Adenomatoid serous hyperplasia of sublingual gland: a case report

We present an example of adenomatoid serous lobular hyperplasia of the sublingual gland. Pathologic examination revealed the lesion was composed of multiple aggregates of normal-appearing serous and mucous acini that varied in size. The ratio of serous gland to mucous glands was 7 to 1. We cannot identify the cause of this condition, however, calcium channel blocking agents prescribed for the treatment of this patient's essential hypertension cannot be ruled out as a pathogenetic factor in the development of the lesion.

Purification and characterization of a malic enzyme from the ruminal bacterium Streptococcus bovis ATCC 15352 and cloning and sequencing of its gene

Malic enzyme (EC 1.1.1.39), which catalyzes L-malate oxidative decarboxylation and pyruvate reductive carboxylation, was purified to homogeneity from Streptococcus bovis ATCC 15352, and properties of this enzyme were determined. The 2.9-kb fragment containing the malic enzyme gene was cloned, and the sequence was determined and analyzed. The enzymatic properties of the S. bovis malic enzyme were almost identical to those of other malic enzymes previously reported. However, we found that the S. bovis malic enzyme catalyzed unknown enzymatic reactions, including reduction of 2-oxoisovalerate, reduction of 2-oxoisocaproate, oxidation of D-2-hydroxyisovalerate, and oxidation of D-2-hydroxyisocaproate. The requirement for cations and the optimum pH of these unique activities were different from the requirement for cations and the optimum pH of the L-malate oxidative decarboxylating activity. A sequence analysis of the cloned fragment revealed the presence of two open reading frames that were 1,299 and 1,170 nucleotides long. The 389-amino-acid polypeptide deduced from the 1,170-nucleotide open reading frame was identified as the malic enzyme; this enzyme exhibited high levels of similarity to malic enzymes of Bacillus stearothermophilus and Haemophilus influenzae and was also similar to other malic enzymes and the malolactic enzyme of Lactococcus lactis.

Enhanced gene expression of transforming growth factor-alpha and c-met in rat urinary bladder cancer

To investigate the roles of growth factors in bladder cancer, changes in the expression of messenger RNAs (mRNAs) for several growth factors and their receptors were examined during rat bladder carcinogenesis induced with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Northern blot analysis showed that the contents of mRNAs for transforming growth factor-alpha (TGF-alpha) and c-met/hepatocyte growth factor (HGF) receptor increased with BBN treatment. Epidermal growth factor (EGF) receptor mRNA was hardly affected by the treatment; while mRNA for fibroblast growth factor (FGF) receptor 1 and transforming growth factor-beta (TGF-beta) type II receptor decreased with BBN treatment. A rat bladder tumor cell line, NBT-II, expressed both TGF-alpha and c-met mRNAs, and HGF showed apparent scattering and growth-stimulating effects on the cells. These results indicate the possibility that TGF-alpha produced by a bladder cancer, in addition to urinary EGF, plays a role in the development of bladder cancer, and that enhanced cell motility due to activation of the c-met/HGF receptor participates in the invasion and metastasis of the cancer cells.

Reperfusion of rat heart after brief ischemia induces proteolysis of calspectin (nonerythroid spectrin or fodrin) by calpain

Rat myocardium expresses the 240- and 235-kD polypeptides antigenically related to alpha- and beta-subunits of brain calspectin (nonerythroid spectrin or fodrin), respectively. In the subcellular fractions of the myocardium, alpha-calspectin was found in the 600g, 10,000g, and 100,000g pellets, whereas beta-calspectin was localized to the 10,000g pellet. On the basis of the Na+,K(+)-ATPase activity and the contents of a gap junction protein, the sarcolemma was distributed to the 10,000g and 100,000g pellets, and the intercalated disks were enriched in the 10,000g pellet. Both alpha- and beta-calspectin were proteolyzed by calpain in vitro. The two subunits were also proteolyzed in vivo, when the rat hearts underwent 10 to 60 minutes of global ischemia followed by 30 minutes of reperfusion. The reperfusion following the ischemia induced the proteolysis of alpha-calspectin in the 10,000g and 100,000g pellets, producing the 150-kD fragment. A synthetic calpain inhibitor, calpain inhibitor-1, suppressed the degradation of calspectin in vivo, which indicates that calpain is responsible for the reperfusion-induced proteolysis of calspectin. The inhibitor also improved myocardial stunning. Immunohistochemical study revealed that the proteolysis of alpha-calspectin occurs at the intercalated disks and the sarcolemma after postischemic reperfusion, in accord with the biochemical data. These results suggest that degradation of calspectin partly accounts for the contractile failure of the myocardium after postischemic reperfusion by disrupting the membrane skeleton and the intercalated disks.

