Toxicity Evaluation, Plant Growth Promotion, and Anti-fungal Activity of Endophytic Bacteria-Mediated Silver Nanoparticles.

In recent years, the uses of silver nanoparticles have increased, which lead to nanoparticles discharge into aquatic bodies which may, if not well controlled, have harmful effect on different organisms. This calls for the need to constantly evaluate the toxicity level of nanoparticles. In this study, green biosynthesized silver nanoparticles mediated by endophytic bacteria Cronobacter sakazakii (CS-AgNPs) were subjected to toxicity evaluation by brine shrimp lethality assay. The ability of CS-AgNPs to improve plant growth by nanopriming of Vigna radiata L seeds treated with different concentrations (1ppm, 2.5ppm, 5ppm and 10ppm) in order to enhance biochemical constituents was investigated, also its inhibitory effect to growth of phytopathogenic fungi Mucor racemose was examined. Results showed that Artemia salina treated with CS-AgNPs exhibited good hatching percentage and LC50 value of 688.41 µg/ml when Artemia salina eggs were exposed to CS-AgNPs during hatching. Plant growth was enhanced at 2.5ppm CS-AgNPs, with increased photosynthetic pigments, protein, and carbohydrate content. This study suggests that silver nanoparticles synthesized via endophytic bacteria Cronobacter sakazakii are safe to use and can be utilized as means of combating plant fungal pathogens.

Effect of the immediate precursors of phenylalanine and tyrosine on growth and protein synthesis in phenylalanine- and tyrosine-deprived HeLa cells.

Although Phe is an essential amino acid in mammalian cells, its immediate precursor, beta-phenylpyruvic acid (BPP), when present in Phe-deficient medium at 10(-4) and 10(-3) M is converted at a sufficient rate to Phe to sustain growth at 60 and 100% of non-deficient control HeLa S-3 cells, respectively. In contrast, Tyr-deficient cells were unable to convert the immediate precursor of Tyr, OH-beta-phenylpyruvic acid (OHBPP), nor could BPP rescue Tyr-deficient cells. The results are considered in terms of the organization of intracellular pathways by which precursors are transaminated and made available for protein synthesis.

Chirality differences in amino acid retention and release from acid-extractable pool of cultured mammalian cells.

In previous work, no chiral differences were found between D and L enantiomers of Leu in their ability to displace one another from the acid-extractable pool in mammalian cells. Recent evidence suggested otherwise. Our aim is to examine whether, in physiological range, D-amino acids have an equivalent ability to displace L-amino acids from the acid-extractable pool of HeLa cells, and vice versa. In the Millimolar range, D-Leu and L-Leu have similar uptake and displacement properties with regard to the acid-extractable pool in HeLa cells, despite only the latter isomer being incorporated into protein. Below millimolar concentration however, a distinct difference was found in the displacement of tritium-labelled L-Leu from the pool by unlabelled D-Leu compared with unlabelled L-Leu. Thus, unlabelled L-Leu in the external medium at 10(-4) or 10(-5) M displaced and equivalent amount of label from the pool ad D-Leu introduced at a concentration approx. one order of magnitude higher, respectively. Reciprocal experiments, in which the acid-extractable pool was preloaded with 3H-D-Leu, confirmed this finding. The chirality difference was noted whether pool prelabelling was carried out at 37 or 0 degrees C; but in order to avoid the complications of active transport mechanisms, the competition work reported here was done at 0 degrees C. Similar chirality differences were observed with other hydrophobic amino acids, including His, Ile, and Phe, such as, preferential displacement by the L-Leu racemer compared with the D-Leu racemer below mM levels. This was also true for the D and L forms of the non-utilisable isomer of Leu, norleucine (nLeu). We conclude that D-forms of hydrophobic amino acids have lower affinity for similar or the same intracellular binding sites involved in the acid-extractable pool than in their L-forms. The significance of these findings to amino acid pools in cells, and to the predominance of L-forms of amino acids in the biosphere is considered

Massive right atrial thrombus associated with a Chiari network and a Hickman catheter.

The Chiari network is an embryologic remnant that is said to be present in only 1.5-3% of adults. It is rarely of clinical importance but may, very infrequently, be the site of thrombosis. The authors describe a patient in whom a massive right atrial thrombus formed on a Chiari network, leading to intermittent tricuspid obstruction. The thrombus had formed after the use of a Hickman catheter for the administration of cytotoxic chemotherapy. They can find no previously recorded examples of sufficient thrombus forming on a Chiari network to threaten life by obstructing the flow of blood through the heart.

Red cell hypoplasia, thrombocytosis, and leucocytosis: myelodysplastic and proliferative syndrome.

