Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Immunol Cell Biol ; 78(5): 474-82, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11050529

RESUMO

The purpose of the present study was to quantify the binding affinity between Tamm-Horsfall protein (THP) and complement 1q (C1q) using ELISA and a resonant mirror biosensor. In ELISA, immobilized THP was incubated with soluble C1q under both low and physiological ionic-strength conditions. Tamm-Horsfall protein bound C1q with an equilibrium dissociation constant (KD) of 1.9 +/- 0.6 nmol/L in low ionic-strength Tris buffers (20 mmol/L NaCl, pH 7.5) and with a lower affinity (KD of 13.4 +/- 4.7 nmol/L) in physiological-strength Tris buffers (154 mmol/L NaCl, pH 7.5). A resonant mirror biosensor, which monitors binding events in real-time, was used to quantify the KD of this reaction, as well as to estimate the kinetic parameters. In these studies, THP and C1q bound with an association rate constant, kass, of 1.25 x 105 L/mol per s and a dissociation rate constant, kdiss, of 0.002-0.005/s. The calculated KD for the THP/C1q binding in low ionic-strength buffers was higher (averages of 10-15 nmol/L) than that obtained by the ELISA, while physiological ionic-strength buffers still reduced the affinity of this binding by an order of magnitude. In conclusion, THP consistently bound C1q with high affinity using several techniques. At least a portion of this interaction involved electrostatic events, as demonstrated by the influence of ionic strength on the binding affinity.


Assuntos
Adjuvantes Imunológicos/metabolismo , Complemento C1q/metabolismo , Ensaio de Imunoadsorção Enzimática , Mucoproteínas/metabolismo , Adjuvantes Imunológicos/urina , Adulto , Técnicas Biossensoriais/métodos , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Mucoproteínas/urina , Concentração Osmolar , Ligação Proteica , Reprodutibilidade dos Testes , Eletricidade Estática , Uromodulina
3.
Am J Vet Res ; 55(10): 1474-8, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7998707

RESUMO

Ursodeoxycholic acid (UDCA; 10 mg/kg of body weight) was administered orally to 5 healthy cats for 3 months. Signs of illness were not apparent in any cat during treatment with UDCA. Results of monthly CBC, serum biochemical analysis, and urinalysis were unchanged during drug administration. There was a decrease in serum cholesterol concentration in 4 cats. Total postprandial serum bile acids (PPSBA) concentration was significantly (P = 0.0003) increased over total preprandial serum bile acids (PRSBA) concentration at all sample collection periods. The PRSBA and PPSBA concentrations were significantly (P < 0.05) increased at all sample collection periods after administration of UDCA, compared with baseline values. Ursodeoxycholic and tauroursodeoxycholic acids were not detected in serum prior to initiating administration of UDCA. Both bile acids were detected in the serum of all cats 1 and 2 months after UDCA administration and were detected in the serum of 2 cats 3 months after initiating UCDA administration. Hepatic ultrasonographic findings were normal before and after completion of UDCA administration. A mild, focal lymphocytic infiltrate was observed in 3 cats 3 months after initiating UDCA administration. Results of the study indicate that UDCA is absorbed into the systemic circulation of cats after oral administration, undergoes hepatic conjugation, and appears to be safe.


Assuntos
Ácidos e Sais Biliares/sangue , Gatos/sangue , Ácido Ursodesoxicólico/farmacocinética , Ácido Ursodesoxicólico/toxicidade , Administração Oral , Animais , Feminino , Masculino , Ácido Ursodesoxicólico/administração & dosagem
4.
Am J Surg ; 166(6): 643-7; discussion 647-8, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8273842

RESUMO

In order to explore the histology of false-negative mammograms, 264 consecutive patients with breast cancer were retrospectively reviewed until 100 patients with palpable cancers were identified. These patients were imaged by a dedicated mammographer within 6 months prior to biopsy. Nine of the 100 patients had "negative" readings originally, with 6 of the 9 still regarded as negative when re-examined after full knowledge of the tumor location. Histologic review of these six tumors showed a diffusely infiltrative pattern in five patients (three with invasive lobular carcinomas and two with multifocal, invasive ductal carcinomas). Although background breast density always serves in a critical relationship with tumor density on film, only one of these six patients showed a severe degree of mammographic breast density. Diffuse histology should be recognized as a principal cause of false-negative mammograms. Since mammography is based solely on anatomic contrasts, diffuse histology could easily prevent the perfection of this modality, calling attention to the need for improved adjunct imaging techniques.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/diagnóstico por imagem , Carcinoma Lobular/patologia , Mamografia/normas , Adulto , Idoso , Reações Falso-Negativas , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
Kidney Int ; 44(5): 1014-21, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8264130

RESUMO

Tamm-Horsfall protein (THP), a monomeric glycoprotein (M(r) 80 to 100 kDa), is produced by the mammalian kidney's thick ascending limb of Henle cells and excreted into the urine. The function of THP is uncertain. Here we report that a high molecular weight contaminant in sheep THP (sTHP) preparations was identified as sheep IgG by its positive reaction with donkey anti-sheep IgG antibody and with protein G. To answer the question of whether sTHP and sheep IgG co-purified because of a physical interaction between the two proteins, an enzyme-linked immunosorbent assay (ELISA) using immobilized sTHP and soluble sheep IgG was performed. Analysis of the ELISA data identified the presence of two sets of binding sites: a high affinity site (Kd 10(-8) to 10(-9) M) and a lower affinity site (Kd 10(-6) to 10(-7) M) [corrected]. The ELISA detected a similar high affinity interaction between human THP (hTHP) and human IgG. The binding of sheep IgG to immobilized sTHP was inhibited by soluble sTHP. These observations suggest an additional factor to be considered in studies addressing THP's potential immunoregulatory function.


