bluuebunny/crossref_metadata_2025 huggingface dataset:
Sprawling Locomotion in the Lizard Sceloporus clarkii: Speed Modulation of Motor Patterns in a Walking Trot
Authors: Reilly Stephen M.
Published: April 2003

Previous kinematic analyses in Sceloporus clarkii have shown that increased speed during trotting is attained by retracting the femur relatively faster (decreasing retraction time relative to stride duration) while all other aspects of axial and limb movements occur simply faster (scaling with stride duration). Thus, most of the limb muscles must be modulated to move the joints absolutely faster, while muscles effecting femoral retraction must be modulated differently to retract the femur relatively faster to increase speed. This prediction was examined by analyzing motor patterns in several key leg muscles in the spiny lizard running over a threefold increase in speed during a trot. The prediction is borne out in the limb muscles where the limb adductor (flexor tibialis), knee extender (femorotibialis), and plantar flexor of the ankle (gastrocnemius) have similar patterns of motor modulation that are different from that of the femoral retractor (caudofemoralis). To modulate a muscle to move simply faster (scaled with speed) the offset of the motor pattern is moved relatively earlier to decrease burst duration, while the intensity of electromyographical activation is ramped up. Increasing the relative speed of action is done by activating the muscle earlier, increasing the duration of the burst, and increasing the relative level of activation. Comparisons to other studies illustrate that the confounding effects that stance and swing duration have on stride duration with speed have important consequences for functional interpretations and that scaling locomotory data to stance duration is a more appropriate and useful convention because it relates information directly to the duty cycle when the propulsive effects of motor modulation are transmitted to the substrate. The iliocostalis in Sceloporus clarkii has a pattern of activity indicating that it functions to rotate the pelvis to aid the contralateral duty cycle. This is strikingly different from the function of the iliocostalis in the monitor lizard. Differences in axial function and differences among lizards in postures of the foot and crus during locomotion indicate that there are different ways that lizards run and that the functional and anatomical diversity of modes of locomotion in lizards is greater than is recognized at present.
Coexistence of FMRFAMIDE-Like and LHRH-Like Immunoreactivity in the Terminal Nerve and Forebrain of the Big Brown Bat, Eptesicus fuscus
Authors: Oelschläger H.A. , Helpert C. , Northcutt R.G.
Published: April 2003

The coexistence of molluscan cardioexcitatory neuropeptide (FMRFAMIDE) and luteinizing hormone-releasing hormone (LHRH) was studied in the nervous system of the big brown bat, Eptesicus fuscus, with immunocytochemistry. Within mammals, this is the first report of the coexistence of these neuropeptides in the terminal nerve. In juvenile and adult bats, both neuropeptides are distributed identically throughout the terminal nerve (tn), and they coexist in many parts of the prosencephalon from the olfactory bulb as far caudally as the interpeduncular nucleus. Peripherally, on the basal surface of the forebrain, fibers and a few perikarya, which may belong to the tn, form a loose plexus. Within the brain wall, regions of maximal immunoreactivity (ir) are the habenula, medial preoptic area, arcuate nucleus, and the infundibulum. Whereas in most areas of the prosencephalon (e.g., stria terminalis and bed nuclei, amygdaloid complex) fibers show stronger immunoreactivity to FMRFAMIDE, labeling of fibers in the habenula and infundibulum is largely identical for both neuropeptides. The arcuate nucleus contains a large number of perikarya and is the major source of both FMRFAMIDE- and LHRH-ir within the forebrain. A number of fibers run along the ependyma of the ventricular system and seem to terminate here; this is particularly evident in the median eminence and infundibular stalk. In the big brown bat, there seems to exist a continuum of FMRFAMIDE- and LHRH-ir throughout the tn and those structures of the forebrain that are known to be engaged in the control of mating behavior, reproduction, and rhythmicity. Concerning the hypothalamo-hypophyseal-gonadal axis, the arcuate nucleus may serve as a central hub between the olfactory/terminal input and superior areas including the limbic system. In contrast to LHRH immunoreactivity, FMRFAMIDE-like ir extends throughout the brainstem and cervical spinal cord. This system may also be involved in the processing and modulation of autonomic input via the parabrachial and solitary nuclei, the rhombencephalic central gray, and its projection into the hypothalamus (paraventricular nucleus), thus facilitating feed-back of gonadotropic influences of the terminal nerve and prosencephalon.
Behavior of Juvenile Lizards (Iguana iguana) in a Conflict between Temperature Regulation and Palatable Food
Authors: Balasko Marta , Cabanac Michel
Published: April 2003

Juvenile green iguanas were placed in a situation of conflict between two motivations: a thermoregulatory drive and the attraction of a palatable bait. To be able to reach the bait (lettuce), they had to leave a warm refuge, provided with standard food, and venture into a cold environment. In experiment 1 the time interval between sessions with bait, ranging from 1 to 8 days, had no effect on the duration of stay on the bait. This result shows that the lettuce was not a necessary food, deprivation of which would have had to be compensated for. In experiment 2 as the ambient temperature at the bait decreased the lizards spent less time feeding on lettuce, and they visited the bait less frequently. This result shows that the lizards traded off the palatability of the bait with the disadvantage of the cold. These findings support the hypothesis that a common currency makes it possible for lizards to compare two sensory modalities.
Retinal Structure and Visual Acuity in a Polyprotodont Marsupial, the Fat-Tailed Dunnart (Sminthopsis crassicaudata)
Authors: Arrese C. , Dunlop S.A. , Harman A.M. , Braekevelt C.R. , Ross W.M. , Shand J. , Beazley L.D.
Published: April 2003

