1,721,176 research outputs found
Physiological and transcriptional characterization of response to N-starvation in roots of two maize inbred lines with different nitrogen use efficiency
No full textL'azoto (N) è l'elemento richiesto in quantità maggiori dalle piante dopo il carbonio (C) ed è un costituente principale di acidi nucleici, proteine, coenzimi, fitormoni, clorofilla e metaboliti secondari. La biodisponibilità di questo elemento è quindi un fattore cruciale per la crescita delle piante e di conseguenza l'uso di fertilizzanti è necessario per la produttività dei sistemi agricoli. Nella maggior parte dei terreni, ammonio e nitrato sono le fonti principali di N disponibili per la nutrizione delle piante. Anche se le concentrazioni medie del primo nel suolo sono spesso 10-1000 volte inferiori a quelle del NO3-, questa differenza non riflette necessariamente il rapporto di assorbimento da parte delle radici. L'assorbimento del NO3- è stato ampiamente studiato, mentre meno informazioni sono invece disponibili per NH4+. Precedenti studi condotti su riso, abete rosso e Arabidopsis hanno rivelato l'esistenza di due sistemi di trasporto per NH4 + con alta (HATS) e bassa (LATS) affinità. Dal momento che le informazioni riguardanti gli aspetti molecolari dell'assorbimento dell' NH4+ in mais sono molto limitate, in questo lavoro ne abbiamo caratterizzato alcuni aspetti biochimici in due linee pure di mais (LO5 e T250). Queste due linee sono state studiate in esperimenti di campo, determinando la differente efficienza di uso dell'azoto (NUE), in particolare, una mostra una NUE alta (LO5), mentre l'altra bassa (T250). Queste due linee pure erano già state caratterizzate solamente per l'assorbimento del nitrato in un precedente lavoro, evidenziando l'esistenza di due distinti sistemi di trasporto anche per questa forma azotata. L'analisi dei parametri cinetici dell'assorbimento di ammonio determinate per la prima volta in questo lavoro mostrato una minore Km per la linea ad alta NUE. L'influenza del pH sulla velocità di assorbimento dei sistemi HATS e LATS è stata determinata evidenziando che la velocità di assorbimento non dipende dalla disponibilità di H+. Differenze tra le due linee nel tasso di assorbimento delle due diverse fonti inorganiche di azoto in piante cresciute in carenza dell'elemento sono state studiate. La velocità dell'assorbimento dell'ammonio aumenta in queste condizioni più velocemente nella linea Lo5 mentre la velocità di assorbimento del NO3- tendeva a diminuire in entrambe le linee. Quando i tassi di assorbimento sono stati analizzati quando le due forme (nitrato e ammonio) erano presenti contemporaneamente nella soluzione di assorbimento (rapporto 100: 1), i tassi di assorbimento di NH4 + mostravano livelli simili a quelli del NO3-. Le due linee sono state anche caratterizzate per le loro differenze nei profili trascrizioni della radice durante la crescita in risposta alla N carenza attraverso analisi microarray. I dati ottenuti hanno evidenziato che 112 trascritti erano differenzialmente espressi tra Lo5 e T250 dopo 0, 1 e 4 giorni dall'inizio del trattamento, mentre 85 e 646 trascritti erano differenzialmente espressi sia a 0 e 1 giorni e sia a 1 e 4 giorni, rispettivamente. L'annotazione manuale di questi trascritti differenzialmente espressi e lo studio del loro comportamento nei due linee ci permettono di sostenere l'ipotesi che la linea ad alta NUE (Lo5) risponde alla N carenza rispetto alla linea NUE basso (T250) attraverso una forte espressione di geni che sembrano essere coinvolti nei meccanismi molecolari che mediano la risposta all'assenza di macronutrienti nelle radici.Nitrogen (N) is the element required in greatest amounts by plants after carbon (C) and it is a primary component of nucleic acids, proteins, co-enzymes, phytohormones, chlorophyll and also secondary metabolites which plays extremely important roles for plant life. The bioavailability this element to roots is therefore a crucial factor for plant growth and consequently the use of fertilizers is required to agricultural systems. In most soils, NH4+ and NO3- are the predominant sources of N that are available for plant nutrition. Although the average NH4+ concentrations in soils are often 10-1000 times lower than those of NO3-, this difference does not necessarily reflect the uptake ratio of each N source. The characteristics of root NO3- uptake have been extensively studied. Less information is on the contrary available for NH4+. Previous works performed in rice, spruce and Arabidopsis have revealed the existence of two transport systems for NH4+ with high (HATS) and low (LATS) affinity. Since information regarding molecular aspects of NH4+ uptake in maize is very limited, as a first purpose of this work we characterized some biochemical aspects of NH4+ uptake in seedlings of two maize inbred lines (Lo5 and T250). These two lines were identified in field experiments as a high (Lo5) and low (T250) nitrogen use efficiency (NUE), lines respectively. As far as, the uptake of N mineral forms, the two lines were previously characterized for the difference in HATS and LATS for NO3-. The analysis of kinetics parameters of NH4+ uptake here determined showed a lower Km for the high-NUE line. The influence of pH on the uptake rate on both HATS and LATS was also evaluated showing that the uptake rate is not dependent from H+ availability. Differences between Lo5 and T250 in the uptake rate of the two inorganic N-forms during the growth without N source were analyzed. NH4+ uptake rate increased during N deprivation with a steeper profile in Lo5 whilst NO3- uptake rate tended to decrease in both lines. When the uptake rates were analyzed in the contemporary presence of NO3- and NH4+ in the uptake solution with a 100:1 ratio, the NH4+ uptake rates showed similar levels to those of and NO3-. The two lines were also characterized for their differences in root transcriptional profile during N deprivation through microarray analysis. Data analysis highlighted that 112 transcripts were differentially expressed between Lo5 and T250 at 0, 1 and 4 days of N deprivation, while 85 and 646 transcripts were differentially expressed both at 0 and 1 days and both at 1 and 4 days, respectively. The annotation of these differentially expressed transcripts and the study of their behaviour in the two lines strongly support the idea that the high NUE line responds to N deprivation though a stronger expression of genes known as involved in the molecular mechanisms mediating the response to the absence of the macronutrient in roots relative to the low NUE line (T250)
Jean-Martin Charcot: rheumatology in philately.
