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Biomedical subjects

M Ikegami

Publications and source records attributed to M Ikegami.

At least 289 records · Page 16Linked to original sources

Effect of maternal hormone treatment on lung protein leakage and lung function of preterm newborn rabbits.

We tested whether maternal administration of corticosteroids, thyrotropin-releasing hormone (TRH), triiodothyronine (T3) or their combinations, would improve lung function of ventilated preterm newborn rabbits. Maternal corticosteroids and T3 treatments did not improve lung compliance; TRH did. The major effect observed was a large improvement in lung compliance following maternal treatment with corticosteroids plus TRH in animals treated with surfactant. These agents made the lung "receptive" to the surfactant treatment. T3 did not improve lung function and no augmented response to surfactant was seen. None of the treated groups had surfactant pool sizes significantly different from controls. The mechanisms of action of corticosteroids and/or TRH seemed to be independent of changes in surfactant pool sizes.

Adrenal Cortex Hormones↗

[A four-year follow-up study of hepatocellular carcinoma with bone metastasis].

A 68-year-old male was admitted to hospital for treatment of a hepatocellular carcinoma with a bone metastasis. By TAE and the administration of PSK, the tumor was necrotized and the AFP level returned to normal range. We presume that this combination therapy of TAE and PSK was able to maintain normal cellular immunity and bring about this good result.

Adjuvants, Immunologic↗

Renal adenoma. Clinicopathological and histochemical studies.

We report the results of clinicopathological and histochemical studies on 64 renal adenomas found in 22 patients. We selected typical renal adenomas for these studies, discarding borderline lesions. The ages of the patients ranged from 42 to 84 years, with an average of 61 years. Male to female sex ratio was 6.3:1. The background conditions included renal cell carcinoma, long-term dialysis, chronic glomerulonephritis, pyelonephritis, hydronephrosis and polycystic kidney. The sizes of the tumors ranged from 0.1 to 2.3 mm in maximum diameter, with an average of 0.9 mm. All the tumors were located in the cortex, especially in the superficial one-third. The cytoplasm of the tumor cells was predominantly eosinophilic, and the tumor structure was predominantly papillary. Histochemical study of 19 adenomas from 13 patients demonstrated that all of the adenomas from 13 patients demonstrated that all of the adenomas were positive for EMA, and for at least one marker of the distal tubulus, i.e., DBA, PNA, SBA and PKK1, and that 9 adenomas were positive for at least one marker of the proximal tubulus, i.e., LM1 and LTA. Renal adenomas had predominant histochemical features of the distal tubulus, suggesting differentiation to a distal tubulus-like histology.

Adenoma↗

[Renal cell carcinoma with a long-term hemodialysis patient: a case report].

A 59-year-old man was found to have a renal cell carcinoma during about one hundred months of hemodialysis by means of an ultrasound tomography. Nephrectomy was done and renal cell carcinoma, clear cell type, with acquired renal cysts were observed, histologically. The usefulness and routine application of ultrasound tomogram are stressed for examination of the renal appearance during the management of hemodialysis.

Carcinoma, Renal Cell↗

In vivo clearance of natural and modified surfactant.

The loss of radiolabelled phosphatidylcholine associated with surfactants and lipid extracts of surfactants from different species sources was measured following tracheal injection into the lungs of adult and 3 day old rabbits. Clearance was more rapid from the lungs of adult than 3 day old rabbits. The percent labelled phosphatidylcholine cleared per 24 h did not change independently of dose injected indicating that clearance and catabolic pathways were not saturable in either group of rabbits. Different species sources or lipid extraction of natural surfactants did not alter clearance rates very much in the 3 day old rabbits. Small differences in clearance rates were identified by comparing rabbit surfactant with calf surfactant or Surfactant-TA in the adult rabbits. These results indicate that the lungs of developing and adult rabbits can clear large doses of surfactants from multiple sources at rates comparable to the species common natural surfactant.

Animals↗

[Studies of urinary proteins, FDP (fibrinogen degradation products), and NAG (N-acetyl-beta-D-glucosaminidase) in renal transplanted patients].

The urinary proteins, FDP (fibrinogen degradation products), and NAG (N-acetyl-beta-D-glucosaminidase) in renal transplanted patients were studied. SDS (sodium dodecyl sulphate) electrophoresis was used for the differentiation of urinary proteins according to their molecular size. In the azathioprine-treated patients with stable renal function, most of the urinary proteins were albumin. However, the low molecular weight (LMW) proteins, which were suggestive of tubular proteins, appeared in the urine of the ciclosporin-treated patients with stable renal function. During the rejection episodes of the ciclosporin-treated patients, the fraction of LMW proteins increased. The elevation of urinary FDP and NAG index (urinary NAG/urinary Cr) were detected in association with rejection episodes. Urinary NAG index increased in proportion to the elevation of serum Cr. However, the elevation of urinary NAG index was found in some ciclosporin-treated patients with normal serum Cr. The elevation of NAG index without the elevation of urinary FDP occurred in ciclosporin nephrotoxicity. The SDS electrophoresis of urinary proteins, urinary FDP, and urinary NAG index can be useful parameters for monitoring ciclosporin nephrotoxicity.

