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Biomedical subjects

P Blockx

Publications and source records attributed to P Blockx.

At least 19 recordsLinked to original sources
PubMed2002

Pseudodystrophy. A conversion disorder mimicking reflex sympathetic dystrophy.

The authors suggest some criteria by which pseudodystrophy and reflex sympathetic dystrophy, although sharing some similar clinical features, can be distinguished as two different conditions, each requiring its own approach and management. The most important distinction is found on bone scintigraphy. In reflex sympathetic dystrophy the bone scan shows a typical increased tracer uptake (at least during stages I and II); in pseudodystrophy there is a normal or decreased tracer uptake in the affected region. Moreover the vascularization is increased in reflex sympathetic dystrophy stage I, whereas in pseudodystrophy hypovascularization is found from the beginning. The clinical features, as well as the results of technical investigations, psychological evaluation and treatment of 4 patients with pseudodystrophy are presented. The importance of distinguishing this condition from reflex sympathetic dystrophy is stressed.

Adolescent↗
PubMed2000

Gastric emptying rate measurement after vertical banded gastroplasty.

BACKGROUND: In vertical banded gastroplasty (VBG), a small proximal gastric pouch is created, which is believed to fill rapidly and to empty slowly. METHODS: In 13 patients who underwent VBG, gastric emptying rate was measured. A radiolabelled solid test meal was used before and 2 weeks after operation. From a region of interest above the whole stomach, the proximal pouch and the distal stomach, half emptying time as well as retention percentage were derived. RESULTS: All patients experienced early satiety and gastric fullness after ingestion of a small test meal. The proximal pouch emptied rapidly. The evacuation of the test meal from the whole gastric region as well as the distal stomach were not altered significantly by the operation. CONCLUSION: VBG is a safe operation which reduced weight significantly. Early satiety, however, induced by this technique, cannot be explained alone by slow emptying of the proximal pouch. The nature of the outlet of the pouch as well as the behavior of its wall must be considered.

Adult↗
PubMed2000

Comparison of anterior and geometric mean liquid and solid gastric emptying rates in dogs and in patients after partial gastrectomy.

OBJECTIVE: The purpose of this study was to determine if geometrical correction is necessary in the study of gastric emptying rate (GER) for liquids, using a low-energy radionuclide, such as 99mTc. Solid test meals were considered the reference. METHODS: Both solid and liquid GERs were investigated using regional analysis. Anterior data were compared with geometrically corrected values in 15 dogs and 9 partial gastrectomy patients. RESULTS: Anterior and geometrically corrected measurements differed significantly for solid food in the whole gastric region and in the antrum. Geometrically corrected values differed slightly from anterior data after partial gastrectomy. No difference was found for liquid food. Liquids redistributed much faster than solids within the stomach. CONCLUSION: Measurement of GER using a single-phase liquid meal does not require geometrical correction. This is due to the rapid intragastric redistribution of the liquid. Geometrical correction for solid food can be omitted only after partial gastrectomy.

Adult↗
PubMed1999

What is reflex sympathetic dystrophy?

In the literature there is no unanimity with respect to the diagnosis of reflex sympathetic dystrophy (RSD). Frequently, the diagnosis is established on mere clinical grounds. In our opinion, however, bone scintigraphy is of major importance for the diagnosis. Using this examination, true RSD can be clearly differentiated from other conditions which are incorrectly diagnosed and treated as RSD. If the bone scan is not suggestive of RSD, the clinical picture, radiological examination and vascular scan may lead to the correct diagnosis. This may be a pseudodystrophy, in which a hypovascularization is found right from the start, while in true RSD there is initially a hypervascularization. Other conditions which may be confused with RSD are causalgia, neurotic compulsive postures, hysterical conversion, malingering and even self-mutilation. In the spontaneous course of RSD three phases can be distinguished. Stage I is the warm or hypertrophic phase, stage II the cold or atrophic phase. Per definition the third phase corresponds to stabilization or, in rare instances, to healing. By means of the vascular scan the correct stage can be determined, and the results of treatment evaluated. Finally it should be noted that in children the condition is completely different from true RSD, as it concerns a pseudodystrophy or disuse-related dystrophy. This condition may also be seen in adults and adolescents, usually females. The bone scan is always negative. In this way bone scintigraphy constitutes the means to answer the question as to what RSD is and what it is not. An algorithm for the differential diagnosis is presented.

