Absolute stereochemistry of (+)-trans-1,2-dihydroxyacenaphthene,a mammalian metabolite of acenaphthylene

A sample of (+)-trans-1,2-dihydroxyacenaphthene, a mammalian metabolite of acenaphthylene, was prepared by stereoselective partial hydrolysis of the corresponding synthetic racemic diacetate using the mold, Rhizopus nigricans. The absolute stereochemistry of the trans-diol was established as (1R,2R) by conversion to the known dimethyl (2S,3S)diacetoxysuccinate.     

Macaca fuscata develops thin enamel on lingual sides of lower incisors

Among the cercopithecids, papionins were believed to have unique lower incisors without enamel on the lingual surfaces based on analyses by light microscopy. We examined unerupted lower permanent incisors ofMacaca fuscata with scanning electron microscopy and found a lingual thin enamel layer. This seems to be the case for all papionins. Thus, all cercopithecines can be regarded to share this trait which distinguishes cercopithecines from colobines who have substantial enamel layer on the lingual sides of lower incisors. Further study will support this hypothesis. This trait produces self-sharpening chisel-like edges on lower incisors. And the adaptive significance of this chisel-like edged incisor could be understood for scraping and cutting to prepare foods for consumption.     

Emetic responses and neural activity in young musk shrews during the breast-feeding/weaning period: comparison between the high and low emetic response strains using a shaking stimulus.

The high emetic response (HER) strain and low emetic response (LER) strain of musk shrews (Suncus murinus) markedly differ in the emetic reflex in adults. However, there have been no studies on young musk shrews. We gave a shaking stimulus to young musk shrews aged 10 days or more that were obtained by mating within each strain and observed emetic responses. In the HER strain, no animal aged 10 days vomited, but vomiting was observed in 1 of 5 animals each aged 12 and 14 days, 2 of 5 animals aged 16 days, and all animals aged 18 days or more. In the LER strain, no vomiting was observed until the age of 14 days, but at the age of 16 days or more, 1 or 2 of 5 animals at each age vomited. After stimulation, activated neurons of the dorsal vagal complex and the dorsal reticular formation of the nucleus ambiguus (Amb) were examined by Fos immunohistochemistry. This morphometric study demonstrated that the numbers of Fos-positive neurons in the nucleus of the solitary tract and the dorsal reticular formation of the Amb were significantly larger in the animals that vomited in the HER strain than animals that did not vomit in the LER strain. We suggest that neurons in these regions are involved in emetic responses, as is the case in adult animals.     

Growth Analysis of Sumatran Monophyllaea, Possessing Only One Leaf Throughout Perennial Life

Abstract Growth and allometry were analyzed for populations of Monophyllaea hirtella Miq and M. horsfieldii R. Br. (Gesneriaceae), forest floor herbs that have only one cotyledonous leaf throughout life, in an equatorial rain forest in West Sumatra. Monophyllaea populations consisted of individuals of various sizes up to 30 g dry weight and 50x70 cm in leaf width and length. The relative growth rate (RGR) declined with size to an asymptotic value of 0.015–0.018 gg^-1 week^-1 for large individuals at sexual maturity (>2 g dry weight). The size-RGR relation did not differ among observations at three differen times of year and between two species in different habitals, indicating that it takes 4.6 years for seedlings to attain sexual maturity and 6.4 years to reach 10 g dry weight. Irrespective of embryonic organization of Monophyllaea , clear allometry existed among organs. Net assimilation rate was constant for juveniles and increased with size for adults. Decline of both the specific leaf area and the ratio of assimilate allocation to leaf caused the decrease of RGR with size. Reproductive allocation was 31% to reproductive organs and at most 5% to seeds in net production in a large individual of 20 g dry weight.     

Increased production of tumor necrosis factor and prostaglandin E2 by monocytes in cancer patients and its unique modulation by their plasma

Summary We investigated the role of monocytes in the production of tumor necrosis factor (TNF) and prostaglandin E₂ (PGE₂) in 77 cancer patients with malignancies of the digestive tract, using 30 normal individuals and 18 noncancer patients as controls. Monocytes were incubated with lipopolysaccharide for 20 h, and TNF production and PGE₂ production were analyzed by bioassays. Elevated levels of TNF (>512 U/ml) and PGE₂ (>8 ng/ml) production were demonstrated in many cancer patients when these factors were induced in the medium with 10% fetal bovine serum. The elevated level of TNF was seen to be restricted for the most part to patients with malignancies. Thus, 51 out of 59 cancer patients (86%), consisting of 44 primary cancer patients and 15 recurrent cancer patients, showed an increased level of TNF. In contrast, almost all of 18 postoperative cancer patients showed TNF levels comparable to those of normal individuals. Furthermore, 16 primary cancer patients were also demonstrated to have reduced levels of TNF production by monocytes after curative operation. When 10% cancer-patient plasma was added to the induction culture, TNF production by monocytes was drastically suppressed in the cancer patients. Interestingly, the same addition of plasma induced a prominent enhancement of PGE₂ production in the cancer patients. The plasma of noncancer patients did not modulate production of these factors. No TNF activity was found in the plasma of cancer patients, but such plasma did contain an increased level of PGE₂ (100–300 pg/ml). Although PGE₂ (>2ng/ml) was able to suppress TNF production by monocytes, the addition of 10% plasma PGE₂ was not enough to induce suppression. An unknown factor(s) in the plasma of cancer patients may uniquely modulate the elevated TNF and PGE₂ production in these patients.     

