Biomedical subjects

M Stoltenberg

Publications and source records attributed to M Stoltenberg.

At least 37 records · Page 2Linked to original sources

PubMed2000

Bismuth autometallography: protocol, specificity, and differentiation.

We provide a detailed protocol of the autometallographic bismuth technique and evaluate the specificity of the technique. We show by the multi-element technique "proton-induced X-ray microanalysis" (PIXE) that the autometallographic grains contain silver, bismuth, and sulfur, proving that autometallography can be used for specific tracing of bismuth bound as bismuth sulfide clusters in tissue sections from Bi-exposed animals or humans. In sections from animals exposed concurrently to selenium and bismuth, the autometallographic grains also contain selenium. This demonstrates that, if present in excess in the organisms, selenium will bind to exogenous bismuth, creating bismuth selenide clusters. As a further possible control for specificity and as a tool for differentiating among autometallographically detectable metals in sections containing more than one, we describe how bismuth sulfide clusters can be removed from Epon-embedded tissue sections by potassium cyanide.

Animals↗

PubMed1999

Magnetic resonance imaging-determined synovial membrane volume as a marker of disease activity and a predictor of progressive joint destruction in the wrists of patients with rheumatoid arthritis.

OBJECTIVE: To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). METHODS: Twenty-six patients with RA, randomized to receive disease-modifying antirheumatic drug (DMARD) therapy alone (11 patients) or DMARDs in combination with oral prednisolone (15 patients), were followed up for 1 year with contrast-enhanced MRI of the dominant wrist (months 0, 3, 6, and 12), conventional radiography (months 0 and 12), and clinical and biochemical examinations. Bone erosion (by MRI and radiography) and synovial membrane volumes (by MRI) were assessed. RESULTS: Significant synovial membrane volume reductions were observed after 3 and 6 months in the DMARD + prednisolone group, and after 6 and 12 months in the DMARD-alone group (P < 0.01-0.02, by Wilcoxon-Pratt analysis). The rate of erosive progression on MRI was highly correlated with baseline scores and, particularly, with area under the curve (AUC) values of synovial membrane volume (Spearman's sigma = 0.69, P < 0.001), but not with baseline or AUC values of local or global clinical or biochemical parameters, or with prednisolone treatment. In none of 5 wrists with baseline volumes <5 cm3, but in 8 of 10 wrists with baseline volumes > or =10 cm3, erosive progression was found by MRI and/or radiography, indicating a predictive value of synovial membrane volumes. MRI was more sensitive than radiography for the detection of progressive bone destruction (22 versus 12 new bone erosions). CONCLUSION: MRI-determined synovial membrane volumes are closely related to the rate of progressive joint destruction. Quantitative MRI assessment of synovitis may prove valuable as a marker of joint disease activity and a predictor of progressive joint destruction in RA.

Administration, Oral↗

PubMed1999

YKL-40 in giant cells and macrophages from patients with giant cell arteritis.

OBJECTIVE: YKL-40, a mammalian member of the family 18 glycosyl hydrolases, is secreted by activated macrophages at a late stage of differentiation. Macrophages are present in inflammation of the arterial wall and are thought to participate in the pathogenesis of giant cell arteritis (GCA). The aim of this study was to evaluate whether macrophages and giant cells of patients with GCA produce YKL-40, and whether serum YKL-40 concentrations are elevated in these patients. METHODS: Serum YKL-40 was determined by radioimmunoassay in 19 patients with GCA and 8 patients with polymyalgia rheumatica (PMR) who were followed up prospectively during 1 year of treatment with prednisolone. Immunohistochemical staining for YKL-40 was performed in temporal artery biopsy samples that were obtained before treatment. RESULTS: In the arteritic vessels of patients with GCA, positive staining for the YKL-40 antigen was found in CD68+ giant cells and mononuclear cells located in the media. Macrophages located in the adventitia and intima were negative for YKL-40. At the time of diagnosis, patients with GCA had an increased median serum level of YKL-40 (256 microg/liter; P<0.01) compared with healthy age-matched controls (median 118 microg/liter), and the serum level of YKL-40 decreased to normal levels during prednisolone treatment (-38% after 1 month; P<0.001). Most patients with PMR had normal serum YKL-40 levels (median 158 microg/liter) and had no changes in the serum YKL-40 levels during prednisolone treatment. The observed changes in serum YKL-40 did not always parallel the changes in serum C-reactive protein levels and erythrocyte sedimentation rate during the 1-year study period. CONCLUSION: YKL-40 is found in CD68+ giant cells and mononuclear cells in the media of arteritic vessels of patients with GCA, and the concentration of serum YKL-40 may reflect the local activity of these cells in the inflamed artery.

