ABO blood groups as a new potential predictive factor in radiotherapy hematological changes.

AIM: Cancer treatments specially with new high Tec radiotherapy equipment's calling daily progression in method and predictive factors affecting treatment goals. Due to important effect of oxygen on cells radio sensitivity, tumor blood circulation and it's antigens like ABO blood groups maybe an important predictive factor for radiotherapy response and it is adverse events. The aim of this study was the assessment of the hematological manifestations of local radiotherapy and association with ABO blood groups. METHODS: In this observational study, 2 ml of peripheral blood were taken from 152 patients with routine 3D conformal radiotherapy treatment course and the blood parameters achieve and documented at four stage during treatment courses. The data were analyzed by repeated measurement andone-way ANOVA. RESULTS: Statistically significant reductions of the platelets, white blood cells (WBC), and lymphocytes counts were demonstrated. Also an increased percentage of polymorphonuclear cells during local radiotherapy exposure was found. The changes in WBC counts were observed to be in association with ABO blood groups. The other evaluated factors were not significantly associated with ABO blood groups. CONCLUSIONS: Our results showed an association between radiotherapy patients ABO blood groups and some hematological changes in their blood circulation (Fig. 7, Ref. 23).

Test of the Einstein Equivalence Principle near the Galactic Center Supermassive Black Hole.

During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potential to test one part of the Einstein equivalence principle: the local position invariance (LPI). We study the dependency of different atomic transitions on the gravitational potential to give an upper limit on violations of the LPI. This is done by separately measuring the redshift from hydrogen and helium absorption lines in the stellar spectrum during its closest approach to the black hole. For this measurement we use radial velocity data from 2015 to 2018 and combine it with the gravitational potential at the position of S2, which is calculated from the precisely known orbit of S2 around the black hole. This results in a limit on a violation of the LPI of |ß_{He}-ß_{H}|=(2.4±5.1)×10^{-2}. The variation in potential that we probe with this measurement is six magnitudes larger than possible for measurements on Earth, and a factor of 10 larger than in experiments using white dwarfs. We are therefore testing the LPI in a regime where it has not been tested before.

Combination of H120 and 1/96 avian infectious bronchitis virus vaccine strains protect chickens against challenge with IS/1494/06 (variant 2)-like infectious bronchitis virus.

Avian infectious bronchitis (IB) is a worldwide chicken disease, caused by avian infectious bronchitis virus (IBV) which infects all commercial poultry lines. The present study was done to evaluate protection caused by two different serotype vaccines (Massachusetts and 793/B) in order to evaluate protection against challenge with IS/1494/06-like virus (variant 2-like virus), which is prevalent in the Middle East. SPF chickens were divided into four groups (n = 20). First and second group as negative control group and non-vaccinated-challenged group received no vaccine. Groups 3 and 4 received H120-H120 and H120-1/96 IBV vaccine strains at the 1st and 14th day, respectively. Twenty one days after last vaccination, non-vaccinated-challenged group and vaccinated group were challenged using variant 2-like IBV. Serum samples were collected before challenge to measure humoral immune response of chickens. Five days after challenge, the tissue samples from the trachea, lungs and kidneys were taken to evaluate cilliary activity, viral load (quantitative real-time RT-PCR), and histopathological evaluation. Clinical sign scores were also recorded after challenge. Overall, the results showed a protective efficacy of the used vaccination program. Best cross protection (69.2%) was obtained in the H120-1/96 vaccinated group. Virus replication of the challenged virus in H120-1/96 group compared with H120-H120 group showed a significant reduction of viral load in trachea (1.5×103 compared to 503) and kidneys. Clinical sign scores of the challenged groups showed significant effect of the vaccination program to reduce clinical signs. The trachea pathological scores and histopathological findings in the lungs and kidneys also confirmed better protective efficacy of vaccinated groups. In conclusion, using combination of heterologous IBV vaccine serotypes (Massachusetts and 793/B) would be a better strategy to control variant 2-like viruses, but more evaluation is needed using other circulating isolates to find the best combination of vaccines.

Ileal J-Pouch Perforation: Case Report.

