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A Blum

Publications and source records attributed to A Blum.

At least 55 records · Page 3Linked to original sources
PubMed2003

[Correlation between dermoscopy and histopathology in pigmented and non-pigmented skin tumours].

Dermoscopy (dermatoscopy, epiluminescence microscopy, surface microscopy) is a non-invasive method in dermatology. With this method pigmented and non-pigmented skin tumours can be diagnosed with a clear higher sensitivity and specificity compared to clinical examination. Malignant skin tumours are detected earlier and unnecessary excisions of benign skin tumours can be avoided. The knowledge about the correlation between dermoscopy and histopathology is hereby an essential condition. In this continuing medical education article the correlation of both examination techniques is presented for the dermoscopic differential diagnoses.

Basal Cell Carcinoma↗
PubMed2003

Anti-cytomegalovirus (CMV) IgG antibody titer in patients with risk factors to atherosclerosis.

Studies have demonstrated cytomegalovirus (CMV) DNA particles in restenotic lesions in atherosclerotic coronary arteries. We have shown that high (>1:800) anti-CMV IgG antibody titers in the serum are associated with active coronary disease and with post coronary angioplasty restenosis. In this study we assessed the anti-CMV antibody titer in patients with risk factors for atherosclerosis (but without documented clinical manifestations). One hundred and eighly-seven patients (men and women aged 40-80 years) that were admitted to the Department of Internal Medicine were recruited to this prospective study. All had at least one risk factor for atherosclerosis, and none had documented coronary artery disease. Fasting blood samples were drawn on admission. Risk factors included hypertension, diabetes mellitus, active smoking, hyperlipidemia, and a positive family history. Ninety-three age- and sex-matched individuals without atherosclerosis risk factors served as the control group. One Hundred and twentysix patients had high anti-CMV antibody titers (>/=1:800) compared with none in the control group. Although 80 patients (90%) in the control group were seropositive, none had anti-CMV IgG antibody titers higher than 1:400. The statistical difference between the patients and the control group was highly significant ( p<0.0001). An immunological response against CMV (expressed as an anti-CMV IgG antibody titer) could be a marker of a long-standing immunological reaction causing an inflammatory response that eventually would cause advanced clinical atherosclerosis. We suggest that anti-CMV antibody titer should be used as an early predictor of atherosclerosis. Our findings support the infectious theory and an association between CMV infection and atherosclerosis at an early stage, maybe even years before clinical events occur.

Adult↗
PubMed2003

The dermoscopic classification of atypical melanocytic naevi (Clark naevi) is useful to discriminate benign from malignant melanocytic lesions.

BACKGROUND: The dermoscopic classification is a useful tool for handling patients with atypical naevi (Clark naevi). OBJECTIVES: To investigate if the dermoscopic classification of atypical naevi is of any value to discriminate benign from malignant melanocytic lesions. METHODS: Consecutive patients (n = 205) were included with 254 suspicious melanocytic lesions, confirmed by histopathology at the Pigmented Lesions Clinic of the Department of Dermatology, University Medical Center, University of Tuebingen, Germany. In this retrospective study, dermoscopic images of benign and malignant melanocytic lesions were classified according to the dermoscopic classification of atypical naevi (reticular, globular, homogeneous or combinations of two of these) and pigmentation (uniform, central hyper- or hypopigmentation, eccentric peripheral hyper- or hypopigmentation, or multifocal hyper- or hypopigmentation). The three-structure type (reticular, globular and homogeneous) was additionally defined. RESULTS: Reticular, homogeneous and reticular-homogeneous types were significantly more frequent in naevi than in melanomas, whereas the three-structure type was significantly more frequent in melanomas (P < 0.001). A sensitivity of 86.7%, specificity of 87.7% and diagnostic accuracy of 87.4% was obtained. Uniformly pigmented and centrally hyperpigmented types were significantly more frequent in naevi than in melanomas, whereas eccentric peripheral hyperpigmented and multifocal hyper- or hypopigmented types were significantly more frequent in melanomas (P < 0.001). CONCLUSIONS: The dermoscopic classification of atypical naevi (Clark naevi) is useful to discriminate benign from malignant melanocytic lesions. The three-structure type and eccentric peripheral hyperpigmentation were significantly more frequently found in malignant than in benign melanocytic lesions. The knowledge of these two dermoscopic types should be helpful for the management of patients presenting with multiple melanocytic lesions.

Adolescent↗
PubMed2003

[Follow up of total hip prothesis: storage phosphor versus screen-film radiography].

