The treatment of patients with infected implantable cardioverter-defibrillator systems

OBJECTIVE

The purpose of this study was to evaluate the treatment of patients with infected implantable cardioverter-defibrillator systems.

METHODS

Retrospective analysis was done of the cases of 21 patients treated for implantable cardioverter-defibrillator infection during an 11-year period.

RESULTS

Of 723 cardioverter-defibrillator implantations (550 primary implants, 173 replacements), nine (1.2%) were complicated by early postoperative device-related infections. Late infections developed in two patients 19 and 22 months, respectively, after implantation. Ten other patients were transferred to our institution for treatment of cardioverter-defibrillator infection. The time from implantation to overt infection was 2.2 +/- 1.3 months, excluding the two late infections. The responsible organisms were Staphylococcus aureus (9), Staphylococcus epidermidis (6), Streptococcus hemolyticus (1), gram-negative bacteria (3), Candida albicans (1), and Corynebacterium (1). All patients were treated with intravenous antibiotic drugs. Total system removal was done in 15 patients and partial removal in 2; in 4, the cardioverter-defibrillator system was not explanted. There were no perioperative deaths. A new implantable cardioverter-defibrillator system was reimplanted in 7 patients after 2 to 6 weeks of antibiotic therapy. Ten patients were treated without reimplantation (2 arrhythmia operation, 8 antiarrhythmic drugs). Four patients (3 patients without explantation and 1 with partial system removal) were treated with maintenance long-term antibiotic therapy. During a mean follow-up of 21 +/- 2.8 months, no patient had clinical recurrence of infection. One patient treated with antiarrhythmic drugs without system reimplantation died suddenly.

CONCLUSIONS

Infections that involve implantable cardioverter-defibrillator systems can be safely managed by removing the entire system with reimplantation after intravenous antibiotic therapy. In selected patients in whom the risk for system explantation is high and anticipated life expectancy is short, long-term antibiotic therapy to suppress low-virulence infections may represent an acceptable alternative.

Phylogenetic analysis of Opisthadena (Digenea:Hemiuridae)

Systematic study of the closely related hemiurid genera Mitrostoma, Neopisthadena and Opisthadena revealed that Opisthadena cortesi is a junior synonym of Opisthadena dimidia and Opisthadena fujianensis and Opisthadena marina are species inquirendae. Phylogenetic analysis of the 7 recognized species, based on 21 transformation series derived from comparative morphologic characters, produced a single tree with a consistency index of 0.735. The five species of the genus Opisthadena constitute a monophyletic clade and Neopisthadena habei is their sister group. Mitrostoma nototheniae is the sister group of the other 6 members of the clade. Geographic distribution suggests an ancient circum-Pacific distribution of the group. The association between kyphosids and this group of hemiurids appeared with the ancestor of Neopisthadena and Opisthadena.

A new species of Acanthobothrium van Beneden, 1849 (Eucestoda:Tetraphyllidea: Onchobothriidae) in Dasyatis longus Garman (Chondrichthyes:Myliobatiformes:Dasyatididae) from Chamela Bay, Jalisco, Mexico

A new species of Acanthobothrium in Dasyatis longus from Chamela Bay, Jalisco, Mexico, is a member of a presumed clade of species diagnosed by being anapolytic or nearly so, having more than 100 testes per proglottis, with immature and mature proglottides wider than long to square, aspinose scolex, muscular bothridia fused to the scolex at their posterior ends, H- to V -shaped ovaries, relatively short symmetrical to asymmetrical ovarian arms that extend anteriorly to, or nearly to, the cirrus sac, and vitellaria arranged in fields rather than a single row of follicles. The new species most closely resembles Acanthobothrium terezae from the freshwater stingray Potamotrygon motoro in the following characters: bothridial hooks longer than 200 microns with inner hooks having bent asymmetrical prongs, an average of 130-140 testes per proglottis, and shallow genital atria located posterior to midline of proglottis. The new species differs from A. terezae by having outer hooks approximately the same size and shape as the inner hooks, inner hooks averaging 230 microns rather than 313 microns in total length, and cirrus sacs averaging 255 microns rather than 450 microns in length. The new species is unique among all described species of Acanthobothrium by having a cleft in the posterior margin of each apical bothridial pad. The apparent close relationship of the new species to one inhabiting a Neotropical freshwater stingray provides support for the hypothesized Pacific marine ancestry of Neotropical freshwater stingrays and raises the possibility that the Neotropical freshwater stingrays may not be monophyletic.

