Passive mechanical features of single fibers from human muscle biopsies – effects of storage

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to investigate the effect of storage of human muscle biopsies on passive mechanical properties.</p> <p>Methods</p> <p>Stress-strain analysis accompanied by laser diffraction assisted sarcomere length measurement was performed on single muscle fibres from fresh samples and compared with single fibres from stored samples (-20°C, 4 weeks) with the same origin as the corresponding fresh sample. Basic morphological analysis, including cross sectional area (CSA) measurement, fibre diameter measurement, fibre occupancy calculation and overall morphology evaluation was done.</p> <p>Results</p> <p>Statistical analysis of tangent values in stress-strain curves, corresponding to the elastic modulus of single muscle fibres, did not differ when comparing fresh and stored samples from the same type of muscle. Regardless of the preparation procedure, no significant differences were found, neither in fibre diameter nor the relation between muscle fibres and extra-cellular matrix measured under light microscopy.</p> <p>Conclusion</p> <p>We conclude that muscle fibre structure and mechanics are relatively insensitive to the storage procedures used and that the different preparations are interchangeable without affecting passive mechanical properties. This provides a mobility of the method when harvesting muscle biopsies away from the laboratory.</p

Chemotactic factors in the human follicle at ovulation

Ovulation is initiated by the midcycle gonadotropin surge, which leads to a controlled degradation of the follicle wall ending in follicular rupture and oocyte extrusion. The gonadotropins triggers several biochemical and biophysical changes such as vascular alterations, increased proteolytic enzyme activity and leukocyte extravasation, within the preovulatory follicle. These events have several characteristics of an acute inflammatory reaction and ovulation is now looked upon as an inflammation-like process. A common phenomenon in inflammation is the gathering of leukocytes at the inflammatory site. In the ovary, leukocytes, especially neutrophils and macrophages, increase in numbers in the preovulatory follicle in response to the gonadotropin surge. Leukocytes may facilitate the events leading to follicular rupture at ovulation by their ability to secrete classical inflammatory/ovulatory mediators. The intra-ovarian signals causing this influx of leukocytes into the preovulatory follicle have been studied in more detail in the present study. The chemokines, a newly discovered group of chemotactic cytokines, have lately been given much attention for their specific roles in leukocyte migration and activation in inflammatory reactions and was therefore of interest as possible mediators of the ovulatory leukocyte influx. The specific aim of the present thesis were to investigate if some of these chemotactic factors, in particular the chemokines, were present in the human preovulatory follicle and if the synthesis was regulated by gonadotropins, steroids or cytokines. The concentrations of chemotactic factors in follicular fluid from preovulatory follicles of IVF-patients and follicular fluid at three stages of the natural cycle were studied. It was found that follicular fluid contained chemotactic properties of IL-8, GRO-a, MCP-1, CSF-1 and RANTES, but was devoid of the chemokine MIP-1a. The levels of the neutrophil attractant IL-8 in follicular fluid from natural cycles were increased at an early stage of the ovulatory process, while the macrophage attractants MCP-1 and CSF-1 increased at a later stage. Follicular fluid components may either be derived from the circulation or be secreted products from the follicular cells. To investigate the origin of the follicular fluid chemotactic factors, granulosa and theca cells from natural cycles were cultured and presence of chemotactic factors in conditioned media were studied. IL-8 originated from both granulosa and theca cells whereas MCP-1 and MIP-1a were more likely secretions from immune cells. The secretion of IL-8 by the granulosa cells was regulated by FSH and possibly by LH. The proinflammatory cytokines IL-1a and IL-1b were very potent in the induction of IL-8 and GRO-a secretion from follicular cells. Cultures of granulosa-lutein cells obtained from IVF cycles often contain a proportion of immune cells. In these cultures, MCP-1 was detected, indicating that immune cells contribute to the secretion of this chemokine in the ovulating follicle. In these cultures basal production of IL-8 and GRO-a but not RANTES was seen. In conclusion, the study shows that IL-8, GRO-a, MCP-1 and CSF-1 are expressed in the follicle and regulated by gonadotropins and cytokines. It is likely that they contribute to the migration and activation of leukocytes into the ovulating folllicle

