Precision large field scanning system for high numerical aperture lenses and application to femtosecond micromachining of ophthalmic materials

A precision, large stroke (nearly 1 cm) scanning system was designed, built, and calibrated for micromachining of ophthalmic materials including hydrogels and cornea (excised and in vivo). This system comprises a flexure stage with an attached objective on stacked vertical and horizontal translation stages. This paper outlines the design process leading to our most current version including the specifications that were used in the design and the drawbacks of other methods that were previously used. Initial measurements of the current version are also given. The current flexure was measured to have a 27 Hz natural frequency with no load.

Completion of isoniazid preventive therapy and survival in HIV-infected, TST-positive adults in Tanzania

SETTING

The World Health Organization recommends the use of isoniazid preventive therapy (IPT) for human immunodeficiency virus (HIV) infected patients with a positive tuberculin skin test (TST). However, due to concerns about the effectiveness of IPT in community health care settings and the development of drug resistance, these recommendations have not been widely implemented in countries where tuberculosis (TB) and HIV co-infection is common.

OBJECTIVE

To evaluate the effectiveness of IPT on survival and TB incidence among HIV-infected patients in Tanzania.

DESIGN

A cohort study nested within a randomized trial of HIV-infected adults with baseline CD4 counts of ≥ 200 cells/μ l was conducted to compare survival and incidence of active TB between TST-positive subjects who did or did not complete 6 months of IPT in the period 2001-2008.

RESULTS

Of 558 TST-positive subjects in the analytic cohort, 488 completed 6 months of IPT and 70 did not. Completers had a decrease in mortality compared to non-completers (HR 0.4, 95%CI 0.2-0.8). However, the protective effect of IPT on the incidence of active TB was non-significant (HR 0.6, 95%CI 0.3-1.3).

CONCLUSION

Completion of IPT is associated with increased survival in HIV-infected adults with CD4 counts ≥ 200 cells/μ l and a positive TST.

Temporal trends in non-small cell lung cancer survival in Sweden

We modeled temporal trends in the 1- and 5-year survival of 32 499 patients with adenocarcinoma and squamous cell carcinoma of the lung in the Swedish Cancer Register between 1961 and 2000. The 1-year relative survival for adenocarcinoma improved from 37% for patients diagnosed 1961–1965 to 45% for those diagnosed 1996–2000 and from 39 to 45% for squamous cell carcinoma. The adjusted excess mortality ratios for the period 1996–2000 compared with 1961–1965 were 0.80 for adenocarcinoma and 0.81 for squamous cell carcinoma. Thus, a previous report in a Dutch study of a relatively worsening prognosis for adenocarcinoma over time could not be confirmed.

Effects of genetically modified herbicide-tolerant cropping systems on weed seedbanks in two years of following crops

The Farm Scale Evaluations (FSEs) showed that genetically modified herbicide-tolerant (GMHT) cropping systems could influence farmland biodiversity because of their effects on weed biomass and seed production. Recently published results for winter oilseed rape showed that a switch to GMHT crops significantly affected weed seedbanks for at least 2 years after the crops were sown, potentially causing longer-term effects on other taxa. Here, we seek evidence for similar medium-term effects on weed seedbanks following spring-sown GMHT crops, using newly available data from the FSEs. Weed seedbanks following GMHT maize were significantly higher than following conventional varieties for both the first and second years, while by contrast, seedbanks following GMHT spring oilseed rape were significantly lower over this period. Seedbanks following GMHT beet were smaller than following conventional crops in the first year after the crops had been sown, but this difference was much reduced by the second year for reasons that are not clear. These new data provide important empirical evidence for longer-term effects of GMHT cropping on farmland biodiversity.

Phylogenetic relationships within hump-winged grigs, Cyphoderris (Insecta, Orthoptera, Tettigonioidea, Haglidae)

The genus Cyphoderris, or hump-winged grigs, is represented by three species of cold-adapted, acoustic Ensifera with a geographic distribution that is generally restricted to the high-elevation coniferous forests of western North America. A phylogenetic analysis based on 29 morphological and 3 behavioural characters produced one tree, (C. buckelli (C. strepitans, C. monstrosa)) with a consistency index of 1.0. We discuss possible explanations for the observation that almost all of the autapomorphic change was concentrated in C. monstrosa.

Effect of physician recommendation and patient adherence on rates of colorectal cancer testing

This study explored: (1) patient characteristics associated with physician recommendation for colorectal cancer (CRC) screening and patient adherence to recommendation, and (2) the combined effect of recommendation and adherence on CRC testing, broadly defined. Data were from the 1999 MA BRFSS and a call-back survey of 869 BRFSS participants, age 50 and older. Logistic regression was used to identify correlates of recommendation, adherence, and testing. Patient-physician factors were positively associated with recommendation, adherence and testing. Inadequate health insurance was negatively associated with recommendation (OR = 0.45, 95% CI = 0.27-0.78) and testing (OR = 0.64, 95% CI = 0.38-1.1). Men were not more likely to be recommended (OR = 1.1, 95% CI = 0.78-1.5), but were more likely to adhere (OR = 1.9, 95% CI = 1.2-2.0) and to be tested (OR = 1.4, 95% CI = 1.0-1.9). There were gender differences in recommendation when considering health and risk factor measures. Research is needed to understand differences in recommendation and adherence. Greater encouragement and follow-through may be needed for groups less likely to adhere.

Effect of vagility potential on dispersal and speciation in rainforest insects

Explaining global patterns of species diversity is one of the most challenging objectives in biology. Most agree that complex interactions between historical and current processes are responsible for such patterns, although rigorous testing of possible mechanisms has proved difficult. Here we demonstrate that macropterous and flightless insects in the rainforests of north-eastern Australia have dispersed and speciated in similar manners. These results contradict the traditionally held assumption that differences in vagility potential would lead to significant differences in distributional patterns and speciation modes.

On the rationale and interpretation of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

Farmland biodiversity and food webs were compared in conventional and genetically modified herbicide-tolerant (GMHT) crops of beet (Beta vulgaris L.), maize (Zea mays L.) and both spring and winter oilseed rape (Brassica napus L.). GMHT and conventional varieties were sown in a split-field experimental design, at 60-70 sites for each crop, spread over three starting years beginning in 2000. This paper provides a background to the study and the rationale for its design and interpretation. It shows how data on environment, field management and the biota are used to assess the current state of the ecosystem, to define the typical arable field and to devise criteria for selecting, sampling and auditing experimental sites in the Farm Scale Evaluations. The main functional and taxonomic groups in the habitat are ranked according to their likely sensitivity to GMHT cropping, and the most responsive target organisms are defined. The value of the seedbank as a baseline and as an indicator of historical trends is proposed. Evidence from experiments during the twentieth century is analysed to show that large changes in field management have affected sensitive groups in the biota by ca. 50% during a year or short run of years--a figure against which to assess any positive or negative effects of GMHT cropping. The analysis leads to a summary of factors that were, and were not, examined in the first 3 years of the study and points to where modelling can be used to extrapolate the effects to the landscape and the agricultural region.

Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. II. Within-field epigeal and aerial arthropods

The effects of the management of genetically modified herbicide-tolerant (GMHT) crops on the abundances of aerial and epigeal arthropods were assessed in 66 beet, 68 maize and 67 spring oilseed rape sites as part of the Farm Scale Evaluations of GMHT crops. Most higher taxa were insensitive to differences between GMHT and conventional weed management, but significant effects were found on the abundance of at least one group within each taxon studied. Numbers of butterflies in beet and spring oilseed rape and of Heteroptera and bees in beet were smaller under the relevant GMHT crop management, whereas the abundance of Collembola was consistently greater in all GMHT crops. Generally, these effects were specific to each crop type, reflected the phenology and ecology of the arthropod taxa, were indirect and related to herbicide management. These results apply generally to agriculture across Britain, and could be used in mathematical models to predict the possible long-term effects of the widespread adoption of GMHT technology. The results for bees and butterflies relate to foraging preferences and might or might not translate into effects on population densities, depending on whether adoption leads to forage reductions over large areas. These species, and the detritivore Collembola, may be useful indicator species for future studies of GMHT management.

Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. I. Soil-surface-active invertebrates

The effects of herbicide management of genetically modified herbicide-tolerant (GMHT) beet, maize and spring oilseed rape on the abundance and diversity of soil-surface-active invertebrates were assessed. Most effects did not differ between years, environmental zones or initial seedbanks or between sugar and fodder beet. This suggests that the results may be treated as generally applicable to agricultural situations throughout the UK for these crops. The direction of the effects was evenly balanced between increases and decreases in counts in the GMHT compared with the conventional treatment. Most effects involving a greater capture in the GMHT treatments occurred in maize, whereas most effects involving a smaller capture were in beet and spring oilseed rape. Differences between GMHT and conventional crop herbicide management had a significant effect on the capture of most surface-active invertebrate species and higher taxa tested in at least one crop, and these differences reflected the phenology and ecology of the invertebrates. Counts of carabids that feed on weed seeds were smaller in GMHT beet and spring oilseed rape but larger in GMHT maize. In contrast, collembolan detritivore counts were significantly larger under GMHT crop management.

Invertebrates and vegetation of field margins adjacent to crops subject to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

The effects of management of genetically modified herbicide-tolerant (GMHT) crops on adjacent field margins were assessed for 59 maize, 66 beet and 67 spring oilseed rape sites. Fields were split into halves, one being sown with a GMHT crop and the other with the equivalent conventional non-GMHT crop. Margin vegetation was recorded in three components of the field margins. Most differences were in the tilled area, with fewer smaller effects mirroring them in the verge and boundary. In spring oilseed rape fields, the cover, flowering and seeding of plants were 25%, 44% and 39% lower, respectively, in the GMHT uncropped tilled margins. Similarly, for beet, flowering and seeding were 34% and 39% lower, respectively, in the GMHT margins. For maize, the effect was reversed, with plant cover and flowering 28% and 67% greater, respectively, in the GMHT half. Effects on butterflies mirrored these vegetation effects, with 24% fewer butterflies in margins of GMHT spring oilseed rape. The likely cause is the lower nectar supply in GMHT tilled margins and crop edges. Few large treatment differences were found for bees, gastropods or other invertebrates. Scorching of vegetation by herbicide-spray drift was on average 1.6% on verges beside conventional crops and 3.7% beside GMHT crops, the difference being significant for all three crops.

Crop management and agronomic context of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

The Farm Scale Evaluations of genetically modified herbicide-tolerant crops (GMHT) were conducted in the UK from 2000 to 2002 on beet (sugar and fodder), spring oilseed rape and forage maize. The management of the crops studied is described and compared with current conventional commercial practice. The distribution of field sites adequately represented the areas currently growing these crops, and the sample contained sites operated at a range of management intensities, including low intensity. Herbicide inputs were audited, and the active ingredients used and the rates and the timings of applications compared well with current practice for both GMHT and conventional crops. Inputs on sugar beet were lower than, and inputs on spring oilseed rape and forage maize were consistent with, national averages. Regression analysis of herbicide-application strategies and weed emergence showed that inputs applied by farmers increased with weed densities in beet and forage maize. GMHT crops generally received only one herbicide active ingredient per crop, later and fewer herbicide sprays and less active ingredient (for beet and maize) than the conventional treatments. The audit of inputs found no evidence of bias.

Responses of plants and invertebrate trophic groups to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

Effects of genetically modified herbicide-tolerant (GMHT) and conventional crop management on invertebrate trophic groups (herbivores, detritivores, pollinators, predators and parasitoids) were compared in beet, maize and spring oilseed rape sites throughout the UK. These trophic groups were influenced by season, crop species and GMHT management. Many groups increased twofold to fivefold in abundance between early and late summer, and differed up to 10-fold between crop species. GMHT management superimposed relatively small (less than twofold), but consistent, shifts in plant and insect abundance, the extent and direction of these effects being dependent on the relative efficacies of comparable conventional herbicide regimes. In general, the biomass of weeds was reduced under GMHT management in beet and spring oilseed rape and increased in maize compared with conventional treatments. This change in resource availability had knock-on effects on higher trophic levels except in spring oilseed rape where herbivore resource was greatest. Herbivores, pollinators and natural enemies changed in abundance in the same directions as their resources, and detritivores increased in abundance under GMHT management across all crops. The result of the later herbicide application in GMHT treatments was a shift in resource from the herbivore food web to the detritivore food web. The Farm Scale Evaluations have demonstrated over 3 years and throughout the UK that herbivores, detritivores and many of their predators and parasitoids in arable systems are sensitive to the changes in weed communities that result from the introduction of new herbicide regimes.

Correlates of colorectal cancer testing in Massachusetts men and women

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related death. Although CRC screening can reduce CRC mortality, it is underutilized. We examined the association between personal and health care characteristics and CRC testing, defined as being current on any test that meets CRC screening guidelines.

