Identification of the five hydrophilic residues (Lys-217, Lys-218, Arg-359, His-360, and Arg-513) essential for the structure and activity of vitamin K-dependent carboxylase

Vitamin K-dependent carboxylase catalyzes the posttranslational conversion of glutamic acid to gamma-carboxyglutamic acid in vitamin K-dependent proteins. The clustered charged-to-alanine scanning mutagenesis of bovine carboxylase has identified five distinct candidate regions (I. Sugiura et al., J. Biol. Chem. 271, 17837-17844, 1996) with significant loss-of-function phenotype. To further specify the residues essential for the structure and function of the enzyme, Lys-217, Lys-218, Arg-359, His-360, Lys-361, Arg-513, and Lys-515 were analyzed by substituting to alanine individually. All the mutants except for K217A were expressed in Chinese hamster ovary cells. The carboxylase activities of R359A, H360A, and R513A decreased in parallel with the vitamin K epoxidase activities. Both carboxylations by R359A and H360A were stimulated saturatively at 1 microM factor IX propeptide (proFIX18) concentration, but that by R513A was not at a concentration up to 128 microM. K218A completely lost the enzyme activities but it cross-linked to the propeptide, suggesting that Lys-218 is critical for enzyme activity without affecting propeptide binding. We conclude that Lys-218, Arg-359, and His-360 are involved in the catalytic event, and Arg-513 participates in propeptide binding.

Nucleotide sequence of vitellogenin mRNA in the bean bug, Riptortus clavatus: analysis of processing in the fat body and ovary

The bean bug, Riptortus clavatus, has immunologically distinct yolk proteins, vitellin (Vn)-1 and-2 and their precursors, vitellogenin (Vg)-1 and-2. We have cloned the full nucleotide sequence of Vg-1 cDNA. The deduced amino acid sequence has some similarities to other insect Vgs. It contains two polyserine regions, which are characteristic of other Vgs. Vg-1 mRNA appeared after treatment with the juvenile hormone analogue, methoprene, implying transcriptional regulation. We found four enzymatic cleavage sites in the Vg molecule. Two of them match the consensus for dibasic processing endoprotease, which is also conserved in processing sites for other insect Vgs. We showed that the processing at each site was incomplete, and this resulted in production of more than the five polypeptides which would be expected from four processing sites in the molecule. The physiological significance of multiple polypeptides in insect Vgs is still unclear.

[Non-Hodgkin's lymphoma of the pancreas with elevated serum CA 19-9 and SPAN-1]

A 55-year-old woman was admitted because of progressive jaundice. Blood examination on admission revealed markedly elevated serum levels of CA19-9 and SPAN-1. Abdominal computed tomography revealed a large tumor in the head of the pancreas. Although the patient's jaundice and elevated CA19-9 decreased after percutaneous franshepatic cholangio-drainage, her SPAN-1 level remained elevated. Open biopsy of the pancreatic tumor revealed non-Hodgkin's lymphoma (NHL) (diffuse medium, B cell type), Complete remission was obtained after one course of CHOP therapy. This case suggests that pancreatic tumor with elevated serum CA19-9 and SPAN-1 levels may involve NHL, and may be curable with chemotherapy.

Molecular characterization of the mouse mtprd gene, a homologue of human TPRD: unique gene expression suggesting its critical role in the pathophysiology of Down syndrome

We and others recently isolated a human TPRD gene, possessing a motif of the tetratricopeptide repeat (TPR), from the Down syndrome-critical region (DCR) of chromosome 21q22.2. In this study, we isolated a mouse homologue of TPRD cDNA, mtprd, and examined its expression profile in mouse embryos. The gene was mapped to mouse chromosome 16C3.3-4, consistent with the location of DCR, and encodes 1,979 amino acid residues with 76% identity to TPRD. The mtprd protein has three units of the TPR motif with 91% homology to TPRD. The protein also has two regions homologous to several matrix proteins with 86 and 70% identities to those of TPRD. Several splicing variants of the 5' portion of the open reading frame of mtprd were identified by RT-PCR and sequencing of mRNAs. In situ hybridization showed that mtprd is ubiquitously expressed in mouse embryos but predominantly in the central nervous system, including the telencephalon, mesencephalon, and metencephalon. These results suggest that the TPRD gene is one of the genes responsible for not only the morphological anomalies but also the neurological abnormalities observed in Down syndrome. The presence of splicing variants indicates that the protein may also have several isoforms in mice.

Cloning of cDNA for a cell wall-bound acid invertase from tomato (Lycopersicon esculentum) and expression of soluble and cell wall-bound invertases in plants and wounded leaves of L. esculentum and L. peruvianum

A cDNA, Wiv-1, for an isozyme of acid invertase (EC 3.2.1.26) was cloned from wounded leaves of tomato (Lycopersicon esculentum). The encoded protein had a basic isoelectric point and strong similarity to the amino acid sequences of plant cell wall-bound invertases. The conserved sequence WECPD that is found in all plant cell wall-bound invertases was also found in the deduced protein. These results suggested that Wiv-1 encoded a cell wall-bound acid invertase of tomato. Wounding increased the levels of mRNAs for soluble and cell wall-bound invertases and the activities of these invertases in leaves of L. esculentum and of a related species, L. peruvianum. The induction of Aiv-1 mRNA for the soluble enzyme in wounded leaves was not very strong, while that of Wiv-1 mRNA for the wall-bound enzyme was prominent. The level of Aiv-1 mRNA reached a maximum 48 h after wounding while that of Wiv-1 mRNA continued to rise for up to 96 h. These findings suggested that the genes for the two isozymes responded independently to wounding. The levels in various organs of Aiv-1 and Wiv-1 mRNAs were higher in L. esculentum than in L. peruvianum. Possible roles of cell wall-bound acid invertase in wound response and in developing plant are discussed.

Intensive extrusion and occlusion of water in ganglioside micelles with thermal reversibility

By using a shell-modeling analysis for small-angle scattering data of ganglioside micellar dispersion, we recently reported that the elevation of temperature induces a significant shrinkage of the hydrophilic region of the ganglioside micelle, suggesting that the oligosaccharide chains with sialic acid residues of ganglioside molecules change the conformation, sensitively responding to a change in temperature (Hirai et al., 1996. Biophys. J. 70:1761-1768; J. Phys. Chem. 100:11675-11680). We have carried out further analyses of the temperature dependence of the structural parameters reported previously, and we have found clear evidence of reversible extrusion and occlusion of a large amount of water in the hydrophilic region of the ganglioside micelle in the physiological temperature range of 6-60 degrees C. The present results suggest a remarkable function of ganglioside molecules: they change the hydrophilicity of the cell surface locally as a response to variations in temperature. This phenomenon might be involved in various surface events, such as cell-cell interaction and cell surface-protein interaction.

