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Biomedical subjects

F Huber

Publications and source records attributed to F Huber.

At least 19 recordsLinked to original sources
PubMed1992

Regulation of inositol 1,4,5-trisphosphate metabolism by guanine nucleotides in membranes of cultured newborn rat cardiomyocytes.

Membranes of cultured newborn rat cardiomyocytes contain enzymatic activities that regulate the formation and the breakdown of inositol 1,4,5-trisphosphate (1,4,5-IP3). GTP gamma S increased the rate of exogenous [3H]phosphatidyl 4,5-bisphosphate ([3H]PIP2) hydrolysis (EC50: 40 microM). This effect was dependent on the presence of deoxycholate and maximal at 2 mM deoxycholate. GTP gamma S increased the efficacy of phospholipase C (PLC) (by 2.3-fold), but did not alter the apparent affinity of the enzyme for PIP2. Other nucleotides, GDP beta S and ATP gamma S, and pyrophosphate also stimulated PIP2 hydrolysis, while AlF4- was ineffective. The effect of GTP gamma S was not inhibited by GDP beta S. The agonists norepinephrine and thrombin, which by themselves had no effect, did not potentiate the response to GTP gamma S. In contrast, 1,4,5-IP3 hydrolysis was decreased by GTP gamma S (EC50: 100 microM) as well as by other nucleotides and by pyrophosphate, but not by AlF4-. GDP beta S did not antagonize the GTP gamma S-induced inhibition of IP3 hydrolysis. These results suggest that GTP can stimulate the hydrolysis of exogenous PIP2 by an action on membrane-bound PLC at a site beyond the G protein activating PLC and inhibit the hydrolysis of 1,4,5-IP3 by a mechanism common to all nucleotides. Thus, GTP can regulate 1,4,5-IP3 metabolism by stimulating its formation and inhibiting its breakdown.

Adenosine Triphosphate↗
PubMed1992

Efficacy of once-a-day intranasal administration of triamcinolone acetonide in patients with seasonal allergic rhinitis.

A 4-week, double-blind, parallel group study compared the safety and efficacy of once-a-day intranasal administration of triamcinolone acetonide (Nasacort) versus placebo in 304 patients (155 adult and 149 adolescent) with seasonal allergic rhinitis. Patients were randomized to receive triamcinolone acetonide (110, 220, or 440 microgram) or placebo once daily each morning. Daily rhinitis symptoms scores, weekly patient and physician global assessments, and weekly nasal eosinophil smears were obtained. In each triamcinolone acetonide group, significant (P less than .05) improvement over placebo was noted in the nasal index (sum of ratings for stuffiness, discharge, and sneezing) by week 1, the first point of analysis, and maintained throughout the study. Triamcinolone acetonide groups also demonstrated significant (P less than .05) improvement over placebo in all individual rhinitis symptoms evaluated. The greatest improvement in symptoms was observed at the 440 microgram dose. A significant decrease in eosinophil counts paralleled clinical improvement in all triamcinolone acetonide groups. Physicians and patients rated triamcinolone acetonide significantly (P less than .05) more effective than placebo. Responses of adult and adolescent patients were comparable. Adverse experiences, clinical laboratory values, and results of physical examinations were unremarkable and comparable between the triamcinolone acetonide and placebo groups. We conclude that triamcinolone acetonide is safe, well tolerated, and superior to placebo as a once-a-day treatment for seasonal allergic rhinitis.

Administration, Intranasal↗
PubMed1990

[Endoscopic neodymium YAG laser therapy of colorectal adenomas and cancers].

Endoscopic Nd:YAG laser therapy (lambda = 1.06 microns; 80-100 W) of colorectal neoplasia is indicated in: 1. Premalignant, sessile adenoma. After snare resection for histologic estimation of dignity laser ablation is curative when it is benign. 2. Obstructed colorectal cancer can be recanalized preoperatively to perform orthograde bowel lavage, total colonoscopy and elective primary tumour resection. 3. Inoperable colorectal cancer can be irradiated palliatively by the laser to arrest bleeding, to avoid obstruction and to reduce protein and electrolyte secretion.

Colonic Polyps↗
PubMed1990

Development of a high performance liquid chromatography method for the simultaneous measurement of prednisone and prednisolone.