A 34-year-old male patient who had undergone total colectomy and J-pouch ileanal anastomosis subsequent to diagnosis of familial adenomatous polyposis five years previously was admitted to the emergency room with complaints of severe abdominal pain of a four-day duration. Physical examination revealed widespread tenderness throughout the abdomen, especially in the lower quadrant. Abdominal ultrasonography revealed fluid between intestinal loops and computed tomography revealed free air and fluid in the abdomen. During laparotomy to expand the ileal J-pouch to approximately 12 cm in diameter, a 2-mm perforation was detected in the blind end of the ileal J-pouch. The perforation was repaired primarily and protective ileostomy was performed. During postoperative endoscopy, neither obstruction nor stasis was observed, but pouchitis was observed in the ileal J-pouch. The patient was postoperatively discharged on the 20th day and followed endoscopically. The endoscopic findings were normal in the sixth month postsurgery.

Delayed capillary breakup of falling viscous jets.

Thin jets of viscous fluid like honey falling from capillary nozzles can attain lengths exceeding 10 m before breaking up into droplets via the Rayleigh-Plateau (surface tension) instability. Using a combination of laboratory experiments and WKB analysis of the growth of shape perturbations on a jet being stretched by gravity, we determine how the jet's intact length l(b) depends on the flow rate Q, the viscosity η, and the surface tension coefficient γ. In the asymptotic limit of a high-viscosity jet, l(b)∼(gQ(2)η(4)/γ(4))(1/3), where g is the gravitational acceleration. The agreement between theory and experiment is good, except for very long jets.

Monitoring and treatment of selected nanoparticles.

With their increasing use, nanoparticles will become concentrated in urban effluents in the future. Both adequate monitoring methods and water treatment technologies will be necessary to assess and avoid consumer exposure. This paper reports results in these two challenging areas for both organic and inorganic nanoparticles. Treatment experiments indicate that lamellar settling is better adapted than dissolved air flotation for SiO(2) nanoparticles removal. The use of 120 mg/L of Aqualenc coagulant without flocculant addition allows 99% removal to be achieved for an initial concentration of 1 g/L. On the other hand, the dissolved air flotation process implemented under the usual industrial conditions does not permit removal of SiO(2) nanoparticles. In this case SiO(2) removal occurs only by settling in the flocculator tank. Application of a high resolution liquid chromatography/mass spectrometry (LC/MS) technique to a small selection of treated urban effluents indicates that C(60) fullerenes are not yet widely distributed in effluents; however non-point sources cannot be entirely ruled out.

Clinical risk factors and bronchoscopic features of invasive aspergillosis in intensive care unit patients.

INTRODUCTION: Invasive aspergillosis (IA) is an important cause of morbidity and mortality in immunocompromised patients. During recent years, a rising incidence of IA in Intensive Care Unit (ICU) patients has been reported. The patterns of IA related infection may differ according to the type of underlying disease. Unfortunately little is known about the characteristics of IA in ICU patients. In the present study we assessed IA related clinical and bronchoscopy findings in ICU patients. MATERIALS AND METHODS: This study was performed at the ICU units in Sari and Babul, Mazandaran from August 2009 through September 2010. We analysed 43 ICU patients with underlying predisposing conditions for IA. Bronchoalveolar lavage (BAL) samples were collected by bronchoscope twice a weekly. The samples were analyzed by direct microscopic examination, culture and non-culture based diagnostic methods. Patients were assigned a probable or possible diagnosis of IA according to the consensus definition of the EORTC/MSG. RESULTS: Out of 43 suspected patients to IA, 13 (36.1%) cases showed IA. According to criteria presented by EORTC/MSG, they were categorized as: 4 cases (30.8%) of possible IA and 9 (69.2%) of probable IA. The observed mortality was 69.2%. The main underlying predisposing conditions were neutropenia, hematologic malignancy, and COPD. The macroscopic finding in bronchoscopy included of Prulent secretion (46.6%), Mucosal bleeding (30.7%), Mucosal erythema (23%), Trachobronchomalasia (15.3%). CONCLUSION: The diagnosis of IA in patients with critical illness in ICU is even more difficult. The clinical diagnostic process is often dependent on indirect circumstantial data enhancing the probability of IA. Bronchoscopy with inspection of the tracheobronchial tree, sampling of deep airway secretions and BAL can be helpful.

Utilizing stem cells in reconstructive treatments for sports injuries: An innovative approach.

