Akute Vitamin A-Intoxikation der Maus

Summary Isolated fixed liver nuclei of Rana pipiens were stained at varied pH by the acid dye, fast green FCF. The amount of nuclear protein, as determined by cytophotometric measurement of the relative absorption of the stained nuclei, was found to increase in proportion to nuclear size when the pH of the dye solution was below 4.0. Relative absorption was found to be independent of nuclear size, but proportional to the pH of the staining solutions in the pH range between 5.0 and 7.0, These data suggest a change in composition and/or structure of the nuclear protein with increasing nuclear size.This investigation was supported by a grant from the U.S. Public Health Service, GM-10003-04.Post-Doctoral Trainee under U.S. Public Health Training Grant to the Department of Pathology, University of Florida, NIH-GM-1142-03.Supported by a Career Development Award from the National Institute of Child Health and Human Development, K3-HD-6176-04.     

Transition from polyteny to polyploidy in salivary glands of Cecidomyiidae

Summary Quantitiative cytochemical studies of Rana catesbeiana liver cell nuclei indicated that these populations consist entirely of diploid non-proliferating nuclei. While DNA values were stable, nuclear size varied over a considerable range. These size variations were directly related to total nuclear protein content, but protein SH and S-S content appeared to be related to ploidy rather than volume. Protein bound tyrosine represents an intermediate case. The latter two fractions appear to be partially bound to nucleic acids, since removal of either class of nucleic acid leads to an increase in absorption values.This investigation was supported by a grant from the U.S. Public Health Service, GM-10003-03.Post-Doctoral Trainee under U.S. Public Health Training Grant to the Department of Pathology, University of Florida, 5 Tl GM 1142-03.Supported by a Career Development award from the National Institute of Child Health and Human Development, K 3-HD-6176-03.     

Quantitative cytophotometric studies on polyploid liver cell nuclei of frog and rat

Summary Nuclei were isolated from fixed liver tissue of diploid and triploid Rana pipiens and of rat. While the frog liver nuclei present a single ploidy class on the basis of Feulgen absorption measurements, rat liver contained diploid, tetraploid, and some octoploid nuclei. Nuclear areas within single ploidy classes varied over wide ranges, especially in the frog material. The mode of this variation was dependent on ploidy. Microspectrophotometric measurements of several protein components were compared to ploidy and nuclear volume. General protein methods indicated a linear relationship to nuclear volume. Protein-bound sulfhydryl and disulfide groups were not related to nuclear volume, but could be related to ploidy. Protein tyrosine values showed a partial dependence on both factors.This investigation was supported by a grant from the U.S. Public Health Service, GM-10003-03.Post-Doctoral Trainee under U.S. Public Health Training Grant to the Department of Pathology, University of Florida, 5T1 GM 1142-03.Supported by a Career Development award from the National Institute of Child Health and Human Development, K3-DH-6176-03.     

Induction of bone,cartilage and hemopoietic tissue by subcutaneously implanted tissue diaphragms

Summary The subcutaneous implantation of appropriate tissue diaphragms (short, broad glass cylinders) rather regularly induces the formation of bones provided with marrow cavities and junction cartilage plates, in the rat.Bone formation, unlike the development of hemopoietic tissue, can be prevented, under these circumstances, by topical blockade of the phagocyte system with carbon particles.The role of nonspecific topical stress factors, in the induction of such highly specific structural transformations, has been discussed.These investigations were supported by Grant No. A-1641 (R1) from the National Institute of Arthritis and Metabolic Diseases, U.S. Public Health Service, by the U.S. Army Medical Research and Development Command, Department of the Army, Contract No. DA-49-007-MD-2039, and by a grant from theGustavus andLouise Pfeifer Research Foundation.     

Mutations affecting levels of tetrahydrofolate interconversion enzymes in Saccharomyces cerevisiae. I. Enzyme levels in ade3-41 and ADE15, a dominant adenine auxotroph

Summary The ADE15, ade3-41 and ser2 markers have been mapped with respect to one another and with respect to the SUC1-MAL1 locus on chromosome VII of Saccharomyces cerevisiae. Three methods have been used for this mapping, viz. conventional tetrad analysis, analysis of single site conversion asci, and analysis of double site conversion asci. The physical distance separating ade3-41 and ADE15, two mutations affecting synthesis of tetrahydrofolate interconversion enzymes, has been estimated.Supported by Public Health Service Research Career Development Award 1K04 AM 36710 and Public Health Service Grant AM 14254 to E. W. J.Supported by Graduate Fellowship from Department of Biology, Case Western Reserve University.     