METHODS

The current investigation relies on questionnaire data from the 1999 Massachusetts Behavioral Risk Factor Surveillance System and a CRC call-back survey of 869 Behavioral Risk Factor Surveillance System participants age 50 and older. Multivariate logistic regression was used to identify predictors of CRC testing. All analyses were stratified by gender.

RESULTS

Men were more likely than women to be currently tested for CRC. Physician recommendation for testing was strongly associated with testing among men and women, but among those with a recommendation, men were more likely to be tested than women. Older age, usually having an annual check-up, and HMO membership were associated with CRC testing among men and women. Perceived high risk of CRC was more strongly associated with testing among men, while other cancer screening was more strongly associated with testing among women.

CONCLUSIONS

There are important gender differences in the prevalence of CRC testing and in factors associated with testing. Research into understanding gender differences related to compliance with physician recommendations is warranted.

Tobacco use among adults with disabilities in Massachusetts

OBJECTIVES

To examine the characteristics of smoking among adults with disabilities in Massachusetts.

DESIGN

Data were obtained from the 1996-1999 Massachusetts Behavioral Risk Factor Surveillance System, a random digit dial telephone survey. Respondents reporting use of special equipment or a limitation caused by impairment or health problem were classified as having a disability. Adults with disabilities were further classified by level, based on need for assistance, and type of disability. Logistic regression models were used to assess the association between disability status and smoking.

SETTING AND PARTICIPANTS

Random sample of non-institutionalised Massachusetts adults, 18 and older, with disabilities (n = 2985) and without disabilities (n = 14 395).

MAIN OUTCOME MEASURES

Smoking status, intensity, and factors related to quitting.

RESULTS

Compared to those without disabilities, adults with disabilities were more likely to have ever smoked (odds ratio (OR) 1.42, 95% confidence interval (CI) 1.25 to 1.61) and to be current smokers (OR 1.52, 95% CI 1.32 to 1.76). Smoking rates varied by type of disability. Among current smokers, adults with disabilities smoked more cigarettes per day (OR 1.65, 95% CI 1.31 to 2.16), sooner after waking (OR 1.50, 95% CI 1.13 to 1.99), and were more likely to be advised by a doctor to quit (OR 2.07, 95% CI 1.60 to 2.69). Adults with disabilities who needed assistance were more likely to be planning to quit (OR 1.50, 95% CI 0.99 to 2.26).

CONCLUSIONS

There are disparities in smoking rates between adults with and without disabilities. Smoking cessation programmes targeted to the disabled community are needed.

The stage-regulated expression of Leishmania mexicana CPB cysteine proteases is mediated by an intercistronic sequence element

The tandemly arranged CPB genes of Leishmania mexicana are polycistronically transcribed and encode cysteine proteases that are differentially stage-specific; CPB1 and CPB2 are expressed predominantly in metacyclics, whereas CPB3-CPB18 are expressed mainly in amastigotes. The mechanisms responsible for this differential expression have been studied via gene analysis and re-integration of individual CPB genes, and variants thereof, into a CPB-deficient parasite mutant. Comparison of the nucleotide sequences of the repeat units of CPB1 and CPB2 with CPB2.8 (typical of CPB3-CPB18) revealed two major regions of divergence as follows: one of 258 base pairs (bp) corresponding to the C-terminal extension of CPB2.8; another, designated InS, of 120 bp, with insertions totaling 57 bp, localized to the intercistronic region downstream of CPB1 and CPB2. Cell lines expressing CPB2.8 or CPB2 with the 3'-untranslated region and intercistronic sequence of CPB2.8 showed up-regulation in amastigotes. Conversely, metacyclic-specific expression occurred with CPB2 or CPB2.8 with the 3'-untranslated region and intercistronic sequence of CPB2. Moreover, the InS down-regulated expression in amastigotes of a reporter gene integrated into the CPB locus. It is proposed that the InS mediates metacyclic-specific stage-regulated expression of CPB by affecting the maturation of polycistronic pre-mRNA. This is the first well defined cis-regulatory element implicated in post-transcriptional stage-specific gene expression in Leishmania.

Morphological and molecular description of Haematoloechus meridionalis n. sp. (Digenea: Plagiorchioidea: Haematoloechidae) from Rana vaillanti brocchi of Guanacaste, Costa Rica

An undescribed species of Haematoloechus inhabits the lungs of Rana vaillanti in northwestern Costa Rica. The new species is most similar morphologically to H. medioplexus, having a very small, but well-developed, ventral sucker and lacking extracecal uterine loops, and apparently was mis-identified previously as H. medioplexus in Rana palmipes from Colombia. It differs from H. medioplexus, notably by (1) the shape of the oral sucker, which is elliptical in H. meridionalis and spherical in H. medioplexus; (2) the posterior extent of the vitelline fields, which terminate at the same level in H. medioplexus, but always at different levels in H. meridionalis; (3) the position of the testes, which are immediately posterior to the seminal receptacle and are close together in the new species and far from the seminal receptacle and separated from each other in H. medioplexus; and (4) the location of the genital pore, which is ventral to the cecal bifurcation in the new species and ventral to the pharynx in H. medioplexus. In addition, the new species is unique among members of Haematoloechus by having flaps of tissue on the interior margins of the ventral sucker. The new species shows almost 5% sequence divergence from H. medioplexus in the variable D1 region of the 28s rDNA, complementing the morphological differences.

Description of Buckarootrema goodmani n. g., n. sp. (Digenea: Pronocephalidae), a parasite of the freshwater turtle Emydura macquarii (Gray, 1830) (Pleurodira: Chelidae) from Queensland, Australia, and a phylogenetic analysis of the genera of the Pronocephalidae Looss, 1902

Buckarootrema goodmani n. g., n. sp. is described from the small intestine of the Murray turtle, Emydura macquarii (Gray, 1830), from the vicinity of Warwick, Queensland, Australia. The distinctive taxonomic features include the vitellarium, which consists of 2 compact masses directly anterior to and occasionally overlapping the testes; the uterus with extensive pre- and postovarian coils; intestinal ceca with small, medial diverticula that terminate anterior to or at the anterior margin of the testes; a comma-shaped cirrus sac with both internal and external seminal vesicles. Phylogenetic systematic analysis of the genera of the Pronocephalidae including Buckarootrema and Notopronocephalus, the only other genus of pronocephalids reported from Australian freshwater turtles, indicates that Buckarootrema is the sister taxon of Neopronocephalus and Notopronocephalus is the sister group of the rest of the Pronocephalinae.

