Induction of gene expression in sheepshead minnows (Cyprinodon variegatus) treated with 17beta-estradiol, diethylstilbestrol, or ethinylestradiol: the use of mRNA fingerprints as an indicator of gene regulation

The recent interest in hormonally active environmental contaminants has sparked a drive to find sensitive methods to measure their effects on wildlife. A molecular-based assay has been developed to measure the induction of gene expression in sheepshead minnows (Cyprinodon variegatus) exposed in vivo to the natural and pharmaceutical estrogens 17beta-estradiol, ethinylestradiol, and diethylstilbestrol. This method used differential display reverse transcriptase polymerase chain reaction assays to compare the expression of individual mRNAs from control and estrogen-exposed fish. Forty-eight differentially expressed cDNAs were isolated by this method, including cDNAs for vitelline envelope proteins and vitellogenin. The mRNA expression patterns for fish injected with a pharmacological dose of estradiol (5 mg/kg) were identical to those obtained in fish receiving constant aqueous exposure to 212 ng estradiol/liter. Further, the cDNA "fingerprint" pattern observed in the estradiol-treated fish also matched that obtained in fish receiving continuous-flow aqueous exposures to 192 ng ethinyl estradiol/liter and a nominal concentration of 200 ng diethylstilbestrol/liter. The results demonstrate a characteristic expression pattern for genes upregulated by exposure to a variety of natural and anthropogenic estrogens and suggest this approach may be valuable to examine the potential effects of environmental contaminants on other endocrine-mediated pathways of reproduction, growth, and development.

Hahella chejuensis gen. nov., sp. nov., an extracellular-polysaccharide-producing marine bacterium

A bacterial strain, designated 96CJ10356T, which produced abundant extracellular polysaccharides and red pigment was isolated from marine sediment collected from Marado, Cheju Island, Republic of Korea. The organism is Gram-negative, aerobic, rod-shaped and motile. Growth was not observed in the absence of NaCl, and was optimal at an NaCl concentration of 2%. The strain contained oxidase and catalase, and was able to hydrolyse aesculin and gelatin. The major cellular fatty acids were saturated or monounsaturated straight-chain fatty acids. An almost complete 16S rDNA sequence of the test strain was determined. Phylogenetic analysis based on the neighbour-joining and Fitch-Margoliash methods indicated that the organism formed a distinct phyletic line within the gamma Proteobacteria. This relationship was also supported by sequence comparison, as no valid bacterial species showed more than 90% sequence homology with the isolate. It is clear from polyphasic evidence that the isolate merits the status of genus in the gamma subclass of the Proteobacteria, and the name Hahella chejuensis gen. nov., sp. nov. is proposed for the marine isolate 96CJ10356T (= KCTC 2396T = IMSNU 11157T).

Expression of Fas and Fas-related molecules in human hepatocellular carcinoma

Many tumor cells, including hepatocellular carcinoma (HCC), express both Fas and its ligand on their surfaces, and it has remained a mystery why such cells do not spontaneously become apoptotic. In the current study, we analyzed the alterations of Fas structure and the expression of Fas and Fas ligand (FasL) and of Fas pathway inhibitors, including soluble Fas (sFas), Fas-associated phosphatase-1 (FAP-1), and bcl-2, in 50 cases of human HCC. Monoallelic loss of the Fas gene, as determined by loss of heterozygosity with intragenic polymorphisms, was observed in 5 of the 34 informative cases (15%), but none of the 50 cases showed Fas gene mutation. Expression of Fas and FasL was detected in 44 (88%) and 50 (100%) cases, respectively. sFas messenger RNA, as analyzed by in situ reverse-transcription polymerase chain reaction was expressed in 42 of the 50 cases (84%), and FAP-1 expression was observed in 40 of the 50 cases (80%). In contrast, none of the 50 cases showed bcl-2 expression. Our results showed that the majority of the HCCs (88%) coexpressed a death receptor, Fas and its cognate ligand, FasL, but all HCCs showed one or more alterations of the Fas pathway molecules known to inhibit Fas-mediated apoptosis. These findings suggest that the expression of sFas and FAP-1 and, in part, loss of Fas expression, rather than Fas gene alteration or bcl-2 expression, may be involved in the Fas resistance of HCC in vivo and that these mechanisms may play important roles in the pathogenesis of human HCC. HUM PATHOL 32:250-256.

