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Biomedical subjects

T Becker

Publications and source records attributed to T Becker.

At least 109 records · Page 6Linked to original sources

Cerebellar arachnoid cyst in a firesetter: the weight of organic lesions in arson.

A 52-year-old female patient was accused of arson; the patient had had an arachnoid cyst of the cerebellar vermis. Even after surgery, she showed marked instability of mood and pseudologia fantastica, but did not suffer from cognitive impairment. Possible associations of the presence of this cerebellar arachnoid cyst and behavioral disturbances are discussed.

Arachnoid Cysts↗

Association of anophthalmia and esophageal atresia.

We report on a boy and a girl with bilateral anophthalmia and proximal esophageal atresia. In addition to vestigial optic nerves and chiasma, MRI studies showed other central nervous system abnormalities; one had ectopic tissue in the hypothalamic region, and the other hand generalized ventriculomegaly associated with atrophy. Two other cases, both males, have been reported with anophthalmia and esophageal atresia as their only malformations. These 4 cases are reviewed in light of recent advances in the understanding of ocular embryogenesis and of the midbrain as a development field. Concurrence of these defects appears to be non-random.

Anophthalmos↗

Immunohistological localization of tenascin-C in the developing and regenerating retinotectal system of two amphibian species.

The expression pattern of the extracellular matrix molecule tenascin-C was investigated in the retinotectal system of the frog Discoglossus pictus and the salamander Pleurodeles waltl during development and optic nerve regeneration in the adult. In both species, the retina was devoid of tenascin-C immunoreactivity at all ages studied. During development, tenascin-C was distributed in a gradient in the optic nerve, with the highest immunoreactivity in the eye near part of the optic nerve. The myelin-associated glycoprotein was distributed in a gradient with opposite polarity. In Discoglossus, but not Pleurodeles, tenascin-C was detected in the anterior chiasm. In the tectum of both species, tenascin-C was observed in deep cellular and fiber layers but not in the layers receiving optic fibers or proliferative zones. The distribution patterns of tenascin-C were the same during development and in the adult, except for a disappearance of the molecule from the intraocular part of the optic nerve. After lesioning the optic nerve of adult animals, tenascin-C was strongly reexpressed in the intraocular part of the optic nerve but was only weakly upregulated in the distal optic nerve stump. In contrast, a chondroitin sulfate epitope was strongly upregulated in the distal optic nerve stump. These observations suggest that during development, tenascin-C serves as an attenuating barrier for myelinating cells in the optic nerve and contributes to the guidance of growing retinal ganglion cell axons. Due to its sustained expression in the adult, tenascin-C may have similar functions during regeneration of the lesioned adult retinotectal system.

Animals↗

Reduced echogenicity of brainstem raphe specific to unipolar depression: a transcranial color-coded real-time sonography study.

Echogenicity of the brainstem raphe was assessed in patients with major depression, bipolar affective disorders, and schizophrenia and compared with healthy adults employing transcranial color-coded real-time sonography. Forty probands were enrolled in each group. A highly significant reduction in raphe echogenicity was detected only in patients suffering from major depression. Echogenicity of the raphe was independent of age or sex and did not correlate with severity of the depressive syndrome or patient state. These findings are suggestive of structural desintegration of the brainstem raphe in unipolar depression, an anatomical region assumed to be a biological focus in the pathogenesis of depressive syndromes.

Adult↗

D- and L-lactate determination in dairy products: presentation of a fast automated analysis system.

A flow-injection system is presented, which is versatile, automated and has an integrated enzyme system. Its efficiency at determining D- and L-lactate separately in dairy products is compared with the officially used reference method (DIN 10335). By means of a mathematical elimination of matrix effects, the pretreatment steps can be clearly reduced. As a result of the immobilization of the enzymes, an appropriate automation software and an adaptation of the system developed to the given medium, the analysis could be performed within 5 min and was distinctly cheaper than alternative methods. The values determined in 15 different dairy products deviated from those of the reference method by 3% at a maximum.

Animals↗

Some methodological issues in neuroradiological research in psychiatry.

