Specific c-kit mutations in sinonasal natural killer/T-cell lymphoma in China and Japan

Sinonasal lymphoma is one of the constituents of lethal midline granuloma, which is a clinical term for progressive, destructive lesions affecting the midline of the face. The majority of sinonasal lymphomas, especially those showing polymorphous patterns of proliferation and thus termed polymorphic reticulosis, recently were categorized as sinonasal natural killer/T-cell lymphomas. They are more prevalent in Asia than Europe or North America and are associated with EBV infection. Twenty-three cases with sinonasal natural killer/T-cell lymphomas were collected from two high-incidence regions: Beijing, China (14 cases) and Osaka, Japan (9 cases). c-kit mutations were analyzed on paraffin-embedded specimens by PCR-single-strand conformation polymorphism followed by direct sequencing; the c-kit proto-oncogene encodes a receptor of tyrosine kinase, which plays an important role in the regulation of normal and neoplastic hematopoiesis by the interaction with its specific ligand, termed stem cell factor. Twelve single nucleotide substitution mutations were seen in 23 cases. Ten of 14 Chinese cases (71.4%) had mutations at exon 11 or exon 17, whereas only two of nine Japanese cases (22.2%) had mutations, showing a significant difference in frequency between Chinese and Japanese cases. Furthermore, seven of eight mutations (92%) in exon 17 occurred at codon 825 and three of four mutations (75%) in exon 11 occurred at codon 561. Such a specificity has not been reported before, and these results, taken together, suggest that location-specific differences in etiological factors cause specific mutations in c-kit gene.     

Erupted complex odontoma: a case report and literature review

A case involving a 17-year-old girl with a large erupted odontoma associated with a deeply impacted mandibular molar is reported. The molar, which previously had been displaced to the border of the mandible, erupted successfully three years after surgical removal of the odontoma. A review of the literature presents guidelines for treating similar cases.     

Pregnancy and lactation

Pregnancy results in physiologic changes in almost all organ systems in the body mediated mainly by female sex hormones. Physiologic changes of pregnancy influence the dental management of women during pregnancy. Understanding these normal changes is essential for providing quality care for pregnant women. This review article briefly discusses the cardiovascular, respiratory, gastrointestinal, urogenital, endocrine, and oral physiologic changes that occur during normal gestation. A summary of current scientific knowledge of ionizing radiation is presented. Information about the compatibility, complications, and excretion of the common drugs during pregnancy is provided. Drugs and their usage during breast-feeding are also discussed. Guidelines for the management of a pregnant patient in the dental office are summarized.     

Mid-line swelling of the palate

Sarcoidosis is a multi-system, non-caseating granulomatous disease of unknown aetiology that may affect any organ. The oral involvement of sarcoidosis is rare and usually an initial manifestation of the disease. In this case report the authors present a 25-year-old African-American woman with palatal sarcoidosis treated successfully with intra-lesional corticosteroid injections. The oral manifestations of sarcoidosis are relatively uncommon and may be the only manifestation of the disease. Suspected cases of oral sarcoidosis should be biopsied and subsequently referred to a physician to rule out systemic involvement.     

Fetal gastrointestinal motility in a rabbit model of gastroschisis

Purpose

Gastrointestinal (GI) dysmotility occurs frequently in full-term infants with gastroschisis (GS). Although controversial, preterm delivery of infants with GS has been advocated to prevent the development of GI dysmotility, and understanding the etiology of gestational-related bowel injury may lead to prenatal therapies. Using a fetal rabbit model, the authors assessed in vivo and in vitro GI motility in preterm GS fetuses.

Methods

On gestation day 24 (term, 31), surgery was performed in maternal rabbits and GS induced in fetuses, whereas control fetuses underwent sham procedures. On gestation day 29, both groups of fetuses received ultrasound-guided intragastric injection of fluorescein and colored microspheres. Two hours after injection, fetuses were delivered by cesarean section and stomach and small intestine harvested intact. “GI motility” was calculated as the distance traveled by fluorescein divided by total length. In vitro studies of fetal gastric muscle strips contractility responses to bethanechol, a cholinergic agonist, were assessed in an organ bath system. Data were analyzed as paired and unpaired t tests and expressed as means ± SEM.

Results

GS reduced fetal body weight and intestinal length compared with controls (28.4 ± 1.4 v. 33.5 ± 1.5 g, 36.9 ± 1.8 v. 25.9 ± 1.2 cm; P < .05, respectively). Fetuses with GS showed markedly reduced in vivo GI motility (51.4 ± 2.9 v 24.8 ± 2.7%; P < .05) and in vitro gastric contractile tension (769 ± 53 v 396 ± 26 mNcm²; P < .05).

Conclusions

GI exposure to amniotic fluid reduces intestinal motility and gastric contractility functions in the preterm rabbit fetus. The results suggest that GS-associated impairment of GI neuromuscular functions occurs in utero, before term, and may be responsive to manipulation of amniotic fluid content or other therapeutic interventions.     

Production,purification and preliminary X-ray crystallographic studies of adeno-associated virus serotype 4

Adeno-associated virus (AAV) serotypes 1 to 5 are currently under development as clinical gene delivery vectors for the treatment of human diseases. However, the ubiquitous nature of their cell surface receptors, heparin sulfate (AAV2 and 3) and sialic acids (AAV4 and 5), can preclude specific tissue targeting in vivo. Structural studies of AAV4 were initiated to characterize its capsid surface for re-targeting manipulations. Crystals obtained diffracted synchrotron radiation to 3.2 A resolution. The unit cell is body-centered orthorhombic, I222, with a = 339.6, b = 319.2 and c = 285.0 A. The virus particle orientation and position have been determined.     

Development of ovine fetal ileal motility: role of muscarinic receptor subtypes

OBJECTIVE: In the preterm human fetus, immaturity of gastrointestinal (GI) motility contributes to impairment of oral feeding and an increased risk of necrotizing enterocolitis. In view of the limited knowledge of fetal GI motility development, and the primary role of the muscarinic system in adult GI motility, we examined the development of GI muscarinic receptor subtypes associated with ileal motility. STUDY DESIGN: Ovine term fetal, newborn, and pregnant adult ileal longitudinal muscle contractile responses to muscarinic agonists (bethanechol) and muscarinic nonspecific (atropine) and subtype specific-antagonists (M1-M4) were examined in organ baths. Immunohistochemical analysis of ileal muscle muscarinic receptor subtypes was correlated with contractile responses. RESULTS: Bethanechol induced a concentration-dependent ileal contraction at all 3 age groups. Adult ileal maximal tension was 2-fold higher than that of the fetus and newborn, while 50% effective concentration (EC(50)) was similar at all ages. Atropine (10(-6)mol/L) inhibited contractility in fetal (67%+/-7%), newborn (82%+/-5%), and adult (97%+/-2%) in an age-dependent manner. The M3 antagonist exhibited robust inhibition at all age groups while the M2 antagonist demonstrated enhanced inhibition in the fetus. Immunohistochemical analysis indicated coexpression of subtype receptors in fetal, newborn, and adult ileal smooth muscle with increasing expression with advancing age. CONCLUSION: These results demonstrate a specific developmental pattern of muscarinic receptor subtype expression. Knowledge and/or alterations of GI motility regulation may aid in the treatment of the preterm fetus or newborn.