Art therapy masks reflect emotional changes in military personnel with PTSS.

Among disabling post-traumatic stress symptoms (PTSS) are irritability, aggressive behavior, distressing memories and general impaired cognition and negative mood. Art therapy interventions, including mask-making, can potentially alleviate these symptoms. We tested the hypothesis that art conveys emotions and predicted that blinded viewers would be able to perceive changes in theoretically derived emotional profiles expressed in art made by military personnel with PTSS from the onset to the end of therapy. Five service members and veterans exhibiting PTSS were enrolled in an 8-session art therapy protocol, during which they artistically transformed papier-mâché masks at the beginning and end of the protocol. We found that blinded viewers without knowledge of the masks' creation stage (onset or end of therapy) read initial masks as conveying more negative emotions (e.g., angry, upset, and challenged) and later masks as conveying more positive emotions (calm and pleasure). Based on the assessments from the blinded evaluators, we infer the emotional transition experienced by the participants was expressed in the masks. In an exploratory arm of the study, we also found that viewers were better able to empathize with the negative emotions experienced by participants with PTSS when asked to explicitly take their perspective.

Effect of supplementation of phytogenic feed additives on intake, in vitro fermentation, growth performance and carcass traits in weaned Barbari kids reared under intensive feeding.

Twenty-four weaned male Barbari kids (age 144.67 days; weight 11.99 ± 0.49 kg) were divided equally into three groups (T1, T2, and T3) in order to investigate the effect of supplementation of phytogenic feed additives (herbal mixture) in the complete pelleted feed on growth performance, in vitro rumen fermentation and carcass quality in kids reared under stall-fed condition. Treatment groups were as follows: T1, concentrate mixture (40%) plus arhar (Cajanus cajan) straw (60%) in total mixed ration (TMR) form fed ad libitum; T2, T1 diet in complete feed pellets form fed ad libitum; and T3, T1 diet in complete feed pellets form supplemented with herbal mixture (Tulsi/Haldi/Amla/Arni; ratio 1:1:1:1 on DM basis) at 0.5% in complete feed fed ad libitum. The experimental kids in each group were allowed for feeding for 8 months by following the respective feeding schedule. Rumen fermentation pattern under in vitro system was also studied using the same three diets as substrates. After 240 days of feeding, all goats were slaughtered following standard protocol. Total body weight gain (kg) and average daily gain (ADG, g/day/kid) were 18.57, 22.26, and 23.06 kg, and 79.91, 101.49, and 100.18 g in T1, T2, and T3 treatments, respectively. Pelleting of TMR (T2) and supplementation of herbal mixture in pelleted feed (T3) increased (P < 0.001) average daily weight gain in Barbari kids compared to T1 (TMR). Average dry matter intake (DMI, g/day/kid) during growth trial was greater (P < 0.05) in T3 (1079.17) than T1 (849.76) and T2 (968.76). Feed conversion efficiency was 8.92, 9.48, and 8.68% in T1, T2, and T3, respectively. The difference was statistically non-significant among the treatments. Supplementation of herbal mixture in the complete pelleted substrate had adjunct effect on improvement of TCA-precipitable-N and total VFAs in the incubation medium under in vitro system. Carcass weight (kg) tended to increase in finisher kids under T2 (16.58) and T3 (16.70) than T1 (14.61), but the variation was non-significant. The dressing percentage was similar among three treatments. Similarly, the muscle protein, fat, and cholesterol contents remained unaffected by different dietary treatments. Therefore, it may be concluded that densification of feeds in the form of complete pelleted feed and further supplementation with potential phytogenic feed additives increased total DMI and ADG and tended to enhance meat production potential in finisher Barbari kids without changing the meat chemical composition.

Evaluation of two different transarterial chemoembolization protocols using Lipiodol and degradable starch microspheres in therapy of hepatocellular carcinoma: a prospective trial.

