III bacterial sequences were more closely related to fungal and animal sequences and included enzymes from a broad range of bacteria including high- and low-GC Gram positives, proteobacteria, and a bacteroides species. Group II was composed of large-subunit catalases from diverse sources including Gram positives (low-GC Bacilli and high-GC Mycobacteria), proteobacteria, and species of the filamentous fungus Aspergillus. These data can be interpreted in terms of two gene duplication events that produced a minimum of three catalase gene family members that subsequently evolved in response to environmental demands. Horizontal gene transfer may have been responsible for the group II mixture of bacterial and fungal large-subunit catalases.

This study was undertaken to determine the range of consistency index (CI) values obtainable from random data sets. We generated multiple random data matrices for each of 49 different matrix sizes ranging from 5 taxa and 4 (binary) characters to 49 taxa and 124 characters. The CI of the minimum-length tree(s) was calculated for each. CIs decreased in a monotonic, nonlinear fashion with addition of either taxa or characters. The influence of addition of taxa was far greater than that of addition of characters, and an interaction effect was recognized. The general curvilinear relation we found between CIs and number of taxa is consistent with results obtained by other authors, but our random data CIs were lower than those of other studies

Knowledge of the patterns of movement of red cells during the cardiac cycle in the microcirculation within the contracting myocardium is largely unknown. We describe a method of making such measurements in the canine myocardium using the technique of laser Doppler velocimetry.A lensed 100 microm fiber-optic probe was inserted into the beating myocardium at various sites. Using an ultra-stable laser and achieving measurement stability by heterodyning the laser light and reflected light from the tissue, it was possible to obtain a stable high quality measurement of predominately red cell movement in the microcirculation.Unique regional patterns of red cell movement within the myocardium were observed. Epicardial flux was continuous with peaks while endocardial flux was predominately diastolic. Stopping flow in the epicardial artery for 5-6 s demonstrated that red cell movement continues in the microcirculation with some reduction followed by a delayed reactive hyperemia. Modeling demonstrates an important role for the small coronary veins in control of microcirculatory red cell movement.It is possible using laser Doppler velocimetry to measure red blood cell flux in the beating canine myocardium. Such measurements demonstrate a high degree of complexity which is not reflected in epicardial coronary arterial or venous flow.

To determine whether red cell movement, as measured by laser Doppler velocimetry, in the capillary net of the beating heart is chaotic.Using two dog hearts, in situ red blood cell flux was measured at many sites. Simultaneously, epicardial arterial flow and left ventricular pressure were recorded via transit-time flowmeter and catheter manometer, respectively. The presence or absence of chaos was tested by two methods: Lyapunov exponents and correlation dimension.For capillary red cell flux, the Lyapunov was strongly positive at most sites. It was less so for coronary arterial flow and least for left ventricular pressure. Correlation dimension calculation was less able to distinguish the presence or absence of chaos in capillary red cell tissue flux, coronary arterial flow, and left ventricular pressure.Capillary red cell flux (movement of red cells in capillaries) is nonlinear, (i.e., chaotic). This complexity suggests that the primary control for oxygen delivery to cardiac myocytes by red blood cells resides in the microcirculation. Also, capillary red cell flux is bifractal, suggesting an ordering of control.

This review examines past and present observations concerning the structure and function of the coronary circulation in health and disease. These observations are considered in the context of how we might proceed to increase understanding of this circulation in the future. The coronary microcirculation with its intimate relationship of capillaries and myocytes and the coronary venous circulation are identified as parts of the coronary circulation in need of further study. Observations using a laser Doppler velocimeter placed within the beating myocardium are presented. Such devices measure the velocity of red cells continuously (red cell flux) and can demonstrate that tissue hematocrit and hence oxygen delivery can be regulated independently of total epicardial arterial volume flow. Implications for the understanding of the pathophysiology of coronary artery disease are presented. As considerations are given to molecular genetic techniques to revascularize the ischemic myocardium we will require a more complete knowledge of coronary circulatory dynamics, myocardial support tissues' responses, and cardiac myocyte interactions to design appropriate interventions. The clinical trial is an appropriate clinical tool to measure effectiveness but a blunt instrument to determine pathophysiology. The purpose of the review is to suggest that advances in measurement of end points are required to permit the right question to be posed.

