The Correlations between Handgrip Strength and Several Psychosomatic Features in Homo Sapiens – a Review

Síla stisku ruky je velmi dobrým ukazatelem zdraví, výkonnosti kosterního svalstva a celkově je dobrým indikátorem zdravotního stavu a vitality. Testosteron je hormon, který je primárně zodpovědný za rozvoj sekundárních pohlavních znaků a zároveň má silný vztah k tělesné síle a zevním ukazatelům rozvoje skeletální svaloviny. Byla publikována řada prací, které poukazují na úzký vztah mezi testosteronem a agresí. Nebyl však doposud vysvětlen kauzální vztah mezi hladinou testosteronu a výsledným agresivním chováním, tedy konkrétní působení metabolitů testosteronu v specifických oblastech mozku. Na základě publikovaných experimentálních prací jsou diskutována některá možná/částečná vysvětlení působení testosteronu na vznik agresivního chování. Dále je diskutován vztah mezi silou stisku ruky a lidským sexuálním chováním – tedy sexuální dimorfismus v síle stisku, ženská percepce (v rozdílných fázích menstruačního cykly) stisku ruky u mužů a volba partnera ve vztahu k jeho fitness (jak je hodnocena dle síly stisku ruky, jež je dobrým ukazatelem hladiny testosteronu).Handgrip strength (HGS) is a very good marker of physical health, good muscle performance and an overall indicator of health status and vitality. Testosterone, as a hormone primarily responsible for secondary sexual traits development, is also strongly correlated to body strength and somatic features which represent it. It has been widely reported that testosterone correlates with aggression. However, the pathway of testosterone metabolites in specific brain regions, or cause and effect formula of testosterone level and aggression has not been satisfactorily explained. Several possible and/or partial explanations based on published experiments are discussed. Furthermore, the relation between HGS and human sexual behavior is discussed – the sexual dimorphism in HGS, the perception of male HGS by females at different stages of the menstrual cycle and the selection of a partner with respect to his fitness (as estimated by HGS which is a good indicator of testosterone level)

Sidabro genas: substrato C- terminalinio išplėtimo ekspresija ir analizė naudojant MALDI-TOF masių spektrometriją

Neuropeptides are peptides used by neurons for cell communication. Neuropeptides are produced from inactive larger precursor (prepropeptides). Prepropeptides are further processed to become active peptides. Carboxypeptidases, which are one class of enzymes involved in neuropeptide processing, have functions in cleaving off C-terminal amino acid residues. There are two known carboxypeptidases in Drosophila melanogaster carboxypeptidase M and D. Out of the two, only carboxypeptidase D is known to be expressed in the nervous system, which makes it an important candidate for the neuropeptide processing in Drosophila. However this has never been tested thoroughly / rigorously by using MALDI-TOF mass spectrometry. Drosophila silver (svr) gene codes for carboxypeptidase D. The mutation in svr gene ends up with lethality. As hypothesis, this mutation may block further peptide processing at C-terminal amino acid residues so active peptide cannot be synthesized. To investigate this, first task would be to rescue flies. We used heat-shock promotor line to rescue transgenic svrPG33 mutant line. After rescue flies second task would be to investigate expression of carboxypeptidase D in Drosophila nervous system by using immunohistochemistry. After then, third task would be to stop the processing of peptide from propeptide by blocking carboxypeptidase D in Drosophila. Finally, if our hypothesis is correct, we should determine inactive neuropeptides with C-terminal extension by using MALDI-TOF mass spectrometry. The heat-shock promotor line has been working, and we have got rescued flies. Immunohistochemistry staining has shown that carboxypeptidase D has broadly expressed in nerve cell of both brain and ventral nerve cord and as well as endocrine cells. By Using MALDI-TOF mass spectrometry, C-terminally extended 33 peptides have been found in this study. In conclusion, our outcomes suggest that Drosophila CPD is a main carboxypeptidase in nerve cell of both brain and central nerve cord and in endocrine cells in Drosophila melanogaster.Karboksipeptidazės D (CPD) dar yra žinoma kaip metalokarboksipeptidazės D yra fermentai kurie atlieka nuo didesnių pirmtakų molekulių, prepeptidų, atskelia C-galą. Žinduolių grupėje, CPE ir CPD, kurios priklauso N/E pošeimiui, yra pagrindinės karboksipeptidazės. Skirtingai nuo to vaisinė muselė turi tik du CP narius, CPD ir CPM. Pagal ankstesnius tyrimus, CPD yra pagrindinė karboksipeptidazė reikalinga vaisinės muselės išgyvenamumui. Atsižvelgiant į visą šią informaciją, vaisinės muselės CPD funkciškai gali atitikti žinduolių karboksipeptidazes E ir D, tačiau iki šiol niekas neištyrė šios hipotezės. Drozofilose karboksipeptidzė koduojama srv genu.Šio geno mutacijos yra letalinės. Tyrimams naudojome transgeninės svrPG33 linijos mutantinės muselės, kur srv genas gali būti suaktyvantas temperatūriu šoku. Norint ištirti iškeltą hipotezę, buvo stebėta ar transgeninės svrPG33 linijos mutantinės muselės išgyvena po terminio šoko. Taip pat immunohistocheminiais metodais CPD raiška Drozofilos nervinėje sistemoje. Galiausiai, tirta, ar temperatūrinių šoku nepaveiktose transgeninėse mutantinėse muselėse galime nustatyti neaktyvius neuropeptidus su C-galu. Iš mūsų pateiktų rezultatų matyti, kad vaisinės muselės CPD yra pagrindinė nervinių ląstelių karboksipeptidazė esanti smegenyse, centriniame nervų mazge ir endokrininėse ląstelėse. Naudodami MALDI-TOF masių spektroskopiją nustatėme 33 peptidus su nepašalintu C-galu.Biologijos katedraGamtos mokslų fakultetasVytauto Didžiojo universiteta