Isolation of promoters from Brevibacterium flavum strain MJ233C and comparison of their gene expression levels in B. flavum and Escherichia coli

A promoter probe shuttle vector suitable for the isolation of promoter elements from coryneform bacteria was constructed. This vector carried the neomycin phosphotransferase (NPTII) gene from transposon Tn5 as a reporter gene, and was capable of replication in both Escherichia coli and Brevibacterium flavum. The vector was used in the construction of a B. flavum library of 899 independently isolated promoter clones. Promoters with a wide range of activities in B. flavum, including some very strong promoter elements, were isolated. Comparative analysis suggests that significant differences between B. flavum and E. coli may exist in the determinants of promoter strength.

Myofibroma of the mandible. Clinicopathologic study and review of the literature

A case of mandibular myofibroma in a 2-month-old boy is presented. Including this case, 24 pediatric and 11 adult patients with maxillofacial myofibroma have been reported since 1981. Of the 24 pediatric patients, 15 (62.5%) had lesions affecting the mandible. The adult cases had no mandibular involvement. Histologic evaluation of the tissue specimen revealed an interlacing pattern of spindle-shaped cells with long oval nuclei. Tissue immunohistochemical staining found it to be reactive for antibodies directed against vimentin and alpha-smooth muscle actin, but not desmin, S-100 protein, neuron-specific enolase, or myoglobin. Electron microscopy examination revealed the following cells: myofibroblast-like cells, fibroblast-like cells, and intermediate cells that were similar to the fibroblast-like cells except for the presence of a few microfilaments. Myoblast-like cells were not seen.

Cloning and sequence determination of the aspartase-encoding gene from Brevibacterium flavum MJ233

A 2.5-kb EcoRI fragment containing the aspartase-encoding gene (aspA) of Brevibacterium flavum MJ233 was cloned into plasmid pUC18 using Southern hybridization with the Escherichia coli aspA gene as a probe. The complete nucleotide (nt) sequence of the cloned DNA indicated that the deduced gene product of the Br. flavum aspA is composed of 526 amino acids (aa). Comparison of the aa sequence to the corresponding sequences from E. coli, Bacillus subtilis and Pseudomonas fluorescens revealed 63, 47 and 57% homology, respectively. The aspA product was determined to have a size of approx. 57 kDa by SDS-PAGE.

Transposon mutagenesis of coryneform bacteria

The Corynebacterium glutamicum insertion sequence IS31831 was used to construct two artificial transposons: Tn31831 and miniTn31831. The transposition vectors were based on a gram-negative replication origin and do not replicate in coryneform bacteria. Strain Brevibacterium flavum MJ233C was mutagenized by miniTn31831 at an efficiency of 4.3 x 10(4) mutants per microgram DNA. Transposon insertions occurred at different locations on the chromosome and produced a variety of mutants. Auxotrophs could be recovered at a frequency of approximately 0.2%. Transposition of IS31831 derivatives led not only to simple insertion, but also to cointegrate formation (5%). No multiple insertions were observed. Chromosomal loci of B. flavum corresponding to auxotrophic and pigmentation mutants could be rescued in Escherichia coli, demonstrating that these transposable elements are useful genetic tools for studying the biology of coryneform bacteria.

