bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reversibility of Atherosclerosis in Cholesterol-Fed Rabbits
Authors: BORTZ WALTER M. 
Published: June 2012

Previous studies have attempted to demonstrate the reversibility of rabbit atherosclerosis after discontinuance of cholesterol feeding or by other measures. These attempts have been largely unsuccessful. In all the studies, atherosclerosis was induced by cholesterol feeding for several months. At the end of these prolonged periods, the animals had advanced aortic lesions. The present study sought to determine whether a shorter exposure to an elevated blood cholesterol might produce lesions that were reversible.
Rabbits were fed cholesterol until their serum levels reached at least 1000 mg/100 ml; cholesterol feeding was then discontinued. Serum cholesterol values rapidly returned to normal levels. Some were killed at the time of discontinuance of the cholesterol diet and the others at periods up to 300 days thereafter. The aortas were removed and analyzed chemically for cholesterol content. The results demonstrate that cholesterol feeding of short duration produces a significant lesion whose cholesterol content may decrease markedly some weeks after the serum cholesterol has returned to normal levels.
Oxidative Phosphorylation in Mitochondria Isolated from Chronically Stressed Dog Hearts
Authors: STONER CLINTON D. , RESSALLAT MEHDI M. , SIRAK HOWARD D. 
Published: June 2012

Oxidative and phosphorylative activities were measured polarographically in mitochondria isolated from the right and left ventricles of normal and chronically stressed dog hearts. Chronic myocardial stress was produced experimentally by surgical procedures (combined tricuspid insufficiency and pulmonary stenosis, pulmonary insufficiency, aortic stenosis, aortic insufficiency, Potts's anastomosis) and by inducing thyrotoxicosis. Experimental stress periods ranged from 332 to 608 days. Some of the dogs had overt symptoms of congestive heart failure at the time they were killed.
Mitochondria isolated from the stressed hearts had abnormally high values for oxidative activity and respiratory control ratios when incubated in the presence of malate-pyruvate. In the presence of succinate, they had either normal or slightly elevated values for oxidative activity and respiratory control ratios. No differences were found between mitochondria from normal and stressed hearts with regard to the efficiency (ADP/O) of oxidative phosphorylation. Estimates of mitochondrial protein per gram of myocardial tissue indicated that the stressed hearts contained normal amounts of mitochondria. The results of this study suggest that the mitochondrial oxidative and phosphorylative capabilities of the chronically stressed myocardium are not impaired.
Refractory Period of the Dog's Ventricular Myocardium Following Sudden Changes in Frequency
Authors: JANSE M. J. , VAN DER STEEN A.B.M. , VAN DAM R. TH. , DURRER D. 
Published: June 2012

In exposed hearts of anesthetized dogs with total A-V block, a sudden increase or decrease in heart rate changes the duration of refractoriness immediately. A steady state is established only after a few hundred beats. The time course of shortening of the refractory period caused by an increase in driving rate ("on" effect) has the following characteristics. The first beat shortens the refractory period, as determined from strength-interval curves, about 30% of the total shortening; the second beat shortens it 10% more. After the second beat, the rate of change in the duration of the refractory period suddenly becomes slower. Alternation of the refractory period begins with a slightly prolonged refractory period of the third beat and then diminishes rapidly in about the following 10 beats. These changes are in phase throughout the ventricular myocardium.
Following sudden transition to a slower rhythm, the time course of lengthening of the refractory period ("off" effect) is opposite to the "on" effect: the alternation that occurs is less marked. Changes in the duration of the functional refractory period near the stimulus site are parallel to those in the threshold curves.
These results demonstrate a long persistence of the effect on myocardial refractoriness of a previous cardiac frequency.
Total and Regional Coronary Blood Flow Measured by Radioactive Microspheres in Conscious and Anesthetized Dogs
Authors: DOMENECH RAUL J. , HOFFMAN JULIEN I. , NOBLE MARK I. , SAUNDERS KENNETH B. , HENSON JAMES R. , SUBIJANTO SUJANTO 
Published: June 2012

