Role of asialo-GM1 positive liver cells from athymic nude or polyinosinic-polycytidylic acid-treated mice in suppressing colon-derived experimental hepatic metastasis

Liver-derived (LD) murine colon adenocarcinoma MCA-38 cells injected into the ileocolic vein (ICV) of C57BL/6 mice developed distinct hepatic foci within 14-21 days and survived for an average of 19-35 days. In contrast, C57BL/6-nu/nu mice given injections of LD-MCA cells by the same route did not develop hepatic lesions. Furthermore, 111In-labeled LD-MCA-38 tumor cells were rapidly taken up by the liver of conventional mice within 1 h and 73% of the radioactivity remained after 24 h. However, about 60% of the 111In-labeled LD-MCA-38 tumor cells were cleared from the liver of nude mice after 24 h. Nonparenchymal liver cells isolated from untreated conventional mice displayed little cytotoxicity against freshly excised 51Cr-labeled LD-MCA-38 cells but did lyse the standard natural killer target, YAC-1 tumor cells, in 4 h chromium release assays. On the other hand, nonparenchymal liver cells but not spleen cells from nude mice were cytotoxic to 51CR-labeled LD-MCA-38 in vitro. The nonparenchymal liver cell population responsible for tumor killing was phenotypically nonadherent and asialo-GM1 (AsGM1) positive. C57BL/6 mice treated with polyinosinic-polycytidylic acid [poly(IC)] also displayed cytotoxic activity against LD-MCA-38 tumor cells in vitro. Furthermore, poly(IC) treatment of mice 1-8 days after tumor inoculation suppressed the number of hepatic foci and also significantly increased the life span of tumor-bearing mice. Treatment of athymic nude mice or poly(IC)-treated conventional mice with anti-AsGM1 induced significant numbers of foci and significantly decreased the life span of MCA-38-bearing mice suggesting that AsGM1-positive cells in the liver of these mice may inhibit tumor growth in vivo. In conclusion, the host defense system of the liver from athymic nude or poly(IC)-treated mice possess AsGM1-positive cells that can suppress tumor implantation or tumor growth in the early stages of metastasis in liver.

Prospective two-year followup of recombinant interferon-gamma in rheumatoid arthritis

Seventy patients with rheumatoid arthritis (RA) completing a 12-week multicenter double blind trial comparing recombinant human interferon-gamma (r-IFN-gamma) with placebo were enrolled in a longterm prospective protocol evaluating r-IFN-gamma in RA. Forty (57%) patients after 1 year and 26 (37%) patients after 2 years continued the drug with sustained clinical benefit. Over 2 years, r-IFN-gamma was discontinued in 44 patients (lack of efficacy--25, withdrawn consent--7, noncompliant--4, suspected adverse drug reactions--2, concurrent illness--6). Two years of treatment with r-IFN-gamma were well tolerated with sustained clinical benefit in some patients with few significant adverse drug reactions.

Indomethacin modulation of adriamycin-induced effects on multiple cytolytic effector functions

The anticancer agent, Adriamycin (ADM), in addition to being a potent cytotoxic drug has been shown to be an effective immunomodulator. This study was undertaken to determine whether ADM-induced changes in the production of prostaglandins (particularly PGE2) are involved in ADM-associated modifications of selected host defenses. Spleen cells from normal or ADM-treated (5 mg/kg; day -5) C57BL/6 mice were assessed for the following activities: fresh (day 0) and cultured natural killer (NK), cytotoxic T lymphocyte, lymphokine-activated killer (LAK), Fc-dependent phagocytosis and tumoricidal macrophage. All activities were assessed with and without the addition of indomethacin, an inhibitor of the first step of the cyclo-oxygenase pathway of prostaglandin synthesis. Depending on culture conditions, the cytotoxic T lymphocyte and splenic tumoricidal macrophage activities were either unaffected or were augmented by ADM treatment of the spleen donor mice or by addition of indomethacin to the culture, and these effects were apparently independent of one another. In contrast, ADM treatment generally resulted in reduced NK and LAK activities relative to control and elevated Fc-dependent phagocytosis. The addition of indomethacin to the culture effectively reversed these effects. Furthermore, spleen cells from ADM-treated mice were found to produce twice the amount of PGE2 in culture compared to cells from untreated mice. Finally, the direct addition of PGE2 to NK cultures resulted in a dose-dependent inhibition of NK activity and the dose required was comparable to the amount of PGE2 produced by cultured spleen cells from ADM-treated mice. Taken together, these results indicate that at least some of the immunomodulatory effects of ADM are an indirect result of ADM-induced changes in PGE2 production.

