Monoclonal antibody against sialylated Lewis(a) antigen

We isolated hybridoma cells, which secreted monoclonal antibody (MAb) 121 SLE, an IgM showing the following reactivities: (1) by immunodiffusion, MAb 121 SLE and MAb NS 19-9 (a monoclonal antibody directed against a sialylated Lewis(a) antigen called CA 19-9) showed an identical precipitin line with mucin preparation containing this CA 19-9; (2) by immunoradiometric assay, MAb 121 SLE totally inhibited fixation of radiolabelled MAb NS 19-9; (3) by immunoperoxidase, MAb 121 SLE stained the normal gastrointestinal mucosa of Le-positive individuals exclusively, and this staining disappeared after neuraminidase treatment, as observed using MAb NS 19-9. However, the pattern of the staining obtained with MAb 121 SLE differed slightly from that given by MAb 19-9 on the different positive areas of the gastrointestinal mucosae. These differences principally concerned the number of positive epithelial cells and the intensity of their staining; (4) moreover, antibodies against idiotype determinant of NS 19-9 antibody did not react with the antibody 121 SLE. We concluded that MAb 121 SLE is different from the MAb NS 19-9. However, both these antibodies were associated with the same molecular sialylated Lewis(a) structure.     

In vitro metabolism of ferroquine (SSR97193) in animal and human hepatic models and antimalarial activity of major metabolites on Plasmodium falciparum.

Ferroquine (SSR97193) has been shown to be a promising antimalarial, both on laboratory clones and on field isolates. So far, no resistance was documented in Plasmodium falciparum. In the present work, the metabolic pathway of ferroquine, based on experiments using animal and human hepatic models, is proposed. Ferroquine is metabolized mainly via an oxidative pathway into the major metabolite mono-N-demethyl ferroquine and then into di-N,N-demethyl ferroquine. Some other minor metabolic pathways were also identified. Cytochrome P450 isoforms 2C9, 2C19, and 3A4 and, possibly in some patients, isoform 2D6, are mainly involved in ferroquine oxidation. The metabolites were synthesized and tested against the 3D7 (chloroquine-sensitive) and W2 (chloroquine-resistant) P. falciparum strains. According to the results, the activity of the two main metabolites decreased compared with that of ferroquine; however, the activity of the mono-N-demethyl derivative is significantly higher than that of chloroquine on both strains, and the di-N-demethyl derivative remains more active than chloroquine on the chloroquine-resistant strain. These results further support the potential use of ferroquine against human malaria.     

Extra-intracranial shunts by venous grafts interposed on the carotid system

Patients with occlusive arterial diseases, tumors invading the vascular structures of the skull base or giant aneurysms may benefit from an EICB. Most of the time this can be achieved using a scalp artery. But in cases of a thrombotic ECA, excessively short or thin scalp branches or destruction of those by prior cranial surgery, an interposed venous graft is needed. In the author's series, which consists of 16 patients, the bypass was performed for ICA occlusive diseases in 5, before complete removal of cavernous sinus tumours in 4 and prior to cervical internal carotid ligation for giant aneurysms in 7. The grafts were always harvested from the internal saphenous vein. The proximal site of implantation was CCA (2 cases), ECA (6 cases), ICA (1 case), superior thyroid A (2 cases)--i.e. 11 long grafts--and the trunk of the occipital A--i.e. short grafts in 5 cases. In this series, there was no mortality and no morbidity related to revascularization. The early patency rate, checked with arteriography, was 62.5% (10 cases) and the late one 56.2% (9 cases). Causes of failure, partially related to technical difficulties in 2 cases, were almost always due to an insufficient extra-intracranial pressure gradient (4 cases). Excepted in one case, there was no correlation between patency and the use or not of anti-aggregant and/or heparin. Literature data are summarized and discussed. They all confirm the importance--besides the absence of technical errors--of a sufficient extra-intracranial gradient for obtaining a good patency rate.     

Epidermal growth factor receptor regulates normal urothelial regeneration

Members of the epidermal growth factor (EGF) family and their receptors are involved in many cellular processes, including proliferation, migration, and differentiation. We have previously reported that these growth factors are expressed and have specific regulatory functions in an organ-like culture model of normal human urothelial cells. Here, we used this model to investigate the involvement of EGF receptor (EGFR) in human urothelial regeneration. Three 4-mm-diameter damaged areas were made in confluent normal human urothelial cell cultures with a biopsy punch. Regeneration was measured, on fixed stained cultures, with an image analyzer, at 4, 24, and 48 hours after injury. Cell proliferation was assessed by 5-bromo-2-deoxyuridine incorporation. To identify EGF family factors potentially involved in the healing process, we studied the effect of these factors on damaged confluent cultures and the level of expression of mRNAs extracted from these cultures. EGFR inhibition of the proliferation and migration of urothelial cells was tested with (1). a specific tyrosine kinase inhibitor (AG1478) and (2). a blocking anti-EGFR antibody (LA22). Exogenously added amphiregulin, EGF, transforming growth factor-alpha and heparin-binding EGF (HB-EGF) stimulated urothelial regeneration. The damaged areas were repaired by regrowth within 48 hours. Both AG1478 and LA22 inhibited the repair (by 50% and 30%, respectively), as well as proliferation and migration. This regeneration was accompanied by increased HB-EGF mRNA expression in cultures of cells from four of six subjects, but no corresponding change in EGFR protein level was observed. These results indicate that the EGFR signaling pathway is involved in urothelial regeneration. Our data support an autocrine role of HB-EGF in this process and suggest that the EGFR pathway is a potential therapeutic target for modulating urothelial cell proliferation.     

