bluuebunny/crossref_metadata_2025 huggingface dataset:
ABORTION AS A BACKUP METHOD FOR CONTRACEPTIVE FAILURE IN CHINA
Authors: WANG DUOLAO , YAN HONG , FENG ZHONGHUI
Published: February 2004

Contraceptive failure rates for modern methods including sterilization are reported to be high in China, but little is known about the consequence of contraceptive failure and characteristics of women who decide to have an abortion if a contraceptive failure occurs. Using 6225 contraceptive failures from the 1988 Chinese Two-per-Thousand Fertility Survey, this study examines the resolution of contraceptive failure and assesses the impact of some women’s sociodemographic characteristics on the decision to terminate contraceptive failure in abortion. This study has three important findings: (1) The abortion rate was 50·1%, 75·3% and 80·2% for IUD, condom and pill failures, respectively; (2) The abortion rates differed by contraceptive method and women’s social and demographic characteristics. In particular, a woman with just one child was most likely to have the contraceptive failure aborted; (3) Some women experienced repeated abortions because of contraceptive failure. The results suggest that abortion was a backup method if contraception failed in China and the correlates of aborting an unwanted pregnancy reflect the strong impact of the Chinese family planning programme.
Molecular epidemiology of Shigella flexneri in a diarrhoea-endemic area of Lima, Peru
Authors: FERNANDEZ-PRADA C. M. , VENKATESAN M. M. , FRANCO A. A. , LANATA C. F. , SACK R. B. , HARTMAN A. B. , SPIRA W.
Published: February 2004

A year-long community-based study of diarrhoeal diseases was conducted in Canto Grande, a periurban community in Lima, Peru. In 109 (34%) houses out of 323 that were visited, at least one individual was detected with shigellosis. The frequency of the 161 shigella isolates obtained was as follows: 117 S. flexneri (73%), 21 S. boydii (13%), 15 S. dysenteriae (9%), and 8 S. sonnei (5%). Using a non-radioactive ipaH gene probe as a molecular epidemiological tool, a total of 41 S. flexneri strains were shown to be distributed in 25 intra-family comparisons by pairs (icp). Further subdivision, based on a comparison of the serotype, plasmid profile, antibiotic resistances and ipaH hybridization patterns indicated that Group I, with 11 icp (44%), had strains that were identical, Group II with 8 icp (32%), had strains that were different and Group III with 6 icp (24%), had strains with the same serotype and identical ipaH profiles but with differences in other markers. This data indicates that a diversity of shigella clones circulated in this community resulting from both clonal spread and horizontal transfer of genetic elements. Furthermore, ipaH profiling of isolates can be used not only to differentiate between closely related shigella strains but also with other parameters, help to understand the dynamics of the generation of new clones of pathogenic bacteria.
Risk factors for helicobacter pylori infection in children: is education a main determinant?
Authors: MOREIRA E. D. , SANTOS R. S. , NASSRI V. B. , REIS A. T. , GUERRA A. L. , ALCÂNTARA A. P. G. , MATOS J. F. , CARVALHO W. A. , MOURA C. G. G. , SILVANI C. S. , SANT'ANA C. S.
Published: February 2004

To investigate potential risk factors associated with Helicobacter pylori (Hp) infection, we performed a case-control study in 167 consecutively selected hospitalized children in Salvador, Brazil. Hp infection was identified by the presence of IgG against Hp in serum samples. Data were gathered using a structured questionnaire, 38·3% children were found to be seropositive and classified as cases, and 61·7% were seronegative controls. After multivariate analysis, independent variables associated with Hp infection included: the educational attainment of the child's provider [ges ]11 years (OR 0·1, 95% CI 0·01–0·9), poor garbage disposal service (OR 2·2, 95% CI 1·0–4·9), thumb sucking (OR 4·6, 95% CI 1·1–19·8), brushing teeth more than once a day (OR 5·6, 95% CI 1·8–17·7), having a pet dog (OR 2·5, 95% CI 1·0–6·1), and a history of chronic urticaria (OR 4·0, 95% CI 1·5–10·8). The risk factors identified are consistent with some, but not all, previous studies supporting either oral–oral or faecal–oral transmission of Hp. Our data suggested that a higher educational attainment might play an important role in preventing Hp infection.
A cluster of leptospirosis cases in canoeists following a competition on the River Liffey
Authors: BOLAND M. , SAYERS G. , COLEMAN T. , BERGIN C. , SHEEHAN N. , CREAMER E. , O'CONNELL M. , JONES L. , ZOCHOWSKI W.
Published: February 2004

On 6 November 2001, a possible case of leptospirosis was notified in a canoeist following a white-water event on the River Liffey. It emerged that a second race participant was also a possible case. An outbreak control team coordinated the epidemiological investigation, laboratory investigation, environmental assessment, communication and control measures. A cluster of six laboratory-confirmed cases of leptospirosis, serologically Leptospira interrogans serogroup Icterohaemorrhagiae was found. The attack rate was 9·2% (6/65). Fever, chills, red eyes and shortness of breath were significantly associated with being a confirmed case. Five cases were hospitalized. Swallowing more than one mouthful of water was associated with an increased risk of developing leptospirosis. Increased rainfall and release of hydroelectric water may have contributed to this outbreak. A multidisciplinary approach and use of the Internet and e-mail facilitated rapid and effective communication.
Molecular characterization of the genotype G9 human rotavirus strains recovered in Palermo, Italy, during the winter of 1999–2000
Authors: ARISTA S. , GIAMMANCO G. M. , De GRAZIA S. , MIGLIORE M. C. , MARTELLA V. , CASCIO A.
Published: February 2004

