bluuebunny/crossref_metadata_2025 huggingface dataset:
Parenteral Indomethacin (The Indotest) in Cluster Headache
Authors: Antonaci F , Costa A , Ghirmai S , Sances G , Sjaastad O , Nappi G
Published: December 2004

The interval between indomethacin administration and clinical response may be extremely relevant in the assessment of chronic paroxysmal hemicrania (CPH) and other unilateral headache disorders like cluster headache (CH), with which CPH can be confounded. Indomethacin is inactive in CH; however, in some anecdotal reports in recent years, doubt has been cast on the ineffectiveness of indomethacin in CH. In this study, we have re-assessed the effect of indomethacin treatment in a group of 18 patients with episodic CH (three females and 15 males). From the day 8 of the active period, indomethacin 100 mg i.m. was administered every 12 h, for 2 consecutive days, in an open fashion. The mean daily attack frequency before the test (1.6 ± 0.6) was not statistically different from that on day 1 (2.1 ± 0.9) and day 2 (1.9 ± 0.8) after indomethacin administration. The mean interval between indomethacin injection and the following attack (day 1 and day 2) was 4.6 + 1.1 h. We did not observe any refractory period in any patient after indomethacin. Since the ‘expected’ attack occurred when there theoretically could have been a protective effect after indomethacin administration, it can be reasonably assumed that there is no such protective effect. The use of a test dose of 100 mg i.m. indomethacin (INDOTEST) appears to provide a clear-cut answer in this situation. It may be a useful tool for a proper clinical assessment of unilateral headache with relatively short-lasting attacks when problems of classification arise. A correct diagnosis of CPH or CH is important, since a CPH diagnosis may imply a lifelong treatment with a potentially noxious drug.
Effect of the Adenosine A1 Receptor Agonist Gr79236 on Trigeminal Nociception with Blink Reflex Recordings in Healthy Human Subjects
Authors: Giffin NJ , Kowacs F , Libri V , Williams P , Goadsby PJ , Kaube H
Published: December 2004

GR79236 is a highly potent and selective adenosine A1 receptor agonist that has analgesic and anti-inflammatory actions in humans and animals. In animal models it inhibits trigeminal nerve firing and calcitonin gene-related peptide release which play a pivotal role in migraine pathophysiology. Thus GR79236 may have therapeutic potential in migraine. Although there are no validated human models of migraine, the trigeminal nociceptive pathways may be studied with a novel electrode to elicit nociception-specific blink reflex responses. Twelve healthy female volunteers were randomized in a double-blind, placebo-controlled, crossover trial to investigate the effect of GR79236 on trigeminal nociceptive pathways, as measured by the blink reflex. A secondary objective was to compare the use of two types of electrode, the standard (SE) and nociception-specific electrodes (NE), to investigate human trigeminal pharmacology. Blink reflexes were elicited with SE and NE before and 30 min after GR79236 (10 μg/kg i.v.) or placebo. The median area under the curve of repeated sweeps of the R2 component of the blink reflex was analysed using analysis of covariance with baseline as covariate. Using NE, GR79236 produced a non-significant reduction of the ipsilateral R2 compared with placebo ( P = 0.097) and a significant reduction contralaterally ( P = 0.008). No significant changes were observed using SE. There were no significant adverse events. The results suggest that NE is more sensitive than SE to detect pharmacological effects in the trigeminal nociceptive system. Furthermore, the adenosine A1 receptor agonist GR79236 inhibits trigeminal nociception in humans. These results support a possible therapeutic role for GR79236 in primary headache disorders.
Menstrual Migraine in A Representative Dutch Population Sample: Prevalence, Disability and Treatment
Authors: Couturier EGM , Bomhof MAM , Neven A Knuistingh , van Duijn NP
Published: December 2004

We assessed the prevalence of menstrual migraine and its restrictions on daily activities in a representative Dutch population sample of 1181 Dutch women, aged 13-55 years. Further, we evaluated the potential role of oral contraceptives, and how menstrual migraine is treated. More than half suffered from menstrual complaints, a substantial proportion reported headache or migraine as a frequent problem. Use of oral contraceptives seemed to reduce the occurrence of menstrual complaints, but not the occurrence of headache and migraine. In our study, the prevalence of menstrual migraine (3%) is lower than in the literature, most probably because we did not use a selected group of patients but a population-based sample of ordinary women. It was confirmed that attacks of menstrual migraine are more severe, of longer duration, and more resistant to treatment than migraine attacks at other times of the month.
Frequent Migraine and Migraine Status Without Tension-Type Headaches: an Unusual Presentation of Rebound Headaches
Authors: Warner JS
Published: December 2004

Rebound headaches usually present as daily or almost daily, prolonged, generalized tension-type headaches with superimposed migraine-like attacks. The latter are more frequent, more intense, and longer than any episodic migraine that the patient might have experienced prior to the development of the chronic daily headaches. Rebound presenting as migraine without tension-type pain has been mentioned in a few previous articles on chronic daily headache, but there have been no previous articles stressing that frequent migraine might relate to the analgesics that are being used. These case histories are presented to illustrate that frequent migraine and migraine status without tension-type headaches may be manifestations of rebound and improve when the offending analgesic agents are stopped. If the clinician fails to recognize this unusual presentation of rebound headache, the patient might be placed on unnecessary and often ineffective medications for prophylaxis instead of stopping the offending pain relief medications.
Personality Traits, Depression and Migraine in Women: A Longitudinal Study
Authors: Mongini F , Keller R , Deregibus A , Raviola F , Mongini T , Sancarlo M
Published: December 2004

