Search PubMed⌕ Search

Biomedical subjects

H Doi

Publications and source records attributed to H Doi.

At least 235 records · Page 13Linked to original sources
PubMed1990

[In vitro metal dissolution under various extraction conditions].

Dissolution of components from pure Ni, pure Ti, NiTi alloy and 316 L stainless steel was examined in Eagle's minimum essential medium to evaluate the effects of dynamic condition, pH, extraction period and filtration on the corrosion behaviour. Extraction medium was pH 3.5, 7.0 and 9.5. Extraction was done under static and gyrating conditions of 160 rpm, 200 rpm and 230 rpm for 3 and 7 days. Under static conditions, nickel was eluted from pure Ni and NiTi alloy at pH 3.5. Nickel and iron were slightly eluted from 316 L stainless steel at pH 3.5. However, dissolution of components from alloys was greater under dynamic conditions and with longer extraction periods. Dissolution of components, particularly of nickel at pH 3.5, was the highest from pure Ni, NiTi alloy and 316 L stainless steel. Following filtration with a 0.22 micron filter, the amount of metal decreased. Titanium was not detected in the filtrate under the conditions tested. The finding that a considerable amount of nickel was detected in the extract and filtrate indicated that the element was present in both a soluble and particulate form, especially at pH 3.5. The present results demonstrate that extraction under dynamic conditions is useful for investigating the degradation of metallic materials for medical and dental use.

Corrosion↗
PubMed1990

[Coronary artery bypass in dextrocardia with situs inversus totalis--a case report].

A 71-year-old woman was admitted to our hospital by ambulance, because of right chest pain and hypotension. Chest X-ray and standard 12-lead ECG showed mirror-image dextrocardia with situs inversus totalis. ECG with right-left reversal of all leads showed acute inferior myocardial infarction. The patient underwent coronary bypass surgery due to postinfarction angina, and she is now doing well 2 years following the operation. Mirror-image dextrocardia with situs inversus totalis is very unusual. But the patients are believed to have normal longevity, and presumably have an incidence of atherosclerotic coronary artery disease similar to the general population. To our knowledge, this is the first case of coronary bypass surgery on a patient with mirror-image dextrocardia in Japan.

Aged↗
PubMed1990

[Effects of negative extra-thoracic pressure ventilation on respiratory system and hemodynamics in normal dogs].

The effects of negative extra-thoracic pressure ventilation (NETPV) on respiratory system and hemodynamics were examined in ten normal dogs. Changes of the parameters obtained during intermittent NETPV (INETPV), and NETPV with negative end-expiratory pressure (CNETPV) were compared with those during IPPV and CPPV. Animals' chests and upper abdomens were confined in an acryl box. In INETPV and CNETPV, the dogs were ventilated with the negative extra-thoracic pressure ventilator (Kimura, OKT-100). Positive and negative pressure ventilation was carefully matched for tidal volume and the increase in FRC obtained with PEEP and the end-expiratory negative extra-thoracic pressure (EENETP). EENETP of -11.6 cmH2O produced the same FRC change as PEEP of 10.6 cmH2O did. Gas exchanges did not differ in any modes. INETPV did not change any hemodynamic parameters without PAP. In CNETPV, heart rate increased, and CVP, cardiac index (CI) and stroke volume (SV) decreased significantly (P less than 0.05), but tmCVP and tmPCWP did not change. The decreases of CI and SV (100----89.1, 88.8%) in CNETPV were significantly smaller when compared with CPPV (100----78.8, 74.5%). In CPPV, meanBP, CVP, tmCVP, tmPCWP, CI, SV changed significantly. The mechanisms of the decrease of CI and SV by CNETPV seemed to be different from those by CPPV.

Animals↗
PubMed1990

[Coronary artery bypass grafting for a very rare run off case of superdominant left anterior descending artery].

A superdominant left anterior descending artery (LAD) was found in a 59-year-old man who had electrocardiographic evidence of acute anterior and inferior wall myocardial infarction. Coronary cineangiography showed 95% stenosis at segment 7 of LAD which extended around the apex, ascending into the posterior interventricular sulcus to the crux and ran to the left into posterior atrioventricular sulcus. Posterior descending artery was not provided by the left circumflex artery or the right coronary artery. Multiple infarction due to proximal disease of such a superdominant LAD is very rare in pathoanatomically. Coronary artery bypass grafting to the LAD using left internal mammary artery was performed. The patients is now doing well with no anginal attack, 18 months following the operation.

