Vaccines to protect Hereford cattle against the cattle tick, Boophilus microplus.

Vaccines made from gut and gut and synganglion tissue dissected from Boophilus microplus gave 87% and 80% protection, respectively, compared with adjuvant-injected controls in cattle against three infestations with 20,000 larval ticks administered over 14 days. A vaccine prepared from synganglion alone did not protect cattle. Ticks collected from vaccinated cattle produced 95% and 91% fewer eggs, respectively, than ticks from control animals. Vaccinated cattle were protected (36%) 7 months after they had been immunized with tick antigens. Antibody responses to the vaccines were detected by enzyme-linked immunosorbent assay (ELISA).     

银盾革蜱神经分泌细胞的超微结构和分泌活性的研究

用透射电镜观察了银盾革蜱（Ｄｅｒｍａｃｅｎｔｏｒｎｉｖｅｕｓ）雌虫神经分泌细胞的超微结构。神经分泌细胞位于合神经节中，具有较小的核／质比。其细胞质中含有的高尔基体、粗糙内质网以及分泌颗粒是分泌活性的标志。正常雌虫饱食后２ｄ达到分泌活性的最高峰，随后即下降，到产卵时达到最低水平。滞育雌虫饱食后亦达到分泌的高峰，并可持续至少８５ｄ，此时细胞质中出现大量的平滑内质网。     

Access of autonomic nerves through the optic canal, and their orbital distribution in man

The notion that autonomic nerves from the internal carotid plexus are transmitted to the orbit with the ophthalmic artery through the optic canal has been variously assumed, disregarded, or denied, but never demonstrated. The objective of this study was to examine the contents of the canal, identify any autonomic nerves, and follow their passage within the orbit. The soft tissues of the optic canal, and the apical tissues of the orbit were removed and examined histologically using 10 cadaver preparations. Additionally, tissues from an orbital exenteration and 10 ocular enucleation or donor specimens were prepared. Some of the latter material was examined with an electron microscope. Numerous autonomic nerves (four to 25, ranging in diameter from 23 to 130 microm) entered the orbit from the internal carotid plexus in the periosteum of the optic canal, the optic nerve dura mater, or the adventitia of the ophthalmic artery. In the orbit they advanced in the loose connective tissue covering the optic nerve dura and joined ciliary nerves close to the eye or entered the eye directly. None were observed to penetrate the dura, apart from a nerve accompanying the central retinal artery. Others were distributed with the ophthalmic artery and its branches. It is concluded that the optic canal is a regular, and often major, route for autonomic nerve distribution to the eye and orbit.     

颈内动脉压迫视神经颅内段的组织学改变及其机制

目的:观察视神经受压后的组织学改变,探讨因压迫所致视野缺损发生的机制。方法:60-80岁的老年人脑,组织切片观察颈内动脉内膜钙化压迫视神经颅内段引起的神经组织学改变。结果:粥样硬化的颈内动脉可压迫视神经并在其表面形成明显压迹。神经受压后,中隔变窄,神经束呈条索状,束内营养小动脉硬化,管腔阻塞,节细胞轴突萎缩,重者可全部消失,少突胶质细胞增多,肿胀。结论:视神经纤维萎缩是由于阻塞了神经束内营养小动脉缺血所致,以乳头黄斑束受累为甚,是视野缺损发生的原因之一。     

Influence of feeding and starvation on the persistence and transmission of Quaranfil virus by Argas (Persicargas) arboreus (Acari: Argasidae)

Viral antigen was detected in the cytoplasm and in associated membranes of salivary gland acinus cells by indirect immunofluorescence and immunoperoxidase staining. Viral ribonucleoproteins (indicated histochemically by presence of pyroninophilic granules) which had accumulated in the cytoplasm of salivary gland type B (granular) acini of unfed Argas (Persicargas) arboreus Kaiser, Hoogstraal & Kohls were no longer visible 24 h after feeding. Virus in tick salivary glands increased from 300 to 500 plaque-forming units during the brief feeding interval (approximately 1 h), but virus was not detectable by 72 h. Overall salivary gland, ovarian, and synganglion tissue levels of Quaranfil virus decreased in the 96 h after feeding, except for synganglion samples in which virus titers increased during 24 h after feeding. Starvation for 105 d resulted in a sevenfold increase in salivary gland viral content compared with those starved 45 d, whereas synganglion tissue titers for Quaranfil virus became undetectable, and ovarian tissue values were similar to those starved for 45 d. Feeding had a greater effect on viral persistence in tissues for ticks starved 60 additional d (comparing 45 with 105 d) in that no Quaranfil virus was detected in any tissue after 48 h (compared with 72 h). Feeding infected ticks (with short extrinsic incubation) on chicks resulted in a peak of host mortality on days 7 and 8, whereas long extrinsic incubation resulted in sporadic mortality over 20 d of monitoring.     

