Dowling-Degos disease (reticulate pigmented anomaly of the flexures): a clinical and histopathologic study of 6 cases

BACKGROUND

Few case series describing Dowling-Degos disease (DDD) have been reported.

OBJECTIVE

Our purpose was to review the clinical and histopathologic findings in DDD.

METHODS

We reviewed the clinical and histopathologic findings in 6 patients with DDD who were evaluated at the Mayo Clinic.

RESULTS

In addition to the typical flexural pigmented reticulate macules, comedo-like lesions on the back or neck or both were present in all 6 patients; 3 patients had pitted perioral scars, and 3 patients reported pruritus of affected flexural areas. Five patients were female, 5 patients had onset of pigmentation before age 24 years, and 3 patients had a family history of DDD. One patient had additional pigmentation involving the dorsum of the hands and proximal nailfolds and fingernail dystrophy. Histopathologically, pigmented rete ridge elongation with thinning of suprapapillary epithelium, dermal melanosis, and perivascular lymphohistiocytic infiltration were consistently observed.

CONCLUSION

Comedo-like lesions, pruritus, and pitted perioral scars are common features in association with the reticulate flexural pigmentation. Histopathologically, pigmented rete ridge elongation and dermal melanosis of biopsy specimens from flexural areas are seen.

Antioxidative flavonoids from the leaves of Morus alba

Nine flavonoids (1-9) were isolated from the leaves of Morus alba (Moraceae). The structures of compounds were determined to be kaempferol-3-O-beta-D-glucopyranoside (astragalin, 1) kaempferol-3-O-(6"-O-acetyl)-beta-D-glucopyranoside (2), quercetin-3-O-(6"-O-acetyl)-beta-D-glucopyranoside (3), quercetin-3-O-beta-D-glucopyranoside (4), kaempferol-3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (5), quercetin-3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (rutin, 6), quercetin-3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (7), quercetin-3,7-di-O-beta-D-glucopyranoside (8) and quercetin (9) on the basis of spectroscopic and chemical studies. Compounds 7 and 9 exhibited significant radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical.

Dipyridamole modulated Tc-99m sestamibi lung SPECT in small cell lung cancer

PURPOSE

In this study, the authors wanted to determine whether dipyridamole-modulated MIBI (dipyridamole-MIBI) could enhance the prediction of the response to chemotherapy in patients with small cell lung cancer.

METHODS

Twenty-seven patients with biopsy-proved small cell lung cancer (25 men, 2 women; mean age, 61 +/- 7 years) underwent dipyridamole-MIBI SPECT 3 to 7 days before starting chemotherapy (80 mg/m2 etoposide and 80 mg/m2 cisplatin every 3 or 4 weeks for at least two cycles). Tomographic images before and after dipyridamole (0.84 mg/kg) were acquired 1 hour after injection of 370 (10 mCi) and 1,110 (30 mCi) MBq MIBI, respectively. The response to chemotherapy was grouped as specified as complete response (CR), partial (PR), no change (NC), or progressive disease (PD), according to the change in tumor size on chest roentgenography and CT. Patients showing CR and PR were classified as responders, and those who showed NC and PD were considered nonresponders.

RESULTS

Among the 27 patients, 22 were responders (3 CR, 19 PR) and 5 were nonresponders (3 NC, 2 PD). The tumor-to-normal lung ratio (T:NL) of responders was significantly higher than that of nonresponders. The diagnostic accuracy of the T:NL ratio to differentiate responders and nonresponders was 33.3%, with a cutoff value of 2.5, which was significantly improved to 77.8% when an increased T:NL ratio after dipyridamole was assigned to a nonresponder. Furthermore, all patients with CR showed diminished T:NL ratios after dipyridamole, and all patients with NR showed an increased T:NL ratio after dipyridamole.

CONCLUSION

Dipyridamole-MIBI SPECT could enhance the prediction of response to chemotherapy in patients with small cell lung cancer.

