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Biomedical subjects

H Kohlmann

Publications and source records attributed to H Kohlmann.

13 recordsLinked to original sources
PubMed2001

Europium palladium hydrides.

The first fully structurally characterized ternary europium palladium hydrides (deuterides) are reported. The most Eu rich compound is Eu(2)PdD(4). Its beta-K(2)SO(4) type structure (space group Pnma, a = 749.47(1) pm, b = 543.34(1) pm, c = 947.91(1) pm, Z = 4) contains tetrahedral 18-electron [PdD(4)](4)(-) complex anions and divalent Eu cations. The compound is presumably nonmetallic and shows paramagnetic behavior (mu(eff) = 8.0(2) mu(B)) with ferromagnetic ordering at T(C) = 15.1(4) K. A metallic compound at intermediate Eu content is EuPdD(3). It crystallizes with the cubic perovskite structure (space group Pm3m, a = 380.01(2) pm, Z = 1) in which palladium is octahedrally surrounded by fully occupied deuterium sites. Metallic hydrides at low Eu content form by reversible hydrogen absorption of intermetallic EuPd(2) (Fd3m, a = 775.91(1) pm, Z = 8). Depending on the experimental conditions at least three phases with distinctly different hydrogen contents x exist: EuPd(2)H(x) ( approximately )(0.1) (a = 777.02(2) pm, Z = 8, T = 298 K, p(H(2)) = 590 kPa), EuPd(2)H(x) ( approximately )(1.5) (a = 794.47(5) pm, Z = 8, T = 298 K, p(H(2)) = 590 kPa), and EuPd(2)H(x) ( approximately )(2.1) (a = 802.1(1) pm, Z = 8, T = 350 K, p(H(2)) = 610 kPa). All crystallize with cubic Laves phase derivative structures and have presumably disordered hydrogen distributions.

Journal Article↗
PubMed1996

Perioperative analysis of vitreous cell components by immunoimpression cytology.

BACKGROUND: Perioperative analysis and classification of vitreous cell components needs a quick method sufficient to prepare both single cells and cellular membranes. METHODS: In an attempt to clarify the usefulness of immunoimpression cytology we examined 82 eyes with proliferative vitreoretinopathy, proliferative diabetic retinopathy, perforating injuries and contusions. RESULTS: With this method it is possible to perioperatively obtain cells from surfaces of vitreous membranes as well as single cells in suspension. After staining, various cell types could be differentiated morphologically and on the basis of antibody response to cell markers. We found single cells reacting with the antibodies 27E10 (4 positive of 14 tested), vimentin (2/12), RM 3/1 (2/15), LCA (1/ 11) and, particularly, with antiproliferating cell nuclear antigen (9/18). CONCLUSION: With immunoimpression cytology it is possible to determine cell surface markers rapidly and accurately from specimens obtained at the time of vitrectomy. The clinical utility of this test will be ascertained by future studies.

Antigens, CD↗
PubMed1996

[Sudan staining of impression cytology retinal specimen].

BACKGROUND: Long-term silicone oil tamponade may cause increased numbers of vacuoles in the retina. Conventional methods of histological preparation dissolve silicone oil and optically empty spaces are seen. METHOD: We examined the retinas of 20 human eyes after silicone oil injection. We obtained the material by peripheral retinectomies during vitrectomy for recurrent retinal detachment. The material was prepared by impression cytology. The time between silicone oil injection and vitrectomy was 3-18 months. The non-fixed cell sheets were stained with Sudan III, followed by a counterstaining with hematoxyline. RESULTS: Sudan III stained silicone oil 1000 mPa orange-yellow. Sudan-III-stained vacuoles in the retina were found in eight eyes with intraocular silicone oil instillation; in five of these eyes an emulsification of silicone oil was observed. The staining of retinal vacuoles seemed to be caused by the presence of silicone oil in the vacuoles. CONCLUSIONS: Using impression cytology and the Sudan staining procedure, it was possible to stain vacuoles in non-fixed retinal preparations. A long-term silicone oil tamponade induces these vacuoles in the retina, especially if the silicone oil is emulsified. In order to prevent this complication, removal of emulsified silicone oil should be performed as early as possible.

Adolescent↗
PubMed1995

[Morphologic changes in the lens epithelium in patients with age-induced cataract, radiation and steroid cataract and cataract following eye contusion].

The lens epithelium of the human eye plays a crucial role in the pathogenesis of primary and secondary cataract. Sixty hematoxylin-eosinstained lens epithelia were examined using a light microscope. Cell parameters were compared to one another in the various age groups of patients, between patients with secondary cataract (radiation cataract, steroid cataract and traumatic cataract) and patients with senile cataract, and between male and female patients. The t-test was used for statistical comparison. The median cell density was 3116.5 cells/mm2. The median nucleus-plasma ratio was 1:2.74. Patients with secondary cataract had a larger medium cell and nucleus area as well as a higher nucleus-plasma ratio and a lower cell density than patients with senile cataract. A part from degenerative and proliferative cell changes we found various cell types. The age of patients and the cause of cataract correlate with morphometric changes of lens epithelium cells. However, there was no correlation between specific cytologic changes and causes of cataract.

Adolescent↗
PubMed1992

[Local 133xenon clearance in the eye and comparative in vitro wash-out time determination in patients with monoclonal gammopathy].

The authors investigated the dependence of the local clearance of 133xenon to the viscosity of the blood. Increase of viscosity of blood compared with decrease of local clearance of 133xenon by patients with monoclonal gammopathy were demonstrated. It was also shown that using the Beta-part of radiation of 133xenon is sufficient for looking for wash-out-times of the anterior eye segment. However, use of 133xenon in isotonic solution is also possible in other ophthalmological diseases for differentiation.

