The capitulum and feeding mechanism of Ixodes hexagonus Leach

Parasitology ◽  
1951 ◽  
Vol 41 (1-2) ◽  
pp. 66-81 ◽  
Author(s):  
D. R. Arthur
Keyword(s):  
Lower Surface ◽  
Tissue Reaction ◽  
Lower Wall ◽  
Feeding Mechanism ◽  
External Structure ◽  
Basal Lobe ◽  
Ixodes Hexagonus ◽  
Pharyngeal Muscles ◽  
Pharyngeal Teeth

1. The external structure of the capitulum of Ixodes hexagonus is described in detail, and the differences between it and the closely allied I. cookei are noted.2. The capitulum is divisible into two portions, an extra-basis and basis regions. The former is divided into the hypostomal groove, the labrohypostomal groove and the labro-hypostomal gutter. Internally the basis is divided into dorsal and ventral chambers by the subcheliceral plate. The dorsal chamber houses the chelicerae while the pharynx and the salivary ducts occupy the ventral portion.3. The so-called ‘stylet-like process’ is the anterior prolongation from the basal lobe of the labrum, and forms the mid-rib of a lamella which divides the hypostome into a dorsal salivary channel and a ventral food conduit.4. There are rows of teeth on the internal faces of the anterior fifth of the pharynx. Two series of pharyngeal muscles are present: (i) those having a dorsal attachment to the floor of the salivary chamber, and (ii) those having similar attachments to the subcheliceral plates.5. During feeding the first incision is made by the denticulate apices of the digits and into it the hypostome is then forced. Further cutting by the digits enables the hypostome to penetrate to its base. At the same time the palps splay out. The blood is then drawn up the food conduit by the action of the sucking pharynx. The lower surface of the labrum is produced into a tooth-like projection that fits into a groove of the lower wall of the pharynx. Presumably it functions as a valve to prevent regurgitation of blood. The pharyngeal teeth may function as a supplementary valvular apparatus or else serve for the breakdown of erythrocytes.6. The tissue reaction of a stoat's skin to penetration by the capitulum of I. hexagonus is described.

The capitulum and feeding mechanism of Ixodes hexagonus Leach. II

Parasitology ◽  
1953 ◽  
Vol 42 (3-4) ◽  
pp. 187-191 ◽  
Author(s):  
D. R. Arthur
Keyword(s):  
Lower Surface ◽  
Homogeneous Material ◽  
Artificial Membranes ◽  
Feeding Mechanism ◽  
Ixodes Hexagonus ◽  
Dermal Cells

1. The action of the mouthparts of Ixodes hexagonus during the penetration of artificial membranes is described.2. Above the hypostomal groove, the chelicerae are closely apposed in the mid-line, but on the inner lower surface each inner cheliceral sheath is drawn into a ventral, toothed lobe, which overlies the hypostomal groove. This lobe disappears in front of the labro-hypostomal groove.3. A lamellate mass of homogeneous material surrounds the rostrum in the skin and at the tip of the hypostome there is marked cytolysis of the dermal cells. There are some pyknotic nuclei visible in this region, and the endothelial walls of the capillaries are swollen, and some contain many polymorphs.

The capitulum and feeding mechanism of Dermacentor parumapertus Neumann 1901

Parasitology ◽  
1957 ◽  
Vol 47 (1-2) ◽  
pp. 169-184 ◽  
Author(s):  
Don R. Arthur
Keyword(s):  
Salivary Glands ◽  
Vertical Wall ◽  
Feeding Mechanism ◽  
External Structure

The external structure of the capitulum of all stages of Dermacentor parumapertus is described in detail. The capitulum is divisible into an extra-basis and basis regions. The former consists of a dorsally grooved hypostome or food channel overlapped by a labral membrane, along its whole length. The salivary channel lies above the labral membrane, being bordered laterally by the meso-ventral margins of the outer cheliceral sheaths. Within the basis a vertical wall separates the base of the palpal cavity from the rest of the basis. This wall is produced backwards to form a wing or ala on either side of the pharynx and to it are attached dilator and constrictor muscles. Opening of the fore-part of the pharynx, i.e. where it is in the form of a V-shaped depression overlapped by a wedge, is effected by ventral and ventro-lateral dilator muscles, and closure by the elasticity of the pharyngeal walls.The pharynx, oesophagus and salivary glands are described.

