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Biomedical subjects

G Andersson

Publications and source records attributed to G Andersson.

At least 307 records · Page 17Linked to original sources
PubMed1983

Exon-intron organization and complete nucleotide sequence of a human major histocompatibility antigen DC beta gene.

We have determined the complete nucleotide sequence of a human class II histocompatibility antigen DC beta gene. The gene spans more than 7 kilobases and contains five exons corresponding to the different domains of the DC beta polypeptide. The exon-intron organization is thus analogous to that of class II antigen alpha-chain genes, class I antigen heavy chain genes, and the constant parts of immunoglobulin genes, emphasizing further the evolutionary relationship among these molecules. The mature polypeptide deduced from the DC beta gene shows 93% and 88% homology, respectively, to sequences derived from two DC beta cDNA clones of other haplotypes. The allelic polymorphism of DC beta chains resides predominantly in the first extracellular domain, whereas the rest of the polypeptide is virtually constant. The exons of the DC beta gene display high homology to the corresponding exons of a murine I-A beta gene. Also, the introns show significant homology. The DC beta chains lack eight amino acids in the cytoplasmic tail, as compared to DR and I-A beta chains. This is probably due to a nonfunctional splice junction of DC beta genes, causing a separate cytoplasmic exon to be nonexpressed.

Amino Acid Sequence↗
PubMed1983

Clinical assessment of visual functions in infants and young children.

We report our experience with 2 new methods of assessing visual functions in children: grating acuity determination by means of preferential looking technique and contrast sensitivity measurements. Acuity determinations with preferential looking proved useful for evaluation of the effects of amblyopia treatment in young children (0-3 years) with esotropia and for monitoring visual development in children operated early for congenital cataract. We have also used these methods successfully for diagnostic acuity determinations in very young children or in older but mentally retarded children with suspected visual impairment. In 4-year-old children contrast thresholds were determined for sine wave gratings of different spatial frequencies displayed on an oscilloscope screen. The results were less reproducible than those obtained earlier in somewhat older children, and did not correlate as well as the results of other visual tests as in the older children.

Amblyopia↗
PubMed1983

Visual acuity testing with preferential looking in mental retardation.

Twenty-six mentally retarded children and young adults, most of them with severe neurological deficits, in the age range 5-24 years, were examined ophthalmologically, and their binocular visual acuities were tested with 'operant preferential looking' according to the technique of Mayer & Dobson (1980). Five of the subjects did not co-operate sufficiently for visual testing, although 3 had no ocular abnormalities that would affect binocular acuity. The visual acuity levels determined with 'preferential looking' ranged from 1.29 to 0.03 in the 21 subjects that could be tested. Two children with high myopia showed substantial increase in acuity with appropriate correction (from 0.1 to 1.06 in one child and from 0.05 to 0.31 in the other). Inability to fixate light or objects was found in subjects, who at acuity testing showed values of 0.15 or less. In patients with suspected or definite optic atrophy, visual acuities 0.28 or less were obtained. In general there was a good correlation between ophthalmological abnormalities (in fixation, pupil reactions to light, ocular motility, fundus appearance and refraction) and poor visual acuity. It is therefore concluded that visual acuity testing with 'preferential looking' techniques can give valid information on central visual function in mentally retarded children and young adults.

Adolescent↗
PubMed1983

Origin and sagittal termination areas of cerebro-cerebellar climbing fibre paths in the cat.

Climbing fibre responses were recorded in the cerebellar anterior lobe on stimulation of the cerebral cortex. A zonal pattern was demonstrated in the cortical projection, which was related to the cerebellar sagittal zones, as identified from peripheral climbing fibre input. In all zones, except c2, a co-variation of the responses evoked on peripheral nerve stimulation and on stimulation of the corresponding part of the sensorimotor cortex was found. There was a bilateral projection to the a, b, c2 and d1 zones which also, to a varying extent, receive a bilateral peripheral input. The x, c1 and c3 zones, receiving an ipsilateral peripheral input, were activated exclusively from the contralateral cortex. Stimulation of the posterior sigmoid gyrus (p.s.g.) evoked responses in all the zones. These responses had, in all zones except d1, lower thresholds and shorter latencies than the responses from other cortical areas. Two separate p.s.g. areas were shown to project to the pars intermedia zones (c1, c2, c3 and d1), the lateral area to the caudal parts and the medial area to the rostral parts of the zones. In contrast, the b zone received a projection from only one p.s.g. area, centred between, but overlapping, the two areas projecting to the pars intermedia zones. Stimulation of the anterior sigmoid gyrus evoked short-latency responses in the d1 zone and long-latency responses in all other zones. Stimulation of the first and second somatosensory areas (SI and SII) was generally less effective in evoking climbing fibre responses than was stimulation of the p.s.g. The only exception was the c2 zone, in which responses were evoked from the SII with nearly as low thresholds and short latencies as on p.s.g. stimulation. From the parietal cortex, long-latency responses were regularly evoked in the d1 zone and less frequently in the a, b and c2 zones.

Animals↗
PubMed1983

Neuraminidase in Bacteroides fragilis.

