Publications by authors named "Shin Yamazaki"

Article Synopsis
  • Prior studies on prenatal mercury (Hg) exposure's effects on the secondary sex ratio have been inconsistent, and cord blood Hg measurement hasn't been previously utilized.
  • This research used data from the Japan Environment and Children's Study to analyze mercury and selenium (Se) levels in mother-child pairs, focusing on their relationship to the secondary sex ratio.
  • The findings suggest that higher Hg levels in cord blood (not maternal blood) were linked to a greater likelihood of male births, with no significant differences based on selenium levels.
View Article and Find Full Text PDF

Microtubule (MT)-dependent transport is a critical means of intracellular movement of cellular cargo by kinesin and dynein motors. MT-dependent transport is tightly regulated by cellular MT-associated proteins (MAPs) that directly bind to MTs and either promote or impede motor protein function. Viruses have been widely shown to usurp MT-dependent transport to facilitate their virion movement to sites of replication and/or for exit from the cell.

View Article and Find Full Text PDF

Background: The developing brains are sensitive to methylmercury (MeHg). However, the exposure to MeHg in baby foods and toddler meals remains unknown. This study aimed to determine MeHg intake from baby food or toddler meals, and to investigate the relationship with child hair total mercury (THg).

View Article and Find Full Text PDF
Article Synopsis
  • Women with polycystic ovary syndrome (PCOS) have a higher risk of gestational diabetes mellitus (GDM), particularly depending on their pre-pregnancy body mass index (BMI).
  • A study in Japan assessed this risk using data from nearly 93,000 singleton pregnancies, finding that women with PCOS showed increased GDM risk mainly in those with higher BMI (G4 and G5 categories).
  • The findings indicate that understanding the relationship between PCOS and BMI can help tailor preconception counseling for women at risk for GDM.
View Article and Find Full Text PDF

Using an open-source operant feeding device (FED3), we measured food-seeking nose poking behavior in mice. When the mice were exposed to 4 h restricted feeding at night, all mice exhibited robust food anticipatory nose poking starting ~4 h before scheduled mealtime. When the light-dark cycle was advanced by 6 h, mice exhibited two distinct bouts of anticipatory poking, one corresponding to actual mealtime which continued at the same time of day, and one corresponding to predicted mealtime which shifted parallel with the light-dark cycle.

View Article and Find Full Text PDF
Article Synopsis
  • E93 is a crucial transcription factor in the metamorphosis process of the fruit fly Drosophila melanogaster, influencing its transition from larval to adult behavior and physiology.
  • A targeted RNAi screen identified E93, and further studies revealed that its knockdown affects key functions like appetite, metabolism, exercise endurance, and circadian rhythms, with specific impacts seen in GABA and MIP neurons.
  • The findings suggest that E93, in conjunction with signals from the Ecdysone Receptor, plays a vital role in coordinating metabolic processes and behavioral changes during the transition to adulthood.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how indoor environmental factors during pregnancy influence childhood eczema in Japan, aiming to fill knowledge gaps concerning this connection.
  • Using data from the Japan Environment and Children's Study, researchers analyzed responses from over 71,000 mother-child pairs, focusing on indoor conditions and eczema symptoms in children up to 3 years old.
  • Findings revealed that higher mold levels, gas heater use, parquet flooring, and frequent insecticide application significantly increase the risk of developing eczema, suggesting a need for updated WHO guidelines on indoor air quality to better protect child health.
View Article and Find Full Text PDF

Food-anticipatory nose poking is a unique food-seeking behavior driven by the food-entrainable oscillator. Here, we present a protocol to record a novel food-seeking nose poking behavior in mice under temporally restricted feeding followed by food deprivation using the open-source feeding experimentation device version 3 (FED3). We describe steps for setting up the FED3 and cage, training, and habituation.

View Article and Find Full Text PDF

Liquid-liquid phase separation (LLPS) underlies diverse biological processes. Because most LLPS studies were performed in vitro using recombinant proteins or in cells that overexpress protein, the physiological relevance of LLPS for endogenous protein is often unclear. PERIOD, the intrinsically disordered domain-rich proteins, are central mammalian circadian clock components and interact with other clock proteins in the core circadian negative feedback loop.

View Article and Find Full Text PDF

Emerging evidence has highlighted that the gut microbiota plays a critical role in the regulation of various aspects of mammalian physiology and behavior, including circadian rhythms. Circadian rhythms are fundamental behavioral and physiological processes that are governed by circadian pacemakers in the brain. Since mice are nocturnal, voluntary wheel running activity mostly occurs at night.

View Article and Find Full Text PDF

Teenage pregnancy increases the threat of depression because of its many factors. Pregnancy during young adulthood may also have several risk factors for depression compared to older pregnancies. However, data on depression in young adult pregnancies are lacking.

View Article and Find Full Text PDF

Liquid-liquid phase separation (LLPS) underlies diverse biological processes. Because most LLPS studies were performed in vitro or in cells that overexpress protein, the physiological relevance of LLPS is unclear. PERIOD proteins are central mammalian circadian clock components and interact with other clock proteins in the core circadian negative feedback loop.

