Cell-free cartilage engineering approach using hyaluronic acid-polycaprolactone scaffolds: a study in vivo.

Polycaprolactone scaffolds modified with cross-linked hyaluronic acid were prepared in order to establish whether a more hydrophilic and biomimetic microenvironment benefits the progenitor cells arriving from bone marrow in a cell-free tissue-engineering approach. The polycaprolactone and polycaprolactone/hyaluronic acid scaffolds were characterized in terms of morphology and water absorption capacity. The polycaprolactone and polycaprolactone/hyaluronic acid samples were implanted in a chondral defect in rabbits; bleeding of the subchondral bone was provoked to generate a spontaneous healing response. Repair at 1, 4, 12, and 24 weeks was assessed macroscopically using the International Cartilage Repair Society score and the Oswestry Arthroscopy Score and microscopically using immunohistological staining for collagen type I and type II, and for Ki-67. The presence of hyaluronic acid improves scaffold performance, which supports a good repair response without biomaterial pre-seeding.

[Delayed healing in long bone fracture: radiologic course and treatment]. / Retraso de consolidación en fractura de hueso grande: evolución radiológica y tratamiento.

Isolated long bone fractures are unusual and may be missed in the initial X-rays, especially when they are minimally displaced. The delayed treatment of these fractures may cause various complications, such as delayed bone healing or seudoarthrosis, which are difficult to manage. Our clinical case shows delayed healing in a long bone fracture and how the radiologic course may assist in the therapeutic management of this complication.

Screening of extracts of algae from Baja California sur, Mexico as reversers of the antibiotic resistance of some pathogenic bacteria.

BACKGROUND AND OBJECTIVES: Sixty ethanol extracts of marine flora of Baja California Sur (Mexico) were screened to evaluate the reversing effect of the bacterial resistance to antibiotics in combination with a sublethal concentration of ampicillin or erythromycin. MATERIALS AND METHODS: The activity was assayed by using a modification of the classical agar-diffusion method against 3 resistant, pathogenic bacteria; Escherichia coil (ATCC BAA196), Staphylococcus aureus (ATCC BAA42), and Streptococcus pyogenes (ATCC BAA946). RESULTS: From the 60 ethanolic extracts, 12 (20%) of them in combination with ampicillin were able to reverse the resistance of Staphylococcus aureus and 8 (13%) with erythromycin yielded the same reversal with Streptococcus pyogenes. An extract from Sargassum horridum was the only one that reversed the resistance to antibiotics against both Staphylococcus aureus and Streptococcus pyogenes. CONCLUSIONS: Our findings suggest that some algae may be source of compounds with the potential to reverse the antibiotic resistance of some bacteria. In addition, of the assayed extracts, 35 (57%) showed inhibitory activity against Staphylococcus aureus, 48 (78%) were active against Streptococcus pyogenes, but none was active against Escherichia coil. The most active extracts were from Laurencia spp., Gelidium robustum, Chnoospora implexa, Padina mexicana, Gracilaria subsecundata, and Dictyopteris undulata.

Estudio de concordancia y reproducibilidad en la evaluación de las radiotransparencias humerales en las hemiartroplastias cementadas de hombro / Concordance and reproducibility in the assessment of humeral radiolucencies in cemented shoulder hemiarthroplasties

Objetivoevaluar la concordancia y la reproducibilidad en las observaciones de las líneas de radiotransparencia del componente protésico humeral en las hemiartroplastias cementadas de hombro. Material y métodocinco observadores han evaluado 128 radiografías obtenidas de 32 hemiartroplastias cementadas de hombro en dos momentos del seguimiento evolutivo en proyecciones anteroposterior y perfil de escápula, con una reevaluación a las 3 semanas. Se han evaluado las líneas de radiotransparencia en 7 zonas alrededor del implante en las interfaces cemento-hueso y cemento-implante. Se han clasificado las radiotransparencias en cuatro categorías según el tamaño en milímetros. Se han evaluado los resultados con el método estadístico kappa. Resultadosen el estudio de la reproducibilidad intraobservador se han obtenido para las interfaces implante-cemento y cemento-hueso índices kappa de 0 a 0,6. En el estudio de la concordancia entre observadores para cada una de las zonas e interfaces el 65% de los índices kappa obtenidos oscilan entre 0 y 0,4. La capacidad intraobservador de seguimiento en el tiempo de un mismo paciente se ha evaluado por el porcentaje de respuestas posibles de cada observador que ha oscilado entre el 85 y el 90%. Conclusioneshay un bajo índice de concordancia y reproducibilidad al analizar las radiotransparencias tanto en la interfaz hueso-cemento como en la de cemento-implante. También hay un bajo índice de errores al analizar la evolución de las radiotransparencias en dos radiografías del mismo implante obtenidas en dos momentos diferentes en el tiempo

