scholarly journals The Pre-Natal Development of Wool Follicles in Merino Sheep

1956 ◽  
Vol 9 (3) ◽  
pp. 423 ◽  
Author(s):  
Margaret H Hardy ◽  
AG Lyne
Keyword(s):  
Histological Study ◽  
Serial Sections ◽  
Merino Sheep

A histological study has been mado of wool folliclos in skin from the trunk of 24 shcep foetuses ranging in age from (J)) to 145 days of gestation. Fifteen of t.hese foetuses are known to be entirely Merino in origin, and the remainder are believed to be wholly or predominantly Merino. Extensive use has berm mado of serial sections parallel to the axis of the wool follicles as well as those parallel to [,he skin snrfaco. Skin from ]\lorino lambs and adults has also boen examined.

scholarly journals The Pre-Natal Development of Skin and hair in Cattle (Bos Taurus L.)

1959 ◽  
Vol 12 (1) ◽  
pp. 72 ◽  
Author(s):  
AG Lyne ◽  
Margaret J Heideman
Keyword(s):  
Hair Follicle ◽  
Bos Taurus ◽  
Histological Study ◽  
Hair Follicles ◽  
Serial Sections ◽  
Lateral Region ◽  
New Born ◽  
Whole Mount ◽  
Skin Samples

A histological study has been made of the development of the skin and hair follicles in 33 foetuses, ranging in age from 68 to 274 days, and seven new-born specimens, of various breeds of Bos taurus L. Skin samples were taken from the mid-lateral region of the trunk, and both serial sections and whole mount preparations have been examined. Extensive use has been made of' counts of the follicle and hair population as well as skin and hair follicle measurements which hitherto have apparently received little attention in studies of this type.

Histological study of external budding in Taenia crassiceps

1970 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
FM Bilqees
Keyword(s):  
Life Cycle ◽  
Adult Worm ◽  
Histological Study ◽  
Laboratory Mouse ◽  
Serial Sections ◽  
Stages Of Development ◽  
Taenia Crassiceps ◽  
Whole Mounts ◽  
Usual Pattern

The life cycle of T, crassiceps, which grows to the adult worm in the intestine of dogs and other canids and to a cysticercus in the laboratory mouse and other rodents, deviates from the usual pattern for taeniids because the embryo not only grows but later reproduces asexually by exogenous budding either subcutaneously or in body cavities. Differentiation of the bud was followed by removing cestodes at various stages of development. Living specimens, whole mounts, and serial sections, fixed and stained by various methods, were used. The subtegumental cells appear to dominate the process of budding at the abscolex end of the metacestode. Usually the bud separates from the budder after the lacuna is formed. The study demonstrates the importance of the subtegumental cells in the growth and differentiation of buds.

scholarly journals Experimental Assessment of a New Type of Vascular Prostheses with Adiponectin (Adipograft Ra 1Vk 7/350) on Sheep

2014 ◽  
Vol 64 (4) ◽  
pp. 426-437
Author(s):  
Podlaha Jiří ◽  
Schwanhaeuser Kräuff
Keyword(s):  
Turning Point ◽  
Histological Study ◽  
Vascular Prosthesis ◽  
High Quality ◽  
Experimental Assessment ◽  
Vascular Prostheses ◽  
Prophylactic Measure ◽  
Merino Sheep ◽  
New Type ◽  
The Common

Abstract Despite medical advancements, the development of an ideal vascular prosthesis still poses a great challenge. In this study the researchers tried to test and verify the characteristics of a new type of vascular prosthesis, using adiponectin (Adipograft Ra 1vk 7/350) developed at the Knitting Research Institute, a.s. Brno. Two types of vascular prostheses (12 with adiponectin and 6 as a control without adiponectin) were implanted in nine healthy 4-year-old Merino sheep. The implantation site was the common carotid artery and the length of the implant was 10 cm. We applied the theory of the protected coagulum, whereby all sheep received antibiotics as a prophylactic measure. A Doppler U.S. was performed before finishing each operation, in order to verify the patency of the prostheses. Each animal was followed up during the whole study and the prostheses were extirpated on days 30 and 100 (1 and 3 months). It was observed that all prostheses coated with adiponectin showed patency after extirpation. The lumen implants were of a consistent thickness of 7 mm. Histological study of the implanted prostheses confirmed a quick, high quality, healing. Experimental vascular prostheses coated with adiponectin appeared to be successful in clinical practice. The researchers think that Adipograft Ra 1vk 7/350 can be a turning point in the development of vascular prostheses, due to its patency and quick healing.

