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Background/Aim: Over 190 million people in the world suffer from diabetes mellitus. Diabetics are 25 times more likely to have a leg amputated because of unhealing foot ulcers. Herbal medicine has been used in China to salvage the ulcerated limb. With the aim to study the efficacy of two commonly used herbs for ulcer healing, namely Radix Astragali and Radix Rehmanniae, a good animal model needs to be developed for a proper in vivo investigation. Methods: Firstly, a diabetic animal model was established by streptozotocin injection. Then standard wounds were created on the feet of the diabetic rats. Digital photographs were taken and analyzed by a novel image analysis software. Results: The average ulcer area in the Radix Rehmanniae treatment group was 11.45 mm2, which was significantly smaller than the 15.12 mm2 in the water treatment group (p = 0.04). Radix Astragali, on the other hand, was found to have no significant effect on ulcer shrinkage. Conclusion: Further investigation is needed for the identification of the active principles of Radix Rehmanniae.

Purpose. The purpose of this study is to identify the relationship between the academic scores of school subjects and the performance in national qualified examination for registered professional nurses (NQEX-RPN). Methods. One hundred and seventy-seven graduates of the two-year Associate Degree in Nursing at one of the junior college of nursing in Taipei, Taiwan were included in this study. Information of student academic records and NQEX-RPN results were reviewed. The data were entered into the statistical software (JMP-IN 3.2.1, SAS Institute Inc.) for analysis. Results. (1) In total, 34 subjects (16 nursing subjects and 18 non-nursing subjects) were included in this two-year nursing curriculum. Nine nursing subjects were statistical significant and were positively related with the performance in NQEX-RPN. (2) Year 1 grade point average (GPA) of nursing subjects was significantly correlated with the performance in NQEX-RPN but not Year 2 GPA. (3) The performance of two subjects in NQEX-RPN, namely Fundamental Nursing and Psychiatric–Community Nursing, were not significantly correlated with their related school subjects. Conclusion. The academic scores in only half of the nursing subjects were found to be weakly associated with the performance in NQEX-RPN, although the association was statistically significant. Also, performance in NQEX-RPN was not associated with the final year GPA. Thus, the nursing curriculum and teaching contents may need to be redesigned in order to match with NQEX-RPN.

K24 capsular polysaccharide (K24-CPS), with a known structure of a repeating unit, was isolated from the capsule of Klebsiella pneumoniae serotype K24. The polysaccharide was found to suppress the proliferation of Ehrlich ascites tumour (EAT) cells in vitro, but did not alter the cell cycle distribution of cells. K24-CPS treatment reduced the tyrosine phosphorylation of some proteins in EAT cells. Furthermore, the treatment also decreased the expression of c-JUN, but had no effect on the levels of c-FOS and c-MYC. It is speculated that the growth suppression effect of K24-CPS may be related to its effect in down-regulating c-JUN expression.

To provide a secure traversal service, firewalls need more than static packet filtering and application-level proxies. SOCKS (Secure sOCKets) is an application-independent transport-level proxy that offers user-level authentification and data encryption. An extended SOCKS UDP (user datagram protocol) binding model with appropriate socket calls is proposed to provide complete support for UDP-based multimedia streaming applications.

Alkaline-soluble antitumor polysaccharide was prepared from the cell wall of the mushroom Flammulina velutipes. The backbones) of the polysaccharide is mainly composed of beta-(1-->3)-D-linked glucose and its molecular weight was estimated to be about 200 kD. The polysaccharide was found to be non-toxic by brine shrimp assay. When injected into mice intraperitoneally, the polysaccharide triggered proliferation of splenic lymphocytes and also vascular dilation and hemorrhage (VDH) response. The polysaccharide exhibited potent anti-tumor activity against sarcoma SC-180 in vivo but not in vitro.

Methotrexate (MTX) suppressed the growth of Ehrlich ascites tumor (EAT) cells in vitro. The intracellular level of phosphoribosyl 5-pyrophosphate (PRPP) of EAT cells increased in a dose-dependent manner in response to MTX treatment. At the same time, the rate of glucose transport was lowered. Hypoxanthine reversed both these effects of MTX and partially rescued EAT cell growth. Under all conditions tested, changes in rate of glucose transport were shown to be the result of alterations in the number of glucose transporter (Vmax) rather than ligand affinity (Km). The dual action of MTX as a chemotherapeutic agent is discussed in this light.

