Hormone replacement therapy improves contractile function and myonuclear organization of single muscle fibres from postmenopausal monozygotic female twin pairs.

Ageing is associated with a decline in muscle mass and strength leading to increased physical dependency in old age. Postmenopausal women experience a greater decline than men of similar age in parallel with the decrease in female sex steroid hormone production. We recruited six monozygous female twin pairs (55-59 years old) where only one twin pair was on hormone replacement therapy (HRT use = 7.

Hormone therapy is associated with better body composition and adipokine/glucose profiles: a study with monozygotic co-twin control design.

Objective: The aim of this study was to evaluate the possibility of preventing the metabolic health consequences of postmenopausal hypogonadism with the use of long-term hormone therapy (HT).

Methods: We used a monozygotic co-twin control design including 10 twin pairs (aged 56-62 y) discordant for HT (duration of HT, 2-10 y). In addition, 14 premenopausal women (aged 29-35 y) who did not use HT were studied to evaluate the differences in metabolic health between the premenopausal and postmenopausal states.

Muscle function in monozygotic female twin pairs discordant for hormone replacement therapy.

Introduction: Postmenopausal monozygotic twin pairs discordant for hormone replacement therapy (HRT) provide an advantageous study design controlling for genetic background for elucidating the relationships between aging, sex hormone levels, muscle strength, contractile capacity, and fatigability.

Methods: Thirteen postmenopausal monozygotic twin pairs discordant for HRT were measured for maximal voluntary torque (MVC) and twitch characteristics using electrical stimulation before and after intermittent dynamic plantarflexor exercise until exhaustion.

Results: Peak twitch torque was 32% higher in HRT users than in their non-HRT, genetically identical sisters (P = 0.

Age and estrogen-based hormone therapy affect systemic and local IL-6 and IGF-1 pathways in women.

A thorough understanding of the role of estrogens on aging-related muscle weakness is lacking. To clarify the molecular mechanisms underlying the effects of hormone replacement therapy (HRT) on skeletal muscle, we analyzed systemic protein and local mRNA levels of factors related to interleukin 6 (IL-6) and insulin-like growth factor 1 (IGF-1) pathways in 30- to 35-year-old (n = 14) women (without hormonal contraceptives) and in 54- to 62-year-old monozygotic female twin pairs discordant for HRT (n = 11 pairs, mean duration of HRT 7.3 ± 3.

Differential influence of peripheral and systemic sex steroids on skeletal muscle quality in pre- and postmenopausal women.

Aging is associated with gradual decline of skeletal muscle strength and mass often leading to diminished muscle quality. This phenomenon is known as sarcopenia and affects about 30% of the over 60-year-old population. Androgens act as anabolic agents regulating muscle mass and improving muscle performance.

Global gene expression profiles in skeletal muscle of monozygotic female twins discordant for hormone replacement therapy.

Aging is accompanied by inexorable loss of muscle tissue. One of the underlying causes for this is the massive change in the hormonal milieu of the body. The role of a female sex steroid - estrogen - in these processes is frequently neglected, although the rapid decline in its production coincides with a steep deterioration in muscle performance.

Influence of long-term postmenopausal hormone-replacement therapy on estimated structural bone strength: a study in discordant monozygotic twins.

Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT).

Effects of combined hormone replacement therapy or its effective agents on the IGF-1 pathway in skeletal muscle.

Objectives: To investigate the effects of combined hormone replacement therapy (HRT) and its effective agents on the IGF-1 signaling pathway.

Design And Methods: To examine the effects of HRT on skeletal muscle in vivo, we utilized pre- and post-intervention samples from a randomized double blinded trial with 50-57-year-old women. The intervention included the year-long use of either HRT preparation (2 mg 17β-estradiol, E₂; 1mg norethisterone acetate, NETA, n=10) or placebo (CO, n=9).

Power training and postmenopausal hormone therapy affect transcriptional control of specific co-regulated gene clusters in skeletal muscle.

At the moment, there is no clear molecular explanation for the steeper decline in muscle performance after menopause or the mechanisms of counteractive treatments. The goal of this genome-wide study was to identify the genes and gene clusters through which power training (PT) comprising jumping activities or estrogen containing hormone replacement therapy (HRT) may affect skeletal muscle properties after menopause. We used musculus vastus lateralis samples from early stage postmenopausal (50-57 years old) women participating in a yearlong randomized double-blind placebo-controlled trial with PT and HRT interventions.

