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Biomedical subjects

M Hagedorn

Publications and source records attributed to M Hagedorn.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Histogenesis of nevus cell nevi. Implications of a case report].

A case of multiple lesions of junctional melanocytic hyperplasia arising in a skin graft after excision of a congenital melanocytic naevus is reported. This observation is shown to support the concept of the histogenesis of acquired melanocytic naevi proposed by Cramer [2], i.e. that acquired melanocytic naevi are derived from melanocyte precursors located in nerve sheaths, whereas it is inconsistent with notions of the origin of naevogenesis in the epidermal melanocyte.

Adult↗
PubMed1994

[Pachydermodactyly. Sequela of obsessive-compulsive neurosis].

Pachydermodactyly is an acquired, asymptomatic swelling of the lateral sides of the fingers and is seen mainly in young men. The formal pathogenesis is a benign fibromatosis. The casual pathogenesis was until now unclear, although we believe, that exogenic factors are the main reason. Consequently Pachydermodactyly has to be considered as a result of compulsion neurosis.

Adolescent↗
PubMed1994

Hermeneutic photography: an innovative esthetic technique for generating data in nursing research.

In this article, the use of hermeneutic photography as an esthetic technique to enhance data generation is discussed. When photographs are used as an entrée for interviewing participants, they often elicit participants' stories and illustrate themes of experience. A discussion of the uses of hermeneutic photography as a method and suggestions for the use of photographs within nursing research are presented.

Data Collection↗
PubMed1994

[Endoscopic venous surgery in postphlebitic syndrome].

Endoscopy of the subfascial space of the lower medial calf is able to demonstrate the morphological changes of perforators in patients with postthrombotic syndrome. Inspection of the subfascial space allows the differentiation of competent and incompetent perforators and a following complete dissection of only incompetent perforators. By means of this method more information about the texture of the fascia cruris can be achieved.

Endoscopes↗
PubMed1993

Tenascin and decorin in epiretinal membranes of proliferative vitreoretinopathy and proliferative diabetic retinopathy.

Extracellular matrix (ECM) synthesis plays an important part in the pathogenesis of the intravitreal membranes and is thus characteristic of both proliferative vitreoretinopathy (PVR) and the involutive stages of proliferative diabetic retinopathy (PDR). Using a polyclonal antiserum against human decorin and a monoclonal antibody against human tenascin, we detected these molecules in membranes from patients with raumatic PVR (n = 10), idiopathic PVR (n = 8), and proliferative diabetic retinopathy (n = 8). We conclude that both tenascin and decorin play a role in the development of epiretinal PVR and PDR membranes by controlling cell adhesion and regulating ECM formation.

Antibodies, Monoclonal↗
PubMed1992

Retinal growth and cell addition during embryogenesis in the teleost, Haplochromis burtoni.

Neurogenesis of the developing embryonic retina is described for the African cichlid fish, Haplochromis burtoni, from 4 days post fertilization until all cell phenotypes are generated (day 7). Cell addition and differentiation both begin at the same absolute location which later becomes the central retina. As observed in most other vertebrates, cones and ganglion cells differentiate first, followed by amacrine and bipolar cells. Rod photoreceptors, which are added late, differentiate last. Changes in retinal thickness, retinal stretching, cell size, and cell density were measured during development. From day 4 through 7, there is an increase in retinal thickness largely due to the expansion of the inner plexiform layer (IPL) and outer nuclear layer (ONL). The inner nuclear layer (INL) decreases in thickness and there is a transient decrease in the density of cells in the scleral portion of the INL. Cells increase in size in the ganglion cell layer (GCL) and the vitread INL, decrease in size in the sclerad INL, and remain the same in the ONL. Changes in the density of the cell layers were observed: the density of ONL cells increased, the density of GCL cells decreased, and INL cells increased then decreased. From day 4 to day 6, eye growth is entirely due to cell addition because no retinal stretching was observed in the ONL or the horizontal layer. During this same developmental period, the pattern and rate of neurogenesis were measured in the differentiated portion of the retina by means of 3H-thymidine labeling. A small number of cell divisions within the differentiated INL precede the onset of cell divisions in the ONL. The number of 3H-thymidine labeled cells within the INL increases at a low rate consistent with an asymmetric pattern of cell division characteristic of stem cells. In contrast, cell divisions in the ONL increase exponentially, consistent with a symmetric pattern of cell division characteristic of progenitor cells. Double-label experiments (3H-thymidine and a rod specific opsin antibody) show that some of the symmetrically dividing cells in the ONL express the rod specific opsin within 2 days, suggesting that these dividing cells are rod progenitors. Although we do not hae conclusive evidence, these developmental processes support the hypothesis that stem cells within the INL could be the source of rod precursors in the embryonic teleost retina.

