bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergency vaccination of rabies under limited resources – combating or containing?
Authors: Eisinger Dirk , Thulke Hans-Hermann , Selhorst Thomas , Müller Thomas
Published: March 2005

Background

Rabies is the most important viral zoonosis from a global perspective. Worldwide efforts to combat the disease by oral vaccination of reservoirs have managed to eradicate wildlife rabies in large areas of central Europe and North-America. Thus, repeated vaccination has been discontinued recently on a geographical scale. However, as rabies has not yet been eradicated globally, a serious risk of re-introduction remains. What is the best spatial design for an emergency vaccination program – particularly if resources are limited? Either, we treat a circular area around the detected case and run the risk of infected hosts leaving the limited control area, because a sufficient immunisation level has not yet been built up. Or, initially concentrate the SAME resources in order to establish a protective ring which is more distant from the infected local area, and which then holds out against the challenge of the approaching epidemic.

Methods

We developed a simulation model to contrast the two strategies for emergency vaccination. The spatial-explicit model is based on fox group home-ranges, which facilitates the simulation of rabies spread to larger areas relevant to management. We used individual-based fox groups to follow up the effects of vaccination in a detailed manner. Thus, regionally – bait distribution orientates itself to standard schemes of oral immunisation programs and locally – baits are assigned to individual foxes.

Results

Surprisingly, putting the controlled area ring-like around the outbreak does not outperform the circular area of the same size centred on the outbreak. Only during the very first baitings, does the ring area result in fewer breakouts. But then as rabies is eliminated within the circle area, the respective ring area fails, due to the non-controlled inner part.

We attempt to take advantage of the initially fewer breakouts beyond the ring when applying a mixed strategy. Therefore, after a certain number of baitings, the area under control was increased for both strategies towards the same larger circular area. The circle-circle strategy still outperforms the ring-circle strategy and analysis of the spatial-temporal disease spread reveals why: improving control efficacy by means of a mixed strategy is impossible in the field, due to the build-up time of population immunity.

Conclusion

For practical emergency management of a new outbreak of rabies, the ring-like application of oral vaccination is not a favourable strategy at all. Even if initial resources are substantially low and there is a serious risk of rabies cases outside the limited control area, our results suggest circular application instead of ring vaccination.
Postage stamp multiple anterior capsulorhexisotomies in pediatric cataract surgery
Authors: Titiyal Jeewan S , Sinha Rajesh , Sharma Namrata , Vajpayee Rasik B
Published: March 2005

Background

Capsule related complications are common following pediatric cataract surgery. We report a new technique of multiple anterior capsulorhexisotomies after lens aspiration and intraocular lens (IOL) implantation.

Methods

After performing automated lens aspiration, an IOL was implanted into the capsular bag. A bent 26 gauge needle was introduced through one side port and multiple small cuts were made in one half of the circumference of the anterior capsular rim by making a radial movement of the needle tip centripetally over the margin of the anterior capsular rim. The needle was again introduced through the other side port and multiple similar cuts were made in the other half thereby creating nearly 20 – 30 cuts at the margin of the anterior capsular rim.

Results

The mean size of the primary capsulorhexis was 4.33 ± 0.20 mm. A uniform enlargement of the capsulorhexis could be performed in all the eyes without peripheral extension in any of the eyes. There was no damage to the posterior capsule and no scratch mark on the IOL. In one eye, the primary capsulorhexis was slightly eccentric, though it was covering the IOL optic all around. The rhexisotomies in this eye were limited to the capsular rim that was overlapping more on the IOL optic (sectoral anterior capsulorhexisotomies).

Conclusion

The technique of postage stamp anterior capsulorhexisotomies is a feasible technique in pediatric cataracts.
Patterns of lung cancer mortality in 23 countries: Application of the Age-Period-Cohort model
Authors: Liaw Yung-Po , Huang Yi-Chia , Lien Guang-Wen
Published: March 2005

Background

Smoking habits do not seem to be the main explanation of the epidemiological characteristics of female lung cancer mortality in Asian countries. However, Asian countries are often excluded from studies of geographical differences in trends for lung cancer mortality. We thus examined lung cancer trends from 1971 to 1995 among men and women for 23 countries, including four in Asia.

Methods

International and national data were used to analyze lung cancer mortality from 1971 to 1995 in both sexes. Age-standardized mortality rates (ASMR) were analyzed in five consecutive five-year periods and for each five-year age group in the age range 30 to 79. The age-period-cohort (APC) model was used to estimate the period effect (adjusted for age and cohort effects) for mortality from lung cancer.

Results

The sex ratio of the ASMR for lung cancer was lower in Asian countries, while the sex ratio of smoking prevalence was higher in Asian countries. The mean values of the sex ratio of the ASMR from lung cancer in Taiwan, Hong Kong, Singapore, and Japan for the five 5-year period were 2.10, 2.39, 3.07, and 3.55, respectively. These values not only remained quite constant over each five-year period, but were also lower than seen in the western countries. The period effect, for lung cancer mortality as derived for the 23 countries from the APC model, could be classified into seven patterns.

