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The aim of the study was to define possible differences between selenite, selenate and selenium yeast on various aspects of selenium status in growing cattle. Twenty-four Swedish Red and White dairy heifers were fed no supplementary selenium for 6 months. The basic diet contained 0.026 mg selenium/kg feed dry matter (DM). After the depletion period the animals were divided into 4 groups; group I–III received 2 mg additional selenium daily as sodium selenite, sodium selenate, and a selenium yeast product, respectively. Group IV, the control group, received no additional selenium. The total dietary selenium content for groups I–III during the supplementation period was 0.25 mg/kg DM. After the depletion period the mean concentration of selenium in blood (640 nmol/l) and plasma (299 nmol/l) and the activity of GSH-Px in erythrocytes (610 µkat/l) were marginal, but after 3 months of supplementation they were adequate in all 3 groups. The concentration of selenium in blood and plasma was significantly higher in group III than in groups I and II, but there was no significant difference between groups I and II. The activity of GSH-Px in erythrocytes did not differ between any of the supplemented groups. The animals in the control group had significantly lower concentrations of selenium in blood and plasma and lower activities of GSH-Px in erythrocytes than those in the supplemented groups. The activity of GSH-Px in platelets was also increased by the increased selenium intake. There was no difference in the concentration of triiodothyronine (T3) between any of the groups, but the concentration of thyroxine (T4) was significantly higher in the unsupplemented control group.

The amount and distribution of blood in the cerebrospinal fluid following subarachnoid hemorrhage can be monitored with CT. An investigation of 110 patients was performed retrospectively in 100 patients with a total of 132 CT examinations, and prospectively in 10 patients with 40 CT examinations. During the days following the hemorrhage, the blood was redistributed within the subarachnoid space and eventually reabsorbed. The blood in the basal cisterns was cleared first, whereas the amount of blood in the cortical sulci appeared to increase after a few days, later to be cleared. It is concluded that the redistribution of the blood reflects the circulation of the cerebrospinal fluid, and that the erythrocytes thus act as tracers of this circulation. The amount of blood within the ventricular system was correlated to the size of the ventricles; patients with large amounts of blood within the subarachnoid space had hydrocephalus more often than other patients.

Ten patients with findings at computed tomography (CT) suggesting intracranial supratentorial glioma were investigated to compare the diagnostic efficacy of this technique with that of positron emission tomography (PET) using 11C-methionine and exminations with magnetic resonance (MR). The findings were related to histopathologic examination of serial stereotactic biopsies, which were guided by the appearance of the lesions on PET examination. To obtain corresponding slice orientation with the different examination techniques, an individually shaped helmet fixation was used. However, in 3 cases this fixation device could not be used for MR. Histopathologic diagnosis, obtained in all cases from multiple target stereotactic biopsies, included glioma in 9 patients and reactive gliosis in one case. A detailed comparison of the three imaging techniques and the findings at stereotactic biopsies was possible in 7 patients, while in 3 patients comparison with MR was less exact due to the patient's refusal to wear the helmet during this examination. MR was the most accurate method for outlining the total extent of a lesion, i.e. the tumor and the edema surrounding it. Four lesions had homogeneous signal characteristics and in 6 lesions two (or more) compartments could be distinguished with MR. In 5 cases the MR findings were in complete agreement with the histopathologic findings. However, a thorough correlation between signal characteristics and histology was not possible. Using PET the occurrence and the extent of tumor tissue was correctly predicted in 7 patients. The PET was normal in one case. Findings at CT were in agreement with the histopathologic diagnosis in 5 patients. MR was the most sensitive method for the detection of lesions. PET using methionine appeared to have a somewhat higher capacity to outline correctly the true extent of a tumor. The combination of CT and PET was superior to MR for determining the type and grade of the tumors.

Summary Thirteen patients with expanding mass lesions underwent postoperative serial CT scanning after frontal lobe resection. Cases with malignant tumours and significant preoperative oedema showed a rapid postoperative filling of the resection cavity which presumably reflects increased intracranial pressure. Cases with more benign lesions without significant preoperative oedema continuously maintained an empty resection cavity. The results suggest that the clinical outcome after frontal lobe resection can be predicted from preoperative CT scans.