Purpose: To assess concordance and reproducibility in the observation of radiolucent lines of the humeral prosthetic component in cemented shoulder hemiarthroplasties. Materials and methodsFive observers evaluated 128 X-rays obtained from 32 cemented shoulder hemiarthroplasties at 2 points of time Turing follow-up in anteroposterior and scapular profile views; a re-evaluation was made after 3 weeks. Radiolucent lines were studied in 7 areas around the implant at the cement-bone and cement-implant interfaces. Radiolucencies were classified into 4 categories according to their size in millimeters. Results were assessed with the kappa statistical method. ResultsIn the study of intraobserver reproducibility kappa indices of 0 to 0.6 were obtained for the implant-cement and cement-bone interfaces. In the study of interobserver concordance for each of the areas and interfaces, 65% of kappa indices obtained range between 0 and 0.4. Intraobserver capacity to follow up one same patient in time was assessed on the basis of the percentage of possible responses by each observer, which ranged between 85 and 90%. ConclusionsThere is a low rate of concordance and reproducibility when analyzing radiolucencies both at the bone-cement and at the cement-implant interfaces. There is also a low error index when analyzing the evolution of radioludencies in 2 X-rays of the same implant obtained at 2 different points in time (AU)

Fracturas diafisarias de húmero en mayores de 60 años: enclavado intramedular rígido / Rigid intramedullary nailing of humeral shaft fractures in patients older than 60

Objetivo. Valorar retrospectivamente el tratamiento mediante un enclavado endomedular rígido de las fracturas diafisarias de húmero en mayores de 60 años. Material y método. Entre 1997 y 2002 se trataron en nuestro centro 33 pacientes afectos de fractura diafisaria de húmero con una edad media de 72, 8 años (R = 60-89). Se utilizaron 11 clavos de Russell Taylor, 16 de Seidel y 6 UHN. Se ha analizado el tiempo e incidencia de consolidación, las complicaciones intraoperatorias, postoperatorias y tardías, así como los resultados funcionales mediante la escala de Rodríguez-Merchán y se ha estudiado la recuperación del estado funcional previo. Resultados. La tasa global de consolidación fue del 87,8% en un tiempo medio de 13,5 semanas (R = 8-40). Las complicaciones intraoperatorias fueron 1 parálisis transitoria del nervio radial y 7 problemas técnicos. Como complicaciones tardías hubo 1 caso de infección, 5 síndromes dolorosos de hombro, 3 pseudoartrosis y se retiraron 7 clavos. Los resultados funcionales según la clasificación de Rodríguez-Merchán fueron excelentes o buenos en el 75,7% del total de pacientes. El grupo tratado con Russell Taylor o UHN presentó un 88,2% de excelentes o buenos resultados frente a un 62,5% de los tratados con el clavo Seidel (p = 0,09). El 88,2% del grupo tratados con Russell Taylor o UHN recuperaron el estado funcional previo frente al 56,3% de los tratados con el clavo Seidel (p = 0,046). Conclusiones. Los resultados sugieren que el tratamiento de las fracturas diafisarias de húmero mediante un enclavado endomedular rígido encerrojado proximal y distalmente es una opción terapéutica válida a considerar en mayores de 60 años