Conclusion

Period effects for both men and women in 23 countries, as derived using the APC model, could be classified into seven patterns. Four Asian countries have a relatively low sex ratio in lung cancer mortality and a relatively high sex ratio in smoking prevalence. Factors other than smoking might be important, especially for women in Asian countries.
Cross-cultural adaptation of the VISA-A questionnaire, an index of clinical severity for patients with Achilles tendinopathy, with reliability, validity and structure evaluations
Authors: Silbernagel Karin Grävare , Thomeé Roland , Karlsson Jon
Published: March 2005

Background

Achilles tendinopathy is considered to be one of the most common overuse injuries in elite and recreational athletes and the recommended treatment varies. One factor that has been stressed in the literature is the lack of standardized outcome measures that can be used in all countries. One such standardized outcome measure is the Victorian Institute of Sports Assessment – Achilles (VISA-A) questionnaire, which is designed to evaluate the clinical severity for patients with Achilles tendinopathy. The purpose of this study was to cross-culturally adapt the VISA-A questionnaire to Swedish, and to perform reliability, validity and structure evaluations.

Methods

Cross-cultural adaptation was performed in several steps including translations, synthesis of translations, back translations, expert committee review and pre-testing. The final Swedish version, the VISA-A Swedish version (VISA-A-S) was tested for reliability on healthy individuals (n = 15), and patients (n = 22). Tests for internal consistency, validity and structure were performed on 51 patients.

Results

The VISA-A-S had good reliability for patients (r = 0.89, ICC = 0.89) and healthy individuals (r = 0.89–0.99, ICC = 0.88–0.99). The internal consistency was 0.77 (Cronbach's alpha). The mean [95% confidence interval] VISA-A-S score in the 51 patients (50 [44–56]) was significantly lower than in the healthy individuals (96 [94–99]). The VISA-A-S score correlated significantly (Spearman's r = -0.68) with another tendon grading system. Criterion validity was considered good when comparing the scores of the Swedish version with the English version in both healthy individuals and patients. The factor analysis gave the factors pain/symptoms and physical activity

Conclusion

The VISA-A-S questionnaire is a reliable and valid instrument and comparable to the original version. It measures two factors: pain/symptoms and physical activity, and can be used in both research and the clinical setting.
Increasing Incidence of Late Second Malignancies After Conditioning With Cyclophosphamide and Total-Body Irradiation and Autologous Bone Marrow Transplantation for Non-Hodgkin’s Lymphoma
Authors: Brown Jennifer R. , Yeckes Heather , Friedberg Jonathan W. , Neuberg Donna , Kim Helen , Nadler Lee M. , Freedman Arnold S.
Published: March 2005

Purpose

Although the risk of myelodysplastic syndrome (MDS) has been well-described following autologous bone marrow transplantation (ABMT), the risk of solid tumors has been poorly characterized. We report the incidence and outcome of solid tumors at 10-year follow-up in a large cohort of uniformly treated patients who underwent ABMT for non-Hodgkin’s lymphoma (NHL).

Patients and Methods

Between 1982 and 1997, 605 patients underwent ABMT for B-cell NHL, with uniform conditioning with cyclophosphamide and total-body irradiation followed by reinfusion of autologous bone marrow purged with anti–B-cell monoclonal antibodies. Current information on relapse of disease and second malignancies was obtained via an institutional review board–approved questionnaire sent to the referring oncologists.

Results

Forty-two solid tumors, six non-MDS hematologic malignancies, 39 nonmelanoma skin cancers, and 68 cases of MDS/acute myelogenous leukemia (AML) were observed at a median follow-up of 9.5 years. A cumulative incidence model using death as a competing risk found that the 10-year incidence of second malignancy is 21%, with 10.0% non-MDS malignancies. The projected incidence of all malignancies at 15 years is 29%. The principal risk factor for second malignancy is increased age at ABMT (P = .0002). In the entire cohort, 9.6% of patients have died of second malignancy.

Conclusion

Lengthy follow-up demonstrates a significant incidence of second malignancies after ABMT for NHL. Although the incidence of MDS/AML starts to plateau, the incidence of solid tumors continues to rise. Second malignancies are responsible for a significant fraction of overall mortality following ABMT.
Baroreflex mediated control of heart rate and vascular capacitance in trout
Authors: Sandblom E. , Axelsson M.
Published: March 2005

