Feasibility of virtual surgical simulation in the head and neck region for soft tissue reconstruction using free flap: a comparison of preoperative and postoperative volume measurement.

In the head and neck region, preoperative evaluation of the free flap volume is challenging. The current study validated preoperative three-dimensional (3D) virtual surgical simulation for soft tissue reconstruction by assessing flap volume and evaluated fat and muscle volume changes at follow-up in 13 head and neck cancer patients undergoing anterolateral craniofacial resection. Patients received 3D virtual surgical simulation, and the volume of the planned defects was estimated by surgical simulation. Following en bloc resection of the tumor, the defect in the skull base was covered using a rectus abdominis myocutaneous flap. Following surgery, computed tomography scans were acquired at day 1 and at 6 and 12 months. Virtual planned defect was on average 227 ml (range, 154-315) and was 10% smaller than the actual flap volume in patients without skin involvement of the tumor. Between day 1 and 12 months post-surgery, the volume of fat and muscle tissue in the free flap dropped by 9% and 58%, respectively. Our results indicate that 3D virtual surgical simulation provides essential information in determining the accurate volume of the required free flap for surgical defect repair and may thus help improve surgical planning and functional and esthetic outcome.

Two proteins with gamma-carboxyglutamic acid in frog bone: isolation and comparative characterization.

Two gamma-carboxyglutamic acid-containing proteins were purified from neutral (pH 7.5) EDTA-extract of frog, Rana catesbiana, cortical bone by Sephadex G-75 gel filtration, DEAE-Sephadex A-25 chromatography and successive hydroxyapatite column chromatography. These two bone gamma-carboxyglutamic acid-containing proteins, termed osteocalcin, P-1 and P-2, had molecular weights of about 5100 and 4900, respectively, based on their amino-acid composition. Both species of osteocalcin have two gamma-carboxyglutamic acid residues, one disulfide bond, but there was no 4-hydroxyproline in either molecule. Each N-terminus of both proteins was acetylated and each C-terminal amino acid was lysine. The isoelectric points of P-1 and P-2 are 4.02 and 3.91, respectively, and their pI values shifted to more neutral pH in the presence of calcium ions. Equilibrium dialysis has indicated that each of these two proteins binds specifically 2 mol Ca2+, and nonspecifically more, 4-5 mol, Ca2+ in 0.02 M Tris-HCl/0.15 M NaCl (pH 7.4), at 4 degrees C. By the best-fitted calculation, P-1 had one high affinity Ca2+-binding site (Kd1 = 0.17 mM) and one lower affinity site (Kd2 = 0.29 mM), and P-2 contained one high affinity site (Kd1 = 0.154 mM) and one lower affinity site (Kd2 = 0.67 mM).

Effects of cadmium on in vitro and in vivo erythropoiesis: erythroid progenitor cells (CFU-E), iron, and erythropoietin in cadmium-induced iron deficiency anemia.

Effects of cadmium (Cd) on in vitro and in vivo erythropoiesis in rats were studied by methylcellulose colony assay. Cd suppressed the in vitro growth of late erythroid progenitors (CFU-E) in a dose-dependent fashion and did not lose its inhibitory potency with increasing doses of erythropoietin (EPO). In addition, in marrow suspension cultures, Cd did not significantly influence 59Fe incorporation into both the cells and heme, and the Cd dose-responsive inhibition curve of the number of living cells was similar to that of CFU-E. These results suggest that the suppression of CFU-E colony formation by Cd is not due to the blocking of either EPO action to stimulate the growth of CFU-E or the iron incorporation into the cells ahd heme, but due to its direct cytotoxic effect. The colony suppression by Cd could be prevented by adding metallothionein to the cultures. On the other hand, oral administration of Cd to animals (100 mg/liter in drinking water) induced an iron deficiency anemia characterized by microcytic hypochromic red cells, decreased plasma iron, and increased total iron binding capacity. Marrow CFU-E density steadily increased as plasma iron decreased due to Cd administration and reached a plateau after 50 days. Plasma EPO titers were also found to be elevated in such a Cd-induced anemia. Parenteral iron administration during the Cd drinking period could completely prevent the development of iron deficiency anemia and the increase of both CFU-E and plasma EPO. There was a hyperbolic correlation between CFU-E and plasma iron or transferrin saturation. These results demonstrate that oral CD administration produces bone marrow hyperplasia at the CFU-E level due to iron deficiency.

