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Biomedical subjects

M Hayakawa

Publications and source records attributed to M Hayakawa.

At least 55 records · Page 3Linked to original sources
PubMed2001

Diabetogenic activity of 20 kDa human growth hormone (20K-hGH) and 22K-hGH in rats.

To compare the diabetogenic activity of 20 kDa human growth hormone (20K-hGH) with that of 22K-hGH, we evaluated insulin sensitivity with a euglycaemic clamp in rats. The glucose infusion rate (GIR) in euglycaemic clamp studies was measured as an indicator of insulin sensitivity. [(14)C]glucose and 2-[(3)H] deoxy- D -glucose injection were used to calculate the rate of glucose utilization (R(d)), the hepatic glucose output (HGO), and the glucose metabolic index (R(g)'). Both 20K- and 22K-hGH were infused at equivalent rates (1.0 (mg/kg)/day). A 24 h infusion of 20K-hGH had no significant effects on the GIR, R(d), HGO and R(g)(')except for in gastrocnemius muscle. In contrast, 22K-hGH significantly lowered the GIR compared with the control (P< 0.001) and 20K-hGH groups (P< 0.01). The infusion of 22K-hGH also reduced R(d)compared with the controls and the 20K-hGH rats by 46.6% (P< 0.001) and 39.6% (P< 0.05) respectively, while no differences were observed in the HGO. Moreover, 22K-hGH inhibited glucose uptake, which was estimated from the insulin-stimulated R(g)' in some tissues. These results suggest that 22K-hGH inhibits the uptake and use of glucose in various tissues, which then leads to insulin resistance. In conclusion, the diabetogenicity of 20K-hGH is much weaker than that of 22K-hGH, and the reduced insulin-antagonizing action of 20K-hGH could have important clinical benefits.

Adipose Tissue↗
PubMed2001

Plasma and erythrocyte levels of trace elements and related antioxidant enzyme activities in low-birthweight infants during the early postnatal period.

UNLABELLED: To discover the relationship between antioxidant enzyme activities and trace elements in low-birthweight infants during the early postnatal period, we analysed catalase (CAT), CuZn-superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px) activities in erythrocytes. and compared them with Fe, Cu. Zn and Se levels in plasma, and Cu, Zn and Se levels in erythrocytes until 16 wk after birth. Thirteen low-birthweight infants whose mean birthweight and gestation were 1520 +/- 293 g and 32.0 +/- 2.8 wk were enrolled in this study. All infants were without chronic complications, well nourished, and predominantly fed standard formula or preterm formula based on cow's milk, commercially available in Japan. Cu and Zn levels in erythrocytes did not decline after birth, in contrast to a temporal decrease in plasma Zn. Erythrocyte CAT activity was significantly higher at 16 wk than that at birth or 4 wk of age. Erythrocyte CuZn-SOD activity did not change throughout the study period. Only Se in plasma and erythrocytes decreased remarkably after birth, which resulted in a significant decline in erythrocyte GSH-Px activity at 8 and 16 wk (11.2 +/- 2.0 and 11.0 +/- 1.1 U/g Hb) compared to that at birth (12.4 +/- 2.1 U/g Hb). CONCLUSION: During the early postnatal period. erythrocyte CAT and CuZn-SOD activities did not decrease in formula-fed, low-birthweight infants. Japanese commercial formula not supplemented with Se, however, caused postnatal plasma and erythrocyte Se deficiency and a concomitant decline in erythrocyte GSH-Px activity in the same subjects.

Catalase↗
PubMed2001

Application of Cre-loxP system to the urinary tract and cancer gene therapy.

The bacteriophage P1-derived Cre-loxP system is a powerful and versatile tool for in vivo DNA recombination. It is widely used in gene targeting research. The combination of the Cre-loxP system and a specific promoter enables conditional "knockout" of a target gene in a particular tissue or cell type. It has also made it possible to delete genes in adult animals that are essential for embryogenesis. This system is also used to enhance tissue- or tumor-specific promoter activities that are useful for gene therapy of certain types of cancer. It is expected that this simple and effective system will be further utilized in various research applications.

Animals↗
PubMed2001

Captopril restores transforming growth factor-beta type II receptor and sensitivity to transforming growth factor-beta in murine renal cell cancer cells.

