A diagnosis of prostate cancer and pursuit of active surveillance is not followed by weight loss: potential for a teachable moment.

BACKGROUND: Obesity is a risk factor for incident prostate cancer (PC) as well as risk of disease progression and mortality. We hypothesized that men diagnosed with lower-risk PC and who elected active surveillance (AS) for their cancer management would likely initiate lifestyle changes that lead to weight loss. METHODS: Patients were enrolled in the Prostate Active Surveillance Study (PASS), a multicenter prospective biomarker discovery and validation study of men who have chosen AS for their PC. Data from 442 men diagnosed with PC within 1 year of study entry who completed a standard of care 12-month follow-up visit were analyzed. We examined the change in weight and body mass index (BMI) over the first year of study participation. RESULTS: After 1 year on AS, 7.5% (33/442) of patients had lost 5% or more of their on-study weight. The proportion of men who lost 5% or more weight was similar across categories of baseline BMI: normal/underweight (8%), overweight (6%) and obese (10%, χ2 test P=0.44). The results were similar for patients enrolled in the study 1 year or 6 months after diagnosis. By contrast, after 1 year, 7.7% (34/442) of patients had gained >5% of their weight. CONCLUSIONS: Only 7.5% of men with low-risk PC enrolled in AS lost a modest (⩾5%) amount of weight after diagnosis. Given that obesity is related to PC progression and mortality, targeted lifestyle interventions may be effective at this 'teachable moment', as men begin AS for low-risk PC.

Prognostic value of Ki67 in localized prostate carcinoma: a multi-institutional study of >1000 prostatectomies.

BACKGROUND: Expanding interest in and use of active surveillance for early state prostate cancer (PC) has increased need for prognostic biomarkers. Using a multi-institutional tissue microarray resource including over 1000 radical prostatectomy samples, we sought to correlate Ki67 expression captured by an automated image analysis system with clinicopathological features and validate its utility as a clinical grade test in predicting cancer-specific outcomes. METHODS: After immunostaining, the Ki67 proliferation index (PI) of tumor areas of each core (three cancer cores/case) was analyzed using a nuclear quantification algorithm (Aperio). We assessed whether Ki67 PI was associated with clinicopathological factors and recurrence-free survival (RFS) including biochemical recurrence, metastasis or PC death (7-year median follow-up). RESULTS: In 1004 PCs (∼4000 tissue cores) Ki67 PI showed significantly higher inter-tumor (0.68) than intra-tumor variation (0.39). Ki67 PI was associated with stage (P<0.0001), seminal vesicle invasion (SVI, P=0.02), extracapsular extension (ECE, P<0.0001) and Gleason score (GS, P<0.0001). Ki67 PI as a continuous variable significantly correlated with recurrence-free, overall and disease-specific survival by multivariable Cox proportional hazard model (hazards ratio (HR)=1.04-1.1, P=0.02-0.0008). High Ki67 score (defined as ⩾5%) was significantly associated with worse RFS (HR=1.47, P=0.0007) and worse overall survival (HR=2.03, P=0.03). CONCLUSIONS: In localized PC treated by radical prostatectomy, higher Ki67 PI assessed using a clinical grade automated algorithm is strongly associated with a higher GS, stage, SVI and ECE and greater probability of recurrence.

Identification of novel modifiers of Aß toxicity by transcriptomic analysis in the fruitfly.

The strongest risk factor for developing Alzheimer's Disease (AD) is age. Here, we study the relationship between ageing and AD using a systems biology approach that employs a Drosophila (fruitfly) model of AD in which the flies overexpress the human Aß42 peptide. We identified 712 genes that are differentially expressed between control and Aß-expressing flies. We further divided these genes according to how they change over the animal's lifetime and discovered that the AD-related gene expression signature is age-independent. We have identified a number of differentially expressed pathways that are likely to play an important role in the disease, including oxidative stress and innate immunity. In particular, we uncovered two new modifiers of the Aß phenotype, namely Sod3 and PGRP-SC1b.

Effect of topical diphenhydramine on the laryngeal chemoreflex.

OBJECTIVE: To study diphenhydramine nebulization as a clinically applicable method for blunting laryngeal chemoreflex (LCR)-associated apnea. INTERVENTIONS: Fourteen piglets aged 15 to 18 days were studied. In 7 piglets, diphenhydramine hydrochloride (5.0 mg/kg) was nebulized onto the laryngeal mucosa after a baseline response was obtained. RESULTS: After a 10-minute waiting period, the mean +/- SD LCR-induced apnea duration decreased from 29 +/- 13 seconds in the control animals to 15 +/- 5 seconds in the treated group (P = .02, 1-factor analysis of variance). After 1 hour, no treatment effect was seen. CONCLUSIONS: Nebulization of diphenhydramine can effectively reduce LCR-induced apnea for a short time. Nebulization of longer-acting agents may provide an effective prophylaxis of LCR-induced apnea.

