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Biomedical subjects

K Saitoh

Publications and source records attributed to K Saitoh.

At least 37 records · Page 2Linked to original sources
PubMed2001

Morphological diagnoses of the Japan adult leukemia study group acute myeloid leukemia protocols: central review.

A morphological review system of the Japan Adult Leukemia Study Group has developed from the AML-87 through the AML-92 experience. We reviewed 1427 (90%) of 1592 cases enrolled in the AML-87, -89, or -92 protocols for morphology; 1408 (88%) were eligible. The rate of diagnostic concordance between each institute and the Committee on Morphological Diagnosis ranged from 76% to 80%. Acute myeloid leukemia (AML) subtypes were as follows: AML M0, 27 (2%); M1, 179 (13%); M2, 472 (34%); M3, 358 (25%); M4, 265 (19%); M5, 57 (4%); M6, 39 (3%); and M7, 11 (1%). The reason for the high number of patients with AML M3 is that many M3 patients were enrolled in the AML-92 protocol, which contained all-trans-retinoic acid. AML M0, M6 and M7 belonged to the poor prognostic groups. Auer bodies were found in 284 (53%) of 538 patients who survived significantly longer than those without Auer bodies in AML-87/-89. In AML-92 except for AML M3, 259 (43%) of 602 cases were Auer+ and also showed better survival rates. The survival of patients with >50% myeloperoxidase (MPO)-positive blast cells was better than those with < or =50% MPO+ blast cells in AML-87/-89. This trend was also seen in AML-92 excluding M3. AML with trilineage dysplasia (AML/TLD) is characterized as a subtype of de novo AML that shows morphological dysplasia of mature hematopoietic cells on a background of leukemic blast cells The number of patients with AML/TLD was 89 (16.5%) of 545 patients reviewed in AML-87/-89. AML-92, except for M3, showed a higher rate of patients with TLD (161 cases; 27.6%) because there were no patients with TLD in the AML M3 group. Survival rates for AML/TLD were worse than those for AML/non-TLD in both the AML-87/-89 and -92 protocols. Eighty percent of all cases (793/986) entered in AML-92 were analyzed cytogenetically. Fifty-one cases were not available for karyotyping because of a lack of mitoses or inappropriate preparations. The most frequent karyotype was normal, which accounted for 34.2%. The t(15;17), t(8;21), and inv(16) karyotypes, which are regarded as good risk factors, were 23.8%, 9.2%, and 1.6%, respectively. Abnormal chromosomes 5, 7, t(9;22), and t(6;9) were considered to be poor or intermediate risk factors As a new system of karyotyping begins in the ongoing AML protocol, useful chromosomal data will be obtained in the near future.

Acute Disease↗
PubMed2001

PCDD/DF formations by the heterogeneous thermal reactions of phenols and their TiO2 photocatalytic degradation by batch-recycle system.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) formation by the thermal reactions of phenols with CuCl2 under oxygen flux were carried out in relation to their formation mechanisms. To evaluate the effect of photocatalytic degradation of titanium dioxide (TiO2) thin film prepared by the sol-gel method, the photocatalysis of PCDD/DFs in acetonitrile/water solution by batch-recycle system was conducted. For the thermal reaction system of powder mixtures of 2,4,5-trichlorophenol (2,4,5-TCP) and CuCl2, the formation rates were 8.1 microg/g-2,4,5-TCP/min for total PCDD/DFs and 6.9 microg/g-2,4,5-TCP/min for PCDDs, and total PCDD/DF rate was higher by approximately 40 fold compared to phenol vapor/oxygen/CuCl2 powder system. For the system of 2,4,5-TCP, PCDDs were mainly formed via ortho-phenoxyphenols (POP) intermediate by the condensation of 2,4,5-trichlorophenate. For PCDD/DF photocatalytic degradations, most PCDD congeners photodecomposed rapidly and the rates presented more than 70% (as dechlorination rates of 76% for PCDDs) at 24 h after irradiation, using PCDD/DFs formed with 2,4,5-TCP. The rate constants were in the order of 4.8-6.1 x 10(-3) min(-1), assuming the pseudo-first-order reactions for their low levels.

Air Pollutants↗
PubMed2001

Comparative study of fibrous dysplasia and osteofibrous dysplasia: histopathological, immunohistochemical, argyrophilic nucleolar organizer region and DNA ploidy analysis.

