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Biomedical subjects

Jonas Magnusson

Publications and source records attributed to Jonas Magnusson.

6 recordsLinked to original sources

Surgery in Iceland.

Icelandic surgeons provide a wide range of modern surgical services with excellent results. How can a nation of fewer than 300,000 persons accomplish this? The main reasons are a thriving economy, a high standard of living and education, and the training of surgeons. All Icelandic surgeons receive their training overseas, many at university hospitals in the other Nordic countries, particularly Sweden. Others receive training in the United States and Great Britain. Almost 50% of the general and orthopedic surgeons hold PhD degrees from major universities in the Nordic countries. In some other surgical subspecialties, an even greater number possess a PhD degree. This diverse background of training creates a stimulating and international outlook among the surgeons. All types of surgery are performed in Iceland, with the exception of surgery for complicated congenital heart disease and transplantation. Recently a living related renal transplant program was started with promising results.

Biomedical Research↗

Tissue MicroArray analyses of pancreatic duodenal homeobox-1 in human cancers.

In previous studies, we demonstrated that rat insulin promoter (RIP)-driven gene therapy successfully targeted human pancreatic tumor PANC-1 cells and mouse insulinoma NIT-1 cells, which are both pancreatic duodenal homeobox-1 (PDX-1)-positive. The purpose of this study was to perform a human tissue array analysis to determine potential targets for RIP-driven gene therapy. A custom-designed tissue MicroArray analysis of various human cancer specimens was performed using a PDX-1 polyclonal antibody generated in our laboratory. The custom-designed Tissue MicroArray of human tumor specimens consists of human cancer specimens from different origins, such as the pancreas, breast, colon, prostate, kidney, liver, lung, and ovary. A panel of normal human specimens from 20 organs or tissues was used as a control. All tissues were fixed in formalin and embedded in paraffin. The immunohistochemistry studies of the cytoplasm and the nuclear expression levels were compared using the Loda method and blind reviews. Data are presented as the mean +/- SEM (p < 0.05 was considered significant by the unpaired student t-test). PDX-1 expression intensity was elevated in both benign and malignant tissues from the same patient with pancreas, breast, colon, prostate, and kidney cancers, whereas normal human tissues from control subjects without cancer did not express PDX-1. These results suggest that PDX-1 is an early marker for these cancers and could be potentially used as a diagnostic parameter and perhaps could be targeted by PDX-1-activated gene therapies, such as RIP-TK.

Adenocarcinoma↗

Histological subtyping and nuclear grading of renal cell carcinoma and their implications for survival: a retrospective nation-wide study of 629 patients.

OBJECTS: The aim of this study was to evaluate the prognostic significance of the current WHO histological subtyping and Fuhrman nuclear grading on the survival of patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: A retrospective population-based study was carried out on all patients with a histopathologically confirmed diagnosis of RCC in Iceland between 1971 and 2000. Fuhrman grade, TNM stage, and survival were evaluated and multivariate analysis applied in order to determine prognostic factors. RESULTS: Out of 629 patients (387 males, 242 females, mean age 64 years), 558 (88.7%) had clear cell, 53 (8.4%) papillary, and 13 (2.1%) chromophobe RCC. Patient demographics were comparable for the two major subtypes, but chromophobe RCCs were larger in size and were diagnosed at a younger age. Clear cell RCCs were more often of higher grades (G3+G4, 48.4%) and at advanced TNM stages (III+IV, 59.3%) than papillary RCCs (22.6% and 34% respectively, p<0.001). Linear regression analysis showed a strong correlation between grade, tumor size, and stage (p<0.001). Chromophobe RCCs had a better survival in univariate analysis than both papillary and clear cell RCCs (84.6% vs. 66.5% and 54.9% 5-year disease specific survival, p<0.001). However, in the multivariate analysis, only the patient's age, calendar year of diagnosis, TNM stage, and nuclear grade were independent prognostic factors of survival. CONCLUSION: In this complete nation-wide series nuclear grading is important in predicting survival of patients with RCC. It is strongly related to both tumor size and stage, with stage being by far the strongest prognostic factor. Different histological subtypes confer different survival. However, in spite of the distinctive cytogenetic and molecular characteristics of the subtypes, the survival difference is to a large extent due to differences in grade and particularly stage.