Histologic activity of the liver in children with transfusion-associated chronic hepatitis C

Adults with chronic hepatitis C develop cirrhosis over a period of 6 to 20 years, but there are few reports of this disorder in children. To determine the histologic activity of chronic hepatitis C in children, we examined 31 biopsy specimens from 25 children (age range 3-16 years) with this disease. All patients were seropositive for antibody to hepatitis C virus by second-generation testing, and for HCV-RNA by the polymerase chain reaction. All cases were transfusion-associated. Patients were divided into two groups according to underlying disease: malignant disease or aplastic anemia (Group A, 17 cases) and non-malignant disease (Group B, eight cases). All patients in Group A, but only one in Group B, had received multiple transfusions. All patients in Group A had received intensive courses of cytotoxic and immunosuppressive agents. The histologic diagnosis was made using the standard criteria and Knodell's histology activity index. Chronic persistent hepatitis was more common in Group B (six patients) than in Group A (three patients). Chronic aggressive hepatitis 2B was found only in Group A (five patients). The mean histology activity index score was higher in Group A than in Group B (8.5 vs. 5.7). Six patients (four in Group A and two in group B) subsequently had a liver biopsy. The pathological diagnosis did not change after the second biopsy in any patient in Group B, while two patients in Group A showed a rapid progression of hepatitis. In each category of the histology activity index, periportal necrosis and intralobular necrosis were more severe in Group A than in Group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Annexin VI binds to a synaptic vesicle protein, synapsin I

Annexin VI bound to > 14 species of proteins in the whole homogenate of rat forebrain in a Ca2+/phosphatidylserine- or phosphatidic acid-dependent manner. When the subcellular fractions of rat forebrain were examined with a blot from a sodium dodecyl sulfate-polyacrylamide gel, each annexin VI-binding protein showed a different distribution, suggesting that annexin VI is a multifunctional protein. Of these proteins, the doublets of M(r) 80,000 were enriched in the purified synaptic vesicles and were identified as synapsin I. Annexin VI bound to the head domain of synapsin I. When the binding of annexin VI to synapsin I was characterized in the native state, the affinity of the binding for Ca2+ (KCa) was 12.6 microM, and the affinity for annexin VI (KD) was approximately 270 nM. Phosphorylation of synapsin I by cyclic AMP-dependent protein kinase and by Ca2+/calmodulin-dependent protein kinase II inhibited the annexin VI binding. The mode of the inhibition was different between the two kinases. These results indicate that annexin VI may modulate the function of synapsin I in a Ca(2+)- and phospholipid-dependent manner.

KN-62, a specific Ca++/calmodulin-dependent protein kinase inhibitor, reversibly depresses the rate of beating of cultured fetal mouse cardiac myocytes

Effects of KN-62 (1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4- phenylpiperazine), a specific Ca++/calmodulin (CaM)-dependent protein kinase inhibitor, were examined on the rate of spontaneous beating and the intracellular Ca++ transient of cultured myocytes from fetal mouse ventricle. KN-62 depressed the rate of beating in a dose-dependent fashion. Spontaneous beating ceased 10 min after the administration of 1 microM KN-62 and recovered gradually after washing with cultured medium. Addition of KN-04 [N-(1-1[P-(5-isoquinolinsulfonyl)benzyl]-2-(4- phenylpiperazinyl)ethyl)-5-isoquinolinsulfonamide; 1 microM], an analog of KN-62, did not change the rate of beating. In the experiment using an intracellular Ca++ fluorescence indicator, fluo-3, KN-62 depressed the fluo-3 intensity at a systolic phase. The kinase activity to syntide-2 of Ca++/CaM kinase II purified from the rabbit heart was inhibited by KN-62, but not by KN-04. Addition of KN-62 inhibited the phosphorylation of phospholamban by Ca++/CaM kinase II in a dose-dependent manner. KN-62 depressed the Ca(++)-pumping ATPase activity in the presence of Ca++ and CaM by 32%. These findings indicate that Ca++/CaM kinase II changes an intracellular Ca++ transient and modulates the rate of beating at least in part.

