Ovarian transcriptome analysis of diploid and triploid rainbow trout revealed new pathways related to gonadal development and fertility

Triploidisation represents several advantages (e.g. sterility) and therefore is routinely applied in aquaculture of several commercially important fish species, including rainbow trout. The comparative transcriptomic analysis of ovaries of triploid (3N) and diploid (2N) female rainbow trout revealed a total of 9 075 differentially expressed genes (DEGs; 4 105 genes upregulated in 2N and 4 970 genes upregulated in 3N ovaries, respectively). Identified clusters for DEGs upregulated in 3N and 2N ovaries were different, including carbohydrate and lipid metabolic process and transport, protein modification, signalling (related to folliculogenesis) and response to stimulus for DEGs upregulated in 2N, and developmental process, signalling (related to apoptosis, cellular senescence and adherence junctions) and regulation of RNA metabolic process for DEGs upregulated in 3N. The enrichment of processes involved in carbohydrate and lipid metabolism in 2N ovaries indicated high metabolism of ovarian tissue and the energy reservoir generation indispensable during the earliest stages of development. Our results highlight the importance of oocyte hydration along with oestrogen, insulin, leptin, fibroblast growth factor, and Notch signalling and pathways related to the regulation of cyclic adenosine monophosphate (cAMP) levels in proper oocyte meiotic maturation prior to ovulation in 2N ovaries. Conversely, triploidisation may lead to an increase in ovarian cellular senescence and apoptosis, which in turn can result in abnormal gonadal morphology and fibrosis. The downregulation of genes responsible for the precise regulation of meiosis and proper chromosome segregation during meiosis probably affects meiotic maturation via irregular meiotic division of chromosomes. The induction of triploidy of the rainbow trout genome resulted in enhanced expression of male-specific genes, genes responsible for re-establishing the transcriptional balance after genome reorganisation and genes involved in regulatory mechanisms, including gene silencing and DNA methylation. To the best of our knowledge, this is the first genome-wide investigation providing in-depth comprehensive and comparative gene expression patterns in the ovary from 2N and 3N rainbow trout females helping in elucidating the molecular mechanisms leading to impaired gonadal development and sterility of female triploids.

Chromosomal characteristics and distribution of rDNA sequences in the brook trout Salvelinus fontinalis (Mitchill, 1814)

Brook trout Salvelinus fontinalis (Mitchill, 1814) chromosomes have been analyzed using conventional and molecular cytogenetic techniques enabling characteristics and chromosomal location of heterochromatin, nucleolus organizer regions (NORs), ribosomal RNA-encoding genes and telomeric DNA sequences. The C-banding and chromosome digestion with the restriction endonucleases demonstrated distribution and heterogeneity of the heterochromatin in the brook trout genome. DNA sequences of the ribosomal RNA genes, namely the nucleolus-forming 28S (major) and non-nucleolus-forming 5S (minor) rDNAs, were physically mapped using fluorescence in situ hybridization (FISH) and primed in situ labelling. The minor rDNA locus was located on the subtelo-acrocentric chromosome pair No. 9, whereas the major rDNA loci were dispersed on 14 chromosome pairs, showing a considerable inter-individual variation in the number and location. The major and minor rDNA loci were located at different chromosomes. Multichromosomal location (3-6 sites) of the NORs was demonstrated by silver nitrate (AgNO3) impregnation. All Ag-positive i.e. active NORs corresponded to the GC-rich blocks of heterochromatin. FISH with telomeric probe showed the presence of the interstitial telomeric site (ITS) adjacent to the NOR/28S rDNA site on the chromosome 11. This ITS was presumably remnant of the chromosome rearrangement(s) leading to the genomic redistribution of the rDNA sequences. Comparative analysis of the cytogenetic data among several related salmonid species confirmed huge variation in the number and the chromosomal location of rRNA gene clusters in the Salvelinus genome.

Effect of postthaw storage time and sperm-to-egg ratio on fertility of cryopreserved brook trout sperm

The aim of this study was to test the influence of postthaw storage time on sperm motility parameters of brook trout (n = 9). Furthermore, we examined the effect of sperm-to-egg ratios of 300,000:1 and 600,000:1 on fertility of postthaw, cryopreserved, brook trout sperm. The application of a cryopreservation procedure produced very high postthaw sperm motility (56.8 ± 4.0%). The cryopreserved sperm of brook trout could be stored up to 60 minutes without loss of the percentage of sperm motility (52.0 ± 9.0%). The fertilization capacity of brook trout postthaw sperm was comparable with the fertilization rate of fresh semen at a sperm-to-egg ratio as low as 300,000:1 (42.4 ± 14.0% and 36.5 ± 11.0% for eyed and hatched stages, respectively). The possibility of postthaw semen storage for the prolonged time and the obtainment of high fertilization rate at low sperm-to-egg ratio can lead to the significant improvement of brook trout semen cryopreservation procedure.

