Development and testing of an endoscopic pseudo-viewpoint alternating system.

PURPOSE: An endoscopic system is needed that presents informative images irrespective of the surgical situation and the number of degrees of freedom in endoscopic manipulation. This goal may be achieved with a virtual reality view for a region of interest from an arbitrary viewpoint. An endoscopic pseudo-viewpoint alternation system for this purpose was developed and tested. METHOD: Surgical experts and trainees from an endoscopic surgery training course at the minimally invasive surgery training center of Kyushu University were enrolled in a trial of a virtual reality system. The initial viewpoint was positioned to approximate the horizontal view often seen in laparoscopic surgery, with [Formula: see text] between the optical axis of the endoscope and the task surface. A right-to-left suturing task with right hand, based on a task from the endoscopic surgery training course, was selected for testing. We compared task outcomes with and without use of a new virtual reality-viewing system. RESULT: There was a 0.37 mm reduction in total error ([Formula: see text]) with use of the proposed system. Error reduction was composed of 0.1 mm reduction on the y-axis and 0.27 mm reduction on the x-axis. Experts benefited more than novices from use of the proposed system. Most subjects worked at a pseudo-viewpoint of around 34[Formula: see text]. DISCUSSION: Suturing performance improved with the new virtual reality endoscopic display system. Viewpoint alternation resulted in an overview that improved depth perception and allowed subjects to better aim the marker. This suggests the proposed method offers users better visualization and control in endoscopic surgery.

[Coronary malperfusion of left main trunk due to localized dissection of the ascending aorta].

Case 1. Forty nine years woman was given a diagnosis of acute myocardial infarction. Coronary angiography and trans-esophageal echocardiography showed left main trunk dissection due to local aortic root dissection. We operated surgical repair at left main trunk by pericardium after percutaneous coronary intervention. Case 2. Forty nine years man was given a diagnosis of acute myocardial infarction caused by left main trunk dissection due to traumatic local aortic root dissection. We operated coronary artery bypass grafting after insertion of perfusion catheter to left main trunk for maintain coronary perfusion. Although local dissection of aortic aorta is relatively rare, it is potentially complicated with coronary malperfusion. We describe 2 success a cases of surgical treatment for local acute type A aortic dissection complicated with coronary malperfusion.

[An epidemiological study for fungus isolation during the twenty-five year periods from 1976 to 2000 in Kitasato University Hospital].

We investigated an epidemiological study for fungus isolation in our hospital from 1976 to 2000. For 25 years, the total sample number of fungus examination were 64,296, and after 1988, the total sample number increased suddenly. As a whole, the positive ratio was constantly about 40%. When our hospital opened, the obstetrical and gynecological samples showed 38.8% for fungus examination, but recently, samples of the respiratory organ has increased. Ratio of isolation for yeast, Candida albicans was 53.8%, and another yeasts such as Candida glabrata, Candida tropicalis, Candida parapsilosis were 12.5%, 5.3%, and 3.4%, respectively. Recently, isolation of Candida glabrata showed a tendency to increase. For genus Aspergillus, Aspergillus fumigatus was isolated, 48.1%, and Aspergillus nigar, Aspergillus terreus were isolated, 31.4% and 7.5%, respectively. For dermatophytes, Trichophyton rubrum was isolated, 63.6% indermatophytes, and another dermatophytes were Microsporum canis (17.9%), and Trichophyton mentagrophytes (15.9%), respectively. For dermatophytes, isolation of Microsporum canis showed a tendency to increase. Recently, the plural number of species showed a tendency to increase in the samples. Compared with the number of samples at the beginning in our hospital, the plural number of species in the samples increased about six times.

Ruptured aneurysm of the visceral artery: report of two cases.