The visual system of the fat-tailed dunnart (Sminthopsis crassicaudata), a small polyprotodont marsupial, has been examined both anatomically and behaviourally. The ganglion cell layer was examined in cresyl-violet stained wholemounts and found to contain a mean of 81,400 ganglion cells (SD ± 3,360); the identification of ganglion cells was supported by a correspondence to optic axon counts. Ganglion cells were distributed as a mid-temporally situated area centralis, embedded in a pronounced visual streak. Localised implants of horseradish peroxidase into retinal wholemounts revealed both A-type and B-type horizontal cells. Sections of the outer retina showed it to be rod-dominated, with a rod-to-cone ratio of 40:1 at the area centralis; cones were found to contain oil droplets but double cones were not a prominent feature. The retinal pigment epithelium consisted of squamous cells. Visual acuity, estimated from counts of peak ganglion cell density (8,300/mm2, SD ± 1,180) and measurements of posterior nodal distance (2.9 mm), was found to be 2.30 cycles per degree. The value was close to that of 2.36 cycles per degree estimated by behavioural tests using a Mitchell jumping stand; values were similar at low, intermediate and high light levels. Our findings are discussed in relation to the lifestyle of the dunnart.
CSF Monoamines, Age and Impulsivity in Wild Grivet Monkeys (Cercopithecus aethiops aethiops)
Authors: Fairbanks Lynn A. , Fontenot M. Babette , Phillips-Conroy Jane E. , Jolly Clifford J. , Kaplan Jay R. , Mann J. John
Published: April 2003

Brain monoaminergic activity has been associated with behaviors, such as impulsive risk-taking, that tend to peak during adolescence in humans and nonhuman primates. This study was designed to assess natural variation in monoamine neurotransmitter metabolism in relation to age and behavioral impulsivity in grivet monkeys (Cercopithecus aethiops aethiops) living in their native habitat and subject to natural ecological pressures. Cisternal cerebrospinal fluid, collected from 22 animals living in the Awash National Park, Ethiopia, was assayed for the major metabolites of serotonin (5-hydroxyindoleacetic acid, 5-HIAA), dopamine (homovanillic acid, HVA) and norepinephrine (3-methoxy-4-hydroxyphenylglycol, MHPG). Concentrations of HVA declined significantly from one year of age to older adulthood. Further, a significant curvilinear relationship was identified between age and the 5-HIAA/HVA ratio, with the trough coinciding with the period of adolescence. Finally, behavioral impulsivity, as measured by re-entering baited traps a second time after the animal had already been captured and sampled for CSF, was related to lower levels of MHPG. The results suggest that normal variation in central monoaminergic activity may have functional consequences in wild populations.
Encephalization, Adaptation and Evolution of Chiroptera: A Statistical Analysis with Further Evidence for Bat Monophyly
Authors: Lapointe François-Joseph , Baron Georg , Legendre Pierre
Published: April 2003

As part of a large-scale study on brain morphometrics and adaptations in mammals, we addressed the problem of chiropteran evolution. A specific statistical framework was designed to test which of two competing hypotheses (bat monophyly vs. diphyly) is more strongly supported by quantitative brain data. Our analyses, based on 120 species, revealed that megabats and microbats were more closely related to each other than to primates, and illustrated the convergent adaptations of the brain of bats to similar trophic (i.e. feeding related) niches. Ecologically-corrected characters were then used to derive a new phylogeny which also supports the chiropteran clade. The monophyletic origin of bats is the preferred hypothesis to explain brain quantitative evolution in chiropterans and primates.
Sonic Motor Nucleus and Its Connections with Octaval and Lateral Line Nuclei of the Medulla in a Rockfish, Sebastiscus marmoratus
Authors: Yoshimoto Masami , Kikuchi Kumiko , Yamamoto Naoyuki , Somiya Hiroaki , Ito Hironobu
Published: April 2003

