On protein deficiency in mice with special reference to liver nucleolar size

Summary Mice were starved for 2 days and then fed on either a protein-free diet or a 25 per cent casein diet for 7 days and then sacrificed. The former group, in contrast to the latter, decreased in weight during these 7 days and showed significantly lower weight absolute and relative (g/100 g initial body weight) of kidneys, liver and spleen. In the animals deprived of protein, the ratio between total liver nucleolar volume per nucleus and the nuclear volume was larger, than in the casein fed animals. The results suggest that the liver nucleolar apparatus reacts to a protein-free diet in principally the same way in mice as in rats.The investigation was supported by a grant from the Swedish Medical Research Foundation.     

Studies on mammalian glucoamylases with special reference to monkey intestinal glucoamylase

1. Highly purified preparations of glucoamylase were obtained from liver, spleen and intestine of the monkey. The enrichment factor was lower for intestine (60-fold) compared with that of liver (1200-fold) and of spleen (2000-fold) but the final specific activities were of a similar magnitude. 2. The liver and spleen enzymes had maximum activity at pH4.8 whereas the intestinal enzyme showed an optimum at pH5.8. The K(m) values for both starch and maltose with spleen and liver enzymes were higher than for the intestinal enzyme. With the intestinal enzyme, the V(max.) values were higher for both starch and maltose than those of the spleen and liver enzymes. 3. Gel filtration on Sephadex G-200 under identical conditions revealed that liver and spleen enzymes emerge from the columns much later than the intestinal enzyme. 4. Evidence is presented that the glucoamylase activity of the intestinal mucosa is exhibited by the maltase II fraction. 5. Tris, pentaerythritol and turanose inhibited glucoamylase from all the three tissues, but turanose inhibited the spleen and liver enzymes to a higher degree than the intestinal enzyme.     

On intrauterine selection by AB0-incompatibility with special reference to maternal age

Summary As follows from the analysis of AB0 system blood-groups for 3186 mothers with children, a selection takes place in the period of intrauterine growth, this selection being directed against AB0-incompatible zygotes (fetuses). Only in the age-group of mothers below 26 a statistically significant (P>99%) selection effect is observed.

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Zusammenfassung Die Analyse der AB0-Blutgruppenverteilung bei 3186 Müttern und ihren Kindern zeigt, daß während der intrauterinen Entwicklung eine gegen AB0-inkompatible Zygoten (Früchte) gerichtete Selektion stattfindet. Der statistisch gesicherte Effekt (P>99%) der Selektion wurde nur bei den jüngeren als 26jährigen Müttern nachgewiesen.

     

The embryonic development of the intestinal mucosa with special reference to its epithelium

Electron microscopic examinations were made of different parts of the bovine intestine (n = 13) up to the 10th week of embryonic development. During the 'phase of undifferentiated epithelium' the embryonic intestinal epithelium can be classified as stratified and is perhaps a pool of cells. Microvilli of the apical plasmalemma appear at first in neighboring and opposing cells in the centre of the epithelium. They already show microfilaments as well as a glycocalix. The supranuclear cytoplasm shows many granules, vesicles and arciform structures which may be used in the process of microvilli formation. The importance of infranuclear basal granules in the peripheral epithelial cells is still unknown; perhaps they are merely phylogenetic remnants of a principle of development common to all vertebrate intestines. Single cilia which are formed in the periluminal cytoplasm presumably suppress mitotic activities of the epithelial cells and induce their ensuing differentiation. Epithelial proliferation is the initial event of villigenesis, giving rise to epithelial primary villi. Immediately following is the formation of secondary villi during proliferation of the mesenchyme.     

Functional morphology of the enteric nervous system with special reference to large mammals.

This short review reports the latest insights into the structural organization of the enteric nervous system, with special emphasis on the intrinsic innervation of the intestinal tract of large omnivorous mammals such as the pig. Using various techniques, including lesion experiments, morphological and neurochemical features of distinct neuronal populations as well as the direction of the axonal processes within the different nerve networks could be revealed. Special attention was paid to the considerable species differences in this respect between large omnivorous animals and humans on the one hand and small laboratory animals on the other hand.     

Differential effects of two probiotic strains with different bacteriological properties on intestinal gene expression, with special reference to indigenous bacteria

Probiotics are used for the improvement of gut disorders. To explore the potential of probiotics, a gnotobiotic study using BALB/c mice to analyze epithelial gene expression was performed. Microarray analysis of probiotic strain-monoassociated mice showed that Lactobacillus casei Shirota and Bifidobacterium breve Yakult noticeably affected gene expression in the ileal and colonic epithelial cells, respectively, although to a smaller extent than segmented filamentous bacteria (SFB). Lactobacillus casei Shirota enhanced the gene expression involving defense/immune functions and lipid metabolism more strongly than B. breve Yakult. In the colon, expression of a chloride transporter was slightly enhanced, although downregulation of many genes, such as guanine nucleotide-binding protein, was evident in mice with B. breve Yakult compared with the ones with L. casei Shirota. SFB affected gene expression more strongly than the probiotic strains. In particular, alpha(1-2) fucosyltransferase and pancreatitis-associated protein were significantly enhanced only in SFB-monoassociated mice but not probiotic strain-monoassociated mice. Gene expression of SFB-monoassociated mice was either stimulated or repressed in a manner similar to or opposite that of conventional colonized mice. Taken together, probiotic strains of L. casei Shirota and B. breve Yakult differentially affect epithelial gene expression in the small intestine and colon, respectively.     

