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Biomedical subjects

P Kaufmann

Publications and source records attributed to P Kaufmann.

At least 181 records · Page 10Linked to original sources
PubMed1983

Sequential changes in oligoclonal patterns during the course of multiple sclerosis.

The majority of patients with multiple sclerosis have an abnormality of their spinal fluid immunoglobulins. This alteration is manifested as patterns of diffuse protein bands in the gamma globulin region following electrophoresis. This pattern has been termed one of restricted heterogeneity, or an oligoclonal pattern. We have found changes in the banding pattern of some patients studied longitudinally. Since the significance of these findings may be relevant to the pathogenesis of this notoriously waxing and waning disease, we discuss the importance of methodologies as well as the concept that IgM and IgA may be relevant to the interpretation of these observations.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

[Branchial arch development in the rat and mouse. II. The existence of branchial clefts].

The development of the branchial arch region was examined at 6- to 12-hour intervals in mice embryos at the age of 9.5-11.5 days after conception [middle of embryonal day (ED) 10 to middle of ED 12] and in rat embryos at the age of 10.5-12.5 days after conception (middle of ED 11 to middle of ED 13) using SEM, serial semithin sections and wax plate reconstructions. The 4th branchial groove is always separated from the corresponding pharyngeal pouch by a broad layer of mesenchyme. At no time did we find a membrana obturans in this region. However, during development of the mesenchyme disappears between the branchial grooves and pharyngeal pouches of the first four arches, allowing external ectodermal epithelium to come into contact with the internal endodermal epithelium to form a membrana obturans. In its dorsal parts this membrane is formed by two layers of epithelium, in the ventral portion frequently it consists of only one layer of epithelium. It was not possible to determine whether the latter was derived from ectoderm or endoderm. Degeneration of cells in this ventral part of the membrane leads to openings which we consider to correspond to branchial clefts. The possibility of an artefactual genesis of these membrane ruptures is discussed. The "1st branchial cleft' appears in mice embryos 15 the age of 9.75 days (second of ED 10), the "2nd branchial cleft' appears first at the age of 10.5 days (middle of ED 11), and the "3rd branchial cleft' appears at the age of 11 days (end of ED 11). In the rat, the corresponding developmental stages are seen about 24 h later. Whereas the "lst and 3rd branchial clefts' are demonstrable during a period of maximally 12 h, the "2nd branchial cleft' is present during the developmental period of about 24-36 h. This protracted existence of the "2nd branchial cleft' is possibly related to the occurrence of lateral cervical fistulas and cysts in the region of the second branchial arch.

Animals↗
PubMed1981

[Branchial arch development in the rat and mouse. I. Development of the sinus cervicalis and operculum].

The development of the branchial arch region was studied in mouse embryos at the age of 10-13 days after conception [end of embryonal day (ED) 10 to end of ED 13] and in rat embryos at the age oa 1-14 days after conception (end of ED 11 to nd of ED 14) using SEM and serial semithin sections. Special attention was paid to the development of the cervical sinus and the branchial operculum. In both rodents, a typical operculum was not found. Instead, the caudal branchial arch region was remodeled by a rapid growth of the second branchial arch, the retrobranchial ridge and the epipericardial ridge, thus forming a progressively deeper grove in this region, the sinus cervicalis. The epithelium of the fourth and sixth branchial arches participated in the formation of the vagus placode, which in later stages was depressed into a grove dorsally and lost its connection with the surface. Finally, the second branchial arch and the cardiac bulge fused compressing the third branchial arch, the second and third branchial grooves and the aperture of the vagus placode. A typical vesicula cervicalis, lined by ectodermal epithelium and collecting the second, third and fourth branchial grooves and the glossopharyngeal and vagus placodes, was not found. However, single or multiple slit-like lumina may persist within the epithelial remnants of the second and third branchial grooves and the vagus placode.

Animals↗
PubMed1980

[Problems of distinction of normal, arteficial and pathological structures in mature human placental villi. III. Morphometric studies in rhesus incompatibility (author's transl)].

Sections of human placental villi which were up to 80 micrometer in diameter were examined light microscopically and morphometrically. The villi were obtained by taking an aspiration biopsy of the attached placenta from 20 normal patients at term and from eight patients delivered at or before 37 weeks because of varying degrees of rhesus incompatibility. The distribution of three histological types of villi was determined. The intermediate villi from patients with erythroblastosis showed an increase in number and volume matching the severity of the disease. The intermediate villi also showed an increase in the amount of cytotrophoblasts, in the amount of materno-fetal diffusion surface area, in the thickness of syncytium, and in the number of Hofbauer cells. The terminal villi were not affected by erythroblastosis and the mature end villi showed a relative decrease in number. To obtain these results an optimal fixation technique was required.

Biopsy, Needle↗
PubMed1980

Scopolamine and KCl injections into the caudate nucleus. Overtraining-induced protection against deficits of learning.

To test the hypothesis that extended training of an instrumental task prevents the performance impairments seen after cholinergic and generalized blockade of caudate-putamen complex (NC) activity in animals with a relatively low degree of training, groups of rats were trained to press a lever under a continuous reinforcement schedule for 5, 15 or 25 sessions; The effects of microinjections of scopolamine and potassium chloride into the CN were then assessed. In agreement with early studies in cats, a significant deficit in performance was produced in the animals with a low or medium degree of training, while no changes in learned behavior were seen in the overtained rats. These results show that: (a) normal neural activity of the CN is essential for performance of instrumental behavior during acquisition and early maintenance stages but not after overtraining, and (b) that after extended training the encoding necessary for performance may be transferred to another neural system outside the CN.