Double-blind trial of recombinant gamma-interferon versus placebo in the treatment of rheumatoid arthritis

One hundred five patients were enrolled in a 12-week, randomized, prospective, double-blind, placebo-controlled trial of recombinant human gamma-interferon (rHu gamma-IFN) for the treatment of rheumatoid arthritis. Fifty-four patients received rHu gamma-IFN and 51 received placebo. Forty-two patients in each group completed the 12-week trial. Some clinical improvement occurred in both groups of patients. Although the improvement with rHu gamma-IFN was greater than that with placebo, the differences were generally not statistically significant.

Partial hepatectomy augments the liver's antitumor response

Despite adequate locoregional control, colorectal metastasis to the liver remains a significant cause of death. Resection of hepatic metastasis improves five-year survival 18% to 34%. A study of the impact of 40% partial hepatectomy on cytokine production in the liver was undertaken. Nonparenchymal liver cells (NPCs) were prepared by collagenase perfusion and metrizamide gradient from partially hepatectomized and laparotomized control C57BL/6Ros mice. Nonparenchymal cell from partially hepatectomized mice compared with laparotomized mice showed a twofold to threefold increase in interferon (IFN) activity. Both interferon alpha/beta and supernatants from cultured NPCs of partially hepatectomized mice suppressed the proliferation of liver-derived MCA-38 colon adenocarcinoma cells in vitro. This tumor has been shown to metastasize to the liver of C57BL/6Ros mice. The production of various cytokines by NPCs induced by partial hepatectomy may provide a possible antimetastatic mechanism.

Identification of phenylthiocarbamyl amino acids for compositional analysis by thermospray liquid chromatography/mass spectrometry

The chromatographic separation of amino acids for compositional analysis of peptides and proteins is commonly performed by reverse-phase high-performance liquid chromatography of amino acid residues that have been derivatized with phenylisothiocyanate. The present report describes an extension of this method, which employs thermospray liquid chromatography/mass spectrometry to confirm the identification of the resulting phenylthiocarbamyl (PTC) amino acids. A standard HPLC separation method has been adapted for use with the thermospray technique, and on-column mass spectra of standard synthetic PTC-amino acids have been acquired. These spectra show characteristic fragmentation patterns not seen in the corresponding cyclic phenylthiohydantoin amino acid derivatives. The LC/MS method has been tested on hydrolysates of bovine serum albumin, porcine insulin, and human placental collagen. In each case, the mass spectra of components eluting with the same retention times as the standard PTC-amino acids are similar to those observed in the standard amino acid mixture. Other components display mass spectra that can be interpreted in terms of known in vivo or in vitro modifications to amino acid side chains in these proteins. The LC/MS method has assisted in the identification of by-products of the derivatization reaction. It has also been applied to a study in which an enzyme, citrate synthase, isolated from porcine heart, was compared to the protein expressed by a recombinant porcine citrate synthase gene in Escherichia coli. The data showed that the recombinant protein lacks a modified residue, trimethyllysine, which is present in the enzyme expressed in mammalian tissues.