Histological and histochemical observations on the testis of Gobius paganellus

Summary Histological and histochemical observations on the testis of Gobius paganellus during all seasons of the year are described. In the yearly reproductive cycle, spawning in the Gulf of Naples occured from June through August, testicular recovery and relative inactivity from September through December, and active spermatogenesis from January to May.Germ cells develop as clones from single primary spermatogonia, each clone in a follicle enveloped by cells which are interpreted as Sertoli cell homologues.Glandular tissue is present in large amounts both in the form of interstitial islets and as a large mass along the length of the mesorchium. Cholesterolpositive lipids and ⁵-3-hydroxysteroid dehydrogenase, presumptive evidence for steroid production, are present exclusively in this tissue.Lipids are present in the glandular cells in acidic and neutral forms. The acid fats are the more abundant, but neutral lipids increase in amount in the period April-June. There is, furthermore, a cyclic variation in lipid droplet size, small droplets being present in the spring (during active spermatogenesis) and fewer, larger droplets during the fall (post-spawning period). Phospholipids are lacking.Lactic dehydrogenase activity was weak in the relatively inactive postspawning period, but was much more intense during active spermatogenesis.The glandular tissue in the testis of Gobius is interpreted as homologous with the interstitial (Leydig) tissue found in the testes of higher vertebrates.This investigation was supported by research grant RG-6455 from the Division of General Medical Sciences, U.S. Public Health Service.Postdoctoral Fellow from the Division of General Medical Sciences, U.S. Public Health Service. Supported in part by U.S. Public Health Service Training Grant 5 Tl GM-136, Department of Biological Structure, University of Washington, School of Medicine, Seattle, Washington, U.S.A.     

C. parvum in germ-free mice

Summary The effect of previous sensitization to C. parvum, by cross-reacting antigens from other bacteria, on the immunostimulatory effects of C. parvum treatment were studied in germ-free and conventional mice. It was found that the development of splenomegaly and specific delayed hypersensitivity following C. parvum injection were similar in both germ-free mice and conventional mice.Supported by U.S. Public Health Service Grant No. 5S07 RR05705 and NIH Grant no. AM 18530Visiting Investigator. Present address: Department of Experimental Immunobiology, The wellcome Research Laboratories Beckenham, Kent, England.Recipient of a post-doctoral fellowship from the National Foundation for Ileitis and Colitis Inc.Recipient of Research Career Development Award No. AM 0073 from the National Institute of Arthritis, Metabolism and Digestive Diseases     

Formation,transport, and storage of ribonucleic acid containing structures in oocytes of Acheta domesticus (Orthoptera)

Summary Oocyte development of Acheta domesticus was investigated morphologically and cytochemically. The studies demonstrated a size decrease and final disappearance of a large extrachromosomal DNA body in the nuclei as the cells proceeded through the diplotene stage of meiosis. The body was surrounded by fascicles of RNA containing material. This material remained within the nuclei in individual packets after the DNA body was no longer detectable. An active nucleo-cytoplasmic migration of RNA was seen prior to the disappearance of the DNA body. After the disappearance of the body very little migration was detected. Evidence was presented to demonstrate the ribosomal nature of this migratory RNA. The RNA packets remaining in nuclei of cells arrested in the diplotene stage of oogenesis functioned as storage depots for ribosomal RNA.The authors acknowledge the technical assistance of Miss Agnes Cralley. Dr. D. Ammermann, Zoologisches Institut, Tübingen, W. Germany, provided the animals used in this study. — This work was supported in part by a Health Research Services Foundation Grant No. J-1 and in part by U.S.P.H.S. Grant No. 7-FZCA-23,971-O1A1.     

The diffuse diplotene stage of meiotic prophase in Neurospora

The prophase stages of meiosis in Neurospora crassa are re-examined following McClintock (1945) and Singleton (1953). A diffuse chromosome stage occurring between pachynema and diakinesis is described. It is proposed that the diffuse stage does not necessarily represent a condition of intense gene activity in the sense of directing the metabolic activity of the ascus.Supported by U. S. Public Health Service grants AI-01462 and GM-14263.     