Purpose. To retrospectively assess rigid intramedullary nailing of humeral shaft fractures in patients over 60 years of age. Materials and methods. 33 patients of a mean age of 72.8 years (range: 60-89) with a humeral shaft fracture were treated in our hospital between 1997 and 2002. 11 Russell Taylor, 16 Seidel and 6 UHN nails were used. Osseointegration time and incidence data were examined as well as intraoperative, postoperative and late complications and the functional results obtained were assessed by means of the Rodríguez-Merchán scale. The degree of recovery of the earlier functional condition was also considered. Results. Healing was achieved globally in 87.8% of cases in an average period of 13.5 weeks (range: 8-40). Intraoperative complications were: one case of transient radial nerve palsy and 7 technical problems. As regards late complications, there was one case of infection, 5 painful shoulder syndromes, 3 pseudoarthroses and 7 nails had to be retrieved. According to Rodríguez-Merchán's classification, functional results were good to excellent in 75.7% of patients. The group treated with Russell Taylor or UHN nails had 8.2% of good to excellent results as compared with 62.5% for patients treated with the Seidel nail (p=0.09). 88.2% of patients in the Russell Taylor-UHN group recovered their earlier functional condition as compared with 56.3% of those treated with the Seidel nail (p = 0.046). Conclusions. Results suggests that treatment of humeral shaft fractures by means of rigid intramedullary nailing with proximal and distal locking is a valid therapeutic option to be considered in patients older than 60

Moderate-to-severe diabetic retinopathy is more prevalent in Mexico City than in San Antonio, Texas.

OBJECTIVE: To compare the prevalence of diabetic retinopathy (DR) between low-income Mexicans from Mexico City and Mexican-Americans from San Antonio, Texas. RESEARCH DESIGN AND METHODS: We designed a cross-sectional population-based study in low-income neighborhoods of Mexico City and San Antonio. The men and non-pregnant women included in the study had NIDDM and were between 35 and 64 years of age. Ophthalmologic evaluation was performed in 414 patients, 204 in San Antonio and 210 in Mexico City. Seven field standard stereophotographs of each eye were obtained, adapting the Early Treatment Diabetic Retinopathy Study protocol, and graded at the Fundus Photograph Reading Center of the University of Wisconsin. RESULTS: Early nonproliferative DR occurred in 37 (17.6%) and 39 (19.1%) patients in Mexico City and San Antonio, respectively. Moderate-to-severe nonproliferative DR occurred in 55 (26.2%) and 37 (18.1%) patients in Mexico City and San Antonio, respectively, and proliferative DR occurred in 12 (5.7%) and 7 (3.4%) patients in Mexico City and San Antonio, respectively. Using univariate and multivariate logistic regression analysis with DR as the dependent variable, age, duration of disease, and fasting glucose concentration were positively and significantly associated with retinopathy, whereas city, systolic blood pressure, and other selected metabolic variables were not. We defined moderate-to-severe DR to include the categories of moderate-to-severe nonproliferative and proliferative DR. For this combined category, Mexico City patients with diabetes had a significantly higher prevalence (P < 0.01) than those from San Antonio when analyzed by multiple logistic regression analysis (odds ratio for Mexico City/San Antonio, 1.72; 95% CI 1.10-2.70). CONCLUSIONS: Overall prevalence of DR is similar in both cities. However, moderate-to-severe DR is significantly higher in Mexico City.

A diabetic retinopathy screening program as a strategy for blindness prevention.

The most frequent cause of preventable blindness in adults, in the developed world, is diabetic retinopathy (DR). The early treatable phase of this complication is clinically silent. In order to institute effective laser photocoagulation and prevention of blindness, timely detection is crucial. Consequently there is a need for periodic funduscopic examinations of all diabetics. Due to the high prevalence of DM in Mexico most of the primary care facilities are limited. We present the results of a DR screening program (DRSP) using a mobile unit equipped with a fundus photography camera, parked outside of a clinic. We report the prevalence of the various stages of DR and clinical characteristics observed in this population as well as our experience working in such an environment. The study period was from September 1 to December 22, 1995. All the diabetics that presented for care to the clinic were identified and all other persons were invited to participate. A total of 231 participants were invited (112 men, 119 women). Non-stereo fundus photos of two retinal fields (macula and optic disk centered) were taken with technique and classification according to international standards. Response rate to the invitation was 95.3%. Mean age was 62.4 +/- 13 years and 63.5 +/- 10 years and duration of diabetes was 12.3 +/- 10.1 years and 11.0 +/- 7.5 years for men and women, respectively. DR was detected in 38% of the cases, of these only 5.6% have received treatment. DR was uncovered in 84.5% of the cases and was associated with duration of diabetes (p < 0.001 in men and p = 0.04 in women) and hyperglycemia (in men p < 0.005, only). DR has a high prevalence in this population and can be detected through a screening program which reveals undiagnosed high risk DR in an efficient, and standardized manner.

