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1.
Opt Lett ; 47(12): 3063-3066, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35709050

RESUMO

We experimentally demonstrate a 400 Gbit/s optical communication link utilizing wavelength-division multiplexing and mode-division multiplexing for a total of 40 channels. This link utilizes a novel, to the best of our knowledge, 400 GHz frequency comb source based on a chip-scale photonic crystal resonator. Silicon-on-insulator photonic inverse-designed 4 × 4 mode-division multiplexer structures enable a fourfold increase in data capacity. We show less than -10 dBm of optical receiver power for error-free data transmission in 34 out of a total of 40 channels using a PRBS31 pattern.

2.
J Appl Microbiol ; 129(2): 311-318, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32052540

RESUMO

AIMS: The aim of this study was to develop a novel selective agar for the specific isolation and detection of Bacillus anthracis. METHODS AND RESULTS: Based on published data on antibiotic resistance and susceptibility of B. anthracis and other closely related species of the Bacillus cereus sensu lato group, a new selective agar formulation termed CEFOMA (Bacillus CEreus sensu lato group-specific antibiotics, FOsfomycin, MAcrolides) was developed and evaluated. All tested strains of B. anthracis were able to grow on CEFOMA with the same colony number as on non-selective media, whereas CEFOMA inhibited the growth of the other species within the B. cereus sensu lato group. In comparison to other selective agars, CEFOMA had a superior performance and considerably reduced the total amount of accompanying flora in soil. Furthermore, B. anthracis was successfully isolated from deliberately spiked soil samples. CONCLUSIONS: CEFOMA is a highly promising selective agar for the efficient isolation of B. anthracis from environmental samples with a large bacterial background flora. SIGNIFICANCE AND IMPACT OF THE STUDY: The isolation of B. anthracis from environmental samples is severely impaired by the lack of adequate selective agars which suppress the growth of other bacteria. CEFOMA agar represents an important improvement and suitable alternative to currently used selective agars.


Assuntos
Ágar/química , Bacillus anthracis/isolamento & purificação , Meios de Cultura/química , Ágar/farmacologia , Antibacterianos/análise , Antibacterianos/farmacologia , Bacillus anthracis/crescimento & desenvolvimento , Bacillus cereus/efeitos dos fármacos , Contagem de Colônia Microbiana , Meios de Cultura/farmacologia , Microbiologia do Solo , Especificidade da Espécie
3.
Am J Transplant ; 16(7): 1982-98, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26990570

RESUMO

Interstitial fibrosis and tubular atrophy (IFTA) is found in approximately 25% of 1-year biopsies posttransplant. It is known that IFTA correlates with decreased graft survival when histological evidence of inflammation is present. Identifying the mechanistic etiology of IFTA is important to understanding why long-term graft survival has not changed as expected despite improved immunosuppression and dramatically reduced rates of clinical acute rejection (AR) (Services UDoHaH. http://www.ustransplant.org/annual_reports/current/509a_ki.htm). Gene expression profiles of 234 graft biopsy samples were obtained with matching clinical and outcome data. Eighty-one IFTA biopsies were divided into subphenotypes by degree of histological inflammation: IFTA with AR, IFTA with inflammation, and IFTA without inflammation. Samples with AR (n = 54) and normally functioning transplants (TX; n = 99) were used in comparisons. A novel analysis using gene coexpression networks revealed that all IFTA phenotypes were strongly enriched for dysregulated gene pathways and these were shared with the biopsy profiles of AR, including IFTA samples without histological evidence of inflammation. Thus, by molecular profiling we demonstrate that most IFTA samples have ongoing immune-mediated injury or chronic rejection that is more sensitively detected by gene expression profiling. These molecular biopsy profiles correlated with future graft loss in IFTA samples without inflammation.


