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At least 325 records · Page 18Linked to original sources
PubMed2001

Phylogenetic relationships within Cornus (Cornaceae) based on 26S rDNA sequences.

Phylogenetic relationships within the dogwood genus Cornus have been highly controversial due to the great morphological heterogeneity. Earlier phylogenetic analyses of Cornus using chloroplast DNA (cpDNA) data (including rbcL and matK sequences, as well as restriction sites) and morphological characters suggested incongruent relationships within the genus. The present study generated sequence data from the nuclear gene 26S rDNA for Cornus to test the phylogenetic hypotheses based on cpDNA and morphological data. The 26S rDNA sequence data obtained represent 16 species, 13 from Cornus and three from outgroups, having an aligned length of 3380 bp. Both parsimony and maximum likelihood analyses of these sequences were conducted. Trees resulting from these analyses suggest relationships among subgroups of Cornus consistent with those inferred from cpDNA data. That is, the dwarf dogwood (subg. Arctocrania) and the big-bracted dogwood (subg. Cynoxylon and subg. Syncarpea) clades are sisters, which are, in turn, sister to the cornelian cherries (subg. Cornus and subg. Afrocrania). This red-fruited clade is sister to the blue- or white-fruited dogwoods (subg. Mesomora, subg. Kraniopsis, and subg. Yinquania). Within the blue- or white-fruited clade, C. oblonga (subg. Yinquania) is sister to the remainder, and subg. Mesomora is sister to subg. Kraniopsis. These relationships were also suggested by the combined 26S rDNA and cpDNA data, but with higher bootstrap and Bremer support in the combined analysis. The 26S rDNA sequence data of Cornus consist of 12 expansion segments spanning 1034 bp. These expansion segments evolve approximately four times as fast as the conserved core regions. The study provides an example of phylogenetic utility of 26S rDNA sequences below the genus level.

Journal Article↗
PubMedDate not supplied

[Smoking behavior in adolescents: a comparison of population-representative, regional or selectively assessed data and implications for prevention].

INTRODUCTION: The prevalence of adolescent smoking underlines the necessity of preventive measures, which goals are based on representative data. It is not known whether schools participate in prevention interventions, where smoking constitutes a relatively big or minor problem. OBJECTIVE: This study examines a population of adolescents on (a) different smoking variables and (b) compares them with representative, population based data. METHODS: Survey of n = 324 adolescents of grade 7-10 in 3 schools in Greifswald and surroundings that were ready to participate in a prevention curriculum. RESULTS: In total, 80% of the students under examination indicated to have at least tried smoking in their lifetime. Daily smokers were 31%, 18% were occasional smokers, 39% have indicated that they hat tried to quit without success. These figures vary across age, grade and sex. Smoking prevalence is comparable between schools ready to participate in prevention and regionally assessed data, but much higher than population based data would have estimated. CONCLUSION: The goal of preventive measures can not be solely grounded on representative, population-based data, but needs (a) to be regionally defined and (b) to consider the population actually participating in such prevention interventions. The readiness to participate is not higher in schools where smoking constitutes a comparable minor problem. Preventive measures are applied in schools where the problem is perceived.

Adolescent↗
PubMed1998

Predictive agreement between the fetal arterial oxygen saturation and fetal scalp pH: results of the German multicenter study.

