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1.
Proc Natl Acad Sci U S A ; 120(12): e2219668120, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36927156

RESUMO

Root anatomical phenotypes present a promising yet underexploited avenue to deliver major improvements in yield and climate resilience of crops by improving water and nutrient uptake. For instance, the formation of root cortical aerenchyma (RCA) significantly increases soil exploration and resource capture by reducing the metabolic costs of root tissue. A key bottleneck in studying such phenotypes has been the lack of robust high-throughput anatomical phenotyping platforms. We exploited a phenotyping approach based on laser ablation tomography, termed Anatomics, to quantify variation in RCA formation of 436 diverse maize lines in the field. Results revealed a significant and heritable variation for RCA formation. Genome-wide association studies identified a single-nucleotide polymorphism mapping to a root cortex-expressed gene-encoding transcription factor bHLH121. Functional studies identified that the bHLH121 Mu transposon mutant line and CRISPR/Cas9 loss-of-function mutant line showed reduced RCA formation, whereas an overexpression line exhibited significantly greater RCA formation when compared to the wild-type line. Characterization of these lines under suboptimal water and nitrogen availability in multiple soil environments revealed that bHLH121 is required for RCA formation developmentally as well as under studied abiotic stress. Overall functional validation of the bHLH121 gene's importance in RCA formation provides a functional marker to select varieties with improved soil exploration and thus yield under suboptimal conditions.


Assuntos
Fatores de Transcrição , Zea mays , Zea mays/metabolismo , Fatores de Transcrição/metabolismo , Estudo de Associação Genômica Ampla , Raízes de Plantas/metabolismo , Solo , Água/metabolismo
2.
Proc Natl Acad Sci U S A ; 116(41): 20776-20785, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31548423

RESUMO

sugary enhancer1 (se1) is a naturally occurring mutant allele involved in starch metabolism in maize endosperm. It is a recessive modifier of sugary1 (su1) and commercially important in modern sweet corn breeding, but its molecular identity and mode of action remain unknown. Here, we developed a pair of near-isogenic lines, W822Gse (su1-ref/su1-ref se1/se1) and W822GSe (su1-ref/su1-ref Se1/Se1), that Mendelize the se1 phenotype in an su1-ref background. W822Gse kernels have lower starch and higher water soluble polysaccharide and sugars than W822GSe kernels. Using high-resolution genetic mapping, we found that wild-type Se1 is a gene Zm00001d007657 on chromosome 2 and a deletion of this gene causes the se1 phenotype. Comparative metabolic profiling of seed tissue between these 2 isolines revealed the remarkable difference in carbohydrate metabolism, with sucrose and maltose highly accumulated in the mutant. Se1 is predominantly expressed in the endosperm, with low expression in leaf and root tissues. Differential expression analysis identified genes enriched in both starch biosynthesis and degradation processes, indicating a pleiotropic regulatory effect of se1 Repressed expression of Se1 and Su1 in RNA interference-mediated transgenic maize validates that deletion of the gene identified as Se1 is a true causal gene responsible for the se1 phenotype. The findings contribute to our understanding of starch metabolism in cereal crops.


Assuntos
Metabolismo dos Carboidratos , Endosperma/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Amido/metabolismo , Zea mays/metabolismo , Metaboloma , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Transcriptoma , Zea mays/genética , Zea mays/crescimento & desenvolvimento
4.
Plant Physiol ; 173(2): 1453-1462, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27999086

RESUMO

The plant hormone indole-3-acetic acid (IAA or auxin) mediates the elongation growth of shoot tissues by promoting cell expansion. According to the acid growth theory proposed in the 1970s, auxin activates plasma membrane H+-ATPases (PM H+-ATPases) to facilitate cell expansion by both loosening the cell wall through acidification and promoting solute uptake. Mechanistically, however, this process is poorly understood. Recent findings in Arabidopsis (Arabidopsis thaliana) have demonstrated that auxin-induced SMALL AUXIN UP RNA (SAUR) genes promote elongation growth and play a key role in PM H+-ATPase activation by inhibiting PP2C.D family protein phosphatases. Here, we extend these findings by demonstrating that SAUR proteins also inhibit tomato PP2C.D family phosphatases and that AtSAUR19 overexpression in tomato (Solanum lycopersicum) confers the same suite of phenotypes as previously reported for Arabidopsis. Furthermore, we employ a custom image-based method for measuring hypocotyl segment elongation with high resolution and a method for measuring cell wall mechanical properties, to add mechanistic details to the emerging description of auxin-mediated cell expansion. We find that constitutive expression of GFP-AtSAUR19 bypasses the normal requirement of auxin for elongation growth by increasing the mechanical extensibility of excised hypocotyl segments. In contrast, hypocotyl segments overexpressing a PP2C.D phosphatase are specifically impaired in auxin-mediated elongation. The time courses of auxin-induced SAUR expression and auxin-dependent elongation growth were closely correlated. These findings indicate that induction of SAUR expression is sufficient to elicit auxin-mediated expansion growth by activating PM H+-ATPases to facilitate apoplast acidification and mechanical wall loosening.


