251 research outputs found
Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception
Thickness perception of starch-thickened products
during eating has been linked to starch viscosity and
salivary amylase activity. Calcium is an essential cofactor
for α-amylase and there is anecdotal evidence that adding
extra calcium affects amylase activity in processes like
mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase
activity and (2) to measure the effect of calcium concentration on apparent viscosity and thickness perception when interacting with salivary α-amylase in starch-based samples.
α-Amylase activity in saliva samples from 28 people
was assessed using a typical starch pasting cycle (up to 95 °C). The activity of the enzyme (as measured by the change in starch apparent viscosity) was maintained by the presence of calcium, probably by protecting the enzyme from heat denaturation. Enhancement of α-amylase activity by calcium at 37 °C was also observed although to a smaller extent. Sensory analysis showed a general trend of decreased
thickness perception in the presence of calcium, but the result was only significant for one pair of samples, suggesting a limited impact of calcium enhanced enzyme activity on perceived thickness
Ultrasonography of salivary glands in primary Sjögren's syndrome: A comparison with contrast sialography and scintigraphy
Objective. To compare ultrasonography (US) of salivary glands with contrast sialography and scintigraphy, in order to evaluate the diagnostic value of this method in primary SS (pSS). Methods. The diagnostic value of parotid gland US was studied in 77 patients with pSS (male/female ratio 3/74; mean age 54 yrs) and in 79 with sicca symptoms but without SS. The two groups were matched for sex and age. Imaging findings of US were graded using an ultrasonographic score ranging from 0 to 16, which was obtained by the sum of the scores for each parotid and submandibular gland. The sialographic and scintigraphic patterns were classified in four different stages. The area under receiver operating characteristic curve (AUC-ROC) was employed to evaluate the screening methods performance. Results. Of the 77 patients with pSS, 66 had abnormal US findings. Mean US score in pSS patients was 9.0 (range from 3 to 16). Subjects without confirmed pSS had the mean US score 3.9 (range from 0 to 9) (P < 0.0001). Results of sialography showed that 59 pSS patients had abnormal findings at Stage 1 (n = 4), Stage 2 (n = 8), Stage 3 (n = 33) or Stage 4 (n = 14), and 58 patients had abnormal scintigraphic findings at Stage 1 (n = 11), Stage 2 (n = 18), Stage 3 (n = 25) or Stage 4 (n = 4). Through ROC curves US arose as the best performer (AUC = 0.863 +/- 0.030), followed by sialography (AUC = 0.804 +/- 0.035) and by salivary gland scintigraphy (AUC = 0.783 +/- 0.037). The difference between AUC-ROC curve of salivary gland US and scintigraphy was significant (P = 0.034). Setting the cut-off score 6 US resulted in the best ratio of sensitivity (75.3%) to specificity (83.5%), with a likelihood ratio of 4.58. If a threshold 8.0 was applied the test gained specificity, at the cost of a serious loss of sensitivity (sensitivity 54.5%, specificity 97.5%, likelihood ratio 21.5). Conclusions. Salivary gland US is a useful method in visualizing glandular structural changes in patients suspected of having pSS and it may represent a good option as a first-line imaging tool in the diagnostics of the disease
Ultrasonography of salivary glands in primary Sjögren's syndrome: A comparison with contrast sialography and scintigraphy
Salivary flow rate, pH, and concentrations of calcium, phosphate, and sIgA in Brazilian pregnant and non-pregnant women
BACKGROUND: Studies on salivary variables and pregnancy in Latin America are scarce. This study aimed to compare salivary flow rate, pH, and concentrations of calcium, phosphate, and sIgA of unstimulated whole saliva in pregnant and non-pregnant Brazilians. METHODS: Cross-sectional study. Sample was composed by 22 pregnant and 22 non-pregnant women attending the Obstetrics and Gynecology Clinics, São Lucas Hospital, in Porto Alegre city, South region of Brazil. Unstimulated whole saliva was collected to determine salivary flow rate, pH, and biochemical composition. Data were analyzed by Student t test and ANCOVA (two-tailed α = 0.05). RESULTS: No difference was found for salivary flow rates and concentrations of total calcium and phosphate between pregnant and non-pregnant women (p > 0.05). Pregnant women had lower pH (6.7) than non-pregnant women (7.5) (p < 0.001), but higher sIgA level (118.9 mg/L) than the latter (90.1 mg/L) (p = 0.026). CONCLUSION: Some of the tested variables of unstimulated whole saliva were different between pregnant and non-pregnant Brazilians in this sample. Overall, the values of the tested salivary parameters were within the range of international references of normality
Prenatal dental care: evaluation of professional knowledge of obstetricians and dentists in the cities of Londrina/PR and Bauru/SP, Brazil, 2004
Dentinogenesis imperfecta in Osteogenesis imperfecta type XI in South Africa: a genotypeâphenotype correlation
BACKGROUND: The maxillofacial and dental manifestations of Osteogenesis imperfecta (OI) have significant implications in terms
of management. Although the occurrence of abnormal dentine in some forms of OI is well documented, there is scant information
on the association of abnormal dentine in the Black African persons with phenotypic OI III and genotypic OI XI in South Africa.
METHODS: This was a cross-sectional analytic study. A series of 64 Black South African individuals with a confirmed phenotypic
diagnosis of OI III, ages ranging from 3 months to 29 years, were assessed clinically, radiographically, and at a molecular level.
RESULTS: A total number of 64 saliva samples were analyzed and 3 DNA variations were identified in exon 5 of the FKBP10 gene.
The homozygous mutation, c.[831dupC]; [831dupC], was identified in 23 affected persons who had no clinically obvious features of
DI in their primary and secondary teeth. Radiologically, mild features of DI were evident in 10 persons in whom radiographic images
were obtained and were given a Clinicalâradiological score of 2. A compound heterozygous mutation, c. [831delC]; [831dupC], was
identified in three siblings. An intraoral examination of these affected persons revealed no clinically apparent features of DI in their
primary and secondary teeth. Due to the lack of radiological facilities, the presence or absence of DI could not be confirmed or
negated. A second compound heterozygous mutation, c.[831dupC]; [1400-4C>G], was identified in a female of 29 years belonging
to the Xhosa linguistic group. Her teeth appeared clinically normal but it was not possible to obtain radiographs. In 37 affected
individuals, no disease-causing mutations were identified.
CONCLUSION: Black African individuals in SA with the homozygous mutation in the FKBP10 gene have clinically unaffected teeth
yet exhibited radiographic features of DI to varying degrees. This characterization is suggestive of a relationship between the
genetic abnormality and the clinical manifestations of DI. The authors suggest that this diagnosis must include teeth that are
clinically and/or radiologically aberrant, and should not exclude the presence of other, milder, dentinal aberrations associated with
OI. There was no correlation between severity of OI and DI in this cohort of individuals
Two and three-dimensional computed tomography in the diagnosis of impacted teeth.
Abstract
The paper describes the advantages of two and three-dimensional computed tomography in the diagnosis of impacted teeth. Differential colouring of anatomical structures distinguishes between elements of identical or similar density
Magnetic Resonance applications in dental implantology: technical notes and preliminary results.
Valutazione istologica e clinica di difetti ossei parodontali dopo innesto di idrossiapatite.
SPIRAL CT EVALUATION OF MEDIASTINAL VESSELS: CLINICAL APPLICATION OF POST-PROCESSING TECHNIQUES
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