OBJECTIVE: To discuss and substantiate the 30% critical threshold of fetal arterial oxygen saturation and to complete the puzzle with low fetal arterial oxygen saturation and low scalp pH data, scalp samples have been performed while fetal arterial oxygen saturation registration during labor was in place and while the saturation was < or = 30%. STUDY DESIGN: Between 1993 and 1996, 46 term fetuses during active labor had parallel arterial oxygen saturation registration by pulse oximetry combined with cardiotocograph. They include patients in whom the saturation was < or = 30% for at least 10 minutes. In these cases scalp pH sample values have been obtained simultaneously. Outcome data, Apgar scores, cord gases, and whether the infants were transferred to the neonatal intensive care unit have been examined. Compared with this, there were other cases during labor that had also parallel fetal arterial oxygen saturation and cardiotocographic registration, where the saturation was > 30%. Also in these cases scalp pH was determined to support and demonstrate the predictive value of fetal arterial oxygen saturation for scalp pH, especially in the low ranges. All 46 fetuses were evaluated during periods of nonreassuring cardiotocograph with Nellcor N-400 Fetal Oxygen Saturation Monitoring Systems and FS 14 B sensors in a multicenter study involving three German obstetric centers. Receiver operating characteristic analysis was done on all raw data, as well as the receiver operating characteristic curve from the preceding analysis. RESULTS: These data validate the critical threshold of 30% fetal arterial oxygen saturation and show an extremely good separation of "good" versus "bad" at a fetal arterial oxygen saturation of 30%, especially when seen in conjunction with data points that are > 7.20. Data at < or = 7.20 scalp pH and < 30% fetal arterial oxygen saturation can be a big help in calculating the sensitivity and specificity of fetal arterial oxygen saturation in predicting neonatal outcome (e.g., Apgar score, cord pH). CONCLUSION: Low fetal arterial oxygen saturation data of < 30% for at least 10 minutes or longer correlate significantly with low scalp pH values and have a predictive value concerning fetal outcome.

Arteries↗
PubMed2002

Male strategies and Plio-Pleistocene archaeology.

Archaeological data are frequently cited in support of the idea that big game hunting drove the evolution of early Homo, mainly through its role in offspring provisioning. This argument has been disputed on two grounds: (1) ethnographic observations on modern foragers show that although hunting may contribute a large fraction of the overall diet, it is an unreliable day-to-day food source, pursued more for status than subsistence; (2) archaeological evidence from the Plio-Pleistocene, coincident with the emergence of Homo can be read to reflect low-yield scavenging, not hunting. Our review of the archaeology yields results consistent with these critiques: (1) early humans acquired large-bodied ungulates primarily by aggressive scavenging, not hunting; (2) meat was consumed at or near the point of acquisition, not at home bases, as the hunting hypothesis requires; (3) carcasses were taken at highly variable rates and in varying degrees of completeness, making meat from big game an even less reliable food source than it is among modern foragers. Collectively, Plio-Pleistocene site location and assemblage composition are consistent with the hypothesis that large carcasses were taken not for purposes of provisioning, but in the context of competitive male displays. Even if meat were acquired more reliably than the archaeology indicates, its consumption cannot account for the significant changes in life history now seen to distinguish early humans from ancestral australopiths. The coincidence between the earliest dates for Homo ergaster and an increase in the archaeological visibility of meat eating that many find so provocative instead reflects: (1) changes in the structure of the environment that concentrated scavenging opportunities in space, making evidence of their pursuit more obvious to archaeologists; (2) H. ergaster's larger body size (itself a consequence of other factors), which improved its ability at interference competition.

Adaptation, Physiological↗
PubMed2006

Impaired vascular function in normoglycemic mice prone to autoimmune diabetes: role of nitric oxide.

Type 1 diabetes is an immuno-inflammatory condition which increases the risk of cardiovascular disease, particularly in young adults. This study investigated whether vascular function is altered in mice prone to autoimmune diabetes and whether the nitric oxide (NO)-cyclic GMP axis is involved. Aortic rings suspended in organ chambers and precontracted with phenylephrine were exposed to cumulative concentrations of acetylcholine. To investigate the role of NO, some experiments were performed in the presence of either 1400W (N-(3-aminomethyl)benzyl-acetamidine hydrochloride), a selective inhibitor of the iNOS-isoform, L-NAME (N(G)-nitro-L-arginine methyl ester hydrochloride), an inhibitor of all three NOS-isoforms, or ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one), a selective inhibitor of guanylate cyclase. Moreover, contractility to phenylephrine, big endothelin-1, and endothelin-1 was assessed and histological analysis and iNOS immunohistochemistry were performed. Endothelium-dependent relaxation was reduced in prediabetic NOD mice (78+/-4 vs. 88+/-2%, respectively, P<0.05 vs. control) despite normal plasma glucose levels (n.s. vs. control). Preincubation with 1400W further attenuated responses in prediabetic (P<0.05 vs. untreated) but not in diabetic or in control mice. In contrast, basal NO bioactivity remained unaffected until the onset of diabetes in NOD mice. Contractile responses to big endothelin-1 and endothelin-1 were reduced in prediabetic animals (P<0.05 vs. control), whereas in diabetic mice only responses to big endothelin-1 were decreased (P<0.05 vs. control). These data demonstrate that endothelium-dependent and -independent vascular function in NOD mice is abnormal already in prediabetes in the absence of structural injury. Early proinflammatory activation due to iNOS in diabetes-prone NOD mice appears to be one of the mechanisms contributing to impaired vasoreactivity.