To determine the steady-state plasma concentrations of diltiazem (DTZ) and hemodynamic effect in humans at rest and during exercise.Healthy volunteers (10 F, mean age 22, and 11 M, mean age 24) were recruited. Prior to receiving DTZ, each volunteer performed two 3-minute stages of treadmill exercise according to the Bruce protocol. Intra-arterial BP and ECG recordings were obtained before, during and immediately post exercise. Each volunteer then received DTZ 60 mg qid for one week. The same exercise protocol was repeated 1 h after the last dose. Steady-state plasma concentrations of DTZ were determined by a previously reported HPLC.DTZ decreased resting DBP from 84 +/- 13 to 79 +/- 10 mmHg (p0.05), and HR from 89 +/- 11 to 82 +/- 13 bpm (p0.05). During exercise, an average of 32 and 10% increase in SBP and DBP, respectively, and a 47% increase of HR was found (p0.05). DTZ limited these increases to 21% for SBP, 5% for DBP, and 44% for HR (p0.05 for drug effect). Steady-state plasma DTZ concentrations were 141 +/- 56 ng/ml.DTZ significantly decreased resting HR but not BP in health volunteers. It decreased both hemodynamic variables during exercise. Thus, the hemodynamic effects of diltiazem are more profound during exercise, and may be more useful surrogate markers for calcium antagonists and other cardiovascular agents in healthy volunteer studies.

The non-transcribed spacer of the ribosomal DNA repeat of Pythium pachycaule was found to exist in two versions, one about 200 bp longer than the other. Both versions contained a conserved 5s rRNA gene in inverted orientation and a diverged copy of the 5s sequence as a tandem repeat, with a spacer of about 180 bp between them. This is the first report of multiple 5s-like sequences in the non-transcribed spacer of the rDNA of any organism. The two diverged 5s sequences differ from each other at nine positions in the 5' half of the sequence, but they have the same central 10-bp deletion and their 3' halves are identical. The diverged sequences, 5s' and 5s'', when aligned with the 5s sequence, have the same base at 63.9 and 58.8% of the positions respectively. The spacers between 5s sequences in both versions were highly conserved. The secondary structures of potential rRNA products of the diverged 5s sequences indicate that they may be pseudogenes. The relationships between the functional 5s gene and the diverged gene copies suggest that the 5s sequence family of P. pachycaule originated by duplication of an ancestral gene, followed by divergence and the introduction of heterogeneity. This work shows the potential for tandemization of 5s genes in the NTS, and may shed light on the evolutionary events that led to the transition from the rDNA-linked 5s genes found in Pythium species with filamentous zoosporangia to the unlinked tandem arrays found in Pythium species with globose zoosporangia.

To examine histologically biopsies from the coronary arteries of patients undergoing coronary artery bypass grafting (CABG) for evidence of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) antigen and to correlate the incidence with pathological and clinical data.Sequential patients undergoing CABG in whom adequate tissue could be obtained for histology.University teaching hospital.Forty-six patients were enrolled. Thirty-one provided sufficient tissue and clinical information for the analysis.Biopsy material was collected in the operating room and prepared immediately for histology and electron microscopy. Slides were prepared by staining with hematoxylin and eosin, Masson trichrome, avidin biotin complex immunoperoxidase for HSV-1 and HSV-2 protein and specific DNA probes for HSV-1 and HSV-2 by hybridization. Clinical data were obtained in structured interviews.Sixty-one per cent of biopsies demonstrated evidence of inflammation, 45% were positive for antigen to HSV-2 and only one to HSV-1. Significant positive correlations were detected between inflammatory cells in the biopsy and a recent history of cold sores and between the presence of the infiltrate and positivity to HSV-2 antigen.A correlation exists between HSV-2 infection and the inflammatory response associated with atherosclerosis.

The hypothesis that Haliotrema species from boxfishes, which are members of the bodiani group, form a monophyletic lineage was tested. The analysis was conducted for the 19 species of the bodiani group, which includes 8 species from boxfishes, in a matrix of 13 terminal taxa and 14 characters (total of 15 states). A single, most parsimonious cladogram (c.i. = 75%, r.i. = 85%) was generated. The 8 Haliotrema species from boxfishes (H. trochaderoi, H. crymanum, H. lactophrys, H. guadeloupensis, H. glandulosum, H. torridum, H. minutum, and H. kritskyi) were found to form a monophyletic lineage within the bodiani group; 3 of the 14 characters from the analysis were hypothesized to contain homoplastic states.

The hypothesis that Haliotrema species from boxfishes form a monophyletic lineage was tested. The analysis was conducted for an ingroup of 62 species (including 10 from boxfishes), in a matrix of 20 terminal taxa and 17 characters (total of 21 states). Eight equally parsimonious cladograms (c.i. = 84%, r.i. = 91%) were generated. Two Haliotrema species from boxfishes (H. lactoriae and H. triacanthi) were found to be more closely related to other Haliotrema species than to the remaining 8 from boxfishes. The remaining 8 (H. trochaderoi, H. crymanum, H. lactophrys, H. guadeloupensis, H. glandulosum, H. torridum, H. minutum, and H. kritskyi) constituted part of the bodiani group (total of 19 species). Five of the 17 characters from the analysis were hypothesized to contain homoplastic states. Missing character coding, rounding error, and "ghost characters" influenced resolution.

