[Head and neck cancer]

Before CDDP was clinically used, combination chemotherapy regimens like BLM + MMC, VCR + MTX-LV + BLM, VCR + MTX-LV + BLM + MMC had been used for recurrent tumors of the head and neck. In a phase II study with CDDP, we experienced two patients with long-term survival (12, 15+) who were treated with CDDP as a second-line chemotherapy for recurrent tumors. Cisplatin was evaluated as a potentially curative agent. After that, CDDP based regimens have been used as neo-adjuvant setting (first-line chemotherapy). So it became quite difficult to make up a second-line chemotherapy since CDDP based regimens have been used as the first-line chemotherapy. We conducted basic research on second-line chemotherapy for recurrent head and neck cancer: (1) cross-resistance studies on head and neck cancer cell lines resistant to CDDP, 5-FU, MTX and BLM; (2) second line chemotherapy for CDDP + PEP combination chemotherapy, which was developed by us, in human KB cell line; and (3) effects of etoposide plus mitomycin C on head and neck squamous cell carcinoma in monolayer and multicellular tumor spheroid. Based on our long-term experience with chemotherapy for head and neck cancer, and the results of the above-mentioned basic research, we established a policy to select second-line chemotherapy for recurrent head and neck cancer, especially in cases previously treated with chemotherapy.

[Pharmacokinetics of norfloxacin and lomefloxacin in aqueous humour analysed by microdialysis]

The pharmacokinetics of norfloxacin (NFLX) and lomefloxacin (LFLX) in rabbit aqueous humour after instillation of 0.3% solution (20 microliters) and oral administration (20 mg/kg) were investigated by microdialysis. We also measured plasma concentration of fluoroquinolones after oral administration. After instillation, the maximum concentration (Cmax) of NFLX and LFLX in the aqueous humour was 0.80 and 1.20 micrograms/ml, and elimination half time (t1/2) was 130 and 96 min, respectively. After oral administration, the Cmax in plasma of NFLX and LFLX was 2.06 and 1.89 micrograms/ml, and the Cmax in aqueous humour was 0.16 and 0.62 microgram/ml, respectively. t1/2 of NFLX in aqueous humour and plasma was 225 and 295 min, and t1/2 of LFLX was 188 and 175 min, respectively. The ratio of aqueous humour/serum concentration of NFLX and LFLX was 7.8 and 35.3% 4 hrs after oral administration. These results suggest that, after instillation, LFLX penetrated better into the aqueous humour, and was eliminated faster, than NFLX, and that after oral administration, NFLX could not panetrate well into the aqueous humor from the blood.

Bone histomorphometric changes due to differences in calcium intake under metabolic acidosis in rats

Effects of differences in calcium (Ca) intake on bone metabolism under metabolic acidosis were examined by bone histomorphometry in rats. Rats were divided into 5 diets; low Ca (0.02%) diet (LCD), moderate low Ca (0.3%) diet (LmCD), standard Ca (0.62%) diet (SCD), moderate high Ca (1%) diet (HmCD) and high Ca (3%) diet (HCD). Each diet rats were subdivided into the acidotic group given a 1.8% ammonium chloride solution as drinking water and control group given deionized water. Blood and double labeled bone were collected 30 days later. Arterial blood pH was significantly lower, and plasma ionized Ca level and urinary Ca excretion were higher in the acidotic groups than those in the control groups in all diets. Breaking force in femur and bone volume in tibial proximal metaphysis were significantly lower in the acidotic groups than those in the control groups in LCD, LmCD and SCD. In the acidotic groups, osteoid thickness was significantly higher in LCD than that in LmCD, HmCD and HCD. Mineral apposition rate in the acidotic groups was significantly higher in LCD and LmCD than that in HmCD and HCD. These results suggest that bone mineral loss and bone fragility under metabolic acidosis may be accelerated by high turnover of bone metabolism due to insufficient dietary Ca intake, but can be prevented by adequate supplementation of Ca.

