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Biomedical subjects

J F Santos

Publications and source records attributed to J F Santos.

At least 37 records · Page 2Linked to original sources
PubMed1981

Suicide among minority elderly: a preliminary investigation.

In the United States, suicide has traditionally been considered a White elderly phenomenon. Suicide rates have been increasing for Nonwhites in recent years, but it is not clear how this may have affected the age distribution, particularly for specific Nonwhite groups. An investigation of official 1976 suicide statistics among minority elderly revealed that suicide rates are also highest among the old for Chinese-, Japanese- and Filipino-Americans. Among Blacks and Native Americans, however, suicide rates are extremely low for the aged. Explanations for these findings are suggested and the need for a long-term study is indicated.

Acculturation↗
PubMed1978

Punch shear strength of polycarboxylate cements.

Two general conclusions are drawn which apply to all the four commercial polycarboxylate cements: First, the effect of storage condition upon shear strength was much more pronounced after 24 hours than after 1 hour of storage time; second, the effect of storage condition was most extreme when the specimens were tested free of their matrices. Additionally some specific comparisons between the four products tested can be made based on differences of shear strength within the same experimental condition. The effect of confinement decreased in the following order: Boston greater than Bondal greater than PCA greater than Durelon. Sensitivity to storage conditions decreased in this order: Durelon greater than Bondal greater than PCA greater than Boston. Finally sensitivity to storage times decreased in the order Bondal greater than Durelon greater than Boston greater than PCA.

Acrylic Resins↗
PubMed1976

Influence of recall on reliability of perception of the autokinetic illusion.

An autokinetic test was given to 76 females subjects who were then randomly assigned to 1 of 4 groups of 19 subjects each. Two groups were retested after 1 and 6 wk., respectively. The other two groups were asked to recall their initial experience after 1 and 6 wk., respectively. Intertrial correlations of the measures were generally higher for the recall conditions than for the retest conditions. The results were discussed in terms of the potential influence that recall may have on the test-retest reliability of autokinesis.

Adolescent↗
PubMedDate not supplied

Methods of suicide by age: sex and race differences among the young and old.

The elderly have the highest suicide rate in the United States. In partial explanation of this finding, a common statement in the suicide literature is that older persons tend to use more drastic and effective methods of suicide. However, little, if any, data have been presented in defense of this explanation. In order to investigate the validity of this contention, annual official statistics for specific methods of suicide (firearms, hanging, poisons) by age for different sex and racial groups (whites, blacks, nonwhites excluding black) were examined from 1960 to 1978. Comparisons among the age-sex-race groups, along with trends over time and differences in the methods employed, were noted. For white males, blacks of both sexes, and nonwhites excluding black females, the findings confirmed the use of more violent methods by the elderly than by the young in terms of the proportion of suicides by firearms and/or hanging. Less support and, in fact, opposite results for method-related age differences were obtained for white females and nonwhites excluding black males. Another general finding was an increase in the use of firearms for most of the groups studied. The need for data for specific groups within the nonwhite category excluding blacks is apparent both from the available literature and from the present findings. Possible explanations and implications of the observed results are discussed.

Adolescent↗
PubMedDate not supplied

Atrial flutter ablation with a new radiofrequency catheter.

