A randomized clinical trial of an eHealth intervention on anxiety in patients undergoing abdominal aortic aneurysm surgery.

BACKGROUND: The potential benefit of eHealth interventions in patients with abdominal aortic aneurysm (AAA) is uncertain. The primary aim of this study was to investigate the effect of an eHealth intervention on anxiety in patients with AAA undergoing surgery. METHODS: A single-centre randomized clinical trial of patients with AAA scheduled for surgical repair was undertaken. The intervention group received an eHealth tool and psychosocial support besides standard care. The control group received standard care. The analysis of treatment effects was performed as intention-to-treat and per protocol analysis. The primary outcome measure was anxiety mean score (Hospital Anxiety and Depression Scale Anxiety (HADS)-A). Secondary outcomes measures were HADS Depression and short-form 12-item health survey mean scores. RESULTS: Some 120 participants were randomized. No effect on anxiety mean scores was found in the intention-to-treat analysis (-1.21 versus -0.54, P = 0.330). Among those randomized to the intervention, only 30 of 60 participants used the eHealth tool (application (app) users). The app users were younger and had a higher educational level. A decrease in anxiety mean scores was noted in those who used the app in the per protocol analysis (-2.00 versus -0.54, P = 0.028). The intervention group stated a lower physical-component health-related quality of life (HRQoL) (-4.32 versus -1.16, P = 0.042) but mental-component HRQoL and depressive symptoms were unchanged. CONCLUSIONS: Delivery of an eHealth intervention in this RCT did not result in an improvement in anxiety scores in patients awaiting AAA surgery. Uptake of the eHealth tool was low, although it resulted in lower anxiety scores in those participants who actually used it. CLINICAL TRIAL REGISTRATION NUMBER: NCT03157973 (http://www.clinicaltrials.gov).

The use of digital health technology to deliver information and provide psychosocial support has shown promising results but has been largely unexplored in people undergoing major blood vessel (vascular) surgery. This study reports the results of a randomized, controlled trial to examine the effects of an eHealth intervention on anxiety symptoms in patients undergoing surgical treatment of abdominal aortic aneurysm (a major swelling of the main blood vessel in the tummy). The findings show that an eHealth tool paired with psychosocial support did not reduce anxiety symptoms, measured by Hospital Anxiety and Depression Scale-A. Unfortunately, a large proportion of the participants declined to use the eHealth tool. However, those who used the eHealth tool appeared to benefit from reduced anxiety levels. The findings of the study support further research to understand how to improve engagement of patients with eHealth interventions in surgery. Special attention should be given to improve engagement in people who are elderly and those with lower educational attainment.

Monitoring of Human Uterus Transplantation With Cervical Biopsies: A Provisional Scoring System for Rejection.

Until now, absolute uterine factor infertility has been the major untreatable form of female infertility. Uterus transplantation has recently proven to be the first successful treatment for absolute uterine factor infertility, with demonstration of live births. In this study, live donation uterus transplantation was performed in nine women. In total, 163 cervical biopsies (149 protocol, 14 follow-up) were taken to detect histopathological signs of rejection. Based on experience from animal experiments, we used a three-grade scoring system to evaluate biopsies systematically. Nine episodes of rejection were diagnosed in five patients: grade 1 in six episodes, grade 2 in two episodes, and grade 3 in one episode. Treatment decisions were based on histopathology, and all rejection episodes were reversed after treatment. The biopsies were reviewed retrospectively, and immunohistochemistry was performed to characterize the inflammatory infiltrates. A borderline category was introduced to avoid overtreatment of patients. Based on our review of all biopsies, we put forward a simple grading system for monitoring of rejection and to guide immunosuppressive treatment in uterus transplantation.

Accelerated Skeletal Maturation in Disorders of Retinoic Acid Metabolism: A Case Report and Focused Review of the Literature.

