Biomedical subjects

S Fukuoka

Publications and source records attributed to S Fukuoka.

At least 19 recordsLinked to original sources

PubMed2004

GP2/THP gene family of self-binding, GPI-anchored proteins forms a cluster at chromosome 7F1 region in mouse genome.

We investigated the genomic organization of pancreatic zymogen granule membrane-associated protein GP2, a GPI-anchored protein exhibiting self-aggregation at acidic pH, in order to construct a gene-knockout mouse. Cloning and analysis of lambda clones encoding GP2 from 129 Svj mouse genomic DNA libraries showed that the GP2 gene spans about 16.8 kb and includes 11 exons. Identifiable functional domains including a signal sequence, an EGF-like motif, a putative condensing ZP domain, a GPI-anchor attachment site, and a transmembrane sequence for GPI anchoring are encoded in separate exons. Using FISH, the GP2 gene was mapped to mouse chromosome 7F1 near the gene for THP, a GP2 homolog expressed in the cells of thick ascending loop of Henle (TALH) in the kidney. Further analysis of the mouse genome revealed that the THP and GP2 genes are adjacent to one another and are separated by only 3.5 kb in the 7F1 locus. Additionally, the overall structure of the THP gene, 16.2kb with 11 exons, was strikingly similar to that of GP2. This finding suggests that the GP2 and THP genes were generated by gene duplication and evolved separately to acquire regulatory elements leading to tissue-specific expression. Comparative analysis revealed that the 5' flanking region of the THP gene is similar to the first intron of NKCC2, a TALH cell-specific ion-transporter gene. The promoter region of the GP2 gene shares cis-elements found in other pancreas-specific genes. Using this genetic information, a GP2 null mutation was successfully introduced into an ES cell line, and an animal model was established without disruption of THP expression.

Animals↗

PubMed2004

Development of cholinergic chronotropic control in chick (Gallus gallus domesticus) embryos.

In chick (Gallus gallus domesticus) embryos, instantaneous heart rate begins to fluctuate with the appearance of rapid, transient decelerations at around the end of the second week of incubation. Previously, it was shown that instantaneous heart rate decelerations were eliminated by administration of atropine and concurrently heart rate baseline was elevated in late embryos. Because the previous study lacked statistical treatment and there has been recent controversy over the development of tonic vagal control of the heart, we reexamine the hypothesis that transient decelerations of instantaneous heart rate are mediated by vagus nerve and the vagal tone begins to appear at around the end of the second week of incubation. Atropine administration tests were conducted for sixty-seven 11- to 14-day-old and 18-day-old embryos in total. Heart rate decelerations appeared sporadically in three out of ten 12-day-old embryos, but the difference of mode heart rate before and after administration of atropine was not significant. Seven out of nine 13-day-old embryos and all nine 14-day-old embryos showed heart rate decelerations and the difference of mode heart rate before and after atropine administration was significant. In late (18-day-old) embryos, magnitude and frequency of instantaneous heart rate decelerations further increased with additional appearance of transient, irregular accelerations. Administration of varying doses of atropine completely eliminated the heart rate decelerations and elevated the heart rate baseline more markedly than in young embryos, indicating the maturation of vagal tone late in incubation.

Animals↗

PubMed2002

Feasibility of myocardial dual-isotope perfusion imaging combined with gated single photon emission tomography for assessing coronary artery disease.

The clinical feasibility of both dual-isotope single photon emission tomography (SPET) and gated SPET have been described. The present study evaluates the feasibility of combining gated SPET with exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET corrected for scatter. Ninety-one patients with known or suspected coronary artery disease underwent cardiac catheterization and coronary angiography. Twenty-nine of them underwent exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET with a second 201Tl injection 3 h after the initial 201Tl injection (protocol 1). We then segregated a Bull's eye polar map into three coronary artery territories and quantified the relative regional uptake. The remaining 62 patients underwent exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET combined with gated SPET. We visually evaluated exercise and rest images from the three coronary artery territories. Left ventricular (LV) function was assessed globally by means of the LV ejection fraction and regionally by means of visual scoring analysis, compared with left ventriculography (LVG). The correlation between rest 99mTc-tetrofosmin and 201Tl reinjection images in 87 areas of coronary artery territory (r=0.89, P<0.01) and in 13 infarcted areas (r =0.94, P<0.01) was very close in protocol 1. The overall values for vessel-related sensitivity, specificity and accuracy were 88%, 79% and 82%, respectively, in protocol 2. The correlation between gated SPET and LVG was significant and linear with respect to the LV ejection fraction (r=0.77, P<0.01). The wall motion score from visual evaluation in gated SPET revealed a close overall agreement with LVG (concordance rate, 88%; kappa, 0.670). Exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET with scatter correction for assessing the coronary artery disease offers excellent diagnostic accuracy and the additional gated SPET provides useful information about LV function similar to that for LVG. This sequential protocol requires only 2 h to generate much useful clinical information.

