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J Schmidt

Publications and source records attributed to J Schmidt.

At least 505 records · Page 28Linked to original sources
PubMed1992

Generation and possible significance of trypsinogen activation peptides in experimental acute pancreatitis in the rat.

Trypsinogen activation peptides (TAP) were quantified by radioimmunoassay in blood, urine, and peritoneal exudate of rats with experimental pancreatitis. Forty-four animals were studied, comprising a control group and four different induction techniques (cerulein, cerulein plus either 2- or 10-min intraductal glycodeoxycholic acid [GDOC] infusion, and cerulein plus intraductal GDOC with enterokinase [EK]). Significantly higher TAP concentrations were found at 6 h (or at death) in plasma and ascites of all pancreatitis groups compared with controls. TAP quantitation in hourly urine samples demonstrated significantly higher concentrations from the third hour onward in the most severe groups and from the fourth hour onward in the cerulein-treated rats. All nonsurviving rats had a plasma TAP of greater than 2.5 nM/L, whereas only 1 of 34 surviving animals had such a concentration (p less than 0.001). A significant stepwise increase in total TAP in ascites was found when comparing the cerulein group, the two GDOC groups, and the EK group (p less than 0.001). Chromatography of samples with a high TAP content demonstrated comigration with synthetic TAP. We conclude that free TAP are present in blood, urine, and peritoneal exudate of rats with experimental pancreatitis of different pathogenesis and that the amount of TAP may be indicative of the severity of the disease process.

Acute Disease↗
PubMed1992

Retrovirus-like particles from the human T47D cell line are related to mouse mammary tumour virus and are of human endogenous origin.

Retrovirus-like particles were secreted in a steroid-dependent manner by the human mammary carcinoma cell line T47D. The particles exhibited typical retroviral properties such as their electron microscopic appearance (95 nm in diameter) and occasional budding, sedimentation at 1.14 g/ml, reverse transcriptase activity and genomic RNA. The T47D particles were related to mouse mammary tumour virus (MMTV) as shown by their ultrastructural appearance (B type-like eccentric dense cores and budding), Mg2+ dependence of the reverse transcriptase activity; immunological reactivity with MMTV-directed antibodies (revealing proteins of 63K, 52K, 26K and 18K), and hybridization of particle RNA with MMTV DNA under stringent conditions. Purified particles were able to incorporate deoxynucleoside triphosphates in the absence of an exogenous primer and template, thus indicating the existence of a complete and biochemically functional reverse transcription apparatus (reverse transcriptase, RNA and primer) and the ability to direct endogenous cDNA synthesis. Labelled particle cDNA hybridized strongly to human genomic DNA but not to mouse and cat DNA, thus indicating the human origin of the T47D particles. Furthermore all human DNAs, hybridized with the labelled particle cDNA, showed a uniform hybridization pattern of restriction fragments, indicating the endogenous origin and distribution of the proviral particle DNA in the human genome.

Adenocarcinoma↗
PubMed1992

Influence of hypertonic-hyperoncotic solution and furosemide on canine hydrostatic pulmonary oedema resorption.

1. This study aimed at enhancing the clearance of experimental hydrostatic pulmonary oedema in dogs using hypertonic-hyperoncotic solution (HHS) and furosemide. 2. Anaesthetized dogs (n = 20) were mechanically ventilated with a positive end-expiratory pressure of 10 cmH2O (1.0 kPa). 3. Hydrostatic pulmonary oedema was induced by inflating a balloon inserted into the left atrium and simultaneously infusing isotonic saline rapidly. Oedema formation was terminated by deflating the balloon and reducing the infusion rate. 4. Four groups were studied: A, control; B, furosemide; C, HHS and D, HHS+furosemide. HHS, 6 ml kg-1, was given as a bolus injection and furosemide, 1 mg kg-1, intravenously as a bolus followed by an infusion of 0.5 mg kg-1 h-1. All dogs were studied for 4 h. 5. Serum osmolarity, plasma colloid oncotic pressure and diuresis in groups C and D (HHS groups) substantially increased; haemoglobin concentration decreased and pulmonary arterial wedge pressure remained constant. 6. Despite the combination of these factors favouring fluid flux from the extravascular to the intravascular compartment, extravascular lung water measured with the double indicator dilution technique decreased no faster in the HHS groups than in the two other groups (from over 26 to approximately 19 ml kg-1 in groups A, C and D and to 14.7 in group B (only furosemide)). 7. This was confirmed by postmortem gravimetric measurements of extravascular lung water; A, 11.0 +/- 5.7; B, 9.7 +/- 3.3; C, 10.5 +/- 3.1 and D, 10.6 +/- 1.8 g kg-1. 8. We speculate that mechanisms other than effective Starling gradients and enhanced diuresis might define a maximal rate of pulmonary oedema clearance.