To describe the functional anatomy of the epicardial veins, including their dimensional changes in systole and diastole, and to relate these observations to the pattern of bloodflow in these veins.Using quantitative angiography and casts of epicardial veins in dogs, measurements of dimensions and anatomical patterns were observed.Venous angiograms were performed on 21 mongrel dogs. The diameters of epicardial veins in systole and diastole were measured using ECG gating. The dynamic anatomy of epicardial veins observed from video tapes was compared with static images and casts.The transverse diameter of the epicardial veins was similar in systole and diastole. The accuracy of measurement was limited by definition of the edges of the veins. An area of reduced contrast was observed in the posterior lateral section of the great cardiac vein and the appearance of gaps in the column of contrast material within the epicardial veins was consistently seen.These observations suggest that flow in epicardial coronary veins occurs as a bolus during each cardiac cycle.

The 5S ribosomal RNA (rRNA) genes in eukaryotes may occur either interspersed with the other rRNA genes in the ribosomal DNA (rDNA) repeat, or in separate tandem arrays, or dispersed throughout the genome. In Pythium species and in several related Oomycetes, polymerase chain reaction (PCR) amplification of the nontranscribed spacer (NTS) region with one primer specific for the 5S gene revealed, with several exceptions, that the 5S rRNA gene was present in the rDNA repeat of those species with filamentous sporangia and was absent from the rDNA repeat of those with globose or unknown sporangia. When present, the gene was located approximately 1 kb downstream of the large-subunit rRNA gene and on the strand opposite that on which the other rRNA genes were located. This was confirmed in P. torulosum by sequencing of the gene and its flanking regions. The 5S rRNA genes of P. ultimum were found in tandem arrays outside the rDNA repeat. Evidence of dispersed 5S rRNA sequences was also observed. For many of the species of Pythium having the 5S gene in the NTS, the region between the large-subunit rRNA gene and the 5S gene was found to have length heterogeneity. Oomycetes related to Pythium were also found to have the 5S gene in the NTS, although sometimes in the opposite orientation. This may mean that the presence of the gene in the NTS is ancestral for the Oomycetes and that the absence of the gene in the NTS in those Pythiums with globose sporangia is due to loss of the gene from the rDNA repeat in an ancestor of this group of species. These results favor the view that 5S rRNA gene linkage to the rRNA cistron existed prior to the unlinked arrangement seen in most plants and animals.

The year 1991 marked 100 yr of coevolution research. I have reviewed the first 90 yr of this history. Three chronological phases are apparent: recognition of predictable associations among hosts and their parasites; search for patterns of association and their underlying causes, emphasizing either correlated biogeographic patterns or correlated phylogenies; and development of objective and repeatable methodologies for reconstructing and interpreting these patterns of association. Von Ihering, an outspoken anti-Darwinian, was undoubtedly the first to recognize and make use of predictable host-parasite associations. Kellogg and Fahrenholz, however, had more profound influence on subsequent generations, but in different directions. Kellogg attempted to meld natural selection with speciation by isolation. He also considered host specificity a component of coevolution, important but variable. His work laid the foundation for future research concentrated on biogeographic interpretations of host-parasite relationships. This emphasis and Metcalf's failed attempts to provide adequate mechanisms for reconstructing phylogenies reduced the biogeographic approach to an empirical research program in the hands of Manter. Fahrenholz, on the other hand, exposed to a strong anti-Darwinian sentiment, emphasized the importance of strict host specificity. This led to Eichler's formulation of the first 3 coevolutionary rules and the conclusion that host specificity was not a component but the cause of coevolution and ultimately the tautology inherent in the phylogenetic approach. All had to rely on 1 assumption, that host and parasite phylogenies were reflected in the taxonomic hierarchy. Hennig criticized this assumption and provided a method whereby phylogenies are reconstructed independently. Brooks melded this new phylogenetic method (cladistics) with an equally new biogeographic method (vicariance biogeography), providing the foundations for the modern macroevolutionary approach to studying host-parasite associations.

To develop a mouse model of coxsackievirus B3 (CVB3) myocarditis.Preliminary studies have indicated that mice infected with CVB3 alone erratically responded with viral myocarditis. Prospective evaluation of the effect of cyclophosphamide at two time intervals resulted in consistency for the development of myocarditis.Juvenile five- to nine-week-old male mice CD-1 type (Charles River Canada Limited).Infection with coxsackie B3 enterovirus. Pretreatment with cyclophosphamide two days and 4 h before inoculation of 0.2 or 0.15 mg/g. Animals were killed seven, nine, 28 and 63 days post infection.Following cyclophosphamide conditioning, a tissue response infection with CVB3 was uniformly observed. Virus, however, was infrequently recovered from the myocardium whereas myocarditis became chronic after 28 days.Pretreatment of juvenile mice with cyclophosphamide results in a reproducible model of viral myocarditis with chronic changes in the myocardium.

