Familial hypocholinesterasemia found in a family and a new confirmed mutation

A 45-year-old man was hospitalized because of acute hepatitis. His serum cholinesterase (ChE) was below 10 IU/l (normal range: 105-240 IU/l) during the disease course and after his recovery. The patient was suspected of having familial hypocholinesterasemia. His family members were healthy except that his father had hypertension and gall stones. Analysis of ChE gene in the propositus and his family revealed three point mutations at nucleotides 298 (CCA to TCA), 1,410 (CGT to CGG) and 1,615 (GCA to ACA). The first mutation caused an amino acid change at codon 100 from proline to serine, which was a new mutation not previously reported, but the second one was a silent mutation. The third mutation resulted in an amino acid alteration from alanine to threonine at codon 539 in exon 4 of the ChE gene. The mode of transmission of these mutations is described.

The regulatory effect of fermentable sugar levels on the production of leukotoxin by Actinobacillus actinomycetemcomitans

The relationship between sugar availability and RTX (repeats in toxin) cytotoxin (leukotoxin) production in the periodontopathic bacterium, Actinobacillus actinomycetemcomitans, was investigated using a chemostat. A actinomycetemcomitans 301-b produced significant amounts of leukotoxin in anaerobic fructose-limited chemostat cultures at a dilution rate of 0.15 h-1 and at pH 7.0. When the growth limitation was relieved by pulsing the cultures with 50 or 150 mM fructose (final concentrations), leukotoxin production immediately stopped and the amount of cellular leukotoxin decreased until the culture was returned to fructose-limited conditions. Leukotoxin synthesis was also repressed in the chemostat cultures by pulsing with glucose but not with the non-fermentable sugar analog, alpha-methyl-D-glucoside. Leukotoxin production was also repressed by fructose in chemostat cultures of ATCC 33384, which is generally recognized as a non-leukotoxin-producing or minimally leukotoxic strain.

Cystoid macular edema as an initial symptom of inflammatory orbital pseudotumor

We report a patient with pseudotumor with cystoid macular edema (CME). The initial finding in our case was only CME with a bilateral visual acuity decrease to 20/25. Approximately 3 months later, the visual acuity dropped to light perception in the right eye and 20/200 in the left eye. Computed tomography scan revealed a mass in the right orbital apex and band-shaped enhancement in the cavernous sinus and along the upper margin of the petrous bone. However, no mass was found intraoperatively, and a biopsy specimen of the bulging levator muscle showed polymorphonuclear leukocyte infiltration. The CME resolved postoperatively. The tumor also seemed to resolve; however, after 1 year, the tumor recurred and invaded the brain tissue. A temporal lobectomy revealed widespread inflammatory cell infiltration. To ensure early diagnosis, pseudotumor should be considered in patients with CME of which the cause is uncertain.

Expression of integrin subunits in normal and malignant human salivary gland cell clones and its regulation by transforming growth factor-beta 1

In this study, we have examined the expression of integrin subunits in normal and malignant human salivary gland cell clones as well as its regulation by transforming growth factor-beta 1 (TGF-beta 1). By the analysis using immunofluorescence staining, an SV40 immortalized normal human salivary gland duct cell clone (NS-SVDC) with no tumorigenic ability by s.c. implantation into nude mice was identified to express the integrin beta 1, alpha 2, alpha 3 and alpha 6 subunits on the cell surface, while the expression of these subunits, except for beta 1 subunit, was reduced or completely diminished in a neoplastic human salivary gland duct cell clone (HSGc) with tumorigenic but not metastatic potential in nude mice and metastatic cell clones derived after in vitro exposure of HSGc to N-methyl-N-nitrosourea. In addition, immunoblot analysis also exhibited the same results as those obtained with immunofluorescence staining. The alpha 1 subunit was not demonstrable in any of the cell clones by both techniques. TGF-beta 1 augmented the expression of the beta 1 subunit in NS-SV-DC, while HSGc and metastatic cell clones demonstrated no changes in the expression of the beta 1 subunit in response to TGF-beta 1. These findings, therefore, suggest that there is an inverse relationship between the malignancy and the expression mode of integrin subunits, especially alpha 2 subunit, in human salivary gland cell clones with varying degrees of malignant potential, and that TGF-beta 1 is a positive regulatory factor in the expression of the beta 1 subunit in normal but not malignant cell clones.