Three patients with chronic red cell aplasia also showed thrombocytosis or granulocytosis, or both. All had morphological evidence of myelodysplasia on examination of bone marrow aspirate but none had a detectable chromosomal abnormality. These patients seem to provide evidence of a separate entity within the spectrum of myelodysplastic and myeloproliferative disease.

Systemic infection with Aureobasidium pullulans in a leukaemic patient.

Aureobasidium pullulans, a conidial fungus widely distributed in the environment, was repeatedly isolated from the blood of a 28-year-old man with acute myeloid leukaemia. Amphotericin B failed to eliminate the organism.

Hepatitis C-related chronic liver disease among asymptomatic blood donors in the north west of England.

In the first 19 months of screening, the North Western Regional Transfusion Centre (RTC) tested 224,000 consecutive blood donors for antibody to hepatitis C virus (anti-HCV) by second generation enzyme immunoassay (EIA). Of these, 366 repeatedly reactive samples were referred for confirmatory testing at Manchester Public Health Laboratory (PHL). There, the initial EIA was repeated, together with two further EIAs. All the referred samples were subjected to a confirmatory line immunoblot (RIBA-II). Reverse transcription followed by the polymerase chain reaction (RT-PCR), in order to detect viral RNA, was performed on selected samples. Among the donors, 61 accepted offers for medical review and were assessed for risk factors, clinical findings and results of standard liver function tests. Of these donors, 53 proceeded to liver biopsy. The overall prevalence of confirmed positive donors was 0.04%. Main risk factors identified included intravenous drug abuse in 31 (51%) donors and prior blood transfusion in 12 (20%) but a risk factor was not apparent in 11 (18%). Viraemia, detected by RT-PCR, could be predicted with a high degree of accuracy by means of the readily available and simpler screening and confirmatory tests (EIA and RIBA-II). Established chronic hepatitis was demonstrated in 90% of the liver biopsies. A trend towards worsening histological findings accompanied increasing concentrations of serum transaminase. Even so, many donors with normal transaminase values had abnormal biopsies including those showing chronic active hepatitis (CAH). These findings indicate that a substantial proportion of previously unrecognised asymptomatic persons with established chronic liver disease exists among North Western blood donors.(ABSTRACT TRUNCATED AT 250 WORDS)

Serious hazards of transfusion (SHOT) initiative: analysis of the first two annual reports.

OBJECTIVE: To receive and collate reports of death or major complications of transfusion of blood or components. DESIGN: Haematologists were invited confidentially to report deaths and major complications after blood transfusion during October 1996 to September 1998. SETTING: Hospitals in United Kingdom and Ireland. SUBJECTS: Patients who died or experienced serious complications, as defined below, associated with transfusion of red cells, platelets, fresh frozen plasma, or cryoprecipitate. MAIN OUTCOME MEASURES: Death, "wrong" blood transfused to patient, acute and delayed transfusion reactions, transfusion related acute lung injury, transfusion associated graft versus host disease, post-transfusion purpura, and infection transmitted by transfusion. Circumstances relating to these cases and relative frequency of complications. RESULTS: Over 24 months, 366 cases were reported, of which 191 (52%) were "wrong blood to patient" episodes. Analysis of these revealed multiple errors of identification, often beginning when blood was collected from the blood bank. There were 22 deaths from all causes, including three from ABO incompatibility. There were 12 infections: four bacterial (one fatal), seven viral, and one fatal case of malaria. During the second 12 months, 164/424 hospitals (39%) submitted a "nil to report" return. CONCLUSIONS: Transfusion is now extremely safe, but vigilance is needed to ensure correct identification of blood and patient. Staff education should include awareness of ABO incompatibility and bacterial contamination as causes of life threatening reactions to blood.

Quantification of anti-c in haemolytic disease of the newborn.

Anti-c is an important Rh antibody that causes haemolytic disease of the newborn (HDN). We have carried out a retrospective analysis of the clinical outcome of pregnancy in 120 mothers with anti-c. Of these, 100 gave birth to c-positive infants, of whom 14 had severe HDN requiring exchange transfusion. In all of these, the maternal level was 9.5 iu/ml or greater. Of the 29 women with anti-c levels of 9.5 iu/ml or above, in addition to the 14 with severely affected infants, 15 had infants requiring only phototherapy or no treatment. Our observations suggest that when the anti-c level is below 7.5 iu/ml, the fetus is unlikely to be seriously affected and invasive obstetric intervention is unnecessary. Of the 120 women studied, 50% had had a blood transfusion, in most cases for obstetric complications in a previous pregnancy. Although it was not possible to attribute alloimmunization to blood transfusion rather than previous pregnancy in any individual case, this observation points to the value of routine c typing as part of antenatal screening, so that c-negative blood can be selected.

