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Biomedical subjects

R Brinkmann

Publications and source records attributed to R Brinkmann.

16 recordsLinked to original sources
PubMed1992

Human immunodeficiency virus infection in microglia: correlation between cells infected in the brain and cells cultured from infectious brain tissue.

In acquired immunodeficiency syndrome, the lesions of the central nervous system in association with the human immunodeficiency virus are thought to be related to an infection of microglia, although no studies are available in which cultured and physiological characteristics of microglia cells infected in vivo have been examined. In this report, we used brain tissue from a child dying of human immunodeficiency virus infection and show that microglia cells were the main cell population being infected. Moreover, isolated macrophage-like cells from fresh brain material revealed a close resemblance to peripheral blood macrophages in their content of surface and intracellular antigens. No virus particles or viral antigens were produced by these cells during the first week of cultivation. Productive infection was readily apparent, however, by day 30. This finding illustrates the slow nature of the virus life cycle in these cells and the minimal cytopathology that accompanied the infection.

Brain↗
PubMed1992

HIV-1 gp120 receptor on CD4-negative brain cells activates a tyrosine kinase.

Human immunodeficiency virus (HIV-1) infection in the human brain leads to characteristic neuropathological changes, which may result indirectly from interactions of the envelope glycoprotein gp120 with neurons and/or glial cells. We therefore investigated the binding of recombinant gp120 (rgp120) to human neural cells and its effect on intracellular signalling. Here we present evidence that rgp120, besides binding to galactocerebroside or galactosyl-sulfatide, specifically binds to a protein receptor of a relative molecular mass of approximately 180,000 Da (180 kDa) present on the CD4-negative glioma cells D-54, but not on Molt4 T lymphocytes. Binding of rgp120 to this receptor rapidly induced a tyrosine-specific protein kinase activity leading to tyrosine phosphorylation of 130- and 115-kDa proteins. The concentration of intracellular calcium was not affected by rgp120 in these cells. Our data suggest a novel signal transducing HIV-1 gp120 receptor on CD4-negative glial cells, which may contribute to the neuropathological changes observed in HIV-1-infected brains.

Brain↗
PubMed1991

Interspersion of fragmented fiber's splinters into tissue during pulsed alexandrite laser lithotripsy.

Laser induced shockwave lithotripsy (LISL) on artificially inserted human renal calculi was realized in explanted pig ureters. A pulse stretched Alexandrite solid state laser was used at 750nm. Pulses of 350ns and 1 microseconds duration were transmitted through a 250 microns all silica fiber onto a stone surface, keeping the fiber tip in contact with a stone close to the ureter wall. The high power density of the 350 ns pulses lead to an optical breakdown inside the distal fiber tip causing fiber fragmentation of about 28 mm/100 pulses. Deep penetration of the fiber fragments into the ureter wall was proven histologically. Fiber fragmentation was avoided by increasing the pulse duration up to 1 microseconds. Riks for patient treatment caused by short pulse lithotripsy are discussed.

Animals↗
PubMed1987

Inducibility of Ia antigen on astrocytes by murine coronavirus JHM is rat strain dependent.

Inducibility of Ia molecules on cultivated astrocytes by JHM virus correlates with demyelinating disease susceptibility of animals from which these astrocytes are derived. On the contrary, class I induction of both astrocytes and oligodendrocytes occurs as a consequence of normal cultivation procedures in both susceptible and resistant strains. Increased expression of class I antigens on rat astrocytes and oligodendrocytes is not related to JHM viral infection as it is in the mouse. These data indicate that strain differences in Ia inducibility, rather than inducibility of class I antigens, by JHM virus may explain higher levels of T cell-mediated damage to myelin during infection in susceptible rat strains compared with resistant strains.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1979

The course of brain atrophy in Parkinson's disease.

In 110 parkinsonian patients (53 men, 57 woman) aged 38--81 years, computer-tomographic follow-up investigations were done to assess the development of brain atrophy. The control examinations were done after an average of 28 months. At that time an increase in brain atrophic changes of different localization could be observed in 23% of the patients. In addition, it could be demonstrated that the increase in pathologic CT findings is to be observed especially in patients with higher age, a more marked impairment in psycho-organic capacity, more pronounced handicaps in the fine-motorial performances at the beginning of the study. From the neuroradiological point of view, patients with more marked pathologic CT findings upon the first examination, be these ventricular enlargement and/or cortical atrophy, more often showed a progression of brain atrophy.

