Purification and characterization of a thermostable thiol protease from a newly isolated hyperthermophilic Pyrococcus sp

A hyperthermophilic archaeon strain, KOD1, was isolated from a solfatara at a wharf on Kodakara Island, Kagoshima, Japan. The growth temperature of the strain ranged from 65 to 100 degrees C, and the optimal temperature was 95 degrees C. The anaerobic strain was an S0-dependent heterotroph. Cells were irregular cocci and were highly motile with several polar flagella. The membrane lipid was of the ether type, and the GC content of the DNA was estimated to be 38 mol%. The 16S rRNA sequence was 95% homologous to that of Pyrococcus abyssi. The optimum growth pH and NaCl concentration of the strain KOD1 were 7.0 and 3%, respectively. Therefore, strain KOD1 was identified as a Pyrococcus sp. Strain KOD1 produced at least three extracellular proteases. One of the most thermostable proteases was purified 21-fold, and the molecular size was determined to be 44 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 45 kDa by gel filtration chromatography. The specific activity of the purified protease was 2,160 U/mg of protein. The enzyme exhibited its maximum activity at approximately pH 7.0 and at a temperature of 110 degrees with azocasein as a substrate. The enzyme activity was completely retained after heat treatment at 90 degrees C for 2 h, and the half-life of enzymatic activity at 100 degrees C was 60 min. The proteolytic activity was significantly inhibited by p-chloromercuribenzoic acid or E-64 but not by EDTA or phenylmethylsulfonyl fluoride. Proteolytic activity was enhanced threefold in the presence of 8 mM cysteine. These experimental results indicated that the enzyme was a thermostable thiol protease.

High-sensitivity two-dimensional thermal- and mechanical-stress-induced birefringence measurements in a Nd:YAG rod

A novel polarimeter for measuring the two-dimensional (2D) thermal- and mechanical-stress-induced birefringence in solid-state laser materials such as Nd:YAG is proposed. Using this device, we could sensitively measure the direction of the principal birefringence axis as well as the phase shift δ with sign when δ < π/4. The 2D thermal- and mechanical-stress-induced birefringence in a laser-diode-pumped Nd:YAG rod was successfully measured with the proposed polarimeter. We also found an active quarter-wave Nd:YAG phase retarder.

Decrease in deoxyribonucleotide triphosphate pools and induction of alkaline-labile sites in mouse bone marrow cells by multiple treatments with methotrexate

Methotrexate (MTX), an inhibitor of dihydrofolate reductase (DHFR), slightly induced micronuclei in bone marrow and peripheral blood cells, and this induction was enhanced by multiple treatments with the drug. Furthermore, we have suggested that the multiple-dose effect on the induction of micronuclei by MTX might be explained by intracellular accumulation of the drug, resulting in an enhancement of DHFR inhibition. An imbalance or decrease in the deoxyribonucleotide (dNTP) pool would be generated by this enzyme inhibition. Therefore, we attempted to determine the level of the dNTP pool in mouse bone marrow cells. The levels of three dNTPs (dTTP, dATP, dGTP) as determined by HPLC were only 1/10-1/40 of the levels previously found in mammalian cell lines, but dCTP levels could not be determined precisely because they approached the limits of detectability. The levels of dTTP, dATP and dGTP in mouse bone marrow cells 3 h after four injections of MTX (4 mg/kg/day) decreased to 21.2%, 47.0% and 38.1%, respectively, of those in the control group. The level of dTTP 3 h after four injections of 100 mg/kg of the drug decreased to almost 0%. The results of alkaline elution assays suggested that alkaline-labile sites were generated in mouse bone marrow cells 6 h after four injections of MTX (4 mg/kg). These findings suggest that the multiple-dose effects of MTX on micronucleus induction in mouse bone marrow cells may be explained by the decrease in the dNTP pool and subsequent generation of alkaline-labile sites (possibly apurinic/apyrimidinic sites).