Animals↗
PubMed1992

[Static and dynamic infrared thermometry and thermography in malignant melanoma of the uvea and conjunctiva].

BACKGROUND: Thermometry and -graphy prove asymmetries of the circulation. Contact-free thermometry of the cornea is applied to find out whether this method can contribute to differential diagnosis of ocular melanomas. MATERIALS AND METHODS: Under standardized conditions the temperature of the cornea was measured in 30 patients with malignant melanoma of the choroid and the conjunctiva and 35 healthy subjects. The instruments were a handpyrometer (HPM, Messgerätewerk, Magdeburg) and the thermovision camera of AGA Infrared System, Sweden, with dynamic recording in colour. RESULTS: In healthy subjects there are no significant asymmetries in temperature under standardized conditions. The temperature of the cornea is elevated in both malignant melanomas of the choroid and the conjunctiva. CONCLUSIONS: Thermometry and -graphy of the cornea can contribute to the differentiation of malignant ocular melanomas from other ophthalmological diseases. They are also suited in long term observation of the course of the melanomas.

Body Temperature Regulation↗
PubMed1990

[Birdshot retinochoroidopathy. Case report].

The clinical findings and results of perfusion-pressure videoangiography (PVA) are described in a 50-year old patient suffering from birdshot retinochoroidopathy. PVA according to Ulrich and Ulrich makes it possible to observe the gradual filling of the retinal and choroidal vessels relative to ocular perfusion pressure. The patient's PVA reveals that the fluorescein penetrates the vessel wall in the interstitial tissue in the region of the large choroidal arterioles close to the entry of the short posterior ciliary arteries in the eye. This occurs long before the blood flow has reached the choriocapillaries, i.e., at distinctly lower perfusion pressures than are necessary for filling the leaking choroidal capillaries. The leakage of fluoresceine from the large choroidal arterioles explains the typical birdshot pattern of the fundus.

Blood Pressure↗
PubMed1989

[Infrared thermovision findings in a patient with infiltrating orbitopathy].

The use of infrared thermovision to examine a patient with infiltrative orbitopathy and combined immunodeficiency is described. In addition to a thermic quantification of infiltrated areas of the eyes and face, it proved possible, with dynamic measurement, to define exactly the extent of pathologically increased temperatures. Other applications of infrared thermovision in ophthalmology are discussed.

Adult↗
PubMed1988

[Clinical, secretory and immunologic studies in Terrien disease].

The present paper begins with a description of the clinical picture of Terrien's disease. Using radionuclide dacryography (RND) to determine secretion, reduced tear secretion was found unilaterally in four patients and bilaterally in one (as indicated by the half-lives of the conjunctival drainage curves). In four patients RND failed to reveal any reduction in tear secretion on either side. The slightly elevated IgG values found in the tear fluid are in agreement with the clinically detected signs of inflammation. The serum parameters determined, such as iron, magnesium, and copper levels and the electrolyte, uric acid, and creatinine concentrations were normal.

Adult↗
PubMed1988

[Indications for the interlocking nailing in open fractures].

The history of intramedullary nailing leads us to assume that septic complications arising from the treatment of open fractures through marrow nailing are largely due to reaming and need no longer to a full extent be put down to treatment by locking nailing. Locking nailing of an open fracture (all three degrees) of the femur can be recommended as long as the periosteum is not exposed over large segments, and coverage with soft tissue is possible. Locking nailing of the lower leg can only be recommended with open fractures of the first degree. With fractures of the second and third degrees the fixateur externe is the treatment of choice.

Femoral Fractures↗
PubMed1987

[From the nail/plate to the dynamic hip screw--example of a generation change in implants for para-articular femoral fractures].

In trochanteric fractures of the femur, where operative techniques are preferable to conservative treatment, a change in the choice of implants has taken place over the past years. As several comparative studies show, the traditional system of nail/plate fixation has not been completely replaced by Ender nailing in many surgical departments. The system of nail/plate is, however, losing significance in face of the increasing usage of screwing-systems (such as, for instance, DHS of AO-Dynamic Hip Screw). The possibility of compression during the operation in screwing methods is the decisive factor.

Aged↗
PubMed1987

[Results of radiation therapy in brain metastases with reference to computerized tomography].

Between 1979 and 1985, 193 patients were submitted to radiotherapy of the brain for formation of metastases. A primary irradiation was performed in 159 patients, 34 patients had been treated by surgery. The median survival time after diagnosis of all irradiated patients (40 to 60 Gy within four to six weeks) was 4.9 months, 22% of the patients survived one year. Patients with mammary carcinomas and patients with bronchial carcinomas showed marked differences in median survival times (4.2 and 6.9 months, respectively) and one-year survival rate (11% and 32%, respectively). In histologic examination, the extent of extracerebral formation of metastases was the decisive parameter for survival. At the end of radiotherapy, 47% of patients showed an amelioration in neurologic deficiency, 16% deteriorated. A follow-up by computed tomography with observation periods between four and 34 months was possible in 84 patients. Most of these patients showed improvement in computed tomography during a period of four to twenty weeks after the beginning of radiotherapy. Later on, about two thirds of the controlled patients had again deterioration with local progression or new formation of metastases in spite of total brain irradiation. A long-term normalization (greater than one year) was observed only in patients with mammary carcinomas.

Brain Neoplasms↗