Decreased mortality of Norman murine sarcoma in mice treated with the immunomodulator, Acemannan

An extract from the parenchyma of Aloe barbadensis Miller shown to contain long chain polydispersed beta (1,4)-linked mannan polymers with random O-acetyl groups (acemannan, Carrisyn) was found to initiate the phagocyte production of monokines that supported antibody dependent cellular cytotoxicity and stimulated blastogenesis in thymocytes. Acemannan, in both enriched and highly purified forms, was administered intraperitoneally to female CFW mice into which murine sarcoma cells had been subcutaneously implanted. The rapidly growing, highly malignant and invasive sarcoma grew in 100% of implanted control animals, resulting in mortality in 20 to 46 days, dependent on the number of cells implanted. Approximately 40% of animals treated with acemannan at the time of tumor cell implantation (1.5 x 10(6) cells) survived. Tumors in acemannan-treated animals exhibited vascular congestion, edema, polymorphonuclear leukocyte infiltration, and central necrosing foci with hemorrhage and peripheral fibrosis. The data indicate that in vivo treatment of peritoneal macrophages stimulates the macrophage production of monokines, including interleukin-1 and tumor necrosis factor. The data further indicate that sarcomas in animals treated i.p. with acemannan at the time of tumor cell implantation were infiltrated by immune system cells, became necrotic, and regressed. The combined data suggest that acemannan-stimulated synthesis of monokines resulted in the initiation of immune attack, necrosis, and regression of implanted sarcomas in mice.     

Effects of dideoxyforskolin on proteoglycan synthesis and structure in embryonic chick chondrocyte cultures

1,9-Dideoxyforskolin inhibits proteoglycan synthesis and xyloside-initiated glycosaminoglycan (GAG) synthesis in chick embryo chondrocytes. Dideoxyforskolin does not affect the length of xyloside-initiated GAG chains secreted into the medium but chains from the dense proteoglycan secreted into the medium appear slightly longer. Incorporation of labeled serine into the dense proteoglycan and subsequent digestion with Pronase revealed a dramatic decrease in percent of total radioactivity associated with GAG chains in the proteoglyean from cultures treated with forskolin or dideoxyforskolin. These observations suggest that these diterpenes have a specific inhibitory effect on chain initiation reactions and thus may be useful tools in the study of proteoglycan synthesis and processing.     

A common sequence in the inverted terminal repetitions of human and avian adenoviruses

The termini of the avian chick embryo lethal orphan (CELO) virus DNA have been sequenced. The results revealed a 63-bp-long inverted terminal repetition (ITR) which shared the sequence ATAATA with all adenovirus termini, thus far analyzed. The CELO virus ITR differed from those of the mammalian adenoviruses in two major aspects: (i) it is not a perfect duplication; (ii) it begins with a 5'-guanylic acid residue instead of the cytidylic acid normally observed in adenoviruses.     

Improved high-performance liquid chromatography of the new antineoplastic agents bisantrene and mitoxantrone

Bisantrene and mitoxantrone are two new anthracene derivatives which have shown significant antitumor activity against a wide variety of animal tumors and in human phase I and II clinical trials. We have developed a rapid, simple and sensitive sample cleanup procedure and high-performance liquid chromatographic (HPLC) assay for both drugs. This method uses a commercially available mini-cartridge with C₁₈ reversed-phase packing to isolate the drugs from the biological matrix prior to HPLC. For both drugs the average recovery of the assay was 98 ± 6% with a coefficient of variation (C.V.) of less than 7%. Using this new method our assay sensitivity has improved to less than 10 ng/ml for bisantrene and 1 ng/ml for mitoxantrone, allowing us to document a prologned terminal phase plasma half-life for both bisantrene and mitoxantrone. Equilibrium dialysis studies showed that both drugs are highly protein bound. Mitoxantrone appears less stable in human plasma than bisantrene. Recoveries from plasma after a 24-h incubation at 25 and 37°C were 40 and 20% for mitoxantrone and 90 and 85% for bisantrene, respectively. Addition of ascorbic acid prior to incubation of mitoxantrone in human plasma at 37°C resulted in less than a 10% decrease in the latter's concentration over a 24-h period. To maintain sample integrity, all plasma samples should be fortified with ascorbic acid and kept frozen prior to analyses.     

Thymic cell migration in the subnodular spaces of draining lymph nodes of rats

Little is known about the pathway of possible lymphocyte traffic in the nodules (germinal centers) of the node. Observations reported here indicate the involvement of the subnodular spaces. These spaces, which constitute the inner limit of the nodules, are contiguous to the perivascular channels of the postcapillary venules which partially encircle each nodule. Twelve hours after a local transfer of labeled thymic cells, they were observed in the subnodular spaces and in the perivascular channels of the draining nodes. It is proposed that the spaces and the channels provide a pathway for the rapid migration of lymphocytes entering a node via the afferent lymph and, probably, carrying an immunogenic information. The pathway would permit these cells to transmit the information rapidly to the appropriate cell population(s) of a node draining a tissue undergoing an immunological process.     

NEUROSECRETORY CELL PROTEIN METABOLISM IN THE LAND SNAIL,OTALA LACTEA

—Protein synthesis in an identified molluscan neurosecretory cell of the land snail, Otala lactea was examined using three different types of polyacrylamide gel electrophoresis. Cells taken from active snails synthesized specific low molecular weight proteins while those from aestivated snails did not. Most of the newly synthesized low molecular weight proteins in the active snails were lost from the cell body when the preparations was chased for 19 h in label-free enriched medium in the presence of anisomycin, an inhibitor of protein synthesis. If colchicine, a blocker of axonal transport, was included in the chase medium, the proteins present following a pulse were largely replaced by smaller molecular weight species. The results suggest that specific low molecular weight proteins are converted to smaller species and then transported from the cell body.     

基于SPEI指数的淮河流域干旱时空演变特征及影响研究

运用淮河流域149个气象站1962—2016年逐日气温、降水资料以及历史旱情资料,基于SPEI、EOF和M-K等方法分析淮河流域的干旱时空特征,研究干旱的时空演变规律并揭示其对农业生产的影响。结果表明:(1)基于SPEI得到的干旱频次与受灾、成灾面积的相关性通过了0.1的显著性水平检验,表明SPEI在淮河流域具有较好的适用性;(2)淮河流域干旱发生时间差异明显,干旱次数呈现波动变化,发生重旱和特旱次数占总干旱的比重是20.0%,其中重旱和特旱在1960s比重最大(24.8%),其次是2010s(15.8%),在1980s比重最低(10.0%);(3)干旱的空间分布差异大,淮河流域干旱频率在27.76%—36.04%之间,西北部和东南部发生干旱强度较西南部、东北部及中部低;(4)淮河流域总体呈干旱化的趋势,从中部到四周呈现由高到低递减的趋势变化,且空间模态表现为全区一致型、南北相反型和东西相反型。