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Biomedical subjects

S Christiansen

Publications and source records attributed to S Christiansen.

47 records · Page 3Linked to original sources
PubMed1992

Secondary surgery in patients with malignant germ cell tumors.

A total of 102 men treated for germ cell tumor with chemotherapy containing cisplatin was referred for a secondary operation with signs of tumor in the retroperitoneum or chest. Of the patients 85 underwent laparotomy, 14 underwent thoracotomy and 3 had both operations. Residual tumors were completely resected in 66 patients and incompletely resected in 30, while no tumor was found in 6. The resected specimen was malignant in 18 patients, of whom 11 had complete removal of all malignant tissue. All patients with malignancy in the resected specimen received further chemotherapy. Long-term disease-free status was obtained in 75% of those patients who had a complete resection, compared with 14% in the group with incomplete resection. There was no evidence of malignant disease at operation in 78 patients but 5 of them later died of the disease. Malignant tissue was present in the residual tumor in only 1 of 15 patients whose primary tumor was seminoma alone. Resection was attempted in 14 patients despite abnormal tumor markers preoperatively. Only 5 of these patients achieved a disease-free status and 2 of them died later of malignant disease. Over-all 79 of the 102 patients are without evidence of disease (medium postoperative observation 23 1/2 months). We conclude that a secondary operation constitutes an important part of the treatment of patients with germ cell cancer.

Adolescent↗
PubMed1991

[Should athletic injuries be treated with non-steroidal anti-rheumatic agents (NSAID)? Tenoxicam, piroxicam and placebo in the treatment of acute stress-induced injuries].

A total of 212 patients with acute sports injuries were allotted at random to treatment with 20 mg tenoxicam daily, 20 piroxicam daily or a placebo for ten days. The injuries could be subdivided into six groups: Tendinitis, periostitis, sprains, tendovaginitis, epicondylitis and muscular ruptures. Treatment was well tolerated and analysis of the total material showed a slight but significantly better effect in the group treated with the active drugs. More detailed analysis revealed that this increased effect was produced by a definitely better therapeutic result in the group of patients with tendinitis treated with non-steroid anti-inflammatory drugs (NSAID) while, in the other types of injury, no definite effect could be observed. On the basis of these observations, the authors conclude that acute tendinitis may be treated with NSAID (tenoxicam) while the question is not yet solved where other acute stress-induced injuries are concerned.

Acute Disease↗
PubMed1988

Bacteriophage lambda DNA packaging: a mutant terminase that is independent of integration host factor.

Lambda+ is able to grow in Escherichia coli cells lacking integration host factor (IHF), producing a burst of approximately 25% that produced in IHF+ cells. In vitro, however, we find that the lambda DNA packaging enzyme terminase is strongly dependent on IHF in both cos cleavage reactions and DNA packaging reactions. The cos59 mutation renders lambda dependent on IHF in vivo. The cos59 mutation is a deletion of 3 base pairs at the XmnI site in the cohesive end site (cos) of lambda. Variants of lambda cos59 that were able to grow in the absence of IHF were isolated and found to carry a mutation, called ms1, in the Nu1 gene, which codes for the small subunit of terminase. The Nu1ms1 mutation results in a change of the 40th amino acid of the Nu1 gene product from leucine to phenylalanine. The Nu1ms1 terminase was independent of IHF in packaging reactions in vitro. The results indicate that the mutation either renders terminase: (1) able to utilize some host protein other than IHF, or (2) totally independent of host factors.

Bacterial Proteins↗
PubMed1988

Domains for protein-protein interactions at the N and C termini of the large subunit of bacteriophage lambda terminase.

The large subunit of phage lambda terminase, gpA, the gene product of the phage A gene, interacts with the small subunit, gpNul, to form functional terminase. Terminase binds to lambda DNA at cosB to form a binary complex. The terminase:DNA complex binds a prohead to form a ternary complex. Ternary complex formation involves an interaction of the prohead with gpA. The amino terminus of gpA contains a functional domain for interaction with gpNul, and the carboxy-terminal 38 amino acids of gpA contain a functional domain for prohead binding. This information about the structure of gpA was obtained through the use of hybrid phages resulting from recombination between lambda and the related phage 21. lambda and 21 encode terminases that are analogous in structural organization and have ca. 60% sequence identity. In spite of these similarities, lambda and 21 terminases differ in specificity for DNA binding, subunit assembly, and prohead binding. A lambda-21 hybrid phage produces a terminase in which one of the subunits is chimeric and had recombinant specificities. In the work reported here; a new hybrid, lambda-21 hybrid 67, is characterized. lambda-21 hybrid 67 is the result of a crossover between lambda and 21 in the large subunit genes, such that the DNA from the left chromosome end is from 21, including cosB phi 21, the 1 gene, and the first 48 codons for the 2 gene. The rest of the hybrid 67 chromosome is lambda DNA, including 593 codons of the A gene. The chimeric gp2/A of hybrid 67 binds gp1 to form functional terminase.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1983

Structure of the bacteriophage lambda cohesive end site: location of the sites of terminase binding (cosB) and nicking (cosN).

