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Biomedical subjects

H Schmidt

Publications and source records attributed to H Schmidt.

At least 721 records · Page 40Linked to original sources
PubMed1988

The ability of cultivated human skin fibroblasts to store vitamin A. A contribution to the cytogenesis of the Ito cells of the liver.

Cultivated skin fibroblasts were fed with retinol palmitate in a dosage of 100,000, 200,000, or 300,000 I.U. In dependence on the dosage a remarkable uptake and storage of vitamin A can be observed in vitro (27.2, 53.0 or 60.7% of the fibroblasts). Distinctly retinol palmitate storing cells have lost their typical fibroblast-like appearance and are transformed into cells which are comparable to the Ito cells of the liver from the cytomorphological point of view.

Cells, Cultured↗
PubMed1988

Modulation in vitro and in vivo of cytotoxicity but not cellular levels of doxorubicin by the calmodulin inhibitor trifluoperazine is dependent on the level of resistance.

The role of the calmodulin inhibitor trifluoperazine (TFP) in modulating the cellular levels and cytotoxicity in vitro and antitumour effects in vivo of doxorubicin (DOX), was evaluated in progressively DOX-resistant (5- to 40-fold) sublines of B16-BL6 mouse melanoma. In parental-sensitive B16-BL6 cells treated for 3 h, the IC50 of DOX was 0.1 microgram ml-1, and a less than 2-fold enhancement in DOX cell kill in the presence of a noncytotoxic concentration of 5 microM TFP was observed. However, in the DOX-resistant sublines, the IC50 was 0.7 to 5.0 micrograms ml-1 DOX in the absence of 5 microM TFP and 0.3 to 0.7 microgram ml-1 DOX in the presence of 5 microM TFP. The 2- to 7.5-fold decrease in the IC50 of DOX in the presence of 5 microM TFP, was dependent on the level of DOX-resistance in the various sublines. Compared to parental-sensitive cells, a 2-fold decrease in DOX-accumulation was evident only in the 40-fold DOX-resistant subline. Further, maximal enhancement (50%) of cellular DOX accumulation in the presence of 5 microM TFP was observed only in the 40-fold resistant cells treated with 5.0 micrograms ml-1 DOX. Retention of DOX in the 40-fold resistant subline was only 20% lower than similarly treated sensitive cells, and the inclusion of TFP increased DOX retention less than 10-15%. Antitumour studies in mice with experimental pulmonary metastases revealed that although DOX and DOX plus TFP had similar antitumour activity with the parental sensitive B16-BL6 cells, the combination of DOX plus TFP was significantly more effective than DOX alone with the DOX-resistant sublines. No overt toxicity was observed in normal mice treated with doses of TFP, DOX or DOX plus TFP used for in vivo chemotherapy studies. Results from this study suggest that gross cellular DOX levels do not appear to correlate with the magnitude of resistance, and the effects of TFP in modulating DOX resistance is possibly due to mechanisms other than mere alterations in cellular drug accumulation and/or retention.

Animals↗
PubMed1988

[Skeletal changes in 2 German children with aspartylglycosaminuria].

Two sibs showed delayed speech development, motor retardation and coarsening of their features during their second year of life. Radiological examination of the skeleton showed changes of dysostosis multiplex. Both children showed storage vacuoles in peripheral lymphocytes and a typical oligosaccharide-banded pattern on urinary chromatography. The diagnosis of aspartylglycosaminuria was confirmed by the demonstration of reduced activity of the enzyme aspartylglucosaminidase in leukocytes and in cultured fibroblasts. Treatment of this autosomal recessive inherited glycoprotein storage disease is not possible. Early recognition is important for genetic counselling of the family. This paper describes the first recognised cases in German literature.

Amidohydrolases↗
PubMed1988

Human immunodeficiency virus has an aspartic-type protease that can be inhibited by pepstatin A.

The protease encoded by the human immunodeficiency virus (HIV) processes the viral gag and gag-pol protein precursor by posttranslational cleavage. In this study we have demonstrated by site-specific mutagenesis (Asp----Thr) and by pepstatin A inhibition that the recombinant HIV protease is an aspartic-type protease. Furthermore, incubation of HIV-infected H9 cells with pepstatin A inhibited part of the intracellular processing of the HIV gag protein yet had no apparent toxicity on HIV-infected cells during 48 hr of incubation.

Animals↗
PubMed1988

Immunohistochemical, electron microscopic and in situ hybridization evidence for the involvement of lymphatics in the spread of HIV-1.

