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Biomedical subjects

H Kaufmann

Publications and source records attributed to H Kaufmann.

At least 127 records · Page 7Linked to original sources
PubMed1991

Investigation of a self-compatible mutation in Solanum tuberosum clones inhibiting S-allele activity in pollen differentially.

A self-compatible (SC) mutation, identified in dihaploid lines of Solanum tuberosum, was investigated. It has previously been proposed that this mutation arose by translocation of an S-allele (S1) to a new chromosomal location. When present in pollen grains of genotype Sx, it overcomes the incompatibility reaction normally seen on styles carrying the Sx allele. However, when present in S1-bearing pollen grains, the normal incompatibility reaction on styles carrying S1 is still observed. Using probes for the potato (S. tuberosum L.) S-linked glycoprotein (SLG) genes, it is shown that no sequence derived from SLG allele S1 can be linked to the presence of the SC mutation. The polypeptide product of the SLG allele S1 is also not detectable in SC mutant lines unless the S1 allele is also present. It is concluded that the SC mutation arose in a sequence other than that encoding the SLG S1 polypeptide, either in a part of the S-locus that is distinct from the S-gene, or at a different locus, giving rise to an inhibitor.

Alleles↗
PubMed1991

Differential effect of L-threo-3,4-dihydroxyphenylserine in pure autonomic failure and multiple system atrophy with autonomic failure.

Treatment with L-threo-3,4-dihydroxyphenylserine (L-threo-dops), a synthetic precursor of norepinephrine, significantly increased upright blood pressure in patients with multiple system atrophy but had no effect on the upright blood pressure of patients with pure autonomic failure. These results suggest that the site of action of L-threo-dops is central and that its pressor effect requires intact peripheral sympathetic neurons.

Adult↗
PubMed1991

[Ocular circulatory changes in halothane-nitrous oxide intubation anesthesia with special reference to arterial CO2 partial pressure. I. Phenomenology of changes].

UNLABELLED: In 20 patients (5 with cataract, 15 with strabismus), general anesthesia was performed using halothane (inspiratory concentration: 0.5 vol.%) and nitrous oxide (65 vol.%); thiopental was employed for induction of anesthesia, vecuronium and succinylcholine were used for neuromuscular blockade prior to intubation. In series 1, the patients were slightly hyperventilated (PCO2 33 mmHg, on average). In series 2, the arterial PCO2 was changed in a range between 20 and 45 mmHg. By means of oculo-oscillo-dynamography, we determined the systolic retinal and ciliary perfusion pressures (PPs,ret and PPs,cil) as well as the respective ocular blood pressures (Ps,ret and Ps,cil), the ocular pulsation volume (PVoc) and the pulsatile ocular blood flow (Fp,oc = PVoc x heart rate). The intraocular pressure (Pio) was measured with the Draeger hand-applanation tonometer. Results of series 1: Measured 5 and 15 min after intubation, PPs,ret was reduced by averages of 12.5 and 20.2 mmHg, respectively, corresponding to decreases of 13.1 and 21.2% compared to the initial values. Ps,ret was decreased by 15.4 mmHg (14.2%) 5 min after intubation and by 27.1 mmHg (25.0%) 15 min after intubation. The ciliary pressures (PPs,cil and Ps,cil) were changed by similar amounts. PVoc was reduced by 0.3 microliters (50.8%) during both time periods after intubation. Fp,oc was lowered by 19.5 microliters/min (41.0%) and by 26.4 microliters/min (55.5%), measured 5 and 15 min after intubation, respectively. Pio was decreased by 1.6 mmHg (11.3%) and by 7.6 mmHg (53.5%), respectively. The systolic brachial artery pressure was reduced by 12.6 mmHg (9.5%) 5 min after intubation and by 29.1 mmHg (21.9%) 15 min after intubation. The diastolic branchial artery pressure showed a slight initial increase, followed by a small decrease. All changes were highly significant (P less than 0.001; 1-factor analysis of variance plus Scheffé test). Results of series 2: In a PCO2 range between 40 and 45 mmHg (normo-until slight hypoventilation; determined 5 min after intubation), PVoc and Fp,oc averaged 0.43 microliter and 42.9 microliters/min, respectively. In a PCO2 range between 30 and 35 mmHg (slight hyperventilation), PVoc and Fp,oc averaged 0.38 microliters and 36.1 microliters/min, respectively; and in a PCO2 range between 20 and 25 mmHg (forced hyperventilation), they averaged 0.21 microliter and 22.8 microliters/min, respectively. All other variables were not dependent on the PCO2 level. CONCLUSIONS: The lowering of PVoc and Fp,oc, observed during halothane-nitrous oxide anesthesia--especially with forced hyperventilation-, may be interpreted as reduced pulsatile choroidal blood flow.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1991

