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1.
Nano Lett ; 19(9): 5938-5948, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31385709

RESUMO

Several of the key issues of planar (Al,Ga)N-based deep-ultraviolet light-emitting diodes could potentially be overcome by utilizing nanowire heterostructures, exhibiting high structural perfection, and improved light extraction. Here, we study the spontaneous emission of GaN/(Al,Ga)N nanowire ensembles grown on Si(111) by plasma-assisted molecular beam epitaxy. The nanowires contain single GaN quantum disks embedded in long (Al,Ga)N nanowire segments essential for efficient light extraction. These quantum disks are found to exhibit intense light emission at unexpectedly high energies, namely, significantly above the GaN bandgap, and almost independent of the disk thickness. An in-depth investigation of the actual structure and composition of the nanowires reveals a spontaneously formed Al gradient both along and across the nanowire, resulting in a complex core/shell structure with an Al-deficient core and an Al-rich shell with continuously varying Al content along the entire length of the (Al,Ga)N segment. This compositional change along the nanowire growth axis induces a polarization doping of the shell that results in a degenerate electron gas in the disk, thus screening the built-in electric fields. The high carrier density not only results in the unexpectedly high transition energies but also in radiative lifetimes depending only weakly on temperature, leading to a comparatively high internal quantum efficiency of the GaN quantum disks up to room temperature.

3.
Internist (Berl) ; 56(10): 1114-23, 2015 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-26384500

RESUMO

A low birth rate in addition to an increasing life expectancy within the context of an aging population characterize the current demographic situation in Germany. Cancer is primarily a disease of old age and the frequency increases with an expanding older population. In 2013, cancer was the second most common cause of death in Germany. With the aid of screening examinations cancer should be detected in the early stages so that suitable therapeutic measures can be initiated. In Germany, screening is currently offered for breast, cervical, colorectal, skin and prostate cancer and is covered by the statutory health insurance. Mammography screening is the only organized screening program in Germany. Eligible women are regularly invited to attend this program, which is not the case for the other types of cancer screening. In accordance with the Cancer Screening and Registry Act (KFRG) of 2013, colorectal and cervical cancer screening will also be implemented as organized screening programs in the future. As is the case in the mammography screening program, those eligible to participate will receive an invitation letter and the new programs are to be continually monitored, documented and evaluated.


Assuntos
Detecção Precoce de Câncer/métodos , Mamografia/estatística & dados numéricos , Neoplasias/diagnóstico , Neoplasias/prevenção & controle , Detecção Precoce de Câncer/estatística & dados numéricos , Diagnóstico Precoce , Medicina Baseada em Evidências , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Neoplasias/epidemiologia , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade
4.
Strahlenther Onkol ; 190(3): 250-5, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24322993

RESUMO

PURPOSE: In this study, the acute toxicity and long-term outcome of a hyperfractionated accelerated chemoradiation regimen with cisplatin/5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinomas of head and neck were evaluated. PATIENTS AND METHODS: From 2000-2002, 38 patients with stage III (5.3 %) and stage IV (94.7 %) head and neck cancer were enrolled in a phase II study. Patients received hyperfractionated-accelerated radiotherapy with 72 Gy in 15 fractions of 2 Gy followed by 1.4 Gy twice daily with concurrent, continuous infusion 5-FU of 600 mg/m(2) on days 1-5 and 6 cycles of weekly cisplatin (30 mg/m(2)). Acute toxicities (CTCAEv2.0), locoregional control (LRC), metastases-free (MFS), and overall survival (OS) were analyzed and exploratively compared with the ARO 95-06 trial. RESULTS: Median follow-up was 11.4 years (95 % CI 8.6-14.2) and mean dose 71.6 Gy. Of the patients, 82 % had 6 (n = 15) or 5 (n = 16) cycles of cisplatin, 5 and 2 patients received 4 and 3 cycles, respectively. Grade 3 anemia, leukopenia, and thrombocytopenia were observed in 15.8, 15.8, and 2.6 %, respectively. Grade 3 mucositis in 50 %, grade 3 and 4 dysphagia in 55 and 13 %. The 2-, 5-, and 10-year LRC was 65, 53.6, and 48.2 %, the MFS was 77.5, 66.7, and 57.2 % and the OS 59.6, 29.2, and 15 %, respectively. CONCLUSION: Chemoradiation with 5-FU and cisplatin seems feasible and superior in terms of LRC and OS to the ARO 95-06C-HART arm at 2 years. However, this did not persist at the 5- and 10-year follow-ups.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia , Fracionamento da Dose de Radiação , Neoplasias Otorrinolaringológicas/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Otorrinolaringológicas/mortalidade , Neoplasias Otorrinolaringológicas/patologia , Projetos Piloto , Estudos Prospectivos , Lesões por Radiação/etiologia
5.
Gesundheitswesen ; 75(12): 819-21, 2013 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-23468215

