[Clinical experiences and postoperative results with partially implantable middle ear implant]

A partially implantable middle ear implant using an ossicular vibrator of a piezoelectric ceramic bimorph has recently been developed in Japan as a new rehabilitative method for hearing. Four patients at the Miyazaki Medical College Hospital were implanted with this device between September 1994 and October 1996. Implantation of the internal component was performed under local anesthesia after confirmation of sufficient sensitivity to the ossicular vibrator in an intraoperative vibratory hearing test. All patients regained socially useful hearing with the middle ear implant without any foreign body reactions or recurrence of otitis media. None of the cases showed any elevations of bone conduction thresholds 2 to 4 years postoperatively. Natural and clear sounds without interference noise and howling due to acoustic feedback were highly satisfactory in all patients. However, the first case, who had an implant in an ear following cholesteatoma surgery using the intact canal wall technique, experienced about a 10dB deterioration of the average hearing level with the implant 2 years after implantation. Gradual deterioration appeared to be caused by the retracted tympanic membrane interfering with the mobility of the ossicular vibrator. The following three cases were implanted in ears previously operated on by radical mastoidectomy, showing stable or improving hearing results with the implant. Closure of the external canal skin at the cartilaginous portion at the time of implantation seemed appropriate to maintain a sufficient middle ear space for the ossicular vibrator to work properly. Our case study confirms that the partially implantable middle ear implant is a safe and useful tool for patients with mixed deafness which cannot be satisfactorily rehabilitated by tympanoplasty and/or a conventional hearing aid.

Retention, excretion and translocation of 239Pu in rats following inhalation of 239PuO2 calcined at 1150 and 400 degrees C

Wistar rats inhaled 239PuO2 particles prepared by the calcination of 239Pu hydroxide at 1150 and 400 degrees C. Lung retention, fecal and urinary excretion, and translocation of 239Pu were compared between the two calcination temperatures. The clearance of 239Pu from the lungs was significantly faster in the rats exposed to 239PuO2 calcined at 400 degrees C (low-temperature group) than those exposed to 239PuO2 calcined at 1150 degrees C (high-temperature group). Both the fecal excretion of 239Pu and the ratio of fecal excretion to urinary excretion was greater in the low-temperature group than in high-temperature group. The amounts of 239Pu translocated from the lungs to the other organs were very small. Even in the liver, which accumulated the largest amount of 239Pu except for the lungs, only 0.13-0.20% of the initial lung burden was retained 1 year after inhalation. The amount of 239Pu deposited in the liver was greater in the high-temperature group than in the low-temperature group both at 1 month and 1 year after the inhalation. These findings clearly suggest that the lung retention of 239Pu in rats is significantly affected by the calcination temperature of 239PuO2.

Successful bone marrow transplantation in a child with X-linked hyper-IgM syndrome

We report a case of an 11-year-old boy who underwent successful bone marrow transplantation for X-linked hyper-IgM syndrome (XHIM). The donor was an HLA-matched brother. The patient was conditioned with busulfan, cyclophosphamide and anti-thymocyte globulin. He received 4.7 x 10(8) marrow cells per kg from the donor. Prophylaxis against graft-versus-host disease consisted of cyclosporine and short-term methotrexate. The clinical course after the bone marrow transplantation was uneventful, and 12 months after transplantation the patient was doing well with no need for therapy. We examined expression of the CD40 ligand (CD40L) on the patient's activated T lymphocytes and in vitro production of immunoglobulins by his lymphocytes. Although expression of CD40L was totally absent before the bone marrow transplant, subnormal expression appeared after the transplantation. In vitro production of IgG and IgA also was improved by the transplant. Based on our experience bone marrow transplantation appears to be a reasonable therapeutic option for patients with XHIM if HLA-matched family donors are available.