Among the known human rotavirus serotypes, types G1–G4 are ubiquitous and account for >80% of global human rotavirus strains. Since 1994 an increase in reports of G9 serotype isolates has been observed in both developed and developing countries. In the winter season of 1999–2000 we detected the appearance of G9 rotavirus in Palermo, Italy, accounting for 19% of all rotaviruses circulating in our geographical area. Some of these Italian G9 isolates have been submitted to partial sequencing of their VP7 gene. All of them showed complete nucleotide identity suggesting a clonal origin. The Italian VP7 sequences were found to be very closely related to that of other G9 strains recently isolated in Europe, America, Africa and Asia. Our results confirm that G9 strains circulating worldwide since 1994 are closely related genetically in their VP7 genes.
Molecular characterization of Salmonella enterica subsp. enterica serovar Typhimurium DT1 isolates
Authors: LINDQVIST N. , HEINIKAINEN S. , SIITONEN A. , PELKONEN S.
Published: February 2004

Salmonella Typhimurium DT1 is endemic to Finland and has caused human outbreaks since the 1960s. Domestic DT1 isolates (n=235) from 1972 to 1999 from human cases, animals and other sources, as well as foreign DT1 isolates from human cases (n=20) were analysed by molecular methods. Pulsed-field gel electrophoresis (PFGE) yielded 38 XbaI profiles. Of these, XbaI profile 10 was seen in 49% (125/255) of the isolates. Twelve IS200 profiles were obtained; the most common IS200 profile D was seen in 64% (33/52) of the isolates. Two clusters were formed by compilation of the XbaI–, BlnI– and SpeI–PFGE and IS200 profiles and possession of the serovar-specific virulence plasmid. The major cluster contained eight IS200 profiles, including IS200 profile D and XbaI profile 10, and had no virulence plasmid, and can be regarded as typical of the endemic Typhimurium DT1 infection.
Invasive Streptococcus pneumoniae isolates from Argentinian children: serotypes, families of pneumococcal surface protein A (PspA) and genetic diversity
Authors: MOLLERACH M. , REGUEIRA M. , BONOFIGLIO L. , CALLEJO R. , PACE J. , DI FABIO J. L. , HOLLINGSHEAD S. , BRILES D.
Published: February 2004

PspA is an antigenically variable virulence factor of Streptococcus pneumoniae that inhibits complement deposition and is a potential candidate for human vaccines. Of 64 published strains 96% are in PspA families 1 and 2; optimal protection is family-specific. Effective development of a PspA-containing vaccine requires more information about the PspA family of strains in parts of the world where the vaccine is most needed. In these studies we observed that of 149 isolates (of 19 capsular types) from Argentina, 54·4% were family 1, 41·6% were family 2 and 4·0% expressed both family 1 and family 2 PspAs. Box typing revealed the Argentinian strains to be from at least 10 clonally related groups.
Salmonella enterica serotype Javiana infections associated with amphibian contact, Mississippi, 2001
Authors: SRIKANTIAH P. , LAY J. C. , HAND S. , CRUMP J. A. , CAMPBELL J. , VAN DUYNE M. S. , BISHOP R. , MIDDENDOR R. , CURRIER M. , MEAD P. S. , MØLBAK K.
Published: February 2004

Salmonella Javiana is a Salmonella serotype that is restricted geographically in the United States to the Southeast. During the summer of 2001, the number of reported S. Javiana infections in Mississippi increased sevenfold. To identify sources of infection, we conducted a case-control study, defining a case as an infection with S. Javiana between August and September in a Mississippi resident. We enrolled 55 cases and 109 controls. Thirty (55%) case patients reported exposure to amphibians, defined as owning, touching, or seeing an amphibian on one's property, compared with 30 (29%) controls (matched odds ratio 2·8, P=0·006). Contact with amphibians and their environments may be a risk factor for human infection with S. Javiana. The geographic pattern of S. Javiana infections in the United States mimics the distribution of certain amphibian species in the Southeast. Public health officials should consider amphibians as potential sources of salmonellosis, and promote hand washing after contact with amphibians.
Temporal trends in circulating Bordetella pertussis strains in Australia
Authors: POYNTEN M. , McINTYRE P. B. , MOOI F. R. , HEUVELMAN K. J. , GILBERT G. L.
Published: February 2004

Australia experienced a resurgence of pertussis in the 1990s despite improved vaccine coverage. Although much of the increase was attributable to increased detection of cases in older persons with waning immunity by serology, vaccine changes or alterations in circulating Bordetella pertussis strains may also have contributed. We determined the frequency of variants of B. pertussis pertactin (prn), and pertussis toxin subunit 1 (ptxS1) genes, restriction fragment length polymorphism (RFLP) types and fimbrial serotypes prevalent in Australia prior to, and during the 1990s. Ampoules of the whole-cell vaccine in use prior to 1999 and 84 B. pertussis isolates stored between 1967 and 1998 by laboratories around Australia were analysed. One pertactin allele, Prn3, not detected before 1985, was found in 24 out of 57 (42%) isolates between 1989 and 1998 (P<0·0001). PtxS1A was found in all isolates. IS1002 type 29, found in 17 out of 31 (55%) isolates tested, was the predominant RFLP type. The only difference in fimbrial serotype distribution between the time-periods was an increase in serotype 3 (P=0·054). The whole-cell vaccine contained only the alleles prn1 and ptxS1A. Antigenic shift in B. pertussis may have contributed to the re-emergence of pertussis in Australia. Monitoring these trends will be important as acellular vaccines are introduced and changes are made to pertussis vaccine schedules.
Escherichia coli O157:H7 outbreak linked to salami, British Columbia, Canada, 1999
Authors: MacDONALD D. M. , FYFE M. , PACCAGNELLA A. , TRINIDAD A. , LOUIE K. , PATRICK D.
Published: February 2004