Animals↗
PubMed1992

Molecular cloning of osteoma-inducing replication-competent murine leukemia viruses from the RFB osteoma virus stock.

We report the molecular cloning of two replication-competent osteoma-inducing murine leukemia viruses from the RFB osteoma virus stock (M. P. Finkel, C. A. Reilly, Jr., B. O. Biskis, and I. L. Greco, p. 353-366, in C. H. G. Price and F. G. M. Ross, ed., Bone--Certain Aspects of Neoplasia, 1973). Like the original RFB osteoma virus stock, viruses derived from the molecular RFB clones induced multiple osteomas in mice of the CBA/Ca strain. The cloned RFB viruses were indistinguishable by restriction enzyme analysis and by nucleotide sequence analysis of their long-terminal-repeat regions and showed close relatedness to the Akv murine leukemia virus.

Animals↗
PubMed1992

Biochemical and morphological changes in rat lenses after long-term UV B irradiation.

The aim of the present study was to investigate biochemical and morphological changes in rat lenses following long-term UV B irradiation. After an irradiation period of 156 days with follow-up documentation by means of Scheimpflug photography, section-related biochemical analyses of the lenses as well as histological investigations were performed. The video-based Scheimpflug photography (Zeiss SLC) again proved to be an excellent method for the documentation of the UV cataract induced in rats. The biochemical analyses provided indications to potential damaging mechanisms; the section-related technique used allows more precise analyses than the processing of whole lenses in a cataract type restricted to a certain layer, as is the case with UV B damage. The most prominent biochemical findings were a significant decrease in glyceraldehyde-3-phosphate dehydrogenase in the equatorial region in the group with the highest irradiation dosage and a decrease in lactate dehydrogenase in the nuclear region. The histological results reflect the local extent of the UV damage as well as its progression after a prolonged irradiation period.

Animals↗
PubMed1992

Evidence that acetylcholine is an inhibitory transmitter of heart interneurons in the leech.

1. In the leech, synaptic transmission between heart interneurons (HN cells) and between HN cells and heart motor neurons (HE cells) is blocked by bicuculline methiodide. 2. Gamma-aminobutyric acid, when applied focally onto the somata of HN cells or when added to the superfusate, has no effect on the membrane potential of HN cells. 3. Both acetylcholine (ACh) and the ACh agonist carbachol hyperpolarize HN cells and HE cells when applied focally onto their somata or into the neuropil or when added to the superfusate. 4. Inhibitory postsynaptic-potential-like responses elicited by focal application of carbachol onto the somata of HN cells and HE cells are blocked by bicuculline methiodide and are reversed when Cl- is injected into the cells. 5. Focal application of carbachol onto the somata of HN cells and HE cells increases membrane conductance. 6. The results indicate that HN cells use ACh as an inhibitory transmitter, that the postsynaptic receptors for ACh are blocked by bicuculline methiodide and that inhibition of HN cells and HE cells is mediated by an increased Cl- conductance.

Acetylcholine↗
PubMed1992

Characterization of platelet-activating factor induced superoxide anion generation by guinea-pig alveolar macrophages.

Guinea-pig alveolar macrophages (AM) exhibited a concentration dependent superoxide anion (.O2-) generation as measured by means of lucigenin-chemiluminescence (CL) in response to platelet-activating factor (PAF) in the range of 1 nM to 100 nM. PAF effects on .O2(-)-generation were specific to the form of PAF that is biologically active in most systems; lyso-PAF had no effect. The CL-response was inhibited following incubation with EDTA (IC50: 859 microM), the intracellular Ca(2+)-antagonist TMB-8 (IC50: 73 microM), or the calmodulin antagonists W-7 (IC50: 13 microM) and trifluoperazine (IC50: 14 microM) indicating the involvement of Ca2+ in the signal transduction pathway. Increasing the intracellular cAMP-levels by PGE2 or forskolin resulted in an inhibition of the CL-response, whereas the beta-adrenoceptor agonist salbutamol showed no effect. On the other hand phosphodiesterase inhibition by IBMX (10 microM: 25%) or zardaverine (10 microM: 29%) also resulted in a transient inhibition of the CL-response. Protein kinase C (PKC) seemed not to be involved in the signal transduction, since the PKC-inhibitors staurosporine, H-7 and D-sphingosine were inactive. In contrast, the PAF receptor antagonists WEB-2086 (IC50: 700 nM) and WEB-2170 (IC50: 176 nM) exerted a strong inhibitory activity. The antiallergic/antiasthmatic drug azelastine also reduced the PAF induced CL-response (IC50: 12 microM), whereas the other antiallergic/antiasthmatic compounds showed almost no inhibition.