A neuraminidase from Bacteroides fragilis was purified 542-fold by isoelectric focusing, adsorption chromatography on Affi-Gel 202, and gel filtration chromatography on Sephadex G-200. On isoelectric focusing the neuraminidase was resolved into three differently charged fractions with pI values of 6.8, 7.1, and 7.4. The major component of pI 7.1 was used for further purification. The purified enzyme had optimal activity at pH 6.4 with N-acetylneuraminlactose as the substrate. Its molecular weight, determined by Sephadex G-200 gel filtration chromatography, was 92,000. The neuraminidase hydrolyzed terminal neuraminic acid residues from N-acetylneuraminlactose, fetuin, bovine submaxillary mucin, and porcine stomach lining mucin. A new method for the detection of neuraminidase activity is described which is based on rocket affinoelectrophoresis. It utilizes the differences in the interaction of sialylated and desialylated mucin with Helix pomatia lectin, enzymatic activity being detected by formation of affinorockets after incubation of the neuraminidase with bovine submaxillary mucin.

Bacteroides fragilis↗
PubMed1983

Mechanical effectiveness studies of lumbar spine orthoses.

Intradiscal pressures, intra-gastric pressures and myoelectric trunk muscle activities were measured in four volunteers wearing five different orthoses of three principle types, and performing six tasks. A biomechanical model was used to estimate the load on the spine in the different tasks so as to compare those tasks reliably when done with and without the orthoses. The results indicate that wearing a brace can significantly unload the trunk in some situations, but has no effect in others. Lumbar spine compression was reduced by about one-third in the task involving trunk flexion. The disc pressure values with an orthosis were lower in about two-thirds of the exercises and higher in the remaining one-third. The back muscle activity was in some experiments reduced by one-third by the use of the brace, in others it increased by the same amount. None of the orthoses raised the intra-gastric pressure significantly. No one orthosis was found to be clearly superior in mechanical effectiveness in the tasks studied.

Adult↗
PubMed1983

Surgery versus chemonucleolysis for herniated lumbar discs. A prospective study with random assignment.

The results of removal of a disc hernia at the L4/L5 level were compared with those obtained by the injection of 4000 IU (2 ml) of chymopapain (Discase) in 29 consecutive patients randomly selected for either treatment. All exhibited severe incapacitating sciatica, and all had a myelogram demonstrating a definite disc hernia. The two groups of patients did not differ significantly with regard to age, sex, or length of history. The total time of general anesthesia was significantly shorter for the injected patients by 20 minutes (p less than 0.01), as was the length of hospitalization, by three days (p less than 0.05). Within five months, eight of the patients receiving chymopapain injections had to be operated on because of unrelieved symptoms. All had definite disc herniae, and in four, a free fragment was found. All patients were seen at the time of dismissal from the hospital and at six and 12 months after operation by an independent observer. Comparisons made at these intervals, following either surgery or chymopapain injection with or without subsequent surgery, did not reveal any significant differences, but the short-term results following either treatment alone significantly (p less than 0.01) favored the surgical approach.

Adult↗
PubMed1982

Subcutaneous administration of heparin. A randomised comparison with intravenous administration of heparin to patients with deep-vein thrombosis.

One-hundred and forty-one patients with clinical signs of acute deep venous thrombosis (DVT) in the legs were randomly allocated to receive heparin either as two daily subcutaneous injections (s.c.) or as continuous intravenous infusion (i.v.). The thrombi extended into the popliteal or femoral veins in 83% of the patients. Verification of diagnosis and evaluation of therapy was performed by phlebography, plethysmography and thermography. The results showed that heparin administered s.c. twice daily was as efficient as continuous i.v. infusion in preventing extension of the thrombus. In two patients the s.c. administration was stopped due to local haematomas at the injection sites. Retroperitoneal or intramuscular bleedings occurred in four patients, two in each group. Two major, non-fatal pulmonary emboli occurred, one in each group.

Adult↗
PubMed1982

Loads on the lumbar spine. Validation of a biomechanical analysis by measurements of intradiscal pressures and myoelectric signals.

UNLABELLED: We studied the validity of predictions of compressive loads on the lumbar spine and contraction forces in lumbar trunk muscles based on a biomechanical model. The predictions were validated by quantitative measurements of myoelectric activities at twelve locations on the trunk and of the pressure in the third lumbar disc. Twenty-five tasks were performed isometrically by four healthy volunteers. The model predicted that the tasks imposed mean compressive loads on the spine of as much as 2400 newtons and required contraction forces of the posterior muscles of the back of as much as 1800 newtons. Intradiscal pressures of as much as 1600 kilopascals were measured. The predicted and measured quantities were well correlated. It appears that the model adequately predicted the compressive loads on the lumbar spine and the tensions in the back muscles. CLINICAL RELEVANCE: Patients with low-back disorders limit their physical activities, which indicates that loading on the spine must be a factor in those disorders. This study shows that the loads imposed on the spine by physical activities need not be measured. They can easily be calculated. This will significantly accelerate biomechanics research on low-back disorders. The calculation techniques that we validated for predicting loads on the spine can be used to calculate the loads on any skeletal structure. Those loads are largely determined not by the externally applied loads, but by the moments of those applied loads and by the moments of the weights of the body segments that the structure must support.