An outbreak of E. coli O157:H7 infections was identified in November 1999 with a fivefold increase in the occurrence of laboratory-confirmed cases of E. coli O157:H7 infection. A matched case-control study was conducted. Samples of food from cases and from retailers were analysed for the presence of E. coli O157:H7. A total of 143 cases were identified over a 12-week period with the same pulsed-field gel electrophoresis (PFGE) pattern. The case-control study found that Company A salami was significantly associated with illness (Mantel–Haenszel matched odds ratio 10·0, 95% CI 1·4–434, P=0·01). Company A salami tested positive for E. coli O157:H7 and isolates had the same PFGE pattern as case isolates. An immediate voluntary national recall of Company A dry fermented meat products took place. Findings from the investigation of this outbreak suggest that the hold-and-test option may not be adequate to prevent shiga-toxigenic Escherichia coli (STEC) infection in salami consumers.
A seroprevalence study of poliovirus antibody among primary schoolchildren in Korea
Authors: JEE Y. M. , CHEON D. S. , KIM K. S. , LEE S. H. , YOON J. D. , LEE S. W. , GO U. , YANG B. K. , KI M. R. , CHOI B. Y. , CHO H. W.
Published: February 2004

We aimed to determine the seroprevalence of poliovirus antibody in Korea by using the cell culture neutralization method recommended by the WHO. A total of 500 sera collected from children at eight primary schools in Kyunggi province were used for this study. We found that 82·2% of children were positive for all three types of poliovirus and antibody-positive rates for types I, II and III were 94·4, 96·6 and 86·8% respectively, indicating that seropositive rates for types I and II were considerably higher than for type III (P<0·0001). This result implies that the type III component of the oral polio vaccine should be evaluated further. Although a greater number of children, including young infants, need to be tested for seroprevalence, this study still provides us with valuable information on the effectiveness of vaccination against polioviruses in Korea.
Case-control study of risk factors for high within-flock small-ruminant brucellosis prevalence in a brucellosis low-prevalence area
Authors: LITHG-PEREIRA P. L. , ROJO-VÁZQUEZ F. A. , MAINAR-JAIME R. C.
Published: February 2004

A case-control study was conducted in a brucellosis low-prevalence area of NW Spain to determine factors associated with high within-flock small-ruminant brucellosis prevalence in 1998. Forty-one cases and 69 controls were selected and information from both official sources and personal interviews was retrieved for every flock. The relationship between variables obtained and flock status was assessed by unconditional multivariable logistic regression analysis. The introduction of replacement animals into the flock, the presence of older farmers, an inadequate brucellosis vaccination programme and higher flock seroprevalence in the town in 1997 were positively associated with case flocks. Thus, specific actions directed at farms presenting these characteristics should be included within official eradication programmes. In addition, for the 1999 campaign the time from sampling to culling the seropositive animals correlated positively (r=0·53; P<0·01) with the flock seroprevalence the following year, suggesting the need for a faster removal of the infected animals to increase the efficacy of the eradication campaigns.
Estimation of the basic reproduction ratio (R0) for Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) in beef calves
Authors: LAEGREID W. W. , KEEN J. E.
Published: February 2004

To understand the dynamics of transmission of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) in beef calves, serum samples were obtained from calves in a beef cow-calf herd approximately every 6 weeks from birth until weaning for three consecutive years. The presence of specific anti-O157 antibodies in these serum samples was detected using a blocking ELISA assay incorporating an anti-O157 monoclonal antibody. Using seroconversion data, the basic reproduction ratio (R0) was estimated for each of the three years as well as in aggregate using both deterministic and Martingale methods. R0 for STEC O157 infection in range beef calves by deterministic methods varied from 2·9–5·6, with an average of 4·3 (95% CI 2·8–5·9). Martingale estimates of R0 ranged from 3·5–7·4, or 5·3 (95% CI 3·9–6·6), for data from all three years. Given the above estimate of R0, it is predicted that 65–86% of a herd of calves must be effectively vaccinated, or must be rendered non-susceptible through other means, to eliminate STEC O157 infection from a herd.
Descriptive study of an avian pox outbreak in wild red-legged partridges (Alectoris rufa) in Spain
Authors: BUENESTADO F. , GORTÁZAR C. , MILLÁN J. , HÖFLE U. , VILLAFUERTE R.
Published: February 2004

