Partial Purification of a Soluble Gibberellin-Binding Protein from Mung Bean Hypocotyls

A soluble binding protein specific for GA₄, GA₇ and GA₉ waspartially purified from mung bean hypocotyls, and its characteristicswere examined. Affinity chromatography using immobilized GA₃coupled to Sepharose 4B via the C-7 carboxyl group was veryeffective for purification of the protein. The molecular weightof the protein in its native state was estimated to be 150–200kDa by gel-permeation chromatography. This protein may be aheterooligomer consisting of two subunits (23 kDa and 35 kDa).The optimum pH for binding of GA₄ to the protein was around6.0 and the apparent dissociation constant (K_d) was 310^-7 M. (Received April 24, 1992; Accepted December 16, 1992)     

Detection of hypoxia in the pulmonary tissues of Xenopus laevis over repeated dives

The oxygen environment in African clawed frogs (Xenopus laevis) continuously changes during their development, which involves a rapid increase in the body size, metamorphosis, and transition to adulthood. Nevertheless, there are limited reports on experimental models that are available for studying fluctuations in the oxygen environment in X. laevis. Thus, this study aimed to develop an experimental model on intermittent hypoxia in X. laevis and evaluate hypoxia and oxidative stress in the same. X. laevis were submerged in water with a dissolved oxygen concentration of 2 mg/L for 30 min; they were then removed from the water and allowed to freely absorb oxygen for 5 min. Immunostaining of pimonidazole-containing frozen tissue sections of the lung and liver using anti-pimonidazole antibodies as the hypoxia probes revealed that more than 95% of the submerged X. laevis cells were pimonidazole positive, providing direct evidence of tissue hypoxia. When the amount of oxidative stress in the lungs and liver was evaluated in terms of the amount of lipid peroxides, the diving group showed a 2.08-fold and 3.20-fold increase over the normal group, respectively. Following hypoxia exposure, the dry-to-wet weight ratios of the lung tissues was 1.27 times higher (p < .05), while the liver tissues was 1.06 times higher (although not significant). Thus, the degree of damage depended on the tissues affected. In the future, we believe that this model will be a promising option for analyzing the physiological responses of X. laevis to hypoxia and oxidative stress.     

Isolation of a Drosophila Gene Encoding a Head-Specific Guanylyl Cyclase

Abstract: We have isolated and characterized a new guanylyl cyclase gene ( dgcl) in Drosophila. The deduced amino acid sequence (683 amino acids) most closely resembled the mammalian solubletype guanylyl cyclase α subunit. The cyclase catalytic domain was highly conserved between the mammalian and Drosophila guanylyl cyclases. The dgcl mRNA was detected in wild-type heads but not in bodies, and its level was reduced in the mutant eyes absent (eya) , indicating that dgcl is preferentially expressed in the CNS and in the eye. The enriched distribution in the eye suggests that dgcl may have a role in phototransduction.     

Effect of prey density on sex ratio of two predacious mites, Phytoseiulus persimilis and Amblyseius womersleyi (Acari: Phytoseiidae)

The sex ratios of two phytoseiid mites, Phytoseiulus persimilis and Amblyseius womersleyi, were observed under various prey conditions. Upon consumption of abundant prey, both phytoseiids produced progeny in a female-biased sex ratio (approximately 0.8 females). When few prey were consumed, the sex ratio was lowered to 0.5 (the unbiased sex ratio). Under the conditions in which the unbiased sex ratio was observed, male and female progeny appeared in an alternating sequence. To determine the change in the sex ratio and the sequence of progeny, the size of eggs deposited by females under various prey conditions was first compared. Survivorship and developmental rate of progeny (immatures) hatched under ample and poor prey conditions were also examined. The eggs deposited under poor prey conditions were smaller than those deposited under ample prey conditions. This is an indication that the phytoseiid females did not invest extra energy into the eggs to secure survival of their progeny under poor prey conditions. The male and female progeny from the small eggs developed slowly, probably due to the small egg size. However, hatchability of the small eggs and survival of the immatures were the same as those of the normal eggs when the immatures were reared under ample prey conditions. The immature survivorship was little affected by the prey consumption rate of their mothers when the immatures were reared under poor prey conditions. We concluded that the sex ratio of phytoseiid mites is not determined by the characteristics of the progeny, but by the nutritious condition of the females.Exp Appl Acarol 22: 709723 © 1998 Kluwer Academic Publishers     