BACKGROUND: This prospective randomized trial is designed to compare the performance of conventional transarterial chemoembolization (cTACE) using Lipiodol-only with additional use of degradable starch microspheres (DSM) for hepatocellular carcinoma (HCC) in BCLC-stage-B based on metric tumor response. METHODS: Sixty-one patients (44 men; 17 women; range 44-85) with HCC were evaluated in this IRB-approved HIPPA compliant study. The treatment protocol included three TACE-sessions in 4-week intervals, in all cases with Mitomycin C as a chemotherapeutic agent. Multiparametric magnetic resonance imaging (MRI) was performed prior to the first and 4 weeks after the last TACE. Two treatment groups were determined using a randomization sheet: In 30 patients, TACE was performed using Lipiodol only (group 1). In 31 cases Lipiodol was combined with DSMs (group 2). Response according to tumor volume, diameter, mRECIST criteria, and the development of necrotic areas were analyzed and compared using the Mann-Whitney-U, Kruskal-Wallis-H-test, and Spearman-Rho. Survival data were analyzed using the Kaplan-Meier estimator. RESULTS: A mean overall tumor volume reduction of 21.45% (± 62.34%) was observed with an average tumor volume reduction of 19.95% in group 1 vs. 22.95% in group 2 (p = 0.653). Mean diameter reduction was measured with 6.26% (± 34.75%), for group 1 with 11.86% vs. 4.06% in group 2 (p = 0.678). Regarding mRECIST criteria, group 1 versus group 2 showed complete response in 0 versus 3 cases, partial response in 2 versus 7 cases, stable disease in 21 versus 17 cases, and progressive disease in 3 versus 1 cases (p = 0.010). Estimated overall survival was in mean 33.4 months (95% CI 25.5-41.4) for cTACE with Lipiosol plus DSM, and 32.5 months (95% CI 26.6-38.4), for cTACE with Lipiodol-only (p = 0.844), respectively. CONCLUSIONS: The additional application of DSM during cTACE showed a significant benefit in tumor response according to mRECIST compared to cTACE with Lipiodol-only. No benefit in survival time was observed.

Structural and electrical characterization of Bi2Se3 nanostructures grown by metal-organic chemical vapor deposition.

We characterize nanostructures of Bi(2)Se(3) that are grown via metal-organic chemical vapor deposition using the precursors diethyl selenium and trimethyl bismuth. By adjusting growth parameters, we obtain either single-crystalline ribbons up to 10 µm long or thin micrometer-sized platelets. Four-terminal resistance measurements yield a sample resistivity of 4 mΩ·cm. We observe weak antilocalization and extract a phase coherence length l(ϕ) = 178 nm and spin-orbit length l(so) = 93 nm at T = 0.29 K. Our results are consistent with previous measurements on exfoliated samples and samples grown via physical vapor deposition.

Studies on commuters' exposure to BTEX in passenger cars in Kolkata, India.

Commuters' exposure to volatile organic compounds (VOCs) especially BTEX travelling in passenger cars in Kolkata, India were quantified in Phase I (2001-2002) and Phase II (2003-2004). Monitoring was made inside and in the immediate outside of passenger cars fitted with and without catalytic converters using different types of fuels, along two congested urban routes. During Phase I of the study, the benzene content in gasoline was 5% and the mean concentration of in-vehicle benzene in cars without catalytic converter was found to be as high as 721.2 microg/m3. In Phase II when the benzene content was reduced to <3% and with modified engine type, the mean in-vehicle benzene concentration was reduced to 112.4 microg/m3. The in-vehicle concentration varied with engine type and age of the vehicle. Roadside ambient mean concentration of benzene was 214.8 microg/m3 and 30.8 microg/m3 in Phase I and Phase II respectively.

Safety assessment of a novel niacin-bound chromium-based energy formulation.

