Myocardial deformation imaging by 2D speckle tracking echocardiography for assessment of diastolic dysfunction in murine cardiopathology.

Diastolic dysfunction is increasingly identified as a key, early onset subclinical condition characterizing cardiopathologies of rising prevalence, including diabetic heart disease and heart failure with preserved ejection fraction (HFpEF). Diastolic dysfunction characterization has important prognostic value in management of disease outcomes. Validated tools for in vivo monitoring of diastolic function in rodent models of diabetes are required for progress in pre-clinical cardiology studies. 2D speckle tracking echocardiography has emerged as a powerful tool for evaluating cardiac wall deformation throughout the cardiac cycle. The aim of this study was to examine the applicability of 2D speckle tracking echocardiography for comprehensive global and regional assessment of diastolic function in a pre-clinical murine model of cardio-metabolic disease. Type 2 diabetes (T2D) was induced in C57Bl/6 male mice using a high fat high sugar dietary intervention for 20 weeks. Significant impairment in left ventricle peak diastolic strain rate was evident in longitudinal, radial and circumferential planes in T2D mice. Peak diastolic velocity was similarly impaired in the longitudinal and radial planes. Regional analysis of longitudinal peak diastolic strain rate revealed that the anterior free left ventricular wall is particularly susceptible to T2D-induced diastolic dysfunction. These findings provide a significant advance on characterization of diastolic dysfunction in a pre-clinical mouse model of cardiopathology and offer a comprehensive suite of benchmark values for future pre-clinical cardiology studies.

Effective Expansion: Balance between Shrinkage and Hygroscopic Expansion.

The purpose of this study was to investigate the relationship between hygroscopic expansion and polymerization shrinkage for compensation of polymerization shrinkage stresses in a restored tooth. One resin-modified glass-ionomer (RMGI) (Ketac Nano, 3M ESPE), 2 compomers (Dyract, Dentsply; Compoglass, Ivoclar), and a universal resin-based composite (Esthet•X HD, Dentsply) were tested. Volumetric change after polymerization ("total shrinkage") and during 4 wk of water storage at 37°C was measured using an optical method (n= 10). Post-gel shrinkage was measured during polymerization using a strain gauge method (n= 10). Extracted human molars with large mesio-occluso-distal slot preparations were restored with the tested restorative materials. Tooth surfaces at baseline (preparation), after restoration, and during 4 wk of 37°C water storage were scanned with an optical scanner to determine cuspal flexure (n= 8). Occlusal interface integrity was measured using dye penetration. Data were analyzed using analysis of variance and post hoc tests (significance level 0.05). All tested materials shrunk after polymerization. RMGI had the highest total shrinkage (4.65%) but lowest post-gel shrinkage (0.35%). Shrinkage values dropped significantly during storage in water but had not completely compensated polymerization shrinkage after 4 wk. All restored teeth initially exhibited inward (negative) cuspal flexure due to polymerization shrinkage. Cuspal flexure with the RMGI restoration was significantly less (-6.4 µm) than with the other materials (-12.1 to -14.1 µm). After 1 d, cuspal flexure reversed to +5.0 µm cuspal expansion with the RMGI and increased to +9.3 µm at 4 wk. After 4 wk, hygroscopic expansion compensated cuspal flexure in a compomer (Compoglass) and reduced flexure with Dyract and resin-based composite. Marginal integrity (93.7% intact restoration wall) was best for the Compoglass restorations and lowest (73.1%) for the RMGI restorations. Hygroscopic expansion was more effective in compensating shrinkage stress than would be assumed based on total shrinkage, because only post-gel shrinkage needed compensation. Effective expansion is therefore hygroscopic expansion minus post-gel shrinkage.

Excision of the nifD element in the heterocystous cyanobacteria.

Heterocyst differentiation in cyanobacteria is accompanied by developmentally regulated DNA rearrangements that occur within the nifD, fdxN, and hupL genes. These genetic elements are excised from the genome by site-specific recombination during the latter stages of differentiation. The nifD element is excised by the recombinase, XisA, located within the element. Our objective was to examine the XisA-mediated excision of the nifD element. To accomplish this, we observed the ability of XisA to excise substrate plasmids that contained the flanking regions of the nifD element in an E. coli host. Using PCR directed mutagenesis, nucleotides in the nifD element flanking regions in substrate plasmids were altered and the effect on recombination was determined. Results indicate that only certain nucleotides within and surrounding the direct repeats are involved in excision. In some nucleotide positions, the presence of a purine versus a pyrimidine greatly affected recombination. Our results also indicated that the site of excision and branch migration occurs in a 6 bp region within the direct repeats.

