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Biomedical subjects

S Pahl

Publications and source records attributed to S Pahl.

28 records · Page 2Linked to original sources

Expression analysis of genes at 3q26-q27 involved in frequent amplification in squamous cell lung carcinoma.

Gene amplifications are known to occur frequently in lung cancer. Recently, we identified gene amplifications at 3q26 in squamous cell lung carcinoma (SCC) using reverse chromosome painting. Here, our aim was to analyse the expression of genes which map within the amplified chromosomal region. The genes which were selected for their known function and their potential involvement in tumour development included the genes for ribosomal protein L22 (RPL22), butyrylcholinesterase (BCHE), glucose transporter 2 (SLC2A2), transferrin receptor (TFRC), thrombopoietin (THPO) and the phosphatidylinositol-3 kinase catalytic alpha polypeptide (PIK3CA). While five genes were expressed in the majority of the 17 samples of SCC, the gene for the glucose transporter 2 (SLC2A2) was expressed in only three cases, excluding SLC2A2 as the target gene of the amplification unit. For a subset of tumours, we determined the amplification status of the six genes. The TFRC, PIK3CA, BCHE, THPO and SLC2A2 genes were amplified in several cases, whereas the RPL22 gene was amplified in only one case. The combined amplification and expression data of this and our previous studies indicate that the amplified region at 3q26 contains several genes that are transcribed in SCC, providing the possibility that several amplified and functionally important genes at 3q26 may be involved in the pathogenesis of SCC.

Blotting, Southern↗

[Calcifying pseudotumor of the orbits].

Orbital pseudotumor can be divided histopathologically into three basic types: lymphoid, granulomatous and sclerosing. Chronic lymphoid and granulomatous types may eventually transform into the sclerosing type. The calcifying orbital pseudotumor is a very rare disorder due to a chronic, idiopathic inflammatory process of the orbit. The granulomatous type shows a good response to steroids while radiotherapy is the method of choice for lymphoid lesions. In general, calcifying pseudotumors can be treated only by operative exploration and tumor removal. We report a patient with a calcifying pseudotumor of the orbital apex that was removed through an endonasal approach. Preoperative diagnostic procedures and differential diagnosis are discussed.

Adult↗

[A familial anterior corneal degeneration: clinical aspects, histopathology and differential diagnosis].

BACKGROUND: We report on three cases of a progressive anterior corneal degeneration with clinical characteristics of limbal insufficiency occurring in three persons in three consecutive generations of one family. The disease has not yet been described in literature. PATIENTS: A woman aged 68, her 51 years old son and his 19 years old son are affected by the disease, which suggests autosomal dominant inheritance. None of the affected family members suffers from any form of collagenosis, endocrine insufficiency, chronic dermatosis, alteration of fat metabolism or other relevant systemic diseases. There is no accompanying disease of lids and conjunctiva except of a keratoconjunctivitis sicca with alteration of the mucin phase. The youngest affected member has a binocular anterior polar cataract. In the eldest affected member we performed penetrating keratoplasty. HISTOPATHOLOGY: Revealed thinning of corneal epithelium, moderate intra- and subepithelial granulocytary infiltration, a marked hyaline thickening of Bowman's membrane. The adjacent stroma showed accumulation of granulocytes and an increased number of capillaries and fibroblasts. Posterior stroma, Descemet's membrane and endothelium were normal. There were no goblet cells in the central epithelium. CONCLUSIONS: The appearance of the disease in three consecutive generations (strongly suggesting autosomal dominant inheritance) and the progressivity are characteristics of a dystrophical process. Development of a circular pannus and infiltration of epithelium and stroma with granulocytes however classify the disease as a degeneration, clinically and pathologically similar to Salzmann's nodular degeneration and to autosomal dominantly inherited keratitis.

Adult↗

Cystadenoma of the parotid gland with unusual prominent lymphoid stroma.

