Endotelina-1, proteína C reactiva ultrasensible y actividad antioxidante en pacientes con hipotiroidismo subclínico y en eutiroideos con autoinmunidad tiroidea. Efectos del tratamiento con levotiroxina / Endothelin-1, high sensitivity C reactive protein and antioxidant activity in subclinical hypothyroid patients. Effects of levothyroxine treatment

RESUMEN La Endotelina-1 (ET1) y Proteína C Reactiva ultrasensible (PCRus) como marcadores de disfunción endotelial (DE) e inflamación vascular en hipotiroidismo subclínico (HS) han mostrado resultados controvertidos. El rol del estrés oxidativo y defensa antioxidante (TRAP) es motivo de discusión. Objetivos Establecer si el HS y la autoinmunidad tiroidea (AIT), excluyendo otros factores de riesgo cardiovascular, pueden causar DE e inflamación vascular, evaluadas a través de ET1 y PCRus, respectivamente. Establecer si TRAP juega algún rol. Evaluar cambios en ET1 y PCRus luego del tratamiento con levotiroxina (LT4). Material y métodos Se evaluaron prospectivamente 70 pacientes divididos en 3 grupos: HS: 41 pacientes (T4 normal,TSH >4,2 y <10 mUI/L), AIT: 10 pacientes eutiroideos (TSH <4,2 mUI/L) con aTPO y/o aTg (+) y Control: 19 pacientes eutiroideos sin AIT. Se excluyeron otros factores de riesgo cardiovascular. Se midió basalmente ET1, PCRus y TRAP plasmáticos, y en HS bajo LT4 (n = 24): ET1 y PCRus. Resultados No hubo diferencias significativas en edad, IMC, perfil lipídico y TRAP. ET1 y PCRus fueron significativamente mayores en pacientes con HS (media ± DS 1,77 ± 0,85 pg/ml y 1,5 ± 0,6 mg/l vs. controles (0,8 ± 0,3 pg/ml y 0,5 ± 0,2 mg/l) p <0,0001 y <0,008 respectivamente. Del mismo modo en AIT (1,4 ± 0.4 pg/ml y 2,3 ± 1,3 mg/l) vs controles p <0,0001 y <0,034, respectivamente. La TSH fue mayor en el grupo AIT vs. Control 2,57 ± 0,88 vs. 1,64 ± 0,5 mUI/L; p = 0,002. En HS bajo LT4 (8,7 ± 3,8 meses) se observó descenso de ET1 (p <0,001). ET1 correlacionó con TSH (r = 0,5 p <0,0001). El punto de corte de ET1 mediante curva ROC fue 1,32 pg/ml (Sensibilidad 81,6%-Especificidad 75%). Conclusiones ET1 y PCRus resultaron marcadores útiles para evaluar DE e inflamación vascular asociadas a HS. La defensa antioxidante no ejercería un rol en estos mecanismos. El tratamiento con LT4 produjo una significativa caída de ET1, pudiendo necesitarse un período más largo de eutiroidismo para normalizarla. En AIT, niveles de TSH >2,5 mUI/L podrían sugerir un mínimo grado de hipotiroidismo justificando la elevación en ET1 y PCR, sin descartar el rol de la AIT "per se".

