Longitudinal assessment of tumor-infiltrating lymphocytes in primary breast cancer following neoadjuvant radiotherapy

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have prognostic significance in several cancers, including breast. Despite interest in combining radiotherapy with immunotherapy, little is known about the effect of radiotherapy itself on the tumor-immune microenvironment, including TILs. Here, we interrogated longitudinal dynamics of tumor-infiltrating and systemic lymphocytes in patient samples taken before, during, and after neoadjuvant radiotherapy (NART), from XXX and XXX breast clinical trials.

METHODS

We manually scored stromal TILs (sTILs) from longitudinal tumor samples using standardized guidelines, as well as deep learning-based scores at cell-level (cTIL) and cell- and tissue-level combination analysis (SuperTIL). In parallel, we interrogated absolute lymphocyte counts from routine blood tests at corresponding timepoints during treatment. Exploratory analyses studied the relationship between TILs and pathological complete response (pCR) and long-term outcomes.

RESULTS

Patients receiving NART experienced a significant and uniform decrease in sTILs that did not recover at the time of surgery (P < 0.0001). This lymphodepletive effect was also mirrored in peripheral blood. Our "SuperTIL" deep learning score showed good concordance with manual sTILs, and importantly performed comparably to manual scores in predicting pCR from diagnostic biopsies. Analysis suggested an association between baseline sTILs and pCR, as well as sTILs at surgery and relapse, in patients receiving NART.

CONCLUSIONS

This study provides novel insights into TIL dynamics in the context of NART in breast cancer, and demonstrates the potential for artificial intelligence to assist routine pathology. We have identified trends which warrant further interrogation and have a bearing on future radio-immunotherapy trials.

Applicability of Scoring Calyculin A-Induced Premature Chromosome Condensation Objects for Dose Assessment Including for Radiotherapy Patients

As an extension to a previous study, a linear calibration curve covering doses from 0 to 10 Gy was constructed and evaluated in the present study using calyculin A-induced premature chromosome condensation (PCC) by scoring excess PCC objects. The main aim of this study was to assess the applicability of this PCC assay for doses below 2 Gy that are critical for triage categorization. Two separate blind tests involving a total of 6 doses were carried out; 4 out of 6 dose estimates were within the 95% confidence limits (95% CL) with the other 2 just outside. In addition, blood samples from five cancer patients undergoing external beam radiotherapy (RT) were also analyzed, and the results showed whole-body dose estimates statistically comparable to the dicentric chromosome assay (DCA) results. This is the first time that calyculin A-induced PCC was used to analyze clinical samples by scoring excess objects. Although dose estimates for the pre-RT patient samples were found to be significantly higher than the mean value for the healthy donors and were also significantly higher than those obtained using DCA, all these pre-treatment patients fell into the same category as those who may have received a low dose (<1 Gy) and do not require immediate medical care during emergency triage. Additionally, for radiological accidents with unknown exposure scenario, PCC objects and rings can be scored in parallel for the assessment of both low- and high-dose exposures. In conclusion, scoring excess objects using calyculin A-induced PCC is confirmed to be another potential biodosimetry tool in radiological emergency particularly in mass casualty scenarios, even though the data need to be interpreted with caution when cancer patients are among the casualties.

Microplastic contamination in edible sea salt from the largest salt-producing states of India

The presence of microplastics in all ecological and environmental conditions has been identified as a global problem. This article aimed to study edible salt-associated microplastics from the major salt-producing states of India. The crystal and powder salt from Tamil Nadu and Gujarat (five samples of powder salt and three samples of crystal salt from each state) were collected and analyzed for their microplastic content. The total microplastic content in the salts ranged from 46 to 115 particles per 200 g in Gujarat salt and 23 to 101 particles per 200 g in Tamil Nadu salt. The microplastics are dominated by red and blue color fibrous-shaped materials. The most common microplastics identified in the edible salts were polyethylene, polyester, and polyvinyl chloride derived from marine and salt-processing units.

