Ninety-day toxicity and genotoxic effects of synthetically derived fully saturated forms of anacardic acid in mice

Organically synthesized fully saturated form of Anacardic acid (AA) has previously shown to be effective in the treatment of inflammatory autoimmune disease. In this study, organically synthesized fully saturated form of AA was orally administered to male and female Swiss albino mice for 90 consecutive days at doses of 25, 50 and 100 mg/kg BW (n = 20 per sex/group). Administration of AA was well tolerated at all dose levels. The treated animals did not show a dose-response toxicity in their hematology, liver, or metabolic profile. Minimally significant changes in serum biochemistry and hematology parameters were noted, but these were not considered to be of biological or toxicological importance and were not outside the known accepted ranges. Sporadic differences in organ weights were observed between groups, but all were minimal (<10%) and unlikely to indicate toxicity. The incidence of histopathological lesions was comparable between treated and control groups across all tested organs. Based upon these findings, the no-observed-adverse-effect level was determined to be ≥ 100 mg/kg BW, which was the highest dose tested. There were no genotoxic (mutagenic and clastogenic) effects seen in In-vivo micronucleus test, In-vitro chromosomal aberration test and Bacterial reverse mutation test. These results support, no genotoxicity and no toxicity associated with oral consumption of AA in mice as a dietary supplement for beverages and food.

50 A Closed-Loop Clinical Audit on Surgical Documentation at a Tertiary Level Hospital in India: Where Do We Stand?

Aim

To perform an audit to check Quality & Compliance of Surgical documentation using STAR Score at a tertiary hospital in India.

Method

A total of 90 case files were studied and assessed in detail from all surgical departments. The audit was done for a period of 1 month at a tertiary hospital in India. The “STAR: Surgical tool for auditing records” tool was used to collect data accordingly. The results were then compared with standard guidelines and analyzed. A series of departmental training and implementation meetings were carried out. After 2 weeks, a re-audit was performed.

Result

The overall compliance score of the hospital was found to be 74%. Departments of General surgery and orthopedics showed a higher rate of compliance, each constituting 82% while the Department of Neurosurgery showed the least compliance of 62%. It was also seen that the maximum percentage of missing information consisted of anesthetic records and subsequent entries. After the re-audit, a considerable improvement was observed, with the compliance rate improving to 90% in all departments.

Conclusion

We believe that compliance and implementation of the STAR Score is mandatory, as it can significantly improve the quality of documentation and can be implemented universally.

Which long line do we use in very low birth weight neonates; umbilical venous catheter or peripherally inserted central catheter?

BACKGROUND

Umbilical venous catheters (UVC) and peripherally inserted central catheters (PICC) are commonly used in preterms. UVC is cheap, easy to insert but has shorter dwell time. UVC is replaced after 7 days due to the risk of complications. This is associated with increased cost, work, and risk of nosocomial infections. The aim of this study was to determine the antenatal and postnatal factors that predict the need for a central line for more than 7 days, thus helping select between UVC or PICC on day 1 of life in babies ≤1500 grams.

METHODS

We retrospectively collected antenatal and postnatal data of VLBW neonates over a period of 1 year who needed CL during their NICU stay. We then divided them into two cohorts. Group 1: CL ≤7 days. Group 2: CL > 7 days.

RESULTS

Sepsis and catheter complications were lower with use of a single CL or duration being ≤7 days. Birth weight, incomplete/no antenatal steroids, need for resuscitation, low Apgar's, RDS, hs-PDA, and initiation of feeds beyond 24 hours of birth were significant. The score was devised based on factors found significant that had an acceptable AUC of 0.767 on ROC analysis with a score of 1 or above having 74.8% sensitivity and 67.7% specificity for prediction of need for CL > 7 days.

CONCLUSIONS

Birth weight ≤1000 grams, incomplete steroids and need for resuscitation at birth were predictive of the need of CL beyond seven days, on day one of life.

Assessment of occupational hazards among dentists practicing in Mumbai

Aim:

To assess the awareness of various occupational hazards experienced and the preventive measures undertaken by the dentists in and around Mumbai.

Methods:

The present study was conducted using self-administered questionnaire, which was circulated to 200 dentists practicing in and around Mumbai. The questionnaire also included questions on personal information like age, gender, position (student or faculty), years of experience, and number of working hours per day. Those who completed the questionnaire form completely and willing to participate were only included in the study. The results were analyzed using SPSS version 22.0.