Assuntos
Atrofia/mortalidade , Fibrose/mortalidade , Perfilação da Expressão Gênica , Rejeição de Enxerto/mortalidade , Transplante de Rim/métodos , Túbulos Renais/patologia , Nefrite Intersticial/mortalidade , Atrofia/genética , Fibrose/genética , Taxa de Filtração Glomerular , Rejeição de Enxerto/genética , Sobrevivência de Enxerto , Humanos , Falência Renal Crônica/genética , Falência Renal Crônica/cirurgia , Testes de Função Renal , Túbulos Renais/metabolismo , Nefrite Intersticial/genética , Prognóstico , Fatores de Risco , Taxa de Sobrevida
4.
Eur Psychiatry ; 32: 34-41, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26802982

RESUMO

BACKGROUND: Postgraduate medical trainees experience high rates of burnout, but evidence regarding psychiatric trainees is missing. We aim to determine burnout rates among psychiatric trainees, and identify individual, educational and work-related factors associated with severe burnout. METHODS: In an online survey psychiatric trainees from 22 countries were asked to complete the Maslach Burnout Inventory (MBI-GS) and provide information on individual, educational and work-related parameters. Linear mixed models were used to predict the MBI-GS scores, and a generalized linear mixed model to predict severe burnout. RESULTS: This is the largest study on burnout and training conditions among psychiatric trainees to date. Complete data were obtained from 1980 out of 7625 approached trainees (26%; range 17.8-65.6%). Participants were 31.9 (SD 5.3) years old with 2.8 (SD 1.9) years of training. Severe burnout was found in 726 (36.7%) trainees. The risk was higher for trainees who were younger (P<0.001), without children (P=0.010), and had not opted for psychiatry as a first career choice (P=0.043). After adjustment for socio-demographic characteristics, years in training and country differences in burnout, severe burnout remained associated with long working hours (P<0.001), lack of supervision (P<0.001), and not having regular time to rest (P=0.001). Main findings were replicated in a sensitivity analysis with countries with response rate above 50%. CONCLUSIONS: Besides previously described risk factors such as working hours and younger age, this is the first evidence of negative influence of lack of supervision and not opting for psychiatry as a first career choice on trainees' burnout.


Assuntos
Esgotamento Profissional , Psiquiatria/estatística & dados numéricos , Tolerância ao Trabalho Programado/psicologia , Adulto , Esgotamento Profissional/diagnóstico , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/etiologia , Escolha da Profissão , Demografia , Educação Médica Continuada/métodos , Feminino , Humanos , Masculino , Serviços de Saúde Mental/organização & administração , Pessoa de Meia-Idade , Inventário de Personalidade , Fatores de Risco , Fatores Socioeconômicos , Inquéritos e Questionários
5.
Z Gastroenterol ; 51(11): 1235-9, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24243570

RESUMO

BACKGROUND: Celiac disease (CD) is a common chronic systemic autoimmune disease in Europe. The prevalence of CD in Hungarian children is estimated at 1.2 - 1.4 %. To date, however, no data on adult CD prevalence has been published. AIMS: Analysis of the serological evidence for CD among Hungarian adults in order to estimate its prevalence. METHODS: Plasma samples from 4155 healthy blood donors were anonymously screened for circulating IgA autoantibodies by a highly sensitive tissue transglutaminase ELISA. Positive results were subsequently confirmed by endomysial antibody test. RESULTS: Endomysial antibody test confirmed positivity in 25 samples suggesting a prevalence of CD of at least 0.6 % (1:166). Since no identification on the samples was provided, no further examinations could be done on endomysial antibody positive individuals. CONCLUSIONS: The first serological screening study among healthy Hungarian adult blood donors showed a prevalence of CD similar to other central European countries and lower than that in Hungarian children. Among countries worldwide, the Hungarian prevalence of CD appears to be in the mid-range, although pediatric data suggest a higher prevalence.


Assuntos
Autoanticorpos/sangue , Doadores de Sangue/estatística & dados numéricos , Doença Celíaca/diagnóstico , Doença Celíaca/epidemiologia , Programas de Rastreamento/estatística & dados numéricos , Transglutaminases/sangue , Adulto , Biomarcadores/sangue , Doença Celíaca/sangue , Feminino , Humanos , Hungria/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Valores de Referência , Fatores de Risco , Adulto Jovem
6.
Nature ; 468(7322): 412-6, 2010 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-21085175

RESUMO

Quantum networks are composed of quantum nodes that interact coherently through quantum channels, and open a broad frontier of scientific opportunities. For example, a quantum network can serve as a 'web' for connecting quantum processors for computation and communication, or as a 'simulator' allowing investigations of quantum critical phenomena arising from interactions among the nodes mediated by the channels. The physical realization of quantum networks generically requires dynamical systems capable of generating and storing entangled states among multiple quantum memories, and efficiently transferring stored entanglement into quantum channels for distribution across the network. Although such capabilities have been demonstrated for diverse bipartite systems, entangled states have not been achieved for interconnects capable of 'mapping' multipartite entanglement stored in quantum memories to quantum channels. Here we demonstrate measurement-induced entanglement stored in four atomic memories; user-controlled, coherent transfer of the atomic entanglement to four photonic channels; and characterization of the full quadripartite entanglement using quantum uncertainty relations. Our work therefore constitutes an advance in the distribution of multipartite entanglement across quantum networks. We also show that our entanglement verification method is suitable for studying the entanglement order of condensed-matter systems in thermal equilibrium.

