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Biomedical subjects

F Weber

Publications and source records attributed to F Weber.

At least 19 recordsLinked to original sources
PubMed2001

Bunyamwera bunyavirus nonstructural protein NSs is a nonessential gene product that contributes to viral pathogenesis.

Bunyamwera virus (family Bunyaviridae, genus Bunyavirus) contains a tripartite negative-sense RNA genome. The smallest RNA segment, S, encodes the nucleocapsid protein N and a nonstructural protein, NSs, in overlapping reading frames. We have generated a mutant virus lacking NSs, called BUNdelNSs, by reverse genetics. Compared with the wild-type (wt) virus, BUNdelNSs exhibited a smaller plaque size and generated titers of virus approximately 1 log lower. In mammalian cells, the mutant expressed greatly increased levels of N protein; significantly, the marked inhibition of host cell protein synthesis shown by wt virus was considerably impaired by BUNdelNSs. When inoculated by the intracerebral route BUNdelNSs killed BALB/c mice with a slower time course than wt and exhibited a reduced cell-to-cell spread, and titers of virus in the brain were lower. In addition, the abrogation of NSs expression changed Bunyamwera virus from a noninducer to an inducer of an interferon-beta promoter. These results suggest that, although not essential for growth in tissue culture or in mice, the bunyavirus NSs protein has several functions in the virus life cycle and contributes to viral pathogenesis.

Aedes↗
PubMed1992

[Self measurement of blood pressure: automation and management problems].

In the Federal Republic of Germany, the introduction of clinical testing of devices designed for the self-measurement of blood pressure resulted in an improvement of quality of these devices during the last ten years. Further progress seems to be possible by more restrictive administrative prescriptions. Now, electronic devices have the same accuracy as stethoscope devices. They facilitate self-measurement especially in handicapped persons. Devices working by the oscillometric method do not measure blood pressure more accurately than Korotkow devices, but they are a bit less sensitive for wrong placing of the bladder. In most devices automation of the prescribed deflation rate (2 to 3 mmHg/s) was successful.

Blood Pressure Determination↗
PubMed1992

Endothelium-dependent relaxations are augmented in rats chronically treated with the angiotensin-converting enzyme inhibitor enalapril.

The study was designed to evaluate the effects of chronic inhibition of angiotensin-converting enzyme (ACE) on the reactivity of the endothelium and the smooth muscle to vasoconstrictor and vasodilator stimuli in normal rats. Male rats were treated orally for 6 weeks with enalapril (10 mg/kg/day, n = 10) or with placebo (n = 10). Endothelium-dependent relaxations to acetylcholine and adenosine diphosphate were augmented in aortic rings from rats treated with enalapril compared with controls, whereas the response to the endothelium-independent vasodilator SIN-1 were similar. Contractions induced by phenylephrine and angiotensin II remained unchanged. Thus, the results suggest that chronic ACE inhibition enhances the release of relaxing factors from the endothelium in normotensive rats.

Acetylcholine↗
PubMed1991

Noninvasive assessment of coarctation of the aorta: comparative measurements by two-dimensional echocardiography, magnetic resonance, and angiography.

Fifteen patients, aged between 9 and 21 years (mean, 15.1), with native coarctation of the aorta (CoA) or suspected recoarctation after surgical repair, underwent three different diagnostic procedures. Two-dimensional echocardiography (2D echo) and magnetic resonance imaging (MRI) of the thoracic aorta were performed in all patients; 14 patients underwent aortography, and digital subtraction angiography of the aorta was performed in one (after injection via a central venous catheter). Conventional electrocardiographic (ECG) gated MRI was performed, using the sagittal plane, a 256 x 256 acquisition matrix, multi-slice technique and a slice thickness of 10 mm. Diameters at the coarctation site were determined by all methods. Additional diameters of the descending aorta and the aortic arch were measured by MRI and echocardiography, respectively. All noninvasively obtained diameters were compared with angiographic data. Ultrasound imaging of the aortic isthmus was achieved in seven of 15 patients and of the aortic arch in nine of 15. The mean difference compared with angiographically determined diameters was 1.7 (0-7) mm, being greater for the coarctation site [mean, 2.2 (0-4)]. MRI images of the aortic isthmus were obtained in all patients, but the difference to angiographically determined diameters was slightly higher [mean, 3.2 mm (0-8)] than the ultrasound results. This deviation was presumably due to technical conditions, such as slice thickness and orthogonal imaging planes. Including all diameters, the correlation to invasive measurements was r = 0.82 (SEM = 3.1) for MRI and r = 0.89 (SEM = 2.3) for echo recordings.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Experimental allergic encephalomyelitis-prophylactic and therapeutic treatment with the cyclooxygenase inhibitor piroxicam (Feldene).

