The Contribution of the Perichondrium to the Structural Mechanical Behavior of the Costal-Cartilage

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Jason L. Forman ◽  
Eduardo del Pozo de Dios ◽  
Carlos Arregui Dalmases ◽  
Richard W. Kent
Keyword(s):  
Mechanical Behavior ◽  
Computational Models ◽  
Costal Cartilage ◽  
Test Method ◽  
Homogeneous Material ◽  
Reaction Forces ◽  
Student’S T ◽  
Anterior Posterior ◽  
Student’S T Test

The costal-cartilage in the human ribcage is a composite structure consisting of a cartilage substance surrounded by a fibrous, tendonlike perichondrium. Current computational models of the human ribcage represent the costal-cartilage as a homogeneous material, with no consideration for the mechanical contributions of the perichondrium. This study sought to investigate the role of the perichondrium in the structural mechanical behavior of the costal-cartilage. Twenty-two specimens of postmortem human costal-cartilage were subjected to cantileveredlike loading both with the perichondrium intact and with the perichondrium removed. The test method was chosen to approximate the cartilage loading that occurs when a concentrated, posteriorly directed load is applied to the midsternum. The removal of the perichondrium resulted in a statistically significant (two-tailed Student’s t-test, p≤0.05) decrease of approximately 47% (95% C.I. of 35–58%) in the peak anterior-posterior reaction forces generated during the tests. When tested with the perichondrium removed, the specimens also exhibited failure in the cartilage substance in the regions that experienced tension from bending. These results suggest that the perichondrium does contribute significantly to the stiffness and strength of the costal-cartilage structure under this type loading, and should be accounted for in computational models of the thorax and ribcage.

FIBRINOPEPTIDE B6 15-42 IN LIVER CIRRHOSIS: A SENSITIVE INDICATOR OF MILD FIBRINOLYSIS ACTIVATION

1987 ◽  
Author(s):  
F Marongiu ◽  
M R Acca ◽  
G Mulas ◽  
M Conti ◽  
G Sorano ◽  
...  
Keyword(s):  
Liver Cirrhosis ◽  
Plasminogen Activators ◽  
Fibrinopeptide A ◽  
A Posteriori ◽  
Plasmin Activity ◽  
Coagulation Activation ◽  
Cirrhotic Patients ◽  
Student’S T ◽  
Student’S T Test

In order to detect even minimal fibrinolysis activation in liver cirrhosis and to investigate whether an increased plasmin activity is related to a mild blood coagulation activation, we measured fibrinopeptide A (FPA) (Mailinckrodt) and fibrinopeptide BB 15-42 (BB 15-42) (IMCO and SORIN Biomedica) in 26 patients (16 men and 10 women, mean age 55.8 ± 13.1 years) with histologically proven liver cirrhosis..Mann-Whitney test, Student’s t test and correlation coefficient r were employed for statistical analysis when appropriate.FPA and BB 15-42 were not normal distributed and thus their levels were exprsessed as median and range.FPA values were significantly different in cirrhotic patients (3.9, 0.9-24.2 ng/ml) from those of the controls (2.5, 0.5-3.9 ng/ml) (p < 0.01).BB 15-42 levels were significantly higher in cirrhotic patients (19.4, 7.1-103.1 ng/ml) than in controls (10.4, 5.1-15.4 ng/ml) (p < 0.01). A posteriori the patients were divided in two subgroups according to whether their FPA levels were high (subgroup 1, n=10, FPA>4.0 ng/ml) or normal (subgroup 2, n=16, FPA < 4.0 ng/ml).In patients with high FPA levels we found higher levels of BB 15-42 (22.2, 9.9-103.1 ng/ml) than in patients with normal FPA (13.6, 7.1-30.7 ng/ml ).Thvis difference was significant (p < 0.02) .There was no relationship between FPA and BB 15-42.Our data indicate that in liver cirrhosis a mild fibrinolysis activation may occur.The role of a chronic intravascular coagulation appears to be significant in this regard.However the impaired clearance of plasminogen activators, the decreased synthesis of fibrinolysis inhibitors and the decreased levels of hystidine rich glycoprotein may be also involved in determining fibrinolysis activation as suggested by the lack of correlation between FPA and BB 15-42.

