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1.
Eur J Nucl Med Mol Imaging ; 49(2): 721-731, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34342669

RESUMEN

PURPOSE: 68 Ga-FAPI (fibroblast activation protein inhibitor) is a rapidly evolving and highly promising radiotracer for PET/CT imaging, presenting excellent results in a variety of tumor entities, particularly in epithelial carcinomas. This retrospective analysis sought to evaluate the potential and impact of FAPI-PET/CT in rare cancer diseases with respect to improvement in staging and therapy, based on tracer uptake in normal organs and tumors. MATERIAL AND METHODS: Fifty-five patients with rare tumor entities, defined by a prevalence of 1 person out of 2000 or less, received a 68 Ga-FAPI-PET/CT scan. Fourteen women and 41 men (median age 60) were included within the following subgroups: cancer of unknown primary (n = 10), head and neck cancer (n = 13), gastrointestinal and biliary-pancreatic cancer (n = 17), urinary tract cancer (n = 4), neuroendocrine cancer (n = 4), and others (n = 7). Tracer uptake was quantified by standardized uptake values SUVmax and SUVmean and the tumor-to-background ratio (TBR) was determined (SUVmax tumor/SUVmean organ). RESULTS: In 20 out of 55 patients, the primary tumor was identified and 31 patients presented metastases (n = 88), characterized by a high mean SUVmax in primary (10.1) and metastatic lesions (7.6). The highest uptake was observed in liver metastases (n = 6) with a mean SUVmax of 9.8 and a high TBR of 8.7, closely followed by peritoneal carcinomatosis (n = 16) presenting a mean SUVmax of 9.8 and an excellent TBR of 29.6. In terms of the included subgroups, the highest uptake regarding mean SUVmax was determined in gastrointestinal and biliary-pancreatic cancer with 9.8 followed closely by urinary tract cancer with 9.5 and head and neck cancer (9.1). CONCLUSION: Due to excellent tumor visualization and, thereby, sharp contrasts in terms of high TBRs in primary and metastatic lesions in different rare malignancies, 68 Ga-FAPI-PET/CT crystallizes as a powerful and valuable imaging tool, particularly with respect to epithelial carcinomas, and therefore an enhancement to standard diagnostics imaging methodologies. The realization of further and prospective studies is of large importance to confirm the potential of FAP imaging in oncology.


Asunto(s)
Neoplasias Pancreáticas , Tomografía Computarizada por Tomografía de Emisión de Positrones , Transporte Biológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Estudios Prospectivos , Estudios Retrospectivos
2.
Eur J Nucl Med Mol Imaging ; 44(4): 678-688, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27889802

RESUMEN

PURPOSE: The prostate-specific membrane antigen (PSMA) targeted positron-emitting-tomography (PET) tracer 68Ga-PSMA-11 shows great promise in the detection of prostate cancer. However, 68Ga has several shortcomings as a radiolabel including short half-life and non-ideal energies, and this has motivated consideration of 18F-labelled analogs. 18F-PSMA-1007 was selected among several 18F-PSMA-ligand candidate compounds because it demonstrated high labelling yields, outstanding tumor uptake and fast, non-urinary background clearance. Here, we describe the properties of 18F-PSMA-1007 in human volunteers and patients. METHODS: Radiation dosimetry of 18F-PSMA-1007 was determined in three healthy volunteers who underwent whole-body PET-scans and concomitant blood and urine sampling. Following this, ten patients with high-risk prostate cancer underwent 18F-PSMA-1007 PET/CT (1 h and 3 h p.i.) and normal organ biodistribution and tumor uptakes were examined. Eight patients underwent prostatectomy with extended pelvic lymphadenectomy. Uptake in intra-prostatic lesions and lymph node metastases were correlated with final histopathology, including PSMA immunostaining. RESULTS: With an effective dose of approximately 4.4-5.5 mSv per 200-250 MBq examination, 18F-PSMA-1007 behaves similar to other PSMA-PET agents as well as to other 18F-labelled PET-tracers. In comparison to other PSMA-targeting PET-tracers, 18F-PSMA-1007 has reduced urinary clearance enabling excellent assessment of the prostate. Similar to 18F-DCFPyL and with slightly slower clearance kinetics than PSMA-11, favorable tumor-to-background ratios are observed 2-3 h after injection. In eight patients, diagnostic findings were successfully validated by histopathology. 18F-PSMA-1007 PET/CT detected 18 of 19 lymph node metastases in the pelvis, including nodes as small as 1 mm in diameter. CONCLUSION: 18F-PSMA-1007 performs at least comparably to 68Ga-PSMA-11, but its longer half-life combined with its superior energy characteristics and non-urinary excretion overcomes some practical limitations of 68Ga-labelled PSMA-targeted tracers.


