Construction of three-dimensional tooth model by micro-computed tomography and application for data sharing

The study of dental morphology is essential in terms of phylogeny. Advances in three-dimensional (3D) measurement devices have enabled us to make 3D images of teeth without destruction of samples. However, raw fundamental data on tooth shape requires complex equipment and techniques. An online database of 3D teeth models is therefore indispensable. We aimed to explore the basic methodology for constructing 3D teeth models, with application for data sharing. Geometric information on the human permanent upper left incisor was obtained using micro-computed tomography (micro-CT). Enamel, dentine, and pulp were segmented by thresholding of different gray-scale intensities. Segmented data were separately exported in STereo-Lithography Interface Format (STL). STL data were converted to Wavefront OBJ (OBJect), as many 3D computer graphics programs support the Wavefront OBJ format. Data were also applied to Quick Time Virtual Reality (QTVR) format, which allows the image to be viewed from any direction. In addition to Wavefront OBJ and QTVR data, the original CT series were provided as 16-bit Tag Image File Format (TIFF) images on the website. In conclusion, 3D teeth models were constructed in general-purpose data formats, using micro-CT and commercially available programs. Teeth models that can be used widely would benefit all those who study dental morphology.

Poor postoperative blood glucose control increases surgical site infections after surgery for hepato-biliary-pancreatic cancer: a prospective study in a high-volume institute in Japan

Two hundred and sixty-five consecutive patients awaiting hepato-biliary-pancreatic surgery were prospectively observed for surgical site infections (SSIs). SSI rates differed according to type of hepato-biliary-pancreatic surgery. Multivariate analysis identified enteric anastomoses, poor postoperative blood glucose control and type of cancer as independent risk factors. SSI rates were directly correlated with the degree of hyperglycaemia encountered during the postoperative period. In particular, SSI rates were 5/25 (20%) among patients in whom a blood glucose level of <200mg/dL was maintained by insulin infusion therapy, which was significantly better than the rates of 49/94 (52%) among patients in whom a blood glucose level of <200mg/dL was not maintained despite insulin infusion therapy (P<0.01). It is necessary to maintain postoperative blood glucose levels of <200mg/dL in order to reduce SSI rates.

Homer1c interacts with Hippi and protects striatal neurons from apoptosis

By the two hybrid screening of mouse brain cDNA library, we identified Hppi, a cell death-promoting protein, as a binding partner of postsynaptic scaffold protein Homer1c. Hippi interacted specifically with Homer1c but not with its homologue Homer2. It was reported that Hippi, when complexed with Hip1, induces the apoptosis in striatal neurons and may cause Huntington's disease. We found that this apoptotic effect of Hippi was specific to the striatum and was not observed in hippocampal neurons. Furthermore, the apoptotic effect of Hippi was prevented when Homer1c was co-expressed in cultured striatal neurons. The protective effect of Homer1c was diminished when Hippi binding domain was deleted. These results suggest that Homer1c may play an important role in the mechanisms of neuronal death in the striatum.

Sensitive fluorescence in situ hybridization signal detection in maize using directly labeled probes produced by high concentration DNA polymerase nick translation

The signal produced by fluorescence in situ hybridization (FISH) often is inconsistent among cells and sensitivity is low. Small DNA targets on the chromatin are difficult to detect. We report here an improved nick translation procedure for Texas red and Alexa Fluor 488 direct labeling of FISH probes. Brighter probes can be obtained by adding excess DNA polymerase I. Using such probes, a 30 kb yeast transgene, and the rp1, rp3 and zein multigene clusters were clearly detected.

Drug eruptions to contrast media in Japan

BACKGROUND

In Japan, drug eruptions to nonionic iodinated contrast media have been reported since the products appeared on the market in 1986.

OBJECTIVES

To evaluate this clinical finding, we analysed the number of patients with drug eruption to contrast media in our hospital from 1989 to 2003.

METHODS

In total, 117 patients suspected of such drug eruptions were patch and intradermal tested with contrast media (as commercially sold). Those who tested positive were evaluated.

RESULTS

Of the 117 patients, 69 patients (19 men; 50 women, mean +/- SD age 51.4 +/- 16.5 years, range 17-86) showed positive reactions to contrast media. The number was 6-13 annually from 1989 to 1995, and 1-4 annually from 1996 to 2003.

CONCLUSION

Although our data suggest (but do not prove) that patients with drug eruption to contrast media decreased in number, this condition is still not rare in Japan. Higher annual exposure to contrast media, including pretesting, could play an important role in this observation.

Stimulation of primary motor cortex for intractable deafferentation pain

To treat intractable deafferentation pains, we prefer stimulation of the primary motor cortex (M1). The methods of stimulation we utilize are electrical stimulation and repetitive transcranial magnetic stimulation (rTMS). In our department, we first attempt rTMS, and if this rTMS is effective, we recommend the patient to undergo procedures for motor cortex stimulation (MCS). A 90% intensity of resting motor threshold setting is used for rTMS treatment. In this study ten trains of 5 Hz rTMS for 10 seconds (50 seconds resting interval) were applied to the M1, S1, pre-motor and supplementary motor areas. Only M1 stimulation was effective for pain reduction in 10 of 20 patients (50%). Twenty-nine MCS procedures were performed by subdural implantation of electrodes, and in the case of hand or face pain, electrodes were implanted within the central sulcus (11 cases), because the main part of M1 is located in the central sulcus in humans. The success rate of MCS was around 63%, and seemed to be higher in cases of pain with spinal cord and peripheral origins, while it was lower in cases of post-stroke pain.

Endoscope Assisted Removal of Jugular Foramen Schwannoma; Report of 3 Cases

Removal of the intraforaminal portion of a jugular foramen schwannoma under direct vision requires resection of the adjacent bone. Extensive resection of the bone around the jugular foramen, however, involves a potential danger for cerebrospinal fluid (CSF) leakage and for damage to the adjacent cranial nerves as well as venous outflow. To avoid such bone resection, we applied the endoscope during the removal of a jugular foramen schwannoma through the lateral suboccipital approach. Three patients with schwannomas in the jugular foramen were treated using the lateral suboccipital approach with endoscopic assistance. After the intracranial portion was first removed under the microscope, the residual tumor in the jugular foramen was subsequently removed under the side-viewing endoscope. In all cases the tumor was removed successfully without major complications. The authors conclude that if the cases are selected properly, removal of the schwannoma extending into the jugular foramen is feasible through the conventional lateral suboccipital window under endoscopic assistance.

Minichromosomes derived from the B chromosome of maize

Fourteen minichromosomes derived from the B chromosome of maize are described. The centromeric region of the B chromosome contains a specific repetitive DNA element called the B repeat. This sequence was used to determine the transmission frequency of the different types of minichromosomes over several generations via Southern blot analysis at each generation. In general, the minichromosomes have transmission rates below the theoretical 50% frequency of a univalent chromosome. The gross structure of each minichromosome was determined using fluorescence in situ hybridization (FISH) on root tip chromosome spreads. The presence of the B centromeric repeat and of the adjacent heterochromatic knob sequences was determined for each minichromosome. In two cases, the amount of the centromeric knob repeat is increased relative to the progenitor chromosome. Other isolates have reduced or undetectable levels of the knob sequence. Potential uses of the minichromosomes are discussed.