Our purpose was to examine the association between personality traits, depression and migraine in the long term. In 56 women with migraine a psychological assessment was carried out to assess the presence of major depression, and the Minnesota Multiphasic Personality Inventory (MMPI) and the State and Trait Anxiety Inventory (STAI) were administered at baseline (T0) and after 6-7 years (T2). Frequency, severity and duration of migraine were recorded at T0, after treatment (T1) and at T2, and their relation to the prevalence of depression and to the MMPI and STAI data was examined (ANOVA, Student's t-test, X2 analysis, and multiple regression analysis). Pain parameters improved in all patients in T0-T1, but at T2 were higher in patients with depression at T0. The patients whose migraine improved at T2 had, at T0 and T2, significantly lower MMPI and STAI scores. Multiple regression analysis showed a correlation of the MMPI depression score and STAI 1,2 scores at T0 with headache frequency at T2. We conclude that the co-occurrence of migraine, personality changes and depression in women does not appear to influence the results of treatment at short-term, but it seems to be influential on headache history in the long term.
Prevalence, Characteristics, and Patterns of Health Care Use for Chronic Headache in Two Areas of Italy. Results of A Questionnaire Interview in General Practice
Authors: Beghi E , Monticelli ML , Amoruso L , Zarrelli MM
Published: December 2004

We set out to define the prevalence, clinical features and severity of chronic headache among the affiliates of two groups of general practitioners (GPs) and to illustrate the diagnostic and therapeutic modalities employed. A semistructured questionnaire was completed for 2291 children and adults, seen at office or home consultations over a 6-month period by 44 GPs in two areas of Northern Italy (Varese and Sondrio) and Southern Italy (San Giovanni Rotondo), to assess the presence and the clinical features of chronic headache, the severity of the disease (i.e. the degree of interference with work and daily living activities), the diagnostic work-up, and the main treatment modalities. GPs attempted the classification of headache according to the International Headache Society (IHS) criteria. The sample comprised 910 men and 1381 women aged 2-92 years; 39% of cases reported chronic headache (Varese/Sondrio 40%; San Giovanni Rotondo 38%; men 28%; women 47%). Headache was mostly present for >10 years, with one to three attacks/month lasting 4-24 h. Headache was mild in 18% of cases, moderate in 29%, severe in 24%, and very severe in 29%. Diagnostic assessment and treatment varied in the study areas. Diagnostic work-up, hospital admissions, referral to headache centres, and treatment modalities tended to be correlated with headache severity. The GPs could not classify headache using the IHS categories in 27% of cases (Varese/Sondrio 11%; San Giovanni Rotondo 78%). An inverse correlation was found between case classification and use of subsidiary diagnostic and therapeutic aids. Chronic headache is common among individuals seen in general practice. The patterns of health care use tend to be correlated to its severity. A better knowledge of the IHS criteria may be directly related to lower management costs.
Possible Role of α-Adrenoceptor Subtypes in Acute Migraine Therapy
Authors: Willems EW , Valdivia LF , Villalón CM , Saxena PR
Published: December 2004

Even though the underlying mechanisms for the pathophysiology of migraine attacks are not completely understood, little doubt exists that the headache phase is explained by dilatation of cranial, extracerebral blood vessels. In this context, experimental models predictive for anti-migraine activity have shown that both triptans and ergot alkaloids, which abort migraine headache, produce vasoconstriction within the carotid circulation of different species. In contrast to the well-established role of serotonin (5-hydroxytryptamine; 5-HT) 5-HT1B receptors in the common carotid vascular bed, the role of α-adrenoceptors and their subtypes has been examined only relatively recently. Using experimental animal models and α1- and α2-adrenoceptor agonists (phenylephrine and BHT933, respectively) and antagonists (prazosin and rauwolscine, respectively), it was shown that activation of either receptor produces a cranioselective vasoconstriction. Subsequently, investigations employing relatively selective antagonists at α1- (α1A, α1B, α1D) and α2- (α2A, α2B, α2C) adrenoceptor subtypes revealed that specific receptors mediate the carotid haemodynamic responses in these animals. From these observations, together with the potential limited role of α1B-and α2C-adrenoceptors in the regulation of systemic haemodynamic responses, it is suggested that selective agonists at these receptors may provide a promising novel avenue for the development of acute anti-migraine drugs.
Glutamate and Nitric Oxide Pathway in Chronic Daily Headache: Evidence From Cerebrospinal Fluid
Authors: Gallai V , Alberti A , Gallai B , Coppola F , Floridi A , Sarchielli P
Published: December 2004