Chemotactic factors in the human follicle at ovulation

Ovulation is initiated by the midcycle gonadotropin surge, which leads to a controlled degradation of the follicle wall ending in follicular rupture and oocyte extrusion. The gonadotropins triggers several biochemical and biophysical changes such as vascular alterations, increased proteolytic enzyme activity and leukocyte extravasation, within the preovulatory follicle. These events have several characteristics of an acute inflammatory reaction and ovulation is now looked upon as an inflammation-like process. A common phenomenon in inflammation is the gathering of leukocytes at the inflammatory site. In the ovary, leukocytes, especially neutrophils and macrophages, increase in numbers in the preovulatory follicle in response to the gonadotropin surge. Leukocytes may facilitate the events leading to follicular rupture at ovulation by their ability to secrete classical inflammatory/ovulatory mediators. The intra-ovarian signals causing this influx of leukocytes into the preovulatory follicle have been studied in more detail in the present study. The chemokines, a newly discovered group of chemotactic cytokines, have lately been given much attention for their specific roles in leukocyte migration and activation in inflammatory reactions and was therefore of interest as possible mediators of the ovulatory leukocyte influx. The specific aim of the present thesis were to investigate if some of these chemotactic factors, in particular the chemokines, were present in the human preovulatory follicle and if the synthesis was regulated by gonadotropins, steroids or cytokines. The concentrations of chemotactic factors in follicular fluid from preovulatory follicles of IVF-patients and follicular fluid at three stages of the natural cycle were studied. It was found that follicular fluid contained chemotactic properties of IL-8, GRO-a, MCP-1, CSF-1 and RANTES, but was devoid of the chemokine MIP-1a. The levels of the neutrophil attractant IL-8 in follicular fluid from natural cycles were increased at an early stage of the ovulatory process, while the macrophage attractants MCP-1 and CSF-1 increased at a later stage. Follicular fluid components may either be derived from the circulation or be secreted products from the follicular cells. To investigate the origin of the follicular fluid chemotactic factors, granulosa and theca cells from natural cycles were cultured and presence of chemotactic factors in conditioned media were studied. IL-8 originated from both granulosa and theca cells whereas MCP-1 and MIP-1a were more likely secretions from immune cells. The secretion of IL-8 by the granulosa cells was regulated by FSH and possibly by LH. The proinflammatory cytokines IL-1a and IL-1b were very potent in the induction of IL-8 and GRO-a secretion from follicular cells. Cultures of granulosa-lutein cells obtained from IVF cycles often contain a proportion of immune cells. In these cultures, MCP-1 was detected, indicating that immune cells contribute to the secretion of this chemokine in the ovulating follicle. In these cultures basal production of IL-8 and GRO-a but not RANTES was seen. In conclusion, the study shows that IL-8, GRO-a, MCP-1 and CSF-1 are expressed in the follicle and regulated by gonadotropins and cytokines. It is likely that they contribute to the migration and activation of leukocytes into the ovulating folllicle

Working with assets and setbacks : Operating room nurses' experiences of preserving the patients bodily integrity

I samband med operation exponeras patientens kropp för att kunna genomföra ett ingrepp och det är operationssjuksköterskans uppgift att bevara patientens kroppsliga integritet. Det finns dock inga tydliga riktlinjer för detta och kan vara en svår utmaning för operationssjuksköterskor. Syftet med studien var att beskriva operationssjuksköterskors erfarenheter av hur de bevarar patientens kroppsliga integritet. Kvalitativ ansats med intervjuer som datainsamlingsmetod valdes för att beskriva operationssjuksköterskors erfarenheter inom området. Urvalet bestod av nio operationssjuksköterskor fördelade på fyra sjukhus inom tre län. Datamaterialet analyserades enligt en kvalitativ innehållsanalys och resulterade i sju subkategorier under en och samma kategori. Operationssjuksköterskorna beskrev begreppet integritet som en människas personliga sfär och att varje enskild patients integritet bevaras genom individanpassad vård. Skydda patientens kroppsliga integritet kan göras genom att skyla kroppen och undvika obehöriga blickar, men samtidigt finns faktorer som försvårar bevarandet av patientens kroppsliga integritet. En kombination av professionalism och empati menar operationssjuksköterskorna leder dem till att bevara patientens kroppsliga integritet där patientrelationen är viktig men av olika skäl kan utebli. Slutsatsen av resultatet är att patientrelationen är viktig för att kunna inhämta den information operationssjuksköterskan behöver för att kunna bevara patientens kroppsliga integritet.During a surgery the patient’s body is exposed in order to carry out the surgery and it is the operating room nurse’s main task to care for and to protect the patient’s bodily integrity. However, at this time there are no clear guidelines on how to treat this subject and it can be a difficult challenge for the nurses. The purpose of this study was to describe the operating room nurses experiences of how they best protect the patient's bodily integrity. A qualitative approach with interviews and data collection methods was chosen to describe the operating room nurses' experiences in the field. The sample consisted of nine surgical nurses, spread across four hospitals in three counties. The data was analyzed according to a qualitative content analysis and resulted into seven sub-categories under the same category. Operating room nurses described the concept of integrity as a human's personal space, and that each patient’s integrity is maintained through individualized care. Protecting the patient’s bodily integrity can be done by covering the body and preventing unauthorized eyes but there are factors that can for different reasons make this difficult. The operating room nurses think that a combination of professionalism and empathy leads them to maintain the patient's bodily integrity where patient relationship is important, but for various reasons may be compromised. The conclusions from the result is that the patient relationship is important in order to obtain the information that the operating room nurse needs to be able to protect the patient's bodily integrity

Muscle biopsies from the supraspinatus in retracted rotator cuff tears respond normally to passive mechanical testing: a pilot study