PURPOSE: Digital radiography may lead to interpretation difficulties in patients with hip prosthesis, especially when initial evaluation was performed using screen film radiography. The purpose of this study was to evaluate inter-observer and inter-technique reproducibility comparing digital and screen-film radiography. MATERIAL AND METHODS: Twenty-eight patients with unilateral (n=24) or bilateral (n=4) hip prosthesis (total=32 prostheses) underwent screen-film and digital (storage phosphor) radiography. The bone-cement and metal-cement interfaces were evaluated for the presence of a lucent line in 14 different sectors reclassified into 3 regions. This evaluation was performed by two independent readers. Inter-observer and inter-technique reproducibility were calculated using kappa values. RESULTS: The inter-observer reproducibility was negligible, poor or average with Kappa values ranging from 0.07 to 0.47. The degree of agreement between the two methods was poor, average or good for both observers with Kappa values ranging from 0.10 to 0.66. CONCLUSION: Although inter-technique agreement is not high, it is better than inter-observer agreement. Therefore, storage phosphor technique should not be rejected for total hip prosthesis follow-up, even though previous films were screen-film radiographs.

Adult↗
PubMed2003

[MR-arthrography: general principles and applications].

The recent approval by the French Ministry of Health of the use of intra-articular Gadolinium could promote the increasing use of MR-arthrography in France. Although useful in specific pathologies, it should not be overly prescribed and should be considered only if it provides a more accurate diagnosis than other less invasive techniques. The technical aspects and medico-legal implications of MR-arthrography as well as its various indications are reviewed in this article. There are three possible techniques: indirect MR-arthrography with IV Gadolinium injection, direct MR-arthrography with intra-articular Gadolinium injection and lastly, direct MR-arthrography with intra-articular injection of iodinated contrast media (or saline solution). Indirect MR-arthrography cannot be recommended because of insufficient contrast enhancement and the absence of joint filling. Conversely, direct MR-arthrography allows joint expansion which smooths out capsule and ligaments, better delineates articular surfaces and yields a homogeneous high intensity signal of the entire joint. Direct MR-arthrography with iodinated contrast media combines standard arthrography with conventional MRI. Direct MR-arthrography with intra-articular injection of dilute Gadolinium is associated with T1WI, usually of higher quality than T2WI, even though the latter remains part of the protocol. Although, the last two techniques yield higher image quality and are often performed for various articular pathologies, they should not be randomly carried out in the evaluation of joint pathology. However, they should be recommended as the first step in the diagnosis of painful shoulders or hips in young adults and athletes.

Arthrography↗
PubMed2002

[Preoperative evaluation of renal carcinoma using multi-detector CT].

When laparoscopic nephrectomy is performed, the limited visibility of many anatomical structures requires additional pre-operative information. However, most of this information can be highlighted by Multislice-CT which depicts all the vascular structures while providing an essential road mapping for the surgeon. Besides underlining arterial abnormalities, this technique allows to depict venous pathways and tumoral invasion. This review illustrates the various potential applications of Multislice-CT in the evaluation of renal tumors.

Humans↗
PubMed2002

[Lipomatous tumors of soft tissues in the extremities and the waist in adults].

Lipomatous tumors of the upper and lower extremities in adults are frequent and lipoma is the most common soft tissue tumor. Most have a typical appearance at imaging but presentation and management may vary based on the exact histological subtype. The purpose of this paper is to review the main clinical, radiological and histological features of the different benign and malignant lipomatous tumors.

Abdomen↗
PubMed2002

[Imaging of the lumbar spine].

The role of conventional radiographs in the evaluation of the lumbar spine remains unchanged. The respective place of CT and MRI in the evaluation of lumbar spine disorders has not significantly changed in spite of technical advances. However, their diagnostic capabilities have improved.

Adult↗
PubMed2001

[Manifestations of the "pretherapeutic phase" of malignant melanoma of the skin in Switzerland 1996-1998].

62 patients with a histologically confirmed diagnosis of cutaneous malignant melanoma were interviewed from 1996 to 1998. Lesions were found mostly on patients backs (30.6%) and they were noted most frequently because of a change in colour (darker) (50%) and increase in size (43.5%). The median time between first noticing the melanoma and visiting a physician was one month, but for 28% of the patients it was more than three months. The median time between a medical examination and surgical removal was shorter than one month, but for 22% of the patients it was more than three months. Patients with bleeding lesions sought medical help later (14 months). Misdiagnosis led to a six months delay in treatment and if no action was taken there was a 13 months delay.

Adult↗
PubMed2001

A model on the regulation of 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase expression in Comamonas testosteroni.