Risk of human toxocarosis in Poland due to Toxocara infection of dogs and cats

The purpose of this paper was to present the current data on the risk of toxocarosis in humans in Poland and to give an overview of the clinical and diagnostic aspects of the disease. The number of reported clinical cases of Toxocara infection in children in Poland in medical literature has increased recently. The results of field surveys aimed to evaluate the soil contamination with geohelminth eggs conducted during the last few years showed that Toxocara is the most common zoonotic agent in urban public sites and in rural settlements. The questionnaire revealed rural inhabitants' low awareness of zoonotic parasite threats to humans. In particular parents should be advised as to what proper preventive measures to undertake to eliminate the toxocarosis risk factors for children in rural environment. Prevention of initial environment contamination with Toxocara canis and T. cati eggs, which includes proper treatment regimes to eliminate patent infections in dogs and cats and preventing pets from defecating in public areas and private households is vital. To provide the public with suitably presented information as well as pet owners with uniform recommendations, a close collaboration between veterinary and public health professionals is crucial.

Use of eggs derived from the interspecific charr hybrids to induce androgenetic development of the brook charr (Salvelinus fontinalis Mitchill 1814)

Although, brook charr (Salvelinus fontinalis Mitchill 1814) and Arctic charr (Salvelinus alpinus Linnaeus 1758) are able to cross and give fertile offspring, their androgenetic nucleocytoplasmic hybrids are not viable. To overcome incompatibility between the egg cytoplasm of one charr species and the sperm nucleus of another charr species, application of F1 interspecific hybrids as egg donors for the purpose of androgenesis has been proposed. Here, androgenetic development of the brook charr was successfully induced in the brook charr eggs and the eggs derived from the reciprocal brook charr × Arctic charr F1 hybrids. A working androgenesis protocol included inactivation of the maternal nuclear DNA achieved by irradiation of the eggs with 420 Gy of X-rays, insemination of such treated eggs with the haploid sperm cells and exposition of the haploid androgenetic zygotes to the high hydrostatic pressure shock (51.711 MPa for 4 min) applied 420 min after insemination. Androgenetic larvae that hatched from the brook charr and the hybrid eggs were shown to be homozygous brook charr individuals. Androgenetic individuals exhibited 84 chromosomes and 100 chromosome arms (FN), values characteristic for the brook charr diploid cells. Strategy hybridize first than induce androgenesis should be tested in order to provide androgenetic offspring in other salmonids that are able to cross and produce fertile offspring.

[Precocious puberty in a vertically HIV-infected girl]

The authors present the case of a vertically HIV infected, six-year-old girl, with precocious puberty. The late diagnosis of HIV both in the mother and in the child is of significance. Different causes of adrenarche precox are also discussed. In pediatric practice vertical HIV infection should be taken into consideration in differential diagnosis. In routine care of HIV-infected children, monitoring of development including sexual development is indicated. The presence of symptoms of adrenarche precox, as in noninfected children needs in depth diagnostic investigations. The role of HIV infection and of antiretrovirus treatment in the pathogenesis of adrenarche precox remains unclear and needs further investigation.

Changes in sperm parameters of sex-reversed female rainbow trout during spawning season in relation to sperm parameters of normal males

The production of all-female populations has important economic benefits in commercial rainbow trout aquaculture. The procedure commonly implemented to produce all-female stocks centers on the sex reversal of rainbow trout females via the administration of androgens in the early developmental stages, followed by the egg fertilization of normal females with semen from sex-reversed females (srf). However, there is no information regarding the quality of semen from srf rainbow trout throughout the spawning season. This information is critical because the quality of srf semen is highly variable. The aim of the study was to determine the changes in the semen parameters of srf rainbow trout throughout the duration of the spawning season. Sperm concentration, sperm motility parameters, and the biochemical parameters of seminal plasma (protein concentration, antitrypsin activity, osmolality, and lactate dehydrogenase activity) from srf were monitored during the spawning season and compared with normal male rainbow trout. The observed values of sperm, protein concentration, antitrypsin activity, osmolality, and lactate dehydrogenase activity of seminal plasma were all higher in comparison with normal males. Semen from srf was therefore characterized by a lower sperm motility during each period of the spawning season, in comparison with normal males, approximately 1.8, 1.5, and 1.7 times, respectively for the beginning, middle, and end of the spawning season. The percentage of sperm motility from srf and normal males were affected by the spawning season in the same way, as the highest values in the middle of the spawning season demonstrate (60% and 91% for srf and normal males, respectively). Spermatozoa of srf are characterized by a lower speed and a more curvilinear trajectory of movement as compared with that of normal males. The patterns of changes during the spawning season in sperm concentration, sperm motility parameters, as well as osmolality, and lactate dehydrogenase activity of the seminal plasma of srf were different in comparison with normal males. Our results could be important for fish breeders in regard to the spawning control of srf rainbow trout, as well as for the development of short- and long-term sperm storage procedures.

