PubMed Health⌕ Search

Biomedical subjects

M R Ferreira

Publications and source records attributed to M R Ferreira.

At least 19 recordsLinked to original sources
PubMed2001

The role of inadequate health literacy skills in colorectal cancer screening.

Colorectal cancer is ideally suited for early detection strategies that are likely to improve survival rates. Screening with either a fecal occult blood test (FOBT) or flexible sigmoidoscopy has been shown to identify precancerous polyps or cancers in early stages. However, persons with limited education and of lower socioeconomic status infrequently participate in screening programs in general and have very low rates of colorectal screening. Low literacy, which is common among persons with limited education and low income, may be an overlooked factor in understanding patients' decision making about colorectal cancer screening. This article provides information from focus groups about colorectal cancer screening, which we examine in the context of relevant literature on cancer screening and literacy. Using the health belief model, we examine the association between inadequate health literacy skills and low rates of colorectal cancer screening. The theoretical model also provides insights into strategies for improving knowledge, attitudes, and beliefs and screening rates for this challenging patient population.

Colorectal Neoplasms↗
PubMed2001

Shear bond strength of one-bottle dentine bonding systems.

The purpose of this in vitro study was to determine the shear bond strength (SBS) of composite resin to human, buccal dentine, using four one-bottle dentine bonding systems. Eighty recently extracted human molar teeth were embedded in metal rings by means of self-curing acrylic resin. The projecting buccal surfaces were ground wet on 600 grit silicone carbide paper in order to expose superficial dentine. The teeth were randomly divided into four groups (N=20): 1=Prime&tBond 2.1 (PB, Dentsply); 2=Scotchbond 1 (SB, 3M); 3=Optibond Solo (OS, Kerr) and 4=Syntac Single Component (SY, Vivadent). The dentine surfaces were etched, treated with one of the four dentine bonding systems, and cylinders of matching composites were then bonded to the surfaces by means of a silicone rubber split mould. All specimens were stored for 24 hours under water at 37 degrees C. The bonds were then stressed to failure with an Instron testing machine, operating at a crosshead speed of 0.5 mm/min. The data were statistically analysed (Kruskall-Wallis). The mean SBS (MPa) were: PB = 12.5 +/- 2.0; SB = 16.2 +/- 1.9; OS = 17.4 +/- 3.1 and SY= 8.1 +/- 1.9. There was a statistically significant difference (P = 0.0001) between the mean of SY and the other 3 groups, and also between PB and the other groups. There was no statistically significant difference (P = 0.244) between the SBS of OS and SB. SY demonstrated the lowest SBS.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1999

Racial variation in the use of laparoscopic cholecystectomy in the Department of Veterans Affairs medical system.

BACKGROUND: While studies have found racial differences in the rates of use of established invasive cardiac and cerebrovascular procedures, no study has evaluated racial variation in the rates of adoption of new surgical procedures. For patients undergoing laparoscopic cholecystectomy, the procedure represents a new and safe option that shortens the duration of postoperative hospitalization by almost one week. In this study, we evaluated whether, in the equal access Veterans Affairs (VA) medical system, the rate of adoption of this procedure and improvements in the duration of postoperative hospitalization differed between African-American and Caucasian patients. STUDY DESIGN: Data were obtained from two sources-administrative claims files and prospectively compiled dinical data from medical records and patient interviews. In both data sets, frequency of use, length of stay, and outcomes for African-American and Caucasian patients undergoing minimally invasive and open gallbladder surgery were analyzed for the first four years of use of the procedure in the VA system (1992 to 1995). RESULTS: Analyses based on claims files indicated that, after adjustment for potentially confounding variables, African-American patients who underwent cholecystectomy in VA medical centers were 25% less likely to undergo a minimally invasive cholecystectomy during the first 4 years of use of the new procedure (adjusted odds ratio, 0.74; 95% confidence interval, 0.66-0.83). Shortening of the average postoperative length of stay from 9 days or more in the prelaparoscopic era to less than 4.5 days for patients undergoing the laparoscopic procedure occurred in the first year for Caucasian patients, but did not occur until the fourth year for African-American patients (p<0.001). The overall difference in postoperative length of stay between African-American and Caucasian patients more than doubled from 1.7 days before introduction of laparoscopic cholecystectomy to 3.8 days in the fourth year. In comparison, analyses based on nurse-compiled clinical data indicated that, after adjustment for relevant clinical factors, racial variations in the rate of laparoscopic surgery were even larger (adjusted odds ratio for laparoscopic versus open cholecystectomy for African-American versus Caucasian veterans, 0.68; 95% confidence interval, 0.55-0.84). CONCLUSIONS: Compared to Caucasian patients, African-American patients who underwent cholecystectomy in VA medical centers had an approximately 25% to 32% lower likelihood of undergoing minimally invasive cholecystectomy procedures. The differences in rates of adoption of laparoscopic surgery did not appear to be from more comorbid illnesses among African-American patients. African-American and Caucasian veterans may differ in their preference for new surgical procedures like laparoscopic cholecystectomy. Conversely, VA physicians may have been less likely to recommend laparoscopic cholecystectomies to African-American patients.

