Purification, primary structure, and evolution of cytochrome c-550 from the magnetic bacterium, Magnetospirillum magnetotacticum

Cytochrome c-550 was purified from Magnetospirillum magnetotacticum to an electrophoretically homogeneous state, and some of its properties were determined. The cytochrome showed absorption peaks at 528 and 409 nm in the oxidized form, and at 550, 521, and 414 nm in the reduced form. Its midpoint redox potential at pH 7.0 was determined to be +289 mV. The primary structure of cytochrome c-550 was determined. Cytochrome c is composed of 97 amino acid residues, and its molecular weight was calculated to be 10,873, including heme c. Its primary structure is very similar to those of Rhodospirillum fulvum and Rhodospirillum molischianum cytochromes c2, suggesting that M. magnetotacticum is phylogenetically related to photosynthetic bacteria.

Morphological changes in human cerebral arteries after percutaneous transluminal angioplasty for vasospasm caused by subarachnoid hemorrhage

Light and electron microscopy were used to study morphological changes in cerebral arteries after percutaneous transluminal angioplasty (PTA) for vasospasm in two patients with aneurysmal subarachnoid hemorrhage. One patient died of gastric bleeding 5 days after PTA. Postmortem examination of the inflated middle cerebral arteries revealed heterogeneously extended walls and dilated lumina. Throughout the vessel walls, the extracellular matrix, which was composed of nonmuscle components such as increased collagen, was stretched in conjunction with the medial muscle component. Also, torn and thinned areas of the wall and intramural hemorrhages were caused by overinflation. The second patient died of massive cerebral infarction caused by diffuse vasospasm 5 days after PTA. Prominent stretching of the walls at the atheromatous plaque margin in the dilated vessel was found in addition to the morphological changes observed in the first patient. These observations suggest that characteristic pathological alterations might be present in the vessel wall at the site of angioplasty. The major mechanism of the long-lasting effects of PTA seems to be the stretching and disruption of both the degenerative muscle and the proliferative nonmuscle components, mainly in the media of the vasospastic vessels.

Wild-type human p53 and a temperature-sensitive mutant induce Fas/APO-1 expression

Fas/APO-1 is a cell surface protein known to trigger apoptosis upon specific antibody engagement. Because wild-type p53 can activate transcription as well as induce apoptosis, we queried whether p53 might upregulate Fas/APO-1. To explore this possibility, we examined human p53-null (H358 non-small-cell lung adenocarcinoma and K562 erythroleukemia) and wild-type p53-containing (H460 non-small-cell lung adenocarcinoma) cell lines. When H358 or H460 cells were transduced with a replication-deficient adenovirus expression construct containing the human wild-type p53 gene but not with vector alone, a marked upregulation (approximately a three-to fourfold increase) of cell surface Fas/APO-1 was observed by flow cytometry. Similarly, K562, cells stably transfected with a plasmid vector containing the temperature-sensitive human p53 mutant Ala-143 demonstrated a four- to sixfold upregulation of Fas/APO-1 by flow-cytometric analysis at the permissive temperature of 32.5 degrees C. Temperature-sensitive upregulation of Fas/APO-1 in K562 Ala-143 cells was verified by immunoprecipitation and demonstrated to result from enhanced mRNA production by nuclear run-on and Northern (RNA) analyses. Stably transfected K562 cells expressing temperature-insensitive, transcriptionally inactive p53 mutants (His-175, Trp-248, His-273, or Gly-281) failed to upregulate Fas/APO-1 at either 32.5 degrees or 37.5 degrees C. The temperature-sensitive transcription of Fas/APO-1 occurred in the presence of cycloheximide, indicating that de novo protein synthesis was not required and suggested a direct involvement of p53. Collectively, these observations argue that Fas/APO-1 is a target gene for transcriptional activation by p53.