An ionising radiation-induced specific transcriptional signature of inflammation-associated genes in whole blood from radiotherapy patients: a pilot study

BACKGROUND

This communication reports the identification of a new panel of transcriptional changes in inflammation-associated genes observed in response to ionising radiation received by radiotherapy patients.

METHODS

Peripheral blood samples were taken with ethical approval and informed consent from a total of 20 patients undergoing external beam radiotherapy for breast, lung, gastrointestinal or genitourinary tumours. Nanostring nCounter analysis of transcriptional changes was carried out in samples prior and 24 h post-delivery of the 1st radiotherapy fraction, just prior to the 5th or 6th fraction, and just before the last fraction.

RESULTS

Statistical analysis with BRB-ArrayTools, GLM MANOVA and nSolver, revealed a radiation responsive panel of genes which varied by patient group (type of cancer) and with time since exposure (as an analogue for dose received), which may be useful as a biomarker of radiation response.

CONCLUSION

Further validation in a wider group of patients is ongoing, together with work towards a full understanding of patient specific responses in support of personalised approaches to radiation medicine.

TP53 modulates radiotherapy fraction size sensitivity in normal and malignant cells

Recent clinical trials in breast and prostate cancer have established that fewer, larger daily doses (fractions) of radiotherapy are safe and effective, but these do not represent personalised dosing on a patient-by-patient basis. Understanding cell and molecular mechanisms determining fraction size sensitivity is essential to fully exploit this therapeutic variable for patient benefit. The hypothesis under test in this study is that fraction size sensitivity is dependent on the presence of wild-type (WT) p53 and intact non-homologous end-joining (NHEJ). Using single or split-doses of radiation in a range of normal and malignant cells, split-dose recovery was determined using colony-survival assays. Both normal and tumour cells with WT p53 demonstrated significant split-dose recovery, whereas Li-Fraumeni fibroblasts and tumour cells with defective G1/S checkpoint had a large S/G2 component and lost the sparing effect of smaller fractions. There was lack of split-dose recovery in NHEJ-deficient cells and DNA-PKcs inhibitor increased sensitivity to split-doses in glioma cells. Furthermore, siRNA knockdown of p53 in fibroblasts reduced split-dose recovery. In summary, cells defective in p53 are less sensitive to radiotherapy fraction size and lack of split-dose recovery in DNA ligase IV and DNA-PKcs mutant cells suggests the dependence of fraction size sensitivity on intact NHEJ.

Intratumoral Hydrogen Peroxide With Radiation Therapy in Locally Advanced Breast Cancer: Results From a Phase 1 Clinical Trial

PURPOSE

Hydrogen peroxide (H2O2) plays a vital role in normal cellular processes but at supraphysiological concentrations causes oxidative stress and cytotoxicity, a property that is potentially exploitable for the treatment of cancer in combination with radiation therapy (RT). We report the first phase 1 trial testing the safety and tolerability of intratumoral H2O2 + external beam RT as a novel combination in patients with breast cancer and exploratory plasma marker analyses investigating possible mechanisms of action.

METHODS AND MATERIALS

Twelve patients with breast tumors ≥3 cm (surgically or medically inoperable) received intratumoral H2O2 with either 36 Gy in 6 twice-weekly fractions (n = 6) or 49.5 Gy in 18 daily fractions (n = 6) to the whole breast ± locoregional lymph nodes in a single-center, nonrandomized study. H2O2 was mixed in 1% sodium hyaluronate gel (final H2O2 concentration 0.5%) before administration to slow drug release and minimize local discomfort. The mixture was injected intratumorally under ultrasound guidance twice weekly 1 hour before RT. The primary endpoint was patient-reported maximum intratumoral pain intensity before and 24 hours postinjection. Secondary endpoints included grade ≥3 skin toxicity and tumor response by ultrasound. Blood samples were collected before, during, and at the end of treatment for cell-death and immune marker analysis.