[Evaluation of antibody response to HPV vaccination in HIV infected girls]

BACKGROUND

HIV-infected women have an increased prevalence of HPV infections and high risk of cervical cancer. HPV vaccines seem to be a successive method of prevention in immunocompetent women.

AIM

To evaluate HPV vaccination effectiveness based on the presence of HPV antibodies in HIV infected girls and to establish factors, which influence vaccination effectiveness.

PATIENTS AND METHODS

Post vaccination antibodies were evaluated in 17 HIV -infected girls who received 3 doses of quadrivalent (types 6/11/16/18) HPV vaccine at the mean age of 11,5 years (range 9-17 yr). HPV antibodies were checked 1 month to 2 years (mean 18 months) after the third vaccine dose by ELISA HPV IgG assay (Dia.Pro Diagnostic Bioprobes). All patients have been receiving combined antiretroviral treatment (cART). Analyzed factors included: age at HIV diagnosis, age at the first vaccine dose, Centers for Disease Control and Prevention (CDC) classification at diagnosis, at vaccination and at evaluation.

RESULTS

HPV antibodies were present in all 17 (100%) patients. HIV-infection was diagnosed at the mean age of 3,5 years (range 1 month--10.5 years). Nadir clinical CDC category: 7/17 patients (41%)--A, 5/17 (29,5%)--B, 5/29 (29.5%)--C. Nadir CDC count pointed moderate immunosuppression in 8/17 (47%) children and severe in 9/17 (53%). At vaccination 15/17 girls had CDC classification N1/A1, 2/17 (11.7%) were classified N2. At evaluation all girls had CDC classification N1 or A1. CONCLUSIONS. HPV vaccination in HIV infected girls resulted in successful antibody response. Immune recovery due to cART resulted in a good vaccine response, even in children with prior severe immunodeficiency.

Cystic echinococcosis in a child infected with HIV

Echinococcosis is a parasitic disease caused by the tapeworm Echinococcus granulosus. Echinococcus infection is possible at any age, including childhood. Most of the cases are recognized accidentally. HIV infection in children is rarely diagnosed in Poland. A currently 16-year-old girl was diagnosed with HIV vertical infection at the age of 13. Antiretroviral therapy was started after 6 months of observation. Routine ultrasound examination of her abdomen revealed a cystic lesion in the liver. The IgG ELISA test for E. granulosus infection was negative. However, she was treated with albendazole due to clinical suspicion of echinococcosis. After anti-parasitic treatment, an abdominal ultrasonography (US) and computed tomography (CT) scans were performed and revealed progression of the lesion (one year of observation). As an additional imaging study, biliary tract scintigraphy was done. Localization of the cyst allowed its surgical removal. The surgery was performed under pharmacological protection with albendazole. Histopathology examination confirmed the diagnosis of echinococcosis.Currently, the clinical condition of the patient is good, antiretroviral treatment is effective and repeated abdominal ultrasound is unremarkable. E. granulosus infection in children is rare and may be accompanied by other diseases and infections. Diagnosis is difficult and it is often based on the clinical picture without serological confirmation. Surgical treatment should be supplemented with pharmacological treatment.

Formation of chromosome aberrations in androgenetic rainbow trout Oncorhynchus mykiss

Residues of maternal nuclear DNA in the form of chromosome fragments were observed in the healthy and morphologically normal androgenetic rainbow trout Oncorhynchus mykiss. A hypothetical model for formation of chromosome re-arrangements caused by the incomplete maternal nuclear DNA inactivation in the androgenetic rainbow trout was proposed in the present paper.

Internal frequency conversion extreme ultraviolet interferometer using mutual coherence properties of two high-order-harmonic sources

We report on an innovative two-dimensional imaging extreme ultraviolet (XUV) interferometer operating at 32 nm based on the mutual coherence of two laser high order harmonics (HOH) sources, separately generated in gas. We give the first evidence that the two mutually coherent HOH sources can be produced in two independent spatially separated gas jets, allowing for probing centimeter-sized objects. A magnification factor of 10 leads to a micron resolution associated with a subpicosecond temporal resolution. Single shot interferograms with a fringe visibility better than 30% are routinely produced. As a test of the XUV interferometer, we measure a maximum electronic density of 3x10(20) cm(-3) 1.1 ns after the creation of a plasma on aluminum target.

