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At least 19 recordsLinked to original sources
PubMed1979

[Studies on DNA content of tissues and organs. 1st communication: changes in cell content of some mesenchymal and parenchymatous rat organs during development, maturation, and in part aging (determinations of DNA) (author's transl)].

In this study the cell content was analyzed by means of the DNA content of certain mesenchymal and parenchymal organs of the rat. The main aspects were the postnatal stages of development and maturation. Their correlation to aging was examined only on examples, so was their correlation to the prenatal development (on 2 examples: liver and skin). One important result of this research is that a gradual reduction in the exponential growth takes place with increasing maturation and development. The "growth by production" prevails over the "growth by division" (of cells). This is the explanation for the "relative" (= apparent) decrease in the cell content of the tissues and organs analyzed during the decisive postnatal development and maturation phases. In this period the complete differentiation of the cytoplasmic structures and of the differentiation products of the tissues and organs here analyzed occurs. This leads to a shift in their relative amounts to the disadvantage of the cell nuclei, which prevailed in the total weight of tissues and organs during the early phases of development. This concerns determinations of the DNA content related to wet weight even more than such of the DNA content related to dry weight. As already shown clearly, the different tissues and organs of the mammalian organism (here on the example of the rat) grow, mature and age differently. During growth different phases can be distinguished, too, by analysis of the DNA content which partly correlate with phases of growth which were differentiated morphologically. Determinations of DNA contents are necessary as parameters for determinations of the production metabolism (e.g. activities of enzymes, products of formation and differentiation) of the different tissues and organs during their development, maturation and aging.

Aging↗
PubMed1979

The neuronal organization of the rat subfornical organ in vitro and a test of the osmo- and morphine-receptor hypotheses.

1. Extracellular action potentials (units) were recorded from rat subfornical organ explants in vitro in response to addition of angiotensin II (AII) or carbamyl-choline (carbachol) or serotonin (5-HT) to the superfusion solution. The frequency recorded was dose dependent over a wide range (AII, 0.05--5 nM; carbachol, 2.7--2700 nM; 5-HT, 1--100 nM). Appropriate antagonists, sarc1-ala2 angiotensin (saralasin) for AII, atropine sulphate for carbachol and methysergide maleate for 5-HT, blocked these excitations. The effects were reversible except for that of atropine. 2. Two populations of AII-excited units were found. A superficial population lying between 15 and 45 microns from the ependymal surface was blocked only by saralasin and another population lying more than 55 microns below the ependymal surface could be blocked by atropine as well as saralasin. Carbachol-evoked units generally lay below 45 microns, and 5-HT-evoked units were scattered evenly over the subfornical organ. It is suggested that superficial AII-excited neurones have a cholinergic excitatory synapse with the deeper carbachol-excited neurones. 3. No evidence was found for the hypothesis that neurones of the subfornical organ are excited by morphine or by changes in extracellular osmotic pressure. 4. All types of drug-excited unit, both superficial (15--55 microns) and deep (below 55 microns), could be driven polysynaptically from the body or columns of the fornix. Units driven antidromically or antidromically and synaptically were almost all more than 55 microns from the surface. 5-HT-evoked units were driven antidromically only by stimulation of the columns of the fornix. AII- and carbachol-evoked units could be driven antidromically or antidromically and synaptically by stimulation of the body or the columns of the fornix. It is suggested that AII units driven antidromically are actually carbachol-sensitive neurones driven by the more superficial AII-sensitive cells. 5. A model of the neuronal organization of the subfornical organ is suggested in which AII-sensitive neurones lying superficially are excited by substances borne by blood or cerebrospinal fluid and synapse with deeper carbachol-sensitive neurones. The axons of these deep neurones pass out of the subfornical organ in the columns and body of the fornix. Afferent fibres from the body and columns of the fornix polysynaptically excite both superficial and deep neurones. A recurrent inhibitory circuit is suggested on the output path.

Action Potentials↗
PubMed1977

Biologically oriented organic sulfur chemistry. 15. Organic disulfides and related substances. 41. Inhibition of the fungal pathogen Histoplasma capsulatum by some organic disulfides.

In an extension of promising inhibitory results in vitro against Histoplasma capsulatum, correlated earlier using substituent constants developed by regression analysis with 77 disulfides, one symmetrical and 14 unsymmetrical disulfides were prepared (3--17). About half were active in vitro against H. capsulatum (and one against Candida albicans). Groups that seemed most to lead to promising inhibition among the unsymmetrical disulfides were o-HO2CC6H4, (CH2)4SO2Na, Me2NC(S), p-ClC6H4, and perhaps p-CH3C6H4; the first two also might be used to increase solubility. Earlier inhibitory promise of the morpholino group did not materialize. None of the group 3--17 was significantly active in vivo. The unsymmetrical disulfides were prepared by reaction of thiols with sulfenyl chlorides or with acyclic or cyclic thiosulfonates. Two six-membered heterocyclic disulfides (5 and 6) were prepared by a novel cyclization, in which carbon disulfide reacted with an (N-alkylamino)ethyl Bunte salt, followed by ring closure; an explanation is suggested for formation of a thiazoline when the N-alkyl group is absent. One of the disulfides disproportionated with astonishing ease (31; 0.3--1 h at 25 degrees C).