Over 35 million adults suffer from fatigue or lack of energy. In this study, we assessed the safety of a novel niacin-bound chromium-based Energy Formulation, which also contained caffeine, D-ribose, Withania somnifera extract, and selected amino acids. Niacin-bound chromium is a novel source of bioavailable chromium (III), and known to promote healthy lipid profile. Male and female Sprague-Dawley rats were fed 125 ppm Energy Formulation for 90 consecutive days. Body weight, feed, and water intake were monitored over the period of 90 days. No significant changes were observed between the control and treatment groups following subchronic supplementation with this Energy Formulation. Furthermore, no significant changes were observed in selected organ weights individually and as percentages of body and brain weights. The Energy Formulation supplementation did not cause changes in hepatic lipid peroxidation or DNA fragmentation after 30, 60, or 90 days of treatment. Hematology, clinical chemistry, and histopathological evaluations revealed no adverse effects in the treatment group. These findings demonstrate the safety of this Energy Formulation.

Safety and Toxicological Evaluation of a Novel, Standardized 3-O-Acetyl-11-keto-beta-Boswellic Acid (AKBA)-Enriched Boswellia serrata Extract (5-Loxin(R)).

The novel anti-inflammatory properties of the gum resin derived from Boswellia serrata, also known as Salai guggal in Ayurvedic medicine, are well recognized and highly recommended for human consumption. The active constituents of the gum resin are boswellic acids (BAs). Among the BAs, AKBA potently inhibits 5-lipoxygenase product formation with an IC(50) of 1.5 m muM. We developed a novel Boswellia serrata extract (5-Loxin(R)) enriched with 30% AKBA (US Patent 2004/0073060A1). The genetic basis of the anti-inflammatory effects of 5-Loxin(R) was explored in a system of TNFalpha-induced gene expression in human microvascular endothelial cells. 5-Loxin(R) significantly prevented the TNFalpha-induced expression of matrix metalloproteinases and adhesion molecules (ICAM-1 and VCAM-1), and inducible expression of the mediators of apoptosis. With such interesting findings, we planned to determine the broad-spectrum safety of 5-Loxin(R). Acute oral, acute dermal, primary skin and eye irritation, and dose-dependent 90-day subchronic toxicity studies were conducted. In safety studies, acute oral LD(50) of 5-Loxin(R) was found to be greater than 5,000 mg/kg in both male and female Sprague-Dawley rats. No changes in body weight or adverse effects were observed following necropsy. Acute dermal LD(50) of 5-Loxin(R) was found to be >2,000 mg/kg. Primary skin irritation test was conducted with 5-Loxin(R) on New Zealand Albino rabbits and 5-Loxin(R) was classified as nonirritating. Primary eye irritation test was conducted with 5-Loxin on rabbits and 5-Loxin(R) was classified as mildly irritating to the eye. A dose-dependent 90-day subchronic toxicity study demonstrated no significant changes in selected organ weights individually and as percentages of body and brain weights. 5-Loxin(R) supplementation did not cause changes in hepatic DNA fragmentation on 30, 60, or 90 days of treatment. Hematology, clinical chemistry, and histopathological evaluations did not show any adverse effects in all organs tested. Taken together, these results demonstrate the broad spectrum safety of 5-Loxin(R).

Genotoxic effect of raw betel-nut extract in relation to endogenous glutathione levels and its mechanism of action in mammalian cells.

The mutagenic and carcinogenic potency of betel-nut components is well established. This study was undertaken to determine the genotoxic potency of an aqueous extract of raw betel nut (AEBN) in relation to the endogenous glutathione (GSH) level in mouse bone marrow cells (BMC) and human peripheral blood lymphocytes (PBLs), and to find out whether arecoline (ARC), an alkaloid of betel nut, could generate reactive oxygen species (ROS) in these cells. It was observed that AEBN has genotoxic properties, which is further enhanced by depletion of endogenous GSH levels. However, the degree of enhancement varies with the type of parameter and cell system studied. The present data indicate that the generation of ROS by ARC could partially contribute to the induction of chromosomal aberrations (CAs), since the frequency of ARC-induced CAs was reduced either by post-treatment with superoxide dismutase (SOD) or in anoxic conditions. However, the induction of sister chromatid exchanges (SCEs) probably involves p53-dependent changes in cell proliferation and allowing some repair of DNA damage. The extent of damage for each parameter was higher when the mice were exposed to AEBN for 30 days than 5 days. Longer exposure showed higher level of p53 expression in mouse BMC, which could block the damaged cells from proliferation and allow the cells to repair the DNA damage.