The effects of increasing heart rate by six different methods on cardiac function were investigated in 17 open-chest anesthetized dogs. Heart rate was increased approximately 30% by (1) right interganglionic nerve stimulation, (2) atrial pacing, (3) ventricular pacing, (4) atrioventricular sequential pacing, (5) right stellate ganglion stimulation, and (6) isoproterenol administration. During heart rate increases induced by atrial pacing left ventricular intramyocardial pressure, coronary blood flow, oxygen delivery per unit of myocardial oxygen consumption, and myocardial efficiency were unchanged. Ventricular pacing reduced left ventricular cavity and septal intramyocardial pressure, while circumflex coronary flow increased, resulting in reduced oxygen delivery relative to myocardial oxygen consumption. Similarly, atrioventricular sequential pacing increased circumflex coronary artery flow and myocardial oxygen consumption, and decreased septal intramyocardial pressure and oxygen delivery per unit of myocardial oxygen consumption. Right stellate ganglion stimulation and isoproterenol increased left anterior descending and circumflex coronary artery blood flow, intramyocardial pressure, and myocardial oxygen consumption. Estimated myocardial efficiency (left ventricle) was decreased by ventricular pacing and isoproterenol, and was unchanged by atrial pacing and right interganglionic nerve stimulation. Increases in heart rate induced by right interganglionic nerve stimulation did not alter myocardial oxygen consumption, or the index of cardiac efficiency. It is concluded that augmentation of heart rate by either ventricular or atrioventricular pacing impairs myocardial function so that there is a decrease of left ventricular efficiency and isoproterenol augments chronotropism and myocardial force relative to cardiac external work so there is a reduction in cardiac efficiency. In contrast, atrial pacing or right interganglionic nerve stimulation augments chronotropism such that myocardial oxygen consumption and efficiency are unchanged.

A total of 133 ancyrocephalid species found on Nearctic freshwater fishes have been named. Of these, 103 are now considered valid; 14 and 16 have been declared previously as synonyms or species inquirendae, respectively, and Urocleidus rarus Mizelle, 1940, is designated as a species inquirenda in the present work. A cladistic analysis, based on 13 binary and 4 multistate characters and 32 apomorphic character states was carried out. Generalized forms of Entobdella, Gyrodactylus, and Tetraonchus were used to generate a hypothetical outgroup taxon. Thirteen terminal taxa emerged. Of these, 3 (the articulating bar group, Ligictaluridus, and Onchocleidus sensu Wheeler and Beverley-Burton, 1989) have been recognized previously as monophyletic; 3 (Aethycteron, Lyrodiscus, and Salsuginus) were shown to be monophyletic in the present study; 3 (Leptocleidus, Macrohaptor, and Tetracleidus) are monotypic genera; and 4 were identified as unresolved assemblages that contain a number of species considered to be incertae sedis as well as those assigned to the following genera: Aristocleidus Mueller, 1936, Urocleidus sensu Suriano and Beverley-Burton, 1981, Cleidodiscoides Mayes and Miller, 1973, and Cleidodiscus sensu Beverley-Burton and Suriano, 1980. The resultant cladogram was 40 steps long with a consistency index of 0.80. The monophyly of the ingroup is supported by 5 synapomorphies. Comparison and mapping of the parasite cladogram with/onto a family-level cladogram of hosts indicated that the present data provided no unequivocal evidence of cospeciation. Some possible origins for the Nearctic ancyrocephalids are discussed, and the need for further taxonomic studies on the Holarctic ancyrocephalids to explore the possible sister-group relationship between the Nearctic and Eurasian faunas is emphasized.

We investigated coronary hemodynamics, myocardial utilization of circulating substrates (by coronary sinus catheterization), and overall use of oxidative fuels (by regional indirect calorimetry) in healthy adults during incremental atrial pacing (up to 159 +/- 9 beats/min), and during 25 min of recovery. Great cardiac vein flow (thermodilution) increased from 52 +/- 9 to 115 +/- 15 ml/min (P less than 0.001) with pacing; myocardial O2 uptake (301 +/- 53 to 593 +/- 71 mumol/min, P less than 0.001) and CO2 production (225 +/- 37 to 518 +/- 66 mumol/min, P less than 0.005) paralleled the pacing-induced rise in rate-pressure product (9.4 +/- 0.9 to 21.1 +/- 1.1 mmHg.beat. min-1.10(-3), P less than 0.001). During recovery, all the above variables returned to base line within 5 min, but myocardial O2 extraction remained depressed (67 +/- 2 vs. 71 +/- 3%, P less than 0.05). Circulating glucose uptake rose linearly with pacing (P less than 0.05) and remained above base line throughout recovery. By contrast, free fatty acid (FFA) uptake (10 mumol/min) did not increase with pacing and fell during recovery (P less than 0.01). Calorimetry, however, showed that net lipid oxidation exceeded FFA uptake throughout the study, whereas net carbohydrate oxidation was small at base line, rose significantly at maximal pacing (62% of myocardial energy output), and remained above base line during recovery (32% of energy output). In the basal state as well as during recovery, myocardial uptake of glucose equivalents (lactate plus glucose plus pyruvate) was in excess of carbohydrate oxidation, indicating nonoxidative disposal of these substrates.(ABSTRACT TRUNCATED AT 250 WORDS)

