Characterization and modulation of [125I]iberiotoxin-D19Y/Y36F binding in the guinea-pig urinary bladder

The radioligand binding characteristics of the Ca(2+)-activated K(+) channel ligand [125I]iberiotoxin-D19Y/Y36F were examined in guinea-pig urinary bladder membranes. Saturation analysis revealed a single class of high affinity binding sites in the bladder with a K(D) value of 45.6 pM and a B(max) value of 112 fmol/mg protein. Specific binding was displaced by unlabeled iberiotoxin and penitrem A, but not by blockers of other classes of K(+) channels including alpha-dendrotoxin, margatoxin and apamin. The indole alkaloids, paxilline and verruculogen, significantly increased binding by 4.5- and 4.3-fold, respectively. Tetraacetic acid derivatives such as ethylenediamine tetraacetic acid and ethyleneglycoltetraacetic acid enhanced specific [125I]iberiotoxin-D19Y/Y36F binding about 2.5-fold, which was not attributable to calcium chelation. This increase was due to a significant change in ligand binding affinity (K(D)=6.3 pM), but not due to a change in the B(max), indicating that these compounds may enhance toxin binding via allosteric interactions. Collectively, these results demonstrate that the binding sites for [125I]iberiotoxin-D19Y/Y36F present in the urinary bladder shows a pharmacological profile typical of maxi-K(+) channels and can be modulated, not only by previously known indole alkaloids, but also by tetraacetic acid analogs.

Prostatic levels of tocopherols, carotenoids, and retinol in relation to plasma levels and self-reported usual dietary intake

This study evaluated how prostatic levels of antioxidants relate to plasma levels and self-reported usual dietary intake. Definition of these relations may aid in interpreting studies of antioxidant exposure and prostate cancer risk. Between July 1996 and April 1997, plasma and prostatic tissue levels of tocopherols, carotenoids, and retinol were measured in 47 men undergoing radical prostatectomy or transurethral prostatectomy at Loyola University Medical Center, Maywood, Illinois, and an affiliate hospital. Dietary intake was measured by using a 122-item version of the Block Health Habits and History Questionnaire, and correlations were assessed with Pearson's coefficients. Prostatic levels of tocopherols and carotenoids (but not retinol) were significantly correlated with plasma levels (r= 0.31-0.56, p < 0.05-0.0001); the strongest correlations were associated with lycopene, beta-carotene, and gamma-tocopherol (0.56, 0.54, and 0.52, respectively; p < 0.0001). Relative concentrations of tocopherols and carotenoids in prostate tissue were proportionate to those in plasma. No correlation between prostatic levels and reported dietary intake was observed (r = -0.09 to 0.16, p < not significant). Adjustment for energy intake, body mass index, and serum lipids did not impact these relations. These results suggest that plasma levels of tocopherols and carotenoids better reflect prostatic exposure than self-reported usual dietary intake.

Macrophage cell-conditioned medium promotes cholinergic differentiation of undifferentiated progenitors and synergizes with nerve growth factor action in the developing basal forebrain

