Phase I/II study of adding intraperitoneal paclitaxel in patients with pancreatic cancer and peritoneal metastasis

BACKGROUND

Intraperitoneal chemotherapy using paclitaxel is considered an experimental approach for treating peritoneal carcinomatosis. This study aimed to determine the recommended dose, and to evaluate the clinical efficacy and safety, of the combination of intravenous gemcitabine, intravenous nab-paclitaxel and intraperitoneal paclitaxel in patients with pancreatic cancer and peritoneal metastasis.

METHODS

The frequencies of dose-limiting toxicities were evaluated, and the recommended dose was determined in phase I. The primary endpoint of the phase II analysis was overall survival rate at 1 year. Secondary endpoints were antitumour effects, symptom-relieving effects, safety and overall survival.

RESULTS

The recommended doses of intravenous gemcitabine, intravenous nab-paclitaxel and intraperitoneal paclitaxel were 800, 75 and 20 mg/m² respectively. Among 46 patients enrolled in phase II, the median time to treatment failure was 6·0 (range 0-22·6) months. The response and disease control rates were 21 of 43 and 41 of 43 respectively. Ascites disappeared in 12 of 30 patients, and cytology became negative in 18 of 46. The median survival time was 14·5 months, and the 1-year overall survival rate was 61 per cent. Conversion surgery was performed in eight of 46 patients, and those who underwent resection survived significantly longer than those who were not treated surgically (median survival not reached versus 12·4 months). Grade 3-4 haematological toxicities developed in 35 of 46 patients, whereas non-haematological adverse events occurred in seven patients.

CONCLUSION

Adding intraperitoneal paclitaxel had clinical efficacy with acceptable tolerability.

First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph

The masses of ^{246}Es, ^{251}Fm, and the transfermium nuclei ^{249-252}Md and ^{254}No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N=152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of ^{246}Es and ^{249,250,252}Md were measured for the first time. Using the masses of ^{249,250}Md as anchor points for α decay chains, the masses of heavier nuclei, up to ^{261}Bh and ^{266}Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ_{2n} derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N=152 neutron shell closure for Md and Lr.

Nuclear chemistry. Synthesis and detection of a seaborgium carbonyl complex

Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power of trends in the periodic table. So far, in gas-phase chemical reactions, simple inorganic compounds with the transactinoide in its highest oxidation state have been synthesized. Single-atom production rates, short half-lives, and harsh experimental conditions limited the number of experimentally accessible compounds. We applied a gas-phase carbonylation technique previously tested on short-lived molybdenum (Mo) and tungsten (W) isotopes to the preparation of a carbonyl complex of seaborgium, the 106th element. The volatile seaborgium complex showed the same volatility and reactivity with a silicon dioxide surface as those of the hexacarbonyl complexes of the lighter homologs Mo and W. Comparison of the product's adsorption enthalpy with theoretical predictions and data for the lighter congeners supported a Sg(CO)6 formulation.

Cloning of two isoforms of soluble acid invertase of Japanese pear and their expression during fruit development

Soluble acid invertase (S-AIV; EC 3.2.1.26) in Japanese pear fruit has an important role in accumulating hexoses during fruit enlargement and regulates the sucrose-to-hexose ratio in the vacuole. Full-length cDNA of PsS-AIV1 and PsS-AIV2 isoforms were cloned from Japanese pear fruit and their amino acid sequences share 40% identity; PsS-AIV1 was confirmed to code S-AIV isozyme purified previously. The roles of PsS-AIV1 and PsS-AIV2 genes throughout fruit development and in sugar composition were investigated by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using specific primers of their transcripts. PsS-AIV1 transcript had a maximum level at 34 days after full bloom (DAFB) and decreased rapidly during fruit development; PsS-AIV2 transcript increased gradually during fruit growth from 34 DAFB, had its maximum level at 79 DAFB and remained high until 107 DAFB at active fruit enlargement. The activity of S-AIV was highest at 34 DAFB, decreased during fruit growth until 66 DAFB, remained almost the same during early fruit enlargement until 79 DAFB and then decreased again. Soluble sugars fructose and glucose began accumulating predominantly during fruit enlargement from 66 DAFB; sucrose began increasing rapidly during fruit maturation from 121 DAFB. High expression of PsS-AIV1 transcript and high enzyme activity in the young fruit stage seems to have an important role in supplying a lot of substrate for energy needed for cell division and growth by hydrolyzing sucrose to hexoses. Increasing PsS-AIV2 expression during fruit enlargement may lead to rapid cell expansion through increased osmotic pressure by accumulation of a large amount of hexose in the vacuole.