View Article and Find Full Text PDF

A longstanding mystery in chronobiology is the location and molecular mechanism of the food-entrainable oscillator (FEO). The FEO is an enigmatic circadian pacemaker that controls food anticipatory activity (FAA). The FEO is implicated as a circadian oscillator that entrains to feeding time.

View Article and Find Full Text PDF

Background: Prenatal exposure to metallic elements may adversely affect early childhood health. However, more evidence is needed as population-based cohort studies are currently limited.

Objectives: We aimed to examine the associations between prenatal metallic (mercury, selenium, and manganese) exposure and the risk of allergic diseases in early childhood until three years of age.

View Article and Find Full Text PDF
Article Synopsis
  • Many female mammals, including rodents, have cyclical reproductive behaviors that are influenced by reproductive hormones and circadian rhythms.
  • Disruption in these circadian rhythms can negatively affect estrous cycles, leading to fewer pregnancies in mice.
  • Extending the length of daylight by just 2 hours can normalize estrous cycles in mice, suggesting that increasing light exposure may enhance reproductive success.
View Article and Find Full Text PDF

Purpose: Skin microvessels maintain temperature homeostasis by contracting and dilating upon exposure to changes in temperature. Under general anesthesia, surgical invasiveness, including incisions and coagulation, and the effects of anesthetics may cause variations in the threshold temperature, leading to the constriction and dilation of cutaneous blood vessels. Therefore, studies on skin microvascular circulation are necessary to develop appropriate interventions for complications during surgery.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to explore how maternal exposure to certain metallic elements (like lead and mercury) impacts the weight growth patterns of infants during their first three years.
  • It involved a large sample of over 100,000 pregnant women across Japan, tracking the growth of nearly 100,000 children from birth to age 3.
  • The results showed distinct weight trajectory groups among infants, with higher maternal levels of lead and selenium linked to poorer weight outcomes, while higher mercury levels appeared to have a protective effect against poor growth trajectories.
View Article and Find Full Text PDF
Article Synopsis
  • - The study examines the link between maternal exposure to particulate matter (PM) and the risk of developing gestational diabetes mellitus (GDM), particularly during the critical first trimester of pregnancy.
  • - Researchers analyzed data from the Japan Perinatal Registry Network, finding that exposure to total PM mass and organic carbon specifically during the first trimester was associated with a higher likelihood of GDM in a sample of over 82,000 women.
  • - This research is significant as it provides new evidence that early exposure to certain air pollutants may increase the risk of GDM, highlighting the need for further investigation into environmental factors influencing maternal health.
View Article and Find Full Text PDF

Ultradian rhythms in metabolism and physiology have been described previously in mammals. However, the underlying mechanisms for these rhythms are still elusive. Here, we report the discovery of temperature-sensitive ultradian rhythms in mammalian fibroblasts that are independent of both the cell cycle and the circadian clock.

View Article and Find Full Text PDF

The last 50 years have witnessed extraordinary discoveries in the field of circadian rhythms. However, there are still several mysteries that remain. One of these chronobiological mysteries is the circadian rhythm that is revealed by administration of stimulant drugs to rodents.

View Article and Find Full Text PDF

Rats housed in a 22-h light-dark cycle (11:11, T22) exhibit 2 distinct circadian locomotor activity (LMA) bouts simultaneously: one is entrained to the LD cycle and a second dissociated bout maintains a period greater than 24 h. These 2 activity bouts are associated with independent clock gene oscillations in the ventrolateral (vl-) and dorsomedial (dm-) suprachiasmatic nucleus (SCN), respectively. Previous results in our laboratory have shown that the vl- and dm-SCN oscillators are weakly coupled under T22 and that the period of the dissociated bout depends on coupling between the 2 subdivisions.

View Article and Find Full Text PDF

Neurodevelopmental delay is associated with neurodevelopmental disorders. Prenatal metal exposure can potentially cause neurodevelopmental delays in children. This study examines whether prenatal exposure to mercury (Hg) and selenium (Se) is associated with the risk of neurodevelopmental delays in children up to 4 years of age.

View Article and Find Full Text PDF

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal-recessive hereditary neuropathy causing congenital loss of pain sensation, thermoception, and perspiration. CIPA sometimes causes destructive spondyloarthropathy, the so-called Charcot spine, because of insensitivity to pain stimuli. Herein, we report a case of CIPA with severe spinal destruction treated by multiple spinal reconstructive surgeries and over 15 years of follow-up.

View Article and Find Full Text PDF

Metabolic syndrome and lumbar spinal stenosis (LSS) are common age-related diseases. However, the causal relationship between them remains unclear. This study aimed to identify the effects of LSS on metabolic syndrome incidence in community-dwelling adults.

View Article and Find Full Text PDF
Article Synopsis
  • * A nationwide study in Japan analyzed prenatal cadmium levels in mothers and assessed child development using standardized questionnaires to explore potential associations.
  • * The findings showed significant links between cadmium exposure and developmental delays at 6 months, 1 year, and 1.5 years, but these effects diminished by 2 years of age, suggesting that prenatal exposure can affect development early on but may lessen as children grow.
View Article and Find Full Text PDF