The sonic motor nucleus and its fiber connections were examined in a rockfish, Sebastiscus marmoratus by means of tracer methods using horseradish peroxidase (HRP), biocytin, and carbocyanine dye (DiI). Sebastiscus has a swimbladder and a pair of extrinsic sonic/drumming muscles. The sonic muscle is ipsilaterally innervated by the occipital nerve which is composed of two ventral roots arising from the sonic motor nucleus. The sonic motor neurons are distributed in the most ventral part of the ventral column from the caudal medulla to the rostral spinal cord, and form a ventrally located columnar nucleus. Each neuron in this nucleus possesses a long thick dendrite and several short dendrites. The long dendrite extends dorsolaterally and branches in the lateral funiculus, whereas the short dendrites branch around their cell bodies. After biocytin injections into the sonic motor nucleus, two groups of premotor neurons were retrogradely labeled bilaterally, one in the dorsomedial portion of the descending octaval nucleus (DO) and the other in the medial zone of the reticular formation (RF) in the medulla. The DO premotor neurons were multipolar with several dendrites branching near the cell bodies, and the RF premotor neurons were bipolar. One of the two dendrites of the RF premotor neurons extends laterally into the ventral portion of the DO, and the other dendrite extends into the ventromedial area in the medulla. In the ventromedial dendritic field of the RF premotor neurons, descending fibers arising from the optic tectum (TO) and torus semicircularis (TS) traverse in the tractus tectobulbaris and terminate bilaterally. After DiI insertion into the ventromedial dendritic field, retrogradely labeled neurons were found bilaterally in the TS and TO. The majority of tectal neurons were located in the stratum griseum centrale. These neurons had two short basal dendrites branching in the cell layer and a long apical dendrite extending to the stratum fibrosum et griseum superficiale and stratum opticum. The toral neurons were bipolar and were distributed throughout the TS. Furthermore, biocytin injections into the medial nucleus of the lateral line system revealed that the nucleus projects bilaterally to the RF premotor neurons. These results show that premotor neurons for the sonic motor nucleus are located in the dorsomedial portion of the DO and the medial zone of the RF in the medulla. It is suggested that the sonic motor nucleus receives auditory input via the DO premotor neurons and input from RF premotor neurons which receive lateral line input via the medial nucleus, vestibular input through the lateral dendrite extending into the ventral portion of the DO, and information from the TO and TS via the tractus tectobulbaris.
Fiber Connections of the Corpus Mamillare in a Percomorph Teleost, Tilapia Oreochromis niloticus
Authors: Sawai Nobuhiko , Yamamoto Naoyuki , Yoshimoto Masami , Ito Hironobu
Published: April 2003

The hypothalamus and perhaps its function appear to be similar among vertebrates. Thus, studying the teleostean hypothalamus could be a good model for understanding common neural circuits and mechanisms retained through the vertebrates. However, connections of the inferior lobe, which is considered the hypothalamus in teleosts, is poorly known. The corpus mamillare (CM) is a nucleus of the inferior lobe named after the mammalian mamillary body based on similarities in external morphology. Afferent connections of the CM have been reported only in cypriniform teleosts. These include projections from the nucleus pretectalis superficialis pars magnocellularis, a nucleus lacking in percomorph teleosts, and projections from the secondary gustatory nucleus. Efferent connections of the CM have not been reported in teleosts. In the present study, the CM and its subdivisions and the connections of these subnuclei were identified in isolated and maintained brains of tilapia Oreochromis niloticus by local DiI and biocytin injection. Afferent connections confirmed by reciprocal injections were from the nucleus diffusus lobi inferioris (NDLI) and the nucleus diffusus tori lateralis (NDTL). Efferent connections of each CM subnuclei were also reciprocally confirmed. These connections were to the area dorsalis pars medialis of the telencephalon, the nucleus ventromedialis (NVM) of the thalamus, the tectum opticum (TO), and the nucleus posterioris periventricularis. Because the NDLI is known to receive gustatory information in tilapia, the CM could relay gustatory inputs to multisensory areas, the TO and NVM, for which there are no current reports regarding gustatory inputs.
Temperature Dependence of Electrocommunication Signals and Their Underlying Neural Rhythms in the Weakly Electric Fish, Apteronotus leptorhynchus
Authors: Dunlap K.D. , Smith G.T. , Yekta A.
Published: April 2003

Weakly electric fish emit an electric communication signal that is controlled by a highly specialized neural circuit. In Apteronotus, the continuous electric organ discharge (EOD) is generated by electrotonically coupled neurons in the hindbrain pacemaker nucleus, and transient EOD modulations involve chemical synapses from descending midbrain and thalamic prepacemaker nuclei. We characterized the effects of temperature change (18–32°C) on both the continuous EOD and EOD modulations, chirps, in A. leptorhynchus. EOD frequency was linearly related to temperature (Q10=1.62). By contrast, the temperature dependence of EOD amplitude changed with temperature. Amplitude increased steeply with temperature below 25°C (Q10=2.0), but increased only gradually above 25°C (Q10=1.15). EOD waveform, and consequently harmonic content, was also affected by temperature. The amplitude of the second harmonic was relatively high at both low and high temperature and relatively low at intermediate temperatures. The amplitude of the third harmonic increased monotonically with temperature. Thus, temperature has qualitative as well as quantitative effects on the production of the EOD. Chirp rate (Q10=3.2) had a higher temperature dependence than that of the continuous EOD, which likely reflects its reliance on chemical rather than electrotonic synapses. In vitro pacemaker firing frequency had a similar, but slightly higher Q10 (1.82) than that of the EOD frequency.
Variability in the Location of the Retinal Ganglion Cell Area Centralis Is Correlated with Ontogenetic Changes in Feeding Behavior in the Black Bream, Acanthopagrus butcheri (Sparidae, Teleostei)
Authors: Shand Julia , Chin Stephanie M. , Harman Alison M. , Moore Stephen , Collin Shaun P.
Published: April 2003