Coronary Artery Bypass↗
PubMed1990

[Effects of negative extra-thoracic pressure ventilation on extravascular lung water volume and central blood volume in normal dogs].

In negative extra-thoracic pressure ventilation (NETPV), lung water volume and central blood volume (CBV) could increase because of increased venous return and intensified negative interstitial pressure. The effects of NETPV on the extravascular lung water and CBV were examined in ten normal dogs by the double-indicator method using Na and cold water. The lung water volume measured by the method (EVTV) was compared with the lung water volume measured by the gravimetric method (EVLW) in 17 dogs. EVTV did not show any significant change in any ventilation modes compared with IPPV. CBV decreased from 21.9 ml.kg-1 to 19.2 ml.kg-1 in CPPV compared with IPPV (P less than 0.05). EVTV correlated well (r = 0.91, P less than 0.001) with EVLW. In normal dogs, NETPV did not change the lung water volume and CBV. NETPV dogs do not seem to have any disadvantage in respect of lung water volume compared with conventional positive pressure ventilations.

Animals↗
PubMed1990

[The measurement of extra vascular lung water using a thermal-sodium double indicator dilution technique in patients undergoing surgery for esophageal cancer].

The Extra Vascular Lung Water (EVLW) was measured using the thermal sodium double indicator dilution technique in 21 patients undergoing surgery for esophageal cancer. This measurement is an important parameter in the control of the respiratory function. In the 16 cases without pulmonary complications, the preoperative EVLW was 5.3 +/- 0.2 (mean +/- SEM) ml/kg and the immediate postoperative EVLW was 4.8 +/- 0.4 ml/kg. This change was significant (p less than 0.05), but within 24 hours the EVLW returned to almost the same levels as those recorded before surgery. In only 3 cases, the EVLW were elevated beyond 7.5 ml/kg, but these high EVLW levels did not continue for more than 12 hours. Of the 5 patients with pulmonary complications, only two experienced pulmonary edema. Their preoperative EVLW levels were normal, but the immediate postoperative EVLW levels were significantly elevated beyond 10 ml/kg. These elevated levels were observed before the PaO2, the portable chest roentgenograms and the other test results changed following surgery. The high EVLW levels beyond 7.5 ml/kg continued for 72 hours after surgery. We found no correlation between the EVLW and measureable hemodynamic parameters (Cardiac Index, Pulmonary Wedge Pressure, Colloid Osmotic Pressure-Pulmonary Wedge Pressure gradient) during the observation period. In the other cases with pulmonary complications (2 cases were pneumonia, one was atelectasis with pneumonia), the changes in the EVLW levels were the same as for the cases without pulmonary complications. These results indicate that the EVLW is the optimum parameter for the control of the respiratory function and early diagnosis of pulmonary edema after surgery for esophageal cancer.

Esophageal Neoplasms↗
PubMed1990

Prevention of mother-to-child transmission of human T-lymphotropic virus type-I.

Human T-cell lymphotropic virus type I (HTLV-I), an etiologic human retrovirus of adult T-cell leukemia/lymphoma (ATLL), causes approximately 60 new cases of ATLL each year in Nagasaki Prefecture; essentially all cases are fatal, and they account for approximately 0.5% of total deaths in the area. The estimated life risk for an HTLV-I carrier to develop ATLL is approximately 5%. The major transmission pathway of HTLV-I peculiarly endemic in the Nagasaki Prefecture was studied. The prevalence of HTLV-I infection in children of carrier mothers (21%) was significantly higher than that in children in the general population in the area (1%) and more than 85% of mothers of carrier children were carriers. The breast milk of carrier mothers contained HTLV-I-infected cells and was infectious for marmoset via oral administration. A retrospective survey of children of carrier mothers showed that the prevalence of carrier children of carrier mothers was 17 (39%) of 44 and 0 (0%) of 10 when they were given breast milk only or formula only, respectively. These data provide a powerful basis for devising an intervention measure to block the endemic cycle of HTLV-I, ie, if carrier mothers refrain from breast-feeding, the incidence of ATLL will be significantly reduced some 50 years later.

Adolescent↗
PubMed1990

[Comparison of intraocular penetration level of cefuzonam sodium and cefotiam after intravenous and subconjunctival injection].