ABSTRACT The measurement of endothelin-1 (ET1) and high sensitivity C-reactive protein (hsCRP) as markers of endothelial dysfunction (ED) and vascular inflammation in subclinical hypothyroidism (SH) has shown controversial results. The role of oxidative stress and antioxidant defense (TRAP) is a matter of discussion. Objectives To establish if SH and thyroid autoimmunity (TAI), excluding other cardiovascular risk factors, may cause ED and vascular inflammation, evaluated through the measurement of ET1 and hsCRP respectively. To determine if TRAP could have some role. Additionally, changes in these parameters after treatment with levothyroxine (LT4) will be evaluated. Material and methods: 70 patients were prospectively evaluated. They were classified into: SH Group: 41 patients (normal T4, TSH> 4.2 and <10 mIU/L), TAI Group: 10 euthyroid patients (TSH <4.2 mUI/L) with positive aTPO and/or aTg and Control Group: 19 euthyroid patients without TAI. Other cardiovascular risk factors were excluded in patients and controls. Plasma ET1, hsCRP and TRAP were measured basally, and ET1 and hsCRP under LT4 therapy in the HS Group. Results There were no significant differences between the 3 groups in age, BMI, lipids and TRAP. ET1 and hsCRP were significantly higher in patients with SH (mean ± SD 1.77 ± 0.85 pg/ml and 1.5 ± 0.6 mg/l) vs. controls (0.8 ± 0.3 pg/ml y 0.5 ± 0.2 mg/l) p <0.0001 y <0.008 respectively. Similarly, in TAI patients (1.4 ± 0.4 pg/ml y 2.3 ± 1.3 mg/l) vs controls, p <0.0001 and <0.034, respectively. TSH was higher in the TAI patients versus control group (2.5 ± 0.88 versus 1.64 ± 0.5 mIU/L, p = 0.002). Twenty-four patients with SH showed a significant decrease in ET1 (p <0.001) under treatment with LT4 (8.7 ± 3.8 months). ET1 had a highly significant correlation (p <0.0001) with TSH (r = 0.5). The cut-off level of ET1 established by ROC curve was 1.32 pg/ml (Sensitivity 81.6%-Specificity 75%). Conclusions ET1 and hsCRP were useful markers to evaluate ED and vascular inflammation associated with SH. There were no differences in TRAP levels between patients and controls, so it does not appear that oxidative stress would have played any role. Treatment with LT4 produced a significant drop in ET1. Probably, a longer period of euthyroidism might be necessary to normalize ET1 levels. In TAI Group, TSH levels >2.5 mUI/L could suggest a "minimal degree" of hypothyroidism justifying the elevation in ET1 and hs CRP. The role of the TAI "per se" couldn't be completely ruled out.

The treatment with an anti-glycosaminoglycan antibody reduces aortic oxidative stress in a rabbit model of atherosclerosis.

Retained low-density lipoproteins (LDL) by arterial glycosaminoglycans (GAG) are more susceptible to reactive oxygen species-mediated oxidation, contributing to oxidative stress and atherosclerosis. Recently, we reported the properties of the chimeric mouse/human monoclonal antibody chP3R99-LALA to bind sulfated GAG, to inhibit LDL-chondroitin sulfate binding, and to avoid LDL oxidation in vitro. Here, we hypothesized that chP3R99-LALA treatment might reduce aortic oxidative stress in a therapeutic setting. Redox biomarkers and serum lipids were determined by spectrophotometric methods. Subcutaneous administration of five doses (100 µg) of chP3R99-LALA, after Lipofundin administration (2 mL/kg/day, i.v.) during 8 days, reduced atherosclerotic lesion development, which was not associated with a serum lipid modulation. In contrast, the treatment with chP3R99-LALA reduced (p < 0.05) malondialdehyde and protein oxidation, induced a restoration of reduced glutathione level, of the superoxide dismutase and catalase activities and of endothelial nitric oxide level. Thus, the antiatherogenic effect of chP3R99-LALA treatment seems to be associated with a reduction of aortic oxidative stress. These results contribute in understanding the molecular mechanisms associated with chP3R99-LALA atheroprotection and support the use of anti-GAG antibody-based immunotherapy as a potential tool to treat the atherosclerosis.