Interferon-gamma-inducing factor enhances T helper 1 cytokine production by stimulated human T cells: synergism with interleukin-12 for interferon-gamma production

The novel cytokine interferon-gamma-inducing factor (IGIF) augments natural killer (NK) cell activity in cultures of human peripheral blood mononuclear cells (PBMC), similarly to the structurally unrelated cytokine interleukin (IL)-12. IGIF has been found to enhance the production of interferon-gamma (IFN-gamma) and granulocyte/macrophage colony-stimulating factor (GM-CSF) while inhibiting the production of IL-10 in concanavalin A (Con A)-stimulated PBMC. In this study, when anti-CD3 monoclonal antibody (mAb)-stimulated human enriched T cells were exposed to IGIF, the cytokine dose-dependently enhanced the proliferation of the cells and this could be completely inhibited by a neutralizing antibody against IL-2 at lower concentrations of IGIF. Neutralizing antibody against IFN-gamma had only insignificant inhibitory effects on T cell proliferation at higher concentrations of IGIF. Enzyme-linked immunosorbent assays (ELISA) revealed that, like PBMC, T cells exposed to IGIF produced large amounts of IFN-gamma; however, changes in the production of IL-4 and IL-10 were minimal. IGIF, but not IL-12, significantly enhanced IL-2 and GM-CSF production in T cell cultures, as determined by CTLL-2 bioassay and ELISA, respectively; however, both IGIF and IL-12 enhanced IFN-gamma production by the T cells. When T cells were exposed to a combination of IGIF and IL-12, a synergistic effect was observed on the production of IFN-gamma, but not on production of IL-2 and GM-CSF. In conclusion, IGIF enhances T cell proliferation apparently through an IL-2-dependent pathway and enhances Th1 cytokine production in vitro and exhibits synergism when combined with IL-12 in terms of enhanced IFN-gamma production but not IL-2 and GM-CSF production. Based on structural and functional differences from any known cytokines, it was recently proposed that this cytokine be designated interleukin-18.

Heteroallelic missense mutations of the galactosamine-6-sulfate sulfatase (GALNS) gene in a mild form of Morquio disease (MPS IVA)

Morquio disease (MPS IVA) is an autosomal recessive disorder caused by a deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS) activity. Patients commonly present in early infancy with growth failure, spondyloepiphyseal dysplasia, corneal opacification, and keratan sulfaturia, but milder forms have been described. We report on a patient who grew normally until age 5 years. Her keratan sulfaturia was not detected until adolescence, and she now has changes restricted largely to the axial skeleton. She has experienced only mildly impaired vision. At age 22, thin-layer chromatography of purified glycosaminoglycans showed some keratan sulfaturia. GALNS activity in fibroblast homogenate supernatants was 20 +/- 5% of controls (as compared to 5 +/- 3% of controls in severe MPS IVA, P < .003). Kinetic analysis of residual fibroblast GALNS activity in patient and parents revealed decreased K(m) and increased Vmax in the mother and daughter, but not in the father, compatible with compound heterozygosity. GALNS exons were amplified from patient genomic DNA and screened by SSCP. Two missense mutations, a C to T transition at position 335 (predicting R94C) and a T to G transversion at position 344 (predicting F97V), were found on sequencing an abnormally migrating exon 3 amplicon. Digestion of the amplicon with FokI and AccI restriction enzymes (specific for the R94C and F97V mutations, respectively) confirmed heterozygosity. In fibroblast transfection experiments, heterozygous R94C and F97V mutants independently expressed as severe and mild GALNS deficiency, respectively. We interpret these findings to indicate that our patient bears heteroallelic GALNS missense mutations, leading to GALNS deficiency and mild MPS IVA. Our findings expand the clinical and biochemical phenotype of MPS IVA, but full delineation of the genotype-phenotype relationship requires further study of native and transfected mutant cell lines.