Non-ginsenoside nicotinic activity in ginseng species

Amongst the many different therapeutic applications of ginseng are beneficial effects on age-related cognitive impairments. Ageing in the brain is associated with a loss of nicotinic receptor binding and receptor stimulation increases binding. Stimulation of the CNS (central nervous system) nicotinic receptor is considered to be beneficial in relation to symptomatic treatment and neuroprotection in age-associated cognitive disorders which involve a further receptor loss. We assessed Panax ginseng, Panax quinquefolium and several chemical constituents of these plants for nicotinic activity based on displacement of 3H-(-)nicotine from human brain cerebral cortex membranes in vitro. Dose-dependent displacement was evident in crude ethanol extracts of Panax ginseng and Panax quinquefolium. Assay of an extract of Panax ginseng showed the plant to have affinity for both the nicotinic receptor, and to a lesser extent the muscarinic receptor (IC50 2.12 mg/mL and 5.25 mg/mL respectively). Activity was largely conserved after the extraction of choline and other water soluble quaternary ammonium compounds (QAC), indicating that the activity of the plant extracts was not due to choline. Displacement binding assay of some purified chemical constituents, including a number of ginsenosides, showed that these were not primarily responsible for Panax activity. The active chemical constituent has yet to be identified, but the demonstrated nicotinic activity of ginseng warrants further investigation with reference to therapeutic activity in age-related conditions such as dementia.

A 1.4-Mb high-resolution physical map and contig of chromosome segment 11p15.5 and genes in the LOH11A metastasis suppressor region

The centromeric part of chromosome segment 11p15.5 contains a region of frequent allele loss in many adult solid malignancies. This region, called LOH11A, is lost in 75% of lung cancers and is thought to contain a gene that may function as a metastasis suppressor. Genetic complementation studies have shown suppression of the malignant phenotype including reduction of metastasis formation. We constructed a high-resolution physical map and contig over 1.4 Mb that includes the beta-hemoglobin gene cluster and the gene for the large subunit of ribonucleotide reductase (RRM1). Through sequencing and computerized analysis, we determined that this region contains an unusually large number of transposable elements, which suggests that double-stranded DNA breaks occur frequently here. Twenty-two putative genes were identified. Because of its location at the site of maximal allele loss in the 650-kb LOH11A region and previous functional studies, RRM1 is the most likely candidate gene with metastasis suppressor function. The malignant phenotype, in this case, results from a relative loss of function rather than a complete loss.

Effect of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'- dicarboxylate (DDB) on chemical-induced liver injury

The effects of orally administered dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene-dioxybiphenyl-2,2'-d icarboxylate (DDB) on the hepatotoxicity induced by carbon tetrachloride, acetaminophen or ethanol were investigated in rats and mice. Either single or repeated DDB pretreatment (50 or 200 mg/kg) did not alter the hepatotoxicity induced by carbon tetrachloride (0.2 or 1.0 ml/kg, i.p.) in female rats as indicated by increases in the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) in serum. The hepatotoxicity of acetaminophen (350 mg/kg, i.p.) was also unaffected in male mice pretreated with DDB (50 mg/kg/d) for a week. However, DDB administration (50 mg/kg/d for 7 d) decreased the hepatic fatty degeneration induced by repeated ethanol treatment (0.75 g/kg, i.p., x2 times a day for a week) in rats as shown by the accumulation of triglycerides and cholesterol in the liver. Malondialdehyde (MDA) formation in liver homogenates was inhibited by DDB treatment. The significance of the action of DDB on alcoholic fatty liver generation in clinical settings is discussed.

Ca2+ influx through carbachol-activated non-selective cation channels in guinea-pig gastric myocytes