Two new species of tetraphyllidean cestodes in Himantura pacifica (Chondrichthyes: Myliobatiformes: Dasyatididae) from the northwest coast of Costa Rica

Two new species of tetraphyllidean cestodes inhabiting Himantura pacifica from the northwest coast of Costa Rica are apparently most closely related to species inhabiting Himantura schmardae from the Atlantic coast of Colombia. Acanthobothroides pacificus n. sp. differs from Acanthobothroides thorsoni, the only other species in the genus, primarily by having smaller lateral (98-123 microns rather than 168-198 microns long) and medial (handles 92-116 microns rather than 162-168 microns long) hooks, and more testes (up to 125 rather than up to 97) per proglottis. The generic diagnosis of Acanthobothroides is modified to include the presence of a small inner prong on the large medial bothridial hooks. Rhinebothrium geminum n. sp. and Rhinebothrium magniphallum are the only 2 species in the genus possessing unusually long cirrus sacs, extending from the genital atrium all the way to the ovarian isthmus; R. geminum averages 12 (12-14) loculi per bothridium and 11 (9-12) testes, whereas R. magniphallum averages 17 (16-18) loculi and 14 (10-16) testes per proglottis.

Work-related injuries to Massachusetts teens, 1987-1990

This study uses workers' compensation data to describe the work-related injury experience of Massachusetts teens, ages 14-17, from 1987 to 1990. During this period, 2,551 injuries were reported to the workers' compensation system. Injuries were more frequent among 16-17 year-olds and among males. Sprains and strains, followed by lacerations, were the most frequent type of injury. Four industries--grocery stores, restaurants, health services, and department stores--accounted for over half of all injuries. The overall injury rate was 1.9/100 full-time equivalents (FTEs), but was higher in the construction, manufacturing, and wholesale trade sectors. Teens working in apparel manufacturing and nursing homes sustained the highest rate of injuries. Geographical analysis indicated that teens living in the southeast region of the state had the highest injury rates. This study adds to the existing evidence that work-related injuries to teens are a substantial public health problem.

Five new species of Acanthobothrium van Beneden, 1849 (Eucestoda: Tetraphyllidea: Onchobothriidae) in stingrays from 1he Gulf of Nicoya, Costa Rica

Five new species of Acanthobothrium are described in stingrays from the Gulf of Nicoya, Costa Rica. Acanthobothrium costarricense n. sp. in Dasyatis longus, most similar to Acanthobothrium lilium, Acanthobothrium lineatum, and Acanthobothrium himanturi, has bothridial hooks averaging 125 microns (lateral) and 145 microns (medial) long, an average of 47 testes per proglottis, cirrus sacs averaging 187 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the middle of the cirrus sac. Acanthobothrium cimari n. sp. in D. longus, most similar to A. lilium, A. lineatum, A. himanturi, A. costarricense, and Acanthobothrium semnovesiculum, has bothridial hooks averaging 117 microns (lateral) and 121 microns (medial) long, an average of 50 testes per proglottis, cirrus sacs averaging 164 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the level of the vagina. Acanthobothrium puntarenasense n. sp. in D. longus, distinctive in having a very small scolex relative to the width of the cephalic peduncle similar to Acanthobothrium microcephalum, has bothridial hooks averaging 111 microns (lateral) and 117 microns (medial) long, an average of 50 testes per proglottis, cirrus sacs averaging 170 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the middle of the cirrus sac. Acanthobothrium vargosi in D. longus, most similar to Acanthobothrium brevissime, Acanthobothrium tasajerasi, Acanthobothrium urotrygoni, and Acanthobothrium campbelli, has bothridial hooks averaging 130 microns (lateral) and 133 microns (medial) long, an average of 25 testes per proglottis arranged in 2 single rows, cirrus sacs averaging 91 microns long, and asymmetrical ovarian lobes with poral lobes reaching the posterior margin of the cirrus sac, and aporal lobes reaching the middle of the cirrus sac. Acanthobothrium campbelli n. sp. in Urotrygon chilensis, most similar to a A. brevissime, A. Vargasi, A. lineatum, A. himanturi, and A. urotrygoni, has bothridial hooks averaging 108 microns (lateral) and 111 microns (medial) long, an average of 19 tester per proglottis arranged in 2 nearly linear rows, cirrus sacs averaging 74 microns long, and asymmetrical ovarian lobes with the poral lobe reaching the posterior margin of the cirrus sac, and the aporal lobes reaching the middle of the cirrus sac.

