Zinc l-pyrrolidone carboxylate inhibits the UVA-induced production of matrix metalloproteinase-1 by in vitro cultured skin fibroblasts, whereas it enhances their collagen synthesis.

Reduced collagen matrix in the dermis constitutes one of the characteristic features of chronologically aged skin, which is further enhanced on the sun-exposed portions of the body by chronic ultraviolet light (UV) irradiation, inducing the unique changes associated with skin photoageing. The zinc salt of l-pyrrolidone carboxylate (Zinc PCA) has long been used as a cosmetic ingredient, because of its astringent and anti-microbial properties. In the present study, by employing cultured normal human dermal fibroblasts, we found that Zinc PCA suppressed UVA-induced activation of activator protein-1 (AP-1) and reduced matrix metalloproteinase-1 production in these cells, which is thought to be involved in collagen degradation in photoaged skin. Moreover, Zinc PCA treatment of the cells increased the expression of an ascorbic acid transporter mRNA, SVCT2, but not SVCT1, resulting in the enhanced production of type I collagen. Based on these in vitro findings, we consider Zinc PCA to be a promising candidate for an anti-skin ageing agent.

Chain ordering of Stratum corneum lipids investigated by EPR slow-tumbling simulation.

We investigated the chain ordering of the lipid bilayer of Stratum corneum (SC) using an electron paramagnetic resonance (EPR) spin probe method in conjunction with slow-tumbling simulation. The ordering of SC lipids was evaluated by analysis of the signals of 5-doxylstearic acid (5-DSA) spin probe incorporated into the lamellar lipids. The result obtained with the conventional method of calculating the order parameter using hyperfine values was 0.80. The value of the order parameter obtained by spectral simulation was 0.73. It was found that the conventional method of calculating the chain ordering using hyperfine values could not differentiate subtle EPR spectral changes. However, EPR slow-tumbling simulation can differentiate such subtle spectral changes. Thus, the present EPR investigation suggests that simulation provides more detail about the structure of the lipid bilayer than the conventional method.

[Anesthetic management of a patient with hypohidrotic ectodermal dysplasia].

We anesthetized a 10-year-old girl with hypohidrotic ectodermal dysplasia for an ophthalmic surgery. Ectodermal dysplasia involves the abnormalities of ectodermal tissues and has a triad; hypohidrosis, a lack of teeth, and the scarcity of hair. Hyperthermia may occur due to the defect of sweat glands. Therefore, the body temperature must be monitored continuously. Respiratory tract infection occurs frequently due to the absence of seromucosal glands. We recommend humidifying the inspired gases during the operation. Tracheal intubation may be difficult because of maxillary and/or mandibular abnormalities. We conclude that the particular care should be taken such as the management of the body temperature, preparation for the difficult airway and the humidification of respiratory tract.

Interlaboratory validation of the In Vitro eye irritation tests for cosmetic ingredients (7) evaluation of cytotoxicity test by CornePack((R)).

The cytotoxicity test of neutral red (NR) uptake in normal rabbit corneal epithelial cells (CornePack((R))) was validated as an alternative method to the Draize rabbit eye irritation test (Draize test). We tested 38 cosmetic ingredients as well as isotonic sodium chloride solution in three phases of the validation study. The test procedures were controlled among participating laboratories under a common standard operating procedure (SOP). The concentration of test substances that showed a 50% reduction in NR uptake relative compared with controls (median NR uptake concentration: NR(50), mug/ml) was determined and compared with in vivo Draize scores. Six laboratories participated in the first phase of the validation study, seven in the second, and five in the third. The average interlaboratory coefficient of variation (CV) was 32.9%. The correlation and rank correlation coefficients between the maximal average Draize total scores (MAS) and NR(50) were -0.583 and 0.587, respectively. When the anionic detergents were excluded from analysis, the correlation coefficient increased to -0.738. When the cut-off point for positive and negative irritation was set at MAS of 15 and the predictability of this method was assessed by liner regression line, six substances (two acids, two alkanolamines and two alcohols) were false negative. Through this project, it appeared that CornePack, supplied in kit form with frozen secondary cultured cell in serum-free medium, could provide an effective, highly sensitive and simple preliminary screen for determining the cytotoxicity of substances. These results suggested that CornePack might have the potential to predict the MAS if definite criteria can be established for the compounds to be applicable. However, it is important to understand the nature of CornePack responses since its NR(50) profile was quite different from other cytotoxicity assays.

