Identification and Characterization of an Insulin-Like Receptor Involved in Crustacean Reproduction.

Sexual differentiation and maintenance of masculinity in crustaceans has been suggested as being regulated by a single androgenic gland (AG) insulin-like peptide (IAG). However, downstream elements involved in the signaling cascade remain unknown. Here we identified and characterized a gene encoding an insulin-like receptor in the prawn Macrobrachium rosenbergii (Mr-IR), the first such gene detected in a decapod crustacean. In mining for IRs and other insulin signaling-related genes, we constructed a comprehensive M. rosenbergii transcriptomic library from multiple sources. In parallel we sequenced the complete Mr-IR cDNA, confirmed in the wide transcriptomic library. Mr-IR expression was detected in most tissues in both males and females, including the AG and gonads. To study Mr-IR function, we performed long-term RNA interference (RNAi) silencing in young male prawns. Although having no effect on growth, Mr-IR silencing advanced the appearance of a male-specific secondary trait. The most noted effects of Mr-IR silencing were hypertrophy of the AG and the associated increased production of Mr-IAG, with an unusual abundance of immature sperm cells being seen in the distal sperm duct. A ligand blot assay using de novo recombinant Mr-IAG confirmed the existence of a ligand-receptor interaction. Whereas these results suggest a role for Mr-IR in the regulation of the AG, we did not see any sexual shift after silencing of Mr-IR, as occurred when the ligand-encoding Mr-IAG gene was silenced. This suggests that sexual differentiation in crustaceans involve more than a single Mr-IAG receptor, emphasizing the complexity of sexual differentiation and maintenance.

Cloning of an insulin-like androgenic gland factor (IAG) from the blue crab, Callinectes sapidus: implications for eyestalk regulation of IAG expression.

In malacostracan crustaceans, sex differentiation is uniquely regulated by a hormone secreted by the male-specific androgenic gland (AG). An isopod AG hormone was the first to be structurally elucidated and was found to belong to the insulin superfamily of proteins. Recently, it has been found that the AGs of several decapod crustaceans express insulin-like androgenic gland factors (IAGs), whose function is believed to be similar to that of the isopod AG hormone. Here we report the isolation from the blue crab Callinectes sapidus of the full-length cDNA encoding a candidate insulin-like AG hormone, termed Cas-IAG. The predicted protein Cas-IAG was encoded as a precursor consisting of a signal peptide, the B chain, the C peptide, and the A chain in that order. While the AG was the main source of Cas-IAG expression, as found in other decapod species, the hepatopancreas of male Callinectes sapidus crabs displayed minor Cas-IAG expression. Eyestalk ablation confirmed the presence of a possible endocrine axis between the eyestalk ganglia and the AG, implying that Cas-IAG expression is negatively regulated by (a) substance(s) present in the eyestalk ganglia.

Radiological features of glandular odontogenic cyst.

OBJECTIVES: To present five new cases of glandular odontogenic cyst (GOC) and to review the radiological features at presentation as reported in the English literature. METHODS: From 1993 to 2002, five patients in our department were diagnosed with GOC based on histopathological findings and supported by radiography and CT. The radiographic features of the new GOC cases were analysed in addition to 51 literature cases. RESULTS: There were 31 male and 25 female patients, aged 14-90 years (mean 50 years). The mandible was involved in 80% and the maxilla in 20%; most of the lesions were located in the anterior jaw. Radiographically, 52% of the lesions were unilocular and 48% were multilocular; 94.5% showed well defined borders, which were sclerotic in 7.7% and scalloped in 13%. Information on cortical plate integrity was available in only 24 cases: 50% showed perforation, 8.3% erosion of the cortical plates and 8.3% thinning of the cortical plates. Root resorption was reported in 22% of patients and tooth displacement in 24.4%. CONCLUSIONS: Data collected indicate that GOC has potentially aggressive behaviour, with expansion and perforation in a significant number of cases. We recommend the use of multiple plane radiographs, with CT reserved for large lesions, especially those that are multilocular or involve extragnathic structures.

