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Biomedical subjects

A Erichsen

Publications and source records attributed to A Erichsen.

At least 19 recordsLinked to original sources
PubMed2006

Pulmonary involvement by Niemann-Pick disease. A report of six cases.

AIMS: Although pulmonary involvement is a known cause of morbidity in Niemann-Pick disease, histological features in the lung are not well characterized. The purpose of this study is to document the histological features seen in pulmonary involvement by types B and C Niemann-Pick disease and to correlate them with clinical and imaging data. METHODS AND RESULTS: Surgical lung biopsies from six patients (four with type B and two with type C disease) were reviewed and all showed diffuse endogenous lipid pneumonia, with lesser involvement of the interstitium by fibrosis and foamy macrophage accumulation. In type B disease only, there was also fine cytoplasmic vacuolation within the cytoplasm of ciliated epithelial cells. Neither disease showed foamy changes within pneumocytes. One patient had a bronchial cast removed on whole lung lavage. Electron microscopy showed abnormal lamellar inclusions within lysosomes of affected cells in type B disease. In patients with type C disease, biopsies were undertaken as part of investigations into acute respiratory failure in the context of multiorgan systemic presentation. Three patients with type B disease had clinical disease limited to the lung, all adults (mean age of 40 years) with unexplained diffuse parenchymal lung disease and mainly ground-glass shadowing on high-resolution computed tomography. CONCLUSIONS: Niemann-Pick disease should be considered for any patient with unexplained diffuse endogenous lipid pneumonia, even when disease is limited to the lungs and presentation is during adulthood.

Adult↗
PubMed1999

CT and MR imaging of the paranasal sinuses in cystic fibrosis. Correlation with microbiological and histopathological results.

PURPOSE: To compare CT and MR findings of the paranasal sinuses in patients with cystic fibrosis (CF) with microbiology and histopathology. Further, to compare microbiology from the maxillary sinuses, nasopharynx and sputum. MATERIAL AND METHODS: CT and MR imaging of the paranasal sinuses were performed in 10 CF patients. Endoscopy and maxillary sinus aspirates were obtained (guided by the MR findings) and analyzed microbiologically and histologically. Samples from the nasopharynx and sputum were analyzed microbiologically. RESULTS: CT and MR were equal in displaying the extent of soft tissue masses, which at CT were homogeneous, while MR showed heterogeneous signals. MR images also demonstrated circumscribed areas with signal void at the STIR sequence with corresponding high to intermediate signal at the T1-weighted sequence. P. aeruginosa was frequently cultured from these areas which we named the "black hole sign". Maxillary sinus cultures revealed the same bacteria as nasopharynx and sputum cultures combined. CONCLUSION: MR images were superior to CT in differentiating soft tissue masses in the paranasal sinuses in CF patients. Bacteria with potential for specialized iron uptake mechanisms were present in areas with signal void at the STIR sequence. Our hypothesis is that the MR "black hole sign" can be explained by paramagnetic properties related to bacterial agents.

Adult↗
PubMed1996

[The value of preoperative thoracic CT. 19 patients with bronchial cancer surgically treated].

The incidence of bronchial carcinoma is increasing. The only curative treatment so far has been surgery. The correlation between preoperative CT thorax and peroperative/pathologic findings was evaluated in order to assess the value of preoperative CT thorax in patients with bronchial carcinoma. The thoracic CTs of 96 patients with bronchial carcinoma who were referred to our outpatient clinic from January 1992 to September 1994 were reviewed. Only 19 patients (20%) underwent surgery (seven pulmectomies, nine lobectomies, two wedge resections, one explorative thoracotomy). The remaining 77 patients received either irradiation, chemotherapy or other palliative treatment. The tumours were classified according to the TNM system (T = tumour, N = node, M = metastases) of UICC (Union Internationale Centre le Cancer). In 11 of the 19 patients who underwent surgery a correct TN classification was assessed at CT, while in four the T classification and in another four the N classification was changed after peroperative and pathologic assessment. CT showed a slight tendency to overestimate T classification. As for the N classification, overestimation and underestimation were equal. We conclude that CT thorax is valuable in the preoperative staging of bronchial carcinoma.