PURPOSE: Captopril is known to inhibit the growth of renal cancer but the mechanism involved has been unclear. The current study elucidates the mechanism of captopril induced inhibition of the growth of the Renca mouse renal cancer cell line involving transforming growth factor-beta, which is known to be a growth inhibitory cytokine in epithelial cells and tissues. MATERIALS AND METHODS: Transforming growth factor-beta in conditioned medium was measured by bioassay. Levels of transforming growth factor-beta and transforming growth factor-beta type II receptor expression messenger RNA were determined by reverse transcriptase-polymerase chain reaction and flow cytometry. Cell viability was determined by bromodeoxyuridine (BrdU) incorporation and tetrazolium bromide assay. RESULTS: Captopril (0.01 to 1 mM.) showed no significant effect on transforming growth factor-beta synthesis or transforming growth factor-beta messenger RNA in Renca cells. On the other hand, 1 mM. captopril significantly inhibited Renca cell growth. Reverse transcriptase-polymerase chain reaction and flow cytometry showed that 1 mM. captopril up-regulated type II receptor expression. CONCLUSIONS: These findings suggest that captopril restores transforming growth factor-beta type II receptor expression and inhibits the growth of Renca cells by increasing their sensitivity to transforming growth factor-beta.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

A new genus of the order Actinomycetales, Virgosporangium gen. nov., with descriptions of Virgosporangium ochraceum sp. nov. and Virgosporangium aurantiacum sp. nov.

Four motile spored strains were isolated from soil samples collected in Japan. The cultures formed long, narrow sporangia on short sporangiophores directly on the substrate mycelium. The sporangia develop singly or in clusters above the surface of the substrate. Each sporangium contains a single row of six or more motile spores. Glutamic acid, glucosamine, glycine, alanine and 3-OH-diaminopimelic acid are present in the cell wall; the whole-cell sugars are 3-O-methylmannose, rhamnose, mannose, arabinose, galactose, xylose and glucose; and the predominant menaquinones are 10(H4), 10(H6) and 10(H8). The diagnostic phospholipid is phosphatidylethanolamine. The acyl type of the muramic acid is glycolyl. The G+C content is 71 mol%. Mycolic acids are absent. The chemotaxonomic data indicate that these strains belong to the family Micromonosporaceae. Analysis of 165 rDNA sequences suggested that these organisms fall into a distinct clade within the family Micromonosporaceae for which a new genus, Virgosporangium gen. nov., is proposed containing the species Virgosporangium ochraceum sp. nov. (strains YU655-43T, YU793-41 and YU794-41) and Virgosporangium aurantiacum sp. nov. (strain YU438-5T).

DNA, Ribosomal↗
PubMed2001

Background electroencephalographic (EEG) activities of very preterm infants born at less than 27 weeks gestation: a study on the degree of continuity.

AIMS: To clarify the features of the background electroencephalographic (EEG) activities in clinically well preterm infants born at less than 27 weeks gestation and to outline their chronological changes with increasing postconceptional age (PCA). METHODS: EEGs of clinically well premature infants born at less than 27 weeks gestation were recorded during the early postnatal period. The infants were separated into three groups according to their PCA at the time of EEG recording (21-22 weeks PCA, 23-24 weeks PCA, and 25-26 weeks PCA). The mean and maximum duration of interburst intervals (IBIs), the mean duration of bursts, and the percentage of continuous and discontinuous patterns in each PCA group were evaluated. RESULTS: There were three infants at 21-22 weeks PCA, seven at 23-24 weeks PCA, and five at 25-26 weeks PCA. Eighteen EEG recordings were obtained. The mean and maximum IBI duration decreased with increasing PCA. The percentage of continuous patterns increased with increasing PCA. Conversely, the percentage of discontinuous patterns decreased with increasing PCA. CONCLUSIONS: In premature infants born at less than 27 weeks gestation, the characteristics of the background EEG activities were similar to those of older premature infants. These changes reflect the development of the central nervous system in this period.

Analysis of Variance↗
PubMed2001

Liposome-mediated gene therapy using HSV-TK/ganciclovir under the control of human PSA promoter in prostate cancer cells.