Summary Fifty (50) selected patients with arteriovenous malformation (AVM) with and without subarachnoid haemorrhage (SAH) were investigated, in respect of occurrence and course of the vasospasm. The diameters of the carotid siphon and its main branches were measured and plotted against the time elapsing between the haemorrhage and the angiographic study. Patients without SAH were used as a reference group. The results suggest intracranial arterial spasm to occur between the third and eleventh day after the onset of SAH. Patients with intracerebral haematoma may show vasospasm from the first day onwards. It seems that the radiologically demonstrated spasm in AVM had no impact on the clinical outcome in this series.

Summary To eliminate the occurrence of artefacts produced by clips on the CT images, the use of titanium clips is suggested. Testsin vitro andin vivo indicate that clips manufactured from 0.2 mm thick 99.9 per cent titanium do not cause artefacts. They are resistant to corrosion, nontoxic, effective, easy to handle, relatively cheap, and are visible on plain X-ray films.

Summary Eight patients with malignant gliomas verified on CT scan, received an intravenous injection of 50 mg of Adriamycin R, 24 hours prior to surgical removal of the tumour. Peroperatively, both tumour and surrounding tissue specimens were obtained for determination of the tissue concentrations of Adriamycin and its reduced metabolite Adriamycinol. It was found that Adriamycin could be detected in tumour tissue from all patients. The concentration varied between 0,9 and 4,6 nmol/g tissue. In contrast, Adriamycin could only be detected in surrounding brain tissue from one patient.

Glioma-associated gangliosides, in particular the expression of foetal gangliosides 3′-isoLM1 and 3′6′-isoLD1, have been investigated in biopsies from 44 patients with astrocytoma grade II, anaplastic astrocytoma, anaplastic oligodendrogliomas, oligodendrogliomas, and glioblastoma multiforme. The total ganglioside content decreased in proportion to the estimated number of tumour cells present in the biopsy. Ganglioside GD3 was increased in 17 of the tumour tissues and in 6 of the surrounding area specimens. In agreement with our previous studies, tumour specimens contained the lactoseries ganglioside 3′-isoLM1 and, as demonstrated for the first time, the disialylated form of the ganglioside, 3′6′-isoLD1. These gangliosides are in normal brain tissue restricted to the developmental period. Most frequent was the expression of ganglioside 3′-isoLM1 which was detected in 92% of the tumour specimens in concentrations varying between just detectable amounts to 13 nmol/g wet weight. In the area surrounding the macroscopic tumour tissue 78% of the specimens expressed 3′-isoLM1 and the values varied between just detectable amounts to 24 nmol/g wet weight. Ganglioside 3′6′-isoLD1 was found in 47% of the tumour biopsies and in only 17% of the specimens taken outside macroscopic tumour tissue. The values varied between non-detectable amounts to 40 nmol/g wet weight of tissue. The expression of 3′-isoLM1 correlated significantly (p<0.01) to malignancy grade. For 3′6′-isoLD1 a significant (p<0.05) difference was found between tomour and surrounding tissue. Likewise, 3′6′-isoLD1 correlated significantly (p<0.05) to malignancy grade. The correlation between 3′-isoLM1 and 3′6′-isoLD1 to malignancy grade and the frequent expression of these gangliosides both in the tumour itself and in its surrounding area should encourage additional studies concerning their biological role in tumour disease.

Increased metabolic activity represented by an increase in both anabolism and catabolism in tumours, including gliomas, is a well known phenomenon and utilised in positron emission tomography imaging of tumours. In this study lysosomal enzyme activities of some glycohydrolases were investigated in glioma tissue from human brain. Tumour tissue (ten cases) and brain tissue surrounding the tumour tissue (seven cases) from patients with a histopathological diagnosis of glioblastoma multiforme or anaplastic astrocytoma were analysed for activity of the lysosomal enzymes galactosylceramidase, glucosylceramidase, β-galactosidase, β-N-acetylglucosaminidase, β-glucuronidase, and acid phosphatase. All of the investigated lysosomal enzymes except galactosylceramidase showed increased activity compared with that in normal brain tissue. Moreover, despite sparsity of tumour cells the specimens taken from surrounding areas showed elevated activities of the same enzymes. The findings indicate an upregulation of the activity not only in tumour but also in normal cells of the surrounding area.