This study describes the dynamics and epidemiology of an outbreak of avian pox in free-living, red-legged partridges (Alectoris rufa) in southern Spain. Between March 2000 and January 2001, 115 free-living, red-legged partridges (70 juveniles, 45 adults) were captured and radio-tagged. This, together with the necropsy of 44 carcasses (10 juveniles, 34 adults) found in the study area, and the inspection of 108 shot birds (74 juveniles, 34 adults) after a hunting drive in October, permitted a close monitoring of the course of the disease. Forty-one per cent of radio-tagged juveniles but none of 45 radio-tagged adults showed pox-like lesions at the time of capture, recapture, or necropsy. At least 40% of the juveniles that survived into the hunting season, but only 2·9% of the adults inspected at the same time, showed lesions suggestive of infection with avian poxvirus. The survival of juveniles during the peak of the outbreak was much lower than that of the adults, but we found no significant differences between the survival probabilities of juvenile partridges with and without pox-like lesions. Nevertheless, some birds may have developed lesions after their capture. The occurrence and course of the disease in a managed area with intense predator control underlines the need for studies on the combined influence of diseases and predators on population dynamics. Also the need for early detection of diseases for the management of game species is emphasized.
Prevalence of Streptococcus pneumoniae and Staphylococcus aureus nasopharyngeal colonization in healthy children in the United States
Authors: IMMERGLUCK L. CHENG , KANUNGO S. , SCHWARTZ A. , McINTYRE A. , SCHRECKENBERGER P. C. , DIAZ P. S.
Published: February 2004

This study documents the colonization of Staphylococcus aureus (SA), Streptococcus pneumoniae (SP) and specific resistant forms of these organisms among healthy children and identifies risk factors associated with these pathogens. Prospective point prevalence survey of nasopharyngeal specimens were obtained from 291 healthy children seeking routine well-child care at a university-based ambulatory paediatric clinic in a large urban city in the United States. A total of 291 children less than 5 years were enrolled during a 1-year period. Fifty-four (18·6%) were colonized with SA and 47 (16·2%) were colonized with SP. Among the 54 SA isolates, five (9·2%) were methicillin resistant (MRSA) and among the SP isolates, three (6·4%) were intermediate to penicillin (DRSP). Eighty per cent of all children enrolled reported no underlying medical condition. Care outside their home was more common among colonized (40·8%, 40/98) than non-colonized children (25·4%, 49/193), P=0·007. Healthy children from households of four or more people were also more likely to be colonized. The colonization rate of SA and SP among healthy children is consistent with what has been reported in the literature. The prevalence of MRSA and DRSP among healthy children colonized with SA or SP is low in this population of children attending a university-based ambulatory care centre in the United States.
Faecal contamination indicators, salmonella, vibrio and aeromonas in water used for the irrigation of agricultural products
Authors: PIANETTI A. , SABATINI L. , BRUSCOLINI F. , CHIAVERINI F. , CECCHETTI G.
Published: February 2004

The faecal contamination indicators (total coliforms, faecal coliforms, Escherichia coli, enterococci) and the genera Salmonella, Vibrio, Aeromonas were investigated in water samples used for irrigation. During 4 months, 52 samples were taken. The methods used were: multiple tube fermentation method for faecal contamination indicators and membrane filtration techniques for salmonella, aeromonas and vibrio. Two samples were positive for Salmonella spp., fourteen for Aeromonas spp. and no samples for Vibrio spp. No correlation was found between aeromonas and the indicators of faecal contamination. Regarding Aeromonas spp., 21·6% of the strains were adhesive and 12·6% cytotoxic: this confirms the possible role of aeromonas in human pathologies. These results are important to determine the quality of irrigation water in relation to human health. In fact, the spray or sprinkler irrigation produces bioaerosol, which can contaminate the crops that are likely to be eaten uncooked. In addition, the flood or furrow irrigation represents a risk to field workers.
Association between environmental risk factors and campylobacter infections in Sweden
Authors: NYGÅRD K. , ANDERSSON Y. , RØTTINGEN J. A. , SVENSSON Å. , LINDBÄCK J. , KISTEMANN T. , GIESECKE J.
Published: February 2004

Campylobacter sp. is the most common cause of acute bacterial gastroenteritis in Sweden and the incidence has been increasing. Case-control studies to identify risk factors have been conducted in several countries, but much remains unexplained. The geographical distribution of campylobacter infections varies substantially, and many environmental factors may influence the observed pattern. Geographical Information Systems (GIS) offer an opportunity to use routinely available surveillance data to explore associations between potential environmental risk factors showing a geographical pattern and disease incidence, complementing traditional approaches for investigating risk factors for disease. We investigated associations between campylobacter incidence and environmental factors related to water and livestock in Sweden. Poisson regression was used to estimate the strength of the associations. Positive associations were found between campylobacter incidence and average water-pipe length per person, ruminant density, and a negative association with the percentage of the population receiving water from a public water supply. This indicates that drinking water and contamination from livestock may be important factors in explaining sporadic human campylobacteriosis in Sweden, and that contamination occurring in the water distribution system might be more important than previously considered.
An epidemic of rotavirus diarrhoea in Jawhar Taluk, Thane district, Maharashtra, India, December 2000–January 2001
Authors: KELKAR S. D. , RAY P. G. , SHINDE N.
Published: February 2004