Embryonic development of Galloisiana yuasai Asahina, with special reference to external morphology (insecta: Grylloblattodea)

The embryogenesis of Grylloblattodea, one of the most primitive of the polyneopteran orders, is described using Galloisiana yuasai with special reference to external morphology. The egg membranes are characterized by an endochorion crossed by numerous vertical aeropyles and a fairly thin vitelline membrane, features shared by Mantophasmatodea. The inner layer formation is of the fault type. Serosal elements in the amnioserosal fold differentiate into hydropylar cells, to function in water absorption together with specialized amniotic structures, i.e., an amniotic strand and a thickened amnion. The germ band is of the short germ type. The germ band immerses deep into the yolk after its full elongation along the egg surface, and in this respect blastokinesis closely resembles that of Mantophasmatodea. The embryological features, i.e., those on egg membranes and blastokinesis, may suggest a closer affinity of Grylloblattodea and Mantophasmatodea. Appendages, ectodermal invaginations, and sternal and pleural sclerites are discussed in the light of serial homology, to provide a new basis for elucidating the insect body plan. Appendages are divided into the proximal coxopodite and distal telopodite, the former being divided further into the subcoxa and coxa. Subcoxal and coxal elements are identified in the mandible as well as in the abdominal appendages. The subcoxa is divided into the epimeron and episternum by the pleural suture in thoracic segments. Likewise, in the abdominal segments the subcoxa is divided into two, although the homologs of the epimeron and episternum are not sclerotized, and in the labial segment the subcoxal derivative or the postmentum is divided into the submentum and mentum. Two coxal endites bulge out from the medial side of the gnathal appendages. The mandibular molar and incisor, maxillary lacinia and galea, and labial glossa and paraglossa are serially homologous with each other. In the thoracic segments the original embryonic sternum or "protosternum" is largely replaced by subcoxal elements, and merely remains as a small anterior presternum and a posterior spinasternum. A major part of the venter is represented by the derivatives of the episternum such as an extensive basisternum, katepisternum, and trochantin and the medial element of the epimeron. The pleuron is derived from the episternal elements or the anepisternum and preepisternum, which bears a spiracle in the mesothorax and metathorax, and the lateral element of the epimeron. The homolog of the preepisternum in the prothorax is the cervical sclerite, but with no spiracle developed. A median ventral invagination arises in the thoracic segments as a spina, and the homolog of the spina develops into the eversible sac in the first abdominal segment.     

Rat proximal small intestinal Golgi membranes: lipid composition and fluidity

The present studies were conducted to examine and characterize the lipid composition and physical state of the membrane lipids of rat proximal small intestinal Golgi membranes. Golgi membranes were purified from isolated enterocytes; lipids were extracted from these membranes and analyzed by thin-layer and gas-liquid chromatography. The 'static' and 'dynamic' components of fluidity of Golgi membranes and their liposomes were assessed by steady-state fluorescence polarization techniques utilizing r infinity and S values of 1,6-diphenyl-1,3,5-hexatriene and r values of DL-2-(9-anthroyl)- and DL-12-(9-anthroyl)stearic acid, respectively. Additional studies were also performed on these membranes, using benzyl and methyl alcohol, to examine the relationship between alterations in lipid fluidity and glycosphingolipid glycosyltransferase activities. The results of these studies demonstrated that: (1) the principal phospholipids and neutral lipids of intestinal Golgi membranes, respectively, were phosphatidylcholine, phosphatidylethanolamine and sphingomyelin, and unesterified cholesterol and fatty acids; (2) the major fatty acids of Golgi membranes were palmitic (16:0), stearic (18:0), linoleic (18:2), arachidonic (20:4) and oleic (18:1) acids; (3) fluorescence polarization studies using diphenylhexatriene detected a thermotropic transition at 24-26 degrees C in Golgi membranes and liposomes prepared from lipid extracts of these membranes; (4) benzyl alcohol (25 and 50 mM) but not methyl alcohol (50 mM) significantly increased the fluidity of these membranes; and (5) at these same concentrations, benzyl alcohol was also found to increase significantly the specific activity of UDP-galactosyllactosylceramide galactosyltransferase but not CMP-acetylneuraminic acid: lactosylceramide sialyltransferase. Methyl alcohol was not found to influence either enzyme's activity in these membranes.