Differential responses of certain brain phosphoesterases to aluminium in dietary protein adequacy and inadequacy.

The aluminium-induced neurotoxic consequences include, among other factors, dephosphorylation, phosphorylation as well as hyperphosphorylation of specific macromolecules. Accordingly, activities of phosphoesterases were measured in different regions of rat brain, maintained with either adequate or inadequate protein diet, following aluminium exposure. Male Wistar rats weighing 80-100 g were treated with aluminium chloride at a dose of 15% of the LD50 for 4 weeks. In different regions of the brain of aluminium-exposed rats, significant variation in both phosphomonoesterase and phosphodiesterase activities have been recorded. These alterations were found to be varied when the rats were subjected to dietary protein insufficiency. These findings demonstrate the specificity of aluminium on different phosphoesterases. These regional variations may be attributed to the accumulated level of aluminium or may be due to cellular localization of these enzymes and linked to whether the enzymes are compartmentalized with different aluminium hydration species.

Structure and stereochemistry of nardostachysin, a new terpenoid ester constituent of the rhizomes of Nardostachys jatamansi.

The structure and stereochemistry of a new terpenoid ester, nardostachysin (1), isolated from the rhizomes of Nardostachys jatamansi, were established as the 7',8'-dihydroxy-4'-methylene hexahydrocyclopenta[c]pyran-1'-one-8'-methyl ester of 7, 9-guaiadien-14-oic acid, by spectral and chemical studies.

Evaluation of oral hypo-osmolar glucose-based and rice-based oral rehydration solutions in the treatment of cholera in children.

UNLABELLED: In a randomized controlled clinical trial, the efficacy of a low-sodium low-glucose oral rehydration solution (ORS) and a low-sodium rice-based ORS was compared with standard WHO glucose ORS in the treatment of severe cholera in children aged 2-10y. In total, 120 children were evaluated for the study, of whom 58 patients were positive for Vibrio cholerae and were included in the study. Of these 58 cases, 19 received rice-based hypo-osmolar ORS, 20 received WHO-ORS and 19 received glucose-based hypo-osmolar ORS. The clinical characteristics (age, preadmission duration of diarrhoea, frequency of stool before admission, incidence of vomiting, body weight and volume of initial fluid requirement) were comparable in the three treatment groups. All patients received tetracycline in a dose of 50 mg/kg/d of body weight in 4 divided doses for 3 d. CONCLUSIONS: Patients who received rice-based hypo-osmolar ORS had subsequently reduced (p < 0.05) stool output, ORS consumption and diarrhoea duration than the patients who received either WHO-ORS or glucose-based hypo-osmolar ORS.

The reversible antifertility effect of Piper betle Linn. on Swiss albino male mice.

To study the antifertility effect of an extract (alcoholic) of the leaf-stalk of Piper betle Linn., one set of experiments with two different doses in Swiss male albino mice were evaluated. Initially, 500 mg of the leaf-stalk extractive for 30 days and then 1000 mg for next 30 days/animal/day/kg body weight were administered orally. The extract reduced fertility to 0% within 60 days. Suppression of cauda epididymal sperm count and motility (p <0.05) was observed. Biochemical parameters did not show any marked alterations in testosterone content in serum nor 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity in testes although fructose content in seminal vesicles was reduced as are the weights of reproductive organs. The cholesterol content in testes increased, although not appreciably. After cessation of drug (plant extract) treatment, the altered parameters recovered. Results suggest that the contraceptive effect of the extract of leaf-stalk of Piper betle Linn. is mainly on the maturation process of spermatozoa in epididymides without influencing hystemic hormonal profiles. Withdrawal of the extract restored all altered parameters including organ weights and fertility after 60 days.