An epidemic of diarrhoea in Jawhar, a tribal area of Thane district, Maharashtra, India was investigated. Within a period of approximately 2 months 490 cases of acute diarrhoea were reported among children under 5 years of age, with a case fatality rate of 0·40%. Twenty-seven out of 39 (69·23%) rectal swabs/faecal specimens obtained from hospitalized paediatric patients up to 2 years of age from Jawhar were positive by ELISA for rotavirus. Of these, seven were in the age group of [les ]6 months. Seven ELISA-positive faecal specimens were positive for serotype G3 by RT–PCR. Out of 15 serum samples collected from these patients, 12 showed the presence of rotavirus-specific IgM. Rotavirus appears to be the aetiological agent of this widespread outbreak in Jawhar, Thane district, Maharashtra state, India.
Antibiotic resistance in Salmonella enterica serotypes Typhimurium, Enteritidis and Infantis from human infections, foodstuffs and farm animals in Italy
Authors: BUSANI L. , GRAZIANI C. , BATTISTI A. , FRANCO A. , RICCI A. , VIO D. , DIGIANNATALE E. , PATERLINI F. , D'INCAU M. , OWCZAREK S. , CAPRIOLI A. , LUZZI I.
Published: February 2004

The antimicrobial susceptibility of isolates of Salmonella enterica serotypes Typhimurium, Enteritidis, and Infantis isolated from humans, foodstuffs and farm animals in Italy between 1999 and 2001 was examined. All the isolates were susceptible to cefotaxime and ciprofloxacin, but high rates of resistance were observed for several other drugs, especially for S. Typhimurium. The rates of resistance and multiresistance were generally higher among animal and food isolates than in human strains; conversely, no significant difference was observed between animal and food isolates. Among S. Typhimurium, multiresistance was more common in bovine, poultry and rabbit strains than in swine isolates, and was rare in strains from pigeon. Resistance to trimethoprim–sulphamethoxazole was mainly found in isolates of swine and human origin. This study confirms the role of livestock as a reservoir of drug-resistant Salmonella spp. and underlines the need for integrated surveillance systems of antibiotic resistance that consider isolates not only from human disease but also from the animal reservoirs and the food vehicles.
Abundance, diversity, and community patterns of Isopoda (Crustacea) in the Weddell Sea and in the Bransfield Strait, Southern Ocean
Authors: BRANDT ANGELIKA
Published: February 2004

Abundance, diversity, and distribution of suprabenthic Isopoda caught from a water layer between 0.27 to 0.60 m above the seafloor were analysed. The samples were taken during the ANT XV/3 cruise on RV Polarstern by means of an epibenthic sledge along two transects in the southern Weddell Sea (Vestkapp and Halley Bay) and another one east of King George Island. At each of these three bathymetric transects, five to six stations were sampled between 200 and 2000 m. In total, 4258 specimens of isopods were sampled at 14 stations standardized to 1000 m2 hauls. 114 species were identified from 49 genera and 23 higher taxa (families and suborders) of Isopoda. Most of them belonged to the suborder Asellota. Dominant families are Munnopsididae (Eurycopinae, Ilyarachninae), Joeropsidae, Munnidae, Paramunnidae, Ischnomesidae and Desmosomatidae. No striking differences were found between areas (Vestkapp, Halley Bay, Kapp Norvegia, and Bransfield Strait). Overall isopod abundances were highest at the shallowest station; species richness was slightly higher above 1000 m depth.
Genome dynamics and chromosomal localization of the non-LTR retrotransposons Rex1 and Rex3 in Antarctic fish
Authors: OZOUF-COSTAZ CATHERINE , BRANDT JÜRGEN , KÖRTING CORNELIA , PISANO EVA , BONILLO CÉLINE , COUTANCEAU JEAN-PIERRE , VOLFF JEAN-NICOLAS
Published: February 2004

The non-long terminal repeat retrotransposons Rex1 and Rex3 were identified in 13 species of Antarctic fishes from five families of the suborder Notothenioidei. Partial reverse transcriptase gene sequences were characterized for Notothenia coriiceps, Trematomus newnesi and Dissostichus mawsoni (Nototheniidae), and Gymnodraco acuticeps (Bathydraconidae). Rex1 and Rex3 both formed a notothenioid-specific monophyletic group compared to the corresponding elements from other fishes. They globally evolved under purifying selection, showing their activity during notothenioid evolution. Fluorescence in situ hybridization analysis of the chromosomal distribution of Rex1 and Rex3 was performed for several notothenioid fish species. Rex1 was generally less abundant than Rex3, which was widely scattered on the chromosomes with more intense hybridization patterns in some specific zones. Particularly, Rex3 accumulated in Chionodraco hamatus in pericentromeric areas, short arms of some pairs as well as in an intercalary band in the long arm of the Y chromosome similarly to a previously described DNA transposon. Such pattern similarities suggest the presence of autosomal and gonosomal regions of preferential accumulation for different types of repeated elements in notothenioid genomes. To the best of our knowledge, this report is the first description and analysis of retrotransposable elements in Antarctic fish genomes.
Comparison of Arctic and Antarctic teleost haemoglobins: primary structure, function and phytogeny
Authors: VERDE CINZIA , PARISI ELIO , DI PRISCO GUIDO
Published: February 2004

