FLUChallenge: an innovative strategy to increase flu vaccination in two Italian Teaching Hospitals

In Europe flu vaccination among healthcare workers (HCWs) is strongly recommended even though not mandatory such as elsewhere (USA). Despite this, vaccination coverage in EU countries is usually low: 30.2% in 2016-17. In Italy, at the end of the same season it was 15.6%. Aim of this study is to describe and evaluate the new strategy adopted by Gemelli and Humanitas Research Hospitals, two Italian Teaching Hospitals (THs) part of the MIRO Public Health Center, to increase the vaccination coverage among their HCWs.

Before the 2019-20 campaign, experts of the two THs met up to identify a common strategy to promote flu vaccination among HCWs in addition to the ones already implemented. It was decided to launch a FLUChallenge: a platform of monitoring updated bi-weekly and available on the THs' internal websites with the vaccination coverage overall and stratified by job category and macro-areas of activity. Descriptive and inferential analysis were performed.

Preliminary Results

6673 HCWs included (4241 Gemelli, 2432 Humanitas). The overall flu vaccination coverage at the end of the 2019-20 campaign was 28.4% (1026 HCWs vaccinated Gemelli, equal to 24.2%; 869 HCWs vaccinated Humanitas, 35.7%). Both THs significantly increased the vaccination coverage compared to the previous year (+10% Gemelli, 22% in 2018-19, p = 0.01; +45.7% Humanitas, 24.5% in 2018-19, p < 0.001). Physicians had the highest coverage both in Gemelli (483/1320, 36.6%) and Humanitas (443/979, 45.2%), while the lowest was registered among nurses in Gemelli (357/2017, 17.7%) and other HCWs in Humanitas (134/605, 22.1%). Infectious disease was the macro-area with highest coverage in Gemelli (32.3%), while in Humanitas the emergency department (63.9%).

The FLUChallenge intervention was an effective strategy to increase flu vaccination coverage in the two TH. The website platform was useful for the purpose of accountability and able to create a positive challenge between the HCWs working in the two THs involved.

Key messages

Flu vaccination among healthcare workers (HCWs) is recommended to prevent influenza and to avoid its transmission. It is important to promote new engagement and innovative strategies to increase flu vaccination coverage among HCWs, when it is not mandatory.

Evaluation and cost estimation of laboratory tests overuse through a CCDSS in a university hospital

Computerized Clinical Decision Support Systems (CCDSS) are information technology-based systems that use specific patient characteristics and combine them with rule-based algorithms. The aim of this study is to conduct a survey to measure and assess the over-utilization rates of laboratory requests and to estimate the monthly cost of inappropriate requests in inpatients of the “Fondazione Policlinico Universitario A. Gemelli IRCCS” Care Units.

This observational study is based on the count of rules violations for 43 different types of laboratory tests requested by the Hospital physicians, for a total of 5,716,370 requests, over a continuous period of 20 months (from 1 July 2016 to 28 February 2018). Requests from all the hospital internal departments (except for Emergency, Intensive Care Units and Urgent requests) were monitored. The software intercepted and counted, in silent mode for the operator, all requests and violations for each laboratory test among those identified.

During the observation period a mean of 285,819 requests per month were analyzed and 40,462 violations were counted. The global rate of overuse was 15.2% ± 3.0%. The overall difference among sub-groups was significant (p < 0.001). The most inappropriate exams were Alpha Fetoprotein (85.8% ± 30.5%), Chlamydia trachomatis PCR (48.7% ± 8.8%) and Alkaline Phosphatase (20.3% ± 6.5%). All the exams, globally considered, generated an estimated avoidable cost of 1,719,337€ (85,967€ per month) for the hospital.

This study reports rates (15.2%) similar to other works. The real impact of inappropriateness is difficult to assess, but the generated costs for patients, hospitals and health systems are certainly high and not negligible.

Key messages

It would be desirable for international medical communities to produce a complete panel of prescriptive rules for all the most common laboratory exam. That is useful not only to reduce costs, but also to ensure standardization and high-quality care.