Uraemic Bleeding : Contributory Role Of Red Cells

1981 ◽  
Author(s):  
M Livio ◽  
D Marchesi ◽  
G Mecca ◽  
G Remuzzi ◽  
M B Donati ◽  
...  
Keyword(s):  
Blood Cell ◽  
Cell Volume ◽  
Negative Correlation ◽  
Packed Cell Volume ◽  
Significant Negative Correlation ◽  
T Test ◽  
Red Cells ◽  
Student’S T ◽  
Student’S T Test

The bleeding times (B.T.) of 65 patients with chronic uraemia were determined inmediately before a routine haonodialysis session. A significant negative correlation (r=0.67, p < 0.01) was found between B.T. and packed cell volume (PCV) values. When the patients with bleeding times longer than 15 min were excluded frcm the analysis, a negative correlation with PCV was still apparent (r = 0.55; p<0.01 ) .in addition, X2 analysis showed a significant association between PCV values <30% and B.T. longer than 260 sec(p<0.001) . Fourteen uraemic patients with PC/ values between 13% and 27% and B.T. longer than 15 min, required washed blood cell transfusions, after which PCV values increased variably but no shortening of B.T. was observed unless PCV rose to at least 30%. In particular, 2 uraemic patients with B.T. >15 min and PCV values of 21% and 19% were transfused on several occasions. PCV rose to 23%, 30% and 35% in the first patient and to 25% and 34% in the second one. The corresponding B.T. were >15 min,>15 min and 0 min 30 sec and > 15 and 9 min 30 sec. In a group of 15 patients with uraemia-unrelated anemias (PCV between 20% and 34%) the median B.T. was 300 sec (range 120-450 sec) whereas in a group of 15 uraemic patients with comparable PCV values, the median B.T. was 390 sec (range 180 - 900 sec) (p<0.05, paired student's t test) . It is concluded that among other factors red cells may contribute to the defective haemostasis in uraemic patients.

Brain tumors: Regulation of angiogenesis.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e13540-e13540 ◽  
Author(s):  
Eduard Evgenevich Rostorguev ◽  
Elena Mikhaylovna Frantsiyants ◽  
Yulia A. Pogorelova ◽  
Natalia D. Cheryarina ◽  
Larisa Kozlova ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Test Results ◽  
Metastatic Brain Tumors ◽  
Metastatic Tissue ◽  
Pathological Angiogenesis ◽  
Important Mediator ◽  
Student’S T ◽  
G 14 ◽  
Student’S T Test

e13540 Background: Cancer implicates pathological angiogenesis. The problem of treatment for primary and metastatic brain tumors is still unsolved. In addition to main angiogenic functions, VEGF family performs important mediator functions in the immune system. The role of VEGF family in central nervous system tumors is poorly studied. Our purpose was to study the levels of factors of angio- and lymphangiogenesis in tissues of glioblastomas (G), brain metastases (MTS), meningiomas and corresponding peritumoral area. Methods: Tissues of tumor and peritumoral zone (PZ) obtained during the surgery from 22 patients with G, 14 patients with brain MTS from breast cancer and 12 meningioma patients, mean age 39.2±4.8 years, were studied. Levels of VEGF-A, VEGFR-1, VEGF-C and VEGFR-3 were determined by ELISA. The data were processed using Statistica 10 program. The significance of differences was determined by Student's t-test. Results: VEGF-A levels in tissues of G and MTS were higher than in meningioma tissues by 74.7 and 94.5 times, respectively; levels of VEGF-R1 were 2.7 and 3.9 higher, and the VEGF-A/VEGF-R1 coefficient was 28.1 and 24.1 times higher, respectively. Levels of VEGF-C and VEGF-R3 were escalated only in G tissues compared to meningiomas (by 1.7 times on average). The VEGF-С/VEGF-R3 coefficient was similar in all studied tumors. VEGF-A levels were higher in PZ of G and MTS compared to PZ of meningiomas – by 78.2 and 110.7 times, respectively, while VEGF-R1 level was higher in G PZ only (by 5.5 times). The VEGF-A/VEGF-R1 coefficient was 14.5 and 128.5 times higher, respectively. VEGF-C level in PZ of G was escalated compared to meningiomas by 6.5 times, in MTS – by 1.6 times. VEGFR-3 contents did not differ significantly in all PZ samples, but the VEGF-С/VEGF-R3 coefficient was higher in PZ in G by 9 times and in MTS by 2 times. Conclusions: Compared to benign meningiomas, angio- and lymphangiogenesis are activated in glioblastoma tissue and angiogenesis – in metastatic tissue. Lymphangiogenesis is more active in peritumoral zone of glioblastomas compared to metastatic tissue, and angiogenesis is more active in peritumoral zone of metastases.