Design of semi-automated calibration system for pressure balances

In this study, a digital manometer was used as a transfer standard to perform calibration of a pneumatic pressure balance. The same pressure balance was calibrated with the cross-floating method based on falling rate determination (FRD). Average of differences among the effective area results show an agreement of less than 10 ppm between the digital manometer-assisted calibration (DMAC) method and the FRD method. The method in which a digital pressure gauge is used as a transfer standard not only facilitates calibration but also enables the automation of pressure balance calibration. Full automation of pressure balance calibration requires an automatic mass loading system for both the reference instrument and the device under test. Since there is a lot of different kinds of pressure balances, it is nearly impossible for a pressure metrology laboratory to have an automatic mass-handler system for every type of pressure balance. Therefore, a more efficient way in which automated mass-handler systems are not required .., a semi-automatic calibration system, is designed. For that purpose, two different calibration procedures, increasing-decreasing cycles, and pressurize-vent (P-V) procedures are performed and compared. The equivalence of procedure results makes the semi-automated calibration design of pressure balances possible. The most distinguishing advantages of a semi-automated calibration system are the applicability to any type of pressure balance and low cost compared to full automation

Location of the internal carotid artery and ophthalmic artery segments for non-invasive intracranial pressure measurement by multi-depth TCD

The aim of the present study was to locate the ophthalmic artery by using the edge of the internal carotid artery (ICA) as the reference depth to perform a reliable non-invasive intracranial pressure measurement via a multi-depth transcranial Doppler device and to then determine the positions and angles of an ultrasonic transducer (UT) on the closed eyelid in the case of located segments. High tension glaucoma (HTG) patients and healthy volunteers (HVs) undergoing non-invasive intracranial pressure measurement were selected for this prospective study. The depth of the edge of the ICA was identified, followed by a selection of the depths of the IOA and EOA segments. The positions and angles of the UT on the closed eyelid were measured. The mean depth of the identified ICA edge for HTG patients was 64.3 mm and was 63.0 mm for HVs (p = 0.21). The mean depth of the selected IOA segment for HTG patients was 59.2 mm and 59.3 mm for HVs (p = 0.91). The mean depth of the selected EOA segment for HTG patients was 48.5 mm and 49.8 mm for HVs (p = 0.14). The difference in the located depths of the segments between groups was not statistically significant. The results showed a significant difference in the measured UT angles in the case of the identified edge of the ICA and selected ophthalmic artery segments (p = 0.0002). We demonstrated that locating the IOA and EOA segments can be achieved using the edge of the ICA as a reference point

Improvement of dynamic pressure standard for calibration of dynamic pressure transducers

In dynamic pressure measurement phenomena, dynamic pressure calibration of the measurement chain including a pressure sensor, signal conditioning amplifier and data acquisition part is required. A drop mass dynamic calibration machine which is used for the dynamic calibration in hydraulic media was designed and developed. This study presents a research study and measurement results on the dynamic calibration of pressure transducers by using the newly developed machine

Prospective clinical study of non-invasive intracranial pressure measurements in open-angle glaucoma patients and healthy subjects

Background and Objective: Glaucoma is a progressive optic neuropathy in which the optic nerve is damaged. The optic nerve is exposed not only to intraocular pressure (IOP) in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Here, we analyse ICP differences between patients with glaucoma and healthy subjects (HSs). Materials and Methods: Ninety-five patients with normal-tension glaucoma (NTG), 60 patients with high-tension glaucoma (HTG), and 62 HSs were included in the prospective clinical study, and ICP was measured non-invasively by two-depth transcranial Doppler (TCD). Results: The mean ICP of NTG patients (9.42 ± 2.83 mmHg) was significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p = 0.007). The mean ICP of HTG patients (8.11 ± 2.68 mmHg) was significantly lower than that of NTG patients (9.42 ± 2.83 mmHg) (p = 0.008) and significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p < 0.001). Conclusions: An abnormal ICP value could be one of the many influential factors in the optic nerve degeneration of NTG patients and should be considered as such instead of just being regarded as a “low ICP"

Intraorbital pressure-volume characteristics in a piglet model: In vivo pilot study.