An engineered sorbitol cycle alters sugar composition, not growth, in transformed tobacco

Many efforts have been made to engineer stress tolerance by accumulating polyols. Transformants that accumulate polyols often show growth inhibition, because polyols are synthesized as a dead-end product in plants that do not naturally accumulate polyols. Here, we show a novel strategy in which a sorbitol cycle was engineered by introducing apple cDNA encoding NAD-dependent sorbitol dehydrogenase (SDH) in addition to sorbitol-6-phosphate dehydrogenase (S6PDH). Tobacco plants transformed only with S6PDH showed growth inhibition, and very few transformants were obtained. In contrast, many transgenic plants with both S6PDH and SDH were easily obtained, and their growth was normal despite their accumulation of sorbitol. Interestingly, the engineered sorbitol cycle enhanced the accumulation of sucrose instead of fructose that was expected to be increased. Sucrose, rather than fructose, was also increased in the immature fruit of tomato plants transformed with an antisense fructokinase gene in which the phosphorylation of fructose was inhibited. A common phenomenon was observed in the metabolic engineering of two different pathways, showing the presence of homeostatic regulation of fructose levels.

Fruit-specific V-ATPase suppression in antisense-transgenic tomato reduces fruit growth and seed formation

The vacuole is a large, multifunctional organelle related to the processes of cell expansion, solute accumulation, regulation of cytoplasmic ion concentrations, pH homeostasis and osmoregulation, which are directly or indirectly achieved by vacuolar H+-pumps: vacuolar H+-ATPase (V-ATPase; EC 3.6.1.3) and vacuolar H+-pyrophosphatase (V-PPase; EC 3.6.1.1). In this study, we produced antisense-transgenic tomatoes (Lycopersicon esculentum L.) of the V-ATPase A subunit, which is under the control of the fruit-specific 2A11 promoter. One beta-glucuronidase (GUS)-transgenic line (GUS control) and seven A subunit antisense-transgenic lines were obtained. The amount of V-ATPase A subunit mRNA in fruit decreased in all antisense-transgenic lines, but in leaves showed no difference compared with the GUS control line and the nontransformant, suggesting that suppression of the V-ATPase A subunit by a 2A11 promoter is limited to fruit. The antisense-transgenic plants had smaller fruits compared with the GUS control line and the nontransformant. Surprisingly, fruits from the antisense-transgenic plants, except the fruit that still had relatively high expression of A subunit mRNA, had few seeds. Sucrose concentration in fruits from the antisense-transgenic plants increased, but glucose and fructose concentrations did not change. These results show the importance of V-ATPase, not only in fruit growth, but also in seed formation and in sugar composition of tomato fruit.

