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)

Serum lipid peroxide levels of patients suffering from thermal injury

Lipid peroxide levels and activities of various enzymes were examined in sera from five thermally injured patients. In all patients examined, serum lipid peroxide levels were increased in the early post-burn period, and thereafter activities of glutamate oxalacetate transaminase, glutamate pyruvate transaminase, alkaline phosphatase and lactate dehydrogenase in the sera became elevated in most patients. From these observations, it is considered that increased lipid peroxides in the bloodstream during the early post-burn period would cause damage to various organs, permitting the leakage of the enzymes into the blood. These results support the view that lipid peroxide may be regarded as a 'burn toxin'.

Basal cell epithelioma occurring in an epidermal nevus

An unusual case is presented of a thirty-year-old woman in whom basal cell epithelioma developed from a preexisting localized epidermal nevus in the scalp. The epidermal nevus was not associated with any abnormal pilosebaceous complexes.

The effect of some ointment bases on the systemic absorption of tobramycin from various wound surfaces of burned patients

Three kinds of 0.2 per cent tobramycin ointment were prepared with tobramycin and 3 ointment bases (cream, polyethylene glycol and hydrophilic petrolatum), and applied to the various wound surfaces of 5 burned patients. The systemic absorptions of tobramycin were compared with the values of the tentative AUC (area under the curve of tobramycin blood level, micrograms.h/ml.g) until 12 hours after the applications, by determining tobramycin level in blood. Similar values of AUC from the cream and polyethylene glycol ointments were obtained, while that of hydrophilic petrolatum ointment was very low. The systemic absorption of tobramycin from the polyethylene glycol ointment was studied when the ointment was applied to the wound surfaces of 7 patients with partial-thickness burn, 9 patients with full-thickness burn and 6 patients with burn ulcer. The mean values of the tentative AUC of patients with partial-thickness burn, full-thickness burn and burn ulcer were found to be 0.06, 0.03 and 0.15, respectively. These results showed that cream and polyethylene glycol bases should be used carefully as a vehicle of tobramycin ointments because of the rapid systemic absorption of tobramycin from human burn wounds, especially burn ulcer.

[Transfer of cefmenoxime to burn blister fluids]

Transfer of cefmenoxime (CMX) into the burn blister fluids was studied in 10 burned patients with 2 administrated doses (25, 50 mg/kg). CMX concentrations in serum and burn blister fluid after 1 hour intravenous drip infusion were measured using Proteus mirabilis ATCC 21100 as the test organism grown in the DST agar medium. In the case of CMX 25 mg/kg dose, the peak serum concentration was observed 61.5 micrograms/ml at 1 hour, while the peak burn blister fluid concentration was observed 15.2 micrograms/ml at 2 hours. Pharmacokinetic parameters of serum concentration calculated were 1.02 hours as half-life (beta) and 0.42 L/kg as distribution volume, respectively. In the case of CMX 50 mg/kg dose, the peak serum concentration was observed 122.0 micrograms/ml at 1 hour and the peak burn blister fluid concentration was observed 40.8 micrograms/ml at 2 hours. Pharmacokinetic parameters of serum concentration calculated were 1.27 hours as half-life (beta) and 0.55 L/kg as distribution volume. From this study, the dose dependency between 25 mg/kg dose and 50 mg/kg dose in serum and in burn blister fluid is recognized.

Mitochondria-toxic activity in burned human skin: relation to severity of burn and period after burn

Toxic activity in the extracts of burned human skins impairing respiratory control of rat-liver mitochondria was compared in terms of the severity of burn injury and period after burn. The toxic activity was detected in the extracts from skins of third-degree burn, but not in those from skins of deep-dermal burn or of burn ulcers, in the present experimental conditions. In the case of third-degree burn, the toxic activity was not evident during the first few days post burn, but was significantly increased after 10 days. The results of this study suggest the effective period for early therapeutic débridement of the necrotized tissues in the management of severely burned patients.

The effect of skin grafts on the ratio of collagen types in human post-burn wound tissues

Pepsin digests of human post-burn wound tissues grafted with autologous fresh skin showed a significantly lower ratio, 0.37 +/- 0.04 (mean +/- S.D.), of type III to type I collagen determined by interrupted gel electrophoresis than the ratio, 0.55 +/- 0.13, measured in ungrafted wound tissues (p less than 0.001). In wounds grafted with frozen skin there was no significant difference from ungrafted wounds, but a significantly higher ratio, 0.46 +/- 0.08, than that in wounds grafted with fresh skin (p less than 0.001). These results were consistent with the histological features of the wound tissues.

