Spenolimycin, a new spectinomycin-type antibiotic. III. Biological properties

Spenolimycin is a new spectinomycin-type antibiotic isolated from Streptomyces gilvospiralis sp. nov. In vitro, it was active against a wide variety of aerobic Gram-positive and Gram-negative bacteria and Neisseria gonorrhoeae. It was two to four-fold more active against N. gonorrhoeae than spectinomycin. Spenolimycin was effective in the standard mouse protection test against Escherichia coli, Klebsiella pneumoniae and Streptococcus pneumoniae.     

锡兰海木耳多糖的提取、理化性质及抗氧化活性研究

目的 从红藻锡兰海木耳(Sarcodia ceylonensis)中提取多糖,对其化学组成和理化性质进行分析,并进行体外抗氧化活性评价.方法 依次通过冷水、热水(85 ℃)和4％ NaOH溶液提取海木耳多糖;通过化学方法测定其总糖和硫酸根含量;利用PMP柱前衍生高效液相色谱法、高效凝胶渗透色谱法、红外光谱等方法对其单糖...     

Gardimycin, a new antibiotic from Actinoplanes. III. Biological properties.

The new antibiotic gardimycin has an interesting in vitro antibacterial activity against Gram-positive bacteria and Neisseria gonorrhoeae. Parenteral administration gives a high degree of protection against experimental infections in mice. It also shows some chemotherapeutic activity when given rectally.     

Sporeamicin A, a new macrolide antibiotic. III. Biological properties.

Sporeamicin A is a new erythromycin-type antibiotic isolated from a species of Saccharopolyspora. It was active in vitro against a wide variety of Gram-positive bacteria. In vitro studies indicated that the sporeamicin A was stable in the presence of human serum, although it was bound to serum proteins. Sporeamicin A was effective in the mouse protection test against Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae. Sporeamicin A attained higher plasma and tissue levels in the rat than did erythromycin stearate.     

Pholipomycin, a new member of phosphoglycolipid antibiotics. III. Biological properties.

Pholipomycin, a new member of the phosphoglycolipid antibiotics, was primarily active against gram-positive bacteria including clinically isolated resistant bacteria. It differed from other members of the antibiotic family as it also demonstrated activity against gram-negative bacteria. Pholipomycin protected mice from infection with Staphylococcus aureus and was nontoxic to mice having an LD50 (i.v.) of 600 mg/kg. Besides possessing anti-microbiol activity, pholipomycin, when administered orally, appeared to promote growth in chickens and pigs.     

Differential expression and roles of volume-activated chloride channels in control of growth of normal and cancerous nasopharyngeal epithelial cells

We have previously shown that chloride channel activities were cell cycle-dependent and were involved in cell proliferation in nasopharyngeal carcinoma cells. In this study, the expression and roles of volume-activated chloride channels in cell growth were investigated in the poorly-differentiated human nasopharyngeal carcinoma cell (CNE-2Z) and its counterpart, the normal human nasopharyngeal epithelial cell (NP69-SV40T). Consistent with growth ability, the background chloride currents recorded under isotonic condition, the volume-activated chloride currents induced by 47% hypotonic challenges and the hyponinicity-induced regulatory volume decrease (RVD) were much larger in CNE-2Z cells than in NP69-SV40T cells, suggesting the up-regulation of expression of volume-activated chloride channels in cancerous cells. This was proved by the up-regulation of ClC-3 proteins, a candidate of volume-activated chloride channels, in the cancerous cells. Functional inhibition of chloride channel activities by the chloride channel blockers, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and tamoxifen, and knock-down of ClC-3 expression by specific ClC-3 siRNA attenuated the background currents, suppressed the activation of volume-activated chloride currents, decreased the hyponinicity-induced RVD and inhibited cell growth in the cancerous and normal cells. However, the sensitivities of the cancerous cells were much higher than that of the normal cells. Our data suggest that volume-activated chloride channels play a more important role in control cell proliferation in the cancerous cells than in the normal cells; the growth of cancerous cells is more dependent on the activities of volume-activated chloride channels than that of the normal cells. ClC-3 protein may be considered as a potential tumor marker and therapeutic target for human nasopharyngeal carcinoma.     

Biological properties of a new non-steroidal anti-inflammatory drug: etoclofene.

Etoclofene, the ethoxy methyl ester of N-(2,6-dichloro-m-tolyl)anthranilic acid, showed potent anti-inflammatory, anti-pyretic and peripheral analgesic activity in several experimental models of inflammation. There was no evidence of adrenal dependence or corticoid-like effects at effective and non-toxic dose levels. Etoclofene showed a low level of toxicity and was well tolerated in animals.     