Conditioned medium from stimulated microglia and from the monocyte/macrophage cell line (RAW 264.7; MC-CM) promotes the differentiation of cholinergic neurons from undifferentiated progenitors in the septal nuclei and adjacent basal forebrain (BF). We have studied the regulation of this process by measuring the activity of choline acetyltransferase (ChAT) in cultured BF taken from embryonic day 16 rat brain. Inhibition of either xanthine oxidase with allopurinol or nitric oxide synthase with N(G)-monomethyl-l-arginine produces a small but significant improvement in the efficacy of MC-CM while inclusion of pyrrolidine dithiocarbamate, a hydroxyl radical scavenger widely used as an antioxidant, lowers MC-CM-induced ChAT activity. Addition of nerve growth factor (NGF) but not brain-derived neurotrophic factor or glial-derived neurotrophic factor together with MC-CM has a synergistic effect on both ChAT activity and ChAT mRNA, raising ChAT activity as much as 29-fold and ChAT mRNA almost 15-fold. While MC-CM raised mRNA for trkA, the effect was not synergistic with NGF. mRNA for the common neurotrophin receptor (p75NTR) showed a modest synergistic increase. Blockade of the Ras/Raf/ERK [extracellular signal-regulated kinase, also known as mitogen-activated protein [(MAP) kinase] signal transduction pathway with either PD28059 (an inhibitor of MAP kinase/ERK kinase kinase or MEK) or N-acetyl-S-farnesyl-l-cysteine (an inhibitor of Ras farnesylation and, hence, activation) inhibited the action of MC-CM. Moreover, a subpopulation of cells responded rapidly to MC-CM with an increased appearance of phosphorylated ERK. Because NGF also utilizes this pathway, synergy may occur along this signal transduction pathway.

Enhanced immune response to the melanoma antigen gp100 using recombinant adenovirus-transduced dendritic cells

Glycoprotein 100 (gp100) is one of a series of well-characterized human melanoma-associated antigens expressed by most melanoma cells. Immunization of C57BL/6 mice with an adenovirus (Ad) vector encoding human gp100 (Adhgp100) has been shown to induce limited protective immunity against challenge with murine melanoma B16 cells. In the current study we determined whether gp100-specific immunity can be enhanced using bone-marrow-derived dendritic cells (DCs) transduced with Adhgp100 ex vivo. Subcutaneous injection of Adhgp100-infected DCs resulted in potent T-cell-mediated protective immunity and a greater than 80% reduction of established tumors when administered to B16 tumor-bearing hosts. Compared to direct injection of Adhgp100 vector alone, immunization with Adhgp100-infected DCs induced markedly greater antitumor activity. In vitro CTL analysis demonstrated that DC-Adhgp100 immunization activated both CD4(+) and CD8(+) CTLs, while no lytic activity was generated by vaccination with Adhgp100 alone. In vivo depletion of CD4(+) T cells, but not CD8(+) T cells, completely abrogated CTL activity, suggesting that Adhgp100-transduced DCs result in activation of both CD4(+) and CD8(+) CTLs via a CD4(+)-dependent mechanism. We speculate that this improved efficacy of Adhgp100-transduced DCs compared to direct immunization with Adhgp100 may be the result of direct DC-mediated CD4(+) T cell activation. These results emphasize the importance of CD4(+) T cells in the development of therapeutic antigen-specific cancer vaccines.

High-monounsaturated fatty acid diets lower both plasma cholesterol and triacylglycerol concentrations

BACKGROUND

Low-fat diets increase plasma triacylglycerol and decrease HDL-cholesterol concentrations, thereby potentially adversely affecting cardiovascular disease (CVD) risk. High-monounsaturated fatty acid (MUFA), cholesterol-lowering diets do not raise triacylglycerol or lower HDL cholesterol, but little is known about how peanut products, a rich source of MUFAs, affect CVD risk.

OBJECTIVE

The present study compared the CVD risk profile of an Average American diet (AAD) with those of 4 cholesterol-lowering diets: an American Heart Association/National Cholesterol Education Program Step II diet and 3 high-MUFA diets [olive oil (OO), peanut oil (PO), and peanuts and peanut butter (PPB)].

DESIGN

A randomized, double-blind, 5-period crossover study design (n = 22) was used to examine the effects of the diets on serum lipids and lipoproteins: AAD [34% fat; 16% saturated fatty acids (SFAs), 11% MUFAs], Step II (25% fat; 7% SFAs, 12% MUFAs), OO (34% fat; 7% SFAs, 21% MUFAs), PO (34% fat; 7% SFAs, 17% MUFAs), and PPB (36% fat; 8% SFAs, 18% MUFAs).