Orthopedic tissue engineering is a rapidly evolving field that holds great promise for the reconstruction and natural repair of bone and joint tissues. Bone loss, fractures, and joint degeneration are common problems that can result from a variety of pathological conditions, and their restoration and replacement are essential not only for functional purposes but also for improving the quality of life for patients. However, current methods rely heavily on artificial materials that can potentially lead to further tissue damage, making tissue engineering a highly attractive alternative. This innovative approach involves the utilization of stem cells (SCs), which are seeded onto a scaffold to form a biological complex. Among these SCs, mesenchymal stem cells (MSCs) extracted from bone marrow and adipose tissue have shown immense potential for bone and joint tissue regeneration. The success of orthopedic tissue engineering is contingent on the careful selection of appropriate scaffolds and inducing molecules, which play a critical role in carrying and supporting cells and inducing their differentiation. This review article comprehensively analyzes the three vital aspects of orthopedic tissue engineering - SCs, scaffolds, and inducing molecules - in order to provide a deeper understanding of this emerging field and its potential for the future of orthopedic medicine.

Comparative transmission of two cucumber mosaic virus isolates by two color morphs of Acyrthosiphon pisum (Harris).

UNLABELLED:  Cucumber mosaic virus (CMV) is one of the most important legume-infecting viruses, which is transmitted effectively by pea aphid Acyrthosiphon pisum (Harris) (Hem: Aphididae). Transmission efficiency of two CMV isolates (As and Kh from cowpea and bean hosts, resp.) by red and green color morphs of pea aphid were evaluated on bean plants. Triple-antibody sandwich ELISA (TAS-ELISA) using CMV-specific monoclonal antibodies revealed that both CMV isolates belonged to the serotype II. Bean plants inoculated by viruliferous aphids were assayed by double-antibody sandwich ELISA (DAS-ELISA) at 16 days post inoculation (dpi). The results showed that the transmission rate of CMV-As by the red morph was significantly higher than by the green morph, resulting in significantly higher transmission rate of the virus (As + Kh) by the red morph than by the green morph, with p≤ 0.1. Similarly, the efficiency of CMV transmission by the red morph of A. pisum was higher than the efficiency of transmission by the green morph. The higher transmission rate and efficiency of CMV by red pea aphid would be important in the epidemiology. Based on these results, we hypothesize that the transmission efficiency of CMV is affected more by the difference in transmission determinants of A. pisum color morphs than by the sequence of virus coat protein determinants. KEYWORDS: Aphididae; Bromoviridae; color polymorphism; transmission efficiency.

Lactobacillus plantarum strains show diversity in biofilm formation under flow conditions.

In many natural and technological applications, microbial biofilms grow under fluid flow. In this project, we investigated the influence of flow on the formation and growth of biofilms produced by gram-positive Lactobacillus plantarum strains WCFS1 and CIP104448. We used an in-house designed device based on a 48-well plate with culture volumes of 0.8 ml, and quantified total biofilm formation under static and flow conditions with flow rates 0.8, 1.6, 3.2 and 4.8 ml/h (with 1, 2, 4 and 6 volume changes per hour) using crystal violet (CV) staining, and determined the number of viable biofilm cells based on plate counts. The amount of total biofilm under flow conditions increased in the CIP 104448 strain, with significantly increased staining at the wall of the wells. However, in the WCFS1 strain, no significant difference in the amount of biofilm formed under flow and static conditions was observed. Plate counts showed that flow caused an increase in the number of viable biofilm cells for both strains. In addition, using enzyme treatment experiments, we found that for WCFS1 in the static condition, the amount of mature biofilm was declined after DNase I and Proteinase K treatment, while for flow conditions, the decline was only observed for DNase I treatment. The CIP104448 biofilms formed under both static and flow conditions only showed a decline in the CV staining after adding Proteinase K, indicating different contributions of extracellular DNA (eDNA) and proteinaceous matrix components to biofilm formation in the tested strains.

Packing of elastic wires in spherical cavities.

We investigate the morphologies and maximum packing density of thin wires packed into spherical cavities. Using simulations and experiments, we find that ordered as well as disordered structures emerge, depending on the amount of internal torsion. We find that the highest packing densities are achieved in low torsion packings for large systems, but in high torsion packings for small systems. An analysis of both situations is given in terms of energetics and comparison is made to analytical models of DNA packing in viral capsids.

Buckling of liquid columns.

Under appropriate conditions, a column of viscous liquid falling onto a rigid surface undergoes a buckling instability. Here we show experimentally and theoretically that liquid buckling exhibits a hitherto unsuspected complexity involving three different modes-viscous, gravitational, and inertial-depending on how the viscous forces that resist bending of the column are balanced. We also find that the nonlinear evolution of the buckling exhibits a surprising multistability with three distinct states: steady stagnation flow, "liquid rope coiling," and a new state in which the column simultaneously folds periodically and rotates about a vertical axis. The transitions among these states are subcritical, leading to a complex phase diagram in which different combinations of states coexist in different regions of the parameter space.

