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2.
J Synchrotron Radiat ; 28(Pt 3): 688-706, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33949979

RESUMO

The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump-probe X-ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X-ray heating and diffraction of Bi under pressure, obtained using 20 fs X-ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC.

3.
Phys Rev Lett ; 126(1): 015703, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33480771

RESUMO

We present results from the SPring-8 Angstrom Compact free electron LAser facility, where we used a high intensity (∼10^{20} W/cm^{2}) x-ray pump x-ray probe scheme to observe changes in the ionic structure of silicon induced by x-ray heating of the electrons. By avoiding Laue spots in the scattering signal from a single crystalline sample, we observe a rapid rise in diffuse scattering and a transition to a disordered, liquidlike state with a structure significantly different from liquid silicon. The disordering occurs within 100 fs of irradiation, a timescale that agrees well with first principles simulations, and is faster than that predicted by purely inertial behavior, suggesting that both the phase change and disordered state reached are dominated by Coulomb forces. This method is capable of observing liquid scattering without masking signal from the ambient solid, allowing the liquid structure to be measured throughout and beyond the phase change.

4.
Rev Sci Instrum ; 91(12): 123501, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379989

RESUMO

Small angle x-ray scattering (SAXS) is a well established technique to detect nanometer scale structures in matter. In a typical setup, this diagnostic uses a detector with a direct line of sight to the scattering target. However, in the harsh environment of high intensity laser interaction, intense secondary radiation and high-energy particles are generated. Such a setup would therefore suffer a significant increase of noise due to this background, which could eventually prevent such measurements. In this paper, we present a novel tool consisting of a mosaic graphite crystal that works as a mirror for the SAXS signal and allows us to position the detector behind appropriate shielding. This paper studies the performance of this mirror both by experiment at the European XFEL (X-Ray Free-Electron Laser Facility) laboratory and by simulations.

5.
Sci Rep ; 9(1): 602, 2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-30679456

RESUMO

The evolution of bismuth crystal structure upon excitation of its A1g phonon has been intensely studied with short pulse optical lasers. Here we present the first-time observation of a hard x-ray induced ultrafast phase transition in a bismuth single crystal at high intensities (~1014 W/cm2). The lattice evolution was followed using a recently demonstrated x-ray single-shot probing setup. The time evolution of the (111) Bragg peak intensity showed strong dependence on the excitation fluence. After exposure to a sufficiently intense x-ray pulse, the peak intensity dropped to zero within 300 fs, i.e. faster than one oscillation period of the A1g mode at room temperature. Our analysis indicates a nonthermal origin of a lattice disordering process, and excludes interpretations based on electron-ion equilibration process, or on thermodynamic heating process leading to plasma formation.

6.
Food Res Int ; 111: 306-313, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30007690

RESUMO

The objectives of this study were: to evaluate the use of dry distillery grain soluble extract - DDGse to produce yeast biomass and to obtain cell wall (CW), to use the CW as an aflatoxin B1 (AFB1) adsorbent, to study the variation in the composition and thickness of the CW under the influence of DDGse to evaluate their implication on the adsorption process using transmission electron microscopy (TEM) and fourier-transform infrared spectroscopy (FITR). The production of biomass and CW were variable. The CW thickness values showed that S. boulardii strain grown in yeast extract peptone dextrose (YPD) or DDGse medium, with no significant differences observed. The thickness of the CW for S. cerevisiae (RC012 and VM014) were increased when the cells were grown in DDGse medium, the thickness was almost double compared to the values obtained in YPD medium. The spectra IR of each CW in the two culture media shown regions corresponding to polysaccharides, proteins and lipids. Cells grown in DDGse medium adsorbed more AFB1 than those grown in YPD. The CW adsorbed more AFB1 than the same amount of whole cell. Future studies should be done to determine the type of carbohydrates and the relationship between chitin - beta glucans responsible for mycotoxin adsorption.


Assuntos
Aflatoxina B1/análise , Agricultura , Parede Celular/química , Resíduos Industriais , Saccharomyces boulardii/metabolismo , Saccharomyces cerevisiae/metabolismo , Adsorção , Biomassa , Parede Celular/metabolismo , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Nat Commun ; 6: 8742, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26541650

RESUMO

Since the observation of the first brown dwarf in 1995, numerous studies have led to a better understanding of the structures of these objects. Here we present a method for studying material resistivity in warm dense plasmas in the laboratory, which we relate to the microphysics of brown dwarfs through viscosity and electron collisions. Here we use X-ray polarimetry to determine the resistivity of a sulphur-doped plastic target heated to Brown Dwarf conditions by an ultra-intense laser. The resistivity is determined by matching the plasma physics model to the atomic physics calculations of the measured large, positive, polarization. The inferred resistivity is larger than predicted using standard resistivity models, suggesting that these commonly used models will not adequately describe the resistivity of warm dense plasma related to the viscosity of brown dwarfs.