Acetylcholine↗
PubMed1998

Fatal shoulder dystocia: a review of 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy.

OBJECTIVE: To use information collected by the Confidential Enquiry into Stillbirths and Deaths in Infancy to help obstetric, midwifery and paediatric practice in the management of shoulder dystocia. DESIGN: Review of casenotes by a multidisciplinary focus group. SAMPLE: All 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy from England, Wales and Northern Ireland in 1994 and 1995, where stillbirth or neonatal death was attributed to shoulder dystocia. MAIN OUTCOME MEASURES: Case notes were reviewed with respect to a range of perinatal variables. Comparisons were made with normative data from other studies when appropriate. RESULTS: Maternal obesity and big babies were over-represented in pregnancies complicated by fatal shoulder dystocia. Fetal compromise was recorded in 26% of labours. The median time interval between delivery of the head and the rest of the body was only five minutes. The lead professional at the time the head was delivered was a midwife in 65% of cases. Middle grade or senior obstetric staff were supervising 47% of cases by the time the body was delivered. CONCLUSIONS: Antenatal prediction of shoulder dystocia is imprecise, and the majority of deliveries are attended by midwives. A relatively brief delay in delivery of the shoulders may be associated with a fatal outcome.

Autopsy↗
PubMed1999

Thrombolysis in newborns and infants.

This review analyses literature reports from 1970 to 1998 assessing the use of streptokinase (SK), urokinase (UK) or recombinant tissue-type plasminogen activator (rt-PA) for thrombolytic therapy in neonates and infants. From 1970 to 1998 182 infants were reported to have received SK (n = 54; 29.5%), UK (n = 41; 22.5%) or rt-PA (n = 87; 48%). During thrombolytic therapy no concomitant heparin administration or low dose heparin therapy (5 U/kg/h) were recorded. To perform reocclusion prophylactics heparin was reinitiated at the end of thrombolytic therapy usually in the recommended dosage of 20 U/ kg/h. The overall thrombolytic patency rate in neonates varied from 39% to 86%. Besides bleeding from local puncture sites or recent catheterisation sites (10.4%), pulmonary embolism was reported in 1.1% of the 182 infants. Major bleeding complications, i.e. pulmonary bleeding (0.6%), gastrointestinal bleeding (0.6%) or intraventricular haemorrhage (IVH 2.7%) are rarely reported side effects and only 2 thrombolysis related deaths due to haemorrhage were mentioned. Bleedings reported in the central nervous system (n = 4) mainly occurred in preterm infants (n = 3). In conclusion, data of this preliminary analysis suggest that there is no big difference (p = 0.09; chi2-test) in the efficacy rate between the 3 thrombolytic agents used in the first year of life. In each case an assessment must be made with respect to the relative benefit conferred by thrombolytic therapy in preventing organ or limb damage versus the potential side effects, costs and inconvenience for the childhood patient. Controlled prospective multicentre studies on thrombolytic therapy in neonates and infants are recommended to evaluate patency rates and adverse effects for the different thrombolytic agents used.

Child, Preschool↗
PubMed2006

[The impact of some bad habits and environmental factors on the somatic status of male adolescents].

