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1.
Am J Ther ; 27(2): e194-e203, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31842112

RESUMEN

BACKGROUND: The International Myeloma Working Group has defined smoldering multiple myeloma (SMM) as the presence of 10%-60% plasma cells in the bone marrow and M-protein (IgG, IgA) ≥3 g/dL without end-organ damage (an increased calcium level, renal failure, anemia, and destructive bone lesions). AREAS OF UNCERTAINTY: Patients considered to have SMM should not have any myeloma-defining events or amyloidosis. Different risks factors classify SMM into low-, intermediate-, or high-risk categories. The rate of progression from SMM to symptomatic myeloma is ∼10% per year during the first 5 years of diagnosis. SMM requires frequent follow-up ∼every 3 months during the first 5 years as compared to monoclonal gammopathy of undermined significance, which usually requires follow-up every 6-12 months after the first year of diagnosis. DATA SOURCES: A literature search was performed from electronic bibliographic databases: MEDLINE (Ovid SP/PubMed), EMBASE, the Cochrane Library (Cochrane Database of Systematic Reviews), and Cochrane Central Register of Controlled Trials and from annual meeting abstracts from inception to May 2017. THERAPEUTIC ADVANCES: This review presents the literature and available data that support or do not support early treatment of high-risk SMM (HR-SMM) and provides evidence-based recommendations for management of SMM patients. Despite emerging data recommending early treatment of HR-SMM, we predict the SMM category may disappear in the near future and patients will be diagnosed with either multiple myeloma or monoclonal gammopathy of undermined significance. CONCLUSIONS: Success with early therapy trials for HR-SMM is largely due to patients meeting current criteria for multiple myeloma that may have been classified as SMM and, therefore, benefitted from therapy. Based on current practices and the literature, SMM should be managed with close follow-up. Based on available data, we suggest SMM to only be treated in clinical trial settings.


Asunto(s)
Antineoplásicos/uso terapéutico , Mieloma Múltiple Quiescente/tratamiento farmacológico , Manejo de la Enfermedad , Humanos , Proteínas de Mieloma/genética , Mieloma Múltiple Quiescente/genética , Análisis de Supervivencia
2.
Am J Ther ; 27(5): e500-e506, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32902937

RESUMEN

PURPOSE: Bevacizumab (BZ) combined with first line chemotherapy (CC) has shown good clinical outcomes in metastatic colorectal cancer (mCRC). Overall survival (OS) and/or progression free survival in mCRC patients receiving BZ with or without 5FU-based CC is thought to be affected by clinical and morphological factor(s). PATIENTS AND METHODS: We reviewed retrospective medical records of all consecutive mCRC patients treated with BZ with or without CC at tertiary care center between 2003 and 2009 out of which149 patients (m = 77, f = 72) were eligible. RESULTS: Our study population had a mean age at diagnosis of 63.5 years (SD = 11) with median follow-up period of 19.4 months. On initial radiological evaluation following BZ therapy, 56 patients (m = 31, f = 25) had complete or partial response categorized as "early responders." Remaining patients (m = 46, f = 47) who were either stable or showed progressive disease were categorized as "non-responders." Fifty percent among early responders and 60% among non-responders [relative risk (RR) 0.67 (95% confidence interval (CI), 0.43-1.06)] demonstrated disease progression on follow up. There was a slightly better OS among early responders compared to non-responders (median 21.5 months days versus 16.8 months, P = 0.07). Cox regression analysis suggested male sex (RR 0.65, 95% CI, 0.43-0.98), hematochezia (RR 0.63, 95% CI, 0.4-0.98), resectable primary tumor (RR 0.42, 95% CI, 0.24-0.72) and resectable metastatic mass (RR 0.32, 95% CI, 0.14-0.74) were found to be associated with longer OS. Abdominal pain (RR 1.76, 95% CI, 1.1-2.8), accompanying diabetes (RR 1.76, 95% CI, 1.09-2.85), and unexplained weight loss (RR 2.73, 95% CI, 1.73-4.29) were associated with poor OS. CONCLUSIONS: Better OS among mCRC patients with resectable primary and metastatic tumors was seen. This is the first study to demonstrate slightly better outcome in males and negative influence of diabetes on outcome in mCRC treated with BZ.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Bevacizumab/farmacología , Neoplasias del Colon/terapia , Fluorouracilo/farmacología , Dolor Abdominal/epidemiología , Dolor Abdominal/etiología , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bevacizumab/uso terapéutico , Quimioterapia Adyuvante/métodos , Neoplasias del Colon/complicaciones , Neoplasias del Colon/mortalidad , Neoplasias del Colon/patología , Diabetes Mellitus/epidemiología , Resistencia a Antineoplásicos , Femenino , Fluorouracilo/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Supervivencia sin Progresión , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Pérdida de Peso
3.
Cell Tissue Bank ; 21(2): 249-256, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32067198

