Induction of lymphocytes cytotoxic to oral epithelial cells by Streptococcus mitis superantigen

The preparation of a superantigenic fraction F-2 from the culture supernatant of Streptococcus mitis 108, a fresh isolate from human tooth surfaces, was reported previously. Now, to determine the possible pathogenic role of the superantigen in oral mucosal diseases, we examined the cytotoxic effects of human peripheral blood T-cells activated with F-2 on human oral epithelial cells. T-cells activated with F-2 were cytotoxic to the human squamous carcinoma HO-1-N-1 cells derived from the oral mucosa, similar to those activated with Staphylococcus aureus enterotoxin B (SEB). This cytotoxic effect was increased in a dose-dependent manner by the addition of the respective stimulant, F-2 or SEB, to the cytotoxic assay system. F-2 endowed mainly CD8+ T-cells with cytotoxic activity. Pretreatment with human interferon gamma increased the sensitivity of the HO-1-N-1 cells to the cytotoxic effects of F-2-activated T-cells. The F-2-activated T-cells were also cytotoxic to human keratinocytes derived from gingiva. There was no correlation between the degree of cytotoxicity and the levels of tumor necrosis factor alpha in co-cultures of F-2-activated T-cells and HO-1-N-1 cells. A double-chamber plate experiment revealed no cytotoxic effects when the F-2-activated T-cells were separated from the HO-1-N-1 cells. Supernatants of the co-cultures of target and effector cells were not cytotoxic to HO-1-N-1 cells. These findings suggest that the cytotoxic effects of the F-2-activated T-cells on HO-1-N-1 cells were mediated not by soluble factors but by the direct interaction between the activated T-cells and the target cells. The cytotoxicity of the F-2-activated T-cells against HO-1-N-1 cells was markedly inhibited by monoclonal antibodies (MAbs) against CD11a and CD54, but was only slightly inhibited by MAbs against human leukocyte antigen (HLA)-DR and CD2. Thus, the interaction between lymphocyte-function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) was crucial for the F-2-dependent T-cell-mediated cytotoxicity against oral epithelial cells, while HLA-DR and CD2 molecules are not necessarily involved in the cytotoxicity observed.     

On the structure of highly unsaturated fatty acids of fish oils by high resolution nuclear magnetic resonance spectral analysis

Methyl esters of highly unsaturated fatty acid concentrates were prepared from fish oils by the urea-adduct method. The nuclear magnetic resonance spectra of the mixed esters and some related pattern compounds were analyzed. As a result, it was concluded that the structure of highly unsaturated fatty acids has divinylmethane arrangement of the ethylenic bonds and no divinylethane arrangement, and that one methylene group is present between the terminal methyl group and the double bond located at the remotest position from a carboxyl group in the acids.     

Family 3 beta-glucosidase from cellulose-degrading culture of the white-rot fungus Phanerochaete chrysosporium is a glucan 1,3-beta-glucosidase

The substrate specificity of an extracellular beta-glucosidase (BGL) from cellulose-degrading culture of the white-rot fungus Phanerochaete chrysosporium was investigated, using a variety of compounds with beta-glucosidic linkages. Amino acid sequencing data for the purified BGL showed that the enzyme is identical to the glycoside hydrolase (GH) family 3 BGL of the same fungus previously reported [Li, B. and Renganathan, V, Appl. Environ. Microbiol., 64, 2748-2754 (1998)]. The BGL can hydrolyze both cellobiose and cellobionolactone, but cellobionolactone was hydrolyzed very much more slowly than cellobiose. Moreover, cellobionolactone inhibited cellobiose hydrolysis by the BGL, suggesting that this enzyme cannot cooperate with cellobiose dehydrogenase (CDH) in cellulose degradation by P. chrysosporium. In addition to cellobiose, BGL utilized various glucosyl-beta-glucosides, such as sophorose, laminaribiose and gentiobiose, as substrates. Among the four substrates, laminaribiose (beta-1,3-glucosidic linkage) was hydrolyzed most effectively. Moreover, the hydrolytic rate of laminarioligosaccharides increased proportionally to the degree of polymerization (DP), and the activity of BGL even towards laminarin with an average DP of 25 was similar to that towards laminaripentaose (DP 5). Therefore, we conclude that the extracellular BGL from P. chrysosporium is primarily a glucan 1,3-beta-glucosidase (EC 3.2.1.58), which might play a role on fungal cell wall metabolism, rather than a beta-glucosidase (EC 3.2.1.21), which might be involved in the hydrolysis of beta-1,4-glucosidic compounds during cellulose degradation.     