The development of neural cell topography in the retinal ganglion cell layer was examined in a teleost, the black bream (Acanthopagrus butcheri). From Nissl-stained wholemounts, it was established that fish between 10 and 15 mm standard body length (SL) possess high cell densities throughout the dorso-temporal retinal quadrant, with peak cell densities located in temporal regions of the retina. However, in fish between 15 and 80 mm SL, a wide variation in the position of the peak cell density is revealed with the locations of the areae centrales (AC) ranging from exclusively temporal to periphero-dorsal retina. Fish larger than 80 mm SL always possess an AC located in the dorsal region of the dorso-temporal retinal quadrant. The topography of ganglion cells within the ganglion cell layer was determined by comparing the numbers of ganglion cells retrogradely-labeled from the optic nerve with the total population of Nissl-stained neurons (ganglion plus displaced amacrine cells) in a range of different-sized individuals. Ganglion cell topography was the same as that recorded for all Nissl-stained neurons. The feeding behavior of juveniles from metamorphosis to 80 mm SL was observed, where fish were given the choice of feeding on live food in mid-water (until 15 mm SL) or obtaining pellets from the surface or the bottom. A range of feeding patterns was recorded, with the smallest fish taking food from mid-water but individuals between 15 and 80 mm SL taking food either from the surface or the bottom or both. A correlation between the preferred mode of feeding and the position of the AC was found, such that those individuals feeding in mid-water or at the surface possess a temporal or intermediate (dorso- temporal) AC, whereas those predominantly feeding from the bottom possess a dorsal AC.
Taking the Measure of Diversity: Comparative Alternatives to the Model-Animal Paradigm in Cortical Neuroscience
Authors: Preuss Todd M.
Published: April 2003

Cortical neuroscience is founded on studies of a very few model organisms, mainly rats, cats, and macaque monkeys. The concentration of effort on such a few species would be defensible if cortical organization were basically uniform across mammals, as is commonly believed. Although there is little reason to doubt that some features of cortical organization are indeed widespread among mammals, phyletic variation in cortical organization is far more extensive than has generally been appreciated or acknowledged. Rats, for example, differ from other mammals in the genetics and chemistry of their cortical neurons, in connectivity and areal organization, and in the functions of specific cortical regions. Likewise, macaque monkeys, although widely used as models of the human visual system, lack a number of features found in human visual cortex. Given the variability of cortical organization, how should neuroscientists approach the study of nonhuman species, and what can we reasonably expect to learn from them? First, by examining a wider range of species than are currently employed, and by using modern techniques of phyletic analysis, neuroscientists can more rigorously identify those features of cortical organization that are, in fact, widely shared among mammals or among particular mammalian subgroups. Second, by taking account of variations, neuroscientists can abstract more reliable and general principles of structure-function relationships in the nervous system. Finally, freed from the doctrine of basic uniformity, neuroscientists can pursue the study of human cortical specializations, and so advance our understanding of what distinguishes humans as a biological species.
Eye Design and Color Signaling in a Stomatopod Crustacean Gonodactylus smithii
Authors: Chiao Chuan-Chin , Cronin Thomas W. , Marshall N. Justin
Published: April 2003

Many species of stomatopod crustaceans have multiple spectral classes of photoreceptors in their retinas. Behavioral evidence also indicates that stomatopods are capable of discriminating objects by their spectral differences alone. Most animals use only two to four different types of photoreceptors in their color vision systems, typically with broad sensitivity functions, but the stomatopods apparently include eight or more narrowband photoreceptor classes for color recognition. It is also known that stomatopods use several colored body regions in social interactions. To examine why stomatopods may be so ‘concerned’ with color, we measured the absorption spectra of visual pigments and intrarhabdomal filters, and the reflectance spectra from different parts of the bodies of several individuals of the gonodactyloid stomatopod species, Gonodactylus smithii. We then applied a model of multiple dichromatic channels for color encoding to examine whether the finely tuned color vision was specifically co-evolved with their complex color signals. Although the eye design of stomatopods seems suitable for detecting color signals of their own, the detection of color signals from other animals, such as reef fishes, can be enhanced as well. Color vision in G. smithii is therefore not exclusively adapted to detect its own color signals, but the spectral tuning of some photoreceptors (e.g. midband Rows 2 and 3) enhances the contrast of certain color signals to a large enough degree to make co-evolution between color vision and these rather specific color signals likely.
Separate Origins of All Three Major Coronary Arteries from the Right Sinus of Valsalva:A Rare Coronary Artery Anoma ly
Authors: Rahmatullah Syed I. , Khan Ijaz A. , Nair Vinod M. , Kannan Tarif , Vasavada Balendu C. , Sacchi Terrence J.
Published: April 2003

The origination of all three major coronary arteries from three separate ostia in the right sinus of Valsalva is an exceedingly rare coronary anomaly. Few radiographic and clinical details of this anomaly are available in the literature. We describe this anomaly in a patient with acute myocardial infarction who remained asymptomatic until the 8th decade of her life. Atherosclerotic narrowing of the normally originating right coronary artery caused the acute myocardial infarction. Anomalous left anterior descending and left circumflex arteries were free of any significant obstruction.
Antimicrobial Susceptibility Testing of Dermatophytes – Comparison of the Agar Macrodilution and Broth Microdilution Tests
Authors: Niewerth M. , Splanemann V. , Korting H.C. , Ring J. , Abeck D.
Published: April 2003

Fifty dermatophyte strains, recently obtained from clinical material, belonging to 4 different species were examined for their susceptibility to 5 systemic or topical antimycotic agents using both an agar macrodilution and a broth microdilution test. Antimycotics compared were griseofulvin, itraconazole, sertaconazole, terbinafine and ciclopiroxolamine. A comparison of the minimum inhibitory concentrations (MIC) clearly showed differences between the two test methods applied. For all 5 antimycotics, MIC data were three- to seventyfold lower in the microdilution test system. These differences, depending on the test method, have to be taken into account when comparing MIC data in the literature or when relating the in vitro data to the tissue concentrations determined in vivo.
Preventive Effect of Dapsone on Renal Scarring following Mannose-Sensitive Piliated Bacterial Infection
Authors: Mochida Osamu , Matsumoto Tetsuro , Mizunoe Yoshimitsu , Sakumoto Misao , Abe Junji , Kumazawa Joichi
Published: April 2003