Effects of malnutrition on development of experimental pressure sores

Using food-deprived rabbits we investigated the effects of nutritional deficiency on the development of pressure sores. The body weight of these animals was decreased significantly from normal. Organ weights of liver, heart, spleen, kidney, and testis were significantly decreased from normal as well. Protein deficiency in these animals was indicated by serum tests, as well as by histologic features of liver and testis and ultrastructural findings on fibroblasts. We produced lesions in malnourished as well as normal rabbits by exposing their skin to a balloon-produced compressive force of 120 +/- 10 mmHg for 4 hours. Biopsies were taken 1, 2, and 3 days after the pressure application. Histologic findings at each time were as follows: At day one, the degree of ischemic skin destruction in the malnourished animals was more severe than that in the normal ones, and thrombi were occasionally seen in the malnourished cases. At day two, proliferation of fibroblasts and macrophage infiltration were evidenced in the normal animals, whereas signs of collagen fiber degeneration as well as microthrombi were seen in the malnourished ones. At three days, epidermal cells covered the lesions in the case of normal animals; however, massive necrosis of the epidermis was still recognized in the malnourished rabbits. Thus, the healing process of pressure sores was strongly suppressed in the malnourished animals. This suppression was attributed to the reduction in fibroblast proliferation, capillary formation, macrophage infiltration, and also to the low level of epidermal cell proliferation.

Elucidation of the Erwinia uredovora carotenoid biosynthetic pathway by functional analysis of gene products expressed in Escherichia coli

The most important function of carotenoid pigments, especially beta-carotene in higher plants, is to protect organisms against photooxidative damage (G. Britton, in T. W. Goodwin, ed., Plant Pigments--1988, 1988; N. I. Krinsky, in O. Isler, H. Gutmann, and U. Solms, ed., Carotenoids--1971, 1971). beta-Carotene also functions as a precursor of vitamin A in mammals (G. A. J. Pitt, in I. Osler, H. Gutmann, and U. Solms, ed., Carotenoids--1971, 1971). The enzymes and genes which mediate the biosynthesis of cyclic carotenoids such as beta-carotene are virtually unknown. We have elucidated for the first time the pathway for biosynthesis of these carotenoids at the level of enzyme-catalyzed reactions, using bacterial carotenoid biosynthesis genes. These genes were cloned from a phytopathogenic bacterium, Erwinia uredovora 20D3 (ATCC 19321), in Escherichia coli and located on a 6,918-bp fragment whose nucleotide sequence was determined. Six open reading frames were found and designated the crtE, crtX, crtY, crtI, crtB, and crtZ genes in reference to the carotenoid biosynthesis genes of a photosynthetic bacterium, Rhodobacter capsulatus; only crtZ had the opposite orientation from the others. The carotenoid biosynthetic pathway in Erwinia uredovora was clarified by analyzing carotenoids accumulated in E. coli transformants in which some of these six genes were expressed, as follows: geranylgeranyl PPiCrtB----prephytoene PPiCrtE----phytoeneCrtI---- lycopeneCrtY----beta-caroteneCrtZ----zeaxanthinCrtX--- -zeaxanthin-beta- diglucoside. The carotenoids in this pathway appear to be close to those in higher plants rather than to those in bacteria. Also significant is that only one gene product (CrtI) for the conversion of phytoene to lycopene is required, a conversion in which four sequential desaturations should occur via the intermediates phytofluene, zeta-carotene, and neurosporene.

Disorders of bone metabolism caused by small bowel resection in rats

Disorders of bone metabolism caused by resection of three quarters of the small bowel in rats were investigated biochemically and histomorphologically. Metabolic bone disorders developing 90 days after in 75%-distal-small-bowel resected rats were characterized by reduction in ash content of the femur and by the disappearance of the trabecular bone in tibial metaphysis. Biochemical studies showed significant decrease in serum Ca and 1,25-dihydroxyvitamin D concentrations in 75% distal small bowel resected rats. These data suggest that 75% distal small bowel resection impairs intestinal absorption of calcium and results in a negative calcium balance, which may contribute to the development of bone metabolic disorder in rats. On the other hand, 75% proximal small bowel resection causes no obvious metabolic bone disorders in rats, possibly because of the adaptation by the remaining part of the intestine.

The effects of new cytochalasins from Phomopsis sp. and the derivatives on cellular structure and actin polymerization

The effects of ten 10-phenyl-[11]cytochalasins produced by Phomopsis sp. including novel compounds having 5,7- or 6,7-glycol structures and their derivatives, on the cell morphology and actin distribution in C3H-2K cells, as well as on lymphocyte capping and actin polymerization, were examined. The structure-activity relationship reported in the previous papers has been confirmed. The novel glycol type compounds showed little or no activity, suggesting the importance of the perhydroisoindol-1-one nucleus for the manifestation of the cytochalasin actions.