New concepts in the study of tissue vascularization: a mathematical model of skin vascularization.

A preliminary study demonstrated the existence of a fractal structure for perforator arterial vessels of the skin and proved to be a useful tool to compare vascular trees on the basis of their complexity. Fractal analysis of axial-perforator arteriovenous vascular trees was performed on the skin of mice after injection of the arterial network by india ink. Fractal analysis was performed by box counting. Fractal dimension D was determined for 35 venous and 31 arterial perforator vessels (D = 1.302 and 1.264, respectively) and 5 venous and 3 arterial axial vessels (D = 1.374 and 1.328, respectively) (r2 > or = 0.985). All vascular networks show a fractal structure, characterized by a specific D. These values are relatively constant; D is a function of the anatomic and physiologic characteristics. There was no significant difference between venous and arterial networks, nor was there between axial and perforator networks (p < 0.05); this demonstrates a similar efficacy in terms of perfusion of the skin. A computer simulation based on fractal theory has been developed to reproduce the two kinds of vascular networks. Fractals are the result of a construction procedure that is repeated and repeated so that the iteration of a very simple rule can produce seemingly complex shapes, such as vascular networks. The basic module that is repeated in the whole structure is Y-shaped and is termed the generator; this generator is applied to a basic structure, called the initiator. After a few iterations, a vascular network is obtained. The difference between axial and perforator vascular networks is the choice of the initiator, whereas the generator is identical.(ABSTRACT TRUNCATED AT 250 WORDS)

Seasonal patterns of bulimia nervosa.

OBJECTIVE: The aim of this research was to determine whether a seasonal pattern to symptoms of bulimia nervosa could be identified. METHOD: In study 1, seasonal patterns of binge-purge frequency and mood were compared between 31 patients with bulimia nervosa and 31 age-matched normal comparison subjects, using a modified (to include binge and purge items) version of the Seasonal Pattern Assessment Questionnaire. Study 2 involved a cross-sectional examination of binge and purge frequency and of depressive symptoms in 197 patients with bulimia nervosa assessed at various months of the year over a 4-year period. RESULTS: In both the retrospective and cross-sectional studies, binge behavior was found to be highly associated with photoperiod. According to the modified Seasonal Pattern Assessment Questionnaire, purging behavior and mood also varied seasonally among patients with bulimia nervosa. However, purging behavior and severity of depression did not appear to be related to photoperiod in the cross-sectional study. The rate of seasonal affective disorder (syndromal and subsyndromal) defined by the Seasonal Pattern Assessment Questionnaire was higher among the bulimic group than the comparison subjects, but not as high as has been reported for depression in bulimia nervosa. CONCLUSIONS: The results strongly support the interpretation that symptoms of bulimia nervosa primarily associated with food intake patterns are influenced by seasonal variation, and this effect may be mediated by light availability.

Probing the role of glutamic acid 144 in the EcoRI endonuclease using aspartic acid and glutamine replacements.

The x-ray structure of the EcoRI endonuclease-DNA complex (3) suggests that hydrogen bonds between amino acids, glutamic acid 144, arginine 145, and arginine 200, and major groove base moieties are the molecular determinants of specificity. We have investigated residue 144 using aspartate and glutamine substitutions introduced by site-directed mutagenesis. Substitution with glutamine results in a null phenotype (at least a 2000-fold reduction in activity). On the other hand, the aspartic acid mutant (ED144) retained in vivo activity. Substrate binding and catalytic studies were done with purified ED144 enzyme. The affinity of the ED144 enzyme for the canonical sequence 5'-GAATTC-3' is about 340-fold less than the wild-type (WT) enzyme, while its affinity for nonspecific DNA is about 50 times greater. The ED144 enzyme cleaves one strand in the EcoRI site in plasmid pBR322 with a kcat/Km similar to WT. In contrast to the WT enzyme, the ED144 enzyme dissociates after the first strand cleavage. Partitioning between cleavage and dissociation at the first and second cleavage steps for the ED144 enzyme is extremely salt-sensitive. The altered partitioning results largely from a destabilization of the enzyme-DNA complex, particularly the enzyme-nicked DNA complex, with only small changes in the respective cleavage rates. The hydrogen bonds of Glu-144 are critical, they appear to act cooperatively with other specificity contacts to stabilize the enzyme-DNA complex.