Nutritional excess of vitamin A, a precursor for retinoic acid (RA), causes premature epiphyseal fusion, craniosynostosis, and light-dependent retinopathy. Similarly, homozygous loss-of-function mutations in CYP26B1, one of the major RA-metabolizing enzymes, cause advanced bone age, premature epiphyseal fusion, and craniosynostosis. In this paper, a patient with markedly accelerated skeletal and dental development, retinal scarring, and autism-spectrum disease is presented and the role of retinoic acid in longitudinal bone growth and skeletal maturation is reviewed. Genetic studies were carried out using SNP array and exome sequencing. RA isomers were measured in the patient, family members, and in 18 age-matched healthy children using high-performance liquid chromatography coupled to tandem mass spectrometry. A genomic SNP array identified a novel 8.3 megabase microdeletion on chromosome 10q23.2-23.33. The 79 deleted genes included CYP26A1 and C1, both major RA-metabolizing enzymes. Exome sequencing did not detect any variants that were predicted to be deleterious in the remaining alleles of these genes or other known retinoic acid-metabolizing enzymes. The patient exhibited elevated plasma total RA (16.5 vs. 12.6±1.5 nM, mean±SD, subject vs. controls) and 13-cisRA (10.7 nM vs. 6.1±1.1). The findings support the hypothesis that elevated RA concentrations accelerate bone and dental maturation in humans. CYP26A1 and C1 haploinsufficiency may contribute to the elevated retinoic acid concentrations and clinical findings of the patient, although this phenotype has not been reported in other patients with similar deletions, suggesting that other unknown genetic or environmental factors may also contribute.

Factor H binds to the hypervariable region of many Streptococcus pyogenes M proteins but does not promote phagocytosis resistance or acute virulence.

Many pathogens express a surface protein that binds the human complement regulator factor H (FH), as first described for Streptococcus pyogenes and the antiphagocytic M6 protein. It is commonly assumed that FH recruited to an M protein enhances virulence by protecting the bacteria against complement deposition and phagocytosis, but the role of FH-binding in S. pyogenes pathogenesis has remained unclear and controversial. Here, we studied seven purified M proteins for ability to bind FH and found that FH binds to the M5, M6 and M18 proteins but not the M1, M3, M4 and M22 proteins. Extensive immunochemical analysis indicated that FH binds solely to the hypervariable region (HVR) of an M protein, suggesting that selection has favored the ability of certain HVRs to bind FH. These FH-binding HVRs could be studied as isolated polypeptides that retain ability to bind FH, implying that an FH-binding HVR represents a distinct ligand-binding domain. The isolated HVRs specifically interacted with FH among all human serum proteins, interacted with the same region in FH and showed species specificity, but exhibited little or no antigenic cross-reactivity. Although these findings suggested that FH recruited to an M protein promotes virulence, studies in transgenic mice did not demonstrate a role for bound FH during acute infection. Moreover, phagocytosis tests indicated that ability to bind FH is neither sufficient nor necessary for S. pyogenes to resist killing in whole human blood. While these data shed new light on the HVR of M proteins, they suggest that FH-binding may affect S. pyogenes virulence by mechanisms not assessed in currently used model systems.

Bedside diagnosis of mitochondrial dysfunction in aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Aneurysmal subarachnoid hemorrhage (SAH) is frequently associated with delayed neurological deterioration (DND). Several studies have shown that DND is not always related to vasospasm and ischemia. Experimental and clinical studies have recently documented that it is possible to diagnose and separate cerebral ischemia and mitochondrial dysfunction bedside. The study explores whether cerebral biochemical variables in SAH patients most frequently exhibit a pattern indicating ischemia or mitochondrial dysfunction. METHODS: In 55 patients with severe SAH, intracerebral microdialysis was performed during neurocritical care with bedside analysis and display of glucose, pyruvate, lactate, glutamate, and glycerol. The biochemical patterns observed were compared to those previously described in animal studies of induced mitochondrial dysfunction as well as the pattern obtained in patients with recirculated cerebral infarcts. RESULTS: In 29 patients, the biochemical pattern indicated mitochondrial dysfunction while 10 patients showed a pattern of cerebral ischemia, six of which also exhibited periods of mitochondrial dysfunction. Mitochondrial dysfunction was observed during 5162 h. An ischemic pattern was obtained during 688 h. Four of the patients (40%) with biochemical signs of ischemia died at the neurosurgical department as compared with three patients (10%) in the group of mitochondrial dysfunction. CONCLUSIONS: The study documents that mitochondrial dysfunction is a common cause of disturbed cerebral energy metabolism in patients with SAH. Mitochondrial dysfunction may increase tissue sensitivity to secondary adverse events such as vasospasm and decreased cerebral blood flow. The separation of ischemia and mitochondrial dysfunction bedside by utilizing microdialysis offers a possibility to evaluate new therapies.