8.
Artigo em Inglês | MEDLINE | ID: mdl-25871224

RESUMO

Fast-electron generation and dynamics, including electron refluxing, is at the core of understanding high-intensity laser-plasma interactions. This field is itself of strong relevance to fast ignition fusion and the development of new short-pulse, intense, x-ray, γ-ray, and particle sources. In this paper, we describe experiments that explicitly link fast-electron refluxing and anisotropy in hard-x-ray emission. We find the anisotropy in x-ray emission to be strongly correlated to the suppression of refluxing. In contrast to some previous work, the peak of emission is directly along the rear normal to the target rather than along either the incident laser direction or the specular reflection direction.

9.
Sci Rep ; 4: 5214, 2014 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-24909903

RESUMO

Here, we report results of an experiment creating a transient, highly correlated carbon state using a combination of optical and x-ray lasers. Scattered x-rays reveal a highly ordered state with an electrostatic energy significantly exceeding the thermal energy of the ions. Strong Coulomb forces are predicted to induce nucleation into a crystalline ion structure within a few picoseconds. However, we observe no evidence of such phase transition after several tens of picoseconds but strong indications for an over-correlated fluid state. The experiment suggests a much slower nucleation and points to an intermediate glassy state where the ions are frozen close to their original positions in the fluid.

10.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(5 Pt 2): 056415, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-23004887

RESUMO

We present data on emission of K-shell radiation from Ti foils irradiated with subpicosecond pulses of second harmonic radiation (527 nm) from the TARANIS laser system at intensities of up to 10(18) W cm(-2). The data are used to demonstrate that a resonance absorption type mechanism is responsible for absorption of the laser light and to estimate fast electron temperatures of 30-60 keV that are in broad agreement with expectation from models of absorption for a steep density gradient. Data taken with resin-backed targets are used to demonstrate clear evidence of electron refluxing even at the modest fast electron temperatures inferred.

11.
Phys Rev Lett ; 105(26): 265701, 2010 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-21231678

RESUMO

Laser-produced proton beams have been used to achieve ultrafast volumetric heating of carbon samples at solid density. The isochoric melting of carbon was probed by a scattering of x rays from a secondary laser-produced plasma. From the scattering signal, we have deduced the fraction of the material that was melted by the inhomogeneous heating. The results are compared to different theoretical approaches for the equation of state which suggests modifications from standard models.

12.
Opt Lett ; 34(17): 2560-2, 2009 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-19724489

RESUMO

We present a method for producing laser beams of nonuniform polarization where the polarization direction rotates on a trajectory about the beam propagation direction. Our method uses a Sagnac interferometer that incorporates a spatial light modulator to combine beams that possess oppositely charged phase vortices in order to achieve the desired polarization vortex. We demonstrate the utility of our method by producing polarization vortices characterized by a fractional index, and we compare the results with calculations of the expected fields.

13.
Eur J Surg Oncol ; 34(4): 365-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17532172

RESUMO

PURPOSE: Sentinel lymph node biopsy (SNB) has been a standard technique in early breast cancer. However, it is not clear that the SNB procedure can be applied to second breast cancer or recurrence occurring in the previously treated breast. The purpose of this study was to clarify the feasibility of the SNB procedure in breast cancer occurring in the previously treated breast, and to investigate the factors related to altered lymphatic flow. PATIENTS AND METHODS: Between April 2004 and December 2006, 1490 patients underwent the breast SNB procedure. Among them, 31 patients had a history of previous treatments in the same breast. Recent excision biopsy cases were not included in this group. All patients had previous breast-conserving surgery in the same breast. Sixteen patients had axillary dissection, 3 had SNB, and 12 had no axillary treatment. Ten patients had received radiation therapy to the breast and axilla. Visualization of axillary nodes, internal mammary nodes and contralateral axillary nodes was evaluated and compared with pathological results. RESULTS: Axillary nodes were visualized in 23 patients, internal mammary nodes in 7 patients, and contralateral axillary nodes in 7 patients. The patients with previous axillary dissection exhibited altered lymph node distribution, but did not show involvement of contralateral axillary nodes. Visualization of contralateral axillary nodes occurred in 7 of the 10 patients with previous irradiation to breast irrespective of axillary dissection. Twenty-eight patients underwent SNB, 4 of whom showed cancer-positive nodes. Three patients were cancer-positive in non-ipsilateral axillary nodes (one patient showed positive opposite axillary node and two patients showed positive internal mammary nodes). CONCLUSION: Previous axillary dissection or irradiation to the breast greatly influences lymphatic flow. Irradiation to the breast may be a strong factor for the visualization of contralateral axillary nodes. Despite the frequent alteration of lymphatic flow, SNB seems to be feasible in secondary or recurrent breast cancer patients.