The Role of the Non-Collagenous Extracellular Matrix in Tendon and Ligament Mechanical Behavior: A Review

2021 ◽  
Author(s):  
Lainie E. Eisner ◽  
Ryan Rosario ◽  
Nelly Andarawis-Puri ◽  
Ellen M. Arruda
Keyword(s):  
Extracellular Matrix ◽  
Mechanical Behavior ◽  
Computational Models ◽  
Matrix Protein ◽  
Fiber Direction ◽  
Future Studies ◽  
Tissue Repair And Regeneration ◽  
Resistance To Deformation ◽  
Theoretical Mechanics

Abstract Tendon is a connective tissue that transmits loads from muscle to bone, while ligament is a similar tissue that stabilizes joint articulation by connecting bone to bone. 70-90% of tendon and ligament's extracellular matrix (ECM) is composed of a hierarchical collagen structure that provides resistance to deformation primarily in the fiber direction, and the remaining fraction consists of a variety of non-collagenous proteins, proteoglycans, and glycosaminoglycans (GAGs) whose mechanical roles are not well characterized. ECM elements such as elastin, the proteoglycans decorin, biglycan, lumican, fibromodulin, lubricin, and aggrecan and their associated GAGs, and Cartilage Oligomeric Matrix Protein (COMP) have been suggested to contribute to tendon and ligament's characteristic quasi-static and viscoelastic mechanical behavior in tension, shear, and compression. The purpose of this review is to summarize existing literature regarding the contribution of the non-collagenous ECM to tendon and ligament mechanics, and to highlight key gaps in knowledge that future studies may address. Using insights from theoretical mechanics and biology, we discuss the role of the non-collagenous ECM in quasi-static and viscoelastic tensile, compressive, and shear behavior in the fiber direction and orthogonal to the fiber direction. We also address the efficacy of tools that are commonly used to assess these relationships, including enzymatic degradation, mouse knockout models, and computational models. Further work in this field will foster a better understanding of tendon and ligament damage and healing as well as inform strategies for tissue repair and regeneration.

scholarly journals Circulating levels of ghrelin in human fetuses

2003 ◽  
pp. 111-116 ◽  
Author(s):  
D Cortelazzi ◽  
V Cappiello ◽  
PS Morpurgo ◽  
S Ronzoni ◽  
MS Nobile De Santis ◽  
...  
Keyword(s):  
Gestational Age ◽  
Venous Blood ◽  
Elective Cesarean Section ◽  
Intrauterine Development ◽  
Elective Cesarean ◽  
Appropriate For Gestational Age ◽  
Student’S T ◽  
Circulating Levels ◽  
Student’S T Test