Elimination of Na+-dependent bile acid transporter from small intestine by ileum resection increases [correction of increase] colonic tumorigenesis in the rat fed deoxycholic acid.

Ileal Na+-dependent bile acid transporter (ISBT) constituting a gateway to enterohepatic circulation of bile acids occurs exclusively at the distal site of the small intestine. In the present study, we examined colonic tumorigenesis promoted by deoxycholic acid in relation to the expression of the ISBT. For this purpose, the small intestine of a Fischer-344 rat was resected a length of 20 cm above the ileo-cecal valve (ileal resection) or below the duodenum (jejunal resection). Then, rats were treated with an intraperitoneal injection of azoxymethane (15 mg/kg body wt.) once a week for 3 weeks and fed a 20% casein diet supplemented with 0.2% deoxycholate for 39 weeks. Northern blot analysis demonstrated that the ISBT mRNA was hardly detectable in ileum-resected rats. The excretion of fecal bile acids was 1.5-fold higher in the ileum-resected group than in the jejunum-resected group (P < 0.05). On the contrary, the serum bile acids concentration of ileal-resected rats was about one-half of that of jejunum-resected animals (P < 0.05). The tumor incidence and the total tumor number were significantly higher in the ileum-resected group than in the jejunum-resected one (P < 0.05). Interestingly, no tumor was found at the proximal colon in the jejunum-resected group while tumors developed frequently at the proximal site as well as mid and distal colon in the ileum-resected group. These observations demonstrate that malabsorption of bile acids owing to the lack of ISBT enhanced colon tumorigenesis.

Metal binding and metal-induced conformational change of frog bone gamma-carboxyglutamic acid-containing protein.

Ca2+ or Cd2+ binding and the conformational change induced by the metal binding in two frog bone Gla-proteins (BGP, termed BGP-1 and BGP-2) were studied by equilibrium dialysis and CD measurement. By CD measurement in the far-ultraviolet region, the alpha-helix content of both apoBGPs was found to be 8%. Binding of both Ca2+ and Cd2+ was accompanied with a change in the CD spectrum, and the alpha-helix content increased to 15 and 25% for BGP-1 and BGP-2, respectively. CD measurement in the near-ultraviolet region indicated that the environment of aromatic amino acid residues in the protein molecule was changed by metal binding. Equilibrium dialysis experiments indicated that each of these two protein binds specifically 2 mol of Ca2+, and nonspecifically an additional 3-4 mol of Ca2+ in 0.02 M Tris-HCl/0.15 M NaCl (pH 7.4), at 4 degrees C. According to the two separate binding sites model, BGP-1 has 1 high-affinity Ca2+ binding site (Kd1 = 0.17 mM) and 1 low-affinity site (Kd2 = 0.29 mM), and BGP-2 contains 1 high-affinity site (Kd1 = 0.14 mM) and 1 low-affinity site (Kd2 = 0.67 mM). In addition, 2 Cd2+ bound to a high-affinity binding site on BGP-1 with Kd1 of 10.4 microM, and 1 Cd2+ bound to a low-affinity binding site with Kd2 of 41.5 microM. On the other hand, BGP-2 had three classes of binding sites and 1 Cd2+ bound to each binding site with Kd1 = 3.6 microM, Kd2 = 16.3 microM, Kd3 = 51.7 microM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for an essential arginyl residue in bovine milk gamma-glutamyltransferase.