Proteocephalus chamelensis n. sp. (Cestoda: Proteocephalidae) from the "guavina" Gobiomorus maculatus (Osteichthyes: Eleotrididae) in Chamela Bay, Jalisco, México

A new species of Proteocephalus inhabiting the eleotridid estuarine fish Gobiomorus maculatus is described from Chamela Bay, Jalisco State, Mexico. The new species and P. pugetensis are nearly identical in strobila length, presence of a vestigial apical organ, having vaginae only anterior to the cirrus sac, an average of 4-7 uterine diverticula per proglottis, and a ratio of cirrus sac length to proglottis width averaging approximately 1:4. Proteocephalus pugetensis differs from the new species by having an average of 35 rather than 68 testes per proglottis, vitelline follicles terminating posteriorly at the level of the anterior margin of the ovary rather than at the level of the posterior margin, and equatorial genital pores rather than genital pores located in the anterior 1/4 of the proglottis. Finally, Proteocephalus pugetensis occurs from estuarine habitats along the Pacific coast of the United States; the new species was collected from an estuarine habitat on the Pacific coast of México.

Limitations and late complications of third-generation automatic cardioverter-defibrillators

BACKGROUND

This study examines the limitations and complex management problems associated with the use of tiered-therapy, implantable cardioverter-defibrillators (ICDs).

METHODS AND RESULTS

The study group comprises the first 154 patients undergoing implantation of tiered-therapy ICDs at our institution. Pulse generators from three different manufacturers were used. In 39 patients, a complete nonthoracotomy lead system was used. The perioperative mortality was 1.3%. Of these 154 patients, 37% experienced late postoperative problems. Twenty-one patients required system revision within 36.5 months (mean, 8.57 +/- 11.3) of surgery. Reasons for revision were spurious shocks due to electrode fractures (3) or electrode adapter malfunction (2), inadequate signal from endocardial rate-sensing electrodes (3), superior vena cava or right ventricular coil migration (5), failure to correct tachyarrhythmias due to a postimplant rise in defibrillation threshold (5), or pulse generator failure (3). One of these patients required system removal for infection after revision of an endocardial lead. A further 32 patients received inappropriate shocks for atrial fibrillation with a rapid ventricular response or sinus tachycardia. Two of these patients also received shocks for ventricular tachycardia initiated by antitachycardia pacing triggered by atrial fibrillation. Ventricular pacing for bradycardia was associated with inappropriate shocks due to excessive autogain in 2 patients.

CONCLUSIONS

Despite the major diagnostic and therapeutic advantages of tiered-therapy ICDs, a significant proportion of patients continue to experience hardware-related complications or receive inappropriate shocks.

