scholarly journals Influence of acute and chronic streptozotocin-induced diabetes on the rat tendon extracellular matrix and mechanical properties

2015 ◽  
Vol 309 (9) ◽  
pp. R1135-R1143 ◽  
Author(s):  
Brent D. Volper ◽  
Richard T. Huynh ◽  
Kathryn A. Arthur ◽  
Joshua Noone ◽  
Benjamin D. Gordon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Patellar Tendon ◽  
Collagen Content ◽  
Control Group ◽  
Diabetic Patients ◽  
Insulin Group ◽  
Chronic Group ◽  
Acute Group ◽  
Streptozotocin Induced Diabetes

Diabetes is a major risk factor for tendinopathy, and tendon abnormalities are common in diabetic patients. The purpose of the present study was to evaluate the effect of streptozotocin (60 mg/kg)-induced diabetes and insulin therapy on tendon mechanical and cellular properties. Sprague-Dawley rats ( n = 40) were divided into the following four groups: nondiabetic (control), 1 wk of diabetes (acute), 10 wk of diabetes (chronic), and 10 wk of diabetes with insulin treatment (insulin). After 10 wk, Achilles tendon and tail fascicle mechanical properties were similar between groups ( P > 0.05). Cell density in the Achilles tendon was greater in the chronic group compared with the control and acute groups (control group: 7.8 ± 0.5 cells/100 μm2, acute group: 8.3 ± 0.4 cells/100 μm2, chronic group: 10.9 ± 0.9 cells/100 μm2, and insulin group: 9.2 ± 0.8 cells/100 μm2, P < 0.05). The density of proliferating cells in the Achilles tendon was greater in the chronic group compared with all other groups (control group: 0.025 ± 0.009 cells/100 μm2, acute group: 0.019 ± 0.005 cells/100 μm2, chronic group: 0.067 ± 0.015, and insulin group: 0.004 ± 0.004 cells/100 μm2, P < 0.05). Patellar tendon collagen content was ∼32% greater in the chronic and acute groups compared with the control or insulin groups (control group: 681 ± 63 μg collagen/mg dry wt, acute group: 938 ± 21 μg collagen/mg dry wt, chronic: 951 ± 52 μg collagen/mg dry wt, and insulin group: 596 ± 84 μg collagen/mg dry wt, P < 0.05). In contrast, patellar tendon hydroxylysyl pyridinoline cross linking and collagen fibril organization were unchanged by diabetes or insulin ( P > 0.05). Our findings suggest that 10 wk of streptozotocin-induced diabetes does not alter rat tendon mechanical properties even with an increase in collagen content. Future studies could attempt to further address the mechanisms contributing to the increase in tendon problems noted in diabetic patients, especially since our data suggest that hyperglycemia per se does not alter tendon mechanical properties.

scholarly journals Patellar and Achilles Tendon Stiffness in Elite Soccer Players Assessed Using Myotonometric Measurements

2019 ◽  
Vol 11 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Iver Cristi-Sánchez ◽  
Claudia Danes-Daetz ◽  
Alejandro Neira ◽  
Wilson Ferrada ◽  
Roberto Yáñez Díaz ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Patellar Tendon ◽  
Professional Training ◽  
Soccer Players ◽  
Patellar Tendinopathy ◽  
Control Group ◽  
Force Transmission ◽  
Level Of Evidence ◽  
Tendon Stiffness ◽  
Handheld Device

Background: Tendon overuse injuries are an issue in elite footballers (soccer players) and may affect tendon function. Achilles and patellar tendinopathy are the most frequent pathologies. Tendon stiffness, the relationship between the force applied to a tendon and the displacement exerted, may help represent tendon function. Stiffness is affected by training and pathology. Nevertheless, information regarding this mechanical property is lacking for elite soccer athletes. Hypothesis: Achilles and patellar tendon stiffness assessed using myotonometric measurements will be greater in elite soccer athletes than in control participants. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: Forty-nine elite soccer athletes and 49 control participants were evaluated during the 2017 preseason. A handheld device was used to measure Achilles and patellar tendon stiffness. Dominant and nondominant limbs were assessed for both groups. Results: A significantly stiffer patellar tendon was found for both the dominant and the nondominant limb in the elite soccer athletes compared with the control group. Nevertheless, no differences were found in Achilles tendon stiffness between groups. When comparing between playing positions in soccer athletes, no significant differences were found for both tendons. Conclusion: Greater patellar tendon stiffness may be related to an improvement in force transmission during muscle contraction. On the other hand, it seems that after years of professional training, Achilles tendon stiffness does not change, conserving the storing-releasing function of elastic energy. The nonsignificant differences between positions may be attributable to the years of homogeneous training that the players underwent. Clinical Relevance: The present study shows another technique for measuring mechanical properties of tendons in soccer athletes that could be used in clinical settings. In the future, this technique may help clinicians choose the best exercise protocol to address impairments in tendon stiffness.

