Expression of a src-type protein tyrosine kinase gene, AcSrc1, in the sea urchin embryo.

By screening a cDNA library and 3'-rapid amplification of cDNA ends, the cDNA for a non-receptor type protein tyrosine kinase from the sea urchin Anthocidaris crassispina was analyzed. The deduced protein (AcSrc1) with the highest identity of about 60% to mammalian Src family kinases shows the characteristic features of the Src family. AcSrc1 mRNA is maternally expressed in unfertilized eggs, while zygotic expression is first detected in blastulae and continues through the pluteus stage. Zygotic mRNA expression, visualized by in situ hybridization, is detected specifically in archenteron at the gastrula stage, while it is restricted in plutei to the midgut and hindgut, suggesting specific roles for AcSrcl in the formation and/or functions of the digestive tract. Meanwhile, western blot analysis has shown that the AcSrc1 protein is constantly expressed throughout embryogenesis. By immunostaining, it was found that the protein (distributed evenly in the cytoplasm of unfertilized eggs) is translocated to the membrane after fertilization. All through the following development, AcSrcl was localized to the peripheries of different embryonic cells, although at a relatively low level of localization at the boundaries between adjacent cells.

The protein tyrosine kinases of the sea urchin Anthocidaris crassispina.

In order to know the function of protein tyrosine kinases (PTKs) in the development of sea urchin embryos, we performed reverse transcription-polymerase chain reaction (RT-PCR) to obtain partial cDNA fragments for PTK genes using primers to highly conserved regions of the PTK family. A total of seven PTK sequences were identified, two of which represented receptor PTK (RTK1 and RTK2), and five of which were non-receptor PTKs (NRTK1-5). RTK1 was highly similar to FGF receptor and Ret kinase, while RTK2 showed features of the insulin receptor family. NRTK1 and 2 belonged to the Src family and could be involved in egg activation at fertilization. NRTK3 showed the features of the Btk family kinases, while NRTK4 seemed to be a member of the Syk/ZAP70 family. NRTK5 is the Csk-type kinase of the sea urchin, which is known to negatively regulate the Src family kinases. RTK1 was not detected in unfertilized eggs and was activated after blastula stage. All the other PTK genes were expressed both maternally in unfertilized eggs and zygotically after fertilization, though each gene showed distinct temporal patterns.

[A case of dissecting aortic aneurysm and presence of anti-Jr(a) antibody].

A 66-year-old woman was diagnosed as a DeBakey type II dissecting aortic aneurysm with angiography and CT. Antibody screening revealed circulating anti-Jr(a) antibody. Preoperatively, erythropoietin was administered twice a week. Over 24 days, a total of 1200 ml of her blood was removed and stored for autologous transfusion. The dissecting ascending aorta was replaced with the aid of cardiopulmonary bypass. The post operative course was uneventful. By using erythropoietin, pre-donated autologous blood, cell saver, aprotinin and transfusion of fresh autologous blood, it was possible to perform cardiovascular surgery on this patient who had an abnormal antibody. This patient is the first case of repair or dissecting aortic aneurysm with anti-Jr(a) antibody in Japan.

Effect of slow release nifedipine tablets in patients with essential hypertension.

The antihypertensive effect of slow release nifedipine (CAS 21829-25-4) tablets (20 mg, Adalat) administered once or twice daily was studied in patients with essential hypertension of WHO stage I or II. Ambulatory blood pressure was monitored by a finger volume oscillometric device every 5 min for 24 h before and during the treatment with nifedipine. Whether administered once or twice daily, nifedipine tablets dit not change the pattern of circadian blood pressure variation; i.e. diurnal rise and nocturnal fall. Twice daily administration induced a significant downward shift in the blood pressure pattern. In other words, further hypotensive effect was observed during the night when the blood pressure was already low. On the other hand, administration once daily in the morning lowered daytime blood pressure without affecting blood pressure during the night. The duration of action of nifedipine tablets administered once daily was 12 h or more. In the acute experiment using 20 mg tablets of nifedipine, plasma concentration of nifedipine was well correlated with the percentage change in mean blood pressure. The minimal effective plasma concentration of nifedipine was estimated to be 13.4 ng/ml. However, in chronic treatment, nifedipine lowered blood pressure at the plasma concentration of 10 ng/ml. The results indicate that nifedipine tablets administered once daily provide an effective antihypertensive regimen for controlling daytime hypertension with minimal antihypertensive effect during the night.

Characteristic of analgesia induced by noncatecholic phenylethylamines in mice.

Using hot plate method, analgesia induced by noncatecholic phenylethylamines, phenethylamine, phenylethanolamine and amphetamine, was inhibited by naloxone, reserpine, apomorphine and p-chlorophenylalanine, while potentiated by haloperidol. These results suggest that phenylethylamines induced analgesia involves central dopaminergic and serotonergic neurons and endogenous opioid peptides. The blockade of dopaminergic neurons enhanced and the inhibition of serotonergic neuron activity or the stimulation of dopaminergic neurons attenuated the phenylethylamines induced analgesia. Using rat hind paw pressing or tail flick test, analgesia induced by electroacupuncture in which Hoku points were electrically stimulated through stainless steel needles was enhanced by phenylethylamines, haloperidol while attenuated by naloxone, reserpine, apomorphine and p-chlorophenylalanine. Thus the analgegic characteristic of phenylethylamines closely resembles that of electroacupuncture.