Contrast Inversion in TEM Studies of Poly(ferrocenylsilane)‐block‐Poly(dimethylsiloxane) Diblock Copolymers

This paper describes an unusual contrast inversion phenomenon in TEM imaging of PFS‐b‐PDMS block copolymer bulk samples. It is clearly observed especially in samples that show a lamellar morphology that the contrast inversion is accompanied by a contraction of the PDMS domains and an expansion of the Fe‐rich domains. The location of the iron‐ and silicon‐rich domains was monitored by EDX analysis. We infer that the contrast inversion was caused by electron beam radiation‐induced damage to, and possible cross‐linking of, PDMS chains. A simple way to selectively deposit metal on electron beam patterned polymer film was demonstrated.

     

Pregnancy-associated glycoprotein (PAG) family localized in chorionic cells within the epitheliochorial/diffuse placenta of the alpaca (Lama pacos)

Pregnancy-associated glycoproteins (PAGs) are abundant embryo-originated products expressed in the pre-placental trophoblast and later in the post-implantational chorionic epithelium of some ungulate species. This paper describes the cellular immunolocalization of the chorionic PAG family in the epitheliochorial placenta type of the alpaca (Lama pacos—Lp), in which the PAGs were named ‘LpPAGs’. Placental Lp sections (5 μm) of different females near mid-pregnancy (150 days post coitum; dpc), advanced pregnancy (244-263 dpc) and late pregnancy (347 dpc) were used for cross-species (heterologous—ht) double fluorescent immunohistochemistry (htdF-IHC). The htdF-IHC was performed with primary rabbit polyvalent anti-porcine PAG polyclonals. The LpPAG immuno-complexes were visualized with secondary goat anti-rabbit immunoglobulins-conjugated with Alexa 488 fluorophore (green), among all nuclei of placental cells stained with propidium iodide (red). This is the first study reporting the immunolocalization of the LpPAG family identified by htdF-IHC at the feto/maternal interface during different pregnancy stages of the alpaca. The most dominant and strongest immune-positive LpPAG signals were found in the well-developed chorionic cell layer. Our htdF-IHC indicated relatively high epitope resemblance to that of the PAGs in camelids and pigs. These data increase our general knowledge of chorionic PAG localization during pregnancy-stage dependent development of the epitheliochorial diffuse placenta type in the alpaca.     

Distinct roles of CSF family cytokines in macrophage infiltration and activation in glioma progression and injury response

Gliomas attract brain‐resident (microglia) and peripheral macrophages and reprogram these cells into immunosuppressive, pro‐invasive cells. M‐CSF (macrophage colony‐stimulating factor, encoded by the CSF1 gene) has been implicated in the control of recruitment and polarization of macrophages in several cancers. We found that murine GL261 glioma cells overexpress GM‐CSF (granulocyte–macrophage colony‐stimulating factor encoded by the CSF2 gene) but not M‐CSF when compared to normal astrocytes. Knockdown of GM‐CSF in GL261 glioma cells strongly reduced microglia‐dependent invasion in organotypical brain slices and growth of intracranial gliomas and extended animal survival. The number of infiltrating microglia/macrophages (Iba1⁺ cells) and intratumoural angiogenesis were reduced in murine gliomas depleted of GM‐CSF. M1/M2 gene profiling in sorted microglia/macrophages suggests impairment of their pro‐invasive activation in GM‐CSF‐depleted gliomas. Deficiency of M‐CSF (op/op mice) did not affect glioma growth in vivo and the accumulation of Iba1⁺ cells, but impaired accumulation of Iba1⁺ cells in response to demyelination. These results suggest that distinct cytokines of the CSF family contribute to macrophage infiltration of tumours and in response to injury. The expression of CSF2 (but not CSF1) was highly up‐regulated in glioblastoma patients and we found an inverse correlation between CSF2 expression and patient survival. Therefore we propose that GM‐CSF triggers and drives the alternative activation of tumour‐infiltrating microglia/macrophages in which these cells support tumour growth and angiogenesis and shape the immune microenvironment of gliomas. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Melanoma of choroid during pregnancy: case report

