Surveillance esophagogastroduodenoscopy using linked color imaging and narrow-band imaging: A multicenter randomized controlled trial

BACKGROUND AND AIM

There has been no report on a direct comparison between linked color imaging (LCI) and second-generation narrow-band imaging (2G-NBI) for surveillance of epithelial neoplasms in the upper gastrointestinal tract (UGIT). The aim of this study was to verify the superiority of LCI to 2G-NBI for surveillance esophagogastroduodenoscopy and to clarify how each endoscopic system should be used.

METHODS

This study was conducted as an open-label, two-arm-parallel (1:1), multicenter, randomized controlled trial at six institutions. Patients aged 20-85 years with a treatment history of epithelial neoplasms in the UGIT were recruited. Patients were assigned to a 2G-NBI group and an LCI group, and esophagogastroduodenoscopy was performed with primary image-enhanced endoscopy followed by white light imaging (WLI). The primary endpoint was the detection rate of one or more epithelial neoplasms in the primary image-enhanced endoscopy. A WLI-detected epithelial neoplasm was defined as a lesion that was detected in only WLI.

RESULTS

A total of 372 patients in the 2G-NBI group and 378 patients in the LCI group were analyzed. Epithelial neoplasms in the UGIT were detected by 2G-NBI in 18 patients (4.6%) and were detected by LCI in 20 patients (5.3%) (P = 0.87). WLI-detected epithelial neoplasms were in 11 patients in the 2G-NBI group (3.0%) and in 1 patient in the LCI group (0.27%) (P = 0.003).

CONCLUSIONS

Linked color imaging did not show superiority to 2G-NBI for the detection of epithelial neoplasms. Also, the percentage of WLI-detected epithelial neoplasms in primary NBI was significantly higher than that in primary LCI.

Background factors of idiopathic peptic ulcers and optimal treatment methods: a multicenter retrospective Japanese study

This study investigated the trends in idiopathic peptic ulcers, examined the characteristics of refractory idiopathic peptic ulcer, and identified the optimal treatment. The characteristics of 309 patients with idiopathic peptic ulcer were examined. We allocated idiopathic peptic ulcers that did not heal after 8 weeks' treatment (6 weeks for duodenal ulcers) to the refractory group and those that healed within this period to the healed group. The typical risk factors for idiopathic peptic ulcer (atherosclerosis-related underlying disease or liver cirrhosis complications) were absent in 46.6% of patients. Absence of gastric mucosal atrophy (refractory group: 51.4%, healed group: 28.4%; p = 0.016), and gastric fundic gland polyps (refractory group: 17.6%, healed group: 5.9%; p = 0.045) were significantly more common in the refractory group compared to the healed group. A history of H. pylori eradication (refractory group: 85.3%, healed group: 66.0%; p = 0.016), previous H. pylori infection (i.e., gastric mucosal atrophy or history of H. pylori eradication) (refractory group: 48.5%, healed group: 80.0%; p = 0.001), and potassium-competitive acid blocker treatment (refractory group: 28.6%, healed group, 64.1%; p = 0.001) were significantly more frequent in the healed group compared to the refractory group. Thus, acid hypersecretion may be a major factor underlying the refractoriness of idiopathic peptic ulcer.

Practice patterns, feasibility and efficacy of coronary artery angiography using distal radial approach

Background

Most patients undergo coronary angiography by transradial approach. However, recently distal radial approach has been introduced as a novel approach for coronary angiography and intervention. There is uncertainty on the feasibility and safety of distal radial approach for coronary angiography.

Methods

All consecutive 1450 coronary angiography cases (distal radial approach 237 cases, conventional transradial approach 1213 cases) between October 2018 and December 2019 were included in this study. Emergency coronary angiography cases and ad hoc coronary intervention cases were excluded. Patients were stratified into distal radial approach and conventional radial approach subgroups. Baseline characteristics, contrast amount, procedure time, radiation amount, fluoroscopy time, and complications in catheterization laboratory were statistically analyzed.

Results

There were no significant differences in age and gender between distal radial vs transradial groups: mean age, 70.8±10.5 vs 70.8±11.0 years; % of males, 77.2% vs 66.9%. Procedure time was significantly shorter in distal radial approach group (28.7±13.3 min vs 32.3±14.2 min, p<0.05) and total radiation amount during procedure was significantly less in distal radial approach group (366.4±189.5 ml vs 412.9±220.3 mGy, p<0.05).

Conclusions

Coronary angiography with distal radial approach decreases the procedure time and total radiation amount. It is feasible and safe in most stable patients.

Funding Acknowledgement

Type of funding source: None

Effectiveness of including probiotics to Helicobacter pylori eradication therapies

The eradication rate of Helicobacter pylori (H. pylori) with proton pump inhibitors, amoxicillin, and clarithromycin has reportedly decreased. Some studies have found probiotics to be useful in eradicating H. pylori, but these effects have not been sufficiently investigated. We aimed to elucidate the role of probiotics in eradicating H. pylori infection. Patients in our hospital with H. pylori infection that received standard treatment from January 2015 to December 2016 were retrospectively evaluated (n = 468). They were divided into three groups based on their treatment regime, being either proton pump inhibitors, amoxicillin, or clarithromycin (PPI group), vonoprazan, amoxicillin, or clarithromycin (VPZ group), and proton pump inhibitors, amoxicillin, or clarithromycin/probiotics (Miya-BM^®) (PPI + MBM group). We retrospectively evaluated the H. pylori eradication rate and reported side effects. According to intention-to-treat analyses, the eradication rate of H. pylori was significantly higher in the PPI + MBM group (87.1%) than in the PPI group (70.1%). There was no difference in side effects between any of the three groups. In conclusion, Miya-BM^® may have an additive effect when included with eradication therapies for H. pylori.

High-Fat Diet Causes Constipation in Mice via Decreasing Colonic Mucus

BACKGROUND

Constipation is one of the most common gastrointestinal complaints. Although the causes of constipation are varied, dietary habits have a significant influence. Excessive fat intake is suggested as one of the main causes of constipation; however, the exact mechanism is unknown.

AIMS

To investigate whether a high-fat diet (HFD) causes constipation in mice and to clarify the underlying mechanism, focusing on the amount of colonic mucus.