[Clinical trial of antithymocyte globulin for prophylaxis of acute graft-versus-host disease in pediatric recipients of bone marrow transplantation from unrelated donors]

We studied the effectiveness of antithymocyte globulin (ATG) in preventing acute graft-versus-host disease (a-GVHD) in children who received bone marrow transplants from unrelated HLA-matched donors at one institution. Of 39 patients who received transplants between 1993 and 1997, 23 were given ATG on the basis of informed consent. Either Thymoglobulin (Pasteur Merieux, 2.5 mg/kg/day) or Lymphoglobulin (15 mg/kg/day) was administered for 4 days. a-GVHD (> or = grade II) developed in 33% of the ATG group (n = 21) and in 44% of the non-ATG group (n = 16). Although a-GVHD (> or = grade II) appeared less frequent in the ATG group, the difference was not statistically significant. Among the subjects with hematological malignancies, no significant difference was observed in frequency of a-GVHD (> or = grade II) or 3-year survival rate for the ATG group (n = 10) and non-ATG group (n = 16). However, the incidence of cytomegalovirus infection was much higher (p < 0.01) in the ATG group (70%) than in the non-ATG group (19%). From this study, we were not able to confirm the benefits of ATG as described by other investigators.

Differential dose responses of pulmonary tumor types in the rat after inhalation of plutonium dioxide aerosols

Dose responses were compared among primary lung tumors and their histological types induced by a single inhalation exposure of female Wistar strain rats to submicron-size and polydispersed aerosols of plutonium dioxide (239PuO2). While the primary lung tumors were found only in 2.3% of the unexposed control animals, the frequency of all the primary lung tumors in the exposed animals was 44% at the mean lung dose of 0.71 Gy, and increased sharply at the doses of 1.5 Gy or more, reaching the maximum of 97% at 5.4 Gy, and the dose responses around at 1.0 Gy were different between benign and malignant lung tumors. Almost all the pulmonary tumors in the exposed animals were classified into epithelial types such as adenomas, adenocarcinomas, adenosquamous carcinomas, and squamous cell carcinomas. The dose responses were different between these tumor types as shown by the peak incidence of adenomas at 0.71 Gy, adenocarcinomas at 2.9 Gy, adenosquamous and squamous cell carcinomas at 5.4-8.5 Gy, respectively. As the magnitudes of neoplastic lesions in pulmonary carcinomas were expressed by histological scores, metaplasias and adenomatous lesions most frequently appeared at doses of 1.5 Gy, while the appearance and increase of carcinomatous lesions differed in the dose ranges as shown by the peak incidence of adenocarcinomatous lesions at 2.9 Gy, and adenosquamous or squamous lesions at 5.4-6.6 Gy. These results indicate a differential dose response of pulmonary carcinogenesis in which metaplasias and benign adenomas were induced at lower doses (< 1.0 Gy), whereas malignant carcinomas were induced at relatively higher doses (> 1.5 Gy). Together with the increase of carcinomatous lesions at higher doses, the intranuclear p53 protein accumulation was detectable, but only in a few percentages of malignant carcinomas.

Allogeneic bone marrow and peripheral stem cell transplantation from a haplo-identical mother and CD34 positive selection for CML

A 6-year-old boy with CML in blastic crisis was transplanted with BM and PBSC from his HLA-mismatched MLC-positive mother following CD34-positive selection. Preconditioning for transplant was with thiotepa, cyclophosphamide, rabbit anti-human thymocyte globulin, and TBI followed by infusion of 2.6 x 10(6)/kg of CD34-positive BM and PBSC. Engraftment was confirmed by FISH analysis, and GVHD was not observed. On day 50, he relapsed and died despite three transfusions of donor lymphocytes without GVHD prophylaxis. CD34-positive cell selection for HLA-mismatched transplantation may prevent severe acute GVHD.