Receptor phenotype underlies differential response of hepatocytes and nonparenchymal cells to heparin-binding fibroblast growth factor type 1 (aFGF) and type 2 (bFGF)

Summary Heparin-binding fibroblast growth factors (HBGF) have been implicated in the regeneration of both parenchymal and nonparenchymal cells of the liver. The response to and phenotype of hepatocyte receptors for HBGF-1 (acidic fibroblast growth factor) and HBGF-2 (basic fibroblast growth factor) were compared to keratinocytes, fibroblasts, and endothelial cells. HBGF-1 stimulated DNA synthesis in hepatocytes, keratinocytes, fibroblasts, and endothelial cells whereas activity of HBGF-2 was limited to fibroblasts and endothelial cells. HBGF-2 antagonized the mitogenic activity of HBGF-1 for hepatocytes and keratinocytes. Hepatocytes and keratinocytes exhibited both high- and low-affinity, nonmatrix receptor sites for HBGF-1, but only low-affinity sites for HBGF-2. The mesenchymal cells displayed only high-affinity sites for both HBGF-1 and HBGF-2. Northern blot and immunochemical analysis revealed that the expression of HBGF receptor genesbek andflg are partitioned between normal hepatocytes and nonparenchymal cells, respectively. Expression of epithelial cell-specific, mesenchymal cell-derived HBGF-7 (keratinocyte growth factor) mRNA in regenerating liver tissue was undetectable relative to HBGF-1. The results support a multifunctional role of HBGF-1 acting through different receptor phenotypes in hepatocyte and nonparenchymal cells during liver regeneration.     

Cytokine Regulation of Nerve Growth Factor-Mediated Cholinergic Neurotrophic Activity Synthesized by Astrocytes and Fibroblasts

The neurotrophic activity of astrocytes and fibroblasts and its regulation by various cytokines were investigated. Astrocyte conditioned medium (ACM) enhanced the survival of neurons and the proliferation of astrocytes in embryonic cortical cultures grown in serum-free defined medium. However, these results were not affected by acidic fibroblast growth factor, interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF alpha), and transforming growth factor-beta 1. In contrast, ACM induced choline acetyltransferase expression in septal cholinergic neurons via nerve growth factor (NGF)-dependent and -independent mechanisms. However, neither acidic nor basic fibroblast growth factor is involved in this biological activity in ACM. The cytokines listed above mainly stimulate NGF-mediated cholinergic neurotrophic activity in ACM. A combination of IL-1 beta and TNF alpha significantly enhanced choline acetyltransferase activity in septal neurons co-cultured with astrocytes, and this effect was found to be mediated by NGF produced by activated astrocytes. Effects of astrocytes on GABAergic neurons were also examined. ACM was found to increase glutamate decarboxylase activity in neuronal cultures from septum in the presence of Ara-C. However, the cytokines did not enhance this activity in ACM. Moreover, a combination of IL-1 beta and TNF alpha had no effect on glutamate decarboxylase activity in septal neurons co-cultured with astrocytes. In a final set of experiments, cholinergic neurotrophic activity in skin-derived fibroblast conditioned medium (FCM) was examined. FCM was found to possess biological activity similar to that of ACM on septal neurons grown in serum-free defined medium with Ara-C. The cytokines also enhanced NGF-mediated cholinergic neurotrophic activity in FCM. Astrocytes and fibroblasts were found to possess NGF-type and non-NGF-type cholinergic neurotrophic activity, and various cytokines were found to regulate the NGF-type cholinergic neurotrophic activity in both types of cells. NGF produced by astrocytes and fibroblasts that are activated by cytokines is likely to be important for development and regeneration of NGF-sensitive neurons in the central and peripheral nervous systems.     

Population genetics of Japanese monkeys: III. Ancestry and differentiation of local populations

Genetic variability in local populations of the Japanese macaque (Macaca fuscata) was quantified by the proportion of polymorphic loci (P_poly) and the average heterozygosity per individual ( ) from the starch- and polyacrylamide-gel electrophoreses of blood proteins controlled by 32 independent genetic loci. P_poly averaged 13.6% and 2.1%, the values being at lower level compared with other mammalian species. Geographical distribution of the genetic variations was not uniform in the whole species but its local differentiation was remarkable. Genetic variability tended to be lower in the southern localities, especially in the southernmost island of Yaku, than in the central and northern localities. The genetic distance and the principal component analyses showed that the most divergent local populations were the population in the Shimokita peninsula at the northernmost distribution area of the species and the populations on the Yaku island at the southernmost. The most contributory loci to the genetic divergence were the PGM-II, Gc, and Hb-β, the variant allele at the first locus being concentrated in the Yaku island, in the Shimokita peninsula, and in the easternmost Boso peninsula, and the variant allele at the latter two loci having high frequencies in the Shimokita and the Izu peninsulas. The Hennigian cladistic analysis, for which the Chinese rhesus macaque (M. mulatta) was used as the outgroup, revealed that the number of presence of derived (apomorphic) alleles was conspicuously smaller in southern islet populations than in central and northern populations, whereas any areal tendency was not recognized in the number of loss of ancestral (plesiomorphic) alleles. The observed distribution pattern that the plesiomorphic variant allele at the PGM-II locus concentrated only in the peripheral (southernmost, northernmost, and easternmost) ranges of the species, would indicate, as a possibility, the occurrence of two or more waves of immigration of ancestors of the present-day Japanese macaque from the Asian continent.