Characterization of a filamentous virus from Bermuda grass and its molecular, serological and biological comparison with Spartina mottle virus.

Bermuda grass with mosaic symptoms have been found in many parts of Iran. No serological correlation was observed between two isolates of this filamentous virus and any of the members of the family Potyviridae that were tested. Aphid transmission was demonstrated at low efficiency for isolates of this virus, whereas no transmission through seed was observed. A DNA fragment corresponding to the 3' end of the viral genome of these two isolates from Iran and one isolate from Italy was amplified and sequenced. A BLAST search showed that these isolates are more closely related to Spartina mottle virus (SpMV) than to any other virus in the family Potyviridae. Specific serological assays confirmed the phylogenetic analysis. Sequence and phylogenetic analysis suggested that these isolates could be considered as divergent strains of SpMV in the proposed genus Sparmovirus.

Identification of Three Strains of Bean common mosaic necrosis virus in Common Bean from Iran.

Bean common mosaic virus (BCMV; genus Potyvirus) has been recognized as a major constraint on bean production in Iran. BCMV and Bean common mosaic necrosis virus (BCMNV) have been reported from bean-growing regions of Iran (2,3), but no attempts were made to differentiate strains of BCMNV. During the early growing seasons of 2003 and 2004, 141 bean leaf samples suspected of BCMV infection were collected from the main bean-producing regions in Tehran Province (Varamin, Damavand, Boein Zahra, Hashtgerd, and Karaj). Symptoms included mild and severe mosaic, leaf curling, malformation, vein-banding, vein-clearing, mottle, and blister on the leaves. In addition, seeds of green bean and Chiti bean (300 each) were obtained from seed lots in Tabriz (East Azarbaijan) and Miyando-Âb (West Azarbaijan) and planted in the greenhouse. Emerging seedlings were subsequently screened for BCMV infection by ELISA and sodium dodecyl sulfate-Ouchterlony double diffusion test. Anti-BCMV polyclonal antisera used in this study included those raised specifically against NL-1, NL-3, NL-4, NL-6, NL-5, NL-8, and NY-15 strains. Seedborne viral infection on newly emerged seedlings varied (2 to 5%) depending on the province and bean cultivar. Seedborne symptoms were characterized as leaf curling, malformation, and necrosis. Among indicator plants used for host range determination, symptom characterization, and biological purification of BCMV, only Chenopodium quinoa, C. amaranticolor, and Phaseolus vulgaris L. cv. Red Kidney developed chlorotic local lesions in response to the BCMV inoculation. Further, P. vulgaris L. cvs. Bountiful, Red Kidney, and Stringless Green Refugee developed leaf mosaic and malformation as a systemic reaction to the inoculation. Of 172 isolates of BCMV investigated, seven representative strains, designated as A (37.2%), B (11%), C (9.3%), D (7.5%), E (12.2%), M (7.5%), and N (15.1%), were selected on the basis of symptom development on the indicator plants and serological tests with strain-specific polyclonal antisera. Thermal inactivation point, dilution end point, and longevity in vitro of the selected BCMNV strains were in the range of 60 to 65°C, -3-(-4), and 3 to 4 days, respectively. Pathogenicity groups of the selected strains were determined by symptom response (sensitive or resistance) at 26 and 32°C in the bean differential host range (1). The designated strains B and E from Tehran Province were assigned to standard strain NL-3 or pathotype VIa, strains A, C, and D from Tehran Province were assigned to standard strain NL-5 or pathotype VIb, and strains M and N from Azarbaijan Province were assigned to standard strain NL-8 or pathotype III. Western immunoblot analysis of viral capsid protein revealed that unlike NL-8, the BCMNV strains NL-3 and NL-5 had the apparent molecular mass of 32 kDa, which was slightly less than that of reference strain NL-8 (33 kDa), thus further confirming that these strains belong to serotype A of BCMV (e.g., BCMNV). Electron microscopy study showed that the virion particles were flexuous, filamentous, and unenveloped. To our knowledge, this is the first report of the differentiation of BCMNV strains from Iran. References: (1) E. Drijfhout. Page 1 in: Agriculture Research Report 872. Centre for Agriculture 46 Publishing and Documentation. Wageningen, the Netherlands, 1978. (2) W. J. Kaiser and G. H. Mossahebi. Phytopathology 64:1209, 1974. (3) N. Shahraeen et al. Plant Dis. 89:1012, 2005.