The fine structure of photoreceptors in a marine flatworm

Summary The ocelli or eyes of the marine polyclad turbellarian Notoplana acticola are clustered on the paired dorsal nuchal tentacles and in two longitudinal bands lateral to the cerebral ganglion. The ocelli, studied by electron microscopy, were characterized as rhabdomeric and non-ciliary in origin. There are 60 to 80 ocelli per animal each enclosed in a fibrous capsule to which muscle fibers may attach. An ocellus consists of a pigmented eyecup into which 30 to 50 photoreceptor cells send dendritic processes through interruptions in or among pigment cell projections across the eyecup opening. The dendritic processes terminate in numerous long intertwined microvilli which fill the eyecup. The nucleated cell body of each photoreceptor cell lies outside the eyecup and projects an axonal process to the cerebral mass. Within the dendritic processes are observed mitochondria, ribosomes, neurotubules, multivesicular bodies, vesicles and vacuoles. The cell body contains smaller mitochondria, endoplasmic reticulum, ribosomes, vesicles and prominent Golgi complexes.After dark adaptation, there are some structural alterations in terms of swelling of microvilli, increased numbers of vacuoles associated with the microvilli and dendritic processes, and changes in the pigment cell projections.This work was supported by Grant No. GM 10292 from the U.S. Public Health Service to Professor Richard M. Eakin, Department of Zoology at the University of California, Berkeley, U.S.A., where this investigation was conducted during the author's sabbatical leave of absence from the University of Illinois, and by Grant No. 1 SO 1 FR 5369 from the U.S. Public Health Service to the University of Illinois at the Medical Center.I express appreciation to Professor Eakin for interesting discussions and generous hospitality to me as a guest in his laboratory, and to the John Simon Guggenheim Memorial Foundation for the Fellowship which I held during 1964–65. I thank Dr. John P. Marbarger, Director of the Aeromedical Laboratory for the electron microscope facilities used at the University of Illinois.     

Fine structural relation between the Sertoli cell and the differentiating spermatid in the human testis

Summary The structural relationship between the Sertoli cell and the developing spermatid was studied with the electron microscope. In the contact area of the Sertoli cell with the anterior part of the developing spermatid, a filamentous structure is observed. This structure consists of fine tubular filaments about 100 Å in diameter associated with dense material. The functional significance of the structure is discussed.Supported by Grant HD-00593-05 of National Institutes of Health, United States Public Health Service. The author is indebted to Dr. T. Katayama, Department of Urology, Chiba University, for supplying the materials.     

Ultrastructural changes in nurse and follicle cells during late stages of oogenesis in Drosophila melanogaster

Summary During stages 11 and 12, follicle cells surrounding the nurse cells produce lysosomes which presumably aid in the breakdown of the nurse cells. Accompanying a DNA reduction in nurse cell nuclei are several characteristic morphological changes including the appearance of intranuclear rod-like structures and nuclear granules about 300 Å in diameter. Similarities between structures seen in Drosophila nurse cell nuclei and those seen in other organisms are discussed.This research was supported by U. S. Public Health Service Grants 5TIGM903-3 and 1-F1-GM-33, 385-01 and National Science Foundation grant GB-7457.     

Harvesting and culture of epithelial cells from hollow organs of the female reproductive system

Summary The technique of trypsinization of cells lining the hollow organs applied to the female reproductive tract has proven successful in harvesting living cells which produced luxuriant cultures in vitro.Elements from the oviduct, endometrial cavity and vagina were obtained from 6 rabbits, 2 dogs and 6 surgical specimens by means of bathing the lumen of the organs with the use of a 0.5% solution of trypsin in calcium and magnesium free Gey's balanced salt solution for 30 to 40 min, employing continued gentle agitation provided by a syringe.Epithelial cells so harvested were grown in Rose chambers and in T-30 flasks for as long as 30 days, when they were fixed for study with special stains.No fibrocytic contamination of the cultures was observed.Further applications of the method are under investigation and are briefly outlined in the discussion.This work was performed in the Department of Cellular Biology, Pasadena Foundation for Medical Research, Pasadena, California, and aided in part by a grant from the U. S. Public Health Service, No. 2 G 279 and from the U. S. Army Medical Research and Development Command, Department of the Army, under Research Grant No. DA-MD-49-193-63-G80 administered by C. M. Pomerat.     

Osmium tetroxide versus glutaraldehyde fixation in adrenomedullary tissue

Summary Osmium tetroxide and glutaraldehyde fixation of adrenomedullary tissue presents evidence that these two fixatives preserve the tissue in quite different manners. Not only is the type of fixative of importance, but also the osmolarity of the fixatives is a prime factor in producing an accurate pictorial account of catecholamines.Supported by United States Public Health Service Grants 5-Tl-GM-459, NB 05093-02, FR 0505-01, NB 00690-11 and National Science Foundation Grant GB 25 96.— With the technical assistance of John Yates, Earl Pitsinger and Brenda Ryker.     

