The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias.

Results from this study of the white shark Carcharodon carcharias include measurements obtained using a novel photographic method that reveal significant differences between the sexes in the relationship between tooth cuspidity and shark total length, and a novel ontogenetic change in male tooth shape. Males exhibit broader upper first teeth and increased distal inclination of upper third teeth with increasing length, while females do not present a consistent morphological change. Substantial individual variation, with implications for pace of life syndrome, was present in males and tooth polymorphism was suggested in females. Sexual differences and individual variation may play major roles in ontogenetic changes in tooth morphology in C. carcharias, with potential implications for their foraging biology. Such individual and sexual differences should be included in studies of ontogenetic shift dynamics in other species and systems.

A rare clinical entity: stump appendicitis. Case report and complete review of literature.

BACKGROUND: Stump appendicitis is a rare delayed complication post-appendectomy and it represents a diagnostic problem as clinicians are often not very familiar with this pathology. MATERIALS AND METHODS: One case of stump appendicitis has been reported in a 54 year old woman, whose acute phase was conservatively treated in our Department. A review of Medline literature was also carried out, from 1945 to 2015, showing 111 cases of stump appendicitis. RESULTS: Stump appendicitis has been reported after either open or laparoscopic appendectomy, in a range between days to several years from the first procedure. Nowadays, it is not considered yet as a possible differential diagnosis in patients with pain in the right iliac fossa previously undergone appendectomy. For this reason, the diagnosis can be delayed and complications such as acute abdomen, perforation, sepsis can occur. Completion appendectomy is the treatment of choice for stump appendicitis. CONCLUSIONS: The aim of this article is to underline the importance of stump appendicitis. Clinicians should be aware of the possibility of SA and they should confirm any clinical suspicion throughout radiologic images, in order to promptly recognize this entity and to avoid the related complications.

New records of oribatid mites (Acari: Oribatida) from Argentina.

A taxonomic inventory of oribatid mites from lenga forests in Patagonia Argentina was carried out to assess the taxonomic diversity and to increase the knowledge of their distribution. Nine new records of soil oribatid mites from Argentina are reported. Those species were collected in Chubut province and Tierra del Fuego province. The new registered species belong to the genera Lamellozetes, Hermannia (Phyllhermannia), Crotonia, Kokoppia, Acutoppia, Lanceoppia (Baioppia), Loboppia, Membranoppia(Membranoppia) and Graptoppia (Stenoppia).

Sex, size and isotopes: cryptic trophic ecology of an apex predator, the white shark Carcharodon carcharias.

Demographic differences in resource use are key components of population and species ecology across the animal kingdom. White sharks (Carcharodon carcharias) are migratory, apex predators, which have undergone significant population declines across their range. Understanding their ecology is key to ensuring that management strategies are effective. Here, we carry out the first stable isotope analyses of free-swimming white sharks in South Africa. Biopsies were collected in Gansbaai (34.5805°S, 19.3518°E) between February and July 2015. We used Stable Isotope Bayesian Ellipsis in R and traditional statistical analyses to quantify and compare isotopic niches of male and female sharks of two size classes, and analyse relationships between isotopic values and shark length. Our results reveal cryptic trophic differences between the sexes and life stages. Males, but not females, were inferred to feed in more offshore or westerly habitats as they grow larger, and only males exhibited evidence of an ontogenetic niche shift. Lack of relationship between δ13C, δ15N and female shark length may be caused by females exhibiting multiple migration and foraging strategies, and a greater propensity to travel further north. Sharks < 3 m had much wider, and more diverse niches than sharks > 3 m, drivers of which may include individual dietary specialisation and temporal factors. The differences in migratory and foraging behaviour between sexes, life stages, and individuals will affect their exposure to anthropogenic threats, and should be considered in management strategies.

Videolaparoscopic cholecystectomy in patients with previous abdominal surgery. Personal experience and literature review.

