Cells respond to deletion of CAV1 by increasing synthesis of extracellular matrix

A range of cellular functions have been attributed to caveolae, flask-like invaginations of the plasma membrane. Here, we have used RNA-seq to achieve quantitative transcriptional profiling of primary embryonic fibroblasts from caveolin 1 knockout mice (CAV1-/- MEFs), and thereby to gain hypothesis-free insight into how these cells respond to the absence of caveolae. Components of the extracellular matrix were decisively over-represented within the set of genes displaying altered expression in CAV1-/- MEFs when compared to congenic wild-type controls. This was confirmed biochemically and by imaging for selected examples. Up-regulation of components of the extracellular matrix was also observed in a second cell line, NIH-3T3 cells genome edited to delete CAV1. Up-regulation of components of the extracellular matrix was detected in vivo by assessing collagen deposition and compliance of CAV1-/- lungs. We discuss the implications of these findings in terms of the cellular function of caveolae.

Comparison of the bactericidal effect of cold atmospheric pressure plasma (CAPP), antimicrobial photodynamic therapy (aPDT), and polihexanide (PHX) in a novel wet surface model to mimic oral cavity application

PURPOSE

Cold atmospheric pressure plasma (CAPP) is increasingly used for medical applications. The first devices are available from commercial manufactures, promising to improve wound healing and disinfection. The underlying antimicrobial mechanisms of CAPP are discussed, while the first results on its bactericidal efficiency against common bacterial species have already been published, with promising results. Most of the plasma sources used in these studies were built by the investigators themselves, and are not commercially available or licensed for clinical use. To evaluate the postulated bactericidal effects in clinical practice, we studied a commercially available, ready-to-use CAPP-device, which is also designed to be used in the field of dental, oral, and maxillofacial treatment.

MATERIALS AND METHODS

Standardized bacterial cultures of two different pathogens (Acinetobacter baumannii and Staphylococcus aureus) were produced with defined colony-forming unit concentrations. Dilutions of these cultures were treated with a commercially available CAPP product according to the manufacturer's instructions in order to evaluate the antimicrobial activity of the technique. This in vitro study compared the CAPP treatment with established clinical therapies like polihexanide (PHX) and antimicrobial photodynamic therapy (aPDT).

RESULTS

The bactericidal effect was evaluated in terms of reduction in colony-forming units after treatment of the bacterial samples with a defined dose of plasma, aPDT, or PHX. For CAPP, the bactericidal effect was found to be stronger in the Gram-negative isolate (A. baumannii) than in the Gram-positive S. aureus. A strong depth dependency was observed, especially with the Gram-negative isolate. Good bactericidal effects, with a reduction in bacterial load of more than 2 × log₁₀, could only be observed in conditions of 0.3 mm of water-film thickness or less. Such a significant reduction in bactericidal effect depending on depth was not observed using aPDT or PHX in the studied depth range of 0.3-1.8 mm.

CONCLUSION

CAPP treatment performed by the device (Plasma ONE) and configuration we used in this study seems to be ill suited for sufficiently killing Acinetobacter baumannii or Staphylococcus aureus in a moist infection site, as would be expected in the oral cavity. Established local antimicrobial therapies using PHX or aPDT showed better disinfectant properties. The clinical effect of improved wound healing, described by the manufacturer and some scientists, could not be investigated using this model. Given the results, however, it seems unlikely to be a direct consequence of bactericidal effects of CAPP in a wet environment. Further development of CAPP devices, or a different configuration (e.g. with a higher output, resulting in reactive nitrogen species-dominated, gas-phase chemistry), may enhance antibacterial effects in future, while tissue compatibility of such techniques remains to be elucidated further.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Neuronal Ceroid-Lipofuscinosis in a Holstein Steer

A young, partially blind Holstein steer was affected by mild cerebral atrophy. Formalin-fixed cerebral gray matter was diffusely yellow brown. Microscopically, there were eosinophilic, autofluorescent granules primarily in the cytoplasm of cerebral neurons. There was also extensive retinal atrophy with complete loss of the rod and cone layers. Ultrastructural examination of affected cerebral neurons revealed a mixture of granular osmiophilic and lamellar patterns in the cytoplasmic storage bodies. This suggests the existence of neuronal ceroid-lipofuscinosis in the Holstein breed.