Functional expression and characterization of the cytoplasmic aminopeptidase P of Caenorhabditis elegans

Aminopeptidase P (AP-P; X-Pro aminopeptidase; EC 3.4.11.9) cleaves the N-terminal X-Pro bond of peptides and occurs in mammals as both cytosolic and plasma membrane forms, encoded by separate genes. In mammals, the plasma membrane AP-P can function as a kininase, but little is known about the physiological role of the cytosolic enzyme. The C. elegans genome contains a single gene encoding AP-P (W03G9.4), analysis of which predicts regions displaying high levels of amino-acid sequence homology between the predicted gene product and mammalian cytoplasmic AP-P, with the absolute conservation of key catalytic residues. The sequence of an EST (yk91g4), comprising the open reading frame of W03G9.4, confirmed the predicted genomic structure of the gene and the prediction that W03G9.4 codes for a nonsecreted protein with a molecular mass of 68 kDa. Nematodes transformed with a promoter reporter construct, W03G9.4:GFP, showed high levels of fluorescence in the intestine of larvae and adult hermaphrodites, indicating that the intestine is a major site of W03G9.4 expression. yk91g4 tagged with a hexahistidine and DLYDDDDK peptide epitope was expressed in Escherichia coli to yield, after affinity purification, a recombinant protein with a molecular mass of 71 kDa. The recombinant W03G9.4 removed the N-terminal amino acid from bradykinin (RPPGFSPFR), a Caenorhabditis elegans neuropeptide (KPSFVRFamide) and Lem Trp 1 (APSGFLGVRamide), but did not display activity towards angiotensin I (NRVYIHPFHL), des-Arg bradykinin and AF1 (KNEFIRFamide). The activity towards bradykinin was inhibited by EDTA and 1, 10 phenanthroline, as expected for a metalloenzyme, and also by apstatin (IC50, 1 microM), a selective inhibitor of mammalian AP-P. A Km of 45 microM and an optimum pH of 7-8 was observed with bradykinin as the substrate. The activity of the nematode AP-P, like its mammalian counterparts, was strongly influenced by metal ions, with Co2+, Mn2+ and Zn2+ all inhibiting the hydrolysis of bradykinin. We conclude that W03G9.4 codes for a cytoplasmic AP-P with very similar enzymatic properties to those of mammalian AP-P, and we suggest that the enzyme has a physiological role in the intracellular hydrolysis of proline-containing peptides absorbed from the lumen of the intestine.

Support for condom availability and needle exchange programs among Massachusetts adults, 1997

This study was conducted to determine whether demographic factors, variables related to HIV risk status, or personal attitudes predicted public support for condom availability programs in high schools and needle exchange programs. Data for these analyses were collected from the 1997 Massachusetts Behavioral Risk Factor Surveillance System (BRFSS) among adults aged 18-64. Overall, 79% of Massachusetts adults aged 18-64 supported condom availability programs, and 60% supported needle exchange programs. Younger age was the strongest demographic predictor of support for condom availability, and higher socioeconomic status was the strongest predictor of support for needle exchange programs. Support for both programs was weakly associated with personal HIV risk status but strongly associated with positive attitudes toward teaching about HIV in schools and advising sexually active teens to use condoms. Our data suggest that there is broad-based public support for implementation of condom availability and needle exchange programs as tools for HIV prevention.

Lower use of dental services among long term cigarette smokers

STUDY OBJECTIVE

Given the advanced stage of most oral cancer cases at diagnosis, it is hypothesised that a significant proportion of higher risk adults do not visit a dentist annually. The study objectives were to assess whether long term smokers were less likely to visit the dentist.

DESIGN

Data from the 1998 Massachusetts Behavioral Risk Factor Surveillance System, a population-based, random digit dial telephone health survey, were used to evaluate whether adults at higher risk of oral cancer attributable to long term cigarette smoking were less likely to go to the dentist, controlling for socioeconomic, demographic, and health related characteristics.

PATIENTS

A representative sample of 2119 Massachusetts adults aged 35 and older.

MAIN RESULTS

Adults who were long term smokers were less likely than never smokers to have visited the dentist in the previous year (adjusted OR = 0.69, 95% confidence intervals (CI) = 0.48, 0.99). Moreover, adults who were at higher risk from both long term smoking and low fruit and vegetable consumption were even less likely to visit the dentist than adults with neither risk factor (adjusted OR = 0.39, 95% CI = 0.22, 0.68). Among long term smokers, the likelihood of a yearly examination decreased with increasing smoking duration and amount smoked per day.

CONCLUSIONS

These findings support the hypothesis that adults at higher risk of oral cancer attributable to long term cigarette smoking are less likely to have routine dental examinations, even controlling for socioeconomic and health related differences.

Parasite systematics in the 21st century: opportunities and obstacles

Taxonomic names and phylogenetic hypotheses are indispensable tools for modern biological research, both basic and applied. Like all disciplines, parasitology suffers from the 'taxonomic impediment' - a global shortage of professional taxonomists and systematists. Only a fraction of the species of parasites on this planet have been identified, and the evolutionary relationships of only a minority of those are understood; thus, information on how to manage parasite biodiversity, including known and potential disease agents, is incomplete. A renewal of systematic parasitology has a key role in redefining the relationship between mankind and the organisms whose biology fascinates us so much.

Anindobothrium n. gen. (Eucestoda: Tetraphyllidea) inhabiting marine and freshwater potamotrygonid stingrays

Anindobothrium n. gen. is proposed to accommodate Caulobothrium anacolum inhabiting Himantura schmardae from Colombia, and 2 new species, one inhabiting Potamotrygon orbigny in Brazil and the other inhabiting Paratrygon aereiba in Venezuela. Members of the new genus resemble members of Pararhinebothroides, Rhinebothroides, and Anthocephalum by having bothridia with poorly differentiated apical suckers and vasa deferentia expanded into external seminal vesicles. It further resembles Pararhinebothroides, Rhinebothroides, and Anthocephalum cairae by having vas deferens inserted near the poral rather than aporal end of the cirrus sac. The 3 species assigned to the new genus form an apparent monophyletic group, based on the possession of 3 putative synapomorphies: (1) genital pores in the anterior 1/4 of the proglottid, a trait that is unusual, but not unique, among phyllobothriids; (2) anteroventral ovarian lobes converging to the center of the proglottid, a character not previously reported for phyllobothriids; and (3) ovarian lobes comprising a loose network of digitiform processes.