RESUMO

On comparing surgical and conservative approaches in therapy for obesity it is accepted that there is a more rapid decline in body weight after surgery than by conservative measures. In contrast to widespread convictions, it has been shown that even in extreme obesity (BMI>60 kg/m²) both a meaningful and a long-lasting reduction of body weight is possible by conservative approach. There is an increasing body of evidence that bariatric surgery, especially malabsorptive and combined forms, causes endocrine disturbances and both vitamin and micronutrient deficiencies. Furthermore, alterations in drug pharmacokinetics are possible. Even bariatric surgeons have stated that surgery neither removes the chronic disease obesity nor is its final therapy.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/métodos , Dietoterapia/métodos , Distúrbios Nutricionais/etiologia , Obesidade/psicologia , Obesidade/terapia , Fármacos Antiobesidade/efeitos adversos , Dietoterapia/efeitos adversos , Medicina Baseada em Evidências , Humanos , Distúrbios Nutricionais/prevenção & controle , Resultado do Tratamento
6.
MMW Fortschr Med ; 155 Suppl 1: 6-17, 2013 Mar 21.
Artigo em Alemão | MEDLINE | ID: mdl-23678666

RESUMO

In recent years the number of bariatric surgery has markedly increased in industrial nations. Surgery provides a more rapid decrease of body weight than conservative approach. However a long term conservative follow up therapy is mandatory to stabilize reduced weight. Due to increasing knowledge from long term follow up of surgically treated obese patients there is a growing body of evidence that frequently there is necessity of reoperations and of substitution both of trace elementsand of minerals or vitamins due to their hampered enteral resorption. Additionally therapy of surgery induced endocrine alterations not seldom is necessary.These insights are of outstanding importance because meanwhile an enlargement of the indications for bariatric surgery as a therapeutic option for metabolic disorders is being discussed. This review refers to the recent internationally published papers concerning consequences of bariatric surgery.


Assuntos
Cirurgia Bariátrica/métodos , Complicações Pós-Operatórias/etiologia , Assistência ao Convalescente/métodos , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/mortalidade , Índice de Massa Corporal , Comportamento Cooperativo , Deficiências Nutricionais/etiologia , Deficiências Nutricionais/mortalidade , Deficiências Nutricionais/terapia , Dieta Redutora , Exercício Físico , Seguimentos , Hormônios Gastrointestinais/fisiologia , Indicadores Básicos de Saúde , Humanos , Comunicação Interdisciplinar , Absorção Intestinal/fisiologia , Equipe de Assistência ao Paciente , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/cirurgia , Complicações Pós-Operatórias/terapia , Reoperação , Redução de Peso/fisiologia
7.
Nanotechnology ; 23(46): 465301, 2012 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-23092897

RESUMO

Light emitting diodes (LEDs) have been fabricated using ensembles of free-standing (In, Ga)N/GaN nanowires (NWs) grown on Si substrates in the self-induced growth mode by molecular beam epitaxy. Electron-beam-induced current analysis, cathodoluminescence as well as biased µ-photoluminescence spectroscopy, transmission electron microscopy, and electrical measurements indicate that the electroluminescence of such LEDs is governed by the differences in the individual current densities of the single-NW LEDs operated in parallel, i.e. by the inhomogeneity of the current path in the ensemble LED. In addition, the optoelectronic characterization leads to the conclusion that these NWs exhibit N-polarity and that the (In, Ga)N quantum well states in the NWs are subject to a non-vanishing quantum confined Stark effect.