High prevalence of cholelithiasis in a low income Mexican population: an ultrasonographic survey.

The authors present the results of a population-based survey of cholelithiasis carried out in a low-income area of Mexico City using high-resolution gallbladder ultrasound. The purpose of the study was to estimate the prevalence and selected associated risk factors of cholelithiasis (CL). The population of the studied area was 15,532 subjects, of whom 3,505 (22.6%) were eligible for the baseline survey (men and non-pregnant women between 35-64 years of age). Of this group, 1,735 (76.03%, 702 men and 1,033 women) were located for a follow-up study. Ultrasonography was performed on all except for 100 subjects who had undergone previous cholecystectomy. Crude prevalence of CL was 14.1% (95% CI 12.5-15.5). The prevalence was 5.8% (95% CI 4.1-7.5) in men and 19.7% (95% CI 17.3-22.1) in women. Presence of gallstones was associated with age, sex (men p<0.006, women p<0.001), and multiparity (p<0.002). Centrality index in men and body mass index in women were positive and significantly associated with CL when compared with subjects without CL. High levels of fasting and post-glucose load insulin in women and men respectively were associated with CL. The authors conclude that the population of this study has a high prevalence of CL and confirm some known risk factors such as age, sex, BMI and multiparity. Proper assessment of the magnitude problem and characterization of potentially modifiable risk factors will play a major role in preventing this pathology.

Undiagnosed hypercholesterolemia: a serious health challenge. The Mexico City Diabetes Study.

In this report we present the results of a population based survey designed to characterize the prevalence of hypercholesterolemia (HCL: total cholesterol > or = 240 mg/dl) in a low income urban area of Mexico City (The Mexico City Diabetes Study). In an area of 15,532 inhabitants, 3505 (22.57%) were found to be study eligible (all 35-64 year-old men and nonpregnant women residing in the area permanently). A home interview was obtained in 2813 (80.26%) subjects. A physical exam and oral glucose tolerance test was performed on 2282 (81.2% of the individuals that gave the interview and 65.1% of all study eligibles, 941 men and 1341 women). The crude prevalence of HCL for men in this group was 12.3% and for women 12.5%. Severe HCL (total cholesterol > or = 260 mg/dl) was found in 6.6% of men and 6.5% of women. In the older age group (55-64 years) prevalence in women reached 21.1%. Of the individuals with HCL this abnormality was previously diagnosed in only 15.9% of men and in 7.8% of women. Despite having been diagnosed, the abnormality remained untreated in all cases. HCL was associated with higher mean systolic blood pressure (in women), higher mean diastolic blood pressure (in men) and higher mean fasting and 2 h post-glucose load glycemia as well as post-challenge insulinemia in both sexes. Mean TG was found high in both groups (with and without HCL), but in subjects with HCL the values were significantly higher. We conclude that HCL is very common in this population. The majority of the cases remained undiagnosed and of the small fraction of subjects that have been diagnosed, virtually none is under medical care. It is necessary to design and implement a national program to reduce the impact of this serious health problem.

Nephropathy in low income diabetics: the Mexico City Diabetes Study.

Among the most serious complications associated with diabetes mellitus (DM) is nephropathy (DN). In Mexico, there is little information on the frequency and clinical characteristics of DN in the Mexican population. We present results of a population-based survey designed to estimate the prevalence of DN. The low income population consisted of 15,532 inhabitants. All 35- to 64-year-old males and non-pregnant women residing in the survey area were identified as eligible for the study (3505; 22.6%). A home interview was obtained in 2810 (80.2%). A physical exam with oral glucose tolerance test was obtained in 2282 (81.2% of those interviewed). DM was diagnosed in 304 (crude rate 13.3%). Mean age for men and women with DM was 51.6 +/- 8.4 and 52.2 +/- 7.5, respectively. Duration of DM in men was 9.2 +/- 8.1 and in women, 7.3 +/- 6.7 years. Hypertension was diagnosed in 19.8% of men and 18.1% of women. Diabetic retinopathy of any level was found in 55.4% of men and 45.7% of women. Mean glycohemoglobin in men was 9.6 +/- 2.1 and in women 9.5 +/- 2.2% (normal 4-8%). At baseline, proteinuria (1+ or more, by dipstick) was found in 24.7% of men and 9.6% of women, microalbuminuria (MA) in 84.4% of men and 63.8% of women. Quantitative albuminuria was abnormally high in 54.7% of men and 40.3% of women. In the 203 diabetics studied with 24 h urine collection for creatinine clearance, normal renal function was found in 69.1% of men and 47.5% of women, reduced renal function was found in 26% of men and 50% of women, renal insufficiency was diagnosed in 4.9% of men and 1.6% of women. One patient was on dialysis and in a subsequent follow up, we found that 2.3% of the patients had died of renal failure, six men (46-63 years) and a woman of 62 years. We conclude that DN is a very serious threat to this population. The high case fatality rate associated with this condition maintains a low prevalence. It is important to develop a program to diminish the frequency of this condition.

