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1.
Acta Oncol ; 57(7): 965-972, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29419331

RESUMO

BACKGROUND: The optimal primary external beam radiation therapy (EBRT) radiation schedule for malignant epidural spinal cord compression (MSCC) remains to be determined. The ICORG 05-03 trial assessed if a 10 Gy single fraction radiation schedule was not inferior to one with 20 Gray (Gy) in five daily fractions, in terms of functional motor outcome, for the treatment of MSCC in patients not proceeding with surgical decompression. This article reports on two of the secondary endpoints, Quality of life (QoL), assessed according to the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) version 3.0 (EORTC Data Center, Brussels, Belgium) and pain control assessed using a visual analog scale. METHODS: A randomized, parallel group, multicenter phase III trial was conducted by Cancer Trials Ireland (formerly All-Ireland Cooperative Oncology Research Group, ICORG), across five hospital sites in Ireland and Northern Ireland. Patients were randomized to 10 Gy single fraction of EBRT or 20 Gy in five fractions in a 1:1 ratio. Patients with baseline and 5-week follow up QoL data are included in this analysis. FINDINGS: From 2006 to 2014, 112 eligible patients were enrolled for whom 57 were evaluated for this secondary analysis. After adjusting for pre-intervention scores, there was no statistically significant difference in post-treatment Summary scores (excl. FI and QL), or pain scores between the two RT schedules at 5 weeks and 3 months following EBRT. There was a statistically significant relationship between the pretreatment and post-treatment Summary scores (p = .002) but not between the pre-treatment and post-treatment pain scores. INTERPRETATION: Primary radiotherapy for the treatment of MSCC significantly improves QoL in patients not proceeding with surgical decompression. After adjusting for pre-intervention scores, there was no statistically significant difference between a 10 Gy single fraction radiation schedule and one with 20 Gy in five daily fractions on post-treatment QoL Summary scores. For most patients, an effective treatment with low burden would be desirable. A single fraction schedule should be considered for this group of patients.


Assuntos
Fracionamento da Dose de Radiação , Neoplasias/radioterapia , Qualidade de Vida , Compressão da Medula Espinal/radioterapia , Idoso , Idoso de 80 Anos ou mais , Estudos de Equivalência como Asunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/patologia , Compressão da Medula Espinal/etiologia , Resultado do Tratamento
2.
Anaesthesia ; 69(11): 1206-13, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24917449

RESUMO

We investigated the utility of a cell-saver device for processing out-of-date red blood cells, by washing twenty bags of red blood cells that had been stored for between 36 and 55 days. The volume of recovered cells, and the characteristics of the suspension fluid, were measured before and after treatment. The ratio of free haemoglobin to total haemoglobin was up to 0.02 before processing, and up to 0.011 afterwards, changing by between -0.013 and +0.003. This ratio met the current standard for free haemoglobin (less than 0.008 in more than 75% of samples), both before and after processing. Ninety-three percent of red blood cells survived the process. Potassium ion concentration fell from above 15 mmol.l(-1) in all cases, to a mean of 6.4 mmol.l(-1) (p < 0.001). The pH rose to a mean value of 6.44 (p = 0.001). Lactate ion concentration fell to a mean value of 14 mmol.l(-1) (p < 0.001). Sodium ion concentration rose from a mean value of 93 mmol.l(-1) to a mean value of 140 mmol.l(-1) (p < 0.001). A useful proportion of out-of-date red blood cells remained intact after conditioning using a cell-saver, and the process lowered concentrations of potentially toxic solutes in the fluid in which they were suspended.


Assuntos
Preservação de Sangue , Transfusão de Sangue Autóloga/instrumentação , Transfusão de Eritrócitos/métodos , Bancos de Sangue , Coleta de Amostras Sanguíneas , Contagem de Eritrócitos , Hemoglobinas/análise , Humanos , Suspensões
3.
Plant Physiol ; 102(2): 565-571, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12231845

