Antitumor activity of siwenmycin: a novel anthracycline antibiotic

A novel anthracycline antibiotic, siwenmycin, isolated from the culture of Streptomyces galilaeus var. siwenesis, was examined for its antitumor activities against P388, K562, B16-F10, HeLa, HEp-2 and Lewis lung carcinoma cell lines. The results showed that siwenmycin was effective against P388, K562, HeLa and HEp-2 tumor cell lines in vitro, and significantly inhibited the growth of the Lewis lung carcinoma cell line in vivo. Siwenmycin could also suppress spontaneous and artificial pulmonary metastases of B16-F10 and Lewis lung carcinoma cell lines in C57BL/6 mice. The inhibitory effect of siwenmycin on spontaneous pulmonary metastasis of Lewis lung carcinoma in C57BL/6 mice was even stronger than that of adriamycin (ADM), which is, at present, commonly used in clinical practice. Furthermore, the double-labeling test used in this study has verified that siwenmycin can inhibit cellular RNA synthesis at about one tenth the concentration required to inhibit DNA synthesis to the same degree, indicating that the antitumor mechanism of siwenmycin also differs from that of ADM. The acute toxicity of siwenmycin was very low, and it was as effective in vivo as in vitro, suggesting that this newly found antibiotic should be studied for possible clinical antitumor applications.

[Improvement of memory in mice by extracts from leaves of Ginkgo biloba L]

The study has shown that the extracts from leaves of Ginkgo biloba can significantly improve the NaNO2 and scopolamine induced impaired memory in mice. The potency of the ethanolic extract is greater than that of the aqueous extract. The ethanolic extract acts favorably on the memory function of normal animals. Both extracts help to prolong the survival time of mice receiving 200 mg/kg(ip)NaNO2.

Hepatic artery ligation and infusion chemotherapy for unresectable primary liver cancer

During the period of 1958-1989, 356 patients with pathologically proven primary liver cancer (PLC) were determined by laparotomy to be unresectable. Of the 356 patients, 51 (14.3%) were of subclinical stage, 287 (80.6%) of moderate stage and 18 (5.1%) of late stage. The association of liver cirrhosis was present in 310 patients (87.1%). Treatment modalities in 356 patients were divided into 4 groups: hepatic artery ligation (HAL) (51), hepatic artery infusion (HAI) of chemotherapeutic agents (114), HAL + HAI (117), and HAL + HAI + radiotherapy (74). The 5-year survival rate was zero in the 4 groups in the period of 1958-1977. During 1978-1989, however, the 5-year survival rate was zero in HAL, 7.9% in HAI, 24.4% in HAL + HAI (with second look resection in 10 patients), and 36.5% in HAL + HAI + radiotherapy (with second look resection in 19). The marked improvement in survival in later period was attributable to the accurate site of hepatic artery catheter, longer infusion chemotherapy, and combination treatment, particularly second look resection in some of the patients. These results indicate that HAL + HAI + combination treatment might provide a possible prolongation of survival or even resection in some patients with original unresectable PLC.

[Change of T lymphocyte subsets in peripherial blood of children with malnutrition and zinc deficiency]

Sixty children with malnutrition were investigated in this study. The results showed a reduction of serum zinc in moderate and severe cases compared with the mild and normal groups. OKT3+, OKT4+ and OKT8+ cells in peripheral blood of mild malnutrition were significantly decreased in contrast to normal control. The reductive degree of OKT8+ and OKT4+ cells correlated with the severity of malnutrition. OKT8+, OKT4+ and OKT4+/OKT8+ ratio of moderate and severe malnutrition with infection were much lower than those without infection. Our findings suggested that main effective and regulative cells of cell-mediated immunity were impaired. OKT3+ and OKT4+ cells might be used as a sensitive index for early assessment of the immune function in malnutrition children.

Heat Conductivity of Amorphous Solids: Simulation Results on Model Structures

Through numerical simulation and consideration of phonon scattering by two-level states, the heat conductivity kappa(T), where T is temperature, has been calculated on model structures. The values obtained are in good quantitative agreement with measured data on polymethylmethacrylate, epoxy, amorphous selenium, and amorphous silicon dioxide over the temperature range 0.1 to 100 K. The calculated results reproduce the plateau feature, in the range of 5 to 20 K, that is generic to the heat conductivity of amorphous solids. Two model parameters, one characterizing the degree of structural disorder and the other related to the relaxational absorption of two-level states, are identified as being responsible for the behavior of kappa(T) at T >/= 5 K. The simulation results indicate the existence of a frequency-independent phonon diffusion regime that is consistent with the minimum phonon mean-free-path hypothesis. The magnitude of the phonon diffusion constant in this regime is shown to give a reasonable quantitative account of high-temperature kappa(T) in amorphous systems.