Concordance between retina specialists and a preferred practice pattern in treatment and follow-up criteria for diabetic retinopathy. The Mexico City Diabetes Study Retinopathy Group.

Proper detection, adequate laser therapy and follow-up of diabetic retinopathy (DR), using guidelines established by landmark studies, are important to prevent blindness. In this report we analyze the agreement between 11 retina specialists and the Preferred Practice Pattern of the American Academy of Ophthalmology in the therapeutic and follow-up criteria for DR. Color fundus stereophotographs of seven standard fields of each eye of 15 diabetics were sent to 11 retina specialists. Their treatment and follow-up criteria were surveyed. For treatment of DR mean percent agreement was 65%. Kappa statistic, which corrects for chance agreement, was between -0.23 and 0.63 with a mean of 0.26. The therapeutic recommendations for macular edema were analyzed separately and the mean kappa was between -0.10 and 0.71 with a mean of 0.32. With respect to recommendations for interval until follow up, following initial visit, mean percent agreement was 73% with a kappa statistic between -0.22 and 0.33 and a mean of 0.07. Based on conventional interpretation of kappa statistic these mean values are in the range of poor agreement. Since there is a significant discrepancy in the concordance level in both therapeutic and follow-up recommendations for the management of DR, there is a need to improve agreement in these criteria, since these are key elements in the decision making process of the specialist caring for diabetic patients.

Prevalence of gallbladder disease and associated clinical variables in a low income population of Mexico City.

We present the results of a population-based survey carried out in a low income area of Mexico City. The aim of this study is to characterize the prevalence of clinically significant gallbladder disease (CSGD) using the self-reported history of cholecystectomy (CG) or cholelithiasis (CL) demonstrated by cholecystography and/or ultrasonography. The population of the studied area was 15,532 inhabitants, of whom 3505 (22.6%) were age eligible (35-64 year-old men and non-pregnant women). Home interviews were obtained in 2810 (80.2%). A physical and laboratory examination was performed in 2282 individuals (65.1%; 941 men and 1341 women). The prevalence of CSGD in men was 2.0% (95% confidence intervals 1.1-2.9%) and 9.2% in women (95% confidence intervals 7.7-10.7%). Patients with CSGD were older, men (p < 0.003) and women (p < 0.001). Women with CSGD had higher waist to hip circumference ratio (p < 0.06), higher fasting glucose (p < 0.03) as well as 2 h post challenge glycemia (p < 0.04) and insulinemia (p < 0.03). In the multiple logistic regression model only age (p < 0.001) and sex (p < 0.001) remained significantly associated. We conclude that CSGD is quite prevalent in this population. It is associated with age in both genders and in women, higher glucose and insulin levels. The prospective follow-up of this cohort is important since it could generate the information needed to implement a preventive program to diminish the impact of this condition.

The insulin resistance syndrome in Mexico. Prevalence and clinical characteristics: a population based study.