海参岩藻聚糖硫酸酯抗肿瘤转移作用研究

目的建立小鼠黑色素瘤B16细胞实验性肺转移模型,探讨海参岩藻聚糖硫酸酯(sea cucumber fu-coidan,SC-FUC)的体内抑制肿瘤肺转移作用。方法连续腹腔注射SC-FUC 26d后,检测小鼠肺转移灶数量、血清中唾液酸的含量、γ-谷氨酰转肽酶活力和肺组织中羟脯氨酸、氨基己糖、糖醛酸的含量。结果SC-FUC剂量组小鼠的肺转移灶数量显著减少(P<0.01),平均转移抑制率为65.25%,血清唾液酸含量和γ-谷氨酰转肽酶活力显著降低(P<0.01),肺组织中羟脯氨酸、氨基己糖、糖醛酸的含量显著下降(P<0.01)。结论SC-FUC能显著抑制肿瘤细胞在小鼠体内的转移和生长。     

Inhibition of cultured bovine aortic endothelial cell proliferation by sodium spirulan,a new sulfated polysaccharide isolated from Spirulina platensis

Sodium spirulan (Na-SP) is a sulfated polysaccharide isolated from the blue-green alga Spirulina platensis, which consists of two types of disaccharide repeating units, O-hexuronosyl-rhamnose (aldobiuronic acid) and O-rhamnosyl-3-O-methylrhamnose (acofriose) with sulfate groups, other minor saccharides and sodium ion. Vascular endothelial cells are present on the inner surface of blood vessels in a monolayer and have anticoagulant properties. To address the question whether Na-SP influences the maintenance of endothelial cell monolayers, we investigated the proliferation of cultured bovine aortic endothelial cells treated with Na-SP. It was found that Na-SP has an inhibitory activity on endothelial cell proliferation accompanied with suppression of whole protein synthesis but without non-specific cell damage. The inhibitory activity of Na-SP was the strongest when compared to that of heparan sulfate, heparin, dextran sulfate, dermatan sulfate, chondroitin sulfate A/C and hyaluronan. Furthermore, it was shown that the inhibitory activity of Na-SP disappeared by either desulfation or depolymerization. The present data suggest that Na-SP is a unique sulfated polysaccharide that strongly inhibits vascular endothelial cell proliferation, and the inhibitory activity requires polymerization of sulfated O-rhamnosyl-acofriose repeating units.     

The disposition of saquinavir in normal and P-glycoprotein deficient mice, rats, and in cultured cells.

Protease inhibitors are very effective in treating patients infected with HIV. However, many drugs in this class penetrate poorly into the central nervous system (CNS) and may permit this site to be a sanctuary from which resistant virus can emerge. Previous studies have shown that the protease inhibitor saquinavir (SQV) interacts with the multidrug transport system, P-glycoprotein (P-gp), expressed in epithelial cells in the gut mucosa and at the blood-brain barrier, and thus might affect both the oral absorption and the penetration of SQV into the CNS. To determine whether SQV is a substrate for P-gp, its uptake was determined in cancer cells, which do (Dx5) and do not (MES-SA) express P-gp. The distribution of SQV between brain tissue and plasma was also investigated in rats and in normal and P-gp-deficient mdr1a(-/-) mice. The distribution ratio of SQV in plasma:brain:cerebrospinal fluid was approximately 100:10:0.2 in rats. The accumulation of SQV was enhanced in MES-SA cells (P-gp-negative) versus Dx5 cells (P-gp-positive). Bolus i.v. injection of [(14)C]SQV (2 and 5 mg/kg) into mdr1a(-/-) and normal mice (n = 3 or 4) resulted in 3-fold higher radioactivity in brains from mdr1a(-/-) mice. Similarly, oral administration of [(14)C]SQV (500 mg/kg) resulted in a 5-fold increase in systemic exposure and a 10-fold increase in brain levels in mdr1a(-/-) mice. These data demonstrate that saquinavir is a substrate for P-gp and that this transport system may play a role in limiting oral absorption and CNS exposure to this protease inhibitor.     

WF14861, a new cathepsins B and L inhibitor produced by Colletotrichum sp. II. Biological properties.

WF14861, 3-(N-(1-(N-(4-aminobutyl)-N-(3-aminopropyl)carbamoyl)-2-(4-hydroxyphenyl )ethyl)carbamoyl)oxirane-2-carboxylic acid, was obtained from the culture mycelium of Colletotrichum sp. as a novel cathepsins B and L inhibitor. WF14861 also showed inhibitory activities against bone derived crude protease and other cysteine proteases in vitro. The compound ameliorated the tissue damage and the bone destruction models of low-calcium-diet-fed mouse and adjuvant arthritis rat model.     

"Mucin types" in normal and neoplastic colonic goblet cells: a mucin histochemical study.

Goblet cells in normal colon mucosa from 100 individuals histochemically showed two major "mucin types" in sialic acid composition. One type revealed mixed reactivities for N-acetyl-neuraminic acid (NANA, abbreviated C0), 7-O- acylated NANA (C7) and 9-O-acylated NANA (C9), and represented 25% of the individuals examined. The other type of mucin, seen in 69% of the cases, exhibited reactivity for 8-O-acylated NANA or pluri-O-acylated NANA (C8). C0 and C8 were observed simultaneously in 5% of the individuals. In addition, 8% displayed a mosaic pattern in which isolated "blue" crypts containing sialic acids of the C0 + C7 + C9 type were detected in the "red" colonic mucosa, which was predominantly C8. Little correlation was found between the mucin types and their site in the colon, or with the age, sex, ABO blood groups and degree of sulphation. O-acylated NANA was also observed, though reduced in amount, in all 22 colonic adenocarcinomas in which evaluable numbers of neoplastic goblet cells were found. The mucin types in colon cancer were fundamentally indistinguishable from those seen in the surrounding noncancerous colonic mucosa.     

