Synthesis and secretion of apolipoprotein E by cultured human keratinocytes

Non-polar lipids are synthesized by keratinocytes in the epidermis and transported to the extracellular space where they contribute to formation of a permeability barrier. Transport of non-polar lipids in other organs and tissues usually occurs with the lipid complexed to an apolipoprotein. In this study we set out to learn if apolipoprotein E is produced by human epidermal keratinocytes in culture. Analysis of total cellular RNA from cultured keratinocytes showed the presence of human apolipoprotein E mRNA at concentrations ranging from 2.5 to 35 molecules/cell. The cells secrete a protein identified as apo E on the basis of molecular weight, isoform pattern, and immunoreactivity. Enzyme linked immunosorbent assay of media from keratinocyte cultures indicated that apolipoprotein E is secreted at a rate of 0.92 ng/h/10(6) cells.

Immunization against Trypanosoma cruzi: adjuvant effect of glucan

Trypanosoma cruzi, the causative agent of Chagas' disease, infects humans and animals in tropical, subtropical and some temperature regions of the western hemisphere. At present, there is no effective vaccine for T. cruzi infection. Glucan, a beta-1,3 polyglucose biological response modifier, possesses significant adjuvant activity. The present study investigated the adjuvant activity of particulate glucan when combined with a vaccine of glutaraldehyde-killed T. cruzi culture forms. ICR/HSD mice (20 g) were injected s.c. with glutaraldehyde-killed T. cruzi on days 21, 14 and 7 prior to challenge with 50 T. cruzi blood forms. Particulate glucan (1 mg/mouse) was administered s.c. either alone or in conjunction with T. cruzi vaccine. Isovolumetric dextrose served as control. Dextrose, glucan or T. cruzi vaccine as single treatment regimens showed 100% mortality with 20.5, 21.4 and 21.6 day median survival times, respectively. In contrast, glucan administered with T. cruzi vaccine showed an 85% (P less than 0.01) survival at 275 days post-challenge. In addition, the number of T. cruzi observed in the blood of glucan--T. cruzi immunized mice was lower than the appropriate controls. However, immunized mice which survived at 275 days were positive for the presence of T. cruzi by xenodiagnosis. Histopathologic evaluation of glucan--T. cruzi mice revealed no parasites or cardiac pathology, but a mild splenic hyperplasia and inflammation of skeletal muscle were noted. In subsequent studies, mice were immunized with the same regimen of glucan--T. cruzi and challenged with 500 or 5000 T. cruzi. Glucan significantly (P less than 0.05) increased survival as denoted by 60% and 50% survival in the glucan-T. cruzi group vs 0% in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Guanosine 5'-monophosphate modulates gating of high-conductance Ca2+-activated K+ channels in vascular smooth muscle cells

Ca2+-activated K+ channels (PKCa channels) account for the predominant K+ permeability of many types of smooth muscle cells. When activated, they oppose depolarization due to Na+ and Ca2+ channel activity. Several vasodilatory agents that increase intracellular cGMP levels (e.g., nitroprusside, adenosine, and atrial natriuretic factor) enhance the activity of these high-conductance PKCa channels in on-cell patches of bovine aortic smooth muscle cells. In addition, dibutyryl-cGMP (1.0 mM) causes a similar increase in channel activity. To pursue the mechanism of channel modulation by these agents, a series of guanine and adenine nucleotides were evaluated by using inside-out excised patches. Whereas cAMP, AMP, ADP, and ATP were ineffective, all of the corresponding guanine nucleotides potentiated PKCa channel activity when tested at a high concentration (500 microM). However, only GMP consistently enhanced channel activity in the 1-100 microM range by increasing the percent open time and frequency of opening of these channels over a wide range of potentials and Ca2+ levels without affecting single-channel conductance. Thus, GMP is a potent modulator of PKCa channels and it, rather than cGMP, may mediate the action of the vasodilators examined in this study.