The baroreflex was triggered by altering branchial blood pressure with pre-and post-branchial occlusions for 30 s in rainbow trout Oncorhynchus mykiss. The cardiac limb of the baroreflex was monitored by continuous heart rate (fH) measurements. Responses of venous capacitance vessels were assessed, immediately following either occlusion, by measuring mean circulatory filling pressure (MCFP). Arterial responses were evaluated as the change in dorsal aortic blood pressure(Pda) before and after pre-branchial occlusion. In untreated fish pre-branchial occlusion resulted in tachycardia(62.4±2.4 to 69.1±1.7 beats min–1), decreased venous capacitance reflected as an increase in MCFP (0.17±0.03 to 0.27±0.03 kPa) and increased Pda (4.0±0.2 kPa compared to 3.2±0.1 kPa before occlusion). Post-branchial occlusion somewhat reversed the responses since fH decreased(62.4±2.4 to 53.0±3.1 beats min–1), whereas MCFP remained unaltered. Treatment with the α-adrenergic blocker prazosin (1 mg kg–1) increased resting MCFP to 0.33±0.03 kPa and appeared to abolish both venous and arterial responses to branchial occlusion. Subsequent atropine treatment (1.2 mg kg–1) abolished all chronotropic responses. We present for the first time ample evidence for baroreflex-mediated control of cardiovascular homeostasis, including both the chronotropic and the vascular limb of the baroreflex in an unanaesthetized fish. Furthermore, a novel technique to cannulate and occlude the dorsal aorta, using a Fogarty thru-lumen embolectomy catheter, is explained.
Complete dysraphism in 14 somite human embryo. A contribution to normal and abnormal morphogenesis
Authors: Dekaban A. S. , Bartelmez G. W.
Published: February 2005

The youngest completely dysraphic human embryo of 2.75 mm G.L. has been reconstructed from the microscopic sections and studied in detail. Although the neural folds failed to close throughout the dorsal extent of this 14 somite embryo, the beginning of independent closure took place rostrally at the torus opticus. The last feature has been shown to be the usual event in normal embryos of this stage. Careful examination of other structures than the nervous system reveals only minor abnormalities. Thus, the dispersion of cells of somites I and II as well as loosening of other sclerotomes in this region has begun prematurely. On the other hand, some retardation in the development of the pharynx, heart and nephros has been noted. Specifically, the chorda, the mesenchyme, blood vessels and gut have been found to be normal.

The literature pertaining to the closure of the neural folds has been discussed. Also, the reports on experimental inhibition of the formation of the neural tube are discussed with special emphasis on the work of Davis ('42).

Davis, J. O. 1942 Photochemical spectral analysis of neural tube formation. University of Missouri, Doctor' thesis.

The available evidence refutes the contention that the closure of neural folds is induced by adjacent structures of whatever derivation. It appears plausible as Davis demonstrated in his experiments that certain biochemical reactions within the neural epithelium may be involved in the process of normal closure of the neural folds.

Morphological findings in the present embryo do not support most of the previously advanced theories relating to the pathogenesis of dysraphic states.
The anatomy of the arterial supply to the cranial regions of the sheep and ox
Authors: Baldwin B. A.
Published: February 2005

By means of neoprene latex injected preparations, the anatomy of the arterial supply to the brain has been determined in the sheep and ox. In these two ruminant species, blood destined for the Circle of Willis and thence the brain must first pass through a well‐developed intra‐cranial carotid rete. The main source of blood supply to the carotid rete in the sheep is from the external carotid artery, via branches of the internal maxillary artery.

In both the sheep and the ox, the internal carotid artery is poorly developed in the young animal and the portion proximal to the carotid rete is absent in the adult. The internal carotid artery, in animals of all ages, can be traced through the rete to emerge as the efferent vessel, which divides to form the Circle of Willis.

In the ox, the main source of blood supply to the intra‐cranial carotid rete is the external carotid artery, via branches of the internal maxillary, but, in addition, the rete communicates directly with the vertebral arteries by way of the basi‐occipital arterial plexus.

Unlike most other species, the basilar artery in both sheep and ox has only tenuous connections with the vertebrals. In both species, the basilar artery tapers caudally and is continued as the ventral spinal artery. The basilar can therefore be regarded as a caudally directed branch of the Circle of Willis in both these animals. A well‐developed occipito‐vertebral anastomosis is a marked feature of the cephalic circulation in both sheep and ox.
Articular remodeling in the adult human temporomandibular joint
Authors: Moffett Benjamin C. , Johnson Lent C. , McCabe James B. , Askew Harold C.
Published: February 2005

Articular cartilage can proliferate sufficiently to alter the contours of joints, allowing them to adapt morphologically to various mechanical stresses. This remodeling has been classified into three types based on histologic criteria which were then applied to the temporomandibular joint. This joint has a fibrous type of articular tissue which is converted postnatally into fibrocartilage in the loaded areas. The thickness and cell population of this tissue, and the amount of internal reconstruction in the subchondral bone vary from one part of the joint to another. These changes appear related to the distribution of mechanical stresses in the joint. Conclusions drawn are: The temporomandibular joint shows the following remodeling trends: progressive remodeling on the anterior part of the condyle, medial part of the tubercle, and roof of the mandibular fossa; regressive remodeling on the posterior part of the condyle and on the lateral part of the tubercle. A perforation in the disc causes progressive remodeling on the condyle and regressive remodeling on the tubercle at the perforation site. Articular remodeling merges gradually into osteoarthritis as the articular tissue breaks down. The net effect of remodeling that has become uncompensated or pathologic is: condyle flattened and enlarged, tubercle resorbed, disc perforated, and articular surfaces uneven. If the dentition is not restored or replaced, a high rate of temporomandibular remodeling occurs which will probably continue into osteoarthritis.
Ultrastructure of bovine spermatozoa. I. The head of normal, ejaculated sperm
Authors: Saacke R. G. , Almquist J. O.
Published: February 2005

The ultrastructure of the normal bovine sperm head has been studied and particular attention has been given to the morphology and coverings of the nucleus and the formation of the equatorial segment.

