Phylogenetic position of kinetoplastid protozoa inferred from the protein phylogenies of elongation factors 1alpha and 2

Partial regions of the mRNA encoding a major part of translation elongation factor 2 (EF-2) from a kinetoplastid protozoan, Trypanosoma cruzi, were amplified by means of polymerase chain reaction and their primary structures were analyzed. The deduced amino acid sequence was aligned with those of other eukaryotic and archaebacterial EF-2s, and the phylogenetic relationships among eukaryotes were inferred by the maximum likelihood (ML) method. ML analyses of EF-2 phylogeny using six different stochastic models of amino acid substitutions consistently suggested that the phylogenetic position of T. cruzi is likely to be closer to higher eukaryotes than that inferred from the phylogeny of small subunit ribosomal RNA (SrRNA). These results are consistent with those for the elongation factor 1alpha (EF-1alpha) phylogeny. When the EF-1alpha and EF-2 phylogenies were totally evaluated, it became much clearer that the divergence of T. cruzi occurred later than that of a mitochondrion-lacking protozoan, Entamoeba histolytica, although this is not conclusive.

Low incidence of point mutations in H-, K- and N-ras oncogenes and p53 tumor suppressor gene in renal cell carcinoma and peritoneal mesothelioma of Wistar rats induced by ferric nitrilotriacetate

An iron chelate, ferric nitrilotriacetate (Fe-NTA, induces renal proximal tubular damage, a consequence of iron-catalyzed free radical reactions, that finally leads to a high incidence of renal cell carcinoma (RCC) in rodents. Previous studies have identified, within 24 h after administration of Fe-NTA, lipid peroxidation products, aldehyde-modified proteins and a variety of modified DNA bases such as 8-hydroxyguanine that may be mutagenic in vivo. In the present study, pathological features of the RCCs were studied, and, in an effort to correlate them with carcinogen-specific molecular events in Fe-NTA-induced carcinogenesis, the H-, K- and N-ras oncogenes and the p53 tumor suppressor gene were investigated for the presence of mutations. Fe-NTA-induced RCCs showed similarity to human RCCs in that they are often invasive, metastatic and fatal. None (0 of 12) of the tumors had mutation in codons 12, 13 and 61 of the H-, K- and N-ras genes by direct sequencing. Only one (1 of 12) tumor with high grade histology revealed a CGC-to-CTC (Arg to Leu) transversion in codon 246 of the p53 gene by the use of single strand conformation polymorphism (SSCP) analysis and direct sequencing. High expression of mutant p53 protein was confirmed by Western blotting and immunohistochemistry. Study of three peritoneal mesotheliomas induced by Fe-NTA revealed no mutation in ras and p53 genes. These results suggest that the ras and p53 genes are not the major targets of mutation in Fe-NTA-induced carcinogenesis of kidney and mesothelium. Instead, p53 mutation may work for potentiation of malignant character in Fe-NTA-induced renal carcinogenesis.

Histaminergic control of mucosal repair in the small intestine

The aim of the present paper was to summarize histamine-mediated repair of rat intestinal mucosa. To evaluate intestinal repair, we examined lipid transport (an index of intestinal mucosal function) after 15 minutes occlusion of the superior mesenteric artery. Rats were pretreated with alpha-fluoromethylhistidine (a suicide inhibitor of histidine decarboxylase, a synthesizing enzyme of histamine), H1-receptor antagonist (chlorpheniramine maleate), H2-antagonist (cimetidine), or H3-antagonist (thioperamide) before ischemia-reperfusion (I/R). Lipid transport to rat mesenteric lymph decreased significantly 24 hours after I/R in all groups tested compared to sham-treated rats. Lipid transport was restored 48 hours after I/R in the vehicle-pretreated control group. Lipid transport was not restored to the control level 48 hours after I/R in rats pretreated with H1-antagonist and a suicide inhibitor of histidine decarboxylase. In contrast, intestinal function was restored to the control level 48 hours after I/R in rats pretreated with H2- and H3-antagonists. These results support our previous findings that newly formed histamine after I/R plays an important role in mucosal recovery through H1-receptors.

