[Syphilitic osteitis in an HIV-negative patient]

BACKGROUND

Secondary syphilis with skeletal involvement is rare; herein we report a case concerning an HIV-negative patient.

PATIENTS AND METHODS

During the course of secondary syphilis, a 28-year-old male homosexual, HIV-negative and with no medical history, presented intense and localized headaches persisting despite three weeks of antibiotic therapy. Bone scintigraphy revealed three bone lesions evocative of syphilitic osteitis, for which prolonged antibiotic therapy was instituted.

DISCUSSION

Few cases of syphilitic osteitis have been described in the recent literature and these are linked to haematogenous diffusion of Treponema pallidum. Skeletal disease is suggested when febrile bone pain is present. Bone scintigraphy remains the best diagnostic tool and treatment comprises prolonged penicillin G or ceftriaxone.

[Bullous mastocytosis in infancy: a rare presentation]

Mastocytosis is a rare condition related to an abnormal proliferation of mast cells and their accumulation in tissues. Cutaneous mastocytosis is the most common form and mainly affects newborns and infants. The symptoms are caused by the release of mediators contained in mast cells, including histamine. Mastocytosis may be associated with a mutation in the gene encoding the c-kit receptor. Clinically, there are different dermatological findings, which combine acute cutaneous, digestive, or even hemodynamic manifestations in varying degrees. The diagnosis is confirmed by the histological study of a skin sample. We report here the case of a 4-month-old infant suffering from diffuse cutaneous bullous mastocytosis, a very rare variety of mastocytosis. This infant had an erosive and bullous manifestation of dermatosis, initially confused with impetigo. The proliferation of bullous lesions led to her hospitalization. Codeine intake for pain was responsible for a large and extensive bullous reaction associated with anaphylactic shock. This context of bullous spread occurring after taking codeine led to the suspicion of bullous diffuse cutaneous mastocytosis, a diagnosis that was confirmed histologically. This observation demonstrates the difficulty of mastocytosis diagnosis, mostly due to its rarity, especially in its diffuse bullous forms. The rapid deterioration of this patient, after the codeine prescription, emphasizes the importance of the eviction of histamine-releaser compounds in the management of this disease.

[Extensive purpura and septic schock in two patients with Capnocytophaga canimorsus]

INTRODUCTION

Capnocytophaga canimorsus is a Gram negative bacillus present in oral flora and in saliva of dogs and cats. It can be responsible for septicaemia and meningitides in some patients after dog or cat bite two patient with a septic shock due to C. canimorsus, who presented with an extensive pupura are reported.

CASE REPORT

A 50 year-old man with a past history of splenectomy was referred to an emergency department for a shock with vomiting, abdominal pain and generalized ecchymotic purpura culture samples isolated C. canimorsus in peritoneal fluid. Purpura occurred secondary to a disseminated intravascular coagulation. Despite intensive care and major antibiotherapy, the patient rapidly died. Four days previously, the patient administered pills in his dog mouth. The second patient was a 39 year old alcoholic man who was hospitalised for vomiting and septic shock witch occurred 24 hours after a dog bite. He presented with a livido and a diffuse purpura associated with necrotic lesions. Cultures of blood samples isolated C. canimorsus.

CONCLUSION

These severe infections due to C. canimorsus should be avoided by the routine use of early antibiotherapy with amoxicilline and clavulanic acid in patients with dog or cat bite, particularly if patient with associated debilitating disorders.

Méningococcémie chronique

INTRODUCTION

Chronic meningococcemia is a rare clinical form of invasive Neisseria meningitidis infection. We report 2 cases.

OBSERVATIONS

A 39 year-old man and a 42 year-old woman had developed a widespread, fleeting and painful maculopapular cutaneous eruption over the past few weeks, associated with intermittent fever and inflammatory arthralgia. In both cases blood cultures isolated a serogroup B meningococcus that confirmed the diagnosis. Cutaneous histology revealed a non-specific image of leukocytoclastic vasculitis. Treatment with beta lactamin antibiotics was successful after respectively 3 weeks and 12 days.

DISCUSSION

This septicemia is characterized by the clinical triad of cutaneous eruption, fever and arthralgia. It must not be mistaken for connectivitis because inappropriate corticosteroid prescription may provoke severe complications. Confirmation of the diagnosis is provided by the blood cultures, which should be repeated. In the case of strong clinical suspicion, the rapid improvement with antibiotics confirms the diagnosis.