Adipokines↗

PubMed1999

Zinc, magnesium and calcium in human seminal fluid: relations to other semen parameters and fertility.

The effects of zinc, magnesium and calcium in seminal plasma on time-to-pregnancy (TTP) in healthy couples, on conventional semen parameters and computer-assisted semen analysis (CASA) parameters were evaluated. The localization of chelatable zinc ions in seminal plasma and spermatozoa were assessed by autometallography (AMG). Differences in chelatable zinc localization in samples with high and low total zinc were evaluated. Semen samples from 25 couples with short TTP and 25 couples with long TTP were subjected to conventional semen analysis, CASA, zinc and magnesium measurements by inductively coupled plasma mass spectrometry, and calcium by flame atomic absorption spectrometry. The cations were strongly inter-correlated, but no correlation with TTP or conventional semen parameters was found. Semen samples with high zinc concentrations exhibited statistically significant poorer motility assessed by the CASA parameters straight line velocity and linearity than samples with low zinc content. Calcium concentration also showed statistically significant differences for the same parameters, but the effect was removed by entering zinc concentration into a multiple regression model. Semen samples with high total zinc exhibited stronger staining of the seminal plasma at AMG. It is suggested that high seminal zinc concentrations have a suppressing effect on progressive motility of the spermatozoa ('quality of movement'), but not on percentage of motile spermatozoa ('quantity of movement').

Adult↗

PubMed1999

Chelation of intracellular zinc ions affects human sperm cell motility.

The effects of two different zinc chelators, diethyldithiocarbamate (DEDTC) and calcium ethylenediaminetetraacetic acid (EDTA), in full semen samples and 'swim-up' samples were investigated. DEDTC, which crosses cell membranes, and EDTA, which does not cross cell membranes, were added to semen samples in different concentrations. Sperm cell motility parameters were assessed by computer-assisted semen analysis (CASA). It was found that very small concentrations (0.01 mM) of DEDTC immobilized the sperm cells within 80 min, while EDTA had no depressing effect at the concentrations used. In full semen samples EDTA enhanced straight line velocity (VSL) at concentrations of 1.0 and 0.5 mM; this effect was not found at higher concentrations. It is suggested that intracellular mitochondrial zinc ions play a crucial role for sperm cell motility, while loosely bound or free zinc ions in the seminal plasma exert a secondary role on human sperm cell motility.

Adult↗

PubMed1999

Serum YKL-40 concentrations in patients with rheumatoid arthritis: relation to disease activity.

OBJECTIVE: YKL-40, also called human cartilage glycoprotein-39, is secreted by chondrocytes, synovial cells, macrophages and neutrophils. Studies have shown that YKL-40 is an autoantigen in rheumatoid arthritis (RA). We evaluated whether serum YKL-40 was related to disease activity in patients with RA. METHODS: Serum YKL-40 was determined by radioimmunoassay in 156 patients with RA during a 1 yr longitudinal study. RESULTS: Serum YKL-40 was increased in 54% of the patients with clinically active disease. Patients with clinically active disease initially who became inactive after 12 months had a significant decrease in serum YKL-40 (-30%, P < 0.002) and patients who changed from inactive to active disease had an increase in serum YKL-40. Patients who remained active had unchanged serum YKL-40 during the study. Serum YKL-40 decreased rapidly (-24% after 7 days, P < 0.01) during prednisolone therapy, and more slowly in patients treated with methotrexate only (-15% after 60 days, P < 0.01). Patients with early RA (disease duration < 3 yr, n = 50) and a persistently elevated serum YKL-40 were at risk of radiological disease progression as determined by Larsen score. CONCLUSION: Serum YKL-40 varies according to disease activity in RA, but provides in some respect information different from conventional markers. Our previous studies are consistent with a local release of YKL-40 in the arthritic joint followed by a secondary increase in serum YKL-40. YKL-40 may prove to be a new tool for the study of disease activity and pathophysiology of RA.