Tomographic distribution of acetylated histone H4 in plant chromosomes, nuclei and nucleoli

Root tip cells of broad bean (Vicia faba L. cv. 'Wase soramame') and barley (Hordeum vulgare L. cv. 'Minorimugi') were immunostained with antibodies specific for acetylated histone H4. With an antiserum that recognizes histone H4 acetylated at lysine-5, the nucleolar organizing region (NOR) in mitotic chromosomes was strongly labeled in both species. The broad bean had two signals in the metaphase and telophase chromosome complements and four signals in the prophase and anaphase chromosome complements, while the barley had four signals in the metaphase and telophase chromosome complements and eight signals in the prophase and anaphase complements. Five different patterns of signals were observed at interphase: in type I only nucleoli were wholly stained; in type II perinucleolar knob-like signals and/or fiber-like signals emanated from the nucleus; in type III aggregate signals appeared in the nucleolus; in type IV many small dot-like signals were distributed throughout the nucleus, except nucleoli; and in type V string-like or some granule-like signals appeared in the nucleoli. Type II was very similar to previous results by in situ hybridization with sense rDNA probes. Type III was similar to the patterns of DNA synthesis recognized as chromatin domains by anti-BrdU antibodies. Type V was very similar to the results of in situ hybridization with pTa71, rDNA probes and the appearance of the dense fibrillar components of the nucleolus.

Uptake of radioactive octanoate in astrocytoma cells: basic studies for application of [11C]octanoate as a PET tracer

Fatty acids are taken up and metabolized in the brain. In vitro uptake experiments on astrocytoma cells were carried out to assess the potential use of [1-11C]octanoate as a positron emission tomography (PET) tracer for astroglial functions. Uptake of [1-14C]octanoate increased in a time-dependent fashion until 60 min after application. The uptake of [1-11C]octanoate showed similar results to that of [1-14C]octanoate until 10 min. As for medium pH, [1-14C]octanoate uptake increased gradually with the decrease in pH. We also examined the effects of glutamate, glucose deprivation and hypoxia on the uptake of octanoate and found that these conditions did not bring about any change in the extent of [1-14C]octanoate uptake. These results show that the octanoate uptake was not influenced by any of several pathological conditions. When the number of astrocytes increases in the area of hypoglycemia or hypoxia near a brain lesion, the amount of octanoate uptake also increases, so this indicates the possibility that 11C-octanoate will detect a brain lesion.

The acridine ring selectively intercalated into a DNA helix at various types of abasic sites: double strand formation and photophysical properties

The interactions between the intercalating agent and the three types of abasic sites: abasic frameshift, apurinic and apyrimidinic, were investigated. 9-amino-6-chloro-2-methoxyacridine (ACMA), whose spectroscopic properties are strongly perturbed by the environment, was selected as the intercalating agent. The optically pure threoninol derived from the reduction of L-threonine was used as an artificial abasic site mimicking the ring-opened natural ribose. In order to secure the selective intercalation to the adjacent abasic site, ACMA and the abasic site were connected through a tri- pentamethylene linker. These modified oligonucleotides covalently linked to an ACMA molecule at the internucleotide site having the same base-sequence were synthesized using the acridine-phosphoramidites. Although all the modified oligonucleotides lack a nucleobase at the intervening position, these double strands showed high thermal stability. The pentamethylene linker and the apyrimidinic systems were especially stabilized. At the same time, sharpness of the absorption spectra and a new fluorescent band of the acridine, due to the fixation of the environment around ACMA, were observed. Therefore, it is concluded that the acridine binds preferentially to the apyrimidinic site rather than the frameshift abasic site and that the surroundings of the acridine are strictly fixed at the microenvironmental level.