A central sensitization has been advocated to explain chronic daily headache (CDH) due to sustained peripheral sensitization of algogenic structures responsible for sustained trigeminovascular system activation. Several mechanisms have been suggested to underlie central sensitization, but have been poorly investigated in CDH. They involve N-methyl-D-aspartate (NMDA) receptor activation and nitric oxide (NO) production and supersensitivity and increased and maintained production of sensory neuropeptides. The present study supports the above pathogenic mechanisms demonstrating a significant increase in glutamate and nitrite levels in the CSF of CDH patients, without a significant difference between patients without and those with analgesic overuse headache ( P < 0.0001 and P < 0.002). The increase in CSF nitrites was accompanied by a significant rise in the CSF values of cyclic guanosine monophosphate (cGMP) in patients in comparison with controls ( P < 0.0001). A statistically significant correlation emerged between visual analogic scale (VAS) values and glutamate, nitrites and cGMP. Although substance P (SP) and calcitonin gene-related peptide (CGRP), and to a lesser extent neurokinin A, were significantly increased in CSF compared with control subjects, their values did not correlate with glutamate, nitrites and cGMP levels in CSF in the patient group. The present study confirms the involvement of glutamate-NO-cGMP-mediated events underlying chronic head pain that could be the target of a new therapeutic approach which should be investigated.
Cluster Headache Associated with Sleep Apnoea
Authors: Nobre ME , Filho PFM , Dominici M
Published: December 2004

This study of sleep changes in patients with cluster headache (CH) was conducted in view of the nocturnal predominance of this condition, the efficacy of oxygen and the fact that the attacks follow oxygen desaturation. Proposed mechanisms include impairment of carotid body activity secondary to hypothalamic vasomotor regulatory dysfunction. Sixteen patients with episodic CH and 29 healthy volunteers underwent nocturnal polysomnography. Five (31.3%) patients with episodic CH were found to have sleep apnoea (SA). Two patients with SA experienced two attacks during the study period. The attacks followed episodes of oxygen desaturation and were associated with REM sleep. In two patients with SA and CH, treatment with continuous positive airway pressure abolished their oxygen desaturation, sleep apnoeas and headaches. Our study confirmed the high percentage of CH associated with SA. We suggest that oxygen desaturation may be a trigger factor in some patients and play a role in the pathogenesis of CH.
Electroencephalography in Migraine: A Review with Focus on Quantitative Electroencephalography and the Migraine Vs. Epilepsy Relationship
Authors: Sand T
Published: December 2004

Animal models for migraine have provided substantial advances on the mechanisms and mediators underlying migraine attacks. The neurogenic inflammation model has helped understanding the perivascular mechanisms underlying the pathophysiology of migraine attacks, the receptors involved and the effect of specific antimigraine drugs. The model based on probing the neuronal effects of nitroglycerin – an organic nitrate known to induce spontaneous-like migraine attacks in predisposed subjects – in the rat has provided interesting insights into the neuroanatomic circuits and neuropharmacological mechanisms involved in the initiation and repetition of migraine attacks.
Trigeminofacial Reflexes in Primary Headaches
Authors: Cecchini A Proietti , Sandrini G , Fokin I.V. , Moglia A , Nappi G
Published: December 2004

Nociceptive processing in trigeminal system is likely to undergo to significant changes in chronic pain disorders such as in primary headache.

The electrophysiological testing of brainstem reflexes seems to offer a valuable adjunct to the clinical evaluation, providing direct evidence for central dysmodulation of sensory and pain neurotransmission, i.e. dishabituation pattern and reduced pain threshold.

We review the contribution of trigeminofacial reflex studies in the light of those recent data supporting the view of a dysfunctional sensory processing in primary headache.
Migraine and Idiopathic Narcolepsy – A Case-Control Study
Authors: Evers Stefan ,   The DMKG Study Group
Published: December 2004

In order to evaluate a possible association between migraine and idiopathic narcolepsy, we performed a multicentre case-control study on the comorbidity of narcolepsy and different headaches. In total, 96 patients with idiopathic narcolepsy were enrolled. The migraine frequency in the patients and in the control group was 21.9% and 19.8%, respectively ( P = 0.722). The migraine features did not differ significantly between both groups. However, headache fulfilling the criteria for tension-type headache was significantly more often reported by narcolepsy patients than by the control group (60.3% vs. 40.7%, P = 0.006). We conclude that there is no association between migraine and narcolepsy but that patients with narcolepsy show more unspecific headache, probably due to sleep disturbances.
Peripheral and Central Activation of Trigeminal Pain Pathways in Migraine: Data From Experimental Animal Models
Authors: Buzzi MG , Tassorelli C , Nappi G
Published: December 2004

EEG-studies in migraine in the last decade has contributed modestly to the understanding of headache pathogenesis. Headache patient groups seem to have increased EEG responses to photic stimulation, but a useful biological marker for migraine in single patients has not been found. In future EEG and QEEG studies we recommend to use follow-up designs and record several EEGs across the migraine cycle. It is also important to use a blinded study design in order to avoid selection bias.

A clinical EEG should be performed in patients with acute headache attacks when either epilepsy, basilar migraine, migraine with prolonged aura or alternating hemiplegia is suspected. Unequivocal epileptiform abnormalities usually suggest a diagnosis of epilepsy. In children with occipital spike-wave activity the probable diagnosis is childhood epilepsy with occipital paroxysms (CEOP). The final diagnosis of either an epilepsy syndrome or migraine must be mainly based on a clinical judgement.
Relating species abundance distributions to species‐area curves in two Mediterranean‐type shrublands
Authors: Keeley Jon E.
Published: December 2004

