Genetic pathways in the evolution of morphologically distinct colorectal neoplasms

Colorectal adenomas can be morphologically classified as exophytic or flat. Polypoid cancers and cancers arising de novo (ie., without any adenomatous component) might be the results of genetic progression from exophytic and flat adenomas, respectively. In this study, we examined 94 morphologically distinct neoplastic specimens for mutations in K-RAS and analyzed 10 microsatellite loci tightly linked to the tumor suppressor genes APC, p53, DCC/SMAD4, hMSH2, and hMLH1. K-RAS mutations were significantly associated with exophytic adenomas [11 of 21 (52%)] compared to flat adenomas [2 of 13(15%), P < 0.03] and polypoid cancers [17 of 25 (68%)] compared to cancers arising de novo [7 of 25 (28%), P < 0.01]. Two polypoid cancer cases demonstrated three and four different K-RAS mutations, respectively, suggesting multiple areas of clonal expansion. Cancers arising de novo were significantly associated with loss of heterozygosity (LOH) at chromosome 3p compared to pol ypoid cancers [6 of 18(33%) versus 1 of 20(5%), P < 0.03], whereas the prevalence of LOH at chromosomes 2p, 5q, 17p, and 18q and microsatellite instability were not different between the groups. For all cancers, LOH at chromosomes 17p and 18q occurred in 47 and 51%, respectively. However, LOH at 17p and 18q occurred in 0 and 16% of benign lesions, respectively, suggesting their role in malignant transformation. There was no difference in LOH at chromosomes 17p and 18q between exophytic and flat lesions. These findings suggest that (a) mutant K-RAS is associated with the exophytic growth of colonic neoplasms, and that (b) some colorectal cancers arising de novo lose chromosome 3p during their evolution, which is not seen in polypoid cancers. Half of all cancers lose chromosomes 17p and 18q at or near the malignant transition of benign lesions as reported previously, irrespective of morphology. There may be more than one genetic avenue for colorectal cancer formation, and this correlates with the morphological characteristics.     

Correlation of margin status and extraprostatic extension with progression of prostate carcinoma.

BACKGROUND: The correlation of surgical margins and extraprostatic extension (EPE) with progression is uncertain with regard to prostate carcinoma patients treated by radical prostatectomy. The objective of this study was to define factors predictive of cancer progression; emphasis was placed on surgical margins and their relation to extraprostatic extension. METHODS: The study group consisted of 377 patients who were treated by radical retropubic prostatectomy and bilateral pelvic lymphadenectomy at the Mayo Clinic between 1986 and 1993. All specimens were totally embedded and whole-mounted. Patients ranged in age from 41 to 79 years (mean, 65 years). Those with seminal vesicle invasion or lymph node metastasis and those treated preoperatively with radiation or androgen deprivation were excluded. Final pathologic T classifications were pT2a (41 patients), pT2b (237), and pT3a (99). Progression was defined as biochemical failure (prostate specific antigen [PSA] >0.2 ng/mL), clinical or biopsy-proven local recurrence, or distant metastasis. The mean follow-up was 5.8 years (range, 0.2-11.4 years). Seventy-nine patients who received adjuvant treatment within 3 months after surgery were excluded from survival analysis. RESULTS: The overall margin positivity rate was 29%. Seventy-two patients (19%) had only positive surgical margins without evidence of EPE ("surgical incision"), 53 (14%) had only EPE, 37 (10%) had both, and 215 (57%) had neither. Positive margins were correlated with the finding of EPE (P = 0.003). Progression free survival rates at 5 and 10 years were 88% and 67%, respectively. In univariate analysis, preoperative PSA concentration, positive surgical margins, Gleason grade, cancer volume, and DNA ploidy were significant in predicting progression (P values, <0.001, <0.001, 0.01, 0.007, and <0.001, respectively). In multivariate analysis, margin status and DNA ploidy were independent predictors of progression (relative risk for margin status, 1.9; 95% confidence interval [CI], 1.1-3.4; P = 0.03; relative risk for DNA ploidy, 5.1; 95% CI, 2.4-10.9; P<0.001). Among patients with positive margins, 5-year progression free survival was 78% for those with negative EPE and 55% for those with positive EPE. CONCLUSIONS: Surgical margin status and DNA ploidy were independent predictors of progression after radical prostatectomy. To improve cancer control, adjuvant therapy may be considered for patients with positive surgical margins or nondiploid cancer.     

Effect of triiodothyronine on mitochondrial energy coupling in human skeletal muscle

The mechanism underlying the regulation of basal metabolic rate by thyroid hormone remains unclear. Although it has been suggested that thyroid hormone might uncouple substrate oxidation from ATP synthesis, there are no data from studies on humans to support this hypothesis. To examine this possibility, we used a novel combined (13)C/(31)P nuclear magnetic resonance (NMR) approach to assess mitochondrial energy coupling in skeletal muscle of seven healthy adults before and after three days of triiodothyronine (T(3)) treatment. Rates of ATP synthesis and tricarboxylic acid (TCA) cycle fluxes were measured by (31)P and (13)C NMR spectroscopy, respectively, and mitochondrial energy coupling was assessed as the ratio. Muscle TCA cycle flux increased by approximately 70% following T(3) treatment. In contrast, the rate of ATP synthesis remained unchanged. Given the disproportionate increase in TCA cycle flux compared with ATP synthesis, these data suggest that T(3) promotes increased thermogenesis in part by promoting mitochondrial energy uncoupling in skeletal muscle.     