[Three cases of acute subdural hematoma in abused children]

We encountered 3 cases of battered children with acute subdural hematoma. In this report, we discuss the difficulties in treating this condition surgically, and we emphasize the importance of early diagnosis and treatment of abused children and their parents. Case 1: A girl, aged 2 months, was brought in by her mother, because the child had become drowsy. The mother stated that the child had been battered by her father. Physical examination revealed tense anterior fontanelle, bruises on her face, consciousness disturbance and retinal bleeding. Marked anemia was revealed on laboratory studies. A computed tomographic (CT) scan demonstrated an interhemispheric subdural hematoma in the parietooccipital region. She was treated conservatively for 2 months. Follow-up CT revealed a bilateral chronic subdural hematoma. Burr hole irrigation and drainage on both sides brought about complete disappearance of these lesions. Case 2: A girl, aged 1 year and 9 months, was brought in by her parents. According to her mother's allegation, the child fell down from the top of an indoor slide and became comatose. Physical examination revealed severe malnutrition, loss of consciousness, dilated pupils and negative light reflex. Numerous areas of subcutaneous bleeding and skin erosions were seen on her back and abdomen. Marked anemia was revealed on laboratory studies. CT scan demonstrated a left acute subdural hematoma and massive brain swelling. Despite an emergency craniotomy, the child died 5 days later. Case 3: A 4-year-old boy was admitted in a comatose state. According to his mother's allegation, he was thrown to the floor from a 1.5m height and struck against a wall by his father. Physical examination revealed severe malnutrition, consciousness loss, dilated pupils and negative light reflex. Many scratches and bruises were seen over his whole body, especially on his back. Marked anemia was revealed on laboratory studies. A CT scan demonstrated a left acute subdural hematoma and massive brain swelling. Three days later, he died despite emergency craniotomy. The incidence of battered children is increasing in Japan, and these cases sometimes involve severe head injuries, such as subdural hematoma. In these cases, successful surgical treatment is difficult after admission to the neurosurgical institute. This may result from late admission as well as marked anemia and malnutrition. Therefore, we conclude that early diagnosis of child abuse and treatment of the abused child and psychological treatment for their parents are very important.

Characterization of heterochromatic regions in 'Trovita' orange (Citrus sinensis Osbeck) chromosomes by the fluorescent staining and FISH methods

CMA/DAPI double staining and FISH methods using rDNA and telomere specific repeated sequences as probes were applied to characterize the large amount of heterochromatin in the telomeric regions of 'Trovita' orange (Citrus sinensis Osbeck) chromosomes. As a result, all the heterochromatic regions were CMA+/DAPI-, and thus were GC rich. Three CMA+/DAPI- heterochromatic regions were positive to the 26S rDNA probe. Telomere arrays consisting of Tm(A)Gn were detected on the extreme ends of each chromosome and most of the CMA+/DAPI- heterochromatic regions were ordered close inside the telomere-specific repeated sequences. The data obtained in this study will be useful for karyotyping, systematics, and molecular analysis of orange chromosomes.

[Usefulness of the preoperative MRI for diagnosis and operative method in a case of cor triatriatum]

A case was 6-year-old female diagnosed as the cor triatriatum. The magnetic resonance imaging synchronized at R wave on the electrocardiogram was performed in order to see the abnormal septum in the left atrium. In the horizontal view, the abnormal septum that divides the left atrium into the accessory left atrial chamber and the true left atrium, was well visualized. This septum lied on the vertical portion. Operation was carried out with the approach through the accessory chamber and the fibromuscular membrane were excised. Preoperative imaging of the MRI was useful and helpful for us to reach to a decision of the surgical approach in this patient.

[Inappropriate preservation of myocardium by topical cooling with iced slush]

Topical cooling with iced slush has been applied as a conventional myocardial preservation in open heart surgery. However, there might be several disadvantages due to topical cooling with iced slush which melted to be liquid, because of membrane integrity decreased during ischemia. To understand more detailed mechanism of deterioration for myocardium by immersion in some liquid during ischemia, we subjected isolated crystalloid perfused rabbit hearts to a 30 minute of ischemia with immersion in Krebs-Henseleit (K-H) solution (I), K-H+hexamethlyamiloride which was Na+/H+ channel blocker (II) and histidine containing cardioplegia (HBS) designed to accelerate anaerobic glycolysis by a proton buffering (III), followed by a 30 minute of reperfusion. These groups were compared to the hearts hanging in air during ischemia (control). Phosphocreatine (PCr), ATP and intracellular pH were measured by 31 PNMR in group I, II, III. Developed pressure (Dev P) and diastolic pressure (EDP) with a intracavitary balloon were also evaluated with monitoring of 2 mmHg diastolic contracture during ischemia. Dev P declined to 46%, 54% of preischemic value in group I and group II, respectively, although % recovery of control heart was 74% after ischemia-reperfusion process. Diastolic function was severely deteriorated in group I and II, as compared to control heart. ATP and intracellular pH showed a similar decline as PCr in group I and II which was not seen in group III during ischemia. HBS prevented the deterioration of PCr, ATP and intracellular pH during ischemia along with excellent recovery of myocardial function. We therefore conclude that 1) significant deterioration of myocardium occurs with ischemia if the heart preserved in Krebs-Heseleit solution and the mechanism of injury by immersion in liquid on the heart appears to be due to proton accumulation caused by intracellular acidification and loss of high energy phosphate.