Adipokines↗

PubMed1999

A randomised trial of differentiated prednisolone treatment in active rheumatoid arthritis. Clinical benefits and skeletal side effects.

OBJECTIVES: To study benefits and skeletal side effects of carefully monitored prednisolone treatment in patients with active rheumatoid arthritis. METHODS: One hundred and two patients with active rheumatoid arthritis were randomly allocated to treatment with disease modifying anti-inflammatory drug (DMARD) alone or DMARD and prednisolone in a one year follow up study. Prednisolone was given in a dose regimen adapted to the disease activity of the individual patient. The mean dose was 6 mg and the mean cumulated dose was 2160 mg. Patients were followed up with disease activity parameters, radiograph of the hands (Larsen score), and bone mineral density (BMD) of the lumbar spine, distal forearm and hand. At one year 26 patients had withdrawn from the investigation leaving 76 patients for evaluation. RESULTS: The results showed that disease activity in the prednisolone treated group was reduced within two weeks. In the DMARD alone group disease activity was gradually reduced over months. At six months there was no difference between the groups as evaluated by an improvement score using a number of ACR criteria. Prednisolone in the present set up was not able to protect significantly against radiological disease progression, although there was a trend towards less progression in Larsen score in the prednisolone group, a matter that was further underlined in an intention to treat analysis. BMD data revealed a significant reduction in spinal BMD in the prednisolone group, whereas prednisolone seemed to have a protective effect against bone loss in the hand and distal forearm. CONCLUSIONS: This study does not allow any firm conclusions for or against the treatment of rheumatoid arthritis with prednisolone. The data suggest that the beneficial effects of prednisolone are not as clear cut in established rheumatoid arthritis as in early disease. Furthermore the data indicate that treatment in the chosen relatively low dose does not provide sufficient control of disease. On the other hand the spinal bone loss observed in the prednisolone group does invite considerations about using higher doses.

Adult↗

PubMed1998

Quantification of synovistis by MRI: correlation between dynamic and static gadolinium-enhanced magnetic resonance imaging and microscopic and macroscopic signs of synovial inflammation.

Dynamic and static gadolinium-diethylenetriaminepentaacetic acid(Gd-DTPA)-enhanced magnetic resonance imaging (MRI) were evaluated as measures of joint inflammation in arthritis, by a comparison with macroscopic and microscopic signs of synovitis. Furthermore, the importance of the size of the evaluated synovial areas was investigated, as was the optimal time for enhancement measurements. Seventeen rheumatoid arthritis knees and 25 osteoarthritis knees, scheduled for arthroscopy or arthrotomy, were included. Macroscopic and microscopic synovial inflammation as well as nine histologic tissue characteristics were graded at four preselected biopsy sites. Preoperative T1-weighted dynamic fast low angle shot and static spin-echo Gd-enhanced MRI were performed. The dynamic enhancement rate and the static enhancement were measured in the entire synovial membrane of a preselected slice as well as at the four biopsy sites, and compared to synovial pathology. The rate of early enhancement of the total synovial membrane of the preselected slice, determined by dynamic MRI, was highly correlated with microscopic evidence of active inflammation (Spearman p = 0.73; p < 10(-7). Dynamic MRI could distinguish knees with and without synovial inflammation with a high predictive value (0.81-0.90). Moderate and severe inflammation could not be differentiated. The early enhancement rate was correlated with histologic features of active inflammation, particularly vessel proliferation and mononuclear leucocyte infiltration. Dynamic evaluation of small synovial sections at the biopsy sites and static spin-echo MRI resulted in considerably weaker correlations to histologic inflammation than dynamic evaluation of the total synovium. The optimal time for enhancement measurements was one-half to one minute after Gd injection, as the highest correlation coefficients to histologic inflammation were observed in this interval. Dynamic MRI can be used to determine synovial inflammation. Evaluation of large synovial areas one-half to one minute after Gd injection best reflects joint inflammation.

Adult↗

PubMed1998

Computer-assisted visualization of the rat epididymis: a methodological study based on paraffin sections autometallographically stained for zinc ions.