A selected group of 36 patients with suspected supratentorial gliomas were investigated with positron emission tomography (PET) using 11C-methionine and transmission computed tomography (CT) before and after intravenous injection of contrast medium. Every examination was performed with the head fixed in a plastic helmet and a baseplate to guarantee that the slice orientation was the same at examinations with the two modalities and over time. Guided by the examinations, multiple stereotactic biopsies were performed with the biopsy instrument mounted on the baseplate. Regional accumulation of methionine was compared with histology of the corresponding samples and with attenuation before and after injection of contrast medium as well as mass effect on CT. Typically, there was a low attenuating lesion with a slight mass effect on CT. There was an increased accumulation compared with normal brain tissue in 31 cases of tumours and ordinary or decreased accumulation in 3 cases of tumours. In 22 cases with increased accumulation of methionine the extension of the tumour judged by PET corresponded with that of histology. In 4 cases tumour cells were found outside the area with pathologic methionine uptake. In 5 patients there were areas with increased methionine accumulation where no tumour cells were found. In 22 cases PET using methionine was more accurate than CT in defining the tumour boundaries as determined from the histologic findings. Four groups of biopsy specimens with different amounts of methionine accumulation are described. The uptake in a single biopsy gives good but not exact information about the histology of the specimen.

Summary Neuropeptide Y (NPY) was measured in central and peripheral cerebrospinal fluid (CSF) in patients suffering from various intracranial disorders. The central NPY-like immunoreactivity (LI) level showed a concentration of 129±19 pmol·l-1 and was significantly increased (p<0.05) compared to peripheral CSF (73±9 pmol·l-1). From five patients with subarachnoid haemorrhage the CSF NPY-LI levels reached 154±47 pmol·l-1. In five patients peripheral and central CSF was collected at the same occasion and the CSF NPY-LI concentration was 76±17 pmol·l-1 in peripheral and 142±23 pmol·l-1 in central CSF (p<0.01), respectively. In a reference group of 9 patients, who were examined by lumbar myelography because of suspected intervertebral herniated discs, the peripheral CSF NPY-LI concentration was 59±5 pmol·l-1 a value which was also significantly lower compared to NPY-LI levels in central CSF.

Summary 26 patients with subarachnoid haemorrhage (SAH) were investigated with 68-Ga-EDTA and positron emission tomography (PET) in order to evaluate the presence of a blood brain barrier (BBB) disturbance. Only one patient showed a BBB disruption. It is suggested that increased levels of substances with higher molecular weight than 68-Ga-EDTA in the cerebrospinal fluid (CSF) are the result of a change in the metabolism of the CSF and the brain tissue caused by a SAH.

Summary The blood lymphocyte population of 118 patients with primary intracranial tumours and healthy volunteers was examined with respect to its size and cellular composition using various rosette tests. The patients had not undergone any surgical intervention or received any treatment with ionizing irradiation or cytotoxic drugs. However, some of them were treated with corticosteroids.

Summary The somatomedins, multitargit growth-promoting peptide hormones, were measured with radio receptor assay in cerebrospinal fluid (CSF) after subarachnoid haemorrhage (SAH) in 21 patients and after head injury in 2 patients.

Summary Twenty amino acids were determined chromatographically in cerebrospinal fluid (CSF) from 26 patients and in plasma from 13 of the patients with subarachnoid haemorrhage (SAH). In the first group of 13 patients, from which lumbar CSF and plasma were collected on days three, six and nine after SAH, there was a significantly increased CSF concentration from day three to six and/or nine in all amino acids except for taurine which was within the normal range.