Organisms living in the Arctic and Antarctic are exposed to strong environmental constraints, especially temperature. Consequently, haemoglobin evolution has included adaptations with implications at the biochemical, physiological and molecular levels. The northern and southern polar oceans have very different oceanographic characteristics. Within the study of the molecular bases of cold adaptation in fish inhabiting polar habitats, and taking advantage of the information available on haemoglobin structure and function, we analysed the evolutionary history of the α and β globins of Antarctic and Arctic haemoglobins, under the assumption of the molecular-clock hypothesis, as a basis for reconstructing the phylogenetic relationships between species. Temperate fish, including two non-Antarctic notothenioids of special evolutionary interest, were also considered. Phylogenetic analysis was performed on the multiple sequence alignments constructed with the programme Clustal X. Tree topologies indicate that the chains of Antarctic major and minor haemoglobins cluster in two well separated groups and diverged prior to cold adaptation, forming a monophyletic group. In Arctic haemoglobins, the structure/function relationship reveals important differences in comparison with Antarctic ones, indicating a distinct evolutionary pathway. The Arctic ichthyofauna (unlike the Antarctic, dominated by one taxonomically uniform group) is characterized by high diversity, reflected in the phylogeny of a given trait. The constant physico-chemical conditions of the Antarctic waters are matched by a clear grouping of fish globin sequences, whereas the variability typical of the Arctic Ocean corresponds to high sequence variation, reflected in the trees by scattered intermediate positions between the Antarctic and non-Antarctic clades. The evolutionary history of the Root effect, an important physiological feature of fish haemoglobin, was investigated. Analysis of the fate of the residues of the β chains suggested to be correlated with the Root effect indicate that they should rather be regarded as ancestral characters, inherited by some species but not by others.
Molecular pathogenesis of chronic myeloid leukaemia
Authors: Smith Duncan L. , Burthem John , Whetton Anthony D.
Published: February 2004

The abnormal haemopoietic precursor cells of chronic myeloid leukaemia (CML) carry the cytogenetic abnormality [t(9;22)(q34;q11)] – a reciprocal translocation that results in the expression of a chimaeric protein derived from the fused BCR and ABL genes. This Bcr–Abl protein tyrosine kinase mediates an array of effects on signal transduction pathways affecting cell survival, proliferation, adhesion and genetic stability. The end-result of these abnormal signalling processes is a bi- or triphasic clinical disease. Initially, CML is characterised by the presence of an excess of myeloid progenitor cells and their mature progeny. This chronic phase of CML is followed, either directly or with an intervening ‘accelerated phase’, by a stage where primitive blast cells predominate (acute transformation). This review discusses the role of Bcr–Abl-mediated signalling events in cellular transformation, genetic instability and disease progression in CML, and describes current developments in CML treatment using a Bcr–Abl inhibitor.
Hepatocellular carcinoma: molecular interactions between hepatitis C virus and p53 in hepatocarcinogenesis
Authors: Anzola Mónica , Burgos Juan José
Published: February 2004

Hepatocellular carcinoma (HCC) is the most important primary hepatic cancer and is a common cancer type worldwide. Many aetiological factors have been related to HCC development, such as liver cirrhosis, hepatitis viruses and alcohol consumption. Inactivation of the p53 tumour suppressor gene is one of the most common abnormalities in many tumours, including HCC. p53 is of crucial importance for the regulation of the cell cycle and the maintenance of genomic integrity. In HCC, hepatitis B and C virus (HBV and HCV) effect carcinogenic pathways, independently leading to anomalies in p53 function. Several authors have reported that some HCV proteins, such as the core, NS5A and NS3 proteins, interact with p53 and prevent its correct function. The mechanisms of action of these HCV proteins in relation to p53 are not completely clear, but they might cause its cytoplasmic retention or accumulation in the perinuclear region where the protein is not functional. The identification of the interactions between p53 and HCV proteins is of great importance for therapeutic strategies aimed at reducing the chronicity and/or carcinogenicity of the virus.
Novel concepts in excitotoxic neurodegeneration after stroke
Authors: Aarts Michelle M. , Arundine Mark , Tymianski Michael
Published: February 2004

Brain injury following cerebral ischaemia (stroke) involves a complex combination of pathological processes, including excitotoxicity and inflammation leading to necrotic and apoptotic forms of cell death. At the cellular level, excitotoxicity is mediated by glutamate and its cognate receptors, resulting in increased intracellular calcium and free radical production, and eventual cell death. Recent evidence suggests that scaffolding molecules that associate with glutamate receptors at the postsynaptic density allow coupling of receptor activity to specific second messengers capable of mediating excitotoxicity. These findings have important implications in the search for effective neuroprotective therapies in treating stroke.
SH2 domains: role, structure and implications for molecular medicine
Authors: Waksman Gabriel , Kumaran Sangaralingam , Lubman Olga
Published: February 2004

Src homology 2 (SH2) domains are protein modules (of ~100 amino acids) found in many proteins involved in tyrosine kinase signalling cascades. Their function is to bind tyrosine-phosphorylated sequences in specific protein targets. Binding of an SH2 domain to its cognate tyrosine-phosphorylated target links receptor activation to downstream signalling, both to the nucleus to regulate gene expression and throughout the cytoplasm of the cell. This review recapitulates the roles that SH2 domains play in normal and diseased states, describes the successes of SH2 domain research in deciphering their mechanism of action, and provides an overview of the use of SH2 domains as structural templates for the design of inhibitor drugs.
The two‐step Forbush decrease: An empirical model
Authors: Ifedili S. O.
Published: February 2004

