Selective condensation of DNA by aminoglycoside antibiotics.

The condensing effect of aminoglycoside antibiotics on the structure of double-stranded DNA was examined. The selective condensation of DNA by small molecules is an interesting approach in biotechnology. Here, we present the interaction between calf thymus DNA and three types of antibiotic molecules: tobramycin, kanamycin, and neomycin. Several techniques were applied to study this effect. Atomic force microscopy, transmission electron microscopy images, and nuclear magnetic resonance spectra showed that the interaction of tobramycin with double-stranded DNA caused the rod, toroid, and sphere formation and very strong condensation of DNA strands, which was not observed in the case of other aminoglycosides used in the experiment. Studies on the mechanisms by which small molecules interact with DNA are important in understanding their functioning in cells, in designing new and efficient drugs, or in minimizing their adverse side effects. Specific interactions between tobramycin and DNA double helix was modeled using molecular dynamics simulations. Simulation study shows the aminoglycoside specificity to bend DNA double helix, shedding light on the origins of toroid formation. This phenomenon may lighten the ototoxicity or nephrotoxicity issues, but also other adverse reactions of aminoglycoside antibiotics in the human body.

Are there any disturbances in vestibular organ of children and young adults with Type I diabetes?

AIMS/HYPOTHESIS: The aim of the work was to evaluate the vestibular organ condition in children and young adults suffering from Type I (insulin-dependent) diabetes mellitus. METHODS: The group examined consisted of 95 children and young adults aged from 6 to 28 years with Type I diabetes diagnosed. The diabetic group was divided into subgroups according to duration of the disease, compensation of the disease, and presence and character of hypoglycaemic incidents, and presence of diabetic complications. The control group consisted of 44 healthy children and young adults aged 6 to 28 years. After collecting detailed medical history in each case an electronystagmographic test was performed using the computed two-canal electronystagmographer. RESULTS: Within the diabetic group 6 patients complained about vertigo and balance disorders. Spontaneous nystagmus occurred in 10 cases, positional one in 21 cases. Impaired optokinesis occurred in 36 cases and impaired eye tracking test in 33 cases. In caloric tests there was partial canal paresis in 4 cases and directional preponderance in 7 cases. CONCLUSION/INTERPRETATION: Metabolic disturbances present in Type I diabetes cause disturbances in different parts of vestibular organ but mostly in its central part. Comparing disturbances in the vestibular organ with clinical and biochemical parameters characterising diabetes, the range of vestibular organ impairment in diabetes mellitus type 1 seems to depend mainly on the presence and character of hypoglycaemic incidents and the duration of the disease and to some extent on the compensation of diabetes.

Molecular determinants of complex formation between Clp/Hsp100 ATPases and the ClpP peptidase.

The Clp/Hsp100 ATPases are hexameric protein machines that catalyze the unfolding, disassembly and disaggregation of specific protein substrates in bacteria, plants and animals. Many family members also interact with peptidases to form ATP-dependent proteases. In Escherichia coli, for instance, the ClpXP protease is assembled from the ClpX ATPase and the ClpP peptidase. Here, we have used multiple sequence alignments to identify a tripeptide 'IGF' in E. coli ClpX that is essential for ClpP recognition. Mutations in this IGF sequence, which appears to be part of a surface loop, disrupt ClpXP complex formation and prevent protease function but have no effect on other ClpX activities. Homologous tripeptides are found only in a subset of Clp/Hsp100 ATPases and are a good predictor of family members that have a ClpP partner. Mapping of the IGF loop onto a homolog of known structure suggests a model for ClpX-ClpP docking.

[Chemodectoma: tympanic tumor]. / Chemodectoma--postac pierwotnie bebenkowa.

Glomus tympanicum tumors are the most common benign tumors of middle ear. Initially the leading symptoms are hearing loss and tinnitus. Other complications such as facial nerve paresis reflect deeper structures involvement. Sometimes the disease is masked by chronic pyogenic otitis media. It delays the diagnosis what we observed in one of three cases of chemodectoma presented. We present 3 cases of glomus tumor tympanicus that occurred in three women aged 60-68 years by the time of diagnosis. Localisation, size of the tumor and relation to other structures of the ear was made on the basis of computer tomography. The patients were operated (atticoantrotomy). In one of the cases there was recidivation of the disease two years after operation, we have made reoperation with hearing improvement. All the three patients were cured in outpatient before the correct diagnosis for a few years, they all presented typical symptoms together with typical changes in tympanic membrane. It is important to stress, that chronic pyogenic otitis media which first occurred as the patient was over fifty should arouse suspicion of neoplastic disease.

[A rare case of metastatic meningitis with unknown primary focus and atypical symptoms]. / Rzadki przypadek przerzutowego zapalenia opon mózgowo-rdzeniowych z nieznanego ogniska pierwotnego o nietypowych objawach.

We have presented the diagnostic difficulties in the case of woman aged 59 who was admitted to the clinic with the suspicion of neurinoma of acoustic nerve. The patient was admitted to hospital with peripheral facial nerve paresis on the left side together with sudden surdity and peripheral vestibular impairment. Surdity of the other side occurred after two months. In terminal phase of the disease there was aseptic meningitis. Posthumous diagnosis was made on the basis of neuropathological examination of the brain. It was carcinomatous meningitis. But there was no primary focus found during autopsy. It is important to stress that CT and MRI was completely useless in this case. However pathological brain stem response together with lack of stapedial muscle reflex were much ahead of surdity and other central symptoms. We found only one case of carcinomatous meningitis with unknown primary focus in the literature. The course of the disease is very insidious and in every suspicious cases one should be aware of cancer of unknown primary site.

