Transgalactosylation catalyzed by alpha-galactosidase from Candida guilliermondii H-404

The thermostable alpha-galactosidase from Candida guilliermondii H-404 synthesized self-transfer products in the absence of a suitable acceptor. The main self-transfer product, using melibiose as a donor substrate, was O-alpha-D-galactosyl-(1,6)-O-alpha-D-galactosyl-(1,6)-D-glucose. This enzyme had a wide acceptor specificity. D-Glucose, D-galactose, maltose, maltitol, and 1,4-butandiol were the most effective acceptors in the transgalactosylation catalyzed by this enzyme. The enzyme could also transfer alpha-galactosyl residues to pentoses (L-arabinose, D-xylose, and D-ribose) and methyl pentoses (D-fucose and L-rhamnose). The main transfer products to lactose, maltose, and sucrose as acceptors were identified as O-alpha-D-galactosyl-(1,6)-O-beta-D-galactosyl-(1,4)-D-glucose, O-alpha-D-galactosyl-(1,6)-O-alpha-D-glucosyl-(1,4)-D-glucose, and O-alpha-D-galactosyl-(1,6)-O-alpha-D-glucosyl-(1,2)-beta-D-fructoside (raffinose), respectively.

Glibenclamide, a blocker of ATP-sensitive potassium channels, abolishes infarct size limitation by preconditioning in rabbits anesthetized with xylazine/pentobarbital but not with pentobarbital alone

The role of ATP-sensitive potassium channels (KATP) in the mechanism of ischemic preconditioning (PC) is controversial, partly because descriptions of inhibition of PC by KATP blockers in the literature are inconsistent. We sought a reason for the discrepant findings regarding the effects of glibenclamide (Glib), a specific blocker of KATP, in preventing the reduction of infarct size (IS) induced by PC. The effect of Glib pretreatment (0.3 mg/kg i.v.) on PC was examined in three conditions: (a) when PC was performed with 3- and 5-min ischemia (i.e., potency of PC differs), (b) when rabbits were pretreated with prazosin and metoprolol (0.15 mg/kg i.v. each) to reduce myocardial O2 consumption, and (c) when xylazine was added to pentobarbital anesthesia. In rabbits under pentobarbital anesthesia, the left coronary artery was occluded for 30 min and then reperfused. The area at risk (AAR) and IS were determined 72 h after reperfusion in the first series of experiments and 3 h after reperfusion in the second and third series. IS as a percentage of AAR (%IS/AR) were 31.7 +/- 2.8 and 19.6 +/- 2.5% (SEM) after PC with 3- and 5-min ischemia, respectively, values significantly smaller than %IS/AR in the untreated control group (49.2 +/- 3.3%). The limitation of IS observed with 3- or 5-min PC was not prevented by Glib. Glib also failed to block %IS/AR reduction by PC, even when rate-pressure product (RPP) was reduced to approximately 65% by prazosin/metoprolol (Praz/Met) pretreatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Midkine is present in the early stage of cerebral infarct

Expression of midkine (MK), a growth factor with neurotrophic activities, was examined immunohistochemically in experimental cerebral infarct of rats. From postoperative day 1 to day 7 after the onset of infarct, anti-MK immunoreactivity was observed in the surrounding ischemic zone of the infarct but not in the necrotic lesion. The immunoreactive material was identified to be MK by Western blotting. On day 14, anti-MK immunoreactivity became negative. Absence of MK in the normal brain was verified both by immunohistochemical staining and Western blotting. The induced expression of MK is an early event: increased expression of glial fibrillary acidic protein (GFAP), a marker of astrocytes, started on day 4 and continued to day 14. These findings suggest that MK is produced around the site of nerve damage and plays a role as a reparative neurotrophic factor during the early phase of cerebral infarct.