Adult↗
PubMed1998

Relation between literacy, race, and stage of presentation among low-income patients with prostate cancer.

PURPOSE: Diagnosis of advanced prostate cancer is a major health problem, especially among low-income men. Opportunities vary for early detection of prostate cancer for low-income black and white men because of financial, cultural, and social factors. In this study, we evaluated the association of poor literacy skills with higher rates of presentation of advanced stages of prostate cancer among low-income black and white men who received care in equal-access medical systems. PATIENTS AND METHODS: Literacy and stage at diagnosis of prostate cancer were evaluated in 212 low-income men who received medical care in Shreveport, LA, and Chicago, IL. The patients' literacy was assessed with the Rapid Estimate of Adult Literacy in Medicine (REALM), an individually administered reading screening test designed specifically for use in the medical setting. Logistic regression models were used to evaluate predictors of metastatic disease at presentation as a function of patient age, race, literacy, and city. RESULTS: Whereas black men were almost twice as likely to present with stage D prostate cancer (49.5% v 35.9%; P < .05), they were significantly more likely to have literacy levels less than sixth grade (52.3% v 8.7%; P < .001). However, after adjustment for differences in literacy, age, and city, race was not a significant predictor of advanced-stage prostate cancer. CONCLUSION: Low literacy may be an overlooked but significant barrier to the diagnosis of early-stage prostate cancer among low-income white and black men. The development of culturally sensitive, low-literacy educational materials may improve patient awareness of prostate cancer and improve the frequency of diagnosis of early-stage cancer.

Adult↗
PubMed1997

The learning curve for laparoscopic colorectal surgery. Preliminary results from a prospective analysis of 1194 laparoscopic-assisted colectomies.

BACKGROUND: Laparoscopic-assisted colectomy is an emerging technology for patients with cancer, polyps, inflammation, and other types of pathologic conditions. While previous studies have shown better outcomes for laparoscopic cholecystectomies when surgeons perform more procedures, there is no information on the relationship between surgeon volume and outcomes for laparoscopic-assisted colectomy. OBJECTIVE: To evaluate whether better clinical outcomes are found for surgeons who perform higher numbers of laparoscopic-assisted colectomies and whether such a relationship, if it exists, applies to both intraoperative and postoperative outcomes. DESIGN: Analysis of a data set of 1194 patients, operated on by 114 surgeons, from a prospective registry sponsored by the American Society of Colon and Rectal Surgeons, from May 1991 to October 1994. MAIN OUTCOME MEASURES: Completion rate, intraoperative and postoperative complications, and length of hospital stay. RESULTS: In 75% of cases, surgery was completed laparoscopically, with no difference between high-volume surgeons (> or = 40 cases) and low-volume surgeons. Length of stay (average, 6 days) did not vary according to surgeon volume. Postoperative complications occurred in 15% of cases, with a significantly lower rate for high-volume surgeons (10% vs 19%; P < .001). Intraoperative complications occurred in 5% of cases, with a nonsignificant trend toward a lower rate for high-volume surgeons (3.7% vs 6.3%). A multivariate regression analysis, adjusting for type of disease (cancer vs inflammation vs polyps) and for level of difficulty of the procedure (high vs low) showed that for high-volume surgeons there is a lower probability of both intraoperative complications (adjusted odds ratio, 0.56; 95% confidence interval, 0.32-0.97; P = .04) and postoperative complications (adjusted odds ratio, 0.48; 95% confidence interval, 0.34-0.68; P < .001). CONCLUSIONS: There is a learning curve for laparoscopic-assisted colectomy with respect to intraoperative and postoperative outcomes. As with other laparoscopic procedures, surgeons who perform higher volumes of laparoscopic-assisted colectomy have lower rates of intraoperative and postoperative complications.

Colectomy↗
PubMed1997

Percentage cure of cement cured through various thicknesses of Cerec porcelain.