Summary The brain tissue reaction to a recently devised titanium haemoclip and to the conventional silver and tantalum clips was investigated in rabbit brain. Titanium, silver, and tantalum wires 5×0.5×0.5 mm in size were implanted into the white matter of the brain. After one and six months the brain specimens were sectioned, stained with haematoxylin eosin and with phosphotungstic acid Haematoxylin, and were studied by light microscopy. The examination revealed neither tissue reaction nor pigmentation in the case of titanium implant, while there was pigmentation surrounding the tantalum, and there was pigmentation as well as reactive gliosis around the silver wires.

Ten patients with findings at computed tomography (CT) suggesting intracranial supratentorial glioma were investigated to compare the diagnostic efficacy of this technique with that of positron emission tomography (PET) using 11C-methionine and exminations with magnetic resonance (MR). The findings were related to histopathologic examination of serial stereotactic biopsies, which were guided by the appearance of the lesions on PET examination. To obtain corresponding slice orientation with the different examination techniques, an individually shaped helmet fixation was used. However, in 3 cases this fixation device could not be used for MR. Histopathologic diagnosis, obtained in all cases from multiple target stereotactic biopsies, included glioma in 9 patients and reactive gliosis in one case. A detailed comparison of the three imaging techniques and the findings at stereotactic biopsies was possible in 7 patients, while in 3 patients comparison with MR was less exact due to the patient's refusal to wear the helmet during this examination. MR was the most accurate method for outlining the total extent of a lesion, i.e. the tumor and the edema surrounding it. Four lesions had homogeneous signal characteristics and in 6 lesions two (or more) compartments could be distinguished with MR. In 5 cases the MR findings were in complete agreement with the histopathologic findings. However, a thorough correlation between signal characteristics and histology was not possible. Using PET the occurrence and the extent of tumor tissue was correctly predicted in 7 patients. The PET was normal in one case. Findings at CT were in agreement with the histopathologic diagnosis in 5 patients. MR was the most sensitive method for the detection of lesions. PET using methionine appeared to have a somewhat higher capacity to outline correctly the true extent of a tumor. The combination of CT and PET was superior to MR for determining the type and grade of the tumors.

Serial ECG analysis is an important diagnostic tool in which two or more successive ECG recordings from the same patient are compared in order to find changes due to, e.g. myocardial infarction. The present study investigates a new approach to serial analysis which is based on artificial neural networks. Interrecording changes are sometimes falsely detected due to electrode misplacement or positional changes of the heart. In order to compensate for such problems, a new technique for VCG loop alignment was employed. A study population of 1000 patients with two recordings was used and manually scrutinized by three experienced ECG interpreters. Pathological changes indicating newly developed infarcts were found in 256 patients. Different combinations of VCG/ECG measurements served as input data to the neural network. The best performance of the neural network was obtained when ECG and VCG measurements were combined and the resulting sensitivity was 69% at a specificity of 90%. The use of only ECG or VCG measurements reduced the sensitivity to 63% and 60%, respectively. The results indicated that serial analysis based on neural networks did not improve significantly when VCG loop alignment was included.

A selected group of 36 patients with suspected supratentorial gliomas were investigated with positron emission tomography (PET) using 11C-methionine and transmission computed tomography (CT) before and after intravenous injection of contrast medium. Every examination was performed with the head fixed in a plastic helmet and a baseplate to guarantee that the slice orientation was the same at examinations with the two modalities and over time. Guided by the examinations, multiple stereotactic biopsies were performed with the biopsy instrument mounted on the baseplate. Regional accumulation of methionine was compared with histology of the corresponding samples and with attenuation before and after injection of contrast medium as well as mass effect on CT. Typically, there was a low attenuating lesion with a slight mass effect on CT. There was an increased accumulation compared with normal brain tissue in 31 cases of tumours and ordinary or decreased accumulation in 3 cases of tumours. In 22 cases with increased accumulation of methionine the extension of the tumour judged by PET corresponded with that of histology. In 4 cases tumour cells were found outside the area with pathologic methionine uptake. In 5 patients there were areas with increased methionine accumulation where no tumour cells were found. In 22 cases PET using methionine was more accurate than CT in defining the tumour boundaries as determined from the histologic findings. Four groups of biopsy specimens with different amounts of methionine accumulation are described. The uptake in a single biopsy gives good but not exact information about the histology of the specimen.