scholarly journals Risk of Cancer Onset in Sub-Saharan Africans Affected with Chronic Gastrointestinal Parasitic Diseases

2005 ◽  
Vol 18 (3) ◽  
pp. 503-511 ◽  
Author(s):  
M. Waku ◽  
L. Napolitano ◽  
E. Clementini ◽  
T. Staniscia ◽  
C. Spagnolli ◽  
...  
Keyword(s):  
Intestinal Tuberculosis ◽  
Clinical History ◽  
Parasitic Infections ◽  
Control Group ◽  
Gi Tract ◽  
Chronic Group ◽  
Acute Group ◽  
Number Of Patients ◽  
History Of ◽  
Risk Of Cancer

Gastrointestinal Schistosomiasis and Amebiasis are uncommon in the western world, while such infections are frequent in the African community. In addition to the problems associated with the clinical symptoms of these parasitic infections, it is important to stress the increase in cancer of the Gastro-Intestinal (GI) tract. In this study we evaluate the prevalence of cancer in patients affected by chronic inflammatory diseases caused by the above named parasites. In three years, from January 2000 to December 2003, we observed a total of 1199 subject. Of these, 950 presented with complaints of diarrhoea, vomiting, abdominal pain, melena, hematemesis, rectal discharges and alteration of bowel habits. A total of 818 patients were evaluated in Uganda (Mulago and Arua hospitals) and 381 at Luisa Guidotti Hospital in Zimbabwe. An exhaustive clinical history was collected for each patient and then physical and laboratory examinations were performed. The clinical files of all patients previously admitted to the respective hospitals were obtained and the information taken from these files was then integrated with our clinical findings. Subjects who were found free of gastro-intestinal disease after examinations and did not have a clinical history of infective GI disease but presented with other pathologies, were regarded as control group. The control group was composed of 249 subjects. The subjects who were positive on examination underwent further investigations. The number of patients affected by schistosomiasis and amoebiasis were 221 and 224 respectivelly. The number of patients who suffered from aspecific enterocolitis was 454, intestinal tuberculosis was present in 21 patients and we found 30 patients with esophageal candidiasis. Patients who had the above mentioned GI diseases were then divided into 3 groups. First group was composed of patients who had a clinical history of infective GI diseases and were re-admitted for similar symptoms, and on examination were positive for the presence of the same infective GI diseases. Such patients were placed in the “Chronic group”. The second group was formed of patients who had previously undergone treatment for infective GI diseases but on re-admission were found free of infective GI disease, and this group was described as the “Cured group”. They had symptoms associated with other pathologies. A third group, which we described as the “Acute group” was composed of patients who did not have any previous case of GI infection and were admitted for the first time. Such patients were found positive on examination for infective GI diseases. In the 950 patients, we found a total of 45 tumors. The tumors were prevalent (42 tumours) in the chronic group. In 34 patients the tumor was in the colo-rectal region, in 3 patients in the stomach, in 4 patients in the oesophagus and 1 patient had cancer in the small bowel. Our results show a strong association between the chronic infection of the GI tract and the likelihood to develop tumours. However, it is not clear which biological mechanisms are implicated in such transformations. They may depend on the chronic inflammation of the GI mucous which permits the entrance of carcinogenic materials or on the effects of mutagenic products produced by the parasites or both.

Influence of Badminton Practice on Age-Related Changes in Patellar and Achilles Tendons

2020 ◽  
pp. 1-9
Author(s):  
Alfredo Bravo-Sánchez ◽  
Pablo Abián ◽  
Filipa Sousa ◽  
Fernando Jimenez ◽  
Javier Abián-Vicén
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Age Groups ◽  
Control Group ◽  
Physically Active ◽  
Tendon Stiffness ◽  
Sport Practice ◽  
Age Related ◽  
Age Related Changes

Regular sport practice could prevent age-related changes in tendinous tissues. The purpose of the study was to investigate the effect of regular badminton practice on patellar and Achilles tendon mechanical properties in senior competitive badminton players (>35 years old) and to compare the results with physically active people matched by age. One hundred ninety-two badminton players and 193 physically active people were divided by age into four groups, between 35 and 44 (U45), between 45 and 54 (U55), between 55 and 64 (U65), and over 65 (O65) years old. A LogiqS8 transducer in elastography mode and a MyotonPRO myotonometer were used to assess patellar and Achilles mechanical properties. Achilles tendon stiffness was higher in the control group than the badminton players for the U45, U55, and O65 age groups (p < .01). Also, the elastography index was higher in the control group than the badminton players for the U45, U55, U65, and O65 age groups (p < .05). In conclusion, regular badminton practice could prevent the decline in mechanical properties of the patellar and Achilles tendons.