A Histological Study of the Peripheral Receptors in the Thorax of Land Isopods, with Special Reference to the Location of Possible Hygroreceptors

1963 ◽  
Vol s3-104 (67) ◽  
pp. 337-350
Author(s):  
D. E. JANS ◽  
K. F. A. ROSS
Keyword(s):  
Special Reference ◽  
Histological Study ◽  
The Body ◽  
The Other ◽  
Serial Sections ◽  
Nerve Fibres ◽  
Porcellio Scaber ◽  
Different Types ◽  
Thoracic And Abdominal ◽  
Lateral Plates

By double embedding whole isopods in paraffin wax and celloidin, after fixing them in Bodian's fluid, it was possible to obtain complete sets of undamaged serial sections through the thoracic and abdominal regions of females of Oniscus asellus L. and Porcellio scaber Latr., and also some incomplete series through males of these species and a species of the genus Armadillidium. These sections were stained by the methods of Bodian and of Holmes to show the nerve-fibres. They were then carefully studied, and the distribution and the morphology of all peripheral nerveendings and receptors in the body were determined as completely as possible. In all, 6 different types of terminations were found; and in some cases it was possible to draw valid inferences about their probable function from a consideration of their location and their morphology alone. Three of them are probably tactile. The function of the other three is much more uncertain; but one of them, a group of pit-like terminations situated on the under side of the lateral plates on each side of the thoracic segments, is particularly suitably located to function as a receptor of temperature or humidity, and morphologically it bears some resemblance to certain proven hygroreceptors in other arthropods. This particular termination and one of the other types, consisting of ventrally situated partially retracted hairs, do not appear to have been described previously in the land isopods.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

Ultrastructural localization of neuropeptides in the rat brain

1978 ◽  
Vol 36 (2) ◽  
pp. 612-613
Author(s):  
F.W. Van Leeuwen
Keyword(s):  
Freeze Substitution ◽  
Ultrastructural Localization ◽  
Serial Sections ◽  
Microscopical Level ◽  
Electron Microscopical Level ◽  
Enzyme Method ◽  
Perfusion Fixation ◽  
Electron Microscopical ◽  
Unlabeled Antibody ◽  
Peroxidase Conjugate

In order to obtain specific and optimal ultrastructural localization of vasopressin and oxytocin in the hypothalamo-neurohypophyseal system of the rat, 2 staining procedures and several tissue treatments were evaluated using neurohypophyseal tissue. It appeared from these studies that post-embedding staining with the unlabeled antibody enzyme method developed by Sternberger allows greater dilution of the first antibody (anti-vasopressin, 1:4800) than the indirect procedure (1:320) using a peroxidase conjugate as second antibody. Immersion fixation with 4% formalin during 24 hours gave better results (general ultrastructure, immunoreactivity) than those obtained by perfusion fixation with 2.5% glutaraldehyde-1% paraformaldehyde or freeze substitution.Since no reliable specificity tests were performed at the electron microscopical level, tests were developed for antibodies against both vasopressin and oxytocin. For anti-vasopressin plasma neural lobes of homozygous Brattleboro rats, that are lacking vasopressin by a genet- ical defect, were used. For antibodies against both hormones serial sections were used that were alternately incubated with the antibodies.

Probing the ultrastructure of the mitotic and meiotic spindle in eggs: An expeditious approach based on semi-thin (0.25 μm) serial sections

1983 ◽  
Vol 41 ◽  
pp. 552-555
Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
Meiotic Spindle ◽  
Serial Sections ◽  
Mitotic Apparatus ◽  
Thin Sections ◽  
Cell Cycles ◽  
Ultrastructural Studies

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).

Computer Reconstruction of the Cellular Architecture of the Daphnia Magna Optic Ganglion

1975 ◽  
Vol 33 ◽  
pp. 284-285
Author(s):  
E. R. Macagno ◽  
C. Levinthal
Keyword(s):  
Daphnia Magna ◽  
Genetic Background ◽  
Compound Eye ◽  
Synaptic Connectivity ◽  
Serial Sections ◽  
Cross Sectional ◽  
Small Crustacean ◽  
Optic Ganglion ◽  
Structural Invariance ◽  
High Degree

The optic ganglion of Daphnia Magna, a small crustacean that reproduces parthenogenetically contains about three hundred neurons: 110 neurons in the Lamina or anterior region and about 190 neurons in the Medulla or posterior region. The ganglion lies in the midplane of the organism and shows a high degree of left-right symmetry in its structures. The Lamina neurons form the first projection of the visual output from 176 retinula cells in the compound eye. In order to answer questions about structural invariance under constant genetic background, we have begun to reconstruct in detail the morphology and synaptic connectivity of various neurons in this ganglion from electron micrographs of serial sections (1). The ganglion is sectioned in a dorso-ventra1 direction so as to minimize the cross-sectional area photographed in each section. This area is about 60 μm x 120 μm, and hence most of the ganglion fit in a single 70 mm micrograph at the lowest magnification (685x) available on our Zeiss EM9-S.

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