Results:

23.5% of the participants had the dental working experience more than 10 years and 28.5% dentists worked for ≥8 h. 69% were general practitioners and 40% of the participants treat nearly 10 to 20 patients per day. 45% of them experienced needle stick injury in clinical practice. 1.5% of dentists in our study admitted receiving some litigation from their patients.

Conclusion:

The present study indicated that occupational hazards, awareness about biological hazards, and preventive measures observed by dentists in Mumbai are generally consistent with published guidelines for infection control and also in accordance with the previous research. The majority of the dental practitioners were suffering from pain in the muscles of neck or back. Regular training and workshops can help lower such problems.

Anthropometric measures as biomarkers of neurodevelopmental outcomes of newborns with moderate to severe hypoxic ischemic encephalopathy

BACKGROUND

Perinatal asphyxia is a prominent cause of neonatal mortality in the developing world. Growth in head circumference is associated with improved neurodevelopment. Previous studies found a positive correlation between additional dietary supplementation and growth in head circumference among newborns with perinatal brain injury. This study aims to evaluate the association between anthropometric parameters and developmental outcomes in newborns with hypoxic ischemic encephalopathy (HIE).

METHODS

Newborns at ≥36 weeks gestation with moderate to severe HIE were included in the study and growth parameters were monitored. Newborns with life-threatening anomalies were excluded. None of the study participants received therapeutic hypothermia (TH). Developmental Assessment Scale for Indian Infants (DASII) was used to evaluate neurodevelopmental outcomes at 1 year of age.

RESULTS

Of 76 study participants, 46 were followed for 12 months, 28 died, and 2 were lost to follow-up. HIE stage III, Apgar score <5 at 5 minutes of age, pH ≤ 7.1 on first blood gas and base deficit > - 16 was associated with death or disability at 1 year of age. All anthropometric parameters were significantly lower in presence of death or disability. pH ≤ 7.1 at birth (odds ratio: 11.835, 95% CI 2.273-61.629, p = 0.003) and weight gain at one year (odds ratio 1.001, 95% CI 1.000-1.002, p = 0.03) were significantly associated with death and disability.

CONCLUSION

pH > 7.1 at birth, and weight gain were associated with better neurodevelopmental outcomes at 1 year of age. Thus, in addition to TH, nutritional interventions may potentially improve outcomes among newborns with HIE.

The CFTR gene mild variants poly-T, TG repeats and M470V detection in Indian men with congenital bilateral absence of vas deferens

The aim of the study was to detect the frequency of the CFTR gene variants poly-T, TG repeats and c.1408A>G p.Met470Val (M470V) in Indian men with congenital bilateral absence of the vas deferens (CBAVD). Men diagnosed with CBAVD (n = 76), their female partners (n = 76) and healthy men from general population (n = 50) were recruited. Genomic DNA was isolated and the polymorphic regions of IVS9- c.1210-12T [5] and M470V were amplified using specific primers followed by Sanger's DNA sequencing. A statistically significant increase in the frequency of heterozygous IVS9- c.1210-12T [5] (39.4%) was observed in CBAVD men as compared to controls (14%). The allelic distribution of c.1210-12T [5], c.1210-12T [7] and c.1210-12T [9] in CBAVD men was 21%, 64.4% and 13% and that in healthy controls was 7%, 73% and 20% respectively. Longest TG repeat c.1210-34TG [13] was found in association with c.1210-12T [5] with an allelic frequency of 5.9% in CBAVD men. We found a significant association of c.1210-34TG [12]/c.1210-34TG [13] - c.1210-12[5] -V470 allele in CBAVD men. Twelve female partners harboured a heterozygous c.1210-12T [5] allele. The study emphasises the need to screen both partners for the polymorphisms M470V, poly-T, TG tract repeats in addition to population-specific known CFTR gene mutations.

Genetic architecture of cyst nematode resistance revealed by genome-wide association study in soybean

BACKGROUND

Bi-parental mapping populations have been commonly utilized to identify and characterize quantitative trait loci (QTL) controlling resistance to soybean cyst nematode (SCN, Heterodera glycines Ichinohe). Although this approach successfully mapped a large number of SCN resistance QTL, it captures only limited allelic diversity that exists in parental lines, and it also has limitations for genomic resolution. In this study, a genome-wide association study (GWAS) was performed using a diverse set of 553 soybean plant introductions (PIs) belonging to maturity groups from III to V to detect QTL/genes associated with SCN resistance to HG Type 0.