Molecular phylogeny and biogeography of tribe anthemideae (Asteraceae), based on chloroplast gene ndhF.

Anthemideae (Asteraceae) is primarily a north temperate, Old World tribe of 109 genera and approximately 1740 species. We sequenced a 1200-bp portion of chloroplast gene ndhF for representative genera and subtribes and constructed a phylogeny for the tribe. There is support for monophyly of subtribes Chrysantheminae and Gonosperminae and for portions of some subtribes. However, our molecular phylogeny differs significantly from traditional classifications and from previously published morphological phylogenies of the tribe. Many South African genera from several different subtribes form a basal grade, indicating multiple, relictual lineages. Eurasian genera form a recently derived clade that includes the Mediterranean genera of the Iberian Peninsula and North Africa. There is little resolution or support for the placement of eastern Asian genera. Apparently, the tribe originated in the Southern Hemisphere, presumably in Africa, with the Eurasian and Mediterranean members being derived from a common ancestor.

The experiences of postpartum hospital stay and returning home among Thai mothers in Australia.

OBJECTIVE: To describe the experience of postpartum care among Thai women in Melbourne, Australia. DESIGN: Ethnographic interviews and participant observation with women in relation to postpartum care and practices. SETTING: Melbourne Metropolitan Area, Victoria, Australia. PARTICIPANTS: 26 Thai born women who gave birth in Australia. FINDINGS: The Thai women had varying views about the length of time they should spend in hospital and the care they received. Ten of the twelve women who had had a caesarean birth stayed in hospital for six or more days, consistent with the hospital practice. However, most of those who had had a vaginal delivery opted to go home earlier than the standard hospital practice of four days stay. This was because they were unhappy about specific hospital practices, the hospital environment, or because there are several Thai confinement customs, which, traditionally, a new mother must observe in order to maintain good health and avoid future ill health and which they were not able to follow in hospital. Nevertheless, most women were satisfied with their postpartum care. Most women were aware of the Thai cultural beliefs and practices. However, they showed varying ways of coping with the hospital environment in relation to their varying social situations. IMPLICATIONS FOR PRACTICE: Thai women are diverse in their needs, perceptions and experience of postpartum care. Therefore, it is appropriate neither to stereotype all Thai women as requiring to follow traditional confinement practices nor to require them to adjust to standard hospital practices. Rather an environment of caring concern whereby each woman's individual needs can be solicited, understood and, where possible, attended to as required. The challenge is in achieving this.

Phylogenetic analysis of Artemisia section Tridentatae (Asteraceae) based on sequences from the internal transcribed spacers (ITS) of nuclear ribosomal DNA.

Artemisia sect. Tridentatae is composed of 11 species of xerophytic shrubs, which dominate much of western North America. Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were used to construct a phylogeny, examine circumscription of the section, resolve interspecific relationships, and test competing hypotheses on the origin of the section. The data support the monophyly of sect. Tridentatae, with the exclusion of A. bigelovii and A. palmeri-two historically, anomolous species. However, the ITS data provide insufficient variation to fully resolve interspecific relationships or to support major lineages within the Tridentata clade. Nuclear and chloroplast DNA phylogenies are discordant, which may be a result of interspecific gene flow and subsequent chloroplast capture, particularly related to the placement of A. filifolia and A. californica, in addition to A. bigelovii. Furthermore, the ITS data are in conflict with cpDNA data, providing equivocal evidence for competing hypotheses on the Old World vs. New World origin for the section and do not provide support for definitive subgeneric placement.

Radiation exposure during cardiology fellowship training.

We report catheterization laboratory personnel dose per case during parallel use of two laboratories from different manufacturers. Initially, four working positions were monitored. Review of the data from the first 140 cases showed a wide range of dose per case. Measurements were then limited to diagnostic coronary angiography cases in which a cardiology fellow was the primary operator. On a per case basis, the dose was higher when a fellow was in the laboratory with pulsed progressive fluoroscopy or was in fellowship year one. The increased dose for first year fellows was more related to increased fluoroscopy time than to cine angiography time. This study emphasizes the importance of close supervision of cardiology fellows early in their training to limit dose to patients and personnel, and it underlines the importance of each catheterization laboratory routinely having the actual personnel dose per case measured.