High incidence of malignant lung carcinomas in rats after inhalation of 239PuO2 aerosol

Female Wistar strain rats were exposed to a single inhalation of a submicron-size aerosol of high-fired 239PuO2 to investigate pulmonary carcinogenesis during lifespan periods. The absorbed lung doses of the exposed animals ranged from 0.6 to 12 Gy and were well correlated with the initial lung deposition (ILD) of 0.1 to 2.3 kBq. Survival and induction of primary lung tumors in 116 exposed rats were compared with those in 56 untreated control rats in respect to lung doses received. Mean survival time was greatly reduced, and the cumulative incidence of total lung tumors was markedly increased to 90-100% in rats that received more than 4 Gy, whereas of the controls only one animal (1.8%) died of primary lung tumors. Primary but benign adenomas were present in exposed animals given 1.0 Gy or less, and the incidence of adenomas was 22-25% at 4-5 Gy, but decreased sharply to 3-5% at 6-8 Gy. In contrast, no malignant carcinomas, including adenocarcinomas, adenosquamous carcinomas and squamous cell carcinomas, developed at a dose of less than 1.0 Gy, whereas they were present in 75% or more of the rats given 4-10 Gy, but only in 55% at 12 Gy. Although there were no clear differences in the dose and time required for induction among the carcinoma types, all tended to develop in earlier periods after inhalation than adenomas. Despite the limited number of exposed animals that received lower doses, results suggest that malignant lung carcinomas are highly and early induced and have a different dose-effect relationship than benign adenomas at doses of more than 1 Gy after inhalation exposure to 239PuO2.

[Serum pyridoxal concentration in children during theophylline therapy for bronchial asthma]

This study was designed to investigate the effect of sustained-release theophylline therapy on serum pyridoxal concentration in children with bronchial asthma. Forty-two children with bronchial asthma were divided into two groups according to duration of theophylline administration: The 22 children in group A had been treated with theophylline for less than 4 weeks, whereas the 20 children in group B had been treated for more than 5 weeks. The results obtained from this study were as follows: 1) The serum pyridoxal concentration in group B was significantly lower than that those in group A (p < 0.01). 2) The serum pyridoxal concentration was not significantly correlated with the serum theophylline concentration. These findings suggest that long-term theophylline therapy can depress vitamin B6 status in children with bronchial asthma. Theophylline-induced seizure may be caused by the possible decreased in gamma-aminobutyric acid concentration in the brain as a result of decrease in gamma-aminobutyric acid concentration in the brain as a result of decrease in vitamin B6 status, even if the serum theophylline concentrations are within the therapeutic range.

[Fetal heart rate monitoring during maternal swimming]

Fetal physiology during swimming in pregnancy has remained unclear. To assess the fetal status, the fetal heart rate (FHR) was measured during maternal swimming. We studied individually a group of seventeen women in normal pregnancy (during their third trimester, 35-38th week) who participated in a maternal swimming class. We adapted the Doppler ultra-sound transducer for underwater use and attached it to the mothers' abdomen. FHR was recorded before, during and after swimming. The group swam from 375 to 750 meters in 33 to 41 minutes. During swimming, motion artifacts interfered with the FHR signal and we were only able to detect FHR in eleven in the group. The mean FHR rose significantly during swimming in eight of eleven women compared to the FHR recorded before the exercise. The FHR pattern was reactive and baseline variability was preserved in all cases. No pathological deceleration was seen. It is concluded that maternal swimming under such class conditions is safe for the fetus.

[Basic study on criteria for the reactivity of non-stress tests by means of computer simulation]

The non-stress test has become one of the most popular tests for antenatal surveillance in modern obstetrics. However, the fact that there are so many criteria for 'reactivity' in this test has made it rather difficult to interpret the results of these tests and compare them with each other. Using computer simulation of the occurrence of acceleration in fetal heart beats, the sensitivity and specificity of eight criteria which are in general use were studied. Diagnosis by Brown's criteria produced the best results for both sensitivity and specificity, but the long time necessary for this test is a drawback. However, the predictive value positive (probability of poor fetal outcome with nonreactivity) is only 62% even according to Brown's criteria when the test is done for antenatal care screening of an unrestricted population. The results of the test are far more convincing when it is reactive because the predictive value negative is more than 96%, even when strictly interpreted.