Summary A retrospective study of cerebral angiographies from 173 patients with subarachnoid haemorrhage (SAH) were investigated and divided into three groups. The diameters of the middle cerebral artery and the internal carotid artery were measured and correlated with time elapsing between the onset of SAH and the angiographic study. A significant (p<0.001) reduction in vascular diameter was found at all levels of intraas well as extradural parts of the internal carotid artery in patients with aneurysms (group I). Also, bilateral angiographic investigation from 70 patients showed a significant (p<0.001) reduction at all levels on both sides, regardless of whether aneurysms were present (group II) or not (group III). Moreover, the reduction in vascular diameter was more pronounced in patients with than in patients without aneurysms. The most pronounced reduction in vascular diameter was found in one of the extradural parts of the internal carotid artery in both group II and III. However, reduction in vascular diamter did not correlate significantly with the cerebral circulation time despite a tendency towards it. On the other hand, layering of the contrast medium along the posterior wall of the internal carotid artery was more often found in patients with prolongation in cerebral circulation time suggesting a reduced cerebral blood flow in these patients. It is suggested that the significant reduction in vascular diameter of intra-as well as extradural parts of the internal carotid artery, might reflect an adaptation to altered cerebral metabolism after SAH.

Summary Thirtynine (39) patients with subarachnoid haemorrhage (SAH) were studied with computed tomography (CT). The amount of blood in the cerebrospinal fluid (CSF) and the degree of hydrocephalus were evaluated. These two parameters were correlated with the clinical condition on admission and at discharge and against CSF concentration of a series of CSF substances. These included the major monoamine metabolites homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylethyleneglycol (MOPEG) and in addition the concentrations of hypoxanthine, aspartate and somatomedins. The amount of blood and the degree of hydrocephalus on admission did not seem to influence the concentration of these substances over time. It was found that patients with large amounts of blood in the CSF had a worse clinical outcome (p<0.05) compared to patients with no or moderate amount of blood. In addition, patients with enlargement of the temporal horns showed a worse clinical condition on admission (p<0.01) than did patients without such enlargement. Despite a significant (p<0.01) vasoconstriction there was no correlation between vascular calibre and concentration of the substances in the CSF. It is speculated whether or not the increased levels of these substances were the result of cell lysis per se, a disturbance of the CSF circulation or to the toxic effect of blood resulting in deranged metabolism in both the CSF and brain tissue after SAH.

Serum and CSF calcium, magnesium, potassium and sodium were analyzed in 14 patients suffering from subarachnoid haemorrhage and in 10 healthy controls. The calcium and potassium concentrations in serum and CSF were decreased while magnesium unchanged and sodium were unchanged. A deranged electrolyte homeostasis was thus detectable in the CSF following subarachnoid haemorrhage. It could not be established whether symptoms of delayed cerebral ischemia were related to CSF calcium and/or potassium levels.

Five patients with glioma were examined with positron emission tomography after the administration of 11C-L-methionine and at a following day with 11C-D-methionine. The rates of accumulation of the tracers were determined in the tumor and in the normal brain tissue according to a graphical technique of Patlak et coll. (24). The accumulation rates for L-methionine were on the average 2.4 times higher than those of D-methionine in the tumors. The corresponding ratio for normal brain tissue was 2.3. It is concluded that in this group of tumors without obvious blood-tumor-barrier breakdown, a stereospecific process with similar properties as in the normal brain tissue, is responsible for the accumulation of the labelled methionine.

The amount and distribution of blood in the cerebrospinal fluid following subarachnoid hemorrhage can be monitored with CT. An investigation of 110 patients was performed retrospectively in 100 patients with a total of 132 CT examinations, and prospectively in 10 patients with 40 CT examinations. During the days following the hemorrhage, the blood was redistributed within the subarachnoid space and eventually reabsorbed. The blood in the basal cisterns was cleared first, whereas the amount of blood in the cortical sulci appeared to increase after a few days, later to be cleared. It is concluded that the redistribution of the blood reflects the circulation of the cerebrospinal fluid, and that the erythrocytes thus act as tracers of this circulation. The amount of blood within the ventricular system was correlated to the size of the ventricles; patients with large amounts of blood within the subarachnoid space had hydrocephalus more often than other patients.

