Strength Training Improves Exercise Economy in Triathletes During a Simulated Triathlon.

PURPOSE: The completion of concurrent strength and endurance training can improve exercise economy in cyclists and runners; however, the efficacy of strength training (ST) implementation to improve economy in long-distance (LD) triathletes has not yet been investigated. The purpose of this study was to investigate physiological outcomes in LD triathletes when ST was completed concurrently to endurance training. METHODS: A total of 25 LD triathletes were randomly assigned to either 26 weeks of concurrent endurance and ST (n = 14) or endurance training only (n = 11). The ST program progressed from moderate (8-12 repetitions, ≤75% of 1-repetition maximum, weeks 0-12) to heavy loads (1-6 repetitions, ≥85% of 1-repetition maximum, weeks 14-26). Physiological and performance indicators (cycling and running economy, swim time, blood lactate, and heart rate) were measured during a simulated triathlon (1500-m swim, 60-min cycle, and 20-min run) at weeks 0, 14, and 26. Maximal strength and anthropometric measures (skinfolds and body mass) were also collected at these points. RESULTS: The endurance strength group significantly improved maximal strength measures at weeks 14 and 26 (P < .05), cycling economy from weeks 0 to 14 (P < .05), and running economy from weeks 14 to 26 (P < .05) with no change in body mass (P > .05). The endurance-only group did not significantly improve any economy measures. CONCLUSIONS: The addition of progressive load ST to LD triathletes' training programs can significantly improve running and cycling economy without an increase in body mass.

Regulation of midgut growth, development, and metamorphosis.

The insect midgut is an important site of entry for pathogens and insect control agents. This review focuses on recent information related to midgut epithelial growth, metamorphosis, and repair as a defense against pathogens. The roles of stem cell mitogens and differentiation factors are described. Included is a discussion of apoptosis and autophagy in the yellow body. Sloughing, also described, protects the midgut from virus infections and bacterial toxins through death and replacement of affected cells. The mechanisms by which the repair process reduces the effectiveness of pest control strategies are discussed. Primary tissue culture methods also are described, and their value in understanding the mechanisms by which biologically based insecticides work is discussed.

Estrogen receptors beta4 and beta5 are full length functionally distinct ERbeta isoforms: cloning from human ovary and functional characterization.

We describe here the cloning and functional characterization of two unique ER isoforms, ERbeta4 and ERbeta5. The full length ERbeta4 and ERbeta5 were identified by asymmetric PCR using human ovary cDNA, cloning, and sequence analyses. Both receptors share identical sequences with ERbeta1 from exon 1 to exon 7. In the place of exon 8, ERbeta4 has unique sequences arising from a region downstream of the ERbeta gene and upstream of the SYNE2 gene. ERbeta5 has sequences arising from retention of the 5' end of the intron between exon 7 and 8. Both receptors bind promoter sequences on DNA but do not bind estrogen. They translocate to the nucleus and exhibit three to four times higher estrogen-independent transcriptional activity than ERbeta1. When co-transfected with ERalpha, they predominantly form heterodimers and negatively regulate its transcriptional activity. Estrogen-independent transcriptional activity of ERbeta5, but not ERbeta4, was inhibited by ERalpha, demonstrating for the first time that ERalpha regulates ERbeta. Tissue-specific expression of ERbeta4 and ERbeta5, together with their ligand-independent transcriptional properties and ERalpha modulating activities, could have a number of implications in seemingly unlinked biological processes regulated by estrogen.

Unequal protection for patient rights: the divide between university and health ethics committees.

Despite recommendations from the Cartwright Report ethical review by health ethics committees has continued in New Zealand without health practitioners ever having to acknowledge their dual roles as health practitioners researching their own patients. On the other hand, universities explicitly identify doctor/research-patient relations as potentially raising conflict of role issues. This stems from the acknowledgement within the university sector itself that lecturer/research-student relations are fraught with such conflicts. Although similar unequal relationships are seen to exist between health resarchers and their patients, the patient/subjects are not afforded the levels of protection that are afforded student/subjects. In this paper we argue that the difference between universities and health research is a result of the failure of the Operational Standard Code for Ethics Committees to explicitly acknowledge the vulnerability of the patient and conflict of interests in the dual roles of health practitioner/researcher. We end the paper recommending the Ministry of Health consider the rewriting of the Operational Standard Code for Ethics Committees, in particular in the rewriting of section 26 of the Operational Standard Code for Ethics Committees. We also identify the value of comparative ethical review and suggest the New Zealand's Health Research Council's trilateral relationship with Australia's NHMRC (National Health and Medical Research Council) and Canada's CIHR (Canadian Institute of Health Research) as a useful starting point for such a process.

Informing consent in New Zealand research: researchers' conflict of interest and patient vulnerability.

The authors, members of two different regional health ethics committees, write about their observations evaluating ethics application where researchers' conflicts of interest go unacknowledged either when researching their own patients or when the research subjects experience a temporary vulnerability--i.e. they have learned they are to lose a body part such as a breast, bowel, or limb. Currently the operational standard code of ethics does not address either issue even when New Zealand health ethics had its origins at National Women's Hospital where a physician researched his own patients. Under this situation the researcher's conflict of role undermined informed consent. The paper ends rewriting Section 26 of the Operational Standard.

Identification of ten exon deleted ERbeta mRNAs in human ovary, breast, uterus and bone tissues: alternate splicing pattern of estrogen receptor beta mRNA is distinct from that of estrogen receptor alpha.

Four different human tissues and breast cancer cell lines were screened to identify exon deletion variant transcripts of estrogen receptor beta (ERbeta) by reverse transcription-polymerase chain reaction using the 'splice targeted primer approach' that amplifies each category of exon deleted variants as a separate gene population. A total of 10 different variant mRNAs that have deletions in various combination of exons were identified by sequence analysis. They were exon 2Delta; exons 2 and 5-6Delta; exon 3Delta; exon 4Delta; exon 5Delta; exons 5 and 2Delta; exon 6Delta; exons 6 and 2Delta; exons 6, 2-3Delta; and exons 5-6Delta. In some cases, deletion of an exon appears to be associated with a mutation of a specific base. Although ERalpha and ERbeta are highly homologous, have identical exon and functional domain organization, exhibit similar ligand-binding profiles and interact with identical DNA response elements, the sequence of exon skipping in ERbeta pre-mRNA appears to be distinct from that of ERalpha mRNA. Furthermore, results described here also suggest that alternate splicing of ERbeta mRNA is tissue specific. The presence of a ERbeta variant profile together with other ER isoforms in a tissue may have functional implications in binding and response to a particular ligand.