Characteristics and transmission dynamics of COVID-19 in healthcare workers at a London teaching hospital.

BACKGROUND: Healthcare worker (HCW)-associated coronavirus disease 2019 (COVID-19) is of global concern due to the potential for nosocomial spread and depletion of staff numbers. However, the literature on transmission routes and risk factors for COVID-19 in HCWs is limited. AIM: To examine the characteristics and transmission dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in HCWs in a university teaching hospital in London, UK. METHODS: Staff records and virology testing results were combined to identify staff sickness and COVID-19 rates from March to April 2020. Comparisons were made with staff professional groups, department of work, and ethnicity. FINDINGS: COVID-19 rates in our HCWs largely rose and declined in parallel with the number of community cases. White and non-White ethnic groups among our HCWs had similar rates of infection. Clinical staff had a higher rate of laboratory-confirmed COVID-19 than non-clinical staff, but total sickness rates were similar. Doctors had the highest rate of infection, but took the fewest sickness days. Critical care had lower rates than the emergency department (ED), but rates in the ED declined when all staff were advised to use personal protective equipment (PPE). CONCLUSION: Sustained transmission of SARS-CoV-2 among our hospital staff did not occur, beyond the community outbreak, even in the absence of strict infection control measures in non-clinical areas. Current PPE appears to be effective when used appropriately. Our findings emphasize the importance of testing both clinical and non-clinical staff groups during a pandemic.

Molecular characterization of the plant virus genus Ourmiavirus and evidence of inter-kingdom reassortment of viral genome segments as its possible route of origin.

Ourmia melon virus (OuMV), Epirus cherry virus (EpCV) and Cassava virus C (CsVC) are three species placed in the genus Ourmiavirus. We cloned and sequenced their RNA genomes. The sizes of the three genomic RNAs of OuMV, the type member of the genus, were 2814, 1064 and 974 nt and each had one open reading frame. RNA1 potentially encoded a 97.5 kDa protein carrying the GDD motif typical of RNA-dependent RNA polymerases (RdRps). The putative RdRps of ourmiaviruses are distantly related to known viral RdRps, with the closest similarity and phylogenetic affinity observed with fungal viruses of the genus Narnaviridae. RNA2 encoded a 31.6 kDa protein which, expressed in bacteria as a His-tag fusion protein and in plants through agroinfiltration, reacted specifically with antibodies made against tubular structures found in the cytoplasm. The ORF2 product is significantly similar to movement proteins of the genus Tombusviridae, and phylogenetic analysis supported this evolutionary relationship. The product of OuMV ORF3 is a 23.8 kDa protein. This protein was also expressed in bacteria and plants, and reacted specifically with antisera against the OuMV coat protein. The sequence of the ORF3 protein showed limited but significant similarity to capsid proteins of several plant and animal viruses, although phylogenetic analysis failed to reveal its most likely origin. Taken together, these results indicate that ourmiaviruses comprise a unique group of plant viruses that might have evolved by reassortment of genomic segments of RNA viruses infecting hosts belonging to different eukaryotic kingdoms, in particular, fungi and plants.

Development of a common priority list of pharmaceuticals relevant for the water cycle.

Pharmaceutically active compounds (PhACs), including prescription drugs, over-the-counter medications, drugs used in hospitals and veterinary drugs, have been found throughout the water cycle. A desk study was initiated by the Global Water Research Coalition to consolidate a uniform selection of such compounds in order to judge risks of PhACs for the water cycle. By identifying major existing prioritization efforts and evaluating the criteria they use, this study yields a representative and qualitative profile ('umbrella view') of priority pharmaceuticals based on an extensive set of criteria. This can then be used for further studies on analytical methods, occurrence, treatability and potential risks associated with exposure to PhACs in water supply, identifying compounds most likely to be encountered and that may have significant impact on human health. For practical reasons, the present study excludes veterinary drugs. The pragmatic approach adopted provides an efficient tool to manage risks related to pharmaceuticals and provides assistance for selecting compounds for future studies.

Carnation mottle virus, an important viral agent infecting carnation cut-flower crops in Mahallat of Iran.

