Effects of fetal corticosteroid treatments on postnatal surfactant function in preterm lambs

Effects of prenatal corticosteroid on the properties of surfactant have not previously been evaluated. A single ultrasound-guided fetal injection with 0.5 mg/kg betamethasone 48 h before delivery of preterm lambs at 134- to 135-days gestation improved oxygenation, lowered the ventilatory pressures required to maintain arterial PCO2 between 30 and 40 Torr and decreased the protein leak of albumin from the intravascular to the alveolar space. This dose of glucocorticoid did not alter surfactant-saturated phosphatidylcholine pool sizes in the airspaces of preterm lambs. However, the treatment changed the characteristics of the surfactant recovered from the ventilated preterm lambs. The in vitro conversion from heavy to light subtype surfactant decreased from 59% for the saline-treated lambs to 37% for the corticosteroid-treated lambs after 180 min of surface area cycling (P < 0.02). Surfactant from the corticosteroid-treated lambs also increased the dynamic compliance of preterm surfactant-deficient rabbits more than did surfactant from the saline-treated lambs (P < 0.05). Prenatal treatment of preterm lambs with betamethasone improved the functional characteristics of surfactant without significant effects on the alveolar surfactant pool sizes.

Relationships between perceived exertion and physiological variables during swimming

The relationships between perceived exertion and the physiological variables oxygen uptake (VO2), heart rate (HR) and blood lactate concentration (HLa) were studied in tethered swimming. Seven male and ten female subjects swam at five submaximal intensities. The degree of perceived exertion was measured both on the category scale (RPE) and on the category-ratio scale (CR-10). All five dependent variables (VO2, HR, HLa, RPE and CR-10) were described by the equation R = a+c (S-b)n with the drag (D) in tethered swimming as an independent variable. The relationships between D and VO2, HR and RPE were linear with a level of fitness correlation (r = 0.989-0.999) for both males and females. The HLa exponents were 3.2 for males (r = 1.000) and 3.6 for females (r = 0.991), and CR-10 were 1.5 for males (r = 0.998) and 1.9 for females (r = 1.000), respectively. The growth functions for males and females were very similar. The conclusion is that RPE is effective as a measure of exercise intensity and can be used for exercise prescription in practical swimming.

Surfactant treatment and ventilation effects on surfactant SP-A, SP-B, and SP-C mRNA levels in preterm lamb lungs

The effects of exogenous surfactant treatment combined with postnatal ventilation on surfactant protein (SP)-A, SP-B, and SP-C steady-state mRNA levels were evaluated in preterm sheep at 120, 132, and 139 days gestation. Three groups were studied at each gestation period: animals ventilated and treated with 100 mg/kg natural sheep surfactant, animals ventilated and not treated with surfactant, and a comparison group of lambs that were neither ventilated nor treated with surfactant. In unventilated lambs, SP-A and SP-C mRNA levels measured by densitometry from Northern blots increased between 120 and 132 days gestation (P < 0.05). At 120 days gestation, no differences in SP-A, SP-B, or SP-C mRNA levels were noted among the three groups. At 132 days gestation, SP-A mRNA levels increased in both ventilated groups (P < 0.01), but no additional surfactant effect on SP-A mRNA expression was detected. There were no changes in SP-B or SP-C mRNA levels among the groups at 132 days gestation. At 139 days gestation, mRNA levels for both SP-A and SP-B increased after ventilation, compared with the unventilated groups (P < 0.05). Furthermore, an additional effect of surfactant treatment to increase SP-A mRNA levels relative to animals undergoing ventilation alone was noted (P < 0.05). We conclude that postnatal changes in mRNA levels for the surfactant proteins are gestationally regulated and protein specific.