Abdomen↗
PubMed1981

Spinal, trigeminal, and cortical climbing fibre paths to the lateral vermis of the cerebellar anterior lobe in the cat.

The spinal, trigeminal and cortical climbing fibre projection to the lateral vermis of the cerebellar anterior lobe in the cat has been investigated. The b zone, which occupies a one mm wide band in the lateral vermis, receives a somatotopically arranged input. Successively more rostral segments (tail, hindlimb, thorax, forelimb and trigeminal nerves) project to successively more medial microzones. The b zone receives an input through each of three spino-olivocerebellar paths (SOCPs) ascending in the ventral, dorsal and dorsolateral funiculi (VF, DF and DLF). In the b zone, the hindlimb input is bilateral through the VF-SOCP and ipsilateral through he DF- and DLF-SOCPs. The forelimb input is bilateral through the VF-SOCP, ipsilateral through the DLF-SOCP and lacking from the DF-SOCP. The trigeminal input is bilateral. Medial to the b zone in lobule V is the x zone, which receives an input from the ipsilateral forelimb through the DF- and DLF-SOCPs. The climbing fibres to the x zone are collaterals of the climbing fibres projecting to the c1 zone in the pars intermedia and paramedian lobule. The climbing fibre input from the cerebral sensorimotor cortex to the lateral vermis matches the spinal input. The lateral and medial parts of the b zone receive a bilateral input from hind- and forelimb cortical areas, respectively. The x zone receives an input from the contralateral forelimb area. The functional significance of the converging paths is discussed.

Afferent Pathways↗
PubMed1981

Serum level of biliary glycoprotein I, a determinant of cholestasis, of similar use as gamma-glutamyltranspeptidase.

Biliary glycoprotein I (BGP I), a constituent of normal bile and serum, is a glycoprotein (mol. wt. approximately 90,000) containing about 40% carbohydrate. Serum BGP I (S-BGP I) was determined by means of a double-antibody radioimmunoassay in patients with liver and gastrointestinal disease and in healthy individuals. The serum levels of five liver enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase (S-ALP), gamma-glutamyltranspeptidase (S-GT), and lactic dehydrogenase), bilirubin (total and conjugated), and bile acids (cholic and chenodeoxycholic acid) were determined in parallel. Healthy individuals had 0.5 +/- 0.3 mg/l of S-BGP I (mean +/- 2 S.D.; range, 0.2-0.9 mg/l). Most patients with liver disease (chronic hepatitis, alcoholic cirrhosis, primary biliary cirrhosis) had elevated levels, up to 5-10 times the upper reference limit, whereas most patients with gastrointestinal disease (ulcerative colitis, Crohn's disease, other GI diseases) had normal values. In patients with liver disease S-BGP I was positively correlated (p less than 0.0005) to S-GT. In primary biliary cirrhosis a positive correlation (p less than 0.005) between S-BGP I and S-ALP was also obtained. All other comparisons between S-BGP I and the other liver function tests showed non-significant correlations. It is concluded that S-BGP I is a determinant of cholestasis of similar use as S-GT.

Adolescent↗
PubMed1981

Shoulder pain in industry: an epidemiological study on welders.

The occurrence of supraspinatus tendinitis in a group of welders at a shipyard was investigated, and compared with the occurrence of this condition in a group of office clerks. The study showed a prevalence ratio of 18 per cent in the welders, significantly higher than in the clerks. The average age (39 year) in the group with pain did not differ significantly from the average age in the entire group of welders. It is concluded that supraspinatus tendinitis is not exclusively an aging phenomenon, but that welding as an occupation plays an etiological role.

Adult↗
PubMed1981

Urinary polyamine excretion during growth and regression of 1,12-dimethylbenz[a]anthracene-induced rat mammary carcinoma.

The correlation of urinary excretion of polyamines and tumor mass was examined with the use of a controlled experimental model. Mammary carcinoma growth was induced in Sprague-Dawley virgin rats by intragastric administration of 7,12-dimethylbenz[a]anthracene. Tumors were palpable after about 45 days. After a period of growth, regression of the estrogen-dependent tumors was induced by bilateral ovariectomy. Tumor volume and 24-hour urinary excretion of polyamines were measured during the course of tumor growth and regression. Urinary polyamines were analyzed after acid hydrolysis to determine the total amount of bound and free polyamines. Putrescine excretion followed closely the changes in tumor volume during the course of tumor growth and regression. Urinary spermidine excretion, however, remained essentially unchanged in ovariectomized rats; spermine was barely detectable in any of the urines. There was a high positive correlation between the 24-hour urinary putrescine excretion and urine volume. In nonovariectomized rats, the mammary tumor(s) continued to grow. An unexpected result of the advanced tumor progression was that urinary excretion of both putrescine and spermidine decreased steadily with time as did urine volume. This phenomenon may be due to the fact that complex disturbances of the host metabolism, manifested in decreasing body weight.

9,10-Dimethyl-1,2-benzanthracene↗