PGPR: the treasure of multifarious beneficial microorganisms for nutrient mobilization, pest biocontrol and plant growth promotion in field crops.

Plant growth-promoting rhizobacteria (PGPR) have multifarious beneficial activities for plant growth promotion; act as source of metabolites, enzymes, nutrient mobilization, biological control of pests, induction of disease resistance vis-a-vis bioremediation potentials by phytoextraction and detoxification of heavy metals, pollutants and pesticides. Agrochemicals and synthetic pesticides are currently being utilized widely in all major field crops, thereby adversely affecting human and animal health, and posing serious threats to the environments. Beneficial microorganisms like PGPR could potentially substitute and supplement the toxic chemicals and pesticides with promising application in organic farming leading to sustainable agriculture practices and bioremediation of heavy metal contaminated sites. Among field crops limited bio-formulations have been prepared till now by utilization of PGPR strains having plant growth promotion, metabolites, enzymes, nutrient mobilization and biocontrol activities. The present review contributes comprehensive description of PGPR applications in field crops including commercial, oilseeds, leguminous and cereal crops to further extend the utilization of these potent groups of beneficial microorganisms so that even higher level of crop productivity and quality produce of field crops could be achieved. PGPR and bacteria based commercialized bio-formulations available worldwide for its application in the field crops have been compiled in this review which can be a substitute for the harmful synthetic chemicals. The current knowledge gap and potential target areas for future research have also been projected.

Development of loop mediated isothermal amplification (LAMP): A new tool for rapid diagnosis of cotton leaf curl viral disease.

Cotton leaf curl disease (CLCuD) ranks top among all endemic diseases transmitted by whitefly (Bemisia tabaci) affecting cotton (Gossypium hirsutum) causing severe economic losses to the cotton growers in the Indian subcontinent. For its effective management, robust tools for detection are a prerequisite and it is important to diagnose the virus titre in early stage of infection in plants as well as in the disease transmitting vector. Considering the limitations in current PCR-based techniques we have standardised rapid and sensitive Loop Mediated Isothermal Amplification (LAMP) protocol for the diagnosis of cotton leaf curl virus (CLCuV) in cotton leaves and in its transmitting vector whitefly. Perhaps, this is the first report of use of LAMP tool for rapid diagnosis of CLCuV in cotton and its transmitting vector the whitefly. Further, the colorimetric detection for diagnostic simplicity of amplified LAMP product by using different dyes lead to enhanced applicability of this technique in the field of disease diagnostics. The merit of present study is that the diagnostic failure of PCR and LAMP due to low virus titre in the infected leaf has been circumvented through the combination of rolling circle amplification (RCA) with LAMP. Thus RCA-LAMP can be an option for ultra-sensitive detection of samples with low virus titre. The potential applications of this advanced diagnostic tool in laboratory research on diagnosis of CLCuV, an important viral pathogen of cotton have been discussed.

Genome-wide identification and expression analysis of the plant specific LIM genes in Gossypium arboreum under phytohormone, salt and pathogen stress.