RESULTS

Over 45,000 single nucleotide polymorphism (SNP) markers generated by the SoySNP50K iSelect BeadChip (http// www.soybase.org ) were utilized for analysis. GWAS identified 14 loci distributed over different chromosomes comprising 60 SNPs significantly associated with SCN resistance. Results also confirmed six QTL that were previously mapped using bi-parental populations, including the rhg1 and Rhg4 loci. GWAS identified eight novel QTL, including QTL on chromosome 10, which we have previously mapped by using a bi-parental population. In addition to the known loci for four simple traits, such as seed coat color, flower color, pubescence color, and stem growth habit, two traits, like lodging and pod shattering, having moderately complex inheritance have been confirmed with great precision by GWAS.

CONCLUSIONS

The study showed that GWAS can be employed as an effective strategy for identifying complex traits in soybean and for narrowing GWAS-defined genomic regions, which facilitates positional cloning of the causal gene(s).

Enhanced hydrogen production under a visible light source and dye degradation under natural sunlight using nanostructured doped zinc orthotitanates

Nanostructured zinc orthotitanates were successfully employed as solar light driven photocatalysts for waste degradation such as H₂S which produces H₂, a clean energy source, and dye degradation.

Safety and pharmacokinetics of the antisense oligonucleotide (ASO) LY2181308 as a single-agent or in combination with idarubicin and cytarabine in patients with refractory or relapsed acute myeloid leukemia (AML)

Survivin is expressed in tumor cells, including acute myeloid leukemia (AML), regulates mitosis, and prevents tumor cell death. The antisense oligonucleotide sodium LY2181308 (LY2181308) inhibits survivin expression and may cause cell cycle arrest and restore apoptosis in AML. In this study, the safety, pharmacokinetics, and pharmacodynamics/efficacy of LY2181308 was examined in AML patients, first in a cohort with monotherapy (n = 8) and then post-amendment in a cohort with the combination of cytarabine and idarubicin treatment (n = 16). LY2181308 was administered with a loading dosage of three consecutive daily infusions of 750 mg followed by weekly intravenous (IV) maintenance doses of 750 mg. Cytarabine 1.5 g/m(2) was administered as a 4-hour IV infusion on Days 3, 4, and 5 of Cycle 1, and idarubicin 12 mg/m(2) was administered as a 30-minute IV infusion on Days 3, 4, and 5 of Cycle 1. Cytarabine and idarubicin were administered on Days 1, 2, and 3 of each subsequent 28-day cycle. Reduction of survivin was evaluated in peripheral blasts and bone marrow. Single-agent LY2181308 was well tolerated and survivin was reduced only in patients with a high survivin expression. In combination with chemotherapy, 4/16 patients had complete responses, 1/16 patients had incomplete responses, and 4/16 patients had cytoreduction. Nine patients died on study: 6 (monotherapy), 3 (combination). LY2181308 alone is well tolerated in patients with AML. In combination with cytarabine and idarubicin, LY2181308 does not appear to cause additional toxicity, and has shown some clinical benefit needing confirmation in future clinical trials.

Development of Buccal Adhesive Tablet with Prolonged Antifungal activity: Optimization and ex vivo Deposition Studies

The purpose of the present work was to prepare buccal adhesive tablets of miconazole nitrate. The simplex centroid experimental design was used to arrive at optimum ratio of carbopol 934P, hydroxypropylmethylcellulose K4M and polyvinylpyrollidone, which will provide desired drug release and mucoadhesion. Swelling index, mucoadhesive strength and in vitro drug release of the prepared tablet was determined. The drug release and bioadhesion was dependent on type and relative amounts of the polymers. The optimized combination was subjected to in vitro antifungal activity, transmucosal permeation, drug deposition in mucosa, residence time and bioadhesion studies. IR spectroscopy was used to investigate any interaction between drug and excipients. Dissolution of miconazole from tablets was sustained for 6 h. based on the results obtained, it can be concluded that the prepared slow release buccoadhesive tablets of miconazole would markedly prolong the duration of antifungal activity. Comparison of in vitro antifungal activity of tablet with marketed gel showed that drug concentrations above the minimum inhibitory concentration were achieved immediately from both formulations but release from tablet was sustained up to 6 h, while the gel showed initially fast drug release, which did not sustain later. Drug permeation across buccal mucosa was minimum from the tablet as well as marketed gel; the deposition of drug in mucosa was higher in case of tablet. In vitro residence time and bioadhesive strength of tablet was higher than gel. Thus the buccoadhesive tablet of miconazole nitrate may offer better control of antifungal activity as compared to the gel formulation.