Cytogenetics of childhood T-cell leukemia

The karyotypes of 57 cases of childhood T-cell acute lymphoblastic leukemia (ALL) were analyzed to establish the cytogenetic profile in this disease. Three questions were of particular interest. Do the chromosomal changes in T-cell ALL preferentially affect bands where genes encoding the T-cell receptor for antigen (TCR) have been mapped? Do alterations involving the TCR gene regions appear with any notable frequency in B-progenitor ALL? Do chromosomal abnormalities in this disease relate to stage of T-cell ontogeny? A relatively high proportion of cases (65%) had a pseudodiploid karyotype at presentation, the majority (58%) characterized by a translocation. The overall frequency of translocations was 44%, comparable to that among all banded cases of ALL seen in our laboratory. Hypodiploidy and hyperdiploidy were exceedingly rare (only four of 57 cases); 16 cases (28%) had apparently normal karyotypes. In half the cases with a translocation (14 of 24), the breakpoints were in regions to which the alpha and beta chain TCR genes have been mapped. Chromosomal breakpoints that were consistently observed in the vicinity of TCR gene loci were 7q32-q36 (TCR beta chain; n = 8), 14q11-q13 (TCR alpha chain; n = 6); other frequent breakpoints were 9p13-pter (n = 8) and 6q15-qter (n = 9). Chromosomal alterations occurred near TCR gene loci significantly more often in T-cell cases than in a comparison group of 335 patients with B-cell precursor ALL (26% v 1.5%, P = .0001). Stage I thymocyte development (CD7+, CD2+, CD5+, CD1-, CD3-, CD4-, CD8-) was noted in 23 cases, stage II (CD7+, CD2+, CD5+, CD1+, CD3-, CD4 +/-, CD8 +/-) in 25 cases, and stage III (CD9+, CD2+, CD1-, CD5+, CD3+, and either CD4+ or CD8+) in nine cases. The only statistically significant associations between cytogenetic findings and T-cell ontogeny were a higher frequency of normal karyotypes in cases with stage I thymocytes, and of pseudodiploidy in stage II cases. There was no apparent relationship between particular translocations and level of thymocyte maturation. Our findings indicate that most children with T-cell ALL have pseudodiploid karyotypes, although a surprisingly high percentage lack demonstrable abnormal clones. Specific chromosomal changes do not appear to be related to discrete stages of T-cell ontogeny as defined in this study, but they occur preferentially in bands containing TCR genes.

Molecular studies of T-lymphocytes from cattle infected with bovine leukemia virus

Although bovine leukemia virus (BLV) is mainly associated with infections of B-lymphocytes, we have previously reported the statistically significant increase in the T-lymphocytes obtained from BLV-infected asymptomatic aleukemic (AL) cattle. In this report the presence of BLV provirus in the DNA of immunoaffinity purified T-lymphocytes from AL animals was assessed using a highly specific radiolabelled (32P) BLV-DNA provirus probe and solid phase DNA hybridization. The BLV provirus was found in the DNA of the peripheral blood mononuclear cells of all AL animals tested and three of the four purified T-lymphocyte preparations from these animals. The purified T-lymphocyte preparations used in this study contained less than 4% detectable B-lymphocytes. One animal had no detectable B-lymphocytes in the purified T-lymphocyte preparation and the DNA from these cells also gave positive hybridization results. The lymphocyte blastogenesis assay was then used as an indicator of the functional ability of lymphocytes from these BLV-infected AL cattle to respond to mitogenic stimuli. The responsiveness of lymphocytes from these animals to the mitogens concanavalin A (Con A), phytohemagglutinin (PHA), and pokeweek mitogen (PWM) was comparable to that of lymphocytes from BLV-negative animals when changes in 3H-thymidine uptake (c.p.m.) were used as measurement of mitogenic-induced blastogenesis. This indicated that infection of the T-lymphocytes by BLV does not appear to alter the overall response of the lymphocyte populations to mitogenic stimuli. High levels of spontaneous blastogenesis in the absence of mitogenic stimulation were observed for lymphocyte preparations of AL animals. The reason for this proliferation of lymphocytes is unclear; however, sera from these AL animals were found to contain a blastogenesis-augmenting factor(s) when added to lymphocytes from BLV-negative control animals in the presence of Con A, PHA and PWM.

Cooperative turning on of myosin subfragment 1 adenosinetriphosphatase activity by the troponin-tropomyosin-actin complex

In the field of muscle regulation, there is still controversy as to whether Ca2+, alone, is able to shift muscle from the relaxed to the fully active state or whether cross-bridge binding also contributes to turning on muscle contraction. Our previous studies on the binding of myosin subfragment 1 (S-1) to the troponin-tropomyosin-actin complex (regulated actin) in the absence of ATP suggested that, even in Ca2+, the binding of rigor cross-bridges is necessary to turn on regulated actin fully. In the present study, we demonstrate that this is also the case for the turning on of the acto.S-1 ATPase activity. By itself, Ca2+ does not fully turn on the acto.S-1 ATPase activity; at low actin concentration, there is almost a 10-fold increase in ATPase activity when the regulated actin is fully turned on by the binding of rigor cross-bridges in the presence of Ca2+. This large increase in ATPase activity does not occur because the binding of S-1.ATP to actin is increased; the binding of S-1.ATP is almost the same to maximally turned-off and maximally turned-on regulated actin. The increase in ATPase activity occurs because of a marked increase in the rate of Pi release so that when the regulated actin is fully turned on, Pi release becomes so rapid that the rate-limiting step precedes the Pi release step. These results suggest that, while Ca2+, alone, does not fully turn on the regulated actin filament in solution, the binding of rigor cross-bridges can turn it on fully. If force-producing cross-bridges play the same role in vivo as rigor cross-bridges in vitro, there may be a synergistic effect of Ca2+ and cross-bridge binding in turning on muscle contraction which could greatly sharpen the response of the muscle fiber to Ca2+.

Immune production of interferon by cultured peripheral blood mononuclear cells from calves infected with BHV1 and PI3 viruses

Peripheral blood mononuclear cells (PBMC) from calves infected with bovine herpesvirus type 1 (BHV1) or parainfluenza 3 virus (PI3) were cultured in vitro in the presence of inactivated specific antigen presented on MDBK cells. In the presence of inactivated antigen, PBMC from both BHV1-infected and control calves produced interferon (IFN)-alpha in 24 hour cultures. Altering the culture conditions did not result in the detection of immune-specific IFN produced by mononuclear cells from BHV1-infected calves. However, spontaneous IFN was detected in the absence of antigen in 24 hour cultures from infected animals: this IFN was pH 2 labile and completely neutralised by antiserum to recombinant bovine IFN-gamma. Spontaneous IFN-gamma production was only seen in calves following a second BHV1 inoculation, given four to seven weeks after the primary dose. In contrast PBMC cultures from PI3 virus-infected calves did not produce IFN-gamma spontaneously, but did so in cultures which contained inactivated PI3 antigen. Mononuclear cells from control animals failed to produce either IFN-alpha or -gamma when cultured with inactivated PI3 virus. IFN-gamma was detected in PBMC cultures after the primary infection, with no increase in production occurring following subsequent PI3 virus inoculations. Immunospecific production of IFN-gamma provides a simple method for monitoring cell-mediated immunity in BHV1- and PI3 virus-infected calves and can be used for evaluating the efficacy of vaccines against these viruses.

Enumeration of T and B lymphocytes in bovine leukemia virus-infected cattle, using monoclonal antibodies

Monoclonal antibodies and microfluorimetry were used to determine the absolute number of B and T lymphocytes in the blood of bovine leukemia virus (BLV)-infected cows. The blood lymphocyte populations from BLV-infected cows were significantly higher than those from BLV-negative cows. The increase in the lymphocyte population in 3 BLV-infected nonlymphocytotic cows was attributed to a significant increase in the number of T lymphocytes; in 3 BLV-infected persistently lymphocytotic cows, the increase was attributed to a significant increase in the number of B and T lymphocytes. One persistently lymphocytotic cow had a high lymphocyte count, and lymphocytes from this cow contained cells that appeared to stain with markers specific for bovine B and T lymphocytes. We concluded that infection of cattle with the B-cell lymphotropic retrovirus, BLV, not only affected B cells, but also T cells.