RESUMO

Diacylglycerol acyltransferase (EC 2.3.1.20) activity was assayed during the maturation of seeds of oilseed rape (Brassica napus L.) and safflower (Carthamus tinctorius L.). Developmental studies were also conducted with microspore-derived embryos of oilseed rape (B. napus L. cv Topas) and an embryogenic microspore-derived cell-suspension culture of winter oilseed rape (B. napus L. cv Jet Neuf). In the maturing seeds, diacylglycerol acyltransferase activity increased to a maximum during rapid accumulation of lipid and declined, thereafter, with seed maturity. In microspore-derived embryos of oilseed rape (cv Topas), high levels of diacylglycerol acyltransferase activity were found throughout the early torpedo to late cotyledonary developmental stages with maximum enzyme specific activity associated with the mid-cotyledonary developmental stage. The cell-suspension culture of winter oilseed rape (cv Jet Neuf) contained 3 to 4% triacylglycerol on a dry weight basis and represented about half of the total lipid. The fatty acid profile of total lipid and triacylglycerol in the cell-suspension culture was similar in samples taken during a 1-year period. The Jet Neuf culture contained diacylglycerol acyltransferase with specific activity similar to that of Topas microspore-derived embryos. Jet Neuf diacylglycerol acyltransferase also displayed an enhanced specificity for erucoyl-CoA over oleoyl-CoA when assayed with 14 [mu]M acyl-coenzyme A in the reaction mixture. The specific activity of diacylglycerol acyltransferase in homogenates prepared from the Jet Neuf culture ranged from 5 to 15 pmol of triacylglycerol min-1 mg-1 of protein when assayed at intervals during a period of 1 year. Thus, the cell-suspension culture may represent an attractive tissue source for purification and characterization of triacyl-glycerol biosynthetic enzymes.

4.
Plant Physiol ; 108(2): 563-571, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12228493

RESUMO

Microspore-derived (MD) embryos of Brassica napus L. cv Reston were used to test the effects of (+)-abscisic acid ([(+)-ABA]) and its metabolites, 8[prime]-hydroxyabscisic acid (8[prime]-OH ABA) and (-)-phaseic acid (PA), on the accumulation of very long-chain monounsaturated fatty acids (VLCMFAs) and induction of genes encoding a 19-kD oleosin protein and a [delta]15 desaturase during embryogenesis. Developing early to mid-cotyledonary MD embryos at 16 to 19 d in culture were treated with 10 [mu]M hormone/metabolite for 4 d. At various times during incubation, embryos and medium were analyzed to determine levels of hormone/metabolite, VLCMFAs, and oleosin or [delta]15 desaturase transcripts. The VLCMFAs, 20:1 and 22:1, primarily in triacylglycerols, increased by 200% after 72 h in the presence of (+)-ABA and 8[prime]-OH ABA relative to the control. In contrast, treatment with PA for 72 h had little effect (20% increase) on the level of VLCMFAs. The first 24 to 72 h of (+)-ABA treatment were critical in the induction of VLCMFA biosynthesis, with 8[prime]-OH ABA lagging slightly behind (+)-ABA in promoting this response. The accumulation of VLCMFAs was positively correlated with an increase in elongase activity. (+)-ABA and its 8[prime]-OH ABA metabolite induced the accumulation of a 19-kD oleosin transcript within 2 to 4 h in culture. In addition, both (+)-ABA and 8[prime]-OH ABA induced the same level of [delta]15 desaturase transcript by 8 h. PA had no effect on the induction of either oleosin or [delta]15 desaturase transcripts. To our knowledge, this is the first report of the biological activity of 8[prime]-OH ABA and of stimulatory effects of (+)-ABA and 8[prime]-OH ABA on lipid and oleosin biosynthesis.