Tumor survivin is downregulated by the antisense oligonucleotide LY2181308: a proof-of-concept, first-in-human dose study

PURPOSE

Enhanced tumor cell survival through expression of inhibitors of apoptosis (IAP) is a hallmark of cancer. Survivin, an IAP absent from most normal tissues, is overexpressed in many malignancies and associated with a poorer prognosis. We report the first-in-human dose study of LY2181308, a second-generation antisense oligonucleotide (ASO) directed against survivin mRNA.

PATIENTS AND METHODS

A dose-escalation study evaluating the safety, pharmacokinetics, and pharmacodynamics of LY2181308 administered intravenously for 3 hours as a loading dose on 3 consecutive days and followed by weekly maintenance doses. Patients were eligible after signing informed consent, had exhausted approved anticancer therapies and agreed to undergo pre- and posttreatment tumor biopsies to evaluate reduction of survivin protein and gene expression.

RESULTS

A total of 40 patients were treated with LY2181308 at doses of 100 to 1,000 mg. Twenty-six patients were evaluated at the recommended phase 2 dose of 750 mg, at which level serial tumor sampling and [(11)C]LY2183108 PET (positron emission tomography) imaging demonstrated that ASO accumulated within tumor tissue, reduced survivin gene and protein expression by 20% and restored apoptotic signaling in tumor cells in vivo. Pharmacokinetics were consistent with preclinical modeling, exhibiting rapid tissue distribution, and terminal half-life of 31 days.

CONCLUSIONS

The tumor-specific, molecularly targeted effects demonstrated by this ASO in man underpin confirmatory studies evaluating its therapeutic efficacy in cancer.

Routine antibiotic use in preterm neonates: a randomised controlled trial

The immature immune system of preterm neonates puts them at higher risk of neonatal sepsis. We conducted a part-blinded randomised controlled trial to compare the effect of routine antibiotic treatment on the incidence of clinical sepsis in preterm neonates. Preterm neonates without other risk factors for infection admitted in the first 12h of life were randomised to receive routine antibiotics or to a control group (no antibiotics unless clinically indicated). The primary outcome variable was the incidence of clinical sepsis. Secondary outcomes were the incidence of positive blood cultures, necrotising enterocolitis (NEC) stage II or III, or death, and the duration of hospital stay. The incidence of clinical sepsis was comparable in both groups (intervention 31.9%, control 25.4%; P=0.392). Mortality was equivalent in both groups. The control group had significantly more positive blood cultures (P=0.002). The incidence of NEC and the duration of hospital stay were comparable in both groups. In low risk preterm neonates we found no evidence that routine antibiotic use has a protective effect.

Pharmacodynamic (PD) evaluation of LY2181308 in patients with metastatic malignancies

3507

Background: Survivin is an inhibitor of apoptosis and its overexpression in cancer has been associated with poor survival. LY2181308 (LY), a novel modified antisense oligonucleotide is a specific inhibitor of survivin. The safety and PK profile of LY from this first-in-human study was presented at ASCO 2008. We now present the PD data from this trial. Methods: Patients with advanced or metastatic malignancies who had failed previous anti-tumor treatments were enrolled. Three consecutive IV loading doses given over 3 hours were followed by weekly maintenance doses. Pre- and post-dosing biopsies were mandated to test for evidence of modification of the target at doses where a PD effect was expected. Biopsies were taken 48 hours after the last loading dose by CT-guided fine needle biopsy. Tumor tissue was paraffin-embedded for immunohistochemistry (IHC) and survivin gene expression. Given the finite amount of biopsy material, the quantification of survivin protein was prioritized. In addition, at one site, pre- and post-dosing endobronchial sampling was conducted in NSCLC patients, with the aim of quantifying levels of native survivin protein, and assessing changes in cell cycle profile in freshly isolated tumor cells using FACS analysis. Results: Out of the 34 patients enrolled, 22 patients had a pre- and posttreatment biopsy. Results from IHC indicated that survivin expression was reduced in the nucleus and cytoplasm in 11/17 and 5/14 evaluable pairs, respectively. LY was detected in neoplastic and non-neoplastic tumor cells in 5/16 and 15/16 evaluable pairs respectively. Gene expression analysis indicated a reduction in survivin expression by 20% to 50% in 11/15 evaluable pairs. Analysis of the fresh tumor material from endobronchial sampling revealed that 2 out of 3 patients with NSCLC had a near-complete elimination of survivin-positive cells accompanied by an increase in the fraction of cells with a sub-G1 DNA content, consistent with cell death. Conclusions: In this study, we were able to demonstrate the presence of the ASO in tumor tissue and confirm a reduction in survivin protein and gene expression. These findings demonstrate the proof of principle of antitumor activity of LY and provide the rationale for phase II studies.

