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Biomedical subjects

K Middendorf

Publications and source records attributed to K Middendorf.

8 recordsLinked to original sources
PubMed2004

Ultrasound training: the virtual patient.

OBJECTIVE: To evaluate an ultrasound training system designed to standardize teaching and learning of gynecological sonography using a virtual model. METHODS: The 'virtual patient' was based on a three-dimensional freehand ultrasound system that allows two-dimensional sonographic offline investigations of previously recorded cases, imitating a real gynecological scan. In the first test phase designed to check the congruence of real and virtual scans, 25 doctors experienced in ultrasound examined three virtual cases. During the second test phase we assessed whether training with the virtual patient helped to establish a satisfactory practical knowledge of gynecological ultrasound. This phase was carried out with 24 medical students without ultrasound experience. RESULTS: All 25 doctors successfully investigated the three cases and generated an accurate diagnosis for the first and second cases. In the third case 14 doctors made the correct diagnosis (uterus bicornis). The measurements of endometrial thickness and the diameter of a fibroid yielded acceptable results compared with the original investigation. After a short standardized video-based instruction, all 24 medical students were able to perform a basic transvaginal scan and to inspect the uterus, ovaries and the urinary bladder. Measurements of endometrial thickness by all students deviated minimally from the actual measurement. CONCLUSIONS: Training with the virtual patient appears to be comparable to performing a live gynecological ultrasound investigation and allows standardized ultrasound teaching and learning.

Computer Simulation↗
PubMed2003

[Uterine fibroids--therapy from the point of view of the gynaecologist].

Uterine fibroids are the most common benign tumour affecting the female reproductive tract, 20% of all women older than 35 years are afflicted. Patients with fibroids tend to be asymptomatic, but fibroids may lead to meno-, metrorrhagia, hyper- and dysmenorrhoea and urination and defecation problems. If the fibroids do not cause any clinical symptoms and if there is no suspicion of a malignant tumor, there is no need for therapeutic intervention. Otherwise, besides the medical management with gestagenes and GnRH (gonadotropin-releasing hormone) analog, surgery represents the classical treatment. Hysterectomy is the common approach for women with completed family planning. For women who wish to conserve their fertility enucleation of the fibroids can be considered. These surgical procedures can be performed endoscopically or abdominally. Uterine artery embolisation, a radiological intervention, is less invasive and represents an interesting therapeutic alternative.

Adult↗
PubMed2003

[Sonographically guided percutaneous needle aspiration of breast abscesses - a minimal-invasive alternative to surgical incision].

AIM: The current standard treatment of breast abscesses is surgical incision and drainage. This method, however, frequently yields poor cosmetic results. Sonographically guided percutaneous aspiration of breast abscesses and local antibiotic treatment need to be considered as an interesting alternative. The present study aimed to compare these treatment alternatives. METHOD: The patient population analysed comprised 24 patients with 28 breast abscesses who presented to the Department of Obstetrics and Gynaecology of Munich University Hospital Grosshadern between 12/1997 and 9/2002. 25 % of these patients (6/24) suffered from a puerperal and 75 % (18/24) from a non-puerperal breast abscess. The study group of surgically treated patients comprised 15 women (16 abscesses). Ten patients (10 abscesses) were treated with the novel, minimally invasive method. The treatment success was statistically analysed using chi (2)- and t-Tests (p < 0,05). RESULTS: The minimally invasive approach did not extend the length of intravenous antibiotic treatment or hospital stay and did not lead to an increase in the need for analgesic drugs. We encountered recurrent abscesses in 31 % (5/16) of the surgical treatment group, yet none in the group undergoing minimally invasive treatment. The aesthetic-cosmetic as well as the functional result in lactating patients was satisfactory in all cases. CONCLUSION: Sonographically guided percutaneous aspiration of breast abscesses represents a less invasive and very promising alternative to surgical incision, showing the following advantages: no general anaesthesia required, a superior cosmetic result and shorter hospitalisation. The method was highly accepted by all patients treated.

