Biomedical subjects

S Minami

Publications and source records attributed to S Minami.

At least 235 records · Page 13Linked to original sources

PubMed1992

[A case report of multiple-transfused aplastic anemia complicated by hemolysis and delayed neutrophil recovery after bone marrow transplantation].

The authors report an 18-year-old female who developed severe hemolytic reaction and delayed neutrophil recovery after bone marrow transplantation (BMT) for aplastic anemia from her HLA-identical sibling. She had received much transfusion (61 units of red blood cells including 4 units of fresh whole blood from her parents and 350 units of platelets) for 12 years before BMT. To prevent graft rejection, she received an intensified preparative regimen consisted of cyclophosphamide 200 mg/kg followed by 5 Gy total body irradiation and 5 Gy total lymphoid irradiation. Prophylaxis for GVHD was short term methotrexate and cyclosporin-A. Despite of the removal of the red cells from the marrow, marked hemolytic reaction caused by antibodies directed to rh" (E) and hr' (c) red cell antigens was observed when rh" (E) and hr' (c) positive donor erythroid began to recover. The recovery of neutrophils, especially the fraction of segmented cells was also delayed. Flow cytometry showed that the serially collected patient's sera reacted to neutrophils derived from both patient's blood on the 64th post-transplant day and the donor's blood. The reactivity was strongest in pre-BMT sera. We conclude that residual antibodies sensitized before BMT are a major cause of these hematological problems.

Adolescent↗

PubMed1991

The time-space correlation method for measurement of erythrocyte velocity in microvessels using a CCD linear image sensor.

A new method for measuring erythrocyte velocity in the microvascular system was developed. A correlation function varying both time and distance, "time-space correlation method," was used in order to improve the time correlation and the space correlation methods. A CCD linear image sensor installed at the center of the focal plane of a camera was used to convert the passage of erythrocytes through the microvascular system to electrical signals via intravital microscopy. The method was applied to small vessels in the mesentery of rats. Using the present method, the time required for the measurement and the length of the vessel necessary for the measurement have been reduced, as compared with other methods.

Algorithms↗

PubMed1991

Alternating current induced otoacoustic emissions in the guinea pig.

Injection of alternating current (AC) into the scala media of the guinea pig cochlea induced otoacoustic emissions (OAEs) at the frequency of the AC fundamental, together with harmonic and intermodulation distortion products. Although the waveform of the injected ACs was distorted, probably due to nonlinear polarization of the metal electrodes, and was composed of the fundamental plus distortion products of every order, only a few of the lowest order distortion products were selectively emitted with the fundamental. AC injection at a basal site extended the high frequency limit of OAEs. Electrical stimulation of the crossed olivocochlear bundle inhibited the sideband emissions with little change in the fundamental. OAE was reduced reversibly by temporary impairment of the cochlea due to exposure to fatiguing sound, by intravenous application of furosemide and by temporary anoxia. Irreversible reduction resulted from intracochlear perfusion with excess K+ solution, acoustic trauma and cardiac arrest. These facts imply that AC-induced OAE is not an artifact generated electrically; rather, such emissions originate in the cochlea and normal metabolic activity in the cochlea is essential. A proposed mechanism of generation includes two components: 1) electromechanical transduction from AC to mechanical vibration in the cochlea and 2) a distortion-producing process; the contribution of each component to the receptor mechanism is discussed.

Acoustics↗

PubMed1991

Significance of inducible cephalosporinase remaining in the experimentally infected rat granuloma pouch after beta-lactam therapy.

