Computed tomography of the parathyroids: the value of density measurements to distinguish between parathyroid adenomas of the lymph nodes and the thyroid parenchyma

PURPOSE

To compare the densities of parathyroid adenomas, lymph nodes and the thyroid parenchyma during multi-phase cervico-thoracic computed tomography to determine the differentiating threshold values.

MATERIALS AND METHODS

This study comprises 30 patients operated for a parathyroid adenoma after computed tomography without injection and then 45 and 70 seconds after the injection of an iodine based contrast product (350 mgI/mL, 150 mL, 3 mL/s). The density of the adenomas, lymph nodes and thyroid was measured during the three phases (D0, D45, D70). The relative enhancement (RE) at 45 seconds was calculated: RE=(D45-D0)/D0.

RESULTS

A significant difference was found in the spontaneous density of the parathyroid adenomas of the thyroid (P<0.01) with a threshold value of 75 HU. A significant difference is found in the enhancement after injection of the adenomas and lymph nodes (P<0.01). The adenomas present an enhancement peak at 45 seconds while the maximum enhancement of the lymph nodes is at 70 seconds. At 45 seconds, a threshold value of 114 HU and an RE 125% allows them to be distinguished (sensitivity and specificity 0.96).

CONCLUSION

Measurement of the densities can differentiate between the parathyroid adenomas, lymph nodes and thyroid.

[Cancer, fertility preservation and gonadotropins]

The recent emergence of oncofertility raises the question of ovarian stimulation and its risks when performed for oocyte or/and embryo cryopreservation in a fertility preservation program. The relation between ovarian stimulation and cancer has been marked by the possible direct or indirect tumorigenic role for pituitary gonadotrophins in the tumorogenesis. Although the growth of many gonadal and extragonadal tumors is stimulated by gonadal sex hormones, whose production is regulated by gonadotrophins, there is still a lack of data to consider FSH and LH as tumor promoters. The purpose of this brief review is to present on one hand, the questions raised by the administration of exogenous gonadotrophins in cancer patients and on the other, to evaluate both experimental and clinical data about the possible relation between gonadotrophins and tumorogenesis.

[Characteristics of human immunodeficiency virus-1 infected children receiving highly active antiretroviral therapy: a cross-sectional study]

INTRODUCTION

Since 1996, when HAART became available, there has been a change in the course of HIV-infection, leading it to become a chronic disease. Our aim was to describe the characteristics of the children followed up in our hospital.

PATIENTS AND METHODS

A cross-sectional study was conducted on 32 HIV-infected children followed up until December-2010, at the University-Hospital de Getafe. Clinical and laboratory information from the last visit was collected for the evaluation of patients.

RESULTS

Thirty-two children with HIV-1 were evaluated, 29 infected through vertical-transmission. The median age was 14 years. According to the CDC classification, 56% (18/32) of children were in category A, 28% (9/32) B and 16% (5/32) C. Immunological class was 3 in 75% of children, class 2 in 9% and class 1 in 16%. The median nadir of CD4 was 337 cells/ml (12%). The median current CD4 was 749 (31%). Only one adolescent had a CD4% below 200 cells/ml due to lack of adherence. Twenty-eight patients (87%) were receiving HAART, and 4 patients were off antiretroviral treatment. Among the patients treated, 26 (93%) had viral loads <200 copies/ml. The median viral-load was<20 copies/ml. Median time on antiretroviral treatment was 10 years. The combination more frequently used was two nucleoside reverse transcriptase inhibitors (NRTI) and one protease inhibitor (PI), that was given to 15 patients (47%), followed by 2 NRTI, and one non-nucleoside reverse transcriptase inhibitor (NNRTI) in 8 patients (29%). Two children received rescue therapy including raltegravir, one with tipranavir and the other with darunavir. A total of 12 patients (43%) received medication once a day, 7 of them with fixed-dose combinations in a single tablet (25%). There were metabolic complications, including hyperlipidaemia or lipodystrophy were observed in 17 children (53%).

CONCLUSIONS

Most of our patients are receiving HAART, with good virological and immunological control. The prevalence of metabolic abnormalities was high. Strategies to improve adherence and decrease toxicities are needed in perinatally-acquired HIV-infected children.

