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2.
Sci Rep ; 12(1): 16112, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-36167876

RESUMO

To alleviate anti-cancer treatment burden in advanced breast cancer, patient-clinician communication strategies based on nocebo-effect mechanisms are promising. We assessed distinct/combined effects on psychological outcomes (e.g. anxiety; main outcome) and side-effect expectations of (1) nocebo information about the (non)pharmacological origin of side effects, and (2) clinician-expressed empathy through reassurance of continuing support. Furthermore, we explored whether information and empathy effects on side-effect expectations were mediated by decreased anxiety. In a two-by-two experimental video-vignette design, 160 cancer patients/survivors and healthy women watched one of four videos differing in level of nocebo information (±) and empathy (±). Regression and mediation analysis were used to determine effects of information/empathy and explore anxiety's mediating role. Anxiety was not influenced by empathy or information (Stai-state: p = 0.295; p = 0.390, VAS p = 0.399; p = 0.823). Information improved (specific) side-effect coping expectations (p < 0.01). Empathy improved side-effect intensity expectations (p < 0.01 = specific; p < 0.05 = non-specific/partial) and specific side-effect probability expectations (p < 0.01), and increased satisfaction, trust, and self-efficacy (p < 0.001). No mediating effects were found of anxiety on expectations. Mainly empathy, but also nocebo information improved psychological outcomes and-mainly specific-side-effect expectations. Exploring the power of these communication elements in clinical practice is essential to diminish the anti-cancer treatment burden in advanced breast cancer.


Assuntos
Neoplasias da Mama , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Neoplasias da Mama/tratamento farmacológico , Comunicação , Empatia , Feminino , Humanos , Efeito Nocebo
3.
BMC Health Serv Res ; 19(1): 141, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30819156

RESUMO

BACKGROUND: Generally, a significant portion of healthcare spending consists of out-of-pocket (OOP) expenses. Patients indicate that, in practice, there are often some OOP expenses, incurred when they receive medical care, which are unexpected for them and should have been taken into account when deciding on a course of action. Patients are often reliant on their GP and may, therefore, expect their GP to provide them with information about the costs of treatment options, taking into consideration their individual insurance plan. This also applies to the Netherlands, where OOP expenses increased rapidly over the years. In the current study, we observed the degree to which matters around patients' insurance and OOP expenses are discussed in the Netherlands, using video recordings of consultations between patients and GPs. METHODS: Video recordings were collected from patient-GP consultations in 2015-2016. In 2015, 20 GPs and 392 patients from the eastern part of the Netherlands participated. In 2016, another eight GPs and 102 patients participated, spread throughout the Netherlands. The consultations were coded by three observers using an observation protocol. We achieved an almost perfect inter-rater agreement (Kappa = .82). RESULTS: In total, 475 consultations were analysed. In 9.5% of all the consultations, issues concerning patients' health insurance and OOP expenses were discussed. The reimbursement of the cost of medication was discussed most often and patients' current insurance and co-payments least often. In some consultations, the GP brought up the subject, while in others, the patient initiated the discussion. CONCLUSIONS: While GPs may often be in the position to provide patients with information about treatment alternatives, few patients discuss the financial effects of their referral or prescription with their GP. This result complies with existing literature. Policy makers, GPs and insurers should think about how GPs and patients can be facilitated when considering the OOP expenses of treatment. There are several factors why this study, analysing video recordings of routine GP consultations in the Netherlands, is particularly relevant: Dutch GPs play a gatekeeper function; OOP expenses have increased relatively swiftly; and patients have both the right to decide on their treatment, and to choose a provider.