OBJECTIVE: Ghrelin is a GH secretagog isolated recently from rat stomach and involved in the stimulation of food intake and adiposity in rodents and humans. Moreover, subsequent studies showed that ghrelin is expressed in rat and human placenta, suggesting a possible influence of the peptide on fetal growth. The aim of this study was to evaluate circulating levels of ghrelin in appropriate for gestational age (AGA) or intrauterine growth-restricted (IUGR) fetuses. SUBJECTS AND METHODS: Ghrelin levels between 20 and 39 weeks of gestation were measured in 16 AGA and nine IUGR fetuses in whom blood was collected by cordocentesis performed for prenatal diagnosis of different diseases or during elective cesarean section. In most samples, GH, cortisol and leptin levels were also evaluated. Results are expressed as means+/-S.D. Differences were tested using the Student's t-test with Welch correction. P<0.05 was considered significant. RESULTS: All fetuses showed levels of ghrelin in the umbilical venous blood (100+/-99 pmol/l) that did not correlate with the gestational age or the maternal ghrelin levels. No difference was found between umbilical venous and arterial concentrations, suggesting that fetal tIssues are a source of ghrelin. Ghrelin levels in IUGR fetuses were significantly higher than those found in AGA fetuses (176+/-125 vs 58+/-44 pmol/l; P<0.005). Moreover, in samples obtained at birth, ghrelin concentrations correlated negatively with birth weight (P<0.05). In IUGR fetuses, GH and cortisol concentrations were higher and leptin levels lower than in AGA fetuses, although no significant correlation between these parameters and ghrelin levels was found. CONCLUSION: The presence of ghrelin in the fetal circulation as well as its increase in IUGR fetuses suggest a role of this peptide during intrauterine development.

scholarly journals ATTENUATION OF HEAVY METALS IN SEDIMENTS OF THE BONNY ESTUARY, NIGERIA: THE ROLE OF OXYGEN

2013 ◽  
Vol 9 (1) ◽  
pp. 1810-1821
Author(s):  
Dr. Dike Henry Ogbuagu ◽  
Dagogo Eras Dinney
Keyword(s):  
Pearson Correlation ◽  
Aerobic Condition ◽  
Significant Heterogeneity ◽  
Anaerobic Conditions ◽  
Student’S T ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions ◽  
Student’S T Test ◽  
Analyze Data

Sediments of the Bonny Estuary, which is repository to pollutants from various industrial and shipment activities in its catchment was investigated for rate of natural attenuation of toxic metals (Cd, Mn, Cr, Pb, Cu, Ni, Fe) under aerobic and anaerobic conditions. Samples were collected with pre-grab sampler from seabed, sieved in the laboratory and monitored under aerobic and anaerobic conditions. After incubation at 18°C, harvests were made on days 1, 14, 28 and 42 and levels of the metals determined spectrophotometrically. Variation plots, ANOVA, Means plots, Student’s t-test and Pearson correlation (r) were used to analyze data. Concentration reductions were higher in aerobic condition in the order Cu(15.5%)> Cd(11.4%)> Fe(8.0%)>Mn(5.7%)> Cr(4.4%)> Ni(4.2%)>Pb(3.9%) than in anaerobic condition which was in the order Cu(7.5%)> Cd(7.4%)>Pb(2.4%)>Mn/Cr(1.8% each)> Fe(0.9%)> Ni(0.5%). There was significant heterogeneity in metals reductions (Sig. F=0.000) on all the harvest days, especially of Cu, Pb and Fe at P<0.05. Attenuation of Mn also differed markedly between the aerobic and anaerobic conditions (Sig. t=0.005) at the 95% confidence interval. pH influenced the attenuation of Ni (r=0.766) and Fe (r=0.795) (P<0.05) as well as Cd (r=0.968), Cr (r=0.861), Pb (r=0.989) and Cu (r=0.950) (P<0.01). Results indicate that rate of attenuation was slow and slightly enhanced by oxygenation.

RESPONSE OF TURMERIC EXPLANT ON CYTOKININ AND AUXIN IN MURASHIGE AND SKOOG

2019 ◽  
Vol 24 (1) ◽  
pp. 1-12
Author(s):  
Mita Indriani ◽  
Erni Suminar ◽  
Noladhi Wicaksana ◽  
Denny Sobardini ◽  
Sulistyaningsih Sulistyaningsih ◽  
...  
Keyword(s):  
Tissue Culture ◽  
T Test ◽  
Test Method ◽  
Seed Technology ◽  
Planting Material ◽  
Randomized Design ◽  
Student’S T ◽  
And Control ◽  
Student’S T Test