We studied the influence of inducible cephalosporinase on levels of secondarily administered beta-lactam antibiotics in exudates using experimentally infected rat granuloma pouches. Cefoperazone or cefmetazole was administered intramuscularly at a dose of 100 mg/kg of body weight to rats at 2 and 8 h after infection of rat pouches with Serratia marcescens W-24, which possesses an inducible type I beta-lactamase (cephalosporinase). Subsequently, cefotaxime or cefbuperazone was administered at an intravenous dose of 100 mg/kg to rats at 24 h postinfection. Levels of cefotaxime in the pouch exudates of the cefmetazole-pretreated group were lower than those in the control group, which was infected but not pretreated with antibiotics. This was due to the inactivation of cefotaxime by extracellular cephalosporinase which was induced by cefmetazole and which remained in the rat pouches. However, cefotaxime concentrations were not reduced in the cefoperazone-pretreated group because of the low inducibility of cefoperazone against cephalosporinase production. On the other hand, cefbuperazone concentrations were similar in all groups (control, cefoperazone pretreated, and cefmetazole pretreated), because cefbuperazone is more stable against this enzyme than cefotaxime is. In conclusion, concentrations of secondarily administered beta-lactam antibiotics are affected by inducibly produced cephalosporinase at the infection site when a good inducer like cefmetazole is administered beforehand.

Animals↗

PubMed1991

Electrical stimulation of hypothalamic periventricular nucleus is followed by a large rebound secretion of growth hormone in unanesthetized rats.

The effect of electrical stimulation of the hypothalamic periventricular nucleus (PVN) on plasma GH profile was studied in unanesthetized female Wistar rats. A bipolar concentric electrode was implanted into the PVN, hypothalamic ventromedial nucleus (VMH), or intervening area between the PVN and VMH. Serial blood specimens were collected from an indwelling right atrial cannula. Plasma GH levels were reduced significantly during electrical stimulation of PVN, and a large rise of plasma GH levels followed after cessation of stimulation. An identical plasma GH profile was observed in response to the repeated stimulation. This rebound secretion of GH was completely inhibited by the administration of rat GRF antiserum. The effect of electrical stimulation of VMH on plasma GH levels was similar to that of PVN stimulation. However, the stimulation of hypothalamic area intervening between PVN and VMH was not followed by a surge of GH secretion. Since a continuous exposure of somatotrophs to GRF even in a concurrent presence of somatostatin (SS) is known to induce attenuation of the GH response to GRF through receptor effect, the results suggest that the release of endogenous GRF is augmented following the cessation of electrical stimulation of neurons providing hypophysiotropic SS.

Animals↗

PubMed1991

Immunohistochemical localization of inhibin subunits in human corpora lutea during menstrual cycle and pregnancy.

The cellular localization of the alpha-, beta A-, and beta B-subunits of inhibin was studied in human corpora lutea (CL) during the menstrual cycle and pregnancy. Immunohistochemical techniques using antisera selective for each subunit were used to localize the polypeptide chains. Immunoreactive staining with antisera against the alpha-, beta A-, and beta B-subunits was mainly observed in granulosa luteal cells (luteal cells), whereas thecal luteal cells were faintly stained with antibodies selective for each inhibin subunit. The intensity of immunostaining with alpha-subunit antiserum in luteal cells increased from the early luteal phase to the midluteal phase and subsequently decreased toward the late luteal phase. Inhibin alpha-subunit in the retrogressive CL was not detected. Not only was the immunolocalization of both beta A- and beta B-subunits detected in the luteal cells of the CL of the cycle, but the relative intensity of immunostaining with beta-subunit antiserum changed in a pattern similar to that shown by the alpha-subunit. The luteal cells and thecal luteal cells in the CL of pregnancy exhibited positive staining with antisera directed against each inhibin subunit. The present findings provide further evidence that 1) immunoreactive inhibin subunits are present in luteal cells in the CL of the menstrual cycle; 2) the detectable level of each subunit changes in parallel with the function of the CL over the course of the menstrual cycle; and 3) the CL of pregnancy might be involved in serum inhibin elevation early in gestation.

Adult↗

PubMed1991

Growth hormone secretion in stalk-sectioned rats.