Prevalence of nosocomial pathogens in German ambulances: the SEKURE study

OBJECTIVE

The increasing prevalence of multidrug resistant bacteria is a problem in the inpatient care setting, and in the emergency care system. The aim of this observational, cross-sectional study was to evaluate the prevalence of pathogens on well-defined surfaces in German ambulances that have been designated as 'ready for service'.

METHODS

After informed consent was obtained, ambulance surfaces were sampled with agar plates for microbiological examination during an unannounced visit. A standardised questionnaire was used to obtain information regarding the disinfection protocols used at each rescue station.

RESULTS

Methicillin resistant staphylococcus aureus contamination was present in 18 sampling surfaces from 11 out of 150 ambulance vehicles (7%) that were designated as ready for service. Contact surfaces directly surrounding patients or staff were most frequently contaminated with pathogens. However, bacterial contamination was not related to annual missions, methods or frequency of disinfection.

CONCLUSIONS

In accordance with previous studies, disinfection and cleaning of areas with direct contact to patients or staff seem to be the most challenging. This should also be reflected in disinfection guidelines and the related continuing education.

Green algal peritonitis in 2 cows

Peritonitis due to infections with green algae was diagnosed at slaughter (in Texas and South Dakota) in 2 cows. One cow also had a generalized lymphadenitis. The intralesional green algae were histologically similar to those previously associated with bovine lymphadenitis. Amplified and sequenced algal ITS2 genes had higher homology with the genus Scenedesmus than with Chlorella.

Metastatic melanomas in young broiler chickens (Gallus gallus domesticus)

Four young broiler chickens affected by multiple melanotic tumors are described. Grossly, there were multiple tumors composed of melanocytes within the skin, skeletal muscle, and multiple visceral organs. Tumors ranged from flattened macules to masses that extensively replaced viscera. Microscopically, melanocytes were often well pigmented, and while there was moderate nuclear anisokaryosis, mitotic rates were low. Immunohistochemical staining of some melanomas with antibodies to S100 proteins, Melan-A, vimentin, or neuron-specific enolase after bleaching of tumor cells with potassium permanganate revealed lack of immunostaining of tumor cells with antibodies to S100, strong positive staining of tumor cells for neuron-specific enolase, moderate staining with antibodies to vimentin, and faint staining for Melan-A. Only neuron-specific enolase staining was evident in unbleached tumor cells. Attempts to identify exogenous avian leukosis viruses in these tumors were unsuccessful.

Viral proventriculitis in chickens

The objectives of the present study were to examine proventriculi of broiler chicks for lesions, and to classify and record the incidence of these lesions. Deep non-purulent necrotizing proventriculitis (accompanied by adenoepithelial hypertrophy and hyperplasia) was the most common (109/220 = 49.5%) light microscopic diagnosis in the proventriculi examined. Degenerating and necrotic alveolar secretory cells had amorphous, granular or vacuolated cytoplasm. Nuclei usually were either pyknotic, karyorrhectic or karyolytic; however, fewer attached or sloughed cells had swollen nuclei with marginated chromatin and clear centres. Basophilic inclusion bodies were never seen. In five cases examined ultrastructurally, hexagonal virus particles were found in intact nuclei (average size = 68.9 nm, n = 89), associated with unbound condensed chromatin, and within vacuolated spaces in the cytoplasm (average size = 62.3 nm, n = 109). DNA in situ hybridization failed to detect adenovirus or polyomavirus nucleic acids. The presence of intralesional virus suggests that a causal relationship might exist between the virus and the proventricular lesions.