Suppression of spermatogenesis in patients with Behçet's disease treated with cyclophosphamide and colchicine

Reproductive function was studied in 31 adult male patients with Behçet's disease during treatment with cyclophosphamide and/or colchicine for 1 to 64 months. Semen was obtained from 27 patients. Azoospermia or severe oligospermia was found in 13 of 17 patients receiving cyclophosphamide with or without colchicine, whereas the sperm count was almost normal in six patients treated with colchicine alone and in four patients receiving neither drug (control patients). Blood samples were available for 31 patients. The mean follicle-stimulating hormone level among 12 cyclophosphamide-treated patients was significantly higher than that of 6 colchicine-treated patients and 6 control patients. These results indicate that cyclophosphamide impairs spermatogenesis in adult men, whereas colchicine does not.

Effects of combination treatment with vitamins E and C on chloasma and pigmented contact dermatitis. A double blind controlled clinical trial

A multi-clinical double-blind study on therapeutic effect of combination preparation of vitamins E and C was undertaken in comparison with single preparation of vitamin E and vitamin C in the treatment of chloasma or pigmented contact dermatitis (PCD). Combination treatment resulted in significantly better clinical improvement than vitamin C alone in both diseases. Objective data compiled from color difference measurements and color photographs revealed significantly better results with combination treatment in chloasma than vitamin C alone and, in PCD, than vitamin E or C alone. Differences in skin luminosity between hyperpigmented and normal areas significantly decreased in all three groups, with the combination group producing the most significant change. The total serum lipoperoxide level and its ratio to total serum lipids tended to decline in the combination group, and decreased significantly in vitamin E group. The sebum lipoperoxide level decreased significantly only in the combination group (EC).

Immobilization osteoporosis and active vitamin D: effect of active vitamin D analogs on the development of immobilization osteoporosis in rats

The therapeutic effects of vitamin D analogs, 1,24(R)-dihydroxycholecalciferol [1,24(R)-(OH)2D3], 1,24(S)-dihydroxycholecalciferol [1,24-(S)(OH)2D3], and 1,25-dihydroxycholecalciferol [1,25(OH)2D3] on immobilization osteoporosis were studied in rats. The right hind limb was immobilized through application of a plaster cast following the section of the sciatic nerve. The left hind limb was intact. Vitamin D analogs were orally administered for 6 weeks at dose levels of 0.02 and 0.10 micrograms/kg/day, respectively. The mean lengths of the immobilized femurs were not significantly different from those of the intact femurs in all the experimental groups. In the immobilized femur of animals treated with 1,24(R)(OH)2D3, 0.10 micrograms/kg, dry and ash weights were heavier and calcium and phosphorus contents greater than those in the nontreated group. Furthermore, the amount of calcified bone mass and the cortical thickness of the femurs of the immobilized limb in 1,24(OH)2D3-treated animals were greater than those in the nontreated animals. Treatment with 1,25(OH)2D3 at 0.10 micrograms/kg caused an increase of the bone mass in both immobilized and intact femurs when compared with those of the control group. It was concluded that the administration of 1,24(R)(OH)2D3 diminished the effect of immobilization in the development of osteoporosis without any side effects.

Effect of 1 alpha-hydroxyvitamin D3 in rats with experimental renal osteodystrophy

A model of experimental renal osteodystrophy was established in the rats with chronic renal failure induced by partial nephrectomy and therapeutic effects of 1 alpha-hydroxyvitamin D3 (1 alpha-OH-D3) were studied. Male Wistar rats weighing 180 g were 5/6 nephrectomized and fed a normal diet (Ca and P : 1%) for 6 months. After the surgery, serum creatinine levels increased 60% and thereafter continued to rise gradually with their growth for 4 to 5 months, followed by rapid increase. The serum phosphorus levels were also elevated concomitantly and the serum calcium concentrations were normal. Marked bone resorption accompanied with hypertrophy of parathyroid glands was observed by histological examinations (Tetrachrome-Fuchsin stain, contact microradiography and H-E stain). The bone resorption seemed to be due to secondary hyperparathyroidism. Treatment with 0.25 micrograms/kg/day p.o. of 1 alpha-OH-D3 for 10 days in the uremic state resulted in remarkable new bone formation which was confirmed by histological examinations. These results clearly demonstrated that the reduction of nephron mass play a critical clue of renal osteodystrophy and 1 alpha-OH-D3 appears to have a good potential for clinical use in patients with renal failure and metabolic bone diseases.