Aged↗

PubMed2001

Analysis of the C-terminal structure of urinary Tamm-Horsfall protein reveals that the release of the glycosyl phosphatidylinositol-anchored counterpart from the kidney occurs by phenylalanine-specific proteolysis.

Tamm-Horsfall protein (THP), also known as uromodulin, is a major glycoprotein synthesized in the kidney. THP is expressed on the luminal surface of the membrane with the glycosyl phosphatidylinositol (GPI) anchor and excreted in urine at a rate of 50-100 mg per day. Although THP is the most abundant urinary protein, the function of THP remains unclear. In addition, little is known about the mechanism by which large amounts of THP are actively released into the urinary fluid. In this study, we examined the C-terminal structure of highly purified THP derived from human urine. Carboxypeptidase Y efficiently degraded urinary THP, indicating that the C-terminal structure of the protein contains an amino acid residue with a free carboxyl moiety. These results are consistent with our previous finding that urinary THP does not bind anti-CRD antibody. We obtained peptides from the complete digestion of urinary THP with lysylendopeptidase. We purified the most C-terminal peptide with p-phenylene diisothiocyanate-controlled pore glass (DITC-CPG) beads. N-terminal sequence analysis indicated the peptide begins with Tyr 520 and ends between E539 and E576. Direct C-terminal amino acid sequencing of highly purified urinary THP gave a sequence of -X-(Q)-G-(R)-F, corresponding to amino acids 544-548, -S-Q-G-R-F. We therefore conclude that urinary THP is generated by a proteolytic cleavage between F548 and S549, 66 amino acids upstream of a possible GPI-anchor attachment site. Because the sequence of THP, including the cleavage site, is highly homologous to that of GP2, a GPI-anchored protein within the pancreas, and both THP and GP2 are abundantly found as soluble forms in the excreted fluids, a common mechanism may exist governing the proteolytic release of GPI-anchored membrane proteins.

Amino Acid Sequence↗

PubMed2001

Conditions for solubilization of Tamm-Horsfall protein/uromodulin in human urine and establishment of a sensitive and accurate enzyme-linked immunosorbent assay (ELISA) method.

Tamm-Horsfall protein (THP), also referred to as uromodulin, is a major glycoprotein produced by kidney cells. The level of THP in urine is an indicator of renal function. THP levels are difficult to quantify accurately, because the protein forms aggregates in the pH and ion concentrations found in urine. Here, we describe conditions by which THP can be solubilized and kept soluble during measurement using Triton X-100, EDTA, and alkaline pH. Establishing conditions for precise quantification of THP by enzyme-linked immunosorbent assay (ELISA) will aid in studying the functions of THP.

Animals↗

PubMed2001

Physico-chemical analysis of lipid A fractions of lipopolysaccharide from Erwinia carotovora in relation to bioactivity.

Highly purified bisphosphoryl, monophosphoryl and dephosphoryl lipids A from Erwinia carotovora with different acylation patterns were characterized physico-chemically. Applying matrix assisted laser desorption/ionization mass spectrometry, the purity of the lipid A fractions was determined, and from monolayer measurements the molecular space requirement was estimated. Fourier transform infrared spectroscopy allowed the elucidation of the gel to liquid crystalline phase transition of the acyl chains as well as the determination of the tilt angle of the diglucosamine backbone with respect to the acyl chain direction applying dichroitic measurements with attenuated total reflectance. With synchrotron radiation small-angle X-ray diffraction the supramolecular aggregate structure was determined, and with fluorescence resonance energy transfer spectroscopy the lipopolysaccharide binding protein induced intercalation of lipid A into a phospholipid matrix corresponding to that of the macrophage membrane was investigated. From the results, a clear dependence of the physico-chemical parameters on the particular lipid A structure can be followed. Furthermore, these parameters correlate well with the biological activities of the various lipids A as deduced from their ability to induce biological activity (Limulus assay and cytokine induction in mononuclear cells). These results contribute to a closer interpretation of the physico-chemical prerequisites for endotoxic activity as found for enterobacterial lipid A.

Air↗

PubMed2001

Gamma knife radiosurgery for growth hormone-secreting pituitary adenomas invading the cavernous sinus.