RESUMEN

Radiation sterilization is an effective method of bone sterilization prior to bone graft transplantation. Gamma irradiation affects the biological and mechanical properties of bone; depending on the dose of radiation. The effect of gamma irradiation on bone mechanical properties is an unwanted phenomenon. However the mechanism of the effect of irradiation on bone mechanical properties is not properly understood. In this research paper the mechanism of the effect of gamma irradiation on bovine bone is investigated using scanning electron microscopy, energy-dispersive X-rays spectroscopy and Fourier transform infrared spectroscopy techniques. Gamma irradiation affects the mineral and fiber composition of bovine bone. The mineral content of bone especially calcium, magnesium and phosphorus decrease with increasing dose of gamma radiation. At Nano-level gamma irradiation alter amide I, amide II and amide III collagen contents. High dose gamma irradiation induces collagen cross-linking reaction in bone and degrades bone properties.


Asunto(s)
Huesos/efectos de la radiación , Rayos gamma , Animales , Huesos/ultraestructura , Calcio/análisis , Bovinos , Colágeno/química , Cadera/fisiología , Fósforo/análisis , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier
4.
Cell Tissue Bank ; 19(4): 457-472, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30426337

RESUMEN

The bone auto grafting, isografting, allografting and xenografting are used for defective bone replacement or treatment in almost all living species. The X-ray and Gamma (electromagnetic radiation) sterilization performed on the donor bone graft to prevent toxicity or migration of virus/bacterial infections from donors to reciver. Conversely, X-ray and Gamma radiation deteriorates the bone mechanical properties and bone become more susceptible to fracture. Fracture toughness as well as other mechanical properties of bone change with these radiations. In this literature review the effect of the X-rays and Gamma radiation on bone mechanical properties are discussed. All relevant literature was reviewed. After reviewing the literature only the research relating to the effect of X-rays and Gamma radiations on bone mechanical properties are included. Literature studies showed significant effect of the X-rays and Gamma radiations on the mechanical properties of the bones. In some studies the differences exists on the doses of radiations which were discussed in this study. The high energetic electromagnetic radiation (X-rays and Gamma radiations) changed/modify the collagen network of the bone, which reduced the mechanical properties of bone; however these changes depend on the radiation dose.


Asunto(s)
Huesos/fisiología , Huesos/efectos de la radiación , Rayos gamma , Animales , Fenómenos Biomecánicos/efectos de la radiación , Humanos , Rayos X
8.
Cureus ; 16(6): e63289, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39070360

RESUMEN

OBJECTIVE: The objective is to measure the change in overactive bladder (OAB) symptoms in patients undergoing flexible cystoscopy in the early postoperative period using a validated OAB-V8 tool. PATIENTS AND METHODS: It was a prospective, cross-sectional, observational study conducted by a section of Urology at the Aga Khan University Hospital, Karachi. The total duration of the study was 12 months (July 2022 to June 2023). All adult patients who underwent flexible cystoscopy under local anesthesia for diagnostic and surveillance purposes were included in the study. OAB symptoms were evaluated using the validated eight-item OAB-V8 tool just before the cystoscopy and on postoperative days 1 and 4. Patients were categorized as either OAB-negative (<8) or OAB-positive (≥8) based on their sum scores. Mean sum scores of different variables and OAB subdomains were assessed. RESULTS: Sixty-three patients were included in the final analysis with a predominantly male population. The mean pre-cystoscopy (screen) score was 7.46 + 5.58, which increased to 9.89 + 6.82 on day 1 (p<0.01) before decreasing back to 7.68 + 5.7 on day 4 (p=0.08). Twenty-one patients (33.3%) were labeled OAB positive on day 0. Following cystoscopy, this number increased to 32 patients (50.8%) as 11 patients (26.2 %) developed de-novo OAB symptoms. The sub-group analysis showed an insignificant impact of age (p=0.5), gender (p=0.51), indication (p=0.22), and use of alpha-blocker (p= 0.30) on change in OAB score. CONCLUSION:  OAB symptoms are frequently encountered in patients undergoing awake (flexible) cystoscopy. This procedure can also trigger de novo OAB symptoms, albeit transiently, which typically resolve over time. This information could help in patient counseling, management, and the need for intervention in the future.