Non-invasive continuous fetal transcutaneous pO2 and pCO2 monitoring during labor

Continuous measurements of fetal scalp transcutaneous pO2 (tcpO2) and pCO2 (tcpCO2) monitoring were performed for 49 patients for the purpose of the evaluation of the fetal well-being. The equipment used was transcutaneous pO2/pCO2 monitor Micro Gas 7640 (KONTRON, Switzerland), which was inserted through the vagina and attached to the fetal head with a suction ring. Blood was taken from the umbilical vessels and pO2 and pCO2 values were analyzed. The correlation coefficient between pO2 in the umbilical artery and tcpO2 was 0.78 (p less than 0.01), and that between pCO2 in the umbilical artery and tcPCO2 was 0.79 (p less than 0.01). Relationships between the transcutaneous blood gas analysis and FHR patterns were discussed. Increase of pCO2 and decrease of tcpO2 was observed in the cases of variable deceleration, not observed in the case of early deceleration. FHR patterns don't always indicate fetal condition, for example in the case of fetal arrhythmia, especially fetal bradycardia. But tcpO2 monitoring of the fetus affected fetal arrhythmia during labor aids diagnosis of fetal distress by FHR patterns, especially in the case of fetuses affected by fetal bradycardia.

Fetal heart variability indices and the accuracy of variability measurements

Several indices of fetal heart rate variability, including short-term variability (STV) and long-term variability (LTV) were analyzed. All the STV indices studied were found to be almost identical statistically. The LTV indices of de Haan et al were the same in essence, while other LTV indices reflected only the fluctuation around the mean fetal heart rate. Analysis using a signal generator indicates that the value of the standard deviation of beat-to-beat difference (one STV index) of less than 7 msec, through the cardiotocomonitor is unreliable; if the standard deviation of beat-to-beat difference is to be measured with an accuracy of 1 msec, an accuracy of measurement of 0.11 msec is necessary even if the fetal heart beat data are sampled with a sampling interval of 1 msec.

[Management of the goat fetus in water using membrane oxygenator by V-A bypass through the cervical vessels--comparison with the A-V bypass method through umbilical vessels]

Fourteen goat fetuses were totally sustained in water by extracorporeal perfusion using a membrane oxygenator. The two groups which underwent perfusion methods may be described as follows: One was an A-V bypass through umbilical vessels which has been reported previously, and the other was a new method, a V-A bypass through cervical vessels. Ten fetuses were perfused by an A-V bypass and the longest survival time was 9 hours. Three fetuses suddenly died shortly after perfusion was started. Four fetuses were perfused by a V-A bypass and the longest survival time was 27 hours. Cardiovascular dynamics were stable from the beginning of perfusion. Autopsy revealed hepatomegaly and bloody ascites in A-V bypassed fetuses but not in the fetuses perfused by a V-A bypass. The A-V bypass through umbilical vessels resembles physiological fetal circulation, and the cannulation technique is not difficult but it needs strict control, especially in the early stages of perfusion. A V-A bypass through cervical vessels doesn't seem to be close to a physiological perfusion for fetuses and the cannulation technique is difficult. But the cardiovascular dynamics are stable, so they are employed for clinical uses in neonatal ECMO. The V-A bypass method seems to be an adequate technique for managing extremely premature fetuses in water.

