Mycotic dermatitis in an Atlantic white-sided dolphin, a pygmy sperm whale, and two harbor seals.

An Atlantic white-sided dolphin (Lagenorhynchus acutus), a pygmy sperm whale (Kogia breviceps), 2 harbor seals (Phoca vitulina) developed raised, firm, erythematous, cutaneous nodules that were most prominent on their heads, trunks, and on the caudal portions of their bodies. Prior to the onset of the condition, all 4 animals may have been stressed by factors such as being stranded on a beach, being transported long distances, or being relocated locally. Microbial culturing of the lesions on multiple media yielded fungal isolates containing conidia characteristic of Fusarium spp. Hyphae consistent with those of an ascomycete were evident on histologic examination of lesions. In each treated animal, the dermatitis resolved 3 to 4 weeks after completing treatment with ketoconazole. Fusarium spp may be opportunistic invaders of the skin of marine mammals that have decreased immunocompetence or integumentary compromise.

Isolation of Candida albicans and halophilic Vibrio spp. from aquatic birds in Connecticut and Florida.

Halophilic vibrios were recovered from feces of six types of aquatic birds (gulls, pelicans, Canada geese, swans, egrets, cormorants) from Connecticut and/or Florida shorelines. Candida albicans was isolated from gulls and Canada geese in Connecticut and from gulls and cormorants in Florida.

Bandwidth and tuning range of an ArF laser measured by 1 + 1 resonantly enhanced multiphoton ionization of NO.

The tuning range and bandwidth of an ArF laser were measured using 1 + 1 resonantly enhanced multiphoton ionization of NO. Operated as an injection-seeded oscillator/amplifier combination, the tuning range was 51,560-51,810 cm(-1); operated with single pass amplification of the oscillator, the tuning range was 51,560-51,765 cm(-1). In both cases, the laser bandwidth, determined from the linewidth, was 0.21 +/- 0.06 cm(-1). Rotational lines in the beta(7,0), gamma(3,O), and epsilon(0,1) bands were observed including several previously unreported lines.

Clostridium perfringens as the cause of death of a captive Atlantic bottlenosed dolphin (Tursiops truncatus).

A previously healthy captive female bottlenosed dolphin (Tursiops truncatus) died suddenly. At necropsy, Clostridium perfringens was isolated from dorsal muscle, blood, left heart ventricle, thoracic fluid, and abdominal fluid. An identical strain was recovered from pool water. A male dolphin in the same pool had inflicted several "rake" marks on the dorsal surface of the female. Water-borne bacteria probably entered these lesions which served as the focus for anaerobe penetration and spread.

A note on the experimental uptake and clearance of Candida albicans in a young captive gull (Larus sp.).

An immature gull (Larus sp.) was placed in captivity after having been kept as a pet for several weeks and allowed to roam freely. On day one of captivity, bird feces showed the presence of Candida albicans but the yeast was absent for the next 16 days. The gull was fed only yeast-free water and fish. On day 17 only, the bird was fed fish containing C. albicans which had been isolated from a wild gull. The yeast was present in all fecal samples (2-4 per day) for the next 13 days. Beginning on day 26 and irregularly thereafter the bird was fed fish containing 100-200 mg of ketoconazole. Feces continued to show the presence of C. albicans but only sporadically because the bird continued to reinfect itself, probably by contaminating the water supply via feet or feces. After protecting the water, yeast presence in feces decreased. The gull was released on day 57; feces that day were negative for C. albicans. During the experimental period the bird displayed no clinical symptoms of candidiasis. The observations indicated that one exposure to C. albicans was sufficient to establish the carrier state and that the possibility exists for shedding a potentially dangerous microorganism over a large geographical area.

Candidiasis in captive pinnipeds.

Diagnosis, treatment, and possible pathogenesis of candidiasis were studied in 5 species of pinnipeds in captivity: gray seal (Halichoerus grypus), harbor seal (Phoca vitulina), northern fur seal (Callorhinus ursinus), California sea lion (Zalophus californianus), and northern elephant seal (Mirounga angustirostris). The animals were kept outdoors in a freshwater exhibit. Candidiasis was characterized by purulent nasal discharge, inflammation of the lips at the mucocutaneous junction, periocular alopecia, vaginitis, and dermatitis. Administration of ketoconazole at dosages of 5 mg/kg BID and 10 mg/kg SID controlled the disease. Wild gulls were suspected as vectors of Candida albicans.