Carcinoma en quiste tirogloso / Carcinoma in thyroglosal duct cyst

El carcinoma diferenciado de tiroides en quiste tirogloso (CaQT) es una rara entidad. En diferentes series de pacientes operados por quistes tiroglosos su incidencia fue del 0.7 al 1.07%. Luego de la extirpación del quiste por el procedimiento de Sistrunk, no hay consenso sobre la indicación de tiroidectomía total, radioablación y/o terapéutica supresiva con levotiroxina. El objetivo del Departamento de tiroides de SAEM, fue evaluar: formas de presentación, evolución clínica, métodos diagnósticos de utilidad y tratamiento para consensuar futuras conductas. Material y Métodos: Estudio multicéntrico, retrospectivo en 22 pacientes entre 10 a 69 años, 15 mujeres y 7 varones. Resultados: El tamaño de los quistes osciló entre 1 y 8 cm (Mediana= 3.0 cm, Χ ± DS= 3.7 ± 2.2 cm). La mitad de los pacientes presentó crecimiento del quiste en los 6 meses previos a la cirugía. La punción resultó sospechosa en 2/5 quistes y positiva en uno. La ecografía tiroidea evidenció nódulos en 4/13 casos (30%). Se realizó tiroidectomía en 17/22 pacientes (total: 15 y subtotal: 2). La histología del CaQT demostró carcinoma papilar en 21 y carcinoma folicular en uno. Hubo coexistencia de cáncer intratiroideo en el 23.5% de los casos, ninguno multicéntrico. Dos pacientes presentaron metástasis ganglionares y otro tuvo compromiso muscular (ninguno de ellos coexistió con cáncer intratiroideo). Se radioablacionó a 13 pacientes. En 9/11 pacientes la tiroglobulina permaneció indetectable durante el seguimiento (1 a 14 años). Conclusiones: 1) Realizar ecografía de cuello y punción ecoguiada a todo paciente con quiste tirogloso. 2) En caso de CaQT combinar simultáneamente tiroidectomía total y procedimiento de Sistrunk. 3) Evaluar radioablación complementaria y tratamiento supresivo con levotiroxina en cada caso. 4) Efectuar el seguimiento tal como en los carcinomas ortotópicos.

Differentiated thyroid carcinoma (DTC) in thyroglosal duct cyst (TGDC) is rare, ranging from 0.7 to 1.07% in different series. After the surgery of choice (Sistrunk procedure) the other alternative treatments such as thyroidectomy (Tx), radioiodine and L-T4 therapy are controversial. OBJECTIVE: to evaluate several and controversial aspects in the largest series of DTC in TGDC reported in the literature. Subjects and methods: retrospective multicentric study: n= 22, aged 10-69 yrs. (15 females and 7 men) who underwent the Sistrunk procedure for TGDC. Results: none of the TGDC was less than 1 cm (median 3.0 cm, Χ±SD= 3.7 ± 2.2cm). In half of them there was an increased cystic size in the last 6 months before surgery. Cyst FNA was suspicious in 2/5 and positive in one, whereas the histological diagnosis of the operated TGCD was papillary cancer in 21 and 1 follicular carcinoma. Thyroid ultrasound (US) (n=13) showed nodules in 30% of the cases. Tx was performed in 17/22 (total: 15, subtotal: 2). Thyroid DTC coexisted in 4/17 (23.5%), and was unilateral in all of them. Lymph node metastases were present in 2 adults and muscle involvement was found in the 10-year old girl. None of these 3 patients had overt thyroid lesions. 131-I therapy was performed in 10 patients. In 9 out of 11 subjects Tg remained undetectable during follow-up (1-14yrs.). Persistent high Tg was present in one case without thyroid DTC. Conclusions: 1) Ultrasonography and FNAB should be performed to every patient with thyroglossal duct cyst 2) In case of TGDC, total Tx and Sistrunk's procedure should be simultaneously combined 3) 131-I therapy and L-T4 suppressive treatment should be evaluated in every case 4) Follow-up as in the DTC.

Combined therapeutic effect of a monoclonal anti-idiotype tumor vaccine against NeuGc-containing gangliosides with chemotherapy in a breast carcinoma model.

Anti-idiotypic monoclonal antibodies (mAb) have been evaluated for actively induced immunotherapy with encouraging results. However, rational combination of cancer vaccines with chemotherapy may improve the therapeutic efficacy of these two approaches used separately. The main objective of this study was to evaluate the antitumor effect of the co-administration of 1E10 (Racotumomab), a monoclonal anti-idiotype tumor vaccine against an IgM mAb, named P3 that reacts specifically with NeuGc-containing gangliosides and low-dose Cyclophosphamide in a mammary carcinoma model. F3II tumor-bearing mice were immunized subcutaneously with 100 microg of 1E10 mAb in Alum or with 150 mg/m(2) of Cyclophosphamide intravenously 7 days after the tumor inoculation. While a limited antitumor effect was induced by a single 1E10 mAb immunization; its co-administration with low-dose Cyclophosphamide reduced significantly the F3II mammary carcinoma growth. That response was comparable with the co-administration of the standard high-dose chemotherapy for breast cancer based on 60 mg/m(2) of Doxorubicin and 600 mg/m(2) of Cyclophosphamide, without toxicity signs. Combinatorial chemo-immunotherapy promoted the CD8(+) lymphocytes tumor infiltration and enhanced tumor apoptosis. Furthermore, 1E10 mAb immunization potentiated the antiangiogenic effect of low-dose Cyclophosphamide. Additionally, splenic myeloid cells Gr1(+)/CD11b(+) associated with a suppressor phenotype were significantly reduced in F3II tumor-bearing mice immunized with 1E10 mAb alone or in combination with low-dose Cyclophosphamide. This data may provide a rational for chemo-immunotherapy combinations with potential medical implications in breast cancer.