Assuntos
Proteínas de Arabidopsis/genética , Hipocótilo/crescimento & desenvolvimento , Ácidos Indolacéticos/metabolismo , Solanum lycopersicum/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hipocótilo/genética , Hipocótilo/metabolismo , Solanum lycopersicum/genética , Plantas Geneticamente Modificadas , Proteína Fosfatase 2C/genética , Proteína Fosfatase 2C/metabolismo , ATPases Translocadoras de Prótons/metabolismo
5.
Essays Biochem ; 58: 49-60, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26374886

RESUMO

Gibberellins (GAs) are phytohormones that regulate growth and development. DELLA proteins repress GA responses. GA binding to its receptor triggers a series of events that culminate in the destruction of DELLA proteins by the 26S proteasome, which removes the repression of GA signalling. DELLA proteins are transcription co-activators that induce the expression of genes which encode products that inhibit GA responses. In addition to repressing GA responses, DELLA proteins influence the activity of other signalling pathways and serve as a central hub from which other pathways influence GA signalling. In this role, DELLA proteins bind to and inhibit proteins, including transcription factors that act in the signalling pathways of other hormones and light. The binding of these proteins to DELLA proteins also inhibits DELLA activity. GA signalling is subject to homoeostatic regulation through GA-induced repression of GA biosynthesis gene expression, and increased production of the GA receptor and enzymes that catabolize bioactive GAs. This review also discusses the nature of mutant DELLA alleles that are used to produce high-yielding 'Green Revolution' cereal varieties, and highlights important gaps in our knowledge of GA signalling.


Assuntos
Giberelinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Homeostase , Proteínas de Plantas/fisiologia , Transativadores/fisiologia
6.
Plant Cell ; 27(6): 1579-94, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26036254

RESUMO

Gibberellin (GA) regulates plant development primarily by triggering the degradation/deactivation of the DELLA proteins. However, it remains unclear whether all GA responses are regulated by DELLAs. Tomato (Solanum lycopersicum) has a single DELLA gene named PROCERA (PRO), and its recessive pro allele exhibits constitutive GA activity but retains responsiveness to external GA. In the loss-of-function mutant pro(ΔGRAS), all examined GA developmental responses were considerably enhanced relative to pro and a defect in seed desiccation tolerance was uncovered. As pro, but not pro(ΔGRAS), elongation was promoted by GA treatment, pro may retain residual DELLA activity. In agreement with homeostatic feedback regulation of the GA biosynthetic pathway, we found that GA20oxidase1 expression was suppressed in pro(ΔGRAS) and was not affected by exogenous GA3. In contrast, expression of GA2oxidase4 was not affected by the elevated GA signaling in pro(ΔGRAS) but was strongly induced by exogenous GA3. Since a similar response was found in Arabidopsis thaliana plants with impaired activity of all five DELLA genes, we suggest that homeostatic GA responses are regulated by both DELLA-dependent and -independent pathways. Transcriptome analysis of GA-treated pro(ΔGRAS) leaves suggests that 5% of all GA-regulated genes in tomato are DELLA independent.


Assuntos
Giberelinas/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Solanum lycopersicum/fisiologia , Ácido Abscísico/fisiologia , Retroalimentação Fisiológica , Genes de Plantas/fisiologia , Solanum lycopersicum/genética , Mutação , Reguladores de Crescimento de Plantas/genética , Proteínas de Plantas/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Transcriptoma
7.
Osteoporos Int ; 26(5): 1629-38, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25619634