Oxidative modification of human low density lipoprotein (LDL) has been implicated in plaque formation in blood vessels leading to atherogenesis. Conversely, there is increasing evidence that prevention of LDL oxidation reduces the incidence of coronary artery disease. Here, we have compared the effect of unconjugated bilirubin (Bu) and Trolox (a vitamin E analogue) on the oxidation of LDL after treatment with Cu2+ under defined conditions. We observed that Bu, at or near the normal serum level (i.e. 17 microM) effectively inhibits oxidation of LDL, while it takes at least 500 microM Trolox to achieve a similar effect. This means that, on a per mole basis, Bu is > 20 times more effective than Trolox in preventing LDL oxidation. The oxidation of LDL was assessed by agarose gel electrophoresis. This was further corroborated by assaying the malondialdehyde formed upon reacting the presumptive peroxidation product(s) of LDL with thiobarbituric acid. Thus, we have directly verified that Bu and, less so, Trolox, can each prevent the oxidative damage of LDL in vitro. Our result supports the contention that Bu as an endogenous antioxidant can prevent LDL oxidation and hence reduce the risk of atherogenesis.

Purpurogallin, a flavinol obtainable from oak nutgalls prevented lysis of human erythrocytes exposed to an azo-initiator of peroxyl radicals [2,2'-azo-bis (2-amidinopropane) dihydrochloride] at 37°C. The percentage of this inhibition of erythrocyte lysis varied with the concentration of purpurogallin. In this system, the effect of purpurogallin surpassed those of lactosylphenyl-trolox, trolox and ascorbate, while mannitol, superoxide dismutase and/or catalase were without effect. While other concurrent mechanisms may be involved in purporogallin action, it would appear that the amphipathic (both hydrophilic and lipophilic) nature of this flavinol and of trolox and lactosylphenyl-trolox, is an important factor. In fact, these three antioxidants, with purpurogallin as the best red cell protector here, excelled the protective effects of the other more hydrophilic antioxidants.

Lithospermic acid B has been isolated to > 95% purity by high performance liquid chromatography from the aqueous extract of the roots of Salvia miltiorrhiza . When infused at 5.5 μmoles/kg into the post-ischemic rabbit heart, it reduced by 62 ± 10% (n = 8) the myocardial damage found in the saline control in a rabbit ischemia-reperfusion model.

Esophageal cancer (EC) is the sixthmost common cause of cancer-related deaths worldwide. Surgery is the main treatment option for EC, however, postoperative recurrence rate is high due to cancer metastasis. Even though surgery followed by adjuvant chemotherapy and concurrent radiation have shown favorable efficacies, searching for alternative adjuvant treatments—such as Chinese herbal medicines—for metastatic EC also get patients’ desire. Based on our previous screening among various Chinese herbs, Andrographis paniculata (AP) exhibited anti-tumor effect in human esophageal cancer cells. The present study therefore aimed to evaluate the anti-tumor and anti-metastasis activities of AP and the combined effects of such herbal extract with standard chemotherapeutics for EC, cisplatin and 5-fluorouracil (5-FU). Human squamous esophageal cancer (EC-109) xenograft-bearing mice model was employed to evaluate the in vivo antitumor activities. The absorption of AP water extract was determined in human intestinal Caco-2 cell monolayers. The absorbed AP components have been evaluated for their cytotoxicity using MTT assay. Our preliminary results of in vivo study showed that the number of tumor nodules was decreased in intraperitoneal xenograft-bearing mice treated with AP water extract (1600 mg/kg daily for 20 days). Besides, AP treatment also enhanced the inhibitory effects of cisplatin plus 5-FU on the number of tumor nodules. In view of our in vitro results, the absorbed AP components (APPC) showed significant cytotoxicity on EC-109. Furthermore, seven known chemical constituents were identified in the APPC for the first time, suggesting these absorbed AP components may be responsible for the activities. In conclusion, the AP water extract is effective on inhibiting tumor growth in vivo and the chemical constituents in the absorbed AP components were identified, which may further enhance the understanding of the therapeutic mechanisms of this herb. The anti-metastasis effects of AP will also be further investigated. ACKNOWLEDGEMENT: This work was supported by Food and Health Bureau HKSAR, Health and Medical Research Fund no. 11120981.