Assuntos
Neoplasias da Mama/patologia , Recidiva Local de Neoplasia/patologia , Segunda Neoplasia Primária/patologia , Biópsia de Linfonodo Sentinela , Axila , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Excisão de Linfonodo , Sistema Linfático/efeitos da radiação , Sistema Linfático/cirurgia , Mastectomia Segmentar
14.
Breast J ; 12(5 Suppl 2): S181-90, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16958999

RESUMO

When breast-conserving therapy was introduced at the Cancer Institute Hospital (CIH) in Tokyo in 1986, we instituted our own strategy as follows: 1) every effort is to be made for complete tumor resection while avoiding deformity of the breast, and 2) radiotherapy (RT) is applied only to the patients with positive surgical margins. This is, in turn, to clarify the group of patients in whom postoperative RT can be safely spared. Among 9670 patients operated on for primary breast cancer during the 16.5 year period from 1986 to 2002 at CIH, there were 2449 patients who underwent breast-conserving surgery (BCS). During the 6.5 years mean follow-up period, ipsilateral intrabreast tumor recurrence (IBTR) developed in 99 of the 2449 patients, with an overall rate of 4.0% and an annual rate of 0.62%. These 2449 patients were categorized into four subgroups according to either negative or positive margins and with or without radiotherapy. The IBTR rates and the number of patients in each subgroup were 5.5% in 1351 margin(-)RT(-) patients, 1.0% in 307 margin(-)RT(+) patients, 2.4% in 680 margin(+)RT(+) patients, and 4.5% in 111 margin(+)RT(-) patients. These results either with or without RT seem to be quite comparable to or even better than the results of BCS with RT reported from Western countries, where less emphasis seems to be placed on completeness of the local tumor resection with BCS, while RT is administered to basically all patients following BCS. IBTR was categorized into true recurrence (TR) and second primary lesion (SP) according to the margin status at the time of BCS, the former being lesions developed in patients with positive margins and the latter being those in patients with negative margins. It was demonstrated that in patients with positive margins, TR was much more common than SP, whereas in patients with negative margins, these incidences were just the opposite (i.e., TR was 60% less common than SP) and postoperative RT was effective in preventing both TR and SP, the effect on the latter being much more striking. With RT, the incidence of developing TR in patients who had positive margins was reduced to almost equal to that in margin(-) patients treated with no RT. Our method of IBTR categorization is based on biological consideration and detailed histopathologic examination, and appears to be the only biologically reasonable means so far that has been proposed for distinction between these two biologically different entities. TR and SP can be further reduced to exceptionally low levels in patients who received RT despite negative margins, though it would not seem reasonable to administer RT to all of these patients because the actual number of patients who would benefit is comparatively small. From these observations, it seems that our imaging, pathologic examination, and surgical approaches for patients who are candidates for BCS have been highly valid, and our criteria for sparing postoperative RT as well as categorization of IBTR into TR and SP are quite appropriate. Although our results with BCS seem to deserve wide recognition, they are not from randomized clinical trials, so the findings must be confirmed by a study in order to investigate whether the results at CIH can be applied generally at other institutions.


Assuntos
Neoplasias da Mama/mortalidade , Neoplasias da Mama/cirurgia , Mastectomia Segmentar , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/cirurgia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Humanos , Japão/epidemiologia , Prontuários Médicos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Estadiamento de Neoplasias , Radioterapia Adjuvante , Estudos Retrospectivos , Análise de Sobrevida
15.
Eur J Surg Oncol ; 32(7): 738-42, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16806793