9.
Inquiry ; 61: 469580221148431, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39155624

RESUMEN

Coronavirus disease 2019 (COVID-19), a disease caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged initially as an isolated illness in December 2019 and later progressed to a global pandemic. Hard-hit areas were lockdown, massively disrupting medical education activities. Tele-education, previously used as a means of long-distance education emerged as a solution in the field of medical education. Tele-rotations for medical students, journal clubs and lectures via Microsoft teams, medical conferences via zoom, residency, and fellowship interviews online, all emerged during this pandemic. Some medical students and trainees found it enjoyable, cost-effective, time saving, feasible, unbiased, and preferred mode of education. Challenges related to supervision, availability, affordability, diminished communication, disturbance of streaming, or distractions due to environment. Tele-education has had a boom in the era of COVID-19. Research is needed further on effective mentoring and supervision of trainees via tele educational teaching models.


Asunto(s)
COVID-19 , Educación a Distancia , Educación Médica , SARS-CoV-2 , COVID-19/epidemiología , Humanos , Educación Médica/organización & administración , Pandemias , Telemedicina/organización & administración
10.
Adv Hematol ; 2023: 9949961, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38094101

RESUMEN

Background: Graft-versus-host disease (GVHD) is a potentially fatal complication of allogeneic hematopoietic stem cell transplant. The mainstay of treatment is corticosteroids, which are ineffective in 30-50% of cases. Steroid-refractory GVHD (SR-GVHD) confers a poor prognosis, with high mortality rates despite appropriate therapy. While there is no reliable treatment for SR-GVHD, a variety of novel therapeutic options are slowly emerging and have yet to be examined simultaneously. Objectives: This review evaluates the potential of novel therapeutic options, as well as their efficacy and safety, for the treatment of SR-GVHD. Study Design. The literature search was conducted in PubMed, Cochrane, and Embase, employing MeSH terms and keywords. The studies had to be prospective phases 1, 2, or 3. We excluded retrospective and nonoriginal studies. Results: While the only approved drug for acute GVHD is ruxolitinib with an impressive overall response rate of 73.2% and a complete response of 56.3%, several monoclonal antibodies and other agents are currently under investigation, offering promising results. These include anti-CD2, anti-CD147, IL-2 antagonist, a mixture of anti-CD3 and anti-CD7 antibodies, anti-CD25, monoclonal antibody to a4b7 on T-cells, anti-CD26, pentostatin, sirolimus, denileukin diftitox, infliximab, itacitinib, and alpha-1 antitripsin. However, the toxicities associated with these novel drugs need further investigation. For chronic GVHD, approved options include ruxolitinib with an ORR of up to 62%, ibrutinib with an ORR of up to 77%, and belumosudil with an ORR of up to 77%. Meanwhile, emerging treatments include tyrosine kinase inhibitors such as nilotinib, rituximab, and low-dose IL-2, as well as axatilimab and pomalidomide. Conclusion: While their efficacy needs to be better evaluated through large-scale, multicenter, randomized clinical trials, these novel agents show potential and could provide a better alternative for SR-GVHD treatment in the future.

