Optimal blue light irradiation conditions for the treatment of acne vulgaris in a mouse model

BACKGROUND

Although blue light is one of the therapeutic approaches used to treat acne vulgaris (AV), there is no consensus on its effectiveness. As a result, it is not recommended in the major acne vulgaris treatment guidelines.

OBJECTIVE

The goal of this study was to look into the mechanism, safety, and efficacy of blue light therapy. We achieved this by examining the pathological response, inflammation, and depth of light penetration in a mouse model of cystic AV.

METHODS

The aims of the study were addressed by exposing the mice to light with a wavelength of 415 nm under four different irradiation conditions. The exposure was done for five consecutive days followed by a no irradiation period of 72 h.

RESULTS

Blue light treatment was most effective when irradiation was performed at 100 mW/cm² for 20 min for five consecutive days. Inflammatory responses emerged 72 h after the final irradiation dose was administered. These responses were not associated with apoptosis as cleaved caspase-3 staining revealed no significant increases in apoptosis in the skin under any of the tested conditions. Blue light reached the superficial layer of the acne cyst at 5% of the total irradiation power and was attenuated by half for every 50 μm of progress through the cyst.

CONCLUSION

In conclusion, blue light could control severe dermatologic inflammatory responses; therefore, it can be used to irradiate AV with high inflammation levels on a daily basis until improvement is observed. In addition, porphyrin, a metabolite of Cutibacterium acnes, and reactive oxygen species generated by the surrounding skin tissue may have essential roles in AV treatment.

Inspired by nature: Fiber networks functionalized with tannic acid and condensed tannin-rich extracts of Norway spruce bark show antimicrobial efficacy

This study demonstrated the antibacterial and antiviral potential of condensed tannins and tannic acid when incorporated into fiber networks tested for functional material purposes. Condensed tannins were extracted from industrial bark of Norway spruce by using pressurized hot water extraction (PHWE), followed by purification of extracts by using XADHP7 treatment to obtain sugar-free extract. The chemical composition of the extracts was analyzed by using HPLC, GC‒MS and UHPLC after thiolytic degradation. The test matrices, i.e., lignocellulosic handsheets, were produced and impregnated with tannin-rich extracts, and tannic acid was used as a commercial reference. The antibacterial and antiviral efficacy of the handsheets were analyzed by using bioluminescent bacterial strains (Staphylococcus aureus RN4220+pAT19 and Escherichia coli K12+pCGLS11) and Enterovirus coxsackievirus B3. Potential bonding of the tannin-rich extract and tannic acid within the fiber matrices was studied by using FTIR-ATR spectroscopy. The deposition characteristics (distribution and accumulation patterns) of tannin compounds and extracts within fiber networks were measured and visualized by direct chemical mapping using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and digital microscopy. Our results demonstrated for the first time, how tannin-rich extracts obtained from spruce bark side streams with green chemistry possess antiviral and antibacterial properties when immobilized into fiber matrices to create substitutes for plastic hygienic products, personal protection materials such as surgical face masks, or food packaging materials to prolong the shelf life of foodstuffs and prevent the spread of infections. However, more research is needed to further develop this proof-of-concept to ensure stable chemical bonding in product prototypes with specific chemistry.

Blue Laser Irradiation Decreases the ATP Level in Mouse Skin and Increases the Production of Superoxide Anion and Hypochlorous Acid in Mouse Fibroblasts

Simple Summary

Photobiomodulation studies have reported that blue light irradiation induces the production of reactive oxygen species. We examined the effect of blue laser (405 nm) irradiation on ATP level in the skin and measured the types of reactive oxygen species and reactive nitrogen species. The decrease in the skin ATP level due to blue light irradiation may be caused by oxidative stress due to the generation of reactive oxygen species. These findings highlight the need to consider the effects on the skin when performing photobiomodulation treatment using blue light.

Abstract

Photobiomodulation studies have reported that blue light irradiation induces the production of reactive oxygen species. We investigated the effect of blue laser (405 nm) irradiation on the ATP levels in mouse skin and determined the types of reactive oxygen species and reactive nitrogen species using cultured mouse fibroblasts. Blue laser irradiation caused a decrease in the ATP level in the mouse skin and triggered the generation of superoxide anion and hypochlorous acid, whereas nitric oxide and peroxynitrite were not detected. Moreover, blue laser irradiation resulted in reduced cell viability. It is believed that the decrease in the skin ATP level due to blue light irradiation results from the increased levels of oxidative stress due to the generation of reactive oxygen species. This method of systematically measuring the levels of reactive oxygen species and reactive nitrogen species may be useful for understanding the effects of irradiation conditions.

Photocrosslinked gelatin hydrogel improves wound healing and skin flap survival by the sustained release of basic fibroblast growth factor

Biomaterials traditionally used for wound healing can act as a temporary barrier to halt bleeding, prevent infection, and enhance regeneration. Hydrogels are among the best candidates for wound healing owing to their moisture retention and drug-releasing properties. Photo-polymerization using visible light irradiation is a promising method for hydrogel preparation since it can easily control spatiotemporal reaction kinetics and rapidly induce a single-step reaction under mild conditions. In this study, photocrosslinked gelatin hydrogels were imparted with properties namely fast wound adherence, strong wet tissue surface adhesion, greater biocompatibility, long-term bFGF release, and importantly, ease of use through the modification and combination of natural bio-macromolecules. The production of a gelatin hydrogel made of natural gelatin (which is superior to chemically modified gelatin), crosslinked by visible light, which is more desirable than UV light irradiation, will enable its prolonged application to uneven wound surfaces. This is due to its flexible shape, along with the administration of cell growth factors, such as bFGF, for tissue regeneration. Further, the sustained release of bFGF enhances wound healing and skin flap survival. The photocrosslinking gelatin hydrogel designed in this study is a potential candidate to enhance wound healing and better skin flap survival.

Triangular extension of hinge flaps: A novel technique to resolve stomal stenosis and prevent restenosis in staged buccal mucosal urethroplasty

OBJECTIVES

To verify the utility of triangular extension of a hinge flap in buccal mucosal staged urethroplasty to resolve stomal stenosis after the first stage and ultimately prevent restenosis.