Three purified polysaccharide fractions designated as PAC-I, PAC-II, and PAC-III were prepared from Aloe vera L. var. chinensis (Haw.) Berg. by membrane fractionation and gel filtration HPLC. The polysaccharide fractions had molecular weights of 10,000 kDa, 1300 kDa, and 470 kDa, respectively. The major sugar residue in the polysaccharide fractions is mannose, which was found to be 91.5% in PAC-I, 87.9% in PAC-II, and 53.7% in PAC-III. The protein contents in the polysaccharide fractions was undetectable. NMR study of PAC-I and PAC-II demonstrated the polysaccharides shared the same structure. The main skeletons of PAC-I and PAC-II are beta-(1--4)-D linked mannose with acetylation at C-6 of manopyranosyl. The polysaccharide fractions stimulated peritoneal macrophages, splenic T and B cell proliferation, and activated these cells to secrete TNF-alpha, IL-1 beta, INF-gamma, IL-2, and IL-6. The polysaccharides were nontoxic and exhibited potent indirect antitumor response in murine model. PAC-I, which had the highest mannose content and molecular weight, was found to be the most potent biological response modifier of the three fractions. Our results suggested that the potency of aloe polysaccharide fraction increases as mannose content and molecular weight of the polysaccharide fraction increase.

Firewall support for UDP traffic today is still insecure and inadequate. We propose in this paper a transport layer proxy (TLP) to provide a secure UDP firewall traversal service on the transport layer (the TLP supports TCP as well). For each UDP association with endpoints separated by a TLP server, the TLP server performs user-level or host-level authentication, packet filtering, packet relaying, optional network address translation, session logging, timing-out of idle association, and other security-related functions. The core of the TLP is a two-step TLP binding procedure that makes a UDP association stateful between a TLP client and a TLP server. This binding procedure supports Active UDP Open, Passive UDP Open, and Source-Specific UDP Open, which a local program may perform on a UDP socket.

We have previously shown that K1 capsular polysaccharide antigen (K1CPS) of Klebsiella exhibits anti-tumor activities. In the present study, we examined the effect of K1CPS on cytotoxic effector cells. We found that K1CPS could activate many cytotoxic effector cells including alloreactive cytotoxic T cells and tumor-infiltrating lymphocytes (TILs). Moreover, K1CPS could increase the anti-tumor activity of lymphokine-activated killer (LAK) cells, both in vitro and in vivo. The i.p. injection of K1CPS in low dose could enhance the LAK cytotoxicity and the effect was further potentiated by coculture of LAK cells with K1CPS and low concentration of murine rIL-2 in vitro. The phenotypic characterization revealed that K1CPS might contribute to the increase in CD3+ LAK cell subpopulation by its in vivo priming effect. In addition, the K1CPS-treated LAK cells were able to inhibit the growth of WEHI-164 tumor cells in vivo in Winn-type inhibition assay. Subcutaneous (s.c.) and intraperitoneal (i.p.) adoptive infusion of LAK cells (splenocytes from K1CPS-treated WEHI-164-bearing mice cultured with K1CPS-plus-rIL-2) into WEHI-164 sarcoma-bearing mice could slightly cause regression in terms of tumor diameter, and more significantly in sarcoma weight.

Fluorescence microscopic imaging (FMI) is one of the fastest growing and most powerful techniques to study cellular activities in a living single cell. FMI has been widely used to monitor the temporal and spatial changes of many important intracellular messengers such as Ca2+, H+ and cAMP. In the course of our study of cellular responses with confocal scanning fluorescence microscopy, we detected two sources of artifacts which may render experimental observations invalid. First, the water content of the DMSO used could affect the efficiency of loading of the fluorescence indicator into cells and also give rise to spurious fluorescence spots. Secondly, apparently spontaneous temperature-dependent oscillations of BCECF fluorescence and cellular pulsations were recorded in cells which might be misinterpreted as natural rhythmic behavior. These were later shown to be artifacts arising from changes in refractive indices of the immersion oil due to small fluctuations in temperature, which in turn leads to random shifts of the focal plane erroneously manifest as signal oscillations. Based on these observations, certain recommendations for the control and elimination of false images are presented.

