The Dairy and Cancer Controversy: Milking the Evidence

PURPOSE OF REVIEW

Cancer risk reduction remains a significant concern for both individuals with a cancer diagnosis and those aiming to prevent it. Dairy products, a source of beneficial dietary nutrients, have sparked controversy regarding their impact on cancer risk.

RECENT FINDINGS

Evidence indicates that dairy consumption, particularly milk, can decrease colorectal cancer risk. However, cow's milk, a key dairy product, exposes individuals to growth hormones, notably insulin-like growth factor-1, potentially elevating cancer risk. Extensive research supports the link between dairy intake and heightened prostate cancer risk. Nonetheless, investigations into dairy's association with breast, ovarian, and other cancers yield mixed results. The overall data on dairy and cancer remains inconclusive. Available data suggests that a diet emphasizing fiber-rich foods such as whole grains, fruits, and vegetables, while restricting milk and dairy intake-similar to the Mediterranean dietary pattern-might mitigate cancer incidence. However, further research is crucial to elucidate the precise role of dairy products in overall cancer risk.

Sustained periodic terrestrial locomotion in air-breathing fishes

While emergent behaviours have long been reported for air-breathing osteichthyians, only recently have researchers undertaken quantitative analyses of terrestrial locomotion. This review summarizes studies of sustained periodic terrestrial movements by air-breathing fishes and quantifies the contributions of the paired appendages and the axial body to forward propulsion. Elongate fishes with axial-based locomotion, e.g. the ropefish Erpetoichthys calabaricus, generate an anterior-to-posterior wave of undulation that travels down the axial musculoskeletal system and pushes the body against the substratum at multiple points. In contrast, appendage-based locomotors, e.g. the barred mudskipper Periophthalmus argentilineatus, produce no axial bending during sustained locomotion, but instead use repeated protraction-retraction cycles of the pectoral fins to elevate the centre of mass and propel the entire body anteriorly. Fishes that use an axial-appendage-based mechanism, e.g. walking catfishes Clarias spp., produce side-to-side, whole-body bending in co-ordination with protraction-retraction cycles of the pectoral fins. Once the body is maximally bent to one side, the tail is pressed against the substratum and drawn back through the mid-sagittal plane, which elevates the centre of mass and rotates it about a fulcrum formed by the pectoral fin and the ground. Although appendage-based terrestrial locomotion appears to be rare in osteichthyians, many different species appear to have converged upon functionally similar axial-based and axial-appendage-based movements. Based on common forms observed across divergent taxa, it appears that dorsoventral compression of the body, elongation of the axial skeleton or the presence of robust pectoral fins can facilitate effective terrestrial movement by air-breathing fishes.

Gleason score predicts androgen independent progression after androgen deprivation therapy

OBJECTIVE

The Gleason system is the most widely utilized histologic grading system for prostate cancer and a powerful predictor of cancer behavior. In this study, we evaluated the prognostic value of the Gleason grading system in predicting progression to androgen independent prostate cancer (AIPC).

METHODS

Records from 150 patients with advanced or metastatic prostate cancer treated with androgen deprivation therapy (ADT) were retrospectively reviewed. Androgen independent progression was defined as two consecutive elevations of serum prostate specific antigen (PSA) above the nadir value. Kaplan-Meier and the Cox proportional hazards methods were used to assess potential predictors of progression to AIPC.

RESULTS

Patients with low and moderate Gleason scores experienced significantly longer remissions compared to those with Gleason score of 8-10 (p=0.0006, Log-Rank test). The cumulative hazard of progressing to AIPC increased by almost 70% for each unit increase in total Gleason score.

CONCLUSION

In this patient cohort the Gleason score was the only independent predictor of progression to AIPC.