Importance of viability and attachment to an ascites tumor in the release of plasminogen activator

Tumor plasminogen activator (PA) has been alleged to play a role in the growth and metastasis of tumors. Before such a role can be realized, PA first must be released from tumor cells. Having determined intra- and extracellular PA and PA-inhibitor activities in an experimental pancreatic ascites tumor grown in hamsters, the release of PA from these cells was investigated. No PA activity was detected in the suspension medium of freshly isolated tumor cells; inclusion of plasminogen, fibrinogen, or collagen in the medium yielded similar negative results. On the other hand, PA activity was demonstrated to be released in a time-dependent manner from these tumor cells embedded in fibrin clots. Plasminogen activator activity also was not found in the suspension medium of frozen-thawed tumor cells, despite the fact that most of them had breaks on their cell membrane. Unlike freshly isolated tumor cells, PA was not released from frozen-thawed cells embedded in fibrin clots. Full PA activity was demonstrated in frozen-thawed cells treated with Triton X-100, however. Frozen-thawed cells exhibited signs of severe damage, and more than 80% of them failed to exclude trypan blue. Obviously PA is released from viable tumor cells embedded in fibrin clots but not suspended in artificial medium. The PA-release mechanism, not PA itself, is destroyed in cells rendered nonviable by freeze thawing.

Determination of oxyfluorfen herbicide and oxyfluorfen amine residues in garbanzo beans by liquid chromatography

Oxyfluorfen and oxyfluorfen amine were determined by liquid chromatography (LC) with ultraviolet (UV) and photoconductivity detection (PCD). A simple extraction procedure acceptably recovered both analytes from garbanzo beans over a wide range of fortifications (0.05 to 20 ppm) (83 +/- 4 for oxyfluorfen; 85 +/- 4 for oxyfluorfen amine). Percent recoveries decreased slightly as the fortification level decreased. Both analytes could be determined simultaneously at a concentration greater than 0.2 ppm in garbanzo beans. Detection limits were 3 ng for oxyfluorfen and 100 ng for oxyfluorfen amine using LC/UV, and 12 ng for both oxyfluorfen and oxyfluorfen amine with LC/PCD. Different knitted reaction coils and photoreactors were evaluated. Photoproduct yields and identification were determined by ion chromatography. The LC/PCD method measures oxyfluorfen and oxyfluorfen amine separately and has a shorter analysis time, while the standard method using gas chromatography measures total residues and is more sensitive.

Preliminary result of mixed bacterial vaccine as adjuvant treatment of hepatocellular carcinoma

Mixed bacterial vaccine (MBV) was employed in the multi-modality treatment of hepatocellular carcinoma (HCC) during 1985-1988. Thirty eight patients undergoing palliative resection and cisplatin therapy (Series 1) and 48 patients with unresectable HCC who received hepatic artery ligation + intraarterial cisplatin infusion + radiotherapy (Series 2) were randomized to receive MBV or not. In series 1, the 1- and 2-year survival rates of MBV group and control were 75% vs 58% (P = 0.19) and 45% vs 39% (P = 0.23). In series 2, the 1-, 2- and 3-year survival rates were 59%, 41% and 41% for MBV group and 39%, 25% and 20% for the control, respectively (P1 = 0.07, P2 = 0.09, P3 = 0.07). In addition, MBV improved the "second look" resection rate to 40% as compared to 17% in the control (P greater than 0.05). MBV could also prevent such immunosuppression as decrease of macrophage activity caused by radiotherapy. We consider MBV a potential nonspecific immunostimulant in the multimodality treatment of HCC.

Determination of nabam fungicide in crops by liquid chromatography with postcolumn reaction detection

The ethylenebisdithiocarbamate (EBDC) fungicide, nabam, was determined in several crop matrixes using liquid chromatography with postcolumn reaction detection. After separation by micellar liquid chromatography, nabam (EBDC sodium salt) was acid hydrolyzed to ethylenediamine and fluorigenically labeled with o-phthalaldehyde-mercaptoethanol (OPA-MERC). Standard curves were linear from the detection limit of ca 1 ng to 1000 ng. Nabam was recovered in high yield (89 plus or minus 7.7%) over a range of concentrations (0.1 to 20 ppm) from fortified samples of papaya, lettuce, cucumber, spinach, and applesauce using a simple extraction method. Efforts to convert the more popular EBDC fungicides, maneb and mancozeb, to nabam are discussed.

