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Biomedical subjects

F Weber

Publications and source records attributed to F Weber.

At least 199 records · Page 11Linked to original sources
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↗
PubMed1990

[Value of a new simple mechanical large intestine preparation in comparison with PEG lavage].

UNLABELLED: The subjective incommodation of the patient by the well established methods of colonic cleansing for operation or endoscopic examination gave a reason to evaluate the efficacy of a new mechanical method in a prospective randomized study. 60 patients were divided in two groups: Colonic preparation was performed by YAL-irrigation in group 1, by oral lavage with PEG (polyethylene glycol electrolyte) in group 2. We found no fecal residue in 29.6% of the YAL group compared to 22.2% in the PEG group, a small amount of liquid stool in 29.6% (YAL) compared to 48.1% (PEG), a large amount of liquid stool in 25.9% of both groups and a solid stool in 14.8% (YAL) compared to 3.7% (PEG). The examination of the mucosal surface was hindered by solid or large amounts of liquid stool in 14.8% of group 1 and in 11.1% in the PEG group, particularly localized in the right hemicolon. In group 1, a significantly better valuation in subjective patient tolerance was found: 18.9% (YAL) compared to 77.8% (PEG) (p less than 0,0001) showed symptoms of patient discomfort. IN CONCLUSION: The simple mechanical preparation with YAL has been shown not to be as safe as with the PEG lavage. However, the YAL method seems to be a useful alternative in patients with suspected stenosis, tendency for vomiting as well as for examination or operation of the left hemicolon.

Colon↗
PubMed1990

[Detection of Leu-M1 immunoreactivity in brain tissue and brain tumors].

Immunohistochemical investigations were made of 170 tumours of the central nervous system, using anti-Leu-M1, with electron microscopy being used on 22 of them. At least focal Leu-M1 positive reactivity was established from 10 in 24 astrocytomas, four in 22 oligodendrogliomas, and 9 in 15 ependymomas. Unambiguous Leu-M1 positivity was recorded from 54% of Grade I gliomas and 20% of Grade II gliomas. Other malignant primary tumours of neuroepithelial origin as well as all meningiomas and neurinomas proved to be Leu-M1 negative. However, severe immunopositivity was exhibited in all cases by reactive cerebral tissue adjacent to tumours. Three of four carcinoma metastases were Leu-M1 positive. Investigations, using electron microscopy, have clearly shown that MMA positivity in reactive brain is associated primarily with extracellular space and with plasma membranes of gliocytes. No products of immune reaction were identified, on the other hand, not even ultrastructurally, from neoplastically dedifferentiated cells of anaplastic neuroepithelial tumours. This is likely to suggest that neoplastically transformed gliocytes are no longer capable of expressing lacto-N-fucopentose III. It has proved helpful in distinguishing between the benign and malignant nature of a tumour. More observations along those lines might contribute to more knowledge on dedifferentiation of gliocytes. Also, in electron microscopy, MMA positivity of carcinomas proved to be associated with glycocalyceal material.

Antigens, Differentiation, Myelomonocytic↗
PubMed1989

Changes in muscle blood flow after smoking a cigarette determined by a new noninvasive method.

In 9 healthy subjects the effect of smoking one cigarette (nicotine content 0.9 mg) on blood pressure, heart rate and total and muscle blood flow in the forearm was measured. Blood flow was measured by a new noninvasive plethysmographic method that simultaneously gives quantitative data about total and muscle blood flow. Smoking the cigarette did not significantly affect blood pressure or heart rate. Total blood flow in the forearm did not change but the flow to the muscle was increased and resistance in this vascular bed was decreased. The pattern of haemodynamic changes in the forearm indicates that epinephrine may be the mediator of the circulatory effects of nicotine.

Adult↗
PubMed1989

Vasodilation in the vascular bed of skeletal muscle after intravenous nifedipine in normotensives and hypertensives.

The aim of the study was to investigate the effect of nifedipine on blood flow and resistance in the forearm vascular bed of skeletal muscle in 10 male patients with primary hypertension and 10 age-matched male normotensives. We measured the effects of increasing doses of intravenous nifedipine on blood pressure, heart rate, total forearm blood flow and muscle blood flow. Muscle blood flow was determined by a combination of computed tomography and strain-gauge plethysmography. The nifedipine-induced increases in total forearm blood flow were the same in both groups. However, both the increase in muscle blood flow and the decrease in the resistance of the muscle vasculature were more pronounced in the hypertensives than in the normotensives (P less than 0.05). The data provide an explanation for the blood pressure reduction induced by nifedipine in hypertensives and support the hypothesis that elevated vascular resistance is an important functional component in primary hypertension.

Adult↗
PubMed1989

Protection against experimental allergic encephalomyelitis with complete Freund's adjuvant is unaffected by prostaglandin synthesis inhibition.

Pretreatment with complete Freund's adjuvant blended with aluminium hydroxide (ALU-CFA) prevents the clinical as well as histological manifestation of experimental allergic encephalomyelitis (EAE) in Lewis rats. Suppression of prostaglandin biosynthesis with the cyclooxygenase inhibitor piroxicam (10 mg/kg body weight) from day 2 before to day 17 after EAE induction could not restore responsiveness in pretreated animals. In contrast piroxicam increased ALU-CFA-induced suppression of autoantibodies against myelin basic protein. In controls not pretreated with ALU-CFA, clinical signs of EAE were attenuated by piroxicam, whereas mononuclear infiltration of the brain remained unchanged. Therefore it is unlikely that prostaglandins exert an important function in the regulation of immune responses in this model of autoimmunity.

Adjuvants, Immunologic↗
PubMed1989

Treatment of benign gastric ulcer: a comparative clinical trial of rioprostil and ranitidine.

This study is a multicentre, double-blind, double-dummy, two-way, parallel group comparison of the efficacy and safety of rioprostil and ranitidine in the treatment of active gastric ulcer. Ninety-one patients with gastric ulcer are randomly allocated to treatment with either rioprostil 300 micrograms b.d., or ranitidine, 150 mg b.d. The duration of treatment is 4 weeks, or 8 weeks for the patients who are improved but not healed at 4 weeks. Clinical, endoscopic and laboratory assessments are made before treatment, and after each treatment period. Therapeutic success is defined as complete endoscopic healing of the ulcer. At the end of the treatment period, either 4 or 8 weeks, healing rates are 69% in the rioprostil group, and 66% in the ranitidine group; this difference is not significant (p = 0.86). After the first 4 weeks of treatment the healing rates are 44% and 55% in the rioprostil and ranitidine groups, respectively. The incidence of adverse effects is 22% in the rioprostil group, and 7% in the ranitidine group (p = 0.036). Diarrhoea is the most common side effect (12%), but is usually intermittent and mild. We conclude that rioprostil, 300 micrograms b.d., for up to 8 weeks is as effective as ranitidine, 150 mg b.d., in the treatment of benign gastric ulcer.

Adult↗
PubMed1989

[The concept of developmentally-induced structural ego disorders--a reference frame for working with extremely borderline patients?].

The concept of developmental-structural ego defects provides a therapeutic framework for the treatment of patients who have, in the past, largely been classified as untreatable. With emphasis on individual therapeutic treatment, this paper provides a critical introduction to the concept and discusses the applicability of this therapeutic approach for extremely lower-lower class patients: patients doubly stigmatized by psychological illness and criminality who are treated in a forensic-psychiatric clinic.

Antisocial Personality Disorder↗