Othonella araguaiana (Bivalvia, Megadesmidae) from the Corumbatai Formation (Midlle [Middle] Permian), Eastern Margin of the Parana Basin: systematic, evolutionary and biostratigraphic significances.

In this study, the occurrence of Othonella araguaiana Mendes, a rare bivalve species is reported for the first time in the Pinzonella illusa biozone, Middle Permian Corumbatai Formation, in the State of São Paulo. This species was originally described in coeval rocks of the Estrada Nova Formation (= Corumbatai) from the Alto Araguaia and Alto Garcas regions, State of Mato Grosso. The specimens of O. araguaiana were found in the base of a bioclastic sandstone bed, a proximal tempestite, in the middle of the Corumbatai Formation, in the city of Rio Claro, São Paulo State. The silicified shells and internal molds are well preserved, showing impressions of muscle scars and other internal anatomic characters (e.g., hinge), never illustrated by previous authors. In his original description, Mendes (1963) called attention to the similarity between O. araguaiana and Terraia aequilateralis, a common veneroid of the Corumbatai Formation. Conversely, Runnegar and Newell (1971) suggested that O. araguaiana belongs to Megadesmidae, being a junior synonym of Plesiocyprinella carinata (the commonest megadesmid of the Passa Dois Group). Our study indicates that O. araguaiana is indeed a megadesmid, but is distinct from the P. carinata. The new occurrence of O. araguaiana demonstrates that a) the paleobiogeographic distribution of this species is wider than previously thought (that it was restricted to the northern part of Parana Basin, Mato Grosso State); b) the molluscan fauna of the Corumbatai Formation (P. illusa biozone) in the State of São Paulo is more diverse and dominated by megadesmids; and c) the composition of the molluscan fauna of the Corumbatai Formation in Alto GarYas, State of Mato Grosso, is essentially the same as that of the P. illusa biozone of the eastern margin of the Parana Basin.

Midsymphyseal distraction osteogenesis: A new alternative for the treatment of dental crowding

In this article, we describe a midsymphyseal distraction osteogenesis treatment with a novel dentally supported appliance. This approach differs from that used in previous reports because the incisors were allowed to move during the distraction procedure. This report shows that midsymphyseal distraction osteogenesis can be used to expand both arches to produce a wider smile. Borderline cases can be treated with this technique without the compromising effects commonly observed with conventional therapy. (Am J Orthod Dentofacial Orthop 2009;135:530-5)

Tensile strength and histological changes of abdominal aorta of malnourished rats

The resistance of the abdominal aorta of rats after 6, 7 and 8 weeks of malnutrition, compared with control animals, was evaluated by longitudinal tensiometry. Weakness of this vessel in malnourished rats was demonstrated; microscopic examination of the aorta stained by Masson, Calleja and hematoxylin-eosin methods showed a decrease in amorphous ground substance and an increase in the width of elastic laminae. There was no visible alteration either in the endothelial lining layer or in the smooth muscle fibers. Such alterations of the aorta are, to the authors' knowledge, the first reported modifications in the peripheral vasculature after malnutrition.

Dilatacao pneumatica no megaesofago avancado. Resultados do sequimento tardio

Six patients with advanced Chagas' megaesophagus with poor condition for surgical indication due to severe malnutrition and concomitant diseases were submitted to pneumatic dilatation with the aid of the endoscope. The method consists in leading the tip of the pneumatic dilatator into the cardia with the tip of the endoscope. Insufflation of the balloon must be slow and progressive with visualization of the mucosa of the cardia after insufflating of 2 pounds of air pressure. An excellent symptomatic relief was seen in the five-year follow-up but without improvement in the degree of the esophageal dilatation.

Effects of cervical headgear and edgewise appliances on growing patients

Maxillary basal bone, dentoalveolar, and dental changes in Class II Division 1 patients treated to normal occlusion by using cervical headgear and edgewise appliances were retrospectively evaluated. A sample of 45 treated patients was compared with a group of 30 untreated patients. Subjects were drawn from the Department of Orthodontics, Araraquara School of Dentistry, Brazil, and ranged in age from 7.5 to 13.5 years. The groups were matched based on age, gender, and malocclusion. Roughly 87% of the treated group had a mesocephalic or brachicephalic pattern, and 13% had a dolicocephalic pattern. Cervical headgear was used until a Class I dental relationship was achieved. Our results demonstrated that the malocclusions were probably corrected by maintaining the maxillary first molars in position during maxillary growth. Maxillary basal bone changes (excluding dentoalveolar changes) did not differ significantly between the treated and the untreated groups. Molar extrusion after the use of cervical headgear was not supported by our data, and this must be considered in the treatment plan of patients who present similar facial types. (Am J Orthod Dentofacial Orthop 2001;119:531-9).

Diagnosis of 5α-reductase type 2 deficiency: Contribution of anti-Müllerian hormone evaluation

Aim: To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5α-reductase 2 deficiency. Patients and methods: Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls. Results: Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage. Conclusions: Prepubertal patients with 5α-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells. © Freund Publishing House Ltd., London.