Total and regional coronary blood flow were measured in dogs by left atrial injection of carbonized microspheres labeled with different radioactive isotopes (mean diameter 14 to 61µ). Simultaneously blood was collected at 20 ml/min from a catheter tied into a peripheral artery. The ratios of flow to radioactivity in myocardium and arterial blood should be equal if microspheres are well mixed in the aortic root and are distributed regionally in proportion to flow. This was proved in seven right heart by-pass experiments where coronary venous drainage was measured directly. Also, less than 0.1% of total myocardial radioactivity appeared in coronary venous blood, even with hypoxemia and small microspheres.
Total coronary flow in seven conscious dogs averaged 95 to 150 ml/min/100 g heart; and flow to the left ventricle was 111 to 169 ml/100 g. Although not validated independently, there was evidence that values for flow to each ventricle, the atria and the septum were correct.
The radioactivity per gram of left ventricular subendocardial muscle was 2.5 times that of subepicardial muscle using microspheres 51 to 61µ in diameter, but the ratios were 1.4 and 1.3 using microspheres of mean diameters 20 to 23µ and 14µ, respectively. It is unlikely that any of these microspheres measure blood flow to small portions of the ventricle.
Myosin Synthesis and Degradation during Development of Cardiac Hypertrophy in the Rabbit
Authors: MORKIN E. , KIMATA S. , SKILLMAN J. J. 
Published: June 2012

Metabolism of left ventricular myosin was studied in rabbits (2.7-3.2 kg) following banding of the ascending aorta (65% occlusion). In 26 rabbits the incorporation of amino acid into myosin was determined 2, 3, 4, 9, and 15 days after either stenosis or sham operation by injecting
3
H-lysine (0.5	mc/kg) 4 hours before the animals were killed. In 32 rabbits the same dose of
3
H-lysine was injected 24 hours before surgery, and disappearance of isotope from myosin was measured by killing the rabbits after 3, 5, 7, 10, or 16 days. Specific radioactivity of free lysine, myosin, and total proteins was determined in left ventricular samples from each animal. The experimental results indicate that: (1) left ventricular peak systolic pressure increased from 97 to 163 mm Hg; (2) the ratio of left ventricular weight to body weight increased about 16% (3) disappearance of free
3
H-lysine was similar in rabbits with aortic stenosis and those with sham operations; (4) after the second day myosin synthesis was greater in rabbits with aortic coarctations, reaching a maximum increase of 117% on the tenth day; (5) synthesis of left ventricular total proteins also reached a maximum of about 56% on the tenth day; (6) the decrease in specific radioactivity of myosin in rabbits with aortic coarctation was slower than it was in sham-operated animals. The experimental results were analyzed by a computerized simulation of myosin metabolism which allowed the rate constant for myosin degradation to be calculated on successive days after coarctation. The best fit to the observed changes in myosin content was obtained when degradation was increased with the increase in synthesis; when degradation was assumed to be unchanged from sham-operated animals or was decreased, myosin content was overestimated. Moreover, these calculations showed that decay in specific radioactivity of labeled myosin was affected very little even by a large (hundredfold) decrease in degradation. It is concluded that the increased myosin content during development of cardiac hypertrophy is primarily a consequence of increased synthesis.
Vascular Muscle Reactivity
Authors: DODD W. ALAN , DANIEL EDWIN E. 
Published: June 2012

Arterial contractility was investigated, using spiral and ring sections of dog, cat, rabbit, rat, and human vessels. Epinephrine produced contractions of all arterial tissue tested. Histamine invariably produced contractions. The phenomenon of variable sensitivity of arterial tissue to histamine was again demonstrated. Acetylcholine caused contractions of rabbit, cat, and rat aortas, but no contraction of the dog aorta, or dog and human femoral arteries was observed. Pitressin produced contraction of the rat aorta, and dog and human femoral arteries, but not of rabbit, dog or cat aortas.
Using dog vessels, a difference in activity was observed between the aorta and the femoral artery. Greater reactivity in terms of maximum rate of tension increase and tension developed was seen in the smaller systemic arteries. A pharmacologic difference with respect to the action of pitressin was discovered between the aorta and the smaller arteries. Thus, general evidence is presented suggesting that data obtained in 1 species of animal on 1 type of tissue cannot be transferred without specific proof of its validity to data obtained in other species, or even in closely related tissues of the same species.
An apparent antagonistic effect of pitressin on the pressor action of epinephrine was detected.
Mechanism of S-T Segment Alteration During Acute Myocardial Injury
Authors: SAMSON WERNER E. , SCHER ALLEN M. 
Published: June 2012