11.
Biomed Mater Eng ; 33(2): 91-99, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34366315

RESUMEN

BACKGROUND: Understanding the fracture mechanics of bone is very important in both the medical and bioengineering field. Bone is a hierarchical natural composite material of nanoscale collagen fibers and inorganic material. OBJECTIVE: This study investigates and presents the fracture toughness of bovine cortical bone by using elastic plastic fracture mechanics. METHODS: The J-integral was used as a parameter to calculate the energies utilized in both elastic deformation (Jel) and plastic deformation (Jpl) of the hipbone fracture. Twenty four different types of specimens, i.e. longitudinal compact tension (CT) specimens, transverse CT specimens, and also rectangular unnotched specimens for tension in longitudinal and transverse orientation, were cut from the bovine hip bone of the middle diaphysis. All CT specimens were prepared according to the American Society for Testing and Materials (ASTM) E1820 standard and were tested at room temperature. RESULTS: The results showed that the average total J-integral in transverse CT fracture specimens is 26% greater than that of longitudinal CT fracture specimens. For longitudinal-fractured and transverse-fractured cortical specimens, the energy used in the elastic deformation was found to be 2.8-3 times less than the energy used in the plastic deformation. CONCLUSION: The findings indicate that the overall fracture toughness measured using the J-integral is significantly higher than the toughness calculated by the stress intensity factor. Therefore, J-integral should be employ to compute the fracture toughness of cortical bone.


Asunto(s)
Fracturas de Cadera , Huesos Pélvicos , Animales , Bovinos , Hueso Cortical/diagnóstico por imagen , Plásticos , Estrés Mecánico
12.
Expert Rev Hematol ; 15(11): 999-1008, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36314081

RESUMEN

INTRODUCTION: Copper is increasingly being recognized as a vital mineral required by both animals and humans. It plays a vital role in many metabolic processes such as cellular respiration, iron oxidation, and hemoglobin synthesis. Copper deficiency, which can be hereditary or acquired, can lead to a wide spectrum of disease processes such as ringed sideroblastic anemia, myelodysplasia, and pancytopenia. Timely identification and management of copper deficiency is necessary to prevent irreversible complications. AREAS COVERED: Our study focuses on prevalence, etiology, pathophysiology, complications, and treatment of copper deficiency. EXPERT OPINION: Copper deficiency is frequently underrecognized as the cause of anemia, neutropenia, and bone marrow dysplasia. As it is potentially treatable, it should always be kept in the differentials when patients present with neurological and hematological abnormalities.


Asunto(s)
Anemia , Enfermedades Hematológicas , Síndromes Mielodisplásicos , Neutropenia , Pancitopenia , Animales , Humanos , Pancitopenia/diagnóstico , Pancitopenia/etiología , Cobre/metabolismo , Anemia/etiología , Enfermedades Hematológicas/complicaciones , Neutropenia/etiología , Neutropenia/complicaciones , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/diagnóstico
13.
Materials (Basel) ; 15(6)2022 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-35329516

RESUMEN

In this study, the ballistic impact behavior of auxetic sandwich composite human body armor was analyzed using finite element analysis. The auxetic core of the armor was composed of discrete re-entrant unit cells. The sandwich armor structure consisted of a front panel of aluminum alloy (Al 7075-T6), UHMWPE (sandwich core), and a back facet of silicon carbide (SiC) bonded together with epoxy resin. Numerical simulations were run on Explicit Dynamics/Autodyne 3-D code. Various projectile velocities with the same boundary conditions were used to predict the auxetic armor response. These results were compared with those of conventional monolithic body armor. The results showed improved indentation resistance with the auxetic armor. Deformation in auxetic armor was observed greater for each of the cases when compared to the monolithic armor, due to higher energy absorption. The elastic energy dissipation results in the lower indentation in an auxetic armor. The armor can be used safely up to 400 m/s; being used at higher velocities significantly reduced the threat level. Conversely, the conventional monolithic modal does not allow the projectile to pass through at a velocity below 300 m/s; however, the back face becomes severely damaged at 200 m/s. At a velocity of 400 m/s, the front facet of auxetic armor was destroyed; however, the back facet was completely safe, while the monolithic panel did not withstand this velocity and was completely damaged. The results are encouraging in terms of resistance offered by the newly adopted auxetic armor compared to conventional monolithic armor.

