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Biomedical subjects

C Holm

Publications and source records attributed to C Holm.

At least 163 records · Page 9Linked to original sources
PubMed1982

Sensitivity to the Yeast Plasmid 2mu DNA is conferred by the nuclear allele nibl.

Two strains of Saccharomyces carlsbergensis that lacked the plasmid 2mu DNA responded differently when the plasmid was introduced into them. In one strain, cells lacking 2mu DNA ("cir0") produced the normal "smooth" colony morphology, but cells bearing 2mu DNA ("cir+") produced heterogeneous "nibbled" colonies. In the second strain, both cir+ and cir0 strains exhibited a smooth colony morphology. Crosses between these strains revealed that a single recessive nuclear gene, called nibl, conferred the nibbled colony morphology in the presence of 2mu DNA. By a series of backcrosses, nibl was introduced into a Saccharomyces cerevisiae background. nibl caused a nibbled colony morphology in this background just as it did in S. carlsbergensis. nibl was mapped to the left arm of chromosome XVI. Twelve independent smooth revertants were isolated from two nibl [cir+] strains. Seven were analyzed, and all were found to be chromosome VII disomes. Chromosome VII disomy and suppression of the nibbled phenotype cosegregated in crosses. Thus, chromosome VII disomy can suppress the nibbled phenotype. The results of other experiments (C. Holm, Cell 29:585-594, 1982) indicate that the nibbled colony morphology is the result of lethal sectoring and that the lethality is caused by a high copy number of 2mu DNA. I suggest, therefore, that the product of the nibl gene may play a role in controlling the copy number of 2mu DNA. Possible models for the suppression of the nibbled phenotype by chromosome VII disomy are discussed.

Alleles↗
PubMed1979

[Emancipatory rehabilitation in logopedics -- comments from the medico-rehabilitative viewpoint (author's transl)].

In the Federal Republic of Germany speech disturbances, as sub-group of communication disorders, are treated by two professional groups: a) free practising logopedists who chose their team themselves as well as logopedists who are working in a clinic team and b) "Sprachheilpädagogen" (speech therapists) working at special education facilities. Irrespective of the age of the patient, treatment by logopedists is paid by the health insurance funds; special education therapy is paid by the financially responsible school agencies. The basis of the disease is not a deviation but a disturbance of the central nervous system which can be determined by medical, phoniatric-neurological diagnostic means.

Germany, West↗
PubMed1978

[EEG-results in early-treated children with phenylketonuria 4 through 10 years under treatment (author's transl)].

EEG-results in 21 children with Phenylketonuria (PKU), put on a diet at least since their 3rd month of life, now aged 4 through 10 years, with normal psychomotor development, lacking abnormal neurological signs, are compared with the results in 796 healthy children of the same age. Visual evaluation and frequency analysis of the background activity of the EEGs reveal no differences between children with PKU and controls. Generally, there is no close correlation between mean plasma levels of phenylalanine (phe-means) during treatment, and the composition of the EEG when combined age groups are compared. But a trend can be demonstrated: In the small group of 8 years old children phe-means up to 6 mg-% can be associated with a faster (alpha), and phe-means above 6 mg-% with a slower (theta) background activity. The frequency of metabolic derailment (single phe-values above 10 mg-%) does not correlate with the EEG. Focal and generalized hypersynchronous activity (HSA) is observed significantly more often even in early treated, normally developing children with PKU. In children aged 4--8 years, HSA is associated with a high proportion of slow waves compared with those who do not display HSA. In children 9 and 10 years old, however, no such differences can be seen. It is hypothesised that even early treated children with PKU, in their first years show a retardation in the development of their background activity but catch up by 9--10 years. It still remains uncertain whether further age-appropiate development of the EEG can be observed after liberating or discontinuing the dietary regimen at this age.

Alpha Rhythm↗
PubMed1977

Biochemical and physiological studies of the yeast virus-like particle.

