Histo-morphological effects on equine synovium after arthroscopic synovectomy using two different motorized synovial resectors and two different intensities

The purpose of the study was to determine the histo-morphological effects on villous synovium after synovectomy using two different motorized synovial resectors and two different intensities ex-vivo. Thirty-three (n = 33) equine metacarpophalangeal/metatarsophalangeal joints were used. Synovectomy was performed along the dorsomedial/dorsolateral synovium (n = 66) using two motorized synovial resectors (aggressive full radius resector, AFRR, used at two intensities: single treatment, n = 24 vs. triple treatment, n = 21 vs. aggressive meniscus side cutter, AMSC, n = 21). Arthroscopic images were evaluated blindly for resector type and intensity. Histological images were evaluated descriptive for synovial morphology and the extent of tissue loss using a microscopic scale. Scanning electron microscopy described the synovial morphology. The synovectomized areas were specific for each resector used and distinguishable from arthroscopic images. The AFRR demonstrated a clear demarcation between treated and non-treated areas and removed the stratum synoviale completely including parts of the underlying stratum fibrosum. In contrast, the AMSC showed less clear demarcation, villous scaffolds and no involvement of the stratum fibrosum. Triple intense treated AFFR samples resulted in significantly deeper lesions compared to single treatments (p = 0.037) but could not be distinguished on arthroscopic images. The morphological effects on villous synovium differ according to the resector type used. The extent of synovial tissue loss cannot be estimated from arthroscopic images but histologically. The type and use of motorized synovial resector determines the morphological alterations of the treated synovium. Arthroscopic control is considered unsuitable to control synovectomy depth.

Assessment of potential neuropathic changes in cattle after cautery disbudding

Disbudding of calves is a standard husbandry procedure to reduce the risk of injuries to other cattle and to workers. Whereas acute pain resulting from disbudding has been studied extensively, little is known about chronic pain as a potential long-term consequence. The goal of the present study was to investigate possible morphological changes in the cornual nerve as a function of disbudding. Samples were collected from 17 randomly selected bulls and from 21 calves from a prospective clinical study. Among the calves, 13 were disbudded and 8 were sham-disbudded. Out of the disbudded calves, 4 showed signs of chronic pain. In all the animals, the infraorbital nerve was used as a methodological check. Morphological analysis included measuring minimal diameters of the axons present in both the cornual and infraorbital nerves. Sympathetic fibers were identified as based on the presence of Tyroxine hydroxylase (TH). TH-negative fibers were considered afferents. Trigeminal ganglia from the calves were immunostained for glial fibrillary acidic protein (GFAP) and Activating transcription factor 3 (ATF3). R. cornualis and N. infraorbitalis differed in terms of axon diameters and proportion of TH-positive fibers. Weak evidence (p > .091) of a difference in axon diameters between control and disbudded calves was found in R. cornualis, but the proportion of TH-positive fibers was alike in both groups. Average glial envelope and the percentages of ATF3-positive neurons revealed no difference between calves with and without signs of pain. Thus, available evidence is insufficient to support neuropathic changes as a result of disbudding in calves.

Ranid Herpesvirus 3 and Proliferative Dermatitis in Free-Ranging Wild Common Frogs (Rana Temporaria)

Amphibian pathogens are of current interest as contributors to the global decline of amphibians. However, compared with chytrid fungi and ranaviruses, herpesviruses have received relatively little attention. Two ranid herpesviruses have been described: namely, Ranid herpesvirus 1 (RHV1) and Ranid herpesvirus 2 (RHV2). This article describes the discovery and partial characterization of a novel virus tentatively named Ranid herpesvirus 3 (RHV3), a candidate member of the genus Batrachovirus in the family Alloherpesviridae. RHV3 infection in wild common frogs (Rana temporaria) was associated with severe multifocal epidermal hyperplasia, dermal edema, a minor inflammatory response, and variable mucous gland degeneration. Intranuclear inclusions were numerous in the affected epidermis together with unique extracellular aggregates of herpesvirus-like particles. The RHV3-associated skin disease has features similar to those of a condition recognized in European frogs for the last 20 years and whose cause has remained elusive. The genome of RHV3 shares most of the features of the Alloherpesviruses. The characterization of this presumptive pathogen may be of value for amphibian conservation and for a better understanding of the biology of Alloherpesviruses.