Renal scarring has been thought to occur in the later stages of chronic pyelonephritis. We previously reported that mannose-sensitive (MS) piliated bacteria promoted renal scarring, which was prevented by antioxidants. The preventive effect of diaphenylsulfone (dapsone), which has a scavenging activity on active oxygen species, on renal scarring was examined. Female Sprague-Dawley rats were inoculated with clinical isolates of Serratia marcescens which had both MS and mannose-resistant pili or with recombinant strains which had MS pili on their surface; they were then administered 20 mg/kg of dapsone or not. Dapsone significantly suppressed scarring following infection of the kidney. The bacterial counts in the kidneys were not different in dapsone-treated and nontreated rats. We conclude that dapsone is effective in preventing renal scarring, and it is suggested that the clinical use of this drug may prevent renal scar formation following pyelonephritis.
Detection of Fluoroquinolones in Urinary Specimens from Patients Undergoing Anti-Tuberculous Therapy
Authors: Chan C.Y. , Tsang D.S.C. , Chan T.-L. , Yew W.W. , Cheung S.W. , Cheng A.F.B.
Published: April 2003

A paper strip impregnated with ferric chloride has been developed for visual detection of fluoroquinolones in urine based on a change of colour due to the chelation of the transition metal ion to the β-oxo acid array in the 4-oxo-1,4-dihydropyridine-3-carboxylic acid moiety of the fluoroquinolone molecule. In urine specimens, the detection limit of the strip was 100 mg/l for pefloxacin, 200 mg/l for ciprofloxacin, fleroxacin, levofloxacin, norfloxacin, ofloxacin and sparfloxacin, and 300 mg/l for trovafloxacin. In 193 urine specimens taken from 138 patients on ofloxacin therapy and 55 controls preliminary evaluation of the strip showed that all the 55 specimens from control patients were negative, while 112 out of the 138 ofloxacin-treated patients were positive. Quantitative analysis by high-performance liquid chromatography of the 26 strip-test-negative specimens taken from patients with ofloxacin treatment indicated that these urinary specimens contained less than 200 mg/l of the antimicrobial, mostly because of poor renal function and in some occasions, non-compliance. This strip method would provide a convenient way of monitoring drug compliance in patients who receive fluoroquinolone therapy for tuberculosis.
Evaluation of Different Antibiotics in Inhibiting Colonization of Vibrio cholerae O1 and O139 in the Rabbit Intestine
Authors: Chakrabarti M.K. , Bhattacharya M.K. , Bhattacharya J. , Bhattacharya S.K. , Mahalanabis D.
Published: April 2003

The effects of furazolidone, erythromycin and azithromycin in inhibiting colonisation of Vibrio cholerae O1 and O139 in the rabbit intestine were tested. Both V. cholerae O1 and O139 highly colonised the gut in control rabbits. The colonisation of furazolidone-resistant strains in the rabbit intestine was prevented effectively by both erythromycin and azithromycin. In furazolidone-sensitive strains, the efficacies of erythromycin and azithromycin were very much comparable to furazolidone. These results suggested that azithromycin may be subjected to clinical trial in comparison to furazolidone and erythromycin for the treatment of cholera due to O1 and O139 infection in children.
The in vitro Effect of Macrolides on the Interaction of Human Polymorphonuclear Leukocytes with Pseudomonas aeruginosa in Biofilm
Authors: Takeoka Kaori , Ichimiya Tomoku , Yamasaki Tohru , Nasu Masaru
Published: April 2003

The in vitro effect of macrolides at concentrations below the minimum inhibitory concentration (sub-MIC) on the interaction between Pseudomonas aeruginosa biofilm and human polymorphonuclear leukocytes (PMNs) was investigated by using a chemiluminescence assay. The PMN response to either mucoid or nonmucoid P. aeruginosa biofilm was strongly reduced compared with the response to planktonic bacteria (p < 0.01, p < 0.001, respectively). When biofilms were treated with erythromycin, clarithromycin, roxithromycin and azithromycin prior to incubation with PMNs, the chemiluminescence response was markedly enhanced as compared to untreated controls, and a dose-dependent effect was noted over the range of sub-MIC concentrations studied. In general, macrolides appeared to be slightly more active against mucoid biofilm. Azithromycin was shown to be the most active macrolide against P. aeruginosa biofilms. However, the treatment with sub-MICs of rokitamycin did not have any effect. On the other hand, treatment of planktonic bacteria with macrolides before being exposed to the PMNs did not affect the chemiluminescence response as compared to untreated controls. These findings suggest that macrolides inhibiting the biofilm formation of P. aeruginosa may facilitate the phagocytosis of bacteria by PMNs.
Pharmacodynamics of Intermittent- and Continuous-Infusion Cefepime Alone and in Combination with Once-Daily Tobramycin against Pseudomonas aeruginosa in an in vitro Infection Model
Authors: Tessier Pamela R. , Nicolau David P. , Onyeji Cyprian O. , Nightingale Charles H.
Published: April 2003