Ocular fundus changes in malignant or precocious stroke-prone spontaneously hypertensive rats after administration of antihypertensive drugs

1. Malignant or precocious stroke-prone spontaneously hypertensive rats (M-SHRSP) showed hypertensive ocular fundus changes with severe hypertension, but various anti-hypertensive drugs given over a proper period improved funduscopic findings. 2. We treated a M-SHRSP with SQ29,852 (an angiotensin converting enzyme inhibitor, ACEI) or manidipine (a calcium antagonist) and observed hypertensive vascular changes in the fundus. 3. The M-SHRSP treated with anti-hypertensive drugs lived longer and the hypertensive fundic changes improved in both groups. But there were some differences of histochemical staining reaction on the endothelial cell-surface and mucopolysaccharides accumulations between the treated group of ACEI and the group treated with the calcium antagonist. 4. In the treated group with calcium antagonist, the anionic ion functions of the endothelial cell-surface were impaired and organic retinal or choroidal damages appeared to have deteriorated.

A precise and fast temperature mapping using water proton chemical shift

A new temperature measurement procedure using phase mapping was developed that makes use of the temperature dependence of the water proton chemical shift. Highly accurate and fast measurements were obtained during phantom and in vivo experiments. In the pure water phantom experiments, an accuracy of more than +/- 0.5 degrees C was obtained within a few seconds/slice using a field echo pulse sequence (TR/TE = 115/13 ms, matrix = 128 x 128, number of slices = 5). The temperature dependence of the water proton chemical shift was found to be almost the same for different materials with a chemical composition similar to living tissues (water, glucide, protein). Using this method, the temperature change inside a cat's brain was obtained with an accuracy of more than +/- 1 degree C and an in-plane resolution of 0.6 x 0.6 mm. The temperature measurement error was affected by several factors in the living system (B0 shifts caused by position shifts of the sample, blood flow, etc.), the position shift effect being the most serious.

RNA polymerase II transcribes Dictyostelium untranslatable gene, dutA, specifically in the developmental phase

In Dictyostelium discoideum, a novel type of RNA (dutA RNA), which is untranslatable, cytosolic and 1.3 kb in size, appears specifically after the aggregation stage [Yoshida, H. et al. (1994) Nucleic Acids Res. 22, 41-46]. We here show that the dutA gene is transcribed by RNA polymerase II, based on its alpha-amanitin sensitive nature of in vitro transcriptional activity. We also show that the stage-specific accumulation of dutA RNA is primarily due to the stage-specific enhancement of the transcriptional activity of the gene.

Effect of azelastine on endotoxin-induced airway hyperresponsiveness in mice

We examined the role of lipopolysaccharide (LPS) on the pulmonary inflammatory process in mice, including the release of interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) by macrophages, and investigated the mechanism of action of azelastine (AZ) on the release of these two cytokines. Intratracheal instillation of 1.0 microgram/ml LPS into BALB/c mice caused a significant increase in both IL-1 beta and TNF-alpha in aqueous lung extracts. These changes were modified, under control conditions, by a single dose of 0.05 mg/kg of AZ administered 1 and 11 h after LPS infusion. Intratracheal instillation of LPS also caused a significant increase in bronchial hyperresponsiveness to methacholine (Mch). AZ significantly inhibited Mch responsiveness in LPS-infused mice compared with nontreated control mice. Our results suggested that intratracheal instillation of LPS induces the secretion of macrophage cytokines in the airways of mice, accounting, at least partly, for LPS-induced airway hyperresponsiveness. Our results also indicate that the attenuating effect of AZ on LPS-induced airway hyperresponsiveness could be explained by its inhibitory effect on macrophage cytokine production.

