YKL-39, a human cartilage-related protein, induces arthritis in mice

OBJECTIVE

To determine whether YKL-39, a recently cloned secretory protein of articular chondrocytes, is arthritogenic in mice.

METHODS

Recombinant YKL-39 (rYKL-39) was expressed and purified from E. coli. To induce arthritis in mice, rYKL-39 (1, 10 or 50 g in Freund's incomplete adjuvant) was injected into the right footpad of mice from four different strains (BALB/c, DBA/1J, C57BL/6 and ICR). The mice received a second immunization with rYKL-39 by intradermal injection into the root of the tail 10 days after the first immunization. Severity of arthritis was assessed by scoring each paw on a scale from 0 to 4. Sixty days after thefirst immunization, the mice were sacrificed and the joints were examined by immunohistochemistry and radiography. The anti-YKL-39 and anti type II-collagen (CII) antibody titres were also assayed using ELISA.

RESULTS

Immunization with YKL-39 induced arthritis in all strains of mice tested, among which BALB/c was most susceptible. Histological examination showed synovial proliferation and irregularity of the cartilage surface in YKL-39-injected BALB/c mice. Moreover radiographic analysis revealed pathological changes in these mice. The YKL-39-immunised mice produced not only anti-YKL-39 antibody but also antibody against type II collagen, suggesting a spreading of autoimmunity after YKL-39.

CONCLUSIONS

YKL-39, a cartilage-related protein, is found to induce arthritis accompanied by pathologic changes in bone and cartilage. A better understanding of the immune response against cartilage-related components including YKL-39 may help to elucidate the pathological processes of arthritic disorders.

A case of idiopathic spinal epidural lipomatosis presented with radicular pain caused by compression with enlarged veins surrounding nerve roots

OBJECTIVE

To report a case of idiopathic spinal epidural lipomatosis (SEDL) presented with unique radicular pain most likely caused by enlarged veins surrounding nerve roots.

PATIENT

A 26-year-old male presented with radicular pain of the right T6-T7 area. He also showed Becker's nevus in the corresponding area. CT myelography and magnetic resonance imaging revealed epidural lipomatosis posterior to T4-T8 of the spinal cord. Surgical removal of adipose tissue and a hemilaminectomy of T4-T7 were performed and resulted in relief of the radicular pain.

CONCLUSIONS

Lipomatosis was histologically confirmed and surrounded by enlarged veins. These abnormally enlarged veins compressed the nerve roots and were thought to cause radicular pain. Also, Becker's nevus of this case seems to have some relationship with SEDL.

[Epidemiological investigation of tinea pedis in groups of healthy students, research workers and females wearing boots]

The infection rate, causative dermatophytes, and dermatophyte dissemination of tinea pedis in young healthy Japanese were studied by direct microscopic examination, slant cultures, and foot-press culture method. Questionnaires on subjective symptoms and treatments were also distributed. Among fifty-eight medical students with a mean age of 23.9 years, thirteen (22.4%) showed positive by direct microscopic examination and T. mentagrophytes was more dominant than T. rubrum by slant cultures. In one hundred and sixteen student feet, twelve were infected and disseminating dermatophytes, four were infected but not disseminating, three were not infected but adhering dermatophytes. The infection rate of tinea pedis was thus 24.1%. Among thirty-seven research workers (mean age: 34.8), twenty-one (56.8%) showed positive by direct microscopic examination. All the dermatophytes isolated by slant cultures were T. mentagrophytes. In seventy-four feet, twenty-nine were infected and disseminating, ten were infected but not disseminating, and three were adhering dermatophytes. The infection rate was 64.9%. Among thirty-one females wearing boots (mean age: 21.0), seven (22.6%) were infected and T. mentagrophytes was more dominant. In sixty-two feet, eight were infected and disseminating, one was infected but not disseminating, and five were adhering dermatophytes. The infection rate of tinea pedis was quite high and T.r/T.m rate was low in the three groups. Most of the patients had had no treatment and were disseminating dermatophytes.

