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Biomedical subjects

Hiroshi Kawashima

Publications and source records attributed to Hiroshi Kawashima.

At least 19 recordsLinked to original sources

Distribution and metabolism of dihomo-gamma-linolenic acid (DGLA, 20:3n-6) by oral supplementation in rats.

We compared the dietary effects of dihomo-gamma-linolenic acid (DGLA) contained in the DGLA oil produced by a fungus with gamma-linolenic acid (GLA) on the fatty acid composition. Wistar rats were fed with three kinds of oil for two weeks as follows: (i) control group: corn oil; (ii) GLA group: borage oil; (iii) DGLA group: DGLA oil/safflower oil = 55:45. The DGLA concentrations in the liver, serum, and brain of the DGLA group were higher than those of the GLA oil group. We also examined the dose effect of DGLA. The DGLA levels in the liver, serum, and brain significantly increased with increasing dosage of DGLA in the diet. DGLA administration significantly increased the ratio of PGE1/PGE2 in the rat plasma. The mechanism for GLA administration to improve atopic eczema is thought to involve an increase in the concentration of DGLA metabolized from GLA, so these results suggest that the dietary effect of DGLA would be more dominant than GLA.

8,11,14-Eicosatrienoic Acid↗

Altered emotional behavioral responses in mice lacking brain-type fatty acid-binding protein gene.

Brain-type fatty acid-binding protein (B-FABP) belongs to a family of intracellular lipid-binding proteins. B-FABP exhibits a binding affinity to long-chain fatty acids (FAs) whose effects on brain functions including development, emotion, learning and memory have been proposed. B-FABP is localized in the ventricular germinal cells in embryonic brain and astrocytes in developing and mature brain of rodents. In the present study we generated the mouse harboring a null mutation in the B-FABP gene and studied its phenotype. B-FABP mutant mice exhibited the enhanced anxiety and increased fear memory as well as the decreased content of docosahexaenoic acid (DHA) in their brain during the neonatal period without detection of any histological changes in the brain. In the adult brain, B-FABP was localized more numerously to the astrocytes in the amygdala and septal area than to those in the hippocampal area. Analysis of FA content in the amygdala of adult brain revealed that arachidonic and palmitic acids increased significantly in the mutant mice compared with wild-type. Furthermore, the response of N-methyl-d-aspartate receptor-mediated current to DHA in isolated neurons from B-FABP mutant brain was significantly decreased compared with that of wild-type, while no significant differences were detected in behavioral responses related to the spatial learning/memory or in the hippocampal long-term potentiation. These data indicate that B-FABP is crucially involved in the fear memory and anxiety through its binding with FAs and/or its own direct effects on pertinent metabolism/signaling of FAs.

Animals↗

Arachidonic acid improves aged rats' spatial cognition.

To examine the effects of arachidonic acid (AA) on age-related cognitive deficits, F-344 rats were administered with an AA-supplemented powder diet from 79 weeks of age (OA group). For comparison, we also used an age-matched control group of animals (OC group) that were fed with a non AA-supplemented powder diet. When the subjects reached 87 weeks old, they were trained for Morris water maze place and cue tasks. Escape latencies of the OA group on the place task were significantly shorter than those of the OC group in the latter half of training. The probe test showed that OA rats remembered the trained platform position significantly better than OC rats. In the cue task training, the OC group was significantly slower than the OA group at the beginning of training, but their performance soon matched with that of the OA group. Fatty acids in the hippocampi were measured after the behavioral testing. There was no difference in AA composition in hippocampal phospholipids between the OA and OC groups. However, regression analysis conducted on AA composition and place task performance showed a significant correlation between these two parameters. The present study suggests that AA administration to aged animals can alleviate age-related deficits in spatial cognition.

Aging↗

Disappearing cyst of the hepatic hilum in uncorrectable biliary atresia.

A 2-month-old boy with biliary atresia (BA) with an extremely rare prenatal history is reported. A cystic lesion in the hepatic hilum was diagnosed during prenatal ultrasonography at 20 weeks' gestation. However, it disappeared during later prenatal observation. He was diagnosed with an uncorrectable type of BA after a massive subdural hemorrhage at the age of 66 days. A fetus suspected of having a cyst of the biliary tree should be followed even after the cyst has disappeared spontaneously.

Biliary Atresia↗

Molecular evidence that the rate-limiting step for the biosynthesis of arachidonic acid in Mortierella alpina is at the level of an elongase.