Summary The concentrations of the dopamine metabolite homovanillic acid (HVA), the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MOPEG) were determined in cerebrospinal fluid (CSF) from patients with subarachnoid haemorrhage (SAH) using a mass fragmentographic method.

Summary The adenine nucleotide metabolites hypoxanthine, xanthine and uric acid were determined by high performance liquid chromatography in cerebrospinal fluid (CSF) from 25 patients with subarachnoid haemorrhage (SAH) and from 26 control subjects. In addition, the haemoglobin and protein levels in the CSF of the patients were determined.

Summary The effects of Leucotrienes C4 (LTC4), D4 (LTD4), Prostacyclin (PGI2) and Thromboxane A2 (TXA2) were studied on superfused human cerebral artery strips. LTC4 and LTD4 neither contracted nor relaxed the strips. PGI2 caused a dose-dependent relaxation from 0.2 nmol to 0.8 nmol. When given simultaneously with a vasoconstrictor substance, PGI2 had an almost complete inhibitory effect. TXA2 caused a dose-dependent contraction from 0.03 nmol to 0.15 nmol. Also, TXA2 was more potent than 5-Hydroxytryptamin (5-HT) and prostaglandin E2 (PGE2) with a contraction threshold of about 0.1 nmol. Prostaglandin E1 (PGE1), H2 (PGH2), and F2a (PGF2a) had contraction thresholds of about 1 nmol. Only a stable endoperoxide analogue (EPA), was more potent than TXA2, with a contraction threshold of 0.005 nmol. The possible role of these substances in producing ischaemic manifestations after subarachnoid haemorrhage (SAH) is discussed.

Based on animal research suggesting that nerve growth factor (NGF) can stimulate central cholinergic neurons, the known losses of cholinergic innervation of the cortices in Alzheimer's disease (AD), and our experience of infusing NGF to support adrenal grafts in parkinsonian patients, we have initiated clinical trials of NGF infusions into the brain of patients with AD. Here we report a follow-up of our first case, a 69-year-old woman, with symptoms of dementia since 8 years. Intraventricular infusion of 6.6 mg NGF during three months resulted in a marked transient increase in uptake and binding of11C-nicotine in frontal and temporal cortex and a persistent increase in cortical blood flow as measured by PET as well as progressive decreases of slow wave EEG activity. After one month of NGF, tests of verbal episodic memory were improved whereas other cognitive tests were not. No adverse effects could be ascribed to the NGF infusion. Taken together, the results of this case study indicate that NGF may counteract cholinergic deficits in AD, and suggest that further clinical trials of NGF infusion in AD are warranted.

This study compares three extraction methods for PAHs in coal tar polluted soil: 3-times repeated shaking of the soil with dichloromethane-methanol (1:1), Soxhlet extraction with dichloromethane, and Soxhlet extraction with dichloromethane followed by Soxhlet extraction with methanol. The extraction efficiencies were determined for ten selected PAHs in triplicate samples of six soils sampled at former gasworks sites. The samples covered a wide range of PAH concentrations, from 0.6 to 397 mg/kg soil. Soxhlet extraction with dichloromethane followed by Soxhlet extraction with methanol, in general, was the most efficient method yielding 30 to 50 % higher concentrations than the other methods.

Four cases with lesions suspected to be low-grade intracerebral tumours but later proved to be cavernous haemangiomas are described. The patients were examined with contrast enhanced CT and with positron emission tomography (PET). The lesions were partly calcified with a mild or no mass effect and a slight contrast enhancement at CT. There were signs of disrupture of the blood-lesion barrier also on radionuclide studies. PET with 11C-methionine and 11C-glucose showed a normal or decreased accumulation of the tracers. This combination of findings has not been encountered in intracranial tumours. As a comparison, one case of glioblastoma is described. In this patient, the CT findings suggested a cavernous haemangioma. However, PET showed a markedly increased accumulation of 11C-methionine, which is compatible with brain tumour but not with haemangioma.