3alpha-Hydroxysteroid dehydrogenase/carbonyl reductase (3alpha-HSD/CR) from Comamonas testosteroni is a key enzyme involved in the degradation of steroids and xenobiotic carbonyl compounds. The enzyme has recently been cloned and characterized by our group. A strong induction of enzyme activity is observed in the presence of steroids like testosterone. In the present investigation, two repressor proteins (Rep1 and Rep2) containing 78 and 420 amino acids, respectively, were found to regulate 3alpha-HSD/CR gene (hsdA) expression. Gel shift experiments showed that Rep2 binds to a 10 nucleotide sequence 9 bp upstream of the hsdA promoter. The deletion of this cis-regulating sequence significantly increases hsdA expression. About 1633 bp further upstream, a second ten nucleotide sequence, complementary to the first one, was found, which is also recognized by Rep2 and increases hsdA expression, if deleted. To purify the repressor proteins, the genes encoding each were cloned into His-tag expression vectors and overexpressed in Escherichia coli. Rep1 does not bind to DNA but may bind to 3alpha-HSD/CR mRNA as predicted by its secondary structure. Concluding from our data, induction of 3alpha-HSD/CR in C. testosteroni by steroids in fact appears to be a de-repression, where the steroidal 'inducer' prevents the binding of the two repressor proteins to the hsdA promoter and mRNA, respectively.

3-Hydroxysteroid Dehydrogenases↗
PubMed2001

Human 11beta-hydroxysteroid dehydrogenase 1/carbonyl reductase: additional domains for membrane attachment?

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD 1) is a membrane integrated glycoprotein, which physiologically performs the interconversion of active and inactive glucocorticoid hormones and which also participates in xenobiotic carbonyl compound detoxification. Since 11beta-HSD 1 is fixed to the endoplasmic reticulum (ER) with a N-terminal membrane spanning domain, the enzyme is very difficult to purify in an active state. Upon expression experiments in Escherichia coli, 11beta-HSD 1 turns out to be hardly soluble without detergents. This study describes attempts to increase the solubility of 11beta-HSD 1 via mutagenesis experiments by generating several truncated forms expressed in E. coli and the yeast Pichia pastoris. Furthermore, we investigated if the codon for methionine 31 in human 11beta-HSD 1 could serve as an alternative start codon, thereby leading to a soluble form of the enzyme, which lacks the membrane spanning segment. Our results show that deletion of the hydrophobic membrane spanning domain did not alter the solubility of the enzyme. In contrast, the enzyme remained bound to the ER membrane even without the N-terminal membrane anchor. However, activity could not be found, neither with the truncated protein expressed in E. coli nor with that expressed in P. pastoris. Hydrophobicity plots proved the hydrophobic nature of 11beta-HSD 1 and indicated the existence of additional membrane attachment sites within its primary structure.

11-beta-Hydroxysteroid Dehydrogenase Type 2↗
PubMed2001

Dermatoscopy turns histopathologist's attention to the suspicious area in melanocytic lesions.

BACKGROUND: Histopathologically, the diagnosis of nevus-associated melanoma or melanoma close to a common nevus can be missed if the specimen is cut in a nonrepresentative area or if the section shows only the associated common nevus. OBJECTIVE: To find out whether dermatoscopy of suspicious areas within a nevus can improve the histological diagnosis of malignant melanocytic lesions of the skin. MATERIALS: The study was based on dermatoscopic images of more than 2000 benign and 115 malignant pigmented lesions and a collection of corresponding histopathologic slides. METHODS: The dermatoscopic images and the corresponding histopathologic diagnoses were compared. In case of differences, the histopathologic findings were reevaluated and compared with the dermatoscopic findings. RESULTS: Three cases were identified in which melanoma could have been histopathologically missed as a result of improper sectioning. After the dermatoscopic findings were evaluated, the specimens were reembedded and further sections were obtained. Finally, nevus-associated melanoma or melanoma close to a common nevus was diagnosed. CONCLUSIONS: Specific dermatoscopic patterns of malignancy can be found in highly suspicious areas, eg, broadened networks, radial streaming, pseudopods, or dots located at the periphery. The dermatoscopic-histopathologic correlation can improve the diagnosis of melanoma. Therefore, the clinician should point to the most suspicious area with a drawing or image, and the suspected diagnosis of melanoma and the history of the lesion should be also mentioned.

Abdomen↗
PubMed2001

Dermoscopic classification of atypical melanocytic nevi (Clark nevi).

