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Biomedical subjects

B Claus

Publications and source records attributed to B Claus.

12 recordsLinked to original sources

Chédiak-Higashi-Steinbrinck syndrome (CHS) in a 27-year-old woman--effects of G-CSF treatment.

Chédiak-Higashi-Steinbrinck syndrome (CHS) is a rare autosomal recessive disorder which is usually lethal in early childhood. Diagnostic hallmark is the occurrence of giant inclusion bodies in peripheral leukocytes and their bone marrow precursors. We report on a 27-year-old female patient who was admitted for treatment of a skin abscess. She recovered after intravenous antibiotic treatment and surgical incision. Hematological investigation was initiated because of a persisting neutropenia of 15%, with a leukocyte count initially in the normal range but subsequent leukopenia. Case history revealed recurrent skin infections from childhood on, regularly requiring surgical intervention. One year prior to admission a neuropathy had been diagnosed, while a partial albinism had been known for years. Microscopic examinations of peripheral blood and bone marrow aspirate smears were diagnostic for CHS. Additionally, a secondary antibody deficiency was found. Normalization of the white blood cell count, including the differential count, was observed following initiation of G-CSF treatment. Functional assessment of phagocytosis and oxidative burst activity of granulocytes revealed normal results before and after stimulation with G-CSF, however, natural killer cell activity was only weak, with slight improvement after G-CSF treatment in vivo. Cytogenetic analysis showed a normal female karyotype. Although the haploidentical brother of the patient may serve as an allogeneic stem cell donor, transplantation has been postponed because of further deterioration of her already existing CHS-specific neurological impairment. Nevertheless, while receiving G-CSF maintenance treatment our patient experienced no further infectious episodes within 6 months after diagnosis of CHS.

Adult↗

[Egocentric inference of object positions during reading and listening].

Subjects read narratives describing several objects surrounding a protagonist. In taking the protagonist's perspective, subjects constructed egocentric mental models of the described object configurations. During the test phase, the mental model had to be updated according to reorientations of the protagonist. We examined if objects are localized immediately within the egocentric reference frame of the mental model, even if they are not linguistically localized relative to the protagonist, that is, if egocentric object positions have to be inferred. In two experiments, narratives and test items were presented either visually or aurally. In a third experiment, narratives were presented visually but test items were presented aurally. We found that recipients tended to localize every object immediately within the egocentric reference frame. But since reading interferes with updating of the mental model, subjects did not localize every object egocentrically if visual presentation was used throughout.

Auditory Perception↗

Human meniscal proteoglycan metabolism in long-term tissue culture.

For the purpose of human meniscal allografting, menisci have been maintained viable in in vitro culture. The influence of long-term tissue culture on the extracellular matrix metabolism of the meniscus has been studied. Fetal calf serum (FCS) was used as a supplement for the growth factors necessary to maintain optimal meniscal cell metabolism. A series of semilunar cartilage samples was cultured under serum-free conditions since foreign proteins could be responsible for immunological problems after eventual allografting. The proteoglycan metabolism in human menisci cultured in FCS-supplemented and in serum-free culture media was compared. To rule out any influence of topographical variations in glycosaminoglycan (GAG) content on proteoglycan (PG) metabolism, GAG concentrations within the tissue were determined, and sulphate (35S) incorporation was studied in tissue samples with a comparable biochemical composition. Sulphate incorporation was preserved when 20% FCS was added to the nutrient medium. The meniscal tissue fibroblasts continued to produce 35S-PG during 4 weeks of culture. The PG molecules were shown to consist of PG-aggregates, monomers and a low molecular-weight PG population. Newly synthesized GAG consisted of approximately 55% chondroitin 4- and 6-sulphate and 33% dermatan sulphate. In the presence of serum, 35S incorporation in PG and in the PG-aggregate fraction significantly increased during the first 2 weeks and then decreased during the following 2 weeks of in vitro culture. Newly synthesized PG-aggregates were almost entirely accumulated in the tissue during these weeks. In the 3rd week the values for this parameter decreased slightly. 35S-PG synthesis dramatically declined after 4 weeks of in vitro culture. Catabolism probably resulted in increased proportions of 35S-PG in the incubation media. In the absence of serum, 35S-PG production also increased in the 2nd week of culture. However, 35S activity was almost exclusively found in small PG, and this material apparently diffused to the incubation media. Consequently, catabolism is higher, and the immobilization of 35S-PG is poor when FCS is not added to the culture media. Our findings suggest that menisci are maintained in viable condition and may serve for allografting at least during 2 weeks of tissue culture.

Adult↗

[Viable meniscus transplantation].