Adult↗
PubMed1991

[Testicular germ cell tumor--pathogenetic aspects].

The article reviews recent findings in the carcinogenesis of male germ cell tumours. Histologic, cytogenetic and cell molecular studies indicate that the embryonal germ cell-the gonocyte-is the precursor cell. A step-wise modification of the gonocyte with gradual loss of genetic material, and participation of different oncogenes like myc and ras, are probably of great significance, but the modes and extent are unknown. The histogenesis of the different subtypes of germ cell tumours is still obscure.

Carcinoma in Situ↗
PubMed1991

Rapid supplementary fixation in frozen sections: microwave versus conventional fixation. A double-blind comparative study.

The preservation of morphological details in frozen sections subjected to microwave-assisted fixation was compared with that in frozen sections subjected to snap fixation with either formalin/ethanol or ethanol alone. Especially nuclear details were better preserved after short microwave fixation. Ethanol alone gave the poorest results, with loss of nuclear details in the majority of the cases. In this study there was no significant difference between the morphological results obtained with a cheap domestic oven and that with a specialized microwave processor. Microwave-assisted fixation in frozen sections is a simple, rapid method. It is recommended for use in routine laboratories.

Artifacts↗
PubMed1990

[Testicular germ cell tumors--epidemiology and risk factors].

An increasing incidence of testicular germ cell tumours has been observed in many white populations in this century. Ethnic genetic implications and lifestyle seem to influence the development of testicular cancers, whereas the influence of intrauterine conditions is under debate. Epidemiologic studies cannot explain the increasing incidence among young men. The age variation of incidence and histologic type indicates at least two different aetiological mechanisms. Testicular cancers among young men are most probably due to gonadal dysgenesis, whereas in old men they reflect the general increased risk of cancer with old age. The increased risk of developing testicular germ cell tumours among cryptorchid young men supports the gonadal dysgenesy hypothesis.

Adolescent↗
PubMed1989

A transplantable rat Leydig cell tumour. Properties of the prostaglandin E receptor.

In the present paper we have examined the properties of the prostaglandin E (PGE) receptor in a transplantable rat Leydig cell tumour (H-540). It appears that PGE1 and PGE2 share a common receptor in membrane particles from this Leydig cell tumour. From saturation analysis and modified Hofstee plots, the specific binding sites for PGE1 can be divided into a high (25%) and low affinity state (75%) with apparent equilibrium constants of dissociation (Kd) of 2.4.10(-7) mol/l and 4.4.10(-6) mol/l, respectively. Association rate kinetics at different temperatures employing 5.10(-9) mol/l [3H]PGE1 showed that specific binding was time- and temperature-dependent. At 37 degrees C an apparent steady state was achieved after approximately 4 h incubation. The binding of [3H]PGE1 was very tight and no dissociation was observed at 20 degrees C during the first 20 h. The free PGE1 receptor appears to be very unstable. Binding was reduced rapidly by storage at 0 degrees C, by freezing and thawing of membrane particles, and by incubation of concentrated membrane particles. Specificity curves showed that PGA1 and PGA2 displaced [3H]PGE1 from receptor to a somewhat lesser degree than PGE2 and PGE1, whereas PGs of the B, D, I and F series had little or no effect. The fact that inhibition of [3H]PGE1 binding by cold PGE1 occurred in the same concentration range as PGE1 activation of adenylate cyclase, indicates that the specific binding of PGE observed here represents functional receptors coupled to the adenylate cyclase.

Adenylyl Cyclases↗
PubMed1988

A transplantable rat Leydig cell tumor--5. Cellular localization of beta-adrenergic and prostaglandin receptors and their effects on testosterone production.