Flu vaccination coverage in a large Italian teaching hospital: the example of the leaders

Key messages

Annual flu vaccination among healthcare workers (HCWs) is recommended to prevent influenza and to avoid its transmission especially to frail patients. This study shows the growing flu vaccination coverage rate in our teaching hospital and the effectiveness of the example given by the vaccinated leaders in increasing the coverage among all HCWs.

A six-years point prevalence survey of healthcare-associated infections in an Italian hospital

Key messages

Point prevalence from 2013 to 2018 seems to be stable. An accurate incidence survey is needed in order to identify the main risk factors of HAI and to realize more specific hospital programmes. Length of stay at the moment of detection is useful to meaningfully predict HAIs prevalence although the cause-and-effect relationship is still not clear.

Incidence study of surgical site infections in a large University Hospital in Rome, first results

Background

Surgical Site Infections (SSI) represent about a quarter of healthcare associated infections (HAI), increase the risk of mortality and hospital stay and extend healthcare costs. The aim of this work is to evaluate the incidence of SSI in patients undergoing surgical procedures of Hospital Units in the Fondazione Policlinico A. Gemelli IRCCS (FPG).

Methods

This descriptive observational monocentric study has a 30-months duration: the first phase was conducted between July 2018 and March 2019. Patients undergoing abdominal surgery procedures were enrolled. Active infection surveillance was performed, according to the ECDC, during the hospital stay and the surgical outpatient visits. We also performed a post-discharge surveillance (PDS) at 30 days (or 90 days if an implant has been inserted), through a telephone interview, made by a medical doctor resident in Public Health.

Results

During the first phase were enrolled 431 procedures in 2 Hospital Units, about emergency and hepatobiliary surgery. There were 53 cases of surgical site infection (SSI) highlighted in these procedures. Therefore, SSI’s were reported in 12.09% of the procedures. In particular, in 6.28% of cases, SSIs were diagnosed during the hospital stay. The results of this study showed statistically significant differences (p < 0.005) in incidence rate of emergency (10,70%) and hepatobiliary tract (13,17%) procedures. The average hospital stay was significant higher (p < 0.001) in patients who developed an SSI (17.27 days) than in patients without SSI (4.89 days).

Conclusions

These preliminary results show that the incidence rate of SSI for gastrointestinal procedures is similar to other European Countries (9.6%). The Hospital Health Management of FPG take care to the surveillance of hospital infections and monitor the correct application of the procedures, in line with the standards defined by Joint Commission International for guarantee high level in patients’ care.

Key messages

Performing a survey to measure the incidence of surgical site infections for surgery procedures is very important to define it and to improve surveillance systems of hospital infections in FPG. Active surveillance of surgical site infections may allow to enhance appropriate preventive measures.

Studying the Evolution of the Vertebrate Circadian Clock: The Power of Fish as Comparative Models

The utility of any model species cannot be judged solely in terms of the tools and approaches it provides for genetic analysis. A fundamental consideration is also how its biology has been shaped by the environment and the ecological niche which it occupies. By comparing different species occupying very different habitats we can learn how molecular and cellular mechanisms change during evolution in order to optimally adapt to their environment. Such knowledge is as important as understanding how these mechanisms work. This is illustrated by the use of fish models for studying the function and evolution of the circadian clock. In this review we outline our current understanding of how fish clocks sense and respond to light and explain how this differs fundamentally from the situation with mammalian clocks. In addition, we present results from comparative studies involving two species of blind cavefish, Astyanax mexicanus and Phreatichthys andruzzii. This work reveals the consequences of evolution in perpetual darkness for the circadian clock and its regulation by light as well as for other mechanisms such as DNA repair, sleep, and metabolism which directly or indirectly are affected by regular exposure to sunlight. Major differences in the cave habitats inhabited by these two cavefish species have a clear impact on shaping the molecular and cellular adaptations to life in complete darkness.

