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Biomedical subjects

H Iwama

Publications and source records attributed to H Iwama.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Placental transfer of vecuronium administered with priming principle regimen in patients undergoing cesarean section].

Eight women having cesarean section under general anesthesia received vecuronium (VCB) 0.01 mg.kg-1 as a priming dose, followed 180 s later by 0.11 mg.kg-1 as an intubation dose. Subsequently, VCB concentrations of umbilical venous and maternal arterial blood at delivery were assayed. The time from the injection of intubation dose to delivery was 283 +/- 55 (mean +/- SD) s. Umbilical and maternal VCB concentrations at delivery were 79.4 +/-36.1 1ng.ml-1 (UV) and 1258.3 +/- 464.1 ng.ml-1 (MA). respectively. Thus, the umbilical venous to maternal arterial VCB concentration ratio (UV.MA-1) was 0.07 +/- 0.02. One-min and 5-min Apgar scores were 8-9 and 9-10, respectively. Judging from previous reports concerning VCB administration during cesarean section, total of VCB 0.12 mg.kg-1 may be an overdose. We concluded therefore that of total VCB 0.10 mg.kg-1 seems to be an appropriate dose for cesarean section.

Adult↗
PubMed1997

Clinical implications of telomerase activity levels in acute leukemia.

In the present study, we used the telomeric repeat amplification protocol assay, an internal telomerase assay standard, and an automatic DNA sequencer to detect and quantitate telomerase activity in blood samples obtained from normal and acute leukemia patients. Telomerase activity was analyzed in 78 acute leukemia patients and ranged from 0.65 to 147 relative to the internal standard. Compared to the age-matched normal levels of telomerase activity in the peripheral blood cells, we determined that 45 (81.8%) of 55 acute myeloid leukemia (AML) and 16 (69.6%) of 23 acute lymphoid leukemia patients had elevated telomerase activity. There was no relationship between peak telomere length and telomerase activity in both acute lymphoid leukemia and AML patients. In AML, the level of telomerase activity was associated with French-American-British subtypes and cytogenetics, and patients with elevated telomerase activity had high leukocyte counts and more frequent extramedullary involvement during the disease. Among 78 patients, 5 had high levels of telomerase activities similar to immortalized leukemia cell lines; these 5 patients had a very poor prognosis (P < 0.05). The levels of telomerase activity significantly decreased in patients in complete remission. Most of the patients in complete remission showed a normal level of telomerase activity; however, two of them had low to moderate telomerase activity, and they relapsed shortly after entering complete remission. In relapsed patients, there is a general trend for increased telomerase levels, and 2 of the 13 patients retained high telomerase activity, whereas the other 11 had normal to moderate telomerase activity. These results suggest that telomerase activity may be a useful additional method for monitoring the disease condition in acute leukemia patients.

Adolescent↗
PubMed1996

Differential effects of phencyclidine and methamphetamine on dopamine metabolism in rat frontal cortex and striatum as revealed by in vivo dialysis.

We have examined the effects of schizophrenomimetic drugs including phencyclidine (PCP) and methamphetamine (MAP) on cortical and striatal dopamine (DA) metabolism using an in vivo dialysis technique in the rat. An acute systemic injection of PCP (2.5-10 mg/kg, intraperitoneally (i.p.)) dramatically increased concentrations of DA, 3,4-dihydroxy-phenylacetic acid, and homovanillic acid in the dialysates from the medial frontal cortex in a dose-dependent fashion. However, PCP (2.5-10 mg/kg, i.p.) caused a much lower augmentation of extracellular DA release, with a significant decrease in dialysate DOPAC levels in the striatum. Moreover, continuous infusion of tetrodotoxin (TTX, 10(-5) M) into the prefrontal or striatal region through the microdialysis tube completely blocked the ability of PCP (10 mg/kg, i.p.) to alter the extracellular release of DA and its metabolites in the respective areas. In contrast, MAP (4.8 mg/kg, i.p.) elicited a marked and tetrodotoxin-resistant increase in DA levels with a significant loss of DOPAC contents in the extracellular space of both the frontal cortex and the striatum. The present results clearly demonstrate the differential effects of PCP on cortical and striatal DA transmission, suggesting that PCP may facilitate DA release in the medial frontal cortex by increasing impulse flow in the DA neurons projecting to the cortical area, whereas PCP-induced elevation of extracellular DA in the striatum may be caused mainly by reuptake inhibition of DA liberated by basal activity of the striatal DA neurons. The regional variation in PCP-induced DA release would be due to the combination of NMDA (N-methyl-D-aspartate) receptor blocking and DA reuptake inhibition by the drug. The uniform and TTX-resistant nature of MAP-induced changes in brain DA metabolism may result from the direct actions of MAP at DA nerve terminals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

Near-hexaploid Ph-positive acute myeloid leukemia with major-BCR/ABL transcript.