METHODS

A total of 23 patients (triangular extension group) were studied in 2013-2019. In the first stage, buccal mucosa was transplanted, and an extended triangle portion of the mucosa was placed beside the proximal and/or distal stoma that was created when the stricture segment of the urethra was resected. In the second stage, during tubularization of the urethral plate, an incision was made at the stoma to increase the caliber to which the triangular extension was inserted. The procedure was considered successful when a 17-Fr flexible cystoscope passed through the reconstructed urethra at 6 months after the second-stage urethroplasty and no additional surgery or bougie dilation required. The clinical course of the triangular extension group was compared with 24 patients who underwent conventional staged urethroplasty (control group).

RESULTS

In total, 20 patients from each group underwent second-stage surgery. No patients in the triangular extension group required additional revision surgery because of stomal stenosis after first-stage surgery, whereas five (20%) control patients did. Urethroplasty was successful in 19 patients (95%) in the triangular extension group and in 19 patients (95%) in the control group. Uroflowmetry after the second-stage surgery indicated that the mean maximum urinary flow rate was 21.5 and 15.8 mL/s after triangular extension and the control procedure, respectively (P = 0.027).

CONCLUSIONS

The triangular extension technique reduces the need for revision surgery and prevents postoperative restenosis.

Severe Functional Loss of the Hand due to Necrotizing Fasciitis with Underlying Vasculitis Neuropathy

A 72-year-old man presented with an erythematous, painful, swollen, and blistering left hand associated with a systemic fever. The patient was diagnosed with microscopic polyangiitis and was receiving steroid therapy from a year before the incident. Based on a clinical diagnosis of necrotizing fasciitis, emergency surgery was performed within 2 days after the onset. β-Hemolytic Streptococcus group A was isolated from a culture of the blood and wound. Radical debridement and high-dose penicillin and clindamycin therapy successfully saved the patient's life and affected limb except for the second finger on his left hand, which was completely necrotic. However, the function of the left hand was seriously decreased and did not recover. The important point to note in this case was the preexisting vasculitis neuropathy due to microscopic polyangiitis. The severe postoperative dysfunction of the hand was considered to be due to ischemic neuropathy that was aggravated by compartmental syndrome and microvascular thrombosis. In conclusion, necrotizing fasciitis of an extremity with underlying vasculitis neuropathy can lead to a poor functional prognosis of the limb.

Whole Genome Sequencing of Influenza A and B Viruses With the MinION Sequencer in the Clinical Setting: A Pilot Study

Introduction: Whole genome sequencing (WGS) of influenza viruses is important for preparing vaccines and coping with newly emerging viruses. However, WGS is difficult to perform using conventional next-generation sequencers in developing countries, where facilities are often inadequate. In this study, we developed a high-throughput WGS method for influenza viruses in clinical specimens with the MinION portable sequencer.

Methods: Whole genomes of influenza A and B viruses were amplified by multiplex RT-PCR from 13 clinical specimens collected in Tokyo, Japan. Barcode tags for multiplex MinION sequencing were added with each multiplex RT-PCR amplicon by nested PCR with custom barcoded primers. All barcoded amplicons were mixed and multiplex sequencing using the MinION sequencer with 1D² sequencing kit. In addition, multiplex RT-PCR amplicons generated from each clinical specimen were sequenced using the Illumina MiSeq platform to validate the performance of MinION sequencer. The accuracy, recall, and precision rates of MinION sequencing were calculated by comparing the results of variant calling in the Illumina MiSeq platform and MinION sequencer.

Results: Whole genomes of influenza A and B viruses were successfully amplified by multiplex RT-PCR from 13 clinical samples. We identified 6 samples as influenza type A virus H3N2 subtype and 7 as influenza B virus Yamagata lineage using the Illumina MiSeq platform. The overall accuracy, recall, and precision rates of the MinION sequencer were, respectively 99.95%, 89.41%, and 97.88% from 1D reads and 99.97%, 93.28%, and 99.86% from 1D² reads.

Conclusion: We developed a novel WGS method for influenza A and B viruses. It is necessary to improve read accuracy and analytical tools in order to better utilize the MinION sequencer for real-time monitoring of genetic rearrangements and for evaluation of newly emerging viruses.

Predictive Factors Associated with Oral Intake Ability in Gastrostomy Patients Under Long-Term Care

OBJECTIVE

To determine the physical indicators associated with oral intake status and swallowing function in gastrostomy patients under long-term care.

DESIGN

Cross-sectional study.

SETTING

Thirty-one hospitals that perform gastrostomy insertion, replacement and management.

PARTICIPANTS

A total of 117 respondents from 31 hospitals in Japan underwent gastrostomy tube replacement and management between September 2012 and January 2014. Each participant underwent a gastrostomy at least 6 months prior to the study, and received long-term care either at home, a care facility, or a hospital.

MEASUREMENTS

We conducted a questionnaire survey at Japanese hospitals and used the data obtained from 117 respondents for analysis. The survey was conducted using a questionnaire form that collected information about the following items: oral intake status, sex, age, disease history, number of days elapsed since gastrostomy, residence status, modified Rankin Scale score, consciousness, oral hygiene status, articulation and phonation, voluntary saliva swallow, Modified Water Swallow Test, and Food Test.

RESULTS

Results revealed significant differences in modified Rankin Scale scores, sputum production, articulation and phonation, and voluntary saliva swallowing between patients who were orally fed and those who were not. Moreover, sputum production and voluntary saliva swallowing were strongly associated with oral intake status. Finally, sputum production, articulation and phonation, and voluntary saliva swallowing were strongly associated with swallowing function test results.

CONCLUSION

Results from this study suggested that sputum production, articulation and phonation, and voluntary saliva swallowing could be used as indicators for estimating oral intake status and swallowing function in gastrostomy patients under long-term care.

The combined use of US and MR imaging for the diagnosis of masses in the parotid region

Purpose: To evaluate the usefulness of the combination of the two non-invasive modalities US and MR imaging to diagnose masses in the parotid region.

Material and Methods: The US and MR findings of 21 patients with parotid masses were analyzed retrospectively by two radiologists without any clinical or histopathological information. The specific points evaluated were location, shape, margin, internal architecture, and intensity level on both US and MR, posterior echo enhancement on US, and capsule-like lining of the tumor on MR.

Results: The findings concerning the shape and margin on US and MR were in fairly good agreement. Concerning the findings of the internal architecture, US could reveal the minute structures of the tumor while MR demonstrated differences in the signal intensities of histological tissue types of the various tumors. The posterior echo enhancement on US and the capsule-like lining on MR of the tumors were also useful for the diagnosis.

Conclusion: Our results suggest that the combination of US and MR is useful for examining soft tissue masses in the parotid region to make a more accurate diagnosis, and not just differentiate malignant lesions from those which are benign.