PURPOSE: To estimate the influence of pregnancy on the development and treatment of choroidal melanoma. MATERIAL AND METHODS: 8 pregnant women in the age of 20 to 35 years were observed. Various methods of treatment were applied: enucleation of the eye, photocoagulation and brachytherapy. 6 women delivered healthy babies, in 1 case an abortion happened and the child died, in 1 case therapeutic abortion was performed. The time of observation was 4 to 11 years, (average 6.8 year). RESULTS: The majority of patients visited the ophthalmologist for the first time during pregnancy or just after delivery, because they noticed impairment of vision in the eye with tumor. One can suppose, that during pregnancy the tumors growth is fast. Regression of the tumor after treatment was observed in 4 cases. In 4 women the eye was enucleated. 7 women are still alive. Only in one case metastases to the liver and the lungs occurred and the patient died. Considering the lack of estrogen and progesterone receptors in melanoma, this can be explained by the decreased immunity of the pregnant women organisms. Our observations do not reveal any negative influence upon pregnancy as the results of the treatment. Photocoagulation of the tumor can be performed safely during the first months of pregnancy. It seems, that brachytherapy is safer towards the end of pregnancy or after delivery.     

Occupational exposure to organic dust associated with municipal waste collection and management

The aim of the study was to assess the occupational exposure of workers employed in the municipal waste collection and management industry. Air samples were collected in the workers' breathing zone; two samples were collected parallely. The assessment concerned exposure to organic dust, endotoxins, bacteria and fungi. The questionnaire data showed that workers found themselves in good or very good health. They also regarded noise, dustiness, odor, physical effort and changeable atmospheric conditions as the most strenuous factors. The highest dust concentrations were observed on the sites of waste collection (mean, 7.7 mg/m3) and composting (mean, 4.6 mg/m3). Samples collected on the composting site contained the largest amount of endotoxins (mean concentration, 76 ng/m3). This was followed by sorting facility (61 ng/m3) and waste collection area (36 ng/n3). Gram-negative rods (primarily intestinal) were found in all samples collected at workposts, which justified the adoption of the air concentrations of endotoxins as a criterion for assessing their hygienic conditions. Taking MAC for total suspended dust (4.0 mg/m3) and the concentration of 10 ng/m3 for endotoxin as the criteria for the exposure evaluation, it must be considered that waste collectors and composting site workers are working in poor hygienic conditions. Workers employed at the most hazardous workposts did not use personal protective equipment (glasses, antirespirators), thus infringing a fundamental condition for limiting health hazards (Directive 2000/54/EC).     

Identification of a cone bipolar cell in cat retina which has input from both rod and cone photoreceptors

It has been generally accepted that rod photoreceptor cells in the mammalian retina make synaptic contact with only a single population of rod bipolar cells, whereas cone photoreceptors contact a variety of cone bipolar cells. This assumption has been challenged in rodents by reports of a type of cone bipolar cell which receives input from both rods and cones. Questions remained as to whether similar pathways are present in other mammals. We have used an antiserum against the glutamate transporter GLT1-B to visualize a population of cone bipolar cells in the cat retina which make flat contacts with axon terminals of both rod and cone photoreceptor cells. These cells are identified as OFF-cone bipolar cells and correspond morphologically to type cb1 (CBa2) cone bipolar cells which are a major source of input to OFF-beta ganglion cells in the cat retina. The GLT1-B transporter was also localized to processes making flat contacts with photoreceptor terminals in rat and rabbit retinas. Examination of tissue processed for the GluR1 glutamate receptor subunit showed that cb1 cone bipolar cells, like their rodent counterparts, express this alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-selective receptor at their contacts with rod spherules. Thus, a direct excitatory pathway from rod photoreceptors to OFF-cone bipolar cells appears to be a common feature of mammalian retinas.     

