Long-term repopulation of hematolymphoid cells with only a few hemopoietic stem cells in mice.
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Animals↗
Biomedical subjects
H Ogata
Publications and source records attributed to H Ogata.
Assessment of autonomic function in traumatic quadriplegic and paraplegic patients by spectral analysis of heart rate variability.
We analyzed by means of autoregressive spectral analysis the spontaneous beat-to-beat heart rate variability (HRV) of quadriplegic and paraplegic male subjects at rest in the supine position. In agreement with our previous study, in nine of 15 quadriplegic patients only the high-frequency (HF: center frequency = respiratory frequency) component (a marker of vagal modulation of heart rate) was observed. In contrast, in six of the quadriplegic patients both the HF component and the low-frequency (LF: center frequency at approx. 0.1 Hz, 0.03-0.15 Hz in this study) component (a marker of sympathetic and vagal modulation of heart rate) were observed. However, in six quadriplegic patients who presented the LF component, (i) the center frequency of the LF component was lower than that in 10 healthy, sedentary, age-matched males (control I) (P < 0.01), (ii) the power of the HF component was smaller than that in the control-I group (P < 0.01) and (iii) the LF/HF power ratio (an index of sympathovagal balance) was larger than that in the control-I group (P < 0.05). On the other hand, in nine paraplegic patients with an intact 1st-4th thoracic spinal cord, from which the cardiac sympathetic nerves originate, the total power, the power of the LF component and that of the HF component were smaller than those in nine healthy, sedentary, age-matched males (control II) (P < 0.05, P < 0.01 and P < 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Long-term repopulation of hematolymphoid cells with only a few hemopoietic stem cells in mice.
A PCR-based assay has been devised for the detection and semiquantitation of cells originating from a few donor hematopoietic stem cells (HSCs) in a background of recipient cells. Upon sequencing a segment of murine Y chromosome contained in the plasmid pY2, oligonucleotide primers were designed for specific amplification of the Y chromosome-restricted segment. The HSCs were isolated from the bone marrow of mice on day 4 following a single i.v. injection of 5-fluorouracil and were readily distinguished from other bone marrow elements by the characteristics of low density, absence of lineage-specific surface markers, lack of expression of transferrin receptor, and a high expression of major histocompatibility complex class I antigen. Injection of as few as four such HSCs was shown to produce donor-derived cells (including lymphoid cells) for at least 8 months after transplantation into syngeneic female recipients. Retransplantation, employing 10(6) bone marrow cells from the initial recipients, also yielded clear evidence of repopulation with detectable levels of male donor cells. On statistical grounds, it is clear that long-term repopulation in vivo may result from even a single HSC having the characteristics defined herein.
Animals↗
Molecular cloning of the rat intestinal trefoil factor gene. Characterization of an intestinal goblet cell-associated promoter.
Intestinal trefoil factor (ITF) is a small peptide bearing the unique motif of intrachain disulfide bonds characteristic of the trefoil family. Previous work had localized expression of ITF primarily within goblet cells in the small and large bowel, making it a candidate gene for the study of the molecular basis of intestinal and goblet cell-specific gene expression. In order to study the regulation of ITF expression, we have cloned the rat ITF gene and sequenced 1.7 kilobases of the 5'-flanking region. RNase protection analysis demonstrated a single transcriptional start site. Various lengths of the 5'-flanking region were linked to the reporter gene luciferase and transfected into the colon cancer cell lines LS174T and Caco-2, representing, respectively, cells with and without goblet cell-like phenotype. Expression in the goblet cell-like LS174T colon cancer cell line was nearly 10-fold greater than expression in Caco-2 cells which exhibit columnar enterocyte-like phenotype. The pattern of goblet cell-associated selective transcription required only 153 base pairs of the rat ITF 5'-flanking sequence. Transfection of a construct of human growth hormone under the control of the rat ITF promoter in the N2 subclone of HT-29 cells demonstrated expression of the reporter gene only in those cells exhibiting a goblet cell phenotype as assessed by expression of immunoreactive mucin. These initial studies of the 5'-flanking region of the ITF gene demonstrate the presence of cis-regulatory elements capable of directing goblet cell specific expression.
Amino Acid Sequence↗
[Brain blood volume measured with near infrared spectroscopy increased after stellate ganglion block].