The authors assessed whether gamma knife radiosurgery is effective for patients with acromegaly where the pituitary tumors invaded the cavernous sinus. Radiosurgery was performed on 9 patients (average of 20 Gy to the tumor margin), 8 of whom had already undergone transsphenoidal surgery and/or craniotomy with occasional medication of octreotide to reduce tumor size as well as hormonal levels. All tumors have been well controlled so far with follow-up periods ranging from 12 to 69 months (mean: 42). No complications occurred. Forty percent of the patients showed hormonal normalization at 2 years, with the median being 31 months. Similarly, 50% of the patients demonstrated normalization of GH and IGF-I at 36 months. We conclude that gamma knife radiosurgery is a safe and effective tool to treat these tumors invading the cavernous sinus.

Adenoma↗

PubMed2001

Acute necrotizing eosinophilic myocarditis successfully treated by high dose methylprednisolone.

Acute necrotizing eosinophilic myocarditis is the most severe form of eosinophilic myocarditis, or hypersensitivity myocarditis, and is characterized by rapidly progressive congestive heart failure followed by fulminant clinical deterioration that is nearly always fatal. A 55-year-old previously healthy patient with acute necrotizing eosinophilic myocarditis was diagnosed by early myocardial biopsy and successfully treated with corticosteroids. Throughout his hospitalization, the eosinophil count in the peripheral blood remained normal (56-201/mm3). Early stage corticosteroid therapy can have dramatic effects in acute necrotizing eosinophilic myocarditis and early diagnosis by endomyocardial biopsy is recommended.

Acute Disease↗

PubMed2001

Biophysical characterization of lipopolysaccharide and lipid A inactivation by lactoferrin.

The interaction of bacterial endotoxins (LPS Re and lipid A, the 'endotoxic principle' of LPS) with the endogenous antibiotic lactoferrin (LF) was investigated using various physical techniques and biological assays. By applying Fourier-transform infrared (FTIR) spectroscopy, we find that LF binds to the phosphate group within the lipid A part and induces a rigidification of the acyl chains of LPS. The secondary structure of the protein - as monitored by the amide I band - is, however, not changed. Concomitant with the IR data, scanning calorimetric data indicate a sharpening of the acyl chain phase transition. From titration calorimetric and zeta potential data, saturation of LF binding to LPS was found to lie at a [LF]:[LPS] ratio of 1:3 to 1:5 M from the former and 1:10 M from the latter technique. X-ray scattering data indicate a change of the lipid A aggregate structure from inverted cubic to multilamellar, and with fluorescence (FRET) spectroscopy, LF is shown to intercalate by itself into phospholipid liposomes and may also block the lipopolysaccharide-binding protein (LBP)-induced intercalation of LPS. The LPS-induced cytokine production of human mononuclear cells exhibits a decrease due to LF binding, whereas the coagulation of amebocyte lysate in the Limulus test exhibited concentration-dependent changes. Based on these results, a model for the mechanisms of endotoxin inactivation by LF is proposed.

Animals↗

PubMed2001

A new extraction method for Acinetobacter species ODB-L2 rough form lipopolysaccharide from culture broth.

The Gram-negative bacterium Acinetobacter species ODB-L2 produces lipopolysaccharide (LPS) in culture broth. The LPS could not be purified by conventional extraction methods using 90% phenol/water or 90% phenol/chloroform/petroleum ether mixed solvent. Extraction was achieved employing an admixture of chloroform, ethanol, and 4 M HCI solution. The LPS was purified from dissolving the crude extracts in 90% phenol and LPS sediment formed by addition of methanol. The LPS was characterized by chemical, biochemical, and physicochemical methods as rough form 3-hydroxydodecanoic acid rich LPS.

Acinetobacter↗

PubMed2000

Molecular cloning and sequences of cDNAs encoding alpha (large) and beta (small) isoforms of human pancreatic zymogen granule membrane-associated protein GP2.

cDNA clones encoding two different (alpha and beta) forms of human pancreatic zymogen granule membrane-associated protein glycoprotein 2 (GP2) (also referred to as ZAP75), a critical component in regulated membrane trafficking along the apical secretory pathway in pancreatic acinar cells, have been isolated. Structural analysis of the clones revealed that the alpha and beta forms of GP2 consist of 527 and 380 amino acid (aa) residues, respectively. The beta form lacks a 147 aa domain that corresponds to the 25-171 region of the alpha form, suggesting that it is a product of an alternative splicing event. Expression of both forms of GP2 in the human pancreas was confirmed. A unique isoform of GP2 is reported for the first time in humans.

Amino Acid Sequence↗

PubMed2000

Effect of long-term atrial-demand ventricular pacing on cardiac sympathetic activity.