Histopathological study on the effect of octreotide

The present investigation was performed to clarify the mechanism of action of octreotide. On a quantitative study by electron microscopy showed that lysosomes were markedly increased in the patients receiving octreotide. Growth hormone (GH) was shown to be in the secretory granules by the postembedding immunogold technique, but no GH immunostaining was noted of the lysosomes. The present investigation suggests that retention of secretory granules and subsequent lysosomal increase are the mechanism of GH-lowering effect of octreotide.

[A case of mixed connective tissue disease associated with gastric cancer and cancer of the uterine cervix]

We report here a very rare case of MCTD complicating double cancer. A 43-year-old woman with suspected MCTD was admitted because of high fever and lymphadenopathy. The laboratory findings indicated high titers of speckled ANA, anti-RNP, DNA and Scl-70, but anti-Sm. SS-A and SS-B was not detected. Chest CT and Spirogram revealed lung fibrosis, restrictive ventilatory impairment, and decreased diffusion capacity. Biopsy specimen by gastric fiberscope s screening indicated II c advanced type of poorly differentiated adenocarcinoma. After subtotal gastrectomy, she had high fever, pleuritis, leukopenia, butterfly erythema and hypoxemia, which were improved by 30 mg/day of oral prednisolone. One year after from the last operation, she had contact bleeding, and squamous cell carcinoma of the uterine cervix was diagnosed. She had Raynaud's phenomenon 6 months after from hysterectomy.

[A surgical treatment of type A aortic dissection associated with annuloaortic ectasia using hypothermic circulatory arrest with retrograde cerebral perfusion]

A 30-year-old man was admitted to the hospital because of type A aortic dissection associated with annuloaortic ectasia (AAE). A magnetic resonance image (MRI), computed tomography of the aorta demonstrated aortic enlargement with dissection, but revealed no evidence of dissection of the aortic arch. A transesophageal echocardiography demonstrated dissection of the aortic arch. A graft replacement of the total aortic root were performed using hypothermic circulatory arrest with retrograde cerebral perfusion and open distal anastomosis. We reconstructed coronary ostiums with carrel patch, and discontinued the operation without major bleeding. No neurological deficit was found postoperatively.

Role of the carbohydrate moiety of a glucoamylase from Aspergillus awamori var. kawachi in the digestion of raw starch

The digestion of raw starch by a glucoamylase (GA MU-H) from a mutant strain of Aspergillus awamori var. kawachi was closely correlated with mannoside chains O-linked to the Gp-I region (A470-V514), but not sugar chains N-linked to catalytic GAI' domain of GA MU-H. The partial replacement of mannose residues by glucose residues led to a significant decrease raw starch digestion. By the substitution of D2O for H2O in the reaction mixture, the raw starch digestion of GA MU-H decreased to 80% of that at 30 degrees C, although the rate of hydrolysis of soluble starch by and the ability to bind beta-cyclodextrin of GA MU-H were unchanged. Glycerol, known as an antichaotropic reagent, decreased the raw starch digestion of GA MU-H significantly. However, it did not have any effect on the enzymatic activity for soluble starch when soluble starch was the substrate. The efficient digestion of raw starch with raw starch-digesting glucoamylase needed the mannoside chains O-linked to the Gp-I region, which were suggested to contribute to digestion of raw starch through the interaction with water.

Glomerulonephritis associated with MRSA infection: a possible role of bacterial superantigen

We report 10 cases of glomerulonephritis following methicillin-resistant Staphylococcus aureus (MRSA) infection. The clinical features of this syndrome were an abrupt or insidious onset of rapidly progressive glomerulonephritis (RPGN) with nephrotic syndrome and occasionally purpura, following MRSA infection. The renal histologic findings showed a variety of types of proliferative glomerulonephritis with varying degrees of crescent formation; immunofluorescence revealed of glomerular deposition of IgA, IgG, and C3. Laboratory findings showed polyclonal increases of serum IgA and IgG, with high levels of circulating immune complexes (ICs). Increased numbers of DR+CD4+, and DR+CD8+T cells were observed in the peripheral circulation, with a high frequency of T cell receptor (TCR) V beta + cells. MRSA produced enterotoxins C and A and toxic shock syndrome toxin (TSST)-1, all of which are known to act as superantigens. From the above observations, we speculate that post-MRSA glomerulonephritis may be induced by superantigens causing production of high levels of cytokines, and polyclonal activation of IgG and IgA. The formation of ICs containing IgA and IgG in the circulation result in development of glomerulonephritis and vasculitis. Accordingly, microbial superantigens may play an important role in the pathogenesis of this unique syndrome of nephritis and vasculitis.