A concept for the computer-assisted visualization of tubular organs is presented. Unmarked histological zinc-stained serial sections from the epididymis of the Wistar rat were aligned to demonstrate the concept. Virtual images were made through the aligned sections and served as controls for the alignment process. Animation of the serial sections and the virtual images revealed new information about the structure of the organ under investigation. The analysis was used to upgrade the anatomical knowledge of rat epididymis by describing how the epididymal duct runs through the structure. The proximal parts of the epididymis contain large communicating septa of connective tissue dividing the caput and the upper part of the corpus epididymidis into segments. The tortuousness was high in the caput with many turns within a small area of the epididymis, whereas longer loops were found in the lower part of the corpus and cauda epididymidis. The tube of the vas deferens was found to become an integrated part of the ductal system in the cauda epididymidis, although it was histologically easy to distinguish from the epididymal duct. The total number of cross-sections of the ductus epididymidis in the 2254, 15-microm-thick, tissue sections analysed was 104700, giving a minimum length of the ductal system of 1.5 m.

Animals↗

PubMed1998

Histochemical tracing of zinc ions in the rat testis.

To detect free zinc ions in the rat testes four rats were transcardially perfused with Na2S, and the seminiferous tubules from two other rats were incubated in Na2S. Sections from the two sources were autometallographically (AMG) developed, whereby zinc sulphide crystal lattices created in the tissue by the sulphide treatment were silver enhanced. Light microscopical analysis showed zinc ions in primary spermatogonia until the zygotene primary spermatocytes (stage I), in late pachytene spermatocytes (stages XII and XIII), and in late spermatids from step 15 to step 19 (stages I-VIII). The highest intensity of AMG grains was detected in the residual bodies and tails of step 19 spermatids. Grains were occasionally found in the cytoplasm of Leydig cells. Sections from animals treated with the chelator diethyldithiocarbamate prior to sulphide treatment showed a complete lack of AMG staining. At ultrastructural levels the AMG grains were found in smooth-surfaced endoplasmic reticulum of all spermatogonial stages, and in the acrosome, midpiece, and tail of late spermatids. The presence of zinc ions in preleptotene spermatocytes and cytoplasmic lobes of late spermatids suggests a specific role of free zinc at the onset of meiosis and at spermiation.

Animals↗

PubMed1997

Increased amount of zinc in the hippocampus and amygdala of Alzheimer's diseased brains: a proton-induced X-ray emission spectroscopic analysis of cryostat sections from autopsy material.

Zinc has been implicated as a contributing cause of the neuropathology of Alzheimer's disease (AD), but consensus on the zinc content of AD brains has not yet been established. In the present study, multi-element PIXE was used to measure zinc in cryostat sections of brain tissue from AD patients and from normal control subjects. Compared to their age-matched controls, the AD patients showed an increase in zinc in the hippocampal and amygdalar regions. The instrumental PIXE assays do not show whether the zinc changes are due to altered zinc in the boutons of Zinc-ENriched (ZEN) neurons, i.e., zinc ions in synaptic vesicles, or to changes in the amount of zinc tightly bound to macromolecules. We hypothesise that the increased zinc level is caused by an increase in the amount of ZEN terminals. Such an increase could be the result of a sprout of ZEN terminals in diseased areas of the brain.

Aged↗

PubMed1997

Ultrastructural localization of zinc ions in the rat prostate: an autometallographic study.

BACKGROUND: The prostate contains high amounts of free zinc ions which are excreted into the seminal fluid. The extra- and intracellular distribution of zinc ions using the highly specific autometallographical (AMG) method is described. METHODS: Prostates from sulfide-perfused rats were excised, and the ZnS crystals were silver-enhanced to sizes detectable by the electron and light microscope. RESULTS: AMGZnS grains were found primarily in the acinic lumen of the lateral lobes. The dorsal lobe stained only faintly, while the ventral lobe was void of grains. At ultrastructural levels, the presence of zinc ions was confined to apical secretory vesicles and lysosome-like structure of the epithelium of mainly the lateral lobes. CONCLUSIONS: We suggest a constant secretion of zinc ions from the epithelial cells into both the acinar lumen and the intercellular canaliculi, and that the zinc enriched secretory cells in the prostate belong to a system of glandular cells that uses zinc ions to aggregate macromolecules to be excreted.

Animals↗

PubMed1997

Magnetic resonance imaging-determined synovial membrane and joint effusion volumes in rheumatoid arthritis and osteoarthritis: comparison with the macroscopic and microscopic appearance of the synovium.