To more accurately determine the tissue-specific expression of the target gene in prostate cancer cells, we introduced the enhancer element (-4,777 to -3,934; PSAR) and the promoter region (PSAP) of the prostate-specific antigen (PSA) gene. Furthermore, to elucidate the advantages of using liposomes as a gene carrier, we screened more than 20 liposome preparations in this study. The 5' upstream region of PSA gene (PSARPSAP) was conjugated to either the chloramphenicol acetyltransferase (CAT) gene or herpes simplex virus thymidine kinase (TK) gene, and the transfection of these plasmids was carried out using cationic liposomes, DMRIE-C (Gibco) or LipoTAXI (Stratagene). The expression of CAT activity was clearly observed when PSARPSAP-CAT plasmid was transfected into PSA-positive LNCaP cells, whereas no CAT activity was detected in PSA-negative DU145 cells or bladder carcinoma T24 cells. The CAT activity increased after the addition of testosterone. We then evaluated the therapeutic effect of the PSARPSAP-TK plasmid in vitro. When PSARPSAP-TK plasmid was transfected and ganciclovir was added to the medium, the growth of LNCaP cells was inhibited, while no growth inhibition was observed in DU145 cells. Furthermore, this inhibitory effect was observable even when the cells were cultured in a medium supplemented with dialyzed fetal bovine serum. These results suggest that the liposome-mediated transfection of PSARPSAP-TK appears to be a potentially effective approach for selecting the optimal treatment for tumor cells producing PSA even with the low androgen levels seen in patients treated by anti-androgen therapy.

Ganciclovir↗
PubMed2001

Purification and characterization of an oligo-isomaltosaccharide synthase from a Streptococcus sobrinus glucosyltransferase-I deficient mutant.

One glucosyltransferase (GTF) -I deficient mutant of Streptococcus sobrinus strain B13N was isolated through chemical mutagenesis with ethyl methanesulfonate, and characterized. This mutant, designated as B13N-Id, readily allowed us to purify a homogeneous oligo-isomaltosaccharide synthase (GTF-S) from its culture fluid. The purified GTF-S was only recognized with rabbit polyclonal antibody against recombinant GTF-S from an Ecsherichia coli MD124 clone expressing the B13N gtfS gene, and showed the almost same enzymatic properties as the recombinant enzyme. A double reciprocal plot of the B13N GTF-S for sucrose was biphasic, and the affinity for this substrate was high compared to that of GTF-S enzymes from other strains.

Chromatography, High Pressure Liquid↗
PubMed2001

Construction of a chimeric shuttle plasmid via a heterodimer system: secretion of an scFv protein from Bacillus brevis cells capable of inhibiting hemagglutination.

Passive immunization is an attractive therapy for preventing oral diseases including dental caries and periodontal disease. For this purpose, we attempted to produce a single chain variable fragment, scFv, which inhibited hemagglutination using the Bacillus brevis protein-producing system. To accomplish this, a novel strategy, a heterodimer system, was used for the construction of a chimeric shuttle plasmid. Initially, a set of new plasmids, kanamycin-resistant donor and erythromycin-resistant general cloning plasmids, were constructed. p15A ori was a common replication origin in these plasmids, while the pUB110 rep and minus origin (MO) were cloned into the donor plasmid. Next, the secretion domain of the B. subtilis alpha-amylase gene and the G2-4 gene, coding for the scFv protein, were cloned into the general cloning plasmid and fused by PCR. Both the donor plasmid and the general cloning plasmid containing the fused gene were digested with NotI and them ligated, a dimeric plasmid being constructed. The key restriction sites, AscI, are arranged such that the pUB110 rep-MO moiety was switched from the donor to the general cloning plasmid following AscI digestion. The chimeric shuttle plasmid was readily constructed by simple re-circularization and a B. brevis transformant producing the scFv protein in the culture fluid was isolated.

Amino Acid Sequence↗
PubMed2001

Operable non-small cell lung cancer diagnosed by transpleural techniques : do they affect relapse and prognosis?

STUDY OBJECTIVE: We assessed whether transpleural methods for diagnosing peripheral lung cancer, such as needle aspiration or tumor excision, affect relapse and prognosis, because these techniques have potential to spread malignant cells from the tumor. DESIGN: A retrospective study. SETTING: National referral hospital. PATIENTS: We reviewed 239 patients who underwent surgery between 1990 and 1998 and for whom non-small cell lung cancer (NSCLC) of < 3 cm in maximum diameter was completely resected. The duration of postoperative follow-up ranged from 12 to 105 months, with a median period of 45 months. INTERVENTIONS: We defined the transbronchial method as using a bronchoscope, and the transpleural method as using needle aspiration cytology or tumor excision. Dichotomous variables included gender, histologic type of squamous cell carcinoma or other type of carcinoma, pathologic stage, and whether the diagnostic method was the transbronchial type only (first-line method) or the transpleural type (second-line method). RESULTS: NSCLC was diagnosed in 45 patients by the transpleural technique and in 194 patients by the transbronchial technique. There were no significant statistical differences in age of patients, gender, histologic type, pathologic stage, and tumor size. There were 42 relapses, 7 in the transpleural technique group and 35 in the transbronchial technique group (p = 0.90). Of the 7 patients in the transpleural group, there were 4 distant metastasis and 3 local relapses; of the 35 patients in the transbronchial group, there were 20 distant metastasis and 15 local relapses (p = 0.99). Pleural carcinomatosis occurred in none of the 45 patients in the transpleural group and in 1 case (0.5%) in the 194 patients in the transbronchial group (p = 0.99). Patients in the transpleural group had a statistically better 5-year survival rate than patients in the transbronchial group (79.4% vs 60.3%, p = 0.04). This is also confirmed as an independent prognostic factor in a multivariate analysis. CONCLUSIONS: Transpleural methods seem to be an advisable way to diagnose operable lung cancer that is difficult to diagnose using bronchoscopy, because these methods did not affect relapse and prognosis in the patients in our study.