Effect of competitive exclusion in reducing the occurrence of Escherichia coli producing extended-spectrum ß-lactamases in the ceca of broiler chicks.

Extended-spectrum ß-lactamases (ESBL) and class C serine ß-lactamases (pAmpC) able to hydrolyze third-generation cephalosporins are a recognized threat to the efficacy of these drugs in treating serious infections. Broiler chicks are a known source of Escherichia coli harboring genes for these enzymes. Competitive exclusion (CE) has been used for decades in Finland to prevent the colonization of broiler ceca by Salmonella, but has not been widely used in Sweden. The markedly different prevalences of ESBL- or pAmpC-producing E. coli at slaughter in broilers produced in the 2 countries suggest a potential role for CE. The present study was undertaken to determine the efficacy of a commercial CE product in reducing the colonization of broiler ceca by ESBL- or pAmpC-producing E. coli. The challenge organisms were isolated from healthy broilers in Sweden. Each E. coli strain (1 ESBL and 2 pAmpC types) was subjected to 4 replicate trials. In each trial, a group of 20 newly hatched Ross breed chicks were treated by gavage with the CE product, whereas another group of 20 was left untreated. The next day, all 40 chicks were inoculated by gavage with the E. coli strain. The chicks were reared in cardboard boxes and received feed and water ad libitum. After a week the chicks were asphyxiated with CO(2), and their ceca removed and examined for the presence of the E. coli strains. The median and quartiles of the challenge E. coli estimates in the groups were determined, and the treated and control groups were compared with the Wilcoxon 2-sample test. In each trial, a substantial and statistically significant or highly significant reduction was observed in the colonization of the ceca of CE-treated chicks by E. coli strains, compared with that of untreated control. Referring to an arbitrary criterion for high shedders presented in the literature, it was concluded that at least for the ESBL E. coli, the results were also of epidemiological relevance.

The multifaceted roles of FLOWERING LOCUS T in plant development.

One of the key developmental processes in flowering plants is the differentiation of the shoot apical meristem into a floral meristem. This transition is regulated through the integration of environmental and endogenous stimuli, involving a complex, hierarchical signalling network. In arabidopsis, the FLOWERING LOCUS T (FT) protein, a mobile signal recognized as a major component of florigen, has a central position in mediating the onset of flowering. FT-like genes seem to be involved in regulating the floral transition in all angiosperms examined to date. Evidence from molecular evolution studies suggests that the emergence of FT-like genes coincided with the evolution of the flowering plants. Hence, the role of FT in floral promotion is conserved, but appears to be restricted to the angiosperms. Besides flowering, FT-like proteins have also been identified as major regulatory factors in a wide range of developmental processes including fruit set, vegetative growth, stomatal control and tuberization. These multifaceted roles of FT-like proteins have resulted from extensive gene duplication events, which occurred independently in nearly all modern angiosperm lineages, followed by sub- or neo-functionalization. This review assesses the plethora of roles that FT-like genes have acquired during evolution and their implications in plant diversity, adaptation and domestication.

Characterization of the dog lipocalin allergen Can f 6: the role in cross-reactivity with cat and horse.

BACKGROUND: Allergy to the domestic dog (Canis familiaris) affects 5-10% of the population in affluent countries. Three of four patients are allergic to more than one pet, which can only partially be explained by cross-reactivity between serum albumins. The lipocalin protein family harbours allergens in mammalian species. METHODS: We set out to clone and characterize a novel dog allergen, and investigate its potential role in cross-sensitization between dog, cat and horse. The gene encoding Can f 6 was amplified from dog skin and bladder cDNA libraries. The corresponding allergen was produced and purified by recombinant techniques and evaluated by SDS-PAGE, size exclusion chromatography, circular dichroism spectra, ELISA and basophil activation test. RESULTS: IgE antibodies to Can f 6 were found in serum from 38% of dog-sensitized subjects. Sequence similarities between the lipocalin allergens Can f 6, Fel d 4 (cat) and Equ c 1 (horse) suggested a probability for cross-reactivity, which was demonstrated by competitive ELISA. The biological relevance of Can f 6 was confirmed by basophil activation test in dog-allergic patients. CONCLUSION: Can f 6 is a new lipocalin dog allergen that cross-reacts with lipocalins from horse and cat. Can f 6 and homologous allergens may contribute to multisensitization and symptoms in individuals allergic to mammals.