Adolescent↗
PubMed1997

Comparison of radionuclide labelled test meals versus endoscopy in the preoperative assessment of the gastric outlet patency.

A series of 39 patients with peptic ulcer disease is investigated with respect to gastric outlet obstruction. Two diagnostic tools are compared, namely endoscopy and evaluation of radionuclide meal emptying. Endoscopic obstruction was qualified as non passage of a 14 mm gastroscope. Gastric emptying reduction was considered clinically relevant when half emptying times exceeded 60 minutes for solids and 12 minutes for liquids. Comparison of both techniques of radionuclide meal emptying with endoscopy showed a poor correlation (accuracy 15/28), especially when liquid gastric emptying versus endoscopy was concerned.

Adolescent↗
PubMed1996

Lower serum transcortin (CBG) in major depressed females: relationships with baseline and postdexamethasone cortisol values.

This study has been carried out to examine (i) transcortin or corticosteroid binding globulin (CBG), the major glucocorticoid transport protein, in major depressed versus minor depressed and normal subjects; and (ii) the relationships between CBG and basal and postdexamethasone cortisol or adrenocorticotropic hormone (ACTH) values. Serum CBG was significantly lower in major depressed than in minor depressed subjects and normal controls. The significant decrease in serum CBG was observed in major depressed women but not in major depressed men. In depressed subjects, there was a significant and negative relationship between serum CBG and severity of illness. There were significant positive relationships between serum CBG and basal 8:00 a.m. plasma cortisol in normal volunteers (r = 0.87, P < 10(-4)) and depressed subjects (r = 0.40, P = 0.0002). There was no significant relationship between serum CBG and 24-h urinary cortisol. In depressed patients, there was a positive relationship between serum CBG and postdexamethasone cortisol (r = 0.31, P = 0.003). It is concluded that, in depression, serum CBG levels should be taken into consideration for the interpretation of baseline and postdexamethasone plasma total cortisol levels.

Adjustment Disorders↗
PubMed1996

Acute administration of buspirone increases the escape of hypothalamic-pituitary-adrenal-axis hormones from suppression by dexamethasone in depression.

Recently, our laboratory found a significant enhancing effect of L-5-hydroxy-tryptophan (L-5-HTP) on post-dexamethasone (DST) plasma adrenocorticotropic hormone (ACTH) and cortisol levels in major-but not in minor-depression. To further elucidate the effects of central serotonin (5-HT) activity on the negative feedback of glucocorticoids on hypothalamic-pituitary-adrenal (HPA)-axis function in depression, this study investigates the effects of buspirone, a 5-HT1A receptor agonist, on post-DST ACTH and cortisol levels in 75 depressed subjects. Plasma post-DST ACTH and cortisol concentrations were significantly increased by the acute administration of buspirone (30 mg PO) compared to placebo. There were no differences in buspirone-induced post-DST ACTH or cortisol responses between minor and major depression. There were significant correlations between post-DST ACTH and cortisol, and between post-DST-buspirone ACTH and cortisol. The buspirone-induced post-DST cortisol responses were significantly higher in depressed women than men. It is concluded that buspirone may augment ACTH and, consequently, cortisol escape from suppression by dexamethasone in major as well as in minor depression.

Adrenocorticotropic Hormone↗
PubMed1996

Stimulatory effects of L-5-hydroxytryptophan on postdexamethasone beta-endorphin levels in major depression.