14.
Cureus ; 13(5): e15282, 2021 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-34194883

RESUMEN

Background Peripheral neuropathy (PN), especially peripheral sensory neuropathy (PSN), is significant toxicity of taxanes, the most used class of microtubule inhibitors for human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients. Ado-trastuzumab emtansine (T-DM1) is a HER2-targeted antibody-drug conjugate, consisting of trastuzumab and a microtubule inhibitor DM1, which has been approved for HER2-positive breast cancer. T-DM1 has also been found to cause significant PN, including PSN. Methods We conducted a systematic review and meta-analysis of phase 3 randomized controlled trials using T-DM1 in the experimental arm and a taxane-based regimen in the control arm to determine the relative risk of PN and PSN associated with T-DM1 as compared to taxanes. A total of 1,857 patients were included in the analysis. The Cochran-Mantel-Haenszel method and the random-effects model were used to calculate the pooled risk ratio (RR) with a 95% confidence interval (CI) for all-grade and grade ≥3 PN and PSN.  Results The relative risks of all-grade PN and all-grade PSN were lower with T-DM1 compared to taxanes. The pooled RR of all-grade PN was 0.59, 95% CI: 0.39-0.89, P = 0.01, and the pooled RR of all-grade PSN was 0.58, 95% CI: 0.46-0.74, P < 0.0001. Conclusions Our meta-analysis demonstrated that T-DM1 is associated with a relatively lower risk of all-grade PN and PSN than the taxane-based regimens for HER2-positive cancers. It could be an area of consideration in selecting therapy for HER2-positive breast cancer patients at high risk of developing or having pre-existing PN and PSN.

15.
Cureus ; 13(1): e12751, 2021 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-33643726

RESUMEN

Coronavirus disease 2019 (COVID-19) infection has been associated with various complications such as acute respiratory distress syndrome, acute kidney failure, myocardial infection, and thromboembolism. Cold agglutinin syndrome (CAS) has been associated with other viral infections such as Epstein-Barr virus (EBV), but there have been only a few reports of cold agglutination associated with COVID-19. In this report, we describe a case of transient cold agglutinin elevation in a COVID-19-infected patient. A 61-year-old man with hypertension, diabetes mellitus, and end-stage renal disease (ESRD) presented with shortness of breath, cough, and lethargy for five days. A clinical diagnosis of COVID-19 infection was made. The COVID-19 RNA qualitative real-time polymerase-chain-reaction (PCR) assay tested positive. During the hospital stay, he had progressive dyspnea requiring intubation and mechanical ventilation. During the third week of hospital stay, an acute drop in the hemoglobin (Hb) level to 4.5 g/dl (baseline Hb: 9 g/dl) was observed. The workup for acute anemia revealed a positive result for cold agglutinins, direct antibody test (C3d), and agglutination of the red blood cells were apparent on the peripheral blood smear. Further, cold agglutinin titers peaked during the third week of the onset of illness and significantly declined during the fifth week. These observational findings indicate that cold agglutinin titers might correlate with the disease activity.

16.
Immunotherapy ; 13(9): 767-782, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33910383

RESUMEN

Pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the USA and the seventh leading cause of cancer-related death worldwide. Most of the patients' presentation is in advanced stages and remains resistant to currently available standard therapies. An in-depth understanding of PDAC's pathogenesis has shown that immunotherapy could bring about a revolution in the treatment response. Immunotherapy in PDAC appears promising in preclinical studies but failed to show benefits in clinical studies. These novel agents' therapeutic failure can be attributed to multiple variables including the tumor microenvironment, early metastasis, tumor heterogeneity and resistance to therapy. There is a need to develop biomarkers for the patient's stratification and provide individualized treatment to improve treatment outcomes.


Lay abstract Pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the USA and the seventh leading cause of cancer-related death worldwide. PDAC is a lethal cancer; most patients present at advanced stages with minimal clinical response to the current standard therapies. Immunotherapy treatment in PDAC showed promising results in the preclinical studies. However, the majority of clinical studies on immunotherapy in PDAC did not show clinical benefits. There is a need for research to explore the benefits of immunotherapy in PDAC patients. The development of new treatment strategies and a patient-tailored approach might improve future outcomes.


