Curvature of the lumbar spine as a consequence of mechanical necessities in Japanese macaques trained for bipedalism

If trained to walk bipedally at a juvenile age and over periods of some months or years, Japanese monkeys gradually acquire a pronounced lordosis of the lumbar spine. This lordosis persists even in the 'normal', pronograde posture of these animals. It is due to a relative increase of the ventral lengths of the vertebral bodies. This morphological change is clearly an adaptation to the mechanical necessities of the upright body posture. Our result is in complete accordance with the development of a lordosis in human children between 1 and 5 years, as described recently by others.     

Stimulating effect of natural estrogens on proliferation of hepatocytes in adult mice

A single oral administration of natural principal estrogens, estrone (E1), 17 beta-estradiol (E2) and estriol (E3), caused active proliferation of hepatocytes of adult mouse liver. Steroid hormones tested (testosterone, progesterone and cortisone) other than estrogens were not stimulants of proliferation of hepatocytes. Among these three natural estrogens, E3 was found to be the most potent stimulant of hepatocyte proliferation and E1 was the weakest. The possible mechanism of the hepatocyte-proliferating potency of estrogens was discussed in close relationship to their stimulating effect on the reticuloendothelial system.     

Early ontogeny of Lophonectes gallus (Bothidae) from southeastern Australia

 The early ontogeny of Lophonectes gallus (Bothidae) is described based on 83 specimens (1.9–17.5 mm BL), collected from the Tasman Sea off southeastern Australia. The larvae are diagnosed by the following array of characters: vertebrae 10 + 30–31 = 40–41; one elongated dorsal fin ray and several melanophores present on gut in preflexion stage (1.9–4.7 mm BL); and spines on posterior basipterygial process, and urohyal, cleithrum, and epiotic without spines after postflexion stage (8.0–17.5 mm BL). The larvae are relatively small at metamorphosis (15–18 mm BL) compared with other bothid larvae. Received: March 22, 2001 / Revised: December 12, 2001 / Accepted: December 26, 2001     

Caenorhabditis elegans N-glycans containing a Gal-Fuc disaccharide unit linked to the innermost GlcNAc residue are recognized by C. elegans galectin LEC-6

We report a detailed structural analysis of the N-glycans of Caenorhabditis elegans recognized by C. elegans galectin LEC-6. Glycoproteins of C. elegans captured by an immobilized LEC-6 affinity adsorbent were isolated. The N-glycans of these glycoproteins were then liberated by hydrazinolysis and labeled with the fluorophore 2-aminopyridine (PA). The derived pyridylaminated (PA)-sugars were further fractionated by rechromatography on immobilized LEC-6 adsorbent and by reversed-phase high-performance liquid chromatography (HPLC). The structures of the PA-sugars thus obtained were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS/MS) in conjunction with glycosidase digestion. We confirmed that all PA-sugars having affinity for LEC-6 contain a Gal-Fuc disaccharide unit, and that this unit is bound to the innermost GlcNAc residue of the N-glycan chain. The dissociation constants of LEC-6 for these glycans were measured by frontal affinity chromatography. LEC-6 exhibited higher affinity for oligosaccharides having a Gal-Fuc unit linked to position 6 of the innermost GlcNAc residue than for those having Galbeta1-4GlcNAc units. Affinity for the former disappeared, however, following treatment with beta-galactosidase. If the glycan contained a Hex-Fuc disaccharide linked to the penultimate GlcNAc residue, the affinity would be diminished. We propose, therefore, that the galectins of C. elegans utilize the Gal-Fuc disaccharide unit for recognition instead of the Gal-GlcNAc unit that is common in vertebrates.     

Histone H3 mRNA in situ hybridization for identifying proliferating cells in human pancreas, with special reference to the ductal system

In general, the incidence of proliferating cells parallels that of carcinogenesis. We have investigated proliferating activity and phenotype expression in epithelial cells in normal tissue, mucinous metaplasia and ductal adenocarcinoma of the pancreas. Twenty-eight resected pancreases (15 cases of pancreatic ductal adenocarcinoma and 13 cases of other diseases) were examined. Formalin-fixed, paraffin-embedded tissue sections were examined for proliferating cell activity using histone H3 mRNA in situ hybridization and immunostaining for Ki-67. In the normal pancreas, the labelling indices for proliferating cells were low and no generating zone was found. The following progressive increase was found in the labelling indices: normal ductal epithelium < mucinous metaplasia without papillary hyperplasia < mucinous metaplasia with papillary hyperplasia < ductal carcinoma. In the pancreatic ductal adenocarcinomas, the S-phase fraction, as defined by the ratio H3-mRNA-labelling index/Ki-67-labelling index, increased as the degree of differentiation decreased. Mucinous metaplasia with papillary hyperplasia showed organoid differentiation toward pyloric mucosa. If used in combination with other proliferative markers on paraffin-embedded tissue sections, histone H3 mRNA in situ hybridization could open broader perspectives on the biology of cell proliferation in the pancreatic ductal system.     

Association of GM4 ganglioside with the membrane surrounding lipid droplets in shark liver

By TLC, GM4 was found to be the major ganglioside in the liver of six shark species examined: Odontaspis taurus, Negaprion brevirostris, Sphyrna lewini, Mustelus griseus, Mustelus manazo, and Prionace glauca. A detailed analysis of the glycosphingolipids (GSLs) in the liver of O. taurus (sand tiger shark) showed that it contained approximately 110 nmol of lipid-bound sialic acid per gram of wet tissue, of which 80% was GM4. By extracting the liver of O. taurus with chloroform/methanol, followed by chromatographic separation of GSLs using DEAE-Sephadex A-25 and Iatrobeads columns, we have isolated GM4 in pure form with a yield of approximately 5 mg per 100 g of wet tissue. The structures of both the sugar chain and the ceramide moiety of this GM4 were analyzed by chemical analysis, mass spectrometry, and NMR spectroscopy. Similar to GM4 isolated from other sources, 92% of fatty acids in the ceramide of this GM4 were 2-hydroxylated. However, unlike the long-chain bases found in other GSLs, the total long-chain bases in this GM4 were found to contain 43% octadecasphingenine and 50% nonadecasphingenine. Immunohistochemical analysis using a monoclonal antibody against GM4 revealed that the hepatocytes of both M. griseus (spotless smooth hound) and M. manazo (smooth hound) were filled with lipid droplets and GM4 was primarily associated with the membrane structure surrounding lipid droplets.