Assuntos
Financiamento Pessoal , Clínicos Gerais , Gastos em Saúde , Seguro Saúde , Encaminhamento e Consulta , Tomada de Decisões , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Relações Médico-Paciente , Gravação em Vídeo
4.
Mutat Res ; 469(2): 169-79, 2000 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-10984678

RESUMO

Euchromatic and heterochromatic regions are easily distinguished in Chinese hamster sex chromosomes, hence offering the possibility of studying the role of chromatin structure in the induction, processing and persistence of radiation-induced chromosome damage. X-ray (4 Gy)-induced breaks in the euchromatic Xp and in the heterochromatic Xq were analysed immediately and 4h after irradiation by premature chromosome condensation (PCC) in combination with either FISH using chromosome arm-specific probes or Giemsa staining. The study, performed with female Chinese hamster splenocytes, was extended to a 34 h recovery followed by arm-specific FISH in metaphase. A significant over-involvement of the heterochromatic Xq in radiation-induced breakage was observed at all sampling times (p<0.001). However, the heterochromatic state had little effect on the processing of the induced lesions. In a second experiment, the persistence of radiation-induced chromosome aberrations (CAs) involving Xp, Xq and Y chromosome was studied with cultured Chinese hamster male splenocytes sampled 30, 56 and 96 h after irradiation (4 Gy). A higher involvement of the heterochromatic regions (Xq and Y) in radiation-induced CAs was again observed in the first sampling time (p<0.001), suggesting that Chinese hamster heterochromatin could be more radiosensitive than euchromatin. Cells with CAs involving heterochromatin were apparently less persistent than those with lesions involving euchromatin. This observation could be attributable to either the distribution of CA per cell or to the fraction of potentially stable exchanges.


Assuntos
Cromatina/genética , Cromatina/efeitos da radiação , Aberrações Cromossômicas , Heterocromatina/genética , Heterocromatina/efeitos da radiação , Animais , Cricetinae , Cricetulus , Eucromatina , Feminino , Hibridização in Situ Fluorescente , Técnicas In Vitro , Masculino , Baço/citologia , Baço/efeitos da radiação , Fatores de Tempo , Cromossomo X/genética , Cromossomo X/efeitos da radiação
5.
Carcinogenesis ; 20(12): 2267-72, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10590218

RESUMO

Epidemiological studies indicate that increased vegetable consumption reduces the risk of colorectal cancer mortality. In the present study we have investigated the effect of consumption of standard diets supplemented with freeze-dried vegetables (peas, spinach, sprouts and broccoli) and carotenoids (all-trans beta-carotene and palm oil carotenoid extract) on surrogate end-point markers for colorectal cancer in an azoxymethane-induced rat model. Mean aberrant crypt multiplicity was reduced (19%) by the pea-supplemented diet only (P < 0.05). The vegetable-induced effect was more apparent in aberrant crypt foci with higher multiplicity. Intervention with diets supplemented with peas, spinach, sprouts and a mix of all vegetables reduced the number of foci with >2 aberrant crypts/focus by 37, 26, 23 and 26%, respectively (P < 0.05). Even more pronounced effects were observed in foci with >3 aberrant crypts/focus, with reductions of approximately 50% in the pea and spinach intervention groups. All-trans beta-carotene and palm oil-derived carotenoids, supplied at similar doses to those expected in the vegetable diets, inhibited ACM only marginally. Aberrant crypt foci formation in groups fed a sprout-supplemented diet prior to or following azoxymethane treatment was similar, indicating that this effect is due to inhibition of promotion rather than initiation of colorectal carcinogenesis. Vegetable and carotenoid consumption did not affect in situ proliferation of colonic crypt cells, as assessed by semi-automated image analysis of bromodeoxyuridine (BrdU)-positive nuclei. BrdU-negative nuclei of colonic crypt cells were reduced slightly in the combined vegetable groups, as compared with the control (P < 0.05). These data: (i) are in line with epidemiological evidence regarding beneficial effects of vegetable consumption on colorectal carcinogenesis; (ii) indicate that consumption of several types of vegetables inhibits early post-initiation events in colorectal carcinogenesis; (iii) suggest that the vegetable-induced effect is more pronounced in advanced lesions; (iv) indicate that the carotenoid content of the vegetables (alpha- and beta-carotene) contributes only marginally to the vegetable-induced effects.


