RESUMO
BACKGROUND: Castration-resistant prostate cancer (CRPC) patients have poor prognoses, and docetaxel (DTX) is among the few treatment options. An accurate risk classification to identify CRPC patient groups for which DTX would be effective is urgently warranted. The Armstrong risk classification (ARC), which classifies CRPC patients into 3 groups, is superior; however, its usefulness remains unclear, and further external validation is required before clinical use. This study aimed to examine the clinical significance of the ARC through external validation in DTX-treated Japanese CRPC patients. METHODS: CRPC patients who received 2 or more DTX cycles were selected for this study. Patients were classified into good-, intermediate-, and poor-risk groups according to the ARC. Prostate-specific antigen (PSA) responses and overall survival (OS) were calculated and compared between the risk groups. A multivariate analysis was performed to clarify the relationship between the ARC and major patient characteristics. RESULTS: Seventy-eight CRPC patients met the inclusion criteria. Median PSA levels at DTX initiation was 20 ng/mL. Good-, intermediate-, and poor-risk groups comprised 51 (65%), 17 (22%), and 10 (13%) patients, respectively. PSA response rates ≥ 30% and ≥ 50% were 33%, 41%, and 30%, and 18%, 41%, and 20% in the good-, intermediate-, and poor-risk groups, respectivcixely, with no significant differences (p = 0.133 and 0.797, respectively). The median OS in the good-, intermediate-, and poor-risk groups were statistically significant (p < 0.001) at 30.1, 14.2, and 5.7 months, respectively. A multivariate analysis revealed that the ARC and PSA doubling time were independent prognostic factors. CONCLUSIONS: Most of CRPC patients were classified into good-risk group according to the ARC and the ARC could predict prognosis in DTX-treated CRPC patients. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) number, UMIN000011969.
Assuntos
Modelos de Riscos Proporcionais , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/diagnóstico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Medição de Risco/métodos , Taxoides/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/sangue , Docetaxel , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias de Próstata Resistentes à Castração/classificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
BACKGROUND: To elucidate whether Hand-Foot skin reaction could become a biomarker of clinical outcome in patients with metastatic renal cell carcinoma treated with sorafenib, we retrospectively examined the association between the Hand-Foot skin reaction and the clinical outcome in metastatic renal cell carcinoma patients treated with sorafenib. METHODS: Thirty-six Japanese metastatic renal cell carcinoma patients treated with sorafenib were enrolled and divided into the groups with or without Hand-Foot skin reaction. Patient characteristics, best tumor response, progression-free survival and adverse events were investigated and compared between these two groups. RESULTS: A sorafenib-induced Hand-Foot skin reaction in metastatic renal cell carcinoma patients was observed at a significantly higher rate in patients in the favorable-risk group in the Memorial Sloan-Kettering Cancer Center risk classification, and with Eastern Cooperative Oncology Group Performance Status of one or less, prior nephrectomy, higher hemoglobin, lower lactate dehydrogenase and lower C-reactive protein. The mean best tumor response was significantly better in the group with Hand-Foot skin reaction (-16.7%) than that in the group without it (17.9%; P < 0.001). The median progression-free survival was significantly longer in the group with Hand-Foot skin reaction (4.6 months) than that in the group without it (1.5 months; P = 0.002). In multivariate analysis, only Hand-Foot skin reaction was shown to be a predictive factor of progression-free survival (hazard ratio 0.312, P = 0.010). CONCLUSIONS: A sorafenib-induced Hand-Foot skin reaction in metastatic renal cell carcinoma patients emerged at a significantly higher rate in patients in the favorable-risk group in the Memorial Sloan-Kettering Cancer Center risk classification and was significantly associated with best tumor response and progression-free survival, suggesting that Hand-Foot skin reaction might be an independent predictive factor for clinical outcome in metastatic renal cell carcinoma patients treated with sorafenib.