Five patients with glioma were examined with positron emission tomography after the administration of 11C-L-methionine and at a following day with 11C-D-methionine. The rates of accumulation of the tracers were determined in the tumor and in the normal brain tissue according to a graphical technique of Patlak et coll. (24). The accumulation rates for L-methionine were on the average 2.4 times higher than those of D-methionine in the tumors. The corresponding ratio for normal brain tissue was 2.3. It is concluded that in this group of tumors without obvious blood-tumor-barrier breakdown, a stereospecific process with similar properties as in the normal brain tissue, is responsible for the accumulation of the labelled methionine.

Different multivariate statistical analyses were applied to phospholipid fatty acids representing the biomass composition and to different biogeochemical parameters measured in 37 samples from a landfill contaminated aquifer at Grindsted Landfill (Denmark). Principal component analysis and correspondence analysis were used to identify groups of samples showing similar patterns with respect to biogeochemical variables and phospholipid fatty acid composition. The principal component analysis revealed that for the biogeochemical parameters the first principal component was linked to the pollution effect and to redox processes and the second principal component described the geological and geochemical features of the samples. Dependent on the data transformation of the phospholipid fatty acid profiles in either absolute concentrations (logarithm transformed) or in mol% of total phospholipid fatty acids, different groups of samples and outliers were revealed by the principal component analysis. The principal component analysis on data in absolute concentrations revealed that many phospholipid fatty acids reflected the pollution effect on the biomass composition. In contrast, the phospholipid fatty acids in mol% divided the samples into one group of the more polluted samples and another with the nearly unpolluted samples. The important phospholipid fatty acids for this grouping were mainly a few of the normal saturated phospholipid fatty acids (10:0, 16:0 and 18:0). Discriminant analysis was used to allocate samples of phospholipid fatty acids into predefined classes. A large percentages of samples were classified correctly when discriminating samples into groups of dissolved organic carbon and specific conductivity, indicating that the biomass is highly influenced by the pollution. In contrast, the discriminant analysis revealed that on the basis of the profiles of phospholipid fatty acids no good discrimination between samples showing dominant sulfate reduction and dominant iron reduction could be made, nor between samples showing dominant nitrate reduction and aerobic respiration. Partial least square analysis related the phospholipid fatty acids data to the biogeochemical parameters assuming linear relationships. After selection of the optimal phospholipid fatty acid combination by genetic algorithms, good partial least squares models with low prediction errors were gained primarily between the biogeochemical parameters describing total contents of carbon, pH and chloride. The models predicting specific activity in terms of, e.g., sulfate reduction activity in a sample had relatively higher prediction errors and low correlation coefficients. This indicates that the phospholipid fatty acid profiles from complex habitats have limited value for identifying more specific microbial populations.

Endotoxins from Gram-negative bacteria have been shown to be potent biological activators and are involved in many pathological reactions (Yagoda et al.1990). Since endotoxins are ubiquitous compounds, they can create serious problems for the pharmaceutical industry. There are several examples of unavoidable drug contamination and of endotoxins that cannot be removed from recombinant procedures involving Escherichia colibacteria (Yagoda et al.1990). It is difficult to establish a true threshold dose at which endotoxins will cause clinical effects, but doses less than or equal to 3 ng/kg body weight (bw) can cause fever, chills and headache in humans (Elin et al.1981). Another reference gives 5 endotoxin units (EU)/kg bw for similar clinical symptoms (Anon.1987). Vaccines prepared using E. colibacteria have a high potential for endotoxin content. This is important because endotoxin contamination in general can distort analyses of pharmacological studies and produce unpredictable and erratic effects on animals that receive contaminated vaccines. It is therefore important to identify possible effects of endotoxin-containing vaccines on various physiologic endpoints. It is also pertinent to assess the magnitude of any potential risks involved in using such vaccines. The purpose of this study was to evaluate the blood chemical and clinical response of castrated young boars to commercially available vaccines to E. coliwhere the bacteria have been formaldehyde killed and the endotoxins have not been removed.