Correlation of brain stem evoked response audiometry (BERA) with Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS)

The diagnostic value of electric responses from the brain stem (BERA) in neurosurgical patients is still a matter for debate in the literature. Therefore in the study an attempt was made to determine the relationship between GCS scores and BERA recordings. Participants in the study were 64 patients with various types of brain damage. Evoked potentials from the brain stem were registered using the Hortmann BERAmodul apparatus. To facilitate the interpretation of results a special scale was developed for quantitative measurement of changes in BERA recordings. Abnormalities in BERA recordings were reflected in changes in GCS scores, and correlation between the two dimensions was found to be statistically significant. The relationship between BERA recordings and GOS scores was also significant: pathological changes in BERA recordings assessed as severe were associated with an unfavorable therapeutic outcome in the GOS. The presented findings indicate auditory evoked brain stem response (BERA) usefulness for objective evaluation of brain-damaged patients' clinical state.     

tGLP-1 action on the isolated hypothalamo-neurohypophysial system under glutamate receptor blockade

The isolated rat hypothalamo-neurohypophysial system was used to investigate possible mechanisms of glucagon-like peptide-1 (7-36) amide (tGLP-1) effects on the vasopressin/oxytocin (AVP/OXY) release. The non-selective inhibition of synaptic transmission as brought about by excess of MgSO(4) in the incubation medium completely abolished the tGLP-1-induced AVP release and attenuated OXY secretion. The non-specific blockade of excitatory amino acid receptors with kynurenic acid (KA) completely suppressed the tGLP-1-induced AVP but not OXY release. Specific inhibition of NMDA receptors suppressed the tGLP-1-evoked AVP release without affecting tGLP-1-induced OXY secretion. Selective blockade of non-NMDA receptors did not affect either tGLP-1-induced AVP or OXY release. It is concluded that tGLP-1 can influence the function of AVP neurons indirectly, most probably via the glutamatergic system through NMDA receptors. On the other hand, tGLP-1-evoked activation of OXY neurons, at least in part, seems to be a result of direct tGLP-1 activation of these neurons.     

Agonist-stimulated cobalt uptake provides selective visualization of neurons expressing AMPA- or kainate-type glutamate receptors in the retina

Fast-acting excitatory neurotransmission in the retina is mediated primarily by glutamate, acting at alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) -selective and kainate-selective receptors. To localize these sites of action, cat retinas were stimulated with either AMPA or kainate and processed for histochemical visualization of cobalt uptake through calcium-permeable channels. Treatment with both agonists resulted in staining of A- and B-type horizontal cells and several types of OFF cone bipolar cells; there was no evidence for staining of ON cone bipolar cells or rod bipolar cells. The subpopulations of OFF cone bipolar cells differed in their responses with two distinct types that stained heavily with cobalt after exposure to AMPA and three different types that were preferentially labeled after exposure to kainate. Although many amacrine and ganglion cells appeared to respond to both agonists, AII amacrine cells were stained after stimulation by AMPA but not by kainate. The OFF cone bipolar cells that exhibit AMPA-stimulated cobalt uptake were found to have a high level of correspondence with cells that show immunocytochemical staining for the AMPA-selective glutamate receptor subunits GluR1 and GluR2/3. Similarly, the cone bipolar cells exhibiting kainate-stimulated cobalt uptake resemble those that are immunoreactive for the kainate subunit GluR5. The results indicate that, whereas many retinal neurons express both AMPA and kainate receptors, AII amacrine cells and subpopulations of OFF cone bipolar cells are limited to the expression of either AMPA or kainate receptors. This differential expression may contribute to the unique character of transmission by these cell types.     

Electrocardiographic signs of right ventricular overload useful in improving diagnosis of chronic thromboembolic pulmonary hypertension (CTE-PH) in patients with chronic exertional dyspnea

The early recognition of chronic thromboembolic pulmonary hypertension (CTE-PH) is troublesome because of "honey moon" period with chronic dyspnea on exertion as the only one symptom. To find if routine electrocardiography may be useful in improving the diagnosis, value of right ventricular overload (RVO) signs in recognition echocardiographically determined chronic pulmonary hypertension (CPH) and angiographically confirmed CTE-PH in 90 consecutive patients hospitalized due to chronic exertional dyspnea was studied. CPE was found in 76.5% and CTE-PH in 33% of those patients, at least one of twelve founded electrocardiographic signs of RVO was present in 50% patients. The most frequently occurred signs: negative T wave in lead V1-V6, right axis deviation and pulmonale P wave as well as 9 other occurred at frequency below 20% signs of RVO had low to medium sensitivity and negative predictive value and 80-90% positive predictive value for diagnosing CPE and 90-100% positive predictive value for diagnosing CTE-PH. It was concluded that in patients with chronic exertional dyspnea electrocardiographic signs of RVO may be useful in initial diagnosing of CPH and CTE-PH in particular.