Intraoral distraction osteogenesis of the mandible in hemifacial microsomia.

PURPOSE: Lengthening of the mandible by distraction osteogenesis is the preferred method for treatment of hemifacial microsomia in children. Use of an intraoral distraction technique and horizontal oblique ramus osteotomy in such patients is presented. PATIENTS AND METHODS: Mandibular ramus lengthening was performed in 11 patients aged 6 to 12 years with hemifacial microsomia. During the age of mixed dentition in hemifacial microsomia patients with a hypoplastic mandible, the unerupted molars buds are located high in the retromolar region and are in danger of being damaged by the osteotomy. Therefore, an intraoral approach exposing the mandibular ramus and angle was performed, and a horizontal oblique ramus osteotomy was made, preserving the inferior alveolar nerve. An intraoral device was placed along the ramus, and distraction was started on the third postoperative day at the rate of 1 mm/d and continued for 2 to 3 weeks or as long as necessary. The device was maintained for retention an additional 6 weeks and was then removed. RESULTS: Clinically, the face became more symmetric. The postdistraction posteroanterior cephalometric radiographs demonstrated elongation of the affected ramus and improvement in facial symmetry. CONCLUSIONS: The advantages of this method are that it allows device placement along the ramus, permitting the ramus elongation necessary in treatment of hemifacial microsomia, that it prevents damage to the tooth buds which, during the age of mixed dentition, are in a higher position in the retromolar area, and that it prevents injury of the inferior alveolar nerve.

Spontaneous regression of optic gliomas: thirteen cases documented by serial neuroimaging.

OBJECTIVE: To demonstrate spontaneous regression of large, clinically symptomatic optic pathway gliomas in patients with and without neurofibromatosis type 1 (NF-1). METHODS: Patient cases were collected through surveys at 2 consecutive annual meetings of the North American Neuro-Ophthalmology Society (NANOS) and through requests on the NANOSNET Internet listserv. Serial documentation of tumor signal and size, using magnetic resonance imaging in 11 patients and computed tomography in 2 patients, was used to evaluate clinically symptomatic optic pathway gliomas. All tumors met radiologic criteria for the diagnosis of glioma and 4 patients had biopsy confirmation of their tumors. In 3 patients, some attempt at therapy had been made many years before regression occurred. In one of these, radiation treatment had been given 19 years before tumor regression, while in another, chemotherapy had been administered 5 years before signal changes in the tumor. In the third patient, minimal surgical debulking was performed 1 year before the tumor began to shrink. RESULTS: Spontaneous tumor shrinkage was noted in 12 patients. Eight patients did not have NF-1. In an additional patient without NF-1, a signal change within the tumor without associated shrinkage was detected. Tumor regression was associated with improvement in visual function in 10 of 13 patients, stability of function in 1, and deterioration in 2. CONCLUSIONS: Large, clinically symptomatic optic gliomas may undergo spontaneous regression. Regression was seen in patients with and without NF-1. Regression may manifest either as an overall shrinkage in tumor size, or as a signal change on magnetic resonance imaging. A variable degree of improvement in visual function may accompany regression. The possibility of spontaneous regression of an optic glioma should be considered in the planning of treatment of patients with these tumors.

Increased endothelial cell expression of alpha3beta1 integrin in cardiac valvulopathy in the primary (Hughes) and secondary antiphospholipid syndrome.

