Embryonic development of the grass pufferfish (Takifugu niphobles): From egg to larvae.

Tetraodontidae (pufferfish) family members carry the smallest genomes among vertebrates, and these pocket-sized genomes have directly contributed to our understanding of the structure and evolution of higher animals. The grass pufferfish (Takifugu niphobles) could be considered a potential new model organism for comparative genomics and development due to the potential access to embryos, and availability of sequence data for two similar genomes: that of spotted green pufferfish (Tetraodon nigroviridis) and Fugu (Takifugu rubripes). In this study, we provide the first description of the normal embryonic development of T. niphobles, by drawing comparisons with the closely related species cited above. Embryos were obtained by in vitro fertilization of eggs, and subsequent development was monitored at a constant temperature consistent with natural conditions. T. niphobles development was divided into seven periods of embryogenesis: the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods; and stages subdividing these periods are defined based on morphological characteristics. The developmental stage series described in this study aims to provide the utilization of T. niphobles as an experimental model organism for comparative developmental studies.

HpEts, an ets-related transcription factor implicated in primary mesenchyme cell differentiation in the sea urchin embryo.

The mechanism of micromere specification is one of the central issues in sea urchin development. In this study we have identified a sea urchin homologue of ets 1 + 2. HpEts, which is maternally expressed ubiquitously during the cleavage stage and which expression becomes restricted to the skeletogenic primary mesenchyme cells (PMC) after the hatching blastula stage. The overexpression of HpEts by mRNA injection into fertilized eggs alters the cell fate of non-PMC to migratory PMC. HpEts induces the expression of a PMC-specific spicule matrix protein, SM50, but suppresses of aboral ectoderm-specific arylsulfatase and endoderm-specific HpEndo16. The overexpression of dominant negative delta HpEts which lacks the N terminal domain, in contrast, specifically represses SM50 expression and development of the spicule. In the upstream region of the SM50 gene there exists an ets binding site that functions as a positive cis-regulatory element. The results suggest that HpEts plays a key role in the differentiation of PMCs in sea urchin embryogenesis.

Outcome of Bankart repair in contact versus non-contact athletes.

BACKGROUND: The clinical results of arthroscopic Bankart repair for contact athletes varies according to published reports. The purposes of this study were to analyze the clinical outcome of open or arthroscopic Bankart repair and to investigate the results in contact and non-contact athletes. HYPOTHESIS: Clinical outcome of arthroscopic Bankart repair is similar to that of open procedure. PATIENTS AND METHODS: One hundred patients with recurrent anterior shoulder dislocation without a large bony defect were retrospectively reviewed. Fifty-one contact and 49 non-contact athletes were found with a mean follow-up of 17 months. Forty-nine shoulders underwent arthroscopic Bankart repairs; 51 shoulders had open Bankart repairs. RESULTS: In non-contact athletes, there was a 5% (1/22 cases) recurrence rate in the open group and 4% (1/27 cases) in the arthroscopic group. In contrast, in contact athletes, there was a 10% (3/29 cases) recurrence rate in the open group and 14% (3/22 cases) in the arthroscopic group. There was no significant difference in the recurrence rate between contact and non-contact athletes, although contact athletes showed two to three times a higher recurrence rate than that of non-contact athletes. The Rowe score and Constant score showed no significant difference between the two procedures and between the contact and non-contact athletes. The rate of the complete return to sports showed no significant difference between contact and non-contact athletes. CONCLUSION: The recurrence rate of Bankart repair in the contact athletes was 2 times higher in the open group and 3 times higher in the arthroscopic group than in the non-contact athletes. Clinical outcome of arthroscopic Bankart repair was similar to that of open procedure.

Cloning of cyclin E cDNA of the sea urchin, Hemicentrotus pulcherrimus.

cDNA encoding maternal cyclin E (HpCycE) has been cloned from the oocyte cDNA library of the sea urchin, Hemicentrotus pulcherrimus, by differential screening with a cDNA probe covering the total poly(A)+ RNAs of 16 cell-stage embryos and gastrulae. In this communication we describe similarity of amino acid sequences between HpCycE and those of cyclin E from other organisms and maternal origin of HpCycE. The amino acid sequence deduced from the nucleotide sequence of HpCycE cDNA is highly similar to those of human, rat, chicken, Xenopus, zebrafish and Drosophila, while its similarity to other cyclins is much lower. A gene for HpCycE exists as a single copy in the genome of H. pulcherrimus. Northern blotting revealed that the mRNA for HpCycE is maintained at a high level up to the morula stage and thereafter declines.

[Clinical study on the inhibitory effect of AA-2414 on platelet function in asthmatic patients].

We studied the effect of AA-2414, a TXA2 receptor antagonist, on platelet function in 12 asthmatic patients, 6 males and 6 females, whose mean age was 43.6 years. AA-2414 was orally administered to each patient at 20 mg/day for two weeks and then at 40 mg/day for the following two weeks. Platelet aggregation, plasma concentration of TXB2, and serum concentrations of AA-2414 and its metabolites were measured before and after the administration of each dose. Platelet aggregation induced by U-46619 (an analogue of PGH2), STA2 (a stable analogue of TXA2) and arachidonic acid with the administration of AA-2414 was significantly inhibited. The degree of this inhibition was proportional to the serum level of the drug. Plasma concentration of TXA2 tended to be lowered by administration of AA-2414, but it was not statistically significant. Eight (75.0%) of the 12 patients showed clinical improvement. In the cases where the drug was ineffective, the inhibition of platelet aggregation after administration of AA-2414 was less than in those cases where it was effective. We conclude that AA-2414 might exert its antiplatelet and antiasthmatic effects through antagonism of the TXA2 receptor. Investigation of the response to AA-2414 may be useful in assessing the clinical effect of this compound.

Prevalence, clinical significance, and strain specificity of neutralizing antibody to the human immunodeficiency virus.

A semiautomated microtiter assay has been developed to quantitate neutralizing antibody to the human immunodeficiency virus. This assay has been found to be highly specific. Forty-four sera that were negative by enzyme-linked immunosorbent assay (ELISA) were tested under code: 42 were negative (less than 1:2), and 2 had titers of 1:2. By contrast, of 178 sera positive by western blot, 92.7% had detectable neutralizing antibody, and 12.5% had titers greater than or equal to 1:128. Neutralizing antibody titers correlated poorly with clinical diagnosis and T4/T8 ratios. Different isolates differed quantitatively in their sensitivity to neutralization by antibodies obtained from different patients; however, all strains tested so far have been neutralizable by all the sera tested. Neutralizing antibody titers correlated weakly, if at all, with direct or competition ELISA titers.