Idiopathic pituitary GH deficiency appears to result from neonatal disruption of hypophyseal portal vessels in the majority of patients. To examine the mechanism of GH deficiency associated with the disease, the effect of pituitary stalk section on GH secretion was studied in rats. Adult male rats were subjected to stalk section without inserting an impermeable membrane between the cut ends. They were studied 3 to 4 weeks after surgery. In stalk-sectioned rats, pituitary weight, body weight and hypothalamic SRIH content were significantly reduced as compared with sham-operated rats. Hypothalamic GHRH content, plasma T3, T4, corticosterone and testosterone levels, and weights of testes remove and adrenal glands were comparable in the two groups. Plasma GH profiles of sham-operated rats showed characteristic periodic pulses occurring at 2.5-3 h intervals with intervening trough period. In stalk-sectioned rats, plasma GH levels were low small fluctuations, but GH levels were significantly higher than trough levels of sham-operated rats. The amount of GH secreted during a 6-h period as measured by planimetry was significantly reduced. To ascertain the regeneration of hypophyseal portal vessels, post SRIH rebound in GH secretion, which requires the presence of endogenous GHRH, was examined. Withdrawal of exogenous SRIH infusion triggered a large rebound GH secretion whose magnitude did not differ between groups. In stalk-sectioned rats, GH response to met-enkephalin analogue, FK 33-824, was not observed, whereas prolactin response to the secretagogue was observed in the majority of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

[Early experience with an ileocolic bladder substitution (Mainz pouch) in 11 cases].

In the last decade, many continent urinary diversions have been developed for the cystectomy patients. Mainz pouch, which seems to be a sophisticated one without using an alloplastic prosthesis, was adopted in our clinic. We preliminarily report our result in 11 patients who underwent a Mainz pouch procedure in the last 2 years: 1 for bladder augmentation, 5 for total bladder substitution after cystoprostatectomy and 5 (including 2 females) for continent urinary diversion. The mean age of them was 54 years old and the follow up periods ranged from 6 to 24 months. The antimesenteric longitudinal incision of the ileum and cecum and their sutures were performed similarly to the usual detubularized intestinal pouch. The ureteral reimplantation to the colonic segment was accomplished by the submucosal tunnel method. Although the ureteral hiatus was initially positioned at the anal edge of the colon, a new hiatal creation by stabbing the more oral portion of the colon according to the Goodwin's ureterocolic anastomosis was subsequently employed to avoid the trouble of closure of this portion. When the urethral anastomosis was achieved by 4-5 interrupted sutures between the most dependent portion of the cecum and the urethral stump after cystoprostatectomy, the mucosa was everted to the colonic serosa to prevent the stricture. The continent stoma was created by an intussusception of the proximal ileum, which was stabilized by the seromuscular stripping and 2-3 rows of external metal staples. Complication of the alimentary system occurred in 6 of 11 cases (55%), though they were successfully treated by an appropriate conservative management except one who suffered an ileostomy and nephrostomy because of severe panperitonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Two cases of nephrotic syndrome associated with hydronephrosis].

We reported two cases of nephrotic syndrome associated with hydronephrosis. A forty four year old male patient who suddenly complained of nephrotic syndrome, showed left hydronephrosis caused by lower ureteral stenosis. Renal biopsy specimen obtained from the right kidney revealed minor glomerular abnormalities. A sixteen year old female patient had a long history of proteinuria before the onset of nephrotic syndrome. She suffered from bilateral hydronephrosis of which the etiology was unclear. Renal biopsy specimen obtained from the left kidney revealed membranous nephropathy. Because in both cases urine samples collected from each ureter showed the presence of a massive protein, the other kidney was thought to be involved with the same disease. The association of nephrotic syndrome with hydronephrosis is extremely rare. The significance of this unusual combination was discussed with respect to the literature.

Adolescent↗

PubMed1991

[Three cases of minocycline-induced pneumonitis].

