Production of new anthracycline antibiotics by microbial 4-O-methylation using a specific daunorubicin-negative mutant

Microbial 4-O-methylation using a specific daunorubicin-blocked, nonproducing mutant provided the new anthracycline antibiotics 4-O-methylbetaclamycin T, 4-O-methylyellamycin A and 4-O-methyl-13-hydroxyoxaunomycin, from which 4-O-methyloxaunomycin and 4-O-methyl-6-deoxyoxaunomycin were then prepared by further photochemical N-demethylation. Antitumor activities in vitro and in vivo against L1210 cells were compared with those of their 4-O-demethyl derivatives. It was found that all the 4-O-methyl derivatives had a markedly reduced cytotoxicity in vitro as compared with the 4-O-demethyl compounds. However, some of them were endowed with a significantly improved antitumor activity in vivo.

Cytomegalic inclusion disease presenting acute intrahepatic cholestasis

An 83-year-old man suffering from pulmonary emphysema was admitted to our hospital because of jaundice. He was diagnosed as acute intrahepatic cholestasis but the etiology could not be determined during the treatment period. In spite of treatment, the jaundice worsened progressively without any elevation in serum transaminase, and he died of respiratory failure 58 days later. An autopsy revealed a generalized cytomegalic inclusion disease, predominantly in the biliary tracts, liver and lungs. This is a rare case of cytomegalic inclusion disease presenting acute intrahepatic cholestasis without any elevation of transaminase during the clinical course.

Granulovacuolar degeneration in the hippocampal cortex of aging and demented patients--a quantitative study

The occurrence and topographic analysis of granulovacuolar degeneration (GVD) in the hippocampal cortex of mentally normal controls (75 cases) and patients with Alzheimer's dementia (AD; 17 cases which included Alzheimer's disease and senile dementia of Alzheimer type), multi-infarct dementia (MID; 16 cases), Pick's disease (PD; 5 cases) and atypical dementia [5 cases; non-Alzheimer, non-Pick dementia with Fahr's syndrome (NANPDF)] were investigated. GVD was rarely found in control cases below the age of 60 years. In elderly normal brains, the statistically most representative ranking order of predilection for GVD (in decreasing severity) was: in the 60 s, CA1 > prosubiculum > CA2 (no GVD was found in the CA3 and CA4); in the 70 s, CA1 > prosubiculum > CA2 > CA3 > CA4; in the 80 s, CA1 > prosubiculum > CA2 > CA3 > CA4; in the 90 s, CA1 > prosubiculum > CA2 > CA3 > CA4. In the brains of demented patients, the rank order for GVD was: for AD, CA1 > CA2 > CA3 > prosubiculum > CA4; for MID, CA1 > prosubiculum > CA2 > CA3 > CA4; for PD, CA1 > CA2 > CA3 > prosubiculum > CA4; and for atypical dementia (NANPDF), CA1 > CA2 > prosubiculum > CA3 > CA4. The similarity of the predilection to ranking order was noted both in normal aged subjects and in MID as well as both in AD and in PD.(ABSTRACT TRUNCATED AT 250 WORDS)

Postnatal growth curves of very low birthweight Japanese infants

To construct standard growth curves for Japanese infants of very low birthweight, longitudinal data provided by 47 neonatal centers in Japan were reviewed. Data were collected on the growth of infants admitted to those units during 1986 and 1987 and who survived beyond 3 years of age. A total of 379 singleton infants, who were free of neurological sequelae and appropriate for gestational age, were enrolled. Those whose birthweights were more than 600 g and less than 1,500 g were grouped into nine weight categories separated by increments of 100 g. Data on the increase in weight and head circumference were compiled and analyzed until more than half the infants in each weight category had been discharged from each site. Growth curves of bodyweight and head circumference in the nine groups were constructed using polynomial regression analysis to define the curve of best fit. With increasing prematurity, significant trends of greater weight loss (P < 0.05), longer time to reach the lowest weight (P < 0.01) and a longer time to regain birthweight (P < 0.01) were observed. In addition, there was a significantly higher incidence of chronic lung disease in such groups (P < 0.0001). Growth curves were characterized by the average clinical profiles in each of the nine groups. We believe that these data will be useful in evaluating the growth of very low birthweight infants being cared for in modern neonatal intensive care units in Japan.

