Suspicious Lesion Segmentation on Brain, Mammograms and Breast MR Images Using New Optimized Spatial Feature Based Super-Pixel Fuzzy C-Means Clustering

Suspicious lesion or organ segmentation is a challenging task to be solved in most of the medical image analyses, medical diagnoses and computer diagnosis systems. Nevertheless, various image segmentation methods were proposed in the previous studies with varying success levels. But, the image segmentation problems such as lack of versatility, low robustness, high complexity and low accuracy in up-to-date image segmentation practices still remain unsolved. Fuzzy c-means clustering (FCM) methods are very well suited for segmenting the regions. The noise-free images are effectively segmented using the traditional FCM method. However, the segmentation result generated is highly sensitive to noise due to the negligence of spatial information. To solve this issue, super-pixel-based FCM (SPOFCM) is implemented in this paper, in which the influence of spatially neighbouring and similar super-pixels is incorporated. Also, a crow search algorithm is adopted for optimizing the influential degree; thereby, the segmentation performance is improved. In clinical applications, the SPOFCM feasibility is verified using the multi-spectral MRIs, mammograms and actual single spectrum on performing tumour segmentation tests for SPOFCM. Ultimately, the competitive, renowned segmentation techniques such as k-means, entropy thresholding (ET), FCM, FCM with spatial constraints (FCM_S) and kernel FCM (KFCM) are used to compare the results of proposed SPOFCM. Experimental results on multi-spectral MRIs and actual single-spectrum mammograms indicate that the proposed algorithm can provide a better performance for suspicious lesion or organ segmentation in computer-assisted clinical applications.

An Antifungal Mechanism of Protolichesterinic Acid from the Lichen Usnea albopunctata Lies in the Accumulation of Intracellular ROS and Mitochondria-Mediated Cell Death Due to Apoptosis in Candida tropicalis

Candida species causes superficial and life-threatening systemic infections and are difficult to treat due to the resistance of these organism to various clinically used drugs. Protolichesterinic acid is a well-known lichen compound. Although the antibacterial activity of protolichesterinic acid has been reported earlier, the antifungal property and its mechanism of action are still largely unidentified. The goal of the present investigation is to explore the anticandidal activity and mechanism of action of protolichesterinic acid, especially against Candida tropicalis. The Minimum Inhibitory Concentration (MIC) value was established through microdilution techniques against four Candida species and out of four species tested, C. tropicalis showed a significant effect (MIC: 2 μg/ml). In the morphological interference assay, we observed the enhanced inhibition of hyphae when the cells were treated with protolichesterinic acid. Time-kill assay demonstrated that the maximum rate of killing was recorded between 2 and 6 h. C. tropicalis exposed to protolichesterinic acid exhibited an increased ROS production, which is one of the key factors of fungal death. The rise in ROS was due to the dysfunction of mitochondria caused by protolichesterinic acid. We confirmed that protolichesterinic acid-induced dysfunction of mitochondria in C. tropicalis. The damage of cell membrane due to protolichesterinic acid treatment was confirmed by the influx of propidium iodide and was further confirmed by the release of potassium ions. The treatment of protolichesterinic acid also triggered calcium ion signaling. Moreover, it commenced apoptosis which is clearly evidenced by Annexin V and propidium iodide staining. Interestingly protolichesterinic acid recorded excellent immunomodulatory property when tested against lymphocytes. Finally protolichesterinic acid showed low toxicity toward a normal human cell line Foreskin (FS) normal fibroblast. In in vivo test, protolichesterinic acid significantly enhanced the survival of C. tropicalis infected Caenorhabditis elegans. This investigation proposes that the protolichesterinic acid induces apoptosis in C. tropicalis via the enhanced accumulation of intracellular ROS and mitochondrial damage, which leads fungal cell death via apoptosis. Our work revealed a new key aspect of mechanisms of action of protolichesterinic acid in Candida species. This article is the first study on the antifungal and mechanism of action of protolichesterinic acid in Candida species.

Spectral and chemical characterization of jarosite in a palaeolacustrine depositional environment in Warkalli Formation in Kerala, South India and its implications

Coastal cliffs fringing the Arabian Sea near Varkala exhibits the Warkalli Formation of the Tertiary sequence of Kerala, South India, with well-marked occurrence of jarosite associated with other hydrous mineral phases of phyllosilicate family in a palaeo-lacustrine depositional environment. Sandy phyllosilicates dominate the mineral assemblage, but jarosite occurs as a prominent secondary phase formed during acid-sulphate alteration of iron sulphide in this area. Here, we discuss about the potentiality of spectroscopic techniques to identify the possible mineral phases in the collected samples. The samples from the coastal cliffs have been characterized by hyperspectral analysis (VIS-NIR-SWIR), X-ray Diffraction (XRD), Fourier Transform Infra-red Reflectance (FTIR), Electron Probe Microanalysis (EPMA) and Laser Raman spectroscopy. The spectral and chemical analyses have confirmed the jarosite as natrojarosite and phyllosilicate as kaolinite. Other accessory phases have also been identified through XRD. FTIR spectroscopy has played a major role in identifying the major hydrous bonds between the minerals. VIS-NIR-SWIR spectra show several optimum spectral features at 910nm, 1470nm, 1849-1864nm (in the form of a doublet), 1940nm and 2270nm, which could be utilised to locate jarosite in the remotely-sensed data. X-ray diffraction peaks helped in the identification of maximum number of minerals (kaolinite, smectite, quartz, feldspar, pyrite, marcasite and hematite) and the variation in jarosite content in the samples. We propose the formation of jarosite in the region by a seasonal, local and temporary development of acidic conditions. Abundance of organic matter in a fluvio-lacustrine environment has developed anaerobic conditions by removing available oxygen through decomposition of organic matter containing sulphur compounds. The sulphur thus liberated combines with hydrogen from water to develop acidic conditions and resulted in the formation of jarosite. The occurrence of jarosite in Warkalli Formation suggests on and off supply of water during diagenesis. Jarosite has been detected as a prominent deposit in several regions on Mars by Mars Exploration rover Opportunity and Mars Reconnaissance Orbiter-Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). This study of jarosite formation in terrestrial environment will influence our understanding on the mineral precipitation, diagenesis and hydration processes on Mars. Additionally, it also shows the importance of spectroscopic techniques like Raman spectrometry to be used in future missions to Mars to further validate the results of orbital spectroscopy.

