Background: Type 1 diabetes (T1D) is a chronic condition in which the body produces too little insulin, a hormone needed to regulate blood glucose. Various factors such as carbohydrates, exercise, and hormones impact insulin needs. Beyond carbohydrates, most factors remain underexplored.
View Article and Find Full Text PDFProgress in mechanobiology allowed us to better understand the important role of mechanical forces in the regulation of biological processes. Space research in the field of life sciences clearly showed that gravity plays a crucial role in biological processes. The space environment offers the unique opportunity to carry out experiments without gravity, helping us not only to understand the effects of gravitational alterations on biological systems but also the mechanisms underlying mechanoperception and cell/tissue response to mechanical and gravitational stresses.
View Article and Find Full Text PDFCementum, the tissue attaching mammal tooth roots to the periodontal ligament, grows appositionally throughout life, displaying a series of circum-annual incremental features. These have been studied for decades as a direct record of chronological lifespan. The majority of previous studies on cementum have used traditional thin-section histological methods to image and analyse increments.
View Article and Find Full Text PDFBack pain is a common condition with a high social impact and represents a global health burden. Intervertebral disc disease (IVDD) is one of the major causes of back pain; no therapeutics are currently available to reverse this disease. The impact of bone mineral density (BMD) on IVDD has been controversial, with some studies suggesting osteoporosis as causative for IVDD and others suggesting it as protective for IVDD.
View Article and Find Full Text PDFObjectives: Dimorphism in the dentition has been observed in human populations worldwide. However, research has largely focused on traditional linear crown measurements. As imaging systems, such as micro-computed tomography (micro-CT), become increasingly more accessible, new dental measurements such as dental tissue size and proportions can be obtained.
View Article and Find Full Text PDFCementum is a mineralized dental tissue common to mammals that grows throughout life, following a seasonally appositional rhythm. Each year, one thick translucent increment and one thin opaque increment is deposited, offering a near-complete record of an animal's life history. Male and female mammals exhibit significant differences in oral health, due to the contrasting effects of female versus male sex hormones.
View Article and Find Full Text PDFDespite considerable advances in knowledge of the anatomy, ecology and evolution of early mammals, far less is known about their physiology. Evidence is contradictory concerning the timing and fossil groups in which mammalian endothermy arose. To determine the state of metabolic evolution in two of the earliest stem-mammals, the Early Jurassic Morganucodon and Kuehneotherium, we use separate proxies for basal and maximum metabolic rate.
View Article and Find Full Text PDFThe spine is the central skeletal support structure in vertebrates consisting of repeated units of bone, the vertebrae, separated by intervertebral discs (IVDs) that enable the movement of the spine. Spinal pathologies such as idiopathic back pain, vertebral compression fractures and IVD failure affect millions of people worldwide. Animal models can help us to understand the disease process, and zebrafish are increasingly used as they are highly genetically tractable, their spines are axially loaded like humans, and they show similar pathologies to humans during ageing.
View Article and Find Full Text PDFThe Golgi is the cellular hub for complex glycosylation, controlling accurate processing of complex proteoglycans, receptors, ligands and glycolipids. Its structure and organisation are dependent on golgins, which tether cisternal membranes and incoming transport vesicles. Here, we show that knockout of the largest golgin, giantin, leads to substantial changes in gene expression but only limited effects on Golgi structure.
View Article and Find Full Text PDFAnimals use sound for communication, with high-amplitude signals being selected for attracting mates or deterring rivals. High amplitudes are attained by employing primary resonators in sound-producing structures to amplify the signal (e.g.
View Article and Find Full Text PDFThe ear of the bush-cricket, Copiphora gorgonensis, consists of a system of paired eardrums (tympana) on each foreleg. In these insects, the ear is backed by an air-filled tube, the acoustic trachea (AT), which transfers sound from the prothoracic acoustic spiracle to the internal side of the eardrums. Both surfaces of the eardrums of this auditory system are exposed to sound, making it a directionally sensitive pressure difference receiver.
