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Biomedical subjects

J Kramer

Publications and source records attributed to J Kramer.

At least 55 records · Page 3Linked to original sources
PubMed1990

[CT and MRT in mediastinal and hilar space-occupying lesions].

Thirty-eight patients with mediastinal and/or hilar masses were imaged by computed tomography (CT) and magnetic resonance imaging (MRI). Results were analyzed retrospectively regarding the ability to demonstrate the masses, their number, size, definition, location and tissue characteristics. CT and MRI showed equivalent results in 32 cases; additional information was obtained in two patients by CT, in four patients by MRI. In view of the specific advantages and limitations of both CT and MRI we believed that in patients with mediastinal and/or hilar masses, contrast enhanced CT remains the procedure of choice after performing plain chest radiographs; in certain cases MRI will prove useful for further evaluation.

Adolescent↗
PubMed1989

Low incidence of null alleles of the fourth component of complement (C4) in elderly people.

Allotype frequencies of three complement proteins (C2, factor B, and C4) encoded on the sixth chromosome were tested in 150 "young" (under 53 yrs) and 131 "old" (over 62 yrs) healthy Hungarian individuals. In women, we found significant differences in BF*F allotype frequencies between the two age groups. A marked decrease of null alleles for C4 was observed especially in men. In the "old" age group, the total frequency of the non-expressed, "null" (Q0) alleles of the C4 protein dropped to almost one third of the "young" ones. The decrease was even larger (a 5.5-fold decrease in the incidence) among men. The relative risk of those having C4B*Q0 allele not to survive a "critical age period" of 53-62 yrs for males and 58-62 yrs for females was calculated to be 12.4 and 2.85, respectively. Our data substantiate the view that the expected life time is genetically determined and it can be forecast partly by the analysis of the antigens encoded on the sixth chromosome.

Adult↗
PubMed1989

Late effects of cancer therapy on the central nervous system.

The number of studies documenting the long-term morbidity of CNS treatment has increased dramatically in recent years. Cranial irradiation, in particular, has been associated with cognitive deficits and neuroanatomic pathology. Children who are treated at an early age and individuals who receive higher doses (2,400 cGy or greater) appear to be at greatest risk for these sequelae. Much more research on the pathogenesis of delayed injury following CNS treatment is needed. Although several compelling mechanisms have been proposed, little empirical evidence is available. This knowledge is essential to the identification of agents that may protect normal brain tissue from injury. Even less is known about the effects of age at time of treatment, type of treatment (radiation v chemotherapy), or dose of radiation in relation to delayed injury. Of utmost importance are studies that will establish the predictive relationship between brain injury and cognitive deficits. This would allow clinicians to predict patients who are at risk for cognitive impairment in order to institute appropriate preventive or remedial interventions.

Adult↗
PubMed1989

[Duplex sonography after femoro-distal vascular reconstruction using umbilical veins].

In 34 patients femoro-distal reconstructions with umbilical vein grafts were assessed by means of pulsed Duplex sonography. Dilatations of the grafts and aneurysms were diagnosed easily by means of DS, likewise thrombotic plaques and perivascular pathologies. Haemodynamically significant stenoses can be quantified due to the increased velocity measured by pulsed Doppler. It can be concluded that DS is the method of choice for the postoperative follow-up of umbilical vein grafts of the femoro-distal vascular system.

Aged↗
PubMed1989

[Fibrous dysplasia: its appearance in the magnetic resonance tomogram].

Eleven patients with proven fibrous dysplasia of the skeleton (FD) were examined using magnetic resonance imaging (MRI). Almost constantly T1-weighted hypointense, T2-weighted hyperintense (cystic) as well as T1- and T2-weighted hypointense (fibrous) areas within the lesion could be demonstrated, the latter of which always exhibited either moderate or marked enhancement following intravenous application of Gd-DTPA, resulting in a typical appearance. Furthermore, T1- and T2-weighted hyperintense areas within the lesion were seen in many patients due to focal hemorrhage. No linear time correlation between the clinical symptom pain and focal areas of hemorrhage as shown by MRI, could be established.

Adult↗
PubMed1989

SSC1, an essential member of the yeast HSP70 multigene family, encodes a mitochondrial protein.