On the cilium cell relationship in the adenohypophysis of the mouse

Summary The 8+1 cilia previously reported in the adenohypophysis have been reinvestigated with special emphasis on their relation to the parent cell. In contrast to the fibril pattern which is remarkably constant, this relation shows great variation, supporting the hypothesis that the cilia are rudimentary.This study was supported in part by Grant NB 02215 of The National Institute of Neurological Diseases and Blindness, U. S. Public Health Service. This aid is gratefully acknowledged. The author wishes to thank Dr. Th. Blackstad for valuable advices and Mrs. J. L. Vaaland for skillful technical assistance.     

Cytogenetics of the grasshopper Moraba scurra

Summary The cytology of a male individual of the grasshopper Moraba scurra which was heterozygous for a complex translocation involving breaks in four different, non-homologous, chromosomes, is described. Chains of up to eight chromosomes occur at first metaphase. Certain chromosomes which never normally show more than a single chiasma form two chiasmata with a fairly high frequency in this individual.Supported by Public Health Service Grant No. RG7212-Cl, from the Division of General Medical Sciences, U.S. National Institutes of Health.     

Ultrastructural features of the life cycle ofAcetabularia mediterranea

Summary The portion of the life cycle ofAcetabularia mediterranea from cyst formation to gamete release is described. During maturation, the cyst nucleus undergoes a series of mitoses in which the nuclear membrane remains intact, and the spindle microtubules are confined to the intranuclear space. There is a dark requirement for the completion of cyst maturation at the end of which the nuclei are in groups and centrioles are present. The final migration of the nuclei, cleavage of the cytoplasm into gametes, and the development of flagella is cxtremely rapid, taking six to twelve hours. Cysts which fail to germinate are blocked at a late stage in the maturation process, either before or after the final nuclear division.The observations are related to mitosis in other green algae (Chlorophyceae) and to gametogenesis inBryopsis hypnoides. Changes in the amount and distribution of heterochromatin in the nuclei are discussed in relation to the life cycle ofA. mediterranea.The substance of this paper was first presented orally at the Symposium onAcetabularia held at the Max-Planck-Institut für Zellbiologie, Wilhelmshaven, Federal Republic of Germany, July 12–15th, 1972.Supported in part by Grant GM 06637 from the U.S. Public Health Service.     

Mitochondrion-desmosome complexes in human hepatocytes

Summary Mitochondrion-desmosome complexes similar to those seen in other epithelia were observed in hepatocytes from normal and diseased human livers of children and adults. Their occurrence could not be explained by random distribution of mitochondria in the cells. The close associations of mitochondria with desmosomes supported the hypothesis that the latter might be special areas of intercellular ionic diffusion between hepatocytes.This work was supported in part by United States Public Health Service Grants AI-1059 and TI AM-5384 from the National Institute of Arthritis and Metabolic Diseases, 5 MOl FR 000-50 from the General Clinical Research Center, HD 00674 from the National Institute of Child Health and Development and by a grant from the Life Insurance Medical Research Fund G-65-50.The author is very grateful to Dr. Alex B. Novikoff for the use of the facilities of his laboratory (supported by United States Public Health Service Grant CA-06576), to Mr. Nelson Quintana and Mrs. Julie Windsor for their superb technical assistance and to Miss Marianne Van Hooren for preparation of the photographs.     

Ascospore linearity in the four-spored ascus ofNeurospora tetrasperma

The four-spored ascus ofNeurospora tetrasperma is linearly ordered, i.e. the order of the ascospores within the linear ascus directly reflects preceding meiotic events. This conclusion is based upon the finding of only two types of arrangements of homokaryotic ascospores in asci showing second division segregation and the failure to find any of the other four theoretically possible types of homokaryotic arrangements. The data are also consistent with the regular occurrence of nuclear passing at both the second and third meiotic divisions during ascus development. This work was supported by Public Health Service Grant GM 10672. Supported in part by Public Health Service Training Grant 5-T1-GM-767-05.     

Proline endopeptidase and exopeptidase activity in polymorphonuclear granulocytes

Summary Peptidases capable of releasing proline residues from polypeptides are present in the cytoplasmic fraction of rabbit polymorphonuclear granulocytes. This was shown with peptide substrates where proline is present either at the carboxy-terminal or within the polypeptide chain. Lysosomal and plasma membrane enzymes were inactive towards such polypeptides. The proline residue was hydrolyzed at either its amino end or its carboxy end. It is noteworthy that a Pro:Pro bond was cleaved both in the pentapeptide Thr-Lys-Pro-Pro-Arg and the dipeptide Pro:Pro.Supported by Grant AI-09116 from the National Institutes of Health, U.S. Public Health Service and Grant BMS72-01469 AO3 from the National Science Foundation.