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1.
JMIR Form Res ; 7: e39838, 2023 Nov 10.
Article in English | MEDLINE | ID: mdl-37948110

ABSTRACT

BACKGROUND: Insufficient levels of treatment adherence can have adverse effects on the outcomes of physical rehabilitation. To address this issue, alternative approaches to traditional therapies, such as serious games, have been designed to enhance adherence. Nevertheless, there remain gaps in the development of serious games concerning the effective implementation of motivation, engagement, and the enhancement of treatment adherence. OBJECTIVE: This study aims to design a conceptual framework for the development of serious games that incorporate essential adherence factors to enhance patient compliance with physical rehabilitation programs. METHODS: We formulated a conceptual framework using iterative techniques inspired by a conceptual framework analysis. Initially, we conducted a comprehensive literature review, concentrating on the critical adherence factors in physical rehabilitation. Subsequently, we identified, categorized, integrated, and synthesized the concepts derived from the literature review to construct the conceptual framework. RESULTS: The framework resembles a road map, comprising 3 distinct phases. In the initial phase, the patient's characteristics are identified through an initial exploration. The second phase involves the development of a serious game, with a focus on enhancing treatment adherence by integrating the key adherence factors identified. The third phase revolves around the evaluation of the serious game. These phases are underpinned by 2 overarching themes, namely, a user-centered design and the GameFlow model. CONCLUSIONS: The conceptual framework offers a detailed, step-by-step guide for creating serious games that incorporate essential adherence factors, thereby contributing to improved adherence in the physical rehabilitation process. To establish its validity, further evaluations of this framework across various physical rehabilitation programs and user groups are necessary.

2.
J Perioper Pract ; 33(9): 276-281, 2023 09.
Article in English | MEDLINE | ID: mdl-35904049

ABSTRACT

The aim of this study was to determine the rate of preoperative transthoracic echocardiography in hip fracture patients and to evaluate its effects on time to surgery and length of stay. We conducted a retrospective review of all patients with hip fractures treated at a tertiary referral hospital. Data examined included age, sex, comorbidities, time to surgery, length of stay, fracture type and transthoracic echocardiography findings. Forty-eight patients with hip fractures underwent surgery (men 41.7%; mean age 77.2 (49-95)). Nine patients (18.7%) had a preoperative transthoracic echocardiography. Preoperative transthoracic echocardiography was associated with a significantly longer time to surgery an abbreviation for days e.g dys should be added after the values to indicate what time frame is being measured (14.7 versus 6.8, p = 0.0051) and length of stay (23.6 versus 10.4, p = 0.0002). This study demonstrates a high rate of preoperative transthoracic echocardiography in hip fracture patients. The role of transthoracic echocardiography should be reassessed in view of its association with significant surgical delays.


Subject(s)
Hip Fractures , Male , Humans , Aged , Hip Fractures/diagnostic imaging , Hip Fractures/surgery , Retrospective Studies , Comorbidity , Time Factors , Echocardiography , Length of Stay
3.
Cureus ; 14(10): e30503, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36415368

ABSTRACT

The rapid spread of the deadly coronavirus disease 2019 (COVID-19) pandemic has fundamentally affected healthcare delivery globally. As governments struggled to preserve life, several approaches to healthcare delivery have emerged. Central to limiting viral transmission is the separation of patients based on their COVID-19 status. Studies have shown that a geographically separate dual-site service is preferable, contingent upon the local infrastructure and circumstances. Despite the restrictions on free movement, most studies indicate that low-energy hip fractures in elderly patients have remained relatively constant throughout the pandemic. Arguably these patients represent the most vulnerable subgroup in society and are susceptible to developing severe COVID-19 respiratory disease. In keeping with global recommendations, the government of Trinidad and Tobago devised a parallel healthcare system to limit the spread of disease. All regional health authorities under the Ministry of Health were at liberty to implement the system in a manner best suited for their particular infrastructure leading to highly variable practices among institutions. This report describes the clinical course of two hip fracture patients treated within the parallel healthcare system at different regional health authorities. Analysis of these cases provides an understanding of the potential risks to patients entering the parallel healthcare system and an insight into preventative measures to improve clinical outcomes.