Phase-contrast MRA in the evaluation of EC-IC bypass patency

We have assessed three-dimensional (3-D) phase-contrast (PC) MR angiography (MRA) in the evaluation of extracranial (EC)-intracranial (IC) bypasses. This technique was performed in 22 patients (26 examinations) to evaluate the patency of their EC-IC bypasses (a total of 37 operated sites). Three sets of phase images for antero-posterior, right-left, and supero-inferior flow velocity components were also obtained in eight patients to produce directional flow images. Directional 2-D PC flow imaging was also performed in three other patients. The patency of bypasses was confirmed in 57% and suggested in 24% of operated sites using 3-D PC MRA alone. The diagnostic value of PC MRA proved superior to that of time-of-flight MRA, because the former emphasizes the signal intensity of vessels without interference from stationary tissues and is less affected by progressive saturation of inflowing spins. 2-D or 3-D directional flow images aided in understanding the flow dynamics in 69%. In patients who had been examined pre-operatively changes in intracranial flow of dynamics could be estimated on post-operative PC MRA. Although PC MRA has several limitations, it proved to be a useful imaging modality for following up patients who had undergone EC-IC bypass operations.

Enhancement of Ca(2+)-dependent endonuclease activity in L1210 cells during apoptosis induced by 1-beta-D-arabinofuranosylcytosine: possible involvement of activating factor(s)

Internucleosomal DNA fragmentation and morphological changes in nuclei typical of apoptosis were observed in L1210 cells incubated with 1.0 micrograms/ml of 1-beta-D-arabinofuranosylcytosine (ara-C). To investigate the mechanisms involved, we examined the activities of endogenous endonucleases in nuclei and cytoplasm. Both fractions of control cells contained Ca(2+)-dependent endonuclease which was capable of mediating internucleosomal DNA fragmentation. The assay system using two kinds of target substrates, i.e., nuclear chromatin of CCRF-CEM cells and naked DNA purified from the same cells, revealed that the activity of Ca(2+)-dependent endonuclease was enhanced in the crude nuclear extracts of cells treated with 1.0 microgram/ml of ara-C for 24 h or 48 h. The activity was extracted more easily from ara-C-treated cells than control cells without sonication of the nuclear fraction. On the other hand, in the cytoplasmic fraction of the cells, the activity towards naked DNA was unchanged, whereas that towards nuclear chromatin was clearly enhanced. These results suggest that internucleosomal DNA fragmentation induced by ara-C treatment is associated with enhancement and activation of constitutively expressed Ca(2+)-dependent endonuclease in L1210 cells.

[Neoadjuvant endocrine therapy prior to nerve-sparing radical prostatectomy in patients with stage T2 prostatic cancer]

Radical prostatectomy is the effective treatment for clinical T2 prostatic cancer. However, clinical T2 stage is often understaged preoperatively. The objective of neoadjuvant therapy is to increase the curability of surgery to understaged patients. The present study was based on patients who had had neoadjuvant endocrine therapy (LH-RH agonist) prior to radical nerve-sparing prostatectomy for T2 prostatic cancer. Sexual function were estimated before and after surgery. Ten patients with a mean age of 64.6 years (range 57-71 years) and biopsy-proven cancer received this treatment modality. No patients had evidence of lymph node metastasis by the pelvic computerized tomography and their bone scan was negative for metastasis. Clinical stage was T2a in 3 patients and T2b in 7. The grade of these tumors as assessed on prostatic biopsy before neoadjuvant endocrine treatment was well differentiated in 3 and moderately differentiated in 7. The duration of neoadjuvant endocrine therapy was 3.6 months (range 2-5 months) in average. Serum levels of prostatic specific antigen (PSA) were examined monthly and prostate volume was measured by transrectal ultrasonography before and after neoadjuvant treatment. Decrease in serum PSA values was observed from an average level of 8.6 ng/ml (range 3.1-17.5 ng/ml) determined prior to neoadjuvant treatment to an average of 1.1 ng/ml (range 0.6-3.3 ng/ml) determined after neoadjuvant treatment. An average reduction of prostatic volume was 25.3% (range 7.4-56.7%) after neoadjuvant therapy. Pathological effects of the neoadjuvant therapy by the criteria proposed by Japanese Urological Association were Grade (G) 0a in 3 patients, G0b in 4, G1 in 2 and G2 in 1. Of patients who had 10 stage T2 cancer before treatment, 4 had pT2 and 6 pT3.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical study of renal cell carcinoma with brain metastasis]