OBJECTIVES: Laparoscopic cholecystectomy (LC) is today the "gold standard" treatment of gallbladder stones. Role of LC is still debated in the presence of abdominal scars due to the frequent post-operative adhesions which make access to the peritoneal cavity difficult. This study aim to assess role and outcomes of LC on a previous abdominal surgery on the scarred abdomen. MATERIALS AND METHODS: We have carried out a retrospective study on 499 consecutive patients who had undergone LC from 2009 to 2015; 21 of these (4.2%) undergone previous abdominal surgery. In all 21 cases the pneumoperitoneum was established with Veress needle at the Palmer's point and the procedure was carried out after adhesiolysis in 62% of cases. RESULTS: The mean operative time was 79±12 minutes; none of the patients with previous abdominal surgery required conversion to open cholecystectomy and there were no postoperative complications related to Veress introduction or to the adhesiolysis. The difficult dissection and adhesiolysis were more frequent in the patients with upper abdomen scar (62%) respect to lower abdomen scar (38%). CONCLUSIONS: Patients with scarred abdomen for previous abdominal surgery had obviously more adhesions in the abdomen than patients without preceding surgery, but today previous abdominal surgery should not constitutes absolute contraindications to LC. Moreover, patients with previous lower abdominal incisions had fewer adhesions in the upper abdomen than did patients with upper incision and, probably, in these cases adhesiolysis is unnecessary, if the surgical field is well exposed whereas adhesiolysis is mandatory when the adhesions are thick and widespread, to the anterior and posterior abdominal wall.

Toxic polyneuropathies in Italy due to leather cement poisoning in shoe industries. A light- and electron-microscopic study.

The peripheral nerve biopsy specimens of 4 cases of toxic polyneruopathies induced by exposure to leather cement in shoe industries were studied. Analysis of the cements used in the manufacturing process proved them to contain n-hexane as a volatile substance. Light- and electron-microscopic examination of nerve biopsies showed segmental swelling of axons due to the accumulation of packed filaments and thinning of the overlying myelin sheath. Neither active nerve fibre degeneration nor regeneration were frequently seen. It has been suggested that features of so-called giant axonal neuropathy are the most common pattern of peripheral nerve degeneration in chronic n-hexane intoxication.

Neuropsychological characteristics of parkinsonian patients with lateralized motor impairment.

Parkinsonians with predominantly unilateral signs provide an interesting experimental means to evaluate if asymmetric nigro-striatal degeneration may affect neuropsychological functions. The aim of our study was to establish if the side of onset of idiopathic Parkinson's disease, right (PDR) or left (PDL), determines a selective pattern of cognitive performances. Furthermore, we verified if PDR and PDL groups show a different frequency of dementia. PDR and PDL patients with at least seven years of disease duration, matched for age, schooling, severity of extrapyramidal symptomatology and index of lateralization, were evaluated by using an extensive neuropsychological battery aimed at assessing hemispheric cognitive asymmetries. Current side of greater motor impairment was the same as the one affected at the onset of the disease. Only subtle differences in the profile of neuropsychological dysfunction emerged from the comparison of PDR and PDL subjects. Moreover, the number of parkinsonians showing dementia syndrome was the same in both groups. Our results suggest that the side of onset of motor impairment does not significantly influence the cognitive performances in PD. Subcortical anatomic and/or functional asymmetries seem to play a less important role in the intellectual functions than in motor activities.

Clinical spectrum of the tomaculous neuropathies. Report of 60 cases and review of the literature.

Tomaculous neuropathy has a distinctive pathological pattern of myelin thickenings in a high proportion of internodes but no specific pattern of nerve degeneration. We have analyzed the variable clinical expression of this disorder in a large series of patients. Different phenotypes have been recognized: the majority of our patients (52 cases) had hereditary neuropathy with liability to pressure palsy (HNPP) showing wide variability of clinical progression and of severity of the single episodes. 3 patients suffered from familial recurrent brachial plexus neuropathy (FBPN); 5 patients had a symmetrical progressive sensorimotor involvement of the limbs (SSMN), predominantly in the distal portions and leading to permanent disability. The explanation for this clinical variability does not emerge from our data or from the literature. Segmental demyelination is the major change correlating with the episodes of nerve palsy; axonal degeneration might be rarely associated. The myelin sausages are the markers of a selective vulnerability of the nerve fibers either to mechanical injury or to some other unknown event.