Assuntos
Azoximetano/toxicidade , Biomarcadores Tumorais , Carotenoides/administração & dosagem , Neoplasias Colorretais/patologia , Alimentos , Verduras , Animais , Peso Corporal , Bromodesoxiuridina , Carcinógenos/toxicidade , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/prevenção & controle , Ratos
6.
Mutat Res ; 404(1-2): 55-65, 1998 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-9729276

RESUMO

In order to study the initial frequencies and define kinetics of the formation of chromosomal exchanges in X-irradiated human lymphocytes, the premature chromosome condensation (PCC) technique was employed in combination with fluorescence in situ hybridization (FISH) with a composite probe for human chromosome 8 and a pan-centromeric probe for the whole genome. Human lymphocytes were X-irradiated (0.5, 1, 2, 3, 4 and 6 Gy), fused with mitotic Chinese hamster ovary (CHO) cells immediately or 1, 3, 6, 12 and 18 h after irradiation. Immediately after irradiation chromosomal breaks, dicentrics and translocations showed a linear dose-response. Unrejoined chromosome breaks were the most frequent types of aberrations (about 85%) observed. About 15% of total aberrations were chromosome exchanges of 65% of these were translocations and 35% were dicentrics. The chromosomal exchanges initially observed were mostly incomplete, with no complex exchanges at doses of 1 and 2 Gy, at higher doses (3-6 Gy) complex exchanges were observed and their frequencies increased with increasing post incubation time. Following different recovery times, repair kinetics of breaks for different doses of irradiation was studied. The shapes of the curves obtained for breaks as well as chromosome exchanges were linear-quadratic. The linear yield component, alpha, is formed entirely in the fast process that can be manifested in the early plateau, while component beta developed slowly in the subsequent hours. The kinetics of breaks rejoining was exponential, almost 50% of breaks rejoined after 1 h and at 18 h about 20% of breaks remained. At low doses of 1 and 2 Gy most of the exchanges were formed immediately and at higher doses, the frequency of exchanges increased with kinetics similar to that observed for the rejoining of breaks. However, the kinetics was different for different doses of irradiation. The frequency of dicentrics increased at doses above 2 Gy following 3 h recovery time, but for the translocations effect was pronounced even at 1 h recovery time. The frequency of incomplete exchanges (i.e., terminal translocations) decreased with post irradiation time and at 18 h was 30-40% less than the frequency obtained immediately after irradiation. The increase in the total translocations as a function of time between irradiation and fusion was due to a rapid increase in complete exchanges (i.e., reciprocal translocations). The frequency of ring chromosomes immediately after irradiation, also increased linearly, however, it was 3-5 times lower than dicentrics and remained almost constant in number for different doses and at different post-irradiation times.


Assuntos
Aberrações Cromossômicas/genética , Cromossomos/efeitos da radiação , Linfócitos/efeitos da radiação , Animais , Células CHO , Fusão Celular/efeitos da radiação , Quebra Cromossômica/genética , Cricetinae , Relação Dose-Resposta à Radiação , Humanos , Hibridização in Situ Fluorescente , Cinética , Translocação Genética/genética , Raios X
7.
Mutat Res ; 372(2): 247-58, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9015143

RESUMO

Fluorescence in situ hybridization (FISH) technique using chromosome specific probes has revolutionized the field of radiation cytogenetics in the last few years. Some of the new insights on the origins of radiation induced chromosome aberrations in human, mouse and Chinese hamster, using FISH are reviewed in this paper.


Assuntos
Aberrações Cromossômicas , Cromossomos/efeitos da radiação , Hibridização in Situ Fluorescente/métodos , Animais , Células CHO , Cricetinae , Cricetulus , Sondas de DNA , Reparo do DNA , Fibroblastos , Fase G1 , Humanos , Linfócitos , Camundongos , Fase de Repouso do Ciclo Celular , Baço/citologia , Vidarabina/farmacologia
8.
Nutr Cancer ; 25(2): 161-72, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8710685