METHODS

Six-week-old male C57BL/6 mice were randomly divided into two groups: mice fed with HFD and those with normal chow diet (NCD). Fecal weight, water content, total gastrointestinal transit time, and colon transit time were measured to determine whether the mice were constipated. The colonic mucus was evaluated by immunostaining and quantified by spectrometry. Malondialdehyde (MDA) was measured using the thiobarbituric acid (TBA) test as a marker for oxidative stress.

RESULTS

Compared to the NCD group, the weight of feces was less in the HFD group. In the functional experiment, the total gastrointestinal transit time and colon transit time were longer in the HFD group. Furthermore, HFD significantly reduced the amount of colonic mucus. In addition, the reduction in colonic mucus caused by surfactant resulted in constipation in the NCD group.

CONCLUSIONS

HFD causes constipation with delayed colon transit time possibly via the reduction in colonic mucus in mice.

Effectiveness of including probiotics to Helicobacter pylori eradication therapies

The eradication rate of Helicobacter pylori (H. pylori) with proton pump inhibitors, amoxicillin, and clarithromycin has reportedly decreased. Some studies have found probiotics to be useful in eradicating H. pylori, but these effects have not been sufficiently investigated. We aimed to elucidate the role of probiotics in eradicating H. pylori infection. Patients in our hospital with H. pylori infection that received standard treatment from January 2015 to December 2016 were retrospectively evaluated (n = 468). They were divided into three groups based on their treatment regime, being either proton pump inhibitors, amoxicillin, or clarithromycin (PPI group), vonoprazan, amoxicillin, or clarithromycin (VPZ group), and proton pump inhibitors, amoxicillin, or clarithromycin/probiotics (Miya-BM^®) (PPI + MBM group). We retrospectively evaluated the H. pylori eradication rate and reported side effects. According to intention-to-treat analyses, the eradication rate of H. pylori was significantly higher in the PPI + MBM group (87.1%) than in the PPI group (70.1%). There was no difference in side effects between any of the three groups. In conclusion, Miya-BM^® may have an additive effect when included with eradication therapies for H. pylori.

Transforming growth factor β1-induced collagen production in myofibroblasts is mediated by reactive oxygen species derived from NADPH oxidase 4

Intestinal fibrosis with stricture formation is a severe complication of Crohn's disease (CD). Though new therapeutic targets to enable the prevention or treatment of intestinal fibrosis are needed, markers of this condition and the basic mechanisms responsible have not been established. NADPH oxidase (NOX) 4 has already been reported to play a key role in models of fibrogenesis, including that of the lung. However, its importance in intestinal fibrogenesis remains unclear. In this study, we examined the role of NOX4 in collagen production by intestinal myofibroblasts stimulated with transforming growth factor (TGF)-β1. Using LmcMF cells, an intestinal subepithelial myofibroblast (ISEMF) line, we first examined the induction of collagen production by TGF-β1. Subsequently, we investigated the role of NOX4 in TGF-β1-induced collagen I production in these cells using SB525334 (an SMAD2/3 inhibitor), diphenyleneiodonium (an NOX inhibitor), and Nox4 small interfering RNA (siRNA). Production of collagen was assessed with Sirius red staining, and Nox4 expression was measured by quantitative real-time PCR. Reactive oxygen species (ROS) production was determined using DCFDA and fluorescent microscopy. We observed that TGF-β1 induced collagen production via NOX4 activation and ROS generation in LmcMF cells. Nox4 siRNA and inhibitors of TGF-β1 receptor and NOX significantly reduced TGF-β1-induced ROS and collagen production. Thus, in the present study, we revealed that collagen production in ISEMFs is induced via an NOX4-dependent pathway. This work supports a function for NOX4 in intestinal fibrogenesis and identifies it as a potential therapeutic target in recalcitrant fibrotic disorders of CD patients.

Ir(iii) complex-based oxygen imaging of living cells and ocular fundus with a gated ICCD camera

Phosphorescence lifetime imaging methods using oxygen-sensitive probes are very useful for visualizing the oxygen status of living cells and tissues with high spatial resolution. We aim to develop a useful oxygen detection technique combining a phosphorescent oxygen probe and an optimal detection method. Herein we present a biological oxygen imaging method using a microscope equipped with a gated intensified charge-coupled device (ICCD) camera as a detector and an Ir(iii) complex as a phosphorescent oxygen probe. Microscopic luminescence images of monolayer HT-29 cells (human colorectal adenocarcinoma cells) obtained using the cell-penetrating Ir(iii) complex BTPDM1 and an inverted microscope demonstrated that this method allowed visualization of the oxygen gradient produced in a monolayer of cultured cells when the monolayer is covered with a thin coverslip. Furthermore, combining the IR-emitting Ir(iii) complex DTTPH-PEG24 with a macrozoom microscope equipped with a gated ICCD camera enabled both the visualization of retinal vessels near the optic disc and the monitoring of oxygen level changes in a rabbit retina upon changing the inhaled oxygen content.

Formation of modulated phases and domain rigidification in fatty acid-containing lipid membranes

We investigated the phase behavior of lipid membranes containing fatty acids (FAs) by microscopy and differential scanning calorimetry. We used palmitic acid (saturated FA), oleic acid (cis-isomer of unsaturated FA), elaidic acid (trans-isomer of unsaturated FA), and phytanic acid (branched FA) and examined the effects of FAs on phase-separated structures in lipid bilayer membranes consisting of dioleolylphosphocholine (DOPC)/dipalmitoylphosphocholine (DPPC)/cholesterol (Chol). Palmitic acid and elaidic acid exclude Chol from the DPPC-rich phase. As a result, the liquid-ordered phase formed by DPPC and Chol transforms into a solid-ordered phase. Oleic acid and phytanic acid significantly reduce the line tension at the liquid domain boundary. This decrease in line tension leads to the formation of modulated phases, such as striped, hexagonal, and polygonal domains. We measured the line tension and the interdomain interaction in these specific domains by an image analysis. The result showed that oleic acid and phytanic acid-containing vesicles as well as palmitic acid-containing vesicles are not spherical, and this domain-induced deformation is explained theoretically.

