Conserved RARE localization in amphioxus Hox clusters and implications for Hox code evolution in the vertebrate neural crest.

The Hox code in the neural crest cells plays an important role in the development of the complex craniofacial structures that are characteristic of vertebrates. Previously, 3' AmphiHox1 flanking region has been shown to drive gene expression in neural tubes and neural crest cells in a retinoic acid (RA)-dependent manner. In the present study, we found that the DR5-type RA response elements located at the 3' AmphiHox1 flanking region of Branchiostoma floridae are necessary and sufficient to express reporter genes in both the neural tube and neural crest cells of chick embryos, specifically at the post-otic level. The DR5 at the 3' flanking region of chick Hoxb1 is also capable of driving the same expression in chick embryos. We found that AmphiHox3 possesses a DR5-type RARE in its 5' flanking region, and this drives an expression pattern similar to the RARE element found in the 3' flanking region of AmphiHox1. Therefore, the location of these DR5-type RAREs is conserved in amphioxus and vertebrate Hox clusters. Our findings demonstrate that conserved RAREs mediate RA-dependent regulation of Hox genes in amphioxus and vertebrates, and in vertebrates this drives expression of Hox genes in both neural crest and neural tube. This suggests that Hox expression in vertebrate neural crest cells has evolved via the co-option of a pre-existing regulatory pathway that primitively regulated neural tube (and possibly epidermal) Hox expression.     

Synergistic effect of interleukin-2 and a vaccine of irradiated melanoma cells transfected to secrete staphylococcal enterotoxin A

We have previously reported that immunization of mice with melanoma cells transfected to secrete the superantigen, Staphylococcal enterotoxin A (SEA), increased the production of antibodies to the B700 melanoma antigen, stimulated the production of endogenous interleukin 2 (IL-2), activated the expression of CD4, CD8 and CD25 T cell markers and enhanced NK cell activity. Now we show that immunization of mice with a vaccine of irradiated sea-transfected melanoma cells coupled with IL-2 therapy was even more effective in inhibiting the growth of primary melanoma tumors and the development of lung metastases than was the irradiated melanoma cell vaccine alone or IL-2 alone. The morphological and immunological effectiveness of the therapy was dose-dependent on IL-2.     

The seroepidemiology of human T-lymphotropic viruses: types I and II in Europe: a prospective study of pregnant women

BACKGROUND: Up to 20 million persons are infected with the human retroviruses human T-lymphotropic virus (HTLV)-I and HTLV-II globally. Most data on the seroprevalence of HTLV-I and HTLV-II in Europe are from studies of low-risk blood donors or high-risk injection drug users (IDUs). Little is known about the general population. METHODS: A prospective anonymous study of HTLV-I and HTLV-II seroprevalence among 234,078 pregnant women in Belgium, France, Germany, Italy, Portugal, Spain, and the United Kingdom was conducted. Maternal antibody status was determined by standard methods using sera obtained for routine antenatal infection screens or eluted from infant heel prick dried blood spots obtained for routine neonatal metabolic screens. RESULTS: Anti-HTLV-I/II antibodies were detected and confirmed in 96 pregnant women (4.4 per 10,000, 95% confidence interval [CI]: 3.5-5.2). Of these, 73 were anti-HTLV-I, 17 were anti-HTLV-II, and 6 were specifically anti-HTLV but untyped. The seroprevalence ranged from 0.7 per 10,000 in Germany to 11.5 per 10,000 in France. CONCLUSIONS: Pregnant women better reflect the general population than blood donors or IDUs. The seroprevalence of HTLV-I and HTLV-II in Western Europe is 6-fold higher among pregnant women (4.4 per 10,000) than among blood donors (0.07 per 10,000). These data provide a robust baseline against which changes in HTLV-I and HTLV-II seroprevalence in Europe can be measured.     

Distribution of neurotensin binding sites in rat brain: a light microscopic radioautographic study using monoiodo [125I]Tyr3-neurotensin