All three patients complained of cough, fever and dyspnea. Their chest X-ray films revealed interstitial changes such as Kerley B lines. The results of lymphocyte stimulation tests were all negative for Minocycline (MINO), whereas the provocation tests were all positive in three cases. The onsets of symptoms appeared 7, 12 and 9 hours after administration of MINO respectively, which suggested type III allergy in terms of the latency period. In cases No. 1 and No. 3, lung tissue specimens obtained by transbronchial biopsy showed findings of mild acute eosinophilic pneumonia. The bronchoalveolar lavage fluid of case No. 3 showed eosinophilia. On diagnosing MINO-induced pneumonitis, the lymphocyte stimulation test is not always beneficial, whereas the provocation test is supposed to be a safe and sure method.

Adult↗

PubMed1991

[Experimental study on local attachment of Beriplast P membrane including MMC].

We studied the effect of Beriplast P membrane including MMC (2 mg/ml) on human gastric carcinoma implanted in nude mouse (OSS) as a example of a shallow but broad lesion as with an early-stage local recurrence of rectal cancer and superficial gastric cancer. As a result, the resected tumor contact Beriplast P membrane including MMC after 3 days showed continuous necrotic lesions, from 1 to 2 mm in depth. No side effect was observed in nude mice. These results indicated that Beriplast P membrane including MMC is a useful chemotherapy against local cancerous lesion.

Animals↗

PubMed1991

[Delay in red blood cell recovery after major ABO incompatible bone marrow transplantation].

In 6 of 27 patients in whom major ABO incompatible marrow was transplanted, the recovery of red blood cells (reticulocyte count greater than or equal to 1%) required more than 50 days after the transplantation. In 3 of them, more than 100 days were required. High titers of pre-transplant anti-A or anti-B agglutinin correlated with the delay in red blood cell recovery (IgM: p less than 0.01, IgG: p less than 0.05). In all of the patients whose pre-transplant IgM titers were 4 or less, and whose IgG titers were 32 or less, the red blood cells recovered within 50 days. Administration of cyclosporine did not correlate with the delay in red blood cell recovery. All the patients finally developed red cell production within 8 months without any treatment.

ABO Blood-Group System↗

PubMed1990

Effect of intermittent infusions of somatostatin on growth hormone secretion in unrestrained male rats with hypothalamic deafferentation.

The effect of intermittent infusions of somatostatin (SS) on growth hormone (GH) secretion was studied in unrestrained adult male rats deprived largely of SS influence on the medial basal hypothalamus by anterolateral deafferentation (AL-cut). In addition, the influence of hypothalamic surgery on the plasma GH response to beta-endorphin (beta-END) was observed. In sham-operated rats, high-amplitude GH pulses separated by low baseline levels occurred at 185 min intervals. In rats with AL-cut, GH pulses were difficult to identify upon visual appraisal and baseline plasma GH levels became significantly higher than those of sham-operated rats. When AL-cut was performed unilaterally (half-AL-cut), low amplitude GH pulses separated by elevated baseline GH levels occurred at frequent intervals. The amount of GH secreted during 6 h was significantly reduced in rats with AL-cut or half-AL-cut as compared to that of sham-operated rats. The plasma GH response to intracerebroventricular injection of beta-END (4 micrograms) was abolished in AL-cut rats, and the response was significantly reduced in half-AL-cut rats as compared to that of sham-operated rats. When AL-cut rats were subjected to repeated infusions of SS (30 micrograms/kg b. wt./h, 150 min) separated by 30 min control periods, a large rebound of GH secretion was observed after removal and the amount of GH secreted during 6 h became comparable to that of sham-operated rats. The results suggest that SS plays important roles in the dynamic secretion of GH.

Animals↗

PubMed1990

Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures.

To characterize the effect of ethanol on the hypothalamic beta-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of beta-endorphin (beta-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of beta-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of beta-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on beta-EP secretion for a longer time. The magnitude of the beta-EP response to 50 mM ethanol is similar to that of the beta-EP response to 56 mM of potassium. Ethanol-stimulated beta-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.