[A case of gastrointestinal amyloidosis and hypoproteinemia improved by tocilizumab]

A woman in her 70s presented with dehydration and malnutrition due to watery diarrhea. She was examined and diagnosed with gastrointestinal amyloidosis accompanied by a protein-losing gastroenteropathy secondary to rheumatoid arthritis. She first underwent treatment with an anti-tumor necrosis factor alpha (TNF-α) antibody for secondary amyloidosis, but due to lack of adequate response, she was switched to an anti-interleukin (IL)-6 receptor antibody. Her clinical symptoms subsequently improved, and endoscopy revealed a marked decrease of amyloid protein deposits in the digestive tract. She was followed up for 3 years while continuing to receive the anti-IL-6 receptor antibody, with no recurrence. Although secondary amyloidosis is a fatal disease associated with chronic inflammatory diseases, clinical symptoms and prognosis have recently been improved by intervention with biological therapies. In particular, anti-IL-6 receptor antibodies have been reported to be superior to anti-TNF-α antibodies in the treatment of secondary amyloidosis and are expected to play a central role in treating secondary amyloidosis in the future.

Near-infrared absorbing polymer nano-particle as a sensitive contrast agent for photo-acoustic imaging

Polymer nano-particles (PNPs) with a near-infrared (NIR) light absorption were prepared by the nano-emulsion method to develop contrast agents for photo-acoustic (PA) imaging. The PNP containing silicon naphthalocyanine showed a high absorption coefficient up to 10(10) M(-1) cm(-1). This is comparable to plasmonic gold nano-particles, which have been studied as PA contrast agents. For the PNP larger than 100 nm, the enhancement of the PA signal was observed compared to the gold nano-particle with a similar absorption coefficient and size. In the case of the PNP, the heat by the light absorption is confined in the particle due to the low thermal diffusivity of polymer materials. We showed that the strong thermal confinement effect of PNP results in the enhancement of the efficiency of the PA signal generation and that the PA intensity can be enhanced by the increase of the Grüneisen parameter of the matrix polymer of PNP. The PA signal from the PNP of poly(methyl methacrylate) was 9-fold larger than that of gold nano-particles with the same absorption coefficient. We demonstrated that in the in vivo PA imaging the detection limit of PNP was of the order of 10(-13) M. The NIR absorbing PNP will be a promising candidate of a sensitive contrast agent for PA imaging.

HTLV-1 HBZ positively regulates the mTOR signaling pathway via inhibition of GADD34 activity in the cytoplasm

Human T-cell leukemia virus type-1 (HTLV-1) infection causes adult T-cell leukemia (ATL). Modulation of the transcriptional control of cellular genes by HTLV-1 is thought to be associated with the development of ATL. The viral protein HTLV-1 basic leucine-zipper factor (HBZ) has been shown to dysregulate the activity of cellular transcription factors. Here, we demonstrate that HBZ is exported from the nucleus to the cytoplasm, where it activates the mammalian target of rapamycin (mTOR) signaling pathway through an association with growth arrest and DNA damage gene 34 (GADD34). The N-terminal region of HBZ interacts with the C-terminal region of GADD34. HBZ contains a functional nuclear export signal (NES) sequence within its N-terminal region and it is exported from the nucleus via the CRM1-dependent pathway. Nuclear export of HBZ is essential for its interaction with GADD34 and increased phosphorylation of S6 kinase, which is an established downstream target of the mTOR pathway. Starvation-induced autophagy is significantly suppressed by the overexpression of HBZ. These findings indicate that HBZ is actively exported to the cytoplasm, where it dysregulates the function of cellular factors.

Adaptive acquisition and tracking for deep space array feed antennas

The use of radial basis function (RBF) networks and least squares algorithms for acquisition and fine tracking of NASA's 70-m-deep space network antennas is described and evaluated. We demonstrate that such a network, trained using the computationally efficient orthogonal least squares algorithm and working in conjunction with an array feed compensation system, can point a 70-m-deep space antenna with root mean square (rms) errors of 0.1-0.5 millidegrees (mdeg) under a wide range of signal-to-noise ratios and antenna elevations. This pointing accuracy is significantly better than the 0.8 mdeg benchmark for communications at Ka-band frequencies (32 GHz). Continuous adaptation strategies for the RBF network were also implemented to compensate for antenna aging, thermal gradients, and other factors leading to time-varying changes in the antenna structure, resulting in dramatic improvements in system performance. The systems described here are currently in testing phases at NASA's Goldstone Deep Space Network (DSN) and were evaluated using Ka-band telemetry from the Cassini spacecraft.

Identification of an amino acid responsible for the CD3 polymorphism in cynomolgus monkeys (Macaca fascicularis)

The FN18 monoclonal antibody (mAb), directed to CD3 molecules, did not react with the lymphocytes of some cynomolgus monkeys (Macaca fascicularis), because of the polymorphism of the CD3epsilon chain. The epitope recognized by the FN18 mAb was successfully expressed on COS7 cells upon transfection of plasmid DNA coding for the CD3epsilon derived from T cells of a FN18 positive cynomolgus monkey. By construction and expression of plasmid DNA encoding the mutant CD3epsilon, the amino acid residue at position 67 was demonstrated to be involved in the formation of an epitope recognizable by the FN18 mAb.

Detection of B virus antibody in monkey sera using glycoprotein D expressed in mammalian cells

The gene encoding glycoprotein D (gD) of the monkey B virus (Cercopithecine herpesvirus 1) was cloned into a mammalian expression vector, pcDNA3.1(-), and the recombinant plasmid DNA was transfected into COS7 cells. The expression of gD in transfected COS7 cells was detected by indirect immunofluorescence assay or radioimmunoprecipitation analysis (RIPA). Although the expressed gD protein was revealed to react well with sera from monkeys naturally infected with B virus by RIPA, some sera showed reduced reactivity when analyzed by the Western blotting (WB) method. Some sera also showed relatively high background when the WB was performed using gD expressed from recombinant plasmid. The mutant gD protein lacking the transmembrane domain (TM) and cytoplasmic tail (CT) was next expressed in COS7 cells. The mutant protein was secreted into culture medium without apparent loss of the antigenicity. Using the secretory form of the gD protein as antigen in dot blot analysis, sera from B virus-infected monkeys were shown to react with the mutant protein without nonspecific reaction. Since the recombinant gD or its derivative lacking TM and CT could be expressed in mammalian cells with proper antigenicity, these antigens appeared to be useful for serological detection of B virus infection in monkeys.

