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Biomedical subjects

J Faber

Publications and source records attributed to J Faber.

At least 73 records · Page 4Linked to original sources

Influence of meal composition on postprandial peripheral plasma concentrations of vasoactive peptides in man.

In a randomized cross-over study healthy non-obese male human subjects received standardized isocaloric, isovolumetric meals consisting of either carbohydrate, protein or fat and a non-caloric control meal consisting of an equal volume of water. Peripheral venous plasma concentrations of calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and peptide YY (PYY) were measured pre- and postprandially. Plasma CGRP concentrations were lowered following the protein meal and following the fat meal, but remained unaltered after carbohydrate or water ingestion. Plasma VIP concentrations increased slightly following the carbohydrate meal and following water loading. The PYY concentrations increased after the protein and the carbohydrate meal and a slight rise was observed following fat ingestion. Water loading did not affect the plasma level of PYY. We conclude that the postprandial peripheral plasma concentrations of CGRP, VIP and PYY are dependent on the caloric meal composition. The VIP, but not the CGRP and PYY concentrations seem to be influenced by gastric distension. The physiological significance of the postprandial alterations in peripheral concentrations of these peptides is at present uncertain.

Adult↗

"Epileptosis"--a syndrome or useless speculation?

102 patients were divided into 3 groups: epileptics, psychotics and epileptics with psychotic symptoms. All had long been monitored for a number of clinical and laboratory parameters. Though different in many respects, all share states of sudden dysphoria, cacophoria, panic anxiety, horror, and EEG (stereo-EEG, too) signs of epileptic or other gross anomalies, often correlated to those affective disorders. Attacks of dysphoria, epilepsy, and psychosis come spontaneously and in response to biological (hypoglycemia, sleep deprivation, alcohol, menses) or psychosocial stimulation (agitation, quarrels, fear of redundancy, psychic trauma). These states (attacks, dysphoria, "neurotic" or even psychotic episodes) often provoke one another. -Calling this syndrome epileptosis, we believe its mechanism is due to lesions of the limbic and brainstem modulation systems. At the start of the process there is an epileptic focus in the amygdalo-hippocampal complex (AHC) which in itself can trigger simple or complex partial paroxysm but also-by means of electric stimulation of the AHC-states of dysphoria, anxiety, and psychotic hallucinations. Besides, a form of pathological learning develops in premorbid "hypersensitive" personality which can be put down to associative learning and to Overton's phenomenon of "state-dependent retention of learned responses". This may give rise to mutual stimulation where epileptic focal activity in AHC can provoke dysphoria while an external psychosocial situation can trigger epileptic activity there, too (AHC). Since there need not always be mydriasis (though other vegetative signs such as tachycardia, tachypnoea, nausea, blush and others are frequent) or unconsciousness, and some psychomotor manifestations may be out of the ordinary, and scalp EEG may be normal, such patients are often regarded as "hysterics" or malingerers.

Adult↗

Influence of porosity on the mechanical resistance of hydroxyapatite ceramics under compressive stress.

Calcium phosphate ceramics are biocompatible and may develop interactions with human living bone tissues. They are used clinically on the surface of orthopaedic implants to improve primary fixation or in the form of porous blocks. Their brittleness is often advanced as a limitation of their common clinical use. In order to study the influence of porosity on the mechanical strength of calcium phosphate ceramics, we have tested 150 cylindrical hydroxyapatite samples with open porosity. The total porous volume of the ceramics has been varied from 20% to 60% and the pore size from 5 microns to 400 microns. The result indicates that not only total porosity but also pore size can influence compressive strength, which is in good agreement with theoretical work. After mathematical treatment of the results, the experiments have been modelled in the form of a polynomial equation which can be used to predict and optimize mechanical strength. Moreover, this work supports the fact that compressive strength of controlled open porosity implants can be comparable with that of cancellous or cortical human bone, and suggests that porosity should be fitted to clinical application.

Ceramics↗

Primary haemostasis in thyroid disease.