Cloning of the cDNA for human IFN-gamma-inducing factor, expression in Escherichia coli, and studies on the biologic activities of the protein

We have recently reported that a novel molecule, murine IFN-gamma-inducing factor (IGIF) produced by mouse liver cells, possesses potent biologic activities, including the induction of IFN-gamma production by spleen cells and the enhancement of NK cell cytotoxicity. In this paper, we report on the isolation of human IGIF cDNA clones from normal human liver cDNA libraries using murine IGIF cDNA as a probe. The amino acid sequence deduced from the human cDNA clones indicated a 193-amino acid precursor peptide and revealed 65% homology with that of murine IGIF. The amino acid sequence of IGIF also included an IL-1 signature-like sequence. Subsequently, the cloned cDNA was expressed in Escherichia coli, and preliminary studies on the biologic activities of the recombinant protein were performed. The recombinant human IGIF induced IFN-gamma production by mitogen-stimulated PBMC and enhanced NK cell cytotoxicity, in a manner similar to murine IGIF. In addition, recombinant human IGIF also augmented granulocyte-macrophage-CSF production and decreased IL-10 production, but had no effect on IL-4 production by Con A-stimulated PBMC. Based on these pleiotropic effects of IGIF, we propose that this novel cytokine be designated as IL-18.

Cold-induced salt intake in mice and catecholamine, renin and thermogenesis mechanisms

Cold induces increased intake of salt in mice. To examine involvement of renin and catecholamines, male ICR mice were exposed to cold (7-9 degrees C; 6 h/day; 4 days), and half of them were allowed to choose between water and 0.9% NaCl. Plasma renin activity (PRA) and catecholamine concentrations in plasma, adrenal gland, kidney, brown adipose tissue (BAT) and brain were examined in three phases: for 9 h before exposure to cold, during 6 h of cold exposure and for 9 h after the exposure. The amount of salt intake from NaCl solution and from food, PRA and noradrenaline (NE) concentrations in kidney and medulla oblongata were higher during cold and the 9 h after exposure to cold than during the 9 h before the exposure. These results are consistent with the suggestion that cold induced catecholamine metabolism enhanced activity in the renin-angiotensin system, which played an important role in the arousal of salt appetite. During cold exposure, concentrations of NE and dopamine in BAT were higher in mice with access to NaCl solution than those without NaCl to drink. These results suggest that cold-induced salt intake enhanced non-shivering thermogenesis, and are consistent with our previous report that high salt intake helped to maintain colonic temperature under cold exposure.

Cloning of the cDNA for human IFN-gamma-inducing factor, expression in Escherichia coli, and studies on the biologic activities of the protein

We have recently reported that a novel molecule, murine IFN-gamma-inducing factor (IGIF) produced by mouse liver cells, possesses potent biologic activities, including the induction of IFN-gamma production by spleen cells and the enhancement of NK cell cytotoxicity. In this paper, we report on the isolation of human IGIF cDNA clones from normal human liver cDNA libraries using murine IGIF cDNA as a probe. The amino acid sequence deduced from the human cDNA clones indicated a 193-amino acid precursor peptide and revealed 65% homology with that of murine IGIF. The amino acid sequence of IGIF also included an IL-1 signature-like sequence. Subsequently, the cloned cDNA was expressed in Escherichia coli, and preliminary studies on the biologic activities of the recombinant protein were performed. The recombinant human IGIF induced IFN-gamma production by mitogen-stimulated PBMC and enhanced NK cell cytotoxicity, in a manner similar to murine IGIF. In addition, recombinant human IGIF also augmented granulocyte-macrophage-CSF production and decreased IL-10 production, but had no effect on IL-4 production by Con A-stimulated PBMC. Based on these pleiotropic effects of IGIF, we propose that this novel cytokine be designated as IL-18.