Intracranial pressure measurement is frequently used for diagnosis in neurocritical care but cannot always accurately predict neurological deterioration. Intracranial compliance plays a significant role in maintaining cerebral blood flow, cerebral perfusion pressure, and intracranial pressure. This study's objective was to investigate the feasibility of transferring external pressure into the eye orbit in a large-animal model while maintaining a clinically acceptable pressure gradient between intraorbital and external pressures. The experimental system comprised a specifically designed pressure applicator that can be placed and tightly fastened onto the eye. A pressure chamber made from thin, elastic, non-allergenic film was attached to the lower part of the applicator and placed in contact with the eyelid and surrounding tissues of piglets' eyeballs. External pressure was increased from 0 to 20 mmHg with steps of 1 mmHg, from 20 to 30 mmHg with steps of 2 mmHg, and from 30 to 50 mmHg with steps of 5 mmHg. An invasive pressure sensor was used to measure intraorbital pressure directly. An equation was derived from measured intraorbital and external pressures (intraorbital pressure = 0.82 × external pressure + 3.12) and demonstrated that external pressure can be linearly transferred to orbit tissues with a bias (systematic error) of 3.12 mmHg. This is close to the initial intraorbital pressure within the range of pressures tested. We determined the relationship between intraorbital compliance and externally applied pressure. Our findings indicate that intraorbital compliance can be controlled across a wide range of 1.55 to 0.15 ml/mmHg. We observed that external pressure transfer into the orbit can be achieved while maintaining a clinically acceptable pressure gradient between intraorbital and external pressures

Can the treatment of normal-pressure hydrocephalus induce normal-tension glaucoma? A narrative review of a current knowledge

Ventriculoperitoneal shunt placement is the most commonly used treatment of normal-pressure hydrocephalus (NPH). It has been hypothesized that normal-tension glaucoma (NTG) is caused by the treatment of NPH by using the shunt to reduce intracranial pressure (ICP). The aim of this study is to review the literature published regarding this hypothesis and to emphasize the need for neuro-ophthalmic follow-up for the concerned patients. The source literature was selected from the results of an online PubMed search, using the keywords “hydrocephalus glaucoma” and “normal-tension glaucoma shunt”. One prospective study on adults, one prospective study on children, two retrospective studies on adults and children, two case reports, three review papers including medical hypotheses, and one prospective study on monkeys were identified. Hypothesis about the association between the treatment of NPH using the shunt to reduce ICP and the development of NTG were supported in all reviewed papers. This suggests that a safe lower limit of ICP for neurological patients, especially shunt‑treated NPH patients, should be kept. Thus, we proposed to modify the paradigm of safe upper ICP threshold recommended in neurosurgery and neurology into the paradigm of safe ICP corridor applicable in neurology and ophthalmology, especially for shunt-treated hydrocephalic and glaucoma patients

Graphical and statistical analyses of the oculocardiac reflex during a non-invasive intracranial pressure measurement

Purpose. This study aimed to examine the incidence of the oculocardiac reflex during a non-invasive intracranial pressure measurement when gradual external pressure was applied to the orbital tissues and eye. Methods. Patients (n = 101) and healthy volunteers (n = 56) aged 20–75 years who underwent a non-invasive intracranial pressure measurement were included in this retrospective oculocardiac reflex analysis. Prespecified thresholds greater than a 10% or 20% decrease in the heart rate from baseline were used to determine the incidence of the oculocardiac reflex. Results. None of the subjects had a greater than 20% decrease in heart rate from baseline. Four subjects had a greater than 10% decrease in heart rate from baseline, representing 0.9% of the total pressure steps. Three of these subjects were healthy volunteers, and one was a glaucoma patient. Conclusion. The incidence of the oculocardiac reflex during a non-invasive intracranial pressure measurement procedure was very low and not associated with any clinically relevant effects

Typical heart rate variation.

<p>(A) A heart rate variation in a healthy volunteer. (B) A pressure increase of 4 mmHg per pressure Pe(t) step (time period of approximately 30 sec each) was used on the ocular globe from 0 mmHg to 48 mmHg.</p