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Biomedical subjects

C Scholz

Publications and source records attributed to C Scholz.

At least 73 records · Page 4Linked to original sources
PubMed1995

Glycosylphosphatidylinositol (GPI)-anchored surface antigens in the allogeneic activation of T cells.

GPI-linked surface molecules have recently been described as structures with an activation potential for human T lymphocytes. To study the role of these molecules in T cell activation we analysed GPI-deficient or normal T cells from patients with paroxysmal nocturnal haemoglobinuria (PNH). On activation with allogeneic Epstein-Barr virus (EBV)-transformed B cell lines GPI-deficient freshly separated T cells or continuously growing T cell lines exhibited a significantly lower proliferation or cytokine production compared with their normal counterparts. In contrast, stimulation via the T cell receptor-associated CD3 structure resulted in a comparable response. There was no difference in activation of normal T lymphocytes when GPI-deficient B cells were used as stimulators compared with normal B cells obtained from the same PNH patient. We conclude from these data that GPI deficiency in PNH leads to a functional deficiency of GPI-deficient T cells. In contrast, no difference in activation of T lymphocytes for GPI-deficient cells on the stimulator cell level was observed.

Antigens, Surface↗
PubMed1995

[Experimental therapy of hypoplastic paroxysmal nocturnal hemoglobinuria].

Paroxysmal nocturnal hemoglobinuria (PNH) and aplastic anemia are associated either as a PNH-aplasia syndrome or the emergence of glycosylphosphatidylinositol-(GPI)deficient blood cells in patients with severe aplastic anemia (SAA). It could be demonstrated that SAA patients with GPI-deficient cells in comparison to those without have a worse response to classical immunosuppressive therapy. Therefore, we treated a female PNH patient with severe thrombocytopenia, anemia and granulopenia with G-CSF and cyclosporine. Within 8 weeks, a trilineage response of hematopoiesis was observed. In addition, the proportion of normal to GPI-deficient granulocytes and monocytes increased significantly.

Adult↗
PubMed1995

Histochemical and morphometric study of fiber types in ten skeletal muscles of healthy young adult cats.

A histochemical and morphometric study of fiber types in a variety of skeletal muscles of healthy young adult cats was undertaken to provide normative data not available previously. Using a standardized system of nomenclature, fiber types 1, 2A, 2B, and 2C were identified in most cat muscles on the basis of myosin ATPase staining at pH 4.45. Type-2M fibers were present in temporalis (TEM) and masseter (MAS) muscles. Type-1 fibers predominated in medial head of triceps (MHT) and soleus muscles. Type-2B fibers were dominant in biceps femoris, lateral head of gastrocnemius cranial tibial, long head of triceps, and superficial digital flexor muscles; type-2A fibers were dominant in buccinator muscle samples; and type-2M fibers were dominant in TEM and MAS muscles. Numbers of type-2C fibers did not exceed 2 to 3% of the myofiber population in any muscle. In CT and LHT muscles, a gradient of fiber type distribution was observed, with significant (P < 0.05) increase in numbers of type-1 and type-2A fibers in deeper regions of the muscles. The distribution of fiber types was compartmentalized in MHT and MAS specimens. Diameter of type-2B fibers was significantly (P < 0.05) larger than that of type-1 and type-2A fibers in biceps femoris, lateral head of gastrocnemius, cranial tibial, long head of triceps, and superficial MHT muscles. Diameter of type-2M fibers was significantly (P < 0.05) larger than that of type-1 fibers in TEM and MAS muscles. The soleus type-1 muscle fibers were the largest fibers encountered in any muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1991

Subhemolytic doses of Escherichia coli hemolysin evoke large quantities of lipoxygenase products in human neutrophils.