[Fetal blood sampling by liver puncture]

Fetal blood sampling has been performed in several ways; placentacentesis, fetoscopy, or umbilical code puncture. The problems with these methods are technical difficulties and contamination of maternal blood or amniotic fluid. To solve these problems, we have tried fetal blood sampling by fetal liver puncture with a 21 approximately 23 gauge needle through the maternal abdomen under real time scan guidance. 10 patients underwent this procedure. They ranged from 18 weeks to 22 weeks of gestation at the time of sampling. The sampling procedures were done easily and the samples taken were shown to be pure fetal blood by red blood cell sizing. All the patients continued pregnancy after the examination and none of the pregnancies was influenced by the puncture. 7 patients have been delivered with neither sampling scars nor damage to liver function. This method provides pure fetal blood, the procedure is simple and, in our experience, no complications have occurred.

[Intra-arterial infusion of oncostatics in recurrent cervical carcinoma]

Five cases of recurrent cervical carcinoma with restricted recurrent site in the pelvis were treated with intra-arterial infusion of oncostatics via the internal iliac artery. The tip of the catheter was put in the internal iliac artery, just proximal to the superior glutea artery, through the a. glutea inferior or superior with ligation of both the a. glutea superior and inferior so as to get a high concentration of drugs at the lesion. Several chemotherapeutic agents, such as Cisplatin, adriamycin, pepleomycin, mitomycin C and 5-FU, were infused through the other end of the catheter, which was fixed at the subclavian fossa of the anterior chest. The clinical efficacies according to Karnofsky's criteria were 0-C in one case, 1-A in 1 case and 1-B in 3 cases. The overall response rate above 1-B was 60%. Two cases were dead, one due to inflammation in the pelvic dead space and D.I.C. and other due to myocarditis and heart failure. The other three were alive and treated with weekly intra-arterial infusion at our outpatient clinic. No troubles, such as spontaneous removal of the catheter, inflammation around the catheter or bleeding, have been encountered. The toxicities in the case of intra-arterial infusion were less prominent than in the case of intravenous administration of the same dosage of the oncostatics.

[Comparison of variability (STV and LTV) indices by computer-simulated data]

Many investigators have proposed their own formula for quantitative evaluation of STV (short term variability) and LTV (long term variability). There has even been confusion over the definition itself of STV. We compared those indices by using 'beat to beat interval' computer-simulated series and found that there is little difference between the STV indices. According to the definition of STV by the Japan Society of Obstetrics and Gynecology, it is the variance in beat to beat difference, which is determined by the variance in beat to beat intervals and the autocorrelation function of the same intervals. For all the 2,500 combinations of the variability and the autocorrelation, normal random interval series were generated by the computer and five indices (Dalton, Cabal, Yeh, Heilbron and de-Haan) were compared with calculated index values using these interval series. Assigning the variability and the autocorrelation to the X-axis and the Y-axis respectively, the Z-axis was used to indicate the value of the STV. Five curved surfaces thus formed have a similar shape, which shows us that these STV indices behave the same way in accordance with the change in STV. Further, the study of LTV indices with the same simulated data showed that Yeh's LTV index indicates only the variability but has no relation-ship with the autocorrelation and both de-Haan and Heilbron's LTV indices represent the variability and the autocorrelation. However, they increase as the autocorrelation increases unlike the STV indices.

Whole-body retention and tissue distribution of 60Co in rats after oral administration of freshwater fish contaminated with 60Co

The purpose of this report is to compare the whole-body retention and tissue distribution in rats of 60Co administered by gavage as inorganic 60CoCl2 or in a form incorporated into freshwater fish. Orizias latipes were placed in vessels containing 21. of tap water with radioactive cobalt. Periodically thereafter the fish were sacrificed, homogenized, and administered to rats via a stomach tube. Control groups of rats were given the radionuclide alone or together with a homogenate of nonradioactive fish. The whole-body retention and tissue distribution of the radionuclide were determined with an Armac counter. The results revealed that rats gavaged with 60Co incorporated into the fish retained much more 60Co than control rats. This trend was notable in rats given fish kept in radioactive solution for longer periods. Marked differences in tissue distribution of 60Co were also observed between rats given 60Co incorporated into fish and control rats.