4.
J Perioper Pract ; 32(11): 320-325, 2022 11.
Article in English | MEDLINE | ID: mdl-35574718

ABSTRACT

An earthquake in 2018 resulted in irreparable damage to the Port of Spain General Hospital, Trinidad and Tobago, and severely affected orthopaedic services. This study investigates the rate and reasons for cancellation on the day of surgery of orthopaedic cases during the post-earthquake period. We prospectively collected data on all cases scheduled to undergo surgery during the study period. Information was gathered on patient demographics, the number and reasons for cancellation. Data were analysed using Analyse-it for Microsoft Excel 5.40 (Analyse-it Software Ltd). Our results show that 43 patients were cancelled, resulting in a 44.3% cancellation rate. Patients who had their surgery cancelled were older, with a higher American Society of Anesthesiologists class compared with patients whose surgery was not cancelled. Hospital-related factors were found to be responsible for the majority of cancellations. Placed in context, our findings suggest that limited operating time due to the earthquake-induced hospital damage was the principal reason for the high rate of surgery cancellations.


Subject(s)
Earthquakes , Orthopedics , Humans , Appointments and Schedules , Operating Rooms , Trinidad and Tobago , Hospitals, General , Elective Surgical Procedures
5.
JMIR Serious Games ; 9(4): e25831, 2021 Nov 11.
Article in English | MEDLINE | ID: mdl-34762052

ABSTRACT

BACKGROUND: Serious games are a support in the rehabilitation process for treating people with physical disabilities. However, many of these serious games are not adapted to the patient's needs because they are not developed with a software engineering framework with a set of activities, actions, and tasks that must be executed when creating a software product. Better serious games for rehabilitation will be developed if the patient and therapist requirements are identified, the development is planned, and system improvements and feedback are involved. The goal is that the serious game must offer a more attractive environment, while maintaining patient interest in the rehabilitation process. OBJECTIVE: This paper submits the results of a systematic review of serious games in physical rehabilitation identifying the benefits of using a software engineering framework. METHODS: A systematic research was conducted using PubMed, PEDro (Physiotherapy Evidence Database), IEEE Xplore, ScienceDirect, ACM Digital Library, Mary Ann Liebert, Taylor & Francis Online, Wiley Online Library, and Springer databases. The initial search resulted in 701 papers. After assessing the results according to the inclusion criteria, 83 papers were selected for this study. RESULTS: From the 83 papers reviewed, 8 used a software engineering framework for its development. Most of them focused their efforts on 1 or more aspects, such as data acquisition and processing, game levels, motivation, therapist supervision. CONCLUSIONS: This systematic review proves that most of the serious games do not use a software engineering framework for their development. As a result, development systems overlook several aspects and do not have a standardized process, eventually omitting important implementation aspects, which impact the patient's recovery time.

6.
Cureus ; 13(6): e15761, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34290937

ABSTRACT

Revision total hip arthroplasty (THA) is a major reconstructive procedure traditionally associated with significant blood loss. Jehovah's Witnesses (JW) do not accept blood or blood product transfusions because of their religious beliefs. When confronted with a JW patient requiring a complex arthroplasty procedure, surgeons face moral and ethical questions and may be reluctant to perform surgery. A successful outcome depends on several factors including surgical and anesthetic expertise, a range of revision implants, and a multimodal blood management protocol. While these resources are readily available in a developed country, in many of the developing Caribbean islands, the healthcare system is underfunded and under-resourced. Here, we describe our experience performing a revision THA on a JW patient in the Caribbean. Through this case report, we aim to illustrate our approach to blood management by exploring the fundamental elements that were employed in a low-resource setting. We believe that the extrapolation of these crucial principles to the broader category of primary arthroplasty in the general population can be used to reduce the rate of blood transfusion, increase access to surgery, and improve outcomes.