Polymorphonuclear leukocytes (PMN) have been identified as preferred target cells for Escherichia coli hemolysin in human blood (Bhakdi, S., Greulich, S., Muhly, M., Eberspächer, B., Becker, H., Thiele, A., and Hugo, F. (1989) J. Exp. Med. 169, 737-754). Leukotriene and 5-hydroxyeicosatetraenoic acid generation was investigated in human PMN challenged with E. coli hemolysin in the absence or presence of free arachidonic acid or eicosapentaenoic acid (EPA). In the absence of exogenous free fatty acids, E. coli hemolysin (0.01-10 hemolytic units/ml) induced moderate generation of leukotriene B4 (LTB4) and its omega-oxidation products. The presence of free arachidonic acid (10 microM) during E. coli hemolysin (0.1 hemolytic unit/ml) challenge evoked the generation of large quantities of these products (greater than 100 pmol/1.5 x 10(7) PMN). In parallel, large amounts of 5-hydroxyeicosatetraenoic acid and nonenzymatic LTA4 hydrolysis products appeared. Product release peaked or plateaued 5-10 min after E. coli hemolysin challenge. The presence of exogenous EPA upon E. coli hemolysin challenge resulted in the exclusive generation of LTB5 and metabolites, LTA5 decay products and 5-hydroxyeicosapentaenoic acid. Dose and time dependences corresponded to those with arachidonic acid provision, and the total of EPA-derived products surpassed that of arachidonic acid metabolites in corresponding experiments approximately 2-fold. Increasing the time between free fatty acid provision and E. coli hemolysin challenge resulted in a rapid decline in the generation of arachidonic acid or EPA metabolites. Thus, subhemolytic doses of E. coli hemolysin evoke marked PMN eicosanoid generation that is dependent on exogenous free fatty acid supply, with total amounts approximating those found in calcium ionophore-stimulated neutrophils.

Bacterial Proteins↗
PubMed1991

[Microendoscopy of the Eustachian tube and the middle ear. Indications and clinical application].

Progressive miniaturization of flexible fibreoptic systems has made it possible for the first time to perform atraumatic endoscopy of the Eustachian tube and tympanic cavity with the ear drum intact. With the aid of special actively steerable microcatheters, flexible fibrescopes having outer diameters of 350 to 650 microns are inserted into the opening of the naso-pharyngeal tube and advanced into the tympanic cavity under direct visual control. This new technique is indicated for any disturbance of sound conduction and in those sensorineural hearing disorders in which direct inspection of the middle ear cavity can provide information on the pathogenesis of the disturbance. In the future it may thus replace purely diagnostic tympanoscopy. In combination with fibre-delivery laser systems, this new method forms the basis of "microendoscopically controlled laser surgery" of pathological changes within this anatomical region.

Ear, Middle↗
PubMed1991

[Removal of bone cement with laser].

In operations requiring replacement of cemented endoprothesis, the removal of both the prosthesis and the cement is often difficult as the cement adheres strongly to the bone. Mechanical removal frequently results in fenestration or traumatisation of the bone. The aim of non-contact removal of polymethylmethacrylate (PMMA) with the laser, is to access normally inaccessible regions while inflicting a minimum amount of damage to the bone substance. The much cited cw or superpulsed CO2-laser cannot be used clinically, due to the thermal stressing of the bone. The paper shows spectra of PMMA with and without dopants, e.g. Tinuvin as UV absorber, optical staining with a high-pressure mercury lamp at lambda = 275 +/- 25 nm, lambda = 350 +/- 25 nm and various radiation times, as well as with an excimer laser lambda = 248 nm, FWHM 20 ns, and ablation measurements were made with the following lasers: excimer laser, Lambda Physics, EMG 102, FWHM 25 ns, lambda = 351 nm, excimer laser, Technolas, MAX 10, FWHM 60 ns, lambda = 308 nm, and a pulsed CO2 laser from PSI, lambda = 9.2 and 10.6 microns, FWHM 130 and 65 microseconds, pulse peak power 3.8 and 7.7 kW. The excimer laser, pulse length less than 100 ns, is unsuitable for clinical use because the required removal rate cannot be achieved either with doped PMMA or with pure PMMA. More promising results have been obtained with the pulsed (microseconds range) CO2 laser which has a removal rate of up to 30 times that of the above-mentioned excimer laser, with significantly lower thermal stressing of the bone than with the cw or super pulsed CO2 laser.