Assuntos
Antineoplásicos/efeitos adversos , Biomarcadores Tumorais/sangue , Carcinoma de Células Renais/tratamento farmacológico , Síndrome Mão-Pé/etiologia , Neoplasias Renais/tratamento farmacológico , Nefrectomia , Niacinamida/análogos & derivados , Compostos de Fenilureia/efeitos adversos , Adulto , Idoso , Análise de Variância , Antineoplásicos/administração & dosagem , Proteína C-Reativa/metabolismo , Carcinoma de Células Renais/cirurgia , Intervalo Livre de Doença , Feminino , Hemoglobinas/metabolismo , Humanos , Neoplasias Renais/cirurgia , L-Lactato Desidrogenase/sangue , Masculino , Pessoa de Meia-Idade , Niacinamida/administração & dosagem , Niacinamida/efeitos adversos , Compostos de Fenilureia/administração & dosagem , Valor Preditivo dos Testes , Inibidores de Proteínas Quinases/efeitos adversos , Estudos Retrospectivos , Medição de Risco , Sorafenibe , Resultado do TratamentoRESUMO
Mrp systems are widely distributed and structurally complex cation/proton antiporters. Antiport activity requires hetero-oligomeric complexes of all six or seven hydrophobic Mrp proteins (MrpA-MrpG). Here, a panel of site-directed mutants in conserved or proposed motif residues was made in the Mrp Na(+)(Li(+))/H(+) antiporter from an alkaliphilic Bacillus. The mutant operons were expressed in antiporter-deficient Escherichia coli KNabc and assessed for antiport properties, support of sodium resistance, membrane levels of each Mrp protein, and presence of monomeric and dimeric Mrp complexes. Antiport did not depend on a VFF motif or a conserved tyrosine pair, but a role for a conserved histidine in a potential quinone binding site of MrpA was supported. The importance of several acidic residues for antiport was confirmed, and the importance of additional residues was demonstrated (e.g. three lysine residues conserved across MrpA, MrpD, and membrane-bound respiratory Complex I subunits (NuoL/M/N)). The results extended indications that MrpE is required for normal membrane levels of other Mrp proteins and for complex formation. Moreover, mutations in several other Mrp proteins lead to greatly reduced membrane levels of MrpE. Thus, changes in either of the two Mrp modules, MrpA-MrpD and MrpE-MrpG, influence the other. Two mutants, MrpB-P37G and MrpC-Q70A, showed a normal phenotype but lacked the MrpA-MrpG monomeric complex while retaining the dimeric hetero-oligomeric complex. Finally, MrpG-P81A and MrpG-P81G mutants exhibited no antiport activity but supported sodium resistance and a low [Na(+)](in). Such mutants could be used to screen hypothesized but uncharacterized sodium efflux functions of Mrp apart from Na(+) (Li(+))/H(+) antiport.
Assuntos
Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Fases de Leitura Aberta/fisiologia , Multimerização Proteica/fisiologia , Trocadores de Sódio-Hidrogênio/metabolismo , Motivos de Aminoácidos , Bacillus/genética , Proteínas de Bactérias/genética , Sítios de Ligação , Escherichia coli , Mutagênese Sítio-Dirigida , Óperon/fisiologia , Estrutura Quaternária de Proteína , Trocadores de Sódio-Hidrogênio/genéticaRESUMO
A 55-year-old woman had urinary frequency and a constant urge to urinate. Computed tomography confirmed a urethral tumor, and transurethral biopsy confirmed adenocarcinoma. She visited our hospital to undergo treatment, and we performed an anterior pelvic excenteration. On histology, the tumor had spread to the bladder, urethra, and vagina. However, the majority of the tumor was located in the bladder and urethra, a duct with intestinal metaplasia was present around the urethra, and carcinoma in situ was seen in the urethral mucosa. Based on the above findings, the patient was diagnosed as having primary urethral adenocarcinoma. No tumor cells were seen in the resection stump. Six months after surgery, the patient developed bone metastasis, followed by peritoneal and pleural dissemination, as well as multiple lung metastases. The patient died nine months after surgery. In the present patient, the carbohydrate antigen (CA) 19-9 level changed with the clinical course, and it was a useful marker. Urethral tumor is relatively rare. A urethral tumor accompanied by vaginal wall infiltration is likely to be mistaken for a primary vaginal tumor. It was very difficult to identify the primary organ in our case. To the best of our knowledge, the present patient is the sixth reported case of primary urethral carcinoma accompanied by vaginal wall infiltration in Japan. The six reported cases are compared and analyzed.
