Search PubMed⌕ Search

Biomedical subjects

P E Andersen

Publications and source records attributed to P E Andersen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Genetic polymorphisms in head and neck cancer risk.

OBJECTIVE: To assess whether genetic polymorphisms implicated as risk factors for other tobacco-associated malignancies are associated with altered risk of head and neck squamous cell carcinoma. DESIGN: Case-control study. SUBJECTS: One hundred sixty patients with head and neck squamous cell carcinoma recruited from a university-based head and neck oncology clinic and 149 population-based controls. METHODS: Genotyping of the CYP1A1 (Ile462Val), GSTM1 (null), GSTP1 (Ile105Val), GSTT1 (null), and P53 (Arg72Pro) genes was performed by polymerase chain reaction-based techniques on DNA prepared from peripheral blood. In addition, a questionnaire was used to collect demographic information from each subject. RESULTS: Cases were significantly older (p <.0001) and had significantly greater tobacco use (p <.0001) and were more likely to be male (p <.0001) than were control subjects, thus confirming known risk factors for this disease. When cases and controls were compared by simple chi-square analysis, only the frequency of CYP1A1 (Ile462Val) polymorphism was significantly different between cases and controls (OR =.42; 95% CI =.18-.99; p <.04). However, with a logistic regression model to control for known risk factors, we were unable to demonstrate a significant association with head and neck cancer for any of the polymorphisms tested, including CYP1A1. CONCLUSIONS: This population fails to identify a relationship between the above-mentioned polymorphisms and head and neck cancer.

Carcinoma, Squamous Cell↗
PubMed2000

The relative value of fine-needle aspiration and imaging in the preoperative evaluation of parotid masses.

BACKGROUND: To establish the sensitivity, specificity, and accuracy of imaging and fine-needle aspiration (FNA), alone or in combination, in distinguishing benign from malignant histologic findings for parotid lesions. METHODS: Retrospective blinded review of preoperative imaging and FNA studies of parotid masses and comparison with histologic findings after excision. RESULTS: Forty-eight patients were identified (13 with CT, 35 with MRI); 23 (48%) of the lesions were malignant, 25 (52%) were benign. MRI, CT, and FNA misclassified 17%, 46%, and 21% of the lesions, respectively. The sensitivity/specificity/accuracy of these tests for detecting malignant lesions were as follows: MRI (88%,77%,83%), CT (100%,42%, 69%), and FNA (83%,86%,85%) and were not significantly different. Combinations of imaging and FNA were not significantly better in detecting malignancy. CONCLUSIONS: Imaging and FNA are comparable in their ability to correctly identify malignant parotid lesions preoperatively. Combining these two modalities yields no advantage in terms of specificity, sensitivity, or accuracy of a malignant diagnosis.

Biopsy, Needle↗
PubMed2000

Prevalence of pulmonary arteriovenous malformations (PAVMs) and occurrence of neurological symptoms in patients with hereditary haemorrhagic telangiectasia (HHT).

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease. HHT is characterized by a wide variety of clinical manifestations, including pulmonary arteriovenous malformations (PAVMs) and neurological symptoms. OBJECTIVE: To estimate (i) the prevalence of PAVM, and (ii) the occurrence of neurological symptoms in a geographical well-defined population of HHT patients. METHODS: HHT family members were invited to a clinical examination including registration of HHT manifestations, screening for pulmonary arteriovenous malformations and neurological evaluation. Two groups served as controls: (i) first-degree relatives without any signs of HHT; and (ii) age- and gender-matched controls. SETTING: Odense University Hospital. SUBJECTS: HHT patients identified in a cross-sectional family survey carried out in the County of Fyn, Denmark. RESULTS: Included in the study were 169 HHT family members representing 24 families. They included both HHT patients and their first-degree relatives. The criteria of HHT were fulfilled in 75 participants; of these, 59 had a screening procedure performed, and PAVMs were demonstrated at pulmonary angiography (PA) in 18. Seven of the HHT patients had a history of cerebral stroke, compared with none of their healthy first-degree relatives. CONCLUSION: The prevalence of PAVM was 24% amongst HHT patients. The study confirmed an increased prevalence of neurological symptoms amongst HHT patients; the odds ratio was estimated to be 7.6. In order to enable prevention of these complications, screening for PAVM should become an integral part of the medical care for HHT patients.