The effects of ADL on recovery of swallowing function in stroke patients after acute phase

This study aimed to examine the association between the degree of recovery from dysphagia and changes in functional independence measure (FIM) items in stroke patients after acute phase by conducting a historical cohort study, because none explains the effects of activities of daily living (ADL) on recovery of swallowing function. Study patients included hospitalised stroke patients after acute phase in whom dysphagia was confirmed (n = 72). Change in nutritional intake method score was examined for association with age, days from stroke onset to admission, length of hospital stay and change in FIM score. Moreover, to examine characteristics of patients who were removed from tube feeding, all patients who required tube feeding at the time of admission were divided into two groups comprising those who required tube feeding at discharge and those who did not. A significant and positive association was observed between change in nutritional intake method and FIM for all items other than self-care of bathing, locomotion of stairs and problem solving. Patients who were removed from tube feeding were significantly younger than those who required tube feeding at the time of discharge (P < 0.041) and also showed significantly higher FIM scores for transfer and all cognitive FIM items at the time of admission (P < 0.05). This study demonstrated that nutritional intake methods improve in conjunction with FIM improvements in patients with dysphagia following the acute phase of stroke. Our results suggest that the age and cognitive function may influence the recovery of patient ability of oral intake.

Genetic variants of immunoglobulin γ and κ chains influence humoral immunity to the cancer-testis antigen XAGE-1b (GAGED2a) in patients with non-small cell lung cancer

GM (γ marker) allotypes, genetic variants of immunoglobulin γ chains, have been reported to be associated strongly with susceptibility to lung cancer, but the mechanism(s) underlying this association is not known. One mechanism could involve their contribution to humoral immunity to lung tumour-associated antigens. In this study, we aimed to determine whether particular GM and KM (κ marker) allotypes were associated with antibody responsiveness to XAGE-1b, a highly immunogenic lung tumour-associated cancer-testis antigen. Sera from 89 patients with non-small cell lung cancer (NSCLC) were allotyped for eight GM and two KM determinants and characterized for antibodies to a synthetic XAGE-1b protein. The distribution of various GM phenotypes was significantly different between XAGE-1b antibody-positive and -negative patients (P = 0·023), as well as in the subgroup of XAGE-1b antigen-positive advanced NSCLC (P = 0·007). None of the patients with the GM 1,17 21 phenotype was positive for the XAGE-1b antibody. In patients with antigen-positive advanced disease, the prevalence of GM 1,2,17 21 was significantly higher in the antibody-positive group than in those who lacked the XAGE-1b antibody (P = 0·026). This phenotype also interacted with a particular KM phenotype: subjects with GM 1,2,17 21 and KM 3,3 phenotypes were almost four times (odds ratio = 3·8) as likely to be positive for the XAGE-1b antibody as the subjects who lacked these phenotypes. This is the first report presenting evidence for the involvement of immunoglobulin allotypes in immunity to a cancer-testis antigen, which has important implications for XAGE-1b-based immunotherapeutic interventions in lung adenocarcinoma.

Imaging findings of neurogenic tumours in the head and neck region

OBJECTIVE

The aim of this study was to describe the CT, MRI and ultrasonography findings of five cases of neurogenic tumours in the head and neck region.

METHODS

Five neurogenic tumours were analysed with respect to their CT value, the presence of cystic change, target sign, lobulation, connection to the nerve and vascularity.

RESULTS

The contrast-enhanced CT (ECT) of the schwannomas demonstrated either a mass with low enhancement (two out of three cases), which reflected the predominant Antoni B components, or a mass with cystic changes, which was an Antoni A-based schwannoma displaying cystic changes (one out of three cases). On MRI, all tumours showed homogeneous and isointense signals for muscle on T₁ weighted images (T₁ WIs). T₂ weighted images (T₂ WIs) and gadolinium (Gd)-enhanced T₁ WIs demonstrated target sign in both schwannomas. Ultrasound examination showed a well-defined, ovoid or round hypoechoic mass. The direct connection to the nerve was demonstrated in two of the five cases. Lobulation was observed in only one of the five cases and cystic changes were observed in one of the five cases. In all of the cases, no vascularity was seen in power Doppler images (PDIs) obtained percutaneously.

CONCLUSIONS

Low-enhanced areas on ECTs can be specific for schwannomas, which suggests the predominance of Antoni B components. The target sign on T₂ WIs and Gd-enhanced T₁ WIs can be specific, which can be used to differentiate the two different components (Antoni A and Antoni B). The direct connection to the nerve can be a specific finding for neurogenic tumours; however, at present the sensitivity is 40%.

Hepatitis C virus NS4 protein impairs the Th1 polarization of immature dendritic cells

Dendritic cells (DCs) in chronic hepatitis C patients display impaired function, although the details remain unclear. To investigate the hepatitis C virus (HCV) protein that has the most impact on DC function, we compared five recombinant proteins and seven HCV protein genes in modulating DC phenotype and function. Immature DCs (iDCs) were established from healthy donor peripheral blood monocytes with granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-4. Lipopolysaccharide was used to establish mature DCs (mDCs). Cells were then pulsed with HCV recombinant proteins or transfected with HCV plasmids and subsequently assayed for cell surface marker expression by flow cytometry. For cytokine and proliferative T-cell response analysis, DCs were cultured with autologous CD4 T cells and tuberculin purified protein derivative (PPD). Mean fluorescent intensity of CD86 was reduced in HCV protein-pulsed iDCs. Proliferative T-cell responses and Th1 cytokine concentrations were reduced with HCV nonstructural proteins (NS), particularly with HCV NS4. HCV nonstructural proteins, particularly NS4, change the iDC phenotype and reduce antigen-specific T-cell stimulatory function with Th1 cytokine reductions.

Correlation between diagnostic accuracy and perceptibility

OBJECTIVES

To correlate diagnostic accuracy for proximal caries with perceptibility of low contrast image details using regression analysis. The other purpose was to determine the attenuation range required for proximal caries diagnosis.

METHODS

The results of the two types of observer performance tests described above were retrieved from previous studies. Recording media included in those studies were the Compuray and the Dixel, direct digital radiographic systems, and Ektaspeed Plus film. The average numbers of perceptibility of image details from five observers were calculated for each step and for every combination of contiguous steps of the aluminium test phantom from the perceptibility test. The average diagnostic accuracy for proximal caries from the same five observers was correlated with the total number of perceptible details from the phantom using regression analysis. Finally, attenuation range required for proximal caries diagnosis was calculated from the attenuation range of the phantom where the maximum correlation coefficient was obtained.

