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1.
Plant Growth Regul ; 32(2-3): 161-72, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11758564

RESUMO

Recent investigations of the biochemistry, physiology and molecular genetics of polar auxin transport have greatly advanced our understanding of the process and of the part it plays in the regulation of development and in the responses of cells, tissues and organs to internal and external stimuli. The molecular and physiological characterization of mutants which exhibit lesions in polar auxin transport has led to the isolation and sequencing of genes which encode putative components of auxin carrier systems, or proteins which directly or indirectly regulate these systems. This work has revealed that specific auxin uptake and efflux carriers are coded not by single genes, but by whole families of genes, the expression of which is tissue or stimulus specific. Furthermore, evidence is accumulating rapidly that at least the auxin efflux carrier is a multi-component system consisting of both catalytic and regulatory subunits, including a separate phytotropin-binding protein. Other genes have been tentatively identified which code proteins that regulate the expression of genes coding auxin carrier components, or which regulate the intracellular traffic or activity of auxin carriers. Investigations of the turn-over and Golgi-mediated trafficking of auxin carrier proteins have revealed that essential components of at least the efflux carrier have a very short half-life in the plasma membrane and are replaced without the need for concurrent protein synthesis, leading to speculation that they might cycle between internal stores and the plasma membrane. The way is now clear for the development of specific molecular probes with which to investigate the intracellular transport and targeting of auxin carrier proteins.


Assuntos
Arabidopsis/genética , Proteínas de Transporte/metabolismo , Genes de Plantas , Ácidos Indolacéticos/metabolismo , Proteínas de Plantas/metabolismo , Ácido 2,4-Diclorofenoxiacético/metabolismo , Arabidopsis/metabolismo , Transporte Biológico Ativo , Proteínas de Transporte/genética , Complexo de Golgi/genética , Complexo de Golgi/metabolismo , Herbicidas/metabolismo , Ácidos Indolacéticos/genética , Mutação , Ftalimidas/metabolismo , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética
2.
Arch Ophthalmol ; 117(9): 1149-54, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10496386

RESUMO

PURPOSE: Postoperative release of scleral flap closure suture is useful in trabeculectomy combined with cataract surgery. We determined risk factors for early filtration failure requiring suture release during the first month after primary glaucoma triple procedure. METHODS: The medical records of 71 consecutive patients with primary open-angle glaucoma who underwent a primary glaucoma triple procedure (primary trabeculectomy, phacoemulsification, and posterior chamber intraocular lens implantation) were reviewed. Suture release had been performed in 24 of the patients for early filtration failure with postoperative intraocular pressure greater than the target value during the first postoperative month. The long-term filtration failure was defined according to 2 criteria based on medical dependency and requirement of additional surgical procedure for intraocular pressure control. Cox proportional hazards multivariate analysis was performed to identify independent risk factors. RESULTS: African American race (P = .02), more than 2 preoperative glaucoma drugs (P = .02), and intraocular pressure greater than 14 mm Hg during the first postoperative week (P = .006) were identified as significant independent risk factors requiring suture release for filtration failure during the first postoperative month. Their significance was further confirmed by Kaplan-Meier survival analysis with Mantel-Cox log-rank test (P = .03, P = .02, and P = .001, respectively). CONCLUSIONS: African American race, more than 2 preoperative medications, and intraocular pressure greater than 14 mm Hg in the first postoperative week are major independent risk factors for initial filtration failure requiring suture release during the first month after primary glaucoma triple procedure. Presence of the risk factors may warrant a more aggressive antiproliferative regimen and/or earlier suture release.


Assuntos
Glaucoma de Ângulo Aberto/terapia , Implante de Lente Intraocular , Mitomicinas/uso terapêutico , Facoemulsificação , Técnicas de Sutura , Trabeculectomia , Idoso , Quimioterapia Adjuvante , Feminino , Glaucoma de Ângulo Aberto/etnologia , Humanos , Pressão Intraocular , Masculino , Análise Multivariada , Complicações Pós-Operatórias , Fatores de Risco , Esclera/cirurgia , Falha de Tratamento
3.
Am J Ophthalmol ; 127(2): 213-6, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10030570

