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Biomedical subjects

D Krell

Publications and source records attributed to D Krell.

At least 19 recordsLinked to original sources
PubMed1999

Tyrosine hydroxylase immunoreactivity in the locus coeruleus is reduced in depressed non-suicidal patients but normal in depressed suicide patients.

Noradrenergic neurons of the locus coeruleus (LC) have been implicated in the neurobiology of depression and suicidal behavior. The current postmortem study determined numbers of noradrenergic neurons by immunostaining the synthesizing enzyme tyrosine hydroxylase in the LC of 12 non-elderly depressed patients with a mood disorder as compared to 12 age- and sex-matched normal controls. Six patients were suicide victims, the other six patients died of natural causes. Non-suicidal patients had fewer neurons immunoreactive for tyrosine hydroxylase (TH-ir) than suicide victims or controls. No difference appeared between the number of TH-ir neurons in suicide patients and controls. Numbers of pigmented LC neurons were equal in patients and controls. The differences of TH-immunoreactivity could neither be attributed to drug influences nor to polarity of depressive disorder (i.e., unipolar/bipolar). Numbers of TH-ir neurons correlated positively with mean doses of tri- or tetracyclic antidepressants. Results of this study suggest a presynaptic noradrenergic deficit of the LC in depressed non-suicidal patients. Indirect evidence is provided that suicide is not related to decreased noradrenergic function and that traditional antidepressants may enhance noradrenergic activity of the LC in depressed patients.

Adult↗
PubMed1999

Unipolar-bipolar dichotomy of mood disorders is supported by noradrenergic brainstem system morphology.

BACKGROUND: The biological basis of unipolar-bipolar dichotomy of mood disorders was investigated in this postmortem study by morphological comparison of the locus coeruleus (LC) as the main source of noradrenergic transmission in the brain. METHODS: Numbers and the rostro-caudal as well as ventro-dorsal distribution of neuromelanin-containing neurones in the LC were determined in brainstem of 12 patients with bipolar disorder (n = 6) or major depression (n = 6), and 12 normal comparison subjects. RESULTS: Bipolar patients had significantly more neurones on both sides of the LC as a whole than patients with major depression. Topographical analysis revealed that this difference was restricted to the rostral two thirds and the dorsal part of the LC, in which bipolar patients showed at least a trend to higher neurone numbers as compared to unipolar patients or to controls. LIMITATIONS: Small case numbers. CONCLUSIONS: Results suggest differences of innervation arising from the LC of bipolar patients as compared to patients with major depression. These first data of brainstem transmitter system morphology in unipolar and bipolar disorder are in line with neuroanatomical studies of other brain regions indicating a biological basis of the unipolar-bipolar dichotomy of mood disorders.

Adult↗
PubMed1999

Reduced volume of limbic system-affiliated basal ganglia in mood disorders: preliminary data from a postmortem study.

Volumes of basal ganglia in postmortem brains of 8 patients with mood disorders and 8 control subjects without neuropsychiatric disorder were determined. Morphometry of serial whole-brain sections under the control of postmortem artifacts revealed reduced volumes of the left nucleus accumbens (-32%, P = 0.01), the right and left external pallidum (-20%, P = 0.04), and the right putamen (-15%, P = 0.04) in the patient group compared with the control group. These results suggest that, in particular, the limbic loop of the basal ganglia involving the nucleus accumbens and the pallidum is affected in mood disorders.

Adult↗
PubMed1998

Morphometric studies of the entorhinal cortex in neuropsychiatric patients and controls: clusters of heterotopically displaced lamina II neurons are not indicative of schizophrenia.

Subtle cytoarchitectural abnormalities of the rostral entorhinal cortex have been reported to be characteristic for schizophrenics. A main finding was the heterotopic displacement of clusters of lamina II neurons (which appeared morphologically immature) into layer III. Recent findings suggesting a considerable cytoarchitectural heterogeneity of the normal entorhinal cortex renewed interest in this problem and prompted the question of the extent to which 'aberrantly' located cell clusters are really disease-related. Being blind to the clinical diagnosis, we analyzed quantitatively the amount of entorhinal heterotopias in schizophrenics (n = 31), controls (n = 45) and depressive patients (n = 7). It was revealed that heterotopic cell clusters occurred in schizophrenics and controls with roughly the same frequency (amount of clusters per section). In depressive, there were significantly more heterotopias than in controls (right hemisphere). Our data show that heterotopias are common to the rostral part of the human entorhinal cortex and are not a suitable neuroanatomical marker of schizophrenia.

Adult↗
PubMed1998

Schizophrenia and anteroventral thalamic nucleus: selective decrease of parvalbumin-immunoreactive thalamocortical projection neurons.

