Impact of the Ratio of Metabotropic and Ionotropic Components of Parasympathetic Action on the Excitability of a Urinary Bladder Smooth Muscle Cell: a Simulation Study

On a computer model of a smooth muscle cell (SMC) of the urinary bladder detrusor (UBD) having a corresponding set of ion channels and intracellular signaling mechanisms, we investigated the influence of ionotropic (purine, P) and metabotropic (muscarinic, M) components of the parasympathetic stimulus on the membrane potential of the cell and Ca²⁺ concentration inside it ([Ca²⁺]_i). The P and M components of the stimulus were simulated, respectively, by the increasing conductivity of P2X receptor channels of the SMC membrane (G _P2X) and the permeability of calcium channels of the sarcoplasmic reticulum activated by inositol triphosphate (P _IP3), considering that IP3 is the end product of the metabotropic chain starting from the M3 cholinergic receptors. The G _P2X and P _IP3 values, latent periods (LPs) of their activation, and relations of the above parameters were chosen in such a mode that application of a single stimulus evoked the SMC response with the P and M components close to those of the prototype. The normal magnitude and LP of the M component of the concentration response (calcium transient) were significantly greater than the respective parameters of the P component; the M component was accompanied by generation of an action potential (AP) with after-processes analogous to those of the prototype. A decrease in the P _IP3 simulating a deficiency of M3 receptors observed under a few pathological conditions led to a decrease in the electric and concentration SMC responses, down to full elimination of AP generation and changes in [Са²⁺]_i. Under such conditions, a significant increase in the G _P2X could provide a [Са²⁺]_i increase to a nearly normal level. Using paired parasympathetic stimulation with different interstimulus intervals, ΔТ, allowed us to obtain a situation where the M response to the first stimulus (M1) was preceded by the P response to the second stimulus (P2) with a short adjustable interval. The use of such stimulation with certain values of the ΔТ and conductivity of purinergic channels G _P2X can compensate for the attenuation of the M component, due to interaction of the latter with the P component caused by the second stimulus. Thus, pathological attenuation of the M component of the parasympathetic stimulation effect can be compensated in clinical practice (at least partly) by applying purinomimetics and/or paired stimulation.

from Physiology via xlomafota13 on Inoreader http://ift.tt/1tvJTgV


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1Yrw3Ym
via IFTTT

Electrophysiological Indices in Sportsmen: Correlations with the Contents of Iron and Copper in the Organism

Using the roentgen-fluorescent analysis, we found mostly below-norm contents of iron and copper in stable tissue samples (hairs) of 18- to 20-year-old sportsmen (university students). Correlations of the results of such analysis with sets of indices characterizing the state of the CNS (parameters of background EEG and of evoked/event-related EEG potentials), that of the cardiovascular system (CVS, data of electrocardiography and rheography), and of the mechanisms providing autonomic regulation of the latter system (indices of cardiointervalography) were calculated. According to the number of significant correlations (0.44 < r < 0.56) and their intensity, we found that the content of copper is more significant for the indices characterizing functioning of the CNS, especially for those of EEG phenomena related to mental processes. At the same time, the content of iron exerts more significant influences on the functional state of the CVS. It should be taken into account that the pattern of correlations found in our study is typical of a relatively specific sampling of the subjects (with a clearly pronounced deficiency of the above-mentioned elements in the organism) and can be dissimilar in the case of normal (and, especially, increased) contents of these metals.

from Physiology via xlomafota13 on Inoreader http://ift.tt/1XoXTVN


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1rpDlPd
via IFTTT

Stress-Induced Increases in Levels of Caspases in the Prefrontal Cortex in a Rat Model of PTSD

We investigated the levels of expression of caspase-3 and 9 in the medial prefrontal cortex (mPFC) of rats subjected to single prolonged stress (SPS) to provide a novel insight into the mechanism of how this cortical region is related to post-traumatic stress disorder (PTSD). Fifty male Wistar rats were divided into the control group and four SPS groups examined at days 1, 4, 7, and 14 after treatment. Expression of caspase-3 in SPS groups was significantly greater when compared with the control group (P < 0.05) and peaked at day 7 after exposure to SPS. In the control group, the intensity of fluorescence of caspase-9-positive cells was low, while that in the SPS groups was significantly higher (P < 0.01) and peaked at day 4 after exposure to SPS. After SPS episodes, levels of mRNA of caspase-3 and caspase-9, compared with those in the control group, gradually increased and peaked at days 7 and 4, respectively (P < 0.01). Therefore, changes of expression of caspase-9 and caspase-3 may play an important role in the pathogenesis of PTSD.