Changes in bone metabolism and epiphysial growth plate in bovine Hyena disease induced by administration of vitamin AD3E premix or Vitamin A

The changes in bone metabolism and morphology of chondrocytes in bovine Hyena disease caused by administration of vitamin AD3E premix (V-AD3E) or vitamin A (V-A) were examined. At the each age, 5 calves were used. Among them, Hyena disease was recognized in 3 calves; a calf administered a high dose of V-AD3E premix (V-A 3,000,000, V-D3 300,000, and V-E 1,200 I.U./day), a calf administered a half dose of the V-AD3E premix, and a calf administered only V-A 3,000,000 I.U./day. The remaining calves without Hyena disease were a calf administered only V-D3 300,000 I.U./day and a control calf. Each agent was administered orally for 10 days from 1 week after birth. In the 3 calves with Hyena disease, the bone metabolism in bone histomorphometry of ilium was in the state of low turnover at the age of 50 days. The bone volume was small at the age of 12 months. The epiphysial growth plates of the distal femurs and the proximal tibias partially disappeared and the chondrocyte lacunas in them were flattened. The matrix fibers of epiphysial growth plates were thinner in diameter and higher in density than those of the control calf. In the calf administered only V-D3, the values of bone volume decreased with aging. In conclusion, Hyena disease may be caused by excessive administration of V-A, because hypervitaminosis A suppressed the activity of differentiation and proliferation in chondrocytes and osteoblasts, and excessive administration of V-D3 may promote these actions.

Mucopolysaccharidosis IVA: four new exonic mutations in patients with N-acetylgalactosamine-6-sulfate sulfatase deficiency

We report four new mutations in Japanese patients with mucopolysaccharidosis IVA (MPSIVA) who were heterozygous for a common double gene deletion. A nonsense mutation of CAG to TAG at codon 148 in exon 4 was identified, resulting in a change of Q to a stop codon and three missense mutations. V (GTC) to A (GCC) at codon 138 in exon 4, P (CCC) to S (TCC) at codon 151 in exon 5, and P (CCC) to L (CTC) at codon 151 in exon 5. Introduction of these mutations into the normal GALNS cDNA and transient expression in cultured fibroblasts resulted in a significant decrease in the enzyme activity. V138A and Q148X mutations result in changes of restriction site, which were analyzed by restriction-enzyme assay. P151S and P151L mutations that did not alter the restriction site were detected by direct sequencing or allele specific oligohybridization. Detection of the double gene deletion was initially done using Southern blots and was confirmed by PCR. Haplotypes were determined using seven polymorphisms to the GALNS locus in families with the double gene deletion. Haplotype analysis showed that the common double gene deletion occurred on a single haplotype, except for some variation in a VNTR-like polymorphism. This finding is consistent with a common founder for all individuals with this mutation.

[A surgically treated case of coronary rupture by Palmaz-Schatz stenting]

We report a very rare case of coronary rupture by Palmatz-Schatz stenting. The reported patient, 74-year-old woman, had the stenosis of the left coronary artery. When she received PTCA, and directional coronary atherectomy for the left coronary artery, coronary dissection was developed. Though the coronary stenting using two Palmza-Schatz stents for the dissection was attempted, extravasation of a contrast medium after post dilatation by a balloon was found. Since reupture of the left coronary artery was strongly suspected, the emergency operation was required. Hemostasis and the coronary artery bypass grafting using two saphenous veins were performed successfully. We thought that post dilatation by balloon caused the coronary rupture.

Purification and properties of a novel enzyme, trehalose synthase, from Pimelobacter sp. R48

A novel enzyme, trehalose synthase, was purified from a cell-free extract of Pimelobacter sp. R48 to an electrophoretically homogeneous state by successive chromatographies on DEAE-Toyopearl 650, Butyl-Toyopearl 650, and Mono Q HR5/5 columns. The molecular weight of the enzyme was estimated to be 62,000 by SDS-polyacrylamide gel electrophoresis, and the enzyme had a pI of 4.6 by gel isoelectrofocusing. The enzyme catalyzed the conversion of maltose into trehalose by intramolecular transglucosylation. The enzyme also converted into maltose but was inactive on other saccharides. The N-terminal amino acid of the enzyme was serine. The optimum pH and temperature were pH7.5 and 20 degrees C, respectively. The enzyme was stable in the range of pH 6.0-9.0 and up to 30 degrees C for 60 min. The rate of conversion of maltose into trehalose was independent of the maltose concentration. The maximum yield of trehalose from maltose were 81.8%, 80.9%, and 76.7% at 5, 15, and 25 degrees C, respectively. The activity was inhibited by Cu2+, Hg2+, Ni2+, Zn2+, and Tris.