Asbestos content of omentum and mesentery in nonoccupationally exposed individuals

Asbestos fibers in occupationally exposed individuals relocate from the lung to extrapulmonary sites. A mechanism for relocation is via the lymphatic circulation. Indeed, asbestos fibers have been found in lymph nodes as well as pleural plaques. Our laboratory has recently shown that asbestos fibers also reach the mesentery and omentum in the peritoneal area where a small percentage of mesotheliomas occurs in exposed individuals. The present study uses light and analytical transmission electron microscopy for defining the asbestos burden in digested lung, omentum, and mesentery tissues from individuals considered as representing the general population in East Texas. The findings, when compared with previous data from occupationally exposed individuals, indicate extreme contrasts as to the level and types of fiber burden between individuals representing the groups.

Parasite systematics in the 21st century: opportunities and obstacles

Thanks to the phylogenetic systematics revolution, systematic parasitology is poised to make significant contributions in tropical medicine and public health, biodiversity science, and evolutionary biology. At the same time, the taxonomic impediment is acute within parasitology. Both systematists and non-systematists must be interested in working towards common goals and establishing collaborative efforts in order to re-vitalize and re-populate systematic parasitology.

Support for smoke-free restaurants among Massachusetts adults, 1992-1999

OBJECTIVES

The authors examined trends and predictors of public support for smoke-free restaurants in Massachusetts.

METHODS

Since 1992, the Massachusetts Behavioral Risk Factor Surveillance System has asked survey respondents about their attitudes toward smoking in restaurants. Analyses using data from 1992 to 1999 characterized changes over time in support for smoke-free restaurants and the role of demographic and smoking-related factors in predicting support.

RESULTS

During 1992 to 1999, the rate of support for smoke-free restaurants increased from 37.5% to 59.8%, with similar increases among current, former, and never smokers. After adjustment for smoking status, support was associated with socioeconomic characteristics, race/ethnicity, and household smoking rules. Among current smokers, lighter smokers and those who were trying to quit were more likely to endorse smoke-free restaurants.

CONCLUSIONS

There has been a substantial increase in support for smoke-free restaurants among both smokers and nonsmokers in Massachusetts.

Processing and trafficking of cysteine proteases in Leishmania mexicana

Removal of the pro-domain of a cysteine protease is essential for activation of the enzyme. We have engineered a cysteine protease (CPB2.8) of the protozoan parasite Leishmania mexicana by site-directed mutagenesis to remove the active site cysteine (to produce CPB(C25G)). When CPB(C25G) was expressed in a L. mexicana mutant lacking all CPB genes, the inactive pro-enzyme was processed to the mature protein and trafficked to the lysosome. These results show that auto-activation is not required for correct processing of CPB in vivo. When CPB(C25G) was expressed in a L. mexicana mutant lacking both CPA and CPB genes, the majority of the pro-enzyme remained unprocessed and accumulated in the flagellar pocket. These data reveal that CPA can directly or indirectly process CPB(C25G) and suggest that cysteine proteases are targeted to lysosomes via the flagellar pocket. Moreover, they show that another protease can process CPB in the absence of either CPA or CPB, albeit less efficiently. Abolition of the glycosylation site in the mature domain of CPB did not affect enzyme processing, targeting or in vitro activity towards gelatin. This indicates that glycosylation is not required for trafficking. Together these findings provide evidence that the major route of trafficking of Leishmania cysteine proteases to lysosomes is via the flagellar pocket and therefore differs significantly from cysteine protease trafficking in mammalian cells.

Health status and health care use of Massachusetts women reporting partner abuse

BACKGROUND

Studies indicate that women abused by their intimate partners are at increased risk for a number of health problems and have increased rates of health care utilization. However, these findings are based mainly on studies using clinic or health plan populations. In this study, we examined the association between intimate partner abuse (IPA) and health concerns and health care utilization in a population-based sample of adult women.

METHODS

We analyzed data on 2043 women aged 18 to 59 who participated in the 1998 Massachusetts Behavioral Risk Factor Surveillance System (BRFSS), a population-based health survey that included questions on IPA. IPA was defined as experiencing physical violence by, fear of, or control by an intimate partner. Consequences of IPA and self-rated health status and health care utilization of women experiencing IPA were examined.

RESULTS

A total of 6.3% of Massachusetts women aged 18 to 59 reported IPA during the past year. Women experiencing IPA were more likely than other women to report depression, anxiety, sleep problems, suicidal ideation, disabilities, smoking, unwanted pregnancy, HIV testing, and condom use. Women experiencing IPA were less likely to have health insurance, but received routine health care at similar rates as other women.

CONCLUSIONS

These results indicate that women in the general population experiencing IPA are at increased risk for several serious emotional and physical health concerns. Most of these women are in routine contact with health care providers. These findings also suggest that the BRFSS may provide a valuable mechanism for tracking state-based IPA prevalence rates over time.

Halipegus eschi n. sp. (Digenea: Hemiuridae) in Rana vaillanti from Guanacaste Province, Costa Rica

Halipegus eschi n. sp. is described from the esophagus of Rana vaillanti from Guanacaste Province, Costa Rica. The new species differs from other known species of Halipegus on the basis of relative testis size, lateral extent of the uterus, vitelline follicle arrangement, egg size, and polar filament length.

The nature of the organism. Life has a life of its own

The question of closure in biological systems is central to understanding the origins of the biological variation and complexity upon which various forms of selection act. Much of evolutionary theory, especially in the second half of the twentieth century, is concerned with the consequences of environmental selection acting on bio-diversity, but neglects questions of the origin of that diversity. This has permitted us to act as if an explanation of consequences was the ultimate explanation in biology. However, Darwin understood that evolution was both information driven and information constrained. The link between evolutionary constraints and closure can be profitably explored by starting with Darwin's notion of the primary of "the nature of the organism" over "the nature of the conditions" articulated in the sixth edition of Origin of Species. Contemporary ideas of self-organization, emergence, complexity, and inherent (developmental and phylogenetic) constraints can be seen as an elaboration and refinement of Darwin's views if we adopt the following perspective: (1) information is cheap, not costly, to produce, but may have costly consequences; and (2) information is produced by systems that are informationally closed but remain thermodynamically open.