We describe the first case of acute myeloid leukemia (AML) with a Philadelphia (Ph) translocation and a near-hexaploid range chromosome number, whose leukemic cells had the major-BCR/ABL transcript. The genesis of near-hexaploid leukemic cells might be due to endoreduplication of triploid leukemic cells with the Ph, since the relapsed leukemic cells had triploid range chromosomes with double Ph chromosomes.

Aneuploidy↗
PubMed1996

A possible correlation between interferon-stimulated gene expression and cytogenetic responses in chronic myelogenous leukemia patients treated with alpha-interferon.

We studied the expression of the interferon-stimulated genes (ISGs), ISG-54 and 2',5'-oligoadenylate synthetase (2'-5' OAS), using the reverse transcription-polymerase chain reaction in 22 patients with chronic myelogenous leukemia (CML), who were treated with alpha-interferon (alpha-IFN). At the time of diagnosis, 7 patients (31.8%) showed no detectable expression of either gene, whereas 8 expressed both. The remaining 7 expressed neither ISG-54 nor 2'-5' OAS. After alpha-IFN treatment, 5 of the 7 CML patients who had not previously express ISGs expressed either ISG-54 or 2'5' OAS or both and 6 of the 7 who had previously expressed either ISG-54 or 2'-5' OAS expressed both. Three of the 7 (42.9%) CML patients who expressed both genes before and after alpha-IFN administration showed cytogenetic responses, as did 6 of the 11 (54.5%) in whom ISG expression was induced. In contrast, cytogenetic responses occurred in none of the patients in whom ISG expression was not induced. These results suggest that induction of ISG-54 and 2'-5' OAS expression by alpha-IFN may be an indicator of cytogenetic responses and, therefore, of value for monitoring CML patients.

2',5'-Oligoadenylate Synthetase↗
PubMed1996

[A lower-leg ulcer during hydroxyurea therapy for essential thrombocythemia].

A skin ulcer of the lateral malleous developed in a 61-year-old man receiving hydroxyurea for essential thrombocythemia. In the past, skin ulcers have been reported in patients with chronic myeloproliferative diseases, including essential thrombocythemia, who had been treated with hydroxyurea. In the current case, vasculitis or thrombi in vessels of the biopsied specimen of the lower leg were not observed, and the patient required skin-graft operation. Accordingly, we concluded that the skin ulcer might be due to the administration of hydroxyurea. Thus, the dose of hydroxyurea was decreased.

Foot Ulcer↗
PubMed1996

Replication errors in hematological neoplasias: genomic instability in progression of disease is different among different types of leukemia.

Genetic alteration, including genomic instability, is an ultimate step toward the malignant process. One approach to delineating replication errors in cancer cells is to determine the alterations of microsatellites, which are short, repeated nucleotide sequences existing throughout the genomes. We used a fluorescent system to assess microsatellite changes in seven loci (D2S123, D3S643, D5S107, LPL, D17S261, TP53, and D18S34) of 73 consecutive patients with various hematological neoplasias. De novo acute leukemia patients had a low frequency (<1%) of microsatellite alterations at each locus, and none of them demonstrated multiple microsatellite changes. In chronic myeloid leukemia patients, no microsatellite instability was detected in the chronic phase, whereas a relatively high frequency (25%) of multiple microsatellite changes was evident in the blastic phase, and half of these patients had multiple microsatellite changes. About 50% of the patients with myelodysplastic syndrome (MDS) and post-MDS acute myeloid leukemia (post-MDS AML) had microsatellite alterations. We next compared microsatellite alterations in two different hematological phases (MDS and post-MDS AML phases); 5 of 11 patients with post-MDS AML had de novo appearance of microsatellite instability during disease progression. This indicates that genomic instability at multiple microsatellite loci could occur either before or after leukemic transformation in MDS patients. We concluded that genomic instability in chronic myeloid leukemia might be linked to blastic transformation in combination with cytogenetic changes. In contrast, MDS patients had replication errors as a relatively early genetic event as well as a late genetic event. These results suggest that the involvement of genomic instability in the progression of disease is different among various types of leukemia.

DNA Replication↗
PubMed1995

The expression pattern of erythrocyte/megakaryocyte-related transcription factors GATA-1 and the stem cell leukemia gene correlates with hematopoietic differentiation and is associated with outcome of acute myeloid leukemia.