No full textIn 1992 , Greenwald presented in an article a small collection of a reumatology related stamps. The 2nd stamp portrays Charcot, a famous neurologist of the 19th century. but Greenwald made a mistake. The stamp illustred by Greenwald portrays Jean Baptiste, the explorer, the son instead of Jean Martin Charcot, the neurologist, the father. Here a brief description of the father’s and son’s lives
Cryoglobulinemic vasculitis.
No full textPURPOSE OF REVIEW: Cryoglobulinemic vasculitis is an immune-complex-mediated systemic vasculitis involving small-medium-sized vessels. A causative role of hepatitis C virus in over 80% patients has been definitively established, with heterogeneous geographical distribution. This review focuses on recent etiopathogenetic, clinico-diagnostic, and therapeutical studies.RECENT FINDINGS: Hepatitis C virus cannot be integrated into the host genome; it may exert a chronic stimulus to the immune system. The interaction between hepatitis C virus envelope protein E2 with B-cell CD 81 receptor may increase the frequency of VDJ rearrangement in antigen-reactive B lymphocytes. One consequence is the activation of various protooncogenes, including anti-apoptotic Bcl-2. The extended B-cell survival is responsible for autoantibody and immune-complex production, including mixed cryoglobulins; some malignancies, mainly B-cell lymphomas, may complicate cryoglobulinemic vasculitis. Environmental or viral/host genetic cofactors should be relevant in the pathogenesis of hepatitis C virus-related diseases. Cryoglobulinemic vasculitis may overlap with other diseases (systemic vasculitides, Sjögren's syndrome, autoimmune hepatitis, lymphoma), which should be carefully considered for a correct diagnosis and treatment. Cumulative survival of cryoglobulinemic vasculitis is significantly lower compared with the general population. Therapeutic strategies for cryoglobulinemic vasculitis include etiologic (antiviral), pathogenetic (cyclophosfamide, rituximab), or symptomatic (steroids, plasmapheresis) treatments, which should be tailored to the individual patient according to the severity/activity of clinical symptoms.SUMMARY: Cryoglobulinemic vasculitis represents a crossroads among autoimmune and lymphoproliferative disorders; as hepatitis C virus infection is the major causative factor, cryoglobulinemic vasculitis is an important model for etiopathogenetic studies of virus-related disease
Biological Therapy and Risk of Malignancies: A Literature Review
No full textData from literature show that the overall risk of cancer does not as a result from treatment with these drugs. The only cancer for which various authors have reported an increased risk, in some cases, are skin cancers, different from melanoma and melanoma. Recent results of large observational studies and meta-analyzes indicate the absence of an increased risk of lymphoma related to therapy with anti-TNF-α. It has been reported, by some authors, that there is a possible increased risk of lung cancer, especially in patients with chronic obstructive pulmonary disease. There is limited information in literature about the effects of biologics in patients with a history of cancer. Most of the guidelines indicate that treatment with biologics can be considered with caution and only in patients free of cancer since at least 5 years. Some studies report a lower oncological risk with etanercept compared to monoclonal antibodies, especially in the case of lymphoma. However, this data has not been confirmed in other studies, and has been associated with a limited period of time after starting therapy. Information about the latest biological therapies is still poor. Therefore, there is not sufficient evidence for a preferential use of certain drugs rather than others
Chlamydia-induced arthritis. Immunofluorescent antibody studies of the synovial fluid from 4 patients Clin Exp Rheumatol. 1992 Jul-Aug;10(4):
No full textUsing two monoclonal antibodies in direct immunofluorescence we found material which could be identified as elementary bodies and cytoplasmic inclusions of Chlamydia trachomatis (Ct) in the synovial fluid of 4 patients affected by acute seronegative oligoarthritis. The finding of Ct in synovial fluids is a well known occurrence and has been demonstrated during the last few years in patients affected by seronegative oligoarthritis. However the fact was impossible to culture viable Ct from synovial fluid led researchers to believe that the local immune responses might be triggered by bacterial antigens in the non viable form.The findings described in this work suggest that in our cases the bacteria was present in metabolically active vegetative form
Effects of a paracetamol and tramadol fixed-dose combination on pain, asthenia, cognitive disorders and sleep quality in fibromyalgia
