A new class of COX-2 inhibitor, rutaecarpine from Evodia rutaecarpa

OBJECTIVE AND DESIGN

We investigated the effect of a new class of COX-2 inhibitor, rutaecarpine, on the production of PGD2 in bone marrow derived mast cells (BMMC) and PGE2 in COX-2 transfected HEK293 cells. Inflammation was induced by lambda-carrageenan in male Splague-Dawley (SD) rats.

MATERIAL

Rutaecarpine (8,13-Dihydroindolo[2',3':3,4]pyridol[2,1-b]quinazolin -5(7H)-one) was isolated from the fruits of Evodia rutaecarpa. BMMC were cultured with WEHI-3 conditioned medium. c-Kit ligand and IL-10 were obtained by their expression in baculovirus.

METHODS

The generation of PGD2 and PGE2 were determined by their assay kit. COX-1 and COX-2 protein and mRNA expression was determined by BMMC in the presence of KL, LPS and IL-10.

TREATMENT

Rutaecarpine and indomethacin dissolved in 0.1% carboxymethyl cellulose was administered intraperitoneally and, 1 h later, lambda-carrageenan solution was injected to right hind paw of rats. Paw volumes were measured using plethysmometer 5 h after lambda-carrageenan injection.

RESULTS

Rutaecarpine inhibited COX-2 and COX-1 dependent phases of PGD2 generation in BMMC in a concentration-dependent manner with an IC50 of 0.28 microM and 8.7 microM, respectively. It inhibited COX-2-dependent conversion of exogenous arachidonic acid to PGE2 in a dose-dependent manner by the COX-2-transfected HEK293 cells. However, rutaecarpine inhibited neither PLA2 and COX-1 activity nor COX-2 protein and mRNA expression up to the concentration of 30 microM in BMMC, indicating that rutaecarpine directly inhibited COX-2 activity. Furthermore, rutaecarpine showed in vivo anti-inflammatory activity on rat lambda-carrageenan induced paw edema by intraperitoneal administration.

CONCLUSION

Anti-inflammatory activity of Evodia rutaecarpa could be attributed at least in part by inhibition of COS-2.

X-chromosome inactivation analysis of isolated Reed-Sternberg cells in nodular sclerosing Hodgkin's disease

In spite of several studies of immunoglobulin (Ig) gene rearrangements in whole Hodgkin's disease (HD) tissues and in isolated single Reed-Sternberg (RS) cells, the issue of clonality of the RS cell in HD remains incompletely resolved. Analysis of X-chromosome inactivation patterns (XCIPs) can be used to determine whether cell populations are clonal in origin. By PCR amplification of the human androgen receptor (HUMARA) loci using nested primers, we have studied XCIPs in six cases of HD of the nodular sclerosing (NS) subtype in which individual RS cells were isolated by micromanipulation from formalin-fixed, paraffin-embedded tissue sections immunostained with CD30 or CD15. In order to assess whether a clonal population of RS cells might be present in NSHD tissues, we compared the XCIPs obtained from whole NSHD tissues with those obtained from single RS cells harvested from the same tissues. Whole tissues from all six cases of NSHD showed balanced HUMARA allelic patterns, whereas an average of 83% (range 77-91%) of single RS cells from each of the six tissues expressed the same high- or low-molecular weight allele, suggesting that a clonal population of RS cells was likely to be present in each case. These data are consistent with the presence of a clonal population of RS cells in NSHD tissues.

Gram-negative bacillary meningitis in adult post-neurosurgical patients

BACKGROUND

To assess the clinical features and therapeutic outcomes of gram-negative bacillary meningitis (GNBM) in adult postneurosurgical patients.

METHODS

Thirty adult patients with GNBM were included in this study. Their clinical features, laboratory data, prognostic factors, and therapeutic outcome were analyzed. The patients were 22 males and 8 females, aged 17-72 years. Seven had community-acquired infections and 23 had nosocomial infections. Two patients were associated with brain abscess.

RESULTS

The pathogens found in the 30 GNBM patients were Pseudomonas aeruginosa, Klebsiella species, Escherichia coli, Acinetobacter baumannii, and some rare pathogens including Citrobacter freundii, Serratia marcescens, Enterobacter cloacae, and Proteus mirabilis. Among these 30 patients, 8 patients with third-generation cephalosporin-resistant GNBM were identified since 1994; all infections were nosocomially acquired. Appropriate antibiotics were given to 22 patients. Eight patients did not receive appropriate antibiotic therapy. All eight died. The mortality rate in those treated with appropriate antibiotics was 14%.