Bone Cements↗
PubMed1991

[Fitness assessment and work therapy in a Phase II facility--a case example].

A case example is used to set out the practice of vocational assessment and work adjustment in a medical-vocational, i.e. Phase II, facility. Formulated jointly by the rehabilitation team, the basic therapy objectives, by constant liaison with the employer, are differentiated in view of the future place of work and the performance required from the patient. The individual case serves to illustrate the effectiveness of this therapy approach intended to smoothen the transition from inpatient treatment to vocational reintegration.

Adult↗
PubMed1990

[Endoscopic-controlled laser lithotripsy of salivary calculi. In vitro studies and initial clinical use].

An in vitro study was performed to examine the application of a laser beam for the fragmentation of salivary stones. In accordance with the absorption and reflection spectra of sections of salivary stones, optimal fragmentation was achieved using a pulsed excimer laser with a pulse width of 60 ns and a wave-length of 308 or 351 nm. Further studies on particle size were conducted and a new "sialoendoscope" technique was developed. Twelve patients suffering from a sialolithiasis of the submandibular gland were treated. Under continuous endoscopic monitoring a laser-induced shock wave lithotripsy was performed. In 11 cases complete fragmentation and removal of the salivary stones was achieved. This approach to laser lithotripsy of salivary stones with endoscopic monitoring represents a novel method that permits treatment on an outpatient basis under local anaesthesia, with little inconvenience to the patient.

Calcium Phosphates↗
PubMed1989

[Subjective experience of prenatal diagnosis and genetic counseling].

Two surveys (one involving 650, the other 638 women) based upon interviews about the utilization of prenatal diagnosis by clients are reported. First it is demonstrated which factors obstruct a decision for prenatal diagnosis. Then, a contrast is made between the risk attitude of two groups, namely women who underwent amniocentesis or chorion villi biopsy and those respondents who decided against prenatal diagnosis. Finally, how the examination technique (amniocentesis or chorion villi biopsy) influences the experience of pregnancy is discussed.

Adaptation, Psychological↗
PubMed1989

[Psychosocial aspects of the decision to utilize prenatal diagnosis--results of an empirical study].

After undergoing amniocentesis and delivering their child 504 women were asked by questionnaire for their attitude towards and their experience of pregnancy and amniocentesis. The majority of the women reported that they experienced their decision to utilise amniocentesis as largely unproblematic. In most cases they had already come to a decision before genetic counselling resulting from talking things over with their partner and their gynaecologist. The decision was mostly based on risk assessment and less by considerations of potential consequences of the operation. On the other hand, nearly one-quarter of the respondents found it difficult to decide on their line of action. Their decision was taken more often during or after genetic counselling, and their partner disagreed more frequently with amniocentesis. In this group of women there were more respondents who refused an induced abortion if their child was severely handicapped, than in the group without difficulties with their decision. Disadvantages, consequences of the operation, and conflicts stemming from the social environment of the expectant woman were mentioned as additional reasons for difficulties in arriving at a decision. Potential implications for genetic counselling practice are discussed.

Adult↗
PubMed1987

Spontaneous recovery of ectopic pregnancy: a preliminary report.

Twelve patients with silent (occult) ectopic pregnancy were clinically managed by a non-surgical conservative approach. The laparoscopic findings in 4 patients were not conclusive enough to justify laparotomy, and there was only minimal clinical symptomatology. The serum hCG level in these cases did not exceed 2000 IU/l and no typical rise was found. Serum hCG was measured serially under careful clinical observation until it reached non-pregnant levels over a period of 20-45 days. Tubal patency could be demonstrated 6 months later in 2 patients who desired to become pregnant.

Adult↗