Adult↗
PubMed2000

External beam radiation followed by planned neck dissection and brachytherapy for base of tongue squamous cell carcinoma.

BACKGROUND: Surgical resection of tongue base cancer can leave the patient with significant functional deficits. Other therapies, such as external beam radiation followed by neck dissection and radiation implants, have shown equal tumor control with good functional outcome. METHODS: Between March 1991 and July 1999, 12 patients at Oregon Health Sciences University, the Portland Veterans Administration Medical Center and West Virginia University School of Medicine Hospital were treated with external beam radiation followed by neck dissection and Ir192 implants. Two patients had T1 disease, two had T2, five patients had T3 tumors, and three had T4 tumors. Six had N2a necks, three had N2b necks, and three had N2c. Follow-up ranged from 13 months to 8 years. RESULTS: After external beam radiation, five patients had complete response and seven had partial response in the neck without complications. One patient underwent a unilateral radical neck dissection, eight had unilateral selective neck dissections involving levels I to IV, and three had dissections involving levels I to III. One of the five patients who had a complete clinical response in the neck had pathologically positive nodes. One patient had a pulmonary embolus that was treated and had no permanent sequelae. There were three complications from brachytherapy. Two patients had soft tissue necrosis at the primary site and one patient had radionecrosis of the mandible. All healed without further therapy. One patient had persistent disease and underwent a partial glossectomy but died of local disease. Distant metastasis developed in two patients. All others show no evidence of disease and are able to eat a normal diet by mouth. CONCLUSION: This combination of therapies should be considered when treating tongue base cancer.

Aged↗
PubMed2000

Analysis of optical coherence tomography systems based on the extended Huygens-Fresnel principle.

We have developed a new theoretical description of the optical coherence tomography (OCT) technique for imaging in highly scattering tissue. The description is based on the extended Huygens-Fresnel principle, valid in both the single- and multiple-scattering regimes. The so-called shower curtain effect, which manifests itself in a standard OCT system, is an inherent property of the present theory. We demonstrate that the shower curtain effect leads to a strong increase in the heterodyne signal in a standard OCT system. This is in contrast to previous OCT models, where the shower curtain effect was not taken into account. The theoretical analysis is verified by measurements on samples consisting of aqueous suspensions of microspheres. Finally, we discuss the use of our new theoretical model for optimization of the OCT system.

Models, Theoretical↗
PubMed2000

Closed-form solution for the Wigner phase-space distribution function for diffuse reflection and small-angle scattering in a random medium.

Within the paraxial approximation, a closed-form solution for the Wigner phase-space distribution function is derived for diffuse reflection and small-angle scattering in a random medium. This solution is based on the extended Huygens-Fresnel principle for the optical field, which is widely used in studies of wave propagation through random media. The results are general in that they apply to both an arbitrary small-angle volume scattering function, and arbitrary (real) ABCD optical systems. Furthermore, they are valid in both the single- and multiple-scattering regimes. Some general features of the Wigner phase-space distribution function are discussed, and analytic results are obtained for various types of scattering functions in the asymptotic limit s >> 1, where s is the optical depth. In particular, explicit results are presented for optical coherence tomography (OCT) systems. On this basis, a novel way of creating OCT images based on measurements of the momentum width of the Wigner phase-space distribution is suggested, and the advantage over conventional OCT images is discussed. Because all previous published studies regarding the Wigner function are carried out in the transmission geometry, it is important to note that the extended Huygens-Fresnel principle and the ABCD matrix formalism may be used successfully to describe this geometry (within the paraxial approximation). Therefore for completeness we present in an appendix the general closed-form solution for the Wigner phase-space distribution function in ABCD paraxial optical systems for direct propagation through random media, and in a second appendix absorption effects are included.

Journal Article↗
PubMed2000

Mutagen sensitivity and environmental exposures as contributing causes of chromosome 3p losses in head and neck cancers.