Asiatic cotton (Gossypium arboreum) cultivated as 'desi cotton' in India, is renowned for its climate resilience and robustness against biotic and abiotic stresses. The genome of G. arboreum is therefore, considered as a valued reserve of information for discovering novel genes or gene functions for trait improvements in the present context of cotton cultivation world-wide. In the present study, we carried out genome-wide analysis of LIM gene family in desi cotton and identified twenty LIM domain proteins (GaLIMs) which include sixteen animals CRP-like GaLIMs and four plant specific GaLIMs with presence (GaDA1) or absence (GaDAR) of UIM (Ubiquitin Interacting Motifs). Among the sixteen CRP-like GaLIMs, eleven had two conventional LIM domains while, five had single LIM domain which was not reported in LIM gene family of the plant species studied, except in Brassica rapa. Phylogenetic analysis of these twenty GaLIM proteins in comparison with LIMs of Arabidopsis, chickpea and poplar categorized them into distinct αLIM1, ßLIM1, γLIM2, δLIM2 groups in CRP-like LIMs, and GaDA1 and GaDAR in plant specific LIMs group. Domain analysis had revealed consensus [(C-X2-C-X17-H-X2-C)-X2-(C-X2-C-X17-C-X2-H)] and [(C-X2-C-X17-H-X2-C)-X2-(C-X4-C-X15-C-X2-H)] being conserved as first and/or second LIM domains of animal CRP-like GaLIMs, respectively. Interestingly, single LIM domain containing GaLIM15 was found to contain unique consensus with longer inter-zinc-motif spacer but shorter second zinc finger motif. All twenty GaLIMs showed variable spatio-temporal expression patterns and accordingly further categorized into distinct groups of αLIM1, ßLIM1, γLIM2 δLIM2 and plant specific LIM (DA1/DAR). For the first time, response of GaDA1/DAR under the influence of biotic and abiotic stresses were studied in cotton, involving treatments with phytohormones (Jasmonic acid and Abscisic acid), salt (NaCl) and wilt causing pathogen (Fusarium oxysporum). Expressions patterns of GaDA1/DAR showed variable response and identified GaDA2 as a probable candidate gene for stress tolerance in G. arboreum.

Heteroplasmy due to coexistence of mtCOI haplotypes from different lineages of the Thrips tabaci cryptic species group.

Heteroplasmy is the existence of multiple mitochondrial DNA haplotypes within the cell. Although the number of reports of heteroplasmy is increasing for arthropods, the occurrence, number of variants, and origins are not well studied. In this research, the occurrence of heteroplasmy was investigated in Thrips tabaci, a putative species complex whose lineages can be distinguished by their mitochondrial DNA haplotypes. The results from this study showed that heteroplasmy was due to the occurrence of mitochondrial cytochrome oxydase I (mtCOI) haplotypes from two different T. tabaci lineages. An assay using flow cytometry and quantitative real-time PCR was then used to quantify the per cell copy number of the two mtCOI haplotypes present in individuals exhibiting heteroplasmy from nine geographically distant populations in India. All of the T. tabaci individuals in this study were found to exhibit heteroplasmy, and in every individual the per cell copy number of mtCOI from lineage 3 comprised 75-98% of the haplotypes detected and was variable among individuals tested. There was no evidence to suggest that the presense of lineage-specific haplotypes was due to nuclear introgression; however, further studies are needed to investigate nuclear introgression and paternal leakage during rare interbreeding between individuals from lineages 2 and 3.

Do Panic Symptoms Affect the Quality of Life and Add to the Disability in Patients with Bronchial Asthma?

Background. Anxiety and panic are known to be associated with bronchial asthma with variety of impact on clinical presentation, treatment outcome, comorbidities, quality of life, and functional disability in patients with asthma. This study aims to explore the pattern of panic symptoms, prevalence and severity of panic disorder (PD), quality of life, and disability in them. Methods. Sixty consecutive patients of bronchial asthma were interviewed using semistructured proforma, Panic and Agoraphobia scale, WHO Quality of life (QOL) BREF scale, and WHO disability schedule II (WHODAS II). Results. Though 60% of the participants had panic symptoms, only 46.7% had diagnosable panic attacks according to DSM IV TR diagnostic criteria and 33.3% had PD. Most common symptoms were "sensations of shortness of breath or smothering," "feeling of choking," and "fear of dying" found in 83.3% of the participants. 73.3% of the participants had poor quality of life which was most impaired in physical and environmental domains. 55% of the participants had disability score more than a mean (18.1). Conclusion. One-third of the participants had panic disorder with significant effect on physical and environmental domains of quality of life. Patients with more severe PD and bronchial asthma had more disability.

Sequence analysis of Indian iris yellow spot virus ambisense genome segments: evidence of interspecies RNA recombination.