Preparation of 13C and 15N labeled bellenamine and its degradation products

A streptomyces metabolite, bellenamine, has been converted into D-beta-lysinamide and cyclized bellenamine in an acidic solution at 75 degrees C. The structure of the new cyclized compound was assigned as (R)-6-(3-aminopropyl)-1,3-diazacyclohexan-4-one by spectral analyses. [1-13C, Amide, 1'-15N2]bellenamine, which has been isolated from the culture by feeding both L-[1-13C]lysine and [15NH4]2SO4 to a synthetic medium, was degraded under acidic condition to obtain the stable isotope labeled D-beta-lysine, D-beta-lysinamide and cyclized bellenamine. These labeled compounds were analyzed by 13C and 15N NMR spectra, and will be used for the biosynthetic study on bellenamine.

Dethymicin, a novel immunosuppressant isolated from an Amycolatopsis. Fermentation, isolation, physico-chemical properties and biological activities

In the course of screening for immunomodulators inhibiting the mixed lymphocyte culture reaction (MLCR), we found a novel immunosuppressant, dethymicin in mycelium of Amycolatopsis mediterranei MI710-51F6. From physico-chemical properties and biological activity it is different from immunosuppressants produced by microorganisms such as cyclosporins, FK506 and rapamycin. It inhibited immune responses in vitro and in vivo, and prolonged skin allograft in rats.

Effects of hypoxia, hyperoxia and hypercapnia on graded cerebral ischemic responses in rabbits

This study was designed to determine how several factors interact to modify the cerebral ischemic pressor response (CIR) in anesthetized rabbits. After the carotid sinus and aortic nerves were bilaterally sectioned, blood flow through the left internal carotid artery (ICF), which was surgically restricted as the sole route of blood supply to the brain, was reduced by a servo-controller during ventilation with room air, and 8% and 90% O2 and 2 and 5% CO2 gas mixtures. Blood flow (MBF), tissue PO2, PCO2, and interstitial pH were measured in the rostral ventrolateral medulla. Internal carotid arterial pressure, tissue PO2, and MBF decreased proportionately as ICF decreased in the range from 4 to 0 ml/min. Hypoxia significantly increased the rise in renal nerve activity (RNA) and CIR caused by cerebral ischemia, while hyperoxia significantly decreased them. Hypercapnia had almost no influence on the increases in RNA and mean arterial pressure produced by cerebral ischemia. CIR showed a much higher correlation with changes in tissue PO2 than with the other factors. We examined how these factors interact to modify CIR and found that central hypoxia is the main factor in producing CIR.

In vitro effects of glycosylated insulin and glucagon in perfused liver of the rat

Using perfused liver of the rat, the hepatic uptake of glycosylated insulin (GI) and glucagon (GG) and its effects on hepatic glucose output were investigated. Insulin and glucagon were glycosylated in ambient high glucose concentration, and GI80 or GG80 (insulin or glucagon incubated with 0.08% glucose), GI350 or GG350 (incubated with 0.35% glucose), and GI1000 or GG1000 (incubated with 1% glucose) were prepared. The liver was perfused with the medium containing 1000 microU/ml insulin and 200 pg/ml glucagon or 200 microU/ml insulin and 1000 pg/ml glucagon. The fractional uptake of insulin or glucagon by perfused liver was not significantly altered by the glycosylation. In the liver perfused with 1000 microU/ml insulin and 200 pg/ml glucagon, glucose output was not changed by the glycosylation of the hormones, while in the liver perfused with 200 microU/ml insulin and 1000 pg/ml glucagon, GI1000 reduced its biological activity, as reflected by insulin-mediated decrease in glucose output. These results suggest that in the liver insulin incubated with markedly high concentration of glucose reduces its biological activity at a physiological concentration in the presence of high concentration of glucagon.

Biosynthesis of bellenamine by Streptomyces nashvillensis using stable isotope labeled compounds

The biosynthesis of bellenamine was studied by feeding 13C and 15N labeled precursors to the synthetic medium culture of Streptomyces nashvillensis MD743-GF4. The high degree of incorporation of D-[1-13C]beta-lysine indicated that it is a direct intermediate, while supplemented L-beta-lysine repressed the production of bellenamine. [2-13C]Glycine was well incorporated into the C-1' of the open-chain aldoaminal structure. All four nitrogens of bellenamine were derived from [15NH4]2SO4 present in the synthetic medium. In the addition of L-lysine and glycine, [15NH4]2SO4 was highly incorporated into CONH. The feeding experiments of 13C labeled acetates suggested that the D-beta-lysine moiety was derived from L-lysine by catalysis of a new 2,3-aminomutase, and L-lysine was biosynthesized from acetates via the TCA cycle and diaminopimelic acid pathway.

