Kazumasa Hoshino

Distally based lateral calcaneal flap.

In our cadaver dissection, the connection between the lateral calcaneal artery, the lateral tarsal artery, and the branch of the lateral plantar artery was corroborated, indicating possible reverse blood flow in the lateral calcaneal artery. The distally based lateral calcaneal flap has been successfully used in 2 patients. Vascular anatomy, indication, and technical points of the surgery as well as advantages and disadvantages of the flap are discussed.

Effects of prolactin during preincubation of mouse spermatozoa on fertilizing capacity in vitro

In the present study, some beneficial effects of mouse prolactin (PRL) on spermatozoa were demonstrated in mice. The motility rate of spermatozoa is well maintained during incubation in modified Krebs-Ringer bicarbonate solution (mKRB) containing PRL (10 or 100 ng/ml) for up to 120 min. When spermatozoa that had been preincubated in the same PRL-containing mKRB were incubated with oocytes in mKRB, significantly more spermatozoa attached to the zona pellucida of each oocyte. When spermatozoa that had been preincubated in mKRB with PRL (50 and 100 ng/ml) for only 15 or 30 min were used for in vitro fertilization (IVF), significantly higher fertilization rates were yielded by those spermatozoa than by control spermatozoa preincubated without PRL for the same periods. The prolongation of the preincubation period did not result in increased fertilization rates. Thus, PRL demonstrated biological effects on spermatozoa by shortening the optimal preincubation period for spermatozoa to acquire capacitation and by maintaining their motility and ability of the attachment to the oocyte during IVF. The results are relevant to clinical application of PRL for infertile patients with oligozoospermia or asthenozoospermia.

Influences of prolactin upon spermatogenesis and spermatozoa during in vitro fertilization in mice

Hyperprolactinemia, induced by pituitary isografts for 20 weeks in male mice and confirmed by radioimmunoassay using anti-mouse prolactin serum, did not impair spermatogenesis in the testis and maturing processes of spermatozoa in the epididymis. Incubation of freshly obtained epididymal spermatozoa for 90 min in culture media containing various levels of mouse prolactin did not yield any adverse effects on percentage motility rates of epididymal spermatozoa. When the level of mouse prolactin in the preincubation medium for epididymal spermatozoa was 100 ng/ml, the rate of fertilization by these preincubated spermatozoa in the subsequent in vitro fertilization experiment was significantly lowered compared with that observed in controls. However, when the level of prolactin in preincubation media was 10 ng/ml, no significant reduction in the rate of fertilization occurred. The present experiments seem to indicate the existence of some differences in the effects of prolactin on male germ cells until they reach the tail of the epididymis and on the processes of capacitation and/or fertilization by epididymal spermatozoa after they leave the epididymis.

A fluorescence cytophotometer operated under computer control for multi-parameter cell analysis

SummaryA new type of fluorescence cytophotometer has been developed for multi-parameter cell analysis (Olympus BH2-QRFL). For multi-color fluorescence cytophotometry, this instrument is equipped with four sets of interchangeable filters, each consisting of an excitation filter, a dichroic mirror with a barrier filter, and a measuring filter. For permitting automatic operation of the filter sets, the cytophotometer is connected on line with a personal computer (HP 85F). A desired sequence of filter sets can be memorized in the software and multiple cellular constituents can be rapidly and consecutively determined on a single cell basis. All data are stored in the same computer and can be retrieved for further statistical analysis and display either in tabular form, or as histogram, correlation histograms, two-dimensional scatter plot, or two-dimensional frequency distribution histogram, on the CRT (cathode ray tube) with simultaneous hard copy. As an example of multiparameter cell analysis, combined protein and DNA measurements were performed on normal, border-line, and cancerous gynecological cytology specimens by using the ninhydrin-Schiff and Feulgen techniques.

Effects of prolactin on gametes and zygotes during in vitro fertilization in mice

Hyperprolactinemia is one of the major causative factors of infertility. However, the effect of prolactin on gametes during in vitro fertilization has not been elucidated. In the present study, the effects of mouse prolactin on the motility of spermatozoa, in vitro fertilization, and in vitro development of the zygote were investigated in mice using media containing three different concentrations (10, 50, and 100 ng/ml) of mouse prolactin. The development of unfertilized and fertilized oocytes (zygotes) was not affected in vitro by prolactin regardless of the amount of prolactin added to culture media. However, the fertilizing capacity of the spermatozoa was suppressed when they were preincubated for 90 min in culture media containing prolactin at concentrations of 50 and 100 ng/ml. The motility of spermatozoa was not affected by prolactin regardless of the concentration of prolactin used for preincubation. The present study indicates that prolactin may have some effects on the capacitation process of spermatozoa in vitro. This result should be taken into consideration in in vitro fertilization and embryo transfer procedures in humans.

Bioethics in Japan: 1989–1991

During 1989–1991 in Japan, the Japanese government and professional associations took action on two issues: organ transplants from donors declared dead according to brain-death criteria, and the government’s decision to shorten the gestational age limit for legally permissible induced abortions from less than 24 weeks gestational age to less than 22 weeks. Another topic during the past two years, the legitimacy of using liver tissue from live donors, provoked significant discussion but no official action by the government or statements from professional groups. Overall, increasing numbers of people have become aware of the importance of such bioethical concerns as informed consent to medical treatment and experimentation, appropriate criteria for defining death, and standards of decision-making for incompetent patients.

Sexual dimorphism in amino acid compositions of mouse prolactin

Sexual dimorphism was found in amino acid compositions and immunogenecity of variant types of prolactin (PRL) purified from the pituitary gland of normal adult C57BL mice by a high performance liquid chromatography. From the pituitary gland of female mice, three female variant types of PRL were isolated, whereas from the pituitary gland of male mice, two male variant types of PRL (M1-PRL and M3-PRL) and a female variant type of PRL (M2-PRL) were obtained. The amino acid composition of M3-PRL was different from any of female variant types which were very similar to each other and contained less varine, isoleucine, leucine, tyrosine and lysine but more alanine than the latter. Immunoreactivity of any of female variant types of PRL against anti-PRL serum was 100%, whereas that of M1-PRL was as much as 85% and that of M3-PRL was nearly undetectable.