Biomedical subjects
Publications and source records attributed to H Hirose.
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The effect of sera from calves stressed due to cortisol administration was investigated on cytochrome c (CytC) reduction, chemotaxis and random migration under agarose of bovine neutrophils. CytC reduction was significantly suppressed by the sera, whereas the other two function indicators were unaffected. The serum suppressive factor(s) of CytC reduction remained unidentified following analysis using ultrafiltration and sodium dodecyl sulphate-polyacrylamide gel electrophoresis.
Sera from calves which had been transported for 48 h resulted in impaired mitogen-stimulated blastogenesis of bovine lymphocytes and cytochrome c reduction activity of bovine alveolar macrophages. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis revealed the appearance of 33 kDa and 20 kDa proteins in most of the sera after transportation. The proteins could have been related to the serum suppression.
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Histological examination of gonads as well as chemical analysis of organotin compounds in tissues of the giant abalone, Haliotis madaka, was conducted to evaluate possible endocrine disruption and to consider the causal factors for the decline of abalone stocks in Japan. Abalone specimens were collected from two different areas, Tsushima as a reference site and Jogashima as a site representative of declining abalone populations, each month from September 1995 to November 1996. Scores were given to the development stages of reproductive cells in the ovary and testis. The degree of sexual maturation was evaluated by calculating the mean value of a histogram of these scores for the reproductive cells of each abalone. The temporal variations in degree of sexual maturation showed that female and male abalone from Tsushima matured synchronously, while those from Jogashima did not. The observed maximum reproductive developmental score in abalone from Jogashima was much lower than that from Tsushima, because immature females were present at the former site throughout the spawing season. Approximately 20% of the abalone from Jogashima were masculinized females with an ovo-testis. The masculinization of female abalone was similar to the imposex, typically induced in other gastropod molluscs by tributyltin (TBT) and triphenyltin (TPhT) from antifouling paints. Concentrations of TBT and TPhT in the muscles of abalone from Jogashima (n = 83) of 4.9 +/- 4.4 ng/g wet wt and 6.3 +/- 6.6 ng/g wet wt, respectively, were significantly higher than those from Tsushima (n = 125) (P < 0.01) of 0.8 +/- 0.8 ng/g wet wt and 0.6 +/- 1.3 ng/g wet wt, respectively. In situ exposure of abalone from Tsushima caged near a dockyard in Jogashima for 7 months (from the immature to the mature stage) resulted in spermatogenesis in the ovary of approximately 90% of females. Endocrine disruption may be caused in the giant abalone by organotin compounds from antifouling paints, which are possibly one of the causal factors for the decline of Japanese abalone stocks.
The authors developed a system to use skeletal muscle as an artificial heart actuator. This system consists of a flexible rod, sheath, crank, and cam to transmit the muscle power to a pusher plate pump and actuate it. The latissimus dorsi muscle was dissected at the lower ribs, and its end was connected with the flexible rod. The contraction of skeletal muscle was linearly transmitted, with the rod introduced inside the sheath, to the pump. The whole system was implanted in dogs (14-18 kg) and pump performance was evaluated with a mock circulatory system (preload = 10 mmHg, afterload = 75 mmHg). In these experiments, the pump output was maintained at 0.8 to 2.0 L/min (60 bpm) for 200 min, with a non-preconditioned muscle that was stimulated continuously. The output obtained was 2.5 mW/gram. Efficiency of this system was about 50% of the muscle power available. When the muscle was stimulated intermittently every 30 min, pump flow was maintained at > 0.8 L/min for 20 hr. Advantages of this system are: 1) the muscle power was linearly transmitted effectively, 2) this system could be installed with minimal surgery and without interruption in blood flow to the muscle, 3) the muscle is free from high intraventricular pressure that caused ischemia and, 4) the muscle can be set to the proper length in diastole to potentiate strong contractions.
Electrical properties of tissues sensitively reflect structural and physiologic changes. The authors examined the use of a dielectric spectrogram for instantaneous evaluation of ischemic injury of the liver. Wistar rats, which had enough collateral circulation for portal bypass with subcutaneous transposition of the spleen, were used. Four ischemic periods (15, 30, 60, and 120 min) were examined and followed by reflow. Permittivity and conductivity were measured at 39 frequency points in the 20 Hz-1 MHz range using an LCR meter system. They were then expressed in a loss tangent (LT) plot to clear their behavior. The maximum LT value (max-LT) and the minimum LT value (min-LT) of the normal liver were 3.98 +/- 0.28 and 2.98 +/- 0.22, and appeared in 15-20 kHz and 150-300 kHz, respectively. During the first 30 min after ischemia, max-LT decreased to 3.25 +/- 0.14 (p < 0.005) and its range shifted to 0.3-0.6 kHz, and min-LT decreased to 1.35 +/- 0.06 (p < 0.001) without shifting of range. Max-LT then decreased gradually and min-LT began to increase. After reflow, max-LT increased and higher max-LT was observed in the longer ischemic cases. Max-LT at 1 hr after reflow correlated negatively with recovery rate of bile flow at that time (y = -0.238x + 1.84, r2 = 0.82). Additionally, the difference between max-LT and min-LT at just before reflow (dif-LT) showed a significant correlation coefficient with recovery rate of bile flow at 1 hr after reflow (y = 2.22x -3.32, r2 = 0.92).