RESULTS

Compliance with H2O2 and RT was 100%. Five of 12 patients reported moderate pain after injection (grade 2 Common Terminology Criteria for Adverse Events v4.02) with median duration 60 minutes (interquartile range, 20-120 minutes). Skin toxicity was comparable to RT alone, with maintained partial/complete tumor response relative to baseline in 11 of 12 patients at last follow-up (median 12 months). Blood marker analysis highlighted significant associations of TRAIL, IL-1β, IL-4, and MIP-1α with tumor response.

CONCLUSIONS

Intratumoral H2O2 with RT is well tolerated with no additional toxicity compared with RT alone. If efficacy is confirmed in a randomized phase 2 trial, the approach has potential as a cost-effective radiation response enhancer in multiple cancer types in which locoregional control after RT alone remains poor.

Bioavailable trace metals and their ecological risks in the tourist beaches of the Southeast coast of India

The concentration of Acid Leachable Trace Metals (ALTMs) was assessed in urbanized tourist beaches (96 samples from Marina beach, 34 samples from Edward Elliot's beach, and 28 samples from Silver beach) of southeast coast of India. The concentration of metals accumulated in the beach sediment was less than the Upper Continental Crust (UCC) background reference values. The mean enrichment of ALTMs in the studied urban tourist beaches showed the following descending order: Marina beach - Cr > Pb > Ni > Zn > Cu > Mn > Co; Edward Elliot's beach - Cr > Pb > Ni > Mn > Co > Zn > Cu; Silver beach - Cr > Pb > Ni > Co > Mn > Cu > Zn. The ALTMs such as Fe, Mn, Co, Cu, and Zn were probably derived from natural weathering and mild anthropogenic influences whereas other metals were derived from anthropogenic induced factors.

A baseline study on elemental concentration and potential ecological risk status of the surface sediments of Ashtamudi Lake, south west coast of India

Element concentration (Fe, Mn, Pb, Zn, Cu, Cr, Ni and Co) in the surface sediments of Ashtamudi estuary, Southwest coast of India, has been analyzed to understand the spatial variation and potential ecological risk status. The sediment pollution index and Potential Ecological Risk index suggest that the northeastern part of the estuary exhibits low to moderate polluted sediments with moderate ecological risk. The results of correlation analysis indicate that the natural weathering process and river input play an important role in the distribution of the elements in the surface sediments of the estuary. The extracted factor results indicate that the fine sediment fractions supporting for accumulation of the trace elements, whereas the enriched level of Fe and Mn is chiefly controlled by the riverine process, and other elements are contributed by anthropogenic influences.

Radiosensitization In Vivo by Histone Deacetylase Inhibition with No Increase in Early Normal Tissue Radiation Toxicity

As the population ages, more elderly patients require radiotherapy-based treatment for their pelvic malignancies, including muscle-invasive bladder cancer, as they are unfit for major surgery. Therefore, there is an urgent need to find radiosensitizing agents minimally toxic to normal tissues, including bowel and bladder, for such patients. We developed methods to determine normal tissue toxicity severity in intestine and bladder in vivo, using novel radiotherapy techniques on a small animal radiation research platform (SARRP). The effects of panobinostat on in vivo tumor growth delay were evaluated using subcutaneous xenografts in athymic nude mice. Panobinostat concentration levels in xenografts, plasma, and normal tissues were measured in CD1-nude mice. CD1-nude mice were treated with drug/irradiation combinations to assess acute normal tissue effects in small intestine using the intestinal crypt assay, and later effects in small and large intestine at 11 weeks by stool assessment and at 12 weeks by histologic examination. In vitro effects of panobinostat were assessed by qPCR and of panobinostat, TMP195, and mocetinostat by clonogenic assay, and Western blot analysis. Panobinostat resulted in growth delay in RT112 bladder cancer xenografts but did not significantly increase acute (3.75 days) or 12 weeks' normal tissue radiation toxicity. Radiosensitization by panobinostat was effective in hypoxic bladder cancer cells and associated with class I HDAC inhibition, and protein downregulation of HDAC2 and MRE11. Pan-HDAC inhibition is a promising strategy for radiosensitization, but more selective agents may be more useful radiosensitizers clinically, resulting in fewer systemic side effects. Mol Cancer Ther; 17(2); 381-92. ©2017 AACRSee all articles in this MCT Focus section, "Developmental Therapeutics in Radiation Oncology."