[Table: see text]

Maternal blood aspiration: an unusual cause of respiratory distress in a neonate

Maternal blood aspiration is an unusual cause of respiratory distress in neonates. It is occasionally seen in babies born to mothers with antepartum haemorrhage (APH). We report a term neonate with a history of maternal APH who developed respiratory distress soon after birth with a radiological appearance compatible with aspiration syndrome. The infant required ventilation for 36 hours. The aspirated blood was the mother's.

An innovative design for simultaneous reconstruction of complex maxillo-mandibular defects with single free fibula osteocutaneous flap

Satisfactory reconstruction of complex maxillo-mandibular defect in a single stage has been a surgical challenge. This is particularly because it necessitates a flap which will reconstruct both the maxilla and mandible along with any associated soft tissue defect, mucosa or skin without adding to functional and cosmetic problems for patient and technical problems for the surgeon. Here we describe an innovative design for simultaneous reconstruction of maxilla, mandible, soft tissue and mucosal lining in one stage using a single fibula osteocutaneous flap.

Gastric aspirate shake test for diagnosis of surfactant deficiency in neonates with respiratory distress

The gastric aspirate shake test (GST) was evaluated in 77 newborns with respiratory distress for predicting hyaline membrane disease (HMD) at KEM Hospital, Pune, India.

METHODS

Over 0.5 ml of gastric fluid was obtained within 30 min of birth and mixed with an equal volume of normal saline for 10 sec; 1 ml of 95% ethanol was then added and the mixture agitated for 10 sec. After standing for 15 min, the air-liquid interface was examined for bubbles.

RESULTS

All 21 infants with a negative GST developed HMD. However, 12 infants with an intermediate and nine with a positive test also developed HMD. None of the infants with other respiratory disorders, e.g. transient tachypnoea and pneumonia, had a negative GST. A negative GST had a specificity of 100%, sensitivity of 70% and positive predictive value of 100% for developing HMD.

CONCLUSION

GST is a useful test for predicting HMD and might be of particular value in developing countries.

Method Validation and Measurement of Biomarkers in Nonclinical and Clinical Samples in Drug Development: A Conference Report

Biomarkers are increasingly used in drug development to aid scientific and clinical decisions regarding the progress of candidate and marketed therapeutics. Biomarkers can improve the understanding of diseases as well as therapeutic and off-target effects of drugs. Early implementation of biomarker strategies thus promises to reduce costs and time-to-market as drugs proceed through increasingly costly and complex clinical development programs. The 2003 American Association of Pharmaceutical Sciences/Clinical Ligand Assay Society Biomarkers Workshop (Salt Lake City, UT, USA, October 24-25, 2003) addressed key issues in biomarker research, with an emphasis on the validation and implementation of biochemical biomarker assays, covering from preclinical discovery of efficacy and toxicity biomarkers through clinical and postmarketing implementation. This summary report of the workshop focuses on the major issues discussed during presentations and open forums and noted consensus achieved among the participants on topics from nomenclature to best practices. For example, it was agreed that because reliable and accurate data provide the basis for sound decision making, biomarker assays must be validated in a manner that enables the creation of such data. The nature of biomarker measurements often precludes direct application of regulatory guidelines established for clinical diagnostics or drug bioanalysis, and future guidance on biomarker assay validation should therefore be adaptable enough that validation criteria do not stifle creative biomarker solutions.

Site-specific acetylation by p300 or CREB binding protein regulates erythroid Krüppel-like factor transcriptional activity via its interaction with the SWI-SNF complex

Recruitment of modifiers and remodelers to specific DNA sites within chromatin plays a critical role in controlling gene expression. The study of globin gene regulation provides a convergence point within which to address these issues in the context of tissue-specific and developmentally regulated expression. In this regard, erythroid Krüppel-like factor (EKLF) is critical. EKLF is a red cell-specific activator whose presence is crucial for establishment of the correct chromatin structure and high-level transcriptional induction of adult beta-globin. We now find, by metabolic labeling-immunoprecipitation experiments, that EKLF is acetylated in the erythroid cell. EKLF residues acetylated by CREB binding protein (CBP) in vitro map to Lys-288 in its transactivation domain and Lys-302 in its zinc finger domain. Although site-specific DNA binding by EKLF is unaffected by the acetylation status of either of these lysines, directed mutagenesis of Lys-288 (but not Lys-302) decreases the ability of EKLF to transactivate the beta-globin promoter in vivo and renders it unable to be superactivated by coexpressed p300 or CBP. In addition, the acetyltransferase function of CBP or p300 is required for superactivation of wild-type EKLF. Finally, acetylated EKLF has a higher affinity for the SWI-SNF chromatin remodeling complex and is a more potent transcriptional activator of chromatin-assembled templates in vitro. These results demonstrate that the acetylation status of EKLF is critical for its optimal activity and suggest a mechanism by which EKLF acts as an integrator of remodeling and transcriptional components to alter chromatin structure and induce adult beta-globin expression within the beta-like globin cluster.