Adult↗
PubMed2001

A sensitive method for detecting Porphyromonas gingivalis by polymerase chain reaction and its possible clinical application.

BACKGROUND: It is useful for the clinical diagnosis of periodontitis to monitor the colonization of periodontopathic bacteria in periodontal pockets. In this study, we attempted to establish and possibly identify the clinical application of a sensitive method to detect Porphyromonas gingivalis (P.g.), one of the putative periodontopathic bacteria related to chronic periodontitis. METHODS: Genomic DNA extracted from cultured P.g. 381 and clinically isolated subgingival plaque samples were used as a template of polymerase chain reaction (PCR). We designed primers to amplify the genomic DNA coding 40 kDa outer membrane protein (OMP), one of the unique proteins to all strains of P.g. The efficiency and specificity of amplification were evaluated by agarose gel electrophoresis and subsequent Southern hybridization with a digoxygenin-labeled oligonucleotide probe. RESULTS: Fewer than 100 P.g. bacterial cells in the specimen were reproducibly detected by PCR-hybridization assay. This PCR-hybridization assay was at least 100 times more sensitive than the conventional indirect immunofluorescence assay (IIF). Furthermore, the imaging analysis showed that there is a linear correlation between the strength of the signal and the cell number of P.g. from which the template DNA was extracted semiquantitatively. It is noteworthy that the PCR assay could also be applied to detect P.g. from clinical plaque samples and that it was approximately 100 times more sensitive than a conventional IIF assay. CONCLUSION: The PCR assay established in this study can be a powerful tool to detect P.g. in periodontal pockets and monitor the colonization and/or recolonization of P.g. at the very early phase.

Bacterial Outer Membrane Proteins↗
PubMed2001

Identification of 40-kDa outer membrane protein as an aggregation factor of Porphyromonas gingivalis to Streptococcus gordonii.

Porphyromonas gingivalis, an important pathogen in periodontitis, aggregates with other oral microorganisms such as Streptococcus gordonii. We previously succeeded in gene cloning the 40-kDa outer membrane protein (OMP) from P. gingivalis. Although recombinant (r) 40-kDa OMP itself did not show aggregation activity, the affinity-purified antibody against 40-kDa rOMP inhibited the aggregation activity of P. gingivalis cells toward S. gordonii which is one of the first oral bacteria to colonize on tooth surfaces and can be expected to support subsequent colonization of other bacteria. In this study, in order to clarify the pathological role of 40-kDa OMP, we used a cross-linking reagent to construct a polymeric form of r40-kDa OMP and examined its aggregation activity. The polymeric r40-kDa OMP significantly expressed aggregation activity with S. gordonii cells. Moreover, the antibody against r40-kDa OMP inhibited the aggregation activity of the polymeric r40-kDa OMP. These findings clearly demonstrate that 40-kDa OMP, as a multivalent form, is one of the important aggregation factors on the cell surface of P. gingivalis.

Antibodies↗
PubMed2001

[Immunohistochemical study of p53 and Ki-67 overexpression in grade 3 superficial bladder tumor in relationship to tumor recurrence and prognosis].

