Cell movement and shape are non-random and determined by intracellular, oscillatory rotating waves in Dictyostelium amoebae.

We present evidence for a mechanism of eukaryotic cell movement. The pseudopodial dynamics and shape of Dictyostelium discoideum amoebae were investigated using computer-supported video microscopy. An examination of the cell periphery by the novel method of serial circular maps revealed explicit, classical wave patterns, which indicate the existence of intrinsic intracellular oscillations. The patterns are generated by the transit of self-organized, super-positioned, harmonic modes of rotating oscillatory waves (ROWS). These waves are probably associated with the dynamics of intracellular actin polymerisation and depolymerisation. A Karhunen-Loève expansion was conducted on one cell during 10 min of locomotion using points each 10 degrees around the cell's boundary. The results show that only 2-3 modes are necessary to describe the most essential features of cell movement and shape. Based on this analysis, a wave model was developed, which accurately simulates the dynamics of cell movement and shape during this time. The model was tested by reconstructing the cell's dynamical form by means of the Karhunen-Loève transform. No difference was detected between this reconstruction and the actual cell outline. Although cell movement and shape have hitherto been viewed as random, our results demonstrate that ROWS determine the spatio-temporal expression of pseudopodia, and consequently govern cell shape and movement, non-randomly.

Financing biotechnology projects: lender due diligence requirements and the role of independent technical consultants.

An increasing number of biotechnology projects are being brought to commercialization using conventional structured finance sources, which have traditionally only been available to proven technologies and primary industries. Attracting and securing competitive cost financing from mainstream lenders, however, will require the sponsor of a new technology or process to undergo a greater level of due diligence. The specific areas and intensity of investigation, which are typically required by lenders in order to secure long-term financing for biotechnology-based manufacturing systems, is reviewed. The processes for evaluating the adequacy of prior laboratory testing and pilot plant demonstrations is discussed. Particular emphasis is given to scale-up considerations and the ability of the proposed facility design to accommodate significant modifications, in the event that scale-up problems are encountered.

Triaziflam and Diaminotriazine derivatives affect enantioselectively multiple herbicide target sites.

Enantiomers of triaziflam and structurally related diaminotriazines were synthesized and their herbicidal mode of action was investigated. The compounds caused light and dark-dependent effects in multiple test systems including heterotrophic cleaver and photoautotrophic algal cell suspensions, the Hill reaction of isolated thylakoids and germinating cress seeds. Dose-response experiments revealed that the (S)-enantiomers of the compounds preferentially inhibited photosystem II electron transport (PET) and algae growth with efficacies similar to that of the herbicide atrazine. In contrast, the (R)-enantiomers of the diaminotriazines were up to 100 times more potent inhibitors of growth in cleaver cell suspensions and cress seedlings in the dark than the (S)-enantiomers. The most active compound, the (R)-enantiomer of triaziflam, inhibited shoot and root elongation of cress and maize seedlings at concentrations below 1 microM. The meristematic root tips swelled into a club shape which is typical for the action of mitotic disrupter herbicides and cellulose biosynthesis inhibitors. Microscopic examination using histochemical techniques revealed that triaziflam (R)-enantiomer blocks cell division in maize root tips 4 h after treatment. The chromosomes proceeded to a condensed state of prometaphase but were unable to progress further in the mitotic cycle. Disruption of mitosis was accompanied by a loss of spindle and phragmoplast micotubule arrays. Concomitantly, cortical microtubules decreased which could lead to isodiametric cell growth and consequently to root swelling. In addition, a decline in cellulose deposition in cell walls was found 24 h after treatment. Compared to the (R)-form, triaziflam (S)-enantiomer was clearly less active. The results suggest that triaziflam and related diaminotriazines affect enantioselectively multiple sites of action which include PET inhibitory activity, mitotic disruption by inhibiting microtubule formation and inhibition of cellulose synthesis.

Ear damage caused by leisure noise.

Noise is a health risk. Recent findings suggest that leisure noise is a substantial danger especially to children, teenagers and young adults. Epidemiological studies of teenagers with no occupational noise exposure show an increasing number with a substantial and measurable irreversible inner ear damage. This is basically due to the wide spread exposition to very loud toys (pistols and squibs), crackers and exposure to electronically amplified music, e.g. from personal cassette players (PCP), at discos or concerts etc. Protection against irreversible ear damage by leisure noise has an important impact in preventive medical care. Therefore the general public must be informed that loud leisure activities may cause damage to the ear. In order to protect children, young people and adults, the legislature ought to set limits for sound levels in discos, concert halls and for music equipment and toys by establishing the necessary standards and regulations.

