Evaluation of a mirror-polishing technique for fluorocarbon polymer surfaces for reduction of contamination from containers used in ultratrace analysis

A mirror-polishing technique for fluorocarbon polymer surfaces using high-precision diamond cutting tools was developed. The goal of this technique was the reduction of ultratrace elemental analysis contamination levels of containers fabricated from such mirror-polished materials. Remarkably smooth inner surfaces with degrees of flatness of 0.1 μm peak-to-valley (PTV) for containers fabricated from mirror-polished PTFE materials were obtained, in contrast to degrees of surface flatness of more than 30 μm PTV for commercially available PTFE containers. (Here, PTV denotes the difference between the highest peak and deepest valley in a scanned area of 10 × 10 μm.) Extractable impurity levels for mirror-polished PTFE container surfaces were reduced by more than 1 order of magnitude relative to those of unpolished PTFE containers. The surface conditions of the PTFE containers were observed by atomic force and scanning electron microscopy. The microphotographs so obtained suggest that the degree of surface smoothness of the containers is proportional to their ultratrace metallic contamination levels.

ERK is Involved in Tooth-pressure-induced Fos Expression in Vc Neurons

Discomfort and pain encountered during orthodontic treatment are major problems for patients, but the details of the underlying neural processes and molecular mechanisms are not well-understood. Here we show that noxious tooth mechanical pressure induced by orthodontic elastics resulted in a rapid and transient activation of extracellular signal-regulated protein kinase (ERK) in the trigeminal spinal subnucleus interpolaris and caudalis transition zone (Vi/Vc), trigeminal spinal subnucleus caudalis (Vc), and upper cervical spinal cord (Vc/C2). The phosphorylated ERK (pERK) was observed in neurons but not in astroglia and microglia. Single-plane scanning analysis indicated that the pERK was localized to the nucleus of Vc neurons. In addition, the tooth mechanical pressure led to Fos expression in the pERK-positive Vc neurons that would be suppressed by intrathecal administration of an MEK1/2 inhibitor (PD98059). Taken together, these findings suggest that activation of the ERK signaling cascade following noxious mechanical pressure on the teeth regulates Fos expression in Vc neurons and may thereby contribute to pain associated with orthodontic treatment.

PKCgamma in Vc and C1/C2 is involved in trigeminal neuropathic pain

The aim of the present study was to clarify the involvement of protein kinase Cγ (PKCγ) in the facial neuropathic pain following infraorbital nerve injury. We analyzed the change in PKCγ expression in the trigeminal spinal subnucleus caudalis (Vc) and upper cervical spinal cord (C1/C2) following chronic constriction injury of the infraorbital nerve (ION-CCI). We also studied ION-CCI-mediated mechanical nocifensive behavior in rats. The mechanical head-withdrawal threshold significantly decreased 1 to 14 days after ION-CCI compared with that before ION-CCI and in sham rats. The expression of PKCγ was significantly larger in the ipsilateral Vc compared with the contralateral side in ION-CCI rats 3, 7, and 14 days after ION-CCI. Intrathecal (i.t.) administration of the PKCγ inhibitor chelerythrine prevented an increase in the PKCγ expression in the ipsilateral Vc. Moreover, i.t. administration of chelerythrine annulled ION-CCI-mediated reduction in the head-withdrawal threshold. Taken together, these findings suggest that PKCγ expression in the Vc played an important role in the mechanism of orofacial static mechanical allodynia following trigeminal nerve injury.