Specific binding and uptake of 131I-MIBG and 111In-octreotide in metastatic paraganglioma--tools for choice of radionuclide therapy.

Tumor-specific uptake of the radiolabeled nor-epinephrine analogue meta-iodobenzylguanidine via norepinephrine transporter or radiolabeled somatostatin analogues octreotide/octreotate via somatostatin receptors offers possibilities to diagnose and treat metastatic pheochromocytoma/paraganglioma. High uptake of 123I-meta-iodobenzylguanidine is dependent on high expression of vesicular monoamine transporters responsible for mediating uptake of biogenic amines into dense core granules. A patient with metastatic paraganglioma (liver and bone metastases) underwent surgical removal of the primary after injection of 131I-meta-iodobenzylguanidine and 111In-octreotide. Radioactivity was determined in biopsies from tumor and normal tissue biopsies. The tumor/blood concentration value was high: 180 for 131I-meta-iodobenzylguanidine 3 h after injection and 590 for 111In-octreotide 27 h after injection. Studies of primary tumor cell cultures demonstrated increased cell membrane binding and internalization over time for 131I-meta-iodobenzylguanidine. The vesicular monoamine transporter antagonist reserpine and the norepinephrine transporter inhibitor clomipramine reduced internalization by 90% and 70%, respectively, after 46 h of incubation. The results demonstrated increased cell membrane binding and internalization over time also for 111In-octreotide. Internalization was highest for a low concentration of 111In-octreotide. Excess of octreotide reduced internalization of 111In-octreotide with 75% after 46 h of incubation. In conclusion, uptake and tumor/blood concentration values of radiolabeled meta-iodobenzylguanidine and somatostatin analogues can be determined for metastatic pheochromocytoma/paraganglioma to evaluate the possibility to use one or both agents for therapy. For this patient, the high tumor/blood values clearly demonstrated that therapy using both radiopharmaceuticals would be most beneficial. In vitro studies verified specific cell-membrane binding and internalization in tumor cells of both radiopharmaceuticals.

Genetic diversity among VRE isolates from Swedish broilers with the coincidental finding of transferrable decreased susceptibility to narasin.

AIMS: In this study, the molecular diversity among clones of vancomycin resistant Enterococcus faecium with vanA gene (VRE) is investigated. The aims were to better understand why one clone is predominant in Swedish broiler production and to better assess the potential for zoonotic gene transfer from the different clones. METHODS AND RESULTS: Twenty-six isolates were separated into 11 clones. Vancomycin resistance was transferrable from the predominant and five minority clones. Decreased susceptibility to narasin was co-transferred with vancomycin resistance in four clones, including the predominant. The plasmid addiction system axe-txe was not detected, and the ω-ε-ζ system was detected in one of the minority clones but was not co-transferred with vancomycin resistance. CONCLUSIONS: The results do not explain why one clone is predominant among VRE in Swedish broiler production but confirms the potential for zoonotic spread of vancomycin resistance genes. The near absence of investigated plasmid addiction systems indicates that they do not play an important role in the epidemiology of VRE in Swedish broiler production. The finding that decreased susceptibility to narasin can be co-transferred with the vanA gene indicates that the use of narasin might play a role in the persistence of vancomycin resistance in enterococci colonizing Swedish broilers. SIGNIFICANCE AND IMPACT OF THE STUDY: This is, to our knowledge, the first report of transferrable decreased susceptibility to narasin.

Inter-batch contamination and potential sources of vancomycin-resistant Enterococcus faecium on broiler farms.