The anti-malarial atovaquone increases radiosensitivity by alleviating tumour hypoxia

Tumour hypoxia renders cancer cells resistant to cancer therapy, resulting in markedly worse clinical outcomes. To find clinical candidate compounds that reduce hypoxia in tumours, we conduct a high-throughput screen for oxygen consumption rate (OCR) reduction and identify a number of drugs with this property. For this study we focus on the anti-malarial, atovaquone. Atovaquone rapidly decreases the OCR by more than 80% in a wide range of cancer cell lines at pharmacological concentrations. In addition, atovaquone eradicates hypoxia in FaDu, HCT116 and H1299 spheroids. Similarly, it reduces hypoxia in FaDu and HCT116 xenografts in nude mice, and causes a significant tumour growth delay when combined with radiation. Atovaquone is a ubiquinone analogue, and decreases the OCR by inhibiting mitochondrial complex III. We are now undertaking clinical studies to assess whether atovaquone reduces tumour hypoxia in patients, thereby increasing the efficacy of radiotherapy.

Mechanisms and consequences of ATMIN repression in hypoxic conditions: roles for p53 and HIF-1

Hypoxia-induced replication stress is one of the most physiologically relevant signals known to activate ATM in tumors. Recently, the ATM interactor (ATMIN) was identified as critical for replication stress-induced activation of ATM in response to aphidicolin and hydroxyurea. This suggests an essential role for ATMIN in ATM regulation during hypoxia, which induces replication stress. However, ATMIN also has a role in base excision repair, a process that has been demonstrated to be repressed and less efficient in hypoxic conditions. Here, we demonstrate that ATMIN is dispensable for ATM activation in hypoxia and in contrast to ATM, does not affect cell survival and radiosensitivity in hypoxia. Instead, we show that in hypoxic conditions ATMIN expression is repressed. Repression of ATMIN in hypoxia is mediated by both p53 and HIF-1α in an oxygen dependent manner. The biological consequence of ATMIN repression in hypoxia is decreased expression of the target gene, DYNLL1. An expression signature associated with p53 activity was negatively correlated with DYNLL1 expression in patient samples further supporting the p53 dependent repression of DYNLL1. Together, these data demonstrate multiple mechanisms of ATMIN repression in hypoxia with consequences including impaired BER and down regulation of the ATMIN transcriptional target, DYNLL1.

Spatio-temporal dynamics of mosquitoes in stream pools of a biosphere reserve of Southern Western Ghats, India

The spatial and temporal dynamics of mosquitoes in stream pools were examined in a biosphere reserve of the Southern Western Ghats, India. The immature mosquitoes in stream pools were collected from stream substrates of bedrock pool, boulder cavity and sand puddle. The collected larvae and pupae were reared and identified. In total, 16 species from four genera of mosquitoes were collected. The mosquito species from Culex and Anopheles were predominantly occurred. The bedrock pool had the highest diversity and abundance of mosquitoes. The statistical analyses showed that the substrate specificity and the seasons were positively related to the distribution of mosquitoes rather than spatial pattern. This study described the spatial and temporal pattern of mosquitoes in stream pools of the Southern Western Ghats. This information would be helpful to National Vector borne disease control program for surveillance and control.

In Vitro Radiosensitization of Esophageal Cancer Cells with the Aminopeptidase Inhibitor CHR-2797

With the increased incidence of esophageal cancer, chemoradiotherapy continues to play an important role in the management of this disease. Developing potent radiosensitizers is therefore critical for improving outcomes. The use of drugs that have already undergone clinical testing is an appealing approach once the side effects and tolerated doses are established. Here, we demonstrate that the aminopeptidase inhibitor, CHR-2797/tosedostat, increases the radiosensitivity of esophageal cancer cell lines (FLO-1 and OE21) in vitro in both normoxic and physiologically relevant low oxygen conditions. To our knowledge, the effective combination of CHR-2797 with radiation exposure has not been reported previously in any cancer cell type. The mechanism of increased radiosensitivity was not dependent on the induction of DNA damage or DNA repair kinetics. Our data support the need for further preclinical testing of CHR-2797 in combination with radiotherapy for the treatment of esophageal cancer.