Functional selectivity of recombinant mammalian SWI/SNF subunits

The SWI/SNF family of chromatin-remodeling complexes plays a key role in facilitating the binding of specific transcription factors to nucleosomal DNA in diverse organisms from yeast to man. Yet the process by which SWI/SNF and other chromatin-remodeling complexes activate specific subsets of genes is poorly understood. We show that mammalian SWI/SNF regulates transcription from chromatin-assembled genes in a factor-specific manner in vitro. The DNA-binding domains (DBDs) of several zinc finger proteins, including EKLF, interact directly with SWI/SNF to generate DNase I hypersensitivity within the chromatin-assembled beta-globin promoter. Interestingly, we find that two SWI/SNF subunits (BRG1 and BAF155) are necessary and sufficient for targeted chromatin remodeling and transcriptional activation by EKLF in vitro. Remodeling is achieved with only the BRG1-BAF155 minimal complex and the EKLF zinc finger DBD, whereas transcription requires, in addition, an activation domain. In contrast, the BRG1-BAF155 complex does not interact or function with two unrelated transcription factors, TFE3 and NF-kappaB. We conclude that specific domains of certain transcription factors differentially target SWI/SNF complexes to chromatin in a gene-selective manner and that individual SWI/SNF subunits play unique roles in transcription factor-directed nucleosome remodeling.

Enhancing activity and phospholipase A2 activity: two independent activities present in the enhancing factor molecule

Enhancing factor (EF), a molecule that increases the binding of epidermal growth factor (EGF) to A431 cells, was first isolated in our laboratory from mouse intestines, and subsequently shown to be a secretory form of phospholipase A2 (PLA2) [Mulherkar, Rao, Wagle, Patki and Deo (1993) Biochem. Biophys. Res. Commun. 195, 1254-1263]. We had proposed earlier that EF increases the binding of EGF by first binding to its own cell-surface receptor [identified as a 100 kDa molecule; Mulherkar and Deo (1986) J. Cell. Physiol. 127, 183-188], and then by creating a binding site for EGF. However, due to its PLA2 activity, there was a possibility that EF, by its phospholipase activity could be unmasking cryptic EGF receptors on the cell surface, thereby increasing the number of binding sites for EGF. To test whether enhancing activity and phospholipase activity are independent of each other, a series of mutations were created using the full-length EF cDNA as a template, expressed in 293 cells and the mutant recombinant proteins checked for EF as well as PLA2 activities. Our studies have shown that one of the mutant EF proteins, lacking PLA2 activity, retains EF activity. This demonstrates unambiguously that EF and PLA2 activities are two independent activities in the same molecule. Mutation in the Ca2+-binding loop resulted in loss of EF activity, thereby demonstrating that EF activity is Ca2+-dependent. The N-terminal region of the EF molecule appears to be crucial for the enhancing activity.

Both group IB and group IIA secreted phospholipases A2 are natural ligands of the mouse 180-kDa M-type receptor

Snake venom and mammalian secreted phospholipases A2 (sPLA2s) have been associated with toxic (neurotoxicity, myotoxicity, etc.), pathological (inflammation, cancer, etc.), and physiological (proliferation, contraction, secretion, etc.) processes. Specific membrane receptors (M and N types) for sPLA2s have been initially identified with snake venom sPLA2s as ligands, and the M-type 180-kDa receptor was cloned from different animal species. This paper addresses the problem of the endogenous ligands of the M-type receptor. Recombinant group IB and group IIA sPLA2s from human and mouse species have been prepared and analyzed for their binding properties to M-type receptors from different animal species. Both mouse group IB and group IIA sPLA2s are high affinity ligands (in the 1-10 nM range) for the mouse M-type receptor. These two sPLA2s are expressed in the mouse tissues where the M-type receptor is also expressed, making it likely that both types of sPLA2s are physiological ligands of the mouse M-type receptor. This conclusion does not hold for human group IB and IIA sPLA2s and the cloned human M-type receptor. The two mouse sPLA2s have relatively high affinities for the mouse M-type receptor, but they can have much lower affinities for receptors from other animal species, indicating that species specificity exists for sPLA2 binding to M-type receptors. Caution should thus be exerted in avoiding mixing sPLA2s, cells, or tissues from different animal species in studies of the biological roles of mammalian sPLA2s associated with an action through their membrane receptors.