Pre-clinical toxicity evaluation of leaf-stalk extractive of Piper betle Linn. in rodents.

Studies on pre-clinical toxicity were undertaken to determine the haematological and biochemical changes after administration of alcoholic extract of leaf-stalk of P. betle in rats and mice. Acute and chronic toxicity experiments were performed on mice and rats according to WHO protocol. Different doses of plant extractive were administered for toxicity studies on short and long term basis. Haematological, biochemical profiles and enzymatic studies (transaminases and phosphatases) indicated that the drug (plant extractive) was devoid of toxicity.

Cleogynol, a novel dammarane triterpenoid from Cleome gynandra.

Chemical examination of Cleome gynandra (whole plant excluding seeds) led to the isolation and identification of a novel (20S, 24S)-epoxy-19,25-dihydroxydammarane-3-one hemiketal (1). The structure of the new compound, designated cleogynol, was determined using spectral and chemical methods.

Randomized placebo-controlled trial of 2,3-dimercaptosuccinic acid in therapy of chronic arsenicosis due to drinking arsenic-contaminated subsoil water.

INTRODUCTION: Chronic arsenic toxicity producing various clinical manifestations is currently epidemic in West Bengal, India, Bangladesh, and other regions of the world. Animal studies have indicated that 2,3-dimercaptosuccinic acid can be used as an oral chelating agent. A prospective, double-blind, randomized controlled trial was carried out to evaluate the efficacy and safety of 2,3-dimercaptosuccinic acid for chronic arsenicosis due to drinking arsenic-contaminated (> or = 50 micrograms/L) subsoil water in West Bengal. METHOD: Twenty-one consecutive patients with chronic arsenicosis were individually randomized (random number; assignment made by individual not evaluating patients) into 2 groups: 11 patients (10 male, age 25.5 +/- 8 years) received 2,3-dimercaptosuccinic acid 1400 mg/d (1000 mg/m2) in the first week and 1050 mg/d (750 mg/m2) during the next 2 weeks with a repeat course 3 weeks later. The other 10 patients (all male, age 32.2 +/- 9.7 years) were given placebo capsules for the same schedule. The clinical features were evaluated by an objective scoring system before and after treatment. Routine investigations including liver function tests, arsenic concentrations in urine, hair, and nails, and skin biopsy evaluations were also completed. RESULTS: Though there was improvement in the clinical score of 2,3-dimercaptosuccinic acid-treated patients, similar improvement was observed in the placebo-treated group. There were no statistical differences in the clinical scores between the 2 groups at the beginning and at the end of treatment. Similarly, no differences were found for the other investigated parameters. CONCLUSION: Under the conditions of this study, 2,3-dimercaptosuccinic acid was not effective in producing any clinical or biochemical benefit or any histopathological improvement of skin lesions in patients with chronic arsenicosis.

Impact of protein malnutrition on subcellular nucleic acid and protein status of brain of aluminum-exposed rats.

