Heterozygous microspore-derived plants in rye

In a particular experimental series involving anthers from F(1) hybrid plants of Secale cereale L., it was possible to induce the formation of 68 microspore-derived plantlets of which 61 were albinos and 7 green. 6 of the albino plants were haploid, whereas most of the others were diploid. All green rye plants were directly diploid and, after extensive screening, proved to be heterozygous. Evidence is presented suggesting that these latter plants arose from unreduced microspores. The significance of this finding is discussed.

[Dendritic lesions in herpes simplex infection of the cornea. Scanning and transmission-electron microscope findings (author's transl)]

Thirty rabbits were divided into 10 groups of 3 animals. In the case of each animal 1 drop of Herpes virus hominis suspension (HVH) was applied to the intact cornea of the right eye. Within the period between the 2nd and 20th day after infection occurred, three animals were killed each time and the corneae were examined by scanning- and transmission-electron microscope. Circular foci and dendritic lesions were observed starting with the 4th day. After the 12th day, dendritic lesions could no longer be observed. Circular foci and dendritic lesions possess a width of about 200 mu which remains unchanged during the entire observation period. The areas of ulceration are obscured by lateral epithelium migrations. The observation that epithelial lesions do not change their demensions over an extended period of time, speaks for an approximate time balance between cellular damage caused by the viruses and the migratory speed of the epithelium. This mechanism is disrupted in the neighboring circular foci. The cytotoxic effect is predominant. Circular foci are confluent. The dendritic lesion so characteristic for herpes simplex infection of the cornea is explained by the confluence of several circular foci which are accidentally positioned next to each other.

Side-effects of local anesthetics on the corneal epithelium of the rabbit eye

The toxic side-effects of 0.4% Novesine and Chibro-Kerakain were investigated by scanning- and transmission electron microscopy in 15 rabbit corneae each in intervals of 3, 6, 10, 15 and 60 mins. The lesions following Kerakain were larger and occurred earlier. After 60 mins, the specimens after Novesine application showed an almost complete repair process, whereas after Kerakain the epithelial surface appeared to be functionally impaired.

Scanning electron microscopy in ophthalmology

In the context the technique of the scanning electron microscopy is described and the results are shown gained by the scanning electron microscope in ophthalmology. It is pointed out that questions specific to surface can be answered quicker and easier, if superificial microscopy together with the scanning electron microscope is used an additional source of information. Scanning electron optical pictures are very useful for ophthalmologic science.

[Pigment glaucoma. Scanning-electronmicroscopic findings. (author's transl)]

In case of a patient suffering from pigment glaucoma trabeculectomy was performed on both eyes. In one trabecular section the outer wall of Schlemm's canal, and in the other the trabecular framework were investigated by scanning-electronmicroscopy. The intertrabecular spaces were largely blocked by pigment granula, which, in some places, were stored in the clump cells of the iris. Even the outer wall of Schlemm's canal was dotted with pigment granula. The scanning-electronmicroscopic findings revealed the pigmental drainage blocking of the aqueous humour and explained the acute pressure rise in the pigment glaucoma with wide iridocorneal angle by an acute obstruction of the already largely blocked intertrabecular spaces.

[Herpes Simplex Keratitis under the Scanning lectron Microscope(author's transl)]

In 12 rabbits a dendritic keratitis could be provoked by applying a suspension of herpes viruses (Herpes virus hominis -- HVH type 1) onto their previously both uviolised and non-uviolised corneae. 4 days later ophthalmectomy was performed and the corneae were examined by the scanning electron microscope. Macroscopically, both in the uviolised eyes and the control eyes punctiform lesions of the corneae were observed. After short ray-treatment (3 min) no differences were present between the uviolised and non-uviolised eyes. At longer time of exposure (7--15 min), however, a more distinct alteration occurred in the uviolised eye. The scanning-electron-microscopical picture showed the dendritic lesions to be composed of numerous circular foci of 100 to 200 mu. There were no differences in the lesions of the uviolised and non-uviolised corneae. The fact that after ultraviolet ray-treatment a great part of the epithelial cells is sloughed off, but, nevertheless, the same dendritic lesions develop, contradicts the assumption of a morphological substrate of the epithelial cells being the inducing factor.