Animals↗
PubMed1992

Morphological cephalometric differences between two European populations.

Earlier research in craniofacial morphology of the inhabitants of Mainz (Germany) and Zagreb (Croatia), who represent the populations of wider areas, have shown some roentgen-cephalometric differences. The aim of this study is to determine the craniofacial morphologic differences of these populations in three dimensions. The sample consists of 200 adult examinees, male and female respectively, inhabiting the mentioned areas. The sample has been chosen so that the examinees with prominent craniofacial anomalies have been excluded. Twenty three craniofacial parameters with the usual anthropometric instruments have been measured. The data have been processed by using elementary descriptive statistics and discriminant analysis. The results have shown that in Mainz examinees longer and narrower heads and higher faces in comparison with Zagreb examinees, predominate. Significant differences in forehead widths and bipupilar distances have been found.

Adolescent↗
PubMed1992

Skeletal muscle grids for assessing current distributions from defibrillation shocks.

This paper utilizes a structured and an unstructured grid representation of a torso with an anisotropic skeletal muscle to assess current distributions from defibrillation shocks. The results show that a finite-element solution on an unstructured grid of 400,000 elements (60,000 nodes) achieves comparable current distributions with a finite-difference solution on a structured grid that uses approximately the same number of nodes. Moreover, a finite-element solution on a 65,000-element (10,500 nodes) unstructured grid yielded fractional percent current results within 5% of the finer grids. The structured and unstructured grid models are used to investigate recent interpretations of experimental data that concluded that more than 80% of the total defibrillation current is shunted by the anisotropic skeletal muscle thoracic cage. It is concluded that these interpretations, which were based on a one-dimensional resistive network representation of the three-dimensional defibrillation situation, overestimate by 25% the current shunted by the anisotropic thoracic cage.

Animals↗
PubMed1992

Calculation of 3-D deformity in scoliosis by standard roentgenograms.

The standard radiological diagnosis of advanced scoliosis consists of roentgenograms of the total spine in anterior-posterior and lateral views. The deformity of the spine is measured by using the Cobb angle, thus only giving the projected angle of deformity, without showing the true 3-dimensional aspect. The 3-D calculation of the deformity is relevant to diagnosis and therapy of scoliosis. In this paper we define angles according to the Cobb definition, evaluate them trigonometrically and show them in two tables. These angles allow the 3-dimensional deformity in scoliosis to be calculated using the standard roentgenograms in two perpendicular views. This procedure enables us to avoid techniques costly in time and effort in hospital routine, such as stereo radiography, computer-analysis or 3-dimensional reconstruction of CT- and MRI-investigations.

Biometry↗
PubMed1992

Histological investigation for comparison of cartilaginous tumors of unknown biological course with unequivocal chondrosarcomas.

Morphological findings recorded from chondromatous tumors of unknown biological behaviour (n = 40) were compared with those obtained from unequivocal chondrosarcomas (n = 27), and the histological results were evaluated by clinical outcome. The morphological details were analysed by histological set up and summarized by Mirra et al. (1985): Two benign patterns, the enchondroma encasement pattern and the island of cartilage patterns, were the most common findings in cartilaginous tumors of unknown biological behaviour. Malignant patterns, such as chondrosarcoma permeation, invasion of the Haversian system, soft tissue mass and bands of fibrosis patterns were detected only in unequivocal chondrosarcomas. However, the enchondroma encasement pattern could be focally demonstrated also in central chondrosarcomas (n = 3), a phenomenon, which in our opinion could not be interpreted as being indicative of a preexisting benign lesion. Morphological classification of chondromatous tumors of unknown biological behaviour, as a group of benign cartilaginous tumors, enables their discrimination from unequivocal chondrosarcomas. This was also confirmed by the significant difference (p = 0.0065; Mantel-Cox) among survival curves after Kaplan and Meier (1958). We conclude that the above criteria, when applied with due caution, are helpful in classifying chondromatous tumors.

