ω-Phthalimidoalkyl Aryl Ureas as Potent and Selective Inhibitors of Cholesterol Esterase.

Cholesterol esterase (CEase), a serine hydrolase thought to be involved in atherogenesis and thus coronary heart disease, is considered as a target for inhibitor development. We investigated recombinant human and murine CEases with a new fluorometric assay in a structure-activity relationship study of a small library of ω-phthalimidoalkyl aryl ureas. The urea motif with an attached 3,5-bis(trifluoromethyl)phenyl group and the aromatic character of the ω-phthalimide residue were most important for inhibitory activity. In addition, an alkyl chain composed of three or four methylene groups, connecting the urea and phthalimide moieties, was found to be an optimal spacer for inhibitors. The so-optimized compounds 2 [1-(3,5-bis(trifluoromethyl)phenyl)-3-(3-(1,3-dioxoisoindolin-2-yl)propyl)urea] and 21 [1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-(1,3-dioxoisoindolin-2-yl)butyl)urea] exhibited dissociation constants (Ki ) of 1-19 µm on the two CEases and showed either a competitive (2 on the human enzyme and 21 on the murine enzyme) or a noncompetitive mode of inhibition. Two related serine hydrolases-monoacylglycerol lipase and fatty acid amide hydrolase-were inhibited by ω-phthalimidoalkyl aryl ureas to a lesser extent.

Flare-up reactions in severe drug hypersensitivity: infection or ongoing T-cell hyperresponsiveness.

"Flare-up" reactions are late manifestations of severe T-cell-mediated drug hypersensitivity reactions. Management is anti-inflammatory treatment and avoiding unnecessary medicines. Symptoms like fever, lymph node swelling, and blood count abnormalities may lead to confusion with bacterial infections. For prompt recognition it is important to keep the differential diagnosis in mind.

Severe postoperative wound healing disturbance in a patient with alpha-1-antitrypsin deficiency: the impact of augmentation therapy.

Wound healing disturbance is a common complication following surgery, but the underlying cause sometimes remains elusive. A 50-year-old Caucasian male developed an initially misunderstood severe wound healing disturbance following colon and abdominal wall surgery. An untreated alpha-1-antitrypsin (AAT) deficiency in the patient's medical history, known since 20 years and clinically apparent as a mild to moderate chronic obstructive pulmonary disease, was eventually found to be at its origin. Further clinical work-up showed AAT serum levels below 30% of the lower reference value; phenotype testing showed a ZZ phenotype and a biopsy taken from the wound area showed the characteristic, disease-related histological pattern of necrotising panniculitits. Augmentation therapy with plasma AAT was initiated and within a few weeks, rapid and adequate would healing was observed. AAT deficiency is an uncommon but clinically significant, possible cause of wound healing disturbances. An augmentation therapy ought to be considered in affected patients during the perioperative period.

Cytotoxic effects of camptothecin and cisplatin combined with tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) in a model of primary culture of non-small cell lung cancer.

BACKGROUND: The cytokine tumor-necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) has been shown to preferentially induce apoptosis in cancer cells. A previous study of our group demonstrated that non-small cell lung cancer cell lines can be sensitized to Apo2L/TRAIL-induced apoptosis by chemotherapeutic agents. The aim of the present study was the evaluation of these results in a model of primary culture of non-small cell lung cancer. MATERIALS AND METHODS: Lung cancer tissue and normal lung tissue obtained from 8 patients who underwent operation were cultured and treated with Apo2L/TRAIL alone and in combination with cisplatin and the topoisomerase I inhibitor camptothecin for different periods. Metabolic activity of the tissue was measured by alamar blue. Markers for apoptosis were determined by immunohistochemistry and Western blot. Expression of Apo2L/TRAIL receptors in primary lung cancer and normal lung tissue was evaluated by semi-quantitative RT-PCR. Statistics were performed using nonparametric repeated measures Anova with Dunnett's correction. RESULTS: Treatment with cisplatin, camptothecin and the combination of camptothecin and Apo2L/TRAIL demonstrated significant reduction of metabolic activity in tumor and normal lung tissue. In addition, the combination of camptothecin plus Apo2L/TRAIL revealed greater cytotoxic activity in cancer tissue compared with normal lung tissue. Importantly, no toxic activity of Apo2L/TRAIL alone in normal lung tissue was observed. CONCLUSION: Our results obtained in a model of primary culture of lung cancer suggest that the combination of Apo2L/TRAIL and camptothecin might present an effective strategy for the treatment of non-small cell lung cancer.

Suramin induces and enhances apoptosis in a model of hyperoxia-induced oligodendrocyte injury.