Desmoyokin/AHNAK protein localizes to the non-desmosomal keratinocyte cell surface of human epidermis

Desmoyokin, a high-molecular-weight protein of 680 kD with a 170-nm-long dumbbell shape, was originally thought to be localized to the desmosomal attachment plaque and to work as a kind of stabilizer of desmosomes. Recently, desmoyokin was shown to be widely detected in many types of cells that do not possess desmosomes. The purpose of the present study was to elucidate the precise localization and possible function of desmoyokin in human epidermis. In 0.2-micron ultrathin cryosections of human skin for immunofluorescence, anti-desmoyokin antibody showed a ladder-like staining pattern along the cell surface, whereas anti-desmocollin and anti-desmoplakin antibodies as controls showed a discontinuous dotted staining pattern, indicating their distinct localization. Post-embedding immunoelectron microscopy with cryofixation and cryosubstitution revealed that desmoyokin was localized mainly along the non-desmosomal and non-hemidesmosomal plasma membrane, but not to the desmosomes and hemidesmosomes themselves. This localization was further confirmed by double-labeling immunoelectron microscopy with antibodies against desmocollin, desmoplakin, or bullous pemphigoid antigen. Results indicate that desmoyokin was not localized to the desmosomes themselves as previously considered. Desmoyokin was localized to the non-desmosomal and non-hemidesmosomal epidermal keratinocyte cell surface as a plasma membrane-associated protein, and might play a role in cell adhesion that is not directly associated with desmosomes or hemidesmosomes.

Human papillomavirus DNA in cell lines derived from malignancies

The presence of high-risk types of human papillomavirus (HPV) 16, 18 and 33 in cell lines established from several malignancies including 5 of cervical cancer and 6 of head and neck cancer was studied. HPV DNA, either type 16 or 18, was detected by polymerase chain reaction, and by Southern blot hybridization in all of the cell lines derived from cervical cancers. The hybridization patterns of HPV DNA after endonuclease digestion differed among cell lines, suggesting that all of these cell lines were independent isolates. Accordingly, high-risk types of HPV DNA seem to be ubiquitous in cervical cancer. HPV DNA was not detected in the cell lines derived from head and neck cancers or from any other malignancies besides cervical cancer in this study.

Microdomain formation in phosphatidylethanolamine bilayers detected by 2H-NMR

In deuterium NMR spectra of phosphatidylethanolamine bilayers with an extremely high content of saturated fatty acids, each C1 deuteron of the glycerol backbone gave rise to a doublet [Yoshikawa et al., (1988) Biochim. Biophys. Acta 944, 321-328]. This suggests the presence of two backbone conformations, the exchange between which is slow on an NMR time-scale. The origin of the two conformations has been investigated in this work using saturated 1,2-diacyl-sn-glycero-3-phosphoethanolamine specifically deuterated in the glycerol backbone. The results showed that the two conformations originate from different domains, which have different fatty acid compositions. The differential scanning calorimetry of the bilayers suggested that the size of the domain is not large enough to show an independent phase transition. Thus, the formation of microdomains in the phosphatidylethanolamine bilayers has been concluded. Conformational difference in different domains was shown to be restricted to the C1 position of the glycerol backbone. The microdomains of phosphatidylethanolamine were retained even in the presence of other phospholipids.

Post-ischemic changes of [3H]glycine binding in the gerbil brain after cerebral ischemia

Sequential changes of [3H]glycine binding in the gerbil were investigated in selectively vulnerable areas 1 h to 7 days after 10 min of cerebral ischemia. A significant reduction in [3H]glycine binding was found in the hippocampus and thalamus from as early as 1 h after ischemia. In contrast, the striatum and frontal cortex showed a significant decline in [3H]glycine binding from 5 h after recirculation. Thereafter, a severe reduction in [3H]glycine binding was observed in all regions 7 days after ischemia. MAP2 (microtubule-associated protein 2) immunoreactivity was unaffected in the hippocampus, frontal cortex and thalamus up to 48 h after ischemia. Thereafter, a severe loss of MAP2-immunoreactive neurons was found in these regions, especially in the hippocampal CA1 sector. However, the striatum showed a severe loss of MAP2 immunoreactivity from 24 h after ischemia. These results demonstrate that transient cerebral ischemia causes severe reduction in [3H]glycine binding throughout the brain, and this reduction precedes the neuronal damage in selectively vulnerable areas. These findings suggest that a neurotransmitter, glycine, may play a key role in the pathogenesis of post-ischemic neurodegeneration in selectively vulnerable areas.