Asunto(s)
Antígenos de Superficie/metabolismo , Glutamato Carboxipeptidasa II/metabolismo , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata/diagnóstico por imagen , Dosis de Radiación , Radiofármacos/farmacocinética , Anciano , Radioisótopos de Flúor , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias de la Próstata/patología , Radiofármacos/administración & dosificación , Radiofármacos/efectos adversos , Eliminación Renal , Distribución Tisular
3.
Mol Imaging Biol ; 25(3): 554-559, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36369484

RESUMEN

AIM/PURPOSE: 18F-labeled PSMA ligands offer various advantages as PET tracers over 68Ga-labeled PSMA counterparts. Especially, an improved spatial resolution leads to improved detection rates of smaller prostate cancer (PCa) lesions. However, physiological PSMA uptake of ganglia of the sympathetic trunk can be quickly misinterpreted as possible PSMA-positive lymph node metastases. The aim of this retrospective study is to investigate [18F]PSMA-1007 uptake and its intra-individual reproducibility in ganglia of the sympathetic trunk. METHODS: We retrospectively included 28 consecutive patients (median age 69 ± 9 with a range of 49-90) with biochemical recurrence of PCa who underwent [18F]PSMA-1007 PET/CT scan and, accordingly, a follow-up examination between August 2018 and August 2021. Cervical, coeliac, and sacral ganglia were identified on the iterative PET reconstructions and correlated with CT component. Tracer uptake of ganglia was determined by measuring SUVmax and SUVmean values. Anatomical position of the ganglia in relation to adjacent vertebral bodies were noted. Statistical analyses were conducted using two-way repeated measures ANOVA and descriptive statistics. RESULTS: The highest [18F]PSMA-1007 uptake was found in coeliac ganglia followed by cervical and sacral ganglia. The SUVmax in coeliac ganglia was 3.13 ± 0.85 (follow-up scan 3.11 ± 0.93), in cervical ganglia 2.73 ± 0.69 (follow-up scan 2.67 ± 0.74), and in sacral ganglia 1.67 ± 0.50 (follow-up scan 1.64 ± 0.52). The SUVmean in coeliac ganglia was 2.28 ± 0.64 (follow-up scan 2.28 ± 0.66), in cervical ganglia 1.62 ± 0.43 (follow-up scan 1.61 ± 0.43) and in sacral ganglia 1.15 ± 0.33 (follow-up scan 1.12 ± 0.34). In a given ganglion station, there was no statistically significant difference of SUVmax or SUVmean values between baseline and follow-up scans. CONCLUSIONS: The first systematically described physiological [18F]PSMA-1007 uptake in ganglia of the sympathetic trunk showed a low variability of SUVmax or SUVmean and a good intra-individual reproducibility of [18F]PSMA-1007 uptake in follow-up scans. These findings might improve and guide the differentiation of ganglia from possible malignant lesions.