Evidence as a HIV-1 self-defense vaccine of cyclic chimeric dodecapeptide warped from undecapeptidyl arch of extracellular loop 2 in both CCR5 and CXCR4

Novel conformation-specific antibodies were raised against a cyclic chimeric dodecapeptidyl multiple antigen peptide (cCD-MAP) constructed with a spacer-armed Gly-Asp dipeptide and two pentapeptides (S(169)-Q(170)-K(171)-E(172)-G(173) of CCR5 and E(179)-A(180)-D(181)-D(182)-R(183) of CXCR4) which are components of the undecapeptidyl arch (UPA: from R(168) to C(178) in CCR5, from N(176) to C(186) in CXCR4) of extracellular loop 2 (ECL2) in chemokine receptors (CCR5 and CXCR4). Of the antibodies raised, one monoclonal antibody, CPMAb-I (IgMkappa), reacted with cCD-MAP, but not with the linear chimeric dodecapeptide-MAP. The antibody reacted with the cells separately expressing CCR5 or CXCR4, but not with those not expressing the coreceptors. Moreover, the antibody markedly suppressed infection by X4, R5, or R5X4 virus in a dose-dependent manner in a new phenotypic assay for drug susceptibility of HIV-1 using CCR5-expressing Hela/CD4(+) cell clone 1-10 (MAGIC-5). Moreover, CPMAb-I interfered with LAV-1(BRU) infection (m.o.i. = 0.01) of Molt4#8 cells cocultured with CPMAb-I-producing hybridoma in the transwell, and significantly interfered with neither chemotaxis nor calcium influx induced with stromal cell-derived factor 1 alpha (SDF-1alpha). Thus, the antibody raised against the cCD-MAP provides powerful protection or defense against HIV-1 infection. We therefore propose the cCD-MAP or its derivative immunogen as a novel candidate for an HIV-1 coreceptor-based self-defense vaccine.

Detection of B virus infection in cynomolgus monkeys by ELISA using simian agent 8 as alternative antigen

The use of simian agent 8 (SA8) as an antigen for B virus (BV) antibody detection was evaluated in cynomolgus monkeys. Seventy-two sera judged as positive using BV antigen were all positive when the SA8 antigen was used. Out of 28 BV-negative sera 2 were positive against the SA8 antigen and one serum was classified as indeterminate. The present data indicates that detection of BV antibody can be achieved accurately and safely by enzyme-linked immunosorbent assay (ELISA) using SA8 antigen.

CD3 polymorphism in cynomolgus monkeys (Macaca fascicularis)

Cynomolgus monkeys were divided into two groups in terms of the reactivity of their lymphocytes with the FN18 monoclonal antibody, which is directed to the CD3 of rhesus monkeys. It was shown that 24 (12.2%) out of 196 monkeys did not have lymphocytes that reacted with the FN18, although T cells from those animals responded well to mitogenic stimulation. We have determined the nucleotide sequences of the CD3delta, CD3gamma, and CD3epsilon chains and found that two amino acids of the CD3epsilon chain of the FN18 non-reactive monkeys were different when compared with the FN18 reactive monkeys. Our results indicated that the CD3epsilon molecule of cynomolgus monkeys is polymorphic at the epitope level, which is recognized by the FN18 monoclonal antibody.

Sequence and functional properties of African green monkey CD4 silencer

We reported previously that in African green monkey (AGM) CD4 lymphocytes, CD4 mRNA expression undergoes a decrease following in vitro activation, and CD4 cells are therefore subject to loss of CD4 expression on the cell surface. To examine the transcriptional regulation of the CD4 gene in this species. we analyzed the CD4 silencer, which has been identified as a regulatory element responsible for the down regulation of CD4 transcription in CD8 cell lineage cells. Sequence analysis indicated that the CD4 silencer of the AGM was highly homologous to that of humans. However, two nucleotide substitutions were present in one of the nuclear protein binding sites, which was characterized as the FP II site having a strong enhancing effect on transgene expression in CD4 cells. By performing transient transfection assays. we found that the enhancing activities of the CD4 silencer or FP II-containing fragment of the AGM were greatly reduced in a human CD4 cell line as compared to those of human materials. The CD4 mRNA level was significantly decreased in the human CD4 cell line when synthetic oligonucleotide corresponding to the human FP II sequence was added to the culture. These observations imply that FP II-protein interaction might be required for the maintenance of sufficient expression of the CD4 gene, and the enhancing activity mediated by the above interaction might be decreased in the AGM CD4 silencer, due probably to the nucleotide changes occurring at the FP II site.

Rapid discrimination of monkey B virus from human herpes simplex viruses by PCR in the presence of betaine

A PCR method to amplify DNA segments of the glycoprotein G gene of monkey B virus (BV) was achieved by adding betaine to the PCR mixture, in spite of the high G+C content of this gene. No product was obtained when DNA of human herpes simplex viruses (HSVs) was used as the template under the same conditions. Thus, this PCR method is useful in discriminating BV from HSVs.

A putative G protein-coupled receptor, RDC1, is a novel coreceptor for human and simian immunodeficiency viruses

More than 10 G protein-coupled receptors (GPCRs) have been shown to act as coreceptors for infection of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We have isolated HIV-1 variants infectious to primary brain-derived CD4-positive cells (BT-3 and BT-20/N) and U87/CD4 glioma cells that are resistant to T-cell line-tropic (T-tropic), macrophage-tropic (M-tropic), and T- and M-tropic (dualtropic) (X4, R5, and R5X4) HIV-1 strains. These primary brain-derived cells were also highly susceptible to HIV-2(ROD), HIV-2(SBL6669), and SIV(mndGB-1). A factor or coreceptor that determines the susceptibility of these brain-derived cells to these HIV and SIV strains has not been fully identified. To identify this coreceptor, we examined amino acid sequences of all known HIV and SIV coreceptors and noticed that tyrosine residues are well conserved in their extracellular amino-terminal domains. By this criterion, we selected 18 GPCRs as candidates of coreceptors for HIV and SIV strains infectious to these brain-derived cells. mRNA expression of an orphan GPCR, RDC1, was detected in the brain-derived cells, the C8166 T-cell line, and peripheral blood lymphocytes, all of which are susceptible to HIV-1 variants, but not in macrophages, which are resistant to them. When a CD4-expressing cell line, NP-2/CD4, which shows strict resistance to infection not only with HIV-1 but also with HIV-2 or SIV, was transduced with the RDC1 gene, the cells became highly susceptible to HIV-2 and SIV(mnd) strains but to neither M- nor T-tropic HIV-1 strains. The cells also acquired a low susceptibility to the HIV-1 variants. These findings indicate that RDC1 is a novel coreceptor for several HIV-1, HIV-2, and SIV strains which infect brain-derived cells.