RESUMO

PURPOSE: To implant foldable posterior chamber intraocular lenses in the absence of capsular and zonular support. METHODS: Case reports. In two patients, two eyes with aphakia, lack of capsular or zonular support, and contact lens intolerance underwent the implantation of a silicone and an acrylic foldable posterior chamber intraocular lens, respectively. RESULTS: In the two eyes, final visual acuity was 20/25 and 20/50, respectively. No intraoperative vitreal, retinal, or choroidal complications were noted. The postoperative recovery was rapid, and there was minimal induced astigmatism. CONCLUSIONS: The implantation of foldable posterior chamber intraocular lenses in aphakic eyes without capsular and zonular support may result in fewer intraoperative complications. It also allows for faster postoperative recovery and less postoperative astigmatism.


Assuntos
Afacia Pós-Catarata/cirurgia , Cápsula do Cristalino , Implante de Lente Intraocular , Lentes Intraoculares , Ligamentos , Acrilatos , Adulto , Humanos , Cápsula do Cristalino/patologia , Ligamentos/patologia , Masculino , Pessoa de Meia-Idade , Elastômeros de Silicone , Acuidade Visual
4.
J Glaucoma ; 7(6): 417-9, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9871865

RESUMO

PURPOSE: To report the use of autologous Tenon's and partial-thickness scleral tissues for patch graft revisions of excessively draining fistulas associated with leaking filtering blebs. METHODS: Appropriate sized pieces of autologous Tenon's tissue and partial-thickness scleral tissue were dissected near the surgical sites and used as patch grafts to effectively repair excessively draining fistulas with leaking filtering blebs. RESULTS: Both Tenon's and partial-thickness scleral patch grafts were useful in adequately closing the excessively draining fistulas. CONCLUSION: Autologous Tenon's and scleral tissue patch grafts appear to be safe and effective for the repair of excessively draining fistulas, and are useful when patch grafts are unexpectedly needed.


Assuntos
Doenças da Túnica Conjuntiva/cirurgia , Fáscia/transplante , Cirurgia Filtrante/efeitos adversos , Fístula/cirurgia , Esclera/transplante , Idoso , Doenças da Túnica Conjuntiva/etiologia , Exsudatos e Transudatos , Feminino , Fístula/etiologia , Glaucoma/cirurgia , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Transplante Autólogo
5.
Am J Hypertens ; 7(10 Pt 1): 933-6, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7826558

RESUMO

Pregnancy-induced hypertension and preeclampsia are relatively common in nulliparous, inner-city, African-American, pregnant women and contribute to considerable maternal, fetal, and neonatal morbidity and mortality in that population. Recently, insulin resistance has been related to the development of hypertension in young African-Americans and hyperinsulinemia and elevated insulin-to-glucose ratios, suggesting insulin resistance, have been demonstrated in women with preeclampsia. To investigate whether insulin resistance existed postpartum and, therefore, independently of the pregnant state, the hyperinsulinemic, euglycemic technique was used 3 to 6 months postpartum to assess insulin sensitivity in 10 young, black, primiparous, inner-city women with recent preeclampsia and seven age-, weight- and body-mass-index-matched black women with healthy pregnancies. The age, weight, body-mass index, waist-to-hip ratio, the duration since parturition, and fasting plasma glucose and insulin were similar in the preeclamptic and control groups. During the clamp procedure, the insulin levels and mean diastolic blood pressure and mean arterial pressure were also similar for both groups; however, the mean systolic blood pressure of the preeclamptic group (123 +/- 3 mm Hg) was higher than that of the control group (114 +/- 2 mm Hg) (P < .05). Insulin-stimulated glucose disposal was not different between the preeclamptic (5.6 +/- 0.3 mg/kg/min) and control groups (5.7 +/- 0.7 mg/kg/min). This suggests that the elevation in postpartum systolic blood pressure may reflect a persistent abnormality of blood pressure homeostasis which is not associated with insulin resistance.