There are many controversies whether the brain blood flow increases or not after stellate ganglion block (SGB). We found in 10 outpatients that the brain blood volume increased after SGB using near infrared spectroscopy (NIRO500, Hamamatsu Photonics, Inc.). HbO2 showed peak level of 3.6 mumol.l-1 at 30 min and 2.2 mumol.l-1 at 40 min. Peak level of Hb was 5.6 mumol.l-1 at 40 min. These values indicated increased brain blood flow after SGB.
Adult↗
A genetic algorithm based molecular modeling technique for RNA stem-loop structures.
A new modeling technique for arriving at the three dimensional (3-D) structure of an RNA stem-loop has been developed based on a conformational search by a genetic algorithm and the following refinement by energy minimization. The genetic algorithm simultaneously optimizes a population of conformations in the predefined conformational space and generates 3-D models of RNA. The fitness function to be optimized by the algorithm has been defined to reflect the satisfaction of known conformational constraints. In addition to a term for distance constraints, the fitness function contains a term to constrain each local conformation near to a prepared template conformation. The technique has been applied to the two loops of tRNA, the anticodon loop and the T-loop, and has found good models with small root mean square deviations from the crystal structure. Slightly different models have also been found for the anticodon loop. The analysis of a collection of alternative models obtained has revealed statistical features of local variations at each base position.
Algorithms↗
Quantitative determination of unchanged cisplatin in rat kidney and liver by high-performance liquid chromatography.
A quantitative analytical method for measuring unchanged cisplatin (CDDP) and high- and low-molecular-mass metabolites (fixed and mobile metabolites) in rat kidney and liver was developed. Unchanged CDDP, separated from fixed and mobile metabolites in tissue homogenates by consecutive procedures of fractionation and ultrafiltration, was determined by high-performance liquid chromatography (HPLC) with post-column derivatization. Although unchanged CDDP was found to be partly metabolized to fixed metabolites during the preparation of cytosolic ultrafiltrates, the recovery of unchanged CDDP gave a constant value (about 70%), which was independent of tissue type and CDDP concentration (from 1 to 10 micrograms/ml). The detection limit for unchanged CDDP in the cytosolic ultrafiltrate was 20 ng/ml, corresponding to a concentration detection limit of 65 ng Pt per g of tissue in the kidney and liver. The concentrations of fixed and mobile metabolites were determined as platinum concentrations in the tissue homogenate and in the cytosolic ultrafiltrate using atomic absorption spectrometry after correcting for transformation of unchanged CDDP to fixed metabolites. The distribution of unchanged CDDP, mobile metabolites and fixed metabolites in rat kidney and liver, after bolus injection of CDDP (5 mg/kg), was determined using this method.
Animals↗
Effects of sodium thiosulfate on the pharmacokinetics of unchanged cisplatin and on the distribution of platinum species in rat kidney: protective mechanism against cisplatin nephrotoxicity.
To investigate the mechanism underlying the protective effect against cisplatin (CDDP) nephrotoxicity of its antidote, sodium thiosulfate (STS), the effects of STS on the pharmacokinetics of unchanged CDDP and on the distribution of unchanged CDDP and high and low molecular mass metabolites (fixed and mobile metabolites) in the kidney 1 min after a bolus injection of CDDP (5 mg/kg) to rats were studied. A decrease in the plasma concentration of unchanged CDDP and an increase in the plasma concentration of mobile metabolites were observed in the rats after the bolus injection of CDDP in combination with STS infusion for 30 min (1200 mg/kg). Although STS accelerated platinum excretion during the first 10 min after CDDP injection, unchanged CDDP was not excreted in the urine in the STS-treated rats. Total kidney platinum 1 min after the bolus injection of CDDP was detected mainly as unchanged CDDP (86% of the total platinum) in the rats given CDDP alone. However, in the STS-treated rats, the total kidney platinum was decreased to 62% of the level in the rats given CDDP alone, and the platinum species detected in the kidney were mainly mobile metabolites. Only 24% of the total kidney platinum was detected as unchanged CDDP in the STS-treated rats. The loss of body weight and increases in BUN and serum creatinine levels usually observed after a bolus injection of CDDP were completely prevented by STS coadministration. The present study provides information about unchanged CDDP pharmacokinetics and the distribution of unchanged CDDP and some of its generic metabolites in the kidney when STS is coadministered as an antidote. These results show that the protective effect of STS against CDDP nephrotoxicity can be attributed to the formation of inactive mobile metabolites by a direct reaction between unchanged CDDP and STS in the systemic circulation, resulting in a reduction in the amount of unchanged CDDP in the kidney.