Acanthobothrium nicoyaense n. sp. (Eucestoda: Tetraphyllidea: Onchobothriidae) in Aetobatus narinari (Euphrasen) (Chondrichthyes: Myliobatiformes: Myliobatidae) from the Gulf of Nicoya, Costa Rica

A new species of Acanthobothrium in Aetobatus narinari from the Gulf of Nicoya, Costa Rica, most closely resembles Acanthobothrium colombianum in the same host and A. urotrygoni in Urotrygon venezuelae from Cartagena, Colombia, by having relatively few proglottides per strobila, spinose cephalic peduncles, bothridial margins free at their posterior ends, and irregularly shaped rather than spherical or elongate cirrus sacs. Acanthobothrium colombianum differs from the new species by being as much as 35 mm rather than no more than 4.7 mm long and by having 31-48 rather than 13-19 proglottides, an average of 46 rather than 15 testes per proglottis, and bothridial hooks averaging 185 microns rather than 137 microns in total length. Acanthobothrium urotrygoni differs from the new species by being as much as 15 mm rather than no more than 4.7 mm long and by having V-shaped rather than H-shaped ovaries, bothridial hooks averaging 95 microns rather than 137 microns in total length, by having an average of 28 rather than 15 testes per proglottis, and by having poral ovarian arms extending anteriorly to the posterior margin of the cirrus sac and aporal arms extending to the lateral margin of the cirrus sac.

Phylogenetic relationships among the species of Pyelosomum Looss, 1899 (Digenea: Pronocephalidae)

Comparative morphological study of 10 nominal species of pronocephalids forming a clade diagnosed by plump rounded bodies, sinuous ceca, and short esophagi supports the recognition of 7 species, with Pyelosomum longicaecum a junior synonym of P. renicapite, and P. solum and Myosaccus chelonei species incertae sedis. Phylogenetic analysis of the 7 recognized species, based on 18 morphological transformation series, produced a single tree with a consistency index of 86%. That tree suggests that Pyelosomum is paraphyletic unless Astrorchis, Epibathra, and Myosaccus are included in it. Accordingly, all are considered junior synonyms of Pyelosomum. Epibathra stenobursata is designated Pyelosomum stenobursata comb. n.

Phylogenetic relationships of the genera of the Pronocephalidae Looss, 1902 (Digenea: Paramphistomiformes)

Quantitative phylogenetic analysis of 20 nominal genera of the Pronocephalidae based on 47 morphological transformation series produced 6 equally parsimonious trees, each with a consistency index of 77.8%. All trees agree that Adenogaster is the sister group to the rest of the pronocephalids, and a new subfamily is proposed for it. The Pronocephalinae comprises Pronocephalus, Ruicephalus, Neopronocephalus, Macravestibulum, Choanophorus, Cetiosaccus, and Metacetabulum. The Charaxicephalinae comprises Charaxicephalus, Desmogonius, Diaschistorchis, Pleurogonius, Iguanacola, Renigonius, Parapleurogonius, Himasomum, Pyelosomum, Cricocephalus, Barisomum, and Pseudobarisomum. An amended diagnosis for Himasomum is presented. The trees differ only in the placements of Pleurogonius, Renigonius + Parapleurogonius, Iguanacola, and Himasomum relative to each other. Parapronocephalum and Notocotyloides are members of the clade containing the Notocotylidae. The phylogenetic tree supports interpretations of 3-4 transitions from marine to freshwater turtles, 3 host switches from marine turtles to the Galapagos marine iguana and 3 from marine turtles to the French angelfish, and widespread host switching among marine chelonians. No switches to non-chelonian hosts coincide with transitions from marine to freshwater.

A mutation-specific PCR system to detect sequence variation in the dihydropteroate synthetase gene of Plasmodium falciparum

Sulphur-based antimalarial drugs targeted at dihydropteroate synthetase (DHPS) are frequently used in synergistic combination with inhibitors of dihydrofolate reductase (DHFR) to combat chloroquine-resistant malaria. We have previously shown that lines of Plasmodium falciparum resistant to the most commonly used sulpha drug, sulphadoxine, carry point mutations in the DHPS coding region, relative to the sequence of sensitive strains (Brooks et al., Eur. J. Biochem. 224 (1994) 397-405). We have now developed PCR diagnostic assays based on allele-specific amplification that are able to detect such mutations. The four tests described can reliably discriminate all of the mutations observed to alter codons 436, 581 and 613, yielding allele-specific amplification products of different sizes in each case. Moreover, by careful adjustment of primer length and the degree of mismatch to target and non-target alleles, we were able to standardise all four tests to a single set of PCR conditions, allowing all possible mutations to be monitored simultaneously on one thermocycler. These assays should prove invaluable in further assessing the contribution of specific base changes in the DHPS gene of the parasite to the sulphadoxine resistance phenotype and to the clinical failure of the sulphadoxine/pyrimethamine combination Fansidar.