RESUMO

The relationship between dietary fat intake (level and type) and the development of breast cancer in humans is a matter of concern in Western society. A high fat intake is associated with a greater mammary cancer risk in humans and in animal models. Higher intake of polyunsaturated fatty acids in humans shows little or no association with mammary tumor development in epidemiologic surveys. From literature data, it appears that a higher intake of polyunsaturated fatty acids (linoleic acid) is related to an increase in mammary tumorigenesis in animal studies in which chemical carcinogens like dimethylbenz[a]anthracene are used as tumor initiator. Mostly the latency period of these chemically induced models in rather short. In this study, the Bald/c-MMTV (mouse mammary tumor virus) mouse strain was chosen as an animal model: MMTV leads to tumor initiation, and dietary factors influence tumor promotion over a relatively long latency period. The mice were fed diets with two fat concentrations: a high [36% of energy (en%)] or low (16 en%) fat level; fat was isocalorically replaced by carbohydrates (cornstarch). At both dietary fat levels, linoleic acid was given at four levels: 2, 3, 6, and 10 en%. Linoleic acid-rich fat was isocalorically replaced by oleic acid-rich fat. The diets were consumed ad libitum over a lifetime. Animals were euthanized as soon as mammary tumor diameter was > or = 1 cm or when the animals were in a poor clinical condition. The incidence of mammary tumors at 18 months was significantly higher in one group only: 36 en% fat and 2 en% linoleic acid. This group also showed the shortest mean latency period for mammary tumor development. Mean mammary tumor incidence was higher and mean onset time shorter in the four high-fat groups than in the low-fat groups. No (linear) dose-response relationship between dietary linoleic acid concentration and mammary tumor incidence and latency period was observed. This indicates that a higher dietary linoleic acid intake does not increase the incidence or shorten the latency period of breast cancer in the Balb/c-MMTV mouse strain at two different dietary fat levels.


Assuntos
Gorduras na Dieta/administração & dosagem , Ácidos Linoleicos/administração & dosagem , Neoplasias Mamárias Experimentais/etiologia , Vírus do Tumor Mamário do Camundongo , Animais , Peso Corporal , Ingestão de Energia , Feminino , Leucemia Experimental/etiologia , Leucemia Experimental/mortalidade , Ácido Linoleico , Neoplasias Mamárias Experimentais/mortalidade , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C
9.
Int J Cancer ; 63(5): 732-7, 1995 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-7591293

RESUMO

The present 12-month study was carried out to investigate the effects of the aromatase inhibitor aminoglutethimide, alone and in combination with orchiectomy, on pancreatic carcinogenesis in azaserine-treated rats and N-nitrosobis(2-oxopropyl)-amine-treated hamsters. Treatment of the animals started 4 months after the last injection with the carcinogen. They were surgically castrated and/or treated with aminoglutethimide. Aminoglutethimide-treated rats developed less pancreatic tumours than did untreated controls. Multiplicity of (pre-)-neoplastic acinar lesions was lower in orchiectomized rats than in intact rats. Inhibition of pancreatic carcinogenesis was most pronounced in rats that were both orchiectomized and treated with aminoglutethimide. These effects were statistically significant after 8 months, but not after 4 months, of treatment. In hamsters, aminoglutethimide showed an enhancing rather than an inhibitory effect on the formation of ductular pancreatic tumours. Castration appeared to have no effect on the development of N-nitrosobis(2-oxopropyl)amine-induced ductular lesions in the pancreas, either alone, or in combination with aminoglutethimide. The present findings indicate that aminoglutethimide, alone and in combination with surgical castration, might be of value for the treatment of pancreatic acinar tumours, whereas the usefulness of aminoglutethimide for treatment of ductular adenocarcinomas of the pancreas is somewhat doubtful.


Assuntos
Aminoglutetimida/farmacologia , Antineoplásicos/farmacologia , Orquiectomia , Neoplasias Pancreáticas/prevenção & controle , Animais , Azasserina , Peso Corporal/efeitos dos fármacos , Terapia Combinada , Cricetinae , Masculino , Mesocricetus , Tamanho do Órgão/efeitos dos fármacos , Neoplasias Pancreáticas/induzido quimicamente , Ratos , Ratos Wistar
10.
Mutat Res ; 299(3-4): 297-303, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-7683097

RESUMO

Several radiosensitive mutant cell lines of CHO and V79 cells have been studied to explore a possible correlation between radiation induced DNA lesions and chromosomal aberrations. In the xrs mutants which are deficient in DNA double strand break (DSB) repair, there is a correlation between the extent of the defect in repair and the frequencies of radiation induced chromosomal aberrations. In another type of radiosensitive mutant (V-C4), which has no detectable defect in DNA DSB repair, the frequencies of X-ray induced aberrations are high in comparison to wild type V79 cells. However, following treatment with restriction endonucleases or fission neutrons, the frequencies of aberrations are similar to those in V79, indicating that V-C4 cells are defective in repair of X-ray induced lesions other than DSBs. Though DSBs are the most important lesions leading to chromosomal aberrations, in repair deficient mutants, radiation induced lesions other than DSBs can lead to chromosomal aberrations.


Assuntos
Aberrações Cromossômicas , Cromossomos/efeitos da radiação , Dano ao DNA , DNA/efeitos da radiação , Raios Ultravioleta , Animais , Células CHO , Linhagem Celular , Cricetinae , DNA/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Relação Dose-Resposta à Radiação , Pulmão , Nêutrons , Raios X
11.
Mutat Res ; 287(1): 47-56, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-7683384

RESUMO

Using primary Chinese hamster embryonic cells, 10 known or suspected aneugens supplied as a part of the EC 4th Environmental Research and Development Programme were evaluated by the technique described by Dulout and Natarajan (1987). The chemicals included cadmium chloride, chloral hydrate, colchicine, diazepam, econazole, hydroquinone, pyrimethamine, thiabendazole, thimerosal and vincristine. All chemicals except pyrimethamine gave clearly positive effect at most of the doses tested. The ease with which the assay is performed and reproducible results that are obtained with the suspected compounds indicate that this in vitro test using primary embryonic fibroblasts is a promising one for routine screening.


Assuntos
Aneuploidia , Mutagênicos/toxicidade , Animais , Cádmio/toxicidade , Cloreto de Cádmio , Células Cultivadas , Hidrato de Cloral/toxicidade , Cloretos/toxicidade , Colchicina/toxicidade , Cricetinae , Cricetulus , Diazepam/toxicidade , Relação Dose-Resposta a Droga , Econazol/toxicidade , Embrião de Mamíferos , Feminino , Hidroquinonas/toxicidade , Masculino , Mitose/efeitos dos fármacos , Testes de Mutagenicidade/métodos , Pirimetamina/toxicidade , Tiabendazol/toxicidade , Timerosal/toxicidade , Vincristina/toxicidade
12.
Agents Actions ; 39 Spec No: C219-21, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8273574

RESUMO

Cathepsin B and L activity was studied histochemically in arthritic rat ankle joints using specific synthetic substrates in a post coupling method on unfixed and undecalcified cryostat sections of rat ankle joints. Activity was strongly increased in chondrocytes and cells of the inflamed synovium with the development of arthritis induced by the synthetic adjuvant CP20961. Activity reached a maximum 20 days after induction of arthritis and decreased as the rats entered natural remission. Cathepsin B and L were at their highest level when macrophages were present in the joint space, as shown by using monoclonal antibody markers for rat macrophages (ED1 and ED2) in a biotin-avidin immunoperoxidase assay. This suggests that the macrophage infiltrate may have stimulated proteinase production in chondrocytes through cytokine release. The profile of appearance of cysteine proteinases suggests their involvement in the breakdown of cartilage and bone in the arthritic joint.


Assuntos
Artrite Experimental/enzimologia , Cartilagem Articular/enzimologia , Catepsina B/metabolismo , Catepsinas/metabolismo , Cisteína Endopeptidases/metabolismo , Endopeptidases , Membrana Sinovial/enzimologia , Adjuvantes Imunológicos , Animais , Articulação do Tornozelo , Catepsina L , Diaminas/toxicidade , Modelos Animais de Doenças , Macrófagos , Ratos , Ratos Endogâmicos Lew , Linfócitos T
13.
Carcinogenesis ; 13(9): 1525-8, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1394835

RESUMO

Cholecystokinin and bombesin have been shown to promote pancreatic growth and development of azaserine-induced acidophilic atypical acinar cell nodules in rat pancreas after treatment for 16 weeks. Lorglumide, a specific cholecystokinin receptor antagonist, inhibited the stimulating effect of cholecystokinin, but not of bombesin. The present study was carried out to determine effects of cholecystokinin and bombesin, alone and in combination with lorglumide, on pancreatic growth and carcinogenesis after chronic treatment. The animals were killed 8 months after the start of treatment. Growth of the pancreas and the development of acidophilic atypical acinar cell nodules in exocrine pancreas was enhanced significantly by both cholecystokinin and bombesin, but the number of carcinomas was increased only by bombesin. Lorglumide inhibited the effects of cholecystokinin on both pancreatic growth and on the development of acidophilic nodules. The effects of bombesin on pancreatic growth and development of pancreatic lesions, except for adenomas, were not inhibited by lorglumide.