Electrocardiograms recorded with a direct-coupled amplifier and recordings of intramyocardial and intracellular potentials were used to determine the nature of the S-T segment shift after myocardial injury. Immediately after coronary artery ligation in the dog, both true S-T and T-Q changes are produced. Lack of responsiveness to the activation wave in the injured area does not account for the initial change in the S-T segment. Changes in the intracellular action potential can be correlated with the electrocardiographic changes. Immediately after injury, cells in the injured area usually repolarize more rapidly than normal cells and this change is significantly correlated with S-T segment shifts. A decrease in resting potential, generally oc	curring later than the action potential changes, is similarly correlated with T-Q segment changes.
Vasomotor Responses in the Human Arm During Leg Exercise
Authors: BLAIR DAVID A. , GLOVER WALTER E. , RODDIE JAN C. 
Published: June 2012

Blood flow was measured in the hands and forearms of recumbent subjects by venous occlusion plethysmography during leg exer cise on a bicycle ergometer. In three highly practiced subjects, exercise resulted in a small fall in forearm flow and a moderate rise in arterial pressure. Resistance to blood flow was therefore considerably increased. Blocking the vasomotor fibers to forearm skin did not affect this, but blocking the deep nerves to the muscle vessels prevented the increase in vascular resistance during exer cise. Treating the forearm with bretyliurn tosylate had the same effect as deep nerve block. It was concluded that vasoconstrictor tone in muscle is increased during exercise.
Since treating the forearm with atropine did not affect the normal response, it was concluded that activation of vasodilator fibers to muscle is not an integral part of the gen eral vasomotor response to exercise. Evidence was also found that the vasodilator outflow to a specific muscle group is not specifically activated when the muscle group in question is exercised.
During fairly heavy exercise, vasodilatation occurred in both hand and forearm skin. In the hand this was preceded by vasoconstric tion. Evidence was found that the vasodila tation in the hand was due to release of vaso constrictor tone, whereas that in the forearm was mediated through vasodilator fibers. It is likely that the increase in heat production during exercise was responsible for the reflex vasodilatation in skin.
Electrocardiogram of the Diving Seal
Authors: MURDAUGH HERSCHEL V. , SEABURY JAMES C. , MITCHELL WILLIAM L. 
Published: June 2012

During the normal dive, the seal has a reflex bradycardia that is not accompanied by inversion of P waves or T waves or by atrial or ventricular arrhythmias, although the seal does have an occasional block of conduction across the A-V node during normal diving. The reflex bradycardia during the dive appears to be mediated through vagal stimulus.
The electrocardiograms of the seal during voluntary diving and during forced submersion with struggle are different.
Wind-Driven Variability of the Subtropical North Pacific Ocean
Authors: Giglio Donata , Roemmich Dean , Gille Sarah T. 
Published: June 2012

Abstract
The Argo array provides a unique dataset to explore variability of the subsurface ocean interior. This study considers the subtropical North Pacific Ocean during the period from 2004 to 2011, when Argo coverage has been relatively complete in time and space. Two distinct patterns of Argo dynamic height transport function () are observed: in 2004/05, the gyre is stronger, and in 2008/09 it is weaker. The orientation of the subtropical gyre also shifts over time: the predominantly zonal major axis shifts to a more northwest–southeast orientation in 2004/05 and to a more southwest–northeast orientation in 2008/09.
The limited temporal range of the Argo observations does not allow analysis of the correlation of ocean transport and wind forcing in the basin for the multiyear time scale (6–8-yr period) typical of the dominant gyre patterns. The meridional geostrophic transport anomaly between 180° and 150°E is computed both from Argo data (0–2000 db) and from the Sverdrup relation (using reanalysis winds): similarities are observed in a latitude–time plane, consistent with local forcing playing an important role. A forcing contribution from the eastern subtropics will also reach the region of interest, but on a longer time scale, and it is not analyzed in this study.
Compared with the 8-yr Argo record, the longer 19-yr time series of satellite altimetry shows a similar but somewhat modified pattern of variability. A longer Argo record will be needed to observe the decadal-scale fluctuations, to separate interannual and decadal signals, and to ensure statistical confidence in relating the wind forcing and the oceanic response.
Neither “Scientific” nor “Colonialist”
Authors: Giraudo Laura 
Published: June 2012

