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Biomedical subjects

F Lotstra

Publications and source records attributed to F Lotstra.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Cerebral glucose metabolism in schizophrenia. Studies using positron-emission tomography].

Several studies using positron emission tomography with 18F-fluorodeoxyglucose (18F-FDG) have revealed functional hypofrontality in schizophrenia. However, frontal hypometabolism is not consistently found and is not specific to schizophrenia. Basal ganglia glucose hypermetabolism related to neuroleptic treatment has been demonstrated. Methodological and clinical differences between studies are discussed in this paper.

Adult↗
PubMed1990

A double-blind comparative study of remoxipride and haloperidol in schizophrenic and schizophreniform disorders.

The antipsychotic effect of remoxipride was compared to that of haloperidol in a randomized double-blind study with parallel group design comprising 98 patients with schizophrenia or schizophreniform disorder according to DSM-III. After a 3-7 day placebo washout period, patients received either 150-600 mg of remoxipride or 5-20 mg of haloperidol daily for 6 weeks. No significant differences in efficacy were found between the two treatments. Treatment-emergent checklist symptoms such as hypokinesia, rigidity, and tremor occurred more frequently and were more severe during haloperidol than during remoxipride treatment despite a significantly higher concurrent use of anticholinergic drugs in the haloperidol group. Haloperidol-treated patients reported greater increases in sleep and salivation than remoxipride-treated patients. Shoulder shaking and tremor were reported as occurring more frequently in the haloperidol group according to the Simpson and Angus rating scale for extrapyramidal symptoms. In summary, the two drugs seemed to be equally efficacious, though the tolerability profile favoured remoxipride.

Adult↗
PubMed1989

Neuropeptide Y-containing neurons in the human infant hippocampus.

Using immunohistochemistry, high concentrations and widespread distribution of neuropeptide Y-immunoreactive (NPY-IR) neurons were found and examined in each region of the hippocampal formation from birth to 42 years. NPY interneurons are particularly numerous in the stratum oriens of the CA1 subfield, in the deep layers of the subicular complex and entorhinal cortex. They are multipolar round, ovoid or triangular or bipolar and fusiform. There is a dense network of NPY-IR nerve fibers in the subicular complex and the entorhinal cortex. In addition, numerous NPY-IR nerve cell bodies and fibers are observed in the angular bundle and the adjacent white matter and this contrasts with the absence of NPY immunoreactivity in the fiber tracts of the alveus. These NPY-IR neurons which correspond to the interstitial neurons of the white matter, have the morphology and the size of the interneurons detected in the cortex. During the postnatal brain growth spurt which corresponds to the phase of rapid myelination, there is no decline in total number of NPY-IR neurons but there is a decrease in density. They have been spread apart by the growth of the rest of the tissue. So in humans, the total number of NPY nerve cell bodies in the hippocampal system, firmly established at birth, is not modified during consequent brain growth which continues until ages 3-4 years and stays stable at least until age 42 years.

Adult↗
PubMed1987

High concentration of cholecystokinin neurons in the newborn human entorhinal cortex.

Numerous cholecystokinin (CCK)-immunoreactive cells are detected in the newborn human entorhinal cortex. They are located essentially in layer II and in the superficial part of layer III. Their shape and size indicate that they are interneurons. Most of them are vertically oriented and have beaded processes reaching layer I and the deep part of layer III. The cell type most frequently observed are bipolar cells with an ovoid cell body measuring 8-10 microns across and 15 microns in length. No CCK immunoreactivity is seen in the large stellate and pyramidal cells.

Age Factors↗
PubMed1986

Synenkephalin in bovine and human spinal cord.