Fibrous dysplasia and osteofibrous dysplasia are both benign fibro-osseous lesions of the bone. We retrospectively studied the clinicopathological findings in 90 cases of fibrous dysplasia and 17 cases of osteofibrous dysplasia. In these cases, the expression of proliferating cell nuclear antigen (PCNA) and the presence of argyrophilic nucleolar organizer regions (AgNOR), as well as DNA ploidy, were examined. The bones affected by fibrous dysplasia were the maxilla, femur and frontal bone. Osteofibrous dysplasia occurred exclusively in the tibia or fibula. The average age of patients with fibrous dysplasia (24.0 years) was higher than that of patients with osteofibrous dysplasia (12.9 years). Fibrous dysplasias were divided into four major histological subtypes: Pagetoid, Chinese alphabet, small bone and parallel bone. Bone lining cells, which are known as resting osteoblasts, were seen in some cases of fibrous dysplasia. Cartilage differentiation was not seen in osteofibrous dysplasia. PCNA expression was strongly positive in the nuclei of osteoblasts around the bone trabeculae in osteofibrous dysplasia, but negative in the nuclei of bone lining cells around the bone trabeculae in fibrous dysplasia. The number of AgNOR in osteofibrous dysplasia was slightly higher than that in fibrous dysplasia. Both fibrous dysplasia and osteofibrous dysplasia were diploid. These features suggest that fibrous dysplasia can be differentiated from osteofibrous dysplasia by anatomical site, patient age, histological appearance, cartilage differentiation and PCNA positivity. DNA content by image cytometry is not a useful tool for differentiating these two diseases.

Adolescent↗
PubMed2001

Structural study of an Al73Ni22Fe5 decagonal quasicrystal by high-angle annular dark-field scanning transmission electron microscopy.

A water-quenched Al73Ni22Fe5 decagonal quasicrystal was investigated by the selected-area electron diffraction, convergent-beam electron diffraction and high-angle annular dark-field scanning transmission electron microscope methods. The alloy shows very sharp spots and nearly no diffuse scattering in the diffraction patterns, belongs to centrosymmetric space group P10(5)/mmc and is constructed almost by one type of 2 nm diameter atom cluster having mirror symmetry with a highly quasicrystalline order arrangement. Although a small number of 2 nm atom clusters having five-fold symmetry exists, which are similar to those observed in melt-quenched Al70Ni15Fe15, the structure of Al73Ni22Fe5 is considered to basically be the same as that of water-quenched Al72Ni20Co8, which is constructed only by mirror symmetry clusters arranged with a very high quasiperiodicity. The number of valence electrons per atom (e/a) of the present alloy (1.92) is very close to that of Al72Ni20Co8 (1.90), but differs from those of phases constructed by only the five-fold symmetry clusters. This implies that these alloys are Hume-Rothery electron compounds, whose structures are determined primarily by e/a value.

Journal Article↗
PubMed2001

The structure of Si nanocrystals on SiC.

Si nanocrystals grown on cubic SiC have been characterized using high-resolution transmission electron microscopy. At lower temperatures nanocrystals grow in two different orientations, whereas at higher temperatures they grow in a single preferred orientation. The nanocrystals are shown to be unstrained; in some cases possibly due to the presence of a thin amorphous wetting layer.

Letter↗
PubMed2001

Effects of Ca(2+) and calmodulin on the motile activity of characean myosin in vitro.

It is well known that the cytoplasmic streaming of characean cells is readily inhibited by Ca(2+). However, neither the actin-activated MgATPase nor the in vitro motile activity of purified characean myosin were inhibited by Ca(2+). Recently, amino acid sequence of characean myosin was determined in our laboratory and the sequence revealed that characean myosin contains six calmodulin binding sites in the neck region. We also detected calmodulin in quickly prepared characean myosin fraction. It is, therefore, possible that the insensitivity of characean myosin to Ca(2+) is due to the dissociation of some calmodulin molecules from the neck region during the course of protein purification. To determine strictly the Ca(2+) sensitivity of characean myosin, we intentionally used crude preparation of characean myosin to reduce the possibility of calmodulin dissociation and examined the motile activity of characean myosin in vitro in the presence of excess characean calmodulin. We could not observe any drastic inhibition of characean myosin activity by Ca(2+). The results suggest that the brief cessation of cytoplasmic streaming is not caused by the direct inhibition of myosin activity by Ca(2+).

