Factor analysis in clusterbean (Cyamopsis tetragonoloba (L.) Taub)

Summary The pattern of diversity in forty genotypes of clusterbean (Cyamopsis tetragonoloba (L.) Taub) was analysed using the centroid method of factor analysis based on nine characters. Three factors were found to adequately account for most of the intercorrelations in the four environments. Branches, clusters, pods and seed yield/plant could be grouped as productivity factors; days to flowering, maturity and plant height as growth factors; seeds/pod and gum content as economic factor. Interestingly, the constitution of the factors were the same in all the environments. The loadings on the economic factors were relatively unstable, whereas the loadings on productivity and growth factors were stable. It is concluded that productivity and growth factors play a pivotal role towards diversity in clusterbean. The results of factor analysis provides confirmatory evidence of diversity in clusterbean, which was earlier studied by using generalized distance, and thus proves the adequacy of the centroid method in biological investigations.     

Reversion of Texas male-sterile cytoplasm maize in culture to give fertile,T-toxin resistant plants

Summary Plants carrying Texas male-sterile (Tms) cytoplasm are normally sensitive to Drechslera maydis T-toxin. Tissue cultures were initiated from immature embryos of maize carrying Tms-cytoplasm, and plants were regenerated after selection for resistance to T-toxin. Fertile, T-toxin resistant plants were obtained from the unselected control cultures as well as from the selected material. In addition, one regenerant from an unselected culture was fertile and T-toxin sensitive. The progeny of the regenerants showed the phenotype of the female parent with respect to pollen-fertility, and T-toxin resistance. The data are consistent with the heritable changes observed being the result of the expression of an altered mitochondrial genome.     

Kidney grafting between rats which carry recombinant major histocompatibility haplotypes

Kidney transplantation was performed between three congenic rat strains which carried the major histocompatibility haplotypesRT1 ^a ,RT1 ^u orRT1 ^ar1 , the latter being a recombinant betweenRT1 ^a andRT1 ^u . This combination made it possible to test separately the effects of incompatibility for RT1. A-region products (classical transplantation antigens, histocompatibility antigens) and for RT1.B-region products (Ia-antigens, strong mixed lymphocyte stimulating antigens, histocompatibility antigens) as well as RT1.C-region products (lymphocyte differentiation antigens, histocompatibility antigens). It is shown that A plus B plus C, as well as A or B plus C-region incompatibility led to kidney-graft rejection and that matching for either classical transplantation antigens or Ia and strong mixed lymphocyte stimulating antigens had no clear differential prognostic effect on kidney-graft survival.     

The seminiferous epithelium in the guinea fowl (Numida meleagris)

Summary Spermiogenesis and cellular associations in the seminiferous epithelium of the guinea fowl were studied and described in sexually active adult birds. PAS stain was found to be useful in the recognition of steps of spermatid differentiation only in the first early stages. Nuclear morphological changes were subsequently found to be more reliable in tracing steps of spermiogenesis. It was observed that haematoxylin-eosin stained tissue can be used in the study of spermiogenesis in the bird. Various stages of the seminiferous epithelium were observed in any cross-section of the seminiferous tubules. Distinct cellular associations were observed, but intermix of adjacent germ cells or heterogenous cellular associations were frequently encountered.     

Restitution of granule stores in the rabbit parotid gland after isoprenaline-induced secretion

Summary A detailed stereological analysis has been made of the organelle content of rabbit acinar cells during the restoration of granule stores following extensive degranulation with isoprenaline (IPR). Rabbits were sacrificed 2, 4, 8, 12 and 16 h after IPR administration and the volumes and proportions of intracellular organelles were compared with those of untreated glands.At 2 h only 5% of cell volume was occupied by secretion granules, but there was already evidence of nascent granule formation. The volume per cell of secretion granules increased in sigmoid fashion and by 16 h amounted to 350 m³/cell, 36% of cell volume, which are values similar to those of the control replete glands. IPR treatment caused some initial swelling of the cells, and there were transient increases in the volumes of several compartments. However, the volume of mitochondrial and lysosomal compartments had returned to control levels by 4 h and that of the nucleus by 8 h. The greatest increase was in the volume of the rough endoplasmic reticulum which had increased by nearly 70% by 2 h and remained enlarged throughout the period of restitution. However, neither the volume nor the proportion of the smooth membraned compartment varied throughout the period of analysis.The results are analysed in the light of the overall response of the cells to IPR and the interaction of the organelles during the synthetic phase of the secretory cycle. They are presented as a basis for ensuing studies of the granule populations and the membrane composition of the cells during the restoration of granule stores.     