High-content analysis of factors affecting gold nanoparticle uptake by neuronal and microglial cells in culture

Owing to their ubiquitous distribution, expected beneficial effects and suspected adverse effects, nanoparticles are viewed as a double-edged sword, necessitating a better understanding of their interactions with tissues and organisms. Thus, the goals of the present study were to develop and present a method to generate quantitative data on nanoparticle entry into cells in culture and to exemplarily demonstrate the usefulness of this approach by analyzing the impact of size, charge and various proteinaceous coatings on particle internalization. N9 microglial cells and both undifferentiated and differentiated SH-SY5Y neuroblastoma cells were exposed to customized gold nanoparticles. After silver enhancement, the particles were visualized by epipolarization microscopy and analysed by high-content analysis. The value of this approach was substantiated by assessing the impact of various parameters on nanoparticle uptake. Uptake was higher in microglial cells than in neuronal cells. Only microglial cells showed a distinct size preference, preferring particles with a diameter of 80 nm. Positive surface charge had the greatest impact on particle uptake. Coating with bovine serum albumin, fetuin or protein G significantly increased particle internalization in microglial cells but not in neuronal cells. Coating with wheat germ agglutinin increased particle uptake in both N9 and differentiated SH-SY5Y cells but not in undifferentiated SH-SY5Y cells. Furthermore, internalization was shown to be an active process and indicators of caspase-dependent apoptosis revealed that gold nanoparticles did not have any cytotoxic effects. The present study thus demonstrates the suitability of gold nanoparticles and high-content analysis for assessing numerous variables in a stringently quantitative and statistically significant manner. Furthermore, the results presented herein showcase the feasibility of specifically targeting nanoparticles to distinct cell types.

Clinicopathological Phenotype of Autosomal Recessive Cholesterol Deficiency in Holstein Cattle

BACKGROUND

Cholesterol deficiency (CD), a newly identified autosomal recessive genetic defect in Holstein cattle, is associated with clinical signs of diarrhea, failure to thrive, and hypocholesterolemia.

HYPOTHESIS/OBJECTIVES

The objective is to describe the clinicopathological phenotype of affected Holstein cattle homozygous for the causative apolipoprotein B gene (APOB) mutation.

ANIMALS

Six Holstein cattle, 5 calves with a clinical history of chronic diarrhea, and 1 heifer with erosions in the buccal cavity and neurologic symptoms were admitted to the Clinic for Ruminants.

METHODS

This case review included a full clinical examination, a complete blood count, blood chemistry, and measurements of cholesterol and triglycerides. The animals were euthanized and necropsied. A PCR-based direct gene test was applied to determine the APOB genotype.

RESULTS

All 6 animals were inbred, could be traced back to the sire Maughlin Storm, and were confirmed homozygous for the APOB mutation. The clinical phenotype included poor development, underweight, and intermittent diarrhea in the calves, and neurologic signs in the heifer included hypermetria and pacing. Hypocholesterolemia and low triglycerides concentrations were present in all animals. The pathological phenotype of all animals was steatorrhea with enterocytes of the small intestine containing intracytoplasmic lipid vacuoles. The peripheral nervous system of the heifer displayed degenerative changes.

CONCLUSIONS AND CLINICAL IMPORTANCE

Suspicion of CD in Holstein cattle is based on the presence of chronic diarrhea with no evidence of primary infections. Confirmation of the associated APOB gene mutation is needed. Additionally, the heifer demonstrated primarily signs of neurologic disease providing an unexpected phenotype of CD.

Pododermatitis in Captive and Free-Ranging Greater Flamingos (Phoenicopterus roseus)

Pododermatitis is frequent in captive flamingos worldwide, but little is known about the associated histopathologic lesions. Involvement of a papillomavirus or herpesvirus has been suspected. Histopathologic evaluation and viral assessment of biopsies from 19 live and 10 dead captive greater flamingos were performed. Selected samples were further examined by transmission electron microscopy and immunohistochemistry. Feet from 10 dead free-ranging greater flamingos were also evaluated. The histologic appearance of lesions of flamingos of increasing age was interpreted as the progression of pododermatitis. Mild histologic lesions were seen in a 3-week-old flamingo chick with no macroscopic lesions, and these were characterized by Micrococcus-like bacteria in the stratum corneum associated with exocytosis of heterophils. The inflammation associated with these bacteria may lead to further histologic changes: irregular columnar proliferations, papillary squirting, and dyskeratosis. In more chronic lesions, hydropic degeneration of keratinocytes, epidermal hyperplasia, and dyskeratosis were seen at the epidermis, as well as proliferation of new blood vessels and increased intercellular matrix in the dermis. Papillomavirus DNA was not identified in any of the samples, while herpesvirus DNA was seen only in a few cases; therefore, these viruses were not thought to be the cause of the lesions. Poor skin health through suboptimal husbandry may weaken the epidermal barrier and predispose the skin to invasion of Micrococcus-like bacteria. Histologic lesions were identified in very young flamingos with no macroscopic lesions; this is likely to be an early stage lesion that may progress to macroscopic lesions.