Cerebral cysticercosis manifesting as hydrocephalus--case report

A 70-year-old female presented with gait disturbance and dementia. Cerebrospinal fluid examination revealed mild aseptic meningitis. Magnetic resonance images showed multiple cystic lesions and mural nodules in some of the cysts in the cerebral parenchyma. Metrizamide computed tomography clearly demonstrated multiple intracisternal cysts. Some cysts were surgically excised and a ventriculoperitoneal shunt was implaced. Postoperatively, her gait disturbance and dementia disappeared. Histological examination revealed cysticercosis with viable larva. Ten months after the initial surgery, she presented with right hemiparesis due to enlargement of the remaining cysts in the left frontal lobe. These cysts were removed. Postoperative neurological examination showed slight right hemiparesis. We recommend ventriculoperitoneal shunting for hydrocephalus due to cisternal cysticercosis and praziquantel administration for parenchymal lesions.

[A case of inflammatory pseudotumor of the lung with suppressed immune response in the patient with renal cell carcinoma after nephrectomy and administration of interferon]

A 60-year-old man with renal cell carcinoma was treated of right nephrectomy and high dose administration of Interferon-alpha (IFN) in 1990. Three and half years after operation, he complained of cough and hemoptysis. Chest X-ray showed a abnormal shadow (5.5 x 3.5 cm) in the upper lung field. On chest CT, a tumor mass with small cavity was located at S2, attended with the speculation and pleural indentation. A rough nodule suspected daughter tumor was pointed out near the tumor mass. Laboratory investigation revealed mild leucocytosis, an elevated ESR and C reactive protein. On lymphocyte subset, CD 4/8 ratio was 0.8 and NK cell activity was 11%. Immunosuppressive acid protein (IAP) in serum was 1,137 ng/ml. No organisms or malignant cells could be demonstrated in the biopsy materials or sputum. Right thoracotomy and upper lobectomy was carried out. Postoperative pathological diagnosis was inflammatory pseudotumor. Namely, the lesion was occupied with variable admixture of lymphocytes, plasma cells, histiocytes, phagocytes included hemosiderin, foam cells and whorled fibrosis. Daughter tumor was scar tissue. Now, he is well without recurrence and his immune response is within normal level. Some discussion of the literature was mentioned.

Different effects of various phospholipids on Ki-Ras-, Ha-Ras-, and Rap1B-induced B-Raf activation