We present herein two cases of a ruptured aneurysm of the visceral artery. The first case involved a 74-year-old man with abdominal pain who was admitted to our hospital with a tentative diagnosis of intra-abdominal bleeding of unknown origin. Computed tomography revealed a hematoma in the greater curvature of the stomach. At surgery, a hematoma along the right gastroepiploic artery was found and totally removed. Histological examination showed a pseudo-aneurysm of unknown etiology. The second case involved a 68-year-old man with progressive anemia who presented with spontaneous intra-abdominal bleeding. A ruptured aneurysm of the accessory middle colic artery was diagnosed by superior mesenteric angiography. The ruptured aneurysm was ligated and totally resected without a colectomy. Histological examination showed a pseudoaneurysm of unknown etiology. The postoperative courses were uneventful, and both patients were doing well at the time of writing.

SADS: A new component of Fas-DISC is the accelerator for cell death signaling and is downregulated in patients with colon carcinoma.

Fas is the death receptor, transducing cell death signaling upon stimulation by Fas ligand. During Fas-initiated cell death signaling, the formation of Fas-death inducing signaling complex (Fas-DISC) is the first step. Here we have identified a new component of Fas-DISC which we call 'small-accelerator for death signaling' (SADS). SADS cDNA encodes a 150 amino acid polypeptide (Mr = 16,700). During Fas-mediated cell death, SADS enhances the interaction of Fas-death domain-interactive factors (FADD) and procaspase-8, and deletion mutant analysis has identified FADD- and caspase-8-interactive domains in SADS. Inhibition or removal of SADS delays Fas-mediated cell death. In addition, we demonstrate the deletion or mutation of SADS in patients with colon carcinoma and that exogenous SADS expression in human colon carcinoma SW480 cells that lack SADS leads to re-acquisition of Fas-mediated cell death. Here, we propose that SADS is one of the cell death-associated factors and enhances Fas-DISC formation, especially FADD and procaspase-8 recruitment.

Extracellular ATP-dependent activation of plasma membrane Ca(2+) pump in HEK-293 cells.

1. It is well known that extracellular ATP (ATP(o)) elevates the intracellular Ca(2+) concentration ([Ca(2+)](i)) by inducing Ca(2+) influx or mobilizing Ca(2+) from internal stores via activation of purinoceptors in the plasma membrane. This study shows that ATP(o) also activates the plasma membrane Ca(2+) pumps (PMCPs) to bring the elevated [Ca(2+)](i) back to the resting level in human embryonic kidney-293 (HEK-293) cells. 2. The duration of ATP(o)-induced intracellular Ca(2+) transients was significantly increased by PMCP blockers, La(3+) or orthovanadate. In contrast, replacement of extracellular Na(+) with NMDG(+), a membrane-impermeable cation, had no significant effect on duration, thus suggesting that Na(+)/Ca(2+) exchangers do not participate in the ATP(o)-induced Ca(2+) transient. 3. A rapid and significant decrease in [Ca(2+)](i), which was not dependent on extracellular Na(+), was induced by ATP(o) in cells pretreated with thapsigargin (TG). This decrease was blocked by orthovanadate, indicating that it was caused by PMCPs rather than sarco/endoplasmic reticulum Ca(2+) pumps (SERCPs). 4. UTP and ATPgammaS also caused a decrease in [Ca(2+)](i) in cells pretreated with TG, although they were less effective than ATP. The effect of UTP implies the involvement of both P2Y(1) and P2Y(2) receptors, while the effect of ATPgammaS implies no significant role of ectophosphorylation and agonist hydrolysis in the agonist-induced [Ca(2+)](i) decreases. 5. These results point to a role of PMCPs in shaping the Ca(2+) signal and in restoring the resting [Ca(2+)](i) level to maintain intracellular Ca(2+) homeostasis after agonist stimulation.

The alcohol tests for drunken criminals using psychological tests.