RESUMO

UNLABELLED: Osteoporosis treatment has low adherence and persistence. This study evaluated if greater patient involvement could improve them. At 12 months, only 114 out of 344 participants were "fully adherent and persistent" (all drug doses taken throughout the study). Only frequency of drug administration had a significant influence on adherence. INTRODUCTION: Osteoporosis affects millions of individuals worldwide. There are now several effective drugs, but adherence to and persistence with treatment are low. This 12-month multicenter, prospective, randomized study evaluated the efficacy of two different methods aimed at improving adherence and persistence through greater patient involvement, compared with standard clinical practice. METHODS: Three hundred thirty-four post-menopausal women, receiving an oral prescription for osteoporosis for the first time, were recruited and randomized into three groups: group 1 (controls, managed according to standard clinical practice) and groups 2 and 3 (managed with greater patient and caregiver involvement and special reinforcements: group 2, instructed to use several different "reminders"; group 3, same "reminders" as group 2, plus regular phone calls from and meetings at the referring Center). All enrolled women had two visits (baseline and 12 months). RESULTS: Of 334 enrolled women, 247 (74%) started the prescribed therapy. Of those who started, 219 (88.7%) persisted in therapy for at least 10 months. At final evaluation, only 114 women were considered as "fully adherent and persistent" (all doses taken throughout the 12 months). There were no significant differences regarding "full adherence" among the three randomized groups. The frequency of drug administration had a significant influence: weekly administration had a >5-fold higher adherence and monthly administration an 8-fold higher adherence (p < 0.0001) than daily administration. CONCLUSIONS: The special effort of devising and providing additional reminders did not prove effective. Additional interventions during the follow-up, including costly interventions such as phone calls and educational meetings, did not provide significant advantages.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Adesão à Medicação/psicologia , Osteoporose Pós-Menopausa/tratamento farmacológico , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Conservadores da Densidade Óssea/uso terapêutico , Esquema de Medicação , Feminino , Humanos , Itália , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/psicologia , Educação de Pacientes como Assunto/métodos , Participação do Paciente , Estudos Prospectivos , Telefone
9.
Osteoporos Int ; 22(2): 529-39, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20458570

RESUMO

UNLABELLED: Boys with Duchenne muscular dystrophy often have reduced bone mass and increased fracture risk. In this prospective study on 33 patients, calcifediol (25-OH vitamin D(3)) plus adjustment of dietary calcium to the recommended dose reduced bone resorption, corrected vitamin D deficiency, and increased bone mass in about two-thirds of cases. INTRODUCTION: Low BMC and BMD and bone metabolism alterations are frequent in boys with Duchenne muscular dystrophy (DMD), especially now that long-term glucocorticosteroid (GC) treatment is the standard of care. This prospective study was designed to evaluate the effects of a first-line treatment (25-OH vitamin D(3) [calcifediol] plus adjustment of dietary calcium to the recommended daily dose) on bone. METHODS: Thirty-three children with DMD on GC treatment were followed for 3 years: one of observation and two of treatment. MAIN OUTCOME: spine and total body BMC and BMD increase; secondary outcome: changes in bone turnover markers (C-terminal [CTx] and N-terminal [NTx] telopeptides of procollagen type I; osteocalcin [OC]). RESULTS: During the observation year, BMC and BMD decreased in all patients. At baseline and after 12 months, serum CTx and urinary NTx were higher than normal; OC and parathyroid hormone at the upper limit of normal; 25-OH vitamin D(3) significantly lower than normal. After 2 years of calcifediol and calcium-rich diet, BMC and BMD significantly increased in over 65% of patients, and bone metabolism parameters and turnover markers normalized in most patients (78.8%). During the observation year, there were four fractures in four patients, while during the 2 years of treatment there were two fractures in two patients. CONCLUSIONS: Calcifediol plus adequate dietary calcium intake seems to be an effective first-line approach that controls bone turnover, corrects vitamin D deficiency, and increases BMC and BMD in most patients with DMD. Lack of response seems related to persistently high bone turnover.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Densidade Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Calcifediol/farmacologia , Cálcio da Dieta/farmacologia , Distrofia Muscular de Duchenne/complicações , Adolescente , Conservadores da Densidade Óssea/administração & dosagem , Reabsorção Óssea/tratamento farmacológico , Calcifediol/administração & dosagem , Cálcio da Dieta/administração & dosagem , Criança , Pré-Escolar , Colágeno Tipo I/metabolismo , Glucocorticoides/efeitos adversos , Humanos , Masculino , Distrofia Muscular de Duchenne/tratamento farmacológico , Osteocalcina/sangue , Hormônio Paratireóideo/sangue , Peptídeos/metabolismo , Estudos Prospectivos , Resultado do Tratamento , Vitamina D/análogos & derivados , Vitamina D/sangue , Deficiência de Vitamina D/tratamento farmacológico
11.
Int J Obes Relat Metab Disord ; 24(6): 735-41, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10878680

