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We screened for PDHA1 mutations in 40 patients with biochemically demonstrated PDHc deficiency or strong clinical suspicion, and found changes with probable pathological significance in 20. Five patients presented new mutations: p.A169V, c.932_938del, c.1143_1144 ins24, c.1146_1159dup and c.510-30G> A, this latter is a new undescribed cause of exon 6 skipping. Another four mutations have been found, and previously reported, in our patients: p.H113D, p.P172L, p.Y243del and p.Y369Q. Eleven patients presented seven known mutations: p.R127Q, p.I166I, p.A198T, p.R263G, p.R302C, p.R378C and c.1142_1145dup. The latter three were found in more than one unrelated patient: p.R302C was detected in a heterozygous girl and a mosaic male, p.R378C in two males and finally, c.1142_1145dup in three females; only one in 20 mothers was found to be a carrier (p.R263G). Apart from those 20 patients, the only alteration detected in one girl with clear PDHc and PDH-E1 deficiency was the silent change c.396A> C (p.R132R), and other eight PDHc deficient patients carry combinations of known infrequent polymorphisms that are overrepresented among our 20 unsolved patients. The importance of these changes on PDH activity is unclear. Investigations in the other PDHc genes are in course in order to elucidate the genetic defect in the unresolved patients.

Studies of human pyruvate dehydrogenase (PDH) deficiency have shown that defects in the E1 component are not common, with only a small number of defects associated specifically with the E3, E2, and component X subunits. We report here clinical, enzymatic, and immune studies of the PDH complex (PDHc) in a girl presenting with a primary defect in the component X. The patient, born from nonconsanguineous parents, presented with severe neonatal lactic acidosis, minor facial dysmorphia, and complete corpus callosum agenesis. The metabolic profile revealed marked hyperlactatemia and hyperpyruvic acidemia, with a normal lactate/pyruvate ratio and no detectable ketosis or hyperammonemia. The activity of total PDHc in cultured skin fibroblasts and in fresh mononuclear cells was markedly decreased by about 80% as compared with the controls and with the parents.

Dominant mutations in TUBB2B have been reported in patients with polymicrogyria. We further explore the phenotype associated with mutations in TUBB2B. Twenty patients with polymicrogyria (five unilateral) were tested for mutations in TUBB2B by Sanger sequencing. We identified two novel de novo mutations, c.743CT (p.Ala248Val) and c.1139GT (p.Arg380Leu) in exon 4 of TUBB2B in three unrelated families. Brain magnetic resonance images showed polymicrogyria involving predominantly the perisylvian regions. In addition, there was a dysmorphic appearance of the basal ganglia, thin corpus callosum, enlargement of the ventricles, thinning of the white matter and hypoplasia of pons and cerebellar vermis. This combination of associated features was absent in all 17 patients with polymicrogyria in whom no mutation was identified. This report underlines that the association of polymicrogyria with thin or absent corpus callosum, dysmorphic basal ganglia, brainstem and vermis hypoplasia is highly likely to result from mutations in TUBB2B and provides further insight in how mutations in TUBB2B affect protein function.

Propofol is an anesthetic agent widely used for induction and maintenance of anesthesia, and sedation in children. Although generally considered as reliable and safe, administration of propofol can occasionally induce a potentially fatal complication known as propofol infusion syndrome (PRIS). Mitochondrial dysfunction has been implicated in the pathogenesis of PRIS. We report on an adult patient with Leber hereditary optic neuropathy (LHON) who developed PRIS. He was a carrier of the m.3460GA mutation, one of the major three pathogenic point mutations associated with LHON. The propositus was blind and underwent propofol sedation after severe head injury. Five days after start of propofol infusion, the patient died. The activity of complex I of the oxidative phosphorylation (OXPHOS) system was severely deficient in skeletal muscle. Our observation indicates that fulminate PRIS can occur in an adult patient with an inborn OXPHOS defect and corroborates the hypothesis that PRIS is caused by inhibition of the OXPHOS system.