Recent evidence suggests oxygen as a powerful trigger for cell death in the immature white matter, leading to periventricular leukomalacia (PVL) as a cause of adverse neurological outcome in survivors of preterm birth. This oligodendrocyte (OL) death is associated with oxidative stress, upregulation of apoptotic signaling factors (i.e., Fas, caspase-3) and decreased amounts of neurotrophins. In search of neuroprotective strategies we investigated whether the polysulfonated urea derivative suramin, recently identified as a potent inhibitor of Fas signaling, affords neuroprotection in an in vitro model of hyperoxia-induced injury to immature oligodendrocytes. Immature OLs (OLN-93) were subjected to 80% hyperoxia (48 h) in the presence or absence of suramin (0, 30, 60, 120 microM). Cell death was assessed by flow cytometry (Annexin V, caspase-3 activity assay) and immunohistochemistry for activated caspase-3. Immunoblotting for the death receptor Fas, cleaved caspase-8 and the phosphorylated isoform of the serine-threonin kinase Akt (pAkt) was performed. Suramin lead to OL apoptosis and potentiated hyperoxia-induced injury in a dose-dependent manner. Immunoblotting revealed increased Fas and caspase-8 expression by suramin treatment. This effect was significantly enhanced when suramin was combined with hyperoxia. Furthermore, pAkt levels decreased following suramin exposure, indicating interference with neurotrophin-dependent growth factor signaling. These data indicate that suramin causes apoptotic cell death and aggravates hyperoxia-induced cell death in immature OLs. Its mechanism of action includes an increase of previously described hyperoxia-induced expression of pro-apoptotic factors and deprivation of growth factor dependent signaling components.

Estradiol attenuates hyperoxia-induced cell death in the developing white matter.

OBJECTIVE: Periventricular leukomalacia is the predominant type of brain injury in preterm infants underlying the development of cerebral palsy. Periventricular leukomalacia has its peak incidence at 23 to 32 weeks postconceptional age characterized by extensive oligodendrocyte migration and maturation. Oxygen toxicity has been identified as a possible contributing factor to the pathogenesis of cerebral palsy in survivors of preterm birth. 17beta-estradiol (E2) is important for the development and function of the central nervous system. Furthermore, neuroprotective properties have been attributed to estrogens. We examined the effect of E2 on hyperoxia-induced cell death in the developing white matter in the rat brain. METHODS: Six-day-old (P6) rat pups, the immature oligodendroglial cell line (OLN-93), and primary oligodendrocyte cultures were subjected to 80% O(2) in the presence or absence of E2 (600 microg/kg intraperitoneally in vivo, 10(-6)-10(-10)M in vitro). Cell counts and lactate dehydrogenase assay were used to assess cell survival. Immunoblot analysis was used for detection of estrogen receptor expression and investigation of apoptotic signaling pathways. White matter injury was assessed by myelin basic protein immunocytochemistry at P11. RESULTS: E2 produced significant dose-dependent protection against oxygen-induced apoptotic cell death in primary oligodendrocytes. Treatment with E2 prevented hyperoxia-induced proapoptotic Fas-upregulation and caspase-3 activation. Finally, E2 antagonized hyperoxia-induced inactivation of extracellular signal-regulated kinase 1 and 2 and Akt, key kinases of the mitogen-activated protein kinase and phosphatidylinositol 3-kinase cell survival promoting pathways, respectively. Loss of myelin basic protein labeling was seen in P11 pups after oxygen exposure, and E2 attenuated this injury. INTERPRETATION: These results suggest a possible role for estrogens in the prevention of neonatal oxygen-induced white matter injury.

Maturation-dependent oligodendrocyte apoptosis caused by hyperoxia.

In the immature human brain, periventricular leukomalacia (PVL) is the predominant white matter injury underlying the development of cerebral palsy. PVL has its peak incidence during a well-defined period in human brain development (23-32 weeks postconceptional age) characterized by extensive oligodendrocyte migration and maturation. We hypothesized that the dramatic rise of oxygen tissue tension associated with mammalian birth and additional oxygen exposure of the preterm infant during intensive care may be harmful to immature oligodendrocytes (OLs). We therefore investigated the effects of hyperoxia on rat oligodendroglia cells in vitro and in vivo. Immature OLs (OLN-93), their progenitors [preoligodendrocytes (pre-OL)], and mature OLs were subjected to 80% hyperoxia (24-96 hr). Flow cytometry was used to assess cell death. Cell viability was measured by metabolism of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT). In addition, 6-day-old rat pups were subjected to 80% oxygen (24 hr) and then sacrificed, and their brains were processed for immunfluorescence staining. Apoptosis was detected at various stages (annexin-V, activated caspase-3) after 24-48 hr of incubation in 80% oxygen in pre- and immature OLs. Mature OLs were resistant to oxygen exposure. These results were confirmed by MTT assay. This cell death was blocked by administration of the pan-caspase inhibitor zVAD-fmk. Degeneration of OLs was confirmed in 7-day-old rat brains by positive staining for activated caspase-3. Hyperoxia triggers maturation-dependent apoptosis in immature and pre-OLs and involves caspase activation. This mechanism may be relevant to the white matter injury observed in infants born preterm.