In vitro rescue of FGA deletion by lentiviral transduction of an afibrinogenemic patient's hepatocytes

BACKGROUND

Congenital afibrinogenemia is a rare inherited autosomal recessive disorder in which a mutation in one of three genes coding for the fibrinogen polypeptide chains Aα, Bβ and γ results in the absence of a functional coagulation protein. A patient with congenital afibrinogenemia, resulting from an FGA homozygous gene deletion, underwent an orthotopic liver transplant that resulted in complete restoration of normal hemostasis. The patient's explanted liver provided a unique opportunity to further investigate a potential novel treatment modality.

OBJECTIVE

To explore a targeted gene therapy approach for patients with congenital afibrinogenemia.

METHODS AND RESULTS

At the time of transplant, the patient's FGA-deficient hepatocytes were isolated and transduced with lentiviral vectors encoding the human fibrinogen Aα-chain. FGA-transduced hepatocytes produced fully functional fibrinogen in vitro.

CONCLUSIONS

Orthotopic liver transplantation is a possible rescue treatment for failure of on-demand fibrinogen replacement therapy. In addition, we provide evidence that hepatocytes homozygous for a large FGA deletion can be genetically modified to restore Aα-chain protein expression and secrete a functional fibrinogen hexamer.

Prevalence of keel bone deformities in Swiss laying hens

The goal of this study was to evaluate the prevalence of keel bone deformities of laying hens in Switzerland. The keel bones of 100 end-of-lay hens from each of 39 flocks (3900 in total) were palpated. On average, 25·4% of the hens had moderately or severely deformed keel bones and the overall prevalence including slight deformities was 55%. 3. Variation between flocks was considerable. Thus, the prevalence of moderately or severely deformed keel bones ranged from 6 to 48%, and the overall prevalence including slight deformities ranged from 20 to 83%. Aviary housing was associated with a higher prevalence of total, and severe or moderate deformations, compared with floor pens. There were no significant differences in the number of deformities between the different plumage colours, hybrids or perch materials.

Emergence of Canine Distemper Virus Strains With Modified Molecular Signature and Enhanced Neuronal Tropism Leading to High Mortality in Wild Carnivores

An ongoing canine distemper epidemic was first detected in Switzerland in the spring of 2009. Compared to previous local canine distemper outbreaks, it was characterized by unusually high morbidity and mortality, rapid spread over the country, and susceptibility of several wild carnivore species. Here, the authors describe the associated pathologic changes and phylogenetic and biological features of a multiple highly virulent canine distemper virus (CDV) strain detected in and/or isolated from red foxes ( Vulpes vulpes), Eurasian badgers ( Meles meles), stone ( Martes foina) and pine ( Martes martes) martens, from a Eurasian lynx ( Lynx lynx), and a domestic dog. The main lesions included interstitial to bronchointerstitial pneumonia and meningopolioencephalitis, whereas demyelination—the classic presentation of CDV infection—was observed in few cases only. In the brain lesions, viral inclusions were mainly in the nuclei of the neurons. Some significant differences in brain and lung lesions were observed between foxes and mustelids. Swiss CDV isolates shared together with a Hungarian CDV strain detected in 2004. In vitro analysis of the hemagglutinin protein from one of the Swiss CDV strains revealed functional and structural differences from that of the reference strain A75/17, with the Swiss strain showing increased surface expression and binding efficiency to the signaling lymphocyte activation molecule (SLAM). These features might be part of a novel molecular signature, which might have contributed to an increase in virus pathogenicity, partially explaining the high morbidity and mortality, the rapid spread, and the large host spectrum observed in this outbreak.