Conditioning of aversion to alcohol orosensory cues in 5- and 10-day rats: subsequent reduction in alcohol ingestion

Two experiments examined in 5- and 10-day-old rat pups the impact of alcohol olfactory aversions upon subsequent alcohol intake. In Experiment 1 it was observed that at both ages, animals given a single pairing of alcohol odor and LiCl subsequently consumed less alcohol than those in any of 4 control conditions (alcohol odor unpaired with LiCl, alcohol odor exposure, lemon odor paired with LiCl, and untreated animals). In Experiment 2, pups of both age groups were given LiCl following exposure to alcohol odor, the infusion of an alcohol solution or both stimuli simultaneously. Rats given explicitly unpaired presentations of the different conditioned stimuli and internal malaise served as controls. It was observed that equivalent aversions to alcohol ingestion were expressed whether the infants had experienced the alcohol odor, the alcohol infusion, or both, paired with toxicosis. These experiments extend the ontogenetic spectrum of circumstances in which olfactory experiences affect subsequent ethanol ingestion and also may indicate an early nondifferentiated processing of odorant and gustatory cues arising from an ethanol stimulus.     

Effects of permethrin on the salivary glands and neuroendocrine organs of unfed female Hyalomma (Hyalomma) dromedarii (Ixodoidea: Ixodidae)

Permethrin-impregnated fabric has been shown to be an effective repellent against various tick species. However, some tick species are not repelled by this chemical. In Hyalomma dromedarii (Koch), permethrin exposure is reported to actually enhance the tick's attachment behavior. This study evaluated the histological effects of permethrin exposure on the salivary glands and neuroendocrine organs of unfed, virgin H. dromedarii ticks of uniform age. Three fabric treatments consisting of unwashed-untreated (control), washed after treatment (0.125 mg [AI] / cm2) and unwashed-treated were used after 5- and 10-min exposure times for unfed, unmated females. For all of the organs examined, the cellular structure of treated ticks differed from controls as evidenced by increases in cellular activity, as well as significant increases in the size of the cells of the organs under study (P < 0.05). These data conclusively demonstrate that an unexpected enhanced attachment response observed in this tick species after permethrin exposure is the direct result of increased neurosecretory and salivary gland activity induced by that exposure.     

Characteristic behavior of the respiratory muscles, esophagus, and external anal and urethral sphincters during straining, retching, and vomiting in the decerebrate dog

To ascertain differences in the brainstem pattern generators for straining and retching, discharges of 230 respiratory single motor units from the intercostal nerves and discharges of the nerves to accessory respiratory muscles, the esophagus, and external anal and urethral sphincters were observed during straining, retching, and vomiting (fictive expulsion) in decerebrate and paralyzed dogs. Straining and retching were identified with coactivation of the phrenic nerve and the nerve to the rectus abdominis, which was elicited by distension of the rectum and stomach, respectively. Synchronous discharges with each retch and straining were always exhibited by the phrenic nerve, the nerves innervating the abdominal part of the rectus abdominis and the external anal and urethral sphincters. In contrast, different behaviours were constantly observed in four nerves. 1) The nerves to the serratus dorsalis cranialis was inhibited during straining, but activated synchronously with each retch and vomiting. 2) Vagal pharyngeal branches innervating the upper esophagus and branches of the recurrent nerve innervating the lower part of the cervical esophagus fired synchronously with straining. The esophageal nerves, on the other hand, did not fire with each retch, but did fire strongly between retches. 3) The nerve to the sacrocaudalis dorsalis lateralis discharged concomitantly with straining but did not with retches. Straining and retching behaviors exhibited by the nerves innervating other thoracic accessory inspiratory muscles (the intercartilagineus, rectus thoracis, scalenus) varied from dog to dog. The nerves innervating the thoracic parts of the rectus abdominis and obliquus externus abdominis always discharged synchronously with straining, and discharged with retches in the majority of dogs, but did not in a minority of dogs. The expiratory units from the internal intercostal nerves showed intense discharges synchronously with coactivation in straining (96%), retching (65%), and vomiting (100%). In contrast, none of the inspiratory units from the external intercostal nerves exhibited such intense discharges with straining and retching. These results suggest that the functional difference in straining and retching mainly depends on the differences in the behavior of the serratus dorsalis cranialis and esophagus. The forms of this dependence were discussed.     

