Entire-volume serial histological examination for detection of micrometastases in lymph nodes of colorectal cancers.

The purpose of this study was to accurately detect lymph-node micrometastases, i.e., metastatic cancer foci that have a size between 2.0 and 0.2 mm, in nodes excised from colorectal cancer (CRC) patients, and to determine how frequently micrometastases might be missed when standard histological examination procedures are used. A total of 311 lymph nodes were removed and examined from 90 patients with Stage I to IV CRC. The number of slices of histology sections ranged from 6 to 75 per node (average = 25.5; SD = 11.1), which provided a total of 7,943 slices. Lymph nodes were examined in their entire volume at every 50-µm and 100-µm intervals for nodes smaller and larger than 5 mm respectively. The total number of thin sections examined in each node and the number of thin sections where metastatic foci were present were counted. The number of thin sections with metastatic foci and the total number of slices was determined for each node. In addition, the presence or absence of metastatic foci in the "central" slice was determined. Micrometastases were found in 12/311 (3.9%) of all lymph nodes. In the 12 lymph nodes with micrometastases, the rate of metastatic slices over all slices was 39.4% (range = 6.3 to 81.3%; SD = 25.8%) In the central slice of each node, micrometastases were present only in 6 of 12 lymph nodes (50%); accordingly, they were not present in the central slice for half the micrometastatic nodes. These 6 nodes represented 1.9% of the 311 nodes and 11.1% of the 54 metastatic nodes. This study suggests that a significant fraction of micrometastases can be missed by traditional singleslice sectioning; half of the micrometastases would have been overlooked in our data set of 311 nodes.

Can the needs of the critically ill child be identified using scenarios? Experiences of a modified Delphi study.

The Delphi technique enables the structuring of group opinion and discussion using a survey approach, maintaining the anonymity of panel members and preventing contamination of individual responses through peer pressure. The Delphi technique was used by the authors to form an expert opinion regarding the needs of a critically ill child. The abstract and evaluative nature of need was a key issue to arise during early pilot work and stimulated the first author to undertake a concept analysis of the term 'need'. The defining attributes arising from the concept analysis were used to construct two hypothetical case studies for the modified Delphi; these were used as part of the questionnaire for all three rounds. In the first round, the panel was asked to identify the needs of the child in the two case studies; in subsequent rounds the panel activity involved modifying these need statements and indicating the importance, frequency and maximum acceptable delay in meeting each need. Extensive pilot work was required for each round of the modified Delphi. This article evaluates the use of this technique to identify needs, discusses key features arising from the results and examines the difficulties experienced by the respondents in completing the time scales.

Mechanisms of global support and posttraumatic enophthalmos: I. The anatomy of the ligament sling and its relation to intramuscular cone orbital fat.

The mechanisms of posttraumatic enophthalmos were evaluated to determine the interrelation between fat and ligaments in globe support. Anatomic studies demonstrate that the ligaments form an essential "sling" framework for the globe but are alone insufficient to maintain the globe's full forward position. Removal of extramuscular fat in cadavers and in patients undergoing blepharoplasty did not significantly change globe position. Loss of intramuscular cone fat (atrophy or displacement) in cadavers and patients produced enophthalmos. Fat atrophy is not a prominent feature in most patients with posttraumatic enophthalmos. Some loss of intramuscular cone fat from displacement outside the muscle cone is frequently present. The principal mechanism, however, of posttraumatic enophthalmos involves a displacement and change in the shape of orbital soft tissue. Loss of bone and ligament support permits posterior displacement and a reshaping of orbital soft tissue under the influence of gravity and the remodeling forces of fibrous scar contracture. The shape of the retrobulbar orbital contents changes from a modified cone to a sphere, and the globe sinks backward and downward. Given that the volume of orbital soft tissue is constant following trauma, procedures to restore the shape and position of the orbital soft tissue by mobilization and bone reconstruction will correct or significantly improve enophthalmos.

The Haller's organ roof and anterior pit setae of Argas ticks (Ixodoidea: Argasidae). Subgenera Secretargas and Ogadenus.