Of 130 cases with renal cell carcinoma treated at Cancer Institute Hospital from January, 1981 to December, 1992, 14 (10.6%) developed brain metastasis, 12 of whom had had preceding pulmonary metastasis. Interval between the initial treatment of the primary lesion (nephrectomy in 13, embolization in 1) and the diagnosis of brain metastasis ranged 0 to 57 months with a median of 11 months. Twelve patients had clinical symptoms such as headache, vomiting, paralysis or disturbance of consciousness. Eleven patients were treated with external beam irradiation (30-60 Gy linear accelerator). Only 3 (30%) of 10 patients with measurable lesion on CT scan achieved PR but 6 (66.7%) of 9 had symptomatic improvement. Especially, chronic intracranial hypertension such as headache and vomiting disappeared in 5 (83.3%) of 6. Average survival period and one year survival after the diagnosis of brain metastasis were 5 months and 14.3%. Although most of the patients with brain metastasis died of the progression of other organ metastasis, radiation therapy for brain metastasis was useful to palliate the agonizing symptoms.

Visible light-sensitized oxidation of arachidonic acid in the presence of inperatorin

To understand the mechanism of the phototoxic effects of inperatorin, a psoralen derivative used as a pigmentation agent, we have investigated the photosensitized oxidation of arachidonic acid (ARA) by irradiation with visible light (> 400 nm) in the presence of inperatorin. HPLC and GC/MS analyses of the products showed the formation of many hydroperoxyeicosatetraenoic acids (HPETEs) including the products of lipoxygenase-catalyzed reactions such as 5- and 15-HPETEs, which are the precursors of chemical mediators such as leukotrienes and lipoxins, during the reaction. Active oxygen scavening agents such as D-mannitol, superoxide dismutase, and beta-carotene inhibited the formation of the oxidation products, indicating that the oxidation reaction was mediated by various active oxygen species. These results suggest that the phototoxic effects of inperatorin could also be induced by visible light and could be explained at least partially in terms of inflammation initiated by the biologically active HPETEs arising from photosensitized oxygenation reactions of ARA with the drug.

[Central ocular hypotensive effect of noradrenaline]

We investigated the effects of topical and central administration of noradrenaline (NA) on the intraocular pressure (IOP) in pigmented rabbits. Unilateral instillation of NA (200 micrograms) produced no significant change in IOP. On the other hand, intracerebroventricular (ICV) administration of NA (0.01-1 micrograms) decreased IOP in both eyes in a dose-related fashion. The ocular hypotensive effect of NA was diminished by sympathectomy of the superior cervical sympathetic nerve or by ICV pretreatment with yohimbine hydrochloride 1-10 micrograms). These results suggest that the hypotensive effects of contrally administered NA might be mediated by alpha 2-adrenoceptor stimulation in the central nervous system.

The determination of nitrite and nitrate in human blood plasma by capillary zone electrophoresis

The determination of nitrite and nitrate in human blood plasma by capillary zone electrophoresis (CZE) is described. Electrophoresis was carried out in a 65 cm long, 75 microns wide silica capillary, using 750 mM sodium chloride containing 5% NICE-Pak OFM Anion-BT (an additive reversing the electroosmotic flow) as running buffer, at a potential of 20 kV, with on-column UV detection at 214 nm. Under these conditions, the two anions migrated in the order of nitrite and nitrate, completely resolved from each other. Forty-one samples of ultrafiltered blood plasma of healthy volunteers were analyzed. The concentrations of nitrite and nitrate were 0.15 +/- 0.07 mg/L and 3.2 +/- 1.6 mg/L (mean +/- SD), respectively, with a linear correlation in the range of 0.1-50 mg/L. The within-day and between-day coefficients of variation (CVs) for nitrite and nitrate were lower than 5% and 8%, respectively. The recovery was 97-114%. The estimated plasma volume needed for each determination was 108 nL.

