Modifications of a conserved regulatory network involving INDEHISCENT controls multiple aspects of reproductive tissue development in Arabidopsis.

Disrupting pollen tube growth and fertilization in Arabidopsis plants leads to reduced seed set and silique size, providing a powerful genetic system with which to identify genes with important roles in plant fertility. A transgenic Arabidopsis line with reduced pollen tube growth, seed set and silique growth was used as the progenitor in a genetic screen to isolate suppressors with increased seed set and silique size. This screen generated a new allele of INDEHISCENT (IND), a gene originally identified by its role in valve margin development and silique dehiscence (pod shatter). IND forms part of a regulatory network that involves several other transcriptional regulators and involves the plant hormones GA and auxin. Using GA and auxin mutants that alter various aspects of reproductive development, we have identified novel roles for IND, its paralogue HECATE3, and the MADS box proteins SHATTERPROOF1/2 in flower and fruit development. These results suggest that modified forms of the regulatory network originally described for the Arabidopsis valve margin, which include these genes and/or their recently evolved paralogs, function in multiple components of GA/auxin-regulated reproductive development.

Hormonal changes during non-climacteric ripening in strawberry.

In contrast to climacteric fruits, where ethylene is known to be pivotal, the regulation of ripening in non-climacteric fruits is not well understood. In the non-climacteric strawberry (Fragaria anannassa), auxin and abscisic acid (ABA) are thought to be important, but the roles of other hormones suggested to be involved in fruit development and ripening are not clear. Here changes in the levels of indole-3-acetic acid (IAA), ABA, GA1, and castasterone from anthesis to fully ripened fruit are reported. The levels of IAA and GA1 rise early in fruit development before dropping to low levels prior to colour accumulation. Castasterone levels are highest at anthesis and drop to very low levels well before ripening commences, suggesting that brassinosteroids do not play an important role in ripening in strawberry. ABA levels are low at anthesis and gradually rise through development and ripening. The synthetic auxin, 1-naphthaleneacetic acid (NAA), can delay ripening, but the application of GA3, the gibberellin biosythesis inhibitor paclobutrazol, and ABA had no significant effect. IAA and ABA levels are higher in the developing achenes than in the receptacle tissue and may be important for receptacle enlargement and ripening, and seed maturation, respectively. Contrary to a recent report, the biologically active GA4 was not detected. The pattern of changes in the levels of the hormones are different from those reported in another well studied non-climateric fruit, grape, suggesting that a single consistent pattern of hormone changes does not occur in this group of fruit during ripening.

Secular trends and distributional changes in health and fitness performance variables of 10-14-year-old children in New Zealand between 1991 and 2003.

BACKGROUND: New Zealand children's health and fitness performance is declining over time, but whether this change is because of deterioration in all children's health and fitness performance or can be attributed to just a certain portion of the population, is unknown. OBJECTIVES: In this study, secular trends and distributional changes in health-related and performance-related fitness components among New Zealand primary school children aged 10 to 14 years between 1991 and 2003 were tracked. METHODS: Health- and performance-related fitness parameters including height, weight, body mass index (BMI), flexibility, standing broad jump, 4 x 9-m agility run, abdominal curl-ups, and 550-m run were collected up to twice a year from 3306 children (10-14 years old) from a New Zealand school between 1991 and 2003. RESULTS: Over the 12-year period, the boys' weight increased by 4.5 kg (95% CL 2.7 to 6.2, or 0.8% per year) and girls' by 3.9 kg (95% CL 2.0 to 5.9, or 0.7% per year). Mean BMI increased by 0.12 kg m(-2) (0.6%) and 0.11 kg m(-2) (0.5%) per year for boys and girls, respectively. Children's 550-m run performance declined by 1.5% and 1.7% per year for boys and girls, respectively. Little difference existed between children located in the highest performing and leanest percentiles in 1991 and 2003, but for children in the poorest performing and fattest percentiles, their results were substantially worse in 2003. CONCLUSIONS: These results suggest that the deterioration in the health-related and performance-related fitness components of New Zealand 10-14-year-olds is not homogeneous but skewed towards those children who are the heaviest and perform worst in fitness tests. Previous research on health-related fitness parameters among children in New Zealand is limited but shows secular trends of increasing body mass1 2 in conjunction with deteriorating aerobic fitness performance, muscular endurance and explosive muscular power.3 Internationally, similar increases in body mass have been observed in children since the 1980s.1 4 5 Secular trends of deteriorating health-related fitness performance have also been reported among children around the world,1 5 6 with the most significant decreases observed in aerobic performance. However, trends in health-related variables reported as changes in mean body mass index (BMI) and mean aerobic fitness performance do not reveal possible changes in the distribution of BMI or aerobic performance within the population. Changes in such measures may come about because of a shift in the entire population under investigation or a change in a portion of the population. It is not clear whether New Zealand's entire childhood population is becoming heavier and less aerobically fit or whether only a portion of the children are becoming even heavier and more unfit, with the remaining children showing little secular change. The aim of this study was to track secular trends and distributional changes in body weight and physical fitness parameters among New Zealand primary school children aged 10 to 14 years.