Abstract. Based on both theoretical and empirical studies there is evidence that different species abundance distributions underlie different species‐area relationships. Here I show that Australian and Californian shrubland communities (at the scale from 1 to 1000 m2) exhibit different species‐area relationships and different species abundance patterns. The species‐area relationship in Australian heathlands best fits an exponential model and species abundance (based on both density and cover) follows a narrow log normal distribution. In contrast, the species‐area relationship in Californian shrublands is best fit with the power model and, although species abundance appears to fit a log normal distribution, the distribution is much broader than in Australian heathlands. I hypothesize that the primary driver of these differences is the abundance of small‐stature annual species in California and the lack of annuals in Australian heathlands. Species‐area is best fit by an exponential model in Australian heathlands because the bulk of the species are common and thus the species‐area curves initially rise rapidly between 1 and 100 m2. Annuals in Californian shrublands generate very broad species abundance distributions with many uncommon or rare species. The power function is a better model in these communities because richness increases slowly from 1 to 100 m2 but more rapidly between 100 and 1000 m2 due to the abundance of rare or uncommon species that are more likely to be encountered at coarser spatial scales. The implications of this study are that both the exponential and power function models are legitimate representations of species‐area relationships in different plant communities. Also, structural differences in community organization, arising from different species abundance distributions, may lead to different species‐area curves, and this may be tied to patterns of life form distribution.
Comparative phylogeography of salmonid fishes (Salmonidae) reveals late to post‐Pleistocene exchange between three now‐disjunct river basins in Siberia
Authors: Froufe E. , Alekseyev S. , Knizhin I. , Alexandrino P. , Weiss S.
Published: December 2004

Abstract. We use a comparative phylogeographical framework to evaluate the hypothesis of hydrological exchange during the Pleistocene among the now disjunct Lena, Amur, and Enisei basins in Siberia, and to provide evidence on the causal mechanism of their present day faunal dissimilarities. Approximately 600 bases of the mitochondrial control region were sequenced in five distinct lineages among three genera of salmonid fishes, Hucho, Brachymystax and Thymallus. All three basins were fixed for divergent (2–5.4%) lineages of Thymallus whereas a single shared haplotype was present in all three basins for Hucho taimen (Pallas, 1773) and one shared haplotype between the Lena and Amur basins out of a total of five for blunt‐snouted and one out of five for sharp‐snouted Brachymystax lenok (Pallas, 1773). For both blunt‐ and sharp‐snouted lenok the haplotypes found within each basin did not form clades, so no relationship between genotypes and geographical occurrence was found. Our data support relatively recent hydrological mixing of the major river drainage systems in eastern and far‐eastern Siberia, congruent with the hypothesis of large‐scale palaeo‐hydrological exchange stemming from glacial advance, retreat and melting during Pleistocene climate fluctuations. Furthermore, these results in conjunction with a comparison of overall faunal composition suggest that environmental differences rather than historical contingency may be responsible for the faunal dissimilarities of the Amur, Lena, and Enisei river basins.
Performance of nonparametric species richness estimators in a high diversity plant community
Authors: Chiarucci A. , Enright N. J. , Perry G. L. W. , Miller B. P. , Lamont B. B.
Published: December 2004

Abstract. The efficiency of four nonparametric species richness estimators — first‐order Jackknife, second‐order Jackknife, Chao2 and Bootstrap — was tested using simulated quadrat sampling of two field data sets (a sandy ‘Dune’ and adjacent ‘Swale’) in high diversity shrublands (kwongan) in south‐western Australia. The data sets each comprised > 100 perennial plant species and > 10 000 individuals, and the explicit (x‐y co‐ordinate) location of every individual. We applied two simulated sampling strategies to these data sets based on sampling quadrats of unit sizes 1/400th and 1/100th of total plot area. For each site and sampling strategy we obtained 250 independent sample curves, of 250 quadrats each, and compared the estimators’ performances by using three indices of bias and precision: MRE (mean relative error), MSRE (mean squared relative error) and OVER (percentage overestimation). The analysis presented here is unique in providing sample estimates derived from a complete, field‐based population census for a high diversity plant community. In general the true reference value was approached faster for a comparable area sampled for the smaller quadrat size and for the swale field data set, which was characterized by smaller plant size and higher plant density. Nevertheless, at least 15–30% of the total area needed to be sampled before reasonable estimates of St (total species richness) were obtained. In most field surveys, typically less than 1% of the total study domain is likely to be sampled, and at this sampling intensity underestimation is a problem. Results showed that the second‐order Jackknife approached the actual value of St more quickly than the other estimators. All four estimators were better than Sobs (observed number of species). However, the behaviour of the tested estimators was not as good as expected, and even with large sample size (number of quadrats sampled) all of them failed to provide reliable estimates. First‐ and second‐order Jackknives were positively biased whereas Chao2 and Bootstrap were negatively biased. The observed limitations in the estimators’ performance suggests that there is still scope for new tools to be developed by statisticians to assist in the estimation of species richness from sample data, especially in communities with high species richness.
Phytogeographic analysis of taxa endemic to the Yucatán Peninsula using geographic information systems, the domain heuristic method and parsimony analysis of endemicity
Authors: Manrique Celene Espadas , Durán Rafael , Argáez Jorge
Published: December 2004

