Chlorhexidine and Mupirocin for Clearance of Methicillin-Resistant Staphylococcus aureus Colonization After Hospital Discharge: A Secondary Analysis of the Changing Lives by Eradicating Antibiotic Resistance Trial

BACKGROUND

The CLEAR Trial demonstrated that a multisite body decolonization regimen reduced post-discharge infection and hospitalization in methicillin-resistant Staphylococcus aureus (MRSA) carriers. Here, we describe decolonization efficacy.

METHODS

We performed a large, multicenter, randomized clinical trial of MRSA decolonization among adult patients after hospital discharge with MRSA infection or colonization. Participants were randomized 1:1 to either MRSA prevention education or education plus decolonization with topical chlorhexidine, oral chlorhexidine, and nasal mupirocin. Participants were swabbed in the nares, throat, axilla/groin, and wound (if applicable) at baseline and 1, 3, 6, and 9 months after randomization. The primary outcomes of this study are follow-up colonization differences between groups.

RESULTS

Among 2121 participants, 1058 were randomized to decolonization. By 1 month, MRSA colonization was lower in the decolonization group compared with the education-only group (odds ration [OR] = 0.44; 95% confidence interval [CI], .36-.54; P ≤ .001). A similar magnitude of reduction was seen in the nares (OR = 0.34; 95% CI, .27-.42; P < .001), throat (OR = 0.55; 95% CI, .42-.73; P < .001), and axilla/groin (OR = 0.57; 95% CI, .43-.75; P < .001). These differences persisted through month 9 except at the wound site, which had a relatively small sample size. Higher regimen adherence was associated with lower MRSA colonization (P ≤ .01).

CONCLUSIONS

In a randomized, clinical trial, a repeated post-discharge decolonization regimen for MRSA carriers reduced MRSA colonization overall and at multiple body sites. Higher treatment adherence was associated with greater reductions in MRSA colonization.

Proteomic alterations of fibroblasts induced by ovarian cancer cells reveal potential cancer targets

The common spread pattern of ovarian cancer is peritoneal implantation. The growth of the shed ovarian cancer cells in the peritoneal cavity is closely related to the tumor microenvironment. Cancer-associated fibroblasts are vital in the tumor microenvironment. It is not clearly defined that the protein expression alters during the activating process of fibroblasts. This study detected the protein alterations in fibroblasts induced by ovarian cancer cells and explored the potential biological relevance through two-dimensional gel electrophoresis and mass spectrometry. Our data showed that the level of CENPE, BAG2, SOD2, GDI2, CORO1C, CFL1, DSTN, CALD1, PHGDH, PDHA1, AKR1B1, TST and TBCA proteins were significantly up-regulated in the fibroblasts co-cultured with ovarian cancer cells, whereas HSPB1, P4HB and VIM were significantlydown-regulated. However, only BAG2, SOD2 and CORO1C proteins were confirmed to be significantly increased by western blot analysis. The differentially expressed proteins were mainly involved in metabolic processes, cellular component organization, responses to stimulus, multicellular organismal processes, localization, protein depolymerization, cellular senescence and the mitotic pathway. These data demonstrated that fibroblasts had an altered protein expression pattern after being induced by ovarian cancer cells, and participated in multiple cell processes resulting in tumor progression. The differentially expressed proteins should be considered as targets for cancer treatment.

Decolonization to Reduce Postdischarge Infection Risk among MRSA Carriers

BACKGROUND

Hospitalized patients who are colonized with methicillin-resistant Staphylococcus aureus (MRSA) are at high risk for infection after discharge.

METHODS

We conducted a multicenter, randomized, controlled trial of postdischarge hygiene education, as compared with education plus decolonization, in patients colonized with MRSA (carriers). Decolonization involved chlorhexidine mouthwash, baths or showers with chlorhexidine, and nasal mupirocin for 5 days twice per month for 6 months. Participants were followed for 1 year. The primary outcome was MRSA infection as defined according to Centers for Disease Control and Prevention (CDC) criteria. Secondary outcomes included MRSA infection determined on the basis of clinical judgment, infection from any cause, and infection-related hospitalization. All analyses were performed with the use of proportional-hazards models in the per-protocol population (all participants who underwent randomization, met the inclusion criteria, and survived beyond the recruitment hospitalization) and as-treated population (participants stratified according to adherence).

RESULTS

In the per-protocol population, MRSA infection occurred in 98 of 1063 participants (9.2%) in the education group and in 67 of 1058 (6.3%) in the decolonization group; 84.8% of the MRSA infections led to hospitalization. Infection from any cause occurred in 23.7% of the participants in the education group and 19.6% of those in the decolonization group; 85.8% of the infections led to hospitalization. The hazard of MRSA infection was significantly lower in the decolonization group than in the education group (hazard ratio, 0.70; 95% confidence interval [CI], 0.52 to 0.96; P=0.03; number needed to treat to prevent one infection, 30; 95% CI, 18 to 230); this lower hazard led to a lower risk of hospitalization due to MRSA infection (hazard ratio, 0.71; 95% CI, 0.51 to 0.99). The decolonization group had lower likelihoods of clinically judged infection from any cause (hazard ratio, 0.83; 95% CI, 0.70 to 0.99) and infection-related hospitalization (hazard ratio, 0.76; 95% CI, 0.62 to 0.93); treatment effects for secondary outcomes should be interpreted with caution owing to a lack of prespecified adjustment for multiple comparisons. In as-treated analyses, participants in the decolonization group who adhered fully to the regimen had 44% fewer MRSA infections than the education group (hazard ratio, 0.56; 95% CI, 0.36 to 0.86) and had 40% fewer infections from any cause (hazard ratio, 0.60; 95% CI, 0.46 to 0.78). Side effects (all mild) occurred in 4.2% of the participants.

CONCLUSIONS

Postdischarge MRSA decolonization with chlorhexidine and mupirocin led to a 30% lower risk of MRSA infection than education alone. (Funded by the AHRQ Healthcare-Associated Infections Program and others; ClinicalTrials.gov number, NCT01209234 .).

Transition care readiness among patients in a tertiary paediatric department

INTRODUCTION

A smooth transition of healthcare for young people with chronic illnesses from paediatric to adult healthcare services is important to ensure optimal outcome. At the moment, there are no standard guidelines to assess a patient's readiness to transfer care.

METHODS

A cross-sectional study using a self-administered questionnaire, adapted from UNC (University of North Carolina) TRxANSITION self-assessment tool was conducted to evaluate patients' transition care readiness in paediatric haematology and paediatric diabetes clinic.

RESULTS

A total of 80 patients (37 thalassaemia and 43 diabetes) with the mean age of 21.2 (SD±4.3) years, were recruited during the 3-month study period. Majority of the patients have basic knowledge regarding their medications, and were able to comply with their follow-up. The mean total score obtained by the respondents on this questionnaire was 15.3 (SD±3.59). Self-management skills and knowledge on disease were the two poorly scored section; with mean score of 3.78 (SD±1.38) and 4.28 (SD±1.20) respectively. Overall, only 21 (26.2%) respondents obtained high score (score above 75th percentile). Seventy-five percent of the respondents admitted that they were not ready for transfer to an adult healthcare service yet at the time of the study.

CONCLUSION

We suggest that patients with high score should be prepared for transition to adult facility whereas those with a low score need to be identified to ensure provision of continuous education.

Antimelanogenic effects of luteolin 7-sulfate isolated from Phyllospadix iwatensis Makino

BACKGROUND

Abnormal deposition of melanin may cause an aesthetic skin problem; therefore, the control of unwanted excessive melanin synthesis is the major goal of cosmetic research.