An improved high performance liquid chromatographic assay (HPLC) is presented for the quantitative determination of prednisone and its main metabolite prednisolone. This HPLC assay, employing a UV-detector and dexamethasone as an internal standard, provides a selective and sensitive determination of glucocorticoids in plasma. The advantage of this method is the possibility of simultaneously measuring exogenic and endogenic glucocorticoids. The lower limit of quantification is 5 ng/ml.

Chromatography, High Pressure Liquid↗
PubMed1989

The primary structure of the hemoglobin of the electric eel (Electrophorus electricus).

The blood of the Electric Eel contains only one hemoglobin component. The primary structures of the alpha- and beta-chains are presented. These were separated by high-performance liquid chromatography, using a new kind of buffer system. The alpha-chains are acetylated, and consist of 142 residues, while the beta-chains are not blocked, and consist of 147 residues. The phylogenetic distances between these and the alpha- and beta-chains of human hemoglobin are 48 and 50% amino-acid exchanges, respectively. The relationship between primary structure and the Bohr effect and Root effect is discussed, especially the significance of the serine found in position F9 beta.

Amino Acid Sequence↗
PubMed1989

The primary structure of electric ray hemoglobin (Torpedo marmorata). Bohr effect and phosphate interaction.

The blood of the Electric Ray contains a number of hemoglobin components. The primary structures of the alpha- and beta-chains of the main components are presented. These chains were purified by high-performance liquid chromatography, using a new buffer system. The alpha-chains consist of 141 residues, and the beta-chains of 142 residues; both are unblocked. The phylogenetic distances from human alpha- and beta-chains are 55% and 64% amino-acid exchanges, respectively. The relationship between primary structure and the lack of both a Bohr effect and any effector affinity is discussed, and interpreted on a molecular level with reference to the sequence presented. For the Bohr effect, the mutation beta 89 Asp----Lys is significant, while the mutations beta 2 His----Ser, beta 82 Lys----Asn and beta 142 His----Cys are important for the lack of effector affinity.

Amino Acid Sequence↗
PubMed1989

[Endoscopic use of the neodymium YAG laser in the upper and lower gastrointestinal tract].

Endoscopic neodymium-YAG laser therapy for the gastrointestinal tract has been proved since 1975. Mortality and time of convalescence of patients treated with laser for acute or potential bleeding lesions have been markedly reduced in contrast to surgery. Sessile neoplastic polyps can be removed endoscopically by laser. Laser recanalization of obstructed carcinoma or scars in the upper and lower gastrointestinal tract to relieve dysphagia or ileus improves the patient's quality of life and has benefits for subsequent operations.

Colonic Polyps↗
PubMed1987

Palliative and pre-operative endoscopic neodymium-YAG laser treatment of colorectal carcinoma.

Using endoscopic neodymium-YAG laser application permits successful treatment of ulcerated bleeding cancer. Further, palliative, ablative laser irradiation of tumors in inoperable patients avoids obstruction. Pre-operative recanalization of obstructive colorectal cancer causing ileus or subileus permits pre-operative orthograde bowel lavage as well as total colonoscopy, thus converting emergency surgery with staged procedures or intra-operative colon lavage into normal elective primary resection with all preoperative diagnostic and treatment modalities.

Adult↗
PubMed1987

Chemistry of gas-phase sequencing: alternative bases.

The currently used base for gas-phase sequencing, trimethylamine, can be substituted by more hydrophobic tertiary amines without any problems. We used mainly N,N-dimethylallylamine and 3-(dimethylamino)propyne, both as aqueous solutions at constant temperature (40 degrees C). The advantages of these bases, which are liquids at room temperature, are their easy to regulate dosage, better stability and easier method of purification. The results of degradation with these bases are comparable with those obtained with trimethylamine.

Alkynes↗
PubMed1986

Physiology and tonotopic organization of auditory receptors in the cricket Gryllus bimaculatus DeGeer.

Physiological recordings were obtained from identified receptors in the tympanal organ of Gryllus bimaculatus. By immersing the prothoracic leg in Ringer solution and removing the anterior tympanic membrane the auditory receptors were exposed without significantly altering the frequency response of the auditory organ (Fig. 1). Each receptor was tuned to a specific sound frequency. For sound frequencies below this characteristic frequency the roll-off in sensitivity decreased from 20-30 dB/octave to 10-15 dB/octave as the characteristic frequency of receptors increased from 3-11 kHz (Fig. 4A). For each individual receptor the slope, dynamic range and maximum spike response were similar for different sound frequencies (Fig. 9A). The receptors were tonotopically organized with the characteristic frequency of the receptors increasing from the proximal to the distal end of the array (Figs. 5, 6). Several receptors had characteristic frequencies of 5 kHz. These receptors were divided into two groups on the basis of their maximum spike response produced in response to pure tones of increasing intensity (Fig. 7). Independent of the tuning of the receptor no two-tone inhibition was observed in the periphery, thus confirming that such interactions are a property of central integration.