RESULTS

The high-MUFA diets lowered total cholesterol by 10% and LDL cholesterol by 14%. This response was comparable with that observed for the Step II diet. Triacylglycerol concentrations were 13% lower in subjects consuming the high-MUFA diets and were 11% higher with the Step II diet than with the AAD. The high-MUFA diets did not lower HDL cholesterol whereas the Step II diet lowered it by 4% compared with the AAD. The OO, PO, and PPB diets decreased CVD risk by an estimated 25%, 16%, and 21%, respectively, whereas the Step II diet lowered CVD risk by 12%.

CONCLUSION

A high-MUFA, cholesterol-lowering diet may be preferable to a low-fat diet because of more favorable effects on the CVD risk profile.

[The testing methods of the medical ultrasonic linear array transducer]

This paper explores the testing methods of the linear array transducer in regard to its integrality, Uniformity and independence.

Endomorphin-1 mediates 2 Hz but not 100 Hz electroacupuncture analgesia in the rat

This work was designed to elucidate the possible involvement of endogenous endomorphin-I (EM1) in analgesia induced by electroacupuncture of low or high frequencies. Taking radiant heat tail flick latency (TFL) as an indication of nociception, rats were subjected to intrathecal (i.t.) injection of 10 microl antiserum against EM1 (EM1-AS) or normal rabbit serum (NRS, as control) and then followed by 2 or 100 Hz electroacupuncture stimulation for 30 min. The analgesia induced by 2 Hz electroacupuncture was attenuated by i.t. injection of EM1-AS at 1:10 and 1:100 but not at 1:1000 dilution. No such suppressive effect was observed for 100 Hz EA analgesia when EM1-AS was injected i.t. at any dilutions. These results indicate that EM1 is involved in 2 Hz but not 100 Hz electroacupuncture analgesia at spinal level.

Effects of stuffer DNA on transgene expression from helper-dependent adenovirus vectors

We have analyzed transgene (lacZ) expression from a first-generation adenovirus (Ad) vector in comparison to helper-dependent (hd) Ads deleted for various portions of the viral coding sequences and generated by using the Cre/loxP helper-dependent system (R. J. Parks et al., Proc. Natl. Acad. Sci. USA 93:13565-13570, 1996). An hd vector deleted for approximately 70% of the Ad genome (AdRP1001) provided levels and durations of transgene expression similar to those of a control first generation Ad vector containing an identical expression cassette. Deletion of all Ad sequences from the hdAd and replacement with a approximately 22-kb fragment of lambda DNA resulted in a decrease in the level and duration of lacZ expression which could not be reversed by the inclusion of a matrix attachment region. However, substitution of the lambda stuffer in the fully deleted hdAd with sequences from the human hypoxanthine-guanine phosphoribosyltransferase gene resulted in significantly improved transgene expression. In vitro assays for cytotoxic T lymphocytes (CTL) directed against putative peptides encoded by the vector backbone showed that, although CTL were generated against the vector containing the lambda DNA, no such CTL were generated against the vector containing the hypoxanthine-guanine phosphoribosyltransferase (HPRT) sequences. Surprisingly, the rate of loss of the HPRT- and lambda-containing vectors from mouse liver was similar, despite the differences in expression kinetics, indicating that the lambda stuffer-directed CTL were inefficient at eliminating the transduced cells. Thus, the nature of the DNA backbone of hdAds can have important effects on the functioning of the vector. Since most fully deleted vectors require "stuffer" DNA as part of the vector backbone to maintain optimum vector size, these observations must be taken into account in the design of hdAd vectors.