Assuntos
População Negra , Pressão Sanguínea , Resistência à Insulina , Período Pós-Parto , Pré-Eclâmpsia/etnologia , Pré-Eclâmpsia/fisiopatologia , Adolescente , Adulto , Índice de Massa Corporal , Feminino , Técnica Clamp de Glucose , Teste de Tolerância a Glucose , Humanos , Análise por Pareamento , Gravidez
7.
Planta ; 186(2): 219-26, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24186661

RESUMO

The characteristics of transmembrane transport of (14)C-labelled indol-3yl-acetic acid ([1-(14)C]IAA) were compared in Chlorella vulgaris Beij., a simple unicellular green alga, and in Chara vulgaris L., a branched, multicellular green alga exhibiting axial polarity and a high degree of cell and organ specialization. In Chara thallus cells, three distinguishable trans-plasmamembrane fluxes contributed to the net uptake of [1-(14)C]-IAA from an external solution, viz.: a non-mediated, pH-sensitive influx of undissociated IAA (IAAH); a saturable influx of IAA; and a saturable efflux of IAA. Both saturable fluxes were competitively inhibited by unlabelled IAA. Association of [(3)H]IAA with microsomal preparations from Chara thallus tissue was competitively inhibited by unlabelled IAA. Results indicated that up-take carriers occurred in the membranes at a much higher density than efflux carriers. The efflux component of IAA net uptake by Chara was not affected by several phytotropins (N-1-naphthylphthalmic acid, NPA; 2-(1-pyrenoyl)benzoic acid; and 5-(2-carboxyphenyl)-3-phenylpyrazole), which are potent non-competitive inhibitors of specific auxin-efflux carriers in more advanced plant groups, and no evidence was found for a specific association of [(3)H]NPA with Chara microsomal preparations. It was concluded that Chara lacked phytotropin receptors. Net uptake of [1-(14)C]IAA also was unaffected by 2,3,5-triiodobenzoic acid except at concentrations (≥ 10(-1) mol · m(-3)) high enough to depress cytoplasmic pH (determined by uptake of 5,5-dimethyloxazolidine-2,4-dione). Chlorella cells accumulated [1-(14)C]IAA from an external solution by pH-sensitive diffusion of IAA across the plasma membrane and anion (IAA(-)) trapping, but no evidence was found in Chlorella for the occurrence of IAA carriers. These results indicate that carrier systems capable of mediating the transmembrane transport of auxins appeared at a very early stage in the evolution of green plants, possibly in association with the origin of a differentiated, multicellular plant body. Phytotropin receptors evolved independently of the carriers.

8.
Planta ; 181(1): 117-24, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24196683

RESUMO

Correlatively inhibited pea shoots (Pisum sativum L.) did not transport apically applied (14)C-labelled indol-3yl-acetic acid ([(14)C]IAA), and polar IAA transport did not occur in internodal segments cut from these shoots. Polar transport in shoots and segments recovered within 24 h of removing the dominant shoot apex. Decapitation of growing shoots also resulted in the loss of polar transport in segments from internodes subtending the apex. This loss was prevented by apical applications of unlabelled IAA, or by low temperatures (approx. 2° C) after decapitation. Rates of net uptake of [(14)C]IAA by 2-mm segments cut from subordinate or decapitated shoots were the same as those in segments cut from dominant or growing shoots. In both cases net uptake was stimulated to the same extent by competing unlabelled IAA and by N-1-naphthylphthalamic acid. Uptake of the pH probe [(14)C]-5,5-dimethyloxazolidine-2,4-dione from unbuffered solutions was the same in segments from both types of shoot. Patterns of [(14)C]IAA metabolism in shoots in which polar transport had ceased were the same as those in shoots capable of polar transport. The reversible loss of polar IAA transport in these systems, therefore, was not the result of loss or inactivation of specific IAA efflux carriers, loss of ability of cells to maintain transmembrane pH gradients, or the result of a change in IAA metabolism. Furthermore, in tissues incapable of polar transport, no evidence was found for the occurrence of inhibitors of IAA uptake or efflux. Evidence is cited to support the possibility that the reversible loss of polar auxin transport is the result of a gradual randomization of effluxcarrier distribution in the plasma membrane following withdrawal of an apical auxin supply and that the recovery of polar transport involves reestablishment of effluxcarrier asymmetry under the influence of vectorial gradients in auxin concentration.