Infertility is a problem affecting many couples with a child wish. In about half of these couples a male factor is (co-) responsible for the fertility concern. For part of these patients a genetic factor will be the underlying cause of the problems. This paper gives an overview of the studies performed in the Department of Embryology and Genetics of the Vrije Universiteit Brussel and the Centre for Medical Genetics of UZ Brussel in order to gain more insight into the genetic causes of male infertility. The studies, focusing on men with fertility problems, can be subdivided into three groups: studies on deletions on the long arm of the Y chromosome, studies on X-linked genes and studies on autosomal genes. It is obvious that Yq microdeletions should be considered as a cause of male infertility. Only for patients with a complete AZFc deletion, a small number of spermatozoa can be retrieved. However, even for these patients assisted reproductive technologies are necessary. Complete AZF deletions are found in 4.6% of the patients visiting the centres for Reproductive Medicine and Medical Genetics of the UZ Brussel and for whom no other cause of the fertility problems have been detected. Taken into consideration this low prevalence of Yq microdeletions, it is obvious that also other factors, including genetic factors, must be causing fertility problems. Potentially, gr/gr deletions (partial deletions of the AZFc region) might influence the fertility status of the patients. It remains, however, unclear which of the genes located in the deleted regions are important for the progression of spermatogenesis, in case of partial or complete AZF deletions. In our studies we have also investigated mutations in genes located on the X chromosome. In analogy to the Y chromosome, the X chromosome is interesting in view of studying male infertility since men only have a single copy of the sex chromosomes. As a consequence, mutations in genes crucial for spermatogenesis will have an immediate impact on the sperm production. The genes NXF2, USP26 and TAF7L were investigated for the presence of mutations. All observed single nucleotide changes were also present in control samples, questioning their relationship with male infertility. We also studied five autosomal genes: SYCP3, MSH4, DNMT3L, STRA8 and ETV5. Only for the genes STRA8 and ETV5, changes were detected that were absent in a control population existing of men with normozoospermia. Functional analysis of the changes in ETV5 and the localization of the change observed in STRA8 showed that also these alterations were probably not the cause of the fertility problems in these men. It can be concluded that mutations are rarely detected in men with fertility problems. This low frequency of mutations has also been confirmed in several published studies. Therefore, further research is necessary to determine the impact of genetic causes on male infertility.

Although healthy babies have been born after preimplantation diagnosis for sex determination, this technique is still in an experimental phase. To date, removal by micromanipulation of one or two blastomeres from an eight-cell embryo seems an acceptable procedure. Since a reasonable number of biopsied embryos will implant and develop in utero, the methodology for the analysis of the blastomeres at the chromosomal, gene product or DNA level, needs to be improved before further clinical application. In the meanwhile, more information about early embryo development will become available.

β-glucuronidase is considered a sensitive biomarker for acute organophosphorus poisoning. In this well-documented study, multiple plasma samples over time were collected. A decrease in plasma concentration of β-glucuronidase was surprisingly observed, even within normal range. These findings do not support the hypothesis that β-glucuronidase is a useful biomarker for acute organophosphorus poisoning in humans.

Defects in the pyruvate dehydrogenase (PDH) complex are an important cause of primary lactic acidosis, a frequent manifestation of metabolic disease in children. Clinical symptoms can vary considerably in patients with PDH complex deficiencies, and almost equal numbers of affected males and females have been identified, suggesting an autosomal recessive mode of inheritance of the disease. However, the great majority of PDH complex deficiencies result from mutations in the X-linked pyruvate dehydrogenase (E1) alpha subunit gene (PDHA1). The major factors that contribute to the clinical variation in E1alpha deficiency and its resemblance to a recessive disease are developmental lethality in some males with severe mutations and the pattern of X-inactivation in females. To date, 37 different missense/nonsense and 39 different insertion/deletion mutations have been identified in the E1alpha subunit gene of 130 patients (61 females and 69 males) from 123 unrelated families. Insertion/deletion mutations occur preferentially in exons 10 and 11, while missense/nonsense mutations are found in all exons. In males, the majority of missense/nonsense mutations are found in exons 3, 7, 8 and 11, and three recurrent mutations at codons R72, R263 and R378 account for half of these patients with missense/nonsense mutations (25 of 50). A significantly lower number of females is found with missense/nonsense mutations (25). However, 36 females out of 55 affected patients have insertion/deletion mutations. The total number of female and male patients is thus almost the same, although a difference in the distribution of the type of mutations is evident between both sexes. In many families, the parents of the affected patients were studied for the presence of the PDHA1 mutation. The mutation was never present in the somatic cells of the father; in 63 mothers studied, 16 were carriers (25%). In four families, the origin of the new mutation was determined to be twice paternal and twice maternal.