Assuntos
Bombesina/toxicidade , Carcinógenos/toxicidade , Colecistocinina/toxicidade , Neoplasias Pancreáticas/induzido quimicamente , Proglumida/análogos & derivados , Receptores da Colecistocinina/antagonistas & inibidores , Animais , Azasserina , Colecistocinina/antagonistas & inibidores , Colecistocinina/sangue , Sinergismo Farmacológico , Masculino , Proglumida/farmacologia , Ratos , Ratos Wistar
14.
Br J Cancer ; 66(1): 46-50, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1637675

RESUMO

The role of cholecystokinin in dietary fat-promoted pancreatic carcinogenesis was investigated in azaserine-treated rats, using lorglumide, a highly specific cholecystokinin-receptor antagonist. The animals were killed 8 months after the start of treatment. Cholecystokinin, but not dietary unsaturated fat, increased pancreatic weight. Rats treated with cholecystokinin developed more acidophilic atypical acinar cell nodules, adenomas and adenocarcinomas than control animals. Rats maintained on the high-fat diet developed significantly more adenomas and adenocarcinomas than controls given a diet low in unsaturated fat. Lorglumide largely inhibited the enhancing effect of cholecystokinin, but not of dietary fat, on pancreatic carcinogenesis indicating that it is unlikely that the promoting effect of dietary unsaturated fat on pancreatic carcinogenesis is mediated via cholecystokinin.


Assuntos
Azasserina/farmacologia , Colecistocinina/fisiologia , Gorduras na Dieta , Neoplasias Pancreáticas/etiologia , Proglumida/análogos & derivados , Receptores da Colecistocinina/antagonistas & inibidores , Animais , Peso Corporal , Fígado/anatomia & histologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Tamanho do Órgão , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Proglumida/farmacologia , Ratos , Ratos Endogâmicos , Receptores da Colecistocinina/fisiologia
15.
Int J Pancreatol ; 11(2): 137-46, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1535094

RESUMO

The results of a previous 4-mo study in azaserine-treated rats and BOP-treated hamsters indicated that orchiectomy inhibited pancreatic growth and development of putative preneoplastic lesions in the exocrine pancreas of rats but not hamsters. This 12-mo study was carried out to investigate the effects of orchiectomy, alone and in combination with testosterone, and of treatment with cyproterone acetate on pancreatic carcinogenesis in azaserine-treated rats and BOP-treated hamsters. Treatment started 4 mo after injection of the carcinogen. In orchiectomized rats, pancreatic wt was lower than in controls, whereas pancreatic wt of orchiectomized rats treated with testosterone was similar to that of controls. Both orchiectomy and cyproterone acetate caused a decrease in body wt gain and had an inhibitory effect on pancreatic carcinogenesis. Testosterone treatment did not influence the inhibitory effects of orchiectomy on body wt gain and on pancreatic carcinogenesis. In hamsters, neither orchiectomy, alone or in combination with testosterone, nor cyproterone acetate (CA) affected pancreatic growth or pancreatic carcinogenesis. This study indicates that testosterone plays a minor role in the development of pancreatic tumors induced in rats by azaserine but not in that of pancreatic tumors induced in hamsters by BOP.


Assuntos
Ciproterona/análogos & derivados , Orquiectomia , Pâncreas/efeitos dos fármacos , Neoplasias Pancreáticas/etiologia , Testosterona/farmacologia , Animais , Azasserina , Peso Corporal , Cricetinae , Ciproterona/farmacologia , Acetato de Ciproterona , Substâncias de Crescimento/sangue , Masculino , Mesocricetus , Nitrosaminas , Tamanho do Órgão , Ratos , Ratos Endogâmicos , Organismos Livres de Patógenos Específicos
16.
Int J Cancer ; 50(2): 246-51, 1992 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-1730518

