Increased accumulation of the glycoxidation product N(epsilon)-(carboxymethyl)lysine in human tissues in diabetes and aging

N(epsilon)-(Carboxymethyl)lysine (CML), a major product of oxidative modification of glycated proteins, has been suggested to represent a general marker of oxidative stress and long-term damage to proteins in aging, atherosclerosis, and diabetes. To investigate the occurrence and distribution of CML in humans an antiserum specifically recognizing protein-bound CML was generated. The oxidative formation of CML from glycated proteins was reduced by lipoic acid, aminoguanidine, superoxide dismutase, catalase, and particularly vitamin E and desferrioxamine. Immunolocalization of CML in skin, lung, heart, kidney, intestine, intervertebral discs, and particularly in arteries provided evidence for an age-dependent increase in CML accumulation in distinct locations, and acceleration of this process in diabetes. Intense staining of the arterial wall and particularly the elastic membrane was found. High levels of CML modification were observed within atherosclerotic plaques and in foam cells. The preferential location of CML immunoreactivity in lesions may indicate the contribution of glycoxidation to the processes occurring in diabetes and aging. Additionally, we found increased CML content in serum proteins in diabetic patients. The strong dependence of CML formation on oxidative conditions together with the increased occurrence of CML in diabetic serum and tissue proteins suggest a role for CML as endogenous biomarker for oxidative damage.     

Prostate specific antigen in the expressed prostatic fluid of men with benign prostatic hyperplasia and prostate carcinoma

PURPOSE: We tested the hypothesis that the histochemically demonstrated prostate specific antigen (PSA) content of prostate carcinoma cells does not necessarily reflect PSA production and secretion by evaluating expressed prostatic fluid. MATERIALS AND METHODS: Expressed prostatic fluid and serum from 152 men with clinical benign prostatic hypertrophy (BPH), 132 with histologically proved BPH and 46 with prostate carcinoma were analyzed with the Hybritech PSA assay. RESULTS: Expressed prostatic fluid PSA levels from carcinoma patients (median 1.70 mg./ml., mean 2.25) were significantly higher than in the histologically proved BPH group (median 1.28 mg./ml., mean 1.42, p < 0.05). CONCLUSIONS: PSA concentration is increased in the expressed prostatic fluid of prostates of men with carcinoma compared to those with histological BPH. This finding may be a functional manifestation of a field change or paracrine effects within the prostate.     

THE FLUID MECHANICS of COOKIE DOUGH EXTRUDERS

A model of the fluid mechanics of two roll cookie dough extruders, such as used for wire cut and rout cookies, is presented. the model uses the lubrication approximation to obtain a first estimate for the predictive equations for extruder capacity, power consumption, total shear strain, and forces developed by the rolls. These equations are used to understand the importance of various design and operational parameters.     

Brain attack. Acute therapeutic interventions. Free radical scavengers and antioxidants

This study used tests of content memory (item recognition of words and abstract designs), context memory (order recognition of verbal and nonverbal items), and working memory (recognition at a short retention interval) to examine patterns of performance in 27 schizophrenic patients, 52 chronic alcoholic patients, and 66 healthy control participants. When performance was age- and IQ-adjusted the schizophrenia group was significantly impaired in item and order recognition of verbal and nonverbal material; the alcoholic group was impaired only in order recognition for both material types. Item- and order-recognition deficits in the schizophrenia group were greatest at the shortest retention intervals, a pattern previously observed in patients with Parkinson's disease, suggesting a prominence of a working memory deficit in schizophrenia.     

Substantial narrowing of the Niemann-Pick C candidate interval by yeast artificial chromosome complementation

