Search PubMed⌕ Search

Biomedical subjects

H Schild

Publications and source records attributed to H Schild.

At least 217 records · Page 12Linked to original sources
PubMed1990

Isolation and analysis of naturally processed viral peptides as recognized by cytotoxic T cells.

Virus-infected cells can be eliminated by cytotoxic T lymphocytes (CTL), which recognize virus-derived peptides bound to major histocompatibility complex (MHC) class I molecules on the cell surface. Until now, this notion has relied on overwhelming but indirect evidence, as the existence of naturally processed viral peptides has not been previously reported. Here we show that such peptides can be extracted from virus-infected cells by acid elution. Both the naturally processed H-2-Db-restricted and H-2-Kd-restricted peptides from influenza nucleoprotein are smaller than the corresponding synthetic peptides, which have first been used to determine the respective CTL epitopes. As with minor histocompatibility antigens, occurrence of viral peptides seems to be heavily dependent on MHC class I molecules, because infected H-2d cells do not contain the H-2-Db-restricted peptide, and infected H-2b cells do not contain the H-2-Kd-restricted peptide. Our data provide direct experimental proof for the above notion on MHC-associated viral peptides on virus-infected cells.

Amino Acid Sequence↗
PubMed1990

[Focal liver lesions as incidental findings. 2: Diagnostic procedures in sonographically homogeneous echo-rich, echo-poor or inhomogeneous lesions].

Hemangioma is one of the most common incidental findings in the ultrasonographic image. In 80% to 90% of the cases, the hemangioma presents as a homogeneous lesion in the US image. In asymptomatic patients and a lesion diameter of less than 2 cm, further clarification additional to ultrasonography is not necessary. Major differential diagnoses are focal nodular hyperplasia, metastasis, hepatocellular carcinoma and liver cell adenoma. With exceptions, the biological significance of echo-poor or inhomogeneous lesions cannot be established on the basis of the US image. In such cases, additional diagnostic procedures are required.

Angiography↗
PubMed1990

[Focal liver lesion as an incidental finding. 1: Diagnostic management--procedure in sonographically echo-free tumors].

The spread of diagnostic ultrasound has led to an increase in the incidental detection of lesions of the liver in patients with unrelated symptoms and no history of tumor disease. In this article, suggestions are made on how to proceed with the further diagnostic workup of such patients. In part 1 these suggestions are aimed at identifying patients who might benefit from further investigation, while at the same time avoiding unnecessary procedures.

Biopsy↗
PubMed1990

Limit of T cell tolerance to self proteins by peptide presentation.

Cytotoxic T lymphocytes (CTLs) recognize foreign peptides bound to major histocompatibility complex (MHC) class I molecules. MHC molecules can also bind endogenous self peptides, to which T cells are tolerant. Normal mice contained CTLs specific for self peptides that were from proteins of ubiquitous or tissue-restricted expression. In vivo, these endogenous self peptides are not naturally presented in sufficient density by somatic cells expressing MHC class I molecules. They can, however, be presented if added exogenously. Thus, our data imply that CTLs are only tolerant of those endogenous self peptide sequences that are presented by MHC class I-positive cells in a physiological manner.

Animals↗
PubMed1990

[Color-coded Doppler sonography of primary and secondary liver tumors].

50 Patients with 78 focal liver lesions were examined via colour-coded Doppler system to study the vascularity of metastatic lesions and primary benign and malignant liver tumours. According to the amount of detectable colour Doppler signals, tumour vascularity was graded into 4 types. Metastases (n = 40) and cavernous haemangiomas (n = 12) seemed to be avascular with no evidence of increased vascularity (Type I/II). Conversely primary liver cancer (PLCA) (n = 7) and focal nodular hyperplasia (FNH) (n = 16) mainly produced arterial Doppler signals within the tumour (Type III/IV). AV shunts and partial portal vein thrombosis could be demonstrated in PLCA. Doppler colour flow imaging for detection of tumour vascularity may thus add to the specificity of ultrasonic tumour diagnosis.

Adenoma↗
PubMed1990

[High-resolution thin-section CT in the preoperative staging of rectal tumors: a comparison with endoluminal sonography and histology].

Rectal carcinomas are amongst the most common malignant tumours. The aim of this work was to determine whether high resolution CT with thin sections (1 mm) can provide satisfactory delineation of perirectal tumour infiltration. Correct determination of local tumour spread was possible in four out of nine patients and distinction between those tumours confined to the rectal wall and those infiltrating the perirectal tissues was possible in four out of eight patients.