OBJECTIVES: There have been reports on a bleeding tendency in hypothyroidism resembling von Willebrand's disease. The aim of the present study was to investigate whether altered primary haemostasis is a general phenomenon in thyroid disease. DESIGN/SETTING: A total of 10 patients with hyperthyroidism and nine patients with hypothyroidism were studied at diagnosis, and during treatment with carbimazole or L-thyroxine, respectively, when euthyroidism had been achieved. RESULTS: In untreated hypothyroidism, template bleeding time was prolonged (median 9.3 min, range 3.8-20.0 min) compared to that in controls (median 4.0 min, range 3.0-6.0 min; P < 0.05), whereas maximal agglutination velocity induced by ristocetin was decreased (38% min-1, range 4-52% min-1 vs. 70% min-1, range 60-81% min-1, P < 0.05). The level of von Willebrand factor antigen in plasma from hypothyroid patients was less than half of the value in hyperthyroid patients. This difference disappeared after euthyroidism was achieved. CONCLUSIONS: We found that changed primary haemostasis is a general feature of hypothyroidism, and that it is resolved after levothyroxine treatment.

Adult↗

Scintigraphic evaluation of esophageal transit and gastric emptying in familial dysautonomia.

Gastroesophageal dysfunction is a major cause of morbidity and mortality in patients with familial dysautonomia (FD). Most studies evaluating esophageal and gastric function in FD patients are either insensitive or invasive. Thus we have used a "milk" scan to quantitate abnormalities in esophageal transit and gastric emptying, while searching for gastroesophageal reflux and aspiration in these patients. The quantitative scintigraphic evaluation was performed in 35 patients with FD, 10 of whom were studied after fundoplication, pyloroplasty and gastrostomy. A prolonged esophageal transit time, ranging from 8 s to more than 60 s duration, was demonstrated in 11 patients. Gastroesophageal reflux was detected in 26 patients. In 16 patients delayed gastric emptying ranging from 63-94% was detected at 30 min, and in 13 patients delayed emptying ranging from 37-86% was observed at 120 min. Pulmonary aspiration was detected in 8 non-operated patients, four of whom had abnormal gastric emptying. The scintigraphic analysis of both esophageal transit and gastric emptying in familial dysautonomia is presented, and its role in evaluation and management of these patients discussed.

Adolescent↗

Acute changes in thyroid volume and function following 131I therapy of multinodular goitre.

OBJECTIVE: Many textbooks claim that radioiodine (131I) treatment should be given with care to a goitre with substernal extension, for fear of acute swelling of the gland and thus respiratory problems. Since 131I is used increasingly in the treatment of non-toxic as well as toxic goitre we have evaluated the acute changes in thyroid volume following 131I therapy. DESIGN: Evaluation of potential acute changes in thyroid volume and function after 131I treatment in patients with non-toxic goitre treated because of compression symptoms or for cosmetic reasons, as well as in patients with toxic goitre. PATIENTS: Out-patients with multinodular goitre, either non-toxic (n = 20) or toxic (n = 10). Excluded were patients with a substernal goitre. MEASUREMENTS: Ultrasonically determined thyroid volume and standard thyroid function variables were investigated before and 2, 7, 14, 21, 28 and 35 days after treatment. RESULTS: In non-toxic goitres the thyroid volume did not increase significantly, the maximum increase in the median volume being 4% on day 7. Serum levels of free T3 and free T4 indices increased by 20% (day 7) and 13% (day 14) (P = 0.002), respectively. Likewise thyroid volume in toxic nodular goitre did not change significantly after 131I treatment (maximum median increase was 2%). None of the patients presented symptoms of tracheal compression. CONCLUSIONS: 131I treatment of non-toxic as well as toxic multinodular goitre does not seem to increase thyroid volume.

Adult↗

Changes in bone mass during prolonged subclinical hyperthyroidism due to L-thyroxine treatment: a meta-analysis.

