Increased limbic blood flow and total sleep deprivation in major depression with melancholia

Single photon emission computed tomography (SPECT) with technetium-99m-d,l-hexamethyl-propylene amine oxime (99Tcm-HMPAO) was carried out in 20 melancholic patients before and after total sleep deprivation. Findings in 11 responders to total sleep deprivation (defined by > or = 40% improvement on the Hamilton Rating Scale for Depression) were compared with findings in nine nonresponders. On the basis of a semiquantitative evaluation of SPECT findings, responders showed relative hyperperfusion before sleep deprivation in the right anterior cingulate cortex and in the right and left fronto-orbital cortex and basal cingulate gyrus. Responders who showed > or = 50% improvement also showed hippocampal overactivation before sleep deprivation. It is possible that limbic overactivation may characterize depressed responders to total sleep deprivation as a distinct subtype. Another possibility is that the pattern of limbic hyperactivation reflects the increased number of bipolar patients in the responder group, with response to total sleep deprivation being only a covariate of this bipolar-unipolar distinction.

Single photon emission computerized tomography assessment of cerebral dopamine D2 receptor blockade in depression before and after sleep deprivation--preliminary results

The antidepressant properties of total sleep deprivation (TSD) have been well established. There is some evidence that TSD may improve depression by altering central dopamine (DA) function. We therefore studied five depressed TSD responders and five TSD nonresponders after sleep and after TSD and five controls after sleep with IBZM single photon emission computerized tomography (SPECT). Responders showed a significant decrease (Wilcoxon--test p < 0.05) of relative basal ganglia D2 receptor occupancy after TSD compared to nonresponders (change score responders versus nonresponders p < 0.05, U-test). The data are interpreted as a sign of an enhanced DA release in responders. The results confirm previous hypotheses of dopaminergic involvement in the therapeutic action of TSD and indirectly support a dopamine hypotheses of depression.

Cortisol and beta-endorphin responses to sleep deprivation in major depression--the hyperarousal theories of sleep deprivation

To test theories that response to sleep deprivation in depression is the result of either stress reactions or down-regulation of hyperarousal, the early morning cortisol and beta-endorphin levels of depressed sleep deprivation responders and nonresponders before and after sleep deprivation were compared (areas under the curve of 8 blood samples between 7:30 and 10 a.m.). The beta-endorphin response was significantly different in responders and nonresponders, whereas all other comparisons remained nonsignificant. The results do not support theories that sleep deprivation acts as a stressor, but are not contradictory to the hyperarousal hypothesis of sleep deprivation.

[Benzodiazepine monotherapy in acute schizophrenia]

Two patients with acute schizophrenic or schizo-affective psychosis were treated with benzodiazepine-monotherapy. In the first patient with paranoid-hallucinatory psychosis, catatonic symptoms disappeared completely after application of Lorazepam. Side effects of neuroleptic medication (neuroleptic turbulences) were the reason for benzodiazepine treatment in the second patient. In neither patients were psychotic symptoms observed during several weeks on benzodiazepine medication. Subsequently, no further neuroleptic treatment was necessary in one patient. Benzodiazepine effects on schizophrenia are probably caused by an activation of inhibitory GABA-ergic neurons. Besides stupor and catatonia, severe side effects of neuroleptic treatment or even contra-indications of neuroleptic medication may be an indication for benzodiazepine treatment in acute schizophrenia.

Regulation and properties of extracellular signal-regulated protein kinases 1, 2, and 3

The extracellular signal-regulated kinases ERK1 and ERK2 are 43- and 41-kd enzymes activated by many extracellular cues. They lie within a protein kinase cascade that is used to achieve many cellular responses. In addition to the wide variety of regulatory contexts in which they are activated, they phosphorylate important regulatory proteins, including receptors, transcription factors, cytoskeletal proteins, and other protein kinases. Thus, the stimulation of this kinase cascade is thought to have a pleiotropic action. ERK1 and ERK2 are controlled by phosphorylation on threonine and tyrosine. To understand the regulatory mechanisms, wild-type and mutant ERKs were expressed in bacteria and phosphorylated with MEK, the enzyme that is upstream of ERKs. Wild-type proteins could be activated 500- to 1,000-fold in vitro by MEK. ERK3, an enzyme of 62 kd and only 50% identical to ERK1 and ERK2 in the catalytic core, was also phosphorylated by MEK in vitro. This suggests that all three of these enzymes are targets of common signaling pathways.

