The developmental expression of the maize regulatory gene Hopi determines germination-dependent anthocyanin accumulation.

The Hopi gene is a member of the maize r1 gene family. By genetic and molecular analyses we report that Hopi consists of a single gene residing on chromosome 10 approximately 4.5 cM distal to r1. Hopi conditions anthocyanin deposition in aleurone, scutellum, pericarp, root, mesocotyl, leaves, and anthers, thus representing one of the broadest specifications of pigmentation pattern reported to date of all the r1 genes. A unique feature of the Hopi gene is that seeds are completely devoid of pigment at maturity but show a photoinducible germination-dependent anthocyanin accumulation in aleurone and scutellum. Our analysis has shown that the Hopi transcript is not present in scutellum of developing seeds but is induced only upon germination and that the simultaneous presence of both C1 and Hopi mRNAs is necessary to achieve A1 activation in scutella. We conclude that the expression pattern of the Hopi gene accounts for the germination-dependent anthocyanin synthesis in scutella, whereas the developmental competence of germinating seeds to induce anthocyanin production in scutella results from the combination of the light-inducible expression of C1 and the developmentally regulated expression of the Hopi gene.

Endogenous risk factors for deep-vein thrombosis in patients with acute spinal cord injuries.

STUDY DESIGN: Case-control study. AIM OF THE STUDY: Investigate the presence of additional endogenous risk factors of deep-vein thrombosis (DVT). SETTING: Regional Spinal Unit of Florence, Italy. METHODS: A total of 43 patients with spinal lesion and a history of DVT during the acute stage of their neurological impairment (Group A) were comprehensively evaluated and the blood concentrations of the following risk factors, that are presumably associated with DVT, were determined: antithrombin III (ATIII), protein C (PC), protein S (PS), factor V Leiden, gene 200210A polymorphism, homocysteine (Hcy), inhibitor of plasminogen activator-1 (PAI-1) and lipoprotein A (LpA). The control group (Group B) consisted of 46 patients matched to Group A for sex, age, neurological status and prophylactic treatment during the acute stage, with no history of DVT. Statistical analysis was performed using the Mann-Whitney and Fisher's exact tests. RESULTS: Of the individuals in Group A, 14% had no risk factor and 86% had at least one; however, in Group B 54% had no endogenous risk factors and 46% had at least one. None of the individuals in either group had a deficit in their coagulation inhibitors (ATIII, PC and PS), and the LpA level was equivalent in the two groups. The levels of Hcy and PAI-1 were significantly higher in Group A. CONCLUSIONS: Increases in the levels of plasma Hcy and PAI-1 are demonstrated to be independent risk factors for developing a DVT.

[Intracardial knotting of a Swan-Ganz catheter. Description of a clinical case]. / Annodamento intracardiaco del catetere di Swan-Ganz. Descrizione di un caso clinico.

A 79 year old female was admitted to CTO Intensive Care Unit in the immediate postoperative period of orthopedic surgery. A Swan-Ganz fiber optic catheter was inserted through the right internal jugular vein but it was not possible to obtain a satisfactory tracing off pulmonary artery occlusion pressure. We experienced a remarkable trouble to withdraw the catheter in order to repeat the insertion. A chest-X-ray was performed and it showed a knot of the catheter in the right ventricle. It was possible to extract the knotted catheter through original venotomy so avoiding surgery. We want to emphasize that it is of fundamental importance in the insertion of the Swan-Ganz catheter to respect the recommended distances and to avoid repeated attempts to advance and withdraw the catheter.

Primary prevention of deep venous thrombosis and pulmonary embolism in acute spinal cord injured patients.