RESUMO

BACKGROUND: Circulating lymphocytes of obese individuals with and without type 2 diabetes have derangements of pyruvate dehydrogenase (PDH) that are described as reflecting a disorder underlying systemic insulin resistance, namely basal activity below normal and, in vitro, unresponsiveness to insulin at 33 pmol/l and activation at 330 pmol/l instead of activation and inhibition as in controls. OBJECTIVE: To explore whether the above enzyme derangements are overcome in obese individuals on dexfenfluramine treatment, known to improve poor peripheral insulin sensitivity. METHODS: Fifteen obese diabetic patients and 15 age-matched euglycaemic obese subjects with normal glucose tolerance were enrolled for a trial composed of two 21-day periods; in the first (D-21-D0), participants received a placebo, and in the second (D0-D21), dexfenfluramine (30 mg/day). At D-21, D0 and D21 participants were evaluated for weight, BMI, fasting glycaemia (FG), fasting insulinaemia (FI), fasting insulin resistance index (FIRI), area under the glycaemic (G-AUC) and insulinaemic (I-AUC) curves from an OGT test, and for PDH activity assayed in their circulating lymphocytes before (basal activity) and after incubation with 33 or 330 pmol/l insulin. At D2, basal PDH activity and clinical parameters were assayed. RESULTS: In both groups of participants at D0 all parameters tested were constant with respect to D-21; at D2, only basal PDH activity rose significantly; at D21, basal and insulin stimulated PDH activities were normalized and weight decreased significantly, as did FG, FI, FIRI and G-AUC in the diabetic, and FI, FIRI, G-AUC and I-AUC in the non-diabetic participants. CONCLUSION: In obese, non-diabetic and diabetic individuals on dexfenfluramine treatment, amelioration of clinical parameters and indexes of poor insulin sensitivity of blood glucose homeostasis are preceded by correction, in their circulating lymphocytes, of PDH derangements described as reflecting a disorder underlying insulin resistance.


Assuntos
Dexfenfluramina/uso terapêutico , Resistência à Insulina , Obesidade/tratamento farmacológico , Complexo Piruvato Desidrogenase/sangue , Adulto , Glicemia/metabolismo , Índice de Massa Corporal , Diabetes Mellitus/sangue , Diabetes Mellitus/tratamento farmacológico , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Insulina/sangue , Insulina/farmacologia , Linfócitos/enzimologia , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Placebos , Redução de Peso
12.
Haematologica ; 84(10): 879-86, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10509034

RESUMO

BACKGROUND AND OBJECTIVE: Stem cell factor (SCF), and its receptor (c-kit) play key roles in the expansion and differentiation of hematopoietic progenitor cells, in melanoblasts and primordial germ cells, making it possible that SCF and c-kit are involved in neoplastic processes deriving from these cells. C-kit has been described to be expressed at different levels in neuroblastoma and in soft tissue sarcoma of neuroectodermal origin, and seems to be required for survival processes. In this study we investigate how c-kit expression is regulated and whether a SCF autocrine loop is essential for survival of sarcoma cell lines. DESIGN AND METHODS: C-kit modulation and internalization was evaluated incubating cells with rhSCF. Cell differentiation and proliferation experiments were performed to test whether c-kit expression is related to cell cycle progression or to differentiation processes. Cell cultures were treated with neutralizing antibody and antisense oligonucleotides in order to assess the possible significance of the SCF autocrine loop. RESULTS: In vitro SCF stimulation induces c-kit down-regulation; this phenomenon could be connected with receptor internalization, and new protein synthesis is necessary for its re-expression. The cell proliferation arrest in G0/G1 does not modify c-kit expression while down-regulation of c-kit was demonstrated after cells had been treated with differentiating agents. SCF neutralization does not influence either the S phase or apoptosis in sarcoma cell lines. INTERPRETATION AND CONCLUSIONS: In sarcoma cell lines, c-kit is regulated by differentiation processes; moreover our results suggest that c-kit activity, but probably not the SCF autocrine loop, is essential for survival of these cell lines.