Effects of housing, perches, genetics, and 25-hydroxycholecalciferol on keel bone deformities in laying hens

Several studies have shown a high prevalence of keel bone deformities in commercial laying hens. The aim of this project was to assess the effects of perch material, a vitamin D feed additive (25-hydroxyvitamin D(3); HyD, DSM Nutritional Products, Basel, Switzerland), and genetics on keel bone pathology. The study consisted of 2 experiments. In the first experiment, 4,000 Lohmann Selected Leghorn hens were raised in aviary systems until 18 wk of age. Two factors were investigated: perch material (plastic or rubber-coated metal) and feed (with and without HyD). Afterward, the hens were moved to a layer house with 8 pens with 2 aviary systems. Daily feed consumption, egg production, mortality, and feather condition were evaluated. Every 6 wk, the keel bones of 10 randomly selected birds per pen were palpated and scored. In the second experiment, 2,000 Lohmann Brown (LB) hens and 2,000 Lohmann Brown parent stock (LBPS) hens were raised in a manner identical to the first experiment. During the laying period, the hens were kept in 24 identical floor pens but equipped with different perch material (plastic or rubber-coated metal). The same variables were investigated as in the first experiment. No keel bone deformities were found during the rearing period in either experiment. During the laying period, deformities gradually appeared and reached a prevalence of 35% in the first experiment and 43.8% in the second experiment at the age of 65 and 62 wk, respectively. In the first experiment, neither HyD nor the aviary system had any significant effect on the prevalence of keel bone deformities. In the second experiment, LBPS had significantly fewer moderate and severe deformities than LB, and rubber-coated metal perches were associated with a higher prevalence of keel bone deformities compared with plastic perches. The LBPS laid more but smaller eggs than the LB. Again, HyD did not affect the prevalence of keel bone deformities. However, the significant effect of breed affiliation strongly indicates a sizeable genetic component that may provide a basis for targeted selection.

Intestinal Atresia and Ectopia in a Bovine Fetus

A 2-year-old Red Holstein cow was presented with uterine torsion at 235 days of pregnancy. The fetus extracted by cesarean section had weak vital signs and marked abdominal distention. An edematous pouch that contained tubular structures with peristaltic activity was associated with the umbilical cord. Because of poor prognosis, both dam and fetus were euthanized. At necropsy, the fetus had severe distention of the forestomachs, abomasum, and proximal small intestine; absence of distal small intestine, cecum, and proximal colon; atresia of the 2 blind ends of the intestine; and atrophy of distal colon and rectum. The tubular structures associated with the umbilical cord were identified as the segments of intestine that were absent in the fetus. Intestinal atresia combined with ectopia may be caused by local ischemia during temporary herniation and rotation of the fetal gut into the extraembryonic coelom. The close connection between ectopic intestine and amniotic sheath of the umbilical cord in this case may have facilitated vascularization and allowed development and viability of the ectopic intestine.

[Swiss warmblood horse with symptoms of hereditary equine regional dermal asthenia without mutation in the cyclophylin B gene (PPIB)]

Hereditary equine dermal asthenia (HERDA) is an autosomal recessive skin disease that affects predominantly Quarter Horses and related breeds. Typical symptoms are easy bruising and hyperextensible skin on the back. The prognosis is guarded, as affected horses cannot be ridden normally and are often euthanised. In the Quarter Horse, HERDA is associated with a mutation in cyclophilin B (PPIB), an enzyme involved in triple helix formation of collagen. Here we describe the case of a Swiss Warmblood filly with symptoms of HERDA without PPIB-mutation and in which we also could exclude Ehlers-Danlos syndrome Type IV, VI, VIIA, VIIB and VIIC (dermatosparaxis type) as etiological diseases.

Effects of the two production programs 'Naturafarm' and 'conventional' on the prevalence of non-perforating abomasal lesions in Swiss veal calves at slaughter

Non-perforating abomasal lesions are a considerable problem affecting more than half the population of veal calves. The objective of the present study was to assess the prevalence of pyloric and fundic abomasal lesions in Swiss veal calves at slaughter and to compare the occurrence of non-perforating abomasal lesions between two different production programs ('Naturafarm' and 'conventional'). 'Conventional'-production settings met the minimal standards as defined by the Swiss animal welfare legislation, whereas 'Naturafarm' production complied with increased animal welfare requirements. In order to identify risk factors for the development of abomasal lesions, information on management, housing, and feeding was obtained by a questionnaire. A total of 125 abomasa were randomly selected in one large abattoir. They were examined macroscopically, and the occurence of lesions in either the fundic or pyloric region of the abomasum was recorded separately. Animals raised in the 'conventional'-production setting revealed a significantly higher prevalence of lesions in the fundic part. Factors significantly affecting the prevalence of non-perforating lesions in the fundic part were the 'conventional'-production environment, including missing access to an outside pen, missing access to water and straw as the only roughage, feeding by bucket and the liquid milk by-product Protofit in combination with the powder Sprayfit.