Sequence analysis of full length cDNA for enhancing factor/phospholipase A2

Enhancing factor (EF) protein was initially purified as a modulator of epidermal growth factor from small intestines of mouse. The cDNA sequence, obtained by RT-PCR, revealed that EF belonged to the non-pancreatic, phospholipase A2 (PLA2) family. This was the first report of the mouse PLA2. In the present paper we report the complete cDNA sequence of EF gene, in which the 5' sequence has been obtained by RAcE-PCR. The predicted amino acid sequence was computer analysed and the putative sites for enzyme action, calcium binding and heparin binding have been identified. The complete protein sequence of EF along with 16 aligned sequences were used to infer a phylogenetic tree. From this data the mouse EF was grouped with other membrane associated PLA2 with a bootstrap value of 98% indicating that it belonged to this class.

Novel triterpene sulfates from Fusarium compactum using a rhinovirus 3C protease inhibitor screen

Two novel triterpene sulfates have been isolated from Fusarium compactum by bioactivity-directed fractionation using an assay which measures the inhibition of proteolytic activity of rhinovirus 3C protease on a fluorogenic peptide substrate. The compounds were purified by countercurrent and reverse phase chromatographies. NMR, MS, UV and IR studies revealed two triterpene sulfates, uncommon metabolites of terrestrial fungi.

A method for the selective isolation of Myxococcus directly from soil

A new method is described for the selective isolation of species of Myxococcus directly from soil by dilution plating. The method involves suppression of competing microorganisms with antibiotics combined with air drying and wet heat treatment of soils. Fungi were eliminated by supplementing the plating medium with cycloheximide and nystatin. Non-sporulating bacteria were controlled by air drying soils and then heating aqueous soil dilutions for 10 min at 56 degrees C. The predominant sporulating bacteria in soil, Streptomyces and Bacillus, were suppressed by adding either tiacumicin B, ristocetin or vancomycin to the medium. Swarming of Myxococcus colonies was controlled with a casein digest-yeast extract plating medium (CY-C10 agar). Ultrasound treatment of soil suspensions gave the highest number of Myxococcus colonies in the soils studied, but these cultures could be recovered without ultrasound. Strains of Myxococcus fulvus, M. xanthus, M. coralloides, M. stipitatus and M. virescens were isolated from soil using this technique. Soils examined yielded one or two Myxococcus species per sample.

Dibefurin, a novel fungal metabolite inhibiting calcineurin phosphatase activity

The novel calcineurin inhibitor, dibefurin, has been isolated from the fungal culture AB 1650I-759. The isolation was bioactivity-directed fractionation using an assay which measures the phosphatase activity of calcineurin. The compound was purified by countercurrent, reverse phase and gel filtration chromatographies. Several studies, including crystallographic, NMR and MS, revealed that dibefurin is a novel dimeric compound of a unique structural type.

Antifungal drug targets: Candida secreted aspartyl protease and fungal wall beta-glucan synthesis

The incidence of severe, life-threatening fungal infections has increased dramatically over the last decade. Unfortunately, in practice the arsenal of antifungal drugs is limited to flucytosine, a few approved azoles, and polyenes, mainly amphotericin B. This situation is rather precarious in view of the extended spectrum of fungi causing severe disease in immunocompromised patients, development of resistance to some of the currently used agents, and the minimal fungicidal activity of the azoles. Although lagging behind the need for new antifungal agents, the study of fungal biochemistry, physiology, and genetics has undergone a resurgence to new heights of activity, thus providing a framework on which to build drug discovery programs in several new areas, two of which will be discussed in detail: the biology of Candida albicans secreted aspartyl protease with respect to inhibitor discovery, evaluation, and possible clinical utility; and the fungal cell wall beta-glucans with respect to the mechanism and regulation of synthesis and target sites for drug inhibition.

A high capacity microbial screen for inhibitors of human rhinovirus protease 3C

We have developed a high capacity screen for compounds that inhibit the 3C protease of human rhinovirus-1b. The assay uses a recombinant strain of Escherichia coli expressing both the protease and a tetracycline resistance-conferring protein modified to contain the minimal protease cleavage site. Cultures growing in microtiter plates containing tetracycline are treated with potential inhibitors and simultaneously monitored for change in growth over time using an oxygen probe. Most of the cultures, not containing an inhibitor of the 3C protease, show reduced growth due to cleavage of the essential gene product; normal growth is seen only in the infrequent culture that contains an inhibitor. In the present example, we have used the tetA gene of plasmid pACYC184 as the modified gene. The system has been validated using inhibitors of protease 3C, and has been used to identify three new inhibitors of the enzyme, active in the micromolar range.