We investigated the intraocular penetration of a new Cephem type antibiotic: Cefuzonam sodium (CZON) following intravenous and subconjunctival injection. CZON was administered to 28 eyes in 26 patients by 1 g intravenous injection (IV) and to 11 eyes in 10 patients by 20 mg/0.2 ml subconjunctival injection (SCI). The penetration level of CZON by the IV method was from less than 0.0025-3.35 micrograms/ml into aqueous humor, from less than 0.0025-0.315 microgram/mg into iris tissue and 2.7-157.5 micrograms/ml into serum. The penetration level of CZON by the SCI method was from less than 0.0025-12.8 micrograms/ml into aqueous humor, from less than 0.0025-0.0426 microgram/mg into iris tissue and 1.03-18.5 micrograms/ml into serum. The penetration level of CZON into aqueous humor by SCI was higher than by IV administration. In comparison with the penetration level of CZON and Cefotiam (CTM), both aqueous humor and serum levels of CTM were higher than those of CZON. These results suggested that therapeutic levels in aqueous humor effective against gram-positive and gram-negative pathogens were achieved with the 1 g IV and 20 mg SCI of CZON. However levels effective against Staphylococcus epidermidis were only erratically attained.

Adult↗
PubMed1990

[A case of gastric lipoma diagnosed preoperatively].

A case of gastric lipoma seen in a 57-year-old-woman was reported. UGI, endoscope, CT, MRI and EUS revealed a tumor, which showed typical findings of this disease. Above all, EUS findings correlated well with the cut surface of the operative specimen.

Female↗
PubMed1989

The preoperative use of extra-tissue expander for syndactyly.

To our knowledge, this is the first report of a method of stretching the interdigital skin of syndactyly by means of a pincer. The pincer, a U-shaped metal spring plate with a sponge cushion, is applied before the operation for about two months; pressure is placed against both sides of the interdigital fusion to expand the skin and to develop hollows. Use of the pincer facilitates a syndactyly operation by allowing defect coverage with a local flap only. Four patients successfully treated by this method are reported. The method has the great advantage of not requiring skin grafts, which often have unfavorable results both functionally and cosmetically.

Child↗
PubMed1989

[Studies on the clinical and bacteriological effects of ofloxacin on the typhoid patients and carriers].

Fundamental and clinical studies of OFLX were performed against the patients with typhoid fever and typhoid carriers. 1) Clinical and bacteriological effects: Eight patients with typhoid fever and 3 typhoid carriers were treated with OFLX. Daily doses of the agent were 900 mg in 5 adult patients, 600 mg in a child patient and 3 adult carriers. In one case of the remaining 2 adult patients, daily doses of the agent changed from 800 mg to 1200 mg and from 900 mg to 1200 mg in the other one. The duration of the treatment was 9, 14 or 21 days. Clinical efficacies of OFLX against the patients proved 4 cases were "excellent", 3 cases were "good" and one case was "poor". The eradication of Salmonella typhi recognized in all cases containing 3 carriers with the exception of the "poor" case. Adverse reactions were observed transiently in 3 patients, such a slight decrease of RBC count, decrease of granulocyte count and elevation of GPT value respectively. 2) Antimicrobial activity: MICs of OFLX against 40 strains of S. typhi were 0.05 micrograms/ml and 0.1 micrograms/ml. The MICs of NFLX, CPFX and T-3262 were almost the same as that of OFLX, and those of ENX, NY-198 and NA were higher than that of OFLX. The peaks of MIC of CP and ABPC, first choice drug against typhoid fever, were 1.56 micrograms/ml and 0.38 micrograms/ml respectively. 3) Serum concentration; Serum concentrations of OFLX were serially measured on 5 patients through the day. The concentrations of the drug were distributed from 0.82 micrograms/ml to 6.34 micrograms/ml at 6.30 a.m. and from 2.52 micrograms/ml to 11.2 micrograms/ml at 9:00 p.m. Those of the day time showed considerable individual differences.

Adult↗
PubMed1989

Dental casting of titanium and Ni-Ti alloys by a new casting machine.

The purpose of this study was to develop a new casting machine for titanium and Ni-Ti alloys. Properties of cast pure titanium and Ni-Ti alloys were studied by means of the tensile and casting tests. As gas in the mold was removed by the mold being heated under a high vacuum, the reaction between the molten metal and the mold decreased. The new control system and the two types of crucibles developed proved very useful for prevention of internal macro-defects in castings and for improvement of castability. Mechanical properties and castability of pure titanium were improved. Ni-Ti alloys could be cast without loss of their shape-memory effect or super-elasticity characteristics. The new casting machine is thought to be promising for the casting of titanium and Ni-Ti alloys. Furthermore, we can cast these alloys using conventional techniques and investments.

Dental Alloys↗
PubMed1989

[Intraoperative radiation therapy for malignant glioma].