Recently it has been shown that acute administration of 200 mg L-5-hydroxytryptophan (L-5-HTP) PO may increase post-dexamethasone (DST) adrenocorticotropic hormone (ACTH) and cortisol levels in major, but not minor, depressed subjects. This study aimed to examine the effects of 200 mg L-5-HTP PO on post-DST beta-endorphin levels in the same depressed subjects. It was found that in major, but not minor, depressed subjects, L-5-HTP significantly increased post-DST beta-endorphin concentrations as compared to placebo. The L-5-HTP-induced post-DST beta-endorphin responses were significantly higher in major than in minor depressed subjects. There was a significant and positive relationship between L-5-HTP-induced post-DST beta-endorphin and ACTH or cortisol responses. There was a significant and positive relationship between L-5-HTP-induced post-DST beta-endorphin values and the Hamilton Depression Rating Scale (HDRS) score. The results show that the acute administration of L-5-HTP may increase the escape of beta-endorphin secretion from suppression by dexamethasone in major, but not minor, depression.

Adult↗
PubMed1995

An augmented escape of androstenedione from suppression by dexamethasone in melancholia: relationships to intact ACTH and cortisol nonsuppression.

To further examine the association between basal and postdexamethasone (DST) pituitary and adrenal activity in depression, the authors measured intact adrenocorticotropic hormone (ACTH), androstenedione and cortisol, both in baseline and post-DST conditions, in 63 depressed subjects (14 minor, 33 simple major and 16 melancholic subjects). It was found that post-DST androstenedione, cortisol and ACTH values were significantly higher in melancholic than in minor depressed subjects. There were highly significant correlations between plasma androstenedione and ACTH both in baseline and post-DST conditions. The significant intercategory differences in post-DST androstenedione were determined by differences in post-DST ACTH. Basal and post-DST androstenedione values were significantly higher in men than in women and both values were significantly and negatively related to age. There were highly significant, positive relationships between cortisol and ACTH and between cortisol and androstenedione both in baseline and post-DST conditions. The results corroborate our hypotheses that, in depression, pituitary (ACTH) and adrenal (cortisol and androstenedione) hormonal secretion are tightly coupled in post-DST conditions and that the augmented escape of ACTH-target hormones in melancholia is, in part, related to that of pituitary ACTH.

Adrenocorticotropic Hormone↗
PubMed1995

Anterior gastric wall stapling combined with posterior truncal vagotomy in the treatment of duodenal ulcer.

Anterior gastric stapling with posterior truncal vagotomy was examined as an alternative to highly selective vagotomy in the treatment of peptic ulcer disease. A clinical series of 32 patients who underwent the combined procedure is presented; gastric acid output was adequately reduced (basal output by 82 per cent, peak by 64 per cent). Motility changes were temporary and mild. Clinical follow-up, using a modified Visick grading, showed good to excellent results in 21 of 25 patients who could be classified. This procedure is suggested as an appropriate alternative to highly selective vagotomy.

Adult↗
PubMed1995

Effects of serotonin precursors on the negative feedback effects of glucocorticoids on hypothalamic-pituitary-adrenal axis function in depression.

In order to investigate the relationships between brain serotonergic turnover and hypothalamic-pituitary-adrenal (HPA) axis function in unipolar depression, the authors measured intact adrenocorticotropic hormone (ACTH) and cortisol levels in baseline conditions and after combined dexamethasone (1 mg PO) and L-5-hydroxytryptophan (L-5-HTP, 200 mg PO) administration in 13 minor, 17 simple major, and 17 melancholic subjects. L-5-HTP significantly enhanced post-DST ACTH and cortisol secretion in major--but not in minor--depressed subjects. Major depressed subjects with or without melancholia exhibited significantly higher post-DST ACTH and cortisol responses to L-5-HTP than minor depressed subjects. L-5-HTP administration converted some major depressed ACTH or cortisol suppressors into nonsuppressors. L-5-HTP stimulated ACTH or cortisol secretion to the same extent in major depressed HPA-axis suppressors and nonsuppressors. It is concluded that L-5-HTP loading may augment ACTH and, consequently, cortisol escape from suppression by dexamethasone in major but not in minor depressed subjects. The findings show that serotonergic mechanisms modulate the negative feedback of glucocorticoids on central HPA-axis regulation. It is hypothesized that the higher L-5-HTP-induced post-DST HPA-axis hormone responses in major depression reflect upregulated 5-HT2 receptor-driven breakthrough secretion of pituitary ACTH from suppression by dexamethasone.