Bacteriology of the teeth from a great white shark: potential medical implications for shark bite victims.

Bacteria were cultured for the first time from the teeth of a great white shark (Carcharodon carcharias). Isolates included Vibrio alginolyticus, Vibrio fluvialis, Vibrio parahaemolyticus, and other genera. All are common in the marine environment and some may be associated with wound infections in humans. Shark bite lacerations may serve as a source of these potentially infectious bacteria, particularly Vibrio spp., and should be treated immediately. Antibiotic susceptibility patterns are shown for representatives of Vibrio isolates and indicate that a variety of new agents may be appropriate chemotherapy for shark bite victims.

Coronary hemodynamics and subendocardial perfusion distal to stenoses.

We compared distal coronary hemodynamics and regional myocardial perfusion in anesthetized dogs in the presence of a single or two coronary artery stenoses in series. After application of either a single or two stenoses on the left anterior descending coronary artery, regional myocardial blood flow was measured with radioactive microspheres. Moderate degrees of single-vessel stenosis (no change in resting coronary blood flow but reduction in reactive hyperemic response of 70%) resulted in no significant change in regional myocardial perfusion at rest despite a pressure drop across the stenosis of 24 +/- 3 mm Hg. When two such stenoses were applied in series, there was a 91% decrease in reactive hyperemia, a significant reduction in resting diastolic coronary blood flow and a 51 +/- 7 mm Hg pressure drop across the two stenoses. Alone, each stenosis produced no change in regional myocardial perfusion; however, together the two stenoses resulted in a significant decrease in subendocardial blood flow and a redistribution of transmural perfusion within the ischemic zone favoring the subepicardium (endo/epi from 0.95 +/- 0.03 to 0.72 +/- 0.03). The results indicate that whereas resting subendocardial perfusion is not significantly affected by moderate degrees of a single coronary artery stenosis, multiple stenoses of the same severity may dramatically reduce subendocardial perfusion.

Occurrence ofCandida albicans in fresh gull feces in temperate and subtropical areas.

The occurrence ofCandida albicans in fresh gull (Larus spp.) feces was compared in temperate and subtropical locations. Of 239 fresh samples, 133 were obtained in southeastern Connecticut and 106 from different sites on the southeastern and central western coasts of Florida. Overall, 60% of all feces containedC. albicans. Of the Connecticut samples, 78% were positive, whereas 38% of the Florida samples revealed the presence of the yeast. Only 1 of 24 samples of fresh brown pelican feces containedC. albicans. Differences inC. albicans occurrence in birds in various locations was ascribed to variations in habitat and feeding behavior. Samples of water from a municipal reservoir in Connecticut were routinely positive, with an average cell density of 20/liter. Two fresh gull samples obtained on the reservoir bank containedC. albicans at an average cell concentration of 5, 200/g. The frequency ofC. albicans in gull droppings was higher than reported by others, and the yeast is common in temperate waters. These findings have important public health implications.

Candidiasis in captive cetaceans.

Disseminated Candida albicans infections were found or suspected in 4 captive cetaceans. Ketoconazole at a dosage of 2.5 mg/kg, BID, administered orally for 18 days, followed by 8 biweekly oral doses of levamisole hydrochloride at the rate of 9 mg/kg, resulted in regression of clinical signs of candidiasis in an adult male Atlantic bottlenose dolphin (Tursiops truncatus). A higher dosage of ketoconazole (6 mg/kg, BID) was effective in eliminating the shedding of C albicans from an adult male belukha whale (Delphinapterus leucas). A juvenile female harbor porpoise (Phocoena phocoena) treated with nystatin died with disseminated candidiasis, as did a juvenile male longfinned pilot whale (Globicephala melaena) treated with nystatin and levamisole. Three other adult bottlenose dolphins, a juvenile female belukha whale, and a female Commerson's dolphin (Cephalorhynchus commersonii) kept in the same water system never had evidence of candidiasis. A 5th bottlenose dolphin (an adult female) was culture-positive on 1 occasion, but never had signs of the disease.

Nonstaining (KOH) method for determination of gram reactions of marine bacteria.

A rapid nonstaining (KOH) method for the determination of the Gram reactions of bacteria is described, and its application to marine isolates is discussed. All gram-positive and gram-negative results obtained by Gram staining were confirmed by the KOH method. Gram-variable bacteria produced equivocal results.