Peculiar enlargement of the nasopharynx in patients with anorexia nervosa

We examined the nasopharynx and brain in 17 patients with anorexia nervosa by CT and compared the findings with those of 44 normal subjects and of 5 patients of the same age with marked emaciation caused by various psychiatric disorders. An enlarged nasopharyngeal space with a flattened posterior wall and enlarged lateral pharyngeal recesses were demonstrated in all patients with anorexia nervosa whose weight was lowest at the time of the CT examination, and these CT features regressed or became normal quickly after they had gained some weight. This characteristic enlargement of the nasopharynx and lateral pharyngeal recesses was observed neither in the markedly emaciated patients (2 with schizophrenia, 1 with major depression, 1 with stupor and the other with an extremely unbalanced diet) nor in 44 normal subjects without emaciation. These features were therefore thought to be characteristic and of diagnostic significance.

Zinc ions antagonize the inhibitory effect of aurothiomalate on glucocorticoid receptor function at physiological concentrations

The water-soluble gold preparation aurothiomalate, which contains gold as Au(I), is frequently prescribed for patients with rheumatoid arthritis as a disease-modifying agent. We report that aurothiomalate negatively modulates glucocorticoid hormone action; it represses the ligand- and DNA-binding activities and the transactivation function of the glucocorticoid receptor. We suggested the existence of endogenous titrating activities of Au(I) because otherwise administration of aurothiomalate to a patient with rheumatoid arthritis would be expected to result in peripheral insensitivity to glucocorticoids and worsen the patient's status. Focusing on metal ions that are present in vivo, we found that Zn(II) counteracts the inhibitory effect of Au(I) on glucocorticoid receptor function. This complementary effect of Zn(II) was observed at physiological concentrations. We suggest that Zn(II) preserves glucocorticoid receptor function in target tissues and maintains hormone responsiveness, even with chrysotherapy.

Superficial spreading type of early gastric lymphomas

Recent advances in diagnostic techniques have increased the apparent incidence of gastric lymphomas at an early stage. However, the clinical features of the superficial spreading type of early gastric lymphoma are not well-documented. We retrospectively examined the clinicopathologic features of 5 patients with the superficial spreading type of early gastric lymphoma. These tumours were MALTomas which had a characteristically difficult diagnosis and indistinct tumour margins, and a high incidence of lymph node involvement was found. We conclude that satisfactory treatment of this neoplasm requires a wide resection of the stomach with extensive lymph node dissection.

Construction and characterization of arginine-specific cysteine proteinase (Arg-gingipain)-deficient mutants of Porphyromonas gingivalis. Evidence for significant contribution of Arg-gingipain to virulence

Arginine-specific cysteine proteinase (Arg-gingipain; formerly, argingipain) is one of the major extracellular proteinases produced by the oral anaerobic bacterium Porphyromonas gingivalis. To determine whether Arg-gingipain is important for periodontopathogenicity of the organism, Arg-gingipain-deficient mutants were constructed via gene disruption by use of suicide plasmid systems. First, Southern hybridization analyses suggested that two separate Arg-gingipain-encoding genes designated rgpA and rgpB existed on 12.5- and 7.8-kilobase pair HindIII chromosomal fragments of P. gingivalis ATCC33277, respectively. rgpA and rgpB single mutants were constructed by mobilization of a suicide plasmid. Then, an rgpA rgpB double mutant was isolated by electroporation with a second suicide plasmid. No proteolytic activity for Arg-gingipain was observed in either the cell extract or the culture supernatant of the rgpA rgpB mutant. The chemiluminescence response of polymorphonuclear leukocytes, which is closely related to their bactericidal function, was not inhibited by the culture supernatant of the rgpA rgpA mutant, while the wild type parent showed a significant inhibition of the response. The result suggests that Arg-gingipain is responsible for disruption of the function of polymorphonuclear leukocytes. In addition, the rgpA rgpB double mutations caused a marked decrease in the hemagglutination of P. gingivalis, indicating that a major part of the hemagglutinin activity of the organism is associated with the two genes. These findings demonstrate that Arg-gingipain makes a significant contribution to the virulence of P. gingivalis.