Postmenopausal hormone replacement therapy modifies skeletal muscle composition and function: a study with monozygotic twin pairs.

We investigated whether long-term hormone replacement therapy (HRT) is associated with mobility and lower limb muscle performance and composition in postmenopausal women. Fifteen 54- to 62-yr-old monozygotic female twin pairs discordant for HRT were recruited from the Finnish Twin Cohort. Habitual (HWS) and maximal (MWS) walking speeds over 10 m, thigh muscle composition, lower body muscle power assessed as vertical jumping height, and maximal isometric hand grip and knee extension strengths were measured.

Effects of 32-year leisure time physical activity discordance in twin pairs on health (TWINACTIVE study): aims, design and results for physical fitness.

The physically active lifestyle is associated with low future morbidity and mortality, but the causality between physical activity and health is not always clear. As some inherited biological characteristics and childhood experiences may cause selection bias in observational studies, we sought to take them into account by identifying 16 twin pairs (7 MZ, 9 DZ, mean age 60 years) discordant for leisure time physical activity habits for thirty years. We conducted detailed health-related examinations among these twin pairs.

Combination of hormone replacement therapy and high physical activity is associated with differences in Achilles tendon size in monozygotic female twin pairs.

Estrogen concentration has been suggested to play a role in tendon abnormalities and injury. In physically active postmenopausal women, hormone replacement therapy (HRT) has been suggested to decrease tendon diameter. We hypothesized that HRT use and physical activity are associated with Achilles tendon size and tissue structure.

Catechol-o-methyltransferase gene polymorphism is associated with skeletal muscle properties in older women alone and together with physical activity.

Background: Muscle strength declines on average by one percent annually from midlife on. In postmenopausal women this decrement coincides with a rapid decline in estrogen production. The genetics underlying the effects of estrogen on skeletal muscle remains unclear.

Baculovirus-mediated immediate-early gene expression and nuclear reorganization in human cells.

Baculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV), has the ability to transduce mammalian cell lines without replication. The general objective of this study was to detect the transcription and expression of viral immediate-early genes in human cells and to examine the interactions between viral components and subnuclear structures. Viral capsids were seen in large, discrete foci in nuclei of both dividing and non-dividing human cells.

Muscular transcriptome in postmenopausal women with or without hormone replacement.

The loss of muscle mass and strength with aging is well characterized, but our knowledge of the molecular mechanisms underlying the development of sarcopenia remains incomplete. Although menopause is often accompanied with first signs of age-associated changes in muscle structure and function, the effects of hormone replacement therapy (HRT) or menopause-related decline in estrogen production in the muscles of postmenopausal women is not well understood. Furthermore the knowledge of the global transcriptional changes that take place in skeletal muscle in relation to estrogen status has thus far been completely lacking.

An IC-PCR method for detection of Cryptosporidium and Giardia in natural surface waters in Finland.

We developed an immunocapture-based polymerase chain reaction (PCR) assay for simultaneous detection of Cryptosporidium parvum oocysts and Giardia intestinalis cysts in surface water. Using primer pairs Cry9/Cry15 and LaxA/LaxB for Cryptosporidium and Gdh1/Gdh4 for Giardia, the sensitivity of the entire detection procedure (dealing with concentration, separation, DNA purification and PCR amplification) was at the level of 50-100 oocysts and cysts. Of 54 surface water samples, 4 were positive for Cryptosporidium and 1 for Giardia.

Simultaneous detection of Cryptosporidium parvum and Giardia in sewage sludge by IC-PCR.

Aims: The aim of this study was to develop a method based on immunomagnetic capture and polymerase chain reaction (IC-PCR assay) for detection of Cryptosporidium parvum and Giardia intestinalis in sewage sludge.

Methods And Results: The detection limit of the IC-PCR assay for both organisms was 625 oocysts and cysts ml(-1). By hybridization of PCR products the sensitivity could be increased to 125 oocysts and cysts ml(-1).

Metals in Finnish liqueurs.

The metal content of some representative Finnish berry liqueurs was determined by atomic absorption spectrometry. The berry liqueurs were prepared from cloudberry (Rubus chamaemorus), arctic bramble (Rubus arcticus), cranberry (Vaccinum oxycoccus), lingonberry (Vaccinum vitis-idaea) and sea buckthorn (Hippophae rhamnoides). In addition some other Finnish berry, fruit and herbal liqueurs were analyzed.