Usefulness of positive troponin-T and negative creatine kinase levels in identifying high-risk patients with unstable angina pectoris.

Troponin-T was measured in patients with chest pain and negative creatine phosphokinase-MB isoenzymes. Patients with elevated troponin-T had a significantly greater risk of cardiac events over the next 6 months than patients with normal troponin-T.

Early and late quantitative angiographic results of vein graft lesions treated by excimer laser with adjunctive balloon angioplasty.

BACKGROUND: Percutaneous excimer laser coronary angioplasty (PELCA) has been approved for treatment of diseased saphenous vein bypass grafts. However, detailed and complete quantitative angiographic analysis of immediate procedural and late follow-up results has not been performed. METHODS AND RESULTS: PELCA using the CVX-300 excimer laser system was performed in 125 bypass lesions (mean graft age, 96 +/- 53 months; range, 2 to 240 months) in 106 consecutive patients at eight centers. Quantitative analyses of the procedural and follow-up angiograms were done with the Cardiac Measurement System. Stand-alone PELCA was done in 21 lesions (17%). Lesions were located at the ostium (20%), body (67%), or distal anastomosis (13%). The graft reference diameter was 3.26 +/- 0.79 mm (mean +/- SD). Minimal lumen diameter increased from 1.09 +/- 0.52 mm before treatment to 1.61 +/- 0.69 mm after laser and 2.18 +/- 0.63 mm after adjunctive balloon dilation (P < .001) but had declined at follow-up to 1.40 +/- 1.17 mm. Dissections were evident in 45% of lesions after laser treatment (types A and B, 27%; types C through F, 18%), including 7% occlusions. Angiographic success (< or = 50% diameter stenosis [% DS]) was 54% after laser and 91% after adjunctive PTCA, with an overall clinical success rate of 89%. In-hospital complications were death, 0.9%; myocardial infarction (Q-wave and non-Q-wave), 4.5%; and bypass surgery, 0.9%. Independent predictors of % DS after laser were reference diameter, lesion length, and minimal lumen diameter before laser. At angiographic follow-up in 83% of eligible patients, the restenosis rate per lesion (DS > 50%) was 52%, including 23 occlusions (24%). The only independent predictor of increased % DS at follow-up was lesion symmetry. Logistic regression indicated that smaller reference diameter was an independent predictor of late occlusion. Overall 1-year mortality was 8.6%. Actuarial event-free survival (freedom from death, myocardial infarction, bypass surgery, or target vessel percutaneous transluminal coronary angioplasty) was 48.2% at 1 year. CONCLUSIONS: Excimer laser angioplasty with adjunctive balloon angioplasty can be safely and successfully performed in diseased, old saphenous vein bypass graft lesions considered at high risk for reintervention. The extent of laser ablation remains limited by the diameter and effectiveness of the catheters. Late restenosis and, in particular, total occlusion mitigate the early benefits of the procedure. Other approaches such as the routine use of additional anticoagulation (eg, warfarin) should be considered to reduce the risk of late occlusions and restenosis after laser angioplasty of bypass grafts.

High-finesse interferometers.

A detailed plan for the construction and use of a nonconfocal cavity used as a high-finesse interferometer is presented. The interferometer has a free spectral range of l5 GHz, with a finesse of over 30,000.

Excimer laser coronary angioplasty for failed PTCA.

Specific indications for excimer laser coronary angioplasty (ELCA) are yet undefined. We report two specific applications of ELCA when percutaneous transluminal coronary angioplasty (PTCA) failed: (1) to facilitate balloon crossing a long rigid stenosis that could not be crossed after the lesion was wired, and (2) to overcome prominent elastic recoil of the stenosis after PTCA.

PTCA of gastroepiploic bypass.

A technique for percutaneous transluminal coronary angioplasty (PTCA) of gastroepiploic bypass is described using standard PTCA devices. Severe spasm of gastroepiploic bypass occurred. Modification of guide catheter position is suggested to avoid inducing gastroepiploic bypass spasm.

Gas exchange responses of two Eucalyptus species to salinity and waterlogging.