7.
JMIR Serious Games ; 9(2): e25854, 2021 Jun 24.
Article in English | MEDLINE | ID: mdl-34185003

ABSTRACT

BACKGROUND: Serious games have been used as supportive therapy for traditional rehabilitation. However, most are designed without a systematic process to guide their development from the phases of requirement identification, planning, design, construction, and evaluation, which reflect the lack of adaptation of rehabilitation requirements and thus the patient's needs. OBJECTIVE: The aim of this study was to propose a conceptual framework with standardized elements for the development of information systems by using a flexible and an adaptable process centered on the patient's needs and focused on the creation of serious games for physical rehabilitation. METHODS: The conceptual framework is based on 3 fundamental concepts: (1) user-centered design, which is an iterative design process focused on users and their needs at each phase of the process, (2) generic structural activities of software engineering, which guides the independent development process regardless of the complexity or size of the problem, and (3) gamification elements, which allow the transformation of obstacles into positive and fun reinforcements, thereby encouraging patients in their rehabilitation process. RESULTS: We propose a conceptual framework to guide the development of serious games through a systematic process by using an iterative and incremental process applying the phases of context identification, user requirements, planning, design, construction of the interaction devices and video game, and evaluation. CONCLUSIONS: This proposed framework will provide developers of serious games a systematic process with standardized elements for the development of flexible and adaptable software with a high level of patient commitment, which will effectively contribute to their rehabilitation process.

8.
Biosensors (Basel) ; 11(2)2021 Feb 23.
Article in English | MEDLINE | ID: mdl-33672317

ABSTRACT

Vital signs not only reflect essential functions of the human body but also symptoms of a more serious problem within the anatomy; they are well used for physical monitoring, caloric expenditure, and performance before a possible symptom of a massive failure-a great variety of possibilities that together form a first line of basic diagnosis and follow-up on the health and general condition of a person. This review includes a brief theory about fiber optic sensors' operation and summarizes many research works carried out with them in which their operation and effectiveness are promoted to register some vital sign(s) as a possibility for their use in the medical, health care, and life support fields. The review presents methods and techniques to improve sensitivity in monitoring vital signs, such as the use of doping agents or coatings for optical fiber (OF) that provide stability and resistance to the external factors from which they must be protected in in vivo situations. It has been observed that most of these sensors work with single-mode optical fibers (SMF) in a spectral range of 1550 nm, while only some work in the visible spectrum (Vis); the vast majority, operate through fiber Bragg gratings (FBG), long-period fiber gratings (LPFG), and interferometers. These sensors have brought great advances to the measurement of vital signs, especially with regard to respiratory rate; however, many express the possibility of monitoring other vital signs through mathematical calculations, algorithms, or auxiliary devices. Their advantages due to miniaturization, immunity to electromagnetic interference, and the absence of a power source makes them truly desirable for everyday use at all times.


Subject(s)
Fiber Optic Technology , Monitoring, Physiologic/methods , Algorithms , Heart Rate , Humans , Interferometry , Optical Fibers , Vital Signs
9.
Rev. cientif. cienc. med ; 19(2): 20-26, 2016. ilus
Article in Spanish | LILACS | ID: biblio-959716

ABSTRACT

La calidad diagnóstica es el resultado de integrar el conocimiento médico y reconocimiento de los errores clínicos, se alcanza únicamente con la identificación de las causas de muerte; es la correlación clínico patológica la herramienta principal para dicha acción. El objetivo general de la investigación fue determinar la discrepancia clínico-patológica y su relación con otras variables en las autopsias realizadas en la institución. Se revisaron 159 protocolos de autopsia del período comprendido entre enero 2012 y junio 2016, elaborados por el Servicio de Patología del Hospital Escuela Universitario de Tegucigalpa, Honduras. Se excluyeron 36 por no cumplir los criterios de inclusión. Se utilizaron la CIE-10 y la clasificación de Goldman et al. para clasificar las patologías y establecer las discrepancias diagnósticas, respectivamente. El sexo predominante fue el femenino (2,96:1), la edad media fue de 38 años; prevalecieron los diagnósticos de embarazo/parto/puerperio y enfermedades infecciosas y parasitarias. Concluimos que en 46% de los casos existe discrepancia diagnóstica y la glomerulonefritis fue la principal causa de error, seguida de bronconeumonía. Se recomienda estandarizar el protocolo de autopsias y promover sesiones clínico-patológicas periódicas e integrales.


