The innervation of head neuromast rows in eleotridine gobies (Teleostei: Gobioidei)

The innervation of free neuromast (sensory papillae) rows is described from Sihler wholemount preparations of four species of eleotridine gobies, one ( Perccottus glenii ) representing the 'longitudinal' type of neuromast arrangement, the others ( Butis buits, Bostrychus urophthalmus, B. marmoratus ) the 'transverse' arrangement. In the latter, the characteristic transverse cheek rows (1–7) are innervated from the infraorbital trunk of the anterior lateral-line nerve. Longitudinal cheek rows b and d , and the three opercular rows, ot, os and oi , common to all species, are innervated by rami of the hyomandibular trunk of the same nerve. Two neuromast groupings are shown to have a mixed nerve supply. For the median preorbital snout rows, there is innervation from the infraorbital ( s ³ and r ) as well as the supraorbital ( s ¹ and s ²) trunks of the anterior lateral line nerve. The anterior dorsal rows are supplied both by the posterior lateral-line supratemporal ramus (rows g and m ) and the anterior lateral-line supraorbital trunk (rows o and n ). The neuromast rows, under the designations of Sanzo, are tabulated according to innervation and their putative origin in the phyletic replacement of a complete head canal system seen in more generalized percomorph fishes.     

Hepatozoon in grey squirrels (Sciurus carolinensis) trapped near Reading, Berkshire

Hepatozoon infections of Sciurus carolinensis were investigated by a 30-month capture/recapture trapping programme. Details of trapping methods, squirrel husbandry and blood sampling techniques are discussed.
Hepatozoon gametocytes infected blood monocytes and could be detected in blood smears or by concentration of leucocytes. From blood smears, 71% (154/218) of the squirrels were infected. Prevalence appeared to be influenced by host hormonal and breeding patterns. Significantly more adult males than adult females were infected (P<0.025). Infections were significantly more prevalent in adults overall and in adult males than in juvenile males (P< 0.001 in both cases), but not significantly different between female adults and juveniles (P>0.05). Prevalence rates were generally higher: (i) in summer and winter, when animals mate, compared to spring and autumn; and (ii) in 1984 than in 1983, possibly relating to differences of squirrel breeding success and juvenile recruitment in the two years. Parasitaemias were overdispersed in the sampled host population and significantly lower in females (38%) than in males (48%) (P<0.05), although there was no significant difference between the age classes. Animals, either recaptured or laboratory-maintained, showed chronic fluctuating parasitaemias with no obvious pattern. Squirrels with overt parasitaemias showed trophozoites and schizogonic stages of Hepatozoon in the lung and rarely in liver and spleen. Three out of 16 animals with no obvious parasitaemias had lung tissue stages of the parasite. Results suggest that Hepatozoon is more prevalent in grey squirrel populations than blood smears suggest.     

A review of the bioavailability of petroleum constituents

Exposure to petroleum constituents at contaminated sites may occur through a variety of pathways, including inhalation of vapors and particulates, ingestion of water and soils, and dermal contact with water and soils. Accurately assessing the human health risks from such exposures requires information on the medium‐ and route‐specific bioavailability of petroleum constituents (e.g., how well these chemicals enter the body via the gastrointestinal tract and skin). For example, when the medium or exposure route in an animal toxicity assay (e.g., ingestion of water) differs from the actual route of human exposure at the petroleum contaminated site (e.g., dermal contact with soil), adjustments should be made that reflect the relative bioavailability of the chemical in the different media. The focus of this article is on (1) the availability of oral and dermal absorption data for one PAH (benzo[a]pyrene, (B[a]P) and three VOCs in soil (benzene, toluene, and xylene); (2) factors affecting the uptake of these PAHs and VOCs from soil; and (3) ways to incorporate bioavailability data into human health risk assessments. Based on our review, we recommend the following default values for the oral and dermal absorption of B[a]P, benzene, toluene, and xylene from soil:

A review of the bioavailability of petroleum constituents

All authors

Jennifer Bramard & Barbara D. Beck

https://doi.org/10.1080/15320389209383417

Published online:

02 December 2008

Display Table

Site‐specific information such as chemical concentrations in soil, soil characteristics, soil loadings on the skin, contact site, and contact time could result in modifications of these numbers. As shown, our default absorption values are generally less than those recommended by the U.S. EPA (1991a,b,c). The implications of these estimates of bioavailability for risk assessment and for the selection of soil cleanup levels at petroleum‐contaminated sites are discussed.     