RESULTS

Maximum correlation (r=0.68) was obtained at the combination of five contiguous steps of the aluminium test phantom. Attenuation range required for proximal caries diagnosis corresponded to the 2 mm to 6 mm thickness of aluminium with acrylic block of 12 mm thickness.

CONCLUSIONS

There is a correlation between perceptibility of low contrast image details and diagnostic accuracy for proximal caries. There may be a possibility to simplify observer performance tests for proximal caries diagnosis by using the standardized phantom simulating its attenuation range.

Effects of the automatic exposure compensation on the proximal caries diagnosis

OBJECTIVE

To elucidate the effect of automatic exposure compensation (AEC) on the diagnostic accuracy of proximal caries by comparing several digital intraoral imaging systems with a film.

MATERIALS AND METHODS

Twenty-seven extracted teeth served as proximal caries samples. Three digital radiographic systems; the Compuray, the Dixel, and the Sens-A-Ray without scintillator layer, and Kodak Ekta-speed Plus films were used as recording media. Radiographs of the teeth samples were obtained with each recording medium under seven to eight different exposures including the optimum level. Six oral radiologists evaluated the possibility of proximal caries with the five-grade-confidence-scale. On digital radiographs, image manipulations were allowed after the initial assessment. Receiver operating characteristic (ROC) curves were obtained at each exposure in each recording medium. The area under the ROC curve (Az) was used as the representative value of diagnostic accuracy. Diagnostic accuracy (DA) curves were obtained by plotting averaged Az values from all observers as a function of incident exposure in each system.

RESULTS

The effect of exposure variation on the DA was slight in the film while it was significantly larger in the digital systems without AEC. Among digital systems, the effect of exposure variation was smaller in the system with AEC than those without AEC. There was no significant effect on the diagnostic accuracy even if digital image manipulation was employed.

CONCLUSION

AEC minimizes the decrease of DA due to inadequate exposures. Since it compensates for the narrow exposure range in the digital intraoral sensor systems, the system with AEC may be preferable for the clinical diagnostic tasks.

The clinical and diagnostic imaging findings of osteosarcoma of the jaw

OBJECTIVE

To clarify the valuable clinical features and diagnostic imaging findings regarding the diagnosis of osteosarcoma of the jaw (OSJ).

MATERIALS AND METHODS

The initial symptoms and diagnostic imaging findings of 10 patients with OSJ were analysed. The points analysed on the diagnostic images were as follows: any widening of the periodontal ligament space of the teeth on the periphery of the OSJ; the presence of radial spicules and Codman's triangle; any signs of bone destruction; and the patterns of osteogenesis.

RESULTS

All patients had pain and/or swelling of the affected site, and all OSJs, except for one edentulous case, showed a widening of the periodontal ligament space of the teeth on the periphery of the OSJ. Radial spicules or Codman's triangle were observed in only three cases (30%). Four out of five mandibular OSJs were osteolytic or osteolytic dominant with bone destruction, while, in contrast, four out of five maxillary OSJs were osteogenic or osteogenic dominant, and three out of the four maxillary OSJs did not show bone destruction. The osteogenic OSJ without bone destruction was similar to some benign cemento-osseous lesions of the jaw and thus was difficult to diagnose as OSJ based on the diagnostic imaging findings alone.

CONCLUSION

Even though some OSJ showed features similar to the benign tumours of the jaw bone based on the diagnostic imaging findings, the pain and swelling of the affected site, and the widening of the periodontal ligament space of the teeth on the periphery of OSJ were considered to be common findings, which may help in making an accurate diagnosis of OSJ in this limited series.

Comparison of the psychophysical properties of various intraoral film and digital systems by means of the perceptibility curve test

OBJECTIVES

To compare psychophysical properties of two intraoral films and three digital systems using the perceptibility curve (PC) test.

MATERIALS AND METHODS

A test object was used to determine the exposures and exposure differences between the total thickness of the test object and details consisting of holes of increasing depth. The PCs for the two intraoral films, UltraSpeed and EktaSpeed Plus, were constructed employing exposure and exposure differences from dose response functions. Integrals of the PCs were calculated to obtain the psychophysical properties of the two films. Psychophysical properties of the two films were compared with those of the three digital systems published previously (CDR, Dixel and Digora).

RESULTS

The PC for the EktaSpeed Plus showed a slightly higher peak than that for the UltraSpeed. Available exposure ranges were comparable. The PC for the EktaSpeed Plus was shifted to the left of the exposure axis indicating its higher sensitivity as compared with UltraSpeed. All three digital systems had narrower but higher peaks compared with the films. The integrals for the digital systems were considerably larger than those for the two film types.

CONCLUSIONS

All the three digital systems have superior psychophysical properties compared with the two tested films.

Childhood-onset schizophrenia: research update

This review is a research update of recent literature related to childhood-onset schizophrenia (onset of psychotic symptoms by age 12 years). This subgroup of patients has attracted considerable research interest because patients with a childhood onset may represent a more homogeneous patient population in which to search for risk or etiologic factors. We examine data indicating that childhood-onset schizophrenia (COS) shares the same clinical and neurobiologic features as later-onset forms of the disorder. Compared with adults with schizophrenia, however, this subgroup of patients appears to have more severe premorbid neuro-developmental abnormalities, more cytogenetic anomalies, and potentially greater family histories of schizophrenia and associated spectrum disorders. While preliminary, these data indicate that a greater genetic vulnerability may be one of the underpinnings of COS. Future studies of this subgroup may provide important clues as to the genetic basis for schizophrenia and how gene products influence certain features of the disease, such as age of onset and mode of inheritance.

Differential role of CD80 and CD86 molecules in the induction and the effector phases of allergic rhinitis in mice

Selective involvement of CD80 and/or CD86 in the differentiation of T-helper (Th)1 and Th2 was seen in several diseases. In this study, we sought to determine the differential roles of CD80 and CD86 in the induction and effector phase of allergic rhinitis using Schistosoma mansoni egg antigen (SEA) as a specific Ag. Intranasal sensitization with SEA in BALB/c mice elicited a strong Th2 response including SEA-specific IgE production, nasal eosinophilia, and IL-4 and IL-5 production by nasal lymphocytes after Ag challenge. Blockade of CD80 at the induction phase significantly inhibited these manifestations, whereas no effect was observed by CD86 blockade. In contrast, the simultaneous blockade of both CD80 and CD86 during the effector phase partially inhibited IgE and IgG(1) production and nasal eosinophilia, although either blockade of CD80 or CD86 during the phase failed to inhibit these responses. Flow cytometric analysis on nasal mononuclear cells showed that CD80 but not CD86 was preferentially expressed on non-B cells by in vitro SEA stimulation in unsensitized mice. However, both CD80 and CD86 expression were significantly augmented by in vitro SEA stimulation in sensitized mice. Our results suggest the differential roles and expression of CD80 and CD86 in the development of allergic rhinitis.