Stable transformation of trypanosomatids through targeted chromosomal integration of the selectable marker gene encoding blasticidin S deaminase

The susceptibilities of the protozoan parasites Leishmania mexicana and Trypanosoma brucei to the nucleoside antibiotic blasticidin S were assessed. A concentration of 10 microg ml(-1) was sufficient to cause cell death within 72 h of L. mexicana promastigotes and bloodstream forms of T. brucei in vitro. The gene encoding blasticidin S deaminase (BSD) was therefore incorporated into cassettes for targeting to the cysteine proteinase C locus of L. mexicana (CPC::BSD) and the tubulin locus of T. brucei (tub::RAD51-BSR). Following transfection of mutant parasites that contained other well-established selectable marker genes (HYG, NEO, BLE, PAC and SAT), clones resistant to 10 microg ml(-1) blasticidin S were shown by PCR and Southern blotting to have integrated the cassettes by homologous recombination. The results confirm that BSD can be used as a selectable marker gene for targeted chromosomal integration during genetic manipulations of trypanosomatids.

Two new species of Oochoristica Lühe, 1898 (Eucestoda: Cyclophyllidea: Anoplocephalidae: Linstowiinae) parasitic in Ctenosaura spp. (Iguanidae) from Costa Rica and México

Five species of Oochoristica, Oochoristica osheroffi, Oochoristica gracewileyae, Oochoristica whitentoni, and 2 new species described herein have strobilae longer than 200 mm, many secondary ovarian lobes, and testes extending anteriorly to midovarian level. A combination of 3 characters distinguishes the 5 species from each other. Oochoristica osheroffi has an average of 68 testes per proglottid, ovarian lobes wider than long, and osmoregulatory canals not forming an anastomosing plexus; O. gracewileyae has an average of 113 testes per proglottid, ovarian lobes longer than wide, and osmoregulatory canals not forming an anastomosing plexus; O. whitentoni has an average of 125 testes per proglottid, ovarian lobes wider than long, and osmoregulatory canals forming an anastomosing plexus; a new species in Ctenosaura similis from Costa Rica has an average of 62 testes per proglottid, ovarian lobes longer than wide, and osmoregulatory canals forming an anastomosing plexus; and a new species in Ctenosaura pectinata from Mexico has an average of 122 testes per progottid, ovarian lobes longer than wide, and osmoregulatory canals forming an anastomosing plexus. Oochoristica gracewileyae differs from the other 4 species by having genital pores 10-15% rather than 25-35% of proglottid length from the anterior end and by having convoluted rather than straight or sinuous transverse osmoregulatory canals. The new species from Mexico differs from the other 4 species and apparently from all described species of Oochoristica thus far by possessing darkly staining granules throughout the parenchyma of the scolex.

Differentiation of Mexican species of Haematoloechus looss, 1899 (Digenea: Plagiorchiformes): molecular and morphological evidence

Molecular evidence is interpreted in the light of morphology to examine the validity of several species of Haematoloechus described as Mexican endemics. Internal transcribed spacers 1 and 2 and 28S ribosomal genes were sequenced for 11 isolates. Phylogenetic analysis of separate partitions and combined databases was conducted. Results were analyzed, in the light of morphological evidence. Haematoloechus macrorchis is proposed as a junior synonym of Haematoloechus longiplexus. Haematoloechus pulcher is a sibling species with Haematoloechus complexus in Lerma wetlands. In Mexico, Haematoloechus medioplexus is distributed along the east coast coinciding with the distribution of Rana berlandieri. The sister species of H. medioplexus is Haematoloechus coloradensis, sharing the distribution of the uterus as a synapomorphic character. Haematoloechus illimis is more closely related to H. medioplexus and H. coloradensis than to H. complexus. It can be distinguished by the distribution of the uterus, lobed ovary, and testes.

Macroevolutionary patterns of male reproductive investment in a clade of parasitic hermaphrodites

The Eucestoda is particularly relevant for questions concerning reproductive investment in male gametes because no other parasitic group displays such diversity in testis size and number within and among species. This diversity has long been used as a valuable taxonomic character, but few researchers have ever investigated its evolutionary significance. In this paper we investigate the evolution of testis number and size within Rhinebothroides (Platyhelminthes: Eucestoda). Our comparative, phylogenetic analysis revealed that overall allocation to male functions, as measured by relative testicular area, does not change within the clade, even though the packaging of that investment in numerous testes is highly variable within, and diverse among, members of the group.

Species: turning a conundrum into a research program

The most appropriate ontological basis for understanding the role of species in evolutionary biology is the Evolutionary Species Concept. The ESC is not an operational concept, but one version of the Phylogenetic Species Concept is. Linking the ontology of species with the epistemological basis of actual biological studies requires that we specify both a discovery mode for identifying collections of organisms that we believe are evolutionary species, and a series of evaluation criteria for assessing those entities we have discovered. Simply naming a collection of specimens, no matter how strong one's evolutionary beliefs, is not sufficient for declaring that evolutionary species have been discovered. All operational historical species concepts represent discovery modes with minimal evaluation criteria; all operational non-dimensional species concepts represent evaluation criteria that do not specify discovery modes. Thus, both categories of knowledge are necessary and neither is sufficient for assigning species status. This leads naturally to a hierarchical research program in historical ecology, beginning with phylogenetic analysis of a group of entities postulated to be evolutionary species, which provides a productive arena for our arguments about species concepts.

Pararhinebothroides hobergi n. gen. n. sp. (Eucestoda: Tetraphyllidea) in Urobatis tumbesensis (Chondrichthyes: Myliobatiformes) from coastal Ecuador

A new species of tetraphyllidean eucestode inhabiting Urobatis tumbesensis from inshore waters of southeastern Ecuador shares 3 synapomorphies with Rhinebothroides spp.: apical bothridial suckers poorly differentiated from the marginal loculi, internal seminal vesicles, and insertion of the vas deferens dorsally closer to the poral than the aporal end of the cirrus sac. The new species differs from Rhinebothroides spp. by lacking medial bothridial septa and loculi and having symmetrical ovarian arms, and possesses an apparent autapomorphic trait by having the vas deferens tapering to a narrow tube before entering the cirrus sac, extending posteriorly to the posterior end of the cirrus sac where it expands into an external seminal vesicle running ventral to the cirrus sac anteriorly to anterior to the vagina. In Rhinebothroides spp., the vas deferens is expanded into an external seminal vesicle near the insertion into the cirrus sac As the sister group of Rhinebothroides, we propose a new genus to accommodate the new species. Phylogenetic evaluation of phyllobothriids recently assigned to Anthocephalum shows that they represent a paraphyletic assemblage of species of varying degrees of relatedness to Rhinebothroides spp. and the new species. Uncovering the relationships of the new species and the various species assigned to Anthocephalum permitted reevaluation of character transformations used in previous phylogenetic analysis of Rhinebothroides. Transformation series for 3 characters, previously based on functional outgroup comparisons, changed and a new character, length of cirrus sac, was added. The new phylogenetic analysis differs from the previous hypothesis only in placing R. scorzai as the sister species of R. circularisi + R. venezuelae + R. moralarai rather than of R. freitasi + R. glandularis + R. mclennanae. The occurrence of the sister species of Rhinebothroides in a Pacific Ocean stingray adds additional support to the hypothesis of Pacific origins of South American freshwater stingrays.