A rare variant of the cystadenoma of salivary gland origin is presented, which occurred in the parotid of a 36-year-old, otherwise healthy female patient. The tumour showed a dense follicle-containing lymphoid stroma, resembling papillary cystadenoma lymphomatosum (Warthin's tumour). In contrast to that, the epithelial lining gave a more irregular impression and oncocytic metaplasia were completely absent. Light microscopic and immunohistochemical features of the tumour are described and compared with those of classical cystadenoma and papillary cystadenoma lymphomatosum (Warthin's tumour). Other relevant multicystic epithelial parotid lesions, which are commonly associated with a prominent lymphoid component are discussed.

Actins↗

[MRI in testicular diagnosis: differentiation of seminoma, teratoma and inflammation using a statistical score].

PURPOSE: To differentiate scrotal pathology via MRI by means of a statistical score. METHODS: Between 1989 and 1995 MR images of 105 patients with scrotal pathology were rated retrospectively. In 69 cases linear discriminant analysis was used to differentiate seminoma, teratoma and inflammation. Six MRI attributes were found to be necessary and were weighted with a factor according to their importance. These factors were used to build a score. RESULTS: Criteria found to be important contained the distribution of the variate extensions of elements inside the pathological area and their maximal and minimal signal intensities. Furthermore, the contrast pattern of the pathological area and the visibility of healthy tissue in the pathological testicle was of importance. Seminoma was found to be homogeneous and well demarcated against healthy tissue. Teratoma was also well defined but characterised by inhomogeneous distribution of signal intensities. Inflammation showed diffuse signal increase of the pathological testicle, especially in T1-sequences. Using the score differentiation between tumors and inflammation succeeded in 94.2% between seminoma and teratoma in 89.7%. CONCLUSIONS: Compared to other studies using visual MR image analysis differentiation of scrotal diseases was improved by using a statistical score.

Adult↗

Prevalence of adrenal and extra-adrenal Conn syndrome in hypertensive patients.

BACKGROUND: Primary aldosteronism (PA) is caused by an adrenal aldosterone-producing tumor (A-APT) or adrenal hyperplasia. An extra-adrenal APT (E-APT) as a cause of PA has been reported in 5 cases. Autopsy studies show a high incidence of ectopic adrenocortical tissue. We did a prospective study of the prevalence of A-APTs and E-APTs and the biochemical features of E-APTs in patients with PA. METHODS: Hypertensive patients (N = 3900) referred to our unit were screened for PA by measuring renin activity, urinary aldosterone-18-glucuronide, tetrahydroaldosterone, and 18-hydroxycorticosterone (18-OH-B). Primary aldosteronism was found in 257 cases. The differentiation between A-APTs and adrenal hyperplasia was based on the results of postural response of renin, plasma aldosterone, 18-OH-B, computed tomography, isotope scanning, or adrenal venous aldosterone. Ultrasound examination of the abdomen was used to screen for E-APT. RESULTS: The cause of PA was bilateral adrenal hyperplasia in 101 cases, unilateral adrenal hyperplasia in 2, an A-APT in 146, and an E-APT in 1. The site of aldosterone production was uncertain in 7 patients who had normal adrenal glands on computed tomography but refused to undergo isotopic scanning and adrenal venous catheterization. Ultrasound examination disclosed normal retroperitoneum in 4 of the 7 cases but could not rule out E-APT in 3 cases. The biochemical features of the patient with the E-APT were similar to classic A-APT, with low renin, high aldosterone, and high 18-OH-B values without appropriate response to posture or to short-term volume expansion. The excision of the E-APT in the right kidney resulted in normalization of blood pressure and renin, aldosterone, and 18-OH-B levels. CONCLUSION: Although E-APT is rare, it should be considered in the interests of specific therapy for PA because aldosterone-secreting malignant ovarian tumors also have been reported.

Adrenal Cortex Neoplasms↗

A new subset of mineralocorticoid hypertension with excess of 21-deoxyaldosterone and Kelly's-M1 steroid: clinical and morphological findings.