FMRFamide-like immunoreactivity in the brain of the honeybee (Apis mellifera). A light-and electron microscopical study

Peptide-FMRFamide-like immunoreactivity in the brain and suboesophageal ganglion of the honeybee Apis mellifera L. is demonstrated with the peroxidase-antiperoxidase technique. Immunoreactivity is found in about 120 perikarya of the brain and in about 30 of the suboesophageal ganglion. These cells are distributed in 13 paired clusters representing neurons of different types including neurosecretory neurons projecting to neurohemal organs. Immunoreactivity of different intensity is found in the non-glomerular neuropil around the mushroom bodies, in the lateral protocerebrum, the central body, the optic tubercles, the lobula and medulla of optic lobe, the ocellar neuropil, in multiglomerular elements of the antennal lobes and in the dorsal deuterocerebrum. In the mushroom bodies, immunoreactivity is located in layers of the lobes and stalks, corresponding to intrinsic fibre bundles of some Kenyon cell types. The somata of these intrinsic cells did not show FMRFamide-like immunoreactivity. Electron microscopy of immunostained somata and nerve fibres was performed employing a pre-embedding peroxidase-antiperoxidase technique. Fibres of optic lobes and the non-glomerular neuropil contain immunoreactive dense core vesicles (diameter 50-165 nm) accumulated in boutons besides small synaptic vesicles and synaptic membrane specializations. Immunoreactive layers of the mushroom body neuropil were analysed at the ultrastructural level. Axon profiles with dense-core vesicles of a small type (diameter 35-75 nm) show only faint immunoreactive products. Immunoreactivity of intrinsic mushroom body neurons does not appear to be specifically correlated with synaptic organelles. Our results indicate that FMRFamide or related peptides peptides may be neuroactive compounds in different classes of nerve cells in the bee brain.     

Regrowth of PNS axons through grafts of the optic nerve of the Browman-Wyse (BW) mutant rat

Summary We have examined the behaviourin vivo of regenerating PNS axons in the presence of grafts of optic nerve taken from the Browman-Wyse mutant rat. Browman-Wyse optic nerves are unusual because a 2–4 mm length of the proximal (retinal) end of the nerve lacks oligodendrocytes and CNS myelin and therefore retinal ganglion cell axons lying within the proximal segment are unmyelinated and ensheathed by processes of astrocyte cytoplasm. Schwann cells may also be present within some proximal segments. Distally, Browman-Wyse optic nerves are morphologically and immunohistochemically indistinguishable from control optic nerves.When we grafted intact Browman-Wyse optic nerves or triplets consisting of proximal, junctional and distal segments of Browman-Wyse optic nerve between the stumps of freshly transected sciatic nerves, we found that regenerating axons avoided all the grafts which did not contain Schwann cells, i.e., proximal segments which contained only astrocytes; regions of Schwann cell-bearing proximal segments which did not contain Schwann cells; junctional and distal segments (which contained astrocytes, oligodendrocytes and CNS myelin debris). However, axons did enter and grow through proximal segments which contained Schwann cells in addition to astrocytes. Schwann cells were seen within grafts even after mitomycin C pretreatment of sciatic proximal nerve stumps had delayed outgrowth of Schwann cells from the host nerves; we therefore conclude that the Schwann cells which became associated with regenerating axons within the grafts of Browman-Wyse optic nerve were derived from an endogenous population. Our findings indicate that astrocytes may be capable of supporting axonal regeneration in the presence of Schwann cells.     