To investigate the role of the lymphatic vessels and the sinus systems of the lymph node in the spread of HIV-1, we evaluated 15 lymph nodes from patients with persistent generalized lymphadenopathy (PGL). Fifteen lymph nodes taken from patients with follicular hyperplasia not related to HIV-1 infection served as controls. Immunohistochemical and in situ hybridization techniques revealed infected cells within the sinuses and the efferent lymphatics of the PGL lymph nodes. In contrast, infected cells could not be detected within the walls of the high endothelial venules nor in the areas immediately adjacent. The parenchymal side of the marginal sinus was lined by a discontinuous endothelium. Macrophages and lymphocytes were located within the gaps of this endothelium. More importantly, when the enlarged follicle extended as far as the wall of the marginal sinus, the processes of follicular dendritic cells could be seen extending through the gaps into the lumen of the sinus. This suggests that these cells could transport antigens (including HIV-1) from the sinuses directly to the germinal centers. In addition, HIV-1 particles within cytoplasmic vacuoles were seen in infected macrophages located in the submarginal zone. Positive cells were also found in the extrafollicular lymphoid parenchyma, especially in the area between the marginal sinus and the follicles. The observed distribution of the virus-positive cells within the PGL lymph nodes strongly implicates the lymphatic vessels in the spread of HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

High frequency of graft-versus-host-like syndromes following syngeneic bone marrow transplantation.

Occurrence of acute graft-versus-host reactivity-like (GvHR) syndromes has been shown in at least 3 and possibly in 4 further cases of 9 patients with bone marrow transplants from identical twin donors. The diagnosis of GvHR-like syndromes is based on clinical, immunologic, and histologic features indistinguishable from those observed in graft-versus-host disease (GvHD) grades I-III of patients receiving allogeneic major histocompatibility complex (MHC) matched bone marrow transplants. Induction of GvHR-like symptoms appeared to be correlated with reactivated viral infections after bone marrow transplantation (BMT) or, like in animal models, was due to specific conditioning therapy with cyclophosphamide. The high incidence of acute GvHR-like syndromes in the first months after syngeneic BMT suggests inability of the immune system to discriminate appropriately self from nonself antigens during a normal tolerance induction period after grafting.

Adolescent↗
PubMed1988

Glycogen storage disease type I and III and pyruvate carboxylase deficiency: results of long-term treatment with uncooked cornstarch.

Three patients with glycogen storage disease type I (GSD-I), three with glycogen storage disease type III (GSD-III) and one with pyruvate carboxylase deficiency (PCD) could be successfully switched over from continuous nocturnal gastric drip feeding (GDF) to nocturnal feeding with uncooked cornstarch in yoghurt or "quark" (CSF) at the age of 4-20 years. The new kind of therapy is much more convenient for the patients. When followed up to 30 months, patients on CSF showed the same clinical and laboratory findings as during the last two years with GDF. CSF was not introduced to three patients with GSD-I. Two of them refused the permanent starch-yoghurt meals. In the third patient the morning blood glucose concentrations were too variable.

Adolescent↗
PubMed1988

Prevention of CMV infection after BMT in high-risk patients using CMV hyperimmune globulin.

Prophylactic administration of an intravenous cytomegalovirus hyperimmune globulin in bone marrow transplant recipients provided protection against primary as well as reactivated CMV infection in patients considered to be at high risk for cytomegalovirus infections. Forty-one patients were divided in six subgroups according to factors considered to increase the incidence and severity of CMV infections following bone marrow transplantation. All of these patients received blood products from donors not screened for active or latent CMV infections. In spite of this, patients undergoing intensified conditioning therapy or mismatch transplantation, as well as those transplanted in relapse of their leukemia and even patients receiving granulocyte transfusions from donors unscreened for CMV serostatus, were found not to develop primary or secondary CMV infections. Only in the group of patients older than 35 years and among those suffering from severe GVHD six patients were found to have CMV infections, only two a symptomatic form. Intravenous administration of CMV hyperimmune globulin effectively protected even patients at high risk for CMV infection against severe complications of primary infection or reactivation of this virus.

Adult↗
PubMed1988

Significant reduction of cytomegalovirus (CMV) disease by prophylaxis with CMV hyperimmune globulin plus oral acyclovir.