The bovine sperm head consists of a homogeneous, flattened nucleus which is covered anteriorly by a three‐layered head cap and posteriorly by a loose, thin, dense, post‐nuclear cap. The nucleus measures approximately 0.2 to 0.3 μ in thickness. It tapers anteriorly to a sharp point along the frontal portion of the head and thickens posteriorly to accommodate an implantation socket for the tail. The nuclear membrane is double and porous. Vacuoles or openings of variable size and shape are present in the nucleoplasm, predominantly in the posterior portion of the nucleus. The head cap measures approximately 350 to 500 Å in thickness. It consists of dense inner and outer membranes which envelop a moderately electron dense middle layer. The head cap thickens across the frontal part of the head forming a ridge on one side of the nucleus.

A sequence of structural alterations in the head cap provide evidence for the appearance of the equatorial segment. The anterior portion of the head cap swells and deteriorates leaving the posterior portion intact as a band about the center of the nucleus. This band represents the equatorial segment.
Persistent stunting following x‐irradiation of the fetus
Authors: Rugh Roberts , Duhamel Lyse , Osborne Alan W. , Varma A.
Published: February 2005

CFl female mice were time mated and the embryos at each gestation day from 0.0 to 18.0 were x‐rayed to 100 r and the young carried to four months at which time a skeletal study was made. With this exposure the litters were reduced in size, following irradiation at certain gestation ages, and there was neo‐natal mortality so that this skeletal study is based upon the survivors to four months and represents the maximum development under the conditions of irradiation. The sex ratio was not altered by this irradiation. Male mice of this strain are always heavier than the females of the same age, and this exposure reduced the over‐all average of either sex by 2.5 grams. The skeletal measurements were taken from 1,005 radiographs of the living animals, and the averages calculated for each gestation day. There were sex differences in stunting, even when x‐irradiation occurred before day 9.0. When the differences were pronounced the female was the more adversely affected. The highest statistical significance in skeletal effects of seven measurements was between 11 and 13 days, when the embryo shows the earliest skeletal differentiation. Such mice were topographically well developed.
Studies on the nerve endings in the heart
Authors: Miller Malcolm R. , Kasahara Michiko
Published: February 2005

The hearts of dogs, cats, monkeys and lambs were studied by methylene blue perfusion and/or immersion. The principle types of sensory nerve terminals found in these hearts were end‐nets and complex unencapsulated endings. End‐nets are formed by the anastomoses of the branched dendrites of several apparently different myelinated fibers. Complex unencapsulated endings are discrete much branched endings of medium to large sized fibers and vary greatly in form and size.

The epicardium is supplied mainly with complex unencapsulated endings of highly variable form. End‐nets are rare in this location.

No sensory endings were demonstrated in the myocardium. Motor terminals in the form of fine unmyelinated nerve fibers were demonstrated on both atrial and ventricular myocardial muscle fibers.

The atrial endocardium, particularly in the areas of the openings of the great vessels and on the interatrial septum is the best innervated area of the heart. Endnets, and a wide variety of complex unencapsulated nerve endings occur singly and in combination in these areas.

The ventricular endocardium is supplied only with end‐nets.

The tricuspid and mitral valve leaflets have both end‐nets and complex unencapsulated endings while the aortic and pulmonary valve leaflets have only end‐nets.

The cardiac complex unencapsulated nerve endings (baroreceptors) are morphologically and functionally homologous to complex unencapsulated nerve endings (“stretch” receptors) in other areas of the organism.

The detailed structure and function of the end‐net terminals remain undetermined.
Structural and functional aspects of rodent salivary glands including two desert species
Authors: Shackleford John M. , Schneyer Charlotte A.
Published: February 2005

The submaxillary glands of the adult desert rat, antelope squirrel, rat, mouse and hamster have in common low levels of amylolytic enzyme in comparison with the relatively high levels of parotid gland amylase in these rodents. Submaxillary gland acini are classed as seromucous secreting although there is some variation in the carbohydrate histochemistry of these secreting units. Granular tubules are absent in antelope squirrel submaxillary glands and they are present in the submaxillary glands of the desert rat, rat, mouse and hamster. Electron micrographs reveal the presence of numerous basal folds in the acini of antelope squirrel submaxillary and parotid glands. These structures were not observed in the salivary gland acini of the hamster. Golgi membranes and “immature” secretion granules are topographically intimate in parotid glands of the hamster and antelope squirrel. In the submaxillary glands of these two rodents, the secretory material appears to originate in relation to the endoplasmic reticulum and secondarily, the granules become associated with a diffusely arranged system of Golgi membranes. The sublingual glands of all the rodents of this study are predominantly ones that produce mucous secretion and contain well developed striated duct systems. Of the salivary glands investigated in this study, the parotid glands of the rat, mouse and desert rat produce an isotonic saliva; the saliva of the other glands is definitely hypotonic.
Morphological and histochemical observations on trophoblast and decidua of the basal plate of the human placenta at term
Authors: Dallenbach‐Hellweg G. , Nette G.
Published: February 2005