The oil-producing fungus Mortierella alpina 1S-4 is an industrial strain for arachidonic acid (AA) production. To determine its physiological properties and to clarify the biosynthetic pathways for PUFA, heterologous and homologous gene expression systems were established in this fungus. The first trial was performed with an enhanced green fluorescent protein gene to assess the transformation efficiency for heterologous gene expression. As a result, strong fluorescence was observed in the spores of the obtained transformant, suggesting that the foreign gene was inherited by the spores. The next trial was performed with a homologous PUFA elongase (GLELOp) gene, this enzyme having been reported to catalyze the elongation of GLA (18:3n-6) to dihomo-gamma-linolenic acid (20:3n-6), and to be the rate-limiting step of AA production. The FA composition of the transformant was different from that of the host strain: The GLA content was decreased whereas that of AA was increased. These data support the hypothesis that the GLELOp enzyme plays an important role in PUFA synthesis, and may indicate how to control PUFA biosynthesis.

Acetyltransferases↗

Thoracoabdominal coarctation of the aorta: surgical repair in a 7-year-old boy.

Atypical coarctation of the lower descending or the abdominal aorta is a relatively rare disease which occurs in about 0.5 to 2% of all coarctation cases. The majority of these diseases present with circumscribed narrowing of the abdominal aorta. However, we treated a 7-year-old boy with a rare form: a long, diffuse hypoplasia of the thoracoabdominal aorta.

Aorta, Abdominal↗

Chest wall mesenchymal hamartoma associated with a massive fetal pleural effusion: a case report.

Abstract We report on an extremely rare chest wall mesenchymal hamartoma associated with a massive fetal pleural effusion. Prenatal ultrasound examination demonstrated a heterogeneous mass in the right thorax associated with a massive pleural effusion and right lung compression at 29 weeks of gestation. The patient underwent pleuroamniotic shunting at 30 weeks and was delivered at 33 weeks by cesarean delivery secondary to fetal distress. After management of the respiratory distress and evaluation of the mass, surgery was performed at day of life 8. Histological examination confirmed the diagnosis of a chest wall mesenchymal hamartoma.

Adult↗

Midterm follow-up study of high-type imperforate anus after laparoscopically assisted anorectoplasty.

PURPOSE: The aim of this study was to evaluate postoperative anal function of high-type imperforate anus after laparoscopically assisted anorectoplasty (LAARP). METHODS: Between 2000 and 2002, LAARP was performed in 13 patients with high-type imperforate anus. Clinical data of the LAARP group were compared with the posterior sagittal anorectoplasty (PSARP) group (n = 7) operated before 2000. All patients were treated with initial colostomy in the newborn period. After anorectoplasty, daily glycerin enemas were given for postoperative bowel management. Anorectal function of these patients was evaluated using the Kelly score and manometry at the age of 3 to 5 years (LAARP) and 5 to 6 years (PSARP). RESULTS: Age at evaluation in the LAARP group was younger than that in the PSARP group (51 +/- 10 vs 73 +/- 12 months, P < .01). Kelly score was 3.8 +/- 1.3 vs 3.4 +/- 0.8, respectively. Resting pressure of internal sphincter was 31 +/- 11 vs 33 +/- 10 cm H(2)O, respectively. Relaxation reflex of the internal anal sphincter was observed in 62% (8/13) and 29% (2/7), respectively. CONCLUSIONS: Midterm follow-up study revealed that satisfactory fecal continence can be achieved in patients with high-type imperforate anus after LAARP. Laparoscopically assisted anorectoplasty may be a good alternative in this patient population. However, long-term follow-up is necessary to compare the benefits of LAARP against PSARP.

Anal Canal↗

Improvement of the fatty acid composition of an oil-producing filamentous fungus, Mortierella alpina 1S-4, through RNA interference with delta12-desaturase gene expression.

An oleaginous fungus, Mortierella alpina 1S-4, is used commercially for arachidonic acid production. Delta12-Desaturase, which desaturates oleic acid (18:1n-9) to linoleic acid (18:2n-6), is a key enzyme in the arachidonic acid biosynthetic pathway. To determine if RNA interference (RNAi) by double-stranded RNA occurs in M. alpina 1S-4, we silenced the Delta12-desaturase gene. The silenced strains accumulate 18:2n-9, 20:2n-9, and Mead acid (20:3n-9), which are not detected in either the control strain or wild type strain 1S-4. The fatty acid composition of stable transformants was similar to that of Delta12-desaturation-defective mutants previously identified. Thus, RNAi occurs in M. alpina and could be used to alter the types and relative amounts of fatty acids produced by commercial strains of this fungus without mutagenesis or other permanent changes in the genetic background of the producing strains.