Transcriptional regulation of arylalkylamine-N-acetyltransferase-2 gene in the pineal gland of the gilthead seabream

Pineal serotonin-N-acetyltransferase (arylalkylamine-N-acetyltransferase; AANAT) is considered the key enzyme in the generation of circulating melatonin rhythms; the rate of melatonin production is determined by AANAT activity. In all the examined species, AANAT activity is regulated at the post-translational level and, to a variable degree, also at the transcriptional level. Here, the transcriptional regulation of pineal aanat (aanat2) of the gilthead seabream (Sparus aurata) was investigated. Real-time polymerase chain reaction quantification of aanat2 mRNA levels in the pineal gland collected throughout the 24-h cycle revealed a rhythmic expression pattern. In cultured pineal glands, the amplitude was reduced, but the daily rhythmic expression pattern was maintained under constant illumination, indicating a circadian clock-controlled regulation of seabream aanat2. DNA constructs were prepared in which green fluorescent protein was driven by the aanat2 promoters of seabream and Northern pike. In vivo transient expression analyses in zebrafish embryos indicated that these promoters contain the necessary elements to drive enhanced expression in the pineal gland. In the light-entrainable clock-containing PAC-2 zebrafish cell line, a stably transfected seabream aanat2 promoter-luciferase DNA construct exhibited a clock-controlled circadian rhythm of luciferase activity, characteristic for an E-box-driven expression. In NIH-3T3 cells, the seabream aanat2 promoter was activated by a synergistic action of BMAL/CLOCK and orthodenticle homeobox 5 (OTX5). Promoter sequence analyses revealed the presence of the photoreceptor conserved element and an extended E-box (i.e. the binding sites for BMAL/CLOCK and OTX5 that have been previously associated with pineal-specific and rhythmic gene expression). These results suggest that seabream aanat2 is a clock-controlled gene that is regulated by conserved mechanisms.

Zebrafish arylalkylamine-N-acetyltransferase genes - targets for regulation of the circadian clock

Daily rhythms of melatonin production are controlled by changes in the activity of arylalkylamine-N-acetyltransferase (AANAT). Zebrafish possess two aanats, aanat1 and aanat2; the former is expressed only in the retina and the latter is expressed in both the retina and the pineal gland. Here, their differential expression and regulation were studied using transcript quantification and transient and stable in vivo and in vitro transfection assays. In the pineal gland, the aanat2 promoter exhibited circadian clock-controlled activity, as indicated by circadian rhythms of Enhanced green fluorescent protein (EGFP) mRNA in AANAT2:EGFP transgenic fish. In vivo transient expression analyses of the aanat2 promoter indicated that E-box and photoreceptor conserved elements (PCE) are required for expression in the pineal gland. In the retina, the expression of both genes was characterized by a robust circadian rhythm of their transcript levels. In constant darkness, the rhythmic expression of retinal aanat2 persisted while the aanat1 rhythm disappeared; indicating that the former is controlled by a circadian clock and the latter is also light driven. In the light-entrainable clock-containing PAC-2 zebrafish cell line, both stably transfected aanat1 and aanat2 promoters exhibited a clock-controlled circadian rhythm, characteristic for an E-box-driven expression. Transient co-transfection experiments in NIH-3T3 cells revealed that the two, E-box- and PCE-containing, promoters are driven by the synergistic action of BMAL/CLOCK and orthehodenticle homeobox 5. This study has revealed a shared mechanism for the regulation of two related genes, yet describes their differential phases and photic responses which may be driven by other gene-specific regulatory mechanisms and tissue-specific transcription factor profiles.

Effect of the New York State cigarette fire safety standard on ignition propensity, smoke constituents, and the consumer market

OBJECTIVES

This study examines empirical evidence from the New York experience testing tobacco industry arguments made in opposition to fire safety standards for cigarettes.

