Exploring the oral bacterial flora: current status and future directions

Oral Diseases (2010) 16 , 136–145 Objective: The oral cavity forms an indispensable part of the human microbiome, for its unique and diverse microflora distributed within various niches. While majority of these organisms exhibit commensalism, shifts in bacterial community dynamics cause pathological changes within oral cavity and distant sites. The aim of this review was to appraise the current and emerging methods of detecting bacteria of the oral cavity paying particular attention to the cultivation independent methods. Design: Literature pertaining to cultivation based and cultivation independent methods of oral bacterial identification was reviewed. Methods: The specific advantages and disadvantages of cultivation based, microscopic, immunological and metagenomic identification methods were appraised. Results: Because of their fastidious and exacting growth requirements, cultivation based studies grossly underestimate the extent of bacterial diversity in these polymicrobial infections. Culture independent methods deemed more sensitive in identifying difficult to culture and novel bacterial species. Conclusion: Apart from characterizing potentially novel bacterial species, the nucleic acid sequence data analyzed using various bioinformatics protocols have revealed that there are in excess of 700 bacterial species inhabiting the mouth. Moreover, the latest pyrosequencing based methods have further broadened the extent of bacterial diversity in oral niches.     

Correlation between Hydroxyapatite Crystallite Orientation and Ultrasonic Wave Velocities in Bovine Cortical Bone

The mineral component of bone is mainly composed of calcium phosphate, constituting 70% of total bone mass almost entirely in the form of hydroxyapatite (HAp) crystals. HAp crystals have a hexagonal system and uniaxial elastic anisotropy. The objective of this study was to investigate the effect of HAp crystallite preference on macroscopic elasticity. Ultrasonic longitudinal wave velocity and the orientation of HAp crystallites in bovine cortical bone are discussed, considering microstructure, density, and bone mineral density (BMD). Eighty cube samples of cortical bone were made from two bovine femurs. The orientation of HAp crystallites was evaluated by integrated intensity ratio of (0002) peak using an X-ray diffractometer. Ultrasonic longitudinal wave velocity was investigated with a conventional pulse system. The intensity ratio of HAp crystallites and velocity were measured in three orthogonal directions; most HAp crystallites aligned in the axial direction of the femurs. Our results demonstrate a linear correlation between velocity and intensity ratio in the axial direction. Significant correlation between velocity and BMD values was observed; however, the correlation disappeared if we focused on the identical type of microstructure. In conclusion, differences in microstructure type have an impact on density and BMD, which clearly affects the velocity. In addition, at the nanoscopic level, HAp crystallites aligned in the axial direction also affected the velocity and anisotropy.     

Effects of spinal analgesics on spinal circulation: the safety standpoint

Administration of spinal analgesics around the spinal cord requires safety assessment due to the possibility of inflicting neurotoxic damage. Thus, neurotoxicologic evaluation should be performed for effective, safer spinal antinociception. Every potential agent for spinal administration should be studied in animals for its effects on spinal blood flow or vessels before any attempt is made to administer the drug to humans. As the spinal cord normally has a marginal blood flow, excessive vasoconstriction might produce spinal cord ischemia and consequent neurologic dysfunction. This review therefore focuses on the effects on the spinal circulation induced by well-known spinal analgesics employed in the treatment of acute and chronic pain disorders.     

Chemically synthesized sugar-cholestanols possess a preferential anticancer activity involving promising therapeutic potential against human esophageal cancer

The understanding of the cell signaling pathways and the molecular events leading to cell death of cancer cells will provide in-depth perspective into the identification and development of potent anticancer agents. A balance between cell proliferation and cell death has been raised as a rational target for the management of malignant tumors. In the present study, the authors demonstrated that chemically synthesized sugar-cholestanols consisting of GlcNAcbeta-, Galbeta- and GlcNAcbeta1,3Galbeta-cholestanols exerted a strong inhibiting activity against cell proliferation of esophageal cancer cells, but cholestanol itself did not show such an activity against the same cancer cells at all. In addition to their predominant role as an antiproliferation agent, evidence based on the molecular analyses suggested that sugar-cholestanols played a regulatory role in multiple signal transduction pathways inducing apoptosis through both the death signal-extrinsic and the mitochondria-intrinsic pathways. Sugar-cholestanols seemed to be more susceptible to esophageal cancer cells than to non-cancerous esophageal cells at the very early event of their exposure and, further, to suppress specifically the expression of vascular endothelial growth factor. Taken together, these novel functions of sugar-cholestanols indicate that they could have promising therapeutic potential against human esophageal cancer.     

Case of atypical polypoid adenomyoma that possibly underwent a serial progression from endometrial hyperplasia to carcinoma

Atypical polypoid adenomyoma is a rare uterine tumor composed of atypical endometrial glands, which often exhibit squamous metaplasia, and a cellular smooth muscle stroma. Although atypical polypoid adenomyoma is categorized as a benign lesion, it is reportedly associated with endometrial cancer, and it shows persistence and recurrence even after conservative medical treatment. We present a rare case of atypical polypoid adenomyoma that possibly underwent a serial pathological change from endometrial hyperplasia to carcinoma in a 40-year-old woman with no history of pregnancy. She was diagnosed with atypical polypoid adenomyoma during polypectomy surgery. After resecting the atypical polypoid adenomyoma, endometrial hyperplasia complex was detected. This condition eventually progressed from atypical hyperplasia complex to endometrial adenocarcinoma, and total abdominal hysterectomy was performed. A patient with atypical polypoid adenomyoma who wishes to preserve her fertility should be carefully monitored for endometrial carcinoma. If endometrial hyperplasia is detected in such a patient, a meticulous follow-up examination by performing endometrial biopsy is mandatory.     

Analysis of a nationwide survey on treatment and outcomes of congenital hydrocephalus in Japan

A nationwide questionnaire survey of congenital hydrocephalus in 2000 investigated the treatment and clinical outcomes for congenital hydrocephalus in Japan to evaluate the factors influencing clinical outcome. Surgical treatment was performed in 341 of 380 patients who survived the early neonatal period. Of 321 patients who had shunt operations, 295 (91.9%) underwent ventriculoperitoneal shunting and nine (2.8%) ventriculoatrial shunting. Programmable valves were used in 83 (33.6%) of the 247 patients at the first shunting and in 97 (39.3%) at the last shunting. The incidence of complications after the first shunting was 55.4% (46 of 83 patients) in the programmable and 61.6% (101 of 164) in the non-programmable valve groups. The types of shunt complication differed significantly between these groups (p < 0.001), as the incidence of shunt infection and malfunction was lower in the programmable valve group. Clinical outcome was generally better with later delivery stage during gestation (p < 0.02). The clinical outcome was statistically significantly better in term patients who underwent early shunt placement than in those who underwent late shunt placement (p < 0.05).     

Frenum-like oral synechiae of the lip and vestibule

Two cases where aberrant tissue was attached to the lower lip mimicking the inferior labial frenum were reported. The frenum-like tissue extended from the gingival margin between the lower left deciduous central and lateral incisors in case 1 and between the lower right deciduous central and lateral incisors in case 2, to the dry lower lip. Histologically, the resected specimen was regarded as normal oral mucosa covered with stratified squamous epithelium, without a clear amniotic band. The frenum-like tissue of the lower lip found in both our patients was diagnosed as a category of oral synechiae, of unknown origin.