Cementoblastoma related to a primary tooth: a case report

Cementoblastomas are benign lesions of the odontogenic ectomesenchyme that rarely occur related to the primary dentition, especially on the left side of the mandible. This study describes a case of a true cementoblastoma related to the left second primary mandibular molar in a 7-year-old child (the largest one seen in the left side of the mandible). Additionally, the radiographic and histologic findings of the lesion are described in details.     

FRACTURE OF ABUTMENT SCREW SUPPORTING A CEMENTED IMPLANT-RETAINED PROSTHESIS WITH EXTERNAL HEXAGON CONNECTION: A CASE REPORT WITH SEM EVALUATION

One of the causes of implant failures in cemented implant-retained prostheses is the fracture of abutment screw or UCLA abutment. This article reports a case of simultaneous fracture of two UCLA abutments screws occurring in an implant-supported prosthesis placed in the mandibular molar region. The fractured structures were examined under scanning electron microscopy to investigate the probable causes of the failure, which were not related to failures on materials or fabrication of the screws, but rather were due to shear forces. The misfit in cemented prostheses may be the most likely cause of shear force generation.     

Epilepsy syndromes associated with hypothalamic hamartomas.

PURPOSE: Hypothalamic hamartoma (HH) related epilepsy presents with gelastic seizures (GS), other seizure types and cognitive deterioration. Although seizure origin in GS has been well established, non-GS are poorly characterized. Their relationship with the HH and cognitive deterioration remains poorly understood. We analyzed seizure type, spread pattern in non-GS and their relationship with the epileptic syndrome in HH. METHODS: We documented all current seizure types in six adult patients with HH-epilepsy with video-EEG monitoring, characterized clinical-electrographic features of gelastic and non-gelastic seizures and correlated these findings with cognitive profile, as well as MRI and ictal SPECT data. RESULTS: Only four seizure types were seen: GS, complex partial (CPS), tonic seizures (TS) and secondarily generalized tonic-clonic seizures (sGTC). An individual patient presented either CPS or TS, but not both. GS progressed to CPS or TS, but not both. Ictal patterns in GS/TS and in GS/CPS overlapped, suggesting ictal spread from the HH to other cortical regions. Ictal SPECT patterns also showed GS/TS overlap. Patients with GS-CPS presented a more benign profile with preserved cognition and clinical-EEG features of temporal lobe epilepsy. Patients with GS-TS had clinical-EEG features of symptomatic generalized epilepsy, including mental deterioration. CONCLUSIONS: Video-EEG and ictal SPECT findings suggest that all seizures in HH-related epilepsy originate in the HH, with two clinical epilepsy syndromes: one resembling temporal lobe epilepsy and a more catastrophic syndrome, with features of a symptomatic generalized epilepsy. The epilepsy syndrome may be determined by HH size or by seizure spread pattern.     

The 12‐Lead ECG in Patients with Mahaim Fibers

The aim of this review article is to discuss the electrocardiographic presentation of the so called variants of pre‐excitation (“Mahaim fibers”) during sinus rhythm and tachycardia.     

Propene polymerization with δ-TiCl3/AlCl(C2H5)2 and δ-TiCl3/Al(C2H5)3 catalyst systems, 1. Effect of external donors

The effect of ethyl benzoate (EB), diisobutyl phthalate (DIBP), dibutyl ether (DBE) and triethoxy(phenyl)silane (EPS) as third components on the propene polymerization with the catalyst systems δ-TiCl₃/AlCl(C₂H₅)₂ and δ-TiCl₃/Al(C₂H₅)₃ was investigated. The influence of external donors on the isotacticity, catalyst activity and average molecular weight (M _v) was tested. If external donors are employed, M _v decreases, the insoluble fraction in boiling isooctane increases and the catalyst activity is strongly influenced by the mole ratio external donor/TiCl₃. The results indicate that all external donors employed have the same qualitative effect on catalytic active centers.     