5.
Plant Physiol ; 113(2): 549-557, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12223625

RESUMO

The glycerolipid composition of pea (Pisum sativum L.) root plastids and their capacity to synthesize glycerolipids from [UL-14C]glycerol-3-phosphate were determined. Pea root plastids primarily consist of monogalactosyldiacylglycerol, triacylglycerol, phosphatidylcholine, digalactosyldiacylglycerol, and diacylglycerol. Maximum rates of total glycerolipid biosynthesis were obtained in the presence of 2.4 mM glycerol-3-phosphate, 15 mM KHCO3, 0.2 mM sodium-acetate, 0.5 mM each of NADH and NADPH, 0.05 mM coenzyme A, 2 mM MgCl2, 1 mM ATP, 0.1 M Bis-Tris propane (pH 7.5), and 0.31 M sorbitol. Glycerolipid biosynthesis was completely dependent on exogenously supplied ATP, coenzyme A, and a divalent cation, whereas the remaining cofactors improved their activity from 1.3- to 2.4-fold. Radioactivity from glycerol-3-phosphate was recovered predominantly in phosphatidic acid, phosphatidylglycerol, diacylglycerol, and triacylglycerol with lesser amounts in phosphatidylcholine and monoacylglycerol. The proportions of the various radiolabeled lipids that accumulated were dependent on the pH and the concentration of ATP and glycerol-3-phosphate. The data presented indicate that pea root plastids can synthesize almost all of their component glycerolipids and that glycerolipid biosynthesis is tightly coupled to de novo fatty acid biosynthesis. pH and the availability of ATP may have important roles in the regulation of lipid biosynthesis at the levels of phosphatidic acid phosphatase and in the reactions that are involved in phosphatidylglycerol and triacylglycerol biosynthesis.

6.
Curr Top Microbiol Immunol ; 143: 55-69, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2766803

RESUMO

A progressive development of the application of in situ methodology to ultrastructural procedures has resulted in the ability to detect individual molecules of mRNA with high probability. Beginning with whole-mount cells and then developing myotubes, both in culture and detergent extracted before fixation, we were able to progress to methods which allow detection of mRNA in tissue sections. Initial results confirm that the detection of mRNA in thin-sectioned tissue is very similar to observations on the extracted, cultured cells, and that the same methods of data analysis apply. Current work is devoted to the application of the methodology to other cellular structures, such as the nucleus, and to other tissue-probe systems, such as brain. Acknowledgements. The authors appreciate the skilled help from John McNeil and Shirwin Pockwinse in the laborious and time-consuming preparations of material and photography. FS was on sabbatical leave from the Department of Pathology at Southwestern Medical Center.


Assuntos
Sondas de DNA , RNA Mensageiro/metabolismo , Animais , Galinhas , Microscopia Eletrônica , Músculos/metabolismo , Músculos/ultraestrutura , Hibridização de Ácido Nucleico
7.
Int J Radiat Oncol Biol Phys ; 21(4): 1005-11, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1917595

RESUMO

Since 1982, 49 patients with locally advanced carcinoma of the prostate have been treated with pion radiotherapy in tolerance and tumor response studies. The relative biological effectiveness (RBE) was confirmed as 1.5 for both acute and late effects, a figure expected on the basis of animal and human studies. The radiation dose has been safely escalated to tolerance, which is estimated to be 37.5 Gy pi in 15 fractions (volume less than 500 cc), and 36 Gy pi in 15 fractions (volume 500-800 cc). Severe acute toxicity occurred in 6% and severe chronic toxicity in 4%, figures comparable to those seen with conventional radiotherapy. The equivalent photon doses are approximately 78 Gy in 39 fractions and 73 Gy in 36 fractions, respectively. That this high dose can be delivered with no increase in toxicity is a reflection of smaller volume radiotherapy achieved by exploiting the dose distribution and biological characteristics of pions. Local response rates of 94% are reported. A Phase III study is now under way.


Assuntos
Adenocarcinoma/radioterapia , Mésons , Neoplasias da Próstata/radioterapia , Radioterapia de Alta Energia/efeitos adversos , Adenocarcinoma/epidemiologia , Idoso , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/epidemiologia , Dosagem Radioterapêutica , Eficiência Biológica Relativa
8.
Invest Ophthalmol Vis Sci ; 22(2): 145-56, 1982 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-6173345