Adult↗
PubMed1978

Association and dissociation of visual functions in a case of bilateral occipital lobe infarction.

A severe restriction of the visual field was observed in a patient suffering a bilateral occipital lobe infarction. Soon after the lesion, the visual field had an angle of approx. 4 degrees. Some recovery was observed within the following months. Within the restricted visual field, several visual functions were tested. Increment threshold, for instance, was found to be one log unit higher than would normally be expected. Color vision was completely lost soon after the lesion, but some recovery was later observed. Although binocular interaction was demonstrated by the interocular transfer of after-effects, the patient never experienced steropsis. He also seemed unable to recognize faces. Dsepite the small visual field, optokinetic nystagmus could be elicited. A notable slowing down of visual analyses was observed in experiments on visual reaction time, on the inversion of the Necker cube, and on binocular rivalry. The complete loss of certain functions like steropsis or face recognition in contrast to a quantitative reduction of other functions like visual acuity or color perception can be discussed in the light of two conceptual models of perceptual processing. One model suggests the representation of different visual functions within one neuronal network, each function represented by a different number of neurons or a different algorithm within the network. The second model suggests a spatial segregation of different visual functions in different cortical areas that receive input from one common structure, presumably the striate cortex.

Aged↗
PubMed1977

[Behavioral rehabilitation of nonspecific symptoms occuring after craniocerbral trauma (author's transl)].

The purpose of this study was to develop a behavioral rehabilitation program for patients with long-term nonspecific symptoms following craniocerebral trauma. In 47 patients we analyzed symptoms typical of "illness behavior" (e.g. complaining tendency, depression, irritability, psychosomatic pain, problems in job performance and social interaction) as possible targets for behavior modification. We then developed a behavioral training program to teach the patients various techniques of self-control (relaxation, desensitization, self-image training, analysis and control of illness behavior, assertiveness, performance techniques), our program being based on studies in the U.S.A. using similar approaches. For a preliminary testing two groups of 8 and 6 patients each were treated by different therapists. The patients worked through a section of the program manual prior to each group session. During the sessions proper (a total of 8 weekly two-hour sessions) the different techniques were practiced under the therapist's supervistion. In both groups a significant reduction in illness behavior as indicated on questionnaires and in 3-month follow-up was found. These encouraging results need to be further substantiated by controlled outcome studies.

Adult↗
PubMed1976

The Munich Coma Scle (MCS).

The level of coma can be measured by the assessment of changes of behaviour after different intensities of stimulation. Two additive scales (Guttman scales) for susceptibility to stimulation and reactivity were developed, constituting the Munich Coma Scale (MCS). The findings of previous investigations were repeated in a new sample of 67 comatose patients. Implications of the additivity of reactivity are discussed and related to the concept of 'behavioural arousal' advanced in the recent literature.

Adult↗
PubMed1975

[Quantitative clinical assessment of the course in a case of temporal encephalitis (author's transl)].

The neuropsychiatric symptoms and signs of a case of sporadic encephalitis are presented. Psychopathological features are assessed with the IMPS (Lorr-scale). This is shown to be useful for objectivation and differentiation of the psychopathological syndrome. A disadvantage of the IMPS is the limited applicability in states with disturbed verbal communication and insufficient recording of mnestic impairment. Of the 4 states of activation defined for patterns of horizontal and vertical EOG and EMG recordings, state 2 (i.e., electrical activity of the mentalis-EMG, no blinks, no rapid lateral eye movements) and state 4 (i.e., rapid lateral eye movements, electrical activation of the mentalis-EMG) are appropriate measures for a quantitative description of the course of the disease. The relative distribution of state 2 and 4 within one period of registration indicates that the decrease of state 2 and the increase of state 4 are highly correlated with the reduction of psychopathological symptoms. Furthermore, transition among states shows the same correlation during the course of the disease. The ratio of the total number of transitions and non-transitions within one period of registration is proportional to the alleviation of clinical signs.

Adult↗
PubMed1975

[Measurement of attention deficit in the course of intoxications (author's transl)].

