Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT

Objective.

The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic gutta-percha. Furthermore, the obturation time for the two techniques was evaluated.

Materials and methods.

Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross-section images from Micro-computed Tomography scans.

Results.

All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between the two techniques was found (p < 0.001).

Conclusion.

The present study found no statistically significant difference in percentage of voids between two root filling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT.

A case of resistance to thyroid hormone without mutation in the thyroid hormone receptor beta

BACKGROUND

Resistance to Thyroid Hormone (RTH) is a condition caused by tissue hyposensitivity to the effects of circulating thyroid hormone, and may be misdiagnosed as hyperthyroidism.

AIMS

We report the first case of RTH in an Irish patient highlighting the clinical features and the pathophysiological mechanism underlying the characteristic laboratory abnormalities found in the condition.

METHODS

We describe an isolated case of RTH initially misdiagnosed as hyperthyroidism, and detail the investigations which ultimately led to the correct diagnosis. Genetic screening of the thyroid hormone receptor beta gene was performed.

RESULTS

Thyroid function tests including T3 suppression test and TRH-stimulation test suggested a diagnosis of RTH. Genetic testing failed to demonstrate a mutation in the thyroid hormone receptor.

CONCLUSION

RTH is a rare inherited condition that may be misdiagnosed as hyperthyroidism. The case we describe most likely results from a de novo mutation in an as yet undiscovered gene. RTH should be considered in patients with elevated thyroid hormone levels and normal TSH so that unnecessary and potentially harmful treatment can be avoided.

Survey on porcine trichinellosis in Ecuador

A survey on porcine trichinellosis was organised in Ecuador between 2000 and 2003. Blood samples were taken in slaughterhouses (study 1, n=2000; study 2, n=331) and in a remote village where pigs are free roaming (study 3, n=646) and examined by ELISA using excretory/secretory (E/S) antigens. Seven samples (0.35%) in study 1 and none of the samples of study 2 were serologically positive. Thirty-seven (5.72%) village pigs tested positive by E/S ELISA in study 3. Sero-positive results by the E/S ELISA in study 1 were confirmed by ELISA using beta-tyvelose antigen, and by immunoblot. Muscle samples taken from pigs slaughtered in the abattoir (study 2) and from animals that showed a positive serology in study 3 were examined by trichinoscopy and artificial digestion. These techniques failed to demonstrate the presence of muscle larvae. The results of this survey need confirmation, but suggest that Trichinella is present in Ecuador; however, prevalence and parasite burdens are likely to be very low. The likelihood of detecting trichinellosis are higher in traditional settings than in pigs raised on improved farms.

Role of conventional ultrasound and color Doppler sonography in the diagnosis of medullary thyroid carcinoma

Early diagnosis of medullary thyroid carcinoma (MTC) can improve long-term prognosis. MTC can be detected at an early stage by calcitonin screening in all patients with thyroid nodules. This approach, however, is controversial due to high costs and a limited specificity of calcitonin. It was the aim of the present study to investigate whether ultrasonography may contribute to the diagnosis of MTC in patients with thyroid nodules. The study included 19 patients with newly diagnosed MTC. Ten patients had sporadic MTC, 7 had multiple endocrine neoplasia (MEN) type 2A, and 2 patients had MEN 2B. In all subjects conventional ultrasound, and in 14 patients color Doppler sonography were performed before primary surgery. For comparison, ultrasound appearance of 139 benign thyroid nodules was evaluated. In conventional ultrasound, MTC in 17/19 (89%) patients were hypoechoic, contained intranodular calcifications, and had no "halo sign". The combination of these criteria were found in only 8/139 (6%) of benign thyroid nodules. Intranodular blood flow was found in 11/14 patients with MTC (79%), perinodular blood flow in 7/14 MTC (50%). In conclusion, conventional ultrasound reveals a combination of hypoechogenicity, intranodular calcifications, and absence of "halo sign" in the vast majority of MTC. Since this sonographic pattern only rarely occurs in benign thyroid nodules, the results indicate that thyroid ultrasound can contribute to the diagnosis of MTC. In addition, the findings may have implications for calcitonin screening in nodular thyroid disease.

Immunogenicity, safety and lot consistency in adults of a chromatographically purified Vero-cell rabies vaccine: a randomized, double-blind trial with human diploid cell rabies vaccine

The immunogenicity and safety of a chromatographically purified rabies vaccine (CPRV) was evaluated using US veterinary medical students. In the first study, 242 healthy adults were enrolled in a randomized, modified double-blind, multicenter trial and received five doses of either CPRV or human diploid cell vaccine (HDCV) by intramuscular injection on days 0, 3, 7, 14, and 28 concurrently with human rabies immunoglobulin in a simulated post-exposure prophylaxis regimen. Post-immunization titers in the CPRV and HDCV groups reached 0.5 IU/ml (the WHO-recommended minimally acceptable titer) or greater in all subjects in both vaccine groups by day 14 and remained above that level through day 90. In the second study, 438 healthy adults were enrolled in a randomized, double-blind, multicenter trial and assigned to receive five doses from one of three lots of CPRV by intramuscular injection on days 0, 3, 7, 14, and 28 in a simulated post-exposure prophylaxis regimen to evaluate lot consistency. Post-immunization titers rapidly increased to over 0.5 IU/ml by day 14 for all subjects and remained above that level through day 42 when the study was terminated. The three lots were considered equivalent. The percentage of subjects with at least one local reaction during the five-dose regimen was slightly lower in the CPRV group than in the HDCV group (P=0.06). The most frequently reported local reaction for all doses of vaccine was pain at the injection site. Headache, myalgia, and malaise were the most frequently reported systemic events. The percentage of subjects with at least one systemic event was significantly lower for CPRV (P=0.0084). No vaccine-related serious adverse reaction was reported in these studies. The results of these studies indicate that CPRV administered intramuscularly to healthy adults is immunogenic and is associated with fewer local and systemic reactions than HDCV.

[Headache in patients with pheochromocytoma. Influence of arterial hypertension]

Headache is an important diagnostic element in pheochromocytoma and it may characterize a body reaction to pathological hormonal oscillations. We observed the pheochromocytoma instability in 20 patients during arterial hypertension and tried to correlate with headache. We found that isolate hypertension is not the only factor in headache pathogenesis. It is possible that changes in catecholamines, adrenomedullin and other neuropeptides may cause some of these symptoms.