Chronic treatment with sulfhydryl angiotensin-converting enzyme inhibitors reduce susceptibility of plasma LDL to in vitro oxidation, formation of oxidation-specific epitopes in the arterial wall, and atherogenesis in apolipoprotein E knockout mice

The effects of chronic treatment with the new sulfhydryl angiotensin-converting enzyme (ACE)-inhibitor, zofenopril, in comparison with the classical sulfhydryl ACE-inhibitor captopril or enalapril or placebo on the development of atherosclerosis were determined in apolipoprotein-E knockout (apoE(-/-)) mice. Groups of 2-month-old male mice received either placebo (N=10), 0.05 mg/kg/day of zofenopril (N=10), 1 mg/kg/day of zofenopril (N=10), 5 mg/kg/day of captopril (N=10) or 0.5 mg/kg/day of enalapril (N=8). After 29 weeks of treatment, computer-assisted imaging analysis revealed that zofenopril reduced the aortic cumulative lesion area by 78% at 0.05 mg/kg/day and by 89% at 1 mg/ml/day of zofenopril compared to that of the placebo (P<0.0001). Captopril reduced by 52% aortic lesions compared to placebo (P<0.01 vs. placebo; P<0.05 vs. zofenopril at both doses). Enalapril did not reduce aortic lesions. Furthermore, 0.05 mg/kg/day of zofenopril reduced susceptibility of plasma LDL to in vitro oxidation compared to captopril, enalapril or placebo, as shown by significant reduction of malondialdehyde content (P<0.001 vs. placebo or enalapril; P<0.05 vs. captopril), as well as by the prolongation of lag-time (P<0.01 vs. placebo or enalapril P<0.05 vs. captopril). More importantly, mice treated with 1 mg/ml/day of zofenopril had a significant decrease in the intimal immunohistochemical presence of oxidation-specific epitopes on oxLDL (NA59 monoclonal antibody, P<0.01), macrophages derived foam cells (F4/80 monoclonal antibody, P<0.05) and native LDL (NP monoclonal antibody, P<0.01) compared to placebo, captopril or enalapril. Thus, chronic treatment with the new sulfhydryl ACE-inhibitor zofenopril has antiatherosclerotic and antioxidant effects in the arterial wall of hypercholesterolemic apoE(-/-) mice. This protection was significantly higher than that reached with captopril and at lower doses of the drug. Treatment with 0.5 mg/kg/day of enalapril did not provide any protective effect.

[Medical treatment of cystinuria: evaluation of long-term results in 30 patients]

OBJECTIVE

Because urinary hyper-excretion of cystine is permanent in homozygous cystinuric patients, stone recurrence is frequent and may alter renal function. Identification of factors predictive of success of medical treatment (no further urological procedure required) is therefore needed to improve patient management.

PATIENTS AND METHODS

Thirty adult patients with homozygous cystinuria and urolithiasis were referred to the nephrology department of the Necker Hospital from 1963 to 1999, with a mean follow-up of medical therapy of 10.5 +/- 8.4 years. The basal treatment schedule was hyperdiuresis and alkalinization with thiol derivative (D-penicillamine or tiopronine) added when needed.

RESULTS

Overall incidence of urological procedures decreased from 0.33/pt-year in the pretherapeutic period to 0.15 on treatment (p < 0.01), a 55% reduction. Sixteen patients (53%) did not require any urological procedure during follow-up. The only significant difference between those patients and the other 14 in whom medical therapy failed was the daily urine volume (3.2 l/day in the former compared with 2.4 l/day in the latter, p < 0.001).

CONCLUSION

Regular medical therapy was able to stop stone disease activity in the long term in more than half of the patients. Sustained hyperdiuresis, with a daily urine volume > 3 liters, appears as a major factor of therapeutic success, even in patients treated with thiols.