8.
Gesundheitswesen ; 74(2): 71-8, 2012 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-21225548

RESUMO

GOAL: Using data from a sample of breast cancer patients it was examined whether the utilisation of inpatient rehabilitation after breast cancer surgery within one year of primary therapy is unequally distributed. Furthermore, it was considered which reasons are associated with the omission of rehabilitation. MATERIAL AND METHODS: Subjects were women after primary manifestation of breast cancer (stages: T(1)-T(3); N(0)-N(2); M(0)) aged 25-70 years. The data were collected as part of an ongoing prospective study on the role of social factors in the long-term course of breast cancer. Patients were interviewed immediately after primary surgery and a second time 1 year later. Interviews were performed by specially trained interviewers using semi-structured schedules. 3 gynaecological clinics in Hannover were involved. Logistic regression models were used for performing the main analyses. RESULTS: The data of 238 patients were used; 150 (63.3%) of them went to inpatient rehabilitation. Women with 12/13 years of school education were less likely to go to a rehabilitation clinic than women with lower qualifications; no social gradients in terms of occupational position emerged. A strong predictor for rehabilitation was chemotherapy, and in employed women radiotherapy was associated with lower utilisation. The reasons for not going to rehabilitation appear to be rather personal. They were motivated by patients' avoidance of being faced with cancer, and by the desire to take up the every day life that was interrupted by disease. These reasons are not socially patterned. CONCLUSION: We found no evidence for social barriers for utilising inpatient rehabilitation, but rather that medical and particularly individual reasons apply.


Assuntos
Neoplasias da Mama/reabilitação , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Centros de Reabilitação/estatística & dados numéricos , Fatores Socioeconômicos , Adulto , Idoso , Neoplasias da Mama/patologia , Neoplasias da Mama/psicologia , Terapia Combinada/psicologia , Terapia Combinada/estatística & dados numéricos , Negação em Psicologia , Escolaridade , Feminino , Alemanha , Humanos , Individualidade , Pessoa de Meia-Idade , Motivação , Estadiamento de Neoplasias , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Estudos Prospectivos , Análise de Regressão , Revisão da Utilização de Recursos de Saúde/estatística & dados numéricos
9.
Arch Orthop Trauma Surg ; 131(8): 1145-51, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21359871

RESUMO

PURPOSE: Several studies have investigated the influence of different growth factors on hyaline cartilage regeneration. In a rabbit model, hepatocyte growth factor (HGF) was proven to increase the amount of hyaline-like chondrocytes in a mixed fibro-cartilaginous regenerate of small defects. The aim of the current study was to evaluate whether intra-articular administration of HGF influences the ingrowth of osteochondral grafts in a sheep model. TYPE OF STUDY: Animal experiment. METHODS: Both knee joints of eight sheep were opened surgically and osteochondral grafts were harvested and simultaneously transplanted to the opposite condyle of the same joint. The sheep were divided into two groups of four sheep, resulting in 16 grafts per group. In one group, HGF was administered by bilateral intra-articular injections given three times a week for 4 weeks. The control group received isotonic sodium chloride injections. The animals were killed after 3 months. RESULTS: Histological evaluation showed a complete ingrowth of the osseous part of the osteochondral grafts. A healing or ingrowth at the level of the cartilage could not be observed. Histological evaluation of the transplanted grafts according to the modified Mankin score revealed less degeneration in the cartilage of the HGF group, as compared to the control group. In the HGF group, less cloning of chondrocytes and less irregularities of the articular surface were observed. Importantly, no deleterious effects, such as osteophyte formation, cartilage thickening or synovial proliferation, were found. CONCLUSION: HGF positively influenced the cellularity of the transplanted osteochondral graft, but could not diminish the fissures in the marginal zone of the grafts. CLINICAL RELEVANCE: Marginal zone fissures and degeneration in the absence of HGF may undermine long-term results of autologous osteochondral grafts.