OBJECTIVES

To identify novel tyrosinase (TYR) inhibitors from marine plants and examine their cellular antimelanogenic effects.

METHODS

The extracts of 50 marine plants endemic to Korea were screened against human TYR. Active constituents were then isolated from the selected plant extracts that showed potential and their chemical structures elucidated. Furthermore, their antimelanogenic effects were examined using murine melanoma B16/F10 cells and human epidermal melanocytes (HEM).

RESULTS

Among the tested extracts, that of Phyllospadix iwatensis Makino exhibited the strongest human TYR inhibitory activity. The active constituents were purified from the butanol fraction of the P. iwatensis extract and identified as hispidulin 7-sulfate and luteolin 7-sulfate. Luteolin 7-sulfate inhibited human TYR more strongly than hispidulin 7-sulfate, luteolin, hispidulin and arbutin. Furthermore, luteolin 7-sulfate showed lower cytotoxicity than luteolin in both B16/F10 cells and HEM. Luteolin 7-sulfate attenuated cellular melanin synthesis more effectively in B16/F10 cells and HEM stimulated by α-melanocyte-stimulating hormone and l-tyrosine than arbutin.

CONCLUSIONS

This study demonstrates that luteolin 7-sulfate isolated from P. iwatensis is a human TYR inhibitor with advantageous antimelanogenic properties, and would be useful for development as a therapeutic agent for the control of unwanted skin pigmentation.

Pelvic congestion syndrome diagnosed using endoscopic ultrasonography

Pelvic congestion syndrome (PCS) presents with a non-cyclic pelvic pain lasting more than six months in duration in premenopausal women. Pelvic ultrasonography or computed tomography is usually the first imaging modality used to evaluate patients with suspected PCS. PCS is confirmed by visible congestion of the pelvic veins on selective ovarian venography. To our knowledge, the role of endoscopic ultrasonography (EUS) has not been reported. EUS showed multiple dilated structures especially on left side around the uterus and ovaries, which are compatible with other radiological investigations of PCS Although PCS is not typical areas within the scope of practice of endosonographers, it is useful to be familiar with the findings. We report a case of PCS that was diagnosed with the aid of EUS.

A carcinoid tumour arising within a tailgut cyst: a diagnostic challenge

A 49-year-old man was referred with constipation that had lasted for a few months. On colonoscopy, a subepithelial tumour more than 4 cm in size was seen in the rectum. He underwent endoscopic ultrasound and pelvic magnetic resonance imaging. He was preoperatively diagnosed with a rectal duplication cyst based on imaging studies. However, the final histopathologic diagnosis after transanal excision of the rectal mass was rectal carcinoid tumour with tailgut cyst. Tailgut cysts are very rare congenital lesions in the presacral area and are most often discovered incidentally in middle-aged women. It is difficult to distinguish the imaging appearance of tailgut cysts from that of many other retrorectal cysts. Malignant transformation of tailgut cysts has been estimated to occur in 2 to 13% of cases. We report the diagnostic difficulties encountered in a case of carcinoid tumour arising from a tailgut cyst in a male patient.

Gadoxetic acid-enhanced MRI for T-staging of gallbladder carcinoma: emphasis on liver invasion

OBJECTIVE

To evaluate the diagnostic performance of gadoxetic acid-enhanced MRI with an emphasis on the usefulness of the hepatobiliary phase (HBP) in T-staging of gallbladder carcinoma.

METHODS

66 patients with surgically confirmed gallbladder carcinoma underwent MRI. Two radiologists independently reviewed two sets of gadoxetic acid-enhanced MRI without and with the HBP. Local tumour spread was evaluated according to T-staging, and the results were compared with pathological findings. The diagnostic performance of two image sets to differentiate each T-stage was compared.

RESULTS

The sensitivities of MRI with the HBP to differentiate T1 vs ≥ T2 lesions, ≤ T2 vs ≥ T3 lesions and ≤ T3 vs T4 lesions were 96.3%, 85.7% and 100% for Observer 1 and 92.6%, 95.2% and 100% for Observer 2, respectively (p<0.0001). By adding the HBP, the sensitivities to differentiate ≤ T2 vs ≥ T3 lesions were increased from 66.7% to 85.7% for Observer 1 and from 81.0% to 95.2% for Observer 2, although there was no significant difference (p>0.05). The overall accuracies for T-staging were increased from 80.3% to 86.4% for Observer 1, a statistically significant degree (p=0.046), and from 83.8% to 87.9% for Observer 2 (p>0.05). The k-value for the two observers indicated excellent agreement.

CONCLUSION

Gadoxetic acid-enhanced MRI provided acceptable diagnostic performance for T-staging of gallbladder carcinoma. Addition of the HBP aids in the detection of liver invasion.

ADVANCES IN KNOWLEDGE

In the T-staging of gallbladder carcinoma, gadoxetic acid-enhanced MRI with the HBP may enhance detection of liver invasion.

Development of a new dynamic gas flow-control system in the pressure range of 1 Pa-133 Pa

A new flow-control system (FCS-705) has been developed at Korea Research Institute of Standards and Science. The system is intended for calibration of vacuum gauges in the pressure range of 1 Pa-133 Pa by comparison method. This paper describes some basic characteristics of the system including; (1) the design and construction of the system, (2) the generation of stable pressures in the chamber, (3) achieving high upstream pressure limit by installing a short duct in the by-pass pumping line, and (4) investigation of the gas flow regimes within the short duct.

Correlation of the apparent diffusion coefficiency values on diffusion-weighted imaging with prognostic factors for breast cancer

OBJECTIVE

The aim of this study was to correlate the apparent diffusion coefficient (ADC) value of breast cancer with prognostic factors.

METHODS

335 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) and ductal carcinoma in situ (DCIS) who underwent breast MRI with diffusion-weighted imaging were included in this study. ADC of breast cancer was calculated using two b factors (0 and 1000 s mm(-2)). Mean ADCs of IDC NOS and DCIS were compared and evaluated. Among cases of IDC NOS, mean ADCs were compared with lymph node status, size and immunochemical prognostic factors using Student's t-test. ADC was also correlated with histological grade using the Kruskal-Wallis test.

RESULTS

Mean ADC of IDC NOS was significantly lower than that of DCIS (p<0.001). However, the mean ADC of histological grade of IDC NOS was not significantly different (p=0.564). Mean ADC of oestrogen receptor (ER)-positive or progesterone receptor (PR)-positive cancer was significantly lower than that of ER-negative or PR-negative cancer (p=0.003 vs p=0.032). Mean ADC of Ki-67 index-positive cancer was significantly lower than that of Ki-67 index-negative cancer (p=0.028). Mean ADC values of cancers with increased microvascular density (MVD) were significantly lower than those of cancer with no MVD increase (p=0.009). No correlations were observed between mean ADC value and human growth factor receptor 2 expression, tumour size and lymph node metastasis.

CONCLUSION

Low ADC value was correlated with positive expression of ER, PR, increased Ki-67 index, and increased MVD of breast cancer.

The study of new vacuum pressure measurement technique using ultrasonic acoustic impedance transducers

Ultrasonic sensors of 500 kHz frequency have been used to study the measuring of gas pressure in the range 1.33 × 10(3)-2.026 × 10(5) Pa. From the experimental data it was observed that amplitude of the transmitted ultrasound was dependent on gas pressure. The results confirm that by using appropriate instruments including sensors and electronic devices, pressure of the gas can be successfully measured by measuring the magnitude of the received signal. The proposed method is expected to be applied to develop as new vacuum pressure measurement instrument.