Intestinal histopathology and in situ postures of Gymnophalloides seoi in experimentally infected mice

The intestinal histopathology and in situ postures of Gymnophalloides seoi (Digenea: Gymnophallidae) were studied using C3H/HeN and C57BL/6 mice as experimental hosts; the effects of immunosuppression were also observed. The metacercariae isolated from naturally infected oysters, 300 or 1,000 in number, were infected orally to each mouse, and the mice were killed at days 3-21 post-infection (PI). In immunocompetent (IC) mice, only a small number of flukes were found in the mucosa of the duodenum and jejunum during days 3-7 PI, with their large oral suckers pinching and sucking the root of villi. The intestinal mucosa showed mild villous atrophy, crypt hyperplasia, and inflammations in the villous stroma and crypt, with remarkable goblet cell hyperplasia. These mucosal changes were almost restored after days 14-21 PI. In immunosuppressed (IS) mice, displacement as well as complete loss of villi adjacent to the flukes was frequently encountered, otherwise the histopathology was generally mild, with minimal goblet cell hyperplasia. In these mice, numerous flukes were found, and it seemed that they were actively moving and rotating in situ. Several flukes were found to have invaded into the submucosa, almost facing the serosa. These results indicate that in IC mice the intestinal histopathology caused by G. seoi is generally mild, and the flukes do not penetrate beyond the mucosa, however, in IS mice, the flukes can cause severe destruction of neighboring villi, and some of them invade into the submucosa.

Suppression of collagen-induced arthritis with histone H1

Besides roles in nucleus mediating the condensation of DNA into chromatin, the involvement of histones in autoimmune diseases, hormone regulation, and killing leukemia cells has been reported. In order to investigate the functions of histones on an autoimmune disease, histone H1 was injected into collagen-induced arthritis (CIA) mice. A dramatic suppression of CIA by histone H1 was observed at a dose of 1 mg/kg bodyweight of mouse. In addition, the increased level of anti-inflammatory cytokine IL-10 was detected in cultured splenocytes from the mouse treated with histone H1. These findings suggest that histone H1 suppresses the collagen-induced arthritis, possibly by increasing the level of IL-10 production.

Recurrent hepatocellular carcinoma after spontaneous regression

The prognosis of untreated hepatocellular carcinoma (HCC) is usually grave, although there have been a few case reports of spontaneous regression. Tumor recurrence after spontaneous regression has been rarely reported, and there have been no previous reports of recurrent hepatocellular carcinoma after spontaneous regression. Two cases of hepatocellular carcinoma that spontaneously regressed and subsequently recurred are presented. The patients' tumors spontaneously regressed, as reflected by the radiologically evidenced reduction in tumor size and markedly decreased alpha-fetoprotein levels. Subsequent tumor recurrences after regression were evidenced by radiologic findings of newly growing nodules and appreciably increased alpha-fetoprotein levels. To the authors' knowledge, these two patients represent the first reported cases of hepatocellular carcinoma recurrence after spontaneous regression. In both of these patients, new hepatocellular carcinomas recurred at different sites before the spontaneous regression of the original HCCs was complete. Although the precise causes of the regression and the subsequent recurrence remain to be further investigated, this phenomenon suggests that multicentric hepatocarcinogenicity and intratumoral events in each hepatocellular carcinoma nodule may be involved.

Evaluation of DNA match probability in criminal case

The new emphasis on quantification of evidence has led to perplexing courtroom decisions and it has been difficult for forensic scientists to pursue logical arguments. Especially, for evaluating DNA evidence, though both the genetic relationship for two compared persons and the examined locus system should be considered, the understanding for this has not yet drawn much attention. In this paper, we suggest to calculate the match probability by using coancestry coefficient when the family relationship is considered, and thus the performances of the identification values depending on the calculation of match probability are compared under various situations.