Simulium (Gomphostilbia) (Diptera: Simuliidae) from Southern Western Ghats, India: two new species and DNA barcoding

Two new species of Simulium (Gomphostilbia) (Diptera: Simuliidae) are described on the basis of reared adult, pupal and larval specimens collected from Southern Western Ghats India. The morphological data of two new species S. (Gomphostilbia) panagudiense sp. n. and S. (Gomphostilbia) kottoorense sp. n. are assigned to the batoense species group in the subgenus Gomphostilbia. S. (Gomphostilbia) panagudiense sp.n. is characterized in the female by having the scutum without longitudinal vitta and arms of the genital fork wide basally and in the pupa by the stalk of ventral pair medium-long. S. (Gomphostilbia) kottoorense sp.n. is characterized by the arm of genital fork tapered near apex in the female and style in medial view 0.63 times as long as coxite in the male. Phylogeny of members in the genus Simulium was reconstructed based on DNA barcoding gene (cytochrome oxidase c subunit I). Tree analysis using new technology and maximum likelihood analyses are congruent with evidence of two new species in the subgenus Gomphostilbia and separated from other species.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage-induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain-containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors.

Replication stress and chromatin context link ATM activation to a role in DNA replication

ATM-mediated signaling in response to DNA damage is a barrier to tumorigenesis. Here we asked whether replication stress could also contribute to ATM signaling. We demonstrate that, in the absence of DNA damage, ATM responds to replication stress in a hypoxia-induced heterochromatin-like context. In certain hypoxic conditions, replication stress occurs in the absence of detectable DNA damage. Hypoxia also induces H3K9me3, a histone modification associated with gene repression and heterochromatin. Hypoxia-induced replication stress together with increased H3K9me3 leads to ATM activation. Importantly, ATM prevents the accumulation of DNA damage in hypoxia. Most significantly, we describe a stress-specific role for ATM in maintaining DNA replication rates in a background of increased H3K9me3. Furthermore, the ATM-mediated response to oncogene-induced replication stress is enhanced in hypoxic conditions. Together, these data indicate that hypoxia plays a critical role in the activation of the DNA damage response, therefore contributing to this barrier to tumorigenesis.

Radiosensitization of renal cell carcinoma in vitro through the induction of autophagy

BACKGROUND AND PURPOSE

For patients diagnosed with advanced renal cell carcinoma (RCC), there are few therapeutic options. Radiation therapy is predominantly used to treat metastasis and has not proven effective in the adjuvant setting for renal cancer. Furthermore, RCC is resistant to standard cytotoxic chemotherapies. Targeted anti-angiogenics are the standard of care for RCC but are not curative. Newer agents, such as mTOR inhibitors and others that induce autophagy, have shown great promise for treating RCC. Here, we investigate the potential use of the small molecule STF-62247 to modulate radiation.

MATERIALS AND METHODS

Using RCC cell lines, we evaluate sensitivity to radiation in addition to agents that induce autophagic cell death by clonogenic survival assays. Furthermore, these were also tested under physiological oxygen levels.

RESULTS

STF-62247 specifically induces autophagic cell death in cells that have lost VHL, an essential mutation in the development of RCC. Treatment with STF-62247 did not alter cell cycle progression but when combined with radiation increased cell killing under oxic and hypoxic/physiological conditions.

CONCLUSIONS

This study highlights the possibility of combining targeted therapeutics such as STF-62247 or temsirolimus with radiation to reduce the reliance on partial or full nephrectomy and improve patient prognosis.