The effects of salinity and waterlogging on stomatal conductance, net photosynthesis and transpiration of 3-month-old Eucalyptus camaldulensis Dehnh. and Eucalyptus lesouefii Maiden seedlings were studied under greenhouse conditions. Under non-saline conditions, waterlogging induced stomatal closure in both species. However, the stomata of E. camaldulensis reopened after five weeks, when adventitious roots were produced. Relative to that of controls, height growth of waterlogged seedlings was greater in E. camaldulensis than in E. lesouefii, as were rates of photosynthesis and transpiration. In a freely drained medium, high salinity reduced rates of seedling height growth and photosynthesis, relative to those in controls, less in E. lesouefii than in E. camaldulensis. In both species, height growth, stomatal conductance and photosynthetic rate were lowest under conditions of saline waterlogging.

Snare loop technique for removal of broken steerable PTCA wire.

Two cases are described of percutaneous removal of trapped, broken steerable PTCA guidewire. One case described breakage of a guidewire inside the ascending aorta leaving a free end, which is retrieved using the snare loop technique. The second case described retrieval of an intact yet unwound wire through the guiding catheter using a snare loop wire.

Observer variation in the angiocardiographic diagnosis of mitral valve prolapse.

The purpose of this study was to assess the reliability of the angiocardiographic diagnosis of mitral valve prolapse by measuring agreement between observers using defined diagnostic criteria. Sixty high-quality left ventriculograms, selected to include many that showed possible mitral valve prolapse, were reviewed by three angiocardiographers. Disagreement between observers as to positivity occurred in 26 percent and 30 percent of the cases on two reviews, and disagreement as to specific scallop involvement occurred in 68 percent and 78 percent of the cases. A specific observer agreed with himself in interpretation of positive 78 to 82 percent of the time and in the interpretation of specific scallop involvement 55 to 90 percent of the time. These results indicate that in the absence of generally agreed upon quantitative angiocardiographic criteria for the diagnosis of mitral valve prolapse, there is considerable variability among observers in the interpretation of mitral valve prolapse by angiocardiographic studies.

Cyanosis in a patient with combined ostium primum and secundum atial septal defects and anomalous inferior vena cava with azygos continuation. Case report and surgical considerations.

A case is described of combined ostium primum and ostium secundum atrial septal defects and azygos connection of the inferior vena cava plus cyanosis. Emphasis is made to recognize the functional mechanism of cyanosis and to demonstrate the anatomic site of hepatic venous drainage so that an appropriate corrective operative procedure can be planned. A gratifying result was achieved in this case after closure of the atrial septal defects.

True and false aneurysms of the left ventricle following myocardial infarction.

Anterolateral myocardial infarction resulted in the formation of both true and false aneurysms in a 75 year old man in whom severe congestive heart failure subsequently developed as the false aneurysm became progressively larger. Left ventriculography detected and quantified both aneurysms, and demonstrated reasonable function of the remaining volume-overloaded left ventricle. Resection of both aneurysms was accomplished with marked relief of symptoms. The literature on false aneurysm is reviewed, and the dilemma posed by the need to recognize false aneurysms before they become symptomatic or rupture is discussed.

Left ventricular aneurysm. Preoperative hemodynamics, chamber volume, and results of aneurysmectomy.

Angiocardiographic characteristics of the residual contracting left ventricle (LV) have been examined in 16 patients with anterolateral ventricular aneurysms (VA). In each patient a contractile section (CS) of the LV was clearly demarcated from the remaining aneurysmal section (AS). Using a double hemispheroid model, volumes of CS and AS were separately estimated by a modified area-length method. The volume of CS plus AS agreed closely with the volume of total LV estimated by the conventional area-length method. End-diastolic volume (EDV) of total LV ranged from 79 to 312ml/72. Aneurysmal section volume ranged from 8 to 264 ml/m2. End-diastolic volume of the contractile section ranged from 52 to 159 ml/m2 (mean, 100+/-8 (se); normal, 78+/-6). Contractile section ejection fraction (EF) showed a wide range, from 15% to 79% (mean 40%+/-17% SD). Nine patients underwent resection of VA. Three of six operated patients with CS EF less than 44% died; no survivor in this group has improved by more than one functional class (New York Heart Association classification). Three operated patients had CS EF greater than 45%; all survived and are improved, two having moved from class IV to class I. These data suggest that the EF of the contracting residual LV may be an important predictor of the outcome of resection of VA.