An immunohistochemical study on the endocrine cells in the alimentary tract of the red-eared slider (Trachemys scripta elegans)

The regional distribution and relative frequency of endocrine cells in the alimentary tract of the red-eared slider, Trachemys scripta elegans, were investigated by immunohistochemical methods using 10 antisera. Most of the immunoreactive cells in the intestine were spherical or spindle-like in shape (open-type cells), while round cells (closed-type cells) were occasionally found in the stomach. These immunoreactive cells were located in the basal portion of the intestine, including the oesophagus, and in the gastric glands of the stomach. Cg A-immunoreactive cells were restricted to the pylorus and duodenum and were few in number. Serotonin-immunoreactive cells, which were most commonly found in the pylorus, were found in the epithelia throughout the alimentary tract at various frequencies. Gastrin-immunoreactive cells were found in the pylorus, duodenum and jejunum at moderate, low and very low frequencies, respectively. Somatostatin-immunoreactive cells were found throughout the alimentary tract except for the rectum, at various frequencies. Glucagon-immunoreactive cells were detected in the fundus, pylorus, jejunum and ileum at low or very low frequencies. CCK-8-immunoreactive cells were found in the pylorus, fundus and duodenum at very low, low and moderate frequencies, respectively. Bombesin-immunoreactive cells were restricted to the fundus and pylorus at low frequencies. No secretin-, BPP- or VIP-immunoreactive cells were found in this study.

Purification and characterization of antithrombotics from Syzygium aromaticum (L.) MErr. & PERRY

Two antithrombotic polysaccharides with relatively high molecular weight (HMW) and low molecular weight (LMW) were isolated from the flower buds of Syzygium aromaticum (L.) MERR. & PERRY (clove) by anion-exchange chromatography, hydrophobic interaction column chromatography and size exclusion chromatography (LMW: EC-2B-IIIa-2, M.W. ca. 34000; HMW: EC-2C-Ia-2, M.W. ca. 103000). The LMW polysaccharide was mainly composed of Rha, Gal, GalA and Ara (molar %: 24.1, 18.9, 18.0 and 17.9, respectively) with 10.8% of sulfate and 18.2% of protein. The HMW fraction consisted of Ara, Gal, Glc and Rha (molar %: 26.0, 23.7, 17.5 and 12.4, respectively) with 15.4% of sulfate and 8.0% of protein. Both polysaccharides had the backbone of type I rhamnogalacturonan and the side chain of arabinan. Also, most of the sulfates were attached at the position 6 of 3-linked galactosyl residues. Compared to the antithrombotic activity of the HMW fraction (plasma clotting time of 145 s in APTT assay), the LMW fraction displayed a slightly low activity (90 s). However, animal studies indicated that crude LMW polysaccharide did not show acute toxicity, while the acute LD50 of the HMW fraction was approximately 2-fold lower than that of heparin.

Prevalence of Gs alpha mutations in Korean patients with pituitary adenomas

The reported frequencies of Gs alpha mutations (gsp mutations) in growth hormone (GH)-secreting pituitary adenomas are variable (ranging from 4.4 to 43%), and the presence of these mutations in the other pituitary adenomas is still a matter of controversy. Previous clinical and biochemical analyses of patients with GH-secreting pituitary adenomas and gsp mutations produced conflicting results and did not demonstrate obvious characteristics. Therefore, we investigated the prevalence of gsp mutations in Korean patients with pituitary adenomas and elucidated the characteristics of these patients. Forty-four GH-secreting adenomas, 7 prolactin (PRL)-secreting adenomas and 32 clinically non-functioning adenomas were examined for the presence of point mutations in codon 201 and 227 of the Gs alpha gene using a nested PCR and direct sequencing of DNA extracted from fresh tissue or paraffin-embedded pituitary adenoma samples. Seven of the 44 GH-secreting pituitary adenomas had point mutations at codon 201 or 227; of these, five mutations were in codon 201 and two were in codon 227. In patients with gsp mutations, mean tumor size was significantly smaller than in patients without gsp mutations (15.9+/-8.7 mm vs. 24.9+/-14.9 mm, P<0.05). Age, sex, basal GH levels, GH response to oral glucose loading, GH response to octreotide and surgical outcome were not different in the two groups. One of the 32 clinically non-functioning pituitary adenomas had a point mutation at codon 201; none of the seven prolactinomas had these mutations. These results show that gsp mutations are not rare in Korean acromegalic patients and mean tumor size is significantly smaller in acromegalic patients with gsp mutations. Our results also confirm the low frequency of gsp mutations in clinically non-functioning pituitary adenomas and the absence of gsp mutations in prolactinoma.

Relationship of empathy to appraisal, depression, life satisfaction, and physical health in informal caregivers of older adults

The relationship between empathy and caregiving appraisal and outcomes was examined among 140 informal caregivers of older adults. Caregivers with high cognitive empathy appraised the caregiving situation as less stressful and less threatening, were less depressed, and reported higher life satisfaction than did caregivers with low cognitive empathy. The caregivers' appraisal, along with educational levels and total household income, significantly predicted individual differences in caregiver depression, life satisfaction, and perceived physical health. Emotional empathy was negatively related to life satisfaction. There appeared to be distinct roles for emotional and cognitive empathy in informal caregiving outcomes. The study supported the important role of caregiving appraisal and resources in caregiving outcomes.

