No more time to stay 'single' in the detection of Anisakis pegreffii, A. simplex (s. s.) and hybridization events between them: a multi-marker nuclear genotyping approach.

A multi-marker nuclear genotyping approach was performed on larval and adult specimens of Anisakis spp. (N = 689) collected from fish and cetaceans in allopatric and sympatric areas of the two species Anisakis pegreffii and Anisakis simplex (s. s.), in order to: (1) identify specimens belonging to the parental taxa by using nuclear markers (allozymes loci) and sequence analysis of a new diagnostic nuclear DNA locus (i.e. partial sequence of the EF1 α-1 nDNA region) and (2) recognize hybrid categories. According to the Bayesian clustering algorithms, based on those markers, most of the individuals (N = 678) were identified as the parental species [i.e. A. pegreffii or A. simplex (s. s.)], whereas a smaller portion (N = 11) were recognized as F1 hybrids. Discordant results were obtained when using the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) of the internal transcribed spacer (ITS) ribosomal DNA (rDNA) on the same specimens, which indicated the occurrence of a large number of 'hybrids' both in sympatry and allopatry. These findings raise the question of possible misidentification of specimens belonging to the two parental Anisakis and their hybrid categories derived from the application of that single marker (i.e. PCR-RFLPs analysis of the ITS of rDNA). Finally, Bayesian clustering, using allozymes and EF1 α-1 nDNA markers, has demonstrated that hybridization between A. pegreffii and A. simplex (s. s.) is a contemporary phenomenon in sympatric areas, while no introgressive hybridization takes place between the two species.

A complex pattern of mantle flow in the Lau backarc.

Shear-wave splitting analysis of local events recorded on land and on the ocean floor in the Tonga arc and Lau backarc indicate a complex pattern of azimuthal anisotropy that cannot be explained by mantle flow coupled to the downgoing plate. These observations suggest that the direction of mantle flow rotates from convergence-parallel in the Fiji plateau to north-south beneath the Lau basin and arc-parallel beneath the Tonga arc. These results correlate with helium isotopes that map mantle flow of the Samoan plume into the Lau basin through an opening tear in the Pacific plate.

Genetic relationships among species of Contracaecum Railliet & Henry, 1912 and Phocascaris Höst, 1932 (Nematoda: Anisakidae) from pinnipeds inferred from mitochondrial cox2 sequences, and congruence with allozyme data.

The genetic relationships among 11 taxa, belonging to the genus Contracaecum (C. osculatum A, C. osculatum B, C. osculatum (s.s.), C. osculatum D, C. osculatum E, C. osculatum baicalensis, C. mirounga, C. radiatum, C. ogmorhini (s.s.), C. margolisi) and Phocascoris (Phocoscris cystophorae), parasites as adults of seals, were inferred from sequence analysis 1519 bp) of the mitochondrial cytochrome c oxidase subunit II (mtDNA cox2) gene. Phylogenetic analyses obtained from Parsimony (MP) and Neighbour-Joining (NJ) K2P distance values generated similar topologies, each well supported at major nodes. All analyses delineated two main clades: the first encompassing the parasites of the phocid seals, i.e. the C. osculatum species complex, C. osculatum boicolensis, C. mirounga and C. radiatum, with the latter two species forming a separate subclade; the second including the parasites of otarids, i.e. C. ogmorhini (s.s.) and C. margolisi. An overall high congruence between mtDNA inferred tree topologies and those produced from nuclear data sets (20 allozyme loci) was observed. Comparison of the phylogenetic hypothesis here produced for Controcaecum spp. plus Phocascaris with those currently available for their definitive hosts (pinnipeds) suggests parallelism between hosts and parasite phylogenetic tree topologies.

Myocardial potassium loss after acute coronary occlusion in humans.