Formation of a large Vasa-positive germ granule and its inheritance by germ cells in the enigmatic Chaetognaths

Chaetognaths (arrow worms) are abundant hermaphrodite marine organisms whose phylogenetic position amongst protostomes and deuterostomes is still debated. Ancient histological observations dating from a century ago described the presence in eggs of a large granule, presumed to be a germ plasm, and its probable inheritance in four primary germ cells (PGCs). Using videomicroscopy, electron microscopy and immunocytochemistry (labelling with anti-Vasa antibodies) we have followed the cycle of aggregation and dispersion of germ plasm and nuage material in eggs, embryos, PGCs and oocytes in several species of benthic (Spadella) and planctonic (Sagitta) chaetognaths. In these animals, germ cells and gametes can be observed in vivo throughout the 1-2 month life cycle.

After describing internal fertilization in live animals we show that the single large (15 μm diameter) germ granule forms by a spiralling aggregation movement of small germ islands situated in the vegetal cortex at the time of first mitosis. We also demonstrate that the granule forms autonomously in unfertilized activated eggs or fertilized egg fragments. Once formed, the germ granule first associates with the cleavage furrow and is segregated into one of the first two blastomeres. The germ granule is then translocated from the cortex to the mitotic spindle during 3rd cleavage and remains in the single most-vegetal blastomere until the 32-cell stage. At the 64-cell stage the germ granule is partitioned as nuage material into two founder PGCs and further partitioned into four PGCs situated at the tip of the archenteron during gastrulation. These four PGCs migrate without dividing to reach the transverse septum, then proliferate and differentiate into oocytes and spermatocytes of two ovaries and two testes. We noted that germ plasm and nuage material were associated with mitochondria, the nucleus, the spindle and the centrosome during some stages of development and differentiation of the germ line. Finally, we demonstrate that a Vasa-like protein is present in the germ granule, in PGCs and in the electron-dense material associated with the germinal vesicle of oocytes. These features stress the conservation of cellular and molecular mechanisms involved in germ cell determination.

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Origin of germ cells, sex determination, and sex inversion in medusae of the genus Clytia (Hydrozoa, leptomedusae): the influence of temperature

In Cnidaria, a separation between soma and germline remains unclear. In this work, we studied the origin of germinal cells and determination of the sexual phenotype in Clytia hemisphaerica and Clytia sp. Colonies of C. Hemisphaerica were cultivated and the medusae liberated by each colony raised until maturity. Two hermaphrodite colonies were obtained, liberating male and female medusae. These two colonies and their medusae were raised at 15 degrees C, 21 degrees C, or 24 degrees C. The medusae budded and cultured at 24 degrees C were mainly female (80%). In contrast, if the medusae were released at 15 degrees C, at whatever temperature they were raised later, they were mainly male (85%). The same occurred if, after release at 24 degrees C but before the formation of the gametes, they were kept at 15 degrees C for at least 24 hr. We suggest that there are two subpopulations of germ cells. The female line will be dominant at 24 degrees C but temperature sensitive, with inhibition of this line by a temperature drop to 15 degrees C, this inverting the population sex-ratio. The irreversible action of a temperature drop to 15 degrees C supports the view that the germ cells are isolated very early. In C. hemisphaerica, hermaphrodite medusae were never observed. On the contrary, in Clytia sp., probably a new species, we have found male, female, but also hermaphrodite specimens. This is the second definite example of hermaphroditism described in any hydromedusan. The transformation of female into hermaphrodite then into male specimens occurs at 13 degrees C. These results demonstrate the unstable character of genetic sex determination in cnidarians, at least in certain species.

Characteristics of pronuclear migration in Beroe ovata

In the large eggs (approximately 1 mm) of the ctenophore Beroe ovata, female pronuclei migrate long distances to join stationary male pronuclei in the peripheral cytoplasm that surrounds the yolky interior. We have investigated the mechanism of nuclear migration using time lapse video recording, automated image analysis, visualization of microtubules by immunofluorescence and rhodamine-tubulin injection, and electron microscopy. Female pronuclei migrated at average speeds of 0.2 microns/sec, and were found to show periodic oscillations in velocity. Alternating phases of acceleration and deceleration occurred with an average periodicity of 235 seconds covering distances of 47 microns (about 3 times the nuclear diameter). Migration velocities and velocity oscillations were similar in fertilized and unfertilized eggs; however, changes in migration direction were much more frequent in unfertilized eggs. Characteristic deformations of the pronuclear membrane and occasional rotation of the nuclear contents were observed during migration. Inhibitor studies indicated that microtubules are required for nuclear migration. In fertilized eggs the top of the nucleus was found to move through the dense layer of aligned sperm aster microtubules. The frequent changes in direction of pronuclear migration in unfertilized eggs reflect the random organization of the microtubule layer in the absence of sperm derived centrosomes. Densely packed endoplasmic reticulum was found intermeshed with sperm aster microtubules and connected extensively with the nuclear membrane during migration. Most nuclear pores were grouped in an infolding of the nuclear membrane. We suggest that in fertilized eggs the female pronucleus is transported to the minus ends of sperm aster microtubules using motor molecules attached either to the outer nuclear membrane and/or to the network of connecting ER.