Analysis of Variance↗
Peripheral neuropathies in the upper extremities of paraplegic wheelchair marathon racers.
In order to know if peripheral neoropathies in the upper extremities of paraplegic individuals are induced by participating in wheelchair marathon races, we performed nerve conduction studies bilaterally on the median, ulnar, and radial nerves of 10 male wheelchair marathon racers, and on 10 male sedentary paraplegic individuals. In five of 10 paraplegic racers, and in nine of 10 sedentary paraplegics there was a decrease of motor nerve conduction velocities and/or prolongation of motor or sensory nerve distal latencies. Abnormal results in all of the nerve conduction studies were 3.2% and 13.6% in paraplegic racers and sedentary paraplegics, respectively. Although paraplegic racers had fewer peripheral neuropathies in the upper extremities than did sedentary paraplegics, ulnar lesions due to involvement of the deep motor branch and at the elbow were a characteristic feature of nerve injuries, presumably caused by wheelchair marathon racing. It is suggested that although a wheelchair marathon is generally a safe sport, wearing gloves and handling a wheelchair in the correct way during the race are necessary to prevent nerve injuries.
Adult↗
Sexual activities and concerns in persons with spinal cord injuries.
A survey of sexual activity and concerns of people with spinal cord injury living in the community was undertaken. A questionnaire was sent to 144 people, and 102 replies were collected. Of the sample, 59.8% reported having engaged in some aspect of sexual life. Sexual life ranked the lowest in terms of importance with respect to other aspects of life. However, 47.1% answered that they were not satisfied with their sexual life. It was indicated that the provision of information regarding sexuality should remain a high priority for health care providers.
Adult↗
Does hypertonic saline have preventive effects against delayed neuronal death in gerbil hippocampus?
This experiment was conducted to ascertain whether or not hypertonic saline solution (HSS) has preventive effects on delayed neuronal death in the hippocampal CA1 subfield of the gerbil. Twenty-eight gerbils were anesthetized with 1% halothane and 50% nitrous oxide during the experimental period. Their common carotid arteries were occluded bilaterally for 2.5 min, immediately after which 2 mL/kg of 10% NaCl was infused via the tail vein. Two mL/kg of physiological saline solution (PSS) was used for the control group in the same manner. 5 days later, after the cerebrum was removed, the hippocampus was stained with hematoxylin-eosin, and histopathological changes in the CA1 subfield were observed under the light microscope. Degenerative or necrotic pyramidal cells were compared among groups. The degeneration rates of the pyramidal cells were as follows; after sham operation with PSS, 4.2 +/- 1.8%; after sham operation with HSS, 6.5 +/- 3.3%; on ischemia-reperfusion with PSS, 95.6 +/- 1.6%; on ischemia-reperfusion with HSS, 7.1 +/- 3.0%. This study suggested that hypertonic saline might prevent delayed neuronal death in the hippocampal CA1 subfield of gerbils subjected to cerebral ischemia-reperfusion.
Animals↗
Differential effects of vecuronium on the thumb and great toe as measured by accelography and electromyography.
We evaluated possible differential effects of vecuronium on the thumb and great toe using two types of neuromuscular transmission monitor. Train-of-four stimuli were simultaneously applied to the ulnar nerve and tibial nerves using cutaneous electrodes. The responses were quantified with accelographs (thumb and left great toe) and an electromyograph (right great toe). Twenty ASA 1 or 2 patients received, by random allocation, one of two types of anaesthesia: neuroleptanaesthesia or sevoflurane-based anaesthesia. With both techniques, the shortest time to maximum block after vecuronium 0.1 mg.kg-1 occurred in the thumb as measured by accelography. The average (SD) values with neuroleptanaesthesia were: 173(23) s for thumb using accelography; 220(16) s for great toe using accelography; 205(44) s for great toe using electromyography. The average (SD) value(s) with sevoflurane-based anaesthesia were: 137(15) for thumb using accelography; 179(21) for great toe using accelography; 153(23) for great toe using electromyography. The differences between the thumb and great toe were statistically significant during both types of anaesthesia when measured with the accelograph (p < 0.01). The time from completion of maximal block to 25% recovery of twitch height in the thumb was significantly longer than that of the great toe as measured by accelography during both types of anaesthesia (p < 0.05). In contrast, there were no statistically significant differences between time to maximum block and 25% recovery of twitch height of the thumb as measured by accelography compared to the values measured for the great toe using electromyography during either anaesthetic technique.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Edrophonium as an antagonist of vecuronium-induced neuromuscular block in the elderly.