[A survey of utilization of urinary alarm systems in nursing homes]

A questionnaire survey was performed on 63 nursing homes and 1006 care workers in the nursing home, in order to elucidate the actual state of utilization of urinary alarm systems (systems). About 3% of the nursing homes in all of Japan are utilizing the system with 12.5% of all institutionalized elderly having a diaper sensor of those nursing homes with the system, 86% use the system continually. In 51% of the nursing homes, care workers change diapers immediately after sensor alarm is triggered. The reasons for not being able to change the diaper immediately were either care workers had other pressing work, or simultaneous or overlapping sensor alarm calls occurred. The usefulness of the system was recognized for "prevention of decubitus" (66%), "prevention of contact dermatitis from diapers" (82%), "decrease of ammonia smell" (27%), and "discontinuation of diaper" (26%). As for problems associated with the system or factors that increase work load, responses included "sensor does not respond sometimes" (67%), "increased diaper changes" (53%), "increased nurse calls due to urinary urgency" (41%), and "disconnection of the sensor by the patient" (34%). The percentage of care workers who reported an increase in work load was 73%, especially where the ratio of care workers number/institutionalized elderly was low.

[Successful treatment of a 74-year-old man with refractory anemia with excess of blasts in transformation (RAEB in T) by low-dose Ara-C injection]

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoietic disorders characterized by normal or hypercellular but dysfunctional bone marrow. They usually are refractory to empirical therapeutic regimens. Recently the prevalence of MDS in the elderly is increasing and now the syndromes are relatively commonly encountered in elderly patients. Two major causes of death in MDS are progression to acute leukemia (especially in subtypes of RAEB and RAEB in T), and bone marrow aplasia. Since cytoreductive therapy for RAEB or RAEB in T in the elderly is often accompanied by serious adverse complications, such as infection and hemorrhage, special care is necessary. Here we describe successful induction remission in a 74-year-old man with MDS (RAEB in T) by twice daily low-dose cytosine arabinoside injections (10 mg/m2, s.c.), which was well-tolerated, free of serious adverse effects, and seemed to be a useful therapeutic option for elderly patient with RAEB or RAEB in T.

[A case of erythroleukemia associated with lung aspergilloma successfully treated with continuous drip infusion of amphotericin B]

In September 1990, a 55-year-old female with erythroleukemia was treated with enocitabine, mitoxantrone, vincristine, and etoposide. Despite prophylaxis of infectious diseases by oral administration of 2,400 mg/day amphotericin B (AMPH), 600 mg/day ofloxacin, and 1,500 mg/day kanamycin, pneumonia with refractory pyrexia appeared and developed cystic lesions with air crescent signs thereafter. Finally, the cystic one formed fungus balls. The pneumonia was diagnosed as aspergillus pneumonia by fungus growth in the tissue in the transbronchial lung biopsy specimens and by an elevation of serum anti-Aspergillus antibody. The patient had continuously been administered with AMPH for 16 days, increasing the drug doses every 2 days. The maximum plasma level of AMPH rose up to 0.78 micrograms/ml, the total amount up to 166 mg. The fungus balls disappeared completely without adverse effects except a transient decrease of plasma potassium level. Pharmacological studies had been reported that tissue AMPH levels elevated more than twice as much as that of the plasma. Although the maximum plasma level was less than that of MIC for Aspergillus, the lung tissue drug level was suspected to have been maintained higher by continuous drip infusion. These findings indicate that continuous drip infusion of AMPH is one of the useful treatment for lung aspergillosis.