Synenkephalin, which comprises 70 residues at the aminoterminal of proenkephalin, was studied with immunocytochemical methods in the human and bovine spinal cord. Immunoreactive fibers had the same general distribution as methionine-enkephalin, but not as leucine-enkephalin fibers. They were found in all spinal layers and were most numerous in lamina II (outer zone) and V-VI (lateral portion). Synenkephalin immunoreactivity was overall less dense than that of the enkephalins. These results suggest that proenkephalin is the precursor protein also in enkephalinergic neurons of the human spinal cord.

Animals↗
PubMed1985

Co-existence of cholecystokinin- or gastrin-like peptides with other peptides in the hypophysis and the hypothalamus.

The presence of cholecystokinin and gastrin has been reported in the hypothalamohypophyseal system. These peptides present a peculiar distribution in the hypothalamic nuclei, the median eminence, and the neurohypophysis. CCK and gastrin have close relationships with other peptides like oxytocin, CRF, vasopressin, and the enkephalins; these relationships vary in different projecting areas and in different types of hypothalamic neurons. The functional role of G-CCK in neurosecretion seems to be linked to the role of these closely associated peptides and certainly deserves further investigation.

Animals↗
PubMed1985

Substance P, enkephalins, somatostatin, cholecystokinin, oxytocin, and vasopressin in human spinal cord.

Several neuropeptides were immunohistologically studied in normal human spinal cords. Substance P, methionine-enkephalin, leucine-enkephalin, and cholecystokinin positive fibers were found in all cytoarchitectonic layers, with a specific distribution pattern for each peptide. Somatostatin, oxytocin, and vasopressin immunoreactivities were restricted to particular spinal layers. Perikarya and proximal dendrites were visualized and classified by comparison with previous Golgi analyses. Substance P was contained in "radiate cells" of layer III, methionine-enkephalin in marginal neurons as well as in layer II "stellate cells," and somatostatin in layer II "islet cells." Several results differed from those reported in other species. Chemical neuroanatomy may provide new insights into the neuronal organization of the human spinal cord.

Adult↗
PubMed1984

Reduced cholecystokinin immunoreactivity in the cerebrospinal fluid of patients with psychiatric disorders.

The close relationship of cholecystokinin peptides with some of the dopamine pathways and the limbic system suggests a putative role for these peptides in the pathophysiology of neuropsychiatric disorders such as Parkinson's disease, manic-depression and schizophrenia. By use of radioimmunoassay, we report a significant decrease in cholecystokinin-immunoreactivity in the cerebrospinal fluid of patients with bipolar manic-depression and untreated schizophrenia in comparison to control subjects.

Adult↗
PubMed1984

Possible misinterpretations of radioimmunoassay results of endocrine tissues containing peptides in the micromolar range.

This paper describes the possible inhibition of labelled peptidic antigen antibody bindings of high affinity (affinity constant above 10(11) l/mol) by structurally non-related synthetic peptides according to their primary aminoacid sequence at concentrations of only 10(-6) mol/l i.e. approximatively 10(-3) g/l, in two radioimmunoassays. Such concentrations of peptides are present in 10% weight/volume suspension of various neuroendocrine and endocrine fresh tissues and may therefore be responsible for false positive results.

Animals↗
PubMed1983

Cholecystokinin varies in the posterior pituitary and external median eminence of the rat according to factors affecting vasopressin and oxytocin.

Using radioimmunoassay (RIA), the content of gastrin-cholecystokinin family peptide immunoreactivity (G-CCK-IR), in the posterointermediate lobe (PIL) of the rat pituitary, has been determined in several experimental conditions. G-CCK-IR levels are significantly higher in males than in females. Salt loading induces a significant decrease of G-CCK-IR in animals of either sex. In males, G-CCK-IR levels are lower than controls 21 days after either castration or daily subcutaneous oestradiol injections. Using immunocytochemistry, G-CCK-IR disappears from the external median eminence 21 days after adrenalectomy. Our results show that, in addition to sex difference, factors affecting the vasopressin and/or oxytocin levels in the posterior pituitary and external median eminence also affect G-CCK-IR in the same regions. Cholecystokinin may therefore be of importance in functions related to these hormones.