Acetylglucosaminidase↗

Lysophosphatidylcholine uptake and metabolism in the adult rabbit lung.

Tracer quantities of 3H-labeled lysoPC and 32P-labeled natural rabbit surfactant were given intratracheally via a bronchoscope and [14C]palmitate was given intravenously to 25 rabbits with labeled PC and lysoPC measured in the alveolar wash, lung homogenate, lamellar bodies and microsomes at five times from 10 min to 6 h after tracheal injection. Surprisingly, only 31% of the administered lysoPC remained in its original form in the total lungs (alveolar wash + lung homogenate) by 10 min, of which 77% was in the alveolar wash. Meanwhile, by 10 min an additional 37% was already converted to PC, of which more than 98% was in the lung homogenate. LysoPC continued to be rapidly and efficiently converted to PC, with 62% conversion measured at 3 h. The converted lysoPC initially appeared with high specific activity in microsomes, then in lamellar bodies, and finally in the alveolar wash. The intravascular palmitate labeled lung PC had similar specific activity-time profiles in the subcellular fractions, while intratracheally administered natural rabbit surfactant had a constantly low specific activity in microsomes and much higher specific activities in lamellar bodies and alveolar wash. Another 25 rabbits received intratracheal lysoPC labeled in both the choline and palmitate moieties and then were studied from 1 to 24 h after tracheal injection. The ratio of the palmitate to choline labels indicated uptake and conversion to PC primarily by direct acylation rather than transacylation and by intact reuptake and conversion rather than breakdown and resynthesis. LysoPC is an attractive 'metabolic probe' of surfactant metabolism which undergoes very rapid and efficient intracellular conversion to PC via a subcellular pathway that parallels the remodeling and de novo synthetic pathways.

Animals↗

Potential gene products of bean golden mosaic virus have higher sequence homologies to those of tomato golden mosaic virus than to those of cassava latent virus.

Comparison of the nucleotide sequences of the DNAs of bean golden mosaic virus (BGMV), tomato golden mosaic virus (TGMV) and cassava latent virus (CLV) revealed a fairly close relationship between BGMV DNA1, TGMV DNA1, and CLV DNA1 and a comparatively distant relationship between BGMV DNA2, TGMV DNA2, and CLV DNA2. The 200-base region common to the two DNAs of each virus had little sequence homology, except for a highly conserved 33-36 base sequence potentially capable of forming a stable hairpin structure. All the potential coding regions in the BGMV DNAs had counterparts in the TGMV and CLV DNAs suggesting an overall similarity in genome organization but two potential coding regions in the BGMV DNAs had no counterparts in the TGMV DNAs. The most highly conserved ORFs, BGMV 1R1, TGMV 1R1, and CLV 1R1, are the putative genes for the coat proteins of BGMV, TGMV, and CLV. BGMV 1R1 has 91.9% and 71.6% homology with respect to TGMV and CLV. The ORFs (BGMV 1L1; CLV 1L1; TGMV 1L1) and the two smaller overlapping ORFs (BGMV 1L2, 1L3; TGMV 1L2, 1L3; CLV 1L5, 1L3) are conserved in the three viruses. BGMV 2R1 and BGMV 2L1 have higher homology with respect to TGMV but not with respect to 2R1 and 2L1 in CLV. From this study we conclude that BGMV is more closely related to TGMV than CLV.

Amino Acid Sequence↗

Mass screening for hyperprolactinemia and prolactinoma in men.

To determine the incidence of hyperprolactinemia and prolactinoma without symptoms in men, the serum levels of prolactin were measured in 4803 men. Of these, 14 had hyperprolactinemia with prolactin level of over 50 ng/ml, and 3 had prolactin levels of more than 500 ng/ml. Of these 3 subjects, 2 were found to have pituitary prolactinoma by computed tomograph scanning and surgery, the other subject, who was highly suspected to have prolactinoma, refused further examinations. The serum prolactin levels of 51-100 ng/ml in 11 subjects may have been induced by drugs (sulpiride) or unknown factors. The present survey suggests that the incidence of prolactinoma in men in the general population might be estimated to be 1:1600, and that mass screening is useful for early diagnosis of asymptomatic prolactinoma.

Adult↗

Clearance of surfactant phosphatidylcholine from adult rabbit lungs.

Rabbits were given various doses of rabbit surfactant and treatment doses of approximately 100 mg/kg body wt of calf surfactant and Surfactant TA by tracheal injection. The linear loss of radiolabeled phosphatidylcholine from the total lung (alveolar wash and lung tissue) was 3.1, 1.5, and 1.8%/h for rabbit surfactant, calf surfactant, and Surfactant TA, respectively. After 24 h only 6% rabbit, 19% calf, and 9.7% Surfactant TA phosphatidylcholine were recovered by alveolar wash, and alveolar macrophage fractions contained less than 1% of the injected labeled phosphatidylcholine. The loss of rabbit surfactant phosphatidylcholine 24 h after tracheal injection did not change for doses in the range of 0.5-70 mumol phosphatidylcholine per kilogram, indicating nonsaturable clearance pathways. Very little of the labeled rabbit surfactant phosphatidylcholine lost from the lungs could be recovered in other organs, and 90% of the recovered labeled phosphatidylcholine in the liver was unsaturated, implying de novo synthesis using precursors from degraded phosphatidylcholine. The surfactant did not change endogenous lung phosphatidylcholine synthesis or its secretion to the alveolus. There were no adverse effects of the surfactant treatments noted in healthy rabbits.