It has been shown that either dual-chamber or atrial pacing may be better than ventricular single-chamber pacing, but the long-term effect of dual-chamber pacing on cardiac sympathetic activity is unclear. The aim of this study was to assess the effect of long-term dual-chamber pacing on cardiac sympathetic activity, compared with atrial pacing and unpaced individuals. We studied 11 patients with dual-chamber pacemakers (Group D), nine with atrial single-chamber pacemakers (Group A) over the long term (mean 44 +/- 36 months) and 10 normal individuals without cardiac pacing. All underwent myocardial 123I-metaiodobenzylguanidine (MIBG) imaging to assess cardiac sympathetic activity. The heart-to-mediastinum (H/M) MIBG uptake ratio and the MIBG washout rate from the myocardium were calculated. Echocardiography was performed in all patients with cardiac pacing to assess left ventricular function. In Group D, the H/M ratio on delayed images was significantly lower than that of Group A (1.82 +/- 0.51 vs 2.56 +/- 0.50, P < 0.001) and normal individuals (2.65 +/- 0.35, P < 0.05). The myocardial MIBG washout rate of Group D was significantly higher than that of either Group A (52 +/- 13% vs 36 +/- 8%, P < 0.01) or normal individuals (31 +/- 7%, P < 0.05). Neither the H/M ratio nor MIBG washout rate differed significantly between patients in Group A and normal individuals. Furthermore, the echocardiographic parameters did not differ significantly between the two pacing groups. We conclude that long-term ventricular pacing, even in the presence of atrioventricular synchrony, accelerates cardiac sympathetic activity without deteriorating left ventricular function.

3-Iodobenzylguanidine↗

PubMed2000

A novel spore peptidoglycan hydrolase of Bacillus cereus: biochemical characterization and nucleotide sequence of the corresponding gene, sleL.

The exudate of germinated spores of B. cereus IFO 13597 in 0.15 M KCl-50 mM potassium phosphate (pH 7.0) contained a spore-lytic enzyme which has substrate specificity for fragmented spore cortex from wild-type organisms (cortical-fragment-lytic enzyme [CFLE]), in addition to a previously characterized germination-specific hydrolase which acts on intact spore cortex (spore cortex-lytic enzyme [SCLE]) (R. Moriyama, S. Kudoh, S. Miyata, S. Nonobe, A. Hattori, and S. Makino, J. Bacteriol. 178:5330-5332, 1996). CFLE was not capable of degrading isolated cortical fragments from spores of Bacillus subtilis ADD1, which lacks muramic acid delta-lactam. This suggests that CFLE cooperates with SCLE in cortex hydrolysis during germination. CFLE was purified in an active form and identified as a 48-kDa protein which functions as an N-acetylglucosaminidase. Immunochemical studies suggested that the mature enzyme is localized on a rather peripheral region of the dormant spore, probably the exterior of the cortex layer. A gene encoding the enzyme, sleL, was cloned in Escherichia coli, and the nucleotide sequence was determined. The gene encodes a protein of 430 amino acids with a deduced molecular weight of 48,136. The N-terminal region contains a repeated motif common to several peptidoglycan binding proteins. Inspection of the data banks showed no similarity of CFLE with N-acetylglucosaminidases found so far, suggesting that CFLE is a novel type of N-acetylglucosaminidase. The B. subtilis genome sequence contains genes, yaaH and ydhD, which encode putative proteins showing similarity to SleL.

Amino Acid Sequence↗

PubMed2000

Combination chemotherapy of cisplatin, ifosfamide, and irinotecan with rhG-CSF support in patients with brain metastases from non-small cell lung cancer.

BACKGROUND: Brain metastases develop frequently in patients with non-small cell lung cancer (NSCLC), and the prognosis for these patients is very poor. We evaluated the role of chemotherapy for patients with brain metastases from NSCLC. METHODS: We analyzed 30 patients who were discovered to have brain metastases during the diagnosis of 121 patients enrolled in three consecutive clinical trials on advanced NSCLC assessing combination chemotherapy of cisplatin, ifosfamide and irinotecan with rhG-CSF support. Response in the brain lesions was evaluated by contrast-enhanced MRI scans after at least two courses. RESULTS: Fourteen patients achieved a partial response (PR) but there was no change (NC) in 13 patients and progressive disease (PD) in 1. Among patients with extracranial lesions, 18 had a PR and 11 had NC. The response rate in brain metastases was 50.0%, and that in extracranial primary and metastatic lesions was 62.1%. The median duration of response for intra- and extracranial lesions was 140 and 147 days, respectively. After completing chemotherapy, Gamma Knife radiosurgery was performed on 2 patients in remission and 8 patients at disease progression. The median survival time and 1-year survival rate were 382 days and 56.1%, respectively. CONCLUSIONS: Both the response rate and survival data in this retrospective study suggest a high degree of activity of this combination chemotherapy in patients with brain metastases from NSCLC.