scholarly journals Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6764 ◽  
Author(s):  
Amelie Werkhausen ◽  
Neil J. Cronin ◽  
Kirsten Albracht ◽  
Gøran Paulsen ◽  
Askild V. Larsen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Stance Phase ◽  
Training Group ◽  
Triceps Surae ◽  
Control Group ◽  
Tendon Stiffness ◽  
Strain Pattern ◽  
Tendon Strain ◽  
Triceps Surae Muscles

Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric single-leg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results Achilles tendon stiffness increased by 18% (P < 0.01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30% (P < 0.01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple in-series models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running.

scholarly journals Morphological Changes of Gingiva in Streptozotocin Diabetic Rats

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
C. Tesseromatis ◽  
A. Kotsiou ◽  
H. Parara ◽  
E. Vairaktaris ◽  
M. Tsamouri
Keyword(s):  
Diabetes Mellitus ◽  
Morphological Changes ◽  
Diabetic Rats ◽  
Control Group ◽  
Diabetic Patients ◽  
Histological Investigation ◽  
Bacterial Diseases ◽  
Male Wistar Rats ◽  
Streptozotocin Induced Diabetes ◽  
Routine Assay

Gingivitis and periodontitis are chronic bacterial diseases of the underlying and surrounding tooth tissues. Diabetes mellitus is responsible for tooth deprivation both by decay and periodontal disease. The streptozotocin-induced diabetes results in a diabetic status in experimental animals similar to that observed in diabetes patients. The aim of the study was to investigate the relationship between the gingival lesions and the microangiopathy changes in streptozotocin-induced diabetes mellitus. Forty male Wistar rats were divided into two groups (control and experimental). Diabetes mellitus was induced by 45 mg/kg IV streptozotocin. The histological investigation of the marginal gingival and the relevant gingival papilla showed inflammation of the lamina propria and the squamous epithelium as well as marked thickness of the arteriole in the diabetic group, but no changes were observed in the control group. The results suggested a probable application of a routine gingival histological investigation in diabetic patients in order to control the progress of disease complications. It may be concluded that histological gingival investigation can be used as a routine assay for the control of the diabetic disease and prevention of its complications.

Effects of the Frequency and Duration of Cyclic Stress on the Mechanical Properties of Cultured Collagen Fascicles From the Rabbit Patellar Tendon

2005 ◽  
Vol 127 (7) ◽  
pp. 1168-1175 ◽  
Author(s):  
Ei Yamamoto ◽  
Daisuke Kogawa ◽  
Susumu Tokura ◽  
Kozaburo Hayashi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Patellar Tendon ◽  
Load Condition ◽  
Peak Stress ◽  
Cyclic Stress ◽  
Control Group ◽  
Significant Difference

The effects of frequency or duration of cyclic stress on the mechanical properties of collagen fascicles were studied by means of in vitro tissue culture experiments. Collagen fascicles of approximately 300μm in diameter were obtained from rabbit patellar tendons. During culture, cyclic stress having the peak stress of approximately 2MPa was applied to the fascicles at 1Hz for 1hour∕day (1Hz-1h group), at 1Hz for 4hours∕day (1Hz-4h group), or at 4Hz for 1hour∕day (4Hz-1h group). The frequency of 4Hz and the duration of 1hour∕day are considered to be similar to those of the in vivo stress applied to fascicles in the intact rabbit patellar tendon. After culture for 1 or 2weeks, the mechanical properties of the fascicles were determined using a micro-tensile tester, and were compared to the properties of non-cultured, fresh fascicles (control group) and the fascicles cultured under no load condition (non-loaded group). The tangent modulus and tensile strength of fascicles in the 4Hz-1h group were similar to those in the control group; however, the fascicles of the 1Hz-1h and 1Hz-4h groups had significantly lower values than those of the control group. There was no significant difference in the tensile strength between the 1Hz-1h and non-loaded groups, although the strength in the 1Hz-4h group was significantly higher than that of the non-loaded group. It was concluded that the frequency and duration of cyclic stress significantly affect the mechanical properties of cultured collagen fascicles. If we apply cyclic stress having the frequency and duration which are experienced in vivo, the biomechanical properties are maintained at control, normal level. Lower frequencies or less cycles of applied force induce adverse effects.