In the alcohol test for drunken criminals, we introduced Bender-Gestalt test and Rorschach test for the assessment, and examined their usefulness for the evaluation of intoxication patterns according to Binder's classification. The subjects were 24 drunken criminals who were examined by Mental Hygiene Group, Tsukuba University, for psychiatric evidences. The subjects were divided into the ordinary intoxication group (OI group) and the complicated intoxication group (CI group) on the basis of the behavioral assessment, and the psychological tests were performed before and after drinking. The following results were obtained. 1) Alcohol intoxication induced decrease in R1T, W and VIII + IX + X/R and increase of BGT scores and P%, which indicates that subjects become unable to make comprehensive and delicate responses to the external stimuli. 2) When we classified subjects into increasing and decreasing type on the pattern of changes in the BGT score from before to immediately after drinking in each subject, we found the ratio of increasing type in complicated intoxication is more than in ordinary intoxication significantly. And we found significant group x drinking interaction in F+% and At% of Rorschach test. The F+% significantly decreased only in CI group. The At% in CI group tended upward, but downward in OI group. These findings indicated that complicated intoxication reduced the subject's reality testing, while not in ordinary intoxication. 3) Comparing the effects of personality and intoxication factors in complicated intoxication, intoxication factors were considered to play primary roles. 4) We found association between high BAL and reduction of ego function and imagination, which is represented as significant peak of BALx drinking interaction in the BGT scores, M and FM + m. These observations suggest that the psychological tests as part of the alcohol tests are useful for the evaluation and research of intoxication.

A protein disulfide isomerase gene fusion expression system that increases the extracellular productivity of Bacillus brevis.

We have developed a versatile Bacillus brevis expression and secretion system based on the use of fungal protein disulfide isomerase (PDI) as a gene fusion partner. Fusion with PDI increased the extracellular production of heterologous proteins (light chain of immunoglobulin G, 8-fold; geranylgeranyl pyrophosphate synthase, 12-fold). Linkage to PDI prevented the aggregation of the secreted proteins, resulting in high-level accumulation of fusion proteins in soluble and biologically active forms. We also show that the disulfide isomerase activity of PDI in a fusion protein is responsible for the suppression of the aggregation of the protein with intradisulfide, whereas aggregation of the protein without intradisulfide was prevented even when the protein was fused to a mutant PDI whose two active sites were disrupted, suggesting that another PDI function, such as chaperone-like activity, synergistically prevented the aggregation of heterologous proteins in the PDI fusion expression system.

A thermophilic cyanobacterium Synechococcus elongatus has three different Class I prenyltransferase genes.

Prenyltransferases (prenyl diphosphate synthases), which are a broad group of enzymes that catalyze the consecutive condensation of homoallylic diphosphate of isopentenyl diphosphates (IPP, C5) with allylic diphosphates to synthesize prenyl diphosphates of various chain lengths, have highly conserved regions in their amino acid sequences. Based on the above information, three prenyltransferase homologue genes were cloned from a thermophilic cyanobacterium, Synechococcus elongatus. Through analyses of the reaction products of the enzymes encoded by these genes, it was revealed that one encodes a thermolabile geranylgeranyl (C20) diphosphate synthase, another encodes a farnesyl (C15) diphosphate synthase whose optimal reaction temperature is 60 degrees C, and the third one encodes a prenyltransferase whose optimal reaction temperature is 75 degrees C. The last enzyme could catalyze the synthesis of five prenyl diphosphates of farnesyl, geranylgeranyl, geranylfarnesyl (C25), hexaprenyl (C30), and heptaprenyl (C35) diphosphates from dimethylallyl (C5) diphosphate, geranyl (C10) diphosphate, or farnesyl diphosphate as the allylic substrates. The product specificity of this novel kind of enzyme varied according to the ratio of the allylic and homoallylic substrates. The situations of these three S. elongatus enzymes in a phylogenetic tree of prenyltransferases are discussed in comparison with a mesophilic cyanobacterium of Synechocystis PCC6803, whose complete genome has been reported by Kaneko et al. (1996).

Intrahepatic cholangiocarcinoma with extensive sarcomatous change: report of a case.