Assuntos
Cartilagem/transplante , Condrócitos/efeitos dos fármacos , Sobrevivência de Enxerto/efeitos dos fármacos , Fator de Crescimento de Hepatócito/farmacologia , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Animais , Cartilagem/efeitos dos fármacos , Cartilagem Articular/lesões , Cartilagem Articular/cirurgia , Esquema de Medicação , Fator de Crescimento de Hepatócito/administração & dosagem , Injeções Intra-Articulares , Masculino , Ovinos , Cicatrização/efeitos dos fármacos
10.
Gesundheitswesen ; 70(11): 644-8, 2008 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-19039721

RESUMO

BACKGROUND: In the German federal state of Lower-Saxony the districts are responsible for conducting school entry health examinations. There exist two different standard protocols for diagnosis and documentation, denoted as Weser-Ems (WE) and SOPHIA. In order to analyse and improve the comparability between these two protocols, a working group was established in 2006. One of the objectives was to adjust the protocols in such a way that in the future the collected data will allow for joint health reporting. METHODS: Each variable was discussed individually by the working group, and if diagnosis or documentation differed between the two protocols, specific modifications were proposed. For certain variables external expert opinions were obtained. For those variables that had to be revised quite generally, specific sub-working groups were established. As prerequisite for implementation, the recommendations of the working group had to be accepted by the user groups through majority votes. RESULTS: Of 88 (WE) or, respectively, 66 (SOPHIA) variables, 39 (WE) or, respectively, 34 variables initially fulfilled the requirements for a joint analysis. As a result of the working group, for more than 20 other variables the requirements for a joint analysis could be achieved. As soon as the sub-working groups have completed their work, also the issues of physical coordination, cognitive abilities and psychological health will be available for joint analysis. DISCUSSION: The synchronisation of school entry health examinations in Lower-Saxony is an example of how different protocols of diagnosis and documentation can be adapted to each other to enable joint data analysis without loosing their individual characteristics.


Assuntos
Documentação/estatística & dados numéricos , Notificação de Abuso , Sistemas Computadorizados de Registros Médicos/organização & administração , Exame Físico/métodos , Exame Físico/estatística & dados numéricos , Serviços de Saúde Escolar/organização & administração , Instituições Acadêmicas/estatística & dados numéricos , Documentação/métodos , Alemanha , Sistemas Computadorizados de Registros Médicos/estatística & dados numéricos
12.
J Phys Condens Matter ; 19(17): 176005, 2007 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-21690942

RESUMO

The Al compositional distribution of AlGaN is investigated by cathodoluminescence (CL). Monochromatic CL images and CL spectra reveal a lateral Al compositional inhomogeneity, which corresponds to surface hexagonal patterns. Cross-sectional CL images show a relatively uniform Al compositional distribution in the growth direction, indicating columnar growth mode of AlGaN films. In addition, a thin AlGaN layer with lower Al composition is grown on top of the buffer AlN layer near the bottom of the AlGaN epilayer because of the larger lateral mobility of Ga adatoms on the growth surface and their accumulation at the grain boundaries.

13.
Cancer Res ; 52(11): 3220-3, 1992 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-1317262

RESUMO

Mutations in the p53 gene are frequent genetic alterations in human hepatocellular carcinomas. We have examined 13 cases of human hepatocellular carcinomas from Germany for the presence of p53 aberrations in exons 4 to 8 of the gene by single-strand conformation polymorphism and restriction fragment-length polymorphism analyses and by sequencing of polymerase chain reaction products. Single base substitutions occurred in two human hepatocellular carcinomas: a C:G----T:A transition at a CpG site in codon 257, and a T:A----A:T transversion at codon 273. One of these point-mutated tumors and two additional tumors without point mutations demonstrated a loss of one p53 allele. None of the tumors was mutated in codons 12 or 61 of the c-Ha-ras gene.