Adults of the Argas subgenera Secretargas (3 species) and Ogadenus (1 species) were studied by scanning electron microscopy. In each species, the anterior pit and Haller's organ are situated in a large dorsal hump of Tarsus I and the 9 setae of the anterior pit are characteristic of the genus Argas in structure and numbers. In A. (S.) transgariepinus, an Ethiopian-Palearctic crevice-dwelling parasite of bats, the Haller's organ capsule roof is solid with a slitlike transverse aperture. In A. (S.) hoogstraali and A. (S.) echinops, Malagasy soil-dwelling parasites of Oplurus (Varanidae) lizards and the hedgehog-tenrec (Insectivora: Tenrecidae), respectively, the Haller's organ is virtually unroofed but partially screened by arborescent dorsal projections from the posterior wall of the capsule, and the open capsule contains numerous fine pleomorphs. In A. (O.) brumpti, a soil-dwelling parasite of the hyrax (Procavia), other terrestrial mammals, and lizards in the Ethiopian Region, the capsule is also virtually unroofed and contains numerous fine pleomorphs. The unroofed capsule is probably phylogenetically primitive and occurs only in these 3 and 2 other Argas species. The soil microhabitat (in Argas confined to 3 of the 4 species recorded here), and the reptile or ancient mammal hosts of these 3 species, as well as the zoogeographical isolation of 2 of the species in the Malagasy Region, are distinctive in this genus of 56 species. The interrelationships between an unroofed Haller's organ capsule and unusual biological properties remain to be determined.

Bat ticks of the genus Argas (Ixodoidea: Argasidae). 13. Haller's organ roof and anterior pit setae in Carios and Chiropterargas.

Adults of 4 of the 6 species constituting the subgenus Carios and of 3 of the 4 species constituting the subgenus Chiropterargas were studied by scanning electron microscopy. All species parasitize Old World cave-dwelling insectivorous bats (Microchiroptera). The anterior pit setae number 10 in Carios and 10 or 11 in Chiropterargas. In most Carios, the setiform seta is replaced by a second serrate seta. In 2 of the 3 studied Chiropterargas species, 1 of the 2 grooved setae is exceptionally long. Porose setae number 3 in Carios and 3 or 4 in Chiropterargas. The Haller's organ roof in both subgenera is solid, lacking perforations; the aperture is narrowly transverse in Carios, irregularly wide or wide and transverse in Chiropterargas; uniquely, 1 or 2 sensilla protrude from the aperture of Chiropterargas species. The protruding sensilla and long grooved seta of Chiropterargas suggest a probably distinctive sensory-behavior pattern common to these ticks. Other morphological characters are discussed and compared to show relationships between these 2 subgenera and the subgenera Argas and Persicargas and distinctive characters present only in adult and/or larval Carios and Chiropterargas.

The subgenus Persicargas (Ixodoidea: Argasidae: Argas). 38. Haller's organ roof and anterior pit setae in Persicargas and Microargas.

Adults of 13 of the 17 species constituting the subgenus Persicargas (parasitizing birds nesting in trees) and the single species of the subgenus Microargas (parasitizing the Galapagos giant tortoise) were studied by scanning electron microscopy. The setae of the anterior pit of tarsus I number nine(1 serrate, 1 setiform, 1 conical, 2 fine, 2 porose, 2 grooved) in Persicargas. The single, serrate seta arises from an anterior section of the pit, the other eight setae arise from a posterior section. Abnormally, fewer or more setae occur on one or both tarsi of a single specimen. The setal arrangement is similar in Microargas, but the total number is eight (setiform seta absent). The capsule roof of Haller's organ in Persicargas is typically flat and platelike with a circular central aperture and few to moderately numerous small perforations. Thus, this roof is more solid than in other subgenera of Argas, except in Microargas and subgenera associated with cave-dwelling bats (Carios and Chiropterargas). The roof structure is quite variable in samples of A. (P). radiatus. The roofs of two Persicargas species differ from the typical pattern, the A. (P.) minatus roof is more extensively perforated and in some specimens of A. (P.) streptopedia the roof is netlike. The Microargas roof, on a sloping surface bounded by a transverse anterior groove, is more solid than those of Argas and has a circular aperture surrounded by small perforations. The biological implications of these structural properties should be investigated.

Observations on the subgenus Argas (Ixodoidea: Argasidae: Argas). 18. Haller's organ roof and anterior pit setae.

Adults of 18 of the 22 species constituting the subgenus Argas, which parasitize birds nesting and resting in rocky habitats in each faunal region of the world (15 species) or in trees (e species) (2 Neotropical, 1 Nearctic), were studies by SEM. In each except three Neotropical species, the nine setae of the anterior pit of tarsus I are arranged in an anterior group (1 serrate, 1 setiform, 1 conical) and a posterior group (2 fine, e porose, 2 grooved), or the two groups are more or less confluent. Abnormally, additional setae may occur on one or both tarsi of a single specimen. In one Neotropical species, only the three anterior group setae are present. In three Neotropical species, only these three setae and a fourth seta are present (whether 6 or 5 additional setae are concealed within the tarsal structure should be investigated). The Haller's organ capsule is entirely open (unroofed) (3 species), roofed posteriorly and open anteriorly (7 species), or mostly roofed by a plate which is pierced by one large aperture and by more or less numerous, small, or medium-sized perforations (8 species plus one other not studied by use). This study suggests that the structure of Haller's organ has evolved in different lines in response to a multiplicity of biologic al factors related to the behavior and habitat of individual species.