Levels of multiple proteins in gingival crevicular fluid and intra-amniotic complications in women with preterm prelabor rupture of membranes

Objective: The primary aim of this study was to identify the association between the local inflammatory response in gingival crevicular fluid measured by the levels of multiple proteins and maternal and intra-amniotic inflammatory responses measured by maternal serum C-reactive protein (CRP) and amniotic fluid interleukin (IL)-6 concentrations, respectively, in women with preterm prelabor rupture of membranes (PPROM).

Methods: A prospective study was performed in which 78 women with singleton pregnancies complicated by PPROM between 24?+?0 and 36?+?6 weeks of gestation were included. Transabdominal amniocenteses were performed at the time of admission. A bedside assessment of amniotic fluid IL-6 was performed. Maternal serum CRP concentration was also measured at the time of admission. Gingival crevicular fluid was collected from the pocket of the selected tooth (the tooth with the deepest pocket) using standard sterile paper strips within 72?h after admission. Twenty-six proteins in the gingival crevicular fluid were assessed by multiplex the Meso-Scale technology.

Results: No correlations between the levels of proteins in the gingival crevicular fluid and maternal serum CRP and amniotic fluid IL-6 concentrations were found, except for a weak positive correlation between granulocyte macrophage colony-stimulating factor and CRP.

Conclusions: The local inflammatory response in the gingival crevicular fluid is not related to the maternal and intra-amniotic inflammatory responses in women with PPROM.     

Male Testosterone Does Not Adapt to the Partner's Menstrual Cycle

Background

It has not yet been established whether men in heterosexual relationships adapt their hormone levels to their female partner's menstrual cycle to allocate reproductive resources to the period when the female is actually fertile.

Validation of Partin tables for predicting pathological stage of clinically localized prostate cancer

PURPOSE: The accurate prediction of pathological stage of prostate cancer using preoperative factors is a critical aspect of treatment. In 1997 Partin et al published tables predicting pathological stage using clinical stage, Gleason score and prostate specific antigen (PSA). We tested the validity of the Partin tables. MATERIALS AND METHODS: From 1990 to 1996 inclusively 5,780 patients underwent bilateral pelvic lymphadenectomy and radical prostatectomy for prostate cancer at the Mayo Clinic. However, only 2,475 of these patients met all inclusion criteria of no preoperative treatment, known biopsy Gleason score, available preoperative PSA done either before biopsy or more than 28 days after biopsy and clinical stage T1, T2 or T3a. Among the 2,475 patients 15 had positive lymph nodes and planned prostatectomy was abandoned. The receiver operating characteristics (ROC) curve area, observed and predicted Partin rates of each pathological stage, and positive and negative predictive values were used to compare the Mayo study to the Partin tables. RESULTS: The distribution of pathological stage was organ confined in 67% of Mayo cases versus 48% in the Partin study, extracapsular without seminal vesicle or node involvement in 18% versus 40%, seminal vesicle involvement without nodes in 9% versus 7% and were positive nodes in 6% versus 5%. Using the predicted probabilities of Partin et al the ROC curve area for predicted node positive disease was 0.84 for Mayo cases compared to an estimated 0. 82 in the Partin series. The ROC curve area for predicting organ confined cancer was 0.76 for the Mayo Clinic compared to an estimated 0.73 for the Partin series. The observed rates of node positive disease were similar to those predicted (Partin) based on clinical stage, PSA and Gleason score. For organ confined disease Mayo rates were consistently higher than those predicted from the Partin series using a cut point of 0.50 or greater. Positive and negative predictive values were 0.83 and 0.49 versus 0.63 and 0.70 for the Mayo Clinic and Partin series. CONCLUSIONS: Our study provides strong evidence that sensitivity and specificity of the Partin tables for external clinical sites are similar to what was reported.     

The three wheeler--a menace to the preadolescent child

Children riding three-wheeled motorcycles have recently become victims of serious or fatal accidents. Twelve children (aged 3 to 12 years, mean, 8.7 years) all white, sustained serious or fatal injuries as a result of striking objects or overturning while riding these vehicles. The injured children were preadolescent, white, rural, male, and from relatively affluent families. Most injuries were to the head and upper torso causing severe cosmetic and functional deficits. Our experience suggests the need for better regulations for these vehicles when being ridden by children.     

Photographic recording of slit-lamp appearances of the ocular fundus.

The four methods of illumination in the use of slit-lamp biomicroscopy of the anterior segment, described first by Vogt, are equally useful in the posterior part of the eye. Examination of the ocular fundus is more difficult. In particular, photography of the central and peripheral parts of the fundus demands additional technical arrangements if all the appearances of biomicroscopy are to be recorded.     

Spectrofluorometric analysis of select 1,4-benzodiazepine derivatives

The optimal conditions for spectrofluorimetric determination of oxazepam and nitrazepam in substance and pharmaceutical preparations were determined. Simultaneous comparison with spectrophotometric method was performed.