Cefepime, a fourth-generation cephalosporin, is currently one of the primary agents used in combination with an aminoglycoside when treating Pseudomonas aeruginosa infections. The bactericidal activity of cefepime administered as intermittent doses (IT) or continuous infusion (CI) both alone and in combination with once-daily tobramycin (ODT) against two clinical strains of P. aeruginosa was compared using an in vitro infection model. Cefepime concentrations simulated human pharmacokinetics after a 1-gram Q12 regimen, or a 1-gram loading dose followed by a 2-gram Q24 CI regimen; the ODT regimen mimicked peak concentrations of ≥10 × MIC. All regimen simulations were run in duplicate over 48 h and a growth control (no antimicrobials added) was run concurrently. Strains tested, PSA5 and PSA10, had MICs of 2 and 8 μg/ml to cefepime, respectively; both MICs to tobramycin were 1.0 μg/ml. CI regimens resulted in concentrations approximately 6× and 2× the MIC for PSA5 and PSA10, respectively. The change in log10 colony-forming units (CFU) per milliliter over time for both P. aeruginosa isolates was compared to initial inocula for all treatment regimens. Initial bolus doses of both IT and CI regimens resulted in a similar decrease in the log10 CFU/ml of both organisms over the first 12 h of the study. After subsequent doses, however, both IT regimens showed greatly diminished bactericidal activity, while both CI regimens were persistently bactericidal without the observation of significant regrowth. As a result, a statistical difference in log10 CFU/ml between both IT and CI regimens with and without ODT was realized at 24, 36 and 48 h for each isolate. Unlike IT dosing, CI cefepime alone or in combination with ODT optimizes bactericidal activity by maximizing the percent of the dosing interval that concentrations remained above the MIC resulting in undiminished bacterial inhibition when compared to IT regimens. These data further suggest that CI is the most efficient method of administration of β-lactam antibiotics.
Prediction of Flucytosine-Induced Thrombocytopenia Using Creatinine Clearance
Authors: Vermes Andras , Guchelaar Henk-Jan , Dankert Jacob
Published: April 2003

Aims: To evaluate and investigate the efficacy and accuracy of an earlier derived relationship between thrombocyte nadir and mean creatinine clearance in order to make it possible to predict flucytosine (5-FC)-related thrombocytopenia. Methods: The earlier derived relationship between thrombocyte nadir and mean creatinine clearance is validated using a patient population of 35 intensive care unit (ICU) patients. Patients have to meet the inclusion criteria as defined in the initial study (i.e., developing thrombocytopenia during 5-FC treatment or remaining within the normal thrombocyte range; individual pharmacokinetic parameters within certain limits; a minimum of three measured 5-FC serum levels). Results: Of a total of 35 patients, 11 are eligible since they meet the inclusion criteria as defined in the initial study. A significant relationship between the observed and predicted thrombocyte nadir values can be derived: Ypred = 0.608·Xobs + 24.330 (r = 0.615; tobs = 2.337; t at p < 0.05 and 9 degrees of freedom = 2.262). The predicted value of the thrombocyte nadir corresponds with a mean prediction error (bias) of –18.3 (95% CI –45.9; 9.4) and a root mean squared prediction error (precision) of 48.3 (95% CI 23.9–63.9). Conclusion: The earlier derived relationship between thrombocyte nadir and mean creatinine clearance is accurate and precise. However, due to the strict inclusion criteria used to derive and validate this relationship, it cannot be applied to all 5-FC-treated patients.
Impact of Irritable Bowel Syndrome on Quality of Life and Resource Use in the United States and United Kingdom
Authors: Hahn Beth A. , Yan Songkai , Strassels Scott
Published: April 2003

Background: Although irritable bowel syndrome (IBS) is not a life-threatening condition, it can have a serious impact on a patient’s daily activities and quality of life. This effect on quality of life has not been compared previously across different cultures. Methods: We compared measures of health-related quality of life and health care resource utilization using a cross-sectional point-in-time postal survey of a random sample of 500 members of the International Foundation for Functional Gastrointestinal Disorders in the US and 500 members of the IBS Network support group in the UK. The analysis was limited to persons who reported that a physician had told them they had IBS. A general health status questionnaire, the SF-36, and a disease-specific questionnaire, the Irritable Bowel Syndrome Quality of Life questionnaire (IBSQOL), were self-administered as part of the survey to measure health-related quality of life. Results on the SF-36 were compared with published normative data for adults in the US and UK with and without chronic diseases. Results: The UK group (n = 343) reported significantly poorer quality of life on the SF-36 and on four parameters of the IBSQOL than did the US group (n = 287). The general health status of persons with IBS in either country was much poorer compared with that of general populations in the respective countries. Health care resource utilization (i.e. emergency room, doctor and hospital outpatient visits) of persons with IBS was similar in the two countries, as was the direct effect of IBS on employment. Nearly one third of those surveyed missed at least 1 day of work due to IBS in the previous 4 weeks, and a greater percentage cut back in their work or activites due to IBS. Taken together, average time lost or cut back amounted to nearly 5 days or 1 work-week. Conclusion: IBS has a significant impact on quality of life and resource use in both the US and UK. The effect on quality of life, however, appears to be greater in the UK than in the US.
Follow-Up in Carriers of the ‘MELAS’ Mutation without Strokes
Authors: Damian Maxwell Simon , Hertel Andreas , Seibel Peter , Reichmann Heinz , Bachmann Georg , Schachenmayr Walter , Hoer Gustav , Dorndorf Wolfgang
Published: April 2003

Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases, but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the future.
[123I]β-CIT SPECT Visualizes Dopamine Transporter Loss in de novo Parkinsonian Patients
Authors: Müller T. , Farahati J. , Kuhn W. , Eising E.G. , Przuntek H. , Reiners C. , Coenen H.H.
Published: April 2003

Parkinson’s disease (PD) is characterized by degeneration of dopaminergic neurons in the basal ganglia, which may be visualized by single photon emission computed tomography (SPECT) in combination with the cocaine analog methyl-3-β-(4-β[123I]iodophenyl)tropane-2β-carboxylate ([123I]β-CIT). The aim of our study was to correlate findings of SPECT with clinical data of 34 previously untreated, idiopathic parkinsonian patients [age: 59.58±10.03 (mean±SD) years; Hoehn and Yahr Scale (HYS) mean range: 1.97±0.83, ranges I–III; Unified PD Rating Scale 3.0 (UPDRS, 30.64±18.68) and 15 healthy controls (age 47.93±10.47 years). SPECT scans were performed with a single-head γ-camera 24 h after intravenous injection of [123I]β-CIT. Comparison of the striatum/cerebellum (S/C) ratio of [123I]β-CIT uptake of controls and parkinsonian subjects, subdivided according to their HYS range, was significant. No influence of age or sex was observed. Significant correlations were found between scores of the HYS, UPDRS parts I–III, part II, part III, and the S/C ratio of [123I]β-CIT uptake. Moreover, SPECT with the radiotracer [123I]β-CIT revealed side-to-side differences in parkinsonian patients and significant associations to contralateral clinical extrapyramidal symptomatology. Our data show that SPECT with [123I]β-CIT is a valuable tool for estimating disease severity in PD.
Herpes zoster oticus: Correlations between Clinical and MRI Findings
Authors: Berrettini Stefano , Bianchi Maria Cristina , Segnini Giovanni , Sellari-Franceschini Stefano , Bruschini Paolo , Montanaro Domenico
Published: April 2003

Many gadolinium-enhanced magnetic resonance imaging (MRI) studies focusing on the anatomy and pathology of the 7th cranial nerve have already been published. However, only scattered cases of herpes zoster oticus (HZO) have been described and only the MRI appearance of the soft temporal bone structures has been reported. Enhanced MRI was performed in 4 patients with HZO observed at the Department of Otorhinolaryngology of the University of Pisa. A good correlation was found between the clinical data and MRI findings in both the acute and chronic stages of the disease. The 2 cases with complete facial palsy presented prominent and diffuse enhancement of the 7th and 8th cranial nerves on postcontrast MRI, while the patient with grade III facial palsy showed more limited nerve enhancement. The patient with grade II facial palsy presented no MRI abnormalities. In our series, enhancement limited to the geniculate ganglion and to the labyrinthine segment of the facial nerve indicates a good prognosis while a widespread enhancement correlates with a poor prognosis. In conclusion, MRI with contrast may be useful during the acute stage of HZO because it can confirm the diagnosis and can provide prognostic information on the facial function.
Cerebrospinal Fluid Levels of Amyloid Precursor Protein and Amyloid β-Peptide in Alzheimer’s Disease and Major Depression – Inverse Correlation with Dementia Severity
Authors: Hock Christoph , Golombowski Sidonie , Müller-Spahn Franz , Naser Werner , Beyreuther Konrad , Mönning Ursula , Schenk Dale , Vigo-Pelfrey Carmen , Bush Ashley M. , Moir Robert , Tanzi Rudolph E. , Growdon John H. , Nitsch Roger M.
Published: April 2003

Alzheimer’s disease (AD) is the most common neurodegenerative disorder characterized by progressive dementia that ultimately leads to death. Histopathological hallmarks of AD include brain amyloid deposits and neurofibrillary tangles. Major depression is a frequent diagnosis in every gerontopsychiatric clinic that sees patients with both cognitive and affective disorders. Many depressed patients, in fact, are clinically characterized by cognitive impairments. Thus, an assay that excludes – or confirms – probable AD in cognitively impaired patients is desirable. Such assays may use protein markers that are derived from such histopathologically relevant molecules as the amyloid precursor protein (APP) and its derivatives including the amyloid β-peptides (Aβ). To evaluate the differential diagnostic properties of cerebrospinal fluid (CSF) Aβ and secreted soluble ectodomain (APPs), we quantitated CSF levels of these measures in AD patients and compared them to age-matched control patients with major depression. CSF levels of APPs and Aβ were similar in patients with AD or major depression, and the apolipoprotein E genotype had no influence on CSF levels of Aβ in AD patients. Measurement of Aβ peptide using a novel zinc/copper capture ELISA that detects aggregated Aβ peptides as well demonstrated similar levels in AD and major depression. In AD patients, CSF levels of total Aβ (Aβ1–40 plus Aβ1–42) were inversely correlated with a functional measure of dementia severity (NOSGER), suggesting that CSF levels of Aβ decrease with advancing severity of AD. Thus, CSF levels of Aβ are not useful for the differentiation of AD from major depression. However, CSF levels of Aβ reflect the severity of dementia and may be useful as biological markers of the stage of the disease.
Apolipoprotein E Polymorphism in Alzheimer’s Disease: A Comparative Study of Two Research Populations from Spain and the United States
Authors: Lopez Oscar L. , Lopez-Pousa Secundino , Kamboh M. Ilyas , Adroer Rosa , Oliva Rafael , Lozano-Gallego Manuela , Becker James T. , DeKosky Steven T.
Published: April 2003