Validation of the New Zealand Physical Activity Questionnaire (NZPAQ-LF) and the International Physical Activity Questionnaire (IPAQ-LF) with accelerometry.

BACKGROUND: Validation of instruments used to measure physical activity patterns is essential when attempting to assess the effectiveness of physical activity interventions. OBJECTIVES: To assess the validity of two self-report physical activity questionnaires on a representative sample of New Zealand adults. METHODS: 70 adults aged 18-65 years from around Christchurch, New Zealand were required to wear an ActiGraph GT1M accelerometer during all waking hours for 7 consecutive days. Immediately following the 7 day accelerometer period participants were required to complete the long forms of both the New Zealand Physical Activity Questionnaire (NZPAQ-LF) and the International Physical Activity Questionnaire (IPAQ-LF). RESULTS: Both the NZPAQ-LF and the IPAQ-LF questionnaires showed small to moderate correlations with ActiGraph data for time spent in moderate-intensity physical activity (r=0.19-0.30) and total physical activity (sum of moderate and vigorous-intensity physical activity, r=0.30-0.32). In comparison with the ActiGraph data, both self-report questionnaires tended to overestimate activity levels by approximately 165%. Total physical activity levels gathered from both questionnaires were strongly correlated with each other (r=0.79) and showed good levels of agreement in the Bland-Altman plots. CONCLUSIONS: The long forms of the NZPAQ and IPAQ were found to have acceptable validity when detecting participants' ability to meet activity guidelines based on exercise duration, but a significant amount of overestimation was evident. This presents a need for both instruments to be further developed and tested in order to increase validity.

Reducing catheter infections through use of the CD-1000: a retrospective review of a unique catheter specific composite dressing.

PURPOSE: Catheter-related blood stream infections pose a significant risk for patients living with vascular catheters. The cost to manage these infections is substantial. Although the etiology of these infections is multifactorial, tap water has been implicated as a significant causative factor. This retrospective review evaluates the effectiveness of a surgical dressing, the CD-1000, at protecting catheters and exit site wounds from fluid and debris when patients engage in high risk activities like showering. METHODS: All patients who received the CD-1000 from a single national medical supplier from September 2006 through to March 2007 were contacted to participate in this retrospective review; 209 patients, representing 34 states and 175 unique physicians, participated in this study. Effectiveness of the dressing along with prior and current history of catheter events was queried. RESULTS: The CD-1000 was 95% effective at keeping the catheter and exit site dry while patients engaged in high risk activities like showering. Prior to using the CD-1000, the 209 patients reported a historical catheter infection rate of 1.83 per 1000 catheter days. While using the CD-1000 the 209 patients reported a catheter infection rate of 0.47 per 1000 catheter days. CONCLUSION: The CD-1000 catheter specific composite dressing adequately protects vascular catheters and exit sites when patients engage in high risk activities like showering. In this geographically diverse retrospective review, use of the CD-1000 was associated with a 75% reduction in catheter associated infections.

Transthoracic two-dimensional high frequency (7.5 MHz) ultrasonic visualization of the distal left anterior descending coronary artery.