Treatment of bovine milk gamma-glutamyltransferase with 2,3-butanedione in borate buffer markedly inactivates its gamma-glutamyltransferase activity. Inactivation is prevented by a combination of the gamma-glutamyl donor and acceptor substrates, glutathione, and glycylglycine, but less effectively by only one of them. Serine plus borate of maleate provides no protection against the inactivation. Amino acid analysis of the enzyme treated with butanedione in the presence and absence of the protecting substrate combination indicates that complete inactivation correlates with the modification of a single arginyl residue per molecule. The residue modified is associated with the smaller subunit of the two equal subunits which comprise the enzyme. The butanedione-treated enzyme retains a hydrolytic activity, another but less significant catalytic function of the enzyme. The results indicate that the arginyl residue is involved in recognizing the anionic moiety of the acceptor and in binding it to the acceptor site located on the smaller subunit of the enzyme.

Variation of glutathione level and synthesis activity in chick liver due to selenium and vitamin E deficiencies.

Chicks were fed an amino acid mixture-based diet (basal diet) or one supplemented with selenium (Se, 0.2 micrograms/g as Na2SeO3) and/or vitamin E (100 micrograms/g as alpha-tocopherol). The group receiving the basal diet devoid of Se and vitamin E showed a tendency to grow slowly, but not significantly so, compared to the non-deficient control and manifested a symptom of exudative diathesis after the feeding period of 4 weeks. Supplementation of the basal diet with Se or vitamin E prevented the deficiency symptoms in the chicks. The hepatic GSH level and GSH synthesis activity were about three times as much in the Se- and vitamin E-deficient group as in the control. This was also the case for in vivo sulfur incorporation into hepatic GSH for 10 h post-injection with [35S]methionine. The increased level of GSH may partly compensate the hepatocytes for peroxidative damage.

The amino acid sequence of a Bowman-Birk type proteinase inhibitor from faba beans (Vicia faba L.).

The amino acid sequence of a Bowman-Birk type proteinase inhibitor (FBI) from seeds of faba bean (Vicia faba L.) was determined by analysis of peptide fragments generated by reduction and S-carboxymethylation of enzymatically modified inhibitors, which were obtained from native FBI by limited proteolysis with TPCK-trypsin or TLCK-chymotrypsin at pH 3.5. The established sequence showed that FBI is highly homologous with Vicia angustifolia inhibitor (VAI0 but lacks the portion corresponding to the C-terminal 9 amino acids of VAI. The trypsin reactive-site peptide bond in FBI was also indicated to be Lys(16)-Ser(17) and the chymotrypsin reactive-site peptide bond to be Tyr(42)-Ser(43) by limited proteolysis with TPCK-trypsin or TLCK-chymotrypsin and by sequence comparison with other Bowman-Birk type inhibitors.

Characterization, cDNA cloning, and functional expression of mouse ileal sodium-dependent bile acid transporter.

Mouse ileal sodium dependent bile acid transporter (ISBT) was characterized using isolated enterocytes. Only enterocytes from the most distal portion showed Na+-dependent [3H]taurocholate uptake. Northern blot analysis using a probe against mouse ISBT revealed the expression of mouse ISBT mRNA to be restricted to the distal ileum. The Km and Vmax for Na+-dependent [3H]taurocholate transport into isolated ileocytes were calculated as 27 microM and 360 pmol/mg protein/min, respectively. Uptake of [3H]taurocholate was inhibited by N-ethylmaleimide. We have cloned ISBT cDNA from mouse ileum. The cDNA included the entire open reading frame coding 348 amino acid protein with seven hydrophobic segments and two N-glycosylation sites. COS-7 cells transfected with the expression vector containing this cDNA expressed Na+-dependent [3H]taurocholate uptake activity with a Km of 34 microM.

Determination of nutritional efficiency of selenium contained in processed skipjack meat by comparison with selenite.