We examined the distribution of the apolipoprotein E (APOE) polymorphism in two Caucasian populations of Alzheimer’s disease (AD) patients referred to dementia clinics; one in Gerona, Spain (66 AD patients, 49 controls), and the other in Pittsburgh, Pa., USA (209 AD patients, 58 controls). The presence of the APOE*4 allele was a significant risk for developing AD in both cohorts: Gerona (odds ratio = 2.34, CI: 1.03–5.55) and Pittsburgh (odds ratio = 3.64, CI: 1.78–7.69). The proportion of AD with the APOE*4 allele was greater in the Pittsburgh cohort than in the Gerona cohort (p = 0.02). However, no statistical difference was noted between the two populations in nondemented controls (p = 0.41). These data emphasize the importance of geographical and ethnic variations in the study of APOE genotypes.
Increased Plasma Concentration of Atrial Natriuretic Hormone in Myotonic Dystrophy
Authors: Parlapiano C. , Antonini G. , Vichi R. , Fragola P.V. , Campana E. , Rota C. , Borgia M.C. , Tonnarini G. , Negri M.
Published: April 2003

Atrial natriuretic hormone (ANH) concentrations were measured in 16 patients affected with myotonic dystrophy (MyD) undergoing 24-hour Holter ECG and in 15 age-matched normal subjects. Although the MyD patients did not show overt left ventricular function impairment, their plasma ANH levels were found to be higher (183.76 ± 113.25 pg/ml) compared to those of the control subjects (39.73 ± 9.95 pg/ml, p < 0.001). Nine patients with arrhythmias and some echocardiographic alterations formed subgroup A. Seven patients without cardiac alterations formed subgroup B. No significant difference in ANH emerged between the two subgroups. This evidence suggests that high plasma ANH levels in MyD cannot always be related to overt or latent heart failure and to arrhythmias.
Transient Global Amnesia and Migraine
Authors: Schmidtke Klaus , Ehmsen Lutz
Published: April 2003

This study examined the putative association of transient global amnesia (TGA) and migraine. 57 TGA patients were compared to a double-size control group of normal subjects. TGA patients who also had migraine were additionally compared to those without migraine and to a second control group of outpatients with migraine only. The prevalence of migraine, and also of episodic tension-type headache, was markedly increased among TGA patients. Precipitants and accompanying vegetative symptoms of TGA and migraine overlapped. However, there was no evidence of an interaction between TGA and migraine, in that the expression of key TGA features was not affected by comorbidity with migraine, and vice versa. The present findings argue against the hypothesis that TGA represents a type of migraine aura or migraine equivalent. They conform to the hypothesis that the two conditions are essentially independent and result from an inherited brain state that disposes to different types of paroxysmal dysregulation, presumably at the level of the brain stem.
Practical Suggestions in Diagnosing Metachromatic Leukodystrophy in Probands andin Testing Family Members
Authors: Tylki-Szymańska Anna , Czartoryska Barbara , Ługowska Agnieszka
Published: April 2003

Metachromatic leukodystrophy (MLD) is one of the most severe genetically determined demyelination diseases. It is caused by a deficit in the activity of sulfatide sulfatase. The diagnosis is made by demonstrating a deficiency of arylsulfatase A (ASA) activity in leukocytes or cultured skin fibroblasts. Diagnosis based only on the activity of ASA is complicated by the fact that there exists a condition of ASA pseudodeficiency (Pd). Due to the relatively high risk of the MLD/Pd and MLDPd/Pd genotypes among families of patients, it is possible to make an erroneous diagnosis on the basis of only ASA activity. Nonetheless, it seems necessary to develop a reliable and simple diagnostic procedure so as to enable diagnosis and genetic counseling for carriers. We present two diagnostic flow charts entailing determination of ASA activity, identification of the pseudodeficit mutation and detection of sulfatides in a 24-hour urine collection.
Manifestation of Hashimoto’s Encephalopathy Years before Onset of Thyroid Disease
Authors: Peschen-Rosin R. , Schabet M. , Dichgans J.
Published: April 2003

Patients with Hashimoto’s encephalopathy (HE), a steroid-responsive disorder, associated with Hashimoto’s disease and high levels of thyroid-related autoantibodies usually present with a subacute onset of confusion, focal or generalized seizures. Frequent EEG abnormalities include generalized, rhythmic bifrontal or temporal slowing. Elevated protein levels or an intrathecal IgG synthesis may be present in cerebrospinal fluid (CSF). A 39-year-old woman underwent a relapsing course of myocloni and generalized seizures. Initially, thyroid function, thyroid-related autoantibody screening and cerebral MRI were unrevealing. CSF showed oligoclonal bands. Short-term treatment with high doses of prednisolone resolved the myocloni. During the 5th episode of myocloni, signs of hyperthyroidism and elevation of thyroid microsomal antibody titer developed. Hashimoto’s thyroiditis and HE were diagnosed. After subtotal thyroidectomy the patient remained asymptomatic.