High frequency (7.5 MHz) two-dimensional ultrasound in combination with modified acoustic windows allowed visualization of the distal left anterior descending artery in 61 (85%) of 72 patients studied. Visualization was confirmed in one patient who underwent simultaneous high frequency ultrasound recording and selective dye injection into the left coronary artery. In addition, calcific coronary atherosclerosis was identified in one patient. The saphenous vein bypass graft along with its distal site of anastomosis was clearly seen in 3 patients and coronary artery flow was detected in 24 (33%).

Recognition and embolic potential of intraaortic atherosclerotic debris.

Atherosclerotic disease of the thoracic aorta is common in the elderly and patients with clinical coronary artery disease. Although embolization can occur from atherosclerotic debris within the thoracic aorta, it is not commonly considered in the differential diagnosis of the source of a systemic embolism. In the current study, the prevalence, clinical significance and embolic potential of intraaortic atherosclerotic debris as detected by transesophageal echocardiography was determined. Intraaortic atherosclerotic debris was identified in 38 (7%) of 556 patients undergoing transesophageal echocardiography. An embolic event occurred among 11 (31%) of the 36 study patients with intraaortic atherosclerotic debris. The incidence of an embolic event was higher when the debris was pedunculated and highly mobile (8 [73%] of 11 patients) than when it was layered and immobile (3 [12%] of 25 patients) (p less than 0.002). Among 15 patients undergoing an invasive procedure of the aorta, the incidence of embolism was 27%. In conclusion, in a patient with an embolic event, the thoracic aorta should be considered as a potential source. Transesophageal echocardiography can reliably detect intraaortic atherosclerotic debris, and when it is identified, an invasive aortic procedure should be avoided if possible.

Transthoracic high frequency (7.5 MHz) echocardiographic assessment of coronary vascular reserve and its relation to left ventricular mass.

Transthoracic high frequency (7.5 MHz) ultrasonography can visualize the distal left anterior descending coronary artery. Thirty-seven patients were studied before and after administration of 0.4 mg sublingual nitroglycerin to determine whether this technique could quantitatively record changes in coronary artery diameter after intervention. Left anterior descending coronary artery diameter increased from 2.2 to 2.8 mm (p less than 0.05). The vasodilator response of this artery was compared with left ventricular mass index in normal subjects, patients with congestive cardiomyopathy and those with end-stage renal disease and left ventricular hypertrophy. Left anterior descending artery diameter increased 55% in normal subjects, 27% in patients with dilated cardiomyopathy and 10% in those with end-stage renal disease with left ventricular hypertrophy. These results demonstrate that high frequency ultrasound can detect nitroglycerin-induced changes in left anterior descending artery diameter. The percent increase is related to the diameter before nitroglycerin administration, which is related to the underlying diagnosis and left ventricular mass index.

Distribution of Gibberellins in Lathyrus odoratus L. and Their Role in Leaf Growth.

In sweet pea (Lathyrus odoratus L.) the mutant allele l reduced the level of gibberellin A1 (GA1) in expanding leaflets and resulted in smaller, more oval leaflets compared with the wild type. The apical portions of 6-d-old wild-type (L) seedlings also contained less GA1 and produced smaller, more oval leaflets than did comparable 20-d-old L seedlings. Application of GA1 markedly altered leaflet shape and, at certain dosages, restored the wild-type shape and size to leaflets of the l (dwarf) mutant. Taken together, these observations indicate that GA1 performs a regulatory role in the control of leaf growth in this species. The levels of GA1 precursors in the wild type were also determined. Rapidly expanding internodes contained much more gibberellin A19 (GA19) than gibberellin A20 (GA20), whereas the opposite was true for expanding leaflets. Although in entire apical portions of established seedlings the level of GA20 exceeded that of GA19, apical portions of very young seedlings contained more GA19 than GA20. Basal stem tissue of established seedlings also contained substantially more GA19 than GA20 or GA1. Both stems and leaflets from the basal portion of the plant contained much less GA20 and GA1 than did the rapidly expanding apical tissue. The implications of these results for the regulation of GA1 biosynthesis are discussed.

Branching Mutant rms-2 in Pisum sativum (Grafting Studies and Endogenous Indole-3-Acetic Acid Levels).