Aged↗
PubMed1990

[Functional angiography of the arteries near the knee joint: consequences for stent implantation?].

Angiographic studies of the arteries adjoining the knee in 25 patients show extensive kinking and stenoses of the popliteal artery and less frequently of the distal femoral artery during flexion of the knee joint. This is due to the loss of elasticity with increasing age forcing the vessel into a tortuous course during shortening of the pathway of the popliteal artery with knee flexion. Independent of the principle of the different stents available they probably will not increase the contractility of the stented vessel in the longitudinal axis. It is to expect that after implantation of stents into the popliteal artery kinking will occur predominantly in the original segments of the vessel and at the transitions to the stented segments leading to intimal damage by shear forces thus propagating local progress of atherosclerosis.

Adult↗
PubMed1990

[Local fibrinolysis in renal artery occlusion].

The indications and technique of local fibrinolysis therapy of acute renal artery occlusions are discussed in relation to four patients. Because of the short period for which ischaemia is tolerated by the kidney, the result of treatment depends largely on the time interval between occlusion and the beginning of treatment. Partial perfusion of the renal artery was obtained in three patients. Since the "ischaemia time" of the kidneys had been exceeded, it was not possible to obtain complete restitution of renal function in any of these patients.

Adult↗
PubMed1990

[The behavior of collaterals during percutaneous transluminal angioplasty].

The fate of 106 collaterals was investigated following percutaneous transluminal dilatation of 113 stenoses and occlusions. Following dilatation, 78% of collaterals were unchanged and 22% could no longer be demonstrated. The success of the dilatation had no bearing on the fate of the collaterals. Collaterals beginning or ending in a dilated portion of vessel disappeared more frequently (30%) than the others (11%). Following five dilatations, some vessels were demonstrated in the area of stenosis, which had not been demonstrated previously. Evidently local events, such as displacement of arteriosclerotic plaques may lead to occlusion or reopening of vessels. Remaining collaterals may be of great importance in saving a limb if there is an acute occlusion complicating a dilatation.

Angioplasty, Balloon↗
PubMed1990

[Possibilities of computerized arthrotomography in the diagnosis of shoulder instabilities].

Shoulder instability can usually be diagnosed by examination of the history and a careful physical examination. Additional diagnostic studies include radiographic investigations and arthroscopy as a functional and very comprehensive diagnostic procedure for shoulder lesions. Conventional radiographic investigations with special projections have proven to be reliable in revealing bony changes of the glenoid and of the humeral head, whereas CT arthrography is very helpful in evaluating capsulolabral lesions associated with shoulder instability. This kind of investigation is a highly sensitive and less invasive technique. Combined with intraarticular application of contrast medium the extent of pathologic changes associated with instability can be imaged and differentiated from other intraarticular causes of dysfunction. During a 1-year period, 42 patients were studied by double contrast arthrography followed by CT examination, and 33 were found to have a shoulder instability. The intention of this report is to describe a few CT arthrographic findings in the presence of pathologic anatomy of unstable shoulders.

Adolescent↗
PubMed1990

[Computerized tomography findings in hormonally inactive adrenal gland tumors].

CT examinations of 6 years served as basis for the incidence of hormonally inactive space-occupying masses at the adrenal. Of a total of 25,000 patients, 313 (1.3%) suffered from disease of the adrenals, and of these 261 patients had a hormonally inactive adrenal tumour. Adenomas were the most frequent space-occupying growths (101 patients), followed by metastases of the adrenals (77 patients), whereas adrenal carcinomas (4 patients), myelolipomas (3 patients), ganglioneuromas (3 patients) adrenal cysts (3 patients) and adrenal haemorrhages (2 patients) were rare findings.

Adenoma↗
PubMed1989

In vivo priming of virus-specific cytotoxic T lymphocytes with synthetic lipopeptide vaccine.

Cytotoxic T lymphocytes (CTL) constitute an essential part of the immune response against viral infections. Such CTL recognize peptides derived from viral proteins together with major histocompatibility complex (MHC) class I molecules on the surface of infected cells, and usually require in vivo priming with infectious virus. Here we report that synthetic viral peptides covalently linked to tripalmitoyl-S-glycerylcysteinyl-seryl-serine (P3CSS) can efficiently prime influenza-virus-specific CTL in vivo. These lipopeptides are able to induce the same high-affinity CTL as does the infectious virus. Our data are not only relevant to vaccine development, but also have a bearing on basic immune processes leading to the transition of virgin T cells to activated effector cells in vivo, and to antigen presentation by MHC class I molecules.