RESUMO

The effects of treatment with the somatostatin analogue Sandostatin, separately and in combination with surgical castration, on the development of azaserine-induced lesions in rat pancreas and N-nitrosobis(2-oxopropyl)amine (BOP)-induced lesions in hamster pancreas were investigated. The animals were divided in 4 groups and treated as follows: (a) controls, injected s.c. with saline solution (0.9% NaCl); (b) orchiectomy directly after the last treatment with carcinogen; (c) Sandostatin (SMS 201-995) subcutaneously; (d) orchiectomy followed by treatment with Sandostatin. No significant suppressive effects on plasma EGF or IGF-I concentrations were noted after Sandostatin treatment, but plasma gastrin levels decreased slightly in the rats, not in the hamsters. In rats, Sandostatin treatment enhanced rather than inhibited growth of acidophilic atypical acinar cell nodules. In hamster pancreas, by contrast, Sandostatin inhibited the development of putative pre-neoplastic ductular lesions. There was no interaction between treatment with Sandostatin and surgical castration. It was concluded that Sandostatin, when administered prophylactically, has an inhibitory effect on the growth of putative pre-neoplastic ductular, but not acinar, lesions.


Assuntos
Octreotida/farmacologia , Orquiectomia , Neoplasias Pancreáticas/etiologia , Animais , Azasserina , Carcinógenos , Cricetinae , Interações Medicamentosas , Ingestão de Alimentos/efeitos dos fármacos , Substâncias de Crescimento/sangue , Cobaias , Hormônios/sangue , Masculino , Mesocricetus , Nitrosaminas , Tamanho do Órgão/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Neoplasias Pancreáticas/induzido quimicamente , Neoplasias Pancreáticas/tratamento farmacológico , Ratos , Ratos Endogâmicos
17.
Cancer Lett ; 60(3): 205-11, 1991 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-1756510

RESUMO

Trypsin inhibitors have been shown to promote pancreatic growth as well as the development of pancreatic tumours in rats. The present study was carried out to examine the effects of the synthetic trypsin inhibitor camostate on the growth of the pancreas and on the development of pancreatic preneoplastic and neoplastic lesions in hamsters treated with N-nitrosobis(2-oxopropyl)amine. A specific cholecystokinin-receptor antagonist was administered to determine the role of cholecystokinin in camostate action. The animals were killed 19 weeks after the first injection with N-nitrosobis(2-oxopropyl)amine. Camostate caused an increase in growth of the pancreas and a decrease in the number of (pre)neoplastic ductular pancreatic lesions. Lorglumide (CR-1409) did not influence these effects of camostate. It was concluded that rats and hamsters behave differently with regard to the effect of camostate on pancreatic growth and carcinogenesis.


Assuntos
Carcinógenos/toxicidade , Carcinoma in Situ/induzido quimicamente , Carcinoma/induzido quimicamente , Gabexato/análogos & derivados , Guanidinas/farmacologia , Nitrosaminas/toxicidade , Pâncreas/patologia , Neoplasias Pancreáticas/induzido quimicamente , Inibidores da Tripsina/farmacologia , Animais , Carcinoma/patologia , Carcinoma in Situ/patologia , Colecistocinina/antagonistas & inibidores , Cricetinae , Ésteres , Masculino , Mesocricetus , Pâncreas/efeitos dos fármacos , Neoplasias Pancreáticas/patologia , Proglumida/análogos & derivados , Proglumida/farmacologia , Valores de Referência
18.
Carcinogenesis ; 12(9): 1707-13, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1832592