Studies of aloe. VI. Cathartic effect of isobarbaloin.

The cathartic effect of isobarbaloin, a stereoisomer of barbaloin (compound principally responsible for the cathartic activity of Aloe), was examined in male rats by oral administration. Individual differences in sensitivity in the laxative activity of isobarbaloin and barbaloin was not found. The cathartic activity (ED50) of isobarbaloin in barbaloin positive rats was 19.2 mg/kg, nearly equal to that of barbaloin (19.5 mg/kg). Also, isobarbaloin administered orally was demonstrated to decompose to aloe-emodin-9-anthrone (active metabolite of barbaloin) as well as to barbaloin. Therefore, it is considered that the mechanism underlying the cathartic effect of isobarbaloin is the same as that of barbaloin.

[Delayed emergence from propofol, nitrous oxide and oxygen anesthesia--a case report].

We report a case of delayed recovery after the termination of propofol and nitrous oxide anesthesia. On the preoperative examination hepatic dysfunction (Indocyanine green (ICG) plasma retention rate at 15 minutes of 22%) was pointed out. Anesthesia was maintained with epidural block, nitrous oxide, oxygen and propofol. Average infusion rate of propofol was 5-6 mg.kg-1.h-1. Although at the end of the operation, the propofol infusion and nitrous oxide were stopped simultaneously, 59 minutes were necessary before the emergence from anesthesia. We consider that an average infusion rate of propofol should be decelerated in a case of ICG clearance time elongation.

[Falls in PaO2 owing to prostaglandin E1 infusion in an obese patient undergoing laparoscopic cholecystectomy--detection by intra-arterial blood gas monitoring].

We monitored the changes of arterial blood gas tensions using a continuous blood gas monitor (Paratrend-7) in an obese patient who underwent laparoscopic cholecystectomy. We could observe continuous changes in PaO2 caused by prostaglandin E1 (PGE1) infusion. Suppression in hypoxic pulmonary vasoconstriction due to PGE1 would lead to falls in PaO2. Intra-arterial blood gas monitoring is quite useful in such a situation in which large .VA/.Q changes are expected due to infusion of PGE1 in an obese patient with high intra-abdominal pressure.

[Marked ST segment elevation in ECG during fiberscope-guided nasotracheal intubation in a patient with tetanus].

A patient with tetanus showed marked ST segment elevation in ECG during fiberscope-guided nasotracheal intubation. Coronary artery spasm could have been induced probably by tetanospasmin and this would lead to transmural ischemia during procedure. Pretreatment with anti-hypertensive agents such as calcium antagonist as well as sedatives are mandatory even when endotracheal intubation without laryngoscope is scheduled in this disease.

[Anesthetic management of a patient with urticaria pigmentosa].

Urticaria pigmentosa is a usually a benign and asymptomatic cutaneous variant of mastocytosis, which is a relatively rare disorder characterized by abnormal aggregates of mast cells in the dermis. These aggregations, if present, can abruptly release vasoactive mediators such as histamine, heparin, and prostaglandins under some physical stresses and may produce flushing, hypotension, syncope, shock, etc. One of the interesting aspects to an anesthesiologist is the effect of drugs administered perioperatively on mast cell degranulation. We report an infant case of urticaria pigmentosa and discuss the anesthetic significance especially of mastocytosis during anesthesia and surgery.

Mechanism of caffeine modulation of the antitumor activity of adriamycin.

We examined the effects of a combination of adriamycin (ADR) and caffeine on DNA and protein biosynthesis and on the activities of DNA polymerase alpha and beta in normal and tumor tissue. The decrease in DNA and protein biosynthesis in tumor produced by caffeine combined with ADR were 2.5 and 2.4 times greater, respectively, compared with ADR alone. The combination of caffeine and ADR enhanced the decrease in DNA polymerases activities in the tumor which was induced by ADR, the decreases being 1.8 and 1.6 times greater, respectively, than that of ADR alone. In contrast, these ADR-induced changes in normal tissues were not enhanced by the combination with caffeine. The combination with caffeine had no effect on ADR concentration in normal tissues, but in the tumor, it increased the ADR concentration to 2.1 times that of ADR alone. In vitro, ADR efflux from Ehrlich ascites carcinoma cells was significantly inhibited by exposure to caffeine. These findings indicate that the effect of caffeine on ADR concentration in the cell plays an important role in the mechanism by which caffeine enhances ADR antitumor activity.