[The medicolegal judgement of noise induced hearing loss combined with other kinds of hearing impairment (author's transl)]. / Die gutachtliche Beurteilung der Lärmschwerhörigkeit bei gleichzeitigem Vorliegen anderer Gehörerkrankungen.

In cases of noise induced hearing loss, the medicolegal judgement of causality often is complicated by the coincidence of endogenous hearing impairments, which conceal the audiological characteristis and the degree of Nihl. The recognition of an occupational disease however is possible only when there is a dominant probability; the possibility of Nihl alone in sight of the labour conditions is not sufficient for this recognition. In such cases, the medical expert therefore, besides of an extensive audiological analysis, must have sufficient information on noise immission, on the course of hearing impairment in regard to working time, and on other diseases and accidents which possibly can influence hearing function.

Surgery of the round window.

Tympanotomy is routinely performed in our institution to control the round window membrane for patients with recurrent sudden deafness, with Meniere-like attacks, and those with Meniere's disease. In a large number of these patients, especially those with vertigo, perilymph fistula has been diagnosed. Most patients are free of attacks after the fistula has been closed, and in those with a short history of illness, hearing can become normal. In the future, closure of the round window membrane should be considered an important procedure in the treatment of inner ear dysfunctions.

[Hearing loss caused by leisure activity-induced noise]. / Schwerhörigkeit durch Freizeitlärm.

The number of persons with hearing disability in most countries is more than 10%. In developing countries of the third world, inflammations are the most important cause of hearing dysfunction, but in more civilized countries, more and more individuals are injured by a noisy environment and by noise that is individually produced. In this way, a great number of young people acquire defects of hearing which are not reparable. As a consequence the German government has tried to control the possible danger to the community from noise and has arranged that exposure to unnecessary noises be reduced by standards and regulation.

[Expert assessment of hearing loss within the scope of the social compensation law and the law regarding severely handicapped patients]. / Begutachtung von Schwerhörigkeit im Rahmen des sozialen Entschädigungsrechts und des Schwerbehindertengesetzes.

Special problems are described concerning expert opinions on hearing disability and hearing loss with regard to the German Social Rights for Compensation and the laws for handicapped persons. In some aspects there are similarities to the rights of accident insurance, but disability programs question only the degree of handicap present and not the source of the hearing loss. The expert opinion on the subject's ability to work in his or any other profession must only determine the patient's ability to hear and the tasks needed to fulfill the profession. Special attention is given to the problems arising from tinnitus.

[Expert assessment of noise-induced hearing loss with special reference to differentiation between noise-induced damage and other degenerative diseases of the ear]. / Die Begutachtung der Lärmschwerhörigkeit unter besonderer Berücksichtigung der Abgrenzung zwischen Lärmschaden und anderen degenerativen Erkrankungen des Hörorgans.

In patients with noise-induced hearing loss (NIHL) who also suffer from other degenerative diseases of the ear, a medicolegal opinion must be based on detailed knowledge of the pathophysiology of Corti's organ and on audiometric findings. Only with this special knowledge is it possible to differentiate accurately between NIHL and other types of hearing loss. At the same time, interactions must be considered between endogenous dysfunctions of the hair cells and their sensitivity to overload by severe noise. On the other hand, the diagnosis of NIHL is not valid when there were uncertainties with respect to the type of hearing dysfunction or the risk of noise at the place of work. These difficulties also apply to the estimation of the individual disability from NIHL when associated with other types of hearing loss.

Speech recognition in the elderly.

The acuity of hearing and speech recognition has been checked in two groups of elderly persons: 1) Subjects aged between 50 and 80 years without any ear disease or hearing problems; 2) Subjects of similar age with noise-induced permanent hearing loss (NIPHL). The speech recognition threshold was evaluated in both groups by numbers of second order, and the speech recognition score was evaluated using monosyllables. The elder people in both groups did not show significant deviation from the normal speech recognition threshold. The speech recognition score for monosyllables was worse in both groups, and there was a significantly greater loss of speech recognition in the NIPHL group than in the elderly persons with normal hearing. Like hearing losses in the higher frequencies, speech recognition ability in healthy elderly persons can be regarded as just as much a function of the sum of acoustic traumas within the person's lifetime as a result of cerebral ageing processes. Real speech recognition losses and (in connection with them) problems in understanding speech in common situations are results of disturbances of hearing function resulting from any kind of pathology and not of ageing processes alone.