1. Ca2+ microfluorometry (100 microM K5 fura-2) and the voltage-clamp technique were combined to study the effect of carbachol (CCh, 50 microM) in inducing currents (ICCh) through non-selective cation channels (NSCCCh) and increments in global cytosolic Ca2+ concentration (Delta[Ca2+]c). 2. In Na+-containing bath solution, ICCh fell from an initial phasic to a subsequent small (5 %) tonic component; Delta[Ca2+]c fell to zero. Tonic ICCh and [Ca2+]c became prominent after substitution of extracellular 140 mM Na+ by 140 mM Cs+. Tonic ICCh and Delta[Ca2+]c were insensitive to intracellular heparin (3 mg ml-1) and ryanodine (4 microM), i.e. they did not depend on Ca2+ release from sarcoplasmic reticulum (SR). 3. Single channel currents of NSCCCh could be resolved in whole-cell recordings. Substitution of Na+ by Cs+ increased NSCCCh activity by one order of magnitude and slope conductance from 22 to 30 pS. Extracellular quinidine (3 microM) reversibly blocked the NSCCCh activity. 4. Both tonic ICCh and tonic Delta[Ca2+]c (a) followed a similar time course of activation, desensitization and facilitation, (b) were reversibly blocked by 3 microM quinidine, and (c) persisted upon block of SR Ca2+ release. 5. A Ca2+ fractional current of tonic ICCh (fCa) of 0.009 was calculated by comparing the ratio Delta[Ca2+]c (corrected for simultaneous Ca2+ redistribution) over ICCh with depolarization-induced *Delta[Ca2+]c (Delta[Ca2+]c calculated from ICa induced by a 400 ms depolarization from -60 to 0 mV at 2 mM [Ca2+]o, 145 mM [Cs+]o) over ICa. fCa was 0.023 at [Ca2+]o = 4 mM. 6. With 110 mM extracellular CaCl2 and 145 mM intracellular CsCl, ICCh reversed at +19.5 mV suggesting a permeability ratio PCa/PCs of 2.8. 7. We conclude that Ca2+ influx through NSCCCh under physiological [Ca2+]o could induce Delta[Ca2+]c. The fCa was, however, much smaller than the one calculated from the reversal potential.

Hepatoprotective activity of scopoletin, a constituent of Solanum lyratum

Scopoletin (7-hydroxy-6-methoxycoumarin), a coumarin, was isolated from the aerial part of Solanum lyratum Thunb. by the activity-guided fractionation employing carbon tetrachloride-intoxicated primary cultured rat hepatocytes as a screening system. Its hepatoprotective activity was first evaluated by measuring the release of glutamic pyruvic transaminase and sorbitol dehydrogenase from carbon tetrachloride-intoxicated rat hepatocytes into the culture medium. Scopoletin significantly reduced the releases of glutamic pyruvic transaminase and sorbitol dehydrogenase from the carbon tetrachloride-intoxicated primary cultured rat hepatocytes by 53% and 58%, respectively, from the toxicity in a dose-dependent manner over concentration ranges of 1 microM to 50 microM. Further studies revealed that at the concentration of 10 microM, scopoletin significantly preserved glutathione content by 50% and the activity of superoxide dismutase by 36% and also inhibited the production of malondialdehyde to the degree as seen in the control.

Rehabilitation of a triple amputee including a hip disarticulation

A multiple amputee more severe than a triple amputee is uncommon. There have been no reports on the rehabilitation outcome of a triple amputee, including hip disarticulation and transtibial amputation. The authors report the rehabilitation of a patient with left hip disarticulation, right trans-tibial amputation, and left trans-humeral amputation due to a train accident. He has successfully completed the rehabilitation programme and has become independent in prosthetic ambulation, activities of daily living, and driving.

Production of a hepatoprotective cerebroside from suspension cultures of Lycium chinense

Suspension cultures derived from Lycium chinense Miller seedlings produced significant amounts of a hepatoprotective cerebroside. Callus was induced from the stem of aseptic seedlings of L. chinense and maintained on MS solid media supplemented with 1.0 ppm 2,4-D and 0.1 ppm kinetin. Suspension cultures were established, and the cells were grown in the same liquid media in the dark. Lyophilized cells were extracted with a combined reagent of chloroform and methanol (2:1, v/v). An aqueous suspension of the evaporated cell extract was partitioned with chloroform, and the chloroform layer was subjected to silicic acid column chromatography followed by semi-preparative reverse phase C8 high pressure liquid chromatography. The purified compound showed hepatoprotective activity comparable to that shown by silymarin, and the structure was identified as 1-O-(β-D-glucopyranosyl)-(2S,3R,4E,8Z)-2-N-2'-hydroxy-(palmitoyl)-4,8-sphingadiene on the basis of spectral data. The content of the compound in cultured cell was tenfold higher than that of the fruit of L. chinense. The biosynthesis of the compound in cultured cell systems appears to parallel cell growth.