Caffeine enhances adriamycin antitumor activity in Ehrlich ascites carcinoma-bearing mice.

We examined whether caffeine enhances the antitumor activity of adriamycin (ADR), in terms of prolonging survival in Ehrlich ascites carcinoma(ascites-type)-bearing mice. After administration of ADR at a dose of 0.5 mg/kg/d for 5d together with caffeine (100 mg/kg/d x 5 d), the survival period was increased by 39%. However, caffeine had little effect on this ADR induced-prolongation of survival following administration of ADR at 2.0 mg/kg/d for 4 d. Although a significant increase in ADR concentration in the ascites tumor was seen after administration of ADR at a dose of 0.5 mg/kg, caffeine failed to increase ADR concentration in the ascites tumor after administration of ADR at a dose of 2.0 mg/kg. The effect of caffeine thus appears to be due to its effect on the tumor distribution of ADR.

Transient induction of fatty acid synthase in rat liver after removal of a peroxisome proliferator.

Removal of a peroxisome proliferator from the diet triggered the degradation of peroxisomes and induced the transient expression of a 220 kDa soluble protein in rat liver. The 220 kDa protein was purified by conventional methods and analyzed by amino acid sequencing. A total of 99 amino acid residues in 4 lysylendopeptidase-digested peptides completely matched those in rat fatty acid synthase. The transient induction of fatty acid synthase mRNA during peroxisome degradation was confirmed by Northern blotting.

Protection against cisplatin-induced nephrotoxicity in the rat by inducers and an inhibitor of glutathione S-transferase.

In an attempt to decrease cisplatin-induced nephrotoxicity, glutathione S-transferase (GST) inducers and a GST inhibitor were combined with cisplatin and administered to rats. t-Stilbene oxide (t-SO) and propylthiouracil (PTU) were the GST inducers, and ketoprofen was the GST inhibitor. Combinations of these GST inducers and the inhibitor with cisplatin decreased cisplatin-induced nephrotoxicity. The drug combinations with cisplatin inhibited the cisplatin-induced increase in urinary total GST activity. The combination of t-SO with cisplatin increased total GST activity in the kidney, compared to levels in the cisplatin only group. The t-SO combination recovered the cisplatin alone-induced decrease in GST-alpha activity to control levels. However, glutathione peroxidase (GSHpx) activity after the t-SO combination was ever further reduced compared to the cisplatin alone-induced decrease. The combination of PTU, with cisplatin increased total GST, GST-alpha and GSHpx activity, compared to the cisplatin alone group. However, PTU severely decreased the glutathione (GSH) level. The combination of ketoprofen with cisplatin normalized GST-mu and -alpha activity, and elevated the cisplatin-induced decrease of GSHpx activity and GSH. These findings suggest that ketoprofen decreases cisplatin-induced nephrotoxicity.

[Studies on the pharmacodynamics of ginsenoside-Rg1, -Rb1 and -Rb2 in rats].

The pharmacodynamics of ginsenoside-Rg1 (Rg1), -Rb1 (Rb1) and -Rb2 (Rb2) in rats were studied. In these studies, obvious differences were found in their pharmacodynamics. That is, Rg1 was easily hydrated to the same prospogenins in both rat stomach and 0.1 N HCl solution, but Rb1 and Rb2 were little decomposed (metabolised) in rat stomach and a small quantity of their hydroperoxide derivatives were found, but they were easily hydrated to their prosapogenins by 0.1 N HCl. These ginsenosides were decomposed (metabolised) to several prosapogenins by enteric bacteria and enteric enzymes. The modes of their decomposition (metabolism) were respectively different. In particular, the terminal sugar moiety at the C-20 hydroxy group was noted to affect the rates of their decomposition. The amount of Rg1 and Rb1 absorbed from the gastrointestinal tract of rat were 1.9% and 0.1% of the dose, respectively. And that of Rb2 was determined to be 3.7% of the dose by using 3H-labeled Rb2. Rg1 was excreted into the urine and bile in a 2:5 ratio. Rb1 and Rb2 were mainly excreted into the urine.