Scyphophyllidium uruguayense n. sp. (Eucestoda: Tetraphyllidea) in Mustelus mento (Cope, 1877) (Chondrichthyes: Carcharhiniformes: Triakidae) from La Paloma, Uruguay

A new species of Scyphophyllidium inhabits Mustelus mento near La Paloma, Uruguay. It resembles Scyphophyllidium giganteum from the Atlantic Ocean and specimens identified as S. giganteum from California by having anapolytic strobilae 155-258 mm long, 250-300 craspedote proglottids, scoleces 1.2-1.4 mm wide, necks 34-41 mm long, immature and mature proglottids wider than long, gravid proglottids wider than long to longer than wide, genital pores averaging 28% of proglottid length from the anterior end, relatively flat ovaries with digitiform lobes reaching the lateralmost extent of the testicular field, vitellaria in 2 fields converging toward the proglottid midline, straight and short cirrus sacs, and postvaginal vas deferens. The bothridia of the new species have accessory bothridial suckers that are smaller than those of California specimens; European specimens reportedly lack accessory bothridial suckers. The new species possesses a uterine duct that joins the uterus at the level of the genital atrium and ventral osmoregulatory ducts medial rather than lateral to the dorsal ducts, an arrangement described for Californian but not European specimens. It differs from both European and Californian specimens by having longer cirri, more testes per proglottid, prominent scales covering the neck, and vaginae and uterine ducts coiled immediately preovarially. Pithophorus, Marsupiobothrium, and Scyphophyllidium may form a clade.

Roles of cysteine proteinases of trypanosomes and Leishmania in host-parasite interactions

Trypanosomes and Leishmania contain an abundance of stage-regulated cysteine proteinases encoded by several gene families. Analysis of parasites rendered defective in cysteine proteinase function, either through genetic manipulation or through the use of specific inhibitors, has revealed roles for the enzymes in parasite virulence, in modulation of the host's immune response and in parasite differentiation.

Echinocephalus janzeni n. sp. (Nematoda: Gnathostomatidae) in Himantura pacifica (Chondrichthyes: Myliobatiformes) from the Pacific coast of Costa Rica and Mexico, with historical biogeographic analysis of the genus

Echinocephalus janzeni n. sp. in the stingray, Himantura pacifica, is described from the eastern Pacific Ocean off the coasts of Costa Rica and southern Mexico. On the basis of the presence of 6 postanal caudal papillae, and modified annules anterior to the caudal alae in males, E. janzeni is most similar to Echinocephalus daileyi and Echinocephalus diazi. Specimens of E. janzeni are distinguished from those of E. daileyi by bilobed caudal alae and long cervical sacs that extend up to 65% of the length of the esophagus; E. janzeni is differentiated from E. diazi by the number of rows of cephalic spines (30-38 vs. 26-27), arrangement of the postanal caudal papillae, 3 rather than 2 preanal papillae, relative position and distance between the anus and vulva (395-460 microm vs. 70 microm), the digitiform female tail with a terminal cuticular fold, and the length of the female tail (450-480 microm vs. 270 microm). Cladistic analysis of the 10 Echinocephalus spp. resulted in a single most parsimonious tree (consistency index=0.893) and placed E. janzeni in a highly derived subclade where E. daileyi is the sister species of E. diazi + E. janzeni. Historical biogeographic analysis of hosts and parasites provides support for origins in the Pacific rather than the Atlantic for the potamotrygonid stingrays.

Phylogenetic analysis of the Bunocotylinae dollfus, 1950 (Digenea: Hemiuridae)

The phylogenetic analysis of the 16 recognized genera in the Bunocotylinae, based upon 30 morphological transformation series, produced 2 most parsimonious trees, each with a consistency index of 0.62. The monophyly of the group is supported by 6 synapomorphies. Ahemiurus, Aphanuroides, Aphanurus, Myosaccium, and Indoderogenes separate independently in the basal part of the tree. Saturnius and Bunocotyle separate next, forming a clade. Machidatrema, Duosphincter, Theletrum, and Monolecithotrema separate independently; and in the most derived part of the tree Opisthadena + Neopisthadena + Mitrostoma, Genolinea, and Neotheletrum grouped together form a clade. Optimization of hosts and geographic distribution onto the 2 most parsimonious trees suggests that the bunocotylines originated from an ancestor that was host specific to fishes of the Clupeidae and was distributed in the Tethys Sea.

Phylogeny of the orders of the Eucestoda (Cercomeromorphae) based on comparative morphology: historical perspectives and a new working hypothesis

The phylogeny of the Eucestoda was evaluated based on a suite of 49 binary and multistate characters derived from comparative morphological and ontogenetic studies; attributes of adult and larval tapeworms were considered. A single most parsimonious tree (MPT) (consistency index = 0.872; retention index = 0.838; and homoplasy index = 0.527) was fully resolved and is specified by the following: (Gyrocotylidea, (Amphilinidea, ((Spathebothriidea, (Pseudophyllidea, ((Diphyllidea, (Trypanorhyncha, (Tetraphyllidea, (Lecanicephalidea, ((Nippotaeniidea, (Tetrabothriidea, Cyclophyllidea)), Proteocephalidea))))), Haplobothriidea))), Caryophyllidea))). Monophyly for the Eucestoda was firmly corroborated. Trees derived from the primary and bootstrap analyses were congruent, but low values, particularly for relationships among the tetrafossate tapeworms, indicated additional examination is warranted. The MPT was found to be the most efficient hypothesis for describing character evolution and in specifying relationships among the orders when compared to those concepts that had been developed for the tapeworms over the past century. Areas of congruence were shared among the current hypothesis and one or more of the prior hypotheses. Major conclusions include: (1) Caryophyllidea are basal and monozooy is ancestral; (2) difossate forms are primitive, and the Pseudophyllidea are the sister group of the strongly polyzoic tapeworms; (3) Nippotaeniidea are highly derived; (4) the higher tapeworms (Tetraphyllidea, Lecanicephalidea, Proteocephalidea, Nippotaeniidea, Tetrabothriidea, and Cyclophyllidea) are closely related or potentially coordinate groups: (5) Tetrabothriidea and the Cyclophyllidea are sister groups; and (6) Tetraphyllidea is paraphyletic, with the Onchobothriidae basal to the Phyllobothriidae. Character support for placement of the Tetrabothriidea continues to be contradictory, and this order may represent a key to understanding the phylogeny of the higher cestodes. The current study constitutes a complete historical review and poses a new and robust hypothesis for the phylogeny of the Eucestoda.