Ctenella aurantia, genre et espèce nouveaux de cténophore tentaculé (Ctenellidae fam.nov.) méditerranéen sans colloblastes et avec ventouses labiales

Ctenella aurantia gen. et sp.nov. is a small Mediterranean tentacled ctenophore. Its ovoid and flattened body is opaque and yellow-orange, with red-pigmented areas. Comb rows are arranged in pairs from the apex to the oral third of the body. The tentacular sheaths situated at the end of the oral third of the body open medially; they terminate in an aboral open groove which can close up around the unramified tentacles. The gastrovascular system is simple and follows the axis of the body; it has no peripheral canals but two long apical canals project into the aboral zone. The mouth forms a sagittal slit bordered by two thick lips, each bearing a sucker on its internal wall. The species also possesses very distinctive cytological features, notably the absence of colloblasts on the tentacles and the consistent presence of exogenic cnidocysts that are embedded in the gastrovascular wall. The muscular cells of the oral zone have no sarcomeres, but have both fine and thick myofilaments that are arranged alternately. The species is very distinctive, both in its cytological characteristics and its general organization. It is tentatively classified in the order Cydippida, and its relationship to some other species is mentioned.

Biologie et étude ultrastructurale des spermatozoïdes du cnidaire Clytia hemispherica (Leptomedusae): mise en évidence d'un processus acrosomal

Mature sperm of Clytia hemispherica were studied by electron microscopy in the gonads, at their exit from the gonads, and at fertilization. The presence of an acrosomal complex at their anterior pole, which has long been a subject of controversy in cnidarians, was demonstrated. A chemoattractant and an inductor of the acrosomal reaction, both released at the animal pole of the eggs, were responsible for the accumulation of spermatozoons and the formation of the acrosomal process. A striated rootlet extending from the pericentriolar region to the plasma membrane was described, and its possible relationship to positive chemotaxis discussed. Ultrastructural modifications of the testes induced by light, a factor controlling spermiation, were investigated.

In vitro fertilization in ctenophores: sperm entry, mitosis, and the establishment of bilateral symmetry in Beroe ovata

We have found ways to control in vitro fertilization in a ctenophore (Beroe ovata) for the first time. This is based on the existence of a partial block to self-fertilization at the time of gamete release which can be overcome by removal of the egg envelope. It has allowed us to exploit the excellent optical properties of Beroe eggs to make detailed observations on all events from sperm penetration or penetrations in these physiologically polyspermic eggs to first cleavage, and to extend our initial observations (Carré and Sardet, 1984). Sperm entry is characterized by local modifications of the egg cortex in a 70-microns zone around the penetration site or sites. Upon sperm entry, the egg surface contracts and relaxes locally, then a fertilization cone forms and disappears. These events are accompanied by localized exocytosis, growth of a ring of microvilli, thickening of the egg cortex, and gathering of mitochondria around the sperm pronuclei. The female pronucleus then migrates beneath the egg surface toward one or successive sperm pronuclei. The fusion of pronuclei, sperm and egg chromatin intermixing, and mitosis were also observed with exceptional clarity. Furthermore, we have noticed that the direction of the last trajectory of the female pronucleus tends to define the orientation of the mitotic spindle, and as a consequence the position of first unipolar cleavage furrow. This in turn determines the future sagittal plane of the embryo and of the adult B. ovata.

Acquisition de cnidocystes et différenciation de pseudocolloblastes chez les larves et les adultes de deux cténophores du genre Haeckelia Carus, 1863

The development of two species of cydippid Ctenophora, Haeckelia rubra and Haeckelia bimaculata, was studied to determine the origin and acquisition of exogenous cnidocysts in these two species, which lack colloblasts. A new type of cell, the pseudocolloblasts, is described. In H. rubra, the outer layer of the egg contains cnidocysts which are ingested by the larva after gastrulation; these cnidocysts make up the initial stock of exogenous cnidocysts that will allow the ctenophore to catch its first Cnidaria. In H. bimaculata, the outer layer of the egg is devoid of cnidocysts. The hatching larva has no cnidocysts either, but its tentacles are lined by an hitherto unknown type of glandular cell that we have named the pseudocolloblast. Pseudocolloblasts are composed of a secretory head bearing regularly interspaced, striated structures and an anchoring stalk. They eject their content progressively during successive phases of exocytosis. Pseudocolloblasts differ morphologically from real colloblasts, but they probably have the same function and they allow larvae of H. bimaculata to catch cnidarian larvae and thus acquire the exogenous cnidocysts present in postlarval and adult stages. Cnidocysts are identical in both species of Haeckelia in the Mediterranean Sea, consisting of macroisorhizas and microisorhizas in which the intracapsular filament has five circumferential pleats, a character typical of Narcomedusae. They differ in size from the cnidocysts found in H. rubra in the Pacific and in the Sea of Japan.[Journal translation]