The levels of bone-specific alkaline phosphatase (BALP) in plasma and tumour tissue samples of 20 Chinese patients with osteosarcoma in Hong Kong were measured by the wheat germ lectin precipitation technique. The plasma BALP levels in these patients were significantly higher than those of the normal subjects (p < 0.001), and also significantly higher than those of patients with benign bone tumor and those of patients with malignant tumor metastasized to the bone (p < 0.0001). Considering the prognostic value of BALP for osteosarcoma, the plasma BALP levels at the time of diagnosis were found to be significantly related to the rate of disease recurrence (p < 0.05). Furthermore, at the time of relapse, the plasma BALP levels in the group of recurrent osteosarcoma patients were significantly higher than those of osteosarcoma patients showing no recurrence (p < 0.05). When ALP was assayed in the tumor tissue, the BALP levels were also significantly higher than those of the control cortical bone extracts in the same group of patients (p < 0.05). We conclude that plasma BALP is a sensitive and specific biochemical parameter in the diagnosis and the subsequent monitoring of osteosarcoma.

The effect of hyperthermia at 43 degrees C on intracellular pH (pHi) in human U-87 MG glioblastoma cells was studied by using the fluorescent probe 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein-pentaacetoxymethyl ester. The presence of Na+/H+ antiporter activity in the cells were demonstrated by the Na(+)-dependent increase in intracellular pH (pHi) after cellular acidification in the absence of HCO3-. Hyperthermia at 43 degrees C caused significant decrease in pHi. The acidification was readily reversible by cooling the cells back down to 37 degrees C. The pHi change was inhibited by the addition of 1 mM amiloride in the incubation medium. Amiloride and hyperthermia exhibited a synergistic effect in suppressing thymidine incorporation into the cells.

Multiple hyperthermia was found to exert an additive antitumor effect when combined with the in vivo production of tumor necrosis factor alpha (TNF-alpha) in mice bearing Ehrlich ascites tumor (EAT). TNF-alpha was produced in EAT-bearing mice by priming the animals with zymosan and subsequently challenging with lipopolysaccharide (LPS). Mice were pretreated with sulindac and D-mannoheptulose to alleviate the toxic side effects of LPS. While the ability of these tumor-bearing mice to produce TNF-alpha remained unchanged under hyperthermia, the EAT cell number was suppressed in the combined-treatment group compared with groups treated with TNF-alpha or hyperthermia alone. In the same comparison, the life span of EAT-bearing mice in the combined-treatment group was prolonged.

Radix bupleuri , the root of Bupleuri spp., Chinese medicinal herbs used for the treatment of influenza, malaria and menstrual disorders, were extracted with hot water and separated into five different fractions (RB, RBI, RBII, RBIII and RBIV) by stepwise alcohol precipitation. One of these fractions, RBI, was then fractionated into RBIa and RBIb by gel filtration using G-100 Sephadex. These two fractions were further purified into RBIai, RBIaii and RBIbi, RBIbii fractions respectively by ion-exchange chromatography using DEAE-Sephadex. Each of these fractions is a heteropolymer consisting mainly of carbohydrate and varying proportions of protein and uronic acid. RBIaii was found to show strong anti-tumor activities in sarcoma-bearing mice. Mechanistic studies showed that RBIaii exhibited a potent activating effect on the cytotoxic activity of macrophages, NK and LAK cells against tumor cells. In addition, RBIaii could increase the number of tumor infiltrating lymphocytes (TILs) in the tumor site of WEHI-164-bearing mice. Furthermore, RBIaii could induce the release of interferon-γ by lymphocytes in vitro.