9.
Planta ; 178(2): 242-8, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-24212754

RESUMO

The transport of exogenous indol-3yl-acetic acid (IAA) from the apical tissues of intact, light-grown pea (Pisum sativum L. cv. Alderman) shoots exhibited properties identical to those associated with polar transport in isolated shoot segments. Transport in the stem of apically applied [1-(14)C]-or [5-(3)H]IAA occurred at velocities (approx. 8-15 mm·h(-1)) characteristic of polar transport. Following pulse-labelling, IAA drained from distal tissues after passage of a pulse and the rate characteristics of a pulse were not affected by chases of unlabelled IAA. However, transport of [1-(14)C]IAA was inhibited through a localised region of the stem pretreated with a high concentration of unlabelled IAA or with the synthetic auxins 1-napthaleneacetic acid and 2,4-dichlorophenoxyacetic acid, and label accumulated in more distal tissues. Transport of [1-(14)C]IAA was also completely prevented through regions of the intact stem treated with N-1-naphthylphthalamic acid (NPA) and 2,3,5-triiodobenzoic acid.Export of IAA from the apical bud into the stem increased with total concentration of IAA applied (labelled+unlabelled) but approached saturation at high concentrations (834 mmol·m(-3)). Transport velocity increased with concentration up to 83 mmol·m(-3) IAA but fell again with further increase in concentration.Stem segments (2 mm) cut from intact plants transporting apically applied [1-(14)C]IAA effluxed 93% of their initial radioactivity into buffer (pH 7.0) in 90 min. The half-time for efflux increased from 32.5 to 103.9 min when 3 mmol·m(-3) NPA was included in the efflux medium. Long (30 mm) stem sections cut from immediately below an apical bud 3.0 h after the apical application of [1-(14)C]IAA effluxed IAA when their basal ends, but not their apical ends, were immersed in buffer (pH 7.0). Addition of 3 mmol·m(-3) NPA to the external medium completely prevented this basal efflux.These results support the view that the slow long-distance transport of IAA from the intact shoot apex occurs by polar cell-to-cell transport and that it is mediated by the components of IAA transmembrane transport predicted by the chemiosmotic polar diffusion theory.

11.
Adolescence ; 23(92): 873-80, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3232574

RESUMO

Thirty cystic fibrosis (CF) and 30 matched control children and their parents were administered several psychiatric inventories including the child (DICA) and parent (DICA-P) versions of the Diagnostic Interview for Children and Adolescents, the Child Behavior Check List, the Hopelessness Scale, and the Piers-Harris Children's Self-Concept Scale. Data analysis revealed few differences in either psychopathological symptoms or psychiatric diagnoses between the CF and control children. The differences which did emerge were either physical in nature (reflecting somatic complaints) or did not depart enough from normal scores to merit the label of high psychopathology. The results are discussed in terms of the growing evidence that CF children do not suffer from greater psychopathology than do normal children.


Assuntos
Fibrose Cística/psicologia , Desenvolvimento da Personalidade , Autoimagem , Papel do Doente , Adaptação Psicológica , Adolescente , Criança , Feminino , Humanos , Masculino , Testes de Personalidade , Psicometria
12.
Br J Clin Pharmacol ; 24(4): 493-501, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2825746

RESUMO

1. The plasma concentrations and urinary excretion of nedocromil sodium have been determined following single dose administration in six healthy volunteers dosed orally (1 mg kg-1) and intravenously (0.2 microgram kg-1 for 30 min). Similar parameters were measured in six volunteers and twelve asthmatic patients dosed by inhalation (4 mg). Multiple dose kinetic measurements were also made. 2. The intravenous data demonstrated that nedocromil sodium is a high clearance drug (10.2 +/- 1.3 ml min-1 kg-1). The data were fitted by a two compartment model with very rapid elimination from the central compartment (k10 = 0.088 +/- 0.021 min-1; beta = 0.013 +/- 0.002 min-1). 81% of the dose was excreted in the urine. 3. Oral absorption was low (2-3% of the dose) and contributed negligibly to the plasma profile after inhalation. 4. After inhalation of single doses of 4 mg in volunteers and patients plasma concentration rose rapidly, plateaued and then fell monoexponentially with a half-life of approximately 2 h. The data fitted a 'flip-flop' model with two absorption components. The extent of absorption was up to 6% of the dose with less in patients. 5. After multiple dosing with 4 mg four times daily for 7 days in volunteers negligible accumulation was observed. The pattern was similar in patients treated with 4 mg four times daily after 1, 6 and 12 months.