Modulation of colon-derived experimental hepatic metastasis by murine nonparenchymal liver cells

Although numerous animal tumor models have been used to study colon carcinoma, few display hepatic metastasis. C57B1/6Ros mice inoculated with liver-derived murine colon adenocarcinoma MCA-38 in the ileocolic vein develop distinct hepatic foci within 21 days and survive an average of 35 days. Furthermore, 111In-labeled LD-MCA-38 tumor cells were rapidly taken up by the liver within 60 min and 73% of the label remained in the liver after 24 h. Isolated nonparenchymal liver cells from untreated mice displayed little cytotoxicity against freshly excised 51Cr-labeled MCA-38 cells but did inhibit tumor growth in vitro as measured by inhibition of 3H-thymidine incorporation. Treatment with anti-asialo-GM1 decreased the lifespan of MCA-38 tumor bearing mice suggesting that asialo-GM1 positive cells in the liver may inhibit tumor growth in vivo. Nonparenchymal liver cells from mice treated with polyinosinic-polycytidylic acid showed augmented cytotoxic and cytostatic activity against LD-MCA-38 tumor cells in vitro. Polyinosinic-polycytidylic acid treatment also significantly increased the lifespan of MCA-38 tumor bearing mice. In conclusion, the host defense system of the liver can be modulated to enhance or inhibit colon-derived experimental hepatic metastasis.

Endogeneous interferon alpha/beta produced by murine Kupffer cells augments liver-associated natural killing activity

Nonparenchymal liver cells from untreated C3HeB/FeJ mice, when incubated in medium containing-10% fetal bovine serum or portal serum, produced significant amounts of interferon alpha/beta (IFN alpha/beta). In contrast, other cell populations (spleen, mononuclear blood cells and peritoneal cells) from C3HeB/FeJ mice or nonparenchymal liver cells from other strains of mice (C3H/HeJ, germ-free C3H/HeN and C57Bl/6J) produced little or no detectable IFN in fetal bovine serum under the same culture conditions. The cells in the nonparenchymal liver cell population responsible for IFN alpha/beta production were adherent, phagocytic, silica-sensitive, carbonyl-iron-sensitive, and Thy1.2-, presumably Kupffer cells or resident liver macrophages. IFN alpha/beta production by cultured Kupffer cells was not observed if medium containing fetal bovine serum or portal serum was treated with polymyxin B or if Kupffer cells were cultured in serum-free medium. This suggested that small amounts of endotoxin in fetal bovine or portal serum stimulated Kupffer cells to produce IFN alpha/beta. Possibly, Kupffer cells are in a different state of activation/maturation than peritoneal and splenic macrophages since the sensitivity of resident Kupffer cells from C3HeB/FeJ mice to the stimulatory effects of endotoxin. The endogenous production of IFN alpha/beta by Kupffer cells from C3HeB/FeJ mice can augment liver-associated natural killer (NK) activity against YAC-1 cells (4h) and induce liver-associated cytotoxic activity, not restricted by the major histocompatibility complex, against NK resistant P815 mastocytoma cells (18 h).

Amino acid analysis utilizing phenylisothiocyanate derivatives

Advances in liquid chromatography have brought about the development of new techniques in amino acid analysis which take full advantage of precolumn derivatization procedures. Using phenylisothiocyanate as the reagent, detection limits under 1 pmol can be routinely achieved, allowing the analysis of submicrogram protein samples. Analysis times as short as 10 min for samples after hydrolysis and 1 h for physiologic samples are possible. Accurate, reproducible quantitation of amino acids can be obtained from complex matrices such as plasma, urine, feed, and food samples. This level of performance and flexibility gives the analyst the first realistic alternative to ion-exchange analysis without compromising desirable features of the traditional methodology.

Profile of mood states changes during and after 5 weeks of nightly triazolam administration

This double-blind, placebo-controlled study investigated rebound anxiety during and after 5 weeks of nightly use of triazolam 0.5 mg, a short half-life, rapidly absorbed benzodiazepine hypnotic. The study subjects were chronic insomniacs with moderate levels of psychopathology and prior use of hypnotics. Anxiety was assessed with the Profile of Mood States (POMS), instead of the anxiety scales more typically used in psychopharmacology: the Hamilton Rating Scale for Anxiety and a visual analogue scale. The POMS test was administered twice a day during the study. The results indicated that triazolam was not associated with increased anxiety the morning or the evening after previous-night drug administration. The results are discussed in view of the methodological issues in assessing anxiety in prior studies.