Nucleic acid and protein content in various cellular fractions of different regions of the brain were investigated in male albino rats following aluminum (Al) exposure (at the dose of 15% of LD50 i.p. for 28 days) on either an adequate or inadequate protein diet. It was observed that there was a decrease in homogenate DNA content in the thalamic area (Th), midbrain-hippocampal region (MH) and cerebellum (CL), but not in the cerebrum (CC) of the protein-restricted group of animals. Increased RNA content was recorded in the ribosomal and soluble fractions of CL of the adequately protein-fed animals compared to pair-fed controls. In the low-protein-fed animals, on the other hand, a decrease in RNA content was observed in the whole homogenate and nuclear fractions of CC, MH and CL, the ribosomal and soluble fractions of MH and CL, and in the mitochondrial fraction of TH. Ribonucleolytic activity was found to be increased only in the Th and CL of the adequately protein-fed group. Protein contents in the subcellular fractions of these four regions remain almost unaltered with the present dose and duration of Al-exposure; only the soluble fraction of CC and microsomal fraction of Th of the low-protein-fed group showed a significant decrease. The results of the present investigation confirm that Al has generally depressive effects on the nucleic acid metabolism of the brain and suggest that these effects are region-specific as well as dependent on dietary protein level. It is further suggested that alterations in the cellular microenvironment, caused by protein malnutrition, may play a significant role in the modification of the effects of Al in the brain.

Conformational changes in plant Ins(1,4,5)P3 receptor on interaction with different myo-inositol trisphosphates and its effect on Ca2+ release from microsomal fraction and liposomes.

The interaction of the only reported plant inositol trisphosphate receptor with different myo-inositol trisphosphates (InsP3 species), namely Ins(1,4,5)P3, Ins(1,3,4)P3, Ins(1,5,6)P3, and Ins(2,4,5)P3, were studied to assess the extent of Ca2+ mobilization from microsomes/vacuoles as well as liposomes in vitro. Ins(1,4,5)P3 and Ins(2,4,5)P3 bind with the receptor with comparable affinities, as evidenced from their dissociation constants (Kd approx. 100 nM at 5 degrees C), whereas the interaction between Ins(1,3,4)P3/Ins(1,5,6)P3 and the receptor was not detected even with these ligands at 5 microM. Ins(1,3,4)P3/Ins(1,5,6)P3 isomers also do not elicit Ca2+ release from liposomes or microsomes/ vacuoles. The ability of any InsP3 to bind the receptor for Ins(1,4,5)P3 is a prime requirement for Ca2+ release. However, the comparison of binding affinities at a single temperature does not help to correlate it directly with the extent of Ca2+ release from the intracellular stores because the concentration of Ca2+ released by Ins(1,4,5)P3 as estimated over a period of 20 s is 3500 +/- 200 nM/mg of protein and is about 4-fold higher than that by Ins(2,4,5)P3 under identical conditions. To understand the role of the receptor conformation in Ca2+ release by different isomers, we have probed the conformational change of the receptor when the different isomers bind to it. Accessibility of the tryptophan residues in the free and Ins(1,4,5)P3/Ins(2,4,5)P3-bound receptor was monitored by a neutral fluorescence quencher, acrylamide. The resulting Stern-Volmer-type quenching plots of the internal fluorescence indicate a change in the conformation of the receptor on binding to Ins(1,4,5)P3 and Ins(2,4,5)P3. It is also detected when far-UV CD spectra (205-250 nm) of the free and ligand [Ins(1,4,5)P3/Ins(2,4,5)P3]-bound receptor are compared. The results from CD spectroscopic studies further indicate that the conformational changes induced by the two isomers are different in nature. When thermodynamic parameters, such as enthalpy (delta H), entropy (delta S) and free energy (delta G), for the formation of the two InsP3-receptor complexes are compared, a major difference in the extent of changes in enthalpy and entropy is noted. All these findings taken together support the proposition that it is the overall interaction leading to the requisite conformational change in the receptor that determines the potency of the InsP3 isomers in their abilities of Ca2+ mobilization from the intracellular stores or reconstituted liposomes.

A comparative transcription map of the murine bare patches (Bpa) and striated (Str) critical regions and human Xq28.