Combined NMR and computational study for azide binding to human manganese superoxide dismutase

Human manganese superoxide dismutase (MnSOD) labeled with 3-fluorotyrosine (Tyf) was complexed with the (15)N-labeled inhibitor azide ([(15)N(3)(-)]). The sample was characterized by solid-state NMR (SSNMR) spectroscopy ((19)F-MAS and (15)N-CPMAS). Employing (19)F-(15)N-REDOR spectroscopy, we determined the distances between the fluorine label in Tyrosine-34 and the three (15)N-nuclei of the azide and the relative orientation of the azide in the binding pocket of the MnSOD. A distance of R(1)=4.85A between the (19)F-label of Tyf34 and the nearest (15)N of the azide and an azide-fluorotyrosine Tyf34 angle of 90 degrees were determined. These geometry data are employed as input for molecular modeling of the location of the inhibitor in the active site of the enzyme. In the computations, several possible binding geometries of the azide near the Mn-complex were assumed. Only when the azide replaces the water ligand at the Mn-complex we obtained a geometry of the azide-Mn-complex, which is consistent with the present NMR data. This indicates that the water molecule ligating to the Mn-complex is removed and the azide is placed at this position. As a consequence the azide forms an H bond with Gln143 instead with Tyf34, in contrast to non-(19)F-labeled MnSOD, where the azide is hydrogen bonded to the hydroxy group of Tyr34.

Through-space MP-CPMAS experiments between spin-1/2 and half-integer quadrupolar nuclei in solid-state NMR

We present a new CPMAS method that allows the acquisition of through-space 2D HETCOR spectra between spin-1/2 nuclei and half-integer quadrupolar nuclei in the solid state. It uses rotor-synchronized selective pulses on the quadrupolar nucleus and continuous-wave RF irradiation on the spin-1/2 nucleus to create hetero-nuclear dipolar coherences. The method is more robust, more efficient, and easier to set up than the standard CPMAS transfer.

Solid-state NMR spectroscopy under periodic modulation by fast magic-angle sample spinning and pulses: a review

Fast magic-angle spinning (MAS) holds promise for new approaches to pulsed high-resolution NMR in solids where homogeneous interactions dominate. Prerequisite for developing new pulse methods is the understanding of signal encoding by spin interactions under MAS conditions and of interferences between MAS and pulses. This review discusses corresponding strategies and techniques in a coherent way with particular concentration on homonuclear decoupling techniques for line-narrowing in solids.

Gastrointestinal stromal tumors of the equine cecum

Ten cecal tumors were identified during the postmortem examination of seven horse carcasses at slaughter (one horse had three tumors). The multinodular and hemorrhagic tumors ranged from 1 to 10 cm in diameter and consisted of spindle cells arranged in thin, interconnected trabeculae that were often separated by sinuses filled with mucinous fluid, erythrocytes, and siderophages. Spindle cells of all tumors were immunopositive for vimentin, neuron-specific enolase, and c-kit protein but lacked reactivity with antibodies to glial fibrillary acidic protein, S100 protein, and desmin. In one tumor, spindle cells diffusely bound antibodies to synaptophysin. Most tumors contained focal reactivity to smooth muscle actin antibodies; one tumor reacted diffusely. Ultrastructurally, tumor cells were connected by desmosome-like structures and exhibited extended cell processes; some contained dense core neurosecretory granules. These equine stromal tumors appeared to share some characteristics with human gastrointestinal stromal tumors.

Analysis of multiple-pulse techniques under fast MAS conditions

The combination of magic-angle spinning and multiple-pulse sequences for line-narrowing in solids with homogeneous spin interactions is analyzed using Floquet theory. It is found that, for quasi-static conditions and for special synchronization conditions, line-narrowing is possible while for other conditions destructive interference of the two techniques takes place. However, even for optimum line-narrowing conditions, fundamental limitations with respect to the achievable linewidth are found, whereas the conditions of recoupling spin interactions are more easily realized. The implications of these results with respect to improving existing line-narrowing techniques or techniques for the design of specific Hamiltonians are discussed.