[Changes in ocular circulation in halothane-nitrous oxide intubation anesthesia with special reference to the arterial CO2 partial pressure. II. Mechanisms of change].

UNLABELLED: In part I of this study [Hessemer and associates, Klin. Mbl. Augenheilk. 199 (1991) 346-355] the phenomenology of the ocular circulatory changes, found during general anesthesia using halothane and nitrous oxide, has been described. These changes are analyzed with respect to their mechanisms.-- RESULTS: There was a significantly (P less than 0.05) linear relation between the anesthesia-induced reduction of the systolic ocular (retinal and ciliary) blood pressures and the decrease of the systolic brachial artery pressure (delta Ps,bra). The same relation was present between the reduction of the systolic ocular (retinal and ciliary) perfusion pressures and delta Ps,bra. The correlation coefficients for the designated relations ranged between 0.37 and 0.58. The relation between the anesthesia-induced intraocular pressure reduction and delta Ps,bra was--in tendency--linear (P = 0.07), at least for the time period 5-15 min after intubation; the correlation coefficient amounted to 0.37. The reduction of both the ocular pulsation volume (PVoc) and the pulsatile ocular blood flow (Fp,oc) did not depend on the systemic blood pressure, but on the arterial CO2 tension (PCO2): Decreasing PCO2--i.e., increasing hyperventilation--was paralleled by decreases of PVoc and Fp,oc. The relations PVoc vs. PCO2 and Fp,oc vs. PCO2 were significantly linear (P less than 0.01), the correlation coefficients ranged between 0.58 and 0.7.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Endotracheal↗
PubMed1991

["Lateralis splitting" in total oculomotor paralysis with trochlear nerve paralysis].

In two cases of 3rd nerve palsy and trochlear palsy we performed a new transposition procedure. This procedure consists of splitting of the lateral rectus muscle and transposition of the upper half to a retroequatorial point near the nasal superior vortex vein. The lower half is transposed to a retroequatorial point near the nasal inferior vortex vein. In the first case we linked the two halves with fascia late. The horizontal deviation was diminished by 15-20 degrees.

Adult↗
PubMed1990

Evaluation of visual fields by ophthalmologists and by OCTOSMART program.

The introduction of Goldmann perimetry standardized measuring conditions as much as possible. In spite of this, it had been possible for the perimetrist to influence the results of perimeter measurements. The introduction of computer-controlled perimetry, however, has largely eliminated the influence of the investigator on perimetry results. Nevertheless, the interpretation of a perimetric result in the everyday clinical situation is still extensively subjectively coloured and is liable to vary, depending on the doctor carrying it out. The OCTOPUS Program G1 was introduced a few years ago and used above all for glaucoma. This program greatly simplified visual field assessment thanks to its visual field indices. The indices make it possible to compare visual field results with those of a normal population. The present introduction of the OCTOSMART program represents a further step forward. This program analyses measured visual fields with the aid of standardized, statistical criteria based on a large, normal value study. This analysis standardizes and thereby simplifies the interpretation of visual field results. This study compares the outcome of the OCTOSMART program with visual field interpretations by eye doctors.

Evaluation Studies as Topic↗
PubMed1990

Atrial natriuretic factor in human autonomic failure.