Assuntos
Pneumopatias Obstrutivas/tratamento farmacológico , Quinolinas/farmacocinética , Administração por Inalação , Administração Oral , Adulto , Disponibilidade Biológica , Feminino , Humanos , Injeções Intravenosas , Pneumopatias Obstrutivas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nedocromil , Quinolinas/administração & dosagem , Quinolinas/uso terapêutico
13.
J Biol Chem ; 262(7): 2994-3001, 1987 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-3029097

RESUMO

The structure of five sulfated oligosaccharide units of highly anionic tracheobronchial mucous glycoproteins, isolated from a cystic fibrosis patient's sputum, were established. Reduced oligosaccharides (84%) were released under alkaline borohydride conditions, and the acidic oligosaccharides (63%) were isolated by Dowex 1-X2 chromatography. Following the removal of acidic oligosaccharides possessing N-acetylneuraminic acid and L-fucose by lectin affinity chromatography a heterogeneous mixture of sulfated oligosaccharides was obtained. From this fraction, five short chain monosulfated oligosaccharides (S-I to S-V) were purified by sequential separation by SynChroprep AX300 anion exchange high pressure liquid chromatography, gel filtration on Bio-Gel P-2, and high voltage paper electrophoresis. Based on the results of carbohydrate composition, sequential exoglycosidase degradation, permethylation analysis, lectin affinity chromatography, and periodate oxidation, the following structures (where GalNAcol is N-acetylgalactosaminitol) were proposed for these oligosaccharides. (formula; see text)


Assuntos
Brônquios/metabolismo , Glicoproteínas/análise , Muco/análise , Oligossacarídeos/isolamento & purificação , Sulfatos/metabolismo , Traqueia/metabolismo , Adolescente , Configuração de Carboidratos , Carboidratos/análise , Cromatografia , Fibrose Cística/metabolismo , Glicoproteínas/metabolismo , Glicosídeo Hidrolases/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Masculino , Metilação , Muco/metabolismo , Ácido Periódico
14.
Ophthalmology ; 94(1): 56-60, 1987 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3561958

RESUMO

A 66-year-old white woman had had a 20-year history of flat primary acquired melanosis involving the left inferior forniceal and palpebral conjunctiva. Over the ensuring 12 years, the patient experienced multiple recurrences of invasive malignant melanoma that emerged from the progressive primary acquired melanosis. Two of these recurrences were composed of nonpigmented spindle cells, and in the most florid invasive malignant melanoma that developed, the spindle cells formed a nodule 7.5 mm thick. The spindle cells were organized into fascicles and small bundles, the latter separated by a loose stroma that was devoid of mucopolysaccharides. The fascicular and neuroidal features in this case were sufficiently well developed to suggest the incorrect diagnosis of a neural tumor or a neurofibroma. However, the presence of intraepithelial atypical melanocytes at the edge of the spindle cell lesion, the absence of mucopolysaccharides in the stroma, the mitotic activity, and the absence of intercellular reticulin fibers favored the diagnosis of a spindle cell invasive malignant melanoma. This morphologic variant of conjunctival melanoma is compared with related cutaneous lesions of melanoma featuring a spindle cell population.


Assuntos
Neoplasias da Túnica Conjuntiva/ultraestrutura , Melanoma/ultraestrutura , Recidiva Local de Neoplasia , Idoso , Neoplasias da Túnica Conjuntiva/diagnóstico , Neoplasias da Túnica Conjuntiva/cirurgia , Diagnóstico Diferencial , Erros de Diagnóstico , Feminino , Humanos , Melanoma/diagnóstico , Melanoma/cirurgia , Lesões Pré-Cancerosas/diagnóstico
15.
Planta ; 172(3): 400-7, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24225925