Abstract. The distribution of plant taxa endemic to the Yucatán Peninsula was studied using Parsimony Analysis of Endemicity (PAE). The known distribution of 162 endemic plant taxa was plotted and the DOMAIN method together with environmental data were used to model the potential distribution for each taxon. The Peninsula was divided into a grid of quarter‐degree cells for the purpose of identifying distribution patterns. A total of 294 cells were analysed using known collection records and potential distribution of endemic taxa data. Two data matrices were constructed, a matrix of known distribution and a matrix of both the known and potential distribution. The two matrices were included in the PAE to identify areas of endemism. The areas determined with the known distribution were restricted and almost half of them remained unresolved, whereas with the potential distribution, approximately 90% of the cells were assigned to any one of the endemicity areas. Four endemism areas were identified: the Yucatán dry zone, Yucatán, El Petén and Belize. The areas of Yucatán and El Petén could be explained by current and Pleistocene climatic conditions and their congruence with other biological groups. Analysis of the potential distribution identified areas with patterns that share current environmental characteristics and a palaeoclimate history. Potential distribution modelling can eliminate uncertainties in biogeographical analysis caused by lack of data distribution and sample variation and produce information about the relationships between areas and taxa as well as the environmental affinities of taxa.
Poincaré plot indexes of heart rate variability capture dynamic adaptations after haemodialysis in chronic renal failure patients
Authors: Claudia Lerma , Oscar Infante , Héctor Pérez‐Grovas , Marco V. José
Published: December 2004

The hypothesis that the Poincaré plot indexes of heart rate variability (HRV) detect dynamic changes after haemodialysis (HD) over the HRV in haemodynamically stable chronic renal failure (CRF) patients was examined. Minor axis (SD1), major axis (SD2) and the SD1/SD2 ratio were compared against standard HRV indexes in time and frequency domain, in a group of healthy subjects and in a group of CRF patients before and after HD. These indexes were estimated from Poincaré plots reconstructed with lags of one, two and four heartbeats. The surrogate data analysis technique was applied in order to discern if only random components or linear features of HRV contribute to its dynamics. None of the standard linear HRV indexes changed after HD. The Poincaré plot indexes measured from CRF patients were smaller than the ones measured from healthy subjects. In CRF patients the SD1/SD2 ratio decreased after HD, when a lag of four heartbeats was used (0·68 ± 0·19 before HD versus 0·55 ± 0·12 after HD, P<0·05). The presence of deterministic components in HRV were confirmed for all measures of the SD1/SD2 ratio. Moreover, a loss of non‐linear components after HD was detected by the surrogate analysis over the SD1/SD2 ratio with a lag of four heartbeats. In conclusion, the SD1/SD2 ratio measured at lag of 4 heartbeats capture dynamic changes after HD upon the HRV of CRF patients that are not solely related to linear autocorrelations of HRV. This suggests that the SD1/SD2 ratio reflects non‐linear information of HRV.
Beat‐to‐beat measurement of the finger arterial pressure pulse shape index at rest and during exercise
Authors: Raamat Rein , Jagomägi Kersti , Talts Jaak , Toska Karin , Walløe Lars
Published: December 2004

Arterial pressure waveform can be characterized by the pulse shape index kpulse determined as kpulse = (Pmean − Pdiast) / (Psyst − Pdiast). For brachial artery, the shape index value of 0·33 is usually applied to approximate Pmean from the measured Psyst and Pdiast. Our purpose was to test whether this value can validly be applied to finger vascular beds under different experimental conditions. By using Finapres®, we non‐invasively estimated the beat‐to‐beat values of kpulse in the fingers of young healthy persons in supine position at rest and during a 4‐min moderate exercise (rhythmical exercise with the quadricep muscles in combination with handgrip compression). To detect intensive peripheral vasoconstrictions, a laser‐Doppler probe was attached to the thumb pulp of the same hand. Periods of 30 s without intensive vasoconstriction for rest, different stages of exercise and recovery were involved in the analysis in every subject. The results demonstrated that the group‐averaged value of kpulse (median with a 95% confidence interval) in the fingers of 11 healthy volunteers aged from 20 to 24, equalled 0·33 (0·31– 0·34), 0·31 (0·28–0·34), 0·35 (0·33–0·39) and 0·38 (0·34–0·43) for rest, first and second stages of exercise and recovery, respectively. We conclude that in the fingers of young healthy persons in supine position formula Pmean = Pdiast + 1/3 (Psyst − Pdiast) gives an adequate approximation for rest and low intensity exercise (first stage), and slightly underestimates the actual finger mean blood pressure during moderate exercise (second stage) and recovery.
Cerebral oxygenation responses to standing in elderly patients with predominantly diastolic dysfunction
Authors: Mehagnoul‐Schipper D. Jannet , Vloet Lilian C.M. , Colier Willy N.J.M. , Hoefnagels Willibrord H.L. , Verheugt Freek W.A. , Jansen René W.M.M.
Published: December 2004