The molecular basis of hereditary antithrombin (AT) deficiency has been investigated in ten Belgian and three Dutch unrelated kindreds. Eleven of these families had a quantitative or type I AT deficiency, with a history of major venous thromboembolic events in different affected members. In the other two families a qualitative or type II AT deficiency was occasionally diagnosed. DNA studies of the AT gene were performed, using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis, followed by direct sequencing of the seven exons and intron-exon junction regions. Six novel point mutations were identified: four missense, one nonsense mutation and a single nucleotide deletion near the reactive site, causing a frameshift with premature translation termination. In two kindreds the underlying genetic defect was caused by a whole gene deletion, known as a rare cause of AT deficiency. In these cases, Southern blot and polymorphism analysis of different parts of the AT gene proved useful for diagnosis. In another kindred a partial gene deletion spanning 698 basepairs could precisely be determined to a part of intron 3B and exon 4. In two type I and in both type II AT deficient families a previously reported mutation was identified. In all cases, the affected individuals were heterozygous for the genetic defect.

Absence, dysfunction or low levels of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein result in a broad range of clinical manifestations with CF with pancreatic insufficiency at the severe end of the phenotypic spectrum and, at the other end relatively mild clinical conditions, including several forms of male infertility. The condition of congenital bilateral absence of the vas deferens (CBAVD) is in 75-80% of the patients associated with defects in the CFTR gene. In the remaining patients, CBAVD is also associated with urinary tract malformations, and this form of CBAVD is not related to CF. Congenital unilateral absence of the vas deferens also seems to be associated with CF except when associated with renal abnormalities at the ipsilateral side of the absent vas. A possible role of the CFTR protein in the aetiology of infertility due to defects in sperm production and maturation has also been suggested recently. In contrast, Young's syndrome is probably not related to CF. The relation between some conditions of male infertility and CF implies appropriate clinical examination of the patients, CFTR mutation analysis and genetic counselling. Because infertility can now in many cases be treated by artificial reproductive technology couples have an increased risk of having children with CF or infertility if the female partner is also a carrier of a CFTR mutation. Couples should be well informed about these risks and risk prevention including pre-implantation diagnosis. Follow-up studies of children born to these couples are mandatory, whether male infertility is linked to CF or not.

Most of the mutations causing deficiency of the pyruvate dehydrogenase (PDH) complex are in the X-linked E1 alpha gene. We have developed a rapid screening method for the detection of mutations in this gene using reverse transcription of total RNA, polymerase chain reaction amplification of the whole coding region of the gene and single-strand conformation polymorphism (SSCP) analysis. With this method, we studied eight patients with a PDH complex deficiency, using cultured fibroblasts. In all patients, aberrant SSCP patterns were found and, after sequencing of the corresponding fragments, we were able to identify six new mutations and two mutations already described previously. The mutations are point mutations leading to amino acid substitutions (5) and direct repeat insertions (3). The presence of the mutations was confirmed in genomic fibroblast DNA. The 4 female patients were shown to carry both a normal and a mutated E1 alpha gene.

Men with congenital bilateral absence of the vas deferens (CBAVD) have been regarded as presenting a mild form of cystic fibrosis (CF). In this article, we report a case of male-factor infertility, in which both partners are carriers of the delta F508 mutation and the male partner has CBAVD. Microsurgical epididymal sperm aspiration (MESA) was performed to obtain spermatozoa; intracytoplasmic sperm injection (ICSI) was carried out on the oocytes since the motility of the spermatozoa was severely impaired; and embryo biopsy and a polymerase chain reaction (PCR) were carried out for preimplantation diagnosis of the CF delta F508 mutation. Single-blastomere analysis was performed and indicated that two embryos were affected (homozygous delta F508) and three embryos were carriers. After transfer of the latter three embryos, a singleton pregnancy was established. At amniocentesis, the delta F508 carrier status of the fetus with a 46, XY karyotype was confirmed. A healthy boy was born and the presence of vasa deferentia, bilaterally, was confirmed. The CF sweat test was also normal. Successful fertilization can be obtained by combination of MESA and ICSI in patients with CBAVD. Preimplantation diagnosis of CF is indicated. Pregnancy and birth of normal children can ensue in such patients.

Pyruvate dehydrogenase (PDH)-E1 alpha deficiency has recently been studied at the molecular-genetic level. The gene is situated on the X chromosome. We report on an unusual mutation in a familial E1 alpha deficiency. In fibroblasts, PDH deficiency was diagnosed in a young infant presenting with Leigh's encephalomyelopathy and in a maternal nephew with episodes of "malaises." In the two affected children as well as their mothers we found a silent mutation in exon 6 of the PDH-E1 alpha and an aberrant splicing of exon 6 in some of the cDNA clones. This case emphasizes the need for both genomic and cDNA analysis in cases where a PDH-E1 alpha deficiency is strongly suspected.