One of the most important cut-flower crops grown worldwide on commercial scale is Carnation (Dianthus caryophyllus L.). It's the main production of Mahallat where is one of the most important ornamental plants production centers of Iran. Infection of carnation with pathogens Like viral agents causes economic losses in carnation cut-flower crop. One of the viral agents of this flower is Carnation mottle virus (CarMV) which is the type member of genus Carmovirus and belongs to the Tombusviridae family. It is naturally transmitted by grafting and contacting between plants. Although its infection lead to mild symptims, it weakens the plant to infection by other pathogens. The carnation greenhouses of Mahallat were visited during 2008 January to April and 100 samples with mild mosaic symptom were collected and tested by DAS-ELISA using CarMV specific polyclonal antibody. The results showed that 75% of samples wrere infected with this virus. Mechanical inocubation of Chenopodium quinoa, C. amaranticolor and Spinacea oleracea with extracted crude sap of CarMV infected carnation Leaves in phosphate buffer (pH, 7) resulted in appearance of chlorotic and necrotic local lesions on inoculated leaves 4-7 days after incubation. The virus was partially purified using C. amaranticolor locally symptomatic leaves. Total soluble proteins were extracted from healthy and CarMV infected C. amaranticolor plants and beside partially purified preparation electrophoresed through 15% poly acrylamide get according to SDS-PAGE standard procedure. Protein bands were electroblotted onto nitrocelluse membrane and incubated with CarMV polyclonal during western immunoblot analysis according to standard method. The result revealed a distinc protein band with Mr of 35.5 kDa in total protein preparation of infected plant and viral partial pure preparation, without any reaction in those of healthy plant. RT-PCR carried out using total RNA extracted from infected plant by Rneasy Plant Mini Kit (Qiagen)and a pair of primers, CPu, CPd, corresponding to the flanking region of the virus CP resulted in amplification of a DNA fragment in expected size around 1 kbp.

Sperm characteristics of Chukar partridge (Alectoris chukar) breeders as affected by the addition of calcitriol to the semen extender.

This study was carried out to determine the effect of supplementing the semen extender with calcitriol on in vitro sperm characteristics in Chukar partridges. A total of 60 male Chukar partridges were habituated for semen collection by abdominal massage. Pooled ejaculates from several males were extended (1 to 5 v/v ratio) in the Sexton's diluent containing 0, 24, 48, 96, or 192 µg calcitriol/mL. These concentrations represented 0-, 2-, 4-, 8-, and 16-fold levels of the mean seminal calcitriol concentration, respectively. A total of 12 subsamples from each treatment group were kept at 4 to 5°C or 19 to 24°C for 4, 24, or 48 h. The percentages of motile sperm, live sperm, abnormal sperm, incidence of hypoosmotic swelling (HOS), and thiobarbituric acid reactive species (TBARS) concentrations were determined. The data were analyzed by the xtmixed procedure of STATA software. The percentages of motile sperm, live sperm, abnormal sperm, and seminal TBARS were affected by calcitriol (P < 0.05). There was no effect of treatments on HOS (P > 0.05). There was an interaction effect between calcitriol, storage time, and storage temperature on sperm motility, sperm viability, and seminal TBARS. Supplementation of the diluent with 96 µg calcitriol/mL resulted in the highest sperm motility at 4°C. Also, the same treatment group recorded the highest sperm viability and lowest seminal TBARS at 19 to 24°C. Supplementing the diluent with calcitriol had beneficial effects on spermatozoa; however, the fertility rate of spermatozoa extended in calcitriol-supplemented diluent needs to be determined before the procedure can be recommended for use in artificial insemination programs.

Characterisation of lettuce virus X, a new potexvirus infecting lettuce in Iran.

A virus with flexuous rod-shaped particle morphology was found in samples from lettuce during a survey of viruses infecting lettuce in Tehran province in Iran. This virus was subjected to a complete analysis of its biological and molecular features. The entire nucleotide sequence of the virus was determined, revealing a polyadenylated ssRNA genome consisting of 7,212 nucleotides [without poly (A) tail] and possessing an organization typical for potexviruses. Comparative genome analysis showed that the lettuce virus is closely related to Alstroemeria virus X, narcissus mosaic virus and asparagus virus 3. Based on particle morphology, physico-chemical properties and the complete genome sequence, this virus is a member of a new species in the genus Potexvirus, for which the name lettuce virus X (LeVX) is proposed. Biological assays using an infectious cDNA clone and a wild-type isolate of LeVX revealed that the virus, despite reaching high concentrations in all lettuce cultivars tested, does not cause symptoms in lettuce.