Biomedical subjects

S Kristensen

Publications and source records attributed to S Kristensen.

At least 37 records · Page 2Linked to original sources

PubMed1996

Ultrasonographically guided fine-needle aspiration biopsy of intrathoracic tumors.

PURPOSE: Evaluation of diagnostic accuracy and complication frequency at ultrasonographically guided fine-needle aspiration biopsy of intrathoracic tumors. MATERIAL AND METHODS: A total of 134 ultrasonographically guided percutaneous fine-needle aspiration biopsies were performed on 128 patients with intrathoracic tumors abutting on the pleura. A cytologic diagnosis was obtained in 119 patients (93%). RESULTS: In 83 patients, cytologic malignancy was found; in 34, benignity; and in 2, cellular atypia. A total of 117 diagnoses were correct and 2 diagnoses were false-positive. A malignancy subtyping based on the cytologic aspirates was made in 80 patients. In 40 (93%) of 43 histologically proven subtypes, the subtyping was correct. The complication frequency in terms of pneumothorax was 3.7%. CONCLUSION: Ultrasonographically guided percutaneous fine-needle aspiration biopsy is a safe and reliable method of establishing the cytologic diagnosis of intrathoracic tumors.

Biopsy, Needle↗

PubMed1995

Polypoidal carcinosarcoma of the oropharynx: a clinicopathological and immunohistochemical study.

Polypoidal squamous cell carcinomas, with a sarcomatous stroma, in the upper aerodigestive tract are very rare but well described tumours. They are associated with a multifarious nomenclature because of different opinions regarding their histology and histogenesis. The main issue is whether the stroma component is a true sarcoma or a benign reactive lesion. In order to draw the attention of otolaryngologists and pathologists to the characteristic features of this rare tumour, two cases originating from the oropharynx are presented. Both tumours were pedunculated and polypoidal, and their bulk consisted of a bizarre sarcoma-like stroma covered with granulation tissue. In some areas of the surface, however, atypical squamous cell epithelium with foci of invasive carcinoma was found. In the vicinity of the latter both tumours contained areas of adenocarcinoma. After surgical excision followed by radiation therapy, there was no recurrence after two and five years, respectively. The histological and immunohistochemical findings support the assumption that these two tumours are carcinosarcomas. Adenocarcinomatous elements in this type of tumour have to our knowledge been reported only twice previously and have never been observed in the pharynx.

Adenocarcinoma↗

PubMed1995

Mediastinal staging of lung cancer. Is mediastinoscopy still essential?

The significance of computed tomography of the thorax and mediastinoscopy in pretherapeutic mediastinal assessment for the staging of lung cancer remains controversial. The presents study was designed to establish a standard approach to cervical mediastinoscopy for otolaryngologists, who in Denmark traditionally are involved in the staging of non-small cell lung cancer. Sixty-four potentially operable patients with non-small cell lung cancer underwent thoracic computed tomography prior to bronchoscopy and cervical mediastinoscopy. Thirty-six of the 43 mediastinoscopically negative patients additionally underwent thoracotomy, which in 32 cases was considered curative. Mediastinoscopy alone established the lung cancer diagnosis in 20% of the patients. In diagnosing lymph node metastases in the superior mediastinum, a criterion of 10 mm for abnormal enlargement resulted in an overall sensitivity and specificity of mediastinal computed tomography of 72% and 85%, respectively, and the overall false-negative and false-positive rates appeared to be 18% and 25%, respectively. No clinicopathological characteristics could be identified that influenced the occurrence of mediastinal metastases or the accuracy of computed tomography. It is concluded that mediastinoscopy remains essential in the evaluation of patients with presumed or verified non-small cell lung cancer. For otolaryngologists, the strategy of routine cervical mediastinoscopy, performed under general anesthesia in the same procedure as bronchoscopy, is advocated as a standard approach to preoperative mediastinal assessment for the staging of non-small cell lung cancer.

Adult↗

PubMed1995

Photoreactivity of biologically active compounds. VIII. Photosensitized polymerization of lens proteins by antimalarial drugs in vitro.