Actins↗
PubMed2001

Ionic mechanisms underlying burst firing of layer III sensorimotor cortical neurons of the cat: an in vitro slice study.

We examined the ionic mechanisms underlying burst firing in layer III neurons from cat sensorimotor cortex by intracellular recording in a brain slice. Regular spiking was observed in 77.4% of 137 neurons in response to constant intracellular current pulses of 0.5- to 1-s duration. The rest of the neurons showed burst firing. An initial burst followed by regular-spike firing was seen in 71.0% of 31 bursting neurons. The rest of the bursting neurons (n = 9) exhibited repetitive bursting. In the bursting neurons, spikes comprising the burst were triggered from the afterdepolarization (ADP) of the first spike of the burst. We examined the ionic mechanisms underlying the ADP by applying channel-blocking agents. The ADP was enhanced (rather than blocked) by Ca2+ channel blockade. This enhancement of the ADP by Ca2+ channel blockade was apparent even after blockade of the afterhyperpolarization by apamin or intracellular Ca2+ chelation by EGTA. The firing rate of the regular-spiking cells was increased by apamin, intracellular EGTA or Ca2+ channel blockers. In 17.9% of the neurons examined (n = 56), these agents switched the regular-spiking pattern into a bursting one. Burst firing could not be changed to regular spiking by these agents. Four neurons that responded with a single initial burst in control solution responded with repetitive bursting after application of these agents. We conclude that the main function of Ca2+ influx in layer III neurons is to activate Ca2+-dependent K+ conductance, which prevents or limits burst firing. At a time when spike amplitude was unchanged, the ADP was blocked and the burst firing changed to regular spiking by extracellularly applied tetrodotoxin (TTX) or intracellularly applied N-(2,6-dimethylphenylcarbamoylmethyl) triethyl ammonium bromide (QX314). We concluded that a TTX- and QX314-sensitive Na+ current underlies the ADP and therefore contributes to the burst firing of layer III neurons from the cat cortex.

Action Potentials↗
PubMed2001

Differences in respiratory parameters during continuous positive airway pressure and pressure support ventilation in infants and children.

The extubation criteria of pressure support ventilation (PSV) in infants and children were not yet established. We studied the differences in respiratory parameters during continuous positive airway pressure (CPAP) using a constant flow type ventilator and PSV using a demand valve type ventilator. Nineteen children (1.9+/-2.9 years old) who were ready to extubate were studied. All patients had recovered from their respiratory failure and had finished the weaning process of the ventilatory support. They were scheduled for extubation on the next day when their ventilatory mode had attained to a PSV of 3 cmH2O with a positive end-expiratory pressure (PEEP) of 3 cmH2O. On the extubation day, tidal volume (TV) and respiratory frequency (RR) were measured with a respiratory monitor at two modes (CPAP of 3 cmH2O and PSV), and the duty ratio (DR) and mean inspiratory flow (MF) were calculated. The sequence of the ventilatory mode was random. No case required reintubation. TV was 61.6+/-54.9 during CPAP and 67.7+/-61.4 ml during PSV, and RR was 38.5+/-10.6 and 37.1+/-8.8 beats/min., respectively. DR was 0.382+/-0.067 and 0.359+/-0.085, and MF was 96.6+/-78.3 and 101.0+/-69.0 ml/sec., respectively. The measured parameters and calculated values showed no significant difference between CPAP and PSV. It was found that the respiratory parameters were almost the same with CPAP and PSV immediately before the extubation, and the previous extubation criteria of CPAP can be used.

Blood Gas Analysis↗
PubMed2001

Evaluation of tube compensation in the Bennett 840 ventilator--a new ventilatory mode to support spontaneous breathing.