DESIGN

Percentages of cigarettes exhibiting full length burns (FLBs), cigarette sales before and following the implementation of the New York standards, a sample of retail cigarette prices, brand availability, and selected smoke constituent yields were compared between cigarettes sold in New York and two other states. Cigarette paper analysis was conducted on cigarettes sold in New York.

RESULTS

New York cigarette brands averaged 10.0% FLBs as compared to 99.8% for California and Massachusetts brands. Reduced ignition propensity (RIP) appears to have been achieved by cigarette paper banding. Cigarette sales, prices, and brand availability do not appear to have been affected by the New York standards. Yields of the majority of smoke constituents tested did not differ substantially between RIP cigarettes sold in New York as compared to the same brands sold in Massachusetts. Average yields of tar, carbon monoxide, and two compounds were slightly higher, the yields of seven compounds were higher for one brand only, and nicotine was lower, among New York brands tested.

CONCLUSIONS

RIP cigarette brands have been designed to meet the New York fire safety standards. Their introduction has not affected cigarette sales or prices in New York. There is no evidence that the small increases in smoke constituent yields affect the already highly toxic nature of cigarette smoke. Data on smoking caused fires, deaths, and injuries dating from after the change in law are not yet available. Such data will be able to address the question of whether the demonstrated reduced ignition standards are associated with reduced fires and injuries. Based on the New York experience, prior industry objections to producing RIP cigarettes are unfounded. Other states and nations should adopt similar standards.

Activity, non-selective attention and emotionality in dopamine D2/D3 receptor knock-out mice

In order to assess the role of dopamine (DA) D2 and D3 receptors in the modulation of behaviour, we analysed exploration in a spatial novelty in mouse model systems. Genetically engineered mice mutants have been used that carry normal, partial or no expression of D2R, D3R, or both D2R/D3R (double mutants) DA receptor subtypes. Adult male mice were exposed for 30 min to a Làte-maze. The behaviour was analysed for indices of activity, orienting (rearing frequency), scanning times (rearing duration) and defecation score (emotionality). D2R - / - and + / - as well as the D2R/D3R double homozygous mutants were less active than wild-type (WT) controls in travelled distance. In contrast D3R + / - were more active than WT mice in the first part of the test. As to orienting frequency, the D2R - / - were less active than WT during the entire test-period, whereas the D2 + / - mutants were less active than WT only in the second part of the test. Moreover, the D3R - / - and + / - mutants showed less and more rearing frequency than WT, respectively, during the entire test. Finally, the D2/D3R - / - double mutants were also less active than WT during the entire test period. As to scanning times, D2R + / - and - / - mutants were higher than WT during the entire test or only in the second part, respectively. The D3R + / - and - / - were not different from WT, whereas the D2/D3R - / - double mutants showed shorter scanning times only in the first part of the test. As to emotionality index, the defecation score, was lower only in D3R + / - mutants. Thus, the dopamine D2 and D3 receptor subtypes appear to be differentially involved in the modulation of activity, orienting and scanning phases of attention. Lastly double mutation experiments reveal an interaction between D2R and D3R with the former prevailing on the latter.

Neuroprotective role of dopamine against hippocampal cell death

Glutamate excitotoxicity plays a key role in the induction of neuronal cell death occurring in many neuropathologies, including epilepsy. Systemic administration of the glutamatergic agonist kainic acid (KA) is a well characterized model to study epilepsy-induced brain damage. KA-evoked seizures in mice result in hippocampal cell death, with the exception of some strains that are resistant to KA excitotoxicity. Little is known about the factors that prevent epilepsy-related neurodegeneration. Here we show that dopamine has such a function through the activation of the D2 receptor (D2R). D2R gene inactivation confers susceptibility to KA excitotoxicity in two mouse strains known to be resistant to KA-induced neurodegeneration. D2R-/- mice develop seizures when administered KA doses that are not epileptogenic for wild-type (WT) littermates. The spatiotemporal pattern of c-fos and c-jun mRNA induction well correlates with the occurrence of seizures in D2R-/- mice. Moreover, KA-induced seizures result in extensive hippocampal cell death in D2R-/- but not WT mice. In KA-treated D2R-/- mice, hippocampal neurons die by apoptosis, as indicated by the presence of fragmented DNA and the induction of the proapoptotic protein BAX. These results reveal a central role of D2Rs in the inhibitory control of glutamate neurotransmission and excitotoxicity.