This study was aimed at determining the concentration of several types of cytokinins and auxin for the induction of turmeric shoots in vitro. The research was conducted at the Tissue Culture Seed Technology Laboratory, Faculty of Agriculture, Padjadjaran University, Jatinangor. The study was conducted from October 2017 to February 2018. The source of planting material is in the form of shoots from the turmeric rhizome. The source of explants or planting material came from the field collected at the Tissue Culture Seed Technology Laboratory, Faculty of Agriculture, Padjadjaran University. Explants were taken from rhizome buds with a size of 0.6-2.0 cm. The experiment used a Completely Randomized Design which was analyzed using the Student’s T-test method. The number of experimental and control groups in this study were seven groups. Variation in treatment with different BAP, thidiazuron, zeatin, and NAA concentrations in each group. The results show that Thidiazuron 1 mgL-1 + NAA 1 mgL-1 gives better results on the percentage of live explants and number of shoots on turmeric plants (Curcuma domestica Val.) Clones 41 at the age of 14 weeks after planting.RESPONS EKSPLAN KUNYIT PADA SITOKININ DAN AUKSIN DALAM MEDIA MURASHIGE DAN SKOOGPenelitian ini bertujuan untuk mendapatkan salah satu konsentrasi dari beberapa jenis sitokinin dan auksin untuk induksi tunas kunyit secara in vitro. Penelitian dilakukan di Laboratorium Kultur Jaringan Teknologi Benih, Fakultas Pertanian, Universitas Padjadjaran, Jatinangor. Waktu pelaksanaan penelitian ini dimulai pada awal bulan Oktober 2017 sampai bulan Februari 2018. Sumber bahan tanam berupa tunas dari rimpang tanaman kunyit. Sumber eksplan atau bahan tanam berasal dari lapangan yang dikoleksi di Laboratorium Kultur Jaringan Teknologi Benih, Fakultas Pertanian, Universitas Padjadjaran. Eksplan diambil dari mata tunas rimpang dengan ukuran 0,6-2,0 cm. Percobaan menggunakan Rancangan Acak Lengkap yang dianalisis menggunakan metode Student’s T-test. Jumlah kelompok eksperimen dan kontrol dalam penelitian ini adalah tujuh kelompok. Variasi perlakuan dengan penambahan konsentrasi BAP, thidiazuron, zeatin, dan NAA yang berbeda pada setiap kelompok. Hasil penelitian ini menunjukkan bahwa Thidiazuron 1 mgL-1 + NAA 1 mgL-1 memberikan hasil yang lebih baik pada persentase eksplan hidup dan jumlah tunas pada tanaman kunyit (Curcuma domestica Val.) klon 41 pada umur 14 MST (Minggu Setelah Tanam).

scholarly journals Comparative evaluation of salivary malondialdehyde levels as a marker of lipid peroxidation in early childhood caries

2018 ◽  
Vol 12 (01) ◽  
pp. 067-070 ◽  
Author(s):  
Divya Subramanyam ◽  
Deepa Gurunathan ◽  
R. Gaayathri ◽  
V. Vishnu Priya
Keyword(s):  
Lipid Peroxidation ◽  
Comparative Evaluation ◽  
Early Childhood Caries ◽  
Thiobarbituric Acid ◽  
Significant Difference ◽  
Salivary Malondialdehyde ◽  
Carious Process ◽  
Student’S T ◽  
Student’S T Test

ABSTRACT Objective: The aim of this study was to evaluate the association between lipid peroxidation and dental caries in children with ECC by estimating the levels of MDA in saliva of children. Materials and Methods: A total of 150 children were selected; 75 children with ECC and 75 children without caries (non-ECC). Saliva samples were collected and centrifuged at 12,000 rpm for 24 min at 4°C to obtain a supernatant. MDA levels were estimated by Buege and Aust method by using thiobarbituric acid. The data obtained were analyzed by Student’s t-test to compare MDA levels between the groups. Results: MDA levels were higher in children with ECC. There was no statistically significant difference between children with ECC and without ECC (non-ECC). Conclusion: MDA levels were slightly higher in children with ECC, indicating the role of lipid peroxidation in the carious process.