Adaptation, Physiological↗
PubMed1986

Preoperative neodymium-YAG laser treatment of obstructive colon cancer.

Present conventional surgical therapy of obstructive colon cancers of the right colon is primary resection, whereas in the left colon it is a two-stage or three-stage operation with a temporary colostomy. Morbidity and mortality rates in staged operations are still as high as 40% and 24%, respectively. Preoperative recanalization of obstructive cancers by neodymium-YAG laser vaporization will tend to relieve the symptoms of ileus and will permit preoperative peroral bowel lavage. For this reason primary resection with primary anastomosis is practicable in patients who have recovered from symptoms of ileus. In 27 cases who had been operated on with left-side hemicolectomy or anterior resection, the mortality rate was 3.7% (1/27). The total inpatient mortality rate of all laser-treated patients who had been operated on by different operative procedures, or who had not been surgically treated, was 8.8% (5/57).

Colonic Neoplasms↗
PubMed1986

Endoscopic neodymium:YAG laser coagulation in gastrointestinal hemorrhage.

The aim of a resolute, endoscopic treatment in acute gastrointestinal hemorrhage by a neodymium:YAG laser is to prevent massive loss of blood and to avoid transformation of the hemorrhagic shock event into an irreversible state. Parallel to endoscopic procedure treatment of coagulopathies is necessary. 1,029 (94%) out of 1,092 acute bleeding episodes of 852 unselected patients were treated successfully. In bleeding esophageal varices, reduction of mortality from 70% to 36.2% has been achieved by sclerotherapy following laser coagulation of the acute bleeding. Compared with the results of surgery the mortality rate of bleeding acute ulcers has been reduced from 58% to 23.4%, and of bleeding chronic ulcers from 25% for resection and 15% for vagotomy to 0%. For optimal treatment of the patients close cooperation with surgeons is also desirable.

Acute Disease↗
PubMed1986

Effects of long-term ergoloid mesylates ('Hydergine') administration in healthy pensioners: 5-year results.

Five-year results are reported of a controlled long-term comparative study to assess the effects of ergoloid mesylates (1.5 mg 3-times daily) and placebo on medical, psychological and electrophysiological variables. Initially, 148 healthy elderly volunteers of both sexes were included. Eighty-nine subjects (48 on ergoloid mesylates and 41 on placebo) are still in the double-blind study; 39 subjects have left the trial for various reasons (6 deaths, 25 drop-outs due to disease, and 8 withdrawals) and 20 subjects are participating under 'open' conditions. Formal statistical comparison of the two groups in terms of 10 medical and psychometric outcome variables did not produce significant differences. However, a number of relevant findings and trends with regard to the effects of ergoloid mesylates were established: the drug was well tolerated objectively and subjectively; subjective complaints such as frequent dizziness, cardiac symptoms and leg cramps were improved; there was less increase than on placebo in the number of subjects with pathological ECG findings; there was less increase than on placebo in the number of subjects taking digitalis; fewer subjects than in the placebo group had an increase in the number of major diagnoses; the decrease in some lipid fractions was more pronounced than on placebo; and performance in some psychometric tests (WAIS Vocabulary, WAIS Performance) was better in the ergoloid mesylates group. None of these findings, by itself, would be evidence of a dramatic effect of ergoloid mesylates on the participants in the double-blind trial. Taken together, however, they fall into a pattern, suggesting that ergoloid mesylates was partly effective in maintaining physical and mental health in these healthy elderly individuals. The finding of more disease-related and symptom-related drop-outs in the placebo group (25 vs. 20 in the ergoloid mesylates group) supports this assumption. Furthermore, the fact that a number of subjects who had left the double-blind trial for medical reasons improved on subsequent ergoloid mesylates administration may be seen as a further argument in favour of a prophylactic effect of ergoloid mesylates on pathological concomitants of ageing.

Aged↗
PubMed1985

The antitumor activity of di-n-butyltin(IV) glycylglycinate, and the correlation with the structure of dialkyltin(IV) glycylglycinates in solution studied by conductivity measurements and by infrared, nuclear magnetic resonance, and Mössbauer spectroscopic methods.