Annexin VI-binding proteins in brain. Interaction of annexin VI with a membrane skeletal protein, calspectin (brain spectrin or fodrin)

Identification of annexin VI-binding proteins is essential to elucidate the physiological functions of annexin VI. Here, we developed the methods to identify an annexin VI-binding protein and characterized the binding. Annexin VI bound to about 14 species of proteins in the whole homogenate of rat forebrain, when examined with 125I-annexin VI using blots of SDS-polyacrylamide gels. The binding was Ca(2+)-dependent and specific for phosphatidylserine (PS) and phosphatidic acid. A line of evidence indicates that the binding of annexin VI to its target proteins is a protein-protein interaction. One of annexin VI-binding proteins with M(r) 240,000 was enriched in the cytoskeletal fraction and was identified as calspectin (brain spectrin or fodrin). When the binding was examined with purified calspectin in the native state, the Ca2+ affinity (KCa) was 7.6 microM, and the affinity for annexin VI (Kd) was 68 nM. Annexin VI bound to beta subunit of calspectin, but not to alpha subunit. The binding site was localized to the NH2-terminal domain of beta subunit, which contains an actin-binding site and exhibits striking homology with the NH2-terminal regions of dystrophin and alpha-actinin. When the effect of annexin VI on the interaction between F-actin and calspectin was examined by low shear viscometry, annexin VI inhibited the F-actin cross-linking activity of calspectin in a Ca2+/PS-dependent manner. Cosedimentation assay showed that annexin VI dissociates calspectin from F-actin in the presence of Ca2+ and PS. These results suggest that annexin VI can dissociate and redistribute calspectin in a Ca2+/phospholipid-dependent manner under the plasma membrane and that annexin VI may be involved in the regulation of the membrane skeleton of neuronal cells in response to Ca2+.

Cloning and sequencing of the secY homolog from Coryneform bacteria

A conserved domain of the secY genes from Bacillus subtilis, Mycoplasma capricolum and Escherichia coli was used to design degenerate oligodeoxyribonucleotides. These synthetic DNA sequences were used to screen a lambda library of Brevibacterium flavum MJ233. A 1.5-kb KpnI fragment of a recombinant lambda phage containing the secY homology from Br. flavum MJ233 was subsequently subcloned into plasmid pUC118. The complete nucleotide (nt) sequence of the cloned fragment indicated that the deduced gene product of the Br. flavum secY homolog is composed of 440 amino acids (aa) with a deduced M(r) of 47,871. Comparison of this aa sequence to the corresponding sequences from E. coli and B. subtilis revealed a high degree of conservation, and suggested that the Br. flavum secY homolog is a membrane protein containing ten transmembrane segments. In addition, we could identify, downstream from secY, a putative coding sequence of the enzyme adenylate kinase. This gene organization is identical to that observed in the B. subtilis genome.

Isolation and characterization of IS31831, a transposable element from Corynebacterium glutamicum

A transposable element from a coryneform bacterium, Corynebacterium glutamicum ATCC 31831 was isolated and characterized. The element IS31831 is a 1453 bp insertion sequence with 24 bp imperfect terminal inverted repeats. It contains one open reading frame highly homologous at the amino acid level to the transposase of IS1096 from Mycobacterium smegmatis. Both IS31831 and IS1096 exhibit several common characteristics suggesting that they constitute a new family of insertion sequences. IS31831 was isolated by taking advantage of the sucrose sensitivity of coryneform bacteria conferred by expression of the Bacillus subtilis sacB gene. An Escherichia coli/Corynebacterium shuttle vector useful for the isolation of transposable elements from the coryneform group of bacteria was constructed.

Inflammatory pseudotumor in the submandibular region. Clinicopathologic study and review of the literature

A rare case of right submandibular inflammatory pseudotumor in a 63-year-old man is reported. The tumor appeared as a symptomless swelling in the submandibular region and resembled a malignant neoplasm on computed tomographic and magnetic resonance images. Surgical resection was required. The pertinent English and Japanese literature is reviewed, and histologic and electron microscopic findings are discussed.

Bilateral coronoid process hyperplasia and short stature. A case report

A 23-year-old man with bilateral coronoid process hyperplasia and short stature is presented. These findings are characteristic features of trismus-pseudocampylodactyly syndrome. However, in this patient the pseudocampylodactyly component and family history were absent.