Immunohistochemical demonstration of lumbar intervertebral disc innervation in the dog

Low back pain is a common ailment in dogs, particularly in specific breeds such as the German shepherd dog. A number of structures such as facet joint capsules, ligaments, dorsal root ganglia, periosteum, vertebral endplates and meninges have been associated with this condition. Yet, in spite of all diagnostic efforts, the origin of pain remains obscure in a substantial proportion of all cases. A further structure often being involved in vertebral column disorders is the intervertebral disc. The presence of nerves, however, is a precondition for pain sensation and, consequently, structures lacking innervation can be left out of consideration as a cause for low back pain. Nerve fibres have been demonstrated at the periphery of the intervertebral disc in man, rabbit and rat. With regard to the dog, however, the extent of intervertebral disc innervation is still being disputed. The goal of the present study, therefore, was to substantiate and expand current knowledge of intervertebral disc innervation. Protein gene product (PGP) 9.5 was used for immunohistochemical examination of serial transversal and sagittal paraffin sections of lumbar discs from adult dogs. This general marker revealed nerve fibres to be confined to the periphery of the intervertebral discs. These results indicate that even limited pathological processes affecting the outer layers of the intervertebral disc are prone to cause low back pain.

Doppler sonography of the medial arterial blood supply to the coxofemoral joints of 36 medium to large breed dogs and its relationship with radiographic signs of joint disease

The medial arterial supply to 68 of the 72 coxofemoral joints of 36 medium to large breed dogs was examined ultrasonographically. The medial circumflex femoral artery and three branches were identified; the artery and its transverse branch were identified in all 68 joints, and the deep branch was identified in 61 joints, and the ascending branch was identified in 63. However, the acetabular and obturator branches were not identified. The pulsatility index, the mean velocity and the peak systolic velocity of the medial circumflex femoral artery were determined and associated with a radiographic score of degenerative coxofemoral joint disease and a lath distraction index (LDI). In joints with a LDI greater than 0.35, the pulsatility index was significantly lower (P=0.023) and its mean velocity was higher (P=0.005). However, no significant associations were observed in individual dogs when the measurements in both joints were taken into account.

Primary ciliary dyskinesia with situs inversus totalis, hydrocephalus internus and cardiac malformations in a dog

A nine-month-old golden retriever bitch was presented with exercise intolerance and recurrent nasal discharge. Based on clinical, radiographic and ultrasonographic examination, a diagnosis of rhinitis, situs inversus totalis and tricuspid valve insufficiency was established. The results of video- and electron microscopy studies of the respiratory epithelium were compatible with primary ciliary dyskinesia (PCD). However, no evidence of a primary ultrastructural defect of the cilia was found. The dog was euthanased because of the poor prognosis. At necropsy, a hydrocephalus internus and a subaortic stenosis were additionally diagnosed. PCD, in combination with situs inversus, has been previously reported in golden retrievers, but without a concomitant hydrocephalus internus. Furthermore, concomitant occurrence of internal cardiac malformation and PCD has not previously been reported in the dog.

Scanning electron microscopy of the canine placenta

The zonary placenta of the dog is peculiar in providing three morphologically and functionally distinct areas for transplacental exchange: the endotheliochorial labyrinth of the girdle zone, the hemochorial hemophagous zone of the marginal hematoma and the epitheliochorial free polar zone. Besides, the yolk sac persists throughout pregnancy. Scanning electron microscopy (SEM) was used to study these structures comprehensively with special emphasis on natural surfaces because of their relevance for exchange processes. Unequal cell diameter was typical for trophoblast cells. Surface specializations were observed on trophoblast cells lining the marginal hematoma, the free polar zone and the glandular chambers as well as on uterine epithelial cells of the glandular chambers and of the deep glands. In addition, maternal and fetal endothelial cells in the labyrinth showed major differences. Whereas fetal endothelial cells were extremely thin and polygonal in shape, maternal vessels were lined by thick endothelial cells exhibiting a complex interdigitation pattern of cytoplasmic processes. Thus, most of the natural surfaces could readily be distinguished by SEM due to their typical appearance.