Assuntos
Divisão Celular/efeitos dos fármacos , Tumores Neuroectodérmicos/metabolismo , Proteínas Proto-Oncogênicas c-kit/efeitos dos fármacos , Sarcoma/metabolismo , Fator de Células-Tronco/farmacologia , Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/imunologia , Comunicação Autócrina , Bucladesina/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cicloeximida/farmacologia , Expressão Gênica/efeitos dos fármacos , Humanos , Tumores Neuroectodérmicos/patologia , Oligonucleotídeos Antissenso/farmacologia , Proteínas Proto-Oncogênicas c-kit/análise , Proteínas Proto-Oncogênicas c-kit/genética , RNA Mensageiro , Fase S/efeitos dos fármacos , Fase S/imunologia , Sarcoma/patologia , Fator de Células-Tronco/genética , Fator de Células-Tronco/imunologia , Células Tumorais Cultivadas
13.
J Endocrinol Invest ; 22(7): 519-26, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10475149

RESUMO

Pyruvate dehydrogenase (PDH) is poorly active in circulating lymphocytes of NIDDM patients; in vitro, it is unresponsive to insulin at 5 microU/ml and activated at 50 microU/ml, instead of activated and inhibited as in healthy controls. This study examines whether healthy offspring of NIDDM patients with a family history for this disease have these alterations. Twenty seven healthy offspring (23+/-10 yr, median 18 yr) and their parents (13 diabetic with a family history for NIDDM and 11 healthy without this history) were enrolled. Twenty healthy individuals without the history and matched for age and gender with the offspring served as controls. Minimum levels for enzyme activity before and after cell stimulation with insulin at 5 microU/ml were computed for a 95% CI with no more than 5% of the controls excluded. Increased or unvaried enzyme activity in response to insulin at 50 microU/ml was defined as abnormal. All NIDDM parents and 11/27 offspring had below normal enzyme activity and defective and reversed enzyme response to insulin at 5 and 50 microU/ml; three offspring had altered enzyme response to insulin at both concentrations, four to insulin at 5 microU/ml, three to insulin at 50 microU/ml and six, together with the healthy parents, had no alterations. We conclude that in healthy individuals a family history for NIDDM is frequently signaled, irrespective of age, by molecular derangements, with an apparent genetic background, in their circulating lymphocytes.


Assuntos
Diabetes Mellitus Tipo 2/enzimologia , Linfócitos/enzimologia , Complexo Piruvato Desidrogenase/sangue , Adolescente , Adulto , Feminino , Humanos , Insulina/farmacologia , Masculino , Pessoa de Meia-Idade
14.
Support Care Cancer ; 7(4): 253-9, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10423051

RESUMO

The purpose of the present study was to analyze the characteristics of infectious complications occurring during the first 100 days after bone marrow transplantation (BMT) in a cohort of 123 pediatric patients with hematological malignancies (n = 73), solid tumors (n = 32) and nonmalignant disorders (n = 18). Fifty-eight patients received allogeneic grafts, and 65 patients an autologous transplant. Fever developed in 107 (87%) children; 82% of infectious complications occurred during the neutropenic period. Documented infection developed in 33 (31%) patients, while 74 (69%) patients had possible infection (i.e. fever of unknown origin). The incidence of bacteremia was 21%, and gram-positive cocci were the predominant pathogens; non-bacteremic microbiologically documented infection developed in 6% of patients; clinically evident infection developed in 4% of subjects. The incidence of primary febrile episodes was not significantly different between autologous and allogeneic BMT (86% vs 88%); nor did the median number of days to the onset of fever (5 days in both groups) or the median duration of fever (5 days in both groups) differ. In contrast, the frequency of secondary febrile episodes was significantly higher (P = 0.0001) in allogeneic BMT recipients (40%) than in autologous recipients (15%). The mortality rate due to infections was 2/36 (5%) for matched sibling donor BMT, and 1/13 (8%) for matched unrelated donor BMT. No deaths occurred in the 65 patients who were autografted. Invasive fungal infections accounted for 2 of the 3 infectious deaths. In conclusion, the majority of children undergoing BMT experienced at least one infectious episode; allogeneic BMT recipients were at high risk of developing secondary febrile episodes, but the overall mortality rate due to infection in the first 100 days after transplantation was low.


