Biomedical subjects

N R Christensen

Publications and source records attributed to N R Christensen.

6 recordsLinked to original sources

PubMed2000

Effect of photodynamic therapy on a heterotransplanted human parotid tumor.

To evaluate the effect of photodynamic therapy on human parotid tumors we used tumor specimens obtained from parotid surgery on a consecutive group of patients. The tumors were transplanted into a subcutaneous pocket of nude mice. The original human tumors were pleomorphic adenoma (four), adenolymphoma (one), acinic cell carcinoma (one), sarcoma (one) and low-grade adenocarcinoma (one). The most aggressive growth was seen in the low-grade adenocarcinoma. We re-implanted this tumor on ten mice bilaterally, and treated the tumors with photodynamic therapy (PDT), resulting in a mean depth of tumor necrosis of 5.4 mm (1-10 mm). In three cases we found vital tumor cells in the periphery of the tumor after treatment, with several new blood vessels in the surrounding tissue, indicating a great potential for neo-angiogenesis in this tumor. In order to evaluate the possible nerve damage subsequent to the photodynamic therapy, the ischiadic nerve in 24 lower limbs of nude mice were investigated. In one case only the macroscopical and histological investigation revealed signs of nerve damage. The current study demonstrates that the nude mice implantation model is excellent to investigate growth in both malignant and benign parotid tumors, and to test new therapeutic modalities. Photodynamic therapy seems to have a possible role in the future management of the malignant lesions of the parotid gland, in cases where radical surgery for some reason is not achievable.

Animals↗

PubMed1999

[Treatment of malignant parotid tumors. Results from the county of Copenhagen].

Out of 494 parotid gland tumours treated in Copenhagen county (population 600,000 inhabitants) in the period 1986 to 1995, 50 patients (tumours) were proven to be malignant, making an incidence of 0.62/100,000 per year. Age ranged between 14 and 87, mean 64 years. According to the UICC classification system, six tumours (12%) were classified as stage I, 23 (46%) as stage II, 14 (28%) as stage III and 7 (14%) in stage IV. Four therapeutic modalities were applied: surgery only, surgery + radiation, surgery + chemotherapy and surgery + chemotherapy + radiation. Surgical radicality was achieved in 76% and radicality was unrelated to tumour histology. Normal or nearly normal facial nerve function (HB1&2) was noted at last follow up in 60%. Five year crude survival for all patients were 68%. Survival was not depends on N-classification. Patients in stage I had a better survival compared to patients in stage II, III and IV. No statistically significant difference in five year crude survival between the radically operated patients (n = 38) and patients with residual tumour (p = 0.27, log rank-test), (p = 0.48 chi2-test was found.

Adolescent↗

PubMed1999

[Results of bat ear surgery over a period of ten years].

A material of 286 patients or 545 ears submitted to operation for protruding ears operated by Stenströms and Nordzells surgical procedure over a period of ten years were reviewed retrospectively. One hundred and sixty-three patients were clinically investigated and interviewed. The mean observation time was eight years. Satisfactory results were obtained in 94% of the patients subjectively. Objectively there was a good result in 74% of the cases. Relatively few complications and reoperations occurred. However 20% of the patients interviewed had postoperative pain more than one year after the operation. The results of the operations are reviewed and discussed. There was no significant difference between the results of the surgical procedure a.m. Stenström and a.m. Nordzell.

Adolescent↗

PubMed1998

[Benign neoplasms in the parotid gland in the county of Copenhagen 1986-1995].

In a ten year period from 1986-95 433 patients were submitted to operation due to benign tumours in the parotid gland in Copenhagen County. In this study we made a retrospective analysis of the surgical outcome. The incidence was calculated to be 6.8 benign tumours in the parotid gland per 100,000 persons per year. The histological distribution showed a frequency of 54% pleomorphic adenomas, 28% adenolymphomas and 18% other tumours. In the observation period there was a 3% recurrence rate in our material, most frequently the pleomorphic adenoma. The risk of permanent damage to the facial nerve was 1% for severe injury and 3% for affection of the ramus marginalis. Frey's syndrome was present in 50% of the patients, moreover the syndrome was observed many years after surgery. The frequency rate reached its highest level about five years postoperatively.

Adenolymphoma↗

PubMed1998

[Cervical necrotizing fasciitis].

Cervical necrotizing fasciitis is a rapidly progressive infection that involves the superficial and deep cervical fascia. Underestimation of this severe neck infection can delay diagnosis and treatment of this often fatal disease process. Three new cases, all with mediastinitis and fatal outcome are presented. Early diagnosis, aggressive surgical treatment and antibiotic therapy is essential if the high mortality rate is to be brought down in the future.

Aged↗

PubMed1997

Parotidectomy. Preserving the posterior branch of the great auricular nerve.

The great auricular nerve is often sacrificed in superficial parotidectomy, even though its posterior branch often can be preserved. By cautious dissection of the great auricular nerve it is possible to preserve the posterior branch in 70.5 per cent of the operations. Ninety-five patients who had undergone superficial parotidectomy were included. A significantly higher number of patients had subjective sequelae if the posterior branch of the nerve had been cut, compared to the patients with a preserved nerve. A significantly higher rate of sensory morbidity was found if the nerve had been cut. In patients with a preserved posterior branch of the great auricular nerve there was no increase in other potential sequelae after parotidectomy. Therefore, this additional dissection should be considered, where appropriate, in routine parotid surgery.

Cheek↗