L-Thyroxine (L-T4) in the treatment of thyroid disease resulting in reduced serum thyrotropin (TSH) has been associated with reduced bone mass and thus the potential risk of premature development of osteoporosis. However, several recent studies have failed to show such a detrimental effect. These disagreements are probably due to only a small number of patients taking part in each study, decreasing the change of finding significant differences and increasing the risk of missing a real difference (type 1 and 2 errors, respectively). We therefore performed a meta-analysis on the available papers (N = 13), in which bone mass was measured in the distal forearm, femoral neck or lumbar spine in a cross-sectional manner in women with suppressed serum TSH due to L-T4 treatment and in a control group. The women were divided according to their pre- and postmenopausal state, because preserved estrogen production plays a protective role against irreversible bone loss. Based on the number of measurements performed on the different sites of the skeleton, a theoretical bone composed of 30.4% distal forearm, 28.8% femoral neck and 40.8% lumbar spine could be constructed in premenopausal women (441 measurements). A premenopausal woman at an average age of 39.6 years and treated with 164 micrograms L-T4/day for 8.5 years, leading to suppressed serum TSH, had 2.67% less bone mass than controls (NS), corresponding to an excess annual bone loss of 0.31% after 8.5 years of treatment (NS). The risk of not detecting an excess bone loss of at least 1% per year (type 2 error) was p < 0.15.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Bone metabolism in premenopausal women with nontoxic goiter and reduced serum thyrotropin levels.

OBJECTIVE: To study whether premenopausal women with nontoxic goiter, but reduced serum TSH as a sign of spontaneous subclinical hyperthyroidism have decreased bone mass or other indications of increased bone turnover. DESIGN AND SUBJECTS: In a cross-sectional study, bone mass measurements were performed in the distal forearm and the lumbar spine in 11 premenopausal women with nontoxic goiter and a stable reduction in serum TSH (median (range) 8 months (6-108 months)), and in 22 matched controls. In a longitudinal study, measurements were repeated every 3 months for a maximum period of 2 years in 9 of the patients (6 completed 9 months, 4 completed 2 years follow-up). RESULTS: Serum TSH in the patients were (median (range)) 0.025 mU/l (< 0.005-0.256 mU/l). Patients had a bone mineral content of the distal forearm and a bone mineral density of the lumbar spine similar to those of controls, medians of controls: 98.4% and 93.8%, respectively. The risk of a type 2 error for over-looking a 10% difference was 2% for the distal forearm and 20% for the spine. TSH correlated negatively with marginal significance (p < 0.10) with markers of bone turnover: plasma osteocalcin, serum alkaline phosphatase, and fasting urinary hydroxyproline corrected for creatinine, although all patients had absolute values of these parameters within normal range. During follow-up bone mass measurements did not tend to decrease, but serum alkaline phosphatase and fasting urinary hydroxyproline showed increasing trends (p < 0.05). CONCLUSIONS: Premenopausal women with nontoxic goiter and reduced serum TSH do not seem to have reduced bone mass but seem to demonstrate signs of increased bone turnover.

Adult↗

[Comparison of the effectiveness of prostaglandin E2 gel in evening and morning induction of labor].

100 women participated in an open randomised study. 50 of them received 0.5 mg PGE2 in 2.5 ml Triacetin gel (Prepidil) intracervically in the morning (6.00 a.m.) and 50 at night (10.00 p.m.). The success rate was 74% (37 of 50) in the treatment group of the night compared with 52 (26 of 50) in the group of morning labor induction. A second dose after 8 hours was necessary in 26% (13 of 50) in the night group and in 48% (24 of 50) of the morning labor induction. Labor induction failed completely in 32% of the morning and in 12% of the night group. The induction time for contractions was 2 hours shorter after night labor induction, in primiparae the duration of first stage was 2 hours shorter but in multiparae there was no difference between the groups. There was also no difference in intrapartum and postpartum complications between the groups. In conclusion the induction of labor with intracervical PGE2 at night seems to be more effective without increasing the rate of complications.

Administration, Intravaginal↗

Free thyroxine measured in undiluted serum by dialysis and ultrafiltration: effects of non-thyroidal illness, and an acute load of salicylate or heparin.