Animals↗
PubMed1992

Development of the jamming avoidance response and its morphological correlates in the gymnotiform electric fish, Eigenmannia.

The electric fish, Eigenmannia, will smoothly shift the frequency of its electric organ discharge away from an interfering electric signal. This shift in frequency is called the jamming avoidance response (JAR). In this article, we analyze the behavioral development of the JAR and the anatomical development of structures critical for the performance of the JAR. The JAR first appears when juvenile Eigenmannia are approximately 1 month old, at a total length of 13-18 mm. We have found that the establishment of much of the sensory periphery and of central connections precedes the onset of the JAR. We describe three aspects of the behavioral development of the JAR: (a) the onset and development of the behavior is closely correlated with size, not age; (b) the magnitude (in Hz) of the JAR increases with size until the juveniles display values within the adult range (10-20 Hz) at a total length of 25-30 mm; and (3) the JAR does not require prior experience or exposure to electrical signals. Raised in total electrical isolation from the egg stage, animals tested at a total length of 25 mm performed a correct JAR when first exposed to the stimulus. We examine the development of anatomical areas important for the performance of the JAR: the peripheral electrosensory system (mechano- and electroreceptors and peripheral nerves); and central electrosensory pathways and nuclei [the electrosensory lateral line lobe (ELL), the lateral lemniscus, the torus semicircularis, and the pace-maker nucleus]. The first recognizable structures in the developing electrosensory system are the peripheral neurites of the anterior lateral line nerve. The afferent nerves are established by day 2, which is prior to the formation of receptors in the epidermis. Thus, the neurites wait for their targets. This sequence of events suggests that receptor formation may be induced by innervation of primordial cells within the epidermis. Mechanoreceptors are first formed between day 3 and 4, while electroreceptors are first formed on day 7. Electroreceptor multiplication is observed for the first time at an age of 25 days and correlates with the onset of the JAR. The somata of the anterior lateral line nerve ganglion project afferents out to peripheral electroreceptors and also send axons centrally into the ELL. The first electroreceptive axons invade the ELL by day 6, and presumably a rough somatotopic organization and segmentation within the ELL may arise as early as day 7. Axonal projections from the ELL to the torus develop after day 18.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

[Wound management with split skin flaps--donor sites. Covering with the moist gel Geliperm].

In 23 patients, donor sites of split-thickness skin grafts were treated with Geliperm Hydrogel, a swellable polyacrylamide agar. Healing duration, toleration, exudation and pain were all noted during the daily change of dressing. In 22 of the 23 cases, good healing was obtained after an average of 12.3 days. We feel that Geliperm is excellently suitable for covering the donor sites of split-thickness skin grafts.

Acrylamides↗
PubMed1990

Synodontid catfish: a new group of weakly electric fish. Behavior and anatomy.

Three species of synodontid catfish can produce weak biphasic electric discharges in either continuous or burst-like fashion. The peak-power frequency of these electric organ discharges is around 100 Hz. The electric organ appears to have originated from a sonic muscle: the organ lies dorsal to the swim bladder, contains modified muscle tissue, and is innervated from a motor nucleus located in the caudal medulla. It is possible that synodontid catfish use electric signals in communication and/or object detection.

Animals↗
PubMed1990

[Covering circular skin defects using 4 rhombic transposition flaps].

Based on Limberg's principles concerning the design of local flaps, S. B. Jugo developed a new technique for the closure of circular skin defects: The defect is divided into 4 quadrants; then 4 symmetrical rhombic flaps are raised from the surrounding skin, all pointing in the same direction of rotation. The sides of each flap correspond to the radius of the skin defect and form an angle of 68 degrees. Finally, the flaps are rotated into the defect and sutured to each other. This technique is especially useful with large lesions of the trunk.

Aged↗
PubMed1990

[Determination of epidermal growth factor (EGF) receptors in basal cell carcinomas, squamous cell carcinomas and melanomas].

We studied the binding of EGF receptors (EGF-R) in 19 basal cell carcinomas, 8 squamous cell carcinomas, and 9 malignant melanomas. Specific binding of EGF-R was detected in 10 of the basal cell carcinomas, and in all the 8 squamous cell carcinomas. None of the malignant melanomas showed EGF-R binding. A comparative study of the receptor status vs. clinical prognostic data, such as grading and clinical course, did not reveal any significant differences, whereas in ovarian carcinomas, the EGF receptor correlated with the prognosis.

Biomarkers, Tumor↗
PubMed1990

[Detection of epidermal growth factor-like factors in various skin tumors].