This study was designed to examine possible anatomical changes of thalamocortical circuits in schizophrenics. Previous immunocytochemical studies have shown that parvalbumin, a calcium-binding protein, occurs in thalamocortical projection neurons, but not in GABAergic interneurons in the anteroventral thalamic nucleus (AN). Using parvalbumin-immunocytochemistry we investigated the densities of thalamocortical projection neurons in the AN of schizophrenic cases (n = 12) and controls (n = 14). The densities of all neurons in the AN were estimated by Nissl-staining. The majority of thalamocortical projection neurons in AN were identified by parvalbumin-immunoreaction. Significantly reduced densities of thalamocortical projection neurons were estimated in the right (P = 0.003) and left AN (P = 0.018) in schizophrenic subjects. The densities of all neurons in right and left AN were also diminished in schizophrenics; however, these decreases did not reach statistical significance. The reductions of parvalbumin-positive thalamocortical projection neurons were not correlated with the length of disease, this finding supporting the neurodevelopmental etiology of structural abnormalities in schizophrenia.

Adult↗
PubMed1998

Nitric oxide synthase-containing neurons in the human hypothalamus: reduced number of immunoreactive cells in the paraventricular nucleus of depressive patients and schizophrenics.

The neuroanatomical distribution of nitric oxide synthase-immunoreactive neurons was investigated in post mortem hypothalami of 10 patients suffering from schizophrenia, eight patients with depression and 13 matched control cases. Neuronal nitric oxide synthase containing nerve cells were detected in several hypothalamic nuclei including the medial preoptic region, the ventromedial, infundibular and suprachiasmatic nuclei and the lateral hypothalamus. The vast majority of hypothalamic nitric oxide synthase-immunoreactive neurons was found to be located in the paraventricular nucleus. Both magno and parvocellular paraventricular neurons contained the enzyme. A small subset of immunoreactive parvocellular paraventricular neurons co-expresses corticotropin-releasing hormone. The supraoptic nucleus did not contain nitric oxide synthase-immunoreactive neurons. Cell counts of paraventricular nitric oxide synthase-positive neurons in controls, schizophrenics and depressed patients revealed a statistically significant reduction of cell density in the right paraventricular nucleus of depressed patients and schizophrenics as compared to controls. The total amount of nitric oxide synthase-immunoreactive paraventricular neurons was smaller in depressive and schizophrenic patients than in normal cases. The putative pathophysiologic significance of the reduced expression of paraventricular nitric oxide synthase in depressive patients might be related to the supposed regulatory function of nitric oxide in the release of corticotropin-releasing hormone and arginine-vasopressin and/or oxytocin, which have been reported to be over-expressed in the so-called endogenous psychoses, especially in depression.

Adult↗
PubMed1997

Changes in CSF spaces differ in endogenous and neurotic depression. A planimetric CT scan study.

Regional planimetric measurements of internal and external CSF spaces were performed in CT scans of 23 patients with endogenous depression (ICD 9, 296.1) and 28 patients with neurotic depression (ICD 9, 300.4) as compared to 56 control individuals without neuropsychiatric disorder. In female patients with endogenous depression, but not in men, the bilateral upper cortical sulci were widened, especially in the frontal regions, and the third ventricle was enlarged. In contrast, the female neurotic depressed group showed no enlargement of CSF spaces, but a narrowing of the Sylvian fissure and of the basal frontal lobe reaching level of significance in the right fronto-temporal region (P = 0.005). No narrowing of CSF spaces was observed in women with endogenous depression. A discriminant analysis of significantly changed CSF regions resulted in a correct classification in 82.4% of depressed women in either the endogenous or the neurotic group. Determination of divergent types of brain pathology might prove as a useful tool in validating the differential classification of these two main subtypes of affective disorders.

Adult↗
PubMed1992

[Histochemical light and electron microscopic investigations on an eosinophilic granuloma].

An eosinophilic granuloma has been investigated by means of histochemical proofs for enzymes and tissue elements and common staining methods. The best method was be found the proof for the enzyme phenol oxidase (EC 1.14.18.1). In this way it is possible to determine eosinophils rapidly and surely and to receive an overview on the frequency and distribution of these cells. The histiocytic-like cells was identified electron microscopical as Langerhans' cells. This cells are in narrow contact to many eosinophilic granulocytes. Their granula have manifold changes in their structure. The granula are possibly able to produce new structures of the cell. The eosinophilic granuloma correspond to a cell mediating immunological defence reaction approximate to the type of a delayed hypersensitivity.

Acid Phosphatase↗
PubMed1991

[An etiological study of eosinophilic granuloma].

By means of the proof for the enzyme phenol oxidase (PO; EC 1.14.18.1) was investigated, whether the eosinophilic granuloma correspond to a cell mediated immunological defence reaction. The method allowed to determine the eosinophils rapidly and surely and give an overview on the frequency and distribution of these cells. By electron microscopy was Langerhans-cells identified in close contact to many eosinophils. Their granula shows manifold changes in their structure. The eosinophilic granuloma is a cell mediated defence reaction approximate to the type of a delayed hypersensitivity.

Animals↗
PubMed1991

[Electroneurographic findings in workers exposed to mercury].