RESUMO

We studied the effects of hormonal manipulation by orchiectomy, alone or in combination with the aromatase inhibitor aminoglutethimide (AGT), and by luteinizing hormone-releasing hormone agonist (LH-RH-A) (goserelin) treatment on the development of early putative (pre)neoplastic lesions induced in the pancreas of rats and hamsters by azaserine and N-nitrosobis(2-oxopropyl)amine respectively. Treatment of the animals started 1 week after the last injection with carcinogen and continued for 4 months. Orchiectomy caused a significant inhibition of growth of acidophilic atypical acinar cell nodules in the rat model, whereas surgical castration did not show an effect in the hamster model. In rats, but not in hamsters, orchiectomy resulted in a significant decrease in body weight and in absolute, but not relative pancreatic weight. Treatment of the animals with AGT or goserelin did not cause a significant effect on the development of either putative preneoplastic acinar lesions in rat pancreas or early ductular lesions in hamster pancreas. Hamsters showed clearly higher plasma epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) concentrations than rats, while plasma testosterone levels were significantly lower. Plasma EGF and IGF-1 levels decreased with increasing age in both control and treatment groups. Compared to controls there were no clear unequivocal effects of treatment on EGF, IGF-1 and gastrin levels. Plasma testosterone levels decreased by orchiectomy and LH-RH-A treatment. In rats hormone-induced effects on food intake and altered nutritional status might be important with respect to the development of carcinogen-induced preneoplastic pancreatic lesions.


Assuntos
Aminoglutetimida/farmacologia , Orquiectomia , Neoplasias Pancreáticas/fisiopatologia , Lesões Pré-Cancerosas/fisiopatologia , Animais , Azasserina/toxicidade , Peso Corporal/efeitos dos fármacos , Busserrelina/análogos & derivados , Busserrelina/farmacologia , Carcinógenos , Cricetinae , Fator de Crescimento Epidérmico/sangue , Gastrinas/sangue , Gosserrelina , Masculino , Mesocricetus , Nitrosaminas/toxicidade , Tamanho do Órgão/efeitos dos fármacos , Neoplasias Pancreáticas/induzido quimicamente , Lesões Pré-Cancerosas/induzido quimicamente , Ratos , Ratos Endogâmicos , Somatomedinas/análise , Testosterona/sangue
19.
Cancer Lett ; 59(1): 45-50, 1991 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-1878860

RESUMO

Bombesin (BBS) has been shown to promote pancreatic growth as well as the development of pancreatic (pre)neoplasia in rats. The present study was carried out to determine the effects of bombesin on pancreatic growth and on the development of pancreatic (pre)neoplastic lesions in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). Bombesin caused an increase in growth of the pancreas accompanied by a decrease in the number of (pre)neoplastic ductular pancreatic lesions. Lorglumide (CR-1409) did not influence these effects of bombesin. It is concluded that in BOP-treated hamsters the effect of bombesin on the pancreas is not mediated by cholecystokinin (CCK). These data support the existence of species difference between rats and hamsters with regard to the effect of bombesin on pancreatic carcinogenesis.


Assuntos
Bombesina/farmacologia , Nitrosaminas , Neoplasias Pancreáticas/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Colecistocinina/antagonistas & inibidores , Colecistocinina/sangue , Cricetinae , Fígado/anatomia & histologia , Masculino , Mesocricetus , Pâncreas/anatomia & histologia , Pâncreas/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/prevenção & controle , Proglumida/análogos & derivados , Proglumida/farmacologia
20.
Carcinogenesis ; 11(12): 2223-6, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2265473

RESUMO

Cholecystokinin (CCK) has been shown to promote pancreatic growth and azaserine-induced pancreatic carcinogenesis in rats. The present study was carried out to determine effects of CCK on pancreatic growth and carcinogenesis in the N-nitrosobis(2-oxopropyl)amine (BOP) hamster model. One hundred male Syrian golden hamsters were injected s.c. once weekly with 20 mg BOP/kg body wt at 6, 7 and 8 weeks of age, and divided into four groups of 25 animals each, which received one of the following treatments (once daily, 3 days/week for 16 weeks): gelatin; CR-1409, a potent CCK-receptor antagonist; CCK-8, 2.5 micrograms/kg body wt; or CCK-8 in combination with CR-1409 (30 min before CCK treatment). The animals were killed after 19 weeks. The growth of the pancreas but not the incidence of pancreatic (pre)neoplastic lesions was enhanced by CCK-8. CR-1409 did not influence the effect of CCK on pancreatic growth.


Assuntos
Colecistocinina/efeitos adversos , Neoplasias Pancreáticas/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Carcinógenos , Colecistocinina/farmacocinética , Cocarcinogênese , Cricetinae , Masculino , Nitrosaminas , Tamanho do Órgão/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Proglumida/análogos & derivados , Proglumida/farmacologia
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