Receptor-mediated regulation of differentiation and proliferation of hepatocytes by synthetic polymer model of asialoglycoprotein

Morphology and responses of hepatocytes are investigated using an artificial asialoglycoprotein model polymer--lactose-carrying polystyrene (PVLA) as a culture substratum, especially in focusing on the effect of the surface density of the PVLA substratum. The surface density of PVLA on polystyrene dishes was determined using fluorescein-labeled PVLA as a probe under a fluorescence laser microscope. PVLA-coated surfaces were observed by scanning electron microscope and atomic force microscopies under air and water, which showed that PVLA molecules were adsorbed patchily on low density surfaces and uniformly concentrated all over the dish on high density surfaces. It is suggested from the requirement of the Ca2+ ion, inhibition of galactosyl substances, and localization of receptors that the adhesion of hepatocytes to both low and high PVLA-density surfaces is mediated by galactose-specific interactions between PVLA and asialoglycoprotein receptors. At low PVLA densities (0.07 micrograms cm-2), the hepatocytes were flat and expressed high levels of 3H-thymidine uptake and low levels of bile acid secretion. Contrastingly, at high PVLA densities (1.08 micrograms cm-2), they were round and expressed a low level of 3H-thymidine uptake and a high level of bile acid secretion. The shapes, proliferation, and differentiation of hepatocytes could be regulated by varying the densities of PVLA adsorbed to polystyrene dishes. We assume that there are two recognition mechanisms operating between PVLA and hepatocytes: (1) adhesion through highly concentrated or clustered galactose-specific interaction; and (2) responses in shape, proliferation, and differentiation by PVLA-coating densities.

Regional mapping of two subunits of transcription factor E4TF1 to human chromosome

Genes of human transcription factor E4TF1 subunits, E4TF1a and E4TF1b, were mapped to region q21 of human chromosome 21 and to region q11.21 of human chromosome 7, respectively, by using a fluorescence in situ hybridization method.

Anti-lipid A monoclonal antibodies and anti-LPS antiserum effects on limulus activity of LPS

Anti-lipid A monoclonal antibodies (A78S1 and A523) and anti-LPS antiserum can decrease the mortality due to endotoxic shock in the newborn rat. However, in vitro LPS detoxification of anti-lipid A monoclonal antibodies is not known. Thus, we studied in vivo effects of A78S1 (IgG), A523 (IgM), and anti-LPS antiserum on Limulus activity. Anti-LPS antiserum decreased Limulus activity of S. enteritidis, E. coli and S. typhosa LPS. However, neither A78S1 nor A523 decreased the Limulus activity of E. coli and S. typhosa LPS. A78S1 or A523 incubation with S. enteritidis LPS at different doses (0.1 to 100 ng/ml) did not alter the Limulus activity. Perchloric acid treatment after LPS incubation with A78S1 or A523 significantly decreased Limulus activity. Therefore, antilipid A monoclonal antibodies (A78S1 and A523) can bind LPS, but do not decrease Limulus activity.