Diagnostic quality is the result of the integration of medical knowledge and recognition of clinical error, achieved only by identifying the cause of death; clinical pathological correlation is the primary tool for this action. The overall objective of this research was to determine clinical pathological discrepancy and its relationship with other variables within the autopsies performed at the institution. 159 autopsy protocols, elaborated by the Department of Pathology of Hospital Escuela Universitario in Tegucigalpa, Honduras, from January 2012 to June 2016, were reviewed. 36 were excluded for not meeting the inclusion criteria. ICD-10 and Goldman et al. modified by Battle criteria were used to classify diseases and establish diagnostic discrepancies, respectively. The majority of patients were female (2.96:1), the mean age was 38 years old; diagnoses of pregnancy/birth/puerperium and infectious and parasitic diseases prevailed. We conclude that diagnostic discrepancies exist in 46% of all cases and glomerulonephritis was the leading cause of error, followed by bronchopneumonia. It is recommended that autopsy protocols be standardized, and integrative clinical pathological sessions are promoted and integral.


Subject(s)
Autopsy/statistics & numerical data , Clinical Diagnosis , Lung Diseases/mortality
10.
Molecules ; 20(10): 19372-92, 2015 Oct 23.
Article in English | MEDLINE | ID: mdl-26512637

ABSTRACT

ß-Glucosidase (EC 3.2.1.21) is a prominent member of the GH1 family of glycoside hydrolases. The properties of this ß-glucosidase appear to include resistance to temperature, urea, and iodoacetamide, and it is activated by 2-ME, similar to other members. ß-Glucosidase from chayote (Sechium edule) was purified by ionic-interchange chromatography and molecular exclusion chromatography. Peptides detected by LC-ESI-MS/MS were compared with other ß-glucosidases using the BLAST program. This enzyme is a 116 kDa protein composed of two sub-units of 58 kDa and shows homology with Cucumis sativus ß-glucosidase (NCBI reference sequence XP_004154617.1), in which seven peptides were found with relative masses ranging from 874.3643 to 1587.8297. The stability of ß-glucosidase depends on an initial concentration of 0.2 mg/mL of protein at pH 5.0 which decreases by 33% in a period of 30 h, and then stabilizes and is active for the next 5 days (pH 4.0 gives similar results). One hundred µg/mL ß-D-glucose inhibited ß-glucosidase activity by more than 50%. The enzyme had a Km of 4.88 mM with p-NPG and a Kcat of 10,000 min(-1). The optimal conditions for the enzyme require a pH of 4.0 and a temperature of 50 °C.


Subject(s)
Cucurbitaceae/enzymology , beta-Glucosidase/isolation & purification , Amino Acid Sequence , Chemical Precipitation , Chromatography, Ion Exchange , Enzyme Stability , Glucose/chemistry , Hydrogen-Ion Concentration , Kinetics , Molecular Sequence Data , Plant Proteins , Sequence Homology, Amino Acid , Substrate Specificity , beta-Glucosidase/chemistry
11.
Med Sci Monit ; 20: 843-52, 2014 May 23.
Article in English | MEDLINE | ID: mdl-24852266

ABSTRACT

BACKGROUND: To determine if edentulism, controlling for other known factors, is associated with subjective self-report health status (SRH) in Mexican adults. MATERIAL AND METHODS: We examined the SRH of 13 966 individuals 35 years and older, using data from the National Survey of Performance Assessment, a cross-sectional study that is part of the technical collaboration between the Ministry of Health of Mexico and the World Health Organization, which used the survey instrument and sampling strategies developed by WHO for the World Health Survey. Sociodemographic, socioeconomic, medical, and behavioral variables were collected using questionnaires. Self-reported health was our dependent variable. Data on edentulism were available from 20 of the 32 Mexican states. A polynomial logistic regression model adjusted for complex sampling was generated. RESULTS: In the SRH, 58.2% reported their health status as very good/good, 33.8% said they had a moderate health status, and 8.0% reported that their health was bad/very bad. The association between edentulism and SRH was modified by age and was significant only for bad/very bad SRH. Higher odds of reporting moderate health or poor/very poor health were found in women, people with lower socio-economic status and with physical disabilities, those who were not physically active, or those who were underweight or obese, those who had any chronic disease, and those who used alcohol. CONCLUSIONS: The association of edentulism with a self-report of a poor health status (poor/very poor) was higher in young people than in adults. The results suggest socioeconomic inequalities in SRH. Inequality was further confirmed among people who had a general health condition or a disability. Dentists and health care professionals need to recognize the effect of edentulism on quality of life among elders people.