Efforts to develop a shared, Pan-American indigenista plan, beginning with the creation of the Inter-American Indian Institute (Instituto Indigenista Interamericano—III) in 1940, had to overcome a series of problems, especially financial and political ones. Obtaining support from the Mexican government and, above all, from the United States allowed the III to launch some important projects, but it greatly limited the extent to which it could promote a truly Pan-American program. The historical record suggests that, in the end, the radical and ambitious indigenista plan was hard to realize. Moreover, this history was much more uncertain, mixed, and ambivalent than had been expected and challenged long-held assumptions about indigenismo and its role. Con la creación del Instituto Indigenista Interamericano (III), en 1940, se pretendía elaborar un programa indigenista panamericano, pero había que superar una serie de problemas, sobre todo financieros y políticos. Gracias al apoyo inicial del gobierno mexicano y de los Estados Unidos, el III puso en marcha algunos proyectos importantes, pero ese mismo apoyo limitó, en buena medida, la posibilidad de promover un programa indigenista que fuera realmente panamericano. La evidencia histórica sugiere, de hecho, que este programa indigenista, ambicioso y radical, era de difícil realización. Además, su historia se revela mucho más incierta, incoherente y ambivalente de lo esperado, desafiando muchas de las ideas consolidadas sobre el indigenismo y su papel.
Improving the Detection of Fungi in Eosinophilic Mucin
Authors: Guo Canting , Ghadersohi Saied , Kephart Gail M. , Laine Roger A. , Sherris David A. , Kita Hirohita , Ponikau Jens U. 
Published: June 2012

ObjectiveTo investigate the improvement in histologic detection of fungi with Gomori methenamine silver (GMS) stain by trypsin predigestion in the mucus of patients with chronic rhinosinusitis (CRS).Study DesignProspective, single group, descriptive analysis.SettingMulti‐institutional.Subjects and MethodsThirty‐four sinus specimens from 12 surgical patients with CRS were stained with hematoxylin and eosin, GMS stain, GMS with trypsin digestion, immunofluorescence stains for chitinase, and anti‐Alternaria. All patients received skin testing, total IgE serology, and radioallergosorbent tests (RAST) for 23 fungal‐specific IgE antibodies.ResultsThe conventional GMS stain detected fungi in only 9 of 34 (27%) specimens. Predigesting the specimen with trypsin dramatically improved the visualization of fungi (31/34, 91%). The chitinase immunofluorescence visualized fungi in 32 of 34 (94%), and anti‐Alternaria visualized 33 of 34 specimens (97%). Only 8 of 12 (75%) patients had detectable allergies.ConclusionsThis report describes a simple modification of the conventional GMS stain that can significantly improve the visualization of fungi on histology and explains the lack of detection in previous studies. These novel, more sensitive histologic methods reveal the presence of fungi within the eosinophilic mucin in allergic and also nonallergic CRS patients, further questioning a crucial role of an IgE‐mediated pathophysiology.
Quantitative classification of pediatric swallowing through accelerometry
Authors: Celeste Merey , Azadeh Kushki , Sejdić Ervin , Berall Glenn , Chau Tom 
Published: June 2012

Abstract

Background
Dysphagia or swallowing disorder negatively impacts a child’s health and development. The gold standard of dysphagia detection is videofluoroscopy which exposes the child to ionizing radiation, and requires specialized clinical expertise and expensive institutionally-based equipment, precluding day-to-day and repeated assessment of fluctuating swallowing function. Swallowing accelerometry is the non-invasive measurement of cervical vibrations during swallowing and may provide a portable and cost-effective bedside alternative. In particular, dual-axis swallowing accelerometry has demonstrated screening potential in older persons with neurogenic dysphagia, but the technique has not been evaluated in the pediatric population.

Methods
In this study, dual-axis accelerometric signals were collected simultaneous to videofluoroscopic records from 29 pediatric participants (age 6.8 ± 4.8 years; 20 males) previously diagnosed with neurogenic dysphagia. Participants swallowed 3-5 sips of barium-coated boluses of different consistencies (normally, from thick puree to thin liquid) by spoon or bottle. Videofluoroscopic records were reviewed retrospectively by a clinical expert to extract swallow timings and ratings. The dual-axis acceleration signals corresponding to each identified swallow were pre-processed, segmented and trimmed prior to feature extraction from time, frequency, time-frequency and information theoretic domains. Feature space dimensionality was reduced via principal components.