The nucleotide sequence of M- and S-RNA segments of an Indian iris yellow spot virus (IYSV) were determined. Sequence comparisons showed that both of these sequences shared less than 95 % identity with those other known IYSV isolates. Phylogenetic analysis revealed that the S- and M-RNA sequences of known IYSV isolates clustered with those of the tospoviruses, tomato yellow ring virus, polygonum ringspot virus and hippeastrum chlorotic ringspot virus. Further, multiple recombination detection methods detected inter- and intra-species recombination events that clustered primarily within the intergenic regions of S- and M-RNA, suggesting that these are possibly recombination hotspots in IYSV and closely related tospoviruses.

Clinical and epidemiological study of EGFR mutations and EML4-ALK fusion genes among Indian patients with adenocarcinoma of the lung.

BACKGROUND: Mutation in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) is a common feature observed in lung adenocarcinoma. A fusion gene between echinoderm microtubule-associated protein-like 4 (EML4) and the intracellular domain of anaplastic lymphoma kinase (ALK), named EML4-ALK, has been identified in a subset of non-small-cell lung cancer (NSCLC) tumors. The objective of this study was to determine the prevalence of EGFR mutations and EML4-ALK fusions in Indian patients with NSCLC (adenocarcinoma) as well as evaluate their clinical characteristics. PATIENTS AND METHODS: Patients with NSCLC, adenocarcinoma histology, whose tumors had been tested for EGFR mutational status, were considered for this study. ALK gene rearrangement was detected by fluorescence in situ hybridization using the Vysis ALK Break Apart Rearrangement Probe Kit. ALK mutation was tested in samples that were negative for EGFR mutation. RESULTS: A total of 500 NSCLC adenocarcinoma patients were enrolled across six centers. There were 337 (67.4%) men and 163 (32.6%) women with a median age of 58 years. One hundred and sixty-four (32.8%) blocks were positive for EGFR mutations, whereas 336 (67.2%) were EGFR wild-type. Of the 336 EGFR-negative blocks, EML4-ALK fusion gene was present in 15 (4.5%) patients, whereas 321 (95.5%) tumors were EML4-ALK negative. The overall incidence of EML4-ALK fusion gene was 3% (15/500). CONCLUSION: The incidence of EGFR mutations (33%) in this Indian population is close to the reported incidence in Asian patients. EML4-ALK gene fusions are present in lung adenocarcinomas from Indian patients, and the 3% incidence of EML4-ALK gene fusion in EGFR mutation-negative cases is similar to what has been observed in other Western and Asian populations. The mutual exclusivity of EML4-ALK and EGFR mutations suggests implementation of biomarker testing for tumors harboring ALK rearrangements in order to identify patients that can benefit from newer targeted therapies.

Shared or induced obsessive compulsive disorder: Is it a reality?

BACKGROUND: Shared or induced obsessive compulsive disorder (OCD) is not yet a distinct diagnosis in classification of psychiatric disorders. In fact, though recognized as a diagnostic category, shared or induced psychotic disorders are rare and most of the literature is based on the case reports. MATERIALS AND METHODS: We are reporting three case studies manifested with shared or induced OCD (cases with obsessive symptoms that were shared from the primary case in their family). RESULTS: All the cases were treated considering shared or induced OCD as psychopathology. Response to treatment modalities in first and second case and poor response to treatment in third case is suggestive of shared or induced OCD as a distinct entity. It is different from shared psychosis in many ways. CONCLUSION: Shared or induced OCD is a distinct diagnosis. Greater awareness about this entity among mental health professionals is needed.

First Report of Iris yellow spot virus Infecting Allium tuberosum in India.