Karyotype variation in the albino rainbow trout (Oncorhynchus mykiss (Walbaum))

A Robertsonian polymorphism resulting in diploid chromosome number ranging from 59 to 61 and constant chromosome arm number (fundamental number = 104) was observed in the albino rainbow trout (Oncorhynchus mykiss (Walbaum)) from the yellow color strain. In one individual, 90 mitotic chromosomes and 156 chromosome arms were counted, indicating the fish as a triploid. Morphology of the chromosomes, DAPI staining, and the cytogenetic location of 5S rDNA sequences showed sex-related chromosomal heteromorphism in the specimens. Additionally, length polymorphism of the X chromosome was detected in the studied individuals and two morphs of the X chromosome were described, XL and XS, according to the size of its short arm (p). The XS was observed in the female as well as male albino rainbow trout; however, among females, no XSXS genotype was found. After primed in situ labeling with 5S rDNA primers, the p-arms of both types of the X chromosome showed similar hybridization signals. On the other hand, fluorescence in situ hybridization with telomeric PNA (peptide nucleic acid) probe exhibited weak hybridization spots on the p-arm of the XS chromosome compared with the distinct hybridization spots observed on the XL p-arm. This could reflect a different telomere length on the p-arm of the XS and XL chromosomes. Partial translocation and deletion of the X chromosome p-arm are considered to be responsible for the p-arm length difference between the two morphological variants of X chromosome.

Intense gamma-ray source in the giant-dipole-resonance range driven by 10-TW laser pulses

A gamma-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse. The rate of the gamma-ray yield in the giant dipole resonance region (8<E{gamma}<17.5 MeV) was measured, through the radio activation of a gold sample, to be 4 x 10;{8} photons per joule of laser energy. This novel all-optical, compact, and efficient electron-gamma source is suitable for photonuclear studies and medical uses.

[Toxocariasis in children--difficult clinical problem]

Toxocariasis in humans is a zoonosis due to the migration of Toxocara canis or T. cati larvae in human body. This review provides basic information on pathology of infection and clinical signs and symptoms of toxocariasis in children. The cases diagnosed in the recent years in central Poland are presented. The disease was recognised accidentally based on the results of laboratory analysis performed for other reasons, when abnormalities suggesting an active helminthiasis were found (eosinophilia, elevated IgE level and/or anemia). The high rate of soil contamination in households of the patients demonstrated elevated risk of infection and reinfection in both, rural and urban areas. Presented data show the need for educational programs which should be implemented for prevention of Toxocara infection in children.

[HIV infection in children in Poland - clinical advancement at time of diagnosis]

At the end of 2006, there were about 130 children with confirmed HIV infection in Poland, 90% of them being infected vertically.

AIM

to present the causes, the diagnostic procedure of HIV infection and the assessment of clinical staging at diagnosis of vertical infection in a child.

MATERIALS AND METHODS

between 1987-2006 there were 86 HIV infected children (45 male, 41 female) treated in our Department. 78 children had been infected vertically, 8 by other route. Reasons for HIV testing in children and clinical staging at diagnosis were analysed in vertically infected children. The patients were divided into two groups: I - diagnosed because of clinical signs and symptoms, II - because of knowledge of HIV positive status in family members.

RESULTS

there were 22/79 children in group I and 56/79 in group II. Vertical HIV infection diagnosis was confirmed at the age from 1 month to 11 years, the mean age was: 26 months - in group I, 25 months - in group II. During the first year of life HIV infection was diagnosed in 36 children (33% of them having AIDS, 36% severe immunodeficiency), at the age of 12-35 months in 22 children (23% of them having AIDS, 32% severe immunodeficiency) and above 35 months in 20 children (15% of them having AIDS, 35% severe immunodeficiency), respectively. Children diagnosed because of clinical manifestations were more likely to have AIDS (p<0.01) and severe immunodeficiency (p<0.07).

CONCLUSIONS

early diagnosis in children relies on the knowledge on the mother's HIV infection positive status. In Poland vertical HIV infection diagnosis is established late (mean: above 2 years), often at the advanced stage of the disease.

[The risk of vertical HCV transmission in children born to HIV infected mothers]

OBJECTIVE

The aim of the study was to evaluate the incidence of mother-to-infant HCV transmission in children born to HIV positive mothers, to qualify the risk factors of the mother-to-child HCV transmission, to settle of conduct diagnostic principles in a child after exposition on HIV and HCV.

METHODS

52 children, born to 52 HIV-infected mothers were studied between June 2001 and September 2005. The full regimen of investigations was executed in 44 children, 7 fell out from the observation, 1 child was below 12th month of life. The course of gestation, mode and duration of delivery were examined. The following laboratory tests were done: alanine aminotrnsferase (ALT) activity, AbHCV assay in 1s and 13th month of life (EIA--third generation) and genetic material HCV (Amplicor HCV assay v. 2.0--Roche). At the same time the diagnostics of HIV vertical infection was made. HCV/HIV coinfections was diagnosed in 43/52 mothers. HCV vertical transmission was diagnosed based on at least twice tested existence of HCV-RNA in serum in the first year of life and/or HCV-Ab presence in a child >12th month of life.