A study was made of the virus-like particle (VLP) of Saccharomyces cerevisiae S7. This strain contains elevated amounts of P1 double-stranded ribonucleic acid (dsRNA) but no P2 dsRNA. The amount of dsRNA contained in cells grown on a fermentable carbon source (glucose) was compared with that in cells grown on a nonfermentable carbon source (ethanol). It was found that ethanol-grown cells contain higher levels of dsRNA than glucose-grown cells. In the former, the amount of dsRNA increased during the logarithmic phase of growth, whereas in the latter it increased during the transition from the logarithmic to the stationary phase. A method was devised to isolate VLPs from these cells by using CsCl gradients, and the yield was assessed by monitoring the recovery of dsRNA. Three proteins were found to be tightly associated with these particles. They have molecular weights of 75,000, 53,000, and 37,000. Together they account for almost all of the coding capacity of the P1 dsRNA that the VLP contains.

Electrophoresis, Polyacrylamide Gel↗
PubMed1976

The economy of the EMI-scanner.

It is shown-taking in consideration the local circumstances-that the EMI scanning of the brain is less expensive than pneumoencephalography percutaneus carotid angiography or cerebral four vessel angiography.

Costs and Cost Analysis↗
PubMed1975

[Age-dependent electric response audiometry (ERA)-findings in correlation with speech development (author's transl)].

The occurrence of periods of speech-certainty and speech-uncertainty can be observed in normal as well as in children impaired with hearing, voice and speech defects. This behaviour of voice and speech development has not yet been explained by subjective pure-tone or speech audiometry. 19 normal children were grouped into four age populations according to electroglotto- and phonographic analysis. This collective was then examined by Electric Response Audiometry (ERA) at the frequencies of 0.5 kHz, 1.0 kHz, 2.0 kHz, and 4.0 kHz. Speech-certainty was observed at a mean age of 4.5 years (Group II) and 6.5 years (Group IV), whereas speech-uncertainty was found at a mean age of 2.5 years (Group I) and 5.5 years (Group III). The supraliminal ERA results of contralteral pickup were evaluated in amplitude and in behaviour of latency. Because of the variety of ERA-characteristics, the age-dependent and frequency-specific development of the acoustic system is figured by integration below the characteristics in the supraliminal range. The mathematical result shows two opposite regions as well as the "hearing dynamic" as at the "dynamic of the behaviour of latency": a low-frequency region of 0.5 and 1.0 kHz and a high-frequency region of 2.0 and 4.0 kHz. Evaluation of the electroglottograms following Fourier's analysis shows a typical amplitude spectrum at speech-certainty and at speech-uncertainty.

Age Factors↗
PubMed1975

[Objective measurements of airway resistance in recurrent nerve paralysis and hypotonic dysphonia].

Respiratory obstructions of the glottis may be reliably diagnosed at any time with a body plethysmograph used in pulmonary function testing. While respiratory resistance at 27.1 mm H2O/l and sec was only slightly increased in 35 patients with unilateral recurrent nerve paralysis and not even perceived by most of them, considerably increased resistance was found in 65 patients with bilateral paralysis. Critical lifeendangering obstructions of the respiratory system were not observed. Intra- and extralaryngeal lateral fixations of the vocal cord were carried out in 29 subjects. We observed unrestricted breathing and alveolar ventilation with respiratory resistance of 25 to 44 mm H2O/l and sec even under physical strain. Additional optimal phoniatric results and speech function is present in this range. 14 patients operated according to the endolaryngeal method of Thornell 1948 showed the best functional results. In cases of unilateral recurrent paralysis and hypotonic dysphonia we were able to measure the glottic resistance during phonation by using the modified interruption technique. The values were clearly subnormal at a median of 65 to 79 mm H2O/l and sec. In 43 cases treated with teflon injections a 50% increase of the airway resistance during phonation was observed. These findings correlate with the positive subjective experiences of the patients.

Adult↗