Ferrous Iron and Sulfur Oxidation and Ferric Iron Reduction Activities of Thiobacillus ferrooxidans Are Affected by Growth on Ferrous Iron, Sulfur, or a Sulfide Ore

Eight strains of Thiobacillus ferrooxidans (laboratory strains Tf-1 [= ATCC 13661] and Tf-2 [= ATCC 19859] and mine isolates SM-1, SM-2, SM-3, SM-4, SM-5, and SM-8) and three strains of Thiobacillus thiooxidans (laboratory strain Tt [= ATCC 8085] and mine isolates SM-6 and SM-7) were grown on ferrous iron (Fe), elemental sulfur (S), or sulfide ore (Fe, Cu, and Zn). The cells were studied for their aerobic Fe - and S-oxidizing activities (O(2) consumption) and anaerobic S-oxidizing activity with ferric iron (Fe) (Fe formation). Fe-grown T. ferrooxidans cells oxidized S aerobically at a rate of 2 to 4% of the Fe oxidation rate. The rate of anaerobic S oxidation with Fe was equal to the aerobic oxidation rate in SM-1, SM-3, SM-4, and SM-5, but was only one-half or less that in Tf-1, Tf-2, SM-2, and SM-8. Transition from growth on Fe to that on S produced cells with relatively undiminished Fe oxidation activities and increased S oxidation (both aerobic and anaerobic) activities in Tf-2, SM-4, and SM-5, whereas it produced cells with dramatically reduced Fe oxidation and anaerobic S oxidation activities in Tf-1, SM-1, SM-2, SM-3, and SM-8. Growth on ore 1 of metal-leaching Fe-grown strains and on ore 2 of all Fe-grown strains resulted in very high yields of cells with high Fe and S oxidation (both aerobic and anaerobic) activities with similar ratios of various activities. Sulfur-grown Tf-2, SM-1, SM-4, SM-6, SM-7, and SM-8 cultures leached metals from ore 3, and Tf-2 and SM-4 cells recovered showed activity ratios similar to those of other ore-grown cells. It is concluded that all the T. ferrooxidans strains studied have the ability to produce cells with Fe and S oxidation and Fe reduction activities, but their levels are influenced by growth substrates and strain differences.

Oxidation of Elemental Sulfur to Sulfite by Thiobacillus thiooxidans Cells

Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O(2) consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.

Synergistic Competitive Inhibition of Ferrous Iron Oxidation by Thiobacillus ferrooxidans by Increasing Concentrations of Ferric Iron and Cells

Oxidation of ferrous iron by Thiobacillus ferrooxidans SM-4 was inhibited competitively by increasing concentrations of ferric iron or cells. A kinetic analysis showed that binding of one inhibitor did not exclude binding of the other and led to synergistic inhibition by the two inhibitors. Binding of one inhibitor, however, was affected by the other inhibitor, and the apparent inhibition constant increased with increasing concentrations of the other inhibitor.

Cell Hydrophobicity and Sulfur Adhesion of Thiobacillus thiooxidans

Thiobacillus thiooxidans cells became more hydrophobic but less adhesive to elemental sulfur in the presence of increasing potassium phosphate concentrations. At a fixed concentration of potassium phosphate, however, there was a peak of both cell hydrophobicity and adhesion to sulfur at around pH 5. Oxidation of sulfur by the cells was affected in a complex manner by the phosphate concentration and pH, although it was inhibited by a high concentration of potassium phosphate.

Clinical manifestation and treatment strategy for non hemorrhagic cerebral arterial dissection

Spontaneous dissections of cerebral and cervical artery are relatively uncommon lesions in Japan. Although reported cases of cerebral and cervical arterial dissection are gradually increasing, natural history and optimal treatment remain unclear. The purpose of this study was to clarify the clinical features, natural history, and optimal treatment for patients suffering from non-hemorrhagic cerebral arterial dissection. Fifty-four males and 14 females with cerebral or cervical arterial dissection were treated between January 1998 and December 2003 at the Stroke Center, Sendal Medical Center in Japan. Although most patients suffering from non-hemorrhagic cerebral arterial dissection recover well by conservative treatments, some cases require surgical treatment if they are complicated by enlargement of aneurysms, cerebral ischemia due to bilateral vertebral arterial dissection.