Immunohistochemistry as a fundamental tool for the differential diagnosis of polymorphous low-grade adenocarcinoma

Polymorphous low-grade adenocarcinoma (PLGA) is a subtype of salivary gland carcinoma with a marked predilection for the minor salivary glands. The diagnosis of this lesion can be a challenge in incisional biopsies because of its similarity to other salivary neoplasms and the difficulty of analyzing its infiltrative nature and neurotropism. Diagnosis can be facilitated, however, by immunohistochemistry, a technique that has become a fundamental tool to the pathologist. The purpose of this study was analyze the immunohistochemical aspects of 4 cases that were examined in the São José dos Campos School of Dentistry. The patients included 4 women, ages 32 to 57 years (mean, 50 years), who reported an intraoral painless lesion, ranging in size from 1 to 3 cm (mean, 1.75 cm) with a variable evolution period. Histologically, the lesions showed similar aspects, characterized by polymorphous growth pattern, including solid, cribriform, trabecular, papillary, and single-file arrays. The tumors showed positivity to cytokeratins (Cks) 7 and 8 and vimentin, variable expression for Ck 14, and a negative reaction to Cks 13 and 19 and muscle-specific actin. PLGA is a tumor of the salivary gland that must be distinguished from other neoplasms for therapeutic and prognostic considerations, and the panel of antibodies employed in this study was effective for its diagnosis.

Stacking faults in SiCf/SiC composite obtained by chemical vapor reaction process

SiC fiber-reinforced SiC matrix composite (SiCf/SiC) is one of the leading candidates in ceramic materials for engineering applications due to its unique combination of properties such as high thermal conductivity, high resistance to corrosion and working conditions. Fiber-reinforced composites are materials which exhibit a significant improvement in properties like ductility in comparison to the monolithic SiC ceramic. The SiCf/SiC composite was obtained from a C/C composite precursor using convertion reaction under high temperature and controlled atmosphere. In this work, SiC phase presented the stacking faults in the structure, being not possible to calculate the unit cell size, symmetry and bond lengths but it seem equal card number 29-1129 of JCPDS.

Congenital ranula: A case report

The purpose of this study was to report a case of bilateral swelling on the floor of the mouth of a 7-month-old patient. The lesion was congenital and had started to cause feeding problems. After the clinical diagnosis of ranula was made, the lesion was marsupialized. The obtained specimen was submitted for histopathological examination, which revealed an epithelial-lined cystic lesion. These results led to the final diagnosis of mucus retention cyst. After an 8-year follow-up period, the patient is in good general health with no recurrences.

A new permian bivalve (Megadesmidae, Plesiocyprinellinae) from the Serrinha member, Rio do Rasto Formation, Paraná Basin, Brazil

During a recent inspection in the Paleontological Collection of the Institute of Geosciences, University of São Paulo, we have identifi ed some specimens of undescribed mollusk bivalves. These called our attention for the following reasons: a) all specimens are internal molds of conjugated and closed articulated valves, some of them presenting fragments of silicifi ed shells; b) all internal molds have similar general shape and internal characters, representing specimens of the same taxon; c) the internal molds and silicifi ed valves are well preserved, including fragile structures, which are hardly preserved, such as the internal mold of the external ligament and muscle scars; d) and equally important, according to the labels of all specimens, they were collected from rocks of the Passa Dois Group (Permian), Serrinha Member of the Rio do Rasto Formation. Although who collected the shells and the precise geographic location of the specimens are still unknown, the detailed study of these fossils brings us to the conclusion that they are morphologically distinct from any heretofore published genus of the endemic fauna of bivalves from Passa Dois Group. Based in its general shape, hinge structure and muscles scars, the new form can be classifi ed under the Family Megadesmidae Vokes, 1967, the most diverse group of Permian bivalves of the Paraná Basin. The specimens are referred as Beurlenella elongatella new gen. and sp. The shell shape and taphonomy indicate that this bivalve was a shallow, rapid, active burrower, suspension feeder, probably preserved in situ, in event deposits.

Othonella araguaiana (Bivalvia, Megadesmidae) from the Corumbataí formation (Midlle Permian), eastern margin of the Paraná Basin: Systematic, evolutionary and biostratigraphic significances

In this study, the occurrence of Othonella araguaiana Mendes, a rare bivalve species is reported for the fi rst time in the Pinzonella illusa biozone, Middle Permian Corumbataí Formation, in the State of São Paulo. This species was originally described in coeval rocks of the Estrada Nova Formation (= Corumbataí) from the Alto Araguaia and Alto Garças regions, State of Mato Grosso. The specimens of O. araguaiana were found in the base of a bioclastic sandstone bed, a proximal tempestite, in the middle of the Corumbataí Formation, in the city of Rio Claro, São Paulo State. The silicifi ed shells and internal molds are well preserved, showing impressions of muscle scars and other internal anatomic characters (e.g., hinge), never illustrated by previous authors. In his original description, Mendes (1963) called attention to the similarity between O. araguaiana and Terraia aequilateralis, a common veneroid of the Corumbataí Formation. Conversely, Runnegar and Newell (1971) suggested that O. araguaiana belongs to Megadesmidae, being a junior synonym of Plesiocyprinella carinata (the commonest megadesmid of the Passa Dois Group). Our study indicates that O. araguaiana is indeed a megadesmid, but is distinct from the P. carinata. The new occurrence of O. araguaiana demonstrates that a) the paleobiogeographic distribution of this species is wider than previously thought (that it was restricted to the northern part of Paraná Basin, Mato Grosso State); b) the molluscan fauna of the Corumbataí Formation (P. illusa biozone) in the State of São Paulo is more diverse and dominated by megadesmids; and c) the composition of the molluscan fauna of the Corumbataí Formation in Alto Garças, State of Mato Grosso, is essentially the same as that of the P. illusa biozone of the eastern margin of the Paraná Basin.