The role of complement in glucan-induced protection against septic shock

Previous studies from our laboratory have shown that glucan will significantly enhance survival, decrease bacteremia, maintain reticuloendothelial function, and reduce histopathology in a murine model of gram-negative septic shock [1]. The present study was undertaken to evaluate the role of complement in glucan-enhanced protection against septic shock. AKR/J mice, which are congenitally C5-deficient, and ICR/HSD mice that were complement-depleted by treatment with purified cobra venom factor (CVF), were injected IP with glucan (50 mg/kg) on days 5 and 3 prior to IP challenge with 1 X 10(8) E. coli. Survival data indicated that glucan (p less than 0.05) increased survival in both C5-deficient and complement-depleted mice. Glucan prophylaxis resulted in a neutrophilic leukocytosis 8 h following E. coli challenge. However, glucan did not alter bone marrow proliferation. We conclude that, 1) glucan's protective effect on survival is not dependent on complement, 2) complement is not required for glucan-induced neutrophilic leukocytosis in this model, and 3) glucan does not enhance bone marrow proliferation in complement-deficient mice.

Apolipoprotein (apo) A-I production and mRNA abundance explain plasma apoA-I and high density lipoprotein differences between two nonhuman primate species with high and low susceptibilities to diet-induced hypercholesterolemia

Earlier studies have shown that African green monkeys develop a more modest hypercholesterolemia, higher high density lipoprotein (HDL) concentrations, and less atherosclerosis than cynomolgus monkeys fed diets with the same cholesterol content. In the present study, cynomolgus monkeys were fed less cholesterol than was fed to African green monkeys to induce equivalent hypercholesterolemia in both species. African green monkeys still had 2-fold higher plasma HDL cholesterol concentrations and 2.7-fold higher plasma apolipoprotein (apo) A-I concentrations. Therefore, the higher HDL concentration in African green monkeys appears to result from factors that act independently of dietary cholesterol intake or total plasma cholesterol concentration. Two aspects of HDL production were examined to determine the metabolic basis of the species difference in HDL concentration. The rate of hepatic apoA-I secretion, as estimated by the accumulation of apoA-I in the medium during recirculating liver perfusion, was 5-fold higher in livers of African green monkeys. In addition, the concentration of apoA-I mRNA was 2-fold higher in the liver and 3.7-fold higher in the intestine of African green monkeys. Taken together, these findings indicate that differences in apoA-I production in the liver and small intestine are large enough to be responsible for the differences in the plasma concentrations of HDL and apoA-I between these species. Factors which regulate apoA-I secretion, including modulation of tissue apoA-I mRNA concentrations, are important determinants of plasma HDL concentrations and may contribute to the relative resistance of African green monkeys to dietary cholesterol-induced hypercholesterolemia and atherosclerosis. ApoA-I mRNA was also detected at low levels in the kidney and testis of African green and cynomolgus monkeys but not in the adrenal or brain. The tissue distribution and abundance of apoA-I mRNA in peripheral tissues was very different than that seen for apoE mRNA. Kidney and testis apoA-I mRNAs were the same size as liver apoA-I mRNA when examined by Northern blot analysis. Testis apoA-I mRNA appeared to be functionally active as judged by its presence in cytoplasmic polyribosomes. The low levels of apoA-I expression in kidney and testis are unlikely to contribute significantly to the plasma apoA-I pool but might function in some aspect of local lipid metabolism within these tissues.

Isochromosome 17q in childhood acute lymphoblastic leukemia: an adverse cytogenetic feature in association with hyperdiploidy?