Change in the distribution of alpha-tocopherol stereoisomers in rats after intravenous administration

Synthetic alpha-tocopherol (alpha-Toc) contains equal amounts of eight different stereoisomers arising from three chiral centers in the phytyl tail. Of these, the four stereoisomers with the 2R configuration are generally more active than their corresponding 2S-isomers. We investigated the change in distribution of alpha-Toc stereoisomers in the plasma and tissues after intravenously administering all-rac- and SRR-alpha-Toc acetate. The concentration of 2R-isomers in the rat plasma after administering all-roc-alpha-Toc acetate was higher than that of the 2S-isomers. On the other hand, the concentration of 2R-isomers in the liver was lower than that of 2S-isomers up to 6 h. In the rat plasma after administering only SRR-alpha-Toc acetate, no SRR-alpha-Toc was detected after 6 h, although SRR-alpha-Toc in the liver was retained at a higher level than in the other tissues. We presume that the intravenously administered 2R- and 2S-isomers were easily transported into the liver from the plasma, the 2R-isomers being preferentially released from the liver into the blood, whereas the 2S-isomers remained in the liver for up to 6 h.

[Application of microdialysis for pharmacokinetic study in rabbit anterior chamber]

We evaluated a microdialysis technique for analyzing the pharmacokinetics of instilled or orally administered ofloxacin in the anterior chamber of pigmented rabbits. A microdialysis probe was inserted into the anterior chamber and was perfused (2 microliters/min) with Ringer solution using a microinjection pump. Two hours later, 20 microliters of 0.15 and 0.3% ofloxacin was instilled into an eye, or 20 mg/kg of the drug was administered into the stomach through an intubated catheter. Dialysate was then collected every 15 or 20 min for 6 (instillation) or 8 (oral administration) hours. Ofloxacin concentration in dialysates was determined with a HPLC-spectrofluorometry system. Ofloxacin levels in dialysates increased after the instillation in a dose-related manner, reached a maximum at 30 and 45 min, and then decreased gradually with t1/2 of 136 and 114 min after the 0.15% and 0.3% instillation, respectively. After oral administration, ofloxacin levels in dialysates reached a maximum at 120 min and decreased with t1/2 of 175 min. These data suggest the usefulness of microdialysis for pharmacokinetic studies in the anterior chamber, since continuous and stable data can be obtained from each animal.

Diagnosis of chronic liver disease from liver scintiscans by fuzzy reasoning

We investigated the possibility that fuzzy reasoning might be used to standardize diagnosis of liver disease based on scintigraphic results and compared the results with those obtained when scintiscans were scored conventionally.

METHODS

Seventy-five patients with chronic liver disease (11 patients had chronic persistent hepatitis, 26 had chronic aggressive hepatitis and 38 had cirrhosis) and 25 controls were studied. Another 75 patients with hepatitis or cirrhosis were examined to test the effectiveness of the membership functions. Liver scintiscans were taken 20 min after the intravenous injection of 111 MBq of 99mTc-phytate. Fuzzy reasoning was used to evaluate the following five items: the ratio of the sizes of the left and right lobes, splenomegaly, radioactivity in the bone marrow, deformity of the liver and distribution of radioactivity in the liver. The degree of conformity to each of the three liver diseases being investigated was substituted into the membership function for the conclusion. The center of gravity for each patient's results was calculated. Conventional scoring was made with three levels for each of the five items examined by fuzzy reasoning.

RESULTS

Distinctions between chronic persistent hepatitis and chronic aggressive hepatitis were difficult to assess with fuzzy reasoning and conventional scoring. The diagnostic accuracy was 95% for patients with cirrhosis and 88% for patients with chronic hepatitis with fuzzy reasoning. With conventional scoring the accuracy was 86% for patients with cirrhosis and 75% for patients with chronic hepatitis. When fuzzy reasoning was used to examine the other 75 patients with chronic liver diseases, the accuracy was 93% for patients with cirrhosis and 86% for patients with chronic hepatitis.