The nutritional efficiency of selenium (Se) contained in two kinds of processed fish meat was appraised. Rats were fed on a 20% casein diet deficient in Se (0.046 micrograms/g diet) for 2 weeks, and were then fed on the basal diet supplemented with 0.08 micrograms/g of Se as sodium selenite, boiled meat of skipjack or dried strip of skipjack for an additional 8 days. The Se-supplementation caused a significant increase of the Se concentration and the glutathione peroxidase activity in the rat liver. Although significant differences in hepatic Se levels were not observed among the rats fed on the Se-supplemented diets, the elevation of the hepatic enzyme activities of the rats fed on the skipjack-supplemented diets was only 45 to 53% that of the rats fed on the selenite-supplemented diet. Amounts of excretion of both fecal and urinary Se of the rats fed on the diets supplemented with the skipjacks were higher than those of the selenite-administered rats. These results indicate that the nutritional efficiency of the Se in the skipjack meat is about 50% that of selenite and that unknown factor(s) other than luminal absorption contribute to the low availability of the Se in the skipjack meat.

Protein-nutritive assessment of sake lees obtained by brewing from liquefied rice.

Sake lees obtained by brewing from liquefied rice were deprived of water and alcohol by lyophilization, and then examined for nutritional availability with the aid of proximate food analysis, amino acid analysis and animal experiment. Freeze-dried sake lees powder was comprised of 44.6% protein, 37.4% carbohydrate, 2.5% fat, 6.7% fiber, 1.8% ash and 7.2% moisture (alcohol < 0.1%), of which the nutritive value (amino acid score) was estimated as 89.6 when compared with the amino acid requirements for preschool children (FAO/WHO/UNU, 1985). Sake lees protein had been, however, appreciably improved in the limiting amino acid "lysine" relative to polished rice protein. As a result of an animal experiment, the rats fed a 50% sake lees powder diet proved to be equal in growth to those fed a 20% casein (control) diet, although the former diet had to be supplemented with vitamins and minerals, which were in shortage as compared to the control diet. On the other hand, the feeding of sake lees powder was effective in lowering the serum triacylglycerol concentration. Accordingly, sake lees powder can be assessed as a favorable candidate for not only protein-rich but also hypolipidemic provisions.

Effect of dietary proteins and/or their digestive products on intestinal taurocholate absorption.

[14C]Taurocholate was orally administered to rats together with a definite amount of either casein- or soy protein-based diet and its postprandial movement along the digestive tract was investigated. A difference was observed between both dietary groups in intraluminal transit as well as mucosal accumulation of [14C]taurocholate in the ileum; namely the soy protein intake led to a decrease in the bile acid incorporation into the ileal mucosa relative to the casein intake, although raising its intraluminal stay. In addition, the digestive products from these and other food proteins by pepsin-pancreatin digestion (peptides with molecular weights of more than 1,000) were examined for their inhibitory effects on in vitro absorption of taurocholate with ileal everted sacs. As the digestive product affinity for taurocholate increased, the rate of taurocholate absorption decreased. It thus seems likely that a food protein more abundant in hydrophobic peptides following intraluminal digestion adsorbs much more bile acids in the gut, thereby disturbing their intestinal absorption.

Antioxidative activity of barley hordein and its loss by deamidation.

Barley hordein was comparable to maize zein in antioxidation under a powder model system. Various deamidated "hordein" preparations were obtained and examined for their molecular-size distribution (by Sephacryl S-100 gel filtration), hydrophobicity (by fluorescence measurement using fluorescent probes) and antioxidative activity (by the ferric thiocyanate method). Deamidation caused fragmentation of the hordein molecule and simultaneously lowered its fatty acid-binding capacity rather than its surface hydrophobicity. Then, the antioxidative activity diminished with increasing deamidation. When the fatty acid-binding capacity was plotted against the antioxidative activity, a high correlation (r2 = 0.92) was observed between these two events.

Feeding soybean resistant protein to rats raises fecal bile acid excretion but counteracts a deoxycholate-caused decrease in colonic aberrant crypt foci.