Evolution of the schistosomes (Digenea: Schistosomatoidea): the origin of dioecy and colonization of the venous system

Trematodes of the family Schistosomatidae are considered venous system specialists whose sister group is the vascular system generalists (Spirorchidae) of turtles. Colonization of homeotherms by vascular trematodes required precision egg laying near the conduit for egg passage to the external environment and avoidance of pathogenesis that might result in the premature death of the host. Evolution of dioecy from the hermaphroditic condition may have proceeded through androdioecy in which hermaphrodites were specialized for precision egg placement in the vascular system and larger adults became functional males. The evolution of nuclear genes suppressing female function along with cytoplasmic genes suppressing male function could then have resulted in the origin of dioecious, dimorphic populations. Schistosomes compensated for the reduction in potential reproductive partners by (1) increased overdispersion in the vertebrate host, (2) reduced egg hatching time in the external environment, (3) formation of permanent pairs mimicking the hermaphroditic condition, (4) increased longevity in the definitive host, and (5) increased fecundity. Colonization of the venous system was necessitated by (1) evolutionary radiation into terrestrial vertebrates and (2) the increased immunopathology associated with the high, constant body temperature of homeothermic vertebrates. The immune response to spirorchid and schistosome eggs appears to be qualitatively similar in their respective hosts. The arterial dwelling spirorchids release eggs in the direction of blood flow, resulting in a wide dissemination of eggs within the host. The lower body temperature of poikilotherms accompanied by the seasonal nature of the immune response in these hosts would result in a quantitatively reduced pathogenesis. Hosts that did succumb to the infection would most likely die in water, where eggs could be released by predation, scavengers, or decomposition and develop successfully. Colonization of the venous system by schistosomes would require precision egg placement because eggs are released against blood flow. Eggs are sequestered within the portal system of homeotherms, thus restricting egg dispersal and resulting pathogenesis to less sensitive organs. A significant number of eggs may escape into the external environment before a heavily infected host is incapacitated by, or dies from, the infection.

Six species of Acanthobothrium (Eucestoda: Tetraphyllidea) in stingrays (Chondrichthyes: Rajiformes: Myliobatoidei) from Ecuador

Six species of Acanthobothrium, 4 described as new, are reported in stingrays from southern Ecuador. Acanthobothrium atahualpai n. sp. in Gymnura afuerae most closely resembles Acanthobothrium fogeli and Acanthobothrium parviuncinatum by having bothridial hooks with recurved prongs and short handles. It differs from A. fogeli by having bothridial hooks 163-195 microns vs. 78-114 microns long and averaging 25 vs. 32 testes per pruglottis: it differs from A. parviuncinatum by having bothridial hooks 163-195 microns vs. 87 microns long and averaging 25 vs. 13 testes per proglottis. Acanthobothrium minusculus n. sp. in Urolophus tumbesensis most resembles Acanthobothrium campbelli and Acanthobothrium vargasi by being no more than 3 mm long and having 6-30 testes per proglottis. It can be distinguished from them by having bothridial hooks averaging 86 microns vs. 108-111 microns and 130-133 microns long, and 6-10 vs. 15-23 and 22-29 testes per proglottis, respectively. Acanthobothrium monksi n. sp. in Aetobatus narinari resembles Acanthobothrium tasajerasi from Himantura schmardae by having a prominent genital atrium and a large globose cirrus sac; it differs by averaging 21 vs. 35 testes per proglottis and having bothridial hooks averaging 150 microns vs. 165 microns long. Acanthobothrium obuncus n. sp. in Dasyatis longus resembles a group of species characterized by wider than long to square immature and mature proglottides, bothridia at least partially fused to the scolex at their posterior ends, and asymmetrical ovarian arms with aporal arms extending anteriorly to the vaginal level. It resembles Acanthobothrium americanum by averaging 73 vs. 72 testes per proglottis, but differs by having bothridial hooks averaging 120-131 microns vs. 151 microns long; it resembles Acanthobothrium chilensis by having bothridial hooks averaging 120-131 microns vs. 130 microns long, but differs by averaging 73 vs. 90 testes per proglottis. Acanthobothrium campbelli in Urotrygon chilensis and Acanthobothrium costarricense in Dasyatis longus, previously known in those hosts from the Pacific coast of Costa Rica, are reported from Ecuador for the first time.

The multiple cpb cysteine proteinase genes of Leishmania mexicana encode isoenzymes that differ in their stage regulation and substrate preferences

The cpb genes of Leishmania mexicana encode stage-regulated, cathepsin L-like cysteine proteinases that are leishmanial virulence factors. Field inversion gel electrophoresis and genomic mapping indicate that there are 19 cpb genes arranged in a tandem array. Five genes from the array have been sequenced and their expression analyzed. The first two genes, cpb1 and cpb2, differ significantly from the remaining 17 copies (cpb3-cpb19) in that: 1) they are expressed predominantly in metacyclic promastigotes (the form in the insect vector which is infective to mammalian macrophages) rather than amastigotes (the form that parasitizes mammals); 2) they encode enzymes with a truncation in the COOH-terminal extension, an unusual feature of these cysteine proteinases of trypanosomatids. Transfection of cpb1 into a cpb null mutant resulted in expression of an active enzyme that was shown by immunogold labeling with anti-CPB antibodies to be targeted to large lysosomes. This demonstrates that the 100-amino acid COOH-terminal extension is not essential for the activation or activity of the enzyme or for its correct intracellular trafficking. Transfection into the cpb null mutant of different copies of cpb and analysis of the phenotype of the lines showed that individual isoenzymes differ in their substrate preferences and ability to restore the loss of virulence associated with the null mutant. Comparison of the predicted amino acid sequences of the isoenzymes implicates five residues located in the mature domain (Asn18, Asp60, Asn61, Ser64, and Tyr84) with differences in the activities of the encoded isoenzymes. The results suggest that the individual isoenzymes have distinct roles in the parasite's interaction with its host. This complexity reflects the adaptation of cathepsin L-like cysteine proteinases to diverse functions in parasitic protozoa.