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1.
Reprod Domest Anim ; 52(2): 235-242, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27925313

ABSTRACT

In the last decade, progenitor cells isolated from dissociated endometrial tissue have been the subject of many studies in several animal species. Recently, endometrial cells showing characteristics of mesenchymal stem cells (MSC) have been demonstrated in human, pig and cow uterine tissue samples. The aim of this study was the isolation and characterization of stromal cells from the endometrium of healthy bitches, a tissue that after elective surgery is routinely discarded. Multipotent stromal cells could be isolated from all bitches enrolled in the study (n = 7). The multipotency of cells was demonstrated by their capacity to differentiate into adipocytic, osteocytic and chondrocytic lineages. Clonogenicity and cell proliferation ability were also tested. Furthermore, gene expression analysis by RT-PCR was used to compare the expression of a set of genes (CD44, CD29, CD34, CD45, CD90, CD13, CD133, CD73, CD31 CD105, Oct4) with adipose tissue-derived MSC. Stromal cells isolated from uterine endometrium showed similar morphology, ability of subculture and plasticity, and also expressed a panel of genes comparable with adipose tissue-derived MSC. These data suggest that endometrial stromal cells fulfil the basic criteria proposed by the "Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy" for the identification of mesenchymal stem cells. Although endometrial mesenchymal stem cells (EnMSC) showed a lower replicative ability in comparison with adipose tissue-derived MSC, they could be considered a cell therapeutic agent alternative to adipose tissue or bone marrow-derived MSC in dog.


Subject(s)
Cell Proliferation/physiology , Dogs/physiology , Endometrium/cytology , Stem Cells/physiology , Animals , Cell Culture Techniques , Cells, Cultured , Female
2.
J Small Anim Pract ; 55(4): 235-7, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24697408

ABSTRACT

A five-year-old female cat weighing 3 kg was presented by the owner after noticing a large pink, bilobed mass protruding through the vulva during labour. The cat was in good condition, with appropriate lactation, and the newborn kittens were nursing normally. The uterus was not reverted or invaginated at examination, and there was rupture of the mesovarium, mesometrium and uterine-vaginal connection around the cervix. Manual reduction of the prolapsed uterus was not possible because of torn ligaments. A coeliotomy was performed to remove the ovaries, and the apex of the uterine horns was passed by the vaginal route. The remaining part of the mesometrium was disconnected, and the prolapsed uterus was removed. The queen and kittens were discharged from the hospital on the second day after surgery. An unusual feature of this case is that the prolapse was complete, without eversion of any part of the uterus through a vaginal tear.


Subject(s)
Cat Diseases/diagnosis , Uterine Prolapse/veterinary , Animals , Cat Diseases/pathology , Cat Diseases/surgery , Cats , Endometrium/pathology , Female , Mucous Membrane/pathology , Uterine Prolapse/diagnosis , Uterine Prolapse/pathology , Uterine Prolapse/surgery , Uterus/pathology , Uterus/surgery
3.
Reprod Domest Anim ; 49(2): 202-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24237178

ABSTRACT

Contrast-enhanced ultrasound with sulphur hexafluoride microbubbles was performed in seven healthy dogs without a history of reproductive pathology and with histologically confirmed normal testes and in 42 dogs with chronic scrotal anomalies. All dogs underwent orchiectomy and histological examination. Enhancement patterns and perfusion parameters (peak intensity and regional blood flow) of testes of healthy dogs and testes with chronic lesions were compared. Fourteen non-pathologic and 60 pathologic testes were considered. Forty testes were neoplastic (24 interstitial cell tumours, 9 seminomas, 7 Sertoli cell tumours), 20 were non-neoplastic (16 testicular degenerations, 2 chronic orchitis, 1 testicular atrophy, 1 interstitial cell hyperplasia). In healthy dogs, the contrast medium flow had a rapid homogeneous wash-in and wash-out, with a short peak phase. With contrast ultrasound, testes that were inhomogeneous with a hyperenhancing pattern were associated with neoplasia (sensitivity: 87.5%, specificity: 100%). Lesions with persistent inner vessels and a hypo-to-isoechoic background were significantly associated with seminomas (sensitivity: 77.8%, specificity: 100%). Testes with non-neoplastic lesions were characterized by a scant/moderate homogeneous enhancement. Perfusion parameters were higher in neoplastic lesions. Contrast ultrasound was a feasible diagnostic tool in the assessment of testicular lesions, with hyperenhancement being an important feature in the diagnosis of malignancy.