AIM: The aim of the study was to investigate whether some bad habits of sedentary lifestyle influence the occurrence of diagnoses in male adolescents, divided according to their environment into urban, rural and and island groups. PATIENTS AND METHODS: A total of 437 male adolescents underwent physical examination and functional diagnostic tests at Occupational Medicine Clinic in Rijeka, in order to evaluate their fitness for military service. The method of physical examination and anthropologic measurements was used. The results were analyzed by the Stat Soft, Statistics 6.0 software. Pearson chi-squared-test test and correlation matrices were used. RESULTS: The results showed obesity to be present in a relatively high percentage of subjects from urban area (10.94%) and rural area (13.19%), whereas asthenia was more pronounced in islanders (8.69%), yielding a statistically significant between-group difference (p<0.05). In contrast to asthenia, the islanders had the lowest percentage of flatfoot, with a significant difference from the two other groups (p<0.05). Refraction errors, primarily myopia, were not influenced by the place of residence. The incidence of myopia in all three groups was slightly over 20%. Contrary to our expectation, bronchial asthma was most common in the islanders (5.43%), however, there data could not be considered representative because of the rather big rate of migration from the inland to prevent relapses of respiratory diseases. The incidence of mild kyphoscoliosis ranged from 5.55% in the subjectss from rural settings up to 11.95% in the islanders, without a statistically significant between-group difference. DISCUSSION: It is difficult to identify the causes of differences in body weight among adolescents from urban, rural and island settings. It is not so easy to criticize the former for predominantly sedentary life, watching TV, video or Internet. Physical activity cannot be readily performed in towns because of the increasing presence of pollutants in the atmosphere. The prevalence of bronchial asthma was slightly higher than expected, which was explained by the permanent residence of atopics on the islands in order to prevent disease relapses. The lowest incidence of flatfoot among islanders was explained by their free lifestyle, barefoot walking along the rocky seaside, and high level of physical activity. Refraction errors including myopia as the leading diagnosis were equally present in the three groups, exceeding 20%. Besides heredity, the sight is influenced by intensified effects of ultraviolet radiation that causes changes of the eye structure. Also, neon signs and lights as well as too strong night streetlights lead to phototoxic vision damage in adolescents. Study results showed that male adolescents who lead physically inactive life should not to be blamed for the occurrence of the mentioned diagnoses. Like all of us they are daily affected by harmful pollutants that cause damage to the eyes, cardiovascular, respiratory and other organ systems. This study has helped identify the causes of the mentioned diseases in the group of male adolescents, emphasizing the role of occupational medicine. Specialists in occupational medicine should be involved in the monitoring of somatic and other parameters in adolescents from the early school age. In this period, it is still possible to reduce or and even prevent the occurrence of the mentioned diagnoses by examinations, education, exercises and diets. In this way, the candidates for military service would be healthier and fit.

Adolescent↗
PubMed1988

[Prognostic factors of malignant lymphomas].

As prognostic factors of malignant lymphomas, many factors such as histopathology, clinical stage, surface phenotype, primary site, and serum LDH are listed. But when we analyse the data according to the period accumulated for a long time, big differences in survivals are always observed. This fact means that the therapeutic factors become a very important prognostic factors, and the importance of other prognostic factors are influenced by the therapeutic factors. The main subjects in the treatment of lymphomas are the improvement of therapeutic results and the reduction of the intensity of treatment of the patients in whom the cure are expected in high probability. In these situation, statistical analysis of the prognostic factors include therapeutic factor will contribute strongly to the improvement of treatment results.

Age Factors↗
PubMed2005

Reconciliation and interpretation of Big Bend National Park particulate sulfur source apportionment: results from the Big Bend Regional Aerosol and Visibility Observational Study--part I.