View Article and Find Full Text PDFOsteoarthritis (OA) is the most common joint disorder, characterised by focal loss of cartilage and increased subchondral bone remodelling at early OA stages of the disease. We have investigated the temporal and the spatial relationship between bone remodelling in subchondral bone plate (Sbp) and trabecular bone (Tb) in Dunkin Hartley (DH, develop OA early) and the Bristol Strain 2 (BS2, control which develop OA late) guinea pigs. Right tibias were dissected from six male animals of each strain, at 10, 16, 24 and 30 weeks of age.
View Article and Find Full Text PDFSpine (Phila Pa 1976)
August 2015
Study Design: Mechanical and microcomputed tomography (micro-CT) study of cadaver spines.
Objective: To compare porosity and thickness of vertebral endplates with (1) compressive stresses measured in adjacent intervertebral discs and (2) grade of disc degeneration.
Summary Of Background Data: Endplate porosity is important for disc metabolite transport, and yet porosity increases with age and disc degeneration.
The present study describes a new juvenile hominin mandible and teeth and a new juvenile humerus from level V of the GP2 gallery of Cova del Gegant (Spain). The mandible (Gegant-5) preserves a portion of the right mandibular corpus from the M1 distally to the socket for the dc mesially, and the age at death is estimated as 4.5-5.
View Article and Find Full Text PDFThe origin and radiation of mammals are key events in the history of life, with fossils placing the origin at 220 million years ago, in the Late Triassic period. The earliest mammals, representing the first 50 million years of their evolution and including the most basal taxa, are widely considered to be generalized insectivores. This implies that the first phase of the mammalian radiation--associated with the appearance in the fossil record of important innovations such as heterodont dentition, diphyodonty and the dentary-squamosal jaw joint--was decoupled from ecomorphological diversification.
View Article and Find Full Text PDFOsteoarthritis (OA) is the most common joint disorder characterised by bone remodelling and cartilage degradation and associated with chondrocyte apoptosis. These processes were investigated at 10, 16, 24, and 30 weeks in Dunkin Hartley (DH) and Bristol Strain 2 (BS2) guinea pigs that develop OA spontaneously. Both strains had a more pronounced chondrocyte apoptosis, cartilage degradation, and subchondral bone changes in the medial than the lateral side of the tibia, and between strains, the changes were always greater and faster in DH than BS2.
View Article and Find Full Text PDFAm J Phys Anthropol
March 2013
Dental wear patterns were recorded on 458 deciduous molar teeth, of 142 subadults from late medieval (AD 1086-1539) England, to explore the relationship between dental wear and burial status of children. A new ordinal method for scoring dental wear stages on the deciduous molar teeth was devised. It was postulated that if a discernible relationship between dental wear stage and burial location could be seen then this could reflect a difference in diet between those receiving higher or lower status burial.
View Article and Find Full Text PDFIn mammals, hearing is dependent on three canonical processing stages: (i) an eardrum collecting sound, (ii) a middle ear impedance converter, and (iii) a cochlear frequency analyzer. Here, we show that some insects, such as rainforest katydids, possess equivalent biophysical mechanisms for auditory processing. Although katydid ears are among the smallest in all organisms, these ears perform the crucial stage of air-to-liquid impedance conversion and signal amplification, with the use of a distinct tympanal lever system.
View Article and Find Full Text PDFInt J Paleopathol
March 2012
A description of the late mediaeval skeleton (AD 1150-1539) of a young child with probable signs of tuberculosis is presented. This individual was recovered along with one hundred and ninety skeletons from the cemetery of the priory of SS Peter and Paul, Taunton, Somerset. Aged between three and five years old at death, these remains present a variety of lesions on the cranium, ribs, cervical vertebrae and femora, some of which are highly suggestive of tuberculosis.
View Article and Find Full Text PDFAn experimental technique for quantifying load-sharing in cadaveric spines is used to test the hypothesis that degenerative changes in human apophyseal joints are directly related to high levels of compressive load-bearing by these joints. About 36 cadaveric thoraco-lumbar motion segments aged 64-92 years were subjected to a compressive load of 1.5 kN.
View Article and Find Full Text PDFRotator cuff disease represents the most common cause of modern shoulder pain and disability. Much of the clinical literature on rotator cuff disease focuses on subacromial impingement and supraspinatus tendinopathy, although other patterns of lesions are also recognised. Rotator cuff disease has received relatively little attention in palaeopathological literature, but signs relating to subacromial impingement have been reported.
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