Relationship of radioantibody localization and cell viability in a xenografted human cancer model as measured by whole-body autoradiography

The simultaneous distribution of monoclonal 131I-labeled anti-carcinoembryonic antigen (CEA) immunoglobulin (IgG) (NP-2) or 131I-labeled irrelevant myeloma IgG (Ag8) and [3H]thymidine was studied in hamsters bearing transplants of the GW-39 human colon carcinoma by qualitative double-tracer whole-body autoradiography. Autoradiography showed that large solid GW-39 tumors are characterized by heterogeneity of radioantibody retention and uneven [3H]thymidine accumulation, reflecting zonal variations in antibody reactivity and tumor cell proliferation, respectively. The autoradiographic images showed that both 131I-labeled-monoclonal antibody and control 131I-labeled IgG targeted nonproliferating tumor zones, suggesting a mechanism of nonspecific tumor uptake of radioantibodies in these areas. Absence of tumor center labeling with [3H]thymidine, associated with cellular necrosis, was confirmed by histology and microautoradiography in separate animal studies. In confirmation of earlier reports, 131I-labeled anti-CEA monoclonal antibody gave higher tumor-to-non-tumor labeling patterns than did control 131I-labeled IgG, at both 3 and 7 days following treatment. Immunohistochemical localization of CEA in GW-39 tumors with necrotic centers showed the presence of CEA in nonviable cells, but CEA antigen concentrations were diminished as compared to cells located in the tumor's periphery. The results indicate that double-tracer whole-body autoradiography is well suited for studying the kinetics of radioantibody localization in relation to regional tumor cell viability.

A new, rapid, high-sensitivity analysis of amino acids in food type samples

A new approach to the analysis of free amino acids and amino acids from hydrolyzed foods is described. The method is based on reaction of the free amino acids with phenylisothiocyanate to form stable derivatives which are subsequently separated by liquid chromatography. Sample preparation procedures are described and results are compared with conventional ion exchange results. Reproducibility of the new method has been determined on a typical food type sample.

Sleep and wakefulness in aircrew before and after transoceanic flights

Aircrew were studied before and after flying one of two routes: San Francisco (SFO) to London (LHR) or SFO to Tokyo (NRT). After an adaptation night, sleep and daytime sleepiness were objectively measured in SFO and during the first layover (L/O) of the target trip. Baseline sleep was slightly shorter than normally reported for similar age subjects and, for several reasons, is not an ideal basis for subsequent comparison. Nevertheless, L/O sleep periods tended to provide either less total sleep or less efficient sleep. Crewmembers' estimates of their sleep duration correlated well with objective measures, but their estimates of daytime sleepiness correlated poorly with objectively measured sleepiness. During baseline there was a significant midday sleep tendency as measured by the Multiple Sleep Latency Test. This tendency occurred at almost the same time (GMT) on the second L/O day in LHR. Since sleepiness has a persistent rhythm which is maximal twice per day, it is suggested that L/O sleep periods be taken at these times of maximal sleepiness and that peak workload should coincide with the subsequent periods of maximal alertness. Although the overall quality of sleep diminished only slightly on this L/O, it is possible that if this relatively small loss accumulated over successive L/Os, the effects on daytime sleepiness could be measurable.