Comparative kinematics of the forelimb during swimming in red-eared slider (Trachemys scripta) and spiny softshell (Apalone spinifera) turtles

Softshell turtles (Family Trionychidae) possess extensive webbing between the digits of the manus, suggesting that the forelimb may serve as an effective thrust generator during aquatic locomotion. However, the hindlimb has previously been viewed as the dominant propulsive organ in swimming freshwater turtles. To evaluate the potential role of the forelimb in thrust production during swimming in freshwater turtles, we compared the forelimb morphology and three-dimensional forelimb kinematics of a highly aquatic trionychid turtle, the spiny softshell Apalone spinifera, and a morphologically generalized emydid turtle, the red-eared slider Trachemys scripta. Spiny softshells possess nearly twice as much forelimb surface area as sliders for generating drag-based thrust. In addition, although both species use drag-based propulsion, several aspects of forelimb kinematics differ significantly between these species. During the thrust phase of the forelimb cycle, spiny softshells hold the elbow and wrist joints significantly straighter than sliders, thereby further increasing the surface area of the limb that can move water posteriorly and increasing the velocity of the distal portion of the forelimb. These aspects of swimming kinematics in softshells should increase forelimb thrust production and suggest that the forelimbs make more substantial contributions to forward thrust in softshell turtles than in sliders. Spiny softshells also restrict forelimb movements to a much narrower dorsoventral and anteroposterior range than sliders throughout the stroke, thereby helping to minimize limb movements potentially extraneous to forward thrust production. These comparisons demonstrate considerable diversity in the forelimb kinematics of turtles that swim using rowing motions of the limbs and suggest that the evolution of turtle forelimb mechanics produced a variety of contrasting solutions for aquatic specialization.

Measurement of high-molecular-weight polycyclic aromatic hydrocarbons in soils by particle beam high-performance liquid chromatography-mass spectrometry

Polycyclic aromatic hydrocarbons (PAHs) comprise a class of potentially hazardous com- pounds of concern to the U.S. EPA. The application of particle-beam (PB) liquid chromatography-mass spectrometry (LC-MS) to the measurement of high-molecular-weight PAHs was investigated. Instrument performance was evaluated for 16 PAHs in the molecular weight range 300-450 u. The PAHs were separated by reverse-phase high-performance liquid chromatography via a polymeric octadecylsilica (C-18) packing and gradient elution with methanol-tetrahydrofuran. On-column instrument detection limits, as measured by selected ion monitoring on the singly charged molecular ion of each PAH, were found to be 0.15-0.60 ng for PAHs with molecular weights up to 352 u and 2-4 ng for PAHs with molecular weights greater than 352 u. Instrument response was generally linear for PAHs with molecular weights 300-352 u and generally nonlinear for PAHs with molecular weights greater than 352 u. The PB electron impact mass spectra of the PAHs were found to vary with the ion distribution ratio of the singly charged molecular ion to the doubly charged molecular ion, dependent on molecular weight, ion source temperature, and concentration. Analysis by PB LC-MS was applied to extracts of PAH-spiked soil and a PAH-contaminated soil from the Pacific Northwest. Target analyte concentrations in the PAH-contaminated soil ranged from 0.85 to 84 µg/g. Quantitative estimates for nontarget PAHs also were determined. Analysis of a second soil extract from a hazardous waste site in the northeast part of the United States displayed isomeric patterns of high-molecular-weight PAHs similar to those of the Pacific Northwest extract.

Evidence for thermal decomposition contributions to the mass spectra of chlorinated phenoxyacid herbicides obtained by particle beam liquid chromatography mass spectrometry

The spectral quality of a group of chlorinated phenoxyacid herbicides has been shown to degrade under certain conditions upon introduction into the mass spectrometer by a particle beam interface. Experiments were performed to investigate these changes in spectra. Normalized ion chromatograms were generated for the herbicides, and the results showed a broadening of the profiles of some ions, indicating a longer residence time in the ion source. These ions were postulated as coming from the ionization of thermal degradation products from the herbicides. The generation of these ions was dependent on ion source temperature, analyte concentration, and, by implication, ion source cleanliness. Tandem mass spectrometry experiments were performed on these ions from the herbicides and ions from the corresponding phenols. The tandem mass spectra of the ions from the herbicides were similar to the tandem mass spectra of the ions from the phenols. Therefore, it appears that the particle beam mass spectra of the chlorinated phenoxyacid herbicides are composite spectra with contributions from the gas phase ionization of the parent herbicides and thermal decomposition products.