Acoustic Radiation Force Impulse Elastography and Ultrasonographic Findings of Achilles Tendon in Patients With and Without Diabetic Peripheral Neuropathy: A Cross-Sectional Study

2019 ◽  
Author(s):  
Özlem İyidir ◽  
Feride Rahatlı ◽  
Yusuf Bozkuş ◽  
Lala Ramazanova ◽  
Hale Turnaoğlu ◽  
...  
Keyword(s):  
Peripheral Neuropathy ◽  
Achilles Tendon ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Acoustic Radiation Force Impulse ◽  
Control Group ◽  
Diabetic Patients ◽  
Group I ◽  
Group Ii

Abstract Aims We aimed to evaluate the elastographic features of Achilles tendon with Acoustic Radiation Force Impulse in patients with and without diabetic neuropathy. Methods According to the presence of peripheral neuropathy, 45 patients with type 2 diabetes were divided into 2 subgroups. Those with peripheral neuropathy were defined as group I (22 patients) and those without peripheral neuropathy were defined as group II (23 patients). A total of thirty age-, gender-, and body mass index-matched healthy individuals were selected as controls. All participants underwent both ultrasonographic and Acoustic Radiation Force Impulse elastographic examination in order to evaluate Achilles Tendon thickness and stiffness. Results Achilles tendon thicknesses were similar between groups (p=0.991). Achilles tendon thicknesses of both patient groups were significantly higher than the control group (group I vs control p=0.01; group II vs control p=0.006). Stiffness values of Achilles tendons were similar between the control group and group II (p=0.993). Shear Wave Velocity was significantly lower in group I than group IIand control group (p<0.001). Conclusion Diabetic patients with neuropathy have thicker and softer Achilles tendon while the elasticity of Achilles tendon in diabetic patients without neuropathy is similar to the healthy controls. Softening of the Achilles tendon may be an early sign of diabetic foot and reveal the patients with a risk of diabetic foot.

scholarly journals An experimental study of the mechanical properties of the Achilles tendon in rabbits during its recovery after injury

TRAUMA ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 12-19
Author(s):  
O.M. Khvisyuk ◽  
V.V. Pastukh ◽  
M.Yu. Karpinsky ◽  
O.D. Karpinska ◽  
I.A. Subbota
Keyword(s):  
Mechanical Properties ◽  
Hyaluronic Acid ◽  
Elastic Modulus ◽  
Achilles Tendon ◽  
Ultimate Strength ◽  
Tensile Load ◽  
Strength Properties ◽  
Control Group ◽  
Plastic Properties ◽  
Tendon Suture

Background. The problem of treating patients with tendon injuries remains unresolved. Unsatisfactory results after surgical treatment, according to different authors, range from 15 to 62 %. The functional outcome after surgical repair of damaged tendons is difficult to predict because of the high risk of scar block formation, which prevents them from sliding freely. Adhesions compromise the extensibility of the tendons, which in turn affects their strength. The purpose was to experimentally investigate the strength properties of the Achilles tendons after their surgical restoration with the further use of various medications. Materials and methods. The mechanical properties of the Achilles tendons of rabbits were investigated, on which a model of their partial damage was created by crossing by 1/2 the diameter. The injured tendon was sutured with a tendon suture. Within the experiment, 5 groups of preparations of the Achilles tendons of rabbits with a heel bone were studied, 3 preparations in each group. Group 1 was a control one. After performing the tendon suture, the wound was sutured. The rabbits of group 2 were administered Noltrex around the tendon suture. Group 3 included the animals who were injected with a preparation of hyaluronic acid. Group 4 consisted of the animals who were injected with lidase. Group 5 included the animals with the normal values, preparations of non-operated Achilles tendons of intact animals. All animals were withdrawn from the experiment on day 60. According to the test results, the value of the elastic modulus and the ultimate strength of the preparation was calculated. Results. The greatest elongation under a tensile load of 30 N was achieved on preparations of unoperated Achilles tendons of rabbits — 2.96 ± 0.22 mm. The smallest elongation was obtained for the preparations of the control group — 0.83 ± 0.37 mm. The rest of the drug groups showed intermediate values. The Achilles tendon preparations of rabbits from the control group (0.216 ± 0.123 MPa) have the highest value of the elastic modulus. The smallest value of the modulus of elasticity was found in the study of non-injured preparations of the Achilles tendon (0.051 ± 0.004 MPa). The drugs of the control group had the greatest strength (the value of the maximum permissible load was 81.81 ± 0.34 N). The least strength was demonstrated by preparations of non-traumatized Achilles tendons of rabbits (the value of the maximum permissible load was 69.72 ± 0.18 N). Conclusions. Within the recovery of the Achilles tendon in rabbits after injury, an increase in the values of indicators characterizing the strength properties of tissues is observed — elastic modulus, maximum permissible load, and ultimate strength. The values of indicators characterizing the plastic properties of tissues decrease, which can be one of the reasons for the development of post-traumatic contractures. The best indicators in terms of tissue plasticity were observed in the group of preparations of the Achilles tendon of rabbits treated with hyaluronic acid. The worst ones were registered in the control group.