7.
Proc Natl Acad Sci U S A ; 107(3): 1005-10, 2010 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-20080573

RESUMO

Recently, remarkable advances have been made in coupling a number of high-Q modes of nano-mechanical systems to high-finesse optical cavities, with the goal of reaching regimes in which quantum behavior can be observed and leveraged toward new applications. To reach this regime, the coupling between these systems and their thermal environments must be minimized. Here we propose a novel approach to this problem, in which optically levitating a nano-mechanical system can greatly reduce its thermal contact, while simultaneously eliminating dissipation arising from clamping. Through the long coherence times allowed, this approach potentially opens the door to ground-state cooling and coherent manipulation of a single mesoscopic mechanical system or entanglement generation between spatially separate systems, even in room-temperature environments. As an example, we show that these goals should be achievable when the mechanical mode consists of the center-of-mass motion of a levitated nanosphere.

8.
Phys Rev Lett ; 103(20): 207204, 2009 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-20366008

RESUMO

We study high-stress SiN films for reaching the quantum regime with mesoscopic oscillators connected to a room-temperature thermal bath, for which there are stringent requirements on the oscillators' quality factors and frequencies. Our SiN films support mechanical modes with unprecedented products of mechanical quality factor Q(m) and frequency nu(m) reaching Q(m)nu(m) approximately or = 2 x 10(13) Hz. The SiN membranes exhibit a low optical absorption characterized by Im(n) < or approximately equal to 10(-5) at 935 nm, representing a 15 times reduction for SiN membranes. We have developed an apparatus to simultaneously cool the motion of multiple mechanical modes based on a short, high-finesse Fabry-Perot cavity and present initial cooling results along with future possibilities.

9.
Phys Rev Lett ; 101(13): 135301, 2008 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-18851457

RESUMO

We report on measurements of the excitation spectrum of a strongly interacting Bose-Einstein condensate. A magnetic-field Feshbach resonance is used to tune atom-atom interactions in the condensate and to reach a regime where quantum depletion and beyond mean-field corrections to the condensate chemical potential are significant. We use two-photon Bragg spectroscopy to probe the condensate excitation spectrum; our results demonstrate the onset of beyond mean-field effects in a gaseous Bose-Einstein condensate.

10.
Phys Rev Lett ; 101(4): 040402, 2008 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-18764310

RESUMO

We report on the observation of controllable phase separation in a dual-species Bose-Einstein condensate with 85Rb and 87Rb. Interatomic interactions between the different components determine the miscibility of the two quantum fluids. In our experiments, we can clearly observe immiscible behavior via a dramatic spatial separation of the two species. Furthermore, a magnetic-field Feshbach resonance is used to change them between miscible and immiscible by tuning the 85Rb scattering length. The spatial density pattern of the immiscible quantum fluids exhibits complex alternating-domain structures that are uncharacteristic of its stationary ground state.

11.
Phys Rev Lett ; 97(18): 180404, 2006 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-17155521

RESUMO

We report on the observation of ultracold heteronuclear Feshbach molecules. Starting with a 87Rb Bose-Einstein condensate and a cold atomic gas of 85Rb, we utilize previously unobserved interspecies Feshbach resonances to create up to 25,000 molecules. Even though the 85Rb gas is nondegenerate, we observe a large molecular conversion efficiency due to the presence of a quantum degenerate 87Rb gas; this represents a key feature of our system. We compare the molecule creation at two different Feshbach resonances with different magnetic-field widths. The two Feshbach resonances are located at 265.44+/-0.15 G and 372.4+/-1.3 G. We also directly measure the small binding energy of the molecules through resonant magnetic-field association.

12.
J Cell Biol ; 160(4): 475-9, 2003 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-12591911

RESUMO

The endoplasmic reticulum is a heterogeneous compartment with respect to the distribution of its Ca2+-handling proteins, namely the Ca2+-binding proteins, the Ca2+ pumps and the Ca2+ release channels. The nonuniform distribution of these proteins may explain the functional heterogeneity of the endoplasmic reticulum, such as the generation of spatially complex Ca2+ signals, Ca2+ homeostasis, and protein folding and quality control.