High risk for unbalanced segregation of some reciprocal translocations: A large pedigree containing distal 4q trisomy from t(4;7)(q28;p22)

We report on a familial t(4;7)(q28;p22) with 2:2 adjacent‐1 unbalanced segregation producing duplication of 4q28→qter in multiple offspring. Within the large four‐generation pedigree, a carrier had a reproductive outcome that was approximately equal for 1) the balanced translocation, 2) normal chromosomes, and 3) viable 4q trisomy or pregnancy loss. The three individuals with chromosomal confirmation of trisomy 4q28→qter (comprising approximately 1.8% of the haploid autosomal length) had similar mental and developmental retardation, hypotonia, restricted speech, seizures, and facial anomalies but no cardiac, renal, or skeletal anomalies. It is suggested that these latter severe malformations, associated with the classic 4q2 to 3 group of anomalies, were from an imbalance outside 4q28→qter and were not necessarily related to the relatively large size of the trisomic segment. Multiple different chromosomes are reported to be rearranged with 4q in the production of distal 4q trisomy. The incidence of 4q rearrangement remains unexplained, but once it is present in a family, viability of a large trisomy in 4q seems to explain the number of affected individuals reported. © 2001 Wiley‐Liss, Inc.     

Autonomous histopathological regression of primary tumours associated with specific immune responses to cancer antigens

Spontaneous histopathological regression of cancer has been reported. The involvement of the immune system in such regression has been advocated, leading to the theory of immunological surveillance against cancer. A prediction of this theory is that common tumour antigens can be recognized upon repeated exposure by cell-mediated immunity, which leads to tumour regression and the subsequent appearance of tumour antigen-loss variants. However, no direct evidence has been provided in non-viral-induced experimental animal models of primary malignancy or in human primary cancer. This study examined two groups of melanoma patients where histopathological regression of the primary tumour was observed. Many of the 23 patients with multiple (> or =3) primary melanomas showed significant regression of their last melanoma (median 33%, mean 40) compared with matched melanomas from patients with a single primary melanoma (median 0%, mean 12) (p=0.0080), or compared with their first primary melanoma (p=0.0013). Regression was consistent with an 'immunization effect' seen in murine tumour transplantation studies, where inoculation with > or =3 asynchronous tumours induces transplantation rejection on subsequent challenge. A significant decrease in the expression of the melanoma common tumour antigen MART-1 in the last primary tumour from multiple melanoma patients (median 8%, mean 24) versus matched single melanoma patients (median 79%, mean 68) (p=0.0041) and in the last versus first tumour in multiple primary patients was found (p=0.0083). Metastases from 17 patients whose primary skin melanomas had completely regressed (occult primary melanoma) also showed significant MART-1 loss (median 0%, mean 11) compared with matched metastases from patients with non-regressing primary melanoma (median 51%, mean 50) (p=0.0013). MART-1 antigen-loss variants observed in the multiple primary and occult primary patients correlated with the presence of peripheral blood MART-1-specific cytotoxic T lymphocytes (CTLs) (p=0.03). No similar effects were observed with two other melanoma antigens, gp100 and CD63. Thus, in two groups of human melanoma patients, evidence is provided for histopathological tumour regression associated with cancer immune surveillance.     

Surgery of chagasic megacolon

Chagas' disease is an endemic clinical entity caused by Trypanosoma cruzi,a parasite that is transmitted to humans by the hematophagic Triatominae insects. It affects several million persons in Latin America, mostly in Brazil, Argentina, Chile, Paraguay, and Bolivia. Megacolon, the most common complication of intestinal trypanosomiasis, results in severe constipation, for which surgery is indicated. A variety of procedures have been proposed for the correction of this disabling condition including sigmoidectomy, abdominal rectosigmoidectomy, left colectomy, and subtotal colectomy. On long-term follow-up, however, these operations have proved to be inadequate in a significant number of cases, apparently due to preservation of the dyskinetic rectum which continues to act as a functional obstacle to the progression of the fecal bolus. On the other hand, pull-through operations, which include the removal of all or almost all of the dyskinetic rectum, or the exclusion of the rectum, as in the Duhamel-Haddad operation, have been demonstrated to be superior. The abdominoperineal endoanal pull-through resection with delayed colorectal anastomosis and the Duhamel-Haddad operation are the most accepted procedures in Brazil and other Latin American countries; their technical details are illustrated. Functional results are satisfactory. Anal continence is normal in the vast majority of cases and sexual disturbances are rare. Routine treatment of 2 main complications—fecaloma and volvulus of the sigmoid colon—are discussed.