Subject(s)
Health Status , Mouth, Edentulous/epidemiology , Self Report , Adult , Demography , Female , Humans , Logistic Models , Male , Mexico/epidemiology , Multivariate Analysis , Socioeconomic Factors
12.
Int J Environ Res Public Health ; 11(3): 3169-84, 2014 Mar 17.
Article in English | MEDLINE | ID: mdl-24642844

ABSTRACT

Oral diseases are a major burden on individuals and health systems. The aim of this study was to determine whether consumption of tobacco and alcohol were associated with the prevalence of oral/dental problems in Mexican adults. Using data from the National Performance Evaluation Survey 2003, a cross-sectional study part of the World Health Survey, dental information from a representative sample of Mexico (n = 22,229, N = 51,155,740) was used to document self-reported oral/dental problems in the 12 months prior to the survey. Questionnaires were used to collect information related to sociodemographic, socioeconomic, and other risk factors. Three models were generated for each age group (18-30, 31-45 and 46-98 years). The prevalence of oral/dental conditions was 25.7%. Adjusting for sex, schooling, socioeconomic position, diabetes, and self-reported health, those who used tobacco (sometimes or daily) (OR = 1.15, p = 0.070; OR = 1.24, p < 0.01; and OR = 1.16, p < 0.05, for each age group respectively) or alcohol (moderate or high) (OR = 1.26, p < 0.001; OR = 1.18, p < 0.01 and OR = 1.30, p < 0.001, for each age group respectively) had a higher risk of reporting oral/dental problems. Because tobacco and alcohol use were associated with self-reported oral/dental problems in one out of four adults, it appears advisable to ascertain how direct is such link; more direct effects would lend greater weight to adopting measures to reduce consumption of tobacco and alcohol for the specific purpose of improving oral health.


Subject(s)
Alcohol Drinking/adverse effects , Stomatognathic Diseases/epidemiology , Tobacco Use/adverse effects , Adolescent , Adult , Cross-Sectional Studies , Female , Humans , Logistic Models , Male , Mexico/epidemiology , Middle Aged , Prevalence , Stomatognathic Diseases/etiology , Young Adult
13.
J Periodontol ; 85(3): 406-16, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23895250

ABSTRACT

BACKGROUND: The possible association between oral infection and chronic inflammation and cardiovascular disease risk has been studied intensively. The present study is designed to determine the strength of association between edentulism and angina pectoris in Mexican adults aged 35 years and older. METHODS: Using the tools and sampling strategies of the World Health Survey of the World Health Organization, cross-sectional data were collected in Mexico in the National Performance Assessment Survey (probabilistic, multistage, and cluster sampling). Dental information was available for 20 of the 32 states of Mexico. Angina and edentulism are self-reported in this study. Statistical analysis was performed using binary logistic regression adjusting for complex samples. RESULTS: A total of 13,966 participants, representing a population of 29,853,607 individuals, were included. Of the complete study population, 3,052,263 (10.2%) were completely toothless, and 673,810 (2.3%) were diagnosed with angina pectoris. After adjusting for smoking, alcohol consumption, diabetes, body mass index, and sex, the effect of edentulism on angina was modified by age (interaction), being more marked in the younger age group (odds ratio [OR] = exp(2.5597) =12.93) than in the older individuals surveyed (OR = exp(2.5597 + (-0.0334)) =12.51). Additionally, low physical activity (OR = 1.51; 95% confidence interval [CI] = 1.03 to 2.22) and higher socioeconomic status (OR = 1.37; 95% CI = 1.00 to 1.90) were more likely to be associated with angina pectoris. CONCLUSIONS: Overall, the results of this study, conducted in a representative sample of Mexican adults, suggest that an association exists between edentulism and angina pectoris. Additional studies are necessary to elucidate the underlying mechanism for this association.