The drugs commonly used in the treatment of malaria are photochemically unstable. Several of these compounds cause dermal and ocular toxic reactions that may be light induced. The in vitro photopolymerization of calf lens proteins in the presence of antimalarial drugs was studied as part of a screening of the photochemical properties and phototoxic capabilities of these compounds. The pseudo-first-order rate constant for the reaction was calculated, and related to the amount of light absorbed by the compounds in order to determine the relative photosensitizing effect of each drug. The reaction mechanisms were evaluated by adding a variety of quenchers to the reaction medium during irradiation. Based on the results obtained in this study and previous knowledge about the pharmacokinetic behavior of these compounds, several of the drugs investigated have to be considered as potential photosensitizers in the human lens, the retina and the skin.

Animals↗

PubMed1994

Photoreactivity of biologically active compounds. VII. Interaction of antimalarial drugs with melanin in vitro as part of phototoxicity screening.

The drugs commonly used in the treatment of malaria are photochemically unstable. Several of these compounds accumulate in melanin-rich tissues and cause toxic reactions which may be light induced. As part of the screening of the photochemical properties and phototoxic capabilities of antimalarials, the in vitro interaction of eight antimalarials with melanin was studied. The dissociation constant for the drug-melanin complex and the relative number of binding sites on melanin were estimated for six of the drugs using a curve-fitting program. The reaction rate for the formation of the melanin-drug complex was determined, and the complexes were further characterized by zeta potential measurements.

Antimalarials↗

PubMed1993

The effect of budesonide (Rhinocort) in the treatment of small and medium-sized nasal polyps.

The objectives of this study were to determine if the size of nasal polyps could be assessed in a reproducible way and to study the effect of budesonide in patients suffering from eosinophilic nasal polyposis with small and medium sized polyps. Ninety-one patients entered the study. Budesonide 200 micrograms b.i.d. (aerosol or aqua) and placebo (aerosol or aqua) were compared in a 3-month double-blind, multi-centre, randomized study. Efficacy was measured by an assessment of polyp size, nasal peak-flow index and the patient's assessment of nasal symptoms. The conclusions were that the size of polyps could be assessed in a reproducible way, and that budesonide delivered either as a water-based suspension or as an aerosol is effective in the treatment of patients with small and medium sized polyps.

Administration, Topical↗

PubMed1992

[Emphysematous pyelonephritis].

A case of emphysematous pyelonephritis (EPN) is described. EPN is a severe suppurative infection of the renal parenchyma and the perirenal tissue, characterized by intra-renal, and possibly perirenal, gas formation. This is a rare form of acute pyelonephritis. The condition is associated with a high mortality. Diabetic patients are particularly prone to the disease. The diagnosis is established with great certainty by computed tomography of the kidneys. The condition should be treated with an intensive combined medical-urological regimen with percutaneous nephrostomy guided by computed tomography or ultrasound should be performed. If no therapeutic response occurs, surgical incision and drainage or nephrectomy are recommended. In the present case of EPN, the medical treatment proved adequate.

Emphysema↗

PubMed1992

Spontaneous healing of traumatic tympanic membrane perforations in man: a century of experience.

Widespread controversy exists concerning the treatment of traumatic tympanic membrane perforations. To elucidate the issue, a reference value for the rate of spontaneous tympanic membrane closure in man, to which the healing rates following different techniques of early surgical repair should be compared, was established on the basis of a review of more than 500 texts covering a century's literature on the traumatically perforated tympanic membrane. The spontaneous healing rate appeared to be close to 80 (78.7 per cent) in 760 evaluable cases of traumatic tympanic membrane perforations of all sorts diagnosed within 14 days post injury. A relative, causal-related variation of spontaneous healing could be demonstrated, and a pathogenetic classification of direct traumatic tympanic membrane perforations into ruptures induced by air-pressure changes, heat or corrosives, solids, and water pressures, is of proved clinical value and may have medico-legal validity. There is an obvious need for clinically controlled studies on the spontaneous healing of all kinds of traumatic perforations of the tympanic membrane in humans, and important elements in the design of future studies are advocated.