The trophoblastic cells of the basal plate at the end of pregnancy still have an important hormonal function, in contrast to the decidual cells which appear to exert their main function at the onset of pregnancy. Possibly the decidual cells are functionally replaced by the basal trophoblastic cells, which phagocytize and destroy them. Although both types of cells are structurally quite similar and appear to produce the same hormones, but at different times, genetically they are very different. They degenerate morphologically in much the same way, but the cause for the retrogressive change for each is distinct. The trophoblastic cells degenerate with reticulum‐fibrinoid inclusions which they have mainly phagocytized. The decidual cells perish with collagen inclusions formed from collagen fibers they in turn produced.
Placentation in the spotted hyena (Crocuta crocuta Erxleben), with particular reference to the circulation
Authors: Wynn Ralph M. , Amoroso E. C.
Published: February 2005

A study of the placenta of the spotted hyena (Crocuta crocuta Erxleben), based on five specimens from early in the second third of pregnancy to full term, is presented. Resembling the dog and cat in the retention to term of a large allantois and a medium‐sized yolk sac, the hyena is unique among Carnivora in the possession of a hemochorial villous placenta, allied structurally more to that of New World monkeys than to the other carnivores. The intimacy of the fetal and maternal circulations is further increased by so‐called intraepithelial capillaries in the syncytial trophoblast. The hyena, unlike most carnivores, possesses no central hematoma or marginal deposit of pigment, and lacks specialized structures in the chorionic membrane. The cytotrophoblast, however, does undergo modifications associated with phagocytosis of histotrophe in the paraplacental regions and in the junctional zone of the placenta proper.

The principal mode of entry of maternal blood is directly into the subchorial sinus, into which uterine arteries, carried up in a crescent of gestational endometrial tissue at the margin of the placenta, empty. Smaller arteries reach the subchorial sinus in maternal septa that traverse the entire trophoblastic zone. Major arteries do not discharge blood at the base of the placenta, but basal drainage constitutes the sole means of return of blood to the uterine veins. The phylogenetic significance of the morphogenesis and vasculature of the placenta of Crocuta is discussed.
The enzyme histochemistry of the osteoclasts of normal and “ia” rats
Authors: Handelman Chester S. , Morse Anna , Irving James T.
Published: February 2005

Enzymes involved in oxidative metabolism as well as acid phosphatase were studied histochemically in osteoclasts from newborn normal rats and their littermates who suffered from a generalized defect in bone resorption (the “ia” rat). The osteoclasts of normal rats demonstrated intense activity for DPNH and TPNH diaphorase as well as succinic, malic and lactic dehydrogenase. Isocitric and glutamic dehydrogenase were less than one‐half as active but no less definite. In the “ia” rat the reaction for the diaphorases and dehydrogenases were exactly as observed in the normal. Acid phosphatase was observed in normal osteoclasts as a general cytoplasmic reaction and also in a band of concentrated activity at the junction of the cell and bone. The osteoclasts from “ia” animals had greater acid phosphatase activity (more than twice as reactive) than the normal. However, the “junctional band” was only rarely observed in this anomaly. The junctional band may represent sites into which enzymes such as acid phosphatase are secreted in the resorption process and therefore only associated with active osteoclasts. It is possible that the “ia” rat may successfully form but not secrete the enzyme.
An electron microscopic study of the cementum, Sharpey's fibers and periodontal ligament in the rat incisor
Authors: Stern Irving B.
Published: February 2005

The rat incisor is a continuously erupting, so‐called “rootless,” tooth. It differs from human or similar “rooted” teeth in that its generative cells persist at the base of the tooth. These cells are derived from the invagination of oral epithelium which forms the dental lamina and the developing dental organ. This epithelium becomes a vase‐shaped structure surrounding a condensation of connective tissue elements called the dental papilla. The cells on the labial aspect of the epithelial dental organ specialize to form enamel. The cells on the lateral and lingual aspects remain undifferentiated and are called Hertwig's epithelial sheath. The odontoblasts are derived from the dental papilla. The hard tissues of the tooth form continuously at the base, and the tooth erupts into the oral cavity where the incisal edge is worn by abrasive action during gnawing (v. Brunn, 1887; Addison and Appleton, '15; Schour and Massler, '42).

Hertwig's sheath extends from the base of the tooth to a short distance beyond the point where dentin formation commences. At this level the epithelial cells separate and the sheath disintegrates. As these cells separate, cementoblasts and collagen fibers appear adjacent to the newly forming dentinal surface. Apatite crystals are deposited in the matrix of collagen fibers and a thin layer of cementum results (Selvig, '63). Since Hertwig's sheath is persistent at the base of the tooth, this initial phase of cementogenesis is continuous.