Pattern modification of a neuronal network for individual-cell-based electrophysiological measurement using photothermal etching of an agarose architecture with a multielectrode array

A new type of individual-cell-based on-chip multielectrode array (MEA) cell-cultivation system with an agarose microchamber (AMC) array for topographical control of the network patterns of a living neuronal network has been developed. The advantages of this system are that it allows control of the cell positions and numbers for cultivation using AMCs, as well as easy and flexible control of the pattern of connections between the AMCs through photothermal etching where a portion of the agarose layer is melted with a 1480 nm infrared laser beam. With adequate laser power, narrow micrometer-order grooves (microchannels) can easily be fabricated that can be used to combine neighbouring AMCs to enable topographical control of the neural network pattern. Using this system, an individual-cell-based neural network pattern was formed of rat hippocampal cells within the AMC array without cells escaping from the electrode positions in the microchamber during an eight-day cultivation, and could record cell firing in response to 1.5 V, 500 kHz stimulation through an electrode. This demonstrated the potential of the on-chip AMCMEA cell cultivation system for long-term single-cell-based electrophysiological measurement of a neural network system.

Low expression of fragile histidine triad gene correlates with high proliferation in head and neck squamous cell carcinoma

Frequent loss of heterozygosity in head and neck squamous cell carcinoma (HNSCC) has been found in several chromosomal regions such as 3p, 9p, 11q, 13q and 17p. Fragile histidine triad (FHIT) gene is located at 3p14.2 encompassing a common fragile site, and is identified as a tumor suppressor gene. We examined 57 patients with HNSCC using immunohistochemistry, western blot, and reverse transcriptase polymerase chain reaction. The association between FHIT expression and clinicopathologic characteristics including p53 and Ki-67 expressions was analyzed. Immunohistochemical analysis revealed 30 patients (53%) of low FHIT expression and 27 patients (47%) of high FHIT expression. Low FHIT expression significantly correlated with high Ki-67 expression, indicating that tumor cells with low FHIT expression can proliferate aggressively. No correlation was found between FHIT expression and clinical characteristics including age, gender, tumor size, lymph node status, stage grouping, histologic grade, p53 expression, and prognosis. FHIT alteration may play an important role in cancer development of HNSCC, however it did not contribute to the prognosis.

Intrauterine death of one twin, with rescue of the other, in twin-twin transfusion syndrome

Single intrauterine death may occur in twin-twin transfusion syndrome. We investigated why the outcome of the surviving twin is fairly good when the donor twin dies first compared with when the recipient twin dies first. A detailed hemodynamic study was performed using Doppler ultrasound in a twin pregnancy affected by twin-twin transfusion syndrome before and after a single intrauterine death that occurred in the donor twin at 26 weeks' gestation. The recipient twin was expected to die due to severe right cardiac failure with functional stenosis of the pulmonary artery 2 days before the cotwin's death. The donor twin's death caused a prompt resolution of cardiac failure and improvement in other indices, including flow velocity waveform patterns of the umbilical vein, the middle cerebral artery and the ductus venosus. A healthy, premature female neonate weighing 1630 g with a hemoglobin concentration of 17.8 g/dL was delivered by Cesarean section following rupture of the fetal membranes 28 days after the episode. Hemorrhaging from the surviving twin to the dead twin that occurred just before or after the cotwin's death may have contributed to the decrease in volume overload in the recipient twin, leading to a prompt amelioration of the critical hemodynamic indices. The early death of the donor twin may thus have played a significant role in improving the status of the recipient twin in this case of twin-twin transfusion syndrome.

Clinical features and medical treatment of male prolactinomas

BACKGROUND

Prolactinomas found in male patients show distinct clinical features compared to those in female patients, which may warrant a different treatment strategy.

METHOD

To clarify their clinical features and to evaluate the treatment results, specifically the results of surgical treatment and non-surgical treatment solely with oral bromocriptine, we retrospectively reviewed our experience in male prolactinoma cases.

FINDINGS

From 1988 to 1998, we had 184 pituitary adenoma patients, and thirteen of those were male patients with a pure prolactinoma. Of the thirteen patients, eight underwent transsphenoidal surgery followed by oral bromocriptine (surgical group), and five were treated solely with bromocriptine or terguride (non-surgical group). In both groups, the visual symptoms and signs resolved after the treatment, and the serum prolactin levels were normalised with minimal maintenance dose of bromocriptine. Notably, improvement of the visual symptom in the three non-surgically treated patients was observed within a week following the bromocriptine administration.