Testing for linkage under robust genetic models

Robust genetic models are used to assess linkage between a quantitative trait and genetic variation at a specific locus using allele-sharing data. Little is known about the relative performance of different possible significance tests under these models. Under the robust variance components model approach there are several alternatives: standard Wald and likelihood ratio tests, a quasilikelihood Wald test, and a Monte Carlo test. This paper reports on the relative performance (significance level and power) of the robust sibling pair test and the different alternatives under the robust variance components model. Simulations show that (1) for a fixed sample size of nuclear families, the variance components model approach is more powerful than the robust sibling pair approach; (2) when the number of nuclear families is at least approximately 100 and heritability at the trait locus is moderate to high (>0.20) all tests based on the variance components model are equally effective; (3) when the number of nuclear families is less than approximately 100 or heritability at the trait locus is low (<0. 20), on balance, the Monte Carlo test provides the best power and is the most valid. The different testing procedures are applied to determine which are able to detect the known association between low density lipoprotein cholesterol and the common genotypes at the locus encoding apolipoprotein E. Results from this application show that the robust sibling pair method may be more effective in practice than that indicated by simulations.

Germline mutations in the extracellular domains of the 55 kDa TNF receptor, TNFR1, define a family of dominantly inherited autoinflammatory syndromes

Autosomal dominant periodic fever syndromes are characterized by unexplained episodes of fever and severe localized inflammation. In seven affected families, we found six different missense mutations of the 55 kDa tumor necrosis factor receptor (TNFR1), five of which disrupt conserved extracellular disulfide bonds. Soluble plasma TNFR1 levels in patients were approximately half normal. Leukocytes bearing a C52F mutation showed increased membrane TNFR1 and reduced receptor cleavage following stimulation. We propose that the autoinflammatory phenotype results from impaired downregulation of membrane TNFR1 and diminished shedding of potentially antagonistic soluble receptor. TNFR1-associated periodic syndromes (TRAPS) establish an important class of mutations in TNF receptors. Detailed analysis of one such mutation suggests impaired cytokine receptor clearance as a novel mechanism of disease.

Murine dendritic cells transduced with an adenoviral vector expressing a defined tumor antigen can overcome anti-adenovirus neutralizing immunity and induce effective tumor regression

In this study transduced dendritic cells (DCs) were used to enhance immunogenecity of a specific tumor antigen. Using a polyoma middle T (PyMT) transgenic mammary carcinoma model we found that injections of DCs transduced with an adenoviral (Ad) vector expressing PyMT (DCAd-PymT) led to potent specific anti-tumor immunity. Efficacy was not affected by neutralizing Abs (high or low titers) and naive animals did not produce detectable anti-Ad Abs following two injections of transduced DCs. Repeated injections of transduced DCs significantly improved therapeutic efficacy in mice with established lung metastases. These data emphasize the ability of Ad-infected DCs to: i) minimize anti-Ad Ab production, ii) overcome pre-existing anti-Ad humoral immunity, and iii) improve vaccination efficacy when injected more than once.

Adenoviral vectors expressing lymphotactin and interleukin 2 or lymphotactin and interleukin 12 synergize to facilitate tumor regression in murine breast cancer models

We have previously demonstrated that intratumoral injection with Ad vectors expressing IL-2 or IL-12 can induce regression in a murine breast cancer model. These IL-2- or IL-12-induced antitumor responses were mainly mediated by Ag-specific T cells. Lymphotactin is a novel lymphocyte chemokine that can cause local accumulation of CD4+, CD8+, and NK cells. We hypothesized that addition of lymphotactin may enhance the antitumor immune responses induced by locally produced IL-2 and IL-12 as we have previously shown. To this end we constructed two double-recombinant adenoviral vectors expressing lymphotactin along with either IL-2 (Ad5 Lym/IL-2) or IL-12 (Ad5 Lym/IL-12). Subcutaneous injection of polyoma middle T (PyMT) or Neu (8142) transgenically derived breast adenocarcinoma cells, in the hind flank of FVB/n mice, results in the formation of tumor nodules in 14-21 days. We show that these constructs elicit potent antitumor responses when administered intratumorally. The antitumor responses are long lasting as determined by rechallenge experiments and hence demonstrate a protective immunity. These observations indicate that by augmenting the antitumor response with adenoviral vectors expressing lymphotactin in combination with IL-2 or IL-12 is a novel way to enhance immunotherapeutic approaches.