Prophylactic administration of Piroxicam (Feldene), a reversible inhibitor of prostaglandin biosynthesis, significantly reduced the occurrence of paralytic signs and the amount of antibodies against myelin basic protein in the model of mild acute experimental allergic encephalomyelitis in the Lewis rat. Mononuclear infiltration of the central nervous system remained unaffected. A therapeutic intervention with piroxicam, however, increased paresis and CNS pathology. Immunohistochemical studies revealed an increased proportion of ED1-positive macrophages and monocytes in the infiltrates of the spinal cord in animals treated with piroxicam. Possible reasons for the different effects of the prophylactic and therapeutic treatment are discussed in the study.

Administration, Oral↗
PubMed1991

Antihypertensive monotherapy with nitrendipine in general practice.

Efficacy and tolerability of antihypertensive monotherapy with the calcium antagonist nitrendipine were investigated in a 6-month open trial in 495 patients with mild to moderate essential hypertension from 101 practicing internists and general practitioners. Previous antihypertensive therapy (57.4%) was stopped for 1 week and therapy then started with nitrendipine, 20 mg once daily. Sixty-one patients discontinued therapy prematurely because of unwanted effects, mostly characteristic with dihydropyridines (headaches, flushing, and ankle edema), and 23 patients because of insufficient efficacy. In 75% of the remaining 411 patients, the goal blood pressure was achieved by nitrendipine monotherapy (10 mg in 17.6%, 20 mg in 73.3%, and 20 mg b.i.d. in 8%) and diastolic blood pressure was between 90 and 95 mm Hg in another 6%. The reduction in blood pressure did not result in changes of heart rate or weight. Nitrendipine was effective in patients of all age groups but patients older than 60 years of age showed a significantly greater fall in systolic pressure than middle-aged or young patients. At the end of the study, 15 patients still reported side effects. Nitrendipine appears to be well suited for first-line therapy of mild to moderate essential hypertension.

Adult↗
PubMed1991

[Intermediate results of kinematic knee prosthesis].

A retrospective study of 88 of 117 kinematic total knee prostheses was carried out at the Department of Orthopaedics, University Clinic, Innsbruck. In 71 cases the clinical and functional score of the knee Society was applied. Radiographs were taken under fluoroscopic control. In 3 cases, the need for revision surgery was already obvious. A slight varus angle of 2.1 degrees became apparent. Flexion contracture showed a correlation with the inclination of the femoral component. Radiolucencies of the tibial component showed up in cases with a reduced tibial angle. Radiolucencies of the patella component correlated with lateral subluxation.

Aged↗
PubMed1990

A potato mitochondrial isoleucine tRNA is coded for by a mitochondrial gene possessing a methionine anticodon.

The nucleotide sequence of a potato mitochondrial tRNA(Ile) has been determined. This tRNA has a lysidine-like minor nucleotide in the first position of the anticodon (position 34). The corresponding mitochondrial gene has been cloned and sequenced. This gene has a CAT anticodon which corresponds to methionine. The C residue in the anticodon must therefore be post-transcriptionally modified. The mature tRNA has isoleucine-accepting activity but no methionine-accepting activity. This is the first report showing that in plant mitochondria a post-transcriptional modification could change the amino-acid specificity of a tRNA, as compared to that of the corresponding gene.

Anticodon↗
PubMed1990

Transfer RNAs of potato (Solanum tuberosum) mitochondria have different genetic origins.