Assuntos
Bacteriemia/epidemiologia , Bacteriemia/etiologia , Transplante de Medula Óssea/efeitos adversos , Adolescente , Adulto , Bacteriemia/diagnóstico , Transplante de Medula Óssea/mortalidade , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Estudos de Coortes , Intervalos de Confiança , Feminino , Seguimentos , Sobrevivência de Enxerto , Doenças Hematológicas/diagnóstico , Doenças Hematológicas/terapia , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/terapia , Humanos , Incidência , Itália/epidemiologia , Masculino , Neoplasias/diagnóstico , Neoplasias/terapia , Fatores de Risco , Taxa de Sobrevida , Fatores de Tempo , Transplante Autólogo , Transplante Homólogo
15.
J Clin Endocrinol Metab ; 83(8): 2886-91, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9709964

RESUMO

Epidemiological studies support the hypothesis that genetic factors modulate the risk for diabetic nephropathy (DN). Aldose reductase (ALDR1), the rate-limiting enzyme in the polyol pathway, is a potential candidate gene. The present study explores the hypothesis that polymorphisms of the (A-C)n dinucleotide repeat sequence, located 2.1 kb upstream of the transcription start site, modulate ALDR1 gene expression and the risk for DN. We conducted studies at two different institutions, the University of New Mexico Health Sciences Center (UNMHSC), and the Istituto Scientifico H San Raffaele (HSR). There were four groups of volunteers at UNMHSC: group I, normal subjects; group II, patients with insulin-dependent diabetes mellitus (IDDM) without DN; group III, IDDM with DN; and group IV, nondiabetics with kidney disease. At HSR we studied volunteers in groups I, II, and III. ALDR1 genotype was assessed by PCR and fluorescent sequencing of the (A-C)n repeat locus, and ALDR1 messenger ribonucleic acid (mRNA) was measured by ribonuclease protection assay in peripheral blood mononuclear cells. At UNMHSC we identified 10 alleles ranging from Z-10 to Z+8. The prevalence of the Z-2 allele among IDDM patients was increased in those with DN. Sixty percent of group III and 22% of group II were homozygous for Z-2. Moreover, 90% and 67% of groups III and II, respectively, had 1 or more copy of Z-2. In contrast, among nondiabetics, 19% of group IV and 3% of group I were homozygous for Z-2, and 69% and 32%, respectively, had 1 copy or more of Z-2. Among diabetics, homozygosity for the Z-2 allele was associated with renal disease [odds ratio (OR), 5.25; 95% confidence interval, 1.71-17.98; P = 0.005]. ALDR1 mRNA levels were higher in patients with DN (group III; 0.113 +/- 0.050) than in group I (0.068 +/- 0.025), group II (0.042 +/- 0.020), or group IV (0.015 +/- 0.011; P < 0.01). Among diabetics, ALDR1 mRNA levels were higher in Z-2 homozygotes (0.098 +/- 0.06) and Z-2 heterozygotes (0.080 +/- 0.04) than in patients with no Z-2 allele (0.043 +/- 0.02; P < 0.05). In contrast, among nondiabetics, ALDR1 mRNA levels in Z-2 homozygotes (0.034 +/- 0.04) and Z-2 heterozygotes (0.038 +/- 0.03) were similar to levels in patients without a Z-2 allele (0.047 +/- 0.03; P = NS). At HSR we identified eight alleles ranging from Z- 12 to Z+2. The prevalence of the Z-2 allele was higher in group III than in group II. In group III, 43% of the patients were homozygous for Z-2, and 81% had one copy or more of the Z-2 allele. In contrast, in group II, 4% were homozygous for Z-2, and 36% had one copy or more of the Z-2 allele. IDDM patients homozygous for Z-2 had an increased risk for DN compared with those lacking the Z-2 allele (OR, 18; 95% confidence interval, 2-159). IDDM patients who had one copy or more of Z-2 had increased risk (OR, 7.5; 95% confidence interval, 1.9-29.4) for DN compared with those without the Z-2 allele. These results support our hypothesis that environmental-genetic interactions modulate the risk for DN. Specifically, the Z 2 allele, in the presence of diabetes and/or hyperglycemia, is associated with increased ALDR1 expression. This interaction may explain the observed association between the Z-2 allele and DN.