Serendip deborahae n. gen. and n. sp. (Eucestoda: Tetraphyllidea: Serendipidae n. fam.) in Rhinoptera steindachneri Evermann and Jenkins, 1891 (Chondrichthyes: Myliobatiformes: Myliobatidae) from southeastern Ecuador

Cestodes collected in spiral valves of Rhinoptera steindachneri from the southern coast of Ecuador represent an undescribed species of Tetraphyllidea. The new species has bothridia possessing septa but lacking apical suckers. It is diagnosably distinct from all other tetraphyllidean genera by possessing a scolex comprising 4 triangular bothridia that are fused together forming a platelike structure, each of which is subdivided by 2 simple and 1 bifurcating septa radiating from its base and ringed by marginal loculi; therefore, a new genus is proposed for it. By exhibiting some degree of bothridial fusion, testes arranged in 2 layers in the proglottis and postovarian testes, the new species appears to be a member of a clade containing Dioecotaenia, Duplicibothrium, and Glyphobothrium. The new species possesses vitelline fields that converge dorsally in each proglottis, except for the ovarian and terminal genitalia areas, a feature that has been reported previously only in Duplicibothrium and Glyphobothrium. Furthermore, Duplicibothrium and Glyphobothrium, like the new species, are markedly protandric. Therefore, we propose that Duplicibothrium, Glyphobothrium, and the new species comprise the sister group of the Dioecotaeniidae, and propose a new family name for the clade. Tritaphros is rejected as a possible sister group for the clade; suggested alternatives include some species of Caulobothrium, Rhodobothrium, or some members of the Phyllobothrium centrurum group.

Escherbothrium molinae n. gen. et n. sp. (Eucestoda: Tetraphyllidea: Triloculariidae) in Urotrygon chilensis (Chondrichthyes: Myliobatiformes: Urolophidae) from the Gulf of Nicoya, Costa Rica

Cestodes collected in spiral valves of the stingray Urotrygon chilensis from the Pacific coast of Costa Rica represent an undescribed species of Tetraphyllidea. By possessing more than 2 loculi as well as an apical sucker on each bothridium, the new species is diagnosably distinct from all other tetraphyllidean genera; therefore, a new genus is proposed for it. The new species also possesses globular structures irregularly arranged on the surface of the bothridia. We found similar structures on the bothridial faces of Trilocularia acanthiaevulgaris, possibly indicating phylogenetic relationships with the new species. This possibility is enhanced by the observation that the bothridia of T. acanthiaevulgaris comprise 2 loculi and an apical sucker, rather than 3 loculi.

Sequence variation of the hydroxymethyldihydropterin pyrophosphokinase: dihydropteroate synthase gene in lines of the human malaria parasite, Plasmodium falciparum, with differing resistance to sulfadoxine

Dihydropteroate synthase (H2Pte synthase) is the target of the sulfur-based antimalarial drugs, which are frequently used in synergistic combination with inhibitors of dihydrofolate reductase (H2folate reductase) to combat chloroquine-resistant malaria. We have isolated the H2Pte synthase coding sequence of the most pathogenic human parasite Plasmodium falciparum. It forms part of a longer coding sequence, located on chromosome 8, that also specifies 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (CH2OH-H2pterinPP kinase) at its 5' proximal end. This domain is unusually large, with two long insertions relative to other CH2OH-H2pterinPP kinase molecules. To investigate a possible genetic basis for clinical resistance to sulfa drugs, we sequenced the complete H2Pte synthase domains from eleven isolates of P. falciparum with diverse geographical origins and levels of sulfadoxine resistance. Overall, point mutations in five positions were observed, affecting four codons. Parasite lines exhibiting high-level resistance were found to carry either a double mutation, altering both Ser436 and Ala613, or a single mutation affecting Ala581. The mutations at positions 436 and 581 have the same location relative to each of two degenerate repeated amino acid motifs that are conserved across all other known H2Pte synthase molecules. The amino acid alteration at residue 613 is identically positioned relative to a different conserved motif. The fourth amino acid residue (437) affected by mutation, though adjacent to the apparently crucial residue 436, shows no obvious correlation with resistance. Although these mutations have no exact counterparts in any other organism, that at position 581 falls within a region of three amino acids where H2Pte synthase is modified in various ways in a number of sulfonamide-resistant pathogenic bacteria. Copy-number analysis indicated that there was no amplification of the H2Pte synthase domain in resistant parasite lines of P. falciparum, compared to sensitive lines.