Results
Using 8-fold cross-validation, 16-17 dimensions and a support vector machine classifier with an RBF kernel, an adjusted accuracy of 89.6% ± 0.9 was achieved for the discrimination between swallows with and with out airway entry.

Conclusions
Our results suggest that dual-axis accelerometry has merit in the non-invasive detection of unsafe swallows in children and deserves further consideration as a pediatric medical device.
Overall Survival Benefit With Lapatinib in Combination With Trastuzumab for Patients With Human Epidermal Growth Factor Receptor 2–Positive Metastatic Breast Cancer: Final Results From the EGF104900 Study
Authors: Blackwell Kimberly L. , Burstein Harold J. , Storniolo Anna Maria , Rugo Hope S. , Sledge George , Aktan Gursel , Ellis Catherine , Florance Allison , Vukelja Svetislava , Bischoff Joachim , Baselga José , O'Shaughnessy Joyce 
Published: June 2012

Purpose Phase III EGF104900 data demonstrated that lapatinib plus trastuzumab significantly improved progression-free survival (PFS) and clinical benefit rate versus lapatinib monotherapy, offering a chemotherapy-free option for patients with heavily pretreated human epidermal growth factor receptor 2 (HER2) –positive metastatic breast cancer (MBC). Final planned overall survival (OS) analysis from EGF104900 is reported here. Patients and Methods Patients with HER2-positive MBC whose disease progressed during prior trastuzumab-based therapies were randomly assigned to receive lapatinib monotherapy or lapatinib in combination with trastuzumab. OS and updated PFS data are presented using Kaplan-Meier curves and log-rank tests stratified for hormone receptor and visceral disease status. Subgroup analyses were conducted to identify characteristics of patients deriving the greatest clinical benefit. Results In this updated final analysis of all patients randomly assigned with strata (n = 291), lapatinib plus trastuzumab continued to show superiority to lapatinib monotherapy in PFS (hazard ratio [HR], 0.74; 95% CI, 0.58 to 0.94; P = .011) and offered significant OS benefit (HR, 0.74; 95% CI, 0.57 to 0.97; P = .026). Improvements in absolute OS rates were 10% at 6 months and 15% at 12 months in the combination arm compared with the monotherapy arm. Multiple baseline factors, including Eastern Cooperative Oncology Group performance status of 0, nonvisceral disease, < three metastatic sites, and less time from initial diagnosis until random assignment, were associated with improved OS. Incidence of adverse events was consistent with previously reported rates. Conclusion These data demonstrated a significant 4.5-month median OS advantage with the lapatinib and trastuzumab combination and support dual HER2 blockade in patients with heavily pretreated HER2-positive MBC.
Change in Tumor Size by RECIST Correlates Linearly With Overall Survival in Phase I Oncology Studies
Authors: Jain Rajul K. , Lee J. Jack , Ng Chaan , Hong David , Gong Jing , Naing Aung , Wheler Jennifer , Kurzrock Razelle 
Published: June 2012

Purpose RECIST is used to quantify tumor changes during exposure to anticancer agents. Responses are categorized as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). Clinical trials dictate a patient's management options based on the category into which his or her response falls. However, the association between response and survival is not well studied in the early trial setting. Patients and Methods To study the correlation between response as quantified by RECIST and overall survival (OS, the gold-standard survival outcome), we analyzed 570 participants of 24 phase I trials conducted between October 2004 and May 2009, of whom 468 had quantifiable changes in tumor size. Analyses of Kaplan-Meier estimates of OS by response and null Martingale residuals of Cox models were the primary outcome measures. All analyses are landmark analyses. Results Kaplan-Meier analyses revealed strong associations between change in tumor size by RECIST and survival (P = 4.5 × 10−6 to < 1 × 10−8). The relationship was found to be near-linear (R2 = 0.75 to 0.92) and confirmed by the residual analyses. No clear inflection points were found to exist in the relationship between tumor size changes and survival. Conclusion RECIST quantification of response correlates with survival, validating RECIST's use in phase I trials. However, the lack of apparent boundary values in the relationship between change in tumor size and OS demonstrates the arbitrary nature of the CR/PR/SD/PD categories and questions emphasis placed on this categorization scheme. Describing tumor responses as a continuous variable may be more informative than reporting categoric responses when evaluating novel anticancer therapies.