Allium tuberosum L., commonly known as garlic chives, is an important spice in northeastern India as well as in many other parts of the world. Iris yellow spot virus (IYSV; genus Tospovirus, family Bunyaviridae) is an important pathogen of onion (4) and other related Alliums such as garlic (3) and leek (2). During April 2013, symptoms potentially induced by IYSV such as chlorotic and straw-colored spindle-like lesions were observed on leaves of A. tuberosum accession Hanzong Winter (CGN 20779) plants in the wild species garden at the Directorate of Onion and Garlic Research (DOGR), Rajgurunagar, Pune, Maharashtra, India. Ten plant samples of A. tuberosum were randomly collected from the wild species garden and the upper, middle, and lower portions of the leaves were pooled and tested by double-antibody sandwich (DAS)-ELISA using a commercially available kit (Agdia Inc., Elkhart, IN) for IYSV. All of them showed positive results for IYSV incidence. Total RNA from the ELISA positive leaf samples of A. tuberosum was extracted using the RNeasy Plant Mini kit (Qiagen GmbH, Hilden, Germany). The primer pair IYSV-F (5'-TCAGAAATCGAGAAACTT-3') and IYSV-R (5'-TAATTATATCTATCTTTCTTGG-3') (1) was used for RT-PCR. The primer pair was specific to amplify 797 bp of the nucleocapsid (N) gene of IYSV. The amplified product derived from A. tuberosum isolate was purified by QIAquick PCR Purification Kit (Qiagen) and cloned using the vector pDrive (Qiagen). The recombinant clone was sequenced (Accession No. KF624624). Sequence analysis performed on CLC Main Workbench Version 6.8.4 confirmed that the fragment was of IYSV. Nucleotide sequence comparison of our virus with other IYSV isolates revealed that the highest nucleotide identity (99%) was with the IYSV garlic isolate (HM173691) from India. Further, maximum 96% protein identity was with IYSV onion isolate (ACA09432) and garlic isolate (ADK56108) from India. To our knowledge, this is the first report of IYSV naturally occurring on A. tuberosum in India. It is evident from previous studies that IYSV causes significant losses in onions (1) and from this study, that its symptoms have direct impact on quality of garlic chives. Further detailed studies are required to assess the magnitude of the impact of IYSV infection on yield and quality of A. tuberosum. References: (1) A. Bulajic et al. Plant Dis. 93:976, 2009. (2) M. C. Córdoba-Sellés et al. Plant Dis. 91:1365, 2007. (3) S. J. Gawande et al. Plant Dis. 94:1066, 2010. (4) B. Mandal et al. Plant Dis. 96:468, 2012.

First Report of Leek yellow stripe virus in Allium sativum in Western India.

Garlic (Allium sativum L.) is an important bulbous spice crop in India as well as other parts of world. Garlic is well known for its medicinal properties. Degeneration due to viral infections is one of the important constraints in exploiting its yield potential. Leek yellow stripe virus (LYSV), genus Potyvirus, family Potyviridae, is a prominent virus known to infect garlic worldwide (4). During July 2013, potyvirus-like symptoms such as mosaic, streaking, stunting, mottling of leaves were observed on garlic cv. G-41 and landrace Ranibennur local, collected from Karnataka, India, and maintained at the Directorate of Onion and Garlic Research, Rajgurunagar, Pune, India. The incidence of symptomatic plants was estimated at 70% for Ranibennur local and 68% for cv. G-41. The symptomatic leaves were sampled diagonally from the field. Twenty symptomatic plants per cultivar with each sample was composited from young, middle, and lower (basal) leaves of the plant. These samples were tested by double-antibody sandwich (DAS)-ELISA for LYSV using commercially available kit (Agdia Inc., Elkhart, IN). ELISA-positive plants were further subjected to molecular studies. Total RNA from the infected leaf samples were extracted by RNeasy Plant Mini kit (Qiagen GmbH, Hilden, Germany) and assayed by reverse transcription (RT)-PCR using primer pair LYSV-F 2 (5'-GCACCATACAGTGAATTGAG-3') (1), LYSV-R (5'-GCCTCGCGCGCTCTAA-3') (3) to amplify 874 bases of partial Nib and partial coat protein gene. The amplified product of 874 bp derived from A. sativum isolate was purified (QIAquick PCR Purification Kit, Qiagen) and cloned using vector pDrive (Qiagen). The recombinant clones were sequenced and submitted in NCBI database (GenBank Accession No. KF850539). The sequence analysis performed on CLC Main Workbench Version 6.8.4 gave confirmation of LYSV. Further, phylogenetic analysis of the 874-nt sequence revealed the highest nucleotide identity (80 to 82%) with LYSV isolates (DQ925453, JN127339, AB005611, and JX429965). To the best of our knowledge, this is the first report of natural infection of garlic by LYSV in western India. LYSV is known to cause direct losses in garlic and other related Allium spp. Up to 54% reduction in bulb weight was observed due to single infection of this virus (2). Hence, our first report about this virus has significant impact on garlic production scenario, if this virus found to be widespread in the country. For this, additional surveys and genotype screenings are needed to obtain a better understanding of the potential impact of LYSV on garlic production in India. References: (1) H. Fidan and S. Baloglu. Plant Dis. 93:672, 2009. (2) H. Lot et al. Plant Dis. 82:1381, 1998. (3) P. Lunello et al. J. Virol. Methods. 118:15, 2004. (4) H. R. Pappu et al. Plant Dis. 89:205, 2005.