Neutrophil-derived epoxide, 9,10-epoxy-12-octadecenoate, induces pulmonary edema

We have observed that neutrophils biosynthesize linoleate epoxide, 9,10-epoxy-12-octadecenoate, and have named it leukotoxin because of its cytotoxic effect. In this experiment, the effect of leukotoxin on the lung was investigated. Acute effect of leukotoxin: Using Wistar rats, leukotoxin (100 mumol/kg) was injected intravenously for the leukotoxin group, and linoleate (100 mumol/kg) for the linoleate group. Physiological saline was injected as the control. Ten min after injection, rats were divided into 3 groups: (1) lungs were isolated, and lung wet weight, and dry weight were measured; (2) lung lavages were performed, and albumin concentration and activity of angiotensin converting enzyme (ACE) were measured; (3) morphological changes were studied by light and electron microscope. After administration of leukotoxin, lung wet weight/body weight ratios and dry weight/wet weight ratios were increased. Albumin concentration and ACE activity in lung lavages were also increased. Pulmonary edema was also confirmed by light microscopic findings. Alveolar epithelial cell damage and endothelium damage were also observed. Linoleate had no significant effect on these biochemical parameters and morphological findings. Subacute effect of leukotoxin: Twelve hr after administration of leukotoxin (50 mumol/kg) or linoleate (50 mumol/kg), the same studies were performed as in the acute experiments. Immediately after administration of leukotoxin, no significant effect was observed. However, 12 hr later similar changes were observed as in the acute experiments. Linoleate did not show any significant effect 12 hr after injection. These results indicate that leukotoxin biosynthesized by neutrophils might be closely related to the genesis of inflammatory edema.

[Transfer of injected sulbactam/cefoperazone into burn blister fluid]

Transfer of sulbactam/cefoperazone (SBT/CPZ) into the burn blister fluid was studied in 10 burn patients after one shot intravenous injection of 50 mg/kg SBT/CPZ (CPZ 25 mg/kg, SBT 25 mg/kg). CPZ and SBT concentrations in serum and burn blister fluid were determined using bioassay and high performance liquid chromatography (HPLC). The concentration of CPZ in serum reached 109.5 +/- 9.2 micrograms/ml (mean +/- S.E.) at 0.25 hour after injection, and decreased to 6.8 +/- 2.3 micrograms/ml after 8 hours. The concentration of CPZ in burn blister fluid peaked at 4 hours and reached 28.2 +/- 8.0 micrograms/ml. The concentration of SBT in serum reached 75.7 +/- 8.3 micrograms/ml at 0.25 hour after injection, and decreased to 2.3 +/- 0.7 micrograms/ml after 8 hours. The peak concentration of SBT in burn blister fluid was 13.5 +/- 1.8 micrograms/ml at 3 hours. The data obtained were analysed pharmacokinetically. Cmax of CPZ and SBT levels in burn blister fluid were calculated to be 30.4 micrograms/ml and 13.6 micrograms/ml, respectively. The AUC0-8 hrs. (area under the burn blister fluid concentration of drug-time curve between 0 and 8 hours after injection), absorption rate constant (ka) and therapeutic AUC (AUC where drug concentrations were above minimum effective concentration) of CPZ were calculated to be 194.0 micrograms.hr/ml, 1.52 hr-1 and 97.1 micrograms.hr/ml (0.3-11.1 hours), respectively. The AUC0-8 hrs. and ka of SBT were also calculated as 68.3 micrograms.hr/ml and 0.62 hr-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimal conditions for injection of tobramycin and cefmenoxime into burn patients

The concentrations of tobramycin (TOB) or cefmenoxime (CMX) in serum and burn blister fluid of 51 burn patients (21 for TOB, 30 for CMX) after an i.v. or i.m. injection were determined to find the optimal administration of TOB (2 mg/kg) or CMX (50 mg/kg). Among the various protocols tested, we found from the values of tAUC for TOB that a bolus i.v. injection, or 1-h drip infusion, or i.m. injection are recommended for systemic sepsis, however, the 1-h drip infusion is strongly suggested for treating wound surface infection. It has also been found that with CMX a bolus i.v. injection with a long period of efficacy is recommended for treating systemic sepsis, while a 1-h drip infusion or bolus i.v. injection was the best method for treating wound-surface infection.

