Preparation, isolation, analysis, and characterization of 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid: a metabolite of 3-hydroxybenzo[a]pyrene with potentially high carcinogenic activity

The aglycone, 3-hydroxybenzo[a]pyrene, was metabolized to 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid in the presence of uridine 5'-diphosphoglucuronic acid and rabbit liver microsomes. The course of the biosynthetic reaction was followed by fluorimetry and reverse-phase, paired-ion high pressure liquid chromatography (HPLC). Also, the HPLC system was used to analyze for glucuronide and 3-hydroxybenzo[a]pyrene during the isolation procedure. The existence of a glucuronide of 3-hydroxybenzo[a]pyrene was determined by radiotracer and enzymic techniques, utilizing the HPLC system. Field desorption and direct inlet mass spectral techniques were used to characterize the 3-hydroxybenzo[a]pyrene glucuronide.     

Nonrandomness in protein sequences: evidence for a physically driven stage of evolution?

The sequences, or primary structures, of existing biopolymers--in particular, proteins--are believed to be a product of evolution. Are the sequences random? If not, what is the character of this nonrandomness? To explore the statistics of protein sequences, we use the idea of mapping the sequence onto the trajectory of a random walk, originally proposed by Peng et al. [Peng, C.-K., Buldyrev, S. V., Goldberger, A. L., Havlin, S., Sciortino, F., Simons, M. & Stanley, H. E. (1992) Nature (London) 356, 168-170] in their analysis of DNA sequences. Using three different mappings, corresponding to three basic physical interactions between amino acids, we found pronounced deviations from pure randomness, and these deviations seem directed toward minimization of the energy of the three-dimensional structure. We consider this result as evidence for a physically driven stage of evolution.     

Study of correlations in DNA sequences

We present a method for unified statistical analysis of short and long range correlations between various nucleotides in genomic DNA strands. The approach is based on the mutual study of Fourier structure factor spectra and pair correlation functions. The analysis of cross correlations in the different ranges of structural spectra permits identification of the main sources of correlations, namely, the coherent point mutations, coincident periodicities or large scale density variations. The technique for assessment of structural coupling between various genes in the genome is also described.     

Ordering of polymorphic markers in the chromosome region 3p21

Starting from five markers, with a well-defined order from distal to proximal 3p21, nine other markers could be inserted in this 3p21 map. Five were precisely mapped genetically. The other markers were ordered by FISH and/or deletion hybrid mapping. The overall 3p21 order from distal to proximal is as follows: D3S1298-D3S1260-(D3S966, D3S1448 (= D3S1449)-D3S1029-D3S32-D3S643-D3F15S2 -D3S2968-D3S1235-D3S1289-D3S1447-D3S1295.     

Exploratory factor analysis of MRI brain structure measures in schizophrenia

Much of the literature shows various regional structural brain abnormalities in schizophrenia, but the complexity and variability of brain makes it difficult to determine how these regions are related. Statistical methods which estimate factors underlying patterns of covariance have not been widely used, but could be useful for analyzing such complex data. We applied exploratory and confirmatory factor analysis procedures to specific cortical and subcortical regional brain volume measures from MRI data in 60 normal and 44 schizophrenic subjects. Basal ganglia, heteromodal cortical gray, and medial temporal lobe factors were present in both the normal and the schizophrenia groups. The factor structure observed in the normal group showed a high degree of bilateral symmetry which is present but disrupted in the schizophrenia group. In the bilateral data, the disruption is most pronounced with medial and lateral temporal lobe structures including entorhinal cortex and anterior and posterior superior temporal gyri. There was a significant correlation between the basal ganglia factor and the heteromodal cortical gray factor in the normal group that was not present in the schizophrenia group. In the unilateral data, left posterior superior temporal gyrus did not load onto any factor in the schizophrenia group. Confirmatory factor analyses showed significant differences between the two groups in factor structure. A number of specific brain regions are affected in schizophrenia, and structural relationships between groups of regions also are abnormal. The results suggest that heteromodal dorsolateral prefrontal and superior temporal cortical gray regions are structurally related, whereas inferior parietal cortical gray is less so. These results should be viewed as preliminary as the ratio of parameters to subjects was relatively low, and replication is needed. However, the results demonstrate the potential utility of latent structure methods such as factor analysis in study of complex relationships in neuropsychiatric data.     

Oral ondansetron for the control of cisplatin-induced delayed emesis: a large, multicenter, double-blind, randomized comparative trial of ondansetron versus placebo

PURPOSE: To investigate the efficacy and safety of oral ondansetron in the control of cisplatin-induced delayed emesis in patients who do not require rescue antiemetic therapy for acute emesis. PATIENTS AND METHODS: Five hundred thirty-eight chemotherapy-naive patients who received cisplatin chemotherapy (> or = 70 mg/m2), and who were not rescued for acute emesis, were eligible to be randomized to receive one of the three oral regimens to control delayed emesis. Group I received placebo on days 2 to 6; group II received ondansetron 8 mg twice daily on days 2 and 3 and placebo on days 4 to 6; group III received ondansetron 8 mg twice daily on days 2 to 6. All patients received intravenous ondansetron (0.15 mg/kg every 4 hours for three doses) for the control of acute emesis on day 1. The number of emetic episodes on days 2 and 3 combined (days 2/3, when incidence and severity of delayed emesis were expected to be greatest) was considered the primary measure of efficacy. RESULTS: Patients who received odansetron had significantly fewer emetic episodes on days 2/3, 4, and 5 than those who received placebo (P < or = .002 on each day). Additionally, significantly more patients who received ondansetron had a complete plus major response (C+MR; < or = two two emetic episodes) than those who received placebo on days 2/3 (56% v 37%, P = .001), 4 (94% v 85%, P = .005), and 5 (98% v 88%, P = .006). Patients who received ondansetron had significantly less nausea on day 2/3 when day-1 nausea was used as the baseline score (P = .025). Patients who received ondansetron also had significantly less nausea on day 4 (P = .042) and the results approached significance on day 5 (P = .066). CONCLUSION: Oral ondansetron had a significant effect in the control of cisplatin-induced delayed emesis and nausea in patients who had not required rescue antiemetics during the acute emesis period. The control of delayed nausea and vomiting was most notable in the immediate 2 days following cisplatin administration, with the clinical difference narrowing between the two treatment arms on subsequent days.