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Biomedical subjects

A Fukui

Publications and source records attributed to A Fukui.

At least 91 records · Page 5Linked to original sources
PubMed1994

Reproducibility of magnetic resonance spectroscopy in patients undergoing dialysis and evaluation of the therapeutic response of tumors.

RATIONALE AND OBJECTIVES: The reproducibility of repeated magnetic resonance (MR) spectroscopy was studied in patients undergoing dialysis and treatment of a variety of malignant tumors. METHODS: Localized MR spectra were obtained using a 1.5-T system by image-selected in vivo spectroscopy. Total metabolite signal was integrated between phosphomonoester and beta-adenosine triphosphate resonance. We termed this measurement AREA. RESULTS: Intrapatient variability was evaluated on repeated thigh muscle spectroscopy for 10 patients. Sequential spectra of 10 malignant tumors of the extremities were analyzed and compared with the histology of surgical specimens in seven patients. Intrapatient variability in AREA was calculated as 14.0%. The extent of necrosis and AREA ratio (definition: AREA post-therapy/AREA pretherapy) were as follows; 6.1% in > 90% necrosis, 43% in 50% to 90% necrosis, and 79% in < 50% necrosis. CONCLUSIONS: Localized MR spectra are fairly reproducible and may relate to treatment efficacy.

Adolescent↗
PubMed1994

Malignant lymphoma of the esophagus associated with macroglobulinemia: report of a case.

A case of non-Hodgkin's lymphoma of the esophagus in a 74 year old man is presented. Grossly, the surgically removed esophagus had a fusiform submucosal mass covered with smooth surfaced mucosa. Microscopic examination revealed that the mass consisted of a dense infiltrate of small to medium-sized lymphoid cells with plasmacytoid differentiation, leading to a diagnosis of diffuse small cell lymphoma with lymphoplasmacytic subtype. Laboratory data as well as immunohistochemical studies proved that the lymphoma produced monoclonal immunoglobulin M, giving rise to macroglobulinemia.

Aged↗
PubMed1994

To see or not to see: the debate over pornography and its relationship to sexual aggression.

The role played by pornography in the generation of thoughts, feelings, impulses and behaviours in its viewers has long been a topic of debate and controversy. The uncertainty about its potential effects on human behaviour, especially its relationship to sexual aggression, has stimulated the recent debate with the possibility of tighter censorship laws being implemented throughout this country. A review of the topic from a number of different perspectives fails to establish that pornography in its purely erotic form has any significant detrimental effect on human behaviour. More difficult to determine are its effects on psychological development. If behavioural disturbances do occur following exposure to such material, they occur in the context of an individual who shows more global disturbances of personality. The current debate regarding pornography provides an opportunity to address in a broader social context issues perhaps more significant for our society: the relationships between men and women, and the roles and recognition provided to each of the sexes.

Aggression↗
PubMed1994

Control of cell differentiation and morphogenesis in amphibian development.

We reviewed cell differentiation and morphogenesis by mesoderm-inducing factors during amphibian embryogenesis. Recently, two kinds of growth factors, activin and FGF, have been identified as influential candidates for natural mesoderm-inducing factor in amphibian development. These factors are present in early Xenopus embryos. In particular, activin has been shown to induce many kinds of mesodermal tissues in a dose-dependent manner. Activin-treated ectodermal sheet (animal cap) acts as an organizer causing gene expression, mesoderm formation and functional events such as secondary axis formation. Follistatin, an activin-specific binding protein, also present in the early Xenopus embryo, makes a complex with activin. Follistatin protein exerts no inducing activity of Xenopus animal cap. Endogenous follistatin may, however, play the role of an activin regulation factor. Endogenous actions of activin and FGF were studied using injection of their receptor mRNAs. Disruption of the FGF signaling pathway by its non-functional dominant negative receptors produced trunk and tail defects. In the case of activin, an embryo cannot form axial structures. Animal-half blastomeres from the late 8-cell stage Xenopus embryo respond to activin, and there are prepatterns in ventral and dorsal cells from very early stages. The timing of mesoderm induction during development and the relationship between the inducing factors and competent cells are discussed in this report. Differentiation of tissues and organized formation of organs can be understood as a system of serial inductive reactions originating from the organizer. We have attempted to construct a model of organizer formation based on the results of recent studies.