We have recently purified a Ki-Ras- and Ha-Ras-dependent extracellular signal-regulated kinase kinase from bovine brain and identified it as B-Raf protein kinase complexed with 14-3-3 proteins (Yamamori, B., Kuroda, S., Shimizu, K., Fukui, K., Ohtsuka, T., and Takai, Y. (1995) J. Biol. Chem. 270, 11723-11726). Moreover, we found that Rap1B as well as Ki-Ras and Ha-Ras stimulate the B-Raf activity. Since B-Raf contains a cysteine-rich domain originally found in protein kinase C as a domain responsible for interaction with phosphatidylserine (PS) and diacylglycerol or 12-O-tetradecanoylphorbol-13-acetate, we have examined here the effect of these compounds on the Ki-Ras-, Ha-Ras-, and Rap1B-induced activation of bovine brain B-Raf. Bovine brain PS enhanced Ki-Ras-stimulated B-Raf activity. Phosphatidic acid was slightly active, but other phospholipids, such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol (PI), PI-4-monophosphate, PI-4,5-bisphosphate, and PI-3,4,5-trisphosphate, were inactive. However, none of the above phospholipids affected the Ha-Ras-stimulated B-Raf activity, whereas PI, PS, phosphatidylethanolamine, and phosphatidic acid inhibited the Rap1B-stimulated B-Raf activity. Phosphatidylcholine or PI-4-monophosphate did not show any effect on the Rap1B-stimulated B-Raf activity. Synthetic PS with two unsaturated fatty acids, such as 1,2-dioleoyl-PS or 1,2-dilinoleoyl-PS, showed the same effect toward the Ki-Ras- and Rap1B-stimulated B-Raf activities, but synthetic PS with two saturated fatty acids, such as 1, 2-distearoyl-PS, was inactive. 12-O-Tetradecanoylphorbol-13-acetate did not affect the stimulatory or inhibitory effect of PS on the Ki-Ras- and Rap1B-stimulated B-Raf activities, respectively. PS did not affect the Ki-Ras-, Ha-Ras-, or Rap1B-independent basal B-Raf activity or the mitogen-activated protein kinase kinase or extracellular signal-regulated kinase activity. These results indicate that various phospholipids differently affect Ki-Ras-, Ha-Ras, and Rap1B-induced B-Raf activation.

[Emergency surgical salvage for a type A early thrombosed aortic dissection complicated cardiac tamponade in a 80-year-old-patient]

A 80-year-old woman underwent emergency operation for a type A early thrombosed aortic dissection associated with cardiac tamponade. Her preoperative chest CT (not enhanced) showed high density area in the false lumen that indicated early thrombosis and the projection of true lumen at antero-left-lateral portion of ascending aorta that means "ulcer-like projection" called on aortogram. After the relief of the cardiac tamponade by pericardiocenthesis, we emergently performed the graft replacement of the ascending aorta under the extracorporeal circulation combined with selective cerebral perfusion. Her postoperative course was uneventful and satisfactory.

Different signalling pathways involved in transforming growth factor-beta 1-induced morphological change and type IV collagen synthesis in simian virus-40-immortalized normal human salivary gland duct and myoepithelial cell clones

To understand the specific cell type responsible for the synthesis of basement membrane components of the salivary gland, the effects of transforming growth factor (TGF)-beta 1 on morphological change, cellular proliferation and collagen synthesis were examined in these immortalized duct and myoepithelial cell clones, and the expression forms of their TGF-beta receptors analysed. When TGF-beta 1 was added to the cell clones in vitro, it induced a morphological alteration, with flattening in myoepithelial but not in duct cells. Although the growth of Mv1Lu mink lung epithelial cells was almost completely inhibited by TGF-beta 1, the duct and myoepithelial cells were partially resistant to such inhibition. By immunoblot analysis of immunoprecipitates, p53 was found bound to the simian virus-40 large T antigen, suggesting a functional loss of p53 in regulation of cell-cycle arrest. In the cloned myoepithelial cells but not the duct cells, TGF-beta 1 stimulated the production of type IV collagen. To attempt to understand the distinct responsiveness of cell clones to TGF-beta 1, the expression forms of TGF-beta receptors were examined by affinity cross-linking. Although the intensities of the cross-linked bands of the TGF-beta type II and type III receptors, particularly the type II, were weaker in the duct than the myoepithelial cell clones, the expression of the type II receptor mRNA was consistently detected in both clones. Accordingly, the reduction of TGF-beta 1 binding may have occurred at the post-transcriptional level. These findings imply that the cloned myoepithelial cells but not the cloned duct cells produce type IV collagen in response to TGF-beta 1 through the receptor-mediated signal transduction pathway, which is presumably disrupted in the cloned duct cells.