Influence of chimeric human-bovine fibers on adenoviral uptake by liver cells and the antiviral immune response

Human adenoviruses (HAdV) are widely used for in vitro and in vivo gene transfer. Viral hepatotropism, inflammatory responses and neutralization by pre-existing antibodies (NAbs) are obstacles for clinical applications of HAdV vectors. Although the multifactorial events leading to innate HAdV toxicity are far from being elucidated, there is a consensus that the majority of intravenously injected-HAdV vectors is sequestered by Kuppfer cells, probably independently of coagulation factors. In this study, we show that the adenoviral-associated humoral and innate cytokine immune responses are significantly reduced when HAdV-5 vector carrying human bovine chimeric fibers (HAdV-5-F2/BAdV-4) is intravenously injected into mice. Fiber pseudotyping modified its interaction with blood coagulation factors, as FIX and FX no longer mediate the infection of liver cells by HAdV-5-F2/BAdV-4. As a consequence, at early time points post-infection, several cytokines and chemokines (IFN-gamma, IL-6, IP-10, MCP-1, RANTES and MP1beta) were found to be present at lower levels in the plasma of mice that had been intravenously injected with HAdV-5-F2/BAdV-4 compared with mice injected with the parental vector HAdV-5. Moreover, genetic modification of the fiber allowed HAdV-5-F2/BAdV-4 to partially escape neutralization by NAbs.

Adenovirus 5 vector genetically re-targeted by an Affibody molecule with specificity for tumor antigen HER2/neu

In order to use adenovirus (Ad) type 5 (Ad5) for cancer gene therapy, Ad needs to be de-targeted from its native receptors and re-targeted to a tumor antigen. A limiting factor for this has been to find a ligand that (i) binds a relevant target, (ii) is able to fold correctly in the reducing environment of the cytoplasm and (iii) when incorporated at an optimal position on the virion results in a virus with a low physical particle to plaque-forming units ratio to diminish the viral load to be administered to a future patient. Here, we present a solution to these problems by producing a genetically re-targeted Ad with a tandem repeat of the HER2/neu reactive Affibody molecule (ZH) in the HI-loop of a Coxsackie B virus and Ad receptor (CAR) binding ablated fiber genetically modified to contain sequences for flexible linkers between the ZH and the knob sequences. ZH is an Affibody molecule specific for the extracellular domain of human epidermal growth factor receptor 2 (HER2/neu) that is overexpressed in inter alia breast and ovarian carcinomas. The virus presented here exhibits near wild-type growth characteristics, infects cells via HER2/neu instead of CAR and represents an important step toward the development of genetically re-targeted adenoviruses with clinical relevance.

Early gastric cancer: virtual gastroscopy

Gastric cancer is one of the most common cancers and one of the most frequent causes of cancer-related deaths worldwide. Early detection and accurate preoperative staging of early gastric cancer (ECG) offers the best prognosis and is essential for planning optimal therapy such as endoscopic mucosal resection or gastric resection. Recent advances in computed tomographic technology and three-dimensional imaging software have enabled more accurate gastric imaging. Virtual gastroscopy (VG) is helpful in the detection and evaluation of EGC in the same way as gastroscopy. VG has a wider field of view than conventional gastroscopy, the angle of the virtual cancer can be adjusted omnidirectionally, and it has no blind point because retrospective reconstruction is available. Thus, VG is a promising method for evaluating gastric lesions despite its limitations. This report describes the clinical usefulness of VG with multidetector row computed tomography for EGC and axial computed tomography.

Tumor cell targeted gene delivery by adenovirus 5 vectors carrying knobless fibers with antibody-binding domains

Most human carcinoma cell lines lack the high-affinity receptors for adenovirus serotype 5 (Ad5) at their surface and are nonpermissive to Ad5. We therefore tested the efficiency of retargeting Ad5 to alternative cellular receptors via immunoglobulin (Ig)-binding domains inserted at the extremity of short-shafted, knobless fibers. The two recombinant Ad5's constructed, Ad5/R7-Z(wt)-Z(wt) and Ad5/R7-C2-C2, carried tandem Ig-binding domains from Staphylococcal protein A (abbreviated Z(wt)) and from Streptococcal protein G (C2), respectively. Both viruses bound their specific Ig isotypes with the expected affinity. They transduced human carcinoma cells independently of the CAR pathway, via cell surface receptors targeted by specific monoclonal antibodies, that is, EGF-R on A549, HT29 and SW1116, HER-2/neu on SK-OV-3 and SK-BR-3, CA242 (epitope recognized by the monoclonal antibody C242) antigen on HT29 and SW1116, and PSMA (prostate-specific membrane antigen) expressed on HEK-293 cells, respectively. However, Colo201 and Colo205 cells were neither transduced by targeting CA242 or EGF-R nor were LNCaP cells transduced by targeting PSMA. Our results suggested that one given surface receptor could mediate transduction of certain cells but not others, indicating that factors and steps other than cell surface expression and virus-receptor interaction are additional determinants of Ad5-mediated transduction of tumor cells. Using penton base RGD mutants, we found that one of these limiting steps was virus endocytosis.

Genetic modification of adenovirus 5 tropism by a novel class of ligands based on a three-helix bundle scaffold derived from staphylococcal protein A

The use of adenovirus (Ad) as an efficient and versatile vector for in vivo tumor therapy requires the modulation of its cellular tropism. We previously developed a method to genetically alter the tropism of Ad5 fibers by replacing the fiber knob domain by an extrinsic trimerization motif and a new cellular ligand. However, fibers carrying complex ligands such as single-chain antibody fragments did not assemble into functional pentons in vitro in the presence of penton base, and failed to be rescued into infectious virions because of their inability to fold correctly within the cytoplasm of Ad-infected cells. Here we show that the coding sequence for a disulfide bond-independent three-helix bundle scaffold Z, derived from domain B of Staphylococcal protein A and capable of binding to the Fc portion of immunoglobulin (Ig) G1, could be incorporated into modified knobless Ad fiber gene constructs with seven shaft repeats. These fiber gene constructs could be rescued into viable virions that were demonstrated to enter 293 cells engineered for IgG Fc surface expression but not unmodified 293 cells, via a mechanism that could be specifically blocked with soluble Fc target protein. However, the tropism modified viruses showed a slightly impaired cellular entry and a lower infectivity than wildtype (WT) virus. In addition, we generated recombinant fibers containing an IgA binding Affibody ligand, derived from combinatorial specificity-engineering of the Z domain scaffold. Such fiber constructs also showed the expected target specific binding, indicating that the affibody protein class is ideally suited for genetic engineering of Ad tropism.

Synthesis and .alpha.-adrenergic activities of 2- and 4-substituted imidazoline and imidazole analogs

Seven analogues of medetomidine and naphazoline were synthesized and evaluated for their alpha 1 (aorta) and alpha 2 (platelet) activities. The analogues were composed of 2- and 4-substituted imidazoles and imidazolines attached through a methylene bridge to either the 1- or 2-naphthalene ring system. In general the 1-naphthalene analogues were the most potent inhibitors of epinephrine-induced platelet aggregation. Of considerable interest was the fact that the 1-naphthalene analogues (2, 5-7) were partial agonists while the 2-naphthalene analogues (3, 8, 9) were antagonists in an alpha 1-adrenergic system (aorta). Thus, appropriately substituted naphthalene analogues of medetomidine and naphthazoline provide a spectrum of alpha 1-agonist, alpha 1-antagonist, and alpha 2-antagonist activity.