The cellular localization of beta-adrenergic and prostaglandin (PG) receptors and their effects on adenylate cyclase activity (AC) and testosterone production in vitro were investigated in a transplantable rat Leydig cell tumor (H-540). Separation of the tumor cells in Percoll gradients revealed that the specific binding of [3H]PGE1 and [125I]Cyanopindolol was found in the same fraction as that of [125I]LH. This fraction--judged by light microscopy of smears--consisted of tumor Leydig cells. In addition, [125I]cyanopindolol was found specifically bound in the red blood cell fraction. In the Leydig tumor cells, approx 25% of the beta-adrenergic receptors was identified as beta 1-receptors, whereas approx 75% of the receptors were of the beta 2-subtype. The AC in Percoll purified Leydig tumor cells was stimulated by hCG (6-fold), PGE1 (2-fold), PGE2 (1.5-fold), PGI1 (2-fold) and isoproterenol (2-fold). The AC in the red blood cell fraction was stimulated by isoproterenol whereas the PGs and hCG had little or no effect. hCG, isoproterenol and PGE1 were able to stimulate testosterone production in vitro. At 44 h incubation, PGE1 was the most potent stimulator of testosterone production. In conclusion, tumor Leydig cells possess hCG, PGE1, PGI2 and beta-adrenergic receptors coupled to the AC. PGE1 and beta-adrenergic agonists stimulate testosterone production after prolonged incubation in vitro.

Alprostadil↗
PubMed1988

A transplantable rat Leydig cell tumour. 6. Effect of castration and hypophysectomy on tumour growth, morphology and plasma levels of pituitary hormones and testosterone.

Growth rate and morphology were studied in a transplantable rat Leydig cell tumour (H-540) grown in intact, castrated and hypophysectomized rats. The plasma levels of pituitary hormones and testosterone were measured in the same rats. The results can be summarized as follows: 1. The growth curves of tumours in intact and castrated rats were S-shaped and very similar during the observation period of three weeks. 2. In hypophysectomized rats, the onset and progression of tumour growth were delayed, compared with intact and castrated rats. 3. The thymidine labelling index as well as the size of the S and G2 phase compartments were decreased in tumours greater than 10 g compared with smaller tumours and tumours grown in hypophysectomized rats. 4. Testosterone concentrations in plasma correlate well with increasing tumour weight up to approximately 10-15 g in intact and castrated rats. 5. Plasma testosterone levels in tumour-bearing hypophysectomized rats were 7-fold higher than those of corresponding intact and castrated rats. 6. In castrated rats, suppression of LH production occurs by very small tumours (less than 2 g), whereas FSH levels show a gradual decrease with increasing tumour size. PRL production was independent of castration, tumour weight, and testosterone levels. 7. In spite of no major differences in cell morphology, the morphometric analysis revealed a reduction in tumour cell size and nuclear size in hypophysectomized rats compared with intact and castrated rats. It is concluded that pituitary hormones stimulate tumour growth, but surprisingly appear to reduce the secretion of testosterone from these tumours.

Animals↗
PubMed1988

Radiological appearance of the ampulla of Vater.

The localized dilatation below the confluence of the bile and pancreatic ducts is known as the ampulla of Vater. The purpose of the present study was to delineate the radiological features of the choledochopancreaticoduodenal junction, with special reference to ampullar formation in this region. This was done by specimen radiography and review of the films from 255 examinations with endoscopic retrograde cholangiopancreatography. Full evaluation was possible in 200 cases. Ampullar dilatation was observed in only 9 (5.1%) of the 175 patients with a common terminal opening. No ampullar dilatation was observed in the 25 patients with separate openings of the duct. The appearance in the presence of ampullar dilatation is described. The distal end of the common bile duct, below its confluence with Wirsung's duct, has been known as the ampulla of Vater for nearly 130 years. This is a most important diminutive region of the human body, but there is little in the literature concerning its radiological presentation. In this report a radiological study is presented on the choledochopancreaticoduodenal junction.

Adolescent↗
PubMed1987

Relative selectivity of different beta-adrenoceptor antagonists for human heart beta 1- and beta 2-receptor subtypes assayed by a radioligand binding technique.