RESULTS

HCV-antibodies in the first month of life were present in 40/52 children (76.9%). HCV-RNA diagnosed by RT-PCR was detected in 7/43 children (16.2%): in 1 child transient viremia was observed, 6 children had chronic HCV infection. Symptoms of hepatitis infection were observed in 5 among 7 children with HCV transmission. HCV vertical transmission appeared in children of mothers with HCV viremia above 10(5) copies/ml. Vaginal delivery lasting over 4 hours after membrane rupture and emergency cesarean section were statistic significant risk of HCV transmission (significant data--chi2(1) = 5.01, p < 0.05). HIV infection was diagnosed in 4 children, there was no case with coinfection HIV/HCV.

CONCLUSIONS

. All children born to HIV positive mothers need diagnostics of HCV vertical infection, the risk of vertical HCV transmission is high (16.2%). The risk factors of HCV vertical transmission included: high level of HCV viremia in the mother (>10(5) copies/ml), prolonged vaginal delivery (>4 hrs after membrane rupture) and emergency cesarean section. Children from vertical HCV exposition should be followed up at least for 24 months.

[20-years experiences of HIV infected children's care]

OBJECTIVE

The aim was to present the 20-years experiences of medical care of children borne to HIV(+) mothers and HIV infected children.

METHODS

Between 1987 and 2006 year 305 children borne to HIV(+) mother were investigated. The risk of vertical transmission was estimated. We analyzed routs of HIV transmission, the reasons of HIV diagnosis, HIV staging at diagnosis, HBV and HCV coinfection, ART treatment and its efficacy.

MAIN OBSERVATIONS AND RESULTS

HIV infection was confirmed: 75 cases of vertical HIV infection and 8 children infected in other ways. 260 children were borne after 1994 year (the date of introducing recommendation of the use of ART to reduce perinatal transmission of HIV). 158 of them received prophylaxis of vertical HIV infection. The risk of HIV vertical in children receiving prophylaxis was 5% comparing to 45.6% risk in children without prophylaxis regimens. 66 children receive ART regimen. The efficacy of treatment was: viral 85%, immunological: 89% and clinical: 85% improvement.

CONCLUSIONS

HIV testing should be offered to every women in the child-bearing age. Current prophylaxis, which suppress maternal VL HIV below detection level, decrease the risk of vertical HIV transmission to 0-1%. The child born to HIV(+) mother requires early diagnostics of HIV, HBV, HCV infections. Because of rapid progression of the disease, the HIV infected child should be diagnosed and treated since the first year of life. Properly treated children reach to mature age.

Coherent wake emission of high-order harmonics from overdense plasmas

We present a new mechanism for high-order harmonic generation by reflection of a laser beam from an overdense plasma, efficient even at moderate laser intensities (down to Igamma2 approximately 4x10(15) W cm-2 microm2). In this mechanism, a transient phase matching between the electromagnetic field and plasma oscillations within a density gradient leads to the emission of harmonics up to the plasma frequency. These plasma oscillations are periodically excited in the wake of attosecond electron bunches which sweep across the density gradient. This process leads to a train of unevenly spaced chirped attosecond pulses and, hence, to broadened and chirped harmonics. This last effect is confirmed experimentally.

[Tuberculosis in HIV infected children]

Tuberculosis (TB) is important threat in HIV-infected people. Although there is slow but constant decline TB-infections among adults and children in Poland, about 30% HIV-(+) adults is coinfected with TB. There were 12 cases of TB in HIV(+) children diagnosed in Department of Pediatric Infectious Diseases in 1994-2005. The aim was analysis of reasons for TB diagnostic tests in HIV (+) children, coinfection HIV and TB and efficacy of anti TB treatment. TB diagnostics was performed in 23 children because of clinical indications (15/23) and conversion or excessive skin tests (8/23). There were bacteriological and radiological exams done in all cases of TB suspicion. When active TB was diagnosed there were 4 tuberculostatic drugs used (6-12 months). In latent or unlocalized TB-INH was used for 12 months.

RESULTS

12 cases of TB infection were diagnosed: active TB--4, BCG-itis--1, latent--1 and unlocalized TB--6. In 10 cases TB infection was excluded. All cases of tuberculostatic treatment was successful. 5/12 cases are presently treated.

CONCLUSIONS

Skin test is lonely, generally used method of TB control in HIV (+) children without clinical manifestations of TB. There is a necessity of diagnosis and chemoprophylaxis in all cases of conversion or enlarged (above 10 mm, vesicularis) skin test. TB diagnosis is an indication for HIV diagnostics.