Plyometric training effects on Achilles tendon stiffness and dissipative properties

2010 ◽  
Vol 109 (3) ◽  
pp. 849-854 ◽  
Author(s):  
Alexandre Fouré ◽  
Antoine Nordez ◽  
Christophe Cornu
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Qualitative Change ◽  
Control Group ◽  
Plyometric Training ◽  
Cross Sectional ◽  
Dissipation Coefficient ◽  
Before And After ◽  
Group A ◽  
Energy Dissipated

The aim of this study was to determine the effects of 14 wk of plyometric training on mechanical properties of the Achilles tendon. Nineteen subjects were randomly assigned to trained or control group. Cross-sectional area (CSA), stiffness, and dissipation coefficient of the Achilles tendon were measured before and after the training period. In the trained group, a decrease in dissipation coefficient (−35.0%; P < 0.05) and an upward trend in stiffness (+24.1%) of the Achilles tendon was found, without any changes in Achilles tendon CSA ( P > 0.05). Plyometric training enhances the muscular tension transmission mainly through a reduction in energy dissipated by the tendon. The lack of changes in the Achilles tendon CSA indicates that changes in mechanical properties would mainly result from a qualitative change in tendinous tissues rather than from changes in the geometry of the Achilles tendon.

The Effects of Common Anti-Inflammatory Drugs on the Healing Rat Patellar Tendon

2007 ◽  
Vol 35 (8) ◽  
pp. 1326-1333 ◽  
Author(s):  
Scott T. Ferry ◽  
Laurence E. Dahners ◽  
Hessam M. Afshari ◽  
Paul S. Weinhold
Keyword(s):  
Patellar Tendon ◽  
Maximum Load ◽  
Biomechanical Properties ◽  
Collagen Content ◽  
Acute Injury ◽  
Control Group ◽  
Sprague Dawley ◽  
Cox Inhibitors ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Background Tendon injuries that occur at the osteotendinous junction are commonly seen in clinical practice and range from acute strain to rupture. Nonsteroidal anti-inflammatory drugs are often prescribed in the treatment of these conditions, but the effect that these agents may have on the healing response at the bone-tendon junction is unclear. Hypothesis In response to an acute injury at the osteotendinous junction, the healing patellar tendon will have inferior biomechanical properties with administration of anti-inflammatory drugs as compared with acetaminophen and control. Study Design Controlled laboratory study. Methods A total of 215 Sprague-Dawley rats underwent transection of the patellar tendon at the inferior pole of the patella, which was subsequently stabilized with a cerclage suture. The animals were then randomized into 7 groups and administered 1 of the following analgesics for 14 days ibuprofen, acetaminophen, naproxen, piroxicam, celecoxib, valdecoxib, or control. At 14 days, all animals were sacrificed, and the extensor mechanism was isolated and loaded to failure. Biochemical analysis of the repair site tissue was performed. Animal activity throughout the study was monitored using a photoelectric sensor system. Results The control group demonstrated greater maximum load compared with the celecoxib, valdecoxib, and piroxicam groups (P < .05). The acetaminophen and ibuprofen groups were also significantly stronger than the celecoxib group (P < .05) but not statistically different than the control group. A total of 23 specimens had failure of the cerclage suture with the following distribution control (0/23), ibuprofen (0/23), acetaminophen (0/24), naproxen (3/24), piroxicam (4/24), celecoxib (6/22), and valdecoxib (10/24). The difference in distribution of the failures was significant (P < .001). Conclusions Anti-inflammatory drugs, with the exception of ibuprofen, had a detrimental effect on healing strength at the bone-tendon junction as demonstrated by decreased failure loads and increased failures of the cerclage suture. Acetaminophen had no effect on healing strength. The biomechanical properties paralleled closely with the total collagen content at the injury site, suggesting that these agents may alter healing strength by decreasing collagen content. Clinical Relevance Selective and nonselective cyclooxygenase (COX) inhibitors should be used judiciously in the acute period after injury or surgical repair at the bone-tendon junction.

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