RESUMO

Phenylacetic acid (PAA), a naturally-occurring acidic plant growth substance, was readily taken up by pea (Pisum sativum L. cv. Alderman) stem segments from buffered external solutions by a pH-dependent, non-mediated diffusion. Net uptake from a 0.2 µM solution at pH 4.5 proceeded at a constant rate for at least 60 min and, up to approx. 100 µM, the rate of uptake was directly proportional to the external concentration of the compound. The net rate of uptake of PAA was not affected by the inclusion of indol-3yl-acetic acid (IAA) in the uptake medium (up to approx. 30 µM) and, unlike the net uptake of IAA, was not stimulated by N-1-naphthylphthalamic acid (NPA) or 2,3,5-triiodobenzoic acid. At an external concentration of 0.2 µM and pH 4.5, the net rate of uptake of PAA was about twice that of IAA. It was concluded that the uptake of PAA did not involve the participation of carriers and that PAA was not a transported substrate for the carriers involved in the uptake and polar transport of IAA. Nevertheless, the inclusion of 3-100 µM unlabelled PAA in the external medium greatly stimulated the uptake by pea stem segments of [1-(14)C]IAA (external concentration 0.2 µM). It was concluded that whilst PAA was not a transported substrate for the NPA-sensitive IAA efflux carrier, it interacted with this carrier to inhibit IAA efflux from cells. Over the concentration range 3-100 µM, PAA progressively reduced the stimulatory effect of NPA on IAA uptake, indicating that PAA also inhibited carrier-mediated uptake of IAA. The consequences of these observations for the regulation of polar auxin transport are discussed.

16.
Planta ; 172(3): 408-16, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24225926

RESUMO

The transport of [(14)C]phenylacetic acid (PAA) in intact plants and stem segments of light-grown pea (Pisum sativum L. cv. Alderman) plants was investigated and compared with the transport of [(14)C]indiol-3yl-acetic acid (IAA). Although PAA was readily taken up by apical tissues, unlike IAA it did not undergo long-distance transport in the stem. The absence of PAA export from the apex was shown not to be the consequence of its failure to be taken up or of its metabolism. Only a weak diffusive movement of PAA was observed in isolated stem segments which readily transported IAA. When [1-(14)C]PAA was applied to a mature foliage leaf in light, only 5.4% of the (14)C recovered in ethanol extracts (89.6% of applied (14)C) had been exported from the leaf after 6.0 h. When applied to the corresponding leaf, [(14)C]sucrose was readily exported (46.4% of the total recovered ethanol-soluble (14)C after 6.0 h). [1-(14)C]phenylacetic acid applied to the root system was readily taken up but, after 5.0 h, 99.3% of the recovered (14)C was still in the root system.When applied to the stem of intact plants (either in lanolin at 10 mg·g(-1), or as a 10(-4) M solution), unlabelled PAA blocked the transport through the stem of [1-(14)C]IAA applied to the apical bud, and caused IAA to accumulate in the PAA-treated region of the stem. Applications of PAA to the stem also inhibited the basipetal polar transport of [1-(14)C]IAA in isolated stem segments. These results are consistent with recent observations (C.F. Johnson and D.A. Morris, 1987, Planta 172, 400-407) that no carriers for PAA occur in the plasma membrane of the light-grown pea stem, but that PAA can inhibit the carrier-mediated efflux of IAA from cells. The possible functions of endogenous PAA are discussed and its is suggested that an important role of the compound may be to modulate the polar transport and-or accumulation by cells of IAA.

17.
Pediatr Pulmonol ; 1(3): 145-8, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-4058960

RESUMO

Forced oscillatory respiratory resistance was measured in 138 healthy children aged 2- to 16-years-old using a commercial unit. Regression analysis was performed using the resistance measurements obtained at frequencies of 6 Hz and 26 Hz and averages of measurements obtained at frequencies of from 6-26 Hz, 6-10 Hz, and 22-26 Hz. The analysis suggested that regression curves and 95% confidence intervals obtained using a quadratic model with height as the independent variable provided the best prediction of normal values and their ranges. Three independent sets of resistance measurements, which were obtained for all 138 subjects, were used to calculate the average individual coefficients of variation (CV) for the five resistance parameters noted above; these ranged from 9 to 13%. This analysis suggested that the expected CV of repeated measurements would be about 10%. Finally, values from 13 children who had asthma with mild bronchial obstruction (FEV1 less than 80% of predicted) were compared with the normal values derived from the regression curves. Values from all but two of the children fell within the reference intervals, suggesting that FEV1 may be a more sensitive measure of obstruction than forced oscillatory resistance. The main applications of this new approach may be in the evaluation of young children, in following individual patients, and in bronchodilation and bronchial challenge tests.