Architecture of normal pancreas as revealed by retrograde injection

Summary The architecture of the pancreas was revealed by retrograde injection of the pancreatic ductal system of normal rats with a silicone rubber compound, and subsequent study of the preparation by light microscopy and scanning electron microscopy. The injected material became associated with both ducts and acinar areas. Examination of these specimens suggests that the arrangement of the exocrine pancreas is that of a complexly curving and branching system of tubules which anastomose and end blindly. This architecture, which is not that of a true acinar gland, provides a rational basis for the understanding of the simple dedifferentiative changes that accompany pancreatic carcinogenesis, and which have been generally interpreted as representing ductular proliferation.Supported by Grant Number CA22063, awarded by the National Cancer Institute, DHEW, through the National Pancreatic Cancer ProjectI thank Mr. Jackson Rhoads and Dr. J. Michael Barrett for information on preparative procedures     

Selective Staining of Eosinophils and Their Immature Precursors in Tissue Sections and Autoradiographs with Congo Red

The use of Congo red as an elective stain for eosinophilic granulocytes and their precursors in tissue sections and autoradiographs is demonstrated and discussed. The 0.5% alcoholic Congo red solution of Highman, normally used for the detection of amyloid, may also be used with only minor changes. This simple method may aid in the diagnosis of special hematological problems and facilitates the recognition of eosinophil granulocytes as well as proliferating and nonproliferating myelocytes in autoradiographs from paraffin sections.     

Calcium and magnesium levels in isolated cardiac mitochondria from mice injected with isoproterenol

Summary Calcium (Ca) and Magnesium (Mg) are determined by atomic absorption flame spectrometry in isolated cardiac mitochondria from mice receiving subcutaneous injections of DL-isoproterenol HC1 (ISO), and in mitochondria of untreated controls. In the controls, mitochondria were isolated in the presence or absence of ruthenium red. On the absence of ruthenium red in the isolation medium, mitochondrial Ca levels increase by about 300%, while levels of Mg remain unchanged. Focal myocardial necrosis following a single ISO-injection is shown by electron microscopy. Ca and Mg levels are largely unaffected by a single dose of ISO until 24 h after the injection. A slight increase in Ca occurs in the 48 h samples. When multiple injections of ISO are given every 12th hour for 48 h, 72 h and 96 h, respectively, endogenous Ca and Mg increase significantly. It is suggested that this increase might be associated with ISO-induced cardiac hypertrophy rather than with the pharmacological effects of ISO per se.This work was supported by grants from The Norwegian Council on Cardiovascular Disease and from The Norwegian Research Council for Science and the Humanities     

Specific paracrystalline structures of rough endoplasmic reticulum in the follicular (stellate) cells of the dog adenohypophysis

Summary The fine structure of follicular cells of the adenohypophysis was examined in fetal, neonatal, and adult beagle dogs. Prior to birth, undifferentiated follicular cells are common. At birth mature cells that form follicles are routinely encountered. The fine structural appearance of follicular cells is unchanged between birth and adulthood. Follicular cells of puppies and adults are, however, distinguished by the presence of unusual complexes within distended cisternae of the rough endoplasmic reticulum. These complexes vary greatly in morphology, some appear as a maze of interconnecting tubules while others show a highly organized paracrystalline configuration. The presence of these paracrystalloid structures in follicular cells supports the view that they represent a distinct pituitary cell type.Supported by NIH Grants AM19743 and NS12969The authors wish to thank John Patrikes and Helen Mantulin for their expert technical assistance