The topographic distribution of specifically labeled neurotensin binding sites was examined by light microscopic radioautography in rat brain sections incubated with monoiodo [125I]Tyr3-neurotensin. Preliminary experiments indicated that under the present experimental conditions [125I]neurotensin specifically binds to a single apparent population of sites with a dissociation constant of 7.7 +/- 0.3 nM, and that fixation of the labeled sections with glutaraldehyde ensures regionally proportional retention of more than 70% of bound [125I]neurotensin molecules. High concentrations of [125I]neurotensin binding sites were detected in the olfactory bulb and tubercle, parts of the neocortex, the lateral septum, the diagonal band of Broca, the caudate putamen, the amygdala, the dentate gyrus, the anterior dorsal nucleus of the thalamus, the suprachiasmatic nucleus of the hypothalamus, the medial habenula, the zona incerta, the substantia nigra and the ventral tegmental area. In certain areas, such as in the diagonal band of Broca, the substantia innominata, the nucleus basalis and the pars compacta of the substantia nigra, discrete accumulations of silver grains were apparent over neuronal perikarya and their proximal dendrites. In most areas, however, the label appeared more or less uniformly distributed over nerve cell bodies and surrounding neuropil. In several instances, the labeling conformed with the distribution of cell bodies of origin and terminal aborizations of specific projection systems, suggesting that neurotensin receptors might be distributed both proximally and distally on the plasma membrane of certain neurons. Such putative "neurotensinoceptive" projection systems might involve part of the mesostriatal, mesocortical and mesolimbic dopamine systems, as well as the raphe-prosencephalic serotonin system and the habenulo-interpeduncular and basal forebrain-cortical cholinergic systems. Finally, areas of dense [125I]neurotensin labeling often corresponded to zones previously shown to exhibit intense acetylcholinesterase staining, suggesting the existence of a possible link between the expression of neurotensin binding sites and that of acetylcholinesterase in certain neuronal populations.     

Increased aneuploidy in spermatozoa from testicular tumour patients after chemotherapy with cisplatin, etoposide and bleomycin

Testicular cancer is the most common neoplasia occurring in the young male population. The PEB (cisplatin, etoposide and bleomycin) adjuvant chemotherapy usually proposed after orchidectomy in non seminomatous tumours, and in metastatic seminomas, has improved the long-term survival of these patients. Following an azoospermic period, sperm cell recovery is generally observed after treatment delivery, but little is known about the genetic consequences on these new spermatozoa. To estimate the chromosomal consequences of this chemotherapy on sperm cells during the period of recovery of spermatogenesis, sperm cell aneuploidy was studied in testicular cancer patients, at 6-18 months after PEB adjuvant chemotherapy delivery, using fluorescence in-situ hybridization (FISH) of chromosomes 7, 16, 18, X and Y with specific DNA probes. A significant increase in the frequency of diploidy and disomy for chromosomes 16, 18 and XY was observed in treated patients compared with a healthy control group. Spermatozoa aneuploidy occurring during the spermatogenesis recovery period might be a possible side effect of the PEB regimen. Thus, practitioners should be advised to provide counselling about the need for an appropriate duration of contraception. Moreover, genetic counselling should be offered in cases of pregnancy occurring soon after the end of chemotherapy.     

Polynucleotide Immune Complexes in Serum and Glomeruli of Patients with Systemic Lupus Erythematosus

Several types of antipolynucleotide antibodies were eluted by acid buffer or deoxyribonuclease treatment of glomeruli obtained from nine kidneys from patients with systemic lupus erythematosus (SLE). Anti-SDNA antibodies were found concentrated over serum levels in eight eluates, anti-NDNA in six eluates and anti-RNA Pr in four eluates; anti-DSRNA antibodies were not demonstrable in any eluate tested. Deoxyribonuclease treatment eluted a high incidence and greater quantity of anti-NDNA and anti-SDNA antibody, whereas anti-RNA Pr antibody was mainly eluted by acid buffer. Simultaneous studies of antibody and antigen in serial serum specimens and in glomeruli suggested that complexes of SDNA antibody or antigen excess were frequently deposited in SLE kidneys, in addition to complexes containing anti-NDNA and anti-RNA Pr. It was observed that studies of antibody titers alone were inadequate for predicting the types of complexes deposited in the kidney. Either antigen excess could obscure detection of humoral antibody or extremely high titers of antibody as observed for RNA Pr are not conducive to the formation of kidney localizing immune complexes in the absence of antigen. Immunofluorescence studies demonstrated the presence of SDNA antigen in most cases from which anti-SDNA antibody was eluted providing direct evidence for the presence of SDNA-anti-SDNA complexes in renal glomeruli. A study of complement components indicated that Clq was absent from cases in which little or no SDNA was deposited in renal glomeruli; although all nephritic kidneys demonstrated C3 deposits. Several hypotheses accounting for this observation are discussed, including the probable utilization of the alternate pathway by certain types of complexes and a direct reaction between C1q and circulating or tissue-bound NDNA or SDNA.