Animals↗
PubMed1980

High pressure, diazepam and pH influences on ketamine anaesthesia in the rat.

Ketamine infusion anaesthesia was studied in rats breathing oxygen/helium under hyperbaric conditions from 1 to 90 ATA. No pressure reversal of the analgesic effect was found. Premedication with diazepam failed to improve the analgesic action of ketamine, but influenced the respiratory pattern. Blood-gas analyses showed a marked relationship between arterial pH and the ketamine dose requirement for stable anaesthesia.

Anesthesia↗
PubMed1979

Classification of human placental villi. I. Histology.

The classification of human placental villi was reviewed on the basis of material prepared by means of special methods. The material from in situ normal-term placentae was biopsied by aspiration into glutaraldehyde. The classification was made on the basis of light-microscopic observations of semithin sections, reconstructions from serial sections, and scanning-electron micrographs. The peripheral villous tree is roughly divided into stem (ramuli), intermediate and terminal villi. The intermediate villi may be further subdivided as mature and immature types, which are found between the stem and terminal villi. Some of the terminal villi possess a local specialization described as the neck region. The histological characteristics and the branching pattern of each type are described, and the basis of the proposed classification is discussed.

Cell Membrane↗
PubMed1979

Classification of human placental villi. II. Morphometry.

Villi of placental tissue obtained from normal term placentae at Caesarean section were embedded in Epon. Semithin sections were subjected to morphometry. The villi were first grouped according to the modified classification proposed in the foregoing paper. The parameters examined include villous numbers, size, vascularity, volume of trophoblast and connective tissue. The measured values differ markedly from those obtained from paraffin sections. Statistically significant differences exist between the different types of villi in various parameters, providing further evidence supporting the validity of the structural classification suggested.

Cell Membrane↗
PubMed1979

Oligoclonal immunoglobulins and plasma cells in spinal fluid of patients with multiple sclerosis.

A new modification of polyacrylamide gel electrophoresis (PAGE) was applied to cerebrospinal fluid proteins from patients with multiple sclerosis (MS). The same spinal fluids were also examined by a cytological technique. Over 90% of patients with clinically definite or early probable or latent MS showed abnormal PAGE patterns in the form of oligoclonal gammaglobulin bands. Reactive (atypical, large) lymphocytes or typical plasma cells were found in some patients. In all such cases an oligoclonal pattern was present. The findings of oligoclonal bands provides valuable supporting evidence for the diagnosis of MS in the less definite clinical categories.

Electrophoresis, Polyacrylamide Gel↗
PubMed1978

[Problems of distinction of normal, artificial, and pathological structures in mature human placental villi. II. Morphometrical studies on the influence of the mode of fixation (author's transl)].

Morphometrical relations of human placental villi from 14 normal placentas of the 38th to 42nd week of pregnancy terminated by Cesarean section were examined in relation to the method of fixation. Villous tissue was obtained from central areas of the in situ placenta with intact maternal circulation by means of puncture aspiration and punch biopsy. Further punch biopsies were performed 2, 5, 10 and 20 min after manual removal of the placenta. Semithin sections of these villi were photographed and examined morphometrically. The findings demonstrate clear effects on quantitative data as a result of the period of ischemia between manual removal and fixation of tissue. Significant changes of several parameters (mean trophoblastic volume, size of epithelial plates, volume of connective tissue, volume of fetal vessel lumina, etc.) occur as early as 2 min after separation of the placenta from the maternal circulation. They are mostly related to a collapse of intravillous vessels. The villous branches may be classified according to structure and morphometry, if they have been obtained under optimal conditions of fixation and prior to any vascular collapse.

Biopsy, Needle↗
PubMed1978

[Lightmicroscopical and histochemical studies on the chorionic plate of the mature human placenta (author's transl)].

The chorionic plate of the normal mature human placenta was studied by light-microscopy and enzyme-histochemistry. Thereby the following findings were obtained in the various layers: The enzyme content of the amniotic epithelium refers to a secretory activity. The question with regard to a resorbant activity remains unclarified. The cells of the amnion mesoderm chiefly show the enzymes of the intermediary metabolism. The intermediate layer consists of mesothelium cells which furthermore have also phagocytotic activity. The chorionic plate mesoderm consists of several layers with connective tissue cells of diverse stage of differentiation. In the early embryonic phase they differentiate amnionward from the primary cytotrophoblast layer and still get cellular supply from residual primary cytotrophoblastic cells up to the date of birth. The enzymes of the primary cytotrophoblast cells refer accordingly with a strong activity of G6PDH to proliferation and differentiation. One part of the X-cells embedded in the Langhans fibrinoid stria descends from this primary cytotrophoblast layer; but in part they differentiate also from the Langhans cells of the placental villi surrounded by the fibrinoid stria. According to their different descent, these cells show a varying content of enzymes. The bordering of the chorionic plate to the intervillous space is represented by a rudimentary, syncytotrophoblast layer.

Amnion↗