CONCLUSIONS

There has been an increase of GNBM in postneurosurgical patients in recent years. In addition, the emergence of strains resistant to third-generation cephalosporins in this specific group of patients has also been noted in recent years, and has become a great therapeutic challenge. We noted many prognostic factors in postneurosurgical patients in this study; however, appropriate antibiotic therapy and initial consciousness level are the most significant ones. Therefore, in cases of postneurosurgical patients with nosocomially acquired GNBM, the possibility of third-generation cephalosporin resistance should be strongly suspected. Early initiation of appropriate antibiotic therapy is needed in this potentially fatal disease.

Recombinant human (rh)IL-4-mediated apoptosis and recombinant human IL-6-mediated protection of recombinant human stem cell factor-dependent human mast cells derived from cord blood mononuclear cell progenitors

Although stem cell factor (SCF) appears to be the major growth factor for human mast cells, other factors undoubtedly play important roles in the development, survival, and function of these cells. The current study examined the effects of recombinant human (rh) IL-4 and rhIL-6 on rhSCF-dependent development and survival of human mast cells derived in vitro from cord blood progenitor cells. After 4-8 wk of culture with rhSCF and various amounts of rhIL-4, a dramatic decline in mast cell numbers was observed with rhIL-4, the EC50 being about 0.1 ng/ml. Numbers of other cell types remained high. Mast cells derived from cord blood progenitors after 7 wk of culture with rhSCF alone displayed an MCT phenotype and expressed Kit, FcepsilonRI, and IL-4R on their surface. Mast cells examined after purification by immunomagnetic sorting became apoptotic within hours after exposure to rhIL-4, a phenomenon blocked by anti-IL-4 Ab. Because rhIL-4-dependent apoptosis but not the loss of mitochondrial membrane potential was prevented by the pan-caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-(Z-VAD)-fluoromethylketone, mitochondrial perturbation most likely preceded caspase activation. Consistent with this conclusion was the observation that both apoptosis and loss of mitochondrial membrane potential (Deltapsim) were inhibited by cyclosporin A in combination with aristolochic acid. rhIL-6 protected cord blood mast cells from rhIL-4-induced apoptosis. Thus, IL-4 can cause both maturation and apoptosis of human mast cells, the latter effect being abrogated by IL-6.

The prognostic factors of cryptococcal meningitis in HIV-negative patients

Seventy-one patients with cryptococcal meningitis, 46 males and 25 females, aged 15-83 years, were included in this study. Their initial clinical manifestations, cerebrospinal fluid (CSF) features, and therapeutic results were analysed. Patients were treated with three different regimens: amphotericin B, fluconazole, and combination therapy. Based on the therapeutic results, the 71 patients were also divided into cured, improved, and failed groups. For statistical comparison, the clinical manifestations and CSF features, were compared according to therapeutic outcome. There was no statistical difference in outcome among the three different antifungal regimens. However, patients treated with fluconazole required 36% fewer days of hospitalization compared with those receiving amphotericin B. Significant prognostic factors, included low CSF glucose, high CSF lactate, high CSF cryptococcal antigen titre (> or = 1:1024), initial level of consciousness, the presence of seizure, hydrocephalus, and central nervous system vasculitis. Multiple logistic regression analysis showed that only initial level of consciousness, and CSF antigen titre were strongly associated with therapeutic failure after other potentially confounding factors were adjusted for. Because some of the prognostic factors in cryptococcal meningitis can be corrected, early diagnosis, early use of appropriate antifungal treatment, and the correction of the underlying metabolic derangements are important in management.

Synthesis and biological acitivity of annulated pyrazoles as selective COX-2 inhibitors. I

A series of disubstituted 4,5-polymethylenepyrazoles were synthesized and evaluated their inhibitory activities against COX-2. Some compounds showed strong (0.3 nM) inhibitory activity on COX-2 and were found somewhat selective (up to 16) on COX-2 over COX-1.