Role of autoregulation in the beneficial action of propranolol on ischemic blood flow distribution and stenosis severity in the canine myocardium.

The effect of propranolol (0.1 mg/kg i.v.) on distal coronary pressure (DCP), distal bed (DR) and stenosis resistances (SR) and regional myocardial blood flow [endocardial-epicardial (endo/epi)] was studied in two groups of anesthetized dogs with a severe stenosis of the left circumflex coronary artery. In group 1, the ability of the DR to autoregulate was left intact, whereas in group 2, the DR was maximally dilated by pretreatment with the coronary vasodilator, chromonar. Despite similar global hemodynamic effects in both groups after propranolol treatment significant differences were observed in the ischemic area. In group 1, propranolol produced a significant increase in subendo blood flow, endo/epi and DCP in the ischemic region. In addition, DR (1.7 +/- 0.4 to 3.3 +/- 0.6 U) increased and SR decreased (3.4 +/- 0.5 to 1.7 +/- 0.3 U) significantly. In group 2, the changes in endo/epi, DCP, DR and SR were prevented by maximal vasodilation. These results suggest that the favorable changes produced by propranolol on ischemic myocardium are the result of a restoration of the ability of the resistance vessels to autoregulate. This allows for a passive decrease in coronary arteriolar dilation which results in an increase in DR and DCP and a decrease in SR. The increase in DCP may also contribute to the increase in ischemic subendo blood flow after propranolol.

Separation of overlap and collateral perfusion of ischemic canine myocardium: important considerations in the analysis of vasodilator-induced coronary steal.

Coronary steal was studied in dogs with a left anterior descending (LAD) coronary artery occlusion by use of a special technique to exclude contamination from overlapping circulations with true collateral blood flow. Different degrees of vasodilation in nonischemic myocardium were produced by the selective coronary dilator, chromonar, at a constant heart rate and aortic blood pressure. A map of the ischemic area was made, and criteria used to identify ischemic tissue samples included: (1) all samples within the LAD perfusion area, as defined by a dye technique; (2) tissue samples with blood flows less than 25% normal area flow; (3) samples from within the central ischemic zone; and (4) tissue samples with overlap blood flow less than 2% normal area flow. When criteria 1 and 2 were used to identify ischemic myocardium, chromonar (5 and 7.5 mg/kg, i.v.) produced no change in ischemic blood flow. On the other hand, when tissue samples from the central ischemic zone or those which had less than 2% overlap flow (criteria 3 and 4) were used to identify ischemic myocardium, chromonar produced a dose-related decrease (p less than 0.01) in transmural collateral perfusion (25 +/- 4 and 33 +/- +/- 5;33 +/- 3 and 41 +/- 6%, respectively). Other indices of collateral function, peripheral coronary pressure (23 +/- 4 and 25 +/- 3%), retrograde flow (20 +/- 3 and 26 +/- 4%), and retrograde conductance (21 +/- 4 and 30 +/- 4%), also decreased significantly. These results indicate that moderate to maximal coronary vasodilation produces a true coronary steal in the absence of changes in aortic pressure and heart rate. In addition, these data demonstrate that significant amounts of overlap flow are contained in superior, inferior, and lateral borders of the ischemic zone, and that strict criteria to identify ischemic myocardium are needed when studying the effect of drugs on true coronary collateral blood flow.

Distribution of methanogenic and sulfate-reducing bacteria in near-shore marine sediments.

The distribution of methanogenic and sulfate-reducing bacteria was examined in sediments from three sites off the coast of eastern Connecticut and five sites in Long Island Sound. Both bacterial groups were detected at all sites. Three distributional patterns were observed: (i) four sites exhibited methanogenic and sulfate-reducing populations which were restricted to the upper 10 to 20 cm, with a predominance of sulfate reducers; (ii) three sites in western Long Island Sound exhibited a methanogenic population most abundant in sediments deeper than those occupied by sulfate reducers; (iii) at one site that was influenced by fresh groundwater, methanogens and sulfate reducers were numerous within the same depths; however, the number of sulfate reducers varied vertically and temporally with sulfate concentrations. It was concluded that the distributions of abundant methanogenic and sulfate-reducing bacteria were mutually exclusive. Methanogenic enrichments yielded all genera of methanogens except Methanosarcina, with the methanobacteria predominating.