Clarification of the status of Rhipicephalus kochi Dönitz, 1905 (Ixodoidea, Ixodidae).

Figures of the types of Rhipicephalus kochi, and of its synonym Rhipicephalus neavei Warburton, 1912, are presented. These are accompanied by complete descriptions of all stages of R. kochi, illustrated with scanning electron microscope photographs. The basic differences between this species, Rhipicephalus pravus Dönitz, 1910 and Rhipicephalus punctatus Warburton, 1912 are outlined. R. kochi occurs south of the Equator in parts of eastern, central and southern Africa. Its adults feed most commonly on cattle, various antelopes and wild pigs, and on hares. Little is known about the hosts of the immature stages; nymphae have been recorded in a field collection once only, from Petrodromus tetradactylus, the 4-toed elephant shrew.

Isolation and characterization of Midway virus: a new tick-borne virus related to Nyamanini.

Midway virus, a new tick-borne virus isolated from two species of Ornithodoros (Alectorobius) ticks of the capensis group (O capensis, O denmarki), is described from Midway, Kure, and Manana islands in the Central Pacific (Hawaiian Archipelago) and from northern Honshu (Japan). Midway virion is enveloped, unusually large, acid and temperature sensitive, and its type of nucleic acid is RNA. Complement-fixation (CF) tests show a close relation of Midway to Nyamanini virus, which has been isolated from ardeid birds and Argas ticks in Africa, the Indian subcontinent, and Southeastern Asia. However, cross-box tests (CF, mouse and tissue culture neutralization, immunofluorescence) show that these two viruses are quite distinct. Midway virus is lethal for newborn Swiss mice inoculated by intracerebral, but not intraperitoneal route. It fails to kill four-week-old mice by either route. Midway virus causes cytopathic effects in BHK-21 cells and titerable plaques in Vero cells. Antibodies to it were prevalent among nestlings of Larus crassirostris (Black-tailed Gull) on Aomatsushima I., but were scarce among those of Nycticorax nycticorax (Black-crowned Night Heron) of the same island.

Ixodes (Afrixodes) matopi n. sp. (Acarina: Ixodidae): a tick found aggregating on pre-orbital gland scent marks of the klipspringer in Zimbabwe.

Ixodes (Afrixodes) matopi n. sp. is described from females and males collected off twigs bearing deposits of intraspecific communication marks secreted by the pre-orbital glands of the klipspringer Oreotragus oreotragus and from laboratory-reared immature specimens. One female was also found on a goat. The 4 collections were all from Zimbabwe, 3 of them from Matabeleland South Province and the fourth from Inyanga District, Zimbabwe.

Ornithodoros (alectorobius) amblus (Acarina: Ixodoidea: Argasidae): identity, marine bird and human hosts, virus infections, and distribution in Peru.

Ornithodoros (Alectorobius) amblus Chamberlin 1920, adults previously were described inadequately. Practically nothing was known regarding the identity, hosts, distribution, and biology of this species. We redescribe both sexes, describe the nymph and larva, and present criteria for differentiating these stages from those of other members of the O. (A.) capensis group in the Western Hemisphere. Samples were collected from 13 localities on the Pacific coast and on offshore islands of Peru. Hosts recorded are the Peruvian Brown Pelican, Peruvian Booby, Blue-footed Booby, Red-legged Cormorant, Guanay Cormorant, and Inca Tern. These birds are not long-distance migrants and more widely distributed species of the O. (A.) capensis group have not been found parasitizing them. The life cycle is characteristic of the O. (A.) capensis group; the first nymphal instar does or does not feed. Humans are attacked eagerly by O. (A.) amblus and suffer afterward from severe inflammation and "incredible" pruritus, and possibly from more severe illness. Viruses infecting this tick are Punta Salinas (Hughes serogroup, family unclassified) and Huacho (Reoviridae, genus Orbivirus, Kemerovo serogroup). Dense tick populations cause breeding birds to desert numerous nests; thus, O. (A.) amblus is economically important to the Peruvian guano industry. Certain spiders and lizards may prey on this tick.