Abscess↗
PubMed2002

[Risk of thromboembolism and arteriosclerosis in women].

Young women are at a 3-fold higher risk of experiencing venous thromboembolism compared to young men. This risk is further increased by oral contraceptives, smoking, hereditary thrombophilia and/or low socioeconomic status. There are also hints for gender-specific differences in the arterial system. Coronary heart disease which is particularly important, develops in women 10-15 years later than in men. However, the clinical course in women is often more complicated. In women, thrombophilic predispositions play a more important role before menopause and metabolic risk factors after menopause compared to men. Thrombus formation needs to be initiated by disturbances of at least one element of the Virchow trias. There is principally no difference between men and women. However, all three elements are influenced by estrogen, resulting in gender-specific differences. There is a favorable influence on blood flow by the inhibition of atherogenesis and on the endothelial function by increased NO release, and the unfavorable influence on hemostasis resulting in hypercoagibility. Thus, particularly non-selective hormone replacement therapy for the inhibition of atherogenesis may be questionable due to increased thrombogenicity. The solution may be more selective estrogen receptor modulators. Clinical trials are still needed for both hormone replacement therapy and the therapy of venous and arterial thromboembolism, which have been studied in predominantly male patient cohorts so far.

Adult↗
PubMed1997

Chloroplast F0F1 ATP Synthase Imaged by Atomic Force Microscopy

The F0F1 ATP synthase of chloroplasts was imaged using atomic force microscopy (AFM) in contact mode under physiological conditions. Chloroplast (CF0F1) ATP synthases were reconstituted into liposomes. Liposomes were adsorbed on a mica surface where they spread and formed lipid bilayers containing CF0F1 ATP synthases which could be imaged. From these reconstituted CF0F1 ATP synthases, the CF1 part could be removed either by application of a chemical denaturant or less efficiently by mechanical stripping with the AFM tip. Embedded in the lipid bilayer were seen ring-like structures with a central dimple with outer diameters of 20 +/- 3 nm (chemical denaturant) and ca. 7 nm (mechanical stripping), respectively. Ring-like structures were also observed in a protein-free lipid bilayer. These had diameters of 30 +/- 5 nm and could be clearly distinguished from the structures observed after mechanical stripping. Hence, the ring-like structures observed after mechanical stripping might represent the intrinsic membrane domain CF0 or the oligomer of its subunit III. In addition, isolated CF1 adsorbed directly onto the mica surface was imaged. In accordance with the size known from electron microscopy, a diameter of 13 +/- 4 nm was measured.

Journal Article↗
PubMed1994

Prevention of amino acid racemization during guanidination--a prerequisite for measurement of protein digestibility by homoarginine labeling.

Homoarginine labeling (guanidination) is used to calculate true prececal protein digestibility. A particular worry is that guanidination of proteins at alkaline pH might cause formation of D-amino acids. If D-amino acids show decreased protein digestibility in vivo, as seen in vitro, then the homoarginine method would underestimate protein digestibility. Therefore, the degree of protein racemization was measured during guanidination of casein at pH values between pH 9 and 11 and temperatures between 4 degrees and 65 degrees C. Optimal conditions for the guanidination reaction were 4 degrees C and pH 10.5-11 or 22 degrees C and pH 10. A higher pH value at 22 degrees C or temperatures above 22 degrees C at each pH leads to the formation of appreciable amounts of D-amino acids.

Amino Acids↗
PubMedDate not supplied

[Aspects of early treatment in cleft lip and palate patients].

The Heidelberg Concept of combined surgical otorhinolaryngological and orthodontic treatment of cleft patients starts immediately after birth with the incorporation of an orthopaedic plate. In a study on 38 children with complete unilateral and bilateral cleft lips and palates, maxillary alveolar arch morphology was analyzed by standardized photographs of casts. The importance of early treatment with plates for guided growth and functional coordination is demonstrated.

Cleft Lip↗