A window of opportunity phase II study of enzastaurin in chemonaive patients with asymptomatic metastatic colorectal cancer.

BACKGROUND: Preclinically, protein kinase C and AKT activation can be inhibited by enzastaurin and reduce tumor growth of colorectal cancer cells. In asymptomatic patients with metastatic colorectal cancer (mCRC), enzastaurin activity was evaluated by measuring the 6-month progression-free survival (PFS) rate in a window study design. PATIENTS AND METHODS: Chemonaive patients with asymptomatic mCRC who did not require immediate chemotherapy-induced tumor reduction received a 400-mg thrice daily loading dose of enzastaurin on day 1 of cycle 1, followed by 500 mg once daily for the remaining 28-day cycles. Progression was assessed on the basis of radiographic imaging, rise in carcinoembryonic antigen or lactate dehydrogenase (LDH) levels or by appearance of clinical symptoms. RESULTS: Twenty-eight patients received daily enzastaurin. The 6-month PFS rate was 28% [95% confidence interval (CI) 13%-45%] and median PFS was 1.9 months (95% CI 1.8-4.5 months). Twelve (43%) patients had stable disease with a median duration of 6.1 months. The survival rate at 20 months was 77% (95% CI 47%-92%). No grade 4 toxicity was reported and grade 3 toxic effects were observed in three patients with one patient showing probable drug-related elevation of liver transaminases. CONCLUSION: The window design in asymptomatic patients with mCRC can be safely applied to assess the activity and safety of novel cytostatic agents like enzastaurin.

First Report of Iris yellow spot virus on Garlic in India.

Garlic (Allium sativum) is a spice crop of prime importance in India as well as other parts of the world. Iris yellow spot virus (IYSV; genus Tospovirus, family Bunyaviridae) is an important pathogen of onion bulb and seed crops in many parts of the world (3). The virus is also known to infect garlic and other Allium spp. (2-4). IYSV infection of garlic was reported from Reunion Island (4) and the United States (1). In February 2010, straw-colored, spindle-shaped spots with poorly defined ends were observed on the leaves of a garlic crop at the research farm of the Directorate of Onion and Garlic Research in the Pune District of Maharashtra State, India, 105 days after planting. The spots coalesced to form larger patches on the leaves, suggesting possible IYSV infection. Symptoms were visible on older leaves and more prevalent on cv. G-41, G-282, AC50, AC200, AC283, and Godavari than on other cultivars. The incidence of symptomatic plants was estimated at 5% for G-41 and AC-200, 8% for G-282 and AC283, and 10% for AC50. Leaves were sampled from 40 symptomatic plants per cultivar with each sample composited from young, middle, and older (basal) leaves of the plant. Samples were assayed by double-antibody sandwich-ELISA (Loewe Biochemica GmbH, Sauerlach, Germany) and each tested positive for the virus. Total RNA was extracted from the leaves of ELISA-positive plants using the RNAeasy Plant Mini kit (Qiagen GmbH, Hilden, Germany) and tested by reverse transcription-PCR assay using primers IYSV-F (5'-TCAGAAATCGAGAAACTT-3') and IYSV-R (5'-TAATTATATCTATCTTTCTTGG-3') (2) designed to amplify 797 bp of the nucleocapsid (N) gene of IYSV. Amplicons of expected size were obtained and cloned into a pDrive vector (Qiagen GmbH). The recombinant clone was sequenced (GenBank Accession No. HM173691). Sequence comparisons showed 98 to 100% nt identity with other IYSV N gene sequences in GenBank (Nos. EU310294 and EU310286). A phylogenetic analysis of the deduced amino acid sequences of the N gene showed that the garlic isolate of IYSV grouped most closely with onion IYSV isolates from India (GenBank Nos. EU310294, EU310286, EU310300, and EU310296). To our knowledge, this is the first report of natural infection of garlic by IYSV in India. Additional surveys and evaluations are needed to obtain a better understanding of the potential impact of IYSV on garlic production in India. References: (1) S. Bag et al. Plant Dis. 93:839, 2009. (2) A. Bulajic et al. Plant Dis. 93:976, 2009. (3) D. Gent et al. Plant Dis. 90:1468, 2006. (4) I. Robène-Soustrade et al. Plant Pathol. 55:288, 2006.