The in vivo activity of Bu2nSnGlyGly, Na(Cl2GaGlyGly), and ClGaGlyGly (GlyGly2- = glycylglycinate) has been investigated in connection with a number of tumors. Positive results have been obtained only for the Bu2nSnIV complex in the case of leukemia P-388. In order to try to interpret the pharmacological data on a molecular basis, the nature of the species present in solutions of AlK2Sn GlyGly complexes, as well as the reactivity of aqueous Me2SnGlyGly, have been studied. The presence of chelated species (I), Figure 1, in organic solvents, and the equilibrium (I) in equilibrium (II), Figure 1, in water and mixed water-organic solvent systems, have been inferred from conductance measurements, as well as from studies by Mössbauer (in frozen solution), 1H, 13C, and 119Sn NMR, and ir spectroscopy. Moreover, solvated (II) would release AlK2SnIV moieties, as evidenced by the slow formation of (Me2SnO)n from aqueous Me2Sn GlyGly. The involvement of (I) and (II) in the transportation of these drugs across cell membranes is discussed.

Animals↗
PubMed1985

Synaptic connectivity between cricket auditory interneurons as studied by selective photoinactivation.

Sound detection and localization are important for crickets. Interneurons located in the prothoracic ganglion play a crucial role in the initial processing of the auditory inputs. Two of the most readily recorded and dye-marked auditory interneurons in the prothoracic ganglion of the cricket are the omega cells (ON/1) and the ascenders (AN/2). By using a new photoinactivation technique to selectively inactivate these cells, the synaptic relationship between them could be studied. Our results indicate that the ON/1 cells are connected to each other with reciprocal inhibitory synapses. An ON/1 cell responds to contralateral stimulation with strong inhibition mediated by the other ON/1 cell. When one cell is killed, this inhibition is removed, and a weak excitatory response is unmasked. Unlike the ON/1 cell, AN/2 produces an inhibitory response when stimulated ipsilaterally to the cell body side, and this response is also removed when the ipsilateral ON/1 cell is killed, providing strong evidence that ON/1 is the source of the inhibition. As with the ON/1, the inhibition is replaced by weak excitation.

Animals↗
PubMed1979

Central projections of fibers in the auditory and tensor nerves of cicadas (Homoptera: Cicadidae).

The auditory and tensor nerves of cicadas are mixed nerves containing both afferent and efferent elements. In 17-year cicadas, and in Okanagana rimosa, the auditory nerve contains afferents from body hairs, from the detensor tympani-chordotonal organ, and some 1300--1500 afferents from the hearing organ. Within the fused metathoracic-abdominal ganglionic complex the receptors from both the auditory and tensor nerves form a neuropilar structure that reveals the metameric organization of this complex. A few fibers run anteriorly, projecting into the meso- and prothoracic ganglia. Within the ganglionic complex a division of auditory nerve afferents into a dense intermediate and a more diffuse ventral neuropile is observed. In addition, a dorsal motor neuropile is outlined by arborizations of the timbal motor neuron. This neuron is one of several efferent cell types associated with the auditory nerve, and there is an indication that several efferent fibers innervate the timbal muscle. There is anatomical evidence for a possible neuronal coupling between the bilaterally symmetrical large timbal motor neurons. In general, central projections from the auditory and tensor nerves support evidence of a structural "layering" within the CNS of insects.

Animals↗
PubMed1979

[Therapy groups with patients and nursing staff in a geriatric hospital (author's transl)].

Within a very short time the non-demented, chronically hospitalized old person turns into a hospital-activity-oriented patient. He thereby gives up a considerablle part of his personality. In order to understand this process, special attention has to be paid to the intertwining of the dynamics of the chronic geriatric patient with the dynamics of the nursing staff. As a therapy experiment we have been conducting parallel talk-groups with patients and with their nursing staff for one year. As a result, the patients showed increased activity, increased dynamism, improved contact ability, increased interest in the outside world, and improved affect. The nursing staff also reported improvement of the group-patients' condition on the floor. With the nursing staff we found a reduction of the defensive mechanisms, a separation from old nursing-role definitions, acceptance and encouragement of the patients in their new role, and improved satisfaction with patient contact. On the other hand, the nursing staff expects more personal contact to come from the patients. The groups have shown to be useful and have to a large extent reached the therapy goals.

Aged↗