Comparison of Edwardsiella ictaluri isolates from different hosts and geographic origins.

The intraspecific variability of E. ictaluri isolates from different origins was investigated. Isolates were recovered from farm-raised catfish (Ictalurus punctatus) in Mississippi, USA, tilapia (Oreochromis niloticus) cultured in the Western Hemisphere and zebrafish (Danio rerio) propagated in Florida, USA. These isolates were phenotypically homologous and antimicrobial profiles were largely similar. Genetically, isolates possessed differences that could be exploited by repetitive-sequence-mediated PCR and gyrB sequence, which identified three distinct E. ictaluri genotypes: one associated with catfish, one from tilapia and a third from zebrafish. Plasmid profiles were also group specific and correlated with rep-PCR and gyrB sequences. The catfish isolates possessed profiles typical of those described for E. ictaluri isolates; however, plasmids from the zebrafish and tilapia isolates differed in both composition and arrangement. Furthermore, some zebrafish and tilapia isolates were PCR negative for several E. ictaluri virulence factors. Isolates were serologically heterogenous, as serum from a channel catfish exposed to a catfish isolate had reduced antibody activity to tilapia and zebrafish isolates. This work identifies three genetically distinct strains of E. ictaluri from different origins using rep-PCR, 16S, gyrB and plasmid sequencing, in addition to antimicrobial and serological profiling.

Correction of the spectral calibration of the Joint European Torus core light detecting and ranging Thomson scattering diagnostic using ray tracing.

This work isolated the cause of the observed discrepancy between the electron temperature (T(e)) measurements before and after the JET Core LIDAR Thomson Scattering (TS) diagnostic was upgraded. In the upgrade process, stray light filters positioned just before the detectors were removed from the system. Modelling showed that the shift imposed on the stray light filters transmission functions due to the variations in the incidence angles of the collected photons impacted plasma measurements. To correct for this identified source of error, correction factors were developed using ray tracing models for the calibration and operational states of the diagnostic. The application of these correction factors resulted in an increase in the observed T(e), resulting in the partial if not complete removal of the observed discrepancy in the measured T(e) between the JET core LIDAR TS diagnostic, High Resolution Thomson Scattering, and the Electron Cyclotron Emission diagnostics.

Primary diagnosis and surveillance of white spot syndrome virus in wild and farmed crawfish (Procambarus clarkii, P. zonangulus) in Louisiana, USA.

This is the first report of natural white spot syndrome virus (WSSV) infection in wild and large-scale farmed crawfish. In the spring of 2007, 3 crawfish farms experienced heavy mortality in ponds populated by Procambarus clarkii and P. zonangulus. Histological examination revealed findings consistent with severe viral infection characterized by numerous intranuclear inclusions in ectodermal and mesodermal tissues. Samples tested by in situ hybridization, injection bioassay in Litopenaeus vannamei, and PCR (nested and real time) were all positive for WSSV. Samples were sent to the National Veterinary Services Laboratory in Ames, Iowa, USA, where WSSV was verified. Subsequently, a multi-parish survey of 184 sites in Louisiana (including farm and wild basin samples) using real-time PCR determined that >60% of sites sampled were positive for WSSV, including wild basin samples.

Francisella sp., an emerging pathogen of tilapia, Oreochromis niloticus (L.), in Costa Rica.

Francisella sp. is an emergent bacterial pathogen that causes acute to chronic disease in warm and cold water cultured and wild fish species. During the past 3 years, the bacterium has been detected in tilapia, Oreochromis niloticus, cultured in Costa Rica. Infected fish presented non-specific clinical signs, such as erratic swimming, anorexia, anaemia, exophthalmia and high mortality. Upon macroscopic and microscopic examination, several internal organs (mainly spleen and kidney) were enlarged and contained white nodules. Histological examination revealed the presence of multifocal granulomatous lesions, with the presence of numerous small, pleomorphic, cocco-bacilli. The bacteria were isolated from infected tilapia on selective media and grown on several media with and without antibiotics. Specific PCR primers to the Francisella genus were used to confirm the preliminary diagnoses. In comparison with several bacterial 16S rRNA sequences, our isolate was found to share 99% identity with other Fransicella spp. isolated from fish, and more than 97% identity to the human pathogen Francisella tularensis. Koch's postulates were fulfilled after experimental intraperitoneal and gill exposure challenges.

A piscirickettsiosis-like syndrome in cultured Nile tilapia in Latin America with Francisella spp. as the pathogenic agent.