Altered thiol group status in the heart ornithine decarboxylase inactivated following perfusion with t-butylhydroperoxide.

1. The perfusion for 15 min of isolated rat hearts with 100 microM t-butylhydroperoxide leads to a 75% diminuition of the tissue GSH/GSSG ratio. 2. After t-butylhydroperoxide infusion, the isoproterenol-stimulated heart ODC was strongly inhibited. The addition of 2 mM DTT in the assaying buffer removed the ODC inactivation. 3. The inhibited ODC had an eluition profile similar to active ODC when chromatographed on a Sephacryl S-200 column; moreover, the ODC activity recovered after a thiol affinity chromatography as unbound fraction, was two times increased in the t-butylhydroperoxide perfused hearts in comparison to control. 4. The hearts perfused with 1 mM acetylcysteine after 15 min of perfusion with t-butylhydroperoxide recovered almost completely the initial ODC activity.

Congenital toxoplasmosis: histological and ultrastructural study.

A case of congenital toxoplasmosis is reported in which the patient died at 32 days following seizures, coma and respiratory disturbances. Neuropathological examination showed numerous foci of softening throughout the brain. Histological examination disclosed widespread areas of inflammatory necrosis. Circumscribed areas of granulomatous inflammation were also found. Cysts containing a variable number of microorganisms and toxoplasmas free in the damaged areas were frequently observed. Small calcifications were scattered in the cerebral cortex and basal ganglia. Electron microscopy of postmortem brain specimens demonstrated toxoplasmas at various stages of development. The microorganism is enveloped by a two-layered membrane, the pellicle. Replication occurs in a vacuole inside the host cell. Following replication the newly formed parasites, the trophozoites, are released. Several replications without release may also occur with consequent cyst formation. The motile form of the toxoplasma, the tachyzoite, is fusiform with truncated cone shape of the anterior ending which is the presenting surface modified for host cell penetration. The modality of transplacental transmission and the clinical syndromes associated with toxoplasma infection are discussed. EM even of post mortem material contributes to knowledge of the structure of the parasite and of its life cycles.

Focal lesions area feature of chronic inflammatory demyelinating polyneuropathy (CIDP).

In a study designed to identify the neuropathological features typical of chronic inflammatory demyelinating polyneuropathy (CIDP), we reviewed the sural nerve biopsy findings in 105 patients with this disorder. The patients' mean age at biopsy was 49 years. In 65% of patients the disease had a progressive and in 35% a relapsing-remitting course. In 47% of cases the disorder was idiopathic; the remainder had various concurrent conditions. All sural nerve biopsy specimens showed varying amounts of active demyelination associated with onion bulbs (48% of cases), endoneurial edema (55%) and inflammatory infiltrates (25%). The immunopathological hallmarks were T cell infiltration with macrophagic activation and up-regulation of major histocompatibility complex (MHC) class II expression, without B cell infiltration or immunoglobulin deposition on myelin sheaths. In 30% of cases some myelin sheaths showed C3d deposition. Analysis of proinflammatory cytokine expression invariably showed interleukin-1 in perivascular and endoneurial ramified cells and tumor necrosis factor-alpha prevalently in epineurial macrophages, whereas it detected interferon-gamma only in samples with perivascular inflammatory cells. This immunological pattern suggests that the cellular components of immunity play the major role in CIDP. In 19% of cases the neuropathological changes had a focal distribution. This distinctive feature corresponded to more active demyelination, more frequent detection of inflammatory infiltrates and more prominent immunological activation, suggesting that focal involvement is a possible step in the course of the disease.

Histopathological and ultrastructural study of a case of infantile metachromatic leukodystrophy.

The histopathological and ultrastructural findings on a nerve biopsy specimen and on a CNS necropsy specimen in a case of IML with a typical clinicaL course are reported. Nerve biopsy once again proved to be a sure diagnostic guide even at an early stage of the disease. Some differences in the fine structure of the cytosomes between the nerve biopsy and CNS necropsy material studied four years later may be due to the different rates of catabolism of the constituent lipids as well as to post mortem artefacts.

