Behavioural strategies used by the hookworms Necator americanus and Ancylostoma duodenale to find, recognize and invade the human host

The infective third-stage larvae of the hookworms Necator americanus and Ancylostoma duodenale infect their human hosts by active skin invasion, but A. duodenale is in addition capable of oral infection. The behaviour of the larvae when crawling on surfaces has already been described. Here we analyse in various in vitro systems the other behavioural invasion phases: activation, penetration, and orientation within the host. The larvae normally remained in a motionless, energy-saving, resting posture. An activation to sinusoidal locomotion was stimulated in both species by similar cues such as touch, vibration, water currents, heat, light, and chemicals. Human breath in addition stimulated searching and waving (nictating) behaviour, which facilitates a change-over to the host. Activating cues in air streams were warmth and moisture; CO₂ activated only in combination with warmth and/or moisture. Penetration behaviour in both species was stimulated by warmth and skin extracts. The stimulating components of skin extracts were fatty acids, but their stimulating characteristics differed from those inducing schistosome cercarial skin penetration. After penetration into agar substrates, both species showed thermo-orientation, but only A. duodenale followed gradients of serum. The directing serum cues were not amino acids and glucose (the supposed cues for schistosome blood vessel localization), but Ringers solution attracted the larvae. The host-finding and host-invasion behaviour of both hookworm species is well adapted to the invasion of the human skin, and there seems to be no particular adaptation of A. duodenale behaviour to the oral infection mode. Hookworm host-finding behaviour is not as complex as that of schistosome cercariae but seems well adapted to the ecological conditions in the transmission sites.     

Fusion and Matrix Protein Gene Sequence Analysis of Paramyxoviruses of Type 1(PMV-1) Isolated from Pigeons in Slovenia

Paramyxoviruses of type 1 (PMV-l) isolated from pigeons were genetically analyzed. A part of the fusion and the matrix protein genes were amplified and sequenced, Typical amino acid sequences associated with virulence were determined at the fusion protein cleavage site in all PMV-1 isolates. All Slovene pigeon PMV-1 strains share high amino acid sequence similarity with other pigeon strains. In the phylogenetic tree, they are clustered together with pigeon PMV-1 isolates with moderate pathogenicity. Phylogenetic analysis obtained from the fusion and the matrix protein gene alignments showed the same branching order. Viruses circulating among pigeons were found to form quite unique lineage of virulent NDV strains.     

A subset of high-grade pulmonary neuroendocrine carcinomas shows up-regulation of matrix metalloproteinase-7 associated with nuclear β-catenin immunoreactivity,independent of EGFR and HER-2 gene amplification or expression

Nuclear translocation of β-catenin has been correlated with epidermal growth factor receptor (EGFR) overexpression/activation in nonsmall cell lung cancer. Less is known on β-catenin transactivation in high-grade pulmonary neuroendocrine tumors and on the status of β-catenin activating EGFR and human epidermal growth factor receptor 2 (HER-2) or β-catenin target genes cyclin D1 and matrix metalloproteinase-7 (MMP-7). β-catenin immunoreactivity was evaluated in 51 large-cell neuroendocrine carcinomas (LCNEC) and 45 small-cell lung carcinomas (SCLC). Nineteen cases were assessed for β-catenin gene exon 3 mutations, expression of MMP-7, and expression/gene amplification of EGFR, HER-2, and cyclin D1. β-catenin was expressed in all 96 high-grade neuroendocrine tumors, the vast majority (94%) showing >50% immunopositive cells. A disarrayed immunoreactivity, however, was commonly encountered consisting in variably altered membrane-associated patterns of staining along with progressive accumulation of cytoplasmic immunoreactivity. In LCNEC, but not in SCLC, the disarrayed patterns correlated with EGFR and HER-2 protein expression. β-catenin nuclear accumulation was found in nine tumors, including seven LCNEC and two SCLC, and was always associated with disarrayed immunoreactivity and increased MMP-7, but not cyclin D1 expression. These cases, however, did not show β-catenin gene mutations or EGFR and HER-2 gene amplification or expression. No association was found between nuclear β-catenin and any clinicopathological variable including patients' survival. The subcellular compartmentalization of β-catenin is profoundly altered in high-grade pulmonary neuroendocrine tumors. A minor subset of these tumors shows β-catenin nuclear accumulation in association with increased expression of MMP-7, but not of cyclin D1, independent of EGFR and HER-2 gene amplification or expression. The authors have no significant financial or other relationship with the manufacturers of any commercial products or commercial services presented in this paper     