Fertilization and early development in Beroe ovata

Fertilization in the clear egg (1 mm in diameter) of the ctenophore Beroe ovata and, in particular, the positioning and movements of pronuclei, and their relationship to the larval oral-aboral axis have been observed. Fertilization can take place anywhere on the egg surface. The sperm pronucleus remains at its entry site and becomes surrounded by a specialized zone (30-50 micron in diameter) beneath the surface referred to as the sperm pronuclear zone or SPZ and devoid of large cortical granules. Polyspermy has been observed to be frequent; each pronucleus is surrounded by its own SPZ. Only the egg pronucleus migrates with a continuous velocity (averaging 18 micron/min) and moves beneath the surface directly toward the immobile sperm pronucleus. In polyspermic eggs, the egg pronucleus can probe several SPZ, each containing a single sperm nucleus, before it finally enters one SPZ and fuses with the chosen sperm pronucleus. These migrations of the egg pronucleus occur over several millimeters and take hours, but the mechanism underlying the motion or how the egg pronucleus decides which SPZ to enter is not yet known. Under our experimental conditions the mitotic apparatus and the first cleavage plane which defines the oral-aboral axis of the larva (see Reverberi (1971). "Experimental Embryology of Marine and Fresh-Water Invertebrates." North-Holland, Amsterdam. for review) pass through the point of sperm entry. During fertilization and cleavage, movements of a cortical autofluorescent material are clearly seen. This material is segregated into micromeres as cleavage progresses.

Sperm chemotaxis in siphonophores. II. Calcium-dependent asymmetrical movement of spermatozoa induced by the attractant

Spermatozoa from siphonophores have been shown to be attracted towards an extracellular structure, the cupule, which covers the predetermined site of fertilization of the egg. Observations on sperm behaviour during the chemotactic response show that spermatozoa describe trajectories of large diameter (700-1000 micron) while far from the cupule, and of smaller diameter (200 micron) in the cupule area. The transition between the two types of swimming occurs progressively when spermatozoa cross a 3 mm wide area around the cupule. After a few minutes 99% of the spermatozoa keep swimming around the attractant source, following circular paths 150–200 micron in diameter. In the absence of the attractant, comparable modifications of sperm trajectories are observed in the presence of the ionophore A23187 and high calcium concentrations. In the presence of 10(−2) M calcium ions, A23187-treated spermatozoa describe trajectories 200 micron in diameter, which increase up to 800 micron at lower calcium concentrations (10(−6) M). In the absence of calcium ions, spermatozoa swim across the cupule area without modification of their trajectories and no sperm accumulation can be detected. This requirement of the chemotactic response for calcium ions is observed either with fresh cupules stuck on the eggs, with cupules separated from the eggs, or with cupule extracts. Moreover, a soluble component fractionated from the cupule induces, when diluted in sea water, a reduction in the size of the sperm trajectories and this also requires calcium ions. The present data show that the chemotactic response of siphonophore sperm, which requires millimolar concentrations of calcium ions, occurs through a non-transient induction of increased asymmetry of the flagellar waveform. It is proposed that the natural attractant operates to produce an increase in the intraaxonemal calcium concentration.

[Hypothesis on the mechanism of cnidocyst discharge (author's transl)]

The geometic aspects of the cnidocystic filament before invagination, during invagination and after the process of evagination are shown. Experiments are described that allow an approach to study the mechanism of discharge. It is suggested here that the filament is an elastic tube which, when it is intracapsular, is folded and spiraled and thus, under a constraining action. Evagination then consists simply in the release of the constraining force and reversion of the filament to the primitive cylindric shape. The presence of water seems indispensable to the process to take place; however this does not necessarily imply that a hydratation take place in the filament wall. It also seems obvious that if expansion is a normal tendency of the constrained filament, eversion is a result of the continuity between the wall of the filament and that of the capsule. In conclusion, the invagination of the tube during cnidogenesis may be interpreted as a mean of storing energy for the evagination.