OBJECTIVE: To evaluate the relationship between synovial membrane and joint effusion volumes determined by magnetic resonance imaging (MRI) and macroscopic and microscopic synovial pathologic findings in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: Synovial biopsies were performed, and macroscopic grades of synovitis assigned, at preselected knee sites during arthroscopy or arthrotomy in 17 knees with RA and 25 with OA. Synovial inflammation and 9 separate tissue characteristics were graded histologically. Synovial membrane and joint effusion volumes were determined by preoperative MRI, enhanced with intravenous gadopentetate dimeglumine. RESULTS: MRI-determined synovial membrane volumes were correlated with the overall histologic assessment of synovial inflammation (Spearman's sigma = 0.55, P < 0.001), with fibrin deposition, with subsynovial mononuclear and polymorphonuclear leukocyte infiltration (sigma = 0.51-0.59), and less significantly with macroscopic synovitis, vessel proliferation, and granulation tissue formation (sigma = 0.40-0.42). No correlation with synovial lining multiplication, perivascular edema, villous formation, or fibrosis was found (sigma < 0.30). CONCLUSION: MRI-determined synovial volumes are correlated with synovial inflammatory activity. Synovial volumes probably mainly reflect the mass of cell-infiltrated, vascularized subsynovial tissue, but may also be influenced by the cumulative synovial proliferative activity. MRI-determined synovial membrane and effusion volumes may be sensitive markers and/or predictors of disease activity and treatment outcome in RA.

Adult↗

PubMed1997

Distinct differences in partial oxygen pressure at micrometer ranges in the rat hippocampal region.

A mapping at micrometer ranges of the partial oxygen pressure in the rat hippocampus was performed. The oxygen tension in the rat hippocampal region was measured using a glass oxygen microsensor in 30-microm steps along straight lines at a set of stereotactic coordinates. In the hippocampus the pattern of the oxygen tensions reflected the autometallographic zinc sulphide (AMG(ZnS)) pattern, i.e. the pattern of zinc enriched (ZEN) terminals. The highest levels of oxygen tension were recorded in the areas that are most heavily stained with the autometallographic zinc sulphide (AMG(ZnS)) method, like hilus fasciae dentatae. The zinc ions located in synaptic vesicles of the ZEN terminals can also be demonstrated by AMG silver amplification in brains from animals in vivo treated with sodium selenite. This method depends on the presence of a substantial reduction capacity of the tissues as selenite ions (SeO(2)(3)-) must to be reduced to selenide ions (Se2-) before the catalytic zinc selenide crystals can be formed. At some point, either during the transport from the infusion site to the actual target tissue or in the target tissue itself, selenium is reduced from Se(+ IV) to Se(- II). The importance of the reduction capacity of the target tissue in this process is demonstrated by the fact that areas found to have the highest concentration of zinc ions, e.g. hilus fasciae dentatae and the mossy fibres of CA3, are almost unstained after 1 h of i.p. Na2SeO3 exposure. An explanation of this phenomenon could be that the reduction process Se(+ IV) <==> Se(- II) leading to the formation of Se2- is moved to the left by the presence of oxygen, thus inhibiting the precipitation of ZnSe crystals. It is suggested that the subtle oxygen pressure pattern found in the rat hippocampus might also reflect essential biological zinc-related mechanisms vital to brain function.

Animals↗

PubMed1997

Histochemical demonstration of zinc ions in human epididymis using autometallography.

A recently described autometallographic technique, allowing demonstration of chelatable zinc in human biopsy material, was applied to cryostat sections from biopsies of human epididymis. Sections from the rat epididymis were used as control materials to examine the quality of the method compared with a previously used autometallographic method. The human epididymis exhibits heavy staining in the head of the epididymis and only small amounts of zinc in the body and tail of the organ. The zinc staining was found in the apical part of the ciliated cells and in the lumen. The present technique can be used to localize zinc ions at ultrastructural levels. Zinc grains were localized in lysosome-like bodies and secretory granules of the ciliated cells. The luminal staining was present as free, evenly dispersed zinc grains or attached to sperm cells and stereocilia in the lumen. The large differences in staining patterns along the epididymal tract in humans and rats suggest that zinc ions are important for the maturation of sperm cells.

Biopsy↗

PubMed1997

Histochemical demonstration of zinc ions in ejaculated human semen.