Niemann-Pick disease type C (NP-C) is an autosomal recessive lipidosis linked to chromosome 18q11-12, characterized by lysosomal accumulation of unesterified cholesterol and delayed induction of cholesterol-mediated homeostatic responses. This cellular phenotype is identifiable cytologically by filipin staining and biochemically by measurement of low-density lipoprotein-derived cholesterol esterification. The mutant Chinese hamster ovary cell line (CT60), which displays the NP-C cellular phenotype, was used as the recipient for a complementation assay after somatic cell fusions with normal and NP-C murine cells suggested that this Chinese hamster ovary cell line carries an alteration(s) in the hamster homolog(s) of NP-C. To narrow rapidly the candidate interval for NP-C, three overlapping yeast artificial chromosomes (YACs) spanning the 1 centimorgan human NP-C interval were introduced stably into CT60 cells and analyzed for correction of the cellular phenotype. Only YAC 911D5 complemented the NP-C phenotype, as evidenced by cytological and biochemical analyses, whereas no complementation was obtained from the other two YACs within the interval or from a YAC derived from chromosome 7. Fluorescent in situ hybridization indicated that YAC 911D5 was integrated at a single site per CT60 genome. These data substantially narrow the NP-C critical interval and should greatly simplify the identification of the gene responsible in mouse and man. This is the first demonstration of YAC complementation as a valuable adjunct strategy for positional cloning of a human gene.     

The structure of glycogen phosphorylase b with an alkyldihydropyridine-dicarboxylic acid compound, a novel and potent inhibitor

BACKGROUND: In muscle and liver, glycogen concentrations are regulated by the reciprocal activities of glycogen phosphorylase (GP) and glycogen synthase. An alkyl-dihydropyridine-dicarboxylic acid has been found to be a potent inhibitor of GP, and as such has potential to contribute to the regulation of glycogen metabolism in the non-insulin-dependent diabetes diseased state. The inhibitor has no structural similarity to the natural regulators of GP. We have carried out structural studies in order to elucidate the mechanism of inhibition. RESULTS: Kinetic studies with rabbit muscle glycogen phosphorylase b (GPb) show that the compound (-)(S)-3-isopropyl 4-(2-chlorophenyl)-1,4-dihydro-1-ethyl-2-methyl-pyridine-3,5, 6-tricarboxylate (Bay W1807) has a Ki = 1.6 nM and is a competitive inhibitor with respect to AMP. The structure of the cocrystallised GPb-W1807 complex has been determined at 100K to 2.3 A resolution and refined to an R factor of 0.198 (Rfree = 0.287). W1807 binds at the GPb allosteric effector site, the site which binds AMP, glucose-6-phosphate and a number of other phosphorylated ligands, and induces conformational changes that are characteristic of those observed with the naturally occurring allosteric inhibitor, glucose-6-phosphate. The dihydropyridine-5,6-dicarboxylate groups mimic the phosphate group of ligands that bind to the allosteric site and contact three arginine residues. CONCLUSIONS: The high affinity of W1807 for GP appears to arise from the numerous nonpolar interactions made between the ligand and the protein. Its potency as an inhibitor results from the induced conformational changes that lock the enzyme in a conformation known as the T' state. Allosteric enzymes, such as GP, offer a new strategy for structure-based drug design in which the allosteric site can be exploited. The results reported here may have important implications in the design of new therapeutic compounds.     

Randomized comparison of cisplatin and etoposide and either bleomycin or ifosfamide in treatment of advanced disseminated germ cell tumors: an Eastern Cooperative Oncology Group, Southwest Oncology Group, and Cancer and Leukemia Group B Study

PURPOSE: To compare standard therapy with bleomycin, etoposide, and cisplatin (BEP) to experimental therapy with etoposide, ifosfamide, and cisplatin (VIP) as primary treatment of men with advanced, disseminated germ cell tumors. PATIENTS AND METHODS: A total of 304 men with advanced disseminated germ cell tumors were randomly allocated to receive four courses of BEP or VIP. Two hundred ninety-nine patients were assessable for toxicity and 286 were assessable for response. Complete response rates, favorable response (complete remission, surgical free of disease, continuous partial remission for 2+ years), time to treatment failure, and overall survival were assessed. RESULTS: Overall complete remission rate (VIP, 37%; BEP, 31%), favorable response rate (VIP, 63%; BEP, 60%), failure-free at 2 years (VIP, 64%; BEP, 60%), and 2-year overall survival (VIP, 74%; BEP, 71%) were not significantly different between the two treatments. Grade 3 or worse toxicity, particularly hematologic and genitourinary toxicity, was significantly more common in patients who received VIP. CONCLUSION: BEP and VIP produce comparable favorable response rate and survival in patients with poor-risk germ cell tumors. The substitution of ifosfamide for bleomycin, however, was associated with significantly greater toxicity. Four courses of BEP remain the standard treatment for advanced disseminated germ cell tumors.