Search PubMed⌕ Search

Biomedical subjects

T Johansson

Publications and source records attributed to T Johansson.

At least 91 records · Page 5Linked to original sources
PubMed1989

S-100 protein in cerebrospinal fluid after aneurysmal subarachnoid haemorrhage: relation to functional outcome, late CT and SPECT changes, and signs of higher cortical dysfunction.

The concentration of S-100 protein measured in ventricular cerebrospinal fluid (CSF) from 32 patients with subarachnoid haemorrhage (SAH) during the acute phase was related to features on admission such as the Hunt and Hess neurological scale and the amount of blood at the first computed tomography (CT). The S-100 values were also related to functional outcome assessed by the Glasgow outcome scale (GOS) at 12 months. Twenty-two patients were re-examined more than 2 years after the SAH, and the initial S-100 values were related to signs of structural brain damage at CT and single photon emission computed tomography (SPECT) and to the results of neuropsychological evaluation (NPE). NPE included standardized tests for memory functions, intellectual functions, visuo-spatial abilities, sensory-motor functions, and concept formation. Life-adjustment was assessed by two separate questionnaires. Tests for agnostic dysfunction and the Western aphasia battery test (WABT) were also performed. Patients who were functionally disabled or ultimately died had significantly higher initial CSF concentrations of S-100 protein than patients showing good recovery. Patients with low-attenuated regions and/or increased ventricular size at CT and/or regionally decreased tracer uptake on SPECT had higher S-100 levels during days 2-8 than had patients showing no such changes. Logistic and multiple regression analysis of all characteristics assessed during the acute phase after SAH showed that the CSF S-100 concentration during days 2-8 was the factor best correlated to GOS and findings on CT and/or SPECT. All patients showed varying degrees of cognitive impairment at follow-up. The results of NPE and the WABT were related to outcome assessed by GOS and to increased ventricular size on CT. Women had a stronger feeling of maladjustment, but the scores for life adjustment were otherwise not related to other outcome criteria. It is concluded that the ventricular CSF S-100 concentration during the acute phase after SAH is related not only to the functional outcome as assessed by GOS but also to signs of brain damage seen on late CT and SPECT.

Adult↗
PubMed1989

Cloning and characterization of variable-sized gypsy mobile elements in Drosophila melanogaster.

A cosmid genomic library from a known gypsy-induced forked mutation, f1, was screened by 32P-labeled gypsy transposable element. Of more than 250 positive clones we randomly selected 21 for in situ hybridization to wild-type polytene chromosomes. Two clones hybridized to region 15F on the X-chromosome, the cytological position of forked. A third clone hybridized to at least 17 sites on the chromosomes indicating the presence of repetitive sequences in the gypsy flanking DNA. All clones labeled the centromeric regions heavily. Ten clones, including the two hybridizing at 15F, were chosen for further analysis, and restriction mapping allowed us to place them into three groups: (1) full-length, (2) slightly diverging, and (3) highly diverging gypsy elements. Group (2) is missing the XbaI site in both their long terminal repeats (LTRs) as well as the middle HindIII site; four of these gypsy elements also have a approximately 100-bp deletion at the 5' LTR. The group (3) gypsy transposons are missing one LTR and also have highly diverging DNA sequences. The restriction analyses further imply that most of these different gypsy elements are present in more than one copy in the genome of the f1 stock used in this study. The results raise intriguing questions regarding the significance of transposable elements in evolution and biological functions.

Animals↗
PubMed1989

Presence of mutans streptococci and various types of lactobacilli in interdental spaces related to development of proximal carious lesions.

During a 2-yr study period samples from saliva, the tongue, and 276 interdental spaces were obtained from 23 7-yr-old children in order to (a) relate the presence of lactobacilli in various oral sites to the occurrence of lactobacilli in saliva, and (b) relate the presence of mutans streptococci and various types of lactobacilli interdentally to the development of proximal carious lesions. The results showed an increased number of interdental samples containing lactobacilli with an increasing number of salivary lactobacilli. Furthermore, lactobacilli were never found interdentally without the presence of mutans streptocci, lactobacilli proved to be the more suitable microorganism for prediction of proximal carious lesions. Neither the number nor the differentiation into different species of interdental lactobacilli seemed to be of importance, but simply whether they were present. The presence of lactobacilli probably reflects a caries-inducing environment (etiologic microflora + fermentable carbohydrates), thus explaining their high predictive ability compared to their rather limited etiologic importance in the initiation of decay.