from Physiology via xlomafota13 on Inoreader http://ift.tt/1tvJTO1


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1Yrvu0L
via IFTTT

Posttraumatic Stress Disorder (PTSD): Mechanisms and Possible Treatments

Posttraumatic stress disorder (PTSD) is a debilitating mental condition occurring after a tragedy or a traumatic experience, such as rape, assault, natural disasters, war, car or plane accidents, etc. PSTD can cause a number of symptoms, such as fear, high anxiety, hyperarousal, bad dreams, nightmares, etc., existing for a long time after the traumatic event. In recent years, the spread of PTSD has increased in the world, especially in Asia (Middle East), particularly among soldiers who have taken part in military conflicts. This situation confirms the importance of understanding how PTSD develops and of improving its treatment. This paper is a review of the literature related to the respective topics. Like other anxiety disorders, PTSD is related to disruption of the endocrine system, particularly disintegration of the hypothalamus-pituitary-adrenal axis (HPAA). People suffering from PTSD are characterized by elevated levels of corticotropin-releasing hormone, low basal cortisol levels, and enhanced negative feedback suppression of the HPAA. At the present time, certain plant-derived compounds are considered to be a new important source to treat PTSD. For example, remedies obtained from saffron are such possible means. According to our findings, saffron components may considerably affect some parts of the HPAA for reduction of stress-induced corticosterone release.

from Physiology via xlomafota13 on Inoreader http://ift.tt/1XoXdQb


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1rpEg23
via IFTTT

Anatomical basis and design of the distally based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone: a cadaveric dissection.

Related Articles

Anatomical basis and design of the distally based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone: a cadaveric dissection.

Surg Radiol Anat. 2016 Jun 13;

Authors: Wang T, Lin J, Song D, Zheng H, Hou C, Li L, Wu Z

Abstract
BACKGROUND: Detailed investigation of the vasculature of the lateral aspect of the foot has rarely been presented. However, harvesting the flap in this area to cover defects of the foot and hand is highly important. Repair of soft-tissue defects at the forefoot remains a challenge in reconstructive surgery. This study explores the characteristics of the distal-based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone to establish a repair procedure for ulcers or defects in the forefoot region.
METHODS: This study is divided into two parts: anatomical study and simulated operation. Thirty cadavers were utilized in the anatomical study after arterial injection. The tuberosity of the fifth metatarsal bone was used as the anatomical landmark. The lateral plantar artery perforator of the fifth metatarsal bone was identified through dissection. The perforators were dissected under a microscope. The details of the lateral plantar artery perforators, the distribution of the lateral dorsal cutaneous nerve and lateral plantar vein, the anastomosis in the lateral plantar artery perforator of the fifth metatarsal bone, the nutrient vessels of the lateral dorsal cutaneous nerve and lateral plantar vein, and other arteries of the lateral foot were recorded. The flap-raising procedure was performed on three fresh cadavers.
RESULTS: The lateral dorsal cutaneous nerve originated from sural nerve, traveled obliquely downward along the anterior lateral margin of the foot, and accompanied by the lateral plantar vein after bifurcation, and was eventually distributed on the lateral aspect of the foot. The nutrifying arteries to the lateral dorsal cutaneous nerve and lateral plantar vein were present segmentally and mainly originated from the lateral plantar artery perforator of the fifth metatarsal bone. These nitrifying arteries constantly originated from the lateral plantar artery in the area of tuberosity of the fifth metatarsal, ran along the medial side of the fifth metatarsal, traveled between the fifth metatarsal bone and the lateral muscle group (the flexor digitorum brevis and the abductor digiti minimi muscles), pierced the aponeurosis, vascularized the skin of the anterior lateral plantar region, and resulted in many minute branches, which anastomosed with the lateral tarsal artery and fourth dorsal metatarsal artery. The anatomical study showed that (1) the vasculature pattern can roughly be classified into three types and (2) constant anastomoses occurred between the above-mentioned arteries in the lateral-dorsum region of the foot.
CONCLUSION: A reliable large- or medium-sized neuro-venocutaneous flap with lateral dorsal cutaneous nerve, lateral plantar vein, and nutrient vessels can be raised using only the perforator of the lateral plantar artery of the fifth metatarsal bone, which is thin, is in the immediate vicinity of the forefoot, and has a reliable retrograde blood supply. This flap can be considered an alternative means to reconstruct soft-tissue defects of the forefoot.