Anti-ganglioside anti-idiotypic monoclonal antibody-based cancer vaccine induces apoptosis and antiangiogenic effect in a metastatic lung carcinoma.

Anti-idiotype monoclonal antibody (mAb) 1E10 was generated by immunizing BALB/c mice with an Ab1 mAb which recognizes NeuGc-containing gangliosides, sulfatides and some tumor antigens. 1E10 mAb induces therapeutic effects in a primary breast carcinoma and a melanoma model. However, the tumor immunity mechanisms have not been elucidated. Here we show that aluminum hydroxide-precipitated 1E10 mAb immunization induced anti-metastatic effect in the 3LL-D122 Lewis Lung carcinoma, a poorly immunogenic and highly metastatic model in C57BL/6 mice. The therapeutic effect was associated to the increment of T cells infiltrating metastases, the reduction of new blood vessels formation and the increase of apoptotic tumor cells in lung nodules. Interestingly, active immunization does not induce measurable antibodies to the 1E10 mAb, the NeuGc-GM3 or tumor cells, which may suggest a different mechanism which has to be elucidated. These findings may support the relevance of this target for cancer biotherapy.

Immunogenetic analysis of variable regions encoding AB1 and gamma-type AB2 antibodies from the NeuGc-containing ganglioside family.

The variable regions from P3, a murine monoclonal antibody (MAb) against NeuGc-containing gangliosides, and two anti-idiotype MAbs directed to P3 MAb were cloned and sequenced. Comparisons with previously reported sequences showed that P3 is a germline antibody encoded by genes from the V(H)Q52 and V(kappa)19 families. Analysis of nucleotides at the heavy chain CDR3 (H-CDR3) showed the presence of an extensive 3' N region that contains almost 50% of the nucleotides of this CDR. In addition, amino acid sequence analysis of the H-CDRs of this MAb revealed the presence of three arginines, two of which are present in the H-CDR3, that could be involved in the interaction of P3 MAb with its electronegative epitope on gangliosides. Anti-idiotype 1E10, which seems to define a "regulatory" idiotope on P3 MAb (it induces Id+ Ab3), represents a germline Ab2 that belongs to the V(H)J558 and V(kappa)10 gene families. By contrary, the anti-idiotype 3B11 is an extensively mutated antibody that belongs to the V(H)3660 and V(kappa)4/5 gene families, defining a "private" idiotope on P3 MAb. Even when different V genes contribute to the variable regions of 1E10 and 3B11 MAbs, they share an acidic motif E/D-D-Y/D-Y-D in H-CDR3, suggesting that both Ab2s recognize paratope positive residues on the Ab1. Therefore, complementary electrostatic interactions involving H-CDR3 from both Ab1 and Ab2, might provide a clue to understand the molecular basis for the generation of gamma-type anti-idiotype antibodies to V regions recognizing glycolylated ganglioside antigens.

[Pilot study with the monoclonal antibody IOR-C5 as a potential agent of radioimmunoscintigraphy in colorectal cancer]. / Ensayo piloto con el anticuerpo monoclonal ior-C5 como agente potencial de la inmunocentelleografía del cáncer colorrectal.