Synthesis and activity of 3-(isoxazolin-5-yl)- and 3-(isoxazol-4-yl)cephalosporins

The 1,3-dipolar cycloaddition of nitrile oxide with 3-vinylcephalosporin provided diastereomeric isomers of 3-(isoxazolin-5-yl)cephalosporin. Cycloaddition of nitrile oxide with 3-(dimethylamino-vinyl)cephalosporin gave 3-(isoxazol-4-yl)cephalosporin. These semisynthetic cephalosporins with an aminothiazole in the C-7 side chain showed moderate antibacterial activities.

Cloning and sequencing of the cDNA encoding tyrosinase of the Japanese pond frog, Rana nigromaculata

We cloned and sequenced the cDNA encoding tyrosinase (TYN) of the Japanese pond frog, Rana nigromaculata. The 3511-bp cDNA contained a 54-bp 5'-noncoding region, a 1596-bp open reading frame encoding TYN of 532 amino acids (aa), and a 1861-bp 3'-noncoding region. The aa sequence of frog TYN predicted from the cDNA sequence was homologous to that of mouse and human TYNs. The aa sequence including the copper-binding domain, which is likely the active center of TYN, was highly conserved among these three species and Neurospora crassa, Streptomyces antibioticus, and S. glaucescens. The frog TYN also contains possible glycosylation sites and conserved Cys at sites similar to those in the mouse and human TYNs. There are two hydrophobic regions at the N-terminus and near the C-terminus, which are likely the signal (leader) peptide and a transmembrane domain, respectively.

Holding power and reinforcement of cancellous screws in human bone

The authors report an in vitro biomechanical evaluation of a biodegradable material that might be used for the reinforcement of surgical screws in fractures involving severely osteoporotic bone. The material is a particulate composite with a matrix phase consisting of a hydrolyzable prepolymer, polypropylene fumarate (PPF), crosslinked with methacrylate monomer, and a particulate phase consisting of tricalcium phosphate and calcium carbonate. Pullout force and stripping load of cancellous screws were determined along with screw pullout force before and after reinforcement with either polymethylmethacrylate (PMMA) or PPF composite. Pullout force was moderately correlated (R2 = 0.59) with apparent density by a power law relationship of the form 0.065p1.37-1.77. Stripping load was strongly correlated (R2 = 0.91) with apparent density by a power law of the form 0.13p1.35-93.8. Mean pullout force before and after reinforcement with PMMA was 382 +/- 100 N (mean +/- standard deviation) and 879 +/- 315 N, respectively. Mean pullout force before and after reinforcement with PPF composite was 571 +/- 294 N and 829 +/- 354 N, respectively. Although the increase in pullout force with cement reinforcement was highly significant in both cases, the magnitude of the increase did not depend on the type of cement. Thus PPF seems to provide reinforcement that is equivalent to that provided by PMMA.

Progressive supranuclear palsy with widespread cerebral lesions

A 51-year-old woman with no history of any familial neurological diseases initially presented with numbness in her extremities, slowing of movements, comprehension deficit, memory disturbance, dyscalculia, muscle rigidity, hyperreflexia, Parkinsonian gait, increasing disorientation, left-right disturbance, finger agnosia, alexia, acalculia, apraxia, aspontaneity, euphoria, gait disturbance, aphasia, echolalia, and in the terminal stage, mutism, contracture of lower extremities and cachexia. She died of bronchopneumonia at the age of 55. The brain showed widespread cerebral lesions, consisting of nerve cell loss and neurofibrillary tangles in the frontal, parietal and occipital cortex, demyelination and gliosis in the frontal, parietal and occipital subcortical white matter in addition to the typical pathological findings of progressive supranuclear palsy (PSP): severe neuronal loss with gliosis and neurofibrillary tangles (NFTs) in the subthalamic nucleus, globus pallidus and substantia nigra. In conclusion, we present a case of PSP with unusual clinical features (extrapyramidal signs, frontal and parietal lobe syndromes without ophthalmoplegia) and neuropathologically widespread cerebral lesions in addition to the typical pathological findings of PSP. The differential diagnosis of PSP and Alzheimer's disease and other degenerative disorders is discussed.