INTERPRETATION

Although surgery would continue to play an important part of treatment in some cases with a large tumour, our experience suggests that drug treatment without surgery can be a safe and effective option in the management of male prolactinoma patients.

Pyridoxal 5'-phosphate inhibits DNA binding of HNF1

An efficient Escherichia coli expression system was constructed for the production of a variant form of HNF1 protein having the additional five amino acid residues (Asp-Arg-Trp-Gly-Ser) at the NH(2)-terminal. The cDNA encoding HNF1 was ligated to 6 x His tag and inserted into an inducible bacterial expression vector pRSET A. After expression in E. coli, the recombinant product was purified by Ni-NTA affinity column chromatography. The purified product showed expected NH(2)-terminal sequence and specific binding to the HNF1 site. The effect of pyridoxal 5'-phosphate and its analogues on the binding activity of recombinant HNF1 was examined and found that only pyridoxal 5'-phosphate effectively inhibited the DNA binding. The concentration of pyridoxal 5'-phosphate that inhibited 50% of DNA binding was around 100 microM. Furthermore, we identified Lys197 of HNF1 molecule as the essential residue of DNA binding. These observations suggest that pyridoxal 5'-phosphate directly interacts with tissue-specific transcription factor HNF1 and modulates the binding to DNA.

Liver dysfunction in late pregnancy: cytomegalovirus-induced hepatitis or the HELLP syndrome?

A 27-year-old primiparous preeclamptic woman developed a skin rash in late pregnancy and was persistently febrile for 10 days after giving birth. Blood tests suggested that she developed the HELLP syndrome and had concomitant cytomegalovirus (CMV) infection. Hemolysis, slightly impaired liver function, and thrombocytopenia were explainable by either only the CMV infection or only the HELLP syndrome. A literature review of a limited number of such cases and our case suggests that laboratory data in patients with CMV infection can mimic those of the HELLP syndrome. Thus, it may be important to consider CMV infection as a possible cause of abnormal laboratory data similar to the HELLP syndrome.

Magnetic resonance imaging and clinical findings examined in adulthood-studies on three adults with Rett syndrome

PURPOSE

To clarify magnetic resonance imaging (MRI) findings in three adult patients with Rett syndrome who had been diagnosed with mental retardation and autism.

METHOD

Clinical and MRI findings in three adult cases with Rett syndrome were studied. Ages (in years) in three adult cases with Rett Syndrome were 46 in Case 1, 35 in Case 2 and 20 in Case 3. They were able to walk and their convulsions were well controlled.

RESULTS

MRI findings in all patients showed mild cerebral atrophy, especially in the frontal and temporal lobes and two of the cases also had mild cerebellar atrophy. One case also showed a narrowing of the brainstem and thinning of the corpus callosum.

CONCLUSIONS

These results indicate that abnormalities in MRI imaging, in cases where there is narrowing of the brainstem and thinning of the corpus callosum, may be due to congenital hypoplasia. It was also seen that cerebellar atrophy became more distinct in older cases.

Failure of low-dose radiosurgery to control temporal lobe epilepsy

Radiosurgical treatment of intractable epilepsy has emerged as a noninvasive alternative to resection. Although gamma knife surgery (GKS) reportedly is effective when the radiation dose is sufficient to cause a destructive reaction in the targeted medial temporal lobe, the optimal target area and dose distribution are largely unknown. Some investigators have suggested that focused irradiation from a nondestructive dose is also effective. In this article the authors report two cases of medial temporal lobe epilepsy in which the patients underwent GKS performed using a 50% marginal dose of 18 Gy covering the amygdala. hippocampal head and body, and parahippocampal gyrus. In both cases this procedure failed to control seizures. Both patients became seizure free after undergoing anterior temporal lobectomy 30 and 16 months, respectively, after radiosurgery.