Pseudopyronine B: A Potent Antimicrobial and Anticancer Molecule Isolated from a Pseudomonas mosselii

In continuation of our search for new bioactive compounds from soil microbes, a fluorescent Pseudomonas strain isolated from paddy field soil of Kuttanad, Kerala, India was screened for the production of bioactive secondary metabolites. This strain was identified as Pseudomonas mosselii through 16S rDNA gene sequencing followed by BLAST analysis and the bioactive metabolites produced were purified by column chromatography (silica gel) and a pure bioactive secondary metabolite was isolated. This bioactive compound was identified as Pseudopyronine B by NMR and HR-ESI-MS. Pseudopyronine B recorded significant antimicrobial activity especially against Gram-positive bacteria and agriculturally important fungi. MTT assay was used for finding cell proliferation inhibition, and Pseudopyronine B recorded significant antitumor activity against non-small cell lung cancer cell (A549), and mouse melanoma cell (B16F10). The preliminary MTT assay results revealed that Pseudopyronine B recorded both dose- and time-dependent inhibition of the growth of test cancer cell lines. Pseudopyronine B induced apoptotic cell death in cancer cells as evidenced by Acridine orange/ethidium bromide and Hoechst staining, and this was further confirmed by flow cytometry analysis using Annexin V. Cell cycle analysis also supports apoptosis by inducing G2/M accumulation in both A549 and B16F10 cells. Pseudopyronine B treated cells recorded significant up-regulation of caspase 3 activity. Moreover, this compound recorded immunomodulatory activity by enhancing the proliferation of lymphocytes. The production of Pseudopyronine B by P. mosselii and its anticancer activity in A549 and B16F10 cell lines is reported here for the first time. The present study has a substantial influence on the information of Pseudopyronine B from P. mosselii as potential sources of novel drug molecule for the pharmaceutical companies, especially as potent antimicrobial and anticancer agent.

Silanated nano ZnO hybrid embedded PMMA polymer coatings on cotton fabrics for near-IR reflective, antifungal cool-textiles

Silanated nano ZnO hybrid embedded PMMA polymer coatings for cotton fabrics are developed to produce near-IR reflective, antifungal cool-textiles.

POLYMORPHISM IN THE CODING REGION SEQUENCE OF GDF8 GENE IN INDIAN SHEEP

The present study was undertaken to identify polymorphism in the coding sequence of GDF8gene across indigenous meat type sheep breeds. A 1647 bp sequence was generated, encompassing 208 bp of the 5'UTR, 1128 bp of coding region (exon1, 2 and 3) as well as 311 bp of 3'UTR. The sheep and goat GDF8 gene sequences were observed to be highly conserved as compared to cattle, buffalo, horse and pig. Several nucleotide variations were observed across coding sequence of GDF8 gene in Indian sheep. Three polymorphic sites were identified in the 5'UTR, one in exon 1 and one in the exon 2 regions. Both SNPs in the exonic region were found to be non-synonymous. The mutations c.539T > G and c.821T > A discovered in this study in the exon 1 and exon 2, respectively, have not been previously reported. The information generated provides preliminary indication of the functional diversity present in Indian sheep at the coding region of GDF8gene. The novel as well as the previously reported SNPs discovered in the Indian sheep warrant further analysis to see whether they affect the phenotype. Future studies will need to establish the affect of reported SNPs in the expression of the GDF8 gene in Indian sheep population.

Reactive oxygen species (ROS) mediated enhanced anti-candidal activity of ZnS–ZnO nanocomposites with low inhibitory concentrations

Enhanced antifungal activity against the yeast species Candida albicans, Candida tropicalis and Saccharomyces cerevisiae was displayed by ZnS–ZnO nanocomposites prepared by a simple precipitation technique.

Nimbolide from Azadirachta indica and its derivatives plus first-generation cephalosporin antibiotics: a novel drug combination for wound-infecting pathogens

We evaluate the in vitro efficacy of nimbolide, desacetylnimbin, and the amide derivatives of nimbolide in combination with first-generation cephalosporin antibiotics against major wound-associated bacterial pathogens.

Effect of Probiotic Lactobacillus salivarius UBL S22 and Prebiotic Fructo-oligosaccharide on Serum Lipids, Inflammatory Markers, Insulin Sensitivity, and Gut Bacteria in Healthy Young Volunteers: A Randomized Controlled Single-Blind Pilot Study

This study investigated the effect of 6-week supplementation of a probiotic strain Lactobacillus salivarius UBL S22 with or without prebiotic fructo-oligosaccharide (FOS) on serum lipid profiles, immune responses, insulin sensitivity, and gut lactobacilli in 45 healthy young individuals. The patients were divided into 3 groups (15/group), that is, placebo, probiotic, and synbiotic. After 6 weeks, a significant reduction (P < .05) in total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides and increase in high-density lipoprotein cholesterol was observed in the probiotic as well as in the synbiotic group when compared to placebo; however, the results of total cholesterol and LDL-cholesterol were more pronounced in the synbiotic group. Similarly, when compared to the placebo group, the serum concentrations of inflammatory markers such as high sensitivity C-reactive protein, interleukin (IL) 6, IL-1β, and tumor necrosis factor α were significantly (P < .05) reduced in both the experimental groups, but again the reduction in the synbiotic group was more pronounced. Also, an increase (P < .05) in the fecal counts of total lactobacilli and a decrease (P < .05) in coliforms and Escherichia coli was observed in both the experimental groups after 6 weeks of ingestion. Overall, the combination of L salivarius with FOS was observed to be more beneficial than L salivarius alone, thereby advocating that such synbiotic combinations could be therapeutically exploited for improved health and quality of life.