Recently, there has been renewed interest in propyl gallate, a preservative in foods and fuels. This compound, which exhibits antimicrobial activity, has been found to be toxicologically safe after almost 30 years of evaluation. In the present study, we examined whether propyl gallate is a hepatoprotective antioxidant, and investigated some of its bases of action vis-a-vis Trolox, a vitamin E analogue. In isolated rat hepatocytes, propyl gallate prolonged substantially cell survival against oxyradicals generated with xanthine oxidase-hypoxanthine. The protection was dose dependent and excelled that of Trolox, mannitol, or ascorbate, each at or near its optimum level in the same system. In rats undergoing an 80-min partial hepatic ischemia, infusion of propyl gallate at 20 mumol/kg body weight just before a 24-hr reperfusion salvaged the organ by 80.0 +/- 11.5%, an extent comparable to that with Trolox. Mechanistically, we found that propyl gallate (a) protected hepatocytes against the cascade of oxyradicals produced by xanthine oxidase-hypoxanthine; (b) protected hepatocytes against superoxide radicals generated specifically by menadione; (c) protected the functionally important hepatic vascular endothelial cells more effectively than Trolox against xanthine oxidase-hypoxanthine, and (d) approximately halved the amount of lipid conjugated dienes (a more specific marker of oxyradical damage than malondialdehyde) formed in tissues after oxidant damage. Therefore, there are fundamental reasons why propyl gallate is an effective antioxidant-based hepatoprotector, both in vitro and in vivo.

We have previously shown that a mitogenic fraction (PH-I) separated from Pseudostellaria heterophylla exhibits both immunodulatory and anti-tumor activities. In the present study, PH-I was further purified by gel filtration chromatography and the resulting three fractions (PH-I A, PH-I B and PH-I C) were assessed for their anti-tumor activity in vivo. It was found that fraction PH-I C from P. heterophylla could markedly suppress the growth of EAT cells in vivo. Mechanistic studies have shown that i.p. injection of PH-I C into mice could enhance the phagocytic activity thioglycollate-elicited peritoneal macrophages. Moreover, PH-I C showed a potent activating effect on the cytotoxic activity of natural killer (NK) cells and alloreactive cytotoxic T cells (Tc) as well as increased the MurIL-2-induced lymphokine activated killer cell (LAK) activity in vitro. In addition, PH-I C could increase the number of tumor infiltrating lymphocytes (TILs) in the tumor site of WEHI-164-bearing mice. Finally, i.v. injection of PH-I C significantly elevated the levels of IFN-γ and IL-4 in sera of EAT-bearing mice.

Tumor necrosis factor (TNF) could be induced in the serum of ICR mice bearing Ehrlich ascites tumor (EAT) cells by the i.v. administration of antitumor fractions (PH-I A, PH-I B, PH-I C, PH-I Ca, PH-I Cb) separated from the roots of Pseudostellaria heterophylla. TNF could also be detected in the ascitic fluid of EAT-bearing mice 2 h after i.v. injection with PH-I C, PH-I Ca or PH-I Cb. The proliferation of EAT cells was found to be significantly suppressed after the administration of these fractions. Our results suggest that the antitumor activity of P. heterophylla may be related, at least in part, to its capacity to induce TNF production in vivo. The strongest TNF eliciting and antitumor activity was found in the PH-I Cb fraction which is an acidic polysaccharide or proteoglycan with molecular weight of approximately 5000.

We observed that purpurogallin (PPG) which is a flavonoid markedly protects the rabbit against myocardial ischemia-reperfusion injury. In rabbits undergoing 1-h ligation of the anterior ventricular coronary artery, a bolus infusion of PPG was introduced into the post-ischemic heart immediately before 3-h reperfusion. Against negligible necrosis in 6 sham-operated controls, and 41.7 (SD 11.3)% necrosis in the area at risk for the placebo control group (n = 14 animals), the PPG-treated groups (n = 6, 6, 14) had a necrosis of 26.8 (6.4)%, 10.8 (3.5)%, and 11.7 (5.2)% at doses of 2.5, 5, and 10 mumol/kg, respectively (each with p0.01 vs control value). By comparison, infusion of Trolox (a vitamin E analogue) at 5 mumol/kg produced a higher necrosis of 17.7 +/- 7.2% (n = 6, p0.05 vs value obtained from 5 mumol/kg PPG-treated group) in the same model. Note that myocardial necrosis was estimated by tetrazolium-based histochemistry and confirmed by light and transmission electron microscopies. These data support our contention that PPG is an effective cardioprotector, whose mechanism of action will be reported separately.

