A phase II trial of 10-ethyl-10-deaza-aminopterin, a novel antifolate, in patients with advanced and/or recurrent squamous cell carcinoma of the head and neck. The EORTC Head and Neck Cancer Cooperative Group.

Forty-seven patients with advanced and/or recurrent squamous cell carcinoma of the head and neck were treated with 10-ethyl-10-deaza-aminopterin (10-EdAM), a new analogue of methotrexate. The drug was given as a weekly i.v. bolus injection, starting at 80 mg/m2 with two dose increments of 10% if no toxicity was observed after two weeks. Only patients with tumors of the larynx, oral cavity, oropharynx and hypopharynx were included in the trial. Eighty-two percent of the patients had had prior surgery and/or radiotherapy. Forty-four patients were evaluable for response and toxicity. Five CR (12%) and five PR were obtained, yielding a response rate of 24% (CR+PR). The toxicity was similar to that usually seen with methotrexate; stomatitis and skin toxicity were rather pronounced. The data suggest that 10-EdAM has activity similar to that of methotrexate in patients with head and neck cancer.     

Cells of origin of crossed and uncrossed corticospinal fibers in the cat

Summary The cortical distribution of the cells of origin of the dorsolateral and the ventral corticospinal tracts was studied in cat. This was done by making subtotal spinal transections, which in different experiments spared different portions of one ventral or one lateral funiculus at C5–C7. One week later horseradish peroxidase (HRP) injections were made one segment caudal to the lesion and the cortical distribution of the HRP labeled neurons was studied.Thus, it was found that the dorsolateral corticospinal tract at C5–C7 is composed of crossed and uncrossed fibers in a ratio of about 10 1, while the ventral corticospinal tract, which contains much fewer cortical fibers, is composed of crossed and uncrossed fibers in a ratio of approximately 1 1. Further, the primary motor cortex (area 4) was found to contribute fibers to both the crossed and the uncrossed dorsolateral corticospinal tract as well as to both the crossed and the uncrossed ventral corticospinal tract. The primary somatosensory cortex (area 3a, 3b, 1–2, 5a, 5b) as well as the secondary somatosensory cortex (area 2 pre-insularis), on the other hand, were found to contribute fibers mainly to the crossed dorsolateral tract. Area 4 was found to display a further organization, such that it contains a medial and a lateral part, both of which contribute mainly fibers to the crossed dorsolateral tract, while the remainder of area 4 contributes fibers to the crossed and uncrossed dorsolateral as well as to the crossed and uncrossed ventral tracts.This study was in part supported by grant 13.46.15 of the FUNGO/ZWO (Dutch Organization for Fundamental Research in Medicine) and grant C.R.L. 79.4.337.6.INT. of the INSERM (Institut National de la Santé et de la Recherche Médicale)     

Genotyping of clinical methicillin-susceptible Staphylococcus aureus isolates in a Dutch teaching hospital

Methicillin-susceptible Staphylococcus aureus isolates, recovered from 204 patients in our hospital in a 22-month period, were characterized by pulsed-field gel electrophoresis. Among the multiple S. aureus types six clonal lineages dominated, comprising isolates from 158 patients. Despite the limited genetic variation, cross-transmission was made plausible only sporadically.     

Acute myeloid leukemia with t(6;9)(p23;q34) is associated with dysplasia and a high frequency of flt3 gene mutations

We report 12 cases of t(6;9)(p23;q34)-positive acute myeloid leukemia (AML), all classified using the criteria of the World Health Organization classification. There were 10 women and 2 men with a median age of 51 years (range, 20-76 years). Dysplasia was present in all cases (9 previously untreated), and basophilia was present in 6 (50%). Immunophenotypic studies showed that the blasts were positive for CD9, CD13, CD33, CD38, CD117, and HLA-DR in all cases assessed. CD34 was positive in 11 (92%) of 12, and terminal deoxynucleotidyl transferase was positive in 7 (64%) of 11 cases. The t(6;9) was the only cytogenetic abnormality detected in 7 cases (58%), and 5 cases had additional chromosomal abnormalities. Of 8 cases assessed, 7 (88%) had flt3 gene mutations. We conclude that t(6;9)-positive AML cases have distinctive morphologic features, an immunophenotype suggesting origin from an early hematopoietic progenitor cell, and a high frequency of flt3 gene mutations.     