Adenovector-mediated gene delivery of interleukin-2 in metastatic breast cancer and melanoma: results of a phase 1 clinical trial

We conducted a phase 1 trial of direct injection of an E1, E3-deleted adenovirus encoding interleukin-2 (AdCAIL-2) into subcutaneous deposits of melanoma or breast cancer. Twenty-three patients were injected at seven dose levels (10(7)-10(10) p.f.u). Local inflammation was observed at the site of injection in 60% of patients, but side-effects were otherwise minor. Incomplete local tumor regression occurred at the site of injection in 24% of patients, but no conventional clinical responses were seen. Circulating CD4 and CD8 counts fell significantly 24 h after injection. Post-injection biopsies demonstrated tumor necrosis and lymphocytic infiltration with the predominant tumor-infiltrating cells both CD3- and CD8-positive. Vector-derived sequences were detected in 14 of 18 biopsies examined 7 days after injection and vector-derived hIL-2 mRNA was detected in 80% of 7-day biopsies processed after injection of 10(8) p.f.u. of AdCAIL-2 or higher. While IL-2 was detectable by ELISA in tumor biopsies at 48 h, no protein was detectable in injected tumors after 7 days and no circulating IL-2 was detectable at any time-point. No Ad5E1 sequences were detected either before or after injection indicating absence of replication-competent virus or endogenous E1-like sequence; furthermore, only rare vector shedding was detected. Anti-adenovirus and neutralizing antibody titers were elevated 1 month after injection in all patients. This trial therefore confirms the safety of use of adenoviral vectors for gene delivery in humans and demonstrates successful transgene expression even in the face of pre-existing immunity to adenovirus.

Phenotype, function, and in vivo migration and survival of allogeneic dendritic cell progenitors genetically engineered to express TGF-beta

BACKGROUND

Administration of donor bone marrow (BM)-derived dendritic cell (DC) progenitors (DCp) that are major histocompatibility complex (MHC) class II+ but costimulatory molecule (CD40, CD80, CD86)-deficient can prolong mouse heart allograft survival This is associated with microchimerism and inhibition of antidonor cytotoxic T lymphocyte (CTL) activity. Genetic modification of these donor antigen-presenting cells to express an immunosuppressive molecule(s) may enhance their in vivo survival and potential tolerogenicity.

METHODS

The surface phenotype of B10(H-2b) DCp before and after gene transfer using replication-deficient adenoviral (Ad) vectors was determined by monoclonal antibody (mAb) staining and flow cytometry. Transforming growth factor-beta (TGF-beta) production was quantitated by enzyme-linked immunosorbent assay. Allostimulatory activity of the gene-transduced DCp was ascertained by mixed leukocyte reaction (MLR) and CTL induction. To assess their in vivo migratory activity and survival, the transduced cells were injected subcutaneously into one hind footpad of C3H (H-2k) mice. Tissues (draining popliteal lymph nodes [LN], spleens, and thymi) were removed 1, 2, 7, and 14 days later and stained for donor MHC class II using anti-LA(b) mAb in an immunohistochemical procedure. The mean number of IAb+ cells per unit area was determined.

RESULTS

Transduction with a control Ad vector (Ad-LacZ) at 50 multiplicity of infection slightly increased CD40 and CD86 expression and up-regulated the poor allostimulatory activity of the DCp assessed by MLR and CTL responses. These effects on function were negated in Ad-TGF-beta1-transduced cells. After their injection into mouse footpads, the gene-transduced IAb+ cells were observed in maximal numbers in the popliteal LN at day 1 and in marginal zones and T-dependent areas of spleens (peak at day 7) but were rare in thymi. Transduction with Ad-LacZ reduced the numbers of IAb+ cells identified in both LN and spleens at all time points postinjection, suggesting that the vector alone affected DC life span in allogeneic recipients. TGF-beta1 transgene expression not only fully prevented the reduction in DC induced by Ad transduction alone, but also increased numbers and prolonged the survival of donor cells in the spleen, as shown by a two-to fivefold increase in IAb+ cells at days 2-14 compared with control (Ad-LacZ-transduced) DC.

