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Biomedical subjects

L Samuelsson

Publications and source records attributed to L Samuelsson.

At least 73 records · Page 4Linked to original sources

Electrolytic destruction of tissue in the normal lung of the pig.

Platinum electrodes were inserted by a percutaneous technique into the lungs of pigs. The direct current between the electrodes caused destruction of tissue by electrolysis. At the anode, chloride ions were oxidized to chlorine, which diffused into the surrounding lung tissues, creating lesions which were well demarcated and up to 30 mm in diameter. Various types of electrodes were tested, and the size of the lesion was observed to vary with electrode construction and with the dose given.

Animals↗

Electrolysis and surgery in experimental tumours in the rat.

An experimental tumor (DMH W49) was inoculated subcutaneously in rats and treated by either electrolysis or surgery. The efficiency of these treatments was approximately the same. There was no evidence that electrolytic treatment led to the production of humoral antibodies against the tumour.

Adenocarcinoma↗

Experimental stand for chest radiography in rabbits.

A stand and a technique for obtaining good quality chest films in rabbits are described. The animal is held in an upright position in its forelegs and in this position it does not breathe if adequately anesthetized.

Animals↗

Electrolytic destruction of lung tissue in the rabbit.

Tissue destruction was produced by electrolysis after insertion of electrodes into the rabbit lung. The anode was the active electrode and the best electrode material was platinum. The lesions formed around the electrode were well demarcated and their size varied in relation to the charge applied. Complications were few and the lesions healed quickly. Tissue injury occurs as the result of chlorine liberation at the anode, the basis for which is chloride ion oxidation.

Animals↗

Electrolyte destruction of lung tissue. Electrochemical aspects.

The electrochemical basis for tissue destruction by electrolysis was analysed. Electrolytic lesions from pig lungs had a higher content of organically bound chlorine than normal tissue and it is suggested that chlorine, liberated at the anode, is the principal agent in the electrolytic destruction of tissue. The electrode systems that were most effective in destroying tissue produced the lesions with the highest content of chlorine. Experiments in physiologic saline established that a current density of 40 mA/cm2 gave the best yield of chlorine.

Animals↗

Separation and identification of ceramides derived from human plasma sphingomyelins.

Sphingomyelins from human blood plasma have been converted into ceramides by enzymatic hydrolysis with phospholipase C. After acetylation the ceramides were fractionated by thin-layer chromatography on silica gel containing silver nitrate. Four main fractions obtained by this method were subsequently converted to di-O-trimethylsilyl ether derivatives and separated by gas-liquid chromatography on 1% OV-1. 2-11 components could be distinguished in each of the four fractions. The major fractions emerging from the gas chromatograph were analyzed by mass spectrometry and their main molecular species were identified. Two of the gas chromatographic fractions contained essentially pure molecular species, namely N-tetracosenoyl sphingosine and N-tetracosenoylsphinga-4, 14-dienine.

Acetates↗

Psoriasis susceptibility locus in chromosome region 3q21 identified in patients from southwest Sweden.

We have performed a pair-wise linkage study in the search for psoriasis susceptibility regions. A preliminary scan was performed on 20 families. In this set we obtained indications of linkage on chromosome 3q21. This region was further investigated using material from a total of 104 families (set 1B) resulting in a non-parametric linkage (NPL) of 1.77. The material was stratified in families whose parental origin is in southwest Sweden (set 1C). A maximum NPL value of 2.77 was obtained in this group. A transmission disequilibrium test (TDT) was performed on the stratified material (set 1C) and a significant P value of 0.005 was obtained, at marker D3S1269. The locus was confirmed with TDT in replicate material consisting of 148 families in which a single member was affected (P value 0.0007) at marker D3S1551. Thus, we have observed a significant P value using TDT in the vicinity of markers D3S1269/D3S1551, suggesting a novel psoriasis susceptibility region.

Chromosome Mapping↗

Ambulation in patients with myelomeningocele: a 12-year follow-up.

Factors determining change in ambulatory status were studied over a 12-year observation time in 60 ambulating patients with myelomeningocele. There were 26 female and 34 male subjects with a median age of 22 years (range, 12-54). We used the method of Lindseth to define the neurologic level of the lesion and classified walking ability according to the criteria of Hoffer. The prevalence of spasticity and spine and lower-limb deformities was assessed. Orthopedic and neurosurgical interventions and other medical events were registered, as well as occurrence of pressure sores, musculoskeletal pain, and use of orthoses. There were 19 patients with downward transitions in ambulatory level during the follow-up time. Factors explaining deterioration in these 19 patients included deterioration of the neurologic level of lesion, spasticity, knee and hip flexion contractures, low-back pain, lack of motivation, as well as those of major medical events like stroke, recurrent septicemia, lower limb edema, and invasive surgical interventions.