The cosmic ray decreases and interplanetary disturbances observed at 1 AU have been investigated by using some cosmic ray hourly intensities recorded with ground‐based monitors at Alert, Deep River, and Mount Washington as well as the interplanetary magnetic field (IMF) and the solar wind plasma bulk speed, density, and temperature in the near‐Earth space. We studied a two‐step Forbush decrease (FD)‐type, with large cosmic ray intensity decreases, on 29–30 September 1978, 24–26 April 1979, 27–28 August 1978, 30 January 1978, 13–15 January 1967, 3–5 January 1978, 28–29 November 1989, and 29–30 December 1989, each of which appears to be produced by the structure within the shock and sheath preceding the interplanetary coronal mass ejection (ICME). There is a sheath upstream of the ICME led by a fast forward shock. The sheath material is slow solar wind that has been swept up by the ICME and is not part of the ICME itself. The sheath material is hot, dense, and turbulent and is most probably produced by the shock. The large IMF variations in the shocked plasma scatter the galactic cosmic rays and thus sweep away the cosmic ray particles. When the IMF variations in the sheath become too feeble (the lull region), the scattering of the galactic cosmic rays ceases, corresponding to the recovery phase of the first step of the FD; the particle scattering resumes when the high IMF variations in the sheath resume and the onset of the second decrease starts. There is a second and rear region inside the interplanetary macrostructure, the ICME/magnetic cloud, where the galactic cosmic rays are also scattered away from the high magnetic field pressure in the magnetic cloud. A data set with fine time resolution (less than an hour) and good statistics is needed to provide an exact timing of the various phenomena.
Analytical and numerical solutions for alternative overpressuring processes: Application to the Callovo‐Oxfordian sedimentary sequence in the Paris basin, France
Authors: Gonçalvès Julio , Violette Sophie , Wendling Jacques
Published: February 2004

Previous studies that made use of basin models have shown that the normal geological evolution of the Paris basin does not generate the observed, albeit weak, excess pressures in some shale layers of the basin. Other processes that may have created the overpressures, currently neglected in such models, are investigated here. Terms accounting for osmotic effects and tectonic stress changes are successively added to the diffusivity equation. The effect of changes in outcrop boundary conditions is also calculated with a pseudo‐two‐dimensional analytical solution. These solutions are applied to the Callovo‐Oxfordian shale formation in the eastern part of the Paris basin, France. It is shown that a long‐term transient osmotic effect starting in the Tertiary could explain in part the observed excess pressures in the Callovo‐Oxfordian shale assuming effective diffusion coefficients of 1–5 × 10−12 m2 s−1 in line with the measurements and a pore radius b around 20 Å for the shales. However, because of the uncertainty on the value of the shale pore radius, additional head measurements and osmotic experiments on samples should be made to fully establish the possibility of an osmotic process. Our study also shows that recent changes in hydrodynamic boundary conditions could also explain excess pressure distribution in this shale layer. It is plausible that a combination of the two processes could best explain the distribution and intensity of the “overpressures.” Tectonic stress changes do not appear to be important; it is shown that for such processes, to maintain high pressures, strong and recent increase in tectonic compressive stress would be required.
Seasonal to interannual variability of the eddy field in the Labrador Sea from satellite altimetry
Authors: Brandt Peter , Schott Friedrich A. , Funk Andreas , Martins Carlos S.
Published: February 2004

Sea level anomalies measured by the altimeters aboard the TOPEX/Poseidon and ERS satellites for the periods 1993–2001 and 1997–2001, respectively, are used to investigate the eddy field in the subpolar North Atlantic and in the Labrador Sea. A quadratic correction of the obtained eddy kinetic energy (EKE) with respect to significant wave height is applied that led to an increased correlation between moored and altimetric EKE in the central Labrador Sea. The mean EKE field shows higher levels associated with the main currents and a strong seasonality in the Labrador Sea. The annual cycle of the EKE shows a propagation of West Greenland Current (WGC) EKE into the central Labrador Sea with a mean southward propagation speed of about 3 cm s−1, while the EKE maximum in the Labrador Current is well separated from the interior by local EKE minima. The interannual variability of the EKE in the Labrador Sea shows distinct regional differences. In the WGC region, strong early winter maxima are found during 1993 and 1997–1999. In the central Labrador Sea, maxima are found during March/April 1993–1995 and 1997. Variations in the annual cycle of the WGC EKE are observed: While there is a weak annual cycle in the WGC region during 1994–1996 with more continuous EKE generation, during 1997–2000, there is a strong seasonal cycle with maximum EKE during January and particularly low EKE during summer. The propagation of WGC EKE into the central Labrador Sea is enhanced during 1997–2000, leading to a long persistence of EKE in the central Labrador Sea. During 1993–1995 and 1997 the central Labrador Sea EKE almost instantaneously increased during March/April, followed, in the earlier years, by a relatively fast destruction of the winterly generated EKE.
Concentration of crustal displacement along a weak Altyn Tagh fault: Evidence from paleomagnetism of the northern Tibetan Plateau
Authors: Dupont‐Nivet Guillaume , Robinson Delores , Butler Robert F. , Yin An , Melosh H. Jay
Published: February 2004