In rooted teeth, on the other hand, initial cementogenesis is completed when the root becomes fully formed, and Hertwig's sheath has been expended. There may be subsequent progressing depositions of cementum to form one or several strata. This initial stratum is called “primary cementum” and the successive layers are called “secondary cementum.” Primary cementum contains fine fibrils arranged radially (fiber cementum). Secondary cementum generally contains cells (osteocementum) but it may be acellular. Regardless of category, cementum contains matrix (intrinsic) fibers, and also, in most cases, Sharpey's (extrinsic) fibers (Lehner and Plenk, '36; Egli, '46; Held, '51; Schmid, '51; Sicher, '62).

During the course of eruption of the rat incisor, the periodontal fibers which are attached to the cementum move with the tooth until they somehow undergo dissolution prior to the entry of the tooth into the oral cavity. A similar picture is obtained during the more limited period of eruption of rooted teeth. The mechanisms of formation, reorganization and dissolution of the periodontal fibers are all matters of biologic importance. Moreover, investigations of these phenomena may have some bearing upon understanding those pathologic processes which involve the detachment of the gingiva from teeth and the exfoliation of teeth from their sockets.
Histochemical studies on seromucous‐ and mucoussecreting cells of human salivary glands
Authors: Munger Bryce L.
Published: February 2005

Human salivary and lacrimal glands have been studied with a variety of methods to demonstrate polysaccharides in tissue section. On the basis of these studies, an attempt has been made to clarify the classification of exocrine cells. Serous cells secrete proteinaceous material without significant polysaccharide in the secretory granules such as the pancreatic acinar cell and gastric chief cell. Seromucous cells secrete a watery product, but the secretory granules contain variable amounts of mucopolysaccharide in the secretory granule. Typical seromucous cells are found in the parotid gland, lacrimal gland, submaxillary gland and eccrine sweat glands. Mucous cells liberate a viscous product rich in mucopolysaccharide. The typical mucous cell is the intestinal goblet cell. Other examples are the mucous portion of the submaxillary gland, the entire sublingual gland, bronchial gland, and Brunner's gland. Human pancreatic acinar and gastric chief cells are unique as compared to other species since the secretory granules of these cells, usually considered to be serous, contain a small amount of neutral mucopolysaccharide.
Origin and development of lens cataracts in mumps‐infected chick embryos
Authors: Robertson G. Gordon , Williamson Alice P. , Blattner Russell J.
Published: February 2005

Critical inocula of Enders strain of mumps virus were injected over the blastoderm at 36, 48, 60, 72 and 96 hours of incubation (37°C). Surviving embryos were harvested at daily intervals up to 14 days postinoculation.

Gross and microscopic observations revealed the lens to be the only organ consistently exhibiting abnormal development following inoculation with mumps virus. By comparison, maldevelopment in other structures was occasionally observed up to the third day postinoculation, but rarely in embryos surviving three or more days. Characteristic lens cataracts were observed, but only in embryos which had been inoculated prior to Hamburger‐Hamilton stage 18, i.e., prior to separation of the lens vesicle from surface ectoderm.

An analysis of the histopathogenesis of lens cataracts in embryos inoculated at stages 8–17 indicates that the differentiating lens fibers became progressively more extensively damaged as development proceeded. However, it is evident that the differentiation of new lens fibers proceeded peripherally as the more mature fibers continued to be destroyed centrally. It can be concluded that differentiating lens fibers are highly susceptible to damage by mumps virus, but the initiation of the characteristic defect occurred in our experiments only during the early formative phases of lens development.
Experimental production of perfect cyclopia by removal of the telencephalon and reversal of bilateralization in somite‐stage chicks
Authors: Rogers K. T.
Published: February 2005

The telencephalon was removed with iridectomy scissors in stages from 1 to 20 somites, with the vast majority of operated chicks being at 5 to 10 somites. The most chance of successfully producing cyclopia appears to be at 6 to 7 somites. Twelve cyclopean embryos, with operated stages ranging from 5 to 10 somites, were produced among the first 271 operations. Subsequently, 398 operations, concentrated on 9‐ to 10‐somite embryos, proved that cyclopia is very much less apt to follow this sort of operation at these stages than at the very slightly younger stages.

Serial sections of the cyclopean embryos were stained with a modification of the Bodian protargol stain. An oral hypophysis is usually present in these embryos, making them in this respect similar to the majority of cyclopean embryos for which this point is reported in the literature, but making them different from experimentally produced cyclopean amphibian embryos reported in the literature. The sequence of fusion of extrinsic ocular muscle components and the patterns of their nerves, as the cyclopean defect becomes more severe, indicates that the reversal of bilateralization is a ventralization.