Inhibition of mouse ear edema by steroidal and triterpenoid saponins

Certain steroids and triterpenoids isolated from diverse plant families were known to possess anti-inflammatory activity. In the course of finding new anti-inflammatory natural products, some steroidal and triterpenoid saponins were isolated and evaluated for their anti-inflammatory activity using in vivo mouse ear edema test. At the oral dose of 100 mg/kg, several steroidal saponins and triterpenoid saponins such as hederagenin glycosides showed significant inhibition of ear edema (20-37% inhibition), though less potent than indomethacin and hydrocortisone.

Inhibition of rat adjuvant-induced arthritis by ginkgetin, a biflavone from ginkgo biloba leaves

Ginkgetin, a biflavone isolated from Ginkgo biloba leaves, was previously reported as an inhibitor of group II phospholipase A2. In this study, ginkgetin was evaluated for in vivo antiarthritic and analgesic activities. Ginkgetin (10-20 mg/kg/day) strongly reduced arthritic inflammation in an animal model of rat adjuvant-induced arthritis (86% inhibition at 16 days at a dose of 20 mg/kg/day) via intraperitoneal injection, while prednisolone (5 mg/kg/day) showed 79% reduction. Histological examination of the knee joints confirmed our findings. When analgesic activity was measured, ginkgetin showed a dose-dependent inhibition in an animal model of acetic acid-induced writhing. ED50 values for ginkgetin and indomethacin were 8.9 and 3.8 mg/kg, respectively. All these results indicate that ginkgetin may be a potential antiarthritic agent having analgesic activity.

Endobronchial metastatic disease

BACKGROUND

Endobronchial metastasis (EM) is rare. Patients with EM are in advanced stages of disease and have poor prognoses. However, some patients have had long-term survival after aggressive treatment.

METHODS

We retrospectively reviewed the records of 9678 patients who had undergone bronchoscopic procedures. Forty patients were diagnosed as having EM.

RESULTS

The most common site of primary tumors was the head and neck [10 nasopharyngeal carcinomas (NPC), 2 buccal cancers, 2 glossal cancers, 2 laryngeal cancers]. Clinical manifestations included cough (50%), hemoptysis (20%), dyspnea (15%), and absence of respiratory symptoms (15%). The most common findings in chest roentgenograms (CXR) were single masses (40%). The median length of survival for all patients was 12 months (range, 6 to 18 months). The median length of survival in patients whose ages were over 70 years was 1 months and in patients less than 70 years old it was 12 months (range, 7 to 19 months) (p = 0.002). In patients whose EM extent was to the main bronchus, the median length of survival was 1 month (range, 1 to 3 months) and that in those whose EM did not extend to main bronchus was 12 months (range, 11 to 21 months) (p = 0.0004). In patients whose primary tumors were due to head and neck cancer other than NPC, the survival time was 1 month (range, 1 to 11 months), and in others it was 12 months (range, 7 to 19 months) (p = 0.0008).

CONCLUSION

Three factors contributed to a poor prognosis, including the patient's age being over 70 years, primary tumors due to head and neck cancer other than NPC, and extension of the endobronchial metastatic lesion to the main bronchus.

UV inducibility of rat proliferating cell nuclear antigen gene promoter

Proliferating cell nuclear antigen (PCNA), also known as a cofactor of DNA polymerase delta, is required for eukaryotic cell DNA synthesis and nucleotide excision repair. Expression of PCNA gene is growth-regulated and UV inducible. In our previous study, we have observed that the rat PCNA promoter has the serum responsiveness. In this study, we demonstrate its UV inducibility in CHO.K1 cells. The UV induction of the rat PCNA promoter activity was dose-dependent in the cells synchronized at different phases. In addition, the sequences of the promoter responsible for the UV inducibility were delimited to the region between nucleotides -70 and +125, which contains an AP-1 site and a downstream proximal ATF/CRE site. While mutation of the AP-1 site abrogated the UV inducibility, mutation of the ATF/CRE site enhanced the UV inducibility, suggesting that the two sites play different roles in the UV induction of the promoter. In addition, the role of p53 in the UV induction of rat PCNA promoter was investigated. We found that exogenous p53 was unable to mimic the UV irradiation to induce rat PCNA promoter and that the UV induction of the rat PCNA promoter was seen in p53 deficient cells. Therefore, it is unlikely that the UV induction of the rat PCNA promoter is p53 dependent.