CONCLUSION

BM-derived DCp can be transduced efficiently to express TGF-beta1 using an Ad vector. They exhibit very poor allostimulatory activity and similar migration characteristics in vivo to unmodified DCp. Survival of TGF-beta gene-transduced DC, however, is enhanced significantly compared with unmodified and (especially) control Ad-LacZ gene-transduced DC. Genetic engineering of donor DC to express the immunosuppressive molecule TGF-beta promotes their survival in allogeneic hosts and may potentiate their previously reported tolerogenicity.

[Clinical application of TMS-MEP in spinal cord injury]

OBJECTIVE

To evaluate transcranial magnetic stimulation motor evoked potential (TMS-MEP) in the diagnosis of spinal cord injury.

METHOD

56 patients with injury of the spinal cord and cauda equina were examined using TMS-MEP and followed up.

RESULT

In 21 patients with complete paralysis, TMS-MEP of bilateral tibialis anterior and gastrocnemius disappeared and paralysis did not recover. Abnormal was noted TMS-MEP and paralysis not recovered in 2 patients with injury of conus medullaris and cauda equina. Incomplete paralysis occurred in 35 patients. TMS-MEPs of more than one muscle in every patient were recorded. Paralysis and TMS-MEPs recovered in different degree in the 33 patients, in which the strength was 0 class and TMS-MEPs were abnormal in 25 target muscles before operation whereas their strength obviously recovered or even normalized after operation except two muscles.

CONCLUSION

TMS-MEP is an effective method for diagnosis and prognosis of spinal cord injury.

Enhanced interleukin-2 gene transfer immunotherapy of breast cancer by coexpression of B7-1 and B7-2

The capability of B7-1 to augment the antitumor activity of some cytokines has been shown primarily for such cytokines as interleukin-12 (IL-12), IL-7, and to a lesser extent IL-2. In this study, we investigate the ability of B7-1 and B7-2 to augment the antitumor activity of IL-2. Considering the affinity of both molecules for CD28 (T cell receptor for B7-1 and B7-2), we postulated that their potential to augment IL-2 antitumor activity would be similar. Two murine transgenic adenocarcinoma models were chosen to investigate the activity of adenoviral vectors constructed to express either B7-1 and IL-2 or B7-2 and IL-2. Before administering the vector intratumorally to tumor-bearing mice, we determined the expression of B7-1, B7-2, MHC I, and MHC II on these tumor cells and demonstrated positive expression of only MHC I. Intratumoral injection of the vector expressing B7-1 and IL-2 resulted in complete regression of all tumors treated. In contrast, the vector expressing B7-2 and IL-2 was significantly less effective at regressing PyMT tumors, whereas both double recombinant vectors demonstrated similar levels of complete regression in the Neu (NDL 8142) model. Regressed mice were all protected for rechallenge in both models and demonstrated antigen-specific cytotoxic T lymphocytes (CTL) in the PyMT model. These findings indicate that the combination of IL-2 with B7-1 or B7-2 significantly enhances the antitumor activity of IL-2.

Genetic linkage analysis using lognormal variance components

Typically genetic studies of continuous traits such as cholesterol levels or blood pressure assume that interindividual variability follows a normal distribution. Here we develop methods to analyze positively skewed data by assuming a lognormal distribution. We develop a variance components approach for identifying such effects from a major gene, residual polygenic factors and nongenetic factors. We compare by a simulation study results from fitting this lognormal model with either applying the log transformation or not transforming the data. We found that the lognormal model provided more precise estimates and more powerful tests than a simple log transformation when analyzing lognormally distributed data. Power varied with sibship size. For the same total number of nonindependent sibpairs, larger sibships were less powerful. However, larger sibships are more economical because they require a smaller sample size to obtain a specified power. To illustrate the application of this lognormal model to real data, we studied evidence for linkage between triglycerides and the lipoprotein lipase gene.