Subject(s)
Contrast Media/pharmacology , Dog Diseases/pathology , Testicular Diseases/veterinary , Testis/diagnostic imaging , Ultrasonography/veterinary , Animals , Dog Diseases/diagnostic imaging , Dogs , Male , Testicular Diseases/diagnostic imaging , Testicular Diseases/pathology , Testis/pathology , Ultrasonography/methods
4.
Tissue Cell ; 43(1): 1-7, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21094964

ABSTRACT

The female reproductive system of the tsetse fly Glossina morsitans morsitans is analysed by scanning electron microscopy (SEM). The study focuses in particular on the choriothete, a peculiar uterine structure involved in the viviparous mode of reproduction of Glossina morsitans morsitans. Under light microscopy, the choriothete appears formed by numerous tongue-like folds projecting towards the uterine lumen and lined by a thin cuticle. SEM analysis highlights for the first time a distinctive new feature that is not visible by traditional histological methods. That is a cuticular covering of the choriothete, which shows numerous thorns in the form of crest-like structures arranged in nearly parallel lines. The role of the choriothete in pregnancy and in larval nourishment is discussed.


Subject(s)
Genitalia, Female/ultrastructure , Tsetse Flies/ultrastructure , Viviparity, Nonmammalian/physiology , Animals , Female , Genitalia, Female/cytology , Larva/cytology , Larva/ultrastructure , Tsetse Flies/cytology
5.
Vet Res Commun ; 34 Suppl 1: S41-5, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20458536

ABSTRACT

Standardbred maiden mares are generally stressed and in poor physical condition because of their incorrect management at the end of their racing careers. The purpose of this study was to identify an objective assessment that, similar to body condition score (BCS) determination, is easy to measure and able to confirm or improve fattening status assessment, as well as to ascertain whether a relationship with reproduction efficiency exists in subjects destined for a first-time insemination program. The authors assessed 29 Standardbred maiden mares (7 +/- 2 years old) during the breeding season. On January 15 (day 0), the same operator performed the following on all subjects: the first gynecological and ultrasound examination, a BCS assessment (range 0 to 5), and an adiposity objective assessment (i.e., measurement of fat thickness by ultrasound scan). At day 0, all mares were in seasonal anestrous. On ovulation day, all subjects exited the study. Both techniques were shown to be significantly and reciprocally correlated (r = 0.976; P < 0.01) to the first seasonal ovulation in maiden mares (-0.772 and -0.805, respectively, for fat thickness and BCS; P < 0.01). Based on the results obtained, regression equations for the prediction of days to the first seasonal ovulation (y) were created. The best predictive equation was the following: y = 26.714x(3) - 202.44x(2) + 446.04x - 195.65 (R(2) = 0.783; SE = 17 d; P0.01), with an independent BCS variable. In conclusion, this study suggests that increasing the plane of nutrition (i.e., flushing), starting approximately 3 weeks before the breeding season, stimulates ovarian activity in stressed maiden mares.


Subject(s)
Adipose Tissue/physiology , Body Composition/physiology , Estrous Cycle/physiology , Horses/physiology , Animals , Body Constitution/physiology , Female , Ovulation/physiology
6.
Tissue Cell ; 40(4): 231-42, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18272191