The insulin resistance syndrome (IRS) is recognized as a harbinger of serious morbidity and high mortality. No published data on the prevalence of the IRS in the Mexican population exist. We estimated the prevalence of the IRS in an area that had 15,532 inhabitants, 3505 (22.6%) of whom were eligible (35-64 years of age, men and non-pregnant women). Interviews were obtained on 2810 (80.2%), a physical and laboratory examination with oral glucose tolerance test, insulin determinations and lipid profile was performed on 2282 individuals, 81.2% of those interviewed, 65.1% of eligibles. The IRS was defined as the coexistence of the triad: hypertension, glucose intolerance (diabetes or impaired glucose tolerance) and dyslipidemia (triglycerides > or = 200 mg/dl and HDL < 35 mg/dl). Using this diagnostic criteria the prevalence of IRS in the general population was 2.97% for men and 3.21% for women. In subjects with impaired glucose tolerance (IGT), the IRS was identified in 11.7%. In diabetics, IRS occurred in 13.7%. Subjects with IRS (IGT and diabetics) were significantly more obese (BMI 30 +/- 4.3 vs. 28.4 +/- 4.2 kg/m2 p < 0.001), had central upper body fat pattern distribution (sub/tri skinfolds 1.66 +/- 1.1 vs. 1.5 +/- 0.7 p < 0.02), (waist/hip circumferences 1 +/- 0.07 vs. 0.97 +/- 0.07 p < 0.001) and hyperinsulinemia fasting and post glucose load (25 +/- 17 vs. 15 +/- 13 p < 0.001, 157 +/- 92 vs. 85 +/- 72 p < 0.001, respectively). We conclude that the prevalence of IRS is high, individuals with IRS in Mexico have an anthropometric profile characterized by central, upper body obesity. A significant proportion of the patients with IGT and DM are at the highest cardiovascular risk.

Carotid artery atherosclerosis in a Mexico City population with high carbohydrate intake.

We present the results of a population based survey designed to estimate the prevalence and clinical characteristics of carotid artery atherosclerosis (CAS) diagnosed using vascular ultrasonography (VUS) in a low income area of Mexico City encompassing six neighborhoods that we previously studied. We attempted to locate all the non-diabetic participants of the first two neighborhoods (n = 834) and all diabetics from the six neighborhoods (n = 304). We located 1078 (94.7%) participants and examined 770 (71.4%). All study subjects were men and non-pregnant women between 35-64 years of age and had standardized VUS protocol. In men, the prevalence of CAS was 16.29%, in women the prevalence was 12.3%. CAS was significantly associated in both sexes to age (p < 0.001) and systolic blood pressure (p < 0.001). The ratio of the subscapular to triceps skinfolds was significantly higher in men with CAS (p < 0.04). In women, fasting glucose was higher in subjects with CAS (p < 0.04). The lipid profile was similar in men with and without CAS. However, women with CAS had significantly higher total cholesterol (p < 0.001), LDL cholesterol (p < 0.002), VLDL cholesterol (p < 0.092) and mean TG (p < 0.033). The percent of patients with hypertension, tobacco use, myocardial infarction and diabetic retinopathy of any degree was significantly higher in the subjects with CAS. CAS of any degree was observed in 12.4% of the non-diabetic population and 18.13% of the diabetics.(ABSTRACT TRUNCATED AT 250 WORDS)

The level of metabolic control in low income Mexico City Diabetics. The Mexico City Diabetes Study.

The importance of good metabolic control in the treatment of diabetes mellitus (DM) is unquestionable. Measurements of the level of control (LC) are available such as glycohemoglobin (GH) and fructosamine (FA). The aims of this study are: to estimate LC in a population based case series of type II DM patients, to assess the effect of clinical, metabolic and sociodemographic variables usually associated with the LC and to estimate the clinical impact of the LC on vascular complications of DM. A low income area of Mexico City was enumerated. All males and non-pregnant females between 35-64 years of age were considered eligible. Home interview was obtained in 2813 and a medical exam including an oral glucose tolerance test was performed in 2282 (65.1%). Three hundred and four subjects met the criteria (WHO) for DM. Three years later, 213 (70.1%) were located for GH and FA measurements. Cases were divided according to the level of GH: Group I, good LC (GH < or = 8.6%, n = 66); and group II poor LC (GH > or = 8.7%, n = 147). A significant difference was observed in the mean value of FA between groups (Group I 255 +/- 52.3 mumol/dl. Group II 306.4 +/- 51.1; p < 0.001). In comparison with subjects with good LC, patients with poor LC had higher values of duration of DM (p < 0.01), waist/hip ratio (p < 0.04), fasting glucose (p < 0.001) and lower values of fasting insulin (p < 0.07), LDL cholesterol (p < 0.006) and VLDL cholesterol (p < 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)