Regeneration of axons in the optic nerve of the adult Browman-Wyse (BW) mutant rat

Summary We have studied the regeneration of axons in the optic nerves of the BW rat in which both oligodendrocytes and CNS myelin are absent from a variable length of the proximal (retinal) end of the nerve. In the optic nerves of some of these animals, Schwann cells are present. Axons failed to regenerate in the exclusively astrocytic environment of the unmyelinated segment of BW optic nerves but readily regrew in the presence of Schwann cells even across the junctional zone and into the myelin debris filled distal segment. In the latter animals, the essential condition for regeneration was that the lesion was sited in a region of the nerve in which Schwann cells were resident. Regenerating fibres appeared to be sequestered within Schwann cell tubes although fibres traversed the neuropil intervening between the ends of discontinuous bundles of Schwann cell tubes, in both the proximal unmyelinated and myelin debris laden distal segments of the BW optic nerve. Regenerating axons never grew beyond the distal point of termination of the tubes. These observations demonstrate that central myelin is not an absolute requirement for regenerative failure, and that important contributing factors might include inhibition of astrocytes and/or absence of trophic factors. Regeneration presumably occurs in the BW optic nerve because trophic molecules are provided by resident Schwann cells, even in the presence of central myelin, oligodendrocytes and astrocytes. All the above experimental BW animals also have Schwann cells in their retinae which myelinate retinal ganglion cell axons in the fibre layer. Control animals comprised normal Long Evans Hooded rats, BW rats in which both retina and optic nerve were normal, and BW rats with Schwann cells in the retina but with normal, i.e. CNS myelinated, optic nerves. Regeneration was not observed in any of the control groups, demonstrating that, although the presence of Schwann cells in the retina may enhance the survival of retinal ganglion cells after crush, concomitant regrowth of axons cut in the optic nerve does not take place.     

Ultrastructural observations on the nervous system and the sensory organs of the infective stage (L3) ofOnchocerca volvulus (Nematoda: Filarioidea)

A detailed morphological investigation of the sensory organs and the nervous system of the third juvenile stage ofOnchocerca volvulus was performed at the ultrastructural level. A complex system of different receptor cells is found at the anterior and posterior end of this developmental stage. The eight papillae are arranged in two concentric circles consisting of two types of morphologically different receptors. Accessory nerve processes end free in the tip of the head. The paired amphids contain nine dendritic processes and accessory axons are seen in the surrounding cells. The basic structure of the amphids and of the circumoesophageal nerve ring is similar to that of other filarial nematodes. Two presumably neurosecretory cells are associated with the nerve ring. The reticular cytoplasm of these cells merges with the rough-surfaced endoplasmic reticulum of the lateral hypodermal chord. The paired phasmids at the posterior end of the developmental stages consist of single modified cilia that are embedded in an electron-dense mass. The receptor cell has access to the outside by a channel ending with a cuticular pore.     

Distribution and pharmacokinetics of precocene-II in the tick Ornithodoros parkeri (Acari: Argasidae)

Injected [3H]precocene-II spread from the hemocoel of Ornithodoros parkeri (Cooley) ticks to gut, salivary glands, synganglion, ovary, and the remainder of the body (carcass). Analyses at 2, 24, and 48 h after injection of precocene revealed that radioactivity remained at low levels in the synganglia and ovaries of fed-mated and fed-virgin females. Radioactivity increased gradually during 48 h after injection in salivary glands of fed-mated and fed-virgin ticks. It also increased gradually in the gut of fed virgins but not in fed-mated females. The carcasses contained the majority of total radioactivity at 2, 24, and 48 h after injection. Most of the radioactivity was found in ether-soluble compounds and only minimal amounts in water-soluble metabolites. Analysis of tick excreta and washings indicate that female O. parkeri excrete injected precocene very slowly; only 6% of total radioactivity was recovered in these samples during the 48 h after injection. Thin-layer chromatographic analyses of ether extracts of salivary glands and carcasses from fed-mated ticks 24 h after injection showed that the majority of the injected [3H]precocene-II was present in unchanged form.     

Coxiella and Rickettsiella: comparison of ultrastructure with special reference to their envelope.

Ultrastructure of Rickettsiella phytoseiuli (R.p.) multiplying in female ticks Dermacentor reticulatus was compared with that of Coxiella burnetii (C.b.) in the same ticks and in mice. C.b. in ticks and mice were always represented by 2 main cell types: small dense round or rod-like cells (DC) and larger bacteria-like cells (BC). DC were surrounded with a characteristic five-layered 20 nm thick envelope. Under the envelope DC had a stack of parallel intracytoplasmic membranes with a periodicity 5-6 nm. R.p. in tick fat body and synganglion were also inside phagosomes and formed 6 sequentially developing cell forms: dense (elementary), intermediate, bacterial, giant, and crystal-forming in which small dark bodies (initial particles) condensed. Two of them--dense and bacterial--corresponded to DC and BC of C.b. The DC envelope structure of R.p. was strikingly similar to that of some C.b. DC in mouse. We confirmed the general morphologic similarities in the structure of C.b. and R.p. DC and that of C.b. BC and intermediate cells of R.p. The envelope structure of DC type was found in other gracilicute bacteria and is supposed to have no taxonomic value but to be a reflection of population heterogeneity.     