The interaction between environmental exposures and host susceptibility may lead to specific mutational events within head and neck squamous cell carcinoma (HNSCC). Furthermore, this interplay may determine not only the probability of cancer development but also the biologic characteristics of the tumor once it occurs. To better understand the relationship of mutagen sensitivity and tobacco and/or alcohol consumption on HNSCC carcinogenesis, we examined loss of heterozygosity on chromosome 3p in 58 HNSCCs using 10 microsatellite markers. Mutagen sensitivity was determined in vitro by quantitating bleomycin-induced chromatid breaks utilizing peripheral blood lympocytes from respective patients. Forty-six of the 58 invasive cancers showed allelic loss at one or more loci. Consistent with previous investigations, three discrete regions of deletions were identified: 3p13-14.2, 3p21.1-21. 2, and 3p25.1-26.1. The frequency and types of deletions were dependent upon tobacco and alcohol exposures. The distal region of 3p but not the remaining two regions was most frequently influenced by tobacco exposure. In contrast, heavy alcohol use when combined with tobacco use was associated with whole-arm loss of 3p rather than identifiable site-specific damage. Furthermore, this combined influence of alcohol and tobacco exposures on whole-arm loss was most apparent in those patients who expressed mutagen-sensitivity; the odds ratio of whole-arm loss increasing from 2.67 (95% CI 0. 21-33.49) in those individuals who were mutagen resistant to 13.5 (95% CI 1.3-136.0; P = 0.02 by Fisher's exact test) in those who were mutagen sensitive. An assessment of clinical parameters in this population demonstrated that patients with whole-arm loss were more likely to present with cervical lymph node metastases and advanced stage disease than patients with partial losses. Results indicate that various environmental exposures as well as the expression of mutagen sensitivity will influence the types of chromosome 3p allelic losses in head and neck cancers as well as the behavior of disease once it develops.

Alleles↗
PubMed1999

[Percutaneous transluminal embolization in arterial retroperitoneal traumatic hemorrhage].

This study presents three cases of uncontrollable retroperitoneal arterial haemorrhage diagnosed by angiography and treated by transluminal embolization with coils. The haemorrhage originated in one patient from a branch of the internal iliac artery and in the other two patients from a renal artery. The circulation was stabilized in all three patients after transluminal coil embolization proximal to the arterial lesions. One patient died of multiorgan failure due to prolonged uncontrolled haemorrhage before embolization and one patient died as a consequence of low haemoglobin due to religiously based rejection of blood transfusion. Trauma patients with uncontrollable haemorrhage and retroperitoneal haematoma should be suspected of an arterial lesion and as early as possible be transferred to a center with experience in catheterisation and transluminal embolization.

Aged↗
PubMed1999

Pulmonary arteriovenous malformations: screening procedures and pulmonary angiography in patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited disease with a high prevalence of pulmonary arteriovenous malformations (PAVMs). The first symptom of HHT may be stroke or fatal hemoptysis associated with the presence of PAVM. OBJECTIVE: To evaluate different screening methods applied for the identification of PAVMs. SETTING: Odense University Hospital. SUBJECTS: HHT patients with positive findings on contrast echocardiography (CE) who participated in a screening investigation and underwent pulmonary angiography (PA). METHODS: Different screening methods were evaluated against the results of PA. In a group of patients with positive findings on CE, we compared results of PA with the following: severity of dyspnea; results of pulse oximetry arterial oxygen saturation (SaO2) supine and upright; supine PaO2 in room air and while breathing 100% oxygen; size of arteriovenous shunt in supine position; chest radiograph; and intensity of contrast at CE. RESULTS: PA was performed in 25 HHT patients with positive findings on CE, 15 of whom had PAVM. Embolization therapy was recommended in 12 patients, and 3 patients had small PAVMs not accessible for therapy. In 10 patients, PAVM could not be demonstrated at PA. The sensitivity and specificity calculated for the screening procedures are as follows: 53% and 90%, respectively, for SaO2; 60% and 100%, respectively, for chest radiograph; 73% and 80%, respectively, for PaO2 in room air; 100% and 40%, respectively, for PaO2 breathing 100% oxygen; and 64% and 80%, respectively, for shunt measurement. CONCLUSION: Initial screening with CE followed by measurement of PaO2 while breathing 100% oxygen seemed to be the best screening procedure for identification of patients with PAVM. Screening with chest radiograph and pulse oximetry was shown to be insufficient.