[A case of familial cardiac myxoma]

We experienced a case of familial cardiac myxoma observed in a mother and her daughter. A 58-year-old woman was addmited to our hospital because of repeated cerebral embolism. Echocardiography showed a left atrial myxoma to be considered as the cause of cerebral embolism. At the operation, 3 myxomas were found in the left atrium, and were removed successfully. No recurrence has been observed for 14 years after the operation. Three years after that, her 3rd child, 31-year-old-women, suffered from cerebral embolism and was also diagnosed as a left atrial myxoma. A friable myxoma was removed with the interatrial septum. She had no recurrence for 11 years after the operation. In patients with cardiac myxoma who have unusual biologic behavior, including familial myxoma, "complex" type myxoma must be suspected. We suggest that it is important to distinguish patients with "complex" type myxoma, because the recurrence rate is much higher in those than in patients with "sporadic" type myxoma.

Experimental studies on bovine Hyena disease induced by administration of excessive vitamin AD3E premix, vitamin A, or vitamin D3

The effects of the excessive administration of the vitamin AD3E(V-AD3E) premix, vitamin A (V-A) or vitamin D3 (V-D3) on experimental development of Hyena disease in the calves were examined. Hyena disease was recognized in 4 calves, both of the 2 calves administered a high dose of V-AD3E premix (V-A 3,000,000, V-D3 300,000, and V-E 1,200 IU/day, V-AD3E group), 1 of the 2 calves administered a half dose of the V-AD3E premix, and 1 of the 2 calves administered only V-A (V-A 3,000,000 IU/day, V-A group) when each vitamin was administered orally for 10 days from 1 week after birth. Both of 2 calves administered only V-D3 (V-D3 300,000 IU/day) did not developed. In the 4 calves with Hyena disease (Hyena calves), the plasma retinylpalmitate showed high values which was suggesting the hypervitaminosis A, and the epiphysial growth plate was narrow and destroyed structure of column. Compared with the Hyena calf in the V-A group, the Hyena calves in the V-AD3E group showed earlier appearance time of Hyena disease, lower growth rate and shorter lengths of fore and hind limb bones. In conclusion, the present findings suggested that excessive V-A administration to suckling calves might cause Hyena disease by V-A effects to the epiphysial growth plate, moreover such effects may be promoted by the V-D3.

Validity of various diagnostic tests to evaluate cure of Helicobacter pylori infection

Many diagnostic methods have been developed and used for detecting Helicobacter pylori to evaluate the success of treatment of H. pylori infection. We investigated and compared the suitability of the rapid urease test (RUT), polymerase chain reaction (PCR), 13C-urea breath test (13C-UBT), and serology with culture for evaluating cure of H. pylori infection. Forty-seven H. pylori-positive gastric ulcer patients received dual therapy of lansoprazole (30 mg u.i.d.) and clarithromycin (200 mg b.i.d.). Four weeks after the completion of treatment, RUT, PCR, 13C-UBT, and culture were performed and the negative rates of these tests were compared. Anti-H. pylori IgG antibodies were measured by enzyme-linked immunosorbent assay (ELISA) before and 4 weeks after completion of the treatment to evaluate changes of titers during the treatment. The negative rate of RUT (55%) was significantly greater than that of culture (27%). Significant declines in titers were seen in the patients who had negative culture results, while the decline in the titer was not significant in the patients who had positive results. PCR assay and 13C-UBT were suitable for the evaluation of H. pylori eradication, but RUT was not suitable, because of its sensitivity. By monitoring anti-H. pylori IgG antibody titers, therapeutic failure can be detected early after completion of treatment.