Inherited type 1 antithrombin (AT) III deficiency is characterized by a decrease of immunoreactive and functional protein levels to about 50%. The disorder is associated with a significantly increased risk of thromboembolism. We have investigated the molecular basis of type 1 AT deficiency in a Belgian family. The diagnosis of the disease was primarily made in a newborn girl with unusually severe thrombotic complications. Using the polymerase chain reaction and single-strand conformation polymorphism analysis, followed by direct sequencing of AT gene fragments, we identified a novel point mutation in exon 6. We detected a G to C substitution in the first position of codon 424 leading to a glycine to arginine substitution. The modification at this highly conserved position in the serine protease inhibitor gene family probably leads to an unstable mutant-gene product. The mutation creates a unique restriction site for the enzyme Hha I in exon 6. This change permitted a rapid and accurate screening of the kindred with identification of the molecular defect in five other family members.

We report the molecular characterization of a case of a functional PDH-E1 (E1 subunit of pyruvate dehydrogenase) deficiency, a cause of severe congenital lactic acidosis. Residual PDH-E1 activity was reduced to 10% of normal values, although the subunit appeared to be quantitatively and qualitatively normal at the protein level as determined by Western blotting. The sequence of PDH-E1 alpha mRNA and the corresponding genomic DNA revealed an in-frame 21-bp insertion between codons 305 and 306 of the normal E1 alpha cDNA. The mutational insert commences with a novel GAT codon and is a nearly perfect tandem duplication of the wild type DNA sequence. A serine phosphorylation site regulating the activity of the PDH complex is altered by this insertion, which in all likelihood is responsible for the functional enzymatic deficiency leading to lactic acidosis.

With the use of a linear model, the relation between urinary sodium and blood pressure has been reported to be positive, non-significant, or negative. The hypothesis that this relationship is more complex than linear was investigated in two different study populations, which were independently recruited and examined by different observers. In 1,071 men randomly selected from the general population and in an unrelated sample of 1,209 military men, systolic and diastolic blood pressure were correlated with urinary sodium following a model, which included both the linear and quadratic terms of urinary sodium. In both groups of men, these second order models, adjusted for age and body mass index, provided a better fit (P less than 0.05) than the relationships with only the linear term of urinary sodium. The quadratic models explained from 0.35 to 1.10% of the blood pressure variance. Third order models, which in addition included the cubic term of urinary sodium, did not further improve the correlations between systolic and diastolic blood pressure and urinary sodium in men. In 1,010 women drawn from the general population and in 499 military women, neither the first nor the second order correlations between systolic and diastolic blood pressure and urinary sodium were statistically significant. In conclusion, the present results, reproducible in two different study populations, suggest that a second order model is more appropriate than a simple linear correlation to describe the weak relationship between blood pressure and urinary sodium in men. However, recommendations for the prevention of hypertension must not be changed, until the present findings are confirmed by intervention studies.

The seasonal variation of 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol was analyzed in 240 elderly subjects (mean age: 78 yr) in Belgium. Serum 25-hydroxycholecalciferol was lowest from February until May (mean levels less than 25 nmol/L). Summer peak levels were, however, not higher than nadir levels in younger control subjects. A seasonal variation in total and free 1,25-dihydroxycholecalciferol concentrations was also observed in the geriatric population with a nadir in February and March (50 +/- 24 pmol/L). The peak values in summer (110 +/- 33 pmol/L) were not different from those of the younger controls. Serum calcium and phosphate were decreased whereas alkaline phosphatase and parathyroid hormone were increased throughout the year in the geriatric patients. Oral 25-hydroxycholecalciferol treatment rapidly normalized serum 1,25-dihydroxycholecalciferol concentrations in vitamin D-deficient subjects. Deficiency of both the vitamin D substrate and hormone is frequent in the elderly population in Belgium.

Calcium and vitamin D metabolism were studied in streptozotocin-treated rats up to 10 days after the induction of diabetes. Proteinuria, hypercalciuria, and hyperphosphaturia appeared as early as 3 days after diabetes induction and were reversed by insulin. The serum proteins and fasting calcium concentrations were decreased in untreated diabetic rats. The concentration of serum vitamin D binding protein (DBP) was higher in male than in female control rats (mean +/- SD; 555 +/- 73 vs. 348 +/- 28 mg/liter, P less than 0.001). When sequentially measured in male untreated diabetic rats, DBP concentration steadily decreased. Compared with control values, DBP was reduced 19%, 28%, and 32% on days 3, 6, and 10, respectively, after induction of diabetes in male rats. In female animals, DBP was reduced 22% on day 10 of diabetes. DBP concentration was corrected by insulin treatment of diabetic rats and remained normal in streptozotocin-treated animals that did not develop diabetes. The serum concentration of 25-hydroxyvitamin D3 was similar in both sexes and was not affected by diabetes. Like DBP, the concentration of total 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] was higher in male than in female control rats (120 +/- 24 vs. 96 +/- 17 ng/liter, P less than 0.001), but 10 days after induction of diabetes this concentration decreased by 37% and 29% in male and female rats, respectively. The free 1,25-(OH)2D3 concentration, estimated from the molar 1,25-(OH)2D3/DBP ratio, was similar in both sexes and was not decreased by diabetes. We conclude that experimental diabetes in the rat induces a decrease in DBP concentration and a concomitant decrease in total but not in free 1,25-(OH)2D3 concentrations. This may indicate that diabetes decreases circulating 1,25-(OH)2D3 concentrations through alterations in DBP levels.