A novel method for autophagy detection in primary cells: impaired levels of macroautophagy in immunosenescent T cells

Autophagy is a conserved constitutive cellular process, responsible for the degradation of dysfunctional proteins and organelles. Autophagy plays a role in many diseases such as neurodegeneration and cancer; however, to date, conventional autophagy detection techniques are not suitable for clinical samples. We have developed a high throughput, statistically robust technique that quantitates autophagy in primary human leukocytes using the Image stream, an imaging flow cytometer. We validate this method on cell lines and primary cells knocked down for essential autophagy genes. Also, using this method we show that T cells have higher autophagic activity than B cells. Furthermore our results indicate that healthy primary senescent CD8(+) T cells have decreased autophagic levels correlating with increased DNA damage, which may explain features of the senescent immune system and its declining function with age. This technique will allow us, for the first time, to measure autophagy levels in diseases with a known link to autophagy, while also determining the contribution of autophagy to the efficacy of drugs.

Spatio-temporal dynamics of caddisflies in streams of southern Western Ghats

The dynamics of physico-chemical factors and their effects on caddisfly communities were examined in 29 streams of southern Western Ghats. Monthly samples were collected from the Thadaganachiamman stream of Sirumalai Hills, Tamil Nadu from May 2006 to April 2007. Southwest and northeast monsoons favored the existence of caddisfly population in streams. A total of 20 caddisfly taxa were collected from 29 streams of southern Western Ghats. Hydropsyche (Trichoptera: Hydropsychidae) were more widely distributed throughout sampling sites than were the other taxa. Canonical correspondence analysis showed that elevation was a major variable and pH, stream order, and stream substrates were minor variables affecting taxa richness. These results suggested that habitat heterogeneity and seasonal changes were stronger predictors of caddisfly assemblages than large-scale patterns in landscape diversity.

Macroinvertebrate colonization and breakdown of leaves in an astatic pond in south India

Macroinvertebrate colonization and breakdown of Pongamia pinnata and Morinda tinctoria leaves were studied in an astatic pond in Madura College, Madurai. Morinda tinctoria leaves broke down fasterthan the leaves of P. pinnata. Breakdown capacities of astatic pond cannot be attributed to colonization of macroinvertebrates. Instead, microbial processing, and abiotic fragmentation are suggested as factors controlling breakdown rates. Tanypus sp (midgelarva) was abundant in leaf bags during the experimental period. This midge-larva appeared to use litter accumulations as a microhabitat that provided shelter and a rich supply of food in the form of organic matter Their abundance and regular occurrence of two leaves suggest that midge larvae enhance leaf fragmentation and possibly mediate the incorporation of organic matter in pond sediments once the plant tissue is sufficiently macerated.

Anthropogenic impacts on aquatic insects in six streams of South Western ghats

Diversity patterns of aquatic insects among sampling sites lying with!ç the unprotected and protected areas of Western Ghats were studied. This study primarily emphasizes whether anthropogenic influence is the prime cause for the presence of aquatic insects especially of pollution-sensitive organisms belonging to the orders Ephemeroptera, Plecoptera and Trichoptera, or to factors such as the physico-chemical features of the water, or sampling methods. Six streams were sampled quantitatively, of which three streams (Abbifalls, Monkey falls and Silver Cascade) were within protected areas and the remaining three streams (Kumbakarai, Shenbagadevi and Manimutharu falls) were in unprotected areas. A total of 3,209 individual aquatic insects belonging to 25 genera, 18 families and 7 orders were collected. The highest species richness and abundance was observed in Monkey falls followed by Kumbakkarai falls. Large numbers of more habitat-sensitive organisms such as Ecdyonurus sp., Epeorus sp., Thalerosphyrus sp., Euthraulus sp., and Nathanella sp., were found in Monkey falls. Though the species assemblage was somewhat different, pollution-sensitive taxa were also observed in Kumbakkarai falls. Shenbagadevi and Manimutharu falls had a lower diversity of aquatic insects. The likely causes of these differences are discussed.