Train-of-four stimuli were applied to the ulnar nerve using an accelograph in 10 elderly patients (aged 70-82 years) and 10 younger patients (aged 27-54 years). Anaesthesia was induced with thiopentone 5 mg.kg-1 and was maintained with nitrous oxide (66%) oxygen and sevoflurane (1 MAC). Vecuronium 0.1 mg.kg-1 was used for paralysis, and reversed with intravenous edrophonium 0.75 mg.kg-1 and atropine 0.015 mg.kg-1 when the train-of-four ratio returned to 25%. The times from initial administration of vecuronium to completion of maximal block were 211.5 (SD 66.9) s and 154.0 (SD 39.7) s in the elderly and younger patients, respectively (p < 0.05). The times from maximal block to 25% recovery of train-of-four ratio were 64.8 (SD 36.3) min and 61.8 (SD 36.3) min in the elderly and younger patients, respectively. There was no statistically significant difference between them. The reversal times from 25% to 75% of the train-of-four ratio after the administration of edrophonium were 210.0 (SD 136.7) s and 177.0 (SD 100.4) s in the elderly and younger patients, respectively. There was no statistically significant difference between them. The authors were unable to show that healthy elderly patients differ significantly from younger patients in the neuromuscular blocking effect of vecuronium and the reversal effect of edrophonium.
Adult↗
[Influence of stellate ganglion block on respiratory system].
The purpose of this study was to investigate the influence of a stellate ganglion block (SGB) or stellate ganglion electrical stimulation (SGES) on pulmonary resistance, on blood flows of the bronchial, pulmonary and common carotid arteries, and on arterial blood gases. Thirteen mongrel dogs were divided into two groups; a SGB group (n = 8) and a SGES group (n = 5). Anesthesia was induced with pentobarbital 25 mg.kg-1 and the animals were mechanically ventilated to maintain constant PaO2 (90-100 mmHg) and PaCO2 (35-40 mmHg). After a thoracotomy, the SGB with 0.5% mepivacaine 1.5 ml was performed, or the SGES was performed at a strength of 12 volts, and at a frequency of 50 Hz, applied for 30 min. In the SGB group, pulmonary resistance after the block did not significantly differ from the control. No significant change occurred in blood flows of the bronchial and pulmonary arteries, but the common carotid artery flow increased significantly after the SGB. Arterial blood gases did not change significantly after the SGB. In the SGES group, pulmonary resistance after the stimulation did not significantly differ from the pre-value. However, blood flows of the bronchial, pulmonary and common carotid arteries decreased significantly after the SGES. Arterial blood gases did not change significantly after the SGES. These results suggest that the SGB may not influence the respiratory system under normal conditions.
Animals↗
[Improvement of cerebral oxidative metabolism and cytochrome aa3 redox state by 7.5% hypertonic saline during hemorrhagic hypotension in dogs].
Our previous study reported that 20% (1.5 ml.kg-1 hypertonic saline could significantly improve the disturbances of cerebral oxidative metabolism induced by hemorrhagic hypotension in dogs. The aim of the present study is to evaluate if 7.5% hypertonic saline induces circulatory improvement. Ten dogs were randomly divided into two groups of 5 each resuscitated with either physiological saline as control or 7.5% hypertonic saline (4 ml.kg-1) after their mean arterial blood pressure decreased to 35 mmHg for 45 minutes by hemorrhage. The changes of cerebral tissue oxy- and deoxyhemoglobin, cerebral blood volume (total hemoglobin), and oxy-cytochrome aa3 were continuously monitored by near infrared spectroscopy throughout the experiment. The experimental result showed that oxy-hemoglobin, oxy-cytochrome aa3, and cerebral blood volume decreased but deoxyhemoglobin increased significantly 45 minutes after hemorrhage. Treatment with 7.5% hypertonic saline significantly restored these variables except for cerebral blood volume and all the animals survived to the end of experiment. But in the control group treated with the same dose of physiological saline, the above variables improved little compared with the baseline; and all the animals died before the end of 60 min experimental observation. Therefore we conclude that 7.5% hypertonic saline (4 ml.kg-1) can also effectively improve the disturbance of cerebral oxidative metabolism induced by hemorrhagic hypotension.
Animals↗
[Evaluation of malignancy and viability of brain tumors by 201Tl SPECT: the correlation between 201Tl SPECT and pathology, clinical progress and the intensity of enhancement on CT images].