Isochromosome 17q is associated with the blastic phase of Philadelphia chromosome-positive chronic myeloid leukemia, but its significance in acute lymphoblastic leukemia (ALL) is unknown. We studied 469 consecutive cases of newly diagnosed ALL with completely banded leukemic cell chromosomes, identifying eight that had the isochromosome. The presenting leukocyte counts of these patients ranged from 1.7 to 130.2 x 10(9)/L (median 7 x 10(9)/L). The morphologic classification of their blast cells was L1 in six cases and L2 in the others; the majority of cases had the common ALL phenotype, whereas two were pre-B. Strikingly, hyperdiploidy greater than 50 chromosomes, a favorable prognostic feature in ALL, characterized all but one of the cases with i(17q), compared with 113 of 461 cases lacking the isochromosome (p less than 0.001). Only four patients, three with relatively brief follow-up times (1, 2, and 8 months), are still in remission. All of the eight previously reported cases of ALL with the i(17q) have failed treatment. These findings suggest that the i(17q) exerts an adverse influence on treatment outcome in ALL, even in hyperdiploid cases with greater than 50 chromosomes.

Soluble glucan and lymphokine-activated killer (LAK) cells in the therapy of experimental hepatic metastases

Previous studies have indicated the efficacy of adoptive immunotherapy utilizing recombinant interleukin-2 (rIL-2) and lymphokine-activated killer (LAK) cells in the treatment of advanced neoplastic disease. However, this therapeutic approach is associated with considerable toxicity, primarily due to the systemic administration of rIL-2. The present study was undertaken to determine the efficacy of a newly developed water-soluble glucan, when administered in combination with LAK cells, in the therapy of experimental hepatic metastases. Mice were challenged subcutaneously (1 X 10(4) cells) with reticulum cell sarcoma M5076 on day 0. Therapy was initiated on day 15, when a palpable primary tumor mass and hepatic micrometastases were evident, and continued at 3-day intervals up to day 54. Sarcoma-bearing mice received glucan (250 mg/kg) intravenously, either alone or in combination with LAK cells (1 X 10(7)/mouse). Control mice received 5% (wt/vol) dextrose in water. Glucan-LAK cell therapy significantly suppressed primary tumor growth, inhibited the progression of hepatic metastases and prolonged survival in sarcoma-bearing mice. Splenocytes, incubated with rIL-2 for 72 h, exhibited significant natural killer (NK) cell activity and were cytotoxic to sarcoma cells in vitro. Glucan-LAK cell administration resulted in significant increases in splenic NK cell activity and Kupffer cell-mediated tumoricidal activity. In addition, bone marrow proliferation was enhanced following the co-administration of glucan and LAK cells. Due to its nontoxic nature and immunostimulating properties, soluble glucan may prove to be an attractive biological response modifying agent for utilization in adoptive immunotherapy of advanced neoplastic disease.

Effects of age on the adaptive behavior of institutionalized and noninstitutionalized individuals with Down syndrome

The effects of age on the adaptive behavior of individuals with Down syndrome and matched individuals in other diagnostic categories were compared in three studies. The only study that provided evidence of a decline in competence among older individuals with Down syndrome was the one study in which the oldest age category was 60 years and over. In that study, a significant Age X Diagnosis interaction was found for the Motor Development factor of the Client Development Evaluation Report, reflecting a sharp drop in the scores of some of the oldest subjects with Down syndrome. These results resemble those of other recent research in two respects: the age at which the decline in competence occurred and the nature of that decline.