ABSTRACT

Scaphoideus titanus is the insect vector of flavescence dorée (FD), a yellow disease of grapevines. Observations on adult females and nymphs of S. titanus showed that this insect is associated with a complex microbial community. Ultrastructural analysis showed that the fat body, salivary glands and ovary of the insect harbour microorganisms showing the brush-like structure typically observed in the genus Cardinium. In particular, it has been shown that these symbiotic bacteria are present both in the follicular cells and in the eggs. In addition, cells resembling bacteriocytes, harbouring numerous Cardinium symbionts in the cytoplasm, were observed in the apical portion of the ovary in adult females. These cells are likely responsible for bacterial transmission to the ovary. Optical microscopy showed that the fat body harbours an enormous population of yeast-like symbionts (YLSs). Ultrastructural observations showed that these symbionts are enclosed within specialized cells of the fat body and are also present in the ovary, where they are found in both the follicular cells and the eggs. There is thus evidence that both Cardinium and the YLSs are transovarially transmitted to the offspring. To our knowledge, S. titanus is the sole insect known to transmit two different kinds of symbionts to the eggs, a prokaryote and an eukaryote. Gene sequence analysis and in situ hybridization led to the identification of YLSs as members of the class Sordariomycetes (=Pyrenomycetes). Finally, ultrastructural observation of the midgut content revealed the presence, in both adult females and nymphs, of a complex microbial community, which include a phytoplasma-like microorganism, likely the agent of FD.


Subject(s)
Bacterial Physiological Phenomena , Hemiptera/microbiology , Ovary/microbiology , Symbiosis , Yeasts/physiology , Animals , Bacteroidetes/ultrastructure , Digestive System/microbiology , Digestive System/ultrastructure , Embryo, Nonmammalian/ultrastructure , Fat Body/microbiology , Fat Body/ultrastructure , Female , Hemiptera/ultrastructure , In Situ Hybridization , Ovary/ultrastructure , Polymerase Chain Reaction , Yeasts/ultrastructure
7.
Tissue Cell ; 38(4): 257-61, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16876837

ABSTRACT

An ultrastructural study of the novel symbiont Cardinium sp. was performed with particular attention to the description of the structure and organization of highly elaborated cytoplasmic complexes containing microtubule-like elements (MLC). Three major components were observed. The first was a system of microtubule-like elements (ML) arranged in parallel array extending from the plasma membrane into the cytosol of the bacterium. The second, an fibrous electrondense plaque (FEP), approximately 8 nm thick, located 7.5 nm away from the plasma membrane and parallel to it. The third component, not previously reported, was described for the first time in this paper. This consisted of a set of regularly distributed 8 nm electron-dense structures (ES), with a center-to-center spacing of about 12 nm, adhering to the outer leaflet of the plasma membrane. Often, the ES created a close connection between the plasma membrane and the outer membrane, so that in this area they became straight and stiff. The first and second component of these structures are compared to previously described microtubules and microfilaments.


Subject(s)
Bacteria/ultrastructure , Cytoplasmic Structures/ultrastructure , Hemiptera/microbiology , Symbiosis/physiology , Animals , Cytoplasmic Structures/physiology
8.
Reprod Domest Anim ; 39(3): 136-40, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15182288

ABSTRACT

Cystic endometrial hyperplasia-pyometra complex is the most frequent and important endometrial disorder encountered in bitches. The pathogenesis of the disease is related to the activity of progesterone [Feldman and Nelson, Canine and Feline Endocrinology and Reproduction (1996) W.B. Saunders, Philadelphia]. Cystic endometrial hyperplasia (CEH) is an abnormal response of the bitch's uterus to ovarian hormones [De Bosschere et al. Theriogenology (2001) 55, 1509]. CEH is considered by many authors to be an exaggerated response of the uterus to chronic progestational stimulation during the luteal phase of the oestrous cycle, causing an abnormal accumulation of fluid within the endometrial glands and uterine lumen (De Bosschere et al. 2001). The resulting lesions of pyometra are due to the interaction between bacteria and hormones. The aim of this study was to evaluate if transabdominal uterine ultrasonography can be a useful and reliable diagnostic method to confirm Dow's [Veterinary Record (1958) 70, 1102] and De Bosschere's histopathological classification of CEH-pyometra complex. The study was carried out on 45 bitches with pyometra, 10 purebreds and 35 crossbreeds, 1-15 years old, 20% of which had whelped at least once. None of these animals had received exogenous oestrogen or progesterone treatment. On admission the 45 animals were in the luteal phase of the oestrus cycle. Clinical signs, blood parameters, uterine ultrasonography, bacterial swabs and uterine histopathological results were recorded. Results suggest that ultrasonographic examination is a useful and reliable tool for the diagnosis of cystic endometrial hyperplasia.


