Immunochemical Characterization of Cell Wall Protein Antigen Purified from the Cell Wall Autolysate of Clostridium botulinum Type A

The cell wall protein antigen was solubilized from the isolated cell walls of Clostridium botulinum type A by autolysis and purified by diethylaminoethyl-cellulose column chromatography followed by gel filtration on Sephadex G-150. The two fractions showed a high degree of the serological activity and produced a main fused precipitin line in immunodiffusion tests against the homologous antiserum. The fact that antigenic fractions contained various kinds of amino acids but no detectable amounts of amino sugars or carbohydrates suggests that the antigens were principally composed of proteins. The protein antigen possessed multiple antigenic components on immunoelectrophoresis. As serological activity, the antigen was heat-stable and resistant to tryptic digestion but sensitive to the actions of pronase, nagarse or pepsin. The protein antigen appeared to be responsible for the common antigenicity among the proteolytic strains of C. botulinum.     

Modification of lymphokine-activated killer cell accumulation into tumor sites by chemotherapy, local irradiation, or splenectomy

The effects of chemotherapy or local irradiation on lymphokine-activated killer (LAK) cell accumulation into tumor sites were investigated. Lymphokine-activated killer cells labeled with 111In-oxine were injected into the caudal vein of C57BL/6 mice that had been previously transplanted with 3LL cancer. An adoptive transfer of LAK cells was carried out 4 days after treatments. Twenty-four hours after the transfer, tumor tissues were excised, and the accumulation of labeled LAK cells in the tumor was measured. In two different experiments, LAK cell accumulation in tumor in the nontreated group was 2.15% and 1.58% of the administered dose per gram of tissue. The accumulation in the groups of mice treated with cyclophosphamide, nimustine hydrochloride, or Adriamycin increased fourfold (7.38% dose/g, 6.61% dose/g), threefold (6.47% dose/g) and twofold (4.46% dose/g), respectively, as compared with the nontreated group. These agents induced significant tumor regression. In the group treated with bleomycin, which showed no significant effect on tumor growth, LAK cell accumulation in tumor remained unaltered (1.57% dose/g). However, the group treated with local irradiation, which induced significant tumor reduction, showed no increase in LAK cell accumulation into tumors. These results suggest that some antitumor drugs enhance LAK cell accumulation into tumor sites and that this increase is due to tumor modification by antitumor drugs.     

Two Dictyostelium tyrosine kinase–like kinases function in parallel,stress-induced STAT activation pathways

When Dictyostelium cells are hyperosmotically stressed, STATc is activated by tyrosine phosphorylation. Unusually, activation is regulated by serine phosphorylation and consequent inhibition of a tyrosine phosphatase: PTP3. The identity of the cognate tyrosine kinase is unknown, and we show that two tyrosine kinase–like (TKL) enzymes, Pyk2 and Pyk3, share this function; thus, for stress-induced STATc activation, single null mutants are only marginally impaired, but the double mutant is nonactivatable. When cells are stressed, Pyk2 and Pyk3 undergo increased autocatalytic tyrosine phosphorylation. The site(s) that are generated bind the SH2 domain of STATc, and then STATc becomes the target of further kinase action. The signaling pathways that activate Pyk2 and Pyk3 are only partially overlapping, and there may be a structural basis for this difference because Pyk3 contains both a TKL domain and a pseudokinase domain. The latter functions, like the JH2 domain of metazoan JAKs, as a negative regulator of the kinase domain. The fact that two differently regulated kinases catalyze the same phosphorylation event may facilitate specific targeting because under stress, Pyk3 and Pyk2 accumulate in different parts of the cell; Pyk3 moves from the cytosol to the cortex, whereas Pyk2 accumulates in cytosolic granules that colocalize with PTP3.     

Comparison of CGRP distributions in the maxillary sinus and trigeminal ganglion between elderly dentulous and edentulous humans

Thickening of the Schneiderian membrane (SM, mucosa of the maxillary sinus) appears in the paranasal sinus. Information on SM thickening is available for patients receiving sinus lift treatments, which is a risk factor for SM excretory dysfunction. However, more information is needed on the structure of the SM and the relationship between the maxilla sinus and palatine with the alveolar bone and the SM for dental implant treatment in the human maxilla. One hundred twenty-six sides of the maxilla from 71 cadavers were subjected to cone-beam computed tomography analysis and macroscopic and immunohistochemical observations in this study. A thickened SM was mainly observed in the middle region of the basal layer of the maxillary sinus (MS). Strong calcitonin gene-related peptide (CGRP)-positive reactions were observed in the alveolar bone, oral mucosa, mucosa of the MS, and trigeminal ganglion (TG) cells in dentulous samples compared with edentulous samples. TG cells play important roles in delivering CGRP through axons to the mucosal gland and in regulating the maxilla-related thickening of the SM. These data could help determine CGRP functions in the mucosal gland and bone formation between dentulous and edentulous samples and indicate that CGRP may pass from the TG to the MS glands.Key words: Mucosa, maxillary sinus, cone-beam computed tomography, immunohistochemistry, calcitonin gene-related peptide, trigeminal ganglion     

Zoo Animal Feeding: A Natural History Viewpoint

In order to formulate animal feeding programs, zoos traditionally borrow knowledge and techniques, developed for domesticated animals, from livestock industry. Although livestock industry provides some of the basic components of feeding it is aimed at economic gain from animals, and the number of species it covers is extremely small. Moreover, wild animals are forced to make considerable adjustments to captivity in all aspects of life, and limitations of domesticated animal models should be recognized and examined. There exists a dire need to increase utilization of knowledge on food habits of wild animals acquired by field biologists, in our effort to improve zoo animal husbandry. Natural history attracts limited interest by zoos. However, it offers a wealth of information which needs to be explored to benefit zoo animal feeding practices.     

Lack of the bone remodeling in osteopetrotic (op/op) mice associated with microdontia.

Osteopetrosis is an inherited metabolic disease characterized by an excessive accumulation of bone. This is associated with an osteoclast deficiency. Osteopetrosis is always accompanied by the failure and/or delay of tooth eruption. The present study was conducted to examine in detail the morphological and histological changes of growth of the third molars in the osteopetrosis (op/op) mouse. At the age of 10 days, normal and op/op mice showed no detectable difference in the shape of the third molar follicles. However, the third molars in the op/op mouse became obscured by the proliferation of neighboring bone trabeculae. Moreover, no tartrate-resistant acid phosphatase-positive cells were detected on the bone surfaces of 10-day-old op/op mice. Ankylosis between the root dentin and proliferating bone trabeculae was a common feature in the 20- and 30-day-old op/op mice. The third molars erupted into the oral cavity before the age of 30 days in normal mice, and the crowns, roots, and periodontal ligaments appeared well developed. Throughout the experiment, it seemed that the primary cause of the microdontia and ankylosis of the developing root in the mutant mouse was a deficiency of osteoclasts, with attendant lack of bone remodeling.     

Expression of salmon growth hormone in the cyanobacteriumAgmenellum quadruplicatum

Summary The salmon growth hormone gene was introduced into the cyanobactriumAgmenellum quadruplicatum PR-6 by plasmid transformation. The gene expressed the hormone under thetrp promoter ofEscherichia. coli. The amount was estimated to be approximately 0.1% of the total cell protein.