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Biomedical subjects

H Höffken

Publications and source records attributed to H Höffken.

9 recordsLinked to original sources

Hemophan versus hemophan--a philippic against the suggestion of constant membrane quality.

All statements referring to biocompatibility of dialyzers depend on the suggestion of a constant and reproducible structure of the investigated membrane material. The data presented here strike this concepts in case of hemophane. Two commercially available hemophane dialyzers, the GF MC 120 (Gambro) and the MO 450 (SMAD) membranes, were compared. Significant differences could be seen in the induction of leukopenia and leukocyte sequestration reaction within patients lungs, but also in capacity to influence granulocyte oxidative metabolism and release of granular enzymes. According to these data it seems questionable whether hemophane is a membrane material with constant structure and quality normally expected for products bearing trade names. Excluding other differences (like surface-area or sterilization method) variable amounts of DEAE substituents and/or an inconstant distribution of the DEAE groups within the membranes may be the most possible reason responsible for the differences found. The study underlines the urgent need of an exact physico-chemical characterization of dialyzer membranes and is therefore a challenge for free publication of such basic data by the producers.

Biocompatible Materials

[Vaginal metastases as the ist signs of primary occult hypernephroid kidney neoplasms].

Based on the literature and own observations it is pointed out that in cases of vaginal tumors as a rule a consequent search for tumors of the kidneys is necessary, because vaginal tumors may be metastases of primarily not identified hypernephroid carcinomas. The frequency of such metastases is reported to be about 2%. A search for kidney tumors is necessary, if histological findings of the vaginal tumor are clearly suspect for hypernephroid carcinoma, or if it cannot be clearly identified as a primary vaginal tumor or--as a metastasis--gives no certainty to be a metastasis of a primary tumor of other localization. Because of the relative statistical frequency of vaginal metastases from carcinomas of the kidneys a consiliary gynecological check up is necessary if the diagnosis of the tumor was primarily a urologic one to ensure that there are no vaginal metastases. Further diagnostic and therapeutic procedures are discussed.

Aged

Sedimentation velocity separation: a preparation method for cervical samples.

A preparation procedure, aiming at monolayer deposition of cervical exfoliative material on glass slides for high resolution prescreening has been developed. The main features of this procedure are centrifugal deposition after suspension and sedimentation of samples over isopycnic medium of 1.026 density. Fractioning of the separation column after centrifugation at 50 X g yields two preparations with leukocytes, bacteria and cellular debris predominantly located on the first slide and epithelial cells on the second one. The degree of spatial cellular isolation as well as the amount of diagnostically relevant cells per slide seem to fit the requirements of automated high resolution analysis.

Cell Separation

Cytomorphologic results of preparation experiments for monolayer deposition of cervical material.

For automated prescreening methods by high resolution analysis serving as a detecting method in gynecologic mass screening programs a new monolayer deposition method of cervical material has been used. This method will be outlines briefly and the mode of evaluation as well as current cytomorphological findings will be presented. With regard to measurability of the slides prepared according to the new method a number of cytologic criteria were thought to be of particular importance. These criteria are delineated and compiled in a table. A form in which these criteria were listed was filled in by cytopathologists for each slide evaluated. When performing isolation and centrifugation procedures several new morphologic questions arose to the cytopathologist which can only partly be answered by now. If taking into account all criteria of evaluation it may be followed from the present experiences that slides of cervical material are much more suited for automated prescreening methods by high resolution analysis if prepared after isolation and centrifugation in macromolecular liquids than are conventional Papanicolaou smears or slides from suspensions with isolated cells that were not subjected to centrifugation procedures.

Cell Separation

[Comparison of cytological features in keratinizing dysplasia and keratinizing squamous carcinoma (author's transl)].

By means of the literature pathological aspects of the keratinizing dysplasia and the keratinizing squamous cell carcinoma are discussed. It has been tried to point out cytological criterias by means of which a differential diagnosis can be performed between the two lesions. The difficulties of this task are mentioned. To give examples for the diagnostic criterias pictures of our own material are demonstrated. Criterias for differential diagnosis of the two lesions are summarized in a table. By the use of all criterias mentioned above a differential diagnosis can be performed cytologically in most cases. Cytological findings should be described as precisely as possible. It is only in this way that the best information can be given to the clinician referring to diagnostical or therapeutical procedures that should be performed further on.

Carcinoma, Squamous Cell

[Cytology of reversible and irreversible epithelial changes in the uterine cervix].

The etiology and the experimentally founded concept of pathogenesis of reversible and irreversible epithelial changes of the cervix uteri are described. The possibilities and limitations of differential diagnosis of dysplasia, carcinoma in situ, and invasive carcinoma are discussed. Cytological criteria of differential diagnosis are mentioned and summarized in table form. Rates of regression, persistence and progression of different forms of dysplasia as potential forerunners of invasive carcinoma are mentioned. By the use of all cytological parameters a primary differential diagnosis of the mentioned lesions may be reached to a degree of 90% (Patten 1969; Wied et al. 1976). Diagnostic findings should be precisely formulated to give the best information for further diagnostic or therapeutic procedures concerning the individual case.

Carcinoma in Situ

Components and results of a new preparation technique for automated analysis of cervical samples.

Components and evaluations of a new preparative procedure for automated high-resolution analysis of cervical samples are presented. This procedure is based on sedimentation velocity separation of samples with subsequent fractionation of the separation column and centrifugal deposition of suspended cells on coated glass slides. A system for specimen collection and mailing of suspended samples is described. A new type of glass slide designed for automated analysis is presented, and centrifugal buckets for cell deposition on a 6-sq-cm area are described. Experimental results with different kinds of coating substances for glass slides as well as different isopyknic media are discussed, and data for differential cell counts are graphically demonstrated. Looking at the diagnostic accuracy and economic feasibility of this system, the authors realize that preparations have to be evaluated quantitatively and that constraints of sample size and processing time have to be taken into consideration for further developments.

Autoanalysis