Asunto(s)
Adenocarcinoma/terapia , Inmunoterapia/métodos , Neoplasias Pancreáticas/terapia , Humanos , Neoplasias Pancreáticas
17.
Cureus ; 13(5): e15269, 2021 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-34194873

RESUMEN

Background and objective The efficacy of vancomycin vs. teicoplanin for the successful treatment of febrile neutropenia (FN) has been a subject of debate in the medical community. In light of this, we performed a systematic review and meta-analysis to compare these two medications in the treatment of patients with FN in terms of treatment success and adverse events. Data source and study design We conducted a search of major electronic databases [MEDLINE (PubMed, Ovid), Google Scholar, clinicaltrial.org], which returned 10 studies with 1,630 patients (vancomycin: 788; teicoplanin: 842) for analysis. An unadjusted odds ratio (OR) with a 95% confidence interval (CI) was calculated for all studies, as well as separate sub-analyses of randomized controlled trials (RCTs) and retrospective studies. Results The average age of patients ranged from 37 to 57 years in the vancomycin group and 31 to 57 years in the teicoplanin group (n=9 studies). Over half of the patients in both groups were male (vancomycin: 55.6%; teicoplanin: 57.7%; n=9 studies). Both overall evaluation and sub-analyses revealed that both treatments were comparable in terms of treatment success, nephrotoxicity, and red man syndrome. The vancomycin group was more likely to develop skin rashes (OR: 2.49; 95% CI: 1.28-4.83). The heterogeneity for all analyses ranged from 0-47.4%. Conclusion Our analysis showed that vancomycin and teicoplanin showed comparable results in terms of successful treatment of FN. Adverse effects such as nephrotoxicity and red man syndrome were also comparable between the two treatment groups.

19.
Ticks Tick Borne Dis ; 9(3): 735-737, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29500125

RESUMEN

We report a rare case of a 53-year-old man with no significant past medical history who reported multiple tick bites within a 2-month period. The patient reported not "feeling well" for the 2 ½ weeks. He complained of generalized body aches, pains, and chills. He did not report nausea, vomiting, or yellowish discoloration of the eyes or skin. He presented to the emergency room with syncope preceded by severe abdominal pain. Upon presentation, he was pale and hypotensive. He had not experienced any trauma. Computed tomography revealed a splenic rupture, hemoperitoneum, and active extravasation of contrast material. The estimated amount of hemoperitoneum was 1.5 liters of blood. Subsequently, an infectious disease work-up revealed a positive Anaplasma phagocytophilum polymerase reaction in blood. The patient was aggressively resuscitated, and a splenectomy was performed followed by doxycycline therapy. He successfully recovered.


Asunto(s)
Anaplasma phagocytophilum/aislamiento & purificación , Anaplasmosis/diagnóstico , Rotura del Bazo/etiología , Enfermedades por Picaduras de Garrapatas/diagnóstico , Abdomen/diagnóstico por imagen , Anaplasma phagocytophilum/genética , Anaplasmosis/complicaciones , Anaplasmosis/tratamiento farmacológico , Anaplasmosis/epidemiología , Antibacterianos/uso terapéutico , ADN Bacteriano/sangre , ADN Bacteriano/genética , Doxiciclina/uso terapéutico , Hemoperitoneo/diagnóstico por imagen , Hemoperitoneo/microbiología , Humanos , Masculino , Persona de Mediana Edad , Rotura Espontánea , Bazo/diagnóstico por imagen , Bazo/microbiología , Bazo/patología , Esplenectomía , Rotura del Bazo/diagnóstico por imagen , Síncope , Mordeduras de Garrapatas/microbiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/microbiología , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Estados Unidos/epidemiología
20.
Biomed Mater Eng ; 29(5): 601-610, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30400074

RESUMEN

The crack propagation behavior near the initial crack were studied under the compact tension (CT) fracture toughness experiments test on bovine hip bone joint specimens. The bone specimens were prepared according to ASTM E-399 for plain fracture toughness tests. The specimens were cut from the hip joint both in the longitudinal and transverse direction to the collagen fiber orientation in the bone. The precrack or initial crack "a" were produced parallel and vertical to the lontudinal axis of bone in the longitudinal and transverse specimens respectively. The specimens were tested in the universal testing machine for finding fracture toughness and crack propagation behavior due to different orientation of bone fibers. A camera attached to the machine recorded the crack propagation process. The results show a different crack propagation behavior in longitudinal specimens and transverse specimens. The toughness of the bone consistently changes with age both in longitudinal and transverse direction. Our experimental data matched with the previous published research.


Asunto(s)
Hueso Cortical/lesiones , Fracturas de Cadera/patología , Huesos Pélvicos/lesiones , Factores de Edad , Animales , Fenómenos Biomecánicos , Bovinos , Hueso Cortical/patología , Masculino , Huesos Pélvicos/patología , Estrés Mecánico , Soporte de Peso
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