Ten cases of adrenal adenomas, one case with unilateral adrenal hyperplasia, and another case with apparent bilateral are reported, in whom an alternative pathway of aldosterone via 21-deoxyaldosterone is operative. They all manifested hypertension, low renin activity, low normal potassium values, as well as high urinary excretion rates of 21-deoxyaldosterone and its related metabolite Kelly's-M1 steroid. In all cases, urinary aldosterone metabolites (aldosterone-18-glucuronide and tetrahydroaldosterone) and aldosterone precursor 18-hydroxycorticosterone levels were normal. Hence, the adrenal lesions give rise to hyper-21-deoxyaldosteronism. 21-Deoxyaldosterone is a weak mineralocorticoid, and its elevated production in the presence of normal aldosterone can induce a pathological state of hypermineralocorticoidism. Adrenalectomy resulted in normalization of hypertension in six of eight and amelioration in two of eight cases. Six of seven adenoma cases examined as well as the case of unilateral adrenal hyperplasia were sensitive to ACTH. One of the seven adenomas and, as expected, the case with apparent bilateral hyperplasia were angiotensin responsive. Histologically and electron microscopically, the operated adenomas consisted predominantly of clear cells, characterized by mitochondria with tubulo-vesicular internal structure similar to those of the zona fasciculata (in contrast, our classical Conn's adenoma with normal 21-deoxyaldosterone excretion exhibited a more heterogenous histological appearance and were, in terms of ultrastructure, more similar to cells of the zona glomerulosa). Ultrastructurally and immunocytochemically, the clear cells of 21-deoxyaldosterone adenomas showed features of both the zona glomerulosa and the zona fasciculata and are, hence, considered to be hybrid cells. We conclude that the determination of 21-deoxyaldosterone and Kelly's-M1 should be considered in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma has been detected with an imaging procedure.

Adenoma↗

[Clinical anatomy of the interosseous arteries of the forearm].

In recent years, several local flaps have been developed, based on the anterior and posterior interosseous arteries and their anastomoses at the wrist (e.g. posterior interosseous flap, pronator quadratus flap etc.). The anatomy of the arterial network supplying the flap is well established in both clinical and anatomical literature. Most authors agree in the constancy of the anastomoses between the interosseous arteries at the wrist and the absence of major anatomical variations excluding the use of the flap. In the present study, which is based on cadaver dissections of 60 preserved specimens, several gross vascular variations of the interosseous arteries have been found. The most frequent types were an additional anastomosis between the posterior interosseous artery and a perforating branch of the anterior interosseous artery in the middle third of the forearm, which was found in 20%. Ring-formations of the palmar and the dorsal branch of the anterior interosseous artery occurred in 5%. The point of perforation of the interosseous membrane by the dorsal branch of the anterior interosseous artery was found to vary in a larger extent, as described previously.

Aged↗

Genetic imbalances in preinvasive tissue of hypopharynx provide evidence for cytogenetic heterogeneity.

Multiple chromosomal aberrations have been reported in head and neck squamous cell carcinoma (HNSCC). But less information is available on specific patterns of chromosomal amplifications which distinguish different areas of head and neck tumors. To elucidate genetic mechanisms causing the aggressive growth and high proliferation of hypopharyngeal squamous cell carcinoma (SCC), we performed reverse chromosome painting (RCP) on a total of eight hypopharyngeal SCC including invasive carcinoma and preinvasive tissue. Five hypopharyngeal invasive carcinomas showed amplifications on chromosome 3q. Furthermore, we detected gains on chromosomes 11q and 6p. Compared to the histologically classified preinvasive tissues, we found amplified alterations on chromosome 6p, 11q and 12q, but none of them showed gains on chromosome 3q. This observed heterogeneity in hypopharyngeal SCC might reflect a specific role of chromosome 3q as a late event in the highly invasive capacity of these SCC.

Carcinoma, Squamous Cell↗