Changes in ischemic blood flow distribution and dynamic severity of a coronary stenosis induced by beta blockade in the canine heart.

The effects of equipotent beta 1-receptor-blocking doses of propranolol, metoprolol and sotalol on distal coronary pressure, stenosis resistance and regional myocardial blood flow (endo/epi) were studied in anesthetized dogs with a severe noncircumferential stenosis of the left circumflex coronary artery. No significant differences between the three beta blockers were observed for overall hemodynamics and regional myocardial blood flow. After drug treatment, subendocardial blood flow (0.47 +/- 0.05 to 0.78 +/- 0.05 ml/min/g) and endo/epi (0.67 +/-0.04 to 1.18 +/- 0.04) increased significantly (p less than 0.05) in the ischemic region. These changes were associated with a marked increase in distal coronary perfusion pressure and a decrease in heart rate. Resistance across the stenosis decreased significantly (p less than 0.05) after beta-receptor blockade (3.2 +/- 0.3 to 1.4 +/- 0.2 units). Atrial pacing to control heart rate only partially attenuated these changes. These results suggest that a favorable redistribution of ischemic blood flow after beta blockade is the result of an increase in distal diastolic pressure-time index and an autoregulation-induced increase in distal bed vascular resistance due to a decrease in myocardial oxygen demand associated with beta blockade. The latter effect also resulted in a decrease in the dynamic severity of a proximal coronary stenosis.

Transmural distribution of blood flow during activation of coronary muscarinic receptors.

The role of coronary muscarinic receptors in the distribution of transmural blood flow across the left ventricular wall of the working heart was studied in anesthetized open-chest dogs. Tissue blood flow in subepicardium, midmyocardium, and subendocardium was determined with radioactive microspheres before and during activation of muscarinic vasodilator receptors by intracoronary infusions of acetylcholine. Myocardial and coronary vascular beta-receptors were blocked by sotalol (2.0 mg/kg iv). Equivalent submaximal coronary vasodilator doses of acetylcholine and adenosine were compared for effects on transmural blood flow. Intracoronary infusions of acetylcholine (5.0 and 10.7 micrograms/min) produced a dose-related increase in the subendocardial-subepicardial blood flow ratio (endo/epi) from 1.07 to 1.32 and 1.57, respectively. A progressively larger decrease in coronary vascular resistance occurred in the subendocardium than midmyocardium or subepicardium following acetylcholine administration. In contrast, intracoronary administration of adenosine (54.4 micrograms/min) produced no change in endo/epi. Atropine effectively blocked acetylcholine-induced coronary vasodilation but not vasodilation produced by adenosine. Neither agent affected heart rate, left ventricular pressure, coronary perfusion pressure, or myocardial contractility. These results suggest that activation of muscarinic coronary vasodilator receptors redistributes blood flow preferentially to the subendocardium independent of cardiac mechanical influences.

Effects of sotalol and vagal stimulation on ischemic myocardial blood flow distribution in the canine heart.

The purpose of the present study was to compare the effect of equivalent decreases in heart rate produced by sotalol and bilateral vagal stimulation on regional myocardial blood flow and coronary perfusion pressure distal to a severe stenosis of the left circumflex coronary artery in anesthetized dogs. Tissue blood flow was measured with radioactive microspheres (15 mu). Vagal stimulation or beta adrenergic blockade produced by sotalol (1.0 mg/kg i.v.) reduced heart rate approximately 35 beats/min. This decrease in rate was accompanied by nearly equivalent increases (P less than 0.05) in diastolic perfusion time and subendocardial blood flow and in the ischemic region. Both interventions also significantly increased the oxygen supply-demand balance (distal diastolic pressure time index divided by the tension time index) in the ischemic region. These values returned to control after cessation of vagal stimulation or during atrial pacing to predrug heart rate. Coronary perfusion pressure distal to the stenosis increased significantly only in the sotalol-treated group. These results suggest that a decrease in heart rate and increase in diastolic perfusion time are important factors in the favorable redistribution of ischemic myocardial blood flow and increase in the oxygen supply-demand balance observed after beta adrenergic blockade with sotalol or after vagal stimulation. Whether these beneficial actions are solely due to the prolonged diastolic perfusion period or to reduced oxygen demand and a return to autoregulation in the ischemic area cannot be determined with certainty.