Amphotericin B↗
PubMed1975

Histological and three dimensional organization of the odontogenic organ in the lower incisor of 100 gram rats.

A three dimensional reconstruction of the epithelial tissue at the apical end of the lower rat incisor was made from serial 1 mum thick cross sections. This tissue formed an elongated structure, called the odontogenic organ, which was composed of a bulbous and a "U"-shaped part. Both parts were joined to one another at the posterior aspect of the apical foramen. The bulbous part of the odontogenic organ was situated at the lingual side of the "U"-shaped part and protruded anteriorly over the pulp. It was formed by cells of the outer dental epithelium and stellate reticulum whose organization suggested that the bulbous part was important in the production of cells for renewal of all the epithelia of the incisor. The "U"-shaped part of the odontogenic organ was apparently derived from the bulbous part and delineated the pulp by forming the lateral, mesial and labial sidewalls around the apical foramen. It was composed of all the epithelial cell types recognizable as precursors to (a) cells of the enamel organ which form the enamel, and (b) Hertwig's epithelial root sheath, a part of the odontogenic organ which induces the formation of dentin on the lingual aspect of the incisor.

Ameloblasts↗
PubMed2026

Endodermal Organoids Along Two Axes: Single-Organ Fidelity, Inter-Organ Reconstruction, and the Unbuilt Gut-Lung Frontier.

Three-dimensional organoids of the gut, liver, and lung have become mainstream models of human development, disease, and therapy. These organs share an embryonic endodermal origin, yet the field measures their progress inconsistently because the word "maturity" carries two unrelated meanings. Herein, we review the organoid work across all three organs and propose that the two orthogonal axes of advancement be analyzed separately. The first axis is single-organ fidelity. Adult stem cell organoids are faithful but partial, reproducing the adult epithelium of their source tissue with genomic stability yet lacking stromal, vascular, immune, and neural compartments. Human pluripotent stem cell organoids are complete but immature, co-emerging with multiple lineages yet arrested in a fetal-like state. The cost of each limitation is organ-dependent, smallest in the intestine, largest for hepatic drug metabolism, and most spatially defined across the proximal and distal lungs. The second axis is inter-organ reconstruction, where progress is strongly asymmetric. The gut-liver axis is comparatively advanced and sustained by linked organoid and microphysiological systems. The gut-lung axis, by contrast, remains the least-developed frontier, and no such linked organoid has yet been built. We therefore frame it as a proposal, using in vivo and correlative evidence to outline the design principles for such a model. Four bottlenecks recur across both axes: limited vascularization; batch-to-batch variability; organ-skewed immune, microbial, and stromal microenvironments; and unidirectional signaling. We argue that benchmarking models against single-cell developmental atlases and prioritizing construction of the gut-lung frontier should guide the field over the next decade.

Intestines↗
PubMed1976

The biphasic effect of organic cations on the excretion of other organic cations.

The renal excretion of 14C-choline or 14C-acetylcholine was increased by the infusion of another organic cation at low rates but was decreased by infusion of the same added organic cation at higher rates with the Sperber technique in hens. The range of low rates of infusion was from 1 X 10(-15) to 1 X 10(-8) mol/min. At infusion rates greater than 1 X 10(-8) mol/min, inhibition of tubular excretion was found. At the low infusion rates, thiamine, lysine, quinine, atropine, acetylcholine and methylguanidine were found to increase 14C-choline excretion. The same compounds with the exception of lysine and acetylcholine inhibited 14C-choline excretion at the higher infusion rates. A biphasic effect on 14C-acetylcholine excretion was also observed with added atropine, thiamine and choline over the same infusion range. Increases in 14C-choline excretion occurred during a choline infusion rate that normally produced an excretory tubular maximum for choline whereas increases in 14C-acetylcholine excretion occurred during infusion of tracer amounts of 14C-acetylcholine. The effect of the addition of organic cations was selective for cations since the tubular excretion of organic anions was not affected by the addition of organic cations. The tubular excretion ratio of 14C-thiamine/p-aminohippuric acid increased from 0.25 to 0.95 when the infusion rate of added unlabeled thiamine was increased from 1 X 10(-11) to 1 X 10(-8) mol/min. Enhanced tubular excretion of 14C-thiamine may represent the effect of the increased load of unlabeled thiamine to protect the labeled thiamine from conversion to a nontransportable metabolite. Enhancement of excretion of 14C-choline and 14C-acetyocholine produced by very small amounts of other organic cations may represent either inhibition of tubular reabsorptive transport or induction of tubular excretory transport.