SSC1 is an essential member of the yeast HSP70 multigene family (E. Craig, J. Kramer, and J. Kosic-Smithers, Proc. Natl. Acad. Sci. USA 84:4156-4160, 1987). Analysis of the SSC1 DNA sequence revealed that it could encode a 70,627-dalton protein that is more similar to DnaK, an Escherichia coli hsp70 protein, than other yeast hsp70s whose sequences have been determined. Ssc1p was found to have an amino-terminal extension of 28 amino acids, in comparison with either Ssa1p, another hsp70 yeast protein, or Dnak. This putative leader is rich in basic and hydroxyl amino acids, characteristic of many mitochondrial leader sequences. Ssc1p that was synthesized in vitro could be imported into mitochondria and was cleaved in the process. The imported protein comigrated with an abundant mitochondrial protein that reacted with hsp70-specific antibodies. We conclude that Ssc1p is a mitochondrial protein and that hsp70 proteins perform functions in many compartments of the cell.

Amino Acid Sequence↗
PubMed1989

Invasive pulmonary aspergillosis: evaluation with MR imaging.

Eleven patients with suspected invasive pulmonary aspergillosis underwent magnetic resonance (MR) imaging. Images were obtained with standard spin-echo sequences and electrocardiographic triggering before and after intravenous administration of gadolinium diethylenetriaminepentaacetic acid. Thirty-seven of 48 lesions seen on MR images were nodular infiltrates; 34 of these had a targetlike appearance, with hypointense centers and iso- or hyperintense rims. Twenty-three of 37 nodular lesions contained areas of hyperintensity on T1-weighted images. All 37 had enhanced rims on postcontrast MR images. The remaining 11 lesions were segmental infiltrates, seven of which were predominantly hyperintense on T1-weighted images. In one patient with nodular lesions, MR imaging findings were correlated with those from pathologic analysis of a resected upper lobe. Areas of hyperintensity corresponded to subacute hemorrhage permeated by Aspergillus organisms. The authors believe that the typical targetlike appearance of nodular lesions on MR images and the potential that MR imaging has to reveal hemorrhagic content will prove useful in the early diagnosis of invasive pulmonary aspergillosis.

Aspergillosis↗
PubMed1989

Unequal expression of complement C4A and C4B genes in rheumatoid synovial cells, human monocytoid and hepatoma-derived cell lines.

C4A and C4B are closely related homologous complement proteins encoded in the class III region of major histocompatibility complex (MHC). The regulation of their expression is under genetic and hormonal control. In this study we investigated the synovial fluid plasma ratio of C4A and C4B of rheumatoid (RA) and osteoarthritis (OA) patients, and a predominance of the C4B gene expression by the synovial macrophages of RA patients was demonstrated. To clarify the tissue specificity of the expression of C4A and C4B genes, human monocytoid cell line U937 and hepatoma-derived HepG2 cells were studied. The gene expression of C4A and C4B were markedly different in these cells since a relative predominance of C4B mRNA in U937 cells and excess of that of C4A in HepG2 cells were detected. Recombinant interferon-gamma (IFN-gamma) up-regulated the expression of C4A gene in both cells, but had apparently no effect on the C4B gene. Our results demonstrate dissimilar expression patterns for the two human C4 genes, suggesting different tissue specific regulation of human C4A and C4B.

Anaphylatoxins↗
PubMed1989

[Gadolinium-DTPA in magnetic resonance tomography. Clinical use--indications].

Magnetic resonance tomography was performed on 158 patients with different indications before and after the administration of contrast medium. The MR examination included various plain T1 and T2 weighted spin echo sequences as well as T1 weighted examinations after intravenous application of Gadolinium-DTPA ("Magnevist", Schering AG) in a dosage of 0.1 mmol/kg body weight. The following conclusions were drawn: The sensitivity of MR in detecting brain tumors, acoustic neuromas and pituitary adenomas was improved considerably after the administration of "Magnevist". To diagnose the type of tumor, the criteria which apply to Gd-DTPA are similar to those used for iodine-containing contrast medium in CT. In about 2/3rds of the cases, delineation of pathological tissues from surrounding edema and normal structures was better than in plain films. Hence, accurate, pretherapeutic staging of bronchial carcinomas and an exact definition of the expansion of the malignancies in the muscle-skeleton system were possible. In respect of tumors in the region of the base of the skull, we could omit T2-weighted sequences without noticeable loss of diagnostically relevant information; the examination time could thus be shortened by about 12 minutes.

Adolescent↗
PubMed1989

Internal carotid artery aneurysm: a vascular manifestation of type IV Ehlers-Danlos syndrome.

