IL10 receptor is a novel therapeutic target in DLBCLs.

Diffuse large B-cell lymphoma (DLBCL) is a biologically and clinically heterogeneous disease with marked genomic instability and variable response to conventional R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy. More clinically aggressive cases of DLBCLs have high level of circulating interleukin 10 (IL10) cytokine and evidence of activated intracellular STAT3 (signal transducer and activator of transcription 3) signaling. We investigated the role of IL10 and its surface receptor in supporting the neoplastic phenotype of DLBCLs. We determined that IL10RA gene is amplified in 21% and IL10RB gene in 10% of primary DLBCLs. Gene expression of IL10, IL10RA and IL10RB was markedly elevated in DLBCLs. We hypothesized that DLBCLs depend for their proliferation and survival on IL10-STAT3 signaling and that blocking the IL10 receptor (IL10R) would induce cell death. We used anti-IL10R blocking antibody, which resulted in a dose-dependent cell death in all tested activated B-cell-like subtype of DLBCL cell lines and primary DLBCLs. Response of germinal center B-cell-like subtype of DLBCL cell lines to anti-IL10R antibody varied from sensitive to resistant. Cells underwent cell cycle arrest, followed by induction of apoptosis. Cell death depended on inhibition of STAT3 and, to a lesser extent, STAT1 signaling. Anti-IL10R treatment resulted in interruption of IL10-IL10R autostimulatory loop. We thus propose that IL10R is a novel therapeutic target in DLBCLs.

Pressure ulcers of the popliteal fossae caused by thromboembolic deterrent stockings (TEDS).

INTRODUCTION: Thromboembolic deterrent (TED) stockings are commonly used in the prevention of deep venous thrombosis. We would like to highlight a potential complication associated with the use of TED stocking. A 42-year-old paraplegic gentleman suffering from a complicated Ischial ulcer was admitted for debridement and closure with a fasciocutaneous rotational flap. Two weeks later, new pressure sores of the popliteal fossae of both his legs had developed. Clinical assessment revealed linear pressure sores in the presence of poorly fitted, tight, thigh-length TED stockings, which had rolled up at the popliteal fossa creating a focal linear compression in the presence of bilateral spastic flexed knees in this paraplegic patient. The TED stockings were immediately discontinued and the pressure sores were managed with regular wound care and dressing change. CONCLUSION: We would like to highlight the complications that could arise amongst paraplegic patients with the widespread use of TED stockings.

Topical diphenylhydantoin sodium can improve healing in a diabetic incisional animal wound model.

OBJECTIVE: Anecdotally, topical application of diphenylhydantoin sodium (DpH) (phenytoin) has been shown to aid wound healing. We previously reported improved healing following topical infiltration of DpH in a healthy animal wound model. This study evaluates its effect on an incisional wound model in diabetic animals. METHOD: Twenty-five male Sprague-Dawley rats were rendered diabetic by a single intraperitoneal injection of streptozotocin. Two caudal and two cephalad wounds were made on the dorsal surface. A polyvinyl alcohol sponge was placed in a subcutaneous pocket created proximal to both cephalad wounds. Each wound was either treated topically with 10mg DpH in a 200microl carrier or an equal volume of the saline vehicle (control) on the day of wounding and days 3 and 6 post-incision. The animals were sacrificed on day 10. The breaking strength of fresh and fixed wounds was determined by tensiometry, and the hydroxyproline content was determined spectrophotometrically. RESULTS: There was a significant overall increase in both fresh (24%) and fixed (18%) wound-breaking strength of the DpH-treated wounds when compared with the controls (p<0.05). This was associated with an increase in collagen synthesis as indicated by the increased hydroxyproline content in the DpH-infiltrated sponges when compared with the controls. CONCLUSION: Our data suggest that topical DpH improves healing in a diabetic wound model. Topical administration of DpH has the potential to accelerate diabetic wound healing and should be evaluated in human diabetic wounds.

Forms of cytochrome P450 in the liver microsome of oxidized frying oil-fed guinea pigs.

The aim of this study is to investigate the influence of oxidized frying oil (OFO) on the induction of individual forms of cytochrome P450 (CYP450) in guinea pigs. The OFO samples were obtained by frying potato chips in soybean oil at 200+/-5 degrees C for 24 h. Sixteen male weaning guinea pigs were fed for 12 wk on a diet which included 15% of either OFO or fresh soybean oil supplemented with 300 ppm ascorbic acid. It was demonstrated that guinea pigs fed with the OFO diet (D300) exhibited inferior growth rates and lower feed efficiency than the control group (F300). The vitamin C contents of plasma, liver, and kidney in the D300 group were lower than those in the F300 group. Further, the thiobarbituric acid-reactive substance content in D300 liver and kidney was higher than that in the F300 equivalent. The liver UDP-glucuronyl-transferase activity in the D300 group was higher than that in the F300 group, and there was no difference in comparing the glutathione-S-transferase activity levels of the two groups. Notably, the total CYP450 content and the NADPH-cytochrome c reductase activity were significantly elevated in the D300 group. The ethoxyresorufin O-deethylase activity, which mainly represents CYP1A1 activity, for the detection of CYP450 isozyme characteristics was elevated more in the D300 than in the F300 group. There was no difference in the pentoxyresorufin O-dealkylase activity, which mainly reflects the CYP2B isozyme, between the two groups. However, the quantity of CYP1A1 isoform determined in the D300 group did not differ from that in the F300 group, as revealed by SDS-PAGE and Western blot testing. Our results demonstrate that the relative enzyme activity to CYP1A1-like activity of the guinea pig hepatic xenobiotic metabolizing enzyme system may be induced by OFO feeding, but more advanced research is needed to identify the predominant form of CYP450 isozyme induced as a result of this condition.