Respiratory care patients frequently require intubation with an endotracheal tube (ETT). Unfortunately, the ETT introduces a pressure drop (deltaPETT) that depends on the respiratory flow rate, thus increasing the work of breathing (WOB). Pressure support ventilation (PSV) cannot adequately compensate for this added WOB, because the degree of inspiratory assistance by PSV is fixed. Therefore, a technique called tube compensation (TC) has been developed to address deltaPETT. We examined the performance of TC and compared it with PSV of 5 cm H2O. The experimental system was constructed from a simulator, a test-lung, flow sensors, and a Bennett 840, and the respiratory parameters were studied. ETTs with IDs 6.5 and 8.0 mm were used. The quadratic approximation obtained for deltaPETT in the 6.5-mm ETT was 2.316 x flow + 7.910 x flow2, while that for the 8.0-mm ETT was 1.881 x flow + 3.353 x flow2. The maximum inspiratory flow (MIF) increased significantly with increasing TC, but tidal volume and inspiratory time did not show marked changes. The MIF for TC of 100% was larger than that for PSV of 5 cm H2O, when the 6.5-mm ID was used, but there was no significant difference between these modes when an ID of 8.0 mm was used. For both the 6.5 and 8.0-mm IDs, the PV loop corresponding to 100% TC was larger than that for PSV of 5 cm H2O. TC only compensated for the WOB caused by the ETT, whereas PSV compensated for the WOB caused by the ETT and the demand valve system. In clinical use, the differences between TC and PSV will demand attention.

Humans↗
PubMed2001

[Establishment of a reference interval for highly sensitive CRP by exclusion of individuals with abnormal values in related laboratory tests].

In November, 1999, U.S. Food and Drug Administration approved a highly sensitive CRP(hs-CRP) assay that could assist medical doctors to predict the risk of cardiovascular accidents. Many doctors are now interested in the assay and trying to elucidate the relationship between serum CRP levels and cardiovascular diseases. In the past, it was difficult to establish a valid reference interval of serum CRP because of the poor analytical sensitivity and difficulty in sampling reference individuals. We have established a reference interval of serum CRP for the hs-CRP assay(Dade Behring). The study population consisted of 7,224 individuals(21-81 years old) who received a regular medical check-up. Potentially abnormal samples were excluded, depending on the results of other laboratory tests related to serum CRP variation. The upper limit of the reference interval was 0.15 mg/dl. The serum CRP was higher in smokers than in non-smokers, especially in men.

Adult↗
PubMed2001

[Anesthetic management of a morbidly obese patient undergoing laparoscopic gastric bypass surgery].

We describe a successful anesthetic management of a morbidly obese patient, weighing 170 kg, height of 170 cm and body mass index of 58.8 kg.m-2, who received gastric bypass surgery performed using laparoscopic assist. After arriving in the operating room, an epidural catheter was inserted into the epidural space at the T 7-8 intervertebral space. The trachea was intubated nasally under bronchofiberscopic assist, after which anesthesia was induced with propofol and maintained with nitrous oxide and oxygen (FIO2 = 0.5), i.v. propofol, fentanyl, and epidural anesthesia. Propofol infusion rate was determined using the corrected body weight drawn by Servin et al. Anesthetic management and recovering from anesthesia were uneventful. For propofol anesthesia, infusion rates determined using the corrected body weigh, was preferable for morbidly obese patients.

Adult↗
PubMed2001

[Guillain-barré syndrome associated Campylobacter jejuni serotype Penner 2: a case report].

We described a 15-year-old male who had Guillain-Barré syndrome(GBS). Nine days after watery diarrhea, the patient developed pain and weakness of foot muscles. On admission, the nerve conduction studies revealed peripheral neuropathy with axonal degeneration and demyelination. Campylobacter jejuni(C. jejuni) with serotype of Lior 4, Penner 2 was isolated from his stool culture. IgM anti-GM 1 antibody and other various anti-ganglioside antibodies were detected in his serum. After receiving plasma exchange and intravenous immunoglobulin therapy, he was able to walk without assistance. In general, C. jejuni with the serotype Penner 19 has been isolated from many GBS patients. In this patient, C. jejuni with the serotype of Penner 2 was isolated. The serotype is detected commonly in Miller Fisher syndrome.

Adolescent↗
PubMed2001

[Novel biodegradable materials for drug delivery systems (DDS)].

The authors provide three new and different types of fibrin gels (FCs) and a chitosan sheet (BC) using an ultraviolet (UV)-crosslinking method. They are 1) FC-UV, 2) gelatin entrapped FC; FC (Gp)-UV, 3) chitosan entrapped FC; FC (Cs)-UV and 4) BC-UV. Each material was loaded with aqueous cis-platinum (CDDP), and both the degradation of the drug carriers and the release profile of the CDDP were examined in vitro. The FCs, 1)-3), gradually degraded and dissolved within 10-12 days. The BC, 4), maintained its original weight for more than 30 days. Each FC showed a sustained release of CDDP for 10 days, while BC provided an initial bursting of the loaded drug. New materials 2) and 3) show great potential as drug carriers for DDS and further in vivo studies are now proceeding.