Aneurysms of the distal internal carotid artery (ICA) can be difficult to manage. When seen in a patient with Ehlers-Danlos Syndrome, type IV (EDS-Type IV), the complexity of the problem is greatly increased. Proximal ICA ligation in the presence of an intact circle of Willis and adequate collateral circulation is a reasonable and safe approach. We recommend the liberal use of duplex scanning and intravenous digital angiography in patients with EDS, and plan to use these techniques to follow the small, asymptomatic, right ICA aneurysm in our patient. If the aneurysm rapidly grows or becomes symptomatic, treatment may require proximal ligation with extracranial-intracranial bypass. Understanding of the basic defects associated with EDS-Type IV will make the management of patients with vascular complications more safe.

Adult↗
PubMed1989

Rapid determination of the human complement factor B phenotypes.

A rapid phenotyping method for human complement factor B (Bf) was worked out using high voltage acetate electrophoresis. The results were compared with those obtained by conventional agarose gel electrophoresis. Separation of the bands was performed in the same way, but only 2.5 hours were required for the evaluation of 24 samples. Furthermore, at least ten times less specific antibody was needed than for the conventional technique.

Complement Factor B↗
PubMed1989

[Intratemporal course of the facial nerve in magnetic resonance imaging].

MR images of the intratemporal portion of the facial nerve were obtained with a 1.5 Tesla permanent magnet whole-body imaging system. The facial nerve was followed from the internal auditory through the temporal bone to the styloid foramen. MR promises to be a sensitive method for the evaluation of intratemporal facial nerve diseases.

Facial Nerve↗
PubMed1988

Pediatric AIDS. Neuroradiologic and neurodevelopmental findings.

A group of 23 pediatric patients seropositive for HIV antibody were studied by computed tomography and evaluated neurodevelopmentally. Significant neurodevelopmental delays were found in over 95% of the patients studied. CT findings in six patients were normal and thirteen of 23 (57%) had prominence of the CSF spaces. Less frequent findings included calcifications in the basal ganglia and white matter. Cerebral mass lesions included one case of lymphoma and one case of hemorrhage. The CT findings in the pediatric age group differs from the adult population in that contrast enhancing inflammatory mass lesions are uncommon.

AIDS-Related Complex↗
PubMed1988

Enzyme activity and behavior in hyperactive children grown up.

Thirty-one men, originally seen as children for problems with overactivity, distractibility, and impulsiveness, were reevaluated at ages 21-23 years. Subjects were interviewed and tested and provided a blood sample for analyses of dopamine-beta-hydroxylase (DBH), monoamine oxidase (MAO), and catechol-O-methyl-transferase (COMT). A series of Pearson correlations between the biological variables and psychological measures revealed that MAO levels were negatively associated with measures of drug involvement, cigarette use, fire-setting, and sensation seeking; DBH levels were positively associated with measures of sensation-seeking; and COMT levels were negatively associated with a measure of hostility and positively correlated with a measure of impulsiveness.

Adult↗
PubMed1988

Serum Lp(a) level as a predictor of vein graft stenosis after coronary artery bypass surgery in patients.

Although the serum lipoprotein fraction Lp(a) has been associated with coronary artery atherosclerosis, its relationship to narrowing of saphenous vein grafts has not previously been elucidated. We therefore measured serum Lp(a) levels in 167 symptomatic patients undergoing cardiac catheterization who had had coronary artery bypass surgery 0.7 to 14.3 years earlier. Lp(a), total cholesterol, and total triglyceride levels were compared with the degree of saphenous vein graft stenosis to test for any association. Serum Lp(a) levels were significantly associated with the degree of stenosis of saphenous vein grafts (r = .24, p = .002). Mean Lp(a) levels (mg/dl) in the 135 patients with stenosis were almost double (32.0 +/- 32.7, mean +/- SD) those in the 32 patients with no graft stenosis (16.7 +/- 22.6; p = .002). Graft stenosis was not associated with previous myocardial infarction, hypertension, obesity, diabetes, or smoking. Serum cholesterol levels (mg/dl) were slightly higher in the stenosis group (251.3 +/- 69) than in the no-stenosis group (231.8 +/- 48.8), but the difference was of borderline significance (p = .06). A stepwise increase in mean Lp(a) was found in groups of patients with increasing vein graft stenosis. At a serum Lp(a) level of 31.6 mg/dl or above, 92% of the patients demonstrated vein graft stenosis. Thus, patients with elevated Lp(a) levels have an increased risk of developing saphenous vein graft stenosis after coronary bypass surgery.

Cardiac Catheterization↗