1. Vancomycin-resistant Enterococcus faecium (VRE(fm)) has recently spread among Swedish broiler farms. The objectives were to investigate VRE(fm) persistence within barns between flocks, and to determine whether day-old chicks, feed or forklift trucks used for loading crates could be identified as a means of transmission. 2. Faeces were collected for selective culture from 12 farms (9 culture-positive, 3 culture-negative as determined by prior monitoring), and samples were collected from the barn environment before and after cleaning and disinfection, from forklift tyres, hatcheries and feed. 3. VRE(fm) was isolated only from previously known VRE(fm)-positive farms. The proportions of culture-positive environmental samples were 75% (9 out of 9 farms) prior to and 31% (7 out of 9 farms) after cleaning/disinfection. Five out of 6 samples from forklift tyres were culture-positive. No VRE(fm) were isolated from feed or hatcheries. The majority of 27 vanA gene positive isolates showed similar banding patterns by SmaI restriction digestion and pulse-field gel electrophoresis. No consistent differences were observed regarding management between VRE(fm)-positive and negative farms. 4. We conclude that VRE(fm) contaminates barns and remains present between flocks. Forklift trucks are one possible means of transmission between farms.

Spread without known selective pressure of a vancomycin-resistant clone of Enterococcus faecium among broilers.

OBJECTIVES: The aim of this paper was to describe an increased occurrence of vancomycin-resistant enterococci (VRE) in Swedish broilers since 2000 and to investigate the genetic relatedness of isolates. METHODS: Caecal content from slaughtered broilers was cultured for VRE on medium supplemented with vancomycin (16 mg/L). Species identification, antibiotic susceptibility determination, vancomycin resistance genotyping, multilocus sequence typing (MLST) and characterization of Tn1546 were performed. RESULTS: The proportion of VRE-positive samples increased gradually from <1% in 2000 to slightly over 40% in 2005. Between 2005 and 2006, the proportion of VRE-positive samples decreased and between 2006 and 2007, it was stable at just below 30%. All isolates tested were Enterococcus faecium and carried the vanA gene. A majority of the isolates had similar antibiograms, the same MLST sequence type and Tn1546 transposon. CONCLUSIONS: The proportion of VRE-positive samples from broilers has increased since 2000, and this is due to the spread of one major clone. Moreover, this has taken place in an environment without any obvious selective pressure.

Prolonged survival after hepatic artery embolization in patients with midgut carcinoid syndrome.

BACKGROUND: Hepatic artery embolization (HAE) is a palliative treatment for patients with liver metastases from neuroendocrine tumours. HAE reduces hormonal symptoms, but its impact on survival has been questioned. METHODS: Biochemical responses and survival in consecutive patients with disseminated liver metastases from midgut carcinoid tumours were studied after HAE. Repeat HAE was performed in selected patients with radiological and biochemical signs of progression. RESULTS: Of 107 patients who had HAE, the median survival from the first procedure was 56 (range 1-204) months. Prolonged survival showed a strong correlation with reduction of urinary 5-hydroxyindoleacetic acid (P = 0.003) and plasma chromogranin A (P = 0.001) levels. The biochemical response to repeat HAE was similar to that for the first procedure (P = 0.002). The complication rate was low (7.5 per cent), as was the mortality rate (1.9 per cent) within 1 month of HAE. CONCLUSION: HAE is safe, provides good control of hormonal symptoms, and prolongs survival in biochemically responsive patients. It is a valuable palliative option for patients with midgut carcinoid syndrome due to liver metastases and can be repeated in patients with a favourable response to the first procedure.

Characterization of monoclonal antibodies directed against squamous cell carcinoma antigens: report of the second TD-10 workshop.

Eight monoclonal antibodies directed against Squamous Cell Carcinoma Antigens (A1 and A2) were collected and evaluated by three working groups. Recombinant antigens, fusion proteins and native antigens from normal tissue were used to evaluate antibody specificity. Five antibodies reacted with both A1 and A2. Two of these antibodies (K123 and K131) showed related binding characteristics, whereas SCC140, K182 and SCC111 demonstrated unique epitope specificity and were not related to the reference antibodies included (F1H3, F2H7 and SCC107). SCC111 reacted particularly well with antigen on Western blot, indicating that the epitope was partly hidden when the antigen was in solution. Two antibodies (SCC103 and SCC109) reacted only with A2 and the fusion protein A1/A2, indicating that they recognized an A2 epitope in exon 8. The A2-specific antibodies are unique in their binding to A2 and are different from the reference antibodies included (SCC104 and K122). SCC103 is probably the best A2-specific antibody available. One antibody, K136, was A1-specific and is related to reference antibody K135. The new antibodies can be used to establish immunometric assays for specific measurement of A1, A2 or both A1 and A2 together.