Antifungal activity of diketopiperazines and stilbenes against plant pathogenic fungi in vitro

The present study aimed to investigate antifungal activity of a stilbene and diketopiperazine compounds against plant pathogenic fungi, including Phytophthora capsici, P. colocasiae, Botrytis cinerea and Colletotrichum gloeosporioides. Minimal inhibition concentrations (MIC) and minimal fungicidal concentrations (MFC) of stilbenes and diketopiperazines for each fungus were determined using microplate method. Best activity was recorded by stilbenes against P. capsici and P. colocasiae. All four test compounds were effective in inhibiting different stages of the life cycle of test fungi. Stilbenes were more effective than diketopiperazines in inhibiting mycelial growth and inhibiting different stages of the life cycle of P. capsici and P. colocasiae. Rupture of released zoospores induced by stilbenes was reduced by addition of 100 mM glucose. The effects of stilbenes on mycelial growth and zoospore release, but not zoospore rupture, were reduced largely when pH value was above 7. In addition, stilbenes were investigated for its antifungal stability against Phytophthora sp. The results showed that stilbenes maintained strong fungistatic activity over a wide pH range (pH 4–9) and temperature range (70–120 °C). The compound stilbenes exhibited strong and stable broad-spectrum antifungal activity, and had a significant fungicidal effect on fungal cells. Results from prebiocontrol evaluations performed to date are probably useful in the search for alternative approaches to controlling serious plant pathogens.

Embelin (2,5-dihydroxy-3-undecyl-p-benzoquinone): a bioactive molecule isolated from Embelia ribes as an effective photodynamic therapeutic candidate against tumor in vivo

The present study was carried out to assess the photosensitizing potential of embelin, the biologically active natural product isolated from Embelia ribes in photodynamic therapy (PDT) experiments in vivo. In vitro PDT clearly indicated that embelin recorded significant cytotoxicity in Ehrlich's Ascites Carcinoma (EAC) cells, which is superior to 5-aminolevulinic acid, a known photodynamic compound. For in vivo experiments solid tumor was induced using EAC cells in the male Swiss albino mice of groups I, II, III and IV. Group I served as the control (without solid tumor), group II served as tumor bearing mice without treatment and groups III and IV served as treatments. At the completion of 4 weeks of induction, the tumor bearing mice from group III and IV were given an intraperitoneal injection with embelin (12.5mg/kg body weight). After 24h, tumor area in the Group III and IV animals was exposed to visible light from a 1,000 W halogen lamp. The mice from groups I to III were sacrificed 2 weeks after the PDT treatment and the marker enzymes (myeloperoxidase [MPO], β-d-glucuronidase, and rhodanese) were assayed and expression of Bcl-2 and Bax were analyzed in normal and tumor tissues. Animals from group IV were sacrificed after 90 days of PDT treatment and the above mentioned parameters were recorded. Reduction in tumor volume and reversal of biochemical markers to near normal levels were observed in the treated groups. This is the first report on PDT using a natural compound for solid tumor control in vivo. The uniqueness of the mode of treatment lies in the selective uptake of the nontoxic natural compound, embelin from the medicinal plant E. ribes used in Indian system of medicine, by the solid tumor cells and their selective destruction using PDT without affecting the neighboring normal cells, which is much advantageous over radiation therapy now frequently used.

Purification, structural elucidation and bioactivity of tryptophan containing diketopiperazines, from Comamonas testosteroni associated with a rhabditid entomopathogenic nematode against major human-pathogenic bacteria

The cell free culture filtrate of a Comamonas testosteroni associated with an Entomopathogenic nematode (EPN), Rhabditis (Oscheius) sp. exhibited promising antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain five diketopiperazines or cyclic dipeptides (DKP 1-5). The structure and absolute stereochemistry of the compounds were determined based on extensive spectroscopic analyses (HR-MS, (1)HNMR, (13)CNMR, (1)H-(1)H COSY, (1)H-(13)C HMBC) and Marfey's method. Based on the spectral data the compounds were identified as Cyclo-(L-Trp-L-Pro) (1), Cyclo-(L-Trp-L-Tyr) (2), Cyclo-(L-Trp-L-Ile) (3), Cyclo-(L-Trp-L-Leu) (4) and Cyclo-(L-Trp-L-Phe) (5), respectively. Three diketopiperazines (DKP 2, 3 and 5) were active against all the ten bacteria tested. The highest activity of 0.5μg/ml by Cyclo-(L-Trp-L-Phe) was recorded against Vibrio cholerae followed by Salmonella typhi (1 μg/ml) a human pathogen responsible for life threatening diseases like profuse watery diarrhea and typhoid or enteric fever. The activity of this compound against V. cholerae and S. typhi is more effective than ciprofloxacin and ampicillin, the standard antibiotics. Cyclo-(L-Trp-L-Phe) recorded significant antibacterial activity against all the test bacteria when compared to other compounds. Five diketopiperazines were active against all the test fungi and are more effective than bavistin the standard fungicide. Diketopiperazines recorded no cytotoxicity to FS normal fibroblast and VERO cells (African green monkey kidney) except DKP 3 and 4. To our best knowledge this is the first report of antimicrobial activity of the tryptophan containing diketopiperazines against the human pathogenic microbes. The production of cyclic dipeptides by C. testosteroni is also reported here for the first time. We conclude that the C. testosteroni is promising sources of natural bioactive secondary metabolites against human pathogenic bacteria which may receive great benefit in the field of human medicine in near future.

Antimycobacterial activity of cyclic dipeptides isolated from Bacillus sp. N strain associated with entomopathogenic nematode

CONTEXT

Tuberculosis (TB) is one of the leading causes of morbidity and mortality with a global mortality rate of two million deaths per year; one-third of the world's population is infected with Mycobacterium tuberculosis.

OBJECTIVE

The aim of this study was to determine the antimycobacterial activity of six diketopiperazines (DKPs) purified from a Bacillus sp. N strain associated with entomopathogenic nematode Rhabditis (Oscheius) sp.