Assuntos
Adenocarcinoma/patologia , Biomarcadores Tumorais/sangue , Antígeno CA-19-9/sangue , Neoplasias Uretrais/patologia , Vagina/patologia , Adenocarcinoma/secundário , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Neoplasias da Bexiga Urinária/secundário , Neoplasias Vaginais/secundárioRESUMO
Mrp antiporters catalyze secondary Na(+)(Li(+))/H(+) antiport and/or K(+)/H(+) antiport that is physiologically important in diverse bacteria. An additional capacity for anion flux has been observed for a few systems. Mrp is unique among antiporters in that it requires all six or seven hydrophobic gene products (MrpA to MrpG) of the mrp operon for full antiporter activity, but MrpE has been reported to be dispensable. Here, the membrane complexes formed by Mrp proteins were examined using a cloned mrp operon from alkaliphilic Bacillus pseudofirmus OF4. The operon was engineered so that the seven Mrp proteins could be detected in single samples. Membrane extracts of an antiporter-deficient Escherichia coli strain expressing this construct were analyzed by blue native-sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mrp complexes of two sizes were identified containing all seven Mrp proteins. Studies of the single nonpolar mrp gene deletions in the construct showed that a subcomplex of MrpA, MrpB, MrpC, and MrpD was formed in the absence of MrpE, MrpF, or MrpG. By contrast, MrpE, MrpF, and MrpG were not observed in membranes lacking MrpA, MrpB, MrpC, or MrpD. Although MrpA and MrpD have been hypothesized to be the antiporter proteins, the MrpA-to-D complex was inactive. Every Mrp protein was required for an activity level near that of the wild-type Na(+)/H(+) antiporter, but a very low activity level was observed in the absence of MrpE. The introduction of an MrpE(P114G) mutation into the full Mrp complex led to antiport activity with a greatly increased apparent K(m) value for Na(+). The results suggested that interactions among the proteins of heterooligomeric Mrp complexes strongly impact antiporter properties.
Assuntos
Antiporters/genética , Bacillus/genética , Proteínas de Bactérias/genética , Deleção de Genes , Antiporters/metabolismo , Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Eletroforese em Gel de Poliacrilamida , Immunoblotting , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Óperon/genética , Mutação PuntualRESUMO
Cisplatin is a widely used anticancer drug, but its nephrotoxicity is a serious problem. To examine whether the novel biomarker, urinary vanin-1, could predict reduction in renal function after dosing of cisplatin. We conducted a prospective single-center pilot study of 24 patients with urothelial carcinoma who received cisplatin-based chemotherapy between 2012 and 2015. The primary outcome was a 20% or greater decline in estimated glomerular filtration rate (eGFR) from baseline within the first 6days of cisplatin. Urine concentration of creatinine, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL) and NAG (N-acetyl-ß-d-glucosaminidase) as well as vanin-1 were measured during the perioperative period. During 6days after cisplatin, 37.5% (9/24) of patients showed more than 20% decline in eGFR (baseline, 68.8±11.1mL/min/1.73m(2); on day 6, 51.0±2.5mL/min/1.73m(2)) and this reduction persisted until day 10. Urinary vanin-1, but not KIM-1, NGAL and NAG, significantly elevated early on day 3 after cisplatin, which preceded the elevation of serum creatinine on day 6. Sensitivity and specificity of a cutoff point of urinary vanin-1 (9.31ng/mg Cr) on day 3 were calculated to be 66.7% (95% CI: 0.30-0.93) and 83.3% (95% CI: 0.52-0.97), respectively, for predicting 20% decline in eGFR during 6days after cisplatin. These data suggest that urinary vanin-1 is an early predictive biomarker for decline in eGFR in patients with urothelial carcinoma after dosing of cisplatin.
Assuntos
Injúria Renal Aguda/induzido quimicamente , Amidoidrolases/urina , Antineoplásicos/toxicidade , Carcinoma/urina , Cisplatino/toxicidade , Neoplasias Urológicas/urina , Injúria Renal Aguda/fisiopatologia , Injúria Renal Aguda/urina , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Biomarcadores/urina , Carcinoma/tratamento farmacológico , Carcinoma/fisiopatologia , Cisplatino/uso terapêutico , Feminino , Proteínas Ligadas por GPI/urina , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/fisiopatologiaRESUMO
A 46-year-old man underwent polypectomy of sigmoid colon in January 1996. The adenocarcinoma invaded the submucosal layer, and sigmoidectomy and D2 lymph node dissection were performed one month later. Follow-up CT revealed liver metastases, and partial hepatectomy was performed in January 1998. Afterward, weekly high dose intra-hepatic arterial chemotherapy (5-FU: 1,000 mg/body) was performed 41 times, but CT revealed multiple liver metastases in October 1998. Therefore, intra-hepatic arterial infusion of mitomycin C (MMC) with degradable starch microspheres (DSM) was given in November 1998. As follow-up CT revealed that the liver metastases were growing, partial hepatectomy was performed again in March 1999. No carcinoma was seen in the resected liver. After the second hepatectomy, intra-hepatic arterial infusion of MMC with DSM was performed five times. No evidence of recurrence has been seen. Intra-hepatic arterial infusion of MMC with DSM is recommended for liver metastases of colorectal cancer as a second line treatment.
Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/secundário , Antibióticos Antineoplásicos/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Mitomicina/administração & dosagem , Neoplasias do Colo Sigmoide/patologia , Antimetabólitos Antineoplásicos/administração & dosagem , Biodegradação Ambiental , Fluoruracila/administração & dosagem , Hepatectomia , Artéria Hepática , Humanos , Infusões Intra-Arteriais , Masculino , Microesferas , Pessoa de Meia-Idade , Amido/administração & dosagemRESUMO
We studied the pharmacokinetics of CPT-11 with intraperitoneal administration in a patient with a PTCD tube. The patient had advanced gastric cancer with peritoneal metastasis. CPT-11 was administrated in a dose of 40 mg and the intraperitoneal, plasma and bile levels of CPT-11, SN-38 and SN-38 glucuronide (SN-38 GLU) were measured periodically. The results showed that the periodical concentration pattern of CPT-11, SN-38 and SN-38 GLU in the bile was closely related to that of CPT-11 in the abdominal cavity.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/análogos & derivados , Camptotecina/administração & dosagem , Camptotecina/farmacocinética , Glucuronídeos/farmacocinética , Idoso , Idoso de 80 Anos ou mais , Ascite/metabolismo , Bile/química , Humanos , Infusões Parenterais , Irinotecano , Masculino , Neoplasias Gástricas/tratamento farmacológicoRESUMO
We report the pharmacological findings on levofolinate after the intraperitoneal administration of leucovorin-5-FU. Levofolinate 300 mg/saline 500 ml and 5-FU 750 mg/saline 500 ml were administered intraperitoneally over 1.5 h. The plasma and intraperitoneal concentrations of levofolinate at 0, 0.5, 1, 2, 4, 8, 22(20) h after the administration were evaluated at 6 points with HPLC analysis. The intraperitoneal levofolinate concentration went up as high as 100 micrograms/ml and remained above 10 micrograms/ml over 8 hours. This suggested that intraperitoneal administration elevated the portal vein and abdominal lymphatic levofolinate levels. Intraperitoneal levofolinate-5-FU is a promising protocol for gastro-intestinal cancers.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Fluoruracila/farmacologia , Idoso , Neoplasias Colorretais/tratamento farmacológico , Feminino , Fluoruracila/administração & dosagem , Humanos , Bombas de Infusão Implantáveis , Infusões Parenterais/instrumentação , Leucovorina/administração & dosagem , Masculino , Pessoa de Meia-IdadeRESUMO
Staging laparoscopy was carried out for 12 cases of advanced primary gastric cancer to evaluate the condition of peritoneal seeding. Peritoneal seeding was indicated in five cases. Abdominal lavage sampling was positive in six cases. Among six cases with positive cytology, surgery was adopted in three cases to lessen bleeding or stricture. Chemotherapy were carried out for the other three cases. Radical lymph node resection was carried out in six cases without peritoneal seeding. Laparoscopic observation was easier and more feasible under general anesthesia than local anesthesia. Preoperative staging laparoscopy for advanced gastric carcinoma can evaluate the condition of peritoneal seeding. Based on the results, a suitable treatment plan for each patient can be determined.
