Knowledge, perception, and clinical experiences on molar incisor hypomineralization amongst Portuguese dentists

Aim

Molar incisor hypomineralization (MIH) is a prevalent oral health condition whose knowledge by dentists is key to the best clinical outcome. This study aimed to evaluate the knowledge, perceptions and clinical experiences of MIH among Portuguese dentists.

Methods

A cross-sectional structured questionnaire was distributed nationally through a web-based survey platform. Data concerning demographic variables, years of experience, dental specialty, MIH prevalence, diagnosis, severity, training demands and clinical management of MIH were collected. We calculated a knowledge score (KS), and compared data between Pediatric Dentists (PDs), General Dental Practitioners (GDPs) and other dental specialties (ODS).

Results

Overall, 2.2% of Portuguese dentists (n = 257) answered the questionnaire. Most participants reported having identified MIH in their practice (82.5%), with PD reporting the prevalence appeared to have increased, and practically all (91.7%) considered it a public health problem. Resin composite was often the used material to restore MIH teeth (56.0%), however PDs indicated glass ionomer cements as the preferred and preformed crowns a better option. The average KS on MIH was 41.3 (± 5.7), with GDPs having a similar score than PDs. Most respondents (94.9%) reported a lack of information about MIH and were willing to receive appropriate clinical training.

Conclusions

The average knowledge on MIH was considered low among Portuguese dentists. Respondents perceived an increased incidence of MIH, despite the lack of prevalence data in Portugal. The material of choice was Glass Ionomer and performed crowns, by PDs, while GDPs and ODS reported poor confidence to manage MIH. These results may serve future programs to increase knowledge, perceptions and clinical experiences towards MIH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02284-1.

Speciation of human microsporidia by polymerase chain reaction single-strand conformation polymorphism

We describe the application of single-strand conformation polymorphism (SSCP) analysis to the speciation of human microsporidia after polymerase chain reaction (PCR) amplification with the panmicrosporidian primers PMP1 and PMP2. We compared the DNA extracted and amplified from different genotypes or isolates of Enterocytozoon bieneusi, Encephalitozoon cuniculi, E. hellem, and E. intestinalis plus an isolate of Vittaforma corneae. The PCR-SSCP, when performed at 20 degrees C, generated 2 bands in distinctive, reproducible patterns in polyacrylamide gels for each species of microsporidia tested, regardless of genotype or isolate. We found PCR-SSCP to be an easy and reproducible method for speciation of human microsporidia when the primer pair PMP1 and PMP2 is used.

Successful weaning from milrinone of a patient with severe congestive heart failure using carvedilol

Congestive heart failure is a major and growing health care concern worldwide, and mortality in patients with severe heart failure is high. Few options are available to patients with New York Heart Association class IV heart failure refractory to oral medical therapy. Over the last 15-20 years milrinone, a phosphodiesterase-III inhibitor, has been used occasionally to treat patients with acute heart failure and as a bridge to heart transplantation and, more recently, has been used intermittently or continuously on an outpatient basis. We report a patient with severe, chronic congestive heart failure, whom we treated successfully with continuous milrinone infusions as an outpatient. We were able to wean him of the milrinone after successful up-titration of carvedilol. Nine months after discontinuation of milrinone the patient remains stable in New York Heart Association class I on high dose carvedilol. Research is required to validate the possibility that patients with severe heart failure may be successfully weaned from milrinone using carvedilol and achieve significant improvement of their functional status and quality of life. This may prove to be an effective strategy for the treatment of selected patients with severe, chronic congestive heart failure. (c)2001 by CHF, Inc.

Difficult cases in heart failure: Effective treatment of severe acute myocarditis with intravenous immune globulin and pulse corticosteroids in a 32-year-old patient

We describe a 32-year-old patient with acute myocarditis resulting in severe heart failure with hemodynamic compromise who improved significantly after treatment with immune globulin and pulse steroids. Six weeks after termination of the immunosuppressive therapy the patient developed symptoms of heart failure again and his ejection fraction decreased to 30%-34%. Treatment with immune globulin resulted in resolution of symptoms and return of left ventricular function. (c)2000 by CHF, Inc.

Limitations on the quantitative determination of telomerase activity by the electrophoretic and ELISA based TRAP assays

Telomerase is a promising new tumor marker and can be detected using the TRAP (Telomeric Repeat Amplification Protocol) method. To address factors affecting its quantitative determination, we evaluated two commercial TRAP assays, an electrophoretic and an ELISA assay formats, using cultured cells and human tumor samples. We found that both TRAP assays had a limited linearity from 250 to 5000 tumor cells, with a similar intra-assay variation. The quantification of TRAP products was affected by high cell number in sample, the presence of non-tumor cells, and interfering substances in patient specimens. Because both assays have different limitations, determination of telomerase by a combined use of the two may provide more accurate information on the telomerase activity in a specimen. Extracts of specimens should also be tested at several concentrations to insure that the result is not being falsely decreased by an inhibitor. The quantitative results for telomerase activity by the TRAP assays, however, should be interpreted cautiously.

Decreased expression of tumor necrosis factor-alpha in failing human myocardium after mechanical circulatory support : A potential mechanism for cardiac recovery

BACKGROUND

An increasing number of observations in patients with end-stage heart failure suggest that chronic ventricular unloading by mechanical circulatory support may lead to recovery of cardiac function. Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine capable of producing pulmonary edema, dilated cardiomyopathy, and death. TNF-alpha is produced in the myocardium in response to volume overload; however, the effects of normalizing ventricular loading conditions on myocardial TNF-alpha expression are not known. We hypothesize that chronic ventricular unloading by the placement of a left ventricular assist device (LVAD) may eliminate the stress responsible for persistent TNF-alpha expression in human failing myocardium.