Total IgG subclass levels, anti-viral, anti-myelin basic protein (anti-MBP), and anti-ganglioside 1 (anti-GM1) IgG subclass levels were measured in 6 patients with herpes simplex virus encephalitis (HSVE), 16 with borreliosis, 8 with other bacterial infections, 12 with multiple sclerosis (MS), 13 with subacute sclerosing panencephalitis (SSPE), 5 with glioblastoma and 12 controls. Total IgG1 levels were elevated in cerebrospinal fluid (CSF) from all patient groups (but not in the controls), IgG2 in bacterial infections, IgG3 in HSVE and borreliosis and IgG4 in some SSPE patients. The anti-viral (anti-measles, varicella zoster virus and rubella) IgG antibodies in MS were restricted to IgG1, anti-measles IgG to IgG1 and sometimes IgG4 in SSPE, anti-borrelia IgG to IgG1, IgG2 and IgG3. In contrast to anti-viral antibodies, anti-MBP and GM1 antibodies belonged to IgG1, IgG3 or IgG4 in MS. The nature of the immunological activation appears to be reflected in the subclass patterns elicited in the central nervous system. Different IgG subclass patterns in infectious diseases and MS suggest a difference between antigen-specific and non-specific B-cell activation.

Disruption of the blood brain barrier or rather blood tumour barrier in cerebral tumours was studied with CT after intravenous injection of contrast medium and with PET after intravenous administration of 68-Ga-EDTA. Histology from stereotactic biopsies or open surgery is compared with the radiologic findings and advantages of the respective methods are discussed. The material consisted of 47 patients mainly with supratentorial gliomas and a few miscellaneous tumours. Astrocytomas (Kernohan grade II) were found to have no disruption of blood tumour barrier while anaplastic astrocytomas and glioblastomas (Kernohan grade III and IV) had. PET is somewhat superior to CT in detection of disruption of the blood tumour barrier. It is concluded that the combination of CT and PET is of value in the assessment of intracranial tumours.

The main objective of the present study was to investigate the effects of short-term fasting in gilts on endocrinological and blood biochemical parameters and, further, the effects of subsequent oral endotoxin (ET) administration. Group 1 was fasted for 30 h and then received feed with ET added. Group 2 was fasted for 30 h but received standard feed at refeeding. In group 3, gilts were fed every 6 h for 30 h. The major effects of fasting were: gradually increased concentration of plasma prostaglandin F2αmetabolite, serum total bilirubin, serum free fatty acids, and decreased serum glucose. The values were normalized within 1–4 h of refeeding. Twelve hours after refeeding, the ET-refed gilts showed higher levels of serum total bile acids and polymorphonuclear leukocytes than those in group 2. It is possible that the observed changes during fasting reflect either an increased intestinal uptake of naturally present endotoxin or a reduced endotoxin detoxifying capacity of the liver. The increased bile acid concentration and polymorphonuclear leukocyte count following refeeding with ET-feed may indicate that orally administered ET is to some extent absorbed from the gut.

Three prepubertal gilts were each given 100 mg of endotoxin (ET) in their ordinary feed rations, twice daily for 6 days; 3 other gilts received standard feed. Following ET feeding, all animals were injected intravenously (i.v.) with ET (1.0 µg/kg b.w.) once daily for 5 days. Blood samples were collected and analysed for hematology and total serum bile acids (S-BA), glutamate dehydrogenase (S-GLDH), calcium (S-Ca), iron (S-Fe), zinc (S-Zn) and a blood plasma metabolite (15-ketodihy-dro-PGF2a; P-PG) of prostaglandin F2a. The animals showed no apparent clinical symptoms following ET-feeding, neither did the blood analyses reveal effects of oral ET. However, when iv ET injections were given, the ET-fed animals showed fewer clinical signs of endotoxemia following the 2nd to 5th injection. S-BA and S-GLDH increased markedly in the standard-fed group following the first injection, while the ET-fed animals showed a much smaller increase in S-BA and no change in S-GLDH on that day. The difference in response may be explained by a direct uptake of ET from the gastrointestinal tract in the ET-fed pigs, making them less sensitive to the injected ET

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