Cardiovascular properties of MS-857, a new and potent cardiotonic agent, on normal and failing hearts

The cardiovascular properties of MS-857 [4-acetyl-1-methyl-7-(4-pyridyl)-5,6,7,8-tetrahydro-3(2H)-isoquinolinone ], a novel cardiotonic agent, were investigated in anesthetized and conscious dogs. MS-857 (1-100 micrograms/kg i.v.) produced a significant and dose-dependent increase in cardiac contractility with relatively small changes in heart rate and blood pressure. This indicates a sizable separation between positive inotropic and other effects of MS-857. Oral administration of MS-857 to conscious dogs (0.1-1 mg/kg) also produced a sustained increase in cardiac contractility in a dose-dependent manner. The total duration of action was longer than 7 h at a dose of 1 mg/kg p.o. There occurred no arrhythmias and no changes in animal behavior. After chronic oral administration, MS-857 completely retained its activities, indicating the lack of tachyphylaxis. In the acute heart failure models induced by either propranolol or pentobarbital, MS-857 reversed the cardiac depressant effects of these drugs. Moreover, MS-857 also significantly improved the pentobarbital-induced heart failure in the heart-lung preparation. MS-857 did not inhibit the Na+, K+-ATPase, but inhibited the phosphodiesterase (PDE) III selectively, both of which were prepared from the dog ventricular muscle. Thus, MS-857 can be characterized as a potent nonsympathomimetic, nonglycoside cardiotonic drug with a selective inhibitory activity on PDE III. The cardiovascular properties revealed by this study strongly suggest that MS-857 will exert a beneficial effect in the treatment of congestive heart failure.     

Biological properties and clinical application of propolis. IV. The action of ethanol extract of propolis (EEP) on cells cultured in vitro

An increase of total cell number was shown in the cell culture in vitro under the influence of ethanol extract of propolis (EEP). Addition of EEP to the nutrient medium of the cells caused a strong activation of mitoses. Besides, distinctly intensified metabolism of these cells expressed by a strong activation of NADH2-reductase was also observed.     

The effect of sulphasalazine and its metabolites on the colonic epithelial Caco-2 cells

Sulphaselazine (SAS) is a drug commonly used to treat patients suffering from chronic inflammatory states such as inflammatory bowel diseases. It was shown that besides bacteriostatic, antiinflammatory and immunosuppressive activity of this drug, the risk of neoplastic changes in the colon and rectum was substantially diminished during ulcerative colitis therapy with SAS. In the present study the effects of SAS and its main metabolites--sulphapyridine (SP) and 5-aminosalicylic acid (5-ASA) on colon adenocarcinoma Caco-2 cells viability and proliferation was evaluated. Significant inhibitory impact of SAS was observed already at 1 mM concentration whereas 5-ASA and SP impaired cellular growth when used at 5 mM concentration. 5 mM SAS exerted a strong cytotoxic effect on Caco-2 cells resulting in their necrotic death. The inhibition of cellular proliferation and the cytotoxic effects of SAS and its metabolites (5-ASA and SP) on the colonic carcinoma cells (Caco-2) confirm the suggestions that these compounds at appropriate concentrations may reduce the risk of neoplastic changes frequently initiated by prolonged inflammatory states.     

Biological effects of desert dust in respiratory epithelial cells and a murine model

Abstract

As a result of the challenge of recent dust storms to public health, we tested the postulate that desert dust collected in the southwestern United States imparts a biological effect in respiratory epithelial cells and an animal model. Two samples of surface sediment were collected from separate dust sources in northeastern Arizona. Analysis of the PM₂₀ fraction demonstrated that the majority of both dust samples were quartz and clay minerals (total SiO₂ of 52 and 57%). Using respiratory epithelial and monocytic cell lines, the two desert dusts increased oxidant generation, measured by Amplex Red fluorescence, along with carbon black (a control particle), silica, and NIST 1649 (an ambient air pollution particle). Cell oxidant generation was greatest following exposures to silica and the desert dusts. Similarly, changes in RNA for superoxide dismutase-1, heme oxygenase-1, and cyclooxygenase-2 were also greatest after silica and the desert dusts supporting an oxidative stress after cell exposure. Silica, desert dusts, and the ambient air pollution particle NIST 1649 demonstrated a capacity to activate the p38 and ERK1/2 pathways and release pro-inflammatory mediators. Mice, instilled with the same particles, showed the greatest lavage concentrations of pro-inflammatory mediators, neutrophils, and lung injury following silica and desert dusts. We conclude that, comparable to other particles, desert dusts have a capacity to (1) influence oxidative stress and release of pro-inflammatory mediators in respiratory epithelial cells and (2) provoke an inflammatory injury in the lower respiratory tract of an animal model. The biological effects of desert dusts approximated those of silica.