The Big Bend Regional Aerosol and Visibility Observational (BRAVO) study was an intensive monitoring study from July through October 1999 followed by extensive assessments to determine the causes and sources of haze in Big Bend National Park, located in Southwestern Texas. Particulate sulfate compounds are the largest contributor of haze at Big Bend, and chemical transport models (CTMs) and receptor models were used to apportion the sulfate concentrations at Big Bend to North American source regions and the Carbón power plants, located 225 km southeast of Big Bend in Mexico. Initial source attribution methods had contributions that varied by a factor of > or =2. The evaluation and comparison of methods identified opposing biases between the CTMs and receptor models, indicating that the ensemble of results bounds the true source attribution results. The reconciliation of these differences led to the development of a hybrid receptor model merging the CTM results and air quality data, which allowed a nearly daily source apportionment of the sulfate at Big Bend during the BRAVO study. The best estimates from the reconciliation process resulted in sulfur dioxide (SO2) emissions from U.S. and Mexican sources contributing approximately 55% and 38%, respectively, of sulfate at Big Bend. The distribution among U.S. source regions was Texas, 16%; the Eastern United States, 30%; and the Western United States, 9%. The Carbón facilities contributed 19%, making them the largest single contributing facility. Sources in Mexico contributed to the sulfate at Big Bend on most days, whereas contributions from Texas and Eastern U.S. sources were episodic, with their largest contributions during Big Bend sulfate episodes. On the 20% of the days with the highest sulfate concentrations, U.S. and Mexican sources contributed approximately 71% and 26% of the sulfate, respectively. However, on the 20% of days with the lowest sulfate concentrations, Mexico contributed 48% compared with 40% for the United States.

Aerosols↗
PubMed2006

[Big Y chromosome not significantly influences outcomes of in vitro fertilization and embryo transfer].

OBJECTIVE: To evaluate the influence of big Y chromosome on the outcomes of in vitro fertilization and embryo transfer. METHODS: Data of 127 cycles of IVF/ICSI-ET, performed in our Reproductive Medicine Center from March 2001 to June 2003 were analyzed. The patients were divided into two groups according to the length of chromosome: Group A, 56 cycles with big Y chromosome RESULTS: No significant difference was observed in the quality of embryos and in the and Group B, 71 cycles with normal karyotype. rates of fertilization, cleavage, clinical pregnancy, implantation, miscarriage, ectopic pregnancy, dead infant delivery, malformation, CONCLUSION: Big Y chromosome has no significant influence on the baby boy delivery and baby girl delivery between the two groups. development of embryos and the outcome of pregnancy.

Chromosomes, Human, Y↗
PubMed1999

Cardiac endothelin and big endothelin in right-heart hypertrophy due to monocrotaline-induced pulmonary hypertension in rat.

OBJECTIVE: Recent observations suggest the existence of a myocardial endothelin (ET) system and its possible involvement in left-ventricular myocardial hypertrophy and failure. However, nothing is known about the role of myocardial ET in right-ventricular hypertrophy. METHODS: Rats (80-100 g) were given an intraperitoneal injection of saline (controls) or monocrotaline (50 mg/kg) resulting in pulmonary hypertension-induced myocardial hypertrophy (n = 11 in both groups). After 10 weeks, the animals were sacrificed and hearts perfused in vitro to determine levels of big ET-1 and ET-1 in coronary effluent, interstitial fluid and ventricular tissue homogenates; plasma levels were also determined. RESULTS: In monocrotaline-treated animals, weights of right ventricles were 1.5 and of right atria 1.8-fold higher than in controls (p < 0.05), indicating substantial right-ventricular hypertrophy as also evident from greatly increased myocardial production of atrial natriuretic peptide. Left-ventricular weights were not different. Release of big ET-1 in coronary effluent, and of ET-1 in coronary effluent and interstitial transudate were similar in control and hypertrophic hearts (p > 0.05). Disruption of endothelium with collagenase reduced release of both peptides close to zero, indicating endothelial (not myocardial) origin of the peptides. Levels of big ET-1 and ET-1 were similar in left ventricles of both experimental groups, but lower in right ventricles of hypertrophic than control hearts (p < 0.05), reflecting increased tissue mass rather than reduced peptide production. On the other hand, plasma levels of both peptides and of ANP were twofold and levels of angiotensin II 1.3-fold higher in rats with right-heart hypertrophy than in controls (p < 0.05 in each case). CONCLUSION: These data do not support a role for local cardiac ET-1 and/or big ET-1 in right-ventricular hypertrophy, but point to blood-borne endothelins as possible mediators.