Elevated blood lead levels among construction workers in the Massachusetts Occupational Lead Registry

Although the construction industry until recently was exempt from the Occupational Health and Safety Administration General Industry Lead Standard, including its medical monitoring provisions, periodic blood lead tests have been required for residential "deleaders" and structural painters in Massachusetts. Sixty-three percent of the 381 registrants in the Massachusetts Occupational Lead Registry with blood lead levels of 1.93 mumol/L or higher are construction workers. This proportion is much higher than that reported by registries of several states selected for comparison. These data highlight the need for better protection from lead exposure and the effectiveness of mandatory medical surveillance in identifying elevated blood lead levels among construction workers.

Work-related injuries among Massachusetts children: a study based on emergency department data

Millions of children in the United States work and, despite federal and state laws, face safety hazards. Previous studies have documented large numbers of injuries suffered on the job by working children. This study describes work-related injuries to children 14-17 years old in 14 Massachusetts communities (representing 5% of the state population) based on data from emergency departments and hospital admissions collected as part of a large population-based surveillance study of injuries to children and adolescents from 1979 to 1982. An estimated 1,176 work-related injuries occurred during the three-year period, accounting for 7-13% of all injury-related emergency department visits in this age group; the proportion among 17-year-olds was 14-26%. Cuts and lacerations were the most frequent type of injury, cutting/piercing was the most common cause, and cutting instruments were the most frequently identified products. Seventeen children were hospitalized for work-related injuries during the course of the study. The estimated annual rate of occupational injury rose from 3.7/1,000 children for 14- to 15-year-olds to 44.7/1000 for 17-year-olds; these rates count all resident children, regardless of their employment status, in the denominator. Rates based on actual hours worked are much higher, and strongly suggest that working minors should be considered a high-risk group for occupational injury. This study adds to the mounting evidence that work-related injuries to children are a significant public health problem and contribute significantly to the overall incidence of injuries among children 14-17 years old. The study also demonstrates the potential of emergency department data as a valuable source of information about work-related injuries to children. Active surveillance systems combining data from emergency departments, workers' compensation, and other potential sources should be established to fully document the nature and extent of the problem. Efforts to prevent these injuries will require the combined attention of employers, parents, medical providers, educators and regulators, as well as working children themselves.

Some Platyhelminths inhabiting white-throated sparrows, Zonotrichia albicollis (Aves: Emberizidae: Emberizinae), from Algonquin Park, Ontario, Canada

Twenty-two of 26 white-throated sparrows, Zonotrichia albicollis, from Algonquin Park, Ontario, Canada, hosted 1 or 2 species of platyhelminths. One species of cestode and 3 of digeneans were collected. Anonchotaenia quiscali inhabited 50% of the sparrows. This is the third report of A. quiscali; Z. albicollis is a new host. Brachylecithum nanum inhabited 43%, Zonorchis alveyi 15%, and Prosthogonimus macrorchis 8% of the sparrows examined. Ontario is a new geographic distribution record from all 4 parasite species. The proportion of hosts infected with 2 species was not significantly different from expected based on single species prevalences, indicating that there is no competitive interaction among these species of parasites for access to the avian hosts.

