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Biomedical subjects

N Christensen

Publications and source records attributed to N Christensen.

At least 55 records · Page 3Linked to original sources
PubMed1980

Mid-trimester abortion by vaginal administration of 9-deoxo-16, 16-dimethyl-9-methylene-PGE2.

9-Deoxo-16, 16-dimethyl-9-methylene-PGE2 is a new prostaglandin analogue which is stable in suppository form. Estimates of potential for gastrointestinal side effects in monkey in vivo indicated that the frequency of diarrhea was low with retention of uterine stimulating potency. In the present study the effect of the compound on uterine contractility and its efficacy for cervical dilatation and for termination of pregnancy during the second trimester was evaluated in 89 women. The uterine stimulating potency of 9-deoxo-16, 16-dimethyl-9-methylene-PGE2 during mid-pregnancy following bolus intravenous injection or intravenous infusion was four to five times that of PGE2 alpha. Pretreatment with one single vaginal suppository containing 40 mg of the 9-methylene analogue resulted in dilatation of the cervical canal sufficiently to allow evacuation of the uterus without further dilatation in most patients in the 13th to 14th week of pregnancy. In more advanced pregnancies (15th to 24th week of gestation), 83 percent of the patients aborted following vaginal administration of 75 mg of the compound at 0 and 8 hours. All patients had aborted 42 hours after start of treatment if intramuscular injections of 15-methyl-PGE2alpha Tham were added after 24 hours. Both treatments were associated with a significantly lower frequency of gastrointestinal side effects than following vaginal administration of 15-methyl-PGF2alpha methyl ester. The incidence of temperature elevation on the other hand seemed to be higher.

16,16-Dimethylprostaglandin E2↗
PubMed1980

A comparison of two stable prostaglandin E analogues for termination of early pregnancy and for cervical dilatation.

Termination of pregnancy with prostaglandin E analogues is in general associated with a lower frequency of gastrointestinal side effects than if corresponding F analogues are used. Their clinical use has, however, been limited by stability problems. In the present study the efficacy of different dose schedules of two new stable E analogues for termination of early pregnancy and for preoperative dilatation of the cervical canal was evaluated in 389 women. In early pregnant patients, vaginal administration of 75 mg of 9-deoxo-16, 16-dimethyl-9-methylene PGE2 repeated after six hours or three intramuscular injections of 0.5 mg 16-phenoxy-omega-17, 18, 19, 20-tetranor PGE2 methyl sulfonylamide administered in three-hour intervals resulted in a complete abortion in 94 to 100 per cent of the patients. Both treatments were associated with a low frequency of side effects. The 9-methylene analogue had the advantage of causing less uterine pain than 16-phenoxy-omega-17, 18, 19, 20-tetranor PGE2 methyl sulfonylamide with the dose schedules used. Single vaginal administration of 30 mg of 9-deoxo-16, 16-dimethyl-9-methylene PGE2 and one intramuscular injection of 0.5 mg of the methyl sulfonylamide analogue 12 hours prior to vacuum aspiration were equally effective in dilating the cervix in late first trimester pregnant patients. For both compounds, the frequency of side effects were lower than that previously reported for different PGF analogues administered by non-invasive routes.

16,16-Dimethylprostaglandin E2↗
PubMed1980

Teratogenic effect of maternal alcohol consumption on the mouse fetus. a histological study.

During pregnancy C3H mice were solely kept on a 10 or 20% liquid supply. They had free access to solids. All animals, including a group of controls, were chloroformed on the 19th day of pregnancy and the fetuses were examined for growth retardation, intrauterine death and microscopic malformations. Among the animals given alcohol, we found a significantly raised incidence of malformations as well as a raised number of intrauterine deaths and significant growth retardation as compared to the control animals. At the same time we found a clear dose-effect relation. The malformations were localize to the facial skeleton, the CNS, the eyes and lungs.

Animals↗
PubMed1979

Evaluation and treatment of penetrating cervical injuries.

Because the serious nature of penetrating cervical injuries may not be readily apparent on initial evaluation, and since delay in treatment can result in serious complications, a systematic method of evaluation and routine exploration has been employed in treating these injuries. One hundred eighty-nine patients, 49 with gunshot wounds and 140 with stab wounds, were treated in this series. Arteriography was performed in 62 patients (33%) to detect vascular injuries and to aid in the planning of the operative approach in patients with high or low neck wounds. Arteriography was 98% accurate and changed the operative approach in 29% of the positive studies. Of the 154 explorations 72 were positive (47%). There were no deaths and only four complications in the group with negative explorations. The mortality rate for the series was 2.6%. We believe that angiography in selected patients and routine exploration of wounds penetrating the platysma can minimize morbidity and mortality in these injuries.

Adolescent↗
PubMed1979

Teratogenicity of intrauterine copper wire in mice. A histopathological study.