Adrenalectomy↗
PubMed1983

CCK nerve terminals in the rat striatal and limbic areas originate partly in the brain stem and partly in telencephalic structures.

After direct injection of colchicine into the rat rostral caudateputamen, levels of cholecystokinin-like immunoreactive (CCK-IR) material in this part of the nucleus are significantly lowered, and CCK-IR neuronal cell bodies are not demonstrable in the caudateputamen, although numerous ones are revealed in some adjacent telencephalic regions. Direct injection of kainic acid into the rostral caudate-putamen is not followed by a decrease of CCK-IR material in the lesioned region. Twenty one days after injection of 6-hydroxydopamine into the rat ventral mesencephalon, a significant decrease of CCK-IR material is observed in the frontal pole, the pyriform cortex, the nucleus accumbens and the ventral mesencephalon itself, but not in the caudate-putamen. After brain stem hemitransection, no decrease in CCK-IR material is observed in the rostral caudate-putamen.

Animals↗
PubMed1983

Proenkephalin, [Met]enkephalin, and oxytocin immunoreactivities are colocalized in bovine hypothalamic magnocellular neurons.

The distribution of proenkephalin and [Met]enkephalin immunoreactivities in the bovine hypothalamo-neurohypophyseal system was studied by use of specific antisera. Proenkephalin and [Met]enkephalin immunoreactivities were found in magnocellular neuronal cell bodies in the dorsal part of the supraoptic nuclei and in the peripheral part of the paraventricular nuclei. A densely staining network of nerve terminals was found in the external part of the median eminence and in the posterior hypophysis. This general distribution is identical to that of the neurohypophyseal hormone oxytocin. The precise localization of proenkephalin and [Met]enkephalin immunoreactivities was compared to the distribution of oxytocin and vasopressin in serial 5-micron sections through the magnocellular nuclei. Oxytocin immunoreactivity was nearly always present in cells that were stained with proenkephalin and [Met]enkephalin antisera. The vasopressin-immunoreactive cells were never stained with either the proenkephalin or the [Met]enkephalin antisera.

Animals↗
PubMed1983

General anesthesia after neuroleptic malignant syndrome.

The neuroleptic malignant syndrome (NMS) is an uncommon and potentially lethal complication of therapy with neuroleptics characterized by pallor, hyperthermia, and extrapyramidal signs (Delay and Deniker, 1968). Malignant hyperthermia (MH) is a rare but often fatal complication of general anesthesia characterized by hyperpyrexia and muscle rigidity, but not related to neuroleptic therapy. For both syndromes, NMS and MH, a common pathophysiology has been considered (Meltzer, 1973; Itoh, 1977; Caroff, 1980). These two syndromes may also be clinically indistinguishable from "acute lethal catatonia" characterized by fever, muscular hypertonicity, and stupor, first described by Stauder in 1934. We now report a case in whom NMS appeared following neuroleptic treatment for a psychotic depressive syndrome. After remission from the NMS, the patient underwent general anesthesia nine times for electroconvulsive therapy (ECT) without ill effect. This case supports the theory of distinct pathogenic mechanisms for both NMS and MH.

Anesthesia, General↗
PubMed1982

Immunohistochemical evidence for cholecystokinin-like peptides in neuronal cell bodies of the rat spinal cord.

Cholecystokinin-like immunoreactivity has been demonstrated by radioimmunoassay and immunocytochemistry in the spinal cord of various mammals, in particular in nerve fibers of the superficial layers of the posterior column, but had not been detected in neuronal cell bodies. We report immunohistochemical evidence for the presence of a group of cholecystokinin-containing neuronal cell bodies in the lumbar spinal cord of the rat. This group of cells is only visualized after direct injection of colchicine into the spinal cord and is located near the central canal in the intermedio-medial nucleus of area X of Rexed.

Animals↗