[Peripheral blood stem cell transplants: clinical considerations and observations in practice in a general hospital]

Of 36 patients with malignant tumors who had been subjected to peripheral blood stem cell harvests (PBSCHs), 22 had undergone peripheral blood stem cell transplants (PBSCTs) since 1993. Flow cytometry recorded higher CD34+ cell yields in the PBSCHs of those patients with high white blood cell (WBC) counts as well as those who had been under intensive chemotherapy. Also, higher CD34+ cell yields were recorded in patients whose peripheral blood WBCs recovered more rapidly from their nadir state. WBC counts recovered rapidly in patients who received transfusions of at least 2.0 x 10(6) CD34+ cells/kg. However, patients with acute non-lymphocytic leukemia (ANLL) demonstrated a delayed recovery in their platelet counts following PBSCT. The mean disease-free survival rate and mean disease-free period were 60% and 12.8 months for the 5 patients with ANLL; and 100% and 11.3 months for the 4 patients with acute lymphocytic leukemia. These findings suggest PBSCT is a safe and effective treatment for patients with malignant tumors following high-dose chemotherapy, and can be performed in a private general hospital.

The effects of coenzyme Q10 treatment on maternally inherited diabetes mellitus and deafness, and mitochondrial DNA 3243 (A to G) mutation

The characteristic clinical features of diabetes mellitus with mitochondrial DNA (mtDNA) 3243(A-G) mutation are progressive insulin secretory defect, neurosensory deafness and maternal inheritance, referred to as maternally inherited diabetes mellitus and deafness (MIDD). A treatment for MIDD to improve insulin secretory defects and reduce deafness has not been established. The effects of coenzyme Q10 (CoQ10) treatment on insulin secretory response, hearing capacity and clinical symptoms of MIDD were investigated. 28 MIDD patients (CoQ10-DM), 7 mutant subjects with impaired glucose tolerance (IGT), and 15 mutant subjects with normal glucose tolerance (NGT) were treated daily with oral administration of 150 mg of CoQ10 for 3 years. Insulin secretory response, blood lactate after exercise, hearing capacity and other laboratory examinations were investigated every year. In the same way we evaluated 16 MIDD patients (control-DM), 5 mutant IGT and 5 mutant NGT subjects in yearly examinations. The insulin secretory response assessed by glucagon-induced C-peptide secretion and 24 h urinary C-peptide excretion after 3 years in the CoQ10-DM group was significantly higher than that in the control-DM group. CoQ10 therapy prevented progressive hearing loss and improved blood lactate after exercise in the MIDD patients. CoQ10 treatment did not affect the diabetic complications or other clinical symptoms of MIDD patients. CoQ10 treatment did not affect the insulin secretory capacity of the mutant IGT and NGT subjects. There were no side effects during therapy. This is the first report demonstrating the therapeutic usefulness of CoQ10 on MIDD.

Cloning and chromosomal localization of a paralog and a mouse homolog of the human transaldolase gene

A sequence homologous to the transaldolase gene (TALDO) was identified in a polymorphic cosmid DNA mapped on human chromosome 11p15 by exon trapping with pSPL3. Analysis of lambda clones contiguous to the cosmid clone showed that the related gene (TALDOR) consists of 8 exons spanning approximately 19kb from the translation start site to the polyadenylation signal. The exon sequence of TALDOR was almost identical with that of TALDO localized on 1p33-34. 1, but its exons corresponding to exons 4 and 5 of TALDO were found to be split by 4 introns in TALDOR. To examine the evolutionary conservation of two genes for transaldolase, we have isolated the cDNA for its mouse homolog and determined the nucleotide sequence covering the complete coding region. Fluorescence in situ hybridization using the cDNA as a probe showed that the mouse transaldolase gene (Taldo) is localized on chromosome 7 F3-F4 as a single copy gene. This chromosomal region is known to be syntenic to human chromosome 11p15 rather than to 1p33-p34.1, suggesting that TALDOR is the ancestral form. The existence of TALDOR implies a duplication of the mammalian transaldolase gene after divergence of rodent and primate.

Interaction of gangliosides with proteins depending on oligosaccharide chain and protein surface modification

By using neutron and synchrotron x-ray small-angle scattering techniques, we investigated the process of the complexation of gangliosides with proteins. We treated monosialoganglioside (G(M1)), disialoganglioside (G(D1a)), and a mixture of G(M1)/G(D1a). Proteins used were bovine serum albumins whose surfaces were modified with different sugars (deoxy-D-galactose, deoxy-L-fucose, deoxymaltitol, and deoxycellobiitol), which were used as model glycoproteins in a membrane. We found that the complexation of gangliosides with albumins greatly depends on the combination of ganglioside species and protein surface modification. With a varying protein/ganglioside ratio in a buffer solution at pH 7, the complexation of G(M1) or G(D1a) with albumins modified by monosaccharides appears to be less destructive for ganglioside aggregate structures in forming large complexes; the complexation of G(D1a) with the albumins modified by disaccharides induces the formation of complexes with a dimeric structure; and the complexation of G(M1) with albumins modified by disaccharides, to form small complexes, is very destructive. The present results show a strong dependence of the interaction between ganglioside and protein on the characteristics of the ganglioside and protein surface, which would relate to a physiological function of gangliosides, such as a function regulating the receptor activity of glycoproteins in a cell membrane.

Identification and cDNA cloning of novel juvenile hormone responsive genes from fat body of the bean bug, Riptortus clavatus by mRNA differential display

Juvenile hormone (JH) induces termination of diapause and initiation of reproductive maturation in the adult female bean bug, Riportus clavatus. Applying PCR-based differential display, we have identified four novel JH-responsive cDNAS, that is, three repressible (JR-1, 2 and 3) and one inducible (JI-1). These DNA fragments were partially sequenced and compared with sequences in the data base. JR-3 was shown to have similarity to the transferrins of other insects, which have been reported as JH-suppressed genes. JI-1 has similarity to vitellogenin of Aedes aegypti. On the other hand, JR-1-1 and 2 have no significant similarity to other known sequences. For JR-1, the full cDNA sequence was determined: it contained 913 bp, encoding 194 amino acid residues with a calculated M.W. of 21,531 Da in the mature protein. A total of six JH-responsive genes or cDNAs (four suppressible and two inducible or stimulated), including the already isolated JH-responsive cyanoprotein genes (CP-alpha and beta), have been isolated and are available for further comparative analysis of gene structure and regulatory mechanisms in the same tissue under the same hormonal conditions.