Expression of costimulatory CD80/CD86-CD28/CD152 molecules in nasal mucosa of patients with perennial allergic rhinitis

BACKGROUND

B7 molecules (CD80, CD86) and their counter-receptors, CD28 and CD152 (CTLA-4), play an important role in T cell-mediated immune responses. We previously demonstrated that B7 molecules are selectively up-regulated not only on B cells but also on T cells from the peripheral blood mononuclear cells of patients with perennial rhinitis cultured with allergen. However, the expression of CD80/CD86 molecules and their counter-receptors in nasal mucosa, the actual inflammatory site of allergic rhinitis, has not yet been clarified.

PATIENTS AND METHODS

Inferior turbinates from patients with either allergy to house dust or non-allergic rhinitis were excised and immunohistologically stained. In addition, the inferior turbinates were challenged with paper discs containing extracts of house dust and subsequently excised. Samples were double stained with immunofluorescent-labelled antibody to identify cells bearing CD86.

RESULTS

Without the nasal provocation, only the expression of CD86 was increased in nasal mucosa of patients with allergic rhinitis compared with those with non-allergic rhinitis. However, following the nasal provocation with house dust, not only CD86, but also CD80, CD28, and CD152 were significantly expressed in allergic patients. Immunofluorescent double staining revealed CD86 expression in CD19, CD1a, CD14 and CD3 lymphocytes.

CONCLUSION

These results indicate that the expression of CD80/CD86 molecules and their counter-receptors is induced in allergic patients following nasal provocation with allergen, suggesting a local amplification of allergen-specific immune responses in perennial rhinitis.

ELISPOT cloning of tumor antigens recognized by cytotoxic T-lymphocytes from a cDNA expression library

The methodology of cloning genes coding for antigens recognized by T-cells from cDNA expression libraries was improved technically by using enzyme-linked immunospot (ELISPOT) assays instead of enzyme-linked immunosorbent assays (ELISA) or bioassays to detect cytokines produced by T-cells in response to antigens. Combining large and small scale ELISPOT assays for expression cloning has the following advantages compared to conventional cDNA expression cloning: i) the number of recombinant plasmids which can be screened is greater than 10,000 per well in a 24-well plate in a large scale ELISPOT assay compared to fewer than 100 per well in a 96-well plate in an IFN-gamma ELISA or a TNF-alpha bioassay; ii) the total number of recombinant plasmids which can be screened in a routine assay is 2 x 10 (5) in only one 24-well plate in a large scale ELISPOT assay compared to 1 x 10 (5) in ten 96-well plates in an IFN-gamma ELISA or a TNF-alpha bioassay. Thus the screening efficiency of large scale ELISPOT cloning is approximately 200 times that of conventional expression cloning approaches. The efficiency of the method was confirmed by detecting the model gene RLakt from a cDNA library of a murine leukemia RL male 1.

Generation of cytotoxic T lymphocytes against autologous lung cancer cells resistant to apoptosis

BACKGROUND

[corrected] Non-small cell lung cancer (NSCLC) is resistant to conventional treatment; so the development of a new therapy is urgent.

MATERIALS AND METHODS

50 patients with NSCLC and malignant effusion were enrolled in this study. Seventeen autologous lung cancer cell lines were established. Peripheral lymphocytes and irradiated autologous tumor cell lines were co-cultured to generate cytotoxic T lymphocytes (CTL). Expression of apoptosis-related molecules were analysed by RT-PCR or FACS.

RESULTS

CTL lines were established in 2 patients. Both CTL lines were CD3+, CD8+ and MHC class I-restricted T cells and showed cytotoxic activities not only against autologous tumor cell lines but against allogenic cancer cell lines. Two lung cancer cell lines were established from one patient before and after cisplatin-based chemotherapy. The tumor cell line established after chemotherapy was apoptosis-resistant, but was sensitive to cytotoxicity of CTL.

CONCLUSION

CTL-based immunotherapy may be one of the candidates for future therapies against NSCLC.

Ny-ESO-1 expression and immunogenicity associated with transitional cell carcinoma: correlation with tumor grade

NY-ESO-1 mRNA expression in transitional cell carcinoma was investigated by reverse transcription-PCR and immunohistochemistry. NY-ESO-1 mRNA was detected in 20 of 62 (32%) tumor specimens. There was a correlation between NY-ESO-1 expression and tumor grade: 0 of 4 (0%) grade 1 (G1), 6 of 26 (23%) grade 2 (G2), and 14 of 32 (44%) grade 3 (G3) tumors were NY-ESO-1 mRNA positive. Immunohistochemical analysis using NY-ESO-1-specific monoclonal antibody ES121 showed that 2 of 14 NY-ESO-1 mRNA-expressing G3 tumors were positive for NY-ESO-1. No NY-ESO-1 staining was observed in the panel of 30 G1 or G2 tumor specimens, including 6 NY-ESO-1 mRNA-positive cases. Sera from an expanded panel of 124 patients with transitional cell carcinoma were tested for the presence of NY-ESO-1 antibody. Seropositivity was observed in 9 of 72 (12.5%) patients with G3 tumors, whereas none of 52 patients with G1 or G2 tumors produced antibody against NY-ESO-1. In the 9 positive patients with NY-ESO-1 antibody, 4 had muscular invasive tumors, and 5 had carcinoma in situ.

Sex-related differences in the initiation of allergic rhinitis in mice

BACKGROUND

Several clinical and epidemiologic studies have investigated sex differences in the prevalence of allergic rhinitis. At present, however, no reports have demonstrated such differences in experimental models with local, but not parenteral, sensitization with antigens that may reflect natural exposure to allergens. We have recently developed murine models of allergic rhinitis after repeated intranasal sensitization with antigens in the absence of adjuvants. In this study, we investigated the role of sex in the initiation of the disease in vivo.

METHODS

Male and female CBA/J and BALB/c mice were sensitized intranasally with phospholipase A2 (PLA2) and Schistosoma mansoni egg antigen (SEA), respectively, in the absence of adjuvants. After the repeated sensitization, serum Ab titers against the sensitizing antigen and nasal eosinophilia were determined. In addition, the involvement of androgen in IgE synthesis was investigated in castrated CBA/J male mice with or without testosterone administration.