An African green monkey lacking peripheral CD4 lymphocytes that retains helper T cell activity and coexists with SIVagm

Natural infection with simian immunodeficiency virus (SIV) is known to occur in the African green monkey (AGM). The actual onset of the disease has not been recognized in SIVagm infected AGM, and the precise reason for such apathogenicity in the AGM remains unclear. We reported previously that AGM peripheral CD4 lymphocytes underwent a peculiar differentiation from CD4+ to CD4- cells after in vitro activation, and we inferred that the AGM does not fall into a fatal immunodeficient state because of the generation of CD4- helper T cells in vivo. To evaluate this possibility, we examined the relationship between CD4 expression and helper T cell activity in the naturally infected AGM. We identified a healthy monkey almost lacking CD4 T cells in the periphery. This AGM showed no signs and symptoms of immunodeficiency and retained a helper T cell activity in antibody production comparable to those of CD4+ AGMs. In addition, SIVagm could be isolated from CD8+ lymphocytes in the CD4- AGM. These observations suggest that a unique host-virus adaptation has developed in the AGM, and may be helpful in explaining the fundamental reason for the apathogenicity occurring in this monkey.

An allosteric drug, o,o'-bismyristoyl thiamine disulfide, suppresses HIV-1 replication through prevention of nuclear translocation of both HIV-1 Tat and NF-kappa B

The efficacy of o,o'-bismyristoyl thiamine disulfide (BMT) was examined in detail against HIV-1 laboratory isolates (HTLV-IIIB, JRFL, and MN), primary isolates (KMT and KMO), and simian immunodeficiency virus (SIVmac251) in vitro. BMT inhibited the replication of HIV-1 in both laboratory and primary isolates in vitro. In addition, BMT exhibited antiviral activity against SIVmac251. Minimizing energy studies of BMT structure reveal that a trans-disulfide of thiamine (holo drug) disulfide (TDS, protodrug) is allosterically transited to the reactive twisted disulfide of BMT (allo drug) by o,o'-bismyristoyl esterification of TDS. BMT inhibits nuclear translocation of both HIV-1 transactivator (TAT) and the cellular transcriptional nuclear factor-KB (NF-kappa B), resulting in the suppression of HIV-1 replication.

Biological behaviour of 6-chloro-2',3'-dideoxyguanosine and 6-chloro-2',3'-dideoxyinosine in the brains of mice

By using tissue and blood from mice and mice themselves, biological behavior of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) and 6-chloro-2',3'-dideoxyinosine (6-Cl-ddI) was examined in vitro and in vivo. Both compounds resemble each other in chemical structure. They are converted to ddG and ddI, respectively, by adenosine deaminase in the cells, and express their anti-HIV activity in vitro. According to our recent data about their biological behaviour in vivo; however, it was revealed that they are fairly different especially as the agent working in the brain. After injection of each drug into the body of mice, ddG, or metabolite of 6-Cl-ddG, was observed in the brain, while ddI was not found there.

Simian T cell leukemia virus type I-induced malignant adult T cell leukemia-like disease in a naturally infected African green monkey: implication of CD8+ T cell leukemia

Spontaneous T cell leukemia was found in an African green monkey (Cercopithecus aethiops, AGM) naturally infected with simian T cell leukemia virus type I (STLV-I). The hematological features and the evidence for monoclonal integration of provirus DNA in the leukemic cells revealed that the leukemia was an ATL-like disease. The expression of surface markers on the leukemic cells indicated that they were defined as an activated CD8+ T cell subset. Together with the finding that seven in vitro spontaneously STLV-I-transformed cell lines were CD4-CD8+, it is likely that CD8+ T cells are transformed by STLV-I in AGMs, in contrast with human ATL. Finally, we assessed characteristics of the CD8 chains on these transformed cells. The result indicated that the leukemic cells expressed only the alpha chains but not the beta chains. However, in the case of in vitro-transformed cell lines the expression pattern of the CD8 chains varied in individual monkeys. Thus, STLV-I may preferentially transform CD8+ (both alphaalpha+ and alphabeta+) T cells in AGMs.

Antiviral effects of 6-chloro-2',3'-dideoxyguanosine in rhesus monkeys acutely infected with simian immunodeficiency virus

A lipophilic dideoxynucleoside analogue, 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), was expected to be effective against AIDS-related dementia. In this study, we tested the effect of 6-Cl-ddG on simian immunodeficiency virus (SIVmac239) replication in vitro and on acute infection of six rhesus monkeys (Macaca mulatta) with SIVmac239. This compound inhibited SIV-induced cytopathic effect in CEM x 174 cells and SIV replication in vitro with an ED50 value of 2.5 microM. A dose of 25 mg/kg 6-Cl-ddG was administered to three monkeys every 8 h for 10 days and an untreated group of three monkeys was injected with the solvent without drug. Although 6-Cl-ddG was not detected in the plasma, the metabolite ddG was maintained at a concentration of more than 3 microM for 8 h after administration. In the cerebrospinal fluid, the ddG concentration was 2 microM at 2 h after administration. SIV antigen (p27) and antibody appearance in the plasma were delayed for 5-8 days compared with the mock-treated group. The occurrence of lymphadenopathy in treated monkeys was delayed for 6 days compared with the mock-treated group. Signs of 6-Cl-ddG toxicity were minimal after the treatment. The results of this study provide further evidence that 6-Cl-ddG may act as a potent anti-human immunodeficiency virus agent in vivo.

Efficacy of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) on rhesus macaque monkeys chronically infected with simian immunodeficiency virus (SIVmac239)

To assess the therapeutic effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), a lipophilic dideoxynucleoside analogue, three rhesus macaques chronically infected with simian immunodeficiency virus (SIVmac239) were subcutaneously administered 25 mg/kg of the drug every 8 hours for 2 weeks. In two of three animals, the viral RNA in plasma and the cell-associated viral load from peripheral blood mononuclear cells were markedly decreased and the number of CD4+ and CD8+ lymphocytes were increased after 6-Cl-ddG administration. The decrease of the virus copies was associated with a reciprocal increase in the number of CD4+ lymphocytes. Additionally, a limiting dilution assay revealed a marked decrease in the lymph node cell-associated virus titer during the treatment. However, in the third monkey, the baseline of the number of CD4+ and CD8+ lymphocytes was higher than that of the other monkeys; these numbers changed very little during the treatment. In this monkey, the plasma SIV RNA level was decreased at the first week and was the same as the pretreatment level at the second week of the 6-Cl-ddG administration. In all three treated monkeys, the number of SIV RNA copies in the cerebrospinal fluid also tended to decrease during the 6-Cl-ddG treatment.

Effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIVmac239)

We studied the effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), an antiretroviral drug, in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIV). The rhesus monkeys were treated with 25 mg/kg of 6-Cl-ddG every 8 hr for 2 weeks. We performed sequential biopsies of the surface lymph nodes three times: before, during, and after the drug treatment. The 6-Cl-ddG dramatically decreased the number of infectious virus (measured by limiting dilution assay) in lymph node mononuclear cells. This decrease was consistent with the decrease in the number of viral RNA-positive cells in lymph nodes (analyzed by in situ hybridization). Histopathological analysis revealed that hyperplastic lymphoid follicles were reduced in size, especially, enlarged areas of centroblasts in lymphoid follicles (the so-called dark areas of germinal centers) were declined. Our results demonstrated that 6-Cl-ddG decreased the viral burden concomitantly with reduced hyper-activation of germinal centers in lymphoid follicles of SIV-infected rhesus monkeys.

CD4 and CD8 expressions in African green monkey helper T lymphocytes: implication for resistance to SIV infection

We found that most peripheral CD4 cells co-express a low density of CD8 alpha antigen in African green monkeys (AGM). Further, the cell surface expression of CD4 and the expression of CD4 mRNA underwent a decrease when purified CD4CD8low cells were cultured with mitogen and IL-2. These observations suggest that AGM CD4 cells are subject to loss of CD4 expression after lymphocyte activation. Part of the peripheral CD8 fraction exhibited a significant helper activity which suggested the phenotypic conversion in helper T cells from CD4+ to CD4- in vivo. Simian immunodeficiency virus (SIV) grew well in CD4 panning cells following SIV infection. In contrast, CD4CD8low cells were resistant to SIV infection after their conversion to CD4- cells.

Protection of monkeys vaccinated with vpr- and/or nef-defective simian immunodeficiency virus strain mac/human immunodeficiency virus type 1 chimeric viruses: a potential candidate live-attenuated human AIDS vaccine

Two simian immunodeficiency virus strain mac (SIVmac)/human immunodeficiency virus type 1(HIV-1) chimeric viruses (SHIVs), designated NM-3 and NM-3n, with env derived from HIV-1 and defective vpr (plus defective nef for NM-3), were inoculated into seven macaques. These macaques were transiently or persistently infected and most of them produced long-lasting neutralizing antibodies and Env-specific killer T cells to HIV-1 with no AIDS-like symptoms. When they were challenged with another SHIV with intact vpr and nef (designated NM-3rN), all were protected as judged by virus recovery, DNA detection by PCR and antibody responses. Anti-HIV-1 Env-specific killer T cells were considered to have played a major role in this protection, but a non-specific defence mechanism as well as specific immunity also appeared to be involved. Thus, these two non-pathogenic SHIVs induced long-lasting protective immunities in macaques, suggesting the possibility of gene-defective SHIVs as attenuated live vaccines for human use.

Efficacy of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) on an ARC/AIDS rhesus macaque (Macaca mulatta) infected with simian immunodeficiency virus

The efficacy of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) was investigated in vivo by using a male ARC/AIDS rhesus macaque infected with simian immunodeficiency virus (SIVmac251/32H). He was administered subcutaneously 6-Cl-ddG (50 mg/kg B.W.) every 8 hr for 14 days when he showed clinical features of recurrent weight loss, severe diarrhea and neuropathy. The number of CD4+, CD8+ cells and total T cells increased rapidly after administration of 6-Cl-ddG and a high level was maintained for 2 months, but the B cell count decreased during the treatment. The antibody titer to SIV did not change significantly during or after the treatment, but the virus load in the plasma measured by RT-PCR dropped to one-third at the start of the 6-Cl-ddG treatment. Within 3 days after the start of 6-Cl-ddG administration, he began to show recovery in clinical signs including weight increase, and disappearance of diarrhea and neuropathy. These findings suggested that 6-Cl-ddG was effective at the stage of ARC/AIDS in a rhesus monkey infected with SIV.

Genomic and biological alteration of a human immunodeficiency virus type 1 (HIV-1)-simian immunodeficiency virus strain mac chimera, with HIV-1 Env, recovered from a long-term carrier monkey

A macaque monkey infected with NM-3, a human immunodeficiency virus type 1 (HIV-1)-simian immunodeficiency virus strain mac (SIVmac) chimeric virus with env, rev, tat and vpu derived from HIV-1 and LTR, gag, pol, vif and vpx derived from SIVmac, became a long-term carrier (more than 2.8 years). This monkey produced neutralizing antibodies to the original NM-3 as well as to the parental HIV-1. The virus recovered at 116 weeks replicated more rapidly and productively in macaque peripheral blood mononuclear cells than the original virus. The recovered virus was not neutralized either by antibodies raised early in the monkey or by a neutralizing monoclonal antibody that recognizes the V3 loop of HIV-1 Env, whereas both the early antibodies and the monoclonal antibody neutralized the original NM-3. Analysis of the virus genomic population revealed a few common mutations in the V3 region that caused amino acid changes. These data are consistent with the hypothesis that the virus escaped from the early antibodies and that the observed mutations contributed to this, as with HIV-1-infected humans. The observed mutations could equally well be the result of adaptation to simian cells. These results suggest that the HIV-1-SIVmac chimeric virus will be useful for investigating genetic variation of HIV-1 env and alteration of biological properties in vivo in relation to the host immune response.

Transient expression of CD20 antigen (pan B cell marker) in activated lymph node T cells

In contrast to the case of peripheral T cells, the surface expression of CD20 antigen and the expression of CD20 mRNA in monkey lymph node (LN) T cells underwent a noticeable increase when they were cultured with mitogen and interleukin-2 (IL-2). To confirm in vivo regulation of CD20 expression during the activation of LN T cells, we examined LNs derived from monkeys experimentally inoculated with simian immunodeficiency virus (SIV). Significant expression of CD20 antigen was detected in the T cells of the LNs at the stage of lymphadenopathy. These findings suggest that lymphocyte activation in the LNs induced expression of the CD20 molecule in some T cells.