Activation of the CD3/T cell receptor (TcR) complex or of protein kinase C potentiate adenylyl cyclase stimulation in a tumoral T cell line: involvement of two distinct intracellular pathways.

A monoclonal antibody (OKT3) directed against the T cell receptor (TcR)/CD3 molecular complex, as well as a protein kinase C (PKC) activator (phorbol 12-myristate 13-acetate, PMA) were added to a culture of tumoral Jurkat T cells, in order to precise the sequence of intracellular signals leading to T cell activation. The experiments were performed in the presence or in absence of various stimulators of adenylate cyclase (AC) such as forskolin (FK), cholera toxin (CT) or prostaglandin E2 (PGE2). OKT3 increased inositol phosphate (IP) production; in parallel, it induced a slight accumulation of cAMP. The effect was markedly potentiated in presence of FK or CT, and to a lesser extent in the presence of PGE2. FK stimulated adenylate cyclase of Jurkat cell membranes, but the effect was not potentiated by OKT3, suggesting that potentiation of cAMP accumulation requires intact cells and is not mediated by direct receptor coupling. On the other hand, elevated cAMP accumulation induced a negative feedback on IP production. The effect of OKT3 on cAMP was mimicked by A23187, a Ca2+ ionophore, and abolished in the absence of extracellular Ca2+. PMA had the same effect as OKT3 on basal or FK- and CT-induced accumulation of cAMP. In contrast, it inhibited the PGE2 effect on the cyclic nucleotide. After desensitization of PKC by pretreatment with a high concentration of PMA, the phorbol ester was no longer effective. Under those conditions, facilitation by OKT3 of FK-induced accumulation of cAMP was preserved, whereas potentiation by the monoclonal antibody of the PGE2 stimulation of AC was even enhanced. The data indicate that cAMP accumulation indirectly elicited by phospholipase C activation is, at least partly, mediated by IP-dependent Ca2+ mobilization, while PKC is preferentially effective as an inhibitor of PGE2 stimulation.     

CD101 expression by Langerhans cell histiocytosis cells

AIMS: Our objective was to study the expression of a recently identified cell surface molecule, CD101 and in Langerhans cell histiocytosis (LCH) patients as CD101 has been shown to be present on dendritic cells. We wanted to determine if CD101 expression could be helpful for the diagnosis of LCH in conjunction with other markers (CD1a, S100 protein), and could be predictive of the evolution and dissemination of the disease. METHODS AND RESULTS: The expression of CD101 was studied by immunohistochemical technique in 11 cases of Langerhans cell histiocytosis on frozen sections. The expression of CD101 was positive in nine cases, high in six cases and low in three cases. There was no expression in the other two cases. No correlation with the evolution, the localization or the dissemination of the disease could be evidenced. CONCLUSIONS: CD101 is a new phenotypic marker that might be useful in combination with other markers for the diagnosis of LCH. However, as the anti-CD101 antibody works only in frozen sections, its value is limited compared to anti-CD1a antibody.     

Interferon: a cytotoxic T lymphocyte differentiation signal

Human T cell clones which were able to proliferate in response to specific stimuli but could not kill even in the presence of lectins were found to acquire the specific lytic function when interferon alpha or gamma was added on day 1 of the 7-day restimulation culture. These results demonstrate that interferon may act as a cytotoxic T lymphocyte differentiation signal. This signal can be blocked by the monoclonal antibody LeoA1 which recognizes a 70-kDa cell surface structure, involved in cytotoxic T lymphocyte differentiation.     

Identification of mutations in TCOF1: use of molecular analysis in the pre- and postnatal diagnosis of Treacher Collins syndrome

Treacher Collins syndrome (TCS) is an autosomal dominant disorder of facial development, which results from mutations in TCOF1. TCS comprises conductive hearing loss, hypoplasia of the mandible and maxilla, downward sloping palpebral fissures and cleft palate. Although, there is usually a reasonable degree of bilateral symmetry, a high degree of both inter- and intrafamilial variability is characteristic of TCS. The wide variation in the clinical presentation of different patients, together with the fact that more than 60% of cases arise de novo, can complicate the diagnosis of mild cases and genetic counselling. In the current study, we describe how molecular techniques have been used to facilitate pre- and postnatal disease diagnoses in 13 TCS families.