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Biomedical subjects

R Burmeister

Publications and source records attributed to R Burmeister.

At least 19 recordsLinked to original sources
PubMed2001

Efficient eukaryotic expression system for authentic human sex hormone-binding globulin.

Sex hormone-binding globulin (SHBG) is the main carrier for androgens and oestrogens in humans. It mediates the transport of steroid hormones in the circulation and testicular fluid, and regulates their bioavailability to steroid-responsive tissues. In addition, the protein interacts with membrane receptors expressed in target tissues. Binding to the receptors is suspected to facilitate the uptake of steroid hormones and/or elicit cellular signal transduction. The identity of the SHBG receptor has not yet been resolved, in part due to a lack of sufficient quantities of authentic SHBG for receptor purification and molecular characterization. We have successfully addressed this problem by establishing an episomal expression system in human embryonic kidney cells that produces 5 mg of fully active human SHBG per litre. The recombinant protein resembles native SHBG in terms of structure, glycosylation pattern and steroid-binding activity. Moreover, the protein interacts with plasma membranes in steroid target tissues, an activity not observed with SHBG from other recombinant expression systems. Thus our studies have removed an important obstacle to the further elucidation of the role SHBG plays in steroid hormone action.

Cell Line↗
PubMed2001

A two-receptor pathway for catabolism of Clara cell secretory protein in the kidney.

Clara cell secretory protein (CCSP) is a transport protein for lipophilic substances in bronchio-alveolar fluid, plasma, and uterine secretion. It acts as a carrier for steroid hormones and polychlorinated biphenyl metabolites. Previously, the existence of receptors for uptake of CCSP.ligand complexes into the renal proximal tubules had been suggested. Using surface plasmon resonance analysis, we demonstrate that CCSP binds to cubilin, a peripheral membrane protein on the surface of proximal tubular cells. Binding to cubilin results in uptake and lysosomal degradation of CCSP in cultured cells. Surprisingly, internalization of CCSP is blocked not only by cubilin antagonists but also by antibodies directed against megalin, an endocytic receptor that does not bind CCSP but associates with cubilin. Consistent with a role of both receptors in renal uptake of CCSP in vivo, patients deficient for cubilin or mice lacking megalin exhibit a defect in tubular uptake of the protein and excrete CCSP into the urine. These findings identify a cellular pathway consisting of a CCSP-binding protein (cubilin) and an endocytic coreceptor (megalin) responsible for tissue-specific uptake of CCSP and associated ligands.

Animals↗
PubMed1995

[Tyrosine-protein kinase activity in breast neoplasm. Comparison with activity obtained in benign diseases and in normal tissues].

Tyrosine protein kinase (TPK) activity is associated to malignant cellular transformation. This work compares TPK activity in 27 surgical biopsy samples of mammary carcinoma, 10 samples of fibroadenomas, 13 samples of fibrocystic breast disease and 27 samples of normal mammary tissue. TPK activity was determined in tissue homogenates using (Val5) angiotensin II as exogenous substrate. In samples of mammary carcinoma, TPK activity was 33.86 +/- 31.98 pmol P32/mg protein/30 min. This value was significantly higher that those observed in fibrocystic disease (3.92 +/- 2.35), fibroadenomas (13.86 +/- 10.9) and normal tissue (3.56 +/- 3.02).

Adult↗
PubMed1995

[Radiologic visibility of breast fibroadenomas].

From a clinical point of view, all mammary fibroadenomas are similar. However some of them are not visible in mammograms, phenomenon probably related to glandular density. Aiming to elucidate whether the lack of visibility is caused by the glandular density or by tumor itself, a three stage study was performed. In 201 cases the mammographic visibility of fibroadenomas was determined and correlated with patient's age, the presence of fibrocystic disease and tumor histological type; after surgical excision, 18 fibroadenomas were sliced into 5 mm thick samples and X rayed to determine their visibility; finally 2 visible and 2 non visible tumors were calcinated at 550 degrees C and their ashes subjected to X-ray diffraction analysis. Twenty two percent of fibroadenomas were not visible on mammography, this percentage was higher for intracanalicular tumors, in younger women and in the presence of fibrocystic disease. Sixteen percent of excised and sliced tumors were not visible on X rays. Also, differences were found in X-ray diffraction studies between visible and invisible tumors, probably related to NaCl and KCl tumor content.

Adolescent↗
PubMed1992

Nutritional status of surgical patients and the relationship of nutrition to postoperative outcome.