Asunto(s)
Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Masculino , Humanos , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Reproducibilidad de los Resultados , Radioisótopos de Galio , Neoplasias de la Próstata/patología , Ganglios/patología , Ácido Edético
4.
Plant Dis ; 96(3): 460, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30727100

RESUMEN

Avocado (Persea americana Mill.) is grown in some areas of southern Italy. In spring 2011, a previously unknown rot was observed on fruit that was marketed in Torino (northern Italy). The decayed area started from the stalk, appeared irregular and soft, and was surrounded by a dark brown margin. The internal decayed area appeared rotten, brown, and surrounded by bleached tissue. Fragments (approximately 3 mm) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at temperatures between 21 and 25°C under alternating conditions of light and dark. Colonies of the fungus initially appeared whitish, later turning mouse gray to black. Mature mycelium was septate and produced a dark pigment. The fungus, grown on oat agar (2) and incubated at temperatures between 21 and 25°C under alternating light and darkness, produced grayish colonies with a fluffy aerial mycelium that became dark with age and produced black pigments. After 18 days of incubation, such colonies produced pycnidia aggregated into stromatic masses, emerging from decayed tissues, and up to 3 to 4 mm in diameter. Conidia produced in the pycnidia were initially unicellular, hyaline, granulose, ovoid to ellipsoidal, and measured 20.8 to 26.9 × 12.5 to 16.1 (average 24.4 × 13.5) µm. After 7 days, mature conidia became darker, uniseptate, and longitudinally striate. Paraphyses produced within the tissues of pycnidia were hyaline, cylindrical, nonseptate, and up to 63 µm long. Morphological characteristics of mycelia, pycnidia, and conidia observed with a light microscope permitted identify of the fungus as Lasiodiplodia theobromae (3). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis (1) of the 488-bp segment showed a 100% similarity with the corresponding sequence (GenBank Accession No. GQ502453) of L. theobromae Pat. Griffon & Maubl. The nucleotide sequence of the strain used for pathogenicity tests was submitted to GenBank (Accession No. JN849098). Pathogenicity tests were performed by inoculating 10 avocado fruits after surface disinfesting in 1% sodium hypochlorite and then wounding. Mycelial disks (8 mm in diameter) obtained from PDA cultures of one strain were placed on wounds. Ten control fruits were inoculated with plain PDA. Fruits were incubated at 15 ± 1°C. The first symptoms developed 4 days after the artificial inoculation. After 7 days, the rot was evident and L. theobromae was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice. To our knowledge, this is the first report of the presence of L. theobromae causing postharvest fruit rot on avocado in Italy, as well as in Europe. The occurrence of postharvest fruit rot on avocado caused by L. theobromae was described in many avocado-producing areas such as the United States (4), South Africa, and Israel. In Italy, the economic importance of avocado cultivation is currently limited. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2). P. Narayanasamy. Microbial Plant Pathogens. Detection and Disease Diagnosis: Fungal Pathogens. Springer, Dordrecht, 2011. (3) E. Punithalingam. Sheet 519. CMI Description of Fungi and bacteria, 1976. (4) H. E. Stevens and R. B. Piper. Circular No. 582, USDA, 1941.

5.
J Clin Oncol ; 14(9): 2435-43, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8823321

RESUMEN

PURPOSE: Late solid tumors (STs) are a significant cause of morbidity and mortality in long-term survivors of Hodgkin's disease. To investigate the carcinogenic potential of two different therapeutic approaches, we measured the relative risk (RR) of STs in patients with early-stage disease cured after primary full-dose (approximately 40 Gy) radiation therapy (RT) and in patients with advanced disease who were treated with chemotherapy followed by low-dose (15 to 30 Gy) involved-field radiation (CMT). PATIENTS AND METHODS: Because therapy-induced STs generally begin after a latency period of 5 to 10 years, we restricted our analysis to patients treated before 1986 who achieved durable remissions. Patients who required salvage chemotherapy or who died of Hodgkin's disease were excluded from analysis. The RR of STs was calculated by dividing the observed number of cases by the expected number in a matched population from the Connecticut Tumor Registry. The actuarial incidence of STs was also measured. RESULTS: A total of 197 patients formed the RT group and 116 the CMT group. The median follow-up period in the RT group was 12.8 years, versus 13.5 years in the CMT group. The overall RR of STs in the CMT group was 1.5 (95% confidence interval [CI], 0.6 to 3.5; P = .122). There were no cases of lung or breast cancer. In the RT group, the overall RR of STs was 3.3 (95% CI, 2.0 to 5.3; P < .001). There were seven cases of lung cancer (RR = 10.8; 95% CI, 5.3 to 22.2; P < .001) and two cases of breast cancer (RR = 2; 95% CI, 0.6 to 7.4; P = .07). All six benign tumors occurred in the RT group. CONCLUSION: In patients cured by initial treatment for Hodgkin's disease, RT was associated with a statistically significant increase in STs, particularly lung cancer. CMT was not associated with a significant increase in STs. These data may have important implications for the design of newer therapies for early-stage Hodgkin's disease.