Subject(s)
Angina Pectoris/epidemiology , Mouth, Edentulous/epidemiology , Adult , Age Factors , Aged , Aged, 80 and over , Alcohol Drinking/epidemiology , Body Mass Index , Cross-Sectional Studies , Diabetes Mellitus/epidemiology , Female , Humans , Male , Mexico/epidemiology , Middle Aged , Motor Activity , Population Surveillance , Rural Health/statistics & numerical data , Sex Factors , Smoking/epidemiology , Social Class , Urban Health/statistics & numerical data
14.
Rev Invest Clin ; 65(2): 141-9, 2013.
Article in Spanish | MEDLINE | ID: mdl-23844532

ABSTRACT

BACKGROUND: Tooth extractions are one of the most common procedures in oral surgery. The objective of this study was to identify the reasons for tooth extraction in adult patients seeking care at teaching dental clinics. MATERIAL AND METHODS: A cross-sectional study was carried out in 331 subjects between 18 and 85 (45.37 +/- 13.85) years of age seeking dental care in dental clinics of the Universidad Autónoma del Estado de Hidalgo, from January 2009 to December, 2009. Data pertaining to age, sex, tooth number and the reason for extraction according to Kay & Blinkhorn were analyzed with non-parametric tests. RESULTS: 779 extractions were undertaken. The main reason for extraction was dental caries (43.1%), periodontal disease (PD) (27.9%), and prosthetic reasons (21.5%). There was no significant difference across sex for reasons of extraction (p > 0.05). Significant differences (p < 0.001) were found for age (extraction due to periodontal disease increased with age); in patients attending in a single visit vs. patients attending a series of dental appointments (caries reasons were more common in patients having a single appointment vs. PD in those attending a series of appointments); for type of teeth (upper, posterior, and molars were extracted primarily because of caries, while lower, anterior and incisors were more often extracted because of PD). CONCLUSIONS: Dental caries was the most common reason for tooth extraction, followed by periodontal disease. Differences in the reasons for extraction were observed across patient characteristics and type of tooth.


Subject(s)
Dentition, Permanent , Tooth Extraction/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Mexico , Middle Aged , Young Adult
15.
Folia Histochem Cytobiol ; 50(3): 407-13, 2012 Oct 08.
Article in English | MEDLINE | ID: mdl-23042271

ABSTRACT

Activated protein C (APC) is generated from the cleavage of protein C by thrombin coupled to thrombomodulin and, subsequently, is released as protein C activation peptide (papC). The aim of this study was to evaluate the effect of papC on human dermal microvascular endothelial cells (HMEC-1), activated with 5 ng//mL TNF-α. Flow cytometry showed that papC inhibited the expression of VCAM-1 and ICAM-1, after activation with TNF-a. Similarly, RT-PCR analysis revealed that 2 and 4 pM papC inhibited the expression of VCAM-1 and IL-8 mRNA in TNF-α-treated HMEC-1. In addition, the expression of endothelial nitric oxide synthase(eNOS) increased in HMEC-1 treated with papC, compared to those without treatment. Furthermore, Jurkat cell adhesion to HMEC-1 induced by TNF-a was significantly inhibited after the addition of papC, compared to HMEC-1 without papC (p = 0.03). Finally, a control peptide analog to papC showed no effect on the expression of ICAM and VCAM on the surface of HMEC-1. In conclusion, our results suggest that papC exerts anti-inflammatory effects on endothelial cells.


Subject(s)
Dermis/blood supply , Endothelial Cells/metabolism , Intercellular Adhesion Molecule-1/metabolism , Interleukin-8/metabolism , Oligopeptides/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Vascular Cell Adhesion Molecule-1/metabolism , Amino Acid Sequence , Cell Adhesion/drug effects , Cell Adhesion/genetics , Endothelial Cells/cytology , Endothelial Cells/drug effects , Endothelial Cells/enzymology , Gene Expression Regulation/drug effects , Humans , Intercellular Adhesion Molecule-1/genetics , Interleukin-8/genetics , Jurkat Cells , Microvessels/cytology , Molecular Sequence Data , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Oligopeptides/chemistry , RNA, Messenger/genetics , RNA, Messenger/metabolism , Vascular Cell Adhesion Molecule-1/genetics
16.
Tohoku J Exp Med ; 217(3): 209-15, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19282656