Assuntos
Carcinoma Hepatocelular/genética , Genes p53 , Neoplasias Hepáticas/genética , Mutação , Adulto , Idoso , Sequência de Bases , Carcinoma Hepatocelular/patologia , Deleção Cromossômica , Éxons , Feminino , Alemanha , Humanos , Lactente , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Reação em Cadeia da Polimerase
14.
J Clin Oncol ; 16(12): 3810-21, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9850026

RESUMO

PURPOSE: The HD9 trial aims to evaluate whether moderate dose escalation and/or acceleration of standard polychemotherapy is beneficial for advanced-stage Hodgkin's disease (HD). Two variants of a novel bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) scheme (standard and escalated dose) are compared with cyclophosphamide, vincristine, procarbazine, and prednisone (COPP)/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). PATIENTS AND METHODS: The randomized, three-arm trial recruited patients in stages IIB and IIIA with risk factors and stages IIIB and IV. BEACOPP in baseline dose contains all drug dosages of COPP/ABVD (except vincristine and procarbazine) rearranged in a shorter, 3-week cycle. Escalated BEACOPP uses higher doses of cyclophosphamide, doxorubicin, and etoposide with granulocyte colony-stimulating factor (G-CSF) support. After eight chemotherapy cycles, initial bulky and residual disease is irradiated. The trial is monitored and analyzed by means of a sequential strategy. RESULTS: An interim analysis with 505 assessable patients and a median follow-up of 23 months showed a significant inferiority (according to sequential monitoring strategy) of the COPP/ABVD regimen in progression rate and freedom from treatment failure (FFTF) compared with the pooled results of both BEACOPP variants. The 24-month FFTF rate was 75% for COPP/ABVD and 84% for BEACOPP pooled (P = .034). There was 12% progressive disease with COPP/ABVD and 6% with BEACOPP pooled. Differences in survival were not significant in sequential analysis. The acute toxicity of baseline BEACOPP resembled that of COPP/ABVD; escalated BEACOPP showed increased but manageable hematologic toxicity. CONCLUSION: Combined with local irradiation, BEACOPP in one or both variants shows superior disease control compared with COPP/ABVD, with acceptable acute toxicity. Further follow-up is required to assess the effect of dosage and the effect on survival and late toxicities.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doença de Hodgkin/tratamento farmacológico , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Áustria , Bleomicina/administração & dosagem , Ciclofosfamida/administração & dosagem , República Tcheca , Dacarbazina/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Alemanha , Doença de Hodgkin/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Procarbazina/administração & dosagem , Radioterapia Adjuvante , Suíça , Resultado do Tratamento , Vimblastina/administração & dosagem , Vincristina/administração & dosagem
15.
Br J Pharmacol ; 75(3): 549-52, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6121597

RESUMO

1 Noradrenaline and Sgd 101/75 (4(2-imidazoline-amino)-2-methylindazol-chlorhydrate) acted as full agonists in contracting the rat anococcygeus. 2 Very low concentrations of phenoxybenzamine (0.3 nM for 2-30 min) reduced preferentially the effects of Sgd 101/75. Preparations made insensitive to Sgd 101/75 by phenoxybenzamine still contracted to noradrenaline, this contraction occurring in the presence of high concentrations (400 microM) of Sgd 101/75. 3 It is concluded therefore that the alpha 1-adrenoceptor in this preparation is not a homogeneous entity and must be subdivided into at least two subtypes.


Assuntos
Agonistas alfa-Adrenérgicos , Clonidina/análogos & derivados , Músculo Liso/efeitos dos fármacos , Fenoxibenzamina , Receptores Adrenérgicos alfa/classificação , Receptores Adrenérgicos/classificação , Animais , Técnicas In Vitro , Contração Muscular/efeitos dos fármacos , Norepinefrina/farmacologia , Ratos , Ratos Endogâmicos
16.
Radiother Oncol ; 50(3): 325-36, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10392819