RESUMO

We examined the effects of cyclic AMP (cAMP) on the growth and differentiation of RAO 188 cells, a cultured cell line derived from a retinoblastoma-like tumor induced in an inbred rat by intravitreous inoculation with human adenovirus serotype 12. After adding cAMP analogs (dibutyryl cAMP and 8-bromo cAMP) and phosphodiesterase inhibitors (theophylline, amino-phylline, and 1-methyl-3-isobutyl xanthine) to the RAO 188 cell culture medium, we measured changes in cell incorporation of the DNA and RNA precursors 14C-thymidine and 3H-uridine, and we observed the morphologic alterations of RAO 188 by phase-contrast and transmission and scanning electron microscopy. Incorporation of the labeled precursors decreased with increased concentrations of cAMP analogs and phosphodiesterase inhibitors. Incorporation of the labeled precursors was inhibited shortly after the addition of dibutyryl cAMP to the culture medium. The effect was maximal at 8 hr and was sustained for up to 48 hr. Reversibility of cAMP effects on incorporation gradually decreased for 10 days; at 10 days these effects were essentially irreversible. Neuritelike processes developed shortly after cAMP analog treatment and formed a network after 24 hr. Transmission electron microscopy disclosed changes in the cell membrane and cytoplasm of cells treated with 8-bromo cAMP and theophylline: perturbation of the cell membrane and the appearance of intercellular junctional devices and microfilaments. The activity of glutamate decarboxylase, which is involved in the biosynthesis of gamma-aminobutyric acid, was increased in treated cells. These results show that cAMP decreases DNA and RNA synthesis and cell proliferation and facilitates morphologic and biochemical differentiation of RAO 188 cells.


Assuntos
AMP Cíclico/fisiologia , Neoplasias Oculares/fisiopatologia , Retinoblastoma/fisiopatologia , Animais , Linhagem Celular , AMP Cíclico/análogos & derivados , DNA/biossíntese , Neoplasias Oculares/ultraestrutura , Técnicas In Vitro , Microscopia Eletrônica , Neoplasias Experimentais/fisiopatologia , Inibidores de Fosfodiesterase , RNA/biossíntese , Ratos , Retinoblastoma/ultraestrutura
9.
Cancer Chemother Pharmacol ; 17(3): 285-8, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3017596

RESUMO

A prospective randomized double-blind trial comparing the butyrophenone analogue domperidone (D) and the synthetic cannabinoid nabilone (N) in the treatment of cytotoxic-induced emesis was conducted in 38 patients receiving highly emetogenic chemotherapy regimens (70% containing cisplatin). Patients received 20 mg D or 1 mg N the night before chemotherapy and 8-hourly on each chemotherapy day for two consecutive cycles of treatment. Three of 19 patients randomized to N completed only one cycle because of disease progression or subjectively adverse effects. Four of 19 patients completed only one cycle of D because of lack of efficacy or chemotherapy toxicity. In all, 32 cycles of N and 33 cycles of D were evaluable for efficacy. The mean number of vomiting episodes in cycle 1 was 4.76 for N and 12.95 for D (P less than 0.02). The corresponding values for cycle 2 were 4.27 and 7.69 (P greater than 0.10), and for cycles 1 and 2 combined, 4.53 for N and 10.81 for D (P less than 0.01). Nausea and food intake scores did not differ significantly, although there was a trend towards less nausea and an increased food intake with N. Subjectively adverse effects were more frequent with N and included drowsiness, dizziness, dry mouth, and postural hypotension. N is superior to D for the control of cytotoxic-induced emesis.


Assuntos
Antieméticos/uso terapêutico , Antineoplásicos/efeitos adversos , Domperidona/uso terapêutico , Dronabinol/análogos & derivados , Vômito/tratamento farmacológico , Adulto , Idoso , Antieméticos/efeitos adversos , Domperidona/efeitos adversos , Método Duplo-Cego , Dronabinol/efeitos adversos , Dronabinol/uso terapêutico , Avaliação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Distribuição Aleatória , Vômito/induzido quimicamente
10.
Anticancer Res ; 3(2): 101-6, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6847128

RESUMO

The effect of two anticancer agents, vincristine (VCR) and cyclophosphamide (CTX), on an established cell line (EXP-5) derived from human adenovirus serotype 12 (Ad 12)--induced retinal tumor was studied in vitro and in vivo. VCR at a concentration of 5 and 10 micrograms/ml of culture medium and CTX at 50 and 100 micrograms/ml suppressed growth in vitro. EXP-5 cells were transplanted into the vitreous of 56 inbred CDF (F 344 strain) rats. The implants grew almost exclusively as intravitreous tumors within one month. When the tumor was full grown in the vitreous, VCR and CTX were administered intravenously, singly or in combination, on a schedule based on the protocol CCG-961 for localized unilateral retinoblastoma, Reese-Ellsworth group 5. At a dosage of 0.05 mg/kg, VCR was effective in reducing tumor size; at a dosage of 5 mg/kg, CTX did not reduce tumor size. Combined VCR/CTX therapy induced reduction of about two thirds in tumor size in 2 of 10 treated animals; in all 10 animals, the tumor became morphologically less distinct during the course of treatment although some characteristic features remained. Cytotoxic tumor changes (necrosis, fibrous proliferation, cell transformation, and bizarre giant cells) were observed in all treated animals. This model used the EXP-5 cell line grown in the vitreous, thereby providing a potential tool for evaluating growth and chemotherapeutic responsiveness of retinoblastoma.