PURPOSE: The major drawback of the current treatment for superficial bladder tumor is the high rate of recurrence. Especially, the tumor with grade 3 component has a tendency to recur and progress in stage. However, we have difficulty in predicting tumor recurrence and stage progression accurately by conventional clinicopathological factors. We evaluated the efficacy of p53 and Ki-67 overexpression as a predictor of recurrence or prognosis in patients with superficial bladder tumor of grade 3. MATERIALS AND METHODS: Samples were obtained from 41 patients with superficial transitional cell carcinoma of the bladder of grade 3 who were treated by transurethral resection (TUR). The immunohistochemical study was performed using the antibodies against the p53 protein and Ki-67 antigen on formalin-fixed, paraffinembedded tissue specimens from initial tumors. We evaluated the correlation between these results and several clinicopathological factors. RESULTS: The p53 index and the Ki-67 index in pTa, pT1a and pT1b tumors were 26.4 +/- 30.1%, 28.6 +/- 30.0%, and 34.6 +/- 32.6% (p53) and 20.5 +/- 22.5%, 20.0 +/- 29.3%, and 29.2 +/- 28.4% (Ki-67). There was no significant difference between the each index and tumor stage. Eighteen cases (43.9%) had intravesical recurrence. The p53 index of the initial tumor from the tumor free cases (n = 23), recurrent cases without stage progression (n = 12), and stage progression cases (n = 6) were 19.7 +/- 28.2%, 42.0 +/- 28.7%, and 42.5 +/- 32.0%. Between the recurrence-free cases and the recurrent cases without progression, the p53 index of the initial tumor had statistical significance (p < 0.05). The Ki-67 index was shown to be the same pattern as the p53 index, but there was not statistical significance. Four of patients with stage progression had tumor progression within six months. Three of the patients with tumors with stage progression died of the cancer. In multivariate analysis, tumor multiplicity (p = 0.01), BCG intravesical instillation (p = 0.04), p53 index (p = 0.01) and Ki-67 index (p = 0.02) were the positive risk factors for tumor recurrence, but only the p53 index was the positive risk factor for prognosis fo the patients (p = 0.03). CONCLUSION: These results suggest that the immunohistochemical study of p53 overexpression is a useful predictor for tumor recurrence and prognosis in patients with superficial bladder tumor with grade 3.

Adult↗
PubMed2001

[Clinical efficacy of leuprolide acetate and combined treatment with estramustine for advanced prostate cancer].

BACKGROUND/PURPOSE: Twenty-two institutes have organized Keio University Prostate Cancer Study Group to study clinical efficacy and safety of Leuprolide acetate (Leuplin) for the treatment of advanced prostate cancer (clinical stage D1 and D2). Cotreatment of Leuplin and Estramustine phosphate disodium (Estracyt) has been performed to investigate its clinical efficacy. MATERIALS AND METHODS: One hundred and two cases of advanced prostate cancer were treated either with Leuplin alone (group I), Leuplin and Estracyt (group II) or Estracyt alone (group III). After 12 weeks treatment, clinical effects against subjective symptoms (pain, voiding difficulty, performance status and body weight), serum testosterone level, tumor size and serum PSA level were examined to investigate short-term effect of each treatment. The treatment had been continued for 24 months and the treatment effects including progression free survival and overall survival were analyzed. RESULTS: Clinical efficacy after 12 weeks treatment were examined among 97 cases (group I; 35 cases, group II; 36 cases, group III; 26 cases). The background of those patients in each group was statistically equal. Treatment effects against subjective symptoms and serum testosterone level statistically revealed no significant difference among 3 groups. Treatment effects against primary tumor, bone metastatic lesion, lymphnode metastatic lesion and serum PSA level were investigated and anti-tumor effect was characterized by total efficacy rate (complete remission rate plus partial remission rate) of each treatment group. Treatment efficacy rates for each lesion and PSA demonstrated no statistical difference among 3 treatment groups. Total efficacy rate of group I, II and III were 88.2%, 84.0% and 78.3%, respectively, which statistically revealed no significant difference. Total efficacy rate of each group after completing 24 months treatment was; group I 80.0%, group II 55.6% and group III 83.3%, which statistically showed no significant difference among 3 treatment groups. The median day for progression free survival of group I, II and III were 661, 731 and 517, respectively. The overall survival rate of group I, II and III after completing 24 months treatment were 77.5%, 83.0% and 72.4%, respectively. Both progression free survival rates and overall survival rates revealed no significant difference among 3 groups. Side effects during 24 months treatment were seen in 8.6% of group I, 47.2% of group II and 26.9% of group III, and these occurrence rates were significantly different among the groups (p = 0.0013). CONCLUSION: Although number of the cases had not been able to continue the treatment for their side effects, the statistical characterization demonstrated that cotreatment of Leuplin and Estracyt had no greater treatment effect than monotreatment of each drug.

Aged↗
PubMed2001

Tranilast ameliorates renal tubular damage in unilateral ureteral obstruction.