Decreased prefrontal 5-HT2A receptor binding in subjects at enhanced risk for schizophrenia

The brain serotonin-2A receptor (5-HT_2AR) has been implicated in both the pathology of schizophrenia and the therapeutic action of atypical antipsychotics. However, little is known about the 5-HT_2AR status before the onset of schizophrenia and before the exposure to antipsychotics. We used [¹⁸F] altanserin and positron emission tomography (PET) in a pilot study of 6 individuals suspected to be at elevated risk for schizophrenia and seven age-matched controls to test the hypothesis that regional 5-HT_2AR binding is altered in the prodromal stages of schizophrenia. Distribution volume ratios (DVRs) as a proxy for 5-HT_2AR availability were significantly reduced in prefrontal cortex regions of at-risk subjects, implicating early abnormalities of serotonergic neurotransmission that antecede the onset of schizophrenia.     

Regional difference in the appearance of apoptotic cell death in the ligamentum flavum of the human cervical spine

Ossification or calcification of the ligamentum flavum (LF) is relatively common in the middle and lower cervical, thoracic, and lumbar spine but extremely rare in the upper cervical region. This clinical fact suggests that there exist local factors promoting or preventing ossification or calcification of LF. However, little is known about the differences in the ultrastructure and cellular alterations of the LF between the different spinal levels, even in the cervical spine. With electron microscopy, we examined samples of LF collected surgically from the upper and lower cervical spine regions; we then studied the apoptotic appearance of ligament cells using a preferential labeling method. We found direct evidence of apoptosis of ligament cells in the LF. Apoptosis was more apparent in the upper region samples than in the lower region samples. The spaces around the normal fibroblasts were filled with thick collagen fibrils, but the collagen fibrils disappeared around the apoptotic bodies and thin fibrils were formed. The difference of the level of apoptosis may correlate to the ultrastructual difference of LF, and our data will benefit further investigations seeking to clarify the mechanism of various pathological conditions in the human LF.     

IL-18 Receptor Expression on Epithelial Cells is Upregulated by TNF Alpha

IL-18 is a multifunctional cytokine that augments both innate and acquired immunity and potentiates Th1 and Th2 reactions. We studied the expression of IL-18 receptor (IL-18R) on renal and respiratory epithelial cell lines. Both cell lines upregulated IL-18R mRNA and IL-18R membrane expression in response to TNF alpha and other proinflammatory cytokines. The function of IL-18R was confirmed by induction of IL-8 release from epithelial cells in response to recombinant IL-18. Epithelial cells may represent an important target for IL-18, mainly under inflammatory conditions associated with TNF alpha release.     

Human osteoblast response to pulsed laser deposited calcium phosphate coatings

Octacalcium phosphate (OCP) and Mn(2+)-doped carbonate hydroxyapatite (Mn-CHA) thin films were deposited on pure, highly polished and chemically etched Ti substrates with pulsed laser deposition. The coatings exhibit different composition, crystallinity and morphology that might affect their osteoconductivity. Human osteoblasts were cultured on the surfaces of OCP and Mn-CHA thin films, and the cell attachment, proliferation and differentiation were evaluated up to 21 days. The cells showed a normal morphology and a very good rate of proliferation and viability in every experimental time. Alkaline phosphatase activity was always higher than the control and Ti groups. From days 7 to 21 collagen type I production was higher in comparison with control and Ti groups. The level of transforming growth factor beta 1 (TGF-beta1) was lower at 3 and 7 days, but reached the highest values during following experimental times (14 and 21 days). Our data demonstrate that both calcium phosphate coatings favour osteoblasts proliferation, activation of their metabolism and differentiation.     