Tracheal smooth muscle responses to substance P and neurokinin A in the piglet.

The tachykinins substance P (SP) and neurokinin A (NKA) have been shown to induce airway smooth muscle contraction in mature animals, and the enzyme neutral endopeptidase (NEP) modulates this effect. We evaluated maturation of SP- and NKA-induced tracheal smooth muscle contraction and modulation of their effects by NEP in anesthetized, paralyzed, and artificially ventilated piglets less than 4 days, 2-3 wk, and 10 wk of age. Tracheal smooth muscle tension was measured in vivo from an open tracheal segment by use of a force transducer. Intravenous SP caused a dose-dependent increase in tracheal tension in all three age groups; however, the response in less than 4-day-old piglets was significantly weaker than in 2- to 3- and 10-wk-old piglets. NKA caused a dose-dependent increase in tracheal tension only in 2- to 3- and 10-wk-old piglets. The response of tracheal tension to NKA was weaker than the response to SP in all age groups. Atropine (2 mg/kg) significantly diminished the responses of tracheal tension to SP and NKA, indicating a cholinergic contribution to these responses at all ages. Intravenous thiorphan, a known NEP inhibitor, potentiated the effects of SP only in 2- to 3- and 10-wk-old piglets and did not affect the response of tracheal tension to NKA at any age. Biochemical analyses demonstrated a significant increase in tracheal NEP activity in comparably aged piglets over the first 10 wk of life.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pertussis toxin and H-7 distinguish mechanisms involved in eicosanoid release from lipopolysaccharide-primed macrophages. Eicosanoid release from lipopolysaccharide-primed macrophages

Release of eicosanoids is an important response of macrophages to inflammation and bacterial infection. At low concentrations, bacterial lipopolysaccharide (1-2 micrograms/ml) fails to stimulate eicosanoid release in resident peritoneal macrophages but primes the macrophages for a greatly enhanced release of eicosanoids on stimulation with the calcium ionophore A23187 (0.1 microM) or with phorbol 12-myristate 13-acetate (50 nM), an activator of protein kinase C. Incubation of macrophages with Bordetella pertussis toxin, prior to priming with lipopolysaccharide, inhibited the release of both cyclooxygenase and lipoxygenase products upon A23187 stimulation. Pertussis toxin treatment of macrophages had no effect on eicosanoid release when the stimulus was phorbol 12-myristate 13-acetate. The presence of 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), an effective inhibitor of protein kinase C, during lipopolysaccharide priming and subsequent stimulation significantly inhibited eicosanoid release when phorbol 12-myristate 13-acetate was the stimulus, but did not affect eicosanoid release stimulated by A23187. Based on these results, at least two mechanisms, distinguished by apparent differences in sensitivity to pertussis-toxin-sensitive, guanine-nucleotide-binding proteins and protein kinase C, are involved in eicosanoid secretion by lipopolysaccharide-activated macrophages in response to A23187 and phorbol 12-myristate 13-acetate.     

Effect of canine surfactant protein (SP-A) on the respiratory burst of phagocytic cells

Cells obtained from bronchoalveolar lavage, or neutrophils of peripheral blood of dog, were incubated with the canine surfactant-associated protein A (SP-A). A significant decrease of the production of Superoxide anion was observed after subsequent stimulation with phorbol-12-myristate-13-acetate (PMA) as measured by the lucigenin-dependent chemiluminesence (CL). Several other proteins used for control experiments did not decrease lucigenin-dependent CL, indicating a specific effect of SP-A on phagocytes. Treatment of SP-A with collagenase prior to incubation with neutrophils destroyed the depleting effect on oxygen radical production of PMA-stimulated cells. We propose that SP-A acts as a regulatory factor of the respitatory burst of alveolar macrophages and neutrophils in the lungs. The inhibitory effect of SP-A is down-regulated by collagenase released from stimulated alveolar macrophages.     

A Simple Method for Estimating Average Number of Nucleotide Substitutions within and between Populations from Restriction Data

A simple method is proposed for estimating the average number of nucleotide substitutions per site within and between populations for the case where a large number of individuals are examined for many restriction enzymes. This method gives essentially the same results as those obtained by Nei and Li's method but saves a large amount of computer time. The variances of the quantities estimated can be obtained by the jackknife method, and these variances are very similar to those obtained by Nei and Jin's more sophisticated method. A similar method can also be applied to DNA sequence data.