Role of chemokines/chemokine receptor systems in cartilage degradation

The underlying mechanism of the degradation of articular cartilage is an imbalance between anabolic and catabolic pathways, which are under the control of cytokines. Chemokines are a novel class of small cytokines and have a wide range of effects in many different cell types, both inside and outside of the immune system. Their actions are mediated by a family of 7-transmembrane G-protein-coupled receptors. Recent studies have demonstrated that chondrocytes co-express chemokines and their receptors, and that the interaction of chemokines with their receptors results in the release of cartilage matrix-degrading proteinases, and affect proteoglycan metabolism in chondrocytes. These data reveal a catabolic pathway primed by chemokine/chemokine receptor system in articular cartilage, thus proposing a novel therapeutic approach against cartilage destruction in arthropathy.

Remission of the renal involvement in a patient with primary Sjögren's syndrome (SS) after pulse high-dose corticosteroid infusion therapy

We report the case of a young female patient with primary Sjögren's syndrome (SS). In addition to sicca symptoms she also suffered from progressive renal insufficiency and renal tubular acidosis (RTA). She was treated with three sets of pulse high-dose corticosteroid infusion and subsequent low-dose corticosteroid oral administration. When the efficacy was evaluated about 6 months after the start of the therapy, dramatic improvements were seen with no adverse effects, not only in laboratory tests but also histopathologically, as indicated by the repeat kidney biopsy. This suggests that renal involvements of SS might be reversible in some cases, and that there might be a clinical benefit of pulse high-dose corticosteroid infusion therapy in SS with progressive renal involvement.

Endophytic colonization and in planta nitrogen fixation by a Herbaspirillum sp. isolated from wild rice species

Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum, Ideonella, Enterobacter, and Azospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and (15)N(2) gas incorporation assays. Therefore, we conclude that Herbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis.

Stress response, tachykinin, and cutaneous inflammation

In the last decade, several new aspects of glucocorticoid (GC)-actions on immune cells have been recognized. This recognition has been largely obtained through clinical observations of stress-induced exacerbations of certain dermatologic diseases. To clarify whether GC modulates cutaneous inflammatory reactions besides its known anti-inflammatory effect, first we examined the effect of long-term application of topical GC on several kinds of inflammatory responses induced in the murine model and demonstrated that these regimens significantly augmented the classical contact sensitivity reaction, the croton oil-induced irritant reaction, and the IgE-mediated biphasic cutaneous reaction. In addition, large dose topical steroid and its withdrawal enhanced scratching behavior in hapten-challenged mice. This augmented scratching behavior correlated with the induction of preprotachykinin mRNA expression in the challenged skin. In an in vitro experiment, a low-dose, stress-induced level of glucocorticoid significantly upregulated hapten-induced proinflammatory cytokine (IL1alpha) production by murine keratinocyte cell line Pam 212 and induced substance P peptide production from cultured human keratinocytes. Our results suggest that unsuitable use of GC in addition to stress-induced GC may modulate immune function in the skin through aberrant production of tachykinin, such as substance P or other epidermal cell derived cytokines.

Expression of Fas-associated death domain-like interleukin-1beta-converting enzyme (FLICE) inhibitory protein (FLIP) in human articular chondrocytes: possible contribution to the resistance to Fas-mediated death of in vitro cultured human articular chondrocytes

Although chondrocyte apoptosis has been noted in arthritic joints, the mechanism is not clear. To investigate whether Fas-mediated apoptosis has a role in this process, the presence of Fas mRNA and expression of cell surface Fas protein in monolayer-cultured human articular chondrocytes was analyzed. Fas mRNA was found in all chondrocyte samples analyzed; moreover, the majority of cells in chondrocyte populations expressed cell-surface Fas (12-90%, average 49%). Nevertheless, treatment with an agonistic anti-Fas antibody did not induce significant apoptosis in these chondrocytes in vitro. However, it was also found that chondrocytes express Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (FLIP), a molecule which blocks Fas-mediated apoptosis. Correspondingly, activation of caspase-8 was minimal in these cultured chondrocytes. In conclusion, although human articular chondrocytes do express cell-surface Fas, this receptor did not fully mediate death-inducing signals in vitro. This resistance to Fas may be partly due to the constitutive expression of FLIP.