The X-linked developmental mouse mutations bare patches (Bpa) and striated (Str) may be homologous to human X-linked dominant chondrodysplasia punctata (CDPX2) and incontinentia pigmenti (IP2), respectively, based on their genetic mapping and clinical phenotypes. Bpa and Str have been localized to an overlapping critical region of 600 kb that demonstrates conserved gene order with loci in human Xq28 between DXS1104 and DXS52. As part of efforts to isolate the genes involved in these disorders, we have begun to develop a comparative transcription map spanning this region in both species. Using techniques of cross-species conservation and hybridization, exon trapping, and cDNA selection we have identified four known genes or members of gene families--caltractin, a member of the gamma-aminobutyric acid (GABAA) receptor gene family, a member of the melanoma antigen gene (MAGE) family, and several members of the murine-specific, X-linked lymphocyte regulated gene (Xlr3) family. Trapped exons and, in some cases, longer cDNAs have been isolated for potentially 7-9 additional genes. One cDNA demonstrates highly significant homology with members of the Krüppel family of zinc finger transcription factors. A second novel cDNA demonstrates homology at the 3' end of the predicted amino acid sequence to a LIM domain consensus. Gene order appears conserved among those cDNAs determined to be present in both human and mouse. Three of the murine transcripts appear to be present in multiple copies within the Bpa/Str critical region and could be associated with a predisposition to genomic rearrangements. Reverse transcriptase PCR (RT-PCR) and Northern analysis demonstrate that several of the transcripts are expressed in mid-gestation murine embryos and neonatal skin, making them candidates for the Bpa and Str mutations and their respective homologous human disorders.

Cortical blindness and visual imagery.

Controversy exists concerning the neural basis underlying visual imagery. Some propose that visual images evoked from memory are mediated by primary visual cortices. Others argue that these primary visual areas perform computations on elementary visual features when constructing visual representations from retinal input but that they are not activated during recall of these representations. The visual imagery abilities of patients with cortical blindness may resolve this controversy. The proposition that primary visual cortex is necessary for visual imagery predicts a cortically blind subject's inability to perceive visual stimuli would be accompanied by an inability to image visually. Our investigations of three patients with cortical blindness provide strong evidence that primary visual cortices are not essential for the mediation of visual images recalled from memory.

Inactivation of rsmA leads to overproduction of extracellular pectinases, cellulases, and proteases in Erwinia carotovora subsp. carotovora in the absence of the starvation/cell density-sensing signal, N-(3-oxohexanoyl)-L-homoserine lactone.

The soft-rotting bacterium, Erwinia carotovora subsp. carotovora 71, produces extracellular enzymes such as pectate lyase isozymes (Pels), cellulase (Cel), polygalacturonase (Peh), and protease (Prt). While the extracellular levels of these enzymes are extremely low when the bacterium is grown in salts-yeast extract-glycerol (SYG) medium, the enzymatic activities are highly induced in SYG medium supplemented with celery extract. By transposon (mini-Tn5) mutagenesis, we isolated a RsmA- mutant, AC5070, which overproduces extracellular enzymes; the basal levels of Pel, Peh, and Cel in AC5070 are higher than the induced levels in the RsmA+ parent, AC5047. While Peh production is mostly constitutive in AC5070, Pel, Cel, and Prt production is still inducible with celery extract. The high basal levels of pel-1, pel-3, and peh-1 mRNAs in AC5070 demonstrate that overproduction of the pectolytic enzymes is due to the stimulation of transcription. Using chromosomal DNA flanking mini-Tn5 as a probe, we cloned the wild-type rsmA+ allele, which suppresses Pel, Peh, Cel, and Prt production in both RsmA+ and RsmA- strains. The RsmA- mutant, like its parent, produces N-(3-oxohexanoyl)-L-homoserine lactone (HSL), a starvation/cell density-sensing signal required for extracellular enzyme production. To examine the role of HSL, we constructed HSL-deficient strains by replacing hslI, a locus required for HSL production, with hslI::Tn3HoHo1-Spc. While the basal levels of Pel, Peh, Cel, and Prt are comparable in the RsmA- mutant and its HSL- derivative, these enzymes are barely detectable in the Hsl- derivative of the RsmA+ parent strain.(ABSTRACT TRUNCATED AT 250 WORDS)