Adolescent↗

Ambulation in patients with myelomeningocele: a multivariate statistical analysis.

Factors determining ambulation in 163 patients with myelomeningocele were studied by a multivariate statistical method. Neurological dysfunction unrelated to the plaque was analyzed by magnetic resonance imaging. There were no ambulators at the thoracic or L1-L2 level. At the L3 level, 54% ambulated, and at the L4 level, 67% ambulated. Eighty percent were ambulators at L5 and all at the sacral level. Below L1-L2, one-half of the nonambulators had neurological deficiencies caused by syringohydromyelia or Chiari malformations preventing ambulation. Severe scoliosis was closely, age moderately, and hip flexion contracture slightly related to the inability of the other nonambulators to walk, while pelvic obliquity, hip dislocation, or knee flexion contracture was not.

Adolescent↗

Electrolytic tissue destruction and external beam irradiation of the lung. An experimental and clinical investigation.

In order to evaluate possible benefits of local therapy of lung tumors--electrolysis at Pt-electrodes percutaneously inserted in the tumor, followed by radiation therapy--6 pigs were used as test objects. Two died of lung hemorrhage due to too fast electrolysis causing lung rupture but the other 4 survived when electrolysis was performed at a lower speed. No complication was observed of the combination of electrolysis and external beam irradiation. One human primary lung tumor was treated and probably destroyed by two electrolytic procedures and irradiation to 64 Gy. The evidence of the limited series of animal experiments and of single human tumor case would indicate that further investigations seem worthwhile.

Adenocarcinoma↗

Delineation of the normal esophagus at computed tomography.

It has been accepted by many that the esophagus in its entire length is easy to delineate at CT in most patients due to surrounding fat planes. As this is not the experience of the present authors, the CT of the thorax in 100 normal men and women without mediastinal disease and in good nutritional status was reviewed, to record the relationship between the esophagus and neighbouring structures. In the upper third of the esophagus there is almost never a definite border between its wall and that of the trachea, while a separating border or even a fat plane can be seen to the spine in between 25 and 50 per cent of those tested. The vessels, as a rule, have a fat plane towards the esophagus. The middle part of the esophagus has the same intimate relationship to the trachea and left main bronchus, i.e. almost never any separating border. Two thirds of the cases have no border to the upper part of the pericardium (left atrium), while about 70 per cent have a border or fat plane towards the aorta. The middle and lower third of the esophagus has, as a rule, a distinct border or fat plane to the spine. In about 50 per cent of the patients the anterior wall of the lower esophagus is separable from the pericardium.

Adipose Tissue↗

Transcatheter intraarterial management of gynecologic tumors.

Intraarterial therapy was performed in 17 women with various gynecologic tumors in order to facilitate surgery (13 patients) and for palliation (4 patients). In the nonsurgery group intraarterial chemotherapy was supplemented by occlusion in 2 patients. In the surgery group 5 women received intraarterial chemotherapy before the occlusion procedure. In the palliation group the result was poor, but 9 of 13 patients in the surgery group had radical surgery. They had all previously been found to be nonresectable at laparotomy (11 patients) or clinically (2 patients). No severe complications of using the intraarterial technique were encountered, though such are frequently reported.

Adult↗

Computed tomography of the thymus gland in myasthenia gravis.

Sixteen consecutive patients with myasthenia gravis were examined by computed tomography (CT) before thymectomy. Surgical and histologic findings were compared with those obtained at CT. The results, like those of most other recent studies, indicate that CT is a reliable method for identifying thymoma. In all three patients with thymoma, and in five out of eight patients with hyperplasia, the lesion was observed at CT, giving an overall accuracy of 80 per cent. Although thymic hyperplasia is a basically histologic diagnosis an enlarged gland may give a correct diagnosis of this abnormality.

Adolescent↗

Conventional spinal radiography as a supplement to the neurologic assessment in myelomeningocele.

In patients born with a myelomeningocele early assessment of the severity of the anomaly is mandatory for planning of therapy. Conventional spinal radiography, although a routine examination, in many hospitals has been regarded as less rewarding. However, in this retrospective investigation of 92 patients, a reasonable conformity was found between conventional radiograms and neurologic deficit at follow-up. There was no significant difference between the results of radiologic examinations carried out during the first 1 to 10 weeks after birth and the later neurologic findings. Hence, the simple radiologic assessment has proved a valuable baseline examination in these patients. In cases with discrepancy between the conventional radiologic and the neurologic findings, and in cases with a course diverging from the anticipated, more sophisticated methods of imaging are recommended.

Adolescent↗