RESUMO

PURPOSE: A computer controlled micro multi-leaf collimator, m3 mMLC, has been commissioned for conformal, fixed-field radiosurgery applications. Measurements were made to characterise the basic dosimetric properties of the m3, such as leaf transmission, leakage and beam penumbra. In addition, the geometric and dosimetric accuracy of the m3 was verified when used in conjunction with a BrainSCAN v3.5 stereotactic planning system. MATERIALS AND METHODS: The m3 was detachably mounted to a Varian Clinac 2100C accelerator delivering 6 MV X-rays. Leaf transmission, leakage, penumbra and multiple, conformal fixed field dose distributions were measured using calibrated film in solid water. Beam data were collected using a diamond detector in a scanning water tank and planned dose distributions were verified using LiF TLDs and film. A small, shaped phantom was also constructed to confirm field shaping accuracy using portal images. RESULTS: Mean transmission through the closed multi-leaves was 1.9 +/- 0.1% and leakage between leaves was 2.8 +/- 0.15%. Between opposing leaves abutting along the central beam-axis transmission was approximately 15 +/- 3%, but was reduced to a mean of 4.5 +/- 0.6% by moving the abutmen position 4.5 cm off-axis. Beam penumbrae were effectively constant as a function of increasing square field size and asymmetric fields and was seen to vary non-linearly when shaped to diagonal, straight edges. TMR, OAR and relative output beam data measurements of circular m3 fields were comparable to conventional, circular stereotactic collimators. Multiple, conformal field dose distributions were calculated with good spatial and dosimetric accuracy, with the planned 90% isodose curves agreeing with measurements to within 1-2 mm and to +/- 3% at isocentre. Portal films agreed with planned beams eye-view field shaping to within 1 mm. CONCLUSIONS: The m3 micro multi-leaf collimator is a stable, high precision field-shaping device suitable for small-field, radiosurgery applications. Dose distributions can be accurately calculated by a planning system using only a few beam data parameters.


Assuntos
Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Encéfalo/cirurgia , Densitometria , Humanos , Aceleradores de Partículas , Imagens de Fantasmas , Garantia da Qualidade dos Cuidados de Saúde , Radiometria , Radiocirurgia/instrumentação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/instrumentação , Radioterapia Conformacional/instrumentação , Técnicas Estereotáxicas , Dosimetria Termoluminescente/métodos , Filme para Raios X
17.
Int J Oncol ; 10(2): 261-8, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21533371

RESUMO

Foci of altered hepatocytes (FAH) including clear cell foci excessively storing glycogen (focal hepatic glycogenosis) are well known as preneoplastic lesions in animal models of hepatocarcinogenesis induced by chemical, physical or viral agents. The occurrence of similar lesions has been studied in a series of 67 explanted and 2 resected human livers using histological and histochemical approaches. A high incidence of FAH was found in the liver of patients suffering from hepatocellular carcinoma(HCC, 14/14) and liver cirrhosis (21/42). FAH were also detected in one patient each with inborn hepatic glycogenosis type 1a, and cholangiocellular carcinoma. Two patients with focal nodular hyperplasia had FAH-like enzymatic changes within these lesions. No FAH were found in 5 donor livers. FAH excessively storing glycogen including clear and mixed cell foci predominated in most cases with these lesions. The focal hepatic glycogenosis was associated with a significantly increased cell proliferation compared to the extrafocal parenchyma, and with alterations in the activity of various enzymes. In the 175 FAH studied by enzyme histochemistry, two enzymes involved in glycogen breakdown, namely glycogen phosphorylase and glucose-6-phosphatase, showed the most consistent changes, being reduced in 98% and 95%, respectively. In addition, the activities of adenosine triphosphatase and gamma-glutamyltransferase were reduced in 46% and 53% of FAH, respectively. Inconsistent changes were observed in FAH concerning a number of other enzymes. The 14 HCCs investigated histochemically often contained clear cell populations rich in glycogen in well differentiated portions, but were poor in glycogen in moderately and poorly differentiated tumors or tumor components. There were some similarities in the enzyme histochemical pattern of HCC and FAH but also important differences were evident. In contrast to FAH, all HCCs (except one carcinoma of the fibrolamellar type) showed an increase in the activity of the mitochondrial glycerol-3-phosphate dehydrogenase, and 50% of the cases had increased glucose-6-phosphate dehydrogenase activity. The activities of glucose-6-phosphatase and gamma-glutamyltransferase usually showed a reactivation, or even an increase compared to the extrafocal parenchyma, in moderately and poorly differentiated HCCs. Our results indicate that the focal hepatic glycogenosis is a putative preneoplastic lesion in human beings similar to laboratory animals. The focal hepatic glycogenosis appears to be a frequent initial step in neoplastic transformation of hepatocytes, a process associated with a fundamental shift in energy metabolism.