PMID: 27294973 [PubMed - as supplied by publisher]

http://ift.tt/1Usbt8J


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/28BmGtP
via IFTTT

Bicipital tuberosity bone characteristics in surgical reattachment of the distal biceps: anatomical and radiological study.

Related Articles

Bicipital tuberosity bone characteristics in surgical reattachment of the distal biceps: anatomical and radiological study.

Surg Radiol Anat. 2016 Jun 13;

Authors: Lázaro-Amorós A, Tomás-Batlle X, Ballesteros-Betancourt J, Guillermo JR, Gómez-Bonsfills X, de la Vall XC, Llusà-Pérez M

Abstract
PURPOSE: The aim of this study was to measure the cortical thickness and bone density of the different parts of the bicipital tuberosity, to evaluate the importance of these variables on resistance to pulling out of distal biceps tendon reinsertion implants.
METHODS: Sixteen cadaveric arms were used for this study. A multiple detector computed tomography was performed in each proximal radius. Bone thickness and density of anterior, posterior cortex and anterior trabecular bone were measured in proximal, medial and distal parts of the bicipital tuberosity. Statistical and concordance analyses of results were performed.
RESULTS: In our specimens, the medial and distal parts of the anterior cortex and the anterior trabecular bone were thicker, mean 11.3 mm SD 2.72 and 11.17 mm SD 3.05, with a significant difference when compared to the proximal part; mean 10.3 mm SD 2.35, of radial tuberosity. The three posterior segments where all thicker compared to the anterior cortex (proximal 3.15 SD 1.31; medial 3.33 SD 1.5; distal 3.34 SD 1.43 mm), but without statistical differences between them. The measured bone density was equivalent in the three portions of the anterior cortex and trabecular bone [proximal 1924.63 SD 547.22; medial 1848.19 SD 538.59; distal 2100.47 SD 396.32 Hounsfield units (HU)]. The posterior cortex was denser compared to the anterior cortex and the anterior trabecular bone in all the segments (proximal 1962.63 SD 223.57; medial 1907.16 SD 232.08; distal 1987.06 SD 189.12 HU), but without statistical differences between the three parts.
CONCLUSIONS: Based on the results of this anatomic study which have demonstrated that anterior cortex and anterior trabecular bone of the medial and distal regions of the bicipital tuberosity are thicker than proximal part, we postulate that these segments could give better pulling out resistance to monocortical implants. Our findings suggest that the strongest parts of the bicipital tuberosity are the proximal and medial parts of the posterior cortex. We can afford them drilling across the radius using a bicortical implant in the proximal and medial section of the radial tuberosity. Furthermore, we suggest that an increased margin of safety could be achieved to prevent injury to the posterior interosseous nerve, drilling the cortical hole in the proximal part of the radial tuberosity without losing resistance properties.

PMID: 27294837 [PubMed - as supplied by publisher]

http://ift.tt/1UsbWaQ


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1S3KcU2
via IFTTT

Psychosocial morbidity in women with abnormal cervical cytology managed by cytological surveillance or initial colposcopy: longitudinal analysis from the TOMBOLA randomised trial

Abstract

Objective

To compare psychosocial outcomes (follow-up related worries and satisfaction with follow-up related information and support) over 30 months of two alternative management policies for women with low-grade abnormal cervical cytology.

Methods

Women aged 20–59 years with low-grade cytological abnormalities detected in the National Health Service Cervical Screening Programme were randomised to cytological surveillance or initial colposcopy. A total of 3399 women who completed psychosocial questionnaires at recruitment were invited to complete questionnaires at 12, 18, 24 and 30 months. Linear mixed models were used to investigate differences between arms in the two psychosocial outcomes. Each outcome had a maximum score of 100, and higher scores represented higher psychosocial morbidity.

Results

On average, over 30 months, women randomised to colposcopy scored 2.5 points (95%CI −3.6 to −1.3) lower for follow-up related worries than women randomised to cytological surveillance. Women in the colposcopy arm also scored significantly lower for follow-up related satisfaction with information and support (−2.4; −3.3 to −1.4) over 30 months. For both outcomes, the average difference between arms was greatest at 12th- and 18th-month time points. These differences remained when the analysis was stratified by post-school education.

Conclusions

Women with low-grade cytology, irrespective of their management, have substantial initial psychosocial morbidity that reduces over time. Implementation of newer screening strategies, which include surveillance, such as primary HPV screening, need to consider the information and support provided to women. © 2016 The Authors. Psycho-Oncology published by John Wiley & Sons Ltd.

from Cancer via ola Kala on Inoreader http://ift.tt/1to58AT
via IFTTT

from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/1Xn5Evi
via IFTTT