UNLABELLED: IOR C-5 is a G1 immunoglobulin type intact murine monoclonal antibody (MAb) that was developed in the Center of Molecular Immunology in Havana City, Cuba. In immunohistochemical studies, this demonstrated a significant affinity for the epithelial tissues so that it was used in a pilot clinical study to perform a radioimmunoscintigraphy of the colorectal primary tumors and their locoregional recurrences. It was labeled with 99mTc using the Schwarz method, with a > 95% performance. Planar images of the chest, abdomen and pelvis were performed at 10 minutes, 4-6 hours and 18-24 hours post-injection in the anterior and posterior projections and the SPECT was performed 4-6 hours and 18-24 hours post-injection of 1.85 GBq 99mTC. This study has aimed to verify in vivo the capacity of ior-C5 MAb to accumulate in the malignant colorectal lesions. ior-C5 accumulated in 5 out of the 7 patients who were studied and who were suffering from colorectal cancer or in whom there was suspicion of recurrence. There was a negative case of primary tumors, which was an adenocarcinoma in situ in a tubular-papillary adenoma. The second case with a negative radioimmunoscintigraphy was a true negative case. CONCLUSIONS: It can be concluded that even though the number of patients is quite low, ior-C5 fulfilled the expectations of recognizing the epitope expressed in colorectal tumors in an in vivo human environment.

A mouse IgG1 monoclonal antibody specific for N-glycolyl GM3 ganglioside recognized breast and melanoma tumors.

14F7 murine monoclonal antibody (MAb) is an IgG1 immunoglobulin that is generated by immunizing Balb/c mice with GM3(NeuGc) ganglioside hydrophobically conjugated with human very-low-density lipoproteins and in the presence of Freund's adjuvants. 14F7 MAb binds specifically to GM3(NeuGc), whereas neither N-glycolyl or N-acetyl gangliosides, nor a sulfated glycolipid, are recognized as assessed by enzyme-linked immunosorbent assay or immunostaining on thin layer chromatograms. Immunohistochemical studies in fresh tumor tissues showed that 14F7 MAb strongly recognized in antigen expressed in human breast and melanoma tumors.

Antitumor properties of an anti-idiotypic monoclonal antibody in relation to N-glycolyl-containing gangliosides.

We examined the antitumor effects of 1E10 monoclonal antibody, an anti-idiotypic IgG to an IgM monoclonal antibody, named P3, that reacts specifically with N-glycolyl-containing gangliosides and also recognizes antigens in human breast and melanoma tumors. Two murine tumor cell lines positive for the P3 antibody, F3II mammary carcinoma (BALB/c) and B16 melanoma (C57BL/6), were employed. In BALB/c mice, vaccination with several i.p. doses at 14-day intervals of 50 microgram of 1E10 coupled to keyhole limpet hemocyanin in Freund's adjuvant, significantly reduced s.c. tumor growth of F3II carcinoma cells and the number of spontaneous lung metastases. Also, the effect of 1E10 as a biological response modifier on tumor lung colonization was evaluated in C57BL/6 mice injected i.v. with B16 melanoma cells. Interestingly, i.v. administration of 10 microgram of uncoupled 1E10 antibody, 10-14 days after inoculation of B16 cells, dramatically reduced the number of experimental metastases in comparison with lungs from mice treated with an irrelevant IgG. The present data suggest that this 'non-internal image' anti-idiotypic monoclonal antibody may activate more than one mechanism of antitumor response against melanoma and mammary tumor cells.

Syngeneic anti-idiotypic monoclonal antibodies to an anti-NeuGc-containing ganglioside monoclonal antibody.

An IgM monoclonal antibody (MAb), named P3, has the characteristic to react specifically with a broad battery of N-glycolyl containing-gangliosides and with antigens expressed on breast tumors. When this MAb was administered alone in syngeneic mice, an specific IgG anti-idiotypic antibody (Ab2) response was induced, this Ab2 response was increased when P3 MAb was injected coupled to a carrier protein and in the presence of Freund's adjuvant. Spleen cells from these mice were used in somatic-cell hybridization experiments, using the murine myeloma cell line P3-X63-Ag8.653 as fusion partner. Five Ab2 MAbs specific to P3 MAb were selected. These IgG1 Ab2 MAbs were able to block the binding of P3 MAb to GM3(NeuGc) ganglioside and to a human breast carcinoma cell line. Cross-blocking experiments demonstrated that these Ab2 MAbs are recognizing the same or very close sites on the Abl MAb. The five Ab2 MAbs were injected into syngeneic mice and four of them produced strong anti-anti-idiotypic antibody (Ab3) response. While these Ab2 MAbs were unable to generate Ab3 antibodies with the same antigenic specificity than P3 MAb, three of them induced antibodies bearing P3 MAb idiotopes (Ag-Id+ Ab3). These results demonstrated that these Ab2 MAbs are not "internal image" antibodies, but they could define "regulatory idiotopes."