In 2004, cultured Nile tilapia Oreochromis niloticus in several Latin America farms began to succumb to a disease similar to the piscirickettsiosis-like syndrome previously reported in tilapia in Taiwan and the United States. Mortality increased during 2005; reductions in tilapia biomass ranged from 5% to 80% in individual ponds and averaged 50% overall. All ages of fish have been involved. Clinical signs include lethargy, loss of appetite, petechia, exophthalmia, and abnormal swimming behavior. Gross lesions have included splenomegaly, renomegaly, and numerous white nodules observed in the spleen, kidney, testes, heart, ovaries, and occasionally the liver. A previously unreported black granulomatous lesion was reported in up to 30% of the fillets. Histologically, granulomatous infiltrates were observed in the kidney, spleen, liver, testes, ovary, and choroid gland, and rarely in the brain and heart. A small pleomorphic bacterium was observed in Giemsa-stained blood smears and spleen imprints. The bacterium did not grow on standard microbiological media and has not been isolated in cell culture. We obtained a near-complete 16S ribosomal DNA sequence with high similarity to Francisella spp. sequences previously identified in tilapias Oreochromis spp. (Taiwan), Atlantic cod Gadus morhua (Norway), and three-line grunts Parapristipoma trilineatum (Japan).

Antimicrobial susceptibility testing of aquatic bacteria: quality control disk diffusion ranges for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28 degrees C.

Quality control (QC) ranges for disk diffusion susceptibility testing of aquatic bacterial isolates were proposed as a result of a multilaboratory study conducted according to procedures established by the National Committee for Clinical Laboratory Standards (NCCLS). Ranges were proposed for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28 degrees C for nine different antimicrobial agents (ampicillin, enrofloxacin, erythromycin, florfenicol, gentamicin, oxolinic acid, oxytetracycline, ormetoprim-sulfadimethoxine, and trimethoprim-sulfamethoxazole). All tests were conducted on standard Mueller-Hinton agar. With >/=95% of all data points fitting within the proposed QC ranges, the results from this study comply with NCCLS guidelines and have been accepted by the NCCLS Subcommittee for Veterinary Antimicrobial Susceptibility Testing. These QC guidelines will permit greater accuracy in interpreting results and, for the first time, the ability to reliably compare susceptibility test data between aquatic animal disease diagnostic laboratories.

Gender, psychopathology, and patterns of homelessness among clients in shelter-based TCs.

UNLABELLED: Substance abuse and severe mental illness are factors that have been linked to homelessness, and the rates of mental illness have been reported to be higher among homeless women than men. Only recently have investigators begun to examine the prevalence of abuse among the homeless population and its relationship to indicators of psychopathology. This study builds on the existing literature and examines the relationship among psychiatric disturbance, abusive experiences, and homelessness among adult men and women admitted to shelter-based therapeutic community (TC) drug treatment programs. RESULTS: The sample presents with extensive psychopathology and a history of physical and sexual abuse. Gender differences indicate that, except for antisocial personality, females yield higher rates on measures of both psychiatric disturbance and abuse. The relationship between psychopathology and abuse also appears to be much stronger for females than for males. However, the relationship between abuse and adult homelessness appears to be similar for men and women. The gender differences in the relationship between histories of abuse and manifestations of psychiatric disturbance support a hypothesis that has been proposed elsewhere: Females internalize the trauma associated with abusive experience, while males externalize it. The findings suggest that, although there may be a need for gender-specific targeted interventions, treatment providers must also recognize that the impact of abuse seems to transcend gender within this population.

Adolescents in therapeutic communities: one-year posttreatment outcomes.

Given the dearth of information concerning outcomes for adolescents who have been in treatment for substance abuse and related problems, the purpose of the present article is to examine the posttreatment status of adolescents who have been in residential therapeutic communities (TCs). One-year posttreatment outcome data are described for 485 adolescents, and separately for treatment "completers" and "noncompleters." The majority of the sample had been mandated to treatment by the criminal justice system. Most reported marijuana as their main drug of abuse. There were significant reductions in drug use and criminal activity, and the most consistent predictors of positive outcomes were completion of treatment and not associating with deviant peers posttreatment. The findings were obtained on a treatment sample for whom there is relatively little research to date; they provide important evidence for the effectiveness of the therapeutic community for this population.

Adolescent amphetamine users in treatment: client profiles and treatment outcomes.

This study compares client profiles of adolescent amphetamine users to those of nonusers and examines the multivariate prediction of posttreatment drug use, criminal, and HIV risk behavior outcomes in the year following their separation from treatment. Data were collected as part of a larger longitudinal study on a sample of 938 adolescents who were admitted to residential therapeutic community drug treatment programs across the eastern United States and Canada from April of 1992 through April of 1994. A subsample of 485 adolescents were reinterviewed one year after their separation from treatment. Findings indicated that amphetamine users tended to be white, older, and have parents with higher education and occupational levels than nonusers. However, they also had more psychopathology, more extensive drug use and criminal histories, and engaged in more HIV-risk behaviors than nonusers. Additionally, amphetamine users tend to come from homes where one or both parents used illicit drugs, drank regularly, or had a mental illness, and they often reported histories of childhood maltreatment. Analyses of the one-year follow-up data indicated that being an amphetamine user was not related to treatment outcome after the client's demographic characteristics, overall drug use severity, and treatment completion were taken into account. Therefore, therapeutic community treatment appears to be an effective means of treating adolescent amphetamine users.