Mitochondrial deoxyribonucleic acid 3256C-T mutation in a Japanese family with noninsulin-dependent diabetes mellitus

Accumulating reports indicate a relationship between mitochondrial DNA mutation and impaired glucose-induced insulin secretion leading to a subtype of noninsulin-dependent diabetes mellitus. DNA from a 45-yr-old Japanese woman with noninsulin-dependent diabetes mellitus and muscle atrophy was isolated and studied for mitochondrial DNA mutations. We identified a mitochondrial DNA C-T heteroplasmic mutation at nucleotide position 3256. The mutation was located in the transfer ribonucleic acidLeu in a region conserved in evolution. Eight other members of her family were examined for the mutation. Six of them had the same mutation together with noninsulin-dependent diabetes mellitus, and one teenage boy had the mutation and impaired glucose tolerance. The other family member who did not have this mutation had normal glucose tolerance. The enzyme activity of the mitochondrial oxidative phosphorylation pathway in the muscle of the proband was measured. The enzyme activity was decreased in the proband, especially in complex I. This mutation might be responsible for the abnormal glucose metabolism.

Molecular cloning of human Frizzled-6

The Frizzled genes encode receptors for WNTs, secreted glycoproteins implicated in development as well as in carcinogenesis. In this paper, we report molecular cloning of Hfz6, the human homologue of Mfz6. Nucleotide sequence analysis showed that the Hfz6 gene encodes the 706 amino-acid protein with seven transmembrane domains, a cystein-rich domain in the N-terminal extracellular region, two N-linked glycosylation sites, and two cystein residues in the second and third extracellular loops. Hfz6 mRNA 4.4-kb in size was detected in various normal adult and fetal tissues, and a larger amount of Hfz6 mRNA was detected in both fetal lung and fetal kidney. The Hfz6 gene has been mapped to human chromosome 8q22.3-q23.1. In conclusion, we have cloned Hfz6, which encodes a seven-transmembrane receptor with the cystein-rich domain in the N-terminal extracellular region, but without the Ser/Thr-X-Val motif in the C-terminus.

Cloning and characterization of a cDNA encoding the human homolog of tumor necrosis factor receptor-associated factor 5 (TRAF5)

A cDNA encoding the human homolog of the tumor necrosis factor receptor-associated factor 5 (TRAF5) protein has been molecularly cloned from a cDNA library of Human Daudi B cell line. The sequence analysis revealed that the cDNA encoded a protein of 557 aa residues with a calculated molecular weight of 64,236. The encoded protein has typical structural characteristics shown in the TRAF family of proteins and binds to the cytoplasmic region of lymphotoxin-beta receptor more efficiently than to that of CD40 and CD30. The TRAF5 gene was mapped to the human chromosome 1q32.3-q41.1. Overexpression of human TRAF5 activates NF kappa B transcription factor in human 293T kidney cells. These results suggest that the human TRAF5 protein could be involved in the signal triggered by various members of the tumor necrosis factor receptor (TNFR) superfamily including CD40, CD30 and lymphotoxin-beta receptor.

Changes in urinary 6beta-hydroxycortisol/cortisol ratio after birth in human neonates

OBJECTIVE

Urinary 6beta-hydroxycortisol/cortisol (6beta-OHF/C) ratio was measured in human neonates to assess the CYP3A enzyme activity.

METHODS

Urinary 6beta-OHF/C ratio was determined on the day of birth in 94 neonates including those born prematurely. In addition, changes in the ratios after birth were also determined in 81 neonates.

RESULTS

On the day of birth, a significant positive correlation was found between urinary 6beta-OHF/C ratios and gestational age (r = 0.476) and birth weight (r = 0.283). There was no gender difference in the urinary 6beta-OHF/C ratios in human neonates. Furthermore, delivery modes such as cesarean section and vaginal delivery did not appear to affect the urinary 6beta-OHF/C ratio. The mean ratio of urinary 6beta-OHF/C observed in 39 mature neonates (more than 37 weeks of gestational age) was higher than that observed in adults (16.5 vs 9.9). Within 5 days after birth, the ratio rapidly decreased to less than that in adults. In contrast, the mean ratio of urinary 6beta-OHF/C observed in 42 premature neonates (under 37 weeks of gestational age) was significantly lower than that observed in mature neonates (5.3 vs 16.5) and was virtually unchanged during the 14-days after birth. Therefore, no significant difference was observed in the mean ratio of urinary 6beta-OHF/C between mature and premature neonates at 5 days after birth.

CONCLUSION

From these results, it was concluded that on the day of birth, mature neonates might possess a higher activity of CYP3A enzyme compared with premature neonates, and that the CYP3A enzyme activity in mature neonates might be promptly changed at an early stage after birth.

Susceptibility of Helicobacter pylori isolates to metronidazole, clarithromycin and amoxycillin in vitro and in clinical treatment in Japan

BACKGROUND

Primary and acquired resistance to antibiotics is an important factor in determining the reason for treatment failure in Helicobacter pylori infection. We examined the relationship between the susceptibility of H. pylori isolates and the efficacy of chemotherapy.

METHODS

The minimal inhibitory concentrations (MICs) of metronidazole (MNZ), clarithromycin (CLAR) and amoxycillin (AMOX) of 320 H. pylori pre-treatment isolates were determined by the agar dilution method. In 290 patients with peptic ulcers. H. pylori infection was treated by dual or triple combination therapies for 2 weeks: one proton pump inhibitor (30 mg/day lansoprazole or 20 mg/day omeprazole) and one or two antibiotics (500 mg AMOX, 200 mg CLAR or 250 mg MNZ twice a day). MICs were also determined after the treatment failure.

RESULTS

Among the drugs tested, for MNZ and CLAR, 8.1% and 9.1% of the isolates, respectively, were resistant, while no isolate was resistant to AMOX. After unsuccessful treatment using MNZ and CLAR, 66.7% and 70.61% of the isolates changed from sensitive to resistant, respectively. All isolates were sensitive to AMOX after treatment failure.