Origins, diversification, and historical structure of the helminth fauna inhabiting neotropical freshwater stingrays (Potamotrygonidae)

Members of the freshwater stingray family Potamotrygonidae occur throughout the major river systems of eastern South America that empty into the Atlantic Ocean. Ichthyologists have tended to assume that the ancestor of the potamotrygonids was an Atlantic marine or euryhaline stingray that dispersed into freshwater, presumably during the last marine ingression 3-5 million years ago. The helminth parasites that inhabit potamotrygonids suggest an alternative perspective on their origin. Phylogenetic and biogeographic analysis of the helminths inhabiting potamotrygonids suggest that the hosts are derived from an ancestral Pacific urolophid stingray that was trapped in freshwater by the uplifting of the Andes beginning perhaps as early as the early Cretaceous period and ending by the mid-Miocene epoch, changing the course of the Amazon River, which previously had flowed into the Pacific Ocean.

Cestode parasites in Potamotrygon motoro (Natterer) (Chondrichthyes: Potamotrygonidae) from southwestern Brazil, including Rhinebothroides mclennanae n. sp. (Tetraphyllidea: Phyllobothriidae), and a revised host-parasite checklist for helminths inhabiting neotropical freshwater stingrays

Specimens of 5 species of cestodes were collected in 6 specimens of the freshwater stingray species Potamotrygon motoro (Natterer), collected in the vicinity of Corumba, Mato Grosso do Sul, Brazil. Acanthobothrium regoi, Potamotrygonocestus orinocoensis, Rhinebothroides venezuelensis, and Rhinebothrium paratrygoni are reported from P. motoro and from southwestern Brazil for the first time. Rhinebothroides mclennanae n. sp. appears to be the sister species of Rhinebothroides glandularis, the only other member of the genus exhibiting darkly staining glandular cells lying free in the parenchyma surrounding the terminal genitalia. The new species resembles Rhinebothroides glandularis, Rhinebothroides freitasi, and Rhinebothroides scorzai by having poral ovarian arms that extend anteriorly beyond the posterior margin of the cirrus sac, coiled vaginae, and vitelline follicles not interrupted on the poral side in the vicinity of the genital pore. It differs from all 6 previously described members of the genus by possessing an average of 31 testes per proglottid, compared with an average of 45 for R. glandularis, 55 for R. freitasi and R. venezuelensis, 77 for Rhinebothroides circularisi and Rhinebothroides moralarai, and 80 for R. scorzai. An updated phylogenetic tree for Rhinebothroides is presented.

Occupation, smoking, and the risk of high-grade invasive bladder cancer in Missouri

Numerous epidemiological studies have established that occupational exposures and smoking are the two major known risk factors for the development of bladder cancer. Using data from the Missouri Cancer Registry, we investigated the hypothesis that individuals with occupationally-related bladder cancer are more likely to have a more invasive form of the disease. Data were analyzed for 2,893 white males diagnosed with primary bladder cancer in Missouri between 1984 and 1988. Of the 1,415 cases whose occupational status was recorded, 236 (17%) were employed in high-risk occupations. Cases with high-grade disease were more likely to have been employed in a high-risk occupation, after adjustment for age and smoking (adjusted odds ratio [AOR] = 1.7, 95% confidence interval [CI] = 1.1-2.6). High-risk workers under 60 years of age were most at risk for developing high-grade bladder tumors (AOR = 2.3, 95% CI = 1.0-5.3). There was no overall association between high-risk occupation and late-stage disease (AOR = 1.1, 95% CI = 0.7-1.5), but it was present in the men younger than 60 years of age (AOR = 2.0, 95% CI = 1.0-3.8). No association was found between tobacco use and grade (AOR = 1.1, 95% CI = 0.8-1.5), but cases with late-stage disease were more likely to be smokers (AOR = 1.5, 95% CI = 1.1-1.9). When occupations were examined individually, motor vehicle operators, truck drivers, vehicle mechanics, other mechanics, and janitors were among those most likely to be diagnosed with high-grade or late-stage tumors. Although further studies are necessary to confirm these results, they suggest that surveillance and targeted screening of workers in high-risk occupations may result in a greater yield of early invasive cancers and possibly decrease the mortality associated with this disease.