Discriminative stimulus properties of alpha-ethyltryptamine optical isomers

alpha-Ethyltryptamine (alpha-ET) possesses central stimulant and hallucinogenic activity. Also, in tests of stimulus generalization using rats trained to discriminate the controlled substance analog (i.e., designer drug) N-methyl-1-(3,4-methylenedioxyphenyl)-2-aminopropane (MDMA) from vehicle, alpha-ET substituted for MDMA. These previous studies employed racemic alpha-ET. Because psychoactive phenylalkylamines with abuse potential can produce one or more of three distinct stimulus effects (i.e., amphetamine-, DOM- and/or PMMA-like effects) in animals trained to discriminate either the stimulant (+)amphetamine, the hallucinogen 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM), or N-methyl-1-(4-methoxyphenyl)-2-aminopropane (PMMA) from vehicle, and because these effects can be stereoselective, the individual optical isomers of alpha-ET were examined in groups of animals trained to discriminate (+)amphetamine, DOM, PMMA and MDMA from saline vehicle. (-)alpha-ET (ED(50)=7.8 mg/kg), but not (+)alpha-ET (maximum of 53% drug-appropriate responding), substituted for (+)amphetamine, whereas (+)alpha-ET (ED(50)=2.7 mg/kg), but not (-)alpha-ET (maximum of 33% drug-appropriate responding), substituted for DOM. Both optical isomers of alpha-ET substituted for PMMA and MDMA with ED(50) values of 1.6 and 1.4 mg/kg (PMMA-trained animals) and 1.3 and 2.0 mg/kg (MDMA-trained animals) for (-)alpha-ET and (+)alpha-ET, respectively. The results of this investigation suggest that both optical isomers of alpha-ET are capable of producing an MDMA/PMMA-like effect at nearly comparable doses, and that the stimulant or amphetamine-like nature of alpha-ET resides primarily with its (-)isomer whereas hallucinogenic or DOM-like character resides primarily with the (+)enantiomer.

A large-scale purification of recombinant histone H1.5 from Escherichia coli

An Escherichia coli expression system has been constructed for production of biologically active recombinant histone H1.5. A process of fermentation and purification method at a large scale has been developed. Recombinant histone H1.5 was released from the high density cultured cells by high-pressure homogenization. For an efficient removal of cell debris and partial purification of basic histone H1.5 in a single step, the whole cell lysates were directly loaded onto an expanded bed column packed with the strong cation exchanger (Streamline SP). Complete removal of various impurities was achieved by a combination of hydroxyapatite chromatography and the following cation exchange chromatography with high grade strong cation exchanger (POROS 20 HS), and finally endotoxins were removed by ultrafiltration using a 100-kDa cut-off membrane, which gave the level of endotoxin below 0.5 EU/mg. The molecular mass of the recombinant histone H1.5 analyzed by MALDI-TOF-MS, and the N-terminal amino acid sequences were in good agreement with the authentic histone H1.5. The whole process gave highly purified recombinant histone H1.5 at a high yield, compared to the conventional process.

Genetic retargeting of adenovirus: novel strategy employing "deknobbing" of the fiber

For efficient and versatile use of adenovirus (Ad) as an in vivo gene therapy vector, modulation of the viral tropism is highly desirable. In this study, a novel method to genetically alter the Ad fiber tropism is described. The knob and the last 15 shaft repeats of the fiber gene were deleted and replaced with an external trimerization motif and a new cell-binding ligand, in this case the integrin-binding motif RGD. The corresponding recombinant fiber retained the basic biological functions of the natural fiber, i.e., trimerization, nuclear import, penton formation, and ligand binding. The recombinant fiber bound to integrins but failed to react with antiknob antibody. For virus production, the recombinant fiber gene was rescued into the Ad genome at the exact position of the wild-type (WT) fiber to make use of the native regulation of fiber expression. The recombinant virus Ad5/FibR7-RGD yielded plaques on 293 cells, but the spread through the monolayer was two to three times delayed compared to WT, and the ratio of infectious to physical particles was 20 times lower. Studies on virus tropism showed that Ad5/FibR7-RGD was able to infect cells which did not express the coxsackie-adenovirus receptor (CAR), but did express integrins. Ad5/FibR7-RGD virus infectivity was unchanged in the presence of antiknob antibody, which neutralized the WT virus. Ad5/FibR7-RGD virus showed an expanded tropism, which is useful when gene transfer to cells not expressing CAR is needed. The described method should also make possible the construction of Ad genetically retargeted via ligands other than RGD.

A simple method for the purification of an antimicrobial peptide in recombinant Escherichia coli

A magainin derivative, designated MSI-344, was produced in Escherichia coli as fusion protein, by utilizing a truncated amidophsphoribosyltransferase of E. coli as a fusion partner. Bacterial cells transformed with the gene encoding the fusion protein were grown to a high cell density and induced with isopropyl-1-thio-b-D-galatoside (IPTG) to initiate product expression. The fusion protein was accumulated into cytoplasmic inclusion body and recombinant MSI-344 was released from the fusion partner by hydroxylamine treatment. Following cleavage of the fusion protein with hydroxylamine, the released MSI-344 was purified to homogeneity by cationic exchange chromatography. The final purity was at least 95% by reversed-phase high performance liquid chromatography (RP-HPLC). Purified recombinant MSI-344 was found to be indistinguishable from the synthetic peptide determined by amino acid sequences and antimicrobial activity assay.

Immunoreactive domains and integrin-binding motifs in adenovirus penton base capsomer

A panel of nine independent mouse monoclonal antibodies (MAbs) against penton base capsomers of subgenus C adenovirus serotypes 2 (Ad2) and 5 (Ad5) were isolated and characterized. Two of them (1D2 and 5A5), raised against Ad5 virion as the immunogen, bound to sodium dodecyl sulfate (SDS)-resistant and subgenus C-specific epitopes that were not present in subgenus B Ad3 penton base. The 1D2 and 5A5 epitopes were mapped to two distinct regions that did not belong to the main variable region carrying the integrin-binding RGD motif at position 340. For the other seven MAbs, raised against recombinant Ad2 penton base protein (9S-pentamers), the epitopes were sensitive to SDS-denaturation, but reacted with native Ad2, Ad5, and Ad3 penton base. The epitopes recognized by the nine MAbs and by polyclonal antipenton base antibodies defined three major immunoreactive regions. One (I) mapped to the N-terminal domain (residues 116-165); the other two regions were almost symmetrically disposed on both sides of the integrin-binding RGD motif at position 340, within residues 248-270 (II), and within residues 368-427 (III) in the C-terminal domain. Region II overlapped the fiber-binding site in penton base (residues 254-260). None of the MAbs showed any detectable virus neutralization effect, but they all slightly augmented the efficiency of Ad-mediated gene transfer. Although none of their epitopes included the RGD-340 tripeptide, substitutions of the arginine residue in the RGD motif abolished the reactivity of six individual and distant epitopes, suggesting a major conformational role for the RGD-containing domain.

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.