The effect of prophylactic intravenous administration of a cytomegalovirus (CMV) hyperimmune globulin with a high titer of neutralizing antibodies plus oral acyclovir was studied in 93 consecutive bone marrow transplant recipients. In spite of receiving blood products unscreened for CMV only six patients developed CMV infections during the time they received passive immunization. Five patients reactivated virus after hyperimmune globulin infusions were stopped; four of them suffered from chronic graft-versus-host disease (GVHD) Among the patients suffering from acute GVHD grade III/IV and/or chronic GVHD the incidence of CMV infection (10/38) was significantly higher than among those with no or milder forms of GVHD (1/55) (p less than 0.01). Only three patients suffered from symptomatic CMV infections; two with gastrointestinal manifestations and one with fatal CMV pneumonia. Thus CMV prophylaxis as used here proved highly effective in combating one of the major difficulties encountered in BMT.

Acyclovir↗
PubMed1988

[Detection of fibria-like surface structures in Staphylococcus saprophyticus as a pathogen in chronic pyelonephritis].

It is reported on a 25-year-old female patient suffering from chronic pyelonephritis. Six times coagulase-negative staphylococci were bacteriological proved in a significant number. Four strains were identified as Staphylococcus saprophyticus. The in each case in the autumn occurring complaints could be correlated well with the seasonal fluctuations of urinary tract infections by S. saprophyticus as described in the literature. Chemotherapeutic measures be determined by the clinical symptoms and subjective complaints of the patient. By an antibiotic therapy only a temporary loss of complaint and normalization of urinary findings, respectively, were obtained. In the presence of a marked leukocyturia a capsula-fashioned variant of S. saprophyticus was established. By scanning electron microscopy investigations fimbria-like surface structures were detected for the first time in this germ species. Three morphological different appendage structures are described. By a hypothetical model possible functions of these structures in the adherence process are discussed.

Adult↗
PubMed1988

A case of accidental cyclosporin overdose with pharmacokinetic analysis.

In a case of oral overdose of cyclosporin we measured plasma concentrations by radioimmunoassay and high pressure liquid chromatography. We observed unchanged pharmacokinetic parameters after the overdose indicating normal renal and hepatic function. Laboratory findings showed no renal or hepatic damage. As toxic symptoms, only emesis and a short, mild drowsiness were noted.

Bone Marrow Transplantation↗
PubMed1988

[Mediastinal sonography in childhood. Results of 310 studies].

Following the performance of 310 mediastinal ultrasonograms over 3 years in children up to an age of 15 years, the authors report on the indication applied, their methods, and the results. Sonography allows an easy approach to upper and anterior mediastinal structures in children. Thus, differentiation between a normal thymus and malignant infiltration, which is difficult on plain films, is possible in almost all cases without further radiological examinations. Except in the hilar area, sonography is sufficient to detect lymphomas. In patients with congenital stridor a vascular etiology, e.g. an aberrant brachiocephalic trunk, can be visualized or excluded.

Adolescent↗
PubMed1988

[Modification of the phenoloxidase activity of human leukocytes by detergents, studied by histochemical phenoloxidase detection].

Using the histochemical detection for PO the in vitro effect of several detergents was tested. Dimethylsulfoxide, Triton X 100, Sodium desoxycholate, Tween 20, and Cetyltrimethyl ammonium bromide were investigated to check their effects upon the morphology and enzymatic activity of human leucocytes. Cetyltrimethyl ammonium bromide seems to be most suitable for the disintegration of cells. It does not inhibit the PO-activity.

Catechol Oxidase↗
PubMed1988

[DS-1000--a new digital image intensifier film-screen system in thoracic diagnosis].

The characteristics of the DS-1000, a new digital imaging equipment, using an image-intensifier-video-system are described. The digital images are displayed on a monitor with 1024 x 1024 matrix, are stored on a hard disc and can be postprocessed with regard to gray-scale-level and recognition of details. The spatial resolution ist 1,1 Lp/mm, using the 47-cm-image-intensifier. The DS 1000 was employed for chest-examinations. The diagnostic accuracy of 70 selected cases with a great variety of pathologic conditions was verified in comparison to conventional chest films. There was no significant difference in the recognition of normal anatomic structures between the two imaging systems. Pathologic states with low contrast to the surrounding structures (mediastinal and hilar masses, airspace disease, pulmonary nodules) were displayed at least equivalent with the digital technique. The accuracy in recognizing pathologic states with the digital equipment as compared to the conventional technique was inferior for conditions requiring high spatial resolution (subtle interstitial infiltrations, septal lines, scars, subtle calcifications).

Diagnosis, Differential↗