Optimized sequence of drug administration and schedule leads to improved dose delivery for gemcitabine and paclitaxel in combination: a phase I trial in patients with recurrent ovarian cancer.

We examined appropriate sequence, schedule, and doses of gemcitabine (G) and paclitaxel (T) in patients with persistent or recurrent epithelial ovarian cancer. Patients received a maximum of six cycles of gemcitabine on days 1 and 8 (starting 1000 mg/m(2)), and paclitaxel (starting 135 mg/m(2)) on day 8 (groups A and B) or day 1 (group C). Drug sequences (G-->T and T-->G) were tested in group A. In group A, changing sequences of gemcitabine and paclitaxel infusion were evaluated. Sequence G-->T raised grade 3 alanine transaminase in two of three patients leading to use of T-->G sequence for remainder of study. In group B, maximum tolerable dose was reached at gemcitabine 1000 mg/m(2) and paclitaxel 175 mg/m(2). Reducing paclitaxel to 150 mg/m(2) allowed escalation of gemcitabine to 1250 mg/m(2), but neutropenia-related treatment delays occurred. Giving paclitaxel on day 1 (group C) enabled administration of paclitaxel 175 mg/m(2) and gemcitabine 1250 mg/m(2) with minimal dose adjustments. The overall response rate was 41.0%, with 2 complete responses and 14 partial responses in 39 eligible patients. The schedule of paclitaxel 175 mg/m(2) (day 1) and gemcitabine 1250 mg/m(2) (days 1 and 8), with sequence of T-->G, appears most suitable with tolerable toxicity and promising activity.

Patient-reported health status in total joint replacement.

A total of 176 consecutive patients undergoing either total hip or total knee arthroplasty were given SF-36 surveys at 4 time intervals: preoperatively and at 3 months, 6 months, and 1 year postoperatively. Transformed SF-36 scores were compared at the preoperative and 1-year time intervals between several demographic variables, including age, gender, number of sides replaced (unilateral vs bilateral procedure), and type of joint replacement surgery (knee or hip). Joint replacement surgery seemed to correct various self-reported health status differences that appeared preoperatively in demographic groups.

Comparison of patient satisfaction results during a period of rapid growth for a specialty group practice.

Orthopaedics Indianapolis is a private specialty group practice that experienced a phase of rapid growth between 1993 and 1996. During this period, the group doubled in size from 18 to 36 physicians without a corresponding increase in support personnel. To maintain the quality of clinical services during and after this rapid expansion, a number of quality improvement efforts were initiated. The 9-item Visit Rating Questionnaire (VRQ) was used four times over this 3-year period to evaluate patients' satisfaction with their visit to our clinic. We found that there was significant improvement during this time in several patient satisfaction constructs, including overall satisfaction, in spite of considerable increase in clinic volume. This paper presents the results of our VRQ surveys and outlines the various methods used to make clinical services more efficient. Having quality improvement efforts lead changes in group practice operations can make a significant impact on satisfaction, even during a period of rapid growth and change.