Calcium binding mode of gamma-carboxyglutamic acids in conantokins.

Conantokin-T (con-T) and conantokin-G (con-G) are two highly homologous peptide toxins found in Conus venom. The former is a 21-residue peptide with four gamma-carboxyglutamic acid (Gla) residues (at positions 3, 4, 10 and 14), while the latter is a 17-residue peptide with five gamma-carboxyglutamic acid residues (at positions 3, 4, 7, 10 and 14). Despite the apparent similarity in number and relative positions of the gamma-carboxyglutamic acid residues, (113)Cd-NMR studies indicated a distinct metal binding behavior for con-G and con-T. There appears to be four binding sites in con-G in contrast to one metal binding site in con-T. To elucidate the mode of calcium binding by the gamma-carboxyglutamic acid residues in these conantokins, we designed various analogous peptides with their gamma-carboxyglutamic acid replaced by other amino acid residues. (113)Cd-NMR experiments on conantokin analogues reveal that the major difference in the number of metal binding sites between con-G and con-T is due to the residue at position 7. We also performed molecular simulations to calculate the relative binding free energies of several potential binding sites. Based on our theoretical and experimental results, we propose a 'four-site' binding model for conantokin-G and a 'single-site' binding model for conantokin-T.

Biochemistry and pharmacokinetics of potent non-steroidal cytochrome P450(17alpha) inhibitors.

Two potent non-steroidal inhibitors (CB7645 and CB7661) of human cytochrome P450(17alpha) were tested for in vivo activity in WHT mice. There were no signs of toxicity, but there was no effect on the androgen-dependent organs. The pharmacokinetics and biochemistry of the compounds in mice were investigated. Following i.p. administration of 0.5 mmol/kg of CB7645 and CB7661, peak plasma levels of 13.4 and 3.4 microM, respectively, occurred after 2-4 h, both compounds were cleared rapidly (terminal half-lives 2.7 and 3.3 h, respectively) and neither was detectable at 24 h. CB7645 produced some decrease in plasma testosterone at 4 h, but this was not sustained. When tested in vitro against the WHT testicular enzyme, the CB7645 and CB7661 were competitive inhibitors with K(i) values of 10 and 13 nM, respectively. However, the K(m) for the substrate progesterone was lower at 4.3 nM. These data indicate that, for effective and continuous inhibition of the murine cytochrome P450(17alpha) enzyme, higher peak levels of the compounds would be required, and these levels would need to be maintained throughout the treatment period.

3- and 4-pyridylalkyl adamantanecarboxylates: inhibitors of human cytochrome P450(17 alpha) (17 alpha-hydroxylase/C17,20-lyase). Potential nonsteroidal agents for the treatment of prostatic cancer.

Various 3- and 4-pyridylalkyl 1-adamantanecarboxylates have been synthesized and tested for inhibitory activity toward the 17 alpha-hydroxylase and C17,20-lyase activities of human testicular cytochrome P450(17 alpha). The 4-pyridylalkyl esters were much more inhibitory than their 3-pyridylalkyl counterparts. The most potent was (S)-1-(4-pyridyl)ethyl 1-adamantanecarboxylate (3b; IC50 for lyase, 1.8 nM), whereas the (R)-enantiomer 3a was much less inhibitory (IC50 74 nM). Nearly as potent as 3b was the dimethylated counterpart, the 2-(4-pyridylpropan-2-yl) ester 5 (IC50 2.7 nM), which was also more resistant to degradation by esterases. In contrast to their 4-pyridyl analogs, the enantiomers of the 1-(3-pyridyl)ethyl ester were similarly inhibitory (IC50 for lyase; (R)-isomer 8a 150 nM, (S)-isomer 8b 230 nM). Amides corresponding to the 4-pyridylmethyl ester 1 and the (S)-1-(4-pyridyl)ethyl ester 3b, respectively 11 and 15b, were much less inhibitory than their ester counterparts. On the basis of a combination of inhibitory potency and resistance to esterases, the ester 5 was the best candidate for further development as a potential nonsteroidal inhibitor of cytochrome P450(17 alpha) for the treatment of prostate cancer.

An open non-comparative pilot study with azithromycin in the treatment of non-gonococcal urethritis in the sexually transmitted disease clinics in Hong Kong.

The aim of this study is to find out the efficacy and safety of azithromycin in the treatment of males with uncomplicated non-gonococcal urethritis. It is an open, non-comparative study carried out in the major sexually transmitted disease clinics in Hong Kong. The subjects were 45 male outpatients with clinical symptoms and signs of acute non-gonococcal urethritis. Patients presenting with acute urethritis were examined and non-gonococcal urethritis were examined and non-gonococcal urethritis was daignosed by the positive urethral smear for white blood cells but negative for gonococcus. They were given a single 1 gram oral dose of azithromycin at the clinic. Follow-ups after one and two weeks to examine for cure and adverse events were made. The result showed that 35 out of 42 evaluable patients were cleared of urethritis. Only 2 out of 22 chlamydial antigen positive patients still remained positive at the last visit. Adverse events were not uncommon but all were only mild. We concluded that 1 gram single dose of azithromycin was effective and well tolerated in the treatment of non-gonococcal urethritis in male patients.