Disappearance of clonally expanded T cells after allogeneic leukocyte immunotherapy in peripheral blood of patients with habitual abortion

Allogeneic leukocyte immunotherapy is often used to improve fertility of patients with habitual abortion (HA), which probably acts through immune-mediated mechanisms. However, the involvement of T cells is not clear. This study examined the effect of allogeneic immunotherapy on T cells of patients with HA. Peripheral blood mononuclear cells were obtained from 5 healthy women and 14 women with HA. RNA was isolated from mononuclear blood cells. Reverse transcription-polymerase chain reaction (RT-PCR), followed by single-strand conformational polymorphism (SSCP) were used to analyze the gene segments of T-cell receptor beta chain (TCRbetaV) variable regions. Oligoclonal accumulation of T cells was identified in peripheral blood of nonpregnant patients with a history of HA. It was also revealed, however, that immunostimulation reduced the number of accumulating T-cell clones (p = 0.0004). The results, together with the clinical effectiveness of immunotherapy, suggest that accumulation of T-cell clonotypes, which probably resulted from antigenic stimulation, is involved in the pathogenesis of HA.

[Questionnaire research of the participants in a large scale walking event Fukuoka City analysis of walking habits and related factors]

PURPOSE

We examined the walking habits of the participants in the 'AIREF Spring Walk' which was held on March 9, 1997 in the western suburb of Fukuoka City. The aim of this walking event was to motivate the citizens, especially sedentary people, to walk by providing them an opportunity to enjoy walking.

METHODS

The participants walked one of three distances (5 km, 10 km or 20 km) and answered anonymously a questionnaire immediately after finishing (100% response rare). The questionnaire items covered sex, age, district of residence, the distance of the walking course, the source of information on the event, experience of participating in other walking events in the past, and walking habits.

RESULTS

The participants of this event (n = 1,039, mean age 49.4 +/- 18.9 [SD] years) were characterized by high rates for females (67%), those aged < 50 years (42%), residents of Fukuoka City (89%), those who chose to walk the shorter courses of 5 or 10 km (74%), and those who took part in a walking event for the first time (61%). Information on the event was obtained through other people (32%) such as friends, acquaintances, members of community walking groups or other family members, leaflets (21%) placed in the Fukuoka Health Promotion Center and seven Fukuoka City public health centers; a newspaper published biweekly by the municipal government (13%); and direct mail (11%). For those attending the 5 km course, more participants learned about the event through other family members compared with the other two courses. Participants who answered that they walked regularly constituted 56% of those aged 20 years or older. The rates for regular walkers significantly increased with the older participants (p < 0.01) and those who chose longer courses (p < 0.001). Compared with the regular walkers, those without a walking habit tended to have acquired information on the event from friends, acquaintances or other family members, or at their work sites (35%). The average amount of time spent was 249 +/- 175 min/week (n = 375). As a whole, only 30% of the participants aged 20 years or older walked longer than the amount of time for aerobic exercise recommended by the Health, Labor and Welfare Ministry (HLWM). The rate for those who reached the HLWM recommendations was increased in older subject (p < 0.001).

CONCLUSIONS

It is concluded that the aim of the walking event was partly accomplished, which was reflected by the relatively high rates of participation sedentary for people, compared with other large walking events. The sedentary participants tended to choose the relatively short distances and obtain the information about the event through other people. Walking promotion programs should be developed to motivate sedentary citizens to walk. The programs should also support regular walkers, many of whom are 50 years old or older, to maintain walking habits with the HLWM recommendations on aerobic exercise.

Diabetes mellitus prevents ischemic preconditioning in patients with a first acute anterior wall myocardial infarction

OBJECTIVES

This study was undertaken to assess whether prodromal angina could have beneficial effects in diabetic patients with acute myocardial infarction (AMI).