Subject(s)
Dog Diseases/diagnostic imaging , Endometrial Hyperplasia/veterinary , Endometritis/veterinary , Animals , Cysts/diagnostic imaging , Cysts/veterinary , Dog Diseases/microbiology , Dogs , Endometrial Hyperplasia/diagnostic imaging , Endometritis/diagnostic imaging , Female , Pedigree , Predictive Value of Tests , Ultrasonography/veterinary
9.
Tissue Cell ; 36(1): 43-53, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14729452

ABSTRACT

We have recently performed molecular characterisation of an intracellular alpha-proteobacterium, named IricES1, which resides in the ovarian tissue of female Ixodes ricinus ticks from Italy. A unique characteristic of this bacterium is its ability to invade the mitochondria of the cells in which it resides. Although some ultrastructural studies have been performed on close relatives of this bacterium from I. ricinus in England and Switzerland, a number of questions remain about its movement within ovarian tissues and mitochondria. We have performed the first detailed ultrastructural examination of IricES1 in engorged female adult I. ricinus. Among our findings was that the bacterium enters mitochondria in a similar way to that employed by the 'predatory' bacterium Bdellovibro bacteriovorus, that is, between the inner and outer membranes. It then appears to multiply, with the new 'colony' consuming the mitochondrial matrix. Despite having many of their mitochondria consumed, oocytes appear to develop normally, and the bacteria are likely to be vertically transferred to all eggs.


Subject(s)
Bdellovibrio/physiology , Ixodes/microbiology , Mitochondria/microbiology , Symbiosis , Animals , Bdellovibrio/growth & development , Female , Ixodes/cytology , Microscopy, Electron , Mitochondria/ultrastructure , Oocytes/microbiology , Oocytes/ultrastructure , Ovary/cytology , Ovary/microbiology
10.
Placenta ; 22(8-9): 735-41, 2001.
Article in English | MEDLINE | ID: mdl-11597194

ABSTRACT

The H beta 58 gene, whose disruption in mice causes reabsorption of the embryo at 9.5 days post-conception, is believed to be essential for development of the placenta. Although the H beta 58 gene is well conserved in some Amniota, nothing is known about its presence in reptiles, some species of which have developed a chorioallantoic placenta. In this work, we investigated the expression of H beta 58 mRNA and protein in the three-toed skink, Chalcides chalcides. H beta 58 protein expression was found in the uterine epithelium beginning from the peri-ovulatory stage. However, it increased strongly at the moment of placental formation, when a high level of expression of mRNA and protein was also observed in the extra-embryonic membranes. The expression of H beta 58 mRNA and protein was maintained, although to a lesser degree, in the placenta during late pregnancy. It was also present in the early embryo. Finally, cloning and sequencing of a gene fragment revealed strong homology of the reptile gene with that of mammals. The high degree of conservation of the gene in amniote vertebrates and its presence in a viviparous squamate reptile (as in mammals) indicates an important role of this gene in the chorioallantoic placenta formation and development.


Subject(s)
Carrier Proteins/genetics , Placenta/physiology , Reptiles/genetics , Reptilian Proteins/genetics , Vesicular Transport Proteins , Allantois/chemistry , Animals , Base Sequence , Carrier Proteins/analysis , Chorion/chemistry , Cloning, Molecular , Epithelium/chemistry , Female , Gene Expression , Molecular Sequence Data , Ovulation , Pregnancy , RNA, Messenger/analysis , Rats , Reptilian Proteins/analysis , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology , Uterus/chemistry
11.
Microbes Infect ; 3(5): 373-9, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11369274

ABSTRACT

Microsporidia are amitochondrial eukaryotic obligate intracellular parasites. They are reported to infect every animal group from protists to vertebrates, including humans. Microsporidia are of interest as opportunistic pathogens in humans and for certain characteristics which raise questions about their evolution and phylogenetic position. This review describes the basic biology and invasion mechanisms of microsporidian species infecting humans.