Humans↗

PubMed1992

Nasal packing and nocturnal oxygen desaturation.

Nasal obstruction influences respiration during sleep, and nasal packing may be the cause of obstructive sleep apnoea. In order to investigate this phenomenon, perioperative nocturnal oxygen saturation was monitored for 3 nights with continuous, non-invasive pulse oximetry in 12 patients who had total nasal packs after septoplasty. Significant extension of nocturnal accumulated time of oxygen saturation less than 90% was demonstrated both during the first and second postoperative nights. The clinical significance of these results is as yet unknown, but the use of partial nasal packing in association with septoplasty is advocated and further investigations on nocturnal oxygen saturation are called for.

Adolescent↗

PubMed1992

Origins of BCG surface charge: effect of ionic strength and chemical modifications on zeta potential of Mycobacterium bovis BCG, Tice substrain, cells.

The zeta potential of washed Tice substrain BCG organisms was measured over a range of ionic strengths from I = 0.005 to 0.1 M. No change in the isoelectric point of 3.4-3.7 was evident. Proteolytic enzymes (trypsin/chymotrypsin, pepsin, papain and pronase) and fluorodinitrobenzene abolished the cationic charge, suggesting that this is substantially due to amino groups associated with protein. Neither hot HCI nor cold trichloroacetic acid affected the charge, indicating that ionic groups are not associated with extractable polysaccharides. Methanolysis, treatment with HF and carbodiimide, and cationic detergent (cetyltrimethylammonium bromide) binding indicated that the negative charge was provided by carboxylic acids, phosphoesters and strong acidic groups, possibly sulphates. Standardless quantitative X-ray microanalysis revealed the presence of phosphorus and sulphur on the surface of actively growing BCG colonies.

BCG Vaccine↗

PubMed1992

Muscular hamartoma of the breast. A case report.

A case of a muscular hamartoma of the breast in a 47-year-old woman is presented. Tumors containing smooth muscle are rare in the breast. Radiologically it appears as a circumscribed tumor with homogeneous or varying density. Histologically these lesions are composed of ducts, lobules, stroma prominently adipose, and smooth muscle.

Breast Neoplasms↗

PubMed1992

The peak flow nasal patency index.

The peak flow nasal patency index (NPI) is the ratio between the nasal and oral peak airflow. This index was found to be a good indicator of nasal patency present in 24 patients following septoplasty and indicated significant improvement postoperatively. The peak flow nasal patency index was also correlated to self-assessment scores of nasal function in each patient. In this latter study, a low index correlated to a high self-assessment score, both of which indicated poor nasal patency. Our studies have shown that the peak flow nasal patency index is a useful measure for determining nasal patency, particularly for defining the results of any applied therapies.

Adolescent↗

PubMed1991

[Malignant tracheal tumor--differential diagnosis in bronchial asthma].

Primary tumours of the trachea are rare and most of the symptoms relate to obstruction of the air passage leading to inspiratory and expiratory stridor. Unfortunately, the inclusion of malignant tracheal neoplasms in the differential diagnosis of onset of wheeze in adults is even more rare than the tumours themselves. We report a case where a tracheal adenoid cystic carcinoma presented symptoms suggestive of bronchial asthma. It is emphasized that delay by the physician in diagnosing tracheal tumours is the principal problem, and that adult patients who experience onset of stridor and dyspnoe and do not respond to accepted medical treatment deserve systematic radiographic and endoscopic evaluation of the entire air passage.

Aged↗

PubMed1991

Episodic nocturnal hypoxia and nasal packs.