Animal studies have established that there is a rapid increase in extracellular potassium concentration in myocardial tissue after the onset of ischemia. To study this phenomenon in humans, coronary sinus plasma potassium concentration was measured in five patients undergoing therapeutic coronary angioplasty. Recordings were obtained during a total of 22 coronary artery occlusions lasting between 5 and 50 seconds. Though little change was observed during angioplasty balloon inflation, all occlusions that lasted more than 15 seconds were followed by a transient elevation in coronary sinus potassium concentration of between 0.18 and 1.55 mmol X liter-1. The majority of occlusions (n = 17) were not accompanied by chest pain, electrocardiographic (ECG) changes or alteration of heart rate. The increase in coronary sinus potassium concentration after angioplasty balloon deflation is attributable to a washout of accumulated extracellular potassium during reperfusion. Redistribution of human myocardial potassium occurs within 15 seconds of the onset of myocardial ischemia and may be an important factor accounting for early electrophysiologic changes.

A closed eye contact lens model of corneal inflammation. Part 1: Increased synthesis of cytochrome P450 arachidonic acid metabolites.

PURPOSE: To characterize a model of contact lens-induced corneal inflammation in the closed eye, with respect to inflammatory parameters and the metabolism of arachidonic acid by homogenates of the corneal epithelium. METHODS: Rabbit eyes were fitted with extended wear etafilcon A (58% water) hydrogel contact lenses in stacked fashion (two lenses per eye), followed by a silk suture tarsorrhaphy of approximately 90%. The anterior surface was analyzed over a 9-day period for inflammatory events through slit lamp biomicroscopy, subjective inflammatory scoring, corneal pachymetry, and corneal epithelial [1-(14)C]-arachidonic acid metabolism. RESULTS: Hydrogel contact lens wear in the closed eye resulted in a progressive anterior surface inflammatory response correlated over time (r = 0.999). Central corneal thickness progressively increased and was also correlated to the inflammatory score (r = 0.995). [1-(14)C]-arachidonic acid metabolism by homogenates of the corneal epithelium resulted in the time-dependent formation of two major products, 12-hydroxyeicosatetraenoic acid (12-HETE) and 12-hydroxyeicosatrienoic acid (12-HETrE). Correlations were established between the synthesis of 12-HETE and 12-HETrE, the subjective inflammatory score (r = 0.963) and the progressive increase in corneal thickness (r = 0.971), over 9 days. CONCLUSIONS: With this model of contact lens wear, eicosanoid synthesizing capacity of the corneal epithelium showed a time-dependent increase in the production of 12-HETE and 12-HETrE strongly correlating to the in situ inflammatory response. The relationship between 12-HETE and 12-HETrE synthesis and the degree of anterior surface inflammation implicate these eicosanoids, among others, as mediators of the inflammatory response to hydrogel contact lens wear in the closed eye.

Genetic markers in ribosomal DNA for the identification of members of the genus Anisakis (Nematoda: ascaridoidea) defined by polymerase-chain-reaction-based restriction fragment length polymorphism.

Polymerase-chain-reaction-based restriction fragment length polymorphism analysis was performed to establish genetic markers in rDNA, for the identification of the three sibling species of the Anisakis simplex complex and morphologically differentiated Anisakis species, i.e. Anisakis physeteris, Anisakis schupakovi, Anisakis typica and Anisakis ziphidarum. Different restriction patterns were found between A. simplex sensu stricto and Anisakis pegreffii with two of the restriction endonucleases used (HinfI and TaqI), between A. simplex sensu stricto and A. simplex C with one endonuclease (HhaI), and between A. simplex C and Aniskis pegreffii with three endonucleases (HhaI, HinfI and TaqI), while no variation in patterns was detected among individuals within each species. The species A. physeteris, A. schupakovi, A. typica and A. ziphidarum were found to be different from each other and different from the three sibling species of the A. simplex complex by distinct fragments using 10-12 of the endonucleases tested. The polymorphisms obtained by restriction fragment length polymorphisms have provided a new set of genetic markers for the accurate identification of sibling species and morphospecies.

Genetic divergence and reproductive isolation between Anisakis brevispiculata and Anisakis physeteris (Nematoda: Anisakidae)s.