MATERIALS AND METHODS

The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of DKPs were determined using the broth dilution method on Middlebrook 7H11 against M. tuberculosis H₃₇Rv. Time-kill assay was used to determine the rate of killing of M. tuberculosis H₃₇Rv by DKPs. The cytotoxicity of the DKPs was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against the VERO cell line.

RESULTS

Out of six DKP-tested cyclo-(D-Pro-L-Leu), cyclo-(L-Pro-L-Met) and cyclo-(D-Pro-L-Phe) recorded antimycobacterial activity, the cyclo-(L-Pro-L-Met) showed the highest activity and MIC values of 4 μg/ml for M. tuberculosis H₃₇Rv. The MIC value for rifampicin was 0.06 μg/ml. Growth curve study by the MIC concentration of cyclic dipeptides recorded significant inhibition when compared with control. Time-kill curve showed maximum reduction of colony count was between 3 and 5 weeks. The DKPs are nontoxic to the VERO cell line up to 200 µg/ml. The antimycobacterial activity of cyclo-(D-Pro-L-Leu), cyclo-(L-Pro-L-Met) and cyclo-(D-Pro-L-Phe) is reported in this study for the first time.

DISCUSSION AND CONCLUSION

In conclusion, the potency, low cytotoxicity and selectivity of these compounds make them valid lead compounds for treatment against TB.

Fusarial wilt control and growth promotion of pigeon pea through bioactive metabolites produced by two plant growth promoting rhizobacteria

The bioactive metabolites produced by two plant growth promoting rhizobacteria strains, a Pseudomonas aeruginosa strain RRLJ 04 and a Bacillus cereus strain BS 03, which showed growth promotion and disease control in pigeon pea against Fusarium udum, were isolated and screened for their efficacy to control fusarial wilt of pigeon pea under gnotobiotic and nursery condition. Bioactive metabolites viz., BM 1 and BM 2 from RRLJ 04 and BM 3 from BS 03 also showed in vitro antibiosis against F. udum. Seeds treated with 50 μl seed⁻¹ of BM 1, 30 μl seed⁻¹ of BM 2 and 70 μl seed⁻¹ of BM 3 and grown in pathogen infested soil showed suppression of wilt disease besides growth enhancement. Per cent disease control was 90 % with BM 2 application as compared to 87 and 83 %, respectively in BM 1 and BM 3 after 90 days of growth. BM 2 treated plants were more resistant to the pathogen as compared to the other fractions tested. Mycelial dry weight was found to be reduced on treatment with the bioactive metabolites. Formation of chlamydospore-like structures was observed in the pathogen mycelium treated with BM 3. The analytical studies confirmed that two of these metabolites are phenazine derivatives.

Cyclo(L-Pro-D-Arg): a new antibacterial and antitumour diketopiperazine from Bacillus cereus associated with a rhabditid entomopathogenic

In continuation of our search for new antimicrobial secondary metabolites from Bacillus cereus associated with rhabditid entomopathogenic nematode, a new microbial diketopiperazine, cyclo(L-Pro-D-Arg), was isolated from the ethyl acetate extract of fermented modified nutrient broth. The chemical structures of the isolated compounds were identified based on their 1D, 2D NMR and high-resolution electrospray ionisation-mass spectroscopy data. Antibacterial activity of the compound was determined by minimum inhibitory concentration and disc diffusion method against medically important bacteria, and the compound was recorded to have significant antibacterial activity against test bacteria. The highest activity was recorded against Klebsiella pneumoniae (1 μg/mL). Cyclo(L-Pro-D-Arg) was recorded to have significant antitumor activity against HeLa cells (IC50 value 50 μg/mL), and this compound was recorded to have no cytotoxicity against normal monkey kidney cells (VERO) up to 100 μg/mL). To the best of our knowledge, this is the first time that cyclo(L-Pro-D-Arg) has been isolated from a microbial natural source.

Purification of an antifungal compound, cyclo(l-Pro-d-Leu) for cereals produced by Bacillus cereus subsp. thuringiensis associated with entomopathogenic nematode

Mold spoilage is the main cause of substantial economic loss in cereals and might also cause public health problems due to the production of mycotoxins. The aim of this study was to separate and purify and to identify antifungal compounds of bacterium associated with novel entomopathogenic nematode and check the antifungal property of identified compound in particular food model systems. The antifungal compound was purified using silica gel column chromatography, TLC and HPLC and its structure was elucidated using NMR (¹H NMR, ¹³C NMR, ¹H-¹H COSY, ¹H-¹³C HMBC), HRMS and Marfey's method. Based on the spectral data, the active compounds were identified as diketopiperazine [cyclo(l-Pro-d-Leu)]. The antifungal activity of cyclo(l-Pro-d-Leu) was studied by MIC and paper disk assay against Aspergillus flavus MTCC 277 and Aspergillus niger MTCC 282 and best MIC value of 8μg/ml was recorded against A. flavus. Cyclo(l-Pro-d-Leu) strongly inhibit mycelia growth of fungus and thereby affecting aflatoxin production. To investigate the potential application of the cyclo(l-Pro-d-Leu) and to eliminate fungal spoilage in food and feed, soybean and peanut were used as models. White mycelia and dark/pale green spores of A. flavus were observed in the control soybeans after 2-day incubation. However the fungal growth was not observed in soybeans treated with cyclo(l-Pro-d-Leu). Almost the same result was observed for peanuts treated with cyclo(l-Pro-d-Leu) for A. niger. The cyclo(l-Pro-d-Leu) was nontoxic to two normal human cell lines (FS normal fibroblast and L231 lung epithelial) up to 200μg/ml. Thus the diketopiperazine derivative identified in the study may be a promising alternative to chemical preservatives as a potential biopreservative which prevent fungal growth and mycotoxin formation in food and feed.