RESUMO

AIMS: Methods of administering (99m)Tc-phytate during sentinel node biopsy of early breast cancer patients were compared to improve the sensitivity of the technique. METHODS: Two injection methods, intradermal vs. intradermal-plus-deep injection, were compared in 648 early breast cancer patients. Intradermal injection was done in 323 consecutive patients (325 breasts), and intradermal-plus-deep injection was done in 325 consecutive patients (329 breasts). The following items were compared: (1) The number of axillary nodes detected scintigraphically and removed surgically, and the breast number of micrometastasis to axillary nodes; (2) The number of internal mammary nodes detected scintigraphically and removed surgically; and (3) The sensitivity of axillary SNB. RESULTS: The number of axillary nodes scintigraphically detected was 1.63+/-0.80 (mean+/-SD) in patients given intradermal injection, and was 1.82+/-0.94 in patients given intradermal-plus-deep injection. The number of axillary nodes surgically removed was 1.78+/-0.93 in patients given intradermal injection, and was 1.95+/-0.99 in patients given intradermal-plus-deep injection. The visualization of internal mammary nodes was superior with intradermal-plus-deep injection (5/325 for intradermal, and 51/329 for intradermal-plus-deep). The putative sensitivity was 71/72 (98.6%) for the intradermal-plus-deep method and 56/62 (90.3%) for the intradermal method. The frequency of detection of micrometastasis was 24 in 71 true positive (38.8%) for the intradermal-plus-deep method and 13 in 56 true positive (23.2%) for the intradermal method. CONCLUSIONS: The SNB procedure with the intradermal-plus-deep injection method detected more axillary and internal mammary nodes, more (not statistically significant) micrometastasis and improved the putative sensitivity more than the SNB procedure with the intradermal injection method.


Assuntos
Neoplasias da Mama/patologia , Compostos de Organotecnécio/administração & dosagem , Ácido Fítico/administração & dosagem , Compostos Radiofarmacêuticos/administração & dosagem , Biópsia de Linfonodo Sentinela , Axila , Mama , Feminino , Humanos , Injeções Intradérmicas , Linfonodos/patologia , Metástase Linfática , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Biópsia de Linfonodo Sentinela/métodos
16.
Eur J Surg Oncol ; 32(10): 1101-4, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16626922

RESUMO

AIMS: The aim of the present study is to clarify the level of radioactive lymph node should be biopsied after the most radioactive SN is removed. METHODS: SNB using radionuclide was performed in our hospital for 1179 primary breast cancers between April 2000 and October 2005; most (1177/1179) were performed successfully. Our criterion for harvesting SNs is to remove tissue until no radioactive site is present. The level of radioactivity and the order of removal of each lymph node were compared with pathologic results. RESULTS: More than 2 (overall average 1.9) radioactive SNs were biopsied in 686 of 1177 breasts. Cancer positive results were recorded for 142 breasts with multiple SNs. In 142 breasts, 64 showed metastasis to the most radioactive node only, 39 showed metastasis other than the most radioactive node only, and 39 showed the most radioactive node and other radioactive nodes. Moreover, if several other criteria were applied, false-positive cases were increased significantly. CONCLUSIONS: It is necessary to harvest radioactive lymph nodes other than the most radioactive. Moreover, efforts to remove every radioactive lymph node will minimize false-negative results.


Assuntos
Neoplasias da Mama/patologia , Linfonodos/efeitos da radiação , Compostos de Organotecnécio , Ácido Fítico , Compostos Radiofarmacêuticos , Rênio , Biópsia de Linfonodo Sentinela , Compostos de Tecnécio , Axila , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Humanos , Doses de Radiação
17.
Eur J Surg Oncol ; 31(8): 840-4, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16009528

RESUMO

AIMS: To study the significance of lymphatic drainage disruption due to a surgical scar in sentinel node mapping (SNM) in breast cancer patients. METHODS: We reviewed patients with stage I breast cancer who had undergone SNM and had an old surgical scar in the ipsilateral breast. RESULTS: Of 534 breast cancer patients who had undergone SNM, five patients had an old scar in the ipsilateral breast. Inter-pectoral nodes, internal nodes, intramammary nodes, and contralateral axillary nodes were identified as sentinel nodes in three cases. In the remaining two cases, no sentinel lymph nodes were identified. CONCLUSIONS: An old surgical scar in the breast may cause lymphatic drainage disruption, resulting in abnormal radioactive colloid uptake during SNM.


Assuntos
Neoplasias da Mama/patologia , Cicatriz/patologia , Biópsia de Linfonodo Sentinela/métodos , Idoso , Axila , Mama , Carcinoma in Situ/patologia , Carcinoma in Situ/cirurgia , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Corantes , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Mastectomia , Mastectomia Segmentar , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Músculos Peitorais , Cintilografia , Compostos Radiofarmacêuticos
18.
Eur J Surg Oncol ; 30(10): 1077-83, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15522554