Generation of a murine monoclonal antibody specific for N-glycolylneuraminic acid-containing gangliosides that also recognizes sulfated glycolipids.

The P3 murine monoclonal antibody (MAb) was generated by immunizing BALB/c mice with NeuGcGM3 included into liposomes. The specificity of this MAb was defined by an enzyme-linked immunosorbent assay and immunostaining on thin-layer chromatograms. P3 MAb binds to NeuGc-containing gangliosides and was shown also to react with sulfated glycolipids. A preliminary immunohistochemical study showed that the P3 MAb was able to recognize antigens expressed in human breast tumors.

T cell-independent B cell response to self-monosialogangliosides: primary response monoclonal antibodies.

Purified GM1 and GM2 gangliosides incorporated into liposomes were injected subcutaneously in BALB/c mice every 3-4 days after pretreatment of the animals with low-dose cyclophosphamide. Serum samples were collected at different intervals and tests by ELISA for the presence of anti-ganglioside antibodies. Four doses (50 micrograms each) were sufficient to raise a measurable primary type of response to GM1, while nine doses were required to obtain measurable IgM antibody titers to GM2. Three monoclonal antibodies (MAbs) wer generated by fusing splenocytes with mouse myeloma cells. The specificity of MAbs was determined by ELISA and HPTLC-immunostaining using a panel of purified glycolipids. The MAb designated E1 showed a high degree of specificity because it reacted only with N-acetyl GM2. Monoclonal antibody A3 reacted predominantly with GM2 and GM1, but also reacted moderately with the GM3 ganglioside. The epitope recognized by this MAb is suggested to be the trisaccharide sequence GalNAc beta 1-4(NeuAc alpha 2-3)Gal. The third MAb (F6) reacted strongly with GM1 but a weak reactivity was also observed with GD1b as well as with asialo-GM1, indicating that the terminal tetrasaccharide Gal beta 1-3GalNAc beta 1-4(NeuAc alpha 2-3)Gal- structure is probably involved in antigenic recognition. Formalin-fixed and paraffin-embedded tissue sections were stained with the E1 and A3 MAbs, using the avidin-biotin complex (ABC) technique. Strong immunoreactivity for E1 appeared in the tumor cells of five primary lung carcinomas and in five malignant melanomas. No immunoreactivity was demonstrated in the parenchyma of a lung without malignancy, or in a metastasis from a colon carcinoma.

Antigen-specific primary immune response of human B-lymphocytes after in vitro immunization with GM3 ganglioside.

In vitro immunization of human B-lymphocytes was performed with liposomes containing the monosialoganglioside GM3, with or without either complete tetanus toxoid or a synthetic T helper epitope derived from tetanus toxin (determinant 830-843). The immunized B-cells were Epstein-Barr virus transformed and the human anti-ganglioside antibody response was evaluated using an indirect ELISA against different mono- and disialogangliosides. Clones producing antigen-specific human antibodies of the IgM isotype against the ganglioside GM3 used as the immunogen were selected and one clone, IM-11, was further characterized. In addition, a method of positive selection using GM3-coated magnetic beads has been developed which allowed us to rescue unstable clones. The binding of the human antibody IM-11 to a large panel of glycosphingolipids separated on thin-layer plates was studied. The human MAb IM-11 was found to bind strongly to NeuAcGM3, IV3 NeuAcnLc4 and sulfate containing glycosphingolipids and weakly to NeuGcGM3. Immunohistological staining of melanoma and breast cancer biopsy sections showed a selective reactivity of IM-11 with tumor cells which varied among different tumors.