Infectivity analysis of two variable DNA B components of Mungbean yellow mosaic virus-Vigna in Vigna mungo and Vigna radiata

Mungbean yellow mosaic virus-Vigna (MYMV-Vig), a Begomovirus that causes yellow mosaic disease, was cloned from field-infected blackgram (Vigna mungo). One DNA A clone (KA30) and five different DNA B clones (KA21, KA22, KA27, KA28 and KA34) were obtained. The sequence identity in the 150-nt common region (CR) between DNA A and DNA B was highest (95%) for KA22 DNA B and lowest (85.6%) for KA27 DNA B. The Rep-binding domain had three complete 11-nt (5'-TGTATCGGTGT-3') iterons in KA22 DNA B (and KA21, KA28 and KA34), while the first iteron in KA27 DNA B (5'-ATCGGTGT-3') had a 3-nt deletion. KA27 DNA B, which exhibited 93.9% CR sequence identity to the mungbean-infecting MYMV, also shared the 3-nt deletion in the first iteron besides having an 18-nt insertion between the third iteron and the conserved nonanucleotide. MYMV was found to be closely related to KA27 DNA B in amino acid sequence identity of BV1 (94.1%) and BC1 (97.6%) proteins and in the organization of nuclear localization signal (NLS), nuclear export signal (NES) and phosphorylation sites. Agroinoculation of blackgram (V. mungo) and mungbean (V. radiata) with partial dimers of KA27 and KA22 DNA Bs along with DNA A caused distinctly different symptoms. KA22 DNA B caused more intense yellow mosaic symptoms with high viral DNA titre in blackgram. In contrast, KA27 DNA B caused more intense yellow mosaic symptoms with high viral DNA titre in mungbean. Thus, DNA B of MYMVVig is an important determinant of host-range between V. mungo and V. radiata.

Sequence analysis of infectious bursal disease virus isolates from India: phylogenetic relationships

Prevalence of infectious bursal disease (IBD) among chickens in different parts of Tamil Nadu, India, has been studied by collection of bursal samples from suspected flocks and by performing reverse transcription-polymerase chain reaction (RT-PCR) for amplification of a specific product of 474 bp from the variable region of the VP2 gene. Among 53 bursal samples examined by RT-PCR, 40 showed a positive reaction. The amplified products were subjected to nucleotide sequencing and the obtained sequences were compared with those of IBD virus (IBDV) vaccine strain Georgia, the classical virulent strain 52/70 and the very virulent Japanese OKYM strain. Nucleotide homology data indicated that all the Tamil Nadu isolates showed homology ranging from 91 to 99.6% among themselves. When compared with the very virulent Japanese OKYM strain, four isolates grouped with that strain. Majority of the isolates clustered with the very the virulent OKYM strain as evident from phylogenetic analysis performed using the MEGA program. Comparison of the deduced amino acid sequences of IBDV isolates with those of the vaccine strain Georgia, the classical virulent strain 52/70 and the very virulent strain OKYM also revealed the presence of conserved serine-rich heptapeptide sequence in most of the isolates. Results of this study indicate that majority of the IBDV isolates are very virulent, which is evident from heavy mortality that has been reported in few flocks of poultry in spite of regular vaccination.

Automatic leukocyte classification using cytochemically stained smears

A leukocyte classification algorithm suitable for automated differential counting has been developed for blood smears stained with a new three-component cytochemical stain which has relatively narrow absorption bands centered at 460, 540 and 640 nm, respectively. The classification procedure is the result of a pattern recognition experiment using a sample of 223 leukocytes distributed evenly over the five normal cell types. The basic data for each cell were three digital microscopic images obtained with narrow band illumination at the above central wavelengths using a TV-digitizer system interfaced to a PDP-15 computer. The classification algorithm involves a sequential decision procedure utilizing five pattern features computed from the intensity histograms of the green and blue digital images. Thus the number of arithmetic operations and the number of computer memory words necessary to perform the classification into one of the five normal white blood cell types are both proportional to n where n is the number of gray levels into which the intensity scale is divided. In this experiment, n equals 256. Comparison of our results with work of others on smears prepared with Romanowski-type stains indicates that such narrow-band, spectrally well separated cytochemical multiple stains can permit the use of algorithms which are approximately ten times faster.