Molecular evidence of sorbitol dehydrogenase in tomato, a non-Rosaceae plant

The enzyme NAD-dependent sorbitol dehydrogenase (SDH) is well characterized in the Rosaceae family of fruit trees, which synthesizes sorbitol as a translocatable photosynthate. Expressed sequence tags of SDH-like sequences have also been generated from various non-Rosaceae species that do not synthesize sorbitol as a primary photosynthetic product, but the physiological roles of the encoded proteins in non-Rosaceae plants are unknown. Therefore, we isolated an SDH-like cDNA (SDL) from tomato (Lycopersicon esculentum Mill.). Genomic Southern blot analysis suggested that SDL exists in the tomato genome as a single-copy gene. Northern blot analysis showed that SDL is ubiquitously expressed in tomato plants. Recombinant SDL protein was produced and purified for enzymatic characterization. SDL catalyzed the interconversion of sorbitol and fructose with NAD (H). SDL showed highest activity for sorbitol among the several substrates tested. SDL showed no activity with NADP+. Thus, SDL was identified as a SDH, although the Km values and substrate specificity of SDL were significantly different from those of SDH purified from the Japanese pear (Pyrus pyrifolia), a Rosaceae fruit tree. In addition, tomato was transformed with antisense SDL to evaluate the contribution of SDL to SDH activity in tomato. The transformation decreased SDH activity to approximately 50% on average. Taken together, these results provide molecular evidence of SDH in tomato, and SDL was renamed LeSDH.

Gypsy embryo specifies ovule curvature by regulating ovule/integument development in rice

The embryo position in a seed is stable in most plant species, indicating the existence of a strict regulatory mechanism that specifies the embryo position in the seed. To elucidate this mechanism, we analyzed the gypsy embryo (gym) mutant of rice, in which the position of the mature embryo in the seed is altered at a low frequency. Analyses of early embryogenesis and ovule development showed that the ectopic embryo was derived from an ill-positioned egg cell, which resulted from the incomplete curvature of the ovule. Although the development of both the inner and outer integuments was impaired, the ovule curvature was associated closely with the extent of inner integument growth. Therefore, inner integument development controls ovule curvature in rice. The expression patterns of OSH1 and OsMADS13 indicated that, in gym, a small number of indeterminate cells are maintained on the style side of the ovule and then in the integument primordium at a low frequency. The prolonged survival of these indeterminate cells disturbs normal integument development. The gym fon2 double mutant suggests that GYM and FON2 are involved redundantly in floral meristem determinacy. Possible functions of the GYM gene and the ovule developmental mechanism are discussed.

Isolation, characterization, and cloning of {alpha}-L-Arabinofuranosidase expressed during fruit ripening of Japanese pear

alpha-L-Arabinofuranosidase (alpha-L-arafase) was purified from fruit of Japanese pear (Pyrus pyrifolia). The enzyme solubilized from the cell wall by NaCl and Triton X-100 had the homogeneity of a single 62-kD polypeptide on SDS-PAGE after purification through the steps of hydroxyapatite, anion-exchange chromatography, and size-exclusion chromatography. A related cDNA clone was isolated (PpARF2). The transcript and related protein were detected solely in the ripening fruit corresponding to the increase of alpha-L-arafase activity. Transcripts of PpARF2 were not detected in buds, leaves, roots, or shoots of the Japanese pear. The deduced amino acid sequences of PpARF2 had low identity with those of other plants or bacteria. This alpha-L-arafase belonged to glycoside hydrolase family 3, which includes some beta-xylosidases. The purified enzyme hydrolyzed mainly p-nitrophenyl alpha-L-arabinofuranoside and also reacted bifunctionally with p-nitrophenyl beta-d-xylopyranoside. However, it released only arabinose from native cell wall polysaccharides prepared from Japanese pear and from sugar beet arabinan. The enzyme did not release xylose from arabinoxylan and xylan. The only activity of the alpha-L-arafase presented here was hydrolyzing the arabinosyl residue from native polysaccharides, whereas it showed bifunctional activity against artificial substrates. According to the expression pattern and properties of the enzyme, it is a new member of the glycoside hydrolase family 3 isolated from fruit, and it may be responsible for modification of the cell wall architecture during fruit softening.