Activins↗
PubMed1993

"Plasmatic imbibition" in the rat musculocutaneous pedicled venous flap: enzymatic proof using horseradish peroxidase.

To determine the reason for survival of a pedicled venous flap in which only a draining vein is preserved, it is important to clarify what kind of blood flow is present in the preserved draining vein. Pedicled venous flaps were prepared on the dorsum of the rat and histologically evaluated using horseradish peroxidase (HRP). HRP was applied between the flap and recipient bed in one group. In the other group, HRP was injected into the femoral vein after the flap was turned over (to prevent contact with the recipient bed). The flaps in these HRP-treated groups were compared with untreated control groups. HRP applied between the flap and recipient bed was imbibed into the flap and subsequently transferred into the preserved draining vein. HRP that was injected into the femoral vein was also found in the draining vein of the flap. These results suggest that (1) plasmatic imbibition occurs in pedicled venous flaps; and (2) antegrade and retrograde blood flow are present in the draining vein.

Administration, Topical↗
PubMed1993

Vascular complications of vascularized composite tissue transfer: outcome and salvage techniques.

Two hundred fifty-two vascularized composite tissue transfers were performed from 1985 to 1992 at Nara Medical University Hospital. Free tissue transfers were performed in 185 patients and island tissue transfers in 67 patients. Of these, 39 flaps were reexplored because of vascular complications. On initial reexploration, vascular obstruction was found at the site of anastomosis or in the main vascular pedicle in 36 patients and in the perforating vessels to the monitor flap in three patients. Arterial thrombus occurred in 11 patients, venous thrombosis in 12, and both in nine. Twenty-five reexplored flaps were salvaged. Initially, heparin was administered systemically when vascular compromise was suspected intraoperatively or postoperatively. Recently, we have used a "continuous local heparinization" technique to minimize blood loss. This method has been used in 12 patients who underwent reexploration and in nine patients in whom vascular compromise was suspected. Nineteen flaps survived completely, and two flaps failed.

Adolescent↗
PubMed1993

Isolation and characterization of Xenopus follistatin and activins.

Xenopus follistatin and activins were purified from a Xenopus laevis cell line (XTC-F1) by four purification steps consisting of consecutive affinity chromatography on dextran sulfate-Sepharose and Sulfate Cellulofine, fast protein liquid chromatography gel permeation, and reverse-phase high performance liquid chromatography (HPLC). Our results thus obtained indicated that almost equimolar amounts of activins A, AB, and B were found to be present as a complex with follistatin (activin-binding protein) in the conditioned medium of XTC-F1 cells. Reverse-phase HPLC of the complex gave Xenopus follistatin and activins A, AB, and B. The purified Xenopus follistatin showed four major bands in a molecular mass range from 34 to 39 kDa by SDS-polyacrylamide gel electrophoresis under nonreducing conditions. The ability of each form of the protein to specifically bind activin was determined by activin-binding assay and ligand blotting analysis. Each protein was found to have the same NH2-terminus and its sequence was very homologous to that of mammalian follistatin. Several criteria including immunoblotting analysis and various functional assays revealed the existence of three isoforms of activins A, AB, and B in Xenopus, as in mammals. Xenopus activins significantly induced both ventral and dorsal mesoderm in explants of Xenopus blastula cells that would otherwise form epidermis. In a dose-dependent manner of each isoform of activin, the induced explants were able to differentiate into blood-like cells, coelomic epithelium, mesenchyme, muscle, and notochord. The induction patterns of three Xenopus activins were essentially the same. The mesoderm induction by the purified Xenopus activins was shown to be inhibited stoichiometrically by the purified Xenopus follistatin. These results indicate that Xenopus XTC-F1 cells secrete several molecular forms of follistatin/activin-binding protein and three isoforms of activins AB and B in addition to activin A.

Activins↗
PubMed1993

An autopsy case of intracranial hemorrhage during tissue plasminogen activator infusion.