Pseudomonas aeruginosa central nervous system infections: analysis of clinical features of 16 adult patients

BACKGROUND

The purpose of this study was to analyze the clinical features and therapeutic outcome of 16 adult patients with Pseudomonas aeruginosa central nervous system (CNS) infection. We also attempted to identify the factors that significantly influence the prognosis of this potentially fatal CNS infection.

METHODS

Sixteen adult patients with P aeruginosa CNS infection, nine men and seven women, aged from 18 to 86 years, were included in this retrospective study. The clinical features and the laboratory data of these patients were analyzed. Potential prognostic factors were compared by means of Fisher's exact test and the relative risks were estimated by odds ratio.

RESULTS

Of the 16 patients, 13 had meningitis and three had focal suppuration (two with brain abscess and one with spinal epidural abscess). The 13 meningitis patients with nosocomial or community-acquired infections were classified into two forms: the spontaneous form and the neurosurgical form. The overall mortality rate was 37.5% (6/16). In the meningitis group, the patients with the neurosurgical form had a lower mortality rate (11.1%; 1/9) than the patients with the spontaneous form (100%; 4/4), and those with community-acquired meningitis had a higher mortality rate (80%; 4/5) than those with nosocomial infections (12.5%; 1/8). All the meningitis patients who did not receive appropriate antibiotic treatment expired. The statistically significant prognostic factors included the acquisition of infection, form of infection, bacteremia, initial level of consciousness and the use of appropriate antibiotics.

CONCLUSIONS

Vigilance for P aeruginosa is particularly important in patients with predisposing factors such as head injury, neurosurgical procedures and long-term debilitating diseases. Early appropriate antibiotic therapy and neurosurgical intervention for patients with suppurative infections can bring about improved therapeutic results.

Function and sequence analyses of tumor suppressor gene p53 of CHO.K1 cells

The tumor suppressor gene p53 plays an important role in guarding genomic integrity. When induced in response to environmental results, the gene product of p53 functions as a transcription factor to transactivate genes involved in arresting the cell cycle and as a facilitator of DNA repair. In contrast, the status of p53 in Chinese hamster ovary (CHO) cells, commonly used as a model system for various studies including those involving the cell cycle and transformation, remains an enigma. In this study, the function and sequence of p53 in CHO.K1 cells were investigated. The level of p53 proteins was elevated on ultraviolet (UV) irradiation of the cells, and the proteins formed specific complexes as probed with DNA containing p53-binding sequences. Its activities toward responsive promoters were inducible by UV in a dose-dependent manner. Although p53 in CHO.K1 contained a single missense mutation at codon 211, the mutation apparently had no effect on the functional properties of the protein. The CHO.K1 cells on X-ray irradiation failed to arrest at G1 phase even when the cells were transfected with a wildtype human p53 gene, indicating that the failure probably was not caused by dysfunction of its p53, but by some other mechanism. This result is consistent with the finding that p21(Waf1/Cip1) is undetectable in UV-treated CHO.K1 cells, whereas Gadd45 is induced by UV light in the cells.

Clonality of isolated eosinophils in the hypereosinophilic syndrome

The idiopathic hypereosinophilic syndrome (IHES) is a rare disorder characterized by unexplained, persistent eosinophilia associated with multiple organ dysfunction due to eosinophilic tissue infiltration. In the absence of karyotypic abnormalities, there is no specific test to detect clonal eosinophilia in IHES. Analysis of X-chromosome inactivation patterns can be used to determine whether proliferative disorders are clonal in origin. Methylation of HpaII and Hha I sites near the polymorphic trinucleotide repeat of the human androgen receptor gene (HUMARA) has been shown to correlate with X-inactivation. In this study, we have used the polymerase chain reaction (PCR) with nested primers to analyze X-inactivation patterns of the HUMARA loci in purified eosinophils from female patients with eosinophilia. Peripheral blood eosinophils were isolated by their autofluoresence using flow cytometric sorting. Eosinophils purified from a female patient presenting with IHES were found to show a clonal pattern of X-inactivation. Eosinophil-depleted leukocytes from this patient were polyclonal by HUMARA analysis, thus excluding skewedness of random X-inactivation. After corticosteroid suppression of her blood eosinophilia, a clonal population of eosinophils could no longer be detected in purified eosinophils. In contrast, eosinophils purified from a patient with Churg-Strauss syndrome and from six patients with reactive eosinophilias attributed to allergy, parasitic infection, or drug reaction showed a polyclonal pattern of X-inactivation by HUMARA analysis. The finding of clonal eosinophilia in a patient presenting with IHES indicates that such patients may have, in reality, a low-grade clonal disorder that can be distinguished from reactive eosinophilias by HUMARA analysis. Further, the method described can be used to monitor disease progression.