Effect of anesthetic variables on dermatomal somatosensory-evoked potential monitoring in elective lumbar spinal surgery.

We studied 108 adult cases of elective lumbar surgery using dermatomal somatosensory-evoked potential (DSEP) monitoring to evaluate its usefulness due to concern over potential neurologic injury during pedicle screw insertion. Both surgeons used all of the necessary precautions required during surgery so that DSEP monitoring was not the "primary," but rather a backup system for operative security. Quality tracings were obtained in 71% of cases; anesthetic difficulties being the major cause of poor monitoring. There were no neurological complications related to pedicle screw insertion. We found that DSEP monitoring was an excellent method to verify intraoperative neurological status, but required a high degree of cooperation between the anesthesiologists, monitoring technician, and surgeons. In today's cost-containment environment, its usefulness is subjected to the expertise of the spine surgeon and the hospital setting.

Characterization of bone-derived chondrogenesis-stimulating activity on embryonic limb mesenchymal cells in vitro.

Demineralized bone matrix contains factors which stimulate chondrogenesis and osteogenesis in vivo. A water-soluble extract of bone has been shown to stimulate chondrogenesis in vitro in embryonic limb mesenchymal cells (Syftestad, Lucas & Caplan, 1985). The aim of this study was to analyse the cellular mechanism of the bone-derived chondrogenesis-stimulating activity, with particular attention on how normal requirements for chondrogenesis may be altered. The effects of bovine bone extract (BBE) on chondrogenesis in vitro were studied using micromass cultures of chick limb bud mesenchyme isolated from embryos at Hamburger-Hamilton (HH) stage 23/24, an experimental system which is capable of undergoing chondrogenic differentiation. Bovine diaphyseal long bones were demineralized and extracted with guanidine-HCl to prepare BBE (Syftestad & Caplan, 1984). High-density mesenchyme cultures (30 x 10(6) cells/ml) were exposed to different doses of BBE (0.01-1.0 mg ml-1) and chondrogenesis was quantified based on cartilage nodule number and [35S]sulphate incorporation. BBE was tested on micromass cultures of varying plating densities (2-30 x 10(6) cells/ml), on cultures of 'young' limb bud cells (HH stage 17/18), and on cultures enriched with chondroprogenitor cells obtained from subridge mesoderm. Since poly-L-lysine (PL) has recently been shown (San Antonio & Tuan, 1986) to promote chondrogensis, PL and BBE were introduced together in different doses, in the culture medium, to determine if their actions were synergistic. Our results show that BBE stimulates chondrogenesis in a dose-dependent manner and by a specific, direct action on the chondroprogenitor cells but not in normally non-chondrogenic, low density or 'young' limb bud cell cultures. The effects of PL and BBE are additive and these agents appear to act by separate mechanisms to stimulate chondrogenesis; PL primarily enhances nodule formation, and BBE appears to promote nodule growth.

Ultrastructural localization of 5'nucleotidase in human normal and malignant lymphoid cells.

5'Nucleotidase (EC 3.1.3.5), a purine pathway enzyme, occurs as a cellular ectoenzyme. Widely differing 5'N activity has been reported in different types of lymphoid cells and appears to be related to lymphocyte function, differentiation and immunological subtype. This paper reports a study on the ultrastructural distribution of 5'N in in different types of lymphoid leukemias and non-Hodgkin's lymphomas. In lymphoid leukemias, only cALL cells showed strong 5'N staining. In CLL, PLL and HCL the intensity of staining was less than in normal cells. In the NHL group, the reaction pattern was mixed. Infiltrating neoplastic cells, specially the large lymphoid cells, consistently showed very mild activity of the enzyme, whereas follicular center cells and other mature lymphocytes were characterized by moderately strong to strong 5'N activity. These results support the view that 5'N is a marker of lymphocyte cell differentiation.