The short term reproducibility of exercise testing in 25 patients who had exercise induced ST segment elevation without baseline regional asynergy or a previous myocardial infarction, who had different responses to the dipyridamole test, was assessed. The patients performed a dipyridamole echocardiography test and a second exercise stress test. All underwent coronary arteriography. Seventeen patients had transient regional asynergy after dipyridamole (group 1) and either ST segment elevation (14 patients) or depression (three patients); a second group of eight had no asynergy and no electrocardiographic changes (group 2). The repeated exercise stress test was positive in 16 of the 17 patients of group 1 (11 with ST elevation and five with ST depression) and in two patients of group 2 (both had ST depression and one had coronary artery disease). The dipyridamole echocardiography test was positive in 17 of the 19 patients with coronary artery disease and was negative in all six patients without coronary artery disease. The repeated exercise stress test was positive in 17 of the 19 patients with coronary artery disease and in one patient without. The dipyridamole echocardiography test and a repeated exercise stress test, but not a single exercise stress test, identified coronary artery disease causing exercise induced ST segment elevation.

A biplane cineradiographic technique was used to measure deformation of the myocardium as indicated by small lead spheres implanted into the anterior left ventricular wall of anesthetized dogs. Deformation was resolved into nine separate components for each of the epicardial, middle, and endocardial layers. The data illustrate the mechanical effect of myocardial fiber orientation and the ability of muscle layers to deform differentially. In order to present an overview of all the results, the implications of the deformation components are discussed first separately and then in a coordinated fashion.

Morphologic and morphometric characters for 14 Entobdella species were reviewed. Entobdella brattstroemi, E. curvunca, E. rosaceus, E. squamula, and E. steingroeveri were found to be morphologically indistinguishable from E. hippoglossi, the type species, and are declared synonyms. A redescription of E. hippoglossi is presented. Allometry and the use of ratios to differentiate species are discussed. The nine valid Entobdella spp. belong to two monophyletic subgroups: the "hippoglossi" group (E. hippoglossi, E. soleae, and E. pugetensis) and the "diadema" group (E. diadema, E. bumpusii, E. corona, E. guberleti, E. apiocolpos, and E. australis). A key to species is included.

Canine myocardial CPK was partially purified and injected into 11 conscious mongreal dogs. From serial serum CPK measurements in each dog, mean Kd was calculated as 0.0047 +/- 0.0009 (+/- SD) min-1. Correlation coefficients indicated that CPK disappearance rate was well described by a single exponential expression. Kd measured on consecutive days in four dogs varied minimally. CPK distribution space ranged from 74 to 134% of plasma volume. Propranolol loading with 0.3 mg/kg or 2 mg/kg, followed by hourly maintenance doses, resulted in increased Kd in eight of ten dogs, mean Kd rising from .0048 min-1 to .0059 min-1 (P less than 0.02). Propranolol appeared to increase plasma volume but had no significant effect on the relationship of CPK distribution space to plasma volume. If the serial CPK technique were used to measure infarct size, using an average Kd, propranolol might produce artifactual reduction of infarct size measuremnt by increasing Kd and possibly by increasing plasma volume. The obligation to assess the effect upon CPK Kd and distribution space of an agent designed to limit infarct size is apparent.

Coronary venous pressure and coronary sinus flow in the canine heart were compared with intramyocardial, intraventricular, aortic, and coronary artery pressures. Stimulation of the thoracic vagus augmented coronary venous pressure, mean venous flow per systole, and coronary venous systolic resistance, but decreased the mean venous flow. Partial occlusion of the aorta augmented coronary venous pressure and coronary venous flow, while systolic coronary venous resistance remained unchanged. Adenosine increased peripheral and central coronary venous pressure and venous flow; it reduced peripheral coronary artery presure. Adenosine augmented flow per systole and reduced venous resistance more than the other interventions. Dipyridamole decreased left ventricular, aortic, and central coronary artery systolic pressures and systolic venous resistance. It increased the venous flow, mean flow per systole, and coronary venous pressure, even though intramyocardial pressure remained unchanged. Nitroglycerine elevated coronary venous pressure and flow, as well as venous flow per systole, even though it decreased left ventricular, aortic, and central coronary artery pressures. Nitroglycerine significantly decreased coronary venous resistance. It is concluded that coronary venous resistance may be an important resistive component to consider when the total coronary circulation is studied.