Establishment of safer cerebral protection remains an important issue in reducing cerebral complications during aortic arch repair. Various cerebral perfusion techniques have been used. Recently, the usefulness of retrograde cerebral perfusion (RCP) combined with hypothermia was reported. The authors evaluated the cerebral microcirculation during RCP by direct observation with a charge-coupled device (CCD) microscope. In six craniotomied, anesthetized swine, cardiopulmonary bypass was established by arterial perfusion through the femoral artery and venous drainage from the right atrium. The authors observed cerebral arteriolae and venulae on the brain surface. Each swine was cooled to a brain temperature of 20 degrees C. Perfusion was stopped, RCP was initiated with oxygenated blood through the superior vena cava, and cerebral perfusion pressure (CPP) was gradually increased. During antegrade cerebral perfusion (ACP), homogeneous vascular flow was observed in all models. During RCP, retrograde vascular flow was generated in four of the six models, but homogeneous retrograde vascular flow was achieved in arteriolae and venulae in only two models at a CPP of greater than 20 mmHg. It is suggested that homogeneous and effective retrograde perfusion may not be achieved at a CPP of less than 20 mmHg, and that RCP causes uneven microcirculation of the brain with a disadvantageous effect on cerebral protection when compared with ACP.
Blue-on-yellow (B/Y) perimetry was performed on 31 patients with non-insulin-dependent diabetes mellitus to study the loss of sensitivity to short wavelengths. Of these patients, 21 were without retinopathy (NDR) and 10 had early background retinopathy (SDR). Eleven normal subjects served as controls. The results were compared to white-on-white (W/W) perimetry. Foveal sensitivity determined by B/Y and W/W perimetry showed no significant difference between NDR, SDR and normals. However, the mean sensitivity in the central 30-degree area and that in the upper half of the central 20- to 30-degree concentric circular field were significantly decreased in B/Y perimetry in SDR patients (p < 0.05, p < 0.01, respectively). No significant sensitivity loss was detected in the W/W test. We conclude that there is a blue cone system sensitivity loss in the central 30-degree area, particularly in the upper half of the visual field and the paracentral area in diabetic patients with early background retinopathy.
Nine eyes suffering from retinal detachment with giant tear were treated successfully by pneumatic retinopexy, followed by conventional buckling procedures and cryopexy. The retina in six of the nine eyes reattached after initial operation, whereas two required additional injection of SF6 gas. The remaining eye, having developed low-grade proliferative vitreoretinopathy (PVR C1), was treated successfully with vitrectomy. Visual outcome was rather poor immediately after the procedures due to vitreous opacity caused by gas injection. However, all cases showed excellent visual acuity five months after surgery. Visual field examined in six cases after surgery showed no significant constriction. If the retinal flap is mobile, pneumatic retinopexy may be effective in treating retinal detachment with giant tear.
A 67-year-old woman was admitted for nephrotic syndrome. In spite of the lack of lymphadenopathy, hepatosplenomegaly and serum hyperviscosity, remarkable monoclonal IgM-proteinemia was demonstrated. Amyloid kidney was shown by renal biopsy. However, in the bone marrow and other organs, neither proliferation nor invasion of monoclonal immunoglobulin-producing cells was revealed by immunohistological investigations of the specimens biopsied or examined at autopsy, excluding Waldenström's macroglobulinemia. Immunosuppressive chemotherapy with cyclophosphamide, vincristine and prednisolone was effective in reducing serum IgM, but could not slow the progression of renal failure. This case suggested the association of generalized amyloidosis with excessive IgM-proteinemia caused by a non-malignant mechanism.
To investigate excitability of spinal neural function during stretching excises in patients with cerebrovascular disease (CVD), H-reflex was analyzed before, during and after 1 min. continued stretching of the affected arm. 10 hemiparesis patients with hypertonus and hyperreflex, mean age of 53.2 years were tested. H-reflex was recorded from the abductor pollicis brevis on the affected side after stimulation of median nerve in supine position. The persistence, amplitude and amplitude ratio of H/M during stretching were lower than those before and after in the patients with moderately increased muscle tonus. In patients with slightly and markedly increased, H-reflex was same before, during and after continued stretching. It is suggested that excitability of spinal neural function during 1 min. continued stretching was inhibited in the patients with moderately increased muscle tonus caused by CVD.
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