Topographical evaluation of behavioural phenotype in a line of mice with targeted gene deletion of the D2 dopamine receptor

The phenotype of spontaneous and dopamine D2-like agonist-induced behaviour was assessed topographically in a line of mice with targeted gene deletion of the D1 receptor. An ethologically-based, rapid time-sampling behavioural check-list technique was used to resolve and quantify all behaviours in the natural repertoire of the mouse. Relative to wildtypes [D2+/+], D2-null [D2-/-] mice evidenced over a 1 h period of initial exploration modest but significant reductions in locomotion, grooming, rearing free and rearing to wall; rearing seated, sniffing, sifting and stillness were not altered. Individual elements of behaviour habituated similarly over a 6 h period for both genotypes. The dose-dependent induction of stereotyped sniffing and ponderous locomotion by the D2-like agonist RU 24213 (0.1-12.5 mg/kg) in wildtypes was essentially absent in D2-null mice. The ethogram of spontaneous behaviour in D2-null mice was characterised by only modest reductions in, and topographical shifts between, certain individual elements of behaviour. Essential abolition of D2-like agonist responsivity in D2-null mice vis-à-vis considerable preservation of spontaneous behavioural topography suggests compensatory processes subsequent to developmental absence of the D2 receptor that are able to sustain function under naturalistic, tonic conditions but not during phasic challenge.

Structure and function of dopamine receptors

Dopamine (DA) is the most abundant catecholamine in the brain. The involvement and importance of DA as a neurotransmitter in the regulation of different physiological functions in the central nervous system (CNS) is well known. Deregulation of the dopaminergic system has been linked with Parkinson's disease, Tourette's syndrome, schizophrenia, attention deficit hyperactive disorder (ADHD) and generation of pituitary tumours. This review focuses on the pharmacological and biochemical features shared by the dopamine receptors. We address their coupling to secondary messenger pathways and their physiological function based upon studies using pharmacological tools, specific brain lesions and, more recently, genetically modified animal models.

The adolescent years: an academic-community partnership in Harlem comes of age

Much has been written about the potential benefits in health promotion that are possible through partnerships between academic institutions and community-based organizations, but little practical advice has been provided on how to sustain these relationships when the original grant funds have been exhausted. Here we document our experiences in Harlem, New York City, a community with grave social, structural, and physical environmental inequities, and describe the successes and failings of a partnership now in its "adolescence" between researchers at the Joseph L. Mailman School of Public Health of Columbia University and community activists at West Harlem Environmental Action (WE ACT).

Role of distinct mitogen-activated protein kinase pathways and cooperation between Ets-2, ATF-2, and Jun family members in human urokinase-type plasminogen activator gene induction by interleukin-1 and tetradecanoyl phorbol acetate

We have investigated the in vivo and in vitro regulation of the human urokinase-type plasminogen activator (uPA) gene by interleukin-1 (IL-1) and analyzed the transcription factors and signalling pathways involved in the response of the -2.0-kb uPA enhancer to IL-1 induction and to tetradecanoyl phorbol acetate (TPA) induction. Mutational analysis showed the cooperative activity of the Ets-binding site (EBS) and the two AP-1 elements of the enhancer. The results reveal that the EBS is required for the response to both inducers mediated by Ets-2, which is regulated at a level subsequent to DNA binding, by an IL-1- and phorbol ester-inducible transactivation domain. Both the IL-1 and the TPA-mediated induction result in a drastic increase of AP-1 binding to the downstream site of the enhancer (uPA 3' TPA-responsive element), while a mostly qualitative change, resulting from the interplay between ATF-2 homodimers and c-Jun-ATF-2 heterodimers, takes place at the upstream AP-1 element. The analysis of two distinct mitogen-activated protein kinase pathways shows that stress-activated protein kinase-Jun N-terminal kinase activation, resulting in the phosphorylation of ATF-2, c-Jun, and JunD, is required not only for the IL-1- but also for the TPA-dependent induction, while the extracellular signal-related kinase 1 (ERK-1) and ERK-2 activation is involved in the TPA- but not in the IL-1-dependent stimulation of the uPA enhancer.