Dose-related effects of triazolam and flurazepam on a circadian rhythm insomnia

Forty-eight normal subjects had sleep recordings and multiple sleep latency tests (an EEG measure of sleepiness) before and after a 12-hour shift of sleep-wake schedule. After 2 baseline days, subjects postponed sleep until 12:00 noon, then for three 24-hour periods were in bed from 12:00 noon until 8:00 PM. Treatment in parallel groups were administered before shifted sleeps. Sleep disturbance was greatest in the last quarter of shifted nights (6.5 to 8.5 hours after medication). Subjects taking placebo showed significant sleep loss on shifted nights and increased sleepiness the next day. Triazolam, 0.5 mg, reversed the sleep loss and consequent daytime sleepiness associated with the shifted sleep schedule. Triazolam, 0.25 mg, was not significantly better than placebo. In a dose-related manner, flurazepam mitigated the insomnia, but carryover effects left both dose groups more sleepy than were the placebo control subjects. Whether these laboratory results are applicable to clinically occurring forms of transient insomnia remains to be seen.

PITC derivatives in amino acid analysis

Refined methods for separating PTC-amino acids on reverse phase columns may pose a challenge to traditional ion exchange techniques.

Correlation between adriamycin-induced augmentation of interleukin 2 production and of cell-mediated cytotoxicity in mice

Based on the observation that spleen cells from Adriamycin-treated mice could develop augmented levels of cytotoxic T-lymphocyte activity in response to heat-treated and/or X-irradiated alloantigens, it was postulated that modulations in soluble mediators could be involved in this phenomenon. In fact, in this study Adriamycin-induced increases in the levels of prostaglandin E2 and interleukin 2 activity have been observed with isolated cells. The "interleukin 2-like" activity was indistinguishable from that of partially purified interleukin 2 in terms of ability to restore responsiveness to experimentally inhibited primary alloantigen response cultures and to maintain long-term cultures of activated T-cells. Furthermore this latter activity was completely ablated by antiinterleukin 2 monoclonal antibody. While the modification in prostaglandin E2 production did not appear to play a role in determining augmentation of cytotoxic T-cell activity, the modification in interleukin 2 production was consistent with the possibility that this is a primary mechanism of Adriamycin-induced augmented cell-mediated cytotoxicity.

Natural antitumor defense system of the murine liver

Murine nonparenchymal liver cells from various genetic strains isolated by collagenase digestion and differential sedimentation contain both lymphocytes and macrophages. Nonparenchymal liver cells as well as spleen cells, mononuclear blood cells, and peritoneal exudate cells from C3HeB/FeJ mice were tested for natural cytotoxicity against YAC-1 (sensitive to NK cells) and P815 (resistant to NK cells) tumor cell lines. Resident peritoneal exudate cells exerted no cytotoxicity against either tumor cell, whereas spleen and mononuclear blood cells lysed only YAC-1. In contrast, nonparenchymal liver cells lysed both YAC-1(4 h) and P815 (18 h) tumor cells. Treatment of nonparenchymal liver cells with anti-asialo GM1 and complement abolished the antitumor activity against both tumor cell lines but not the phagocytic activity. Nonadherent nonparenchymal liver cells exerted greater cytotoxicity against YAC-1 tumor cells but little cytotoxicity against P815 tumor cells when compared with unfractionated cells. Adherent nonparenchymal liver cells (macrophages) from untreated mice exerted no antitumor activity against either tumor cell. In contrast, adherent nonparenchymal liver cells from Corynebacerium parvum treated mice were directly cytotoxic to P815 tumor cells. Spleen cells that are normally not cytotoxic to P815 tumor cells (18 h) became cytotoxic when mixed with adherent nonparenchymal liver cells from untreated mice. These results indicate that the tumoricidal effector cell in nonparenchymal liver cells from untreated mice appears to be the NK cell. Apparently, murine liver macrophages from untreated mice do not have tumoricidal activity per se but can "activate" NK cells to kill tumor cells normally resistant to NK cells.