CONCLUSIONS

The failure of the H. pylori treatment results in the induction of resistance to CLAR and/or MNZ. Regimens with a high cure rate should be used in order to prevent the generation of acquired resistance to antibiotics.

[Microalbumin and N-acetyl-beta-D-glucosaminidase in random spot urine samples as predictors of diabetic nephropathy in the elderly non-insulin dependent diabetic patients]

To determine whether urinary albumin to creatinine ratio (Albumin index) and urinary N-acetyl-beta-D-glucosaminidase (NAG) to creatinine ratio (NAG index) in random spot urine samples can be sued to predict the early stage of diabetic nephropathy in the elderly non-insulin dependent diabetic patients, we measured these concentrations in 150 non-diabetics, 61 diabetics without retinopathy and 56 diabetics with retinopathy. All patients with Albustix-positive urine were excluded. Subjects divided into two groups according to whether they were < 60 years (adult group) or > or = 60 years old (old group). Multiple regression analysis was used to investigate the relationship between NAG index or Albumin index (dependent variable) and independent variables (age, systolic blood pressure, duration of diabetes. HbA1c) in diabetic patients. Diabetic patients with retinopathy showed the highest mean Albumin index, followed by diabetic patients without retinopathy and then non-diabetic patients both in adult group and in old group (p < 0.001, p < 0.001, respectively). Diabetic patients with retinopathy showed the highest mean NAG index, followed by diabetic patients without retinopathy and then non-diabetic patients both in adult group and in old group (p < 0.001, p < 0.001, respectively). Albumin index positively correlated with systolic blood pressure, duration of diabetes and HbA1c (r = 0.18, r = 0.35, r = 0.18, respectively). NAG index positively correlated with age, duration of diabetes and HbA1c (r = 0.18, r = 0.25, r = 0.29, respectively). These results suggest that both NAG index and Albumin index in random spot urine samples may serve as early functional indicators of diabetic nephropathy in elderly diabetics.

Cloning and chromosomal mapping of human casein kinase I gamma 2 (CSNK1G2)

A clone of immature cDNA for human casein kinase I gamma 2 (CSNK1G2) was isolated by screening the human testis cDNA library with a PCR-amplified probe (about 400 bp) representing the kinase domain of rat casein kinase I gamma 2 (CKI gamma 2). Comparison of the entire sequence with that of rat CKI gamma 2 showed that the cDNA contained the complete coding sequence of CKI gamma 2 as well as an intron-like sequence of 1006 bp, part of which was homologous to the Alu sequence. To obtain an insertion-free CSNK1G2 cDNA, PCR cloning was performed based on the above sequence. The amplified 1687-bp fragment was subcloned and sequenced. The predicted amino acid sequence consisted of 416 residues, 94% of which were identical to that of the rat homologue. Although there are two Src homology 3 (SH3) domain-binding motifs (Pro-X-X-Pro consensus), Pro-Lys-Val-Pro and Pro-Ser-Glu-Pro in the C-terminal region of rat CKI gamma 2, only the latter was conserved in the human counterpart. This finding suggests that the latter motif is important for binding to the signal transduction adaptor protein Nck (NCK). The human CSNK1G2 gene was mapped to chromosome 19p13.3 by fluorescence in situ hybridization and PCR analysis of the human/rodent hybrid cell panel.

Production of recombinant Der fI with the native IgE-binding activity using a baculovirus expression system

Der fI is a cysteine protease contained in feces of mites and is one of major mite allergens. Recombinant Der fI (reDer fI) that is produced using a baculovirus expression system contains pro-sequences of different lengths. Most of these can be removed by acid treatment. However, IgE-binding activity of acid-treated reDer fI is lower than that of native Der fI at high protein concentrations, and N-terminal amino acids of acid-treated reDer fI are not uniform. Now, a method for processing of the pro-sequence has been developed by producing reDer fI E(-1)K with baculovirus expression system in which the carboxy terminal amino acid of the pro-sequence (glutamate) was replaced by lysine using site directed mutagenesis. No difference in the amount of production was observed upon introducing the mutation into the pro-sequence. Addition of lysylendopeptidase into the culture medium led to processing of the pro-sequence of reDer fI E(-1)K and proceeded the degradation of the other proteins in the medium. Lysylendopeptidase-treated reDer fI E(-1)K was easily purified with an anion exchange column, resulting in 20% increase of the yield. Lysylendopeptidase-treated reDer fI E(-1)K obtained through these processes was compared with the native Der fI. Although some differences were found in protease activity and reactivity with lectins, their N-terminal amino acid and the IgE-binding activity were the same as those of the native one, indicating its usefulness for diagnostic purpose.

Extracellular production of an intact and biologically active human growth hormone by the Bacillus brevis system

The characteristic features of the Bacillus brevis system are very high productivity of heterologous proteins and very low extracellular protease activity. However, degradation of some heterologous proteins, especially mammalian proteins, can be observed and resulted in a lowering of protein productivity. By using a mutant expressing low levels of proteases and the addition of EDTA to the medium, intact human growth hormone (hGH) was successfully produced with the B. brevis system. Signal peptide modification with higher basicity in the amino terminal region and higher hydrophobicity in the middle region brought about a twelve-fold increase in hGH production. The hGH yield was further elevated to 240 mg L-1 by optimization of culture conditions. Thus, biologically active and mature hGH can be efficiently produced directly in the medium with the B. brevis system.

A highly conserved major histocompatibility complex class I-related gene in mammals

We report here a cDNA sequence of a murine homolog of the human major histocompatibility complex (MHC) class I-related gene, MR1. The analyses revealed unprecedentedly high conservation of MR1 in the alpha1 and alpha2 domains (corresponding to the peptide-binding domains in the classical MHC class I molecules) between human and mouse (predicted amino acid identity: 90 and 89% for the alpha1 and alpha2 domain, respectively), compared to MHC class I and other class I molecules. On the other hand, conservation in the alpha3 domain (73%) is comparable to those of others, suggesting domain-specific conservation of MR1. The localization of the mouse MR1 gene was determined to be chromosome 1H1, which corresponds to the human chromosomal region where the human MR1 gene is located (chromosome 1q25). High conservation of MR1 among mammals suggests that MR1 may be involved in critical conserved biological function(s).