An elderly Belgian population group anno 1986 consisting of 53 men and 110 women above the age of 75 years with a mean age of 80 and 81 years, respectively, is characterized by relative obesity and low diastolic blood pressure, both in men and women. The SBP/DBP ratio is 1.91 in men and 1.88 in women. HDL-cholesterol levels are relatively high in men. Women still have slightly higher HDL-cholesterol levels than men, the difference between women and men being 3.4 mg/dl. In both sexes HDL-cholesterol correlates negatively with body weight. The 24-hour urinary sodium/potassium ratio is 2.9 in men and 2.5 in women. Factors significantly related to diastolic blood pressure in a multiple regression analysis included being on a low-salt diet, the level of 24-hour urinary potassium excretion and of 24-hour urinary creatinine excretion in men, and body weight, heart rate and the level of 24-hour urinary calcium excretion in women. It may be concluded that significant differences exist between the distribution of cardiovascular risk factors in older compared to middle-aged subjects.

An expert system was developed in order to obtain uniform and fast phenotyping and reporting of dyslipoproteinemia. PROLOG is used as knowledge representation formalism. The program is in daily use on an IBM PC AT, in the Laboratory of Clinical chemistry of the University Hospitals in Leuven. Evaluation has proved the system to be reliable and useful for the interpretation of lipoprotein disorders. Indeed accuracy figures of 98.4% and 95.2% were obtained in the learning (N = 315) and test set (N = 126) respectively.

Vitamin D and bone mineral metabolism during pregnancy were studied in 17 diabetic and 13 control BB rats. On day 21 of pregnancy, reduced mean levels of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3; 56.9 vs. 97.9 pg/ml; P less than 0.0001] and vitamin D-binding protein (304 vs. 482 micrograms/ml; P less than 0.0001) were found in the diabetic rats, while the free 1,25-(OH)2D3 concentration was not different from the control level. Total plasma calcium and total plasma protein concentrations were also significantly decreased in the diabetic group, but the calculated diffusible calcium was not significantly lower. Calcium and phosphorus urinary excretion were increased in the diabetic rats. There was no difference in bone mineral content. The fetuses of the diabetic BB rat had a lower body weight and were hypoinsulinemic. Both 1,25-(OH)2D3 (41.3 vs. 54.7 pg/ml; P less than 0.01) and vitamin D-binding protein (80 vs. 123 micrograms/ml; P less than 0.001) were decreased in the fetuses of diabetic rats, but the free 1,25-(OH)2D3 concentration was slightly but significantly (6.96 vs. 5.54; P less than 0.05) increased. We observed that the fetuses of diabetic rats had fewer ossification centers, counted with the Alizarin Red S staining method. The fetal ash weight was lower in the diabetic group (16.7 vs. 26.9 mg; P less than 0.0001). In addition, the relative calcium and phosphorus, but not magnesium, content of ash was lower in the fetuses of diabetic rats. This reduced mineral content in fetuses of diabetic mothers could be implicated in the pathogenesis of early neonatal hypocalcemia in infants of diabetic mothers.

The response of plasma aldosterone, cortisol and adrenocorticotropin (ACTH) to the dopamine antagonists metoclopramide and domperidone, administered intravenously in a dose of 1 mg/kg, was investigated in healthy volunteers. Within 15 min after metoclopramide administration, plasma aldosterone (+ 99%), cortisol (+ 75%) and ACTH (+ 55%) increased (p less than 0.001), whereas the plasma levels of these hormones were not altered after domperidone. The differential responses of plasma aldosterone and cortisol to high doses of metoclopramide and domperidone are therefore, at least partially, mediated via the enhanced adrenal stimulation by ACTH after metoclopramide.