Bone Neoplasms↗
PubMed1992

[Possibilities in clinical quality assurance founded on a basis documentation system and extended evaluation studies].

Although the topic of quality control (QC) has been under discussion at least since the "Health Reform Legislation" (GRG) in almost all areas of the public health system, there is quite often a lack of models for practicability. Even for inpatient medical rehabilitation--at least concerning empirically founded QC-measures suitable methods and instruments have still to be developed. These must be relatively simple and economical to be integrated in the daily routine within a special clinic, if quality control should function. Starting from a broad concept of evaluation, the authors present a practical empirical QC-model for clinics, specifically for psychosomatic rehabilitation, which has been developed and proven for more than five years. To investigate the "programme" of the clinic, or particular program components (e.g. patients, treatments, outcome criteria) with systematically obtained data and analysis, is the main goal of this model. Where statements are replaced by empirically proven data. Aspects of process and outcome quality are considered to be a main task, and transparency is a necessary supposition. This model is particularly based on questionnaire procedures, is two-tracked, e.g. it is composed by continuous data collection ("treatment documentation") on the one hand and by time-restricted and defined studies for programme evaluation on the other. The treatment results represent the true target variable.

Documentation↗
PubMed1992

Clamydial antibody in sera of patients with trachoma.

Serum samples were taken in 1987 from 118 patients with trachoma seen in the Department of Opthalmology of the Gonder College of Medical Sciences, Gonder, Ethiopia, patients being staged according to MacCallan (II, III, IV), and classified in categories of different degrees of inflammation according to Dawson et al. Sera were investigated with the microIF test, using Chlamydia trachomatis serotypes A, B, C and partially D as antigens. Healthy Ethiopian students (n = 14), patients with chlamydial urogenital infections (n = 100), salpingitis (n = 47), and D-seronegative individuals (n = 574) served as controls. Patients with trachoma with severe inflammation showed significantly higher chlamydial antibody titres (greater than or equal to 1:128) against serotype A (p less than 0.05), B (p less than 0.01), and C (p less than 0.01) than patients with trivial, mild or moderate inflammatory symptoms. There was little correlation between MacCallan stages and chlamydial antibody titres, probably due to persistence of antibodies. In the control group of Ethiopian students only single persons were found to react with C. trachomatis serotypes A, B, and C in high titres; the geometric mean varied from x = 1:17 to x = 1:25 and distinctly differed from trachoma patients (x = 1:65). The individuals of other control groups showed high antibody titres against serotype C only in single cases and low geometric mean values.

Adolescent↗
PubMed1992

Metastatic growth of v-fos-induced osteosarcoma, following in vitro cultivation.

A tumour cell line was established from a non-metastatic osteosarcoma which had developed in the right femur after infection of a newborn mouse with FBR osteosarcoma virus (FBR MSV). After 20 cell culture passages and injection of the cells into newborn syngeneic mice, the animals developed fibrosarcomas on the site of injection. Metastatic lung tumours were detected in 50% of the mice. Metastatic tumour growth was preferentially observed in the walls of large blood vessels and in subpleural zones. Large areas of the metastatic tumours resembled mature connective tissue. This model of in vitro progression from a primary non-metastasizing osteosarcoma to a neoplasm with particular metastatic potency, though with a growth pattern similar to fibromatosis may serve as a useful system to study the different steps of metastatic progression, distinct tropism of invasive cells and fibrous maturation of metastatic tumours.

Animals↗
PubMed1992

[Vaccinations].

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Bacterial Vaccines↗
PubMed1991

Separation of o-phthalaldehyde-mercaptoethanol derivatives of amino acids from blood plasma on reversed-phase Nova-Pak C18 cartridges.

A separation of 25 o-phthalaldehyde-mercaptoethanol derivatives of primary amino acids in plasma prepared from human blood has been developed for Waters 10 cm x 0.8 cm I.D., 4-microns Nova-Pak C18 Radial-Pak cartridges. A binary gradient system with solvent-switching capability for the A pump is required. Computer methodologies have been utilized to develop mobile phase mixtures of phosphate buffer (pH 6.9), water, methanol and tetrahydrofuran. Advantages of the method include simple sample preparation, fast turnover time (67 min including the pre-column Autotag derivatization procedure) and exceptional column durability (several hundred analyses).

Amino Acids↗