Hypothalamo-hypophysial neurosecretory and vascular system of the teleost Labeo rohita (Ham.)

The paired nucleus preopticus (NPO) lying on either side of the III ventricle gives rise to the left and right main neurosecretory tracts which proceed posteroventrally towards the pituitary and give rise to several finer axons which ramify the infundibular floor adjacent to the pituitary. The bulk of the neurosecretory tracts enter the pars intermedia and few finer ones are seen among the pars distalis. The ventromedian component of the nucleus lateralis tuberis (NLT) is aldehyde fuchsin (AF) positive whereas the anterolateral neurons are AF negative. The internal carotid artery gives rise to the hypophysial and ventral hypothalamic arteries. The ventral hypothalamic artery gives rise to the primary capillary plexus at the infundibular floor region adjacent to the pituitary stalk. Portal vessels formed from this plexus largely irrigate the adenohypophysis. The hypophysial artery enters the neurohypophysis and gives rise to typical teleostean type neuradenointerface vasculature. Morphological contact between the neurosecretory axons and primary capillary plexus at the floor of the infundibulum suggests the possibility of at least some active principles entering the blood vessels. Structurally L. rohita exhibited both tetrapodean and teleostean type of hypothalamo-hypophysial vasculature. Morphological evidences suggest a direct neuroglandular and an indirect neurovasculoglandular pathways of hypothalamic control of hypophysis in L. rohita.     

Myelin vacuolation, optic neuropathy and retinal degeneration after closantel overdosage in sheep and in a goat

Toxicity of closantel, a halogenated salicylanilide anthelmintic, is described in 11 sheep and a goat, humanely killed 4-70 days after accidental overdosage. Status spongiosis of the cerebrum and cerebellum was present, its severity decreasing with time after treatment. Ultrastructurally, vacuoles in the cerebral white matter were seen to be intramyelinic due to splitting of myelin lamellae at the intraperiod lines, indicating myelin oedema. In the optic nerves, Wallerian degeneration and eventual fibrosis and atrophy of the nerves followed myelin vacuolation. Lesions in the optic nerves were particularly advanced in the intracanalicular portion, indicating a compressive neuropathy within the optic canal. Acute retinal lesions consisted of papilloedema, necrosis of the outer retinal layers (especially the photoreceptor layer), and retinal separation in tapetal and non-tapetal areas. In more chronic cases, the outer nuclear layer was diffusely attenuated and generally reduced to a single row of cells.     

Abdominal aortal plexus in fur animals (order Carnivora)

Abdominal aortal plexus was studied in foxes, polar foxes, sables and minks using macro-microscopic method of V.P. Vorobjov. Nerve ganglia of the abdominal aortal plexus in all examined fur animals are located at the roots of the largest arterial vessels originating from abdominal aorta and they are represented by paired abdominal, unpaired cranial mesenterial (excluding minks), inconstant visceral and aorto-renal, plural intermesenterial, single or plural caudal mesenterial nerve ganglia.     

人食管壁内血管和神经的分布特点

目的探讨人食管壁内血管和神经的分布特点及两者之间的关系。方法幼年尸体标本14例和成人标本4例,共计18例,采用硅胶血管灌注和再改良Sihler神经染色法相结合来显示人食管壁内血管及神经。结果人食管壁内血管整体分布以胸下段及腹段较密集,而颈段和胸上段相对较稀疏,整体前壁内血管较后壁内稀疏,壁内血管的细小分支间形成广泛的网状吻合。人食管壁内神经整体分布以腹段分布最稀疏,胸段壁内神经分布最多密集,但颈胸段壁内神经均衡分布,颈段上部可与来自于咽丛的神经分支形成吻合,食管壁内神经形成网状环路吻合。食管壁内血管与神经之间无明显的伴行关系。结论人食管壁内血管和神经分布均呈现网状吻合,但两者之间无明显伴行关系。