scholarly journals Morphology, morphometry, and membrane integrity of epididymal spermatozoa of spotted pacas (Cuniculus paca, Linnaeus 1766)

2020 ◽  
Vol 41 (1) ◽  
pp. 181
Author(s):  
Patrícia Andrade dos Santos ◽  
Vânia Maria França Ribeiro ◽  
Augusto Luiz Faino Alves ◽  
Vanessa Lima da Silva ◽  
Breno Kalyl Freitas Nascimento ◽  
...  
Keyword(s):  
Membrane Integrity ◽  
Optical Microscope ◽  
Descriptive Statistics ◽  
Head Width ◽  
Sperm Cells ◽  
Flotation Method ◽  
Epididymal Spermatozoa ◽  
Student’S T ◽  
Student’S T Test

The objective of this study was to evaluate the morphology, morphometry, and membrane integrity of epididymal spermatozoa of spotted pacas using spermatic cells collected from the epididymal tails of five animals. The flotation method using the ACP-123® and Botusemen Special® extenders was performed, and samples were stained in Diff-Quick and eosin-nigrosine. Descriptive statistics of data were obtained and Student’s t-test was performed. The morphology of 200 Diff-Quick-stained spermatozoa showed that they had an oval head with three vesicles in the acrosomal region, a midpiece, an elongated tail; moreover, 27% of the spermatozoa exhibited cellular defects. The morphometry of 100 sperm cells (analyzed with an optical microscope and the EZ Leica LAS software for Windows) presented the following measurements (mean ± SD): total length 43.87 ± 4.91 ?m, head 7.54 ± 0.82 ?m, midpiece 5.35 ± 0.83 ?m, tail 30.72 ± 2.55 ?m, and head width 5.30 ± 0.68 ?m. Of the 2,000 cells stained with eosin-nigrosine for membrane integrity evaluation, 83.8% diluted in ACP-123® and 72.9% diluted in Botusemen® had intact membranes. The results of this study suggest that epididymal spermatozoa of pacas can be used in assisted reproduction programs; moreover, our study adds knowledge to the reproductive biology of wild animals, and encourages further research on the role of the three acrosomal vesicles present in this species.

scholarly journals Effect of cephalometric variables in paediatric snorers

2017 ◽  
Vol 3 (4) ◽  
pp. 893
Author(s):  
Himanshu Swami ◽  
Viswanathan Anand
Keyword(s):  
Soft Tissues ◽  
Age Group ◽  
Sleep Behavior ◽  
Adenotonsillar Hypertrophy ◽  
Mandibular Plane ◽  
High Prevalence ◽  
Paediatric Age ◽  
Student’S T ◽  
Anterior Posterior ◽  
Student’S T Test

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">There is a high prevalence of snoring in paediatric age group. There are various reasons for snoring in children, the most common being adenotonsillar hypertrophy. In our study we intended to establish a relationship between craniomorphological features and snoring</span><span lang="EN-IN">. </span></p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">The sudy objective was </span><span lang="EN-IN">to determine the differences in craniofacial cephalometric variables between snoring and non-snoring children. 50 snoring and 50 non-snoring children between the ages of 6 and 12 years were selected. Non-snoring subjects were matched to snoring subjects by age, sex, and ethnicity. Children with adenotonsillar hypertrophy were excluded. Snoring was assessed using a sleep behavior questionnaire administered to parents or guardians. The cephalometric radiographs of the study subjects were traced by a single investigator, 9 measurements of hard and soft tissues were recorded. The paired Student’s t test was used to analyze the cephalometric data.  </span></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">Snoring children manifest a significantly narrower anterior-posterior dimension of the pharynx at the superior and most narrow widths. Snoring children also had a greater length from the hyoid to the mandibular plane. </span></p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">Snoring children appear to present craniofacial factors that differ from those of non-snoring children.</span></p>

Sign in / Sign up

Export Citation Format

Share Document