Biodegradation, Environmental↗
PubMed2001

[A newly designed system, "FC-UV-CDDP", and a study of its oncolytic effect].

We devised a fibrin clot (FC) using an ultraviolet (UV)-crosslinking method. To evaluate the in vivo chemotherapeutic effects for cancer chemotherapy with our novel drug delivery system, the anticancer agent cis-platinum (CDDP) was impregnated into each FC and this "FC-UV-CDDP" was intraperitoneally (i.p.) administered to each ascitic hepatoma AH-130 in cancer-bearing rats. Other groups of AH-130 bearing rats, i.p. injected with CDDP or non-treated, served as the controls. We recorded the survival period of each animal and autopsied it at the time of death. All the animals treated with "FC-UV-CDDP" survived for more than 5 weeks and had no retention of ascites. Furthermore, all the surviving rats underwent a challenge with AH-130 cells. Two of 3 repeatedly challenged rats revealed no evidence of recurrence of the cancer and survived for more than 3 months. The control rats died of cachexia with a massive ascites within 2 weeks. Thus, our newly devised "FC-UV-CDDP" system favorably functioned in an experimental cancer model. These data suggested that this oncolytic effect was attributed to the possibility of inducing immune responses against AH-130 as well as to a sustained release of CDDP from FC.

Animals↗
PubMed2001

[Epiduroscopy in patients with chronic low back pain without remarkable findings on magnetic resonance imaging].

Two patients with chronic low back pain and sciatica failed to respond to conservative treatments. In these patients, magnetic resonance imaging (MRI) showed no remarkable findings corresponding to their symptoms. We treated these patients using epiduroscopy. Epiduroscopic visualization of the spinal canal permits efficient adhesiolysis and irrigation. One patient got better after two epiduroscopic procedures, and the other did not. Epiduroscopy may be an effective, minimally invasive treatment as well as examination for patients with chronic low back pain without remarkable findings on MRI.

Adult↗
PubMed2001

[An elderly woman with breast cancer and multiple liver metastasis that responded well to combination therapy of fadrozole and tamoxifen].

Few reports suggest a clinical benefit from combination treatment of fadrozole and tamoxifen for advanced breast cancer in elderly patients. We report the case of an 82-year-old breast cancer patient with multiple liver metastasis. After mastectomy, combination treatment of fadrozole and tamoxifen was added. Two months after the start of this treatment, there was a remarkable reduction in the size of metastatic lesions that continued over 6 months. CT examination revealed the largest lesion was reduced from 8.0 cm to 5.0 cm in largest diameter. The other two lesions were reduced from 3.0 cm to 2.0 cm. The reduction rate was 36%, indicating PR in the Response Evaluation Criteria in Solid Tumors (RECIST). The tumor marker CEA was remarkably reduced from 318 to 85 (ng/ml), and CA15-3 was reduced from 430 to 150 (U/ml). Tumor marker reduction continued over the 6 months corresponding to CT findings. No adverse effect was experienced. This combination therapy was useful and safe against metastatic breast cancer in a patient over 80 years of age.

Administration, Oral↗
PubMed2000

Involvement of the glucose-regulated protein 94 (Dd-GRP94) in starvation response of Dictyostelium discoideum cells.

Upon deprivation of nutrients, Dictyostelium discoideum Ax-2 cells arrest proliferation and initiate a metamorphosed developmental program including induction of altered gene expressions which are necessary for differentiation. In Ax-2 cells, we found out a member of Hsp90 family usually contained in the endoplasmic reticulum (ER), Dd-GRP94 (Dictyostelium discoideum glucose-regulated protein 94). In general, GRP94 are induced either by glucose-depletion or by depletion of Ca(2+) in intracellular Ca(2+) stores. Unexpectedly, however, the expression of Dd-grp94 was greatly reduced within 60 min of starvation. Dd-grp94-overexpressing cells (GRP94(OE) cells) collected without forming distinct aggregation streams, and never formed normal fruiting bodies. Also, prespore differentiation as well as maturation into spores and stalk cells were particularly impaired in the GRP94(OE) cells. Thus Dd-GRP94 seems to be crucial in late differentiation as well as in starvation response.

Amino Acids↗