Assuntos
Sinalização do Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Animais , Canais de Cálcio/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Homeostase , Humanos , Chaperonas Moleculares/metabolismo , Oócitos/citologia , Oócitos/metabolismo
13.
J Cell Biol ; 154(5): 961-72, 2001 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-11524434

RESUMO

Calreticulin is a Ca2+-binding chaperone in the endoplasmic reticulum (ER), and calreticulin gene knockout is embryonic lethal. Here, we used calreticulin-deficient mouse embryonic fibroblasts to examine the function of calreticulin as a regulator of Ca2+ homeostasis. In cells without calreticulin, the ER has a lower capacity for Ca2+ storage, although the free ER luminal Ca2+ concentration is unchanged. Calreticulin-deficient cells show inhibited Ca2+ release in response to bradykinin, yet they release Ca2+ upon direct activation with the inositol 1,4,5-trisphosphate (InsP3). These cells fail to produce a measurable level of InsP3 upon stimulation with bradykinin, likely because the binding of bradykinin to its cell surface receptor is impaired. Bradykinin binding and bradykinin-induced Ca2+ release are both restored by expression of full-length calreticulin and the N + P domain of the protein. Expression of the P + C domain of calreticulin does not affect bradykinin-induced Ca2+ release but restores the ER Ca2+ storage capacity. Our results indicate that calreticulin may play a role in folding of the bradykinin receptor, which affects its ability to initiate InsP3-dependent Ca2+ release in calreticulin-deficient cells. We concluded that the C domain of calreticulin plays a role in Ca2+ storage and that the N domain may participate in its chaperone functions.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Bradicinina/farmacologia , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , ATPases Transportadoras de Cálcio/metabolismo , Calreticulina , Linhagem Celular , Inibidores Enzimáticos/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Citometria de Fluxo , Homeostase , Immunoblotting , Receptores de Inositol 1,4,5-Trifosfato , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Receptores da Bradicinina/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Ribonucleoproteínas/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático , Tapsigargina/farmacologia , Transfecção
14.
Phys Rev Lett ; 86(24): 5409-12, 2001 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-11415263

RESUMO

We have produced an interacting quantum degenerate Fermi gas of atoms composed of two spin states of magnetically trapped 40K. The relative Fermi energies are adjusted by controlling the population in each spin state. Thermodynamic measurements reveal a resulting imbalance in the mean energy per particle between the two species, which is a factor of 1.4 at our lowest temperature. This imbalance of energy comes from a suppression of collisions between atoms in the gas due to the Pauli exclusion principle. Through measurements of the thermal relaxation rate we have directly observed this Pauli blocking as a factor of 2 reduction in the effective collision cross section in the quantum degenerate regime.

15.
Prostate Cancer Prostatic Dis ; 4(1): 63-66, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12497064

RESUMO

With the increasing incidence of prostatic intraepithelial neoplasia being found at the time of prostate biopsy and the association of prostatic intraepithelial neoplasia to coexisting prostate cancer and/or the future development of prostate cancer, patient compliance in following post-biopsy follow-up instructions for re-biopsy is becoming more significant in the detection of prostate cancer at an earlier and, therefore, potentially curable stage. During a 3-y period, we reviewed the charts of 130 patients who received an initial diagnosis of prostatic intraepithelial neoplasia after undergoing transrectal ultrasound of the prostate with biopsy. It is our policy to inform the patient of their diagnosis of prostatic intraepithelial neoplasia at the time of the initial biopsy and to recommend a repeat biopsy in 6-12 months. Patients are informed of the diagnosis of prostatic intraepithelial neoplasia verbally and in writing. In addition, a letter is sent to their referring physician with the re-biopsy recommendation. Thirty-nine of 130 patients (30%) were seen for re-biopsy within the specified time. An additional 36 patients (27.69%) were re-biopsied between 12 and 18 months after the initial diagnosis of prostatic intraepithelial neoplasia. An additional 11 patients (7%) were re-biopsied more than 18 months after their initial diagnosis. Forty-four patients failed to return for re-biopsy. Overall, patient follow-up within the desired protocol was poor and must be improved upon to prevent any delays in the diagnosis of prostate cancer. Prostate Cancer and Prostatic Diseases (2001) 4, 63-66