Scanning Electron Microscopy of Dried and Acid Treated Shells of Difflugia

1973 ◽  
Vol 31 ◽  
pp. 448-449
Author(s):  
Barry S. Eckert ◽  
S. M. McGee-Russell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Critical Point ◽  
Point Method ◽  
External Structure ◽  
Cell Locomotion ◽  
Single Opening ◽  
Scanning Electron

Difflugia lobostoma is a shelled amoeba. The shell is an external structure of considerable mass which presents the animal with special restrictions in cell locomotion which are met by the development of active pseudopodial lobopodia containing, apparently, an organized system of thick and thin microfilaments (Eckert and McGee-Russell, 1972). The shell is constructed of sand grains picked up from the environment, and cemented into place with a secretion. There is a single opening through which lobopods extend. The organization of the shell was studied by scanning electron microscopy (SEM).Intact shells or animals with shells were dried by the critical point method of Anderson (1966) or air dried, after primary fixation in glutaraldehyde.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

Evaluation of gamma thalamotomy for parkinsonian and other tremors: survival of neurons adjacent to the thalamic lesion after gamma thalamotomy

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 120-127 ◽  
Author(s):  
Chihiro Ohye ◽  
Tohru Shibazaki ◽  
Junji Ishihara ◽  
Jie Zhang
Keyword(s):  
Tissue Reaction ◽  
Vascular Lesions ◽  
Thalamic Lesion ◽  
Mr Images ◽  
Unsatisfactory Result ◽  
Content Type ◽  
Rhythmic Discharge ◽  
Latent Interval ◽  
Fine Print

Object. The effects of gamma thalamotomy for parkinsonian and other kinds of tremor were evaluated. Methods. Thirty-six thalamotomies were performed in 31 patients by using a 4-mm collimator. The maximum dose was 150 Gy in the initial six cases, which was reduced to 130 Gy thereafter. The longest follow-up period was 6 years. The target was determined on T2-weighted and proton magnetic resonance (MR) images. The point chosen was in the lateral-most part of the thalamic ventralis intermedius nucleus. This is in keeping with open thalamotomy as practiced at the authors' institution. In 15 cases, gamma thalamotomy was the first surgical procedure. In other cases, previous therapeutic or vascular lesions were visible to facilitate targeting. Two types of tissue reaction were onserved on MR imaging: a simple oval shape and a complex irregular shape. Neither of these changes affected the clinical course. In the majority of cases, the tremor subsided after a latent interval of approximately 1 year after irradiation. The earliest response was demonstrated at 3 months. In five cases the tremor remained. In four of these cases, a second radiation session was administered. One of these four patients as well as another patient with an unsatisfactory result underwent open thalamotomy with microrecording. In both cases, depth recording adjacent to the necrotic area revealed normal neuronal activity, including the rhythmic discharge of tremor. Minor coagulation was performed and resulted in immediate and complete arrest of the remaining tremor. Conclusions. Gamma thalamotomy for Parkinson's disease seems to be an alternative useful method in selected cases.

Relationship Between Mineral Fiber-Induced Pulmonary Tissue Reaction and MIP-2

1997 ◽  
Vol 9 (4) ◽  
pp. 650
Author(s):  
Kyoung Ah Kim ◽  
Young Lim ◽  
Dong Won Lee ◽  
Heung Nam Kim ◽  
Hwang Sin Chang ◽  
...  
Keyword(s):  
Tissue Reaction ◽  
Pulmonary Tissue ◽  
Mineral Fiber
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