To understand the clinical implications of transcription factors and their biologic roles during cellular differentiation in the hematopoietic system, we examined the expression of GATA-1, GATA-2, and stem cell leukemia (SCL) gene in human leukemia cell lines and various leukemia patients using the reverse transcriptase-polymerase chain reaction. Cell lines exhibiting megakaryocytic or erythrocytic phenotypes had GATA-1, GATA-2, and SCL gene transcripts, while monocytic cell lines had no detectable GATA-1, GATA-2, or SCL gene mRNA. In some myeloid cell lines, GATA-1 expression, but not SCL gene expression, was detected; GATA-1 expression in HL-60 cells was downregulated during the process of monocytic differentiation. We next examined GATA-1, GATA-2, and SCL gene expression in 110 leukemia samples obtained from 76 patients with acute myeloid leukemia (AML), 19 with acute lymphoblastic leukemia (ALL), and 15 with chronic myeloid leukemia in blast crisis (CML-BC). SCL gene expression was usually accompanied by GATA-1 expression and was preferentially detected in patients with leukemia exhibiting megakaryocytic or erythrocytic phenotypes, while patients with monocytic leukemia were clustered in the group with no detectable GATA-1 expression. None of the patients with ALL or CML-lymphoid-BC expressed SCL. De novo AML patients with SCL gene expression had a lower complete remission (CR) rate and had a significantly poorer prognosis. Among the patients with AML not expressing SCL, a high percentage of patients with CD7+ AML and CD19+ AML had detectable GATA-1, while patients with GATA-1-negative AML had the best CR rate (87.5%). Our results suggest that the expression pattern of transcription factors reflects the lineage potential of leukemia cells, and GATA-1 and SCL gene expression may have prognostic value for the outcome of patients with AML.

Acute Disease↗
PubMed1995

[The evaluation of cuff-occluded rate of rise of peripheral venous pressure (CORRP) for monitoring blood volume status].

Cuff-occluded rate of rise of peripheral venous pressure (CORRP) was evaluated for perioperative monitoring. We investigated the CORRP in 6 patients undergoing open laparotomy. These patients were given general anesthesia, and monitoring lines were inserted. Heart rate, blood pressure (BP), right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PAP), cardiac output (CO) and CORRP were monitored. CORRP is defined as the average rate (in millimeters of mercury per minute) of rise of peripheral venous pressure after proximal occlusion of that vein by a tourniquet (select pressure: 50 mmHg). In the actual measurement of CORRP, only the first 90% of the curve after occlusion of the tourniquet is used. CORRP correlated with RAP (r = 0.69 +/- 0.10), and PCWP (r = 0.79 +/- 0.07). On the other hand, there was no significant correlation between CORRP and BP, or PAP and CO. Snyder et al. described that CORRP seems to be an excellent indicator of acute volume change in the hyper- and hypovolemic canine model. We conclude that in these laparotomy patients, CORRP appears to be a sensitive and minimally invasive method of assessing volume status.

Aged↗
PubMed1994

Clavicular approach to intraosseous infusion in adults.

We attempted a clavicular approach to intraosseous infusion (clavicular IO) as a new procedure in adults, and compared the flow rates of subclavian venous infusion, and clavicular, iliac and tibial IO. Furthermore, we observed enhanced roentgenograms of each IO by contrast media. As a result, clavicular IO indicated 11.9 +/- 0.68 mL/kg/hr (mean +/- SD, n = 29), iliac IO 32.2 +/- 4.48 (n = 21), tibial IO 18.9 +/- 1.28 (n = 15), and subclavian venous infusion 15.2 +/- 1.48 (n = 15). There were no statistically significant differences between subclavian venous infusion and clavicular IO. In roentgenograms, the contrast media entered the inferior vena cava from iliac IO, and via the femoral vein by tibial IO. The superior vena cava was enhanced through the subclavian vein in clavicular IO. No complications such as fractures or transclavicular penetrations by the IO needle occurred. In conclusion, clavicular IO may be an alternative infusion technique to provide the fluids into the subclavian vein in adults.

Aged↗
PubMed1993

[Intrapleural regional analgesia in pain management after chest trauma].

Twelve chest trauma patients with severe pain were studied. All of them had multiple rib fractures, hemopneumothorax or pulmonary contusion, and needed the continuous chest drainage. 16 G epidural block catheter was introduced 20 cm into the apex of the pleural space. Furthermore, another catheter was placed into the base of the pleural space. After injecting 1% lidocaine 10 ml, the analgesic effect, the analgesic range according to injected point (apex or base), and the changes of vital signs, PaO2/FIO2 and PaCO2 were evaluated. The average pain scale before interpleural regional analgesia (IPA) was 2.9 and 1.0 after 15 min. The time to return to pre-IPA condition took about 150 min. The mean blood pressure did not show significant changes, although pulse and respiratory rate decreased. PaCO2 did not show significant changes, although PaO2/FIO2 increased significantly. The present study indicates that IPA in chest trauma reduces pain and improves PaO2/FIO2 significantly without circulatory changes. It was reported that it was difficult to obtain effective pain relief after thoracotomy. However, when the catheter is placed at the apex, it seems to be effective to relief pain on the chest site. In conclusion, IPA seems to be simple, effective and useful to remove pain from chest trauma when epidural block is difficult to induce.

Adolescent↗