Zinc reduces collagen degradation in demineralized human dentin explants

OBJECTIVES

Dentin matrix metalloproteinases are implicated in the pathogenesis of caries and contribute to collagen degradation in resin-dentin interfaces. The objective was to determine if collagen degradation may be modulated by an excess of zinc or zinc chelators.

METHODS

Mineralized and phosphoric acid demineralized human dentin specimens were tested. Chlorhexidine digluconate, doxycycline or ZnCl₂ were added to the media. In half of the groups, active exogenous metalloproteinase-2 was incorporated into the solution. C-terminal telopeptide determinations (radioimmunoassay) were performed after 24 h, 1 and 3 weeks.

RESULTS

Collagen degradation was prominent in demineralized dentin. Doxycycline fully blocked dentin proteolysis. Chlorhexidine digluconate reduced the degradation at the 24-h period. Zinc in excess strongly inhibits hydrolysis of collagen and its effect was maintained for 3 weeks.

CONCLUSIONS

Zinc in excess reduces MMP-mediated collagen degradation. The hypothesis that binding of zinc to collagen results in protection of sensitive cleavage sites of metalloproteinases requires further validation.

Ethanol wet-bonding technique sensitivity assessed by AFM

In ethanol wet bonding, water is replaced by ethanol to maintain dehydrated collagen matrices in an extended state to facilitate resin infiltration. Since short ethanol dehydration protocols may be ineffective, this study tested the null hypothesis that there are no differences in ethanol dehydration protocols for maintaining the surface roughness, fibril diameter, and interfibrillar spaces of acid-etched dentin. Polished human dentin surfaces were etched with phosphoric acid and water-rinsed. Tested protocols were: (1) water-rinse (control); (2) 100% ethanol-rinse (1-min); (3) 100% ethanol-rinse (5-min); and (4) progressive ethanol replacement (50-100%). Surface roughness, fibril diameter, and interfibrillar spaces were determined with atomic force microscopy and analyzed by one-way analysis of variance and the Student-Newman-Keuls test (α = 0.05). Dentin roughness and fibril diameter significantly decreased when 100% ethanol (1-5 min) was used for rinsing (p < 0.001). Absolute ethanol produced collapse and shrinkage of collagen fibrils. Ascending ethanol concentrations did not collapse the matrix and shrank the fibrils less than absolute ethanol-rinses.

Bond strength and nanoroughness assessment on human pretreated cementum surfaces

OBJECTIVES

To determine the bond strength of seven adhesive systems to human cementum, and to assess the promoted surface roughness.

METHODS

Extracted human canines were used for the present study. The mesial surface from the cervical third of the roots were ground flat with wet 600-grit silicon carbide paper and bonded. Seven adhesive systems were employed: an etch-and-rinse adhesive (Single Bond), two two-step self-etching (Clearfil SE Bond and Resulcin Aquaprime) and four one-step self-etching (One-up Bond F, Prompt-L-Pop, Etch and Prime 3.0 and NRC+Prime&Bond NT). Composite build-ups were constructed and stored in a humid environment for 24h at 37 degrees C. Specimens were sectioned into 1mm(2) beams and tested for microtensile bond strength (MTBS). Additional surfaces were conditioned for atomic force microscopy (AFM) analysis. Results were analyzed with ANOVA and Student-Newman-Keuls tests (P<0.05).

RESULTS

Single Bond showed the highest MTBS values. No differences were found between Resulcin Aquaprime, One-up Bond and Prompt-L-Pop. Clearfil SE Bond, Etch and Prime and NRC+Prime&Bond NT obtained the lowest bond strength values. H(3)PO(4) acid treatment of cementum and Resulcin Aquaprime showed the highest nanoroughness parameters and One-up Bond the lowest.

CONCLUSION

The etch-and-rinse adhesive and the two-step self-etching adhesive with the lowest pH value promoted the highest bond strength to human cementum surfaces.

Effect of Double Layering and Prolonged Application Time on MTBS of Water/Ethanol-based Self-etch Adhesives to Dentin

Problems related to the chemical formulation and/or chemical dispersion of hydrophilic/hydrophobic components in one-step self-etch adhesives limit their efficacy and are not easily solved by changing the different bonding application parameters.