STUDY DESIGN: Prospective clinical trial. OBJECTIVES: To evaluate the efficacy of a specific protocol for prevention of thrombo-embolic disease occurring during the acute stage of spinal cord lesions, based on the simultaneous use of pharmacological plus mechanical procedures. SETTING: Regional Spinal Unit of Florence, Italy. INTRODUCTION: Deep venous thrombosis (DVT) is a dangerous pathology whose first clinical sign can be represented by unexpected pulmonary embolism (PE). Its incidence in acute spinal cord injured (SCI) patients is reported to range between 9% and 90%. Its prevention represents one of the major challenges for the clinicians involved in the care of such patients. METHOD: Two hundred and seventy-five SCI patients consecutively admitted to our Centre were investigated by colour doppler ultrasonography of lower limbs and pelvis on admission, after 30-45 days and whenever clinically requested. Subcutaneous Nadroparine, a low molecular weight heparin (LMWH), plus early mobilisation, permanently dressed gradient elastic stockings (PGES), and external sequential pneumatic compression (ESPC) of the lower limbs, applied during the first 30 days after injury, were given to all of them. Colour doppler ultrasonography (CDUS) complete investigations of the lower limbs and pelvis were performed on admission, after 30-45 days and whenever clinically requested. The patients were divided into two groups according to their time interval from injury to the admission to our Centre. RESULTS: The incidence of detected DVT was 2% in those patients (99) admitted early to our centre (within 72 h from the trauma), who immediately received our prophylactic protocol. No PE was reported. The other group of patients (176), all admitted between 8 and 28 days (mean 12 days) developed DVT in 26% of cases. None of these patients received ESPC before being admitted to our Centre. No patient had been admitted between 3 and 8 days interval time post injury. CONCLUSION: Early application of pharmacological plus mechanical treatment for DVT prevention produces a marked reduction in such complications. It also reduces the risks of morbidity and mortality in our patients, and, not least, reduces the hospitalization costs during the early period of rehabilitation.

Transcriptional repression by AtMYB4 controls production of UV-protecting sunscreens in Arabidopsis.

An Arabidopsis thaliana line that is mutant for the R2R3 MYB gene, AtMYB4, shows enhanced levels of sinapate esters in its leaves. The mutant line is more tolerant of UV-B irradiation than wild type. The increase in sinapate ester accumulation in the mutant is associated with an enhanced expression of the gene encoding cinnamate 4-hydroxylase, which appears to be the principal target of AtMYB4 and an effective rate limiting step in the synthesis of sinapate ester sunscreens. AtMYB4 expression is downregulated by exposure to UV-B light, indicating that derepression is an important mechanism for acclimation to UV-B in A.thaliana. The response of target genes to AtMYB4 repression is dose dependent, a feature that operates under physiological conditions to reinforce the silencing effect of AtMYB4 at high activity. AtMYB4 works as a repressor of target gene expression and includes a repression domain. It belongs to a novel group of plant R2R3 MYB proteins involved in transcriptional silencing. The balance between MYB activators and repressors on common target promoters may provide extra flexibility in transcriptional control.

Function search in a large transcription factor gene family in Arabidopsis: assessing the potential of reverse genetics to identify insertional mutations in R2R3 MYB genes.

More than 92 genes encoding MYB transcription factors of the R2R3 class have been described in Arabidopsis. The functions of a few members of this large gene family have been described, indicating important roles for R2R3 MYB transcription factors in the regulation of secondary metabolism, cell shape, and disease resistance, and in responses to growth regulators and stresses. For the majority of the genes in this family, however, little functional information is available. As the first step to characterizing these genes functionally, the sequences of >90 family members, and the map positions and expression profiles of >60 members, have been determined previously. An important second step in the functional analysis of the MYB family, through a process of reverse genetics that entails the isolation of insertion mutants, is described here. For this purpose, a variety of gene disruption resources has been used, including T-DNA-insertion populations and three distinct populations that harbor transposon insertions. We report the isolation of 47 insertions into 36 distinct MYB genes by screening a total of 73 genes. These defined insertion lines will provide the foundation for subsequent detailed functional analyses for the assignment of specific functions to individual members of the R2R3 MYB gene family.