Biomedical subjects
Publications and source records attributed to R Casella.
We describe a rare variant of carcinoma of the ampulla of Vater. A 70-year-old man with several illnesses and a newly appeared jaundice was investigated and a signet-ring cell carcinoma of the ampulla of Vater diagnosed. We performed a local transduodenal excision. One year after operation the patient is asymptomatic. This is the second case report in the literature.
The extent to which a toothbrush is worn out, as evidenced by bristle splaying, is an important determinant of cleaning efficacy. In order for this aspect of oral hygiene to be studied, an accelerated means of producing a life-like pattern of bristle splaying was investigated and compared with splaying induced by a human test-panel. Porcelain denture teeth were brushed under a static applied load in a slurry of dentifrice, by means of a revolving "figure 8" motion, for up to 12,000 revolutions. This was found to induce an increase in the degree of splaying (as measured by "wear index") that was well-fitted (R2 = 0.96) by a second-order expression of the form: WI = WIi + Ritj - Ctj2 where WI = wear index, WIi = initial wear index, Ri = initial rate of increase in WI, tj = brushing time measured in either machine revolutions (tr) or weeks of human use (tw), and C = a separate constant for each brushing mode (machine or human panel). The rate of splaying was found to be strongly influenced by the quality of the bristle filament, but not by small differences in toothbrush design. The splaying pattern induced by the machine could not be distinguished visually from that in a set of brushes used at home by human volunteers. A strong correlation was found between the splaying produced by machine-brushing and by a panel who brushed free-style at home for 13 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
Pulmonary blastoma--so called because of its histological resemblance to fetal lung--is a rare malignant neoplasm, which tends to relapse locally and metastasize mainly in the first years, has a poor 5-year prognosis, and shows a potential radio-chemosensitivity. We report our findings and therapeutic approach in a case of a 64-year-old male.
Two cases of gall-stone ileus during the past months have encouraged us to discuss the epidemiology, pathogenesis, diagnosis and therapy. This pathology is not as rare as one thinks and represents 23% of cases of mechanical ileus of the small intestine in patients over 65 years of age, thus being the third cause after stenosis due to carcinoma and incarcerated hernia. The importance of this illness is due to two factors: the diagnostic difficulties because of a periodic symptomatology with often a lack of typical radiologic signs and the still important mortality of 5 to 10% today. We present the casuistic of seven cases which have occurred over the last 15 years in our hospital and compare our experience with those of the literature. We discuss the therapeutic problem of enterolithotomy or one-stage repair. The main point for a reduction in mortality is an early diagnosis with the consequent reduction of the time from the appearance of the ileus to the operation.
Toothbrushes wear out and progressively lose their ability to clean as the bristles abrade and become curled and matted. To study the factors that influence this process, we developed a quantitative measure of bristle splaying (wear index) and a method for judging and ranking the overall state of brush deterioration (wear rating) and used these to determine the effects of the individual user, brush design, time in use, and bristle material. Wear index is the average increase in brush-head dimensions normalized for maximum bristle length, and is dimensionless. Wear rating is a subjective means of classifying the increasing severity of deterioration on a scale of 0 to 3. The wear characteristics of a variety of commercial and experimental brushes with different design features were determined. Test variables were time in use, brush design (e.g., geometry and size of the brush head), and bristle composition. Time of use, the individual user, and bristle composition were found to have the strongest influences on splaying, and brush design was found to have the least influence. The wear index offers a quantitative means of comparing brushes of different dimensions at various stages of splaying. The wear rating, although qualitative, is a quick means of ranking brushes in various stages of deterioration. The two methods correlate (R2 = 0.87), and both are sensitive to several factors that affect brush durability. Therefore, these methods appear to be suitable not only for research, but also for quality control, the setting of standards, and for substantiation of advertising claims.