RESULTS

Females produced significantly higher levels of PLA2-specific IgE than males in CBA/J mice sensitized with PLA2. On the other hand, both titers of PLA2-specific IgG1 and nasal eosinophilia did not significantly differ between the two groups. Castrated male mice produced significantly higher amounts of PLA2-specific IgE than sham-treated male mice. In addition, PLA2-specific IgE production decreased in castrated mice treated with testosterone. Sexual differences in the production of Ag-specific IgE were not seen in BALB/c mice after the sensitization with SEA.

CONCLUSION

These results suggest that sex is responsible for the production of Ag-specific IgE, but not IgG1 or nasal eosinophilia, and that androgen appears to be involved in the in vivo production of specific IgE in male mice.

A novel Fc receptor for IgA and IgM is expressed on both hematopoietic and non-hematopoietic tissues

By contrast to well-defined Fc gamma and Fc epsilon receptors, the structural and functional characteristics of Fc mu receptor are unclear. We have recently described a novel mouse Fc receptor, designated Fc alpha/mu receptor, and its human homologue, which bind both IgM and IgA. Here we show that the Fc alpha/mu receptor is expressed on mature, but not immature, B lymphocytes and acquires the ability to bind IgM and IgA antibodies after stimulation of B lymphocytes. Moreover, stimulation with phorbol 12-myristate 13-acetate increased endocytosis of IgM-coated microparticles mediated by the Fc alpha/mu receptor expressed on pro-B cell line Ba/F3 cells. We also show that the Fc alpha/mu receptor is expressed in secondary lymphoid organs, such as lymph node and appendix, kidney and intestine, suggesting an important role of the receptor for immunity in these organs.

Identification of proacrosin binding protein sp32 precursor as a human cancer/testis antigen

Serological expression cloning of antigens eliciting a humoral immune response to a syngeneic mouse sarcoma identified pem (mouse placenta and embryonic expression gene) as a new member of the cancer/testis family. To identify the human homologue of pem, mouse pem sequences and pem-related expressed sequence tags from human testis were used as PCR primers for amplification using human testis cDNA. However, rather than pem, another gene, designated OY-TES-1, was isolated and found to be the human homologue of proacrosin binding protein sp32 precursor originally identified in mouse, guinea pig, and pig. OY-TES-1 maps to chromosome 12p12-p13 and contains 10 exons. Southern blot analysis suggests the presence of two OY-TES-1-related genes in the human genome. In normal tissues, OY-TES-1 mRNA was expressed only in testis, whereas in malignant tissues, a variable proportion of a wide array of cancers, including bladder, breast, lung, liver, and colon cancers, expressed OY-TES-1. Serological survey of 362 cancer patients with a range of different cancers showed antibody to OY-TES-1 in 25 patients. No OY-TES-1 sera reactivity was found in 20 normal individuals. These findings indicate that OY-TES-1 is an additional member of the cancer/testis family of antigens and that OY-TES-1 is immunogenic in humans.

Characterization of microsphere embolism-induced impairment of learning and memory function and the cholinergic system

The impairments of learning and memory function and of the cholinergic system were examined in rats with microsphere embolism. Microsphere embolism was induced by injection of 900 microspheres with a diameter of 48 microm into the right internal carotid artery. The retention latency of a passive avoidance test was shortened and the escape latency of a water maze test was prolonged, when the animals were tested on the 5th to 10th day after the embolism, suggesting learning and memory dysfunction. Cholinergic parameters of the striatum and hippocampus, such as acetylcholine (ACh) content (67 and 60% decrease, respectively), choline acetyltransferase (ChAT) activity (45 and 56% decrease, respectively), and Bmax of muscarinic acetylcholine M1-receptor (43 and 37% decrease, respectively), were reduced on the 11th day after the embolism, suggesting attenuation of ACh synthesis and a decrease in the number of muscarinic acetylcholine M1-receptors mainly in the striatum and hippocampus. Areas not stained with triphenyltetrazolium chloride, an indication of infarction, were detected mainly in the striatum and hippocampus and partly in the frontal cortex on the 11th day after the embolism. The results suggest that an animal with microsphere embolism may be a good ischemic model with relatively sustained impairments of learning and memory function and of the striatal and hippocampal cholinergic system.

Serological analysis of BALB/C methylcholanthrene sarcoma Meth A by SEREX: identification of a cancer/testis antigen

Antigens of BALB/c methylcholanthrene-induced fibrosarcoma Meth A recognized by the host humoral immune response were investigated by serological analysis of antigens by recombinant expression cloning (SEREX). Immunoscreening a cDNA library from Meth A (Kgamma) cells (Meth A retrovirally transfected with murine IFN-gamma cDNA) with sera from BALB/c mice growing parental Meth A transplants identified 10 antigens. One of them, OY-MS-4, showed characteristics of a cancer/testis (CT) antigen. Nucleotide sequence analysis revealed that OY-MS-4 was identical to a mouse placenta and embryonic expression gene (pem) known to be selectively expressed during embryogenesis and in transformed cell lines. In adult mice, expression of OY-MS-4 was restricted to testis and placenta. Four of 6 methylcholanthrene-induced fibrosarcomas in BALB/c mice showed strong expression of OY-MS-4. In 6 T-cell leukemias, only a dimethylbenzanthracene-induced leukemia, EL4 (C57BL), showed strong expression. Two other tumors, A20.2J and P815, induced by ethylnitrosourea and methylcholanthrene, respectively, also strongly expressed OY-MS-4. The other 9 gene products identified in Meth A by SEREX were expressed in all 15 tumors tested and in a range of normal tissues. Sequence analysis of cDNA inserts coding for the SEREX-defined antigens showed no evidence of mutation. Despite the expression of OY-MS-1-10 antigens in methylcholanthrene sarcomas other than Meth A, no antibody was detected in the sera of mice bearing these other sarcomas. The basis for the unique immunogenicity of OY-MS-1-10 presented by Meth A, but not by other syngeneic tumors expressing these gene products, is unknown.