An outline is given of some of the methodological issues discussed in neuroradiological research on psychiatric illness. Strengths and shortcomings of magnetic resonance imaging (MRI) in depicting and quantifying brain structures are described. Temporal lobe anatomy and pathology are easily accessible to MRI, whereas limits on anatomical delineation hamper approaches to frontal lobe study. White matter hyperintense lesions are sensitively depicted by MRI, but specificity is limited. Distinction of vascular and primary degenerative dementia is considerably improved by CT and MRI analysis. Computed tomography (CT) and MRI have enhanced the understanding of treatable organic psychiatric disorders, e.g., normal pressure hydrocephalus. Subcortical and white matter pathology has been replicated in CT and MRI studies of late-onset psychiatric disorders, clinical overlap with cerebrovascular disease or neurodegeneration may be of import. Transcranial sonography findings of brainstem structural change specific to unipolar depression may contribute to the understanding of affective psychoses. Magnetic resonance spectroscopy and functional MRI are likely to stimulate psychiatric research in the future.

Brain↗

Disturbances of cerebrospinal fluid (CSF) circulation--neuropsychiatric symptoms and neuroradiological contribution.

The present study aimed at relating dementia, pseudo-neurasthenic and affective organic brain syndromes to underlying type of CSF flow disorder and to subsequent alteration of anatomy. T2*-weighted magnetic resonance imaging (MRI) in the midsagittal plane permitted an analysis of aqueductal CSF flow phenomena and hydrocephalus-induced elevation, thinning and dorsal impingement of the corpus callosum. Furthermore, the width of the third ventricle was measured on the transverse scout images. 72 patients with communicating hydrocephalus (increased aqueductal CSF pulsations) and 26 patients with aqueductal stenosis (absence of aqueductal flow phenomena) were compared with 22 controls. Dementia and affective disorders were distributed equally among both CSF flow subgroups whereas pseudo-neurasthenic syndromes were observed more frequently in non-communicating hydrocephalus (p < 0.03). Alzheimer-type and multiinfarct dementia syndromes were found more frequently in communicating hydrocephalus whereas non-classifiable dementia showed some predilection for non-communicating hydrocephalus. Callosal height, area and third ventricular width did not predict affective or pseudoneurasthenic disorder whereas third ventricular width (p < 0.01) and callosal area (p < 0.05) discriminated between demented and non-demented patients. Dorsal impingement of the corpus callosum by the falx was a non-specific finding.

Cerebral Aqueduct↗

Larger topographical variance and decreased duration of brain electric microstates in depression.

The topographical configuration of the spontaneous brain electric fields is considered to contain relevant information about the pattern of the generating cortical electrochemical activation and the associated cognitive processes. Space oriented segmentation allows to break down the stream of the spontaneous EEG into brain electric microstates with stable configuration of the fields. It has been shown that the mean duration of the microstates was consistent with the duration of elementary steps of cognitive processes, and that different topographies of the microstates are associated with different cognitive modalities. Space-oriented segmentation was applied to the resting EEG of 22 depressive patients and of 22 controls. The topographical variance was larger, and the most prominent brain electrical microstates of the EEG epochs were significantly shorter in the depressive group than in controls. No differences were found for the shortest microstates. This result cannot be explained by group differences in the frequency domain of the EEG. No topographical differences were found between the microstates of depressives and those of controls. Based on previous results in healthy volunteers during spontaneous cognition and in schizophrenic patients, the findings indicate that formal aspects rather than the modalities of the stream of cognition are altered in depression. Automatic and schematic processing, and attentional deficits as described in depressive patients might account for the finding of less sustained brain electrical microstates.

Adult↗

The corpus callosum in communicating and noncommunicating hydrocephalus.

To investigate morphological changes in the corpus callosum in hydrocephalus and to correlate them with clinical findings we studied sagittal T2*-weighted cine MR images of 163 patients with hydrocephalus. The height, length and cross-sectional area of the corpus callosum were measured and related to the type of cerebrospinal fluid flow anomaly and to clinical features, especially dementia. With expansion of the lateral ventricles the corpus callosum showed mainly elevation of its body and, to a lesser degree, increase in length. Upward bowing was more pronounced in noncommunicating than in communicating hydrocephalus. Dorsal impingement on the corpus callosum by the free edge of the falx correlated with the height of the corpus callosum. Cross-sectional area did not correlate with either height, length or impingement; it was, however, the strongest anatomical discriminator between demented and nondemented patients. The area of the corpus callosum was significantly smaller in patients with white matter disease. Our findings suggest that, due to its plasticity, the corpus callosum can to some degree resist distortion in hydrocephalus. Dementia, although statistically related to atrophy of the corpus callosum, is possibly more directly related to white matter disease.

Case-Control Studies↗

Correlation of cerebral blood flow and MCA flow velocity measured in healthy volunteers during acetazolamide and CO2 stimulation.