Presence of amelanotic melanocytes within the outer root sheath in senile white hair

In order to determine whether amelanotic melanocytes are present in senile white hair, we attempted to detect tyrosinase mRNA and its protein using in situ hybridization and immunohistochemical staining. Specifically stained cells containing tyrosinase mRNA or its protein were detected by each technique in 7/23 (30.4%) or 4/14 (28.6%) senile white hairs, respectively. These cells were located in the outer root sheath between the hair-bulb and the infundibulum. Silver staining was used to determine whether melanin was present within the outer root sheath of the senile white hair. Because none of the 21 white hairs tested showed specific staining within the outer root sheath, the absence of melanin was confirmed. Thus our results suggest the presence of amelanotic melanocytes within the outer root sheath of senile white hair.

Conserved regulatory mechanisms of tyrosinase genes in mice and humans

In vertebrates, melanin production is restricted to pigment cells. This cell type-specific melanogenesis is considered to involve cell type-specific expression of the tyrosinase gene. Recently, there have been several reports that sequences in the 5' flanking region of the mouse tyrosinase gene are responsible for cell type-specific expression of the transgene in mice. As the first step in the study of the evolution of the regulatory mechanisms for tyrosinase gene function in vertebrates, we constructed a fused gene, hg-Tyrs-J, which includes a 1.0-kb 5' flanking sequence of the human tyrosinase gene fused with mouse tyrosinase cDNA. By introducing the fused gene into fertilized eggs of albino mice, we obtained two mice that exhibited pigmentation in the skin and eyes and established a transgenic line from one of them. Further analyses revealed that the transgene was expressed cell type-specifically in these transgenic mice. We conclude, therefore, that the 1.0 kb 5' upstream region of the human tyrosinase gene contains conserved cis-elements essential for cell type-specific expression of the tyrosinase genes in mice and humans. Results of our study may provide a clue to elucidate the evolutionary process of regulatory mechanisms of the tyrosinase gene.

Agonist- and subunit-dependent potentiation of glutamate receptors by a nootropic drug aniracetam

GluR1 and GluR2 cDNAs encoding non-NMDA subtypes of glutamate receptor were isolated from a rat brain cDNA library by Boulter et al. (Science, 249 (1990) 1033-1037). Functional receptors activated by kainate, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and glutamate were expressed in Xenopus oocytes injected with GluR1, GluR2 or a mixture of GluR1 and GluR2 RNAs. In GluR1-expressed oocytes, 1 mM aniracetam potentiated AMPA-induced currents by 99 +/- 10% (mean +/- S.E.M., n = 5) and glutamate-induced currents by 140 +/- 8% (n = 4), but little affected kainate-induced currents. Aniracetam was effective from a concentration of 0.1 mM, and it exhibited more conspicuous effects with the increase of the dose. In oocytes injected with GluR1 plus GluR2 RNAs, aniracetam more markedly potentiated current responses to AMPA and glutamate than those in oocytes injected with GluR1 RNA alone. For example, 1 mM aniracetam potentiated AMPA-induced currents by 396 +/- 76% (n = 4) and glutamate-induced currents by 970 +/- 65% (n = 5) in oocytes injected with 10% GluR1 and 90% GluR2 RNAs. In these oocytes, however, the potentiation of kainate-induced currents by 1 mM aniracetam was only 8 +/- 5% (n = 4). Thus, we conclude that the potentiation of the AMPA/kainate receptor by aniracetam depends on both species of agonists and subunit composition of the receptor.

Enhancement by ubenimex (bestatin) of host resistance to Candida albicans infection

Ubenimex is a low molecular weight microbial metabolite which has been demonstrated to have antitumor and immunomodulatory activities. In this study, the protective effect of ubenimex on Candida albicans infection was investigated in normal and immunosuppressed mice. In normal mice, treatment with ubenimex at 0.5, 5 and 25 mg/kg for 5 days prior to infection prolonged survival time in a dose-dependent manner. In immunosuppressed mice treated with a single dose of cyclophosphamide 4 days prior to infection, ubenimex treatment at 5 mg/kg for 5 days significantly increased the number of survivors. Ubenimex-treated mice had a significant increase in number of peritoneal exudate cells with neutrophils as well as enhanced functions, including phagocytosis and active oxygen production. These results suggest the potential usefulness of ubenimex as a prophylactic agent for the management of patients with opportunistic fungal infections.

Phylogeny of regulatory regions of vertebrate tyrosinase genes

Highly homologous DNA elements were found to be shared by the upstream regions of the mouse tyrosinase and tyrosinase related protein (TRP-1) genes. Several nuclear proteins were shown to bind to both of these upstream regions. Shared homologous DNA elements were also found in the 5' flanking sequences of Japanese quail and snapping turtle tyrosinase genes. Shared homologous nucleotide sequences were found to be scattered like an archipelago in the 5' upstream regions of mouse and human tyrosinase genes. Comparisons between Japanese quail and snapping turtle tyrosinase genes gave similar results. On the contrary, mammalian (mouse and human) and nonmammalian (quail and snapping turtle) tyrosinase genes did not show significant homology in their 5' upstream regions. In contrast, coding sequences in the first exons of vertebrate tyrosinase genes and their deduced amino acid sequences were found to be highly conserved except for their putative leader sequence-coding regions.