Different roles of bases within the integration signal sequence of human immunodeficiency virus type 1 in vitro

To investigate the roles of bases near the tips of each strand of the long terminal repeat of the human immunodeficiency virus type 1 in the integration reaction, we examined the efficiencies of both binding and integration activities of staggered-ended substrates and mismatched mutant substrates by the integration assay and the UV cross-linking assay. Our results suggest that some bases of the human immunodeficiency virus type 1 long terminal repeat are required primarily for binding, whereas others are more critical for later reaction steps in vitro.

Crystallization and preliminary X-ray analysis of cytochrome c-554 from Nitrosomonas europaea

Cytochrome c-554 from Nitrosomonas europaea was crystallized by the batch method utilizing ammonium sulfate as the precipitant. The crystals belong to the space group, P21, with unit cell dimensions of a = 64.8 A, b = 44.7 A, c = 78.7 A, and beta = 99.0 degrees. The crystals diffracted X-rays beyond 2.5 A resolution.

Hepatocellular carcinoma metastatic to the mandible

A case of hepatocellular carcinoma metastatic to the mandible is described. The patient reported swelling, pain, and trismus after a pathologic fracture. After a systematic examination with the use of 99mTc-methylene diphosphonate, 67Ga-citrate, and 99mTc-pyridoxyl-5-methyl triptophan scintigraphy the primary focus was discovered in the right lobe of the liver. The focus was confirmed by computed tomography and magnetic resonance imaging. The histopathologic diagnosis of hepatocellular carcinoma was made from a biopsy specimen of the mandibular lesion.

Genetic instability occurs in the majority of young patients with colorectal cancer

Replication errors (RER) associated with genetic instability have been found in cancers of several different types and particularly in the tumours of patients with hereditary non-polyposis colorectal cancer (HNPCC). We have here determined the prevalence of such instability in relation to age among patients without HNPCC. Colorectal cancers (CRCs) in the majority of patients 35 years of age or younger exhibited instability (58% of 31 patients), whereas CRCs from patients older than 35 uncommonly did (12% of 158, p < 0.0001). Twelve of the patients under 35 with instability were evaluated for alterations of mismatch repair genes, and five were found to harbour germline mutations. These data suggest that the mechanisms underlying tumour development in young CRC patients differ from those in most older patients, regardless of HNPCC status. The results have important implications for genetic testing and management of young CRC patients and their families.

Suppression of hepatic gluconeogenesis in long-term Troglitazone treated diabetic KK and C57BL/KsJ-db/db mice

The orally effective antidiabetic agent Troglitazone (CS-045) exerts hypoglycemic effects in various insulin-resistant obese and/or diabetic animals. Since increased hepatic gluconeogenesis is a major cause of hyperglycemia in these diabetic animals, we evaluated the effect of long-term Troglitazone treatment on hepatic gluconeogenesis. Troglitazone was administered for 7 days to normal ddY mice, diabetic KK mice, diabetic C57BL/KsJ-db/db mice, and its heterozygote, db/+ mice, as a 0.1% or 0.2% food admixture. Troglitazone significantly decreased plasma glucose in diabetic KK and db/db mice, but not in normal ddY and db/+ mice. 14C incorporation into blood glucose from NaH14CO3 was measured to assess hepatic gluconeogenesis in diabetic KK and normal ddY mice. Hepatic gluconeogenesis was significantly increased in diabetic KK mice (P < .01) as compared with normal mice, and was significantly suppressed (P < .05) after 7 days of Troglitazone treatment (approximately 200 mg/kg/d). Glucose-6-phosphate (G6P) and fructose-6-phosphate (F6P) were significantly decreased but fructose-1,6-bisphosphate (FBP) was not significantly increased in the liver of diabetic db/db mice treated with Troglitazone for 7 days (approximately 80 mg/kg/d) as compared with control db/db mice. These changes in G6P, F6P, and FBP corresponded with the activity of fructose-1,6-bisphosphatase (Fru-1,6P2ase) and 6-phosphofructo-1-kinase (6-PF-1K), which determined the content of F6P and FBP. Namely, Fru-1,6P2ase was significantly decreased in Troglitazone-treated db/db mice as compared with control mice, whereas 6-PF-1K activity was not affected by Troglitazone treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Triangular flap repair of the congenital earlobe cleft