To investigate whether excessive circulating levels of atrial natriuretic factor (ANF) are responsible for orthostatic hypotension and nocturnal polyuria in patients with autonomic failure, we determined the circadian variation in the plasma concentration of ANF as well as the response of this peptide to changes in posture and extracellular fluid volume in patients with autonomic failure. We found that the plasma concentration of ANF was significantly lower in patients with autonomic failure than in controls. Patients with autonomic failure had a significantly higher urinary sodium excretion during the night (8 PM to 8 AM) than during the day (8 AM to 8 PM), and the plasma concentration of ANF significantly decreased during the night in these patients, indicating that high circulating levels of ANF were not the cause of the nocturnal natriuresis. Furthermore, circulating levels of ANF responded appropriately to reductions in right atrial pressure induced by head-up tilt and extracellular fluid volume changes induced by mineralocorticoid administration. These results indicate that exaggerated circulating levels of ANF are not responsible for the orthostatic hypotension or nocturnal natriuresis in patients with autonomic failure, and that appropriate regulation of ANF occurs in patients with autonomic failure.

Adult↗
PubMed1990

[Diagnosis and treatment of ophthalmoplegia].

The author discusses the signs and symptoms appearing in the course of so called noncommittant squints. Noncommittant squints are divided into squints caused by paresis or by a total paralysis of the motor muscles. One can divide the therapeutical procedure into the conservative and surgical treatment. The conservative treatment is carried out for one year since the onset of the palsy. After 12 months in the case of a lack of improvement a surgical intervention is performed. Surgical operations are divided into 3 types: 1) Rotation of the eye, that is to say operation of a recession-resection type--on the affected eye, 2) the principle paresis-counter-paresis or interventions performed on the muscles of the healthy eye, 3) transpositions of the muscles.

Eyeglasses↗
PubMed1990

[The so-called bridle operation].

In two cases of palsy of the third nerve we found a paresis of two neighboring rectus muscles without cyclotropia (i.e., palsy of the medial rectus muscle an the superior rectus muscle). In these cases, we performed a new procedure, which consists in transpositing the two functioning rectus muscles at the insertion of the two paretic muscles. The effect is greater if the transposed muscles are linked with fascia lata behind the globe, as performed in the second case.

Aged↗
PubMed1989

[Congenital methemoglobinemia with cytochrome-b5-reductase deficiency: 4th Swiss family].

In a female newborn presenting with pronounced cyanosis in the absence of cardiopulmonary disease, the cyanosis was due to methemoglobinemia of 33% at birth and 17% at 24 hours (upper limit 0.5%) which was found to be secondary to deficiency of red blood cell cytochrome b5 reductase (EC 1.6.2.2.). Only residual activity of this enzyme was measurable, thus indicating homozygosity. Both parents were found to be heterozygous for this inherited disease. Of the six sisters and brothers of the newborn's father, five were investigated and all found to be heterozygous for the defective allele. Measurement of cytochrome b5 reductase showed both soluble and membrane bound fractions to be affected equally in the red cells of the baby's heterozygous parents.

Adult↗
PubMed1989

Intracerebral dialysis monitoring of striatal dopamine release and metabolism in response to L-dopa.

We have used intracerebral dialysis to monitor the striatal extracellular fluid (ECF) in rats with unilateral lesions of the nigrostriatal dopamine (DA) pathway. Dialysis samples were collected before and after L-dihydroxy-phenylalanine (L-DOPA) administration both in the presence and absence of carbidopa, an extracerebral DOPA decarboxylase (DDC) inhibitor. The baseline ECF levels of DA, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) were always higher in the intact than in the lesioned striata. In the normal striata, dopamine (DA) concentrations increased following L-DOPA administration. Pretreatment with carbidopa prolonged the duration of the DA increase. In the lesioned striata, DA levels increased following L-DOPA administration only in animals pretreated with carbidopa. Following L-DOPA administration, striatal HVA and DOPAC levels increased considerably more in animals not pretreated with carbidopa than they did in pretreated animals. This increase was particularly marked in the lesioned striata and leads us to conclude that extracerebrally produced HVA and DOPAC can enter the brain extracellular space.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

[Graphic and numerical presentation of visual field findings].

This article reviews the various ways in which visual field defects can be represented and the advantages and disadvantages of the most commonly used methods. In addition, the G1 analysis program, which will soon be available, is briefly described.

Computer Graphics↗
PubMed1989

[The Bebié curve (cumulative defect curve) for differentiating local and diffuse visual field defects].