A proteomic approach to identification of transmembrane proteins and membrane-anchored proteins of Arabidopsis thaliana by peptide sequencing

A proteomic approach was developed for the identification of membrane-bound proteins of Arabidopsis thaliana. A subcellular fraction enriched in vacuolar membranes was prepared from 4-week-old plants and was washed with various agents to remove peripheral membrane proteins and contaminating soluble proteins. The remaining membrane-bound proteins were then subjected to proteomic analysis. Given that these proteins were resolved poorly by standard two-dimensional gel electrophoresis, we subjected them instead to SDS-polyacrylamide gel electrophoresis and to protein digestion within gel slices with lysylendopeptidase. The resulting peptides were separated by reverse-phase high-performance liquid chromatography and subjected to Edman sequencing. From the 163 peptide peaks analyzed, 69 peptide sequences were obtained, 64 of which were informative. The proteins corresponding to these peptide sequences were identified as belonging to 42 families, including two subfamilies, by comparison with the protein sequences predicted from annotation of the A. thaliana genome. A total of 34 proteins was identified definitively with protein-specific peptide sequences. Transmembrane proteins detected in the membrane fraction included transporters, channels, receptors, and unknown molecules, whereas the remaining proteins, categorized as membrane-anchored proteins, included small GTPases, GTPase binding proteins, heat shock protein 70-like proteins, ribosomal proteins, and unknown proteins. These membrane-anchored proteins are likely attached to membranes by hydrophobic anchor molecules or through tight association with other membrane-bound proteins. This proteomic approach has thus proved effective for the identification of membrane-bound proteins.

Advantages of oxygen inhalation therapy for postoperative pulmonary hypertension

Total correction was performed in a case of complete transposition of the great arteries (TGA) with severe pulmonary vascular obstructive disease (PVOD). Although severe pulmonary hypertension remained after surgery, oxygenation was continued for 15 months, which included a shift to at-home oxygen inhalation therapy (HOT). Cardiac catheterization 15 months after surgery demonstrated that pulmonary hypertension was greatly improved. For patients in whom the palliative Mustard operation is considered due to severe PVOD on the basis of lung biopsy diagnosis, total correction of TGA is possible by employing HOT after surgery.

Engineered sorbitol accumulation induces dwarfism in Japanese persimmon

A cDNA encoding sorbitol-6-phosphate dehydrogenase (S6PDH), which is a key enzyme in sorbitol biosynthesis in Rosaceae, was introduced into the Japanese persimmon (Diospyros kaki) to increase the environmental stress tolerance. Resultant transformants exhibited salt-tolerance with dwarfing phenotypes. Therefore, we studied two transgenic lines to understand the physiological mechanism of this dwarfism: lines PS1 and PS6 accumulated high and moderate levels of sorbitol, respectively. The average length of shoots was significantly shorter as compared with the wild-type in line PS1, while no such decrease was observed in line PS6. The myo-inositol and glucose 6-phosphate (G6P) contents were measured in the transgenic lines because previous work with tobacco transformed with S6PDH had suggested that growth inhibition was due to depletion of these metabolites. Although the myo-inositol content was decreased in PS1 plants, the decrease was much smaller than that observed in transgenic tobacco that accumulates sorbitol. The G6P contents were the same in PS1 plants and phenotypically normal PS6 plants. The level of indole-3-acetic acid (IAA), which affects stem elongation, in line PS1 was similar to the levels in the other lines. A decrease in gibberellin (GA) content generally induces dwarfism in plants. However, GA was not decreased in PS1 plants compared with wild-type or control plants. Therefore, we focused on sorbitol accumulation as the most remarkable feature of PS1 plants. As one possibility, the observed growth inhibition was likely caused by an osmotic imbalance between the cytosol and vacuole.

Identification of Sorbitol Transporters Expressed in the Phloem of Apple Source Leaves