Enzyme and phospholipid asymmetry in liver microsomal membranes.

The transverse distribution of enzyme proteins and phospholipids within microsomal membranes was studied by analyzing membrane composition after treatment with proteases and phospholipases. Upon trypsin treatment of closed microsomal vesicles, NADH- and NADPH-cytochrome c reductases as well as cytochrome b5 were solubilized or inactivated, while cytochrome P-450 was partially inactivated. When microsomes were exposed to a concentration of deoxycholate which makes them permeable to macromolecules but does not disrupt the membrane, the detergent alone was sufficient to release four enzymes: nucleoside diphosphatase, esterase, beta-glucuronidase, and a portion of the DT-diaphorase. Introduction of trypsin into the vesicle lumen inactivated glucose-6-phosphatase completely and cytochrome P-450 partially. The rest of this cytochrome, ATPase, AMPase, UDP-glucuronyltransferase, and the remaining 50% of DT-diaphorase activity were not affected by proteolysis from either side of the membrane. Phospholipase A treatment of intact microsomes in the presence of albumin hydrolyzed all of the phosphatidylethanolamine, phosphatidylserine, and 55% of the phosphatidylcholine. From this observation, it was concluded that these lipids are localized in the outer half of the bilayer of the microsomal membrane; Phosphatidylinositol, 45% of the phosphatidylcholine, and sphingomyelin are tentatively assigned to the inner half of this bilayer. It appears that the various enzyme proteins and phospholipids of the microsomal membrane display an asymmetric distribution in the transverse plane.

Thermal conductivity of monolithic organic aerogels.

The total thermal conductivity lambda of resorcinol-formaldehyde aerogel monoliths has been measured as a function of density rho in the range from rho = 80 to 300 kilograms per cubic meter. A record-low conductivity value in air at 300 K of lambda approximately 0.012 watt per meter per kelvin was found for rho approximately 157 kilograms per cubic meter. Caloric measurements under variation of gas pressure as well as spectral infrared transmission measurements allowed the determination of solid conductivity, gaseous conductivity, and radiative conductivity as a function of density. The development of such low conductivity materials is of great interest with respect to the substitution of environmentally harmful insulating foams made from chlorofluorocarbons.

Parascaris equorum in foals and in their environment on a Swedish stud farm, with notes on treatment failure of ivermectin.

Environmental contamination and the egg excretion pattern of the ascarid Parascaris equorum (Nematoda) was investigated in relation to anthelmintic treatment on a Swedish stud farm. Faecal samples from 15 foals, dewormed every 8th-week with a paste formulation of ivermectin at the standard dose rate of 0.2 mg/kg bodyweight, were collected at five sampling occasions between August and November 2006. In addition, soil samples were obtained from four paddocks used by these foals in November 2006. The number of eggs per gram (epg) was counted in both faeces and soil. Egg excretion started when the foals were 3-4 months, and reached the highest levels when they were approximately 5-month-old, and was then followed by a decline. Egg excretion seemed to be unaffected by ivermectin despite these foals were dewormed at regular intervals. In four out of five foals examined 10 days after treatment, epg actually increased. In contrast, when either fenbendazol or pyrantel embonate were used instead of ivermectin, treatments were effective. The number of eggs in soil was significantly higher in the permanent paddock compared to in the temporarily used soil paddock and in the summer paddocks.

A LEAFY co-regulator encoded by UNUSUAL FLORAL ORGANS.