Increase in AP-1 activity is a general event in thyroid cell transformation in vitro and in vivo

We have recently reported that neoplastic transformation of two rat thyroid epithelial cell lines by retroviruses carrying the v-mos and v-ras Ki oncogenes is associated with a drastic increase of AP-1 activity. The most important effects were represented by the dramatic junB and fra-1 gene induction, which was abolished by the block of the transformation-induced HMGI-C protein synthesis. Here, we have further characterized the transformation-dependent AP-1 activity, by analysing the expression of different jun- and fos-related components, in rat thyroid cell lines transformed by several oncogenes, in human thyroid carcinoma cell lines, and in naturally occurring human thyroid tumours. A significant increase of Fra-1 and JunB protein levels was detected in all oncogene transformed rat thyroid cell lines. Fra-1 gene induction was demonstrated to occur also in human thyroid carcinoma cell lines and tissues. Conversely, c-Jun and JunD proteins, rather than JunB, accumulated in human thyroid carcinoma cell lines. An induction of AP-1 target genes was also detected both in rat and human thyroid transformed cell lines. Therefore, in vivo and in vitro thyroid cell transformation is associated with important compositional changes in the AP-1 complex and an increased transcriptional activity.

Behavioural sensitization in 6-hydroxydopamine-lesioned rats is related to compositional changes of the AP-1 transcription factor: evidence for induction of FosB- and JunD-related proteins

Rats with unilateral dopamine denervation exhibit turning behaviour in response to the selective D1 agonist SKF 38393 only after a previous exposure to dopamine agonists. We demonstrate here that this 'priming' phenomenon is related to both an increased expression of the pre-existing AP-1 complex and the occurrence of novel AP-1 complexes which are formed by FosB- and JunD-related proteins. While the former protein is expressed as a consequence of the dopamine denervation, the latter is related to the first exposure to a dopamine agonist. Pre-treatment with MK-801, an antagonist for glutamatergic receptors, prevents both the priming development and the AP-1 compositional changes. Rotational behaviour induced by SKF 38393 closely correlates with the presence of the priming AP-1 complexes, regardless of the capability of the D1 agonist to induce the immediate-early gene cFos.

Neoplastic transformation of rat thyroid cells requires the junB and fra-1 gene induction which is dependent on the HMGI-C gene product

The expression of the high mobility group I (HMGI)-C chromatin component was shown previously to be essential for the establishment of the neoplastic phenotype in retrovirally transformed thyroid cell lines. To identify possible targets of the HMGI-C gene product, we have analyzed the AP-1 complex in normal, fully transformed and antisense HMGI-C-expressing rat thyroid cells. We show that neoplastic transformation is associated with a drastic increase in AP-1 activity, which reflects multiple compositional changes. The strongest effect is represented by the dramatic junB and fra-1 gene induction, which is prevented in cell lines expressing the antisense HMGI-C. These results indicate that the HMGI-C gene product is essential for the junB and fra-1 transcriptional induction associated with neoplastic transformation. The inhibition of Fra-1 protein synthesis by stable transfection with a fra-1 antisense RNA vector significantly reduces the malignant phenotype of the transformed thyroid cells, indicating a pivotal role for the fra-1 gene product in the process of cellular transformation.