The assessment of the cerebrovascular reserve capacity (RC) has become a widely used tool in the management of cerebrovascular disease. Discrepancies become obvious, however, if results obtained with different methods are compared. Aim of the present study, therefore, was to compare blood velocity and cerebral perfusion data in the same group of healthy test persons. In 32 volunteers regional cerebral blood flow (rCBF) was measured with the 133Xe-inhalation method. F1 as grey matter flow and the initial slope index (ISI) were computed. Simultaneously flow velocity in the middle cerebral artery (VMCA) was assessed by transcranial Doppler sonography (TCD). Measurements were performed in the resting state, during inhalation of 7% CO2 and after 1 g acetazolamide. Baseline VMCA was 62.38 +/- 16.1 cm/s, 90.84 +/- 23.85 cm/s during hypercapnia and 84.91 +/- 24.54 cm/s after acetazolamide. There was no significant change of baseline or stimulated values with age. F1 rose from baseline 76.25 +/- 12.48 ml/100 g/min to 103.90 +/- 14.6 ml/100 g/min in hypercapnia and to 98.4 +/- 14.9 ml/100 g/min after acetazolamide. The baseline F1 values and the response to CO2 decreased with age (p = 0.01) whereas for the acetazolamide reaction an age dependency could not be proven. ISI baseline values (41.5 +/- 6.1 ml/100 g/min) as well as those found after CO2 or acetazolamide decreased significantly with age. In hypercapnia changes of F1 and ISI were not too well related with changes of VMCA (F1: r = 0.599; ISI: r = 0.473), but better during acetazolamide exposure (F1: r4 = 0.715; ISI: r = 0.522). The age dependency of resting and stimulated values has to be considered when assessing the reserve capacity. There is a correlation between changes of the perfusion and flow parameters in healthy individuals which, however, may be worse in cerebrovascular disease.

Acetazolamide↗

Lilliputian and negative hallucinations in a patient with probable encephalomyelitis disseminata.

A patient who showed Lilliputian hallucinations and negative hallucinations in the course of probable disseminated encephalomyelitis is described. At the age of 14 years the patient experienced a transient, flaccid paresis of the right leg. Eighteen years later she suddenly developed paranoid-hallucinatory symptoms accompanied by atypical visual hallucinations. She did not recover completely and until now she has suffered at least once every year from an episode with psychotic symptoms. During the most recent of these episodes, MRI revealed several disseminated supra- and infratentorial foci in the brain. Two of them, in the left cerebral peduncle and in the left occipital white matter are discussed as the cause of her visual hallucinatory symptoms.

Adult↗

Target-induced neurogenesis in the leech CNS involves efferent projections to the target.

During a critical period in leech embryogenesis, the sex nerves that connect the 5th and 6th midbody ganglia (MG5 and MG6) to the primordium of the male sexual organ carry a spatially localized signal that induces the birth of several hundred neurons specific to these ganglia. We examined particular cellular elements (afferents, efferents, non-neuronal components) within these nerves as potential conveyors of the inductive signal. We show that axons of peripheral sensory neurons in the male genitalia travel along the sex nerves and into MG5 and MG6, but reach the CNS after the critical period has elapsed and cannot, therefore, be involved in the induction. Of the six sex nerves, four contain non-neuronal cells that span the entire distance between the male genitalia and the sex ganglia. However, when male genitalia were transplanted to ectopic locations close to MG6, induction occurred frequently but only in MG6, mediated by ectopic nerves that do not contain these cells. Thus, non-neuronal cells specific to the normal sex nerves are not necessary for induction. In addition, dye injections into the target during the critical period failed to reveal migrating cells in the sex nerves that could convey the inductive signal to the CNS. Finally, we show that 11 pairs of central neurons in each ganglion project to the male organ early during the critical period. In the adult, at least 3 additional pairs of neurons in MG6 also innervate this target. We conclude that the only components of the sex nerves that connect the sex ganglia to the target during the critical period that could be associated with induced central mitogenesis are the axons of central neurons that innervate the male genitalia.

Animals↗

Omeprazole/amoxicillin versus triple therapy for Helicobacter pylori in duodenal ulcer disease: two-year follow-up of a prospective randomized study.

