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D R Brooks

Publications and source records attributed to D R Brooks.

At least 37 records · Page 2Linked to original sources
PubMed2001

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.

Animals↗
PubMed2001

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.

Animals↗
PubMed2001

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.

Adolescent↗
PubMed2000

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.

Aminohydrolases↗
PubMed2000

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.

Adolescent↗
PubMed2000

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.

Biological Evolution↗
PubMed2000

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.

Animals↗
PubMed2000

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.

Animals↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Analysis of Variance↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Ambystoma↗
PubMed1998

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.

Animals↗
PubMed1998

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.

Animals↗
PubMed1998

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.

Animals↗
PubMed1997

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.

Amino Acid Sequence↗