The G protein G alpha12 stimulates Bruton's tyrosine kinase and a rasGAP through a conserved PH/BM domain

Heterotrimeric guanine-nucleotide-binding proteins (G proteins) are signal transducers that relay messages from many receptors on the cell surface to modulate various cellular processes. The direct downstream effectors of G proteins consist of the signalling molecules that are activated by their physical interactions with a G alpha or Gbetagamma subunit. Effectors that interact directly with G alpha12 G proteins have yet to be identified. Here we show that G alpha12 binds directly to, and stimulates the activity of, Bruton's tyrosine kinase (Btk) and a Ras GTPase-activating protein, Gap1m, in vitro and in vivo. G alpha12 interacts with a conserved domain, composed of the pleckstrin-homology domain and the adjacent Btk motif, that is present in both Btk and Gap1m. Our results are, to our knowledge, the first to identify direct effectors for G alpha12 and to show that there is a direct link between heterotrimeric and monomeric G proteins.

Effect of estrogen on vascular smooth muscle cells is dependent upon cellular phenotype

To investigate the growth-regulating action of estrogen on vascular smooth muscle cells (SMC), effects of beta-17-estradiol (beta-E2) on phenotypic modulation and proliferation of rabbit aortic SMC were observed in vitro. At 10(-8)M, beta-E2 significantly slowed the decrease in volume fraction of myofilaments (Vv myo) of freshly dispersed SMCs in primary culture, indicating an inhibitory effect of beta-E2 on spontaneous phenotypic modulation of SMC from a contractile to a synthetic phenotype. Freshly dispersed SMCs treated with beta-E2 also had a relatively longer quiescent phase than control cells before intense proliferation occurred. This was in contrast to SMCs in passage 2 3 (synthetic state), where beta-E2-treated cells replicated significantly faster than untreated cells. beta-E2 also markedly enhanced the serum-induced DNA synthesis of synthetic SMCs in a concentration-dependent manner within physiological range (10(-10)to 10(-8)M). These findings indicate that the growth-regulating effect of estrogen on vascular SMC is dependent on the cell's phenotypic state. It delays the cell cycle re-entry of the contractile SMCs by retarding their phenotypic modulation: however, once cells have modulated to the synthetic phenotype, it promotes their replication.

Identification of a novel point mutation (Leu72Pro) in the NADH-cytochrome b5 reductase gene of a patient with hereditary methaemoglobinaemia type I

Utilizing polymerase chain reaction (PCR) related technology, we investigated the b5R gene of a Chinese patient with hereditary methaemoglobinaemia type I and found a novel missense mutation (CTC-CCC) at codon 72 in exon 3 of the gene. As the mutation generates an Apa I recognition site, homozygosity for the mutation was confirmed by restriction analysis of PCR-amplified fragments from the patient's genomic DNA. We predicted that the residue replacement of Leu with Pro of the mutant enzyme would account for the b5R deficiency in the patient. The results further confirm the genetic polymorphism of b5R gene mutations found in the RCM type I.

OFQ reverses the kappa-opioid receptor-mediated depression of calcium current in rat dorsal root ganglion neurons

Since the characterization of orphanin FQ (OFQ), the endogenous ligand of ORL1 receptor, much work has focused on its physiological functions. OFQ was reported to antagonize the effect of opioid-induced antinociception, although its mechanism remains obscure. In the present study, whole-cell patch clamp recording technique was used to observe if OFQ can reverse the inhibition of calcium current produced by the kappa-opioid agonist U50,488H (U50) in acutely dissociated rat DRG neurons. The concentrations of OFQ and U50 were 50 nM and 10 microM, respectively. Among 49 cells recorded, the calcium channel currents of 37 (75.5%) cells were inhibited by U50, of which 30 (81.1%) cells could be reversed by OFQ. It was interesting to note the similarity between OFQ and the well characterized anti-opioid peptide CCK-8 in that it reversed kappa-opioid receptor agonist induced suppression on calcium channel current, while by itself showed a calcium channel suppressive effect. Thus OFQ may be regarded as another anti-opioid peptide.