In vitro synergistic activity of diketopiperazines alone and in combination with amphotericin B or clotrimazole against Candida albicans

The synergistic anticandidal activity of three diketopiperazines [cyclo-(L-Pro-L-Leu) (1), cyclo-(D-Pro-L-Leu) (2), and cyclo-(D-Pro-L-Tyr) (3)] purified from a Bacillus sp. N strain associated with entomopathogenic nematode Rhabditis (Oscheius) in combination with amphotericin B and clotrimazole was investigated using the macrodilution method. The minimum inhibitory concentration and minimum fungicidal concentration of the diketopiperazines was compared with that of the standard antibiotics. The synergistic anticandidal activities of diketopiperazines with amphotericin B or clotrimazole were assessed using the checkerboard and time-kill methods. The results of the present study showed that the combined effects of diketopiperazines with amphotericin B or clotrimazole predominantly recorded synergistic (<0.5). Time-kill study showed that the growth of the Candida was completely attenuated after 12-24 h of treatment with 50:50 ratios of diketopiperazines and antibiotics. These results suggest that diketopiperazines combined with antibiotics may be microbiologically beneficial and not antagonistic. These findings have potential implications in delaying the development of resistance as the anticandidal effect is achieved with lower concentrations of both drugs (diketopiperazines and antibiotics). The cytotoxicity of diketopiperazines was also tested against two normal human cell lines (L231 lung epithelial and FS normal fibroblast) and no cytotoxicity was recorded for diketopiperazines up to 200 μg/mL. The in vitro synergistic activity of diketopiperazines with antibiotics against Candida albicans is reported here for the first time.

Purification and identification of two antifungal cyclic dipeptides from Bacillus cereus subsp. thuringiensis associated with a rhabditid entomopathogenic nematode especially against Fusarium oxysporum

The cell-free culture filtrate of Bacillus cereus subsp. thuringiensis associated with an entomopathogenic nematode (EPN), Rhabditis (Oscheius) sp., exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain two cyclic dipeptides (CDPs). The structure and absolute stereochemistry of this compound were determined based on extensive spectroscopic analyses (FABMS, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, (1)H-(13)C HMBC) and Marfey's method. The compounds were identified as cyclo(D-Pro-L-Met) and cyclo(D-Pro-D-Tyr). CDPs showed significantly higher activity than the standard fungicide bavistin against agriculturally important fungi, viz., Fusarium oxysporum, Rhizoctonia solani and Penicillium expansum. The highest activity of 2 µg/ml by cyclo(D-Pro-D-Tyr) was recorded against F. oxysporum, a plant pathogen responsible for causing fusarium wilt followed by R. solani, a pathogen that causes root rot and P. expansum. To our knowledge, this is the first report on the isolation of these compounds from Rhabditis EPN bacterial strain Bacillus cereus subsp. thuringiensis.

Activity and synergistic antimicrobial activity between diketopiperazines against bacteria in vitro

The aim of the present study was to determine the synergistic effects of diketopiperazines [cyclo-(L-Pro-L-Leu) (1), cyclo-(D-Pro-L-Leu) (2), and cyclo-(D-Pro-L-Tyr) (3)] purified from a Bacillus sp. N strain associated with entomopathogenic nematode Rhabditis (Oscheius) sp. on the growth of bacteria. The minimum inhibitory concentration and minimum bactericidal concentration of the diketopiperazines was compared with that of the standard antibiotics. The synergistic antibacterial activities of the combination of diketopiperazines against pathogenic bacteria were assessed using the checkerboard assay and time-kill methods. The results of the present study showed that the combination effects of diketopiperazines were predominately synergistic (FIC index <0.5). Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 4-12 h of treatment with 50:50 ratios of diketopiperazines. These results suggest that the combination of diketopiperazines may be microbiologically beneficial. The three diketopiperazines are nontoxic to normal human cell line (L231 lung epithelial) up to 200 m μg/ml. The in vitro synergistic activity of cyclo-(L-Pro-L-Leu), cyclo-(D-Pro-L-Leu), and cyclo-(D-Pro-L-Tyr) against bacteria is reported here for the first time. These findings have potential implications in delaying the development of resistance as the antibacterial effect is achieved with lower concentrations of both drugs (diketopiperazines).

A case of facial lymphoma mimicking dental infection

Infective and neoplastic swellings of the face are common. Often, the differential diagnosis is obvious, but sometimes it can be difficult to ascertain. We report the case of a cheek swelling thought to be infective in origin, but this unusual lesion turned out to be a diffuse large B-cell lymphoma. This was found to be a solitary cutaneous lesion, with associated submandibular lymphadenopathy. The initial plan was for treatment with chemo-radiotherapy, however, the lesion has, surprisingly, begun to resolve spontaneously following biopsy.

CLINICAL RELEVANCE

The most frequent cause of facial swellings presenting to dentists is infective, usually from dental sources, but other causes of facial swelling do need to be considered.

The involvement of matrix glycoproteins in vascular calcification and fibrosis: an immunohistochemical study

Calcification and fibrointimal proliferation are associated with advanced complicated atherosclerosis in large arteries but may also occur in smaller vessels, resulting in ischaemic tissue necrosis. This study investigates whether the mechanisms of calcification and intimal fibrosis are similar in vessels of different sizes. The localization of osteopontin (OPN), matrix Gla protein (MGP), thrombospondin-1 (TSP-1), and cartilage oligomeric matrix protein (COMP) was investigated in three types of human vascular lesions: atherosclerosis, chronic vascular rejection (CVR) in renal allografts, and calcific uraemic arteriolopathy (calciphylaxis). These lesions were chosen as they affect different sized blood vessels and they exhibit a fibroproliferative intimal reaction, with or without calcification, resulting in luminal obliteration and ischaemic complications. OPN, MGP, TSP-1, and COMP were not detected in normal blood vessels. However, OPN and MGP were expressed at sites of calcification within atherosclerotic lesions and in microvessels in calciphylaxis, suggesting that calcification in different sized vessels may occur by a common mechanism. These proteins were not detected in areas of fibrointimal proliferation. In contrast, TSP-1 was localized primarily within the fibrous tissue of atherosclerotic lesions and was also expressed in the expanded fibrous intima of arteries showing CVR. COMP was localized primarily within the fibrous tissue under the lipid core of the majority of advanced atherosclerotic lesions. TSP-1 and COMP were also detected in areas of microcalcification in atherosclerotic lesions and TSP-1 was detected adjacent to areas of calcification in calciphylaxis. However, neither TSP-1 nor COMP was localized to calcific foci within these lesions. The localization of OPN, MGP, TSP-1, and COMP to pathological, but not normal arterial intima supports a pathogenetic role for these proteins in the development of vascular fibrosis and calcification. Modulation of their production and activity may offer a novel approach to the therapy of a number of vascular diseases.