The objective of this work was to determine markers of endothelial cell activation in valves from patients with antiphospholipid syndrome (APS) and heart valve involvement, in order to establish a role for endothelial cells in the pathogenesis of the valvular disease. Sixteen valves from ten patients with APS, obtained from autopsies or removed during valve replacement, were studied. Two groups of valves were used as controls. One group included seven normal valves from patients who died from non-cardiac diseases. The other group of valves were obtained from patients with bacterial endocarditis during autopsies or valve replacement operations. Immunoperoxidase and immunofluorescence stainings with antibodies to human immunoglobulins, endothelial cells, alpha3beta1 integrin, collagen IV, laminin and fibronectin were employed. Three histopathological patterns were apparent: normal valves, valves with verrucous endocarditis and valves with fibrocalcific changes. In all the valves with verrucous endocarditis the following findings were observed: (1) increased expression of the alpha3beta1 integrin on the endothelial cells, (2) increased amount of collagen IV, laminin and fibronectin, (3) proliferation of blood vessels and (4) linear subendothelial deposition of immunoglobulins and complement. The valves with fibrocalcific changes were deformed and showed a thick layer of collagen IV, laminin and fibronectin, yet in two valves the indothelial cells showed an expression of the alpha3beta1 integrin. The control valves did not express the integrin and had only a thin subendothelial band of collagen IV. In valves from patients with APS, 1 markers of endothelial cell activation are upregulated while the inflammatory exudate is scant. There is also a prominent deposition of immunoglobulins in the valves from patients with APS, suggesting a possible association between the deposition of the antibodies and the activation of the endothelial cells in APS.

Uremic optic neuropathy. A uremic manifestation mandating dialysis.

A 41-year-old male patient in end-stage renal failure presented on two occasions, over an 18-month period, with painless unilateral visual deterioration and optic disc edema. Clinical findings were compatible with a diagnosis of uremic optic neuropathy. On his initial presentation, the patient refused the onset of dialysis, resulting in a permanent visual deficit of the left eye. On his subsequent admission with a similar clinical picture, this time of the right eye, dialysis combined with corticosteroid therapy was promptly instituted. This led to a rapid improvement of the visual acuity and visual field defects of the right eye concomitant with subsidence of the edema of the optic nerve head.

Metastatic follicular thyroid carcinoma to the maxilla.

We present a unique case of metastatic follicular thyroid carcinoma to the hard palate and the maxillary sinus, a case that to our knowledge has not been reported before. Various malignant tumours that metastize to the maxilla are reviewed, and the therapeutic approach to follicular thyroid carcinoma metastasis to that area is also discussed. Follicular thyroid carcinoma should be included in the list of tumours that metastasize to the maxilla.

Traumatic bone cyst resembling apical periodontitis.

Among the pseudocysts of the jaws, the traumatic bone cyst is known as an asymptomatic lesion often noted unintentionally during routine radiographic examinations. The lesion neither devitalizes the teeth within its borders, nor does it cause resorption of their roots. The well-demarcated traumatic bone cyst often projects into the intraradicular septa and hence has been described as having scalloped borders. The following presentation is of a traumatic bone cyst that resembled periodontal pathology in its appearance.

Incidence and type of cervical spine injuries associated with mandibular fractures.

The incidence of facial fractures accompanied by spinal injuries, while low, is of significant concern to the craniomaxillofacial surgeon. There are conflicting reports on the association between facial fractures and concomitant spinal damage. This retrospective study of 424 patients with mandibular fractures examines the relationship of mandibular fractures and concomitant spinal injuries. The incidence of concurrent mandibular and cervical fractures was 2.6%, predominantly associated with motor vehicle accidents. The purpose of this study is to examine the incidence of cervical spine injury associated with mandibular fractures, in order to improve the diagnosis and treatment of spinal injury associated with mandibular fractures.

Reading-evoked visual dimming.

PURPOSE: To carry out a neuroradiologic investigation in a monocular 49-year-old patient who during the past five years described symptoms of dimming of central vision in his left eye, which was provoked only by reading. METHODS: Computed tomography and magnetic resonance imaging were performed. RESULTS: An orbital apex intraconal tumor situated laterally to and above the optic nerve was found. CONCLUSIONS: Reading-evoked visual dimming can be a variant of gaze-evoked amaurosis. The optic nerve displaced laterally and superiorly, and stretched by the act of reading, may be compressed between the tumor above and the contracted inferior rectus muscle inferiorly.