Coupled with biochemical work on the chick and the more recent of the biochemical work of others on amphibia, the results allow one to suggest that experimental stimuli resulting in the cyclopean mode of development may act either on prechordal substrate or on neural tissue of telencephalon and diencephalon, or on both substrate and neural tissue, and that they may be effective over a considerable period of time, up to and including the period of actual bilateralization of the optic primordia.
A quantitative study of the effect of heat on germinal epithelium of rat testes
Authors: Chowdhury A. K. , Steinberger E.
Published: February 2005

A quantitative study of changes in the germinal epithelium of rat testes exposed to 43°C for 15 minutes was performed. Testicular tissue was studied at intervals of 2, 4, 6, 8 and 26 days after exposure to heat. The frequency distribution of the various stages of spermatogenesis, the resting spermatocytes, spermatogonia and Sertoli cells were not affected by the exposure to heat. On the other hand, primary spermatocytes in stage IX (leptotene), to and including dividing spermatocytes in stage XIV, were injured, excepting for pachytene spermatocytes in stages V and VI of spermatogenesis. The spermatids were affected by heat only in step 1 and the early part of step 2 of spermiogenesis. Those beyond step 2 continued to mature and form adult spermatozoa. The data indicate that heat produces selective damage to the germinal epithelium affecting only specific types of germinal epithelium cells.
The presence of water on the respiratory surfaces of the lung
Authors: Terry Robert James
Published: February 2005

Interest in the possibility of a fluid medium for the transport of oxygen in the respiration of terrestrial vertebrates was aroused by the author's discovery of a watery fluid in the bronchioles of human cadavers and of domestic animals. In the literature of respiration the tolerance of water injected into the lungs of living animals had been demonstrated by Claude Bernard in 1869. Water as the vehicle for oxygen in the respiration of terrestrial invertebrates has been recorded many times. The life of fishes and of invertebrates inhabiting the waters of the world is dependent upon oxygen dissolved in this medium. The present paper records: (a) The author's experience in seeking and recording evidence of the presence of a watery medium in the respiratory organs of a series of vertebrates, and (b) presents evidence in explanation of the method of oxygen transport from the termination of the bronchial system into the capillary blood‐stream of the lung. The investigation called for special techniques, apparatus and instruments; these are described. The period of investigation extended, with many interruptions, from '10 to '60; during which period reports of progress have been published.
Fine structure of the rat renal papilla
Authors: Bulger Ruth Ellen , Trump Benjamin F.
Published: February 2005

The fine structure of the rat renal papilla was studied after fixation with various fixative solutions and by using three modes of fixative application: immersion, vascular perfusion and injection of fixative into the renal pelvis. The morphology of the following was described: thin limbs of Henle's loop, collecting ducts, capillaries, interstitial cells, and interstitium. Several previously undescribed features were seen. Two types of capillaries were identified on the basis of their fine structure. Regions identified as limbs of Henle had at least two types of mural structure differing in degree of cellular interdigitation. In addition, numerous projections were seen extending from the basal cytoplasm of capillary endothelium and collecting duct epithelium through the basement membrane into the interstitium.
The visual cells of the chicken as revealed by phase contrast microscopy
Authors: Meyer David B. , Cooper Terrance G.
Published: February 2005

Phase microscopic investigations of Kolmer‐fixed, depigmented sections of the adult chicken retina have provided photomicrographic evidence of the existence of three different photoreceptors: single rods, single cones, and double cones. The rod extends the entire thickness of the visual cell layer and is characterized by a uniformly thick outer segment and a hyperboloid‐containing inner segment which is devoid of an oil droplet. The single cone is the shortest element; it contains a red oil droplet. The double cone consists of two unequal members, a tall, slender chief cone and a broad accessory cone. The chief component contains a large yellow oil droplet, whereas the accessory cone houses a small, oval, yellowish‐green droplet and a characteristically large, oval paraboloid. The rod hyperboloid and the accessory cone paraboloid contain glycogen. No colorless droplets have been observed. Owing to the close association between oil droplet color and cone type, three colored layers of oil droplets are formed within the thickness of the retina: a proximal row of red droplets (the short, single cones), an intermediate layer of yellowish‐green droplets (the accessory cones), and a distal row of yellow droplets (the tall chief cones).
Deviations in the sequence of appearance of primary centers of ossification in the feet of human fetuses with cleft lip and/or palate
Authors: Kraus Bertram S. , Ahern Suzanne
Published: February 2005

The feet of 35 human fetuses with cleft lip and/or palate and 208 human fetuses without cleft Lip or palate were cleared and stained, and their conformity to the “normal” sequence of appearance of the primary centers of ossification in the 19 post‐tarsal bones was noted. An arbitrary definition of a significant deviation from the normal sequence was established and a system of evaluating the relative severity of deviations was set up. The relative number of cleft fetuses showing deviations from the accepted sequence (42.9% ) was significantly higher than of non‐cleft fetuses (10.6%). The cleft and non‐cleft deviant fetuses were not significantly different in relative severity. There was no difference between the two series in the relative frequency with which specific bones were affected. In each series the fifth distal phalanx was most frequently affected. In both series, deviations in the order of initial ossification more frequently involved the seventh to tenth phalanges in the sequence. Asymmetry was of common occurrence in deviants of both the cleft and non‐cleft series. There was no significant difference in the number of deviant centers per fetus in the cleft and non‐cleft series.