Activated lansoprazole inhibits cancer cell adhesion to extracellular matrix components

Integrins play an important role in tumor dissemination. The purpose of this study was to examine whether a SH-reactive reagent inhibits the adhesion of the human pancreatic cancer cell line AsPC-1 to extracellular matrix components. Activated lansoprazole (AG-2000) was used as the SH-reactive reagent because this compound is known to react with SH groups but does not permeate the cell membrane. The effect of AG-2000 on the adhesion of AsPC-1 cells to matrix was examined, using both an in vitro adhesion assay and an in vivo nude mouse xenograft model of peritoneal implantation. In the in vitro adhesion assay, a 60-min exposure of AsPC-1 cells to AG-2000 resulted in a dose-dependent inhibition of AsPC-1 cell adhesion to laminin, fibronectin and type IV collagen, although AG-2000 did not affect the viability of AsPC-1 cells by MTT assay. In the in vivo assessment of AsPC-1 cell implantation, the AsPC-1 cells were initially preincubated with AG-2000 for 60 min to ensure adequate exposure of the AsPC-1 cells to AG-2000 before intraperitoneal injection. AG-2000 significantly inhibited the peritoneal implantation of the AsPC-1 cells in nude mice. These findings suggest that a short exposure of cancer cells to AG-2000 can inhibit cancer cell adhesion to extracellular matrix components.

NMDA receptor redox sites: are they targets for selective neuronal protection?

NMDA receptors play a central role in neuronal plasticity and in several pathological situations. Transient activation of this receptor triggers long-term potentiation, whereas sustained activation leads to cell death. Evidence for control of this activity by a redox site in cell cultures, brain tissues and in recombinant NMDA receptors are discussed by Henri Gozlan and Yehezkel Ben-Ari. The characteristics of this modulation and the consequences of redox state modifications on NMDA-mediated events are examined in vitro under physiological and pathological conditions. Since metabolic disorders enhance NMDA receptor function, the redox site could constitute a new target for selectively preventing in vivo the deleterious consequences of overactivation without blocking neuronal plasticity mediated by NMDA receptors.

The antimetastatic and tumor growth retarding effects of sulfur containing analogs of nicotinamide

Several sulfur containing 5- and 6-membered heterocyclic carboxylic acids (or esters) were shown to decrease the number of pulmonary metastases in C57BL/6 mice implanted with Lewis lung carcinoma. The numbers of such metastatic nodules were reduced more than 5-fold. In addition, these compounds, which could be viewed as analogs of nicotinamide, were shown to inhibit the growth rate of the primary implanted tumor by about 50%.

Synergistic denaturant therapy--a general strategy for treatment of solid malignancies

"Synergistic denaturant therapy" is defined as the acute disruption of tumor cell structure by concurrent application of "denaturant" modalities such as hyperthermia, tumor-specific acidification, hypoenergia, ischemia, sulphydryl blockade, free-radical generation, detergents, and chemical denaturants (e.g. DMSO). Possible techniques for effective and tumor-specific clinical application of these modalities are discussed, and experimental investigations of their use in cancer therapy, alone or in synergistic combinations, are cited. Various of these modalities may also be used to potentiate the efficacy and specificity of traditional anti-mitotic therapies. Numerous therapeutic advantages are offered by a "synergistic denaturant" approach.

Inhibition of DNA polymerase from L1210 murine leukemia by a sulfhydryl reagent from agaricus bisporus

The 490 quinone, a natural sulfhydryl-arylating reagent from the mushroom, Agaricus bisporus, markedly inhibited L1210 murine leukemia DNA polymerase alpha while resulting in little inhibition of DNA polymerase beta from this source. This quinone was more strongly inhibitory than p-chloromercuri-benzoate or N-ethylmaleimide and was less readily neutralized by sulfhydryl-containing molecules such as dithioerythritol. Preliminary experiments indicate that DNA protects DNA polymerase alpha from inhibition by the 490 quinone. The inhibition of DNA synthesis by quinone 490 may contribute significantly to the cytotoxicity of this compound and to the potential of gamma-L-glutaminyl-4-hydroxybenzene as an antitumor agent.