Damage to the visual field can be diffuse as well as local. In the absence of local defects, diffuse damage can easily be recognized with the help of the visual field indices. In the presence of scotomas, diffuse damage in the remaining part of the visual field which is better or "normal" is more difficult to recognize and quantify. Bebié et al. have published a new method of assessing the visual field in relation to normal values. They present the results with a cumulative defect curve, a method which we have called the "Bebié curve". This method allows an easy recognition of diffuse as well as local damage. In our study we evaluate the clinical application of the Bebíe curve in different diseases and for the follow-up of the visual field.

Computer Graphics↗
PubMed1989

[Combined oblique muscle surgery in bilateral trochlear paralysis].

Fifteen patients with bilateral trochlear paresis underwent oblique muscle surgery. In 12 cases, a superior oblique tuck and inferior oblique recession were performed uni- or bilaterally. In 3 cases, a superior oblique muscle tuck was sufficient. Excyclotropia and vertical deviations in adduction, primary position and abduction were alleviated by surgery in most cases. The upper and lower limits of the field of single binocular vision were on average 15 degrees in the upward-gaze and 25 degrees in the downward-gaze. The presence of postoperative Brown syndrome was rarely disturbing to the patient. Postoperatively, the effects of surgery decreased only slightly over time. We found that in cases of bilateral superior oblique palsy, a tuck in one or both superior oblique muscles sufficed only when the excyclotropia in the primary position did not exceed 15 degrees, when the vertical deviation in adduction did not exceed 3 degrees and when the V-pattern was minimal. We found that uni- or bilateral surgery on both superior and inferior oblique muscles could successfully alleviate excyclotropia of more than 20 degrees with a vertical deviation in the primary position of more than 5 degrees.

Humans↗
PubMed1989

[Method and clinical significance of cerebrospinal fluid spectrophotometry].

The results of the spectrophotometric analysis of 932 cerebrospinal fluid specimens are presented. The specimens were obtained from 95 patients with subarachnoid and intracerebral hemorrhages, 75 patients with traumatic head injuries, 40 patients with infectious diseases of the central nervous system, 302 patients with cerebrovascular accidents and 302 patients suffering from a variety of diseases such as multiple sclerosis, herniated intervertebral discs and vasomotor headache. Normal cerebrospinal fluid is colourless and shows a spectrophotometric absorption characterized by a flat curve with decreasing absorption from 350 to 650 nm. In disease states Oxy-Hemoglobin, Met-Hemoglobin and Bilirubin can be identified in cerebrospinal fluid. These pigments, when present in cerebrospinal fluid, change the spectrophotometric curve due to their specific absorption spectra. According to the quantitative relationship between the pigments and their chronological order of appearance in the cerebrospinal fluid, typical spectrophotometric patterns have been delineated. The spectrophotometric absorption curve of a hemorrhage due to rupture differs from that of a diapedetic hemorrhage. Moreover, tap bleeding results in an absorption curve which can be differentiated early from that of a subarachnoid hemorrhage. Finally, artifacts due to desinfectants can easily be identified. It is concluded that the spectrophotometric analysis of cerebrospinal fluid gives helpful information in subarachnoidal-hemorrhage, subdural and intracerebral hematoma, in contusions of the brain, carcinomatosis of the leptomeninx, spinal tumor and meningoencephalitis of unknown origin.

Bilirubin↗
PubMed1988

Hormonal evaluation and autoimmune background in pruritic urticarial papules and plaques of pregnancy.

There is little insight into the pathogenesis of most of the dermatoses specifically associated with pregnancy. We evaluated the hormonal profile and the autoimmune background in 11 pregnant women with pruritic urticarial papules and plaques of pregnancy. No statistically significant difference was found between the serum levels of the beta-subunit of human chorionic gonadotropin, estradiol, cortisol, and urinary estriol of the patients and gestational age-matched control subjects. No autoantibodies were found in the patients' group. We conclude that patients with pruritic urticarial papules and plaques of pregnancy have no hormonal alterations when compared with normal pregnant women and that no known major autoimmune background plays a part in the pathogenesis of the disease.

Adult↗