Therapeutic communities. Enhancing retention in treatment using "Senior Professor" staff.

Evaluation research documents a firm relationship between retention and treatment outcomes among substance abusers in therapeutic communities (TCs). However, most admissions leave treatment prematurely, particularly in the first months after admission. This paper reports findings from a controlled study that assessed the efficacy of an intervention to reduce early dropout in a residential TC. In the "Senior Professor" (SP) intervention, the most experienced clinical and managerial staff in a TC program were utilized to conduct program induction seminars during the first weeks of admissions, traditionally the period of the highest rate of dropout. Rates of short-term retention (30 days of treatment) were compared for the experimental cohort (N=362), who received the intervention, and a cohort of admissions (N=243), who received standard or non-enhanced treatment. Findings showed that the SP intervention significantly reduced the likelihood of early dropout compared with controls. The enhanced effects are most evident for the new inductees with the lowest levels of motivation. Some theoretical and clinical implications are discussed as to the utilization of experienced staff to increase retention among new inductees with relatively lower motivational levels, who are at greatest risk for early dropout.

Detection of human papillomavirus DNA in PUVA-associated non-melanoma skin cancers.

Psoralen and UVA (PUVA) photochemotherapy is associated with a dose-dependent increased risk of nonmelanoma skin cancer in patients treated for psoriasis. Like ultraviolet B radiation, PUVA is both mutagenic and immunosuppressive and may thus act as a complete carcinogen; however, the reversed squamous to basal cell carcinoma ratio (SCC:BCC) in PUVA-treated patients, also seen in immunosuppressed renal transplant recipients, suggests a possible cofactor role for human papillomavirus (HPV) infection. In this study we examine a large series of benign and malignant cutaneous lesions for the presence of HPV DNA from patients treated with high dose (> or =500 J per cm2) ultraviolet A. A panel of degenerate primers based on the L1 (major capsid protein) open reading frame was employed, designed to detect mucosal, cutaneous, and epidermodysplasia verruciformis HPV types with high sensitivity and specificity. HPV DNA was detected in 15 of 20 (75%) non-melanoma skin cancer, seven of 17 (41.2%) dysplastic PUVA keratoses, four of five (80%) skin warts, and four of 12 (33%) PUVA-exposed normal skin samples. The majority of HPV positive lesions contained epidermodysplasia verruciformis-related HPV including HPV-5, -20, -21, -23, -24, and -38. Possible novel epidermodysplasia verruciformis types were identified in further lesions. Mixed infection with epidermodysplasia verruciformis, cutaneous, and/or mucosal types was present in six of 30 (20%) of all HPV positive lesions, including in normal skin, warts, dysplastic PUVA keratoses, and squamous cell carcinomas. The prevalence and type of HPV infection in cutaneous lesions from PUVA-treated patients is similar to that previously reported in renal transplant-associated skin lesions, and suggests that the role of HPV in PUVA-associated carcinogenesis merits further study.

Motivation and readiness for therapeutic community treatment among adolescents and adult substance abusers.

A growing body of research has demonstrated the importance of motivation and readiness among drug abusers in seeking, complying with, and remaining in treatment. To date, however, there is little research on these factors among adolescent substance abusers. The present study reports findings from a large scale investigation of motivation and readiness differences across adolescent (range = 14-18 years, n > 1000) and adult (range = 19-26 + years, n > 1400) admissions to residential therapeutic communities (TCs). Data were collected with an instrument assessing circumstances, motivation, readiness, and suitability for TC treatment (i.e., CMRS). Results showed that: (1) there is a significant positive linear relationship between CMRS scores and age; (2) the CMRS scores were the largest and most consistent predictors of short term retention across all age groups. Although confined to TC samples, the present findings support clinical observations that adolescent drug abusers are less motivated to change or ready for treatment than adults; and they confirm the importance of motivational and readiness factors in the treatment process, regardless of age.

Immunization with bacterial antigens: edwardsiellosis.