Seasonal changes of carotenoid pigments and color in Hamlin, Earlygold, and budd blood orange juices

The developmental patterns of carotenoids in Hamlin, Earlygold (an early-maturing selection), and Budd Blood sweet orange juices were studied during the September to mid-January period of the 1996-97 and 1997-98 seasons. The carotenoid concentration of Earlygold increased by as much as 4.9 times during the color development compared to 3.9 times in Hamlin and 4.5 times in Budd Blood juice in the same period. For the profiles of carotenoid pigment, dramatic changes occurred among the pigments that were present in high concentrations at the beginning of the season, with lutein and violaxanthin noted as the predominant pigments in Hamlin fruit. A marked increase in the percentage of beta-cryptoxanthin allowed it to become a major pigment in the late stage of maturation. The color development in the new cultivar Earlygold was especially notable, reaching the 36 color number, which is grade A, by late October to mid-November whereas Hamlin juice did not reach this grade A color number until January. Budd Blood juice was similar in carotenoid pigment content and seasonal changes to Hamlin juice, but also, the development of red anthocyanin pigment in January significantly increased juice color.

External compression of bronchus by aneurysm from divided major aortopulmonary collateral artery after unifocalization

The right ventricle to pulmonary artery connection with an extracardiac conduit, left pulmonary artery reconstruction, ligation of patent ductus arteriosus, and take-down of right Blalock--Taussig shunt were performed on a 1-year-8-month-old boy who had pulmonary atresia, ventricular septal defect, patent ductus arteriosus, and major aortopulmonary collateral arteries. He previously underwent the unifocalization and right modified Blalock--Taussig shunt at 9 months of age. He repeatedly had a difficulty in weaning from the mechanical ventilator. After removing the aneurysm from the divided major aortopulmonary collateral artery that compressed the left main bronchus externally, it was possible to wean him from the mechanical ventilator.

Differentiation between reinfection and recrudescence of helicobacter pylori strains using PCR-based restriction fragment length polymorphism analysis

The aim of this study was to evaluate whether PCR-based restriction fragment length polymorphism (RFLP) analysis was effective in differentiating between reinfection and recrudescence of H. pylori strains. Following a 1-2 week regimen of omeprazole 20 mg, amoxicillin 1.0 g, and clarithromycin 500 mg twice daily, twenty patients with duodenal ulcer were enrolled in the study. Ten patients (group 1, control) were not successfully treated, and another 10 patients (group 2) exhibited recurrence of infection 6-24 months following the therapy. Follow-up diagnosis was performed by Giemsa stain and CLO test. RFLP profiles of antral and midbody biopsy specimens were compared before and after therapy. PCR products using the ureC gene were digested with restriction enzymes Hha I, Mbo I, and Hind III, and the fragments generated were analyzed by agarose gel electrophoresis. Hha I, Mbo I, and Hind III digestion produced 13, 7, and 2 distinguishable digestion patterns, respectively. There was no difference in RFLP profiles seen before and after the therapy in 17 duodenal ulcer patients, while different RFLP profiles were discovered in 3 patients. Following treatment, one (group 2) patient differed in Mbo I, and two (one each from both groups) patients differed in Hha I and Mbo I RFLP patterns. Eight of group 2 patients showed recrudescence of previous infection and two patients had reinfection by another strain. This study supports the hypothesis that PCR-based RFLP analysis can be effective for differentiating reinfection and recrudescence of H. pylori strains following triple therapy.

Increased susceptibility to Kuru of carriers of the PRNP 129 methionine/methionine genotype

Kuru reached epidemic proportions by the mid-twentieth century among the Fore people of New Guinea and disappeared after the abolition of cannibalistic rituals. To determine susceptibility to kuru and its role in the spread and elimination of the epidemic, we analyzed the PRNP gene coding sequences in 5 kuru patients; no germline mutations were found. Analysis of the PRNP 129 methionine (M)/valine (V) polymorphism in 80 patients and 95 unaffected controls demonstrated that the kuru epidemic preferentially affected individuals with the M/M genotype. A higher representation of M/M carriers was observed among the affected young Fore males entering the age of risk, whereas a lower frequency of M/M homozygotes was found among the survivors. M/V and V/V genotypes predisposed to a lower risk of disease development and longer incubation times. These findings are relevant to the current outbreak of variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom, because all vCJD patients tested thus far have been M/M carriers.