Analysis of Variance↗
PubMed1991

Hunting income patterns among the Hadza: big game, common goods, foraging goals and the evolution of the human diet.

The assumption that large mammal hunting and scavenging are economically advantageous to hominid foragers is examined in the light of data collected among the Hadza of northern Tanzania. Hadza hunters disregard small prey in favour of larger forms (mean adult mass greater than or equal to 40 kg). Here we report experimental data showing that hunters would reduce their mean rates if they included small animals in the array they target. Still, daily variance in large animal hunting returns is high, and the risk of failure correspondingly great, significantly greater than that associated with small game hunting and trapping. Sharing large kills reduces the risk of meatless days for big game hunters, and obviates the problem of storing large amounts of meat. It may be unavoidable if large carcasses cannot be defended economically against the demands of other consumers. If so, then large prey are common goods. A hunter may gain no consumption advantage from his own big game acquisition efforts. We use Hadza data to model this 'collective action' problem, and find that an exclusive focus on large game with extensive sharing is not the optimal strategy for hunters concerned with maximizing their own chances of eating meat. Other explanations for the emergence and persistence of this practice must be considered.

Animals↗
PubMed2004

Upregulation of vascular ET(B) receptor gene expression after chronic ET(A) receptor blockade in prediabetic NOD mice.

In the aorta of prediabetic non-obese diabetic mice, a model of human type 1 diabetes, we investigated gene expression of the endothelin receptors and contractility to big endothelin-1 and endothelin-1 at the ages of 10 and 16 weeks. A subgroup of 10- week-old animals was treated with the endothelin ETA receptor antagonist LU461314 (30 mg/kg per day for 6 weeks). Blood glucose levels were normal in all animals. Real-time polymerase chain reaction analysis revealed that vascular ETB receptor expression was higher in 10-week-old non-obese diabetic (NOD) mice compared with controls. In 16-week-old NOD mice, but not in control mice, ETB receptor mRNA was twofold lower (P < 0.05 vs 10-week-old NOD mice). In all groups ETA receptor expression was unaffected by age or treatment. Contractions to big endothelin-1 and endothelin-1 were lower in 10-week-old NOD mice compared with controls. Treatment with LU461314 increased ETB receptor expression in 16-week-old NOD mice, but had no effect on vascular contractility. These data indicate that dysregulation of ETB receptor expression and a decreased contractile response to big endothelin-1 and endothelin-1 are present in the prediabetic state of a model of human type 1 diabetes. These alterations occur independent of glucose levels. Furthermore, ETA receptor blockade is effective in increasing ETB receptor gene expression, suggesting a potential role for endothelin ETA antagonists in the treatment of type 1 diabetes.

Age Factors↗
PubMed1985

Determination of reference intervals for 10 serum proteins measured by rate nephelometry, taking into consideration different sample groups and different distribution functions.

Reference intervals were established for 10 serum proteins (IgA, IgG, IgM, transferrin, haptoglobin, complement C3, complement C4, alpha 1-acid-glycoprotein, alpha 1-antitrypsin, alpha 2-macroglobulin) measured by rate nephelometry. The reference individuals - 200 blood donors - were divided into 5 subgroups: men aged 19-39 and 40-60 years, women aged 19-39 and 40-60 years and women aged 19-48 years using oral contraceptives. Where possible, two or more subgroups were combined to give reference sample groups. Criteria for this procedure are given. The reference limits of the sample groups were estimated by parametric methods. Assuming that for a specified serum protein the type of distribution is the same in each subgroup, the data were standardized with estimated group specific parameter values and combined into one big sample. This permitted an improved determination of the underlying type of distribution. As a possible form of distribution we also considered the normal distribution truncated on the left side at c greater than or equal to 0. In some cases, after determination of an optimal c, this unusual distribution fitted the data significantly better than the generally used normal or log-normal distribution.