The effect of secretin on forearm metabolism (muscle compartment) was examined in the presence of low and high concentrations of insulin. Continuous infusions (30 min. duration) of secretin 12 ng/min. (SEC), insulin 160 ng/min. (INS) or these doses of insulin and secretin together (INS + SEC) were delivered into the brachial arteries of normal volunteers. SEC alone was without significant effect on forearm metabolism. INS as previously reported, stimulated glucose and potassium uptake and inhibited the output of some amino acids from the deep venous bed. The two hormones together (INS + SEC) increased maximum lactate (p less than 0.025) and alanine output (p less than 0.005) beyond that observed with INS alone. A marked calcium output occurred (p less than 0.001) with the combined infusion which was not observed with either hormone alone. Potassium metabolism with INS + SEC was similar to that observed with INS alone. These results suggest that these two hormones, acting in concert, stimulate glycolysis and net calcium efflux. This joint action of insulin and secretin may have a physiological role in the immediate postprandial period.

Coronary venous pressure was measured in two sites in the canine heart. Central coronary venous pressure was that pressure recorded by a catheter in an epicardial coronary vein directed antegrade towards the coronary sinus. This pressure was 6 ± 1/0.2 ± 0.6 mmHg (1 mmHg = 133.322 Pa). Peripheral coronary venous pressure was recorded by a catheter in an epicardial vein which was directed towards the apex. It was 27 ± 5/8 ± 2 mmHg. Simultaneous measurement of peripheral coronary artery and vein pressures demonstrated similar pressure wave forms with peak pressures during systole. Peripheral coronary venous pressure was similar if measured from a side branch leading to the major epicardial veins or via a catheter placed retrograde in a major epicardial vein. Thus artifact of measurement caused by antegrade catheter placement was negligible. During norepinephrine administration, venous pressures were significantly increased. These data suggest that coronary venous pressures are higher than is generally assumed and that intramyocardial pressure has an important effect upon coronary venous pressure.

A phylogenetic (cladistic) analysis was conducted for 15 ancyrocephalid (Monogenea) species parasitizing North American freshwater fishes. The analysis was based on 10 (four binary and six multistate) characters. Vaginal characters were not included due to insufficient data. The resultant, most parsimonious cladogram was 38 steps long with a consistency index of 0.921: reduced consistency was attributed to two cases of homoplasy and one reversal. Three unresolved polychotomies were observed. Three clades were recognized: clade 1 — Actinocleidus species; clade 2 — Anchoradiscoides, Anchoradiscus, Clavunculus species and Syncleithrium; and clade 3 — Crinicleidus species. The protocol for and implications of character identification and polarisation and the establishment of transformation series were discussed.

SUMMARY: A satellite band in CsCl-bisbenzimide density gradients of Pythium diclinum DNA was found to consist of ribosomal DNA (rDNA) repeating units with a complexity of 10.3 kilobases (kb). Similar satellite bands were also obtained from a morphologically diverse selection of species from the Pythiaceae: Pythium torulosum (10.4 kb), Pythium irregulare (11.8 kb), Pythium anandrum (10.6 kb), Pythium paddicum (10.6 kb) and Phytophthora cryptogea (11.2 kb). Physical maps were constructed using seven endonuclease restriction enzymes and the maps were aligned on the basis of nine conserved restriction sites in a 6 kb region which was shown to be homologous to a DNA plasmid probe containing ribosomal genes from Neurospora crassa. A map of the rDNA region in Apodachlya pyrifera (10.1 kb), a species external to the Pythiaceae (Leptomitales), was also constructed to serve as a taxonomic reference. Percentage sequence divergence values indicated that P. diclinum and P. torulosum are closely related, but not identical. P. anandrum and P. irregulare also appeared closely related in spite of morphological differences. P. paddicum and Phytophthora cryptogea were the most outlying of the six species of Pythiaceae, but all six species formed a tight cluster when considered against A. pyrifera.

The response to a bolus injection of nitroglycerine, adenosine, nifedipine, and dipyridamole of the canine systemic as well as coronary artery and venous circulations was observed and contrasted. Particular attention was paid to the time of change of pressures and flows and to changes in oxygen extraction by the myocardium induced by the pharmacological agents. The dosages of vasodilators used were selected so that no significant change in aortic blood flow occurred. Nitroglycerine and adenosine caused a rapid and similar vasodilation in the coronary circulation. Oxygen extraction was not altered by nitroglycerine, but was decreased by adenosine. The onset time of the vasodilation produced by either nifedipine or dipyridamole was similar, but the time to peak action was much slower for dipyridamole. As well, the effect of dipyridamole on intramyocardial and left intraventricular pressures was more delayed than that following the injection of the other agents. Oxygen extraction was reduced by nifedipine and dipyridamole. These results indicate that pharmacological vasodilating agents can affect coronary arteries, coronary veins, and myocardial oxygen extraction differently.

