Biochemical Interaction Between Muscle and Bone: A Physiological Reality?

In elderly with a sedentary lifestyle, often suffering from sarcopenia to osteopenia, a training intervention could be an effective countermeasure for bone as well as muscle. Both bone and muscle adapt their mass and strength in response to mechanical loading in part via similar signaling pathways. Bone as well as muscle produces a wide variety of growth factors and cytokines in response to mechanical loading, which are important for their adaptations. It has been hypothesized that in addition to mechanical stimuli, muscle and bone communicate by these factors. Whether such biochemical interaction between both tissues is physiological is a still subject of debate. Here, we provide an overview of a range of biological factors possibly involved in the biochemical cross talk between bone and muscle. In addition, we discuss the plausibility that such interactions are involved in non-pathological adaptation of both tissues, either in paracrine or in endocrine fashion. As yet, convincing experimental evidence for biochemical cross talk between muscle and bone is very limited. Several studies have shown that muscle-derived factors are involved in bone fracture healing as well as in bone adaptation in case of muscle pathology. For involvement of cross talk between muscle and bone in physiological adaptation, there is no definite proof yet. Detailed knowledge of the biochemical interactions between muscle and bone is of clinical importance. It can help to discover pharmacological treatment to be used alone or in parallel with exercise training, thereby reducing the need for high-impact exercise.     

Laughter as a social rejection cue: Gelotophobia and transient cardiac responses to other persons' laughter and insult

Other persons' laughter, normally perceived as a signal that persons are friendly and inviting others to approach, can also be perceived as a cue of social rejection. In this study, prerecorded laughter was placed in a realistic and personally relevant context, and participants' responses were related to gelotophobia, a trait predisposing to perceiving laughter as a cue of social rejection. Individuals with gelotophobia showed marked heart rate deceleration in response to the laughter stimulus, possibly indicating a “freezing‐like” response. Moreover, cardiac responses to anger provocation by overtly insulting statements indicated heightened aggressive anger in response to cumulated social threat. The study adds to recent research showing specific cardiac responses to social rejection and to the literature on social rejection sensitivity by demonstrating the value of using well interpretable physiological measures in this research context.     

Ulcerated plaques of the aorta as a cause of ischaemic stroke

Stroke is a second cause of mortality worldwide and a leading cause of acquired disability in adults. Approximately 20% of all ischaemic strokes are of cardioembolic origin. We present a case of a 60-year-old man with a history of stroke without changes in carotid and vertebral arteries. Echocardiography exam revealed patent foramen ovale (PFO) and abnormal echos in the aorta that were verified as advanced complex atheromas by computed tomography. Due to small size PFO was deemed insignificant and the source of embolism were most probably aortic atheromas. Patient was put on acenocumarol, aspirin and statin.     

Hand preference,magical thinking and left–right confusion

Several reports suggest a significant correlation between hand preference quotients and Magical Ideation Scale (MIS) scores, such that individuals with mixed prefer ences have higher MIS scores. In a sample of 156 male and 257 female undergraduate university students no significant correlation was found between MIS scores and hand preference; hand preference being defined in numerous ways, and using short and long hand preference questionnaires to assess handedness. An index of left–right confusion was significantly related to MIS score, but only in females. We suggest that the role of subjects' response style and general approach to filling out questionnaires should be fully explored before “neurological” causes of links between hand preference and other questionnaire‐assessed behavioural variables are invoked.     

A Sensitive Microtitre Plate Enzyme Immunoassay of Oestradiol-17β in the Cow and Mare

Abstract

Microtitre plates were coated with antiserum against oest-radiol-17β-6-(0-carboxymethyl)-oxime bovine serum albumin raised in sheep. The plasma samples (0.2–1.0 ml) were extracted with peroxide-free dlethyl ether prepared daily by treatment with Al₂O₃. The enzyme conjugate was prepared by coupling oestradiol-17β-6-(0-carboxymethyl)-oxime to horse-radish peroxidase. The conjugate was chromatographed on a Sephadex G-25 column. The standard curve ranged from 0.37 to 18.40 fmol/well of oestradiol-17β. The amount of oestradiol-17β causing a 50% reduction of maximum binding was 4.4 fmol/well.

Standards and samples were Incubated overnight at 4°C. The conjugate solution was added followed by further incubation for 2 h at 4°C. Tetramethylbenzidine was used as a chromogen, and the optical density was measured at 450 nm. The patterns of oestradiol-17β during a normal oestrus cycle in the cow and mare are presented.