[Vestibulo-visual interaction in peripheral lesion of vestibular organ]. / Wspóldzialanie przedsionkowo-wzrokowe w obwodowym uszkodzeniu narzadu przedsionkowego.

Studies were carried out on 32 persons between 38 and 54 years of age (average 45) with unilateral peripheral lesion function of the vestibular organ (among them 8 persons with complete lack of excitability) and 10 healthy persons between 23 and 42 years of age (average 32). All of the patients were examinated for vestibulo-visual interaction. With the help of electronystagmography, the eye movement was registered after visual stimulation, vestibular stimulation and simultaneous vestibulo-visual stimulation, with impulses evoking nystagmus of direction compatible and incompatible. Movement of black stripes on the white optokinetic screen with the velocity of 15 degrees/s, to the left and to the right, was visual stimulus. Vestibular organ was activated by cold water (30 degrees C), according to the Fitzgerald Hallpike's procedure. Nystagmus reaction was evaluated in the highest intensification on the basis of the mean velocity of the slow faze, amount of nystagmus deflexion, sum of amplitudes, as well as gain. We also took into account compatibility or incompatibility of the nystagmus directions which was induced by the simultaneous of the vestibulo-visual stimulation. It has been stated that the vestibulo-visual interaction in the unilateral peripheral lesion of vestibular organ does not differ in comparison with healthy persons. Besides, simultaneous vestibulo-visual stimulation induced by the impulses incompatible in their direction causes the decrease of the parameters value of the nystagmus in healthy persons and in persons with peripheral lesion of labyrinth. In the case of one-sided fall-out function of the vestibular organ an increase was observed of value gain of optokinetic nystagmus directed at the damaged side.

[Vestibular evoked potentials in people]. / Wywolane potencjaly przedsionkowe u ludzi.

In the article had been presented the structure and functioning of a prototype system for stimulation and registration vestibular evoked potentials, and the first recording of evoked vestibular potentials (VsEPs) in human beings. This system consist of a original stimulator accelerated for the stimulation of vestibular organ, modul registratory VsEPs as well as string elements and synchronizing stimulation with recording. IMB PC 486 is quickly process of investigation with help of standard interface and a original computer programme. Vestibular organ had been evoked by 200 to 500 cyclicly repealed angular decelerations of 4000 degrees/s2. During investigation white noise was used for masking to avoid the evoking of auditory potentials. Seven of the examined healthy persons (including one deaf person whose vestibular organ was not damaged) had registered a response consisting of several waves with vertex positive peaks. The first two waves P1 and P2 with the mean value 2.02 ms and 5.6 ms are most often during in the 10 ms. The registered deaf persons response does not differ from the record of healthy persons.

[Computer system of the electronystagmographic examination. Part III. Comparative results obtained by computer and traditional technology in the examination of the vestibular organ]. / Komputerowy system badan elektronystagmograficznych. Czesc III. Wyniki badan narzadu przedsionkowego w porównaniu z metoda tradycyjna.

The study presents a comparison of the research into results of vestibular organ stimulated with caloric tests which had been simultaneously registered with the help of a computer system of electronystagmographic examination, as well as the traditional electronystagmographic technic. In the case of 32 healthy persons there had been counted by hand average angular velocity of the slow phase caloric nystagmus average level of reduced excitability of labyrinth and direction predominance. It had been defined that those values are comparable to the ones given by the computer. That points to the right chose of the space of time in the climax of nystagmus reaction and a good identification of the phase both slow and fast by the computer system.

[Computer system of electronystagmographic examination. Part I. Measuring equipment and algorithm of ENG test]. / Komputerowy system badan elektronystagmograficznych cz. I. Stanowisko badawcze i algorytm obslugi.

The work presents the computer system created by the author for automatic registration and analysing oculomotor response records evoked by the stimulation of the vestibular organ. The basis elements of the system had been described. It consists of microcomputer IBM PC/XT/AT, measurement and stimulatory apparatus, multimodular controlling and analytical software as well as the algorithm of system management.

[Difficulties with diagnosis of elongated styloid process syndrome]. / Trudnosci diagnostyczne w zespole przedluzonego wyrostka rylcowatego.

Elongated styloid process syndrome courses in the form of the chronic, noncharacteristic ailment of the pain, within facial skeleton and the lasting, noneffective treatment. This study shows (for example three own cases of elongated styloid process syndrome) the difficulty of diagnose in this group, which can course under the form of dysphagia. This study point at the necessity excludes elongated styloid process syndrome in every unexplained pains of craniofacial and cervical, especially that, easy digital palpation near tonsils and spot film (X-ray) of elongated styloid process syndrome allow to put the right diagnose.

[Computer system of electronystagmographic examination. Part II. Analysis of nystagmus]. / Komputerowy system badan elektronystagmograficznych. Czesc II. Metoda analizy oczoplasu.

It is a description of automatic registration and analysing of the eyes movement. In this method had beed applied a test of the eye movement in the limited momentary speed, test of the time taken by the deflection and the test of unanimity in analysing both deflection and direction of the quick phase. The analysis procedure has two stages. In the first stage the signal undergoes an introductory analysis which is aimed at smoothing it out and approximating it a saw-toothed shape. At this stage the computer identifies the phases, direction of nystagmus and deflection which are not real eye deflections. In the second stage the computer makes measurements of nystagmus parameters.

[Tonal audiometry in hearing evaluation with a microcomputer system]. / Audiometria tonalna w mikrokomputerowym systemie badania sluchu.

The own experiences with the computer microsystem for hearing evaluation "Audiocomp" were presented. The air and bone conduction thresholds as well as the others suprathreshold testing were performed by computer. The reproducibility of results were better than in standard audiometry. The influence of the examined person is lowered making the testing more objective.