BACKGROUND: . Development of petals and stamens in Arabidopsis flowers requires the function of the organ-identity gene APETALA3 (AP3), whose RNA is expressed specifically in petal and stamen primordia. AP3 expression is positively regulated by the meristem-identity gene LEAFY (LFY), which is expressed ubiquitously in young flowers. It is unknown how the transition from ubiquitous expression of LFY to region-specific expression of AP3 is made. It has previously been proposed for Antirrhinum that another gene, FIMBRIATA (FIM), mediates between the LFY and AP3 orthologs, with the three genes acting in a simple regulatory hierarchy. FIM is activated later than the LFY ortholog, and its expression is more restricted than that of the LFY ortholog. RESULTS: . We have tested whether the model proposed for Antirrhinum applies to Arabidopsis, by creating transgenic plants in which the FIM ortholog UNUSUAL FLORAL ORGANS (UFO) was expressed constitutively from the promoter of the cauliflower mosaic virus 35S gene. In 35S::UFO flowers, AP3 was expressed precociously and ectopically, confirming that UFO is an upstream regulator of AP3. However, 35S::UFO could not restore petal and stamen development in lfy mutants, indicating that UFO can only function in the presence of LFY activity. The failure of 35S::UFO to rescue lfy mutants is consistent with our observation that UFO expression levels are not markedly changed in lfy mutants. CONCLUSIONS: . We conclude that UFO is not a simple mediator between meristem- and organ-identity genes, but is likely to be a partially dispensable co-regulator that acts together with LFY. The interplay between LFY and UFO provides a paradigm for how a global regulator such as LFY activates selected target genes only in restricted regions within its expression domain.

Spatial and temporal regulation of GH-IGF-related gene expression in growth plate cartilage.

Previous studies of the GH-IGF system gene expression in growth plate using immunohistochemistry and in situ hybridization have yielded conflicting results. We therefore studied the spatial and temporal patterns of mRNA expression of the GH-IGF system in the rat proximal tibial growth plate quantitatively. Growth plates were microdissected into individual zones. RNA was extracted, reverse transcribed and analyzed by real-time PCR. In 1-week-old animals, IGF-I mRNA expression was minimal in growth plate compared with perichondrium, metaphyseal bone, muscle, and liver (70-, 130-, 215-, and 400-fold less). In contrast, IGF-II mRNA was expressed at higher levels than in bone and liver (65- and 2-fold). IGF-II expression was higher in the proliferative and resting zones compared with the hypertrophic zone (P < 0.001). GH receptor and type 1 and 2 IGF receptors were expressed throughout the growth plate. Expression of IGF-binding proteins (IGFBPs)-1 through -6 mRNA was low throughout the growth plate compared with perichondrium and bone. With increasing age (3-, 6-, 9-, and 12-week castrated rats), IGF-I mRNA levels increased in the proliferative zone (PZ) but remained at least tenfold lower than levels in perichondrium and bone. IGF-II mRNA decreased dramatically in PZ (780-fold; P < 0.001) whereas, type 2 IGF receptor and IGFBP-1, IGFBP-2, IGFBP-3, and IGFBP-4 increased significantly with age in growth plate and/or surrounding perichondrium and bone. These data suggest that IGF-I protein in the growth plate is not produced primarily by the chondrocytes themselves. Instead, it derives from surrounding perichondrium and bone. In addition, the decrease in growth velocity that occurs with age may be caused, in part, by decreasing expression of IGF-II and increasing expression of type 2 IGF receptor and multiple IGFBPs.

Gibberellins promote flowering of arabidopsis by activating the LEAFY promoter

The gibberellin class of plant hormones has been implicated in the control of flowering in several species. In Arabidopsis, severe reduction of endogenous gibberellins delays flowering in long days and prevents flowering in short days. We have investigated how the differential effects of gibberellins on flowering correlate with expression of LEAFY, a floral meristem identity gene. We have found that the failure of gibberellin-deficient ga1-3 mutants to flower in short days was paralleled by the absence of LEAFY promoter induction. A causal connection between these two events was confirmed by the ability of a constitutively expressed LEAFY transgene to restore flowering to ga1-3 mutants in short days. In contrast to short days, impairment of gibberellin biosynthesis caused merely a reduction of LEAFY expression when plants were grown in long days or with sucrose in the dark. As a first step toward identifying other small molecules that might regulate flowering, we have developed a rapid in vitro assay for LEAFY promoter activity.