Immediately after the implantation of the fertilized ovum, on the 6th day of pregnancy a copperwire was placed in the right hand uterine section on pregnant C3H mice. The left section was similarly surgically traumatized in order to serve as a control. The mice were killed with chloroform on the 19th day of pregnancy and by means of a special histological screening technique the fetuses were examined with special reference to growth reduction, intrauterine fetal death and microscopic malformations. Differences in intrauterine fetal death were shown not to exist, nor was there any significant growth retardation in the copperwire containing uterine section. Certain microscopic defects were found with slightly increased incidence in the copper containing section, but the differences were not statistically significant.

Animals↗
PubMed1979

Experimental endocarditis in rabbits. 3. Significance of the proteolytic capacity of the infecting strains of Streptococcus faecalis.

Insertion of a polyethylene catheter into the left ventricle of the heart was used for regular establishment of sterile endocarditis, and bacterial endocarditis was established by injection of approximately 10(8) Streptococcus faecalis into the blood stream at the same time as removal of the catheter which had been in place for 3 days. 100 out of 102 rabbits died spontaneously of bacterial endocarditis. Evidence is produced that the host-parasite interaction is influenced by the proteolytic property of S. faecalis in this experimental model. Two distinct types of clinical course are described: 1) A predominantly acute and damaging illness, characterized by a high level of bacteraemia, small amounts of soft, friable vegetations in the left side of the heart, high frequency of kidney infarcts and shorter survival time in rabbits infected with proteolytic strains. 2) A relatively subacute illness, characterized by a lower level of bacteraemia, large, hard, non-friable vegetations on the aortic valves, less pronounced destructive changes in the substance of valve leaflets, relatively lower frequency of kidney infarcts and longer survival time in rabbits infected with non-proteolytic strains. The results suggest that proteolytic strains of S. faecalis cause partial dissolution of the vegetations resulting in a more severe clinical picture.

Animals↗
PubMed1978

Pleural effusion disease in rabbits. Histopathological observations.

Pleural effusion disease (PED) is a generalized infection of laboratory rabbits caused by an unidentified agent, believed to be a virus. The histopathological response of 17 rabbits infected experimentally with this agent was studied. The light microscopical changes were minimal and the most consistent findings were alterations of the lymphoid tissue. Fatal infections were characterized by a uniform reduction of the splenic white pulp, focal degenerative changes of the thymus and lymph nodes and probably slight proliferative changes of the kidney glomeruli. In surviving animals there were transient myocardial and hepatic lesions and, after clinical recovery, proliferative changes in spleen, lymph nodes, interstitial lung tissue and probably kidney glomeruli. The results do not permit any conclusions to be drawn regarding the aetiology or the pathogenesis of PED infection.

Animals↗
PubMed1978

Experimental endocarditis in rabbits. I. Technique and spontaneous course of non-bacterial thrombotic endocarditis.

Insertion of a polyethylene catheter into the heart was used for regular establishment of sterile endocarditis in 52 rabbits. The catheter was inserted with the aid of guide wire, and distance marking on the catheter was used to obtain precise positioning, so that the catheter was retained with the curved distal end inside the left ventricle of the heart. The results showed that the catheterization procedure could be carried out with a high degree of accuracy. Uniform localization of the vegetations was obtained, these reaching a suitable size of development in all rabbits after insertion of the catheter for 3 days. Histological examination of the sterile vegetation showed that catheter withdrawal at this time would still permit the regular development of an infection. After withdrawal of the catheter, the sterile vegetations rapidly decreased in size and disappeared almost completely by 10 days. Sterile endocarditis in rabbits induced by a catheter for a period of 3 days proved to be a harmless and self-limiting disease. The model presented seems to be suitable for futher investigations on experimental bacterial endocarditis.

Animals↗
PubMed1978

Experimental endocarditis in rabbits. 2. Course of untreated Streptococcus faecalis infection.

Insertion of a polyethylene catheter in the left side of the heart was used to induce sterile endocarditis in 34 rabbits. Bacterial endocarditis was established by injection of approximately 10(8) Streptococcus faecalis into the blood stream simultaneous with the removal of the catheter which had been in place for 3 days. The course of the bacterial endocarditis was examined by autopsy of rabbits sacrificed at regular intervals after the infection. The results showed that the presence of the catheter was not essential for the induction or maintenance of the infection. Growth of the bacteria took place in the preformed vegetations in the aorta, on the aortic valves and in the left ventricle. However, increases in the size of the vegetations, a high density of bacteria in the vegetations and secondary spreading were found only on the aortic valves. The extracardial manifestations of left-sided S. faecalis endocarditis included constant bacteriaemia, a high frequency of septic kidney infarcts and enlargement of the spleen. This form of experimentally provoked bacterial endocarditis in rabbits provides a good imitation of human subacute endocarditis, and would thus seem to be suitable for further study of the pathophysiology of endocarditis and evaluation of the effect of treatment with antibiotics.

Animals↗