The erythrocyte concentrations and the transmembrane fluxes of sodium and potassium were investigated in normal men and also in twenty normal women during the two stages of the menstrual cycle. Half of them were taking the contraceptive pill and the other half were not. In women with a normal menstrual cycle, the erythrocyte sodium concentration (Naic) and the ouabain-insensitive total potassium efflux were lower in the luteal than in the follicular phase. Intracellular potassium concentration (Kic), ouabain-sensitive 86rubidium-uptake and the furosemide-sensitive Na+ and K+ efflux did not differ significantly between the two periods of the cycle. No cycle-related variation in Naic or Kic was observed in women using the contraceptive pill. In these women, however, the ouabain-sensitive 86rubidium-uptake was increased in the second part of the menstrual cycle. Compared to men, the intra-erythrocyte sodium concentration was lower in women during the second stage of the menstrual cycle. These two groups were similar for Na+, K+-ATPase pump activity estimated from the ouabain-sensitive 86rubidium-uptake and for the furosemide-sensitive sodium and potassium efflux. Women in the first stage of the menstrual cycle had intra-erythrocyte sodium concentration similar to men, but their furosemide-sensitive sodium efflux was lower. No significant difference was observed in the intraerythrocyte potassium concentration and transmembrane fluxes of potassium in men and women in either stage of the menstrual cycle. We therefore conclude from this study that one should take into account sex-related variability when studying cationic fluxes and concentrations in red blood cells of men and women.The erythrocyte concentrations and the transmembrane fluxes of sodium and potassium were investigated in normal men and also in 20 normal women during the 2 stages of the menstrual cycle. 1/2 were taking oral contraceptives (OCS) and the other 1/2 were not. In women with a normal menstrual cycle, the erythrocyte sodium concentration (Naic) and the ouabain-insensitive total potassium efflux were lower in the luteal than in the follicular phase. Intracellular potassium concentration (Kic), ouabain-sensitive 86 rubidium-uptake, and the furosemide-sensitive Na+ and K+ afflux did not differ significantly between the 2 periods of the cycle. No cycle-related variation in Naic or Kic was observed in women using OCs. In these women, however, the ouabain-sensitive 86 rubidium-uptake was increased in the 2nd part of the menstrual cycle. When compared to men, the intra-erythrocyte sodium concentration was lower in women during the 2nd stage of the menstrual cycle. These 2 groups were similar for Na+, K+-ATPase pump activity estimated from the ouabain-sensitive 86 rubidium-uptake, and for the furosemide-sensitive sodium and potassium efflux. Women in the 1st stage of the menstrual cycle had intra-erythrocyte sodium concentration similar to men but their furosemide-sensitive sodium efflux was lower. No significant difference was obsesrved in the intra-erythrocyte potassium concentration and transmembrane fluxes of potassium in men and women in either stage of the menstrual cycle. The authors thus conclude that one should take into account sex-related variability when studying cationic fluxes and concentrations in red blood cells of men and women.

The antihypertensive effect and safety of doxazosin once daily as well as the effect on serum lipids was compared with that of atenolol once daily in 40 patients with mild to moderate hypertension. During the first 4 weeks, all patients received placebo therapy. During the subsequent 46 weeks, patients were randomized to doxazosin or atenolol treatment. Treatment was initiated with 1 mg doxazosin or 50 mg atenolol once daily. The dose could be doubled biweekly for 10 weeks until a final dose of 16 mg doxazosin or 100 mg atenolol was reached. The patients then entered the maintenance phase for 36 weeks. The average final dose of doxazosin was 9.2 +/- 1.3 (SEM) mg and that of atenolol was 76.5 +/- 6.2 mg. During the 46 weeks of active treatment, the recumbent diastolic blood pressure (DBP) tended to be lower (p less than 0.05) in patients receiving atenolol at 10, 12, and 22 weeks of treatment. Recumbent systolic BP (SBP) and standing SBP and DBP were not different, however, between patients receiving doxazosin and those receiving atenolol. Recumbent and standing heart rate (HR) were lower (p less than 0.01) during atenolol. The decrease in serum total triglycerides, total cholesterol, and low-density lipoprotein (LDL)-cholesterol after 46 weeks of doxazosin was different (p less than 0.05) from the changes observed during atenolol therapy. Our data indicate that the antihypertensive action of doxazosin is accompanied by favorable effects on serum lipids.

The linkage relationships between the cystic fibrosis (CF) locus and four marker loci (MET-H, MET-D, D7S8 and D7S16), allelic associations between these loci and the extent of informativity at these marker loci were investigated in a sample of 206 families with at least one child affected by CF. The data were contributed by 11 laboratories from Europe and Israel. The maximum lod scores and recombination frequency estimates ( $$\hat \theta $$ ) (and confidence limits of θ) were: 18.3 at $$\hat \theta $$ =0.007(0.001−0.038) for CF vs. MET, 11.0 at $$\hat \theta $$ (0.001–0.068) for CF vs. D7S8, and 5.7 at $$\hat \theta $$ =0.0(0.0−0.064) for CF vs. D7S16. A gene order of CF-MET-D7S8 was best supported by the data, but its preference to the order D7S8-CF-MET is mainly based on one single family. There are significant allelic associations between CF, MET, D7S8 and D7S16; these allelic associations affect the risk of random individuals to be carriers of CF.

SummaryChronic intoxication with inorganic bromide is described in a patient whose symptoms, for years 1 ascribed to neurocirculatory asthenia, disappeared f after stopping bromide intake. The finding of hyperchloremia and of a decreased serum anion gap were the hints towards the diagnosis.

The normal range of activities of 6 lysosomal enzymes was determined in extracts of chorionic villi samples obtained by a rigid forceps in the first trimester of pregnancy. These activities were compared to those in villi obtained after abortion and in cultured amniotic fluid cells and fibroblasts. For five of the six enzymes tested, the data suggest that first trimester prenatal diagnosis should be possible and reliable. For the sixth enzyme, alpha-L-fucosidase, where on occasion very low activities were found, the results obtained on fresh chorionic villi have to be interpreted with extreme caution. Considerable lysosomal enzyme activities were also found in maternal decidua. Therefore, extreme care must be taken in the preparation of chorionic villi for prenatal diagnosis of lysosomal disorders since even small amounts of maternal tissue could lead to misdiagnosis. This study has allowed us to monitor 2 pregnancies at risk for lysosomal storage disease. Differences in the isoenzyme pattern of alpha-L-fucosidase were found in chorionic villi and maternal decidua. Although further studies are required, this observation could lead to the development of immuno-biochemical methods to evaluate the purity of chorionic villi used for prenatal diagnosis.

Erythrocyte concentrations and fluxes of sodium and potassium were investigated in normal white male subjects during dietary sodium restriction and repletion, each period lasting for 16 weeks. Intraerythrocyte sodium concentration decreased and red cell ouabain-sensitive 86Rubidium-uptake increased during dietary sodium restriction while no significant changes were observed in the total, furosemide-resistant and furosemide-sensitive sodium-efflux and the sodium, lithium-countertransport. The decrease in intraerythrocyte sodium concentration could have resulted from the observed increase in sodium, potassium-ATPase pump activity. The latter increase could have been secondary to the early decrease in a digitalis-like plasma inhibitor and the later increase could have been facilitated by the late rise in the intracellular adenosine triphosphate concentration, which is the energy supplier for this pump. During the subsequent first month of sodium repletion intraerythrocyte sodium concentration remained low. Red cell ouabain-sensitive 86Rubidium-uptake and adenosine triphosphate concentration remained elevated and returned to baseline only after 16 weeks. This long-term effect suggests either the involvement of a mechanism which can only be slowly reversible or a mechanism which is irreversible so that normalization takes place only when new red cells are released into the circulation.

The effects of anticonvulsant therapy on serum parameters of calcium metabolism has been evaluated in 80 institutionalised epileptics and compared to a sex and age matched control group from the same institutions. Patients on long-term anticonvulsant therapy differed significantly from controls in respect of serum parameters of calcium metabolism.The mean alkaline phosphatase level was significantly raised in epileptics of both sexes. Male epileptics had in addition a significantly lower mean serum calcium and phosphorus level, in contrast to the female epileptic group where the corresponding mean values were normal. Female patients, however, had a lower mean serum bicarbonate level which suggests peripheral effects of secondary hyperparathyroidism, which in turn may explain the normal mean serum calcium level. Within the female epileptic group only the postmenopausal women had a raised serum alkaline phosphatase level.The results indicate a different effect of anticonvulsant drugs on calcium meta...

The effect of short-term calcium antagonism with felodipine on blood pressure and on some biochemical plasma variables such as catecholamines, renin and aldosterone was studied in 10 normal volunteers at rest and during incremental bicycle exercise. At rest, diastolic blood pressure was slightly decreased during felodipine, whereas systolic pressure and heart rate were not significantly changed. The plasma noradrenaline concentration and plasma renin activity were increased during felodipine treatment; the plasma adrenaline and aldosterone concentrations on the contrary, were not significantly changed. The rises in plasma renin activity, plasma aldosterone and plasma adrenaline and noradrenaline concentrations produced by exercise were not significantly affected by felodipine. The plasma calcium concentration was significantly higher during felodipine treatment than during placebo and this was accompanied by an increased urinary calcium excretion. It is concluded that the rise in plasma renin activity during calcium antagonism with felodipine is not accompanied by a significant increase in plasma aldosterone. Furthermore, the present data suggest that, at least during exercise, calcium antagonism does not interfere with the mechanisms underlying the exercise-induced activation of renin and aldosterone release.

A pancreatic isoamylase method (Pancreatic Alpha-Amylase EPS, Boehringer) that uses monoclonal antibodies showed almost complete immunoinhibition of salivary (S) amylase activity with only a minor decrease of pancreatic (P) amylase activity. The method displayed good sensitivity and linearity. The correlations of P-amylase activities determined by this technique with a wheat-germ inhibition method and with agarose electrophoresis followed by densitometric scanning were excellent. However, both the wheat-germ and monoclonal inhibition methods failed to detect macroamylasaemia. To recognise macroamylases we used the PEG precipitation method and confirmed the results with agarose electrophoresis. Of 161 serum samples with elevated amylase activities, only four out of five with macroamylasaemia were detected by the PEG precipitation method. No false positives were demonstrated. After PEG precipitation of 28 samples, P-amylase determinations were performed on the supernatants. Again, four out of five with macroamylasaemia were recognised. We consider P-amylase measurement and, when macroamylasaemia is suspected, the combined use of the PEG precipitation method and P-amylase or total amylase determination to be the most practical way to differentiate between elevated serum amylase levels.

Serum parameters of calcium metabolism were measured in 32 consecutive patients with biopsy-proven cirrhosis due to either hepatitis (n = 13), alcohol abuse (n = 11), Wilson's disease (n = 3), or primary or secondary biliary cirrhosis (n = 5). All measurements were normal in the small group of patients with Wilson's disease. The serum concentrations of albumin, vitamin D-binding protein, total calcium, phosphorus, and 1,25-dihydroxyvitamin D3 (1,25-(OH2)D3) were decreased in the other patients with cirrhosis, but their mean serum concentrations of ionized calcium, 25-hydroxyvitamin D3 (25-OHD3) and free 1,25-(OH2)D3 index were normal. A slight but significant increase in the serum PTH measured using a carboxyl-terminal antiserum was found. A significant correlation was found between the serum concentration of either albumin or vitamin D-binding protein and the serum concentrations of total calcium, 25-OHD3, 1,25-(OH2)D3, and PTH but not with ionized calcium or free 1,25-(OH2)D3 index. The observed abnormalities of calcium metabolism in unselected patients with cirrhosis were mainly due to decreased protein synthesis. Only the patients with severe cirrhosis had decreased concentrations of 25-OHD3 but they were nevertheless able to maintain a normal ionized serum calcium and free 1,25-(OH2)D3 level, possibly by means of compensatory hyperparathyroidism.

Serum lipids and apoproteins have been measured in 307 men and 235 women living around Benin City in Nigeria. Total serum cholesterol values are low compared both to White Western populations and to American Blacks. HDL-cholesterol levels, however, are comparable to values in Western and Oriental men, but lower than in Western women. A highly significant correlation exists between total cholesterol and apo B and between HDL-cholesterol and apo A-I in men and women. The low serum lipid values are related to a low dietary fat intake, almost exclusively from palm oil, in the Nigerian population.

The relationships between blood pressure and 24-h urinary sodium, potassium, calcium and magnesium were investigated in adult men and women constituting a random sample of urban Bantu of Zaire. Blood pressure and the 24-h urinary sodium, potassium, calcium and magnesium averaged 124 +/- 20/72 +/- 14 mmHg, 87 +/- 51 mmol, 33 +/- 19 mmol, 828 +/- 91 mumol and 1.9 +/- 1.6 mmol, respectively. After adjusting for sex, age, body weight and pulse rate, systolic pressure was significantly and positively correlated with urinary sodium in all subjects and in women taken separately; it was also negatively correlated with urinary potassium, while diastolic pressure was weakly associated with urinary calcium. When instead of the 24-h urinary sodium and potassium the sodium: potassium ratio was considered as an independent variable in multiple regression analysis, it was correlated with both systolic and diastolic pressure. Our results indicate that age, body weight, pulse rate, sex and the sodium: potassium ratio contribute to the prediction of systolic and diastolic blood pressure, while urinary calcium was only associated with diastolic pressure.