BACKGROUND

Prodromal angina occurring shortly before the onset of AMI is associated with favorable outcomes by the mechanism of ischemic preconditioning. However, little is known about the impact of diabetes on ischemic preconditioning.

METHODS

We studied 611 patients with a first anterior wall AMI who underwent emergency catheterization within 12 h after the onset of chest pain: 490 patients without diabetes and 121 patients with non-insulin treated diabetes. Prodromal angina was defined as angina episode(s) occurring within 24 h before the onset of AMI. Serial contrast left ventriculograms were obtained in 424 patients at the time of acute and predischarge catheterization.

RESULTS

In non-diabetic patients, prodromal angina was associated with lower peak creatine kinase (CK) value (3,068 +/- 2,647 IU/l vs. 3,601 +/- 2,462 IU/l, p = 0.037), larger increase in left ventricular ejection fraction (LVEF) (10.1 +/- 13.0% vs. 5.8 +/- 13.4%, p = 0.004) and lower in-hospital mortality (3.4% vs. 9.3%, p = 0.015). On the contrary, in diabetic patients, there was no significant difference in peak CK value (3,382 +/- 2,520 IU/l vs. 3,233 +/- 2,412 IU/l, p = NS), the change in LVEF (6.7 +/- 13.8% vs. 7.1 +/- 12.4%, p = NS) and in-hospital mortality (8.8% vs. 11.0%, p = NS) between patients with and patients without prodromal angina.

CONCLUSIONS

Prodromal angina limited infarct size, enhanced recovery of LV function and improved survival in non-diabetic patients with AMI. However, such beneficial effects of prodromal angina were not observed in diabetic patients, suggesting that diabetes might prevent ischemic preconditioning.

Expression of notch homologues in the synovium of rheumatoid arthritis and osteoarthritis patients

Notch is known as a receptor that controls differentiation or proliferation in various cells and is associated with several diseases. The objective of the present study was to clarify whether human Notch homologues Notch-1, -2, -3, and -4 are expressed in synovium and synoviocytes from rheumatoid arthritis (RA) and osteoarthritis (OA) patients. Immunohistochemical staining showed that Notch-1, -2, and -3 were clearly expressed in the synovium from both RA and OA, whereas Notch-4 was only slightly detected. We further performed Western blotting with the same antibodies used in immunohistochemical staining. Notch-1 and -2 were strongly detected in both RA and OA, and the expression of Notch-3 was slightly detected, while there was no Notch-4 expression in both RA and OA synoviocytes. In contrast, all Notch homologues were strongly expressed in the synovium at the developmental stage obtained from the infant. These results indicate that the expression pattern of Notch among synovium from OA and RA patients differed from that of normal subjects.

Acute exanthematous pustular drug eruption induced by mexiletine

A 56-year-old man developed infiltrated erythemas on the trunk, extremities, and face with marked facial edema, one month after taking mexiletine hydrochloride for his arrhythmia. A number of pustules were also noted on the surface of erythemas on his chest and face. Laboratory examination showed liver dysfunction and hypereosinophilia. The culture from pustules was sterile. Histological examination of the biopsied skin from a pustular lesion revealed a subcorneal abscess, and perivascular infiltration of lymphocytes, mononuclear cells and eosinophils in the upper dermis. The skin lesions and facial edema as well were improved within three weeks by withdrawal of mexiletine hydrochloride. Patch tests with 10% and 20% mexiletine hydrochloride in petrolatum showed positive reaction, however, pustules were not provoked on the tested site. We conclude that pustules, infiltrated erythema and facial edema were the signs of acute exanthematous pustular drug eruption induced by mexiletine hydrochloride.