[Transfer of fosfomycin into human burn blister fluid and its pharmacokinetic analysis]

Fosfomycin (FOM) (50 mg/kg) was administered to burned patients by intravenous bolus injection. Burn blister fluid and serum were taken during 8 hours after injection, and concentrations of FOM in burn blister fluid and serum were determined by bioassay using Proteus sp. (MB-838) as the test organism. The serum concentrations of FOM were 257 +/- 34.6 micrograms/ml at 15 minutes, 222 +/- 34.8 micrograms/ml at 30 minutes, 166 +/- 34.6 micrograms/ml at 1 hour, 114 +/- 43.9 micrograms/ml at 2 hours, 79.5 +/- 34.9 micrograms/ml at 3 hours, 63 +/- 36.4 micrograms/ml at 4 hours, 44.3 +/- 27.6 micrograms/ml at 5 hours, 29.6 +/- 20.9 micrograms/ml at 6 hours and 17.9 +/- 12.8 micrograms/ml at 8 hours after the injection. FOM concentrations in burn blister fluid were 64.4 +/- 18.1 micrograms/ml at 30 minutes, 77 +/- 26.0 micrograms/ml at 1 hour, 71.6 +/- 24.7 micrograms/ml at 2 hours, 64.8 +/- 23.6 micrograms/ml at 3 hours, 43.2 +/- 8.8 micrograms/ml at 4 hours, 24.8 +/- 7.9 micrograms/ml at 6 hours and 17.9 +/- 10.5 micrograms/ml at 8 hours after the injection. The obtained data were analysed pharmacokinetically. The serum levels were analysed by a two-compartment model, and the transfer of FOM into burn blister was analysed by a modified deconvolution method. In results, Tmax and Cmax of FOM levels in burn blister fluid were calculated as 1.3 hours and 80.9 micrograms/ml, respectively. The transfer rate constant of FOM from serum to burn blister fluid (K1) and that from burn blister fluid to serum (K2) were calculated as 0.612 hr-1 and 1.10 hr-1, respectively.

Isolation and characterization of type V collagen from human post-burn granulation tissues

Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of pepsin-solubilized collagens from post-burn granulation tissues revealed that type V collagen consisted of 3 alpha chains: alpha 1(V), alpha 2(V), and alpha 3(V). The mean value (0.12 +/- 0.01 SD) of the type V/type I ratio in the granulation tissues was significantly higher (p less than 0.001) than that (0.03 +/- 0.01 SD) of the ratio in normal skin. The average ratio of alpha 1(V):alpha 2(V):alpha 3(V) of type V collagen purified from the granulation tissues was determined to be about 5:3:1. SDS-polyacrylamide gel electrophoresis patterns of 3 alpha chains were not affected in the presence or absence of 2-mercaptoethanol. Purified type V collagen was degraded by bacterial collagenase, but remained intact after tadpole collagenase digestion, in contrast to type I and type III collagens. Amino acid analyses of each alpha chain separated on SDS-gel electrophoresis of type V collagen revealed that all 3 alpha chains of type V collagen were poor in alanine, rich in hydroxylysine, and had high ratios of hydroxylysine/lysine, which are typical features of type V collagen. The purified type V collagen was further fractionated by ammonium sulfate into 2 molecular species, [alpha 1(V)]2 alpha 2(V) and alpha 1(V)alpha 2(V)alpha 3(V). Our data demonstrate that type V collagen in preparations from human post-burn granulation tissues consists of 3 alpha chains and can be resolved into 2 distinct heterotrimers.

Uterine tumor resembling ovarian sex-cord tumor with osteoid metaplasia

A rare uterine tumor showing sex-cord-like differentiation and marked osteoid metaplasia was found in a 33-year-old female. The tumor, occupying the uterine fundus, was multilobular, fleshy, and yellowish white, with punctations and poorly defined tumor margins into the subserosa. The tumor nodules were mostly composed of small, round, rather regular neoplastic cells with scanty cytoplasm and prominent nuclei. Epithelioid neoplastic cells with striking ovarian sex-cord-like arrangement, surrounded by fibrous tissue, were noticed. Polygonal neoplastic cells with marked osteoid metaplasia were also detected. The authors introduce an infrequent variant of uterine tumor resembling ovarian sex-cord tumor with osteoid metaplasia, probably of endometrial stromal cell origin. Because of deep myometrial infiltration without vascular invasion, malignant potential is considered. The patient is now alive without evidence of local recurrence or distant metastasis after abdominal total hysterectomy.