[Supraannular implantation of bioprosthetic valve for severe tricuspid valve regurgitation associated with atrial septal defect in an adult patient]

With an adult atrial septal defect, there was often regurgitation of the mitral and tricuspid valve due to volume overload in a long term period. Especially concerning tricuspid regurgitation, what can be done surgically has not yet been decided. For severe tricuspid regurgitation, some cases where tricuspid valve annuloplasty were performed have had exacerbation of tricuspid regurgitation. We experienced a case where tricuspid valve supraanular implantation without excision of native tricuspid valve (TVSI) was performed for severe tricuspid regurgitation associated with atrial septal defect, and improved. A 53-year-old female complained of dyspnea on exertion. An atrial septal defect was revealed being 4 cm in size, complicated with severe tricuspid regurgitation (IV), and 62 mmHg difference of pressure from the right atrium to right ventricle shown by a ultrasonography. Pulmonary artery pressure was 66/16 mmHg by cardiac catheter. Patch closure for ASD and TVSI for TR was performed on her, and amelioration of cardiac function was recognized.

[Early intervention for very-low-birth-weight infant]

In order to establish an early intervention (EI) system for very-low-birth-weight infants, we designed a randomized trial at multiple institutions in Japan. We also reviewed the concept and history of early intervention in USA. Eight medical institutions in different locations were selected for participation. Sixty-two EI group patients and 48 controls without neurological abnormalities (age 2 years) were selected for study. The developmental quotient (DQ) by the revised Kyoto-K method and 15 questionnaire items were monitored twice, at the age of 2 and after one year of EI (3 years). Improvements in behavioral problems, circadian rhythm, and speech were significantly greater in the EI group than in the control group. (P < 0.01). Data on all patients are being collected, and further evaluation and analysis of DQ are planned. The most effective EI method in each specific location and the financial support of its official institutions are required for the success of the EI program for very-low-birth-weight infants.

Central nuclei and spinal pathways in feedback inhibitory spinal cord potentials in ketamine-anaesthetized rats

It has been suggested that heterosegmentally activated slow positive potentials (HSP), recorded from the spinal cord of rat and humans, are feedback inhibitory potentials. The present study was carried out to define ascending and descending spinal tracts and the sites of central nuclei involved in the production of these HSP, and the effects of ketamine on these central nuclei. The spinal cords in ketamine-anaesthetized rats were transected to determine the ascending and descending tracts involved in the production of hindpaw (HP) and forepaw (FP) HSP, respectively. Lesions of the brain at various levels were performed stereotactically during ketamine anaesthesia. Dorsal one-third resection of the cord at the T8-9 level did not affect HSP significantly, while contralateral lesion of the dorsal two-thirds of the cord decreased FP-HSP but not HP-HSP during ketamine. Bilateral transection of the ventral one-third of the cord abolished both HSP. Ablation of the cerebral cortex, cerebellum, thalamus, midbrain and pons did not affect HSP significantly. However, transection of the middle medulla decreased, while transection of the most caudal part of the medulla completely abolished both HSP. Ketamine decreased HSP even in the medulla-spinal cord preparation and the segmental slow positive wave in spinalized animals. In ketamine-anaesthetized rats, ascending and descending spinal tracts involved in the production of HP-HSP and FP-HSP are located bilaterally in the ventrolateral quadrant and in the contralateral lateral funiculus and ventrolateral quadrant, respectively. Principal central nuclei feeding back HSP might be situated diffusely in the medulla down to the caudal part. Ketamine is suggested to suppress these inhibitory feedback potentials predominantly at, and partly even below, the level of the medulla.

Lichen planus-like contact dermatitis due to methacrylic acid esters

We report a patient who had lichen planus-like lesions on sites repeatedly exposed to methacrylic acid esters used in the car industry. Histologically, the lesions showed all the features of classical lichen planus. Patch testing revealed positive reactions to methacrylic acid esters in concentrations as low as 5 x 10(-3)%. As dental devices contain methacrylic acid esters, it is possible to speculate that methacrylic acid esters may be one of the causative agents for oral lichen planus.