Sodium tanshinone IIA sulfonate (STS) is a derivative of tanshinone IIA. The latter is a pharmacologically active component isolated from the rhizome of the Chinese herb Salvia miltiorrhiza. Liquid chromatographically pure STS was found to reduce myocardial infarct size by 53.14 +/- 22.79% relative to that in the saline control in a rabbit 1 hr-ischemia and 3 hr-reperfusion model. This effect was comparable to that of Trolox (a better characterized antioxidant serving as a reference cytoprotector), which salvaged the myocardium in the same infarct model by 62.13 +/- 18.91%. Also, like Trolox, STS did not inhibit oxygen uptake by xanthine oxidase (XO), a key enzyme in free radical generation. However, in contrast to Trolox, STS significantly prolonged the survival of cultured human saphenous vein endothelial cells but not human ventricular myocytes in vitro when these cells were separately exposed to XO-generated oxyradicals. Note that the endothelium is recognized to be a key site of oxidant generation and attack. Our findings in vitro and in vivo support the interpretation that STS is a cardioprotective substance, and that it may exert a beneficial effect on the clinically important vascular endothelium.

Separation of mitogenic fraction (PH-I) from Pseudostellaria heterophylla and characterization of its biological activities were investigated. PH-I was isolated as an alcohol-insoluble fraction from the hot water extract obtained by heating the roots of P. heterophylla in water at 80 degrees C for 4 h. It is a water-soluble substance consisting of mainly carbohydrates (56.8%) and a small amount of proteins (7.6%). The incorporation of tritiated thymidine into the DNA of murine spleen lymphocytes could be stimulated by PH-I in a dose-dependent manner. PH-I could act as a priming agent for the release of tumor necrosis factor (TNF) in mice. Moreover, PH-I exhibited potent anti-tumor activities against Ehrlich ascites tumor (EAT) cells in vivo but not in vitro.

We have written a polynomial regression program in BASIC for an IBM-compatible microcomputer. The program is easy to use as it is entirely menu driven

Four hundred thirty-one paired sets of readings of systolic and diastolic blood pressure and 438 paired sets of readings of mean arterial BP from 49 ill newborns, including 21 very low birth weight infants, were analyzed for the extent and pattern of agreement and the linear relationship between the Dinamap oscillometric monitor and the direct intraarterial blood pressure readings. Agreement between the two methods was measured by the intraclass correlation, whereas the linear relationship was assessed by the product-moment correlation.The intraclass correlations for systolic, diastolic and mean blood pressures were 0.696, 0.766, and 0.781, respectively. The product-moment correlations for systolic, diastolic and mean blood pressures were 0.706, 0.768, and 0.786, respectively.BP measurements by the Dinamap monitor showed reasonably close agreement to those obtained by the intraarterial mean arterial pressure ranges above 40 mmHg. For mean arterial pressure of 40 mmHg and lower, BP readings by the Dinamap monitor tended to be higher than those obtained by the intraarterial method. These findings appeared to be consistent regardless of the birth weight of the newborn.

It has been reported that physical exercise may enhance cytochrome P-450 dependent drug metabolism in vivo. In this study we report that the specific activity of aryl hydrocarbon hydroxylase (AHH) in human peripheral lymphocytes (HPL) is enhanced approximately two fold following acute physical exercise. This enhancement of AHH activity in HPL appears to be strongly correlated with enhanced lymphocyte count as well as induced metabolic and exercise stress but not with the intrinsic physical fitness of individuals.

In a case-control study on the risk of traffic accidents among motorcyclists in Singapore, we demonstrated an inverse monotonic relationship between accident risk and driving experience. As compared to drivers with less that 1 yr of driving experience, the odds ratios (adjusted for race, age and frequency of riding) for those with driving experience of 1–4, 5–9 and 10 yr or more were 0.60, 0.50 and 0.36, respectively. We propose that intensive in-circuit training of learner motorcyclists should replace the conventional on-the-road training on the basis that the former serves to increase their driving experience without subjecting the learner motorcyclists to the risk of sustaining road accident.