The biological mechanisms underlying the orderly and regular sequence of appearance of ossification centers in the foot are not known, hence, the nature of the interference with the “normal” sequence cannot be described.
Growth of the face and jaws after resection of the septal cartilage in the rabbit
Authors: Sarnat Bernard G. , Wexler Manuel R.
Published: February 2005

Varying amounts of the cartilaginous nasal septum were resected in 15 growing rabbits at 21 days of age. Ten additional rabbits were used as unoperated on and operated on controls. The postoperative survival ranged from 105 to 145 days.

Within 60 to 90 days postoperatively, antemortem findings were noted in the experimental animals of a shorter snout and overeruption and malocclusion of the incisors. Postmortem gross findings of the dissected, sectioned and x‐rayed skulls of the experimental animals revealed that the snout was shorter and smaller with a severe relative mandibular prognathism, the nasal and premaxillary bones were smaller, the nasal cavity and piriform aperture were smaller than in the control animals. As a result of the shorter snout the upper incisors were lingual to the lower incisors. This was the reverse of the normal findings. In addition, the incisors were overerupted, malaligned and fractured. At the posterior border of the septal defect a marked downward and forward deflection of the nasal bones was noted. This was in contrast to the smoothly curved dorsum of the operated on and unoperated on control animals. The extent and severity of the deformity varied approximately with the extent of the septal defect.
The fine structure of rat liver sinusoids, space of Dissé and associated tissue space
Authors: Burkel William E. , Low Frank N.
Published: February 2005

Three structurally distinct zones are present in the liver sinusoid. The endothelium and basement (boundary) membrane of the portal vein extend uninterruptedly into the peripheral zone. The intermediate zone, comprising 90% or more of the length of the sinusoid, possesses a fenestrated lining and no basement membrane. The short central zone has unfenestrated endothelium and a basement membrane. Both are continuous with those of the central vein. The space of Dissé encircles all three zones of the sinusoid. It contains fat storage cells, perisinusoidal cells, numerous microvillae of liver cells and reticular fibers. These fibers are bundles of unit collagen fibers enclosed by cytoplasm of nearby cells. The space of Dissé is continuous with the tissue space at both ends of the sinusoid. The liver cells lack a basement membrane whether they abut on the space of Dissé or on the tissue space proper.

The unique feature of liver fine structure is the combination of fenestrations and lack of basement membranes in the intermediate zone of the sinusoid. Blood plasma is thereby afforded intimate contact with the parenchymal cells and has access to the tissue space at both ends of the sinusoid. This structural situation fits the known facts of liver function.
Fine structure of the lymphatic capillary and the adjoining connective tissue area
Authors: Leak L. V. , Burke J. F.
Published: February 2005

The lymphatic capillaries possess salient morphological features which differentiate them from the blood capillaries. Instead of a definitive basement lamina surrounding the lymphatic wall, there are numerous fine filaments (about 60 A in diameter) that are attached to the lymphatic endothelia at areas of increased electron density that are similar to half desmosomes. The filaments extend for varying vessel to the surrounding connective tissue. Endothelial projections occur along both the luminal and abluminal surfaces of the cell. The intercellular junctions are varied in structure along the lymphatic wall. Terminal processes of adjacent endothelial apposed without overlapping. At various points along the intercellular junction the apposed surface membranes are held in close apposition by adhesion devices, (a) zonula occludens, (b) zonula adhaerens, and (c) macula adhaerens (desmosome). Frequently open junctions are observed along the lymphatic wall. It is suggested that the areas between apposing membrane surfaces which lack attachment devices may represent specialized regions along the lymphatic wall that are easily separated and would permit the passage of excess tissue fluids and large molecules into the lumen of the lymphatic vessel. The transport of colloidal carbon particles across the endothelium in vesicles of various sizes and via intercellular junctions is demonstrated.
Perfusion‐fixation of the brain with chrome‐osmium solutions for the rapid Golgi method
Authors: Morest D. Kent , Morest R. R.
Published: February 2005

The characteristics of rapid Golgi impregnations of neurons in the brains of opossums, rats, rabbits, chinchillas, and cats, obtained with a method employing intracardiac perfusion with osmium tetroxide‐dichromate fixatives, are reported. Observations on all subdivisions of the brain were compared with immersion‐fixed Golgi preparations and formalin‐perfused brains prepared by Nissl or reduced silver methods. Perfusion‐fixation yielded more uniform and extensive Golgi impregnations, which were more representative of the varieties of neural structures than in immersion‐fixed preparations. The morphological details of fine neuronal processes, delicate dendritic branchlets and spines, and fine elements of the axonal plexuses were more clearly and consistently demonstrable. Observations with the polarizing microscope suggested that the Golgi impregnations contained silver dichromate and/or silver monochromate. The procedures and the predictability, nature, and histological reliability of the rapid Golgi method are discussed.