Purification and characterization of thermostable maltooligosyl trehalose synthase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius

A thermostable maltooligosyl trehalose synthase was purified from a cell-free extract of the thermoacidophilic archaebacterium Sulfolobus acidocaldarius ATCC 33909 to an electrophoretically homogeneous state by successive column chromatography on Sepabeads FP-DA13, Butyl-Toyopearl 650M, DEAE-Toyopearl 650S, Ultrogel AcA44, and Mono Q. The enzyme had a molecular mass of 74,000 by SDS-polyacrylamide gel electrophoresis and a pI of 5.9 by gel isoelectrofocusing. The N-terminal amino acid of the enzyme was methionine. The enzyme showed the highest activity from pH 5.0 to 5.5 and at 75 degrees C, and was stable from pH 4.5 to 9.5 and up to 85 degrees C. The enzyme activity was inhibited by Hg2+ and Cu2+. The Kms of the enzyme for maltotetraose, maltopentaose, maltohexaose, maltoheptaose, and short chain amylose (DP 18) were 41.5 mM, 7.1 mM, 5.7 mM, 1.4 mM, and 0.6 mM, respectively.

Purification and characterization of thermostable maltooligosyl trehalose trehalohydrolase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius

A thermostable maltooligosyl trehalose trehalohydrolase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius ATCC 33909 was purified from a cell-free extract to an electrophoretically pure state by successive column chromatographies on Sepabeads FP-DA13, Butyl-Toyopearl 650M, DEAE-Toyopearl 650S, Toyopearl HW-55S and Ultrogel AcA44. The enzyme had a molecular mass of 59,000 by SDS-polyacrylamide gel electrophoresis and a pI of 6.1 by gel isoelectrofocusing. The N-terminal amino acid of the enzyme was methionine. The enzyme showed the highest activity from pH 5.5 to 6.0 and at 75 degrees C, and was stable from pH 5.5 to 9.5 and up to 85 degrees C. The activity was inhibited by Hg2+, Cu2+, Fe2+, Pb2+, and Zn2+. The Km values of the enzyme for maltosyl trehalose, maltotriosyl trehalose, maltotetraosyl trehalose, and maltopentaosyl trehalose were 16.7 mM, 2.7 mM, 3.7 mM, and 4.9 mM, respectively.

O-glycosylated species of natural human tumor-necrosis factor-alpha

Tumor-necrosis factor-alpha, produced by human B-cell lymphoblastoid cell line BALL-1, was expressed as four protein bands on SDS/PAGE analysis. It may have been glycosylated, based on the fact that the heavier two of the four bands disappeared after neuraminidase treatment. Sugar composition analyses revealed that the tumor necrosis factor-alpha contained galactose, N-acetylgalactosamine and N-acetylneuraminic acid as sugar components. To prepare sugar chains, tumor necrosis factor-alpha was treated with alkaline borodeuteride and the oligosaccharide-alditols liberated were fractionated by gel-filtration chromatography on a Bio-Gel P-4 column, followed by normal-phase HPLC. Three oligosaccharide-alditols were obtained, and the structures of two of them were identified by methylation analysis and exoglycosidase digestion. The structures of these oligosaccharide-alditols were Gal beta 1-3(NeuAc alpha 2-6)GalNAcol and Gal beta 1-3GalNAcol (GalNAcol, N-acetylgalactosaminitol). The structure of the remaining oligosaccharide-alditol was determined to be NeuAc alpha 2-3Gal1-3GalNAcol by composition and methylation analyses. About 20% of tumor necrosis factor-alpha was found to be 0-glycosylated, based on the results of the sugar composition and structure analyses. An amino acid sequence analysis of the glycosylated peptides was performed after Staphylococcus aureus V8 protease digestion of tumor necrosis factor-alpha had been completed, and it was proved that the 0-glycosylation site of tumor necrosis factor-alpha was Ser 4.