Lunula corneae in man and primates

Imai (1931) discovered a milk-white crescent on the temporal side of the cornea in Macaca cyclopis. Afterwards he confirmed that such a crescent appears in many kinds of primates, humans and newborn babies in Japan. It was named “Lunula corneae” by Professor S. Adachi. Both workers investigated the nature of the Lunula and considered the meaning of its appearance. Further study on the same problem was carried out by the present authors, when non-transparent tissues as the pactinate ligament and sclera over the ligament. When these tissues situate under the cornea due to the spread of it, they appear as a milk-white crescent. Moreover, the present authors made a statistical investigation on the remains of the Lunula corneae, observed the crescents which were accompanied by the pigmentation in the bulbar conjunctiva and investigated from a hereditary point of view the remains of the Lunula in the Japanese.They established that the Lunula corneae on the temporal side is a sign of the enlargement of the cornea to that side, resulting in a larger visual field on the same side. This is advantageous to primates who live in the open; they exhibit the Lunula throughout life. As concerns humans in Japan, the Lunula always appears in newborn babies, but gradually disappears with age and decreases to 15·7% at 23 years of age. Accordingly, the authors consider the Lunula in man is a kind of rudiment. The Lunula in man is accompanied by the pigmentation in the bulbar conjunctiva in a very high percentage of cases. The authors envisage such a pigmentation in man as a kind of pithecoid mark. Therefore, anthropological investigations on the Lunula corneae and the pigmentation around it would be an interesting subject for study. The authors also gained an insight of the hereditary nature of the Lunula remains. In their opinion such a character is transmittable in man.     

Genetic Mapping in Bacillus subtilis by 5-Bromouracil Sensitization to Ultraviolet Inactivation of Transforming Activities

A new method for chromosome mapping of Bacillus subtilis Marburg is presented which is based on the sensitization to ultraviolet irradiation of transforming deoxyribonucleic acid that has incorporated 5-bromouracil instead of thymine. Deoxyribonucleic acid was extracted at intervals from the outgrowing spores of a thymine-requiring mutant incubated with 5-bromodeoxyuridine and subjected to a definite dose of ultraviolet irradiation. The residual activities of various genetic markers were assayed by transformation. The marker activity of deoxyribonucleic acid that had incorporated 5-bromodeoxyuridine was approximately 10 times as sensitive to ultraviolet irradiation as that of normal deoxyribonucleic acid. The markers proximal to the replication origin were sensitized at earlier times of outgrowth than distal markers. The chromosome replication in outgrowing spores was sufficiently synchronous and allowed the definite determination of when a marker became sensitized by incorporation of 5-bromodeoxyuridine. The time, designated "sensitization time," was estimated by plotting the logarithmic values of relative residual activities versus incubation times. The map constructed with sensitization times as a measurement showed good agreement with those constructed by other methods. The replication of the chromosome under the described conditions appeared to occur in the following marker order: (purA, hisA)-(purB)-(thr, pyrA)-(metC)-(leuA)-(lys, trpC, metB).     

The Use of Cryosurgery in the Control of Locally Recurrent Tumours

Cryosurgery was used as a mode of treatment in 31 patients with advanced tumours.The patients were selected because of failure of other forms of conventional treatment or because a less radical type of therapy was advisable.The primary aim of the treatment was palliation. Pain was well controlled in almost all patients in whom the main bulk of the tumour could be successfully destroyed. Bleeding was also controlled temporarily and obstruction prevented in other patients.Cryosurgery is a simple procedure, easy to perform, has very few complications and can be repeated at frequent intervals. It is well tolerated by the elderly patients and produces very little postoperative discomfort, permitting earlier discharge from hospital.In selected cases of cancer, cryosurgery has a definite role to play in improving the quality of survival. It is particularly useful in extensive and recurrent cancers of the head and neck region.     

Thymidine kinase activation in unfertilized sea urchin eggs by homogenization and fertilization

Kinetics of in vivo phosphorylation of ³H-thymidine taken up by sea urchin eggs was compared between unfertilized and fertilized eggs. The percentage of phosphorylated ³H-thymidine in the total acid-soluble radioactivity in the cell increased with increasing incubation time within the first several minutes of incubation in the unfertilized eggs, while nearly 100% of phosphorylation of thymidine was observed without regards to the incubation time and in spite of a tremendous increase in the net uptake of thymidine in the fertilized eggs, suggesting possible activation of thymidine kinase occurring soon after fertilization.In contrast to the in vivo finding, the thymidine kinase activity in unfertilized egg homogenates was found in general to be almost as large as that in fertilized egg homogenates. However, when the enzyme activity was assayed within a short period (30 min) after homogenization of unfertilized eggs, the activity was found to increase more or less with time after homogenization, reaching a level equal to that in fertilized egg homogenates. This enzyme activation after homogenization was especially marked in case of Pseudocentrotus eggs and sometimes amounted to a several fold increase.Preliminary investigations revealed possible involvement of some redox reaction(s) in the thymidine kinase activation during and/or after homogenization of unfertilized sea urchin eggs.     

Chloroplast Development in 4-Thiouridine-Cultured Radish Seedlings XI. Inhibition of RNA Synthesis by 4-Thiouridine Nucleotides during Germination of Radish Seeds

The effects of 4-thiouridine and its metabolites on RNA synthesisin radish (Raphanus sativus) cotyledons were investigated. The4-thiouridine nucleotides, 4-thioUTP and 4-thioUDP, were foundto inhibit DNA-dependent RNA polymerase activities of isolatednuclei and of chloroplasts from radish cotyledons. These inhibitorsappeared to compete with UTP for its binding to RNA polymerase.Neither 4-thiouridine nor 4-thioUMP inhibited RNA polymeraseactivities. Reduced RNA accumulation accompanied by the inhibition of protochlorophyllideaccumulation was observed in cotyledons of dark-grown radishseedlings germinated and grown with 4-thiouridine. On the otherhand, 4-thiouridine had no effect on chloroplast developmentin the control seedlings germinated and grown without 4-thiouridine.These results suggest that the inhibition of chloroplast developmentby 4-thiouridine may in part be due to the inhibition of RNAsynthesis by 4-thiouridine nucleotide during germination, resultingin inhibition of etioplast development. (Received December 9, 1985; Accepted June 26, 1986)