Site A of the MCP-1 distal regulatory region functions as a transcriptional modulator through the transcription factor NF1

The monocyte chemoattractant protein-1 (MCP-1) functions to recruit monocytes and macrophages to areas of inflammation and is a prototypic chemokine subjected to coordinate regulation by immunomodulatory agents. TNF mediated regulation of MCP-1 occurs through a distal regulatory region located 2.5 kb upstream of the transcriptional start site. Within this region are two NF-kB motifs that are each critical for function. Site A, located within the distal regulatory region and upstream of the kappaB elements is required for maximal induction by TNF. However, unlike the kappaB elements and other MCP-1 regulatory elements, Site A is constitutively occupied by factors in vivo. To better understand the nature of Site A function, this report identified a Site A binding protein and provides a functional analysis of the element in driving transcription. The results showed that the transcription factor NF1/CTF binds to Site A both in vitro and in vivo. While Site A has no transcriptional activity on its own, it was found to augment the transcriptional activity of a GAL4-VP16 reporter system in an orientation and position independent manner. Because NF1 is known to interact with factors that modify nucleosomes, these results suggest a unique role for Site A in regulating MCP-1 expression.

Recurrence of Kikuchi's lymphadenitis after 12 years

A 40 year old woman developed recurrent Kikuchi's disease 12 years after the original episode. The recurrence affected the same site (axilla) and occurred after the longest delay so far recorded in a European resident. Care must be taken to avoid misdiagnosis of Kikuchi's disease as lymphoma.

Route of infection that induces a high intensity of gamma interferon-secreting T cells in the genital tract produces optimal protection against Chlamydia trachomatis infection in mice

The induction of local T helper type 1 (Th1)-mediated cellular immunity is crucial for resistance of mice to genital infection by the obligate intracellular bacterium Chlamydia trachomatis. We tested the hypothesis that the route of immunization that elicits relatively high numbers of chlamydia-specific, gamma interferon (IFN-gamma)-secreting T lymphocytes (ISTLs) in the genital tract would induce optimal protective immunity against reinfection. Female BALB/c mice were infected intravaginally (i.v.), intranasally (i.n.), orally (p.o.), or subcutaneously (s.c.) with C. trachomatis. At days 7, 14, 21, and 28 postinfection, T cells isolated from the genital tract tissues were restimulated with chlamydial antigen in vitro, and the amounts of IFN-gamma induced were measured by a sandwiched enzyme-linked immunosorbent assay method. At day 7 postinfection, i.n.- and i.v.-immunized mice had high levels of chlamydia-specific ISTLs in their genital tracts (203.58 +/- 68.1 and 225.5 +/- 12.1 pg/ml, respectively). However, there were no detectable ISTLs in the genital tracts of p.o.- or s.c.-infected mice. When preinfected mice were challenged i.v. 70 days later, animals preexposed by the i.n. route were highly resistant to reinfection, with greatly reduced chlamydial burden, and suffered an attenuated infection that resolved by day 6 postchallenge. Animals preexposed by the i.v. route were modestly protected, whereas p.o. and s.c. groups were indistinguishable in this regard from control mice. The resistance of i.n.-immunized mice (and to some extent the i.v.-exposed mice) to reinfection was associated with early appearance (within 24 h) of high levels of genital ISTLs compared with mice preinfected by other routes. Furthermore, although i.n. and i.v.-immunized mice had comparable levels of chlamydia-specific immunoglobulin A (IgA) antibodies in their vaginal washes, the levels of IgG2a were four- sixfold higher in i.n.-immunized mice than in any of the other groups. The results suggested that immunization routes that foster rapid induction of vigorous genital mucosal cell-mediated immune (CMI) effectors (e.g., IFN-gamma), the CMI-associated humoral effector, IgG2a, and to some extent secretory IgA produce protective immunity against chlamydial genital infection. Therefore, i.n. immunization is a potential delivery route of choice in the development of a vaccine against Chlamydia.

Chlamydial infection in inducible nitric oxide synthase knockout mice

Type 1 CD4+-T-cell-mediated immunity is crucial for the resolution of chlamydial infection of the murine female genital tract. Previous studies demonstrating a correlation between CD4+-T-cell-mediated inhibition of chlamydial growth and gamma interferon (IFN-gamma)-mediated induction of nitric oxide synthase suggested a potential role for the nitric oxide (NO) effector pathway in the clearance of Chlamydia from genital epithelial cells by the immune system. To clarify the role of this pathway, the growth levels of Chlamydia trachomatis organisms in normal (iNOS+/+) mice and in genetically engineered mice lacking the inducible nitric oxide synthase (iNOS) gene (iNOS-/- mice) were compared. There was no significant difference in the course of genital chlamydial infections in iNOS+/+ and iNOS-/- mice as determined by recovery of Chlamydia organisms shed from genital epithelial cells. Dissemination of Chlamydia to the spleen and lungs occurred to a greater extent in iNOS-/- than in iNOS+/+ mice, which correlated with a marginal increase in the susceptibility of macrophages from iNOS-/- mice to chlamydial infection in vitro. However, infections were rapidly cleared from all affected tissues, with no clinical signs of disease. The finding of minimal dissemination in iNOS-/- mice suggested that activation of the iNOS effector pathway was not the primary target of IFN-gamma during CD4+-T-cell-mediated control of chlamydial growth in macrophages because previous reports demonstrated extensive and often fatal dissemination of Chlamydia in mice lacking IFN-gamma. In summary, these results indicate that the iNOS effector pathway is not required for elimination of Chlamydia from epithelial cells lining the female genital tract of mice although it may contribute to the control of dissemination of C. trachomatis by infected macrophages.