Gammadelta T cells assist alphabeta T cells in the adoptive transfer of contact hypersensitivity to para-phenylenediamine

Para-phenylenediamine (PPD) is known to be a common sensitizer of allergic contact dermatitis and contact urticaria. To clarify the mechanism of contact hypersensitivity (CHS) to PPD, we established a mouse model of PPD-induced CHS. BALB/c mice were immunized for 3 consecutive days by painting topically a 2.5% PPD solution on their shaved abdominal skin. On days 5, 7 or 9 after the initial application, the mice were challenged by applications of a 2.5% PPD solution. Maximal ear swelling was determined at 24 h but another statistically significant and smaller ear swelling was observed 1 h after challenge with PPD in a hapten-specific manner. Adoptive cell transfer experiments demonstrated that the ear swelling of the adoptive cell transferred mice displayed an early response at 6 h and a late response from 12 h to 24 h when the recipient mice were challenged immediately after transfer. Both MoAbs and complement treatment of the transferred cells demonstrated that the phenotype of the early response cells which elicited a response at 6 h after challenge was Thy1(+), B220(+), alphabeta TCR(-), gammadelta TCR(-), CD3(-), CD4(-), CD5(+) and CD8(-). The in vitro treatment of effector cells with MoAbs against not only alphabeta TCR but also gammadelta TCR, together with complement, was found to diminish substantially the late response, elicited 12-24 h after challenge. Gammadelta T cells reconstituted the ability of alphabeta T cells to transfer 24 h CHS responsiveness. The phenotype of the gammadelta T cells that assist CHS effector alphabeta T cells was CD3(+), CD4(-) and CD8(+) and these regulatory gammadelta T cells were neither Ag-specific nor MHC-restricted. Furthermore, gammadelta T cells from normal spleen could also assist alphabeta T cells in adoptive transfer of the 24 h CHS response in a non-MHC-restricted manner. RT-PCR demonstrated that alphabeta T cells strongly expressed mRNA IFN-gamma, whereas gammadelta T cells expressed not only IFN-gamma but also IL-4 and IL-10. These data indicate that not only early response cells and alphabeta T cells but also Th2 type gammadelta T cells may play an important role in the elicitation of CHS to PPD.

Impact of diabetes mellitus on long term survival after acute myocardial infarction in patients with single vessel disease

OBJECTIVE

To assess the influence of diabetes on long term prognosis after reperfusion treatment and its interaction with multivessel disease.

DESIGN

A retrospective observational study.

SETTING

Hiroshima City Hospital.

PATIENTS

1660 consecutive patients with acute myocardial infarction who underwent coronary angiography within 24 hours after the onset of chest pain.

MAIN OUTCOME MEASURES

Influence of diabetes on 10 year survival after infarction was assessed using the generalised Wilcoxon test and Cox's proportional hazards regression. Follow up was completed in 1622 patients (98%).

RESULTS

Diabetic patients had more multivessel disease than non-diabetic patients (53% v 34%, p < 0.001). When only patients with single vessel disease were compared, diabetes was associated with a reduced 10 year survival after infarction (p = 0.002). On the other hand, in patients with multivessel disease there was no significant difference in survival between diabetic and non-diabetic patients (p = 0.70). Multivariate analysis also showed that diabetes was an independent risk factor related to 10 year mortality after infarction in patients with single vessel disease (odds ratio (OR) 1.81, 95% confidence interval (CI) 1.27 to 2.54; p = 0.001) and not in patients with multivessel disease (OR 1.17, 95% CI 0.85 to 1.60; p = 0.34).

CONCLUSIONS

Diabetes is an independent predictor of long term mortality after infarction in patients with single vessel disease. However, in the presence of multivessel disease, prognosis after infarction is impaired regardless of diabetes, and the influence of diabetes is less obvious.

Impact of diabetes mellitus on long term survival after acute myocardial infarction in patients with single vessel disease

OBJECTIVE

To assess the influence of diabetes on long term prognosis after reperfusion treatment and its interaction with multivessel disease.

DESIGN

A retrospective observational study.

SETTING

Hiroshima City Hospital.

PATIENTS

1660 consecutive patients with acute myocardial infarction who underwent coronary angiography within 24 hours after the onset of chest pain.

MAIN OUTCOME MEASURES

Influence of diabetes on 10 year survival after infarction was assessed using the generalised Wilcoxon test and Cox's proportional hazards regression. Follow up was completed in 1622 patients (98%).