The interactive effect of Ras, HER2, P53 and Bcl-2 expression in predicting the survival of non-small cell lung cancer patients

In patients with non-small cell lung cancer (NSCLC), tumor expression of P21-Ras, HER2, P53, and Bcl-2 has been reported as independent predictors of prognosis. However, the prognostic information carried by these proteins has usually been determined separately, and their potential interaction has not been taken into account. We conducted immunostaining for P21-Ras, HER2, P53 and Bcl-2 on 238 cases of NSCLC in a Korean population with 203 squamous cell carcinomas, and 35 adenocarcinomas. P21-Ras, HER2, P53 or Bcl-2 was expressed at high levels in 54.6, 42.0, 18.1 and 71.8% of the NSCLC studied, respectively. A total of 59 tumors (24.8%) expressed only one protein, while 70 (29.4%) expressed two, 59 (24.8) expressed three, and 17 tumors (7.1%) expressed all four proteins. Univariate analysis testing the association of marker expression with survival found Bcl-2 expression to be significantly associated with a poor prognosis, as well as the co-expression of Bcl-2 + HER2, Bcl-2 + HER2 + P53, and Bcl-2 + HER2 + P53 + P21-ras with an increasing hazard ratio. By multivariate analysis controlling for age, tumor stage and tumor type, only the combination of Bcl-2 + HER2 expression was an independent marker of poor prognosis (hazard ratio = 1.91, P = 0.003). Thus, a prospective analysis of the co-expression of Bcl-2 + HER2 in NSCLC patients may identify patients with a poor prognosis who may benefit from more aggressive therapy.

Effect of post-induction nutrient feeding strategies on the production of bioadhesive protein in Escherichia coli

The effect of post-induction nutrient feeding strategies on the production of bioadhesive protein using an IPTG inducible expression system in Escherichia coli was investigated. Cells were cultured in an exponential fed-batch mode to the OD600 of ca. 100 (48 gDCW/L) prior to induction. Six different post-induction nutrient feeding strategies (pH-stat, exponential, constant and linear change in feeding rate with three different slopes) were then applied, and bioadhesive protein production was examined. It was found that post-induction cell growth was independent of nutrient feeding rate. However, bioadhesive protein production was significantly affected by post-induction feeding strategies. Linearly changing post-induction feeding rate with a suitable slope allowed production of bioadhesive protein up to 5.3 g/L, which was higher than that obtained by the other post-induction feeding strategies.

Spreading pattern of epidurally administered contrast medium in rabbits

BACKGROUND

The aim of this study was to examine the precise spreading pattern of epidurally administered contrast medium with small increments of injection volume for determining both the exact volume of the dose required and the site of epidural injection according to different target segments of the spinal cord in a rabbit epidural model.

METHOD

Following pentobarbital anesthesia, the epidural puncture was done surgically with a round-tipped blunt hook. The tip of the epidural catheter was located at either the mid-portion of T7 (T7 group, n = 7) or T12 (T12 group, n = 8). Injection of the contrast medium was started at 0.1 ml/kg and increased by 0.1 ml/kg up to a maximum of 0.6 ml/kg.

RESULTS

In both groups, the extent of spread increased continuously with increasing injected volume (T7 group: r2 = 0.91, P = 0.0001; T12 group: r2 = 0.86, P = 0.0001) and the total spread of contrast medium was similar. However, the spread was not linearly volume dependent. The total number of segments (y) through which the contrast medium spread during changes in its volume (x) in the T7 and T12 groups was calculated as y = 4.0 + 41.8x - 28.1x2 and y = 0.2 + 57.7x - 43.5x2, respectively. The contrast medium spread in both rostral and caudal directions, equally from the catheter tip in the T7 group, whereas it spread rostrally about twice as far as it spread caudally in the T12 group (P < 0.05).

CONCLUSION

In rabbits, it is recommended that at the lower thoracic or lumbar segments the tip of the epidural catheter should be located 1-3 segments below the target segment because of more rostral spread. In the case of mid-thoracic segments, however, placement at the target segment is recommended. In addition, a small titration of volume to achieve a particular range of epidural spread should be required.