Patients with left ventricular dysfunction may have different orthostatic responses of blood pressure (BP) and cerebral oxygenation than healthy elderly subjects. We investigated orthostatic changes in systemic haemodynamic variables and cerebral oxygenation in 21 elderly patients with heart failure New York Heart Association class I–III in stable condition (age 70–83 years) after withdrawal of furosemide and captopril for 2 weeks, and in 18 healthy elderly subjects (age 70–84 years). Frontal cortical concentration changes of oxyhaemoglobin ([O2Hb]) and deoxyhaemoglobin ([HHb]) were continuously measured by near‐infrared spectrophotometry and BP changes by Finapres before and during 10 min of standing. Upon standing [O2Hb] reflecting blood flow, changed by −1·2 ± 0·9 μmol L−1 (mean ± SEM) in the patients, whereas it decreased by −4·5 ± 0·6 μmol L−1 (P<0·01) in the healthy subjects after standing (P<0·05 between groups). [HHb] reflecting the sum of cerebral blood flow, arterial oxygen saturation and cerebral oxygen uptake, increased by 1·5 ± 0·5 μmol L−1 (P<0·05) and 1·7 ± 0·6 μmol L−1 (P<0·05), respectively. Compared with healthy elderly subjects, elderly patients with left ventricular dysfunction showed smaller orthostatic [O2Hb] decreases (P<0·01), in relation to higher orthostatic BP rises (P<0·05). These findings indicate that BP changes and an altered cardiovascular balance may influence orthostatic cortical haemodynamic responses in elderly subjects.
31P MRS evaluation of fatigue in anterior tibial muscle in postpoliomyelitis patients and healthy volunteers
Authors: Ljungberg M. , Stibrant Sunnerhagen K. , Vikhoff‐Baaz B. , Starck G. , Forssell‐Aronsson E. , Hedberg M. , Ekholm S. , Grimby G.
Published: December 2004

Changes in concentration of high energy phosphates and pH were studied during rest, exercise and subsequent recovery in the anterior tibial muscle of 10 patients with late effects of poliomyelitis and 10 age‐ and sex‐matched healthy volunteers using31P MRS. The exercise was dynamic and isometric, and the force levels were individually adapted to each subject and stepwise increased. In general, there were no differences in metabolite changes between the groups, except for lower Piand Pi/PCr for the volunteers during the recovery phase, also reflected by shorter recovery half‐time for Pi. The interindividual variation was much higher for the patient group. Some of the patients showed deviating results probably because of differences in muscle fibre type.
Short‐term correlation properties of R–R interval dynamics at different exercise intensity levels
Authors: Hautala Arto J. , Mäkikallio Timo H. , Seppänen Tapio , Huikuri Heikki V. , Tulppo Mikko P.
Published: December 2004

Methods based on non‐linear heart rate (HR) dynamics have been suggested to probe features in HR behaviour that are not easily detected by the traditional HR variability indices. This study tested the hypothesis that analysis of correlation properties of R–R intervals provides useful information on HR fluctuation during exercise. High‐ (HF) and low‐frequency (LF) spectral components and a short‐term scaling exponent (α1) of HR variability, were analysed for nine healthy subjects at rest, during incremental and steady‐state exercise, during atropine infusion and during incremental exercise after atropine administration. During the incremental exercise test α1 increased from rest to an intensity level of ∼40% of (from 1·07 ± 0·24 to 1·50 ± 0·25, P<0·001) and thereafter decreased linearly until the end of exercise (from 1·50 ± 0·25 to 0·38 ± 0·10, P<0·001). Atropine infusion increased the scaling exponent α1 value from 0·91 ± 0·23 to 1·37 ± 0·31 (P<0·001). During exercise after atropine infusion, a linear reduction was observed in the scaling exponent α1 from 1·37 ± 0·23 to 0·25 ± 0·08 (P<0·001). Analogous changes in α1 were seen during long‐term steady‐state exercise compared to incremental exercise. Conventional HR variability indices did not show any significant changes during exercise at high exercise intensity levels. α1 correlated with the LF/HF ratio at rest (r = 0·90, P<0·001), but the correlation was weaker after atropine (r = 0·71, P<0·05) and during exercise (e.g. r = 0·33, P = NS at the level of 40% of ). In conclusion, incremental exercise test until exhaustion results in bidirectional changes in correlation properties of R–R interval dynamics. These changes can be explained by the intensity of vagal and sympathetic input to the sinus node during the different intensity levels of exercise. Changes in α1 values can be detected also in high intensity levels, when the conventional measures of HR variability can not be applied.
Rapid evolution of a polyphenic threshold
Authors: Moczek Armin P. , Nijhout H. Frederik
Published: December 2004

SUMMARYPolyphenisms are thought to play an important role in the evolution of phenotypic diversity and the origin of morphological and behavioral novelties. However, the extent to which polyphenic developmental mechanisms evolve in natural populations is unknown. Here we contrast patterns of male phenotype expression in native and exotic and ancestral and descendant populations of the horn polyphenic beetle,Onthophagus taurus.Males in this species express two alternative morphologies in response to larval feeding conditions. Favorable conditions cause males to grow larger than a threshold body size and to develop a pair of horns on their heads. Males that encounter relatively poor conditions do not reach this threshold size and remain hornless. We show that exotic and native populations ofO. taurusdiffer significantly in the body size threshold that separates alternative male phenotypes. Comparison with archival museum collections and additional samples obtained from the native range ofO. taurussuggests that allometric differences between exotic and native populations do not reflect preexisting variation in the native range of this species. Instead, our data suggest that threshold divergences between exotic and native populations have evolved in less than 40 years since the introduction to a new habitat and have proceeded in opposite directions in two exotic ranges of this species. Finally, we show that the kind and magnitude of threshold divergence between native and exotic populations are similar to differences normally observed between species. Our results support the view that certain components of the developmental control mechanism that underlie polyphenic development can evolve rapidly in natural populations and may provide important avenues for phenotypic differentiation and diversification in nature. We discuss the role of developmental control mechanisms in the origin of allometric diversification and explore potential evolutionary mechanisms that could drive scaling relationship evolution in nature.
Variation of tooth number in mammalian dentition: connecting genetics, development, and evolution
Authors: Line Sergio R. P.
Published: December 2004