Repair of a congenital earlobe cleft was performed on 16 patients using a new surgical technique derived from the Tennison-Randall triangular flap operation for cheiloplasty. There were no complications. This method was applied because the deformities and desired outcomes in the congenital earlobe cleft are similar to those of the cleft lip. Many papers have described surgery for congenital and acquired clefts; the former differs from the latter in some respects. The techniques described for the repair of acquired clefts are not always appropriate for congenital clefts. In addition, some operations specifically designed for congenital clefts require more complicated techniques. Using our technique to correct lobule deformities with a triangular flap in proportion to the angle and extent of the cleft, a superior cosmetic result was obtained in the repair of longitudinal earlobe clefts.

[A case of primary mediastinal germ cell tumor, successfully treated with chemotherapy and curative resection]

A 20-year-old man was admitted to our hospital because of an abnormal shadow on chest X-ray Laboratory data revealed a high serum alpha-fetoprotein (AFP) and LDH level. Percutaneous needle biopsy of the tumor suggested primary mediastinal germ cell tumor. Curative resection was performed after three courses of combination chemotherapy (cis-platinum, VP-16, bleomycin and adriamycin). A post-operative histological examination of the mass revealed total necrosis. Post-operative course was uneventful, and he has been free of recurrence for the last six months.

Choledochal cysts: special emphasis on the usefulness of intraoperative endoscopy

Long-term complications after excisional surgery for choledochal cyst include stone formation within the intrahepatic bile duct (IHBD) and within the intrapancreatic portion of the bile duct (IPBD). The authors reviewed 180 patients with choledochal cysts (137 women) seen during a 30-year period and report their recent experience with intraoperative cyst endoscopy. Primary cyst excision with hepaticoenterostomy was performed in 150 cases, and a secondary cyst excision, after various lesser drainage procedures, in 24. Six children were treated early in the series with a cyst enterostomy. The mean age and follow-up period were 4.3 and 9.4 years, respectively. At surgery, dilatation of the IHBD was identified in 96 patients, and protein plugs or stones were observed in 31 common pancreaticobiliary channels. Fifty-five common channels were noted to be dilated. Hepaticojejunostomy was performed in 123 patients without intraoperative endoscopy. Late stone formation occurred within the IHBD in 4 of these cases and within residual segments of intrapancreatic cyst in 2 (mean age and follow-up period were 4.9 and 13.0 years, respectively). Intraoperative endoscopy was performed in 51 patients (mean age and follow-up period 3.6 and 4.3 years), and stone formation has not been observed in any patients in this group. Intraoperative cyst endoscopy is recommended as a valuable adjunct to choledochal cyst excision.

Cardiopulmonary function in bicycle racing over mountainous terrain at moderate altitude

To examine cardiopulmonary function during exercise in a mountainous region at moderate altitude, we measured cardiac frequency, oxygen consumption (VO2), and percentage arterial hemoglobin oxygen saturation (%SaO2) before and after a bicycle race with a starting point at 638 m and finishing point at 1980 m. The time required to ascend an elevation of 10 m was prolonged with increasing altitude, and heart rate also increased with altitude. The %SaO2 at the starting point and at the finishing point differed significantly (P < 0.01). Faster cyclists exhibited higher %SaO2 and lower VO2, while slower cyclists exhibited a reduction in %SaO2 and an increase in VO2 immediately after the race. The %SaO2 recovery time was significantly correlated with the racing time (r = 0.54, P < 0.001). Therefore, the faster cyclists' oxygen debt upon completion of the race may be small and recovery of cardiopulmonary function may be fast, while the slower cyclists' oxygen debt may be large and recovery of cardiopulmonary function may be slow.