Isogenic lines of pea (Pisum sativum L.) were used to determine the physiological site of action of the Rms-2 gene, which maintains apical dominance, and its effect on endogenous free indole-3-acetic acid (IAA) levels. In mutant rms-2 scions, which normally produce lateral branches below node 3 and above node 7, apical dominance was almost fully restored by grafting to Rms-2 (wild-type) stocks. In the reciprocal grafts, rms-2 stocks did not promote branching in wild-type shoots. Together, these results suggest that the Rms-2 gene inhibits branching in the shoot of pea by controlling the synthesis of a translocatable (hormone-like) substance that is produced in the roots and/or cotyledons and in the shoot. At all stages, including the stage at which aerial lateral buds commence outgrowth, the level of IAA in rms-2 shoots was elevated (up to 5-fold) in comparison with that in wild-type shoots. The internode length of rms-2 plants was 40% less than in wild-type plants, and the mutant plants allocated significantly more dry weight to the shoot than to the root in comparison with wild-type plants. Grafting to wild-type stocks did not normalize IAA levels or internode length in rms-2 scions, even though it inhibited branching, suggesting that the involvement of Rms-2 in the control of IAA level and internode length may be confined to processes in the shoot.

Branching in Pea (Action of Genes Rms3 and Rms4).

The nonallelic ramosus mutations rms3-2 and rms4 of pea (Pisum sativum L.) cause extensive release of vegetative axillary buds and lateral growth in comparison with wild-type (cv Torsdag) plants, in which axillary buds are not normally released under the conditions utilized. Grafting studies showed that the expression of the rms4 mutation in the shoot is independent of the genotype of the root-stock. In contrast, the length of the branches at certain nodes of rms3-2 plants was reduced by grafting to wild-type stocks, indicating that the wild-type Rms3 gene may control the level of a mobile substance produced in the root. This substance also appears to be produced in the shoot because Rms3 shoots did not branch when grafted to mutant rms3-2 rootstocks. However, the end product of the Rms3 gene appears to differ from that of the Rms2 gene (C.A. Beveridge, J.J. Ross, and I.C. Murfet [1994] Plant Physiol 104: 953-959) because reciprocal grafts between rms3-2 and rms2 seedlings produced mature shoots with apical dominance similar to that of rms3-2 and rms2 shoots grafted to wild-type stocks. Indole-3-acetic acid levels were not reduced in apical or nodal portions of rms4 plants and were actually elevated (up to 2-fold) in rms3-2 plants. It is suggested that further studies with these branching mutants may enable significant progress in understanding the normal control of apical dominance and the related communication between the root and shoot.

Decapitation Reduces the Metabolism of Gibberellin A20 to A1 in Pisum sativum L., Decreasing the Le/le Difference.

When the metabolism of [13C,3H]gibberellin (GA)20 in Pisum sativum L. was investigated using decapitated plants and stem sections, no evidence was obtained for the recently postulated inhibitor of GA20 3[beta]-hydroxylase (V.A. Smith [1992] Plant Physiol 99: 372-377). Instead, the results are consistent with the hypothesis that the mutation le reduces GA1 production by altering the structure or level of the 3[beta]-hydroxylase.

The Gibberellin Status of lip1, a Mutant of Pea That Exhibits Light-Independent Photomorphogenesis.

Dark-grown seedlings of the lip1 (light independent photomorphogenesis) mutant of Pisum sativum L. display many features of de-etiolated growth and are similar in many respects to wild-type (WT) seedlings grown in the light. The involvement of gibberellins (GAs) with the mutant phenotype was examined by applying GA1 and GA20 to the mutant and WT, and by quantifying endogenous GA1, GA8, GA19, GA20, and GA29 levels in the two genotypes. These experiments were conducted in both the light and the dark. In neither environment could GA application restore elongation in the mutant to that in GA-treated WT plants. Quantification of GAs provided further evidence that the mutant phenotype is not attributable to a deficiency in endogenous GA1. However, dark-grown lip1 seedlings contained lower levels of GA19 and higher levels of GA20 than dark-grown WT plants, whereas in the light, the effect of the mutation on the ratio of GA19 to GA20 was reversed. Thus, there appears to be a complex interaction between the lip1 mutation, the light regime, and the step GA19 to GA20.