Detecting danger--or just another odorant? Olfactory sensitivity for the fox odor component 2,4,5-trimethylthiazoline in four species of mammals

2,4,5-trimethylthiazoline (TMT) is a volatile component of the anal gland secretion of the red fox and elicits behavioral and physiological fear responses in the rat. Using instrumental conditioning paradigms, we determined olfactory detection thresholds for TMT in three rats, a natural prey species of the red fox, and compared their performance to that of three squirrel monkeys, three spider monkeys and four pigtail macaques, all non-prey species of the red fox. We found that the rats were able to discriminate concentrations between 0.04 and 0.10 ppt (parts per trillion) of TMT from the odorless solvent which is by far the lowest olfactory detection threshold for an odorant reported in rats so far. In contrast, the spider monkeys needed 0.14-1.38 ppb (parts per billion), the pigtail macaques 0.41-4.07 ppb, and the squirrel monkeys 4.07-13.80 ppb to detect TMT which does not rank among the lowest olfactory thresholds reported for these three primate species. Thus, these results support the assumption that the behavioral relevance of an odorant may be an important determinant of a species' olfactory sensitivity.     

Human testicular protein TPX1/CRISP-2: localization in spermatozoa, fate after capacitation and relevance for gamete interaction

Testicular protein Tpx-1, also known as CRISP-2, is a cysteine-rich secretory protein specifically expressed in the male reproductive tract. Since the information available on the human protein is limited to the identification and expression of its gene, in this work we have studied the presence and localization of human Tpx-1 (TPX1) in sperm, its fate after capacitation and acrosome reaction (AR), and its possible involvement in gamete interaction. Indirect immunofluorescence studies revealed the absence of significant staining in live or fixed non-permeabilized sperm, in contrast to a clear labelling in the acrosomal region of permeabilized sperm. These results, together with complementary evidence from protein extraction procedures strongly support that TPX1 would be mainly an intra-acrosomal protein in fresh sperm. After in vitro capacitation and ionophore-induced AR, TPX1 remained associated with the equatorial segment of the acrosome. The lack of differences in the electrophoretic mobility of TPX1 before and after capacitation and AR indicates that the protein would not undergo proteolytical modifications during these processes. The possible involvement of TPX1 in gamete interaction was evaluated by the hamster oocyte penetration test. The presence of anti-TPX1 during gamete co-incubation produced a significant and dose-dependent inhibition in the percentage of penetrated zona-free hamster oocytes without affecting sperm motility, the AR or sperm binding to the oolema. Together, these results indicate that human TPX1 would be a component of the sperm acrosome that remains associated with sperm after capacitation and AR, and is relevant for sperm-oocyte interaction.     

Herpes zoster and post-herpetic neuralgia--a clinical trial of aspirin in chloroform for anodyne

Pain associated with Herpes Zoster (HZ) and Post-herpetic Neuralgia (PHN) has been a challenging task to manage with ease. Topical aspirin dissolved in chloroform is an effective means of reducing pain due to HZ and PHN in most patients. The locus of pain origin and analgesia induced by topical aspirin is supposed to be at cutaneous free nerve ending pain receptors. The present study was conduced in fifty two patients of HZ and PHN. Pain intensity before and after the application of drug was measured with help of Sort Form McGill Pain Questionnaire (SE-MPQ). Most of the patients experienced relief of pain within 1-5 minutes after the aspirin-chloroform application. Maximum relief was achieved in about 30-40 minutes and persisted for 5-6 hrs. In the beginning 3-4 applications were required but frequency decreased gradually as the pain abated.