[In vivo visualization of neurotransmitter function in the human brain by PET]

Measurement of cerebral blood flow and energy metabolism using PET with 15O and 18F labeled tracers allows quantitative evaluation of cerebral metabolism that can be perturbed in pathological states. Neurotransmission is a new target that is visualized by labeling of substrates of enzymes that are involved in neurotransmitter synthesis or degradation. Neuronal receptors are mapped by introducing the labeled ligands that are specifically bound to the receptors in question. We developed unique tracers that label dopamine D2 or histamine H1 receptors. With other available ligands for the muscarinic cholinergic receptors and [18F] fluorodopa, we started clinical investigations to document the state of neurotransmission in patients with epilepsy, Parkinson's disease and dementia. Using [11C] doxepin we observed an increase of H1 receptors in the epileptic foci that showed decreased glucose metabolic rate at the interictal phase. This phenomenon is compatible with reported increase of mu opiate receptors in the brains of epileptic patients. Brain uptake of FDOPA (Ki), calculated by the graphical plot was found relatively stable with age both in the normal population and dementia patients. However, the striatal Ki of FDOPA of severely demented patients significantly reduced, compared with the normal aged subjects. The correlation analysis between FDOPA Ki and severity of dementia as assessed by mini-mental state examination revealed a significant reduction of Ki associated with the disease progression. Increase in D2 receptor density as assessed by the uptake of YM 09151-2 was observed in cases with reduced FDOPA uptake, which may correspond to the state of supersensitivity of the D2 receptors.

[Evaluation of the residual functional reserve and the early regeneration after the hepatic resection using asialoglycoprotein receptor imaging agent]

99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA) is a newly developed liver imaging ligand which specifically binds to asialoglycoprotein receptor on the hepatic cell surface. We investigated whether 99mTc-GSA scintigraphy was able to be used as indexes for the residual functional reserve and the early regeneration of the hepatocyte after the hepatic resection. Four patients with metastatic liver cancer, 3 patients with hepatocellular carcinoma, and 1 patient with cholangiocellular carcinoma were studied. Basically, each patient was examined 4 times (before, 3, 10, 20 days after the operation). Immediately after i.v. injection of 185 MBq (3 mg) of 99mTc-GSA, serial images and dynamic data were obtained. Serial changes of HH15, as an index of blood clearance of the tracer calculated from the uptake ratio of heart at 15 minutes to that at 3 minutes, and LHL15, as an index of hepatic accumulation calculated from the uptake ratio of liver to liver plus heart at 15 minutes after the injection were analyzed before and after hepatectomy. Three out of 4 lobectomy patients which showed increased HH15, and decreased LHL15 as compared with the preoperative data were considered to be decreased residual hepatic functional reserve. The remaining one lobectomy patient showed increased HH15, but increased LHL15 inversely. One patient of two partial resections of hepatocellular carcinoma with liver cirrhosis demonstrated transiently decreased HH15, and increased LHL15. Two patients with metastatic liver cancer (one partial resection, six partial resections) showed decreased HH15, and increased LHL15. Postoperatively increased hepatic accumulation was presumed to be increased functioning hepatocyte or transiently increased asialoglycoprotein receptor on the cell surface by up-regulation. 99mTc-GSA scintigraphy might be helpful for non-invasive method to detect the residual functional reserve and the early regeneration of the hepatocyte after the hepatic resection.

[Enhanced delineation of the pancreatic duct in MR cholangiopancreatography (MRCP) with a combined use of secretin]

Magnetic resonance cholangiopancreatography (MRCP) is a method that can depict the main pancreatic duct non-invasively; however, its tendency to overestimate ductal stenosis is being noted. The authors used secretin to stimulate the output of pancreatic juice, which increased the signal of the main pancreatic duct and consequently minimized the occurrence of pseudostenosis artifacts in MRCP. MRCP images of 54 patients suspected of having pancreatic disease were visually evaluated by two observers before and after administration of secretin (1 clinical unit/kg). Improved delineation of the main pancreatic duct (68.5-59.3%, p < 0.05) and its side branches (40.7-29.6%, p < 0.05) was obtained with good interobserver agreement (kappa = 0.71-0.68).