16.
Magy Seb ; 54 Suppl: 5-9, 2001 Dec.
Artigo em Húngaro | MEDLINE | ID: mdl-11816148

RESUMO

OBJECTIVES: The eversion endarterectomy of the internal carotid artery was introduced in Hungary in 1991. The aim of this study was to define the long-term restenosis rate of this new method. MATERIALS AND METHODS: Between 1991 and 1993, 171 operations were performed by one surgeon on 151 patients: 109 patients had enough compliance to take part in long-term follow-up, which included annual physical and ultrasound (Ultramark 9) investigations. Restenosis rate and plaque morphology was defined. Survival and patency rates were calculated by life-table method. RESULTS: The perioperative combined stroke morbidity and mortality rate was 0.8%. The 5-year patient survival rate was 85%, the recurrent stenosis free rate was 88%/5 years, and 9% of the patients had restenosis greater than 70% in this period. The plaque morphology showed calcification in 1 case. Two patients needed 3 reoperations (2.4%). Plaque histology showed myointimal hyperplasia in every 3 cases. CONCLUSIONS: Comparing our results to the literature (2-34% restenosis rate) it seems to be acceptable and encouraging for the future. The ultrasound and histological findings suggest that arteriosclerosis does not play significant role in development of restenosis after the eversion method.


Assuntos
Artéria Carótida Interna/cirurgia , Estenose das Carótidas/cirurgia , Endarterectomia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Artéria Carótida Interna/patologia , Estenose das Carótidas/patologia , Feminino , Seguimentos , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Recidiva , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Túnica Íntima/patologia
17.
Acta Pharm Hung ; 70(3-6): 223-30, 2000.
Artigo em Húngaro | MEDLINE | ID: mdl-11379029

RESUMO

The paper gives a brief overview from the complexation of metals by different ligands in the natural environment and it shows by several examples how transport, biological availability and environmental influences of the metals are attached by these processes.


Assuntos
Ligantes , Metais/química , Metais/farmacocinética , Disponibilidade Biológica , Transporte Biológico , Meio Ambiente
18.
Cells Tissues Organs ; 164(4): 227-36, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10436331

RESUMO

This study reports an anatomical investigation of the angular branch of the thoracodorsal artery, which can be used in reconstructive surgery to serve as a pedicle for gaining osseous material from the scapula. The study was performed on 135 samples and topography and morphometry of the vessel were investigated. It was found that this artery has five main types of origin. It courses in the fascial gliding layer between the serratus muscle, and the teres major and subscapular muscle to the inferior angle of the scapula. There it provides the bone with blood through periostal branches as part of the arterial rete on the costal and dorsal side of the scapula. The mean length of the angular branch and the thoracodorsal artery together was 148 mm, and when also adding the subscapular artery the overall length became 167 mm. It was found that the length of a pedicle consisting of the angular branch and the thoracodorsal artery is determined by the difference in origin of the vessels with minor influences of the body size. The internal diameters of unfilled fixated vessels measured 3.06 mm for the subscapular, 1.77 mm for the circumflex scapular, 1.30 mm for the thoracodorsal and 0. 64 mm for the angular branch. The exact knowledge of the microanatomy in this area is necessary to be able to use the osseous free flap more selectively and have less traumatization in the donor area.


Assuntos
Escápula/irrigação sanguínea , Idoso , Idoso de 80 Anos ou mais , Artérias/anatomia & histologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão
19.
Anat Rec ; 244(1): 59-69, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8838424