Distinction of gastric Helicobacter spp. in humans and domestic pets by scanning electron microscopy

BACKGROUND

A number of different Helicobacter spp. can colonize the stomach of humans and domestic pets. Difficulties encountered with primary isolation of these spiral microorganisms and their unusual inertia with respect to biochemical reactions still represent considerable obstacles to their characterization with classic tools. In addition, the high degree of similarity in the 16S rRNA sequence hampers differentiation of Helicobacter spp. using routine molecular biological assays.

MATERIALS AND METHODS

Samples from experimentally monoinfected mice, of naturally infected hosts, and of cultured strains were examined by scanning electron microscopy (SEM). In parallel, all samples were analyzed by molecular techniques to ascertain the Helicobacter spp. involved.

RESULTS

Using the mouse samples as a reference, microorganisms found in naturally infected hosts were identified by SEM as belonging to H. pylori, H. felis, or a group consisting of H. bizzozeronii and H. heilmannii. A further spiral microorganism with unique morphology was found in a dog that was positive for H. salomonis, but the organism could not be recovered from experimentally infected mice. In culture, most Helicobacter strains lost their ultrastructural characteristics.

CONCLUSIONS

When gastric Helicobacter spp. were collected from their natural habitat and examined by SEM, relevant differences could be detected between H. felis, H. bizzozeronii and H. heilmannii, and H. salomonis, respectively. SEM, therefore, seems to be a useful auxillary tool for the distinction of various gastric Helicobacter spp. as based on their ultrastructure.

Exposure of rainbow trout (Oncorhynchus mykiss) to nonylphenol is associated with an increased chloride cell fractional surface area

Nonylphenol is a biodegradation product of a widely used group of non-ionic detergents. Because of its ubiquitous distribution and persistence, nonylphenol is present in surface waters as a pollutant. Little is known about its biological effects at environmentally relevant concentrations other than its action as a xenoestrogen. The goal of the present paper was to study the trout gill surface epithelium as the major interface between fish and water in view of possible morphological alterations due to exposure to nonylphenol. Rainbow trout were intermittently exposed to 10 micrograms/l nonylphenol and gill samples from experimental and control animals were investigated by scanning electron microscopy. Gill surface epithelium was scrutinised for changes in chloride cell density and their status regarding cell surface modifications. In addition, chloride cell fractional surface area (CCFA) was determined by morphometrical methods. Statistical analysis revealed a highly significant increase of CCFA in animals exposed to nonylphenol as compared to control animals (P = 0.0001). Semi-quantitative assessment of the other parameters suggested a higher chloride cell density and a larger proportion of chloride cells bearing microvilli. Taken together, these results provide evidence that exposure of trout to nonylphenol is associated with a substantial increase in the active interface of chloride cells with water. We interpret these findings as being a means to further the fish's capacity for calcium exchange.

Ultrastructural evidence of transplacental transport of immunoglobulin G in bitches

In dogs, passive immunity is conferred to fetuses and neonates by the transfer of maternal immunoglobulin G through the placenta during the last trimester of pregnancy and via the mammary gland after parturition, respectively. However, morphological evidence of transplacental transport is still lacking. The aim of the present study was to localize maternal immunoglobulin G in the labyrinthine zone and in the haemophagous zone of the canine placenta by means of immunohistochemistry and immunocytochemistry. In the labyrinthine zone, immunoglobulin G was detected in all the layers of the materno-fetal barrier including the fetal capillaries. Immunoreactivity was particularly prominent in maternal basement membrane material as well as in the syncytiotrophoblast. However, this evidence of transplacental transport of immunoglobulin G originated from a limited number of unevenly distributed maternal vessels only. In the cytotrophoblast of the haemophagous zone, immunoglobulin G was localized to phagolysosomes at various stages but was never detected within fetal vessels. The results indicate that maternal immunoglobulin G is degraded in cytotrophoblast cells of the hemophagous zone and, therefore, that transplacental transport is restricted to a subpopulation of maternal vessels in the labyrinthine zone.