CONCLUSION

The method is simple and can be used routinely in clinical settings.

Experimental assessment of newly devised transcatheter stent-graft for aortic dissection

Despite recent advances, surgical results for Stanford type B dissection are not yet satisfactory because the procedure is so highly invasive. The aim of this study was to devise a new intraaortic (IA) graft that would offer less invasive treatment for type B dissection. To close the entry of type B dissections using transcatheter placement, we devised an IA graft (inner diameter, 15-20 mm; length, 40 to 60 mm) in which a self-expandable stent was covered with a thin, open-cell-structured polyurethane jacket. In acute animal experiments in which type B aortic dissections were prepared in 4 mongrel dogs, IA grafts were implanted to close the entry using a transfemoral catheter sheath, and closure of all the entries was confirmed by aortography. In chronic experiments, five IA grafts for normal descending aortas and one IA graft for an experimentally dissected aorta were implanted to observe histologic biocompatibility for up to 8 months. Histopathologic examination conducted at the projected sacrifice periods revealed that endothelialization of the luminal surface of the IA graft had begun as early as 1 month after implantation and was completed within 4 months. The prototype device that we developed may be promising as an effective, minimally invasive therapeutic intervention for closure of the entry site of type B dissection.

Clearance of surfactant protein B from rabbit lungs

To characterize the metabolism of surfactant protein B (SP-B) in vivo, we measured the clearance of SP-B from adult rabbit lungs. Purified rabbit SP-B was radiolabeled with 125I by the Bolton-Hunter method. Trace amounts of 125I-labeled SP-B mixed with [14C]dipalmitoylphosphatidylcholine (DPPC) were given intratracheally via a bronchoscope to rabbits 0-16 h before collection of alveolar washes (AW). Macrophages were recovered from AW, and lamellar bodies (LB) were isolated from lung tissue by differential centrifugation. 125I-SP-B was cleared more rapidly from the airspaces and the total lung (half-life 7 h) than was DPPC (half-life 11 h in the total lung). There was an approximately threefold accumulation of SP-B relative to saturated phosphatidylcholine in macrophages at all times. The proportion of 125I and 14C radioactivities in lamellar bodies was similar at 2 and 4 h, but there was 14-fold less 125I-SP-B than [14C]DPPC in lamellar bodies by 16 h. This loss of SP-B from the lamellar body fraction is consistent with less recycling of SP-B. The results demonstrate different clearance kinetics of these two components of surfactant and indicate a significant role of macrophages in the clearance of SP-B.

Suppression of pulmonary metastasis by angiogenesis inhibitor TNP-470 in murine osteosarcoma

We treated a murine osteosarcoma cell line, LM8, which preferentially metastasizes to the lungs, with a new angiogenesis inhibitor, TNP-470, to evaluate the efficacy of this compound in the suppression of pulmonary metastasis of osteosarcoma. In an in vivo experiment, tumor cells were inoculated i.v. into C3H mice, and TNP-470 or vehicle alone (control group) was administered s.c. every day for 3 weeks. In the TNP-470-treated groups, both the number of pulmonary metastatic nodules and the lung wet weight were significantly reduced in a dose-dependent manner. Similarly, vascular density in the metastatic tumors estimated by immunohistochemical staining with anti-von-Willebrand factor antibody as an endothelial marker were significantly reduced. No severe side-effects were found. In an in vitro experiment, viable tumor cells were counted after 3 days' treatment with TNP-470. The 50% inhibitory concentration was 0.6 ng/ml for LM8, which was more sensitive than other tumor cells previously reported. Our results show that TNP-470 suppresses the pulmonary metastasis of LM8 and suggest that both its anti-angiogenic activity and cytostatic activity towards LM8 are responsible for the antitumor effect.