SUMMARY A major question in modern biology is how gene mutations affect development and are translated into macroevolutionary changes in morphology. Variations in tooth number, a strategy used by many mammals to develop specialized dentitions, has been an important factor for species diversification. Changes in the number of teeth tend to occur in the reverse of the order teeth are formed during development, which also characterizes the general pattern of tooth loss observed during the evolution of placental mammals. To understand how changes at the molecular level affect the distinct stages of tooth development, we analyzed the ontogenesis of tooth growth arrest in sciurids and mice and in single and double knockout mutant mice. We show that the complexity of the genetic network that governs tooth development can change during ontogenetic trajectory, and these changes may be related to macroevolutionary changes. Furthermore, we show that the variation in tooth number in the affected members of human families bearing mutations in the MSX1 and PAX9 genes can help to understand how the genetic variations within a population can modulate evolutionary changes in dental patterning.
Early evolution of a homeobox gene: the parahox gene Gsx in the Cnidaria and the Bilateria
Authors: Finnerty John R. , Paulson David , Burton Pat , Pang Kevin , Martindale Mark Q.
Published: December 2004

Summary Homeobox transcription factors are commonly involved in developmental regulation in diverse eukaryotes, including plants, animals, and fungi. The origin of novel homeobox genes is thought to have contributed to many evolutionary innovations in animals. We perform a molecular phylogenetic analysis of cnox2, the best studied homeobox gene from the phylum Cnidaria, a very ancient lineage of animals. Among three competing hypotheses, our analysis decisively favors the hypothesis that cnox2 is orthologous to the gsx gene of Bilateria, thereby establishing the existence of this specific homeobox gene in the eumetazoan stem lineage, some 650–900 million years ago. We assayed the expression of gsx in the planula larva and polyp of the sea anemone Nematostella vectensis using in situ hybridization and reverse transcriptase polymerase chain reaction. The gsx ortholog of Nematostella, known as anthox2, is expressed at high levels in the posterior planula and the corresponding “head” region of the polyp. It cannot be detected in the anterior planula or the corresponding “foot” region of the polyp. We have attempted to reconstruct the evolution of gsx spatiotemporal expression in cnidarians and bilaterians using a phylogenetic framework. Because of the surprisingly high degree of variability in gsx expression within the Cnidaria, it is currently not possible to infer unambiguously the ancestral cnidarian condition or the ancestral eumetazoan condition for gsx expression.
Phylogeny and development of marine model species: strongylocentrotid sea urchins
Authors: Biermann Christiane H. , Kessing Bailey D. , Palumbi Stephen R.
Published: December 2004

SummaryThe phylogenetic relationships of ten strongy‐locentrotid sea urchin species were determined using mitochondrial DNA sequences. This phylogeny provides a backdrop for the evolutionary history of one of the most studied groups of sea urchins. Our phylogeny indicates that a major revision of this group is in order. All else remaining unchanged, it supports the inclusion of three additional species into the genusStrongylocentrotus(Hemicentrotus pulcherrimus,Allocentrotus fragilis, andPseudocentrotus depressus). All were once thought to be closely related to this genus, but subsequent revisions separated them into other taxonomic groupings. Most strongylocentrotid species are the result of a recent burst of speciation in the North Pacific that resulted in an ecological diversification. There has been a steady reduction in the complexity of larval skeletons during the expansion of this group. Gamete attributes like egg size, on the other hand, are not correlated with phylogenetic position. In addition, our results indicate that the rate of replacement substitutions is highly variable among phylogenetic lineages. The branches leading toS. purpuratusandS. franciscanuswere three to six times longer than those leading to closely related species.
Echocardiographic Left Ventricular Mass in African‐Americans
Authors: Skelton Thomas N. , Andrew Michael E. , Arnett Donna K. , Burchfiel Cecil M. , Garrison Robert J. , Samdarshi Tandaw E. , Taylor Herman A. , Hutchinson Richard G.
Published: December 2004

Characterization of target organ damage from hypertension is of particular interest in African‐Americans, and evidence from electrocardiographic studies suggests that left ventricular hypertrophy is a frequent clinical finding of considerable prognostic importance. Echocardiographic studies may permit more precise characterization of the pathologic impact of hypertension on cardiac structure and function. The objective of this study is to characterize left ventricular (LV) structure including measures of wall thickness, septal thickness, internal dimension, and mass in a middle‐aged sample of African‐Americans using echocardiography. This study is a cohort (cross‐sectional) study in which 2445 middle‐aged African‐American study participants from a population‐based sample initially enrolled by the Atherosclerosis Risk in Communities, Jackson, Mississippi Examination Center in 1987–1989 underwent an M‐mode echocardiograpic examination at their third or fourth clinic visit in 1993–1996. Measures of LV mass, even where indexed by size were conspicuously greater in men compared to women, and men exhibited a demonstrably steeper gradient of LV mass across the rather restricted age range of the study. However, when gender specific thresholds for LV hypertrophy were utilized, African‐American men appear to have lower prevalence of LV hypertrophy than women. The lowest prevalence of LV hypertrophy was observed in African‐American men who did not have hypertension (28.4%). The findings confirm previous suggestions from electrocardiographic investigations that cardiac hypertrophy is common, if not epidemic in middle‐aged African‐American men and women, whether or not they have hypertension. (ECHOCARDIOGRAPHY, Volume 20, February 2003)
Diffuse Locally Invasive Lipomatosis of the Pericardium
Authors: Akhtar Asif , D'Cruz Ivan A. , Ramanathan K. B. , Umpierrez Monica
Published: December 2004