Studies on systemic absorption of tobramycin in polyethylene glycol ointment applied to wounds of burn patients

The penetration of tobramycin ointment (0.2 per cent) through human burn wounds was studied in two patients with superficial dermal burn (SDB) and deep dermal burn (DDB), two patients with DDB, one patient with full thickness burn (FB) and one patient with burn ulcer (BU). After application of the ointment, the absorption of tobramycin occurred promptly with a peak level at 2-6 h in the sera of patients with SDB + DDB and DDB only. In the BU patient it was found at 2 h; while in the FB, at 10-12 h. The excretion of tobramycin into the urine was also studied. The absorption rate constants (ka) of the two SDB + DDB patients were 0.31 and 0.74, of the two DDB patients, 0.079 and 0.18, and those of the DB and the BU patients, 0.053 and 0.95, respectively. The absorption ratios of tobramycin (amount excreted into the urine during 24 h/applied dose) were different, depending on the condition of the burn wound, and ranged from a low of 10.3 per cent (FB) to a high of 44.0 per cent (BU). These results show that the treatment of burn patients with tobramycin ointment to control burn wound infection should be carefully supervised, especially in the case of BU.

Bone disorders in spontaneously hypertensive rat

The bones of adult (26 weeks old) spontaneously hypertensive rats (SHR) were examined chemically and histologically by comparing them with those of the corresponding normotensive Wistar-Kyoto (WKY) rats. The mean cortical thickness, the mean ash weight per unit bone volume, and the ash as percentage of dry weight of femur were significantly lower in SHR than in WKY. Besides, the percent cortical area measured on tibial cross-section was also reduced in SHR compared with WKY. These findings strongly suggest that the development of osteoporotic bone disorders exists in adult spontaneously hypertensive rats.

Surgical treatment of skin depigmentation caused by burn injuries

Thin split-skin autografts of normal color were performed on depigmented skin caused by second- and third-degree burns in 32 patients. Repigmentation appeared in almost all the recipient areas soon after grafting and no depigmentation occurred again in the treated area.

[Transfer of latamoxef into human burn blister fluid and its pharmacokinetic analysis]

Latamoxef (LMOX) (50 mg/kg) was administrated intravenously to burned patients over 1 hour period. Burn blister fluid and serum were taken during 8 hours after injection, and concentrations of LMOX in burn blister fluid and serum were determined by bioassay using E. coli as a test organism. The serum concentrations of LMOX were 170.8 +/- 30.6 micrograms/ml at 30 minutes, 227.0 +/- 19.8 micrograms/ml at 1 hour, 90.3 +/- 21.4 micrograms/ml at 2 hours, 52.9 +/- 14.6 micrograms/ml at 3 hours, 38.7 +/- 13.3 micrograms/ml at 4 hours, 25.1 +/- 8.1 micrograms/ml at 5 hours, 20.5 +/- 8.1 micrograms/ml at 6 hours, 13.0 +/- 5.5 micrograms/ml (mean +/- S.D., n = 5) at 8 hours after the injection. The LMOX concentrations in burn blister fluid were 36.9 +/- 32.8 micrograms/ml at 30 minutes, 77.5 +/- 42.2 micrograms/ml at 1 hour, 85.4 +/- 19.6 micrograms/ml at 2 hours, 76.4 +/- 18.5 micrograms/ml at 3 hours, 63.5 +/- 17.8 micrograms/ml at 4 hours, 54.9 +/- 17.1 micrograms/ml at 5 hours, 34.8 +/- 10.3 micrograms/ml at 6 hours, 25.2 +/- 4.8 micrograms/ml (mean +/- S.D., n = 7) at 8 hours after the injection. The data obtained were analysed pharmacokinetically. The serum levels were analysed by two-compartment model, and the LMOX levels in burn blister fluid were analysed by the model, in which blister was considered as a small part of the peripheral compartment. In results, Tmax and Cmax of LMOX levels in burn blister fluid were calculated as 1.81 hours and 90.6 micrograms/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)