RESUMO

AIM: Large multicenter, randomized trials have revealed the advantages of using tamoxifen for 5 years vs 2 years in breast cancer patients. The aim of this report is to confirm the optimal duration of tamoxifen administration in a study of Japanese breast cancer patients. METHODS: Japanese post-menopausal estrogen receptor-positive breast cancer patients treated with mastectomy were randomly assigned to either a 5-year or 2-year course of tamoxifen. The primary endpoint was disease-free survival, with secondary endpoints of overall survival and a reduction in the development of metachronous contra-lateral breast cancer. RESULTS: A total of 256 breast cancer patients were randomized to a 5-year or 2-year tamoxifen administration group. After a median follow-up time of 81 months, there were no significant differences seen in terms of disease-free or overall survival (p=0.65 and 0.56, respectively). Furthermore, the impact of the 5-year use of tamoxifen on the development of contra-lateral breast cancer did not reach statistical significance (p=0.0511). However, 5-year tamoxifen use was closely associated with gynaecological complications (p=0.0081). CONCLUSION: We could not show a beneficial effect of using tamoxifen for 5 years over 2 years in Japanese estrogen receptor-positive patients. This is likely due to the small number of patients enrolled in our study; however, racial disparity may influence this result. A reevaluation is necessary to study the advantages of the 5-year use of tamoxifen in the Japanese racial subgroup.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Antagonistas de Estrogênios/uso terapêutico , Pós-Menopausa , Tamoxifeno/uso terapêutico , Adulto , Idoso , Antineoplásicos Hormonais/efeitos adversos , Povo Asiático/etnologia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Antagonistas de Estrogênios/efeitos adversos , Feminino , Seguimentos , Doenças dos Genitais Femininos/induzido quimicamente , Humanos , Japão/etnologia , Metástase Linfática/patologia , Mastectomia , Pessoa de Meia-Idade , Segunda Neoplasia Primária/prevenção & controle , Receptores de Estrogênio/análise , Taxa de Sobrevida , Tamoxifeno/efeitos adversos
19.
Br J Cancer ; 89(9): 1627-32, 2003 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-14583760

RESUMO

Preclinical studies have demonstrated the synergistic anti-tumour activity of combination therapy with the oral cytostatics, 5'-deoxy-5-fluorouridine (5'-DFUR) and cyclophosphamide (CPA), in human breast cancer xenograft models. This study was performed to evaluate the efficacy and safety of this oral combination chemotherapy in the treatment of metastatic breast cancer. In all, 101 patients with metastatic breast cancer were enrolled in the study, and the data for 94 eligible patients of these were evaluated. The patients received twice daily oral combinations of 5'-DFUR (1200 mg/body/day) and CPA (100 mg/body/day) for 2 weeks, followed by a 1-week rest period. After a median of 19 treatment cycles (range 1-66 cycles), 16 patients (17.0%) had a complete response, and 40 patients (42.6%) had partial responses. The response rate was 59.6% (95% CI, 49.0-69.6%). The median time to progression and overall survival times were 11.7 and 40.3 months, respectively. The toxicity was mild and tolerable, and the related grade 3/4 clinical adverse effects consisted of haematological toxicity in 21 patients (22%) and nonhaematological toxicity in five patients (5%). These results suggest that the oral combination chemotherapy of 5'-DFUR and CPA has low toxicity and is a novel, very convenient and effective treatment for metastatic breast cancer.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Administração Oral , Adulto , Idoso , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Ciclofosfamida/uso terapêutico , Feminino , Floxuridina/uso terapêutico , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Pró-Fármacos/uso terapêutico , Taxa de Sobrevida , Resultado do Tratamento
20.
Ann Hematol ; 82(7): 448-51, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12750844

RESUMO

Ectopic hormone production is very rare in hematological malignancy. Here, we describe an interesting case of acute lymphoblastic leukemia (ALL) with adrenocorticotropic hormone (ACTH) production. A 47-year-old man was admitted to our hospital with a 7-month history of hyperpigmentation. The plasma level of ACTH was markedly elevated without a circadian rhythm and the level of cortisol was normal. Examination of bone marrow aspiration revealed ALL, and no other disease as a cause of the elevated ACTH was detected. Sephadex G-75 chromatography of plasma ACTH extract revealed the existence of an abnormally large molecular ACTH (probably proopiomelanocortin) in addition to authentic 1-39 ACTH. Ectopic ACTH of low biological activity is considered to be the reason for a discrepancy in the plasma levels of ACTH and cortisol. Shortly after remission induction chemotherapy, blast cells in the peripheral blood disappeared, and the plasma level of ACTH became normal, leading to an improvement of skin pigmentation. These clinical findings and laboratory data suggested that leukemia cells in this case may produce the ACTH.


Assuntos
Hormônio Adrenocorticotrópico/biossíntese , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Hormônio Adrenocorticotrópico/sangue , Ritmo Circadiano , Humanos , Hidrocortisona/sangue , Hiperpigmentação , Masculino , Pessoa de Meia-Idade , Peso Molecular , Indução de Remissão
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