Heterodimerization of c-Jun with ATF-2 and c-Fos is required for positive and negative regulation of the human urokinase enhancer

Dimerization plays a pivotal role in modulating the activity of the c-Jun proto-oncogene product. Heterodimerization with activating transcription factor-2 (ATF-2) alters the DNA-binding specificity of c-Jun, allowing its targeting to several cAMP responsive element (CRE)-related sequences, which control a subset of AP-1-responsive genes. Here we show that a c-Jun/ATF-2 heterodimer binds to the AP-1 site (uPA 5'-TRE) essential for the activity of the human urokinase enhancer, conferring on this element several distinctive regulatory properties. The c-Jun/ATF-2 heterodimer was identified by binding competition assays, u.v. cross linking, and monospecific antibodies. In vitro binding studies revealed that the uPA 5'-TRE sequence is recognized by the cyclic AMP-unresponsive ATF-2 factor, but not by the cyclic AMP-inducible CREB. In addition, in vivo studies suggest that ATF-2 can mediate, at the same time, the activation of the c-Jun/ATF-2 site and the repression of the canonical collagenase AP-1 site. We report that heterodimerization with c-Fos does not increase the binding of c-Jun to the uPA 5'-TRE, in contrast to the increased binding at a consensus AP-1 site. Our data further suggest that c-Fos can act as a repressor of the c-Jun/ATF-2 binding site, revealing an important functional difference, with respect to canonical AP-1 elements.

Glucose 6-phosphate dehydrogenase deficiency and red cell membrane defects: additive or synergistic interaction in producing chronic haemolytic anaemia

We have investigated two unrelated patients with congenital haemolytic anaemia in both of whom we found a combination of hereditary spherocytosis (HS) and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Segregation of the two defects was documented in both families, who had different molecular abnormalities for both HS and G6PD deficiency. In one family the propositus had a reduced level of spectrin and G6PD Seattle (282Asp-->His). In the other family the propositus had a band 3 abnormality and was heterozygous for G6PD Mediterranean (188Ser-->Phe). From a comparison of clinical and haematological findings in family members with either or both abnormalities we conclude that in one case the two defects exhibited a synergistic effect, resulting in a severe chronic haemolytic anaemia; whereas in the other the association was simply additive.

Modulation of auxin-binding proteins in cell suspensions : II. Isolation and initial characterization of carrot cell variants impaired in somatic embryogenesis

Cultured cell lines from carrot (Daucus carota L.) with little or no embryogenic potential were examined for the auxin-binding capacity of their membranes. The lines belonged to different classes: (a) wild-type lines kept in culture for different periods (the longer the period, the lower being their embryogenic potential); (b) variants, isolated after mutagenesis, showing normal growth but a lack of embryogenic response; (c) auxin-resistant lines, isolated as colonies on solid media containing 45 μM 2,4-D; (d) a previously described tumorous line (E9) isolated because of its resistance to hypomethylating drugs. All of these lines showed alterations in auxin-induced, auxin-binding capacity (modulation), i.e. in the non-embryogenic lines the addition of auxin increased the auxinbinding capacity to a very small degree, or removal of the hormone did not produce the proper decrease in that capacity, or both defects could be simultaneously present. Both types of defects were shown to be correctable: after treatments designed to increase the amplitude of modulation, embryogenic capacity was restored in a number of lines.

Molecular basis of chronic non-spherocytic haemolytic anaemia: a new G6PD variant (393 Arg----His) with abnormal KmG6P and marked in vivo instability

More than 80 genetic variants of glucose-6-phosphate dehydrogenase (G6PD) are associated with chronic non-spherocytic haemolytic anaemia (CNSHA). In order to help clarify the molecular basis of this association, we have carried out a detailed biochemical and genetic characterization of two G6PD deficient brothers affected by CNSHA. The G6PD from the two patients has altered electrophoretic mobility, abnormally elevated Michaelis constant (Km) for G6P, and extreme instability in vivo and in vitro. By comparison with published information we found that this is a new G6PD variant which we have designated G6PD Portici. The entire coding region of the gene has been sequenced, and a single point mutation, a G----A transition, was found at position 1178 in exon X, causing a substitution of histidine for arginine at residue 393 in the polypeptide chain. By polymerase chain reaction (PCR) amplification followed by diagnostic restriction enzyme analysis and allele-specific oligonucleotide hybridization we have demonstrated the inheritance of this mutation in the patient's family. Our results support the notion of a causative link between this mutation in the G6PD gene and CNSHA. Our data, in combination with previous data in the literature, suggest that the three-dimensional structure of G6PD is such as to cause interaction in the binding of its two substrates, G6P and NADP.