Arachidonic Acid↗

Transformation of oil-producing fungus, Mortierella alpina 1S-4, using Zeocin, and application to arachidonic acid production.

The arachidonic acid-producing fungus Mortierella alpina 1S-4, an industrial strain, was endowed with Zeocin resistance by integration of the Zeocin-resistance gene at the rDNA locus of genomic DNA. Plasmid DNA was introduced into spores by microprojectile bombardment. Twenty mg/ml Zeocin completely inhibited the germination of M. alpina 1S-4 spores, and decreased the growth rate of fungal filaments to some extent. It was suggested that preincubation period and temperature had a great influence on transformation efficiency. Four out of 26 isolated transformants were selected. Molecular analysis of these stable transformants showed that the plasmid DNA was integrated into the rDNA locus of the genomic DNA. We expect that this system will be applied for useful oil production by gene manipulation of M. alpina 1S-4 and its derivative mutants. On the basis of the fundamental transformation system, we also tried to overexpress a homologous polyunsaturated fatty acid elongase gene, which has been reported to be included in the rate-limiting step for arachidonic acid production, thereby leading to increased arachidonic acid production.

Arachidonic Acid↗

Establishment of an overall transformation system for an oil-producing filamentous fungus, Mortierella alpina 1S-4.

Oil-producing fungus Mortierella alpina 1S-4 is an industrial strain. To determine its physiological properties and to clarify the biosynthetic pathways for polyunsaturated fatty acids, a transformation system for this fungus was established using a derivative of it, i.e., a ura5- mutant lacking orotate phosphoribosyl transferase (OPRTase, EC.2.4.2.10) activity. Transformation with a vector containing the homologous ura5 gene as a marker was successfully performed using microprojectile bombardment, other methods frequently used for transformation, such as the protoplasting, lithium acetate, or electroporation methods, not giving satisfactory results. As a result, two types of transformants were obtained: a few stable transformants overexpressing the ura5 gene, and many unstable transformants showing OPRTase activity comparable to that of the wild-type strain. The results of quantitative PCR indicated that the stable transformants could retain the ura5 genes originating from the transformation vector regardless of the culture conditions. On the other hand, unstable transformants easily lost the marker gene under uracil-containing conditions, as expected. In this paper, we report that an overall transformation system for this fungus was successfully established, and propose how to select useful transformants as experimental and industrial strains.

Acetates↗

Anorectal agenesis with a rectourethral fistula diagnosed in an adult: report of a case.

We report an unusual case of anorectal agenesis with a rectourethral fistula diagnosed in a 48-year-old man. The patient presented after noticing hematuria, although he had been aware of urinary leakage from his colostomy with occasional fecal urine for about 4 years. He had had a double-barrel colostomy created soon after birth for an imperforate anus, with revision at the age of 4 years to correct a prolapse of the stoma, but his malformation had never been repaired. We performed a physical examination, which did not reveal a perineal fistula, but urethrocystography demonstrated high anorectal agenesis with a rectourethral fistula. Thus, we resected the rectourethral fistula and created an end-colostomy. The patient had an uneventful postoperative course, and was discharged in good health on postoperative day 19. To our knowledge, this is the oldest patient to be diagnosed with anorectal agenesis and undergo resection of a rectourethral fistula.

Anus, Imperforate↗

Complications of laparoscopic surgery in neonates and small infants.

PURPOSE: The difficulty of performing laparoscopic surgery in small infants remains a common complaint of pediatric surgeons. The aim of this study was to evaluate the complications of laparoscopic surgery in small infants weighing less than 5 kg. METHODS: Since 1997, 154 infants weighing less than 5 kg underwent laparoscopic surgery (group S). During that same period, 96 infants weighing less than 10 kg (group M) and 335 children weighing more than 10 kg (group L) also underwent laparoscopic surgery. Intra- and postoperative complications were evaluated and compared between the 3 groups, especially in the 60 cases that underwent Nissen fundoplication. P < .05 was considered a significant difference. RESULTS: Complications such as gastrointestinal perforation and wound infection were observed in 15 (9.7%), 15 (15.6%), and 32 (9.6%) infants of groups S, M, and L, respectively. There were no significant differences in complication rates among the 3 groups. However, in Nissen fundoplication, 5 of 15 patients in group S had complications, thereby significantly increasing the complication rate as compared with group L (1 of 23, P = .04). Major complications in group S were gastrointestinal perforation and vagal nerve injury. CONCLUSIONS: Laparoscopic surgery is feasible even in small infants. However, in Nissen fundoplication, special attention is necessary to avoid severe intraoperative complications.