Estrogen-induced destabilization of yolk precursor protein mRNAs in avian liver

In addition to regulating gene expression at the level of transcription, estrogen is generally considered to selectively stabilize induced mRNAs against degradation. As a result of mRNA stabilization, estrogen-induced mRNAs accumulate to much higher levels in target cells, and the encoded proteins are made at much greater rates than would occur on the basis of transcriptional activation alone. The present study examined the effect of estrogen on the stabilities of avian liver mRNAs that code for the yolk precursor proteins apolipoprotein (apo) II and vitellogenin (VTG) II. The results show that the degradation rates of apoII and VTG II mRNAs during hormone withdrawal are dramatically altered by the duration of prior estrogen treatment. During the 2 days required for the hormonal inductions of these mRNAs to new steady states, the turnover rates of both mRNAs were the same in the presence and absence of estrogen (t1/2 = 13 h). This result indicates that mRNA stabilization does not contribute to the extensive accumulation of apoII and VTG II mRNAs. When the duration of estrogen treatment was extended beyond 3 days, however, hormone withdrawal led to the rapid (t1/2 = 1.5 h) and selective destabilization of these mRNAs. This result suggests that estrogen induced a destabilization activity that was only functional following hormone withdrawal. Thus, the point at which estrogen alters mRNA stability is at the level of mRNA degradation. An absence of detectable apoII mRNA degradation intermediates during either the slow or rapid mode of mRNA decay suggests that the rate-limiting step for apoII mRNA turnover is an estrogen-sensitive targeting event that marks the mRNA for rapid degradation.

Effect of glucan on neutrophil dynamics and immune function in Escherichia coli peritonitis

Previous studies from our laboratory have demonstrated that glucan, a nonspecific immunomodulator, modifies the course of murine Escherichia coli peritonitis. The protective effect of glucan was mediated, in part, by macrophages. In the present study, leukocyte dynamics in the peritoneal cavity and peripheral blood of glucan-treated mice following E. coli challenge was examined. Additional studies examined in vitro bone marrow proliferation, as well as phagocytosis and intracellular killing of E. coli by neutrophils following glucan administration. ICR/HSD mice were injected ip with glucan (150 mg/kg) or dextrose (5% w/v) on Days 5 and 3 prior to ip challenge with 1 X 10(8) E. coli. Glucan increased (P less than 0.05) total peritoneal neutrophil numbers prior to and following septic challenge. Examination of peripheral blood revealed that ip glucan treatment in E. coli peritonitis significantly (P less than 0.001) increased the number of circulating neutrophils. Additionally, neutrophils from glucan-treated mice showed increased phagocytosis of E. coli in vitro. Glucan therapy also increased bone marrow proliferation. We conclude that (1) glucan enhances peritoneal neutrophil levels, (2) peripheral blood neutrophils are increased following glucan and E. coli, (3) ip glucan increases bone marrow proliferation, and (4) neutrophils from glucan-treated mice showed enhanced phagocytosis of E. coli in vitro. Thus, the beneficial effect of glucan is mediated not only by activated macrophages, but also by the neutrophilic leukocyte.

Pre-clinical safety evaluation of soluble glucan

Soluble glucan, a beta-1,3-linked glucopyranose biological response modifier, is effective in the therapy of experimental neoplasia, infectious diseases and immune suppression. Currently, soluble glucan is undergoing phase I clinical trials. The present study describes the pre-clinical safety evaluation of soluble glucan in mice, rats, guinea pigs and rabbits. ICR/HSD mice and Harlan Sprague-Dawley rats received a single i.v. injection of soluble glucan in doses ranging from 40 to 1000 mg/kg. Soluble glucan administration did not induce mortality, appearance or behavioral changes in mice or rats. In subsequent studies, mice and guinea pigs were injected i.p. with glucan (250 mg/kg) for 7 consecutive days. ICR/HSD mice gained weight at the same rate as the saline-treated controls. In contrast, guinea pigs receiving i.p. injections of soluble glucan showed a significant (P less than 0.05) 10-13% decrease in weight gain over the 7 day period. No other toxicologic, behavioral or appearance changes were noted. To examine chronic toxicity, soluble glucan was administered twice weekly for a period of 30 or 60 days to ICR/HSD mice in the dose of 40, 200 or 1000 mg/kg. No deaths were observed in any group. Chronic glucan administration did not alter body weight, liver, lung or kidney weight. However, a significant splenomegaly was observed in both the 30 and 60 day study. Histopathologic examination showed no tissue alterations at 40 or 200 mg/kg. However, at 1000 mg/kg a mononuclear infiltrate was observed in the liver. Pyrogenicity testing, employing New Zealand white rabbits, revealed that parenteral glucan administration (5 mg/kg) did not significantly alter body temperature. These data indicate that the systemic administration of soluble glucan, over a wide dose range, does not induce mortality or significant toxicity, an important consideration in preparing soluble glucan for parenteral administration to human populations.