Ligictaluridus Beverley-Burton, 1984 has been proposed for ancyrocephalid monogeneans found on North American catfishes (Siluriformes: Ictaluridae). The genus is characterized by the following: penis curved, sclerotized, tubular; accessory piece with proximally articulating base and distally projecting limb of varying size and shape; dorsal and ventral hamuli with slender, curving shaft, dorsal hamuli smaller than ventral; dorsal and ventral transverse bars bowed with flange projecting medianly; larval hooks of variable size and shape. The type species, Ligictaluridus pricei (Mueller, 1936) Beverley-Burton, 1984, together with L. monticellii (Cognetti de Martiis, 1924) n. comb., L. floridanus (Mueller, 1936) Beverley-Burton, 1984, and L. mirabilis (Mueller, 1937) n. comb., is redescribed. The finding of L. monticellii on Ictalurus nebulosus taken in Lake Erie, Ontario, is a new record for North America. All the above species, as well as L. bychowskyi (Price and Mura, 1969) n. comb., are transferred from Cleidodiscus Mueller, 1934. The effects of variable cover-slip pressure and different preservation techniques on the morphology of some of the sclerotized structures are discussed.

Intramyocardial, ventricular, aortic, and central and peripheral coronary artery as well as peripheral and central coronary venous pressures were measured simultaneously in dog hearts. A gradient of coronary vascular pressures was detected and quantitated. Stellate stimulation increased all pressures. Isoproterenol induced outflow tract obstructions so that aortic and central coronary artery pressures were unchanged while the other pressures increased. Vagal stimulation dissociated the intramyocardial venous pressure relationship in as much as arterial pressures decreased while epicardial coronary venous pressure was increased. These data suggest that coronary venous pressure in response to sympathetic stimulation increases as intramyocardial pressure increases. However, vagal stimulation permits a dissociation of these effects suggesting that coronary venous pressure regulation is complex.

Intravenous perhexiline maleate in a canine preparation with fixed coronary flow increases coronary diastolic pressure. It also redistributes coronary flow so as to preserve endocardial flow. Myocardial oxygen consumption was reduced and lactate uptake enhanced by the drug. It had no effect upon the threshold for ischemic-induced left ventricular failure.

Spatial heterogeneity, the region-to-region variation in flow at an instant, and temporal heterogeneity, the time variation of flow in a small region of myocardium, were investigated with radioactive labeled microspheres in 111 regions of left ventricular myocardium. The error of the method was measured by simultaneously injecting four differently labeled microspheres (15 +/- 5 (SD) micron). The coefficient of variation (CV) was 6.5 +/- 1.0%. Spatial variation with autoregulation intact was 21.7 +/- 1.4% (CV); with autoregulation abolished and low perfusion pressure, it was 34.3 +/- 3.7%; and with normal perfusion pressure, 30.8 +/- 6.4% (differences not significantly). This degree of variation was similar in the entire left ventricle and its layers. Forces which tended to cause vessel closure (low perfusion pressure, ventricular systolic pressure, and ventricular diastolic pressure) tended to increase CV. Temporal heterogeneity as measured by 20-s intervals between microsphere injections was 11.1 +/- 1.0% (CV) with autoregulation, 9.8 +/- 1.3% (P less than 0.05) with autoregulation abolished, and 8.4 +/- 0.8% (P less than 0.05) when perfusion pressure was restored. A periodicity of flow cycles of 30-90 s was suggested by the data. These results suggest that spatial heterogeneity is less influenced by autoregulation than by hydraulic considerations, whereas temporal heterogeneity is a component of autoregulation.

1. The forearm perfusion technique was used to study the effect of intra-arterial injections of ethanol with or without digoxin on the metabolism and electrolyte flux of forearm tissues in normal male volunteers. 2. In six subjects infusion of ethanol alone (2·9 mg/min over 30 min) resulted in no alterations of forearm blood flow, O2 consumption, carbohydrate metabolism, or flux of potassium and calcium. Although there was no change in extraction of [14C]oleic acid, a significant net output of oleic and total free fatty acids was observed from both deep venous and superficial venous systems. 3. In six subjects the intra-arterial infusion of [3H]digoxin (0·09 μg/min with ethanol, 2·9 mg/min over 30 min) resulted in no alteration of forearm blood flow. During the steady state achieved after 5–8 min of perfusion, 50·3% of the calculated local arterial plasma digoxin concentration of 2·73 μg/l was extracted by the deep venous system with a significant increase in glucose extraction. The respiratory quotient and fractional utilization of O2 by glucose increased. No change in extraction of [14C]oleic acid from arterial blood was observed. However, the net output of oleic and total free acids from both deep and superficial venous systems was insignificant in comparison with that observed in the ethanol control subjects. The changes in K+ flux were similar to those noted in the ethanol group. In the post-digoxin period there was a significantly increased uptake of Ca2+ by forearm tissues. 4. This is the first demonstration of the stimulatory effects of digoxin on glucose metabolism, the antilipolytic effects of this drug and its effect on Ca2+ fluxes in vivo in man.