Control of Internode Length in Pisum sativum (Further Evidence for the Involvement of Indole-3-Acetic Acid).

The effects of altered endogenous indole-3-acetic (IAA) levels on elongation in garden pea (Pisum sativum L.) plants were investigated. The auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and 9-hydroxyfluorene-9-carboxylic acid (HFCA) were applied to elongating internodes of wild-type and mutant lkb plants. The lkb mutant was included because elongating lkb internodes contained 2- to 3-fold less free IAA than those of the wild type. In the wild type, TIBA reduced both the IAA level and internode elongation below the site of application. Both TIBA and HFCA strongly promoted the elongation of lkb internodes and also raised IAA levels above the application site. The synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) also markedly increased internode elongation in lkb plants and virtually restored petioles and tendrils to their wild-type length. In contrast, treatment of wild-type plants with TIBA, HFCA, or 2,4-D caused little or no increase in elongation above the application site. The ethylene synthesis inhibitor aminoethoxyvinylglycine also increased stem elongation in lkb plants, and combined application of HFCA and aminoethoxy-vinylglycine restored lkb internodes to the wild-type length. It is concluded that the level of IAA in wild-type internodes is necessary for normal elongation, and that the reduced stature of lkb plants is at least partially attributable to a reduction in free IAA level in this mutant.

ECM gene expression correlates with in vitro tissue growth and development in fibrin gel remodeled by neonatal smooth muscle cells.

A tissue growth and development process occurred in neonatal SMC-fibrin gel constructs when cultured in DMEM supplemented with TGF-beta1 and insulin over a 5 week period. These constructs may thus serve as the basis for cardiovascular tissue replacements and future models of cardiovascular tissue growth, repair and regeneration. Following fibrin gel contraction during week 1, peak rates of SMC proliferation, collagen production and tropoelastin production occurred between weeks 1-4. Organized, cross-linked collagen and elastic fibers replaced the degrading fibrin over weeks 3-5 and were manifested as increased mechanical strength. The peak rate of SMC proliferation (weeks 1-2) preceded that for maximum collagen production (weeks 2-4), which was consistent with the 3 week time point of maximum expression of collagen type I and III from qRT-PCR. Insoluble elastin quantification revealed that the majority of elastic fibers were produced by week 4, which was also consistent with the qRT-PCR data showing a dramatic down-regulation of tropoelastin expression by week 4, indicating elastogenesis occurred during the early stages of tissue growth and development. There was a strong up-regulation of lysyl oxidase expression during weeks 1-3 with a peak in expression at week 3, correlating with the phases of collagen and tropoelastin production. An increase in MMP-2 expression over weeks 1-5 suggested an increase in ECM remodeling as the tissue developed. Mechanical strength doubled over weeks 4-5 when production of collagen and elastic fibers and expression of lysyl oxidase were subsiding. This may have been due in part to the more organized collagen fibrils evident from the histological sections in weeks 3-5.

Single-plane transesophageal echocardiography for assessing function of mechanical or bioprosthetic valves in the aortic valve position.

To assess the value and limitations of single-plane transesophageal echocardiography in the evaluation of prosthetic aortic valve function, 89 patients (69 mechanical and 20 bioprosthetic aortic valves) were studied by combined transthoracic and transesophageal 2-dimensional and color flow Doppler echocardiography. In the assessment of aortic regurgitation, the transthoracic and transesophageal echocardiographic findings were concordant in 71 of 89 patients (80%). In 8 patients, the degree of aortic regurgitation was underestimated by the transthoracic approach; in each case the quality of the transthoracic echocardiogram was poor. In 10 patients, transesophageal echocardiography failed to detect trivial aortic regurgitation due to acoustic shadowing of the left ventricular outflow tract from a mechanical valve in the mitral valve position. Transesophageal echocardiography was superior to transthoracic echocardiography in diagnosing perivalvular abscess, subaortic perforation, valvular dehiscence, torn or thickened bioprosthetic aortic valve cusps, and in clearly distinguishing perivalvular from valvular aortic regurgitation. Transesophageal echocardiography correctly diagnosed bioprosthetic valve obstruction in 1 patient, but failed to diagnose mechanical valve obstruction in another. In conclusion, transesophageal echocardiography offers no advantage over the transthoracic approach in the detection and quantification of prosthetic aortic regurgitation unless the transthoracic image quality is poor. Transesophageal echocardiography is limited in detecting mechanical valve obstruction and in detecting aortic regurgitation in the presence of a mechanical prosthesis in the mitral valve position. However, it is superior to transthoracic echocardiography in identifying perivalvular pathology, differentiating perivalvular from valvular regurgitation and in defining the anatomic abnormality responsible for the prosthetic valve dysfunction. Combined transthoracic and transesophageal examination provides complete anatomic and hemodynamic assessment of prosthetic aortic valve function.