Asunto(s)
Enfermedad de Hodgkin/terapia , Neoplasias Primarias Secundarias/etiología , Análisis Actuarial , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Femenino , Estudios de Seguimiento , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/radioterapia , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/etiología , Radioterapia/efectos adversos , Dosificación Radioterapéutica , Radioterapia Adyuvante , Factores de Riesgo
6.
J Biomater Appl ; 27(7): 840-7, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22262577

RESUMEN

The authors have previously shown that it is possible to incorporate silver into a soda-zinc-silicate glass and subsequently form a glass polyalkenoate cement from it. The objective of the research described herein is to determine if incremental increases in the silver content of these glass polyalkenoate cements will increase their antibacterial efficacy against gram-positive and gram-negative bacteria using the accepted spread plate method. Four glass polyalkenoate cements were formulated; three contained increasing amounts of silver incorporated into them (cements A, B, and C, containing 0.33 mol%, 0.66 mol%, and 0.99 mol% silver, respectively) and a fourth contained no silver, which acted as a control (control cement). The handling properties of the glass polyalkenoate cements were evaluated, where working times were around 2 min and setting times ranged from 1 h 17 min to 2 h 41 min. Inductively coupled plasma atomic emission spectroscopy was employed to determine silver ion release with cement maturation for up to 14 days. The majority of silver ions were released within the first 24 h, with up to 2 mg/L cumulative ion release recorded up to 14 days. The antibacterial properties of the coatings were evaluated against Staphylococcus aureus and Pseudomonas aeruginosa bacteria. The silver-glass polyalkenoate cements exhibited antibacterial effect against both bacterial strains. The maximum inhibition zones recorded against S. aureus was 14.8 mm (SD ± 1.11) and against P. aeruginosa was 20.6 mm (SD ± 0.81). Cement B had a greater antibacterial effect compared to cement A, however, cements B and C had comparable antibacterial effects after 14 days even though cement C contained 0.33 mol% more silver than B. This indicates that by increasing the silver content in these cements, the antibacterial efficacy increases to a point, but there is a threshold where further silver ion release does not increase the antibacterial effect.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Cementos de Ionómero Vítreo/química , Cementos de Ionómero Vítreo/farmacología , Plata/química , Plata/farmacología , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Humanos , Infecciones por Pseudomonas/tratamiento farmacológico , Pseudomonas aeruginosa/efectos de los fármacos , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Zinc/química , Zinc/farmacología
7.
Am J Emerg Med ; 12(4): 485-8, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8031441

RESUMEN

To determine the safety and efficacy of intravenous adenosine as used in the emergency department (ED) for the treatment of presumed supraventricular tachycardia, the investigators performed a retrospective chart review in an urban, university-affiliated ED. Seventy-two consecutive patients were treated with intravenous adenosine for presumed supraventricular tachycardia. Of the 72 patients who were treated with adenosine, 46 patients had a confirmed diagnosis of supraventricular tachycardia. Of these, 39 of 46 (84.8%) converted to sinus rhythm after treatment. Of patients who successfully converted to sinus rhythm, none had recurrent tachycardia or required additional pharmacotherapy. Arrhythmias not successfully treated among the initially misdiagnosed patients were atrial fibrillation (n = 11), atrial flutter (n = 7), tachycardia of other origin (n = 5), and ventricular tachycardia (n = 2). No clinically significant adverse effects were noted among the study population. Intravenous adenosine is a safe and efficacious treatment for the emergent treatment of supraventricular tachycardia, including unstable patients (with hypotension and/or chest pain). It is also safe among patients initially presumed to have supraventricular tachycardia, who are later diagnosed with other arrhythmias.