Thallium-201 (201Tl) SPECT was performed 48 times in 26 patients to clarify its usefulness in the evaluation of malignancy and viability of brain tumors. The early counts ratio (ER) and delayed counts ratio (DR) of a lesion compared with normal brain were obtained 10-15 minutes and 3 hours, respectively, after intravenous administration of 185 MBq of 201Tl chloride. Untreated high grade malignant tumors and recurrent tumors did not always show high ER and DR, and they were widely distributed. High grade malignant tumors that showed low ER and DR were not well enhanced on CT or MRI. In low grade malignant tumors, such as pituitary adenoma which was well enhanced on CT, ER and DR were as high as in high grade malignant tumor. Whether a tumor recurred within three months after radiotherapy or not was retrospectively predicted at accuracy rates of 93.8% and 87.5% with cut-off points of 4.0 for ER and 3.5 for DR. Cerebral radiation necrosis showed ring-like increased uptake of 201Tl in proportion to the progress of necrosis and intensity of enhancement on MRI. In conclusion 201Tl SPECT is considered to be less useful for lesions that are well enhanced on CT, because they show high uptake of 201Tl regardless of their malignancy and viability. On the other hand, in tumors that are not well enhanced on CT. 201Tl shows good accumulation in viable and high grade malignant lesions. 201Tl SPECT should be performed in such cases.
Adult↗
Epitope analysis of SPan-1 and DUPAN-2 using synthesized glycoconjugates sialyllact-N-fucopentaose II and sialyllact-N-tetraose.
Epitope analysis of SPan-1 and DUPAN-2 was compared with that of CA19-9 using the synthesized glycoconjugate sialyllacto-N-fucopentaose II (SLF II, sialyl-Lewis(a)) and its precursor, sialyllact-N-tetraose (LSTa, sialyl-Lewis(c)), conjugated to human serum albumin. The CA19-9 and DUPAN-2 assay systems specifically recognized SLF II and LSTa, respectively. The SPan-1 assay system recognized both SLF II and LSTa, although the reactivity with the former was far stronger than that with the latter. These results were, in general, compatible with those obtained from assaying these markers in the sera of two pancreatic cancer patients with definite Lewis-negative phenotype and in the sera of 39 CA19-9-negative pancreatic cancer patients. In conclusion, DUPAN-2 is the precursor of CA19-9 and is accumulated in the sera of pancreatic cancer patients with Lewis-negative phenotype and SPan-1 has an advantage over CA19-9 in the diagnosis of patients with Lewis-negative phenotype, although both markers have almost the same sensitivity for this malignancy.
Antibodies, Monoclonal↗
Hypertonic saline improves cerebral oxidative metabolism and cytochrome aa3 redox state during hemorrhagic hypotension in dogs.
Hypertonic saline used in the treatment of hemorrhagic shock dramatically improves cardiovascular performance. In the present study, our focus was on whether it would improve disturbances of cerebral oxidative metabolism induced by hemorrhagic hypotension. Fourteen dogs were bled over a period of 15 min so that the mean arterial blood pressure of seven dogs (group H) fell to 65 mmHg and that of the other seven (group L), to 45 mmHg. These pressures were maintained for 30 min, and then 20% hypertonic saline (1.5 ml/kg body weight) was injected intravenously. Cerebral oxyhemoglobin, deoxyhemoglobin, cerebral blood volume, and oxidized cytochrome aa3 were continuously monitored by near-infrared spectroscopy throughout the experiment. The experimental results showed that 45 min of hemorrhagic hypotension led to decreases in cerebral oxyhemoglobin (from control level 0 to -25.5 +/- 7.5 microM/liter brain tissue in group H and to -32.3 +/- 7.5 microM/liter brain tissue in group L), in total hemoglobin (from control level 0 to -7.2 +/- 1.8 microM/liter brain tissue in group H and to -6.5 +/- 1.7 microM/liter brain tissue in group L), and in oxidized cytochrome aa3 in group L (from control level 0 to -0.8 +/- 0.4 microM/liter brain tissue), but to increases in deoxyhemoglobin (from control level 0 to 15.5 +/- 5.0 microM/liter brain tissue in group H and to 25.8 +/- 3.4 microM/liter brain tissue in group L) and in oxidized cytochrome aa3 in group H (from control level 0 to 0.6 +/- 0.3 microM/liter brain tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