An evaluation of methods for the detection of spinal cord in product derived from advanced meat recovery systems

This study investigated the usefulness of immunohistochemistry, histochemistry, and polarization microscopy in documenting the presence of spinal cord in ground product produced by advanced meat recovery systems (AMRS). A battery of diagnostic stains proved most helpful for definitive documentation of spinal cord in the AMRS product. Antibodies to neurofilament and glial fibrillary acidic proteins were useful for highlighting the presence of neural tissue in comminuted product but when used alone did not definitively differentiate central nervous system tissue from peripheral nerve. Polariscopy, trichrome staining, and immunostaining for synaptophysin were very useful for differentiating spinal cord from peripheral nerve. Spinal cord was found in 2 of 196 AMRS samples when only hematoxylin and eosin staining was used. In a later immunohistochemical subset of the survey study, spinal cord was found in 7 of 17 AMRS samples. More recently, spinal cord tissue has been found in 3 of 26 regulatory samples using hematoxylin and eosin stains combined with immunohistochemical techniques.

Multi-centric histiocytosis: Experimental induction in broiler and specific pathogen-free leghorn chickens

Seventy-five 3-day-old broiler chicks and twenty specific pathogen-free leghorn chicks were injected with 0.5 ml of a homogenate, prepared from organs from broilers diagnosed with naturally-occurring multicentric histiocytosis (MH). Equal numbers of uninjected broiler and leghorn chicks (controls) were maintained in adjacent pens. Ten weeks later, nine broilers had well-developed gross and microscopic MH lesions. The distribution and histological appearance of lesions in these experimental chicks was similar to lesions described in naturally occurring field cases. Six leghorns had gross lesions similar to those found in their broiler counterparts; however, in the leghorns, the cellular masses contained more lymphocytes and, additionally, masses were found in the gizzard musculature. One gizzard contained a sarcoma. Broiler chickens with MH weighed less than their control counterparts and were more likely to be anaemic. Sequences specific for reticuloendotheliosis viruses (REV) were found in the MH homogenate, in organs from most affected experimental leghorns and broilers, and in organs from a control broiler. However, REV were not isolated from these tissues, nor were specific antibodies for REV or avian leukosis/sarcoma viruses (ALV) found in chick serum. Leukosis/sarcoma viruses were isolated from some MH-affected experimental leghorns and broilers. Sequences specific for Marek's disease herpesvirus were not identified by polymerase chain reaction. The aetiology of MH remains unknown.

Pulmonary sarcomas in a young chicken

Both lungs of a 5-wk-old broiler chicken contained miliary, round, white tumors. Microscopically, these masses were composed of compactly arranged cells with round to oval nuclei and indistinct cytoplasmic borders. Immunohistochemically, tumor cells were positive for vimentin but negative for cytokeratin, S-100 protein, neuron-specific enolase, smooth muscle actin, and muscle-specific actin. Ultrastructurally, tumor cells were separated by collagen bands and some contained collagen fibrils. These results suggest that the primitive mesenchymal cells composing these sarcomas may have originated from precursors of interstitial cells or fibroblasts of the interparabronchial or interatrial septa. DNA was extracted from paraffin-embedded tissues and probed for sequences specific for Marek's disease virus, reticuloendotheliosis viruses, exogenous avian leukosis viruses, and subgroup J avian leukosis viruses. Only sequences specific for subgroup J avian leukosis viruses were identified in the DNA extracted from tumors and surrounding lung.

Pulsed field gradient selection in two-dimensional magic angle spinning NMR spectroscopy of dipolar solids

The utility of gradient selection in MAS spectroscopy of dipolar solids is explored in two examples. In the first, rotor-synchronized gradients of appropriate strength and duration are applied to select 1H double-quantum coherences. The resulting DQ MAS spectrum of adamantane is compared with that acquired by the corresponding phase-cycling technique. As a second example, a 1H 2D exchange MAS experiment is performed on an elastomer sample. In this experiment, a gradient is applied to remove undesired coherences that would otherwise distort the spectrum for short mixing times. The diagonal-peak intensities in the resulting spectrum show a linear decrease with increasing mixing time indicating cross-relaxation by slow chain motions as the relevant process. Both types of experiments demonstrate the potential of gradient-selection techniques for MAS spectroscopy of dipolar solids. Copyright 1998 Academic Press.