The level and course of attention was measured hourly in 9 drug intoxicated patients after a suicide attempt over periods which varied between 12 and 72 hrs. Attention was measured by the use of two additive 5 step scales for susceptibility to stimulation and reactivity, which were developed by the authors in earlier investigations and proven to be very reliable. Although, the original data set of attention measures was different among the patients, some common features could be elaborated: 1. The level of attention varies very little within 1 hr. Differences greater than one step on the scales were rarely observed between two measurements. 2. The mean course of recovery from attention deficit is linear throughout the scales while the variance is substantial at each step of the scales. For quantification of attention deficit a measure was defined which gives the relation between the actual deficit and full attention. Since the correlation between both scales is high over the whole observation period, it was concluded that the intoxication alters the level but not the structure of attention.

Acoustic Stimulation↗
PubMed1975

[Scaling of disturbances of attention in neurological patients (author's transl)].

In a previous report two additive scales were developed for measuring susceptibility to stimulation (with 4 experimental stimuli) and reactivity (with 4 types of reactions). The degree of loss of attention in neurological patients as determined by the position of a patient correlates with the frequencies of his reactions. Thus the measurement of frequencies does not add any further information. There is no patterning of reactions due to the different etiology of the disorder of attention. These results support the suggested one-factor theory of attention.

Adolescent↗
PubMed1975

[Development of an apparatus for measuring attention in patients with cerebral damage and functional disorders].

58 patients with various underlying neurological diseases, who had an impairment of attention, were examined. 12 patients without clinically evident disorders of attention were examined as a control group. The aim of the study was the development of a standardized procedure for the assessment of impaired attention. An additive, 4 step scale of the "susceptibility to stimulation" (Guttman scale) was constructed out of several, heterogeneous stimuli. In addition, an additive 4 step scale of "reactivity" was constructed out of a catalogue of defined reactions. The two scales permitted the assessment of reactivity and susceptibility to stimulation, the degree of which could be demonstrated as being proportional to one another. The transformation of susceptibility to stimulation into reactivity is thought to be performed by an internal system which is attributed to attention.

Acoustic Stimulation↗
PubMedDate not supplied

[Shortening diclofenac therapy by B vitamins. Results of a randomized double-blind study, diclofenac 50 mg versus diclofenac 50 mg plus B vitamins, in painful spinal diseases with degenerative changes].

The use of nonsteroidal anti-inflammatory drugs (NSAID) such as diclofenac for treatment of degenerative rheumatic disorders of the lumbar spine is of great significance in orthopedic practice. Clinical studies have shown that concomitant treatment with vitamins B1, B6, B12 and diclofenac provides more efficient pain relief than treatment using diclofenac alone. This study was undertaken in order to determine whether the duration of treatment with diclofenac for lower back pain can be shortened by adding B-vitamins to the therapeutic regimen. From September through December of 1986, 256 patients participated in a multicenter, controlled, randomized double-blind trial which compared the clinical efficacy of diclofenac (50 mg) with a combined therapy of diclofenac (50 mg) and vitamins B1, B6, and B12 (thiamine nitrate, pyridoxine hydrochloride, and cyanocobalamine, resp.; in dosages of 50 mg, 50 mg, and 0.25 mg, resp.). Patients were treated with 3 X 1 capsule daily for a maximum of two weeks, having the option to terminate participation in the trial after 1 week in the event of total pain relief. The data of 238 patients were able to be included in the evaluation. 29 patients opted to discontinue therapy due to remission on symptoms. Nineteen (65.6%) of these patients belonged to the combined therapy group, the other 10 (34.4%) having taken diclofenac alone; this difference is statistically significant (p less than 0.05). An important aspect in the evaluation of therapy was the patient response regarding the improvement of painful symptoms which, in addition to their subjective feedback, was reflected in the test results of the "Hoppe Pain Questionnaire (HPQ)." All parameters used as a measure of pain relief indicated superior results with the B-vitamin supplemented therapy when compared with results obtained with diclofenac alone. Moreover, after 3 days of therapy the "sensory" pain factor "sharpness" improved significantly. Undesirable side-effects were documented with 39 patients, 14 of them having discontinued therapy for this reason. No statistically significant difference could be determined within this group with regard to therapy. The study results document the positive influence of B-vitamins on painful symptoms and indicate that less NSAID is needed for pain relief when combined with B-vitamins.

Clinical Trials as Topic↗