Polymorphic DNA haplotypes at the human low-density lipoprotein receptor gene locus in Koreans

Many low-density lipoprotein (LDL) receptor mutations have been identified and characterized, demonstrating a high degree of allelic heterogeneity at this locus. The ability to identify mutant LDL-receptor genes for prenatal diagnosis of familial hypercholesterolemia (FH) or to study the role of the LDL-receptor gene in polygenic hypercholesterolemia requires the use of closely linked restriction fragment lenghth polymorphisms (RFLPs). In the present study nine different RFLPs (TaqI, StuI, HincII, BstEII, AvaII, PvuII, MspIA, MspIB, and NcoI) and a sequence variation at Arg450 were used to clarify the characteristics of the LDL-receptor gene in Koreans. A total of 978 LDL-receptor alleles from 244 members of 43 different pedigrees (15 normal and 28 FH pedigrees) and 245 individuals (187 normal and 58 FH) were analyzed. Frequencies of these polymorphisms did not differ significantly between controls and FH patients. Individually, seven sites--TaqI, BstEII, AvaII, MspIA, MspIB, NcoI and Arg450--had heterozygosity indices ranging from 0.3610 to 0.4601, whereas the PvuII site displayed low levels of polymorphism and StuI was monomorphic. Haplotypes were constructed for 215 individuals of 13 normal and 24 FH pedigrees using the nine polymorphisms. Of 512 (= 2(9)) possible combinations for the nine polymorphic sites, 39 unique haplotypes were detected. The frequency distribution of individual haplotypes ranged from 1/155 (0.65%) to 40/155 (25.8%). The four most common haplotypes accounted for 59.4% of those sampled. Statistical analysis of the haplotypes indicated marked linkage disequilibrium for these 10 sites and throughout the region containing the LDL-receptor gene. Owing to the high degree of linkage disequilibrium over the entire locus, not all RFLPs were informative. We rank each RFLP according to its informativeness and present a strategy for the optimal selection of RFLPs for pedigree analysis.

Cryopreservation of Taxus chinensis suspension cell cultures

A simple cryopreservation method for suspension cells of Taxus chinensis was established. In this procedure 7 days old suspension cells were used without any pre-culture treatment. At first, cells were incubated in cryoprotectant solution (0.5M DMSO and 0.5M glycerol) on ice for 30 min and then frozen at a cooling rate of 1 degree C/min to -40 degrees C prior to immersion in liquid nitrogen. The average viability of frozen-thawed cells was between 30 to 40%. The recovery of cryopreserved cells in liquid nitrogen for 1 month was accomplished. After rapid thawing, cells were transferred to solid medium and cultivated for 4-6 weeks. The treatment of trehalose as a cryoprotectant enhanced re-growth of frozen-thawed cells. The stable maintenance of paclitaxel biosynthetic ability in cryopreserved cells was confirmed by comparing with that of regularly sub-cultured suspension cells.

Biochemical activities of trimetoquinol analogs at human beta(1)- and beta(3)-adrenergic receptors

The biochemical activities of trimetoquinol (TMQ) analogs were evaluated at the human beta(1)- and beta(3)-adrenergic receptor (AR) subtypes expressed in Chinese hamster ovary cells. In radioligand binding assays, the 1-benzyl iodine-substituted analogs exhibited higher binding affinities at both beta(1)- and beta(3)-AR subtype as compared to TMQ. In cAMP accumulation assays, these analogs exhibited high potencies at both beta(1)- and beta(3)-AR. The 3',5'-diiodo-4'-amino analog of TMQ was the most potent beta(3)-AR agonist, 17-fold more potent at the beta(3)-AR versus the beta(1)-AR. Masking of the 6,7-dihydroxy group of the catechol ring of 3',5'-diiodo-4'-acetamido analog of TMQ, a potent beta(1)- and beta(3)-AR agonist, abolished activity at both beta-AR subtypes. Furthermore, substitution of a strong electron withdrawing group such as the trifluoromethyl moiety at the 1-benzyl ring of TMQ dramatically decreased potency at beta(1)- and beta(3)-AR compared to TMQ. Replacement of the 1-benzyl ring of TMQ with a naphthalene ring did not alter affinity but reduced potency of resulting 1-naphthylmethyl and 2-naphthylmethyl analogs at beta(1)- and beta(3)-AR compared to TMQ. Our results define the structural and electronic properties of substituents on TMQ necessary for potent activation of beta(1)- and beta(3)-AR and suggest that further modifications of the 1-benzyl iodine-substituted analogs may yield potent beta(3)-AR agonists.

High-level expression of antimicrobial peptide mediated by a fusion partner reinforcing formation of inclusion bodies

A gene expression system for antimicrobial peptides, which could be effectively used for various studies or applications of the antimicrobial peptides, has been developed. To avoid the harmful effects on an expression host, Escherichia coli, the antimicrobial peptides were expressed as fusion proteins with a polypeptide F4, which is a truncated PurF fragment that highly tends to form inclusion bodies. Seven different kinds of antimicrobial peptides have been successfully expressed by this expression system and the resulting expression level of fusion proteins reached up to 30% of total cell proteins. To confirm the identity of the recombinant peptide, MSI-344 was selected as a model peptide and purified to homogeneity, and we could obtain the recombinant MSI-344 of a high purity and with a good yield, which was identical to the authentic peptide in the aspects of the chemical and antimicrobial properties. These results show that the neutral fusion partner, which reinforces the formation of inclusion bodies, could mediate a high-level expression of the antimicrobial peptides.

Canine adenovirus type 2 attachment and internalization: coxsackievirus-adenovirus receptor, alternative receptors, and an RGD-independent pathway

The best-characterized receptors for adenoviruses (Ads) are the coxsackievirus-Ad receptor (CAR) and integrins alpha(v)beta(5) and alpha(v)beta(3), which facilitate entry. The alpha(v) integrins recognize an Arg-Gly-Asp (RGD) motif found in some extracellular matrix proteins and in the penton base in most human Ads. Using a canine adenovirus type 2 (CAV-2) vector, we found that CHO cells that express CAR but not wild-type CHO cells are susceptible to CAV-2 transduction. Cells expressing alpha(M)beta(2) integrins or major histocompatibility complex class I (MHC-I) molecules but which do not express CAR were not transduced. Binding assays showed that CAV-2 attaches to a recombinant soluble form of CAR and that Ad type 5 (Ad5) fiber, penton base, and an anti-CAR antibody partially blocked attachment. Using fluorescently labeled CAV-2 particles, we found that in some cells nonpermissive for transduction, inhibition was at the point of internalization and not attachment. The transduction efficiency of CAV-2, which lacks an RGD motif, surprisingly mimicked that of Ad5 when tested in cells selectively expressing alpha(v)beta(5) and alpha(v)beta(3) integrins. Our results demonstrate that CAV-2 transduction is augmented by CAR and possibly by alpha(v)beta(5), though transduction can be CAR and alpha(v)beta(3/5) independent but is alpha(M)beta(2), MHC-I, and RGD independent, demonstrating a transduction mechanism which is distinct from that of Ad2/5.

Synthesis and in vitro cytotoxicity of 2-alkylaminosubstituted quinoline derivatives

Eight 2-alkylaminosubstituted 5,8-dimethoxy-4-methylquinolines and nine 2-alkylaminosubstituted or 2,6-disubstituted 4-methylquinoline-5,8-diones were synthesized and evaluated in vitro cytotoxicity against four human cancer cell lines (HOP62, SK-OV-3, HCT15 and SF295).

First Report of Occurrence of Eggplant Wilt Caused by Verticillium dahliae in Korea

A wilt disease occurred on greenhouse-grown eggplants (Solanum melongena L.) at Hanam and Yeojoo, Korea, in 1997. Lower leaves on the 2-month-old wilted eggplants exhibited gradual yellowing, interveinal necrosis, and marginal crinkling and dropped prematurely. Vascular tissues of diseased stems were discolored and turned black. Vertical sections of the stems revealed that the pith had been colonized by the fungus. The disease progressed from lower parts of the plants upward. Incidence of diseased eggplants in greenhouses was 5% on 23 May 1997. Although the incidence increased to 10% on 13 June, it remained constant through early July. Fungal isolates from discolored vascular tissues were initially whitish to cream color on potato-dextrose agar, which turned black due to the formation of microsclerotia. The fungus also produced abundant verticillate conidiophores with phialides and conidia. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium dahliae Klebahn. Pathogenicity tests by root cutting, root dipping, or soil drenching resulted in similar symptoms observed in the naturally infected eggplants. Symptoms were first observed on lower leaves of each eggplant 3 weeks after inoculation. Isolation from symptomatic leaves of the inoculated eggplants yielded V. dahliae. This is the first report of occurrence of Verticillium wilt of eggplant in Korea.