Inhibition of nitric oxide synthesis by butanol fraction of the methanol extract of Ulmus davidiana in murine macrophages

Since there is increasing evidence that nitric oxide (NO) plays a crucial role in the pathogenesis of inflammatory diseases, this study was undertaken to address whether the methanol (MeOH) extract and its fractions of the bark of Ulmus davidiana Planch (Ulmaceae) could modulate the expression of inducible NO synthase (iNOS) in thioglycollate-elicited murine peritoneal macrophages and murine macrophage cell line, RAW264.7 cells. Stimulation of the peritoneal macrophages and RAW264.7 cells with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) resulted in increased production of NO in the medium. However, the butanol (BuOH) fraction of the MeOH extract of U. davidiana barks showed marked inhibition of NO synthesis in a dose-dependent manner. The inhibition of NO synthesis was reflected in the decreased amount of iNOS protein, as determined by Western blotting. The BuOH fraction did not affect the viability of RAW264.7 cells, as assessed by methylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT) assay; rather, it reduced endogenous NO-induced apoptotic cell death via inhibition of NO synthesis in RAW264.7 cells. On the other hand, the BuOH fraction showed no inhibitory effect on the synthesis of NO by RAW264.7 cells, when iNOS was already expressed by the stimulation with IFN-gamma and LPS. Collectively, these results demonstrate that the BuOH fraction inhibits NO synthesis by inhibition of the induction of iNOS in murine macrophages.

Blood sampling site-dependent plasma concentrations and hepatotoxic parameters in serum after intraperitoneal administration of acetaminophen to rats

Blood sampling site-dependent (the dorsal aorta, the jugular vein, and the retro-orbital sinus) plasma concentrations of acetaminophen and its glucuronide and sulfate conjugates, and acetaminophen-induced hepatotoxic parameters (such as ALT and SDH activity) in serum were evaluated after intraperitoneal administration of acetaminophen, 500 mg/kg body weight, to rats. The plasma concentrations and the resultant AUC0-12 h of acetaminophen, acetaminophen-glucuronide, and acetaminophen-sulfate were significantly higher when blood samples were collected from the retro-orbital sinus than those from the jugular vein. The serum ALT activity at 3 and 24 h after administration of acetaminophen were significantly higher when the blood samples were collected from the retro-orbital sinus than those from the dorsal aorta.

Ginsenosides Rb1 and Rg3 protect cultured rat cortical cells from glutamate-induced neurodegeneration

Certain natural products and Asian herbal remedies have been used in Asia to attenuate neurodegenerative diseases, including senile dementia. We have examined derivatives of several natural products for potential neuroprotective activity in an in vitro test system. In the present study, we assayed a number of compounds that were isolated from Panax ginseng C.A. Meyer (Araliaceae) for an ability to protect rat cortical cell cultures from the deleterious effects of the neurotoxicant, glutamate. We found that ginsenosides Rb1 and Rg3 significantly attenuated glutamate-induced neurotoxicity. Brief exposure of cultures to excess glutamate caused extensive neuronal death. Glutamate-induced neuronal cell damage was reduced significantly by pretreatment with Rb1 and Rg3. Ginsenosides Rb1 and Rg3 inhibited the overproduction of nitric oxide, which routinely follows glutamate neurotoxicity, and preserved the level of superoxide dismutase in glutamate-treated cells. Furthermore, in cultures treated with glutamate, these ginsenosides inhibited the formation of malondialdehyde, a compound that is produced during lipid peroxidation, and diminished the influx of calcium. These results show that ginsenosides Rb1 and Rg3 exerted significant neuroprotective effects on cultured cortical cells. Therefore, these compounds may be efficacious in protecting neurons from oxidative damage that is produced by exposure to excess glutamate.

Suppression of the carbachol-activated nonselective cationic current by antibody against alpha subunit of Go protein in guinea-pig gastric myocytes

In this study, we investigated which subtype of GTP-binding protein (G protein) is related to muscarinic activation of nonselective cation (NSC) channels in gastric smooth muscle. Inward cationic current was activated by the application of 50 microM carbachol (ICCh) at a holding potential of -60 mV with the same CsCl-rich solution in both pipette and bath. The same cationic current as ICCh was slowly activated by the dialysis of guanosine 5'-O-(3-thiotriphosphate) (GTP[gamma-S]) through the pipette. Since it is known that pertussis toxin pretreatment can block ICCh, antibodies (Abs) against Galpha,i (anti-Galpha,i) or Galpha,o (anti-Galpha,o) were tested. Activation of ICCh was blocked by the addition of anti-Galpha,o. However, anti-Galpha,i Abs had no significant effect on ICCh. The expression of Galpha,o in guinea-pig gastric smooth muscle was confirmed by Western immunoblot analysis. These results suggest that Go-type protein may mediate signals from the muscarinic receptor to NSC channel in guinea-pig gastric myocytes.