Assuntos
Adenovírus Humanos , Ciclofosfamida/uso terapêutico , Neoplasias Oculares/microbiologia , Retinoblastoma/microbiologia , Vincristina/uso terapêutico , Animais , Linhagem Celular , Neoplasias Oculares/tratamento farmacológico , Neoplasias Oculares/patologia , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/microbiologia , Neoplasias Experimentais/patologia , Ratos , Ratos Endogâmicos F344 , Retinoblastoma/tratamento farmacológico , Retinoblastoma/patologia
11.
Ir J Med Sci ; 159(2): 40-3, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2347677

RESUMO

58 patients under the age of 14 years with acute lymphoblastic leukaemia were managed from 1971 to 1985. We analysed their overall survival from diagnosis to assess the prognostic significance of clinical and laboratory features present at diagnosis. Factors which were statistically significant included white blood count, platelet count, palpable lymph node enlargement, mediastinal widening on chest x-ray and palpable splenic enlargement. The purpose of this study was to identify that subset of patients which might have benefitted from more intensive treatment.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Prognóstico , Fatores de Risco
14.
Am J Nurs ; 69(9): 1886-90, 1969 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-5194633
15.
Plant Physiol ; 55(1): 51-8, 1975 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16659027

RESUMO

The effect of mono-, di-, and trinucleoside phosphates and respiratory inhibitors on respiration in winter wheat (Triticum aestivum L. cv. Rideau) mitochondria has been examined. When added during state 4 respiration, subsequent to addition of ADP, all of the dinucleotides stimulated oxidation and induced respiratory control with all substrates examined. Similar results were obtained with AMP, but other mononucleotides and all trinucleotides did not affect the rate of oxidation. Nucleoside diphosphates did not stimulate respiration when added prior to the addition of ADP, but subsequent addition of AMP, ADP, or ATP re-established coupled respiration in the presence of the dinucleotides.The duration of 2, 4-dinitrophenol stimulated respiration during oxidation of alpha-ketoglutarate was found to be dependent on the amount of AMP, ADP, or ATP added, either prior, or subsequent to, addition of the uncoupler. The addition of oligomycin during 2, 4-dinitrophenol stimulated respiration reestablished coupled respiration with low ADP/O ratios, when added after addition of ATP or conditions which allow formation of ATP from added ADP. The nucleoside diphosphates, other than ADP, did not stimulate oxidation of alpha-ketoglutarate in the presence of 2, 4-dinitrophenol until a small amount of adenine nucleotide was added to the system. The results suggest that dinucleotides other than ADP, are able to participate in the energy conversion processs of the mitochondria, probably via transphosphorylation reactions.

16.
Plant Physiol ; 57(4): 469-73, 1976 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16659507

RESUMO

A comparison of mitochondria isolated from 2 and 24 C grown winter wheat (Triticum aestivum L.) and winter rye (Secale cereale L.) seedlings revealed no correlation between changes in swelling and contraction characteristics and extent of cold hardiness. The swelling response changed markedly due to growth at low temperature, but the change was similar for the four cultivars examined. The swelling response was also observed to change rapidly during aging of isolated mitochondria, either at 2 or 24 C. Spontaneously swollen mitochondria, isolated from 24 C grown seedlings, contracted abruptly upon addition of certain oxidizable substrates, but this response was lost when seedlings were transferred from 24 to 2 C. Studies on the effect of various substrates and respiratory inhibitors on the swelling and contraction responses indicate that inhibitors which reduce or stop electron flow through the electron transport chain also inhibit substrate induced mitochondrial contraction.