Adolescent↗

Effect of dietary enrichment with n-3 polyunsaturated fatty acids (PUFA) or n-9 PUFA on arachidonate metabolism in vivo and experimentally induced inflammation in mice.

Mice were fed a diet supplemented with palm oil (control diet), n-3 polyunsaturated fatty acids (PUFA)-, or n-9 PUFA-rich oil for 3 weeks. The n-3 PUFA-rich diet suppressed the generation of both leukotrienes (LT) and prostaglandins (PG), but the n-9 PUFA-rich diet did LT but not PG generation during acute inflammation. Leukocyte accumulation during acute inflammation was not different in the n-3 or n-9 PUFA-rich diet group as compared with the control group. The n-3 PUFA-rich diet but not the n-9 PUFA-rich diet suppressed Freund's adjuvant-induced granuloma formation. The n-9 PUFA-rich diet significantly attenuated galactosamine/lipopolysaccharide-induced liver injury more effectively than the n-3 PUFA-rich diet as compared with the control diet. The present study revealed the differential modification of experimentally induced inflammation in mice by dietary n-3 PUFA and n-9 PUFA, which may be due to their different effects on 5-lipoxygenease and cyclooxygenase metabolism of arachidonic acid during inflammatory processes.

Acute Disease↗

Cloning and sequencing of the ura3 and ura5 genes, and isolation and characterization of uracil auxotrophs of the fungus Mortierella alpina 1S-4.

The oil-producing fungus Mortierella alpina 1S-4 is an industrial strain. In order to prepare host strains for a transformation system for this fungus, six uracil auxotrophs were obtained by means of random mutation with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). When the activities of orotate phosphoribosyl transferase (OPRTase, EC 2.4.2.10) and orotidine-5'-phosphate decarboxylase (OMPdecase, EC 4.1.1.23) were examined in the mutants and wild strain, OPRTase activity was found to be completely absent in all mutants, on the other hand, OMPdecase activity was intact. The genomic DNA and cDNA of the ura5 gene encoding OPRTase and the ura3 gene encoding OMPdecase were cloned and sequenced. The Ura5p deduced amino acid sequence of this fungus showed highest similarity to that of Vibrio cholerae classed among prokaryote. Furthermore, the mutational points in the ura5 genes of two selected mutants were identified; a base-replacement and a base-insertion.

Amino Acid Sequence↗

Endosurgical procedures for pediatric solid tumors.

The aim of this study was to evaluate the advantages and complications of endosurgical procedures for benign and malignant pediatric solid tumors. Endosurgical techniques of biopsy and excision were used for diagnosis and treatment of solid tumors, respectively. Since July 1997, a total of 24 biopsies and 24 excisions have been performed laparoscopically for neuroblastoma ( n=24), ovarian solid tumors ( n=10) and other tumors. Seventeen biopsies and six excisions were performed for abdominal neuroblastoma, while ten excisions were performed for ovarian tumor. In these patients, the length of the operation, blood loss, time to start postoperative feeding, time to start postoperative chemotherapy and length of hospital stay were evaluated and compared to the those of the open surgery group. Furthermore, intra- and postoperative complications were analyzed in all patients of both groups. The length of the hospital stay and time to start postoperative feeding were significantly shorter in the group of patients who underwent endosurgical procedures for either abdominal neuroblastoma or ovarian tumor when compared to the open procedure group. The time to start postoperative chemotherapy was shorter only in the abdominal neuroblastoma group. The procedure for two patients undergoing endosurgical tumor excision had to be converted to open surgery due to large tumor size. Two weeks after thoracoscopic excision of a dumb bell-type neurofibroma, one patient underwent open repair of the dura mater because of leakage of cerebrospinal fluid. There were no port-site recurrences in any tumor types. Endosurgical procedures for solid tumors are effective and minimally invasive. However, better indicators are needed for their implementation in order to prevent complications and subsequent conversions to open procedures.

Abdominal Neoplasms↗