METHODS AND RESULTS

Myocardial tissue was obtained from normal hearts and from paired samples of 8 patients with nonischemic end-stage cardiomyopathy at the time of LVAD implantation and removal. Tissue sections were stained for TNF-alpha, and quantitative analysis of the stained area was performed. We found that TNF-alpha content decreased significantly after LVAD support. Furthermore, the magnitude of the changes did not correlate with the length of LVAD support, although greater reductions in myocardial TNF-alpha content were found in patients who were successfully weaned off the LVAD who did not require transplantation.

CONCLUSIONS

These data show for the first time that chronic mechanical circulatory assistance decreases TNF-alpha content in failing myocardium; furthermore, we suggest that the magnitude of the change may predict which patients will recover cardiac function.

Telomerase activity in microdissected human gliomas

Future improvements in the diagnosis and treatment of human gliomas might rely on obtaining more specific information concerning the biologic characteristics of individual tumor cells. Telomerase, a ribonucleoprotein that synthesizes telomeres, has been reported to be expressed in a majority of human tumors, including several subtypes of brain tumor. We hypothesized that a quantitative assay for telomerase activity, combined with selective microdissection of tumor or normal brain cells, might reveal telomerase gain-of-function to be important in the pathogenesis of gliomas and that telomerase levels might have prognostic significance. We used tissue microdissection for selective analysis of tumor cells obtained from eight patients with glioma, one with a meningioma, and one with a primary B-cell lymphoma of the central nervous system. Normal brain tissue microdissected from another patient was used as a control. Telomerase activity was screened by an electrophoretic method and then assayed by a quantitative ELISA method. All of the eight gliomas had positive telomerase activity, as did the lymphoma. The meningioma and normal brain were negative. Quantitative analysis of telomerase activity did not correlate with tumor grade nor predict outcome. Selective tissue microdissection, combined with qualitative and quantitative telomerase assays, permits rapid and reliable detection of telomerase activity in diverse brain tumor tissues. These preliminary findings suggest that telomerase reactivation is a frequent event in glioma tumorigenesis that can be sensitively and specifically detected in gliomas of all histologic grades. Furthermore, specific detection of telomerase reactivation represents another mechanism by which tumor formation and progression might become the target of novel therapeutics.

Automated peritoneal dialysis: a Spanish multicentre study

BACKGROUND

A prospective sequential study on continuous ambulatory peritoneal dialysis (CAPD) and three techniques of automated peritoneal dialysis (APD) was conducted to assess peritoneal clearances, the influence of peritoneal permeability on nocturnal APD clearances and the suitability of the peritoneal equilibration test (PET) for predicting clearances on APD.

METHODS

After performing a PET, a series of clinical, biochemical and dialysis adequacy markers were evaluated after 2 months on CAPD, continuous cycling peritoneal dialysis (CCPD) and tidal volume peritoneal dialysis (TPD) with 50% and 25% tidal volumes. Forty five patients participated and 33 completed the study.

RESULTS

Serum urea and creatinine decreased significantly whereas haemoglobin and glucose increased. Mean peritoneal urea clearance (1/week) was 55.40+/-8.76 on CAPD, 74.82+/-12.62 on CCPD, 69.20+/-14.63 on TPD (tidal 50%) and 66.89+/-13.23 on TPD (tidal 25%); mean creatinine clearance (1/week/1.73 m2) was 42.80 +/- 9.95, 52.19 +/- 11.11, 51.31 +/- 13.3 and 49.17 +/- 11.83, respectively. Both clearances were significantly lower on CAPD than on APD (P<0.001). CCPD was the automated technique that provided the best nocturnal urea clearance (P<0.01). Nocturnal creatinine clearance did not show significant differences between CCPD and TPD (tidal 50%), being better with both techniques than with TPD (tidal 25%). There were statistically significant differences between nocturnal dialysate to plasma (D/P) ratios and those corresponding to the nearest times in the PET. The urea D/P ratio at 180 min and the creatinine D/P ratio at 240 min of the PET were the parameters that better estimated nocturnal clearances on APD.

CONCLUSIONS

This study confirms that TPD does not improve the results of CCPD. Significant differences between D/P ratios during actual nocturnal cycles and PETs were observed.

p53 mutations in cyclophosphamide-associated bladder cancer

Cyclophosphamide is a known bladder carcinogen, with cumulative dose directly related to increased risk. There is no consensus, however, on which major cyclophosphamide metabolite (i.e., acrolein or phosphoramide mustard) drives bladder carcinogenesis. We examined 19 cyclophosphamide-related bladder tumors to test the hypothesis that they might contain somatic mutations in the p53 tumor suppressor gene that could link a specific metabolite to the etiology of these cancers. Forty-three % (9 of 19) of the cases had a mutation in p53, with a predominance at G:C bp (7 of 9, 77%), a preference for non-CpG sites (6 of 7, 86%), and frequent G:C-->A:T transitions (5 of 7, 71%). The p53 mutation spectrum of these cyclophosphamide-associated bladder cancers differed significantly from patterns reported for sporadic (P = 0.020), smoking-related (0.043), and schistosomiasis-linked (P = 0.002) tumors but not arylamine-associated neoplasms (P = 0.860). Differences between the cyclophosphamide and arylamine-associated spectra included an unusual degree of clustering of exon 6 mutations (43% versus 17%, respectively) and an absence of multiple mutations in the former. Notably lacking in our series were G:C-->T:A transversions, the principal mutation associated with acrolein. Instead, the mutation spectrum matches the phosphoramide mustard adduction sequences determined by a repetitive primer-extension assay (P = 0.024), indicating that this metabolite might be a key mutagen in cyclophosphamide-related bladder cancer.