Selective residual dipolar couplings in cross-linked elastomers by 1H double-quantum NMR spectroscopy

1H double-quantum (DQ) solid-state NMR spectroscopy under fast magic-angle spinning (MAS) is introduced as a new spectroscopic tool for the investigation of the structure and local chain dynamics of elastomers. Dipolar connectivities between the protons of the various functional groups can be directly established from the highly resolved DQ solid-state NMR spectra as is shown for a series of cross-linked poly(styrene-co-butadiene). More quantitatively, residual dipolar couplings within and between the functional groups are evaluated selectively from the build-up curves of the double-quantum signals in the limit of the spin-pair approximation. In particular, the CH-CH and the CH2-CH couplings of butadiene, which both act predominantly along the chain-segment direction, have been measured relative to the CH2 coupling. The total build-up intensity is correlated with the cross-link density.

Resolution enhancement in multiple-quantum MAS NMR spectroscopy

Two techniques for resolution and sensitivity enhancement are introduced in multiple-quantum (MQ) MAS spectroscopy of rigid solids. The first makes use of ultrafast MAS with spinning frequencies of up to 35 kHz, while the second combines MAS at moderately fast spinning frequencies of about 13 kHz with multiple-pulse (MP) dipolar decoupling. For the latter approach, a semiwindowless WHH-4 sequence is applied during the MQ evolution period (MQ dimension) and/or detection period (single-quantum dimension). In the MQ dimension, the MP sequence has to be supplemented by two bracketing pulses in order to preserve the order and the intensities of the evolving MQ coherences. Double-quantum 1H NMR spectra of l-alanine recorded using both decoupling techniques are shown and compared to each other. Triple-quantum 1H NMR spectra under ultrafast MAS conditions are also presented.

[Efficient ambulatory and post-discharge thromboprophylaxis with fully automated pens]

Efficient prophylaxis of deep vein thrombosis is very important during and after hospitalisation as well as for outpatients. In a prospective randomised trial, a new automatic pen for subcutaneous injections of low molecular heparin was studied with 489 injections in 51 patients. The automatic pen with a covered needle allows a safe and standardised subcutaneous administration of low-molecular heparin with good patient comfort and at no additional costs.

Malignant chromatophoroma in a canebrake rattlesnake (Crotalus horridus atricaudatus)

An adult female canebrake rattlesnake (Crotalus horridus atricaudatus) at Zoo Atlanta (Atlanta, Georgia, USA) had a subcutaneous mass on the left lateral abdomen. Microscopically, the tumor contained a pleomorphic population of cells with abundant intracytoplasmic brown to gold nonrefractile pigment (chromatophores), large stellate cells resembling neurons, and small stellate cells whose cytoplasmic processes formed a fibrillar matrix. The pigment stained black with the Fontana-Masson technique and was positive with the periodic acid-Schiff technique (prior to and after diastase treatment). Neuron-specific enolase was detected in the large stellate cells using an immunohistochemical staining technique. In addition, glial fibrillary acidic and S-100 proteins were detected in the chromatophores with immunohistochemical staining. The smaller stellate cells were strongly S-100 positive. Ultrastructurally, chromatophores contained intracytoplasmic structures composed of concentric lamellar membranes bordered by a triple-layer outer membrane. The morphology of these structures was compatible with pterinosomes. Three fluorescent pigments were isolated from the neoplasm by one-dimensional chromatography and characterized by spectrophotometry and spectrofluorometry.