Intraoperative radiation therapy (IOR) is an ideal means of exterminating residual tumor after surgical resection. In this study, the clinical results of IOR using a Scanditronix Microtron MM-22 were evaluated in 14 patients with malignant glioma, five of whom had recurrent tumors. Between July, 1985 and October, 1986, 11 patients with glioblastoma multiforme (GB) were irradiated 18 times (mean, 1.6 times/case), and three with astrocytoma (Kernohan grade III) underwent IOR once each. The target-absorbed dose at 1 to 2 cm deeper than the tumor resection surface was 15 to 50 Gy. During irradiation, a cotton bolus was placed in the dead space after over 91% of the tumor had been resected. As a rule, external irradiation therapy was also given postoperatively at a dose of 30 to 52 Gy. One patient died of pneumonia and disseminated intravascular coagulation syndrome 1 month postoperatively. The 1- and 2-year survival rates of the remaining 13 patients were 84.6% and 61.5%, respectively; among the 10 with GB, they were 80% and 50%. Generally, the smaller the tumor size, the better the results. There were no adverse effects, despite the dose 15 to 50 Gy applied temporally to the tumor bed. IOR was especially effective against small, localized tumors, but was not always beneficial in cases of large tumors, particularly those with a contralateral focus. The improved survival rate in this series demonstrates that IOR is significantly effective in the "induction of remission" following surgical excision of malignant gliomas.

Adult↗
PubMed1989

[Evaluation of super-elasticity characteristics of orthodontic Ni-Ti alloy wire].

Mechanical properties of orthodontic Ni-Ti alloy wires, especially their super-elasticity characteristics, were investigated in order to use them effectively in the clinics. In this study, twenty commercial orthodontic Ni-Ti wires were tested and two parameters were devised for the load-deflection curve and introduced to evaluate the practical mechanical properties, one being the "super-elastic index: SEI" for super-elasticity, and the other being the "E-load" for the load in the super-elastic region. There was a "flat area" in the load-deflection curve of the super-elastic type of Ni-Ti alloy wires, whose SEI was above seventy and a continuous force could be used through the wide range of deflection. The load of the work-hardened type of Ni-Ti wires, SEI below thirty, was nearly proportional to the deflection. And the middle type showed intermediate properties of the two. The E-load values of the super-elastic type wires are thought to indicate the load level in the super-elastic region. The quantitative evaluation of the super-elasticity characteristics of the orthodontic Ni-Ti wires became possible by the introduction of these parameters.

Dental Alloys↗
PubMed1989

[Cytotoxicity of pure metals].

The cytotoxic effects of pure metals on L-929 mouse fibroblasts were examined using extracts obtained by dynamic extraction of Cu, Al, Ti, V, Cr, Mo, Mn, Fe, Co and Ni. The order of cytotoxicity expressed in ppm was Cr greater than V greater than Co greater than Fe greater than Mn greater than Cu greater than Ni much greater than Mo. On the other hand, the order in mM was Cr greater than Co greater than V greater than Fe greater than Mn greater than Cu greater than Ni much greater than Mo. Al and Ti showed no cytotoxicity. Thus, the cytotoxicity of pure metals was dependent on their concentration and the chemical state in the extracts.

Aluminum↗
PubMed1989

[Mother to child transmission of human T cell leukemia virus type-1].

Infection of HTLV-1 during childhood may be the most probable cause of leukemogenesis of ATL. The possibility of mother to child transmission of HTLV-1 was studied. Our epidemiological investigation disclosed that almost all mothers of HTLV-1 carrier children were positive for anti-HTLV-1 antibody and children born from carrier mothers showed statistically higher positive rate for anti-HTLV-1 antibody than control groups. A large number of HTLV-1 positive lymphocytes were detected in the milk from carrier mother, but not in the cord blood from newborn babies delivered from carrier mothers. We inoculated the fresh milk collected from carrier mothers into the oral cavity of a common marmoset to prove the oral infection. The marmoset was found to be seroconverted and viral antigen expression was detected in short term cultures of its peripheral T lymphocytes. These results suggest that we can prevent the transmission of HTLV-1 by prohibiting the breast-fed [corrected] by carrier mother. We have so far followed up 55 children born from carrier mothers but fed with compound milk only. None of the children in this group became a carrier of HTLV-1, whereas breast-fed group was found to have higher incidence of sero-positivity for HTLV-1. Therefore the trial prevention of HTLV-1 transmission is now undertaken in Nagasaki district.

Adult↗