The chest radiographic, echocardiographic (transthoracic and transesophageal), MRI, CT and cardiac catheterization findings in a 72‐year‐old patient with extensive pericardial lipomatosis are presented. Diastolic pressures in the left heart were elevated. The massive lipomatous mass was partially resected surgically with good symptomatic relief. Histologically the neoplasm consisted of mature non‐malignant adipose tissue. Cushing's Syndrome was absent. (ECHOCARDIOGRAPHY, Volume 20, February 2003)
Transthoracic Echocardiographic Demonstration of Septal Perforator Coronary Arteries–Left Ventricle Fistula
Authors: Sooudi Steven K. , Ahmed Sujood , Nekkanti Rajasekhar , Nanda Navin C.
Published: December 2004

We present an adult patient status post septal myectomy in whom transthoracic two‐dimensional echocardiography demonstrated septal perforator coronary arteries opening directly into the left ventricle. In some views this finding mimicked aortic regurgitation. (ECHOCARDIOGRAPHY, Volume 20, February 2003)
Quantitation of Papillary Muscle Function with Tissue and Strain Doppler Echocardiography Measures Papillary Muscle Contractile Functions
Authors: Dagdelen Sinan , Yuce Murat , Ergelen Mehnmet , Pala Selcuk , Kýrma Cevat
Published: December 2004

It is well known that papillary muscle dysfunction may cause mitral regurgitation, however, there is not a standard technique to measure the papillary muscle function. The aim of this study is to investigate papillary muscle function by using tissue and strain rate Doppler echocardiography. Method: A study group (SG) of 42 patients (12 females, 30 males, mean age:

53.8 ± 10.9

years) with coronary artery disease who have segmental left ventricular dysfunction and mitral regurgitation, and as a control group (CG) 20 patients (6 females, 14 males, mean age

52.5 ± 10.2

years) who have no coronary artery disease and mitral regurgitation were studied. A subgroup 20 patients (7 females, 13 males, mean age

42.5 ± 7.5

years) who have rheumatic mitral regurgitation was included to the study. The patients who have left ventricular and mitral annular dilatation were not included into the study. Longitudinal wall motion of mid‐inferior segment (one point) and posterior papillary muscle (two point) of the left ventricle was assessed by tissue and strain rate Doppler echocardiography from the apical two‐chamber view. Systolic tissue velocity (Sm), strain rate (SR), and strain (S) were measured from the two points in all patients. Results: Comparing the one point values Sm, SR, and S were found less in SG than CG (respectively

4.2 ± 1.4 vs 11.3 ± 1.9 cm/sec, −1.0 ± 0.4 vs −1.7 ± 0.3 s−1, −13.5 ± 5.0 vs −18.1 ± 3.9%; P < 0.001

for all). Comparing the two point values Sm, SR and S were found less in SG than CG (respectively

2.8 ± 1.2 vs 3.7 ± 2.0 cm/sec, −0.8 ± 0.4 vs −1.6 ± 0.3 s−1, −9.7 ± 4.6 vs −15.8 ± 3.7%; P < 0.001

for all). Systolic mitral annulus, left ventricular systolic and diastolic dimensions were similar in two groups. Comparing the CG and subgroup, there were no significant differences with respect to Sm, SR, and S measured from the two points. Conclusions: Papillary muscle function may be assessed quantitatively by using tissue and strain rate Doppler echocardiography. Tissue velocity, strain rate, and strain values were found decreased in dysfunctional papillary muscle. (ECHOCARDIOGRAPHY, Volume 20, February 2003)
Course of Intraatrial Thrombi Resolution Using Transesophageal Echocardiography
Authors: Larsen Jennifer A. , McPherson David D. , Kadish Alan H. , Goldberger Jeffrey J.
Published: December 2004

Thromboembolic events are associated with atrial fibrillation and with cardioversion to sinus rhythm. Although studies have demonstrated the risk of this complication is reduced by a 3‐week period of anticoagulation prior to cardioversion, limited data have suggested a longer period of anticoagulation is necessary for thrombus resolution. We identified and followed 25 patients noted to have intraatrial thrombi on an initial transesophageal echocardiogram (TEE) who subsequently had a follow‐up TEE. The majority of patients had a single thrombus, often but not uniformly located in the left atrial appendage with the largest found in those patients with mitral stenosis. Repeat TEE was performed at a mean of

4 ± 6

months and persistent thrombus was noted in 19 of 25 patients (76%). Seven of 19 patients with persistent thrombi were cardioverted and one of these patients had a neurologic event following the procedure (14%). The only findings associated with persistent thrombus were the presence of mitral valve disease and atrial fibrillation.. Our findings suggest that intraatrial thrombi do not generally resolve following several weeks of anticoagulation and that persistent left‐sided intraatrial thrombi may be associated with an increased risk for events following cardioversion. Given that a TEE‐guided approach to cardioversion is being utilized more frequently, it may be important to determine thrombus characteristics on follow‐up that would be predictive of embolic events following cardioversion. (ECHOCARDIOGRAPHY, Volume 20, February 2003)