Subject(s)
Microsporidia/cytology , Microsporidia/physiology , Microsporidia/pathogenicity , Opportunistic Infections/parasitology , Animals , Eukaryotic Cells , Evolution, Molecular , Genes, Protozoan , Life Cycle Stages , Microsporidia/growth & development , Microsporidiosis/parasitology , Phylogeny
12.
Vet Rec ; 147(10): 267-70, 2000 Sep 02.
Article in English | MEDLINE | ID: mdl-11030228

ABSTRACT

Two operators attempted to detect pregnancy ultrasonographically in 196 sows daily from 15 to 25 days after insemination; 20 unbred sows were also investigated. The probe was applied transcutaneously on the right abdominal wall near the last three mammary glands. During each examination, the embryos were visualised and their transverse and longitudinal dimensions were measured. Pregnancy was confirmed by an ultrasonographic detection of embryos five days after the first ultrasound diagnosis and finally 30 to 32 days after insemination. The accuracy of diagnosis was less than 83 per cent on days 15, 16 and 17 but improved to more than 90 per cent from day 18 onwards. The uterine echotexture was studied in seven sows at oestrus and 15, 17, 19, 21, 23 and 25 days after insemination. The echotexture was more homogeneous from days 15 to 25 after insemination than at oestrus.


Subject(s)
Pregnancy Tests/veterinary , Swine , Ultrasonography, Prenatal/veterinary , Abdomen/diagnostic imaging , Animals , Embryonic and Fetal Development , Female , Pregnancy , Sensitivity and Specificity
13.
Antimicrob Agents Chemother ; 44(11): 3012-6, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11036015

ABSTRACT

Since 1985 microsporidia have been recognized as a cause of emerging infections in humans, mainly in immunocompromised human immunodeficiency virus-positive subjects. As chitin is a basic component of the microsporidian infective stage, the spore, we evaluated in vitro the susceptibility of a human-derived strain of Encephalitozoon hellem to nikkomycin Z, a peptide-nucleoside antibiotic known as a competitive inhibitor of chitin synthase enzymes. Transmission electron microscopy showed that this drug, at 25 microgram/ml, reduced the number of parasitic foci by about 35% +/- standard deviation after 7 days of culture (P < 0.0001) and induced cell damage of both mature and immature spores and also other sporogonic and merogonic stages. In particular, an irregular outline of the cell shape and an abnormally condensed cytoplasm in meronts and sporonts were documented. Also, the polar tubule and the polaroplast membranes appeared disarrayed in the sporoblast stage. The spore wall showed an enlarged endospore and delaminated exospore. Mature spores had a complete cytoplasmic disorganization and a swollen and delaminated cell wall. No ultrastructural cell damage was observed in uninfected control cultures treated with the drug.


Subject(s)
Aminoglycosides , Anti-Bacterial Agents/pharmacology , Antiprotozoal Agents/pharmacology , Encephalitozoon/drug effects , Analysis of Variance , Animals , Encephalitozoon/ultrastructure , Humans , Parasitic Sensitivity Tests
14.
J Eukaryot Microbiol ; 46(4): 410-5, 1999.
Article in English | MEDLINE | ID: mdl-10532801

ABSTRACT

Using transmission electron microscopy, immuno-electron microscopy, and biochemical techniques such as 2-D electrophoresis and immunoblotting, actin was found in all biological stages of the microsporidia Encephalitozoon hellem and Encephalitozoon cuniculi.