Assuntos
Laparoscopia , Inoculação de Neoplasia , Estadiamento de Neoplasias/métodos , Neoplasias Peritoneais/secundário , Neoplasias Gástricas/patologia , Anestesia Geral , Anestesia Local , Humanos , Excisão de Linfonodo , Neoplasias Peritoneais/patologiaRESUMO
PURPOSE: To determine if switching from one brand of the α1-adrenoceptor antagonist naftopidil (Avishot™) to another brand (Flivas™) under the same conditions causes the same changes in lower urinary tract symptoms (LUTS) and quality of life (QOL) as the perceived placebo effect, and if ambient temperature as a nonspecific factor is related to those changes in benign prostatic hyperplasia (BPH) patients. PATIENTS AND METHODS: A retrospective study was carried out on 217 BPH patients who had received Avishot™ for more than 6 months and then were switched to Flivas™ at the same dose and timing. The two drugs contain the same principal ingredient and display the same pharmacokinetic properties. The International Prostate Symptom Score (IPSS), QOL score, and average monthly ambient temperature at the patients' residence area from the Automated Meteorological Data Acquisition System in Japan were used for the evaluation. RESULTS: A significant change in urinary storage symptoms (P = 0.006), and especially in nighttime frequency (P< 0.001), was observed by switching drugs, suggesting the perceived placebo effect. There was significant improvement of daytime frequency (P< 0.05), nighttime frequency (P< 0.001), storage symptoms (P< 0.001), and total IPSS (P< 0.05) when the magnitude of ambient temperature change from before and 3 months after switching drugs was higher than 10°C, while no significant improvement was noted in any of the parameters examined when the same was lower than 10°C. CONCLUSION: The present study showed the nonspecific effect of magnitude of ambient temperature change was involved in the perceived placebo effect on LUTS, especially on storage symptoms, by switching drugs. The nonspecific effect on LUTS with BPH needs to be considered when evaluating subjective treatment efficacy of drugs for LUTS with BPH in routine clinical practice. The present study supports the lifestyle advice "avoid exposing the lower body to cold temperature" or "keep warm when it is cold" for LUTS with BPH.
RESUMO
Recently, novel molecular targeted agents markedly changed the treatment of renal cell carcinoma (RCC), with promising results. However, there is little understanding of how these agents affect immune cell populations in RCC, an immunogenic tumor. Therefore, we investigated the changes in the peripheral blood immune cells in 58 RCC patients during the first 4 weeks of treatment with sorafenib, sunitinib, everolimus, or temsirolimus and evaluated whether these changes were associated with clinical outcomes. The immunological parameters were the proportion of type-1 (Th1) and type-2 (Th2) T cells, regulatory T cells (Treg), mature dendritic cells, and the neutrophil-to-lymphocyte ratio (NLR). The changes in these immune cells varied with the agents and the clinical response, dichotomized by the median progression-free survival (PFS) time (PFS-short or PFS-long). A significant decrease in the Th1/Th2 ratio was seen after sunitinib treatment only in the PFS-short group, suggesting a shift toward Th2 that down-regulates host immunity. The NLRs indicative of the balance between host immunity and cancer-related inflammation were consistently lower in the PFS-long group than in the PFS-short group, suggesting that lower NLR is associated with better clinical response. Only sunitinib decreased NLR remarkably regardless of PFS status, which may favor anti-tumor immunity. When patients were dichotomized by the cutoff values, Th1/Th2 ratio was not associated with PFS in any targeted therapy, while lower pre-treatment NLR was associated with longer PFS in each targeted therapy. In addition, in RCC patients given sequential targeted therapy, those with a lower baseline NLR survived significantly longer compared with the counterparts. Moreover, those whose baseline NLR was sustained low during the initial therapy survived the longest. Our results suggest the diverse changes in host immune cells in RCC patients during targeted therapy. The changes in NLR during the early phase of targeted therapy may be a powerful discriminator of who will benefit from the subsequent treatment.
Assuntos
Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/patologia , Imunidade Celular/efeitos dos fármacos , Neoplasias Renais/imunologia , Neoplasias Renais/patologia , Terapia de Alvo Molecular/métodos , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/tratamento farmacológico , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/patologia , Feminino , Humanos , Imunidade Celular/imunologia , Neoplasias Renais/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Neutrófilos/patologia , Prognóstico , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th1/patologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Células Th2/patologia , Resultado do TratamentoRESUMO
Onconeural immunity, a cancer-stimulated immune reaction that cross-reacts with neural tissues, is considered to be the principal pathological mechanism for paraneoplastic neurological syndromes (PNS). A common PNS is paraneoplastic cerebellar degeneration (PCD). We had encountered a PCD patient with urothelial carcinomas (UC) of the urinary bladder who was negative for the well-characterized PNS-related onconeural antibodies. In the present study, we aimed to identify a new PCD-related onconeural antibody, capable of recognizing both cerebellar neurons and cancer tissues from the patient, and applied a proteomic approach using mass spectrometry. We identified anti-creatine kinase, brain-type (CKB) antibody as a new autoantibody in the serum and cerebrospinal fluid from the patient. Immunohistochemistry indicated that anti-CKB antibody reacted with both cerebellar neurons and UC of the urinary bladder tissues. However, anti-CKB antibody was not detected in sera from over 30 donors, including bladder cancer patients without PCD, indicating that anti-CKB antibody is required for onset of PCD. We also detected anti-CKB antibody in sera from three other PCD patients. Our study demonstrated that anti-CKB antibody may be added to the list of PCD-related autoantibodies and may be useful for diagnosis of PCD.