PURPOSE: We determined whether tranilast, the anti-allergic agent N-(3, 4-dimethoxyciannamoyl)-anthranilic acid, would diminish renal transforming growth factor-beta (TGF-beta) levels in unilateral ureteral obstruction and concomitantly affect renal tubular apoptosis and proliferation in that condition. MATERIALS AND METHODS: Tranilast (150 mg./kg.) was administered to rats 1 day before unilateral ureteral obstruction and each day thereafter. Kidneys were harvested day 14 after unilateral ureteral obstruction. Tissue TGF-beta was measured by bioassay using mink lung epithelial cells. Renal tubular proliferation and apoptosis were detected by immunostaining proliferating cell nuclear antigen and the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay, respectively. Fibrosis was assessed by measuring collagen deposition with trichrome stained slides. RESULTS: TGF-beta bioassay showed that obstructed kidneys in controls contained significantly higher mean TGF-beta plus or minus standard deviation than unobstructed kidneys in controls (73.7 +/- 13.6 versus 14.1 +/- 5.5 pg./mg. tissue) and tranilast significantly decreased tissue TGF-beta in obstructed kidneys (15.9 +/- 4.8 pg./mg. tissue). The terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay demonstrated that obstructed kidneys in controls had significantly more mean tubular apoptosis than the unobstructed counterparts (36.6 +/- 6.7 versus 5.8 +/- 5.5 nuclei per high power field) and tranilast significantly decreased mean renal tubular apoptosis in obstructed kidneys (16.2 +/- 1.7 nuclei per high power field). In addition, immunostaining proliferating cell nuclear antigen showed that obstructed kidneys in controls had significantly more mean renal tubular proliferation than unobstructed kidneys (20.7 +/- 3.4 versus 6.2 +/- 2.1 per high power field) and tranilast significantly increased proliferating renal tubules in obstructed and unobstructed kidneys (26.5 +/- 8.3 and 14.5 +/- 3.4 per high power field, respectively). Control obstructed kidneys exhibited significantly more fibrosis, which was also blunted by tranilast. CONCLUSIONS: Tranilast significantly decreases tissue TGF-beta, resulting in a reduction in tubular apoptosis and an increase in tubular proliferation. This finding suggests that tranilast is a promising agent for preventing renal tubular damage in unilateral ureteral obstruction.

Animals↗
PubMed2001

Pathological evaluation of venous emboli during total hip arthroplasty.

One of the possible causes of bone cement implantation syndrome during total hip arthroplasty is pulmonary embolism, as has been suggested by a characteristic image seen during transoesophageal echocardiography, the so-called 'Snow Flurry'. However, the nature of the embolic material has not been definitively determined. We studied seven patients undergoing cemented or uncemented total hip arthroplasty. 'Snow Flurry' images were detected in all patients. Blood was aspirated from the right atrium during 'Snow Flurries' and was subjected to pathological examination. Amorphous, eosinophilic, fine granular material was seen in all specimens. The material did not originate from cement. Fat and bone marrow were not detected. The material seen may consist of fine particles of bone ('bone dust') originating from reamed bone.

Adult↗
PubMed2001

[Extraction of di-2-ethylhexyl phthalate from a cardiopulmonary bypass circuit].

We measured levels of di-2-ethylhexyl phthalate (DEHP) in a priming solution of a cardiopulmonary bypass circuit. The circuit consisted of a venous reservoir, an oxygenator, and polyvinyl chloride (PVC) tubes. Eight circuits were used in this study. In 4 circuits a heparin-coating PVC tube was used and, in the others, a non-coating PVC tube. After they were primed with 1,500 ml of saline, the saline was circulated for 30 minutes at a rate of 6 l/min at 42 degrees C. Another four samples were collected directly from the saline in a polyethylene container as a control. Then the concentrations of DEHP in them were determined by means of gas chromatography. No detectable DEHP was found in controls. But, a small amount was detected in the saline from the circuits (2.75 +/- 4.27 ppb, and 3.75 +/- 4.99 ppb, respectively). DEHP was considered to be leached from the circuit to the priming solution because the tubes were made of PVC containing DEHP as a plasticizer. We suppose the DEHP concentration is probably at a safe level. However, the data on the endocrinologically toxic level of blood DEHP are insufficient. Therefore, the use of plastic in a circuit may require closer scrutiny to determine whether DEHP leached from PVC contributes to exposure to xenoestrogens.

Cardiopulmonary Bypass↗