RESUMEN
The aim of this study was the immunolocalization of transitional cell carcinoma of the bladder with a radiolabelled murine tumour-associated monoclonal antibody and the measurement of the absolute uptake of the antibody by the tumour. Fourteen patients with transitional cell carcinoma of the bladder received 3-6 mCi (111-222 MBq) of technetium-99m labelled HMFG1 monoclonal antibody intravesically and one patient, 2 mCi (74 MBq) of iodine-131 labelled 11.4.1, which is a non-tumour-specific monoclonal antibody. Four of the 15 patients were evaluated with single-photon emission tomography (SPET) 1 1/2 to 2 h post administration. All patients underwent transurethral resection of the bladder tumour within 12-20 h following intravesical administration of the radiolabelled antibody. The radioactivity of biopsy specimens from normal urothelium and tumour areas were counted in a gamma counter. The mean uptake of the radiolabelled antibodies from normal and tumour sites was expressed as a percentage of the administered dose per kilogram of tissue. Conventional histology and immunohistochemistry using HMFG1 monoclonal antibody were performed on paraffin sections of the biopsy specimens. Although our results are preliminary, it can be concluded that: (a) bladder tumours are well imaged by SPET when using 99mTc-HMFG1; (b) intravesically administered radiolabelled antibody remains on the bladder tissue and does not escape into the systemic circulation; (c) the wide range of tumour uptake values (0%-9.3% administered dose/kg) observed probably can be attributed to heterogeneity of the antigenic expression of the tumour; (d) values of 99mTc-HMFG1 monoclonal antibody uptake by the tumour do not justify future attempts at radioimmunotherapy.
Asunto(s)
Carcinoma de Células Transicionales/diagnóstico por imagen , Radioinmunodetección/métodos , Neoplasias de la Vejiga Urinaria/diagnóstico por imagen , Administración Intravesical , Humanos , Radioisótopos de Yodo , Tecnecio , Factores de Tiempo , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
Ten patients with transitional cell carcinoma (TCC) of the bladder received 3-6 mCi of HMFG1 monoclonal antibody (MAb) intravesically. The antibody was labeled with Tc-99m using the 2-Iminothiolane method. All patients underwent transurethral resection of the bladder tumor within 12-20 h following intravesical administration of 99m-Tc-HMFG1. The presence of the radiolabeled MAb in the circulation was studied by measuring the radioactivity in the serum for a period up to 20 h. Three of 10 patients underwent immunoscintigraphy (SPECT) 2-3 h postadministration and cancerous areas could be easily localized. Biopsies were taken from the tumor sites as well as from normal bladder mucosa. Absolute uptake of the administered MAb expressed as percent administered dose/kg of tissue could be evaluated only in eight patients. Multiple specimen taken from various tumor sites in every patient gave a wide range of uptake values ranging from 0 to 9.29% adm. dose/kg, whereas normal tissue uptake values ranged from 0 to 1.63, respectively.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Carcinoma de Células Transicionales/terapia , Inmunoconjugados/uso terapéutico , Compuestos de Tecnecio/administración & dosificación , Neoplasias de la Vejiga Urinaria/terapia , Administración Intravesical , Carcinoma de Células Transicionales/metabolismo , Epitelio/metabolismo , Humanos , Valores de Referencia , Compuestos de Tecnecio/farmacocinética , Distribución Tisular , Neoplasias de la Vejiga Urinaria/metabolismoRESUMEN
The relationship between ribulose diphosphate carboxylase (3-phospho-d-glycerate carboxy-lyase [dimerizing], EC 4.1.1.39, formerly known as carboxydismutase) and protochlorophyllide holochrome of etiolated Phaseolus vulgaris leaves has been studied.A procedure for partially selective extraction of the two proteins was devised using tris-HCl buffer first without and then with Triton X-100. Ribulose diphosphate carboxylase was readily extracted from etiolated bean leaves without Triton X-100, and protochlorophyllide holochrome was extracted on the addition of Triton X-100. Optimal extraction conditions for protochlorophyllide holochrome have been found to be different for tissues of different ages.