The Organization of the Venous Spaces of the Cavernous Sinus

The study of the venous channels in the cavernous sinus in 48 sphenoid bones was performed. Thirty-eight bones were electrolyticly decalcified, subsequently embedded in gelatin, and cut in 1 mm thick slices. Microdissection of the other ten specimens complemented the analysis. Every specimen had the venous structure arranged as a plexus, however, although the channels were variable in number, form, and diameter, the two sides were quite symmetrical. Channels of smaller diameter predominated anteriorly. There was no demonstrable muscular layer in these vessels; the endothelial lining was easily visualized. Fatty tissue separated the venous channels from each other and from arteries and nerves. The distance from the carotid artery and the lateral wall increased anteriorly, but there were significant veins between these two structures in only 35% of the cases. In about one third of specimens the oculomotor nerve was placed over the carotid artery. The abducens nerve was found to be intimately related to the lateral wall without any venous channels between them in 92% of the specimens.     

Neuronal activity in the globus pallidus of multiple system atrophy patients.

The pathophysiological changes in neural activity that characterize multiple system atrophy (MSA) are largely unknown. We recorded the activity of pallidal neurons in 3 patients with clinical and radiological features of MSA who underwent unilateral microelectrode-guided pallidotomy for disabling parkinsonism. Findings in these patients were compared with 4 control patients with a clinical diagnosis of Parkinson's disease (PD). The position, firing rates, and firing patterns of single neurons in the pallidal complex were analyzed in both MSA and PD patients. The mean spontaneous firing rate of neurons in the internal segment of the globus pallidus internus (GPii) was significantly lower in MSA than in PD patients. There were no significant differences between MSA and PD patients, however, in firing rates of neurons in the external globus pallidus (GPe) or in the external segment of GPi (GPie). In addition, no significant differences in firing pattern were found between MSA and PD patients. In conclusion, this study has shown that firing rates of neurons in GPii but not in GPie and GPe are different in MSA patients compared with that in PD patients, a finding that may reflect the poor clinical results of pallidotomy reported in patients with MSA.     

Cystic spinal dysraphism of the cervical and upper thoracic region

Background Cystic dysraphic lesions of the cervical and upper thoracic region are rare and only a few series have been published about the topic. These malformations can be divided into categories that include both myelocystoceles and the so-called cervical meningoceles or myelomeningoceles.Methods A retrospective study of 18 patients was conducted.Results In 17 patients a squamous or a cicatricial epithelium of variable thickness covered the dome of the lesions, while the base was covered with full-thickness skin. In one case the skin was entirely normal. Four patients displayed associated CNS malformations and three more had systemic congenital anomalies. All patients underwent surgical exploration and the length of time between birth and surgery ranged from 6 h to 9 months. The most frequent surgical finding, seen in 14 patients, was a stalk connecting the dorsal surface of the spinal cord to the cyst. In three patients the findings were consistent with myelocystocele. Only in one case was a true meningocele found. Hydrocephalus and Chiari II malformation were not as consistently associated as in myelomeningoceles. Neurological signs and symptoms were not so marked as in myelomeningoceles and were found in the follow-up of four patients. In two of them there was a non-progressive deficit, probably expressing an imperceptible involvement of the nervous system in the first year of life. The histopathological findings were of three types: neuroglial stalks, fibrovascular stalks and myelocystoceles.Conclusions Cystic dysraphisms of the cervical and upper thoracic region differ clinically and structurally from meningomyelocele and have a more favorable outcome. We believe that these malformations have not been properly labeled and propose a classification based on the structures found inside the cyst.     

Ki-1 Large Cell Lymphoma with Regressing Lesions in a Child

An 8-year-old boy was seen with a cutaneous Ki-1 anaplastic, large cell lymphoma with multiple lesions. Some of the lesions showed spontaneous regression. During more than seven years of disease no systemic involvement was observed, but recurrent, self-healing lesions did appear. Histopathologic examination of five lesions revealed a variety of findings, from an inflammatory infiltrate to a highly anaplastic pattern. The neoplastic cells expressed Ki-1 and leukocyte common antigens. Ultrastructurally, those cells showed ruffled indentations. The differential diagnosis includes microvillous malignant lymphoma. The patient has had a four-year follow-up without relapses.     

Insulin resistance is associated with circulating fibrinogen levels in nondiabetic patients receiving peritoneal dialysis.

BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting.