Effect of BH4 on blood phenylalanine and tyrosine variations in patients with phenylketonuria.

BACKGROUND: In patients with phenylketonuria, stability of blood phenylalanine and tyrosine concentrations might influence brain chemistry and therefore patient outcome. This study prospectively investigated the effects of tetrahydrobiopterin (BH4), as a chaperone of phenylalanine hydroxylase on diurnal and day-to-day variations of blood phenylalanine and tyrosine concentrations. METHODS: Blood phenylalanine and tyrosine were measured in dried blood spots (DBS) four times daily for 2 days (fasting, before lunch, before dinner, evening) and once daily (fasting) for 6 days in a randomized cross-over design with a period with BH4 and a period without BH4. The sequence was randomized. Eleven proven BH4 responsive PKU patients participated, 5 of them used protein substitutes during BH4 treatment. Natural protein intake and protein substitute dosing was adjusted during the period without BH4 in order to keep DBS phenylalanine levels within target range. Patients filled out a 3-day food diary during both study periods. Variations of DBS phenylalanine and Tyr were expressed in standard deviations (SD) and coefficient of variation (CV). RESULTS: BH4 treatment did not significantly influence day-to-day phenylalanine and tyrosine variations nor diurnal phenylalanine variations, but decreased diurnal tyrosine variations (median SD 17.6 µmol/l, median CV 21.3%, p = 0.01) compared to diet only (median SD 34.2 µmol/l, median CV 43.2%). Consequently, during BH4 treatment diurnal phenylalanine/tyrosine ratio variation was smaller, while fasting tyrosine levels tended to be higher. CONCLUSION: BH4 did not impact phenylalanine variation but decreased diurnal tyrosine and phenylalanine/tyrosine ratio variations, possibly explained by less use of protein substitute and increased tyrosine synthesis.

The challenges of managing coexistent disorders with phenylketonuria: 30 cases.

INTRODUCTION: The few published case reports of co-existent disease with phenylketonuria (PKU) are mainly genetic and familial conditions from consanguineous marriages. The clinical and demographic features of 30 subjects with PKU and co-existent conditions were described in this multi-centre, retrospective cohort study. METHODS: Diagnostic age of PKU and co-existent condition, treatment regimen, and impact of co-existent condition on blood phenylalanine (Phe) control and PKU management were reported. RESULTS: 30 patients (11 males and 19 females), with PKU and a co-existent condition, current median age of 14 years (range 0.4 to 40 years) from 13 treatment centres from Europe and Turkey were described. There were 21 co-existent conditions with PKU; 9 were autoimmune; 6 gastrointestinal, 3 chromosomal abnormalities, and 3 inherited conditions. There were only 5 cases of parental consanguinity. Some patients required conflicting diet therapy (n=5), nutritional support (n=7) and 5 children had feeding problems. There was delayed diagnosis of co-existent conditions (n=3); delayed treatment of PKU (n=1) and amenorrhea associated with Grave's disease that masked a PKU pregnancy for 12 weeks. Co-existent conditions adversely affected blood Phe control in 47% (n=14) of patients. Some co-existent conditions increased the complexity of disease management and increased management burden for patients and caregivers. CONCLUSIONS: Occurrence of co-existent disease is not uncommon in patients with PKU and so investigation for co-existent disorders when the clinical history is not completely consistent with PKU is essential. Integrating care of a second condition with PKU management is challenging.

Evaluation of five methods for the interpolation of bad leads in the solution of the inverse electrocardiography problem.

Objective.This study aims to assess the sensitivity of epicardial potential-based electrocardiographic imaging (ECGI) to the removal or interpolation of bad leads.Approach.We utilized experimental data from two distinct centers. Langendorff-perfused pig (n= 2) and dog (n= 2) hearts were suspended in a human torso-shaped tank and paced from the ventricles. Six different bad lead configurations were designed based on clinical experience. Five interpolation methods were applied to estimate the missing data. Zero-order Tikhonov regularization was used to solve the inverse problem for complete data, data with removed bad leads, and interpolated data. We assessed the quality of interpolated ECG signals and ECGI reconstructions using several metrics, comparing the performance of interpolation methods and the impact of bad lead removal versus interpolation on ECGI.Main results.The performance of ECG interpolation strongly correlated with ECGI reconstruction. The hybrid method exhibited the best performance among interpolation techniques, followed closely by the inverse-forward and Kriging methods. Bad leads located over high amplitude/high gradient areas on the torso significantly impacted ECGI reconstructions, even with minor interpolation errors. The choice between removing or interpolating bad leads depends on the location of missing leads and confidence in interpolation performance. If uncertainty exists, removing bad leads is the safer option, particularly when they are positioned in high amplitude/high gradient regions. In instances where interpolation is necessary, the inverse-forward and Kriging methods, which do not require training, are recommended.Significance.This study represents the first comprehensive evaluation of the advantages and drawbacks of interpolating versus removing bad leads in the context of ECGI, providing valuable insights into ECGI performance.

Thyroid function and IVF outcome for different indications of subfertility.

ABSTRACT: Studies evaluating pregnancy outcomes after assisted reproductive treatment (ART) in women with high-normal (2.5-4.5 mIU/L) thyroid-stimulating hormone (TSH) levels are conflicting, possibly due to different patient charactistics and subfertility indications. The aim of this study was to examine the hypothesis that high-normal compared to low-normal TSH levels are associated with adverse implications for pregnancy outcomes in conventional in vitro fertilization (IVF)-treated women. Therefore, we analyzed retrospectively the characteristics and pregnancy outcomes of 949 subfertile women with TSH 0.3-4.5 mIU/L, treated with conventional IVF between January 2008 and March 2012. Demographic and baseline characteristics were compared between groups of patients based on TSH quartiles, using one-way Anova, Kruskal-Wallis ANOVA and chi-square test. Women with high-normal quartile TSH were significantly more likely to be primary subfertile (P = 0.01), with a higher prevalence of unexplained subfertility and with 15% fewer live births after IVF compared to lower TSH quartiles (P = 0.02). In secondary subfertile women with high-normal TSH, male factor subfertility prevailed (P = 0.01), with more live births (P = 0.01). When analyzing primary and secondary subfertile women as one group, these differences failed to be observed, showing no differences in cumulative pregnancy outcomes of IVF between TSH quartiles (I: 0.3-1.21 mIU/L; II: 1.22-1.68 mIU/L; III: 1.69-2.31 mIU/L; IV: 2.32-4.5 mIU/L). In conclusion, primary subfertile women predominate in the high-normal TSH quartile, associated with significantly fewer live births in a subgroup of primary unexplained subfertile women (9%; n = 87/949), while in secondary subfertile women, dominated by male factor subfertility, high-normal TSH is associated with more live births. LAY SUMMARY: Thyroid hormones are required for all cell processes in the body. An underactive thyroid gland, in which insufficient thyroid hormones are produced and thyroid-stimulating hormone (TSH) rises, is associated with a lower chance of pregnancy. It is not yet clear above which TSH level, 4.5 or also 2.5 mIU/L, this lower probability occurs. Therefore, in 949 couples treated with conventional IVF, we examined whether high-normal TSH levels (TSH: 2.5-4.5 mIU/L) compared to low normal TSH levels (0.3-2.5 mIU/L) affect the live birth rate. We found that women who were trying to become pregnant for the first time, especially without any other cause, that is unexplained subfertility, were more likely to have higher TSH levels. These women had a much lower chance of having a baby compared to women with low-normal TSH levels.

Analysis of e-waste recycling behavior based on survey at a Midwestern US University.

The United States lacks a set of unified electronic waste recycling laws, contributing in part to the observed low rate of e-waste recycling behaviors among consumers. Individual factors of consumers contributing to the low recycling rates are not well understood. The objective of this study was to evaluate consumer behaviors, including barriers, surrounding e-waste recycling at a large Midwestern university in the United States. A survey was administered to faculty, graduate students, undergraduate students, and staff to determine their personal recycling habits, knowledge, and beliefs. The results indicate that free access to disposal, lack of consumer knowledge about products and disposal sites, and access to a recycling facility within a reasonable distance are all important factors in consumer decisions. Policy-makers and waste management professionals should focus on promotion of e-waste recycling behaviors through increased access to free or low-cost recycling as well as through the creation of recycling incentives.

Live birth rate after intrauterine insemination is not different between women with lower quartile versus higher quartile normal range thyroid stimulating hormone levels.

STUDY QUESTION: Does lower quartile normal range thyroid stimulating hormone (TSH) compared to higher quartile normal range in women without thyroid hormone substitution affect live birth rate after a complete IUI treatment series? SUMMARY ANSWER: Lower quartile normal range TSH, in women without thyroid hormone substitution, does not affect live birth rate after a complete intrauterine insemination treatment series compared to higher quartile normal range TSH. WHAT IS KNOWN ALREADY: TSH is historically seen as the most sensitive test for thyroid function. Its distribution is right-skewed. Whether the preconceptional upper reference TSH values in subfertile women should be 2.5 or 4.5 mIU/L is under debate. Studies have shown that IUI patients treated with levothyroxine for TSH levels above 2.5 mIU/L show higher pregnancy rates. However, no adverse outcome is associated with untreated high normal TSH levels studied in first IUI cycles. Thyroid peroxidase antibodies have also impaired outcomes in some studies whereas others have shown an effect only in combination with high normal TSH levels. As a subgroup, patients with unexplained infertility showed increased levels of TSH. This article adds to the value of TSH evaluation and fertility outcome in four quartiles and in the context of a completed IUI treatment modus of a maximum of six inseminations. STUDY DESIGN SIZE DURATION: This is a retrospective cohort study in 909 women undergoing 3588 IUI cycles starting treatment between the first of January 2008 and the first of March 2012. PARTICIPANTS/MATERIALS SETTING METHODS: Women aged 22-45 years with TSH 0.3-4.5 mIU/L without thyroid hormone substitution were included at Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands, an Iodine-sufficient area. The primary endpoint was live birth. Clinical pregnancy, pregnancy loss and ongoing pregnancy were secondary endpoints. Logistic regression was used with the natural logarithm of TSH as a continuous predictor. Chi-square tests and logistic regression were used to compare groups of patients based on TSH values in four quartile TSH groups (0.3-1.21 mIU/L; 1.22-1.75 mIU/L; 1.76-2.34 mIU/L; 2.35-4.5 mIU/L) on basic characteristics and on the endpoints while adjusting for confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Analysis with the natural logarithm of TSH as a continuous variable showed no association with live birth, pregnancy chance or pregnancy loss. There were no differences in any of the outcomes across the quartile TSH level ranges after regression analysis before and after adjusting for age, BMI, use of alcohol, tobacco, use or gonadotrophins, sperm count, diminished ovarian reserve, unexplained infertility and primary or secondary subfertility.The distribution of primary and secondary subfertility and smoking characteristics were remarkably different across the four groups, with proportionally the lowest prevalence of primary subfertility and the highest rate of smoking in the lowest TSH group (0.3-1.20 mIU/L). LIMITATIONS REASONS FOR CAUTION: Unknown values of free thyroxine and thyroid peroxidase antibodies, as well as the retrospective character of the study, limit the clinical interpretability. WIDER IMPLICATIONS OF THE FINDINGS: TSH in the highest quartile range (2.35-4.5 mIU/L) in subfertile women preceding IUI is not associated with a lower live birth rate or rate of clinical and ongoing pregnancy, or with loss of pregnancies, compared to subfertile women with TSH in the lower three quartile groups after complete intrauterine insemination treatment. STUDY FUNDING/COMPETING INTERESTS: The department of Obstetrics and Gynaecology, division of Reproductive Medicine, and of Internal Medicine, division of Endocrinology provided support. There are no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Psychosexual functioning of childhood cancer survivors.

PURPOSE: The objective of the study is to explore psychosexual functioning and its relationship with quality of life in survivors of cancer in childhood. METHODS: Sixty childhood cancer survivors completed two questionnaires: psychosexual and social functioning questionnaire and MOS-SF-36. RESULTS: Psychosexual problems were frequent. About 20% of the survivors felt a limitation in their sexual life due to their illness. Older survivors (> or =25 years) had significantly less experience with sexual intercourse than their age-matched peers in the Dutch population (p = 0.010). Survivors treated in adolescence had a delay in achieving psychosexual milestones compared with those treated in childhood: dating (p<0.025), touching under clothes (p<0.025), masturbation (female) (p<0.05) and sexual intercourse (p<0.025). No differences were found for sexual fantasies, kissing, masturbation (male) and oral sex. The total survivor group appraised their quality of life as less positive than their Dutch peers for the subscales of general and mental health (both p<0.001), physical and social functioning (p<0.01; p<0.001), bodily pain and vitality (both p<0.001). However, quality of life was not more affected adversely in survivors with psychosexual problems compared with survivors without these problems. CONCLUSION: In this cohort of childhood cancer survivors, psychosexual problems were frequent. Treatment in adolescence is a risk factor for a delay in psychosexual development.

Effects of ECG Signal Processing on the Inverse Problem of Electrocardiography.

The inverse problem of electrocardiography is ill-posed. Errors in the model such as signal noise can impact the accuracy of reconstructed cardiac electrical activity. It is currently not known how sensitive the inverse problem is to signal processing techniques. To evaluate this, experimental data from a Langendorff-perfused pig heart (n=1) suspended in a human-shaped torso-tank was used. Different signal processing methods were applied to torso potentials recorded from 128 electrodes embedded in the tank surface. Processing methods were divided into three categories i) high-frequency noise removal ii) baseline drift removal and iii) signal averaging, culminating in n=72 different signal sets. For each signal set, the inverse problem was solved and reconstructed signals were compared to those directly recorded by the sock around the heart. ECG signal processing methods had a dramatic effect on reconstruction accuracy. In particular, removal of baseline drift significantly impacts the magnitude of reconstructed electrograms, while the presence of high-frequency noise impacts the activation time derived from these signals (p<0.05).

Reduction of Effects of Noise on the Inverse Problem of Electrocardiography with Bayesian Estimation.

To overcome the ill-posed nature of the inverse problem of electrocardiography (ECG) and stabilize the solutions, regularization is used. Despite several studies on noise, effect of prefiltering of ECG signals on the regularized inverse solutions has not been explored. We used Bayesian estimation for solving the inverse ECG problem with and without applying various prefiltering methods, and evaluated our results using experimental data that came from a Langendorff-perfused pig heart suspended in a human-shaped torso-tank. Epicardial electrograms were recorded during RV pacing using a 108-electrode array, simultaneously with ECGs from 128 electrodes embedded in the tank surface. Leave-one-beat-out protocol was used to obtain the prior probability density function (pdf) of electro-grams and noise statistics. Noise pdf was assumed to be zero mean-Gaussian, with covariance assumptions: a) independent and identically distributed (noi-iid), b) correlated (noi-corr). Reconstructed electrograms and activation times were compared to those directly recorded by the sock for 3 beats selected from the recording. Noi-corr is superior to noi-iid when the training set is a good match to data, but for applications requiring activation time derivation, careful selection of preprocessing methods, in particular to adequately remove high-frequency noise, and an appropriate noise model is needed.

Long-term effects of radioiodine treatment on salivary gland function in adult survivors of pediatric differentiated thyroid carcinoma.

Pediatric differentiated thyroid cancer (DTC) is a rare disease. Initial treatment of DTC consists of a (near) total thyroidectomy and radioactive iodine (131I) therapy. Previous studies in adults showed that 131I treatment may result in a reduced salivary gland function. Studies regarding salivary gland function in children treated for DTC are sparse. Our aim was to assess long-term effects of 131I treatment on salivary gland function in survivors of pediatric DTC. Methods: In a nationwide cross-sectional study, salivary gland function of patients treated for pediatric DTC between 1970 and 2013 (>5 years after diagnosis, ≥18 years old at time of evaluation) was studied. Salivary gland function was assessed by sialometry, sialochemistry and a xerostomia inventory. Salivary gland dysfunction was defined as unstimulated whole saliva flow ≤0.2mL/min and/or a stimulated whole saliva flow ≤0.7 mL/min. Results: Sixty-five patients (median age at evaluation 33 [IQR, 25-40] years, 86.2% female, median follow-up period 11 [IQR, 6-22] years) underwent 131I treatment. Median cumulative 131I activity was 5.88 [IQR, 2.92-12.95] GBq, 47.7% underwent multiple 131I administrations. Salivary gland dysfunction was present in 30 (47.6%) patients. Levels of amylase and total protein in saliva were reduced. Moderate to severe xerostomia was present in 22 (35.5%) patients. Stimulated salivary secretion was lower and severity of xerostomia complaints higher in patients treated with higher cumulative 131I activity. Conclusion: In survivors of pediatric DTC, clinically significant salivary gland dysfunction was found in 35.5% and was related to the cumulative 131I activity of the treatment.

Prevention of depression in subclinically depressed adults: follow-up effects on the 'Coping with Depression' course.

BACKGROUND: People with subclinical depressive symptoms are at increased risk of depressive disorder, little is known on the prevention of depressive disorder in this population. This study evaluates the long-term preventive effects of an effective depression treatment, the Coping with Depression (CWD) course. This paper describes the effect of the CWD course on the incidence of depressive episodes and depressive symptoms, and explores whether the initial level of symptoms and gender has differential intervention effects. METHODS: Participants (N=104) were adults with subclinical depressive symptoms, who were randomly assigned to either a preventive group course condition, the 'Coping with Depression' course, or to an assessment-and-advice-only control group condition. Follow-up results were measured 6 and 12 months after completion of the course. RESULTS: The CWD course showed to be effective in preventing depressive symptomatology but there was no evidence that the course prevented depressive disorder. 25% of the control group and 27.3% of the course group developed a depressive disorder within a year. Initial depressive symptomatology moderated the outcomes: only participants with low initial symptomatology appeared to benefit in the long term from course participation. CONCLUSIONS: The CWD course is effective as a treatment for subclinical depression. Preventive effects are restricted to participants with initially low depression levels. Therefore, this subgroup should be targeted in future depression-prevention practices and in future prevention studies.

Differential effects of a perioperative hyperinsulinemic normoglycemic clamp on the neurohumoral stress response during coronary artery surgery.

BACKGROUND: Hyperglycemia in patients undergoing coronary artery bypass grafting (CABG) is associated with adverse outcome. Although insulin infusion strategies are increasingly used to improve outcome, a pathophysiological rationale is currently lacking. The present study was designed to quantify the effects of a perioperative hyperinsulinemic normoglycemic clamp on the neurohumoral stress response during CABG. METHODS: Forty-four nondiabetic patients, scheduled for elective CABG, were randomized to either a control group (n = 22) receiving standard care or to a clamp group (n = 22) receiving additionally a perioperative hyperinsulinemic (regular insulin at a fixed rate of 0.1 IU.kg(-1).h(-1)) normoglycemic (plasma glucose between 3.0 and 6.0 mmol.liter(-1)) clamp during 26 h. We measured the endocrine response of the hypothalamus-pituitary-adrenal (HPA) axis, the sympathoadrenal axis, and glucagon, as well as plasma glucose and insulin at regular intervals from the induction of anesthesia at baseline through the end of the second postoperative day (POD). RESULTS: There were no differences in clinical outcome between the groups. In the control group, hyperglycemia developed at the end of surgery and remained present until the final measurement point on POD2, whereas plasma insulin levels remained unchanged until the morning of POD1. In the intervention group, normoglycemia was well maintained during the clamp, whereas insulin levels ranged between 600 and 800 pmol.liter(-1). In both groups, plasma ACTH and cortisol increased from 6 h after discontinuation of cardiopulmonary bypass onward. However, during the clamp period, a marked reduction in the HPA axis response was found in the intervention group, as reflected by a 47% smaller increase in area under the curve in plasma ACTH (P = 0.035) and a 27% smaller increase in plasma cortisol (P = 0.002) compared with the control group. Compared with baseline, epinephrine and norepinephrine increased by the end of the clamp interval until POD2 in both groups. Surprisingly, the area under the curve of epinephrine levels was 47% higher (P = 0.026) after the clamp interval in the intervention group as compared with the control group. CONCLUSION: A hyperinsulinemic normoglycemic clamp during CABG delays and attenuates the HPA axis response during the first 18 h of the myocardial reperfusion period, whereas after the clamp, plasma epinephrine is higher. The impact of delaying cortisol responses on clinical outcome of CABG remains to be elucidated.

[The syndrome of inappropriate antidiuretic hormone secretion (SIADH) during treatment with the antipsychotic agents haloperidol and quetiapine]. / Het syndroom van inadequate secretie van antidiuretisch hormoon (SIADH) tijdens het gebruik van de antipsychotica haloperidol en quetiapine.

A 45-year-old man with paranoid schizophrenia repeatedly developed hyponatraemia due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH), both after treatment with haloperidol and after taking quetiapine. This side effect did not occur subsequently during clozapine treatment. SIADH has been described in connection with almost all psychotropic drugs. Since the risk of developing SIADH is increased with increasing age, comorbid somatic disorders and polypharmacy, and the mean age of the psychiatric patient will further increase in the years to come, the physician should be alert to the risk factors and the clinical symptoms of disturbances in water balance; moreover, the proper differential diagnostic deliberations should be made. In case of increased risk, it is recommended to monitor the serum sodium during the first 2-4 weeks of pharmacotherapy.

Protein substitutes for phenylketonuria in Europe: access and nutritional composition.

BACKGROUND/OBJECTIVES: Protein substitutes (PS) are an essential component in the dietary management of phenylketonuria (PKU). PS are available as phenylalanine-free amino-acid mixtures (AAM), glycomacropeptide-based PS (GMP) and large neutral amino acids (LNAA). There is a lack of information regarding their availability in different countries and comparison of their nutritional composition is limited. The objectives of this study were to identify the number of PS available in different European countries and Turkey and to compare their nutritional composition. SUBJECTS/METHODS: Members of the European Nutritionist Expert Panel on PKU (ENEP) (Portugal, Spain, Belgium, Italy, Germany, Netherlands, United Kingdom, Denmark and Turkey) provided data on PS available in each country. The nutritional composition of PS available in Portugal was analyzed. RESULTS: The number of PS available in each country varied from 30 (Turkey) to 105 (Germany), with a median of 64. GMP was available only in Portugal, whereas LNAA was an option in Portugal, Italy, Turkey and Denmark. Some PS were designed for weaning. Many PS did not contain added fat and fiber. GMP contained the highest carbohydrate (CHO) and energy content as well as higher LNAA content compared with AAM. Only one AAM contained added fructo-oligosaccharides and galacto-oligosaccharides. AAM designed for the first year of life had the highest CHO, fat and LNAA contribution. Liquid AAM had lower CHO and fat contents compared with powdered AAM, but contained higher LNAA. CONCLUSIONS: There was widely dissimilar numbers of PS available in different countries. Nutritional composition of different PS was variable and should be considered before prescription.

A genotypic and histopathological study of a large Dutch kindred with hyperparathyroidism-jaw tumor syndrome.

Familial primary hyperparathyroidism is the main feature of 2 familial endocrine neoplasia syndromes: multiple endocrine neoplasia type 1 (MEN 1) and hyperparathyroidism-jaw tumor syndrome (HPT-JT). The latter is a recently described syndrome that has been associated with ossifying fibroma of the jaw and various types of renal lesions, including benign cysts, Wilms' tumor, and hamartomas. To further illustrate the natural history of this syndrome, we describe a large, previously unreported Dutch kindred in which 13 affected members presented with either parathyroid adenoma or carcinoma; in 5 affected individuals, cystic kidney disease was found. Additionally, pancreatic adenocarcinoma, renal cortical adenoma, papillary renal cell carcinoma, testicular mixed germ cell tumor with major seminoma component, and Hürthle cell thyroid adenoma were also identified. Linkage analysis of the family using MEN1-linked microsatellite markers and mutation analysis excluded the involvement of the MEN1 gene. Using markers from the HPT-JT region in 1q2531, cosegregation with the disease was found, with a maximum logarithm of odds score of 2.41 obtained for 6 markers using the most conservative calculation. Meiotic telomeric recombination between D1S413 and D1S477 was identified in 3 affected individuals, and when combined with previous reports, delineated the HPT-JT region to 14 centimorgan. Combined comparative genomic hybridization and loss of heterozygosity data revealed complex genetic abnormalities in the tumors, suggesting different possible genetic mechanisms for the disease. In conclusion, we report a family with hyperparathyroidism linked to chromosome 1q, and exhibiting several types of renal and endocrine tumors that have not been previously described.

Probable risk of tumour induction after retro-orbital irradiation for Graves' ophthalmopathy.

Retrobulbar irradiation for Graves' ophthalmopathy is considered as a safe treatment and has recently been recommended as the initial treatment for patients with moderately severe eye problems. However, calculations using risk factors presently known reveal a theoretical risk of radiation-induced cancer of 1.2%. Therefore, the authors suggest that this treatment should be reserved for the elderly patient, for example above the age of 40-50 years.

Expression of zeta molecules is decreased in NK cells from HIV-infected patients.

Cytolysis by natural killer (NK) cells is impaired in HIV infection. We investigated whether the expression of zeta (zeta) molecules, essential elements of signalling initiated upon ligation of, e.g., CD16, is reduced and if so, whether this reduction could be involved in defective cytolysis. FACS analysis revealed significantly lower levels of zeta in NK cells from AIDS patients compared to cells from patients without AIDS and healthy controls. CD16-dependent cytolysis by NK cells correlated with expression of zeta molecules and CD16, the latter possibly related to zeta expression. No correlation was observed between CD16-independent cytolysis and zeta expression. Reduced expression of zeta molecules by NK cells from HIV-infected patients thus correlates with disease progression and may, in part, explain the defective cytolysis by these cells.

Treatment of amiodarone-induced hypothyroidism with potassium perchlorate.

The antiarrhythmic drug, amiodarone, induces thyroid dysfunction, which is potentially dangerous in cardiac patients. After discontinuation of the drug it takes several months before euthyroidism is restored. The potent antithyroid drug, potassium perchlorate (KClO4), is used successfully to treat amiodarone-induced thyrotoxicosis, but it is less well known as potential treatment in amiodarone-induced hypothyroidism. In this case report we describe the successful use of two courses of KClO4 treatment in a cardiac patient with severe amiodarone-induced hypothyroidism. The mechanisms responsible for the amiodarone-induced hypothyroidism and rationale for the use of KClO4 in this condition are discussed.

Macronodular adrenocortical hyperplasia in a postmenopausal woman.

This case report describes the diagnosis of Cushing's syndrome due to macronodular adrenal hyperplasia in an elderly woman who presented with fatigue, muscle weakness and oedema, and recent excessive bruising. Long-standing disease and comorbidity precluded adrenalectomy. Despite treatment with metyrapone and diuretics, the patient died after two months hospitalisation. Postmortal examination revealed overexpression of luteinising hormone (LH) receptors in the adrenal glands, suggesting that the postmenopausal rise in LH may have a role in adrenal hyperplasia and hypercortisolism.

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin or 2,2',4,4',5,5'-hexachlorobiphenyl on vitamin K-dependent blood coagulation in male and female WAG/Rij-rats.

Newborns are susceptible to hemorrhages (hemorrhagic disease of the newborn or HDN) due to vitamin K deficiency. Induction of cytochrome P450 in the fetal liver by maternal anticonvulsant therapy such as phenobarbital or phenytoin is considered to be a major cause. An observed increase in late hemorrhagic disease (LHD) in breast fed neonates gave rise to the hypothesis that PCBs and dioxins, P450-inducing contaminants present in human milk, might effect vitamin K-dependent blood coagulation. This hypothesis was studied in rats. Administration of a single oral dose of 0.003, 0.03, 0.3, 3 or 30 nmol 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) per kg bodyweight or 0.75, 4, 20, 100 or 500 micromol 2,2',4,4',5,5'-hexachlorobiphenyl/kg bw (HxCB) to female and male rats resulted in dose-related reductions of the vitamin K-dependent coagulation factor VII. The highest factor VII reduction in female rats was 44%, observed after TCDD exposure. The Lowest Observed Adverse Effect Level (LOAEL) of TCDD on female factor VII levels was 0.3 nmol/kg bw (96 ng/kg). There was a significant inverse correlation between Factor VII levels and induction of hepatic ethoxyresorufin O-deethylating (EROD) activity, reflecting CYP1A1, and total P450 content. HxCB had no effect on female coagulation factors. In contrast, in male rats only exposure to HxCB, which induces mainly CYP2B1 and 2B2, decreased both coagulation factors dramatically up to 88%. The LOAEL of HxCB on factor VII in male rats was 100 micromol/kg bw (36 mg/kg). In general, effects on coagulation factors in male rats exceeded those in females. In addition, sex-dependent differences of TCDD and HxCB were observed on the hepatic vitamin K cycle enzyme activities in female and male rats. Vitamin K-dependent (gamma-glutamyl carboxylase activity was mainly induced in female rats; 2.3-fold in the highest dose group of TCDD. In male rats only vitamin K 2,3-epoxide reductase (KO-reductase) activity was induced 1.7-fold by the highest dose of HxCB. KO-reductase activity in female rats was also increased by TCDD, however, less pronounced than the carboxylase activity. Concluding, the hepatic vitamin K cycle still functions and is not blocked by TCDD or HxCB, thus explaining the observed reduction in factor VII. Finally, the possible role of P450 in vitamin K deficiency is discussed. Based on these results it is suggested to investigate the possible role of PCBs and dioxin-like compounds in LHD in more detail.