Analysis of the raw starch-binding domain by mutation of a glucoamylase from Aspergillus awamori var. kawachi expressed in Saccharomyces cerevisiae

Carboxy-terminal deletions were introduced into the raw starch-binding domain (A-515 to R-615) encoded by the gene for glucoamylase I (GAI) from Aspergillus awamori var. kawachi. Genes coding for proteins designated GA596 (A-1 to E-596), GA570 (A-1 to A-570), and GA559 (A-1 to N-559) were constructed and resulted in truncated proteins. All of the mutant genes were expressed heterologously in Saccharomyces cerevisiae. GA596 adsorbed to raw starch and digested it. GA570 and GA559 did not adsorb to raw starch or to an alpha-cyclodextrin-Sepharose CL-4B gel under our experimental conditions. However, GA570 was able to digest raw starch, and the digestion of raw starch by GA570 was inhibited by beta-cyclodextrin. Residue Trp-562 of GAI, which was suggested previously to contribute to formation of an inclusion complex with raw starch, was replaced by Leu (GAW562L), Phe (GAW562F), and Gly (GAW562G). GAW562L and GAW562F adsorbed to raw starch and an alpha-cyclodextrin gel, but GAW562G did not. Although GAW562L digested raw starch to the same extent as wild-type GAI (designated GAY), GAW562F and GAW562G exhibited less ability to digest raw starch. On the basis of our results, it appears that the sequence around Trp-562, PL(W-562)YVTVTLPA, is the minimal sequence necessary for digestion of raw starch and that hydrophobic residue Trp-562 contributes to formation of an inclusion complex. The sequence near Trp-589, which has abundant hydrogen bond-forming residues and the charged amino acid residues needed for stable adsorption to raw starch, probably assists in the formation of the inclusion complex.

Effects of nitroglycerin on diameter and pulsation amplitude of subendocardial arterioles in beating porcine heart

We examined the effect of nitroglycerin (NTG) on the diameter and diastolic-to-systolic pulsation amplitude of large (ID > 100 microns) and small (ID < 100 microns) subendocardial arterioles with their segmental responses. In 10 open-chest, anesthetized pigs, subendocardial arterioles of beating hearts (n = 18) were videorecorded using a needle-probe videomicroscope. Subendocardial arteriolar diameter was determined before and 1-2 min after NTG administration (25 micrograms/kg i.v.). In an additional experiment using three pigs, we monitored the transient response of subendocardial small arterioles (n = 5) from the time before NTG administration until 3 min after NTG. NTG dilated large subendocardial arterioles by 13 +/- 4% (means +/- SD, n = 10, P < 0.001) at about 1.5 min after NTG, but not small subendocardial arterioles (2 +/- 2%, n = 8, not significant). However, the small arterioles responded transiently to NTG in an earlier phase, especially to a higher dose. The percent diameter change of large subendocardial arterioles between diastole and systole at 1.5 min after NTG administration was 32 +/- 4%, which was larger than that under control conditions (19 +/- 8%, P < 0.05). The pulsation amplitude of small subendocardial arterioles at this time was almost unchanged by NTG (16 +/- 8 vs. 17 +/- 6%, NS) but increased transiently in an earlier phase. In conclusion, NTG dilated large subendocardial arterioles on the plateau phase of its impulse (intravenously) response (approximately 1.5 min after NTG).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac contraction and intramyocardial venous pressure generation in the anaesthetized dog

1. Two hypotheses relating to the influence of contraction of the heart on coronary venous pressure (Pv) were tested. The first assumes a direct transmission of left ventricular pressure (PLV). According to the alternative hypothesis the Pv is caused by cyclical changes in the elastance of the surrounding tissue. 2. A small epicardial vein was cannulated retrogradely in eight open-chest dogs deeply anaesthetized with fentanyl. The duration of diastoles was varied after induction of a heart block with formaldehyde. Coronary arterial inflow and perfusion pressure were controlled by a perfusion system connected to the left main coronary artery by a Gregg cannula. Stopped-flow Pv was studied with intrinsic coronary tone (IT) and after maximal dilatation with adenosine. 3. The Pv pulse in the first contraction after a long diastole was not significantly correlated to the PLV pulse, with a slope of 0.5, in any dog, either with IT or during adenosine treatment. Comparing the first contraction after the long diastole with the last beat before, systolic Pv pulse decreased significantly in seven out of eight dogs, but systolic PLV pulse increased in five dogs and was unaltered in three dogs in both conditions. In contrast, end-diastolic Pv was significantly correlated to the systolic Pv in each individual animal under either condition. 4. The results indicate that pressure generation in the small coronary veins can be explained on the basis of the time-varying elastance hypothesis and that a direct transmission of PLV to Pv is absent.