Regulation of Gadd45gamma expression by C/EBP

The Gadd45gamma (growth arrest and DNA damage-inducible) gene is activated transcriptionally by at least two kinds of agents: DNA damaging agent such as methyl methanesulfonate (MMS) and UV radiation, or cytokines such as interleukin (IL)-6, IL-2 and granulocyte colony-stimulating factor (G-CSF). To investigate the sequences and transcription factors involved in induction of Gadd45gamma after treatment with IL-6, the human gene was cloned and sequenced. We found C/EBP (CCAAT/enhancer-binding protein) family proteins, major transcription factors in the IL-6 signal transduction pathway, could regulate the transcriptional activity of the Gadd45gamma promoter. In addition, a noncanonical C/EBP-binding site within the Gadd45gamma promoter where C/EBPbeta and C/EBPdelta could bind, was identified by electrophoretic mobility shift assay (EMSA) and reporter gene analysis. Furthermore, we found a coordinated expression profile between Gadd45gamma mRNA and C/EBPs (beta and delta) protein during the differentiation of M1 cells: the amount of Gadd45gamma transcripts became maximal when both C/EBPbeta and C/EBPdelta levels were high, on day 1 of differentiation of M1 cells after treatment with IL-6. These findings suggest that mitotic growth arrest coupled to M1 cell differentiation is mediated by C/EBPs stimulation of growth arrest-associated genes such as Gadd45gamma.

Characterization and cDNA cloning of two glycine- and histidine-rich antimicrobial peptides from the roots of shepherd's purse, Capsella bursa-pastoris

Two novel antimicrobial peptides were isolated and characterized from the roots of shepherd's purse, Capsella bursa-pastoris. These antimicrobial peptides, named shepherin I and shepherin II, consist of 28 and 38 amino acids, respectively, and are glycine- and histidine-rich peptides. Shepherin I and shepherin II have 67.9% and 65.8% (mol/mol) glycine, respectively, and 28.6% and 21.1% (mol/mol) histidine, respectively. Both shepherins have a Gly-Gly-His motif. These antimicrobial peptides exhibit antimicrobial activity against Gram-negative bacteria and fungi. Circular dichroism spectra of shepherin I and shepherin II showed that shepherin I and shepherin II in 50% trifluoroethanol have 66.7% and 75% random coils, respectively, without any alpha-helices. cDNA sequence analysis revealed that shepherin I and shepherin II are produced from a single polypeptide, designated shep-GRP, consisting of 120 amino acids; shep-GRP has five distinct domains, an amino-terminal putative signal peptide, a shepherin I, a linker dipeptide, a shepherin II and a carboxy-terminal peptide. Southern blot analysis indicates that the gene encoding shepherins belongs to a low-complexity gene family. Northern blot analysis revealed that transcripts of shep-GRP are present in roots but not in leaves and stems.

Functional impairment of sinusoidal membrane transport of organic cations in rats with CCl4-induced hepatic failure

PURPOSE

The effect of CCl4-induced experimental hepatic failure (EHF) on the sequential hepatobiliary transport of model organic cations (OCs), triethylmethylammonium (TEMA), and tributylmethylammonium (TBuMA), was investigated in rats.

METHODS

EHF was induced by an i.p. injection of CCl4 at a dose of 1 ml/kg 24 hr prior to the transport study. The cumulative in vivo biliary excretion, in vitro hepatic uptake by isolated hepatocytes, in vitro efflux (i.e., release) from hepatocytes, and in vivo hepatobiliary excretion clearance were measured for normal and CCl4-EHF rats.

RESULTS

The CCl4-EHF decreased the apparent in vivo biliary clearance (CL(b)) and the in vitro maximum uptake rate (Vmax, uptake) of TBuMA by 66 and 48%, respectively. The CCl4-EHF had no effect on the CL(b) of TEMA. but decreased both the Vmax, uptake (59%) and the in vitro maximum hepatic efflux rate (Vmax, efflux) of TEMA (80%). On the contrary, the CCl4-EHF had no influence on the in vivo hepatobiliary excretion clearance (CL(exc)) of both OCs.

CONCLUSIONS

Transport systems for the OCs on the sinusoidal membrane (uptake and/or efflux), rather than those on the bile canalicular membrane (excretion) appear to be prone to damage by the CC14-EHF.

Gadd45 family proteins are coactivators of nuclear hormone receptors

Gadd45 family genes encode nuclear acidic proteins composed of Gadd45, MyD118, and CR6. Sequence analysis showed that Gadd45 family proteins (Gadd45, MyD118, and CR6) contain LXXLL signature motifs considered necessary and sufficient for the binding of several coactivators to nuclear receptors. Interaction between Gadd45 or CR6 and RXR alpha was confirmed by a two-hybrid test in yeast. Results from a series of GST pulldown assays showed that these Gadd45 family proteins interact with several nuclear hormone receptors including RXR alpha, RAR alpha, ER alpha, PPAR alpha, PPAR beta, and PPAR gamma2 in vitro. Interaction between Gadd45 family proteins and nuclear hormone receptors resulted in modest activation of transactivating function of nuclear hormone receptors in reporter systems. When fused to DNA binding domain of GAL4, Gadd45 and CR6 activated the UAS-mediated transcription in mammalian cells. These results suggest that Gadd45 family proteins bind to nuclear hormone receptors and act as nuclear coactivators.

Enhancement of adenovirus-mediated gene delivery by use of an oligopeptide with dual binding specificity

The efficiency of human adenovirus serotype 5 (Ad5) transgene delivery was tested on several human and animal cell lines in vitro, by using a bimodular 35-mer oligopeptide carrying two peptide domains with different ligand specificities. One domain mimicked the fiber knob-binding region of the alpha2 domain of human MHC-1 molecules (MH20), and the other corresponded to the gastrin-releasing peptide (GRP). Two synthetic peptides with different configurations were analyzed in Ad-mediated gene transfer assays using Ad5Luc3 vector carrying the luciferase reporter gene. One peptide (GRP-MH20) had the GRP domain on the N-terminal side of MH20, while the other (MH20-GRP), the C-terminally amidified GRP, was on the C-terminal side of MH20. The GRP-MH20 peptide, but not MH20-GRP, was capable of enhancing luciferase gene delivery to Ad-susceptible cells in a GRP receptor-dependent manner. More importantly, GRP-MH20 could also confer susceptibility to Ad infection to normal or cancer cells that lack fiber receptors for the virus. Our data suggested that GRP receptors could function efficiently as alternative attachment receptors for Ad5, but that Ad5 bound to GRP receptors still depended, at least partially, on the penton base-mediated endocytotic pathway for subsequent cell entry. Gene delivery by a human adenovirus serotype 5 (Ad5) vector was assayed with a bimodular oligopeptide carrying two peptide domains of different binding specificities. One domain was a high-affinity peptide ligand of the Ad5 fiber knob (MH20), and the other corresponded to the gastrin-releasing peptide (GRP). The synthetic peptide GRP-MH20 was found to be capable of enhancing Ad-mediated gene transfer to Ad-susceptible cells in a GRP receptor-dependent manner. More importantly, GRP-MH20 could also confer susceptibility to Ad infection to normal or cancer cells that lack fiber receptors. Our data suggested that GRP receptors could function efficiently as alternative attachment receptors for Ad5, but virus bound to GRP receptors still depended partially on the penton base-mediated pathway for cell entry.