18.
Biomaterials ; 21(6): 551-61, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10701456

RESUMO

Wear debris is considered to be one of the main factors responsible for aseptic loosening of orthopaedic endoprostheses. Whereas the response of cells in the monocytic lineage to foreign materials has been extensively studied, little is known about cells at the bone formation site. In the present study, we examined the hypothesis that the response of osteoblasts to wear debris depends on the chemical composition of the particles. We produced particles from commercially pure titanium (cpTi), Ti-6Al-4V (Ti-A), and cobalt-chrome (CoCr) and obtained ultrahigh molecular weight polyethylene (UHMWPE; GUR 4150) particles from a commercial source. The equivalent circle diameters of the particles were comparable: 1.0 +/- 0.96 microm for UHMWPE; 0.84 +/- 0.12 microm for cpTi; 1.35 +/- 0.09 microm for Ti-A, and 1.21 +/- 0.16 microm for CoCr. Confluent primary human osteoblasts and MG63 osteoblast-like cells were incubated in the presence of particles for 24 h. Harvested cultures were examined by transmission electron microscopy to determine if the cells had phagocytosed the particles. Particles were found intracellularly, primarily in the cytosol, in both the primary osteoblasts and MG63 cells. The chemical composition of the particles inside the cells was confirmed by energy-dispersive X-ray analysis. Morphologically, both cell types had extensive ruffled cell membranes, less-developed endoplasmic reticulum, swollen mitochondria, and vacuolic inclusions compared with untreated cells. CpTi, Ti-A, and CoCr particles were also added to cultures of MG63 cells to assess their effect on proliferation (cell number) and differentiation (alkaline phosphatase activity), and PGE2 production. All three types of particles had effects on the cells. The effect on cell number was dependent on the chemical composition of the particles; Ti-A and CoCr caused a dose-dependent increase, while cpTi particles had a biphasic effect with a maximal increase in cell number observed at the 1:10 dilution. Alkaline phosphatase specific activity was also affected and cpTi was more inhibitory than Ti-A or CoCr. PGE2 production was increased by all particles, but the magnitude of the effect was particle-dependent: CoCr > cpTi > Ti-A. This study demonstrates clearly that human osteoblast-like cells and MG63 cells can phagocytose small UHMWPE, CoCr, Ti-A, and cpTi particles. Phagocytosis of the particles is correlated with changes in morphology, and analysis of MG63 response shows that cell proliferation, differentiation, and prostanoid production are affected. This may have negative effects on bone formation adjacent to an orthopaedic implant and may initiate or contribute to the cellular events that cause aseptic loosening by inhibiting bone formation. The effects on alkaline phosphatase and PGE2 release are dependent on the chemical composition of the particles, suggesting that both the type and concentration of wear debris at an implant site may be important in determining clinical outcome.


Assuntos
Materiais Biocompatíveis/química , Ligas de Cromo/química , Osteoblastos/fisiologia , Fagocitose , Polietilenos/química , Próteses e Implantes , Falha de Prótese , Titânio/química , Idoso , Fosfatase Alcalina/análise , Ligas , Materiais Biocompatíveis/farmacologia , Neoplasias Ósseas/patologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Ligas de Cromo/farmacologia , Citosol/ultraestrutura , Dinoprostona/metabolismo , Humanos , Organelas/ultraestrutura , Osteocalcina/biossíntese , Osteossarcoma/patologia , Fenótipo , Polietilenos/farmacologia , Sialoglicoproteínas/biossíntese , Titânio/farmacologia , Células Tumorais Cultivadas
19.
Ann Thorac Surg ; 69(1): 61-4, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10654487