Ultrastructural evidence of transplacental transport of immunoglobulin G in bitches

In dogs, passive immunity is conferred to fetuses and neonates by the transfer of maternal immunoglobulin G through the placenta during the last trimester of pregnancy and via the mammary gland after parturition, respectively. However, morphological evidence of transplacental transport is still lacking. The aim of the present study was to localize maternal immunoglobulin G in the labyrinthine zone and in the haemophagous zone of the canine placenta by means of immunohistochemistry and immunocytochemistry. In the labyrinthine zone, immunoglobulin G was detected in all the layers of the materno-fetal barrier including the fetal capillaries. Immunoreactivity was particularly prominent in maternal basement membrane material as well as in the syncytiotrophoblast. However, this evidence of transplacental transport of immunoglobulin G originated from a limited number of unevenly distributed maternal vessels only. In the cytotrophoblast of the haemophagous zone, immunoglobulin G was localized to phagolysosomes at various stages but was never detected within fetal vessels. The results indicate that maternal immunoglobulin G is degraded in cytotrophoblast cells of the hemophagous zone and, therefore, that transplacental transport is restricted to a subpopulation of maternal vessels in the labyrinthine zone.

Localization of glucose-6-phosphatase activity and carbohydrates in boar caput epididymal principal cells

Unidentified tubulovesicular profiles have been reported in the apical cytoplasm of boar caput epididymal principal cells in addition to vesicles considered to be involved in endocytosis and secretion. The main aim of the present study was to clarify the character of these organelles and to differentiate them from the endocytic apparatus. Glucose-6-phosphatase (G6Pase) activity was determined as the reporter enzyme of the endoplasmic reticulum (ER) and phosphotungstic acid was used to visualize carbohydrate moieties in both the proximal and distal caput. Phosphotungstic acid revealed the glycocalyx of the endocytic apparatus, which was similar in both regions studied, and also stained specific granules of the proximal caput. Glucose-6-phosphatase showed the tubulovesicular profiles to be sparsely granulated ER that was poorly developed in the proximal caput and very abundant in the apical cytoplasm of the distal caput principal cells. The function of such large amounts of sparsely granulated ER with corresponding G6Pase activity in caput epididymal principal cells is unknown.

The glandular chambers of the placenta of the bitch in the second third of pregnancy (day 30-44): an ultrastructural, ultrahistochemical and lectinhistochemical investigation

The present study represents the first comprehensive investigation of the glandular chambers of the placenta of the bitch. We examined the glandular chambers by SEM, TEM, ultrahistochemical and lectinhistochemical methods. The glandular epithelium is a high columnar epithelium with club-shaped apical protrusions bearing short microvilli. The epithelium forms extensive folds which fill up most of the lumen of the glandular chambers. Proceeding to the placental labyrinth, the glandular chambers are covered by the tips of the chorionic tufts. The trophoblast and the glandular epithelium are separated by a thick layer of secretions. The ultrastructure cytology of the columnar epithelium is characterized by several Golgi complexes and abundant apical-located mucus vesicles with a positive dialysed iron reaction. Lectin histochemistry reveals in general a strong reaction of these mucus vesicles with all lectins used. The mucus in the lumen of the glandular chamber reacts strongly with WGA, NeuWGA, LPA and ConA. The trophoblastic villi projecting into the lumen of the glandular chambers are covered by a pseudostratified epithelium consisting of a flat basal layer and a superficial columnar one. Its cytoplasm is filled with large fusing vacuoles containing longish screw-shaped structures. No morphological equivalent of absorption is found. According to the ultrastructure of the trophoblast, the significance of the mucus in the glandular chambers in stopping the invasive growth of the trophoblast is discussed.

The junctions between efferent ductules and epididymal duct in the boar

Sperm transit through the male excurrent duct system is dependent on complete luminal patency. Since male excurrent ducts are derived embryologically from originally separate structures, the junctions between mesonephric tubules and the mesonephric duct are of major interest with respect to obstructive disorders. Therefore, we investigated the junctions between efferent ductules and epididymal duct in adult boars by means of serial semithin and ultrathin sections. Based on the anastomosing pattern and on the site of transition from low columnar, ciliated epithelium to high columnar, non-ciliated epithelium, three different types of anastomoses were identified, one of which was associated with luminal stenosis and sperm accumulation. The occurrence of end-to-side junctions with the epithelial transition being localized within the lumen of the tributary may thus impede normal sperm transport.