Animals↗

PubMed1990

Dermal nerve sheath myxoma.

A case of dermal nerve sheath myxoma on the left palm of 26-year-old Japanese man is presented. We examined this tumor by light and electron microscopies. On light microscopic examination, this tumor was characterized by a multilobulated myxoid tumor composed of stellate cells in an abundant mucous matrix. This histological feature resembled previously reported cases of dermal nerve sheath myxoma. On electron microscopic examination, the findings of these tumor cells were similar to those of the perineurial cells. These microscopical examinations have provided evidence for an origin from perineurial cells rather than Schwann cells.

Adult↗

PubMed1990

Intracellular activity of tosufloxacin (T-3262) against Salmonella enteritidis and ability to penetrate into tissue culture cells of human origin.

The intracellular antimicrobial activity of tosulfoxacin was tested against Salmonella enteritidis C-32 by using human lung fibroid WI-38 cells and was compared with those of ofloxacin and norfloxacin. The intracellular antimicrobial activities of these drugs were evaluated by determining the numbers of viable organisms remaining within cells after treatment with various drug concentrations. At 0.2 and 0.78 microgram/ml, tosufloxacin suppressed intracellular multiplication of S. enteritidis C-32 more effectively than ofloxacin and norfloxacin did. The ability of tosufloxacin to penetrate into WI-38 cells was also determined by the velocity gradient method. The ratio of the intracellular concentration to the extracellular concentration of tosufloxacin was 1.7- and 2.6-fold higher than those of ofloxacin and norfloxacin, respectively. The results indicate that the potent intracellular bactericidal activity of tosufloxacin may be due not only to its high in vitro activity but also to its ability to penetrate into cells at a high level.

Anti-Infective Agents↗

PubMed1990

Gallbladder carcinoma: evaluation with MR imaging.

Magnetic resonance (MR) images of 19 patients with histologically proved gallbladder carcinoma were retrospectively reviewed to determine the appearance of the primary tumor, and to assess the ability of MR imaging to demonstrate the various modes of tumor spread beyond the gallbladder. The primary tumor, as well as tumor spread beyond the gallbladder, was hyperintense on T2-weighted images and hypointense on T1-weighted images when compared with the liver parenchyma. Liver invasion and metastasis could be depicted by MR imaging with both sequences, unless the tumors were small or the extent of invasion was minimal. Duodenal invasion was difficult to evaluate because of motion artifacts, paucity of fat, and partial volume effects. T1-weighted images readily demonstrated extension of the tumor to the hepatoduodenal ligament and para-aortic region with good contrast between tumor and surrounding tissue. The extent of tumor extension to the blood vessels was also easily evaluated because of flow void in the vasculature. MR imaging can help determine the extent of gallbladder carcinoma and can contribute to the staging of this disease.

Adenocarcinoma↗

PubMed1990

Facilitatory role of neuropeptide Y on the onset of puberty: effect of immunoneutralization of neuropeptide Y on the release of luteinizing hormone and luteinizing-hormone-releasing hormone.

To examine the role of neuropeptide Y (NPY) in the first luteinizing hormone (LH) surge of puberty, the effect of passive immunoneutralization of NPY with antiserum against NPY (anti-NPY) injected centrally (third ventricle) or peripherally (jugular vein) was studied in pubertal female rats on the day of first proestrus. Both peripheral and central anti-NPY administration reduced the magnitude of the LH surge during the afternoon of first proestrus; however, the central route of administration appeared to be most effective. Centrally administered anti-NPY also reduced the magnitude of proestrous LH-releasing hormone (LHRH) release into pituitary portal blood in these rats. These results suggest that endogenous NPY plays a facilitatory role in the generation of the LHRH surge necessary for preovulatory gonadotropin release and puberty.

Animals↗