Assuntos
Imunoglobulina G/metabolismo , Mucoproteínas/metabolismo , Adulto , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Peso Molecular , Mucoproteínas/química , Mucoproteínas/isolamento & purificação , Ovinos , Urina/química , Uromodulina
6.
Zentralbl Veterinarmed A ; 40(4): 283-91, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8342360

RESUMO

The in vitro cation-induced aggregation properties of cat Tamm-Horsfall protein (cTHP), a urinary glycoprotein, were examined and related to the potential role of cTHP in feline urolithiasis. The aggregation assay involved adding either CaCl2, MgCl2, or NaCl to solutions containing purified cTHP, and then separating the aggregated cTHP by centrifugation. The concentration of cTHP remaining in the supernatant was quantified using a previously developed enzyme-linked immunosorbent assay (ELISA). The effect that buffer pH, cTHP concentration, and urea concentration had on cTHP aggregation also were examined. Of the three salts, CaCl2 consistently was most efficient at precipitating cTHP, while MgCl2 was slightly less efficient. At least ten times more NaCl than CaCl2 or MgCl2 was required for comparable cTHP aggregation. As the pH decreased, increasing concentrations of the salts were required to aggregate cTHP. Increased amounts of CaCl2 and MgCl2 also were required to aggregate cTHP when the urea concentration was increased. As cTHP concentration increased within the physiological range, lower concentrations of CaCl2 and MgCl2 were required to precipitate 50% of the cTHP. Several aspects of the in vitro aggregation properties of cTHP correlate closely with previously identified risk factors for feline urolithiasis, strengthening the theory that cTHP aggregation may be important in this disease.


Assuntos
Doenças do Gato/etiologia , Mucoproteínas/metabolismo , Cálculos Urinários/veterinária , Animais , Cloreto de Cálcio/farmacologia , Gatos , Precipitação Química , Cloreto de Magnésio/farmacologia , Masculino , Mucoproteínas/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Cálculos Urinários/etiologia , Uromodulina
7.
Zentralbl Veterinarmed A ; 39(8): 621-34, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1455930

RESUMO

A precise and reproducible enzyme-linked immunosorbent assay (ELISA) which measures urinary cat Tamm-Horsfall glycoprotein (cTHP) was developed in order to investigate the possible role of cTHP in the pathogenesis of feline urolithiasis. Reproducible quantification required that the cTHP be disaggregated with 2M urea and 0.05% Tween 20. It was necessary to standardize rigidly the handling of the samples prior to analysis, since the apparent cTHP concentration varied depending on the preanalysis protocols. Using the sample handling protocol of freezing urine at -70 degrees C before dialysis, urinary cTHP was quantified in male cats with no history of urolithiasis ("normal" cats) and in male cats with a history of urolith formation ("urolithiasis" cats). The mean cTHP concentration in adult, male "normal" cats of 49.2 +/- 35.5 micrograms/ml (N = 23) was significantly lower than the mean cTHP concentration of 95.4 +/- 34.1 micrograms/ml (N = 9) in "urolithiasis" cats (p < 0.01, Students' T-test). These findings indicate a correlation between urolithiasis and high urine cTHP concentrations in male cats which warrants further investigation.


Assuntos
Doenças do Gato/urina , Ensaio de Imunoadsorção Enzimática/veterinária , Mucoproteínas/urina , Cálculos Urinários/veterinária , Análise de Variância , Animais , Gatos , Masculino , Reprodutibilidade dos Testes , Cálculos Urinários/urina , Uromodulina
8.
J Okla State Med Assoc ; 82(9): 459-62, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2809812

RESUMO

Preoperative needle localization prior to biopsy of nonpalpable mammographic abnormalities is a widely accepted procedure. The experience of the first 100 localizations performed at the University of Oklahoma is reviewed.


Assuntos
Biópsia por Agulha , Neoplasias da Mama/diagnóstico , Mamografia , Adulto , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade
11.
Vet Clin Pathol ; 7(2): 11-3, 1978.
Artigo em Inglês | MEDLINE | ID: mdl-15334342

RESUMO

Intramuscular injections of compounds of low irritancy (bicillin, valium, saline) were found to cause significant elevations in serum CPK in dogs. This route of treatment must therefore be avoided in clinical conditions where CPK values have diagnostic or prognostic importance.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...