Sorbitol is a major photosynthetic product and a major phloem-translocated component in Rosaceae (e.g. apple, pear, peach, and cherry). We isolated the three cDNAs, MdSOT3, MdSOT4, and MdSOT5 from apple (Malus domestica) source leaves, which are homologous to plant polyol transporters. Yeasts transformed with the MdSOTs took up sorbitol significantly. MdSOT3- and MdSOT5-dependent sorbitol uptake was strongly inhibited by xylitol and myo-inositol, but not or only weakly by mannitol and dulcitol. Apparent K(m) values of MdSOT3 and MdSOT5 for sorbitol were estimated to be 0.71 mM and 3.2 mM, respectively. The protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP), strongly inhibited the sorbitol transport. MdSOT3 was expressed specifically in source leaves, whereas MdSOT4 and MdSOT5 were expressed in source leaves and also in some sink organs. MdSOT4 and MdSOT5 expressions were highest in flowers. Fruits showed no or only weak MdSOT expression. Although MdSOT4 and MdSOT5 were also expressed in immature leaves, MdSOT expressions increased with leaf maturation. In addition, in situ hybridization revealed that all MdSOTs were expressed to high levels in phloem of minor veins in source leaves. These results suggest that these MdSOTs are involved in sorbitol loading in Rosaceae.

Purification and characterization of two soluble acid invertase isozymes from Japanese pear fruit

Two isozymes (AIV I and AIV II) of soluble acid invertase (EC 3.2.1.26) were purified from Japanese pear fruit through procedures including (NH(4))(2)SO(4) precipitating, DEAE-Sephacel column chromatography, Concanavalin A (ConA)-Sepharose affinity chromatography, hydroxyapatite column chromatography and Mono Q HR 5/5 column chromatography. The specific activities of purified AIV I and AIV II were 2670 and 2340 (nkat/mg protein), respectively. AIV I was a monomeric enzyme of 80 kDa, while AIV II may be also a monomeric enzyme, which is easy to be cleaved to 52 kDa and 34 kDa polypeptide during preparation by SDS-PAGE. The Km values for sucrose of AIV I and AIV II were 3.33 and 4.58 mM, respectively, and optimum pH of both enzyme activities was pH 4.5.

Pulmonary vascular changes induced by unilateral pulmonary venous obstruction

The relation of pulmonary hemodynamics to pathological change in the pulmonary vasculature was examined in a model of unilateral pulmonary venous (PV) obstruction. The left upper pulmonary vein (A group, n=6) or both the left upper and left lower pulmonary veins (B group, n=6) of two-week-old piglets were banded; the control group (n=6) was sham operated. At eight weeks after PV banding, mean pulmonary arterial pressure was highest in the B group, intermediate in the A group and lowest in the control group. In all groups, the media of the pulmonary artery was equally thickened in both lungs, whereas the media of the pulmonary vein was thickened only in those lung lobes having stenotic pulmonary veins. For all animals from three groups, left pulmonary arterial wedge pressure (PAWP) correlated with medial thickness of the pulmonary arteries of the right lung (r=0.76, p=0.003), the left upper lobe (r=0.54, p<0.03), the left lower lobe (r=0.49, p=0.04). This finding suggests that the pathogenesis of PAWP-related medial thickening of the bilateral lung pulmonary artery begins with the sensing by the bilateral lung of PV pressure buildup in the unilateral lung.

Changes in the phosphorylation state of sucrose synthase during development of Japanese pear fruit

Changes in the protein level and phosphorylation state of sucrose synthase (SS) were studied throughout the development of Japanese pear fruit. The level of SS protein was high at the young stage, dropped with fruit enlargement and increased again with fruit maturation. Antibody against phospho-Ser reacted with SS from young fruit, but did not react with SS that had been dephosphorylated by alkaline phosphatase (AP). The activities of SS isozymes were separated by ion-exchange chromatography. It was found that the fluctuation in SS activity was caused by two SS isozymes (SSI and SSII); (SSI reacted with antibody against phospho-Ser, while SSII did not. Phosphorylation of SS affected its kinetic parameters, that is, the affinity of phosphorylated SS for UDP was higher than that of dephosphorylated SS, while it was the contrary for UDP-glucose. The reaction of dephosphorylated SS was inclined toward sucrose synthesis more than that of phosphorylated SS. Phosphorylated SS protein was most abundant in young fruit, but decreased with fruit development, while non-phosphorylated SS protein increased in mature fruit. These results suggest that SS isoforms may be affected by post-translational modifications such as phosphorylation, and that the regulation of phosphorylation may potentially control the properties and functions of SS throughout the development of Japanese pear fruit.