A comparative magnetic resonance imaging study of the corpus callosum in neurologically normal children and children with spastic diplegia

To determine the extent of brain damage in children with spastic diplegia, we analyzed the true midsagittal magnetic resonance imaging findings for the corpus callosum in 43 children with spastic diplegia and in 69 neurologically normal children. In the normal children, the thicknesses of the genu, midbody, splenium and the entire corpus callosum were found to increase with age, while the ratios of the thickness of the splenium and of the midbody to the length were constant, regardless of age. Both ratios were significantly reduced in diplegic children and the ratio for the splenium was highly correlated with the extent of motor impairment. Assessment of the morphometric changes in the corpus callosum using magnetic resonance imaging may contribute to the determination of the extent of brain damage in diplegic children.

Morphological changes of human mandibular bone during fetal periods

Standardized photographs (lateral and basal view) of fetal mandibles (n = 80) were taken. Outline segments (from gnathion to condylion, on the coronoid process and from infradentale to gnathion in lateral view; and on the inferior margin in basal view) were analyzed into sine curves, according to Fourier series. Using the calculated Fourier coefficients, we statistically examined how mandibular shape changed with fetal growth. Materials were classified into four groups on the basis of the body length (BL): 100 < or = BL < 200 mm (BL1, n = 20); 200 < or = BL < 300 mm (BL2, n = 20); 300 < or = BL < 400 mm (BL3, n = 20); and 400 < or = BL < or = 500 mm (BL, 4 = 20). Statistical analyses were all done on these stature groups. On the outline from gnathion to condylion, the constant and the first term phase showed statistically greater values in BL4 than in the other groups, as assessed by t-test. The first term phase for the coronoid process significantly decreased with increments in stature in the canonical disciminant analysis. On the outline from infradentale to gnathion, although the cumulative contributions of the first two terms were constant (about 85%) in all four groups, the relative contributions with growing stature decreased in the first term and increased in the second term. The mean of the phase in the first term indicated slightly more than -90 degrees in BL1, and was less than -90 degrees in BL2 to BL4. The averages of the second term phases presented little change from BL1 to BL3, and were close to -100 degrees. From the canonical discriminant analysis, the constant was great and the first term amplitude was small in BL1 and BL4, and the constant was small and the first term amplitude was great in BL2 and BL3. Also, the second term amplitude in BL4 indicated a significantly bigger volume than in BL3. The constant for the inferior margin manifested statistically significant increments in BL2 to BL4, as assessed by t-test. We interpret the results as follows: 1. On the outline from gnathion to condylion, anteroinferior shift occurs in BL4, resulting in an acute gonial angle. The change of angle during the prenatal period precedes the postnatal findings that bring about a progressive decrease in the gonial angle. 2. The tip of the coronoid process indicates a forward shift with increasing fetal body stature.(ABSTRACT TRUNCATED AT 400 WORDS)

Imaging features of maxillary osteoblastoma and its malignant transformation

We report two cases of osteoblastoma, one of them an unusual case in a 32-year-old woman in whom a maxillary tumor was confidently diagnosed as an osteoblastoma at the time of primary excision and subsequently transformed into an osteosarcoma 7 years after the onset of clinical symptoms. The other patient developed osteosarcoma arising in the maxilla, which was diagnosed 3 years after the primary excision and is very suggestive of malignant transformation in osteoblastoma. We present the radiological features, including computed tomographic and magnetic resonance imaging studies, of this unusual event of transformed tumor and compare imaging features of benign and dedifferentiated counterparts of this rare tumor complex.