Relationship between global cytosolic Ca2+ concentration and Ca2+-activated K+ current in rabbit cerebral arterial myocyte

In smooth muscle cells, the sarcoplasmic reticulum (SR) has been identified as the primary storage site for intracellular Ca2+. The peripheral SR is in close proximity with plasma membrane to make a narrow subsarcolemmal space. In this study, we investigated the regulation of subsarcolemmal [Ca2+] ([Ca2+]sl) and global cytosolic [Ca2+] ([Ca2+]c) of rabbit arterial smooth muscle using whole cell patch clamp technique and microspectrofluorimetry. The Ca2+-activated K+ current (IK(Ca)) and the ratio of fura-2 fluorescence (R340/380) were considered to reflect the [Ca2+]sl and [Ca2+]c, respectively. At a holding potential of 0 mV, extracellular application of 10 mM caffeine, a well known Ca2+-releasing agent, induced transient increase of IK(Ca) and R340/380 (IK(Ca)-transient and R340/380-transient, respectively). The increase and decay of IK(Ca) transient was faster than R340/380-transient. By repetitive application of caffeine, when the refilling state of SR was supposed to be lower than the control condition, IK(Ca)-transient and R340/380 transient were suppressed to different levels; e.g. the second application 20 sec after the first could induce smaller IK(Ca) transient than R340/380-transient. Dissociation of IK(Ca)-transient and R340/380-transient was removed by sufficient (>3 min) washout of caffeine. Recovery from the dissociation was also dependent upon the membrane potential; faster recovery was observed at negative (-40 mV) holding potential than at depolarized (0 mV) condition. Dissociation of IK(Ca) from [Ca2+]c was also partially prevented by perfusion with Na+-free (replaced by NMDG+) extracellular solution. These results suggest that, 1) there is prominent spatial inhomogeneity of [Ca2+] in cerebral arterial myocyte, 2) [Ca2+]Sl is preferentially affected by the interference from nearby plasmalemmal Ca2+ regulation mechanism which is partly dependent upon extracellular Na+.

Effects of singly administered betaine on hepatotoxicity of chloroform in mice

Effects of a single dose of betaine on the chloroform-induced hepatotoxicity were examined in adult male ICR mice. Administration of betaine (1000 mg/kg, ip) 1 to 7 hr prior to a chloroform challenge (0.25 ml/kg, ip) resulted in remarkable enhancement of hepatotoxicity as indicated by increases in serum sorbitol dehydrogenase (SDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. The potentiation of hepatotoxicity was most significant when mice were treated with betaine 4 hr earlier than chloroform. However, a 24 hr prior administration of betaine protected the animals from induction of the chloroform hepatotoxicity. Thus, its effect appeared to be highly dependent on the time lapse from the betaine pretreatment to the challenge of mice with chloroform. Betaine treated either 4 or 24 hr prior to sacrifice did not alter the hepatic contents of cytochrome P-450, cytochrome b5, or NADPH cytochrome P-450 reductase activity. Accordingly the hepatic microsomal p-nitroanisole O-demethylase, aminopyrine N-demethylase, or p-nitrophenol hydroxylase activities were not influenced by the betaine pretreatment. Betaine was shown not to affect any of the enzyme activities associated with glutathione (GSH) conjugation reaction, such as glutathione S-transferases (GSTs), glutathione disulfide (GSSG) reductase and GSH peroxidase irrespective of the time of its administration. When betaine was administered to mice 2-6 hr prior to sacrifice, hepatic GSH level, but not plasma GSH, was decreased significantly. Enhancement of the chloroform hepatotoxicity by betaine correlated well with the reduction in hepatic GSH levels. Both hepatic and plasma GSH levels were elevated in mice 24 hr following the betaine treatment. The results suggest that betaine affects induction of the chloroform hepatotoxicity by modulating the availability of hepatic GSH, which appears to be associated with its role in the transsulfuration pathway in the liver.