In order to assess the taxonomic status of Anisakis brevispiculata Dollfus, 1966 population samples of this taxon from central and south-eastern Atlantic ocean were compared at 22 enzymatic loci with samples belonging to Anisakis physeteris Baylis, 1923 from the Mediterranean sea and central-eastern Atlantic ocean. Very low interpopulational genetic divergence was observed both within A. brevispiculata (average D(Nei) = 0.008) and within A. physeteris (D(Nei) = 0.009) despite the geographic distance among the samples, indicating high levels of gene flow in both taxa. On the other hand, the average genetic distance between A. brevispiculata and A. physeteris was found to be D(Nei) = 0.80, a value generally observed between well differentiated congeneric species. The reproductive isolation between A. brevispiculata and A. physeteris is indicated by the following observations: (1) no F(1) hybrids or recombinant genotypes were until now observed; and (2) the two Anisakis species do not seem to share their definitive hosts. The main definitive host of A. brevispiculata is the pygmy sperm whale (Kogia breviceps), while for A. physeteris it is the sperm whale (Physeter catodon). Only adult males differ slightly in spicule length, while females and larval stages are not differentiated morphologically. Both A. brevispiculata and A.physeteris show a type II larva. The correct recognition of A. brevispiculata from A. physeteris and from other Anisakis species studied, in either sexes and at any life stage, is made easy by allozyme markers (e.g. Icdh, Gapdh, Sod-1, Np, Aat-2, Adk-2, fEst-2, PepB, PepC-2, Mpi). Diagnostic keys, which can be used for routine identification in the field of these Anisakis worms, based on genetic markers, are given.

Dose level effects of triazolam on sleep and response to a smoke detector alarm.

Thirty-six young adult, male subjects with sleep-onset insomnia were equally divided into placebo, 0.25 mg, and 0.5 mg triazolam groups to examine the effects of the hypnotic, with particular attention to dose level on efficacy, sleep stages, and awakening to a smoke detector alarm. On nights 1 and 4 of a five-consecutive-night protocol, a standard home smoke detector alarm was sounded during stage 2, 5 min after sleep onset, in slow wave sleep (SWS), and at the time of the early morning awakening. The alarm registered 78 dB SPL at the pillow. EEG arousal latency and reaction time to a button press were studied. Failure to awaken to three 1-min alarm presentations was scored as "no response." Both dose levels produced similar reductions in sleep latency, decreases in SWS, increases in stage 2, and increases in sleep efficiency. Both dose levels showed similar sedative effects to the smoke alarm. Fifty percent of triazolam subjects failed to awaken on night 1 during SWS, and EEG arousal and response latencies were significantly slowed. Some drug tolerance or sensitization to the alarm was seen by night 4. By morning, all subjects were easily awakened on both nights. The 0.25 mg dose is clearly an effective dose level for both sleep efficacy and sedative effects to outside noise, which in some instances could pose potential problems.

The Effect of Diet Quality on δ(13)C and δ(15)N in the Tissues of Locusts, Locusta migratoria L.

Abstract Locust nymphs were raised from hatching to adult locusts on either seedling wheat (C(3)) or maize (C(4)), to determine whether relative enrichments/depletions of (15)N and (13)C within body tissues are influenced by diet. The maize contained less hexose sugars and protein per gram than wheat. The isotopic spacing between the food and the whole insect was found to differ between the two diets. The lower quality maize diet showed an overall +5.1‰ enrichment in δ(15)N compared to + 2.8‰ for wheat, possibly due to increased fractionation due to protein recycling. The maize diet resulted in increased depletion in lipid and trehalose and depletion in chitin relative to diet. The results for both δ(15)N and δ(13)C suggest that substrate recycling was occurring on the low quality maize diet. Therefore diet quality determines the enrichment/depletion in δ(15)N and δ(13)C within organisms.

Physician goals: impact on hospital performance.

Controversy prevails concerning the relative superiority of for-profit versus not-for-profit hospitals. Presented here are three variations to each of two basic theoretical models that contrast performance of for-profit and not-for-profit hospitals.

Use of acetic orcein as a fast method to relax, fix, clear and stain cercariae for light microscopy.

Acetic orcein stain may be dropped onto the specimen before applying a cover slip. This single reagent reveals cercarial and metacercarial structures that would otherwise be made visible only by complicated and time consuming procedures.

Blue and fin whales observed on a seafloor array in the northeast pacific.