Subject(s)
Actins/analysis , Cytoskeleton/chemistry , Encephalitozoon cuniculi/ultrastructure , Encephalitozoon/ultrastructure , Animals , Cytoskeleton/ultrastructure , Electrophoresis, Gel, Two-Dimensional , Encephalitozoon/chemistry , Encephalitozoon/growth & development , Encephalitozoon cuniculi/chemistry , Encephalitozoon cuniculi/growth & development , Immunoblotting , Immunohistochemistry , Microscopy, Electron , Microscopy, Fluorescence , Microscopy, Immunoelectron
15.
Radiol Med ; 98(5): 391-4, 1999 Nov.
Article in Italian | MEDLINE | ID: mdl-10780221

ABSTRACT

INTRODUCTION: Prostatic abscesses are an uncommon finding in the dog; they are most frequently seen in dogs over six years old, often in association with benign hyperplasia. Ultrasonography (US) is an essential technique to study prostatic conditions in the dog, because the particular anatomical site of this gland in the dog makes rectal palpation insufficient to assess even macroscopic changes. Presently, US-guided drainage makes a particularly efficient tool for treatment of this condition in these patients. We report on our personal technique of percutaneous drainage of prostatic abscesses in the dog. MATERIAL AND METHODS: Forty-five dogs of different breeds and age were examined. Some of them were given short anesthesia or mild sedation for restraining purposes, although this procedure is painless and could be performed under local anesthesia like in human patients. In man, the approach is perineal, but in the dog it is best to use an abdominal approach with right or left inguinal positions. US is necessary for correct drainage of the abscess and for monitoring throughout the procedure. DISCUSSION AND CONCLUSION: US-guided percutaneous drainage of prostatic abscesses in the dog proved to be a safe and quick tool providing excellent results. No patients exhibited any postoperative complication and we had as little as 10% relapses at 30 days. The following drainage with alcoholization of the abscessual cavity resolved the conditions definitively. This technique was particularly interesting for both its success rate and the lack of postoperative complications, which are usually quite common after conventional surgery.


Subject(s)
Abscess/therapy , Abscess/veterinary , Dog Diseases/therapy , Prostatic Diseases/therapy , Prostatic Diseases/veterinary , Abscess/diagnostic imaging , Animals , Dog Diseases/diagnostic imaging , Dogs , Male , Prostate/diagnostic imaging , Prostatic Diseases/diagnostic imaging , Retrospective Studies , Suction/methods , Suction/statistics & numerical data , Suction/veterinary , Ultrasonography, Interventional/statistics & numerical data , Ultrasonography, Interventional/veterinary
16.
J Eukaryot Microbiol ; 45(3): 347-51, 1998.
Article in English | MEDLINE | ID: mdl-9627995

ABSTRACT

The mitotic process in microsporidian Encephalitozoon hellem, a known human pathogen, has been studied with the aim of elucidating some ultrastructural aspects of its nuclear division. The presence of a nuclear spindle, of "electrondense spindle plaques" associated with the nuclear envelope and of cytoplasmic double walled vesicles are reported. We suggest that these "electrondense spindle plaques" serve as foci for intranuclear and cytoplasmic microtubule arrangements, similar to the microtubule organizing centers within the centrosomes of animal cells. The extent to which the microsporidial division process is comparable with that of more familiar eukaryotes such as yeast cells is discussed.


Subject(s)
AIDS-Related Opportunistic Infections/parasitology , Encephalitozoon/ultrastructure , Encephalitozoonosis/parasitology , Mitosis , Animals , Encephalitozoon/growth & development , Humans , Microscopy, Electron , Microtubules/ultrastructure , Nuclear Envelope/ultrastructure , Spindle Apparatus/ultrastructure
17.
Parassitologia ; 40(3): 309-16, 1998 Sep.
Article in English | MEDLINE | ID: mdl-10376288

ABSTRACT

All examined species of cockroaches have been shown to harbour intracellular bacteria in specialized cells (bacteriocytes) of the fat body. In termites, bacteria in specialized cells have been observed only in Mastotermes darwiniensis (Isoptera: Mastotermitidae). All of these bacteria have been assigned to the same eubacterial lineage, with the bacteria of M. darwiniensis as the sister group to the cockroach bacteria. While the main steps of the life cycle of cockroach bacteria have been described, little is known about the bacteria of M. darwiniensis. More specifically, no data are available on their behaviour during the development of this termite. Using both optical and electron microscopy methods, we examined embryos of M. darwiniensis at different developmental stages. Our results show that the integration of bacteria during the development of M. darwiniensis is implemented in the same way as in cockroaches. In particular, we observed the aggregation of a large amount of bacteria in a single mass in the yolk sac, with vitellophage-associated bacterial lysis. In cockroaches, a similar process has been described in detail for Periplaneta americana (Blattaria: Blattidae), where the bacterial mass is referred to as the transitory mycetome. The formation of a transitory mycetome could thus be regarded as an ancestral condition for cockroaches and termites.