Changes in type of collagen during the development of human post-burn hypertrophic scars

Neutral-salt soluble collagen was relatively abundant in young post-burn hypertrophic scars. The content of insoluble collagen was fairly low in granulation tissues, whereas it gradually increased over 2 years and reached a significantly higher value than that in normal skins. Interrupted gel electrophoresis was carried out to estimate the relative proportions of type III and type I collagens in the pepsin digests of human normal skins and post-burn scars. Granulation tissues showed an abnormally higher ratio of type III to type I (0.37--0.72) than the mean value of normal skins (0.17 +/- 0.04 (S.D.)). The ratio gradually decreased to the normal range after 2 years or so.

Correlation between X-prolyl dipeptidyl-aminopeptidase and serum amine oxidase in serum of patients with post-burn keloids

Activities of X-prolyl dipeptidyl-aminopeptidase (EC 3.4.14.1) and amine oxidase (EC 1.4.3.6) in serum were assayed in two groups of patients, children two to nine years old and adults 23 to 60 years old, with hypertrophic scars after severe burn. The peptidase activity tended to be low initially for several months after the burn, but then returned to normal after six months. These changes were marked in the child group, less so in the adult group. Similar but less-pronounced changes were also observed in serum amino oxidase activity. The two serum enzyme activities showed a significant positive correlation (r = 0.668, p less than 0.001, n = 27) in the patients.

Correlation between X-prolyl dipeptidyl-aminopeptidase and serum amine oxidase in serum of patients with post-burn keloids

Activities of X-prolyl dipeptidyl-aminopeptidase (EC 3.4.14.1) and amine oxidase (EC 1.4.3.6) in serum were assayed in two groups of patients, children two to nine years old and adults 23 to 60 years old, with hypertrophic scars after severe burn. The peptidase activity tended to be low initially for several months after the burn, but then returned to normal after six months. These changes were marked in the child group, less so in the adult group. Similar but less-pronounced changes were also observed in serum amino oxidase activity. The two serum enzyme activities showed a significant positive correlation (r = 0.668, p less than 0.001, n = 27) in the patients.

The eighth Frederick H. Verhoeff Lecture. presented by saiichi mishima, MD Behçet's disease in Japan: ophthalmologic aspects

The problems of Behçet's disease in Japan have been reviewed with particular emphasis on the ophthalmologic aspects: the historical background for the Japanese works, diagnostic critieria, epidemiology, some statistics, ocular symptomatology, ocular histopathology, etiology, pathophysiology, and treatment. Behçet's disease is the most frequent entity in endogenous uveitis in Japan. Patients are found throughout the country, and the prevalence rate averages seven to eight per 100,000 population: the rate is higher in the northern than in the southern districts. The diagnosis is made on the basis of a combination of clinical symptoms that are divided into the major and minor criteria symptoms. The major criteria comprise the ocular involvement, aphthous ulcers of the oral mucous membrane, genital ulcers, and skin lesions. These symptoms recur often as attacks and the disease follows a chronic course. The ocular involvement is found in 83% to 95% in males and 67% to 73% in females; the male to female ratio in the number of patients is 1.78. Both into the anterior segment type and the fundus and panophthalmic types. The anterior segment type shows serous iridocyclitis with the classic type of hypopyon appearing in about 12% of the attacks. This type is found in about 20%, more often in females than in males, and the visual prognosis is more favorable than in the fundus and panophthalmic types. In the latter two types, attacks of retinal angitis resulting in intensive retinal edema, yellowish-white exudate, and hemorrhages recur particularly in the macular region, and the visual prognosis is poor. More than 50% of male patients lose visual acuity to less than 0.1 in five years, but this is the case in only 10% of female patients. Consequently, Behçet's disease is the cause of blindness in about 12% of acquired blindness in adults. The ocular histopathology during the attack is characterized by severe angitis with intensive infiltration of neutrophil leucocytes largely in the uveal tract and the retina; the latter is severely affected and loss of visual cells and other neural elements results. The etiology of this disease still remains unknown but genetic predisposition is suggested since this disease is strongly linked with HL-A-B5. Environmental factors are also considered. Various abnormalities are found in the blood chemistry, blood cells (particularly in neutrophil leucocytes), immunologic mechanism, fibrinolytic and blood clotting system, and hormonal system. Chemotractic factors are found in the aqueous humor. These changes are particulary enhanced just before and during the ocular attacks. Systemic corticosteroids are deleterious to the visual prognosis, but cyclophosphamide and colchicine appear to suppress attacks and help patients maintain the visual acuity. However, these drugs are toxic, particulary to the reproductive organs, and the patients must be informed of this side effect and be allowed to make a decision before they are used.