Relation of electrocardiographic left ventricular hypertrophy with and without T-wave changes to systemic blood pressure, body mass, and serum lipids and blood glucose levels in Japanese men

Left ventricular (LV) hypertrophy, especially combined with an abnormal ST-T, is considered 1 of many coronary risk factors. Seven hundred forty-nine Japanese men were selected according to their electrocardiographic findings, i.e., normal electrocardiogram, LV hypertrophy without an abnormal ST-T segment, LV hypertrophy with a flat T wave, and LV hypertrophy with a negative T wave. Coronary risk factors were compared among these 4 age-matched groups. Groups with LV hypertrophy with negative or flat T waves had larger body mass index (24.9 vs 22.9 kg/m2), higher mean systemic blood pressure (111 vs 95 mm Hg), larger LV mass (265 vs 157 g), higher blood glucose (110 vs 100 mg/dl), higher serum triglyceride (148 vs 122 mg/dl), higher total cholesterol (206 vs 198 mg/dl), and lower high-density lipoprotein cholesterol (47 vs 54 mg/dl) than the normal group or the group with LV hypertrophy without T-wave change. Among these risk factors, blood pressure and glucose remained higher even after the adjustment by body mass index or by body mass index and blood pressure. Electrocardiographic LV hypertrophy with a changed T wave signified higher risk of coronary artery disease in Japanese men.

Circadian rhythms of cardiovascular functions are modulated by the baroreflex and the autonomic nervous system in the rat

BACKGROUND

We assessed the hypothesis that the baroreflex and the autonomic nervous system are important in the control of the circadian rhythms of cardiovascular functions.

METHODS AND RESULTS

We continuously measured blood pressure (BP), heart rate (HR), and locomotor activity in sinoaortic denervated (SAD), sympathectomized, and atropine-injected rats by use of a radiotelemetry system. The circadian rhythm of mean blood pressure (MBP) was selectively disrupted in SAD rats under 12-hour light-dark (LD12:12) cycles as a result of an increase in MBP during the light period and disappeared under constant darkness (DD). The locomotor activity and HR were not remarkably affected by SAD. The circadian rhythm of MBP was suppressed in sympathectomized rats by a decrease in the MBP during the dark period, and the abrupt changes in MBP when the lighting was altered were not seen under LD. Under DD, an MBP rhythm similar to that observed under LD was obtained. Sympathectomized rats also showed lower HR levels during the dark period than intact rats under LD cycles. In atropine-injected rats, the MBP and HR increased, especially during the light period, resulting in a reduction of light-dark differences in MBP and HR. The locomotor activity showed an apparent 24-hour variation in the sympathectomized and atropine-injected rats.

CONCLUSIONS

The disruption of the baroreflex selectively eliminates the circadian rhythm of BP, and the circadian rhythms of BP and HR are modulated by the autonomic nervous system in rats. The circadian rhythms of BP and HR are regulated by different mechanisms involving the autonomic nervous system.

Body-surface distribution of changes in activation-recovery intervals before and after catheter ablation in patients with Wolff-Parkinson-White syndrome: clinical evidence for ventricular 'electrical remodeling' with prolongation of action-potential duration over a preexcited area

BACKGROUND

T-wave abnormalities after catheter ablation in patients with manifest Wolff-Parkinson-White (WPW) syndrome have been attributed to a continuation of repolarization abnormalities induced by preexcitation (cardiac memory).

METHODS AND RESULTS

To clarify changes in repolarization properties, we analyzed the activation-recovery interval (ARI) obtained from body-surface maps and the relationship between the activation time (AT) and ARI in 30 patients with WPW syndrome (group A, 18 patients with manifest left-sided accessory pathway; group B, 7 patients with manifest right-sided accessory pathway; and group C, 5 patients with concealed left-sided accessory pathway) before, 1 day after, and 1 week after ablation. The ARI significantly decreased 1 week after ablation compared with before and 1 day after ablation over the preexcited area in groups A and B. Correlation coefficients between the AT and ARI showed a significantly (P<.01) stronger inverse relationship before (r=-.58) and 1 week after (r=-.64) ablation than 1 day after ablation (r=-.46) in groups A and B. In group C, the ARI and correlation coefficients between the AT and ARI showed no significant changes.

CONCLUSIONS

These findings suggest a prolongation of the action-potential duration over the preexcited area before and just after ablation as ventricular "electrical remodeling," a decrease in the inverse relationship between the AT and action-potential duration 1 day after ablation, and a gradual recovery of the action-potential duration over the preexcited area and inverse relationship 1 week after ablation.

A nitric oxide-releasing reagent, S-nitroso-N-acetylpenicillamine, enhances the expression of superoxide dismutases mRNA in the murine macrophage cell line RAW264-7

Murine interferon-gamma (IFN-gamma) stimulates the murine macrophage tumour cell line RAW264-7 to produce nitric oxide (NO). IFN-gamma induces expression of inducible NO synthase (iNOS), manganese superoxide dismutase (Mn-SOD) and copper zinc SOD (CuZn-SOD) in these cells. To investigate the mechanism of induction of SOD expression, we added S-nitroso-N-acetyl penicillamine (SNAP) to RAW264-7 cells. SNAP enhanced the expression of Mn-SOD and CuZn-SOD. These results suggest that when producing NO, RAW264-7 cells express SOD that might protect them from NO toxicity.

Effect of maternal meal ingestion on fetal renal artery resistance

OBJECTIVE

To examine whether maternal meal ingestion affects the fetal circulation in uncomplicated pregnancies.

METHODS

A simple crossover blinded study was designed for late uncomplicated singleton pregnancies. After overnight fasting, two different maternal meal states were tested. In one state, pregnant women had a standard 600-kcal breakfast at 8 AM (phase A). The other state consisted of maintaining fasting (phase B). Both states were assigned to each woman within 3 days in randomized order. Fetal Doppler studies of the umbilical, middle cerebral, and renal arteries and the descending aorta were performed at 7 AM (the fasting state) and at 10 AM (the fed state or the continuous fasting state).

RESULTS

Twenty women underwent the crossover study. Regardless of the maternal meal state, no significant change was observed in the pulsatility index (PI) of either the umbilical artery (n = 20), the middle cerebral artery (n = 19), or the descending aorta (n = 15). However, the PI of the fetal renal artery decreased significantly after maternal meal ingestion (n = 14) (phase A, 2.36 +/- 0.16 versus 2.09 +/- 0.33; P = .021). There was no such change in the PI after prolonged fasting (phase B, 2.44 +/- 0.32 versus 2.39 +/- 0.44; P = .75).

CONCLUSION

Fetal renal artery resistance decreased after maternal meal ingestion in normally grown fetuses during late pregnancy. This decrease in the resistance may be associated with increased fetal urine production after maternal meals.