Highly filled luting resins are recommended for bonding porcelain restorations to tooth structure. This in vitro investigation was undertaken to determine the degree of cure of a 82 per cent filled dual-curing luting resin, after it was cured through various thicknesses of Cerec Vita Mark II porcelain. Infrared, as well as micro-Raman spectroscopy were used to determine the degree of cure of the cement at different time intervals after mixing and exposure to the curing light. The results indicated that Cerec porcelain thicknesses greater than 3 mm adversely affected the degree of cure of the luting resin, even at 24 hours after mixing the cement.

Analysis of Variance↗
PubMed1996

Allergies to dental materials.

Allergies related to dentistry generally constitute delayed hypersensitive reactions to specific dental materials. Although true allergic hypersensitivity to dental materials is rare, certain products have definite allergenic properties. Extensive reports in the literature substantiate that certain materials cause allergies in patients, who exhibit mucosal and skin symptoms. Currently, however, neither substantial data nor clinical experience unequivocally contraindicate the discontinuance of any of the materials, which include dental amalgam and nickel- and chromium-containing metals. The dentist forms a vital link in the team approach to the differential diagnosis of allergenic biomaterials that elicit symptoms in a patient, not only intraorally, but also on unrelated parts of the body.

Acrylic Resins↗
PubMed1996

Shear bond strength of a composite resin to differently silicoated base metal alloys.

This study was undertaken to determine the shear bond strength of Charisma composite resin to both thermal and pyrogenic silicoated base metal alloys namely, Duracast MS, Rexillium V and Wironit extra-hard. The bonded specimens were subjected to three stress treatments prior to shear bond testing. The results indicated that both silicoating techniques significantly improved shear bond strengths to sandblasted alloys, whereas wet heat and thermocycling treatments reduced the bond strengths, except for pyrogenic silicoated Wironit. Thermocycling was more detrimental to thermal than to pyrogenic silicoated Rexillium nad Wironit specimens.

Composite Resins↗
PubMed1996

The effect of the depth of dentine on shear bond strength of adhesive resins.

Dentine bonding agents require the use of a conditioner or primer which affects the adjacent dentine and/or smear layer. The appearance of superficial and deep dentine differs and this may affect the bond strength of adhesive systems. The purpose of this in vitro study was to investigate the bonding efficiency of two modern dentine bonding systems (DBS) i.e., Scotchbond Multi-Purpose (SBMP) and Imperva Bond (IB) when bonding composite resin, Z100 and Lite-Fil II, to firstly superficial and secondly to deep dentine. The bond strength values for SBMP to superficial and deep dentine were 24.7 MPa and 23.0 MPa respectively, and that of IB 19.3 MPa and 18.2 MPa. These differences were statistically significant for both products using the paired Student-t test (p < 0.05). Fractures sites were also examined in a SEM. For both products it was found that the samples which were bonded to the deep dentine showed lower bond strengths than those bonded to the superficial dentine.

Dental Bonding↗
PubMed1995

Analysis of 8-hydroxy-2'-deoxyguanosine in rat urine and liver DNA by stable isotope dilution gas chromatography/mass spectrometry.

A previously developed gas chromatographic/mass spectrometric method was applied to the measurement of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in rat liver DNA and in rat urine. For DNA samples, the method included: (i) fortification of samples with [15N]DNA (internal standard), (ii) enzymatic hydrolysis of DNA to deoxynucleosides, (iii) degradation of native nucleosides by treatment with trifluoroacetic acid and hydrazine, (iv) purification by C18 solid-phase extraction (SPE), (v) derivatization (acetylation followed by pentafluorobenzylation, Ac-PFB), and (vi) GC/MS analysis of the derivatives. For urine, the following methodology was used: (i) fortification of the samples with 8-18OHdG, (ii) prepurification by C18/OH SPE, (iii) derivatization, (iv) high-performance liquid chromatography purification of the Ac-PFB derivatives, and (v) GC/MS analysis. The precision of the method was demonstrated by carrying out replicate analysis of several urine and DNA samples: within-run and between-run variability was less than 5 and 8%, respectively. The analytical approaches were sufficiently sensitive to quantitate the urinary excretion of 8-OHdG (490 +/- 70 pmol/kg/24 h; sample size, 600 microliters urine) and to measure the level of 8-OHdG in liver DNA (20 8-OHdG/10(6) deoxynucleosides; sample size, 30 micrograms DNA) of rats not deliberately exposed to oxidative stress. Major advantages over previous methods are increased precision due to the use of proper isotopically labeled internal standards, and increased sensitivity due to the optimization of cleanup procedures. The simultaneous analysis of standards of three different oxidized nucleosides, namely 8-OHdG, thymidine glycol, and 5-hydroxy-methyl-2'-deoxyuridine, is shown.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1995

[Effectiveness of ciprofibrate. Open study in a Portuguese population].