Nasal obstruction influences respiration during sleep and nasal packs may cause obstructive sleep apnoea. In order to investigate this, the perioperative oxygen saturation was monitored for 3 nights with continuous pulse oximetry in 12 patients, who had bilateral nasal packs after septoplasty. A significant increase in the number of nocturnal episodes of hypoxia and a significant prolongation of the mean duration of the individual hypoxic periods were demonstrated during the first and the second post-operative nights. The clinical significance of these results is as yet unknown, but the use of partial nasal packing in septoplasty is advocated. Further investigations of nocturnal oxygen desaturation and design of nasal packs, securing the post-operative nasal airway, are needed.

Adolescent↗

PubMed1990

Peak flow nasal patency indices in patients operated for nasal obstruction.

In 26 patients undergoing operation for nasal obstruction, nasal and oral peak expiratory and inspiratory flow rates were measured preoperatively and 1 month postoperatively. Peak expiratory and inspiratory flow nasal patency indices were calculated from the ratio between the nasal and oral peak flow rates. Postoperatively, these indices were significantly increased for the total nose and for the preoperatively worse nasal cavity. No significant change was observed for the oral peak flow rates. A significant preoperative difference in nasal patency between the two nasal cavities was eliminated by surgery, as the postoperative peak flow of each nasal cavity reached 80% of the peak flow of the total nose on expiration and close to 50% on inspiration. A good correspondence between the subjective improvement of nasal patency and the increase in peak expiratory and inspiratory flow nasal patency indices was observed for the total nose. These findings show that peak flow nasal patency indices give valuable information pre- and post-operatively in patients undergoing nasal surgery and that the method is simple and easy to perform.

Adolescent↗

PubMed1990

Peak flow nasal patency indices and self-assessment in septoplasty.

The present study evaluates the results of septoplasty monitored by the objective peak flow nasal patency indices and the subjective patient self-assessment scores of nasal obstruction. Mini-Wright peak flow meters were used. The peak flow nasal patency index was defined as the ratio between nasal and oral peak flow rates. Uni and bi-lateral, as well as ex and in-spiratory, indices were calculated. Both peak ex and in-spiratory flow nasal patency indices were significantly increased 1 and 6 months post-operatively, indicating improved nasal patency. The most marked post-operative increase of the nasal patency indices was seen for the preoperatively worst airway and the total airway. A weak significant positive correlation was found between the peak flow nasal patency indices and the patient mean self-assessment scores of the uni and bi-lateral nasal obstruction. The change of the peak flow nasal patency indices measured 6 months post-operatively correlated well with the patient overall assessment of the operative changes of the total nasal patency. The method was found quick and easy to handle in monitoring the effect of functional septoplasty and is recommended as an alternative to rhinomanometry.

Adult↗

PubMed1989

Nasopharyngeal Warthin's tumour: a metaplastic lesion.

Warthin's tumour arising from minor salivary glands of the nasopharynx is described in a patient with eosinophilic rhinitis and nasal polyposis. The microscopical features of this lesion were indistinguishable from those of Warthin's tumours of the parotid gland. The present case supports the histogenetic theory that the epithelial component of extraparotid Warthin's tumours represents reactive oncocytic metaplasia and hyperplasia induced by chronic inflammation rather than genuine neoplasia. It is suggested that the term Warthin's tumour is preferable to designations indicating neoplasia of these extraparotid lesions which are indistinguishable histologically and ultrastructurally from parotid and juxtaparotid adenolymphomas.

Adenolymphoma↗

PubMed1989

Traumatic tympanic membrane perforations: complications and management.

There is great diversity in the methods of treating traumatic perforations of the tympanic membrane. To elucidate the controversy, we present a long-term follow-up study of 37 patients. On the basis of our present study and available relevant data in the literature, we emphasize that early surgical intervention of a traumatic myringeal perforation is not indicated, as most of these perforations (an average of 88%) do heal spontaneously without complications. However, we stress the importance of performing a meticulous auditory and vestibular examination with close follow-up and repeat audiograms in all patients with acute traumatic myringoruptures to provide enough information for diagnosis of a major perilymph leak that would warrant operation. Myringeal perforations or major conductive hearing losses persisting 3 months after injury warrant tympanotomy and appropriate reconstruction.

Adolescent↗