Effects of taurine and ketamine on bovine retinal membrane lipid peroxidation

Lipid peroxidation disrupts membrane integrity and causes structural and functional alterations in ischemic tissues. Taurine and ketamine are putative ischemic protectants that affect Ca2+ influx. Here we report the influence of these compounds on lipid peroxidation in subcellular fractions, isolated cells and intact tissue from bovine retinas. P2 membrane fractions and isolated cells were exposed to the lipid peroxidation inducers cadmium chloride (200 microM) or L-ascorbic acid (1 mM) in the presence of 0-50 mM taurine, 0-10 mM ketamine, 1 mM kynurenic acid or 1 mM dextromethorphan. The latter compounds are N-methyl-D-aspartate receptor antagonists. Lipid peroxidation in isolated eyes reperfused after 1 h of ischemia either with or without protectants was determined by thiobarbituric acid assay. Glutathione was measured in isolated retinas subjected in vitro to simulated ischemia (no glucose or oxygenation) for 60 min either alone or in the presence of taurine or ketamine. Ketamine inhibited chemical- or ischemia-induced lipid peroxidation as well as ischemic glutathione depletion. Under the same conditions, taurine failed to affect lipid peroxidation or glutathione. The data show a direct effect of ketamine on lipid peroxidation and point to separate mechanisms of action for ketamine and taurine.

Infrared optics of structured metal-insulator particulates

We show that rodlike particulates structured from interleaving layers of metal and insulator (or semiconductor) can exhibit novel infrared and far infrared characteristics that are tunable through the control of their geometric parameters. Results of scattering and absorption calculations are presented which demonstrate the validity of approximating the dielectric constant of the layered material by its effective medium value, thereby simplifying the prediction of the infrared properties. By clarifying the origin of the infrared absorption peaks, it is shown that the positions of the peaks are dependent on the transverse dimension of the particles as well as on the insulator dielectric constant and its relative fraction. The infrared characteristics of the structured particulates are contrasted with those of the metal, the insulator, and the semiconductor.

Myosin heavy chain composition of single fibres from m. biceps brachii of male body builders

The myosin heavy chain (MHC) composition of single fibres from m. biceps brachii of young sedentary men (28 +/- 0.4 years, mean +/- SE, n = 4) and male body builders (25 +/- 2.0 years, n = 4) was analysed with a sensitive one-dimensional electrophoretic technique. Compared with sedentary men, the body builders had a higher proportion of fibres containing only MHC type IIa (36 +/- 4 vs 12 +/- 2%; P less than 0.05), but a lower proportion of fibres with a coexistence of MHC types IIa and IIb (16 +/- 3 vs 34 +/- 2%; P less than 0.05) and nearly no fibres containing only MHC type IIb (1 +/- 1 vs 12 +/- 1%; P less than 0.05). Myofibrillar ATPase histochemistry only demonstrated a trend towards a higher proportion of type IIa fibres (31 +/- 6 vs 25 +/- 6%) and a lower proportion of type IIb fibres (18 +/- 5 vs 26 +/- 6%) within the body builders. These results, therefore, suggest an altered expression of MHC isoforms within histochemical type II fibres of human skeletal muscle with body building. Furthermore, in human skeletal muscle differences in expression of MHC isoforms may not always be reflected in the traditional histochemical classification of types I, IIa, IIb and IIc fibres.

Ageing alters the myosin heavy chain composition of single fibres from human skeletal muscle

The myosin heavy chain composition of single fibres (n = 1088) was analysed with an electrophoretic technique in biopsy material from m. vastus lateralis (n = 5) and m. biceps brachii (n = 4) of young (23-31 years old) and elderly men (68-70 years old). In m. vastus lateralis, elderly subjects had a higher proportion of fibres showing a coexistence of myosin heavy chain types I and IIa (20 +/- 3% vs 8 +/- 1%, P less than 0.05) and of myosin heavy chain types IIa and IIb (33 +/- 2% vs 12 +/- 4%, P less than 0.05). In contrast, the young subjects had a higher proportion of fibres containing only myosin heavy chain type I (50 +/- 5% vs 33 +/- %, P less than 0.05) and type IIa (26 +/- 3% vs 12 +/- 2%, P less than 0.05). A similar pattern of myosin heavy chain expression was found in single fibres from m. biceps brachii, with the exception that the elderly subjects had a lower proportion of fibres with coexistence of types IIa and IIb (23 +/- 1% vs 34 +/- 2%, P less than 0.05) and a higher proportion of fibres containing only myosin heavy chain type IIa (25 +/- 5% vs 12 +/- 2%, P less than 0.05). Three fibres from m. biceps brachii contained all three isoforms. These results indicate that coexistence of myosin heavy chain isoforms in single fibres is present in skeletal muscles of young adults, and that there is an increased occurrence of this phenomenon with ageing.(ABSTRACT TRUNCATED AT 250 WORDS)

Factor I reference typing report

Complement factor I (IF) reference typing has been examined using polyacrylamide gel isoelectric focusing followed by electroblotting with enzyme immunoassay. The submitted samples could be classified into three common and two new variants, and these were controlled by two common and two rare alleles. Two common alleles were IF*B (the most common allele) and IF*A, and two new rare alleles were designated IF*A1 and IF*B1, respectively.