Effects of UV irradiation and hydrogen peroxide on DNA fragmentation, motility and fertilizing ability of rainbow trout (Oncorhynchus mykiss) spermatozoa

Preservation of DNA integrity is essential for protection of sperm quality. This study examined, with the use of comet assay, DNA fragmentation of rainbow trout (Oncorhynchus mykiss) spermatozoa subjected to UV irradiation (2,075 microW/cm(2), 0-15 min) or oxidative stress induced by hydrogen peroxide (0-20mM). Sperm motility and fertilizing ability were also measured. A dramatic increase in DNA fragmentation was recorded after 5 min UV irradiation but no significant changes in sperm motility were observed at this time. Longer irradiation resulted in a decrease in motility parameters and further increase of DNA fragmentation. UV irradiation caused a clear decrease in the percentage of eyed embryos and most of the embryos did not hatch. When highly diluted sperm suspensions (50,000-fold) were exposed to 0.1mM H(2)O(2) evident increase in DNA fragmentation was observed. On the other hand, when more concentrated sperm suspensions (diluted only 40-fold) were employed (in order to conduct motility and fertilization measurements at the same time) 1-20mM H(2)O(2) caused only moderate increase in DNA fragmentation and dose-dependent decline in sperm motility and fertilizing ability. This suggests that toxic effects of H(2)O(2) were primarily related to inhibition of sperm motility. Our results demonstrate that comet assay can be used for monitoring the effectiveness of fish sperm DNA inactivation by UV irradiation. Therefore, the comet assay together with sperm motility analysis can be applied in optimization works of gynogenetic procedures in fish. Lack of effectiveness of H(2)O(2) in inducing major DNA fragmentation suggests presence of mechanisms of antioxidative defense in rainbow trout spermatozoa.

Probing hot and dense laser-induced plasmas with ultrafast XUV pulses

In this Letter, we demonstrate the instantaneous creation of a hot solid-density plasma generated by focusing an intense femtosecond, high temporal contrast laser on an ultrathin foil (100 nm) in the 10(18) W/cm2 intensity range. The use of high-order harmonics generated in a gas jet, providing a probe beam of sufficiently short wavelengths to penetrate such a medium, enables the study of the dynamics of this plasma on the 100 fs time scale. The comparison of the transmission of two successive harmonics permits us to determine the electronic density and the temperature with accuracies better than 15%, never achieved up to this date in the regime of laser pulses at relativistic intensity.

Blood cells in rainbow trout Oncorhynchus mykiss milt: relation to milt collection method and sampling period

The presence of blood cells in milt of rainbow trout (Oncorhynchus mykiss) collected every week between the middle at the end of the spawning season, either by stripping or by catheterization was investigated. Basic sperm biological and biochemical characteristics were also evaluated. Because milt often becomes contaminated with blood during collection, we also studied the influence of experimental blood contamination on sperm motility and biochemical parameters of seminal plasma. We demonstrated the presence of blood cells (erythrocytes, lymphoid, and phagocytes) in rainbow trout milt collected by both methods. Both sampling period and collection method influenced sperm characteristics, however the relationship between these characteristics and blood cells are not clear at present. A high number of blood cells in milt was found in some samples, possibly due to inflammation, because at the same time we observed bacteria and elevated levels of protein and antiproteinase activity in contaminated samples. Experimental contamination of milt with blood did not influence sperm motility, protein concentration and LDH activity of the 5-day-stored semen. Our study demonstrated that blood cells were present in rainbow trout milt. Blood cells may also appear in milt as a result of bleeding and their elevated levels are present during inflammation.

The stability of telomereless chromosome fragments in adult androgenetic rainbow trout

The study provides new data on the stability of gamma radiation-induced chromosome fragments of a putative maternal nuclear genome in an androgenetic vertebrate, rainbow trout (Oncorhynchus mykiss Walbaum). The fragments were found in five of 16 examined individuals and they were mostly centromeric parts of metacentric or subtelocentric chromosomes. Chromosome fragments were identical in all cells of a given androgenetic individual,indicating that segregation of chromosome fragments is active from the early cell divisions. Most of the fragments were telomereless, i.e. they had no telomeric sequences on their ends. This shows that telomeres are not necessary for stability of chromosomal structures in a vertebrate genome. In one individual, the interstitial telomeric sites were found in chromosomes, which could be the effect of joining chromosome fragments.