Cellular uptake and nuclear delivery of recombinant adenovirus penton base

An Ad2 capsid component, the penton base, expressed as recombinant protein, was found to be capable of affecting the entire entry pathway of adenovirion in HeLa cells, i.e., cell attachment, endocytosis, vesicular escape, intracytoplasmic movement, and translocation through the nuclear pore complex. Data with pentamerization-defective mutants suggested that none of these successive steps depended upon penton base pentamer status, indicating that the peptide domains responsible for these functions were carried by the monomer. Observations performed with wild-type (WT) and an integrin-binding-site double-mutant (K288E340) suggested that the penton base could enter the cell via an alternative, RGD- and LDV-independent, pathway. Of three mutants that were found to be defective in nuclear addressing in insect cells, only one, W165H, was also altered in nuclear transport in HeLa cells. The other two, W119H and RRR547EQQ, showed a WT pattern of nuclear localization in HeLa cells, suggesting that the region including tryptophan-119 and the basic signal at position 547 did not act as a nuclear localization signal in the human cell context. The integrity of cellular structures and the cytoskeleton seemed to be required for the vectorial movement and nuclear import of WT penton base, as suggested by experiments using permeabilized HeLa cells, isolated nuclear membranes, and cytoskeleton-targeted drugs.

Allelic frequencies of six (CA)n microsatellite markers of the dystrophin gene in the Korean population

Using the polymerase chain reaction, we examined the allele frequencies and heterozygosities of six (CA)n markers of the dystrophin gene in Koreans. Allele frequencies of these markers were different from those reported for Caucasians. The heterozygosity values for these markers range from 29 to 86%. With the exception of the STR50 marker, these values were lower than those of Caucasians. However, all markers except for the 3'CA marker showed PIC values over 0.5, suggesting a high degree of polymorphism. Therefore, this study will be useful in linkage analysis for Duchenne and Becker muscular dystrophy families in the Korean population.

Molecular determinants of adenovirus serotype 5 fibre binding to its cellular receptor CAR

Adenovirus (Ad) tropism is mediated in part through the fibre protein. The common coxsackie B virus and Ad receptor (CAR) was recently identified as the major receptor for subgroup C Ad serotype 5 (Ad5) and serotype 2 (Ad2) fibres. Effects of mutations in the Ad5 fibre gene were studied to assess domains of the fibre capsomer that could alter virus tropism without altering virus assembly and replication. All mutants that accumulated as fibre monomers failed to assemble with a penton base and proved lethal for Ad5 which suggests that the absence of infectious virions resulted in part from a defect in fibre penton base assembly. Cell binding capacity of all fibre mutants was investigated in cell binding competition experiments with adenovirions using CHO-CAR cells (CHO cells that have been transfected with CAR cDNA and express functional CAR). The results suggest that the R-sheet of the Ad5 fibre knob monomer contains binding motifs for CAR and that beta-strands E and F, or a region close to them, may also be involved in receptor recognition.

Polymorphisms in the human autosomal dominant polycystic kidney disease 2 (PKD2) gene

Three polymorphisms of the PKD2 (MIM 173910) gene in patients with autosomal dominant polycystic kidney disease are reported: (1) a substitution from ATT (isoleucine) to GTT (valine) at codon 452; (2) a substitution from CGG (arginine) to CAG (glutamine) at codon 848; and (3) a substitution from G to A in intron 4 of the gene. The minor allelic frequencies of codon 452 and intron 4 in the Korean population were estimated to be 0.03 and 0.32, respectively. Although the codon 848 substitution was not observed in 45 unrelated healthy Korean people, the substitution did not cosegregate with the disease phenotype, suggesting that this was a rare, non-deleterious alteration.

HEED, the product of the human homolog of the murine eed gene, binds to the matrix protein of HIV-1

heed, the human homolog of mouse eed and Drosophila esc, two members of the trithorax (trx) and Polycomb group (Pc-G) of genes, was isolated by screening an activated lymphocyte cDNA library versus the immunodeficiency virus type 1 (HIV-1) MA protein used as a bait in a two-hybrid system in yeast. The human EED protein (HEED) had 99. 5% identity with the mouse EED protein and contained seven WD repeats. Two heed gene transcripts were identified, with a putative 407-nucleotide-long intron, giving rise to two HEED protein isoforms of 535 and 494 residues in length, respectively. The shorter HEED isoform, originated from the unspliced message, lacked the seventh WD repeat. HEED was found to bind to MA protein in vitro, as efficiently as in vivo in yeast cells. Site-directed mutagenesis and phage biopanning suggested that the interaction between HEED and MA involved the N-terminal region of the MA protein, including the first polybasic signal, in a MA conformation-dependent manner. In the HEED protein, however, two discrete linear MA-binding motifs were identified within residues 388-403, overlapping the origin of the fifth WD repeat. Deletion of the C-terminal 41 residues of HEED, spanning the seventh WD repeat, as in the 494-residue HEED protein, was detrimental to HEED-MA interaction in vivo, suggesting the existence of another C-terminal binding site and/or a conformational role of the HEED C-terminal domain in the MA-HEED interaction. MA and HEED proteins co-localized within the nucleus of co-transfected human cells and of recombinant baculovirus co-infected insect cells. This and the failure of HEED to bind to uncleaved GAG precursor suggested a role of HEED at the early stages of virus infection, rather than late in the virus life cycle.

Synthesis and in vitro cytotoxicity of 3- or 4-dialkylaminomethyl-1-azaanthraquinones

Six 3-dialkylaminomethyl-1-azaanthraquinones and five 4-dialkylaminomethyl-1-azaanthraquinones were synthesized and evaluated in vitro cytotoxicity against four human cancer cell lines. The compounds retained much of their cytotoxic activity against the multi-drug-resistant cell line (KB-V-1) as shown by resistance index.

Correction for non-ideal tracer pharmacokinetic disposition by disposition decomposition analysis (DDA)

PURPOSE

Pharmacokinetic (PK) studies assume that the tracer's PK is equivalent to the parent compound. This assumption is often violated. The aim of this work is to present a method enabling the ideal tracer PK, i.e. the PK of the parent compound, to be predicted from the non-ideal tracer.

METHODS

The procedure uses a disposition decomposition-recomposition (DDR) that assumes that the labeling mainly changes the elimination kinetics while the distribution kinetics is not significantly affected. In the DDR procedure an elimination rate constant correction factor (kCOR) is determined from a simultaneously fitting to plasma concentration data resulting from an i.v. injection of both the tracer and the parent compound. The correction factor is subsequently used to predict the ideal tracer PK behavior from the disposition function (i.v. bolus response) of the non ideal tracer.

RESULTS

The DDR method when applied to plasma level data of erythropoietin (r-HuEPO) and its iodinated tracer (125I-r-HuEPO) from a high (4000U/kg) and a low (400U/kg) dosing of r-HuEPO in newborn lambs (n=13) resulted in excellent agreements in the elimination rate corrected dispositions in all cases (r=0.995, SD=0.0095). The correction factor did not show a dose dependence (p > 0.05). The correction factors were all larger than 1 (kCOR=1.94, SD=0.519) consistent with a reduction in the EPO elimination by the iodination labeling.

CONCLUSIONS

The DDR tracer correction methodology produces a better differentiation of the PK of endogenously produced compounds by correcting for the non-ideal PK behavior of chemically produced tracers.