The present study was designed to compare the efficacy and tolerability of triple therapy and dual therapy for Helicobacter pylori in duodenal ulcer patients and to evaluate the long-term clinical course of ulcer disease. Forty duodenal ulcer patients with proven H. pylori infection were enrolled into the study and randomly treated with either triple therapy consisting of bismuth subsalicylate, metronidazole and tetracycline plus ranitidine or with dual therapy comprising omeprazole and amoxicillin. Patients were investigated clinically and endoscopically including assessment of H. pylori infection by means or rapid urease test, culture, histology and urea breath testing 4 weeks after cessation of eradication therapy, in 1-year intervals and when dyspeptic symptoms recurred. One patient of each group was lost during follow-up. H. pylori infection was cured by triple therapy in 84.2% and by dual therapy in 78.9% (p = 1.00). During follow-up, all patients with cure of H. pylori infection (n = 31) remained in stable remission with respect to duodenal ulcer disease, while 6 out of 7 patients persistently infected with H. pylori developed an ulcer relapse (p < 0.001). One patient with cured infection had had an episode of dyspeptic symptoms requiring pharmacotherapy and in another 3 patients mild refluxesophagitis without necessity of medical treatment had been detected on the occasion of a scheduled endoscopy. In the short-term, cure of the infection resulted in a marked reduction of the degree of antral gastritis and in a loss of activity in all but one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Short-term triple therapy with pantoprazole, clarithromycin and metronidazole in eradication of Helicobacter pylori].

In a prospective study, thirty consecutive patients presenting with either H.pylori positive (histology and/or culture) ulcer disease (n = 17; acute ulcer: n = 11) or functional dyspepsia (n = 13) were treated over one week with pantoprazole 40 mg bd, clarithromycin 250 mg bd and metronidazole 400 mg bd. Four weeks after discontinuation of the study medication H.pylori eradication was assessed by means of an urease test, culture and histology. One patient had to be withdrawn from the study after one day because of a concomitant infectious disease requiring long-term antibiotic treatment. Another patient refused the final follow-up endoscopy. 28 patients completed the study without contravening the protocol. H.pylori infection was eradicated in 24 out of 28 patients (eradication rate: 86%; 95%-confidence interval: 57%-96%). Cure of bacterial infection was more frequently obtained in ulcer patients as compared to patients suffering from functional dyspepsia (94% vs 75%; p = 0.28). In 2 patients, treatment failure was associated with pretherapeutic resistance of H. pylori to either clarithromycin or metronidazole. Without antiulcer treatment beyond eradication therapy, ulcer healing was endoscopically confirmed after 5 weeks in 9 out of 10 patients available for follow-up (healing rate: 90%; 95%-confidence interval: 56%-100%). Seven patients reported mild adverse events that did not lead to discontinuation of the study medication (rate: 23%; 95%-confidence interval: 10%-42%). After cure of the infection, histology demonstrated a statistically highly significant improvement (p < 0.001) of both grade and activity of antrum and body gastritis.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Pyridinylmethylsulfinylbenzimidazoles↗

[Zolpidem dependence and depression in the elderly].

In a 75 years-old patient with chronic senile depression criteria of zolpidem dependency were fulfilled. There was no history of benzodiazepine or alcohol abuse. Positive psychotropic effects were emphasized by the patient who spread intake over the day.

Aged↗

[Closure of large psychiatric hospitals in England: evaluation by the TAPS project--a review of the literature].

The TAPS study evaluates the closure of two Greater London mental hospitals. Beginning in 1985, one-year and five-year follow-up compared successive cohorts of long-stay patients discharged to the community (leavers) with groups of matched long-stay patients who stayed in hospital. Some psychopathological symptoms improved in discharged patients, some did not. Mortality, patient vagrancy and delinquent behaviour did not increase in leavers. Patient autonomy, social networks and patient satisfaction favoured out-patient provision of care as compared to continuing in-patient care.

Community Mental Health Services↗

[The status of transcranial color-coded real time ultrasound in diagnosis of cerebral lesions].

Transcranial color-coded real-time sonography (TCCS) combines transcranial Doppler sonography and color-coded B-mode scanning of the brain parenchyma and cerebral vessels. This technique is not invasive and a broad spectrum of intracerebral lesions such as vascular lesions (ischemic stroke and intracerebral hemorrhage, aneurysms, arteriovenous malformations, arteriosclerotic vascular degeneration) and parenchymal lesions (brain tumors, degenerative and neuropsychiatric disorders) can be disclosed. Compared with MRI and CT, the ultrasound system is movable. Thus, it can be used easily in emergency rooms and intensive care units. In addition, TCCS can disclose new insights into the pathophysiology of disorders of the CNS, as in neuropsychiatric diseases. Ultrasound contrast agents improve the depiction of intracranial vessels. The pathology of the venous system can be identified.

Adult↗