Assuntos
Aldeído Redutase/genética , Alelos , Diabetes Mellitus Tipo 1/enzimologia , Nefropatias Diabéticas/enzimologia , Expressão Gênica , Repetições de Microssatélites , Adulto , Diabetes Mellitus Tipo 1/genética , Nefropatias Diabéticas/genética , Feminino , Genótipo , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
16.
Blood ; 91(7): 2397-405, 1998 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9516139

RESUMO

During development, mice with mutations of stem cell factor (SCF) or its receptor c-kit exhibit defects in melanogenesis, as well as hematopoiesis and gonadogenesis. Consequently, accumulating evidence suggests that the c-kit/SCF system plays a crucial role in all of these processes and in tumors which derive from them. Especially in neuroblastoma (infant tumors of neuroectoderm crest derivation such as melanocytes) it would appear that an autocrine loop exists between c-kit and SCF, and that the functional block of the c-kit receptors with monoclonal antibodies (MoAbs) results in a significant decrease in cellular proliferation. We studied the expression and role of c-kit and SCF in cell lines of soft tissue sarcoma of neuroectodermic origin, such as Ewing's sarcoma (ES) and peripheral neuro-ectodermal tumors (PNET). Using flow cytometry with MoAb CD117 PE, c-kit expression was highlighted in all six of the cell lines examined. This receptor was specifically and functionally activated by SCF, as shown by the binding experiments and the intracellular phosphotyrosine and immunoprecipitation studies that were performed. Using reverse transcriptase polymerase chain reaction analysis, five of the six cellular lines expressed the mRNA of SCF. In the medium measured by using an enzyme- linked immunosorbent assay, low concentrations of SCF were found: only the TC32 cellular line produced significantly higher levels (32 pg) than control. In serum-free culture the addition of SCF reduced the percentage of apoptotic cells from 25% to 90% in five out of the six cellular lines. This observation was confirmed by (1) the functional block of c-kit with MoAb: after 7 days of culture more than 30% of the cells were apoptotic (range 31.5% to 100%) in five out of six cell lines and there was also a decrease in the percentage of cells in phase S, and (2) c-kit antisense oligonucleotides: in the cellular lines treated with oligonucleotides (in relation to the untreated lines) there was a notable reduction (P < .001) both in the absolute number of cells and the 3H-thymidine uptake. These results indicate that ES and PNET express c-kit and its ligand SCF and that SCF is capable of protecting the tumor cells against apoptosis. Furthermore, the reverse transcriptase-polymerase chain reaction performed on the biopsies revealed the presence of mRNA both of SCF and c-kit in practically all of the samples studied. Our in vitro data lead us to assume that SCF may also inhibit tumor cell apoptosis in vivo.


Assuntos
Apoptose , Neoplasias Ósseas/patologia , Tumores Neuroectodérmicos Primitivos Periféricos/patologia , Proteínas Proto-Oncogênicas c-kit/metabolismo , Sarcoma de Ewing/patologia , Sarcoma/patologia , Fator de Células-Tronco/metabolismo , Animais , Neoplasias Ósseas/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Tumores Neuroectodérmicos Primitivos Periféricos/metabolismo , Oligonucleotídeos Antissenso , Proteínas Proto-Oncogênicas c-kit/genética , Sarcoma/metabolismo , Sarcoma de Ewing/metabolismo , Fator de Células-Tronco/genética , Células Tumorais Cultivadas
17.
Pediatr Hematol Oncol ; 14(5): 469-74, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9267880

RESUMO

In patients undergoing bone marrow transplantation cryptococcosis is rarely encountered. We report a fatal case of Cryptococcus meningitis in a 12-year-old girl with acute lymphoblastic leukemia (ALL) in second remission who had a transplant from a human leukocyte antigen (HLA)-identical unrelated bone marrow donor. The conditioning regimen was thiotepa, cyclophosphamide, and total body irradiation (TBI); graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A, methotrexate, and antilymphocyte globulin (ALG). The patient experienced stage III GVHD responsive to high-dose corticosteroids. On day +54 a thrombotic microangiopathy occurred. On day +64 neurological status worsened; a brain computed tomographic (CT) scan showed hyperdense lesions suggesting fungal infection. Detection of cryptococcal antigen by latex agglutination was positive but India ink stain and culture were negative. Despite treatment with amphotericin B, 5-flucytosine, and granulocyte-macrophage colony-stimulating factor, the patient died 13 days after the diagnosis.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Meningite Criptocócica/etiologia , Trombose/etiologia , Trombose/fisiopatologia , Criança , Evolução Fatal , Feminino , Teste de Histocompatibilidade , Humanos , Meningite Criptocócica/fisiopatologia , Microcirculação/patologia , Doadores de Tecidos , Transplante Homólogo
18.
Minerva Anestesiol ; 63(7-8): 221-8, 1997.
Artigo em Italiano | MEDLINE | ID: mdl-9489307