Studies of aloe. V. Mechanism of cathartic effect. (4).

Aloe-emodin-9-anthrone(AE-anthrone), produced from barbaloin in the rat large intestine, caused not only an increase in the intestinal water content but also stimulated mucus secretion. This might play an important role in the occurrence of diarrhea. It was demonstrated that the amount of AE-anthrone produced in the rat large intestine(maximal amount: 568 micrograms/rat at 4 h after injection) was enough to cause both of these effects, which were observed following intracecal administration of barbaloin (31.1 mg/kg). These results together with our previous data, which showed a relationship between increase in the intestinal water content and the stimulation of peristalsis, confirm that AE-anthrone is the principal agent responsible for the cathartic effect of barbaloin. We also propose that the increase in water content is a more important factor than stimulation of peristalsis in the induction of diarrhea by barbaloin.

Studies of aloe. IV. Mechanism of cathartic effect. (3).

Charcoal transport, as an indicator of the degree of peristalsis, and water content in the large intestine after the intracaecal administration of barbaloin, were measured simultaneously in the same rat. Charcoal transport was significantly accelerated at both 3.5 and 6.5 h after the administration of barbaloin. At 6.5 h, diarrhea instead of normal faeces was observed. Moreover, at 1 h before the acceleration of charcoal transport, a marked increase in the relative water content of the large intestine was observed. It appears that the increase in water content of the large intestine induced by barbaloin precedes the stimulation of peristalsis, attended by diarrhea. Therefore, it is suggested that the increase in water content is a more important factor than the stimulation of peristalsis in the diarrhea induced by barbaloin.

Role of glutathione S-transferase isoenzymes in cisplatin-induced nephrotoxicity in the rat.

cis-Diamminedichloroplatinum(II) (cisplatin) is an effective antitumor agent but causes dose-dependent nephrotoxicity. We examined the changes of glutathione S-transferase (GST) isoenzymes in the rat kidney after cisplatin administration. Renal GST-alpha activity was decreased to 33.4% of the control level and GST-mu activity was increased 1.9-fold after cisplatin administration. These results were confirmed by affinity chromatography of rat renal GST isoenzymes. Our results showed that changes of GST isoenzymes were associated with cisplatin-induced nephrotoxicity. We examined whether GST isoenzymes leaked into the urine by proximal tubular damage could provide a useful marker of cisplatin-induced nephrotoxicity. The total GST and GST-mu activities in urine correlated well with the changes of BUN, which closely parallels the course of nephrotoxicity after cisplatin administration. Our results indicated that renal GST-mu activity was decreased by cisplatin, and although GST-mu activity increased as a compensation mechanism, nephrotoxicity still appeared because of differences in substrate specificity between these two isoenzymes.

Increase in the amount of elongation factor 2 in rat liver by peroxisome proliferators.

The changes in protein phosphorylation during induction and deinduction of peroxisome proliferation in rat liver by three types of proliferators were studied by in vitro phosphorylation assay. Among the variously phosphorylated proteins, an increase during induction and a decrease during deinduction in phosphorylation of P100, a cytosolic protein having a molecular weight of 100 kDa, was most remarkable. The time course of enhancement of phosphorylation by the administration of the proliferators, however, was not parallel with proliferation of peroxisome but with increase in the liver DNA content. Amino acid sequencing of the protein indicated the identity of its N-terminal 17 amino acid residues with those of elongation factor 2 (EF2). Increase in the amount of EF2 by peroxisome proliferators was confirmed by immunoblotting and this was almost parallel with peroxisome proliferation, suggesting that both increase in the amount of EF2 and some changes in phosphorylation activities account for a large increase in in vitro phosphorylation of EF2 by the administration of peroxisome proliferators.

Rat selection test with respect to laxative activity induced by barbaloin.

As individual differences in sensitivity in the laxative activity of barbaloin were observed in rats, a selection test for barbaloin (31.1 mg/kg, p.o.) was carried out between 1989 and 1991. The annual percentages of rats exhibiting a reaction positive to barbaloin were almost constant (about 57%). We propose that rats positive to barbaloin should be selected for studies on the laxative effect of barbaloin.