Contrary to L-lysine, D-lysine showed no inhibitory effect on growth of Ehrlich ascites tumour cell in in vivo studies. The in vitro studies on the growth of cultured Ehrlich ascites tumour cells show

Bacterial lipopolysaccharide (LPS) induces the release of tumour necrosis factor (TNF) into serum of mice previously infected with Listeria monocytogenes or immunized with formalin-killed Corynebacterium parvum. This release is greatly reduced by neutralisation of lipid A of LPS with the antibiotic polymyxin B sulfate. The effect is dose-dependent. Base-hydrolysed LPS, which is devoid of lipid A, cannot induce TNF release. Crude lipid A still retains its ability to induce TNF release but is significantly less effective than native LPS molecules. LPS neutralised by polymyxin B also loses its ability to cause high mortality in C. parvum primed mice. These results suggest that lipid A of LPS molecule is important in causing lethality and TNF release in vivo while the polysaccharide portion may be involved in delivering the lipid A moiety to TNF-producing cells.

The ability of Ehrlich ascites tumor cells to take up glucose increased progressively during the course of tumor development. Simultaneously as the rate of uptake rose, the density of a class of glucose-reversible binding sites for cytochalasin B on the cell surface also increased. In its stereospecificity requirement toward competing sugars and in its sensitivity to phloretin and diethylstilbestrol, this class of binding sites resembled the putative glucose carriers identified in various other cell systems and may represent the glucose transporter in Ehrlich ascites cells. Work with methotrexate (MTX) substantiated this view. Methotrexate arrested tumor growth, inhibited glucose uptake, and reduced the number of cytochalasin B binding sites. In both MTX-treated and untreated cells, the magnitude of changes in number of cytochalasin B binding sites closely paralleled and sufficiently accounted for the magnitude of changes in glucose uptake. Qualitative changes in the turnover and affinity for substrate of the putative glucose carrier need not be invoked.

The in vitro studies on the growth of cultured Ehrlich ascites tumour cells showed similar results as the in vivo studies reported previously. The growth of tumour cells was inhibited when cultured in 0.02 or 0.03 M L-histidine. At these concentrations, L-glycine shows no significant effect.

Egg lecithin at 200 μg/ml or greater was found to abrogate blastogenic responses of human leukocyte cultures stimulated with phytohemagglutinin (PHA), concanavalin A (ConA), purified protein derivatives of tuberculin (PPD), candidin or streptokinase and streptodornase (SKSD) while leukocyte aggregation mediated by PHA, however, occurred irrespective of the presence of the lipid. Inhibition of PHA-mediated responses occurred when the lecithin was added simultaneously with the mitogen but the extent of inhibition decreased with delay in the addition of the lipid. When added 48 h after their exposure to PHA, the presence of lecithin did not change the pattern of [3H]TdR incorporation. Prior sonic treatment of an aqueous suspension of lecithin was found to render the lipid more effective in arresting lymphocyte responses than the unsonicated control. In entity, these results indicated that the lipid did not affect the viability of the leukocyte cultures nor did it seem that the lipid may interfere with the binding of the mitogen per se. It was concluded therefore, that inhibition by lecithin may most likely occur early at a time following binding of the mitogen but before the cells are committed to cellular division and it seems that the plasma membrane might be a likely site of action of the lipid.

Polyriboinosinic-polyribocytidylic acid, statolon and tilorone arrested the growth of Ehrlich ascites tumour cells in vivo. They inhibited cellular glucose uptake and the density of glucose carriers on the cell surface of tumour cells. In both drug-treated and untreated cells, no qualitative change in the turnover and affinity for substrate of the glucose carrier of the tumour cells was observed. The role of interferon inducer on the change of glucose transport of tumour cells is discussed.

Both mice and rabbits injected intravenously with viable Listeria monocytogenes and challenged with bacterial lipopolysaccharide release tumour necrosis factor (TNF) into the blood. Optimal conditions for production of murine TNF using Listeria were established. The cell-kill efficacy of Listeria-TNF and of Corynebacterium parvum-TNF are comparable. Also, the two sera have similar spectra of activity; a wide variety of murine and human tumour cell lines are vulnerable while others are not affected. Among the cell lines tested, Ehrlich ascites tumour (EAT) cell was found to be most susceptible to the cytotoxic effect of TNF. The advantages of using Listeria for producing TNF and using EAT cells in studying the mechanism of action of TNF are discussed.

Incubation of non-excitable murine macrophage cell line PU5-1.8 in K+(140 m M )-Hepes buffer caused membrane depolarization as measured by bis-oxonol and 3,3''-dipropylthio