RESUMO

BACKGROUND: Orthotopic liver transplantation (OLI) is a recognised means of therapy for endstage liver failure (ESLF). Both the preoperative alterations of renal function, closely correlated with the ESLF, and the frequent and abrupt changes of circulating blood volumes occurring during the various phases of OLT are able to significantly alter renal function during the perioperative period. METHODS: In order to define the specific changes of renal function during the various phases of OLT, six postnecrotic cirrhotic patients undergoing their first OLT entered a prospective study protocol. All the patients had standard and anesthetic techniques including the venovenous bypass (VVBP) during the anhepatic phase. At standard intervals (baseline, during hepatic dissection, during the anhepatic phase, following reperfusion, at the end of surgery) together with complete hemodynamic and metabolic profiles, arterial blood and urine samples were obtained to determine electrolytes and creatinine concentrations, blood levels of atrial natriuretic factor, aldosterone and renin activity. Using standard formulas creatinine clearance (Ccreat) and Na absolute and fractional excretions (FeNa%) were calculated. RESULTS: Major changes in the hemodynamic profile occurred during the anhepatic phase in spite of the use of the VVBP (reduced cardiac index, reduced pulmonary wedge pressure, increased systemic vascular resistances). Concomitantly a significant decrease in Ccreat (-67%) and in urinary output, was present while aldosterone and renin activity increased. The changes in Ccreat persisted at the end of surgery in spite of the optimal hemodynamic profile. Aldosterone and renin activity returned to values close to baseline at the end of surgery. CONCLUSIONS: From these data it is possible to conclude that renal function markedly deteriorates during OLT and it has to be considered at increased risk in the immediate postoperative period. The use of VVBP does not seem to prevent the intraoperative renal impairment.


Assuntos
Testes de Função Renal , Transplante de Fígado/fisiologia , Adulto , Feminino , Humanos , Cirrose Hepática/cirurgia , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória , Circulação Renal/fisiologia
19.
Artif Organs ; 21(5): 405-8, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9129773

RESUMO

Catheter complications are a common problem during long-term insulin therapy with implanted pumps. The purpose of this study was to test the feasibility of imaging intraperitoneal catheters with technetium (Tc) 99m in implantable devices for insulin delivery. Testing physical stability of an insulin/Tc 99 mixture did not show formation of insulin aggregates during a period up to 48 h on a rotating wheel. Five hundred microCurie (equal to 18 MBq) of Tc 99m were injected in the flush port of a pump for intraperitoneal insulin delivery implanted in patients with type I (insulin dependent) diabetes mellitus, and gamma camera images were obtained for 30 min. In patent catheters the tracer rapidly imaged the whole length of the catheter while in occluded catheters the tracer remained in the flush port, imaging only the portion of the catheter before the occlusion. In patent catheters in which insulin absorption was impaired, the tracer rapidly imaged the whole length of the catheter, but its removal from the peritoneum was delayed. Tc 99m imaging of intraperitoneal catheters for insulin delivery can be used to assess catheter patency and impaired delivery into the peritoneal cavity.


Assuntos
Cateterismo/normas , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Bombas de Infusão Implantáveis/normas , Insulina/administração & dosagem , Sistemas de Liberação de Medicamentos , Estudos de Viabilidade , Feminino , Raios gama , Humanos , Hipoglicemiantes/metabolismo , Hipoglicemiantes/uso terapêutico , Infusões Parenterais , Insulina/metabolismo , Insulina/uso terapêutico , Marcação por Isótopo , Masculino , Tecnécio
20.
Panminerva Med ; 38(4): 234-42, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9063032

RESUMO

Marigen is a Swiss Research Company based in Riehen (Canton of Basle). It has developed and tested a Solubilization System for its phytosteryl ester compounds having antitumor and antiviral/virucidal activity. By formulating spontaneously dispersible concentrates, which comprise such compounds, it is now possible to produce thermodynamically stable, aqueous ultramicroemulsions which achieve outstanding bioavailability and bio-reactivity for the active principles comprised in these Marigenol-Concen-trates. As a consequence, unwanted side-effects are drastically reduced in therapeutical use or even completely absent, and the economy of the system permits a remarkable optimization of the dose-efficacy relationship and hence also of drug safety.


Assuntos
Alcaloides/administração & dosagem , Alcaloides/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antivirais/administração & dosagem , Antivirais/química , Paclitaxel/administração & dosagem , Paclitaxel/química , Veículos Farmacêuticos/administração & dosagem , Veículos Farmacêuticos/química , Taxoides , Química Farmacêutica , Emulsões , Humanos , Fitosteróis/química , Solubilidade
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