[Infantile neuro-axonal dystrophy: anatomo clinical study of one case (author's transl)]. / La distrofia neuro-assonale infantile. Studio anatomo-clinico di un case

A case of Seitelberger's infantile neuroaxonal dystrophy (a rare familial neurologic disease of childhood) is described. The clinical picture is characterized by a progressive deterioration of psychomotor functions leading to flaccid paraplegia with hypotonia of axial muscles, complete involution of language, and total loss of communication with the external world; death due to recurrent unassociated disease occurred at the age of 4 years. Histology showed numerous axonal spheroids mainly in the gray matter of the C.N.S. and plurisystemic degenerations of the motor and sensory systems, of the cerebellum, of the basal ganglia, and of specific sensory system such as the optic and (reported here for the first time) of the olfactory and acoustic systems. In particular, the main histopathological findings included: 1) a characteristic distribution of axonal swellings prevailing in the posterior horn of the spinal cord and in the dorsolateral portions of the medulla oblongata, mainly at the level of the sensory nuclei; 2) demyelinization of the pyramidal tracts and of the ascendings pathways of the sensory system with fibrillar gliosis and myelin breakdown products in some areas (internal capsule, pes pedunculi, VPL thalamic nuclei); 3) severe cerebellar atrophy with almost complete loss of granule and Purkinje cells and marked fibrillary gliosis; 4) presence of enormous amount of sudanophilic lipids in the striatum and pallidum; 5) optic, acoustic and olfactory system degeneration with demyelinization and gliosis at all levels examined and, in particular, sudanophilic lipid deposition in the optic radiations, trigone, and olfactory striae. The discussion emphasized the dying-back type of evolution of the degenerative process insofar as a) the spheroids represent a peculiar alteration of presynaptic endings (as demonstrated by electron microscopy) prevailing at the first sensory neuron, and b) in all systems involved, the degeneration is most marked at distal levels. The striato-pallidal lipophanerosis suggests that the sudanophilic lipids are, here as in other systems, parenchymal degeneration products. On the other hand, there are still many unresolved problems in this rare and complex disease, such as a) the predilection of the lesions for the sensory systems which in our case involved all three special senses; b) the extreme cerebellar atrophy; and c) the etiopathogenetic substrate of the process. All biochemical and histochemical studies have not yielded any results up to the present.

Friedreich's ataxia. A light- and electron microscopic study of peripheral nerve biopsies.

Sural or superficial peroneal nerve biopsies of patients with clinical diagnosis of Friedreich's ataxia were studied. Patients were divided in two groups, typical and abortive forms: loss of fibers accompanied by axonal atrophy and segmental demyelination are the basic changes in both groups, although the decrease in number of myelinated fibers was most severe in typical FA. In the cases with slower progression there is a tendency to form onion bulb complexes.

Role of HIV in the pathogenesis of distal symmetrical peripheral neuropathy.

We report the results of a clinical, electrophysiological and pathological study conducted in 18 AIDS patients presenting a distal symmetrical predominantly sensory polyneuropathy (DSPN) characterized by painful dysesthesias as main complaint. Onset of the neuropathy was at CDC (Center for Disease Control) stage II in 2 patients, at CDC stage III in 5 patients and at CDC stage IV in the remainder. Electrophysiological investigation confirmed the presence of an axonal alteration in the sensory nerves, but also revealed motor involvement in all cases. The neuropathological features of sensory nerves were fiber loss and axonal degeneration with macrophagic activation. The expression of monocyte-macrophage markers and of major histocompatibility complex class II antigens appeared up-regulated in endoneurial ramified cells, while expression of CR3, a complement receptor involved in the process of phagocytosis, was down-regulated. In six nerve biopsy samples and in two out of five DSPN dorsal root ganglia we found HIV-related mRNA and protein located in scattered cells of the endoneurium which we presume to be macrophages. These data suggest that: (a) DSPN may occur early in the course of the disease and is not limited to later stages; (b) DSPN is not a ganglionitis but is actually a sensory-motor neuropathy; (c) the virus enters the peripheral nervous system and induces changes in the immunocompetent cell population with activation of macrophages. Storage of the virus inside macrophages may act both as a reservoir for the virus and as a putative cause of nerve damage, probably through release of cytotoxins and/or interaction with trophic factors.