Diagnosis of zygosity by questionnaire and polymarker polymerase chain reaction in young twins

We developed a zygosity questionnaire for use in young twins and assessed its validity using the results of DNA diagnosis. The participants were divided into two groups: 105 pairs of adolescent twins (12-16 years old), 47 pairs of child twins (2-12 years old), and their respective parents. The DNA diagnosis of zygosity was made with polymarker polymerase chain reaction (PCR) amplification of five loci, using the AmpliType PM PCR Amplification and Typing Kit; this method has an accuracy rate of 99.0%. A parsimonious model for each sample was established using stepwise logistic regression analysis of the 20 items of the questionnaire. The total accuracy rate of the model was satisfactory for both parental reports (three items) and self-reports (three items) of adolescent twins (97.4 and 95.6%, respectively), while that for parental reports on child twins (two items) was less satisfactory (92.5%). For adolescent twins, if DNA diagnostic workups were limited to those with discordant reports either from themselves or from their parents, the accuracy rate increased to 100% for parental reports and 98% for self-reports.

Pinusolide from the leaves of Biota orientalis as potent platelet activating factor antagonist

We investigated the effect of a new PAF antagonist pinusolide, isolated from the leaves of Biota orientalis, on PAF-induced [3H]serotinin release from rabbit platelets, hypotension and vascular permeability. Pinusolide (IC50, about 5 x 10(-6) M) inhibited specifically [3H]serotinin release from rabbit platelets when stimulated with PAF (5 x 10(-8) M), but showed no effect when induced by ADP, collagen, and thrombin. It also inhibited PAF-induced hypotension in a dose-dependent manner in rats with no effect on the hypotension induced by acetylcholine, histamine and serotonin. The inhibitory effect of pinusolide on the PAF-induced vascular permeability is less specific than the induced hypotension. These results suggest that pinusolide may prove of therapeutic value in the treatment of hypotension and a molecular design of pinusolide analogues may provide the possibility of a new PAF specific antagonists.

Serum responsiveness of the rat PCNA promoter involves the proximal ATF and AP-1 sites

We have previously shown that the rat PCNA (proliferating cell nuclear antigen) gene promoter is responsive to serum stimulation. In this study, the sequence of the promoter responsive to serum stimulation has been localized in the region between nucleotides -70 and +125 relative to the transcription initiation site. This region contains an ATF site (nucleotides -51 to -44) and an AP-1 site (nucleotides -64 to -58). Mutation at either the ATF or the AP-1 site reduced the serum responsiveness of the promoter. In gel mobility shift assays, nuclear extracts from serum stimulated cells, compared to those from quiescent cells, exhibit an increasing binding activity toward a promoter related oligonucleotide (-70 to -42) which includes the ATF site and the AP-1 site. Formation of the DNA:protein complexes requires the simultaneous involvement of ATF and AP-1 sites as either element can abrogate the complexes in the competition experiment. Both the distance and sequence are essential to complex formation. Moreover, ATF-1 but not ATF-2 (or CREB) has been identified as a major component of the complexes in the antibody supershift or interference experiment. The results of this study suggest that ATF-1 in association with other factors is involved in regulating the serum stimulation of the rat PCNA promoter activity via the proximal ATF and AP-1 sites.