Factor H polymorphism, typing by isoelectrofocusing and immunoblotting: no association with rheumatoid arthritis

The genetic polymorphism of human factor H (beta 1H) was investigated by a combination of isoelectrofocusing and immunoblotting. This simple method is reliable and economical. The allelic frequencies in the Newfoundland population were estimated to be 0.597 and 0.403 for FH*1 and FH*2, respectively (129 individuals typed). No association of factor H types with rheumatoid arthritis was found (111 patients typed).

Micro-scission of YAC tumor cells during antibody-dependent cellular cytotoxicity mediated by human neutrophils

The cellular events accompanying neutrophil-mediated antibody-dependent cellular cytotoxicity (ADCC) directed against YAC erythroleukemic target cells have been studied by time-lapse fluorescence-intensified microscopy. The YAC plasma membrane and cytosol were labeled with the fluorescent probes diC18Icc and eosin Y, respectively. Fluorescently labeled and IgG-opsonized YAC cells were incubated at 37 degrees C while observed by optical microscopy. During temporal studies of neutrophil-YAC conjugates, the cytosol of YAC cells accumulated in tubular and spherical compartments of the neutrophils' vacuolar apparatuses. To distinguish between several possible mechanisms of target cytosol uptake, diC18Icc-labeled YAC cells were observed during identical conditions. The membrane label diC18Icc was found to accumulate within neutrophils in an identical fashion. At roughly 30 min, 25 and 38% of neutrophils in apparent conjugates had internalized tumor cell cytosol or plasma membrane, respectively, within a vesicular compartment. The IgG-dependent uptake of eosin Y and diC18Icc by neutrophils was diminished by exposure to 2.5 mM sodium azide. When cells were exposed to 5.5 mM sodium azide, 1 mM iodoacetamide, or 4 degrees C, conjugate formation and uptake of eosin Y or diC18Icc were abolished. An artifactual accumulation of eosin Y or diC18Icc in neutrophils was further ruled out by control studies. Non-specific exchanges of eosin Y and diC18Icc labels of YAC cells with tannic acid-treated red blood cells (RBCs) and normal neutrophils were studied. Since hemoglobin binds tightly to eosin Y, RBCs can easily detect eosin Y leakage. No exchange of eosin Y or diC18Icc from YAC cells into bound tannic acid-treated erythrocytes was found.(ABSTRACT TRUNCATED AT 250 WORDS)

A new polymorphic variant of human complement factor I

Sera from 305 individuals were typed for factor I, and a new variant, tentatively designated FI C, was found. All other samples were FI B except for seven samples from Chinese that were of the FI AB phenotype. This suggests that polymorphism of factor I may be rare in Caucasians.

Dual role of fibronectin in hematopoietic differentiation

The adhesive glycoprotein fibronectin provides anchorage for fibroblasts and hematopoietic progenitor cells in vitro. Fibronectin also demonstrates growth factor activity for fibroblasts; however, there is no available information regarding its role as a hematopoietic growth factor. To distinguish growth factor activity of fibronectin from its anchorage activity for hematopoietic progenitors, we assessed the ability of purified human plasma fibronectin to promote human bone marrow erythroid, granulocyte-macrophage (GM) and mixed granulocyte-erythroid-macrophage-megakaryocyte (GEMM) colony formation in liquid suspension, methylcellulose, and fibrin clots under serum-free conditions. Addition of fibronectin to methylcellulose cultures, or to cultures formed in fibrin clots, using fibrinogen depleted of fibronectin by preadsorption over gelatin-Sepharose and clotted with thrombin, resulted in up to a twofold enhancement of proliferation of erythroid burst-forming units (BFU-E), erythroid colony-forming units (CFU-E), and CFU-GEMM. This effect was concentration-dependent up to a fibronectin supplement of 100 micrograms/mL. By contrast, CFU-GM proliferation was not affected by the addition of fibronectin to the cultures. Fibronectin-adherent marrow cells overlaid with liquid medium formed both early and late-appearing erythroid colonies, whereas similarly cultured plastic-adherent marrow cells did not. Erythroid colony formation was observed in cultures of fibronectin-adherent marrow cells overlaid with methylcellulose but not in cultures of plastic-adherent marrow cells under the same conditions. Finally, the erythroid growth-promoting activity of fibronectin was inhibited by arginyl-glycyl-aspartyl-serine (RGDS), a tetrapeptide that competitively blocks the interaction of fibronectin with its receptor. We conclude that fibronectin plays a dual role in hematopoiesis: providing (a) anchorage for erythroid and primitive progenitors, and (b) as a proliferative stimulus for these hematopoietic cells. Both activities may be mediated by the cell adhesion domain of the molecule.