We describe an autopsy case of severe intracranial hemorrhage which occurred during the infusion of tissue plasminogen activator (t-PA) for acute myocardial infarction. A 75-year-old man was admitted with substernal chest pain of 3-h duration and electrocardiographic changes consistent with an acute inferior myocardial infarction. Physical examination was unremarkable, except for an initial blood pressure reading of 160/96 mmHg. The patient received 3,000 IU intravenous heparin followed by a 2.4 x 10(6) IU bolus dose of tissue plasminogen activator (t-PA) (Alteplase). This was followed by a drip infusion of 21.6 x 10(6) IU of t-PA over 1 h (total dose 41 mg). Thirty minutes after the infusion of t-PA was initiated, the patient suddenly lost consciousness and began to have violent convulsions, followed by cardiac arrest. Autopsy revealed massive hemorrhage in the bilateral cerebrum and brain stem. To our knowledge, this is the first case of sudden death during t-PA infusion therapy.

Aged↗
PubMed1993

Changes in circulating blood volume following isoflurane or sevoflurane anesthesia.

Changes of circulating blood volume (CB volume) measured by the dual indicator dilution method were observed in 33 chronically instrumented mongrel dogs following either alpha-chloralose-urethane (C group), additive isoflurane (I group) or sevoflurane anesthesia (S group). These anesthetic groups were each divided into two subgroups with regard to respiratory care, namely Cp, Ip and Sp for those with intermittent positive pressure ventilation (six animals per subgroups), and Cs, Is and Ss for those with spontaneous breathing (five animals per subgroups). The CB volume under positive pressure ventilation remained unchanged in the Ip and Sp groups at both 0.5 and 1.0 MAC, and in the Cp group. The CB volume remained essentially unchanged in the Cs and Is groups at both 0.5 or 1.0 MAC, but the plasma volume tended to increase slightly in the Is group at 1.0 MAC. In the Ss group under spontaneous breathing, however, the CB volume increased from 84.4 +/- 7.0 to 91.4 +/- 7.7 at 0.5 MAC, and to 91.4 +/- 10.2 ml.kg(-1) at 1.0 MAC (0.01 < P < 0.05). These increases were caused by an increase in the plasma volume. The above data suggests that a concomitant increase in the venous pressure associated with an increase in the intrathoracic pressure produced by positive pressure ventilation would attenuate changes in the CB volume during sevoflurane anesthesia.

Journal Article↗
PubMed1993

The arterialised venous flap: experimental studies and a clinical case.

It is accepted that small arterialised venous flaps (AVF) can survive on a recipient bed with poor blood supply but survival of larger flaps is not always satisfactory. Possible reasons for this include the flap anatomy, particularly the pattern of the venous network, or factors at the recipient site. To investigate the possible factors in the flap design and the recipient site of an arterialised venous flap, we studied the relationship between (1) size of the artery used to arterialise the flap at the recipient site and the survival rate and (2) the number of draining veins and the survival rate, using rabbit ear skin flap models. Our results suggest that AVFs may become necrotic in the presence of a relative excess of arterial blood inflow, and that two exit veins are more effective than one. We also report a case where a 10 x 15 cm sized free AVF harvested from the lower extremity survived on the forearm.

Adult↗
PubMed1993

The pedicled venous flap. Clinical applications.

Experimental findings of survival of pedicled venous flaps were clinically applied in seven cases for traumatic skin defects on digits. Five flaps which were transferred to or on digits other than the thumb survived, but two flaps from the index to the thumb developed partial necrosis. In order to prevent flap necrosis, the draining vein should be short.

Adult↗
PubMed1993

The pedicled venous flap. An experimental study.

Musculocutaneous pedicled venous flaps on the dorsum of rats survived at a statistically significantly higher rate than musculocutaneous composite grafts (p < 0.01). With a Silastic sheet (Dow Corning) beneath, both composite grafts and pedicled venous flaps necrosed. When a Silastic sheet with holes in it to allow some revascularisation from the bed was placed beneath, the survival rate was significantly better than with a complete Silastic sheet (p < 0.01). These results demonstrate that pedicled venous flap survival depends both on the draining vein, and revascularisation from the underlying bed.

Animals↗
PubMed1993

Non-radioactive coloured microsphere measurement of regional tissue blood flow for axial pattern flaps in rabbits.

We administered non-radioactive coloured microspheres (NRACM) to measure the regional tissue blood flow (RTBF) of eight axial pattern flaps and four kidneys in four rabbits using four repeated injections into each animal. As a control, we used radioactive microspheres (RAM) for six kidneys in three rabbits. There were no significant differences for RTBF values between NRACM and RAM, between the numbers of microspheres used (2 x 10(6) and 4 x 10(6)), or between the number of injections. These results showed that NRACM is a useful and safe laboratory method.