ABSTRACT

The human coagulation factor VIII (FVIII) is essential in the intrinsic pathway of blood coagulation and circulates mainly as a non-covalently bound complex with the von Willebrand factor (VWF). This complex (FVIII/VWF) protects FVIII from degradation and cellular uptake, although no biological role has been identified yet for this complex. The FVIII/VWF complex was purified from a healthy donor's plasma by affinity chromatography on a Sepharose 4B-Concanavalin A column and was used to determine its capability to interact with erythrocytes and platelets. The purified FVIII/VWF complex at 6.0 and 12 microg/ml agglutinates rabbit and bovine erythrocytes, and showed negative agglutination with erythrocytes from other species including human ABO. Treatment of erythrocytes with Clostridium perfringens sialidase or trypsin increased four-fold the activity toward rabbit erythrocytes and positive agglutination for human A and B erythrocytes, suggesting the presence of FVIII/VWF-cryptic receptors in these erythrocytes. Goat, pig, or human O erythrocytes were not agglutinated even after enzymatic treatment. Fucose or N-acetyl-glucosamine (GlcNAc), at 10 mM, inhibited agglutinating activity of the complex with rabbit, human A and B erythrocytes, whereas galactose and N-acetyl-galactosamine, even at 200 mM, showed no effect on the complex activity. The FVIII/VWF complex, at 1.5 microg/200,000 platelets, significantly decreased platelet aggregation (p < 0.001) when compared with the effect of platelet-rich plasma; this effect was inhibited with 15 mM GlcNAc or fucose. ELISA assays on FVIII/VWF coated polystyrene plates confirmed specific binding to fucose- or biotinylated GlcNAc-dextran derivatives. We therefore propose that the FVIII/VWF complex possesses lectin activity.


Subject(s)
Factor VIII/metabolism , Lectins/metabolism , Multiprotein Complexes/metabolism , von Willebrand Factor/metabolism , Animals , Chromatography, Affinity , Enzyme-Linked Immunosorbent Assay , Erythrocytes/metabolism , Humans , Multiprotein Complexes/pharmacology , Platelet Aggregation/drug effects
17.
Tohoku J Exp Med ; 214(1): 11-6, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18212483

ABSTRACT

T-cell acute lymphoblastic leukemia is the most common form of cancer in children. Lectins are proteins or glycoproteins from plants or animals that recognize oligossacharides on the cell surface and have been used to characterize the structural changes of oligosaccharides in leukemias. In this study, we used the lectin from the freshwater prawn Macrobrachium (M. rosenbergii), specific for acetyl groups in sialylated glycans, because increased sialylation of glycoproteins and glycolipids has been identified in lymphoblastic leukemias. We compared the specificity of the M. rosenbergii lectin for lymphoblastic leukemias with the specificities of the lectins from Triticum vulgaris, Solanum tuberosum, Arachis hipogaea, and Phytolacca americana. By morphologic and phenotype characterization with a panel of monoclonal antibodies, we identified four types of leukemias from 106 leukemia patients: 11 cases of T-cell acute lymphoblastic leukemia, 61 cases of B-cell acute lymphoblastic leukemia, 24 cases of acute myeloblastic leukemia, and 10 cases of acute biphenotypic leukemia. As determined by cytofluorometric assays, nine of the eleven cases with T-cell acute lymphoblastic leukemia (8 +/- 3 years old) were specifically identified with the lectin from M. rosenbergii. In contrast, only six cases of B-cell leukemia, one case of myeloblastic leukemia, and 2 cases of biphenotypic leukemia were identified with this M. rosenbergii lectin. The other lectins tested showed no capacity to differentiate, in a significant manner, any of the four types of leukemias tested. Thus, the lectin from M. rosenbergii could be considered a useful tool for the diagnosis and study of T-cell acute lymphoblastic leukemia.


Subject(s)
Lectins , Leukemia, Biphenotypic, Acute/diagnosis , Palaemonidae/chemistry , Animals , Antibodies, Monoclonal , Antigens, Neoplasm/immunology , Child , Diagnosis, Differential , Flow Cytometry , Humans , Lectins/chemistry , Lectins/pharmacology , Leukocyte Common Antigens/analysis , Lymphocytes/drug effects , Lymphocytes/metabolism , Phenotype
18.
Indian J Ophthalmol ; 55(5): 349-53, 2007.
Article in English | MEDLINE | ID: mdl-17699943