The prognostic factors of adult gram-negative bacillary meningitis

Seventy-seven patients with Gram-negative bacillary meningitis (GNBM), 57 males and 20 females, aged 17-86 years, were identified at Kaohsiung Chang Gung Memorial Hospital, over an 11-year period. Fifty-four infections were community-acquired, and 23 were nosocomial; 49 were spontaneous and 28 occurred after head surgery or neurosurgery. The organisms most frequently involved were Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter. Rarer pathogens included Citrobacter species, Serratia marcescens, Enterobacter cloacae, and Proteus mirabilis. All patients who did not receive appropriate antibiotic therapy died. The mortality in those treated with appropriate antibiotics was 28%. Other statistically significant prognostic factors included septic shock, initial level of consciousness, hyperosmolar hyperglycemic nonketotic coma, disseminated intravascular coagulation, high cerebrospinal fluid lactate levels and leucocytosis. In the multiple logistic regression analysis, only appropriate antimicrobial therapy and septic shock were strongly associated with mortality even after adjusting for other potentially confounding factors. Despite the high mortality, management can be improved by early diagnosis, early use of appropriate antibiotics, and correction of underlying and associated medical derangement.

Amentoflavone, a plant biflavone: a new potential anti-inflammatory agent

Biflavonoid is one of unique classes of naturally-occurring bioflavonoids. Certain biflavonoids including amentoflavone were previously reported to have inhibitory effect on the group II phospholipase A2 activity. Amentoflavone was also found to inhibit cyclooxygenase from guinea-pig epidermis without affecting lipoxygenase. In this study, anti-inflammatory and analgesic activities of amentoflavone were evaluated. When amentoflavone was administered intraperitoneally, it showed a potent anti-inflammatory activity as determined by amelioration of croton-oil induced mouse ear edema. It also showed a potent anti-inflammatory activity in the rat carrageenan paw edema model (ED50 = 42 mg/kg) compared to the activity of prednisolone (35 mg/kg) and indomethacin (10 mg/kg). However, amentoflavone did not show a significant inhibitory activity against rat adjuvant-induced arthritis, a chronic inflammatory model. In addition, amentoflavone was found to possess a potent analgesic activity in the acetic acid writhing test (ED50 = 9.6 mg/kg) compared to the activity of indomethacin (3.8 mg/kg). These results suggest that amentoflavone may be a potential lead for a new type of anti-inflammatory agents having dual inhibitory activity of group II phospholipase A2 and cyclooxygenase.

Vitexicarpin, a flavonoid from the fruits of Vitex rotundifolia, inhibits mouse lymphocyte proliferation and growth of cell lines in vitro

Certain flavonoids having a C-2,3-double bond were reported to show an inhibitory activity against T-lymphocyte proliferation, but not against B-lymphocyte proliferation in vitro. In the course of these studies, vitexicarpin (3',5-dihydroxy-3,4',6,7-tetramethoxyflavone) isolated from the fruits of Vitex rotundifolia was found to show potent inhibition against lymphocyte proliferation. Vitexicarpin inhibited T-lymphocyte proliferation as well as B-lymphocyte proliferation at > 0.1 microM. IC50's were approximately 0.7 microM both for T- and B-cell proliferation. The inhibitory activity of vitexicarpin was reversible. Vitexicarpin also inhibited the growth of certain cancer cell lines, EL-4 and P815.9 (IC50 = 0.25-0.3 microM). These results suggest that vitexicarpin may be a potential therapeutic agent involved in inflammatory/immunoregulatory disorders such as rheumatoid arthritis and lymphomas.

Regulation of cyclooxygenase-2 and endogenous cytokine expression by bacterial lipopolysaccharide that acts in synergy with c-kit ligand and Fc epsilon receptor I crosslinking in cultured mast cells

Emerging evidence has suggested the pivotal role of mast cells in a host defense against bacterial infection. In this paper, we report that bacterial lipopolysaccharide (LPS) is a potent enhancer of the cytokine- and IgE-dependent delayed responses of IL-3-dependent mouse bone marrow-derived cultured mast cells (BMMC). LPS, although showing minimal effects, significantly augmented the c-kit ligand (KL)- or IgE-dependent expression of cyclooxygenase (COX)-2 and the attendant delayed PGD2 generation, with IL-10 and IL-4 acting as potentiating and inhibitory cytokines, respectively. The COX-2-inducing activity of LPS was mimicked by exogenous IL-1 beta. Assessment of endogenous cytokine induction revealed that IL-1 beta expression was stimulated by either LPS or exogenous IL-1 beta. IL-6 expression occurred in parallel with COX-2 expression. IL-10 expression, which lagged behind COX-2 expression, depended on exogenous IL-10, but not on LPS and IL-1 beta. Thus, LPS and IL-1 beta exhibited similar biological activities in terms of COX-2 and endogenous cytokine expression. However, adding an antibody against the type I IL-1 receptor to BMMC, which abrogated the effects of IL-1 beta, failed to neutralize the effects of LPS. These results suggest that LPS activates BMMC through the signal transduction pathway shared with exogenous IL-1 beta, rather than exerting its action indirectly via the production of endogenous IL-1 beta.