Regulation and properties of extracellular signal-regulated protein kinases 1 and 2 in vitro

Extracellular signal-regulated protein kinases (ERK) 1 and 2 and mutants of each were expressed in bacteria with a hexahistidine tag and purified using nickel-chelate chromatography. Basal activity of wild type ERK2 was approximately 2 nmol/min/mg. Self-catalyzed phosphorylation occurred in vitro on the major physiological site of tyrosine phosphorylation in an intramolecular reaction. Rabbit muscle ERK activator activated ERK2 500-1000-fold up to a specific activity (approximately 2 mumol/min/mg) approximating that of ERK1 purified from stimulated cells (Boulton, T.G., Gregory, J.S., and Cobb, M.H. (1991) Biochemistry 30, 278-286). ERK1 could also be activated by the ERK activator to the same extent. Mutants lacking the major site of tyrosine phosphorylation were autophosphorylated at a greatly reduced rate and were no longer highly activated by the ERK kinase. Mutants lacking the major site of threonine phosphorylation were autophosphorylated at the same or an enhanced rate, but the kinase activity of these mutants depended on the residue used to replace the threonine. Replacement by glutamate rendered the kinase capable of being activated by ERK activator, while replacement by alanine did not. Thus, the carboxyl group of glutamate can provide at least some of the features introduced by phosphothreonine in activated ERKs.

A test-retest study of cerebral blood flow during somatosensory stimulation in depressed patients with schizophrenia and major depression

Six depressed patients with schizophrenia and 6 depressed patients with major depression were investigated before and during somatosensory stimulation (SS) with Tc-99m HMPAO SPECT. 8 controls were investigated only under resting conditions. The results can be summarized as follows: 1. Both psychiatric patient groups were hypofrontal (dorsolateral prefrontal cortex) compared to controls. 2. Hypofrontality was further enhanced by SS, significantly only in affective psychoses in the right inferior frontal lobe and in the right frontal hemisphere in total, in schizophrenia in the left dorsolateral prefrontal cortex. 3. Within the frontal lobes different regions were affected by SS in the two diagnostic groups. 4. In the right inferior parietal lobe SS response was significantly different in the two illnesses with schizophrenia showing a relative decrease, affective psychoses showing a relative increase of activity. 5. SS produced an increase of cerebral blood flow in subcortical regions (statistically significant contralateral to SS in thalamus and basal ganglia, ipsilateral to SS in cerebellum), a pattern which was common to all psychiatric patients. 6. Somatosensory cortex flow was not changed by SS. In conclusion, we could not fully confirm our hypotheses that similar blood flow abnormalities in different illnesses during SS are only caused by similarities in depressive psychopathology. Instead, depressed patients with schizophrenia were different from depressed patients with major depression in showing decreased activity in interrelating brain regions participating in an attentional network.

Alterations of drive in differential diagnosis of mild depressive disorders--evidence for the spectrum concept of endogenomorphic affective psychosis

Specific alterations of drive have been cited in the literature to separate mild depressive disorders belonging to the bipolar or endogenomorphic spectrum from depressive disorders of other origin. To test this hypothesis 44 patients with mild depressive disorder were studied longitudinally. Presence of inhibition of drive or thought predicted outcome in mania or melancholia. The data are interpreted as evidence for the spectrum concept of affective psychosis.

Effects of sleep deprivation on the limbic system and the frontal lobes in affective disorders: a study with Tc-99m-HMPAO SPECT

We studied 10 patients with melancholia before and after sleep deprivation and 8 controls with Tc-99m-hexamethylpropylenamineoxime (HMPAO) single photon emission computed tomography (SPECT). All depressed subjects showed relative hypoperfusion in the left anterolateral prefrontal cortex under both conditions. Only responders showed relative hyperperfusion in parts of the limbic system and a reduction of blood flow in these regions after sleep deprivation.

Successful treatment of tardive akathisia with moclobemide, a reversible and selective monoamine-oxidase-A inhibitor. A case study

Tardive akathisia (TA) is a well-documented side-effect of neuroleptic treatment. The underlying mechanism is poorly understood, and treatment is unsatisfactory. In this case report, TA that occurred in the course of a tardive dyskinesia (TD) was successfully treated with the monoamine-oxidase-A inhibitor moclobemide. With respect to the mechanism of action, it may be hypothesized that dopaminergic supersensitivity in the mesocortical region is counteracted by enhanced inhibition of primarily noradrenergic neurotransmission.

[Formal thought disorders and speech disorders in schizophrenia--new findings from empirical studies?]

The investigation of formal thought and speech disorders in schizophrenia is hampered by the missing differentiation of speech and thought. Empirical investigations paying attention to this differentiation do not argue for specific schizophrenic speech or thought disorders but for a clinically relevant continuum of these disorders within the group of endogenous psychoses.

The early course of atypical depression

The early course was studied of 29 atypical depressives with first onset of affective disorder not otherwise specified in DSM-III-R. Psychopathology was not stable over time in all patients, with some showing bipolar disorder or melancholia.