Characterization of the colorectal antigen IOR-C2.

A colorectal antigen (IOR-C2) was characterized by a monoclonal antibody produced against the colon cancer cell line SW1116. By immunohistochemical staining the antigen was abundant and strongly expressed in epithelium of normal colon whereas colorectal carcinomas showed a more variable and heterogenous reactivity to the antibody (IOR-C2). Radioimmunoprecipitates of SW1116 cell homogenates showed a 160-200 kD band in SDS gels. Physicochemical characterization indicate that at least two IOR-C2 reactive sites are present on the antigen tested and that it is mainly an 0-linked glycoprotein carbohydrate chain which can also be N-linked to the protein. The expression of IOR-C2 mimics that of the colon associated antigen (CAA) and NCC-CO-450 antigen but is distinct from these with regard to its expression in carcinomas as well as its physicochemical characteristics.

Colon cancer associated antigen expresion on normal and neoplastic human tissues detected by IORC2: a novel monoclonal antibody / Expresión en tejidos humanos normales y tumorales del antígeno tumor asociado a cáncer de colon reconocido por el anticuerpo monoclonal IORC2

Inmunizando con la linea del cáncer del colon SW1116 (pobremente diferenciado), se obtuvo el anticuerpo monoclonal IORC2 empleando la técnica convencional de generación de hibridomas. El anticuerpo monoclonal IORC2 muestra un reconocimiento preferencial por el tejido epitelial en cortes fijados e incluidos en parafina, según se evidencia, empleando el sistema de detección avidina-peroxidasa-complejo (Amersham, U.K.). Se observa una reacción intensa en las lineas de cáncer del colon SW1116 y en los tumores derivados del epitelio glandular, especialmente los adenocarcinomas del colon y la mucosa normal del colon. También se observa reacción en un bajo por ciento de células del intestino delgado y del epitelio bronquial. No hubo reacción en los tejidos de origen nervioso, muscular y hematopoyético. Las aplicaciones potenciales del anticuerpo monoclonal IORC2 en el manejo del cáncer colorrectal humano se discuten

Toxic effects of interleukin-2-activated lymphocytes on vascular endothelial cells.

IL-2-activated lymphocytes (LAK cells) show increased adherence to, and killing of, human vascular endothelial cells compared to resting lymphocytes. In the present work, we have found that supernatants from LAK cell cultures also are toxic to human umbilical vein endothelial cells (HUVEC) when tested for 48 h in a neutral red uptake assay. Recombinant TNF-alpha and IFN-gamma at high concentrations are also toxic under the same test conditions, and TNF-alpha was directly detected in LAK cell supernatants. An inconsistent inhibition of toxicity was found with anti-TNF-alpha whereas anti IFN-gamma antibodies had a partial inhibitory effect. The susceptibility of HUVEC to cellular killing by LAK cells could be up- and down-regulated with insulin-like growth factor I and IFN-gamma, respectively. It is concluded that damage to vascular endothelium during high dose IL-2 treatments may be partially related to an excessive production of lymphokines such as IFN-gamma and TNF-alpha. IFN-gamma may, in addition, be protective for HUVEC during cellular interactions with LAK cells.

Estudio comparartivo del proceso de purificación de anticuerpos monoclonales mediante cromatografía de adsorción en hidroxiapatita / Comparative study of the purification of monoclonal antibodies using hydroxiapatite absortion chromatography

En el presente trabajo se compara la purificación de anticuerpos monoclonales de ratón de diferentes clases y subclases (IgG1, IgG2 e IgM) por cromatografía de adsorción en hidroxiapatita (BioRad) y en hidroxiapatita-Ultrogel (LKB). Se analizaron los factores capacidad de adsorción, rendimiento, tiempo de corrida (velocidad de flujo), reciclaje y capacidad de enlazamiento específicos de los anticuerpos obtenidos inmediatamente después de la purificación y posterior a su almacenamiento. Se concluye que la cromatografía de adsorción en hidroxiapatita, y en específico, luego de que esta sustancia acoplada a un soporte adecuado (HA Ultrogel), constituye un método fácil, sencillo, rápido y eficiente para la purificación de anticuerpos monoclonales