In vitro dilution of serum during processing of a free T4 assay explains to some extent the divergent results obtained in non-thyroidal illness. If serum from such patients contains low affinity T4 protein binding inhibitors, as has been suggested, in vitro dilution will result in spuriously reduced serum free T4 measurements. If these inhibitors cross the dialysis membrane in an equilibrium dialysis assay, their inhibitory effect will be weakened, and in vitro free T4 levels will decrease, even in undiluted serum. In contrast, ultrafiltration methods on undiluted serum seem accurate. We have compared a new, commercially available dialysis technique with an in-house ultrafiltration method for free T4 measurements in undiluted serum. Control subjects (n = 41) had 14% higher free T4 (P < 0.02) by ultrafiltration. Non-thyroidally ill patients not receiving glucocorticoids or dopamine (n = 54) had unaltered free T4 levels, 28.4 +/- 10.3 pmol/l (dialysis) and 31.0 +/- 10.3 pmol/l (ultrafiltration). Dopamine infusion in somatic ill patients (n = 11) resulted in reduced free T4 in both assays but only significantly for dialysis, and subjects with familial dysalbuminemic hyperthyroxinemia (n = 8) had unaltered free T4 levels in both assays. Salicylate (1.5 g) given orally 09:00 h. (n = 5) resulted within 30 min, in increased (P < 0.01) free T4 as measured by both techniques, although more pronounced and sustained as measured by ultrafiltration. Serum TSH decreased concomitantly (P < 0.01). These findings were confirmed when salicylate was administered at 13:00 h. (n = 8). The dialysis procedure resulted in a decrease in serum salicylate of 14% (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Calcitonin gene-related peptide in small cell lung carcinomas.

OBJECTIVE: Calcitonin gene-related peptide (CGRP) is a regulatory peptide encoded by the calcitonin gene. CGRP is expressed in increased amounts by the cells of medullary thyroid carcinomas and has been demonstrated by immunohistochemistry to occur in neuroendocrine cells and nerve fibres of lung tissue. MEASUREMENTS: Serum CGRP levels were measured in patients with small cell lung carcinomas before treatment (n = 74) and immediately before the second course of chemotherapy (n = 30). In-situ hybridization and immunohistochemistry were performed on tumour tissue and CGRP was extracted from two tumours and characterized by gel chromatography and high pressure liquid chromatography. RESULTS: Serum CGRP levels were elevated in small cell lung carcinomas when compared with healthy controls of similar age and sex (median values 55.0 vs 36.6 pmol/l, P < 0.001), and 27% had levels above the upper normal range. Serum CGRP levels decreased following the initial course of chemotherapy (P < 0.05) but remained elevated when compared to the controls (P < 0.001). In-situ hybridization for CGRP mRNA was positive in three of 17 tumours and immunohistochemistry was positive in seven of 31 tumours investigated. CGRP immunoreactivity extracted from two tumours was characterized by gel chromatography and high pressure liquid chromatography. A major part of the immunoreactivity was demonstrated to represent the intact molecule. CONCLUSIONS: We found that patients with small cell lung carcinomas had elevated concentration of serum calcitonin gene-related peptide but only 27% had values above the upper normal range. Serum CGRP is therefore of limited value as a tumour marker. Intact CGRP can be extracted from tumour tissue, but in-situ hybridization and immunohistochemistry showed positive reactions in only a few of the tumours investigated. The elevated serum CGRP levels are therefore likely to be largely of extratumoral origin.

Adult↗

Nuclear 3,5,3'-triiodothyronine receptor binding in mononuclear blood cells from patients with malignant blood diseases and small cell carcinoma of the lung.

We have previously demonstrated enhanced daily turnover of thyroid hormones in patients with hypermetabolic symptoms due to malignant haematologic disorders or small cell carcinoma of the lung. We hypothesized that some of these symptoms might be due to enhanced peripheral effects of T3. We therefore studied the nuclear T3 receptor binding in circulating mononuclear blood cells in 5 patients with malignant haematologic disorders, 5 with untreated small cell carcinoma of the lung, and 11 healthy controls. Maximal binding capacity of T3 (MBC) was increased 2.5 times in the diseased patients, (median (range)) 110 fmol/mg DNA (75-519) in the haematologic group (p < 0.01), 106 fmol/mg DNA (47-490) (p < 0.10) in small cell carcinoma patients, as compared to 43 fmol/mg DNA (26-94) in controls. The affinity constant Ka of bound T3 was reduced to one-third in the diseased patients. No differences were found between serum thyroid hormone or TSH levels. It is hypothesized, that previously demonstrated enhanced turnover of thyroid hormones in these states of disease might in part be due to increased peripheral consumption of thyroid hormones, including enhanced receptor binding of T3.

Carcinoma, Small Cell↗