A 77-year-old woman was admitted to our hospital with severe upper abdominal pain. Ultrasonography showed a well-defined hypoechoic mass with heterogeneity in the left lobe of the liver, and computed tomography demonstrated a low-density mass with enhanced peripheral areas. Magnetic resonance imaging revealed a mass with iso- to low signal intensity on T1-weighted images (WI) and heterogeneous high and low signal intensity on T2 WI. The tumor was found to be hypovascular by angiography. During 5 months of observation, the tumor increased in size, which strongly suggested malignancy. A laparotomy was performed under the provisional diagnosis of a neoplasm other than hepatocellular carcinoma, revealing that the hepatic mass had invaded the gastric wall. Therefore, a left hepatic lobectomy with dissection of the lymph nodes and hemigastrectomy was carried out. Histologically, the tumor was found to be composed of a large amount of sarcomatous elements and a small amount of adenocarcinomatous elements, both of which were partly intermingled. Immunohistochemically, the sarcomatous element demonstrated the features of malignant fibrous histiocytoma (MFH). Thus, a diagnosis of intrahepatic cholangiocarcinoma with MFH-like sarcomatous change was confirmed.

Molecular correlates of topographic reorganization in primary visual cortex following retinal lesions.

Adult visual cortex undergoes substantial functional change as a result of alterations in visual experience. Binocular retinal lesions lead to a reorganization of the visuotopic map in primary visual cortex. Associated with this change is a strengthening of an existing plexus of long-range horizontal connections by sprouting of axon collaterals and synaptogenesis. To explore the molecular substrate of this change, we studied the expression of potential factors involved in neural plasticity in the area of reorganization. We found elevation in a number of factors as early as 3 days following the lesion, including neurotrophins BDNF, NT3, NGF and the insulin-like growth factor IGF-1. Associated with the changes in neurotrophin levels was an elevation in their receptors. We also measured elevation of transcription factors, CaMKII, MAP2 and synapsins. These experiments provide evidence for a signal transduction cascade associated with cortical reorganization.

Gene cloning and overexpression of a geranylgeranyl diphosphate synthase of an extremely thermophilic bacterium, Thermus thermophilus.

A geranylgeranyl diphosphate (GGPP) synthase gene of an extremely thermophilic bacterium, Thermus thermophilus, was cloned and sequenced. T. thermophilus GGPP synthase, overexpressed in Escherichia coli cells as a glutathione S-transferase fusion protein, was purified and characterized. The fusion protein, retaining thermostability, formed a homodimer, and showed higher specific activity than did a partially purified thermostable enzyme previously reported. Optimal reaction conditions and kinetic parameters were also examined. The deduced amino acid sequence indicated that T. thermophilus GGPP synthase was excluded from the group of bacterial type GGPP synthases and lacked the insertion amino acid residues in the first aspartate-rich motif as do archaeal and eukaryotic short-chain prenyltransferases.

A common protocadherin tail: multiple protocadherins share the same sequence in their cytoplasmic domains and are expressed in different regions of brain.

To study the diversity of protocadherins, a rat brain cDNA library was screened using a cDNA for the cytoplasmic domain of human protocadherin Pcdh2 as a probe. The resultant clones contained three different types. One type corresponds to rat Pcdh2; the other two types are distinct from Pcdh2 but contain the same sequence in their cytoplasmic domains and part of the 3' flanking sequence. To clarify the structure of the proteins defined by the new clones, a putative entire coding sequence corresponding to one of the clones was determined. The overall structure is essentially the same as Pcdh2, indicating that the proteins defined by this clone, and probably by other clones, belong to the protocadherin family. Two PCR experiments and an RNase protection assay showed the existence of the corresponding mRNAs in rat brain preparations. Human and mouse cDNA clones with the same sequence properties were also isolated. Taken together, these results indicate that the clones are not cloning artifacts and that corresponding mRNAs are actually expressed in brains of various species. The results of in situ hybridization showed that the mRNAs corresponding to these clones were expressed in different regions in brain. Since protocadherins encoded by these mRNAs are likely to have different specificity in their interaction and share a common activity at their cytoplasmic domains, these protocadherins may provide a molecular basis, in part, to support the complex cell cell interaction in brain.

Peroxide production and apoptosis in cultured cells carrying mtDNA mutation causing encephalomyopathy.