Vascular injuries in total knee arthroplasty. A review of the problem with special reference to the possible effects of the tourniquet

Considering the proximity of the major vascular structures to the back of the knee, vascular complications of total knee arthroplasty are relatively rare. A patient who developed acute vascular insufficiency immediately following a total knee arthroplasty is reported. This stimulated a survey of arterial complications encountered by members of the British Association for the Surgery of the Knee. The majority of surgeons still use a tourniquet but will modify their practice if there is anxiety about vascular status. The mechanism of injury to the vascular system is either direct trauma or thrombosis. The outcome following treatment after direct injury is extremely good. The outcome after thrombosis is extremely poor. There is no recorded case of thrombosis occurring when a tourniquet was not used. Whether all knee arthroplasties should be done without a tourniquet is discussed. Early intervention is vital if a vascular injury is suspected.

Enhanced photosynthesis in cytozyme-treated blackgram, Phaseolus mungo L

Foliar application of cytozyme to 30-day-old black-gram plants resulted 48% increase of dry matter accumulation. The increase in fresh and dry weights of total plants was largely due to enhanced CO2 assimilation rates which were associated with increased RuBP carboxylase activities. The photochemical characteristics in the isolated chloroplasts exhibited an increase of 32, 28 and 40%, measured as the photoreduction of DCPIP, FeCN and NADP, respectively. Cytozyme treatment also resulted an increase in the chlorophyll content in leaves.

Ecosystem studies on upper region of Ganga River, India

A multi-disciplinary research programme on the Ganga River Ecosystem was launched by the Government of India in 1983 to collect information on its attributes. Monitoring of the initial 509 km unpolluted and unmonitored region of the river falling in partly mountainous and partly upper plain stretches for two years revealed good water quality. The Song River (a tributary) catchment, a victim of extensive mining activity in the past, was found to add maximum mineral load. The Bhagirathi River was found to carry maximum suspended solid load. Organic pollution was low throughout, occasionally showing seasonal and local peaks. The river exhibited a high oxidative state with pH falling in a slightly alkaline range and nutrient levels being very low.Diatoms formed a major part of the encountered genera of phytoplankton. Zooplankton were mainly represented by protozoans. Saprophytic bacteria underwent large spatial and temporal fluctuations. Coliforms exhibited an increasing trend with downstream river distance. The source of pollution could not be specifically characterized from an FC/FS ratio. Only one sample tested positive for enteric virus. The forms of benthic macroinvertebrates indicated a clean stream environment. It was observed that diversity indices, together with evenness and community comparison, could provide a promising approach to determine the state of the community.Eight heavy metals investigated, Cu, Zn, Fe, Cd, Mn, Pb, Ni and Co, were found to be present in the river water and bed sediments. The prominent mode of metal transport was found to be via the suspended load. The concentration of dissolved metals was found within WHO permissible limits. The heavy metal status of the Ganga River was compared with other rivers of the world. Sorptive properties of sediments were found to be similar to the general sorptive behaviour of the clays. Laboratory studies exhibited reasonable short t 90 values for coliform survival in Ganga water. Faecal streptococcus survived longer.

Complete genomic sequence and phylogenetic analysis of the lactate dehydrogenase-elevating virus (LDV)

The apparently complete sequence of the RNA genome of the neurovirulent isolate of lactate dehydrogenase-elevating virus (LDV-C) has been determined. The LDV-C genome is at least 14,222 nucleotides in length and contains eight open reading frames (ORFs). ORF 1a, which encodes a protein of 242.8 kDa and is located at the 5' end of the genome, contains at least two putative papain-like cysteine protease domains, and one putative chymotrypsin-like serine protease domain. This ORF terminates with a UAG stop codon that can be bypassed if a -1 frameshift occurs. The frameshift region consists of a heptanucleotide "slippery" sequence, 5'-UUUAAAC-3', followed by a putative pseudoknot. ORF 1b encodes a protein of 155.4 kDa containing, in its N-terminal portion, an RNA-dependent RNA polymerase and an RNA helicase domain separated by a Zn finger domain. Another domain of unknown function that is also conserved in coronaviruses and toroviruses is located at the C-terminus of the ORF 1b product. Three cleavage sites in the ORF 1a polyprotein and three in the ORF 1b polyprotein were predicted for the chymotrypsin-like protease and tentatively delimit the mature nonstructural proteins of LDV. Six small, overlapping 3' ORFs (ORFs 2 through 7) encode proteins with calculated sizes of 25.8, 21.6, 19.8, 23.9, 18.9, and 12.3 kDa. ORF 7 encodes the virion nucleocapsid protein Vp-1, while ORF 6 encodes the nonglycosylated envelope protein Vp2. ORFs 5, 4, 3, and 2 each encode glycoproteins which may be virion envelope proteins. LDV is closely related to equine arteritis virus, Lelystad virus (LV), and simian hemorrhagic fever virus. These four viruses belong to a new group of positive-strand RNA viruses and are related to coronaviruses and toroviruses.