Dorrigocins: novel antifungal antibiotics that change the morphology of ras-transformed NIH/3T3 cells to that of normal cells. I. Taxonomy of the producing organism, fermentation and biological activity

The dorrigocins are new secondary metabolites produced by submerged fermentation of a streptomycete which was isolated from a soil sample collected in Australia. The dorrigocins show moderate antifungal activity and reverse the morphology of ras-transformed NIH/3T3 cells from a transformed phenotype to a normal one. The producing culture was identified as Streptomyces platensis subsp. rosaceus strain AB1981F-75.

Dorrigocins: novel antifungal antibiotics that change the morphology of ras-transformed NIH/3T3 cells to that of normal cells. III. Biological properties and mechanism of action

The dorrigocins are unique glutarimide antibiotics which were found to reverse the morphology of ras-transformed NIH/3T3 cells from a transformed phenotype to a normal one. The compounds also inhibited the release of yeast mating pheromone, a-factor. The activity of these compounds was not dependent on inhibition of prenylation or protein synthesis. Dorrigocin A was instead found to inhibit the carboxyl methylation in K-ras transformed cells.

Mechanism-based screens in the discovery of chemotherapeutic antibacterials

Numerous assays have been developed over the last 40 years for the detection of novel antibacterial metabolites. I have discussed many of the successful strategies and suggested some potential targets. Although the trend toward mechanism-based assays is relatively recent, it is clear that they have had a profound impact on screening in drug discovery. Often a mechanism-based assay requires construction of specific strains and verification of the antibacterial role of the selected target. Since the conception and development of a mechanism-based screen depends upon knowledge of the specific target and perhaps a compound that affects that target, it is implicit that mode of action studies on compounds discovered through random screening may subsequently lead to new mechanistic assays. While serendipity continues to play a crucial role in any screen, target-directed assays appear to be a worthwhile approach in antibacterial screening.

5-N-acetylardeemin, a novel heterocyclic compound which reverses multiple drug resistance in tumor cells. I. Taxonomy and fermentation of the producing organism and biological activity

The ardeemins are a new family of secondary metabolites produced by submerged fermentation of a fungus which was isolated from a soil sample collected in Brazil. Based on taxonomic studies, the producing culture was identified as Aspergillus fischeri var. brasiliensis strain AB 1826M-35. 5-N-Acetylardeemin potentiated the cytotoxicity of the anticancer agent vinblastine in multidrug resistant human tumor cells.

Reversal of multidrug resistance by two novel indole derivatives

Two new fused indoles were found to overcome multidrug resistance in P388/Adr cells in vitro. These agents potentiated the cytotoxicity of the antitumor drugs Adriamycin, vinblastine, and vincristine in multidrug-resistant cells with no effect on drug-sensitive parent P388 cells. They significantly increased the ATP-dependent accumulation of [3H]-vinblastine and inhibited efflux of the labeled drug from resistant cells. These compounds also inhibited photoaffinity labeling of P-glycoprotein by [3H]azidopine in P388/Adr cells and membranes isolated from these cells. In addition, the calcium antagonist activity of these compounds was very weak compared with that of verapamil. These data suggest that the compounds reported here may specifically overcome multidrug resistance without the serious hypotensive effects associated with calcium antagonists and that this activity may be independent of their ability to block calcium transport.

High-level expression and purification of mature HIV-1 protease in Escherichia coli under control of the araBAD promoter

A 1.3-kb segment of Escherichia coli DNA containing the regulatory gene, araC, and the promoter of the araBAD operon was amplified by the polymerase chain reaction (PCR) and cloned into pUC18, resulting in plasmid pKB130 that produced the alpha fragment of beta-galactosidase upon addition of L-arabinose (L-ara). A synthetic gene for human immunodeficiency virus (HIV)-1 preprotease was placed downstream of the ara-BAD promoter in pKB130 to create a translational fusion inducible by addition of L-ara. The fusion protein correctly autoprocessed in vivo to yield a mature 99-amino-acid HIV-1 protease, which was found predominantly in inclusion bodies. This material could be refolded to an active form, which was purified to homogeneity. A small fraction of the protease was expressed in vivo as a soluble active form, which allowed the monitoring of expression during fermentation by a rapid and simple whole cell assay employing an HIV-1 protease-specific fluorogenic substrate.