Child↗
PubMed1988

Cerebral infarctions studied by [123I]iodoamphetamine. Clinical aspects of the findings on single photon emission computed tomography and transmission computed tomography.

We have used single photon emission computed tomography (SPECT) and the radioisotope [123I]-iodoamphetamine to study 16 patients with cortical and central cerebral infarctions. In 12 cases SPECT, in addition to changes at the site of infarction, showed areas of deficient uptake in other regions of the brain. Diaschisis as well as infarctions, not detected on the transmission computed tomography scanning, seem to explain these findings.

Aged↗
PubMed1985

Evidence that transcription of the hexokinase gene is increased in a rapidly growing rat hepatoma.

The level of hexokinase-specific mRNA in rat liver and in rat ascites hepatoma (Zajdela) was assessed by translating free polysomes from both cell types in a reticulocyte lysate. Translation of hexokinase occurred with approximately a 10 fold higher frequency in tumor cells than in liver, suggesting that transcriptional activation is in part responsible for increased levels of hexokinase in tumor.

Animals↗
PubMed1985

Content of histone H1 and histone phosphorylation in relation to the higher order structures of chromatin in Drosophila.

The amount of histone H1 relative to core histones has been determined in three Drosophila species (D. melanogaster, D. texana and D. virilis) in chromatin from several tissues differing in chromatin structure and genetic activity. Low levels of H1 were found in relatively undifferentiated, early embryos as well as in a line of cultured cells. In late embryos the content of H1 was highest in D. virilis which possesses larger amounts of and a partially more compacted constitutive heterochromatin than the two other species. Polytene chromatin from larval salivary glands showed increased levels of H1 compared with diploid chromatin and the degree of phosphorylation of this histone was relatively low. The degree of phosphorylation of H2A was found to be drastically reduced in polytene as compared with diploid embryonic chromatin, which parallels the extensive underreplication of constitutive heterochromatin. Also, in diploid chromatin a qualitative correlation was observed between the relative amounts of heterochromatin and the levels of H2A phosphorylation. These findings suggest a connection between H2A phosphorylation and heavy compaction of interphase chromatin.

Animals↗
PubMed1985

Occipital infarctions associated with hemiparesis.

71 patients with a CT-verified infarction in the irrigation area of the posterior cerebral arteries were studied retrospectively. In 17 subjects a hemiparesis was associated with the occipital infarction. The hemiparesis was not associated with brainstem symptoms and in none of these cases a concomitant infarction in the territory of the middle or anterior cerebral arteries was found. No adequate cause was found for the hemiparesis. A simultaneous lesion of one of the small penetrating branches of the posterior cerebral artery was thought to be a possible explanation.

Adult↗
PubMed1984

Cerebral infarctions with negative CT scans.

A selection of 181 stroke patients with a negative scan on computed tomography (CT) was studied. The CT scans were done at least 24 h after ictus. 39 of these cases were excluded because of a cortically located pathological uptake on a concomitant radionuclide scan. The 142 remaining cases were compared with patients who had CT-verified central and cortical infarctions. The CT-negative infarctions showed a profile of risk factors similar to the one in CT-verified central infarctions. It differed markedly, however, from the clinical picture of the cortically located infarctions. Thus, the subjects with a negative CT and isotope scan had a lower percentage of carotid lesions of hemodynamic significance (studied by isotope angiography) and a lower frequency of atrial fibrillation. There was also a much higher percentage of pure motor hemipareses among the CT-negative infarctions. This suggests that a great part of CT- and gamma camera-negative cerebrovascular infarctions may be suspected to be small lacunae, which are beyond the resolution capacity of the CT scan.

Aged↗
PubMed1981

Heavy drug abuse in Sweden 1979 - a national case-finding study.