Correlation of karyotype and immunophenotype in childhood acute lymphoblastic leukemia

To correlate leukemic cell karyotype with immunophenotype, we studied 364 children with acute lymphoblastic leukemia (ALL). A prognostically favorable cytogenetic feature, hyperdiploidy greater than 50 chromosomes, was found in 33% of cases classified as common ALL antigen positive (CALLA+) early pre-B (common) ALL, in contrast to 18% of pre-B cases (P = .012), 5% of T cell cases (P less than .001), and none of the B cell cases (P less than .001) or cases of CALLA negative (CALLA-) early pre-B ALL (P = .002). The frequency of translocations, an adverse cytogenetic feature, was significantly lower in CALLA+ early pre-B ALL cases (35%) than in B cell (100%; P less than .0001), pre-B (59%; P less than .001), or CALLA- early pre-B (62%; P = .016) cases. Thus, patterns of chromosomal change differ widely among the major immunophenotypic groups of ALL and may account for reported differences in responsiveness to treatment.

tdic(9;12): a nonrandom chromosome abnormality in childhood B-cell precursor acute lymphoblastic leukemia: a Pediatric Oncology Group Study

In a review of 432 children with newly diagnosed acute lymphoblastic leukemia (ALL), we identified a new nonrandom translocation, tdic(9;12)(p1?1;p1?2), in the leukemic marrow cells of eight patients. Seven had hypodiploid karyotypes that lacked chromosomes 9 and 12 and contained a der(12), tdic(9;12); the eighth had a pseudodiploid karyotype with two normal 9 chromosomes, one normal 12 and the der(12), tdic(9;12). Abnormalities involving chromosomes other than 9 and 12 were noted in four of the eight patients. All cells with the tdic(9;12) expressed both the common ALL antigen and HLA-DR. Cytoplasmic immunoglobulin, a marker of pre-B ALL, was detected in one case with the tdic(9;12) but was absent in the other seven. Our results suggest that the tdic(9;12)(p1?1;p1?2) rearrangement is specifically associated with leukemic B cell precursors.

Chemoimmunotherapy of experimental hepatic metastases

Previous studies from our laboratory have demonstrated that particulate glucan is efficacious in the therapy of a syngeneic murine reticulum cell sarcoma (M5706), which specifically metastasizes from its primary site to the liver. The present study was undertaken to examine the therapeutic efficacy of a newly developed soluble glucan, in combination with cyclophosphamide in the treatment of hepatic metastatic disease. Male C57Bl/6J mice were injected subcutaneously on Day 0 with 1 x 10(4) sarcoma cells. Glucan (200 mg per kg i.v.), cyclophosphamide (45 mg per kg i.p.) or glucan and cyclophosphamide were administered beginning on Day 20, when hepatic metastases were evident, and continued at 3-day intervals up to Day 50. Combined therapy with glucan and cyclophosphamide resulted in reduction of hepatic metastatic lesions on Day 36, compared to control. Survival data revealed that the combination of glucan and cyclophosphamide significantly (p less than 0.001) extended median survival time and the time to 100% mortality in an additive fashion, when compared to either therapy alone. Glucan-cyclophosphamide therapy was also effective in decreasing primary tumor weight to a level that was significantly (p less than 0.05) less than when therapy was initiated. In vitro studies revealed that Kupffer cell tumoricidal activity against sarcoma was increased (p less than 0.05) following glucan and cyclophosphamide. Glucan and cyclophosphamide also enhanced bone marrow proliferation and splenocyte response to mitogens in vitro. Additionally, glucan was observed to exert a direct cytostatic effect on sarcoma in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)