RESUMO

BACKGROUND: Glutathione S-transferases (GSTs) are a family of isozymes that catalyze the conjugation of glutathione to various electrophilic compounds. Recently, the Yf subunit of GST-P, found in high concentrations in the epididymis, has been immunolocalized within epithelial principal and basal cells of this tissue. In order to determine which factor(s) were involved in the regulation of expression of this protein, adult rats were orchidectomized and treated with or without testosterone implants, ligated or hypophysectomized. METHODS: The epididymides were fixed by perfusion with Bouin's fixative and examined with an anti-Yf antibody using light microscope immunocytochemistry. RESULTS: In normal untreated animals, principal cells were reactive in the distal initial segment, intermediate zone and caput epididymidis, but unreactive in all other epididymal regions. Ligation of the efferent ducts up to day 14 had no effect on expression of the Yf protein in principal cells of any region. The staining pattern was comparable to that observed in normal untreated animals suggesting that luminally derived testicular factors were not involved in regulation of Yf expression. Following orchidectomy, principal cells became unreactive by day 14 in all epididymal regions. However, administration of testosterone to orchidectomized animals prevented the loss of reactivity seen in principal cells of the distal initial segment, intermediate zone, and caput epididymidis, suggesting that expression of the Yf protein in principal cells of these regions is regulated by circulating testosterone. In contrast, basal cells after each experimental treatment including hypophysectomy maintained the exact staining pattern observed in normal untreated animals, i.e., they were intensely reactive in the proximal initial segment, distal caput, corpus, and proximal cauda regions, suggesting that expression of the Yf protein in these cells does not require factors derived from the testis or pituitary gland. However, a change in the shape and arrangement of basal cells was noted following each treatment. These cells transformed from flattened hemispherical cells showing thin elongated lateral processes to large bulbous, dome-shape cells closely packed together and showing only a few short lateral processes. CONCLUSIONS: In basal cells, expression of the Yf protein is not regulated by testicular or pituitary factors, whereas expression in principal cells is regulated by circulating testosterone. Due to the decrease in size of the epididymal tubules after each treatment, it is postulated that the shape and arrangement of basal cells in normal untreated animals are governed in part by the volume and pressure exerted upon the tubules by luminal fluids and spermatozoa derived from the testis.


Assuntos
Epididimo/citologia , Epididimo/metabolismo , Glutationa Transferase/biossíntese , Hipofisectomia , Orquiectomia , Animais , Epididimo/química , Glutationa Transferase/efeitos dos fármacos , Imuno-Histoquímica , Ligadura , Masculino , Ratos , Ratos Sprague-Dawley
20.
Microsc Res Tech ; 30(1): 1-23, 1995 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-7711317

RESUMO

Glutathione S-transferases (GSTs) are dimeric proteins that come from a multigene family. They can be grouped into five classes (alpha, mu, pi, sigma, theta) based on the degree of amino acid homology of their subunits. These GST isozymes are able to catalyze the conjugation of glutathione with a wide variety of electrophiles, thereby protecting important cellular constituents from electrophilic attack. In the present study, the distribution of the Ya and Yc subunits from the alpha family, as well as the Yb1 and Yb2 subunits from the mu gene family was examined using immunocytochemistry in the adult rat testis and epididymis. The results of these four GST subunits were also compared with two other subunits, the Yf and Yo proteins, which have already been investigated in our laboratory [Veri et al. (1993), J. Androl., 14:23-44; Veri et al. (in press), J. Androl.]. In the testis, Leydig cells were intensely stained for all six subunits. Within the seminiferous epithelium, Sertoli cells were reactive only for antibodies raised against the Ya, Yb1 and Yf subunits. Among germ cells, all spermatogonia, spermatocytes and step 1-15 spermatids were virtually unreactive for each of the six GSTs. However, moderate to intense staining was seen over steps 16-19 spermatids with the anti-Yo and anti-Ya antibodies, and intense staining over step 19 spermatids with the anti-Yb1 and anti-Yb2 antibodies. In the rete testis, Yf, Yo, Yb1, and Yb2 subunits were intensely reactive over the epithelial cells with weak staining for Yc and no staining for Ya antibodies. Interestingly, in the efferent ducts the Yc, Yb1, and Yf proteins were intensely reactive over ciliated cells, whereas only the Yc protein was intensely reactive over nonciliated cells. In the epididymis, immunoreactivity varied among the principal and basal cells of a given epididymal region for each GST antibody. In the case of principal cells, several of the GSTs showed a similar immunostaining pattern along the tubule. Although not identical in intensity of reaction, the Yc, Yb1, Ya and Yo proteins showed an increase in staining intensity from the proximal to distal segments of the epididymis. In contrast, the Yb2 protein was intensely expressed only in the distal caput with weak levels throughout the rest of the epididymis. The Yf reactivity was strongest from the distal initial segment to the distal caput and unreactive in the corpus and proximal cauda epididymidis.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Epididimo/enzimologia , Glutationa Transferase/análise , Técnicas Imunoenzimáticas , Isoenzimas/análise , Testículo/enzimologia , Animais , Epididimo/citologia , Masculino , Ratos , Ratos Sprague-Dawley , Testículo/citologia
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