Effect of Yeast Extract and Vitamin B12 on Ethanol Production from Cellulose by Clostridium thermocellum I-1-B

Addition to media of yeast extract, a vitamin mixture containing vitamin B₁₂, biotin, pyridoxamine, and p-aminobenzoic acid, or vitamin B₁₂ alone enhanced formation of ethanol but decreased lactate production in the fermentation of cellulose by Clostridium thermocellum I-1-B. A similar effect was not observed with C. thermocellum ATCC 27405 and JW20.     

Changes in adrenergic receptors during the development of heart failure

Moderate and severe stages of congestive heart failure due to the loss of myocardium upon coronary occlusion in rats was associated with an increase in alpha-adrenergic receptors and a decrease in beta-adrenergic receptors in the viable left ventricle. However, at early stages of heart failure the number of beta-adrenergic receptors was decreased without any changes in the number of alpha-adrenergic receptors. The affinities of these receptors to alpha receptor antagonist (³H-prazosin) and beta receptor antagonist (³H-dihydroalprenolol) were not altered in the failing hearts. On the other hand, the pattern of changes in both alpha- and beta-adrenergic receptors in heart membranes treated with oxygen free radical generating system was different from that seen in the failing hearts. In particular, the affinities for these receptors were decreased whereas the number of beta-receptors was increased and the number of alpha-receptors was decreased or unchanged. These results indicate that alterations in the adrenergic receptors in heart failure are not due to the formation of oxygen free radicals.     

Catalytic asymmetric synthesis of α-methyl-p-boronophenylalanine

p-Boronophenylalanine (l-BPA) is applied in clinical settings as a boron carrier for boron neutron capture therapy (BNCT) to cure malignant melanomas. Structural modification or derivatization of l-BPA, however, to improve its uptake efficiency into tumor cells has scarcely been investigated. We successfully synthesized (S)-2-amino-3-(4-boronophenyl)-2-methylpropanoic acid in enantioenriched form as a novel candidate molecule for BNCT. Key steps to enhance the efficiency of this synthesis were enantioselective alkylation of N-protected alanine tert-butyl ester with a Maruoka catalyst and Miyaura borylation reaction to install the boron functionality.     

Onco-testicular sperm extraction (Onco-TESE) from a single testis with metachronous bilateral testicular cancer: a case report

Background

Although oncologic testicular sperm extraction (onco-TESE) has been increasingly practiced, the evidence of onco-TESE performed in patients with testicular cancer is insufficient. Furthermore, in bilateral testicular cancer, accounting for 0.5%–1% of testicular cancers, onco-TESE is more challenging and has been insufficiently reported.

Case presentation

Here we report the case of a 25-year-old man who underwent onco-TESE from his residual single testis with a nonseminomatous germ cell tumor that occurred 5 years after orchiectomy of the contralateral testis. A second orchiectomy and simultaneous TESE from the noncancerous testicular tissue were performed. The pathological diagnosis was germ cell tumors, tumors of more than one histological type (embryonal carcinoma, immature teratoma, yolk sac tumor, seminoma, and choriocarcinoma; pT1N0M0). The patient subsequently married and hoped for fatherhood 3 years later. Whereas histological diagnosis of the normal testicular tissue was Johnsen score 6 (maturation arrest), morphologically normal and motile sperms were successfully retrieved from thawed TESE samples and used for multiple cycles of intracytoplasmic sperm injection. Although the conception has not been succeeded to date, ICSI attempts have been continuing.

Conclusion

This case demonstrates the effectiveness of onco-TESE for challenging cases such as bilateral and nonseminmatous testicular cancer.