Derivatives of the triazoloquinazoline adenosine antagonist (CGS 15943) having high potency at the human A2B and A3 receptor subtypes

The adenosine antagonist 9-chloro-2-(2-furanyl)[1,2,4]triazolo[1, 5-c]quinazolin-5-amine (CGS 15943) binds nonselectively to human A1, A2A, and A3 receptors with high affinity. Acylated derivatives and one alkyl derivative of the 5-amino group and other modifications were prepared in an effort to enhance A2B or A3 subtype potency. In general, distal modifications of the N5-substituent were highly modulatory to potency and selectivity at adenosine receptors, as determined in radioligand binding assays at rat brain A1 and A2A receptors and at recombinant human A3 receptors. In Chinese hamster ovary cells stably transfected with human A2B receptor cDNA, inhibition of agonist-induced cyclic AMP production was measured. An N5-(2-iodophenyl)acetyl derivative was highly selective for A2A receptors. An (R)-N5-alpha-methyl(phenylacetyl) derivative was the most potent derivative at A3 receptors, with a Ki value of 0.36 nM. A bulky N5-diphenylacetyl derivative, 13, displayed a Ki value of 0. 59 nM at human A3 receptors and was moderately selective for that subtype. Thus, a large, nondiscriminating hydrophobic region occurs in the A3 receptor in proximity to the N5-substituent. A series of straight-chain N5-aminoalkylacyl derivatives demonstrated that for A2B receptors the optimal chain length occurs with three methylene groups, i.e., the N5-gamma-aminobutyryl derivative 27 which had a pA2 value of 8.0 but was not selective for A2B receptors. At A1, A2A, and A3 receptors however the optimum occurs with four methylene groups. An N5-pivaloyl derivative, which was less potent than 27 at A1, A2A, and A3 receptors, retained moderate potency at A2B receptors. A molecular model of the 27-A2B receptor complex based on the structure of rhodopsin utilizing a "cross-docking" procedure was developed in order to visualize the environment of the ligand binding site.

In vitro platelet-activating factor receptor binding inhibitory activity of pinusolide derivatives: a structure-activity study

Pinusolide, a labdane-type diterpene lactone isolated from Biota orientalis, was found to be a potent platelet-activating factor (PAF) receptor binding antagonist. To investigate the structure-activity relationship and find derivatives with improved pharmacological profiles, 17 pinusolide derivatives were prepared and tested for their ability to inhibit the PAF receptor binding. The results demonstrated that the carboxymethyl ester group at C-19, the integrity of the alpha,beta-unsaturated butenolide ring, and the exocyclic olefinic function of pinusolide are all necessary for its maximum PAF receptor binding inhibitory activity. Among the derivatives, the 17-nor-8-oxo derivative 8 was found to be as potent as pinusolide. The results also suggested that several derivatives warrant further pharmaceutical and pharmacological studies due to their improved water solubility (8 and 11) and apparent lack of susceptibility to Michael-type nucleophilic addition (13 and 18).

Expression of phospholipase C-gamma 1 and its transcriptional regulators in breast cancer tissues

BACKGROUND

PLC-gamma 1 is activated through direct interaction with growth factor receptor tyrosine kinase but little is known about the mechanisms controlling PLC-gamma 1 expression and its biological significance.

MATERIALS AND METHODS

Using immunoblotting, we evaluated PLC-gamma 1 protein overexpression in twenty breast cancer tissues. The expression of binding protein to GES1, GES2 and GES3, located in transcriptional regulator (GPE1) was found by electrophoretic mobility shift assay (EMSA). We also determined whether there was any correlation between prognostic factors (numbers of metastatic axillary nodes, histologic grade, c-erbB2, p53, and E-cadherin) and the overexpression of PLC-gamma 1 protein.

RESULT

On immunoblotting, 17 of 20 breast cancer tissues showed overexpression of PLC-gamma 1, a result of which was corresponded to that of immunohistochemistry. The binding proteins to GES1, GES2 and GES3 were overexpressed only when PLC-gamma 1 protein overexpression was apparent. Positive expression of E-cadherin only was significantly associated with PLC-gamma 1 protein overexpression (x = 0.607, p = 0.045).

CONCLUSION

GPE1 binding proteins might be the transcriptional regulator in PLC-gamma 1 overexpression and the relationship between expression of PLC-gamma 1 and E-cadherin would require further elucidation.