Animals↗
PubMed1993

Blood flow through prefabricated flaps--an experimental study in rabbits.

Prefabricated flaps were created by femoral vessel implantation beneath the abdominal skin in rabbits. The area of survival and blood flow through the prefabricated flap were measured after 1, 2, 4, 6, 8, and 12-week intervals. The parameters at 6, 8 and 12-week intervals were significantly larger than those for random pattern flaps (p < 0.01), but were significantly smaller than those for axial pattern flaps (p < 0.01). The minimum interval at which the prefabricated flap could be transferred successfully was between 6 and 8 weeks in this model. Microangiography demonstrated that neovascularisation began at the distal end of the implanted vascular bundle and spread throughout the flap by 8 weeks.

Abdominal Muscles↗
PubMed1993

[A stick type filter unit for prevention of biohazard in a research laboratory].

It is important to prevent unexpected laboratory infections in a biosafety area. It is recommended that extreme caution should be used when handling needles and syringes to avoid autoinoculation, and that needles and syringes should be used only when there is no alternative. To remove cells and cell debris, a disk-type microfilter unit, which is recommended using a needle, has been used for filtrating supernatant from HIV-1-infected cell cultures. We compared a stick-type microfilter unit, which can be used without a needle, with a disk-type one for their safety and recovery of human immunodeficiency virus particle after filtration. To confirm the right of our comparison, we observed the filter electron microscopically for the virus particles and virus suspensions were carried out and discussed. In conclusion, the stick-type filter should be improved, since the filter unit is inferior to the disk-type filter unit in purification of the virus, but for the safety is superior to the disk-type.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Resetting of regional preload due to ventricular shape change alters diastolic and systolic performance.

The diastolic and systolic pressure of one ventricle is increased by an increase in volume and/or pressure of the opposite ventricle; however, a mechanism for the ventricular interaction remains unclear. We hypothesized that the shape change of one ventricle elicited by the opposite ventricle would lead to resetting of the regional length, which may explain the ventricular interaction. We used 15 cross-circulated isovolumically contracting canine hearts in which both ventricular volumes were independently controlled. Diastolic regional segment area was calculated by multiplying circumferential and longitudinal lengths on right ventricular free wall (RVFW; n = 6), interventricular septum (IVS; n = 11), and left ventricular (LV) FW (n = 12). The regional area at relatively small volumes of both ventricles were expressed as 100%. With constant RV volume, increasing LV from 7 to 19 ml increased RV diastolic and systolic pressures by 2.7 and 5.5 mmHg, respectively. Conversely, increasing RV volume increased LV diastolic and systolic pressures by 2.3 and 7.5 mmHg, respectively. Increasing LV volume increased RVFW regional area from 121.0 to 124.6% (P < 0.01) and increased IVS regional area from 103.3 to 108.7% (P < 0.01), whereas the RV volume was held constant. Increasing RV volume also increased LVFW and IVS regional areas from 109.9 to 111.6% (P < 0.01) and from 106.8 to 108.9% (P < 0.05), respectively. Ventricular shape change elicited by ventricular interaction will increase the regional wall area, even though the volume of the chamber is unchanged. The increase in the regional area alters the position of the tissue on its resting and active length-tension relations and, thus, leads to enhancement of the chamber pressure.

Animals↗
PubMed1993

PC-766B, a new macrolide antibiotic produced by Nocardia brasiliensis. II. Isolation, physico-chemical properties and structure elucidation.

A new macrolide antibiotic, PC-766B, was isolated from the cells of Nocardia brasiliensis SC-4710 by acetone extraction, and purified by gel filtration, silica gel chromatography, HPLC and TLC. The structure of PC-766B was determined by NMR spectral analysis to be a new class of the hygrolidin family antibiotics. PC-766B had a 16-membered macrocyclic lactone ring, a 6-membered hemiketal ring and a 2-deoxy-D-rhamnose moiety. DL-alpha-Tocopherol, known as an antioxidant agent, significantly improved the stability of PC-766B and prevented the decomposition of PC-766B during the storage of the antibiotic.

Anti-Bacterial Agents↗