PURPOSE: The aim of the present study was to assess the function of the isolated muscle component in retracted rotator cuff tears. METHODS: Muscle biopsies were harvested from the supraspinatus and the ipsilateral deltoid in seven patients undergoing surgery for a large, retracted rotator cuff tear. Single fibres and fibre bundles were subjected to passive stretching in vitro with subsequent recordings of tension and sarcomere lengths using the laser diffraction technique. Stress-strain curves were plotted, and the elastic modulus was calculated for all preparations. Morphology was evaluated with regard to collagen fraction, ratio between fast and slow fibres, fibre size and fibre size variability using standard staining techniques. RESULTS: Intra-individual comparisons of the stress-strain curves showed a high degree of conformity in terms of both shape and tangent values, and there were no statistically significant differences in the elastic modulus for single fibres and bundles in the deltoid and supraspinatus muscles, respectively, supported by the analysis of the observed confidence interval of the differences between the paired values of the elastic modulus. There were no differences in collagen content, fibre size and ratio between fast and slow fibres in the deltoid and supraspinatus muscles, respectively. CONCLUSION: We conclude that muscle biopsies from the supraspinatus in retracted rotator cuff tears respond normally to mechanical testing in vitro

Passive mechanical features of single fibers from human muscle biopsies – effects of storage-0

<p><b>Copyright information:</b></p><p>Taken from "Passive mechanical features of single fibers from human muscle biopsies – effects of storage"</p><p>http://www.josr-online.com/content/3/1/22</p><p>Journal of Orthopaedic Surgery and Research 2008;3():22-22.</p><p>Published online 7 Jun 2008</p><p>PMCID:PMC2432050.</p><p></p

Gonadotropin- and Cytokine-Regulated Expression of the Chemokine Interleukin 8 in the Human Preovulatory Follicle of the Menstrual Cycle¹

Interleukin 8 (IL-8) is a chemotactic cytokine involved in the recruitment and activation of neutrophils as well as in cell proliferation and angiogenesis. Because these events are essential components of folliculogenesis, ovulation, and subsequent repair of the ruptured follicle, the presence and regulation of IL-8 in the human follicle of the menstrual cycle was investigated. The concentrations of IL-8 were higher in follicular fluids from dominant follicles of late follicular/ovulatory phase compared with those of midfollicular phase. IL-8 was detected in the media from cultured granulosa and theca cells, with 10-fold higher levels in the theca cell cultures. Exposure to FSH and LH increased the IL-8 secretion from granulosa cells, but no effect was seen in theca cell cultures. Estradiol and progesterone did not affect IL-8 secretion from any cell type. The cytokines IL-1alpha and IL-1beta, but not tumor necrosis factor alpha, enhanced IL-8 secretion from both cell types. IL-8 levels in cultures of granulosa-lutein cells from hyperstimulated in vitro fertilization cycles were not affected by either gonadotropins or steroids. These data provide evidence that ovarian IL-8 is gonadotropin and cytokine induced and may be involved in the hormonally regulated stages of follicular development and ovulation

Nucleostemin- and Oct 3/4-positive stem/progenitor cells exhibit disparate anatomical and temporal expression during rat Achilles tendon healing

BACKGROUND: The recent discovery of residing tendon stem/progenitor cells has triggered a growing interest in stem cells as a useful tool in tendon repair. Our knowledge of their involvement in naturally healing tendons is, however, sparse. The aim of this study was to identify and determine stem/progenitor cells in relation to different healing phases and regions in a rat model of Achilles tendon rupture. METHODS: Surgery was performed to create a mid-tendon rupture on the right Achilles tendon of 24 rats, whereas the left tendon was used as a control. Tendons were harvested at one, two, eight and 17 weeks post-rupture and stained with antibodies specific to stem/progenitor cells (Octamer-binding transcription factor 3/4 (Oct 3/4) and nucleostemin), migrating cells (Dynamin 2 (Dyn 2)) and leukocytes (CD45). A histological examination was performed on sections stained with Alcian blue. RESULTS: At one and two weeks post-rupture, a large number of stem/progenitor cells were discovered throughout the tendon. Most of these cells were nucleostemin positive, whereas only a few Oct 3/4-positive cells were found, mainly situated inside the injury region (I region). At eight and 17 weeks, the increment in stem/progenitor cells had diminished to equal that in the control tendons. At all time points, Oct 3/4-positive cells were also found in the connective tissue surrounding the tendon and at the muscle-tendon junction in both ruptured and control tendons and were often seen at the same location as the migration marker, Dyn 2. CONCLUSIONS: The whole length of the Achilles tendon is infiltrated by stem/progenitor cells at early time points after a mid-tendon rupture. However, different stem/progenitor cell populations exhibit varying anatomical and temporal expressions during Achilles tendon healing, suggesting distinct reparative implications. Oct 3/4 may thus act as a more local, migrating stem/progenitor cell involved in injury-site-specific regenerative effects, as compared to the more general proliferative role of nucleostemin-positive stem/progenitor cells