The integrity of the semilunar cartilages has proved to be the best safeguard against mechanical degenerative changes. One can postulate that restoring normal congruency between the femur and tibia with intact menisci would be the ideal solution to many mechanical knee problems. Several semilunar cartilages have been transplanted with good functional results in medial and lateral compartmental meniscal disease. However, this form of chondroprotection in the load-bearing area of the femur and tibia can only be properly evaluated after 10 to 20 years of follow-up. In order to obtain functional results, meniscal allografts have to be incorporated in the knee joint by intimate meniscofemoral synovial bonding. The synovial fibroblasts must grow into the collagen meshwork of the meniscal allograft. Such ingrowth has been shown in freeze-dried and deep-frozen meniscal allografts. However, in a small number of transplants shrinking has been observed on repeat arthroscopy at 6 months. Satisfactory incorporation of meniscal allografts has been obtained with fresh allografts, but availability remains a problem when this method is used for meniscal substitution. For this reason viable meniscal allograft implantation was initiated in a series of 25 patients and the value of this method studied. The meniscal allograft can be kept in an adequate semisynthetic nutrient medium for approximately 2-3 weeks without apparent loss of viability, during which period the appropriate recipient can be selected and prepared, a thorough laboratory screening can be conducted, and the culture results and disease transmission factors can be evaluated. In this way, live transplant hazards can be avoided, resulting in a higher success rate.

Adult↗

The Harris-Galante cementless acetabular component: results in 190 cases with at least 3 years follow-up.

The results of 190 primary total hip arthroplasties with a Harris-Galante cementless acetabular cup were reviewed. All patients had a minimum follow-up of 3 years (range, 3 to 5.5 years, mean 46 months). Clinical and radiographical analysis was performed. Inguinal pain was recorded in five cases. We noted a fracture of a screw in four cases without further implications. There was no evidence of acetabular loosening. There was no migration of the acetabular cup. No acetabular component showed measurable wear of the polyethylene liner. Non-progressive radiolucent lines were recorded in 14% of the patients: among these patients, radiolucent lines were noted in zone 1 in 46%, in zone 2 in 4% and in zone 3 in 86%. Two socket revisions became necessary. One patient suffered a deep-seated infection. Another revision was necessary because of recurrent dislocation.

Acetabulum↗

Sr-90 transfer factors for rye in podzolic soils: dependence on soil parameters.

The transfer factor (TF) for Sr-90 was studied in 10 rye fields with podzolic soils near Bremen. Values between 0.10 and 0.30 were obtained with a mean of 0.18. The TF was correlated with various soil parameters (pH, organic matter, K, Ca and P content). Negative correlations were found between TF and pH-value, Ca and P content. However, the content of organic matter in the soils was positively correlated with soil and grain activity (Bq/kg).

Biological Transport↗

[Cardiac arrhythmias and other complications in patients after myocardial infarction during a long term training program].

In 85 patients with myocardial infarction undergoing a physical training on a bicycle ergometer 3 times a week over a period of 18 months beginning 5 weeks after the acute infarction, telemetric and haemodynamic investigations were made. The telemetry was done during ergometer training, dynamic and isometric gymnastics and during work at home. The diastolic pulmonary arterial pressure under exercise was registered in 43 patients before the beginning of the training program; in 16 of these patients a control heart catheterization was made after a training period of 4 months. During the ergometer training program 32% of all patients had ventricular premature beats more than 1:10, 6% had paroxysmal ventricular tachycardias, 1 patient had supraventricular tachycardias and 1 patient died at home after having a tachycardia of unknown origin. During dynamic or isometric gymnastics or under work at home the patients had not more arrhythmias than in the telemetric controls during the ergometer training. Arrhythmias and other complications are very often found in patients with high diastolic pulmonary arterial pressure in the exercise test.

Adult↗

[Humoral immune reaction in chronic liver diseases].

In 60 patients with a morphologically ascertained chronic liver disease and 40 hepatologically examined patients with a healthy liver of a control group the quantitative determination of the immunoglobulin and the immunofluorescence-serological determination of antibodies against nuclei, smooth musculature and mitochondria were carried out. Only in one female patient with a chronic active hepatitis out of 51 patients with morphologically ascertained liver cirrhosis or chronic active hepatitis antibodies against nuclei and smooth musculature in a level of the titre of more than 1 : 40 and only in 2 female patients with a primary biliary cirrhosis antibodies against mitochondria could be proved in a level of the titre of more than 160. Titres of antibodies lying below were found in the group of patients with liver diseases and the control group in the same frequency, so that an autoimmune form of the cryptogenic cirrhosis could not be differentiated. The proof of antibodies against nuclei and smooth musculature of a high titre in connection with an isolated increase of the IgG is of special diagnostic importance for the autoimmune form of the chronic active hepatitis; the same is the case in the proof of antibodies against mitochondria of a high titre in connection with an isolated increase of IgM.

Adult↗