Total gastrectomy for early gastric cancer

A total gastrectomy was performed in 49 patients with early gastric cancer, and the effectiveness of this procedure was evaluated by reviewing the hospital files of the patients. The reasons for this total gastrectomy were as follows: (1) lymph node dissection for 22 patients, (2) surgeon's choice in reconstruction for 10 patients, (3) modification of the surgery from subtotal to total gastrectomy for seven patients, (4) synchronous multiple cancers for seven patients, and (5) cancer in a stomach remnant for three patients. Of 49 patients, 42 had the cancerous lesions in the upper portion of their stomachs. Lymph node involvement occurred in 5 patients, but not in the supra- or infrapyloric lymph nodes. Postoperative complications such as anastomotic leakage, reflux esophagitis and pancreatic fistula occurred in five, four, and two patients, respectively. Postoperative death, including two patients who died within 30 days after the surgery, occurred in 5 patients. Our study showed that total gastrectomy resulted in excessive unnecessary surgery in 39 out of 49 patients (79.6%). We conclude that a total gastrectomy should not be performed on patients with early gastric cancer except for synchronous multiple cancers and for cancers in a stomach remnant.

The baculovirus cysteine protease has a cathepsin B-like S2-subsite specificity

Autographa californica nuclear polyhedrosis virus (AcNPV) encodes a functional cysteine protease of the papain family which is expressed after infection in Spodoptera fruglperda Sf9 cells. The protease displays an inhibition profile typical for cysteine proteases and is highly active against synthetic peptide substrates. The pH optimum of the bell-shaped pH-activity curve is between 5.0 and 5.5. The best substrate tested is Z-Arg-Arg-MCA which is specific for cathepsin B. The specificity constant (Kcat/Km) of AcNPV protease for this substrate is approximately two times higher than for human cathepsin B. In contrast to human cathepsins, AcNPV protease does not exhibit a discriminating specificity towards neutral hydrophobic residues in the P2 position. These substrates are hydrolysed at a ten-fold lower rate than the P2 arginine containing substrate. The pH activity profile against the Z-Arg-Arg-MCA substrate reveals a pK of 5.35 which can be assigned to a glutamate residue in the S2 subsite pocket. Like in cathepsin B, this residue facilitates the binding of positively charged P2 residues in the primary binding pocket. In this respect, the AcNPV protease resembles cathepsin B more than cathepsins L and S.

Clone bank of the mitochondrial genome of yeast Hansenula wingei

For sequencing, mitochondrial DNA from Hansenula wingei yeast was digested with various restriction enzymes and the resultant DNA fragments were cloned into a pEMBL phasmid vector. Our clone bank consists of 39 overlapping clones which cover the entire 27,694 bp region of the H. wingei mitochondrial genome.

Isolation and sequencing of two cDNA clones encoding rat spleen cathepsin E and analysis of the activation of purified procathepsin E

Cathepsin E (CE) is an intracellular, nonlysosomal aspartic proteinase consisting of two identical subunits with a molecular mass of approximately 42 kDa and has a unique subcellular distribution in various rat tissues. In this study, we determined the complete amino acid sequence of rat spleen CE and examined the activation mechanism of the proenzyme purified from this tissue. Two cDNA clones encoding rat CE, termed pTN05 and pTN1, were isolated. Comparison of the amino acid sequences predicted from the respective cDNA sequences revealed that they were essentially identical, except that pTN1 lacked a sequence corresponding to residues Tyr293-Pro325 of the longer cDNA clone (pTN05). Based on the structural analysis of purified enzyme forms, the CE precursor was found to comprise a signal peptide, a prosequence, and a mature protein region of 19, 39, and 337 (pTN05) or 304 (pTN1) residues, respectively. Despite a high degree of similarity in the overall structure of CE between rat and other mammalian species, the first 11 residues in the NH2-terminal sequence of rat mature enzyme were significantly different from those of other species. The purified pro-CE was analyzed for its conversion to the mature form. The results indicated that the maximal conversion occurred at pH 3.0-4.0 in a temperature- and time-dependent manner by autocatalytic cleavage at the site between Phe39-Ser40. This conversion was highly dependent on the protein concentrations of pro-CE and delayed by the presence of exogenous substrates, suggesting the predominance of intermolecular reaction for its conversion to the mature form.