High-level expression of the angiotensin-converting-enzyme-inhibiting peptide, YG-1, as tandem multimers in Escherichia coli

To produce a large quantity of the angiotensin-converting- enzyme(ACE)-inhibiting peptide YG-1, which consists of ten amino acids derived from yeast glyceraldehyde-3-phosphate dehydrogenase, a high-level expression was explored with tandem multimers of the YG-1 gene in Escherichia coli. The genes encoding YG-1 were tandemly multimerized to 9-mers, 18-mers and 27-mers, in which each of the repeating units in the tandem multimers was connected to the neighboring genes by a DNA linker encoding Pro-Gly-Arg for the cleavage of multimers by clostripain. The multimers were cloned into the expression vector pET-21b, and expressed in E. coli BL21(DE3) with isopropyl beta-D-thiogalactopyranoside induction. The expressed multimeric peptides encoded by the 9-mer, 18-mer and 27-mer accumulated intracellularly as inclusion bodies and comprised about 67%, 25% and 15% of the total proteins in E. coli respectively. The multimeric peptides expressed as inclusion bodies were cleaved with clostripain, and active monomers were purified to homogeneity by reversed-phase high-performance liquid chromatography. In total, 105 mg pure recombinant YG-1 was obtained from 11 E. coli culture harboring pETYG9 which contained the 9-mer of the YG-1 gene. The recombinant YG-1 was identical to the natural YG-1 in molecular mass, amino acid sequence and ACE-inhibiting activity.

Interaction and co-encapsidation of human immunodeficiency virus type 1 Gag and Vif recombinant proteins

Human immunodeficiency virus type 1 (HIV-1) wild-type (WT) virion infectivity factor (Vif) protein (Vifwt) and full-length Gag precursor (Pr55Gag) were found to be co-encapsidated into extracellular, membrane-enveloped virus-like particles released by budding from Sf9 cells co-expressing the two recombinant proteins in trans, with an average copy number of 3.5+/-0.6 Vifwt per 100 Pr55Gag molecules. No preferential localization at the plasma membrane was observed for recombinant Vif in the absence of Gag expression, and a significant proportion of Vif accumulated within the nucleus. Two conserved motifs, W89RKRRY94 and P156KKIKP161, seemed to act as nuclear addressing signals. The Pr55Gag and Vifwt interacting domains were analysed by biopanning of a phage-displayed hexapeptide library. The Vif-binding domain, which spanned residues H421-T470 in Pr55Gag, corresponded to the C-terminal region of nucleocapsid (NC), including the second zinc finger, the intermediate spacer peptide sp2 and the N-terminal half of the p6 domain. Deletions in these Gag domains significantly decreased the Vif encapsidation efficiency, and complete deletion of NC abolished Vif encapsidation. In Vif, four discrete Gag-binding sites were identified, within residues T68-L81 (site I) and W89-P100 (site II) in the central domain, and within residues P162-R173 (III) and P177-M189 (IV) at the C terminus. Substitutions in site I and deletion of site IV were detrimental to Vif encapsidation, whereas substitution of basic residues for alanine in sites III and IV had a positive effect. The data suggest a direct intracellular Gag-Vif interaction and the occurrence of a Pr55Gag-mediated membrane-targeting pathway for Vif in Sf9 cells.

Accelerated oral absorption of gliclazide in human subjects from a soft gelatin capsule containing a PEG 400 suspension of gliclazide

Whether a rapid elevation of serum gliclazide concentration in human subjects can be achieved through an acceleration of dissolution of gliclazide from a formulation was examined. A soft gelatin capsule containing PEG 400, PEG 4000, Tween 20 and glycerin was prepared as a formulation that may accelerate dissolution of gliclazide. The in vitro dissolution of gliclazide at pH 7.2 was identical for the soft capsule and conventional tablets, Diamicron and Diberin. However, at pH 1, 2 and 4.0 the dissolution from the soft capsule was more rapid compared to the tablets. When bioavailability parameters were compared following oral administration of the soft capsule and Diamicron to 16 healthy Korean male subjects, the parameters representing the amount of adsorption (i.e. the area under the serum gliclazide concentration vs. time curve up to 24 h, AUC24, and the peak serum concentration Cmax) were not statistically different for both formulations. However, the time required to reach the peak (Tmax) was significantly shorter for the soft capsule than for the Diamicron. Our results, therefore, indicate that a rapid elevation of serum gliclazide concentration following oral administration of a formulation can be achieved by accelerating the in vitro dissolution of gliclazide from the formulation into the acidic buffers. Thus, the rate of gastrointestinal absorption of gliclazide appears to be dependent on its in vivo dissolution rate in gastric fluid. A soft capsule containing a PEG 400 suspension of gliclazide appears to be an appropriate formulation for accelerating the dissolution.

Structural and functional determinants in adenovirus type 2 penton base recombinant protein

Discrete domains involved in structural and functional properties of adenovirus type 2 (Ad2) penton base were investigated with site-directed mutagenesis of the recombinant protein expressed in baculovirus-infected cells. Seventeen substitution mutants were generated and phenotyped for various functions in insect and human cells as follows. (i) Pentamerization of the penton base protein was found to be dependent on three amino acid side chains, the indole ring of Trp119, the hydroxylic group of Tyr553, and the basic group of Lys556. (ii) Arg254, Cys432, and Trp439, the stretch of basic residues at positions 547 to 556, and Arg340 of the RGD motif played a critical role in stable fiber-penton base interactions in vivo. (iii) Nuclear localization of penton base in Sf9 cells was negatively affected in mutants W119H or W165H, and, to a lesser extent, by substitutions in the consensus polybasic signal at positions 547 to 549. (iv) Penton base mutants were also assayed for HeLa cell binding, cell detachment, plasmid DNA internalization, and Ad-mediated gene delivery. The results obtained suggested that the previously identified integrin-binding motifs RGD340 and LDV287 were functionally and/or topologically related to other discrete regions which include Trp119, Trp165, Cys246, Cys432, and Trp439, all of which were involved in penton base-cell surface recognition, endocytosis, and postendocytotic steps of the virus life cycle.

Adenovirus type 5 fiber knob binds to MHC class I alpha2 domain at the surface of human epithelial and B lymphoblastoid cells

Adenovirus serotype 5 (Ad5) fiber receptor was investigated using reverse antibody biopanning of a phage-displayed hexapeptide library, and virus-neutralizing monoclonal antibodies (mAbs 1D6.3 and 7A2.7) raised against recombinant Ad5 fiber knob. Both mAbs inhibited attachment of Ad5 to HeLa cells. Mimotopes of 1D6.3 showed homology with the C-terminal segment of the alpha2 domain of the heavy chain of human MHC class I molecules (MHC-I alpha2), and mimotopes of 7A2.7 were consensus to human fibronectin type III (FNIII) modules. In vitro, GST-fused MHC-I alpha2- and FNIII-derived oligopeptides interacted with recombinant fibers in a subgroup-specific manner. In vivo, the MHC-I alpha2 synthetic icosapeptide RAIVGFRVQWLRRYFVNGSR showed a net neutralization effect on Ad5 in HeLa cells, whereas the FNIII icosapeptide RHILWTPANTPAMGYLARVS significantly increased Ad5 binding to HeLa cells. Daudi cells, which lack surface expression of HLA class I molecules, showed a weak capacity for Ad5 binding. In beta2-microglobulin-transfected Daudi cells, Ad5 attachment and permissivity were restored to HeLa cell levels, with 4000 receptors per cell and a binding constant of 1.4x10(10)/M. The results suggested that the conserved region of MHC-I alpha2-domain including Trp167 represents a high affinity receptor for Ad5 fiber knob, whereas ubiquitous FNIII modules would serve as auxiliary receptors.