Serological analysis of BALB/C methylcholanthrene sarcoma Meth A by SEREX: identification of a cancer/testis antigen

Antigens of BALB/c methylcholanthrene-induced fibrosarcoma Meth A recognized by the host humoral immune response were investigated by serological analysis of antigens by recombinant expression cloning (SEREX). Immunoscreening a cDNA library from Meth A (Kgamma) cells (Meth A retrovirally transfected with murine IFN-gamma cDNA) with sera from BALB/c mice growing parental Meth A transplants identified 10 antigens. One of them, OY-MS-4, showed characteristics of a cancer/testis (CT) antigen. Nucleotide sequence analysis revealed that OY-MS-4 was identical to a mouse placenta and embryonic expression gene (pem) known to be selectively expressed during embryogenesis and in transformed cell lines. In adult mice, expression of OY-MS-4 was restricted to testis and placenta. Four of 6 methylcholanthrene-induced fibrosarcomas in BALB/c mice showed strong expression of OY-MS-4. In 6 T-cell leukemias, only a dimethylbenzanthracene-induced leukemia, EL4 (C57BL), showed strong expression. Two other tumors, A20.2J and P815, induced by ethylnitrosourea and methylcholanthrene, respectively, also strongly expressed OY-MS-4. The other 9 gene products identified in Meth A by SEREX were expressed in all 15 tumors tested and in a range of normal tissues. Sequence analysis of cDNA inserts coding for the SEREX-defined antigens showed no evidence of mutation. Despite the expression of OY-MS-1-10 antigens in methylcholanthrene sarcomas other than Meth A, no antibody was detected in the sera of mice bearing these other sarcomas. The basis for the unique immunogenicity of OY-MS-1-10 presented by Meth A, but not by other syngeneic tumors expressing these gene products, is unknown.

Serological analysis of BALB/C methylcholanthrene sarcoma Meth A by SEREX: identification of a cancer/testis antigen

Antigens of BALB/c methylcholanthrene-induced fibrosarcoma Meth A recognized by the host humoral immune response were investigated by serological analysis of antigens by recombinant expression cloning (SEREX). Immunoscreening a cDNA library from Meth A (Kgamma) cells (Meth A retrovirally transfected with murine IFN-gamma cDNA) with sera from BALB/c mice growing parental Meth A transplants identified 10 antigens. One of them, OY-MS-4, showed characteristics of a cancer/testis (CT) antigen. Nucleotide sequence analysis revealed that OY-MS-4 was identical to a mouse placenta and embryonic expression gene (pem) known to be selectively expressed during embryogenesis and in transformed cell lines. In adult mice, expression of OY-MS-4 was restricted to testis and placenta. Four of 6 methylcholanthrene-induced fibrosarcomas in BALB/c mice showed strong expression of OY-MS-4. In 6 T-cell leukemias, only a dimethylbenzanthracene-induced leukemia, EL4 (C57BL), showed strong expression. Two other tumors, A20.2J and P815, induced by ethylnitrosourea and methylcholanthrene, respectively, also strongly expressed OY-MS-4. The other 9 gene products identified in Meth A by SEREX were expressed in all 15 tumors tested and in a range of normal tissues. Sequence analysis of cDNA inserts coding for the SEREX-defined antigens showed no evidence of mutation. Despite the expression of OY-MS-1-10 antigens in methylcholanthrene sarcomas other than Meth A, no antibody was detected in the sera of mice bearing these other sarcomas. The basis for the unique immunogenicity of OY-MS-1-10 presented by Meth A, but not by other syngeneic tumors expressing these gene products, is unknown.

Fc alpha/mu receptor mediates endocytosis of IgM-coated microbes

IgM is the first antibody to be produced in a humoral immune response and plays an important role in the primary stages of immunity. Here we describe a mouse Fc receptor, designated Fc alpha/microR, and its human homolog, that bind both IgM and IgA with intermediate or high affinity. Fc alpha/microR is constitutively expressed on the majority of B lymphocytes and macrophages. Cross-linking Fc alpha/microR expressed on a pro-B cell line Ba/F3 transfectant with soluble IgM or IgM-coated microparticles induced internalization of the receptor. Fc alpha/microR also mediated primary B lymphocyte endocytosis of IgM-coated Staphylococcus aureus. Thus, Fc alpha/microR is involved in the primary stages of the immune response to microbes.

Anti-CD4 induced rat heart tolerance: no presence of primed T cells and regulatory mechanisms for cytotoxic T cells

Treatment with anti-CD4 monoclonal antibody (mAb) (OX38) induces heart, but not skin graft tolerance in WF (RT1u) to Lewis (RT1l) rat strain combinations. We examined differences in cellular responses between heart-bearing and skin-rejected hosts that were both treated with anti-CD4 mAb. In the tolerant LEW rats bearing WF heart transplants, the secondary WF heart but not skin grafts were accepted. On the other hand, in anti-CD4 treated WF skin-rejected hosts, both secondary WF heart and skin grafts were rapidly rejected. Spleen cells from anti-CD4 treated WF skin-rejected LEW rats but not from WF heart-bearing LEW rats received the same treatment generated CTL after in vitro stimulation with paraformaldehyde (PFA) treated donor WF stimulator spleen cells. Adoptive transfer of spleen cells from WF skin-rejected LEW rats with or without anti-CD4 therapy into the tolerant LEW rats at the secondary WF heart transplantation blocked the secondary heart graft acceptance. However, transfer of spleen cells from WF heart-rejected rats without immunosuppression failed to block acceptance of the secondary heart graft. Our results indicated the lack of primed T cells and presence of regulatory mechanisms for tissue specific T cells in anti-CD4 treated heart bearing hosts.

Sonography for the detection of cervical lymph node metastases among patients with tongue cancer: criteria for early detection and assessment of follow-up examination intervals

BACKGROUND AND PURPOSE

Because the presence of cervical metastasis is one of the factors influencing the outcome of patients with carcinoma of the head and neck, its early detection is potentially very important. The purpose of this study was to evaluate the characteristic changes of cervical metastasis revealed by sonography during follow-up and to assess an adequate interval for follow-up sonography of the neck among patients with tongue cancer.

METHODS

Forty-three of 44 consecutive patients with squamous cell carcinoma of the tongue, who had undergone interstitial brachytherapy, were examined with sonography of the neck during the posttherapeutic follow-up period.

RESULTS

Seventeen cervical lymph node metastases were found in 12 of 43 patients during follow-up. Of these 17 cervical metastases, 16 (94.1%) were accurately diagnosed and one (5.9%) was misdiagnosed as nonmetastatic based on sonographic findings. Sonography of the neck performed in seven patients at an interval of less than 1 month since the last follow-up imaging showed 9 (90.0%) of 10 metastases increased by up to 2 mm in short-axis diameter. Five patients who were followed up at an interval of more than 1 month since the last follow-up imaging had seven metastases increase by 3 to 8 mm in short-axis diameter or a change of echogenicity in the internal structure of lymph nodes or both. Pathologic examinations showed extranodal spread in 3 (42.9%) of these 7 metastases.