Multiple-pulse assisted line-narrowing by fast magic-angle spinning

Combined rotation and multiple-pulse experiments (CRAMPS) are reported that are performed under the conditions of fast magic-angle spinning. Quasi-static conditions, as are required for CRAMPS experiments, can be fulfilled approximately also for fast sample spinning conditions when windowless or semiwindowless sequences are applied. In order to allow direct detection for these cases also, appropriately timed detection windows are introduced without loss of resolution. In contrast to conventional CRAMPS experiments, high-speed MAS was found to play an important role also in the averaging of residual dipolar contributions. The resolution achieved in these first experiments is comparable to that of conventional CRAMPS experiments and the demands with respect to spectrometer hardware and tuning are much lower.

Investigation of aging in polymer networks by T1 rho material property NMR imaging

Material property (MAP) imaging was found to be a promising method for the investigation of aging processes in elastomer materials. Based on conventional parameter-selective imaging, MAP imaging directly reveals the properties of the material by use of a theoretical description to relate the measured nuclear magnetic resonance data--in this investigation, T1 rho values--with the properties of the material. Following this concept, T1 rho images with different strengths of lock amplitude have been acquired for a rubber sample consisting of four pieces of natural rubber that were oxidatively aged under different conditions. The data were analyzed using a defect-diffusion model and transformed into images of those material parameters, which were found to be suitable for the characterization of the aging process. Images correlating with the crosslink density and the power law of T1 rho dispersion were obtained indicating the degree of aging.

Magic echoes and NMR imaging of solids

Solid state NMR imaging techniques based on magic echoes are reviewed. The theoretical background of magic echoes in general and their spatial encoding in particular is treated. The magic-echo imaging pulse sequences presently in use are described and discussed. Particular emphasis is devoted to those techniques, which allow the incorporation of spectroscopic or parameter-selective information. The applicability of these methods for the investigation of materials is demonstrated and perspectives for materials science are outlined.

Multicentric histiocytosis in young chickens. Gross and light microscopic pathology

During 1991-94, tissue specimens from 262 young chicken carcasses condemned at slaughter contained novel multicentric proliferations of histiocytelike cells. These tissues had been submitted to the USDA FSIS Eastern Laboratory because of grossly enlarged spleens, livers, or kidneys. The spleens were two to three times normal diameter and contained miliary white or yellow 1-3-mm foci. Similar miliary foci were present throughout the enlarged livers and kidneys. Microscopic examination of these tissues revealed discrete circular nodules expanding splenic periarteriolar lymphoid sheaths, hepatic periportal nodules, and discrete perivascular and more diffuse interstitial nodules replacing renal tubules. Nodules also were present in the pancreas, bone marrow, proventriculus, and lung, with more diffuse infiltrates in intestinal lamina propria. The cells composing these nodules contained irregularly oval, folded, or pleomorphic nuclei and relatively abundant eosinophilic cytoplasm. Mitotic figures and pyknotic nuclei were common. These cells were interpreted to be histiocytes (tissue macrophages or dendritic cells) and did not resemble lymphocytes. These proliferating cells also did not resemble the cell population of commonly diagnosed lymphoid neoplasms of young chickens. No intralesional organisms were detected and polymerase chain reaction analysis failed to detect Marek's herpesvirus DNA or leukosis/sarcoma and reticuloendotheliosis proviral DNA.

Malignant melanocytic neural crest tumor in a young chicken (Gallus domesticus)

A malignant melanocytic tumor was found in an 8-week-old chicken. The tumor, which was composed of melanocytes, ganglion cells, nerves, and primitive pressure receptors, was examined by light microscopy, transmission electron microscopy, and immunohistochemistry. Antibodies to neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), and S-100 protein variably stained nerves, but melanocytes were only rarely immunolabelled by NSE antibodies and there was no specific staining of these cells for S-100 or GFAP. Ultrastructurally, neoplastic melanocytes contained melanin within melanosomes and premelanosomes and did not resemble Schwann cells.