Adrenocorticotropic Hormone↗
PubMed1995

Immunoradiometric method and electrophoretic system compared for quantifying bone alkaline phosphatase in serum.

Agarose electrophoresis (Isopal, Beckman) and an immunoradiometric assay (IRMA) involving specific monoclonal antibodies (Ostase, Hybritech), two methods for the quantification of serum bone alkaline phosphatase (ALP, EC 3.1.3.1), a marker of osteoblastic activity, were compared in 293 patients: 79 with end-stage renal failure treated with hemodialysis and 214 with malignant disease. Overall correlation between the two methods was good (r = 0.92), except (a) for low values of bone ALP and (b) in some samples with high total liver ALP activity--both due to considerable cross-reactivity of the anti-bone ALP antibodies of the Ostase kit with liver ALP. This interference was not constant and was not evenly distributed across all concentrations of bone ALP. Low bone ALP determined with the IRMA (< or = 5 micrograms/L) was confirmed by electrophoresis (< or = 21 U/L), but bone ALP activity determined by electrophoresis to be low (< or = 21 U/L) was not correlated with the IRMA results. After standardizing our results by computing z-values for bone ALP, delta z (= zOstase - zIsopal) was significantly correlated with liver ALP activity (r = 0.73, P < 0.0001). We conclude that the IRMA for quantifying bone ALP is acceptable as a screening method. However, when high values for bone ALP are found with the Ostase method, confirmation by electrophoresis remains mandatory to rule out cross-reactivity with high amounts of liver ALP. For detecting low bone ALP activities, electrophoresis remains the method of choice.

Alkaline Phosphatase↗
PubMed1994

A further investigation of basal HPT axis function in unipolar depression: effects of diagnosis, hospitalization, and dexamethasone administration.

Hypothalamic-pituitary-thyroid (HPT) axis function was assessed in depressed subjects 1 and 8 days after hospital admission, and after the administration of 1 mg of dexamethasone. Plasma levels of thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were measured by ultrasensitive assays in 16 patients with minor depression, 15 patients with simple major depression, and 13 patients with melancholia. The postdexamethasone adrenocorticotropic hormone (ACTH) (intact 1-39 molecule) and cortisol values were determined. Basal TSH values were significantly lower in melancholic patients than in patients with minor and simple major depression on the day after admission and 1 week later. Basal TSH values determined 1 week after admission were significantly and negatively related to FT4 values and severity of depression. There were no significant differences in basal TSH, FT3, and FT4 values obtained on day 1 and day 8 after hospital admission. Dexamethasone administration had a significant suppressant effect on basal TSH and FT3 values. Patients who failed to suppress cortisol after the dexamethasone suppression test (DST) exhibited significantly less suppression of basal TSH values than did DST cortisol suppressors.

Adrenocorticotropic Hormone↗
PubMed1994

Adrenocorticotropic hormone, beta-endorphin and cortisol responses to oCRH in unipolar depressed patients pretreated with dexamethasone.