Sulfated N-linked oligosaccharides affect secretion but are not essential for the transport, proteolytic processing, and sorting of lysosomal enzymes in Dictyostelium discoideum

Although previous studies have indicated that N-linked oligosaccharides on lysosomal enzymes in Dictyostelium discoideum are extensively phosphorylated and sulfated, the role of these modifications in the sorting and function of these enzymes remains to be determined. We have used radiolabel pulse-chase, subcellular fractionation, and immunofluorescence microscopy to analyze the transport, processing, secretion, and sorting of two lysosomal enzymes in a mutant, HL244, which is almost completely defective in sulfation. [3H]Mannose-labeled N-linked oligosaccharides were released from immunoprecipitated alpha-mannosidase and beta-glucosidase of HL244 by digestion with peptide: N-glycosidase. The size, Man9-10GlcNAc2, and processing of the neutral species were similar to that found in the wild type, but the anionic oligosaccharides were less charged than those from the wild-type enzymes. All of the negative charges on the oligosaccharides for HL244 were due to the presence of 1, 2, or 3 phosphodiesters and not to sulfate esters. The rate of proteolytic processing of precursor forms of alpha-mannosidase and beta-glucosidase to mature forms in HL244 was identical to wild type. The precursor polypeptides in the mutant and the wild type were membrane associated until being processed to mature forms; therefore, sulfated sugars are not essential for this association. Furthermore, the rate of transport of alpha-mannosidase and beta-glucosidase from the endoplasmic reticulum to the Golgi complex was normal in the mutant as determined by the rate at which the newly synthesized proteins became resistant to the enzyme, endo-beta-N-acetylglucosaminidase H. There was no increase in the percentage of newly synthesized mutant precursors which escaped sorting and were secreted, and the intracellularly retained lysosomal enzymes were properly localized to lysosomes as determined by fractionation of cell organelles on Percoll gradients and immunofluorescence microscopy. However, the mutant secreted lysosomally localized mature forms of the enzymes at 2-fold lower rates than wild-type cells during both growth and during starvation conditions that stimulate secretion. Furthermore, the mutant was more resistant to the effects of chloroquine treatment which results in the missorting and oversecretion of lysosomal enzymes. Together, these results suggest that sulfation of N-linked oligosaccharides is not essential for the transport, processing, or sorting of lysosomal enzymes in D. discoideum, but these modified oligosaccharides may function in the secretion of mature forms of the enzymes from lysosomes.

Biochemical and genetic analysis of the biosynthesis, sorting, and secretion of Dictyostelium lysosomal enzymes

Dictyostelium discoideum is a useful system to study the biosynthesis of lysosomal enzymes because of the relative ease with which it can be manipulated genetically and biochemically. Previous studies have revealed that lysosomal enzymes are synthesized in vegetatively growing amoebae as glycosylated precursor polypeptides that are phosphorylated and sulfated on their N-linked oligosaccharide side-chains upon arrival in the Golgi complex. The precursor polypeptides are membrane associated until they are proteolytically processed and deposited as soluble mature enzymes in lysosomes. In this paper we review biochemical experiments designed to determine the roles of post-translational modification, acidic pH compartments, and proteolytic processing in the transport and sorting of lysosomal enzymes. We also describe molecular genetic approaches that are being employed to study the biosynthesis of these enzymes. Mutants altered in the sorting and secretion of lysosomal enzymes are being analyzed biochemically, and we describe recent efforts to clone the genes coding for three lysosomal enzymes in order to better understand the molecular mechanisms involved in the targeting of these enzymes.

[The prognosis of carcinoid tumors of the stomach]

Follow-up examinations were carried out in 55 patients with small carcinoid tumours in the stomach (diameter 0.5-1.7 cm). For the most part, the tumours were located within the body and fundus of the stomach, with only 3 being found in the antrum. Thirty-five of the 55 patients (63.6%) had multiple gastric carcinoids, while in 46 patients (83.6%) concomitant chronic atrophic gastritis was also present. Eight patients were treated surgically, while 47 patients were merely kept under endoscopic/bioptic surveillance. In 34 out of 40 patients in whom the diagnosis had been established more than 6 months previously (longest observation period 13 years), follow-up findings were available (7 surgical patients, 27 non-operated patients). The patients submitted to surgery (average follow-up period 3.5 years) are alive and free of complaints between 1 and 9 years post-op; no metastases have occurred, but a recurrent tumour has developed in a single patient. Among the 27 non-operated patients (average follow-up period 3.6 years), 3 have died of diseases unrelated to the carcinoid tumours, in none of the other patients has there been any change in the findings. On the basis of these results it is concluded that, in carcinoid tumours of the stomach with a diameter of less than 1.0 cm, surgical treatment is not absolutely necessary, and that, in comparison with the risks represented by surgical mortality and post operative morbidity, regular endoscopic/bioptic follow-up can be considered to be adequate.