Like many regional structures in the northern Tibetan Plateau, the Tula syncline changes strike by ∼40° from NW‐SE to nearly EW as it approaches the Altyn Tagh fault from the south. To test whether this strike curvature is due to oroclinal bending, we analyzed paleomagnetic samples from 109 sites collected from Late Jurassic to Paleogene red sedimentary strata of the Tula syncline. Fold and reversal tests suggest a primary origin for the characteristic remanent magnetization from nine sites in the eastern half and 41 sites in the western half of the syncline. The observed 13.3°±8.8° declination difference between the two halves of the Tula syncline is far less than the ∼40° difference predicted for oroclinal bending. Instead the arc shape of the syncline is an original configuration produced by transport above an arcuate thrust ramp. Along with paleomagnetic data from the northern Qaidam Basin, these results from the Tula syncline indicate that crustal displacement between the Tarim Basin and the northern Tibetan Plateau is accommodated by strike‐slip motion on the Altyn Tagh fault rather than distributed shear within the northern Tibetan Plateau.
Seasonal variation of auroral electron precipitation
Authors: Barth C. A. , Baker D. N. , Bailey S. M.
Published: February 2004

Global observations of nitric oxide obtained from the Student Nitric Oxide Explorer (SNOE) have been used to determine the density of nitric oxide in the lower thermosphere. A thermospheric model which takes into account all of the photochemical processes that produce and destroy nitric oxide has been used to deduce the flux of precipitating auroral electrons that produce nitric oxide. The results of this analysis allow us to infer the daily variability of precipitating electron energy deposition. The most important result of this paper is that there is a clear‐cut minimum in the electron flux at the time of the summer solstice in both hemispheres. This seasonal dependence of precipitating auroral electrons supports the idea that auroral arcs are suppressed in the solar‐illuminated hemisphere due to high ionospheric conductivity. The strength of the seasonal variations suggests that the bulk of the energy deposition may be due to discrete auroral events.
Energetic ion composition in Saturn's magnetosphere revisited
Authors: Paranicas C. , Decker R. B. , Mauk B. H. , Krimigis S. M. , Armstrong T. P. , Jurac S.
Published: February 2004

We present a new analysis of the composition of energetic charged particles in Saturn's inner magnetosphere. This analysis is motivated by a discovery made after the Voyager 1 and 2 Saturn encounters of penetrating electrons in some total ion measurement channels of the Low Energy Charged Particle detectors. From this new analysis, we predict that there is no significant increase in the ratio of heavy energetic ions to protons inward of the orbit of the satellite Dione, as previously thought. This implies that energetic ion sputtering of the icy rings and satellites produces much less water vapor than has been assumed based on past composition estimates. For protons between about 500 keV and a few MeV, we observe a decrease in measured flux inward of about L = 6 and suggest the cause of this decrease is not well understood.
Seasonal variation of lightning on the Tibetan Plateau: A Spring anomaly?
Authors: Toumi Ralf , Qie Xiushu
Published: February 2004

Satellite observations of lightning over the Tibetan Plateau show a maximum flash density in July. Thermodynamic parameters and rainfall obtained from meteorological reanalysis are broadly consistent with the observed seasonal cycle. However, there is more lightning in Spring than one may expect from a simple relationship with rainfall, temperature or cloud buoyancy. The surface total heat flux best accounts for the seasonal variation of lightning including the Spring lightning. The cloud buoyancy and rainfall show a better seasonal relationship when they are multiplied by the ratio of the sensible to latent heat flux (the Bowen ratio). This suggests an important role, at least in the Tibetan Plateau, for the sensible heat flux in modifying the efficiency of generating lightning from cloud buoyancy.
Characteristic of subionospheric VLF perturbations associated with winter lightning around Japan
Authors: Otsuyama T. , Manabe J. , Hayakawa M. , Nishimura M.
Published: February 2004

The VLF signature of ionospheric perturbations (Trimpis) associated with winter lightning around Japan has been investigated during a three‐month observation (December 2000 to February 2001). The absence of observed optical phenomena (mesospheric optical emissions such as sprites) in the Hokuriku area (Sea of Japan side) indicates that the period was not extremely active in lightning as compared with the previous winter [Hobara et al., 2001]. Based on VLF subionospheric observation at Moshiri (Hokkaido) and Maizuru (near Kyoto) for two VLF transmitter signals (NWC (Australia) and NPM (Hawaii)), we have found the following; (1) Lightning discharges are found not only on the Japan‐Sea side, but also on the Pacific side. Although more lightning was observed on the Pacific side of Japan, the Trimpi occurrence rate is more enhanced over the Sea of Japan. (2) Trimpis tend to occur only when the lightning activity is enhanced. (3) Trimpi occurrence rate shows no particular diurnal variation. (4) There is no significant difference in the Trimpi occurrence rate between + and − CG discharges. (5) The intensity of scattered signal (with respect to the unperturbed wave) is, in most case, ranging from −15 to −25 dB. These characteristics are discussed in terms of meteorological and lightning conditions.
Automated cloud screening algorithm for MFRSR data
Authors: Alexandrov Mikhail D. , Marshak Alexander , Cairns Brian , Lacis Andrew A. , Carlson Barbara E.
Published: February 2004

A new automated cloud screening algorithm for ground‐based sun‐photometric measurements is described and illustrated on examples of real (MFRSR) and simulated data. The algorithm uses single channel direct beam measurements and is based on variability analysis of retrieved optical thickness. To quantify this variability the inhomogeneity parameter ε is used. This parameter is commonly used for cloud remote sensing and modeling, but not for cloud screening. In addition to this an adjustable enveloping technique is applied to control strictness of the selection method. The key advantages of this technique are its objectivity, computational efficiency and the ability to detect short clear‐sky intervals under broken cloud cover conditions. Moreover, it does not require any knowledge of the instrument calibration. The performance of the method has been compared with that of AERONET cloud screening algorithm.