When cybrids with a point mutation, which locates in the tRNALeu(UUR) gene of mtDNA and causes a mitochondrial encephalomyopathy (MELAS syndrome), were exposed to a high concentration of oxygen (95%), the peroxide production markedly increased by 6 h of oxygen exposure, whereas the peroxide production was similar among the cybrids under a normal concentration of oxygen. The peroxide production by oxygen exposure was enhanced particularly in cybrids with high proportions of the mutant mtDNA and low respiratory capacities. The appearance of apoptotic cells by oxygen exposure was high in cybrids with the impaired respiratory function due to the mutation. An antioxidant NAC successfully suppressed both the peroxide production and apoptosis. These results imply that the peroxide production plays an important role in inducing apoptosis in cells carrying the mtDNA mutation causing encephalomyopathy.

Overexpression of an archaeal geranylgeranyl diphosphate synthase in Escherichia coli cells.

An archaeal geranylgeranyl diphosphate synthase was overexpressed in Escherichia coli cells as fusion proteins. These fusion proteins retained their thermostability and had higher specific activity than did a partially purified native enzyme Previously reported. We purified 24.3 mg of MBP (maltose-binding protein)-fusion protein and 5.4 mg of GST (glutathione S-transferase)-fusion protein from a one-liter culture of E. coli. The MBP-fusion proteins existed in dimer, tetramer, octamer, or dodecamer form, and their product specificities were altered according to the oligomerization. The MBP-fusion protein has protease-sensitive sites in the portion corresponding to geranylgeranyl diphosphate synthase.

Molecular properties and chromosomal location of cadherin-8.

Cloning of rat cadherin-8 cDNA demonstrated two types of cDNAs. The overall structure of the protein defined by one type of the cDNA is essentially the same as that of classic cadherins, whereas the protein defined by the other type of cDNA ends near the N-terminus of the fifth repeat of the extracellular domain (EC5) and contains a short unique sequence at the C-terminus. The same truncated type of cDNA was also obtained from a human cDNA library. In Northern blot analysis of rat brain mRNA, a probe for EC5 detected multiple bands of about 3.5-4.3 knt, whereas a probe for the alternative form hybridized with a band of about 3.5 knt. Western blot experiments showed that an antibody against the extracellular domain of rat cadherin-8 stained a band of about 95 kDa and a faint band of about 130 kDa in rat brain extract. These results suggest that cadherin-8 is expressed in two forms, a complete form and a truncated form without a transmembrane domain or cytoplasmic domain, in brain. The complete form of cadherin-8 expressed in L cells was about 130 kDa in molecular mass and was located at the cell periphery, mainly at the cell-cell contact sites. However, we failed to express the truncated form in L cells. The transfectants of the complete form showed weak cell adhesion activity. The complete form of cadherin-8 was sensitive to trypsin digestion, and Ca2+ did not protect cadherin-8 from digestion, in contrast to the classic cadherins. The complete form of cadherin-8 coprecipitated with beta-catenin, but did not immunoprecipitate well with alpha-catenin or gamma-catenin. Cadherin-8, as well as cadherin-11, was mapped to a specific region of chromosome 8 that also includes cadherins-1, -3, and -5.

Fluid-fluid levels in giant cavernous hemangioma of the liver: CT and MRI demonstration.

Fluid-fluid levels were observed in a case of giant cavernous hemangioma on computed tomography (CT) and magnetic resonance (MR) imaging. The fluid-fluid level may be attributed to the separation of blood cells and serous fluid due to the extremely slow flow in cavernous hemangioma of the liver.

Functional cloning of a cDNA encoding Mei2-like protein from Arabidopsis thaliana using a fission yeast pheromone receptor deficient mutant.

To isolate Arabidopsis cDNAs that encode signal transducers and components involved in the regulation of meiosis, a trans-complementation analysis was performed using a Schizosaccharomyces pombe meiosis-defective mutant in which the genes for pheromone receptors were disabled. One cDNA obtained in this screening encodes a polypeptide, named AML1, that shows significant similarity to S. pombe Mei2 protein and has three putative RNA-recognition motifs like as Mei2. Mei2 is involved in the regulation of meiosis in fission yeast. Northern blot analysis showed that the AML1 gene is expressed in each organ. The possible functions of AML1 are discussed.