STUDY OBJECTIVE: To determine the efficacy of ciprofibrate in portuguese patients with hypercholesterolaemia, hypertriglyceridaemia and mixed hyperlipidaemia. DESIGN: Open-label study with 6-month therapy. SETTING: Out-patient clinics of two Central Hospitals. PARTICIPANTS: Sequential sample of 40 patients 20 from each hospital. 37 patients (92.5%) completed the study; 14 had dyslipidaemia type IIa, 12 type IIb and 11 type IV. METHODS: After at least one month of diet or washout period, all participants were given 100 mg/day of ciprofibrate, taken after the evening meal. Analysis and clinical examinations were performed at weeks (-4), (0), (+8), (+16) and (+24). Total (TC) and HDL (HDL-C) cholesterol, triglycerides (TG), apoproteins A-I, B100, and (a), and fibrinogen were determined. LDL-cholesterol (LDL-C) was calculated by means of the Friedewald formula, whenever TG < or = 400 mg/dl. MAIN RESULTS: With ciprofibrate, in the whole population, TC, TG, LDL-C, apoB100, and TC/HDL-C ratio diminished, respectively 16.6%, 46.2%, 20.7%, 12.6% and 24.6%. HDL-C and apoA-I increased 10.4% and 4.2%. LDL-C was reduced by 29.5% (p = 0.0001) in type IIa patients, and increased 23% (not statistically significant) in type IV patients. The reduction of TG attained 57.4% in type IIb patients. One type IIb patient received 200 mg/day of the drug from week (+16) on. BMI, waist/hip ratio, hypertension, alcohol consumption and sex didn't affect ciprofibrate activity. CONCLUSIONS: These results confirm the high efficacy of ciprofibrate in patients with hypercholesterolaemia, hypertriglyceridaemia and mixed hyperlipidaemia. In type IIa dyslipidaemia, the reduction of LDL-C was roughly equivalent to that of the less potent statins. In type IV dyslipidaemia LDL-C may increase moderately. The influence on apoprotein (a) and fibrinogen was positive but modest.

Adolescent↗
PubMed1995

[Safety of ciprofibrate. Open study in a Portuguese population].

STUDY OBJECTIVE: To determine the safety of ciprofibrate in portuguese patients with dyslipidaemia. DESIGN: Open-label study with 6-month therapy. PARTICIPANTS: Sequential sample of 40 patients, 20 from each hospital, 37 patients (92.5%) completed the study. METHODS: After at least one month of diet or washout period, all participants were given 100 mg/day of ciprofibrate, taken after the evening meal. Analysis and clinical examinations were performed at weeks (-4), (0), (+8), (+16) and (+24). Glycemia, uric acid, creatine kinase, creatinine and transaminases were determined. MAIN RESULTS: Thirty-seven patients ended the study (92.5%), three abandoned because of gastrointestinal adverse effects, six other patients also complaint of gastrointestinal side effects. The creatinine and creatine kinase levels increased 9.7% and 19.2%, although kept in the normal range. There were no statistically significant changes in glycemia, uric acid and transaminases levels. CONCLUSIONS: These results confirm the high safety of ciprofibrate in patients with dislipidaemia. The short term of this study does not allows taking conclusions about long term use of this drug.

Adolescent↗
PubMed1994

Shear bond strength of a composite resin after delayed bonding to a polymerised dentine bonding system.

Polymerised adhesive may serve as a temporary sealant on prepared dentine surfaces and may be used as a precursor to the final bonding of a resin restoration. This procedure may, however, have an adverse effect on the strength of the final bond. This study was undertaken on 40 extracted human molar teeth to assess the effect of delayed bonding on the shear bond strength of a composite resin luted with a luting resin to abraded dentine treated with the Scotchbond Multi-Purpose (SMP) Bonding System (3M). No significant difference (p = 0.969) could be demonstrated between shear bond strengths achieved after immediate and delayed bonding to the polymerised Scotchbond Multi-Purpose adhesive.

Analysis of Variance↗
PubMed1987

[Werner's syndrome].

We describe a 35 year old woman with shortness of stature, skin and muscle atrophy of the face and lower limbs, peripheric arthropathies, feet deformity, plantar hiperqueratosis, alopecia, canities, bilateral cataracts and bitonal voice. At the age of 21, the patient started having plantar hiperqueratosis, deformity and stiffness of the feet joints. At the time of the examination the patient had neither diabetes mellitus, nor peripheric arteriopathies or neoplasms. There wasn't a family history and the parents weren't consanguinous.

Adult↗