Ultrastructural validation of an improved culture system for boar efferent duct epithelium

A tissue culture system in which cells retain defined ultrastructural and functional characteristics was established to provide a basis for functional investigations of the efferent ductules in boars. A currently used culture protocol for rat epididymal epithelium was used as a starting point and was subsequently modified because of unsatisfactory results. Epithelial plaques were isolated by mechanical uncoiling of the ductules and two sequential enzymatic digestion steps. Plaques were seeded onto extracellular matrix-coated permeable membranes and maintained in a two-chamber system. Samples taken before seeding and after 7 days in culture were processed for transmission and scanning electron microscopy. Perfusion-fixed material from earlier studies served as a reference to assess ultrastructural preservation. In addition, endocytotic activity was investigated by adding cationized ferritin to the culture medium on day 8 before fixation. At the end of the disaggregation procedure, cells were cuboidal, while cilia, microvilli and cell organelles were well preserved. After 7 days in culture, three types of cell formation were observed: cysts, pseudotubules and epithelial sheets. Cell sheets were made up of closely juxtaposed cells bearing motile kinocilia and exhibiting well-developed polar differentiation, as judged from the localization of cell junctions and organelles. Although it did not return to the values of native material, cell height was greater than that of cells grown according to the pre-existing protocol. Furthermore, preferential uptake of ferritin by principal cells after 7 days in culture was demonstrated. Preservation of these fundamental characteristics of the in vivo state corroborates that our in vitro system will furnish reliable information.

Morphological characteristics of boar efferent ductules and epididymal duct

The aim of the present study was to provide a comprehensive morphological analysis of the porcine epididymis in view of the specific functions being performed in different regions of this organ. Blood supply and microvasculature of efferent ductules and epididymal duct were investigated by means of corrosion casts which were analysed macroscopically and by scanning electron microscopy. This revealed blood supply to the testis and epididymis to be closely related. The capillary pattern was typical for the efferent ductules, the caput, corpus, and distal cauda epididymidis, respectively. Corrosion casts were also used to visualize the course of the efferent ductules themselves. Tissue samples from different regions of the efferent ductules and epididymal duct were examined by light microscopy and both scanning and transmission electron microscopy, with special attention being payed to transitional areas. Morphological criteria allowed the distinction of three segments within the efferent ductules and of the initial segment, proximal caput, distal caput, corpus, proximal cauda, and distal cauda regions of the epididymal duct. Components of the endocytic apparatus of efferent ductule principal cells were identified by ferritin uptake. Ultrastructural evidence of absorption in the epididymal duct was particularly prominent in proximal and distal caput. Extensive cisternae of rough endoplasmic reticulum and a well-developed Golgi apparatus were indicative of active protein synthesis and secretion especially in the distal caput and corpus regions. However, assignment of various organelles in principal cells of the epididymal duct to either absorptive or secretory pathways still remains tentative.

Improved preservation of rat epididymal sperm for high-resolution low-voltage scanning electron microscopy (HR-LVSEM)

Various fixation protocols were used in an attempt to improve preservation of rat epididymal sperm for high-resolution low-voltage scanning electron microscopy (HR-LVSEM). Wash solutions and fixatives of different composition and osmolarity were tested. Paraformaldehyde and glutaraldehyde concentrations were varied between 0.5% and 3%. Ruthenium red was tested as an additive in both primary fixation and postfixation, or in postfixation alone. HR-LVSEM revealed various degrees of ruffing, folding, blebbing, and peeling off of the plasma membrane, as well as holes of different sizes. The plasma membrane overlying the acrosome and the connecting piece proved to be particularly sensitive to varying fixation conditions. Consistent topographical differences were revealed among the different domains over the sperm head. Most of the differences were considered to be artifacts. Their consistency, however, suggests that structural and biochemical differences exist either within the membrane or in the structures subjacent to the membrane. Primary fixation turned out to be less critical than postfixation. Preservation of a smooth plasma membrane without holes could only be achieved when primary fixation in low aldehyde concentrations, with or without ruthenium red, was followed by postfixation with OSO4 and 1,000 ppm ruthenium red. Examination of thin sections of the same material confirmed that even a considerable number of small holes are difficult to detect in transmission electron microscopy. These results show that with the recent increase in resolution of LVSEM there is need for further effort to improve sample processing.

Transport of biologically active material in laser cutting

The transport of biologically active material during laser cutting with CO2 and Er lasers is demonstrated. This transport mechanism removes particles from the surface of gelatin, agar, and liver samples into the depth of the laser-formed craters. The transport phenomenon is explained by a contraction and condensation of enclosed hot water vapor. We show by cultivating transported bacteria in agar that biological particles can survive the shock of the transport. Determination of the numbers of active cells evidences a more pronounced activity of the cultivated bacteria after impact with an Er laser than with a CO2 laser.