Acetylcholine↗
PubMed1975

Histological and three dimensional organization of the odontogenic organ in the upper incisor of 100 gm rats: comparison with the lower incisor.

The epithelial tissue forming the posterior aspect of the apical foramen in the upper incisor of the rat was reconstructed from 1 mum thick serial cross sections. Like the lower incisor, this portion of the odontogenic organ in the upper incisor was composed of a bulbous and a "U"-shaped part. However, the bulbous part was considerably blunter and the "U"-shaped part much larger in circumference in comparison to the lower incisor. Although no differences were found between the upper and lower incisor regarding the contents and the basic organization of cells within each part of the odontogenic organ, specific differences were found within the bulbous part in the upper incisor. There was a more definitive boundary between the outer dental epithelium and stellate reticulum, a more intimate relationship of cell streams to the stellate reticulum, and a noticeable lack of swirling of cells as part of the streams. These features suggest that the activity inside the bulbous part is less intense in the upper incisor than it is in the lower incisor. In addition, the relationships between the bulbous part, the "U"-shaped part and the root sheath part of the odontogenic organ and the enamel organ were described for the upper incisor.

Ameloblasts↗
PubMedDate not supplied

Ultrastructural changes of the nerve elements following disruption of the organ of Corti. I. Nerve elements in the organ of Corti.

3-137 days after disruption of the guinea pig organ of Corti by perilymphatic perfusion with 20% streptomycin (SM), ultrastructural changes of the nerve fibers in the organ were observed. Most of nerve fibers began to degenerate after a latent period of 4 days. On the other hand, a number of fibers survived reactively enlarged and later developed into myelinated and unmyelinated fibers by becoming enclosed in Schwann cells which entered the organ of Corti through the habenula perforata. Regeneration and sprouting of the surviving nerve fibers also occurred. The fibers became mature, but atrophied after 60 days and then gradually disappeared. The regenerating fibers were mainly of the myelinated and unmyelinated efferent type. Retrograde degeneration occurred in both afferent and efferent fibers. In the less damaged organ of Corti perfused with 2% SM or Ringer's solution, Schwann cell invasion was not found.

Animals↗
PubMed1979

Organ weights and organ:body weight ratios of the African white-tailed rat (Mystromys albicaudatus).

Fifty-three adult female and 51 adult male white-tailed rats (Mystromys albicaudatus) were killed with ether and weighed; the spleen, kidneys, liver, heart, lung, pancreas, brain and gonads were dissected free of adhering tissue and weighted. The mean absolute organ weight and organ:body weight ratios by sex and organ were calculated and compared. The male rats were significantly (p less than or equal to 0.05) heavier. The mean weight of the males was 110.0 +/- 23.8 g versus 82.9 +/- 16.1 g for the females. The absolute weights of the heart, liver and kidneys were significantly (p less than or equal to 0.05) greater for the males. The organ:body weight ratios, except for heart and brain (excluding ovary and testicle), were unaffected by sex. The heart to body weight ratio and the brain to body weight ratio were significantly (p less than or equal to 0.05) larger in female rats.

Animals↗
PubMed1976

[Ageing an expression of interrelation between organs and tissue of organism (author's transl)].

The authors starts from results of investigations carried out by himself, dealing with biological cell criteria of organ cultures after the donor animals had been X-rayed on their entire bodies. He discusses the problem whether ageing is an inherent character in all cells. After juvenile rats had been X-rayed, organ cultures of their milts and kidneys showed alterations analogous to those of "old" donor animals. These alterations could not be detected if the animals were killed immediately after X-raying and the cultures were taken then. The alteration of biological cell criteria are discussed as an expression of interrelations between organs and tissues of organism.

Aging↗
PubMed1977

Fine structure of the ordinary lateral line organ. II. The lateral line canal organ of spotted shark, Mustelus manazo.

The lateral line organ of the spotted shark is characterized by its semi-cylindrical shape. Each organ (neuromast) is so closely apposed to the next that the individual neuromasts are almost continuous. The neuromast is composed of receptor cells, supporting cells and mantle cells. The receptor cells bear one kinocilium and up to 40 stereocilia. Bi-directional arrangement of the receptor cells as occurs in teleosts was demonstrated. Afferent and efferent nerve endings were found at the base of the receptor cells. The supporting cells extend from the basal lamina to the free surface. Long microvilli and a cilium-like "ciliary rod" project from the top of each supporting cell. The cell contains relatively few elements of the Golgi apparatus and little rough endoplasmic reticulum, but mitochondria and filaments are abundant. The mantle cell limits the lateral margin of the neuromast. It is distinguished from the supporting cell because of its long crescent-shaped nucleus and scarce, short microvilli. Myelinated nerve fibres are found in the subepithelial connective tissue but not in the epithelium. The fine structure of the shark lateral line organ suggests that this organ is in an intermediated step of evolution between that of lamphrey and teleost.