1. Corticotropin-releasing hormone (ovine CRH, 100 micrograms intravenous bolus) was given to 63 unipolar depressed inpatients following the 1 mg overnight dexamethasone suppression test (DST). The depressed patients included 18 minor, 24 simple major and 21 melancholic subtypes. 2. Baseline or postdexamethasone plasma levels of intact adrenocorticotropic hormone (ACTH), beta-endorphin/beta-lipotropin (beta END/beta LPH), cortisol, and dexamethasone were measured, as well as the post DST+CRH hormone responses. 3. CRH administration 9.5 hr after dexamethasone resulted in a significant enhancement of ACTH, beta END/beta LPH and cortisol secretion. The post DST+CRH ACTH and beta END/beta LPH- but not cortisol-values exceeded their baseline hormone levels. The post DST+CRH ACTH--but not beta END/beta LPH or cortisol-levels were significantly higher in major depressives compared to minor depressives. The post DST+CRH ACTH and beta END/beta LPH--but not cortisol-levels were significantly higher in DST nonsuppressors than suppressors. The post DST+CRH ACTH levels were significantly and positively related to severity of illness. 4. The results provide evidence that the pathophysiology underlying the abnormal DST+CRH and DST tests in melancholia is localized at the pituitary level and may consist of a CRH-driven breakthrough of corticotropic cell secretion synergized by central and peripheral agents, in conjunction with a decrease in glucocorticoid feedback suppressibility.

Adrenocorticotropic Hormone↗
PubMed1994

Multiple reciprocal relationships between in vivo cellular immunity and hypothalamic-pituitary-adrenal axis in depression.

Major depression is reportedly characterized by increased activity of the hypothalamic-pituitary-adrenal (HPA) axis and by in vivo immune activation. The present study was carried out in order to investigate the relationships between HPA-axis activity and in vivo immune function in depression. Towards this end the following parameters were measured: 24 h urinary cortisol (UC) excretion; basal and post-dexamethasone (DST) plasma cortisol, beta-endorphin/beta-lipotropin (beta END/beta LPH) and dexamethasone concentrations; and leucocyte subsets (i.e. lymphocytes, neutrophils, monocytes, CD4+, CD4+CD45RA+, CD4+CD45RO+, CD8+, CD8+CD57+, CD8+CD57-, HLA-DR+, CD25+ T cells, HLA-DR+, CD19+, CD20+, and CD21+ B cells) both pre- and post-DST. Dexamethasone administration (1 mg orally) induced leucocytosis, lymphocytopaenia, monocytopaenia and neutrophilia. HPA-axis non-suppressors exhibited a relative resistance to the enhancing (e.g. neutrophils) or depressant (e.g. lymphocytes, CD4+ T cells) effects of dexamethasone. There were significant correlations between UC excretion and the number of percentage of lymphocytes, monocytes, CD4+CD45RA+ and CD8+CD57- T cells (negatively) and neutrophils (positively). It is concluded that multiple and complex intertwined relationships between HPA-axis hyperactivity and systemic immune stimulation participate in the pathophysiology or pathogenesis of major depression.

Adult↗
PubMed1994

Ultrasensitive assay for measuring the intact (1-39) ACTH molecule: an asset in depression research.

This study investigates the utility for depression research of an assay for intact (1-39) adrenocorticotropic hormone (ACTH) versus that of a previously employed (i.e., 1-17, 1-24 sequences) ACTH assay. ACTH plasma levels were measured using two different ACTH assays (labeled as intact versus nonintact) in 10 minor and 27 major depressed subjects undergoing the combined dexamethasone suppression (DST) and corticotropin-releasing hormone (CRH) test. Intact--but not nonintact--ACTH values were significantly correlated with the severity of illness. Major depressed subjects exhibited significantly higher post-DST+CRH intact ACTH values than minor depressives, whereas nonintact ACTH values were not significantly different between these groups. Post-DST+CRH intact ACTH values were significantly more closely related to post-DST+CRH cortisol than nonintact ACTH values. It is concluded that the assay of the intact ACTH molecule is an asset in depression research and should replace the previous less specific and sensitive ACTH assays.

Adrenocorticotropic Hormone↗