Adult↗

PubMed2000

Estimation of the migration of tibial components in total knee arthroplasty. A roentgen stereophotogrammetric analysis.

Accurate quantitative measurements of micromovement immediately after operation would be a reliable indicator of the stability of an individual component. We have therefore developed a system for measuring micromovement of the tibial component using three non-contact displacement transducers attached to the tibial cortex during total knee arthroplasty (TKA). Using this system we measured the initial stability in 31 uncemented TKAs. All the tibial components were fixed by a stem and four screws. The initial stability was defined as the amount of displacement when a load of 20 kg was applied. The mean subsidence was 60.7 microm and the mean lift-off was 103.3 microm. We also studied the migration of the tibial component using roentgen stereophotogrammetric analysis (RSA) for up to two years after operation. Most migration occurred during the first six months, after which all prostheses remained stable. We defined migration as the maximum total point motion (MTPM) at two years after operation. The mean migration was 1.29 mm at two years. Our results show that there was a significant correlation between the initial stability and migration (p < 0.05) and emphasise the importance of the initial stability of the tibial component.

Aged↗

PubMed2000

Cavernous sinus hemangioma treated with gamma knife radiosurgery: usefulness of SPECT for diagnosis--case report.

A 79-year-old female presented with cavernous sinus hemangioma manifesting as double vision due to right oculomotor and trochlear nerve pareses. Computed tomography and magnetic resonance imaging revealed bony erosion and a right cavernous sinus tumor with "tail sign" after contrast medium administration. Thallium-201 (201Tl) single photon emission computed tomography (SPECT) showed low uptake within the tumor, and technetium-99m-human serum albumin-diethylenetriaminepenta-acetic acid SPECT disclosed high uptake within the tumor. 201Tl SPECT usually shows very high uptake in meningiomas and malignant tumors, so the tumor was considered to be an unrelated benign tumor. The patient underwent partial resection of the tumor. Histological examination of the specimen confirmed cavernous hemangioma. The oculomotor nerve paresis partially improved. Gamma knife radiosurgery was carried out 4 months after the operation. The tumor markedly shrank with full recovery of extraocular movement 6 months after radiosurgery. SPECT is useful for distinguishing cavernous sinus hemangiomas from other cavernous tumors. Radiosurgery should be performed after partial resection or biopsy for cavernous sinus hemangiomas and may be the initial treatment for patients with small cavernous sinus hemangioma if the diagnosis can be established based on neuroimaging.

Aged↗

PubMed1999

Evaluation of blood flow within the subchondral bone of the femoral head: use of the laser speckle method at surgery for osteonecrosis.

The laser speckle method is a new form of tissue flowmetry that can analyze the interference pattern that appears when tissue is illuminated with a laser beam. During surgery for 100 cases of osteonecrosis of the femoral head, we measured the blood flow within the subchondral bone using this method. We compared the flow maps (two-dimensional distribution of the microcirculation) obtained this way with the necrotic area estimated by the preoperative magnetic resonance images and with the collapse seen during surgery. The laser speckle method was able to distinguish between the ischemic areas and the normal areas in 92 femoral heads, including five hips for which neither the magnetic resonance images nor the collapse observed during surgery demonstrated a distinct margin surrounding the necrotic area. We concluded that the laser speckle method is useful for defining the margin around a necrotic area.

Adult↗

PubMed1999

Assessment of subchondral bone blood flow in the rabbit femoral condyle using the laser speckle method.

The laser speckle method is a new form of flowmetry that can obtain a two-dimensional distribution of blood flow in tissue. This method is a noncontact, simple, and rapid technique that may aid in the diagnosis of osteonecrosis. We investigated whether the subchondral bone blood flow within the femoral condyles of rabbits could be measured by the laser speckle method. The hydrogen washout method was chosen as a comparison technique because of its ability to allow repetitive measurements of blood flow in various conditions in one rabbit and because of its reliability, which already has been established. We simultaneously measured the bone blood flow in 20 femoral condyles of 10 rabbits with the laser speckle and hydrogen washout methods and found a significant correlation between the blood flow levels with use of these two methods. For the clinical application of the laser speckle method, we also investigated the influence of cartilage thickness on the measurements and the depth in the bone to which blood flow could be measured with this method. A cartilage thickness of 0.2 mm did not influence the measurement of the bone blood flow, and the depth in the bone to which the laser speckle method could be used was approximately 2 mm.

Animals↗