ABSTRACT

BACKGROUND: Pterygium is one of the most common conjunctival diseases among ophthalmic pathologies. The frequency of recurrences is high, either after surgical treatment or after treatment combined with mitomycin C or beta-radiation therapy. AIMS: The purpose of this study was to determine whether concanavalin A (ConA) lectin bound to the pterygial surface can be used to detect recurrence or remnants of pterygium after surgical excision. MATERIALS AND METHODS: This was a prospective study on 20 patients with pterygium, divided in five stages, pre-surgery, early post-surgery (24h), late post-surgery (seven days), very late post-surgery (four weeks) and two months after the procedure. A drop of fluorescein-marked Con A (35 microg/mL) was instilled in the lower conjunctival eyelid sac and the eye was exposed to the light of a Wood's lamp for an average of five seconds. RESULTS: Out of the 20 patients, eight patients were found to have fluorescent stretch marks over the scar corresponding to residual pterygial tissue at four weeks; two months after the procedure of re-surgery we observed no fluorescent remnants. All residual pterygia were confirmed through histochemistry studies. CONCLUSION: It was possible to detect remnants of pterygium in postoperative patients and recurrences in early pre-clinical stages through the visualization of fluorescent ConA bound to the pterygial surface.


Subject(s)
Concanavalin A , Conjunctiva/pathology , Mitogens , Pterygium/diagnosis , Adolescent , Adult , Animals , Conjunctiva/surgery , Diagnosis, Differential , Disease Models, Animal , Follow-Up Studies , Humans , Middle Aged , Photomicrography , Postoperative Care/methods , Prospective Studies , Pterygium/surgery , Rats , Recurrence , Reproducibility of Results
19.
Biochim Biophys Acta ; 1760(8): 1235-40, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16762509

ABSTRACT

Differentiation of T lymphocytes is characterized by variable expression of CD8/CD4 co-receptor molecules and changes in the glycosylation pattern. In this work, O-glycosylation was analyzed in microsomes from murine thymocytes purified with the PNA and Amaranthus leucocarpus (ALL) lectins, specific for the T antigen (Gal beta1,3GalNAc1,0 Ser/Thr) in cortical and medullary thymocytes, respectively. Three peptides were used as acceptors for UDP-N-acetylgalactosamine: polypeptide N-acetylgalactosaminyl-transferase (GalNAc transferase); the peptide motif TTSAPTTS was the best glycosylated one. Cortical ALL-PNA+ thymocytes showed two-fold higher GalNAc transferase activity than ALL+PNA- thymocytes; however, capillary electrophoresis showed a higher proportion of di- versus mono-glycosylated peptides for ALL+PNA- than for ALL-PNA+. We compared the GalNAc transferase activity of thymocytes from dexamethasone-treated mice versus control mice. GalNAc transferase activity was six-fold higher in thymocytes from control mice than from dexamethasone-treated mice; the rate of di-glycosylated peptides for dexamethosone-resistant ALL+ was two-fold higher than for ALL- thymocytes. Our results confirm an upregulated biosynthesis of O-glycosidically linked glycans on T cell surface glycoproteins, and suggest that the modification of GalNAc transferase activity plays a relevant role during the maturation process of thymic cells.


Subject(s)
Thymus Gland/metabolism , Animals , Dexamethasone/pharmacology , Electrophoresis, Capillary , Glycosylation , Male , Mice , Mice, Inbred BALB C , Microscopy, Confocal , Microsomes/metabolism , Thymus Gland/cytology , Thymus Gland/drug effects
20.
Rev Gastroenterol Mex ; 69(3): 176-83, 2004.
Article in Spanish | MEDLINE | ID: mdl-15759791

ABSTRACT

Non-alcoholic steatohepatitis is a chronic disease that occurs in persons without significative consumption of alcohol, characterized by macrovesicular steatosis, mixed inflammatory infiltrate, and diverse degrees of fibrosis. It can progress to cirrhosis and its evolution to hepatocellular carcinoma has been described. It principally occurs in patients with obesity, diabetes mellitus, and hyperlipidemia, and is at present considered a manifestation of metabolic syndrome with insulin resistance. In pathogenesis, diverse factors, fundamentally insulin resistance as a mechanism that determines hepatic steatosis, have been described. Later, alteration of signalling cascades, oxidative stress, and other mechanisms occur that lead to inflammation, necrosis, and finally to hepatic fibrosis, the details of which will be described in this review.


Subject(s)
Fatty Liver/physiopathology , Clinical Trials as Topic , Humans , Insulin Resistance/physiology , Molecular Biology
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