Reduction in recalcitrant pulmonary hypertension after operation for atrial septal defect

We present the case of a patient with atrial septal defect and severe pulmonary hypertension with pulmonary artery peak pressure greater than 110 mm Hg. Open lung biopsy was done prior to the corrective operation, and pathological findings in the small pulmonary arteries included "musculoelastosis" and complete occlusion of 70% of these small arteries and arterioles. The atrial septal defect was closed, and long-term oral prostacyclin therapy was initiated. Pulmonary artery peak pressure decreased to 65 mm Hg 2 years after the operation. This case demonstrates that in a patient with 70% complete occlusion of small pulmonary arteries and arterioles resulting from "musculoelastosis," not only is surgical intervention possible but also pulmonary artery pressure decreases in the long term after operation.

Hypoxia and cold stress on pulmonary venous obstruction

Hemodynamic changes induced by hypoxia and cold stress were examined on the model of pulmonary venous obstruction (PVO) to investigate the mechanism of pulmonary hypertensive crisis. Bilateral pulmonary venous stenosis was surgically created in 7 newborn piglets of the PVO group. Sham operations were performed on 6 piglets of the control group. Following the baseline hemodynamic measurement (FiO2 = 0.3) at 8 weeks after the operation, the piglets were exposed to hypoxia (FiO2 = 0.14) for 10 minutes, and were also exposed to cold stress for 20 minutes. Hypoxia significantly increased mean pulmonary arterial pressure in the PVO group. Hypoxia increased not only pulmonary arterial resistance, but also pulmonary venous resistance in the PVO group. Cold stress did not change pulmonary arterial resistance or pulmonary venous resistance in each group. In the lungs of the PVO group, the medial muscular layer of the pulmonary arteries and pulmonary veins were thickened. This probably accelerates hypoxia-induced vasoconstriction, which in turn increases pulmonary arterial and venous resistances.

[Indication for lung biopsy and usefulness of lung biopsy]

The criteria of open lung biopsy for operative indication were determined on the basis of hemodynamics in each congenital cardiac anomalies with pulmonary hypertension. More than 10.6, 8 and 8 units. m2 of pulmonary vascular resistance (PVR) were considered as indication for open lung biopsy in the patients with complete transposition of the great arteries, complete atrioventricular canal defect and atrial septal defect respectively. Lung biopsy should be done in patients with ventricular septal defect when PVR is more than 8 units. m2 and if it is greater than 4 with the oxygen inhalation test or 6 with the Tolazoline test. The usefulness of lung biopsy was also emphasized on the basis of the postoperative result in which lung biopsy diagnosis has been done.

Molecular cloning of beta-galactosidase from Japanese pear (Pyrus pyrifolia) and its gene expression with fruit ripening

We have cloned a cDNA fragment encoding a beta-galactosidase from Japanese pear (Pyrus pyrifolia) fruit (JP-GAL). It contained an untranslated sequence of 182 nucleotides at the 5' end, a presumptive coding sequence of 2,193 nucleotides and an untranslated sequence of 268 nucleotides including a polyadenylation signal and a poly (A) tail at the 3' end. It encoded a protein with a calculated molecular weight of 80.9 kDa which consists of 731 amino acids. Both the nucleotide and the deduced amino acid sequences showed a 98% sequence identity with that obtained from the apple beta-galactosidase cDNA. The peptide sequence obtained from the purified Japanese pear beta-galactosidase III matched the deduced amino acid sequence of SVSYDHKAIIINGQKRILISG (amino acid 25-45). Northern blot analysis showed that the probe derived from JP-GAL hybridized to a single 2.6 kb RNA. The mRNA was detected solely in the fruit; none was detected in the buds, leaves, roots or shoots of the Japanese pear. The steady-state level of the beta-galactosidase mRNA was measured during fruit ripening in three cultivars, Housui, Kousui (early ripening) and Niitaka (late ripening). The results showed that regardless of the cultivar, no JP-GAL mRNA was detected in the immature fruit. Increment of the mRNA level with fruit ripening coincided with the increase in the beta-galactosidase III activity. Our results showed that the expression of JP-GAL correlated with fruit softening and JP-GAL may be beta-galactosidase III.