Calling blue and fin whales have been tracked using relative travel times and amplitudes from both direct and multipath arrivals to a seafloor array of seismometers. Calls of three fin whales swimming in the same general direction, but several kilometers apart, are believed to represent communication between the whales because of signature differences in call character, an alternating call pattern, and coordination of call and respiration times. Whale call tracks, call patterns, call character, and swimming speeds were examined during periods with and without the presence of noise. Noise sources included airguns, when the whales were subject to sound levels of up to 143 dB P-P (peak-to-peak) re: 1 microPa over the 10 to 60-Hz band, and transits of merchant ships, when the whales received continuous levels up to 106 dB rms re: 1 microPa over the 10 to 60-Hz band (115 dB P-P). Whale responses associated with these noises remain arguable.

Pituitary coma with continuing menstruation.

A case of pituitary coma with continuing menstruation is presented. This association is extremely rare, but a history of recent menstrual periods does not exclude advanced hypopituitarism from the differential diagnosis of severe hyponatraemia.

Potassium exchange in the human heart during atrial pacing and myocardial ischaemia.

Potassium homoeostasis in the heart was studied during atrial pacing in 20 patients undergoing diagnostic coronary angiography. The potassium concentrations in the coronary sinus and a systemic artery were recorded continuously by means of catheter tip potassium electrodes. Ten patients with coronary artery disease and a positive exercise test developed chest pain and ST segment depression on the electrocardiogram during atrial pacing. Potassium concentrations in the coronary sinus rose initially and increased further when myocardial ischaemia developed. Ten patients including five with normal coronary arteries remained symptom free during atrial pacing with no electrocardiographic changes. In these patients coronary sinus potassium concentration increased at the onset of pacing, but returned to near control values despite continued pacing. In both groups arterial potassium concentration remained constant. Immediately after the end of pacing there was an abrupt transient fall in potassium concentrations in the coronary sinus to below control values. These results indicate that in man, as in other species, an increase in heart rate causes the transient movement of potassium out of the cell into the extracellular space. The onset of myocardial ischaemia is associated with a further loss of potassium from the cell. The end of pacing or ischaemia is accompanied by a re-uptake of potassium by heart muscle.

High potassium concentration in a parenteral preparation of glyceryl trinitrate. Need for caution if given by intracoronary injection.

Glyceryl trinitrate (Tridil) was given by intracoronary injection to a patient who developed coronary artery spasm during angioplasty. Transient exacerbation of chest pain and electrocardiographic changes occurred. This formulation of the drug contains a high concentration of potassium ions and should not be given by this route.

Absence of a relationship between extracellular potassium accumulation and contractile failure in the ischemic or hypoxic rabbit heart.

Ischemia and hypoxia both cause a rapid loss of potassium from myocardial cells. We have investigated the relationship between the accumulation of potassium in the extracellular fluid and the early loss of contractility. Experiments were performed on the isolated rabbit heart perfused with physiological saline at 36 degrees C, paced at 3 Hz. Tension was recorded from the apex. Extracellular potassium concentration [( K+]o) was recorded with small ion-selective electrodes. After the onset of global ischemia, [K+]o rose within 15 sec and reached 9.5 +/- 1.1 mmoles/liter after 5 min. Developed tension (T) fell to 9 +/- 2% of control over the same period. During substrate-free hypoxia, T declined at a similar rate, and [K+]o rose slowly to 5.5 +/- 0.1 mmoles/liter after 5 min. The relationship between [K]o and T during normal perfusion and oxygenation was investigated by incrementally increasing the perfusate [K+]. T dropped to 78.6 +/- 4.5% of control at a [K+]o of 9 mmoles/liter. Comparison of the relationship between [K+]o and T during high-potassium perfusion, ischemia, and hypoxia shows that extracellular potassium accumulation per se makes almost no contribution to the decline of contractile function in ischemia or hypoxia. (Values are means +/- S.E., N = 5.)

Coronary sinus potassium concentration recorded during coronary angioplasty.

Coronary sinus potassium concentration was measured continuously in two patients undergoing angioplasty of a significant stenosis of the left anterior descending coronary artery. After each coronary occlusion there was a transient rise in coronary sinus plasma potassium concentration caused by washout of potassium which had accumulated in the extracellular fluid during the short period of ischaemia. There were no significant changes in the surface electrocardiogram and the patients experienced no chest pain. Changes in coronary sinus potassium concentration provide a sensitive and early indication of myocardial ischaemia in man.