OBJECTIVE: To assess the performance of a new radiofrequency catheter, specially designed for inferior vena cava-tricuspid annulus (IVC-TA) isthmus ablation, in the treatment of atrial flutter. PATIENTS: IVC-TA isthmus ablation was performed in thirteen patients, eleven men and two women, aged 60 +/- 12, with a diagnosis of typical atrial flutter, symptomatic despite anti-arrhythmic therapy. The flutter was present for more than one year in seven patients and was paroxysmal in the remainder. The echocardiogram showed atrial enlargement in six patients. Atrial flutter was an isolated phenomenon in seven patients and in the remainder was associated with arterial hypertension (two patients), ischemic heart disease (two patients) and dilated cardiomyopathy (two patients). METHODS: In the electrophysiologic study four diagnostic catheters were used, including one duodecapolar for mapping the tricuspid annulus. In the patients who presented with sinus rhythm, atrial flutter was induced with programmed atrial stimulation, and then the atrial activation circuit was mapped. To demonstrate the entrainment phenomenon the IVC-TA isthmus was over-stimulated, to prove that this was the slow zone of the circuit. The radiofrequency energy was applied in the IVC-TA isthmus with the Medtronic Cosio-Fluttr ablation catheter, for 60 sec per application, with temperature control and with a maximum energy output of 50 W. Criteria for success were not only the disappearance of the atrial flutter during the application of radiofrequency energy, but also the demonstration of bi-directional IVC-TA isthmus block. RESULTS: The primary success rate was 100%. The mean procedure time was 110 +/- 22 min, mean fluoroscopy time was 23 +/- 4 min and the number of radiofrequency energy pulses was 9 +/- 3. There were no complications. The patients were followed for a mean time of 8 +/- 4 months and atrial flutter recurred in only one patient (8%). CONCLUSIONS: Atrial flutter ablation with the new Medtronic Cosio-Fluttr catheter, specially designed for the application of radiofrequency at the IVC-TA isthmus, is a safe procedure and has a high success rate. It simplifies ablation, decreasing the number of radiofrequency energy pulses, without using long sheaths and keeping short procedure and fluoroscopy times.

Adult↗
PubMedDate not supplied

Effectiveness of three mouthrinses to inhibit acid formation by dental plaque under home-use conditions.

A study was conducted to assess the effectiveness of three mouthrinses (Plax, Cepacol and Fluordent) to inhibit acid formation from plaque collected from 21 volunteer dental students. Plaque was collected on each side of the mouth, two hours after breakfast, once-a-week, after a period of 48 hours without any oral hygiene other than the use of the mouthrinses. Initial pH and the change in pH of plaque incubated with sucrose were recorded up to 120 min. Excepting Cepacol for the first week only, no inhibitory effect on acid formation was observed.

Adolescent↗
PubMedDate not supplied

[Consistency of zinc oxide-eugenol impression materials].

The purpose of this work was investigate the consistency of three zinc oxide-eugenol impression pastes, considering its flow. Flow tests were performed based on the AMERICAN DENTAL ASSOCIATION-Specification no 16. Setting time was based at that one when should be applied the load to get considered disc diameter; the values were obtained graphically. Considering the results it was possible to conclude: a) the first two materials (Equalizing and Horus) present high initial flow, which however drops down earlier on the second one; b) both materials may be used with non compressive impression technic but the second one has shorter working time; c) the third material (Lysanda) as it presents lower flow and faster setting time, may be used with compressive impression technic.

Dental Impression Materials↗
PubMedDate not supplied

[Porcelain veneers].

Through a clinical situation is shown the technique for the placement of a porcelain bonded veneer. Its significance with in the Esthetic Restorative Dentistry, advantages and disadvantages are emphasised. Together with the clinical procethe laboratorial steps are also shown. It was concluded that the bonded porcelain veneers are new options for a Restorative Dentistry more conservative with excellent esthetic results.

Acid Etching, Dental↗
PubMedDate not supplied

[Influence of escape channels (vents) in reproduction of occlusal contacts and external surface of complete cast metal crowns].

The purpose of this investigation was to verify the influence of ventings on the reproduction of interocclusal contacts from the wax pattern to the cast crown and also to note the influence on surface quality. Comparatively were performed tests with no venting, with one joined on the outside of the full crown wax pattern and two ventings joined on the sprues (Fig. 2). The castings were obtained with a nickel-chrome alloy and investing was performed with phosphate bonded investment. From the results it was possible to conclude: casting without venting presented higher frequency of no reproduction of interocclusal contact points; when using one venting, joined on the outside of the crown wax pattern, the reproduction of the interocclusal contacts was 100%, the venting did not lead to high improvement on the surface quality.

Chromium Alloys↗