Extremely thickened media of small pulmonary arteries in fatal pulmonary hypertension with congenital heart disease--a morphometric and clinicopathological study

There are patients with congenital heart disease and fatal pulmonary hypertension in whom the medial hypertrophy of the small pulmonary arteries is quite beyond the extent of ordinary cases of hypertension, a condition described as pulmonary hypertension with extremely thickened media of small pulmonary arteries (PH/ETM). Lungs from 6 infants, all younger than 2 years of age, who had congenital heart disease and fatal pulmonary hypertension, were analyzed by accurately measuring the media using Suwa's method. In PH/ETM, the media of the small pulmonary arteries was shown to be not only unusually thick, but extending toward the periphery, whereas the intimal changes were unexpectedly mild. In the PH/ETM group, the % wall thickness at a diameter of 50 microm (%Tw(50)), determined from regression analysis, was 23.2+/-1.3%, which was significantly higher than in either the control (10.3+/-1.2%) or ventricular septal defect group (18.9+/-1.6%). In persistent pulmonary hypertension of the newborn (PPHN), it was 22.3+/-1.8%, not significantly different from PH/ETM. The striking medial hypertrophy in PH/ETM and PPHN was apparently confined to small pulmonary arteries and in both conditions is likely to be the result of maldevelopment of these arteries. Surgical intervention may trigger a critical elevation of the pulmonary arterial resistance.

Pulmonary vascular disease in Down's syndrome with complete atrioventricular septal defect

We sought to determine the predisposing factors of pulmonary vascular disease (PVD) in complete atrioventricular septal defect. Down's syndrome is considered a risk factor for PVD, but the progression of PVD differs in each case. Morphometric analysis in autopsied hearts showed that Rastelli type A morphology had a narrower left ventricular outlet and a wider right ventricular outlet than did type C. In 81 consecutive patients with Down's syndrome who underwent cardiac catheterization, we estimated the following variables: Rastelli subtypes, pulmonary vascular resistance, pulmonary-to-systemic flow ratio, patients' age, and operative outcome. The hemodynamic variables in those <1 year old did not differ between the groups with type A and type C. However, all 5 patients with fatal pulmonary hypertension in early infancy had type A morphology. The lung histology revealed that 3 of these patients already had irreversible PVD. At >/=1 year old, those with type A showed a significantly higher pulmonary vascular resistance (p <0.001) and a lower pulmonary to systemic flow ratio (p <0.05) than did those <1 year old. In contrast, neither of these variables in the type C group differed between those >/=1 and <1 year old. Moreover, those with type A had a greater risk of being contraindicated for surgical repair (p <0.05). We suspect, therefore, that type A morphology is an independent risk factor for PVD in those with Down's syndrome associated with this anomaly. This hemodynamic influence could become obvious once patients are >/=1 year old. It may also sometimes result in irreversible PVD even in early infancy.

Purification and characterization of a NAD+-dependent sorbitol dehydrogenase from Japanese pear fruit

NAD+-dependent sorbitol dehydrogenase NAD-SDH, EC 1.1.1.14) from Japanese pear fruit was purified to apparent homogeneity (single band by SDS-PAGE with silver staining), and had a specific activity of 916.7 nKatal/mg protein. The molecular of the native enzyme was calculated to be 160 kDa by gel filtration, whereas SDS-PAGE gave a subunit size of 40 kDa, indicating that the native enzyme is a homotetramer. The protein immunologically reacted with an antibody raised in rabbit against the fusion protein expressed in E. coli harboring an apple NAD-SDH cDNA. The Km, values for sorbitol and fructose were 96.4+/-8.60 and 4239+/-33.5 mM, respectively, and optimum pH for sorbitol oxidation was 9.0 and 7.0 for fructose reduction. Pear NAD-SDH had a very narrow substrate specificity, that is, sorbitol, L-iditol, xylitol and L-threitol were oxidized but not any of the other alcohols tested. These data suggest the structural importance of an S configuration at C-2 and an R configuration at C-4 in the substrate(s). Its enzymatic activity was strongly inhibited both by heavy metal ions such as mercury, and by thiol compounds, such as L-cysteine. However, the addition of zinc ion reversed the enzyme inactivation caused by addition of L-cysteine.