Adult↗
PubMed1999

Chest roentgenogram in the evaluation of heart defects in asymptomatic infants and children with a cardiac murmur: reproducibility and accuracy.

OBJECTIVES: To evaluate the reproducibility and the accuracy of pediatric radiologists' assessments of chest radiographs with respect to the presence or absence of heart defects in children with an asymptomatic heart murmur. DESIGN: Ninety-eight children, ages 1 month to 15 years (median, 30.1 months), referred for evaluation of a heart murmur were consecutively included. They all had a standard chest radiograph and a color Doppler echocardiograph (CDE) performed. Six specialists in pediatric radiology evaluated the chest radiographs independently on two occasions 6 months apart. The radiologists were asked to classify each set of films into one of two categories: heart disease or no heart disease. The outcome of the CDE was considered the definite diagnosis. kappa statistics were used to analyze the reproducibility of the radiologic assessments. Sensitivity, specificity, and the predictive value of a positive and a negative test were used for evaluation of the accuracy of the radiologic assessments. RESULTS: Mean intra- and interobserver kappa values were all <0.6, and the majority were <0.4. Mean sensitivity was 0.3 (range: 0.17-0.52), mean predictive value of a positive test was 0.4, implying that 60% of the positive assessments were falsely positive. Mean specificity was 0.86 (range: 0.75-0.93) and the mean predictive value of a negative test was 0.80 implying that 20% of the negative assessments were falsely negative. CONCLUSION: We found a low reproducibility, as well as a low accuracy, of the radiologic assessments of the chest radiographs of children with an asymptomatic heart murmur with respect to the presence or absence of heart disease. A false-positive radiologic assessment of the chest radiograph with respect to heart defects causes unnecessary anxiety and further examinations, whereas a false-negative assessment might result in omission of relevant investigations and proper identification of the heart defect. We cannot recommend the use of chest radiographs in the initial evaluation of the asymptomatic child with a heart murmur. If a heart defect cannot be excluded by clinical examination a CDE must be performed.

Adolescent↗
PubMed1998

[Percutaneous transluminal embolization of pulmonary arteriovenous malformations].

A series of nine patients with pulmonary arteriovenous malformations (PAVM) treated with embolotherapy at Odense University Hospital is presented. In all patients the arterial oxygen tension increased after embolisation. PAVM causes right-to-left shunting, which may result in severe hypoxaemia, and, due to lack of the normal filter function of the lung, paradoxical embolism. Women are particularly at risk during pregnancy. Among patients with Hereditary Haemorrhagic Telangiectasia 15-33% also have PAVM. Embolotherapy is a safe and efficacious treatment for occlusion of PAVM. Since serious complications to the disease can be prevented, all HHT patients should be offered screening for PAVM, and treated if required.

Adult↗
PubMed1998

Multiple anomalies, hypokalaemic paralysis and partial symptomatic relief by terbutaline.

In this paper a follow-up is presented of a case report initially described by Andersen in 1971. The patient presented with a syndrome including elements of familial periodic paralysis with hypokalaemia, long QT syndrome, ventricular ectopy, myopathy with fibre-type disproportion and dysmorphic features resembling Treacher Collins' syndrome. The main symptom was hypokalaemic paralysis. The episodes were accompanied by a lowered intracellular potassium content and an increase in intracellular sodium. Treatment with terbutaline, a Na/K-ATPase-stimulating drug, resulted in attack-free periods of approximately 9 months, after which the attacks reoccurred. The patient suffered severe attacks whenever treatment with terbutaline was stopped. The patient experienced two attacks of respiratory arrest, the second being fatal.