Transesophageal echocardiographic diagnosis of pulmonary arteriovenous malformation. Role of contrast and pulsed Doppler echocardiography.

Contrast echocardiography produced by peripheral injection of agitated saline solution is widely used for detecting intracardiac and intrathoracic extracardiac shunts, like pulmonary arteriovenous malformation (PAVM). Currently, localization of PAVM requires pulmonary angiography even after detection by computed tomography of the chest. Pulsed Doppler along with contrast echocardiography of the pulmonary veins performed during transesophageal echocardiography may aid in the localization of PAVM and in its diagnosis.

Diagnosis of superior vena caval obstruction by transesophageal echocardiography.

Superior vena caval (SVC) syndrome may be caused by extravascular compression or intravascular obstruction. Knowing the mechanism of SVC syndrome enables the physician to choose appropriate treatment. Transesophageal echocardiography (TEE) is a safe bedside procedure that is excellent for evaluating the SVC and its surrounding structures. We report the valuable role of TEE in demonstrating the mechanism of SVC syndrome.

Impact of the incidental diagnosis of clinically unsuspected central pulmonary artery thromboembolism in treatment of critically ill patients.

Mortality is high in unrecognized pulmonary embolism (PE), but the diagnosis is difficult to establish, especially in patients with coexisting cardiopulmonary disorders. We describe a group of 14 patients with pulmonary thromboemboli in whom transesophageal echocardiography (TEE) performed for coexisting cardiopulmonary conditions established the clinical diagnosis of PE not suspected prior to TEE. The patients had initial clinical diagnoses of heart failure (eight patients), cardiogenic shock (two patients), atrial septal defect (two patients), aortic dissection (one patient), and pneumonia (one patient). Thirteen patients had risk factors for PE. Transthoracic echocardiography (TTE) demonstrated right heart strain in eight patients but did not visualize PE in any of the patients. The TEE diagnosis of occult central pulmonary artery thromboembolism changed treatment in all 14 patients. Ten of the 14 patients were successfully discharged from the hospital. We conclude that occult central pulmonary artery thromboemboli are not uncommon in patients presenting with acute cardiopulmonary disorders and the presence of risk factors for PE and right heart strain on TTE should alert the physician to suspect PE. If and when TEE is performed in patients with acute cardiopulmonary disorders with risk factors for PE and right heart strain, the physician should evaluate the main pulmonary artery and its branches for central pulmonary artery thromboemboli.

Transfer of differentiated synaptic terminals from primary myotubes to new-formed muscle cells during embryonic development in the rat.

Most fibres in adult muscles are derived from secondary myotubes which form around an earlier developing population of primary myotubes. We examined embryonic rat IVth lumbrical muscles at a stage when most secondary myotubes were less than 24 h old, in order to study their acquisition of synaptic terminals. Single nerve terminals were frequently seen to synapse simultaneously with a well-developed primary myotube and a new-formed secondary myotube. Reconstructions of serial section electron micrographs revealed that most of these shared terminals had synaptic specializations opposed to the primary myotube, but others appeared to transmit mainly to the secondary myotube. Primary myotubes are contacted by multiple nerve terminals before secondary myotube formation has begun, and we suggest that synaptic terminals are progressively transferred from primaries to secondaries, the observed shared terminals representing intermediate stages in this transfer.