Purification and characterization of two sucrose synthase isoforms from Japanese pear fruit

Two isoforms (SS I and SS II) of sucrose synthase (SS; EC 2.54.1.13) were purified from Japanese pear fruit and their properties were compared. SS I mainly appeared in young fruit and SS II mainly in mature fruit. SS I and SS II were purified to the specific activity of 3.37 and 4.26 (units (mg protein)(-1)), respectively. The MW of native and subunit proteins of SS I and SS II were almost the same and both SSs seemed to be a tetramer composed of an 83 kDa polypeptide. However, the ionic charges of the native proteins and the kinetic parameters of SSs were different. Specifically, the Km value for UDP-glucose in SS I was the same as that for UDP, while the Km value for UDP-glucose in SS II was less than that for UDP. SS II easily reacted for sucrose synthesis than sucrose cleavage compared with SS I. Therefore, it is considered that SS I and SS II play different roles in the utilization of carbohydrate in young and mature fruit, respectively.

Pulmonary vascular changes induced by congenital obstruction of pulmonary venous return

BACKGROUND

Pulmonary venous obstruction (PVO) induces pulmonary arterial hypertension, as well as pulmonary venous hypertension, and jeopardizes the repair of cardiac lesions.

METHODS

Four cases of congenital mitral stenosis and 4 cases of cor triatriatum (Lucas type A), ages ranging from 2 months to 16 years, were histologically examined on pulmonary vasculature. Histometrical analysis was performed on medial thickness and intimal changes of both pulmonary arteries and veins. For comparison, the examination of pulmonary vasculature in ventricular septal defect (VSD) cases was also performed.

RESULTS

Medial thickening and intimal fibrosis, in both pulmonary arteries and veins with widespread lymphangiectasia, were characteristic vascular changes of PVO cases. Medial thickness of pulmonary arteries was correlated with preoperative pulmonary arterial pressure (PAP) (r = 0.77, p = 0.03 for systolic PAP), and greater than that of VSD cases. Medial thickness of pulmonary veins was also greater in PVO cases. Intimal fibrosis of pulmonary arteries and veins was seen extensively at the advanced ages, whereas no plexiform lesions or more advanced stages of pulmonary vascular disease were present.

CONCLUSIONS

Congenital PVO induced progressive medial thickening and intimal fibrosis in pulmonary arteries and veins accompanied by lymphangiectasia. However, no plexiform lesions or more advanced stages of pulmonary vascular disease were present, which may explain the reversibility of pulmonary hypertension due to congenital PVO.

Structural relationship of kappa-type light chains with AL amyloidosis: multiple deletions found in a VkappaIV protein

Two amyloidogenic Bence Jones proteins (Am37 VkappaIV and NIG1 VkappaI) and one non-amyloidogenic protein (NIG26 VkappaIII) were characterized. The protein Am37 had four deletions when compared with the translated germ-line gene sequence: two Ser residues following position 27 (27e, 27f) in CDR1 and two amino acids Pro-44, and Tyr-49 in FR2 were deleted. A strictly conserved salt-bridge-forming amino acid, Asp-82, was replaced by the hydrophobic residue Leu. In a comparative study of amyloidogenic and non-amyloidogenic proteins, five amino acids (Ser-10, Ala-13, Ser-65, Gln-90, and Ile-106) were found to be unique to NIG1 and several other amyloidogenic proteins. Additional substitutions also occur within these proteins. These substitutions might be significant in altering protein folding as well as in contributing to their aggregation as amyloid fibrils.