A novel strategy for NQO1 (NAD(P)H:quinone oxidoreductase, EC 1.6.99.2) mediated therapy of bladder cancer based on the pharmacological properties of EO9.

The indolequinone EO9 demonstrated good preclinical activity but failed to show clinical efficacy against a range of tumours following intravenous drug administration. A significant factor in EO9's failure in the clinic has been attributed to its rapid pharmacokinetic elimination resulting in poor drug delivery to tumours. Intravesical administration of EO9 would circumvent the problem of drug delivery to tumours and the principal objective of this study is to determine whether or not bladder tumours have elevated levels of the enzyme NQO1 (NAD(P)H:quinone oxidoreductase) which plays a key role in activating EO9 under aerobic conditions. Elevated NQO1 levels in human bladder tumour tissue exist in a subset of patients as measured by both immunohistochemical and enzymatic assays. In a panel of human tumour cell lines, EO9 is selectively toxic towards NQO1 rich cell lines under aerobic conditions and potency can be enhanced by reducing extracellular pH. These studies suggest that a subset of bladder cancer patients exist whose tumours possess the appropriate biochemical machinery required to activate EO9. Administration of EO9 in an acidic vehicle could be employed to reduce possible systemic toxicity as any drug absorbed into the blood stream would become relatively inactive due to an increase in pH.

A study of serum lipid profile part-1: Establishment of normal reference values of serum lipid levels in healthy vegetarian population of Gujarat.

Fasting samples of 1329 apparently healthy vegetarian Gujarati population were tested for total cholesterol, triglycerides and three major fractions of lipoproteins, i.e. high density lipoproteins, low density lipoproteins and very low density lipoproteins. All the values showed marked increase with the age. Except for serum triglycerides, values differ in males and females in the age group of above 45 years. Compared to Northern Indian population low density lipoprotein and high density lipoprotein values were higher, but values of triglycerides and very low density lipoproteins were lower. There is no significant difference in total cholesterol values. Compared to Southern Indian population low density lipoprotein and very low density lipoprotein values were higher but values of triglycerides, total cholesterol and high density lipoprotein were lower. All serum lipid values were significantly lower than the Westem population. The range of values for both the sexes is presented for different age groups.

Laser prostatectomy: our initial experience of a technique in evolution.

Recently great interest has been generated in alternatives to transurethral resection for benign prostatic hyperplasia. Lasers are currently being assessed, but marketing has for the moment outstripped basic science. A cystoscopic approach was used delivering Nd:YAG or KTP laser energy via forward and sidefiring fibers and contact tip devices in 51 patients. The sidefiring device is intended to coagulate a volume of prostate that subsequently sloughs, leaving a cavity. Treatment of the apical and middle lobe tissue using this technique was unsatisfactory. A further disadvantage was the interval between treatment and improvement in urine flow, which was approximately 6 weeks. The use of temporary prostatic stents has helped to overcome this delay in treatment effect. Encouraging early results have been achieved using forward-firing fibers to treat apical and middle lobe tissue. The use of contact tip devices to perform bloodless prostatotomies in combination with sidefire or bare fiber has also proved useful. Laser prostatectomy is an exciting field with considerable potential but remains in the developmental stage.

Nonvisual laser lithotripsy aided by plasma spectral analysis: viability study and clinical application.

Nonvisual laser lithotripsy implies laser fragmentation without the aid of endoscopic or direct vision. Using the laser delivery fiber for retrograde transmission of plasma spectrum and its analysis on an optical multichannel analyzer, we designed a project with the objective of identification and fragmentation of calculi by continuous analysis of the plasma feedback spectrum. We were successful in achieving the objectives in the in vitro and ex vivo studies. In the in vivo studies we successfully recorded the plasma spectrum of the stones from inside the ureter and monitored the process of fragmentation with the laser. We have been able to identify the problems for its clinical application. We conclude that by monitoring the feedback spectrum of plasma emission, nonvisual laser lithotripsy is reliable and safe, and can be used successfully in patients with some modifications. Its development is not to replace established endoscopic lithotripsy procedures but rather as an additional armament for the urologist in special situations. Also, the technique can be further exploited for a variety of clinical uses.

Production and purification of prostromelysin and procollagenase from IL-1 beta-stimulated human gingival fibroblasts.

Conditions were established to stimulate human gingival fibroblast explant cultures to synthesize milligram quantities of the metalloproteinase proenzymes, prostromelysin and procollagenase. To stimulate enzyme production, cells were treated with 1 nM recombinant human IL-1 beta for approximately 7 days under serum free conditions. Using a combination of rapid column chromatography steps, approximately 10 milligrams of prostromelysin and 5 milligrams of procollagenase were purified from 1 liter of conditioned media. Prostromelysin electrophoresed as a doublet with molecular weights of 55,57 kD, whereas, procollagenase migrated with slightly lower molecular weights of 52, 54 kD. Both proenzymes were treated with trypsin or aminophenylmercuric acetate to generate active species. The molecular weights of the active enzymes were approximately 10 kD smaller than the proenzymes. Active enzymes were inhibited by metal chelators and the natural metalloproteinase inhibitor, tissue inhibitor of metalloproteinase (TIMP), but not by the serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF). Activated stromelysin degraded a number of substrates including transferrin, proteoglycan monomer, proteoglycan aggregated with hyaluronic acid, and substance P. By contrast, collagenase degraded interstitial type I collagen and the peptide thioester, Ac-Pro-Leu-Gly-SCH(iBu)Co-Leu-GlyOEt. Identity of both enzymes were confirmed by amino-terminal protein sequence analysis as well as by immunoblot analysis using monoclonal antibodies.