EGF-like factors (EGF-F) in tissue extracts make use of the EGF receptor system (EGF-R) in order to transmit biological signals. EGF-F, which partly show transforming activities, can be detected with the help of an EGF receptor assay. We measured the EGF concentrations in extracts of 25 benign, 5 semi-malignant, and 13 malignant skin tumors, as well as in 5 biopsies of normal skin. The highest amounts of EGF-F were found in malignant melanoma (10 ng/mg) and in squamous cell carcinoma (7 ng/mg). The EGF-F concentrations in benign and semi-malignant tumors, in contrast, were similar to those found in normal skin (up to 4 ng/mg). Isoelectric focusing (IEF) revealed that the activity of EGF-F malignant tumors consists of various components.

Biomarkers, Tumor↗
PubMed1989

[Genital vulvar lichen sclerosis in 2 siblings].

Lichen sclerosus of the vulva mainly occurs in older women, but shows another peak of incidence at the age just before puberty. The etiology of the disease, which is characterized by firm atrophy, is not known. There are some hints for a genetic disposition, such as a certain constellation of HLA and familial incidence. Our present case report is concerned with the clinical course of vulval lichen sclerosus in sisters, which had almost simultaneously developed. In both cases, the disease was successfully treated with a cream containing thyme extract; there were no side effects.

Atrophy↗
PubMed1989

[Stimulation of phagocyte activity by Thym-Uvocal in chronic skin infections].

15 patients with chronic relapsing bacterial skin infections (pyodermia, furunkulosis) and chronic recurring intestinal candidosis have been treated successfully with a thymus peptide mixture. The initially decreased indices of phagocytosis could be increased or normalized by this therapy. The results clearly demonstrate the efficiency of a thymus peptide mixture and encourage for further investigations. No side effects have been reported during the study.

Adjuvants, Immunologic↗
PubMed1989

Bowenoid papulosis. Classification as a low-grade in situ carcinoma of the epidermis on the basis of histomorphologic and DNA ploidy studies.

The nature of bowenoid papulosis was investigated by a comparative investigation of 12 biopsy specimens of this lesion, 19 biopsy specimens of Bowen's disease, 14 biopsy specimens of squamous cell carcinoma and 10 biopsy specimens of seborrheic keratosis. In addition to conventional histomorphologic and cytomorphologic studies, nuclear DNA measurements on single cells isolated from tissue blocks were performed using a TV image analysis system combined with an automatic microscope. Two parameters, the "5c exceeding rate" (5cER) and the "2c deviation index" (2cDI), were computed from the single-cell DNA values to arrive at a "DNA diagnosis" and a "DNA malignancy grade" (DNA-MG). All specimens of bowenoid papulosis and Bowen's disease were morphologically diagnosed as in situ carcinomas of the epidermis; a DNA diagnosis of malignant was rendered in all of these specimens due to the detection of aneuploid nuclei (5cER greater than or equal to 1). DNA diagnoses of malignant were also rendered on all specimens of squamous cell carcinoma (100% sensitivity) while DNA diagnoses of benign were rendered in all specimens of seborrheic keratosis (100% specificity). The mean DNA-MG for bowenoid papulosis (0.69) was significantly lower than that for Bowen's disease (1.04) and squamous cell carcinoma (1.15). The mean morphologic (Broder's) grade of malignancy was also lower for bowenoid papulosis than for Bowen's disease and squamous cell carcinoma. HPV 16 DNA was detected in 10 of 12 specimens of bowenoid papulosis. Thus, the results of DNA image cytometry and morphologic investigation suggest that bowenoid papulosis is a low-grade carcinoma in situ of the epidermis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Epidemiology of dysplastic nevus].

The dysplastic naevus is regarded as a precursor of malignant melanoma of the skin and has distinctive features that are apparent on clinical and particularly histological examination. Epidemiological studies on the incidence of dysplastic naevi in Europe have not yet been reported. A total number of 500 white males (median age: 19 years) have been examined. Macroscopically dysplastic naevi were detected in 2.2%. This result corresponds to reports from the United States of America and Australia.

Adolescent↗
PubMed1989

[Lichen ruber ulcerosus].

The case report of a 83-year-old woman with lichen ruber ulcerosus is reviewed. Clinically the patient showed extensive ulcerations of the sole of one foot, with synechiae of the toes. In addition, there was subtotal atrophic alopecia of the scalp, vulvar atrophy, and circumscribed cutaneous lesions of lichen planus. The disease started with chronic recurrent paronychiae. The ulcerative defect was successfully treated with mesh grafting, which is the therapy of choice.

Aged↗