Assuntos
Resistência das Vias Respiratórias , Adolescente , Obstrução das Vias Respiratórias/fisiopatologia , Asma/fisiopatologia , Criança , Pré-Escolar , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Modelos Teóricos , Valores de Referência , Análise de Regressão
18.
Ophthalmology ; 91(7): 867-72, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6472825

RESUMO

Histopathologic examination of forniceal conjunctival lesions excised from five young patients revealed granulomatous inflammation surrounding filamentous foreign material. Polarization microscopy, special histochemical stains, scanning electron microscopy and energy dispersive x-ray elemental analysis identified the inciting material as predominantly synthetic fabric fiber. Three of these cases initially were diagnosed as conjunctivitis nodosa, an inflammatory reaction to caterpillar setae. Many synthetic fibers contained numerous granules of titanium, barium, or zinc delustering agent, which served to differentiate them from natural fibers or caterpillar hairs. Synthetic fabric fiber is a previously unrecognized cause of conjunctival inflammatory mass lesions.


Assuntos
Doenças da Túnica Conjuntiva/etiologia , Conjuntivite/diagnóstico , Corpos Estranhos no Olho/complicações , Granuloma/etiologia , Adolescente , Criança , Pré-Escolar , Doenças da Túnica Conjuntiva/diagnóstico , Diagnóstico Diferencial , Corpos Estranhos no Olho/diagnóstico , Feminino , Granuloma/diagnóstico , Humanos , Masculino
19.
Biochim Biophys Acta ; 599(2): 380-90, 1980 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6893279

RESUMO

Several photo-physical methods together with 31P-NMR have been used to investigate the effect of lysophosphatidylcholine on phosphatidylcholine bilayers. 31P-NMR shows that the permeability of the vesicle to Eu3+ increases sharply above approx. 40% lysophosphatidylcholine: fluorescence-quenching studies also show this type of behavior. Similar sharp changes in vesicle properties are observed via the photo-physical technique at this lysophosphatidylcholine/phosphatidylcholine composition. Fluorescence spectra of pyrene and pyrene carboxaldehyde show that increasing lysophosphatidylcholine composition increases the polarity of the environments of these probes up to 40% lysocompound. Above this composition the photo-physical properties of the probes slowly revert to those characteristic of the micellar lyso-compound. The pyrene fluorescence lifetime, the fine structure of the fluorescence, and the case of formation of pyrene excimer in these bilayer mixtures suggest that pyrene complexes weakly with the charged nitrogen of the choline group of the phosphatidylcholine and that the physical state of the system has a striking effect on this complexation process. Similar experiments with simple quaternary compounds lend strong support to this suggestion. The studies monitor in several ways the effect of bilayer composition on movement of molecules in these systems. The degree or site of solubilization of carcinogens is also uniquely affected by composition.


Assuntos
Bicamadas Lipídicas , Lisofosfatidilcolinas , Fosfatidilcolinas , Cinética , Espectroscopia de Ressonância Magnética , Surfactantes Pulmonares , Pirenos , Espectrometria de Fluorescência , Temperatura
20.
Planta ; 149(4): 327-31, 1980 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24306367

RESUMO

The putative auxin-transporting cells of the intact herbaceous dicotyledon are the young, differentiating vascular elements. The length of these cells was found to be considerably greater in dwarf (Meteor) than in tall (Alderman) varieties ofPisum sativum L., and to be greater in etiolated than in light-grown plants ofP. sativum cv Meteor andPhaseolus vulgaris L. cv Mexican Black. Under given light conditions during transport these large differences in cell length did not influence the shapes of the transport profiles or the velocity of transport of(14)C-labelled indol-3yl-acetic acid (IAA) applied to the apical bud. However, in both etiolated and light-grown bean and dwarf pea plants the velocity of transport in darkness was ca. 25% lower than that in light. Under the same conditions of transport velocities in bean were about twice those observed in the dwarf pea. Exposure to light during transport increased the rate of export of(14)C from the labelled shoot apex in green dwarf pea plants but not in etiolated plants. The light conditions to which the plants were exposed during growth and transport had little effect on the rates of uptake of IAA from the applied solutions. The results indicate that the velocity of auxin transport is independent of the frequency of cell-to-cell interfaces along the transport pathway and it is suggested that in intact plants auxin transport is entirely symplastic.

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