Cell-mediated immunity in yellow forms of rainbow trout

The aim of the present study was to investigate possible pleiotropic effects of the genotypes controlling the palomino and albino coloration on blood phagocyte and lymphocyte activity. The results showed that the wild coloured trout has a higher metabolic and potential killing activity of blood phagocytes, compared to albino and palomino coloured trout. The proliferative response of blood lymphocytes stimulated by ConA or LPS indicated a similar pattern. The results showed that lymphocyte proliferation was statistically significantly higher in wild coloured trout, compared to albino and palomino trout.

Hot-electron influence on L-shell spectra of multicharged Kr ions generated in clusters irradiated by femtosecond laser pulses

Strong L-shell x-ray emission has been obtained from Kr clusters formed in gas jets and irradiated by 60-500-fs laser pulses. Spectral lines from the F-, Ne- Na-, and Mg-like charge states of Kr have been identified from highly resolved x-ray spectra. Spectral line intensities are used in conjunction with a detailed time-dependent collisional-radiative model to diagnose the electron distribution functions of plasmas formed in various gas jet nozzles with various laser pulse durations. It is shown that L-shell spectra formed by relatively long nanosecond-laser pulses can be well described by a steady-state model without hot electrons when opacity effects are included. In contrast, adequate modeling of L-shell spectra from highly transient and inhomogeneous femtosecond-laser plasmas requires including the influence of hot electrons. It is shown that femtosecond-laser interaction with gas jets from conical nozzles produces plasmas with higher ionization balances than plasmas formed by gas jets from Laval nozzles, in agreement with previous work for femtosecond laser interaction with Ar clusters.

[Hepatitis C--epidemiology, diagnosis and treatment in children]

OBJECTIVE

Epidemiology dates of hepatitis C in children are not well known because of usually asymptomatic course of disease. Vertical transmission has became one of the most common route of hepatitis C virus infection in children.

METHODS AND MAIN OBSERVATIONS

Twenty one infants of twenty HCV positive mothers were studied from 1998 to 2000 in the Clinic of Infectious Disease in Childhood of Medical University in Warsaw. Five of the infants were HCV RNA positive. All uninfected children became HCV-antybody negative by 12 months.

RESULTS AND CONCLUSIONS

Chronic infection is common in most cases of HCV infection, but the disease progression is slower than in adults. Experience of treatment of chronic hepatitis C in children is limited, with about 40% having sustained response to the interferon therapy. Combinated therapy with interferon and ribavirin may give a better response.

[Vertical HIV transmission in Poland from 1989-2000]

OBJECTIVE

To evaluate vertical HIV transmission rate in Poland.

METHODS

132 children born to HIV positive mothers were evaluated and their HIV infection status was established.

MAIN OBSERVATIONS AND RESULTS

There are 60 HIV-infected children in Poland. 92% of them have been infected perinataly. From 1989 to 1994 the rate of vertical transmission was 25%. Since September 1994, when prophylactic strategies were started, the rate has decreased to 21.4% (in children with prophylaxis to 1.8%).

CONCLUSIONS

Vertical HIV infection prophylactic programs rely on women's knowledge about their HIV infection status and are the only way to diminish pediatric HIV infection worldwide. The authors show difficulty of providing proper medical care of HIV positive women in Poland and underly the need of voluntary HIV testing for all women before pregnancy.

Space- and time-resolved density measurements of a high-intensity laser-produced plasma for x-ray laser studies

We present a detailed study on the spatiotemporal density evolution of a plasma created by optical-field ionization of a high-pressure pulsed gas jet by a 10-TW, 60-fs Ti:sapphire laser. The plasma dynamics has been studied on a 17-ns time scale with a 60-fs time resolution and a 5-microm space resolution using a Mach-Zehnder interferometer. The density profile and the plasma radial expansion were accurately measured for conditions relevant to x-ray laser schemes in H-like nitrogen which were recently proposed [S. Hulin et al., Phys. Rev. E 61, 5693 (2000)]. The results were reproduced well by hydrocode simulations that allowed to infer the plasma temperature.

Spatially resolved x-ray spectroscopy investigation of femtosecond laser irradiated Ar clusters

High temperature plasmas have been created by irradiating Ar clusters with high intensity 60-fs laser pulses. Detailed spectroscopic analysis of spatially resolved, high resolution x-ray data near the He(alpha) line of Ar is consistent with a two-temperature collisional-radiative model incorporating the effects of highly energetic electrons. The results of the spectral analysis are compared with a theoretical hydrodynamic model of cluster production, as well as interferometric data. The plasma parameters are notably uniform over one Rayleigh length (600 microm).