Screening for imprinted genes by allelic message display: identification of a paternally expressed gene impact on mouse chromosome 18

A systematic screen termed the allelic message display (AMD) was developed for the hunting of imprinted genes. In AMD, differential display PCR is adopted to image allelic expression status of multiple polymorphic transcripts in two parental mouse strains, reciprocal F1 hybrids and pooled backcross progenies. From the displayed patterns, paternally and maternally expressed transcripts can be unequivocally identified. The effectiveness of AMD screening was clearly demonstrated by the identification of a paternally expressed gene Impact on mouse chromosome 18, the predicted product of which belongs to the YCR59c/yigZ hypothetical protein family composed of yeast and bacterial proteins with currently unknown function. In contrast with previous screening methods necessitating positional cloning efforts or generation of parthenogenetic embryos, this approach requires nothing particular but appropriately crossed mice and can be readily applied to any tissues at various developmental stages. Hence, AMD would considerably accelerate the identification of imprinted genes playing pivotal roles in mammalian development and the pathogenesis of various diseases.

[A case report on prosthetic valve dysfunction of the Carpentier-Edwards pericardial bioprosthesis in the tricuspid position associated with remarkable hypoproteinemia]

A 66-year-old woman underwent a second tricuspid valve replacement because of a malfunction of the Carpentier-Edwards pericardial bioprosthesis (CEP) in the tricuspid position 3.5 years after her first mitral and tricuspid valve replacement. The major symptom was lower leg edema and a serum albumin level ranging between 1.5 g/dl and 2.0 g/dl. The remarkable hypoproteinemia might have resulted from impaired albumin synthesis due to liver dysfunction, hemodilution, protein losing gastroenteropathy, and changes in albumin distribution due to edema. Although the explanted CEP showed neither dehiscence nor calcification of the leaflet, fibrous pannus mainly on the ventricular side restricted the mobility of the corresponding leaflet. Patients receiving a CEP in the tricuspid position should receive careful follow-up.

Analysis and typing of the vacA gene from cagA-positive strains of Helicobacter pylori isolated in Japan

Approximately 50% of Helicobacter pylori strains produce a cytotoxin that is encoded by vacA and that induces vacuolation of eukaryotic cells. Mosaicism in vacA alleles was reported, and there are three different families of vacA signal sequences (s1a, s1b, and s2) and two different families of middle-region alleles (m1 and m2). In addition, the vacA genotype of a strain is associated with its cytotoxin phenotype and its capacity to induce peptic ulceration. To clarify the strain diversity of H. pylori in Japan, 87 Japanese clinical isolates of H. pylori (40 from patients with chronic atrophic gastritis, 25 from patients with duodenal ulcer, 16 from patients with gastric ulcer, 3 from patients with both duodenal and gastric ulcers, and 3 from patients with intestinal type gastric cancer) were characterized by vacA typing by PCR and DNA sequencing. Eighty-four of the 87 isolates were s1a/m1, one was s1b/m1, and two could not be typed. Moreover, all isolates in this study were cagA positive. There were no distinct differences between the cytotoxin-producing strains and cytotoxin-nonproducing strains within the 0.73-kb middle region. Japanese strains were highly homologous, with more than 96% identity in this region, in which maximum divergence has been reported. In addition, there were no associations between the specific vacA types and the level of in vitro cytotoxin activity or the clinical consequences. These results indicate that the cagA-positive, s1a/m1-type strains are common in Japan, regardless of the vacA phenotype or clinical outcome.

Changes in the arterial PCO2 during a single night's sleep in patients with obstructive sleep apnea

To investigate the relationship between hypercapnia during sleep and its influence on the PaCO2 during the morning after sleep in patients with obstructive sleep apnea syndrome (OSAS), the transcutaneous PCO2 (PtcCO2) was measured throughout the night, and the arterial blood gases (ABG) were also measured while awake before and after polysomnography in 30 OSAS patients with (n=13, hypercapnic group: HC) and without (n=17, normocapnic group: NC) hypercapnia. Significant differences were observed in the body mass index (p=0.03), the difference between the highest PtcCO2 during sleep and the PtcCO2 during awake before sleep (D-PtcCO2), (HC: 11.l+/-1.7 mmHg; NC: 6.3+/-0.5 mmHg; p=0.0057) and the lowest SaO2 during sleep (p=0.0007). In the HC, the PaCO2 on the morning after sleep (50.0+/-0.14 mmHg) was significantly increased (p=0.0029) compared with the PaCO2 on the night before sleep (47.4+/-1.1 mmHg). In the NC, this phenomenon was not observed. Severe hypercapnia (high D-PtcCO2) during a single night's sleep has a significant effect on the waking PaCO2 immediately following sleep in the HC.

Hypoxaemia in patients with hyperventilation syndrome

We assessed 12 patients with hyperventilation syndrome (HVS) who had experienced hypoxaemia (PaO2 < 60 Torr or SaO2 < 90%) despite the lack of any other organic disease and variability in their blood gas data. Hypoxic and hypercapnic ventilatory responses were measured in nine. Eight of the 12 patients had been referred from other hospitals to our institution for hypoxaemia of unknown origin. Mean PaO2 (n = 12) at rest (non-attack stage) was 87.3 +/- 7.5 Torr (mean +/- SD). Their (n = 9) hypoxic (-0.53 +/- 0.32 l/min/%; range 0.12-0.99) and hypercapnic (2.01 +/- 0.76 l/min/Torr; range 0.69-3.17) ventilatory responses were both within the normal range in our laboratory. The patients with HVS had variable blood gas data, and some of them also exhibited hypercapnia (PaCO2 > 45 Torr). Clinicians who treat patients with HVS should be aware of the possibility of hypoxaemia, even when ventilatory responses are normal. Physicians should also consider HVS as a diagnosis when treating patients with hypoxaemia of unknown origin.

Effects of Helicobacter pylori eradication therapy on hyperammonaemia in patients with liver cirrhosis

BACKGROUND AND AIMS

Helicobacter pylori has strong urease activity. Ammonia produced by H pylori in the stomach can be a source of systemic ammonia in patients with hepatic dysfunction. The effect of the eradication of H pylori on hyperammonaemia was examined in patients with liver cirrhosis.