Production of bellenamine and new metabolites in a synthetic medium

A streptomyces antibiotic, bellenamine has been produced in a simple synthetic medium consisting of D-galactose, dextrin, ammonium sulfate and calcium carbonate. Three new minor metabolites, N-(aminomethyl)succinamic acid, 1'-N-acetylbellenamine and D-beta-lysinamide have been isolated from the synthetic medium culture. They showed no antibiotic activity.

[Imported parasitic diseases--recent epidemiology and progress in the chemotherapy]

Imported parasitic diseases have been increasingly important in basic and clinical medicine in developed countries, as the number of travellers in developing countries, where numerous kinds of parasitic diseases are highly endemic, have been increasing. Recent epidemiologic investigation demonstrated that malaria, amebiasis, trypanosomiasis, leishmaniasis and cysticercosis seemed important as judged from the number of infected individuals, primarily Japanese travellers. Although these parasitic diseases pose some serious medical problems, establishment of the effective chemotherapeutic strategy is of urgent significance. In this respect, activities of the Research Group of Development of Chemotherapeutic Agents against Tropical Parasitic Diseases supported by the Japanese Ministry of Health and Welfare appear to be important to keep appropriate drugs in Japan.

Expression of tyrosinase gene in transgenic albino mice: the heritable patterned coat colors

To elucidate the regulatory mechanism for tyrosinase gene expression in vivo, we microinjected a mouse tyrosinase minigene, mg-Tyrs-J, into the fertilized eggs of BALB/c albino mice. As a result, we obtained six pigmented founder mice that exhibited non-standard coat color variations as well as the wild-type phenotype. These founder mice were subsequently crossed with BALB/c albino mice to establish the transgenic lines. As a consequence, two primary lines and five sublines have been obtained from four of the six founder mice. We found that not only uniformly pigmented phenotypes but also patterned phenotypes were inherited by their descendants. The possible underlying mechanism of the patterned phenotypes is discussed.

The expression of mouse tyrosinase in chick cells in vitro and in vivo when controlled by a constitutive promoter

Virally introduced mouse tyrosinase expression was checked both in vitro and in vivo in chicken cells and tissues. The results indicate that a constitutive promoter is able to express mouse tyrosinase in a variety of cells and tissues both in vitro and in vivo. Tyrosinase expression is marked by pigment production in situ, which is visible at macroscopic as well as microscopic levels without the use of substrates. It is concluded that tyrosinase can be a valuable marker for tracking gene insertion since it is spontaneously expressed. The expression of tyrosinase in some cells and tissues has a detrimental effect, however, and should be controlled by tissue-specific promoters.

Expression and transmission of wild-type pigmentation in the skin of transgenic orange-colored variants of medaka (Oryzias latipes) bearing the gene for mouse tyrosinase

Transgenic fish carrying a reconstructed mouse tyrosinase gene, mg-Tyrs-J, were produced by microinjecting the gene into the oocyte nucleus of an orange-colored variant of medaka (Oryzias latipes). Of 64 oocytes microinjected and subsequently inseminated, 13 embryos developed normally beyond hatching and three of them exhibited brown skin pigmentation in the adult as was commonly observed in the wild type of this species. Light and electron microscopic examination disclosed a ubiquitous distribution of typical melanophores in the skin of these transgenic fish. Judging from their population density and distribution pattern, it was presumed that melanogenesis in these fish was elicited in amelanotic melanophores that resided in the skin of the orange-colored fish of this variant. Immunofluorescence with use of the anti-mouse tyrosinase antiserum lacking reactivity to medaka tyrosinase clearly disclosed that the gene introduced was expressed in the melanophores of transgenic fish. Crosses of female transgenic fish and males from an orange-colored variant yielded offspring exhibiting wild-type or orange-colored pigmentation in a ratio of 1:1, thus implying that mg-Tyrs-J integrated into the medaka genome behaves like a dominant gene. Little melanogenesis was observed in xanthophores, leucophores and iridophores in transgenic fish, suggesting possible specificity in recognition of teleostean cell types (i.e., melanophores) by the regulatory region of the mouse tyrosinase gene.