A revised in-vitro technique for autometallographic demonstration of chelatable zinc in the human ejaculate is presented, and the localization of the loosely bound pool of zinc ions is described in semen smears and at the ultrastructural level. In semen smears, black autometallographic (AMG) grains indicated the presence of zinc ions dispersed between the spermatozoa. These AMG grains have the same size as grains associated with the sperm tail and may have the same origin. EM analysis of AMG-developed smears fixed in osmium suggested that the detected zinc ions might be related to huge protein molecules present in semen and adhering to the surface of the spermatozoa. Spermatozoa in AMG-stained smears exhibited zinc ions in the midpiece and head, and also joined to the membrane of the tail. Washed spermatozoa exhibited zinc ions only within the midpiece. Ultrastructurally, they were found located in the helecine mitochondria. A few grains were found in the acrosome of the washed spermatozoa. Treatment with the chelating agent DEDTC resulted in complete bleaching of the zinc staining. These findings and the fact that calcium EDTA acid blocks the plasma and surface staining, but not the acrosomal and mitochondrial staining, suggest that chelatable zinc ions exist in two separate pools in human semen.

Adult↗

PubMed1997

Autometallographic demonstration of zinc ions in rat sperm cells.

An in-vitro technique for autometallographic (AMG) demonstration of chelatable zinc in electroejaculated sperm cells and spermatozoa from the epididymis is presented and the localization of zinc ions in rat spermatozoa is described. Sperm cells from caput epididymis showed zinc staining in all parts of the tail and a sparse, dispersed staining in the acrosome. Spermatozoa from cauda epididymis showed heavy staining in the acrosome but no staining in the tail, or post-acrosomal part of the sperm head. This distinct acrosomal AMG staining was also found in ejaculated spermatozoa, but additionally a segmentation of the tail was seen based on differences in staining intensity. The membrane penetrating chelator diethyldithiocarbamate (DEDTC) was found to block the AMG staining whereas calcium-EDTA, known not to pass through cell membranes, did not influence the staining, proving that the detected zinc ions are intracellularly located. Two different approaches for demonstrating the presence of a chelatable zinc pool at electron microscope levels are presented, and the ultrastructural presence of AMG grains located in the acrosome and in the mitochondria of the midpiece is demonstrated. It is postulated that an exchange of zinc ions takes place between the epididymal epithelium and the sperm cells as they pass along the epididymal duct.

Acrosome↗

PubMed1997

Autometallographic silver enhancement of zinc sulfide crystals created in cryostat sections from human brain biopsies: a new technique that makes it feasible to demonstrate zinc ions in tissue sections from biopsies and early autopsy material.

We present a new technique that allows zinc ions in synaptic and secretory vesicles of biopsy and early autopsy material (< 2 hr post mortem) to be transformed to nanometer-sized zinc sulfide crystal lattices for subsequent autometallographic (AMG) development. Human brain biopsies, or other tissue samples containing zinc-enriched (ZEN) cells, are frozen in liquid nitrogen or by CO2 gas immediately after removal. The tissue blocks are cut in a cryostat and the sections placed on glass slides. The slides are transferred to an H2S exposure chamber placed in a -15 C freezer. After 1-24 hr of gas exposure the sections are removed from the chamber, fixed while thawing, and dehydrated. The sections are then exposed to an AMG developer. AMG causes silver enhancement of zinc sulfide crystal lattices created in the tissues through the H2S exposure, making them visible. It is imperative that the tissues are frozen instantaneously after removal, because loosely bound or free zinc ions start leaving their vesicular compartment soon after death. The AMG technique can, despite inadequate fixation and damage to the tissue caused by freezing, also be used to trace zinc ions at ultrastructural levels, and it is demonstrated that zinc ions in the human neocortex are located in synaptic vesicles. In the few human biopsies analyzed thus far, the light microscopic pattern created by the silver-enhanced ZEN terminals resembles that seen in the neocortex of rat brain. The technique has been applied to cryostat sections from neocortex biopsies of five individuals undergoing brain surgery. Biopsies from three patients resulted in satisfactory AMG-stained sections. Rat brains removed and frozen immediately after decapitation constituted the material on which the present technique was developed. Such material results in an almost uniform high quality of staining, and we found that unexposed sections can be stored for at least 5 months at -80 C without ensuing significant loss of AMG staining intensity.

Animals↗