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A Virga

Publications and source records attributed to A Virga.

11 recordsLinked to original sources
PubMed1997

New record of Nosopsyllus (Nosopsyllus) barbarus (Jordan and Rothschild, 1912) (Aphaniptera: Dolichopsyllidae) from Sicily. Morphology at scanning electron microscopy of N. (N.) barbarus and N. (N.) fasciatus (Bosc D'Antic, 1800).

Nosopsyllus (N.) fasciatus, species or complex cosmopolitan and very polymorphic, is established in most of Italian regions, in association with murine rodents, especially domestic species. N. (N.) barbarus, similar to N. fasciatus in modified segments of the male and perhaps in ecology, is presently known from North Africa regions and a few Mediterranean islands; in Italy it is reported from Sardinia and Egadi islands. In this note the N. barbarus presence in Sicily (Palermo) and the contemporary record of N. fasciatus from the same country and host species (Rattus rattus frugivorus) are reported for the first time. The coexistence of both species was shown until now, only in Sardinia. A scanning electron microscope was used to describe the clasper of the male of N. fasciatus and the main diagnostic surface differences between females of N. fasciatus and N. barbarus.

Animals↗
PubMed1997

Research of canine filariasis in Trapani province (western Sicily). Morphology on SEM of male Dirofilaria repens.

The prevalence of canine filariasis was investigated in 4 municipalities of Trapani province (Campobello di Mazara, Castelvetrano, Marsala and Mazara del Vallo), an area where 8 human cases of dirofilariasis due to Dirofilaria (Nochtiella) repens have occurred during the last decade. Blood samples were collected late in the afternoon, during August and September 1995, and examined by Knott technique for the presence of microfilariae. Sixtythree (29.3%) out of 215 domestic dogs (98 males, 117 females; 40 sub-adults, 175 adults) proved to be positive for microfilariae: 55 (25.6%) for D. repens, 13 (6.0%) for Dipetalonema reconditum, 1 (0.5%) for D. immitis; 6 (2.8%) mixed infections (5 D. repens + D. reconditum and 1 D. repens + D. immitis) were also found. The surface topography via SEM of an adult male specimen of D. repens found in a dog during necroscopy is also described. The relatively large number of human cases of dirofilariasis appears to be related to the high prevalence of D. repens observed in dogs of Trapani province. This matter should be investigated more extensively in this area.

Animals↗
PubMed1997

Persistence of human myiasis by Oestrus ovis L. (Diptera: Oestridae) among shepherds of the Etnean area (Sicily) for over 150 years.

From a study carried out in 22 townships of the Etnean area, by interviewing 112 shepherds, it was confirmed that 90 of them (80.3%), once or more in their lives, had contracted myiasis by Oestrus ovis L., habitual agent of estriasis in sheep. The most frequent sites of involvement were the pharynx (77 times), often extending to the larynx, the conjunctiva (56), followed by the nose (32) and rarely the ear (1). Multiple simultaneous sites involvement was also frequent affecting 54.4% of the shepherds. The chief symptom was pain, sometimes accompanied by fever and malaise. The shepherds go rarely to see a doctor (only 7 out of 90), the greater part preferring traditional remedies. It is curious to note that myiasis associated with Oe. ovis was already observed more than 150 years ago by a Sicilian physician, G. A. Galvagni, who had pointed out the high incidence of the myiasis in shepherds in the area. The persistence of human myiasis in the Etnean area appears to be related to the fact that in this region the conditions of sheep farming and the lifestyle of shepherds have not changed so much since then.

Agricultural Workers' Diseases↗
PubMed1990

Organization of individual cortical axons projecting from area V1 (area 17) to V2 (area 18) in the macaque monkey.

The present study uses the anterograde tracer, Phaseolus vulgaris-leucoagglutinin (PHA-L), to investigate the detailed morphology of individual axons projecting from area V1 to prestriate area V2. Observations are derived from serial reconstructions of 45 axons. Axons are found to differ both in laminar distribution and in arbor size. The majority (25/45; 56%) terminate in the upper half of layer 4 and the lower part of layer 3. Terminal clusters typically measure about 200 microns in diameter (dimensions are uncorrected for shrinkage), and are either in one, two, or occasionally three patches. Patches are separated by 200-500 microns. Of these 25 axons, four also have minor collaterals to layer 5. Of the remaining 20 axons in our sample, eight have one or two terminal arbors (about 200 microns in diameter) mainly in layer 3; another eight have terminations, organized as a single field (about 350 microns in diameter), within layer 4; and four axons have much larger terminal fields (1.0-1.2 mm x 0.3 mm), in layers 3 and 4. These morphological differences might constitute a gradient or, alternately, indicate distinct subgroups within the striate efferent population. Large terminal fields are asymmetrical, with their long axis oriented in an anterior-posterior fashion toward the depth of the lunate sulcus. Axons with two terminal arbors have a similar bias. As this arrangement is approximately perpendicular to the border of V1, we suggest that striate axons may be extended preferentially along the length of the stripelike compartments in V2. These compartments are also arrayed perpendicular to the border between areas V1 and V2. Reconstruction of small groups of 2-4 convergent axons demonstrates that axons with different morphology (i.e. large or small terminal fields) can occur within the same projection focus. Terminal arbors belonging to different axons can overlap, but tend not to be superimposed exactly.

Animals↗
PubMed1989

Terminal arbors of individual "feedback" axons projecting from area V2 to V1 in the macaque monkey: a study using immunohistochemistry of anterogradely transported Phaseolus vulgaris-leucoagglutinin.

In the present study, the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) was injected into area V2 in order to demonstrate the precise morphology of individual axons from area V2 to V1. On the basis of 28 complete axon reconstructions, several characteristic features have been identified. 1) Individual axons arborize in multiple layers: 1, 2, 5, and (inconstantly) 3. A single axon may have numerous terminal clusters in layers 1 and 2, but at most one in layer 3. 2) Axons typically ascend to layer 1, turn asymmetrically in one direction, and travel for long distances in this layer (1.10-4.30 mm; dimensions uncorrected for shrinkage). A few axons (three of 28 reconstructed) were found to have a single terminal cluster (0.3-0.5 mm wide) in layers 1 and 2. 3) Collaterals in layer 5 seem to extend over shorter distances (0.60 mm or less). 4) Delicate sprays of boutons (both beads and spines) are clustered along the main trunk. Spacing is variable but usually ranges from 0.35 mm to 0.65 mm. 5) In addition to clustered boutons, there can be linear collaterals, continuously studded with boutons, parallel to the main axon in layer 1. These results indicate that axons from V2 have complex radial and tangential distributions in V1. Terminations in different layers may be directed to different sets of neurons or to different portions of the dendritic tree (for example, distal portions of pyramidal neuron apical dendrites in layers 1 and 2, but more proximal portions in layer 3). Clustered terminations over wide tangential areas may imply a divergent innervation by a single axon of multiple compartmental structures, such as ocular dominance columns or cytochrome oxidase patches.

Animals↗
PubMed1989

[Antibodies against Toxocara canis in human serum from western Sicily].

335 human sera of western Sicily were examined with an ELISA method for the prevalence of antibodies anti-Toxocara canis. The results (13% pos. in psychiatric patients,9.4% in farmers, 1.9% in children and 1.2% in blood donors) seem to indicate a strong correlation between style of life and infestation risk.

Adult↗