Asunto(s)
Adenosina/uso terapéutico , Taquicardia Supraventricular/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/tratamiento farmacológico , Arritmias Cardíacas/epidemiología , Errores Diagnósticos , Electrocardiografía , Servicio de Urgencia en Hospital , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/epidemiología , Resultado del Tratamiento
8.
Infect Immun ; 68(7): 4368-9, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10858263

RESUMEN

Anaerobically grown Neisseria gonorrhoeae has previously been shown to have elevated serum resistance in the absence of exogenous CMP-N-acetylneuraminic acid or detectable sialylation. We hypothesized that the anaerobically induced gonococcal outer membrane protein AniA might have a role in this phenomenon, as it is the only known gonococcal protein that is absent under aerobic conditions. An N. gonorrhoeae F62 derivative, RUG7035, in which aniA is under control of the tac promoter, was used to examine the effect of AniA expression on serum resistance. In this study, we found that expression of AniA enhanced the serum resistance of N. gonorrhoeae and may account for these earlier observations.


Asunto(s)
Antígenos Bacterianos/inmunología , Proteínas de la Membrana Bacteriana Externa/inmunología , Actividad Bactericida de la Sangre/inmunología , Neisseria gonorrhoeae/inmunología , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Femenino , Expresión Génica , Genes Bacterianos , Humanos , Técnicas In Vitro , Neisseria gonorrhoeae/genética
9.
Infect Immun ; 68(9): 5241-6, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10948150

RESUMEN

The gene encoding a nitric oxide reductase has been identified in Neisseria gonorrhoeae. The norB gene product shares significant identity with the nitric oxide reductases in Ralstonia eutropha and Synechocystis sp. and, like those organisms, the gonococcus lacks a norC homolog. The gonococcal norB gene was found to be required for anaerobic growth, but the absence of norB did not dramatically decrease anaerobic survival. In a wild-type background, induction of norB expression was seen anaerobically in the presence of nitrite but not anaerobically without nitrite or aerobically. norB expression is not regulated by FNR or NarP, but a functional aniA gene (which encodes an anaerobically induced outer membrane nitrite reductase) is necessary for expression. When aniA is constitutively expressed, norB expression can be induced both anaerobically and aerobically, but only in the presence of nitrite, suggesting that nitric oxide, which is likely to be produced by AniA as a product of nitrite reduction, is the inducing agent. This was confirmed with the use of the nitric oxide donor, spermine-nitric oxide complex, in an aniA null background both anaerobically and aerobically. NorB is important for gonococcal adaptation to an anaerobic environment, a physiologically relevant state during gonococcal infection. The presence of this enzyme, which is induced by nitric oxide, may also have implications in immune evasion and immunomodulation in the human host.


Asunto(s)
Proteínas de Escherichia coli , Genes Bacterianos , Neisseria gonorrhoeae/genética , Óxido Nítrico/fisiología , Oxidorreductasas/genética , Secuencia de Aminoácidos , Anaerobiosis , Antígenos Bacterianos/fisiología , Proteínas de la Membrana Bacteriana Externa/fisiología , Proteínas Bacterianas/fisiología , Secuencia de Bases , Proteínas de Unión al ADN/fisiología , Humanos , Datos de Secuencia Molecular , Neisseria gonorrhoeae/crecimiento & desarrollo , Oxidorreductasas/fisiología
10.
Gynecol Oncol ; 23(2): 199-204, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3943762