[Comments on the revision of the Königstein instructional pamphlet]. / Anmerkungen zur Neuauflage des Königsteiner Merkblattes.

The "Königsteiner Merkblatt (juris prudence)" is an instructional booklet of the general association of juris prudence involves accident insurance ("Hauptverband der gewerblichen Berufsgenossenschaften") in Germany. Medico-legal examinations of occupational noise-induced hearing loss are detailed. In contrast to prior editions, the 4th edition of this booklet, published in January 1996, has been extended by the definitions of legal regulations important for the physician in making medical decisions. Also the number of tests recommended for audiological investigation has been extended. The rules for estimating hearing disability and the calculation of individual handicaps have been changed, and the handicaps for complete deafness in one or both ears have been increased to 20% or 80%, respectively. The most important changes and extensions of the new edition are cited and discussed.

[Hearing loss in cardiovascular diseases (author's transl)]. / Schwerhörigkeit bei Herz-Kreislauf-Erkrankungen

For the sensory cells of Corti's organ are high susceptible to deficits in O2-supply, all disturbances of blood-flow in the inner ear can deteriorate the hearing function. It is the hypotonic dysregulation of the microcirculation in the stria vascularis, which is much more dangerous for the inner ear auditory receptors than be hypertonic disease. The occurance of acute or progredient hearing loss with symptoms of a sensorineural leason and of tinnitus therefore can be looked as an indication to the beginning of a cardiovascular disease, and necessitates appropriate diagnostic and therapy.

[Applied nystagmometry in differentiating vesitbular diseases (author's transl)]. / Die Verwendung des Nystagmometers bei der Differentialdiagnose vestibulärer Erkrangkungen

Nystagmus as a reaction on vestibular stimulation is influenced by many factors which are difficult to control. One of the most important parameters correlating best with the excitability of the peripheral vestibular apparatus is the speed of the slow phase of the nystagmus. This can be registered directly by use of the nystagmometer (or Blauert System), together with the speed of the fast phase. All parameters of the nystagmus can be easily described when recorded. However, an exact description of the nystagmic reaction should not be considered as a complete diagnosis by itself alone; the diagnosis can only be the result of combining nystagmometry, audiometry and other otoneurological or neurological findings with the patient's presenting complaints (or history of the disease involved).

[Early diagnosis and therapy of hearing damage in children in the first months of life]. / Frühdiagnostik und Therapie von Hörschäden bei Kindern in den ersten Lebensmonaten.

Recent research on acoustical deprivation shows that anatomical and functional maturation of the hearing pathways is dependent on the reception and perception of specific stimuli. In cases of dysfunction of the peripheral hearing organ, a secondary dysfunction of perception and apperception of acoustical signals develops. The experiences of paedagogues for hard hearing children confirm that the results of their special education are the better the earlier they begin. Therefore, children with congenital deafness must be evaluated by newborn screening to have a chance of initiation of therapy as early as possible, that is, within the first few months of life.

[The degree of disability in cases of small noise induced hearing losses (author's transl)]. / Die MDE-Bewertung bei geringgradiger Lärmschwerhörigkeit.

For calculation of the degree of disability in cases of small noise induced hearing losses, Lehnhardt has developed a table which divides the range of small hearing losses into two groups with 0% and 10% respectively, and makes it possible to pick up the degree of disability directly by use of the audiometrical data from tone and speech audiometry. A comparison between the degrees of disability picked up from this table and those, which are received from the table of Boenninghaus and Röser using only the results of speech audiometry, shows that the table of Lehnhardt in more cases yields a degree of 10% disability than the table of Boenninghaus and Röser. In the range of beginning to severe hearing loss both tables give results which statistically are not different. In cases of noise induced hearing loss in combination with other causes of hearing disability, where the low frequencies also have severe hearing loss, the table of Lehnhardt enables one to calculate the noise induced part of the whole hearing loss against another kind of hearing defect.