Adenocarcinoma, Clear Cell↗

Effect of incidental detection for survival of patients with renal cell carcinoma: results of population-based study of 701 patients.

OBJECTIVES: To conduct a population-based study to evaluate the effect of incidental detection of renal cell carcinoma (RCC) on survival. Incidental detection of RCC has increased significantly in recent years because of widespread use of abdominal imaging. The patients with incidentally diagnosed RCC have better survival; however, because of possible "lead time" bias and stage migration, the real implications of incidental detection on survival have been a matter of debate. METHODS: All living patients diagnosed with RCC in Iceland between 1971 and 2000 were included (n = 701). The histologic findings were verified, the stage (extent) of the disease was determined, and the incidence, mortality, and survival were evaluated. RESULTS: The strongest predictors of mortality were stage and nuclear grade. After correcting for these factors in the multivariate analysis, incidental diagnosis, histologic subtype, and gender lost their significance as independent prognostic factors of death. However, the incidentally diagnosed tumors were 2.3 cm smaller on average and at a lower stage and grade than symptomatic tumors, with significantly better patient survival than those with symptomatic tumors on univariate analysis (76% versus 44% 5-year disease-specific survival). An increased incidence of RCC was only seen in men, but incidental detection increased threefold during the study period in both sexes, with significant improvement in survival for the whole group as a result. CONCLUSIONS: The increased frequency of incidental detection has improved the survival of patients with RCC in Iceland. Incidental detection was not an independent prognostic factor of death, indicating that these tumors are of a similar biologic nature as symptomatic RCCs, only diagnosed earlier.

Aged↗

Renal oncocytoma: a clinicopathological analysis of 45 consecutive cases.

OBJECTIVE: To evaluate the clinical behaviour and pathology of renal oncocytoma in a well-defined population over a 30-year period. PATIENTS AND METHODS: In a retrospective population-based study we assessed relevant clinical and pathological factors in 45 patients (31 men and 14 women) diagnosed with renal oncocytoma in Iceland between 1971 and 2000. Clinical presentation, pathology, survival and causes of death were evaluated. RESULTS: The age-standardized incidence was 0.3 per 100,000 per year for both men and women, the incidence of oncocytomas being 5.5% of renal cell carcinomas (RCCs) diagnosed during the same period in Iceland. Fourteen patients were diagnosed at autopsy for an unrelated disease. Of 31 living patients (mean age 70.5 years), seven were diagnosed incidentally (23%), and the others had presented with haematuria (32%), abdominal pain (29%), and weight loss (10%). All the patients had a radical nephrectomy, except for one with bilateral oncocytoma who had a partial nephrectomy. The mean (range) tumour size was 5.7 (0.9-12) cm. Eighteen patients (58%) were diagnosed at Tumour-Node-Metastasis stage I, 10 at stage II (32%) and three at stage III (10%), all of those at stage III having renal capsular penetration or tumour invasion into perirenal fat tissue (T3aN0M0). No patients were diagnosed with lymph node or distant metastasis. Two cases of coexisting RCC were detected. After a median follow-up of 8.3 years there were no recurrences or deaths from oncocytoma (100% disease-specific survival). The overall 5-year survival was 63%, with most patients dying from cardiovascular diseases or nonrenal cancers. CONCLUSIONS: In most cases renal oncocytoma behaves like a benign tumour; the long-term prognosis is excellent. Thus, in the present patients, radical nephrectomy could be regarded as an over-treatment and nephron-sparing surgery as more appropriate, especially in patients with small tumours. However, both coexisting RCC and perirenal fat invasion, a hallmark of malignant behaviour, might indicate that more radical surgery is warranted in some of these patients.

Adenoma, Oxyphilic↗

Stomach cancer.

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Adenocarcinoma↗