SUBJECTS AND METHODS

Ammonia concentrations in blood and gastric juice were analysed in 50 patients with liver cirrhosis and hyperammonaemia. All patients were first treated with a low protein diet, kanamycin, lactulose, and branched chain enriched amino acid solution. Hyperammonaemia remained in 18 patients. These 18 patients were divided into three groups according to the status of H pylori infection; those with a diffuse distribution of H pylori in the stomach (group I), those with a regional distribution (group II), and those without H pylori (group III). These patients were given 30 mg iansoprazole, 1000 mg amoxicillin, and 400 mg clarithromycin or 500 mg metronidazole for two weeks to eradicate H pylori.

RESULTS

In group I ammonia concentrations in blood and gastric juice were significantly reduced after H pylori eradication. The blood ammonia concentration at 12 weeks after the eradication was still significantly lower than that before eradication. In groups II and III the ammonia concentrations in blood and gastric juice were not significantly reduced after eradication therapy.

CONCLUSIONS

The diffuse distribution of H-pylori in the stomach contributes partly to hyperammonaemia in patients with liver cirrhosis, and the eradication of H pylori is effective in patients with hyperammonaemia with diffuse H pylori infection in the stomach.

The effect of viscosity of semen diluents on motility of bull spermatozoa

The effect of egg yolk extender on semen viscosity and bull sperm motility of fresh and cooled or deep frozen semen was determined by a computer-assisted system. Viscosity of the extender was determined by flow time. Based on the sperm velocity (velocity of the average path), individual spermatozoon were classified into groups of progressively motile (>==30 microm/sec) and immotile (<10 microm/sec) spermatozoa. The average velocity of progressively motile spermatozoa (VPM), the velocity of linear progressively motile spermatozoa (VLP) and the percentage of linear swimming spermatozoa (LIN) were evaluated. The addition of 10, 20 or 30% egg yolk to Tris buffer (pH 6.5) resulted in a linear decrease of VPM and a decrease in the percentage of progressively motile spermatozoa, but it increased the relative rate of LIN in fresh diluted semen. Increasing the levels of egg yolk in the diluent resulted in higher viscosity. The VLP was significantly higher than the VPM. In refrigerated or frozen semen samples, extender with 30 and 20% egg yolk had a similar effect on the VPM but not on the percentage of progressively motile sperm cells. Freezing of egg yolk (30%) extender to -20 degrees C resulted in a significant increased flow time and higher viscosity. Dilution of semen samples with high viscosity extender decreased the VPM in fresh and chilled semen. Freezing semen of high viscosity extender with glycerol had no apparent effect on the percentage of progressively motile spermatozoa compared with that of non-glycerinated egg yolk extender. The results suggest that different concentrations of egg yolk in the extender can influence the parameters of semen viscosity and sperm motility evaluated by a computer-assisted system.

Relationship between expression level of P-glycoprotein and daunorubicin transport in LLC-PK1 cells transfected with human MDR1 gene

P-Glycoprotein-mediated transcellular transport and intracellular accumulation of [3H]daunorubicin were examined in cell monolayers with different levels of P-glycoprotein. The porcine kidney epithelial cell line LLC-PK1 was transfected with MDR1 cDNA, and four sublines, LLC-GA5, LLC-GA5-VLB4, LLC-GA5-COL10, and LLC-GA5-COL150, were obtained by culturing the cells in the absence or in the presence of 4 ng/mL vinblastine, 10 ng/mL colchicine, and 150 ng/mL colchicine, respectively. Western blot analysis showed a large difference in P-glycoprotein expression within these sublines. The degree of drug resistance was dependent on the expression level of P-glycoprotein. The amount of the unidirectional transport of [3H]daunorubicin by P-glycoprotein corresponded to the expression level of P-glycoprotein, which was followed by the decrease in intracellular accumulation of the agent. The concentration of cyclosporin A required for the inhibition of P-glycoprotein-mediated transport of [3H]daunorubicin was higher in cells with a high expression of P-glycoprotein. These findings suggest that the transport of daunorubicin by P-glycoprotein and its inhibition by cyclosporin A correspond to the expression level of P-glycoprotein.

YAC and cosmid contigs encompassing the Fukuyama-type congenital muscular dystrophy (FCMD) candidate region on 9q31

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. We had mapped the FCMD gene to an approximately 5-cM interval between D9S127 and D9S2111 on 9q31-q33 and had also found evidence for linkage disequilibrium between FCMD and D9S306 in this candidate region. Through further analysis, we have defined another marker, D9S172, which showed stronger linkage disequilibrium than D9S306. A yeast artificial chromosome (YAC) contig spanning 3,5 Mb, which includes this D9S306-D9S172 interval on 9q31, has been constructed by a combination of sequence-tagged site, Alu-PCR, and restriction mapping. Also, cosmid clones subcloned from the YAC were assembled into three contigs, one of which contains D9S2107, which showed the strongest linkage disequilibrium with FCMD. These contigs also allowed us to order the markers as follows: cen-D9S127-(approximately 800 kb)-D9S306 (identical to D9S53)-(approximately 700 kb)-A107XF9-(approximately 500 kb)-D9S172-(approximately 30 kb)-D9S299 (identical to D9S774)-(approximately 120 kb)-WI2269-tel. Thus, we have constructed the first high-resolution physical map of the FCMD candidate region. The YAC and cosmid contigs established here will be a crucial resource for identification of the FCMD gene and other genes in this region.

[Successful treatment of heavy-chain disease with etoposide]

A 79-year-old man with marked hepatosplenomegaly and lymphadenopathy was admitted to the hospital. Analysis of serum protein resulted in the diagnosis of gamma-chain disease (total protein 6.2 g/dl, M-protein positive, IgG 4150 mg/dl, IgG-Fc fragment positive). Specimens obtained by lymph node biopsies showed infiltration of plasmacytoid cells, which were stained with anti-IgG but not with anti-kappa or anti-lambda antibodies. The patient was given combination chemotherapy, but without effect. Then a regimen of long-term administration of low-dose etoposide was begun, and resulted in remission of the lymphadenopathy, hepatosplenomegaly, and abnormal IgG.