OBJECTIVES: To create a dermoscopic classification of atypical melanocytic nevi (Clark nevi) and to investigate whether individuals bear a predominant type. DESIGN: Digital dermoscopic images of Clark nevi were classified according to structural features, ie, reticular, globular, or homogeneous patterns or combinations of these types. The nevi were also characterized as central hypopigmented or hyperpigmented, eccentric peripheral hypopigmented or hyperpigmented, or multifocal hypopigmented or hyperpigmented. SETTING: Two pigmented skin lesion clinics. PATIENTS: We examined 829 Clark nevi on 23 individuals. MAIN OUTCOME MEASURE: A reliable dermoscopic classification of Clark nevi and frequency of different dermoscopic types. RESULTS: Using the dermoscopic classification, the 829 Clark nevi were classified as follows: 221 (26.7%) as reticular, 167 (20.1%) as reticular-homogeneous, 148 (17.9%) as globular-homogeneous, 112 (13.5%) as reticular-globular, 89 (10.7%) as homogeneous, 84 (10.1%) as globular, and 8 (1.0%) as unclassified. Most individuals were prone to a predominant type of Clark nevus. Seven individuals (30%) showed a single type of Clark nevus in more than 50% of their nevi and 5 (22%) in more than 40% of their nevi. CONCLUSIONS: The proposed dermoscopic classification of Clark nevi is easily applicable and allows a detailed characterization of the different dermoscopic types of Clark nevi. Knowledge of these dermoscopic types should reduce unnecessary surgery for benign melanocytic lesions. Exact classification of the different types of Clark nevi is a necessary prerequisite for further clinical, dermoscopic, and histopathologic studies, which will give new insights in the biology of acquired melanocytic nevi.

Adolescent↗
PubMed2001

Structural evaluation of articular cartilage: potential contribution of magnetic resonance techniques used in clinical practice.

OBJECTIVE: To determine whether routine magnetic resonance imaging (MRI) techniques can detect age-related structural modifications of bovine articular cartilage. METHODS: The cartilage of 3-month-old, 3-year-old, and 13-year-old animals was studied. T1- and T2-weighted MR sequences were performed using a 1.5T clinical imager and a 3-inch surface coil. Histologic slices (5 microm) of cartilage specimens were stained with picrosirius red (for collagen) and toluidine blue (for glycosaminoglycans [GAGs]). A polarized light study was performed to determine the collagen network organization. Except for the 13-year-old animal cartilage, the biochemical content was studied on slices cut parallel to the surface to determine GAG and hydroxyproline (collagen) content. Cartilage profiles were performed to determine the MR pixel intensity and the histologic color intensity. RESULTS: On T1-weighted images, the cartilage was homogeneous, with pixel intensity profiles presenting low variations. On T2-weighted images, the cartilage was laminar in the 3-month-old animals and became homogeneous thereafter. The pixel intensity varied through the cartilage depth with a profile that depended on the age of the animal. The collagen and GAG staining showed abrupt transitions in the 3-month-old animal, while in older animals the cartilage became more homogeneous with a mild gradient of matrix constituents with depth. These results were confirmed by findings of a biochemical study. In addition to these matrix content variations, the bovine cartilage presented modifications of its collagen network organization with aging. CONCLUSION: The MR T2-weighted sequences depicted signal variations with age in bovine cartilage concomitant with modifications in its structure. If confirmed in clinics, these observations will reinforce the place of MRI in characterizing cartilage with aging and pathologic processes.

Aging↗
PubMed2001

Homocysteine levels in patients with risk factors for atherosclerosis.

BACKGROUND: Abundant epidemiological evidence has demonstrated that the presence of mild to moderate hyperhomocysteinemia is an independent risk factor for atherosclerosis in the coronary, cerebral, and peripheral vasculature, and for vascular disease, including coronary disease. It has been demonstrated that plasma total homocysteine level is a strong predictor of mortality in patients with angiographically confirmed coronary artery disease. HYPOTHESIS: The study was undertaken to determine the extent of homocysteine levels in patients without documented coronary artery disease, but with at least one risk factor for atherosclerosis. METHODS: Fasting blood samples were collected prospectively from 160 consecutive patients (50 women and 110 men, mean age 65+/-7 years) who had at least one risk factor for atherosclerosis, but had no documented coronary artery disease. Homocysteine levels were measured by an immunoassay method. RESULTS: Of the patients studied, 78 (48.75%) with at least one risk factor for atherosclerosis had high homocysteine levels; 62 patients had mild hyperhomocysteinemia (15-30 micromol/l); and 16 patients had moderate hyperhomocysteinemia (30-100 micromol/l). CONCLUSIONS: Our data suggest that hyperhomocysteinemia is highly prevalent in patients with risk factors for atherosclerosis. Homocysteine level (an independent convertible risk factor to atherosclerosis) should be measured routinely in patients with risk factors for atherosclerosis and treated appropriately.

Aged↗