Animals↗
PubMed1976

Chemocommunication among domestic cats, mediated by the olfactory and vomeronasal senses. II. The relation between the function of Jacobson's organ (vomeronasal organ) and Flehmen behaviour).

The function of Jacobson's (vomeronasal) organ in mammals has intrigued man for more than a century, despite the fact that he does not have this sense organ at his disposal. Two ideas gradually developed about its possible function: the morphology of the organ suggests that it is especially appropriate to receive non-volatile chemical stimuli. Secondly it might have to do with the reception of sexual pheromones. The aim of this study was directed towards both assumptions. Observations of cats show that the way of sniffing at several odours and especially urine, suggests an uptake of dissolved particles. The observations as described in Part I indicated that urine of estrous female female positively influences the frequency of flehmen in tomcats. These results, combined with the effect of experimental blocking of the entrance of Jacobson's organ on this behaviour supported both ideas referred to.

Animal Communication↗
PubMedDate not supplied

[The dynamics of accumulation of trans-isomers of unsaturated fatty acids in the organs and tissues of animals and their use by the organism].

Tests were conducted with two groups of growing albino rats kept on a ration with hydrogenated fat containing 62 and 26 per cent of non-saturated fatty acids transisomers. The latter were found to accumulate in the lipids of the animal organs and tissues reaching their maximum level by the 4th week of the experiments. On switching the rats to a ration containing no transisomers their exponential fall in the lipids of the organs and tissues was recorded. From these investigations it follows that the non-saturated fatty acids transisomers taken up by the organism together with edible fats become involved in metabolic processes and are utilized by the organism alongside with other fatty acids.

Adipose Tissue↗
PubMed1975

Acetylcholine-binding substance extracted by using organic solvent and acetylcholine receptor of electric organ of Narke japonica.

1. Proteolipid was extracted from the electric organ of Narke japonica by using chloroform/methanol (2:1, v/v). This extract was separated into acetylcholine-binding and non-binding substances by column chromatography. However, acetylcholine-binding substances did not show the characteristic properties of protein. 2. The membrane fragments of the electric organ were separated into three main parts by sucrose density gradient centrifugation. From the heaviest, the fractions were acetylcholine receptor rich, ATPase rich, and acetylcholinesterase rich. 3. The membrane fraction having acetylcholine receptor showed the excitability, the increase of Na+ permeability by the application of cholinergic agonists. However, the acetylcholine binding substance extracted by the organic solvent was richer in the lighter fraction. This substance differed from the true acetylcholine receptor.

Acetylcholine↗
PubMed1977

The effect of chronic underfeeding on organ weights of rats. How to interpret organ weight changes in cases of marked growth retardation in toxicity tests?

Growing male rats were kept on a restricted feed intake. After 13 weeks they reached a final body weight of 250 g in comparison with 366 g of their ad lib. fed controls. The relative weights of the heart, kidneys, spleen, pituitary and prostate/seminal vesicle were not altered by underfeeding. The relative weights of the brain, adrenals and tests were increased by 30 to 40% in the feed-restricted groups, the thyroid by about 20%. The relative weight of the liver was decreased by about 30%. When growth is markedly reduced in a toxicity experiment alterations of this kind in the organ weight: body weight ratios have to be expected as a physiological response of the organism to decreased feed intake. They must be differentiated from organ weight changes resulting from primary toxic influences of the drug tested.

Age Factors↗
PubMed1976

Chromatin organization in nuclei of sea urchin embryos. Comparison with the chromatin organization of the sperm.

The chromatin in sea urchin embryo nuclei and that in sperm heads are both organized in nucleosomes but show marked differences when analyzed by endonuclease digestion. Sperm chromatin DNA appears to be totally organized in nucleosomes that are highly resistant to nuclease hydrolysis. The kinetics of formation of acid-soluble oligonucleotides is slow and concerns only about 50% of the total DNA. In contrast, the DNA of embryo chromatin does not appear to be totally organized in nucleosomes since 5 to 10% is rapidly and preferentially hydrolysed into acid-soluble oligonucleotides without any appreciable fragmentation of the remaining parts. Futher digestion causes the formation of the usual pattern of DNA bands, as detected by gel electrophoresis. The length of the DNA segment associated with the embryo nucleosomes appears to be shorter than that of the DNA segment associated with the sperm nucleosomes. The kinetics of formation of acid-soluble oligonucleotides upon digestion of embryo chromatin is much faster than that of sperm chromatin and concerns almost all the chromatin DNA.

Animals↗