Immunohistochemical comparison of T-cell and macrophage populations in mammary tissue of control and Trichinella spiralis-infected rats

We have shown that antigen-specific T lymphocytes can mediate maternal-to-neonatal immunity during lactation. Present studies address the dynamics of lymphocyte accumulation in the mammary gland during normal and disease stimulated conditions. Monoclonal antibodies specific for total T cells, suppressor/cytotoxic and helper subsets, and macrophages were used in conjunction with immunohistochemistry to identify and count the individual cell types. In unstimulated mammary tissue, following a rise in T cells to maximal numbers in late pregnancy, the total number of T cells/high power field (HPF) was significantly diminished in early lactation and continued to decline to the late lactation period. Both the numbers of T cells/HPF located in the mammary alveolar epithelium and surrounding connective tissue were significantly reduced in early lactation as compared to late pregnancy. This indicates the possible passage of cells into the milk during lactation. Prior infection of the mother with Trichinella spiralis and a secondary challenge 48 h. before sacrifice caused a significant reduction in the number of T cells in the mammary tissue in early lactation as compared with unstimulated controls, indicating the possibility of an even greater outflow of T cells into milk. In controls, the T-suppressor/cytotoxic subtype showed a reduction in early lactation versus late pregnancy but showed no shifts in total cells/HPF during infection. The T-helper subtype in controls remained unchanged from late pregnancy to early lactation with a considerable decline in late lactation. However, the T-helper cells were significantly decreased in T. spiralis-treated animals as compared with noninfected controls in early lactation.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of T cell subsets in the maternal-to-neonatal transmission of immunity against Trichinella spiralis during lactation in rats

We have previously demonstrated the maternal-to-neonatal transfer of immunity to T. spiralis during lactation and have shown that antigen-specific T lymphocytes, when injected into the mother or orally fed to neonates, can mediate this transfer. To further analyze the T cell subsets involved in conferring this protection, T lymphocytes were isolated from the mesenteric lymph nodes of syngeneic donor rats infected 4-6 days earlier with T. spiralis. The T cells were incubated in vitro with either mouse-anti-rat 0X8 or W3/25 monoclonal antibody, "panned" on plates coated with goat-anti-mouse Ig, and the non-adherent T helper or T cytotoxic/suppressor cells harvested. 100 x 10(6) T helper cells were injected i.v. into mothers once in early lactation and again two days prior to challenging their pups (200 T. spiralis larvae) at 2 weeks of age. This resulted in significant passage of immunity from the mothers to their suckling neonates, worm counts being 59% and 73% of control values 3 and 8 days post-challenge (P less than 0.01). Injection of T-cytotoxic/suppressor cells using the same regimen resulted in significant suppression of immunity in challenged pups, who retained worm counts that were 105% and 145% of control values at 3 and 8 days post-challenge. Synergy between recombined panned T-helper and T cytotoxic/suppressor cells without Ly1+2+3+ amplifier cells was tested by recombining non-adherent panned 0X8 and W3/25 cells. This resulted in no significant expressions of immunity in the pups when compared to controls. The presence of transferred maternal T cells within the neonate was evidenced by the fact that neonates (nursing on immune mothers) had significant (P less than 0.01) delayed footpad reactions to a crude T. spiralis antigen preparation, as compared with neonates nursing on non-immune controls.

The effects of ethanol consumption on the expression of immunity to Trichinella spiralis in rats

The effects of ethanol ingestion on immune responses of female rats against Trichinella spiralis (T. spiralis) infections were investigated. Female rats were pair-fed either ethanol-containing or isocaloric control liquid diets for 68 days, during which time they underwent one pregnancy cycle. For some studies, animals were fed ethanol diets for 68 days beginning prior to pregnancy and continuing through lactation and involution. They were infected on Day 7 of involution with 1000 L1 larvae of T. spiralis and tested for a primary rejection response 10 days later. To test for a secondary immune response, rats were infected with T. spiralis, placed on ethanol-containing liquid diet 15 days later, and after 68 days on diets, challenged with 1000 T. spiralis larvae and killed 3 days later. For primary immunized studies, ethanol-treated animals demonstrated significantly lower levels of anti-T. spiralis serum antibodies in ELISA, reduced rates of H3 thymidine incorporation by lymph node cells stimulated with T. spiralis antigen and significantly higher numbers of intestinal worm burdens (decreased immunity) compared with pair-fed controls. For animals sensitized to T. spiralis prior to pregnancy and given a secondary challenge during involution, no differences were found between ethanol and pair-fed animals in their ability to reject their worm burdens or in anti-T. spiralis serum antibody levels; however, ethanol-treated animals showed reduced rates of thymidine incorporation by lymph node cells when stimulated with T. spiralis antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Area normalization of the renal region of interest in radionuclide renography data analysis: a misconception

Relative renal function is estimated by comparing the area under the second segment of the curve from the renal region of interest in a renographic study. We have examined the problems arising out of area normalization of the renal region of interest in the data analysis for relative renal function evaluation. Error analysis by computer simulation proves that this method of data analysis is highly misleading and erroneous.

Maternal to neonatal transmission of T-cell mediated immunity to Trichinella spiralis during lactation

The potential of maternally derived cellular factors to mediate immunity to Trichinella spiralis in neonates during lactation was investigated in this study. Female FI rats, infected with T. spiralis, were able to transfer immunity to their suckling offspring, evidenced by a significant reduction in the intestinal parasite burdens of their neonates. When challenged between 2 and 3 weeks of age with 200 T. spiralis larvae, pups suckling on immune mothers harboured 28% and 26% (at 3 and 8 days post-challenge) of the worm numbers present in control neonates suckling on naive mothers. Cross-fostering experiments in which pups born of naive mothers but nursed by immune mothers showed significant immunity, demonstrated that this passage occurred through milk. The role of cell-mediated immunity in this immune transfer was analysed using T cells purified from MLN cells of syngeneic donor rats infected with T. spiralis. When 200 x 10(6) sensitized MLN T cells were adoptively transferred into lactating recipients, it led to the passive immunization of suckling neonates (26% and 13% of control values retained at 3 and 8 days post-challenge), while maternal injection of T cells primed to an irrelevant antigen (KLH) had no effect on neonatal immunity. Neonates fed per-orally with primed T lymphocytes early in lactation and prior to challenge were also rendered immune (34% and 44% of control values retained at 3 and 8 days post-challenge). A single dose of T. spiralis-primed T cells given to neonates in early lactation was sufficient to elicit a significant immune response in them at 2 weeks of age. These results support the hypothesis that cellular immunity mediated by antigen-specific T cells in milk can provide functional immune protection to the neonate against an intestinal pathogen.