Phylogenetic place of mitochondrion-lacking protozoan, Giardia lamblia, inferred from amino acid sequences of elongation factor 2

Partial regions of the mRNA encoding a major part of translation elongation factor 2 (EF-2) from a mitochondrion-lacking protozoan, Giardia lamblia, were amplified by polymerase chain reaction, and their primary structures were analyzed. The deduced amino acid sequence was aligned with other eukaryotic and archaebacterial EF-2's, and the phylogenetic relationships among eukaryotes were inferred by the maximum likelihood (ML) and the maximum parsimony (MP) methods. The ML analyses using six different models of amino acid substitutions and the MP analysis consistently suggest that among eukaryotic species being analyzed, G. lamblia is likely to have diverged from other higher eukaryotes on the early phase of eukaryotic evolution.

[Epilepsia partialis continua with an epileptic focus demonstrated by PET and unique MRI findings: report of a case]

We reported a 31-year-old woman with epilepsia partialis continua (EPC) whose epileptic focus was delineated by PET. Neurologic examination revealed EPC in the face around the corner of her mouth, her thumb and forefinger on the left, slight exaggeration in the left biceps brachii reflex, and the digiti quiniti sign on the left. Laboratory tests showed pancytopenia, positive anti-nuclear and anti-DNA antibodies and decreased levels of serum complements, being consistent with systemic lupus erythematosus (SLE). Electroencephalogram showed paroxysmal discharges over the right frontoparietal region. PET with 2-18F-fluoro-2-deoxy-D glucose (FDG) clearly demonstrated a hypermetabolic area in the right frontoparietal cortex. T2-weighted images in MRI revealed reversible high signal intensity area in the right insula, postcentral gyrus and angular gyrus, while there were no abnormal findings in T1-weighted images with or without Gd-DTPA. There are only a few reports of EPC with the epileptic focus delineated by PET. Since a focal increase in glucose metabolism observed in them as well as in the present patient is a consistent indicator of the epileptic focus, the PET study is likely to provide significant information available not only for the diagnosis but also for the treatment of the condition. Finally, to our knowledge, this is the first patient with SLE presenting EPC. It is important to realize that vasculopathy associated with SLE may cause EPC and brain lesions with reversible high signal intensities shown by MRI.

Segmental pancreatectomy for the diagnosis and treatment of small lesions in the neck or body of the pancreas

BACKGROUND/AIMS

To avoid any profound deficit in the pancreatic functions as well as to successfully make a histological diagnosis of such lesions, we performed resections of a small segment of the pancreatic neck or body. This article discusses the practicality of this procedure as well as the complications and evaluation of the pancreatic functions after surgery.

PATIENTS AND METHODS

A segmental pancreatectomy was performed in patients with small lesions of the pancreatic neck or body. There were a total of 24 patients including 11 with hyperplasia, 7 with chronic pancreatitis, 4 with mucinous or serous cystadenoma, and each one with islet cell carcinoma (low-grade malignancy) and carcinoma in situ.

RESULTS

No major complications occurred following surgery. The pancreatic endocrine and exocrine functions were well maintained in all patients except for two with chronic pancreatitis.

CONCLUSIONS

Based on our findings, a segmental pancreatectomy for small lesions in the pancreatic neck or body seems to be a safe and effective procedure for minimizing the postoperative deficit in the pancreatic functions, while it also allows for an accurate diagnosis of lesions that are often difficult to differentially diagnose for malignancy.