Lp(a) levels in different types of dyslipidemia in the French population.

The serum lipoprotein Lp(a) concentration was measured in 1065 individuals in order to assess whether there was a relation between the type of dyslipidemia and the level of Lp(a). Males and females, aged between 2 and 83 years old, were included in the study. Quantification was performed by an immunonephelometric technique. The whole population was divided into normolipidemic (NL), type IIa without xanthoma (type IIa), type IIa with xanthoma (FH), type IIb and type IV phenotypes. Lp(a) level was arbitrarily divided into 5 subclasses in each group of dyslipidemia and in the normolipidemic group. In addition each group was divided according to sex and whether or not they were under treatment. We observed a significant difference between the median Lp(a) level of the normolipidemic group (NL) and of the dyslipidemic group as a whole. Median Lp(a) levels in the 4 dyslipidemic groups did not differ significantly. Sex, age and treatment did not influence the distribution of Lp(a) values distribution. Only weak correlations (Spearman's rank test) were observed between Lp(a) and other lipid parameters (total cholesterol, LDL, apo B, HDL, triglycerides): the highest correlation (r' = 0.15) was between Lp(a) and apo B. We conclude that Lp(a) level is not influenced by the type of dyslipidemia, sex or hypolipidemic drugs.

Reiterative copying by E.coli RNA polymerase during transcription initiation of mutant pBR322 tet promoters.

The major in vitro transcripts from the tet promoter of pBR322 derivatives pTA22 and pTA33 have heterogeneous 5' ends consisting of variable lengths of oligo(A). Their structure is 5'pppAnU..., where n ranges from 1 to greater than 12, but the template strand can encode at most four A residues at the site of transcription initiation. The abundance of additional A residues at the 5' end of the pTA22 and pTA33 tet transcripts could be reduced by elevating the concentration of UTP, but even at high concentrations (greater than 1 mM) non-cognate A residues were still observed. Aberrant initiation was not artifactual since the major and minor transcripts of the pBR322 tet promoter region, and other transcripts arising from minor promoters on pTA22 or pTA33 DNA all had unique 5' termini. Mixing experiments showed that RNA polymerase did not utilize pppA2-4-OH produced by abortive initiation as primers. The data suggest that the initial nascent RNA chain 'slips' in the 5' direction during elongation opposite T4 on the template strand causing RNA polymerase to reiteratively add A residues to the 5' end of the transcript. The generality and possible significance of this mechanism is discussed.

Comparison of the nucleotide and amino acid sequences of the RsrI and EcoRI restriction endonucleases.

The RsrI endonuclease, a type-II restriction endonuclease (ENase) found in Rhodobacter sphaeroides, is an isoschizomer of the EcoRI ENase. A clone containing an 11-kb BamHI fragment was isolated from an R. sphaeroides genomic DNA library by hybridization with synthetic oligodeoxyribonucleotide probes based on the N-terminal amino acid (aa) sequence of RsrI. Extracts of E. coli containing a subclone of the 11-kb fragment display RsrI activity. Nucleotide sequence analysis reveals an 831-bp open reading frame encoding a polypeptide of 277 aa. A 50% identity exists within a 266-aa overlap between the deduced aa sequences of RsrI and EcoRI. Regions of 75-100% aa sequence identity correspond to key structural and functional regions of EcoRI. The type-II ENases have many common properties, and a common origin might have been expected. Nevertheless, this is the first demonstration of aa sequence similarity between ENases produced by different organisms.

Determinants of EcoRI endonuclease sequence discrimination.

The arginine at position 200 of EcoRI endonuclease is thought to make two hydrogen bonds to the guanine of the sequence GAATTC and thus be an important determinant of sequence discrimination. Arg-200 was replaced by each of the other 19 naturally occurring amino acids, and the mutant endonucleases were assessed for activities in vivo and in vitro. The mutant endonuclease with lysine at position 200 exhibits the most in vivo activity of all the position 200 mutants, although the in vitro activity is less than 1/100th of wild-type activity. Five other mutants show more drastically reduced levels of in vivo activity (Cys, Pro, Val, Ser, and Trp). The Cys, Val, and Ser mutant enzymes appear to have in vivo activity which is specific for the wild-type canonical site despite the loss of hydrogen bonding potential at position 200. The Pro and Trp mutants retain in vivo activity which is independent of the presence of the EcoRI methylase. In crude cell lysates, only the Cys mutant shows a very low level of in vitro activity. None of the mutant enzymes show a preference for alternative sites in assays in vitro. The implications of these results are discussed.