In vitro immortalization of Old World monkey T lymphocytes with Herpesvirus saimiri: its susceptibility to infection with simian immunodeficiency viruses

Peripheral blood T lymphocytes of Old World monkeys, rhesus and cynomolgus monkey (Macaca mulatta and Macaca fascicularis, respectively), were successfully immortalized by infection with Herpesvirus saimiri subtype C. The T cell lines were stably cultured without addition of exogenous IL-2. The STP-C488 protein, the oncogene product of subtype C strain 488-77, was detected in these cells by Western blotting. They also expressed some markers of activated or matured T cell phenotypes such as CD2+, monkey Pan-T+, CD25+,CD29+ and MHC-II DR+. Interestingly, not only CD4+CD8- or CD4-CD8+ single positive subpopulations but also CD4+CD8+ double positive ones were present in all of them. Furthermore, they were productively infected with both SIVmac and SIVagm. The levels of the viral replication were comparable to those in human T cell lines. Thus, Herpes Virus Saimiri-immortalized Old World monkey T lymphocytes will be suitable for further studies of immune system in Old World monkeys and cell-virus interactions in SIV infection.

Severe pulmonary pneumocystosis in simian acquired immunodeficiency syndrome induced by simian immunodeficiency virus: its characterization by the polymerase-chain-reaction method and failure of experimental transmission to immunodeficient animals

Pneumocystis carinii (Pc) infection was observed in three of five rhesus monkeys infected with simian immunodeficiency virus (SIVmac251). They showed severe symptoms similar to those associated with human acquired immunodeficiency syndrome (AIDS). Histopathology revealed severe pulmonary pneumocystosis in one of three Pc-positive monkeys, and anti-Pc antibodies were detected in sera from two of the three monkeys. Localization of Pc organisms in various organs of the monkeys was examined by the polymerase-chain-reaction (PCR) method, and Pc-specific bands of DNA amplification were detected in the liver, kidney, spleen, adrenal gland, testis, brain, and other organs examined, but no Pc organism was found in these organs by histopathologic examination. These results suggest that the activation of a latent infection of Pc occurs in SIV-infected rhesus monkeys as well as in human AIDS. Experimental transmission of Pc derived from a simian was attempted in severe combined immunodeficiency (SCID) mice and athymic nude (rnu/rnu, F344) rats. These animals were inoculated intranasally with 10(4) Pc cysts, but neither histopathologic changes nor Pc organisms were detected in SCID mice at 4 months after inoculation or in nude rats at 2 months postinoculation, suggesting that simian Pc is species-specific.

Infection of macaque monkeys with a chimeric human and simian immunodeficiency virus

Two macaque monkeys were inoculated with a chimeric human and simian immunodeficiency virus carrying the tat, rev, vpu and env genes of human immunodeficiency virus type 1. Infectious virus was recovered from one of the monkeys at 2 and 6 weeks post-infection. The hybrid nature of the isolated viruses was verified by Southern and Western blotting analyses. Both of the monkeys infected with the chimera elicited a humoral antibody response against the virus.

Intracytoplasmic localization of CD3 antigen in NKH1+ azurophilic granular T-lymphoblastic lymphoma cells

The intracytoplasmic localization of CD3 antigen was examined in azurophilic granular T-lymphoblastic lymphoma cells obtained from a 27-year-old female. Examination by flow cytometry and an immunohistological method revealed that the surface phenotype of the lymphoma cells were NKH1+, CD5+, CD7+, CD1-, CD2-, CD4-, CD8- and CD16-. CD3 was not detected on the cell-surface by flow cytometry but was found in the cytoplasm using the immunohistological method. CD3 was detected in the perinuclear space and rough endoplasmic reticulum (rough ER) by an immunoelectron microscopic study. An electron microscopic observation of the granules revealed lysosomal structures with low electron density. The lymphoma cells proliferated when cultured in the presence of interleukin-2 but showed no NK (K562) activity before and after culture. The molecular size of metabolically labeled intracytoplasmic CD3 precipitated by Leu 4 monoclonal antibody was identical to that of normal CD3. These results indicate that the lymphoma cells are neoplastic counterparts of immature thymocyte at a very early stage of differentiation and may be related to the lineage of CD3+ NKH1+ T-lymphocyte.

Accessory cell function of human alveolar macrophages in antigen-induced T lymphocyte proliferation

We compared the accessory cell function of human alveolar macrophages (AM) to that of human blood monocytes (Mo) obtained by bronchoalveolar lavage and venipuncture from normal volunteers. Graded numbers of either AM or Mo were added to autologous peripheral blood T lymphocytes that were stimulated with a purified protein derivative of tuberculin (PPD). Either AM or Mo were cocultured with allogeneic T lymphocytes in mixed lymphocyte reaction (MLR) experiments. Both AM and Mo supported the PPD-induced T lymphocyte proliferation and allogeneic MLR at low ratios of AM or Mo to T lymphocytes with similar efficiency. However, AM showed marked suppressive effects at higher ratios of AM to T lymphocytes (1:1). PPD-pulsed AM, but not AM killed by physical treatments (heat, freeze-thaw, sonication), induced T lymphocyte proliferation. An indirect immunofluorescent study demonstrated that most AM express HLA-DR antigens. Furthermore, AM synthesized DR antigens with molecular weights of 33,000 and 29,000-31,000 daltons. When AM were treated with both anti-DR monoclonal antibody and complement, PPD-induced T lymphocyte proliferation and MLR were diminished. These results suggest that human AM function as accessory cells in the antigen-induced T lymphocyte proliferation and DR antigens on AM play an important role in the accessory cell function.