The determinant of severe cerebral dysfunction in patients undergoing emergency extracorporeal life support following cardiopulmonary resuscitation

We investigated the factors associated with cerebral dysfunction in patients undergoing extracorporeal life support (ECLS) following conventional advanced cardiac life support (ACLS). The subjects were 9 patients in whom ECLS was started following ACLS because of intractable cardiac arrest. We investigated whether the irreversibility of cerebral dysfunction during ECLS was related to the cardiopulmonary resuscitation (CPR) time, arterial pH and blood gases, hemoglobin concentration (Hb), peak arterial pressure (PAP) before the start of ECLS and total doses of epinephrine and sodium bicarbonate administered during CPR. Two of the 3 patients who recovered consciousness were weaned from ECLS and survived, while all 6 patients who did not recover from coma were not weaned and died. There was no difference in the CPR time, Hb and PAP before the start of ECLS along with total doses of epinephrine and sodium bicarbonate administered during CPR between the patients who recovered consciousness and those who did not. In addition, there was no difference in arterial pH and blood gases except the arterial oxygen tension (PaO2) between the groups. The PaO2 values before the start of ECLS in the patients who remained in coma ranged from 34 to 58 mmHg, whereas those in the patients who recovered consciousness ranged from 132 to 442 mmHg. The PaO2 values before the start of ECLS in the patients who remained in coma were less than 60 mmHg, whereas those in the patients who recovered consciousness were over 60 mmHg. The present study suggests that hypoxemia during CPR may play a major role in severe cerebral dysfunction in patients undergoing ECLS and PaO2 during CPR.

A sensitive ELISA for the characterization of two forms of circulating intercellular adhesion molecule-1 in human plasma

Nine murine monoclonal antibodies (MAbs) raised against recombinant soluble intercellular adhesion molecule-1 (sICAM-1) were evaluated by means of ELISAs, and their neutralizing activity was investigated in two bioassays employing Raji cells activated with phorbol myristate acetate. Three of the MAbs inhibited autoaggregation of the activated cells and adhesion to sICAM-1 fixed on a plastic plate. Non-neutralizing antibody SM1-255 is directed to an epitope that was not recognized by the other eight MAbs. This property enabled us to develop two ELISAs employing SM1-255 as a liquid-phase antibody for the quantitation of sICAM-1 circulating (cICAM-1) in human plasma. One assay, employing non-neutralizing antibody WIS2-11 as a solid-phase, has a sensitivity of two pg/well with coefficients of variation of 3.6-5.8% (within assay) and 5.5-9.5% (between assay). The other assay, employing neutralizing antibody WIS5-85 as a solid-phase, has a sensitivity of four pg/well with coefficients of variation of 2.7-7.2% (within assay) and 9.2-11.2% (between assay). There was a discrepancy between cICAM-1 levels of human plasma determined by these two assays. All samples showed 2- to 5-times higher levels in the assay using WIS2-11 than in that using WIS5-85. The result from the gel electrophoresis employing Western blotting suggests that ICAM-1 circulates in at least two molecular forms with molecular masses of about 85 and 130 kDa and with different reactivities to WIS2-11 and WIS5-85.

Enhancement of FK-506 activities by ganglioside (GM3) in vivo

Influence of FK-506 and ganglioside (GM3) on acquired immunity to Hymenolepis nana reinfection was examined in BALB/c mice. Treatment of mice with FK-506 abolished the acquired immunity to challenge infection with eggs of H. nana when the agent was injected inraperitoneally at daily doses of 9.0 to 11.0 mg/kg (but not 8.5 mg/kg) on days -1, 0, 1, 2, and 3 relative to the challenge. Intravenous injection of GM3 at a daily dose of 10.0 mg/kg could not produce an immunosuppressive effect on the acquired immunity. Combination treatment with 8.5 mg/kg/day FK-506 and 10.0 mg/kg/day of GM3 inhibited the acquired immunity. These results suggest that GM3 will be a good candidate for a clinical supplementary immunosuppressive agent.