RESUMO

BACKGROUND: Patients with Werlhof's disease and undergoing a cardiac surgical procedure with cardiopulmonary bypass are at increased risk for bleeding complications. We report the usefulness of preoperative immunoglobulin treatment in selected patients. METHODS: Between May 1995 and July 1998, 10 patients with Werlhof's disease underwent a cardiac surgical procedure with cardiopulmonary bypass in our department. Five patients with mean platelet counts of less than 80x10(9)/L received immunoglobulin therapy preoperatively (group 1). The other 5 patients with mean platelet counts higher than 80x10(9)/L were not so treated (group 2). RESULTS: In group 1, mean platelet count increased from 54x10(9)/L 5 days before operation to 112x10(9)/L after immunoglobulin treatment (p = 0.018) and did not fall to less than 60x10(9)/L postoperatively. Patients in group 1 received 16 units of packed red blood cells and 5 units of platelet concentrate. Patients in group 2 required 24 units of packed red blood cells, 5 units of platelet concentrate, and 23 units of fresh frozen plasma. Only 1 patient (group 2) had a surgical bleeding complication that required reexploration. Mean drainage loss was 1,100 mL in group 1 and 1,210 mL in group 2. CONCLUSIONS: Our data demonstrate that immunoglobulin treatment of patients with Werlhof's disease and mean platelet counts of less than 80x10(9)/L significantly augments platelet counts preoperatively. It may be useful in selected patients.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Imunoglobulinas Intravenosas/uso terapêutico , Púrpura Trombocitopênica Idiopática/terapia , Adulto , Idoso , Perda Sanguínea Cirúrgica/prevenção & controle , Ponte Cardiopulmonar , Doença das Coronárias/cirurgia , Transfusão de Eritrócitos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Plasma , Contagem de Plaquetas , Transfusão de Plaquetas , Hemorragia Pós-Operatória/etiologia , Cuidados Pré-Operatórios , Púrpura Trombocitopênica Idiopática/sangue , Reoperação , Fatores de Risco , Taxa de Sobrevida , Trombocitopenia/sangue
20.
Ann Thorac Surg ; 69(3): 774-7, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10750760

RESUMO

BACKGROUND: Heparin-induced thrombocytopenia type II (HIT II) is a rare but life-threatening side effect of heparin therapy. We describe the perioperative anticoagulative management of patients tested positive for HIT II and requiring implantation of a left ventricular assist device (LVAD). METHODS: We report on 3 patients with a different perioperative anticoagulative management (preoperative, intraoperative, and postoperative anticoagulation with danaparoid-sodium; preoperative anticoagulation with recombinant hirudin, anticoagulation with danaparoid-sodium intraoperatively and postoperatively; preoperative anticoagulation with recombinant hirudin, intraoperative anticoagulation with heparin, and postoperative anticoagulation with danaparoid-sodium) and discuss the difficulties of the treatment. RESULTS: Anticoagulation with alternative drugs such as recombinant hirudin and danaparoid-sodium led to serious and life-threatening bleeding complications as well as to thromboembolic events in the first 2 patients. Therefore the third patient underwent LVAD implantation using heparin for intraoperative anticoagulation to avoid administration of high doses of recombinant hirudin or danaparoid-sodium. Despite very low anti-factor Xa activities, when using danaparoid-sodium postoperatively, the patient suffered from a bleeding complication on the 4th day after LVAD implantation requiring reexploration. CONCLUSIONS: In selected cases (negative heparin-induced platelet aggregation (HIPA) test at the time of LVAD implantation and continuation of postoperative anticoagulation with recombinant hirudin or danaparoid-sodium), heparin may be used for LVAD implantation in HIT II patients to reduce bleeding complications.


Assuntos
Anticoagulantes/uso terapêutico , Sulfatos de Condroitina/uso terapêutico , Dermatan Sulfato/uso terapêutico , Coração Auxiliar , Heparina/efeitos adversos , Heparitina Sulfato/uso terapêutico , Terapia com Hirudina , Trombocitopenia/induzido quimicamente , Adulto , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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