Spontaneous equine pulmonary granular cell tumors: morphologic, histochemical, and immunohistochemical characterization

Spontaneous equine pulmonary granular cell tumors were diagnosed in six mature horses at slaughter. These tumors were grossly recognized as multiple (5/6) or single (1/6) creamy white, firm nodules. The tumors, located adjacent to bronchi and bronchioles, often invaded airways, resulting in partial to complete occlusion of the lumina. Neoplastic cells were rounded to polyhedral with numerous eosinophilic cytoplasmic granules that reacted uniformly positive with S-100 and neuron-specific enolase antibodies and multifocally with glial fibrillary acidic protein antibodies. These cells were negative for muscle-specific actin, lysozyme, cytokeratin, chromogranin A, and myelin basic protein antigens and did not stain with silver by the Grimelius technique. Uniformly blue-green and scattered pink intracytoplasmic granules were evident with luxol fast blue and periodic acid-Schiff counterstain for myelin and myelin breakdown products. Histochemical and immunohistochemical staining results of these tumors suggest that they are composed primarily of myelinating Schwann cells with lesser numbers of scattered nonmyelinating Schwann cells. The morphologic features of the equine pulmonary granular cell tumors are strikingly similar to those of endobronchial granular cell tumors of human beings.

Magic-echo phase-encoding solid imaging with improved time resolution

The magic-echo phase-encoding solid imaging (MEPSI) sequence is based on the magic-echo pulse sequence for the refocusing of the dipolar interaction and on pure phase-encoding for spatial resolution in all dimensions. MEPSI has many advantages; however, as a consequence of pure phase-encoding, it is very time-consuming. In the following, two strategies are proposed to decrease the time necessary for the acquisition of an image by a factor of 2 per dimension.

Aging of polymer networks as studied by material property NMR imaging

Relaxation-weighted NMR imaging is a powerful tool for the investigation of aging processes in rubber networks, in particular if it is combined with a theoretical description to relate the NMR data with suitable parameters of the material. Following this concept, spin-spin relaxation decays in rubber samples, consisting of differently aged pieces of natural rubber have been acquired in a spatially resolved experiment. The data were evaluated using a dynamical model and transformed into images of those material properties, which are affected by the aging process. Images representing the crosslink density and the correlation times, which characterize the polymer chain dynamics, have been calculated. The differently aged rubber pieces can be easily discriminated in such material property (MAP) images.

Splenic granulomas in broiler chickens produced experimentally by inoculation with Eubacterium tortuosum

Eubacterium tortuosum, a gram-positive anaerobic filamentous bacillus, was isolated from splenic and hepatic granulomas of a 56-day-old slaughtered chicken. This isolate was injected intravenously into two groups of 2-week-old broiler chickens, which were necropsied 19 days later. Five of 15 chickens injected with 5 x 10(6) colony-forming units of a 48-hour culture of E. tortuosum developed splenic granulomas typical of those seen in chickens at slaughter. No lesions were observed in chickens given 5 x 10(5) colony-forming units of E. tortuosum or in control chickens receiving phosphate-buffered saline solution. Attempts to reisolate E. tortuosum from experimentally infected chickens were unsuccessful; however, typical filamentous organisms were observed in splenic granulomas of all five affected chickens.

NMR-imaging of water content in the polymer matrix of silicon chips

The distribution of water in the polymer matrix of a silicon microchip was studied by NMR imaging. The chip was saturated with water in a water steam atmosphere and then dried in five steps. After every change of the water content a three-dimensional (3D) NMR image was acquired. A 3D back-projection spin-echo sequence was used to avoid fast gradient switching during the sequence. The experiments show that water invades the chip mainly through the gap between the metallic parts and the polymer body.

Fast imaging in liquids and solids with the Back-projection Low Angle ShoT (BLAST) technique

A simple fast imaging scheme is proposed, which is applicable to solid- and liquid-like materials. It is based on low angle pulse excitation in combination with back-projection reconstruction and proper data handling and is called Back-projection Low Angle ShoT (BLAST) technique. The sequence is applied to grape as a biological sample and to a jellibaby (2 kHz linewidth at half intensity) for demonstration of the applicability to solid objects.