Teratogenic effects of avidin-induced biotin deficiency in mice

Teratogenic effects of maternal biotin deficiency were examined at different levels of severity by adding three levels of avidin (10, 20, or 40 mg/kg) in the basal diet. There was a considerable increase of fetuses with multiple congenital malformations (micrognathia, cleft palate, and micromelia) with increasing amounts of avidin. The dose-response relationship was observable in the incidence of each malformation as well. The body weight of live fetuses was also significantly reduced. However, the dams did not exhibit any typical signs of biotin deficiency, such as loss of hair, dermatitis, or nervous irritability. These results suggest that biotin is important for early embryonic development in the mouse.     

Activation of ATPase Activity in the Chromatin Fraction of Pea Nuclei by Calcium and Calmodulin

ATPase, especially the Ca^2$-dependent enzyme, in the chromatinfraction isolated from nuclei of pea seedlings was activatedby bovine brain calmodulin and by protein that was judged tobe calmodulin from its Ca^2$-dependent activation of NAD kinase.This calmodulin-dependent ATPase activity was blocked by calmodulin-specificinhibitors. (Received July 11, 1983; Accepted October 24, 1983)     

Depside as potent inhibitor of prostaglandin biosynthesis: a new active site model for fatty acid cyclooxygenase

Forty depsides and depsidones, the esters of phenolcarboxylic acids, were examined for their inhibitory effect against prostaglandin biosynthesis with rabbit renal microsomes. 4-0-Methylcryptochlorophaeic acid was the most active inhibitor so far tested and its IC50 value was 0.34 muM. Kinetic investigation has shown that this depside acts competitively with respect to arachidonic acid as most of the non - steroidal antiinflammatory drugs. X-Ray analysis has revealed that 4-0-methylcryptochlorophaeic acid maintains its rigid conformation by forming a strong hydrogen bond between the hydroxyl and methoxyl groups. Comparison of CPK models between 4-0-methylcryptochlorophaeic acid and non-steroidal antiinflammatory drugs revealed that the carboxyl group and the two rings of these drugs are almost superimposable to those of the depside. This finding led us to propose a new active site model based on the three dimentional structure of the depside.     

Antidiuretic activity of teleost urophysial extracts in the rat

Summary Extracts of the carp urophysis elicit a marked decrease in urine flow in the anaesthetized hydrated rat. Reproducible dose-dependent responses are obtained within the range of 2 to 16 g of acetonedried carp urophysis per 100 gBW of the rat. The carp urophysial antidiuretic substance is peptidic, and is different from the neurohypophysial peptides. The bulk of antidiuretic activity is located in the electrondense granules in the carp urophysis. The antidiuretic substance, probably urotensin I, is found generally in teleost urophyses. The activity per mg of acetonedried urophysis is higher in freshwater teleost species than in seawater species.Abbreviations AVP arginine vasopressin - AVT arginine vasotocin - LVP lysine vasopressin - US carp urophysial standard preparation     

Screening method for prolidase deficiency

Summary A simple procedure was developed to determine prolidase activity in dried blood specimens. One thousand dried blood specimens from newborns were examined by this new method. Prolidase activities ranged from 140 to 370 nmol per 3 mm disc per hour (233±43, mean ± SD), and less than 2% of the samples overlapped the heterozygote values. This method should be useful in the mass screening for prolidase deficiency.This research was supported by a Research Grant from the Ministry of Education Japan 1979     

Immunohistochemical study of basement membrane reconstruction by an epidermis-dermis recombination experiment using cultured chick embryonic skin: induction of tenascin.

The production of extracellular matrix components such as laminin, Type IV collagen, fibronectin, and tenascin during the formation of basement membrane in cultured epidermis-dermis recombinant skin of 13-day-old chick embryo was analyzed immunohistochemically. The epidermis and dermis were separated from each other by treatment with EDTA and/or dispase. The basal lamina of the basement membrane was thus removed from both epidermis and dermis. The isolated epidermis was overlaid onto the isolated dermis, i.e., recombined, and then cultured for 1-7 days in a chemically defined medium (BGJb) on a Millipore filter. Immunofluorescence labeling was used for light microscopy and HRP or colloidal gold labeling for electron microscopy. In specimens from 2-day cultures, positive sites of anti-laminin and anti-fibronectin reaction were observed light microscopically as patches which, at the electron microscopic level, corresponded to fragments of the basal lamina located immediately beneath and in the vicinity of the attachment plaques of the hemidesmosomes. The staining pattern became continuous 7 days after recombination. Fluorescence labeling of laminin and fibronectin appeared somewhat earlier than that of Type IV collagen and tenascin. All of the four components were found localized primarily in the basal lamina. Furthermore, fibronectin and tenascin were also distributed in the extracellular matrix of the dermis. The expression of tenascin, which does not exist in the basement membrane of 13-day-old intact embryonic skin, was induced in vitro. These results suggest that hemidesmosomes may play an important role in the reconstruction of the basement membrane and that various components of the basement membrane appeared at different times during the reconstruction.