Reactivity of the co-type and baa3-type cytochrome c oxidases from Pseudomonas aeruginosa with different endogenous cytochromes c

The reactivity between different cytochromes c purified from Pseudomonas aeruginosa cells grown aerobically in the absence of nitrate and isolated cytochromes co and baa3 was determined. The P. aeruginosa cytochrome co reacted most rapidly with the membrane-bound cytochrome c-551 among three c-type cytochromes analyzed, whereas the cytochrome baa3 reacted best with the membrane-bound cytochrome c-555. The results indicated that two terminal electron transfer systems are present in aerobic P. aeruginosa: one contains the cytochrome c-551 and cytochrome co, and the other contains the cytochrome c-555 and cytochrome baa3.

Alteration of [3H]hemicholinium-3 binding in the post-ischaemic gerbil brain

To determine whether presynaptic sites are resistant to cerebral ischaemia, we investigated the postischaemic alteration in [3H]hemicholinium-3 binding as a sensitive marker of presynaptic cholinergic terminals in the gerbil brain between 1 h and 7 days after recirculation using receptor autoradiography. Transient ischaemia was induced for 10 min. [3H]hemicholinium-3 binding was unchanged in the frontal cortex, striatum and hippocampus throughout the recirculation periods. Our histological study revealed conspicuous neuronal damage in the frontal cortex, striatum, hippocampal CA1 sector and hippocampal CA3 sector after ischaemia. The present study demonstrates that presynaptic sites in selectively vulnerable areas can maintain their structural components although postsynaptic neurones are clearly degenerated. Thus our findings support the hypothesis that presynaptic sites are particularly resistant to ischaemia, but postsynaptic sites are vulnerable.

Uptake site of lansoprazole, a proton pump inhibitor, in human fundic mucosa: possible relevance with fibroblast and Helicobacter pylori

To clarify the mechanism of the effect of lansoprazole in the healing of human gastric ulcer, the uptake sites of lansoprazole were studied using endoscopically biopsied specimens from the margin of the gastric ulcer. The specimens were incubated in a medium containing 3H-lansoprazole for 5 or 15 min., postfixed with 1% osmic acid and embedded in Epon. The semithin or ultrathin sections were made and radioautographic emulsion films were applied by the wire-loop method. 30 days after the incubation, the sections were developed, fixed and observed by light and electron microscopy. As a result, the uptake sites of lansoprazole were accumulated on the fibroblasts located near the tip portion of the gastric mucosa and on the unmyelinated nerve fibers as well as on the parietal cells. Some of the uptake sites were also observed near the plasma membrane of the bacteria in the gastric lumen. From these observations, lansoprazole uptake sites were not only on the parietal cells but on the fibroblasts and the bacteria, suggesting that the effect of lansoprazole was exerted partly through the influence on the mesenchymal cells and Helicobacter pylori-related organisms.

Characterization of a wild poliovirus type 3 isolated Japan in 1993

A wild poliovirus type 3 was isolated from a throat swab of a patient with upper respiratory symptoms without paralysis in Shiga Prefecture, in 1993. Wild poliovirus has never been isolated in these nine years in Japan. The most recent isolation of wild poliovirus was of type 1 in 1984 from a case of encephalomyelitis in Aichi Prefecture. Antigenic and PCR-restriction fragment length polymorphism analyses revealed that the Shiga strain was non-Sabin origin. Sequence analysis of the VP1 region confirmed that the isolate was a wild poliovirus type 3. Furthermore, this isolate had higher homology to the isolates from North Vietnam than those from Pakistan or Finland, suggesting that the Shiga strain was imported from Asian area. This strain was also shown to be neurovilurent in transgenic mice carrying human poliovirus receptor gene.