Synthesis and properties of an oligonucleotide modified with an acridine derivative at the artificial abasic site

The synthesis of an oligodeoxynucleotide (ODN) modified with 2-methoxy-6-chloro-9-aminoacridine (Acr) at an abasic site is described. A stereochemically defined aminodiol, L-threoninol, was used to serve as artificial abasic nucleoside. The molecule was modified so as to be suitable for the standard phosphoramidite method and was incorporated into the interior of an ODN. In addition, N-hydroxysuccinimidyl N-[9-(6-chloro-2-methoxy)acridinyl]-6-aminocaproate has been synthesized for postsynthetic modification of the amino substrate of the L-threoninol moiety in the ODN. By using absorption spectroscopy, it is shown that oligo(dA) conjugated with acridine binds with complementary strand in a 1:1 ratio. The melting temperature showed that the nonmodified (abasic) duplex is destabilized as a result of lacking in base at the abasic site, but the covalently linked acridine ring compensates for the destabilization effect. The fluorescence quantum yield of the acridine ring was enhanced by connection to oligo(dA) and, further, by formation of a double-strand with the complementary ODN. The quantum yield is larger than that of intermolecular intercalation. The excitation spectra of Acr-ODN in the duplex is quite similar to the absorption spectra. The results indicate that the covalently linked acridine ring is selectively intercalated into the adjacent abasic site.

Novel FNR homologues identified in four representative oral facultative anaerobes: Capnocytophaga ochracea, Capnocytophaga sputigena, Haemophilus aphrophilus, and Actinobacillus actinomycetemcomitans

Based upon DNA sequence data and positive immunochemical reactivity of expressed protein, novel homologues of the FNR family were identified in four representative oral facultative anaerobes: Capnocytophaga ochracea, Capnocytophaga sputigena, Haemophilus aphrophilus, and Actinobacillus actinomycetemcomitans. The similarity to E. coli FNR and to HlyX (itself 71% similar to E. coli FNR, while regulating expression of hemolysin operon in Actinobacillus pleuropneumoniae) was estimated from the deduced partial amino acid sequence to be, in the above order of tested species, 98, 98, 86, and 85%, and 75, 75, 88, and 88%, respectively. The phylogenetic relatedness indicates a rather closer link of HlyX to the FNR homologues from both pathogens, H. aphrophilus and A. actinomycetemcomitans. The possibility that the A. actinomycetemcomitans FNR homologue functions as a redox-sensing transcriptional factor to regulate, in addition to anaerobic respiration, microaerobic expression of the leukotoxin operon (ltx gene) is suggested.

Phosphorylation of Munc-18/n-Sec1/rbSec1 by protein kinase C: its implication in regulating the interaction of Munc-18/n-Sec1/rbSec1 with syntaxin

Munc-18/n-Sec1/rbSec1 interacts with syntaxin and this interaction inhibits the association of vesicle-associated membrane protein (VAMP)/synaptobrevin and synaptosomal-associated protein of 25 kDa (SNAP-25) with syntaxin. Syntaxin, VAMP, and SNAP-25 serve as soluble N-ethylmaleimide-sensitive fusion protein attachment protein (SNAP) receptors essential for docking and/or fusion of synaptic vesicles with the presynaptic plasma membrane. Genetic analyses in yeast, Caenorhabditis elegans, and Drosophila suggest that Munc-18 is essential for vesicle transport. On the other hand, protein kinase C (PKC) stimulates Ca2+-dependent exocytosis in various types of secretory cells. However, the modes of action of Munc-18 and PKC in vesicle transport have not been clarified. Here, we show that recombinant Munc-18 is phosphorylated by conventional PKC in a Ca2+- and phospholipid-dependent manner in a cell-free system. About 1 mol of phosphate is maximally incorporated into 1 mol of Munc-18. The major phosphorylation sites are Ser306 and Ser313. The Munc-18 complexed with syntaxin is not phosphorylated. The PKC-catalyzed phosphorylation of Munc-18 inhibits its interaction with syntaxin. These results suggest that the PKC-catalyzed phosphorylation of Munc-18 plays an important role in regulating the interaction of Munc-18 with syntaxin and thereby the docking and/or the fusion of synaptic vesicles with the presynaptic plasma membrane.