The affinity constants of inhibition (Ki values) for both beta 1- and beta 2-receptor subtypes were determined for four different beta-adrenoceptor antagonists by a radioligand binding technique in a human myocardial membrane preparation. The radioligand was the high affinity antagonist [125I]-(-)-iodocyanopindolol (ICYP), and the drugs tested were atenolol, metoprolol, ICI 141,292 and ICI 118,551. Different concentrations of the drugs at test were allowed to compete with a constant concentration of ICYP for the specific binding sites (beta-receptors). Ki values for beta 1- and beta 2-receptors for each beta-adrenoceptor antagonist were developed from these data by computer calculations. Atenolol and metoprolol were found to differ slightly regarding potency (absolute Ki values) and to be practically equal regarding relative selectivity (approx. 40; i.e. ratio between high and low Ki values), while ICI 141,292 was found to have slightly higher relative selectivity (approx. 60) and much higher potency. All these drugs exhibited highest affinity for the beta 1-receptor population. In contrast, ICI 118,551 exhibited a very high relative selectivity (approx. 300) with highest affinity for the beta 2-receptor subtype. The method represents a good supplement to physiological and clinical examinations of selectivity of beta-blockers, and offers several advantages regarding simplicity, specificity and accuracy.

Adrenergic beta-Antagonists↗
PubMed1984

A transplantable rat Leydig cell tumor--1. LH and prolactin receptors and effects of the endocrine status of the host animal.

We have examined the binding capacity and properties (affinity, specificity) of LH and prolactin (Prl) receptors in a transplantable rat Leydig cell tumor (H-540) grown in intact, castrated and hypophysectomized rats. LH receptors in adult rat testis and Prl receptors in the rat ventral prostate were examined simultaneously for comparison. The results can be summarized as follows: The qualitative properties (affinity, specificity) of LH and Prl receptors in tumor Leydig cells appear to be identical to those of corresponding receptors in non-tumor tissues. The levels of LH receptors in tumor Leydig cells are only some 1% of that present in normal Leydig cells from adult rats. Tumor Leydig cells grown in hypophysectomized rats had even lower levels of LH receptors; ca. 1/3 of that found in tumors from intact rats. The levels of Prl receptors in the tumor Leydig cells are almost as high as in normal Leydig cells from adult rats. In tumors grown in hypophysectomized rats, the levels of Prl receptors were much lower (ca. 20%) than in tumors from intact or castrated rats. There were great variations in the number of LH and Prl receptors in individual tumors, and there was a positive correlation (r = 0.88; P less than 0.01) between LH and Prl receptors in individual tumors. No differentiation toward a "LH receptor tumor" or "Prl receptor tumor" was observed. Thus, receptors for LH and Prl in tumor cells are qualitatively normal, but the number is greatly (LH) or moderately (Prl) reduced. These receptors in the tumor Leydig cells are stimulated by pituitary hormones.

Animals↗
PubMed1984

A transplantable rat Leydig cell tumor--2. Adenylyl cyclase activation by prostaglandin E1, isoproterenol and glucagon.

The responsiveness of the membrane bound adenylyl cyclase (AC) system to various hormones and hormone analogues in a transplantable rat Leydig cell tumor (H-540) has been investigated and compared with that of interstitial tissue from normal adult rats. The results can be summarized as follows: The AC of the Leydig cell tumors was stimulated by isoproterenol, epinephrine, norepinephrine, dopamine, glucagon, PGE1, PGF2 alpha and LH/hCG. The AC of the Leydig cell tumors exhibited a much greater response to PGE1 than the AC in normal interstitial tissue (5-fold and 2-fold stimulation, respectively). The AC of the Leydig cell tumours also revealed a somewhat higher response to isoproterenol than the AC of interstitial tissue (2.5-fold and 2-fold, respectively). Adenylyl cyclase in both tissues were equally stimulated by glucagon (2-fold). The LH response in the Leydig cell tumors was only half of that found in normal Leydig cells. This study indicates, that in spite of the fact that tumor Leydig cells respond to LH and produce testosterone, the response pattern of the AC is different from that of normal Leydig cells.

Adenylyl Cyclases↗