Assuntos
Anticorpos/metabolismo , Encéfalo/metabolismo , Creatina Quinase/imunologia , Degeneração Paraneoplásica Cerebelar/patologia , Idoso , Encéfalo/patologia , Eletroforese em Gel Bidimensional , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , Espectrometria de Massas , Proteínas do Tecido Nervoso/metabolismo , Degeneração Paraneoplásica Cerebelar/sangue , Degeneração Paraneoplásica Cerebelar/líquido cefalorraquidiano , Degeneração Paraneoplásica Cerebelar/imunologiaRESUMO
Monovalent cation proton antiporter-3 (Mrp) family antiporters are widely distributed and physiologically important in prokaryotes. Unlike other antiporters, they require six or seven hydrophobic gene products for full activity. Standard fluorescence-based assays of Mrp antiport in membrane vesicles from Escherichia coli transformants have not yielded strong enough signals for characterization of antiport kinetics. Here, an optimized assay protocol for vesicles of antiporter-deficient E. coli EP432 transformants produced higher levels of secondary Na(+)(Li(+))/H(+) antiport than previously reported. Assays were conducted on Mrps from alkaliphilic Bacillus pseudofirmus OF4 and Bacillus subtilis and the homologous antiporter of Staphylococcus aureus (Mnh), all of which exhibited Na(+)(Li(+))/H(+) antiport. A second paralogue of S. aureus (Mnh2) did not. K(+), Ca(2+), and Mg(2+) did not support significant antiport by any of the test antiporters. All three Na(+)(Li(+))/H(+) Mrp antiporters had alkaline pH optima and apparent K(m) values for Na(+) that are among the lowest reported for bacterial Na(+)/H(+) antiporters. Using a fluorescent probe of the transmembrane electrical potential (DeltaPsi), Mrp Na(+)/H(+) antiport was shown to be DeltaPsi consuming, from which it is inferred to be electrogenic. These assays also showed that membranes from E. coli EP432 expressing Mrp antiporters generated higher DeltaPsi levels than control membranes, as did membranes from E. coli EP432 expressing plasmid-borne NhaA, the well-characterized electrogenic E. coli antiporter. Assays of respiratory chain components in membranes from Mrp and control E. coli transformants led to a hypothesis explaining how activity of secondary, DeltaPsi-consuming antiporters can elicit increased capacity for DeltaPsi generation in a bacterial host.
Assuntos
Bacillus/metabolismo , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Potenciometria , Trocadores de Sódio-Hidrogênio/metabolismo , Staphylococcus aureus/metabolismo , Escherichia coli/genética , Hidrogênio/metabolismo , Lítio/metabolismo , Potenciais da Membrana , Membranas/metabolismo , Sódio/metabolismo , Transformação GenéticaRESUMO
A 47-year-old man was diagnosed with primary aldosteronism due to two left adrenal adenomas, suggested on computed tomography (CT) to be located at the upper and lower adrenal portion. However, adosterol scintigraphy revealed negligible uptake at the upper portion of the left adrenal. Laparoscopic left adrenalectomy was performed, but macroscopic examination of the specimen revealed only one adrenal tumor. Continued surgical exploration detected another mass between the spleen and the stomach, which was demonstrated to be continuous with the stomach and was eventually diagnosed as a gastric diverticulum. Postoperatively, aldosteronism resolved and repeat CT revealed staining of the adrenal pseudotumor when oral contrast was administered. Since organs located near the adrenals can simulate adrenal tumors, caution must be exercised in interpreting suprarenal masses on CT. To our knowledge, this is the first reported case of concurrent pseudotumor and true tumor of the ipsilateral adrenal.