RESULTS

Diabetic patients had more multivessel disease than non-diabetic patients (53%v 34%, p < 0.001). When only patients with single vessel disease were compared, diabetes was associated with a reduced 10 year survival after infarction (p = 0.002). On the other hand, in patients with multivessel disease there was no significant difference in survival between diabetic and non-diabetic patients (p = 0.70). Multivariate analysis also showed that diabetes was an independent risk factor related to 10 year mortality after infarction in patients with single vessel disease (odds ratio (OR) 1.81, 95% confidence interval (CI) 1.27 to 2.54; p = 0.001) and not in patients with multivessel disease (OR 1.17, 95% CI 0.85 to 1.60; p = 0.34).

CONCLUSIONS

Diabetes is an independent predictor of long term mortality after infarction in patients with single vessel disease. However, in the presence of multivessel disease, prognosis after infarction is impaired regardless of diabetes, and the influence of diabetes is less obvious.

Survival of non-small cell lung cancer patients with postoperative recurrence at distant organs

BACKGROUND

Recurrence after complete resection of non-small cell lung cancer (NSCLC) is often observed. However, its influence on the prognosis of patients with recurrence is still unclear.

PATIENTS AND METHODS

Of 468 consecutive patients with NSCLC undergoing complete resection during 10 years, 118 experienced recurrence at distant organs. In such patients, the influence of the following variables on post-recurrent survival was analyzed; sex, age at recurrence, disease-free interval, cell type, pathological (p-) stage at operation, adjuvant therapy (thoracic radiation and/or chemotherapy), site of recurrence, and treatment against recurrence. To identify independent factors, multivariate analysis was performed for variables which were considered to be influential in univariate analysis.

RESULTS

Mean post-recurrent survival time was 418 days, and survival rate at 2-years was 15.7%. Multivariate analysis revealed that female, early p-stage, younger age at recurrence, metastasectomy and intra-pulmonary metastasis were the significant favorable factors in patients with distant metastases. Adjuvant therapy and bone metastasis were marginally significant unfavorable factors. Chemotherapy for recurrence tended to prolong survival. Length of disease-free survival and post-recurrent survival exhibited a positive relationship with p-stage. Seven out of 16 patients who underwent metastasectomy survived more than 1000 days after recurrence.

CONCLUSIONS

Patients even with recurrence in distant organs could expect for long survival if they are in the early p-stage of primary cancer or a resectable recurrent disease.

Clinical significance of CDC25A and CDC25B expression in squamous cell carcinomas of the oesophagus

CDC25A, CDC25B and CDC25C belong to a family of protein phosphatases which activate the cyclin-dependent kinase at different points of the cell cycle. According to accumulating evidence, CDC25A and CDC25B seem to possess oncogenic properties. We have analysed these expressions by immunohistochemistry, western blot and RT-PCR in a series of 100 patients with squamous cell carcinoma of the oesophagus. When compared with non-cancerous cells, CDC25A and CDC25B were strongly expressed in the cytoplasm of cancer cells, with positive (+) classification in 46% (46 cases) and 48% (48 cases), respectively. There was no significant correlation between CDC25A and CDC25B expression, nor was there any association with the expression of other cell cycle-regulating molecules, including cyclin D1, Rb, p16(INK4), p27(KIP1)and PCNA (proliferating cell nuclear antigen). CDC25A (+), as well as CDC25B (+), was more frequently found in patients with deeper tumour invasion and lymph node metastasis, while tumour size was correlated only with CDC25A expression. Postoperative survival was significantly poorer for CDC25A (+) patients than CDC25A (-) patients, but was not affected by the CDC25B status. Nuclear localization of CDC25A was observed in 51 cases (51%), regardless of its cytoplasmic expression, and was not associated with clinico-pathological factors or prognosis. Multivariate analysis revealed only the CDC25A status to be an independent significant prognostic factor among these biological and clinico-pathological factors. CDC25A but not CDC25B may be a new prognostic factor for squamous cell carcinoma of the oesophagus. Thus, regulation of the G1 checkpoint in the cell cycle may be important in oesophageal carcinogenesis, which may also involve many other oncogenes.