Abnormalities, Multiple↗
PubMed1998

The Barath Cutting Balloon versus conventional angioplasty. A randomized study comparing acute success rate and frequency of late restenosis.

In a randomized multicenter study initial success rate and 6 months' follow-up were compared between coronary angioplasty performed with the Barath Cutting Balloon (group A, n = 32) and conventional balloons (group B, n = 32) in patients with type A or B lesions in native coronary arteries. The culprit lesion was not reached in one patient in group A. Initial success rates were similar with and without additional stenting (8 in group A and 10 in group B). Angiographic follow-up data (in 95%) revealed a non-significant improvement in minimal lumen diameter, diameter stenosis in group A. Restenosis developed in 16.7% of group A vs 25.8% of group B, (p = 0.57). A separate analysis of stented patients showed no restenosis in group A and restenosis in 4 out of 10 patients in group B (p = 0.10). A possible beneficial effect of the Cutting Balloon with respect to in-stent restenosis requires further studies.

Aged↗
PubMed1998

Nodal disease in purely glottic carcinoma: is elective neck treatment worthwhile?

OBJECTIVE: Although there is a generalized understanding of the relatively low overall incidence of nodal disease from purely glottic carcinoma, the exact role for elective neck treatment in the management of this disease remains controversial. The purpose of this study was to identify the incidence of occult nodal disease (including paratracheal) in patients who have glottic carcinoma without significant extraglottic extension and to identify which patients are at risk for this. A retrospective chart review of 92 such patients who had either undergone neck dissection or been observed for a minimum of 2 years was performed. RESULTS: For the 92 patients, neck treatment consisted of observation in 68 patients, paratracheal node dissection in four, unilateral neck dissection in four, unilateral neck dissection and excision of paratracheal nodes in 14, and bilateral neck dissection with paratracheal node excision in two. Of the 24 nodal dissections performed, four were positive for occult metastatic disease. No patient in the observation group developed nodal disease. CONCLUSION: The incidence of occult nodal disease in NO glottic carcinoma is low, 0% in early stage disease (T1-T2) and 19% in late stage disease (T3-T4). Nodes at highest risk included only the paratracheal, level II, and level III. Elective neck treatment should only be undertaken for advanced (T3-T4) disease and even then is of questionable benefit. If undertaken, it should have a low potential morbidity, such as selective neck dissection or radiation. Computed tomography was not useful in staging the neck for this subset of patients.

Adult↗
PubMed1998

Embolotherapy for pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome).

PURPOSE: To evaluate the clinical results of embolization of pulmonary arteriovenous malformations (PAVMs) in patients with hereditary hemorrhagic telangiectasia (HHT), the Rendu-Osler-Weber syndrome. MATERIAL AND METHODS: Twelve patients in the county of Fyn, Denmark, were treated with transcatheter embolization of 20 PAVMs using 12 detachable silicone balloons and 26 steel coils. RESULTS: All PAVMs were completely occluded and we observed a significant rise in PaO2 after treatment and a significant decrease in right-to-left shunt estimated by contrast echocardiography. All patients experienced an improved functional level. One patient experienced severe pleurisy and another a rise in temperature following treatment, but otherwise no symptomatic complications were observed. CONCLUSION: Embolotherapy is a definitive treatment for PAVMs: it is very effective with a high success rate and few complications. Patients with HHT are at risk of PAVM and should be screened and treated for PAVMs when these reach a size that is associated with complications. In the detection of PAVMs, contrast echocardiography is a very sensitive method, and follow-up of these patients can be done with contrast echocardiography.

Adult↗
PubMed1997

[Arterial diagnostics].

Explore the source record for details and available documents.

Angiography, Digital Subtraction↗
PubMed1997

[Internal carotid artery stent].

Stent implantation is a well established treatment of vascular stenoses if the result after percutaneous transluminal angioplasty (PTA) is suboptimal, or as a primary treatment to reduce the number of restenoses. Carotid artery stents have only been used in a relatively limited number of cases up till now. The first Scandinavian case of a successful internal carotid artery stent implantation after suboptimal PTA with five months follow-up is presented.

Aged↗