A preoperative nutritional assessment including anthropometry, biochemical indices and global subjective assessment was performed for 127 patients admitted for elective gastrointestinal surgery. Of these, 24 were subjected to minor surgery, 65 to intermediate surgery and 38 to major procedures. Patients were followed postoperatively, recording complications or mortality. Intermediate and major surgery patients had lower triceps skinfold thickness and mid-arm circumference and greater weight loss than did minor surgery patients. Thirty-six percent of the patients suffered complications. No association was found between preoperative nutritional status and incidence of postoperative complications. Six patients died and they showed greater preoperative weight loss (21 +/- 6.5 vs 12 +/- 1.4%) and lower serum albumin levels (25 +/- 4 vs 35 +/- 1 g/l) than patients who survived complications. Global subjective assessment classified 43% of survivors as malnourished, compared to 100% of patients who died.

Anthropometry↗
PubMed1990

Use of thermography in the differential diagnosis of phylloides tumour.

Thermography can be used as a method of diagnosing breast masses. We report our results of its use in the differential diagnosis of fibroadenoma from phylloides tumours (n = 47 and 20 respectively). Thermographic resolution (Th) and the difference in temperature between the tumour and a similar zone in the contralateral breast (delta 2) were compared. Thermograms were class Th1 (with a similar thermal pattern in both breasts without hypervascularization or hot points) and Th2 (with hypervascularization or a hot area with a thermal difference with the same area in the opposite breast (delta 2) of less than 2 degrees C) in most (95.7 per cent) of the patients with fibroadenoma and were class Th5 (having one or more pathological sign) in 85 per cent of the patients with phylloides tumours. Patients with phylloides tumours had a mean delta 2 of 2.99 degrees C whereas most of the patients with a fibroadenoma showed no difference in temperature. Their mean delta 2 was 0.2 degrees C (P less than 0.0005). We conclude that thermography helps in differential diagnosis between a fibroadenoma and a phylloides tumour.

Adenofibroma↗
PubMed1990

[Prevalence of acute manifestations of pathologic gastroesophageal reflux].

We characterized the acute manifestations of gastroesophageal reflux in 46 patients attending an emergency ward. 43 were females and the mean age was 41 +/- 14. The diagnosis of G-E reflux was confirmed in all by the acid reflux test; esophagitis was present in 55% of patients submitted to endoscopy; the Bernstein test was positive in 43%. The population represents 3% of all emergency consults and 8% of gastroenterological consults. Severe epigastric pain, usually burning or constrictive and radiating to the dorsum, left hypochondrium and sternal region was the presenting form in 55% of patients. Pain was refractory to antispasmodic agents but was relieved by antacids. Dyspnea or bronchial obstruction was the main symptom in 16% of cases, heartburn in 13%, hematemesis in 6%. Among these patients a prolonged history of chronic G-E reflux was common. Surgical correction was undertaken in 6%, with some symptoms persisting in 17%.

Adult↗
PubMed1989

[Cecal pseudotumoral endometriosis: a rare cause of massive lower digestive hemorrhage. A clinical case].

A 45 year old female, with massive intestinal bleeding was subjected to barium enema disclosing a large lobulated mass in the caecum. A right hemicolectomy was performed. Gross pathological examination showed an infiltrative lesion of the caecum with superficial mucosal ulcerations. Histologically the cecal wall was studded with endometrial implants penetrating to the submucosal layer. No invasion of the mucosa was demonstrated. Recovery was uneventful. After 1 year of follow up the patient remain asymptomatic.

Cecal Neoplasms↗
PubMed1982

Radiation therapy with or without primary limited surgery for operable breast cancer: a 20-year experience at the Marseilles Cancer Institute.

Since 1960 more than 3000 consecutive patients with operable infiltrating breast carcinoma were treated by radiation therapy with or without primary limited surgery, which usually consisted of local excision. For tumors smaller than or equal to 5 cm the ten-year crude survival rate is 77% for patients without palpable axillary nodes (T1-2N0) and 63% for patients having axillary adenopathy (T1-2N0). For operable tumors exceeding 5 cm of diameter (T3N0-1) the ten-year crude survival is 34%. Thirty-five percent of the patients alive free of disease at ten years required a secondary operation for presumed local or regional tumor persistence or recurrence, although no residual disease was found in 24% of the operative specimens. Local-regional recurrence had no adverse effect on ten-year survival. This conservative approach offers most women with operable breast cancer an excellent chance at breast preservation with the same chance for ten-year survival as with radical mastectomy.

Axilla↗