A high-molecular-weight fraction after removal of water-soluble peptides from proteinase-treated soybean protein isolate (referred to as HMF) was examined for its effect on preneoplastic lesions in the rat colon. For this purpose, male Fisher-344 rats 7 wk old were divided into 8 groups (n = 5), of which 6 groups received 3 injections of azoxymethane (AOM, 15 mg/kg of body weight) for 3 wk once a week, while all were fed HMF or casein diets supplemented with or without deoxycholic acid (DCA) over a period of 4 wk. Two groups of AOM-treated rats were allowed free access to HMF or casein diets without supplemental DCA, respectively, while the others were pair-fed so as to be well matched in their food intake. There were no significant differences in growth parameters among the pair-fed groups. Feeding HMF diets raised fecal lipid and acidic steroid excretions to a greater extent than feeding casein diets, secondary bile acids being conspicuous among acidic steroids in the excreta irrespective of the presence or absence of DCA supplementation. As a result of observation for colonic aberrant crypt foci (ACF), the intake of HMF proved to reverse the reduction of ACF appearance by DCA. This result implies that secondary bile acids are caught and brought out by HMF, or rather its derivative "resistant protein," so as not to keep contact with colonic mucosae.

Mechanism and regulation of thiamine pyrophosphokinase from parsely leaf.

Thiamine pyrophosphokinase (EC 2.7.6.2) from parsely leaf showed an absolute requirement for divalent cation such as Mg2+, Mn2+ and Co2+. The activation effect varied with the species and concentrations of such cations. When Mn2+ or Co2+ was used as cofactor, maximal activation was found at a lower level than ATP concentration, whereas the activation by Mg2+ increased hyperbolically with the concentration. Studies of initial velocity and product inhibition led to conclude that the kinase reaction obeys a sequential ordered Bi Bi mechanism; i.e. the enzyme combines in turns with MgATP and thiamine, followed by release of TPP and AMP. The inhibition type revealed for inorganic pyrophosphate was competitive with respect to thiamine with Ki of approximately 2.8 mM. On the other hand, thiamine monophosphate exhibited noncompetitive inhibition with Ki of 0.2 mM. The plots of the reaction rate against MgATP concentrations gave a sigmoidal curve. Addition of either AMP or GMP resulted in restoration of a depressed activity at low concentration of MgATP. The "allosteric" inhibition was also relieved by the addition of an excess amount of magnesium ions. These findings suggest that transphosphorylation is regulated by subcellular concentrations of metal ions relative to ATP or of the products involved in the thiamine biosynthesis.

Enzymic formation of thiamine pyrophosphate in plants.

Evidence was presented by paper chromatographic analysis on the occurrence of an enzyme capable of catalyzing a pyrophosphate transfer from ATP to thiamine in green leaves of various plants. The exclusive localization of the enzyme activity in the 105,000 X g supernatant (in a soluble form) was demonstrated by differential centrifugation of a cell homogentae in 0.25 M sucrose. The enzyme was purified by column chromatography with DEAE-cellulose and by gel filtration with Sephadex G-150. The partially pruified preparation, while contaminated with detectable activity of acid phosphatase, lost the ability of utilizing thiamine monophosphate as the substrate in place of thiamine. These findings lead to the conclusion that thiamine pyrophosphate is formed in green leaves of plants through a direct pyrophosphorylation of thiamine in the presence of ATP and Mg.

Purification and properties of thiamine pyrophosphokinase from parsely leaf.

Thiamine pyrophosphokinase was purified about 8,000-fold from extracts of parsely leaves. The enzyme, as prepared, was homogenous on polyacrylamide gel electrophoresis. The molecular weight of the enzyme, estimated by gel filtration with Sephadex G-150, was approximately 30,000. In 0.05 M Tris-HCl, the enzymic activity showed a pH optimum over a range of 8 to 9. A least squares analyses of Lineweaver-Burk and Hofstee plots gave Km values of 0.8mM and 0.15mum for ATP and thiamine, respectively. Thiamine homologues and analogues so far tested, except for cetyl thiamine, were all inactive as substrates. The enzyme was specific for ATP and Mg++, although to a lesser extent a combination with other ribonucleoside triphosphates or divalent cations could replace them. SH reagents, such as PCMB, NEM and iodoacetamide, were potent inhibitors of the enzyme. The inhibition was prevented by the addition of dithiothreitol. Inorganic pyrophosphate exhibited striking inhibition. TMP could not replace thiamine as the substrate, whereas it inhibited the TPP formation from thiamine. These findings are consistent with the views that TMP is not directly converted to TPP but after being dephosphorylated by the action of a monoesterase, thiamine is pyrophosphorylated with ATP by thiamine pyrophosphokinase (EC 2.7.6.2) to form TPP and thus give a clear evidence regarding the mechanism of TPP formation in plant tissues.