RESUMEN

Carcinoma of the uterine cervix presenting with extension to the lower third of the vagina but without hydronephrosis or fixation to the pelvic sidewall is uncommon. It is classified as stage IIIA by the criteria of the International Federation of Gynecology and Obstetrics (FIGO) and accounts for less than 2% of all cervical cancer cases seen in our institution. Because of the paucity of such cases, the results of treatment of FIGO stage IIIA cervical cancer are generally not reported separately. The radiation therapy treatment program at Yale--New Haven Hospital for stage IIIA patients includes intracavitary and vaginal brachytherapy plus external beam radiation therapy, with a strong emphasis on individualization of treatment. The results of treatment in 17 stage IIIA patients were reviewed. Local--regional tumor control was achieved in 12 of the 17 patients (71%) treated. The actuarial 5-year disease-free survival rate was 58%. Our results suggest that FIGO stage IIIA carcinoma of the cervix has a much better prognosis than FIGO stage IIIB cervical cancer, and we recommend that the results of treatment for FIGO stage IIIA be reported separately.


Asunto(s)
Adenocarcinoma/radioterapia , Carcinoma de Células Escamosas/radioterapia , Neoplasias del Cuello Uterino/radioterapia , Adenocarcinoma/mortalidad , Adulto , Anciano , Braquiterapia , Carcinoma de Células Escamosas/mortalidad , Femenino , Humanos , Persona de Mediana Edad , Invasividad Neoplásica , Recurrencia Local de Neoplasia , Radioterapia/métodos , Estudios Retrospectivos , Neoplasias del Cuello Uterino/mortalidad , Neoplasias Vaginales/secundario
11.
Mol Microbiol ; 37(4): 839-55, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10972806

RESUMEN

Analysis of the Neisseria gonorrhoeae DNA sequence database revealed the presence of two genes, one encoding a protein predicted to be 37. 5% identical (50% similar) in amino acid sequence to the Escherichia coli FNR protein and the other encoding a protein 41% and 42% identical (54 and 51% sequence similarity) to the E. coli NarL and NarP proteins respectively. Both genes have been cloned into E. coli and insertionally inactivated in vitro. The mutated genes have been transformed into gonococci and recombined into the chromosome. The fnr mutation totally abolished and the narP mutation severely diminished the ability of gonococci to: (i) grow anaerobically; (ii) adapt to oxygen-limited growth; (iii) initiate transcription from the aniA promoter (which directs the expression of a copper-containing nitrite reductase, AniA, in response to the presence of nitrite); and (iv) reduce nitrite during growth in oxygen-limited media. The product of nitrite reduction was identified to be nitrous oxide. Immediately upstream of the narL/narP gene is an open reading frame that, if translated, would encode a homologue of the E. coli nitrate- and nitrite-sensing proteins NarX and NarQ. As transcription from the aniA promoter was not activated during oxygen-limited growth in the presence of nitrate, the gonococcal two-component regulatory system is designated NarQ-NarP rather than NarX-NarL. As far as we are aware, this is the first well-documented example of a two-component regulatory system working in partnership with a transcription activator in pathogenic neisseria. A 45 kDa c-type cytochrome that was synthesized during oxygen-limited, but not during oxygen sufficient, growth was identified as a homologue of cytochrome c peroxidases (CCP) of other bacteria. The gene for this cytochrome, designated ccp, was located, and its regulatory region was cloned into the promoter probe vector pLES94. Transcription from the ccp promoter was repressed during aerobic growth and induced during oxygen-limited growth and was totally FNR dependent, suggesting that the gonococcal FNR protein is a transcription activator of at least two genes. However, unlike AniA, synthesis of the CCP homologue was insensitive to the presence of nitrite during oxygen-limited growth.


Asunto(s)
Adaptación Fisiológica , Neisseria gonorrhoeae/fisiología , Transactivadores/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Grupo Citocromo c/metabolismo , ADN Bacteriano , Escherichia coli/genética , Genes Bacterianos , Datos de Secuencia Molecular , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/crecimiento & desarrollo , Neisseria gonorrhoeae/metabolismo , Nitritos/metabolismo , Regiones Promotoras Genéticas , Homología de Secuencia de Aminoácido
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