[Successful pulmonary thromboendarterectomy in a patient with chronic pulmonary thromboembolism]

A 63-year-old patient had been diagnosed with angina pectoris for 5 months and came to us complaining of progressive exertional dyspnea. Echo cardiography showed remarkable pulmonary hypertension and we were prompted to do cardiac catheterization. The catheterization showed the pressure of the main pulmonary artery (PA) as 84/14 (36) mmHg and PA angiography showed a massive embolus in the right main PA. Chest computed tomography and lung perfusion scintigraphy were also compatible with pulmonary embolism. The patient had been treated with anticoagulant for 1 month, but he was not doing well. We decided to remove the embolus surgically. In a median sternotomy, a cardiopulmonary bypass was established with ascending aortic and two caval cannulae. During cooling, the right PA was mobilized within the pericardial reflection. An incision was made in the right PA. An organized thrombus was located at the central PA and extended to the distal segmental PA. Thromboendarterectomy was carried out carefully. To obtain a better operative view, circulatory arrest was introduced intermittently. The left PA was opened and the organized thrombus, located at the bifurcation between the upper and lower branch, was removed. Post-operative PA angiography showed remaining thrombus in the right lower PA, but the pressure of the main PA fell to 27/12 (18) mmHg. Pulmonary thromboendarterectomy by median sternotomy with the aid of deep hypothermia and circulatory arrest was useful to remove the thrombus in the bilateral PA, and to obtain good hemodynamic and symptomatic results.

Uterine sarcoma: can it be differentiated from uterine leiomyoma with Doppler ultrasonography? A preliminary report

Our objective was to evaluate whether intratumoral-blood flow analysis could differentiate uterine sarcoma from uterine leiomyoma. Color and pulsed Doppler findings obtained from 41 patients with histologically proven uterine leiomyoma and five with uterine sarcoma (four leiomyosarcoma, one mixed mesodermal tumor) were retrospectively assessed. Intratumoral blood flow velocity waveforms were recorded, and the resistance index (RI) and peak systolic velocity (PSV) were calculated. There was no significant difference between the RI (median 0.647; range 0.422-0.896) in the uterine leiomyomas and the RI (median 0.663; range 0.330-0.774) in the uterine sarcomas. The PSV (median 61.6 cm/s; range 40.0-124.0 cm/s) in the uterine sarcomas was significantly higher (median 21.6 cm/s, range 6.3-48.6 cm/s) than that in the uterine leiomyomas (p < 0.05). When a cut-off value for the PSV of 41.0 cm/s (mean PSV of the uterine leiomyomas plus 2 standard deviations) was considered, the detection rate for uterine sarcoma was 80.0%, and the false-positive rate was 2.4%. These results suggest that the PSV within the tumor detected by color and pulsed Doppler ultrasonography could be useful for the preoperative differential diagnosis of uterine sarcoma.

Identification of a mouse homolog for the human hereditary haemochromatosis candidate gene

Recently, a novel human major histocompatibility complex (MHC) class I-like gene (HLA-H) was reported as a candidate gene for human hereditary haemochromatosis, a recessive disease of iron metabolism with a remarkably high incidence in northern Europeans. Independently we have isolated this gene in the course of a search for new human MHC class I-related genes and named it MR2. Here we report a mouse homolog of this human gene. The mouse MR2 gene is similar to the human counterpart with an overall predicted amino acid sequence similarity of approximately 66% and it is expressed in various tissues as in human. The extra eight amino acid residues between the alpha1 and the alpha2 domains in the mouse molecule compared to the human counterpart can be explained by the creation of the coding sequence from the intron. While the human gene is located at the site telomeric to the MHC region on human chromosome 6, our study indicated the translocation of the mouse homolog from the site telomeric to the MHC on mouse chromosome 17 to chromosome 13 along with other genes. This mouse gene should be important in clarifying a possible role in iron metabolism.

Inactivation of p16/CDKN2 and p15/MTS2 genes in different histological types and clinical stages of primary ovarian tumors

To define the involvement of p16/CDKN2 and p15/MTS2 inactivation in ovarian tumorigenesis and the association of these inactivation events with histological types and clinical stages of ovarian tumors, we analyzed homozygous deletion and somatic mutation of p16/CDKN2 and p15/MTS2 genes, as well as hypermethylation of the 5'-CpG island of the p16/CDKN2 gene, in 49 primary ovarian tumors and 6 ovarian carcinoma cell lines. We found homozygous deletions of p16/CDKN2 and p15/MTS2 in 6 (12%) and 5 (10%) primary tumors, respectively. Somatic mutation of p16/CDKN2 was found in only 1 primary tumor, but mutation of p15/MTS2 was not detected in any sample. None of the 28 primary tumors or 6 cell lines was hypermethylated at the 5'-CpG island of p16/CDKN2. The incidence of inactivation of p16/CDKN2 in primary tumors was significantly higher in the advanced stages (7 of 29) than in the early stages (0 of 14). Seven of 9 alterations in p16/CDKN2 and p15/MTS2 were observed in serous (3 of 12), endometrioid (3 of 9) and clear-cell (1 of 4) carcinomas. However, only normal sequences of these genes were detected in mucinous carcinomas. Loss of heterozygosity (LOH) at the IFNA locus was detected in 1 of 19 (5%) tumors, but no change at the D9S171 locus was observed in 17 tumors. These results suggest that: (i) homozygous deletion is the main mechanism of inactivation of p16/CDKN2 and p15/MTS2 in ovarian tumorigenesis; (ii) inactivation of p16/CDKN2 and p15/MTS2 may be the histological type-specific events involved in ovarian tumorigenesis; and (iii) inactivation of p16/CDKN2 is potentially involved in the progression of ovarian tumors in advanced stages.

cDNA cloning, expression and characterization of nitric-oxide synthase from the salivary glands of the blood-sucking insect Rhodnius prolixus

Rhodnius prolixus, a blood-sucking bug, is a unique insect that is known to produce nitric oxide (NO) in the salivary glands to use as a vasodilator for blood sucking. We report here the cloning of the NO synthase (NOS) cDNA from these salivary glands and its expression in a baculovirus system. This cDNA encodes a protein of 1174 amino acids with a calculated molecular mass of 132,331 Da. The primary structures of mammalian NOS, including the putative cofactor-recognition sites for heme, tetrahydrobiopterin (BH4), calmodulin. FMN, FAD and NADPH are all conserved in salivary-gland NOS. Recombinant salivary-gland NOS differed from nerve NOS and endothelial NOS in that it lacked a large N-terminal domain and an N-terminal myristylation sequence, respectively. Salivary-gland NOS produced in a baculovirus system showed NOS activity and demonstrated that salivary-gland NOS was soluble and was Ca2+ and calmodulin dependent, similarly to mammalian constitutive NOS isoforms. Recombinant salivary-gland NOS was purified to near homogeneity and migrated at 130 kDa on SDS/PAGE.