Androgenesis in rainbow trout using cryopreserved spermatozoa: the effect of processing and biological factors

In addition to producing homozygous lines for biomedical and genomic research and monosex stocks for commercial purposes, androgenesis is the biotechnology considered most promising and reliable for recovering complete nuclear genome information from cryopreserved fish cells. That is because procedures of cryopreserving spermatozoa, contrary to procedures for oocytes or entire eggs, are being well developed. Application of androgenesis in genome banking programs addresses the needs of both the aquaculture industry (safeguard for valuable strains and lines) and natural resource conservation (in vitro protection of endangered species or populations). The present study was focused on successful production of an androgenetic rainbow trout stock using cryopreserved spermatozoa. Our report constitutes the first time a full factorial analysis of processing and biological factors affecting androgenesis efficacy has been presented. Also for the first time, the survival of androgenetic individuals during 2 years of life was recorded. Remarkably high survival rates were observed in one of the two experiments-up to 42.5 +/- 2.8% of hatched larvae, 22.5 +/- 0.1% of swim-up larvae and 10.5% of androgenetic alevins 0.4 g. Mortality rates in androgenetic groups were high especially during the first 6 months. In all, 114 androgenetic individuals (0.9%) survived 2 years. Cryopreservation of spermatozoa generally did not affect androgenesis efficiency significantly, however, this effect was significantly dependent on the method of ploidization shock and on the duration of treatment. Significant interactions were revealed between the irradiation dose and the magnitude of pressure applied, and between the treatment of sperm and duration of pressure shock. Individual variability of spermatozoa donors significantly affected androgenesis efficiency regardless of their genetic (outbred or inbred) origin. Genetic source of the oocytes, contrary to spermatozoa, proved to be an important factor. Following findings of other researchers that androgenesis using cryopreserved spermatozoa is possible, we demonstrated that viable stock could be successfully established from cryopreserved nuclear genome information. Complex statistical analysis of previously developed procedures resulted in information-rich data regarding factorial interactions helpful for developing protocols in genome-restoration programs.

Effect of extender composition and equilibration time on fertilization ability and enzymatic activity of rainbow trout cryopreserved spermatozoa

The effects of extender composition and equilibration time on fertilizing ability of cryopreserved spermatozoa from rainbow trout, Oncorhynchus mykiss, were investigated. In addition, enzyme activity in supernatants from thawed sperm was assessed. The use of the two extenders: Erdahl & Graham's + 10% DMA (dimethyl acetamide) + 10% egg yolk and 0.3 M glucose + 10% DMA yielded the highest post-thaw fertilization rates. We observed interactions between extender constituents and the equilibration of diluted semen. This indicates a multifactorial effect of the extender constituents on spermatozoal resistance against injuries. The 10-min equilibration of spermatozoa in extender before freezing generally lowered the fertilization ability of spermatozoa, except for DMA-based extenders. The addition of egg yolk to the extender was generally beneficial, especially in DMA- and DMSO-based extenders. The use of low-density lipoprotein fraction showed no advantage to full-yolk or free-of-yolk extenders. Aspartate aminotransferase and lactate dehydrogenase leakage from damaged spermatozoa correlated negatively with the ability of cryopreserved spermatozoa to fertilize eggs. Each factor tested, when analyzed separately, did not give general information about its effect on the fertilization ability of cryopreserved sperm. The multifactorial analysis of the important factors in cryopreservation of trout spermatozoa showed their cumulative effect. This is the most likely reason for divergent information reported elsewhere on the effect of various factors in the cryopreservation of rainbow trout spermatozoa.

Activity of aspartate aminotransferase and acid phosphatase in cryopreserved trout sperm

Milt of brown, rainbow and brook trout was cryopreserved. Activity of aspartate aminotransferase (AspAT) and acid phosphatase was assayed both in supernatants and in spermatozoa obtained from thawed sperm samples; additionally, post-thaw motility was evaluated. Enzyme activities differed according to fish species and were strongly affected by the type of cryoprotectant used. The activity in supernatants was usually higher than that in spermatozoa because of protein leakage from injured cells. AspAT activity in cryopreserved spermatozoa correlated positively with fertilization success in all three species. There was a negative correlation between activity of extracellular (supernatant) AspAT and fertilization rates in variants with dimethyl sulfoxide and dimethylacetamide-based extenders. The motility of thawed sperm, determined microscopically, provided some information on the cryopreservation efficiency of trout milt.

Frequency analyses of active NORs in nuclei of artificially induced triploid fishes

The correspondence between increased numbers of both chromosomal and nuclear NORs and artificially induced triploidy in three fish species (rainbow trout, Oncorhynchus mykiss; common carp, Cyprinus carpio; and tench, Tinea tinea) has been confirmed by CMA3 fluorescence and Ag-staining. The frequencies of cell nuclei with one, two and three active NORs, as revealed by Ag-staining, has been analyzed statistically to find the minimum cell number which verifies the increased ploidy level. A minimum sample size of about 80 cells exhibiting three active NORs is sufficient to confirm triploidy in all three species and may be of use for categorising other ploidy-manipulated fish species.