Determination of human angiotensin converting enzyme (ACE) gene polymorphisms in erectile dysfunction: frequency differences of ACE gene polymorphisms according to the method of analysis

The D polymorphism of angiotensin converting enzyme (ACE) gene has been found to be associated with various diseases, and ACE may also be involved in the pathogenesis of erectile dysfunction. On the other hand, interpretation of the data on the association of DD genotype with various diseases is controversial, due to methodological and technical variations in detection of the polymorphisms. We investigated a possible association between the DD genotype and erectile dysfunction in a Korean population, and compared the frequency of ACEgenotypes using our multiplexed PCR method with those based on the conventional PCR method in a sample of erectile dysfunctional and control subjects. There was significant difference in the distribution of ACE genotypes between the erectile dysfunctional (conventional PCR) and the control subjects (multiplexed PCR) (chi2=7.395, p<0.05), but there was no significant difference in the distribution of the genotypes between both groups (chi2=0.815, p>0.05) when our multiplexed PCR method was used. Therefore our results suggest that especially the conventional PCR method for ACE gene polymorphism may require careful control and may need repeated testing to verify the insertion deletion (ID) heterozygotes, and that a multiplexed PCR method can markedly increase the detection rate of the I allele in ID heterozygotes. No association was found between I/D polymorphism and erectile dysfunctional subjects in the Korean population studied.

A sigmaB-like factor responsible for carotenoid biosynthesis in Streptomyces griseus

Self-cloning experiments with a high-copy-number plasmid and Streptomyces griseus IFO13350 led to the cloning of a 11-kb DNA fragment that conferred yellow pigment production on the host. The cloned fragment contained a gene cluster for carotenoid biosynthesis, in which two polycistrons, crtE (encoding geranylgeranyl pyrophosphate synthase)-crtI (phytoene dehydrogenase)-crtB (phytoene synthase)-crtV (functionally unknown methyltransferase-like protein) and crtY (lycopene cyclase)-crtT (functionally unknown methyltransferase-like protein)-crtU (beta-carotene dehydrogenase), were present in a convergent way. Since strain IFO13350 produced no detectable amount of carotenoids, an increase in the copy number of the crt gene cluster led to production of carotenoids at a detectable level. Overexpression of the stress-responsive sigmaB-like protein CrtS from Streptomyces setonii also activated the cryptic crt genes in S. griseus and conferred pigmentation. A CrtS homologue (sigmaCrtS) in S. griseus, which was predicted by a computer-aided homology search, caused carotenogenesis to the same extent as CrtS of S. setonii, indicating that the two sigmaB-like proteins were functionally the same. Yellow pigment production by S. griseus containing crtS under the control of a strong promoter on a high-copy-number plasmid resulted from activation of transcription of the crt genes, because overexpression of sigmaCrtS in S. griseus led to transcriptional activation of the promoters in front of crtE and crtY. S1 nuclease mapping showed that crtS itself was transcribed at a low level under the laboratory conditions, which may account for undetectable production of carotenoids. The crt genes were suggested to locate very near one end of the linear chromosome, since they were completely deleted in mutant HH1 having large deletions at both ends. The gene organization of crt in S. griseus is similar to that in S. coelicolor A3(2) where the whole crt gene set is near one end of the chromosome.