Analysis of corneal topography after excimer laser photorefractive keratectomy

Excimer laser photorefractive keratectomy (PRK) is an effective treatment for myopia. We investigated the magnitude of optical zone decentration and qualitative patterns of corneal topography after this treatment. We performed computer-assisted videokeratography on 44 myopic eyes (29 patients) that had undergone PRK before and 1, 6, and 12 months after the procedure. Associations of clinical outcomes with decentration and topographic patterns were assessed. The normalized scale of the topography 1 month postoperatively showed a mean decentration of 0.33 +/- 0.23 mm (range 0-0.9). Thirty-four eyes had decentration of less than 0.50 mm; 10 had an ablation zone decentered from 0.5 to 0.9 mm. Analysis of geometric mean visual acuities between eyes with less than 0.5 mm decentration and those with 0.5 to 0.9 mm decentration demonstrated minimal differences. No eye was decentered more than 1 mm. Four main ablation patterns were noted on subtraction analysis: homogeneous, semicircular, keyhole, and central island. Over time, the number of eyes with a homogeneous pattern increased. Eyes with a homogeneous ablation pattern had significantly better uncorrected visual acuity than those with other patterns. The mean visual acuity was 20/29.1 in the homogeneous group and 20/38.5 in the pooled irregular group 1 month postoperatively (p < 0.05). There was no significant difference among the four ablation patterns at 6 or 12 months after PRK. Topographic patterns were not significantly associated with best-corrected vision.

Oncogenic transformation induced by the Qin protein is correlated with transcriptional repression

The retroviral oncogene qin codes for a protein that belongs to the family of the winged helix transcription factors. The viral Qin protein, v-Qin, differs from its cellular counterpart, c-Qin, by functioning as a stronger transcriptional repressor and a more efficient inducer of tumors. This observation suggests that repression may be important in tumorigenesis. To test this possibility, chimeric proteins were constructed in which the Qin DNA-binding domain was fused to either a strong repressor domain (derived from the Drosophila Engrailed protein) or a strong activator domain (from the herpes simplex virus VP16 protein). The chimeric transcriptional repressor, Qin-Engrailed, transformed chicken embryo fibroblasts in culture and induced sarcomas in young chickens. The chimeric activator, Qin-VP16, failed to transform cells in vitro or in vivo and caused cellular resistance to oncogenic transformation by Qin. These data support the conclusion that the Qin protein induces oncogenic transformation by repressing the transcription of genes which function as negative growth regulators or tumor suppressors.

Transformation of chicken cells by the gene encoding the catalytic subunit of PI 3-kinase

The avian sarcoma virus 16 (ASV 16) is a retrovirus that induces hemangiosarcomas in chickens. Analysis of the ASV 16 genome revealed that it encodes an oncogene that is derived from the cellular gene for the catalytic subunit of phosphoinositide 3-kinase (PI 3-kinase). The gene is referred to as v-p3k, and like its cellular counterpart c-p3k, it is a potent transforming gene in cultured chicken embryo fibroblasts (CEFs). The products of the viral and cellular p3k genes have PI 3-kinase activity. CEFs transformed with either gene showed elevated levels of phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate and activation of Akt kinase.

Loss of expression of the p16 gene is frequent in malignant skin tumors

Expression of the p16 gene from 30 malignant skin tumors has been surveyed by immunohistochemical assay. Gene point mutations were detected by DNA direct sequencing and the mRNA level of gene expression was measured by RT-PCR. A silent point mutation of the p16 gene was found in only one patient. However, loss of expression of the p16 gene was noticed in 23 of 29 samples (79.3%). Correlation between loss of expression of the p16 gene and metastasis is significant (p = 0.0036). These findings suggest that loss of expression of the p16 gene may play a critical role in tumor progression of malignant skin tumors.