Effect of feeding peptic digest of soy protein isolate on rat serum cholesterol.

Growing rats were fed ad libitum soy protein isolate (SPI) or its peptic (SPI-P) or tryptic digest (SPI-T) for a month and their sera were examined for cholesterol and triglyceride levels and enzyme activities such as cholinesterase, glutamate-pyruvate transaminase (GPT) and alkaline phosphatase. The rats fed SPI-P or SPI-T were inferior in growth to those fed SPI. Similarly, the serum glyceride level was lower in the SPI-P and SPI-T groups than in the SPI group. On the other hand, a significant difference was found in the serum cholesterol level between the SPI-P and SPI or SPI-T groups but not between the SPI and SPI-T groups. A similar tendency was observed for serum GPT and alkaline phosphatase activities, although there were no significant differences among dietary groups in small intestinal enzyme activities. As for the atherogenic index being a risk factor inducing atherosclerosis, the order of its value was SPI-P less than SPI less than SPI-T.

Preventive effect of soybean resistant proteins against experimental tumorigenesis in rat colon.

The insoluble 'high-molecular-weight' fraction (HMF) centrifugally separable after digestion of soy protein isolate with a microbial protease of the exo-type, of which about a quarter is regarded as an indigestible 'resistant protein,' was examined for its preventive effect against colonic tumorigenesis in a model system with male F-344 rats. The rats were intraperitoneally injected with azoxymethane (15 mg/kg BW) once a week for 3 wk and were fed a 20.6% HMF diet (+0.4% DL-Met) or 14.7% casein diet (+0.3% DL-Met) supplemented with 0.2% sodium deoxycholate (DCA) or without supplementation. Twelve wk later, 5 rats of each group were inspected for formation of tumors but no tumors were visible to the naked eye. The DCA-fed casein group was conspicuous for a low count of aberrant crypt foci. At 39 wk, 6 rats of the DCA-fed casein group (n = 10) and 3 rats of the DCA-fed HMF group (n = 9) had a total of 18 tumors with a major axis of 4.0 +/- 0.4 mm and 3 tumors with an axis of 2.0 +/- 0.1 mm, respectively, in contrast to only a single tumor for the DCA-unfed casein group (nil for the DCA-unfed HMF group). The difference in tumor number and size was considered significant between these DCA-fed casein and HMF groups; that is to say, HMF feeding retarded tumor development despite the frequent occurrence of pre-neoplastic lesions. In addition, fecal bile acid excretion was much more elevated by HMF feeding than by casein feeding. It can be assumed from these observations that the antitumorigenicity of HMF is due to the inhibitory effect of soybean resistant proteins on reabsorption as well as the mucosal contact of bile acids in the intestine.

In vivo action of alpha-amylase inhibitor from cranberry bean (Phaseolus vulgaris) in rat small intestine.

An alpha-amylase inhibitor prepared from cranberry bean (Phaseolus vulgaris) was examined for its in vivo action on pancreatic alpha-amylase in rat small intestine. For this purpose, postprandial changes not only in intraluminal alpha-amylase activity but also in plasma glucose and insulin concentrations were measured at various times after administration of 2 g of 10% polyethylene glycol-containing experimental diets with and without the inhibitor. No considerable increase was observed in the levels of intraluminal alpha-amylase activity, blood sugar, and plasma insulin in the animals given the inhibitor at a dose of 10 mg each. These results suggest that the purified preparation from cranberry bean serves in fact as a potent inhibitor of rat pancreatic alpha-amylase.