Toxicity and biodegradation of products from polyester hydrolysis

Toxicity of products from polyester hydrolysis such as succinic acid (SA), adipic acid (AA), mandelic acid (MA), terephthalic acid (TA), 1,4-butanediol (1,4-B), ethylene glycol (EG), styrene glycol (SG) and 1,4-cyclohexane dimethanol (1,4-C) was evaluated by phytotoxicity test on germination of young radish seeds and by cytotoxicity test on HeLa cells. The phytotoxicity test revealed SG > MA > 1,4-C > AA approximately SA > TA approximately EG > 1,4-B in order of decreasing toxicity taking into consideration the growth behavior after germination as well as the percentage of germination. Toxicity on HeLa cells decreased in slightly different order compared to that on young radish seeds, i.e. SG > 1,4-C > MA > TA > SA > AA > EG > 1,4-B. Tests for the phytotoxicity and for cytotoxicity indicated that the aromatic compounds were more harmful than the aliphatic ones. Each group of 4 strains which grew most rapidly on each agar plate containing SA, AA, MA, TA, 1,4-B, EG, SG and 1,4-C respectively as a sole carbon source was identified by the fatty acid methyl esters analysis. The modified Sturm test was carried out using the single isolated strain, an activated sludge or a mixed soil to measure the rate of mineralization of the compounds into carbon dioxide. The aliphatic compounds were mineralized more easily than the aromatic compounds. 1,4-C showed the most exceptionally slow degradation. A scrutiny of residual 1,4-C after degradation is required before polyesters containing 1,4-C could be classified into compostable because 1,4-C has detrimental effects on young radish seeds and HeLa cells and has a tendency to accumulate in the environment due to its slow degradability.

A double-blind, placebo-controlled, multicenter study of Cerebrolysin for Alzheimer's disease

OBJECTIVE

To assess the efficacy and safety of Cerebrolysin over 4 weeks in patients with probable Alzheimer's disease (AD).

DESIGN

A 4-week randomized, double-blind, placebo-controlled, multicenter clinical trial. An unequal (Cerebrolysin:placebo = 2:1) randomization was used to assign more patients to the treatment group.

SETTINGS

University medical centers and community geriatric hospitals in Korea.

PARTICIPANTS

Fifty-three men and women at least 50 years of age admitted to hospitals with mild to moderate AD and otherwise in good health.

INTERVENTION

The treatment group (n = 34) received Cerebrolysin (30 mL Cerebrolysin in 100 mL physiologic saline IV) once a day from Monday to Friday for 4 weeks. The control group (n = 19) received placebo.

MEASUREMENTS

Primary outcome measures were the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) and the Clinical Global Impression of Severity/ Change (CGIS/C). Secondary outcome measures included Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), Katz Index of Activities of Daily Living (ADL), and Lawton Instrumental Activities of Daily Living (IADL) Scale.

RESULTS

After 4 weeks of treatment, Cerebrolysin-treated patients demonstrated significant improvements in the ADAS-Cog (P = .02), CGIS/C (P = .01), and MMSE (P = .04) compared with placebo-treated patients. Among Cerebrolysin-treated patients, 82%, 62%, and 44% were rated improved on ADAS-Cog, CGIS/C, and MMSE, respectively, compared with 31.6%, 22%, and 17% of placebo-treated patients, respectively. However, there were no significant improvements in the Cerebrolysin group compared with the placebo group on the GDS, ADL, and IADL. There were no dropouts in either groups, with 100% compliance to Cerebrolysin and placebo. Only one patient reported a febrile sensation, which was transient and mild in severity.

CONCLUSIONS

This study indicates that Cerebrolysin is a safe drug that improves the cognitive deficits and global function in patients with mild to moderate AD. Long-term efficacy and safety of Cerebrolysin in Alzheimer's patients should be evaluated in the future.

Identification of a cryptic N-terminal signal in Saccharomyces cerevisiae peroxisomal citrate synthase that functions in both peroxisomal and mitochondrial targeting

Saccharomyces cerevisiae has three distinct citrate synthases, two located in mitochondria (mature Cit1p and Cit3p) and one in peroxisomes (mature Cit2p). While the precursor of the major mitochondrial enzyme, Cit1p, has a signal for mitochondrial targeting at its N-terminus (MTS), Cit2p has one for peroxisomal targeting (PTS1) at its C-terminus. We have previously shown that the N-terminal segment of Cit2p is removed during import into peroxisomes [Lee, H.S. et al. (1994) Kor. J. Microbiol. 32, 558-564], which implied the presence of an additional N-terminal sorting signal. To analyze the function of the N-terminal region of Cit2p in protein trafficking, we constructed the N-terminal domain-swapped versions of Cit1p and Cit2p. Both fusions, Cit1::Cit2 and Cit2::Cit1, complemented the glutamate auxotrophy caused by the double-disruption of the CIT1 and CIT2 genes. In addition, part of the Cit2::Cit1 fusion protein, as well as Cit1::Cit2, was shown to be transported into both mitochondria and peroxisomes. The subcellular localization of the recombinant fusion proteins containing various N-terminal segments of Cit2p fused to a mutant version of green fluorescent protein (GFP2) was also examined. As a result, we found that the 20-amino acid N-terminal segment of Cit2p contains a cryptic cleavable targeting signal for both peroxisomes and mitochondria. In addition, we show that the peroxisomal import process mediated by the N-terminal segment of Cit2p was not affected by the disruption of either PEX5 (encoding PTS1 receptor) or PEX7 (encoding PTS2 receptor).