Analysis of the Gs/mitogen-activated protein kinase pathway in mutant S49 cells

Heterotrimeric G protein-coupled receptors can activate the mitogen-activated protein kinase (MAPK) cascade. Recent studies using pharmacological inhibitors or dominant-negative mutants of signaling molecules have advanced our understanding of the pathways from G protein-coupled receptors to MAPK. However, molecular genetic analysis of these pathways is inadequate in mammalian cells. Here, using the well characterized Gsalpha- and protein kinase A-deficient S49 mouse lymphoma cells, we provide the molecular genetic evidence that Gsalpha is responsible for transducing the beta-adrenergic receptor signal to MAPK in a protein kinase A-dependent pathway involving Rap1 and Raf (but not Ras) molecules.

[Anti-tumor effect of cytotoxic T lymphocytes induced by soluble antigen of ovarian carcinoma and anti-CD3 monoclonal antibody on ovarian carcinoma]

OBJECTIVE

To evaluate the therapeutic effect of the new method--adoptive cell immunotherapy on ovarian carcinoma.

METHODS

Tumor soluble antigen (TSA) was extracted from cells of ovarian carcinoma (COC1 and COC2n). To generate cytotoxic T lymphocytes (CTL), peripheral blood mononuclear cells (PBMC) collected from healthy persons were induced by TSA and anti-CD3 monoclonal antibody (CD3-McAb). The antitumor effect of CTL on COC1 cells in vitro was compared with LAK and CD3-AK, whereas the growth inhibitory effect of CTL on COC2n transplantation tumors in nude mice was compared with CD3-AK.

RESULTS

The cytotoxicity of CTL, CD3-AK and LAK was 79.4%, 52.1% and 51.7% respectively (P < 0.01). Mean volume of tumor in nude mice on the 9th day after ovarian carcinoma cells transplanted was 44.4 +/- 24.2 mm3 in CTL group, 118.8 +/- 40.0 mm3 in CD3-AK group and 443.0 +/- 158.7 mm3 in control (no treatment) (P < 0.01), whereas mean duration of survival was 28.5 days, 25.5 days and 17 days respectively (P < 0.01).

CONCLUSION

The results indicated that CTL exhibited higher cytotoxic effect in vitro and greater inhibitory effect on tumor growth resulting in longer survival in vivo. It suggested that the adoptive cell immunotherapy might provide a new idea for treatment of ovarian carcinoma.

Linkage of familial Hibernian fever to chromosome 12p13

Autosomal dominant periodic fevers are characterized by intermittent febrile attacks of unknown etiology and by recurrent abdominal pains. The biochemical and molecular bases of all autosomal dominant periodic fevers are unknown, and only familial Hibernian fever (FHF) has been described as a distinct clinical entity. FHF has been reported in three families-the original Irish-Scottish family and two Irish families with similar clinical features. We have undertaken a genomewide search in these families and report significant multipoint LOD scores between the disease and markers on chromosome 12p13. Cumulative multipoint linkage analyses indicate that an FHF gene is likely to be located in an 8-cM interval between D12S77 and D12S356, with a maximum LOD score (Z max) of 3.79. The two-point Z max was 3.11, for D12S77. There was no evidence of genetic heterogeneity in these three families; it is proposed that these markers should be tested in other families, of different background, that have autosomal dominant periodic fever, as a prelude to identification of the FHF-susceptibility gene.