A technique for visual confirmation of intrathoracic placement of tube thoracostomy using a fiberoptic laryngoscope in a cadaver.

PURPOSE: Safe intrathoracic placement of chest tubes is a continual challenge. Current techniques for determining the intrathoracic location of the thoracostomy site include blunt dissection and digital exploration, with subsequent tube placement. Using current techniques, complication rates for this procedure approach 30%. We present a novel technique using available endotracheal intubation technology for determining intrathoracic placement of tube thoracostomy. METHODS: One cadaver was used for placement of tube thoracostomy. Both sides of the thorax were prepared in the standard fashion for tube thoracostomy placement, and tube thoracostomy was performed on each hemithorax at interspaces 3 through 7. The right side of the thorax was used for standard thoracostomy placement, and the left side was used for fiberoptic visualization of thoracostomy placement using a video laryngoscope. Thoracic wall thickness was measured at all thoracostomy sites. Proper placement and any injuries were documented for each site. RESULTS: Chest wall thickness ranged from 2.4 to 3.8 cm on the right and 2.8 to 4.0 cm on the left. With use of fiberoptic thoracostomy, no injuries were generated. During the standard thoracostomy placement in the sixth intercostal space, a pulmonary laceration was caused using blunt dissection. CONCLUSIONS: Use of a fiberoptic laryngoscope offers a novel technique for direct visualization the thoracic space during tube thoracostomy. Further studies are needed to determine the safety of this technique in patients.

Fine structure and sugar transport functions of the tegument in Clinostomum marginatum (Digenea: Clinostomatidae): environmental effects on the adult phenotype.

Digenean flukes can be classified into 3 groups according to their location in the host: the lumen of the alimentary canal or associated organ, body cavity or tissue, and external surfaces. We obtained adults of Clinostomum marginatum that had matured in these 3 habitats and compared the fine structure and glucose transporting capacity of their teguments. Adults from the esophagus of herons, Ardea herodias, had thick, smooth teguments and took up glucose by facilitated diffusion, the type of transport that is Na(+)-independent and insensitive to phlorizin. By contrast, the surfaces of adults cultured from metacercariae in body cavities of laboratory mice were amplified 3-5-fold due to numerous irregular projections of the tegument. Glucose transport by these worms was largely Na(+)-dependent and inhibited by phlorizin, indicating active transport. Ectoparasites from herons' mouths had relatively thick, smooth teguments, but these worms always were encrusted with bacteria and yeast that are known to absorb and metabolize glucose. Most of the attached bacteria, and the apparent glucose uptake associated with their presence, were removed by treating the worms with antibiotics prior to transport assays. As facilitated diffusion and active transport are operational simultaneously in metacercariae, the type of transport function, if any, expressed in the adult is determined by environmental conditions associated with the worm's habitat.

Bacteria associated with tegument of Clinostomum marginatum (Digenea).

Adults of Clinostomum marginatum freshly collected from a heron, Ardea herodias, were examined using transmission electron microscopy. Specimens from the mouth of the bird were encrusted with bacteria that were not removed by washing unless the saline contained antibiotics. There was no evidence that the attached bacteria were damaging to the trematode tegument. Three species of Gram-negative bacteria were isolated from the worm surfaces and identified; Achromobacter sp. was present in pure culture on 4 of 6 original cultures and in mixed culture with Edwardsiella tarda and Enterobacter agglomerans in 2 cultures. These species and 3 unidentified species of bacteria were isolated from the oral epithelium of the heron. Microorganisms were not seen attached to the surfaces of worms recovered from the esophagus. Because E. tarda and E. agglomerans were the only species isolated from the heron esophagus, the intimate bacterial-worm association in the heron mouth may be due specifically to Achromobacter sp.

COMPARATIVE POPULATION GENETIC STRUCTURE OF A PARASITE (FASCIOLOIDES MAGNA) AND ITS DEFINITIVE HOST.

The population genetic structure of the American liver fluke, Fascioloides magna, and its definitive host the white-tailed deer, Odocoileus virginianus, was examined in South Carolina. Flukes were significantly more common in deer from river-swamp habitat than upland areas and prevalence increased with host age. The distribution of flukes among deer occurred as a negative binomial with the mean dispersion parameter, k, equal to 0.17 and the range from 0.10 to 1.11 within local areas. Significant spatial genetic differentiation was observed for flukes and deer. Patterns of genetic distance in flukes were not concordant with those of the definitive host nor were they related to geographic distance between sample locations. Spatial genetic differentiation among flukes reflected the tendency for individual hosts to harbor multiple individuals from a limited number of parasite clones. The large population size of the parasite and movements of the definitive host tend to counteract factors that lead to spatial differentiation.

Patterns in helminth communities in freshwater fish in Great Britain: alternative strategies for colonization.

Examples of the apparently stochastic nature of freshwater fish helminth communities illustrating the erratic and unpredictable occurrence and distribution of many species are provided for six species of fish from several localities throughout Britain. By focussing on parasite colonization strategies two categories of helminths are recognized: autogenic species which mature in fish and allogenic species which mature in vertebrates other than fish and have a greater colonization potential and ability. Three groups of fish are distinguished: salmonids, in which helminth communities are generally dominated by autogenic species which are also responsible for most of the similarity within and between localities; cyprinids, in which they are dominated by allogenic species which are also responsible for most of the similarity within and between localities; and anguillids, whose helminth communities exhibit intermediate features with neither category consistently dominating nor providing a clear pattern of similarity. Recognition and appreciation of the different colonization strategies of autogenic and allogenic helminths in respect of host vagility and ability to cross land or sea barriers and break down habitat isolation, and their period of residence in a locality, whether transient or permanent, provides an understanding of, and explanation for, the observed patchy spatial distribution of many helminths. Comparison with other parts of the world indicates that colonization is a major determinant of helminth community structure.

The parasite fauna of the American alligator (Alligator mississippiensis) in South Carolina.

Twelve American alligators (Alligator mississippiensis) were obtained from three different areas of South Carolina. One species of pentastome (Sebekia oxycephala), two species of nematodes (Dujardinascaris waltoni and Multicaecum tenuicolle), four species of trematodes (Polycotyle ornata, Acanthostomum coronarium, Archaeodiplostomum acetabulatum and Pseudocrocodilicola americaniense) and one species of hemogregarine (Haemogregarina crocodilnorum) were recovered. Polycotyle ornata was observed only in alligators from Par Pond while P. americaniense was found in Par Pond and coastal hosts, A. acetabulatum from Kiawah Island and coastal alligators, and A. coronarium only at Kiawah Island. These patterns suggest disjunct distributions for the trematode species in South Carolina alligators. The other parasites were found in alligators from all three locations. The only parasite observed to initiate damage or lesions in the alligator was the pentastome.