Distinct roles for L- and T-type Ca(2+) channels in regulation of atrial ANP release

Atrial secretion of atrial natriuretic peptide (ANP) has been shown to be regulated by atrial workload. Although modulating factors for the secretion of ANP have been reported, the role for intracellular Ca(2+) on the secretion of ANP has been controversial. The purpose of the present study was to define roles for L- and T-type Ca(2+) channels in the regulation of ANP secretion in perfused beating rabbit atria. BAY K 8644 (BAY K) increased atrial stroke volume and pulse pressure. BAY K suppressed ANP secretion and ANP concentration in terms of extracellular fluid (ECF) translocation concomitantly with an increase in atrial dynamics. BAY K shifted the relationship between ANP secretion and ECF translocation downward and rightward. These results indicate that BAY K inhibits myocytic release of ANP. In the continuous presence of BAY K, diltiazem reversed the effects of BAY K. Diltiazem alone increased ANP secretion and ANP concentration along with a decrease in atrial dynamics. Diltiazem shifted relationships between ANP secretion and atrial stroke volume or ECF translocation leftward. The T-type Ca(2+) channel inhibitor mibefradil decreased atrial dynamics. Mibefradil inhibited ANP secretion and ANP concentration in contrast with the L-type Ca(2+) channel inhibitor. These results suggest that activation of L- and T-type Ca(2+) channels elicits opposite effects on atrial myocytic release of ANP.

Pharmacokinetic disposition of polyethylene glycol-modified salmon calcitonins in rats

This study first reports the pharmacokinetic disposition of polyethylene glycol (PEG)-modified salmon calcitonin (sCT) based on the number of attached PEG molecules. PEG-modified sCT was prepared by covalent linkage with succinimidyl carbonate monomethoxy polyethylene glycol. Mono- and di-PEG-sCTs were separated by size exclusion and reverse phase HPLC, and radioiodinated by the chloramine-T method with Na125I. 125I-mono-PEG sCT, 125I-di-PEG-sCT and unmodified 125I-sCT were administered to rats by i.v. injection. Serial blood samples, urine and various tissue samples were taken for the determination of radioactivity. Di-PEG-sCT exhibited significantly reduced systemic clearance (2.3 vs. 11.1 ml/min/kg) and steady-state volume of distribution (229.9 vs. 603.1 ml/kg), while mono-PEG-sCT showed a prolonged elimination half-life (189.1 min vs. 59.8 min) compared with unmodified sCT. The extent of urinary excretion of the PEG-modified sCTs was higher than for the unmodified sCT, but all these chemicals were excreted in urine in small quantities (< or = 0.6%). There was a tendency toward reduced accumulation of PEGylated sCTs in tissues, with its reduction being inversely proportional to the molecular size. Accumulation of the total radioactivity of the unmodified and PEG-modified sCTs was highest in the liver, followed by kidneys, lungs, spleen, heart and thyroid. When expressed per tissue gram weight, however, the highest radioactivity was found in the kidneys. PEGylated sCTs may have greater therapeutic potential via reduced systemic clearance and prolonged elimination half-life over unmodified sCT.

Effect of substituents on benzenesulfonyl motif of 4-phenyl-1-arylsulfonylimidazolidinones for their cytotoxicity

To explore the effect of substituents' on phenyl motif on sulfonyl function of novel anticancer 4-phenyl-1-benzenesulfonylimidazolidinones (1), electron donating or withdrawing substituents were introduced at 3 or 4-position and the analogs were tested against human lung (A549) and colon (HCT-15) cancer cell lines. Quantitative structure activity relationship of the 4-substituted series shows that only STERIMOL L values are well correlated. The increment of substituent's volume enhances the activity against both cell lines. The small substituent at 3-position additionally increases the activity. However naphthyl group in place of phenyl reduces the activity. Therefore the phenyl motif with sterically large substituent at 4-position and small substituent at 3-position may be important for their activity. Integration of these substituents' effects into the structural design led to discover the more potent analog, 4-phenyl-1-(N-acetylindoline-5-sulfonyl) imidazolidinone (1n).