[Basic amino acid, L-arginine aggravates ischemia-reperfusion injury]

Basic amino acid, L-arginine has been known to have several biological actions including nitric oxide production. The real effects caused by L-arginine administration to heart has not been fairly understood in the setting of ischemia-reperfusion process. The effects of L-arginine on recovery of myocardial contractile function and oxidative metabolism were studied in a model of reversible global normothermic ischemic injury using an isolated, buffer-perfused rabbit heart preparation. 1 mM L-arginine or vehicle was infused into hearts for 2 minutes at the onset of 35 minutes of ischemia in L-arg. group or in control group, respectively. Oxygen consumption (MVO2), lactate release into coronary vessels, and cardiac function including developed pressure, +dp/dt, -dp/dt and diastolic pressure-volume relationship (PVR) were measured and high energy phosphates were also evaluated by 31P-NMR spectroscopy. Endothelial function was also evaluated by acetylcholine (Ach) infusion with monitoring of constant perfusion pressure. L-arginine caused a significant increase in the PVR and profund decline in systolic function when compared to control group. MVO2 was significantly impaired to cause a decrease of high energy phosphates (phosphocreatine and ATP). Lactate release into coronary vessels on reperfusion was significantly higher in L-arg group than that in control group, suggesting a promotion of anaerobic glycolysis. Deterioration of endothelial function and smooth muscle function of artery were evidenced by Ach infusion test. Although the mechanisms of injury are speculatory, possible mechanisms of this injury are stimulation of nitric oxide production by L-arginine and cation change, especially calcium accumulation. We concluded that L-arginine was able to cause aggravation of ischemia-reperfusion injury with reduced contractile function and mitochondrial function and increased anaerobic glycolysis after ischemia-reperfusion in an isolated model of reversible ischemic injury.

Selective increase in astrocytic elements in the rat dentate gyrus after chronic toluene exposure studied by GFAP immunocytochemistry and electron microscopy

Using glial fibrillary acidic protein (GFAP) immunohistochemistry, and electron microscopy, we examined changes in the features of astrocytes in the dentate gyrus of the hippocampal formation after high-dose chronic toluene inhalation (2000 ppm, 4 h/day) for 1 month. In toluene-treated rats, the numbers of GFAP-immunoreactive (IR) astrocytes were not changed, whereas the area and intensity of GFAP-IR processes were increased markedly in the dentate gyrus. In addition, dense, thick and highly-stained GFAP-IR processes appeared entering into the granular cell layer, compared with those of controls. At the electron microscopic level, numerous astrocytic processes with high electron density intervened between the granular cells. These results suggest that high-dose of chronic toluene exposure induces morphological changes in astrocytes in the dentate gyrus of the hippocampal formation.

A fetal intestinal-type alkaline phosphatase produced in Caco-2 cells

Enzymic, immunological and lectin-binding properties of alkaline phosphatase (AP) produced in Caco-2 cells, a human colon carcinoma cell line, were investigated. The enzyme was very similar to fetal intestinal (meconium) AP in the enzymic and immunological properties, but different from fetal intestinal AP in lectin-binding properties; expression of the galactose moiety was altered in AP of Caco-2 cells, compared to that of fetal intestinal AP. These results indicate that AP of Caco-2 cells can be used in place of fetal intestinal AP when the enzymic properties of an AP of unknown origin are investigated, but cannot be used instead of fetal intestinal AP in the structural study of AP.

Absorption and metabolism of lipids in rats depend on fatty acid isomeric position

This study determined the effect of dietary (dipalmitoyl) triacylglycerol (TAG) structure on the absorption and metabolism of fat in the presence or absence of cholesterol. Sprague-Dawley male rats weighing approximately 180 g were fed diets containing 10 g/100 g diet 1,3-dipalmitoyl-2-oleoyl-glycerol-rich oil (POP) or 1(3),2-dipalmitoyl-3(1)-oleoyl-glycerol-rich oil (PPO), either with or without cholesterol supplementation (0.5 g/100 g diet), for 2 wk. There were no differences in the growth of rats fed the various diets. The apparent absorption efficiency of dietary fat especially the apparent absorption efficiency of palmitic acid, was significantly lower in the POP groups than in the groups fed the PPO diets. The excretion of cholesterol in feces of rats fed the POP diet with cholesterol was significantly greater than those fed the PPO diet containing cholesterol. The excretion of total bile acids in the rats fed cholesterol was significantly greater than in those fed the diets without cholesterol. Liver cholesterol was significantly greater in rats fed cholesterol and was not affected by the TAG structure. Plasma cholesterol was significantly lower in the POP dietary groups than in the PPO groups. These results suggest that the absorption and metabolism of fat depend on the positional isomer of the fatty acid.