Conformational effects in the reversed-phase liquid chromatography of ribonuclease A

This paper examines the reversed-phase liquid chromatographic behavior of ribonuclease A (RNase) using an n-butyl chemically bonded phase and a gradient of 10 mM H3PO4 and l-propanol. At a column temperature of 25 degrees C, a broad band followed by an overlapped late-eluting sharp peak is observed. As the temperature is raised, the sharp peak grows at the expense of the broad band until at 37 degrees C, only a single narrow-eluting band is found. Using an absorbance ratio of A288/A254, it is demonstrated that the broad band represents a folded or native state of RNase and the late-eluting band a denatured state. Based on postcolumn absorbance ratio changes in the denatured state as a function of time and the known behavior of the protein, reversible refolding or renaturation is proposed to take place in solution. RNase is denatured upon adsorbing to the bonded phase, and upon migration down the column, reversible refolding takes place in the mobile phase. The relaxation time for native state formation is assumed to be comparable to the time spent by RNase in the mobile phase. As temperature is raised, both the native and denatured states exist at equilibrium in solution, thus slowing the refolding process, until at 37 degrees C only the denatured peak appears. Changes in peak shape with flow rate provide further evidence for this model. The use of HCl or H2SO4 instead of H3PO4 yields similar results except that the temperature at which only the denatured peak is observed follows the order of salt stabilization of the native state.

Effects of alprazolam and diazepam on the daytime sleepiness of non-anxious subjects

Eighteen non-anxious volunteers underwent sleep recordings and daytime tests of sleepiness, performance, and mood while receiving, either alprazolam 0.5 mg b.i.d. or diazepam 5 mg b.i.d. for 7 consecutive days. Recordings and tests were done before treatment and on the 1st and 7th days of treatment. Nocturnal sleep changes were similar for both groups; there were no statistically significant changes in mood. However, levels of daytime sleepiness differed. Alprazolam subjects showed more daytime sedation than diazepam subjects on treatment day 1, but showed a significant decrease in Day 1-7 daytime sedation. Although diazepam subjects were less sedated at the onset, they showed no tolerance to this effect; thus by treatment day 7, the two groups did not differ in levels of daytime sleepiness. Results suggested that tolerance to alprazolam's sedative effects (which develops during the 1st week of treatment) may be separable from tolerance to its antianxiety effects (which develops after at least 4 weeks). As daytime sedation is common and potentially dangerous with most anxiolytics, selective tolerance to this side effect is highly desirable.

Buspirone: an anxiolytic without sedative effect

Twelve volunteers with a complaint of chronic insomnia participated in a placebo-controlled, double-blind, crossover study of the effects of buspirone t.i.d. on sleep pattern and daytime function. The drug was tested alone and in combination with flurazepam or triazolam. Buspirone alone did not impair objective measures of daytime wakefulness or performance. Impaired alertness was seen the day after bedtime administration of flurazepam but not after triazolam; buspirone did not alter these effects. Buspirone did not affect the Multiple Sleep Latency Test, a sensitive measure of changes in daytime alertness.

Rapid analysis of amino acids using pre-column derivatization

A new approach to the pre-column derivatization and analysis of amino acids is described. The method is based upon formation of a phenylthiocarbamyl derivative of the amino acids. The derivatization method is rapid, efficient, sensitive, and specific for the analysis of primary and secondary amino acids in protein hydrolyzates. The liquid chromatographic system allows for the rapid, bonded-phase separation with ultraviolet detection of the common amino acids with 12-min analysis time and a 1-pmol sensitivity.

Sequence analysis of derivatized peptides by high-performance liquid chromatography-mass spectrometry

N-Acetyl-N,O,S-permethylated derivatives of oligopeptides were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS) using a moving belt interface. A heated-gas nebulizer was employed for sample deposition, thus permitting the effective use of a water-methanol gradient covering the range from 5% to 95% water at mobile phase flow-rates of 0.5 ml/min. We demonstrate in this paper that it is possible to sequence the octapeptide derived from the C-chain of glucagon by HPLC-MS analysis of a permethylated enzymatic hydrolysate of this peptide using overlap information from the mass spectral patterns. Moreover, it is shown that peptides not readily amenable to analysis by gas chromatography-MS can be analyzed using this approach. Preliminary results suggest that N-acetyl-methyl ester derivatives of oligopeptides may in specific cases also be a useful alternative for HPLC-MS analysis of complex oligopeptide mixtures.