Thylacicleidus serendipitus n.gen., n.sp. is proposed for material from the green puffer, Tetraodon fluviatilis Hamilton-Buchanan, 1822, from Indonesia. Thylacicleidus is distinguished from other ancyrocephalid genera by the following combination of characters: a distinctive tegumentary structure, with the body surface covered with numerous small transverse ridges; a sinistral vaginal opening; hamuli with a shortened shaft and heavy blade; ventral hamuli with reduced deep root; ventral transverse bar with lateral extremities sharply deflected posteriorly; and an association with hosts of the family Tetraodontidae. The only ancyrocephalid genus previously recorded from tetraodontids is Haliotrema Johnston and Tiegs, 1922. The status of Haliotrema is discussed and it is suggested that, because of morphological variability within Haliotrema and an extremely wide host spectrum, the genus is almost certainly polyphyletic and in need of taxonomic revision.

As a result of further studies following the review of the genus Ligictaluridus by G. J. Klassen and M. Beverley-Burton, we propose Ligictaluridus posthon n. sp. for ancyrocephalid monogeneans found on Noturus flavus (Siluriformes: Ictaluridae) taken in Ontario. Ligictaluridus posthon is most similar to the type species, L. pricei (Mueller, 1936) Beverley-Burton, 1984 but is distinguished by a stouter penis, with a diameter to length ratio of ~1:6 (~1:18 in L. pricei), larger hamuli, and an apparent specificity for stonecats (Noturus flavus).

A linear 7.4-kilobase plasmid designated pTCT was isolated from mycelium of Tilletia controversa Kühn, the causal agent of dwarf bunt of wheat. Linearity was determined by construction of a physical map using eight restriction enzymes and by both 5′ and 3′ exonuclease digestion. pTCT is not homologous to ribosomal genes, nor is it homologous to any sequences in the total DNA of sporidia of Ustilago hordei (isolates 965 and 966) or urediosporelings of Puccinia graminis f.sp. tritici (race C36(48)).

The purpose of this investigation was to quantitate the rate of uric acid production in patients following acute myocardial infarction. In previous reports (Spring et al. 1960) it was observed that serum uric acid levels could be elevated following acute myocardial infarction. In view of other metabolic changes which have been observed such as the increased excretion of catecholamines and their metabolites and changes of glucose tolerance and lipid metabolism, it seemed adviseable to investigate abnormalities of uric acid metabolism in terms of pool size and turnover rates. 7 male patients who had had uncomplicated myocardial infarctions were admitted to the study following informed consent. The criteria of myocardial infarction were dependent upon clinical, electrocardiographic and biochemical enzyme changes. The patients were selected to exclude those with pre-existing disease and were restricted to those patients whose post-operative course did not require the administration of drugs particularly diuretics. The patients were admitted to an investigative ward from the coronary care unit between the 2nd and 5th day following infarction.

1. Normal human urine contains small amounts (< 4 mg/g of creatinine) of 2-ethylhydracrylic acid, formed, we believe, by a previously undisclosed endogenous catabolic pathway for the oxidation of a newly described series of R metabolites of isoleucine. 2. Urinary excretion of 2-ethylhydracrylic acid is variably increased in defects of isoleucine oxidation at distal steps in the catabolic pathway (3-oxoacyl-CoA thiolase deficiency and methylmalonyl-CoA mutase deficiency) and is diminished when proximal steps of the oxidative pathway are blocked as in branched-chain oxo acid decarboxylase deficiency (‘maple-syrup-urine’ disease). 3. Precursors of R-pathway metabolites [R(-)-2-methylbutyrate and 2-ethylacrylate] lead to increased 2-ethylhydracrylate excretion in the mammal(rat, rabbit and dog); the corresponding S metabolites [S(+)-2-methylbutyric acid and tiglic acid], when given in equimolar amounts, have little effect on its excretion, suggesting that little or no interconversion between S and R metabolites occurs in vivo. 4. Studies with 2H-labelled precursors indicate that conversion of R 2-methylbutyrate into 2-ethylhydracrylic acid occurs by a direct pathway (apparently via 2-ethylacrylic acid). 5. The further oxidation of 2-ethylhydracrylic acid to ethylmalonic acid was demonstrated, and may be analogous to S-metabolite oxidation via methyl malonate. 6. Valine metabolites do not interact with the R-isoleucine pathway under the conditions of these experiments in vivo.