No full textFibromyalgia (FM) is a complex syndrome associated with a wide range of symptoms such as as-thenia, sleep disturbance and cognitive disorders, that frequently lead to wrong diagnoses and pointless tests or examinations. We focused our attention on a fixed combination of tramadol 37.5 mg + paracetamol 325 mg in a retrospective observational study on sixty-nine consecutive outpatients. An improvement in pain was observed in almost all patients , with a statistically significant reduction in VAS (8.1 vs. 5.5; p<0.001), Evoked Pain Score (2.7 vs. 2.0; p<0.001) and FM-related symptoms. The combined mechanism of action of paracetamol and tramadol are not merely analgesic: they may also provide a "ground-based" approach to FM and can be a valid analgesic treatment as they act on pain and on the associated symptom
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Hereditary hemochromatosis masquerading as rheumatoid arthritis
No full textEarly erroneous diagnosis of rheumatic disease is common in subjects with arthropathy due to hereditary hemochromatosis. A 71-year-old male with chronic obstructive pulmonary disease and monoclonal gammopathy underwent hip replacement and was referred to our Department because of altered liver function tests. Test results were negative for hepatitis B surface antigen and hepatitis C virus, and positive for rheumatoid factor. A diagnosis of rheumatoid arthritis had been made on the basis of compatible joint involvement and laboratory data and steroid treatment prescribed. Since his serum ferritin was 3249 ng/mL, genetic testing for hereditary hemochromatosis was carried out and revealed homozygosity for Cys282Tyr mutation in the HFE gene. Liver biopsy disclosed cirrhosis compatible with hemochromatosis. Following a review of the patients' radiographs, the diagnosis of hemochromatosis arthropathy was made. Phlebotomies and family screening for hereditary hemochromatosis were done. The most logical explanation for the positive rheumatoid factor result in this subject are his age and the presence of two chronic diseases involving long-standing antigenic stimulation and monoclonal gammopathy of uncertain significance. It is important to distinguish rheumatoid arthritis from hemochromatosis arthropathy for several reasons: patients with hereditary hemochromatosis do not require corticosteroid treatment; in case of erroneous diagnosis of rheumatoid arthritis, phlebotomy is not started early, and familial genetic counseling is not considered. In male subjects with positive rheumatoid factor and joint and liver disease, hereditary hemochromatosis should be considered. More liberal use of genetic testing is justified in such cases
Treatment of cryoglobulinemic neuropathy with alpha-interferon. Neurology. 1996 Feb;46(2):588-9
No full textWe read with interest the article by Khella et al on the treatment of cryoglobulinemic neuropathy with alpha-interferon (alpha-IFN). Our group has been studying the relationship between HCV and essential mixed cryoglobulinemia (EMC) since 1990. We are a collaborating center of the Italian Group for the Study of Cryoglobulinemias (GISC), and have recently published the results obtained from a large sample (654 patients with EMC). In this context, we have also studied the occurrence of cryoglobulinemia-related neuropathy. Our experience refers mainly to symmetrical and sensory motor neuropathies, although we have studied some cases of mononeuropathy multiplex. The observation that alpha-IFN was able to improve cryoglobulinemic vasculitis led us to investigate its effects on the peripheral nervous system, although some authors reported a worsening of peripheral neuropathy during therapy with alpha-IFN .Ten cryoglobulinemic patients with sensory motor polyneuropathy and HCV infection were treated with alpha-IFN at a dose of 3 mU, three times per week, for a period of 6 to 12 months. Seven patients treated for 6 to 12 months with deflazacort at a dose of 0.5 mg/kg/day were recruited as controls. All patients were submitted to a scoring test to establish the significance of neurologic symptoms (NSS scale) and an EMG study to evaluate: (1) the amplitude of peroneal motor action potential; (2) the sural sensory conduction velocity; (3) the ulnar F-wave latency, and (4) the ulnar and peroneal motor conduction velocities. A significant improvement of peripheral neuropathy was seen only in the group treated with alpha-IFN, as determined by the NSS scale. However, their EMG data at the end of therapy were not significantly different from those of the control patients. Nonetheless, it should be pointed out that in a patient with mononeuropathy multiplex, we did not see any improvement following 1 year of therapy with steroids and alpha-IFN However, in the same patient, treatment with cyclophosphamide was associated with a substantial regression of the symptoms with electroneurographic evidence of reinnervation (unpublished data).Therefore, we agree with Khella et al that cryoglobulinemic vasculitis in patients with HCV infection may benefit from treatment with alpha-IFN. However, a clinical and/or EMG improvement would not necessarily occur in all cases following this therapy. Further studies are needed to ascertain if higher dosages of alpha-IFN or other types of IFN, such as beta-IFN, are able to improve the electroneuromyographic findings
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