17.
Plant Physiol ; 53(4): 653-7, 1974 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16658761

RESUMO

Mitochondria isolated from shoots of 2 days, light- and dark-grown winter wheat (Triticum aestivum L. cv. Rideau) seedlings oxidize alpha-ketoglutarate and l-malate with good respiratory control and ADP: O ratios. The efficiency of oxidative phosphorylation, and respiratory control are both reduced significantly when succinate or NADH is employed as substrate. Respiratory control values and ADP: O ratios show a general decline in mitochondria from seedlings of increasing age, whether grown in light or dark. In light-grown seedlings, the decrease in respiratory control with aging is due principally to a decrease in the rate of state 3 respiration, while in dark-grown material, the decrease appears to be due mainly to an increased rate of state 4 respiration. In both light- and dark-grown seedlings, oxygen consumption during state 3 respiration is severely inhibited by oligomycin. During state 4 respiration, 2,4-dinitrophenol stimulates oxygen uptake to a level approximately two-thirds the normal ADP-stimulated rate.

18.
Plant Physiol ; 59(2): 250-5, 1977 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16659827

RESUMO

Mitochondria isolated from both 2 and 24 C grown winter wheat (Triticum aestivum L.) undergo spontaneous swelling in isomolar KCI solutions, but only 24 C mitochondria exhibit a substrate-induced contraction response. Electron microscopic examination revealed that 24 C mitochondria have more clearly defined cristae, less matrix material, and are generally more electron-dense than 2 C mitochondria. During swelling, the matrix material of both 2 and 24 C mitochondria expands and the mitochondria become less electron-dense. After partial swelling, 24 C mitochondria contract upon addition of succinate, and regain structural characteristics similar to those of untreated mitochondria. In contrast, mitochondria from 2 C seedlings continue to swell after addition of substrate, and many of the mitochondria become irregular in shape and lose much of their matrix material. A comparison of results obtained from absorbancy measurements, electron microscopy, and a Coulter Counter indicate that swelling and contraction involve changes both in over-all volume, and internal structural characteristics of mitochondria from 2 and 24 C grown seedlings. Electron microscopic examination of shoot cells showed that mitochondria in 24 C grown seedlings possessed more recognizable cristae and greater internal organization than mitochondria in 2 C seedlings.

19.
Cytotechnology ; 12(1-3): 385-91, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-7764459

RESUMO

Cellular resistance is a significant component of tumour treatment failure. More detailed understanding of resistance mechanisms has enabled us to plan circumvention strategies, though these are not yet in routine clinical use. Such resistance is, however, only one of several factors which render cure of advanced malignant disease difficult. It is important for researchers in this field to see not only therapeutic opportunities but also limitations of these approaches. It is hoped that increased cooperation between clinicians and scientists in the field of cellular resistance will yield further improvement in tumour response rates and cure.


Assuntos
Antineoplásicos/uso terapêutico , Resistência a Medicamentos , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Tolerância a Radiação , Antineoplásicos/toxicidade , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Reparo do DNA , Terapia Genética , Glicoproteínas/metabolismo , Humanos , Neoplasias/metabolismo , Neoplasias/terapia , Células Tumorais Cultivadas
20.
Plant Physiol ; 56(5): 703-6, 1975 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16659376

RESUMO

The effect of temperature on respiration of mitochondria and tissue segments from three wheat (Triticum aestivum L.) and one rye (Secale cereale L.) cultivar grown at 2 and 24 C has been examined. Discontinuities in Arrhenius plots of respiratory activity against temperature were observed for mitochondria and tissue segments from seedlings grown at both temperatures. The rates of respiration decreased abruptly below the transition temperatures, resulting in increased energy of activation values for respiration. Transition temperatures were observed from 6 to 10 C during tissue segment respiration, and from 10 to 14 C during respiration by isolated mitochondria. Respiratory control and efficiency of phosphorylation were not affected markedly by either reaction temperature or growth temperature of the seedlings. No correlation was observed between the cold hardiness of the cultivars and the temperature at which structural transitions occurred in the mitochondria. Dry matter content of the seedlings increased markedly during growth at 2 C, but no appreciable changes in the levels of mitochondrial protein were observed. The results support the view that changes other than fatty acid unsaturation are involved in the abrupt change in mitochondrial membrane properties at low temperature.

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