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Resumen La enfermedad de Chagas es una entidad clínica de carácter endémico transmitida al ser humano por insectos triatomídeos. Afecta a varios millones de personas en América Latina, principalmente en Brasil, Argentina, Chile, Paraguay, y Bolivia. El megacolon es una de las complicaciones más comunes de esta enfermedad. La cirugia esta indicada en la gran mayoría de los casos y tiene como propósito principal curar el severo estreñimiento que afecta a la mayoría de los pacientes. Entre los procedimientos quirúrgicos que han sido propuestos, la sigmoidectomía, la rectosigmoidectomía abdominal, la colectomía izquierda, y la colectomía total han demostrado ser ineficaces, en un número significativo de casos, en el seguimiento a largo plazo, ciertamente porque en estos procedimientos se preserva el recto disquinético, el cual continúa actuando como un obstáculo funcional al avance del bolo fecal. Por el contrario, las operaciones de tipo pull-through han demostrado mayor efectividad, en virtud de que incluyen la resección de la totalidad o de la casi totalidad del recto disquinético, o su exclusión, como en la operación de Duhamel-Haddad. La resección abdominoperineal con pull-through endoanal y la operación de Duhamel-Haddad son los 2 procedimientos de preferencia en Brasil y en las naciones latinoamericanas. Se ilustran sus detalles técnicos. La continencia anal queda normal en la mayoría de los casos operados y la disfunción sexual es rara. Se discute el tratamiento rutinario de otras 2 complicaciones—el fecaloma y el vólvulos del sigmoide.

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Résumé La maladie de Chagas est une entité clinique endémique provoquée par le Trypanosome cruzi, parasite transmis aux hommes par les insectes Triatominae hématophagi. Elle affecte plusieurs millions d'individus en Amérique Latine, surtout au Brésil, en Argentine, au Chile, au Paraguay, et au Bolivie. Le mégacôlon, complication la plus courante de la trypanosomiase intestinale se traduit par une constipation grave pour laquelle la chirurgie est indiquée. Différents procédés ont été proposés pour corriger cet état invalidant comprenant sigmoïdectomie, rectosigmoïdectomie, colectomie gauche, et colectomie subtotale. Un bon nombre de ces interventions se sont avérées inadaptées dans les suites à long terme ce qui est apparemment dû à la conservation du rectum dyskinétique qui continue à agir comme obstacle fonctionnel à la progression des selles. Par ailleurs, les interventions par retournement qui comprennent l'ablation soit totale soit subtotale du rectum dyskinétique ou son exclusion comme dans l'intervention de Duhamel-Haddad, se sont avérées meilleures. La résection abdominopérinéale par retournement avec anastomose colorectale retardée et l'intervention de Duhamel-Haddad sont les processus les plus couramment employés au Brésil et dans les autres pays d'Amérique Latine; les détails techniques sont illustrés. Les résultats fonctionnels sont satisfaisants. La continence est normale dans la plus grande majorité des cas et les troubles sexuels sont rares. Le traitement systématique des 2 complications principales, fécalome et volvulus du côlon sigmoïde, sont discutées.

     

Effect of pre-conceptional external or internal irradiation of N5 male mice and the risk of leukemia in their offspring

Male mice of the N5 strain were exposed to a unique external X-ray dose of 500 cGy, or to i.p. injections of tritiated water (HTO) over a 30 day period, which resulted in an estimated total internal exposure of 150 cGy. The paternal X-ray irradiation resulted in a marginally significant (P = 0.07) doubling of the leukemia/lymphoma rate in the offspring, over a 1 year observation period. The constitutive gene expression of granulocyte-macrophage colony stimulating factor (GM-CSF) and tumour necrosis factor (TNF) (two cytokines associated with hematopoiesis and immune response) spontaneously diminished between the ages of 6 months and 12 months in the bone marrows and in the spleens of these mice, and paternal X-ray exposure influenced the statistical significance of this diminution. Male exposure to HTO resulted in a statistically significant several-fold increase of leukemia incidence among the young offspring. However this increase tended to diminish as older mice were observed, and was no longer significant at 1 year of age. The overall leukemia incidence in the offspring of the HTO-exposed fathers was significantly dependent on the maturation stage of the sperm-forming cells during the HTO exposure, which suggests an influence of such an exposure.