The extents of the sites for nicking (cosN) and binding (cosB) of bacteriophage lambda DNA by terminase have been determined by studying cos cleavage and terminase binding in vitro. The cosN site is located in the segment from -22 to +24 bp (numbered from the center of the cohesive end sequence in the circular lambda genome). The cosB site is located in the segment from +51 to +120 (the +120 boundary determined by Miwa and Matsubara, 1983). Additional sequences are necessary for packaging into infectious phage particles, including regions to the left (Rz gene side) of cosN, and between cosN and cosB. Small deletions (7 and 11 bp) between cosN and cosB abolish packaging in vivo without affecting cos binding and cleavage in vitro, whereas a large deletion (26 bp) abolishes packaging in vivo and cleavage in vitro.

Bacteriophage lambda↗
PubMed1981

Loss of Treponema pallidum during incubation in Nelson's survival medium with or without serum added.

Treponema pallidum organisms suspended in equal parts of Nelson's survival medium alone and with addition of various sera were counted in 5 microliters samples before and after 18 hours' anaerobic incubation at 35 degrees C. Samples in which the treponemes were not Poisson-distributed were excluded from the study. A loss of greater than 30% occurred in 230 out of 391 samples. The disappearance of treponemes did not seem to be caused by treponemal agglutination during incubation. There was no adherence of treponemes to the formed elements remaining in the suspension. The loss was not dependent on the concentration of syphilitic serum, nor was it influenced by the presence of immobilizing antibody in the serum. Lack of rigorous anaerobiosis during the manipulations did not influence the treponemal loss. The loss was independent of the density of the treponemal suspensions which did not contain unheated guinea-pig serum (GPS). The relative frequency of the loss exceeding 30% was highest in suspensions containing unheated GPS. However, the extent of loss in individual samples was haphazardly distributed among suspensions of all the compositions examined. The loss of treponemes seems to depend on at least two factors: a) a factor which is eluted together with the treponemes from the syphilitic orchitis and b) the presence of active guinea-pig complement. It is conjectured that the complement is non-immunologically activated and acts through the alternative pathway.

Agglutination↗
PubMed1981

Management of gastrocolic fistula.

The authors present 13 patients with gastrocolic, gastrojejunocolic, or duodenocolic fistula, the majority of which were complications of peptic ulcer disease or its treatment. In contrast to previous reports, these patients were not severely anemic, dehydrated, or malnourished at time of presentation. Pain, fecal emesis, and diarrhea were the most common presenting symptoms. Half of the patients waited more than two weeks before seeking treatment. Barium enema and upper gastrointestinal series were equally useful in making the diagnosis in this study. When the patient was adequately prepared, one-stage operations could be performed safely in most situations. Operation may not be necessary or advisable in patients with metastatic malignant disease with minimal symptoms relating to fistulization.

Adult↗
PubMed1978

Statistical aspects of the treponemal counts in the TPI test.

A method of counting treponemes in randomly selected visual fields is described. It was found that Treponema pallidum is distributed as a Poisson distribution among the visual fields and also among samples drawn from the same suspension. Immobilized treponemes are binomally distributed among the total number of treponemes. Application of the parameters of the Poisson and the binomial distributions should be made in order to determine the dosage of T. pallidum in animal experimentation and to evaluate the outcome of the TPI test. Some statistical aspects of the investigation of treponemal survival are presented.

Probability↗
PubMedDate not supplied

Histologic consequences of inferior oblique anastomosis to denervated lateral rectus muscle.

Secondary muscular neurotization has been proposed as a means of restoring contractility to paretic extraocular muscle. We studied this technique by anastomosing healthy inferior oblique muscle to lateral rectus muscle that had been denervated either orbitally or intracranially in 20 dogs. Nerve and muscle fiber growth from the inferior oblique to the lateral rectus was demonstrated but no new neuromuscular junctions were formed. Regeneration of the lesioned sixth nerve occurred frequently and may explain the restoration of function claimed after this procedure.

Animals↗
PubMedDate not supplied

Fiber hypertrophy in rat extraocular muscle following lateral rectus resection.

Compensatory hypertrophy of muscle fibers occurs when tension on a skeletal muscle is increased. We looked for this phenomenon in response to strabismus surgery by performing a large right lateral rectus resection in 16 rats. Muscle fiber diameters of all horizontal rectus muscles were measured at 2-week postoperative intervals. Significant fiber hypertrophy occurred in both the antagonist right medial rectus and the resected right lateral rectus within 4 weeks. Fiber diameter subsequently returned to baseline in both muscles. We postulate that fiber hypertrophy in this setting may be a compensatory response to increased elastic load.

Animals↗