Modulation of auxin-binding proteins in cell suspensions : I. Differential responses of carrot embryo cultures

This paper shows that the level of 2,4-dichlorophenoxyacetic acid (2,4-D) in the medium determines the level of auxin-binding proteins in the membranes of carrot, Daucus carota, cells grown in suspension. This induction takes slightly more than 2 hours to complete and can be elicited by natural as well as synthetic auxins. The auxin binding sites thus generated, which are pronase-sensitive, bind 2,4-D, indoleacetic acid, and naphthalene-acetic acid (NAA) equally well. However both alpha- and beta-NAA bind, whereas only alpha-NAA is effective in the inductive process. Cells committed to embryogeny (proembryogenic masses) do not respond to auxin, i.e. their level of auxin-binding proteins remains very low, and they do not seem to synthesize the hormone, as indicated by inhibitor studies. Sensitivity to, and production of, auxin, begins when the embryo becomes polarized, i.e. at postglobular stage.

Genetic heterogeneity at the glucose-6-phosphate dehydrogenase locus in southern Italy: a study on a population from the Matera district

Glucose-6-phosphate dehydrogenase (G6PD) has been analyzed by gel electrophoresis and by quantitative assay in an unselected sample of 1524 schoolboys from the province of Matera (Lucania) in southern Italy. We have identified 43 subjects with a G6PD variant. Of these, 31 had severe G6PD deficiency, nine had mild to moderate deficiency, and three had a non-deficient electrophoretic variant. The overall rate of G6PD deficiency was 2.6%. The frequency of G6PD deficiency, ranging from 7.2% on the Ionian Coast to zero on the eastern side of the Lucanian Apennines, appears to be inversely related to the distance of each town examined from the Ionian Coast, suggesting that this geographic distribution may reflect, at least in part, gene flow from Greek settlers. Biochemical characterization has shown that most of the G6PD deficiency in this population is accounted for by G6PD Mediterranean. In addition, we have found several examples of two other known polymorphic variants (G6PD Cagliari and G6PD A-); three new polymorphic variants, G6PD Metaponto (class III), G6PD Montalbano (class III), and G6PD Pisticci (class IV); and two sporadic variants, G6PD Tursi (class III) and G6PD Ferrandina (class II). These data provide further evidence for the marked genetic heterogeneity of G6PD deficiency within a relatively narrow geographic area and they prove the presence in the Italian peninsula of a gene (GdA-) regarded as characteristically African.

Common glucose-6-phosphate dehydrogenase (G6PD) variants from the Italian population: biochemical and molecular characterization

By biochemical characterization of glucose-6-phosphate dehydrogenase (G6PD) from the red cells of seventeen subjects of the population of Matera (Southern Italy) we have identified six genetically determined common variants. Among these, G6PD Metaponto and G6PD A(-) Matera had been already fully characterized. We have now found that A(-) Matera is genetically heterogeneous since one of two subjects examined had the two mutations at codons 68 and 126 characteristic of a typical A(-) variant, while the other subject had only the codon 126 mutation. G6PD Pisticci and G6PD Tursi are two new variants whose molecular lesion is not yet known. G6PD Cagliari-like has biochemical characteristics reminiscent of G6PD Cagliari, isolated in Sardinia, and was found to have the same nucleotide substitution as G6PD Mediterranean. G6PD Montalbano is a new variant, with nearly normal properties, due to a G----A transition which causes an Arg----His amino acid replacement at position 285.