Subject(s)
Bacteria/isolation & purification , Isoptera/embryology , Isoptera/microbiology , Symbiosis , Animals , Bacteria/ultrastructure , Cockroaches/embryology , Cockroaches/microbiology , Cockroaches/ultrastructure , Isoptera/ultrastructure , Microscopy, Electron
18.
J Eukaryot Microbiol ; 44(6): 80S, 1997.
Article in English | MEDLINE | ID: mdl-9508461

ABSTRACT

Ultrastructural studies were carried out to describe the nuclear division cycle of a strain of Encephalitozoon hellem isolated from an Italian AIDS patient. The nuclear division occurs during the proliferative vegetative phase and it is characterized by the intranuclear mitosis and by the lack of centrioles. The spindle termini are electron dense spindle plaques (ESPs), resembling to the spindle pole bodies (SPBs) of Saccharomycetes. The ESPs are bifacial organella forming microtubules on both nucleoplasic and cytoplasmic faces. In the outer layer of the spindle plaque are present vesicular elements lined by a double membrane of unknown function. The peculiar morphological features of E. hellem ESPs indicate that both intranuclear spindle and cytoplasmic microtubules are involved in the nuclear division.


Subject(s)
Encephalitozoon/ultrastructure , Microtubules/ultrastructure , Spindle Apparatus/ultrastructure , AIDS-Related Opportunistic Infections/parasitology , Animals , Cell Division , Cell Nucleus/ultrastructure , Encephalitozoon/cytology , Encephalitozoonosis/parasitology , Humans , Mitosis
19.
Tissue Cell ; 29(6): 651-64, 1997 Dec.
Article in English | MEDLINE | ID: mdl-18627832

ABSTRACT

Mature spermatozoa belonging to four salamander species, Salamandrina terdigitata, Triturus alpestris, Triturus carnifex and Triturus vulgaris, have been investigated by electron microscopy. The sperm ultrastructure of these species was compared with that of previously examined urodeles (36 species and 20 genera) and with that of anurans and caecilians. Many phylogenetic considerations may be inferred as a consequence of comparative spermatology. Urodela appears to be a monophyletic order characterized by three sperm synapomorphies: the acrosomal barb, nuclear ridge and marginal filament. Cryptobranchoidea are confirmed to form a monophyletic suborder having two synapomorphic characters: absence of mitochondria in the tail, and cylindrical shape of the tail axial rod. Within the family Salamandridae, sperm morphology confirms the phylogenetic distance between Salamandrina and Triturus, as already pointed out on the basis of molecular and morphological characters. The very complex ultrastructure of spermatozoa confirms a previous opinion that internal fertilization is the ancestral condition of the Amphibia.

20.
J Eukaryot Microbiol ; 43(3): 181-6, 1996.
Article in English | MEDLINE | ID: mdl-8640188

ABSTRACT

A study of the spore wall of Encephalitozoon hellem was performed on thin sections, freeze-fracture, and deep-etched samples to obtain information on spore wall organization and composition. Our observations demonstrate that the spore wall is formed by an inner 30-35 nm electron-lucent endospore and an outer 25-30 nm electron-dense exospore. The exospore is a complex of three layers: an outer spiny layer, an electron-lucent intermediate lamina and an inner fibrous layer. Freeze-fracture and deep-etching techniques reveal that the intermediate lamina and the inner fibrous layer result from the different spatial disposition of the same 4-nm thick fibrils. In thin sections the endospore reveals a scattered electron-dense material that appears in the form of trabecular structures when analyzed in deep-etched samples. The presence of chitin in the exospore is discussed.


Subject(s)
Encephalitozoon/ultrastructure , Animals , Cell Wall/ultrastructure , Cells, Cultured , Humans , Spores/ultrastructure
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