Animals↗

Corticosteroid potentiation of surfactant dose response in preterm rabbits.

Fetal rabbits were treated with corticosteroids by maternal administration for 48 h before delivery at 27 days gestational age. Both corticosteroid-treated and control animals then received exogenous natural rabbit surfactant at birth at doses of 0-75 mg lipid/kg. After 10 min of ventilation at tidal volumes of 12-15 ml/kg, static pressure-volume measurements were made. At all surfactant doses there was a significantly higher maximal lung volume, higher dynamic compliance, and lower pressure requirement in the corticosteroid-treated than in the control rabbits (P less than 0.01). Control animals showed incremental improvements in dynamic compliances and maximal lung volumes up to a dose of 50 mg/kg, whereas corticosteroid treated animals improved to a maximum at the low dose of 15 mg/kg (P less than 0.01). However, surface tension as assessed by lung stability index improved with increasing surfactant dose but was not significantly different between corticosteroid-treated and control animals at a given dose. The results imply that maternal corticosteroid treatment potentiates surfactant replacement by a change in lung structure that is independent of surface tension effects.

Animals↗

Pulmonary effects of acute prenatal asphyxia in ventilated premature lambs.

The effect of profound repetitive prenatal asphyxial insults on the cardiopulmonary function of premature ventilated lambs was studied. Twenty-nine fetal lambs (approximately 138 days gestational age) were exteriorized. In 16 of these lambs, the umbilical cord was occluded for 4 min then released for 10 min. This asphyxial episode was repeated until the arterial pH was approximately 7.00, and the mean arterial blood pressure was less than 40 mmHg and falling. The 13 control lambs were simply exteriorized with the umbilical circulation intact. The lambs were then ventilated for 3-4 h. There were no differences between the control vs. asphyxiated lambs in pulmonary compliances (0.57 and 0.58 ml.cmH2O-1.kg-1) wet-to-dry weight ratios (8.18 and 7.55), cardiac outputs (177.8 and 141.8 ml.kg-1.min-1), surfactant-saturated phosphatidylcholine pool sizes, or atrial and/or ductal shunts. Asphyxia did not interfere with the redirection of blood away from atelectatic lung segments created by bronchial obstruction with balloon catheters. Also, although the bidirectional flux of protein into and out of the airways of these preterm lambs was large relative to term lambs, there was no effect of asphyxia on this protein leak. In this animal model, prenatal asphyxia did not impact negatively on the severity of the respiratory failure.

Animals↗

Clearance of surfactant phosphatidylcholine via the upper airways in rabbits.

A possible route of clearance of surfactant phosphatidylcholine from the lungs is via the airways. To quantify surfactant loss via this pathway, latex bags were surgically placed into the abdomens of adult rabbits such that secretions cleared via the esophagus could be collected. The rabbits then were given treatment or trace doses of radiolabeled phosphatidylcholine-surfactant by tracheal injection and/or intravascular radiolabeled precursors of phosphatidylcholine. Labeled saturated phosphatidylcholine was measured in all fluids that were collected from the bags at 2-h intervals for 24 h and in alveolar washes and lung tissues at 24 h. No more than 7% of either treatment or trace doses of intratracheal surfactant-saturated phosphatidylcholine was lost via clearance up the airways over 24 h. Clearances of endogenously synthesized and secreted saturated phosphatidylcholine were estimated to be no more than 3% of the flux of labeled saturated phosphatidylcholine through the alveolar pool. These experiments demonstrate that surfactant phosphatidylcholine clearance via movement up the airways is not a major pathway leading to surfactant catabolism.

Animals↗

Clearance of treatment doses of surfactant. Effect of lipid extraction and aggregate sizes.

Three-day-old rabbits were given intratracheal injections with a variety of surfactants at doses of about 100 mg lipid/kg, doses commonly used in clinical trials of surfactant for respiratory distress syndrome. Calf and sheep natural surfactants isolated by centrifugation of alveolar washes were compared with Surfactant-TA and two aggregate sizes of lipid solvent extracted sheep surfactant by measuring the percent recoveries of labeled phosphatidylcholine in alveolar washes and lung tissue at times to 48 h after surfactant injection. Surfactant-TA and the lipid extracted surfactants did not contain the 28 to 35-kdalton surfactant protein. All surfactants had similar linear clearance rates from the total lung (alveolar wash plus lung tissue), independent of species source, extraction with lipid solvents, or aggregate sizes of the phospholipids in suspension. There were no metabolic consequences to lipid extraction, the loss of 28-35 kdaltons of protein, or changes in aggregate sizes of surfactant lipids when injected in treatment doses into the airways of 3-day-old rabbits.

Animals↗