Sevoflurane anesthesia for myotonic dystrophy

We successfully anesthetized a 14-year-old boy with myotonic dystrophy for orthopedic surgery using sevoflurane. Sevoflurane enabled anesthetic induction and tracheal intubation without intravenous anesthetics and muscle relaxants. Sevoflurane also provided stable anesthetic maintenance without intravenous anesthetics. The patient showed rapid anesthetic recovery and adequate spontaneous breathing. We conclude that sevoflurane is a useful anesthetic for patients with myotonic dystrophy.     

Excretion and uptake of putrescine by the PotE protein in Escherichia coli

The structure and function of the polyamine transport protein PotE was studied. Uptake of putrescine by PotE was dependent on the membrane potential. In contrast, the putrescine-ornithine antiporter activity of PotE studied with inside-out membrane vesicles was not dependent on the membrane potential (Kashiwagi, K., Miyamoto, S., Suzuki, F., Kobayashi, H., and Igarashi, K. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 4529-4533). The Km values for putrescine uptake and for putrescine-ornithine antiporter activity were 1.8 and 73 microM, respectively. Uptake of putrescine was inhibited by high concentrations of ornithine. This effect of ornithine appears to be due to putrescine-ornithine antiporter activity because it occurs only after accumulation of putrescine within cells and because ornithine causes excretion of putrescine. Thus, PotE can function not only as a putrescine-ornithine antiporter to excrete putrescine but also as a putrescine uptake protein. Both the NH2 and COOH termini of PotE were located in the cytoplasm, as determined by the activation of alkaline phosphatase and beta-galactosidase by various PotE-fusion proteins. The activities of putrescine uptake and excretion were studied using mutated PotE proteins. It was found that glutamic acid 207 was essential for both the uptake and excretion of putrescine by the PotE protein and that glutamic acids 77 and 433 were also involved in both activities. These three glutamic acids are located on the cytoplasmic side of PotE, and the function of these three residues could not be replaced by other amino acids. Putrescine transport activities did not change significantly with mutations at the other 13 glutamic acid or aspartic acid residues in PotE.     

Two cases of true hermaphrodite: the usefulness of laparoscopic gonadectomy in childhood. A case report

Laparoscopic operation has been an alternative method in not only adults but children. We presented two children with true hermaphroditism who were performed by open gonadectomy and laparoscopic gonadectomy respectively. Both patients at the age of 4, and 2 years showed karyotypes of 46, XX, and were raised as girls. In the first case left ovary and right ovotestis were revealed by open gonadal biopsy and right ovotestis was removed by open surgery. In another case bilateral ovotestes were revealed by laparoscopic gonadal biopsy and resected by laparoscopic procedure. Laparoscopy was very useful for detecting the gonadal structures to confirm the diagnosis in intersex patients. True hermaphrodite is one of uncommon intersex anomalies, therefore the diagnosis should be made to demonstrate the coexistence of both ovarian and testicular tissues definitely. We estimated laparoscopic gonadectomy in pediatric true hermaphrodite and concluded that laparoscopic gonadectomy was as profitable as open gonadectomy.     

Exogenous sphingosine 1-phosphate induces neurite retraction possibly through a cell surface receptor in PC12 cells

Alterations in thyroid function tests are very common in patients with NTI. Multiple, complex, and incompletely understood mechanisms are involved in these abnormalities. Knowledge of these abnormalities is necessary to avoid errors in the diagnosis of thyroid disease. Measurement of serum TSH, free T4, and free T3 levels by direct equilibrium dialysis/RIA methods probably yield most useful (accurate) information in the setting of NTI. Patients with low free T4 by these methods and normal or low TSH have secondary hypothyroidism. This may be due to NTI per se, drugs administered for treatment of NTI, or associated pituitary or hypothalamic disease; the latter consideration may require evaluation of cortisol reserve, PRL, and/or gonadotropins. A serum TSH level above 20-25 microU/mL probably reflects primary hypothyroidism; accompanying findings of goiter, low free T4, and positive antithyroid antibodies help establish the diagnosis. An elevated serum concentration of rT3 argues against hypothyroidism. Studies have demonstrated no discernible benefit of treatment of NTI patients with T4. Some studies have shown a few benefits of treatment with T3 in selected cases, but much more needs to be learned. There is no evidence of harm by treatment of NTI patients with up to replacement doses of T3. As some NTI patients may indeed be hypothyroid, the term ESS should be replaced with NTIS.