Amino Acid Sequence↗
PubMed1989

[Angioplasty of the subclavian artery. The technic, early and late results].

Percutaneous transluminal angioplasty (PTA) was performed in 22 patients (13 women and nine men; mean age 57 years [44-74] ) with symptomatic obstruction of the subclavian artery which was due to arteriosclerotic stenosis in 14, occlusion in six patients, radiogenic multiple stenoses in one (after radiotherapy for breast cancer), and stenoses of the left and right subclavian artery in one patient with Takayasu's arteritis. Primary success occurred in 21 (91%). The only complication was a stenosis of the brachial artery after combined brachiofemoral recanalization of a subclavian artery occlusion, but it did not require treatment. No emboli were noted. A good long-term result was achieved in 19 of the 21 primarily successful PTAs, in two instances after repeat PTA. PTA has thus been shown to be a simple, well tolerated interventional treatment of symptomatic subclavian obstruction with a high success rate and low risk of complications. It is to be preferred as a primary procedure to surgical intervention.

Aged↗
PubMed1989

Modification of tumor cells by a low dose of Newcastle disease virus. II. Augmented tumor-specific T cell response as a result of CD4+ and CD8+ immune T cell cooperation.

Augmented tumor-specific T cell responses were observed against the high metastatic murine lymphoma variant ESb when using as immunogen ESb tumor cells that had been modified by infection with a low dose of Newcastle disease virus (NDV). Such virus-modified inactivated tumor cells (ESb-NDV) were potent tumor vaccines when applied postoperatively for active specific immunotherapy of ESb metastases. We demonstrate here that immune spleen cells from mice immunized with ESb-NDV contain enhanced immune capacity in both the CD4+, CD8- and the CD4-, CD8+ T cell compartments to mount a secondary-tumor-specific cytotoxic T cell response in comparison with immune cells from mice immunized with ESb. ESb-NDV immune CD4+, CD8- helper T cells also produced more interleukin 2 after antigen stimulation than the corresponding ESb immune cells. There was no participation of either CD4+ or CD8+ virus-specific cells in the augmented response. The specificity of the T cells for the tumor-associated antigen remained unchanged. Thus, there is the paradox that the virus-mediated augmentation of the tumor-specific T cell response in this system involves increased T helper activity but does not involve the recognition of viral epitopes as potential new helper determinants.

Animals↗
PubMed1989

Protein-specific cytotoxic T lymphocytes. Recognition of transfectants expressing intracellular, membrane-associated or secreted forms of beta-galactosidase.

BALB/c-derived tumor cells were transfected with recombinant Escherichia coli beta-galactosidase (beta-gal) genes which were inserted into IgM heavy chain gene derivatives, leading to expression of the resulting fusion protein in different cellular compartments. A beta-gal-specific, major histocompatibility complex (MHC) class I-restricted CD8+CD4- cytotoxic T lymphocyte (CTL) line of BALB/c origin raised against one transfectant expressing cytoplasmic beta-gal also lysed transfectants expressing beta-gal as membrane-inserted fusion protein, as well as transfectants secreting beta-gal. Our data show that MHC class I-restricted CTL can recognize fragments of nonviral cellular proteins, be they expressed as intracellular, membrane-inserted, or secreted products. The findings confirm and extend a hypothesis on the nature of minor histocompatibility (H) antigens formulated earlier.

Animals↗
PubMed1989

[Traumatic hip dislocation in childhood].

The article reports on eight cases of traumatic dislocation of the hip in children. Six of these were genuine dislocations and two dislocation fractures. The children were between 5 and 13 years of age at the time of injury. Seven of these 8 children could be followed up one to 21 years after the accident. All 7 children were free from complaints at the time of follow-up examination; in one case only we found a moderate loss of function in the injured hip joint. In this patient the x-ray film showed deformation of the head of the femur after partial necrosis of the femoral head, as well as initial signs of coxarthrosis. Prognosis of this rare injury in children is favourable if repositioning is performed in time and if relief of the hip is effected for the proper period of time, depending on the individual case.

Adolescent↗