Enteric septicaemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most serious disease affecting commercial catfish culture in the United States. ESC is generally an acute septicaemia that develops very quickly, especially in the temperature range of 22-28 degrees C, with a more chronic disease presentation outside this range. The ability of E. ictaluri to avoid the host's immune system and proliferate into a systemic infection is impressive. Catfish kidney tissue cultured positive for E. ictaluri as soon as 15 minutes following gastric lavage and signs of disease are observed microscopically within two days of immersion challenge, with reported mortalities as early as five days following immersion challenge. Analysis of E. ictaluri antigens by several investigators using SDS-PAGE and colorimetric western blotting with immune catfish has identified as many as 15 immunogenic bands. Analysis using two-dimensional SDS-PAGE and chemiluminescent western blotting identified 14 bands and 25 spots as consistently immunogenic. The strongest immunodominant antigens were reported as 34-37 KD and 60 KD, depending on the study. Lipopolysaccharide is the only purified component of E. ictaluri tested for fish vaccination, and results indicated that very poor protection was induced unless Freund's Complete Adjuvant was used. Because E. ictaluri strains are serologically homogeneous, most studies on vaccination have emphasized killed whole cell preparations and have delivered equivocal results. Although antibodies are produced to a variety of preparations, a positive antibody response does not correlate with protection unless very high titres are achieved. Efficacy of killed products has been demonstrated in field trials, and an orally delivered product has been licensed. However, protection probably relies on booster exposure of the host to E. ictaluri during non-permissive temperatures. As a facultative intracellular pathogen, further studies on vaccination of catfish against E. ictaluri should target products and delivery methods that favour induction of cell mediated immunity.

Acetyl coenzyme A carboxylase in species of Triticum of different ploidy.

The cellular amounts and cellular activities of acetyl CoA carboxylase (ACC; EC 6.4.1.2.) were determined in the first leaves of diploid, tetraploid and hexaploid species of Triticum (wheat). Per leaf the ACC activities were very similar in T. monococcum (2 χ), T. dicoccum (4 χ) and T. aestivum (6 χ). The ACC activity per chloroplast also showed little variation between species of different ploidy but since chloroplast number increases with ploidy, the ACC activities and ACC amounts per cell also increased with ploidy. These cellular increases in ACC amounts associated with increases in gene dosage were highly co-ordinated in the diploids T. monococcum and T. tauschii and their respective autotetraploids so the specific activity of ACC was highly conserved in these plants. The relevance of these findings to attempts to genetically manipulate lipid biosynthesis in chloroplasts is discussed.

Acetyl-CoA-carboxylase activity in normally developing wheat leaves.

In order to investigate the role of acetyl CoA carboxylase (ACC) in the regulation of fatty-acid biosynthesis in chloroplasts, the activities and relative amounts of the enzyme have been measured in the tissue of wheat (Triticum aestivum L.) leaves undergoing development and cellular differentiation. The total activity in the first leaves of 5- to 7-d-old plants was similar but decreased to less than half in 9-d-old plants. The activity of ACC in the cells of the first leaf of 7-d-old plants doubled when cell age increased from 24 to 48 h, remained relatively constant for a further 24 h and then declined. The amount of ACC in cells increased 15-fold during the first 36 h of cell enlargement. Cells more than 36 h old contained about two-thirds the maximum amount of ACC found in younger cells. The most rapid phase of fatty-acyl accumulation in lipids was in cells aged between 60 and 84 h. Tenfold changes in the activity of ACC were observed when the assay conditions with respect to ATP, ADP, Mg(2+) and pH were changed to correspond to the physiological conditions in chloroplasts during light/dark transitions. This observation and the magnitude of the changes in the optimum activity and amount of ACC in leaf cells undergoing development are consistent with a role for ACC in the regulation of the flow of carbon from acetyl CoA to fatty acids in chloroplasts.

Purification and characterization of maize leaf acetyl-coenzyme A carboxylase.

Maize leaf acetyl-CoA carboxylase was purified from whole tissue homogenates by precipitation with polyethylene glycol and ammonium sulfate, and gel filtration. Recoveries were approximately 5% with 100-fold increases in specific activity. The molecular weight of the native enzyme is estimated at 500,000 from the elution volume of a calibrated Ultrogel AcA 22 column. Electrophoresis in polyacrylamide gel containing 1% sodium dodecyl sulfate revealed a single subunit of Mr 60,000-61,000. Investigation of the kinetic properties of the purified enzyme indicates that Mg X ATP is the active substrate, with free ATP inhibiting and Mg2+ activating the enzyme. Km's for acetyl-CoA and HCO3- are about 0.1 and 2 mM, respectively. ADP inhibition is competitive with respect to ATP, but uncompetitive with respect to acetyl-CoA. The observed responses of purified acetyl-CoA carboxylase to changes in pH, and in concentrations of Mg2+, ATP, and ADP, and the reported changes in the chloroplastic concentrations of these effectors during light-dark transitions of chloroplasts are consistent with increased acetyl-CoA carboxylase activity upon illumination of chloroplasts.

The cemetery skeleton. An exercise in the identity of skeletal remains.

In this brief case report, we describe the several means used in 1982 to identify the skeletal remains of a person who disappeared In August 1964. This report exemplifies the multidisciplinary, cooperative approach required for a successful result in such cases.