Bone marrow necrosis complicating chronic myeloid leukaemia.

Two women with chronic myeloid leukaemia in chronic phase were found to have bone marrow necrosis when severe bone pains and falling blood counts prompted a marrow examination to exclude blast transformation. One patient survived for 12 months following the event without transforming. The second patient died soon after and was found to have widespread extramedullary disease.

Failure of mithramycin to control the myeloid blast phase of chronic granulocytic leukemia: a report on nine patients and review of the literature.

After reports of the successful use of mithramycin and hydroxyurea in the myeloid blast phase of chronic granulocytic leukemia, we treated nine patients according to the protocol devised by Koller and Miller (1986). There were no complete responses, but one patient had a partial response with a transient return to the chronic phase. Of the remaining eight patients, two experienced lessening of bone pains, and one a reduction in spleen size, but without hematological improvement. The regimen was associated with significant toxicity, and no overall survival advantage. We present a review of published data regarding the use of mithramycin in chronic granulocytic leukemia which supports the results in our series. The combination of mithramycin and hydroxyurea is largely ineffective in the blast phase of chronic granulocytic leukemia, but may be of value in the accelerated phase.

The histopathological features of asymptomatic hepatitis C virus-antibody positive blood donors.

Since the introduction of screening for hepatitis C virus (HCV) in donated blood, the risk of contracting posttransfusion hepatitis has been greatly reduced and the test has led to the recognition of asymptomatic blood donors positive for anti-HCV antibodies. Following confirmation of the HCV status with second generation RIBA testing followed by counselling, 55 patients had full investigations, including liver biopsy. These were classified by the traditional chronic hepatitis system and were graded according to the Knodell and Scheuer histological activity indices. Seven of the biopsies were normal (12%), apart from minor degrees of steatosis in two. Eleven cases (20%) were in the chronic lobular hepatitis category without portal inflammation, while 37 cases showed portal inflammation, including 20 (36%) cases where chronic persistent hepatitis was the predominant feature and 17 cases (31%) where there was chronic active hepatitis with piecemeal necrosis. Features which have previously been described in chronic HCV-associated hepatitis were noted: portal lymphoid aggregates (58%), lymphoid follicles with germinal centres (15%), bile duct damage (11%), lobular inflammation (80%), sinusoidal mononuclear cell infiltration (26%), acidophil body formation (11%), and steatosis (47%). Fibrosis was present in 46% of cases but was generally of mild degree; 9% of biopsies demonstrated bridging fibrosis but no cases of cirrhosis were present. Even though serum transaminase levels correlated well with the presence of chronic hepatitis and with the Scheuer and Knodell activity indices, a proportion of patients with significant liver damage had normal transaminase levels, and this study suggests the need for liver biopsy in the evaluation of asymptomatic HCV-positive blood donors.

Automated screening of blood donations for hepatitis C virus RNA using the Qiagen BioRobot 9604 and the Roche COBAS HCV Amplicor assay.

BACKGROUND AND OBJECTIVES: In order to reduce the potential for transmission of hepatitis C virus (HCV) from an RNA-positive, anti-HCV-negative blood donation, the National Blood Service (NBS) introduced nucleic acid amplification technology (NAT) testing for HCV in England and Wales. The objective of this study was to develop an automated assay using commercial components for the detection of HCV RNA in blood donations for transfusion. MATERIALS AND METHODS: The Qiagen QIAamp 96 'Viral RNA' and 'Virus' BioRobot kits for HCV RNA extraction, and the Roche COBAS HCV Amplicor v2.0 and AmpliScreen v2.0 assays for polymerase chain reaction (PCR) amplification and detection, were investigated. RESULTS: QIAamp technology and the BioRobot 9604 allow automation of the viral RNA extraction process. By combining the automated silica-membrane based QIAamp 96 Virus extraction and automated reverse transcription-polymerase chain reaction (RT-PCR) set-up with COBAS HCV AmpliScreen v2.0 amplification and detection it is possible to achieve a 95% detection level for HCV of 12.8 IU/ml. Cross-contamination studies have shown that use of the BioRobot 9604 does not pose a detectable contamination risk. Between 1999 and 2001, approximately 6.8 x 106 donations were tested in England and Wales, of which only four were found to contain RNA without anti-HCV. CONCLUSIONS: This combination of methods results in an assay with a high sample throughput, little 'hands-on' time and fast turnaround time that is also sufficiently sensitive to allow testing of pools of up to 96 samples at a time. These methods have been successfully introduced into routine use within the NBS for release of blood components with a shelf-life of longer than 24 h.