An investigation was carried out as a case-finding study to estimate the scale of heavy drug abuse in Sweden. Just over 8200 persons were reported as heavy drug abusers, 80% of these as injecting. For the majority of those reported more than one type of drug was indicated. There was concurrent abuse of alcohol by a majority of the heavy drug abusers. After correction of non-response with a modified capture-recapture technique and for erroneous classification, the scale of heavy drug abuse was estimated at 10000 - 14000 persons.

Adult↗
PubMed1981

Isolation of the cytochrome-bc1 complex from rat-liver mitochondria.

The cytochrome bc1 complex has been isolated from rat-liver mitochondria by two different procedures. The enzyme isolated by either procedure exhibits a specific cytochrome b and cytochrome c1 heme content of approximately 8 and 4 nmol/mg protein respectively. Both preparations contain only seven polypeptides on sodium dodecylsulfate gel electrophoresis, with the following apparent molecular weights: I, 50000; II, 46000; III, 33000; IV, 25000; V, 12500; VI, 10000; VII, 5600. The polypeptide composition is identical to that of the beef-heart enzyme isolated by cholate/ammonium sulfate fractionation. Furthermore, with the exception of subunit II (core protein 2), the apparent molecular weights of the subunits are identical in the rat-liver and beef-heart enzymes.

Animals↗
PubMed1979

Alexia without agraphia: lateral and medial infarction of left occipital lobe.

Four cases of alexia without agraphia were studied by 99m-technetium pertechnetate brain scan. Two types of increased uptake were seen. One was of the triangular type near the midline in the posterior view, said to characterize an infarction in the distribution area of the posterior cerebral artery. This was associated with the well-known clinical picture of alexia without agraphia accompanied by hemianopia and color-naming defect, and was confirmed by postmortem examination. The other type of pathologic isotope uptake, observed in three patients, was more laterally placed, in the basal part of the left occipital lobe, and did not reach the midline. In these cases the alexia was transient and not associated with color-naming defects.

Adult↗
PubMed1978

Aflatoxin in a Swedish grain sample.

So far aflatoxin has not been detected in crops grown in Sweden but only in imported feedstuffs or in feed mixtures containing imported products. During the survey for other mycotoxins in Swedish crops a compound was detected in oats which, by further analysis, was identified as aflatoxin B1. Quantitative evaluation showed concentrations as high as 2.6 ppm. The fungal population in this highly contaminated sample consisted almost entirely of Aspergillus flavus.

Aflatoxins↗
PubMed1976

Histone content in relation to amount of heterochromatin and developmental stage in three species of Drosophila.

Relative amounts of various histone fractions in Drosophila chromatin were estimated densitometrically on electrophoretic gel separations. Several consistent and highly significant differences were obtained between larval and adult chromatin. The arginine-rich histones showed the most conspicuous changes: higher amounts of H4 in larvae, higher H3 in adults. The level of modification of these histones was clearly higher in larval than in adult chromatin. The modification of the two slower subfractions of H4 involved, in all probability, phosphorylation as well as acetylation. In all types of Drosophila chromatin studied 50% or more of the H2a molecules were phosphorylated--a remarkably high proportion. The species differences observed in relative amounts of histone were consistent in both stages of development. D. melanogaster differed from D. hydei and D. virilis in all histones except H2b, while the latter two species were generally similar. The interspecific variation in histone pattern was generally not correlated to differences in content of heterochromatin. The level of modification of H2 was, however, presumably an exception, as it was significantly lower for both larvae and adults in D. virilis than in the other two species. These differ from D. virilis in containing appreciably lower proportions of heterochromatic chromosome segments.

Animals↗
PubMed1975

Scintillation camera studies of isotope flow in arteriovenous malformations.

A significant proportion of arteriovenous malformations are still undetected on conventional brain scans. Dynamic scintillation camera studies have shown a pronounced and rapid isotope accumulation in these structures. By means of data processed flow studies, one can distinctly select the inflow phase etc., display TV pictures in optimal phase, and make quantitative comparisons. Thereby, one can obtain a very probable diagnosis, even when the AVM is small or has the characteristics of a fistula which is not seen on routine scans. As the method is simple and not time consuming, it is well suited for clinical screening.

Aged↗