25 mercury-exposed workers as well as 27 age-matched controls were investigated in an electroneurographic study. The population of mercury-exposed workers was found to have --an increased latency of distal motor action potential at both median and peroneal nerves --an increased latency of distal sensory action potential at median nerve --a decrease of amplitudes of evoked muscle potentials at both median and peroneal nerves --a reduced motor nerve conduction velocity at both examined nerves --a reduced antidromic sensory nerve conduction velocity at median nerve. To detect early changes in nerval function we recommend regularly electroneurographic examinations of mercury-exposed people.

Adolescent↗
PubMed1990

[The pathogenesis of nasal mucosa polyps, studied with histochemical detection of phenol oxidase (E. C. 1.14.18.1)].

There were investigated polyps of the nasal mucous membrane with the histological diagnosis: allergic-hyperergic, lympho-plasma cellular, and angioma-like. Using the phenol oxidase reaction, it was possible to integrate the allergic-hyperergic and the lympho-plasma cellular polyps into the pathologic course of cell mediated immunological defence reactions in which the eosinophilic granulocytes have an essential role. The eosinophils are typical for the immunological character of the defense reaction.

Female↗
PubMed1987

In vitro caries-like lesion production by Streptococcus mutans and Actinomyces viscosus using sucrose and starch.

We investigated the formation of caries-like lesions on root and enamel sections by S. mutans and A. viscosus when grown in four different carbohydrate substrates. The substrates were: sucrose, starch + alpha-amylase, and a combination of starch and sucrose with and without alpha-amylase. Twenty-four sections with exposed windows on both the root and enamel surfaces were exposed to the individual bacterial species in each of the four substrates for three weeks. At three weeks, the sections were removed and lesion depths measured. When grown in sucrose alone, S. mutans produced significantly deeper lesions in both root and enamel surfaces when compared with A. viscosus. However, S. mutans failed to produce lesions when grown in "limited" sucrose with starch added, whereas A. viscosus in this same substrate produced lesions in the enamel and root surfaces. A viscosus also produced either similar or significantly deeper lesions in both root and enamel surfaces, when compared with S. mutans grown in the two substrates with amylase. Thus, under these in vitro conditions, it was demonstrated that A. viscosus could utilize starch, whereas utilization of starch by S. mutans was alpha-amylase-dependent.

Actinomyces↗
PubMed1986

Acute alcohol ingestion reduces heart rate variability.

Blood pressure, heart rate and heart rate variability (HRV) prior and during acute ethanol intoxication (0.7 g/kg) were studied in 8 healthy volunteers. Blood pressure and heart rate remained unaltered during intoxication. While HRV was significantly reduced immediately after ingestion (2P = 0.01). It is speculated that the reduction of HRV after heavy ethanol consumption contributes to the genesis of cardiac arrhythmias in chronic alcoholics with or without clinical evidence of heart disease.

Adult↗
PubMed1986

Heart rate variability in chronic alcoholics: a follow-up study.

Heart rate variability (HRV) was studied in 11 chronic alcoholic subjects, 1-30 days after the beginning of abstinence and again 5, 12 and 24 weeks later. Two patients could be re-examined after 19 and 22 months, respectively. In the follow-up study, the total patient group showed a statistically significant increase in HRV with prolonged abstinence of at least 6 months. No recovery of efferent vagal function was found in 4 patients. It is suggested that the vagal neuropathy may improve in chronic alcoholics, but perhaps only in patients with a short to moderately long duration of drinking history or a functional rather than an organic vagal damage.

Adult↗
PubMed1985

[Course of heart beat variability following acute alcohol intake].

Blood pressure, heart rate and mean momentary arrhythmia were measured in 16 healthy test persons before and after acute alcohol ingestion. While the blood pressure remained unchanged, heart rate and mean momentary arrhythmia showed significant differences in comparison to the initial value, in which case the clearer change of the mean momentary arrhythmia in relation to the heart rate emphasizes the sensitivity of the parameter. The results are discussed as a sequel of the increase of sympathetic activity of alcohol/acetaldehyde.

Adult↗
PubMed1985

[Autonomic alcoholic polyneuropathy].

Measurement of heart rate variability was performed in a group of 106 healthy volunteers and 31 alcoholics. The mean momentary arrhythmia of normal individuals shows an exponential decrease with growing age. In 5 of 31 alcoholics a cardiac autonomic neuropathy was found with this parameter. The withdrawing alcoholics had a significant increase of heart rate and decrease of heart rate variability compared to later measurements, what is in agreement with the concept of hyperexcitability in early withdrawal.

Adolescent↗
PubMed1985

Heart rate variability of chronic alcoholics in withdrawal and abstinence.

Measurement of heart rate variability was performed in 106 healthy volunteers and 31 alcoholics. The mean momentary arrhythmia (MMA) of normal individuals showed an exponential decrease with increasing age. Cardiac autonomic neuropathy was found in 5 of 31 alcoholics. In agreement with the concept of hyperexcitability the withdrawing alcoholics had a significant increase in heart rate and decrease in MMA compared to later measurements. The result suggests that the diagnosis of autonomic alcoholic neuropathy may be reliable only after at least a one week period of abstinence from alcohol.

Adolescent↗