Adult↗
PubMed2003

A voltage- and Ca2+-dependent big conductance K channel in cochlear spiral ligament fibrocytes.

Evidence is accruing that spiral ligament fibrocytes (SLFs) play an important role in cochlear K(+) homeostasis, but little direct physiological data is available to support this concept. Here we report the presence and characterization of a voltage- and Ca(2+)-dependent big-conductance K (BK) channel in type I SLFs cultured from the gerbil cochlea. A single-channel conductance of 298+/-5.6 pS (n=28) was measured under symmetrical K(+). Membrane potentials for half-maximal open probability (P(o)) were -67, -45 and 85 mV with cytosolic free-Ca(2+) levels of 0.7 mM, 10 microM and 1 microM, respectively (n=8-14). The Hill coefficient for Ca(2+) affinity was 1.9 at a membrane potential of 60 mV (n=6). The BK channel showed very low activity (P(o)=0.0019, n=5) under normal physiological conditions, suggesting a low resting intracellular free [Ca(2+)]. Pharmacological results fit well with the profile of classic BK channels. The estimated half-maximal inhibitory concentration and Hill coefficient for tetraethylammonium were 0.086+/-0.021 mM and 0.99, respectively (n=4-9). In whole cell recordings, the voltage-activated outward K current was inhibited 85.7+/-4.5% (n=6) by 0.1 microM iberiotoxin. A steady-state kinetic model with two open and two closed stages best described the BK gating process (tau(o1) 0.23+/-0.08 ms, tau(o2) 1.40+/-0.32 ms; tau(c1) 0.26+/-0.09 ms, tau(c2) 3.10+/-1.2 ms; n=11). RT-PCR analyses revealed a splice variant of the BK channel alpha subunit in cultured type I SLFs and freshly isolated spiral ligament tissues. The BK channel is likely to play a major role in regulating the membrane potential of type I SLFs, which may in turn influence K(+) recycling dynamics in the mammalian cochlea.

Animals↗
PubMed1989

Multicentre European trials: their design, execution and relevance.

Multicentre randomized clinical trials in Europe over the past decade have made a major contribution to the practice of cardiology and will increasingly do so when the Single Europe Act becomes a fact of life in 1992. The arguments for independent scientifically based research organizations and their role in the area of coronary artery disease are outlined. These include cost-benefit considerations, the science of clinical trials, data acquisition techniques and data management requirements. The role of the pharmaceutical industry in relation to the investigator-trialist is discussed. A critique of the current fashion 'Big is beautiful', with arguments against 'simplicity' and 'large size' and the need for 'credibility' is provided. Applicability of data from trials and their economic usefulness and validity in terms of sound pathophysiological hypotheses are also discussed and illustrated by using the CABRI trial as an example.

Angioplasty, Balloon, Coronary↗
PubMed2005

Definitive fossil evidence for the extant avian radiation in the Cretaceous.

Long-standing controversy surrounds the question of whether living bird lineages emerged after non-avian dinosaur extinction at the Cretaceous/Tertiary (K/T) boundary or whether these lineages coexisted with other dinosaurs and passed through this mass extinction event. Inferences from biogeography and molecular sequence data (but see ref. 10) project major avian lineages deep into the Cretaceous period, implying their 'mass survival' at the K/T boundary. By contrast, it has been argued that the fossil record refutes this hypothesis, placing a 'big bang' of avian radiation only after the end of the Cretaceous. However, other fossil data--fragmentary bones referred to extant bird lineages--have been considered inconclusive. These data have never been subjected to phylogenetic analysis. Here we identify a rare, partial skeleton from the Maastrichtian of Antarctica as the first Cretaceous fossil definitively placed within the extant bird radiation. Several phylogenetic analyses supported by independent histological data indicate that a new species, Vegavis iaai, is a part of Anseriformes (waterfowl) and is most closely related to Anatidae, which includes true ducks. A minimum of five divergences within Aves before the K/T boundary are inferred from the placement of Vegavis; at least duck, chicken and ratite bird relatives were coextant with non-avian dinosaurs.

Animals↗