CONCLUSION

Changes both in size and internal echogenicity can occur as quickly as 2 to 4 weeks between sonographic examinations. Therefore, in high-risk patients, or in those with suspicious sonographic findings, short-interval follow-up sonographic examinations are recommended at least during the first posttherapeutic year. Our findings suggest that follow-up sonography of the neck should be performed monthly, at least during the first posttherapeutic year.

A study of the association between the prognosis of carcinoma of the mandibular gingiva and the pattern of bone destruction on computed tomography

OBJECTIVE

To clarify whether the pattern of bone destruction seen on CT is more closely associated with the outcome of carcinoma of the mandibular gingiva than that derived from panoramic radiographs (PR).

METHOD

Axial bone window CT scans and PR of 62 patients with carcinoma of the mandibular gingiva were evaluated retrospectively by two oral radiologists for the pattern of bone destruction. Patterns were classified into the three types: erosive, invasive and mixed. The relationship between these patterns with each imaging modality and cumulative recurrence rate, cumulative metastasis rate and cumulative survival rate, calculated by the Kaplan-Meier method, were statistically analysed by the log rank test.

RESULTS

The pattern of bone destruction derived from CT was closely associated with the cumulative metastasis rate (P < 0.05), the cumulative recurrence rate and the cumulative survival rate. In contrast, the pattern of bone destruction based on the PR was not associated with the cumulative metastasis rate (P = 0.43), the cumulative recurrence rate (P = 0.44), or the cumulative survival rate (P = 0.5).

CONCLUSION

The prognosis of patients with carcinoma of the mandibular gingiva is more closely related to a classification derived from the pattern of bone destruction on CT rather than PR. However, the number of subjects investigated in this study was not large enough to confirm our conclusions statistically. Further studies by other investigators are therefore needed.

Effective priming of cytotoxic T lymphocyte precursors by subcutaneous administration of peptide antigens in liposomes accompanied by anti-CD40 and anti-CTLA-4 antibodies

Recently it has been shown that modulation of CD40 molecules on antigen (Ag) carrying dendritic cells (DC) can bypass T cell help, resulting in priming cytotoxic T lymphocytes (CTL) specific for the Ag. In the present study we attempted to prime peptide Ag-specific CTL by a new method in which a peptide Ag in liposome (liposomal peptide), consisting of phosphatidylserine and phosphatidylcholine (3:7), was administrated subcutaneously with anti-CD40 and/or CTLA-4 monoclonal antibodies (mAb) to mice. We found that the subcutaneous administration of the liposomal peptide with both anti-CD40 and anti-CTLA-4 mAb enhanced CTL responses comparing with those induced by the liposomal peptide alone or the liposomal peptide plus each mAb. It was shown that liposomes were critical for induction of the CTL activity. Flow cytometry analysis of a peptide-bearing DC in lymph nodes (LN) and measurement of serum IL-12 indicated that anti-CD40 mAb promoted migration of DC to the LN, where DC might differentiate and acquire ability of priming CTL. These findings provide a possibility that our procedure is applicable to cancer patients.

Expression of MAGE, GAGE and BAGE genes in human liver diseases: utility as molecular markers for hepatocellular carcinoma

BACKGROUND/AIMS

The MAGE, GAGE and BAGE genes encode tumor antigens recognized by autologous cytotoxic T lymphocytes. The aim of this study was to evaluate the possibility of using these genes as molecular markers and as the targets of specific immunotherapy for human hepatocellular carcinoma (HCC).

METHODS

The expressions of MAGE-1, MAGE-3, GAGE1-6, GAGE1-2 and BAGE mRNA in 33 surgically resected HCC samples and 26 of their corresponding non-cancerous samples (11 liver cirrhosis and 15 chronic hepatitis) were studied by a reverse-transcription polymerase chain reaction, and were compared with clinicopathological parameters. The expression of MAGE-1 was also examined in 16 biopsied HCC samples.

RESULTS

MAGE-1, MAGE-3, GAGE1-6, GAGE1-2 and BAGE mRNA were expressed in 67%, 39%, 36%, 30%, and 21% of the HCC, respectively. At least one transcript was detected in 88% of the HCC, while no expression was observed in the non-cancerous livers. There was no significant correlation between the expression of any of the tumor antigens examined and the differentiation stage or size of the HCC. Especially, MAGE-1 was highly expressed in small HCC with a diameter of less than 2 cm and in well-differentiated HCC (81% and 70%, respectively), and was also expressed even in alpha-fetoprotein-negative and PIVKA-II-negative HCC (58% and 76%, respectively). The MAGE-1 expression was detected in 69% of biopsied HCC samples and the expression was high in both small and well-differentiated HCC.

CONCLUSIONS

These tumor-specific antigens can be useful as molecular markers and as the possible target molecules for the specific immunotherapy of human HCC.

Transforming activity of the RL-akt gene, a c-akt gene activated by long terminal repeat insertion in murine leukemia RL(male symbol)1 cells

The unique antigen peptide pRL1 on BALB/c radiation-induced leukemia RL(male symbol)1 cells is derived from the normally untranslated 5' region of the mouse c-akt gene. Insertion of an endogenous long terminal repeat into the first coding exon of the gene resulted in the enhanced production of an altered akt protein, RL-akt, and creation of the tumor rejection antigen peptide pRL1. In this study, we constructed an RL-akt-expressing vector to investigate the transforming ability and anti-apoptotic activity of RK-akt in NIH/3T3 cells. RL-akt-expressing clones formed more colonies than did c-akt-expressing clones in soft agar and exhibited increased saturation density, a lower serum requirement for growth, and tumorigenicity on athymic nude mice. Immunoblot analysis of subcellular protein distribution showed that a considerable proportion of RL-akt was distributed in the membrane fraction. Thus, RL-akt expressed in NIH/3T3 cells appeared to behave like the v-akt oncoprotein. Furthermore, the RL-akt gene conferred resistance to the apoptosis induced by the calcium ionophore A23187 and by ultraviolet irradiation of NIH/3T3 cells. These findings indicate that the RL-akt gene is able to transform cells and exerts an anti-apoptotic effect on recipient cells, thereby implicating the gene in leukemogenesis of RL(male symbol)1 cells.