Total transfer RNAs were extracted from highly purified potato mitochondria. From quantitative measurements, the in vivo tRNA concentration in mitochondria was estimated to be in the range of 60 microM. Total potato mitochondrial tRNAs were fractionated by two-dimensional polyacrylamide gel electrophoresis. Thirty one individual tRNAs, which could read all sense codons, were identified by aminoacylation, sequencing or hybridization to specific oligonucleotides. The tRNA population that we have characterized comprises 15 typically mitochondrial, 5 'chloroplast-like' and 11 nuclear-encoded species. One tRNA(Ala), 2 tRNAs(Arg), 1 tRNA(Ile), 5 tRNAs(Leu) and 2 tRNAs(Thr) were shown to be coded for by nuclear DNA. A second, mitochondrial-encoded, tRNA(Ile) was also found. Five 'chloroplast-like' tRNAs, tRNA(Trp), tRNA(Asn), tRNA(His), tRNA(Ser)(GGA) and tRNA(Met)m, presumably transcribed from promiscuous chloroplast DNA sequences inserted in the mitochondrial genome, were identified, but, in contrast to wheat (1), potato mitochondria do not seem to contain 'chloroplast-like' tRNA(Cys) and tRNA(Phe). The two identified tRNAs(Val), as well as the tRNA(Gly), were found to be coded for by the mitochondrial genome, which again contrasts with the situation in wheat, where the mitochondrial genome apparently contains no tRNA(Val) or tRNA(Gly) gene (2).

Base Sequence↗
PubMed1990

Acromegaly and hypertension: prevalence and relationship to the renin-angiotensin-aldosterone system.

The prevalence of arterial hypertension was evaluated in a retrospective study of 158 patients with acromegaly, and results were compared to control populations, namely, the Munich Blood Pressure Study (MBPS) and the Framingham Study. The prevalence of hypertension (defined according to WHO criteria) was significantly increased in female patients but not in men; hypertensive acromegalics were older and tended to have higher body weight compared to normotensive patients. Hypertension was not related to serum concentrations of growth hormone. After successful treatment of acromegaly, growth hormone levels and systolic and diastolic blood pressure fell only in female hypertensive acromegalics; this did not occur in normotensives. The rise in plasma renin activity in response to upright posture was diminished in 57.9% of acromegalic patients. The prevalence of low-renin hypertension in our group of patients was 31.6%, which is similar to figures reported for unselected non-acromegalic subjects with essential hypertension. Orthostatic renin activity was weakly and inversely related (r = -0.3) to blood pressure. No relationship between plasma aldosterone concentration and blood pressure could be detected; however, in acromegalic women, aldosterone rose higher after ambulation than in men. In conclusion, hypertension is a common problem in acromegaly and at least in part related to similar risk factors in control populations. The association with abnormalities of the renin-angiotensin-aldosterone system is difficult to interpret and does not offer an explanation for the slight increase in the prevalence of hypertension.

Acromegaly↗
PubMed1990

Cross-reactivity of monoclonal antibody Leu-19 with some neuroectodermal and other non-immune tissues.

Leu-19 antigen is a 200-220 kDa surface glycoprotein, initially detected on natural killer (NK) cells exhibiting non-major histocompatibility complex-restricted cytotoxicity. Using a monoclonal antibody (mAb) directed against the Leu-19 molecule, we were unable to identify NK cells immunohistologically in cryostat sections of neuroectodermal tumors. Instead, mAb Leu-19 cross-reacted with the surfaces of the tumor cells, except for melanomas. It stained mesodermal tumor cells less intensely and did not stain those of carcinoma metastases. In three plasmacytomas, cells were observed, most likely NK cells, which extend Leu-19-positive cell processes towards to the unstained tumor cells. Furthermore, the Leu-19 antigen was identified on physiological tissues, especially on all neuroendocrine cells analyzed. The cross-reactions observed with Leu-19 mAb were confirmed using mAb NKH-1, which is also directed against the Leu-19 molecule. Thus, the expression of Leu-19 on neuroectodermal cells is another example of antigen sharing between specialized immune cells and the nervous system.

Adult↗
PubMed1990

[A clinical trial with a new silicone implant by Silikon Optik].

A new silicone IOL is described which was implanted in 57 eyes, in 50 cases following phacoemulsification through a 4.2-4.8 mm incision. The principal advantages of this IOL are (a) faster visual rehabilitation, because postoperative astigmatism is reduced and more stable, and (b) less glare and color alteration than after implantation of PMMA lenses. These optical advantages may be due to the non-occurrence of optic decentration, the absence of positioning holes, the biconvex optic, the fact that the surface is less reflective than that of PMMA, and the Tyndall effect of the lens material. The only disadvantage of this lens as compared to PMMA lenses is that the YAG laser is more likely to produce pitting or cracks during capsulotomy.

Adolescent↗