Immunochemical and immunohistological analyses of tumor-associated antigens defined by murine monoclonal antibodies against human pancreatic carcinoma cells

Two murine monoclonal antibodies, SK-930 (isotype IgG2a) and SK-117 (isotype IgG1), were produced from spleen cells of mice immunized against human pancreatic carcinoma cell lines, MIA-PaCa 2 and Panc-1. With the use of the avidin-biotin-immunoperoxidase technique, the SK-930 and SK-117 antibodies detected an antigen found in 24 and 23 formalin-fixed tissue sections, respectively, of tumors obtained from 30 different patients with pancreatic carcinoma. Reactivity was also frequently found with tumors of the gallbladder, bile duct, stomach, colon and esophagus, while a large panel of normal human tissues, including normal pancreatic tissues, displayed little reactivity. These observations suggest that SK-930 and SK-117 are of value in identifying tumor-associated antigen (TAA) expressed in pancreatic carcinoma and other carcinomas of the digestive system. SK-930 antibody immunoprecipitated a 134 kilodalton molecule from extracts of 125I- or [35S]methionine- or [3H]glucosamine-labeled tumor cells. The SK-117-defined antigen corresponds to 152/137 kilodalton molecules. Moreover, cytofluorometric analyses showed that cells treated with periodic acid exhibited greatly decreased reactivity to the two antibodies, but cells treated with neuraminidase, trypsin or pronase showed unchanged reactivity. The findings suggest that the epitopes of the novel TAA expressed on pancreatic carcinoma cells are carbohydrate moieties.

Monoclonal antibody against human gallbladder carcinoma-associated antigen

Monoclonal antibody HI-531 of immunoglobulin G2b subclass was produced against a human gallbladder carcinoma cell line. HI-531 was investigated for reactivity with a panel comprising ten types of different origin in fluorescence-activated cell sorter analysis. The antibody reacted with the gallbladder carcinoma cell line G-415 used for immunization and with four unrelated tumors. HI-531 was further shown, with the use of the avidin-biotin complex-immunoperoxidase technique and surgically resected tissues, to be strongly reactive with carcinoma of the gallbladder, pancreas, bile duct, and gastrointestinal tract. The antibody was reacted with several types of normal epithelial cells but often more weakly expressed than on corresponding tumors. One of six fetal lung tissues was weakly stained. All other fetal organ tissues tested showed negative staining reactions. These observations suggest that HI-531 may be of value in identifying the tumor-associated antigen expressed in gallbladder carcinoma. HI-531 immunoprecipitated the Mr 43,000 molecule from extracts of Na125I- or [35S]methionine-labeled tumor cells, but not from those of [3H]glucosamine-labeled tumor cells. In addition, cytofluorometric analysis showed that cells treated with trypsin or protease greatly decreased a reactivity to the antibody. The findings suggest that the antibody recognizes a Mr 43,000 protein molecule. Sequential immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis studies and analyses by nonequilibrium pH gradient and polyacrylamide gel electrophoreses showed that the Mr 43,000 molecule defined by HI-531 was not a Mr 43,000 heavy chain of HLA-A,B,C antigens detected by monoclonal antibody W6/32.

Characterization of human autoantibodies that selectively precipitate the 7SL RNA component of the signal recognition particle

The signal recognition particle (SRP), which consists of the 7SL RNA molecule associated with six polypeptides ranging between 9,000 and 72,000 m.w., mediates the translocation of newly synthesized proteins across the endoplasmic reticulum. We have characterized autoantibodies that are directed against this particle from two patients with rheumatic diseases. These sera immunoprecipitated the 7SL RNA from whole extracts of HeLa cells radiolabeled with 32P, but no RNA from deproteinized cell extracts. From 35S-methionine-labeled cell extracts, they immunoprecipitated a single polypeptide of 54,000 m.w. that is consistent with a known SRP component. Sucrose density gradient studies confirmed that this protein co-migrated with the 7SL RNA, indicating the likelihood that it is physically associated with this RNA. Thus, the 54,000 m.w. SRP protein, which is essential for the SRP functions of elongation arrest and translocation, appears to be a preferential target for human autoimmune responses. Human autoantibodies that recognize the SRP should be useful adjuncts to animal antisera for studies of the structure and function of this particle.

Characterization of human autoantibodies that selectively precipitate the 7SL RNA component of the signal recognition particle

The signal recognition particle (SRP), which consists of the 7SL RNA molecule associated with six polypeptides ranging between 9,000 and 72,000 m.w., mediates the translocation of newly synthesized proteins across the endoplasmic reticulum. We have characterized autoantibodies that are directed against this particle from two patients with rheumatic diseases. These sera immunoprecipitated the 7SL RNA from whole extracts of HeLa cells radiolabeled with 32P, but no RNA from deproteinized cell extracts. From 35S-methionine-labeled cell extracts, they immunoprecipitated a single polypeptide of 54,000 m.w. that is consistent with a known SRP component. Sucrose density gradient studies confirmed that this protein co-migrated with the 7SL RNA, indicating the likelihood that it is physically associated with this RNA. Thus, the 54,000 m.w. SRP protein, which is essential for the SRP functions of elongation arrest and translocation, appears to be a preferential target for human autoimmune responses. Human autoantibodies that recognize the SRP should be useful adjuncts to animal antisera for studies of the structure and function of this particle.

Effects of cerulein on the normal pancreas and on experimental pancreatic carcinoma in the Syrian golden hamster

The effects of cerulein on normal pancreas and on N-nitrobis (2-hydroxypropyl) amine (BHP)-induced experimental pancreatic carcinoma in Syrian golden hamsters were studied. Twenty hamsters received a subcutaneous injection of cerulein (20 micrograms/kg). The results showed that when cerulein was injected subcutaneously for 10 days, pancreatic weight and amylase increased. DNA and the pancreatic weight/DNA ratio were also increased significantly in treated hamsters compared with controls (p less than 0.02 versus p less than 0.01). These results indicated that chronic cerulein injection had hypertrophic and hyperplastic effects. DNA synthesis, as measured by histoautoradiography of tritiated thymidine-labeled tissue, increased in pancreatic acinar cells (p less than 0.01) and increased slightly in islet cells and in ductal cells. Tritiated thymidine uptake in the pancreas of the treated group indicated a rather selective exocrine gland incorporation by acinar rather than ductal cells. Sixty hamsters received a subcutaneous injection of BHP (500 mg/kg) once a week, while 63 hamsters received BHP (500 mg/kg) plus cerulein (20 micrograms/kg). Twenty-seven hamsters received cerulein (20 micrograms/kg) alone. All animals were killed from 8 to 27 weeks later, and no cancer-bearing hamsters were observed during the eighth and ninth week following administration. From the 10th to 14th weeks after administration of BHP and cerulein, 87.9% (13 of 15) had tumors compared with 18.7% (3 of 16) after BHP alone (p less than 0.01). One of three and two of 13 tumors were adenoma.(ABSTRACT TRUNCATED AT 250 WORDS)